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Sample records for yeast strain candida

  1. Performance of CHROMAGAR candida and BIGGY agar for identification of yeast species

    OpenAIRE

    Marol Serhat; Yücesoy Mine

    2003-01-01

    Abstract Background The importance of identifying the pathogenic fungi rapidly has encouraged the development of differential media for the presumptive identification of yeasts. In this study two differential media, CHROMagar Candida and bismuth sulphite glucose glycine yeast agar, were evaluated for the presumptive identification of yeast species. Methods A total number of 270 yeast strains including 169 Candida albicans, 33 C. tropicalis, 24 C. glabrata, 18 C. parapsilosis, 12 C. krusei, 5 ...

  2. Performance of CHROMAGAR candida and BIGGY agar for identification of yeast species

    Directory of Open Access Journals (Sweden)

    Marol Serhat

    2003-10-01

    Full Text Available Abstract Background The importance of identifying the pathogenic fungi rapidly has encouraged the development of differential media for the presumptive identification of yeasts. In this study two differential media, CHROMagar Candida and bismuth sulphite glucose glycine yeast agar, were evaluated for the presumptive identification of yeast species. Methods A total number of 270 yeast strains including 169 Candida albicans, 33 C. tropicalis, 24 C. glabrata, 18 C. parapsilosis, 12 C. krusei, 5 Trichosporon spp., 4 C. kefyr, 2 C. lusitaniae, 1 Saccharomyces cerevisiae and 1 Geotrichum candidum were included. The strains were first identified by germ tube test, morphological characteristics on cornmeal tween 80 agar and Vitek 32 and API 20 C AUX systems. In parallel, they were also streaked onto CHROMagar Candida and bismuth sulphite glucose glycine yeast agar plates. The results were read according to the color, morphology of the colonies and the existance of halo around them after 48 hours of incubation at 37°C. Results The sensitivity and specificity values for C. albicans strains were found to be 99.4, 100% for CHROMagar Candida and 87.0, 75.2% for BiGGY agar, respectively. The sensitivity of CHROMagar Candida to identify C. tropicalis, C. glabrata and C. krusei ranged between 90.9 and 100% while the specificity was 100%. The sensitivity rates for BiGGY agar were 66.6 and 100% while the specificity values were found to be 95.4 and 100% for C. tropicalis and C. krusei, respectively. Conclusions It can be concluded that the use of CHROMagar Candida is an easy and reliable method for the presumptive identification of most commonly isolated Candida species especially C. albicans, C. tropicalis and C. krusei. The lower sensitivity and specificity of BiGGY agar to identify commonly isolated Candida species potentially limits the clinical usefulness of this agar.

  3. Performance of CHROMAGAR candida and BIGGY agar for identification of yeast species.

    Science.gov (United States)

    Yücesoy, Mine; Marol, Serhat

    2003-10-29

    The importance of identifying the pathogenic fungi rapidly has encouraged the development of differential media for the presumptive identification of yeasts. In this study two differential media, CHROMagar Candida and bismuth sulphite glucose glycine yeast agar, were evaluated for the presumptive identification of yeast species. A total number of 270 yeast strains including 169 Candida albicans, 33 C. tropicalis, 24 C. glabrata, 18 C. parapsilosis, 12 C. krusei, 5 Trichosporon spp., 4 C. kefyr, 2 C. lusitaniae, 1 Saccharomyces cerevisiae and 1 Geotrichum candidum were included. The strains were first identified by germ tube test, morphological characteristics on cornmeal tween 80 agar and Vitek 32 and API 20 C AUX systems. In parallel, they were also streaked onto CHROMagar Candida and bismuth sulphite glucose glycine yeast agar plates. The results were read according to the color, morphology of the colonies and the existance of halo around them after 48 hours of incubation at 37 degrees C. The sensitivity and specificity values for C. albicans strains were found to be 99.4, 100% for CHROMagar Candida and 87.0, 75.2% for BiGGY agar, respectively. The sensitivity of CHROMagar Candida to identify C. tropicalis, C. glabrata and C. krusei ranged between 90.9 and 100% while the specificity was 100%. The sensitivity rates for BiGGY agar were 66.6 and 100% while the specificity values were found to be 95.4 and 100% for C. tropicalis and C. krusei, respectively. It can be concluded that the use of CHROMagar Candida is an easy and reliable method for the presumptive identification of most commonly isolated Candida species especially C. albicans, C. tropicalis and C. krusei. The lower sensitivity and specificity of BiGGY agar to identify commonly isolated Candida species potentially limits the clinical usefulness of this agar.

  4. Utilization of Candida berkhout strains in the production of yeasts and ethyl alcohol from sulfite waste liquor and molasses

    Energy Technology Data Exchange (ETDEWEB)

    Karczewska, H

    1962-01-01

    A single strain of Candida tropicalis was used to produce EtOH and fodder yeast from pasteurized, neutralized sulfite liquor containing 3.5% reducing substances and supplemented with NH/sub 3/ and P salts, or from molasses containing 150 g sucrose per l. After 48 hours sugar utilization by Candida was 87.7% and EtOH yield 56.1%; Saccharomyces cerevisiae gave 94.8 and 64.6 to 65.2%, respectively. After 72 hours sugar utilization and EtOH yield by Candida was 94.9 and 60.4% respectively.

  5. Prevalence of candida and non-candida yeasts isolated from patients with yeast fungal infections in Tehran labs

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    Hashemi SJ

    2011-04-01

    Full Text Available "n 800x600 Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} Background: Infections caused by opportunistic yeasts such as Candida species, Trichosporon, Rhodotorula and Saccharomyces have increased in immunocompromis-ed patients and their identification is crucial as intrinsic and acquired resistance of some yeast species to antifungal agents are on the rise. The aim of this study was to identify the organisms to the species level in order to suggest accurate and effective antifungal therapies."n"nMethods: In this study that carried out in Tehran, Iran in 2009, 200 patients with yeast infection were medically examined and clinical specimens were prepared for direct examination and culture on Sabouraud dextrose agar. Subsequently, the isolated yeast colonies were identified using various tests including culture on Corn Meal agar with Tween 80, CHROMagar Candida and casein agar. For the definite identification of organisms some biochemical tests were done based on carbohydrate assimilation by RapID Yeast Plus System kit, and, finally, a molecular method, PCR-RFLP, using Hpa II enzyme, was performed for the remaining unknown yeast species."n"nResults: A total of 211 yeast isolates were identified in 200 patients with yeast infections. The most frequent isolated yeasts were Candida albicans, 124 (58.77%, followed by Candida parapsilosis, 36 (17.06%, Candida tropicalis, 17 (8.06%, Candida glabrata, 13 (6.16%, Candida krusei, 8 (3.79%, Candida guilliermondii, 2 (0.96%, Trichosporon, 3 (1.14%, Rhodotorula, 1 (0.47%, Saccaromyces cerevisiae, 1 (0.47% and other

  6. Possibility for simultaneous electricity generation and bioremediation by using Candida melibiosica yeast in biofuel cell

    International Nuclear Information System (INIS)

    Hubenova, Yolina; Georgiev, Danail; Mitov, Mario

    2013-01-01

    Recently, we have proved that Candida melibiosica 2491 yeast strain possesses electrogenic properties and could be used as a biocatalyst in yeast-based biofuel cells. In this paper we demonstrate that when the yeast is cultivated under polarization conditions in a biofuel cell its phytase activity exceeds that obtained during cultivation in a conventional bioreactor. Furthermore, there is a correlation between the yeast phytase activity and the electrical characteristic of the biofuel cell during the different yeast growth phases. The obtained results reveal a possibility for application of C.melibiosica for simultaneous electricity generation and bioremediation of hardly degradable polyphosphates, especially in the regions with intensive stock-farming. Keywords: Biofuel cells, yeast, Candida melibiosica, electricity generation, bioremediation

  7. Selection of lactose-fermenting yeast for ethanol production from whey. [Candida pseudotropicalis ATCC 8619

    Energy Technology Data Exchange (ETDEWEB)

    Izaguirre, M E; Castillo, F J

    1982-01-01

    Candida pseudotropicalis ATCC 8619 was selected from among 9 strains of lactose-fermenting yeasts on the basis of its ability to ferment concentrated whey. In 28% deproteinized whey solutions it produced an average of 12.4% EtOH. This yeast could be used in a process for whey treatment.

  8. Candida xinjiangensis sp. nov., a new anamorphic yeast species isolated from Scolytus scheryrewi Semenov in China.

    Science.gov (United States)

    Zhu, Xiao-Feng; Zhang, Dian-Peng; Yang, Sen; Zhang, Qing-Wen

    2017-03-01

    Three yeast strains designated as S44, XF1 and XF2, respectively, were isolated from Scolytus scheryrewi Semenov of apricot tree in Shule County, Xinjiang, China, and were demonstrated to be a new member of the genus Candida by sequence comparisons of 26S rRNA gene D1/D2 domain and internal transcribed spacer (ITS) region. BLASTn alignments on NCBI showed that the similarity of 26S rRNA gene sequences of S44 (type strain) to all sequences of other Candida yeasts was very low (≦93 %). The phylogenetic tree based on the 26S rRNA gene D1/D2 domain and ITS region sequences revealed that the strain S44 is closely related to C. blattae, C. dosseyi, C. pruni, C. asparagi, C. fructus and C. musae. However, the strain S44 is distinguished from these Candida species by the physiological characteristics. Moreover, the strain S44 formed typical pseudohyphae when grown on cornmeal agar at 25 °C for 7 days, but did not form ascospores in sporulation medium for 3-4 weeks. Therefore, the name Candida xinjiangensis is proposed for the novel species, with S44 (=KCTC T 27747) as the type strain.

  9. Formation of new chromosomes as a virulence mechanism in yeast Candida glabrata

    DEFF Research Database (Denmark)

    Poláková, S.; Blume, C.; Zárate, J. A.

    2009-01-01

    , Candida glabrata, for their genome structure and stability. This organism has recently become the second most prevalent yeast pathogen in humans. Although the gene sequences were well conserved among different strains, their chromosome structures differed drastically. The most frequent events reshaping...

  10. Candida neustonensis sp. nov., a novel ascomycetous yeast isolated from the sea surface microlayer in Taiwan.

    Science.gov (United States)

    Chang, Chin-Feng; Lee, Ching-Fu; Liu, Shiu-Mei

    2010-01-01

    A new ascomycetous yeast species, Candida neustonensis is proposed in this study based on four strains (SN92(T), SN47, SJ22, SJ25) isolated from sea surface microlayer in Taiwan. These four yeast strains were morphologically, physiologically and phylogenetically identical to each other. No sexual reproduction was observed on 5% malt extract agar, corn meal agar, V8 agar, McClary's acetate agar and potato-dextrose agar. Phylogenetic analysis of the sequences of the D1/D2 domain of the large subunit (LSU) rRNA gene places C. neustonensis as a member of the Pichia guilliermondii clade, it also reveals that the phylogenetically closest relatives of C. neustonensis are C. fukuyamaensis (4.4% divergence), C. xestobii (4.4% divergence) and P. guilliermondii (4.5% divergence). C. neustonensis also is clearly distinguished from other known species in the P. guilliermondii clade based on the results of physiology tests. From these comparison analyses, the following novel yeast species is proposed: Candida neustonensis sp. nov., with strain SN92(T) (= BCRC 23108(T) = JCM 14892(T) = CBS 11061(T)) as the type strain.

  11. Isolation and Characterization of Hydrocarbon-Degrading Yeast Strains from Petroleum Contaminated Industrial Wastewater

    Science.gov (United States)

    Gargouri, Boutheina; Mhiri, Najla; Karray, Fatma; Aloui, Fathi; Sayadi, Sami

    2015-01-01

    Two yeast strains are enriched and isolated from industrial refinery wastewater. These strains were observed for their ability to utilize several classes of petroleum hydrocarbons substrates, such as n-alkanes and aromatic hydrocarbons as a sole carbon source. Phylogenetic analysis based on the D1/D2 variable domain and the ITS-region sequences indicated that strains HC1 and HC4 were members of the genera Candida and Trichosporon, respectively. The mechanism of hydrocarbon uptaking by yeast, Candida, and Trichosporon has been studied by means of the kinetic analysis of hydrocarbons-degrading yeasts growth and substrate assimilation. Biodegradation capacity and biomass quantity were daily measured during twelve days by gravimetric analysis and gas chromatography coupled with mass spectrometry techniques. Removal of n-alkanes indicated a strong ability of hydrocarbon biodegradation by the isolated yeast strains. These two strains grew on long-chain n-alkane, diesel oil, and crude oil but failed to grow on short-chain n-alkane and aromatic hydrocarbons. Growth measurement attributes of the isolates, using n-hexadecane, diesel oil, and crude oil as substrates, showed that strain HC1 had better degradation for hydrocarbon substrates than strain HC4. In conclusion, these yeast strains can be useful for the bioremediation process and decreasing petroleum pollution in wastewater contaminated with petroleum hydrocarbons. PMID:26339653

  12. Isolation and Characterization of Hydrocarbon-Degrading Yeast Strains from Petroleum Contaminated Industrial Wastewater

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    Boutheina Gargouri

    2015-01-01

    Full Text Available Two yeast strains are enriched and isolated from industrial refinery wastewater. These strains were observed for their ability to utilize several classes of petroleum hydrocarbons substrates, such as n-alkanes and aromatic hydrocarbons as a sole carbon source. Phylogenetic analysis based on the D1/D2 variable domain and the ITS-region sequences indicated that strains HC1 and HC4 were members of the genera Candida and Trichosporon, respectively. The mechanism of hydrocarbon uptaking by yeast, Candida, and Trichosporon has been studied by means of the kinetic analysis of hydrocarbons-degrading yeasts growth and substrate assimilation. Biodegradation capacity and biomass quantity were daily measured during twelve days by gravimetric analysis and gas chromatography coupled with mass spectrometry techniques. Removal of n-alkanes indicated a strong ability of hydrocarbon biodegradation by the isolated yeast strains. These two strains grew on long-chain n-alkane, diesel oil, and crude oil but failed to grow on short-chain n-alkane and aromatic hydrocarbons. Growth measurement attributes of the isolates, using n-hexadecane, diesel oil, and crude oil as substrates, showed that strain HC1 had better degradation for hydrocarbon substrates than strain HC4. In conclusion, these yeast strains can be useful for the bioremediation process and decreasing petroleum pollution in wastewater contaminated with petroleum hydrocarbons.

  13. Adaptation of Microstix®-Candida Slide-test for Diagnosis of Bovine Mastitis Due to Anascogenic Yeasts

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    Przemysław Dudko

    2010-01-01

    Full Text Available Although a large diversity of mastitis-causing bacteria (150 species, subspecies or biovars have been documented, an adequate and simple mycological screening for yeast-related mastitis has not been developed. Since yeast incubation normally lasts longer than the majority of bacteriological ones, usually a treatment is administered before the results of microbial cultures are obtained. Therefore, a simple test has been needed for detection of yeast-related mastitis, the results of which can be read in parallel to bacteriological screening. Application of Microstix®-Candida assay was first checked for its specificity in standard Candida albicans (Oxford strain cultures (phase I and then in the other 36 strains of yeasts isolated from clinical mastitis cases during field investigations (second phase. Next, a test was implemented for identification of pathogens in 9 cohorts (1,200 cows from red-white Polish- Friesian breed in which the dynamics of mastitis were traced by bacteriological and mycological assays along year-long observations. The data obtained showed that apart from frequent infections (~50-70% proved by using pure microbial cultures, also mixed (bacterial-fungal infections (0-25% appeared as well as negative sieves (in the range of 0-45%. Mycological assays revealed a significant fraction of mixed infections during both lactation and the dry period. Strepto-staphylococcal infection was thus identified, however, its proportion strongly decreased after the introduction of antibiotics (after sensitivity to microbial agents was determined. Microbial monitoring was improved in these herds by parallel application of bacteriological and mycological (particularly Microstix®- Candida tests. Microstix®-assay appears to be useful for mycological diagnosis in field conditions of infected (mastitis herds. Its advantages include easy performance and short incubation time that is only 24 h at 37 °C (72-96 h at room temperature. This allowed

  14. Selection of yeast strains for the production of alcohol from lactoserum

    Energy Technology Data Exchange (ETDEWEB)

    Laham-Guillaume, M; Moulin, G; Galzy, P

    1979-01-01

    Five of 11 yeast strains tested fermented 85 g lactose/L to approximately 5% EtOH. Four of these strains, Candida pseudotropicalis CBS 19384 and IP 513, and Kluyveromyces fragilis CBS 397, and CBS 5795, anaerobically fermented deproteinized whey to EtOH.

  15. Differential identification of Candida species and other yeasts by analysis of [35S]methionine-labeled polypeptide profiles

    International Nuclear Information System (INIS)

    Shen, H.D.; Choo, K.B.; Tsai, W.C.; Jen, T.M.; Yeh, J.Y.; Han, S.H.

    1988-01-01

    This paper describes a scheme for differential identification of Candida species and other yeasts based on autoradiographic analysis of protein profiles of [ 35 S]methionine-labeled cellular proteins separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Using ATCC strains as references, protein profile analysis showed that different Candida and other yeast species produced distinctively different patterns. Good agreement in results obtained with this approach and with other conventional systems was observed. Being accurate and reproducible, this approach provides a basis for the development of an alternative method for the identification of yeasts isolated from clinical specimens

  16. Production of sophorolipids biosurfactants by multiple species of the Starmerella (Candida) bombicola yeast clade

    Science.gov (United States)

    Sophorolipid production was tested for 26 strains representing 19 species of the Starmerella yeast clade, including S. bombicola and Candida apicola, which were previously reported to produce sophorolipids. Five of the 19 species tested showed significant production of sophorolipids: S. bombicola, ...

  17. In Vitro Activities of Terbinafine against Cutaneous Isolates of Candida albicans and Other Pathogenic Yeasts

    Science.gov (United States)

    Ryder, Neil S.; Wagner, Sonja; Leitner, Ingrid

    1998-01-01

    Terbinafine is active in vitro against a wide range of pathogenic fungi, including dermatophytes, molds, dimorphic fungi, and some yeasts, but earlier studies indicated that the drug had little activity against Candida albicans. In contrast, clinical studies have shown topical and oral terbinafine to be active in cutaneous candidiasis and Candida nail infections. In order to define the anti-Candida activity of terbinafine, we tested the drug against 350 fresh clinical isolates and additional strains by using a broth dilution assay standardized according to the guidelines of the National Committee for Clinical Laboratory Standards (NCCLS) M27-A assay. Terbinafine was found to have an MIC of 1 μg/ml for reference C. albicans strains. For 259 clinical isolates, the MIC at which 50% of the isolates are inhibited (MIC50) of terbinafine was 1 μg/ml (fluconazole, 0.5 μg/ml), and the MIC90 was 4 μg/ml (fluconazole, 1 μg/ml). Terbinafine was highly active against Candida parapsilosis (MIC90, 0.125 μg/ml) and showed potentially interesting activity against isolates of Candida dubliniensis, Candida guilliermondii, Candida humicola, and Candida lusitaniae. It was not active against the Candida glabrata, Candida krusei, and Candida tropicalis isolates in this assay. Cryptococcus laurentii and Cryptococcus neoformans were highly susceptible to terbinafine, with MICs of 0.06 to 0.25 μg/ml. The NCCLS macrodilution assay provides reproducible in vitro data for terbinafine against Candida and other yeasts. The MICs for C. albicans and C. parapsilosis are compatible with the known clinical efficacy of terbinafine in cutaneous infections, while the clinical relevance of its activities against the other species has yet to be determined. PMID:9593126

  18. Influence of growth conditions on adhesion of yeast Candida spp. and Pichia spp. to stainless steel surfaces.

    Science.gov (United States)

    Tomičić, Ružica; Raspor, Peter

    2017-08-01

    An understanding of adhesion behavior of Candida and Pichia yeast under different environmental conditions is key to the development of effective preventive measures against biofilm-associated infection. Hence in this study we investigated the impact of growth medium and temperature on Candida and Pichia adherence using stainless steel (AISI 304) discs with different degrees of surface roughness (Ra = 25.20-961.9 nm), material typical for the food processing industry as well as medical devices. The adhesion of the yeast strains to stainless steel surfaces grown in Malt Extract broth (MEB) or YPD broth at three temperatures (7 °C, 37 °C, 43 °C for Candida strains and 7 °C, 27 °C, 32 °C for Pichia strains) was assessed by crystal violet staining. The results showed that the nutrient content of medium significantly influenced the quantity of adhered cells by the tested yeasts. Adhesion of C. albicans and C. glabrata on stainless steel surfaces were significantly higher in MEB, whereas for C. parapsilosis and C. krusei it was YPD broth. In the case with P. pijperi and P. membranifaciens, YPD broth was more effective in promoting adhesion than MEB. On the other hand, our data indicated that temperature is a very important factor which considerably affects the adhesion of these yeast. There was also significant difference in cell adhesion on all types of stainless steel surfaces for all tested yeast. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Candida infanticola and Candida spencermartinsiae yeasts: Possible emerging species in cancer patients

    NARCIS (Netherlands)

    Shokohi, T.; Aslani, N.; Ahangarkani, F.; Meyabadi, M.F.; Hagen, F.; Meis, J.F.G.M.; Boekhout, T.; Kolecka, A.; Badali, H.

    2018-01-01

    Opportunistic infections due to Candida species occur frequently in intensive care settings. We investigated the prevalence of Candida species among 65 clinical specimens obtained from 200 cancer patients by phenotypic and molecular (ITS sequencing and AFLP) methods. Among the 65 yeast isolates,

  20. Candida infanticola and Candida spencermartinsiae yeasts: Possible emerging species in cancer patients

    NARCIS (Netherlands)

    Shokohi, T.; Aslani, N.; Ahangarkani, F.; Meyabadi, M.F.; Hagen, F.; Meis, J.F.; Boekhout, T.; Kolecka, A.; Badali, H.

    Opportunistic infections due to Candida species occur frequently especially in intensive care settings. We investigated the prevalence of Candida species among 65 clinical specimens obtained from 200 cancer patients by phenotypic and molecular (ITS sequencing and AFLP) methods. Among the 65 yeast

  1. Candida infanticola and Candida spencermartinsiae yeasts : Possible emerging species in cancer patients

    NARCIS (Netherlands)

    Shokohi, Tahereh; Aslani, Narges; Ahangarkani, Fatemeh; Meyabadi, Masoumeh Fatahi; Hagen, Ferry; Meis, Jacques F.; Boekhout, Teun; Kolecka, Anna; Badali, Hamid

    2017-01-01

    Opportunistic infections due to Candida species occur frequently especially in intensive care settings. We investigated the prevalence of Candida species among 65 clinical specimens obtained from 200 cancer patients by phenotypic and molecular (ITS sequencing and AFLP) methods. Among the 65 yeast

  2. Voice Prosthetic Biofilm Formation and Candida Morphogenic Conversions in Absence and Presence of Different Bacterial Strains and Species on Silicone-Rubber

    NARCIS (Netherlands)

    van der Mei, Henny C.; Buijssen, Kevin J. D. A.; van der Laan, Bernard F. A. M.; Ovchinnikova, Ekatarina; Geertsema-Doornbusch, Gesinda I.; Atema-Smit, Jelly; van de Belt-Gritter, Betsy; Busscher, Henk J.

    2014-01-01

    Morphogenic conversion of Candida from a yeast to hyphal morphology plays a pivotal role in the pathogenicity of Candida species. Both Candida albicans and Candida tropicalis, in combination with a variety of different bacterial strains and species, appear in biofilms on silicone-rubber voice

  3. Multilocus sequence typing confirms synonymy but highlights differences between Candida albicans and Candida stellatoidea.

    NARCIS (Netherlands)

    Jacobsen, M.D.; Boekhout, T.; Odds, F.C.

    2008-01-01

    We used multi-locus sequence typing (MLST) to investigate 35 yeast isolates representing the two genome-sequenced strains plus the type strain of Candida albicans, four isolates originally identified as Candida stellatoidea type I and 28 representing type strains of other species now regarded as

  4. [Biomass composition of thermotolerant yeasts of the genus Candida under elevated cultivation temperatures].

    Science.gov (United States)

    Chistiakova, T I; Dediukhina, E G; Eroshin, V K

    1981-01-01

    The effect of growth temperature on the content of nucleic acids, the content and composition of protein, and the pool of free amino acids and lipids was studied under the conditions of chemostat cultivation of yeast strains at constant flow rates and pO2. The pool of free amino acids in all of the strains decreased with an increase in the temperature of growth. Changes in the content and composition of other cellular components depending on temperature were determined by individual characteristics of the strains. A linear relationship between the content of biomass components and the temperature of growth was found only in Candida scottii. The temperature of yeast cultivation may be used as a factor regulating the pool of free intracellular amino acids and the fatty acids composition of lipids.

  5. [Evaluation of Vitek 2 for the identification of Candida yeasts].

    Science.gov (United States)

    Ochiuzzi, María E; Cataldi, Silvana; Guelfand, Liliana; Maldonado, Ivana; Arechavala, Alicia

    2014-01-01

    The aim of this investigation was to evaluate the performance of Vitek 2 YST cards (bioMérieux, Inc., Hazelwood, MO, USA) for the identification of yeasts of the genus Candida. A total of 168 isolates were analyzed and the results were compared to those of the API 20 C AUX (24%) o API ID 32 C (76%) kits (bioMérieux, Marcy L'Etoile, France). Each isolate was grown in chromogenic agar and in corn meal agar (Oxoid, UK) to observe its micromorphology. C. albicans and C. dublininesis were identified by additional biochemical and molecular tests. The agreement observed was 98.3%. Only three isolates were incorrectly identified by Vitek 2: one strain of C .tropicalis and one strain of C. krusei were identified as C. parapsilosis by YST while one strain of C. krusei was identified with low discrimination. The average time for obtaining results was 18.25 h. Vitek 2 is a simple, safe and useful system for the identification of significant Candida species. Copyright © 2014 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  6. Pigeons and their droppings as reservoirs of Candida and other zoonotic yeasts.

    Science.gov (United States)

    Rosario Medina, Inmaculada; Román Fuentes, Lorena; Batista Arteaga, Miguel; Real Valcárcel, Fernando; Acosta Arbelo, Félix; Padilla Del Castillo, Daniel; Déniz Suárez, Soraya; Ferrer Quintana, Otilia; Vega Gutiérrez, Belinda; Silva Sergent, Freddy; Acosta-Hernández, Begoña

    The importance of pigeons as reservoirs and carriers of Cryptococcus neoformans and other species of this genus is well-known; however, less is known about their role as reservoirs and carriers of other yeasts that impact public health. The present study was performed on Gran Canaria Island to define yeasts other than Cryptococcus spp. that have been reported to impact public health and which could be carried by pigeons. Samples were obtained from 83 pigeon lofts (Columba livia); moreover, 331 crop samples, 331 cloacal samples and 174 dropping samples were collected. In addition, 17 dropping samples were taken from a total of 17 public squares. Samples were inoculated on Sabouraud dextrose agar with chloramphenicol. Different yeast species, i.e. Candida guilliermondii (24.36%), Candida kefyr (1.21%), Saccharomyces cerevisiae (2.43%), and Trichosporon asahii (1.21%) were isolated for the first time from the cloaca. The most frequently isolated yeast from the crop, cloaca and dropping samples from lofts was C. guilliermondii (30.46%, 24.36% and 49.37%, respectively). In addition, for the first time, C. kefyr (3.65%), Candida pelliculosa (2.43%), Candida rugosa (1.21%), T. asahii (3.65%), Trichosporon mucoides (3.65%) and Prototheca wickerhamii (1.21%) were obtained from crop samples; Candida pelliculosa (1.20%), T. asahii (9.63%) and T. mucoides (7.22%) were isolated from dropping samples in the lofts. Candida albicans was the most frequently isolated yeast in dropping samples collected in public squares. It can be assumed that pigeons and their droppings act as carriers and reservoirs of Candida spp. and other zoonotic yeasts. Copyright © 2017 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

  7. Direct identification and recognition of yeast species from clinical material by using albicans ID and CHROMagar Candida plates.

    Science.gov (United States)

    Baumgartner, C; Freydiere, A M; Gille, Y

    1996-02-01

    Two chromogenic media, Albicans ID and CHROMagar Candida agar plates, were compared with a reference medium, Sabouraud-chloramphenicol agar, and standard methods for the identification of yeast species. This study involved 951 clinical specimens. The detection rates for the two chromogenic media for polymicrobial specimens were 20% higher than that for the Sabouraud-chloramphenicol agar plates. The rates of identification of Candida albicans for Albicans ID and CHROMagar Candida agar plates were, respectively, 37.0 and 6.0% after 24 h of incubation and 93.6 and 92.2% after 72 h of incubation, with specificities of 99.8 and 100%. Furthermore, CHROMagar Candida plates identified 13 of 14 Candida tropicalis and 9 of 12 Candida krusei strains after 48 h of incubation.

  8. INVERTASE FROM A CANDIDA STELLATA STRAIN ISOLATED FROM GRAPE: PRODUCTION AND PHYSICO-CHEMICAL CHARACTERIZATION

    Directory of Open Access Journals (Sweden)

    Cristiane Abe Gargel

    2014-08-01

    Full Text Available Invertases are enzymes which hydrolyze the sucrose and are widely employed in food and pharmaceutical industries. In this work, the screening of autochthonous grape yeasts from Brazil was carried out in order to investigate their invertase production potential. Yeasts belonging to Saccharomyces, Hanseniaspora, Sporidiobolus, Issatchenkia, Candida, Cryptococcus and Pichia genera were analyzed by submerged fermentation (SbmF using sucrose as substrate. Among them, Candida stellata strain (N5 strain was selected as the best producer (10.6 U/ml after 48 hours of SbmF. This invertase showed optimal activity at pH 3.0 and 55°C, demonstrating appropriate characters for application in several industrial processes, which includes high temperatures and acid pHs. In addition, this invertase extract presented tolerance to low concentrations of ethanol, suggesting that it could also be suitable for application at the beginning of alcoholic fermentation. These data provide promising prospects of the use of this new invertase in food and ethanol industry.

  9. Hichrom candida agar for identification of candida species

    OpenAIRE

    Baradkar V; Mathur M; Kumar S

    2010-01-01

    Chromogenic media are frequently used in direct and rapid identification of yeasts because different Candida species produce unique colors on these media. We used 60 isolates of Candida species including 30 C. albicans, 10 C. parapsilosis, 11 C. glabrata, five C. tropicalis, and four C. dubliniensis, isolated from various clinical specimens, to evaluate the performance of HiChrome Candida agar. These strains had been identified by germ tube test, morphology on cornmeal agar, chlamydospore for...

  10. Candida middelhoveniana sp. nov., a new yeast species found on the rhizoplane of organically cultivated sugarcane.

    Science.gov (United States)

    Ribeiro, José R de A; Carvalho, Patrícia M B de; Cabral, Anderson de S; Macrae, Andrew; Mendonça-Hagler, Leda C S; Berbara, Ricardo L L; Hagler, Allen N

    2011-10-01

    A novel yeast species within the Metschnikowiaceae is described based on a strain from the sugarcane (Saccharum sp.) rhizoplane of an organically managed farm in Rio de Janeiro, Brazil. The D1/D2 domain of the large subunit ribosomal RNA gene sequence analysis showed that the closest related species were Candida tsuchiyae with 86.2% and Candida thailandica with 86.7% of sequence identity. All three are anamorphs in the Clavispora opuntiae clade. The name Candida middelhoveniana sp. nov. is proposed to accommodate this highly divergent organism with the type strain Instituto de Microbiologia, Universidade Federal do Rio de Janeiro (IMUFRJ) 51965(T) (=Centraalbureau voor Schimmelcultures (CBS) 12306(T), Universidade Federal de Minas Gerais (UFMG)-70(T), DBVPG 8031(T)) and the GenBank/EMBL/DDBJ accession number for the D1/D2 domain LSU rDNA sequence is FN428871. The Mycobank deposit number is MB 519801.

  11. Candida/Candida biofilms. First description of dual-species Candida albicans/C. rugosa biofilm.

    Science.gov (United States)

    Martins, Carlos Henrique Gomes; Pires, Regina Helena; Cunha, Aline Oliveira; Pereira, Cristiane Aparecida Martins; Singulani, Junya de Lacorte; Abrão, Fariza; Moraes, Thais de; Mendes-Giannini, Maria José Soares

    2016-04-01

    Denture liners have physical properties that favour plaque accumulation and colonization by Candida species, irritating oral tissues and causing denture stomatitis. To isolate and determine the incidence of oral Candida species in dental prostheses, oral swabs were collected from the dental prostheses of 66 patients. All the strains were screened for their ability to form biofilms; both monospecies and dual-species combinations were tested. Candida albicans (63 %) was the most frequently isolated microorganism; Candida tropicalis (14 %), Candida glabrata (13 %), Candida rugosa (5 %), Candida parapsilosis (3 %), and Candida krusei (2 %) were also detected. The XTT assay showed that C. albicans SC5314 possessed a biofilm-forming ability significantly higher (p biofilm was less than the total CFU of a monospecies C. albicans biofilm. In contrast to the profuse hyphae verified in monospecies C. albicans biofilms, micrographies showed that the C. albicans/non-albicans Candida biofilms consisted of sparse yeast forms and profuse budding yeast cells that generated a network. These results suggested that C. albicans and the tested Candida species could co-exist in biofilms displaying apparent antagonism. The study provide the first description of C. albicans/C. rugosa mixed biofilm. Copyright © 2016 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  12. Isolation of L-methionine-enriched mutant of a methylotrophic yeast, Candida boidinii No.2201

    International Nuclear Information System (INIS)

    Tani, Y.; Lim, W.J.; Yang, H.C.

    1988-01-01

    Six strains of methylotrophic yeast were examined for production of L-methionine-enriched cells. Candida boidinii (kloeckera sp.) No. 2201,which accumulated 0.54 mg/g-dry cell weight (DCW) of free L-methionine (pool methionine), was selected as the parental strain for breeding L-methionine-rich mutants. Ethionine-resistant mutants were derived from the strain by UV irradiation. A mutant strain, E500-78,which was resistant to 500 μg/ml of DL-ethionine, accumulated 6.02 mg/g-DCW of pool methionine. The culture conditions for mutant strain E500-78 to increase pool methionine accumulation were optimized. As a result, the mutant strain accumulated 8.80 mg/g-DCW of pool methionine and contained 16.02 mg/g-DCW total methionine

  13. The differences in the isoelectric points of biofilm-positive and biofilm-negative Candida parapsilosis strains.

    Science.gov (United States)

    Ruzicka, Filip; Horka, Marie; Hola, Veronika; Kubesova, Anna; Pavlik, Tomas; Votava, Miroslav

    2010-03-01

    The isoelectric points of 39 Candida parapsilosis strains were determined by means of capillary isoelectric focusing. The value of the isoelectric point corresponded well with cell surface hydrophobicity, as well as with the ability to form biofilm in these yeasts. Copyright 2010 Elsevier B.V. All rights reserved.

  14. Bioremediation of acidic oily sludge-contaminated soil by the novel yeast strain Candida digboiensis TERI ASN6.

    Science.gov (United States)

    Sood, Nitu; Patle, Sonali; Lal, Banwari

    2010-03-01

    Primitive wax refining techniques had resulted in almost 50,000 tonnes of acidic oily sludge (pH 1-3) being accumulated inside the Digboi refinery premises in Assam state, northeast India. A novel yeast species Candida digboiensis TERI ASN6 was obtained that could degrade the acidic petroleum hydrocarbons at pH 3 under laboratory conditions. The aim of this study was to evaluate the degradation potential of this strain under laboratory and field conditions. The ability of TERI ASN6 to degrade the hydrocarbons found in the acidic oily sludge was established by gravimetry and gas chromatography-mass spectroscopy. Following this, a feasibility study was done, on site, to study various treatments for the remediation of the acidic sludge. Among the treatments, the application of C. digboiensis TERI ASN6 with nutrients showed the highest degradation of the acidic oily sludge. This treatment was then selected for the full-scale bioremediation study conducted on site, inside the refinery premises. The novel yeast strain TERI ASN6 could degrade 40 mg of eicosane in 50 ml of minimal salts medium in 10 days and 72% of heneicosane in 192 h at pH 3. The degradation of alkanes yielded monocarboxylic acid intermediates while the polycyclic aromatic hydrocarbon pyrene found in the acidic oily sludge yielded the oxygenated intermediate pyrenol. In the feasibility study, the application of TERI ASN6 with nutrients showed a reduction of solvent extractable total petroleum hydrocarbon (TPH) from 160 to 28.81 g kg(-1) soil as compared to a TPH reduction from 183.85 to 151.10 g kg(-1) soil in the untreated control in 135 days. The full-scale bioremediation study in a 3,280-m(2) area in the refinery showed a reduction of TPH from 184.06 to 7.96 g kg(-1) soil in 175 days. Degradation of petroleum hydrocarbons by microbes is a well-known phenomenon, but most microbes are unable to withstand the low pH conditions found in Digboi refinery. The strain C. digboiensis could efficiently degrade

  15. Isolation and identification of a Candida digboiensis strain from an extreme acid mine drainage of the Lignite Mine, Gujarat.

    Science.gov (United States)

    Patel, Mitesh J; Tipre, Devayani R; Dave, Shailesh R

    2009-12-01

    An extremely acidic mine drainage (AMD) water sample was collected in 1998 and 2008 from Panandhro lignite mine, Gujarat, India. The yeast isolated from this sample was identified using mini API identification system, as a member of genus Candida. The major cellular fatty acids detected by FAME from the isolate are C(16:0) and C(18:2) (cis 9,12)/C(18:0alpha) as 25.23 and 19.5%, respectively. The isolate was identified as Candida digboiensis by 18S rRNA gene sequence analysis and designated as Candida digboiensis SRDyeast1. Phylogenetic analysis using D1/D2 variable domains showed that the closest relative of this strain is Candida blankii with 3% divergence. This organism has been reported for the first time from the lignite mine AMD sample, and for cellular fatty acid analysis. This yeast is able to survive in the AMD sample preserved at 10-42 degrees C temperature since last 10 years along with iron oxidizing microorganisms. It can grow in the presence of 40% glucose, 10% NaCl and in the pH range of 1 to 10. The isolate is capable of producing enzymes like protease and lipase. This isolate differs from the type strain Candida digboiensis in as many as six physiological and metabolic characteristics.

  16. Growth conditions for the biomass yield of two methanol utilizing yeast spp. , Candida sp. and Rhodotorula sp

    Energy Technology Data Exchange (ETDEWEB)

    Hong, S.W.

    1976-01-01

    More than 580 MeOH utilizing yeasts were isolated from samples collected throughout South Korea. Of these, 2 strains showed good biomass yield and were selected and tentatively identified as Candida melinii and Rhodotorula glutinis glutinis. Experiments on growth conditions for these 2 species were performed. Optimum pH was 2.6 for Candida, 5.2 for Rhodotorula, and the temperature optimum was 28 to 30/sup 0/ for both. Maximum biomass yield was 4.32 g/L for Candida and 4.2l g/L for Rhodotorula. Optimum concentrations were (NH/sub 4/)/sub 2/SO/sub 4/ 0.3%, Mg/sup +/ 400 ppM, Fe/sup +/ 10 to 15 ppM for Candida and (NH/sub 4/)/sub 2/SO/sub 4/ 0.3% Mg/sup +/ 600 ppM Ca/sup +/ 2 ppM for Rhodotorula. Biotin stimulated Candida. Protein contents of the dry cell biomass were 39.3% in Candida and 44.0% in Rhodotorula.

  17. Study of strains of Candida spp. Isolated from catheters in UHC of Oran (Algeria): Identification and antifungal susceptibility.

    Science.gov (United States)

    Bendjelloul, M; Boucherit-Otmani, Z; Boucherit, K

    2016-09-01

    The increasing incidence of Candida spp., and the vital prognosis often compromise for patients with Candida species make urgent the exact knowledge of their distribution worldwide and exhaust action antifungals currently used in clinical. That why we carry out an epidemiological study of Candida species and testing their susceptibility against two antifungals: amphotericin B and caspofungin. Samplings of peripheral venous catheters (PVC) were carried out from during 8months on the services of Internal medicine, Surgery A and Neonatology of Oran's University Hospital Center (UHC). The study of the susceptibility of Candida species to antifungal agents was performed according to the Clinical Laboratory Standards Institute (CLSI 2008). From 300 samples, 25 yeasts were isolated. The rate of colonization PVC was 8.33% by Candida spp. The most isolated strains were Candida parapsilosis with 64% of cases, followed by Candida albicans (12%) then 8% for Candida glabrata and Candida krusei. However, only 4% of isolates were Candida famata or Candida lusitaniae. Furthermore all isolated strains were susceptible to amphotericin B with Minimum Inhibitory Concentrations (MIC) ranging from 0.25 to 1μg/mL. MIC obtained with caspofungin vary from 0.0625 to 2μg/mL for all strains. Moreover, one strain of C. krusei is resistant to caspofungin with a MIC superior to 8μg/mL. All though caspofungin is at least as effective as amphotericin B, it is better tolerated for the treatment of invasive fungal infections. Copyright © 2016. Published by Elsevier Masson SAS.

  18. Synthetic arylquinuclidine derivatives exhibit antifungal activity against Candida albicans, Candida tropicalis and Candida parapsilopsis

    Directory of Open Access Journals (Sweden)

    Gilbert Ian

    2011-01-01

    Full Text Available Abstract Background Sterol biosynthesis is an essential pathway for fungal survival, and is the biochemical target of many antifungal agents. The antifungal drugs most widely used to treated fungal infections are compounds that inhibit cytochrome P450-dependent C14α-demethylase (CYP51, but other enzymes of this pathway, such as squalene synthase (SQS which catalyses the first committed step in sterol biosynthesis, could be viable targets. The aim of this study was to evaluate the antifungal activity of SQS inhibitors on Candida albicans, Candida tropicalis and Candida parapsilopsis strains. Methods Ten arylquinuclidines that act as SQS inhibitors were tested as antiproliferative agents against three ATCC strains and 54 clinical isolates of Candida albicans, Candida tropicalis and Candida parapsilopsis. Also, the morphological alterations induced in the yeasts by the experimental compounds were evaluated by fluorescence and transmission electron microscopy. Results The most potent arylquinuclidine derivative (3-[1'-{4'-(benzyloxy-phenyl}]-quinuclidine-2-ene (WSP1267 had a MIC50 of 2 μg/ml for all species tested and MIC90 varying from 4 μg/ml to 8 μg/ml. Ultrathin sections of C. albicans treated with 1 μg/ml of WSP1267 showed several ultrastructural alterations, including (a loss of cell wall integrity, (b detachment of the plasma membrane from the fungal cell wall, (c accumulation of small vesicles in the periplasmic region, (d presence of large electron-dense vacuoles and (e significantly increased cell size and cell wall thickness. In addition, fluorescence microscopy of cells labelled with Nile Red showed an accumulation of lipid droplets in the cytoplasm of treated yeasts. Nuclear staining with DAPI revealed the appearance of uncommon yeast buds without a nucleus or with two nuclei. Conclusion Taken together, our data demonstrate that arylquinuclidine derivatives could be useful as lead compounds for the rational synthesis of new

  19. Scanning electron microscopy as a tool for the analysis of colony architecture produced by phenotypic switching of a human pathogenic yeast Candida tropicalis

    International Nuclear Information System (INIS)

    Furlaneto, M C; França, E J G; Moralez, A T P; Ferreira, L C S; Andrade, C G T J; Aragão, P H A

    2012-01-01

    Candida tropicalis has been identified as one of the most prevalent pathogenic yeast species of the Candida-non-albicans group. Phenotypic switching is a biological phenomenon related to the occurrence of spontaneous emergence of colonies with different morphologies that provides variability within colonizing populations in order to adapt to different environments. Currently, studies of the microstructure of switching variant colonies are not subject of extensive research. SEM analysis was used to verify the architecture of whole Candida colonies. The strain 49/07 exhibited a hemispherical shape character, while the strain 335/07 showed a volcano shape with mycelated-edge colony. The ring switch variant is characterized by a highly wrinkled centre and an irregular periphery. The rough phenotype exhibited a three-dimensional architecture and was characterized by the presence of deep central and peripheral depressions areas. The ultrastructural analysis also allowed the observation of the arrangement of individual cells within the colonies. The whole smooth colony consisted entirely of yeast cells. Differently, aerial filaments were found all around the colony periphery of the volcano shape colony. For this colony type the mycelated-edge consisted mainly of hyphae, although yeast cells are also seen. The ring and rough colonies phenotypes comprised mainly yeast cells with the presence of extracellular material connecting neighbouring cells. This study has shown that SEM can be used effectively to examine the microarchitecture of colonies morphotypes of the yeast C. tropicalis and further our understanding of switching event in this pathogen.

  20. Growth of Candida famata and Trichosporon cutaneum on uric acid as the sole source of carbon and energy, a hitherto unknown property of yeasts

    NARCIS (Netherlands)

    Middelhoven, W.J.; Brink, Jolanda A. van den; Veenhuis, M.

    1983-01-01

    Yeast strains capable of utilizing uric acid as the sole source of carbon and energy were isolated from soil by the enrichment culture method. The strains were identified as Candida famata (Harrison) Meyer et Yarrow and Trichosporon cutaneum (De Beurm., Gougerot et Vaucher) Ota. On the subcellular

  1. [Susceptibility of yeasts to antifungal agents in Kaunas University of Medicine Hospital].

    Science.gov (United States)

    Skrodeniene, Erika; Dambrauskiene, Asta; Vitkauskiene, Astra

    2006-01-01

    The aim of this study was to determine the species of yeast and their susceptibility to antifungal agents isolated from clinical specimens of patients treated in Kaunas University of Medicine Hospital. A total of 142 yeasts isolated from various clinical specimens of patients hospitalized in Kaunas University of Medicine Hospital were included in this study. All yeasts were cultivated on Sabouraud dextrose agar and identified using either CHROM agar or API 20C AUX system. The minimum inhibitory concentrations of fluconazole, itraconazole, and amphotericin B were determined by the ATB FUNGUS 2 agar microdilution test. In all clinical specimens except blood, Candida albicans was the most frequently isolated yeast (65.5%, pyeast strains showed resistance to fluconazole. Nearly one-fourth of Candida albicans strains (24.7%) and 23.2% of all isolated yeast strains showed resistance to itraconazole. Almost all of fluconazole-resistant (93.3%) and 12.6% of fluconazole-susceptible yeast were found to be resistant to itraconazole (pyeast strains were susceptible to amphotericin B. Candida albicans strains were significantly frequently resistant to fluconazole than non-albicans Candida species (15.1% and 4.1%, respectively, pyeast isolated in Kaunas University of Medicine Hospital. There was determined that yeasts resistant to fluconazole were commonly resistant to itraconazole too. All isolated yeast strains were susceptible to amphotericin B.

  2. [Effects of 33% grapefruit extract on the growth of the yeast--like fungi, dermatopytes and moulds].

    Science.gov (United States)

    Krajewska-Kułak, E; Lukaszuk, C; Niczyporuk, W

    2001-01-01

    Grapefruit seed extract was discovered by Jacob Harich an american immunologist in 1980. Assessment of the influence of grapefruit extract on the yeast-like fungi strains--Candida albicans growth. Material used in this investigation was ATCC test Candida albicans strains no 10231, 200 of Candida albicans strains, 5 of Candida sp. strains isolated from patients with candidiasis symptoms from different ontocenosis and 12 of dermatophytes and moulds isolated from patients. The susceptibility of the Candida was determined by serial dilution method. It seems that 33% grapefruit extract exert a potent antifungal activity against the yeast like fungi strains and had low activity against dermatophytes and moulds. Further studies in vitro and in vivo on greater number of the yeast-like fungi strains and other fungi species are needed.

  3. Single-cell Protein and Xylitol Production by a Novel Yeast Strain Candida intermedia FL023 from Lignocellulosic Hydrolysates and Xylose.

    Science.gov (United States)

    Wu, Jiaqiang; Hu, Jinlong; Zhao, Shumiao; He, Mingxiong; Hu, Guoquan; Ge, Xiangyang; Peng, Nan

    2018-05-01

    Yeasts are good candidates to utilize the hydrolysates of lignocellulose, the most abundant bioresource, for bioproducts. This study aimed to evaluate the efficiencies of single-cell protein (SCP) and xylitol production by a novel yeast strain, Candida intermedia FL023, from lignocellulosic hydrolysates and xylose. This strain efficiently assimilated hexose, pentose, and cellubiose for cell mass production with the crude protein content of 484.2 g kg -1 dry cell mass. SCP was produced by strain FL023 using corncob hydrolysate and urea as the carbon and nitrogen sources with the dry cell mass productivity 0.86 g L -1  h -1 and the yield of 0.40 g g -1 sugar. SCP was also produced using NaOH-pretreated Miscanthus sinensis straw and corn steep liquor as the carbon and nitrogen sources through simultaneous saccharification and fermentation with the dry cell productivity of 0.23 g L -1  h -1 and yield of 0.17 g g -1 straw. C. intermedia FL023 was tolerant to 0.5 g L -1 furfural, acetic acid, and syringaldehyde in xylitol fermentation and produced 45.7 g L -1 xylitol from xylose with the productivity of 0.38 g L -1  h -1 and the yield of 0.57 g g -1 xylose. This study provides feasible methods for feed and food additive production from the abundant lignocellulosic bioresources.

  4. Assessment of in vitro antifungal activity of preparation ''fin Candimis'' against Candida strains

    Directory of Open Access Journals (Sweden)

    Anna Głowacka

    2013-12-01

    Full Text Available The aim of the study was to assess the antifungal activity of preparation „fin Candimis” (oregano essential oil against yeast-like strains belonging to the genus Candida. During the investigation, there were used up nine Candida albicans strains and ten C. glabrata strains isolated from different clinical material, along with one C. albicans demonstration strain ATCC 90028. The oregano essential oil, utilized in the study, was obtained from fresh leaves of Origanum vulgare L. and bore a trade name „fin Candimis”. According to data yielded by its manufacturer, concentration of pure oregano essential oil in preparation „fin Candimis” totals up to 210 mg/ml. The susceptibility of the Candida strains to preparation „fin Candimis” was assessed by means of the disc-diffusion method, upon the Sabouraud solid medium (after a 24-hour incubation of the cultures at temperature of 37 degrees centigrade; the oregano essential oil had been diluted in 1 ml of DMSO, according to the geometrical progression. A measure of the antifungal activity of preparation „fin Candimis” was the minimal inhibitory concentration (MIC, in terms of the fungus growth. Preparation „fin Candimis” is capable of being applied in the prevention and treatment of candidiasis – alone, or as a natural adjunctive agent. The C. albicans strains are more susceptible to preparation „fin Candimis” in comparison to the C. glabrata ones.

  5. Use of non-saccharomyces Torulaspora delbrueckii yeast strains in winemaking and brewing

    Directory of Open Access Journals (Sweden)

    Tataridis Panagiotis

    2013-01-01

    Full Text Available Selected Saccharomyces yeast strains have been used for more than 150 years in brewing and for several decades in winemaking. They are necessary in brewing because of the boiling of the wort, which results in the death of all yeast cells, with the exception of some Belgian style beers (ex. Lambic, where the wort is left to be colonized by indigenous yeast and bacteria from the environment and ferment naturally. In winemaking their use is also pertinent because they provide regular and timely fermentations, inhibit the growth of indigenous spoilage microorganisms and contribute to the desired sensory characters. Even though the use of selected Saccharomyces strains provides better quality assurance in winemaking in comparison to the unknown microbial consortia in the must, it has been debated for a long time now whether the use of selected industrial Saccharomyces strains results in wines with less sensory complexity and “terroir” character. In previous decades, non-Saccharomyces yeasts were mainly considered as spoilage/problematic yeast, since they exhibited low fermentation ability and other negative traits. In the last decades experiments have shown that there are some non-Saccharomyces strains (Candida, Pichia, Kluyveromyces, Torulaspora, etc which, even though they are not able to complete the fermentation they can still be used in sequential inoculation-fermentation with Saccharomyces to increase sensory complexity of the wines. Through fermentation in a laboratory scale, we have observed that the overall effects of selected Torulaspora delbrueckii yeast strains, is highly positive, leading to products with pronounced sensory complexity and floral/fruity aroma in winemaking and brewing.

  6. Determination of Drug Susceptibility of Candida Strains Isolated From Patients With Recurrent Candida Vulvovaginitis and Investigation of Predisposing Factors of the Disease

    Directory of Open Access Journals (Sweden)

    Minooeianhaghighi MH

    2017-03-01

    Full Text Available Introduction: Recurrent Vulvovaginal Candidiasis RVVC(, which is mostly caused by Candida albicans C. albicans(, is the second common cause of genital tract infection in females. Th purpose of this research was to identify Candida isolates from RVVC, identify predisposing factors and determine antifungal effct of flconazole against Candida strains isolated from the patients. Methods: In this descriptive-laboratory study, 20 patients with confimed diagnosis of RVVC were selected. Yeast isolates were characterized using mycological standard methods, including culture on Sabouraud dextrose agar medium and CHROM agar, germ tube test and polymerase chain reaction-restriction fragment length polymorphism PCR-RFLP( technique. Th susceptibility of Candida isolates against flconazole was determined by microdilution broth method. Results: Th average age of the patients was 29.43 ± 4.63 years. Candida albicans was obtained from 100% of the samples. Th most common clinical sign was vaginal discharge 60%( in females with positive culture. Statistical correlations were observed between parturition frequency and low RVVC occurrence as well as between the previous antifungal therapy and RVVC occurrence. Th mean minimum inhibitory concentration MIC( and minimum fungicidal concentration MFC( of flconazole against diffrent C. albicans strains was determined as 45.3863 µg/mL and 63 µg/mL, respectively. Conclusion: Due to the uncertainty of diagnosis of this disease according to clinical symptoms and also, due to the resistance of Candida species, using culture and molecular methods are recommended as standard methods of diagnosis.

  7. Yeast Identification During Fermentation of Turkish Gemlik Olives.

    Science.gov (United States)

    Mujdeci, Gamze; Arévalo-Villena, María; Ozbas, Z Yesim; Briones Pérez, Ana

    2018-05-01

    Naturally fermented black table olives of the Gemlik variety are one of the most consumed fermented products in Turkey. The objective of this work was to identify yeast strains isolated during their natural fermentation by using Restriction Fragments Lengths Polymorphism-Polimerase Chain Reaction (RFLP-PCR) and DNA sequencing methods. The study also focused on determining the effect of regional differences on yeast microflora of naturally fermented Gemlik olives. A total of 47 yeast strains belonging to 12 different species which had been previously isolated from the natural brine of Akhisar and Iznik-Gemlik cv. olives were characterized by molecular methods. Forty-two of the tested strains could be identified by RFLP-PCR to species level. These yeast species were determined as Candida mycetangi, Candida hellenica, Candida membranaefaciens, Candida famata, Candida pelliculosa, Saccharomyces cerevisiae, and Zygosaccharomyces mrakii. Five strains were identified by DNA sequencing. These strains belonged to three different species: Aureobasidium pullulans, Kloeckera apiculate, and Cryptococcus saitoi. The most frequent species were C. famata and C. pelliculosa in both regions. This work studies the yeasts from Turkish table olives which could prove to be of importance to the food industry in that area. On the other hand, it compares identification by molecular and classical biochemical methods and offers an idea about the differences between the ecosystems of Gemlik olives in the Akhisar (AO) and Iznik (IO) regions. The study could be useful in characterizing a very important product and, in this way, could help to promote its marketing. © 2018 Institute of Food Technologists®.

  8. [Yeast species in vulvovaginitis candidosa].

    Science.gov (United States)

    Nemes-Nikodém, Éva; Tamási, Béla; Mihalik, Noémi; Ostorházi, Eszter

    2015-01-04

    Vulvovaginal candidiasis is the most common mycosis, however, the available information about antifungal susceptibilities of these yeasts is limited. To compare the gold standard fungal culture with a new molecular identification method and report the incidence of yeast species in vulvovaginitis candidosa. The authors studied 370 yeasts isolated from vulvovaginal candidiasis and identified them by phenotypic and molecular methods. The most common species was Candida albicans (85%), followed by Candida glabrata, and other Candida species. At present there are no recommendations for the evaluation of antifungal susceptibility of pathogenic fungal species occurring in vulvovaginal candidiasis and the natural antifungal resistance of the different species is known only. Matrix Assisted Laser Desorption Ionization Time of Flight identification can be used to differentiate the fluconazole resistant Candida dubliniensis and the sensitive Candida albicans strains.

  9. Virgin olive oil yeasts: A review.

    Science.gov (United States)

    Ciafardini, Gino; Zullo, Biagi Angelo

    2018-04-01

    This review summarizes current knowledge on virgin olive oil yeasts. Newly produced olive oil contains solid particles and micro drops of vegetation water in which yeasts reproduce to become the typical microbiota of olive oil. To date, about seventeen yeast species have been isolated from different types of olive oils and their by-products, of which six species have been identified as new species. Certain yeast species contribute greatly to improving the sensorial characteristics of the newly produced olive oil, whereas other species are considered harmful as they can damage the oil quality through the production of unpleasant flavors and triacylglycerol hydrolysis. Studies carried out in certain yeast strains have demonstrated the presence of defects in olive oil treated with Candida adriatica, Nakazawaea wickerhamii and Candida diddensiae specific strains, while other olive oil samples treated with other Candida diddensiae strains were defect-free after four months of storage and categorized as extra virgin. A new acetic acid producing yeast species, namely, Brettanomyces acidodurans sp. nov., which was recently isolated from olive oil, could be implicated in the wine-vinegary defect of the product. Other aspects related to the activity of the lipase-producing yeasts and the survival of the yeast species in the flavored olive oils are also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Treatment with some anti-inflammatory drugs reduces germ tube formation in Candida albicans strains

    Directory of Open Access Journals (Sweden)

    Elena Rusu

    2014-12-01

    Full Text Available Candida albicans is an opportunistic dimorphic fungus that inhabits various host mucosal sites. It can cause both superficial and serious systemic disease. Conversion from the yeast to the hyphal form has been associated with increased virulence and mucosal invasiveness. The aim of this study was to investigate the effect of sodium diclofenac and aspirin on germs tube formation of different Candida albicans strains. Prostaglandins may play an important role in fungal colonization. Nonsteroidal anti-inflammatory drugs are inhibitors of the cyclooxygenase isoenzymes. These drugs specifically block the biosynthesis of mammalian prostaglandins by inhibiting one or both of cyclooxygenase isoenzymes. In tests for germ tube formation sodium diclofenac reduced the filamentation to the 12.5%- 5.1%. In the presence of aspirin the filamentation was reduced up to 85-45% depending on the tested strain. Our results suggest that cyclooxygenase-depending synthesis of fungal prostaglandins is important for morphogenesis and fungal virulence. Inhibitors of cyclooxygenase isoensymes (aspirin and diclofenac are effective in decreasing germ tube formation of Candida albicans.

  11. Biophysical Effects of a Polymeric Biosurfactant in Candida krusei and Candida albicans Cells.

    Science.gov (United States)

    Ferreira, Gabriella Freitas; Dos Santos Pinto, Bruna Lorrana; Souza, Eliene Batista; Viana, José Lima; Zagmignan, Adrielle; Dos Santos, Julliana Ribeiro Alves; Santos, Áquila Rodrigues Costa; Tavares, Priscila Batista; Denadai, Ângelo Márcio Leite; Monteiro, Andrea Souza

    2016-12-01

    This study evaluated the effects of a polymeric biosurfactant produced by Trichosporon montevideense CLOA72 in the adhesion of Candida albicans and Candida krusei cells to human buccal epithelial cells and its interference in biofilm formation by these strains. The biofilm inhibition by biosurfactant (25 mg/mL) in C. krusei and C. albicans in polystyrene was reduced up to 79.5 and 85 %, respectively. In addition, the zeta potential and hydrodynamic diameter of the yeasts altered as a function of the biosurfactant concentration added to the cell suspension. The changes in the cell surface characteristics and the interface modification can contribute to the inhibition of the initial adherence of yeasts cells to the surface. In addition, the analyses of the biofilm matrix and planktonic cell surfaces demonstrated differences in carbohydrate and protein concentrations for the two studied strains, which may contribute to the modulation of cell adhesion or consolidation of biofilms, especially in C. krusei. This study suggests a possible application of the of CLOA72 biosurfactant in inhibiting the adhesion and formation of biofilms on biological surfaces by yeasts of the Candida genus.

  12. Probiotic yeast Saccharomyces boulardii (nom. nud.) modulates adhesive properties of Candida glabrata.

    Science.gov (United States)

    Tomičić, Zorica; Zupan, Jure; Matos, Tadeja; Raspor, Peter

    2016-11-01

    Following the widespread use of immunosuppressive therapy together with broad-spectrum antimycotic therapy, the frequency of mucosal and systemic infections caused by the pathogenic yeast Candida glabrata has increased in the past decades. Due to the resistance of C. glabrata to existing azole drugs, it is very important to look for new strategies helping the treatment of such fungal diseases. In this study, we investigated the effect of the probiotic yeast Saccharomyces boulardii (nom. nud.) on C. glabrata adhesion at different temperatures, pH values, and in the presence of fluconazole, itraconazole and amphotericin B. We also studied the adhesion of C. glabrata co-culture with Candida krusei, Saccharomyces cerevisiae, two bacterial probiotics Lactobacillus rhamnosus and Lactobacillus casei The method used to assess adhesion was crystal violet staining. Our results showed that despite the nonadhesiveness of S. boulardii cells, this probiotic significantly affected the adherence ability of C. glabrata This effect was highly dependent on C. glabrata strain and was either antagonistic or synergistic. Regarding the extrinsic factors, temperature did not indicate any significant influence on this S. boulardii modulatory effect, while at high pH and at increased concentrations of antimycotics, S. boulardii did not manage to repress the adhesion of C. glabrata strains. The experiments of C. glabrata co-cultures with other species showed that the adhesiveness of two separate cultures could not be used to predict the adhesiveness of their co-culture. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. The production of arabitol by a novel plant yeast isolate Candida parapsilosis 27RL-4

    Directory of Open Access Journals (Sweden)

    Kordowska-Wiater Monika

    2017-10-01

    Full Text Available Polyalcohol arabitol can be used in the food and pharmaceutical industries as a natural sweetener, a dental caries reducer, and texturing agent. Environmental samples were screened to isolate effective yeast producers of arabitol. The most promising isolate 27RL-4, obtained from raspberry leaves, was identified genetically and biochemically as Candida parapsilosis. It secreted 10.42– 10.72 g l-1 of product from 20 g l-1 of L-arabinose with a yield of 0.51 - 0.53 g g-1 at 28°C and a rotational speed of 150 rpm. Batch cultures showed that optimal pH value for arabitol production was 5.5. High yields and productivities of arabitol were obtained during incubation of the yeast at 200 rpm, or at 32°C, but the concentrations of the polyol did not exceed 10 g l-1. In modified medium, with reduced amounts of nitrogen compounds and pH 5.5-6.5, lower yeast biomass produced a similar concentration of arabitol, suggesting higher efficiency of yeast cells. This strain also produced arabitol from glucose, with much lower yields. The search for new strains able to successfully produce arabitol is important for allowing the utilization of sugars abundant in plant biomass.

  14. Decolorization of a recalcitrant organic compound (Melanoidin by a novel thermotolerant yeast, Candida tropicalis RG-9

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    Tiwari Soni

    2012-06-01

    Full Text Available Abstract Background Sugarcane distilleries use molasses for ethanol production and generate large volume of effluent containing high biological oxygen demand (BOD and chemical oxygen demand (COD along with melanoidin pigment. Melanoidin is a recalcitrant compound that causes several toxic effects on living system, therefore, may be treated before disposal. The aim of this study was to isolate a potential thermotolerant melanoidin decolorizing yeast from natural resources, and optimized different physico-chemical and nutritional parameters. Results Total 24 yeasts were isolated from the soil samples of near by distillery site, in which isolate Y-9 showed maximum decolorization and identified as Candida tropicalis by Microbial Type Culture Collection (MTCC Chandigarh, India. The decolorization yield was expressed as the decrease in the absorbance at 475 nm against initial absorbance at the same wavelength. Uninoculated medium served as control. Yeast showed maximum decolorization (75% at 45°C using 0.2%, glucose; 0.2%, peptone; 0.05%, MgSO4; 0.01%, KH2PO4; pH-5.5 within 24 h of incubation under static condition. Decolorizing ability of yeast was also confirmed by high performance liquid chromatography (HPLC analysis. Conclusion The yeast strain efficiently decolorized melanoidin pigment of distillery effluent at higher temperature than the other earlier reported strains of yeast, therefore, this strain could also be used at industrial level for melanoidin decolorization as it tolerated a wide range of temperature and pH with very small amount of carbon and nitrogen sources.

  15. Hichrom candida agar for identification of Candida species.

    Science.gov (United States)

    Baradkar, V P; Mathur, M; Kumar, S

    2010-01-01

    Chromogenic media are frequently used in direct and rapid identification of yeasts because different Candida species produce unique colors on these media. We used 60 isolates of Candida species including 30 C. albicans, 10 C. parapsilosis, 11 C. glabrata, five C. tropicalis, and four C. dubliniensis, isolated from various clinical specimens, to evaluate the performance of HiChrome Candida agar. These strains had been identified by germ tube test, morphology on cornmeal agar, chlamydospore formation on tobacco agar and sugar assimilation tests. The sensitivity and specificity results were: C. albicans (96.55 and 96.42%); C. parapsilosis (80 and 98.03%), C. glabrata (90.90 and 88.23%), C. tropicalis (100 and 100%) and C. dubliniensis (60 and 96.55%) respectively. HiChrom Candida agaris medium has been useful and capable of presumptive, rapid identification of Candida species within 48 hours.

  16. Xylitol production from colombian native yeast strains

    Directory of Open Access Journals (Sweden)

    Isleny Andrea Vanegas Córdoba

    2004-07-01

    Full Text Available Xylitol is an alternative sweetener with similar characteristics to sucrose that has become of great interest, due mainly to its safe use in diabetic patients and those deficient in glucose-6-phosphate-dehydrogenase. Its chemical production is expensive and generates undesirable by-products, whereas biotechnological process, which uses different yeasts genera, is a viable production alternative because it is safer and specific. Colombia has a privilege geographic location and offers a great microbial variety, this can be taken advantage of with academic and commercial goals. Because of this, some native microorganisms with potential to produce xylitol were screened in this work. It were isolated 25 yeasts species, from which was possible to identify 84% by the kit API 20C-AUX. Three yeasts: Candida kefyr, C. tropicalis y C. parapsilosis presented greater capacity to degrade xylose compared to the others, therefore they were selected for the later evaluation of its productive capacity. Discontinuous cellular cultures were developed in shaken flasks at 200 rpm and 35°C by 30 hours, using synthetic media with xylose as carbon source. Xylose consumption and xylitol production were evaluated by thin layer chromatography and high performance liquid chromatography. The maximal efficiency were obtained with Candida kefyr and C. tropicalis (Yp/s 0.5 y 0.43 g/g, respectively, using an initial xylose concentration of 20 g/L. Key words: Xylitol, xylose, yeasts, Candida kefyr, C. tropicalis, C. parapsilosis.

  17. Use of the industrial yeast Candida utilis for cadmium sorption

    Czech Academy of Sciences Publication Activity Database

    Kujan, Petr; Prell, Aleš; Šafář, Hynek; Sobotka, Miroslav; Řezanka, Tomáš; Holler, Pavel

    2006-01-01

    Roč. 51, č. 4 (2006), s. 257-260 ISSN 0015-5632 Institutional research plan: CEZ:AV0Z50200510 Keywords : candida utilis * cadmium * yeast Subject RIV: EE - Microbiology, Virology Impact factor: 0.963, year: 2006

  18. Enzymes of Candida tropicalis yeast biodegrading phenol

    OpenAIRE

    Koubková, Zuzana

    2011-01-01

    Effluents of industrial wastewaters from oil refineries, paper mills, dyes, ceramic factories, resins, textiles and plastic contain high concentrations of aromatic compounds, which are toxic to organisms. Degradation of these compounds to tolerant limits before releasing them into the environment is an urgent requirement. Candida tropicalis yeast is an important representative of eucaryotic microorganisms that are able to utilize phenol. During the first phase of phenol biodegradation, cytopl...

  19. MALDI-TOF MS as a tool to identify foodborne yeasts and yeast-like fungi.

    Science.gov (United States)

    Quintilla, Raquel; Kolecka, Anna; Casaregola, Serge; Daniel, Heide M; Houbraken, Jos; Kostrzewa, Markus; Boekhout, Teun; Groenewald, Marizeth

    2018-02-02

    Since food spoilage by yeasts causes high economic losses, fast and accurate identifications of yeasts associated with food and food-related products are important for the food industry. In this study the efficiency of the matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) to identify food related yeasts was evaluated. A CBS in-house MALDI-TOF MS database was created and later challenged with a blinded test set of 146 yeast strains obtained from food and food related products. Ninety eight percent of the strains were correctly identified with log score values>1.7. One strain, Mrakia frigida, gained a correct identification with a score value1.7. Ambiguous identifications were observed due to two incorrect reference mass spectra's found in the commercial database BDAL v.4.0, namely Candida sake DSM 70763 which was re-identified as Candida oleophila, and Candida inconspicua DSM 70631 which was re-identified as Pichia membranifaciens. MALDI-TOF MS can distinguish between most of the species, but for some species complexes, such as the Kazachstania telluris and Mrakia frigida complexes, MALDI-TOF MS showed limited resolution and identification of sibling species was sometimes problematic. Despite this, we showed that the MALDI-TOF MS is applicable for routine identification and validation of foodborne yeasts, but a further update of the commercial reference databases is needed. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Biocontrol activity of four non- and low-fermenting yeast strains against Aspergillus carbonarius and their ability to remove ochratoxin A from grape juice.

    Science.gov (United States)

    Fiori, Stefano; Urgeghe, Pietro Paolo; Hammami, Walid; Razzu, Salvatorico; Jaoua, Samir; Migheli, Quirico

    2014-10-17

    Aspergillus spp. infection of grape may lead to ochratoxin A (OTA) contamination in processed beverages such as wine and grape juice. The aim of the current study was to evaluate the biocontrol potential of two non-fermenting (Cyberlindnera jadinii 273 and Candida friedrichii 778) and two low-fermenting (Candida intermedia 235 and Lachancea thermotolerans 751) yeast strains against the pathogenic fungus and OTA-producer Aspergillus carbonarius, and their ability to remove OTA from grape juice. Two strains, 235 and 751, showed a significant ability to inhibit A. carbonarius both on grape berries and in in vitro experiments. Neither their filtrate nor their autoclaved filtrate culture broth was able to prevent consistently pathogen growth. Volatile organic compounds (VOCs) produced by all four selected yeasts were likely able to consistently prevent pathogen sporulation in vitro. VOCs produced by the non-fermenting strain 778 also significantly reduced A. carbonarius vegetative growth. Three yeast strains (235, 751, and 778) efficiently adsorbed artificially spiked OTA from grape juice, while autoclaving treatment improved OTA adsorption capacity by all the four tested strains. Biological control of A. carbonarius and OTA-decontamination using yeast is proposed as an approach to meet the Islamic dietary laws concerning the absence of alcohol in halal beverages. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  1. Yeasts from Scarlet ibises (Eudocimus ruber): A focus on monitoring the antifungal susceptibility of Candida famata and closely related species.

    Science.gov (United States)

    Brilhante, Raimunda Sâmia Nogueira; Silva, Aline Lobão da; Monteiro, Frederico Ozanan Barros; Guedes, Glaucia Morgana de Melo; Sales, Jamille Alencar; Oliveira, Jonathas Sales de; Maia Junior, José Erisvaldo; Miranda, Stefânia Araújo; Sidrim, José Júlio Costa; Alencar, Lucas Pereira de; Castelo-Branco, Débora Souza Collares Maia; Cordeiro, Rossana de Aguiar; Pereira Neto, Waldemiro de Aquino; Rocha, Marcos Fábio Gadelha

    2017-10-01

    This study aimed to identify yeasts from the gastrointestinal tract of scarlet ibises (Eudocimus ruber) and from plant material collected from the environment where they live. Then, the isolates phenotypically identified as Candida famata were submitted to molecular identification of their closely related species and evaluated for their antifungal susceptibility and possible resistance mechanisms to antifungal drugs. Cloacal swabs from 20 scarlet ibises kept in captivity at Mangal das Garças Park (Brazil), pooled stool samples (n = 20) and samples of trunks and hollow of trees (n = 20) obtained from their enclosures were collected. The samples were seeded on Sabouraud agar supplemented with chloramphenicol. The 48 recovered isolates were phenotypically identified as 15 Candida famata, 13 Candida catenulata, 2 Candida intermedia, 1 Candida lusitaniae, 2 Candida guilliermondii, 1 Candida kefyr, 1 Candida amapae, 1 Candida krusei, 8 Trichosporon spp., and 4 Rhodotorula spp. The C. famata isolates were further identified as 3 C. famata, 8 Debaryomyces nepalensis, and 4 C. palmioleophila. All C. famata and C. palmioleophila were susceptible to caspofungin and itraconazole, while one D. nepalensis was resistant to fluconazole and voriconazole. This same isolate and another D. nepalensis had lower amphotericin B susceptibility. The azole resistant strain had an increased efflux of rhodamine 6G and an alteration in the membrane sterol content, demonstrating multifactorial resistance mechanism. Finally, this research shows that scarlet ibises and their environment harbor C. famata and closely related species, including antifungal resistant isolates, emphasizing the need of monitoring the antifungal susceptibility of these yeast species. © The Author 2017. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Isolation and Characterization of a Catabolite Repression-Insensitive Mutant of a Methanol Yeast, Candida boidinii A5, Producing Alcohol Oxidase in Glucose-Containing Medium

    OpenAIRE

    Sakai, Yasuyoshi; Sawai, Tohru; Tani, Yoshiki

    1987-01-01

    Mutants exhibiting alcohol oxidase (EC 1.1.3.13) activity when grown on glucose in the presence of methanol were found among 2-deoxyglucose-resistant mutants derived from a methanol yeast, Candida boidinii A5. One of these mutants, strain ADU-15, showed the highest alcohol oxidase activity in glucose-containing medium. The growth characteristics and also the induction and degradation of alcohol oxidase were compared with the parent strain and mutant strain ADU-15. In the parent strain, initia...

  3. Hichrom candida agar for identification of candida species

    Directory of Open Access Journals (Sweden)

    Baradkar V

    2010-01-01

    Full Text Available Chromogenic media are frequently used in direct and rapid identification of yeasts because different Candida species produce unique colors on these media. We used 60 isolates of Candida species including 30 C. albicans, 10 C. parapsilosis, 11 C. glabrata, five C. tropicalis, and four C. dubliniensis, isolated from various clinical specimens, to evaluate the performance of HiChrome Candida agar. These strains had been identified by germ tube test, morphology on cornmeal agar, chlamydospore formation on tobacco agar and sugar assimilation tests. The sensitivity and specificity results were: C. albicans (96.55 and 96.42%; C. parapsilosis (80 and 98.03%, C. glabrata (90.90 and 88.23%, C. tropicalis (100 and 100% and C. dubliniensis (60 and 96.55% respectively. HiChrom Candida agaris medium has been useful and capable of presumptive, rapid identification of Candida species within 48 hours.

  4. Antifungal activity of four honeys of different types from Algeria against pathogenic yeast: Candida albicans and Rhodotorula sp.

    OpenAIRE

    Ahmed Moussa; Djebli Noureddine; Aissat Saad; Meslem Abdelmelek; Benhalima Abdelkader

    2012-01-01

    Objective: To evaluate the antifungal activity of four honeys of different types from Algeria against pathogenic yeast i.e. Candida albicans (C. albicans) and Rhodotorula sp. Methods: Four Algeria honeys of different botanical origin were analyzed to test antifungal effect against C. albicans, and Rhodotorula sp. Different concentrations (undiluted, 10%, 30%, 50% and 70% w/v) of honey were studied in vitro for their antifugal activity using C. albicans and Rhodotorula sp. as fungal strains...

  5. Spectrophotometric evaluation of selenium binding by Saccharomyces cerevisiae ATCC MYA-2200 and Candida utilis ATCC 9950 yeast.

    Science.gov (United States)

    Kieliszek, Marek; Błażejak, Stanisław; Płaczek, Maciej

    2016-05-01

    In this study, the ability of selenium binding the biomas of Saccharomyces cerevisiae ATCC MYA-2200 and Candida utilis ATCC 9950 was investigated. Sodium selenite(IV) salts were added to the experimental media at concentrations of 10, 20, 40, and 60 mg Se(4+) L(-1). In the tested concentration range, one concentration reported a significant reduction in the biomass yield of both yeast strains. Intense growth was observed for C. utilis yeast, which reached the highest biomass yield of 15 gd.w.L(-1) after 24h cultivation in the presence of 10mg Se(4+) L(-1). Based on the use of spectrophotometric method for the determination of selenium content by using Variamine Blue as a chromogenic agent, efficient accumulation of this element in the biomass of the investigated yeast was observed. The highest amount of selenium, that is, 5.64 mg Se(4+)gd.w.(-1), was bound from the environment by S. cerevisiae ATCC MYA-2200 cultured in the presence of 60 mg Se(4+) L(-1) medium 72h Slightly less amount, 5.47 mg Se(4+) gd.w.(-1), was absorbed by C. utilis ATCC 9950 during similar cultural conditions. Based on the results of the biomass yield and the use of selenium from the medium, it can be observed that yeasts of the genus Candida are more efficient in binding this element, and this property finds practical application in the production of selenium-enriched yeast. Copyright © 2016 Elsevier GmbH. All rights reserved.

  6. De Novo Assembly of Candida sojae and Candida boidinii Genomes, Unexplored Xylose-Consuming Yeasts with Potential for Renewable Biochemical Production

    Science.gov (United States)

    Borelli, Guilherme; José, Juliana; Teixeira, Paulo José Pereira Lima; dos Santos, Leandro Vieira

    2016-01-01

    Candida boidinii and Candida sojae yeasts were isolated from energy cane bagasse and plague-insects. Both have fast xylose uptake rate and produce great amounts of xylitol, which are interesting features for food and 2G ethanol industries. Because they lack published genomes, we have sequenced and assembled them, offering new possibilities for gene prospection. PMID:26769937

  7. Resistencia de levaduras del género Candida al fluconazol Candida yeast´s resistance to fluconazol

    Directory of Open Access Journals (Sweden)

    Carlos Hernando Gómez Quintero

    2010-12-01

    Full Text Available Las infecciones por levaduras del género Candida sp. son cada vez más prevalentes en pacientes hospitalizados, especialmente en grupos de mayor riesgo como pueden ser pacientes con neoplasia hematológica bajo tratamiento de quimioterapia y en cuidados intensivos. La resistencia de Candida sp. representa un reto terapéutico que deja un menor número de posibilidades para el tratamiento de estas infecciones que se caracterizan, a su vez, por una alta morbimortalidad. Esta revisión describe los mecanismos de resistencia de Candida sp. a fluconazol y los factores de riesgo para la adquisición de éstos.Yeast infections of the genus Candida sp are becoming more prevalent in hospitalized patients, especially in high risk groups such as patients with hematologic malignancy undergoing chemotherapy and in intensive care units. Candida sp's resistance represents a therapeutic challenge that leaves fewer opportunities for the treatment of these infections which are characterized by high morbidity and mortality. This review describes Candida sp's resistance mechanisms to fluconazole and the risk factors for their acquisition.

  8. Investigating cross-contamination by yeast strains from dental solid waste to waste-handling workers by DNA sequencing.

    Science.gov (United States)

    Vieira, Cristina Dutra; Tagliaferri, Thaysa Leite; de Carvalho, Maria Auxiliadora Roque; de Resende-Stoianoff, Maria Aparecida; Holanda, Rodrigo Assuncao; de Magalhães, Thais Furtado Ferreira; Magalhães, Paula Prazeres; Dos Santos, Simone Gonçalves; de Macêdo Farias, Luiz

    2018-04-01

    Trying to widen the discussion on the risks associated with dental waste, this study proposed to investigate and genetically compare yeast isolates recovered from dental solid waste and waste workers. Three samples were collected from workers' hands, nasal mucosa, and professional clothing (days 0, 30, and 180), and two from dental waste (days 0 and 180). Slide culture, microscopy, antifungal drug susceptibility, intersimple sequence repeat analysis, and amplification and sequencing of internal transcribed spacer regions were performed. Yeast strains were recovered from all waste workers' sites, including professional clothes, and from waste. Antifungal susceptibility testing demonstrated that some yeast recovered from employees and waste exhibited nonsusceptible profiles. The dendrogram demonstrated the presence of three major clusters based on similarity matrix and UPGMA grouping method. Two branches displayed 100% similarity: three strains of Candida guilliermondii isolated from different employees, working in opposite work shifts, and from diverse sites grouped in one part of branch 1 and cluster 3 that included two samples of Candida albicans recovered from waste and the hand of one waste worker. The results suggested the possibility of cross-contamination from dental waste to waste workers and reinforce the need of training programs focused on better waste management routines. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  9. Molecular Characterization of Yeast Strains Isolated from Different Sources by Restriction Fragment Length Polymorphism

    International Nuclear Information System (INIS)

    Ali, M. S.; Latif, Z.

    2016-01-01

    Various molecular techniques like analysis of the amplified rDNA internal transcribed spacers (ITS), intragenic spacers and total ITS region analysis by restriction fragment length polymorphism (RFLP) has been introduced for yeast identification but there are limited databases to identify yeast species on the basis of 5.8S rDNA. In this study, twenty nine yeast strains from various sources including spoiled fruits, vegetables, foodstuffs, and concentrated juices were characterized by PCR-RFLP. PCR-RFLP has been used to characterize yeasts present in different spoiled food samples after isolation of the yeasts. By using this technique, the isolated yeast strains were characterized by direct 5.8S-ITS rDNA region amplification. RFLP analysis was applied to each of the amplification products (varied from 400bp to 800bp) detected, and the corresponding yeast identifications were made according to each specific restriction patterns obtained after treatment with two endonucleases TaqI and HaeIII which yielded a specific banding pattern for each species. For further confirmation amplified products of eleven selected isolates were sequenced and blast on NCBI. Both RFLP and sequence analyses of the strains with accession nos. KF472163, KF472164, KF472165, KF472166, KF472167, KF472168, KF472169, KF472170, KF472171, KF472172, KF472173 gave significantly similar results. The isolates were found to belong five different yeast species including; Candida spp., Pichia spp., Kluyveromyces spp., Clavispora spp. and Hanseniaspora spp. This method provides a fast, easy, reliable and authentic way for determining yeast population present in different type of samples, as compared to traditional characterization technique. (author)

  10. Yeast strains and methods of use thereof

    OpenAIRE

    Goddard, Matthew Robert; Gardner, Richard Clague; Anfang, Nicole

    2013-01-01

    The present invention relates to yeast strains and, in particular, to yeast stains for use in fermentation processes. The invention also relates to methods of fermentation using the yeast strains of the invention either alone or in combination with other yeast strains. The invention thither relates to methods for the selection of yeast strains suitable for fermentation cultures by screening for various metabolic products and the use of specific nutrient sources.

  11. Distribution of yeast-like fungi at a university hospital in Turkey.

    Science.gov (United States)

    Ece, Gulfem

    2014-12-01

    The increased life span has led to application of more invasive procedures for diagnosis and treatment of particularly immunosuppressed individuals. This situation drew more attention to fungal infections due to existence of yeast-like fungi. Candida infections have increased due to transplant in patients, prolonged intensive care unit (ICU) stays, and invasive procedures. Recently, identification of yeast-like fungi as well as antifungal susceptibility test has been gaining more importance. In our study, we aimed to evaluate the distribution of yeast-like fungi strains isolated from blood, urine, wound and respiratory specimens, which were sent from various departments of Izmir University School of Medicine University Hospital. The 262 yeast strains (of 13860 clinical specimens), isolated during 30.05.2012-20.05.2013, which were sent from various departments of Izmir University School of Medicine to Medical Microbiology Laboratory, were included in this study. Blood, wound, respiratory (sputum, tracheal secretion), and urine specimens were cultivated on blood agar and Sabouraud dextrose agar and incubated for 24-48 hours at 37°C. The isolates were cultivated on CHROMagar Candida and Cornmeal Tween 80 medium for identification. Besides, the automatized Vitek version 2.0 system was used for identification of the yeast strains as well as the antifungal susceptibility of blood culture strains. A total of 262 strains, isolated from the Anesthesiology and Reanimation Unit, as well as from the departments of Hematology, Urology, Infectious Diseases, Gynecology and Obstetrics, and Ear Nose and Throat, were included in this study. The most common isolated yeast-like species was Candida albicans. C. parapsilosis was the most common yeast-like fungus isolated from blood cultures. All the blood culture strains were susceptible to amphotericin B, flucytosine, fluconazole and voriconazole. Candida strains isolated from newborns, elderly patients, and intensive care patients

  12. Use of CHROMagar Candida for the presumptive identification of Candida species directly from clinical specimens in resource-limited settings

    Science.gov (United States)

    Nadeem, Sayyada Ghufrana; Hakim, Shazia Tabassum; Kazmi, Shahana Urooj

    2010-01-01

    Introduction Identification of yeast isolated from clinical specimens to the species level has become increasingly important. Ever-increasing numbers of immuno-suppressed patients, a widening range of recognized pathogens, and the discovery of resistance to antifungal drugs are contributing factors to this necessity. Material and methods A total of 487 yeast strains were studied for the primary isolation and presumptive identification, directly from clinical specimen. Efficacy of CHROMagar Candida has been evaluated with conventional methods including morphology on Corn meal–tween 80 agar and biochemical methods by using API 20 C AUX. Results The result of this study shows that CHROMagar Candida can easily identify three species of Candida on the basis of colonial color and morphology, and accurately differentiate between them i.e. Candida albicans, Candida tropicalis, and Candida krusei. The specificity and sensitivity of CHROMagar Candida for C. albicans calculated as 99%, for C. tropicalis calculated as 98%, and C. krusei it is 100%. Conclusion The data presented supports the use of CHROMagar Candida for the rapid identification of Candida species directly from clinical specimens in resource-limited settings, which could be very helpful in developing appropriate therapeutic strategy and management of patients. PMID:21483597

  13. Use of CHROMagar Candida for the presumptive identification of Candida species directly from clinical specimens in resource-limited settings

    Directory of Open Access Journals (Sweden)

    Sayyada Ghufrana Nadeem

    2010-02-01

    Full Text Available Introduction: Identification of yeast isolated from clinical specimens to the species level has become increasingly important. Ever-increasing numbers of immuno-suppressed patients, a widening range of recognized pathogens, and the discovery of resistance to antifungal drugs are contributing factors to this necessity. Material and methods: A total of 487 yeast strains were studied for the primary isolation and presumptive identification, directly from clinical specimen. Efficacy of CHROMagar Candida has been evaluated with conventional methods including morphology on Corn meal–tween 80 agar and biochemical methods by using API 20 C AUX. Results: The result of this study shows that CHROMagar Candida can easily identify three species of Candida on the basis of colonial color and morphology, and accurately differentiate between them i.e. Candida albicans, Candida tropicalis, and Candida krusei. The specificity and sensitivity of CHROMagar Candida for C. albicans calculated as 99%, for C. tropicalis calculated as 98%, and C. krusei it is 100%. Conclusion: The data presented supports the use of CHROMagar Candida for the rapid identification of Candida species directly from clinical specimens in resource-limited settings, which could be very helpful in developing appropriate therapeutic strategy and management of patients.

  14. Use of CHROMagar Candida for the presumptive identification of Candida species directly from clinical specimens in resource-limited settings.

    Science.gov (United States)

    Nadeem, Sayyada Ghufrana; Hakim, Shazia Tabassum; Kazmi, Shahana Urooj

    2010-02-09

    Identification of yeast isolated from clinical specimens to the species level has become increasingly important. Ever-increasing numbers of immuno-suppressed patients, a widening range of recognized pathogens, and the discovery of resistance to antifungal drugs are contributing factors to this necessity. A total of 487 yeast strains were studied for the primary isolation and presumptive identification, directly from clinical specimen. Efficacy of CHROMagar Candida has been evaluated with conventional methods including morphology on Corn meal-tween 80 agar and biochemical methods by using API 20 C AUX. The result of this study shows that CHROMagar Candida can easily identify three species of Candida on the basis of colonial color and morphology, and accurately differentiate between them i.e. Candida albicans, Candida tropicalis, and Candida krusei. The specificity and sensitivity of CHROMagar Candida for C. albicans calculated as 99%, for C. tropicalis calculated as 98%, and C. krusei it is 100%. The data presented supports the use of CHROMagar Candida for the rapid identification of Candida species directly from clinical specimens in resource-limited settings, which could be very helpful in developing appropriate therapeutic strategy and management of patients.

  15. Identification of Yeast Species In the Oral Cavity of Iranian Soldiers By Disk Diffusion Method

    Directory of Open Access Journals (Sweden)

    M. Imami

    2008-02-01

    Full Text Available Background:The disk diffusion method for identification of yeasts species was performed based on different but distinct susceptibilities of yeasts spp.to chemicals:janus green, ethidium bromide,2,3,5-triphenyltetrazolium chloride, brilliant green, cycloheximide and rhodamine 6G. Methods: Atotal of 568 Iranian soldiers went under study for isolation and identification of Yeast species from their oral cavity. Asterile swab was used for each individual and specimens were collected from the nasopharynx region, then inoculated to petri dishes containing Sabouraud Dextrose Agar and incubated for 48 hrs at 37 °C. All colonies were counted and stocked in distilled water and stored in a refrigerator for further analysis. The yeasts were identified by the “disk diffusion test” [6,8]. This is a simple, rapid, accurate, and inexpensive technique presented by Sobczak [8]. By this method we identified yeast species within 24-48 hrs. Results: 51.4% of petri dishes were positive for yeast species and 318 strains were identified. Candida albicans, Candida kefyr, Candida tropicalis and Candida guilliermondii were the most common yeast species isolated from the oral cavity of soldiers. Conclusion: We used this method because of its simplicity and other beneficial characteristics for rapid identification of large and numerous isolates and the results were compared with other morphological characters such as chlamydospore and germ tube production. In addition,we used some type strains (Candida parapsilosis: PTCC 5089,Candida tropicalis: PTCC 5028,Saccharomyces cerevisiae:PTCC 5052,Candida lipolytica: PTCC 5063,Candida lipolytica:PTCC 5064,and the results were acceptable.

  16. Typing and virulence factors of food-borne Candida spp. isolates.

    Science.gov (United States)

    Rajkowska, Katarzyna; Kunicka-Styczyńska, Alina

    2018-08-20

    Food-borne yeasts, excluding yeasts used as starter cultures, are commonly considered as food spoilage microorganisms. However, the incidence of non-C. albicans Candida (NCAC) infections has increased considerably over the past two decades. Although 15 Candida species are frequently identified as pathogens, a threat to human from food-borne Candida is poorly recognized. In the present study food-borne NCAC were characterized for the virulence factors, known to be associated with yeast pathogenicity. All food-borne strains in planktonic forms and 89% in biofilm structures represented biotypes established for C. albicans, and 61% demonstrated hemolytic activity. 56-94% of food-borne isolates formed biofilms on glass and biomaterials at a level comparable to clinical C. albicans. Nine out of eighteen tested food-borne NCAC strains (C. krusei, C. lusitaniae, C. famata, C. colliculosa, C. parapsilosis, C. tropicalis) showed similarity to clinical C. albicans in terms of their biotypes and the tested virulence factors, allocating them in a group of risk of potential pathogens. However, their capacity to grow at 37 °C seems to be the preliminary criterion in the study of potential virulence of food-borne yeasts. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Thailandins A and B, New Polyene Macrolactone Compounds Isolated from Actinokineospora bangkokensis Strain 44EHW(T), Possessing Antifungal Activity against Anthracnose Fungi and Pathogenic Yeasts.

    Science.gov (United States)

    Intra, Bungonsiri; Greule, Anja; Bechthold, Andreas; Euanorasetr, Jirayut; Paululat, Thomas; Panbangred, Watanalai

    2016-06-29

    Two new polyene macrolactone antibiotics, thailandins A, 1, and B, 2, were isolated from the fermentation broth of rhizosphere soil-associated Actinokineospora bangkokensis strain 44EHW(T). The new compounds from this strain were purified using semipreparative HPLC and Sephadex LH-20 gel filtration while following an antifungal activity guided fractionation. Their structures were elucidated through spectroscopic techniques including UV, HR-ESI-MS, and NMR. These compounds demonstrated broad spectrum antifungal activity against fungi causing anthracnose disease (Colletotrichum gloeosporioides DoA d0762, Colletotrichum gloeosporiodes DoA c1060, and Colletotrichum capsici DoA c1511) as well as pathogenic yeasts (Candida albicans MT 2013/1, Candida parasilopsis DKMU 434, and Cryptococcus neoformans MT 2013/2) with minimum inhibitory concentrations ranging between 16 and 32 μg/mL. This is the first report of polyene antibiotics produced by Actinokineospora species as bioactive compounds against anthracnose fungi and pathogenic yeast strains.

  18. In vitro anidulafungin activity against yeasts – system and disseminated mycosis pathogens

    Directory of Open Access Journals (Sweden)

    A. B. Kulko

    2015-01-01

    Full Text Available We analyzed susceptibility to anidulafungin of yeasts clinical strains of Candida (14 species, Cryptococcus (1 species, Geotrichum (1 species, Rhodotorula (1 species and Saccharomyces (1 species. We revealed high anidulafungin activity against Candida spp., both common species and rare pathogens of candidiasis. It was found that over 99 % of Candida strains do not have an acquired resistance mechanisms to anidulafungin (microbiological criteria. The anidulafungin is not active against strains of Cryptococcus neoformans and Rhodotorula mucilaginosa.

  19. Comparative behaviour of yeast strains for ethanolic fermentation of culled apple juice.

    Science.gov (United States)

    Modi, D R; Garg, S K; Johri, B N

    1998-07-01

    The culled apple juice contained (% w/v): nitrogen, 0.036; total sugars, 11.6 and was of pH 3.9. Saccharomyces cerevisiae NCIM 3284, Pichia kluyeri and Candida krusei produced more ethanol from culled apple juice at its optimum initial pH 4.5, whereas S. cerevisiae NCIM 3316 did so at pH 5.0. An increase in sugar concentration of apple juice from natural 11.6% to 20% exhibited enhanced ethanol production and improved fermentation efficiency of both the S. cerevisiae strains, whereas P. kluyveri and C. krusei produced high ethanol at 11.6% and 16.0% sugar levels, respectively. Urea was stimulatory for ethanol production as well as fermentation efficiency of the yeast strains under study.

  20. Identification of yeast strains isolated from marcha in Sikkim, a microbial starter for amylolytic fermentation.

    Science.gov (United States)

    Tsuyoshi, Naoko; Fudou, Ryosuke; Yamanaka, Shigeru; Kozaki, Michio; Tamang, Namrata; Thapa, Saroj; Tamang, Jyoti P

    2005-03-15

    Marcha or murcha is a traditional amylolytic starter used to produce sweet-sour alcoholic drinks, commonly called jaanr in the Himalayan regions of India, Nepal, Bhutan, and Tibet (China). The aim of this study was to examine the microflora of marcha collected from Sikkim in India, focusing on yeast flora and their roles. Twenty yeast strains were isolated from six samples of marcha and identified by genetic and phenotypic methods. They were first classified into four groups (Group I, II, III, and IV) based on physiological features using an API test. Phylogenetic, morphological, and physiological characterization identified the isolates as Saccharomyces bayanus (Group I); Candida glabrata (Group II); Pichia anomala (Group III); and Saccharomycopsis fibuligera, Saccharomycopsis capsularis, and Pichia burtonii (Group IV). Among them, the Group I, II, and III strains produced ethanol. The isolates of Group IV had high amylolytic activity. Because all marcha samples tested contained both starch degraders and ethanol producers, it was hypothesized that all four groups of yeast (Group I, II, III, and IV) contribute to starch-based alcohol fermentation.

  1. Evaluation of Yeast Biomass (Candida utilis in a Practical Diet for Rainbow Trout (Oncorhynchus mykiss

    Directory of Open Access Journals (Sweden)

    J.S. Goddard

    1999-01-01

    Full Text Available A yeast, Candida utilis, cultured on a substrate derived from a mixture of peat moss and fish processing waste, was substituted for fish meal in a practical diet for rainbow trout, Oncorhynchus mykiss. The formulated diets were isonitrogenous (40% crude protein and isoealoric (gross energy 20 kJ per g dry matter. During a 50-day feeding trial fish tripled in weight, and there were no significant differences in the mean final weights of groups of fish fed diets in which 0%, 25% and 35% of fishmeal had been replaced by yeast biomass. Diets containing yeast were palatable, as determined by food intake, and were highly digestible for protein. Carcass analysis revealed that the fish fed with yeast biomass had slightly higher crude protein and ash contents, and lower lipid levels than those of the control group. Significant reductions were recorded in food conversion efficiency as the yeast content of the diets increased. The results indicate the potential for partial replacement of fish meal (between 25-35% by Candida utilis biomass in feeds formulated for rainbow trout.

  2. Streptococcus thermophilus and its biosurfactants inhibit adhesion by Candida spp. on silicone rubber

    NARCIS (Netherlands)

    Busscher, HJ; vanHoogmoed, CG; GeertsemaDoornbusch, GI; vanderKuijlBooij, M; vanderMei, HC

    1997-01-01

    The adhesion of yeasts, two Candida albicans and two Candida tropicalis strains isolated from naturally colonized voice prostheses, to silicone rubber with and without a salivary conditioning film in the absence and presence of adhering Streptococcus thermophilus B, a biosurfactant-releasing dairy

  3. Mini-chromosomes among danish Candida glabrata isolates originated through two different mechanisms

    DEFF Research Database (Denmark)

    Ahmad, K. M.; Ishchuk, O.; Hellborg, L.

    2012-01-01

    We analyzed 201 strains of the pathogenic yeast Candida glabrata from patients, mainly suffering from systemic infection, at Danish hospitals during 1985 – 1999. Our analysis showed that these strains were closely related but exhibited large karyotype polymorphism. Nine strains contained mini-chr...

  4. Identification and susceptibility of clinical isolates of Candida spp. to killer toxins

    Directory of Open Access Journals (Sweden)

    E. Robledo-Leal

    2018-02-01

    Full Text Available Abstract Although invasive infections and mortality caused by Candida species are increasing among compromised patients, resistance to common antifungal agents is also an increasing problem. We analyzed 60 yeasts isolated from patients with invasive candidiasis using a PCR/RFLP strategy based on the internal transcribed spacer (ITS2 region to identify different Candida pathogenic species. PCR analysis was performed from genomic DNA with a primer pair of the ITS2-5.8S rDNA region. PCR-positive samples were characterized by RFLP. Restriction resulted in 23 isolates identified as C. albicans using AlwI, 24 isolates as C. parapsilosis using RsaI, and 13 as C. tropicalis using XmaI. Then, a group of all isolates were evaluated for their susceptibility to a panel of previously described killer yeasts, resulting in 75% being susceptible to at least one killer yeast while the remaining were not inhibited by any strain. C. albicans was the most susceptible group while C. tropicalis had the fewest inhibitions. No species-specific pattern of inhibition was obtained with this panel of killer yeasts. Metschnikowia pulcherrima, Pichia kluyveri and Wickerhamomyces anomalus were the strains that inhibited the most isolates of Candida spp.

  5. Diversity and physiological characterization of D-xylose-fermenting yeasts isolated from the Brazilian Amazonian Forest.

    Science.gov (United States)

    Cadete, Raquel M; Melo, Monaliza A; Dussán, Kelly J; Rodrigues, Rita C L B; Silva, Silvio S; Zilli, Jerri E; Vital, Marcos J S; Gomes, Fátima C O; Lachance, Marc-André; Rosa, Carlos A

    2012-01-01

    This study is the first to investigate the Brazilian Amazonian Forest to identify new D-xylose-fermenting yeasts that might potentially be used in the production of ethanol from sugarcane bagasse hemicellulosic hydrolysates. A total of 224 yeast strains were isolated from rotting wood samples collected in two Amazonian forest reserve sites. These samples were cultured in yeast nitrogen base (YNB)-D-xylose or YNB-xylan media. Candida tropicalis, Asterotremella humicola, Candida boidinii and Debaryomyces hansenii were the most frequently isolated yeasts. Among D-xylose-fermenting yeasts, six strains of Spathaspora passalidarum, two of Scheffersomyces stipitis, and representatives of five new species were identified. The new species included Candida amazonensis of the Scheffersomyces clade and Spathaspora sp. 1, Spathaspora sp. 2, Spathaspora sp. 3, and Candida sp. 1 of the Spathaspora clade. In fermentation assays using D-xylose (50 g/L) culture medium, S. passalidarum strains showed the highest ethanol yields (0.31 g/g to 0.37 g/g) and productivities (0.62 g/L · h to 0.75 g/L · h). Candida amazonensis exhibited a virtually complete D-xylose consumption and the highest xylitol yields (0.55 g/g to 0.59 g/g), with concentrations up to 25.2 g/L. The new Spathaspora species produced ethanol and/or xylitol in different concentrations as the main fermentation products. In sugarcane bagasse hemicellulosic fermentation assays, S. stipitis UFMG-XMD-15.2 generated the highest ethanol yield (0.34 g/g) and productivity (0.2 g/L · h), while the new species Spathaspora sp. 1 UFMG-XMD-16.2 and Spathaspora sp. 2 UFMG-XMD-23.2 were very good xylitol producers. This study demonstrates the promise of using new D-xylose-fermenting yeast strains from the Brazilian Amazonian Forest for ethanol or xylitol production from sugarcane bagasse hemicellulosic hydrolysates.

  6. Clinical strains of Lactobacillus reduce the filamentation of Candida albicans and protect Galleria mellonella against experimental candidiasis.

    Science.gov (United States)

    Rossoni, Rodnei Dennis; Dos Santos Velloso, Marisol; Figueiredo, Lívia Mara Alves; Martins, Carolina Pistille; Jorge, Antonio Olavo Cardoso; Junqueira, Juliana Campos

    2018-05-01

    Candida albicans is the most common human fungal pathogen and can grow as yeast or filaments, depending on the environmental conditions. The filamentous form is of particular interest because it can play a direct role in adherence and pathogenicity. Therefore, the purpose of this study was to evaluate the effects of three clinical strains of Lactobacillus on C. albicans filamentation as well as their probiotic potential in pathogen-host interactions via an experimental candidiasis model study in Galleria mellonella. We used the reference strain Candida albicans ATCC 18804 and three clinical strains of Lactobacillus: L. rhamnosus strain 5.2, L. paracasei strain 20.3, and L. fermentum strain 20.4. First, the capacity of C. albicans to form hyphae was tested in vitro through association with the Lactobacillus strains. After that, we verified the ability of these strains to attenuate experimental candidiasis in a Galleria mellonella model through a survival curve assay. Regarding the filamentation assay, a significant reduction in hyphae formation of up to 57% was observed when C. albicans was incubated in the presence of the Lactobacillus strains, compared to a control group composed of only C. albicans. In addition, when the larvae were pretreated with Lactobacillus spp. prior to C. albicans infection, the survival rate of G. mellonela increased in all experimental groups. We concluded that Lactobacillus influences the growth and expression C. albicans virulence factors, which may interfere with the pathogenicity of these microorganisms.

  7. An original method for producing acetaldehyde and diacetyl by yeast fermentation

    Directory of Open Access Journals (Sweden)

    Irina Rosca

    Full Text Available Abstract In this study a natural culture medium that mimics the synthetic yeast peptone glucose medium used for yeast fermentations was designed to screen and select yeasts capable of producing high levels of diacetyl and acetaldehyde. The presence of whey powder and sodium citrate in the medium along with manganese and magnesium sulfate enhanced both biomass and aroma development. A total of 52 yeasts strains were cultivated in two different culture media, namely, yeast peptone glucose medium and yeast acetaldehyde-diacetyl medium. The initial screening of the strains was based on the qualitative reaction of the acetaldehyde with Schiff's reagent (violet color and diacetyl with Brady's reagent (yellow precipitate. The fermented culture media of 10 yeast strains were subsequently analyzed by gas chromatography to quantify the concentration of acetaldehyde and diacetyl synthesized. Total titratable acidity values indicated that a total titratable acidity of 5.5 °SH, implying culture medium at basic pH, was more favorable for the acetaldehyde biosynthesis using strain D15 (Candida lipolytica; 96.05 mg L-1 acetaldehyde while a total titratable acidity value of 7 °SH facilitated diacetyl flavor synthesis by strain D38 (Candida globosa; 3.58 mg L-1 diacetyl. Importantly, the results presented here suggest that this can be potentially used in the baking industry.

  8. Identification of salivary components that induce transition of hyphae to yeast in Candida albicans.

    Science.gov (United States)

    Leito, Jelani T D; Ligtenberg, Antoon J M; Nazmi, Kamran; Veerman, Enno C I

    2009-10-01

    Candida albicans, the major human fungal pathogen, undergoes a reversible morphological transition from single yeast cells to pseudohyphae and hyphae filaments. The hyphae form is considered the most invasive form of the fungus. The purpose of this study is to investigate the effect of saliva on hyphae growth of C. albicans. Candida albicans hyphae were inoculated in Roswell Park Memorial Institute medium with whole saliva, parotid saliva or buffer mimicking the saliva ion composition, and cultured for 18 h at 37 degrees C under aerobic conditions with 5% CO(2). Whole saliva and parotid saliva induced transition to yeast growth, whereas the culture with buffer remained in the hyphae form. Parotid saliva was fractionated on a reverse-phase C8 column and each fraction was tested for inducing transition to yeast growth. By immunoblotting, the salivary component in the active fraction was identified as statherin, a phosphoprotein of 43 amino acids that has been implicated in remineralization of the teeth. Synthetically made statherin induced transition of hyphae to yeast. By deletion of five amino acids at the negatively charged N-terminal site (DpSpSEE), yeast-inducing activity and binding to C. albicans were increased. In conclusion, statherin induces transition to yeast of C. albicans hyphae and may thus contribute to the oral defense against candidiasis.

  9. Xylitol from rice husks by acid hydrolysis and Candida yeast fermentation

    Directory of Open Access Journals (Sweden)

    Magale K. D. Rambo

    2013-01-01

    Full Text Available An investigation was conducted into the production of xylose by acid hydrolysis of rice husks and its subsequent bioconversion to xylitol. The parameters were optimised using the response surface methodology. The fermentation stage took place with the aid of the yeast species Candida guilliermondii and Candida tropicalis. An evaluation of the influence of several biomass pre-treatments was also performed. The effects of the acid concentration and hydrolysate pH on xylitol global yield were also assessed, and the highest yield of xylitol was 64.0% (w/w. The main products, xylose and xylitol, were identified and quantified by means of liquid chromatography.

  10. Group X hybrid histidine kinase Chk1 is dispensable for stress adaptation, host-pathogen interactions and virulence in the opportunistic yeast Candida guilliermondii.

    Science.gov (United States)

    Navarro-Arias, María J; Dementhon, Karine; Defosse, Tatiana A; Foureau, Emilien; Courdavault, Vincent; Clastre, Marc; Le Gal, Solène; Nevez, Gilles; Le Govic, Yohann; Bouchara, Jean-Philippe; Giglioli-Guivarc'h, Nathalie; Noël, Thierry; Mora-Montes, Hector M; Papon, Nicolas

    2017-09-01

    Hybrid histidine kinases (HHKs) progressively emerge as prominent sensing proteins in the fungal kingdom and as ideal targets for future therapeutics. The group X HHK is of major interest, since it was demonstrated to play an important role in stress adaptation, host-pathogen interactions and virulence in some yeast and mold models, and particularly Chk1, that corresponds to the sole group X HHK in Candida albicans. In the present work, we investigated the role of Chk1 in the low-virulence species Candida guilliermondii, in order to gain insight into putative conservation of the role of group X HHK in opportunistic yeasts. We demonstrated that disruption of the corresponding gene CHK1 does not influence growth, stress tolerance, drug susceptibility, protein glycosylation or cell wall composition in C. guilliermondii. In addition, we showed that loss of CHK1 does not affect C. guilliermondii ability to interact with macrophages and to stimulate cytokine production by human peripheral blood mononuclear cells. Finally, the C. guilliermondii chk1 null mutant was found to be as virulent as the wild-type strain in the experimental model Galleria mellonella. Taken together, our results demonstrate that group X HHK function is not conserved in Candida species. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  11. Evaluation of Urinary Tract Infections Due to Candida Species

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    Yeser Karaca Derici

    2016-02-01

    Full Text Available Aim: Although urinary tract infections often caused by bacteria, fungal etiology is detected in a significant number of infections in which Candida is the leading cause. In this study we aimed to evaluate the distribution of Candida strains isolated from urine samples in our hospital. Material and Method: Candida species were identified based on germ tube test, colony morphology on chrom agar Candida (Biomerieux, France and API ID32C AUX (Biomerieux, France commercial kit. Data were analyzed with SPSS 15.0 software for data analysis. Results: During March 2011-March 2014 a total of 109662 urine cultures were evaluated and 24364 samples revealed significant growth. Of the significant growth detected 24364 (22% samples 1096 (4.5% were defined as yeasts. The isolates most frequently detected in this study were C. albicans (50.5%, C. tropicalis (15.9%, C. glabrata (12.7%, C. parapsilosis (7.2%, C. kefyr (5.8%, C. krusei (5.5%. The highest yeast growth was observed in anesthesia intensive care unit. Discussion: In our study, the most frequently isolated species of yeast in the urine was C. albicans. Determination of Candida species and their clinical distributions in hospitals is very important in terms of giving direction to the treatment and measures to be taken.

  12. 40 CFR 180.1289 - Candida oleophila Strain O; exemption from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Candida oleophila Strain O; exemption... FOOD Exemptions From Tolerances § 180.1289 Candida oleophila Strain O; exemption from the requirement... the microbial pesticide, Candida oleophila Strain O, on apples and pears when applied/used as a post...

  13. Development of intra-strain self-cloning procedure for breeding baker's yeast strains.

    Science.gov (United States)

    Nakagawa, Youji; Ogihara, Hiroyuki; Mochizuki, Chisato; Yamamura, Hideki; Iimura, Yuzuru; Hayakawa, Masayuki

    2017-03-01

    Previously reported self-cloning procedures for breeding of industrial yeast strains require DNA from other strains, plasmid DNA, or mutagenesis. Therefore, we aimed to construct a self-cloning baker's yeast strain that exhibits freeze tolerance via an improved self-cloning procedure. We first disrupted the URA3 gene of a prototrophic baker's yeast strain without the use of any marker gene, resulting in a Δura3 homozygous disruptant. Then, the URA3 gene of the parental baker's yeast strain was used as a selection marker to introduce the constitutive TDH3 promoter upstream of the PDE2 gene encoding high-affinity cyclic AMP phosphodiesterase. This self-cloning procedure was performed without using DNA from other Saccharomyces cerevisiae strains, plasmid DNA, or mutagenesis and was therefore designated an intra-strain self-cloning procedure. Using this self-cloning procedure, we succeeded in producing self-cloning baker's yeast strains that harbor the TDH3p-PDE2 gene heterozygously and homozygously, designated TDH3p-PDE2 hetero and TDH3p-PDE2 homo strains, respectively. These self-cloning strains expressed much higher levels of PDE2 mRNA than the parental strain and exhibited higher viability after freeze stress, as well as higher fermentation ability in frozen dough, when compared with the parental strain. The TDH3p-PDE2 homo strain was genetically more stable than the TDH3p-PDE2 hetero strain. These results indicate that both heterozygous and homozygous strains of self-cloning PDE2-overexpressing freeze-tolerant strains of industrial baker's yeast can be prepared using the intra-strain self-cloning procedure, and, from a practical viewpoint, the TDH3p-PDE2 homo strain constructed in this study is preferable to the TDH3p-PDE2 hetero strain for frozen dough baking. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  14. Occurrence of Killer Yeast Strains in Fruit and Berry Wine Yeast Populations

    Directory of Open Access Journals (Sweden)

    Gintare Gulbiniene

    2004-01-01

    Full Text Available Apple, cranberry, chokeberry and Lithuanian red grape wine yeast populations were used for the determination of killer yeast occurrence. According to the tests of the killer characteristics and immunity the isolated strains were divided into seven groups. In this work the activity of killer toxins purified from some typical strains was evaluated. The analysed strains produced different amounts of active killer toxin and some of them possessed new industrially significant killer properties. Total dsRNA extractions in 11 killer strains of yeast isolated from spontaneous fermentations revealed that the molecular basis of the killer phenomenon was not only dsRNAs, but also unidentified genetic determinants.

  15. Biomodification of edible fats and oils by yeasts; Kobo ni yoru shokuyo yushi no seibutsugakuteki kaishitsu

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, K.; Endo, Y. [Tohoku University, Sendai (Japan). Faculty of Agriculture

    1995-10-20

    Lipid-biomodification ability was examined for yeasts isolated from soil using culture medium containing beef tallow (2%). Some yeasts, e.g. Candida, Trichosporon and Rhodotorula species were able to grow on fats and oils. Fatty acid and triacylglycerol compositions were modified in lipids of some strains. Candida sp. MIS-1 and YM1-1 preferentially produced oleic acid. Candida sp. MIS-1 had high level of triacylglycerol with a melting point like olive oil. Fatty acid composition of lipids in Candida lipolytica IAM4948 and Rhodotorula sp. AO3-5 was similar to that of cacao butter. Yeast oils obtained from C. lipolytica provided the melting characterization different from beef tallow. 30 refs., 3 figs., 7 tabs.

  16. Candida auris: emergence and epidemiology of a highly pathogenic yeast

    Directory of Open Access Journals (Sweden)

    Paula Slomp Santos

    2017-09-01

    Full Text Available Candida auris is a multidrug-resistant emerging yeast, which was responsible for healthcare-associated infection outbreaks, and was cataloged as a new species in 2009, after being isolated from a patient’s ear canal secretion in Japan. Since the notification of this first occurrence, numerous cases have been reported throughout the world, including Brazil. C. auris affects mainly inpatients, patients in intensive care units, exposed to broad-spectrum antifungal medications and who make use of vascular catheters. Currently, this yeast is one of the main responsible for invasive infections in hospitals and has been cause of concern by authorities and organs due to its rapid dissemination and difficult treatment caused by its low susceptibility to antifungal agents traditionally used in clinical practice. As a contributor to the severity of infections associated with C. auris, the transmission mechanism is still unknown, which implies in a lack of control of the microorganism and high mortality rates. Thus, this literature review presents relevant information in order to alert the importance of C. auris as an etiological agent of systemic infections, as well as its epidemiology and the real challenges of the treatment. Keywords: Candida auris; candidiasis; candidemia; multidrug-resistance; biofilm; epidemiology; diagnosis

  17. Yeast casein kinase 2 governs morphology, biofilm formation, cell wall integrity, and host cell damage of Candida albicans.

    Science.gov (United States)

    Jung, Sook-In; Rodriguez, Natalie; Irrizary, Jihyun; Liboro, Karl; Bogarin, Thania; Macias, Marlene; Eivers, Edward; Porter, Edith; Filler, Scott G; Park, Hyunsook

    2017-01-01

    The regulatory networks governing morphogenesis of a pleomorphic fungus, Candida albicans are extremely complex and remain to be completely elucidated. This study investigated the function of C. albicans yeast casein kinase 2 (CaYck2p). The yck2Δ/yck2Δ strain displayed constitutive pseudohyphae in both yeast and hyphal growth conditions, and formed enhanced biofilm under non-biofilm inducing condition. This finding was further supported by gene expression analysis of the yck2Δ/yck2Δ strain which showed significant upregulation of UME6, a key transcriptional regulator of hyphal transition and biofilm formation, and cell wall protein genes ALS3, HWP1, and SUN41, all of which are associated with morphogenesis and biofilm architecture. The yck2Δ/yck2Δ strain was hypersensitive to cell wall damaging agents and had increased compensatory chitin deposition in the cell wall accompanied by an upregulation of the expression of the chitin synthase genes, CHS2, CHS3, and CHS8. Absence of CaYck2p also affected fungal-host interaction; the yck2Δ/yck2Δ strain had significantly reduced ability to damage host cells. However, the yck2Δ/yck2Δ strain had wild-type susceptibility to cyclosporine and FK506, suggesting that CaYck2p functions independently from the Ca+/calcineurin pathway. Thus, in C. albicans, Yck2p is a multifunctional kinase that governs morphogenesis, biofilm formation, cell wall integrity, and host cell interactions.

  18. Reclassification of Candida guilliermondii FTI 20037 as Candida tropicalis based on molecular phylogenetic analysis Reclassificação de Candida guilliermondii FTI 20037 como Candida tropicalis baseada na análise filogenética molecular

    Directory of Open Access Journals (Sweden)

    Luanne Helena Augusto Lima

    2003-11-01

    Full Text Available Yeasts of the genus Candida are of clinical importance and also have many industrial applications, mainly in the food industry. The yeast Candida guilliermondii FTI 20037 has been extensively studied in order to establish a biotechnological process for the production of xylitol. The goal of this study was to verify the taxonomic classification of this strain based on the analysis of rDNA sequences and the xyl1 gene. DNA fragments from these sequences were amplified by PCR and BLAST analysis revealed strong identity with the corresponding sequences from Candida tropicalis. Based on these results, we propose that C. guilliermondii FTI 20037 must be reclassified as C. tropicalis.As leveduras do gênero Candida possuem tanto importância clínica como diversas aplicações industriais, principalmente na indústria de alimentos. A levedura Candida guilliermondii FTI 20037 tem sido exaustivamente estudada pois pretende-se utilizá-la no estabelecimento de um processo biotecnológico para a produção de xilitol. O objetivo deste trabalho foi verificar a classificação taxonômica desta levedura por análise de sequências do rDNA e do gene xyl1. Fragmentos correspondentes a estas regiões foram amplificados por PCR e a análise destas sequências por BLAST revelou alta identidade com sequências correspondentes de Candida tropicalis. Estes resultados nos levam a propor que C. guilliermondii FTI 20037 deva ser reclassificada como C. tropicalis.

  19. The Slime Production by Yeasts Isolated from Subclinical Mastitic Cows

    Directory of Open Access Journals (Sweden)

    Süheyla Türkyılmaz

    2010-01-01

    Full Text Available The aim of this study was to isolate yeasts from subclinical mastitic cows and to investigate the slime production by the isolated yeasts. The material used in this study included 339 milk samples from 152 dairy cattle with subclinical mastitis. Milk was plated onto blood agar, MacConkey agar and Sabouraud dextrose agar. Forty-one samples (12.1% of total milk samples were found positive for the yeast by API 20 C AUX identification system. The isolated yeasts were classified into four genera of Candida, Trichosporon, Cryptococcus and Saccharomyces. The Candida species were following: C. krusei, C. kefyr, C. guilliermondii, C. famata, C. rugosa and C. utulis. Other yeasts were identified as Trichosporon mucoides, T. asahii, Cryptococcus laurentii, C.  neoformans and Saccharomyces cerevisiae. Slime production was tested on Congo red brain heart infusion agar and evaluated according to Congo red phenomenon. Fifteen (36.6% strains were slime factor positive: seven were C. krusei, four C. kefyr, one C. guilliermondii, one C. famata, one T. asahii, and one C. laurentii. The results of the present study indicate that yeast mastitis is significant for causing economic losses and slime production is mostly found in non-albicans Candida species. Therefore, non-albicans Candida species should be examined for slime production.

  20. Genome and transcriptome analysis of the food-yeast Candida utilis.

    Directory of Open Access Journals (Sweden)

    Yasuyuki Tomita

    Full Text Available The industrially important food-yeast Candida utilis is a Crabtree effect-negative yeast used to produce valuable chemicals and recombinant proteins. In the present study, we conducted whole genome sequencing and phylogenetic analysis of C. utilis, which showed that this yeast diverged long before the formation of the CUG and Saccharomyces/Kluyveromyces clades. In addition, we performed comparative genome and transcriptome analyses using next-generation sequencing, which resulted in the identification of genes important for characteristic phenotypes of C. utilis such as those involved in nitrate assimilation, in addition to the gene encoding the functional hexose transporter. We also found that an antisense transcript of the alcohol dehydrogenase gene, which in silico analysis did not predict to be a functional gene, was transcribed in the stationary-phase, suggesting a novel system of repression of ethanol production. These findings should facilitate the development of more sophisticated systems for the production of useful reagents using C. utilis.

  1. Biochemical characterization of recombinant dihydroorotate dehydrogenase from the opportunistic pathogenic yeast Candida albicans

    DEFF Research Database (Denmark)

    Zameitat, E.; Gojkovic, Zoran; Knecht, Wolfgang

    2006-01-01

    Candida albicans is the most prevalent yeast pathogen in humans, and recently it has become increasingly resistant to the current antifungal agents. In this study we investigated C. albicans dihydroorotate dehydrogenase (DHODH, EC 1.3.99.11), which catalyzes the fourth step of de novo pyrimidine...

  2. New lager yeast strains generated by interspecific hybridization.

    Science.gov (United States)

    Krogerus, Kristoffer; Magalhães, Frederico; Vidgren, Virve; Gibson, Brian

    2015-05-01

    The interspecific hybrid Saccharomyces pastorianus is the most commonly used yeast in brewery fermentations worldwide. Here, we generated de novo lager yeast hybrids by mating a domesticated and strongly flocculent Saccharomyces cerevisiae ale strain with the Saccharomyces eubayanus type strain. The hybrids were characterized with respect to the parent strains in a wort fermentation performed at temperatures typical for lager brewing (12 °C). The resulting beers were analysed for sugar and aroma compounds, while the yeasts were tested for their flocculation ability and α-glucoside transport capability. These hybrids inherited beneficial properties from both parent strains (cryotolerance, maltotriose utilization and strong flocculation) and showed apparent hybrid vigour, fermenting faster and producing beer with higher alcohol content (5.6 vs 4.5 % ABV) than the parents. Results suggest that interspecific hybridization is suitable for production of novel non-GM lager yeast strains with unique properties and will help in elucidating the evolutionary history of industrial lager yeast.

  3. Comparison of the Vitek 2 yeast susceptibility system with CLSI microdilution for antifungal susceptibility testing of fluconazole and voriconazole against Candida spp., using new clinical breakpoints and epidemiological cutoff values.

    Science.gov (United States)

    Pfaller, Michael A; Diekema, Daniel J; Procop, Gary W; Rinaldi, Michael G

    2013-09-01

    A commercially available, fully automated yeast susceptibility test system (Vitek 2; bioMérieux, Marcy d'Etoile, France) was compared in 3 different laboratories with the Clinical and Laboratory Standards Institute (CLSI) reference microdilution (BMD) method by testing 2 quality control strains, 10 reproducibility strains, and 425 isolates of Candida spp. against fluconazole and voriconazole. Reference CLSI BMD MIC endpoints and Vitek 2 MIC endpoints were read after 24 hours and 9.1-27.1 hours incubation, respectively. Excellent essential agreement (within 2 dilutions) between the reference and Vitek 2 MICs was observed for fluconazole (97.9%) and voriconazole (96.7%). Categorical agreement (CA) between the 2 methods was assessed using the new species-specific clinical breakpoints (CBPs): susceptible (S) ≤2 μg/mL, susceptible dose-dependent (SDD) 4 μg/mL, and resistant (R) ≥8 μg/mL for fluconazole and Candida albicans, Candida tropicalis, and Candida parapsilosis and ≤32 μg/mL (SDD), ≥64 μg/mL (R) for Candida glabrata; S ≤0.12 μg/mL, SDD 0.25-0.5 μg/mL, R ≥1 μg/mL for voriconazole and C. albicans, C. tropicalis, and C. parapsilosis, and ≤0.5 μg/mL (S), 1 μg/mL (SDD), ≥2 μg/mL (R) for Candida krusei. The epidemiological cutoff value (ECV) of 0.5 μg/mL for voriconazole and C. glabrata was used to differentiate wild-type (WT; MIC ≤ ECV) from non-WT (MIC > ECV) strains of this species. Due to the lack of CBPs for the less common species, the ECVs for fluconazole and voriconazole, respectively, were used for Candida lusitaniae (2 μg/mL and 0.03 μg/mL), Candida dubliniensis (0.5 μg/mL and 0.03 μg/mL), Candida guilliermondii (8 μg/mL and 0.25 μg/mL), and Candida pelliculosa (4 μg/mL and 0.25 μg/mL) to categorize isolates of these species as WT and non-WT. CA between the 2 methods was 96.8% for fluconazole and 96.5% for voriconazole with less than 1% very major errors and 1.3-3.0% major errors. The Vitek 2 yeast susceptibility system

  4. Yeast production from cellulase hydrolyzed furfural industrial waste. II. Conditions for the cultivation of yeast

    Energy Technology Data Exchange (ETDEWEB)

    1977-01-01

    Three yeast strains, Candida AS 2-121, C. utilis AS 2-1180, and C. tropicalis AS 2-637 were selected as being capable of growing on cellulase-hydrolyzed furfural industrial waste. Cell mass yields with respect to C source were approximately 50%. Fermentation conditions are given.

  5. Mastite por leveduras em bovinos leiteiros do Sul do Estado de Minas Gerais, Brasil Mastitis caused by yeasts in dairy herds in the South of the Minas Gerais State, Brazil

    Directory of Open Access Journals (Sweden)

    Geraldo Márcio da Costa

    2008-10-01

    Full Text Available O objetivo deste trabalho foi estudar a freqüência de infecções intramamárias ocasionadas por leveduras a partir de amostras de leite (n=1710 coletadas em 40 rebanhos leiteiros do Estado de Minas Gerais. Cinqüenta e seis estirpes de leveduras do gênero Candida e uma linhagem de Trichosporon loubieri foram isoladas. Candida albicans foi a espécie dominante (28,1% das cepas, seguida por Candida parapsilosis (19,3%, Candida catenulata (14,0%, Candida glabrata (14,0% e Candida tropicalis (8,8%. Infecções mistas foram detectadas em 29,8% das vacas levedura-positivas. Amostras positivas para leveduras foram predominantemente obtidas (84% de vacas com mastite subclínica. A baixa taxa de isolamento de leveduras sugere que estes microrganismos não são relevantes para mastite bovina na região estudada.The objective of this study was to report the frequency of intramammary infections by yeasts, in Minas Gerais State, from milk samples (n = 1710 collected in 40 dairy herds. Fifty six yeast strains of the genus Candida and one strain of Trichosporon loubieri were isolated. Candida albicans was the dominant species (28.1% of the strains, followed by Candida parapsilosis (19.3%, Candida catenulata (14.0%, Candida glabrata (14.0%, Candida tropicalis (8.8%. Mixed infections were detected in 29.8% of yeast-positive cows. The yeast infection was more frequent (84% in cows with subclinical mastitis. The low rate of isolation of yeasts suggests that these microorganisms are not relevant to bovine mastitis in the studied region.

  6. FUNCTIONAL PROPERTIES OF YEASTS ISOLATED FROM SOME NIGERIAN TRADITIONAL FERMENTED FOODS

    Directory of Open Access Journals (Sweden)

    Tolulope P. Alakeji

    2015-04-01

    Full Text Available Yeasts play important roles in confering some desirable qualities such as nutritional value in traditional fermented foods. This study was carried out to investigate the potentials of yeasts isolated from some Nigerian traditional fermented foods for functional characteristics such as growth at pH 2.5 and 2% bile salts concentration and ability to lower cholesterol in culture medium. A total of 40 yeast strains were isolated from burukutu, ogi and pito. They were characterized phenotypically. Fifteen strains were selected based on the ability to tolerate pH 2.5 and 2% bile salts and they were further identified using API 20C AUX (Biomerieux, France to be Debaryomyces hansenii (5, Candida krusei (4, Candida glabrata (2, Candida colliculosa (1, Pichia anomala (1, Pichia farinosa (1 and Pichia membranefaciens (1. At pH 2.5, C. glabrata SA2 showed the highest increase in viable cells count after 24h (6.31 log10 cfu ml-1 while the most sensitive strain was P. membranefaciens BA2 (0.70 log10 cfu ml-1. P. membranefaciens BA2 survived in 2% bile salts than other yeast strains, with viable cell increase of 0.84 log10 cfu ml-1 after 24 h while the least tolerance was observed for D. hansenii OA1 with an increase in viable cells of 7.76 log10 cfu ml-1. C. krusei OB1 exhibited the greatest reduction of cholesterol of 91.34% while the least reduction of 24.28% was observed for D. hansenii OA1 after 48h incubation. The yeast strains in this study demonstrated functional attributes which can be employed as dietary adjuncts for the development of non-dairy beverages with hypocholesterolemic attributes.

  7. Direct identification and recognition of yeast species from clinical material by using albicans ID and CHROMagar Candida plates.

    OpenAIRE

    Baumgartner, C; Freydiere, A M; Gille, Y

    1996-01-01

    Two chromogenic media, Albicans ID and CHROMagar Candida agar plates, were compared with a reference medium, Sabouraud-chloramphenicol agar, and standard methods for the identification of yeast species. This study involved 951 clinical specimens. The detection rates for the two chromogenic media for polymicrobial specimens were 20% higher than that for the Sabouraud-chloramphenicol agar plates. The rates of identification of Candida albicans for Albicans ID and CHROMagar Candida agar plates w...

  8. Effect of lipolytic activity of Candida adriatica, Candida diddensiae and Yamadazyma terventina on the acidity of extra-virgin olive oil with a different polyphenol and water content.

    Science.gov (United States)

    Ciafardini, G; Zullo, B A

    2015-05-01

    Previous microbiological research demonstrated the presence of a rich micro-flora composed mainly of yeasts in the suspended fraction of freshly produced olive oil. Some of the yeasts are considered harmful as they can damage the quality of the olive oil through the hydrolysis of the triacylglycerols. Present research has demonstrated that the lipolytic activity of some lipase-producer strains belonging to a yeast species called Candida adriatica, Candida diddensiae and Yamadazyma terventina can be modulated by the water and the polyphenol content of olive oil. Laboratory tests highlighted a substantial increase in free fatty acid in the inoculated olive oil characterized by high water content and low polyphenol concentration. The acidity of the olive oil samples containing 0.06% and 0.31% of water increased significantly by 33% in the lipase-producer yeast strains tested during a period of 2 weeks of incubation at 30 °C. All other yeasts showed strong lipolytic activity in the presence of 1.31% of water - the only exception to this was the C. adriatica 1985 strain. The phenolic compounds typical of olive oil represent another important factor able to condition the viability and the lipolytic activity of the lipase-producer yeasts. From the tests performed on the olive oil characterized by an increasing content of total polyphenols equal to 84, 150 and 510 mg per kg of oil, the percentage of the lipase-producer yeasts able to hydrolyse the triacylglycerols was respectively 100%, 67% and 11%. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Complete DNA sequence of the linear mitochondrial genome of the pathogenic yeast Candida parapsilosis

    DEFF Research Database (Denmark)

    Nosek, J.; Novotna, M.; Hlavatovicova, Z.

    2004-01-01

    The complete sequence of the mitochondrial DNA of the opportunistic yeast pathogen Candida parapsilosis was determined. The mitochondrial genome is represented by linear DNA molecules terminating with tandem repeats of a 738-bp unit. The number of repeats varies, thus generating a population...

  10. 'Killer' character of yeasts isolated from ethanolic fermentations

    Directory of Open Access Journals (Sweden)

    Ceccato-Antonini Sandra Regina

    1999-01-01

    Full Text Available The number of killer, neutral and sensitive yeasts was determined from strains isolated from substrates related to alcoholic fermentations. From 113 isolates, 24 showed killer activity against NCYC 1006 (standard sensitive strain, while 30 were sensitive to NCYC 738 (standard killer strain, and 59 had no reaction in assays at 25-27°C. Two wild yeast strains of Saccharomyces cerevisiae and one of Candida colliculosa were tested against 10 standard killer strains and one standard sensitive strain in a cell x cell and well-test assays at four different pHs. None of the isolates displayed strong killer activity or were sensitive to the standard strains. All belonged to the neutral type. It was concluded that although the number of killer strains was high, this character cannot be used to protect ethanol fermentation processes against yeast contaminants like those which form cell clusters.

  11. Yeast Population Dynamics in Spontaneous and Inoculated Alcoholic Fermentations of Zametovka Must

    Directory of Open Access Journals (Sweden)

    Franc Cus

    2002-01-01

    Full Text Available Inoculated fermentations, which are more rapid and more reliable than spontaneous fermentations, and assure predictable wine quality, are nowadays prevalent in Slovenia’s large-scale wine production. However, spontaneous fermentation strengthens local characteristics of wine and offers opportunities for technological innovation. In the 1999 vintage, spontaneous and inoculated fermentations of Zametovka (Vitis vinifera grape must were studied. Zametovka is the main red variety in production of traditional Slovene red blend wine, Cvicek. The diversity of yeast species and strains in both of the investigated fermentations was determined by molecular and traditional identification methods. The outset of alcoholic fermentation, yeast growth kinetics, and yeast population dynamics presents the main differences between the examined fermentations. Yeast population diversity was higher in the spontaneous process. Dominant yeast isolates from spontaneous fermentation were identified as Candida stellata, Hanseniaspora uvarum and Saccharomyces cerevisiae; whereas Saccharomyces bayanus, Pichia kluyveri, Pichia membranifaciens and Torulaspora delbrueckiim were found less frequently. Dominant species in the inoculated fermentation was Saccharomyces cerevisiae; other species found in smaller numbers were Candida stellata, Hanseniaspora uvarum and Debaryomyces hansenii var. hansenii. Using PFGE, we were able to distinguish among 15 different Saccharomyces cerevisiae strains and three different Saccharomyces bayanus strains isolated from spontaneous fermentation, whereas, in the case of inoculated fermentation, only two Saccharomyces cerevisiae strains were found. Their chromosomal patterns coincide with the chromosomal patterns of the starter culture strains.

  12. Probiotic Lactobacillus reuteri has antifungal effects on oral Candida species in vitro.

    Science.gov (United States)

    Jørgensen, Mette Rose; Kragelund, Camilla; Jensen, Peter Østrup; Keller, Mette Kirstine; Twetman, Svante

    2017-01-01

    Background: An alternative approach for managing Candida infections in the oral cavity by modulating the oral microbiota with probiotic bacteria has been proposed. Objective: The aim was to investigate the antifungal potential of the probiotic bacterium Lactobacillus reuteri (DSM 17938 and ATCC PTA 5289) against six oral Candida species ( C. albicans, C. glabrata, C. krusei, C. tropicalis, C. dubliniensis , and C. parapsilosis ). Design: The lactobacilli were tested for their ability to co-aggregate with and inhibit the growth of the yeasts assessed by spectrophotometry and the agar overlay inhibition assay. Additionally, the pH was evaluated with microsensors, and the production of hydrogen peroxide (H2O2) by the lactobacilli was verified. Results: Both L. reuteri strains showed co-aggregation abilities with the yeasts. The lactobacilli almost completely inhibited the growth of C. albicans and C. parapsilosis , but did not affect C. krusei . Statistically significant differences in co-aggregation and growth inhibition capacities between the two L. reuteri strains were observed (preuteri exhibited antifungal properties against five of the six most common oral Candida species. Further, the results reconfirms that the probiotic capacity of L. reuteri is strain specific.

  13. Yeast diversity isolated from grape musts during spontaneous fermentation from a Brazilian winery.

    Science.gov (United States)

    Bezerra-Bussoli, Carolina; Baffi, Milla Alves; Gomes, Eleni; Da-Silva, Roberto

    2013-09-01

    Saccharomyces and non-Saccharomyces yeast species from a winery located in Brazil were identified by ribosomal gene-sequencing analysis. A total of 130 yeast strains were isolated from grape surfaces and musts during alcoholic fermentation from Isabel, Bordeaux, and Cabernet Sauvignon varieties. Samples were submitted to PCR-RFLP analysis and genomic sequencing. Thirteen species were identified: Candida quercitrusa, Candida stellata, Cryptococcus flavescens, Cryptococcus laurentii, Hanseniaspora uvarum, Issatchenkia occidentalis, Issatchenkia orientalis, Issatchenkia terricola, Pichia kluyveri, Pichia guilliermondii, Pichia sp., Saccharomyces cerevisiae, and Sporidiobolus pararoseus. A sequential substitution of species during the different stages of fermentation, with a dominance of non-Saccharomyces yeasts at the beginning, and a successive replacement of species by S. cerevisiae strains at the final steps were observed. This is the first report about the yeast distribution present throughout the alcoholic fermentation in a Brazilian winery, providing supportive information for future studies on their contribution to wine quality.

  14. Oxygen availability and strain combination modulate yeast growth dynamics in mixed culture fermentations of grape must with Starmerella bacillaris and Saccharomyces cerevisiae.

    Science.gov (United States)

    Englezos, Vasileios; Cravero, Francesco; Torchio, Fabrizio; Rantsiou, Kalliopi; Ortiz-Julien, Anne; Lambri, Milena; Gerbi, Vincenzo; Rolle, Luca; Cocolin, Luca

    2018-02-01

    Starmerella bacillaris (synonym Candida zemplinina) is a non-Saccharomyces yeast that has been proposed as a co-inoculant of selected Saccharomyces cerevisiae strains in mixed culture fermentations to enhance the analytical composition of the wines. In order to acquire further knowledge on the metabolic interactions between these two species, in this study we investigated the impact of oxygen addition and combination of Starm. bacillaris with S. cerevisiae strains on the microbial growth and metabolite production. Fermentations were carried out under two different conditions of oxygen availability. Oxygen availability and strain combination clearly influenced the population dynamics throughout the fermentation. Oxygen concentration increased the survival time of Starm. bacillaris and decreased the growth rate of S. cerevisiae strains in mixed culture fermentations, whereas it did not affect the growth of the latter in pure culture fermentations. This study reveals new knowledge about the influence of oxygen availability on the successional evolution of yeast species during wine fermentation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Five novel Wickerhamomyces- and Metschnikowia-related yeast species, Wickerhamomyces chaumierensis sp. nov., Candida pseudoflosculorum sp. nov., Candida danieliae sp. nov., Candida robnettiae sp. nov. and Candida eppingiae sp. nov., isolated from plants

    NARCIS (Netherlands)

    Groenewald, Marizeth; Robert, Vincent; Smith, Maudy Th

    On the basis of nucleotide divergences in the D1/D2 domain of the 26S rRNA gene and the internal transcribed spacers (ITS) domain of the rRNA gene, five novel yeast species, Wickerhamomyces chaumierensis sp. nov. (CBS 8565(T)  = JCM 17246(T)), Candida pseudoflosculorum sp. nov. (CBS 8584(T)  = JCM

  16. Deoxyribonucleic acid-deficient strains of Candida albicans.

    OpenAIRE

    Olaiya, A F; Steed, J R; Sogin, S J

    1980-01-01

    We analyzed a series of germ tube-negative variants isolated from Candida albicans 3153A for deoxyribonucleic acid content. As analyzed by flow microfluorometry, the deoxyribonucleic acid level in these variant strains was 50% of that of the parental strain and equivalent to that of haploid Saccharomyces cerevisiae. This finding was confirmed by comparison of survival rates when exposed to the mutagens ultraviolet light, ethyl methane sulfonate, and methyl methane sulfonate. The diameter of t...

  17. Identification of salivary components that induce transition of hyphae to yeast in Candida albicans

    NARCIS (Netherlands)

    Leito, J.T.D.; Ligtenberg, A.J.M.; Nazmi, K.; Veerman, E.C.I.

    2009-01-01

    Candida albicans, the major human fungal pathogen, undergoes a reversible morphological transition from single yeast cells to pseudohyphae and hyphae filaments. The hyphae form is considered the most invasive form of the fungus. The purpose of this study is to investigate the effect of saliva on

  18. Adding Flavor to Beverages with Non-Conventional Yeasts

    Directory of Open Access Journals (Sweden)

    Davide Ravasio

    2018-02-01

    Full Text Available Fungi produce a variety of volatile organic compounds (VOCs during their primary and secondary metabolism. In the beverage industry, these volatiles contribute to the the flavor and aroma profile of the final products. We evaluated the fermentation ability and aroma profiles of non-conventional yeasts that have been associated with various food sources. A total of 60 strains were analyzed with regard to their fermentation and flavor profile. Species belonging to the genera Candida, Pichia and Wickerhamomyces separated best from lager yeast strains according to a principal component analysis taking alcohol and ester production into account. The speed of fermentation and sugar utilization were analysed for these strains. Volatile aroma-compound formation was assayed via gas chromatography. Several strains produced substantially higher amounts of aroma alcohols and esters compared to the lager yeast strain Weihenstephan 34/70. Consequently, co-fermentation of this lager yeast strain with a Wickerhamomyces anomalus strain generated an increased fruity-flavour profile. This demonstrates that mixed fermentations utilizing non-Saccharomyces cerevisiae biodiversity can enhance the flavour profiles of fermented beverages.

  19. Isolation and molecular genetic characterization of a yeast strain ...

    African Journals Online (AJOL)

    The yeast was identified by molecular genetics technique based on sequence analysis of the variable D1/D2 domain of the large subunit (26S) ribosomal DNA. Subsequent 26S rRNA gene sequencing showed 100% base sequence homology and it was identified as Candida viswanathii. The degradation of PAHs

  20. Differentiating pneumocystis cysts from Candida Sp. yeasts in pulmonary specimens using methenamine silver

    International Nuclear Information System (INIS)

    Chantiziantoniou, N.

    1996-01-01

    Pneumocystis carinii (PC) pneumonia in the immunocompromised patient requires therapeutic intervention; therefore, rapid identification of PC organisms in cytopathologic specimens is essential. Conclusive diagnoses of PC are achievable using Grocott's methenamine silver (GMS), the gold standard stain for PC cyst visualization. However, non-budding Candida sp. yeasts can stimulate PC cysts with GMS and thus pose significant diagnostic challenges. After qualitative and semi-quantitative analysis of 49 cytopulmonary cases, this study aimed to establish morphologic criteria that differentiate these organisms using GMS. The results showed that spherical/demilune PC cysts (4 to 7 microns in diameter) are monomorphic and mainly transparent, with intracyst densities being commonly evident. Demilune cysts typically display wall wrinkling with longitudinal clefts. Relative to cysts, Candida sp. yeasts reveal increased argyrophilia, range 4 to 10 microns in diameter, are mainly oval and budding, polymorphic and exhibit wall deformation with variable internal structure. Differentiating criteria are (a) budding; (b) cyst transparency, demilune shape; (c) longitudinal cyst clefts; (d) paired common-alike intracyst densities; (e) cyst monomprphism; (f) alveolar cast formations; (g) overall cystomorphologic presentation; and (h)relative argyrophilia. (author)

  1. Yeast communities in Sphagnum phyllosphere along the temperature-moisture ecocline in the boreal forest-swamp ecosystem and description of Candida sphagnicola sp. nov.

    Science.gov (United States)

    Kachalkin, Aleksey V; Yurkov, Andrey M

    2012-06-01

    The effects of the temperature-moisture factors on the phylloplane yeast communities inhabiting Sphagnum mosses were studied along the transition from a boreal forest to a swamp biotope at the Central Forest State Biosphere Reserve (Tver region, Russia). We tested the hypothesis that microclimatic parameters affect yeast community composition and structure even on a rather small spatial scale. Using a conventional plating technique we isolated and identified by molecular methods a total of 15 species of yeasts. Total yeast counts and species richness values did not depend on environmental factors, although yeast community composition and structure did. On average, Sphagnum in the swamp biotope supported a more evenly structured yeast community. Relative abundance of ascomycetous yeasts was significantly higher on swamp moss. Rhodotorula mucilaginosa dominated in the spruce forest and Cryptococcus magnus was more abundant in the swamp. Our study confirmed the low occurrence of tremellaceous yeasts in the Sphagnum phyllosphere. Of the few isolated ascomycetous yeast and yeast-like species, some were differentiated from hitherto known species in physiological tests and phylogenetic analyses. We describe one of them as Candida sphagnicola and designate KBP Y-3887(T) (=CBS 11774(T) = VKPM Y-3566(T) = MUCL 53590(T)) as the type strain. The new species was registered in MycoBank under MB 563443.

  2. Candida ethanolica n. sp.

    Science.gov (United States)

    Rybárová, J; Stros, F; Kocková-Kratochvílová, A

    1980-01-01

    A new yeast, Candida ethanolica, isolated from industrial fodder yeast cultivated on synthetic ethanol as the only source of carbon, originally designated III-5 and III-6, is described. This species differs from all recently accepted Candida species in not assimilating nitrate, not producing urease and not fermenting sugars.

  3. Distribution of dimorphic yeast species in commercial extra virgin olive oil.

    Science.gov (United States)

    Zullo, B A; Cioccia, G; Ciafardini, G

    2010-12-01

    Recent microbiological research has demonstrated the presence of a rich microflora mainly composed of yeasts in the suspended fraction of freshly produced olive oil. Some of the yeasts are considered useful as they improve the organoleptic characteristics of the oil during preservation, whereas others are considered harmful as they can damage the quality of the oil through the hydrolysis of the triglycerides. However, some dimorphic species can also be found among the unwanted yeasts present in the oil, considered to be opportunistic pathogens to man as they have often been isolated from immunocompromised hospital patients. Present research demonstrates the presence of dimorphic yeast forms in 26% of the commercial extra virgin olive oil originating from different geographical areas, where the dimorphic yeasts are represented by 3-99.5% of the total yeasts. The classified isolates belonged to the opportunistic pathogen species Candida parapsilosis and Candida guilliermondii, while among the dimorphic yeasts considered not pathogenic to man, the Candida diddensiae species was highlighted for the first time in olive oil. The majority of the studied yeast strains resulted lipase positive, and can consequently negatively influence the oil quality through the hydrolysis of the triglycerides. Furthermore, all the strains showed a high level of affinity with some organic solvents and a differing production of biofilm in "vitro" corresponded to a greater or lesser hydrophobia of their cells. Laboratory trials indicated that the dimorphic yeasts studied are sensitive towards some components of the oil among which oleic acid, linoleic acid and triolein, whereas a less inhibiting effect was observed with tricaprilin or when the total polyphenols extracted from the oil were used. The observations carried out on a scanning electron microscope (SEM), demonstrated the production of long un-branched pseudohyphae in all the tested dimorphic yeasts when cultivated on nutrient

  4. ISOLATION OF THE CANDIDA TROPICALIS GENE FOR P450 LANOSTEROL DEMETHYLASE AND ITS EXPRESSION IN SACCAROMYCES CEREVISIAE

    Science.gov (United States)

    We have isolated the gene for cytochrome P450 lanosterol 14-demethylase (14DM) from the yeast Candida tropicalis. This was accomplished by screening genomic libraries of strain ATCC750 in E. coli using a DNA fragment containing the yeast Saccharomyces cerevisiae 14DM gene. Identi...

  5. Triacetic acid lactone production in industrial Saccharomyces yeast strains

    Science.gov (United States)

    Triacetic acid lactone (TAL) is a potential platform chemical that can be produced in yeast. To evaluate the potential for industrial yeast strains to produce TAL, the g2ps1 gene encoding 2-pyrone synthase was transformed into thirteen industrial yeast strains of varied genetic background. TAL produ...

  6. Differentiation of enzymatic activity of yeasts and yeast-like microorganisms isolated from various environments

    Directory of Open Access Journals (Sweden)

    Elżbieta Bogusławska-Wąs

    2014-08-01

    Full Text Available The aim of study was to determinate enzymatic activity of yeast-like organisms - Candida lipolytica, Rhodotorula rubra, Trichosporon beigelii, Zygosaccharomyces sp. - isolated from the Szczecin Lagoon and herring salads. We have shown that lipolytic activity was higher than protcolytic for every strain tested. The lowest activity level was found out for amylolytic hydrolases. The results also demonstrated that yeast-like organisms isolated from the Szczecin Lagoon revealed much higher average enzymatic activity compared to tbe same species isolated from herring salads, excepting C. lipolytica.

  7. Identification of Candida species isolated from vulvovaginitis in Mashhad, Iran by Use of MALDI-TOF MS

    Directory of Open Access Journals (Sweden)

    Majid Alizadeh

    2017-12-01

     Of the 65 isolates analyzed, 61 (93.8% were recognised by MALDI-TOF mass spectrometry and for four isolates (6.1% only not relabile identifications were achieved. In this study, the most frequently isolated species were Candida albicans (58.5%, followed by Candida tropicalis (16.9%, Candida glabrata (7.7%, Candida parapsilosis (7.7% and Candida guillermondii (3.1%.  Conclusion presented results demonstrate that the MALDI TOF mass spectrometry is a fast and reliable technique, and has the potential to replace conventional phenotypic identification of Candida species and other yeast strains routinely isolated in clinical microbiology laboratories.

  8. The environmental and intrinsic yeast diversity of Cuban cocoa bean heap fermentations.

    Science.gov (United States)

    Fernández Maura, Yurelkys; Balzarini, Tom; Clapé Borges, Pablo; Evrard, Pierre; De Vuyst, Luc; Daniel, H-M

    2016-09-16

    The environmental yeast diversity of spontaneous cocoa bean fermentations in east Cuba was investigated. Seven fermentations, 25 equipment- and handling-related samples, and 115 environmental samples, such as flowers, leaf and cocoa pod surfaces, as well as drosophilid insects, were analysed. The basic fermentation parameters temperature and pH were recorded during five fermentations for at least six days. A total of 435 yeast isolates were identified by a combination of PCR-fingerprinting of genomic DNA with the M13 primer and sequence analysis of DNA from representative isolates, using the internal transcribed spacer region, the D1/D2 region of the large subunit rRNA gene, and an actin gene-encoding fragment, as required. Among 65 yeast species detected, Pichia manshurica and Hanseniaspora opuntiae were the most frequently isolated species, obtained from five and four fermentations, followed in frequency by Pichia kudriavzevii from two fermentations. Saccharomyces cerevisiae was isolated only occasionally. Cocoa fermentation yeast species were also present on processing equipment. The repeated isolation of a preliminarily as Yamadazyma sp. classified species, a group of strains similar to Saccharomycopsis crataegensis from fermentations and equipment, and the isolation of fifteen other potentially novel yeast species in low numbers provides material for further studies. Environmental samples showed higher yeast diversity compared to the fermentations, included the most frequent fermentation species, whereas the most frequently isolated environmental species were Candida carpophila, Candida conglobata, and Candida quercitrusa. Potential selective advantages of the most frequently isolated species were only partly explained by the physiological traits tested. For instance, tolerance to higher ethanol concentrations was more frequent in strains of Pichia spp. and S. cerevisiae compared to Hanseniaspora spp.; the ability to also assimilate ethanol might have

  9. [INVESTIGATION ON ANTIFUNGAL SUSCEPTIBILITY OF CANDIDA YEASTS IN PREGNANT PATIENTS WITH CONFIRMED VULVOVAGINAL CANDIDIASIS AND THEIR NEWBORNS.

    Science.gov (United States)

    Chokoeva, A; Kouzmanov, A; Ivanova, Z; Zisova, L; Amalie, G; Petleshkova, P; Miteva-Katrandzhieva, Ts; Krasteva, M; Uchikova, E

    Background Vulvovaginal candidiasis (VVU) is considered as a special risk factor during pregnancy, with important influence on the reproductive function of the patients and on the morbidity in the newborns from mothers with VVC. Maternal VVC is a major risk factor for the development of candida-colonization of the infant, which in turn is the first step towards the development of mucocutaneous or systemic candidiasis and Candida-septicemia in the newborn. In pregnant patients, the possible applicable local and systemic medications are limited, while the therapeutic resistance in chronic recurrent forms of VVC increases, facts that require precision of the diagnosic approach to optimize the therapeutic recommendations in pregnant patients, considered as a high risk group. The aim of this study was to investigate in vitro antifungal susceptibility of Candida yeasts to current antifungal agents in pregnant patients with confirmed VVC before the act of birth. Material and Methods Vaginal secretions of 23 healthy pregnant women with proven Candida vaginitis were taken within 48 hours before birth and the presence of yeasls of Candida was confirmed by culture examination. Between 47-72 hours after birth, samples were taken for Candida colonization of the oralmucosa and feces of their newborns. Samples were plated on Sabouraud agar and cultured in an incubator for 2 to 3 days at a temperature of 25° C. Species identification of the isolated yeasts were performed by commercial API Candida test - API 20C AUX (BioMerieux, Marcy-l'Etoile, France). Part of the isolates was identified by commercial whale AUXACOLOR (BioRad, Mames la Coquette, France). Antifungal sensitivity of isolated strains was examined by applying commercial solicitation ready kit and methods of disc diffusion and E-test, as the aim of the authors was to assess their potential for use in the diagnosis, and the correlation between them. Results Candida albicans was the prevalent etiological agent in pregnant

  10. In situ rheology of yeast biofilms.

    Science.gov (United States)

    Brugnoni, Lorena I; Tarifa, María C; Lozano, Jorge E; Genovese, Diego

    2014-01-01

    The aim of the present work was to investigate the in situ rheological behavior of yeast biofilms growing on stainless steel under static and turbulent flow. The species used (Rhodototula mucilaginosa, Candida krusei, Candida kefyr and Candida tropicalis) were isolated from a clarified apple juice industry. The flow conditions impacted biofilm composition over time, with a predominance of C. krusei under static and turbulent flow. Likewise, structural variations occurred, with a tighter appearance under dynamic flow. Under turbulent flow there was an increase of 112 μm in biofilm thickness at 11 weeks (p < 0.001) and cell morphology was governed by hyphal structures and rounded cells. Using the in situ growth method introduced here, yeast biofilms were determined to be viscoelastic materials with a predominantly solid-like behavior, and neither this nor the G'0 values were significantly affected by the flow conditions or the growth time, and at large deformations their weak structure collapsed beyond a critical strain of about 1.5-5%. The present work could represent a starting point for developing in situ measurements of yeast rheology and contribute to a thin body of knowledge about fungal biofilm formation.

  11. Etest and Sensititre YeastOne Susceptibility Testing of Echinocandins against Candida Species from a Single Center in Austria.

    Science.gov (United States)

    Aigner, Maria; Erbeznik, Thomas; Gschwentner, Martin; Lass-Flörl, Cornelia

    2017-08-01

    Candida species were tested for susceptibility to caspofungin, anidulafungin, and micafungin in order to evaluate the roles of Etest and Sensititre YeastOne in antifungal susceptibility testing for daily routines and to survey resistance. A total of 104 Candida species isolates detected from blood cultures were investigated. With EUCAST broth microdilution as the reference method, essential agreement (EA), categorical agreement (CA), very major errors (VME), major errors (ME), and minor (MIN) errors were assessed by reading MICs at 18, 24, and 48 h. By use of EUCAST broth microdilution and species-specific clinical breakpoints (CBPs), echinocandin resistance was not detected during the study period. Using EUCAST CBPs, MIC readings at 24 h for the Etest and Sensititre YeastOne resulted in CA levels of 99% and 93% for anidulafungin and 99% and 97% for micafungin. Using revised CLSI CBPs for caspofungin, CA levels were 92% and 99% for Etest and Sensititre YeastOne. The Etest proved an excellent, easy-to-handle alternative method for testing susceptibility to anidulafungin and micafungin. Due to misclassifications, the Etest is less suitable for testing susceptibility to caspofungin (8% of isolates falsely tested resistant). The CA levels of Sensititre YeastOne were 93% and 97% for anidulafungin and micafungin (24 h) by use of EUCAST CBPs and increased to 100% for both antifungals if CLSI CBPs were applied and to 100% and 99% if Sensititre YeastOne epidemiological cutoff values (ECOFFs) were applied. No one echinocandin could be demonstrated to be superior to another in vitro Since resistance was lacking among our Candida isolates, we cannot derive any recommendation from accurate resistance detection by the Etest and Sensititre YeastOne. Copyright © 2017 American Society for Microbiology.

  12. Adhesion to silicone rubber of yeasts and bacteria isolated from voice prostheses : Influence of salivary conditioning films

    NARCIS (Netherlands)

    Busscher, HJ; GeertsemaDoornbusch, GI; vanderMei, HC

    Adhesion of yeasts and bacteria to silicone rubber is one of the first steps in the biodeterioration of silicone rubber voice prostheses. In this paper, adhesion of two streptococcal, staphylococcal, Candida albicans and Candida tropicalis strains, isolated from explanted voice prostheses was

  13. Repair of 313-nm induced lesions and photoprotection in yeast Candida guilliermondii

    International Nuclear Information System (INIS)

    Fraikin, G.Y.; Pospelov, M.E.; Rubin, L.B.

    1977-01-01

    The present communication is concerned with the effects of near-UV radiation (300-380 nm) on yeast Candida guilliermondii. It was found that certain doses of 313 nm irradiation caused inactivation of the yeast which was exhibited in a way different from the lethal action of far-UV radiation. It was also found that the cells inactivated by 313 nm are capable of recovering vitality, if incubated for some time in a non-nutrient medium. The yeast inactivated by far-UV radiation also proved to be capable of recovering, though to a lesser degree. Both 334 nm radiation and non-lethal doses at 313 nm induced the photoprotective effect against far-UV damage. The effect was exhibited if there was a certain time interval (2-4 h) between the exposures to photoprotective light and subsequent far-UV radiation. Within this time interval the extent of photoprotection was dependent on temperature. (author)

  14. Deoxyribonucleic acid-deficient strains of Candida albicans.

    Science.gov (United States)

    Olaiya, A F; Steed, J R; Sogin, S J

    1980-03-01

    We analyzed a series of germ tube-negative variants isolated from Candida albicans 3153A for deoxyribonucleic acid content. As analyzed by flow microfluorometry, the deoxyribonucleic acid level in these variant strains was 50% of that of the parental strain and equivalent to that of haploid Saccharomyces cerevisiae. This finding was confirmed by comparison of survival rates when exposed to the mutagens ultraviolet light, ethyl methane sulfonate, and methyl methane sulfonate. The diameter of the variant cells as compared to the diameter of the parental 3153A strain showed a relationship similar to that of the diameters of haploid versus diploid S. cerevisiae. These results indicate that those strains may be representative of the imperfect stage of C. albicans.

  15. Characterization of the newly isolated ω-oxidizing yeast Candida sorbophila DS02 and its potential applications in long-chain dicarboxylic acid production.

    Science.gov (United States)

    Lee, Heeseok; Sugiharto, Yohanes Eko Chandra; Lee, Seunghoon; Park, Gyuyeon; Han, Changpyo; Jang, Hyeran; Jeon, Wooyoung; Park, Heejoon; Ahn, Jungoh; Kang, Kyungbo; Lee, Hongwoen

    2017-08-01

    α, ω-Dicarboxylic acids (DCAs) are multipurpose chemicals widely used in polymers, perfumes, plasticizers, lubricants, and adhesives. The biotransformation of DCAs from alkanes and fatty acids by microorganisms has attracted recent interest, since synthesis via chemical oxidation causes problems in terms of the environment and safety. We isolated an ω-oxidizing yeast from a wastewater disposal facility of a petrochemical factory by chemostat enrichment culture. The haploid strain identified as Candida sorbophila DS02 grew on glucose and dodecane, exhibiting greater cell shrinkage on the latter. In flask cultures with mixed alkanes (C10-16) and fatty acid methyl esters (C10-16), DS02 used mixed alkanes simultaneously unlike Candida tropicalis and Yarrowia lipolytica and showed high substrate resistance. In flask cultures with acrylic acid-a known inhibitor of β-oxidation-DS02 produced 0.28 g/l dodecanedioic acid (DDDA) from dodecane, similar to wild-type C. tropicalis ATCC 20336. In fed-batch fermentation, DS02 produced 9.87 g/l DDDA, which was 5.7-fold higher than wild-type C. tropicalis. These results suggest that C. sorbophila strain DS02 has potential applications for the large-scale production of DCA.

  16. Activity of the aqueous extract of Schinus terebinthifolius Raddi on strains of the Candida genus.

    Science.gov (United States)

    Torres, Kátia Andrea de Menezes; Lima, Sônia Maria Rolim Rosa; Ueda, Suely Mitoi Ykko

    2016-12-01

    Objectives  To evaluate the antifungal susceptibility profile of the aqueous extract of the bark of Schinus terebinthifolius Raddi against the strains of the genus Candida . Methods  By using the disk diffusion method, 50 samples of the genus Candida ( Candida albicans ; Candida krusei ; Candida glabrata ; and Candida tropicalis ), isolated from patients receiving treatment at Hospital Santa Casa de Misericórdia de São Paulo, and 1 American Type Culture Collection (ATCC) sample of each species were tested against: the isolated aqueous extract of the bark of Schinus terebinthifolius Raddi, isolated nystatin, and the association of nystatin and the aqueous extract of Schinus terebinthifolius Raddi. Results  There were no significant differences regarding the different strains of Candida tested. In the presence of the aqueous extract of Schinus terebinthifolius Raddi, no inhibition halo was visible. Isolated nystatin formed an inhibition halo measuring respectively 18.50 mm and 19.50 mm for the Candida albicans species and the others referred to as non- Candida albicans ( Candida krusei ; Candida glabrata ; and Candida tropicalis ). The association of nystatin and the aqueous extract of Schinus terebinthifolius Raddi resulted in inhibition halos measuring 14.25 mm and 16.50 mm respectively. The comparisons of these results are statistically significant ( p  Schinus terebinthifolius Raddi showed no antifungal activity in vitro against the strains tested, whereas the association of nystatin and the aqueous extract of Schinus terebinthifolius Raddi caused a decrease in the inhibition halo when compared with isolated nystatin. Thieme-Revinter Publicações Ltda Rio de Janeiro, Brazil.

  17. Cultivating yeast in fractions of light oil from black coal resin. [Candida tropicalis

    Energy Technology Data Exchange (ETDEWEB)

    Kucher, R.V.; Pavlyuk, M.I.; Dzumedzei, N.V.; Turovskii, A.A.

    1982-11-01

    Feasibility of using a light fraction of black coal oil from the Avdeevskii coking plant as a substrate for growing microorganisms was studied. Candida tropicalis was adapted to the light oil in multiple stages and in continually changing conditions. Maximum growth of the yeast occurred in fractions of the oil with boiling points of 363, 373-293 K. It was demonstrated that low temperature fractions of the hard coal oil are a source of hydrocarbons and energy in microbiological processes. Surface-active materials, such as sodium lauryl sulfate and syntanol-15, stimulate the growth of the yeast in light oil fractions from hard coal resin. (5 refs.) (In Russian)

  18. Xylitol production by Debaryomyces hansenii and Candida guilliermondii from rapeseed straw hemicellulosic hydrolysate

    DEFF Research Database (Denmark)

    López-Linares, Juan Carlos; Romero, Inmaculada; Cara, Cristobal

    2018-01-01

    This study evaluated the possibility of using rapeseed straw hemicellulosic hydrolysate as a fermentation medium for xylitol production. Two yeast strains, namely Debaryomyces hansenii and Candida guilliermondii, were used for this bioconversion process and their performance to convert xylose...

  19. Influence of probiotics on Candida presence and IgA anti-Candida in the oral cavity

    Directory of Open Access Journals (Sweden)

    Agda Lima dos Santos

    2009-12-01

    Full Text Available Probiotics are defined as microorganisms that promote benefits to host health, mainly by regulating resident microbiota. Disequilibrium in microbiota can favor the growth of opportunist microorganisms and the development of pathologies, like candidosis caused by yeasts of the Candida genus. This work evaluated whether probiotics consumption was able to influence a specific immunological response to Candida and the presence of these yeasts in the oral cavity. Saliva samples were collected from healthy individuals and plated in Dextrose Saboraud Agar with chloramphenicol. Individuals presenting Candida in the oral cavity used the probiotic Yakult LBâ for 20 days, after which new collections and identifications were performed. Anti-Candida IgA analysis was conducted using the ELISA technique. Analysis of the results showed a significant reduction in Candida prevalence (46% and mean Candida CFU/mL counts (65%. The Candida species identified were C. albicans (98% and C.tropicalis (2%, before and after probiotics consumption. Immunological analysis demonstrated a significant reduction in anti-Candida IgA levels after probiotics use, probably due to less antigenic stimulation. In conclusion, in the individuals studied, probiotics use significantly reduced the amount of Candida in the oral cavity, possibly due to competition between the yeasts rather than by specific secretory immune response stimulation.

  20. Potential application of Candida melibiosica in biofuel cells.

    Science.gov (United States)

    Hubenova, Yolina; Mitov, Mario

    2010-04-01

    Various prokaryote species have been widely studied for microbial fuel cell (MFC) application. However, the information about yeast utilization into biofuel cells is still scanty. The aim of this investigation is to verify if Candida melibiosica 2491, a yeast strain, possessing high phytase activity, could be applied as a biocatalyst in a yeast biofuel cell. The microbiological requirements were coupled with the electrochemical ones tracing main biochemical pathway metabolites such as different carbohydrate and inorganic phosphates and their assimilation with time. The obtained results show that from the three carbohydrates investigated - glucose, fructose and sucrose, fructose is the most suitable for the yeast cultivation. The presence of yeast extract and peptone improves the performance into the biofuel cell. The relationship between the yeast cell amount and the biofuel cell characteristics was determined. Analyses showed that electricity was generated by the yeast culture even in the absence of an artificial mediator. The addition of methylene blue at concentrations higher than 0.1 mM improves the current and power density output. The obtained experimental results proved that C. melibiosica 2491 belongs to the electrogenic strains. 2009 Elsevier B.V. All rights reserved.

  1. Interactions between Candida albicans and Candida glabrata in biofilms: Influence of the strain type, culture medium and glucose supplementation.

    Science.gov (United States)

    Hosida, Thayse Yumi; Cavazana, Thamires Priscila; Henriques, Mariana; Pessan, Juliano Pelim; Delbem, Alberto Carlos Botazzo; Monteiro, Douglas Roberto

    2018-04-01

    The relationship among Candida species may be influenced by several factors. Thus, this study evaluated the interactions between Candida albicans and Candida glabrata in biofilms, varying the strain type, culture medium and glucose supplementation. Biofilms were formed for 48 hours in Sabouraud dextrose broth (SDB) or RPMI 1640, supplemented with 0%, 1% or 5% glucose. Each strain of C. albicans was combined with two strains of C. glabrata, generating four biofilm associations, which were quantified by colony-forming units (CFUs), total biomass and metabolic activity. Data were analysed by ANOVA and Tukey's HSD test (α = 0.05). For CFUs, all associations were classified as indifferent for biofilms formed in RPMI 1640, while for SDB the interactions were antagonistic for C. albicans and indifferent for C. glabrata. The association of reference strains resulted in a dual-species biofilm with biomass significantly higher than that observed for each single biofilm developed in SDB. The metabolic activity of dual-species biofilms did not significantly differ from that found for single ones, except for co-culture of the reference strains. Glucose supplementation and culture media had a significant influence on all parameters. In conclusion, the strain type, culture medium and glucose supplementation influenced the interactions between C. albicans and C. glabrata. © 2017 Blackwell Verlag GmbH.

  2. Candida krusei and Candida glabrata reduce the filamentation of Candida albicans by downregulating expression of HWP1 gene.

    Science.gov (United States)

    de Barros, Patrícia Pimentel; Freire, Fernanda; Rossoni, Rodnei Dennis; Junqueira, Juliana Campos; Jorge, Antonio Olavo Cardoso

    2017-07-01

    Pathogenicity of Candida albicans is associated with its capacity switch from yeast-like to hyphal growth. The hyphal form is capable to penetrate the epithelial surfaces and to damage the host tissues. Therefore, many investigations have focused on mechanisms that control the morphological transitions of C. albicans. Recently, certain studies have showed that non-albicans Candida species can reduce the capacity of C. albicans to form biofilms and to develop candidiasis in animal models. Then, the objective of this study was to evaluate the effects of Candida krusei and Candida glabrata on the morphogenesis of C. albicans. Firstly, the capacity of reference and clinical strains of C. albicans in forming hyphae was tested in vitro. After that, the expression of HWP1 (hyphal wall protein 1) gene was determined by quantitative real-time PCR (polymerase chain reaction) assay. For both reference and clinical strains, a significant inhibition of the hyphae formation was observed when C. albicans was incubated in the presence of C. krusei or C. glabrata compared to the control group composed only by C. albicans. In addition, the culture mixed of C. albicans-C. krusei or C. albicans-C. glabrata reduced significantly the expression of HWP1 gene of C. albicans in relation to single cultures of this specie. In both filamentation and gene expression assays, C. krusei showed the higher inhibitory activity on the morphogenesis of C. albicans compared to C. glabrata. C. krusei and C. glabrata are capable to reduce the filamentation of C. albicans and consequently decrease the expression of the HWP1 gene.

  3. Improving industrial yeast strains: exploiting natural and artificial diversity

    Science.gov (United States)

    Steensels, Jan; Snoek, Tim; Meersman, Esther; Nicolino, Martina Picca; Voordeckers, Karin; Verstrepen, Kevin J

    2014-01-01

    Yeasts have been used for thousands of years to make fermented foods and beverages, such as beer, wine, sake, and bread. However, the choice for a particular yeast strain or species for a specific industrial application is often based on historical, rather than scientific grounds. Moreover, new biotechnological yeast applications, such as the production of second-generation biofuels, confront yeast with environments and challenges that differ from those encountered in traditional food fermentations. Together, this implies that there are interesting opportunities to isolate or generate yeast variants that perform better than the currently used strains. Here, we discuss the different strategies of strain selection and improvement available for both conventional and nonconventional yeasts. Exploiting the existing natural diversity and using techniques such as mutagenesis, protoplast fusion, breeding, genome shuffling and directed evolution to generate artificial diversity, or the use of genetic modification strategies to alter traits in a more targeted way, have led to the selection of superior industrial yeasts. Furthermore, recent technological advances allowed the development of high-throughput techniques, such as ‘global transcription machinery engineering’ (gTME), to induce genetic variation, providing a new source of yeast genetic diversity. PMID:24724938

  4. Effects of metal salt catalysts on yeast cell growth in ethanol conversion

    Science.gov (United States)

    Chung-Yun Hse; Yin Lin

    2009-01-01

    The effects of the addition of metal salts and metal salt-catalyzed hydrolyzates on yeast cell growth in ethanol fermentation were investigated. Four yeast strains (Saccharomyces cerevisiae WT1, Saccharomyces cerevisiae MT81, Candida sp. 1779, and Klumaromyces fragilis), four metal salts (CuCl2, FeCl3, AgNO3, and I2), two metal salt-catalyzed hydrolyzates (...

  5. Enhancement of the far-UV lethality in yeast Candida guilliermondii by near-UV post-irradiation

    International Nuclear Information System (INIS)

    Fraikin, G.Y.; Pospelov, M.E.; Rubin, L.B.

    1980-01-01

    In experiments with the non-photoreactivable yeast Candida guilliermondii, radiations at 313, 334 and 365 nm, having no effect on untreated cell populations, produced an 'enhancing' effect on the lethality of 254 nm-pretreated cells. Wavelengths in the visible region of the spectrum did not exhibit a similar effect. (author)

  6. Non-Conventional Yeast Strains Increase the Aroma Complexity of Bread

    Science.gov (United States)

    Rezaei, Mohammad Naser; Steensels, Jan; Courtin, Christophe M.; Verstrepen, Kevin J.

    2016-01-01

    Saccharomyces cerevisiae is routinely used yeast in food fermentations because it combines several key traits, including fermentation efficiency and production of desirable flavors. However, the dominance of S. cerevisiae in industrial fermentations limits the diversity in the aroma profiles of the end products. Hence, there is a growing interest in non-conventional yeast strains that can help generate the diversity and complexity desired in today’s diversified and consumer-driven markets. Here, we selected a set of non-conventional yeast strains to examine their potential for bread fermentation. Here, we tested ten non-conventional yeasts for bread fermentation, including two Saccharomyces species that are not currently used in bread making and 8 non-Saccharomyces strains. The results show that Torulaspora delbrueckii and Saccharomyces bayanus combine satisfactory dough fermentation with an interesting flavor profile. Sensory analysis and HS-SPME-GC-MS analysis confirmed that these strains produce aroma profiles that are very different from that produced by a commercial bakery strain. Moreover, bread produced with these yeasts was preferred by a majority of a trained sensory panel. These results demonstrate the potential of T. delbrueckii and S. bayanus as alternative yeasts for bread dough leavening, and provide a general experimental framework for the evaluation of more yeasts and bacteria. PMID:27776154

  7. Non-Conventional Yeast Strains Increase the Aroma Complexity of Bread.

    Science.gov (United States)

    Aslankoohi, Elham; Herrera-Malaver, Beatriz; Rezaei, Mohammad Naser; Steensels, Jan; Courtin, Christophe M; Verstrepen, Kevin J

    2016-01-01

    Saccharomyces cerevisiae is routinely used yeast in food fermentations because it combines several key traits, including fermentation efficiency and production of desirable flavors. However, the dominance of S. cerevisiae in industrial fermentations limits the diversity in the aroma profiles of the end products. Hence, there is a growing interest in non-conventional yeast strains that can help generate the diversity and complexity desired in today's diversified and consumer-driven markets. Here, we selected a set of non-conventional yeast strains to examine their potential for bread fermentation. Here, we tested ten non-conventional yeasts for bread fermentation, including two Saccharomyces species that are not currently used in bread making and 8 non-Saccharomyces strains. The results show that Torulaspora delbrueckii and Saccharomyces bayanus combine satisfactory dough fermentation with an interesting flavor profile. Sensory analysis and HS-SPME-GC-MS analysis confirmed that these strains produce aroma profiles that are very different from that produced by a commercial bakery strain. Moreover, bread produced with these yeasts was preferred by a majority of a trained sensory panel. These results demonstrate the potential of T. delbrueckii and S. bayanus as alternative yeasts for bread dough leavening, and provide a general experimental framework for the evaluation of more yeasts and bacteria.

  8. Non-Conventional Yeast Strains Increase the Aroma Complexity of Bread.

    Directory of Open Access Journals (Sweden)

    Elham Aslankoohi

    Full Text Available Saccharomyces cerevisiae is routinely used yeast in food fermentations because it combines several key traits, including fermentation efficiency and production of desirable flavors. However, the dominance of S. cerevisiae in industrial fermentations limits the diversity in the aroma profiles of the end products. Hence, there is a growing interest in non-conventional yeast strains that can help generate the diversity and complexity desired in today's diversified and consumer-driven markets. Here, we selected a set of non-conventional yeast strains to examine their potential for bread fermentation. Here, we tested ten non-conventional yeasts for bread fermentation, including two Saccharomyces species that are not currently used in bread making and 8 non-Saccharomyces strains. The results show that Torulaspora delbrueckii and Saccharomyces bayanus combine satisfactory dough fermentation with an interesting flavor profile. Sensory analysis and HS-SPME-GC-MS analysis confirmed that these strains produce aroma profiles that are very different from that produced by a commercial bakery strain. Moreover, bread produced with these yeasts was preferred by a majority of a trained sensory panel. These results demonstrate the potential of T. delbrueckii and S. bayanus as alternative yeasts for bread dough leavening, and provide a general experimental framework for the evaluation of more yeasts and bacteria.

  9. Biodiversity of Yeasts During Plum Wegierka Zwykla Spontaneous Fermentation

    Directory of Open Access Journals (Sweden)

    Tadeusz Tuszynski

    2005-01-01

    Full Text Available The study comprises an analysis of the yeast microbiota that participated in the spontaneous fermentation of crushed Wegierka Zwykla plum fruit, which is the raw material for slivovitz production in the mountain region in the south of Poland. Saccharomyces cerevisiae yeast strains were differentiated by means of the killer sensitivity analysis related to a killer reference panel of 9 well-known killer yeast strains. The first phase of the fermentation was dominated by the representatives of Kloeckera apiculata and Candida pulcherrima species, which reached their maximum concentration (1.4·106 CFU/mL after 48 h of the process. Almost all yeasts isolated during the following days were classified as S. cerevisiae and the killer sensitivity analysis revealed a high population diversity of this species and the presence of 14 different strains that changed quantitatively and qualitatively throughout the fermentation period.

  10. Screening studies of yeasts capable of utilizing petroleum fractions

    Energy Technology Data Exchange (ETDEWEB)

    El-Masry, H.G.; Foda, M.S.

    1979-01-01

    In these studies 23 yeasts cultures belonging to 10 genera of ascosporogenous, ballistosporogenous, and asporogenous yeasts, were screened with respect to their abilities of hydrocarbon utilization in synthetic media. Thus, kerosene, n-hexadecane, and wax distillate were compared as sole carbon sources in 2% final concentration. Kerosene exhibited marked inhibition on the growth of the majority of the strains, whereas active growth was observed with Debaryomyces vanrijii and many species of the genus Candida in media with n-hexadecane or wax distillate as sole source of carbon. In addition, some cultures belonging to the genera Sporobolomyces, Hansenula, Cryptococcus, and Trigonopsis could utilize some of these substrates, but to a lesser extent. Highest yield of cells and protein was obtained with Candida lipolytica NRRL 1094 in n-hexadecane medium, supplied with 0.03% yeast extract and trace element solutions. The results are discussed with respect to the possibilities of using new yeast genera, with special reference to the genus Debaryomyces, in microbial protein production.

  11. Phenotypic evaluation and characterization of 21 industrial Saccharomyces cerevisiae yeast strains.

    Science.gov (United States)

    Kong, In Iok; Turner, Timothy Lee; Kim, Heejin; Kim, Soo Rin; Jin, Yong-Su

    2018-02-01

    Microorganisms have been studied and used extensively to produce value-added fuels and chemicals. Yeasts, specifically Saccharomyces cerevisiae, receive industrial attention because of their well-known ability to ferment glucose and produce ethanol. Thousands of natural or genetically modified S. cerevisiae have been found in industrial environments for various purposes. These industrial strains are isolated from industrial fermentation sites, and they are considered as potential host strains for superior fermentation processes. In many cases, industrial yeast strains have higher thermotolerance, increased resistances towards fermentation inhibitors and increased glucose fermentation rates under anaerobic conditions when compared with laboratory yeast strains. Despite the advantages of industrial strains, they are often not well characterized. Through screening and phenotypic characterization of commercially available industrial yeast strains, industrial fermentation processes requiring specific environmental conditions may be able to select an ideal starting yeast strain to be further engineered. Here, we have characterized and compared 21 industrial S. cerevisiae strains under multiple conditions, including their tolerance to varying pH conditions, resistance to fermentation inhibitors, sporulation efficiency and ability to ferment lignocellulosic sugars. These data may be useful for the selection of a parental strain for specific biotechnological applications of engineered yeast. © FEMS 2018. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Identification and Determination of Drug Resistant of Candida species isolated from Hospital Acquired Infections

    Directory of Open Access Journals (Sweden)

    Kambiz Diba

    2015-01-01

    Full Text Available Background & aim: Currently, the use of antifungal azole group and yeasts resistant to these drugs is increasing. The aim of this study was to isolate and identify the yeasts obtained from candidiasis patients and furthermore determining thier antifungal resistance. Methods: In the present descriptive study, infections samples were collected from 256 patients with suspected nosocomial candidiasis, then direct exam and culture were performed. Yeast colonies were identified using phenotypic methods, polymerase chain reaction method and enzyme digestion. Data were analyzed using Descriptive statistical tests. Results: Of sixty isolated yeast, thirty-seven cases of Candida albicans (61.6%, seven cases of C. krusei and C. glabrata (11.6% each, five cases of C. dubliniensis (8.3% and four cases of C. tropicalis (6.6% were indicated. The study showed that the sensitivity of C. albicans and C. cruise species to amphotericin B was negligible in disk diffusion and very sensitve in microdilution. Conclusion: Inspite of the results of antifungal susceptibility test of strains studied did not show high resistance, but screening for drug-resistant Candida isolates in Candida infection by disk diffusion and microdilution methods for new cases of drug resistance is reasonable.

  13. Development of Industrial Yeast Platform Strains

    DEFF Research Database (Denmark)

    Bergdahl, Basti; Dato, Laura; Förster, Jochen

    2014-01-01

    Most of the current metabolic engineering projects are carried out using laboratory strains as the starting host. Although such strains are easily manipulated genetically, their robustness does not always meet the requirements set by industrial fermentation conditions. In such conditions, the cells...... screening of the 36 industrial and laboratory yeast strains. In addition, progress in the development of molecular biology methods for generating the new strains will be presented....

  14. Stress tolerance and biocontrol performance of the yeast antagonist, Candida diversa, change with morphology transition.

    Science.gov (United States)

    Li, Guangkun; Chi, Mengshan; Chen, Huizhen; Sui, Yuan; Li, Yan; Liu, Yongsheng; Zhang, Xiaojing; Sun, Zhiqiang; Liu, Guoqing; Wang, Qi; Liu, Jia

    2016-02-01

    As an eco-friendly management method, biological control of postharvest diseases, utilizing antagonistic yeasts, is a research topic receiving considerable attention. Detailed knowledge on the biology of yeast antagonists is crucial when considering their potential application and development as biocontrol products. Changes in the growth form, such as single-cell to pseudohyphae, have been associated with the mode of action in postharvest biocontrol yeasts. In this study, the antagonistic yeast, Candida diversa, reversibly shifted from a single-cell morphology on yeast peptone dextrose (YPD) medium with 2 % agar to a pseudohyphal morphology on YPD with 0.3 % agar. The tolerance of the pseudohyphal form to heat and oxidative stresses, as well as the biocontrol efficacy against Botrytis cinerea on apple and kiwifruit stored at 25 and 4 °C, was significantly higher as compared to the single-cell form. This study provides new information on the ability of C. diversa to change its morphology and the impact of the morphology shift on stress tolerance and biocontrol performance.

  15. Improving industrial yeast strains: exploiting natural and artificial diversity.

    Science.gov (United States)

    Steensels, Jan; Snoek, Tim; Meersman, Esther; Picca Nicolino, Martina; Voordeckers, Karin; Verstrepen, Kevin J

    2014-09-01

    Yeasts have been used for thousands of years to make fermented foods and beverages, such as beer, wine, sake, and bread. However, the choice for a particular yeast strain or species for a specific industrial application is often based on historical, rather than scientific grounds. Moreover, new biotechnological yeast applications, such as the production of second-generation biofuels, confront yeast with environments and challenges that differ from those encountered in traditional food fermentations. Together, this implies that there are interesting opportunities to isolate or generate yeast variants that perform better than the currently used strains. Here, we discuss the different strategies of strain selection and improvement available for both conventional and nonconventional yeasts. Exploiting the existing natural diversity and using techniques such as mutagenesis, protoplast fusion, breeding, genome shuffling and directed evolution to generate artificial diversity, or the use of genetic modification strategies to alter traits in a more targeted way, have led to the selection of superior industrial yeasts. Furthermore, recent technological advances allowed the development of high-throughput techniques, such as 'global transcription machinery engineering' (gTME), to induce genetic variation, providing a new source of yeast genetic diversity. © 2014 The Authors. FEMS Microbiology Reviews published by John Wiley & Sons Ltd on behalf of Federation of European Microbiological Societies.

  16. Molecular identification and distribution profile of Candida species isolated from Iranian patients.

    Science.gov (United States)

    Mohammadi, Rasoul; Mirhendi, Hossein; Rezaei-Matehkolaei, Ali; Ghahri, Mohammad; Shidfar, Mohammad Reza; Jalalizand, Nilufar; Makimura, Koichi

    2013-08-01

    A total of 855 yeast strains isolated from different clinical specimens, mainly nail (42%) and vulva-vagina (25%) were identified by a set of polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP). Genomic DNA was extracted from fresh colonies using Whatman FTA Card technology. PCR assays were performed on the complete ribosomal DNA internal transcribed spacer (rDNA-ITS) region for all isolates and species identification was carried out through their specific electrophoretic profiles after digestion with the enzyme MspI. Those isolates suspected as Candida parapsilosis group were then subjected to amplification of the secondary alcohol dehydrogenase (SADH) gene and restriction digestion with NlaIII enzyme. In total, 71.1% of the strains were obtained from females and 28.9% from males. The age group of 31-40 years consisted of the highest frequency of patients with candidiasis. Candida albicans was the predominant species (58.6%) followed by C. parapsilosis (11.0%), C. glabrata (8.3%), C. tropicalis (7.0%), C. kefyr (5.8%), C. krusei (4.4%), C. orthopsilosis (2.1%), and C. guilliermondii (0.6%). A few strains of C. lusitaniae, C. rugosa, C. intermedia, C. inconspicua, C. neoformans and S. cerevisiae were isolated. We could not identify 8 (0.9%) isolates. Candida albicans remains the most frequently species isolated from Iranian patients; however, the number of non-C. albicans Candida species looks to be increasing. The simple and reliable PCR-RFLP system used in the study has the potential to identify most clinically isolated yeasts.

  17. Development and buildup of a biomass by various yeasts on whey

    Energy Technology Data Exchange (ETDEWEB)

    Zalashka, L S; Samtsevich, S A; Bakunowicz, L

    1967-01-01

    Of the 113 strains of yeast grown on whey, 29 assimilated lactose by fermentation and 23 by direct souring. The most productive were Candida humicola and C. curvata. The buildup of biomass averaged 18 to 30 g./1. medium.

  18. Malassezia versus Candida in Healthy Dogs

    Directory of Open Access Journals (Sweden)

    Sihelská Z.

    2017-03-01

    Full Text Available The genera Malassezia and Candida include yeasts which are members of the normal mycobiota of the skin and mucosal sites of humans and other warm-blooded animals. These yeasts are associated with a variety of dermatological disorders and also systemic diseases in humans and other animals. This study confirms the occurrence of Malassezia and Candida species in healthy dogs. Samples were collected from different body sites: external ear canal, interdigital area, skin of the axilla and of the neck, and the oral and rectal mucosae. The isolates were identified using phenotypic methods (biochemical-physiological and morphological characteristics. The presence of yeasts were investigated in the specimens from 70 healthy dogs. Malassezia species were isolated in 44 dogs from which 84 Malassezia isolates were obtained. Only one Candida isolate was obtained from the dogs examined. It was found that Candida does not occur in dogs normally and Malassezia was the main colonizing yeast in healthy dogs.

  19. Global Transcriptome Sequencing Identifies Chlamydospore Specific Markers in Candida albicans and Candida dubliniensis

    LENUS (Irish Health Repository)

    Palige, Katja

    2013-04-15

    Candida albicans and Candida dubliniensis are pathogenic fungi that are highly related but differ in virulence and in some phenotypic traits. During in vitro growth on certain nutrient-poor media, C. albicans and C. dubliniensis are the only yeast species which are able to produce chlamydospores, large thick-walled cells of unknown function. Interestingly, only C. dubliniensis forms pseudohyphae with abundant chlamydospores when grown on Staib medium, while C. albicans grows exclusively as a budding yeast. In order to further our understanding of chlamydospore development and assembly, we compared the global transcriptional profile of both species during growth in liquid Staib medium by RNA sequencing. We also included a C. albicans mutant in our study which lacks the morphogenetic transcriptional repressor Nrg1. This strain, which is characterized by its constitutive pseudohyphal growth, specifically produces masses of chlamydospores in Staib medium, similar to C. dubliniensis. This comparative approach identified a set of putatively chlamydospore-related genes. Two of the homologous C. albicans and C. dubliniensis genes (CSP1 and CSP2) which were most strongly upregulated during chlamydospore development were analysed in more detail. By use of the green fluorescent protein as a reporter, the encoded putative cell wall related proteins were found to exclusively localize to C. albicans and C. dubliniensis chlamydospores. Our findings uncover the first chlamydospore specific markers in Candida species and provide novel insights in the complex morphogenetic development of these important fungal pathogens.

  20. Comparison of the adhesion ability of Candida albicans strains to ...

    African Journals Online (AJOL)

    The purpose of the present study is to investigate the ability of oral Candida albicans strains to adhere to Caco-2 and Hep-2 epithelial cells, to produce slime using Congo red and Safranin methods and to form a biofilm on polymethylmethacrylate. A total of 20 C. albicans strains were tested in the present work. The biofilm ...

  1. Comparative evaluation of six chromogenic media for presumptive yeast identification.

    Science.gov (United States)

    Vecchione, Alessandra; Florio, Walter; Celandroni, Francesco; Barnini, Simona; Lupetti, Antonella; Ghelardi, Emilia

    2017-12-01

    The present study was undertaken to evaluate the discrimination ability of six chromogenic media in presumptive yeast identification. We analysed 108 clinical isolates and reference strains belonging to eight different species: Candida albicans , Candida dubliniensis , Candida tropicalis , Candida krusei , Candida glabrata , Candida parapsilosis , Candida lusitaniae and Trichosporon mucoides . C. albicans , C. tropicalis and C. krusei could be distinguished from one another in all the tested chromogenic media, as predicted by the manufacturers. In addition, C. albicans could be distinguished from C. dubliniensis on BBL CHROMagar Candida, Kima CHROMagar Candida and Brilliance Candida, and C. parapsilosis could be identified on CHROMATIC Candida agar, CHROMOGENIC Candida agar, and Brilliance Candida agar. Brilliance Candida provided the widest discrimination ability, being able to discriminate five out of the seven Candida species tested. Interestingly, C. tropicalis and C. krusei could be already distinguished from each other after 24 hours of incubation. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  2. Hybrid yeast strains capable of raising an extraordinarily broad range of dough types

    Energy Technology Data Exchange (ETDEWEB)

    Kowalski, S.; Zander, I.; Windisch, S.

    1981-01-01

    Over 200 hybrid yeast strains were screened and 11 of these found to have versatile fermentation characteristics. This paper reports the results obtained with these 11 strains compared with a commercially available strain of baker's yeast used for bread making and marketed as 'instant active dry yeast'. In contrast to bakers yeast, the hybrid strains fermented very well in yeast, hard biscuit, shortcake and heavy cake dough without prior sponge formation. The fermentation kinetics were investigated and the technical potential of such hybrid strains discussed on the basis of the fermentation kinetics.

  3. Genomics and Biochemistry of Saccharomyces cerevisiae Wine Yeast Strains.

    Science.gov (United States)

    Eldarov, M A; Kishkovskaia, S A; Tanaschuk, T N; Mardanov, A V

    2016-12-01

    Saccharomyces yeasts have been used for millennia for the production of beer, wine, bread, and other fermented products. Long-term "unconscious" selection and domestication led to the selection of hundreds of strains with desired production traits having significant phenotypic and genetic differences from their wild ancestors. This review summarizes the results of recent research in deciphering the genomes of wine Saccharomyces strains, the use of comparative genomics methods to study the mechanisms of yeast genome evolution under conditions of artificial selection, and the use of genomic and postgenomic approaches to identify the molecular nature of the important characteristics of commercial wine strains of Saccharomyces. Succinctly, data concerning metagenomics of microbial communities of grapes and wine and the dynamics of yeast and bacterial flora in the course of winemaking is provided. A separate section is devoted to an overview of the physiological, genetic, and biochemical features of sherry yeast strains used to produce biologically aged wines. The goal of the review is to convince the reader of the efficacy of new genomic and postgenomic technologies as tools for developing strategies for targeted selection and creation of new strains using "classical" and modern techniques for improving winemaking technology.

  4. Subcellular location of the enzymes of purine breakdown in the yeast Candida famata grown on uric acid

    NARCIS (Netherlands)

    Large, Peter J.; Waterham, Hans R.; Veenhuis, Marten

    1990-01-01

    The subcellular location of the enzymes of purine breakdown in the yeast Candida famata, which grows on uric acid as sole carbon and nitrogen source, has been examined by subcellular fractionation methods. Uricase was confirmed as being peroxisomal, but the other three enzymes, allantoinase,

  5. Determination of antifungal susceptibility patterns among the clinical isolates of Candida species

    Directory of Open Access Journals (Sweden)

    Kamiar Zomorodian

    2011-01-01

    Full Text Available Context: Candida species are opportunistic yeasts that cause infections ranging from simple dermatosis to potentially life-threatening fungemia. The emergence of resistance to antifungal drugs has been increased in the past two decades. Aim: the present study we determined to find out the susceptibility profiles of clinical isolates of Candida species against four antifungal drugs, including amphotericin B, ketoconazole, fluconazole and itraconazole. Materials and Methods: Antifungal susceptibility testing of the yeasts was done in accordance with the proposed guidelines for antifungal disk diffusion susceptibility testing of yeasts based on the CLSI document M44-A. Results: A total of 206 yeast isolates were assessed. Among the evaluated Candida species, the highest rates of resistance to ketoconazole were seen in Candida glabrata (16.6% and Candida albicans (3.2%. Susceptibility and intermediate response to fluconazole were seen in 96.6% and 3.4% of the Candida isolates, respectively. A total of 19 (9.2% yeast isolates showed petite phenomenon including 11 C. glabrata, 3 C. albicans, 2 Candida dubliniensis and one isolate of each Candida krusei and Candida parapsilosis. Conclusion: The high number of petite mutation in the isolated yeasts should be seriously considered since it may be one of the reasons of antifungal treatment failure.

  6. [Yeast microbiota in artisanal cheeses from Corrientes, Argentina].

    Science.gov (United States)

    Cardozo, Marina C; Fusco, Ángel J V; Carrasco, Marta S

    The artisanal cheese from Corrientes (from the Spanish acronym QAC-Queso Artesanal de Corrientes/Artisanal Cheese from Corrientes) is a soft cheese elaborated with raw cow milk and an artisanal coagulant agent. Lactic bacteria contitute the main flora of this cheese although yeasts are also present in high quantities as secondary microbiota and might play a relevant role in cheese ripening. The aim of this work was to evaluate yeast occurrence during QAC elaboration and ripening, and the effect of seasonal variation. Yeasts were isolated and purified from raw materials and cheese at different ripening stagesl elaborated during the different seasons. Yeast sample counts were in the order of 10 3 - 10 7 UFC/ml o UFC/g. Ninety yeast strains were classified: 9 from milk, 28 from the coagulant agent, 10 from curd and 43 from cheese. Candida predominated in milk samples while other yeast genera had low incidence. Candida also predominated in the coagulant agent samples, followed by genera Myxozyma and Debaryomyces. The isolates obtained from cheese belonged to the same genera predominating in the coagulant agent, and showed the same order of prevalence. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  7. Cellulolytic enzyme expression and simultaneous conversion of lignocellulosic sugars into ethanol and xylitol by a new Candida tropicalis strain.

    Science.gov (United States)

    Mattam, Anu Jose; Kuila, Arindam; Suralikerimath, Niranjan; Choudary, Nettem; Rao, Peddy V C; Velankar, Harshad Ravindra

    2016-01-01

    Lignocellulosic ethanol production involves major steps such as thermochemical pretreatment of biomass, enzymatic hydrolysis of pre-treated biomass and the fermentation of released sugars into ethanol. At least two different organisms are conventionally utilized for producing cellulolytic enzymes and for ethanol production through fermentation, whereas in the present study a single yeast isolate with the capacity to simultaneously produce cellulases and xylanases and ferment the released sugars into ethanol and xylitol has been described. A yeast strain isolated from soil samples and identified as Candida tropicalis MTCC 25057 expressed cellulases and xylanases over a wide range of temperatures (32 and 42 °C) and in the presence of different cellulosic substrates [carboxymethylcellulose and wheat straw (WS)]. The studies indicated that the cultivation of yeast at 42 °C in pre-treated hydrolysate containing 0.5 % WS resulted in proportional expression of cellulases (exoglucanases and endoglucanases) at concentrations of 114.1 and 97.8 U g(-1) ds, respectively. A high xylanase activity (689.3 U g(-1) ds) was also exhibited by the yeast under similar growth conditions. Maximum expression of cellulolytic enzymes by the yeast occurred within 24 h of incubation. Of the sugars released from biomass after pretreatment, 49 g L(-1) xylose was aerobically converted into 15.8 g L(-1) of xylitol. In addition, 25.4 g L(-1) glucose released after the enzymatic hydrolysis of biomass was fermented by the same yeast to obtain an ethanol titer of 7.3 g L(-1). During the present study, a new strain of C. tropicalis was isolated and found to have potential for consolidated bioprocessing (CBP) applications. The strain could grow in a wide range of process conditions (temperature, pH) and in the presence of lignocellulosic inhibitors such as furfural, HMF and acetic acid. The new yeast produced cellulolytic enzymes over a wide temperature range and in the presence of

  8. Atividade in vitro de extratos brutos de duas espécies vegetais do cerrado sobre leveduras do gênero Candida In vitro activity of crude extracts of two plant species in the Cerrado on yeast of the Candida SPP variety

    Directory of Open Access Journals (Sweden)

    Sônia Maria Ferreira Queiroz e Silva

    2012-06-01

    Full Text Available Objetivou-se conhecer a atividade de Lafoensia pacari e a de Brossimum gaudichaudii, sobre leveduras do gênero Candida isoladas da mucosa vaginal. As leveduras foram isoladas a partir de esfregaço de mucosa vaginal de mulheres com ou sem sintomatologia. Realizou-se os testes de susceptibilidade em duplicata para 34 linhagens de Candida frente aos extratos brutos das espécies vegetais, nas concentrações de 50, 100 e 200 mg.mL-1. Consideraram-se como ativos os extratos que produziram halos de inibição com média a partir de 10 mm. Evidenciou-se atividade antifúngica de B. gaudichaudii na concentração de 200 mg.mL-1, enquanto que a de L. pacari mostrou-se ativo a 50 mg.mL-1. A atividade dos extratos vegetais estudados destacou-se em relação à Nistatina creme (100.000UI/4g utilizada como controle.This work aims to evaluate the activity of Lafoensia Pacari and Brossimum gaudichaudii on yeast of the Candida variety isolated from vaginal mucus. The yeasts were obtained from swabs of women with or without symptoms. Susceptibility testing in duplicate was carried out for 34 strains of Candida compared to crude extracts of plant species at concentrations of 50, 100 and 200 mg.mL-1. Extracts that produced inhibition zones with an average of over 10 mm were considered to be active. Antifungal activity of B. gaudichaudii at a concentration of 200-mg.mL-1 was proven, while that of L. pacari was found to be active at 50 mg.mL-1. The activity of plant extracts was revealed compared to Nystatin cream (100.000UI/4g used for control purposes.

  9. Application of MALDI-TOF MS for requalification of a Candida clinical isolates culture collection

    Directory of Open Access Journals (Sweden)

    Reginaldo Lima-Neto

    2014-06-01

    Full Text Available Microbial culture collections underpin biotechnology applications and are important resources for clinical microbiology by supplying reference strains and/or performing microbial identifications as a service. Proteomic profiles by MALDI-TOF MS have been used for Candida spp. identification in clinical laboratories and demonstrated to be a fast and reliable technique for the routine identification of pathogenic yeasts. The main aim of this study was to apply MALDI-TOF MS combined with classical phenotypic and molecular approaches to identify Candida clinical isolates preserved from 1 up to 52 years in a Brazilian culture collection and assess its value for the identification of yeasts preserved in this type of collections. Forty Candida spp. clinical isolates were identified by morphological and biochemical analyses. Identifications were also performed by the new proteomic approach based on MALDI-TOF MS. Results demonstrated 15% discordance when compared with morphological and biochemical analyses. Discordant isolates were analysed by ITS sequencing, which confirmed the MALDI-TOF MS identifications and these strains were renamed in the culture collection catalogue. In conclusion, proteomic profiles by MALDI-TOF MS represents a rapid and reliable method for identifying clinical Candida species preserved in culture collections and may present clear benefits when compared with the performance of existing daily routine methods applied at health centres and hospitals.

  10. Quality parameters and RAPD-PCR differentiation of commercial baker's yeast and hybrid strains.

    Science.gov (United States)

    El-Fiky, Zaki A; Hassan, Gamal M; Emam, Ahmed M

    2012-06-01

    Baker's yeast, Saccharomyces cerevisiae, is a key component in bread baking. Total of 12 commercial baker's yeast and 2 hybrid strains were compared using traditional quality parameters. Total of 5 strains with high leavening power and the 2 hybrid strains were selected and evaluated for their alpha-amylase, maltase, glucoamylase enzymes, and compared using random amplified polymorphic DNA (RAPD). The results revealed that all selected yeast strains have a low level of alpha-amylase and a high level of maltase and glucoamylase enzymes. Meanwhile, the Egyptian yeast strain (EY) had the highest content of alpha-amylase and maltase enzymes followed by the hybrid YH strain. The EY and YH strains have the highest content of glucoamylase enzyme almost with the same level. The RAPD banding patterns showed a wide variation among commercial yeast and hybrid strains. The closely related Egyptian yeast strains (EY and AL) demonstrated close similarity of their genotypes. The 2 hybrid strains were clustered to Turkish and European strains in 1 group. The authors conclude that the identification of strains and hybrids using RAPD technique was useful in determining their genetic relationship. These results can be useful not only for the basic research, but also for the quality control in baking factories. © 2012 Institute of Food Technologists®

  11. Brewing characteristics of haploid strains isolated from sake yeast Kyokai No. 7.

    Science.gov (United States)

    Katou, Taku; Kitagaki, Hiroshi; Akao, Takeshi; Shimoi, Hitoshi

    2008-11-01

    Sake yeast exhibit various characteristics that make them more suitable for sake brewing compared to other yeast strains. Since sake yeast strains are Saccharomyces cerevisiae heterothallic diploid strains, it is likely that they have heterozygous alleles on homologous chromosomes (heterozygosity) due to spontaneous mutations. If this is the case, segregation of phenotypic traits in haploid strains after sporulation and concomitant meiosis of sake yeast strains would be expected to occur. To examine this hypothesis, we isolated 100 haploid strains from Kyokai No. 7 (K7), a typical sake yeast strain in Japan, and compared their brewing characteristics in small-scale sake-brewing tests. Analyses of the resultant sake samples showed a smooth and continuous distribution of analytical values for brewing characteristics, suggesting that K7 has multiple heterozygosities that affect brewing characteristics and that these heterozygous alleles do segregate after sporulation. Correlation and principal component analyses suggested that the analytical parameters could be classified into two groups, indicating fermentation ability and sake flavour. (c) 2008 John Wiley & Sons, Ltd.

  12. Modulation of intestinal inflammation by yeasts and cell wall extracts: strain dependence and unexpected anti-inflammatory role of glucan fractions.

    Directory of Open Access Journals (Sweden)

    Samir Jawhara

    Full Text Available Yeasts and their glycan components can have a beneficial or adverse effect on intestinal inflammation. Previous research has shown that the presence of Saccharomyces cerevisiae var. boulardii (Sb reduces intestinal inflammation and colonization by Candida albicans. The aim of this study was to identify dietary yeasts, which have comparable effects to the anti-C. albicans and anti-inflammatory properties of Sb and to assess the capabilities of yeast cell wall components to modulate intestinal inflammation. Mice received a single oral challenge of C. albicans and were then given 1.5% dextran-sulphate-sodium (DSS for 2 weeks followed by a 3-day restitution period. S. cerevisiae strains (Sb, Sc1 to Sc4, as well as mannoprotein (MP and β-glucan crude fractions prepared from Sc2 and highly purified β-glucans prepared from C. albicans were used in this curative model, starting 3 days after C. albicans challenge. Mice were assessed for the clinical, histological and inflammatory responses related to DSS administration. Strain Sc1-1 gave the same level of protection against C. albicans as Sb when assessed by mortality, clinical scores, colonization levels, reduction of TNFα and increase in IL-10 transcription. When Sc1-1 was compared with the other S. cerevisiae strains, the preparation process had a strong influence on biological activity. Interestingly, some S. cerevisiae strains dramatically increased mortality and clinical scores. Strain Sc4 and MP fraction favoured C. albicans colonization and inflammation, whereas β-glucan fraction was protective against both. Surprisingly, purified β-glucans from C. albicans had the same protective effect. Thus, some yeasts appear to be strong modulators of intestinal inflammation. These effects are dependent on the strain, species, preparation process and cell wall fraction. It was striking that β-glucan fractions or pure β-glucans from C. albicans displayed the most potent anti-inflammatory effect in the

  13. Construction and fed-batch cultivation of Candida famata with enhanced riboflavin production.

    Science.gov (United States)

    Dmytruk, Kostyantyn; Lyzak, Oleksy; Yatsyshyn, Valentyna; Kluz, Maciej; Sibirny, Vladimir; Puchalski, Czeslaw; Sibirny, Andriy

    2014-02-20

    Riboflavin (vitamin B2) is an essential nutrition component serving as a precursor of coenzymes FMN and FAD that are involved mostly in reactions of oxidative metabolism. Riboflavin is produced in commercial scale and is used in feed and food industries, and in medicine. The yeast Candida famata (Candida flareri) belongs to the group of so called "flavinogenic yeasts" which overproduce riboflavin under iron limitation. Three genes SEF1, RIB1 and RIB7 coding for a putative transcription factor, GTP cyclohydrolase II and riboflavin synthase, respectively were simultaneously overexpressed in the background of a non-reverting riboflavin producing mutant AF-4, obtained earlier in our laboratory using methods of classical selection (Dmytruk et al. (2011), Metabolic Engineering 13, 82-88). Cultivation conditions of the constructed strain were optimized for shake-flasks and bioreactor cultivations. The constructed strain accumulated up to 16.4g/L of riboflavin in optimized medium in a 7L laboratory bioreactor during fed-batch fermentation. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Isolation of the alkane inducible cytochrome P450 (P450alk) gene from the yeast Candida tropicalis

    Science.gov (United States)

    The gene for the alkane-inducible cytochrome P450, P450alk, has been isolated from the yeast Candida tropicalis by immunoscreening a λgt11 library. Isolation of the gene has been identified on the basis of its inducibility and partial DNA sequence. Transcripts of this gene were i...

  15. Identification of inhibitors of yeast-to-hyphae transition in Candida albicans by a reporter screening assay.

    Science.gov (United States)

    Heintz-Buschart, Anna; Eickhoff, Holger; Hohn, Erwin; Bilitewski, Ursula

    2013-03-10

    Candida albicans is one of the most common opportunistic fungal pathogens, causing life-threatening disease in immunocompromised patients. As it is not primarily a pathogen, but can exist in a commensal state, we aimed at the identification of new anti-infective compounds which do not eradicate the fungus, but primarily disable a virulence determinant. The yeast–hyphae-dimorphism of C. albicans is considered a major contributor to fungal disease, as mutants locked into either yeast or hyphal state have been shown to be less virulent in the mouse-model. We devised a high-throughput screening procedure which allows us to find inhibitors of the induction of hyphae. Hyphae-formation was induced by nitrogen starvation at 37 °C and neutral pH in a reporter strain, which couples promoter activity of the hyphae-specific HWP1 to β-galactosidase expression. In a pilot screening of 720 novel synthetic compounds, we identified substances which inhibited the outgrowth of germ tubes. They belonged to chemical classes not yet known for antimycotic properties, namely methyl aryl-oxazoline carboxylates, dihydrobenzo[d]isoxazolones and thiazolo[4,5-e]benzoisoxazoles. In conclusion we developed a novel screening assay, which addresses the morphological switch from the yeast form of C. albicans to its hyphal form and identified novel chemical structures with activity against C. albicans. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Terroir of yeasts? – Application of FTIR spectroscopy and molecular methods for strain typing of yeasts

    Directory of Open Access Journals (Sweden)

    Gerhards Daniel

    2015-01-01

    Full Text Available The site specific influence on wine (Terroir is an often by wine producers, consumers and scientists discussed topic in the world of wine. A study on grapes and (spontaneous fermentations from six different vineyards was done to investigate the biodiversity of yeasts and to answer the question if there is a terroir of yeast and how it could be influenced. Randomly isolated yeasts were identified by FTIR-spectroscopy and molecular methods on species and strain level. Vineyard specific yeast floras would be observed but they are not such important as expected. Only a few overlapping strain patterns would be identified during both vintages. The yeast flora of the winery had a huge impact on the spontaneous fermentations, but is not really constant and influenced by different factors from outside.

  17. Enhanced phytate dephosphorylation by using Candida melibiosica yeast-based biofuel cell.

    Science.gov (United States)

    Hubenova, Yolina; Georgiev, Danail; Mitov, Mario

    2014-10-01

    We report for the first time that Candida melibiosica expresses enhanced phytase activity when grown under biofuel cell polarization in a nutrient-poor medium, containing only fructose as a carbohydrate source. Phytase activity during the cultivation under polarization reached up to 25 U per g dry biomass, exceeding with 20 ± 3 % those of the control. A participation of the enzyme in the adaptation processes to the stress conditions is proposed. In addition, steady-state electrical outputs were achieved during biofuel cell operation at continuous polarization under constant load. The obtained results show that C. melibiosica yeast-based biofuel cell could be used for simultaneous electricity generation and phytate bioremediation.

  18. Oral yeast carriage in patients with advanced cancer.

    Science.gov (United States)

    Davies, A N; Brailsford, S; Broadley, K; Beighton, D

    2002-04-01

    The aim of this study was to investigate oral yeast carriage amongst patients with advanced cancer. Oral rinse samples were obtained from 120 subjects. Yeasts were isolated using Sabouraud's dextrose agar and CHROMagar Candida, and were identified using a combination of the API 20 C AUX yeast identification system, species-specific PCR and 26S rDNA gene sequencing. Oral yeast carriage was present in 66% of subjects. The frequency of isolation of individual species was: Candida albicans, 46%; Candida glabrata, 18%; Candida dubliniensis, 5%; others, yeast carriage was associated with denture wearing (P = 0.006), and low stimulated whole salivary flow rate (P = 0.009). Identification of these risk factors offers new strategies for the prevention of oral candidosis in this group of patients.

  19. Promising results of cranberry in the prevention of oral Candida biofilms.

    Science.gov (United States)

    Girardot, Marion; Guerineau, Amandine; Boudesocque, Leslie; Costa, Damien; Bazinet, Laurent; Enguehard-Gueiffier, Cécile; Imbert, Christine

    2014-04-01

    In the context of dental caries prevention by natural foodstuff sources, antifungal and antibiofilm activities of dry commercial extracts of cranberry fruit (Vaccinium macrocarpon Aiton) and two other red fruits (Vaccinium myrtillus L. and Malpighia punicifolia L.) were assessed on Candida albicans and Candida glabrata yeasts. When added to the culture medium, the cranberry extract displayed a significant anti-adhesion activity against Candida spp. when used at low concentrations. In addition, the pretreatment of surfaces with this extract induced an anti-adhesion activity mainly against C. glabrata yeasts and an antibiofilm activity against C. albicans. This activity was dependent on concentration, species, and strain. A phytochemical investigation bioguided by anti-adhesion tests against the two Candida species was carried out on crude cranberry juice to determine the active fractions. Three subfractions enriched in proanthocyanidins showed an anti-adhesion activity at low concentrations. This study investigated for the first time the interest of crude extracts of cranberry and cranberry juice fractions to prevent biofilms of C. glabrata. It highlighted the potency of consuming this fruit and using it as a source of anti-adhesion agents. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  20. Candida infection of the skin

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000880.htm Candida infection of the skin To use the sharing features on this page, please enable JavaScript. Candida infection of the skin is a yeast infection ...

  1. Antifungal activity of four honeys of different types from Algeria against pathogenic yeast: Candida albicans and Rhodotorula sp.

    Science.gov (United States)

    Moussa, Ahmed; Noureddine, Djebli; Saad, Aissat; Abdelmelek, Meslem; Abdelkader, Benhalima

    2012-07-01

    To evaluate the antifungal activity of four honeys of different types from Algeria against pathogenic yeast i.e. Candida albicans (C. albicans) and Rhodotorula sp. Four Algeria honeys of different botanical origin were analyzed to test antifungal effect against C. albicans, and Rhodotorula sp. Different concentrations (undiluted, 10%, 30%, 50% and 70% w/v) of honey were studied in vitro for their antifugal activity using C. albicans and Rhodotorula sp. as fungal strains. The range of the diameter of zone of inhibition of various concentrations of tested honeys was (7-23 mm) for Rhodotorula sp., while C. albicans showed clearly resistance towards all concentrations used. The MICs of tested honey concentrations against C. albicans and Rhodotorula sp. were (70.09-93.48)% and (4.90-99.70)% v/v, respectively. This study demonstrates that, in vitro, these natural products have clearly an antifungal activity against Rhodotorula sp. and C. albicans.

  2. Prevalence of Candida tropicalis and Candida krusei in onychomycosis in João Pessoa, Paraiba, Brazil from 1999 to 2010

    Directory of Open Access Journals (Sweden)

    JULIANA M.M. ARRUA

    2015-09-01

    Full Text Available ABSTRACTOver time, as the etiology of onychomycosis has developed, yeasts from the genus Candida have emerged as important etiological agents. This study aimed to determine the frequency of yeast caused onychomycosis in Joao Pessoa, Paraíba, Brazil from 1999 to 2010. A retrospective study from January 1999 to December 2010 evaluated the results of onychomycosis positive direct mycological exams (DME - for yeast and realized in the Hemato(r Clinical Laboratory. Women were the most affected by onychomycosis which occur preferentially in adults, and the toenails are the favorite yeast targets. The prevalent yeasts were Candida tropicalis and C. krusei.

  3. Effect of salt-tolerant yeast of Candida versatilis and Zygosaccharomyces rouxii on the production of biogenic amines during soy sauce fermentation.

    Science.gov (United States)

    Qi, Wei; Hou, Li-Hua; Guo, Hong-Lian; Wang, Chun-Ling; Fan, Zhen-Chuan; Liu, Jin-Fu; Cao, Xiao-Hong

    2014-06-01

    This study aimed to enhance and improve the quality and safety of soy sauce. In the present work, the change of biogenic amines, such as histamine, tyramine, cadaverine, spermidine, was examined by the treatment of Candida versatilis and Zygosaccharomyces rouxii, and the influence of salt-tolerant yeast on biogenic amines was analysed during the whole fermentation process. The results showed that the content of biogenic amines was elevated after yeast treatment and the content of biogenic amines was influenced by using yeast. The dominating biogenic amine in soy sauce was tyramine. At the end of fermentation, the concentrations of biogenic amines produced by Zygosaccharomyces rouxii and Candida versatilis in the soy mash were 122.71 mg kg(-1) and 69.96 mg kg(-1) . The changes of biogenic amines in high-salt liquid soy mash during fermentation process indicated that a variety of biogenic amines were increased in the fermentation ageing period, which may be due to amino acid decarboxylation to form biogenic amines by yeast decarboxylase. The fermentation period of soy sauce should be longer than 5 months because biogenic amines began to decline after this time period. © 2013 Society of Chemical Industry.

  4. Probiotic Lactobacillus reuteri has antifungal effects on oral Candida species in vitro

    DEFF Research Database (Denmark)

    Jørgensen, Mette Rose; Kragelund, Camilla; Jensen, Peter Østrup

    2017-01-01

    Background: An alternative approach for managing Candida infections in the oral cavity by modulating the oral microbiota with probiotic bacteria has been proposed.  Objective: The aim was to investigate the antifungal potential of the probiotic bacterium Lactobacillus reuteri (DSM 17938 and ATCC...... PTA 5289) against six oral Candida species (C. albicans, C. glabrata, C. krusei, C. tropicalis, C. dubliniensis, and C. parapsilosis).  Design: The lactobacilli were tested for their ability to co-aggregate with and inhibit the growth of the yeasts assessed by spectrophotometry and the agar overlay...... inhibition assay. Additionally, the pH was evaluated with microsensors, and the production of hydrogen peroxide (H2O2) by the lactobacilli was verified.  Results: Both L. reuteri strains showed co-aggregation abilities with the yeasts. The lactobacilli almost completely inhibited the growth of C. albicans...

  5. Yeast strains designed for 2. generation bioethanol production. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Roennow, B.

    2013-04-15

    The aim of the project was to develop a suitable fermentation organism for 2G bioethanol production that would efficiently ferment all of the sugars in lignocellulosic biomass into ethanol at a commercially viable rate (comparable to yeast based 1G ethanol production). More specifically, a yeast strain would be developed with the ability to ferment also the pentoses in lignocellulosic biomass and thereby increase the ethanol yield of the process by 30-45% with a profound positive effect on the total process economy. The project has succeeded in developing a new industrial yeast strain V1. The yeast strain can transform the difficult C5 sugars to ethanol from waste products such as straw and the like from the agricultural sector. The classic issues relating to industrial uses such as inhibitor and ethanol tolerance and high ethanol production is resolved satisfactorily. The potential of the use of the new strain for 2nd generation bioethanol production is that the ethanol yields increase by 30-45%. With the increased ethanol yield follows a marked improvement in the overall process economics. (LN)

  6. Microbial succession of Debaryomyces hansenii strains during the production of Danish surfaced-ripened cheeses

    DEFF Research Database (Denmark)

    Petersen, Karen Mee; Westall, Signe; Jespersen, Lene

    2002-01-01

    to be the dominant yeast species throughout the ripening period, whereas other yeast species such as Trichosporon spp., Rhodotorula spp., and Candida spp. were found in minor concentrations during early stages of cheese ripening. Mitochondrial DNA RFLP was used to show that several strains of D. hansenii were...

  7. Isoflavone formononetin from red propolis acts as a fungicide against Candida sp

    Directory of Open Access Journals (Sweden)

    Michelline Viviane Marques das Neves

    2016-03-01

    Full Text Available Abstract A bioassay-guided fractionation of two samples of Brazilian red propolis (from Igarassu, PE, Brazil, hereinafter propolis 1 and 2 was conducted in order to determine the components responsible for its antimicrobial activity, especially against Candida spp. Samples of both the crude powdered resin and the crude ethanolic extract of propolis from both locations inhibited the growth of all 12 tested Candida strains, with a minimum inhibitory concentration of 256 µg/mL. The hexane, acetate and methanol fractions of propolis 1 also inhibited all strains with minimum inhibitory concentration values ranging from 128 to 512 µg/mL for the six bacteria tested and from 32 to 1024 µg/mL for the yeasts. Similarly, hexane and acetate fractions of propolis sample 2 inhibited all microorganisms tested, with minimum inhibitory concentration values of 512 µg/mL for bacteria and 32 µg/mL for yeasts. The extracts were analyzed by HPLC and their phenolic profile allowed us to identify and quantitate one phenolic acid and seven flavonoids in the crude ethanolic extract. Formononetin and pinocembrin were the major constituents amongst the identified compounds. Formononetin was detected in all extracts and fractions tested, except for the methanolic fraction of sample 2. The isolated isoflavone formononetin inhibited the growth of all the microorganisms tested, with a minimum inhibitory concentration of 200 µg/mL for the six bacteria strains tested and 25 µg/mL for the six yeasts. Formononetin also exhibited fungicidal activity against five of the six yeasts tested. Taken together our results demonstrate that the isoflavone formononetin is implicated in the reported antimicrobial activity of red propolis.

  8. [Evaluation of common commercial systems for the identification of yeast isolates in microbiology laboratories: a multicenter study].

    Science.gov (United States)

    Karabıçak, Nilgün; Uludağ Altun, Hatice; Karatuna, Onur; Hazırolan, Gülşen; Aksu, Neriman; Adiloğlu, Ali; Akyar, Işın

    2015-04-01

    Accurate and rapid identification of yeast isolates have become important in recent years for not only antifungal susceptibility testing due to the species-specific clinical resistance breakpoints but also early initiation of appropriate antifungal therapy. In clinical microbiology laboratories species identification of yeasts is often performed with several commercial systems based on biochemical properties and rarely according to the physiological and morphological characteristics. The aim of this study was to compare the two common commercial systems, VITEK 2 YST ID Card (Vitek; bioMérieux, France) and API 20C AUX (API; bioMérieux, France) with conventional mycological methods. A total of 473 clinical yeast strains isolated from clinical specimens in different university and training/research hospitals and identified by Vitek system were included in the study. The isolates were re-identified with API and conventional methods including morphological identification in the Mycology Reference Laboratory of the Public Health Institute of Turkey. Candida dubliniensis MYA 583, Candida krusei ATCC 6258, Candida parapsilosis ATCC 22019, Candida albicans ATCC 10231 and Cryptococcus neoformans ATCC 32268 were used as quality control strains and those standard strains were studied consecutively 10 days with both of the methods. The results of identification by Vitek and API were compared with the results of conventional methods for those 473 yeast isolates [6 genus (Candida, Cryptococcus, Blastoshizomyces, Rhodotorula, Saccharomyces, Trichosporon), 17 species (5 common and 12 rarely isolated)]. The performances of the systems were better (Vitek: 95%; API: 96%) for the commonly detected species (C.albicans, C.parapsilosis, C.glabrata, C.tropicalis and C.krusei) than those for rarely detected species (Vitek: 78.4%; API: 71.6%) (p= 0.155). Misidentification or unidentification were mostly detected for C.parapsilosis (Vitek: 6/87; API: 7/87) and C.glabrata (Vitek: 9/104; API

  9. Whole-Genome Analysis of Three Yeast Strains Used for Production of Sherry-Like Wines Revealed Genetic Traits Specific to Flor Yeasts

    Science.gov (United States)

    Eldarov, Mikhail A.; Beletsky, Alexey V.; Tanashchuk, Tatiana N.; Kishkovskaya, Svetlana A.; Ravin, Nikolai V.; Mardanov, Andrey V.

    2018-01-01

    Flor yeast strains represent a specialized group of Saccharomyces cerevisiae yeasts used for biological wine aging. We have sequenced the genomes of three flor strains originated from different geographic regions and used for production of sherry-like wines in Russia. According to the obtained phylogeny of 118 yeast strains, flor strains form very tight cluster adjacent to the main wine clade. SNP analysis versus available genomes of wine and flor strains revealed 2,270 genetic variants in 1,337 loci specific to flor strains. Gene ontology analysis in combination with gene content evaluation revealed a complex landscape of possibly adaptive genetic changes in flor yeast, related to genes associated with cell morphology, mitotic cell cycle, ion homeostasis, DNA repair, carbohydrate metabolism, lipid metabolism, and cell wall biogenesis. Pangenomic analysis discovered the presence of several well-known “non-reference” loci of potential industrial importance. Events of gene loss included deletions of asparaginase genes, maltose utilization locus, and FRE-FIT locus involved in iron transport. The latter in combination with a flor-yeast-specific mutation in the Aft1 transcription factor gene is likely to be responsible for the discovered phenotype of increased iron sensitivity and improved iron uptake of analyzed strains. Expansion of the coding region of the FLO11 flocullin gene and alteration of the balance between members of the FLO gene family are likely to positively affect the well-known propensity of flor strains for velum formation. Our study provides new insights in the nature of genetic variation in flor yeast strains and demonstrates that different adaptive properties of flor yeast strains could have evolved through different mechanisms of genetic variation. PMID:29867869

  10. [Comparison of Phoenix™ Yeast ID Panel and API® ID 32C commercial systems for the identification of Candida species isolated from clinical samples].

    Science.gov (United States)

    Gayibova, Ülkü; Dalyan Cılo, Burcu; Ağca, Harun; Ener, Beyza

    2014-07-01

    Opportunistic fungal pathogens are one of the important causes of nosocomial infections, and several different types of yeasts, especially Candida species are increasingly recovered from immunocompromised patients. Since many of the yeasts are resistant to the commonly used antifungal agents, the introduction of appropriate therapy depends on rapid and accurate identification. The aims of this study were to compare the commercial identification systems namely API® ID 32C (bioMerieux, France) and Phoenix™ Yeast ID Panel (Becton Dickinson Diagnostics, USA) for the identification of Candida species and to evaluate the effect of morphological findings in the identification process. A total of 211 yeast strains isolated from different clinical samples (111 urine, 34 blood/vascular catheter, 27 upper/lower respiratory tract, 16 abscess/pus, 13 throat/vagina swabs and 10 sterile body fluids) of 137 patients hospitalized in Uludag University Health and Research Center between October 2013 to January 2014, were included in the study. Samples were cultured on blood agar, chromogenic agar (CHROMagar Candida, BD, USA) and Saboraud's dextrose agar (SDA), and isolated yeast colonies were evaluated with germ tube test and morphological examination by microscopy on cornmeal/Tween-80 agar. The isolates were identified as well by two commercial systems according to the manufacturers' recommendations. Discrepant results between the systems were tried to be resolved by using morphological characteristics of the yeasts. Of the isolates 159 were identified identical by both of the systems, and the concordance between those systems were estimated as 75.4%. According to the concordant identification, the most frequently isolated species was C.albicans (44.1%) followed by C.tropicalis (9.9%), C.glabrata (9.5%), C.parapsilosis (8.5%) and C.kefyr (8.1%). The concordance rate was 81.7% in identification of frequently isolated species (C.albicans, C.tropicalis, C.parapsilosis, C.glabrata, C

  11. Antifungal Effect of Novel 2-bromo-2-chloro-2-(4-chlorophenylsulfonyl-1-phenylethanone against Candida strains

    Directory of Open Access Journals (Sweden)

    Monika Staniszewska

    2016-08-01

    Full Text Available We investigated the antifungal activity of novel a 2-bromo-2-chloro-2-(4-chlorophenylsulfonyl-1-phenylethanone (compound 4. The synthesis of compound 4 was commenced from sodium 4-chlorobenzene sulfinate and the final product was obtained by treatment of β-chloro β-keto-sulfone with sodium hypobromite. The sensitivity of sixty three clinical isolates belonging to the most relevant Candida species towards compound 4 using the method M27-A3 was evaluated. We observed among most of the clinical strains of C. albicans MIC ranging from 0.00195 to 0.0078 µg/mL. Compound 4 at 32 μg/mL exhibited fungicidal activity against nine Candida strains tested using the MFC assay. Compound 4 displayed anti-Candida activity (with clear endpoint against 22% of clinical strains of Candida. Under compound 4, Candida susceptibility and tolerance, namely paradoxical effect (PG, was found for only two clinical isolates (C. glabrata and C. parapsilosis and reference strain 14053 using both M27-A3 and MFC method. We found that compound 4 does not induce toxicity in vivo against larvae of Galleria mellonella (≥97% survival and it displays reduced toxicity on mammalian cells in vitro (strain 90028 exhibited no defects in hyphal growth on Caco-2 monolayer under compound 4 influence at MIC= 16 µg/mL. The MIC values of compound 4 against C. albicans 90028, in medium with sorbitol did not suggest that compound 4 acts by inhibiting fungal cell wall synthesis. Our findings with compound 4 suggest a general strategy for antifungal agent development that might be useful in limiting the emergence of resistance in Candida strains.

  12. Production of fermentation aroma compounds by Saccharomyces cerevisiae wine yeasts: effects of yeast assimilable nitrogen on two model strains.

    Science.gov (United States)

    Carrau, Francisco M; Medina, Karina; Farina, Laura; Boido, Eduardo; Henschke, Paul A; Dellacassa, Eduardo

    2008-11-01

    The contribution of yeast fermentation metabolites to the aromatic profile of wine is well documented; however, the biotechnological application of this knowledge, apart from strain selection, is still rather limited and often contradictory. Understanding and modeling the relationship between nutrient availability and the production of desirable aroma compounds by different strains must be one of the main objectives in the selection of industrial yeasts for the beverage and food industry. In order to overcome the variability in the composition of grape juices, we have used a chemically defined model medium for studying yeast physiological behavior and metabolite production in response to nitrogen supplementation so as to identify an appropriate yeast assimilable nitrogen level for strain differentiation. At low initial nitrogen concentrations, strain KU1 produced higher quantities of esters and fatty acids whereas M522 produced higher concentrations of isoacids, gamma-butyrolactone, higher alcohols and 3-methylthio-1-propanol. We propose that although strains KU1 and M522 have a similar nitrogen consumption profile, they represent useful models for the chemical characterization of wine strains in relation to wine quality. The differential production of aroma compounds by the two strains is discussed in relation to their capacity for nitrogen usage and their impact on winemaking. The results obtained here will help to develop targeted metabolic footprinting methods for the discrimination of industrial yeasts.

  13. Phospholipid analogue distributions of Iranian isolates of candida

    International Nuclear Information System (INIS)

    Zarei Mahmoudabadi, A.; Brucker, D.B.

    2004-01-01

    The aim of this study was to analyse polar lipids of candida species isolated from Ahwas (Iran) by fast Atom bombardment mass spectrometry . Nine isolates of Candida Sp. were identified by growth at 45 d ig c , production of chlamydoconidia on cornmeal agar, colonial colour on CHROMagar Candida, germ tube production and ID 32 C kits. Then polar lipids were extracted from freeze-dried cultures and analysed using Fast Atom Bombardment Mass Spectrometry. The most intense carboxylate and phospholipid molecular species anions were of m/z 281 (C 1 8 : 1 ) and m/z 515 (PA 23:2). However, the most intense carboxylate and phospholipid analogues in Candida Parapsilosis were 292 (Un) and 555 (PA 26:3), which differed from other yeasts. Isolates were grouped by single linkage clustering based on correlation coefficient for strain pairs calculated with carboxylate and phospholipid molecular species distributions. Fast Atom Bombardment Mass Spectrometry can differentiate the C. albicans based on analysis of polar lipid distributions.These findings support that differentiation between C. albicans and other species is possible based on polar lipids

  14. One small step for a yeast--microevolution within macrophages renders Candida glabrata hypervirulent due to a single point mutation.

    Directory of Open Access Journals (Sweden)

    Sascha Brunke

    2014-10-01

    Full Text Available Candida glabrata is one of the most common causes of candidemia, a life-threatening, systemic fungal infection, and is surpassed in frequency only by Candida albicans. Major factors contributing to the success of this opportunistic pathogen include its ability to readily acquire resistance to antifungals and to colonize and adapt to many different niches in the human body. Here we addressed the flexibility and adaptability of C. glabrata during interaction with macrophages with a serial passage approach. Continuous co-incubation of C. glabrata with a murine macrophage cell line for over six months resulted in a striking alteration in fungal morphology: The growth form changed from typical spherical yeasts to pseudohyphae-like structures - a phenotype which was stable over several generations without any selective pressure. Transmission electron microscopy and FACS analyses showed that the filamentous-like morphology was accompanied by changes in cell wall architecture. This altered growth form permitted faster escape from macrophages and increased damage of macrophages. In addition, the evolved strain (Evo showed transiently increased virulence in a systemic mouse infection model, which correlated with increased organ-specific fungal burden and inflammatory response (TNFα and IL-6 in the brain. Similarly, the Evo mutant significantly increased TNFα production in the brain on day 2, which is mirrored in macrophages confronted with the Evo mutant, but not with the parental wild type. Whole genome sequencing of the Evo strain, genetic analyses, targeted gene disruption and a reverse microevolution experiment revealed a single nucleotide exchange in the chitin synthase-encoding CHS2 gene as the sole basis for this phenotypic alteration. A targeted CHS2 mutant with the same SNP showed similar phenotypes as the Evo strain under all experimental conditions tested. These results indicate that microevolutionary processes in host-simulative conditions

  15. Genes regulation encoding ADP/ATP carrier in yeasts Saccharomyces cerevisiae and Candida parapsilosis

    International Nuclear Information System (INIS)

    Nebohacova, M.

    2000-01-01

    Genes encoding a mitochondrial ADP/ATP carrier (AAC) in yeast Saccharomyces cerevisiae and Candida parapsilosis were investigated. AAC2 is coding for the major AAC isoform in S. cerevisiae. We suggest that AAC2 is a member of a syn-expression group of genes encoding oxidative phosphorylation proteins. Within our previous studies on the regulation of the AAC2 transcription an UAS (-393/-268) was identified that is essential for the expression of this gene. Two functional regulatory cis-elements are located within this UAS -binding sites for an ABFl factor and for HAP2/3/4/5 heteromeric complex. We examined relative contributions and mutual interactions of the ABFl and HAP2/3/4/5 factors in the activation of transcription from the UAS of the AAC2 gene. The whole UAS was dissected into smaller sub-fragments and tested for (i) the ability to form DNA-protein complexes with cellular proteins in vitro, (ii) the ability to confer heterologous expression using AAC3 gene lacking its own promoter, and (iii) the expression of AAC3-lacZ fusion instead of intact AAC3 gene. The obtained results demonstrated that: a) The whole UAS as well as sub-fragment containing only ABF1-binding site are able to form DNA-protein complexes with cellular proteins in oxygen- and heme- dependent manner. The experiments with antibody against the ABF1 showed that the ABF1 factor is one of the proteins binding to AAC2 promoter. We have been unsuccessful to prove the binding of cellular proteins to the HAP2/3/4/5-binding site. However, the presence of HAP2/3/4/5-binding site is necessary to drive a binding of cellular proteins to the ABF1-binding site in carbon source-dependent manner. b) The presence of both ABF1- and HAP2/3/4/5-binding sites and original spacing between them is necessary to confer the growth of Aaac2 mutant strain on non- fermentable carbon source when put in front of AAC3 gene introduced on centromeric vector to Aaac2 mutant strain. c) For the activation of AAC3-lacZ expression on

  16. Unique C-terminal region of Hap3 is required for methanol-regulated gene expression in the methylotrophic yeast Candida boidinii.

    Science.gov (United States)

    Oda, Saori; Yurimoto, Hiroya; Nitta, Nobuhisa; Sakai, Yasuyoshi

    2016-05-01

    The Hap complex of the methylotrophic yeast Candida boidinii was found to be required for methanol-regulated gene expression. In this study, we performed functional characterization of CbHap3p, one of the Hap complex components in C. boidinii. Sequence alignment of Hap3 proteins revealed the presence of a unique extended C-terminal region, which is not present in Hap3p from Saccharomyces cerevisiae (ScHap3p), but is found in Hap3p proteins of methylotrophic yeasts. Deletion of the C-terminal region of CbHap3p (Δ256-292 or Δ107-237) diminished activation of methanol-regulated genes and abolished the ability to grow on methanol, but did not affect nuclear localization or DNA-binding ability. However, deletion of the N-terminal region of CbHap3p (Δ1-20) led to not only a growth defect on methanol and a decreased level of methanol-regulated gene expression, but also impaired nuclear localization and binding to methanol-regulated gene promoters. We also revealed that CbHap3p could complement the growth defect of the Schap3Δ strain on glycerol, although ScHap3p could not complement the growth defect of a Cbhap3Δ strain on methanol. We conclude that the unique C-terminal region of CbHap3p contributes to maximum activation of methanol-regulated genes, whilst the N-terminal region is required for nuclear localization and binding to DNA.

  17. Identification of uncommon oral yeasts from cancer patients by MALDI-TOF mass spectrometry.

    Science.gov (United States)

    Aslani, Narges; Janbabaei, Ghasem; Abastabar, Mahdi; Meis, Jacques F; Babaeian, Mahasti; Khodavaisy, Sadegh; Boekhout, Teun; Badali, Hamid

    2018-01-08

    Opportunistic infections due to Candida species occur frequently in cancer patients because of their inherent immunosuppression. The aim of the present study was to investigate the epidemiology of yeast species from the oral cavity of patients during treatment for oncological and haematological malignancies. MALDI-TOF was performed to identify yeasts isolated from the oral cavity of 350 cancer patients. Moreover, antifungal susceptibility testing was performed in according to CLSI guidelines (M27-A3). Among 162 yeasts and yeast-like fungi isolated from the oral cavity of cancer patients, Candida albicans was the most common species (50.6%), followed by Candida glabrata (24.7%), Pichia kudriavzevii (Candida krusei (9.9%)), Candida tropicalis (4.3%), Candida dubliniensis (3.7%), Kluyveromyces marxianus (Candida kefyr (3.7%)) and Candida parapsilosis (1%). In addition, uncommon yeast species i.e., Saprochaete capitata, Saccharomyces cerevisiae, Clavispora lusitaniae (C. lusitaniae) and Pichia kluyveri (C. eremophila) were recovered from oral lesions. Oral colonization by C. albicans, non-albicans Candida species and uncommon yeasts were as follow; 55%, 44% and 1%, whereas oral infection due to C. albicans was 33.3%, non-albicans Candida species 60.6%, and uncommon yeasts 6.1%. Poor oral hygiene and xerostomia were identified as independent risk factors associated with oral yeast colonization. The overall resistance to fluconazole was 11.7% (19/162). Low MIC values were observed for anidulafungin for all Candida and uncommon yeast species. This current study provides insight into the prevalence and susceptibility profiles of Candida species, including emerging Candida species and uncommon yeasts, isolated from the oral cavity of Iranian cancer patients. The incidence of oral candidiasis was higher amongst patients with hematological malignancies. The majority of oral infections were caused by non-albicans Candida species which were often more resistant to anti

  18. Study on the IAA (Indole acetic acid) Productivity of Soil Yeast Strain Isolats

    International Nuclear Information System (INIS)

    Nwe Nwe Soe Hlaing; Swe Zin Yu; San San Yu

    2011-12-01

    Twelve isolated soil yeast were tested in IAA production in peptone yeast glucose broth (PYG). All strains were screened for the Indole Acetic Acid (IAA) producing activity in PYG broth supplemented with or without L-Tryptophan (L-TRP) as precusor. IAA production was assayed calorimetrically using Salkowski's reagent. The concentration of IAA produced by yeast strains was measured by spectrophotometric method at 530nm. Y6 strain was the highest IAA producer (79ppm) at 9 days incubation period without tryptophan. Y3, Y10 and Y12 strains that were incubated without L-TRP also had the higher ability in the production of IAA than other yeast isolates. The selected yeasts having high IAA production activity were characterized by morphological study and biochemical tests including sugar assimilation and fermentation tests.

  19. Emerging azole resistance among Candida albicans from clinical ...

    African Journals Online (AJOL)

    Candida albicans is one of the most frequently isolated yeasts in clinical laboratories and accounts for up to 80 % of the yeasts recovered from sites of infection. The study was set out to determine antifungal susceptibility of clinical isolates of Candida albicans and to establish the Minimum Inhibitory Concentrations (MIC) to ...

  20. Biodegradation of used lubricating and diesel oils by a new yeast ...

    African Journals Online (AJOL)

    A new yeast strain, identified by 18S-rRNA gene sequencing as Candida viswanathii KA-201l, was isolated from used lubricating oil, showed high biodegradation efficiency for different used lubricating oils. Capability of this isolate to degrade different high and low molecular weight hydrocarbons, castor oil, diesel oil and ...

  1. Comparative kinetic characterization of catalases from Candida boidinii yeast and bovine liver.

    Science.gov (United States)

    Metelitza, D I; Eryomin, A N; Artzukevich, I M; Chernikevich, I P

    1997-04-01

    Catalase with molecular weight 230 +/- kD was isolated and purified from methylotrophic yeasts Candida boidinii by ion-exchange chromatography. The kinetic characteristics of yeast and bovine liver catalases were compared in the reaction of H2O2 decomposition using a wide range of H2O2 concentrations (up to 0.12 M) and PH (2-10). First order rates constants (k, sec-1) were determined for both enzymes from semi-logarithmic anamorphoses of kinetic curves of H2O2 utilization. Anamorphoses of complete kinetic curves as a function of 1/ln([H2O2]0/[H2O2]t) versus 1/t were used for calculation of the effective rate constants of catalase inactivation during the reaction (k(in), sec-1) and the rate constants of interaction of catalase complex I with the second molecule of H2O2 (k2, M-1.sec-1). The effects of initial catalase concentrations, H2O2, and pH on k, k2, and k(in) were similar for both enzymes. Catalytic constant, k2, and the efficacy expressed as a ratio kcat/Km were 1.87-, 1.45-, and 1.3-fold, respectively, higher for bovine catalase than that of yeast catalase. Operational stability of yeast catalase is 3.5-fold higher than the stability of bovine catalase and much higher during cyclic decomposition of 50 mM H2O2. Enhanced operational stability and inexpensive source of its preparation open prospects for practical applications of yeast catalase for co-immobilization with superoxide dismutase on non-toxic carriers.

  2. Yeast identification by sequencing, biochemical kits, MALDI-TOF MS and rep-PCR DNA fingerprinting.

    Science.gov (United States)

    Zhao, Ying; Tsang, Chi-Ching; Xiao, Meng; Chan, Jasper F W; Lau, Susanna K P; Kong, Fanrong; Xu, Yingchun; Woo, Patrick C Y

    2017-12-08

    No study has comprehensively evaluated the performance of 28S nrDNA and ITS sequencing, commercial biochemical test kits, MALDI-TOF MS platforms, and the emerging rep-PCR DNA fingerprinting technology using a cohort of yeast strains collected from a clinical microbiology laboratory. In this study, using 71 clinically important yeast isolates (excluding Candida albicans) collected from a single centre, we determined the concordance of 28S nrDNA and ITS sequencing and evaluated the performance of two commercial test kits, two MALDI-TOF MS platforms, and rep-PCR DNA fingerprinting. 28S nrDNA and ITS sequencing showed complete agreement on the identities of the 71 isolates. Using sequencing results as the standard, 78.9% and 71.8% isolates were correctly identified using the API 20C AUX and Vitek 2 YST ID Card systems, respectively; and 90.1% and 80.3% isolates were correctly identified using the Bruker and Vitek MALDI-TOF MS platforms, respectively. Of the 18 strains belonging to the Candida parapsilosis species complex tested by DiversiLab automated rep-PCR DNA fingerprinting, all were identified only as Candida parapsilosis with similarities ≥93.2%, indicating the misidentification of Candida metapsilosis and Candida orthopsilosis. However, hierarchical cluster analysis of the rep-PCR DNA fingerprints of these three species within this species complex formed three different discrete clusters, indicating that this technology can potentially differentiate the three species. To achieve higher accuracies of identification, the databases of commercial biochemical test kits, MALDI-TOF MS platforms, and DiversiLab automated rep-PCR DNA fingerprinting needs further enrichment, particularly for uncommonly encountered yeast species. © The Author 2017. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Rapid identification of drug resistant Candida species causing recurrent vulvovaginal candidiasis.

    Science.gov (United States)

    Diba, Kambiz; Namaki, Atefeh; Ayatolahi, Haleh; Hanifian, Haleh

    2012-01-01

    Some yeast agents including Candida albicans, Candida tropicalis and Candida glabrata have a role in recurrent vulvovaginal candidiasis. We studied the frequency of both common and recurrent vulvovaginal candidiasis in symptomatic cases which were referred to Urmia Medical Sciences University related gynecology clinics using morphologic and molecular methods. The aim of this study was the identification of Candida species isolated from recurrent vulvovaginal candidiasis cases using a rapid and reliable molecular method. Vaginal swabs obtained from each case, were cultured on differential media including cornmeal agar and CHROM agar Candida. After 48 hours at 37℃, the cultures were studied for growth characteristics and color production respectively. All isolates were identified using the molecular method of PCR - restriction fragment length polymorphism. Among all clinical specimens, we detected 19 ( 16 % ) non fungal agents, 87 ( 82.1 % ) yeasts and 2 ( 1.9 % ) multiple infections. The yeast isolates identified morphologically included Candida albicans ( n = 62 ), Candida glabrata ( n = 9 ), Candida tropicalis ( n = 8 ), Candida parapsilosis ( n = 8 ) and Candida guilliermondii and Candida krusei ( n = 1 each ). We also obtained very similar results for Candida albicans, Candida glabrata and Candida tropicalis as the most common clinical isolates, by using PCR - Restriction Fragment Length Polymorphism. Use of two differential methods, morphologic and molecular, enabled us to identify most medically important Candida species which particularly cause recurrent vulvovaginal candidiasis.

  4. Structural study of phosphomannan of yeast-form cells of Candida albicans J-1012 strain with special reference to application of mild acetolysis.

    Science.gov (United States)

    Kobayashi, H; Shibata, N; Mitobe, H; Ohkubo, Y; Suzuki, S

    1989-08-01

    Structural analysis of the phosphomannan isolated from yeast-form cells of a pathogenic yeast, Candida albicans J-1012 strain, was conducted. Treatment of this phosphomannan (Fr. J) with 10 mM HCl at 100 degrees C for 60 min gave a mixture of beta-1,2-linked manno-oligosaccharides, from tetraose to biose plus mannose, and an acid-stable mannan moiety (Fr. J-a), which was then acetolyzed by means of an acetolysis medium, 100:100:1 (v/v) mixture of (CH3CO)2O, CH3COOH, and H2SO4, at 40 degrees C for 36 h in order to avoid cleavage of the beta-1,2 linkage. The resultant manno-oligosaccharide mixture was fractionated on a column of Bio-Gel P-2 to yield insufficiently resolved manno-oligosaccharide fractions higher than pentaose and lower manno-oligosaccharides ranging from tetraose to biose plus mannose. The higher manno-oligosaccharide fraction was then digested with the Arthrobacter GJM-1 alpha-mannosidase in order to cleave the enzyme-susceptible alpha-1,2 and alpha-1,3 linkages, leaving manno-oligosaccharides containing the beta-1,2 linkage at their nonreducing terminal sites, Manp beta 1----2Manp alpha 1----2Manp alpha 1----2Manp alpha 1----2Man, Manp beta 1----2Manp beta 1----2Manp alpha 1----2Manp alpha 1---- 2Manp alpha 1----2Man, and Manp beta 1----2Manp beta 1----2Manp beta 1----2Manp alpha 1---- 2Manp alpha 1----2Manp alpha 1----2Man. However, the result of acetolysis of Fr. J-a by means of a 10:10:1 (v/v) mixture of (CH3CO)2O, CH3COOH, and H2SO4 at 40 degrees C for 13 h was significantly different from that obtained by the mild acetolysis method; i.e., the amount of mannose was apparently larger than that formed by the mild acetolysis method. In summary, a chemical structure for Fr. J as a highly branched mannan containing 14 different branching moieties was proposed.

  5. Optimization of Culture Medium Enhances Viable Biomass Production and Biocontrol Efficacy of the Antagonistic Yeast, Candida diversa

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    Jia Liu

    2017-10-01

    Full Text Available Viable biomass production is a key determinant of suitability of antagonistic yeasts as potential biocontrol agents. This study investigated the effects of three metal ions (magnesium, ferrous, and zinc on biomass production and viability of the antagonistic yeast, Candida diversa. Using response surface methodology to optimize medium components, a maximum biomass was obtained, when the collective Mg2+, Fe2+, and Zn2+ concentrations were adjusted in a minimal mineral (MM medium. Compared with the unmodified MM, and three ion-deficient MM media, yeast cells cultured in the three ion-modified MM medium exhibited a lower level of cellular oxidative damage, and a higher level of antioxidant enzyme activity. A biocontrol assay indicated that C. diversa grown in the ion-modified MM exhibited the greatest level of control of gray mold on apple fruit. These results provide new information on culture medium optimization to grow yeast antagonists in order to improve biomass production and biocontrol efficacy.

  6. Comparison of oral Candida species prevalence and carriage among gutka-chewers and betel-quid chewers.

    Science.gov (United States)

    Abduljabbar, Tariq; Hussain, Mudassir; Adnan, Tariq; Vohra, Fahim; Javed, Fawad

    2017-03-01

    To compare prevalence and carriage of Candida species among gutka-chewers and betel-quid-chewers. The cross-sectional case-control study was conducted between January and December, 2015 at the Oral Surgery department of Abbasi Shaheed Hospital and the Dental department of Jinnah Postgraduate Medical Centre, Karachi, and comprised oral yeast samples of gutka-chewers, betel-quid-chewers, and non-chewers. A standardised questionnaire was used to gather demographic data and oral hygiene maintenance information. Oral Candida strains were collected, cultured and identified using standard techniques and yeast identification system. In all groups, unstimulated whole salivary flow rate was determined. Lesions on the tongue and oral mucosa were clinically investigated and numbers of missing teeth were recorded. SPSS 20 was used for data analysis. Of the total 185 samples, 50(27%) were from gutka-chewers, 50(27%)betel-quid-chewers, and 85(46%) non-chewers. Oral Candida carriage was comparable among betel-quid-chewers (18 [36%])and gutka-chewers (20 [40%]), but it was significantly higher than the non-chewers (11 [12.9%]) (pbetel-quid-chewers (p>0.05). Prevalence and carriage of Candida species were comparable between betel-quid-chewers and gutka-chewers compared to non-chewers.

  7. Genetic analysis of D-xylose metabolism by endophytic yeast strains of Rhodotorula graminis and Rhodotorula mucilaginosa

    Directory of Open Access Journals (Sweden)

    Ping Xu

    2011-01-01

    Full Text Available Two novel endophytic yeast strains, WP1 and PTD3, isolated from within the stems of poplar (Populus trees, were genetically characterized with respect to their xylose metabolism genes. These two strains, belonging to the species Rhodotorula graminis and R. mucilaginosa, respectively, utilize both hexose and pentose sugars, including the common plant pentose sugar, D-xylose. The xylose reductase (XYL1 and xylitol dehydrogenase (XYL2 genes were cloned and characterized. The derived amino acid sequences of xylose reductase (XR and xylose dehydrogenase (XDH were 32%~41% homologous to those of Pichia stipitis and Candida. spp., two species known to utilize xylose. The derived XR and XDH sequences of WP1 and PTD3 had higher homology (73% and 69% identity with each other. WP1 and PTD3 were grown in single sugar and mixed sugar media to analyze the XYL1 and XYL2 gene regulation mechanisms. Our results revealed that for both strains, the gene expression is induced by D-xylose, and that in PTD3 the expression was not repressed by glucose in the presence of xylose.

  8. Anaerobic organic acid metabolism of Candida zemplinina in comparison with Saccharomyces wine yeasts.

    Science.gov (United States)

    Magyar, Ildikó; Nyitrai-Sárdy, Diána; Leskó, Annamária; Pomázi, Andrea; Kállay, Miklós

    2014-05-16

    Organic acid production under oxygen-limited conditions has been thoroughly studied in the Saccharomyces species, but practically never investigated in Candida zemplinina, which seems to be an acidogenic species under oxidative laboratory conditions. In this study, several strains of C. zemplinina were tested for organic acid metabolism, in comparison with Saccharomyces cerevisiae, Saccharomyces uvarum and Candida stellata, under fermentative conditions. Only C. stellata produced significantly higher acidity in simple minimal media (SM) with low sugar content and two different nitrogen sources (ammonia or glutamic acid) at low level. However, the acid profile differed largely between the Saccharomyces and Candida species and showed inverse types of N-dependence in some cases. Succinic acid production was strongly enhanced on glutamic acid in Saccharomyces species, but not in Candida species. 2-oxoglutarate production was strongly supported on ammonium nitrogen in Candida species, but remained low in Saccharomyces. Candida species, C. stellata in particular, produced more pyruvic acid regardless of N-sources. From the results, we concluded that the anaerobic organic acid metabolisms of C. zemplinina and C. stellata are different from each other and also from that of the Saccharomyces species. In the formation of succinic acid, the oxidative pathway from glutamic acid seems to play little or no role in C. zemplinina. The reductive branch of the TCA cycle, however, produces acidic intermediates (malic, fumaric, and succinic acid) in a level comparable with the production of the Saccharomyces species. An unidentified organic acid, which was produced on glutamic acid only by the Candida species, needs further investigation. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Culture media profoundly affect Candida albicans and Candida tropicalis growth, adhesion and biofilm development.

    Science.gov (United States)

    Weerasekera, Manjula M; Wijesinghe, Gayan K; Jayarathna, Thilini A; Gunasekara, Chinthika P; Fernando, Neluka; Kottegoda, Nilwala; Samaranayake, Lakshman P

    2016-11-01

    As there are sparse data on the impact of growth media on the phenomenon of biofilm development for Candida we evaluated the efficacy of three culture media on growth, adhesion and biofilm formation of two pathogenic yeasts, Candida albicans and Candida tropicalis. The planktonic phase yeast growth, either as monocultures or mixed cultures, in sabouraud dextrose broth (SDB), yeast nitrogen base (YNB), and RPMI 1640 was compared, and adhesion as well as biofilm formation were monitored using MTT and crystal violet (CV) assays and scanning electron microscopy. Planktonic cells of C. albicans, C. tropicalis and their 1:1 co-culture showed maximal growth in SDB. C. albicans/C. tropicalis adhesion was significantly facilitated in RPMI 1640 although the YNB elicited the maximum growth for C. tropicalis. Similarly, the biofilm growth was uniformly higher for both species in RPMI 1640, and C. tropicalis was the slower biofilm former in all three media. Scanning electron microscopy images tended to confirm the results of MTT and CV assay. Taken together, our data indicate that researchers should pay heed to the choice of laboratory culture media when comparing relative planktonic/biofilm growth of Candida. There is also a need for standardisation of biofilm development media so as to facilitate cross comparisons between laboratories.

  10. Phosphatase activity and culture conditions of the yeast Candida mycoderma sp. and analysis of organic phosphorus hydrolysis ability.

    Science.gov (United States)

    Yan, Mang; Yu, Liufang; Zhang, Liang; Guo, Yuexia; Dai, Kewei; Chen, Yuru

    2014-11-01

    Orthophosphate is an essential but limiting macronutrient for plant growth. About 67% cropland in China lacks sufficient phosphorus, especially that with red soil. Extensive soil phosphorus reserves exist in the form of organic phosphorus, which is unavailable for root uptake unless hydrolyzed by secretory acid phosphatases. Thus, many microorganisms with the ability to produce phosphatase have been exploited. In this work, the activity of an extracellular acid phosphatase and yeast biomass from Candida mycoderma was measured under different culture conditions, such as pH, temperature, and carbon source. A maximal phosphatase activity of 8.47×10(5)±0.11×10(5)U/g was achieved by C. Mycoderma in 36 hr under the optimal conditions. The extracellular acid phosphatase has high activity over a wide pH tolerance range from 2.5 to 5.0 (optimum pH3.5). The effects of different phosphorus compounds on the acid phosphatase production were also studied. The presence of phytin, lecithin or calcium phosphate reduced the phosphatase activity and biomass yield significantly. In addition, the pH of the culture medium was reduced significantly by lecithin. The efficiency of the strain in releasing orthophosphate from organic phosphorus was studied in red soil (used in planting trees) and rice soil (originating as red soil). The available phosphorus content was increased by 230% after inoculating 20 days in rice soil and decreased by 50% after inoculating 10 days in red soil. This work indicates that the yeast strain C. mycoderma has potential application for enhancing phosphorus utilization in plants that grow in rice soil. Copyright © 2014. Published by Elsevier B.V.

  11. Vaginal yeast infection

    Science.gov (United States)

    Yeast infection - vagina; Vaginal candidiasis; Monilial vaginitis ... Most women have a vaginal yeast infection at some time. Candida albicans is a common type of fungus. It is often found in small amounts ...

  12. Search of yeast-like fungi in some lakes of the Tucholski Landscape Park (NW Poland

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    Anna Rózga

    2014-08-01

    Full Text Available The occurrence of pathogenic yeast-like fungi was determined in the catchment of the Suska and Raciąska Struga. Fourteen strains of fungi from 3 genera were isolated: Candida inconspicua, C. lambica, C. glabrata, Rhodotorula rubra, Rh. glutinls and Trichosporon capitatum.

  13. Lactic acid bacteria and yeasts associated with gowé production from sorghum in Bénin.

    Science.gov (United States)

    Vieira-Dalodé, G; Jespersen, L; Hounhouigan, J; Moller, P L; Nago, C M; Jakobsen, M

    2007-08-01

    To identify the dominant micro-organisms involved in the production of gowé, a fermented beverage, and to select the most appropriate species for starter culture development. Samples of sorghum gowé produced twice at three different production sites were taken at different fermentation times. DNA amplification by internal transcribed spacer-polymerase chain reaction of 288 lactic acid bacteria (LAB) isolates and 16S rRNA gene sequencing of selected strains revealed that the dominant LAB responsible for gowé fermentation were Lactobacillus fermentum, Weissella confusa, Lactobacillus mucosae, Pediococcus acidilactici, Pediococcus pentosaceus and Weissella kimchii. DNA from 200 strains of yeasts was amplified and the D1/D2 domain of the 26S rRNA gene was sequenced for selected isolates, revealing that the yeasts species were Kluyveromyces marxianus, Pichia anomala, Candida krusei and Candida tropicalis. Gowé processing is characterized by a mixed fermentation dominated by Lact. fermentum, W. confusa and Ped. acidilactici for the LAB and by K. marxianus, P. anomala and C. krusei for the yeasts. The diversity of the LAB and yeasts identified offers new opportunities for technology upgrading and products development in gowé production. The identified species can be used as possible starter for a controlled fermentation of gowé.

  14. Selection of yeast able to produce ethanol from glucose at 40/sup 0/C

    Energy Technology Data Exchange (ETDEWEB)

    Hacking, A J; Taylor, I W.F.; Hanas, C M

    1984-05-01

    A total of 55 yeast strains selected from 7 genera known to ferment carbohydrates to ethanol were screened for their ability to ferment glucose to ethanol in shaken flask culture at 37/sup 0/, 40/sup 0/ and 45/sup 0/C. Yields of more than 50% of the theoretical maximum were obtained with 28 strains at 37/sup 0/C, but only 12 at 40/sup 0/C. Only 6 could grow at 45/sup 0/C, but they produced poor yields. In general Kluyveromyces strains were more thermotolerant than Saccharomyces and Candida strains, but Saccharomyces strains produced higher ethanol yields. The 8 strains with the highest yields at 40/sup 0/C were evaluated in batch fermentations. Three of these, two Saccharomyces and one Candida, were able to meet minimum commercial targets set at 8% (v/v) ethanol from 14% (w/v) glucose at 40/sup 0/C.

  15. Presence of Staphylococcus spp. and Candida spp. in the human oral cavity

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    Martins Clélia Aparecida de Paiva

    2002-01-01

    Full Text Available The presence of yeasts and staphylococci in the oral cavity is important because they can act as supplementary microbiota and in certain situations can cause oral or systemic diseases. The aim of this work was to study the prevalence of Candida spp. and Staphylococcus spp. in the human oral cavity. Oral rinses were collected from sixty-eight individuals according to the technique described by Samaranayake and MacFarlane and then cultured on Sabouraud medium supplemented with chloramphenicol and Baird-Parker agar. After the incubation period, the microorganisms were isolated and identified through biochemical tests. The data obtained were statistically analysed by ANOVA. Candida spp. were isolated from 61.76% of the examined individuals and C. albicans was the more frequently isolated specie. Staphylococcus spp. were isolated from 95.60% of the individuals and 41 strains were coagulase negative (63%. Among the coagulase positive strains, nine were S. aureus, 11 S. hyicus and 4 S. schleiferi subspecie coagulans. No correlation was observed between the counts (cfu of the isolated Candida spp. and Staphylococcus spp.

  16. [Phenotypic and genotypic identification of Candida strains isolated as nosocomial pathogens].

    Science.gov (United States)

    Sahiner, Fatih; Ergünay, Koray; Ozyurt, Mustafa; Ardıç, Nurittin; Hoşbul, Tuğrul; Haznedaroğlu, Tunçer

    2011-07-01

    Over the last decade, there have been important changes in the epidemiology of Candida infections and antifungal agents used to treat these infections. In recent years, Candida species have emerged as important causes of invasive infections among patients in intensive care units. One of the main goals of this study was to evaluate the molecular epidemiology of infectious Candida species isolated in our hospital and accordingly supply data for hospital infection (HI) control. The other aim of this study was to evaluate effectiveness and practical applicability of traditional and molecular methods used to identify Candida isolates to the species level. A total of 77 Candida strains that were isolated from various clinical specimens of 60 hospitalized patients (29 male, 24 female; 7 were children) were included in the study. Fifty-seven (74%) of those isolates were defined as HI agents according to Centers for Disease Control and Prevention (CDC) criteria. The most common Candida species identified as agents of HI were C.albicans (22; 38.6%), followed by C.tropicalis (14; 24.6%), C.parapsilosis (13; 22.8%), C.glabrata (7; 12.3%) and Candida spp. (1; 1.75%). It was determined that bloodstream (26; 45.6%) and urinary tract infections (24; 42.1%) were the most frequently encountered nosocomial infections caused by Candida species. In addition it was detected that the most frequent causative agent of bloodstream infections was C.parapsilosis (10; 38.5%) and of urinary tract infections was C.albicans (12; 50%). The evaluation of advantages and disadvantages of traditional phenotypic methods [germ tube formation, chlamydospore formation in corn meal agar, growth at 45°C, colony characteristics on CHROMagar Candida medium, carbohydrate assimilation properties detected by API ID 32C (BioMerieux, France) system] and some molecular techniques [polymerase chain reaction (PCR) by using ITS-1, ITS-3 and ITS 4 primers, PCR-Restriction fragment length polymorphism (RFLP), PCRRFLP

  17. Effect of Candida albicans and Candida dubliniensis planktonic/biofilm quorum sensing molecules on yeast morphogenesis

    OpenAIRE

    Henriques, Mariana; Martins, Margarida Isabel Barros Coelho; Azeredo, Joana; Oliveira, Rosário

    2006-01-01

    One of the aims of this work was to study the effect of farnesol, a quorum sensing molecule for Candida albicans, on morphologic inhibition of Candida dubliniensis. The second goal of this work was to confirm if Candida dubliniensis also excreted quorum sensing molecules, on both planktonic and biofilm forms. The results clearly demonstrate that Candida dubliniensis undergoes morphological alterations triggered by farnesol. It was also found that supernatants of Candida dubliniensis and Ca...

  18. Stable current outputs and phytate degradation by yeast-based biofuel cell.

    Science.gov (United States)

    Hubenova, Yolina; Georgiev, Danail; Mitov, Mario

    2014-09-01

    In this paper, we report for the first time that Candida melibiosica 2491 yeast strain expresses enhanced phytase activity when used as a biocatalyst in biofuel cells. The polarization also results in an increase of the yeast biomass. Higher steady-state electrical outputs, assigned to earlier production of an endogenous mediator, were achieved at continuous polarization under constant load. The obtained results prove that the C. melibiosica yeast-based biofuel cell could be used for simultaneous electricity generation and phytate bioremediation. In addition, the higher phytase activity obtained by interruptive polarization suggests a new method for increasing the phytase yield from microorganisms. Copyright © 2014 John Wiley & Sons, Ltd.

  19. Characterization of Candida spp. isolated from vaginal fluid: identification, antifungal susceptibility, and virulence profile - doi: 10.4025/actascihealthsci.v35i1.13557

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    Terezinha Inez Estivalet Svidzinski

    2013-03-01

    Full Text Available A total of 101 (20.0% yeast samples were isolated from vaginal fluids of 504 non-hospitalized patients in Maringá, Paraná State, Brazil and Candida albicans was more frequent specie (93.1% identified by seminested PCR method. All the isolates were susceptible to amphotericin B and nystatin, and 93.1% of them were susceptible to fluconazole. The acid proteinase, hemolytic and phospholipase activities were observed in 99.0, 90.0, and 88.0% of Candida spp., respectively. Around 67.0% of the strains had adherence indexes of 0.5 to 1.5 yeasts by Vero cell, and most of them showed a hydrophilic profile. Correlation studies indicated hydrophilic yeasts presented higher adherence index, proteinase, and phospholipase activities; and a positive correlation between all enzymes was also observed. In addition, the isolates with high hemolytic activity were less susceptible to fluconazole and amphotericin B. These results of Candida prevalence and antifungal susceptibility corroborate with literature’s datas and correlation between virulence factors and MIC values suggest Candida isolates from vaginal fluid less susceptible to antifungal and with higher extracellular enzymes production can be more virulent to cause tissue damage.  

  20. The production and growth characteristics of yeast and mycelial forms of Candida albicans in continuous culture.

    Science.gov (United States)

    Shepherd, M G; Sullivan, P A

    1976-04-01

    The growth characteristics of Candida albicans CM145,348 have been examined under aerobic conditions in continuous culture. At different steady states the environment was controlled with respect to the concentrations of dissolved oxygen, carbon and nitrogen, the pH, and the temperature. Dry matter, substrate concentration, yield, specific oxygen uptake, specific carbon dioxide release and respiration quotient were examined as a function of the dilution rate. The morphology depended on the carbon source. Maltose produced a mycelial morphology, whereas with lactate a yeast culture was obtained. With fructose or glucose as a carbon source a mixed morphology of yeast, pseudo-mycelial and mycelial forms was produced. A larger number of different growth conditions were examined in batch culture but a mixed morphology was always obtained.

  1. Candida infections : detection and epidemiology

    NARCIS (Netherlands)

    Borst, A. (Annemarie)

    2002-01-01

    Despite the fact that the yeast Candida is the number 4 cause of bloodstream infections in the United States and ranks number 8 in Europe, adequate detection methods are lacking. Furthermore, relatively little is known about the epidemiology of Candida. Our aim was to improve the detection and

  2. Effects of Nitrogen Supplementation on Yeast (Candida utilis Biomass Production by Using Pineapple (Ananas comosus Waste Extracted Medium

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    Rosma, A.

    2007-01-01

    Full Text Available Pineapple waste medium was used to cultivate yeast, Candida utilis. It served as the sole carbon and energy source for the yeast growth. However, pineapple waste media contain very little nitrogen (0.003-0.015% w/v. Various nitrogen sources were incorporate and their effects on biomass, yield and productivity were studied. Significant (p<0.05 increment on biomass production was observed when nitrogen supplement (commercial yeast extract, peptone, ammonium dihydrogen phosphate, ammonium sulphate and potassium nitrate was added into fermentation medium. Commercial yeast extract, Maxarome® which increased 55.2% of biomass production at 0.09% (w/v nitrogen content, is the most suitable among the selected organic source. On the other hand, ammonium dihydrogen phosphate at 0.09% (w/v nitrogen content is comparable inorganic source which enhanced 53.7% of production. Total nitrogen content of each treatment at 0.05% (w/v showed that nitrogen supplied was not fully utilized as substrate limitation in the fermentation medium.

  3. Atividade enzimática, produção de slime e sensibilidade a antifúngicos de Candida sp Enzymatic activity, slime production and antifungal agent sensitivity of Candida sp

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    Jaqueline Otero Silva

    2007-06-01

    Full Text Available A habilidade de Candida spp secretar enzimas extracelulares e slime tem sido associada como fatores de patogenicidade. Do total de 37 cepas de Candida sp, 100% foram produtoras de proteinase, 83,8% fosfolipase, 64,9% slime e 100% sensíveis ao fluconazol e itraconazol. Foram encontradas 17 tipagens (enzima/slime. Esta metodologia apresentou um bom índice discriminatório (D=0,93 podendo ser utilizado na caracterização fenotípica das leveduras.Abilith of Candida spp to secrete extracellular enzymes and slime has been associated as pathogenicity factors. Out of a total of 37 strains of Candida sp, 100% were proteinase producers, 83.8% were phospholipase producers, 64.9% were slime producers and 100% were sensitive to fluconazole and itraconazole. Seventeen typings (enzymes/slime were found. This methodology presented a good discrimination rate (D = 0.93 and could be used for phenotypic characterization of yeasts.

  4. Outbreak of candidemia caused by fluconazole resistant Candida parapsilosis strains in an intensive care unit.

    Science.gov (United States)

    Pinhati, Henrique Marconi Sampaio; Casulari, Luiz Augusto; Souza, Ana Carolina Remondi; Siqueira, Ricardo Andreotti; Damasceno, Camila Maria Gomes; Colombo, Arnaldo Lopes

    2016-08-20

    Candidemia is an increasing problem in tertiary care hospitals worldwide. Here, we report the first outbreak of candidemia caused by fluconazole-resistant C. parapsilosis (FRCP) strains in Brazil. This was a cross-sectional study of clinical and microbiological data of all candidemic episodes diagnosed from July 2011 to February 2012 in a 200-bed tertiary care hospital. Initial yeast identification and susceptibility testing were performed using the VITEK 2 - System. Isolates of Candida spp. resistant to fluconazole were sent to a reference laboratory (LEMI-UNIFESP) for further molecular identification and confirmation of resistance by CLSI microdilution test. A multivariate analysis was conducted to identify factors associated with FRCP infection. We identified a total of 40 critically ill patients with candidemia (15 women) with a median age of 70 years. The incidence of candidemia was 6 cases/1,000 patients admissions, including 28 cases (70 %) of infection with C. parapsilosis, 21 of which (75 %) were resistant to fluconazole. In only 19 % of FRCP candidemia cases had fluconazole been used previously. The results of our study indicated that diabetes is a risk factor for FRCP candidemia (p = 0.002). Overall, mortality from candidemia was 45 %, and mortality from episodes of FRCP infections was 42.9 %. The clustering of incident cases in the ICU and molecular typing of strains suggest horizontal transmission of FRCP. Accurate vigilant monitoring for new nosocomial strains of FRCP is required.

  5. Screening and characterizing of xylanolytic and xylose-fermenting yeasts isolated from the wood-feeding termite, Reticulitermes chinensis.

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    Sameh Samir Ali

    Full Text Available The effective fermentation of xylose remains an intractable challenge in bioethanol industry. The relevant xylanase enzyme is also in a high demand from industry for several biotechnological applications that inevitably in recent times led to many efforts for screening some novel microorganisms for better xylanase production and fermentation performance. Recently, it seems that wood-feeding termites can truly be considered as highly efficient natural bioreactors. The highly specialized gut systems of such insects are not yet fully realized, particularly, in xylose fermentation and xylanase production to advance industrial bioethanol technology as well as industrial applications of xylanases. A total of 92 strains from 18 yeast species were successfully isolated and identified from the gut of wood-feeding termite, Reticulitermes chinensis. Of these yeasts and strains, seven were identified for new species: Candida gotoi, Candida pseudorhagii, Hamamotoa lignophila, Meyerozyma guilliermondii, Sugiyamaella sp.1, Sugiyamaella sp. 2, and Sugiyamaella sp.3. Based on the phylogenetic and phenotypic characterization, the type strain of C. pseudorhagii sp. nov., which was originally designated strain SSA-1542T, was the most frequently occurred yeast from termite gut samples, showed the highly xylanolytic activity as well as D-xylose fermentation. The highest xylanase activity was recorded as 1.73 and 0.98 U/mL with xylan or D-xylose substrate, respectively, from SSA-1542T. Among xylanase-producing yeasts, four novel species were identified as D-xylose-fermenting yeasts, where the yeast, C. pseudorhagii SSA-1542T, showed the highest ethanol yield (0.31 g/g, ethanol productivity (0.31 g/L·h, and its fermentation efficiency (60.7% in 48 h. Clearly, the symbiotic yeasts isolated from termite guts have demonstrated a competitive capability to produce xylanase and ferment xylose, suggesting that the wood-feeding termite gut is a promising reservoir for novel

  6. Antimicrobial activity of yeasts against some pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    Gamal Younis

    2017-08-01

    Full Text Available Aim: This study was designed to isolate and identify yeast species from milk and meat products, and to test their antimicrobial activity against some bacterial species. Materials and Methods: A total of 160 milk and meat products samples were collected from random sellers and super markets in New Damietta city, Damietta, Egypt. Samples were subjected to yeast isolation procedures and tested for its antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. In addition, all yeast species isolates were subjected to polymerase chain reaction (PCR for detection of khs (kievitone hydratase and pelA (pectate degrading enzyme genes. Results: The recovery rate of yeasts from sausage was 20% (2/10 followed by kareish cheese, processed cheese, and butter 10% (1/10 each as well as raw milk 9% (9/100, and fruit yoghurt 30% (6/20. Different yeast species were recovered, namely, Candida kefyr (5 isolates, Saccharomyces cerevisiae (4 isolates, Candida intermedia (3 isolates, Candida tropicalis (2 isolates, Candida lusitaniae (2 isolates, and Candida krusei (1 isolate. khs gene was detected in all S. cerevisiae isolates, however, pelA gene was not detected in all identified yeast species. Antimicrobial activity of recovered yeasts against the selected bacterial species showed high activity with C. intermedia against S. aureus and E. coli, C. kefyr against E. coli, and C. lusitaniae against S. aureus. Moderate activities were obtained with C. tropicalis, C. lusitaniae, and S. cerevisiae against E. coli; meanwhile, all the tested yeasts revealed a very low antimicrobial activity against P. aeruginosa. Conclusion: The obtained results confirmed that some kinds of yeasts have the ability to produce antimicrobial compounds that could inhibit some pathogenic and spoilage bacteria and these antimicrobial activity of yeasts enables them to be one of the novel agents in controlling spoilage of food.

  7. Comparison of DNA-based techniques for differentiation of production strains of ale and lager brewing yeast.

    Science.gov (United States)

    Kopecká, J; Němec, M; Matoulková, D

    2016-06-01

    Brewing yeasts are classified into two species-Saccharomyces pastorianus and Saccharomyces cerevisiae. Most of the brewing yeast strains are natural interspecies hybrids typically polyploids and their identification is thus often difficult giving heterogenous results according to the method used. We performed genetic characterization of a set of the brewing yeast strains coming from several yeast culture collections by combination of various DNA-based techniques. The aim of this study was to select a method for species-specific identification of yeast and discrimination of yeast strains according to their technological classification. A group of 40 yeast strains were characterized using PCR-RFLP analysis of ITS-5·8S, NTS, HIS4 and COX2 genes, multiplex PCR, RAPD-PCR of genomic DNA, mtDNA-RFLP and electrophoretic karyotyping. Reliable differentiation of yeast to the species level was achieved by PCR-RFLP of HIS4 gene. Numerical analysis of the obtained RAPD-fingerprints and karyotype revealed species-specific clustering corresponding with the technological classification of the strains. Taxonomic position and partial hybrid nature of strains were verified by multiplex PCR. Differentiation among species using the PCR-RFLP of ITS-5·8S and NTS region was shown to be unreliable. Karyotyping and RFLP of mitochondrial DNA evinced small inaccuracies in strain categorization. PCR-RFLP of HIS4 gene and RAPD-PCR of genomic DNA are reliable and suitable methods for fast identification of yeast strains. RAPD-PCR with primer 21 is a fast and reliable method applicable for differentiation of brewing yeasts with only 35% similarity of fingerprint profile between the two main technological groups (ale and lager) of brewing strains. It was proved that PCR-RFLP method of HIS4 gene enables precise discrimination among three technologically important Saccharomyces species. Differentiation of brewing yeast to the strain level can be achieved using the RAPD-PCR technique. © 2016 The

  8. [Onychomycosis by yeast not common in diabetics of a health center].

    Science.gov (United States)

    Imbert, J L; G Gomez, J V; Escudero, R B; Blasco, J L

    2016-10-01

    Mexican diabetic population frequently presents mycosis under foot hyperkeratosis; however, in another type of onychomycosis as the ones that is assumed Candida albicans is the causal agent, it is unknown the frequency, the prevalence and if another Candida species or other yeasts are found. Evaluate the frequency of yeasts causing onychomycosis in diabetic patients looked after in public institutions of health of the State of Hidalgo, Mexico, and its association with clinical epidemiological variables. An observational, descriptive and transversal study was made on 261 patients, from which one nail sample of each one was obtained, used to isolate and identify dermatophytes and yeasts; the results were statistically correlated with 24 epidemiological parameters. The clinical study was done through interrogation and by medical exploration in order to evaluate Tinea pedis and onychomycosis. Onychomycosis were caused by Candida guilliermondii, Candida parapsilosis, Candida glabrata, Candida krusei, Candida spp., Kodamaea ohmeri, Prototheca wickerhamii and unidentified yeasts. The prevalence for general onychomycosis, by dermatophytes, mixed onychomycosis and by yeasts were: 24.1, 19.5, 2.3 and 14.6%, respectively. Patients with significant probability to be diagnosed as having onychomycosis by yeasts are those wearing open shoes (2.59%); technicians and professionals (10.49%) and alcohol drinkers (3.72%). The fact that Candida albicans is not present in this study as causal agent of onychomycosis, and emerging and non-common yeasts were indeed isolated, creates new challenges. It is remarked the clinical criterion that when onychomycosis is suspected in diabetics, the diagnosis for culturing dermatophytes and yeasts should be included. Copyright © 2015 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España, S.L.U. All rights reserved.

  9. Enhanced oxidative killing of azole-resistant Candida glabrata strains with ERG11 deletion.

    Science.gov (United States)

    Kan, V L; Geber, A; Bennett, J E

    1996-01-01

    The susceptibility of genetically defined Candida glabrata strains to killing by H2O2 and neutrophils was assessed. Fluconazole-susceptible L5L and L5D strains demonstrated survival rates higher than those of two fluconazole-resistant strains lacking the ERG11 gene coding for 14 alpha-demethylase. Fluconazole resistance can occur by mechanisms which increase fungal susceptibility to oxidative killing by H2O2 and neutrophils. PMID:8807069

  10. In vitro synergistic activity of lidocaine and miconazole against Candida albicans

    Directory of Open Access Journals (Sweden)

    Maria da Conceição dos Santos Oliveira Cunha

    2017-08-01

    Full Text Available Candida albicans is the main yeast isolated from vulvovaginal candidiasis(VVC and a major antifungal used to treat VVC is miconazole (MZ, it shows local toxic effects, such as irritation and burns. The lidocaine (LD is a local anesthetic. The aim of this study was to evaluate the synergistic activity of LD/MZ against 19 strains of C. albicans isolated from vaginal secretion. 78.9% of the strains were susceptible to the combination LD/MZ, demonstrating synergism of drugs. These drugs can be used to produce vaginal creams to treat VVC, especially drug resistant.

  11. ISOLASI SPESIES CANDIDA DARI TINJA PENDERITA HIV/AIDS

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    Pudji K Sjarifuddin

    2002-12-01

    Full Text Available Candida is a saprophyte in the human respiratory tract, gastro intestinal tract and also in the debris under the nail. Inpatients with compromised immunity such as HIV-AIDS, Candida is able to cause infection, in this case oral candidosisor esophagitis. In this study fungi were isolated from the stools of HIV/AIDS patients. Samples consisting of 95diarrheic stools from HIV/AIDS patients were investigated for the yeast especially Candida spp. The stools were inoculated onto Sabouraud dextrose agar then the fungi were identified using morphological methods and Chromagarmedium. Yeast colonies were found in 71 (74,74% out of 95 samples from which Candida was 42 44,21%, Geotrichum 24 (25,26%, and mixed of Candida and Geotrichum 3 (3,16%, Rhodotorula and Trichosporon 1(1,05% each. Species of Candida were identified as C. albicans, C. tropicalis, C. krusei, C. guilliermondii, C. glabrata, C. lusitaniae and C. kefyr. Although Candida could be isolated from the diarrheic stools of HIV/AIDS patients but its role on the cause of diarrhea is still questionable.

  12. Candida spp. occurrence in oral cavities of breastfeeding infants and in their mothers' mouths and breasts

    Directory of Open Access Journals (Sweden)

    Zöllner Maria Stella Amorim da Costa

    2003-01-01

    Full Text Available This study aimed to determine the occurrence of Candida spp. in the oral cavity of predominantly breastfed infants and in their mothers' mouths and breasts, as well as in the oral cavity of bottlefed infants and in non-lactating women. One hundred and sixty nine women and eighty-five milk-fed infants took part in this study and were divided into four groups: 1 infants predominantly on breastfeeding (n = 55 and their mothers (n = 55; 2 infants on bottlefeeding (n = 30; 3 non-lactating women on whom oral collections were performed (n = 80 and, 4 non-lactating women on whom breast collections were performed (n = 34. Oral and mammary swabs were cultured on Sabouraud agar dextrose with chloramphenicol. The Candida yeast strains found were isolated and identified through morphological and biochemical tests. Candida species were much less frequent in infants who were predominantly breastfed than in those who were bottlefed. Yeasts were much more frequent on the breasts of lactating women, with statistical difference in relation to the control group.

  13. Evaluation of SOC for the presumptive identification of Candida albicans and Cryptococcus neoformans.

    Science.gov (United States)

    Fleming, W H; Knezek, K L; Dorn, G L

    1987-01-01

    SOC, a fungal growth medium composed of Solryth, oxgall, and caffeic acid, was evaluated as a medium to provide rapid, differential identification of Candida albicans and Cryptococcus neoformans. Using a variety of common isolation media to produce the yeast inocula, the germ tube methods tested ranked in the following order of decreasing sensitivity: SOC (97% +/- 1), serum (92% +/- 5), rabbit coagulase plasma with EDTA in combination with tryptic soy broth (89% +/- 5), TOC (89% +/- 6), and rabbit coagulase plasma with EDTA (83% +/- 4). In chlamydospore production, SOC also proved to be the most sensitive after 24 h incubation: SOC (96% +/- 2), TOC (80% +/- 2), and cornmeal-Tween 80 agar (14% +/- 3). Other medically important yeasts showed normal patterns of growth within 24 h on SOC, thus assisting in their identification. Eighty strains of Cryptococcus neoformans showed characteristic brown pigmentation on SOC and TOC within 18 h, while all other species of the genus Cryptococcus and 229 Candida isolates did not show a change in pigmentation.

  14. Synergism between hydrogen peroxide and seventeen acids against five agri-food-borne fungi and one yeast strain.

    Science.gov (United States)

    Martin, H; Maris, P

    2012-12-01

    The objective of this study was to evaluate fungicidal efficacy of hydrogen peroxide administered in combination with 17 mineral and organic acids authorized for use in the food industry. The assays were performed on a 96-well microplate using a microdilution technique based on the checkerboard titration method. The six selected strains (one yeast and five fungi) were reference strains and strains representative of contaminating fungi found in the food industry. Each synergistic hydrogen peroxide/acid combination found after fifteen minutes contact time at 20 °C in distilled water was then tested in conditions simulating four different use conditions. Twelve combinations were synergistic in distilled water, eleven of these remained synergistic with one or more of the four mineral and organic interfering substances selected. Hydrogen peroxide/formic acid combination remained effective against four strains and was never antagonistic against the other two fungi. Combinations with propionic acid and acetic acid stayed synergistic against two strains. Those with oxalic acid and lactic acid kept their synergism only against Candida albicans. No synergism was detected against Penicillium cyclopium. Synergistic combinations of disinfectants were revealed, among them the promising hydrogen peroxide/formic acid combination. A rapid screening method developed in our laboratory for bacteria was adapted to fungi and used to reveal the synergistic potential of disinfectants and/or sanitizers combinations. © 2012 The Society for Applied Microbiology.

  15. Comparative transcript profiling of Candida albicans and Candida dubliniensis identifies SFL2, a C. albicans gene required for virulence in a reconstituted epithelial infection model.

    LENUS (Irish Health Repository)

    Spiering, Martin J

    2010-02-01

    Candida albicans and Candida dubliniensis are closely related species displaying differences in virulence and genome content, therefore providing potential opportunities to identify novel C. albicans virulence genes. C. albicans gene arrays were used for comparative analysis of global gene expression in the two species in reconstituted human oral epithelium (RHE). C. albicans (SC5314) showed upregulation of hypha-specific and virulence genes within 30 min postinoculation, coinciding with rapid induction of filamentation and increased RHE damage. C. dubliniensis (CD36) showed no detectable upregulation of hypha-specific genes, grew as yeast, and caused limited RHE damage. Several genes absent or highly divergent in C. dubliniensis were upregulated in C. albicans. One such gene, SFL2 (orf19.3969), encoding a putative heat shock factor, was deleted in C. albicans. DeltaDeltasfl2 cells failed to filament under a range of hypha-inducing conditions and exhibited greatly reduced RHE damage, reversed by reintroduction of SFL2 into the DeltaDeltasfl2 strain. Moreover, SFL2 overexpression in C. albicans triggered hyphal morphogenesis. Although SFL2 deletion had no apparent effect on host survival in the murine model of systemic infection, DeltaDeltasfl2 strain-infected kidney tissues contained only yeast cells. These results suggest a role for SFL2 in morphogenesis and an indirect role in C. albicans pathogenesis in epithelial tissues.

  16. [Distribution of Candida species in vaginal specimens and evaluation of CHROMagar Candida medium].

    Science.gov (United States)

    Gültekin, Berna; Yazici, Vesile; Aydin, Neriman

    2005-07-01

    Identification of Candida species is important to guide treatment in vulvovaginal candidiasis which is seen frequently and needs long-term therapy due to recurrence. The aim of this study was to determine the species distribution of Candida isolated from vaginal specimens and evaluation of CHROMagar Candida medium in the laboratory diagnosis. Samples from 80 patients who were clinically diagnosed as vaginitis have been analysed in our laboratory. Colonies appeared on CHROMagar Candida media after 48 hours of incubation at 35 degrees C were evaluated for their colors and characteristics. Candida strains were identified by germ tube test, growth on corn meal Tween 80 agar and when necessary also by API 20 C AUX commercial kit. A total of 84 Candida strains were isolated from 80 patients. Two different Candida species have been isolated from four (5%) of the samples. Among Candida strains isolated, 45 (53.6%) were C. albicans, 29 (34.5%) C. glabrata, 7 (8.3%) C. krusei, and 3 (3.6%) C. kefyr. All of the C. albicans and six of the seven C. krusei isolates have been identified correctly by CHROMagar Candida medium. These results showed that C. albicans is still the most frequently isolated species from vaginal samples. It was concluded that CHROMagar Candida medium is useful for identification of colonies due to frequently seen Candida species and also in differentiation of multiple Candida species grown on the same culture.

  17. Sensitivity of Candida albicans to essential oils: are they an alternative to antifungal agents?

    Science.gov (United States)

    Bona, E; Cantamessa, S; Pavan, M; Novello, G; Massa, N; Rocchetti, A; Berta, G; Gamalero, E

    2016-12-01

    Candida albicans is an important opportunistic pathogen, responsible for the majority of yeast infections in humans. Essential oils, extracted from aromatic plants, are well-known antimicrobial agents, characterized by a broad spectrum of activities, including antifungal properties. The aim of this work was to assess the sensitivity of 30 different vaginal isolated strains of C. albicans to 12 essential oils, compared to the three main used drugs (clotrimazole, fluconazole and itraconazole). Thirty strains of C. albicans were isolated from vaginal swab on CHROMagar ™ Candida. The agar disc diffusion method was employed to determine the sensitivity to the essential oils. The antifungal activity of the essential oils and antifungal drugs (clotrimazole, itraconazole and fluconazole) were investigated using a microdilution method. Transmission and scanning electron microscopy analyses were performed to get a deep inside on cellular damages. Mint, basil, lavender, tea tree oil, winter savory and oregano essential oils inhibited both the growth and the activity of C. albicans more efficiently than clotrimazole. Damages induced by essential oils at the cellular level were stronger than those caused by clotrimazole. Candida albicans is more sensitive to different essential oils compared to the main used drugs. Moreover, the essential oil affected mainly the cell wall and the membranes of the yeast. The results of this work support the research for new alternatives or complementary therapies against vaginal candidiasis. © 2016 The Society for Applied Microbiology.

  18. Effects of photoprotection and reversible inactivation of the yeast Candida guilliermondii, induced by 313 nm light

    International Nuclear Information System (INIS)

    Frajkin, G.Ya.; Pospelov, M.E.; Rubin, L.B.

    1976-01-01

    The results of studies on the effect of near uv light on the yeast Candida guilliermondii are presented. It was shown that certain doses of 313 nm light inactivated the yeast. The detailed affect is shown in the loss of the ability of the cells to form microcolonies and outwardly does not differ from inactivation caused by 254 nm uv. It was concluded that the cell destruction caused by the 313 nm light was not due to damage to DNA. Experiments in which yeast cells were inactivated by 313 nm light before plating on agar and held for some time in a non-nutrient medium permitted observation of recovery of their viability. A difference was shown in the level of repair of yeasts irradiated by 313 nm light (up to 100% recovery) and 254 nm light (60% recovery). The nature of the dependence of the photoprotection on the 313 nm light dose was determined. A decrease in photoprotection was noted, starting with 7x10 -7 einstein/cm 2 , with its complete disappearance upon further dose increase. It is suggested that, in this recovery of the yeast, some other, thus far unknown, mechanism participates. Data were obtained on the survival of yeast irradiated with lethal uv doses. Of special importance, in the authors' opinion, is the fact that, for the photoprotection effect to appear, some time is needed between actions of the 313 and 254 nm lights, which suggests a photoinduced formation in the yeast cells of compounds that protect them from lethal injury

  19. New Lager Brewery Strains Obtained by Crossing Techniques Using Cachaça (Brazilian Spirit) Yeasts

    Science.gov (United States)

    Figueiredo, Bruna Inez Carvalho; Saraiva, Margarete Alice Fontes; de Souza Pimenta, Paloma Patrick; de Souza Testasicca, Miriam Conceição; Sampaio, Geraldo Magela Santos; da Cunha, Aureliano Claret; Afonso, Luis Carlos Crocco; Vieira de Queiroz, Marisa; de Miranda Castro, Ieso

    2017-01-01

    ABSTRACT The development of hybrids has been an effective approach to generate novel yeast strains with optimal technological profile for use in beer production. This study describes the generation of a new yeast strain for lager beer production by direct mating between two Saccharomyces cerevisiae strains isolated from cachaça distilleries: one that was strongly flocculent, and the other with higher production of acetate esters. The first step in this procedure was to analyze the sporulation ability and reproductive cycle of strains belonging to a specific collection of yeasts isolated from cachaça fermentation vats. Most strains showed high rates of sporulation, spore viability, and homothallic behavior. In order to obtain new yeast strains with desirable properties useful for lager beer production, we compare haploid-to-haploid and diploid-to-diploid mating procedures. Moreover, an assessment of parental phenotype traits showed that the segregant diploid C2-1d generated from a diploid-to-diploid mating experiment showed good fermentation performance at low temperature, high flocculation capacity, and desirable production of acetate esters that was significantly better than that of one type lager strain. Therefore, strain C2-1d might be an important candidate for the production of lager beer, with distinct fruit traces and originating using a non-genetically modified organism (GMO) approach. IMPORTANCE Recent work has suggested the utilization of hybridization techniques for the generation of novel non-genetically modified brewing yeast strains with combined properties not commonly found in a unique yeast strain. We have observed remarkable traits, especially low temperature tolerance, maltotriose utilization, flocculation ability, and production of volatile aroma compounds, among a collection of Saccharomyces cerevisiae strains isolated from cachaça distilleries, which allow their utilization in the production of beer. The significance of our research is in

  20. In vitro effects of glycyrrhetinic acid and hyaluronic acid on the growth of vulvovaginal Candida albicans and other yeasts

    Directory of Open Access Journals (Sweden)

    Martina Stevan

    2017-12-01

    Full Text Available Aims. The present study aimed to test the in vitro activity against Candida albicans and non-albicans strains of 18-β glycyrrhetinic acid (18-β GA and hyaluronic acid (HA, both alone and in combination. This antimicrobial activity was assessed using the National Committee for Clinical Laboratory Standards (NCCLS method on Candida strains that were isolated from patients with recurrent vulvovaginal candidiasis (RVVC. Results. Our results demonstrate that the anti-Candida activity is independent from antifungal susceptibility level and the fact that the growth inhibition is stronger at acidic pH level makes the two drugs a promising biological alternative for the topical treatment of vulvovaginal candidiasis (VVC and RVVC. Conclusions. Furthermore, the reduction of both budding cells formation and germ tube elongation, on mammalian cell monolayers, may explain the observed growth inhibition and suggest a decreased virulence, respectively.

  1. Retrospective study of Candida sp. contaminations of endoscopes at the University Hospital of Tlemcen (Algeria).

    Science.gov (United States)

    Hassaine-Lahfa, I; Boucherit-Otmani, Z; Sari-Belkherroubi, L; Boucherit, K

    2017-06-01

    Improper cleaning and disinfection of endoscopes has been responsible for multiple nosocomial outbreaks and sometimes serious life-threatening infections. The aim of our study is, at first, to identify Candida species responsible for the contamination of endoscopes, and to determine the minimal inhibitory concentrations of planktonic (MIC) and sessile cells (SMIC) of amphotericin B (AmB) against our isolated strains. The present study was performed on four endoscopes in the department of gastroenterology at the University Hospital of Tlemcen (Algeria). A total of 300 samples from endoscopes were examined over a period of 3years. Thirty-four strains of Candida sp. were isolated, representing 11.33% of the considered samples. The number of isolated strains dropped significantly in the second and the third year compared to the first year of our study. After testing the antifungal property of amphotericin B, we showed clearly that the sessile cells of Candida sp. were much more resistant than their planktonic counterparts (suspended cells). The methods of sterilization of the endoscopes are very important; drying by compressed air is a critical step that reduces significantly the number of yeasts contamination. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  2. [Antimycotic activity in vitro and in vivo of 5-fluorocytosine on pathogenic strains of Candida albicans and Cryptococcus neoformans].

    Science.gov (United States)

    Costa, A L; Valenti, A; Costa, G; Calogero, F

    1976-01-01

    The authors have analyzed the 5 Fluoro Cytosine (5FC) activity on strains of Candida albicans and Criptococcus neoformans, both in vitro and in vivo. In vitro the minimal inhibitory concentration (MIC) was determined; in vivo tests of pathogenicity on rabbit and mouse have been executed. The various findings obtained have shown a strong activity of the 5FC on strains of Candida and Criptococcus.

  3. A Comparison of Two Yeast MnSODs: Mitochondrial Saccharomyces cerevisiae versus Cytosolic Candida albicans

    International Nuclear Information System (INIS)

    Sheng, Y.; Cabelli, D.; Stich, T.A.; Barnese, K.; Gralla, E.B.; Cascio, D.; Britt, R.D.; Valentine, J.S.

    2011-01-01

    Human MnSOD is significantly more product-inhibited than bacterial MnSODs at high concentrations of superoxide (O 2 - ). This behavior limits the amount of H 2 O 2 produced at high [O 2 - ]; its desirability can be explained by the multiple roles of H 2 O 2 in mammalian cells, particularly its role in signaling. To investigate the mechanism of product inhibition in MnSOD, two yeast MnSODs, one from Saccharomyces cerevisiae mitochondria (ScMnSOD) and the other from Candida albicans cytosol (CaMnSODc), were isolated and characterized. ScMnSOD and CaMnSODc are similar in catalytic kinetics, spectroscopy, and redox chemistry, and they both rest predominantly in the reduced state (unlike most other MnSODs). At high [O 2 - ], the dismutation efficiencies of the yeast MnSODs surpass those of human and bacterial MnSODs, due to very low level of product inhibition. Optical and parallel-mode electron paramagnetic resonance (EPR) spectra suggest the presence of two Mn 3+ species in yeast Mn 3+ SODs, including the well-characterized 5-coordinate Mn 3+ species and a 6-coordinate L-Mn 3+ species with hydroxide as the putative sixth ligand (L). The first and second coordination spheres of ScMnSOD are more similar to bacterial than to human MnSOD. Gln154, an H-bond donor to the Mn-coordinated solvent molecule, is slightly further away from Mn in yeast MnSODs, which may result in their unusual resting state. Mechanistically, the high efficiency of yeast MnSODs could be ascribed to putative translocation of an outer-sphere solvent molecule, which could destabilize the inhibited complex and enhance proton transfer from protein to peroxide. Our studies on yeast MnSODs indicate the unique nature of human MnSOD in that it predominantly undergoes the inhibited pathway at high [O 2 - ].

  4. Determination of some virulence factors of Candida spp. isolated from locally produced cheese in Diyala Governorate-Iraq

    Directory of Open Access Journals (Sweden)

    Suhail Jawdat Fadihl

    2017-03-01

    Full Text Available Locally produced cheese which called (Gibin Al arab is one of the most common dairy products in Iraq, it has an economic importance and great social value. This research aimed to identify yeast species from locally produced cheese (Gibin Al Arab in Diyala city which traditionally made and sold in markets of old town in Baquba, and study some of virulence factors (Esterase production, Phospholipase and Hemolytic production of yeasts belong to genus of Candida . All cheese samples showed contamination with varying number of yeast, total 88 yeast isolates obtained from 70 cheese samples, they were Geotrichum candidum(20.5%, Rhodotorela species(19.4%, Candida parapsilosis (18%, Candida albicans (13.6%, Candida  tropicalis (10.5%, Candida krusei (8%, Saccharomyces cerevisice (3.3% and mixed yeast (un identified at rate of (6.7%. Species of Candida formed half of the total isolates and the most prevalent isolate of Candida spp. was Candida parapsilosis .According to the results determining of  (Esterase production, Phospholipase and Hemolytic production as a virulence factors identifying Candida spp. these activities referred that all isolates of Candida spp. show one or more of these activities and that isolates of  medically important species Candida albicans were the most virulent isolates. this referred to the importance of take attention about consuming of such types of dairy products and need for applying more hygienic measures during handling, processing of milk and form of storage and/or selling of cheese.

  5. Species Distribution and Susceptibility to Azoles of Vaginal Yeasts Isolated Prostitutes

    Directory of Open Access Journals (Sweden)

    Norma T. Gross

    2007-01-01

    Full Text Available Objective. We investigated the use of miconazole among female prostitutes in Costa Rica as well as the distribution of vaginal yeasts and the susceptibility pattern to azoles of strains obtained from this population. Our intention was to relate a frequent use of miconazole to occurrence of vaginal yeasts resistant to azoles. Methods. Vaginal samples were taken from 277 patients that have previously used azoles. Vaginal swabs were obtained for direct microscopy and culture. Yeast isolates were identified by germ tube test and assimilation pattern. Susceptibility testing was determined using a tablet diffusion method. Results. The number of clinical Candida isolates (one from each patient was 57 (20.6%. C. albicans was the predominant species (70%, followed by C. parapsilosis (12%, C. tropicalis (5.3%, C. glabrata and C. famata (3.5% each, C. krusei, C. inconspicua and C. guilliermondii (1.7% each. The majority of vaginal Candida isolates were susceptible to ketoconazole (91%, fluconazole (96.5%, and itraconazole (98%. A lower susceptibility of some isolates to miconazole (63% was observed as compared to the other azoles tested. Moreover, the strains, nonsusceptible to miconazole, were more often obtained from patients that have used this antifungal at least four times within the last year before taking the samples as compared to those with three or less treatments (P<.01. Conclusion. An indiscriminate use of miconazole, such as that observed among female prostitutes in Costa Rica, results in a reduced susceptibility of vaginal yeasts to miconazole but not to other azoles.

  6. Transcriptional Regulation and the Diversification of Metabolism in Wine Yeast Strains

    Science.gov (United States)

    Rossouw, Debra; Jacobson, Dan; Bauer, Florian F.

    2012-01-01

    Transcription factors and their binding sites have been proposed as primary targets of evolutionary adaptation because changes to single transcription factors can lead to far-reaching changes in gene expression patterns. Nevertheless, there is very little concrete evidence for such evolutionary changes. Industrial wine yeast strains, of the species Saccharomyces cerevisiae, are a geno- and phenotypically diverse group of organisms that have adapted to the ecological niches of industrial winemaking environments and have been selected to produce specific styles of wine. Variation in transcriptional regulation among wine yeast strains may be responsible for many of the observed differences and specific adaptations to different fermentative conditions in the context of commercial winemaking. We analyzed gene expression profiles of wine yeast strains to assess the impact of transcription factor expression on metabolic networks. The data provide new insights into the molecular basis of variations in gene expression in industrial strains and their consequent effects on metabolic networks important to wine fermentation. We show that the metabolic phenotype of a strain can be shifted in a relatively predictable manner by changing expression levels of individual transcription factors, opening opportunities to modify transcription networks to achieve desirable outcomes. PMID:22042577

  7. [Evaluation of a rapid trehalase test for the identification of Candida glabrata].

    Science.gov (United States)

    Kirdar, Sevin; Gültekin, Berna; Evcil, Gonca; Ozkütük, Aydan; Sener, Asli Gamze; Aydin, Neriman

    2009-04-01

    Candida species which cause local infections, may also lead to fatal systemic infections. The increasing incidence of non-albicans Candida, especially fluconazole susceptible or resistant dose-dependent C. glabrata, increased the importance of rapid and accurate species level identification for Candida. Rapid and correct identification of C. glabrata is essential for the initiation of the appropriate antifungal therapy. This study was conducted to evaluate the performance of the rapid trehalase test in the diagnosis of C. glabrata isolates. A total of 173 Candida strains isolated from various clinical specimens and identified according to germ tube test, growth on cornmeal Tween 80 agar and the colony morphologies on Mast-CHROMagar Candida medium (Mast Diagnostics, UK), were included to the study. The identification of non-albicans Candida species were also confirmed by API 20CAUX (BioMerieux, France) system. Accordingly 86 (50%) of the isolates were identified as C. glabrata, 48 (28%) C. albicans, 17 (10%) C. krusei, 13 (8%) C. tropicalis, 5 (3%) C. parapsilosis, 3 (2%) C. kefyr and 1 (1%) Cutilis. In order to detect the presence of trehalase enzyme in Condida strains, all isolates were grown on Sabouraud dextrose agar containing 4% glucose and then one yeast colony was emulsified in 50 microl of citrate buffer containing 4% (wt/vol) trehalose for 3 h at 37 degrees C. Presence of glucose which emerged after the action of trehalase on trehalose, was detected by a commercial "urinary glucose detection dipstick" (Spinreacta, Spain). All C. glabrata strains yielded positive result by trehalase test. None C. glabrata isolates were found negative by trehalase test except for one strain of C. tropicalis. In this study, the trehalase test allowed identification of C. globrata with 100% sensitivity and 98.9% specificity. It was concluded that trehalase test is a rapid, cost-effective and simple test that can be used for the accurate identification of C. glabrata.

  8. Bactericidal activity of culture fluid components of Lactobacillus fermentum strain 90 TS-4 (21) clone 3, and their capacity to modulate adhesion of Candida albicans yeast-like fungi to vaginal epithelial cells.

    Science.gov (United States)

    Anokhina, I V; Kravtsov, E G; Protsenko, A V; Yashina, N V; Yermolaev, A V; Chesnokova, V L; Dalin, M V

    2007-03-01

    Antagonistic activities of L. fermentum strain 90 TS-4 (21), L. casei ATCC 27216, and L. acidophilus ATCC 4356 and bactericidal activity of lactobacillus culture fluid towards E. coli strain K12, S. aureus, and S. epidermidis test cultures were studied. The bactericidal effect of L. fermentum strain 90 TS-4 (21) clone 3 culture fluid preparation (pH 6.0) on the test cultures was dose-dependent. Adhesion of C. albicans yeast-like fungi to vaginal epitheliocytes was more pronounced for strains isolated from women with asymptomatic infection than for strains isolated from women with manifest forms. L. fermentum strain 90 TS-4 (21) clone 3 culture fluid preparation modulated adhesion of yeast-like fungi only if the fungal strain was initially highly adherent.

  9. Oral Yeast Colonization and Fungal Infections in Peritoneal Dialysis Patients: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Liliana Simões-Silva

    2017-01-01

    Full Text Available Peritonitis and exit-site infections are important complications in peritoneal dialysis (PD patients that are occasionally caused by opportunistic fungi inhabiting distant body sites. In this study, the oral yeast colonization of PD patients and the antifungal susceptibility profile of the isolated yeasts were accessed and correlated with fungal infection episodes in the following 4 years. Saliva yeast colonization was accessed in 21 PD patients and 27 healthy controls by growth in CHROMagar-Candida® and 18S rRNA/ITS sequencing. PD patients presented a lower oral yeast prevalence when compared to controls, namely, Candida albicans. Other species were also isolated, Candida glabrata and Candida carpophila. The antifungal susceptibility profiles of these isolates revealed resistance to itraconazole, variable susceptibility to caspofungin, and higher MIC values of posaconazole compared to previous reports. The 4-year longitudinal evaluation of these patients revealed Candida parapsilosis and Candida zeylanoides as PD-related exit-site infectious agents, but no correlation was found with oral yeast colonization. This pilot study suggests that oral yeast colonization may represent a limited risk for fungal infection development in PD patients. Oral yeast isolates presented a variable antifungal susceptibility profile, which may suggest resistance to some second-line drugs, highlighting the importance of antifungal susceptibility assessment in the clinical practice.

  10. Isolation, selection and evaluation of yeasts for use in fermentation of coffee beans by the wet process.

    Science.gov (United States)

    de Melo Pereira, Gilberto Vinícius; Soccol, Vanete Thomaz; Pandey, Ashok; Medeiros, Adriane Bianchi Pedroni; Andrade Lara, João Marcos Rodrigues; Gollo, André Luiz; Soccol, Carlos Ricardo

    2014-10-01

    During wet processing of coffee, the ripe cherries are pulped, then fermented and dried. This study reports an experimental approach for target identification and selection of indigenous coffee yeasts and their potential use as starter cultures during the fermentation step of wet processing. A total of 144 yeast isolates originating from spontaneously fermenting coffee beans were identified by molecular approaches and screened for their capacity to grow under coffee-associated stress conditions. According to ITS-rRNA gene sequencing, Pichia fermentans and Pichia kluyveri were the most frequent isolates, followed by Candida Candida glabrata, quercitrusa, Saccharomyces sp., Pichia guilliermondii, Pichia caribbica and Hanseniaspora opuntiae. Nine stress-tolerant yeast strains were evaluated for their ability to produce aromatic compounds in a coffee pulp simulation medium and for their pectinolytic activity. P. fermentans YC5.2 produced the highest concentrations of flavor-active ester compounds (viz., ethyl acetate and isoamyl acetate), while Saccharomyces sp. YC9.15 was the best pectinase-producing strain. The potential impact of these selected yeast strains to promote flavor development in coffee beverages was investigated for inoculating coffee beans during wet fermentation trials at laboratory scale. Inoculation of a single culture of P. fermentans YC5.2 and co-culture of P. fermentans YC5.2 and Saccharomyces sp. YC9.15 enhanced significantly the formation of volatile aroma compounds during the fermentation process compared to un-inoculated control. The sensory analysis indicated that the flavor of coffee beverages was influenced by the starter cultures, being rated as having the higher sensory scores for fruity, buttery and fermented aroma. This demonstrates a complementary role of yeasts associated with coffee quality through the synthesis of yeast-specific volatile constituents. The yeast strains P. fermentans YC5.2 and Saccharomyces sp. YC9.15 have a great

  11. Biofortification of folates in white wheat bread by selection of yeast strain and process.

    Science.gov (United States)

    Hjortmo, Sofia; Patring, Johan; Jastrebova, Jelena; Andlid, Thomas

    2008-09-30

    We here demonstrate that folate content in yeast fermented food can be dramatically increased by using a proper (i) yeast strain and (ii) cultivation procedure for the selected strain prior to food fermentation. Folate levels were 3 to 5-fold higher in white wheat bread leavened with a Saccharomyces cerevisiae strain CBS7764, cultured in defined medium and harvested in the respiro-fermentative phase of growth prior to dough preparation (135-139 microg/100 dry matter), compared to white wheat bread leavened with commercial Baker's yeast (27-43 microg/100 g). The commercial Baker's yeast strain had been industrially produced, using a fed-batch process, thereafter compressed and stored in the refrigerator until bakings were initiated. This strategy is an attractive alternative to fortification of bread with synthetically produced folic acid. By using a high folate producing strain cultured a suitable way folate levels obtained were in accordance with folic acid content in fortified cereal products.

  12. Yeast Monitoring of Wine Mixed or Sequential Fermentations Made by Native Strains from D.O. “Vinos de Madrid” Using Real-Time Quantitative PCR

    Science.gov (United States)

    García, Margarita; Esteve-Zarzoso, Braulio; Crespo, Julia; Cabellos, Juan M.; Arroyo, Teresa

    2017-01-01

    There is an increasing trend toward understanding the impact of non-Saccharomyces yeasts on the winemaking process. Although Saccharomyces cerevisiae is the predominant species at the end of fermentation, it has been recognized that the presence of non-Saccharomyces species during alcoholic fermentation can produce an improvement in the quality and complexity of the final wines. A previous work was developed for selecting the best combinations between S. cerevisiae and five non-Saccharomyces (Torulaspora delbrueckii, Schizosaccharomyces pombe, Candida stellata, Metschnikowia pulcherrima, and Lachancea thermotolorans) native yeast strains from D.O. “Vinos de Madrid” at the laboratory scale. The best inoculation strategies between S. cerevisiae and non-Saccharomyces strains were chosen to analyze, by real-time quantitative PCR (qPCR) combined with the use of specific primers, the dynamics of inoculated populations throughout the fermentation process at the pilot scale using the Malvar white grape variety. The efficiency of the qPCR system was verified independently of the samples matrix, founding the inoculated yeast species throughout alcoholic fermentation. Finally, we can validate the positive effect of selected co-cultures in the Malvar wine quality, highlighting the sequential cultures of T. delbrueckii CLI 918/S. cerevisiae CLI 889 and C. stellata CLI 920/S. cerevisiae CLI 889 and, mixed and sequential cultures of L. thermotolerans 9-6C combined with S. cerevisiae CLI 889. PMID:29326669

  13. Yeast Monitoring of Wine Mixed or Sequential Fermentations Made by Native Strains from D.O. “Vinos de Madrid” Using Real-Time Quantitative PCR

    Directory of Open Access Journals (Sweden)

    Margarita García

    2017-12-01

    Full Text Available There is an increasing trend toward understanding the impact of non-Saccharomyces yeasts on the winemaking process. Although Saccharomyces cerevisiae is the predominant species at the end of fermentation, it has been recognized that the presence of non-Saccharomyces species during alcoholic fermentation can produce an improvement in the quality and complexity of the final wines. A previous work was developed for selecting the best combinations between S. cerevisiae and five non-Saccharomyces (Torulaspora delbrueckii, Schizosaccharomyces pombe, Candida stellata, Metschnikowia pulcherrima, and Lachancea thermotolorans native yeast strains from D.O. “Vinos de Madrid” at the laboratory scale. The best inoculation strategies between S. cerevisiae and non-Saccharomyces strains were chosen to analyze, by real-time quantitative PCR (qPCR combined with the use of specific primers, the dynamics of inoculated populations throughout the fermentation process at the pilot scale using the Malvar white grape variety. The efficiency of the qPCR system was verified independently of the samples matrix, founding the inoculated yeast species throughout alcoholic fermentation. Finally, we can validate the positive effect of selected co-cultures in the Malvar wine quality, highlighting the sequential cultures of T. delbrueckii CLI 918/S. cerevisiae CLI 889 and C. stellata CLI 920/S. cerevisiae CLI 889 and, mixed and sequential cultures of L. thermotolerans 9-6C combined with S. cerevisiae CLI 889.

  14. Different Candida parapsilosis clinical isolates and lipase deficient strain trigger an altered cellular immune response

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    Renata eToth

    2015-10-01

    Full Text Available Numerous human diseases can be associated with fungal infections either as potential causative agents or as a result of changed immune status due to a primary disease. Fungal infections caused by Candida species can vary from mild to severe dependent upon the site of infection, length of exposure and past medical history. Patients with impaired immune status are at increased risk for chronic fungal infections. Recent epidemiologic studies have revealed the increasing incidence of candidiasis caused by non-albicans species such as C. parapsilosis. Due to its increasing relevance we chose two distinct C. parapsilosis strains, to describe the cellular innate immune response towards this species. In the first section of our study we compared the interaction of CLIB 214 and GA1 cells with murine and human macrophages. Both strains are commonly used to investigate C. parapsilosis virulence properties. CLIB 214 is a rapidly pseudohyphae-forming strain and GA1 is an isolate that mainly exists in a yeast form. Our results showed, that the phagocyte response was similar in terms of overall uptake, however differences were observed in macrophage migration and engulfment of fungal cells. As C. parapsilosis releases extracellular lipases in order to promote host invasion we further investigated the role of these secreted components during the distinct stages of the phagocytic process. Using a secreted lipase deficient mutant strain and the parental strain GA1 individually and simultaneously, we confirmed that fungal secreted lipases influence the fungi’s virulence by detecting altered innate cellular responses.In this study we report that two isolates of a single species can trigger markedly distinct host responses and that lipase secretion plays a role on the cellular level of host pathogen interactions.

  15. Biodegradasi minyak oleh Rhodotorula dan Candida hasil isolasi dari Pelabuhan Tanjung Perak Surabaya

    Directory of Open Access Journals (Sweden)

    Tri Nurhariyati

    2012-02-01

    Full Text Available A research about isolation and capability of isolat yeast from Tanjung Perak Harbor, Surabaya in degrading kerosen, gas oil ,and lubricant were conducted. This research were done to know the influence of Rhodotorula, Candida and Mix of Rhodotorula and Candida; the influence of oil type and interaction of both (between yeast and oil in decreasing oil weight. Research design was laboratory experimental and using the factorial 4 × 3 with five replication. The data were analyzed by two-way ANOVA (p: 0.05 and followed by t test. The result of the biodegradation test showed that the kind of yeast, the kind of oil weight and interaction of both influence in decreasing of oil weight. The most decreasing of oil weight obtained by mix of Rhodotorula and Candida (82.55%, kerosen (66.59% and combination mix of yeast (Rhodotorula and Candida and kerosen (89.32%.

  16. [Proteinase activity in Candida albicans strains isolated from the oral cavity of immunocompromised patients, with oral candidiasis and in healthy subjects].

    Science.gov (United States)

    Hernández-Solís, Sandra E; Rueda-Gordillo, Florencio; Rojas-Herrera, Rafael A

    2014-01-01

    Candida albicans has a variety of virulence factors, including secreted aspartyl proteases, which are determinant factors in the pathogenesis of this yeast in immunocompromised patients. Proteinase activity was identified in C. albicans strains isolated from the oral cavity of immunocompromised patients with cancer, diabetes and HIV+, with oral candidiasis and in healthy subjects. Two hundred and fifty C. albicans strains were analyzed, distributed in 5 different groups: patients with cancer, diabetes, HIV+, with oral candidiasis and healthy subjects. Proteolytic activity was identified in 46% of the strains from cancer patients, 54% from HIV+ patients, 60% from diabetics, 70% from oral candidiasis patients, and 42% from healthy subjects. Activity was higher in strains from immunocompromised and oral candidiasis patients than in healthy subjects. Differences were observed between the candidiasis-healthy, candidiasis-HIV+, and diabetic-healthy groups. No differences were observed between the oral candidiasis, diabetes and cancer patients, between the diabetes and HIV+ patients, or between the cancer patients, HIV+ patients and healthy subjects. The present results suggest that although secreted aspartyl proteases are important in the pathogenesis of C. albicans, their activity depends on host conditions. Copyright © 2012 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  17. The dectin-1/inflammasome pathway is responsible for the induction of protective T-helper 17 responses that discriminate between yeasts and hyphae of Candida albicans.

    Science.gov (United States)

    Cheng, Shih-Chin; van de Veerdonk, Frank L; Lenardon, Megan; Stoffels, Monique; Plantinga, Theo; Smeekens, Sanne; Rizzetto, Lisa; Mukaremera, Liliane; Preechasuth, Kanya; Cavalieri, Duccio; Kanneganti, Thirumala Devi; van der Meer, Jos W M; Kullberg, Bart Jan; Joosten, Leo A B; Gow, Neil A R; Netea, Mihai G

    2011-08-01

    In the mucosa, the immune pathways discriminating between colonizing and invasive Candida, thus inducing tolerance or inflammation, are poorly understood. Th17 responses induced by Candida albicans hyphae are central for the activation of mucosal antifungal immunity. An essential step for the discrimination between yeasts and hyphae and induction of Th17 responses is the activation of the inflammasome by C. albicans hyphae and the subsequent release of active IL-1β in macrophages. Inflammasome activation in macrophages results from differences in cell-wall architecture between yeasts and hyphae and is partly mediated by the dectin-1/Syk pathway. These results define the dectin-1/inflammasome pathway as the mechanism that enables the host immune system to mount a protective Th17 response and distinguish between colonization and tissue invasion by C. albicans.

  18. Effect of Saccharomyces, Non-Saccharomyces Yeasts and Malolactic Fermentation Strategies on Fermentation Kinetics and Flavor of Shiraz Wines

    Directory of Open Access Journals (Sweden)

    Heinrich du Plessis

    2017-12-01

    Full Text Available The use of non-Saccharomyces yeasts to improve complexity and diversify wine style is increasing; however, the interactions between non-Saccharomyces yeasts and lactic acid bacteria (LAB have not received much attention. This study investigated the interactions of seven non-Saccharomyces yeast strains of the genera Candida, Hanseniaspora, Lachancea, Metschnikowia and Torulaspora in combination with S. cerevisiae and three malolactic fermentation (MLF strategies in a Shiraz winemaking trial. Standard oenological parameters, volatile composition and sensory profiles of wines were investigated. Wines produced with non-Saccharomyces yeasts had lower alcohol and glycerol levels than wines produced with S. cerevisiae only. Malolactic fermentation also completed faster in these wines. Wines produced with non-Saccharomyces yeasts differed chemically and sensorially from wines produced with S. cerevisiae only. The Candida zemplinina and the one L. thermotolerans isolate slightly inhibited LAB growth in wines that underwent simultaneous MLF. Malolactic fermentation strategy had a greater impact on sensory profiles than yeast treatment. Both yeast selection and MLF strategy had a significant effect on berry aroma, but MLF strategy also had a significant effect on acid balance and astringency of wines. Winemakers should apply the optimal yeast combination and MLF strategy to ensure fast completion of MLF and improve wine complexity.

  19. Solving ethanol production problems with genetically modified yeast strains

    Directory of Open Access Journals (Sweden)

    A. Abreu-Cavalheiro

    2013-09-01

    Full Text Available The current world demand for bioethanol is increasing as a consequence of low fossil fuel availability and a growing number of ethanol/gasoline flex-fuel cars. In addition, countries in several parts of the world have agreed to reduce carbon dioxide emissions, and the use of ethanol as a fuel (which produces fewer pollutants than petroleum products has been considered to be a good alternative to petroleum products. The ethanol that is produced in Brazil from the first-generation process is optimized and can be accomplished at low cost. However, because of the large volume of ethanol that is produced and traded each year, any small improvement in the process could represent a savings of billions dollars. Several Brazilian research programs are investing in sugarcane improvement, but little attention has been given to the improvement of yeast strains that participate in the first-generation process at present. The Brazilian ethanol production process uses sugarcane as a carbon source for the yeast Saccharomyces cerevisiae. Yeast is then grown at a high cellular density and high temperatures in large-capacity open tanks with cells recycle. All of these culture conditions compel the yeast to cope with several types of stress. Among the main stressors are high temperatures and high ethanol concentrations inside the fermentation tanks during alcohol production. Moreover, the competition between the desired yeast strains, which are inoculated at the beginning of the process, with contaminants such as wild type yeasts and bacteria, requires acid treatment to successfully recycle the cells. This review is focused on describing the problems and stressors within the Brazilian ethanol production system. It also highlights some genetic modifications that can help to circumvent these difficulties in yeast.

  20. Solving ethanol production problems with genetically modified yeast strains.

    Science.gov (United States)

    Abreu-Cavalheiro, A; Monteiro, G

    2013-01-01

    The current world demand for bioethanol is increasing as a consequence of low fossil fuel availability and a growing number of ethanol/gasoline flex-fuel cars. In addition, countries in several parts of the world have agreed to reduce carbon dioxide emissions, and the use of ethanol as a fuel (which produces fewer pollutants than petroleum products) has been considered to be a good alternative to petroleum products. The ethanol that is produced in Brazil from the first-generation process is optimized and can be accomplished at low cost. However, because of the large volume of ethanol that is produced and traded each year, any small improvement in the process could represent a savings of billions dollars. Several Brazilian research programs are investing in sugarcane improvement, but little attention has been given to the improvement of yeast strains that participate in the first-generation process at present. The Brazilian ethanol production process uses sugarcane as a carbon source for the yeast Saccharomyces cerevisiae. Yeast is then grown at a high cellular density and high temperatures in large-capacity open tanks with cells recycle. All of these culture conditions compel the yeast to cope with several types of stress. Among the main stressors are high temperatures and high ethanol concentrations inside the fermentation tanks during alcohol production. Moreover, the competition between the desired yeast strains, which are inoculated at the beginning of the process, with contaminants such as wild type yeasts and bacteria, requires acid treatment to successfully recycle the cells. This review is focused on describing the problems and stressors within the Brazilian ethanol production system. It also highlights some genetic modifications that can help to circumvent these difficulties in yeast.

  1. Species distribution and drug susceptibility of candida in clinical isolates from a tertiary care centre at Indore

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    N Pahwa

    2014-01-01

    Full Text Available Background: The incidence of fungal infections has increased significantly, contributing to morbidity and mortality. This is caused by an alarming increase in infections with multi-drug resistant bacteria leading to overuse of broad-spectrum antimicrobials, which lead to overgrowth of Candida, thus enhancing its opportunity to cause disease. Candida are major human fungal pathogens that cause both mucosal and deep tissue infections. Objective : The aim of our study was to identify the distribution of Candida species among clinical isolates and their sensitivity pattern for common antifungal drugs. Materials and Methods : Two hundred and thirty-seven different clinical isolates of Candida were collected from patients visiting to a tertiary care centre of Indore from 2010 to 2012. Identification of Candida species as well as antifungal sensitivity testing was performed with Vitek2 Compact (Biomerieux France using vitek 2 cards for identification of yeast and yeast like organisms (ID-YST cards. Antifungal susceptibility testing was performed with Vitek2 "Fungal Susceptibility Card (AST YS01 kits respectively. Results : We found that the non-albicans Candida were more prevalent than Candida albicans in paediatric (60 year patients than other age group (4-18, 19-60 years patients and also in intensive care unit (ICU patients as compared to out patient department (OPD patients. Resistance rates for amphotericin B, fluconazole, flucytosine, itraconazole, and voriconazole were 2.9%, 5.9%, 0.0%, 4.2% and 2.5%%, respectively. All the strains of C. krusei were found resistant to fluconazole with intermediate sensitivity to flucytosine. Conclusion: Species-level identification of Candida and their antifungal sensitivity testing should be performed to achieve better clinical results.

  2. Relationship between ethanol and oxidative stress in laboratory and brewing yeast strains.

    Science.gov (United States)

    Bleoanca, Iulia; Silva, Ana Rita Courelas; Pimentel, Catarina; Rodrigues-Pousada, Claudina; Menezes, Regina de Andrade

    2013-12-01

    Ethanol is a chemical stress factor that inhibits cellular growth and determines metabolic changes leading to reduction of cell viability during fermentation and yeast storage. To determine the effect of time, temperature and ethanol during storage of brewing yeasts we have monitored viability of cells stored for 72 h, at 6 °C or 12 °C, in the presence of various ethanol concentrations. Under the conditions tested, 6 °C is the most favourable temperature to store brewing yeast creams emphasizing the importance of a tight temperature control in the storage vessels. Because W210 is less resistant to storage in the presence of ethanol than W34/70, the optimal storage parameters obtained under our laboratory conditions vary significantly. The ale strain is sensitive to storage under ethanol concentrations higher than 5% (v/v) for more than 48 h at 6 °C whereas at the same temperature the lager strain tolerates ethanol up to 7.5% (v/v) for 72 h. Also, the viability assays indicate that the antioxidant protein Yap1 is an important factor to storage resistance of BY4741 laboratory strain. To investigate the molecular mechanisms underlying tolerance of brewing yeast strains to ethanol, we have performed phenotypic analysis, localization studies and have monitored the activation of antioxidant and protection genes as well as the intracellular contents of glycogen and trehalose. Overall, our data suggest that the ale strain W210 has a defective antioxidant defence system and that ethanol may induce the antioxidant defences as well as glycogen and trehalose protection mechanisms in laboratory and brewing yeast strains. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  3. Study of puromycin and acridic orange strain effect on photoprotection of yeasts Candida guillermondii from the lethal action of short-wave ultraviolet

    International Nuclear Information System (INIS)

    Fraikin, G.Ya.; Strakhovskaya, M.G.; Rubvin, L.B.

    1980-01-01

    The synthesis inhibitor of puromycin albumen has been used to establish that photoprotection formation in yeasts of a hypothetic compound which protects DNA from lethal damages, is not connected with macromolecular synthesis. The combined effect of photoprotective light and acridic orange strain on cells has been studied. It is shown that the mechanism in the base of the protector action is analogous to the mechanism of DNA protection with acridic orange

  4. Engineered CRISPR/Cas9 system for multiplex genome engineering of polyploid industrial yeast strains.

    Science.gov (United States)

    Lian, Jiazhang; Bao, Zehua; Hu, Sumeng; Zhao, Huimin

    2018-06-01

    The CRISPR/Cas9 system has been widely used for multiplex genome engineering of Saccharomyces cerevisiae. However, its application in manipulating industrial yeast strains is less successful, probably due to the genome complexity and low copy numbers of gRNA expression plasmids. Here we developed an efficient CRISPR/Cas9 system for industrial yeast strain engineering by using our previously engineered plasmids with increased copy numbers. Four genes in both a diploid strain (Ethanol Red, 8 alleles in total) and a triploid strain (ATCC 4124, 12 alleles in total) were knocked out in a single step with 100% efficiency. This system was used to construct xylose-fermenting, lactate-producing industrial yeast strains, in which ALD6, PHO13, LEU2, and URA3 were disrupted in a single step followed by the introduction of a xylose utilization pathway and a lactate biosynthetic pathway on auxotrophic marker plasmids. The optimized CRISPR/Cas9 system provides a powerful tool for the development of industrial yeast based microbial cell factories. © 2018 Wiley Periodicals, Inc.

  5. A new methodology to obtain wine yeast strains overproducing mannoproteins.

    Science.gov (United States)

    Quirós, Manuel; Gonzalez-Ramos, Daniel; Tabera, Laura; Gonzalez, Ramon

    2010-04-30

    Yeast mannoproteins are highly glycosylated proteins that are covalently bound to the beta-1,3-glucan present in the yeast cell wall. Among their outstanding enological properties, yeast mannoproteins contribute to several aspects of wine quality by protecting against protein haze, reducing astringency, retaining aroma compounds and stimulating growth of lactic-acid bacteria. The development of a non-recombinant method to obtain enological yeast strains overproducing mannoproteins would therefore be very useful. Our previous experience on the genetic determinants of the release of these molecules by Saccharomyces cerevisiae has allowed us to propose a new methodology to isolate and characterize wine yeast that overproduce mannoproteins. The described methodology is based on the resistance of the killer 9 toxin produced by Williopsis saturnus, a feature linked to an altered biogenesis of the yeast cell wall. Copyright 2010 Elsevier B.V. All rights reserved.

  6. PCR melting profile (PCR MP - a new tool for differentiation of Candida albicans strains

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    Nowak Magdalena

    2009-11-01

    Full Text Available Abstract Background We have previously reported the use of PCR Melting Profile (PCR MP technique based on using low denaturation temperatures during ligation mediated PCR (LM PCR for bacterial strain differentiation. The aim of the current study was to evaluate this method for intra-species differentiation of Candida albicans strains. Methods In total 123 Candida albicans strains (including 7 reference, 11 clinical unrelated, and 105 isolates from patients of two hospitals in Poland were examined using three genotyping methods: PCR MP, macrorestriction analysis of the chromosomal DNA by pulsed-field gel electrophoresis (REA-PFGE and RAPD techniques. Results The genotyping results of the PCR MP were compared with results from REA-PFGE and RAPD techniques giving 27, 26 and 25 unique types, respectively. The results showed that the PCR MP technique has at least the same discriminatory power as REA-PFGE and RAPD. Conclusion Data presented here show for the first time the evaluation of PCR MP technique for candidial strains differentiation and we propose that this can be used as a relatively simple and cheap technique for epidemiological studies in short period of time in hospital.

  7. Fluorinated Phenylalanine Precursor Resistance in Yeast

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    Ian S. Murdoch

    2018-06-01

    Full Text Available Development of a counter-selection method for phenylalanine auxotrophy could be a useful tool in the repertoire of yeast genetics. Fluorinated and sulfurated precursors of phenylalanine were tested for toxicity in Saccharomyces cerevisiae. One such precursor, 4-fluorophenylpyruvate (FPP, was found to be toxic to several strains from the Saccharomyces and Candida genera. Toxicity was partially dependent on ARO8 and ARO9, and correlated with a strain’s ability to convert FPP into 4-fluorophenylalanine (FPA. Thus, strains with deletions in ARO8 and ARO9, having a mild phenylalanine auxotrophy, could be separated from a culture of wild-type strains using FPP. Tetrad analysis suggests FPP resistance in one strain is due to two genes. Strains resistant to FPA have previously been shown to exhibit increased phenylethanol production. However, FPP resistant isolates did not follow this trend. These results suggest that FPP could effectively be used for counter-selection but not for enhanced phenylethanol production.

  8. The impact of different ale brewer’s yeast strains on the proteome of immature beer

    DEFF Research Database (Denmark)

    Berner, Torben Sune; Jacobsen, Susanne; Arneborg, Nils

    2013-01-01

    BACKGROUND: It is well known that brewer’s yeast affects the taste and aroma of beer. However, the influence of brewer’s yeast on the protein composition of beer is currently unknown. In this study, changes of the proteome of immature beer, i.e. beer that has not been matured after fermentation......, by ale brewer’s yeast strains with different abilities to degrade fermentable sugars were investigated. RESULTS: Beers were fermented from standard hopped wort (13° Plato) using two ale brewer’s yeast (Saccharomyces cerevisiae) strains with different attenuation degrees. Both immature beers had the same....... These three proteins, all derived from yeast, were identified as cell wall associated proteins, that is Exg1 (an exo-β-1,3-glucanase), Bgl2 (an endo-β-1,2-glucanase), and Uth1 (a cell wall biogenesis protein). CONCLUSION: Yeast strain dependent changes in the immature beer proteome were identified, i.e. Bgl2...

  9. Selection of yeast starter culture strains for the production of marula fruit wines and distillates.

    Science.gov (United States)

    Fundira, M; Blom, M; Pretorius, I S; van Rensburg, P

    2002-03-13

    Juice of the Sclerocarya birrea subsp. caffra (marula) fruit was fermented by indigenous microflora and different commercial Saccharomyces cerevisiae yeast strains at different temperatures, namely, 15 and 30 degrees C. Volatile acids, esters, and higher alcohols were quantified in the wine and distillates, and the results were interpreted using a multivariate analysis of variance and an average linkage cluster analysis. Significant differences between 15 and 30 degrees C and also among yeasts with respect to volatile compounds were observed. Yeast strains VIN7 and FC consistently produced wines and final distillates significantly different from the other strains. A panel of tasters and marula and brandy producers was asked to select wines and distillates that had an acceptable and typical marula "nose". They were also asked to detect the differences among wines and distillates fermented with the same yeast strain at different temperatures.

  10. Yeast species associated with wine grapes in China.

    Science.gov (United States)

    Li, Shuang-Shi; Cheng, Chao; Li, Zheng; Chen, Jing-Yu; Yan, Bin; Han, Bei-Zhong; Reeves, Malcolm

    2010-03-31

    Having more information on the yeast ecology of grapes is important for wine-makers to produce wine with high quality and typical attributes. China is a significant wine-consuming country and is becoming a serious wine-producer, but little has been reported about the yeast ecology of local ecosystems. This study provides the first step towards the exploitation of the yeast wealth in China's vine-growing regions. The aim of this study was to investigate the yeast population density and diversity on three grape varieties cultivated in four representative vine-growing regions of China. Yeast species diversity was evaluated by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequence analysis of the 5.8S internal transcribed spacer (ITS) ribosomal DNA (rDNA) region of cultivable yeasts. The grapes harbored yeast populations at 10(2)-10(6)CFU/mL, consisting mostly of non-Saccharomyces species. Seventeen different yeast species belonging to eight genera were detected on the grape samples tested, including Hanseniaspora uvarum, Cryptococcus flavescens, Pichia fermentans, Candida zemplinina, Cryptococcus carnescens, Candida inconpicua, Zygosaccharomyces fermentati, Issatchenkia terricola, Candida quercitrusa, Hanseniaspora guilliermondii, Candida bombi, Zygosaccharomyces bailii, Sporidiobolus pararoseus, Cryptococcus magnus, Metschnikowia pulcherrima, Issatchenkia orientalis and Pichia guilliermondii. H. uvarum and C. flavescens were the dominant species present on the grapes. For the first time Sporidiobolus pararoseus was discovered as an inhabitant of the grape ecosystem. The yeast community on grape berries was influenced by the grape chemical composition, vine-variety and vine-growing region. This study is the first to identify the yeast communities associated with grapes in China using molecular methods. The results enrich our knowledge of wine-related microorganisms, and can be used to promote the development of the local wine

  11. Multiple Origins of the Pathogenic Yeast Candida orthopsilosis by Separate Hybridizations between Two Parental Species.

    Science.gov (United States)

    Schröder, Markus S; Martinez de San Vicente, Kontxi; Prandini, Tâmara H R; Hammel, Stephen; Higgins, Desmond G; Bagagli, Eduardo; Wolfe, Kenneth H; Butler, Geraldine

    2016-11-01

    Mating between different species produces hybrids that are usually asexual and stuck as diploids, but can also lead to the formation of new species. Here, we report the genome sequences of 27 isolates of the pathogenic yeast Candida orthopsilosis. We find that most isolates are diploid hybrids, products of mating between two unknown parental species (A and B) that are 5% divergent in sequence. Isolates vary greatly in the extent of homogenization between A and B, making their genomes a mosaic of highly heterozygous regions interspersed with homozygous regions. Separate phylogenetic analyses of SNPs in the A- and B-derived portions of the genome produces almost identical trees of the isolates with four major clades. However, the presence of two mutually exclusive genotype combinations at the mating type locus, and recombinant mitochondrial genomes diagnostic of inter-clade mating, shows that the species C. orthopsilosis does not have a single evolutionary origin but was created at least four times by separate interspecies hybridizations between parents A and B. Older hybrids have lost more heterozygosity. We also identify two isolates with homozygous genomes derived exclusively from parent A, which are pure non-hybrid strains. The parallel emergence of the same hybrid species from multiple independent hybridization events is common in plant evolution, but is much less documented in pathogenic fungi.

  12. Multiple Origins of the Pathogenic Yeast Candida orthopsilosis by Separate Hybridizations between Two Parental Species.

    Directory of Open Access Journals (Sweden)

    Markus S Schröder

    2016-11-01

    Full Text Available Mating between different species produces hybrids that are usually asexual and stuck as diploids, but can also lead to the formation of new species. Here, we report the genome sequences of 27 isolates of the pathogenic yeast Candida orthopsilosis. We find that most isolates are diploid hybrids, products of mating between two unknown parental species (A and B that are 5% divergent in sequence. Isolates vary greatly in the extent of homogenization between A and B, making their genomes a mosaic of highly heterozygous regions interspersed with homozygous regions. Separate phylogenetic analyses of SNPs in the A- and B-derived portions of the genome produces almost identical trees of the isolates with four major clades. However, the presence of two mutually exclusive genotype combinations at the mating type locus, and recombinant mitochondrial genomes diagnostic of inter-clade mating, shows that the species C. orthopsilosis does not have a single evolutionary origin but was created at least four times by separate interspecies hybridizations between parents A and B. Older hybrids have lost more heterozygosity. We also identify two isolates with homozygous genomes derived exclusively from parent A, which are pure non-hybrid strains. The parallel emergence of the same hybrid species from multiple independent hybridization events is common in plant evolution, but is much less documented in pathogenic fungi.

  13. [Identification of Candida dubliniensis strains using heat tolerance tests, morphological characteristics and molecular methods].

    Science.gov (United States)

    Arikan, Sevtap; Darka, Ozge; Hasçelik, Gülşen; Günalp, Ayfer

    2003-01-01

    Described in 1995, Candida dubliniensis is a novel Candida species closely related to Candida albicans due primarily to its ability to produce germ tube and chlamydospores. Given these phenotypic similarities between the two species, C. dubliniensis cannot be readily distinguished from Candida albicans by routine laboratory work-up. We explored the frequency of isolation of C. dubliniensis among 213 strains previously defined as C. albicans based on their ability to produce germ tube. The test isolates were initially examined for their morphological features on cornmeal tween 80 agar, inability to grow at 45 degrees C, and the biochemical assimilation profile (ID 32C system, bioMerieux, France). Among all, 2 (0.9%) of the isolates were identified as C. dubliniensis based on the production of numerous chlamydospores in chains on cornmeal tween 80 agar and the lack of growth at 45 degrees C. The assimilation profile of these isolates was found to be in accordance with this identification. In an effort to confirm the identification, polymerase chain reaction (PCR) studies were carried out by using the C. dubliniensis specific primer set, DUBF and DUBR. Both of the isolates yielded C. dubliniensis-specific 288 base pair amplification products, confirming the previous identification obtained with the initial screening tests. The isolates were found to be susceptible to fluconazole and itraconazole, and generated amphotericin B minimal inhibitory concentrations of 0.5-1 microgram/ml by NCCLS M27-A2 microdilution method. These data suggest that the isolation rate of C. dubliniensis among our clinical isolates is low. The morphological features on cornmeal tween 80 agar and the lack of ability to grow at 45 degrees C appear as reliable, cheap, and practical screening tests in initial identification of C. dubliniensis among germ tube-producing Candida strains.

  14. CHARACTERIZATION OF THE ALKANE-INDUCIBLE CYTOCHROME P450 (P450ALK) GENE FROM THE YEAST CANDIDA TROPICALIS: IDENTIFICATION OF A NEW P450 FAMILY

    Science.gov (United States)

    The P450alk gene, which is inducible by the assimilation of alkane in Candida tropicalis, was sequenced and characterized. Structural features described in promoter and terminator regions of Saccharomyces yeast genes are present in the P450alk gene and some particular structures ...

  15. Candida glabrata olecranon bursitis treated with bursectomy and intravenous caspofungin.

    Science.gov (United States)

    Skedros, John G; Keenan, Kendra E; Trachtenberg, Joel D

    2013-01-01

    Orthopedic surgeons are becoming more involved in the care of patients with septic arthritis and bursitis caused by yeast species. This case report involves a middle-aged immunocompromised female who developed a Candida glabrata septic olecranon bursitis that developed after she received a corticosteroid injection in the olecranon bursa for presumed aseptic bursitis. Candida (Torulopsis) glabrata is the second most frequently isolated Candida species from the bloodstream in the United States. Increased use of fluconazole and other azole antifungal agents as a prophylactic treatment for recurrent Candida albicans infections in immunocompromised individuals is one reason why there appears to be increased resistance of C. glabrata and other nonalbicans Candida (NAC) species to fluconazole. In this patient, this infection was treated with surgery (bursectomy) and intravenous caspofungin, an echinocandin. This rare infectious etiology coupled with this intravenous antifungal treatment makes this case novel among cases of olecranon bursitis caused by yeasts.

  16. Induction and inhibition of film yeast from fermented bamboo shoot by seasoning plants

    Directory of Open Access Journals (Sweden)

    Jaruwan Maneesri

    2007-07-01

    Full Text Available Three samples of fermented bamboo shoot taken from a village in Amphur Kokpho, Pattani Province, were microbiologically examined. Total viable count was between at 104-105 cfu/ml while pH range was between 3.4-4.4. Isolation and identification of film yeast on surface of fermented liquid revealed Saccharomyces cerevisiae J1, Candida krusei J2 and Candida krusei J3. When film yeast was cultivated in liquid culture with different NaCl concentrations (0, 2.5, 5 and 7.5% (w/v, all species tolerated 2.5% NaCl addition. However, growth decreased depending on NaCl concentration. S. cerevisiae J1 grew faster than C. krusei J2 and C. krusei J3. The cultivation of film yeast in medium with different agar concentrations (0.3, 0.5, 1 and 1.5% (w/v within 24 h showed that 0.3% was the optimal agar concentration. Seasoning plants (garlic, ginger, galangal, lemon grass, lesser galangal, clove, kaffir lime, garcinia and shallot were extracted with water (3% (w/v and tested for growth inhibition. Results showed the clove extract inhibited all yeast strains within 12 h and after that the efficiency of inhibition was decreased. At low concentration of 0.75% (w/v clove extract could inhibit film yeast in fermented bamboo shoot.

  17. High prevalence of oral colonization by Candida dubliniensis in HIV-positive patients in Argentina.

    Science.gov (United States)

    Binolfi, Andrés; Biasoli, Marisa S; Luque, Alicia G; Tosello, María E; Magaró, Hortensia M

    2005-08-01

    Candida dubliniensis is a recently described yeast species, closely related to Candida albicans. This work represents the first general survey of the carriage of C. dubliniensis in the oral cavities of HIV-positive patients in Argentina. We studied 133 strains isolated from 162 HIV-positive patients, using the following identification tests: chlamydospore production on corn meal agar with Tween 80; colony color on CHROMagar Candida media; differential growth at 45 degrees C on potato dextrose agar; D-xylose assimilation; chlamydospore formation on sunflower seed agar (SSA); carbohydrate assimilation profiles using the API 20 C Aux commercial kit and PCR using primers that hybridize to the class IV intron of the ACT1 gene. Out of the 133 strains, 21 were identified as C. dubliniensis, representing approximately 13% of the 162 patients in this study. From these data, we conclude that although the PCR assay is the most reliable method, clamydospore formation on SSA is an easier and less expensive test for the screening of C. dubliniensis in the routine laboratory. Our results show that C. dubliniensis has a high prevalence among HIV-positive patients in Argentina.

  18. Ecological structuring of yeasts associated with trees around Hamilton, Ontario, Canada.

    Science.gov (United States)

    Maganti, Harinad; Bartfai, David; Xu, Jianping

    2012-02-01

    This study seeks to determine the distribution and diversity of yeasts in and around the Hamilton area in Canada. In light of the increasing number of fungal infections along with rising morbidity and mortality rates, especially among the immunocompromised, understanding the diversity and distribution of yeasts in natural environments close to human habitations has become an increasingly relevant topic. In this study, we analyzed 1110 samples obtained from the hollows of trees, shrubs and avian droppings at 8 geographical sites in and around Hamilton, Ontario, Canada. A total of 88 positive yeast strains were isolated and identified belonging to 20 yeast species. Despite the relative proximity of the sampling sites, our DNA fingerprinting results showed that the yeast populations were highly heterogenous. Among the 14 tree species sampled, cedar, cottonwood and basswood hollows had relatively high yeast colonization rates. Interestingly, Candida parapsilosis was isolated almost exclusively from Pine trees only. Our results are consistent with microgeographic and ecological differentiation of yeast species in and around an urban environment. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  19. Incidence and Speciation of Candida Species among Non-gravid ...

    African Journals Online (AJOL)

    This study investigated the incidence and speciation of Candida species among non-gravid young females, using commercially available chromogenic Candida speciation media (CHROM agar) for the identification/speciation of medically important yeast and yeastlike organisms in a routine clinical mycology laboratory.

  20. Psidium guajava L. and Psidium brownianum Mart ex DC.: Chemical composition and anti - Candida effect in association with fluconazole.

    Science.gov (United States)

    Morais-Braga, Maria Flaviana B; Sales, Débora L; Carneiro, Joara Nalyda P; Machado, Antonio Júdson T; Dos Santos, Antonia Thassya L; de Freitas, Maria Audilene; Martins, Gioconda Morais de A Bezerra; Leite, Nadghia Figueiredo; de Matos, Yedda Maria L S; Tintino, Saulo R; Souza, Djair S L; Menezes, Irwin R A; Ribeiro-Filho, Jaime; Costa, José G M; Coutinho, Henrique D M

    2016-06-01

    The therapeutic combinations have been increasingly used against fungal resistance. Natural products have been evaluated in combination with pharmaceutical drugs in the search for new components able to work together in order to neutralize the multiple resistance mechanisms found in yeasts from the genus Candida. The aqueous and hydroethanolic extracts from Psidium brownianum Mart ex DC. and Psidium guajava L. species were evaluated for their potential to change the effect of commercial pharmaceutical drugs against Candida albicans and Candida tropicalis strains. The tests were performed according to the broth microdilution method. Plate readings were carried out by spectrophotometry, and the data generated the cell viability curve and IC50 of the extracts against the yeasts. A chemical analysis of all the extracts was performed for detection and characterization of the secondary metabolites. The total phenols were quantified in gallic acid eq/g of extract (GAE/g) and the phenolic composition of the extracts was determined by HPLC. Fluconazole and all extracts presented high Minimum Inhibitories Concentrations (MICs). However, when associated with the extracts at sub-inhibitory concentrations (MIC/16), fluconazole had its effect potentiated. A synergistic effect was observed in the combination of fluconazole with Psidium brownianum extracts against all Candida strains. However, for Psidium guajava extracts the synergistic effect was produced mainly against the Candida albicans LM77 and Candida tropicalis INCQS 400042 strains. The IC50 values of fluconazole ranged from 19.22 to 68.1 μg/mL when it was used alone, but from 2.2 to 45.4 μg/mL in the presence of the extracts. The qualitative chemical characterization demonstrated the presence of phenols, flavonoids and tannins among the secondary metabolites. The concentration of total phenols ranged from 49.25 to 80.77 GAE/g in the P. brownianum extracts and from 68.06 to 82.18 GAE/g in the P. guajava extracts

  1. Genetic and phenotypic diversity of autochthonous cider yeasts in a cellar from Asturias.

    Science.gov (United States)

    Pando Bedriñana, R; Querol Simón, A; Suárez Valles, B

    2010-06-01

    This paper analyses yeast diversity and dynamics during the production of Asturian cider. Yeasts were isolated from apple juice and at different stages of fermentation in a cellar in Villaviciosa during two Asturian cider-apple harvests. The species identified by ITS-RFLP corresponded to Hanseniaspora valbyensis, Hanseniaspora uvarum, Metschnikowia pulcherrima, Pichia guilliermondii, Candida parapsilosis, Saccharomyces cerevisiae and Saccharomyces bayanus/Saccharomyces pastorianus/Saccharomyces kudriavzevii/Saccharomyces mikatae. The species C. parapsilosis is reported here for the first time in cider. The analysis of Saccharomyces mtDNA patterns showed great diversity, sequential substitution and the presence of a small number of yeast patterns (up to 8), present in both harvests. Killer (patterns nos. 22' and 47), sensitive (patterns nos. 12, 15, 33 and 61) and neutral phenotypes were found among the S. cerevisiae isolates. The detection of beta-glucosidase activity, with arbutin as the sole carbon source, allowed two S. cerevisiae strains (patterns nos. 3' and 19') to be differentiated by means of this enzymatic activity. Yeast strains producing the killer toxin or with beta-glucosidase activity are reported for the first time in autochthonous cider yeasts. 2009 Elsevier Ltd. All rights reserved.

  2. The Efficacy of Specific Essential Oils on Yeasts Isolated from the Royal Tomb Paintings at Tanis, Egypt

    Directory of Open Access Journals (Sweden)

    Akmal Ali SAKR

    2012-06-01

    Full Text Available Yeast strains play an important role in the biodeterioration and biodegradation of paintings in ancient Egyptian tombs. Thirteen yeast were isolated from the royal tombs at Tanis (Oserkon II, Psunes and Shashanq, Sharkia Governorate, Egypt, dated back to 840 B.C., by using a sterile cotton swab. Those strains were identified as Saccharomyces cerevisiae, Candida albicans, C. lipolytica and Lodderomyces elongspous. The S. cerevisiae strains were halotolerant for sodium chloride, up to 10 %. Moreover, they caused a fading for the azurite blue color in laboratory cultures and S. cerevisiae was the most potent agent in fading the color. Five essential oils (lemon, spearmint, fennel, marjonam and rosemary were used to control their growth. Spearmint and lemon oils were the most effective oils in inhibiting the growth of those strains, whereas marjonam, fennel and rosemary had no effect on their growth.

  3. Yeast cell differentiation: Lessons from pathogenic and non-pathogenic yeasts.

    Science.gov (United States)

    Palková, Zdena; Váchová, Libuše

    2016-09-01

    Yeasts, historically considered to be single-cell organisms, are able to activate different differentiation processes. Individual yeast cells can change their life-styles by processes of phenotypic switching such as the switch from yeast-shaped cells to filamentous cells (pseudohyphae or true hyphae) and the transition among opaque, white and gray cell-types. Yeasts can also create organized multicellular structures such as colonies and biofilms, and the latter are often observed as contaminants on surfaces in industry and medical care and are formed during infections of the human body. Multicellular structures are formed mostly of stationary-phase or slow-growing cells that diversify into specific cell subpopulations that have unique metabolic properties and can fulfill specific tasks. In addition to the development of multiple protective mechanisms, processes of metabolic reprogramming that reflect a changed environment help differentiated individual cells and/or community cell constituents to survive harmful environmental attacks and/or to escape the host immune system. This review aims to provide an overview of differentiation processes so far identified in individual yeast cells as well as in multicellular communities of yeast pathogens of the Candida and Cryptococcus spp. and the Candida albicans close relative, Saccharomyces cerevisiae. Molecular mechanisms and extracellular signals potentially involved in differentiation processes are also briefly mentioned. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Isolation and characterization of yeasts capable of efficient utilization of hemicellulosic hydrolyzate as the carbon source.

    Science.gov (United States)

    Cassa-Barbosa, L A; Procópio, R E L; Matos, I T S R; Filho, S A

    2015-09-28

    Few yeasts have shown the potential to efficiently utilize hemicellulosic hydrolyzate as the carbon source. In this study, microorganisms isolated from the Manaus region in Amazonas, Brazil, were characterized based on their utilization of the pentoses, xylose, and arabinose. The yeasts that showed a potential to assimilate these sugars were selected for the better utilization of lignocellulosic biomass. Two hundred and thirty seven colonies of unicellular microorganisms grown on hemicellulosic hydrolyzate, xylose, arabinose, and yeast nitrogen base selective medium were analyzed. Of these, 231 colonies were subjected to sugar assimilation tests. One hundred and twenty five of these were shown to utilize hydrolyzed hemicellulose, xylose, or arabinose as the carbon source for growth. The colonies that showed the best growth (N = 57) were selected, and their internal transcribed spacer-5.8S rDNA was sequenced. The sequenced strains formed four distinct groups in the phylogenetic tree, and showed a high percentage of similarity with Meyerozyma caribbica, Meyerozyma guilliermondii, Trichosporon mycotoxinivorans, Trichosporon loubieri, Pichia kudriavzevii, Candida lignohabitans, and Candida ethanolica. The discovery of these xylose-fermenting yeasts could attract widespread interest, as these can be used in the cost-effective production of liquid fuel from lignocellulosic materials.

  5. Studies on microbiological treatment and utilization of cane molasses distillery wastes. Part 1. Screening of useful yeast strains

    Energy Technology Data Exchange (ETDEWEB)

    Akaki, M.; Takahashi, T.; Ishiguro, K.

    1981-01-01

    Cane molasses distillation slops were used as substrate for the cultivation of 203 strains of yeast. Most yeast strains, especially Hansenula, Debaryomyces, and Rhodotorula, assimilated the molasses distillation wastes. Yeast cell dry weight reached 0.9 grams/100 mL, and yeasts removed greater than 30% of the COD of the waste material.

  6. Dictyostelium discoideum as a novel host system to study the interaction between phagocytes and yeasts

    Directory of Open Access Journals (Sweden)

    Barbara Koller

    2016-10-01

    Full Text Available The social amoeba Dictyostelium discoideum is a well-established model organism to study the interaction between bacteria and phagocytes. In contrast, research using D. discoideum as a host model for fungi is rare. We describe a comprehensive study, which uses D. discoideum as a host model system to investigate the interaction with apathogenic (Saccharomyces cerevisiae and pathogenic (Candida sp. yeast. We show that Dictyostelium can be co-cultivated with yeasts on solid media, offering a convenient test to study the interaction between fungi and phagocytes. We demonstrate that a number of D. discoideum mutants increase (atg1-, kil1-, kil2- or decrease (atg6- the ability of the amoebae to predate yeast cells. On the yeast side, growth characteristics, reduced phagocytosis rate, as well as known virulence factors of C. albicans (EFG1, CPH1, HGC1, ICL1 contribute to the resistance of yeast cells against predation by the amoebae. Investigating haploid C. albicans strains, we suggest using the amoebae plate test for screening purposes after random mutagenesis. Finally, we discuss the potential of our adapted amoebae plate test to use D. discoideum for risk assessment of yeast strains.

  7. Oral Candida colonization in oral cancer patients and its relationship with traditional risk factors of oral cancer: a matched case-control study.

    Science.gov (United States)

    Alnuaimi, Ali D; Wiesenfeld, David; O'Brien-Simpson, Neil M; Reynolds, Eric C; McCullough, Michael J

    2015-02-01

    Candida, an opportunistic fungal pathogen, has been implicated in oral and oesophageal cancers. This study aimed to examine oral Candida carriage in 52 oral cancer patients and 104 age-, gender- and denture status-matched oral cancer-free subjects. We assessed general health, smoking and alcohol drinking habits, use of alcohol-containing mouthwash and periodontal status (community periodontal index of treatment needs). Yeasts were isolated using oral rinse technique and genetically identified via Real-Time PCR-High resolution melting curve analysis of conserved ribosomal DNA. Conditional and binary logistic regressions were used to identify explanatory variables that are risk factors for oral cancer. The frequencies of oral yeasts' presence and high oral colonization were significantly higher in oral cancer than non-oral cancer patients (p=001; p=0.033, respectively). No significant difference in the isolation profile of Candida species was found between the two groups, except C. parapsilosis was more frequent in non-oral cancer group. Differences were noticed in the incidence of C. albicans strains where significantly more C. albicans genotype-A was isolated from cancer patients and significantly more C. albicans genotype-B isolated from non-cancer patients. Multiple regression analyses showed significant association with cancer observed for alcohol drinking (OR=4.253; 95% CI=1.351, 13.386), Candida presence (OR=3.242; 95% CI=1.505, 6.984) and high oral colonization (OR=3.587; 95% CI=1.153, 11.162). These results indicate that there is a significant association between oral cancer occurrence and Candida oral colonization and that the observed genotypic diversity of C. albicans strains may play a role in oral carcinogenesis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Effect of Agave tequilana age, cultivation field location and yeast strain on tequila fermentation process.

    Science.gov (United States)

    Pinal, L; Cornejo, E; Arellano, M; Herrera, E; Nuñez, L; Arrizon, J; Gschaedler, A

    2009-05-01

    The effect of yeast strain, the agave age and the cultivation field location of agave were evaluated using kinetic parameters and volatile compound production in the tequila fermentation process. Fermentations were carried out with Agave juice obtained from two cultivation fields (CF1 and CF2), as well as two ages (4 and 8 years) and two Saccharomyces cerevisiae yeast strains (GU3 and AR5) isolated from tequila fermentation must. Sugar consumption and ethanol production varied as a function of cultivation field and agave age. The production of ethyl acetate, 1-propanol, isobutanol and amyl alcohols were influenced in varying degrees by yeast strain, agave age and cultivation field. Methanol production was only affected by the agave age and 2-phenylethanol was influenced only by yeast strain. This work showed that the use of younger Agave tequilana for tequila fermentation resulted in differences in sugar consumption, ethanol and volatile compounds production at the end of fermentation, which could affect the sensory quality of the final product.

  9. Nitrile Metabolizing Yeasts

    Science.gov (United States)

    Bhalla, Tek Chand; Sharma, Monica; Sharma, Nitya Nand

    Nitriles and amides are widely distributed in the biotic and abiotic components of our ecosystem. Nitrile form an important group of organic compounds which find their applications in the synthesis of a large number of compounds used as/in pharmaceutical, cosmetics, plastics, dyes, etc>. Nitriles are mainly hydro-lyzed to corresponding amide/acid in organic chemistry. Industrial and agricultural activities have also lead to release of nitriles and amides into the environment and some of them pose threat to human health. Biocatalysis and biotransformations are increasingly replacing chemical routes of synthesis in organic chemistry as a part of ‘green chemistry’. Nitrile metabolizing organisms or enzymes thus has assumed greater significance in all these years to convert nitriles to amides/ acids. The nitrile metabolizing enzymes are widely present in bacteria, fungi and yeasts. Yeasts metabolize nitriles through nitrilase and/or nitrile hydratase and amidase enzymes. Only few yeasts have been reported to possess aldoxime dehydratase. More than sixty nitrile metabolizing yeast strains have been hither to isolated from cyanide treatment bioreactor, fermented foods and soil. Most of the yeasts contain nitrile hydratase-amidase system for metabolizing nitriles. Transformations of nitriles to amides/acids have been carried out with free and immobilized yeast cells. The nitrilases of Torulopsis candida>and Exophiala oligosperma>R1 are enantioselec-tive and regiospecific respectively. Geotrichum>sp. JR1 grows in the presence of 2M acetonitrile and may have potential for application in bioremediation of nitrile contaminated soil/water. The nitrilase of E. oligosperma>R1 being active at low pH (3-6) has shown promise for the hydroxy acids. Immobilized yeast cells hydrolyze some additional nitriles in comparison to free cells. It is expected that more focus in future will be on purification, characterization, cloning, expression and immobilization of nitrile metabolizing

  10. Comparison of the identification results of Candida species obtained by BD Phoenix™ and Maldi-TOF (Bruker Microflex LT Biotyper 3.1).

    Science.gov (United States)

    Marucco, Andrea P; Minervini, Patricia; Snitman, Gabriela V; Sorge, Adriana; Guelfand, Liliana I; Moral, Laura López

    2018-02-05

    In patients with invasive fungal infections, the accurate and rapid identification of the genus Candida is of utmost importance since antimycotic sensitivity is closely related to the species. The aim of the present study was to compare the identification results of species of the genus Candida obtained by BD Phoenix™ (Becton Dickinson [BD]) and Maldi-TOF MS (Bruker Microflex LT Biotyper 3.1). A total of 192 isolates from the strain collection belonging to the Mycology Network of the Autonomous City of Buenos Aires, Argentina, were analyzed. The observed concordance was 95%. Only 10 strains (5%) were not correctly identified by the BD Phoenix™ system. The average identification time with the Yeast ID panels was 8h 22min. The BD Phoenix™ system proved to be a simple, reliable and effective method for identifying the main species of the genus Candida. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  11. Occurrence and identification of yeast species in fermented liquid feed for piglets

    DEFF Research Database (Denmark)

    Gori, Klaus; Bjørklund, Marina Kryger; Canibe, Nuria

    2011-01-01

    The major objective of the present study was to investigate the occurrence and identity of yeast species in fermented liquid feed (FLF) used for feeding piglets. In total, 40 different Danish farms were included in the analysis. The preparation and composition of FLF was found to be very...... heterogeneous with high variations in both yeast counts and yeast species composition. The yeast population varied between 6.0 × 10(3) and 4.2 × 10(7) cfug(-1) with an average yeast count of 8.7 × 10(6) ± 1.1 × 10(7) cfug(-1). A total of 766 yeasts were isolated and identified by conventional and/or molecular...... typing techniques. The predominant yeast species in the FLF samples were found to be Candida milleri (58.4%), Kazachstania exigua (17.5%), Candida pararugosa (6.40%) and Kazachstania bulderi (5.09%). No clear separation between isolates of C. milleri and Candida humilis could be obtained based...

  12. Study of the role of the covalently linked cell wall protein (Ccw14p) and yeast glycoprotein (Ygp1p) within biofilm formation in a flor yeast strain.

    Science.gov (United States)

    Moreno-García, J; Coi, A L; Zara, G; García-Martínez, T; Mauricio, J C; Budroni, M

    2018-03-01

    Flor yeasts are Saccharomyces cerevisiae strains noted by their ability to create a type of biofilm in the air-liquid interface of some wines, known as 'flor' or 'velum', for which certain proteins play an essential role. Following a proteomic study of a flor yeast strain, we deleted the CCW14 (covalently linked cell wall protein) and YGP1 (yeast glycoprotein) genes-codifying for two cell surface glycoproteins-in a haploid flor yeast strain and we reported that both influence the weight of the biofilm as well as cell adherence (CCW14).

  13. Screening of native yeast from Agave duranguensis fermentation for isoamyl acetate production

    Directory of Open Access Journals (Sweden)

    Gerardo Hernández-Carbajal

    2013-06-01

    Full Text Available In this work, fifty yeast strains, isolated from the spontaneous alcoholic fermentation of Agave duranguensis to produce mezcal, were tested using the double coupling system. These yeasts were from the genera Pichia, Torulaspora, Saccharomyces, Kluyveromyces, Deckera, Hanseniaspora, and Candida. P. fermentans ITD00165 was the best isoamyl acetate producer, yielding 0.38 g/L of ester after incubation for 24 h, while K. marxianus ITD00211 produced 0.32 g/L of ester. Thus P. fermentans TD00165 could be considered as an excellent choice for use in optimization studies of the culture medium and bioreactor operating conditions to develop a process for biotechnological production of isoamyl acetate.

  14. Identification and enzymatic characterization of the yeasts isolated from Erzincan tulum cheese

    Directory of Open Access Journals (Sweden)

    S. Karasu-Yalcin

    2012-03-01

    Full Text Available In this study, 146 yeast isolates were obtained from 45 Erzincan tulum cheese samples. By using API ID 32C test system and some complementary morphological, physiological and biochemica tests, 121 of the isolates could be identified at species level, while 12 of them were identified at genus level. The identified yeast isolates belonged to six different genera which were Candida, Geotrichum, Kluyveromyces, Pichia, Saccharomyces and Zygosaccharomyces. The most aboundant species was C. lambica, followed by C. zeylanoides, C. famata var. famata, G. candidum and C. kefyr. Enzymatic characterization of the strains was determined by using API-ZYM test system. All of the isolates had leucin arylamidase activity. Eight strains belonging to S. cerevisiae, Z. mellis, G. candidum and P. fermentans were found to have high leucin arylamidase activities. Most of the isolates had β-galactosidase, acid phosphatase and esterase lipase (C8 activities. Eight investigated C. lambica strains had high acid phosphatase activities. Such enzymatic properties of investigated yeast isolates could be fundamental factor for their application as starter culture candidates in production of Erzincan tulum cheese. It was demonstrated that the strain C. lambica T103 had superior enzymatic characteristics with the potential to be used in further technological investigations as an adjunct starter.

  15. Reversal of fluconazole resistance induced by a synergistic effect with Acca sellowiana in Candida glabrata strains.

    Science.gov (United States)

    R M Machado, Gabriella da; Pippi, Bruna; Dalla Lana, Daiane Flores; Amaral, Ana Paula S; Teixeira, Mário Lettieri; Souza, Kellen C B de; Fuentefria, Alexandre M

    2016-11-01

    The increased incidence of non-albicans Candida (NAC) resistant to fluconazole (FLZ) makes it necessary to use new therapeutic alternatives. Acca sellowiana (O.berg) Burret (Myrtaceae) is a guava with several proven biological activities. The interaction with fluconazole can be a feasible alternative to overcome this resistance. This study evaluates the in vitro antifungal activity of fractions obtained from the lyophilized aqueous extract of the leaves of A. sellowiana against resistant strains of NAC. The antifungal activity of the fractions was evaluated at 500 μg/mL by microdilution method. Checkerboard assay was performed to determine the effect of the combination of the F2 fraction and antifungal at concentrations: MIC/4, MIC/2, MIC, MIC × 2 and MIC × 4. Candida glabrata showed the lowest MIC values (500-3.90 μg/mL) and the F2 active fraction was the most effective. The association of F2 with FLZ showed a strong synergistic effect (FICI ≤ 0.5) against 100% of C. glabrata resistant isolates. Moreover, the F2 active fraction has demonstrated that probably acts in the cell wall of these yeasts. There was no observed acute dermal toxicity of lyophilized aqueous extract of leaves of A. sellowiana on pig ear skin cells. The interaction between substances present in the F2 active fraction is possibly responsible for the antifungal activity presented by this fraction. This study is unprecedented and suggests that the combination of F2 active fraction and FLZ might be used as an alternative treatment for mucocutaneus infections caused by C. glabrata resistant.

  16. Molecular and biochemical studies of some yeast strains

    African Journals Online (AJOL)

    user

    2011-02-21

    Feb 21, 2011 ... Kluyveromyces lactis (Y.9) and Pichia jadinii (Y.10) contained almost double the amount of total amino ... Differences between ... biochemical analysis (total protein profile and total amino acids) were used as tools to select the best yeast strains in Saudi Arabia and Egypt as a rich source of animal protein.

  17. The Effect of Aqueous and Ethanolic Extracts of Teucrium polium on Candida Albicans and Two Species of Malassezia

    Directory of Open Access Journals (Sweden)

    Maryam Nadimi

    2013-08-01

    Full Text Available Background: Teucrium polium L. is a medicinal plant, which due to its antimicrobial, antispasmodic and anti-tumor properties has been used in traditional medicine for over 2000 years. The aim of this research was to study the effect of aqueous and ethanolic extracts of Teucrium polium L. against three strains of Candida albicans (ATCC 62061, ATCC 1677, and NCPF 3153, Malassezia furfur and Malassezia globosa using pour plate method. Materials and Methods: Teucrium polium L. was collected from Broojen area during the spring. The plant was dried and powdered. The aqueous and ethanolic extracts were prepared from the fine powder. Different concentrations of extracts (1, 2, 4, and 8 mg/ml were made in Sabouraud Dextrose Agar (SDA and modified Leeming-Notman Agar (MLNA medium for Candida albicans, Malassezia furfur and Malassezia globosa. 1.5×106 cfu/ml of yeasts, were cultured on media and incubated at 37ºC and 32ºC respectively. Pour plate method was used to assess the antifungal activity of these extracts.Results: The inhibitory effect of ethanolic extract of Teucrium polium L. on the three strains of Candida albicans was depended on concentration level of extracts in media. Aqueous extract had inhibitory effect on Candida albicans (NCPF 3153 only, and with increasing of the extract concentration, the number of colonies was decreased, so that in concentration of 8 mg/ml, no growth was seen. Aqueous and ethanolic extracts had no inhibitory effect on Malassezia species. Conclusion: Teucrium polium L. extracts have considerable inhibitory effect on different strains of Candida albicans. Further investigations are needed to detect the effectiveness of this plant in treatment of Candida infections.

  18. Relationship of trehalose accumulation with ethanol fermentation in industrial Saccharomyces cerevisiae yeast strains.

    Science.gov (United States)

    Wang, Pin-Mei; Zheng, Dao-Qiong; Chi, Xiao-Qin; Li, Ou; Qian, Chao-Dong; Liu, Tian-Zhe; Zhang, Xiao-Yang; Du, Feng-Guang; Sun, Pei-Yong; Qu, Ai-Min; Wu, Xue-Chang

    2014-01-01

    The protective effect and the mechanisms of trehalose accumulation in industrial Saccharomyces cerevisiae strains were investigated during ethanol fermentation. The engineered strains with more intercellular trehalose achieved significantly higher fermentation rates and ethanol yields than their wild strain ZS during very high gravity (VHG) fermentation, while their performances were not different during regular fermentation. The VHG fermentation performances of these strains were consistent with their growth capacity under osmotic stress and ethanol stress, the key stress factors during VHG fermentation. These results suggest that trehalose accumulation is more important for VHG fermentation of industrial yeast strains than regular one. The differences in membrane integrity and antioxidative capacity of these strains indicated the possible mechanisms of trehalose as a protectant under VHG condition. Therefore, trehalose metabolic engineering may be a useful strategy for improving the VHG fermentation performance of industrial yeast strains. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Novel endophytic yeast Rhodotorula mucilaginosa strain PTD3 I: production of xylitol and ethanol.

    Science.gov (United States)

    Bura, Renata; Vajzovic, Azra; Doty, Sharon L

    2012-07-01

    An endophytic yeast, Rhodotorula mucilaginosa strain PTD3, that was isolated from stems of hybrid poplar was found to be capable of production of xylitol from xylose, of ethanol from glucose, galactose, and mannose, and of arabitol from arabinose. The utilization of 30 g/L of each of the five sugars during fermentation by PTD3 was studied in liquid batch cultures. Glucose-acclimated PTD3 produced enhanced yields of xylitol (67% of theoretical yield) from xylose and of ethanol (84, 86, and 94% of theoretical yield, respectively) from glucose, galactose, and mannose. Additionally, this yeast was capable of metabolizing high concentrations of mixed sugars (150 g/L), with high yields of xylitol (61% of theoretical yield) and ethanol (83% of theoretical yield). A 1:1 glucose:xylose ratio with 30 g/L of each during double sugar fermentation did not affect PTD3's ability to produce high yields of xylitol (65% of theoretical yield) and ethanol (92% of theoretical yield). Surprisingly, the highest yields of xylitol (76% of theoretical yield) and ethanol (100% of theoretical yield) were observed during fermentation of sugars present in the lignocellulosic hydrolysate obtained after steam pretreatment of a mixture of hybrid poplar and Douglas fir. PTD3 demonstrated an exceptional ability to ferment the hydrolysate, overcome hexose repression of xylose utilization with a short lag period of 10 h, and tolerate sugar degradation products. In direct comparison, PTD3 had higher xylitol yields from the mixed sugar hydrolysate compared with the widely studied and used xylitol producer Candida guilliermondii.

  20. Genome sequence of the oleaginous yeast Rhodotorula toruloides strain CGMCC 2.1609

    Directory of Open Access Journals (Sweden)

    Christine Sambles

    2017-09-01

    Full Text Available Most eukaryotic oleaginous species are yeasts and among them the basidiomycete red yeast, Rhodotorula (Rhodosporidium toruloides (Pucciniomycotina is known to produce high quantities of lipids when grown in nitrogen-limiting media, and has potential for biodiesel production. The genome of the CGMCC 2.1609 strain of this oleaginous red yeast was sequenced using a hybrid of Roche 454 and Illumina technology generating 13× coverage. The de novo assembly was carried out using MIRA and scaffolded using MAQ and BAMBUS. The sequencing and assembly resulted in 365 scaffolds with total genome size of 33.4 Mb. The complete genome sequence of this strain was deposited in GenBank and the accession number is LKER00000000. The annotation is available on Figshare (doi:10.6084/m9.figshare.4754251.

  1. Antifungal activity of the lemongrass oil and citral against Candida spp.

    Directory of Open Access Journals (Sweden)

    Cristiane de Bona da Silva

    Full Text Available Superficial mycoses of the skin are among the most common dermatological infections, and causative organisms include dermatophytic, yeasts, and non-dermatophytic filamentous fungi. The treatment is limited, for many reasons, and new drugs are necessary. Numerous essential oils have been tested for both in vitro and in vivo antifungal activity and some pose much potential as antifungal agents. By using disk diffusion assay, we evaluated the antifungal activity of lemongrass oil and citral against yeasts of Candida species (Candida albicans, C. glabrata, C. krusei, C. parapsilosis and C. tropicalis. This study showed that lemongrass oil and citral have a potent in vitro activity against Candida spp.

  2. Starmerella syriaca f.a., sp. nov., an osmotolerant yeast species isolated from flowers in Syria.

    Science.gov (United States)

    Sipiczki, Matthias

    2015-04-01

    Four strains of a novel asexual ascomycetous yeast species were isolated from Malva sp. flowers in Syria. Sequencing of the regions spanning the small subunit, 5.8S, and the D1/D2 domains of the large subunit ribosomal RNA genes showed that the isolates were conspecific. Comparative analysis of these sequences and the corresponding sequences of the type strains of ascomycetous yeasts revealed that the novel species is phylogenetically related to members of the Starmerella clade. Its closest relative is Candida vaccinii. For the new species the name Starmerella syriaca is proposed. Its strains are osmotolerant and produce pseudohypha-like structures capable of penetrating agar media. The type strain is 2-1362(T) (=CBS 13909(T) = NCAIM Y.02138(T) = CCY 090-003-001(T)). The GenBank accession numbers for its nucleotide sequences are: JX515986 (D1/D2 LSU), JX515987 (ITS1-5.8S-ITS2) and JX515988 (SSU). Mycobank: MB 810090.

  3. Candidacidal Activity of a Novel Killer Toxin from Wickerhamomyces anomalus against Fluconazole-Susceptible and -Resistant Strains

    Directory of Open Access Journals (Sweden)

    Laura Giovati

    2018-02-01

    Full Text Available The isolation and characterization from the sand fly Phlebotomus perniciosus of a Wickerhamomyces anomalus yeast strain (Wa1F1 displaying the killer phenotype was recently reported. In the present work, the killer toxin (KT produced by Wa1F1 was purified and characterized, and its antimicrobial activity in vitro was investigated against fluconazole- susceptible and -resistant clinical isolates and laboratory strains of Candida albicans and C. glabrata displaying known mutations. Wa1F1-KT showed a differential killing ability against different mutant strains of the same species. The results may be useful for the design of therapeutic molecules based on Wa1F1-KT and the study of yeast resistance mechanisms.

  4. Essential Oil of Cymbopogon nardus (L. Rendle: A Strategy to Combat Fungal Infections Caused by Candida Species

    Directory of Open Access Journals (Sweden)

    Luciani Gaspar De Toledo

    2016-08-01

    Full Text Available Background: The incidence of fungal infections, especially those caused by Candida yeasts, has increased over the last two decades. However, the indicated therapy for fungal control has limitations. Hence, medicinal plants have emerged as an alternative in the search for new antifungal agents as they present compounds, such as essential oils, with important biological effects. Published data demonstrate important pharmacological properties of the essential oil of Cymbopogon nardus (L. Rendle; these include anti-tumor, anti-nociceptive, and antibacterial activities, and so an investigation of this compound against pathogenic fungi is interesting. Objective: The aim of this study was to evaluate the chemical composition and biological potential of essential oil (EO obtained from the leaves of C. nardus focusing on its antifungal profile against Candida species. Methods: The EO was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS. Testing of the antifungal potential against standard and clinical strains was performed by determining the minimal inhibitory concentration (MIC, time-kill, inhibition of Candida albicans hyphae growth, and inhibition of mature biofilms. Additionally, the cytotoxicity was investigated by the IC50 against HepG-2 (hepatic and MRC-5 (fibroblast cell lines. Results: According to the chemical analysis, the main compounds of the EO were the oxygen-containing monoterpenes: citronellal, geranial, geraniol, citronellol, and neral. The results showed important antifungal potential for all strains tested with MIC values ranging from 250 to 1000 μg/mL, except for two clinical isolates of C. tropicalis (MIC > 1000 μg/mL. The time-kill assay showed that the EO inhibited the growth of the yeast and inhibited hyphal formation of C. albicans strains at concentrations ranging from 15.8 to 1000 μg/mL. Inhibition of mature biofilms of strains of C. albicans, C. krusei and C. parapsilosis occurred

  5. Isolation of Vaginal Lactobacilli and Characterization of Anti-Candida Activity.

    Directory of Open Access Journals (Sweden)

    Carola Parolin

    Full Text Available Healthy vaginal microbiota is dominated by Lactobacillus spp., which form a critical line of defence against pathogens, including Candida spp. The present study aims to identify vaginal lactobacilli exerting in vitro activity against Candida spp. and to characterize their antifungal mechanisms of action. Lactobacillus strains were isolated from vaginal swabs of healthy premenopausal women. The isolates were taxonomically identified to species level (L. crispatus B1-BC8, L. gasseri BC9-BC14 and L. vaginalis BC15-BC17 by sequencing the 16S rRNA genes. All strains produced hydrogen peroxide and lactate. Fungistatic and fungicidal activities against C. albicans, C. glabrata, C. krusei, C. tropicalis, C. parapsilosis and C. lusitaniae were evaluated by broth micro-dilution method. The broadest spectrum of activity was observed for L. crispatus BC1, BC4, BC5 and L. vaginalis BC15, demonstrating fungicidal activity against all isolates of C. albicans and C. lusitaniae. Metabolic profiles of lactobacilli supernatants were studied by 1H-NMR analysis. Metabolome was found to be correlated with both taxonomy and activity score. Exclusion, competition and displacement experiments were carried out to investigate the interference exerted by lactobacilli toward the yeast adhesion to HeLa cells. Most Lactobacillus strains significantly reduced C. albicans adhesion through all mechanisms. In particular, L. crispatus BC2, L. gasseri BC10 and L. gasseri BC11 appeared to be the most active strains in reducing pathogen adhesion, as their effects were mediated by both cells and supernatants. Inhibition of histone deacetylases was hypothesised to support the antifungal activity of vaginal lactobacilli. Our results are prerequisites for the development of new therapeutic agents based on probiotics for prophylaxis and adjuvant therapy of Candida infection.

  6. Yeast strains role on the sulphur dioxyde combinations of wines obtained from noble rot and raisining grapes

    Directory of Open Access Journals (Sweden)

    Isabelle Masneuf-Pomarède

    2000-03-01

    Full Text Available The influence of four industrial and indigenous yeast strains on the sulphur dioxide combinations of wines obtained from noble rot and raisining grapes is studied in different growth of the Sauternes area and one growth in the Jurançon area. The analysis of ketonic compounds (pyruvic acid and 2-oxo-glutaric acid, acetaldehyde and PC50 on the wines clearly showed significant statistical difference between the yeast strains for the sulphur dioxide combination. By adding the same dosage of sulphiting, the free SO2 levels are variable depending on the yeast strain used. One strain (Zymaflore ST, isolated from a spontaneous fermentation of a botrytised must, giving wines with low PC50 values, is well adapted for the noble rot must vinification. The choice of the yeast strain is a parameter of importance to limit the sulphur dioxide amount in the wines.

  7. Chemical signaling and insect attraction is a conserved trait in yeasts.

    Science.gov (United States)

    Becher, Paul G; Hagman, Arne; Verschut, Vasiliki; Chakraborty, Amrita; Rozpędowska, Elżbieta; Lebreton, Sébastien; Bengtsson, Marie; Flick, Gerhard; Witzgall, Peter; Piškur, Jure

    2018-03-01

    Yeast volatiles attract insects, which apparently is of mutual benefit, for both yeasts and insects. However, it is unknown whether biosynthesis of metabolites that attract insects is a basic and general trait, or if it is specific for yeasts that live in close association with insects. Our goal was to study chemical insect attractants produced by yeasts that span more than 250 million years of evolutionary history and vastly differ in their metabolism and lifestyle. We bioassayed attraction of the vinegar fly Drosophila melanogaster to odors of phylogenetically and ecologically distinct yeasts grown under controlled conditions. Baker's yeast Saccharomyces cerevisiae , the insect-associated species Candida californica , Pichia kluyveri and Metschnikowia andauensis , wine yeast Dekkera bruxellensis , milk yeast Kluyveromyces lactis , the vertebrate pathogens Candida albicans and Candida glabrata , and oleophilic Yarrowia lipolytica were screened for fly attraction in a wind tunnel. Yeast headspace was chemically analyzed, and co-occurrence of insect attractants in yeasts and flowering plants was investigated through a database search. In yeasts with known genomes, we investigated the occurrence of genes involved in the synthesis of key aroma compounds. Flies were attracted to all nine yeasts studied. The behavioral response to baker's yeast was independent of its growth stage. In addition to Drosophila , we tested the basal hexapod Folsomia candida (Collembola) in a Y-tube assay to the most ancient yeast, Y. lipolytica, which proved that early yeast signals also function on clades older than neopteran insects. Behavioral and chemical data and a search for selected genes of volatile metabolites underline that biosynthesis of chemical signals is found throughout the yeast clade and has been conserved during the evolution of yeast lifestyles. Literature and database reviews corroborate that yeast signals mediate mutualistic interactions between insects and yeasts

  8. Saccharomyces boulardii and Candida albicans experimental colonization of the murine gut.

    Science.gov (United States)

    Samonis, G; Falagas, M E; Lionakis, S; Ntaoukakis, M; Kofteridis, D P; Ntalas, I; Maraki, S

    2011-05-01

    Saccharomyces boulardii has been and continues to be extensively used as a probiotic, with only rare associations with fungemia. This study evaluated the virulence of this yeast when given as a probiotic, and its role in preventing gastrointestinal (GI) colonization by Candida. Adult male Crl:CD1 (ICR) BR mice were given S. boulardii orally in three different doses or normal saline for 14 days. Stool cultures were performed at the time of discontinuation of yeast administration, as well as 1 and 2 weeks later. Gut colonization was proportional to the given dose but lasted only 1 week and no dissemination of the yeast was detected. S. boulardii was also given for 2 and 4 weeks to mice fed chow containing Candida albicans. S. boulardii in the gut did not affect Candida GI colonization. These findings suggest that oral administration of S. boulardii induces a substantial but short term increase of this yeast in the intestinal lumen and administration of the probiotic does not prevent subsequent GI colonization by C. albicans.

  9. Binding and Conversion of Selenium in Candida utilis ATCC 9950 Yeasts in Bioreactor Culture

    Directory of Open Access Journals (Sweden)

    Marek Kieliszek

    2017-02-01

    Full Text Available Selenium is considered an essential component of all living organisms. The use of yeasts as a selenium supplement in human nutrition has gained much interest over the last decade. The accumulation and biochemical transformation of selenium in yeast cells is particularly interesting to many researchers. In this article, we present the results of the determination of selenium and selenomethionine content in the biomass of feed yeast Candida utilis ATCC 9950 obtained from the culture grown in a bioreactor. The results indicated that C. utilis cells performed the biotransformation of inorganic selenium(IV to organic derivatives (e.g., selenomethionine. Selenium introduced (20–30 mg Se4+∙L−1 to the experimental media in the form of sodium(IV selenite (Na2SeO3 salt caused a significant increase in selenium content in the biomass of C. utilis,irrespective of the concentration. The highest amount of selenium (1841 μg∙gd.w.−1 was obtained after a 48-h culture in media containing 30 mg Se4+∙L−1. The highest content of selenomethionine (238.8 μg∙gd.w.−1 was found after 48-h culture from the experimental medium that was supplemented with selenium at a concentration of 20 mg Se4+∙L−1. Biomass cell in the cultures supplemented with selenium ranged from 1.5 to 14.1 g∙L−1. The results of this study indicate that yeast cell biomass of C. utilis enriched mainly with the organic forms of selenium can be a valuable source of protein. It creates the possibility of obtaining selenium biocomplexes that can be used in the production of protein-selenium dietary supplements for animals and humans

  10. Vinegar as an antimicrobial agent for control of Candida spp. in complete denture wearers

    Directory of Open Access Journals (Sweden)

    Telma Maria Silva Pinto

    2008-12-01

    Full Text Available The use of denture is known to increase the carriage of Candida in healthy patients, and the proliferation of Candida albicans strains can be associated with denture-induced stomatitis. The aim of this study was to evaluate the use of vinegar as an antimicrobial agent for control of Candida spp. in complete upper denture wearers. Fifty-five patients were submitted to a detailed clinical interview and oral clinical examination, and were instructed to keep their dentures immersed in a 10% vinegar solution (pH less than 3 overnight for 45 days. Before and after the experimental period, saliva samples were collected for detection of Candida, counting of cfu/mL and identification of species by phenotypical tests (germ tube formation, chlamidoconidia production, and carbohydrate fermentation and assimilation. The results were analyzed using Spearman's correlation and Student's t-test (p£0.05. Candida yeasts were present in 87.3% of saliva samples before the treatment. A significant reduction was verified in CFU/mL counts of Candida after treatment. A positive correlation between Candida and denture stomatitis was verified, since the decrease of cfu/mL counts was correlated with a reduction in cases of denture stomatitis. Although it was not able to eliminate C. albicans, the immersion of the complete denture in 10% vinegar solution, during the night, reduced the amounts (cfu/mL of Candida spp. in the saliva and the presence of denture stomatitis in the studied patients.

  11. Candida species isolated from different body sites and their antifungal susceptibility pattern: Cross-analysis of Candida albicans and Candida glabrata biofilms.

    Science.gov (United States)

    Cataldi, Valentina; Di Campli, Emanuela; Fazii, Paolo; Traini, Tonino; Cellini, Luigina; Di Giulio, Mara

    2017-08-01

    Candida species are regular commensal in humans, but-especially in immunocompromised patients-they represent opportunistic pathogens giving rise to systemic infection. The aim of the present work was to isolate and characterize for their antifungal profile Candida species from different body sites and to analyze the biofilms produced by C. albicans and C. glabrata isolates. Eighty-one strains of Candida species from 77 patients were identified. Epidemiological study showed that the most isolated species were C. albicans (44), C. glabrata (13) and C. parapsilosis (13) mainly from Hematology, Infectious Diseases, Medicine, Neonatology and Oncology Divisions, the majority of the biological samples were swabs (44) and blood cultures (16). The analysis of the biofilm formation was performed at 24 and 48-hours comparing resistant and susceptible strains of C. albicans to resistant and susceptible strains of C. glabrata. Candida albicans has a greater ability to form biofilm compared to C. glabrata, both in the susceptible and resistant strains reaching maturity after 24 hours with a complex structure composed of blastospores, pseudohyphae, and hyphae embedded in a matrix. On the contrary, C. glabrata biofilm was composed exclusively of blastospores that in the resistant strain, after 24 hours, were organized in a compact multilayer different to the discontinuous structure observed in the susceptible analyzed strains. In conclusion, the increasing of the incidence of Candida species infection together with their emerging drug resistance also related to the biofilm forming capability underline the need to monitor their distribution and susceptibility patterns for improving the surveillance and for a correct management of the infection. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. New hybrids between Saccharomyces sensu stricto yeast species found among wine and cider production strains

    DEFF Research Database (Denmark)

    Masneuf, I; Hansen, J.; Groth, C

    1998-01-01

    Two yeast isolates, a wine-making yeast first identified as a Mel(+) strain (ex. S. uvarum) and a cider-making yeast, were characterized for their nuclear and mitochondrial genomes, Electrophoretic karyotyping analyses, restriction fragment length polymorphism maps of PCR-amplified MET2 gene...

  13. Diferenciação de cepas de Candida albicans pelo sistema killer

    Directory of Open Access Journals (Sweden)

    Regina Celia Cândido

    1995-12-01

    Full Text Available Foi estudado o efeito killer de 9 cepas padrão de leveduras sobre 146 amostras de Candida albicans isoladas dos seguintes espécimes clínicos: mucosa bucal, fezes, lavado brônquico, escarro, secreção vaginal, urina, lesão de pele, lesão de unha e sangue. Usando este sistema foi possível diferenciar 23 biotipos de C. albicans. Os biotipos 211, 111 e 811 foram os mais freqüentemente isolados. A maioria das amostras de C. albicans (98,6% foi sensível a pelo menos uma ou mais das 9 cepas killer. Empregando- se este sistema foi possível demonstrar que 2 pacientes albergavam mesmo biotipo killer, respectivamente, 111 e 211, em diferentes espécimes clínicos, e em outro paciente, o mesmo biotipo (211 foi isolado de hemoculturas realizadas em ocasiões distintas. O uso do sistema killer para diferenciar os tipos entre as espécies de leveduras patogênicas, pode ser um método útil para estabelecer a eventual fonte de infecção, constituindo uma ajuda valiosa para o controle e vigilância de infecções nosocomiais causadas por leveduras.The authors studied the killer effect of nine standard strains of yeasts on 146 samples of Candida albicans isolated from the following clinical specimens: oral mucosa, feces, bronchial wash, sputum, vaginal secretion, urine, skin lesion, nail lesion and blood. Using this system it was possible to differentiate 23 biotypes of Candida albicans. The biotypes 211, 111 and 811 were most frequently isolated. Most of the samples of C. albicans (98.6% were sensitive to at least one or more of the nine killer strains. Using the killer system it was possible to show that two patients harbored the same killer biotypes, 111 and 211, respectively, in different clinical specimens and another patient harbored the same biotype (211 in blood cultures effected in different ocasions. The utilization of the killer system to differentiate types among species of pathogenic yeasts can be a useful method to stablish the eventual

  14. Accessibility and contribution to glucan masking of natural and genetically tagged versions of yeast wall protein 1 of Candida albicans.

    Science.gov (United States)

    Granger, Bruce L

    2018-01-01

    Yeast wall protein 1 (Ywp1) is an abundant glycoprotein of the cell wall of the yeast form of Candida albicans, the most prevalent fungal pathogen of humans. Antibodies that bind to the polypeptide backbone of isolated Ywp1 show little binding to intact yeast cells, presumably because the Ywp1 epitopes are masked by the polysaccharides of the mannoproteins that form the outer layer of the cell wall. Rare cells do exhibit much greater anti-Ywp1 binding, however, and one of these was isolated and characterized. No differences were seen in its Ywp1, but it exhibited greater adhesiveness, sensitivity to wall perturbing agents, and exposure of its underlying β-1,3-glucan layer to external antibodies. The molecular basis for this greater epitope accessibility has not been determined, but has facilitated exploration of how these properties change as a function of cell growth and morphology. In addition, previously engineered strains with reduced quantities of Ywp1 in their cell walls were also found to have greater β-1,3-glucan exposure, indicating that Ywp1 itself contributes to the masking of wall epitopes, which may be important for understanding the anti-adhesive effect of Ywp1. Ectopic production of Ywp1 by hyphae, which reduces the adhesivity of these filamentous forms of C. albicans, was similarly found to reduce exposure of the β-1,3-glucan in their walls. To monitor Ywp1 in the cell wall irrespective of its accessibility, green fluorescent protein (Gfp) was genetically inserted into wall-anchored Ywp1 using a bifunctional cassette that also allowed production from a single transfection of a soluble, anchor-free version. The wall-anchored Ywp1-Gfp-Ywp1 accumulated in the wall of the yeast forms but not hyphae, and appeared to have properties similar to native Ywp1, including its adhesion-inhibiting effect. Some pseudohyphal walls also detectably accumulated this probe. Strains of C. albicans with tandem hemagglutinin (HA) epitopes inserted into wall

  15. Accessibility and contribution to glucan masking of natural and genetically tagged versions of yeast wall protein 1 of Candida albicans.

    Directory of Open Access Journals (Sweden)

    Bruce L Granger

    Full Text Available Yeast wall protein 1 (Ywp1 is an abundant glycoprotein of the cell wall of the yeast form of Candida albicans, the most prevalent fungal pathogen of humans. Antibodies that bind to the polypeptide backbone of isolated Ywp1 show little binding to intact yeast cells, presumably because the Ywp1 epitopes are masked by the polysaccharides of the mannoproteins that form the outer layer of the cell wall. Rare cells do exhibit much greater anti-Ywp1 binding, however, and one of these was isolated and characterized. No differences were seen in its Ywp1, but it exhibited greater adhesiveness, sensitivity to wall perturbing agents, and exposure of its underlying β-1,3-glucan layer to external antibodies. The molecular basis for this greater epitope accessibility has not been determined, but has facilitated exploration of how these properties change as a function of cell growth and morphology. In addition, previously engineered strains with reduced quantities of Ywp1 in their cell walls were also found to have greater β-1,3-glucan exposure, indicating that Ywp1 itself contributes to the masking of wall epitopes, which may be important for understanding the anti-adhesive effect of Ywp1. Ectopic production of Ywp1 by hyphae, which reduces the adhesivity of these filamentous forms of C. albicans, was similarly found to reduce exposure of the β-1,3-glucan in their walls. To monitor Ywp1 in the cell wall irrespective of its accessibility, green fluorescent protein (Gfp was genetically inserted into wall-anchored Ywp1 using a bifunctional cassette that also allowed production from a single transfection of a soluble, anchor-free version. The wall-anchored Ywp1-Gfp-Ywp1 accumulated in the wall of the yeast forms but not hyphae, and appeared to have properties similar to native Ywp1, including its adhesion-inhibiting effect. Some pseudohyphal walls also detectably accumulated this probe. Strains of C. albicans with tandem hemagglutinin (HA epitopes inserted into

  16. Selection of Yeast Strains for Tequila Fermentation Based on Growth Dynamics in Combined Fructose and Ethanol Media.

    Science.gov (United States)

    Aldrete-Tapia, J A; Miranda-Castilleja, D E; Arvizu-Medrano, S M; Hernández-Iturriaga, M

    2018-02-01

    The high concentration of fructose in agave juice has been associated with reduced ethanol tolerance of commercial yeasts used for tequila production and low fermentation yields. The selection of autochthonous strains, which are better adapted to agave juice, could improve the process. In this study, a 2-step selection process of yeasts isolated from spontaneous fermentations for tequila production was carried out based on analysis of the growth dynamics in combined conditions of high fructose and ethanol. First, yeast isolates (605) were screened to identify strains tolerant to high fructose (20%) and to ethanol (10%), yielding 89 isolates able to grow in both conditions. From the 89 isolates, the growth curves under 8 treatments of combined fructose (from 20% to 5%) and ethanol (from 0% to 10%) were obtained, and the kinetic parameters were analyzed with principal component analysis and k-means clustering. The resulting yeast strain groups corresponded to the fast, medium and slow growers. A second clustering of only the fast growers led to the selection of 3 Saccharomyces strains (199, 230, 231) that were able to grow rapidly in 4 out of the 8 conditions evaluated. This methodology differentiated strains phenotypically and could be further used for strain selection in other processes. A method to select yeast strains for fermentation taking into account the natural differences of yeast isolates. This methodology is based on the cell exposition to combinations of sugar and ethanol, which are the most important stress factors in fermentation. This strategy will help to identify the most tolerant strain that could improve ethanol yield and reduce fermentation time. © 2018 Institute of Food Technologists®.

  17. Azole resistance in Candida spp. isolated from Catú Lake, Ceará, Brazil: an efflux-pump-mediated mechanism

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    Raimunda S.N. Brilhante

    2016-03-01

    Full Text Available Abstract Since, there is no study reporting the mechanism of azole resistance among yeasts isolated from aquatic environments; the present study aims to investigate the occurrence of antifungal resistance among yeasts isolated from an aquatic environment, and assess the efflux-pump activity of the azole-resistant strains to better understand the mechanism of resistance for this group of drugs. For this purpose, monthly water and sediment samples were collected from Catú Lake, Ceará, Brazil, from March 2011 to February 2012. The obtained yeasts were identified based on morphological and biochemical characteristics. Of the 46 isolates, 37 were Candida spp., 4 were Trichosporon asahii, 3 were Cryptococcus laurentii, 1 Rhodotorula mucilaginosa, and 1 was Kodamaea ohmeri. These isolates were subjected to broth microdilution assay with amphotericin B, itraconazole, and fluconazole, according to the methodology standardized by the Clinical and Laboratory Standards Institute (CLSI. The minimum inhibitory concentrations (MICs of amphotericin B, itraconazole, and fluconazole were 0.03125–2 µg/mL, 0.0625 to ≥16 µg/mL, and 0.5 to ≥64 µg/mL, respectively, and 13 resistant azole-resistant Candida isolates were detected. A reduction in the azole MICs leading to the phenotypical reversal of the azole resistance was observed upon addition of efflux-pump inhibitors. These findings suggest that the azole resistance among environmental Candida spp. is most likely associated with the overexpression of efflux-pumps.

  18. Investigation of Antibacterial Properties of Yeast Strains Isolated from Iranian Richal and Traditional Dairy Products in Armenia

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    F Karimpour

    2016-09-01

    Full Text Available Background & aim:The use of bio preservative or strains as sources are interesting for food bioprocessing technologist,   and is one of the latest methods to increase the shelf life of food by the health authorities . The present study aimed to investigate the antibacterial activity of supernatants of yeasts isolated from Richal as a traditional dairy product and fermented dairy products in Armenia. Methods: In the present experimental study, the purified supernatant of 77 strains of Armenian yeast products and 12 strains from Iranian Richal were isolated. The purified supernatant were tested against three strains as food spoilages bacteria includes: B. subtilis 17-89, B. Thuringensis17-89, S.typhimuium G-38 , on 3media in 2 condition as aerobic and anaerobic. The inhibition zone of the supernatant were measured   and reported as antibacterial activity. Data were analyzed using statistical tests. Result: A total of 89 strains of yeasts, three species of Rachel and 9 strains of Armenian products (13.5% percent had demonstrated antibacterial activity. T86 strains of Armenian yeasts and FA1 (25 of Rachel had shown more ZOI and antibacterial activity on three media at both aerobic and anaerobic conditions. Comparing the mean of ZOI upon three corruption factors, Rachel strains were significantly different (p <0.05. The highest and lowest effect was observed on Bacillus subtilis effect and Salmonella typhimurium respectively. Conclusion: The results indicated that the yeast strains isolated in anaerobic and aerobic conditions on spoilage bacteria had antibacterial activity effect. Thus, it could be concluded that adding the yeast or its supernatant to food as a bio preservative, may introduce a operative product to the food industry.

  19. Plasticity of Candida albicans Biofilms

    Science.gov (United States)

    Daniels, Karla J.

    2016-01-01

    SUMMARY Candida albicans, the most pervasive fungal pathogen that colonizes humans, forms biofilms that are architecturally complex. They consist of a basal yeast cell polylayer and an upper region of hyphae encapsulated in extracellular matrix. However, biofilms formed in vitro vary as a result of the different conditions employed in models, the methods used to assess biofilm formation, strain differences, and, in a most dramatic fashion, the configuration of the mating type locus (MTL). Therefore, integrating data from different studies can lead to problems of interpretation if such variability is not taken into account. Here we review the conditions and factors that cause biofilm variation, with the goal of engendering awareness that more attention must be paid to the strains employed, the methods used to assess biofilm development, every aspect of the model employed, and the configuration of the MTL locus. We end by posing a set of questions that may be asked in comparing the results of different studies and developing protocols for new ones. This review should engender the notion that not all biofilms are created equal. PMID:27250770

  20. Selection of non-Saccharomyces yeast strains for reducing alcohol levels in wine by sugar respiration.

    Science.gov (United States)

    Quirós, Manuel; Rojas, Virginia; Gonzalez, Ramon; Morales, Pilar

    2014-07-02

    Respiration of sugars by non-Saccharomyces yeasts has been recently proposed for lowering alcohol levels in wine. Development of industrial fermentation processes based on such an approach requires, amongst other steps, the identification of yeast strains which are able to grow and respire under the relatively harsh conditions found in grape must. This work describes the characterization of a collection of non-Saccharomyces yeast strains in order to identify candidate yeast strains for this specific application. It involved the estimation of respiratory quotient (RQ) values under aerated conditions, at low pH and high sugar concentrations, calculation of yields of ethanol and other relevant metabolites, and characterization of growth responses to the main stress factors found during the first stages of alcoholic fermentation. Physiological features of some strains of Metschnikowia pulcherrima or two species of Kluyveromyces, suggest they are suitable for lowering ethanol yields by respiration. The unsuitability of Saccharomyces cerevisiae strains for this purpose was not due to ethanol yields (under aerated conditions they are low enough for a significant reduction in final ethanol content), but to the high acetic acid yields under these growth conditions. According to results from controlled aeration fermentations with one strain of M. pulcherrima, design of an aeration regime allowing for lowering ethanol yields though preserving grape must components from excessive oxidation, would be conceivable. Copyright © 2014. Published by Elsevier B.V.

  1. Postantifungal Effect of Micafungin against the Species Complexes of Candida albicans and Candida parapsilosis.

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    Sandra Gil-Alonso

    Full Text Available Micafungin is an effective antifungal agent useful for the therapy of invasive candidiasis. Candida albicans is the most common cause of invasive candidiasis; however, infections due to non-C. albicans species, such as Candida parapsilosis, are rising. Killing and postantifungal effects (PAFE are important factors in both dose interval choice and infection outcome. The aim of this study was to determinate the micafungin PAFE against 7 C. albicans strains, 5 Candida dubliniensis, 2 Candida Africana, 3 C. parapsilosis, 2 Candida metapsilosis and 2 Candida orthopsilosis. For PAFE studies, cells were exposed to micafungin for 1 h at concentrations ranging from 0.12 to 8 μg/ml. Time-kill experiments (TK were conducted at the same concentrations. Samples were removed at each time point (0-48 h and viable counts determined. Micafungin (2 μg/ml was fungicidal (≥ 3 log10 reduction in TK against 5 out of 14 (36% strains of C. albicans complex. In PAFE experiments, fungicidal endpoint was achieved against 2 out of 14 strains (14%. In TK against C. parapsilosis, 8 μg/ml of micafungin turned out to be fungicidal against 4 out 7 (57% strains. Conversely, fungicidal endpoint was not achieved in PAFE studies. PAFE results for C. albicans complex (41.83 ± 2.18 h differed from C. parapsilosis complex (8.07 ± 4.2 h at the highest tested concentration of micafungin. In conclusion, micafungin showed significant differences in PAFE against C. albicans and C. parapsilosis complexes, being PAFE for the C. albicans complex longer than for the C. parapsilosis complex.

  2. Improving yeast strains using recyclable integration cassettes, for the production of plant terpenoids

    Directory of Open Access Journals (Sweden)

    Johnson Christopher B

    2011-01-01

    Full Text Available Abstract Background Terpenoids constitute a large family of natural products, attracting commercial interest for a variety of uses as flavours, fragrances, drugs and alternative fuels. Saccharomyces cerevisiae offers a versatile cell factory, as the precursors of terpenoid biosynthesis are naturally synthesized by the sterol biosynthetic pathway. Results S. cerevisiae wild type yeast cells, selected for their capacity to produce high sterol levels were targeted for improvement aiming to increase production. Recyclable integration cassettes were developed which enable the unlimited sequential integration of desirable genetic elements (promoters, genes, termination sequence at any desired locus in the yeast genome. The approach was applied on the yeast sterol biosynthetic pathway genes HMG2, ERG20 and IDI1 resulting in several-fold increase in plant monoterpene and sesquiterpene production. The improved strains were robust and could sustain high terpenoid production levels for an extended period. Simultaneous plasmid-driven co-expression of IDI1 and the HMG2 (K6R variant, in the improved strain background, maximized monoterpene production levels. Expression of two terpene synthase enzymes from the sage species Salvia fruticosa and S. pomifera (SfCinS1, SpP330 in the modified yeast cells identified a range of terpenoids which are also present in the plant essential oils. Co-expression of the putative interacting protein HSP90 with cineole synthase 1 (SfCinS1 also improved production levels, pointing to an additional means to improve production. Conclusions Using the developed molecular tools, new yeast strains were generated with increased capacity to produce plant terpenoids. The approach taken and the durability of the strains allow successive rounds of improvement to maximize yields.

  3. Ecology of Candida-associated Denture Stomatitis

    OpenAIRE

    Budtz-Jørgensen, Ejvind

    2011-01-01

    Introduction of a prosthesis into the oral cavity results in profound alterations of the environmental conditions as the prosthesis and the underlying mucosa become colonized with oral microorganisms, including Candida spp. This may lead to denture stomatitis, a non-specific inflammatory reaction against microbial antigens, toxins and enzymes produced by the colonizing microorganisms. The role of Candida in the etiology of denture stomatitis is indicated by an increased number of yeasts on th...

  4. Effects of lignin-derived phenolic compounds on xylitol production and key enzyme activities by a xylose utilizing yeast Candida athensensis SB18.

    Science.gov (United States)

    Zhang, Jinming; Geng, Anli; Yao, Chuanyi; Lu, Yinghua; Li, Qingbiao

    2012-10-01

    Candida athensensis SB18 is potential xylitol producing yeast isolated in Singapore. It has excellent xylose tolerance and is able to produce xylitol in high titer and yield. However, by-products, such as phenolic compounds, derived in lignocellulosic biomass hydrolysate might negatively influence the performance of this strain for xylitol production. In this work, four potential phenolic inhibitors, such as vanillin, syringaldehyde, 4-hydroxybenzaldehyde and phenol, were evaluated for their inhibitory effects on xylitol production by C. athensensis SB18. Phenol was shown to be the most toxic molecule on this microorganism followed by syringaldehyde. Vanillin and 4-hydroxylbenzaldehyde was less toxic than phenol and syringaldehyde, with vanillin being the least toxic. Inhibition was insignificant when the total content of inhibitors was below 1.0 g/L. The presence of phenolic compounds affected the activity of xylose reductase, however not on that of xylitol dehydrogenase. C. athensensis SB18 is therefore a potential xylitol producer from hemicellulosic hydrolysate due to its assimilation of such phenolic inhibitors. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Novel structural features in Candida albicans hyphal glucan provide a basis for differential innate immune recognition of hyphae versus yeast.

    Science.gov (United States)

    Lowman, Douglas W; Greene, Rachel R; Bearden, Daniel W; Kruppa, Michael D; Pottier, Max; Monteiro, Mario A; Soldatov, Dmitriy V; Ensley, Harry E; Cheng, Shih-Chin; Netea, Mihai G; Williams, David L

    2014-02-07

    The innate immune system differentially recognizes Candida albicans yeast and hyphae. It is not clear how the innate immune system effectively discriminates between yeast and hyphal forms of C. albicans. Glucans are major components of the fungal cell wall and key fungal pathogen-associated molecular patterns. C. albicans yeast glucan has been characterized; however, little is known about glucan structure in C. albicans hyphae. Using an extraction procedure that minimizes degradation of the native structure, we extracted glucans from C. albicans hyphal cell walls. (1)H NMR data analysis revealed that, when compared with reference (1→3,1→6) β-linked glucans and C. albicans yeast glucan, hyphal glucan has a unique cyclical or "closed chain" structure that is not found in yeast glucan. GC/MS analyses showed a high abundance of 3- and 6-linked glucose units when compared with yeast β-glucan. In addition to the expected (1→3), (1→6), and 3,6 linkages, we also identified a 2,3 linkage that has not been reported previously in C. albicans. Hyphal glucan induced robust immune responses in human peripheral blood mononuclear cells and macrophages via a Dectin-1-dependent mechanism. In contrast, C. albicans yeast glucan was a much less potent stimulus. We also demonstrated the capacity of C. albicans hyphal glucan, but not yeast glucan, to induce IL-1β processing and secretion. This finding provides important evidence for understanding the immune discrimination between colonization and invasion at the mucosal level. When taken together, these data provide a structural basis for differential innate immune recognition of C. albicans yeast versus hyphae.

  6. Hyphal-like extension and pseudohyphal formation in industrial strains of yeasts induced by isoamyl alcohol

    Directory of Open Access Journals (Sweden)

    Ceccato-Antonini Sandra Regina

    2002-01-01

    Full Text Available Yeasts can produce pseudohyphae and hyphal-like extensions under certain growth conditions like isoamyl alcohol (IAA induction, a chief constituent of fusel oil, which is a subproduct from the ethanolic fermentation. The morphology switch from yeast to a filamentous form can be troublesome to the process. In this work it was studied the influence of fusel alcohols, nitrogen sources (ammonium sulphate and leucine and glifosate (a chemical maturator for sugar cane added to a complex medium on some industrial strains of yeasts isolated from the fermentative process. Two industrial strains showed transition to hyphal-like extensions or pseudohyphae (clusters of cells upon addition of IAA from 0.3 to 0.9% /v. The alterations were reversible when the yeasts were reinoculated in YEPD without IAA. Although pseudohyphae are a result of nitrogen-limited medium, we observed them as a result of IAA addition. No influence of the nitrogen source or isopropilic alcohol or glifosate was detected for any strain studied in the concentrations used.

  7. Probiotic Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 exhibit strong antifungal effects against vulvovaginal candidiasis-causing Candida glabrata isolates.

    Science.gov (United States)

    Chew, S Y; Cheah, Y K; Seow, H F; Sandai, D; Than, L T L

    2015-05-01

    This study investigates the antagonistic effects of the probiotic strains Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 against vulvovaginal candidiasis (VVC)-causing Candida glabrata. Growth inhibitory activities of Lact. rhamnosus GR-1 and Lact. reuteri RC-14 strains against C. glabrata were demonstrated using a spot overlay assay and a plate-based microtitre assay. In addition, these probiotic lactobacilli strains also exhibited potent candidacidal activity against C. glabrata, as demonstrated by a LIVE/DEAD yeast viability assay performed using confocal laser scanning microscopy. The metabolic activities of all C. glabrata strains were completely shut down in response to the challenges by the probiotic lactobacilli strains. In addition, both probiotic lactobacilli strains exhibited strong autoaggregation and coaggregation phenotypes in the presence of C. glabrata, which indicate that these lactobacilli strains may exert their probiotic effects through the formation of aggregates and, thus the consequent prevention of colonization by C. glabrata. Probiotic Lact. rhamnosus GR-1 and Lact. reuteri RC-14 strains exhibited potent antagonistic activities against all of the tested C. glabrata strains. These lactobacilli exhibited antifungal effects, including those attributed to their aggregation abilities, and their presence caused the cessation of growth and eventual cell death of C. glabrata. This is the first study to report on the antagonistic effects of these probiotic lactobacilli strains against the non-Candida albicans Candida (NCAC) species C. glabrata. © 2015 The Authors published by John Wiley & Sons Ltd on behalf of Society for Applied Microbiology.

  8. [Evaluation of mass spectrometry for the identification of clinically interesting yeasts].

    Science.gov (United States)

    Galán, Fátima; García-Agudo, Lidia; Guerrero, Inmaculada; Marín, Pilar; García-Tapia, Ana; García-Martos, Pedro; Rodríguez-Iglesias, Manuel

    2015-01-01

    Identification of yeasts is based on morphological, biochemical and nutritional characteristics, and using molecular methods. Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, a new method for the identification of microorganisms, has demonstrated to be very useful. The aim of this study is to evaluate this new method in the identification of yeasts. A total of 600 strains of yeasts isolated from clinical specimens belonging to 9 genera and 43 species were tested. Identification was made by sequencing of the ITS regions of ribosomal DNA, assimilation of carbon compounds (ID 32C), and mass spectrometry on a Microflex spectrometer (Bruker Daltonics GmbH, Germany). A total of 569 strains (94.8%) were identified to species level by ID 32C, and 580 (96.7%) by MALDI-TOF. Concordance between both methods was observed for 553 strains (92.2%), with 100% in clinically relevant species: C. albicans, C. glabrata, C. parapsilosis, C. tropicalis, and almost 100% in C. krusei. MALDI-TOF identified species requiring molecular methods: Candida dubliniensis, C. nivariensis, C. metapsilosis and C. orthopsilosis. Some irregularities were observed in the identification of arthroconidia yeast and basidiomycetes. MALDI-TOF is a rapid, effective and economic method, which enables the identification of most clinically important yeasts and the differentiation of closely related species. It would be desirable to include more species in its database to expand its performance. Copyright © 2014 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  9. Productividad y selectividad del medio de cultivo a partir de guayaba agria (Psidium araca en el crecimiento de levaduras nativas del género Candida sp

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    Cecilia Lara Mantilla

    2010-07-01

    Full Text Available Título en inglés: Productivity and selectivity of culture medium from the sour guava (Psidium araca in the growth of native yeast Candida sp Resumen El presente trabajo se llevó a cabo para evaluar la eficiencia del medio de cultivo a partir de guayaba agria (Psidium araca frente a medios comerciales en el crecimiento de tres cepas nativas: Candida guillermondii, Candida famita y Candida sp. Se evaluó el crecimiento microbiano a diferentes concentraciones de fruta, 5, 10, 25 y 50% p/v, tomando como control los medios comerciales: Malta, Sabouraud y agar papa dextrosa (PDA. La productividad y selectividad del medio de guayaba agria fue determinada mediante el método Ecométrico en un tiempo de 48 horas. Los análisis estadísticos aplicados para evaluar y comparar el crecimiento de las cepas en los medios comerciales y en el medio de guayaba agria a diferentes concentraciones demostraron lo siguiente: Candida guillermondii presentó crecimiento mayor o igual a 25 y 50% p/v comparado con los medios comerciales; Candida famata y Candida sp presentaron mejores crecimientos al 5% p/v, con respecto a los diferentes medios comerciales. Los resultados demostraron que el medio de cultivo es altamente productivo y no selectivo, lo que representa una alternativa en la conservación, el mantenimiento y el desarrollo de las levaduras estudiadas. Palabras clave: método Ecométrico; Candida guillermondii; Candida famata; Candida sp. Abstract This work was carried out to evaluate the efficiency of the culture medium from sour guava (Psidium araca against commercial media in the growth of three native strains: Candida guillermondii, Candida famata and Candida sp. Microbial growth was evaluated at different concentrations of fruit, 5, 10, 25, 50% w /v, using as control the commercial media: Malta, Sabouraud and PDA (Potato Dextrose Agar. The productivity and selectivity of the sour guava medium was determined by the Ecometric method in a time of 48 hours

  10. Hybridization of halotolerant yeast for alcohol fermentation

    International Nuclear Information System (INIS)

    Limtong, S.

    1991-01-01

    Attempt have been made to construct a new yeast strain from alcohol fermenting strains and salt tolerant strains. It is anticipated that the new yeast strain will be able to ferment alcohol in molasses mash with high salinity, up to 3% of NaCl. Another characteristics is its ability to tolerate up to 40 C temperature which is desirable for alcohol fermentation in tropical countries. Commercial and wild strains of Saccharomyces cerevisiae were screened for their fermenting ability and strain SC90, 191 TJ3, and AM12 were selected as parental strains for fusion among themselves and with other halo tolerant species. Halo tolerant strains selected at 5% NaCl in molasses mash were tentatively identified as Torulopsis grabrata, T. candida, T. Bovina and S. Rouxii whereas all of those strains selected at 17% NaCl were Citeromyces sp. It was found that fusant TA73 derived from wild strain and sake fermenting strain performed best among 4,087 fusants investigated. This fusant fermented much better than their parental strains when salt concentrations were increased to 5 and 7% NaCl. Experiment was carried out in fermentor, 1.5 liter working volume using molasses mash with 3% NaCl and temperature was controlled at 35 degree C. Fermentation rate of TA73, TJ3 and AM12 were 2.17, 1.50 and 1.87 g/L/hr respectively, Maximum ethanol concentration obtained were 7.6, 6.7 and 7.4% by weight after 60 and 78 hours respectively. Other fusants derived from fusion of Saccharomyces cerevisiae with other halo tolerant species were mostly inferior to their parental strains and only 7 fusants were slightly better than parental strains. (author)

  11. Antifungal Efficacy during Candida krusei Infection in Non-Conventional Models Correlates with the Yeast In Vitro Susceptibility Profile

    Science.gov (United States)

    Scorzoni, Liliana; de Lucas, Maria Pilar; Mesa-Arango, Ana Cecilia; Fusco-Almeida, Ana Marisa; Lozano, Encarnación; Cuenca-Estrella, Manuel; Mendes-Giannini, Maria Jose; Zaragoza, Oscar

    2013-01-01

    The incidence of opportunistic fungal infections has increased in recent decades due to the growing proportion of immunocompromised patients in our society. Candida krusei has been described as a causative agent of disseminated fungal infections in susceptible patients. Although its prevalence remains low among yeast infections (2–5%), its intrinsic resistance to fluconazole makes this yeast important from epidemiologic aspects. Non mammalian organisms are feasible models to study fungal virulence and drug efficacy. In this work we have used the lepidopteran Galleria mellonella and the nematode Caenorhabditis elegans as models to assess antifungal efficacy during infection by C. krusei. This yeast killed G. mellonella at 25, 30 and 37°C and reduced haemocytic density. Infected larvae melanized in a dose-dependent manner. Fluconazole did not protect against C. krusei infection, in contrast to amphotericin B, voriconazole or caspofungin. However, the doses of these antifungals required to obtain larvae protection were always higher during C. krusei infection than during C. albicans infection. Similar results were found in the model host C. elegans. Our work demonstrates that non mammalian models are useful tools to investigate in vivo antifungal efficacy and virulence of C. krusei. PMID:23555877

  12. Differential Proteome Analysis of a Flor Yeast Strain under Biofilm Formation.

    Science.gov (United States)

    Moreno-García, Jaime; Mauricio, Juan Carlos; Moreno, Juan; García-Martínez, Teresa

    2017-03-28

    Several Saccharomyces cerevisiae strains (flor yeasts) form a biofilm (flor velum) on the surface of Sherry wines after fermentation, when glucose is depleted. This flor velum is fundamental to biological aging of these particular wines. In this study, we identify abundant proteins in the formation of the biofilm of an industrial flor yeast strain. A database search to enrich flor yeast "biological process" and "cellular component" according to Gene Ontology Terminology (GO Terms) and, "pathways" was carried out. The most abundant proteins detected were largely involved in respiration, translation, stress damage prevention and repair, amino acid metabolism (glycine, isoleucine, leucine and arginine), glycolysis/gluconeogenesis and biosynthesis of vitamin B9 (folate). These proteins were located in cellular components as in the peroxisome, mitochondria, vacuole, cell wall and extracellular region; being these two last directly related with the flor formation. Proteins like Bgl2p, Gcv3p, Hyp2p, Mdh1p, Suc2p and Ygp1p were quantified in very high levels. This study reveals some expected processes and provides new and important information for the design of conditions and genetic constructions of flor yeasts for improving the cellular survival and, thus, to optimize biological aging of Sherry wine production.

  13. Rhodosporidium BANNO: Inactivation of yeast phase cells by ultraviolet light and N-methyl-N'-nitro-N-nitrosoguanidine

    International Nuclear Information System (INIS)

    Boettcher, F.; Samsonova, I.A.

    1977-01-01

    The inactivation of stationary phase cells by ultraviolet light (UV) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was examined in eight wild strains of Rhodotorula, six of which are the sporidial yeast phase of Rhodosporidium, a basidiomycetous fungus. It thas been found that (1) the UV-resistance of Rhodosporidium and Rhodotorula yeasts is higher and the MNNG-resistance lower than the resistance of Candida and Hansenula yeasts, (2) the shape of the survival curves is sigmoid in the case of UV and two-phase exponential in the case of MNNG, (3) the mutagen sensitivities but not the inactivation kinetics of the strains are different, (4) the UV- and MNNG-sensitivities for each of the strains are correlated, (5) the relatively high resistance to UV cannot be due to the carotenoid pigments of the cells, (6) mutations to UV-sensitivity can be induced with a high rate, (7) the sigmoidal character of the UV survival curves were reduced or transformed to an exponential shape by the UVS-mutations. (author)

  14. Binary Interactions of Antagonistic Bacteria with Candida albicans Under Aerobic and Anaerobic Conditions.

    Science.gov (United States)

    Benadé, Eliska; Stone, Wendy; Mouton, Marnel; Postma, Ferdinand; Wilsenach, Jac; Botha, Alfred

    2016-04-01

    We used both aerobic and anaerobic liquid co-cultures, prepared with Luria Bertani broth, to study the effect of bacteria on the survival of Candida albicans in the external environment, away from an animal host. The bacteria were represented by Aeromonas hydrophila, Bacillus cereus, Bacillus subtilis, Clostridium, Enterobacter, Klebsiella pneumoniae, Kluyvera ascorbata and Serratia marcescens. Under aerobic conditions, the yeast's growth was inhibited in the presence of bacterial growth; however, under anaerobic conditions, yeast and bacterial growth in co-cultures was similar to that observed for pure cultures. Subsequent assays revealed that the majority of bacterial strains aerobically produced extracellular hydrolytic enzymes capable of yeast cell wall hydrolysis, including chitinases and mannan-degrading enzymes. In contrast, except for the A. hydrophila strain, these enzymes were not detected in anaerobic bacterial cultures, nor was the antimicrobial compound prodigiosin found in anaerobic cultures of S. marcescens. When we suspended C. albicans cells in crude extracellular enzyme preparations from K. pneumoniae and S. marcescens, we detected no negative effect on yeast viability. However, we found that these preparations enhance the toxicity of prodigiosin towards the yeast, especially in combination with mannan-degrading enzymes. Analyses of the chitin and mannan content of yeast cell walls revealed that less chitin was produced under anaerobic than aerobic conditions; however, the levels of mannan, known for its low permeability, remained the same. The latter phenomenon, as well as reduced production of the bacterial enzymes and prodigiosin, may contribute to anaerobic growth and survival of C. albicans in the presence of bacteria.

  15. Ethanol production potential of local yeast strains isolated from ripe ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-16

    May 16, 2008 ... ... of these studies, the preferred candidate for industrial production of ethanol ... The yeast strains were isolated using the method of Ameh et al. (1989), on ... gas in the Durham tube during the incubation period. Fermentation ...

  16. Targeted changes of the cell wall proteome influence Candida albicans ability to form single- and multi-strain biofilms.

    Directory of Open Access Journals (Sweden)

    Vitor Cabral

    2014-12-01

    Full Text Available Biofilm formation is an important virulence trait of the pathogenic yeast Candida albicans. We have combined gene overexpression, strain barcoding and microarray profiling to screen a library of 531 C. albicans conditional overexpression strains (∼10% of the genome for genes affecting biofilm development in mixed-population experiments. The overexpression of 16 genes increased strain occupancy within a multi-strain biofilm, whereas overexpression of 4 genes decreased it. The set of 16 genes was significantly enriched for those encoding predicted glycosylphosphatidylinositol (GPI-modified proteins, namely Ihd1/Pga36, Phr2, Pga15, Pga19, Pga22, Pga32, Pga37, Pga42 and Pga59; eight of which have been classified as pathogen-specific. Validation experiments using either individually- or competitively-grown overexpression strains revealed that the contribution of these genes to biofilm formation was variable and stage-specific. Deeper functional analysis of PGA59 and PGA22 at a single-cell resolution using atomic force microscopy showed that overexpression of either gene increased C. albicans ability to adhere to an abiotic substrate. However, unlike PGA59, PGA22 overexpression led to cell cluster formation that resulted in increased sensitivity to shear forces and decreased ability to form a single-strain biofilm. Within the multi-strain environment provided by the PGA22-non overexpressing cells, PGA22-overexpressing cells were protected from shear forces and fitter for biofilm development. Ultrastructural analysis, genome-wide transcript profiling and phenotypic analyses in a heterologous context suggested that PGA22 affects cell adherence through alteration of cell wall structure and/or function. Taken together, our findings reveal that several novel predicted GPI-modified proteins contribute to the cooperative behaviour between biofilm cells and are important participants during C. albicans biofilm formation. Moreover, they illustrate the power

  17. Effect of menadione and hydrogen peroxide on catalase activity in Saccharomyces yeast strains

    Directory of Open Access Journals (Sweden)

    Nadejda EFREMOVA

    2013-05-01

    Full Text Available It has been studied the possibility of utilization of two important oxidant factors as regulators of catalase activity in Saccharomyces yeasts. In this paper results of the screening of some Saccharomyces yeast strains for potential producers of catalase are presented. Results of the screening for potential catalase producer have revealed that Saccharomyces cerevisiae CNMN-Y-11 strain possesses the highest catalase activity (2900 U/mg protein compared with other samples. Maximum increase of catalase activity with 50-60% compared to the reference sample was established in the case of hydrogen peroxide and menadione utilization in optimal concentrations of 15 and 10 mM. This research has been demonstrated the potential benefits of application of hydrogen peroxide and menadione as stimulatory factors of catalase activity in Saccharomyces yeasts.

  18. Influence of yeast strain, priming solution and temperature on beer bottle conditioning.

    Science.gov (United States)

    Marconi, Ombretta; Rossi, Serena; Galgano, Fernanda; Sileoni, Valeria; Perretti, Giuseppe

    2016-09-01

    Recently, there has been a significant increase in the number of microbreweries. Usually, craft beers are bottle conditioned; however, few studies have investigated beer refermentation. One of the objectives of this study was to evaluate the impacts of different experimental conditions, specifically yeast strain, priming solution and temperature, on the standard quality attributes, the volatile compounds and the sensory profile of the bottle-conditioned beer. The other aim was to monitor the evolution of volatile compounds and amino acids consumption throughout the refermentation process to check if it is possible to reduce the time necessary for bottle conditioning. The results indicate that the volatile profile was mainly influenced by the strain of yeast, and this may have obscured the possible impacts of the other parameters. Our results also confirm that the two yeast strains showed different metabolic activity, particularly with respect to esters production. Moreover, we found the Safbrew S-33® strain when primed with Siromix® and refermented at 30 °C yielded the fastest formation of higher alcohols while maintaining low production of off-flavours. These results suggest a formulation that may reduce the time needed for bottle conditioning without affecting the quality of the final beer which may simultaneously improve efficiency and economic profits. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  19. Multidrug-Resistant Candida

    DEFF Research Database (Denmark)

    Arendrup, Maiken Cavling; Patterson, Thomas F

    2017-01-01

    Invasive Candida infections remain an important cause of morbidity and mortality, especially in hospitalized and immunocompromised or critically ill patients. A limited number of antifungal agents from only a few drug classes are available to treat patients with these serious infections. Resistance...... can be either intrinsic or acquired. Resistance mechanisms are not exchanged between Candida; thus, acquired resistance either emerges in response to an antifungal selection pressure in the individual patient or, more rarely, occur due to horizontal transmission of resistant strains between patients....... Although multidrug resistance is uncommon, increasing reports of multidrug resistance to the azoles, echinocandins, and polyenes have occurred in several Candida species, most notably Candida glabrata and more recently Candida auris. Drivers are overall antifungal use, subtherapeutic drug levels at sites...

  20. High-frequency transformation of a methylotrophic yeast, Candida boidinii, with autonomously replicating plasmids which are also functional in Saccharomyces cerevisiae.

    OpenAIRE

    Sakai, Y; Goh, T K; Tani, Y

    1993-01-01

    We have developed a transformation system which uses autonomous replicating plasmids for a methylotrophic yeast, Candida boidinii. Two autonomous replication sequences, CARS1 and CARS2, were newly cloned from the genome of C. boidinii. Plasmids having both a CARS fragment and the C. boidinii URA3 gene transformed C. boidinii ura3 cells to Ura+ phenotype at frequencies of up to 10(4) CFU/micrograms of DNA. From Southern blot analysis, CARS plasmids seemed to exist in polymeric forms as well as...

  1. Antifungal effects of Lavandula binaludensis and Cuminum cyminum essential oils against Candida albicans strains isolated from patients with recurrent vulvovaginal candidiasis.

    Science.gov (United States)

    Minooeianhaghighi, M H; Sepehrian, L; Shokri, H

    2017-03-01

    Recurrent vulvovaginal candidiasis (RVVC), which affects approximately 5% of women of reproductive age, is defined as 4 or more episodes of symptomatic Candida vaginitis within a year. The purposes of this study were to determine the chemical compositions and antifungal susceptibility of Cuminum cyminum (C. cyminum) and Lavandula binaludensis (L. binaludensis) essential oils and their combination against Candida albicans (C. albicans) strains isolated from patients with RVVC. C. albicans isolates were identified via germ tube test, CHROMagar and RapID Yeast Plus System. The essential oils were obtained by hydrodistillation in a Clevenger apparatus and analyzed by gas chromatography-mass spectroscopy (GC-MS). The broth microdilution method was used as antifungal susceptibility test (CLSI-M27-A3). The GC-MS analysis allowed 13 components to be determined; the main components of C. cyminum and L. binaludensis essential oils were γ-terpinene (21.07%) and 1,8-cineole (71.56%), respectively. L. binaludensis and C. cyminum oils were effective in inhibiting C. albicans growth at mean concentrations of 7.91±1.61μg/mL and 8.00±1.89μg/mL, respectively. In addition, the combination of C. cyminum with L. binaludensis oils were more active causing inhibition in all C. albicans isolates, with concentrations varying from 3.90 to 11.71μg/mL (mean value: 7.22±1.69μg/mL). The results suggested the potential substitution of the antifungal chemicals by C. cyminum and L. binaludensis essential oils as natural inhibitors to control the growth of the most important pathogenic Candida species and alternative therapies for RVVC. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  2. Distribution of yeast species associated with oral lesions in HIV-infected patients in Southwest Uganda.

    LENUS (Irish Health Repository)

    Agwu, Ezera

    2012-04-01

    Oropharyngeal candidiasis remains a significant clinical problem in HIV-infected and AIDS patients in regions of Africa where anti-retroviral therapy isn\\'t readily available. In this study we identified the yeast populations associated with oral lesions in HIV-infected patients in Southwest Uganda who were receiving treatment with nystatin and topical clotrimazole. Samples were taken from 605 patients and 316 (52%) of these yielded yeast growth following incubation on Sabouraud dextrose agar. Samples were subsequently re-plated on CHROMagar Candida medium to facilitate identification of the yeast species present. The majority (56%) of culture-positive samples yielded a mix of two or more species. Candida albicans was present in 87% (274\\/316) of patient samples and accounted for 87% (120\\/138) of single species samples. Candida glabrata, Candida tropicalis and Candida norvegensis were also found in cultures that yielded a single species. No Candida dubliniensis isolates were identified in this population.

  3. Distribution of yeast species associated with oral lesions in HIV-infected patients in Southwest Uganda.

    Science.gov (United States)

    Agwu, Ezera; Ihongbe, John C; McManus, Brenda A; Moran, Gary P; Coleman, David C; Sullivan, Derek J

    2012-04-01

    Oropharyngeal candidiasis remains a significant clinical problem in HIV-infected and AIDS patients in regions of Africa where anti-retroviral therapy isn't readily available. In this study we identified the yeast populations associated with oral lesions in HIV-infected patients in Southwest Uganda who were receiving treatment with nystatin and topical clotrimazole. Samples were taken from 605 patients and 316 (52%) of these yielded yeast growth following incubation on Sabouraud dextrose agar. Samples were subsequently re-plated on CHROMagar Candida medium to facilitate identification of the yeast species present. The majority (56%) of culture-positive samples yielded a mix of two or more species. Candida albicans was present in 87% (274/316) of patient samples and accounted for 87% (120/138) of single species samples. Candida glabrata, Candida tropicalis and Candida norvegensis were also found in cultures that yielded a single species. No Candida dubliniensis isolates were identified in this population.

  4. Genome sequence and physiological analysis of Yamadazyma laniorum f.a. sp. nov. and a reevaluation of the apocryphal xylose fermentation of its sister species, Candida tenuis.

    Science.gov (United States)

    Haase, Max A B; Kominek, Jacek; Langdon, Quinn K; Kurtzman, Cletus P; Hittinger, Chris Todd

    2017-05-01

    Xylose fermentation is a rare trait that is immensely important to the cellulosic biofuel industry, and Candida tenuis is one of the few yeasts that has been reported with this trait. Here we report the isolation of two strains representing a candidate sister species to C. tenuis. Integrated analysis of genome sequence and physiology suggested the genetic basis of a number of traits, including variation between the novel species and C. tenuis in lactose metabolism due to the loss of genes encoding lactose permease and β-galactosidase in the former. Surprisingly, physiological characterization revealed that neither the type strain of C. tenuis nor this novel species fermented xylose in traditional assays. We reexamined three xylose-fermenting strains previously identified as C. tenuis and found that these strains belong to the genus Scheffersomyces and are not C. tenuis. We propose Yamadazyma laniorum f.a. sp. nov. to accommodate our new strains and designate its type strain as yHMH7 (=CBS 14780 = NRRL Y-63967T). Furthermore, we propose the transfer of Candida tenuis to the genus Yamadazyma as Yamadazyma tenuis comb. nov. This approach provides a roadmap for how integrated genome sequence and physiological analysis can yield insight into the mechanisms that generate yeast biodiversity. Published by Oxford University Press on behalf of FEMS 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  5. Formation of In Vitro Mixed-Species Biofilms by Lactobacillus pentosus and Yeasts Isolated from Spanish-Style Green Table Olive Fermentations.

    Science.gov (United States)

    León-Romero, Ángela; Domínguez-Manzano, Jesús; Garrido-Fernández, Antonio; Arroyo-López, Francisco Noé; Jiménez-Díaz, Rufino

    2016-01-15

    The present work details the in vitro interactions between Lactobacillus pentosus and yeast strains isolated from table olive processing to form mixed biofilms. Among the different pairs assayed, the strongest biofilms were obtained from L. pentosus and Candida boidinii strain cocultures. However, biofilm formation was inhibited in the presence of d-(+)-mannose. In addition, biofilm formation by C. boidinii monoculture was stimulated in the absence of cell-cell contact with L. pentosus. Scanning electron microscopy revealed that a sort of "sticky" material formed by the yeasts contributed to substrate adherence. Hence, the data obtained in this work suggest that yeast-lactobacilli biofilms may be favored by the presence of a specific mate of yeast and L. pentosus, and that more than one mechanism might be implicated in the biofilm formation. This knowledge will help in the design of appropriate mixed starter cultures of L. pentosus-yeast species pairs that are able to improve the quality and safety of Spanish-style green table olive processing. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  6. Differentiation between Candida albicans and Candida dubliniensis using hypertonic Sabouraud broth and tobacco agar.

    Science.gov (United States)

    Silveira-Gomes, Fabíola; Sarmento, Dayse Nogueira; Espírito-Santo, Elaine Patrícia Tavares do; Souza, Nádia de Oliveira; Pinto, Thifany Mendes; Marques-da-Silva, Silvia Helena

    2011-01-01

    Opportunistic fungal infections in immunocompromised hosts are caused by Candida species, and the majority of such infections are due to Candida albicans. However, the emerging pathogen Candida dubliniensis demonstrates several phenotypic characteristics in common with C. albicans, such as production of germ tubes and chlamydospores, calling attention to the development of stable resistance to fluconazole in vitro. The aim of this study was to evaluate the performance of biochemistry identification in the differentiating between C. albicans and C. dubliniensis, by phenotyping of yeast identified as C. albicans. Seventy-nine isolates identified as C. albicans by the API system ID 32C were grown on Sabouraud dextrose agar at 30°C for 24-48h and then inoculated on hypertonic Sabouraud broth and tobacco agar. Our results showed that 17 (21.5%) isolates were growth-inhibited on hypertonic Sabouraud broth, a phenotypic trait inconsistent with C. albicans in this medium. However, the results observed on tobacco agar showed that only 9 (11.4%) of the growth-inhibited isolates produced characteristic colonies of C. dubliniensis (rough colonies, yellowish-brown with abundant fragments of hyphae and chlamydospores). The results suggest that this method is a simple tool for screening C. albicans and non-albicans yeast and for verification of automated identification.

  7. Therapeutic activity of a Saccharomyces cerevisiae-based probiotic and inactivated whole yeast on vaginal candidiasis.

    Science.gov (United States)

    Pericolini, Eva; Gabrielli, Elena; Ballet, Nathalie; Sabbatini, Samuele; Roselletti, Elena; Cayzeele Decherf, Amélie; Pélerin, Fanny; Luciano, Eugenio; Perito, Stefano; Jüsten, Peter; Vecchiarelli, Anna

    2017-01-02

    Vulvovaginal candidiasis is the most prevalent vaginal infection worldwide and Candida albicans is its major agent. Vulvovaginal candidiasis is characterized by disruption of the vaginal microbiota composition, as happens following large spectrum antibiotic usage. Recent studies support the effectiveness of oral and local probiotic treatment for prevention of recurrent vulvovaginal candidiasis. Saccharomyces cerevisiae is a safe yeast used as, or for, the production of ingredients for human nutrition and health. Here, we demonstrate that vaginal administration of probiotic Saccharomyces cerevisiae live yeast (GI) and, in part, inactivated whole yeast Saccharomyces cerevisiae (IY), used as post-challenge therapeutics, was able to positively influence the course of vaginal candidiasis by accelerating the clearance of the fungus. This effect was likely due to multiple interactions of Saccharomyces cerevisiae with Candida albicans. Both live and inactivated yeasts induced coaggregation of Candida and consequently inhibited its adherence to epithelial cells. However, only the probiotic yeast was able to suppress some major virulence factors of Candida albicans such as the ability to switch from yeast to mycelial form and the capacity to express several aspartyl proteases. The effectiveness of live yeast was higher than that of inactivated whole yeast suggesting that the synergy between mechanical effects and biological effects were dominant over purely mechanical effects. The protection of epithelial cells to Candida-induced damage was also observed. Overall, our data show for the first time that Saccharomyces cerevisiae-based ingredients, particularly the living cells, can exert beneficial therapeutic effects on a widespread vaginal mucosal infection.

  8. Antifungal Effects of Gold Nanoparticles Conjugated Fluconazole against Fluconazole Resistant Strains of Candida albicans Isolated From Patients with Chronic Vulvovaginitis

    Directory of Open Access Journals (Sweden)

    Mehrdad Memarian

    2016-09-01

    Full Text Available Background and Objectives: A number of women with volvuvaginal candidiasis suffer from certain chronic and recurrent types of this infection that affect their quality of life. Meanwhile, increased use of antifungal drugs, especially azoles, for treatment of chronic candidiasis is an important factor for incidence of drug resistance in Candida isolates from patients with vulvovaginal candidiasis. The aim of this study was to investigate anticandidal effects of gold nanoparticles conjugated fluconazole to develop better drugs for treatment of patients with candidal vaginitis, especially its chronic type. Methods: After collection of 300 vaginal swab specimens and culture and isolation of primary colonies and determination of Candida species, fluconazole resistant strains of Candida albicans were detected using disc diffusion. Finally, antifungal effects of gold nanoparticles conjugated fluconazole and fluconazole were compared by broth microdilution. Results: Only one fluconazole resistant strain of C. albicans was isolated from patients (MIC=64µg/ml. The results obtained from drug susceptibility test showed that this strain was sensitive to gold nanoparticles conjugated fluconazole (MIC=2µg/ml. Conclusion: Given the optimal anticandidal effects of gold nanoparticles conjugated fluconazole on resistant strains of C. albicans, a suitable compound with great anticandidal properties may be achieved in the future.

  9. Antifungal susceptibilities of Candida, Cryptococcus neoformans and Aspergillus fumigatus from the Asia and Western Pacific region: data from the SENTRY antifungal surveillance program (2010-2012).

    Science.gov (United States)

    Pfaller, Michael A; Messer, Shawn A; Jones, Ronald N; Castanheira, Mariana

    2015-09-01

    The SENTRY Antifungal Surveillance Program monitors global susceptibility rates of newer and established antifungal agents. We report the in vitro activity of seven antifungal agents against 496 contemporary clinical isolates of yeasts and molds. The isolates were obtained from 20 laboratories in the Asia-Western Pacific (APAC) region during 2010 through 2012. Anidulafungin, caspofungin, micafungin, fluconazole, itraconazole, posaconazole and voriconazole were susceptibility tested using CLSI methods and species-specific interpretive criteria. Sequencing of fks hot spots was performed for echinocandin-resistant strains. Isolates included 13 species of Candida (n=460), 5 species of non-Candida yeasts (21), 5 species of Aspergillus (11) and 4 other molds. Echinocandin resistance was uncommon among eight species of Candida and was only detected in three isolates of Candida glabrata, two from Australia harboring mutations in fks1 (F625S) and fks2 (S663P). Resistance to the azoles was much more common and was observed among all species with the exception of Candida dubliniensis. Fluconazole resistance rates observed with C. glabrata (6.8%) was comparable to that seen with Candida parapsilosis (5.7%) and Candida tropicalis (3.6%). Cross resistance among the triazoles was seen with each of these three species. The mold-active azoles and the echinocandins were all active against isolates of Aspergillus fumigatus. Azole resistance was not detected among the isolates of Cryptococcus neoformans. Antifungal resistance is uncommon among isolates of fungi causing invasive fungal infections in the APAC region. As in other regions of the world, emerging resistance to the echinocandins among invasive isolates of C. glabrata bears close monitoring.

  10. Production of Xylitol from D-Xylose by Overexpression of Xylose Reductase in Osmotolerant Yeast Candida glycerinogenes WL2002-5.

    Science.gov (United States)

    Zhang, Cheng; Zong, Hong; Zhuge, Bin; Lu, Xinyao; Fang, Huiying; Zhuge, Jian

    2015-07-01

    Efficient bioconversion of D-xylose into various biochemicals is critical for the developing lignocelluloses application. In this study, we compared D-xylose utilization in Candida glycerinogenes WL2002-5 transformants expressing xylose reductase (XYL1) in D-xylose metabolism. C. glycerinogenes WL2002-5 expressing XYL1 from Schefferomyces stipitis can produce xylitol. Xylitol production by the recombinant strains was evaluated using a xylitol fermentation medium with glucose as a co-substrate. As glucose was found to be an insufficient co-substrate, various carbon sources were screened for efficient cofactor regeneration, and glycerol was found to be the best co-substrate. The effects of glycerol on the xylitol production rate by a xylose reductase gene (XYL1)-overexpressed mutant of C. glycerinogenes WL2002-5 were investigated. The XYL1-overexpressed mutant produced xylitol from D-xylose using glycerol as a co-substrate for cell growth and NAD (P) H regeneration: 100 g/L D-xylose was completely converted into xylitol when at least 20 g/L glycerol was used as a co-substrate. XYL1 overexpressed mutant grown on glycerol as co-substrate accumulated 2.1-fold increased xylitol concentration over those cells grown on glucose as co-substrate. XYL1 overexpressed mutant produced xylitol with a volumetric productivity of 0.83 g/L/h, and a xylitol yield of 98 % xylose. Recombinant yeast strains obtained in this study are promising candidates for xylitol production. This is the first report of XYL1 gene overexpression of C. glycerinogenes WL2002-5 for enhancing the efficiency of xylitol production.

  11. BIOLOGICAL PROPERTIES OF STAPHYLOCOCCUS AND YEAST-LIKE FUNGI OF THE GENUS CANDIDA, ISOLATED FROM ONCOLOGICAL PATIENTS

    Directory of Open Access Journals (Sweden)

    Fomina NS

    2012-12-01

    Full Text Available The results of the spectrum of microorganisms, which are the causative agents of infectious complications of the oral cavity in patients with oncological pathology are presented in the article. The sensitivity of isolated clinical strains of microorganisms to antibiotics, antifungal, antiseptic decasan, miramistin, gorosten, septefril is shown. The results of antiseptic resistance formation to staphylococci and Candida to dekasan, miramistin, septefril, gorosten are described.

  12. BIOLOGICAL PROPERTIES OF STAPHYLOCOCCUS AND YEAST-LIKE FUNGI OF THE GENUS CANDIDA, ISOLATED FROM ONCOLOGICAL PATIENTS

    OpenAIRE

    Fomina NS; Fomin OO

    2012-01-01

    The results of the spectrum of microorganisms, which are the causative agents of infectious complications of the oral cavity in patients with oncological pathology are presented in the article. The sensitivity of isolated clinical strains of microorganisms to antibiotics, antifungal, antiseptic decasan, miramistin, gorosten, septefril is shown. The results of antiseptic resistance formation to staphylococci and Candida to dekasan, miramistin, septefril, gorosten are described.

  13. Xylitol production from colombian native yeast strains Producción de xilitol a partir de levaduras nativas colombianas*

    Directory of Open Access Journals (Sweden)

    Vanegas Córdoba Isleny Andrea

    2004-12-01

    Full Text Available Xylitol is an alternative sweetener with similar characteristics to sucrose that has become of great interest, due mainly to its safe use in diabetic patients and those deficient in glucose-6-phosphate-dehydrogenase. Its chemical production is expensive and generates undesirable by-products, whereas biotechnological process, which uses different yeasts genera, is a viable production alternative because it is safer and specific. Colombia has a privilege geographic location and offers a great microbial variety, this can be taken advantage of with academic and commercial goals. Because of this, some native microorganisms with potential to produce xylitol were screened in this work. It were isolated 25 yeasts species, from which was possible to identify 84% by the kit API 20C-AUX. Three yeasts: Candida kefyr, C. tropicalis y C. parapsilosis presented greater capacity to degrade xylose compared to the others, therefore they were selected for the later evaluation of its productive capacity. Discontinuous cellular cultures were developed in shaken flasks at 200 rpm and 35°C by 30 hours, using synthetic media with xylose as carbon source. Xylose consumption and xylitol production were evaluated by thin layer chromatography and high performance liquid chromatography. The maximal efficiency were obtained with Candida kefyr and C. tropicalis (Yp/s 0.5 y 0.43 g/g, respectively, using an initial xylose concentration of 20 g/L. Key words: Xylitol, xylose, yeasts, Candida kefyr, C. tropicalis, C. parapsilosis.* Este artículo corresponde a la presentación oral que obtuvo el tercer lugar en la sala de bioprocesos, bioprospección y ambiental del segundo Congreso Colombiano de Biotecnología. El xilitol es un edulcorante alternativo con características similares a la sacarosa que ha despertado gran interés debido principalmente a su uso seguro en pacientes diabéticos y aquellos deficientes en glucosa-6-fosfato-deshidrogenasa. Su síntesis química es

  14. Metabolomics-based prediction models of yeast strains for screening of metabolites contributing to ethanol stress tolerance

    Science.gov (United States)

    Hashim, Z.; Fukusaki, E.

    2016-06-01

    The increased demand for clean, sustainable and renewable energy resources has driven the development of various microbial systems to produce biofuels. One of such systems is the ethanol-producing yeast. Although yeast produces ethanol naturally using its native pathways, production yield is low and requires improvement for commercial biofuel production. Moreover, ethanol is toxic to yeast and thus ethanol tolerance should be improved to further enhance ethanol production. In this study, we employed metabolomics-based strategy using 30 single-gene deleted yeast strains to construct multivariate models for ethanol tolerance and screen metabolites that relate to ethanol sensitivity/tolerance. The information obtained from this study can be used as an input for strain improvement via metabolic engineering.

  15. Ethanol fermentation from lignocellulosic hydrolysate by a recombinant xylose- and cellooligosaccharide-assimilating yeast strain

    Energy Technology Data Exchange (ETDEWEB)

    Katahira, Satoshi; Fukuda, Hideki [Kobe Univ. (Japan). Div. of Molecular Science; Mizuike, Atsuko; Kondo, Akihiko [Kobe Univ. (Japan). Dept. of Chemical Science and Engineering

    2006-10-15

    The sulfuric acid hydrolysate of lignocellulosic biomass, such as wood chips, from the forest industry is an important material for fuel bioethanol production. In this study, we constructed a recombinant yeast strain that can ferment xylose and cellooligosaccharides by integrating genes for the intercellular expressions of xylose reductase and xylitol dehydrogenase from Pichia stipitis, and xylulokinase from Saccharomyces cerevisiae and a gene for displaying ss-glucosidase from Aspergillus acleatus on the cell surface. In the fermentation of the sulfuric acid hydrolysate of wood chips, xylose and cellooligosaccharides were completely fermented after 36 h by the recombinant strain, and then about 30 g/l ethanol was produced from 73 g/l total sugar added at the beginning. In this case, the ethanol yield of this recombinant yeast was much higher than that of the control yeast. These results demonstrate that the fermentation of the lignocellulose hydrolysate is performed efficiently by the recombinant Saccharomyces strain with abilities for xylose assimilation and cellooligosaccharide degradation. (orig.)

  16. Detection of phospholipase activity of Candida albicans and non albicans isolated from women of reproductive age with vulvovaginal candidiasis in rural area

    Directory of Open Access Journals (Sweden)

    S R Fule

    2015-01-01

    Full Text Available Background: Vulvovaginal candidiasis (VVC is most common accounting for 17 to 39% of symptomatic women. Both Candida albicans and non albicans Candida species are involved in VVC. Amongst various virulence factors proposed for Candida, extracellular phospholipases is one of the virulence factor implicated in its pathogenicity. With this background the present study was carried out to find the prevalence of different Candida species and to detect phospholipase producing strains isolated from symptomatic women with VVC. Materials and Methods: At least two vaginal swabs from 156 women of reproductive age with abnormal vaginal discharge were collected. Direct microscopy and Gram′s stained smear examined for presence of budding yeast and pseudo mycelia followed by isolation and identification of Candida species. Extracellular phospholipase activity was studied by inoculating all isolates on Sabouraud′s dextrose egg yolk agar (SDA medium. Results: Of the 156 women with curdy white discharge alone or in combination with other signs, 59 (37.82% women showed laboratory evidence of VVC. A total of 31 (52.54% women had curdy white discharge followed by 12 (20.33% with other signs and symptoms. C. albicans (62.59% and non albicans Candida (37.28% in a ratio of 1.68:1 were isolated. Of the 37 strains of C. albians 30 (81.08% showed the enzyme activity. Seventeen (56.66% strains showed higher Pz value of < 0.70 (++++. Conclusion: Although there may be typical clinical presentation of Candidiasis. all the patients did not show laboratory evidence of infection. Pregnancy was found to be major risk factor for development of VVC. C. albicans was prevalent species but non albicans species were also frequently isolated. Extracellular phospholipase activity was seen in C. albicans and not in non albicans Candida isolates.

  17. Production of alcohol and edible yeast with extract of carob fruit

    Energy Technology Data Exchange (ETDEWEB)

    Beundia, M; Arroyo, V; Inigo, B; Garrido, J M

    1961-01-01

    Media based on extraction from carob fruit (Ceratonia siliqua) have been used successfully in laboratory production of edible yeast and of alcohol. The fruit is a pod, 25 to 40 g, with sweet meaty flesh containing 34% sugar (dry weight), half sucrose and half invert sugar. Because of butyric acid and tannin, no antimicrobial need be added to the pulp prepared by adding H/sub 2/O (3 times weight) and autoclaving 1 hour in flowing stream. Of 3 yeast spp., Candida pulcherrima, Hansenula anomala, and Rhodotorula rubra, the latter (notable for carotenoid content) produced the most dry material in 48 hours at 32/sup 0/ on a reciprocating shaker with medium containing (NH/sub 4/)/sub 2/SO/sub 4/ 2.52 and extraction contributing 20 g reducing sugar/1. Alcohol fermentation, heretofore effected by natural microflora, was attempted with pure cultures of 4 yeast spp., Saccharomyces cerevisae (4 strains), S. oviformis (2 strains), S. beticus, and S. chevalieri. All were suitable except one strain of S. oviformis. The carob extraction had enough nitrogenous and growth substances so that no other medium ingredient was needed. With reducing sugar level t 23 g/100 mil, alcohol yield was close to the theoretical unitage (13.5) after 17-days growth. The range for the 7 isolates was 10.2 to 12.4. One strain of S. cereviseae reached its maximum, 11.8 in only 7 days.

  18. Candida spp. AISLADAS EN PACIENTES CON VULVOVAGINITIS DE COMUNIDADES RURALES DEL MUNICIPIO CARIPE, ESTADO MONAGAS, VENEZUELA, 2014 | Candida spp. ISOLATED FROM PATIENTS WITH VULVOVAGINITIS OF RURAL COMMUNITIES FROM CARIPE MUNICIPALITY, MONAGAS STATE, VENEZUELA, 2014

    Directory of Open Access Journals (Sweden)

    Druvic Lemus-Espinoza

    2016-11-01

    Full Text Available This study evaluated patients with symptomatic vaginal fungal infection in a rural area of Caripe Municipality, Monagas state, Venezuela, aiming to identify the species involved and their sensibility to antimicotics. Identification of species of Candida yeast was made with the use of CHROMagar Candida® and API AUX 20®. Additionally, in vitro susceptibility to fluconazole was evaluated by the agar diffusion method (CLSI, M44-A2. The prevalence of vaginal candidiasis was 23/86 cases (26.7% among women 15 to 60 years. Candida albicans was the most common species among patients (39.1%. However, other isolated agents within the same genus Candida dominated (65.2% and were identified: Complex C. glabrata (4/23; 17.4%, C. tropicalis (4/23; 17.4%, Complex C. parapsilosis (3/23; 13.1%, C.guilliermondii (2/23; 8.7%, C. krusei (1/23; 4.3% and one episode of mixed infection with C. albicans and C. krusei (1/23. No statistical difference was observed between symptoms; vulvovaginal erythema occurred in all infected women. More than half of the yeasts (15/23 were sensitive to fluconazole. In this population sample, isolates of C. albicans and C. guilliermondii were 100% sensitive to fluconazole, while the C. krusei strain (1/23 isolated from a mixed infection was resistant to this antimicotic. Other species, like C. tropicalis (4/23, C. glabrata (2/23 and Complex C. parapsilosis (1/23 showed dose-dependent susceptibility to fluconazole. In gynecological evaluations of patients from rural or urban communities, with clinical picture of micotic vulvovaginitis, a microbiological study of vaginal secretions should be implemented.

  19. Evaluation of risk factors in patients with vulvovaginal candidiasis and the value of chromID Candida agar versus CHROMagar Candida for recovery and presumptive identification of vaginal yeast species.

    Science.gov (United States)

    Guzel, Ahmet Bariş; Ilkit, Macit; Akar, Tuba; Burgut, Refik; Demir, S Cansun

    2011-01-01

    Vulvovaginal candidiasis (VVC), particularly the recurrent form, remains an intractable problem for clinicians, microbiologists, and patients. It is essential to confirm the clinical diagnosis by mycological methods and avoid empirical therapy. The recovery of yeast in fungal culture, such as on Sabouraud dextrose agar, remains the gold standard for diagnosis. In this investigation, we examined 474 participants, including 122 (25.7%) with acute VVC cases, 249 (52.5%) who had recurrent VVC (RVVC) cases, and 103 (21.7%) healthy controls. We also administered a questionnaire to obtain information on patient lifestyle and medical, gynecological, and sexual history. In addition, we compared the performance of chromID Candida agar (CAN2) to CHROMagar Candida (CAC) and Sabouraud dextrose agar with gentamicin and chloramphenicol (SGC2). The yeasts were identified by conventional methods including the germ tube test, microscopic morphology on cornmeal-Tween 80 agar, and the commercial API 20C AUX system. We detected yeasts in 60 of 122 (49.2%) patients with acute VVC cases, 110 of 249 (44.2%) with RVVC cases, and in 35 of 103 (34%) healthy controls (P = 0.07). A total of 205 samples were found to be positive for fungi (43.2%), of which 176 (85.9%) were monofungal, and 29 (14.1%) were polyfungal. In addition, 198 of these samples (96.6%) were positive on CAN2, 195 (95.1%) on CAC, 189 (92.2%) on SGC2, and 183 (89.3%) samples on all three (P = 0.17). The 234 yeast isolates recovered were C. albicans (n = 118), C. glabrata (n = 82), C. kefyr (n = 11), C. krusei (n = 9), C. lipolytica (n = 3), C. colliculosa (n = 2), C. parapsilosis (n = 2), C. pelliculosa (n = 2), C. tropicalis (n = 2), and other species of Candida (n = 3). Of the 29 polyfungal populations, 28 (96.6%) were detected in CAN2, 25 in (86.2%) CAC, and 25 (86.2%) on both (P = 0.35). Notably, we detected the high predominance of C. albicans+C. glabrata (86.2%) in polyfungal populations. Briefly, the detection of C

  20. Photomimetic effect of serotonin on yeast cells irradiated by far-UV radiation

    International Nuclear Information System (INIS)

    Fraikin, G.Y.; Strakhovskaya, M.G.; Rubin, L.B.

    1982-01-01

    The effect of serotonin on the survival of far-UV irradiated cells of the yeast Candida guilliermondii was studied. Serotonin was found to have a photomimetic property. Preincubation of cells with serotonin results in protection against far-UV inactivation, whereas the post-radiation treatment with serotonin causes a potentiation of far-UV lethality. Both effects are similar to those produced by near-UV (334 nm) radiation. The observations provide support to the previously proposed idea that photosynthesized serotonin is the underlying cause of the two effects of near-UV radiation, photoprotection and potentiation of far-UV lethality. Experiments with an excision-deficient strain of the yeast Saccharomyces cerevisiae suggest that the effect of serotonin is by its binding to DNA. (author)

  1. The yeast spectrum of the 'tea fungus Kombucha'.

    Science.gov (United States)

    Mayser, P; Fromme, S; Leitzmann, C; Gründer, K

    1995-01-01

    The tea fungus 'Kombucha' is a symbiosis of Acetobacter, including Acetobacter xylinum as a characteristic species, and various yeasts. A characteristic yeast species or genus has not yet been identified. Kombucha is mainly cultivated in sugared black tea to produce a slightly acidulous effervescent beverage that is said to have several curative effects. In addition to sugar, the beverage contains small amounts of alcohol and various acids, including acetic acid, gluconic acid and lactic acid, as well as some antibiotic substances. To characterize the yeast spectrum with special consideration given to facultatively pathogenic yeasts, two commercially available specimens of tea fungus and 32 from private households in Germany were analysed by micromorphological and biochemical methods. Yeasts of the genera Brettanomyces, Zygosaccharomyces and Saccharomyces were identified in 56%, 29% and 26% respectively. The species Saccharomycodes ludwigii and Candida kefyr were only demonstrated in isolated cases. Furthermore, the tests revealed pellicle-forming yeasts such as Candida krusei or Issatchenkia orientalis/occidentalis as well as species of the apiculatus yeasts (Kloeckera, Hanseniaspora). Thus, the genus Brettanomyces may be a typical group of yeasts that are especially adapted to the environment of the tea fungus. However, to investigate further the beneficial effects of tea fungus, a spectrum of the other typical genera must be defined. Only three specimens showed definite contaminations. In one case, no yeasts could be isolated because of massive contamination with Penicillium spp. In the remaining two samples (from one household), Candida albicans was demonstrated. The low rate of contamination might be explained by protective mechanisms, such as formation of organic acids and antibiotic substances. Thus, subjects with a healthy metabolism do not need to be advised against cultivating Kombucha. However, those suffering from immunosuppression should preferably

  2. Phytase-producing capacity of yeasts isolated from traditional African fermented food products and PHYPk gene expression of Pichia kudriavzevii strains.

    Science.gov (United States)

    Greppi, Anna; Krych, Łukasz; Costantini, Antonella; Rantsiou, Kalliopi; Hounhouigan, D Joseph; Arneborg, Nils; Cocolin, Luca; Jespersen, Lene

    2015-07-16

    Phytate is known as a strong chelate of minerals causing their reduced uptake by the human intestine. Ninety-three yeast isolates from traditional African fermented food products, belonging to nine species (Pichia kudriavzevii, Saccharomyces cerevisiae, Clavispora lusitaniae, Kluyveromyces marxianus, Millerozyma farinosa, Candida glabrata, Wickerhamomyces anomalus, Hanseniaspora guilliermondii and Debaryomyces nepalensis) were screened for phytase production on solid and liquid media. 95% were able to grow in the presence of phytate as sole phosphate source, P. kudriavzevii being the best growing species. A phytase coding gene of P. kudriavzevii (PHYPk) was identified and its expression was studied during growth by RT-qPCR. The expression level of PHYPk was significantly higher in phytate-medium, compared to phosphate-medium. In phytate-medium expression was seen in the lag phase. Significant differences in gene expression were detected among the strains as well as between the media. A correlation was found between the PHYPk expression and phytase extracellular activity. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Development and Characterization of Complex DNA Fingerprinting Probes for the Infectious Yeast Candida dubliniensis

    Science.gov (United States)

    Joly, Sophie; Pujol, Claude; Rysz, Michal; Vargas, Kaaren; Soll, David R.

    1999-01-01

    Using a strategy to clone large genomic sequences containing repetitive elements from the infectious yeast Candida dubliniensis, the three unrelated sequences Cd1, Cd24, and Cd25, with respective molecular sizes of 15,500, 10,000, and 16,000 bp, were cloned and analyzed for their efficacy as DNA fingerprinting probes. Each generated a complex Southern blot hybridization pattern with endonuclease-digested genomic DNA. Cd1 generated an extremely variable pattern that contained all of the bands of the pattern generated by the repeat element RPS of Candida albicans. We demonstrated that Cd1 does not contain RPS but does contain a repeat element associated with RPS throughout the C. dubliniensis genome. The Cd1 pattern was the least stable over time both in vitro and in vivo and for that reason proved most effective in assessing microevolution. Cd24, which did not exhibit microevolution in vitro, was highly variable in vivo, suggesting in vivo-dependent microevolution. Cd25 was deemed the best probe for broad epidemiological studies, since it was the most stable over time, was the only truly C. dubliniensis-specific probe of the three, generated the most complex pattern, was distributed throughout all C. dubliniensis chromosomes, and separated a worldwide collection of 57 C. dubliniensis isolates into two distinct groups. The presence of a species-specific repetitive element in Cd25 adds weight to the already substantial evidence that C. dubliniensis represents a bona fide species. PMID:10074523

  4. Ethanol production potential of local yeast strains isolated from ripe ...

    African Journals Online (AJOL)

    The ability of different yeast strains isolated from ripe banana peels to produce ethanol was investigated. Of the 8 isolates screened for their fermentation ability, 5 showed enhanced performance and were subsequently identified and assessed for important ethanol fermentation attributes such as ethanol producing ability, ...

  5. Induction of mutation for increased sulfur content in the CFI strain of yeast by gamma-irradiation

    International Nuclear Information System (INIS)

    Faustino, C.C.

    1977-08-01

    From all current source of protein concentration the food yeast offers the greatest potential for development. Yeast protein is a good source of lysine and has adeqouate acounts of other essential amino acids such as trytophan and threonine, however, it was found to be relatively poor in the sulfur-containing amino acids which limits its nutrient value. A lasting remedy is genetic modification of the microorganisms to produce protein with a better amino acid balance. Gamma radiation from Co-60 was tried in these experiments being reported to induce mutations in the new CFI strain. A way of screening for increased sulfur content was devised. These are; 1) Incorporation of (NH 4 ) 2 35 S0 4 into the yeast cells; 2) Autoradiography; and 3) Quantitative determination of S-incorporation in submerse cultures of yeasts by use of a liquid scintillation counter. About seven hundred individual colonies were carefully and meticulously autQradiographically screened for high-S0 4 incorporation. Based on the results of autoradiography, 7.8% (50 strains) of the whole population were considered high in 35 S0 4 incorporation. The 50 yeast strains selected by autoradiography to be high in S0 4 incorporation were analyzed with the use of a liquid scintillation counter. From the data gathered, 29 mutants were se--lected. The data from these 29 mutants are presented in tabulated form. Only yeast strains no. 1, 42, 44, 47, 4, 3, 49, 50, 2 and 39 appear to show any promise as putative high-S mutants

  6. Diversity and killer activity of yeasts in Malaysian fermented food samples.

    Science.gov (United States)

    Lim, S L; Tay, S T

    2011-08-01

    The biodiversity and the killer activity of yeasts isolated from various types of fermented food in Malaysia were investigated in this study. Of 252 yeasts isolated from 48 fermented food samples in this study, 19 yeast species were identified based on sequence analysis of the ITS1-5.8S-ITS2 partial fragments of the yeasts. A total of 29 (11.5%) of the yeast isolates demonstrated killer activity to at least one Candida species tested in this study; including 22 isolates of Trichosporon asahii, 4 isolates of Pichia anomala, and one isolate each of Pichia norvegensis, Pichia fermentans and Issatchenkia orientalis, respectively. The presence of killer yeasts reflects antagonism that occurs during microbial interaction in the fermented food, whereby certain yeasts produce killer toxins and possibly other toxic substances in competition for limited nutrients and space. The anti-Candida activity demonstrated by killer yeasts in this study should be further explored for development of alternative therapy against candidiasis.

  7. Different commercial yeast strains affecting the volatile and sensory profile of cava base wine.

    Science.gov (United States)

    Torrens, Jordi; Urpí, Pilar; Riu-Aumatell, Montserrat; Vichi, Stefania; López-Tamames, Elvira; Buxaderas, Susana

    2008-05-10

    36 semi-industrial fermentations were carried out with 6 different yeast strains in order to assess differences in the wines' chemical and volatile profile. Two of the tested strains (Y3 and Y6) showed the fastest fermentation rates throughout 3 harvests and on 2 grape varieties. The wines fermented by three of the tested strains (Y5, Y3 and Y4) stand out for their high amounts of esters and possessed the highest fruity character. Wines from strains producing low amounts of esters and high concentrations of medium chain fatty acids, higher alcohols and six-carbon alcohols were the least appreciated at the sensory analysis. The data obtained in the present study show how the yeast strain quantitatively affects the final chemical and volatile composition of cava base wines and have repercussions on their sensory profile, independently of must variety and harvest year.

  8. THE DEVELOPMENT OF BIOCHEMICAL OXYGEN DEMAND SENSOR USING LOCAL YEAST: Candida fukuyamaensis, UICC Y-247

    Directory of Open Access Journals (Sweden)

    Endang Saepudin

    2011-04-01

    Full Text Available In order to shorten the measurement time of biochemical oxygen demand (BOD, a BOD sensor based on yeastmetabolism was developed. Local yeast, Indonesian Origin, Candida fukuyamaensis UICC Y-247, was used as atransducer. The yeast was immobilized as a thin film in agarose matrix with the auxiliary of Nafion® acting as themembrane for ion exchange process. The film was then attached to gold-modified glassy carbons and used as transduceron the working electrodes. The measurements were conducted by observing the depletion of glucose concentrationusing multipulse amperometric method and then converted to BOD values. Optimum condition was observed in awaiting measurement time of 30 min at an applied potential of 450 mV (vs. Ag/AgCl. Linearity was shown in glucoseconcentration range of 0.1–0.5 mM, which was equivalent to BOD concentration range of 10–50 mg/L. A detectionlimit of 1.13 mg/L BOD could be achieved. Good repeatability was shown by a relative standard deviation (RSD of2.7% (n = 15. However, decreasing current response of ~50% was found after 3 days. Comparing to the conventionalBOD measurement, this BOD sensor can be used as an alternative method for BOD measurements.

  9. Differing effects of 2 active dried yeast (Saccharomyces cerevisiae) strains on ruminal acidosis and methane production in nonlactating dairy cows.

    Science.gov (United States)

    Chung, Y-H; Walker, N D; McGinn, S M; Beauchemin, K A

    2011-05-01

    Fifteen ruminally cannulated, nonlactating Holstein cows were used to measure the effects of 2 strains of Saccharomyces cerevisiae, fed as active dried yeasts, on ruminal pH and fermentation and enteric methane (CH(4)) emissions. Nonlactating cows were blocked by total duration (h) that their ruminal pH was below 5.8 during a 6-d pre-experimental period. Within each block, cows were randomly assigned to control (no yeast), yeast strain 1 (Levucell SC), or yeast strain 2 (a novel strain selected for enhanced in vitro fiber degradation), with both strains (Lallemand Animal Nutrition, Montréal, QC, Canada) providing 1 × 10(10) cfu/head per day. Cows were fed once daily a total mixed ration consisting of a 50:50 forage to concentrate ratio (dry matter basis). The yeast strains were dosed via the rumen cannula daily at the time of feeding. During the 35-d experiment, ruminal pH was measured continuously for 7 d (d 22 to 28) by using an indwelling system, and CH(4) gas was measured for 4 d (d 32 to 35) using the sulfur hexafluoride tracer gas technique (with halters and yokes). Rumen contents were sampled on 2 d (d 22 and 26) at 0, 3, and 6h after feeding. Dry matter intake, body weight, and apparent total-tract digestibility of nutrients were not affected by yeast feeding. Strain 2 decreased the average daily minimum (5.35 vs. 5.65 or 5.66), mean (5.98 vs. 6.24 or 6.34), and maximum ruminal pH (6.71 vs. 6.86 or 6.86), and prolonged the time that ruminal pH was below 5.8 (7.5 vs. 3.3 or 1.0 h/d) compared with the control or strain 1, respectively. The molar percentage of acetate was lower and that of propionate was greater in the ruminal fluid of cows receiving strain 2 compared with cows receiving no yeast or strain 1. Enteric CH(4) production adjusted for intake of dry matter or gross energy, however, did not differ between either yeast strain compared with the control but it tended to be reduced by 10% when strain 2 was compared with strain 1. The study shows that

  10. [The evaluation of relationship between the origin of Candida sp. and the ability of biofilm formation on surface of different biomaterials].

    Science.gov (United States)

    Ciok-Pater, Emilia; Gospodarek, Eugenia; Prazyńska, Małgorzata; Bogiel, Tomasz

    2009-01-01

    The increase of fungal infections in recent years is connected with the progress in medicine. The vast usage of biomaterials is an inseparable element of contemporary medicine but it also leads to development of infections. The ability to produce biofilm by those yeasts plays an important role in the pathogenesis of candidiasis. Candida biofilm can form on the surface of plastic materials (silicon, polychloride vinyl, polymethacrylate methyl) used to catheters, drains and dentures production that is why it is a serious problem in case of fungal infections in patients who during the diagnosis and treatment have contact with biomaterials. The aim of the study was the assessment of ability to form biofilm on the surface of different biomaterials (latex silicon, polychloride vinyl, polystyrene, nylon and polymethacrylate methyl). 150 strains of Candida sp. were examined: 85 (56.7%) C. albicans and 65 (43.3%) C. non-albicans. The examined yeasts produced biofilm on the surface of polymethacrylate methyl in 39.3%, latex silicone in 38.7%, polychloride vinyl in 38.0%, polystyrene in 35.3% and nylon in 30.7%. Biofilm was most frequently produced by the strains of C. albicans, C. tropicalis, C. glabrata, C. parapsilosis, C. krusei and C. lusitaniae species.

  11. Isolation and identification of mold and yeast in medombae, a rice wine starter culture from Kompong Cham Province, Cambodia

    Directory of Open Access Journals (Sweden)

    Chay, C.,

    2017-07-01

    Full Text Available Medombae is a dried starter culture used for traditional rice wine processing in Cambodia. However, studies on the role of mold and yeast present and their efficacy for rice wine fermentation are still limited. Cultural and morphological tests revealed that the isolated representative mold strains were isolated based on the method of identification used as Mucor spp and Rhizopus oryzae. On the other hand, the biochemical properties of the first yeast isolate using the Vitek 2 identification system and YST Card identification suggests its identity as Candida tropicalis. The second yeast strain examined for its morphological and cultural characteristic using agar slide technique, and its protein profile which was compared to the reference and sample protein masses using Biomerieux Vitek MS (MALD-TOF showed the presence of Saccharomyces cerevisiae. The biochemical characteristics and cellular characteristics of the third yeast isolate as described by Lodder (1970 and Kreger-Van Rij (1984 confirmed its identity as Saccharomycopsis spp. The DNA test of identification of the isolates should be conducted to further confirm the identity of the isolates.

  12. Bio-Technological Characterization of the Saccharomyces bayanus Yeast Strains in Order to Preserve the Local Specificity

    Directory of Open Access Journals (Sweden)

    Enikő Gaspar

    2011-05-01

    Full Text Available The wine yeasts have multiple and important applications in the industry, aiming to obtain pure cultures and the selection of those strains which, according to the lab investigations, present superior bio-technological properties. In this study we monitored three types of Saccharomyces bayanus yeast strains, isolated from indigenous grapes varieties, Apold Iordana, Italian Blaj Riesling and Royal Feteasca from Jidvei area, which are present in the collection of the Biotechnologies and Microbiology Research Center of SAIAPM University. The yeast strains were subject to alcoholic fermentation in malt must at different temperatures, in the presence of alcohol, sugar and SO2 in various concentrations. The obtained results led to selecting of those strains which had best results regarding the alcoholic tolerance, osmo-tolerance, fermentation speed under stress conditions and resistance to SO2. These results can have practical applications in using the indigenous strains, isolated from grapes which are from inside the country, so that we preserve the local specificity, and reduce imports regarding this area.

  13. Plants’ Natural Products as Alternative Promising Anti-Candida Drugs

    Science.gov (United States)

    Soliman, Sameh; Alnajdy, Dina; El-Keblawy, Ali A.; Mosa, Kareem A.; Khoder, Ghalia; Noreddin, Ayman M.

    2017-01-01

    Candida is a serious life-threatening pathogen, particularly with immunocompromised patients. Candida infections are considered as a major cause of morbidity and mortality in a broad range of immunocompromised patients. Candida infections are common in hospitalized patients and elderly people. The difficulty to eradicate Candida infections is owing to its unique switch between yeast and hyphae forms and more likely to biofilm formations that render resistance to antifungal therapy. Plants are known sources of natural medicines. Several plants show significant anti-Candida activities and some of them have lower minimum inhibitory concentration, making them promising candidates for anti-Candida therapy. However, none of these plant products is marketed for anti-Candida therapy because of lack of sufficient information about their efficacy, toxicity, and kinetics. This review revises major plants that have been tested for anti-Candida activities with recommendations for further use of some of these plants for more investigation and in vivo testing including the use of nanostructure lipid system. PMID:28989245

  14. Distinct stages during colonization of the mouse gastrointestinal tract by Candida albicans

    Directory of Open Access Journals (Sweden)

    Daniel ePrieto

    2015-08-01

    Full Text Available Candida albicans is a member of the human microbiota, colonizing both the vaginal and gastrointestinal tracts. This yeast is devoid of a life style outside the human body and the mechanisms underlying the adaptation to the commensal status remain to be determined. Using a model of mouse gastrointestinal colonization, we show here that C. albicans stably colonizes the mouse gut in about 3 days starting from a dose as low as 100 cells, reaching steady levels of around 107 cells/g of stools. Using fluorescent labeled strains we have assessed the competition between isogenic populations from different sources in cohoused animals. We show that long term (15 days colonizing cells have increased fitness in the gut niche over those grown in vitro or residing in the gut for 1-3 days. Therefore, two distinct states, proliferation and adaptation, seem to exist in the adaptation of this fungus to the mouse gut, a result with potential significance in the prophylaxis and treatment of Candida infections.

  15. Growth-dependent secretome of Candida utilis

    NARCIS (Netherlands)

    Buerth, C.; Heilmann, C.J.; Klis, F.M.; de Koster, C.G.; Ernst, J.F.; Tielker, D.

    2011-01-01

    Recently, the food yeast Candida utilis has emerged as an excellent host for production of heterologous proteins. Since secretion of the recombinant product is advantageous for its purification, we characterized the secreted proteome of C. utilis. Cells were cultivated to the exponential or

  16. Susceptibility and molecular characterization of Candida species from patients with vulvovaginitis

    Directory of Open Access Journals (Sweden)

    Gheniffer Fornari

    2016-06-01

    Full Text Available Abstract Vulvovaginal candidiasis affects women of reproductive age, which represents approximately 15–25% of vaginitis cases. The present study aimed to isolate and characterize yeast from the patients irrespective of the presentation of clinical symptoms. The isolates were subjected to in vitro susceptibility profile and characterization by molecular markers, which intended to assess the distribution of species. A total of 40 isolates were obtained and identified through the CHROMagar, API20aux and by ITS and D1/D2 regions sequencing of DNAr gene. Candida albicans strains were genotyped by the ABC system and the isolates were divided into two genotypic groups. The identity of the C. albicans, C. glabrata, C. guilliermondii, C. kefyr and Saccharomyces cerevisiae isolates was confirmed by the multilocus analysis. The strains of Candida, isolated from patients with complications, were found to be resistant to nystatin but sensitive to fluconazole, amphotericin B and ketoconazole, as observed by in vitro sensitivity profile. The isolates from asymptomatic patients, i.e., the colonized group, showed a dose-dependent sensitivity to the anti-fungal agents, fluconazole and amphotericin B. However, the isolates of C. albicans that belong to distinct genotypic groups showed the same in vitro susceptibility profile.

  17. Susceptibility and molecular characterization of Candida species from patients with vulvovaginitis.

    Science.gov (United States)

    Fornari, Gheniffer; Vicente, Vania Aparecida; Gomes, Renata Rodrigues; Muro, Marisol Dominguez; Pinheiro, Rosangela Lameira; Ferrari, Carolina; Herkert, Patricia Fernanda; Takimura, Marcos; Carvalho, Newton Sérgio de; Queiroz-Telles, Flavio

    2016-01-01

    Vulvovaginal candidiasis affects women of reproductive age, which represents approximately 15-25% of vaginitis cases. The present study aimed to isolate and characterize yeast from the patients irrespective of the presentation of clinical symptoms. The isolates were subjected to in vitro susceptibility profile and characterization by molecular markers, which intended to assess the distribution of species. A total of 40 isolates were obtained and identified through the CHROMagar, API20aux and by ITS and D1/D2 regions sequencing of DNAr gene. Candida albicans strains were genotyped by the ABC system and the isolates were divided into two genotypic groups. The identity of the C. albicans, C. glabrata, C. guilliermondii, C. kefyr and Saccharomyces cerevisiae isolates was confirmed by the multilocus analysis. The strains of Candida, isolated from patients with complications, were found to be resistant to nystatin but sensitive to fluconazole, amphotericin B and ketoconazole, as observed by in vitro sensitivity profile. The isolates from asymptomatic patients, i.e., the colonized group, showed a dose-dependent sensitivity to the anti-fungal agents, fluconazole and amphotericin B. However, the isolates of C. albicans that belong to distinct genotypic groups showed the same in vitro susceptibility profile. Copyright © 2016. Published by Elsevier Editora Ltda.

  18. Differentiation between Candida albicans and Candida dubliniensis using hypertonic Sabouraud broth and tobacco agar

    Directory of Open Access Journals (Sweden)

    Fabíola Silveira-Gomes

    2011-08-01

    Full Text Available INTRODUCTION: Opportunistic fungal infections in immunocompromised hosts are caused by Candida species, and the majority of such infections are due to Candida albicans. However, the emerging pathogen Candida dubliniensis demonstrates several phenotypic characteristics in common with C. albicans, such as production of germ tubes and chlamydospores, calling attention to the development of stable resistance to fluconazole in vitro. The aim of this study was to evaluate the performance of biochemistry identification in the differentiating between C. albicans and C. dubliniensis, by phenotyping of yeast identified as C. albicans. METHODS: Seventy-nine isolates identified as C. albicans by the API system ID 32C were grown on Sabouraud dextrose agar at 30°C for 24-48h and then inoculated on hypertonic Sabouraud broth and tobacco agar. RESULTS: Our results showed that 17 (21.5% isolates were growth-inhibited on hypertonic Sabouraud broth, a phenotypic trait inconsistent with C. albicans in this medium. However, the results observed on tobacco agar showed that only 9 (11.4% of the growth-inhibited isolates produced characteristic colonies of C. dubliniensis (rough colonies, yellowish-brown with abundant fragments of hyphae and chlamydospores. CONCLUSIONS: The results suggest that this method is a simple tool for screening C. albicans and non-albicans yeast and for verification of automated identification.

  19. Identification of Candida albicans and Candida dubliniensis Species Isolated from Bronchoalveolar Lavage Samples Using Genotypic and Phenotypic Methods

    Directory of Open Access Journals (Sweden)

    Sahar Kianipour

    2018-01-01

    Full Text Available Background: Candida dubliniensis is a newly diagnosed species very similar to Candida albicans phenotypically and first discovered in the mouth of people with AIDS in 1995. Among the different phenotypic and genotypic methods, a cost-effective method should be selected which makes it possible to differentiate these similar species. Materials and Methods: Polymerase chain reaction (PCR-restriction fragment length polymorphism with MspI enzyme and the Duplex-PCR method were done by DNA extraction using boiling. The sequencing of the amplified ribosomal region was used to confirm the C. dubliniensis species. Direct examination and colony count of the yeasts were applied for bronchoalveolar lavage (BAL samples and the growth rate of the yeasts were studied at 45°C. To understand the ability formation of chlamydoconidia in yeast isolates, they were separately cultured on the sunflower seed agar, wheat flour agar, and corn meal agar media. Results: Fifty-nine (49.2% yeast colonies were identified from the total of 120 BAL specimens. Twenty-nine isolated yeasts; including 17 (58.6% of C. albicans/dubliniensis complex and 12 (41.4% of nonalbicans isolates produced pseudohypha or blastoconidia in direct smear with a mean colony count of 42000 CFU/mL. C. albicans with the frequency of 15 (42.9% were the most common isolated yeasts, whereas C. dubliniensis was identified in two nonHIV patients. Conclusion: Sequencing of the replicated gene fragment is the best method for identifying the yeasts, but the determination of the species by phenotypic methods such as the creation of chlamydoconidia in sunflower seeds agar and wheat flour agar media can be cost-effective, have sensitivity and acceptable quality.

  20. Identification of Candida albicans and Candida dubliniensis Species Isolated from Bronchoalveolar Lavage Samples Using Genotypic and Phenotypic Methods.

    Science.gov (United States)

    Kianipour, Sahar; Ardestani, Mohammad Emami; Dehghan, Parvin

    2018-01-01

    Candida dubliniensis is a newly diagnosed species very similar to Candida albicans phenotypically and first discovered in the mouth of people with AIDS in 1995. Among the different phenotypic and genotypic methods, a cost-effective method should be selected which makes it possible to differentiate these similar species. Polymerase chain reaction (PCR)-restriction fragment length polymorphism with MspI enzyme and the Duplex-PCR method were done by DNA extraction using boiling. The sequencing of the amplified ribosomal region was used to confirm the C. dubliniensis species. Direct examination and colony count of the yeasts were applied for bronchoalveolar lavage (BAL) samples and the growth rate of the yeasts were studied at 45°C. To understand the ability formation of chlamydoconidia in yeast isolates, they were separately cultured on the sunflower seed agar, wheat flour agar, and corn meal agar media. Fifty-nine (49.2%) yeast colonies were identified from the total of 120 BAL specimens. Twenty-nine isolated yeasts; including 17 (58.6%) of C. albicans / dubliniensis complex and 12 (41.4%) of nonalbicans isolates produced pseudohypha or blastoconidia in direct smear with a mean colony count of 42000 CFU/mL. C. albicans with the frequency of 15 (42.9%) were the most common isolated yeasts, whereas C. dubliniensis was identified in two nonHIV patients. Sequencing of the replicated gene fragment is the best method for identifying the yeasts, but the determination of the species by phenotypic methods such as the creation of chlamydoconidia in sunflower seeds agar and wheat flour agar media can be cost-effective, have sensitivity and acceptable quality.

  1. Integrative Expression of Glucoamylase Gene in a Brewer’s Yeast Saccharomyces pastorianus Strain

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    Guangyi Zhang

    2008-01-01

    Full Text Available The recombinant brewer’s yeast Saccharomyces pastorianus strain was constructed byintroducing the ilv2:GLA fragment released from pMGI6, carrying glucoamylase gene (GLA and using the yeast α-acetolactate synthase gene (ILV2 as the recombination sequence. The strain was able to utilise starch as the sole carbon source, its glucoamylase activity was 6.3 U/mL and its α-acetolactate synthase activity was lowered by 33.3 %. The introduced GLA gene was integrated at the recipient genomic ILV2 gene, one copy of ILV2 gene was disrupted and the other copy remained intact. Primary wort fermentation test confirmed that the diacetyl and residual sugar concentration in the wort fermented by the recombinant strain were reduced by 65.6 and 34.2 % respectively, compared to that of the recipient strain. Under industrial operating conditions, the maturation time of beer fermented by the recombinant strain was reduced from 7 to 4 days, there were no significant differences in the appearance and mouthfeel, and the beer satisfied the high quality demands. That is why the strain could be used in beer production safely.

  2. Pyruvate Decarboxylase Activity Assay in situ of Different Industrial Yeast Strains

    Directory of Open Access Journals (Sweden)

    Dorota Kręgiel

    2009-01-01

    Full Text Available Cytoplasmic pyruvate decarboxylase (PDC, EC 4.1.1.1 is one of the key enzymes of yeast fermentative metabolism. PDC is the first enzyme which, under anaerobic conditions, leads to decarboxylation of pyruvate with acetaldehyde as the end product. The aim of this study is to develop a suitable method for PDC activity assay in situ for different industrial yeast strains. Saccharomyces sp. and Debaryomyces sp. yeast strains grew in fermentative medium with 12 % of glucose. Enzymatic assay was conducted in cell suspension treated with digitonin as permeabilisation agent, and with sodium pyruvate as a substrate, at temperature of 30 °C. Metabolites of PDC pathway were detected using gas chromatographic (GC technique. Various parameters like type and molar concentration of the substrate, minimal effective mass fraction of digitonin, cell concentration, reaction time and effect of pyrazole (alcohol dehydrogenase inhibitor were monitored to optimize PDC enzymatic assay in situ. In the concentration range of yeast cells from 1⋅10^7 to 1⋅10^8 per mL, linear correlation between the produced acetaldehyde and cell density was noticed. Only pyruvate was the specific substrate for pyruvate decarboxylase. In the presence of 0.05 M sodium pyruvate and 0.05 % digitonin, the enzymatic reaction was linear up to 20 min of the assay. During incubation, there was no formation of ethanol and, therefore, pyrazole was not necessary for the assay.

  3. Melanin production by a yeast strain XJ5-1 of Aureobasidium melanogenum isolated from the Taklimakan desert and its role in the yeast survival in stress environments.

    Science.gov (United States)

    Jiang, Hong; Liu, Nan-Nan; Liu, Guang-Lei; Chi, Zhe; Wang, Jian-Ming; Zhang, Ly-Ly; Chi, Zhen-Ming

    2016-07-01

    The yeast strain XJ5-1 isolated from the Taklimakan desert soil was identified to be a strain of Aureobasdium melanogenum and could produce a large amount of melanin when it was grown in the PDA medium, but its melanin biosynthesis and expression of the PKS gene responsible for the melanin biosynthesis was significantly repressed in the presence of (NH4)2SO4. However, A. melanogenum P5 strain isolated from a mangrove ecosystem grown in both the presence and the absence of (NH4)2SO4 did not produce any melanin. The cell size of A. melanogenum XJ5-1 strain was much higher than that of A. melanogenum P5 strain. The melanized cells of the yeast strain XJ5-1 had higher tolerance to UV radiation, oxidation (200.0 mM H2O2), heat treatment (40 °C), salt shock (200.0 g/L NaCl), desiccation and strong acid hydrolysis (6.0 M HCl) at high temperature (80 °C) than the non-melanized cells of the same yeast strain XJ5-1. At the same time, the melanized cells of the yeast strain XJ5-1 also had higher tolerance to UV radiation, oxidation (200.0 mM H2O2), desiccation and strong acid hydrolysis (6.0 M HCl) at high temperature (80 °C) than A. melanogenum P5 strain, but had similar resistance to heat treatment (40 °C) and salt shock (200.0 g/L NaCl) compared to those of A. melanogenum P5 strain. All the results revealed that many characteristics of A. melanogenum XJ5-1 isolated from the Taklimakan desert soil was different from those of A. melanogenum P5 strain isolated from the mangrove ecosystem.

  4. The first cases of Candida auris candidaemia in Oman.

    Science.gov (United States)

    Mohsin, Jalila; Hagen, Ferry; Al-Balushi, Zainab A M; de Hoog, G Sybren; Chowdhary, Anuradha; Meis, Jacques F; Al-Hatmi, Abdullah M S

    2017-09-01

    Candida auris has been recognised as a problematic healthcare-associated emerging yeast which is often misidentified as Candida haemulonii by commercial systems. Correct early identification of C. auris is important for appropriate antifungal treatment and implementing effective infection control measures. Here we report emergence of the first C. auris cases in Oman, initially misidentified as C. haemulonii. © 2017 Blackwell Verlag GmbH.

  5. Competition assays and physiological experiments of soil and phyllosphere yeasts identify Candida subhashii as a novel antagonist of filamentous fungi.

    Science.gov (United States)

    Hilber-Bodmer, Maja; Schmid, Michael; Ahrens, Christian H; Freimoser, Florian M

    2017-01-05

    While recent advances in next generation sequencing technologies have enabled researchers to readily identify countless microbial species in soil, rhizosphere, and phyllosphere microbiomes, the biological functions of the majority of these species are unknown. Functional studies are therefore urgently needed in order to characterize the plethora of microorganisms that are being identified and to point out species that may be used for biotechnology or plant protection. Here, we used a dual culture assay and growth analyses to characterise yeasts (40 different isolates) and their antagonistic effect on 16 filamentous fungi; comprising plant pathogens, antagonists, and saprophytes. Overall, this competition screen of 640 pairwise combinations revealed a broad range of outcomes, ranging from small stimulatory effects of some yeasts up to a growth inhibition of more than 80% by individual species. On average, yeasts isolated from soil suppressed filamentous fungi more strongly than phyllosphere yeasts and the antagonistic activity was a species-/isolate-specific property and not dependent on the filamentous fungus a yeast was interacting with. The isolates with the strongest antagonistic activity were Metschnikowia pulcherrima, Hanseniaspora sp., Cyberlindnera sargentensis, Aureobasidium pullulans, Candida subhashii, and Pichia kluyveri. Among these, the soil yeasts (C. sargentensis, A. pullulans, C. subhashii) assimilated and/or oxidized more di-, tri- and tetrasaccharides and organic acids than yeasts from the phyllosphere. Only the two yeasts C. subhashii and M. pulcherrima were able to grow with N-acetyl-glucosamine as carbon source. The competition assays and physiological experiments described here identified known antagonists that have been implicated in the biological control of plant pathogenic fungi in the past, but also little characterised species such as C. subhashii. Overall, soil yeasts were more antagonistic and metabolically versatile than yeasts from

  6. Prevalence of Candida species in the oral cavity of patients with ...

    African Journals Online (AJOL)

    During the past two decades, there has been a significant increase in the prevalence of fungal infections caused by Candida species. Oral candidiasis is a common opportunistic infection of the oral cavity caused by yeast fungi of the genus Candida on the mucous membranes of the mouth. To isolate and determine the ...

  7. Prevalence of Candida species in the oral cavity of patients with ...

    African Journals Online (AJOL)

    user

    2011-04-11

    Apr 11, 2011 ... During the past two decades, there has been a significant increase in the prevalence of fungal infections caused by Candida species. Oral candidiasis is a common opportunistic infection of the oral cavity caused by yeast fungi of the genus Candida on the mucous membranes of the mouth. To isolate.

  8. Use of antifungal principles from garlic for the Inhibition of yeasts and moulds in fermenting green olives.

    Directory of Open Access Journals (Sweden)

    Asehraou, A.

    1997-04-01

    Full Text Available Yeast contamination of fermented green olives was evaluated. Plate counts were determined during the fermentation process and strains were isolated, identified and characterized. Results showed that counts of yeasts reached a maximum when the acidity was rather high. Strain identification showed that: Pichia anomala, Debaryomyces hansenii, Candida versatilis and C. tropicalis were the most abundant species. Isolates of these species were used in the in-vitro inhibition assays using laboratory media with whole garlic, water extract and steam distilled oil to determine the Minimal Inhibitory Concentrations (MICs. The effect of concentrations that inhibited yeasts and moulds were also studied on lactic acid bacteria which were not inhibited. The essential oil was the most active on growth of moulds and yeasts. The same concentrations of sorbic acid were used in olive preservation against yeasts and moulds during the fermentation and storage. A net decrease in yeast counts was observed.

    En el trabajo se evalúa la contaminación por levaduras en la fermentación de aceitunas verdes. Se hicieron recuentos en placas, y se aislaron, identificaron y caracterizaron las cepas correspondientes. Los resultados indican que los recuentos de mohos alcanzan el máximo cuando la acidez es elevada. Las especies más abundantes fueron: Pichia anomala, Debaryomyces hansenii, Candida versatilis y C. tropicalis. Las especies anteriores se usaron en ensayos de inhibición in vitro utilizando medios de cultivos con ajo, extracto acuoso y aceites obtenidos por arrastre de vapor, determinándose las concentraciones de inhibición mínima (MICs. Las concentraciones que mostraron actividad no tuvieron inhibición frente a las bacterias lácticas. El aceite esencial fue la composición más activa frente a mohos y levaduras. La utilización adicional de ácido sórbico durante la fermentación y almacenamiento dio lugar a un descenso en la

  9. Monitoring of Yeast Communities and Volatile Flavor Changes During Traditional Korean Soy Sauce Fermentation.

    Science.gov (United States)

    Song, Young-Ran; Jeong, Do-Youn; Baik, Sang-Ho

    2015-09-01

    Flavor development in soy sauce is significantly related to the diversity of yeast species. Due to its unique fermentation with meju, the process of making Korean soy sauce gives rise to a specific yeast community and, therefore, flavor profile; however, no detailed analysis of the identifying these structure has been performed. Changes in yeast community structure during Korean soy sauce fermentation were examined using both culture-dependent and culture-independent methods with simultaneous analysis of the changes in volatile compounds by GC-MS analysis. During fermentation, Candida, Pichia, and Rhodotorula sp. were the dominant species, whereas Debaryomyces, Torulaspora, and Zygosaccharomyces sp. were detected only at the early stage. In addition, Cryptococcus, Microbotryum, Tetrapisispora, and Wickerhamomyces were detected as minor strains. Among the 62 compounds identified in this study, alcohols, ketones, and pyrazines were present as the major groups during the initial stages, whereas the abundance of acids with aldehydes increased as the fermentation progressed. Finally, the impacts of 10 different yeast strains found to participate in fermentation on the formation of volatile compounds were evaluated under soy-based conditions. It was revealed that specific species produced different profiles of volatile compounds, some of which were significant flavor contributors, especially volatile alcohols, aldehydes, esters, and ketones. © 2015 Institute of Food Technologists®

  10. Filtration, haze and foam characteristics of fermented wort mediated by yeast strain.

    Science.gov (United States)

    Douglas, P; Meneses, F J; Jiranek, V

    2006-01-01

    To investigate the influence of the choice of yeast strain on the haze, shelf life, filterability and foam quality characteristics of fermented products. Twelve strains were used to ferment a chemically defined wort and hopped ale or stout wort. Fermented products were assessed for foam using the Rudin apparatus, and filterability and haze characteristics using the European Brewing Convention methods, to reveal differences in these parameters as a consequence of the choice of yeast strain and growth medium. Under the conditions used, the choice of strain of Saccharomyces cerevisiae effecting the primary fermentation has an impact on all of the parameters investigated, most notably when the fermentation medium is devoid of macromolecular material. The filtration of fermented products has a large cost implication for many brewers and wine makers, and the haze of the resulting filtrate is a key quality criterion. Also of importance to the quality of beer and some wines is the foaming and head retention of these beverages. The foam characteristics, filterability and potential for haze formation in a fermented product have long been known to be dependant on the raw materials used, as well as other production parameters. The choice of Saccharomyces cerevisiae strain used to ferment has itself been shown here to influence these parameters.

  11. Direct impression on agar surface as a diagnostic sampling procedure for candida balanitis.

    Science.gov (United States)

    Lisboa, Carmen; Santos, António; Azevedo, Filomena; Pina-Vaz, Cidália; Rodrigues, Acácio Gonçalves

    2010-02-01

    The diagnosis of candida balanitis should be based upon both clinical and mycological data. The procedure of material collection is a critical issue to confirm or rule out the clinical diagnosis of candida balanitis. To compare direct impression of the glans on the agar surface of solid culture media with the collection of genital exudates with cotton swab for the diagnosis of candida balanitis. A prospective cross-sectional study was carried out during a 36-month period. Sexually transmitted disease clinic attendees with balanitis and asymptomatic men were included. Specimens for yeast culture were collected from the glans penis and inner preputial layer using the direct impression on CHROMagar candida medium and by swabbing with a sterile cotton swab. Among 478 men enrolled, 189 had balanitis. The prevalence of candida balanitis was 17.8% (85/478) confirmed after culture by direct impression; the swab method detected only 54/85 (63.5%) of these men. Of the 289 asymptomatic men, 36 (12.5%) yielded Candida spp; the swab method detected only 38.9% of these men. The risk of having candida balanitis is 8.9 (IC 95% 2.48 to 32.04) whenever the number of candida colonies recovered by direct impression was greater than 10. Direct impression on CHROMagar candida medium resulted in the highest Candida spp recovery rate. More than 10 colonies yielded by impression culture were statistically associated with candida balanitis. This method shows the ideal profile for sampling the male genital area for yeasts and should be included in the management of balanitis.

  12. Effects of 60 Cobalt ionizing radiation in morphology and metabolism of yeasts and Chlamydospore of Candida albicans

    International Nuclear Information System (INIS)

    Grillo, Michel R.F.; Demicheli, Marina C.; Andrade Junior, Heitor F.; Galiesteo Junior, Andres A.J.

    2015-01-01

    Candida albicans is a fungus responsible for 80-90% of fungal infections, as the symptoms are similar to those of systemic bacterial infections there is a difficulty for immediate diagnosis. These difficulties can lead to delays of antifungal therapy, which contributes to the high mortality rates associated with this infection. Resistance structures referred to as chlamydospores are very common in the pathogen, representing different cell types that form in response to certain genetic or environmental conditions. Recently, various antifungal agents and new therapeutic strategies have come into use, allowing the fungus to acquire a resistance to the drugs. The use of ionizing radiation has been widely employed for the production of immunogens against various parasites. In this work, we evaluate the effects of gamma radiation ( 60 Co) in yeast and chlamydospore of C. albicans with doses ranging from 320 to 10.240 Gy with Cobalt 60. Subsequently the samples were plated and after seven days, the colony forming units (CFU) told. The viability of irradiated cells were evaluated using the Janus green dye. A dose of 6000 Gy was considered ideal for the mitigation of chlamydospore and yeast. The dimorphic change mechanisms of both fungal structures were not harmed. The viability of chlamydospores remained above 70% while the yeast viability remained above 85%. By transmission electron microscopy and fluorescence microscopy may be noted cytoplasmic changes, defects in the cell wall, mitochondria, and the presence of partially preserved vesicles of both morphological forms of C. albicans. Irradiation both chlamydospore as C. albicans yeast allows the suppression of their reproduction, opening the possibility of their use in future candidate immunogens. (author)

  13. Effects of 60 Cobalt ionizing radiation in morphology and metabolism of yeasts and Chlamydospore of Candida albicans

    Energy Technology Data Exchange (ETDEWEB)

    Grillo, Michel R.F.; Demicheli, Marina C.; Andrade Junior, Heitor F.; Galiesteo Junior, Andres A.J., E-mail: galisteo@usp.br [Universidade de Sao Paulo (IMTSP/USP), Sao Paulo, SP (Brazil). Instituto de Medicina Tropical. Lab. de Protozoologia; Takakura, Cleusa F.H. [Universidade de Sao Paulo (FM/USP), Sao Paulo, SP (Brazil). Departamento de Patologia de Molestias Transmissiveis. Lab. de Patologia; Negro, Gilda M.B. del [Universidade de Sao Paulo (HCFM/USP/IMTSP/LIM-53), Sao Paulo, SP (Brazil). Hospital das Clinicas. Lab. de Micologia; Nascimento, Nanci do [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Candida albicans is a fungus responsible for 80-90% of fungal infections, as the symptoms are similar to those of systemic bacterial infections there is a difficulty for immediate diagnosis. These difficulties can lead to delays of antifungal therapy, which contributes to the high mortality rates associated with this infection. Resistance structures referred to as chlamydospores are very common in the pathogen, representing different cell types that form in response to certain genetic or environmental conditions. Recently, various antifungal agents and new therapeutic strategies have come into use, allowing the fungus to acquire a resistance to the drugs. The use of ionizing radiation has been widely employed for the production of immunogens against various parasites. In this work, we evaluate the effects of gamma radiation ({sup 60}Co) in yeast and chlamydospore of C. albicans with doses ranging from 320 to 10.240 Gy with Cobalt 60. Subsequently the samples were plated and after seven days, the colony forming units (CFU) told. The viability of irradiated cells were evaluated using the Janus green dye. A dose of 6000 Gy was considered ideal for the mitigation of chlamydospore and yeast. The dimorphic change mechanisms of both fungal structures were not harmed. The viability of chlamydospores remained above 70% while the yeast viability remained above 85%. By transmission electron microscopy and fluorescence microscopy may be noted cytoplasmic changes, defects in the cell wall, mitochondria, and the presence of partially preserved vesicles of both morphological forms of C. albicans. Irradiation both chlamydospore as C. albicans yeast allows the suppression of their reproduction, opening the possibility of their use in future candidate immunogens. (author)

  14. [The in vitro antifungal activities of fluconazole against pathogenic yeasts recently isolated from clinical specimens].

    Science.gov (United States)

    Yamaguchi, H; Igari, J; Kume, H; Abe, M; Oguri, T; Kanno, H; Kawakami, S; Okuzumi, K; Fukayama, M; Ito, A; Kawata, K; Uchida, K

    1997-09-01

    The emergence of Candida albicans resistance to azole antifungal agents have been reported in the U. S. and Europe. We examined the in vitro antifungal activities of fluconazole against clinical isolates collected by seven investigators in three years to examine if a tendency existed toward the development of azole-resistance among fungal isolates in Japan. The following results were obtained: 1. Sensitivities to fluconazole (FLCZ) were determined for yeast-like fungi, including 113 strains isolated in 1993, 149 strains isolated in 1994 and 205 strains isolated in 1995. No significant differences in sensitivities in the three years were detected. 2. Minimum inhibitory concentrations of FLCZ were 0.1-0.78 microgram/ml for C. albicans and 3.13-25 micrograms/ml for C. glabrata. Strains with 25 micrograms/ml of FLCZ's MIC were detected; two strains of C. krusei and one strain each of C. krusei, Trichospron beigelii and Hansenula anomala. No strains with higher than 50 micrograms/ml MIC of FLCZ were detected. 3. In vitro activities of FLCZ were compared between clinical strains isolated between 1993 and 1995 and clinical strains isolated before the marketing of FLCZ (up to December 1987) or clinical yeasts isolated between 1991 and 1992. No significant differences were observed, suggesting that no tendency existed toward azole resistance among fungal strains examined.

  15. Isolation and Identification of the Indigenous Yeast Population during Spontaneous Fermentation of Isabella (Vitis labrusca L.) Grape Must

    Science.gov (United States)

    Raymond Eder, María L.; Reynoso, Cristina; Lauret, Santiago C.; Rosa, Alberto L.

    2017-01-01

    Grape must harbors a complex community of yeast species responsible for spontaneous alcoholic fermentation. Although there are detailed studies on the microbiota of Vitis vinifera L. grapes, less is known about the diversity and behavior of yeast communities present on fermenting grape must from other species of Vitis. In this work, we used a culture-dependent method to study the identity and dynamics of the indigenous yeast population present during the spontaneous fermentation of Isabella (Vitis labrusca L.) grape must. Alcoholic fermentation was conducted using standard enological practices, and the associated non-Saccharomyces and S. cerevisiae yeast community was analyzed using selective growth media and 5.8-ITS DNA sequencing. Candida californica, Candida hellenica, Starmerella bacillaris (synonym Candida zemplinina), Hanseniaspora uvarum, and Hanseniaspora vineae were the main non-Saccharomyces species identified on Isabella fermenting must. Issatchenkia hanoiensis, a yeast species rarely found on Vitis vinifera L. grapes, was also recognized on Isabella grape must. Candida azymoides, Candida californica and Pichia cecembensis, identified in this work on Isabella fermenting must, have not previously been found on Vitis vinifera L. grape must. Interestingly, C. azymoides, I. hanoiensis and P. cecembensis have recently been isolated from the surface of Vitis labrusca L. grapes from vineyards in the Azores archipelago, suggesting that specific Vitis-yeast species associations are formed independently of geographic origin. We suggest that C. azymoides, C. californica, and P. cecembensis are yeast species preferentially associated with Vitis labrusca L. grapes. Specific biological interactions between grapevines and yeast species may underlie the assembly of differential Vitis-microbial communities. PMID:28424672

  16. Biomass production by Antarctic yeast strains: an investigation on the lipid composition

    International Nuclear Information System (INIS)

    Zlatanov, M.; Antova, G.; Angelova-Romova, M.; Pavlova, K.; Georgieva, K.; Rousenova-Videva, S.

    2010-01-01

    Psychrophilic yeast strains Rhodotorula glutinis AL_1_0_7, Sporobolomyces roseus AL_1_0_8, Cryptococcus albidus AL_5_5, Cryptococcus laurentii AL_5_6 and Cryptococcus laurentii AL_5_8 isolated from soil sample taken from the region of the Bulgarien base on Livingston Island, Antarctica, were studied. The biomass production was followed after cultivation of the yeasts in a medium with pH 5.3 at 15°C for 120 h. The biomass concentration by psychrophilic yeast strains was: R. glutinis AL_1_0_7-6.05 g/l, S. roseus AL108-5.78 g/l, Cr. albidus AL_5_5, Cr. laurentii AL_5_6 and Cr. laurentii AL_5_8-6.52 g/l, 6.84 g/l and 6.24 g/l, respectively. The extracted and separated lipids from the samples were supplied to analysis and the compositions of fatty acids, phospholipids, sterols as well as tocopherols were determined. Unsaturated fatty acids, mainly oleic (58.6-63.5%) and of saturated palmitic (18.2-24.5%), predominated in triacylglycerols. Sterols (0.1-0.3%) were valued in the dry yeast biomass. The content of phospholipids, mainly phosphatidylcholine, phosphatidylinositole and phosphatidylethanolamine was found to be in the range of 0.2-1.6%. The quantity of tocopherols was 0-26.3 mg/kg. All of tocopherol classes were established.

  17. Mechanism of iron uptake by the pathogenic yeast, Candida albicans

    International Nuclear Information System (INIS)

    Ismail, A.

    1986-01-01

    C. albicans requires iron for growth and phenotypic development. When deprived of iron, mycelium and bud formation was suppressed. Survival of the organism was also reduced under iron-limiting conditions. The combination of elevated temperature and iron-deprivation further reduced phenotypic development and survival of the yeast. The combination of elevated temperature and iron starvation resulted in a decrease in both the growth rate and siderophore production. However, with time, the cells were able to show partial recovery in the growth rate which occurred concomitantly with an increase in siderophore production. In order for siderophores to be utilized, ferri-siderophore receptors must be produced. The receptor was shown to be located in the plasma membrane of the yeast. Scatchard analysis of the binding of ferri-siderophores to plasma membrane receptors showed an increase in receptor affinity and number of binding sites in iron-starved cells when compared to control cells. Autoradiograms of the 58 Fe-siderophore-protein complex following SDS-PAGE separation of candidal proteins revealed the presence of a ferri-siderophore receptor of approximately 10,000 daltons. C. albicans strains which lacked the ability to synthesize phenolate siderophore maintained a phenolate receptor and bound candidal phenolate siderophore better than non-candidal phenolate siderophores

  18. Comparative Study of the New Colorimetric VITEK 2 Yeast Identification Card versus the Older Fluorometric Card and of CHROMagar Candida as a Source Medium with the New Card

    OpenAIRE

    Aubertine, C. L.; Rivera, M.; Rohan, S. M.; Larone, D. H.

    2006-01-01

    The new VITEK 2 colorimetric card was compared to the previous fluorometric card for identification of yeast. API 20C was considered the “gold standard.” The new card consistently performed better than the older card. Isolates from CHROMagar Candida plates were identified equally as well as those from Sabouraud dextrose agar.

  19. Parameters affecting methanol utilization by yeasts

    Energy Technology Data Exchange (ETDEWEB)

    Foda, M.S.; El-Masry, H.G.

    1981-01-01

    Screening of 28 yeast cultures, representing 22 species of various yeasts, with respect to their capabilities to assimilate methanol, has shown that this property was mostly found in certain species of the two genera Hansenula and Candida. When methanol was used as a sole carbon source for a methanol-adapted strain of Hansenula polymorpha, a linear yield response could be obtained with increasing alcohol up to 2% concentration. The amount of inoculum proved to be the decisive factor in determining a priori the ability of the organism to grow at 6% methanol as final concentration. The optimum pH values for growth ranged between 4.5-5.5 with no growth at pH 6.5 or higher. A marked growth stimulation was obtained when the medium was supplied with phosphate up to 0.08 M as final concentration. Within the nitrogen sources tested, corn steep liquor concentrate gave the highest yield of cells. The significance of the obtained results are discussed with reference to feasibilities of application.

  20. Improved bioethanol production using fusants of Saccharomyces cerevisiae and xylose-fermenting yeasts.

    Science.gov (United States)

    Kumari, Rajni; Pramanik, K

    2012-06-01

    The present research deals with the development of a hybrid yeast strain with the aim of converting pentose and hexose sugar components of lignocellulosic substrate to bioethanol by fermentation. Different fusant strains were obtained by fusing protoplasts of Saccharomyces cerevisiae and xylose-fermenting yeasts such as Pachysolen tannophilus, Candida shehatae and Pichia stipitis. The fusants were sorted by fluorescent-activated cell sorter and further confirmed by molecular characterization. The fusants were evaluated by fermentation of glucose-xylose mixture and the highest ethanol producing fusant was used for further study to ferment hydrolysates produced by acid pretreatment and enzymatic hydrolysis of cotton gin waste. Among the various fusant and parental strains used under present study, RPR39 was found to be stable and most efficient strain giving maximum ethanol concentration (76.8 ± 0.31 g L(-1)), ethanol productivity (1.06 g L(-1) h(-1)) and ethanol yield (0.458 g g(-1)) by fermentation of glucose-xylose mixture under test conditions. The fusant has also shown encouraging result in fermenting hydrolysates of cotton gin waste with ethanol concentration of 7.08 ± 0.142 g L(-1), ethanol yield of 0.44 g g(-1), productivity of 0.45 g L(-1) h(-1) and biomass yield of 0.40 g g(-1).

  1. Yeast transformation mediated by Agrobacterium strains harboring an Ri plasmid: comparative study between GALLS of an Ri plasmid and virE of a Ti plasmid.

    Science.gov (United States)

    Kiyokawa, Kazuya; Yamamoto, Shinji; Sato, Yukari; Momota, Naoto; Tanaka, Katsuyuki; Moriguchi, Kazuki; Suzuki, Katsunori

    2012-07-01

    Agrobacterium strains containing a Ti plasmid can transfer T-DNA not only to plants but also to fungi, including the yeast Saccharomyces cerevisiae. However, no Agrobacterium strain harboring an Ri plasmid has been evaluated in fungal transformation. Some Ri plasmids have GALLS , instead of virE1 and virE2. GALLS protein can functionally substitute in plant transformation for a structurally different protein VirE2. In this study, we compared the yeast transformation ability among Agrobacterium donors: a strain containing a Ti plasmid, strains harboring either an agropine-type or a mikimopine-type Ri plasmid, and a strain having a modified Ri plasmid supplemented with a Ti plasmid type virE operon. Agrobacterium strains possessing GALLS transformed yeast cells far less efficiently than the strain containing virE operon. Production of GALLS in recipient yeast cells improved the yeast transformation mediated by an Agrobacterium strain lacking neither GALLS nor virE operon. A reporter assay to detect mobilization of the proteins fused with Cre recombinase revealed that VirE2 protein is much more abundant in yeast cells than GALLS. Based on these results, we concluded that the low yeast transformability mediated by Agrobacterium strains having the Ri plasmid is because of low amount of mobilized GALLS in yeast cells. © 2012 The Authors Journal compilation © 2012 by the Molecular Biology Society of Japan/Blackwell Publishing Ltd.

  2. Structural investigations of yeast mannans

    International Nuclear Information System (INIS)

    Rademacher, K.H.

    1983-01-01

    Cell wall mannans were isolated from 8 different Candida species and separated in oligosaccharides by partial acetolysis. After gel chromatography specific acetolysis patterns were obtained. The 13 C NMR spectra of mannans and oligosaccharides were recorded. Signals at delta = 93.1 - 105.4 were assigned to certain chemical structures. Both the spectral patterns and the acetolysis patterns of the yeast mannans can be used for the discrimination of related yeasts. (author)

  3. Yeast Autolysis in Sparkling Wine Aging: Use of Killer and Sensitive Saccharomyces cerevisiae Strains in Co-Culture.

    Science.gov (United States)

    Lombardi, Silvia Jane; De Leonardis, Antonella; Lustrato, Giuseppe; Testa, Bruno; Iorizzo, Massimo

    2015-01-01

    Sparkling wines produced by traditional method owe their characteristics to secondary fermentation and maturation that occur during a slow ageing in bottles. Yeast autolysis plays an important role during the sparkling wine aging. Using a combination of killer and sensitive yeasts is possible to accelerate yeast autolysis and reduce maturing time. killer and sensitive Saccharomyces cerevisiae strains, separately and in co-cultures, were inoculated in base wine and bottled on pilot-plant scale. Commercial Saccaromyces bayanus strain was also investigated. Protein free amino acid and polysaccharides contents and sensory analysis were determined on the wine samples at 3, 6 and 9 months of aging. Yeast autolysis that occurs during the production of sparkling wines, obtained with co-cultures of killer and sensitive strains, has influenced free amino acids, total protein and polysaccharides content after 3 months aging time: sparkling wines, produced without the use of these yeasts, have reached the same results only after 9 months aging time. These results demonstrate that killer and sensitive yeasts in co-culture can accelerate the onset of autolysis in enological conditions, and has a positive effect on the quality of the aroma and flavor of sparkling wine. This paper offers an interesting biotechnological method to reduce production time of sparkling wine with economical benefits for the producers. We revised all patents relating to sparkling wine considering only those of interest for our study.

  4. [Invasive yeast infections in neutropenic patients].

    Science.gov (United States)

    Ruiz Camps, Isabel; Jarque, Isidro

    2016-01-01

    Invasive fungal diseases caused by yeasts still play an important role in the morbidity and mortality in neutropenic patients with haematological malignancies. Although the overall incidence of invasive candidiasis has decreased due to widespread use of antifungal prophylaxis, the incidence of non-Candida albicans Candida species is increasing compared with that of C.albicans, and mortality of invasive candidiasis continues to be high. In addition, there has been an increase in invasive infections caused by an array of uncommon yeasts, including species of the genus Malassezia, Rhodotorula, Trichosporon and Saprochaete, characterised by their resistance to echinocandins and poor prognosis. Copyright © 2016 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

  5. Thermotolerant Yeast Strains Adapted by Laboratory Evolution Show Trade-Off at Ancestral Temperatures and Preadaptation to Other Stresses.

    Science.gov (United States)

    Caspeta, Luis; Nielsen, Jens

    2015-07-21

    A major challenge for the production of ethanol from biomass-derived feedstocks is to develop yeasts that can sustain growth under the variety of inhibitory conditions present in the production process, e.g., high osmolality, high ethanol titers, and/or elevated temperatures (≥ 40 °C). Using adaptive laboratory evolution, we previously isolated seven Saccharomyces cerevisiae strains with improved growth at 40 °C. Here, we show that genetic adaptations to high temperature caused a growth trade-off at ancestral temperatures, reduced cellular functions, and improved tolerance of other stresses. Thermotolerant yeast strains showed horizontal displacement of their thermal reaction norms to higher temperatures. Hence, their optimal and maximum growth temperatures increased by about 3 °C, whereas they showed a growth trade-off at temperatures below 34 °C. Computational analysis of the physical properties of proteins showed that the lethal temperature for yeast is around 49 °C, as a large fraction of the yeast proteins denature above this temperature. Our analysis also indicated that the number of functions involved in controlling the growth rate decreased in the thermotolerant strains compared with the number in the ancestral strain. The latter is an advantageous attribute for acquiring thermotolerance and correlates with the reduction of yeast functions associated with loss of respiration capacity. This trait caused glycerol overproduction that was associated with the growth trade-off at ancestral temperatures. In combination with altered sterol composition of cellular membranes, glycerol overproduction was also associated with yeast osmotolerance and improved tolerance of high concentrations of glucose and ethanol. Our study shows that thermal adaptation of yeast is suitable for improving yeast resistance to inhibitory conditions found in industrial ethanol production processes. Yeast thermotolerance can significantly reduce the production costs of biomass

  6. Occurrence and growth of yeasts in processed meat products - implications for potential spoilage

    DEFF Research Database (Denmark)

    Nielsen, Dennis Sandris; Jacobsen, Tomas; Jespersen, Lene

    2008-01-01

    of the processed meat products. The yeast microflora was complex with 4-12 different species isolated from the different production sites. In general, Candida zeylanoides, Debaryomyces hansenii and the newly described Candida alimentaria were found to be the dominant yeast species. In addition, three putatively......Spoilage of meat products is in general attributed to bacteria but new processing and storage techniques inhibiting growth of bacteria may provide opportunities for yeasts to dominate the microflora and cause spoilage of the product. With the aim of obtaining a deeper understanding of the potential...... role of yeast in spoilage of five different processed meat products (bacon, ham, salami and two different liver patés), yeasts were isolated, enumerated and identified during processing, in the final product and in the final product at the end of shelf life. Yeasts were isolated along the bacon...

  7. Hypertonic sabouraud dextrose agar as a substrate for differentiation of Candida dubliniensis.

    Science.gov (United States)

    Akgül, Oncü; Cerikçioğlu, Nilgün

    2009-06-01

    In this study, we aimed to detect the proportion of Candida dubliniensis among yeast strains previously identified as C. albicans by using several phenotypic methods and PCR.For this purpose, we screened 300 strains by using phenotypic tests suggested for the identification of C. dubliniensis in the literature, but we detected high proportion of false-positive reactions. Only two strains (0.6%) were detected as true C. dubliniensis by PCR and API ID 32C methods. Moreover, these two strains gave the expected results with all the phenotypic tests, including modified salt tolerance test for C. dubliniensis.In conclusion, none of the phenotypic methods, except for the modified salt tolerance test, revealed 100% successful results in discrimination of C. albicans and C. dubliniensis species. However, in the tobacco agar test, the rate of false positivity was as low as 0.6%. We suggest that in the case of absence of PCR and other automatized identification systems, these two phenotypic tests can be used in routine laboratories to obtain a presumptive result.

  8. Antifungal activities of diphenyl diselenide and ebselen against echinocandin-susceptible and -resistant strains of Candida parapsilosis.

    Science.gov (United States)

    Chassot, Francieli; Pozzebon Venturini, Tarcieli; Baldissera Piasentin, Fernanda; Morais Santurio, Janio; Estivalet Svidzinski, Terezinha Inez; Hartz Alves, Sydney

    2016-10-01

    We evaluated the in vitro antifungal activity of diphenyl diselenide and ebselen against echinocandin-susceptible and -resistant strains of Candida parapsilosis using the broth microdilution method. Diphenyl diselenide (MIC range =1-8 µg/mL) and ebselen (MIC range =0.25-4 µg/mL) showed in vitro activity against echinocandin-susceptible isolates. However, ebselen also showed the highest antifungal activity against echinocandin-resistant strains (MIC range =0.06-4 µg/mL). This study demonstrated that the antifungal potential of diphenyl diselenide and ebselen deserves further investigation using in vivo experimental protocols.

  9. Unexpected effects of azole transporter inhibitors on antifungal susceptibility in Candida glabrata and other pathogenic Candida species.

    Science.gov (United States)

    Nagayoshi, Yohsuke; Miyazaki, Taiga; Shimamura, Shintaro; Nakayama, Hironobu; Minematsu, Asuka; Yamauchi, Shunsuke; Takazono, Takahiro; Nakamura, Shigeki; Yanagihara, Katsunori; Kohno, Shigeru; Mukae, Hiroshi; Izumikawa, Koichi

    2017-01-01

    The pathogenic fungus Candida glabrata is often resistant to azole antifungal agents. Drug efflux through azole transporters, such as Cdr1 and Cdr2, is a key mechanism of azole resistance and these genes are under the control of the transcription factor Pdr1. Recently, the monoamine oxidase A (MAO-A) inhibitor clorgyline was shown to inhibit the azole efflux pumps, leading to increased azole susceptibility in C. glabrata. In the present study, we have evaluated the effects of clorgyline on susceptibility of C. glabrata to not only azoles, but also to micafungin and amphotericin B, using wild-type and several mutant strains. The addition of clorgyline to the culture media increased fluconazole susceptibility of a C. glabrata wild-type strain, whereas micafungin and amphotericin B susceptibilities were markedly decreased. These phenomena were also observed in other medically important Candida species, including Candida albicans, Candida parapsilosis, Candida tropicalis, and Candida krusei. Expression levels of CDR1, CDR2 and PDR1 mRNAs and an amount of Cdr1 protein in the C. glabrata wild-type strain were highly increased in response to the treatment with clorgyline. However, loss of Cdr1, Cdr2, Pdr1, and a putative clorgyline target (Fms1), which is an ortholog of human MAO-A, or overexpression of CDR1 did not affect the decreased susceptibility to micafungin and amphotericin B in the presence of clorgyline. The presence of other azole efflux pump inhibitors including milbemycin A4 oxime and carbonyl cyanide 3-chlorophenylhydrazone also decreased micafungin susceptibility in C. glabrata wild-type, Δcdr1, Δcdr2, and Δpdr1 strains. These findings suggest that azole efflux pump inhibitors increase azole susceptibility but concurrently induce decreased susceptibility to other classes of antifungals independent of azole transporter functions.

  10. Presence and distribution of yeasts in the reproductive tract in healthy female horses.

    Science.gov (United States)

    Azarvandi, A; Khosravi, A R; Shokri, H; Talebkhan Garoussi, M; Gharahgouzlou, F; Vahedi, G; Sharifzadeh, A

    2017-09-01

    Yeasts are commensal organisms found in the reproductive and gastrointestinal tracts, and on the skin and other mucosa in mammals. The purpose of this study was to isolate and identify yeast flora in the caudal reproductive tract in healthy female horses. Longitudinal study. A total of 453 samples were collected using double-guarded swabs from the vestibule, clitoral fossa and vagina in 151 horses. All samples were cultured on Sabouraud 4% dextrose agar and incubated at 35°C for 7-10 days. Isolates were identified according to their morphological characteristics and biochemical profiles. Yeast colonies were isolated from 60 (39.7%) of the 151 horses. The isolated yeasts belonged to nine genera, and included Candida spp. (53.2%), Cryptococcus spp. (12.2%), Saccharomyces spp. (10.5%), Geotrichum spp. (8.0%), Rhodotorula spp. (7.1%), Malassezia spp. (3.7%), Trichosporon spp. (2.6%), Kluyveromyces spp. (2.6%) and Sporothrix spp. (0.2%). Candida krusei (43.1%) was the most frequent Candida species isolated. There was a significant difference in prevalence between C. krusei and other Candida species (Pyeast isolates (48.0%) than the vagina (18.3%). The isolation of yeast colonies from multiparous females (76.8%) was significantly higher than from maiden mares (P<0.05). The study was limited by the difficulty of distinguishing between normal flora and potential pathogens. Candida spp., in particular C. krusei, represent important flora resident in the caudal reproductive tract in healthy female horses. This is particularly important in contexts that require the initiation of empirical treatment prior to the completion of culture results. © 2016 EVJ Ltd.

  11. Yeasts in pigeon feacal droppings in Lisbon - Portugal, 1994

    Directory of Open Access Journals (Sweden)

    Herminia Maria Lourdes Martins

    1997-10-01

    Full Text Available In this work, the results of a preliminary survey held in city of Lisbon. Eighty faecal samples were examined between Summer and Autumn, 1994, from twelve different urban areas, mainly near churchs and monuments where birds nest, rest or eat. From each sample 1 g was weighted and suspensed in 10 ml of destilled sterilized water and consecutive decimal diluitions were executed. Yeasts were enumerated and grouped by species, based on morphological types. On eighty faecal samples the most prevalent yeasts identified were: Candida humicola (51.5%, Candida albicans (48.7%, Cryptococcus neoformans (5% and Trichosporon cutaneum (37.5%.

  12. The combined rapid detection and species-level identification of yeasts in simulated blood culture using a colorimetric sensor array.

    Science.gov (United States)

    Shrestha, Nabin K; Lim, Sung H; Wilson, Deborah A; SalasVargas, Ana Victoria; Churi, Yair S; Rhodes, Paul A; Mazzone, Peter J; Procop, Gary W

    2017-01-01

    A colorimetric sensor array (CSA) has been demonstrated to rapidly detect and identify bacteria growing in blood cultures by obtaining a species-specific "fingerprint" of the volatile organic compounds (VOCs) produced during growth. This capability has been demonstrated in prokaryotes, but has not been reported for eukaryotic cells growing in culture. The purpose of this study was to explore if a disposable CSA could differentially identify 7 species of pathogenic yeasts growing in blood culture. Culture trials of whole blood inoculated with a panel of clinically important pathogenic yeasts at four different microorganism loads were performed. Cultures were done in both standard BacT/Alert and CSA-embedded bottles, after adding 10 mL of spiked blood to each bottle. Color changes in the CSA were captured as images by an optical scanner at defined time intervals. The captured images were analyzed to identify the yeast species. Time to detection by the CSA was compared to that in the BacT/Alert system. One hundred sixty-two yeast culture trials were performed, including strains of several species of Candida (Ca. albicans, Ca. glabrata, Ca. parapsilosis, and Ca. tropicalis), Clavispora (synonym Candida) lusitaniae, Pichia kudriavzevii (synonym Candida krusei) and Cryptococcus neoformans, at loads of 8.2 × 105, 8.3 × 103, 8.5 × 101, and 1.7 CFU/mL. In addition, 8 negative trials (no yeast) were conducted. All negative trials were correctly identified as negative, and all positive trials were detected. Colorimetric responses were species-specific and did not vary by inoculum load over the 500000-fold range of loads tested, allowing for accurate species-level identification. The mean sensitivity for species-level identification by CSA was 74% at detection, and increased with time, reaching almost 95% at 4 hours after detection. At an inoculum load of 1.7 CFU/mL, mean time to detection with the CSA was 6.8 hours (17%) less than with the BacT/Alert platform. The CSA

  13. L-arabinose fermenting yeast

    Science.gov (United States)

    Zhang, Min; Singh, Arjun; Suominen, Pirkko; Knoshaug, Eric; Franden, Mary Ann; Jarvis, Eric

    2013-02-12

    An L-arabinose utilizing yeast strain is provided for the production of ethanol by introducing and expressing bacterial araA, araB and araD genes. L-arabinose transporters are also introduced into the yeast to enhance the uptake of arabinose. The yeast carries additional genomic mutations enabling it to consume L-arabinose, even as the only carbon source, and to produce ethanol. A yeast strain engineered to metabolize arabinose through a novel pathway is also disclosed. Methods of producing ethanol include utilizing these modified yeast strains.

  14. Raspberry wine fermentation with suspended and immobilized yeast cells of two strains of Saccharomyces cerevisiae.

    Science.gov (United States)

    Djordjević, Radovan; Gibson, Brian; Sandell, Mari; de Billerbeck, Gustavo M; Bugarski, Branko; Leskošek-Čukalović, Ida; Vunduk, Jovana; Nikićević, Ninoslav; Nedović, Viktor

    2015-01-01

    The objectives of this study were to assess the differences in fermentative behaviour of two different strains of Saccharomyces cerevisiae (EC1118 and RC212) and to determine the differences in composition and sensory properties of raspberry wines fermented with immobilized and suspended yeast cells of both strains at 15 °C. Analyses of aroma compounds, glycerol, acetic acid and ethanol, as well as the kinetics of fermentation and a sensory evaluation of the wines, were performed. All fermentations with immobilized yeast cells had a shorter lag phase and faster utilization of sugars and ethanol production than those fermented with suspended cells. Slower fermentation kinetics were observed in all the samples that were fermented with strain RC212 (suspended and immobilized) than in samples fermented with strain EC1118. Significantly higher amounts of acetic acid were detected in all samples fermented with strain RC212 than in those fermented with strain EC1118 (0.282 and 0.602 g/l, respectively). Slightly higher amounts of glycerol were observed in samples fermented with strain EC1118 than in those fermented with strain RC212. Copyright © 2014 John Wiley & Sons, Ltd.

  15. Antifungal Susceptibilities of Candida Species Causing Vulvovaginitis and Epidemiology of Recurrent Cases

    Science.gov (United States)

    Richter, Sandra S.; Galask, Rudolph P.; Messer, Shawn A.; Hollis, Richard J.; Diekema, Daniel J.; Pfaller, Michael A.

    2005-01-01

    There are limited data regarding the antifungal susceptibility of yeast causing vulvovaginal candidiasis, since cultures are rarely performed. Susceptibility testing was performed on vaginal yeast isolates collected from January 1998 to March 2001 from 429 patients with suspected vulvovaginal candidiasis. The charts of 84 patients with multiple positive cultures were reviewed. The 593 yeast isolates were Candida albicans (n = 420), Candida glabrata (n = 112), Candida parapsilosis (n = 30), Candida krusei (n = 12), Saccharomyces cerevisiae ( n = 9), Candida tropicalis (n = 8), Candida lusitaniae (n = 1), and Trichosporon sp. (n = 1). Multiple species suggesting mixed infection were isolated from 27 cultures. Resistance to fluconazole and flucytosine was observed infrequently (3.7% and 3.0%); 16.2% of isolates were resistant to itraconazole (MIC ≥ 1 μg/ml). The four imidazoles (econazole, clotrimazole, miconazole, and ketoconazole) were active: 94.3 to 98.5% were susceptible at ≤1 μg/ml. Among different species, elevated fluconazole MICs (≥16 μg/ml) were only observed in C. glabrata (15.2% resistant [R], 51.8% susceptible-dose dependent [S-DD]), C. parapsilosis (3.3% S-DD), S. cerevisiae (11.1% S-DD), and C. krusei (50% S-DD, 41.7% R, considered intrinsically fluconazole resistant). Resistance to itraconazole was observed among C. glabrata (74.1%), C. krusei (58.3%), S. cerevisiae (55.6%), and C. parapsilosis (3.4%). Among 84 patients with recurrent episodes, non-albicans species were more common (42% versus 20%). A ≥4-fold rise in fluconazole MIC was observed in only one patient with C. parapsilosis. These results support the use of azoles for empirical therapy of uncomplicated candidal vulvovaginitis. Recurrent episodes are more often caused by non-albicans species, for which azole agents are less likely to be effective. PMID:15872235

  16. Donor Derived Candida stellimalicola in a Clinical Specimen: Preservation Fluid Contamination During Pancreas Procurement.

    Science.gov (United States)

    Dupont, Damien; Huguenin, Antoine; Tisserand, Elodie; Reiter, Véronique; Morelon, Emmanuel; Badet, Lionel; Villena, Isabelle; Wallon, Martine; Toubas, Dominique

    2017-07-05

    We report here a case of possible donor-derived Candida stellimalicola infection after pancreas transplantation. Candida stellimalicola, an environmental non-filamentous yeast, was isolated from both the peritoneal fluid of the graft donor and the preservation fluid of the transplanted pancreas. Interestingly, this strain exhibited high minimum inhibitory concentrations to azoles. These results justified the use of echinocandins as therapy instead of fluconazole. This switch permitted a favorable outcome. To our knowledge, this is the first report of C. stellimalicola from clinical samples and therefore the first reported case of a possible human infection. This case report highlights the need for standardized microbiological procedures in solid organ transplant settings. Moreover, it underlines the importance of using molecular identification technique when routine techniques do not allow successful identification of the pathogen. It is of utmost importance to determine sensitivity profile, even in the absence of species-level identification, because resistance to fluconazole is not uncommon, especially in emergent species.

  17. Hsp90 governs echinocandin resistance in the pathogenic yeast Candida albicans via calcineurin.

    Directory of Open Access Journals (Sweden)

    Sheena D Singh

    2009-07-01

    Full Text Available Candida albicans is the leading fungal pathogen of humans, causing life-threatening disease in immunocompromised individuals. Treatment of candidiasis is hampered by the limited number of antifungal drugs whose efficacy is compromised by host toxicity, fungistatic activity, and the emergence of drug resistance. We previously established that the molecular chaperone Hsp90, which regulates the form and function of diverse client proteins, potentiates resistance to the azoles in C. albicans and in the model yeast Saccharomyces cerevisiae. Genetic studies in S. cerevisiae revealed that Hsp90's role in azole resistance is to enable crucial cellular responses to the membrane stress exerted by azoles via the client protein calcineurin. Here, we demonstrate that Hsp90 governs cellular circuitry required for resistance to the only new class of antifungals to reach the clinic in decades, the echinocandins, which inhibit biosynthesis of a critical component of the fungal cell wall. Pharmacological or genetic impairment of Hsp90 function reduced tolerance of C. albicans laboratory strains and resistance of clinical isolates to the echinocandins and created a fungicidal combination. Compromising calcineurin function phenocopied compromising Hsp90 function. We established that calcineurin is an Hsp90 client protein in C. albicans: reciprocal co-immunoprecipitation validated physical interaction; Hsp90 inhibition blocked calcineurin activation; and calcineurin levels were depleted upon genetic reduction of Hsp90. The downstream effector of calcineurin, Crz1, played a partial role in mediating calcineurin-dependent stress responses activated by echinocandins. Hsp90's role in echinocandin resistance has therapeutic potential given that genetic compromise of C. albicans HSP90 expression enhanced the efficacy of an echinocandin in a murine model of disseminated candidiasis. Our results identify the first Hsp90 client protein in C. albicans, establish an entirely

  18. Spontaneous and UV-induced variations in the activity of biomass synthesis in Candida utilis haploid and diploid strains

    International Nuclear Information System (INIS)

    Kondrat'eva, T.F.; Lin'kova, M.A.; Lobacheva, N.A.

    1988-01-01

    Candida utilis diploid strains have greater variations induced by UV irradiation in the activity of biomass synthesis as compared with the parent haploid culture. Clones with an activity of the synthesis greater that the mean population one appear more frequently in the diploid strains. Mathematical analysis has confirmed the significance of the results and the hypothesis according to which the frequency of variants more active in biomass synthesis rises after the action of UV

  19. Brewing characteristics of piezosensitive sake yeasts

    Science.gov (United States)

    Nomura, Kazuki; Hoshino, Hirofumi; Igoshi, Kazuaki; Onozuka, Haruka; Tanaka, Erika; Hayashi, Mayumi; Yamazaki, Harutake; Takaku, Hiroaki; Iguchi, Akinori; Shigematsu, Toru

    2018-04-01

    Application of high hydrostatic pressure (HHP) treatment to food processing is expected as a non-thermal fermentation regulation technology that supresses over fermentation. However, the yeast Saccharomyces cerevisiae used for Japanese rice wine (sake) brewing shows high tolerance to HHP. Therefore, we aimed to generate pressure-sensitive (piezosensitive) sake yeast strains by mating sake with piezosensitive yeast strains to establish an HHP fermentation regulation technology and extend the shelf life of fermented foods. The results of phenotypic analyses showed that the generated yeast strains were piezosensitive and exhibited similar fermentation ability compared with the original sake yeast strain. In addition, primary properties of sake brewed using these strains, such as ethanol concentration, sake meter value and sake flavor compounds, were almost equivalent to those obtained using the sake yeast strain. These results suggest that the piezosensitive strains exhibit brewing characteristics essentially equivalent to those of the sake yeast strain.

  20. Effect of fermentation conditions on lipase production by Candida utilis

    Directory of Open Access Journals (Sweden)

    SANJA Z. GRBAVCIC

    2007-08-01

    Full Text Available A wild yeast strain isolated from spoiled soybean oil and identified as Candida utilis initially presented rather low lipase activity (approximately 4 IU dm-3 in submerged culture in a universal yeast medium containing 2 % malt extract. Stu­dies were undertaken to improve the lipase production. The best yields of lipase were obtained with a medium supplemented with caprylic and oleic acids as indu­cers, but higher concentrations of the former (> 0.5 % had a negative effect on the lipase production and cell growth. The type of nitrogen source seemed also to be very important. The highest lipolytic activity of 284 IU dm-3 was achieved after 5 days of fermentation in a medium containing oleic acid and hydrolyzed casein as carbon and nitrogen sources, respectively, and supplemented with Tween 80®. It was shown that optimization of the fermentation conditions can lead to a significant improvement in the lipase production (more than 70-fold higher compared to the initial value obtained in the non-optimized medium.

  1. SCREENING OF SELECTED OLEAGINOUS YEASTS FOR LIPID PRODUCTION FROM GLYCEROL AND SOME FACTORS WHICH AFFECT LIPID PRODUCTION BY YARROWIA LIPOLYTICA STRAINS

    Directory of Open Access Journals (Sweden)

    Salinee Sriwongchai

    2013-04-01

    Full Text Available The ability of eight yeast strains to utilize glycerol as a sole carbon source and accumulate lipids in a chemically defined medium was screened. Among the yeasts, Yarrowia lipolytica strains DSM 70561 and JDC 335 grew to high cell densities on glycerol. These strains were further tested for lipid accumulation under varying nutritional conditions in Erlenmeyer flasks. The results showed that strains DSM 70561 and JDC 335 accumulated lipids up to 37.1 % and 54.4 % of total cell dry weight, respectively, when the defined medium was supplemented with 1 g/L urea and 2 g/L yeast extract. The lipids accumulated by the two yeasts contained a high proportion of C16:0, C18:1, C18:2 and C18:0 fatty acids. The results suggest that Y. lipolytica strains DSM 70561 and JDC 335 have the potential for converting crude glycerol into fatty acids which can in turn be utilized as substrate for biodiesel production.

  2. Microbial Detoxification of Bifenthrin by a Novel Yeast and Its Potential for Contaminated Soils Treatment

    OpenAIRE

    Chen, Shaohua; Luo, Jianjun; Hu, Meiying; Geng, Peng; Zhang, Yanbo

    2012-01-01

    Bifenthrin is one the most widespread pollutants and has caused potential effect on aquatic life and human health, yet little is known about microbial degradation in contaminated regions. A novel yeast strain ZS-02, isolated from activated sludge and identified as Candida pelliculosa based on morphology, API test and 18S rDNA gene analysis, was found highly effective in degrading bifenthrin over a wide range of temperatures (20-40 °C) and pH (5-9). On the basis of response surface methodology...

  3. The use of lactic acid-producing, malic acid-producing, or malic acid-degrading yeast strains for acidity adjustment in the wine industry.

    Science.gov (United States)

    Su, Jing; Wang, Tao; Wang, Yun; Li, Ying-Ying; Li, Hua

    2014-03-01

    In an era of economic globalization, the competition among wine businesses is likely to get tougher. Biotechnological innovation permeates the entire world and intensifies the severity of the competition of the wine industry. Moreover, modern consumers preferred individualized, tailored, and healthy and top quality wine products. Consequently, these two facts induce large gaps between wine production and wine consumption. Market-orientated yeast strains are presently being selected or developed for enhancing the core competitiveness of wine enterprises. Reasonable biological acidity is critical to warrant a high-quality wine. Many wild-type acidity adjustment yeast strains have been selected all over the world. Moreover, mutation breeding, metabolic engineering, genetic engineering, and protoplast fusion methods are used to construct new acidity adjustment yeast strains to meet the demands of the market. In this paper, strategies and concepts for strain selection or improvement methods were discussed, and many examples based upon selected studies involving acidity adjustment yeast strains were reviewed. Furthermore, the development of acidity adjustment yeast strains with minimized resource inputs, improved fermentation, and enological capabilities for an environmentally friendly production of healthy, top quality wine is presented.

  4. Xylitol production by yeasts isolated from rotting wood in the Galápagos Islands, Ecuador, and description of Cyberlindnera galapagoensis f.a., sp. nov.

    Science.gov (United States)

    Guamán-Burneo, Maria C; Dussán, Kelly J; Cadete, Raquel M; Cheab, Monaliza A M; Portero, Patricia; Carvajal-Barriga, Enrique J; da Silva, Sílvio S; Rosa, Carlos A

    2015-10-01

    This study evaluated D-xylose-assimilating yeasts that are associated with rotting wood from the Galápagos Archipelago, Ecuador, for xylitol production from hemicellulose hydrolysates. A total of 140 yeast strains were isolated. Yeasts related to the clades Yamadazyma, Kazachstania, Kurtzmaniella, Lodderomyces, Metschnikowia and Saturnispora were predominant. In culture assays using sugarcane bagasse hemicellulose hydrolysate, Candida tropicalis CLQCA-24SC-125 showed the highest xylitol production, yield and productivity (27.1 g L(-1) xylitol, Y p/s (xyl) = 0.67 g g(-1), Qp = 0.38 g L(-1). A new species of Cyberlindnera, strain CLQCA-24SC-025, was responsible for the second highest xylitol production (24 g L(-1), Y p/s (xyl) = 0.64 g g(-1), Qp = 0.33 g L(-1) h(-1)) on sugarcane hydrolysate. The new xylitol-producing species Cyberlindnera galapagoensis f.a., sp. nov., is proposed to accommodate the strain CLQCA-24SC-025(T) (=UFMG-CM-Y517(T); CBS 13997(T)). The MycoBank number is MB 812171.

  5. In vitro and in vivo activity of a novel antifungal small molecule against Candida infections.

    Directory of Open Access Journals (Sweden)

    Sarah Sze Wah Wong

    Full Text Available Candida is the most common fungal pathogen of humans worldwide and has become a major clinical problem because of the growing number of immunocompromised patients, who are susceptible to infection. Moreover, the number of available antifungals is limited, and antifungal-resistant Candida strains are emerging. New and effective antifungals are therefore urgently needed. Here, we discovered a small molecule with activity against Candida spp. both in vitro and in vivo. We screened a library of 50,240 small molecules for inhibitors of yeast-to-hypha transition, a major virulence attribute of Candida albicans. This screening identified 20 active compounds. Further examination of the in vitro antifungal and anti-biofilm properties of these compounds, using a range of Candida spp., led to the discovery of SM21, a highly potent antifungal molecule (minimum inhibitory concentration (MIC 0.2-1.6 µg/ml. In vitro, SM21 was toxic to fungi but not to various human cell lines or bacterial species and was active against Candida isolates that are resistant to existing antifungal agents. Moreover, SM21 was relatively more effective against biofilms of Candida spp. than the current antifungal agents. In vivo, SM21 prevented the death of mice in a systemic candidiasis model and was also more effective than the common antifungal nystatin at reducing the extent of tongue lesions in a mouse model of oral candidiasis. Propidium iodide uptake assay showed that SM21 affected the integrity of the cell membrane. Taken together, our results indicate that SM21 has the potential to be developed as a novel antifungal agent for clinical use.

  6. Thermotolerant Yeast Strains Adapted by Laboratory Evolution Show Trade-Off at Ancestral Temperatures and Preadaptation to Other Stresses

    DEFF Research Database (Denmark)

    Caspeta, Luis; Nielsen, Jens

    2015-01-01

    adaptive laboratory evolution, we previously isolated seven Saccharomyces cerevisiae strains with improved growth at 40°C. Here, we show that genetic adaptations to high temperature caused a growth trade-off at ancestral temperatures, reduced cellular functions, and improved tolerance of other stresses...... in the ancestral strain. The latter is an advantageous attribute for acquiring thermotolerance and correlates with the reduction of yeast functions associated with loss of respiration capacity. This trait caused glycerol overproduction that was associated with the growth trade-off at ancestral temperatures....... In combination with altered sterol composition of cellular membranes, glycerol overproduction was also associated with yeast osmotolerance and improved tolerance of high concentrations of glucose and ethanol. Our study shows that thermal adaptation of yeast is suitable for improving yeast resistance...

  7. Isolation and molecular identification of yeast strains from “Rabilé” a ...

    African Journals Online (AJOL)

    Isolation and molecular identification of yeast strains from “Rabilé” a starter of local fermented drink. Ibrahim Keita, Marius K Somda, Aly Savadogo, Iliassou Mogmenga, Ousmane Koita, Alfred S Traore ...

  8. In vitro synergism of simvastatin and fluconazole against Candida species

    Directory of Open Access Journals (Sweden)

    Everardo Albuquerque Menezes

    2012-08-01

    Full Text Available Systemic fungal infections are responsible for high mortality rates. Several species of fungi may be involved, but Candida spp. is the most prevalent. Simvastatin is used to lower cholesterol and also exhibits antifungal action. The aim of this study was to evaluate the synergistic action of simvastatin with fluconazole against strains of Candida spp. Susceptibility testing was performed according to protocol M27-A3, by broth microdilution method and the synergistic effect of simvastatin and fluconazole was calculated based on FICI (Fractional Inhibitory Concentration Index. Eleven strains were evaluated, and simvastatin showed a synergistic effect with fluconazole against 10 (91% of the Candida spp. strains tested. Simvastatin may be a valuable drug in the treatment of systemic infections caused by Candida spp.

  9. Prevalence of Candida albicans, Candida dubliniensis and Candida africana in pregnant women suffering from vulvovaginal candidiasis in Argentina.

    Science.gov (United States)

    Mucci, María Josefina; Cuestas, María Luján; Landanburu, María Fernanda; Mujica, María Teresa

    Vulvovaginal candidiasis (VVC) is a vulvovaginitis commonly diagnosed in gynecology care. In recent years, the taxonomy of the most important pathogenic Candida species, such as Candida albicans have undergone significant changes. This study examined the prevalence of C. albicans, Candida africana, and Candida dubliniensis in vaginal specimens from 210 pregnant women suffering from vulvovaginitis or having asymptomatic colonization. Phenotypic and molecular methods were used for the identification of the species. During the studied period, 55 isolates of Candida or other yeasts were obtained from specimens collected from 52 patients suffering from vulvovaginitis (24.8%). C. albicans was the predominant Candida species in 42 isolates (80.7%), either alone or in combination with other species of the genus (5.7%, n=3). Additionally, nine isolates of C. albicans (50%) were obtained from asymptomatic patients (n=18). C. dubliniensis was the causative agent in 2 (3.8%) cases of VVC, and was also isolated in one asymptomatic patient. Molecular assays were carried out using specific PCR to amplify the ACT1-associated intron sequence of C. dubliniensis. The amplification of the HWP1 gene also correctly identified isolates of the species C. albicans and C. dubliniensis. No C. africana was isolated in this work. Some C. albicans isolates were either homozygous or heterozygous at the HWP1 locus. The distribution of heterozygous and homozygous C. albicans isolates at the HWP1 locus was very similar among patients suffering from VVC and asymptomatic patients (p=0.897). The presence of C. albicans and C. dubliniensis, and the absence of C. africana in pregnant is noteworthy. Copyright © 2016 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

  10. Exoenzyme activity and possibility identification of Candida dubliniensis among Candida albicans species isolated from vaginal candidiasis.

    Science.gov (United States)

    Jafari, Maryam; Salari, Samira; Pakshir, Keyvan; Zomorodian, Kamiar

    2017-09-01

    Vulvovaginal candidiasis (VVC) or vaginal candidiasis is a common fungal infection of the genitals causing inflammation, irritation, itching, and vaginal discharge. Common yeast infections are caused by the yeast species C. albicans. However, there are other species of Candida such as C. dubliniensis which are considered as the causative agents of this infection. Hydrolytic enzymes such as proteinase and coagulase are known as virulence factors. The aim of this study was the molecular confirmation and differentiation of C. dubliniensis among C. albicans strains isolated from women with vulvovaginal candidiasis by PCR-Restriction Fragment Length Polymorphism (PCR-RFLP) and the evaluation of proteinase and coagulase activities. A total of 100 C. albicans strains isolated from women with vulvovaginal candidiasis referred to Shiraz medical clinics were enrolled in the study. All the isolates were primarily identified by conventional methods. PCR-RFLP method was used for the confirmation and identification of C. albicans and C. dubliniensis. Moreover, in vitro proteinase and coagulase activities of these isolates were evaluated using bovine serum albumin media and classical rabbit plasma tube test. As a result, PCR-RFLP identified 100% of the isolates as C. albicans, and no C. dubliniensis could be identified in this study. 84% of the isolates showed proteinase activity, whereas coagulase activity was only detected in 5% of the isolates. This study reveals that C. dubliniensis plays no role in vaginal candidiasis in Iranian patients. Proteinase production could be an essential virulence factor in C. albicans pathogenicity, but coagulase activity has less potential in this matter. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Isolation of a yeast strain able to produce a polygalacturonase with maceration activity of cassava roots

    Directory of Open Access Journals (Sweden)

    María Alicia Martos

    2013-06-01

    Full Text Available The objective of the present study was the isolation of a yeast strain, from citrus fruit peels, able to produce a polygalacturonase by submerged fermentation with maceration activity of raw cassava roots. Among 160 yeast strains isolated from citrus peels, one strain exhibited the strongest pectinolytic activity. This yeast was identified as Wickerhamomyces anomalus by 5.8S-ITS RFLP analysis and confirmed by amplification of the nucleotide sequence. The yeast produced a polygalacturonase (PG in Erlenmeyer shake flasks containing YNB, glucose, and citrus pectin. PG synthesis occurred during exponential growth phase, reaching 51 UE.mL-1 after 8 hours of fermentation. A growth yield (Yx/s of 0.43 gram of cell dry weight per gram of glucose consumed was obtained, and a maximal specific growth rate (µm of 0.346 h-1 was calculated. The microorganism was unable to assimilate sucrose, galacturonic acid, polygalacturonic acid, or citrus pectin, but it required glucose as carbon and energy source and polygalacturonic acid or citrus pectin as inducers of enzyme synthesis. The crude enzymatic extract of Wickerhamomyces anomalus showed macerating activity of raw cassava. This property is very important in the production of dehydrated mashed cassava, a product of regional interest in the province of Misiones, Argentina.

  12. Sequence and Analysis of the Genome of the Pathogenic Yeast Candida orthopsilosis

    Science.gov (United States)

    Riccombeni, Alessandro; Vidanes, Genevieve; Proux-Wéra, Estelle; Wolfe, Kenneth H.; Butler, Geraldine

    2012-01-01

    Candida orthopsilosis is closely related to the fungal pathogen Candida parapsilosis. However, whereas C. parapsilosis is a major cause of disease in immunosuppressed individuals and in premature neonates, C. orthopsilosis is more rarely associated with infection. We sequenced the C. orthopsilosis genome to facilitate the identification of genes associated with virulence. Here, we report the de novo assembly and annotation of the genome of a Type 2 isolate of C. orthopsilosis. The sequence was obtained by combining data from next generation sequencing (454 Life Sciences and Illumina) with paired-end Sanger reads from a fosmid library. The final assembly contains 12.6 Mb on 8 chromosomes. The genome was annotated using an automated pipeline based on comparative analysis of genomes of Candida species, together with manual identification of introns. We identified 5700 protein-coding genes in C. orthopsilosis, of which 5570 have an ortholog in C. parapsilosis. The time of divergence between C. orthopsilosis and C. parapsilosis is estimated to be twice as great as that between Candida albicans and Candida dubliniensis. There has been an expansion of the Hyr/Iff family of cell wall genes and the JEN family of monocarboxylic transporters in C. parapsilosis relative to C. orthopsilosis. We identified one gene from a Maltose/Galactoside O-acetyltransferase family that originated by horizontal gene transfer from a bacterium to the common ancestor of C. orthopsilosis and C. parapsilosis. We report that TFB3, a component of the general transcription factor TFIIH, undergoes alternative splicing by intron retention in multiple Candida species. We also show that an intein in the vacuolar ATPase gene VMA1 is present in C. orthopsilosis but not C. parapsilosis, and has a patchy distribution in Candida species. Our results suggest that the difference in virulence between C. parapsilosis and C. orthopsilosis may be associated with expansion of gene families. PMID:22563396

  13. Genotyping of the MTL loci and susceptibility to two antifungal agents of Candida glabrata clinical isolates

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    María Teresa Lavaniegos-Sobrino

    2009-08-01

    Full Text Available The opportunistic fungal pathogen Candida glabrata is the second most common isolate from bloodstream infections worldwide and is naturally less susceptible to the antifungal drug fluconazole than other Candida species. C. glabrata is a haploid yeast that contains three mating-type like loci (MTL, although no sexual cycle has been described. Strains containing both types of mating information at the MTL1 locus are found in clinical isolates, but it is thought that strains containing type a information are more common. Here we investigated if a particular combination of mating type information at each MTLlocus is more prevalent in clinical isolates from hospitalized patients in Mexico and if there is a correlation between mating information and resistance to fluconazole and 5-fluorocytosine. We found that while both types of information at MTL1 are equally represented in a collection of 64 clinical isolates, the vast majority of isolates contain a-type information at MTL2 and α-type at MTL3. We also found no correlation of the particular combination of mating type information at the three MTL loci and resistance to fluconazole.

  14. Development of Yeast Populations during Processing and Ripening of Blue Veined Cheese

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    Alison M. Knox

    2003-01-01

    Full Text Available Varieties of blue veined cheese were analyzed regularly during different stages of manufacturing and ripening to determine the origin of contaminating the yeasts present in them, their population diversity and development until the end of the storage. Yeast diversity and development in the inner and outer core of the cheeses during ripening were also compared. Air samples revealed few if any yeasts whereas the samples in contact with the equipment and the surroundings revealed high number of yeasts, implicating it as the possible main source of post-pasteurization contamination, as very few yeasts were isolated from the milk and cheese making process itself. Samples from the inner and outer core of the maturing cheeses had typical survival curves. The number of yeasts on the outer core was about a 100-fold more than of those in the inner core. The most abundant yeasts isolated from the environment and ripening cheeses were identified as Debaryomyces hansenii, Saccharomyces cerevisiae, Torulaspora delbrueckii, Trichosporon beigelii, Candida versatilis and Cryptococcus albidus, while the yeasts Candida zeylanoides and Dekkera anomala were additionally isolated from the environment. Yeasts were present in high number, making their occurrence in blue-veined cheeses meaningful.

  15. Investigation of Association between Slime Production by Candida ...

    African Journals Online (AJOL)

    Purpose: To determine the susceptibilities of fluconazole and voriconazole based on slime production by Candida spp. Methods: Candida strains (115) isolated in the period between January 2011 and January 2012 were included in this study. ... Yıldırım Beyazıt Training Hospital, were included in this study. Candida ...

  16. Effects of feedstock and co-culture of Lactobacillus fermentum and wild Saccharomyces cerevisiae strain during fuel ethanol fermentation by the industrial yeast strain PE-2.

    Science.gov (United States)

    Reis, Vanda R; Bassi, Ana Paula G; Cerri, Bianca C; Almeida, Amanda R; Carvalho, Isis G B; Bastos, Reinaldo G; Ceccato-Antonini, Sandra R

    2018-02-16

    Even though contamination by bacteria and wild yeasts are frequently observed during fuel ethanol fermentation, our knowledge regarding the effects of both contaminants together is very limited, especially considering that the must composition can vary from exclusively sugarcane juice to a mixture of molasses and juice, affecting the microbial development. Here we studied the effects of the feedstock (sugarcane juice and molasses) and the co-culture of Lactobacillus fermentum and a wild Saccharomyces cerevisiae strain (rough colony and pseudohyphae) in single and multiple-batch fermentation trials with an industrial strain of S. cerevisiae (PE-2) as starter yeast. The results indicate that in multiple-cycle batch system, the feedstock had a minor impact on the fermentation than in single-cycle batch system, however the rough yeast contamination was more harmful than the bacterial contamination in multiple-cycle batch fermentation. The inoculation of both contaminants did not potentiate the detrimental effect in any substrate. The residual sugar concentration in the fermented broth had a higher concentration of fructose than glucose for all fermentations, but in the presence of the rough yeast, the discrepancy between fructose and glucose concentrations were markedly higher, especially in molasses. The biggest problem associated with incomplete fermentation seemed to be the lower consumption rate of sugar and the reduced fructose preference of the rough yeast rather than the lower invertase activity. Lower ethanol production, acetate production and higher residual sugar concentration are characteristics strongly associated with the rough yeast strain and they were not potentiated with the inoculation of L. fermentum.

  17. Produção de protoplastos e lise da parede celular de leveduras utilizando β-1,3 glucanase Protoplasts production and yeast cell wall lysis using β-1,3 glucanase

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    Luciana Francisco Fleuri

    2010-06-01

    Full Text Available O presente trabalho visou a aplicação da β-1,3 glucanase lítica, obtida do microrganismo Cellulosimicrobium cellulans 191, na produção de protoplastos e na lise da parede celular de leveduras. A preparação bruta da enzima foi capaz de lisar as leveduras Kluyveromyces lodderi, Saccharomyces cerevisiae (Fleischmann e Itaiquara, S. cerevisiae KL-88, S. diastaticus NCYC 713, S. cerevisiae NCYC 1001, Candida glabrata NCYC 388, Kluyveromyces marxianus NCYC 587 e Hansenula mrakii NCYC 500. A β-1,3 glucanase purificada foi capaz de lisar as leveduras Saccharomyces cerevisiae KL-88, Saccharomyces capensis, Debaromyces vanriji, Pachysolen tannophillus, Kluyveromyces drosophilarum, Candida glabrata, Hansenula mrakii e Pichia membranaefaciens e formar protoplastos de Saccharomyces cerevisiae KL-88.The aim of this work was the application of lytic β-1,3 glucanase obtained from Cellulosimicrobium cellulans strain 191 in the production of protoplasts and lysis of yeast cell walls. The crude extract demonstrated lysis activity against the yeasts Kluyveromyces lodderi, Saccharomyces cerevisiae (Fleischmann and Itaiquara, S. cerevisiae KL-88, S. diastaticus NCYC 713, S. cerevisiae NCYC 1001, Candida glabrata NCYC 388, Kluyveromyces marxianus NCYC 587, and Hansenula mrakii NCYC 500. The purified β-1,3 glucanase demonstrated lysis activity against the yeasts Saccharomyces cerevisiae KL-88, Saccharomyces capensis, Debaromyces vanriji, Pachysolen tannophillus, Kluyveromyces drosophilarum, Candida glabrata, Hansenula mrakii, and Pichia membranaefaciens, and it was able to produce Saccharomyces cerevisiae KL-88 protoplasts.

  18. Biofilm antifungal susceptibility of Candida urine isolated from ambulatory patients

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    Débora da Luz Becker

    2016-07-01

    Full Text Available Background and Objectives: the association between the biofilm formations an antifungal resistance has been suggested to be an important factor in the pathogenesis of several Candida species. Besides, studies have included invasive candidiasis from hospitalized patients; however there are few studies that evaluated the species distribution, antifungal susceptibility and biofilm formation of Candida species isolated from ambulatory patients. Thus, the aim of this study was to evaluate whether biofilm producing contributes to antifungal resistance in Candida isolates from urine sample obtained from ambulatory patients. Methods: During one year, 25 urine samples positive for yeast were collected, stored and plated on agar supplemented with chloramphenicol and Sabouread left at room temperature for 5 days for subsequent: 52% (13/25 were C. albicans, 36% (9/25 C. tropicalis, 8% (2/25 C. krusei and 4% (1/25 C. parapsilosis. Results: The ability to form biofilm was detected in 23 (92% of the yeast studied and 15.4% (2/13 of C. albicans were fluconazole (FLU and ketoconazole (KET resistant, while 11.1% (1/9 of C. tropicalis were ketoconazole resistant and were anidulafungin (ANI non-susceptible. Conclusion: our results showed the high capacity for biofilm formation among Candida isolates from ambulatory patients.

  19. Development of DNA probes for Candida albicans

    International Nuclear Information System (INIS)

    Cheung, L.L.; Hudson, J.B.

    1988-01-01

    An attempt was made to produce DNA probes that could be used as a rapid and efficient means of detecting candidiasis (invasive Candida infection) in immunocompromised patients. Whole DNA from Candida albicans was digested with restriction endonuclease, and the resulting fragments were randomly cloned into a plasmid vector. Several recombinant plasmids were evaluated for cross-hybridization to various other Candida species, other fungal DNAs, and to nonfungal DNAs. Cross reactions were observed between the probes and different yeasts, but none with unrelated DNAs. Some recombinants were genus-specific, and two of these were applied to the analysis of C. albicans growth curves. It became evident that, although both 32 P- and biotin-labelled probes could be made quite sensitive, a possible limitation in their diagnostic potential was the poor liberation of Candida DNA from cells. Thus, better methods of treatment of clinical specimens will be required before such probes will be useful in routine diagnosis

  20. Development of DNA probes for Candida albicans

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, L.L.; Hudson, J.B.

    1988-07-01

    An attempt was made to produce DNA probes that could be used as a rapid and efficient means of detecting candidiasis (invasive Candida infection) in immunocompromised patients. Whole DNA from Candida albicans was digested with restriction endonuclease, and the resulting fragments were randomly cloned into a plasmid vector. Several recombinant plasmids were evaluated for cross-hybridization to various other Candida species, other fungal DNAs, and to nonfungal DNAs. Cross reactions were observed between the probes and different yeasts, but none with unrelated DNAs. Some recombinants were genus-specific, and two of these were applied to the analysis of C. albicans growth curves. It became evident that, although both /sup 32/P- and biotin-labelled probes could be made quite sensitive, a possible limitation in their diagnostic potential was the poor liberation of Candida DNA from cells. Thus, better methods of treatment of clinical specimens will be required before such probes will be useful in routine diagnosis.

  1. Vulvovaginal Candida: a study of (a)symptomatic women

    NARCIS (Netherlands)

    Engberts, M.K.

    2007-01-01

    The research described in this thesis concerns presence of asymptomatic vaginal Candida and vulvovaginal candidiasis. Vulvovaginal candidiasis (VVC) is an infection caused by abnormal growth of yeasts in the mucosa of the female genital tract. Acute vulvar pruritus and vaginal discharge are the

  2. Aspectos micológicos e suscetibilidade in vitro de leveduras do gênero Candida em pacientes HIV-positivos provenientes do Estado de Mato Grosso Mycological aspects and susceptibility in vitro the yeast of the genus Candida from HIV-positive patients in the State of Mato Grosso

    Directory of Open Access Journals (Sweden)

    Olivia Cometti Favalessa

    2010-12-01

    Full Text Available INTRODUÇÃO: A candidíase é uma das infecções fúngicas mais frequentes entre os pacientes infectados pelo vírus da imunodeficiência humana. O presente estudo objetivou a caracterização das leveduras do gênero Candida de distintas amostras clínicas, provenientes de pacientes HIV - positivos, assim como a determinação do perfil de suscetibilidade in vitro a cinco drogas antifúngicas. MÉTODOS: A caracterização dos isolados de Candida sp foi realizada através da metodologia clássica, testes bioquímicos (zimograma e auxanograma e morfológicos (prova do tubo germinativo e microcultivo em lâmina. Também, foram realizadas a técnica genotípica (PCR e identificação pelo método comercial API 20C AUX (BioMeriéux. Para a determinação do perfil de suscetibilidade in vitro, foram utilizadas cinco drogas antifúngicas (cetoconazol, fluconazol, itraconazol, voriconazol e anfotericina B, através do método comercialmente disponível - Etest. RESULTADOS: Foram identificados 105 isolados de leveduras do gênero Candida provenientes de 102 pacientes infectados pelo vírus HIV. Destes, foram caracterizadas 82 (78,1% Candida albicans, 8 (7,6% Candida parapsilosis, 8 (7,6% Candida tropicalis, 4 (3,8% Candida krusei, 2 (1,9% Candida glabrata e 1 (1% Candida guilliermondii. CONCLUSÕES: Considerando o perfil geral de sensibilidade, 60% dos isolados foram suscetíveis a todos os antifúngicos testados, porém as espécies C. tropicalis e C. krusei demonstraram uma tendência a valores mais elevados de CIMs para os azóis do que os encontrados paraC. albicans, sugerindo resistência.INTRODUCTION: Candidiasis is one of the most common fungal infections among patients infected by human immunodeficiency virus. The present study aimed to characterize yeasts of the genus Candida from distinct clinical samples from HIV-positive patients and determine the in vitro susceptibility profile to five antifungal drugs. METHODS: Characterization of

  3. Distinct Domestication Trajectories in Top-Fermenting Beer Yeasts and Wine Yeasts.

    Science.gov (United States)

    Gonçalves, Margarida; Pontes, Ana; Almeida, Pedro; Barbosa, Raquel; Serra, Marta; Libkind, Diego; Hutzler, Mathias; Gonçalves, Paula; Sampaio, José Paulo

    2016-10-24

    Beer is one of the oldest alcoholic beverages and is produced by the fermentation of sugars derived from starches present in cereal grains. Contrary to lager beers, made by bottom-fermenting strains of Saccharomyces pastorianus, a hybrid yeast, ale beers are closer to the ancient beer type and are fermented by S. cerevisiae, a top-fermenting yeast. Here, we use population genomics to investigate (1) the closest relatives of top-fermenting beer yeasts; (2) whether top-fermenting yeasts represent an independent domestication event separate from those already described; (3) whether single or multiple beer yeast domestication events can be inferred; and (4) whether top-fermenting yeasts represent non-recombinant or recombinant lineages. Our results revealed that top-fermenting beer yeasts are polyphyletic, with a main clade composed of at least three subgroups, dominantly represented by the German, British, and wheat beer strains. Other beer strains were phylogenetically close to sake, wine, or bread yeasts. We detected genetic signatures of beer yeast domestication by investigating genes previously linked to brewing and using genome-wide scans. We propose that the emergence of the main clade of beer yeasts is related with a domestication event distinct from the previously known cases of wine and sake yeast domestication. The nucleotide diversity of the main beer clade more than doubled that of wine yeasts, which might be a consequence of fundamental differences in the modes of beer and wine yeast domestication. The higher diversity of beer strains could be due to the more intense and different selection regimes associated to brewing. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Bioactivity of a Family of Chiral Nonracemic Aminobenzylnaphthols towards Candida albicans

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    Maria Annunziata M. Capozzi

    2014-04-01

    Full Text Available Chiral nonracemic aminobenzylnaphthols were obtained by a Betti multi-component reaction between 2-naphthol, aryl aldehydes and enantiopure arylethylamine. Moreover, some new aminobenzylnaphthols were synthesized by a similar reaction between 2-naphthol, aryl aldehydes and prolinol. These aminobenzylnaphthols, synthesized from different components and thus having different structural features, were tested as anti-yeast agents inhibiting Candida albicans. The effect towards the test strain was studied with a microdilution approach and three different concentrations (150, 300 and 450 µg/mL were tested. The best results were found for the aminobenzylnaphthols obtained from 1-naphthylethylamine and from natural prolinol. The use of the two-way ANOVA highlighted the better performances of the prolinol derivative among the differently structured aminobenzylnaphthols that were screened. The activity towards C. albicans of this prolinol derivative resulted to be interesting and could represent a promising alternative to overcome the problem of the strains resistant to the traditional antifungals.

  5. Yeast ecology of Kombucha fermentation.

    Science.gov (United States)

    Teoh, Ai Leng; Heard, Gillian; Cox, Julian

    2004-09-01

    Kombucha is a traditional fermentation of sweetened tea, involving a symbiosis of yeast species and acetic acid bacteria. Despite reports of different yeast species being associated with the fermentation, little is known of the quantitative ecology of yeasts in Kombucha. Using oxytetracycline-supplemented malt extract agar, yeasts were isolated from four commercially available Kombucha products and identified using conventional biochemical and physiological tests. During the fermentation of each of the four products, yeasts were enumerated from both the cellulosic pellicle and liquor of the Kombucha. The number and diversity of species varied between products, but included Brettanomyces bruxellensis, Candida stellata, Schizosaccharomyces pombe, Torulaspora delbrueckii and Zygosaccharomyces bailii. While these yeast species are known to occur in Kombucha, the enumeration of each species present throughout fermentation of each of the four Kombucha cultures demonstrated for the first time the dynamic nature of the yeast ecology. Kombucha fermentation is, in general, initiated by osmotolerant species, succeeded and ultimately dominated by acid-tolerant species.

  6. Simple low cost differentiation of Candida auris from Candida haemulonii complex using CHROMagar Candida medium supplemented with Pal's medium.

    Science.gov (United States)

    Kumar, Anil; Sachu, Arun; Mohan, Karthika; Vinod, Vivek; Dinesh, Kavitha; Karim, Shamsul

    Candida auris is unique due to its multidrug resistance and misidentification as Candida haemulonii by commercial systems. Its correct identification is important to avoid inappropriate treatments. To develop a cheap method for differentiating C. auris from isolates identified as C. haemulonii by VITEK2. Fifteen C. auris isolates, six isolates each of C. haemulonii and Candida duobushaemulonii, and one isolate of Candida haemulonii var. vulnera were tested using CHROMagar Candida medium supplemented with Pal's agar for better differentiation. On CHROMagar Candida medium supplemented with Pal's agar all C. auris strains showed confluent growth of white to cream colored smooth colonies at 37°C and 42°C after 24 and 48h incubation and did not produce pseudohyphae. The isolates of the C. haemulonii complex, on the contrary, showed poor growth of smooth, light-pink colonies at 24h while at 48h the growth was semiconfluent with the production of pseudohyphae. C. haemulonii complex failed to grow at 42°C. We report a rapid and cheap method using CHROMagar Candida medium supplemented with Pal's agar for differentiating C. auris from isolates identified as C. haemulonii by VITEK2. Copyright © 2017 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

  7. Metabolic engineering of a haploid strain derived from a triploid industrial yeast for producing cellulosic ethanol.

    Science.gov (United States)

    Kim, Soo Rin; Skerker, Jeffrey M; Kong, In Iok; Kim, Heejin; Maurer, Matthew J; Zhang, Guo-Chang; Peng, Dairong; Wei, Na; Arkin, Adam P; Jin, Yong-Su

    2017-03-01

    Many desired phenotypes for producing cellulosic biofuels are often observed in industrial Saccharomyces cerevisiae strains. However, many industrial yeast strains are polyploid and have low spore viability, making it difficult to use these strains for metabolic engineering applications. We selected the polyploid industrial strain S. cerevisiae ATCC 4124 exhibiting rapid glucose fermentation capability, high ethanol productivity, strong heat and inhibitor tolerance in order to construct an optimal yeast strain for producing cellulosic ethanol. Here, we focused on developing a general approach and high-throughput screening method to isolate stable haploid segregants derived from a polyploid parent, such as triploid ATCC 4124 with a poor spore viability. Specifically, we deleted the HO genes, performed random sporulation, and screened the resulting segregants based on growth rate, mating type, and ploidy. Only one stable haploid derivative (4124-S60) was isolated, while 14 other segregants with a stable mating type were aneuploid. The 4124-S60 strain inherited only a subset of desirable traits present in the parent strain, same as other aneuploids, suggesting that glucose fermentation and specific ethanol productivity are likely to be genetically complex traits and/or they might depend on ploidy. Nonetheless, the 4124-60 strain did inherit the ability to tolerate fermentation inhibitors. When additional genetic perturbations known to improve xylose fermentation were introduced into the 4124-60 strain, the resulting engineered strain (IIK1) was able to ferment a Miscanthus hydrolysate better than a previously engineered laboratory strain (SR8), built by making the same genetic changes. However, the IIK1 strain showed higher glycerol and xylitol yields than the SR8 strain. In order to decrease glycerol and xylitol production, an NADH-dependent acetate reduction pathway was introduced into the IIK1 strain. By consuming 2.4g/L of acetate, the resulting strain (IIK1A

  8. Cellular characterisation of Candida tropicalis presenting fluconazole-related trailing growth

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    Marcos Dornelas-Ribeiro

    2012-02-01

    Full Text Available We assessed fluconazole susceptibility in 52 Candida tropicalis clinical strains using seven antifungal susceptibility methods, including broth microdilution (BMD [standard M27 A3 (with neutral and acid pH, ATB Fungus 3, Vitek 2 system and flow cytometric analysis] and agar-based methods (disk diffusion and E-test. Trailing growth, detection of cell-associated secreted aspartic proteases (Saps and morphological and ultrastructural traits of these clinical strains were also examined. The ranges of fluconazole 24 h-minimum inhibitory concentration (MIC values were similar among all methods. The essential agreement among the methods used for MIC determinations was excellent and all methods categorised all strains as susceptible, except for one strain that showed a minor error. The presence of the trailing effect was assessed by six methods. Trailing positivity was observed for 86.5-100% of the strains. The exception was the BMD-Ac method where trailing growth was not observed. Morphological and ultrastructural alterations were detected in C. tropicalis trailing cells, including mitochondrial swelling and cell walls with irregular shapes. We tested the production of Saps in 13 C. tropicalis strains expressing trailing growth through flow cytometry. Our results showed that all of the C. tropicalis strains up-regulated surface Sap expression after 24 h or 48 h of exposure to fluconazole, which was not observed in untreated yeast strains. We concluded that C. tropicalis strains expressing trailing growth presented some particular features on both biological and ultrastructural levels.

  9. Microbial Stereoselective One-Step Conversion of Diols to Chiral Lactones in Yeast Cultures

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    Filip Boratyński

    2015-12-01

    Full Text Available It has been shown that whole cells of different strains of yeast catalyze stereoselective oxidation of meso diols to the corresponding chiral lactones. Among screening-scale experiments, Candida pelliculosa ZP22 was selected as the most effective biocatalyst for the oxidation of monocyclic diols 3a–b with respect to the ratio of high conversion to stereoselectivity. This strain was used in the preparative oxidation, affording enantiomerically-enriched isomers of lactones: (+-(3aR,7aS-cis-hexahydro-1(3H -isobenzofuranone (2a and (+-(3aS,4,7,7aR-cis-tetrahydro-1(3H-isobenzofuranone (2b. Scaling up the culture growth, as well as biotransformation conditions has been successfully accomplished. Among more bulky substrates, bicyclic diol 3d was totally converted into enantiomerically-pure exo-bridged (+-(3aR,4S,7R,7aS-cis-tetrahydro-4,7-methanoisobenzofuran -1(3H-one (2d by Yarrovia lipolytica AR71. Microbial oxidation of diol 3f by Candida sake AM908 and Rhodotorula rubra AM4 afforded optically-pure cis-3-butylhexahydro-1(3H -isobenzofuranone (2f, however with low conversion.

  10. Undecylenic Acid Inhibits Morphogenesis of Candida albicans

    OpenAIRE

    McLain, Nealoo; Ascanio, Rhoda; Baker, Carol; Strohaver, Robert A.; Dolan, Joseph W.

    2000-01-01

    Resilient liners are frequently used to treat denture stomatitis, a condition often associated with Candida albicans infections. Of 10 liners tested, 2 were found to inhibit the switch from the yeast form to hyphae and a third was found to stimulate this switch. The inhibitor was determined to be undecylenic acid.

  11. Undecylenic acid inhibits morphogenesis of Candida albicans.

    Science.gov (United States)

    McLain, N; Ascanio, R; Baker, C; Strohaver, R A; Dolan, J W

    2000-10-01

    Resilient liners are frequently used to treat denture stomatitis, a condition often associated with Candida albicans infections. Of 10 liners tested, 2 were found to inhibit the switch from the yeast form to hyphae and a third was found to stimulate this switch. The inhibitor was determined to be undecylenic acid.

  12. Epidemiology and phospholipase activity of oral Candida spp. among patients with central nervous system diseases before and after dental cleaning procedure

    Directory of Open Access Journals (Sweden)

    Aurélia Silva Ribeiro

    2010-03-01

    Full Text Available Patients suffering of diseases that affect central nervous system may be considered more susceptible to the infectious diseases of mouth. Sixty-nine patients suffering of cerebral palsy, Down's syndrome and metal retardation were submitted to saliva examination for the presence of Candida spp. before and after a procedure of dental cleaning. The isolates were submitted to assay for verifying phospholipase production. 55.10% of the patients provided isolation of Candida spp. The frequency of isolation obtained before dental procedure was: C. albicans (83.33%, C. krusei (8.33% and C. kefyr, C. parapsilosis and C. glabrata (2.78% each. The frequency after the procedure was: C. albicans (68.57%, C. parapsilosis (11.43%, C. krusei and C. kefyr (8.57% each and Candida glabrata (2.86%. We verified significantly difference (p < 0.01 between populations obtained at the two examinations. Phospholipase production was verified only among C. albicans strains and the proportion of producers was higher when testing isolates obtained after dental cleaning procedure. Studies focused on Candida spp. isolation are useful for better comprehension of the role of these yeasts on the oral flora from patients with cerebral palsy, Down's syndrome and metal retardation.

  13. Occurrence and significance of Candida albicans in Lake Ontario bathing beaches

    National Research Council Canada - National Science Library

    Sherry, J. P; Kuchma, S. R; Zarzour, J; Dutka, B. J

    1979-01-01

    .... In this report we have reviewed the potential of different fungi to serve as fecal pollution indicators and the literature pertaining to the occurrence of the potentially pathogenic yeast Candida...

  14. Oral Candida spp. colonization in human immunodeficiency virus-infected individuals

    Directory of Open Access Journals (Sweden)

    D. V. Moris

    2008-01-01

    Full Text Available Several yeast species of Candida genus can colonize the skin as well as the mucous membrane of the vagina and the digestive tract for short or long periods. Depending on the host's immunological state and the yeast's virulence, colonization can become an infection, invading the colonized tissues and also disseminating. AIDS is characterized by the host's intensive and progressive immunodepression which manifests as diverse symptoms, mainly lesions in the mouth. Oral candidiasis is the most prevalent opportunistic infection in individuals infected with human immunodeficiency virus (HIV and is an important indicator of the disease progress and the immunosuppression increase. The factors involved in the equilibrium between Candida spp. and HIV-infected subjects are sometimes contradictory and were evaluated in the present study specially for colonization.

  15. Yeast dynamics during spontaneous fermentation of mawe and tchoukoutou, two traditional products from Benin

    DEFF Research Database (Denmark)

    Greppi, Anna; Rantisou, Kalliopi; Padonou, Wilfrid

    2013-01-01

    Mawe and tchoukoutou are two traditional fermented foods largely consumed in Benin, West Africa. Their preparations remain as a house art and they are the result of spontaneous fermentation processes. In this study, dynamics of the yeast populations occurring during spontaneous fermentations...... of mawe and tchoukoutou were investigated using both culture-dependent and -independent approaches. For each product, two productions were followed. Samples were taken at different fermentation times and yeasts were isolated, resulting in the collection of 177 isolates. They were identified by the PCR......-DGGE technique followed by the sequencing of the D1/D2 domain of the 26S rRNA gene. The predominant yeast species identified were typed by rep-PCR. Candida krusei was the predominant yeast species in mawe fermentation followed by Candida glabrata and Kluyveromyces marxianus. Other yeast species were detected...

  16. [Susceptibility to azoles and amphotericin B of isolates of Candida spp. Experience of a university health network, between 2004 and 2010].

    Science.gov (United States)

    Porte, Lorena; León, Pilar; Gárate, Cynthia; Guzmán, Ana María; Labarca, Jaime; García, Patricia

    2012-04-01

    To describe antifungal susceptibility testing surveillance (December 2004-September 2010) in Candida spp., for amphotericin B, fluconazole and voriconazole, at the Laboratorio de Microbiología, Pontificia Universidad Católica de Chile. The study was performed utilizing E test and included yeasts from invasive origin and isolates in which antifungal susceptibility testing was asked for by the patient's physician. The yeasts were mainly recovered from urine samples (n: 64), blood cultures (n: 51) and secretions (n: 24). Two hundred ninety three isolates were studied: C. albicans (38%), C. glabrata (30%), C. tropicalis (11%), C. parapsilosis (10%), C. krusei (4%) and others (7%). All Candida species were 100% susceptible to amphotericin B, except C. krusei (1/12). Fluconazole's global susceptibility in C. albicans was 91.8%, but 100% in isolates from blood cultures versus 76% in isolates from urine. C. tropicalis was 93.9% susceptible to fluconazole, C. parapsilosis, 90% and C. glabrata 30.3%. C. krusei had no susceptible isolates to fluconazole. Voriconazole resistance was mainly present in C. glabrata (11.5%). We recommend the study of antifungal susceptibility in isolates from invasive origin, selected urine strains and C. glabrata. Fluconazole remains effective in C. albicans from blood.

  17. Candida Biofilms: Threats, Challenges, and Promising Strategies

    Directory of Open Access Journals (Sweden)

    Mafalda Cavalheiro

    2018-02-01

    Full Text Available Candida species are fungal pathogens known for their ability to cause superficial and systemic infections in the human host. These pathogens are able to persist inside the host due to the development of pathogenicity and multidrug resistance traits, often leading to the failure of therapeutic strategies. One specific feature of Candida species pathogenicity is their ability to form biofilms, which protects them from external factors such as host immune system defenses and antifungal drugs. This review focuses on the current threats and challenges when dealing with biofilms formed by Candida albicans, Candida glabrata, Candida tropicalis, and Candida parapsilosis, highlighting the differences between the four species. Biofilm characteristics depend on the ability of each species to produce extracellular polymeric substances (EPS and display dimorphic growth, but also on the biofilm substratum, carbon source availability and other factors. Additionally, the transcriptional control over processes like adhesion, biofilm formation, filamentation, and EPS production displays great complexity and diversity within pathogenic yeasts of the Candida genus. These differences not only have implications in the persistence of colonization and infections but also on antifungal resistance typically found in Candida biofilm cells, potentiated by EPS, that functions as a barrier to drug diffusion, and by the overexpression of drug resistance transporters. The ability to interact with different species in in vivo Candida biofilms is also a key factor to consider when dealing with this problem. Despite many challenges, the most promising strategies that are currently available or under development to limit biofilm formation or to eradicate mature biofilms are discussed.

  18. Candida Biofilms: Threats, Challenges, and Promising Strategies.

    Science.gov (United States)

    Cavalheiro, Mafalda; Teixeira, Miguel Cacho

    2018-01-01

    Candida species are fungal pathogens known for their ability to cause superficial and systemic infections in the human host. These pathogens are able to persist inside the host due to the development of pathogenicity and multidrug resistance traits, often leading to the failure of therapeutic strategies. One specific feature of Candida species pathogenicity is their ability to form biofilms, which protects them from external factors such as host immune system defenses and antifungal drugs. This review focuses on the current threats and challenges when dealing with biofilms formed by Candida albicans, Candida glabrata, Candida tropicalis , and Candida parapsilosis , highlighting the differences between the four species. Biofilm characteristics depend on the ability of each species to produce extracellular polymeric substances (EPS) and display dimorphic growth, but also on the biofilm substratum, carbon source availability and other factors. Additionally, the transcriptional control over processes like adhesion, biofilm formation, filamentation, and EPS production displays great complexity and diversity within pathogenic yeasts of the Candida genus. These differences not only have implications in the persistence of colonization and infections but also on antifungal resistance typically found in Candida biofilm cells, potentiated by EPS, that functions as a barrier to drug diffusion, and by the overexpression of drug resistance transporters. The ability to interact with different species in in vivo Candida biofilms is also a key factor to consider when dealing with this problem. Despite many challenges, the most promising strategies that are currently available or under development to limit biofilm formation or to eradicate mature biofilms are discussed.

  19. Candida Biofilms: Threats, Challenges, and Promising Strategies

    Science.gov (United States)

    Cavalheiro, Mafalda; Teixeira, Miguel Cacho

    2018-01-01

    Candida species are fungal pathogens known for their ability to cause superficial and systemic infections in the human host. These pathogens are able to persist inside the host due to the development of pathogenicity and multidrug resistance traits, often leading to the failure of therapeutic strategies. One specific feature of Candida species pathogenicity is their ability to form biofilms, which protects them from external factors such as host immune system defenses and antifungal drugs. This review focuses on the current threats and challenges when dealing with biofilms formed by Candida albicans, Candida glabrata, Candida tropicalis, and Candida parapsilosis, highlighting the differences between the four species. Biofilm characteristics depend on the ability of each species to produce extracellular polymeric substances (EPS) and display dimorphic growth, but also on the biofilm substratum, carbon source availability and other factors. Additionally, the transcriptional control over processes like adhesion, biofilm formation, filamentation, and EPS production displays great complexity and diversity within pathogenic yeasts of the Candida genus. These differences not only have implications in the persistence of colonization and infections but also on antifungal resistance typically found in Candida biofilm cells, potentiated by EPS, that functions as a barrier to drug diffusion, and by the overexpression of drug resistance transporters. The ability to interact with different species in in vivo Candida biofilms is also a key factor to consider when dealing with this problem. Despite many challenges, the most promising strategies that are currently available or under development to limit biofilm formation or to eradicate mature biofilms are discussed. PMID:29487851

  20. Particular Candida albicans strains in the digestive tract of dyspeptic patients, identified by multilocus sequence typing.

    Directory of Open Access Journals (Sweden)

    Yan-Bing Gong

    Full Text Available BACKGROUND: Candida albicans is a human commensal that is also responsible for chronic gastritis and peptic ulcerous disease. Little is known about the genetic profiles of the C. albicans strains in the digestive tract of dyspeptic patients. The aim of this study was to evaluate the prevalence, diversity, and genetic profiles among C. albicans isolates recovered from natural colonization of the digestive tract in the dyspeptic patients. METHODS AND FINDINGS: Oral swab samples (n = 111 and gastric mucosa samples (n = 102 were obtained from a group of patients who presented dyspeptic symptoms or ulcer complaints. Oral swab samples (n = 162 were also obtained from healthy volunteers. C. albicans isolates were characterized and analyzed by multilocus sequence typing. The prevalence of Candida spp. in the oral samples was not significantly different between the dyspeptic group and the healthy group (36.0%, 40/111 vs. 29.6%, 48/162; P > 0.05. However, there were significant differences between the groups in the distribution of species isolated and the genotypes of the C. albicans isolates. C. albicans was isolated from 97.8% of the Candida-positive subjects in the dyspeptic group, but from only 56.3% in the healthy group (P < 0.001. DST1593 was the dominant C. albicans genotype from the digestive tract of the dyspeptic group (60%, 27/45, but not the healthy group (14.8%, 4/27 (P < 0.001. CONCLUSIONS: Our data suggest a possible link between particular C. albicans strain genotypes and the host microenvironment. Positivity for particular C. albicans genotypes could signify susceptibility to dyspepsia.

  1. Effectiveness of the association of 2 probiotic strains formulated in a slow release vaginal product, in women affected by vulvovaginal candidiasis: a pilot study.

    Science.gov (United States)

    Vicariotto, Franco; Del Piano, Mario; Mogna, Luca; Mogna, Giovanni

    2012-10-01

    Vulvovaginal candidiasis (VVC) is the second most common cause of vaginitis after bacterial vaginosis, and it is diagnosed in up to 40% of women with vaginal complaints in the primary care setting. Among Candida spp., Candida albicans is the most common infectious agent. The treatment of choice for uncomplicated VVC is achieved with single-dose or short-course therapy in over 90% of cases. Several topical and oral drugs are available, without evidence for superiority of any agent or route of administration. In any case, most classic treatments are unable to significantly offer a protection against possible recurrences. In recent years, probiotics are emerging as a new strategy to counteract VVC. In fact, they are well known for their ability to lower intravaginal pH, thus establishing a barrier effect against many types of yeasts. Some strains are also able to exert additional and more focused antagonistic activities mediated by specific molecules such as hydrogen peroxide and bacteriocins. For example, Lactobacillus fermentum LF5 (CNCM I-789) was successfully tested in 4 human trials involving a total of 340 women reporting VVC at enrollment. In any case, the way used to deliver probiotics to the vaginal environment represents a crucial point. The aim of this work was to first select 1 or more probiotic strains in vitro with an antagonistic activity on Candida yeasts and then to perform an in vivo human pilot study using an association of the most promising and active bacteria. For this purpose, 2 probiotic strains Probiotical S.p.A (Italy) were selected based on their strong in vitro inhibition activity toward 4 particular Candida species, namely C. albicans, Candida glabrata, Candida parapsilosis, and Candida krusei and subsequently tested in a human intervention pilot trial involving 30 women with VVC. The probiotics used, L. fermentum LF10 (DSM 19187) and Lactobacillus acidophilus LA02 (DSM 21717), were administered by means of slow release effervescent

  2. Host defence against disseminated and invasive candida albicans infections.

    NARCIS (Netherlands)

    Vonk, A.G.

    2004-01-01

    The yeast Candida albicans is the primary etiologic agent of disseminated and invasive candidiasis. The incidence of disseminated and invasive candidiasis has paralleled the use of modern medical procedures that adversely affect the immune system, and highlights the difficulty of treating

  3. Susceptibility of Candida albicans Isolated from Blood to Wickerhamomyces anomalous Mycocins.

    Science.gov (United States)

    Paris, Ana Paula; Persel, Cristiane; Serafin, Cleber Fernando; de Cássia Garcia Simão, Rita; Gandra, Rinaldo Ferreira

    2016-12-01

    The occurrence of infections caused by Candida albicans in developed and developing countries and their resistance to some available antifungal drugs have been viewed as causing a great problem to human health worldwide. In order to find new researched molecules, there are some mycoses secreted by yeasts, especially mycocins produced by Wickerhamomyces anomalus with a broad antimicrobial spectrum of activity. Thus, this trial aimed at evaluating mycocins' activity obtained from environmental W. anomalus cell wall compared to thirty C. albicans strains isolated from blood. Mycocins were extracted from cell walls of three W. anomalus strains (WA40, WA45, and WA92). The 400 μg mL -1 concentration of WA40M1, WA45M2, and WA92M3 mycocin extracts showed the following respective activity results: 96.6, 96.6, and 90.0 % C. albicans strains. WA45M2 and WA92M3 mycocin extracts showed some activity in 3.3 % of C. albicans strains at 50 μg mL -1 concentration. Mycocins extracted from cell walls of three W. anomalus strains named as WA40, WA45, and WA92 showed antifungal activity compared to C. albicans and low degree of hemolysis.

  4. Yeast identification in floral nectar of Mimulus aurantiacus (Invited)

    Science.gov (United States)

    Kyauk, C.; Belisle, M.; Fukami, T.

    2009-12-01

    Nectar is such a sugar-rich resource that serves as a natural habitat in which microbes thrive. As a result, yeasts arrive to nectar on the bodies of pollinators such as hummingbirds and bees. Yeasts use the sugar in nectar for their own needs when introduced. This research focuses on the identification of different types of yeast that are found in the nectar of Mimulus aurantiacus (commonly known as sticky monkey-flower). Unopened Mimulus aurantiacus flower buds were tagged at Jasper Ridge and bagged three days later. Floral nectar was then extracted and plated on potato dextrose agar. Colonies on the plates were isolated and DNA was extracted from each sample using QIAGEN DNeasy Plant Mini Kit. The DNA was amplified through PCR and ran through gel electrophoresis. The PCR product was used to clone the nectar samples into an E.coli vector. Finally, a phylogenetic tree was created by BLAST searching sequences in GenBank using the Internal Transcribed Space (ITS) locus. It was found that 18 of the 50 identified species were Candida magnifica, 14 was Candida rancensis, 6 were Crytococcus albidus and there were 3 or less of the following: Starmella bombicola, Candida floricola, Aureobasidium pullulans, Pichia kluyvera, Metschnikowa cibodaserisis, Rhodotorua colostri, and Malassezia globosa. The low diversity of the yeast could have been due to several factors: time of collection, demographics of Jasper Ridge, low variety of pollinators, and sugar concentration of the nectar. The results of this study serve as a necessary first step for a recently started research project on ecological interactions between plants, pollinators, and nectar-living yeast. More generally, this research studies the use of the nectar-living yeast community as a natural microcosm for addressing basic questions about the role of dispersal and competitive and facilitative interactions in ecological succession.

  5. Diagnosis of bronchial asthma in sensitization to yeast-like fungus candida ablicans

    International Nuclear Information System (INIS)

    Burnasheva, R.Kh.; Gumerova, A.M.; Glushko, N.I.; Rakhmatullina, N.M.

    1994-01-01

    The peculiarities of bronchial asthma caused by hypersensitivity to antigens Candida albicans are studied. The allergen Candida albicans developed in the Kazan SIEM is used in the specific diagnosis. The various types of reactions in skin and provocative inhalation tests are analyzed, the role of specific immunoglobulins E is stressed

  6. Yeast species diversity in apple juice for cider production evidenced by culture-based method.

    Science.gov (United States)

    Lorenzini, Marilinda; Simonato, Barbara; Zapparoli, Giacomo

    2018-05-07

    Identification of yeasts isolated from apple juices of two cider houses (one located in a plain area and one in an alpine area) was carried out by culture-based method. Wallerstein Laboratory Nutrient Agar was used as medium for isolation and preliminary yeasts identification. A total of 20 species of yeasts belonging to ten different genera were identified using both BLAST algorithm for pairwise sequence comparison and phylogenetic approaches. A wide variety of non-Saccharomyces species was found. Interestingly, Candida railenensis, Candida cylindracea, Hanseniaspora meyeri, Hanseniaspora pseudoguilliermondii, and Metschnikowia sinensis were recovered for the first time in the yeast community of an apple environment. Phylogenetic analysis revealed a better resolution in identifying Metschnikowia and Moesziomyces isolates than comparative analysis using the GenBank or YeastIP gene databases. This study provides important data on yeast microbiota of apple juice and evidenced differences between two geographical cider production areas in terms of species composition.

  7. Phytase-active yeasts from grain-based food and beer.

    Science.gov (United States)

    Nuobariene, L; Hansen, A S; Jespersen, L; Arneborg, N

    2011-06-01

    To screen yeast strains isolated from grain-based food and beer for phytase activity to identify high phytase-active strains. The screening of phytase-positive strains was carried out at conditions optimal for leavening of bread dough (pH 5·5 and 30°C), in order to identify strains that could be used for the baking industry. Two growth-based tests were used for the initial testing of phytase-active strains. Tested strains belonged to six species: Saccharomyces cerevisiae, Saccharomyces pastorianus, Saccharomyces bayanus, Kazachstania exigua (former name Saccharomyces exiguus), Candida krusei (teleomorph Issachenkia orientalis) and Arxula adeninivorans. On the basis of initial testing results, 14 strains were selected for the further determination of extracellular and intracellular (cytoplasmic and/or cell-wall bound) phytase activities. The most prominent strains for extracellular phytase production were found to be S. pastorianus KVL008 (a lager beer strain), followed by S. cerevisiae KVL015 (an ale beer strain) and C. krusei P2 (isolated from sorghum beer). Intracellular phytase activities were relatively low in all tested strains. Herein, for the first time, beer-related strains of S. pastorianus and S. cerevisiae are reported as phytase-positive strains. The high level of extracellular phytase activity by the strains mentioned previously suggests them to be strains for the production of wholemeal bread with high content of bioavailable minerals. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

  8. [Yeast urinary tract infections. Multicentre study in 14 hospitals belonging to the Buenos Aires City Mycology Network].

    Science.gov (United States)

    Maldonado, Ivana; Arechavala, Alicia; Guelfand, Liliana; Relloso, Silvia; Garbasz, Claudia

    2016-01-01

    Urinary tract infections are a frequent ailment in patients in intensive care units. Candida and other yeasts cause 5-12% of these infections. The value of the finding of any yeast is controversial, and there is no consensus about which parameters are adequate for differentiating urinary infections from colonization or contamination. To analyse the epidemiological characteristics of patients with funguria, to determine potential cut-off points in cultures (to distinguish an infection from other conditions), to identify the prevalent yeast species, and to determine the value of a second urine sample. A multicentre study was conducted in intensive care units of 14 hospitals in the Buenos Aires City Mycology Network. The first and second samples of urine from every patient were cultured. The presence of white cells and yeasts in direct examination, colony counts, and the identification of the isolated species, were evaluated. Yeasts grew in 12.2% of the samples. There was no statistical correlation between the number of white cells and the fungal colony-forming units. Eighty five percent of the patients had indwelling catheters. Funguria was not prevalent in women or in patients over the age of 65. Candida albicans, followed by Candida tropicalis, were the most frequently isolated yeasts. Candida parapsilosis and Candida glabrata appeared less frequently. The same species were isolated in 70% of second samples, and in 23% of the cases the second culture was negative. It was not possible to determine a useful cut-off point for colony counts to help in the diagnosis of urinary infections. As in other publications, C. albicans, followed by C. tropicalis, were the most prevalent species. Copyright © 2015 Asociación Española de Micología. Published by Elsevier Espana. All rights reserved.

  9. Saccharomyces cerevisiae and non-Saccharomyces yeasts in grape varieties of the São Francisco Valley

    Directory of Open Access Journals (Sweden)

    Camila M.P.B.S. de Ponzzes-Gomes

    2014-06-01

    Full Text Available The aims of this work was to characterise indigenous Saccharomyces cerevisiae strains in the naturally fermented juice of grape varieties Cabernet Sauvignon, Grenache, Tempranillo, Sauvignon Blanc and Verdejo used in the São Francisco River Valley, northeastern Brazil. In this study, 155 S. cerevisiae and 60 non-Saccharomyces yeasts were isolated and identified using physiological tests and sequencing of the D1/D2 domains of the large subunit of the rRNA gene. Among the non-Saccharomyces species, Rhodotorula mucilaginosa was the most common species, followed by Pichia kudriavzevii, Candida parapsilosis, Meyerozyma guilliermondii, Wickerhamomyces anomalus, Kloeckera apis, P. manshurica, C. orthopsilosis and C. zemplinina. The population counts of these yeasts ranged among 1.0 to 19 x 10(5 cfu/mL. A total of 155 isolates of S. cerevisiae were compared by mitochondrial DNA restriction analysis, and five molecular mitochondrial DNA restriction profiles were detected. Indigenous strains of S. cerevisiae isolated from grapes of the São Francisco Valley can be further tested as potential starters for wine production.

  10. Gentamicin-Containing Peptone-Yeast Extract Medium for Cocultivation of Hartmannella vermiformis ATCC 50256 and Virulent Strains of Legionella pneumophila.

    Science.gov (United States)

    Wadowsky, R M; Wang, L; Laus, S; Dowling, J N; Kuchta, J M; States, S J; Yee, R B

    1995-12-01

    We evaluated the use of peptone-yeast extract (PY) medium, different strains of Hartmannella vermiformis, and gentamicin in a coculture system to improve the discrimination of virulent and avirulent strains of Legionella pneumophila. H. vermiformis ATCC 50256 was unique among four strains of H. vermiformis, in that it multiplied equally well in Medium 1034 and PY medium (Medium 1034 without fetal calf serum, folic acid, hemin, and yeast nucleic acid and with a 50% reduction of peptone). However, both a virulent strain of L. pneumophila and its avirulent derivative strain multiplied in cocultures when PY medium was used. The multiplication of this avirulent strain was greatly reduced by incorporating gentamicin (1 (mu)g/ml) into the cocultivation system. Five virulent-avirulent sets of L. pneumophila strains were then tested for multiplication in cocultures with H. vermiformis ATCC 50256 and the gentamicin-containing PY medium. Only the virulent strains multiplied. The modified cocultivation system can discriminate between virulent and avirulent strains of L. pneumophila.

  11. Radiation resistance of Candida parapsilosis

    International Nuclear Information System (INIS)

    Kristensen, H.

    1982-01-01

    The radiation resistance of 30 strains classified as Candida parapsilosis was examined. The strains originated partly from environments where ionizing radiation was used for research or routine purposes, partly from environments with no known possibility for selection of strains with unusually high radiation resistance. D-6 values between 1.5 and 2.4 Megarads were found when the cells were irradiated in the dried state, a D-6 value being the dose necessary to reduce the initial number of colony-forming units with a factor of 10 6 . The majority of D-6 values were between 1.9 and 2.1 Megarads. D-6 values for the cells irradiated in liquid media were about 2/3 of tose in the dried state. No difference in resistance was revealed depending on the origin of the strains examined. For radiation sterilization of medical products the demonstrated resistance of Candida parapsilosis might be of importance of routine use of minimum doses below 2.5 Megarads were to be accepted. (author)

  12. Phytase-producing capacity of yeasts isolated from traditional African fermented food products and PHYPk gene expression of Pichia kudriavzevii strains

    DEFF Research Database (Denmark)

    Greppi, Anna; Krych, Lukasz; Costantini, Antonella

    2015-01-01

    Phytate is known as a strong chelate of minerals causing their reduced uptake by the human intestine. Ninety-three yeast isolates from traditional African fermented food products, belonging to nine species (Pichia kudriavzevii, Saccharomyces cerevisiae, Clavispora lusitaniae, Kluyveromyces...... marxianus, Millerozyma farinosa, Candida glabrata, Wickerhamomyces anomalus, Hanseniaspora guilliermondii and Debaryomyces nepalensis) were screened for phytase production on solid and liquid media. 95% were able to grow in the presence of phytate as sole phosphate source, P. kudriavzevii being the best...

  13. Yeast diversity in rice-cassava fermentations produced by the indigenous Tapirapé people of Brazil

    DEFF Research Database (Denmark)

    Schwan, Rosane F.; Almeida, Euziclei G.; Souza-Dias, Maria Aparecida G.

    2007-01-01

    and peanuts. A fermentation using rice and cassava was conducted, and samples were collected at 4-h intervals for microbial analysis. The yeast population was low at the beginning of the fermentation and reached 6.9 x 10(7) CFU mL(-1) after 48 h. During the fermentation process common yeast species were......The Tapirapé people of the Tapi'itãwa tribe of Brazil produce several fermented foods and beverages, one of which is called 'cauim'. This beverage usually makes up the main staple food for adults and children. Several substrates are used in its production, including cassava, rice, corn, maize...... identified by sequencing of the D1/D2 domain of the large-subunit (26S) rRNA gene. The predominant yeast species found was Candida tropicalis. Candida intermedia, Candida parapsilosis, Pichia guilliermondii, Saccharomyces cerevisiae and Trichosporon asahii were also found in high numbers during...

  14. Performance of Chromogenic Candida agar and CHROMagar Candida in recovery and presumptive identification of monofungal and polyfungal vaginal isolates.

    Science.gov (United States)

    Ozcan, Kadri; Ilkit, Macit; Ates, Aylin; Turac-Bicer, Aygul; Demirhindi, Hakan

    2010-02-01

    Chromogenic Candida agar (OCCA) is a novel medium facilitating isolation and identification of Candida albicans, C. tropicalis, and C. krusei, as well as indicating polyfungal population in clinical samples. We compare the performance of OCCA, to CHROMagar Candida (CAC) and Sabouraud chloramphenicol agar (SCA). Vaginal swab samples from 392 women were simultaneously inoculated onto three study media. A total of 161 (41.1%) were found to be positive for fungi of which 140 (87%) were monofungal, and 21 (13%) polyfungal. One-hundred and fifty-seven samples (97.5%) were positive on CAC, 156 (96.9%) on OCCA, 148 (91.9%) on SCA and 144 (89.4%) samples were positive on all three media. The yeasts were identified by conventional methods including germ tube test, microscopic morphology on cornmeal-Tween 80 agar, and the commercial API 20C AUX. The 182 isolates were C. albicans (n = 104), C. glabrata (n = 51), C. krusei (n = 7), C. tropicalis (n = 5), C. famata (n = 3), C. kefyr (n = 3), C. zeylanoides (n = 3), C. colliculosa (n = 2), and other species of Candida (n = 4). Among the 21 polyfungal populations, 20 (95.2%) were detected in OCCA, 14 (66.7%) in CAC, and 13 (61.9%) in CAC and OCCA (P or=92.9% at 72 h. OCCA is more efficient and reliable for rapidly identifying C. albicans and polyfungal populations than CAC. However, CAC is more efficient for identifying C. krusei and C. tropicalis. A chromogenic agar with a higher isolation rate of yeasts and better detection of polyfungal populations than SCA, is suggested as a medium of first choice when available.

  15. [Performance evaluation of Rapid™ Yeast Plus (Remel) system from two different culture media].

    Science.gov (United States)

    Romeo, Ana M; Snitman, Gabriela V; Marucco, Andrea P; Ponce, Graciela Del V; Cataldi, Silvana P; Guelfand, Liliana I; Arechavala, Alicia

    Within the genus Candida, Candida albicans is the most commonly isolated species from clinical samples. Due to the emergence of other species which can show a higher index of antifungal resistance, a fast identification of these species is necessary. The aim of this work was to evaluate the performance of the RapID Yeast Plus system from two different subculture media formulations: Sabouraud dextrose agar adjusted by Emmons (the medium is indicated in the equipment insert) and Sabouraud glucose agar, which is the most frequently used in Buenos Aires City laboratories. One hundred and sixty-six clinical sample strains coming from different hospitals belonging to the Mycology Network of Buenos Aires City were studied. From the obtained results, we conclude that the conditions and culture medium indicated by the manufacturer should be followed. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  16. The combined rapid detection and species-level identification of yeasts in simulated blood culture using a colorimetric sensor array.

    Directory of Open Access Journals (Sweden)

    Nabin K Shrestha

    Full Text Available A colorimetric sensor array (CSA has been demonstrated to rapidly detect and identify bacteria growing in blood cultures by obtaining a species-specific "fingerprint" of the volatile organic compounds (VOCs produced during growth. This capability has been demonstrated in prokaryotes, but has not been reported for eukaryotic cells growing in culture. The purpose of this study was to explore if a disposable CSA could differentially identify 7 species of pathogenic yeasts growing in blood culture.Culture trials of whole blood inoculated with a panel of clinically important pathogenic yeasts at four different microorganism loads were performed. Cultures were done in both standard BacT/Alert and CSA-embedded bottles, after adding 10 mL of spiked blood to each bottle. Color changes in the CSA were captured as images by an optical scanner at defined time intervals. The captured images were analyzed to identify the yeast species. Time to detection by the CSA was compared to that in the BacT/Alert system.One hundred sixty-two yeast culture trials were performed, including strains of several species of Candida (Ca. albicans, Ca. glabrata, Ca. parapsilosis, and Ca. tropicalis, Clavispora (synonym Candida lusitaniae, Pichia kudriavzevii (synonym Candida krusei and Cryptococcus neoformans, at loads of 8.2 × 105, 8.3 × 103, 8.5 × 101, and 1.7 CFU/mL. In addition, 8 negative trials (no yeast were conducted. All negative trials were correctly identified as negative, and all positive trials were detected. Colorimetric responses were species-specific and did not vary by inoculum load over the 500000-fold range of loads tested, allowing for accurate species-level identification. The mean sensitivity for species-level identification by CSA was 74% at detection, and increased with time, reaching almost 95% at 4 hours after detection. At an inoculum load of 1.7 CFU/mL, mean time to detection with the CSA was 6.8 hours (17% less than with the BacT/Alert platform

  17. Alcohol-based quorum sensing plays a role in adhesion and sliding motility of the yeast Debaryomyces hansenii

    DEFF Research Database (Denmark)

    Gori, Klaus; Knudsen, Peter Boldsen; Nielsen, Kristian Fog

    2011-01-01

    and varied with growth conditions such as the availability of aromatic amino acids, ammonium sulphate, NaCl, pH and temperature. Tryptophol was only produced in the presence of tryptophane, whereas farnesol in general was not detectable. Especially, the type strain of D. hansenii (CBS767) had good adhesion...... detected from the end of exponential phase indicating that they are potential QS molecules in D. hansenii as previously shown for other yeast species. Yields of phenylethanol and tyrosol produced by D. hansenii were, however, lower than those produced by Candida albicans and Saccharomyces cerevisiae...

  18. Biochemical composition of the biomass of some yeasts

    Energy Technology Data Exchange (ETDEWEB)

    Filippova, T.V.; Tyurina, Z.P.

    1981-01-01

    The biochemical composition of Rhodotorula gracilis was dependent on the culture medium. Cultivation of the yeast on molasses, starch, and plant hydrolyzates gave a high biomass yield with high protein and carbohydrate contents and relatively low nucleic acid contents. Similar results were obtained with fodder yeasts: Candida tropicalis, C. scotti, and Sporobolomyces pararoseus. There were 17 amino acids in yeast biomass. The amino acid content of R. gracilis and C. scotti was 29-30 percent and 39 percent respectively. Both species were deficient in methionine.

  19. L-arabinose fermenting yeast

    Science.gov (United States)

    Zhang, Min; Singh, Arjun; Knoshaug, Eric; Franden, Mary Ann; Jarvis, Eric; Suominen, Pirkko

    2010-12-07

    An L-arabinose utilizing yeast strain is provided for the production of ethanol by introducing and expressing bacterial araA, araB and araD genes. L-arabinose transporters are also introduced into the yeast to enhance the uptake of arabinose. The yeast carries additional genomic mutations enabling it to consume L-arabinose, even as the only carbon source, and to produce ethanol. Methods of producing ethanol include utilizing these modified yeast strains. ##STR00001##

  20. Presence and changes in populations of yeasts on raw and processed poultry products stored at refrigeration temperature.

    Science.gov (United States)

    Ismail, S A; Deak, T; El-Rahman, H A; Yassien, M A; Beuchat, L R

    2000-12-05

    A study was undertaken to determine populations and profiles of yeast species on fresh and processed poultry products upon purchase from retail supermarkets and after storage at 5 degrees C until shelf life expiration, and to assess the potential role of these yeasts in product spoilage. Fifty samples representing 15 commercial raw, marinated, smoked, or roasted chicken and turkey products were analyzed. Yeast populations were determined by plating on dichloran rose bengal chloramphenicol (DRBC) agar and tryptone glucose yeast extract (TGY) agar. Proteolytic activity was determined using caseinate and gelatin agars and lipolytic activity was determined on plate count agar supplemented with tributyrin. Populations of aerobic microorganisms were also determined. Initial populations of yeasts (log10 cfu/g) ranged from less than 1 (detection limit) to 2.89, and increased by the expiration date to 0.37-5.06, indicating the presence of psychrotrophic species. Highest initial populations were detected in raw chicken breast, wings, and ground chicken, as well as in turkey necks and legs, whereas roasted chicken and turkey products contained less than 1 log10 cfu/g. During storage, yeast populations increased significantly (P chicken, ground chicken, liver, heart and gizzard, and in ground turkey and turkey sausage. Isolates (152 strains) of yeasts from poultry products consisted of 12 species. Yarrowia lipolytica and Candida zeylanoides were predominant, making up 39 and 26% of the isolates, respectively. Six different species of basidiomycetous yeasts representing 24% of the isolates were identified. Most Y. lipolytica strains showed strong proteolytic and lipolytic activities, whereas C. zeylanoides was weakly lipolytic. Results suggest that yeasts, particularly Y. lipolytica, may play a more prominent role than previously recognized in the spoilage of fresh and processed poultry stored at 5 degrees C.

  1. Toxicity of nalidixic acid on candida albicans, Saccharomyces cerevisiae, and Kluyveromyces lactis.

    Science.gov (United States)

    Sobieski, R J; Brewer, A R

    1976-03-01

    The antibacterial drug nalidixic acid (Nal) can suppress the growth of Candida albicans at levels of the drug normally found in urine. Growth suppression increases as drug levels are increased, and Nal also causes a similar proportional inhibition of the synthesis of all cellular macromolecules. However, growth temperature (25 versus 37 C) and the divalent cations Mg(2+) and Mn(2+) can increase C. albicans resistance to Nal. Also, nitrogen depletion of Candida shows that Nal-treated and untreated cells exhibit no difference in leucine uptake during readaptation to nitrogen. In Nal-treated, nitrogen-starved cells, ribonucleic acid and deoxyribonucleic acid (DNA) biosynthesis are less affected than in unstarved Nal-treated cells, but of the two nucleic acids DNA synthesis is the most affected. Nal-resistant strains of C. albicans exhibit a slight toxicity for macromolecular synthesis. Nal treatment of a synchronized population of Saccharomyces cerevisiae results in an increase in the culture mean doubling time of, at most, 20%, but Nal causes the loss of synchronous cell division. With a synchronized population of Kluyveromyces lactis, Nal causes an increase in the mean doubling time of upwards of 300%, with synchrony of cell division being maintained. It is known that S. cerevisiae asynchronously synthesizes mitochondrial DNA during the cell cycle, whereas with K. lactis it is synchronous. Thus, with C. albicans Nal toxicity is dependent both on the dose and the physiological state of the cell. Furthermore, Nal inhibits growth of yeast with synchronous mitochondrial DNA synthesis more adversely than yeast with asynchronous mitochondrial DNA synthesis.

  2. Low cost production of perdeuterated biomass using methylotrophic yeasts

    International Nuclear Information System (INIS)

    Haon, S.; Auge, S.; Tropis, M.; Milon, A.; Lindley, N.D.

    1993-01-01

    Three strains of methylotropic yeasts, Candida boidinii, Pichia angusta (previously Hansenula polymorpha) and Pichia pastoris, were studied for their capacity to grow on methanol in deuterated media. Growth rates, determined relative to the extent of deuteration of water and/or methanol, showed that water deuteration was the major limiting factor. After adaptation to deuterium by progressive transfer through media of increasing deuteration, growth rates were diminished relative to those obtained on hydrogenated media of identical salts composition: the two Pichia species retained the highest growth rates in the full deuterated medium. Perdeuterated biomass (16 g) was obtained in a 1 liter fed-batch fermentation and the extent of deuteration of isolated ergosterol has been shown to be 97.5% by mass spectrometric analysis. (Author)

  3. Candida albicans versus Candida dubliniensis: Why Is C. albicans More Pathogenic?

    LENUS (Irish Health Repository)

    Moran, Gary P

    2012-01-01

    Candida albicans and Candida dubliniensis are highly related pathogenic yeast species. However, C. albicans is far more prevalent in human infection and has been shown to be more pathogenic in a wide range of infection models. Comparison of the genomes of the two species has revealed that they are very similar although there are some significant differences, largely due to the expansion of virulence-related gene families (e.g., ALS and SAP) in C. albicans, and increased levels of pseudogenisation in C. dubliniensis. Comparative global gene expression analyses have also been used to investigate differences in the ability of the two species to tolerate environmental stress and to produce hyphae, two traits that are likely to play a role in the lower virulence of C. dubliniensis. Taken together, these data suggest that C. dubliniensis is in the process of undergoing reductive evolution and may have become adapted for growth in a specialized anatomic niche.

  4. Parameters oprimization for xylitol production by Candida tropicalis ...

    African Journals Online (AJOL)

    Ashraf

    2011-11-02

    Nov 2, 2011 ... Micro-determination of xylose in plasma. Analyst. 100. (1186): 12-15. Uhari M, Kontiokari Niemela T, Novel MA (1998). Use of xylitol sugar in preventing acute otitis media. Pediastrics, 102: 879-884. Vongsuvanlert V, Tani Y (1989). Xylitol production by methanol yeast. Candida boidinii (klocckera Sp) No.

  5. Hsp12p and PAU genes are involved in ecological interactions between natural yeast strains.

    Science.gov (United States)

    Rivero, Damaríz; Berná, Luisa; Stefanini, Irene; Baruffini, Enrico; Bergerat, Agnes; Csikász-Nagy, Attila; De Filippo, Carlotta; Cavalieri, Duccio

    2015-08-01

    The coexistence of different yeasts in a single vineyard raises the question on how they communicate and why slow growers are not competed out. Genetically modified laboratory strains of Saccharomyces cerevisiae are extensively used to investigate ecological interactions, but little is known about the genes regulating cooperation and competition in ecologically relevant settings. Here, we present evidences of Hsp12p-dependent altruistic and contact-dependent competitive interactions between two natural yeast isolates. Hsp12p is released during cell death for public benefit by a fast-growing strain that also produces a killer toxin to inhibit growth of a slow grower that can enjoy the benefits of released Hsp12p. We also show that the protein Pau5p is essential in the defense against the killer effect. Our results demonstrate that the combined action of Hsp12p, Pau5p and a killer toxin is sufficient to steer a yeast community. © 2015 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

  6. Antifungal activity of phlorotannins against dermatophytes and yeasts: approaches to the mechanism of action and influence on Candida albicans virulence factor.

    Directory of Open Access Journals (Sweden)

    Graciliana Lopes

    Full Text Available In the last few decades, fungal infections, particularly nosocomial, increased all around the world. This increment stimulated the search for new antifungal agents, especially those derived from nature. Among natural products, those from marine sources have gained prominence in the last years. Purified phlorotannins extracts from three brown seaweeds (Cystoseira nodicaulis (Withering M. Roberts, Cystoseira usneoides (Linnaeus M. Roberts and Fucus spiralis Linnaeus were screened for their antifungal activity against human pathogenic yeast and filamentous fungi. The purified phlorotannins extracts from the studied seaweeds displayed fungistatic and fungicidal activity against yeast and dermatophytes, respectively, pointing to their interest as anti-dermatophyte agent. C. albicans ATCC 10231 was the most susceptible among yeast, while Epidermophyton floccosum and Trichophyton rubrum were the most susceptible among dermatophytes. Since the antifungal mechanism constitutes an important strategy for limiting the emergence of resistance to the commercially available agents, the mechanism of action of purified phlorotannins extracts was approached. C. nodicaulis and C. usneoides seem to act by affecting the ergosterol composition of the cell membrane of yeast and dermatophyte, respectively. F. spiralis influenced the dermatophyte cell wall composition by reducing the levels of chitin. Phlorotannins also seem to affect the respiratory chain function, as all of the studied species significantly increased the activity of mitochondrial dehydrogenases and increased the incorporation of rhodamine 123 by yeast cells. Phlorotannins from F. spiralis inhibited the dimorphic transition of Candida albicans, leading to the formation of pseudohyphae with diminished capacity to adhere to epithelial cells. This finding is associated with a decrease of C. albicans virulence and capacity to invade host cells and can be potentially interesting for combined antifungal

  7. A phylogenetic analysis of the sugar porters in hemiascomycetous yeasts.

    Science.gov (United States)

    Palma, Margarida; Goffeau, André; Spencer-Martins, Isabel; Baret, Philippe V

    2007-01-01

    A total of 214 members of the sugar porter (SP) family (TC 2.A.1.1) from eight hemiascomycetous yeasts: Saccharomyces cerevisiae, Candida glabrata, Kluyveromyces lactis, Ashbya (Eremothecium) gossypii, Debaryomyces hansenii, Yarrowia lipolytica, Candida albicans and Pichia stipitis, were identified. The yeast SPs were classified in 13 different phylogenetic clusters. Specific sugar substrates could be allocated to nine phylogenetic clusters, including two novel TC clusters that are specific to fungi, i.e. the glycerol:H(+) symporter (2.A.1.1.38) and the high-affinity glucose transporter (2.A.1.1.39). Four phylogenetic clusters are identified by the preliminary fifth number Z23, Z24, Z25 and Z26 and the substrates of their members remain undetermined. The amplification of the SP clusters across the Hemiascomycetes reflects adaptation to specific carbon and energy sources available in the habitat of each yeast species. (c) 2007 S. Karger AG, Basel.

  8. Growth inhibitory action of ebselen on fluconazole-resistant Candida albicans: role of the plasma membrane H+-ATPase.

    Science.gov (United States)

    Billack, Blase; Santoro, Michelle; Lau-Cam, Cesar

    2009-06-01

    PMA1 is a yeast gene that codes for the plasma membrane H(+)-ATPase, a protein commonly referred to as Pma1p. Ebselen (2-phenyl-1,2-benzisoselenazol-3(2H)-one) is a synthetic selenium-containing compound that has recently been shown to display antimicrobial activity owing to its ability to inhibit Pma1p. Ebselen is able to block the activity of Pma1p not only in opportunistic pathogens such as Cryptococcus neoformans and Candida albicans but also in nonpathogenic yeasts such as Saccharomyces cerevisiae. A series of in vitro studies aimed at evaluating the antifungal activity of ebselen were performed. At low concentrations (ebselen was fungistatic against three strains of S. cerevisiae (IC(50) approximately 3 microM) and one fluconazole-resistant strain of C. albicans (IC(50) approximately 6 microM), and at a high concentration (30 microM) it was fungicidal against C. albicans. Moreover, ebselen was found to inhibit medium acidification by the fluconazole-resistant strain of C. albicans in a concentration-dependent manner. In comparison to currently used antifungal agents represented by azole (itraconazole, ketoconazole, fluconazole) and polyene (amphotericin B) compounds, ebselen was at least 10-fold more potent than fluconazole but less active than the other compounds tested. The present results suggest that the growth inhibitory activity of ebselen toward fluconazole-resistant yeast cells is due, at least in part, to inhibition of Pma1p. Ebselen may also serve as a useful agent in the treatment of infections caused by fluconazole-resistant fungi.

  9. Diversity of yeast strains of the genus Hanseniaspora in the winery environment: What is their involvement in grape must fermentation?

    Science.gov (United States)

    Grangeteau, Cédric; Gerhards, Daniel; Rousseaux, Sandrine; von Wallbrunn, Christian; Alexandre, Hervé; Guilloux-Benatier, Michèle

    2015-09-01

    Isolated yeast populations of Chardonnay grape must during spontaneous fermentation were compared to those isolated on grape berries and in a winery environment before the arrival of the harvest (air, floor, winery equipment) and in the air through time. Two genera of yeast, Hanseniaspora and Saccharomyces, were isolated in grape must and in the winery environment before the arrival of the harvest but not on grape berries. The genus Hanseniaspora represented 27% of isolates in the must and 35% of isolates in the winery environment. The isolates of these two species were discriminated at the strain level by Fourier transform infrared spectroscopy. The diversity of these strains observed in the winery environment (26 strains) and in must (12 strains) was considerable. 58% of the yeasts of the genus Hanseniaspora isolated in the must corresponded to strains present in the winery before the arrival of the harvest. Although the proportion and number of strains of the genus Hanseniaspora decreased during fermentation, some strains, all from the winery environment, subsisted up to 5% ethanol content. This is the first time that the implantation in grape must of populations present in the winery environment has been demonstrated for a non-Saccharomyces genus. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Microbial detoxification of bifenthrin by a novel yeast and its potential for contaminated soils treatment.

    Directory of Open Access Journals (Sweden)

    Shaohua Chen

    Full Text Available Bifenthrin is one the most widespread pollutants and has caused potential effect on aquatic life and human health, yet little is known about microbial degradation in contaminated regions. A novel yeast strain ZS-02, isolated from activated sludge and identified as Candida pelliculosa based on morphology, API test and 18S rDNA gene analysis, was found highly effective in degrading bifenthrin over a wide range of temperatures (20-40 °C and pH (5-9. On the basis of response surface methodology (RSM, the optimal degradation conditions were determined to be 32.3 °C and pH 7.2. Under these conditions, the yeast completely metabolized bifenthrin (50 mg · L(-1 within 8 days. This strain utilized bifenthrin as the sole carbon source for growth as well as co-metabolized it in the presence of glucose, and tolerated concentrations as high as 600 mg · L(-1 with a q(max, K(s and K(i of 1.7015 day(-1, 86.2259 mg · L(-1 and 187.2340 mg · L(-1, respectively. The yeast first degraded bifenthrin by hydrolysis of the carboxylester linkage to produce cyclopropanecarboxylic acid and 2-methyl-3-biphenylyl methanol. Subsequently, 2-methyl-3-biphenylyl methanol was further transformed by biphenyl cleavage to form 4-trifluoromethoxy phenol, 2-chloro-6-fluoro benzylalcohol, and 3,5-dimethoxy phenol, resulting in its detoxification. Eventually, no persistent accumulative product was detected by gas chromatopraphy-mass spectrometry (GC-MS analysis. This is the first report of a novel pathway of degradation of bifenthrin by hydrolysis of ester linkage and cleavage of biphenyl in a microorganism. Furthermore, strain ZS-02 degraded a variety of pyrethroids including bifenthrin, cyfluthrin, deltamethrin, fenvalerate, cypermethrin, and fenpropathrin. In different contaminated soils introduced with strain ZS-02, 65-75% of the 50 mg · kg(-1 bifenthrin was eliminated within 10 days, suggesting the yeast could be a promising candidate for remediation of environments affected

  11. Microbial detoxification of bifenthrin by a novel yeast and its potential for contaminated soils treatment.

    Science.gov (United States)

    Chen, Shaohua; Luo, Jianjun; Hu, Meiying; Geng, Peng; Zhang, Yanbo

    2012-01-01

    Bifenthrin is one the most widespread pollutants and has caused potential effect on aquatic life and human health, yet little is known about microbial degradation in contaminated regions. A novel yeast strain ZS-02, isolated from activated sludge and identified as Candida pelliculosa based on morphology, API test and 18S rDNA gene analysis, was found highly effective in degrading bifenthrin over a wide range of temperatures (20-40 °C) and pH (5-9). On the basis of response surface methodology (RSM), the optimal degradation conditions were determined to be 32.3 °C and pH 7.2. Under these conditions, the yeast completely metabolized bifenthrin (50 mg · L(-1)) within 8 days. This strain utilized bifenthrin as the sole carbon source for growth as well as co-metabolized it in the presence of glucose, and tolerated concentrations as high as 600 mg · L(-1) with a q(max), K(s) and K(i) of 1.7015 day(-1), 86.2259 mg · L(-1) and 187.2340 mg · L(-1), respectively. The yeast first degraded bifenthrin by hydrolysis of the carboxylester linkage to produce cyclopropanecarboxylic acid and 2-methyl-3-biphenylyl methanol. Subsequently, 2-methyl-3-biphenylyl methanol was further transformed by biphenyl cleavage to form 4-trifluoromethoxy phenol, 2-chloro-6-fluoro benzylalcohol, and 3,5-dimethoxy phenol, resulting in its detoxification. Eventually, no persistent accumulative product was detected by gas chromatopraphy-mass spectrometry (GC-MS) analysis. This is the first report of a novel pathway of degradation of bifenthrin by hydrolysis of ester linkage and cleavage of biphenyl in a microorganism. Furthermore, strain ZS-02 degraded a variety of pyrethroids including bifenthrin, cyfluthrin, deltamethrin, fenvalerate, cypermethrin, and fenpropathrin. In different contaminated soils introduced with strain ZS-02, 65-75% of the 50 mg · kg(-1) bifenthrin was eliminated within 10 days, suggesting the yeast could be a promising candidate for remediation of environments affected by

  12. Genome Sequences of Industrially Relevant Saccharomyces cerevisiae Strain M3707, Isolated from a Sample of Distillers Yeast and Four Haploid Derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Steven D.; Klingeman, Dawn M.; Johnson, Courtney M.; Clum, Alicia; Aerts, Andrea; Salamov, Asaf; Sharma, Aditi; Zane, Matthew; Barry, Kerrie; Grigoriev, Igor V.; Davison, Brian H.; Lynd, Lee R.; Gilna, Paul; Hau, Heidi; Hogsett, David A.; Froehlich, Allan C.

    2013-04-19

    Saccharomyces cerevisiae strain M3707 was isolated from a sample of commercial distillers yeast, and its genome sequence together with the genome sequences for the four derived haploid strains M3836, M3837, M3838, and M3839 has been determined. Yeasts have potential for consolidated bioprocessing (CBP) for biofuel production, and access to these genome sequences will facilitate their development.

  13. Preliminary X-Ray Crystallographic Studies of the N-Terminal Domains of Hsp104 from Yeast Candida albicans and Saccharomyces cerevisiae

    Science.gov (United States)

    Wang, P.; Li, J.; Sha, B.

    2017-12-01

    Yeast Hsp104 is an ATP-dependent molecular chaperone, which can solublize and rescue denatured proteins from aggregates into active form by cooperating with Hsp70 and Hsp40 chaperones. Moreover, overexpression of Hsp104 of Saccharomyces cerevisiae (ScHsp104) cures the yeast [ PSI +] prion due to the completely dissolution of the prion seeds, demonstrating ScHsp104's potential to clear amyloid-like protein aggregates, thus making ScHsp104 a promising medication approach for human amyloidogenic neurodegenerative diseases. Because the working mechanisms for ScHsp104's activities have not been clearly elucidated yet, crystallographic determination of ScHsp104 stands for great significance. Here, the expression, purification and crystallization of the N-terminal domains of Hsp104 from yeast Candida albicans (CaHsp104N) and S. cerevisiae (ScHsp104N) are described. The CaHsp104N crystals diffracted to 1.54 Å and belonged to the sp. gr. P3221 or P3121, with unit cell parameters of a = 55.213 Å, c = 109.451 Å. The data of the ScHsp104N crystals were collected to the resolution of 2.53 Å in the sp. gr. C2, with unit cell parameters a = 148.587 Å, b = 66.255 Å, c = 74.577 Å, β = 107.369°. The phase of ScHsp104N is determined by the molecular replacement method using CaHsp104N as the search model.

  14. Comparison of dielectric barrier discharge modes fungicidal effect on candida albicans growth

    International Nuclear Information System (INIS)

    Slama, J.; Kriha, V.; Fantova, V.; Julak, J.

    2013-01-01

    Filamentary and quasi-homogeneous mode of dielectric barrier discharge (DBD) was investigated as a plasma source with fungicidal effect on Candida albicans yeast inoculated on Sabouraud agar wafers. As compared with the filamentary DBD mode, the quasi-homogeneous mode had significantly better results: shorter exposition time needed for inhibiting C. albicans yeast, moreover the quasi-homogeneous mode had gentle influence on the agar surface structure.

  15. Species-specific activation of Cu/Zn SOD by its CCS copper chaperone in the pathogenic yeast Candida albicans.

    Science.gov (United States)

    Gleason, Julie E; Li, Cissy X; Odeh, Hana M; Culotta, Valeria C

    2014-06-01

    Candida albicans is a pathogenic yeast of important public health relevance. Virulence of C. albicans requires a copper and zinc containing superoxide dismutase (SOD1), but the biology of C. albicans SOD1 is poorly understood. To this end, C. albicans SOD1 activation was examined in baker's yeast (Saccharomyces cerevisiae), a eukaryotic expression system that has proven fruitful for the study of SOD1 enzymes from invertebrates, plants, and mammals. In spite of the 80% similarity between S. cerevisiae and C. albicans SOD1 molecules, C. albicans SOD1 is not active in S. cerevisiae. The SOD1 appears incapable of productive interactions with the copper chaperone for SOD1 (CCS1) of S. cerevisiae. C. albicans SOD1 contains a proline at position 144 predicted to dictate dependence on CCS1. By mutation of this proline, C. albicans SOD1 gained activity in S. cerevisiae, and this activity was independent of CCS1. We identified a putative CCS1 gene in C. albicans and created heterozygous and homozygous gene deletions at this locus. Loss of CCS1 resulted in loss of SOD1 activity, consistent with its role as a copper chaperone. C. albicans CCS1 also restored activity to C. albicans SOD1 expressed in S. cerevisiae. C. albicans CCS1 is well adapted for activating its partner SOD1 from C. albicans, but not SOD1 from S. cerevisiae. In spite of the high degree of homology between the SOD1 and CCS1 molecules in these two fungal species, there exists a species-specific barrier in CCS-SOD interactions which may reflect the vastly different lifestyles of the pathogenic versus the noninfectious yeast.

  16. Optimization of Culture Medium for the Growth of Candida sp. and Blastobotrys sp. as Starter Culture in Fermentation of Cocoa Beans (Theobroma cacao) Using Response Surface Methodology (RSM).

    Science.gov (United States)

    Mahazar, N H; Zakuan, Z; Norhayati, H; MeorHussin, A S; Rukayadi, Y

    2017-01-01

    Inoculation of starter culture in cocoa bean fermentation produces consistent, predictable and high quality of fermented cocoa beans. It is important to produce healthy inoculum in cocoa bean fermentation for better fermented products. Inoculum could minimize the length of the lag phase in fermentation. The purpose of this study was to optimize the component of culture medium for the maximum cultivation of Candida sp. and Blastobotrys sp. Molasses and yeast extract were chosen as medium composition and Response Surface Methodology (RSM) was then employed to optimize the molasses and yeast extract. Maximum growth of Candida sp. (7.63 log CFU mL-1) and Blastobotrys sp. (8.30 log CFU mL-1) were obtained from the fermentation. Optimum culture media for the growth of Candida sp., consist of 10% (w/v) molasses and 2% (w/v) yeast extract, while for Blastobotrys sp., were 1.94% (w/v) molasses and 2% (w/v) yeast extract. This study shows that culture medium consists of molasses and yeast extract were able to produce maximum growth of Candida sp. and Blastobotrys sp., as a starter culture for cocoa bean fermentation.

  17. Antifungal susceptibility testing of vaginal candida isolates: the broth microdilution method

    Directory of Open Access Journals (Sweden)

    Mahmoudi Rad M

    2010-02-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Vulvovaginal candidiasis is a common mucosal infection among immunocompetent, healthy women, and is caused by opportunistic yeasts that belong to genus Candida. In this study, we isolated and identified the Candida species in the vagina of patients who admitted in Gynecology Department of Mahdieh Hospital in Tehran, Iran to evaluate the in vitro activities of fluconazole, miconazole, itraconazole and flucytosine against 191 clinical Candida isolates by the NCCLS microdilution method."n"nMethods: 191 Candida were isolated from vaginal secretions and identified with conventional mycological methods in the diagnosis of Candida species. The identity of all strains was confirmed genotypically by multiplex PCR. In vitro susceptibility testing of vaginal Candida isolates was performed by the NCCLS broth microdilution method. The results were read at 48 h."n"nResults: Most C. albicans isolates (>90% were sensitive in vitro to the antifungal agents tested. Most C. glabrata isolates showed sensitivity to miconazole and then flucytosine while they were more resistant to Itraconazole and fluconazole. Many isolates of C. tropicalis were susceptible to miconazole and then fluconazole. They showed a little resistance to

  18. Antimicrobial Effect of Copper Oxide Nanoparticles on Some Oral Bacteria and Candida Species

    Directory of Open Access Journals (Sweden)

    Amiri M

    2017-03-01

    Full Text Available Statement of Problem: Acid producing bacteria including Streptococcus mutans and lactobacilli cause tooth demineralization and lead to tooth decay. Also, oral colonization of the species of Candida has been reported in many studies that are resistant to antifungal agents. Objectives: In this study, antibacterial and antifungal effects of nano-CuO were studied against some oral bacteria and yeast fungi. Materials and Methods: The minimum inhibitory concentrations (MICs of copper oxide nanoparticles (CuO NPs for oral bacterial and fungal test strains were determined in 96-well microtiter plate technique. The agar diffusion test (ADT was employed to assess the antifungal properties of nystatin. Results: The MIC50 value of CuO NPs was determined at the range of 1–10 µg/ml for S. mutans, < 1 µg/ml for L. acidophilus, and 10 µg/ml for L. casei. Higher concentrations of CuO NPs (100-1000 µg/ml were effective on the bacterial cell growth, resulting in 100% reduction in the optical density in TSB medium. The cells of Candida albicans, C. krusei and C. glabrata were treated with CuO NPs and the results showed a decrease in fungal growth at a concentration of 1-1000 µg/ml in TSB medium. The MIC50 value of CuO NPs was determined 1000 µg/ml for three species of Candida. The diameter of growth inhibition zones of 1100 µg/ml nystatin was obtained 15-21 mm for clinical isolates of three species of Candida. Conclusions: With respect to the potential bactericidal activity of CuO NPs on various cariogenic bacteria examined in this study, these NPs could be introduce as a candidate control agent for preventing dental caries or dental infections. In our study, on the other hand, Nano copper oxide had a weak effect on the candida species.

  19. Discriminative power of fatty acid methyl ester (FAME) analysis using the microbial identification system (MIS) for Candida (Torulopsis) glabrata and Saccharomyces cerevisiae.

    Science.gov (United States)

    Peltroche-Llacsahuanga, H; Schmidt, S; Lütticken, R; Haase, G

    2000-12-01

    Candida (Torulopsis) glabrata is frequently isolated in cases of fungal infection and commonly shows acquired or innate fluconazole resistance. Saccharomyces cerevisiae, an emerging opportunistic yeast pathogen, causes serious systemic infections in immunocompromised, and vaginitis and superficial infections in immunocompetent patients. For both species reliable identification in the routine laboratory is mandatory, but species identification of strains, e.g. trehalose-negative C. glabrata, may be difficult. Therefore, gas-liquid chromatography (GLC) of whole cell fatty acid methyl ester (FAME) profiles, that is independent of assimilation profiles of strains and suitable for reliable and rapid identification of clinically important yeasts, was applied. However, frequent misidentification of C. glabrata as S. cerevisiae has been reported when using the Yeast Clinical Database of MIS. Accuracy of MIS identification may be strongly influenced by the amounts of cell mass analyzed. Therefore, the present study compared the MIS results of these two yeasts achieved with different cell masses. Primarily we optimized, especially with respect to cost-effectiveness, the recommended streaking technique yielding a maximal recovery of 90-130 mg of cell mass from one plate, enabling testing of poor growing strains of C. glabrata. For all C. glabrata strains tested (n = 10) the highest identification scores (SI [Similarity Index] range 0.525-0.963, median 0.832) were achieved with 30 to 45 mg of cell mass. Only 5 of 10 S. cerevisiae strains revealed good library comparisons (SI > or = 0.5) when using 30 mg of cell mass, whereas with 45 mg all strains but two revealed this SI-level. For S. cerevisiae a higher amount of cell mass processed (up to 90 mg) was correlated with better identification scores (SI range using 90 mg: 0.464-0.870, median, 0.737). Several passages prior to FAME analysis of C. glabrata strains on recommended media revealed narrowing of SI ranges, but

  20. Staphylococcus-Candida interaction models: antibiotic resistance testing and host interactions

    NARCIS (Netherlands)

    Scheres, C.R.; Krom, B.P.; Calderone, R.; Cihlar, R.

    2016-01-01

    The fungus Candida albicans and bacterium Staphylococcus aureus can coexist in polymicrobial biofilms. S. aureus attaches strongly to hyphae, but not to the yeast form, of C. albicans with important consequences for virulence. Hyphae-associated S. aureus is less susceptible to antibiotic treatment.