WorldWideScience

Sample records for pseudomonas bacterial fermentation

  1. Quantitative approach to track lipase producing Pseudomonas sp. S1 in nonsterilized solid state fermentation.

    Science.gov (United States)

    Sahoo, R K; Subudhi, E; Kumar, M

    2014-06-01

    Proliferation of the inoculated Pseudomonas sp. S1 is quantitatively evaluated using ERIC-PCR during the production of lipase in nonsterile solid state fermentation an approach to reduce the cost of enzyme production. Under nonsterile solid state fermentation with olive oil cake, Pseudomonas sp. S1 produced 57·9 IU g(-1) of lipase. DNA fingerprints of unknown bacterial isolates obtained on Bushnell Haas agar (BHA) + tributyrin exactly matched with that of Pseudomonas sp. S1. Using PCR-based enumeration, population of Pseudomonas sp. S1 was proliferated from 7·6 × 10(4) CFU g(-1) after 24 h to 4·6 × 10(8) CFU g(-1) after 96 h, which tallied with the maximum lipase activity as compared to control. Under submerged fermentation (SmF), Pseudomonas sp. S1 produced maximum lipase (49 IU ml(-1) ) using olive oil as substrate, while lipase production was 9·754 IU ml(-1) when Pseudomonas sp. S1 was grown on tributyrin. Optimum pH and temperature of the crude lipase was 7·0 and 50°C. Crude enzyme activity was 71·2% stable at 50°C for 360 min. Pseudomonas sp. S1 lipase was also stable in methanol showing 91·6% activity in the presence of 15% methanol, whereas 75·5 and 51·1% of activity were retained in the presence of 20 and 30% methanol, respectively. Thus, lipase produced by Pseudomonas sp. S1 is suitable for the production of biodiesel as well as treatment of oily waste water. This study presents the first report on the production of thermophilic organic solvent tolerant lipase using agro-industry waste in nonsterile solid state fermentation. Positive correlation between survival of Pseudomonas sp. S1 and lipase production under nonsterile solid state fermentation was established, which may emphasize the need to combine molecular tools and solid state fermentation in future studies. Our study brings new insights into the lipase production in cost-effective manner, which is an industrially relevant approach. © 2014 The Society for Applied Microbiology.

  2. Potential of bacterial fermentation as a biosafe method of improving ...

    African Journals Online (AJOL)

    The use of fermented liquid feeds in monogastric animal nutrition is regarded as one of the biosafe methods of animal production. This paper examines bacterial fermentation of feed substrates for production of fermented liquid feeds for pigs and moist feeds for poultry. Emphasis is placed on the interplay of factors affecting ...

  3. Bacterial Community Structure and Dynamics During Corn-Based Bioethanol Fermentation.

    Science.gov (United States)

    Li, Qing; Heist, E Patrick; Moe, Luke A

    2016-02-01

    Corn-based fuel ethanol facilities mix enzymatically treated, gelatinized corn starch with water to generate a "mash" that is used as the substrate in large-scale (∼500,000 gallon) yeast-based fermentations. In contrast to other food and beverage fermentations (e.g., cheese, wine), bioethanol production is presumed to be optimal when bacteria are absent from the fermentation-thus maximizing conversion of glucose to ethanol-yet the facilities are not sterilized. Culture-based analysis has suggested that lactic acid bacteria occupy this niche and, under certain circumstances, can outcompete the dedicated fermentation yeast for nutrients. Here, we use 16S rRNA gene amplicon sequencing to probe bacterial community structure during bioethanol fermentation. Nineteen total batches from five corn-based fuel ethanol fermentation facilities were analyzed. From each batch, five samples were taken. This includes the contents of the yeast propagation tank at inoculation, three samples taken at intervals during the fermentation, and a sample taken at the end of fermentation. Bacterial community structure was compared with time, between facility, between fermentor, between batches from the same fermentor, and against environmental variables within each fermentation. Communities were dominated by members of the Firmicutes and Proteobacteria phyla, with lactic acid bacteria dominating the communities in two of the five facilities. In the other facilities, Proteobacteria (largely members of the Pseudomonas and Escherichia-Shigella genera) outcompete the lactic acid bacteria. In most cases, the yeast propagation tank inoculum imparted a rich bacterial community, but the batches vary regarding whether this inoculum was the primary driver of the fermentation community structure.

  4. Pseudomonas aeruginosa Biofilm, a Programmed Bacterial Life for Fitness.

    Science.gov (United States)

    Lee, Keehoon; Yoon, Sang Sun

    2017-06-28

    A biofilm is a community of microbes that typically inhabit on surfaces and are encased in an extracellular matrix. Biofilms display very dissimilar characteristics to their planktonic counterparts. Biofilms are ubiquitous in the environment and influence our lives tremendously in both positive and negative ways. Pseudomonas aeruginosa is a bacterium known to produce robust biofilms. P. aeruginosa biofilms cause severe problems in immunocompromised patients, including those with cystic fibrosis or wound infection. Moreover, the unique biofilm properties further complicate the eradication of the biofilm infection, leading to the development of chronic infections. In this review, we discuss the history of biofilm research and general characteristics of bacterial biofilms. Then, distinct features pertaining to each stage of P. aeruginosa biofilm development are highlighted. Furthermore, infections caused by biofilms on their own or in association with other bacterial species (i.e., multispecies biofilms) are discussed in detail.

  5. Development of a lipase fermentation process that uses a recombinant Pseudomonas alcaligenes strain

    NARCIS (Netherlands)

    Gerritse, G; Hommes, R.W J; Quax, Wim

    Pseudomonas alcaligenes M-l secretes an alkaline lipase, which has excellent characteristics for the removal of fatty stains under modern washing conditions. A fed-batch fermentation process based on the secretion of the alkaline lipase from P. alcaligenes was developed. Due to the inability of P.

  6. Effects of bacterial inoculation on the fermentation characteristics ...

    African Journals Online (AJOL)

    The effect of bacterial inoculation on the fermentation and aerobic stability of two ensiled whole plant soybean (WPSB) cultivars was determined in a 2 x 2 factorial design. Two WPSB cultivars, Link LF6466 and Pannar 522 RR, were harvested at their R6 growth stage, chopped to 25 mm and ensiled in 1.5 L anaerobic jars.

  7. Effects of bacterial inoculation on the fermentation characteristics ...

    African Journals Online (AJOL)

    DNkosi

    2016-05-11

    May 11, 2016 ... The chopped forages were treated with or without the bacterial inoculant Lalsil Dry (LD) and treatments were as .... addition, samples collected on days 0 and 90 were used to determine nutritive values and fermentation ... concentration was determined using heat stable α-amylase (Sigma-Aldrich Co. LTD.

  8. Survival of bacterial enteric pathogens in traditional fermented foods.

    Science.gov (United States)

    Simango, C; Rukure, G

    1992-07-01

    The survival of strains of bacterial enteric pathogens was investigated in two traditional fermented foods (mahewu and sour porridge) and in unfermented porridge. The foods were inoculated with cell suspensions of Salmonella, Shigella, Campylobacter, Aeromonas species and pathogenic Escherichia coli which had a final concentration of 10(6)-10(7) cfu/ml of food. None of the strains of Aeromonas and Campylobacter were detected in mahewu and sour porridge 20 min after inoculation. The salmonellas were not found 4 h after inoculation in either fermented foods but the shigellas and pathogenic E. coli strains were more tolerant to the low pH of the fermented foods. Some of the shigellas and pathogenic E. coli strains survived for 24 h after inoculation but showed a sharp decrease in numbers. All the strains of the enteric pathogens survived for 24 h in the unfermented porridge and increased in the numbers except for campylobacters, the numbers of which declined. These results suggest that the traditional fermented foods have bacteriostatic and bactericidal properties and are unlikely to play a major role in the transmission of bacterial enteric pathogens.

  9. Functional bacterial amyloid increases Pseudomonas biofilm hydrophobicity and stiffness

    DEFF Research Database (Denmark)

    Zeng, Guanghong; Vad, Brian S; Dueholm, Morten S

    2015-01-01

    hydrophobicity and mechanical properties. Using atomic force microscopy imaging and force spectroscopy, we show that the amyloid renders individual cells more resistant to drying and alters their interactions with hydrophobic probes. Importantly, amyloid makes Pseudomonas more hydrophobic and increases biofilm...

  10. Biofilm Formation Mechanisms of Pseudomonas aeruginosa Predicted via Genome-Scale Kinetic Models of Bacterial Metabolism

    Science.gov (United States)

    2016-03-15

    RESEARCH ARTICLE Biofilm Formation Mechanisms of Pseudomonas aeruginosa Predicted via Genome-Scale Kinetic Models of Bacterial Metabolism Francisco G...jaques.reifman.civ@mail.mil Abstract A hallmark of Pseudomonas aeruginosa is its ability to establish biofilm -based infections that are difficult to...eradicate. Biofilms are less susceptible to host inflammatory and immune responses and have higher antibiotic tolerance than free-living planktonic

  11. Production of rhamnolipids by semi-solid-state fermentation with Pseudomonas aeruginosa RG18 for heavy metal desorption.

    Science.gov (United States)

    Wu, Jianrong; Zhang, Jingbo; Wang, Panpan; Zhu, Li; Gao, Minjie; Zheng, Zhiyong; Zhan, Xiaobei

    2017-11-01

    Foaming problem and cost of substrate limit the commercial application of rhamnolipids, a potential biosurfactant produced by Pseudomonas aeruginosa. We explored the production of rhamnolipids by a semi-solid-state (SSS) fermentation strategy with glycerol as carbon source and rapeseed/wheat bran as matrix, along with the capacity of the produced rhamnolipids to solubilize lead and cadmium in aqueous solution. Structural analysis by MALDI-TOF MS indicated the increased proportion of mono-rhamnolipids from SSS fermentation. E24 results showed the stronger emulsification capacity and reduced water tension of the SSS fermentation product. Rhamnolipids from SSS fermentation can desorb lead/cadmium from contaminated soil effectively and heavy metals in exchangeable and carbonate forms were easily removed. Our findings suggest that SSS fermentation is an alternative for the economical production of rhamnolipids and the product can be used to solubilize heavy metals from soils.

  12. Bacterial succession and the dynamics of volatile compounds during the fermentation of Chinese rice wine from Shaoxing region.

    Science.gov (United States)

    Liu, Shuang Ping; Mao, Jian; Liu, Yun Ya; Meng, Xiang Yong; Ji, Zhong Wei; Zhou, Zhi Lei; Ai-lati, Aisikaer

    2015-12-01

    Shaoxing rice wine is one of the most typical representatives of Chinese rice wine. It is brewed under non-sterile condition with various microorganism growing at the same time and forms a special flavor. The aims of this study was to monitor the bacterial succession by MiSeq pyrosequencing and the volatile compound dynamics by HS-SPME/GC–MS during brewing process. Moreover, the volatile compounds and bacterial community were analyzed by partial least squares regression to evaluate the effect of bacteria on volatile compounds formation. The results showed that there were ten dominating genera during Shaoxing rice wine fermentation process. Ten genera, Bacillus, Leuconostoc, Lactococcus, Weissella, Thermoactinomyces, Pseudomonas, Saccharopolyspora, Staphylococcus, Enterobacter and Lactobacillus, were identified as the main bacteria. The Bacillus and Lactobacillus dominated the Chinese rice wine ecosystems. In addition, a total of 64 volatile compounds were identified, mainly esters, alcohols, carbonyl compound and phenols. Pseudomonas were involved in synthesis of a wide variety of volatile compounds. Thermoactinomyces, Bacillus and Lactococcus also played critical roles in the formation of volatile compounds.

  13. Genome-wide analysis of bacterial determinants of plant growth promotion and induced systemic resistance by Pseudomonas fluorescens

    NARCIS (Netherlands)

    Cheng, Xu; Etalo, Desalegn W.; van de Mortel, Judith E.; Dekkers, Ester; Nguyen, Linh; Medema, Marnix H; Raaijmakers, Jos M.

    2017-01-01

    Pseudomonas fluorescens strain SS101 (Pf.SS101) promotes growth of Arabidopsis thaliana, enhances greening and lateral root formation, and induces systemic resistance (ISR) against the bacterial pathogen Pseudomonas syringae pv. tomato (Pst). Here, targeted and untargeted approaches were adopted to

  14. Pseudomonas fluorescens subsp. cellulosa: an alternative model for bacterial cellulase.

    Science.gov (United States)

    Hazlewood, G P; Laurie, J I; Ferreira, L M; Gilbert, H J

    1992-03-01

    Pseudomonas fluorescens subsp. cellulosa, a Gram-negative soil bacterium, can utilize crystalline cellulose or xylan as main sources of carbon and energy. Synthesis of endoglucanases and xylanases is induced by Avicel, filter paper, carboxymethylcellulose or xylan and is repressed by cellobiose, glucose or xylose. These enzymes are secreted into the culture supernatant fluid and do not form aggregates or associate with the cell surface. Cells of Ps. fluorescens subsp. cellulosa do not adhere to cellulose. In cultures containing Avicel or filter paper, a significant proportion of the secreted cellulase and xylanase activities becomes tightly bound to the insoluble cellulose. Western blotting has revealed that endoglucanase B, xylanase A and a cellodextrinase encoded by genes previously isolated from Ps. fluorescens subsp. cellulosa and expressed in Escherichia coli, are synthesized by the pseudomonad under a variety of conditions. These enzymes appear to be post-translationally modified, probably through glycosylation. Overall, it appears that the cellulase/hemicellulase system of Ps. fluorescens subsp. cellulosa differs from the model established for celluloytic anaerobes such as Clostridium thermocellum.

  15. Using wastewater after lipid fermentation as substrate for bacterial cellulose production by Gluconacetobacter xylinus.

    Science.gov (United States)

    Huang, Chao; Guo, Hai-Jun; Xiong, Lian; Wang, Bo; Shi, Si-Lan; Chen, Xue-Fang; Lin, Xiao-Qing; Wang, Can; Luo, Jun; Chen, Xin-De

    2016-01-20

    In this study, lipid fermentation wastewater (fermentation broth after separation with yeast biomass) with high Chemical Oxygen Demand (COD) value of 25,591 mg/L was used as substrate for bacterial cellulose (BC) production by Gluconacetobacter xylinus for the first time. After 5 days of fermentation, the highest BC yield (0.659 g/L) was obtained. Both monosaccharide and polysaccharides present in lipid fermentation wastewater could be utilized by G. xylinus simultaneously during fermentation. By this bioconversion, 30.0% of COD could be removed after 10 days of fermentation and the remaining wastewater could be used for further BC fermentation. The crystallinity of BC samples in lipid fermentation wastewater increased gradually during fermentation but overall the environment of lipid fermentation wastewater showed small influence on BC structure by comparison with that in traditional HS medium by using FE-SEM, FTIR, and XRD. By this work, the possibility of using lipid fermentation wastewater containing low value carbohydrate polymer (extracellular polysaccharides) for high value carbohydrate polymer (BC) production was proven. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Induction of Callose Deposition in Tobacco (Nicotiana tabacum by Bacterial Lipopolysaccharide Pseudomonas syringae pv. tabaci and Pseudomonas syringae pv. glycinea

    Directory of Open Access Journals (Sweden)

    Pipit Marianingsih

    2014-12-01

    Full Text Available Lipopolysaccharide (LPS is a major component of outer-membrane gram-negative bacteria, and it can act as a Pathogen-Associated Molecular Pattern (PAMP for perception of pathogens by plants. LPS can be recognized by plants, triggering certain plant defense-related responses, including callose deposition. This study investigated induction of callose deposition by bacterial LPS in tobacco. Tobacco leaves were infiltrated with 400 μg/mL and 800 μg/mL LPS extracted from Pseudomonas syringae pv. tabaci (Pta and Pseudomonas syringae pv. glycinea (Pgl and incubated for 24 h or 48 h. To detect callose deposition, tobacco leaves were cleared in lactophenol solution, stained with aniline blue, and visualized by fluorescence microscopy. Results showed that LPS from Pgl induced more callose deposition in tobacco leaves than did that from Pta. In addition, a Pearson correlation test revealed that incubation period was the most significant factor in callose deposition, followed by the type of LPS bacteria. However, LPS concentration was not significantly corelated to callose deposition in tobacco leaves.

  17. PCR-DGGE assessment of the bacterial diversity in Spanish-style green table-olive fermentations

    OpenAIRE

    Lucena-Padrós, Helena; Jiménez, Esther; Maldonado-Barragán, Antonio; Rodríguez, Juan M.; Ruiz-Barba, José Luis

    2015-01-01

    © 2015 Elsevier B.V. The bacterial ecology associated to Spanish-style green olive fermentations has been studied, attending to its dynamics along the time and its distribution, by a culture-independent approach based on PCR-DGGE. Forty-three 10-tonne fermenters were selected from the fermentation yards (patios) of two large table-olive manufacturing companies in southern Spain. The fermenting brines of 20 of these fermenters were previously analyzed through culture-dependent methods, allowin...

  18. Potential of bacterial fermentation as a biosafe method of improving ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-05-04

    May 4, 2009 ... Fermented fish silage supplementation in quail diet. Increase in egg production and quality. (Haugh unit). (Zynudheen et al., 2008). Kocuria rosea. Poultry feathers. (fermented feather meal). -. Improved content and availability of amino acids, lysine 3.46%, histidine 0.94%, methionine 0.69%. (Bertsch et al.,.

  19. Bacterial community dynamics and metabolite changes in myeolchi-aekjeot, a Korean traditional fermented fish sauce, during fermentation.

    Science.gov (United States)

    Lee, Se Hee; Jung, Ji Young; Jeon, Che Ok

    2015-06-16

    Myeolchi-aekjeot (MA) is a Korean traditional fish sauce, made by fermenting salted [approximately 25% (w/v)] anchovies. Three sets of MA samples, S-MA, M-MA, and L-MA, were prepared using small (5-8 cm), medium (8-10 cm), and large (10-13 cm) anchovies, respectively, and their bacterial communities and metabolites were investigated for 280 days. Bacterial community analysis using pyrosequencing revealed that, in S-MA, the initially dominant genera, including Phychrobacter, Photobacterium, and Vibrio, disappeared rapidly and Salinivibrio, Staphylococcus, and Tetragenococcus/Halanaerobium appeared sequentially as the major populations. In contrast, in M-MA and L-MA, the initially dominant genera were maintained relatively well during the early fermentation period, but eventually Tetragenococcus became predominant without the growth of Halanaerobium. The changes in the bacterial community occurred more quickly in MA prepared with smaller anchovies than in those prepared with larger anchovies. Metabolite analysis using (1)H NMR showed that amino acids, glycerol, acetate, and lactate rapidly increased in all MA samples during the early fermentation period. Amino acids increased more quickly and then decreased after reaching their maximum level in S-MA, while they increased continually until the end of fermentation in L-MA. This suggests that the complete fermentation of L-MA may require more time than that for S-MA. A correlative analysis between bacterial communities and metabolites revealed that the increase in acetate, butyrate, and putrescine in S-MA was associated with the growth of Halanaerobium, which may be a useful indicator of anchovy sauce quality. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Depolymerization of Pseudomonas stutzeri exopolysaccharide upon fermentation as a promising production process of antibacterial compounds.

    Science.gov (United States)

    Maalej, Hana; Boisset, Claire; Hmidet, Noomen; Colin-Morel, Philippe; Buon, Laurine; Nasri, Moncef

    2017-07-15

    Many researchers have focused on high molecular weight (Mw) exopolysaccharides (EPS) as a source of potentially bioactive lower Mw derivatives. Therefore, it is of interest to find means for efficient and safe production of depolymerized-polymer derivatives. Exopolysaccharide-depolymerization products (EDP) varying in molecular weight were recovered from fermentative depolymerization of a native EPS produced by Pseudomonas stutzeri AS22. Following their purification and physicochemical characterization, the antibacterial activity of EDP on food spoilage and food poisoning microorganisms was evaluated through the measurement of the inhibition zone diameter, the half maximal (IC50) and the minimal (MIC) inhibitory concentrations. Our results indicate that the lower the Mw, the higher will be the effectiveness of EDP on reducing Gram-negative bacteria growth and the opposite trend was observed in the case of Gram-positive bacteria. EDP bioactivities may provide novel insights into the potentiality of P. stutzeri EPS and its derivatives to be used as functional-food components. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Bacterial dynamics during yearlong spontaneous fermentation for production of ngari, a dry fermented fish product of Northeast India.

    Science.gov (United States)

    Devi, Khunjamayum Romapati; Deka, Manab; Jeyaram, Kumaraswamy

    2015-04-16

    Ngari is the most popular traditionally processed non-salted fish product, prepared from sun-dried small cyprinid fish Puntius sophore (Ham.) in Manipur state of Northeast India. The microbial involvement in ngari production remained uncertain due to its low moisture content and yearlong incubation in anaerobically sealed earthen pots without any significant change in total microbial count. The culture-independent PCR-DGGE analysis used during this study confirmed a drastic bacterial community structural change in comparison to its raw material. To understand the bacterial dynamics during this dry fermentation, time series samples collected over a period of nine months through destructive sampling from two indigenous ngari production centres were analysed by using both culture-dependent and culture-independent molecular methods. A total of 210 bacteria isolated from the samples were identified by amplified ribosomal DNA restriction analysis (ARDRA) based grouping and 16S rRNA gene sequence similarity analysis. The dominant bacteria were Staphylococcus cohnii subsp. cohnii (38.0%), Tetragenococcus halophilus subsp. flandriensis (16.8%), a novel phylotype related to Lactobacillus pobuzihii (7.2%), Enterococcus faecium (7.2%), Bacillus indicus (6.3%) and Staphylococcus carnosus (3.8%). Distinct bacterial dynamics with the emergence of T. halophilus at third month (10(6)CFU/g), L. pobuzihii at sixth month (10(6)CFU/g), S. carnosus at three to six months (10(4)CFU/g) and B. indicus at six to nine months (10(5)CFU/g) in both the production centres was observed during ngari fermentation. However, the other two dominant bacteria S. cohnii and E. faecium were isolated throughout the fermentation with the population of 10(6)CFU/g and 10(4)CFU/g respectively. Culture-independent PCR-DGGE analysis further showed the presence of additional species, in which Kocuria halotolerans and Macrococcus caseolyticus disappeared during fermentation while Clostridium irregulare and

  2. Effect of fermented soy milk on the intestinal bacterial ecosystem.

    Science.gov (United States)

    Cheng, I-Chi; Shang, Huey-Fang; Lin, Tzann-Feng; Wang, Tseng-Hsing; Lin, Hao-Sheng; Lin, Shyh-Hsiang

    2005-02-28

    To investigate the effect of fermented soy milk on human ecosystem in the intestinal tract by way of examining the population of different microorganisms isolated from fecal samples. A crossover experimental design was applied. Twenty-eight healthy adults completed this experiment. Each subject consumed 250 mL, twice a day between meals, of either fermented soy milk or regular soy milk first for 2 wk, then switched to the other drink after 2 wk. Fecal samples were collected from all subjects every week starting from the second week to the end of the experiment. The microorganisms analyzed were Bifidobacterium spp., Lactobacillus spp., Clostridium perfringens, coliform organisms, and total anaerobic organisms. In the period of fermented soy milk consumption, the populations of Bifidobacterium spp. and Lactobacillus spp. increased (Psoy milk consumption. Intake of fermented soy milk significantly improved the ecosystem of the intestinal tract in the body by increasing the amount of probiotics.

  3. Bacterial Diversity Analysis during the Fermentation Processing of Traditional Chinese Yellow Rice Wine Revealed by 16S rDNA 454 Pyrosequencing.

    Science.gov (United States)

    Fang, Ruo-si; Dong, Ya-chen; Chen, Feng; Chen, Qi-he

    2015-10-01

    Rice wine is a traditional Chinese fermented alcohol drink. Spontaneous fermentation with the use of the Chinese starter and wheat Qu lead to the growth of various microorganisms during the complete brewing process. It's of great importance to fully understand the composition of bacteria diversity in rice wine in order to improve the quality and solve safety problems. In this study, a more comprehensive bacterial description was shown with the use of bacteria diversity analysis, which enabled us to have a better understanding. Rarefaction, rank abundance, alpha Diversity, beta diversity and principal coordinates analysis simplified their complex bacteria components and provide us theoretical foundation for further investigation. It has been found bacteria diversity is more abundant at mid-term and later stage of brewing process. Bacteria community analysis reveals there is a potential safety hazard existing in the fermentation, since most of the sequence reads are assigned to Enterobacter (7900 at most) and Pantoea (7336 at most), followed by Staphylococcus (2796 at most) and Pseudomonas (1681 at most). Lactic acid bacteria are rare throughout the fermentation process which is not in accordance with other reports. This work may offer us an opportunity to investigate micro ecological fermentation system in food industry. © 2015 Institute of Food Technologists®

  4. In vitro bacterial fermentation of tropical fruit fibres.

    Science.gov (United States)

    Vong, M H; Stewart, M L

    2013-09-01

    Tropical fruits such as mango, papaya, pineapple and banana are rich sources of dietary fibre. However, few studies have examined the potential physiological effects of fibre from these tropical fruits. The aim of this study was to characterise the fermentability of dietary fibre found in banana, papaya, pineapple and mango as an estimate of the physiological effects of consuming these fruits. Freeze-dried fruit was subjected to in vitro digestion to remove digestible carbohydrates. Digestion residues were freeze-dried prior to fermentation. In vitro fermentation was carried for 24 h under anaerobic conditions to simulate conditions in the large intestine. Gas volume, pH and short chain fatty acids (SCFAs) concentration were measured at 0, 4, 8, 12, and 24 h. SCFAs were analysed by gas chromatography. There was no gas production from 0 to 8 h time points for all samples. Mango fibre resulted in more gas at 12 and 24 h than pineapple, papaya and banana fibres. The slurry pH was significantly lower for mango fibre at 12 and 24 h compared to other samples. Mango fibre resulted in significantly more propionate at 8 h compared to papaya and pineapple fibres. Butyrate concentrations were only significantly different at 4 h. At 24 h total and individual SCFA production did not differ among samples. All fruit fibres were fermentable, with mango fibre being the most rapidly fermented. Additional work is necessary to confirm a benefit on digestive health.

  5. Dynamic laser speckle to detect motile bacterial response of Pseudomonas aeruginosa

    Energy Technology Data Exchange (ETDEWEB)

    Sendra, H [Laboratorio de Laser. Facultad de Ingenieria. Universidad Nacional de Mar del Plata, Juan B. Justo 4302. (7600) Mar del Plata (Argentina); Murialdo, S [Grupo de Ingenieria BioquImica. Departamento de Quimica. Facultad de Ingenieria. Universidad Nacional de Mar del Plata, Juan B. Justo 4302. (7600) Mar del Plata (Argentina); Passoni, L [Laboratorio de BioingenierIa. Facultad de Ingenieria. Universidad Nacional de Mar del Plata, Juan B. Justo 4302. (7600) Mar del Plata (Argentina)

    2007-11-15

    This proposal deals with the technique for detection of motile response of Pseudomonas aeruginosa using dynamic laser speckle or biospeckle as an alternative method. The study of bacterial displacement plays an essential role in biocatalysts processes and biodegradation. Hence, some biodegrading enzymes are benign catalytic that could be used for the production of industrially useful compounds as well as in wastewater treatments. This work presents an experimental set up and a computational process using frame sequences of dynamic laser speckle as a novel application. The objective was the detection of different levels of motility in bacteria. The encouraging results were achieved through a direct and non invasive observation method of the phenomenon.

  6. Insights into the bacterial community and its temporal succession during the fermentation of wine grapes

    Directory of Open Access Journals (Sweden)

    Hailan ePiao

    2015-08-01

    Full Text Available Grapes harbor complex microbial communities. It is well known that yeasts, typically Saccharomyces cerevisiae, and bacteria, commonly the lactic acid fermenting Oenococcus oeni, work sequentially during primary and secondary wine fermentation. In addition to these main players, several microbes, often with undesirable effects on wine quality, have been found in grapes and during wine fermentation. However, still little is known about the dynamics of the microbial community during the fermentation process. In previous studies culture dependent methods were applied to detect and identify microbial organisms associated with grapes and grape products, which resulted in a picture that neglected the non-culturable fraction of the microbes. To obtain a more complete picture of how microbial communities change during grape fermentation and how different fermentation techniques might affect the microbial community composition, we employed next-generation sequencing (NGS. A better understanding of the microbial dynamics and their effect on the final product is of great importance to help winemakers produce wine styles of consistent and high quality. In this study, we focused on the bacterial community dynamics during wine vinification by amplifying and sequencing the hypervariable V1–V3 region of the 16S rRNA gene – a phylogenetic marker gene that is ubiquitous within prokaryotes. Bacterial communities and their temporal succession was observed for communities associated with organically and conventionally produced wines. In addition, we analyzed the chemical characteristics of the grape musts during the organic and conventional fermentation process. These analyses revealed distinct bacterial population with specific temporal changes as well as different chemical profiles for the organically and conventionally produced wines. In summary these results suggest a possible correlation between the temporal succession of the bacterial population and the

  7. Insights into the bacterial community and its temporal succession during the fermentation of wine grapes

    Science.gov (United States)

    Piao, Hailan; Hawley, Erik; Kopf, Scott; DeScenzo, Richard; Sealock, Steven; Henick-Kling, Thomas; Hess, Matthias

    2015-01-01

    Grapes harbor complex microbial communities. It is well known that yeasts, typically Saccharomyces cerevisiae, and bacteria, commonly the lactic acid fermenting Oenococcus oeni, work sequentially during primary and secondary wine fermentation. In addition to these main players, several microbes, often with undesirable effects on wine quality, have been found in grapes and during wine fermentation. However, still little is known about the dynamics of the microbial community during the fermentation process. In previous studies culture dependent methods were applied to detect and identify microbial organisms associated with grapes and grape products, which resulted in a picture that neglected the non-culturable fraction of the microbes. To obtain a more complete picture of how microbial communities change during grape fermentation and how different fermentation techniques might affect the microbial community composition, we employed next-generation sequencing (NGS)—a culture-independent method. A better understanding of the microbial dynamics and their effect on the final product is of great importance to help winemakers produce wine styles of consistent and high quality. In this study, we focused on the bacterial community dynamics during wine vinification by amplifying and sequencing the hypervariable V1–V3 region of the 16S rRNA gene—a phylogenetic marker gene that is ubiquitous within prokaryotes. Bacterial communities and their temporal succession was observed for communities associated with organically and conventionally produced wines. In addition, we analyzed the chemical characteristics of the grape musts during the organic and conventional fermentation process. These analyses revealed distinct bacterial population with specific temporal changes as well as different chemical profiles for the organically and conventionally produced wines. In summary these results suggest a possible correlation between the temporal succession of the bacterial population

  8. Cow Dung Substrate for the Potential Production of Alkaline Proteases by Pseudomonas putida Strain AT in Solid-State Fermentation

    Directory of Open Access Journals (Sweden)

    Ponnuswamy Vijayaraghavan

    2014-01-01

    Full Text Available Cow dung and agroresidues were used as the substrates for the production of alkaline proteases by Pseudomonas putida strain AT in solid-state fermentation. Among the various substrates evaluated, cow dung supported maximum (1351±217 U/g protease production. The optimum conditions for the production of alkaline proteases were a fermentation period of 48 h, 120% (v/w moisture, pH 9, and the addition of 6% (v/w inoculum, 1.5% (w/w trehalose, and 2.0% (w/w yeast extract to the cow dung substrate. The enzyme was active over a range of temperatures (50–70°C and pHs (8–10, with maximum activity at 60°C and pH 9. These enzymes showed stability towards surfactants, detergents, and solvent and digested various natural proteins.

  9. Effects of bacterial inoculants and an enzyme on the fermentation ...

    African Journals Online (AJOL)

    The jars were opened on days 3, 7 and 15 to determine pH, while those of day 25 were sampled to determine nutrient composition, fermentation characteristics and aerobic stability. Inoculation reduced pH, butyric acid and ammonia-N and increased lactic acid content in sweet sorghum silage compared with the control.

  10. Amylase production under solid state fermentation by a bacterial ...

    African Journals Online (AJOL)

    This study was concerned with the screening of a suitable isolate and optimization of cultural conditions for the biosynthesis of thermostable amylase under solid state fermentation (SSF). Twenty seven isolates were screened for amylase production out of which one isolate designated as W74 showed maximal amylase ...

  11. Structure-to-function relationships of bacterial translocator protein (TSPO: a focus on Pseudomonas

    Directory of Open Access Journals (Sweden)

    Charlène eLeneveu-Jenvrin

    2014-11-01

    Full Text Available The translocator protein (TSPO, which was previously designated as the peripheral-type benzodiazepine receptor, is a 3.5 billion year-old evolutionarily conserved protein expressed by most Eukarya, Archae and Bacteria, but its organization and functions differ remarkably. By taking advantage of the genomic data available on TSPO, we focused on bacterial TSPO and attempted to define functions of TSPO in Pseudomonas via in silico approaches. A tspo ortholog has been identified in several fluorescent Pseudomonas. This protein presents putative binding motifs for cholesterol and PK 11195, which is a specific drug ligand of mitochondrial TSPO. While it is a common surface distribution, the sense of insertion and membrane localization differ between α- and γ-proteobacteria. Experimental published data and STRING analysis of common TSPO partners in fluorescent Pseudomonas indicate a potential role of TSPO in the oxidative stress response, iron homeostasis and virulence expression. In these bacteria, TSPO could also take part in signal transduction and in the preservation of membrane integrity.

  12. Antibiofilm and anti-infection of a marine bacterial exopolysaccharide against Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Shimei eWu

    2016-02-01

    Full Text Available Pseudomonas aeruginosa is a well-known pathogenic bacterium that forms biofilms and produces virulence factors, thus leading to major problems in many fields, such as clinical infection, food contamination and marine biofouling. In this study, we report the purification and characterization of an exopolysaccharide EPS273 from the culture supernatant of marine bacterium Pseudomonas stutzeri 273. The exopolysaccharide EPS273 not only effectively inhibits biofilm formation but also disperses preformed biofilm of Pseudomonas aeruginosa PAO1. High performance liquid chromatography traces of the hydrolyzed polysaccharides shows that EPS273 primarily consists of glucosamine, rhamnose, glucose and mannose. Further investigation demonstrates that EPS273 reduces the production of the virulence factors pyocyanin, exoprotease and rhamnolipid, and the virulence of P. aeruginosa PAO1 to human lung cells A549 and zebrafish embryos is also obviously attenuated by EPS273. In addition, EPS273 also greatly reduces the production of hydrogen peroxide (H2O2 and extracellular DNA (eDNA, which are important factors for biofilm formation. Furthermore, EPS273 exhibits strong antioxidant potential by quenching hydroxyl and superoxide anion radicals. Notably, the antibiofouling activity of EPS273 is observed in the marine environment up to two weeks according to the amounts of bacteria and diatoms in the glass slides submerged in the ocean. Taken together, the properties of EPS273 indicate that it has a promising prospect in combating bacterial biofilm-associated infection, food-processing contamination and marine biofouling.

  13. Large-scale targeted metagenomics analysis of bacterial ecological changes in 88 kimchi samples during fermentation.

    Science.gov (United States)

    Lee, Moeun; Song, Jung Hee; Jung, Min Young; Lee, Se Hee; Chang, Ji Yoon

    2017-09-01

    The microbial communities in kimchi vary widely, but the precise effects of differences in region of origin, ingredients, and preparation method on the microbiota are unclear. We analyzed the bacterial community composition of household (n = 69) and commercial (n = 19) kimchi samples obtained from six Korean provinces between April and August 2015. Samples were analyzed by barcoded pyrosequencing targeting the V1-V3 region of the 16S ribosomal RNA gene. The initial pH of the kimchi samples was 5.00-6.39, and the salt concentration was 1.72-4.42%. Except for sampling locality, all categorical variables, i.e., salt concentration, major ingredient, fermentation period, sampling time, and manufacturing process, influenced the bacterial community composition. Particularly, samples were highly clustered by sampling time and salt concentration in non-metric multidimensional scaling plots and an analysis of similarity. These results indicated that the microbial community differed according to fermentation conditions such as salt concentration, major ingredient, fermentation period, and sampling time. Furthermore, fermentation properties, including pH, acidity, salt concentration, and microbial abundance differed between kimchi samples from household and commercial sources. Analyses of changes in bacterial ecology during fermentation will improve our understanding of the biological properties of kimchi, as well as the relationships between these properties and the microbiota of kimchi. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Effects of Different Salt Treatments on the Fermentation Metabolites and Bacterial Profiles of Kimchi.

    Science.gov (United States)

    Kim, Dong Wook; Kim, Bo-Min; Lee, Hyeon-Jeong; Jang, Gwang-Ju; Song, Seong Hwa; Lee, Jae-In; Lee, Sang Bong; Shim, Jae Min; Lee, Kang Wook; Kim, Jeong Hwan; Ham, Kyung-Sik; Chen, Feng; Kim, Hyun-Jin

    2017-05-01

    The effects of purified salt (PS) and mineral-rich sea salt (MRS), both with different mineral profiles, on kimchi fermentation were studied using a culture-dependent 16S rRNA sequencing technique and mass-based metabolomic analysis. The different mineral profiles in the fermentation medium caused changes in the bacterial profiles of the 2 kimchi products. An increase of Leuconostoc species in MRS-kimchi decreased the Lactobacillus/Leuconostoc ratio, which led to changes in metabolites (including sugars, amino acids, organic acids, lipids, sulfur compounds, and terpenoids) associated with kimchi quality. Although further studies on the relationship between these salt types and kimchi fermentation are needed, these results suggested that the MRS treatment had positively affected the changes of the kimchi mineral contents, bacterial growth, and metabolite profiles, which are linked to kimchi quality. © 2017 Institute of Food Technologists®.

  15. Characterisation of the gastrointestinal bacterial community in pigs fed fermented liquid feed and dry feed

    DEFF Research Database (Denmark)

    Højberg, Ole; Knudsen, B.; Canibe, N.

    2001-01-01

    Feeding pigs with fermented liquid feed (FLF) has been shown to reduce the number of enteropathogens such as Salmonella and Brachyospira hyodysenteriae as well as coliform bacteria in general in the gastrointestinal tract (GIT). Also the commensal bacterial populations have been shown to respond...

  16. Effects of wilting and molasses addition on fermentation and bacterial community in guinea grass silage.

    Science.gov (United States)

    Nishino, N; Li, Y; Wang, C; Parvin, S

    2012-03-01

    Acetic acid is considered an important preservative in tropical grass ensiling. The objective of the current experiments was to follow the ensiling fermentation of low dry matter (DM) tropical grass as a model to study changes in bacterial communities during acetic acid fermentation. Direct-cut and wilted guinea grass silage was prepared with and without molasses. A high acetic acid level was observed during the fermentation of direct-cut silage, and long storage increased the butyric acid and ethanol content if molasses was not added. The lactic acid production in wilted silage was greater than the acetic acid production, but prolonged ensiling decreased the lactic to acetic acid ratio regardless of molasses addition. Adding molasses enhanced the lactic acid content in both direct-cut and wilted silage. The bacterial community, identified by denaturing gradient gel electrophoresis, was affected by wilting and molasses addition. Bands for Pantoea sp. and Morganella sp. became faint when acetic acid fermentation was suppressed, and those for Pediococcus pentosaceus and Lactococcus garvieae were detected when lactic acid fermentation was enhanced by wilting and molasses addition. Lactobacillus plantarum and Lactococcus lactis were found throughout the ensiling process in all silage types. Distinct changes occurred in the bacterial community in guinea grass silage because of wilting and molasses addition. These changes could explain how lactic acid fermentation was enhanced but could not help determine which bacteria were associated with enhanced acetic acid fermentation. The study reveals the effects of wilting and molasses during ensiling of low DM tropical grasses and the associated bacteria. © 2011 The Authors. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.

  17. Bacterial community analysis during fermentation of ten representative kinds of kimchi with barcoded pyrosequencing.

    Science.gov (United States)

    Park, Eun-Jin; Chun, Jongsik; Cha, Chang-Jun; Park, Wan-Soo; Jeon, Che Ok; Bae, Jin-Woo

    2012-05-01

    Kimchi, a food made of fermented vegetables, is densely populated by indigenous microorganisms that originate from the raw ingredients under normal conditions. Most microbiological studies on kimchi have been on the most popular dish, baechu-kimchi (Chinese cabbage kimchi). Therefore, relatively little is known about the various other kinds of kimchi (depending on the region, season, main ingredient, starter culture inoculation and recipe). In this study, we collected 100 samples periodically during the fermentation of ten representative kinds of kimchi (including starter-inoculated kimchi) that were stored in the refrigerator (4 °C) during the 30-35 days fermentation period. The multiplex barcoded pyrosequencing of a hypervariable V1-V3 region of the 16S ribosomal RNA (rRNA) gene tagged with sample-specific barcodes for multiplex identifiers was employed for bacterial community profiling. We found that bacterial communities differed between starter-inoculated and non-inoculated kimchi at the early stages of fermentation, but overall there were no significant differences in the late phases. Also, the diversity and richness of bacterial communities varied depending on the various types of kimchi, and these differences could largely be explained by the major ingredients and the manufacture processes of each types of kimchi. This study provides the comprehensive understanding of the factors influencing the biodiversity of the kimchi ecosystem. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Effects of bacterial inoculants and an enzyme on the fermentation ...

    African Journals Online (AJOL)

    jannes

    where 500 g of sample from each jar was loosely packed in an open plastic jar that was covered with two layers of .... (2009), who reported a lack of effect on pH with bacterial inoculation to sweet sorghum straw at ... in sweet sorghum straws, which can easily produce a rapid drop in silage pH without the use of additives.

  19. (FOS)-fermenting yeast or bacterial strains as potential

    African Journals Online (AJOL)

    ltrujillo

    or solid growth medium containing these “prebiotic” ... Saccharomyces cerevisiae L/25-7-82, S. cerevisiae L/25-7-76, ... Culture media. The commonly used minimal Yeast Nitrogen base (YNB) and rich media YP (Yeast extract and Peptone) and LB (Luria Bertani) for yeast and bacterial grow, respectively, were prepared ...

  20. Pseudomonas aeruginosa serA Gene Is Required for Bacterial Translocation through Caco-2 Cell Monolayers.

    Science.gov (United States)

    Yasuda, Masashi; Nagata, Syouya; Yamane, Satoshi; Kunikata, Chinami; Kida, Yutaka; Kuwano, Koichi; Suezawa, Chigusa; Okuda, Jun

    2017-01-01

    To specify critical factors responsible for Pseudomonas aeruginosa penetration through the Caco-2 cell epithelial barrier, we analyzed transposon insertion mutants that demonstrated a dramatic reduction in penetration activity relative to P. aeruginosa PAO1 strain. From these strains, mutations could be grouped into five classes, specifically flagellin-associated genes, pili-associated genes, heat-shock protein genes, genes related to the glycolytic pathway, and biosynthesis-related genes. Of these mutants, we here focused on the serA mutant, as the association between this gene and penetration activity is yet unknown. Inactivation of the serA gene caused significant repression of bacterial penetration through Caco-2 cell monolayers with decreased swimming and swarming motilities, bacterial adherence, and fly mortality rate, as well as repression of ExoS secretion; however, twitching motility was not affected. Furthermore, L-serine, which is known to inhibit the D-3-phosphoglycerate dehydrogenase activity of the SerA protein, caused significant reductions in penetration through Caco-2 cell monolayers, swarming and swimming motilities, bacterial adherence to Caco-2 cells, and virulence in flies in the wild-type P. aeruginosa PAO1 strain. Together, these results suggest that serA is associated with bacterial motility and adherence, which are mediated by flagella that play a key role in the penetration of P. aeruginosa through Caco-2 cell monolayers. Oral administration of L-serine to compromised hosts might have the potential to interfere with bacterial translocation and prevent septicemia caused by P. aeruginosa through inhibition of serA function.

  1. Crystal structure of Pseudomonas aeruginosa lipase in the open conformation - The prototype for family I.1 of bacterial lipases

    NARCIS (Netherlands)

    Nardini, M; Lang, DA; Liebeton, K; Jaeger, KE; Dijkstra, BM

    2000-01-01

    The x-ray structure of the lipase from Pseudomonas aeruginosa PAO1 has been determined at 2.54 Angstrom resolution. It is the first structure of a member of homology family I.1 of bacterial lipases. The structure shows a variant of the alpha/beta hydrolase fold, with Ser(82), Asp(229), and His(251)

  2. Resistant and susceptible responses in alfalfa (Medicago sativa) to bacterial stem blight caused by Pseudomonas syringae pv. syringae

    Science.gov (United States)

    Bacterial stem blight caused by Pseudomonas syringae pv. syringae is a common disease of alfalfa (Medicago sativa L.) in the central and western U.S. and has been reported in Australia and Europe. The disease is not always recognized because symptoms are often associated with frost damage. Two culti...

  3. Bacterial canker of plum caused by Pseudomonas syringae pathovars, as a serious threat for plum production in the Netherlands

    NARCIS (Netherlands)

    Wenneker, M.; Janse, J.D.; Bruine, de A.; Vink, P.; Pham, K.T.K.

    2012-01-01

    In the Netherlands, bacterial canker of plum trees (Prunus domestica) caused by Pseudomonas syringae pathovars syringae and morsprunorum is a recent and serious problem. The trunks of the affected plum trees are girdled by cankers resulting in relatively sudden death of the trees 1 to 4 years after

  4. Pseudomonas aeruginosa Enolase Influences Bacterial Tolerance to Oxidative Stresses and Virulence.

    Science.gov (United States)

    Weng, Yuding; Chen, Fei; Liu, Yiwei; Zhao, Qiang; Chen, Ronghao; Pan, Xiaolei; Liu, Chang; Cheng, Zhihui; Jin, Shouguang; Jin, Yongxin; Wu, Weihui

    2016-01-01

    Pseudomonas aeruginosa is a Gram negative opportunistic pathogenic bacterium, which causes acute and chronic infections. Upon entering the host, bacteria alter global gene expression to adapt to host environment and avoid clearance by the host. Enolase is a glycolytic enzyme involved in carbon metabolism. It is also a component of RNA degradosome, which is involved in RNA processing and gene regulation. Here, we report that enolase is required for the virulence of P. aeruginosa in a murine acute pneumonia model. Mutation of enolase coding gene (eno) increased bacterial susceptibility to neutrophil mediated killing, which is due to reduced tolerance to oxidative stress. Catalases and alkyl hydroperoxide reductases play a major role in protecting the cell from oxidative damages. In the eno mutant, the expression levels of catalases (KatA and KatB) were similar as those in the wild type strain in the presence of H2O2, however, the expression levels of alkyl hydroperoxide reductases (AhpB and AhpC) were significantly reduced. Overexpression of ahpB but not ahpC in the eno mutant fully restored the bacterial resistance to H2O2 as well as neutrophil mediated killing, and partially restored bacterial virulence in the murine acute pneumonia model. Therefore, we have identified a novel role of enolase in the virulence of P. aeruginosa.

  5. Biodegradation of hexavalent chromium (Cr+6) in wastewater using Pseudomonas sp. and Bacillus sp. bacterial strains

    Energy Technology Data Exchange (ETDEWEB)

    Qasim, Muhammad [Department of Chemical Engineering, American University of Sharjah (United Arab Emirates)

    2013-07-01

    The recovery of toxic metal compounds is a deep concern in all industries. Hexavalent chromium is particularly worrying because of its toxic influence on human health. In this paper, biodegradation of hexavalent chromium (Cr+6) present in wastewater has been studied using two different bacterial strains; Pseudomonas sp. and Bacillus sp. A chemostat (with and without recycle of cells) with 10 L liquid culture volume was used to study the substrate and the biomass cell concentrations with time. Also, the degree of substrate conversion was studied by the varying the dilution rate as an independent parameter. The dilution rate (ratio of feed flow rate to the culture volume) was varied by varying the feed volumetric rate from 110-170 mL/h for inlet hexavalent chromium concentrations of 70 mg/dm3. The results show that a chemostat with recycle gives a better performance in terms of substrate conversion than a chemostat without a recycle. Moreover, the degree of substrate conversion decreases as the dilution rate is increased. Also, Bacillus sp. was found to give higher conversions compared to pseudomonas sp.

  6. Cultivation-independent comprehensive investigations on bacterial communities in serofluid dish, a traditional Chinese fermented food

    Directory of Open Access Journals (Sweden)

    Peng Chen

    2016-03-01

    Full Text Available Serofluid dish (or Jiangshui, in Chinese, a traditional food in the Chinese culture, is made from vegetables by fermentation. In this study, bacterial community of the fermented serofluid dish was assessed by Illumina amplicon sequencing. The metagenome comprised of 49,589 average raw reads with an average 11,497,917 bp and G+C content is 52.46%. This is the first report on V4 hyper-variable region of the 16S rRNA metagenome sequence employing Illumina platform to profile the microbial community of this little known fermented food from Gansu Province, China. The metagenome sequence can be accessed at NCBI, SRA database accession no. SRP065370.

  7. Cultivable anaerobic and aerobic bacterial communities in the fermentation chambers of Holotrichia parallela (coleoptera: scarabaeidae) larvae.

    Science.gov (United States)

    Zhang, Zhen-Yu; Yuan, Yimin; Ali, Muhammad Waqar; Peng, Tao; Peng, Wei; Raza, Muhammad Fahim; Zhao, Yongshun; Zhang, Hongyu

    2018-01-01

    As important pests, scarab beetle larvae survive on plant biomass and the microbiota of the fermentation chamber play an important role in the digestion of lignocellulose-rich diets. However, the cultivable microbes, especially the anaerobic cultivable microbes, are still largely unknown. Here, both cultivable anaerobic and aerobic bacterial communities associated with the fermentation chamber of Holotrichia parallela larvae were investigated. In total bacteria cells directly enumerated by the 4', 6-diamidino-2-phenylindole (DAPI) staining method, the viable plate counts of cultivable bacteria in the fermentation chamber accounted for 0.92% of proportion. These cultivable bacteria were prone to attach to the fermentation chamber wall (88.41%) compared to the chamber contents. Anaerobic bacteria were dominant in the cultivable bacteria attaching to the fermentation chamber wall (70.20%), while the quantities of anaerobes and aerobes were similar in the chamber contents. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), fingerprinting and sequence analysis of isolated colonies revealed that the cultivable bacteria are affiliated with class γ-Proteobacteria, Bacteroidia, Actinobacteria, Clostridia and β-Proteobacteria. γ-Proteobacteria was the major type of anaerobic cultivable bacteria and even the only one type of aerobic cultivable bacteria. Taken together, our results suggest, for the first time, that anaerobic microbiota are dominant in cultivable bacteria in the special anoxia niche of the fermentation chamber from H. parallela larvae. These bacterial isolates could be a treasure trove for screening lignocellulytic microbes which are essential for the plant biomass digestion of this scarab species.

  8. Ice nucleators, bacterial cells and Pseudomonas syringae in precipitation at Jungfraujoch

    Science.gov (United States)

    Stopelli, Emiliano; Conen, Franz; Guilbaud, Caroline; Zopfi, Jakob; Alewell, Christine; Morris, Cindy E.

    2017-03-01

    Ice nucleation is a means by which the deposition of an airborne microorganism can be accelerated under favourable meteorological conditions. Analysis of 56 snow samples collected at the high-altitude observatory Jungfraujoch (3580 m a.s.l.) revealed an order-of-magnitude-larger dynamic range of ice-nucleating particles active at -8 °C (INPs-8) compared to the total number of bacterial cells (of which on average 60 % was alive). This indicates a shorter atmospheric residence time for INPs-8. Furthermore, concentrations of INPs-8 decreased much faster, with an increasing fraction of water precipitated from the air mass prior to sampling, than the number of total bacterial cells. Nevertheless, at high wind speeds (> 50 km h-1) the ratio of INPs-8 to total bacterial cells largely remained in a range between 10-2 and 10-3, independent of prior precipitation, likely because of recent injections of particles in regions upwind. Based on our field observations, we conclude that ice nucleators travel shorter legs of distance with the atmospheric water cycle than the majority of bacterial cells. A prominent ice-nucleating bacterium, Pseudomonas syringae, has been previously supposed to benefit from this behaviour as a means to spread via the atmosphere and to colonise new host plants. Therefore, we targeted this bacterium with a selective cultivation approach. P. syringae was successfully isolated for the first time at such an altitude in 3 of 13 samples analysed. Colony-forming units of this species constituted a minor fraction (10-4) of the numbers of INPs-8 in these samples. Overall, our findings expand the geographic range of habitats where this bacterium has been found and corroborate theories on its robustness in the atmosphere and its propensity to spread to colonise new habitats.

  9. PCR-DGGE assessment of the bacterial diversity in Spanish-style green table-olive fermentations.

    Science.gov (United States)

    Lucena-Padrós, Helena; Jiménez, Esther; Maldonado-Barragán, Antonio; Rodríguez, Juan M; Ruiz-Barba, José Luis

    2015-07-16

    The bacterial ecology associated to Spanish-style green olive fermentations has been studied, attending to its dynamics along the time and its distribution, by a culture-independent approach based on PCR-DGGE. Forty-three 10-tonne fermenters were selected from the fermentation yards (patios) of two large table-olive manufacturing companies in southern Spain. The fermenting brines of 20 of these fermenters were previously analyzed through culture-dependent methods, allowing comparisons of both methodologies. A statistical analysis of DGGE banding profiles obtained using bacteria universal primers demonstrated significant evidences of discrimination of bacterial communities by location (patio) and fermentation stage. Specific microbial "fingerprints" could be established for these variables. At least 17 bacterial species were detected, most of them previously isolated from the same fermenters. Most of these species belonged to the lactic acid bacteria (LAB) group. Dominance of species within the Lactobacillus plantarum group was confirmed. Marinilactibacillus sp. and Propionibacterium olivae, which were not isolated in the previous culture-dependent study, were detected. Alkalibacterium sp. and Halolactibacillus sp. were detected for the first time in table olive fermentations. Using Lactobacillus-group specific primers, significant clustering within the DGGE banding profiles was observed, allowing discrimination regarding the actual fermentation stage. These results corroborated the previous culture-dependent study, and added the detection of Alkalibacterium sp. and Pediococcus acidilactici. The species Alkalibacterium sp., Marinilactibacillus sp. and Halolactibacillus sp. are characterized by their ability to carry out lactic acid fermentation under alkaline conditions and thus ascribed within the halophilic and alkaliphilic lactic acid bacteria (HALAB). Their ubiquitous presence suggests that they could play an important role in Spanish-style olive fermentations

  10. Pseudomonas granadensis sp. nov., a new bacterial species isolated from the Tejeda, Almijara and Alhama Natural Park, Granada, Spain.

    Science.gov (United States)

    Pascual, Javier; García-López, Marina; Bills, Gerald F; Genilloud, Olga

    2015-02-01

    During the course of screening bacterial isolates as sources of as-yet unknown bioactive compounds with pharmaceutical applications, a chemo-organotrophic, Gram-negative bacterium was isolated from a soil sample taken from the Tejeda, Almijara and Alhama Natural Park, Granada, Spain. Strain F-278,770(T) was oxidase- and catalase-positive, aerobic, with a respiratory type of metabolism with oxygen as the terminal electron acceptor, non-spore-forming and motile by one polar flagellum, although some cells had two polar flagella. Phylogenetic analysis of the 16S rRNA, gyrB, rpoB and rpoD genes revealed that strain F-278,770(T) belongs to the Pseudomonas koreensis subgroup (Pseudomonas fluorescens lineage), with Pseudomonas moraviensis, P. koreensis, P. baetica and P. helmanticensis as its closest relatives. Chemotaxonomic traits such as polar lipid and fatty acid compositions and G+C content of genomic DNA corroborated the placement of strain F-278,770(T) in the genus Pseudomonas. DNA-DNA hybridization assays and phenotypic traits confirmed that this strain represents a novel species of the genus Pseudomonas, for which the name Pseudomonas granadensis sp. nov. is proposed. The type strain is F-278,770(T) ( = DSM 28040(T) = LMG 27940(T)). © 2015 Fundacion MEDINA, Centro de Excelencia en Investigacion de Medicamentos Innovadores en Andalucia.

  11. Bacterial dynamics and metabolite changes in solid-state acetic acid fermentation of Shanxi aged vinegar.

    Science.gov (United States)

    Li, Sha; Li, Pan; Liu, Xiong; Luo, Lixin; Lin, Weifeng

    2016-05-01

    Solid-state acetic acid fermentation (AAF), a natural or semi-controlled fermentation process driven by reproducible microbial communities, is an important technique to produce traditional Chinese cereal vinegars. Highly complex microbial communities and metabolites are involved in traditional Chinese solid-state AAF, but the association between microbiota and metabolites during this process are still poorly understood. In this study, we performed amplicon 16S rRNA gene sequencing on the Illumina MiSeq platform, PCR-denaturing gradient gel electrophoresis, and metabolite analysis to trace the bacterial dynamics and metabolite changes under AAF process. A succession of bacterial assemblages was observed during the AAF process. Lactobacillales dominated all the stages. However, Acetobacter species in Rhodospirillales were considerably accelerated during AAF until the end of fermentation. Quantitative PCR results indicated that the biomass of total bacteria showed a "system microbe self-domestication" process in the first 3 days, and then peaked at the seventh day before gradually decreasing until the end of AAF. Moreover, a total of 88 metabolites, including 8 organic acids, 16 free amino acids, and 66 aroma compounds were detected during AAF. Principal component analysis and cluster analyses revealed the high correlation between the dynamics of bacterial community and metabolites.

  12. Dark fermentative biohydrogen production by mesophilic bacterial consortia isolated from riverbed sediments

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Sneha; Sudhakaran, Anu K.; Sarma, Priyangshu Manab; Subudhi, Sanjukta; Mandal, Ajoy Kumar; Lal, Banwari [Environmental and Industrial Biotechnology Division, The Energy and Resources Institute (TERI), Habitat Place, Darbari Seth Block, Lodhi Road, New Delhi 110003 (India); Gandham, Ganesh [Hindustan Petroleum Corporation Limited, Mumbai Refinery, B. D. Patil Marg, Mahul, Mumbai 400074 (India)

    2010-10-15

    Dark fermentative bacterial strains were isolated from riverbed sediments and investigated for hydrogen production. A series of batch experiments were conducted to study the effect of pH, substrate concentration and temperature on hydrogen production from a selected bacterial consortium, TERI BH05. Batch experiments for fermentative conversion of sucrose, starch, glucose, fructose, and xylose indicated that TERI BH05 effectively utilized all the five sugars to produce fermentative hydrogen. Glucose was the most preferred carbon source indicating highest hydrogen yields of 22.3 mmol/L. Acetic and butyric acid were the major soluble metabolites detected. Investigation on optimization of pH, temperature, and substrate concentration revealed that TERI BH05 produced maximum hydrogen at 37 C, pH 6 with 8 g/L of glucose supplementation and maximum yield of hydrogen production observed was 2.0-2.3 mol H{sub 2}/mol glucose. Characterization of TERI BH05 revealed the presence of two different bacterial strains showing maximum homology to Clostridium butyricum and Clostridium bifermentans. (author)

  13. Influence of trace elements mixture on bacterial diversity and fermentation characteristics of liquid diet fermented with probiotics under air-tight condition.

    Directory of Open Access Journals (Sweden)

    Yuyong He

    Full Text Available Cu2+, Zn2+, Fe2+ and I- are often supplemented to the diet of suckling and early weaning piglets, but little information is available regarding the effects of different Cu2+, Zn2+, Fe2+ and I- mixtures on bacteria growth, diversity and fermentation characteristics of fermented liquid diet for piglets. Pyrosequencing was performed to investigate the effect of Cu2+, Zn2+, Fe2+ and I- mixtures on the diversity, growth and fermentation characteristics of bacteria in the liquid diet fermented with Bacillus subtilis and Enterococcus faecalis under air-tight condition. Results showed that the mixtures of Cu2+, Zn2+, Fe2+ and I- at different concentrations promoted Bacillus growth, increased bacterial diversity and lactic acid production and lowered pH to about 5. The importance of Cu2+, Zn2+, Fe2+ and I- is different for Bacillus growth with the order Zn2+> Fe2+>Cu2+> I- in a 21-d fermentation and Cu2+>I->Fe2+>Zn2+ in a 42-d fermentation. Cu2+, Zn2+, Fe2+ and I- is recommended at a level of 150, 60, 150 and 0.6 mg/kg respectively for the production of fermented liquid diet with Bacillus subtilis. The findings improve our understanding of the influence of trace elements on liquid diet fermentation with probiotics and support the proper use of trace elements in the production of fermented liquid diet for piglets.

  14. Selective labelling and eradication of antibiotic-tolerant bacterial populations in Pseudomonas aeruginosa biofilms

    Science.gov (United States)

    Chua, Song Lin; Yam, Joey Kuok Hoong; Hao, Piliang; Adav, Sunil S.; Salido, May Margarette; Liu, Yang; Givskov, Michael; Sze, Siu Kwan; Tolker-Nielsen, Tim; Yang, Liang

    2016-01-01

    Drug resistance and tolerance greatly diminish the therapeutic potential of antibiotics against pathogens. Antibiotic tolerance by bacterial biofilms often leads to persistent infections, but its mechanisms are unclear. Here we use a proteomics approach, pulsed stable isotope labelling with amino acids (pulsed-SILAC), to quantify newly expressed proteins in colistin-tolerant subpopulations of Pseudomonas aeruginosa biofilms (colistin is a ‘last-resort' antibiotic against multidrug-resistant Gram-negative pathogens). Migration is essential for the formation of colistin-tolerant biofilm subpopulations, with colistin-tolerant cells using type IV pili to migrate onto the top of the colistin-killed biofilm. The colistin-tolerant cells employ quorum sensing (QS) to initiate the formation of new colistin-tolerant subpopulations, highlighting multicellular behaviour in antibiotic tolerance development. The macrolide erythromycin, which has been previously shown to inhibit the motility and QS of P. aeruginosa, boosts biofilm eradication by colistin. Our work provides insights on the mechanisms underlying the formation of antibiotic-tolerant populations in bacterial biofilms and indicates research avenues for designing more efficient treatments against biofilm-associated infections. PMID:26892159

  15. BOX-PCR-based identification of bacterial species belonging to Pseudomonas syringae: P. viridiflava group

    Directory of Open Access Journals (Sweden)

    Abi S.A. Marques

    2008-01-01

    Full Text Available The phenotypic characteristics and genetic fingerprints of a collection of 120 bacterial strains, belonging to Pseudomonas syringae sensu lato group, P. viridiflava and reference bacteria were evaluated, with the aim of species identification. The numerical analysis of 119 nutritional characteristics did not show patterns that would help with identification. Regarding the genetic fingerprinting, the results of the present study supported the observation that BOX-PCR seems to be able to identify bacterial strains at species level. After numerical analyses of the bar-codes, all pathovars belonging to each one of the nine described genomospecies were clustered together at a distance of 0.72, and could be separated at genomic species level. Two P. syringae strains of unknown pathovars (CFBP 3650 and CFBP 3662 and the three P. syringae pv. actinidiae strains were grouped in two extra clusters and might eventually constitute two new species. This genomic species clustering was particularly evident for genomospecies 4, which gathered P. syringae pvs. atropurpurea, coronafaciens, garçae, oryzae, porri, striafaciens, and zizaniae at a noticeably low distance.

  16. The Pseudomonas aeruginosa chemotaxis methyltransferase CheR1 impacts on bacterial surface sampling.

    Directory of Open Access Journals (Sweden)

    Juliane Schmidt

    Full Text Available The characterization of factors contributing to the formation and development of surface-associated bacterial communities known as biofilms has become an area of intense interest since biofilms have a major impact on human health, the environment and industry. Various studies have demonstrated that motility, including swimming, swarming and twitching, seems to play an important role in the surface colonization and establishment of structured biofilms. Thereby, the impact of chemotaxis on biofilm formation has been less intensively studied. Pseudomonas aeruginosa has a very complex chemosensory system with two Che systems implicated in flagella-mediated motility. In this study, we demonstrate that the chemotaxis protein CheR1 is a methyltransferase that binds S-adenosylmethionine and transfers a methyl group from this methyl donor to the chemoreceptor PctA, an activity which can be stimulated by the attractant serine but not by glutamine. We furthermore demonstrate that CheR1 does not only play a role in flagella-mediated chemotaxis but that its activity is essential for the formation and maintenance of bacterial biofilm structures. We propose a model in which motility and chemotaxis impact on initial attachment processes, dispersion and reattachment and increase the efficiency and frequency of surface sampling in P. aeruginosa.

  17. Long-distance delivery of bacterial virulence factors by Pseudomonas aeruginosa outer membrane vesicles.

    Directory of Open Access Journals (Sweden)

    Jennifer M Bomberger

    2009-04-01

    Full Text Available Bacteria use a variety of secreted virulence factors to manipulate host cells, thereby causing significant morbidity and mortality. We report a mechanism for the long-distance delivery of multiple bacterial virulence factors, simultaneously and directly into the host cell cytoplasm, thus obviating the need for direct interaction of the pathogen with the host cell to cause cytotoxicity. We show that outer membrane-derived vesicles (OMV secreted by the opportunistic human pathogen Pseudomonas aeruginosa deliver multiple virulence factors, including beta-lactamase, alkaline phosphatase, hemolytic phospholipase C, and Cif, directly into the host cytoplasm via fusion of OMV with lipid rafts in the host plasma membrane. These virulence factors enter the cytoplasm of the host cell via N-WASP-mediated actin trafficking, where they rapidly distribute to specific subcellular locations to affect host cell biology. We propose that secreted virulence factors are not released individually as naked proteins into the surrounding milieu where they may randomly contact the surface of the host cell, but instead bacterial derived OMV deliver multiple virulence factors simultaneously and directly into the host cell cytoplasm in a coordinated manner.

  18. Unexpected convergence of fungal and bacterial communities during fermentation of traditional Korean alcoholic beverages inoculated with various natural starters.

    Science.gov (United States)

    Jung, Mi-Ja; Nam, Young-Do; Roh, Seong Woon; Bae, Jin-Woo

    2012-05-01

    Makgeolli is a traditional Korean alcoholic beverage manufactured with a natural starter, called nuruk, and grains. Nuruk is a starchy disk or tablet formed from wheat or grist containing various fungal and bacterial strains from the surrounding environment that are allowed to incorporate naturally into the starter, each of which simultaneously participates in the makgeolli fermentation process. In the current study, changes in microbial dynamics during laboratory-scale fermentation of makgeolli inoculated with six different kinds of nuruk were evaluated by barcoded pyrosequencing using fungal- and bacterial-specific primers targeting the internal transcribed spacer 2 region and hypervariable regions V1 to V3 of the 16S rRNA gene, respectively. A total of 61,571 fungal and 68,513 bacterial sequences were used for the analysis of microbial diversity in ferment samples. During fermentation, the proportion of fungal microorganisms belonging to the family Saccharomycetaceae increased significantly, and the major bacterial phylum of the samples shifted from γ-Proteobacteria to Firmicutes. The results of quantitative PCR indicated that the bacterial content in the final ferments was higher than in commercial rice beers, while total fungi appeared similar. This is the first report of a comparative analysis of bacterial and fungal dynamics in parallel during the fermentation of Korean traditional alcoholic beverage using barcoded pyrosequencing. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Changes in the bacterial community in the fermentation process of kôso, a Japanese sugar-vegetable fermented beverage.

    Science.gov (United States)

    Chiou, Tai-Ying; Suda, Wataru; Oshima, Kenshiro; Hattori, Masahira; Takahashi, Tomoya

    2017-02-01

    Kôso is a Japanese fermented beverage made with over 20 kinds of vegetables, mushrooms, and sugars. The changes in the bacterial population of kôso during fermentation at 25 °C over a period of 10 days were studied using 454 pyrosequencing of the 16S rRNA gene. The analysis detected 224 operational taxonomic units (OTUs) clustered from 8 DNA samples collected on days 0, 3, 7, and 10 from two fermentation batches. Proteobacteria were the dominant phylum in the starting community, but were replaced by Firmicutes within three days. Seventy-eight genera were identified from the 224 OTUs, in which Bifidobacterium, Leuconostoc, Lactococcus, and Lactobacillus dominated, accounting for over 96% of the total bacterial population after three days' fermentation. UniFrac-Principal Coordinate Analysis of longitudinal fermented samples revealed dramatic changes in the bacterial community in kôso, resulting in significantly low diversity at the end of fermentation as compared with the complex starting community.

  20. Conversion of squid pen by Pseudomonas aeruginosa K187 fermentation for the production of N-acetyl chitooligosaccharides and biofertilizers.

    Science.gov (United States)

    Wang, San-Lang; Hsu, Wan-Han; Liang, Tzu-Wen

    2010-05-07

    Pseudomonas aeruginosa K187, a protease- and chitinase-producing bacterium, exhibited protease and chitinase activity after three and five days of incubation, respectively. The protease and chitinase were both produced by using 1% squid pen powder (SPP) (w/v) as sole carbon and nitrogen source. After fermentation, the deproteinization rate of the recovered squid pen gradually increased up to 68% on the fourth day. After five days of fermentation, the production of GlcNAc, (GlcNAc)(2), (GlcNAc)(3), (GlcNAc)(4) and (GlcNAc)(5) were 1.18mg/mL, 0.76mg/mL, 1.02mg/mL, 0.93mg/mL and 0.90mg/mL, respectively. The culture supernatant of K187 also exhibited activity of enhancing vegetable growth. For Brassica chinensis Linn treated with the fifth day culture supernatant, the total weight and total length increased up to 529% and 148%, respectively, compared to the control group. With this method, the production of protease, chitinase, N-acetyl chitooligosaccharides and biofertilizers may be useful for biological applications.

  1. Anaerobic survival of Pseudomonas aeruginosa by pyruvate fermentation requires an Usp-type stress protein

    DEFF Research Database (Denmark)

    Schreiber, K; Boes, N; Escbach, M

    2006-01-01

    activity was detected in the deeper layers of a P. aeruginosa biofilm using a PPA3309-gfp (green fluorescent protein gene) fusion and confocal laser-scanning microscopy. This is the first description of an Anr-dependent, anaerobically induced, and functional Usp-like protein in bacteria....... the induced synthesis of three enzymes involved in arginine fermentation, ArcA, ArcB, and ArcC, and the outer membrane protein OprL. Moreover, formation of two proteins of unknown function, PA3309 and PA4352, increased by factors of 72- and 22-fold, respectively. Both belong to the group of universal stress...... proteins (Usp). Long-term survival of a PA3309 knockout mutant by pyruvate fermentation was found drastically reduced. The oxygen-sensing regulator Anr controls expression of the PPA3309-lacZ reporter gene fusion after a shift to anaerobic conditions and further pyruvate fermentation. PA3309 expression...

  2. Reducing bacterial contamination in fuel ethanol fermentations by ozone treatment of uncooked corn mash.

    Science.gov (United States)

    Rasmussen, Mary L; Koziel, Jacek A; Jane, Jay-lin; Pometto, Anthony L

    2015-06-03

    Ozonation of uncooked corn mash from the POET BPX process was investigated as a potential disinfection method for reducing bacterial contamination prior to ethanol fermentation. Corn mash (200 g) was prepared from POET ground corn and POET corn slurry and was ozonated in 250 mL polypropylene bottles. Lactic and acetic acid levels were monitored daily during the fermentation of ozonated, aerated, and nontreated corn mash samples to evaluate bacterial activity. Glycerol and ethanol contents of fermentation samples were checked daily to assess yeast activity. No yeast supplementation, no addition of other antimicrobial agents (such as antibiotics), and spiking with a common lactic acid bacterium found in corn ethanol plants, Lactobacillus plantarum, amplified the treatment effects. The laboratory-scale ozone dosages ranged from 26-188 mg/L, with very low estimated costs of $0.0008-0.006/gal ($0.21-1.6/m(3)) of ethanol. Ozonation was found to decrease the initial pH of ground corn mash samples, which could reduce the sulfuric acid required to adjust the pH prior to ethanol fermentation. Lactic and acetic acid levels tended to be lower for samples subjected to increasing ozone dosages, indicating less bacterial activity. The lower ozone dosages in the range applied achieved higher ethanol yields. Preliminary experiments on ozonating POET corn slurry at low ozone dosages were not as effective as using POET ground corn, possibly because corn slurry samples contained recycled antimicrobials from the backset. The data suggest additional dissolved and suspended organic materials from the backset consumed the ozone or shielded the bacteria.

  3. Pseudomonas chlororaphis Produces Two Distinct R-Tailocins That Contribute to Bacterial Competition in Biofilms and on Roots.

    Science.gov (United States)

    Dorosky, Robert J; Yu, Jun Myoung; Pierson, Leland S; Pierson, Elizabeth A

    2017-08-01

    R-type tailocins are high-molecular-weight bacteriocins that resemble bacteriophage tails and are encoded within the genomes of many Pseudomonas species. In this study, analysis of the P. chlororaphis 30-84 R-tailocin gene cluster revealed that it contains the structural components to produce two R-tailocins of different ancestral origins. Two distinct R-tailocin populations differing in length were observed in UV-induced lysates of P. chlororaphis 30-84 via transmission electron microscopy. Mutants defective in the production of one or both R-tailocins demonstrated that the killing spectrum of each tailocin is limited to Pseudomonas species. The spectra of pseudomonads killed by the two R-tailocins differed, although a few Pseudomonas species were either killed by or insusceptible to both tailocins. Tailocin release was disrupted by deletion of the holin gene within the tailocin gene cluster, demonstrating that the lysis cassette is required for the release of both R-tailocins. The loss of functional tailocin production reduced the ability of P. chlororaphis 30-84 to compete with an R-tailocin-sensitive strain within biofilms and rhizosphere communities. Our study demonstrates that Pseudomonas species can produce more than one functional R-tailocin particle sharing the same lysis cassette but differing in their killing spectra. This study provides evidence for the role of R-tailocins as determinants of bacterial competition among plant-associated Pseudomonas in biofilms and the rhizosphere.IMPORTANCE Recent studies have identified R-tailocin gene clusters potentially encoding more than one R-tailocin within the genomes of plant-associated Pseudomonas but have not demonstrated that more than one particle is produced or the ecological significance of the production of multiple R-tailocins. This study demonstrates for the first time that Pseudomonas strains can produce two distinct R-tailocins with different killing spectra, both of which contribute to bacterial

  4. Industrial vitamin B12 production by Pseudomonas denitrificans using maltose syrup and corn steep liquor as the cost-effective fermentation substrates.

    Science.gov (United States)

    Xia, Wei; Chen, Wei; Peng, Wei-Fu; Li, Kun-Tai

    2015-06-01

    The aerobic Pseudomonas denitrificans is widely used for industrial and commercial vitamin B12 fermentation, due to its higher productivity compared to the anaerobic vitamin B12-producing microorganisms. This paper aimed to develop a cost-effective fermentation medium for industrial vitamin B12 production by P. denitrificans in 120,000-l fermenter. It was found that maltose syrup (a low-cost syrup from corn starch by means of enzymatic or acid hydrolysis) and corn steep liquor (CSL, a by-product of starch industry) were greatly applicable to vitamin B12 production by P. denitrificans. Under the optimal fermentation medium performed by response surface methodology, 198.27 ± 4.60 mg/l of vitamin B12 yield was obtained in 120,000-l fermenter, which was close to the fermentation with the refined sucrose (198.80 mg/l) and was obviously higher than that obtained under beet molasses utilization (181.75 mg/l). Therefore, maltose syrups and CSL were the efficient and economical substrates for industrial vitamin B12 fermentation by P. denitrificans.

  5. Bacterial diversity and mycotoxin reduction during maize fermentation (steeping for ogi production

    Directory of Open Access Journals (Sweden)

    Chiamaka A Okeke

    2015-12-01

    Full Text Available Bacterial diversity and community structure of two maize varieties (white and yellow during fermentation/steeping for ogi production, and the influence of spontaneous fermentation on mycotoxin reduction in the gruel were studied. A total of 142 bacterial isolates obtained at 24–96h intervals were preliminarily identified by conventional microbiological methods while 60 selected isolates were clustered into 39 OTUs consisting of 15 species, 10 genera and 3 phyla by 16S rRNA sequence analysis. Lactic acid bacteria constituted about 63% of all isolated bacteria and the genus Pediococcus dominated (white maize = 84.8%; yellow maize = 74.4%. Pediococcus acidilactici and Lactobacillus paraplantarum were found at all steeping intervals of white and yellow maize, respectively, while P. claussenii was present only at the climax stage of steeping white maize. In both maize varieties, P. pentosaceus was found at 24–72h. Mycotoxin concentrations (µg/kg in the unsteeped grains were: white maize (aflatoxin B1 = 0.60; citrinin = 85.8; cyclopiazonic acid = 23.5; fumonisins (B1/B2/B3 = 68.4–483; zearalenone = 3.3 and yellow maize (aflatoxins (B1/B2/M1 = 22.7–513; citrinin = 16,800; cyclopiazonic acid = 247; fumonisins (B1/B2/B3 = 252–1,586; zearalenone = 205. Mycotoxins in both maize varieties were significantly (p<0.05 reduced across steeping periods. This study reports for the first time: (a the association of L. paraplantarum, P. acidilactici and P. claussenii with ogi production from maize, (b citrinin occurrence in Nigerian maize and ogi, and (c aflatoxin M1, citrinin and cyclopiazonic acid degradation/loss due to fermentation in traditional cereal-based fermented food.

  6. Pseudomonas alkylphenolica sp. nov., a bacterial species able to form special aerial structures when grown on p-cresol.

    Science.gov (United States)

    Mulet, Magdalena; Sánchez, David; Lalucat, Jorge; Lee, Kyoung; García-Valdés, Elena

    2015-11-01

    Pseudomonas sp. KL28T is an aerobic, rod-shaped bacterium that was isolated from the soil of Changwon, South Korea, based on its ability to grow in the presence of linear alkylphenols (C1-C5). Despite several studies on strain KL28T, it could not be assigned to any known species in the genus Pseudomonas. The name 'Pseudomonas alkylphenolia' was proposed for KL28T, but the strain had not until now been characterized taxonomically and the name currently has no standing in the bacterial nomenclature. A 16S rRNA gene sequence based phylogenetic analysis suggested an affiliation of strain KL28T with the Pseudomonas putida group, with Pseudomonas vranovensis DSM 16006T as the most closely related type strain (99.1 % similarity). A multilocus phylogenetic sequence analysis performed by concatenating 16S rRNA, gyrB, rpoD and rpoB partial gene sequences showed that isolate KL28T could be differentiated from P. vranovensis DSM 16006T (sequence similarity 93.7 %). Genomic comparisons of strain KL28T with the type strains of the species in the P. putida group using average nucleotide index based on blast (ANIb) and genome-to genome distances (GGDC) revealed 87.06 % and 32.20 % similarities with P. vranovensis DSM 16006T, respectively, as the closest type strain. Both values are far from the thresholds established for species differentiation. These results, together with differences in phenotypic features and chemotaxonomic analyses [fatty acids and whole-cell matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS], support the proposal of strain KL28T ( = JCM 16553T = KCTC 22206T) as the type strain of a novel species, for which the formerly proposed name, 'P. alkylphenolia', is correctly latinized as Pseudomonas alkylphenolica sp. nov.

  7. Effect of Single Bacterial Starter Culture on Odour Reduction During Controlled Fermentation of Cassava Tubers for Foofoo Production

    OpenAIRE

    Henshaw, E. E.; Ikpoh, I. S

    2010-01-01

    Effects of single bacterial starter culture on odour reduction during controlled fermentation of cassava tubers for foofoo production were investigated. Pure cultures were used to ferment cassava tubers in water for 96 h. The cultures used include Bacillus subtilis, Klebsiela sp., Lactobacillus plantarum and Leuconostoc mesenteroides. L. plantarum exhibited the highest acid producing ability, decreasing the pH of the Cassava tubers from 6.2 to 3.68 with a corresponding increase in total titra...

  8. Simultaneous production of lactobionic and gluconic acid in cheese whey/glucose co-fermentation by Pseudomonas taetrolens.

    Science.gov (United States)

    Alonso, Saúl; Rendueles, Manuel; Díaz, Mario

    2015-11-01

    Substrate versatility of Pseudomonas taetrolens was evaluated for the first time in a co-fermentation system combining cheese whey and glucose, glycerol or lactose as co-substrates. Results showed that P. taetrolens displayed different production patterns depending on the co-substrate supplied. Whereas the presence of glucose led to a simultaneous co-production of lactobionic (78g/L) and gluconic acid (8.8g/L), lactose feeding stimulated the overproduction of lactobionic acid from whey with a high specific productivity (1.4g/gh) and yield (100%). Co-substrate supply of glycerol conversely led to reduced lactobionic acid yield (82%) but higher cell densities (1.8g/L), channelling the carbon source towards cell growth and maintenance. Higher carbon availability impaired the metabolic activity as well as membrane integrity, whereas lactose feeding improved the cellular functionality of P. taetrolens. Insights into these mixed carbon source strategies open up the possibility of co-producing lactobionic and gluconic acid into an integrated single-cell biorefinery. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Evaluating the possibility of using acetone-butanol-ethanol (ABE) fermentation wastewater for bacterial cellulose production by Gluconacetobacter xylinus.

    Science.gov (United States)

    Huang, C; Yang, X-Y; Xiong, L; Guo, H-J; Luo, J; Wang, B; Zhang, H-R; Lin, X-Q; Chen, X-D

    2015-05-01

    To reduce the cost of bacterial cellulose (BC) production, the possibility of using acetone-butanol-ethanol (ABE) fermentation wastewater with high COD value (18 050 mg l(-1) ) for BC production by Gluconacetobacter xylinus was evaluated. After 7 days of fermentation, the highest BC yield (1·34 g l(-1) ) was obtained. The carbon sources including sugars (glucose and xylose), organic acids (acetic acid and butyric acid) and alcohol compounds (ethanol and butanol) were utilized by G. xylinus simultaneously during fermentation. Although the COD decrease ratio (about 14·7%) was low, the highest BC yield on COD consumption (56·2%, g g(-1) ) was relatively high and the remaining wastewater could be used for further BC fermentation. Besides, the environment of ABE fermentation wastewater showed small influence on the BC structure by comparison with the BC products obtained in traditional HS medium using field emission scanning electron microscope (FE-SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Overall, ABE fermentation wastewater is one promising substrate for BC production. The possibility of using acetone-butanol-ethanol (ABE) fermentation wastewater for bacterial cellulose (BC) production by Gluconacetobacter xylinus was evaluated in this study. This is the first time that ABE fermentation wastewater was used as substrate for BC fermentation. The results provide detail information of metabolism of G. xylinus in ABE fermentation wastewater and the influence of wastewater environment on the structure of BC samples. Overall, this bioconversion could reduce the cost of BC production greatly. © 2015 The Society for Applied Microbiology.

  10. Effect of on Rumen Fermentation Characteristics of Dried Brewers Grain, Methane Production and Bacterial Diversity

    Directory of Open Access Journals (Sweden)

    Alvin P. Soriano

    2014-11-01

    Full Text Available The effects of Lactobacillus mucosae (L. mucosae, a potential direct fed microbial previously isolated from the rumen of Korean native goat, on the rumen fermentation profile of brewers grain were evaluated. Fermentation was conducted in serum bottles each containing 1% dry matter (DM of the test substrate and either no L. mucosae (control, 1% 24 h broth culture of L. mucosae (T1, or 1% inoculation with the cell-free culture supernatant (T2. Each serum bottle was filled anaerobically with 100 mL of buffered rumen fluid and sealed prior to incubation for 0, 6, 12, 24, and 48 h from which fermentation parameters were monitored and the microbial diversity was evaluated. The results revealed that T1 had higher total gas production (65.00 mL than the control (61.33 mL and T2 (62.00 mL (p<0.05 at 48 h. Consequently, T1 had significantly lower pH values (p<0.05 than the other groups at 48 h. Ammonia nitrogen (NH3-N, individual and total volatile fatty acids (VFA concentration and acetate:propionate ratio were higher in T1 and T2 than the control, but T1 and T2 were comparable for these parameters. Total methane (CH4 production and carbon dioxide (CO2 were highest in T1. The percent DM and organic matter digestibilities were comparable between all groups at all times of incubation. The total bacterial population was significantly higher in T1 (p<0.05 at 24 h, but then decreased to levels comparable to the control and T2 at 48 h. The denaturing gradient gel electrophoresis profile of the total bacterial 16s rRNA showed higher similarity between T1 and T2 at 24 h and between the control and T1 at 48 h. Overall, these results suggest that addition of L. mucosae and cell-free supernatant during the in vitro fermentation of dried brewers grain increases the VFA production, but has no effect on digestibility. The addition of L. mucosae can also increase the total bacterial population, but has no significant effect on the total microbial diversity. However

  11. Biodegradation of Palm Kernel Cake by Cellulolytic and Hemicellulolytic Bacterial Cultures through Solid State Fermentation

    Directory of Open Access Journals (Sweden)

    Mohamed Idris Alshelmani

    2014-01-01

    Full Text Available Four cellulolytic and hemicellulolytic bacterial cultures were purchased from the Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Culture (DSMZ and the American Type Culture Collection (ATCC. Two experiments were conducted; the objective of the first experiment was to determine the optimum time period required for solid state fermentation (SSF of palm kernel cake (PKC, whereas the objective of the second experiment was to investigate the effect of combinations of these cellulolytic and hemicellulolytic bacteria on the nutritive quality of the PKC. In the first experiment, the SSF was lasted for 12 days with inoculum size of 10% (v/w on different PKC to moisture ratios. In the second experiment, fifteen combinations were created among the four microbes with one untreated PKC as a control. The SSF lasted for 9 days, and the samples were autoclaved, dried, and analyzed for proximate analysis. Results showed that bacterial cultures produced high enzymes activities at the 4th day of SSF, whereas their abilities to produce enzymes tended to be decreased to reach zero at the 8th day of SSF. Findings in the second experiment showed that hemicellulose and cellulose was significantly P<0.05 decreased, whereas the amount of reducing sugars were significantly P<0.05 increased in the fermented PKC (FPKC compared with untreated PKC.

  12. Decolorization of industrial synthetic dyes using engineered Pseudomonas putida cells with surface-immobilized bacterial laccase

    Science.gov (United States)

    2012-01-01

    Background Microbial laccases are highly useful in textile effluent dye biodegradation. However, the bioavailability of cellularly expressed or purified laccases in continuous operations is usually limited by mass transfer impediment or enzyme regeneration difficulty. Therefore, this study develops a regenerable bacterial surface-displaying system for industrial synthetic dye decolorization, and evaluates its effects on independent and continuous operations. Results A bacterial laccase (WlacD) was engineered onto the cell surface of the solvent-tolerant bacterium Pseudomonas putida to construct a whole-cell biocatalyst. Ice nucleation protein (InaQ) anchor was employed, and the ability of 1 to 3 tandemly aligned N-terminal repeats to direct WlacD display were compared. Immobilized WlacD was determined to be surface-displayed in functional form using Western blot analysis, immunofluorescence microscopy, flow cytometry, and whole-cell enzymatic activity assay. Engineered P. putida cells were then applied to decolorize the anthraquinone dye Acid Green (AG) 25 and diazo-dye Acid Red (AR) 18. The results showed that decolorization of both dyes is Cu2+- and mediator-independent, with an optimum temperature of 35°C and pH of 3.0, and can be stably performed across a temperature range of 15°C to 45°C. A high activity toward AG25 (1 g/l) with relative decolorization values of 91.2% (3 h) and 97.1% (18 h), as well as high activity to AR18 (1 g/l) by 80.5% (3 h) and 89.0% (18 h), was recorded. The engineered system exhibited a comparably high activity compared with those of separate dyes in a continuous three-round shake-flask decolorization of AG25/AR18 mixed dye (each 1 g/l). No significant decline in decolorization efficacy was noted during first two-rounds but reaction equilibriums were elongated, and the residual laccase activity eventually decreased to low levels. However, the decolorizing capacity of the system was easily retrieved via a subsequent 4-h

  13. Decolorization of industrial synthetic dyes using engineered Pseudomonas putida cells with surface-immobilized bacterial laccase

    Directory of Open Access Journals (Sweden)

    Wang Wei

    2012-06-01

    Full Text Available Abstract Background Microbial laccases are highly useful in textile effluent dye biodegradation. However, the bioavailability of cellularly expressed or purified laccases in continuous operations is usually limited by mass transfer impediment or enzyme regeneration difficulty. Therefore, this study develops a regenerable bacterial surface-displaying system for industrial synthetic dye decolorization, and evaluates its effects on independent and continuous operations. Results A bacterial laccase (WlacD was engineered onto the cell surface of the solvent-tolerant bacterium Pseudomonas putida to construct a whole-cell biocatalyst. Ice nucleation protein (InaQ anchor was employed, and the ability of 1 to 3 tandemly aligned N-terminal repeats to direct WlacD display were compared. Immobilized WlacD was determined to be surface-displayed in functional form using Western blot analysis, immunofluorescence microscopy, flow cytometry, and whole-cell enzymatic activity assay. Engineered P. putida cells were then applied to decolorize the anthraquinone dye Acid Green (AG 25 and diazo-dye Acid Red (AR 18. The results showed that decolorization of both dyes is Cu2+- and mediator-independent, with an optimum temperature of 35°C and pH of 3.0, and can be stably performed across a temperature range of 15°C to 45°C. A high activity toward AG25 (1 g/l with relative decolorization values of 91.2% (3 h and 97.1% (18 h, as well as high activity to AR18 (1 g/l by 80.5% (3 h and 89.0% (18 h, was recorded. The engineered system exhibited a comparably high activity compared with those of separate dyes in a continuous three-round shake-flask decolorization of AG25/AR18 mixed dye (each 1 g/l. No significant decline in decolorization efficacy was noted during first two-rounds but reaction equilibriums were elongated, and the residual laccase activity eventually decreased to low levels. However, the decolorizing capacity of the system was easily retrieved

  14. Decolorization of industrial synthetic dyes using engineered Pseudomonas putida cells with surface-immobilized bacterial laccase.

    Science.gov (United States)

    Wang, Wei; Zhang, Zhen; Ni, Hong; Yang, Xiaomeng; Li, Qianqian; Li, Lin

    2012-06-11

    Microbial laccases are highly useful in textile effluent dye biodegradation. However, the bioavailability of cellularly expressed or purified laccases in continuous operations is usually limited by mass transfer impediment or enzyme regeneration difficulty. Therefore, this study develops a regenerable bacterial surface-displaying system for industrial synthetic dye decolorization, and evaluates its effects on independent and continuous operations. A bacterial laccase (WlacD) was engineered onto the cell surface of the solvent-tolerant bacterium Pseudomonas putida to construct a whole-cell biocatalyst. Ice nucleation protein (InaQ) anchor was employed, and the ability of 1 to 3 tandemly aligned N-terminal repeats to direct WlacD display were compared. Immobilized WlacD was determined to be surface-displayed in functional form using Western blot analysis, immunofluorescence microscopy, flow cytometry, and whole-cell enzymatic activity assay. Engineered P. putida cells were then applied to decolorize the anthraquinone dye Acid Green (AG) 25 and diazo-dye Acid Red (AR) 18. The results showed that decolorization of both dyes is Cu(2+)- and mediator-independent, with an optimum temperature of 35°C and pH of 3.0, and can be stably performed across a temperature range of 15°C to 45°C. A high activity toward AG25 (1 g/l) with relative decolorization values of 91.2% (3 h) and 97.1% (18 h), as well as high activity to AR18 (1 g/l) by 80.5% (3 h) and 89.0% (18 h), was recorded. The engineered system exhibited a comparably high activity compared with those of separate dyes in a continuous three-round shake-flask decolorization of AG25/AR18 mixed dye (each 1 g/l). No significant decline in decolorization efficacy was noted during first two-rounds but reaction equilibriums were elongated, and the residual laccase activity eventually decreased to low levels. However, the decolorizing capacity of the system was easily retrieved via a subsequent 4-h cell culturing

  15. In Vitro Rumen Fermentation and Anti Mastitis Bacterial Activity of Diet Containing Betel Leaf Meal (Piper betle L.

    Directory of Open Access Journals (Sweden)

    A. A. Yamin

    2013-08-01

    Full Text Available The aims of this experiment was to study the inhibition effect of betel leaf meal (BLM addition into concentrate diet on mastitis causing bacteria and on rumen fermentation condition. The study consisted of five dietary treatments of BLM level in concentrate feed, i.e., 0%, 2%, 4%, 6%, and 8% and four replicates of each treatment. The treatment diets together with napier grass in ratio of 40 : 60 were fermented using rumen liquor. All treatments were examined their antibacterial activity before and after fermentation. After four hours fermentation, supernatant of each samples were analyzed for VFA, NH3, number of bacteria and protozoa. Dry matter (DM and organic matter (OM digestibility were analyzed after 48 h fermentation. The results showed that before fermentation, 8% BLM addition caused the bigest (P<0.05 inhibition diameter of Staphylococcus spp. growth compared to other lower levels. However after fermentation there were no significant differences among the addition levels of BLM. Two per cent of BLM addition produced higher VFA (P<0.05 than the other addition levels. Ammonia concentration, dry matter (DM and organic matter (OM digestibility were not different among the treatments. Addition of BLM significantly (P<0.01 decreased protozoa number, but did not affect bacterial count. It is concluded that the addition of 2% BLM in concentrate feed can be used effectively to inhibit the growth of mastitis causing bacteria (Staphylococcus spp. and does not disturb rumen fermentation condition.

  16. Characteristics of Bacterial Strains from Pseudomonas Genera Isolated from Diseased Plum Trees

    Directory of Open Access Journals (Sweden)

    Veljko Gavrilović

    2008-01-01

    Full Text Available Characteristics of Pseudomonas syringae strains isolated from diseased plum trees are presented is this paper. Based on pathogenic, biochemical and physiological characteristics, isolated starins were divided into two groups: First group of strains, isolated from diseased plum branches with symptoms of suden decay, was simillar to Pseudomonas syringae pv. syringae; second group of strains, isolated from necrotic flower buds on plum trees, exhibited characteristics simillar to Pseudomonas syringae pv. morsprunorum. In addition, phytopathogenic fungi belonging to genera Phomopsis, Botryosphaeria and Leucostoma, were also isolated from diseased plum trees. Further study of these pathogens and their role in the epidemiology of suden plum trees decay is in progress.

  17. Controle biológico da murcha bacteriana do tomateiro, por Pseudomonas spp. fluorescentes Biological control of bacterial wilt of tomato by fluorescent Pseudomonas spp

    Directory of Open Access Journals (Sweden)

    Ana Rosa Peixoto

    1997-03-01

    Full Text Available Esta revisão bibliográfica teve como objetivo avaliar o potencial de antagonismo de espécies de Pseudomonas fluorescentes a Pseudomonas solanacearum, agente causal da murcha bacteriana do tomateiro. Devido a dificuldade encontrada nas estratégias utilizadas para o controle da Murcha Bacteriana por meio de métodos convencionais, alguns outros tem sido estudados, como o uso de microrganismos benéficos. As rizobactérias vem proporcionando solução viável a algumas doenças consideradas de difícil manejo. Dentre os mecanismos que tem sido sugeridos para o controle microbiano de patógenos de plantas, através do uso de rizobactérias fluorescentes, citamse produção de antibióticos, bactericinas, enzimas titicas, competição por espaço e nutrientes. Possuem uma alta capacidade de colonização e sobrevivência no hospedeiro, falares que são importantes no estabelecimento e introdução de microrganismos na rizosfera. Estas bactérias podem também incitar um aumento no desenvolvimento e na produção do hospedeiro, sendo denominadas de rizobactérias promotoras de crescimento de plantas.This literature review has the objetive of evaluating the antagonism potential of species of florescem Pseudomonas to Pseudomonas solanacearum which is the causal agent of bacterial wilt on the tomato crop. Due to serious limitation in the ejficiency of conventional methods of contrai, other strategies have been siudied, such as the use o/beneficiai microrganisms. Rhizobacteria have shown to be a viable alternative in the contrai of some diseases of difficult managmenl. Among the mechanisms which have been suggestedfor microbian control of plantpathogens with fluorescent rhizobacteria, can be used antibiotic production, bacteriocin, uric emimes and competition for colonization and survival capacity on the host. The survival capacity is very important in the introduction and stablishment ofthe microrganisms in the rhizosphere. These bacteria can aiso

  18. Selective suppression of bacterial contaminants by process conditions during lignocellulose based yeast fermentations

    Directory of Open Access Journals (Sweden)

    Albers Eva

    2011-12-01

    Full Text Available Abstract Background Contamination of bacteria in large-scale yeast fermentations is a serious problem and a threat to the development of successful biofuel production plants. Huge research efforts have been spent in order to solve this problem, but additional ways must still be found to keep bacterial contaminants from thriving in these environments. The aim of this project was to develop process conditions that would inhibit bacterial growth while giving yeast a competitive advantage. Results Lactic acid bacteria are usually considered to be the most common contaminants in industrial yeast fermentations. Our observations support this view but also suggest that acetic acid bacteria, although not so numerous, could be a much more problematic obstacle to overcome. Acetic acid bacteria showed a capacity to drastically reduce the viability of yeast. In addition, they consumed the previously formed ethanol. Lactic acid bacteria did not show this detrimental effect on yeast viability. It was possible to combat both types of bacteria by a combined addition of NaCl and ethanol to the wood hydrolysate medium used. As a result of NaCl + ethanol additions the amount of viable bacteria decreased and yeast viability was enhanced concomitantly with an increase in ethanol concentration. The successful result obtained via addition of NaCl and ethanol was also confirmed in a real industrial ethanol production plant with its natural inherent yeast/bacterial community. Conclusions It is possible to reduce the number of bacteria and offer a selective advantage to yeast by a combined addition of NaCl and ethanol when cultivated in lignocellulosic medium such as wood hydrolysate. However, for optimal results, the concentrations of NaCl + ethanol must be adjusted to suit the challenges offered by each hydrolysate.

  19. Exploring the Bacterial Microbiota of Colombian Fermented Maize Dough "Masa Agria" (Maiz Añejo).

    Science.gov (United States)

    Chaves-Lopez, Clemencia; Serio, Annalisa; Delgado-Ospina, Johannes; Rossi, Chiara; Grande-Tovar, Carlos D; Paparella, Antonello

    2016-01-01

    Masa Agria is a naturally fermented maize dough produced in Colombia, very common in the traditional gastronomy. In this study we used culture-dependent and RNA-based pyrosequencing to investigate the bacterial community structure of Masa Agria samples produced in the south west of Colombia. The mean value of cell density was 7.6 log CFU/g of presumptive lactic acid bacteria, 5.4 log cfu/g for presumptive acetic bacteria and 5.6 og CFU/g for yeasts. The abundance of these microorganisms is also responsible for the low pH (3.1-3.7) registered. Although the 16S rRNA pyrosequencing revealed that the analyzed samples were different in bacteria richness and diversity, the genera Lactobacillus, Weissella, and Acetobacter were predominant. In particular, the most common species were Lactobacillus plantarum and Acetobacter fabarum, followed by L. fermentum, L. vaccinostercus, and Pediococcus argentinicus. Several microorganisms of environmental origin, such as Dechloromonas and most of all Sphingobium spp., revealed in each sample, were detected, and also bacteria related to maize, such as Phytoplasma. In conclusion, our results elucidated for the first time the structures of the bacterial communities of Masa Agria samples obtained from different producers, identifying the specific dominant species and revealing a complete picture of the bacterial consortium in this specific niche. The selective pressure of tropical environments may favor microbial biodiversity characterized by a useful technological potential.

  20. Skin-Derived C-Terminal Filaggrin-2 Fragments Are Pseudomonas aeruginosa-Directed Antimicrobials Targeting Bacterial Replication.

    Directory of Open Access Journals (Sweden)

    Britta Hansmann

    2015-09-01

    Full Text Available Soil- and waterborne bacteria such as Pseudomonas aeruginosa are constantly challenging body surfaces. Since infections of healthy skin are unexpectedly rare, we hypothesized that the outermost epidermis, the stratum corneum, and sweat glands directly control the growth of P. aeruginosa by surface-provided antimicrobials. Due to its high abundance in the upper epidermis and eccrine sweat glands, filaggrin-2 (FLG2, a water-insoluble 248 kDa S100 fused-type protein, might possess these innate effector functions. Indeed, recombinant FLG2 C-terminal protein fragments display potent antimicrobial activity against P. aeruginosa and other Pseudomonads. Moreover, upon cultivation on stratum corneum, P. aeruginosa release FLG2 C-terminus-containing FLG2 fragments from insoluble material, indicating liberation of antimicrobially active FLG2 fragments by the bacteria themselves. Analyses of the underlying antimicrobial mechanism reveal that FLG2 C-terminal fragments do not induce pore formation, as known for many other antimicrobial peptides, but membrane blebbing, suggesting an alternative mode of action. The association of the FLG2 fragment with the inner membrane of treated bacteria and its DNA-binding implicated an interference with the bacterial replication that was confirmed by in vitro and in vivo replication assays. Probably through in situ-activation by soil- and waterborne bacteria such as Pseudomonads, FLG2 interferes with the bacterial replication, terminates their growth on skin surface and thus may contributes to the skin's antimicrobial defense shield. The apparent absence of FLG2 at certain body surfaces, as in the lung or of burned skin, would explain their higher susceptibility towards Pseudomonas infections and make FLG2 C-terminal fragments and their derivatives candidates for new Pseudomonas-targeting antimicrobials.

  1. Green and brown propolis: efficient natural biocides for the control of bacterial contamination of alcoholic fermentation of distilled beverage

    Directory of Open Access Journals (Sweden)

    Márcia Justino Rossini Mutton

    2014-12-01

    Full Text Available This study aimed to evaluate the efficiency of natural biocides, brown and green propolis, for the control of bacterial contamination in the production of sugarcane spirit. The treatments consisted of brown and green propolis extracts, ampicillin, and a control and were assessed at the beginning and end of harvest season in ten fermentation cycles. In the microbiological analyses, the lactic acid bacteria were quantified in the inoculum before and after the treatment with biocides, and the viability of yeast cells during fermentation was evaluated. The levels of acids, glycerol, total residual reducing sugars, and ethanol were analyzed for the wine resulting from each fermentation cycle. A reduction in the number of bacterial contaminants in the inoculum in the treatments with the natural biocides was observed, but it did not affect the viability of yeast cells. The control of the contaminants led to the production of higher levels of ethanol and reduced acidity in the wine produced. The results of the use of brown and green propolis to control the growth microorganisms in the fermentation of sugarcane spirit can be of great importance for using alternative strategies to synthetic antibacterials in fermentation processes including other distilled beverage or spirits.

  2. INTESTINAL BACTERIAL TRANSLOCATION IN EXPERIMENTALLY BURNED MICE WITH WOUNDS COLONIZED BY PSEUDOMONAS-AERUGINOSA

    NARCIS (Netherlands)

    MANSON, WL; COENEN, JMFH; KLASEN, HJ; HORWITZ, EH

    1992-01-01

    Translocation of micro-organisms from the gastrointestinal tract may play a role in the pathogenesis of septic complications in severely burned patients. We therefore investigated the influence of burn wound infection with Pseudomonas aeruginosa on translocation in experimentally burned mice. The P.

  3. Analysis of bacterial community during the fermentation of pulque, a traditional Mexican alcoholic beverage, using a polyphasic approach.

    Science.gov (United States)

    Escalante, Adelfo; Giles-Gómez, Martha; Hernández, Georgina; Córdova-Aguilar, María Soledad; López-Munguía, Agustín; Gosset, Guillermo; Bolívar, Francisco

    2008-05-31

    In this study, the characterization of the bacterial community present during the fermentation of pulque, a traditional Mexican alcoholic beverage from maguey (Agave), was determined for the first time by a polyphasic approach in which both culture and non-culture dependent methods were utilized. The work included the isolation of lactic acid bacteria (LAB), aerobic mesophiles, and 16S rDNA clone libraries from total DNA extracted from the maguey sap (aguamiel) used as substrate, after inoculation with a sample of previously produced pulque and followed by 6-h fermentation. Microbiological diversity results were correlated with fermentation process parameters such as sucrose, glucose, fructose and fermentation product concentrations. In addition, medium rheological behavior analysis and scanning electron microscopy in aguamiel and during pulque fermentation were also performed. Our results showed that both culture and non-culture dependent approaches allowed the detection of several new and previously reported species within the alpha-, gamma-Proteobacteria and Firmicutes. Bacteria diversity in aguamiel was composed by the heterofermentative Leuconostoc citreum, L. mesenteroides, L. kimchi, the gamma-Proteobacteria Erwinia rhapontici, Enterobacter spp. and Acinetobacter radioresistens. Inoculation with previously fermented pulque incorporated to the system microbiota, homofermentative lactobacilli related to Lactobacillus acidophilus, several alpha-Proteobacteria such as Zymomonas mobilis and Acetobacter malorum, other gamma-Proteobacteria and an important amount of yeasts, creating a starting metabolic diversity composed by homofermentative and heterofermentative LAB, acetic and ethanol producing microorganisms. At the end of the fermentation process, the bacterial diversity was mainly composed by the homofermentative Lactobacillus acidophilus, the heterofermentative L. mesenteroides, Lactococcus lactis subsp. lactis and the alpha-Proteobacteria A. malorum. After

  4. Relationship between chemical components, bacterial adherence and in vitro fermentation of tropical forage legumes

    Directory of Open Access Journals (Sweden)

    Ana Carolina Fluck

    2013-10-01

    Full Text Available Inclusion of forage legumes in diet may improve tropical ruminant systems productivity and sustainability. However, it is not well stablished which chemical components more impact their nutritional value. The relationship between chemical composition and in vitro fermentation of tropical forage legume was evaluated with the objective of obtaining indicators of their nutritional value. Samples of Crotalaria spectabilis, Cajanus cajan, Macrotyloma axillare, Mucuna aterrina, Stylosantis sp. and Canavalia ensiformis, cut from plants at growth age between 47 to 110 days, were analysed. Total gas production showed negative correlation (P<0.05 with total N (R=-0.51, acid detergent fibre (ADF, R=-0.62 and acid detergent lignin (ADL, R=-0.65, and positive correlation with non-fibre carbohydrates (NFC, R=0.70. Gas production rate was negatively related (P<0.05 to NDF (R=-0.73, ADF (R=-0.62 and ADL (R=-0.74. Ammonia concentration in the incubation medium was positively related (P<0.05 to total (R=0.74 and soluble (R=0.56 N, and negatively related to NFC (R=-0.81. The level of bacterial adhesion on residue of incubation was negatively related (P<0.05 to cell wall components, mainly to ADL (R=-0.57. The inclusion of polyehtylene glycol increased both gas volume and gas production rate whereas decreased ammonia concentration (P<0.05. In conclusion, even at low concentrations tannins impact the in vitro fermentation of tropical legumes. However, among the analyzed chemical components, the ADL was the best indicator of the nutritional value of the tropical forage legumes.

  5. Bacterial Feeders, the Nematode Caenorhabditis elegans and the Flagellate Cercomonas longicauda, have different Effects on Outcome of Competition among the Pseudomonas Biocontrol Strains CHA0 and DSS73

    DEFF Research Database (Denmark)

    Pedersen, Annette; Nybroe, Ole; Winding, Anne

    2009-01-01

    selective feeding flagellate Cercomonas longicauda versus the non-selective feeding nematode Caenorhabditis elegans) influence the abundance of two bacteria that compete for resources in simple model communities. Microcosms consisted of either one gfp-tagged bacterial strain (Pseudomonas fluorescens DSM...

  6. Anti-Pseudomonas aeruginosa IgY antibodies promote bacterial opsonization and augment the phagocytic activity of polymorphonuclear neutrophils

    DEFF Research Database (Denmark)

    Thomsen, Kim; Christophersen, Lars; Jensen, Peter Østrup

    2016-01-01

    observed that egg yolk antibodies (IgY) harvested from White leghorn chickens that target P. aeruginosa opsonize the pathogen and enhance the PMN-mediated respiratory burst and subsequent bacterial killing in vitro. The effects on PMN phagocytic activity were observed in different Pseudomonas aeruginosa...

  7. Bioaugmentation with Pseudomonas sp. strain MHP41 promotes simazine attenuation and bacterial community changes in agricultural soils.

    Science.gov (United States)

    Morgante, Verónica; López-López, Arantxa; Flores, Cecilia; González, Myriam; González, Bernardo; Vásquez, Mónica; Rosselló-Mora, Ramón; Seeger, Michael

    2010-01-01

    Bioremediation is an important technology for the removal of persistent organic pollutants from the environment. Bioaugmentation with the encapsulated Pseudomonas sp. strain MHP41 of agricultural soils contaminated with the herbicide simazine was studied. The experiments were performed in microcosm trials using two soils: soil that had never been previously exposed to s-triazines (NS) and soil that had >20 years of s-triazine application (AS). The efficiency of the bioremediation process was assessed by monitoring simazine removal by HPLC. The simazine-degrading microbiota was estimated using an indicator for respiration combined with most-probable-number enumeration. The soil bacterial community structures and the effect of bioaugmentation on these communities were determined using 16S RNA gene clone libraries and FISH analysis. Bioaugmentation with MHP41 cells enhanced simazine degradation and increased the number of simazine-degrading microorganisms in the two soils. In highly contaminated NS soil, bioaugmentation with strain MHP41 was essential for simazine removal. Comparative analysis of 16S rRNA gene clone libraries from NS and AS soils revealed high bacterial diversity. Bioaugmentation with strain MHP41 promoted soil bacterial community shifts. FISH analysis revealed that bioaugmentation increased the relative abundances of two phylogenetic groups (Acidobacteria and Planctomycetes) in both soils. Although members of the Archaea were metabolically active in these soils, their relative abundance was not altered by bioaugmentation.

  8. Pollen as a possible pathway for the dissemination of Pseudomonas syringae pv. actinide and bacterial canker of kiwifruit

    Directory of Open Access Journals (Sweden)

    Rodanthi TONTOU

    2014-09-01

    Full Text Available Pollen collected in a kiwifruit orchard with symptoms of bacterial canker and naturally contaminated by Pseudomonas syringae pv. actinidiae (Psa, was used to pollinate an experimental orchard, in order to confirm its role, under commercial orchard conditions, in disseminating the pathogen and, possibly, contributing to disease spread. A pollen lot, certified free from Psa, was used with the same methods as a control. Two pollination techniques were used: dusting (dry pollen and spraying (pollen suspension in water. The orchard was monitored during 2 years from experimental pollination, with regular sampling of flowers, fruits, leaves, and vines, to check for Psa as an epiphyte or endophyte, and for bacterial canker symptoms. Psa was recovered from flowers, fruitlets and leaves during the first season, mainly in plots where contaminated pollen had been sprayed in water suspension. From early August until harvesting time (mid-October, Psa detection was possible only on leaves. No symptoms developed during the first season after pollination. No endophytic Psa was detected in pruned vines in the following winter. During the second season, detection and isolation of Psa was erratic, but direct isolation was achieved from four plots. During the second season after pollination, typical leaf symptoms were observed on a few vines, and Psa was isolated and identified. Our results suggest that Psa could be disseminated via contaminated kiwifruit pollen as a pathway for spread of bacterial canker. However, further pollination experiments are needed to establish, beyond any doubt, whether contaminated pollen may contribute to possible disease outbreaks.

  9. One-step purification and characterization of alginate lyase from a clinical Pseudomonas aeruginosa with destructive activity on bacterial biofilm.

    Science.gov (United States)

    Ghadam, Parinaz; Akhlaghi, Fatemeh; Ali, Ahya Abdi

    2017-05-01

    Pseudomonas aeruginosa is a Gram-negative and aerobic rod bacterium that displays mucoid and non-mucoid phenotype. Mucoid strains secrete alginate, which is the main agent of biofilms in chronic P. aeruginosa infections, show high resistance to antibiotics; consequently, the biological disruption of mucoid P. aeruginosa biofilms is an attractive area of study for researchers. Alginate lyase gene (algl) is a member of alginate producing operon which by glycosidase activity produces primer for other enzymes in this cluster. Also this activity can destroy the extracellular alginate; therefore this enzyme participates in alginate production and destruction pathway. Alginate lyase causes detachment of a biofilm by reducing its adhesion to the surfaces, and increases phagocytosis and antibiotic susceptibility. In this study, alginate lyase was purified in just one step and its properties were investigated. The purification was done by affinity chromatography, analysed by SDS-PAGE, and its effect on P. aeruginosa biofilms was surveyed by micro titer plate assay and SEM. The substrate specificity of the enzyme was determined by PCR. Alginate lyase from isolate 48 was purified in one step. It is more thermally resistant than alginate lyase from Pseudomonas aeruginosa PAO1 and poly M, poly G and poly MG alginate were the substrate of this enzyme. Moreover, it has an eradication effect on biofilms from P. aeruginosa 48 and PAO1. In this study an alginate lyase with many characteristics suitable in medicine such as thermal stability, effective on poly M alginate, and bacterial biofilm destructive was introduced and purified.

  10. Pathovars of Pseudomonas syringae Causing Bacterial Brown Spot and Halo Blight in Phaseolus vulgaris L. Are Distinguishable by Ribotyping

    Science.gov (United States)

    González, Ana J.; Landeras, Elena; Mendoza, M. Carmen

    2000-01-01

    Ribotyping was evaluated as a method to differentiate between Pseudomonas syringae pv. phaseolicola and pv. syringae strains causing bacterial brown spot and halo blight diseases in Phaseolus vulgaris L. Ribotyping, with restriction enzymes BglI and SalI and using the Escherichia coli rrnB operon as the probe, differentiated 11 and 14 ribotypes, respectively, and a combination of data from both procedures yielded 19 combined ribotypes. Cluster analysis of the combined ribotypes differentiated the pathovars phaseolicola and syringae, as well as different clonal lineages within these pathovars. The potential of ribotyping to screen for correlations between lineages and factors such as geographical region and/or bean varieties is also reported. PMID:10653764

  11. Application of customised bacterial inoculants for grass haylage production and its effectiveness on nutrient composition and fermentation quality of haylage.

    Science.gov (United States)

    Soundharrajan, Ilavenil; Kim, Da Hye; Srisesharam, Srigopalram; Kuppusamy, Palaniselvam; Park, Hyung Soo; Yoon, Yong Hee; Kim, Won Ho; Song, Young Gil; Choi, Ki Choon

    2017-10-01

    The present study aimed to investigate the efficacy of customised Lactobacillus plantarum KCC-10, KCC-19 and K-46 on nutrient composition and fermentation quality of low moisture Italian ryegrass (IRG) forage. An addition of customised bacterial inoculants (CBI) did not affect the nutrient compositions and digestibility rates of haylage. The lactic acid content was higher in CBI-inoculated haylage, whereas the amount of acetic acid and butyric acid production was significantly reduced than the control. CBI-inoculated haylage exhibited higher numbers of bacterial colonies that reduced the pH of the haylage. Low pH in haylage is an important criterion for preventing undesirable microbial growth and improves fermentation quality of haylage. PCR studies indicated that the DNA of L. plantarum was predominantly amplified. It evidenced that the CBI is the main reason behind the improvement of haylage fermentation as compared to control. Overall results suggested that KCC-10, KCC-19 and K-46 are considered as potent strains for improving fermentation quality of low moisture forage and preserve its stability for a long time.

  12. Effects Due to Rhizospheric Soil Application of an Antagonistic Bacterial Endophyte on Native Bacterial Community and Its Survival in Soil: A Case Study with Pseudomonas aeruginosa from Banana

    Science.gov (United States)

    Thomas, Pious; Sekhar, Aparna C.

    2016-01-01

    Effective translation of research findings from laboratory to agricultural fields is essential for the success of biocontrol or growth promotion trials employing beneficial microorganisms. The rhizosphere is to be viewed holistically as a dynamic ecological niche comprising of diverse microorganisms including competitors and noxious antagonists to the bio-inoculant. This study was undertaken to assess the effects due to the soil application of an endophytic bacterium with multiple pathogen antagonistic potential on native bacterial community and its sustenance in agricultural soil. Pseudomonas aeruginosa was employed as a model system considering its frequent isolation as an endophyte, wide antagonistic effects reported against different phytopathogens and soil pests, and that the species is a known human pathogen which makes its usage in agriculture precarious. Employing the strain ‘GNS.13.2a’ from banana, its survival in field soil and the effects upon soil inoculation were investigated by monitoring total culturable bacterial fraction as the representative indicator of soil microbial community. Serial dilution plating of uninoculated control versus P. aeruginosa inoculated soil from banana rhizosphere indicated a significant reduction in native bacterial cfu soon after inoculation compared with control soil as assessed on cetrimide- nalidixic acid selective medium against nutrient agar. Sampling on day-4 showed a significant reduction in P. aeruginosa cfu in inoculated soil and a continuous dip thereafter registering >99% reduction within 1 week while the native bacterial population resurged with cfu restoration on par with control. This was validated in contained trials with banana plants. Conversely, P. aeruginosa showed static cfu or proliferation in axenic-soil. Lateral introduction of soil microbiome in P. aeruginosa established soil under axenic conditions or its co-incubation with soil microbiota in suspension indicated significant adverse effects by

  13. Characterization of novel bacteriophages for biocontrol of bacterial blight in leek caused by Pseudomonas syringae pv. porri

    Directory of Open Access Journals (Sweden)

    Sofie eRombouts

    2016-03-01

    Full Text Available Pseudomonas syringae pv. porri, the causative agent of bacterial blight in leek (Allium porrum, is increasingly frequent causing problems in leek cultivation. Because of the current lack of control measures, novel bacteriophages were isolated to control this pathogen using phage therapy. Five novel phages were isolated from infected fields in Flanders (vB_PsyM_KIL1, vB_PsyM_KIL2, vB_PsyM_KIL3, vB_PsyM_KIL4 and vB_PsyM_KIL5, and were complemented with one selected host range mutant phage (vB_PsyM_KIL3b. Genome analysis of the phages revealed genome sizes between 90 and 94 kb and an average GC-content of 44.8%. Phylogenomic networking classified them into a novel clade, named the ‘KIL-like viruses’, related to the Felixounalikevirus genus, together with phage phiPsa374 from Pseudomonas syringae pv. actinidiae. In vitro characterization demonstrated the stability and lytic potential of these phages. Host range analysis confirmed heterogeneity within P. syringae pv. porri, leading to the development of a phage cocktail with a range that covers the entire set of 41 strains tested. Specific bio-assays demonstrated the in planta efficacy of phages vB_PsyM_KIL1, vB_PsyM_KIL2, vB_PsyM_KIL3 and vB_PsyM_KIL3b. In addition, two parallel field trial experiments on three locations using a phage cocktail of the six phages showed variable results. In one trial, symptom development was attenuated. These data suggest some potential for phage therapy in controlling bacterial blight of leek, pending optimization of formulation and application methods.

  14. Effects of Acarbose Addition on Ruminal Bacterial Microbiota, Lipopolysaccharide Levels and Fermentation Characteristics

    Directory of Open Access Journals (Sweden)

    Yu-yang Yin

    2014-12-01

    Full Text Available This study investigated the effects of acarbose addition on changes in ruminal fermentation characteristics and the composition of the ruminal bacterial community in vitro using batch cultures. Rumen fluid was collected from the rumens of three cannulated Holstein cattle fed forage ad libitum that was supplemented with 6 kg of concentrate. The batch cultures consisted of 8 mL of strained rumen fluid in 40 mL of an anaerobic buffer containing 0.49 g of corn grain, 0.21 g of soybean meal, 0.15 g of alfalfa and 0.15g of Leymus chinensis. Acarbose was added to incubation bottles to achieve final concentrations of 0.1, 0.2, and 0.4 mg/mL. After incubation for 24 h, the addition of acarbose linearly decreased (p<0.05 the total gas production and the concentrations of acetate, propionate, butyrate, total volatile fatty acids, lactate and lipopolysaccharide (LPS. It also linearly increased (p<0.05 the ratio of acetate to propionate, the concentrations of isovalerate, valerate and ammonia-nitrogen and the pH value compared with the control. Pyrosequencing of the 16S rRNA gene showed that the addition of acarbose decreased (p<0.05 the proportion of Firmicutes and Proteobacteria and increased (p<0.05 the percentage of Bacteroidetes, Fibrobacteres, and Synergistetes compared with the control. A principal coordinates analysis plot based on unweighted UniFrac values and molecular variance analysis revealed that the structure of the ruminal bacterial communities in the control was different to that of the ruminal microbiota in the acarbose group. In conclusion, acarbose addition can affect the composition of the ruminal microbial community and may be potentially useful for preventing the occurrence of ruminal acidosis and the accumulation of LPS in the rumen.

  15. RT-PCR–DGGE Analysis to Elucidate the Dominant Bacterial Species of Industrial Spanish-Style Green Table Olive Fermentations

    OpenAIRE

    Antonio Benítez-Cabello; Joaquin Bautista-Gallego; Antonio Garrido-Fernández; Rantsiou, Kalliopi; Luca Cocolin; Rufino Jiménez-Díaz; Francisco Noé Arroyo López

    2016-01-01

    This paper describes the dominant bacterial species metabolically active through the industrial production of Spanish-style Manzanilla and Gordal olives. For this purpose, samples (brines and fruits) obtained at 0, 15, and 90 fermentation days were analyzed by a culture-independent approach to determine viable cells by reverse transcription of RNA and further PCR-DGGE analysis, detecting at least 7 different species. Vibrio vulnificus, Lactobacillus plantarum group, and Lactobacillus parafarr...

  16. Culture-independent bacterial community analysis of the salty-fermented fish paste products of Thailand and Laos

    OpenAIRE

    MARUI, Junichiro; BOULOM, Sayvisene; PANTHAVEE, Wanchai; MOMMA, Mari; KUSUMOTO, Ken-Ichi; NAKAHARA, Kazuhiko; SAITO, Masayoshi

    2015-01-01

    A bacterial community analysis, using a culture-independent method (polymerase chain reaction-denaturing gradient gel electrophoresis), detected 17 species of bacteria including species of the genera Tetragenococcus, Lactobacillus, Pediococcus, Weissella Halanaerobium, Clostridium, and Sphingomonas in a traditional salty-fermented fish paste known as pla-ra or pa-daek in Thailand and Laos, which is used as a storage-stable multi-purpose seasoning. The representative genus of lactic acid bacte...

  17. RT-PCR–DGGE analysis to elucidate the dominant bacterial species of industrial Spanish-style green table olive fermentations

    Directory of Open Access Journals (Sweden)

    Antonio Benítez-Cabello

    2016-08-01

    Full Text Available This paper describes the dominant bacterial species metabolically active through the industrial production of Spanish-style Manzanilla and Gordal olives. For this purpose, samples (brines and fruits obtained at 0, 15 and 90 fermentation days were analysed by a culture-independent approach to determine viable cells by reverse transcription of RNA and further PCR-DGGE analysis, detecting at least 7 different species. Vibrio vulnificus, Lactobacillus plantarum group, and Lactobacillus parafarraginis were present in samples from both cultivars; Lactobacillus sanfranciscensis and Halolactobacillus halophilus were detected only in Gordal samples, while Staphylococcus sp. was exclusively found at the onset of Manzanilla fermentations. Physicochemical data showed a typical fermentation profile while scanning electron microscopy confirmed the in situ biofilm formation on the olive epidermis. Different Bacillus, Staphylococcus and Enterococcus species, not detected during the fermentation process, were also found in the solid marine salt used by the industry for preparation of brines. Elucidation of these non-lactic acid bacteria species role during fermentation is then an appealingly challenge, particularly regarding safety issues.

  18. Fermentation parameters, quality and losses in sugarcane silages treated with chemical additives and a bacterial inoculant

    Directory of Open Access Journals (Sweden)

    André de Faria Pedroso

    2011-11-01

    Full Text Available The objective of this trial was to evaluate chemical additives and a bacterial inoculant on the inhibition of alcoholic fermentation and reduction of losses in sugarcane silages. Treatments were (doses on a fresh forage basis: without additive (control; urea (10 g/kg; urea (5 g/kg + sodium benzoate (0.5 g/kg; sodium benzoate (1 g/kg; urea + ammonium sulfate in a 9:1 relation (10 g/kg; Lactobacillus buchneri (5 × 10(4 cfu/g. Silages were produced in 10.16- × 30-cm PVC tubes, provided with tight lids adapted with Bunsen valves for gas losses quantification. Minisilos were opened 139 days after ensiling. Ethanol content (227 g/kg dry matter - DM and total DM loss (30% were high in the control silage. All additives, except benzoate, decreased ethanol concentration in silages. Inoculation with L. buchneri increased acetic acid content in the silage, resulting in a 41% reduction in ethanol content and the lowest gas loss among treatments (15.2%. There was synergistic effect between additives for the combined use of urea and benzoate. Silage treated with urea + ammonium sulfate has higher content of total digestible nutrients than the silage treated with urea exclusively.

  19. Quality and characteristics of fermented ginseng seed oil based on bacterial strain and extraction method.

    Science.gov (United States)

    Lee, Myung-Hee; Rhee, Young-Kyoung; Choi, Sang-Yoon; Cho, Chang-Won; Hong, Hee-Do; Kim, Kyung-Tack

    2017-07-01

    In this study, the fermentation of ginseng seeds was hypothesized to produce useful physiologically-active substances, similar to that observed for fermented ginseng root. Ginseng seed was fermented using Bacillus, Pediococcus, and Lactobacillus strains to extract ginseng seed oil, and the extraction yield, color, and quantity of phenolic compounds, fatty acids, and phytosterol were then analyzed. The ginseng seed was fermented inoculating 1% of each strain on sterilized ginseng seeds and incubating the seeds at 30°C for 24 h. Oil was extracted from the fermented ginseng seeds using compression extraction, solvent extraction, and supercritical fluid extraction. The color of the fermented ginseng seed oil did not differ greatly according to the fermentation or extraction method. The highest phenolic compound content recovered with the use of supercritical fluid extraction combined with fermentation using the Bacillus subtilis Korea Food Research Institute (KFRI) 1127 strain. The fatty acid composition did not differ greatly according to fermentation strain and extraction method. The phytosterol content of ginseng seed oil fermented with Bacillus subtilis KFRI 1127 and extracted using the supercritical fluid method was highest at 983.58 mg/100 g. Therefore, our results suggested that the ginseng seed oil fermented with Bacillus subtilis KFRI 1127 and extracted using the supercritical fluid method can yield a higher content of bioactive ingredients, such as phenolics, and phytosterols, without impacting the color or fatty acid composition of the product.

  20. Antibiotic penetration and bacterial killing in a Pseudomonas aeruginosa biofilm model

    DEFF Research Database (Denmark)

    Cao, Bao; Christophersen, Lars; Thomsen, Kim

    2015-01-01

    OBJECTIVES: Treating biofilm infections successfully is a challenge. We hypothesized that biofilms may be considered as independent compartments with particular pharmacokinetics. We therefore studied the pharmacokinetics and pharmacodynamics of tobramycin in a seaweed alginate-embedded biofilm...... model. METHODS: Seaweed alginate beads containing Pseudomonas aeruginosa were cultured in LB medium, sampled at day 1, 3, 5 or 7 and examined for the effect of treatment with tobramycin for 30 min. Treated beads were homogenized and the number of cfu was determined. The antibiotic concentration...

  1. Effects due to rhizospheric soil application of an antagonistic bacterial endophyte on native bacterial community and its survival in soil: A case study with Pseudomonas aeruginosa from banana

    Directory of Open Access Journals (Sweden)

    Pious eThomas

    2016-04-01

    Full Text Available Effective translation of research findings from laboratory to agricultural fields is essential for the success of biocontrol or growth promotion trials employing beneficial microorganisms. The rhizosphere is to be viewed holistically as a dynamic ecological niche comprising of diverse microorganisms including competitors and noxious antagonists to the bio-inoculant. This study was undertaken to assess the effects due to the soil application of an endophytic bacterium with multiple pathogen antagonistic potential on native bacterial community and its sustenance in agricultural soil. Pseudomonas aeruginosa was employed as a model system considering its frequent isolation as an endophyte, wide antagonistic effects reported against different phytopathogens and soil pests, and that the species is a known human pathogen which makes its usage in agriculture precarious. Employing the strain ‘GNS.13.2a’ from banana, its survival in field soil and the effects upon soil inoculation were investigated by monitoring total culturable bacterial fraction as the representative indicator of soil microbial community. Serial dilution plating of uninoculated control versus P. aeruginosa inoculated soil from banana rhizosphere indicated a significant reduction in native bacterial cfu soon after inoculation compared with control soil as assessed on cetrimide- nalidixic acid selective medium against nutrient agar. Sampling on day-4 showed a significant reduction in P. aeruginosa cfu in inoculated soil and a continuous dip thereafter registering >99% reduction within one week while the native bacterial population resurged with cfu restoration on par with control. This was validated in contained trials with banana plants. Conversely, P. aeruginosa showed static cfu or proliferation in axenic-soil. Lateral introduction of soil microbiome in P. aeruginosa established soil under axenic conditions or its co-incubation with soil microbiota in suspension indicated

  2. Label-free molecular imaging of bacterial communities of the opportunistic pathogen Pseudomonas aeruginosa

    Science.gov (United States)

    Baig, Nameera; Polisetti, Sneha; Morales-Soto, Nydia; Dunham, Sage J. B.; Sweedler, Jonathan V.; Shrout, Joshua D.; Bohn, Paul W.

    2016-09-01

    Biofilms, such as those formed by the opportunistic human pathogen Pseudomonas aeruginosa are complex, matrix enclosed, and surface-associated communities of cells. Bacteria that are part of a biofilm community are much more resistant to antibiotics and the host immune response than their free-floating counterparts. P. aeruginosa biofilms are associated with persistent and chronic infections in diseases such as cystic fibrosis and HIV-AIDS. P. aeruginosa synthesizes and secretes signaling molecules such as the Pseudomonas quinolone signal (PQS) which are implicated in quorum sensing (QS), where bacteria regulate gene expression based on population density. Processes such as biofilms formation and virulence are regulated by QS. This manuscript describes the powerful molecular imaging capabilities of confocal Raman microscopy (CRM) and surface enhanced Raman spectroscopy (SERS) in conjunction with multivariate statistical tools such as principal component analysis (PCA) for studying the spatiotemporal distribution of signaling molecules, secondary metabolites and virulence factors in biofilm communities of P. aeruginosa. Our observations reveal that the laboratory strain PAO1C synthesizes and secretes 2-alkyl-4-hydroxyquinoline N-oxides and 2-alkyl-4-hydroxyquinolones in high abundance, while the isogenic acyl homoserine lactone QS-deficient mutant (ΔlasIΔrhlI) strain produces predominantly 2-alkyl-quinolones during biofilm formation. This study underscores the use of CRM, along with traditional biological tools such as genetics, for studying the behavior of microbial communities at the molecular level.

  3. Applying meta-pathway analyses through metagenomics to identify the functional properties of the major bacterial communities of a single spontaneous cocoa bean fermentation process sample.

    Science.gov (United States)

    Illeghems, Koen; Weckx, Stefan; De Vuyst, Luc

    2015-09-01

    A high-resolution functional metagenomic analysis of a representative single sample of a Brazilian spontaneous cocoa bean fermentation process was carried out to gain insight into its bacterial community functioning. By reconstruction of microbial meta-pathways based on metagenomic data, the current knowledge about the metabolic capabilities of bacterial members involved in the cocoa bean fermentation ecosystem was extended. Functional meta-pathway analysis revealed the distribution of the metabolic pathways between the bacterial members involved. The metabolic capabilities of the lactic acid bacteria present were most associated with the heterolactic fermentation and citrate assimilation pathways. The role of Enterobacteriaceae in the conversion of substrates was shown through the use of the mixed-acid fermentation and methylglyoxal detoxification pathways. Furthermore, several other potential functional roles for Enterobacteriaceae were indicated, such as pectinolysis and citrate assimilation. Concerning acetic acid bacteria, metabolic pathways were partially reconstructed, in particular those related to responses toward stress, explaining their metabolic activities during cocoa bean fermentation processes. Further, the in-depth metagenomic analysis unveiled functionalities involved in bacterial competitiveness, such as the occurrence of CRISPRs and potential bacteriocin production. Finally, comparative analysis of the metagenomic data with bacterial genomes of cocoa bean fermentation isolates revealed the applicability of the selected strains as functional starter cultures. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Selective labelling and eradication of antibiotic-tolerant bacterial populations in Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Chua, Song Lin; Yam, Joey Kuok Hoong; Hao, Piliang

    2016-01-01

    Drug resistance and tolerance greatly diminish the therapeutic potential of antibiotics against pathogens. Antibiotic tolerance by bacterial biofilms often leads to persistent infections, but its mechanisms are unclear. Here we use a proteomics approach, pulsed stable isotope labelling with amino...... research avenues for designing more efficient treatments against biofilm-associated infections....... development. The macrolide erythromycin, which has been previously shown to inhibit the motility and QS of P. aeruginosa, boosts biofilm eradication by colistin. Our work provides insights on the mechanisms underlying the formation of antibiotic-tolerant populations in bacterial biofilms and indicates...

  5. Involvement of bacterial migration in the development of complex multicellular structures in Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Klausen, Mikkel; Aaes-Jorgensen, A.; Molin, Søren

    2003-01-01

    development, we have performed an investigation with time-lapse confocal laser scanning microscopy of biofilms formed by various combinations of colour-coded P. aeruginosa wild type and motility mutants. We show that mushroom-shaped multicellular structures in P. aeruginosa biofilms can form in a sequential...... process involving a non-motile bacterial subpopulation and a migrating bacterial subpopulation. The non-motile bacteria form the mushroom stalks by growth in certain foci of the biofilm. The migrating bacteria form the mushroom caps by climbing the stalks and aggregating on the tops in a process which...

  6. One-step purification and characterization of alginate lyase from a clinical Pseudomonas aeruginosa with destructive activity on bacterial biofilm

    Directory of Open Access Journals (Sweden)

    Parinaz Ghadam

    2017-05-01

    Full Text Available Objective(s: Pseudomonas aeruginosais a Gram-negative and aerobic rod bacterium that displays mucoid and non-mucoid phenotype. Mucoid strains secrete alginate, which is the main agent of biofilms in chronic P. aeruginosa infections, show high resistance to antibiotics; consequently, the biological disruption of mucoid P. aeruginosa biofilms is an attractive area of study for researchers. Alginate lyase gene (algl is a member of alginate producing operon which by glycosidase activity produces primer for other enzymes in this cluster. Also this activity can destroy the extracellular alginate; therefore this enzyme participates in alginate production and destruction pathway. Alginate lyase causes detachment of a biofilm by reducing its adhesion to the surfaces, and increases phagocytosis and antibiotic susceptibility. In this study, alginate lyase was purified in just one step and its properties were investigated. Materials and Methods: The purification was done by affinity chromatography, analysed by SDS-PAGE, and its effect on P. aeruginosa biofilms was surveyed by micro titer plate assay and SEM. The substrate specificity of the enzyme was determined by PCR. Results: Alginate lyase from isolate 48 was purified in one step. It is more thermally resistant than alginate lyase from Pseudomonas aeruginosa PAO1 and poly M, poly G and poly MG alginate were the substrate of this enzyme. Moreover, it has an eradication effect on biofilms from P. aeruginosa 48 and PAO1. Conclusion: In this study an alginate lyase with many characteristics suitable in medicine such as thermal stability, effective on poly M alginate, and bacterial biofilm destructive was introduced and purified.

  7. Target-based resistance in Pseudomonas aeruginosa and Escherichia coli to NBTI 5463, a novel bacterial type II topoisomerase inhibitor.

    Science.gov (United States)

    Nayar, Asha S; Dougherty, Thomas J; Reck, Folkert; Thresher, Jason; Gao, Ning; Shapiro, Adam B; Ehmann, David E

    2015-01-01

    In a previous report (T. J. Dougherty, A. Nayar, J. V. Newman, S. Hopkins, G. G. Stone, M. Johnstone, A. B. Shapiro, M. Cronin, F. Reck, and D. E. Ehmann, Antimicrob Agents Chemother 58:2657-2664, 2014), a novel bacterial type II topoisomerase inhibitor, NBTI 5463, with activity against Gram-negative pathogens was described. First-step resistance mutations in Pseudomonas aeruginosa arose exclusively in the nfxB gene, a regulator of the MexCD-OprJ efflux pump system. The present report describes further resistance studies with NBTI 5463 in both Pseudomonas aeruginosa and Escherichia coli. Second-step mutations in P. aeruginosa arose at aspartate 82 of the gyrase A subunit and led to 4- to 8-fold increases in the MIC over those seen in the parental strain with a first-step nfxB efflux mutation. A third-step mutant showed additional GyrA changes, with no changes in topoisomerase IV. Despite repeated efforts, resistance mutations could not be selected in E. coli. Genetic introduction of the Asp82 mutations observed in P. aeruginosa did not significantly increase the NBTI MIC in E. coli. However, with the aspartate 82 mutation present, it was possible to select second-step mutations in topoisomerase IV that did lead to MIC increases of 16- and 128-fold. As with the gyrase aspartate 82 mutation, the mutations in topoisomerase IV did not by themselves raise the NBTI MIC in E. coli. Only the presence of mutations in both targets of E. coli led to an increase in NBTI MIC values. This represents a demonstration of the value of balanced dual-target activity in mitigating resistance development. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  8. Structural and Molecular Mechanism of CdpR Involved in Quorum-Sensing and Bacterial Virulence in Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Jingru Zhao

    2016-04-01

    Full Text Available Although quorum-sensing (QS systems are important regulators of virulence gene expression in the opportunistic human pathogen Pseudomonas aeruginosa, their detailed regulatory mechanisms have not been fully characterized. Here, we show that deletion of PA2588 resulted in increased production of pyocyanin and biofilm, as well as enhanced pathogenicity in a mouse model. To gain insights into the function of PA2588, we performed a ChIP-seq assay and identified 28 targets of PA2588, including the intergenic region between PA2588 and pqsH, which encodes the key synthase of Pseudomonas quinolone signal (PQS. Though the C-terminal domain was similar to DNA-binding regions of other AraC family members, structural studies revealed that PA2588 has a novel fold at the N-terminal region (NTR, and its C-terminal HTH (helix-turn-helix domain is also unique in DNA recognition. We also demonstrated that the adaptor protein ClpS, an essential regulator of ATP-dependent protease ClpAP, directly interacted with PA2588 before delivering CdpR to ClpAP for degradation. We named PA2588 as CdpR (ClpAP-degradation and pathogenicity Regulator. Moreover, deletion of clpP or clpS/clpA promotes bacterial survival in a mouse model of acute pneumonia infection. Taken together, this study uncovered that CdpR is an important QS regulator, which can interact with the ClpAS-P system to regulate the expression of virulence factors and pathogenicity.

  9. Pseudomonas syringae pv. actinidiae from recent outbreaks of kiwifruit bacterial canker belong to different clones that originated in China.

    Directory of Open Access Journals (Sweden)

    Margi I Butler

    Full Text Available A recently emerged plant disease, bacterial canker of kiwifruit (Actinidia deliciosa and A. chinensis, is caused by Pseudomonas syringae pv. actinidiae (PSA. The disease was first reported in China and Japan in the 1980s. A severe outbreak of PSA began in Italy in 2008 and has spread to other European countries. PSA was found in both New Zealand and Chile in 2010. To study the evolution of the pathogen and analyse the transmission of PSA between countries, genomes of strains from China and Japan (where the genus Actinidia is endemic, Italy, New Zealand and Chile were sequenced. The genomes of PSA strains are very similar. However, all strains from New Zealand share several single nucleotide polymorphisms (SNPs that distinguish them from all other PSA strains. Similarly, all the PSA strains from the 2008 Italian outbreak form a distinct clonal group and those from Chile form a third group. In addition to the rare SNPs present in the core genomes, there is abundant genetic diversity in a genomic island that is part of the accessory genome. The island from several Chinese strains is almost identical to the island present in the New Zealand strains. The island from a different Chinese strain is identical to the island present in the strains from the recent Italian outbreak. The Chilean strains of PSA carry a third variant of this island. These genomic islands are integrative conjugative elements (ICEs. Sequencing of these ICEs provides evidence of three recent horizontal transmissions of ICE from other strains of Pseudomonas syringae to PSA. The analyses of the core genome SNPs and the ICEs, combined with disease history, all support the hypothesis of an independent Chinese origin for both the Italian and the New Zealand outbreaks and suggest the Chilean strains also originate from China.

  10. Pseudomonas syringae pv. actinidiae from recent outbreaks of kiwifruit bacterial canker belong to different clones that originated in China.

    Science.gov (United States)

    Butler, Margi I; Stockwell, Peter A; Black, Michael A; Day, Robert C; Lamont, Iain L; Poulter, Russell T M

    2013-01-01

    A recently emerged plant disease, bacterial canker of kiwifruit (Actinidia deliciosa and A. chinensis), is caused by Pseudomonas syringae pv. actinidiae (PSA). The disease was first reported in China and Japan in the 1980s. A severe outbreak of PSA began in Italy in 2008 and has spread to other European countries. PSA was found in both New Zealand and Chile in 2010. To study the evolution of the pathogen and analyse the transmission of PSA between countries, genomes of strains from China and Japan (where the genus Actinidia is endemic), Italy, New Zealand and Chile were sequenced. The genomes of PSA strains are very similar. However, all strains from New Zealand share several single nucleotide polymorphisms (SNPs) that distinguish them from all other PSA strains. Similarly, all the PSA strains from the 2008 Italian outbreak form a distinct clonal group and those from Chile form a third group. In addition to the rare SNPs present in the core genomes, there is abundant genetic diversity in a genomic island that is part of the accessory genome. The island from several Chinese strains is almost identical to the island present in the New Zealand strains. The island from a different Chinese strain is identical to the island present in the strains from the recent Italian outbreak. The Chilean strains of PSA carry a third variant of this island. These genomic islands are integrative conjugative elements (ICEs). Sequencing of these ICEs provides evidence of three recent horizontal transmissions of ICE from other strains of Pseudomonas syringae to PSA. The analyses of the core genome SNPs and the ICEs, combined with disease history, all support the hypothesis of an independent Chinese origin for both the Italian and the New Zealand outbreaks and suggest the Chilean strains also originate from China.

  11. Monitoring the bacterial population dynamics during the ripening of Galician chorizo, a traditional dry fermented Spanish sausage.

    Science.gov (United States)

    Fonseca, Sonia; Cachaldora, Aida; Gómez, María; Franco, Inmaculada; Carballo, Javier

    2013-02-01

    The dynamics of the bacterial population throughout the ripening of Galician chorizo, a traditional dry fermented sausage produced in the north-west of Spain, were investigated by using classical and molecular approaches. Fermented sausages are certainly complex matrices with PCR inhibitors and background microbiota. Therefore, two different DNA preparation methods were performed to elaborate each standard curve and no significant differences were found, showing a very good correlation between both methods (R(2)>0.994). The combination of the results obtained from microbial counts, species and genus-specific PCR as well as real-time quantitative PCR (qPCR) allowed the identification for the dominant bacterial species and the study of the variation in the community composition over the ripening period. According to the data obtained both by identification of plate isolates and by real-time PCR, the dominant species among staphylococci and lactobacilli were Staphylococcus equorum and Lactobacillus sakei, respectively. However, only real-time PCR assay showed enough sensitivity to detect and quantify staphylococci in meat batter before stuffing, showing values of 5.28logCFU/g when quantifying Staphylococcus spp. and 2.87logCFU/g when quantifying S. equorum. In conclusion, real-time PCR was shown to be an efficient tool for the study of the complex associations developed in meat fermentations and for the characterization of dominant populations. Copyright © 2012. Published by Elsevier Ltd.

  12. Effect of Single Bacterial Starter Culture on Odour Reduction During Controlled Fermentation of Cassava Tubers for Foofoo Production

    Directory of Open Access Journals (Sweden)

    Henshaw, E. E.

    2010-01-01

    Full Text Available Effects of single bacterial starter culture on odour reduction during controlled fermentation of cassava tubers for foofoo production were investigated. Pure cultures were used to ferment cassava tubers in water for 96 h. The cultures used include Bacillus subtilis, Klebsiela sp., Lactobacillus plantarum and Leuconostoc mesenteroides. L. plantarum exhibited the highest acid producing ability, decreasing the pH of the Cassava tubers from 6.2 to 3.68 with a corresponding increase in total titratable acidity (TTA from 0.082% to 0.290% during the 96 h fermentation period. The effected changes in pH and TTA by other organisms ranged respectively from 4.88 and 0.135% for Klebsiella sp., 4.68 and 0.136% for L. mesenteroides to 4.90 and 0.139% for B. subtilis with in the period. All the cultures were found to contribute in varying degree to odour reduction in fermented cassava; B. subtilis effected the highest odour reduction followed by L. plantarum.

  13. Analyses of bacterial communities in meju, a Korean traditional fermented soybean bricks, by cultivation-based and pyrosequencing methods.

    Science.gov (United States)

    Kim, Yi-Seul; Kim, Min-Cheol; Kwon, Soon-Wo; Kim, Soo-Jin; Park, In-Cheol; Ka, Jong-Ok; Weon, Hang-Yeon

    2011-06-01

    Despite the importance of meju as a raw material used to make Korean soy sauce (ganjang) and soybean paste (doenjang), little is known about the bacterial diversity of Korean meju. In this study, the bacterial communities in meju were examined using both culture-dependent and independent methods in order to evaluate the diversity of the bacterial population. Analyses of the 16S rRNA gene sequences of the bacterial strains isolated from meju samples showed that the dominant species were related to members of the genera Bacillus, Enterococcus, and Pediococcus. The community DNAs extracted from nine different meju samples were analyzed by barcoded pyrosequencing method targeting of the V1 to V3 hypervariable regions of the 16S rRNA gene. In total, 132,374 sequences, with an average read length of 468 bp, were assigned to several phyla, with Firmicutes (93.6%) representing the predominant phylum, followed by Proteobacteria (4.5%) and Bacteroidetes (0.8%). Other phyla accounted for less than 1% of the total bacterial sequences. Most of the Firmicutes were Bacillus and lactic acid bacteria, mainly represented by members of the genera Enterococcus, Lactococcus, and Leuconostoc, whose ratio varied among different samples. In conclusion, this study indicated that the bacterial communities in meju were very diverse and a complex microbial consortium containing various microorganisms got involved in meju fermentation than we expected before.

  14. Bacterial community dynamics, lactic acid bacteria species diversity and metabolite kinetics of traditional Romanian vegetable fermentations.

    Science.gov (United States)

    Wouters, Dorrit; Grosu-Tudor, Silvia; Zamfir, Medana; De Vuyst, Luc

    2013-03-15

    Artisanal vegetable fermentations are very popular in Eastern European countries. Fresh vegetables undergo a spontaneous fermentation in the presence of salt, which is mainly carried out by lactic acid bacteria (LAB). Culture-dependent and culture-independent analyses of end-samples of various spontaneous vegetable fermentations carried out in houses of the Chiodju region (central Romania) revealed Lactobacillus plantarum and Lactobacillus brevis as the most frequently isolated LAB species. Leuconostoc mesenteroides and Leuconostoc citreum were also found. Furthermore, the community dynamics of spontaneous cauliflower and mixed-vegetable (green tomatoes, carrots and cauliflower) fermentations revealed three steps: an initial phase characterised by the presence of Enterobacteriaceae and a wide LAB species diversity, encompassing Weissella species; a second phase from day 3 onwards wherein L. citreum and Lb. brevis occurred; and a final phase characterised by the prevalence of Lb. brevis and Lb. plantarum. Metabolite target analysis revealed that glucose and fructose were mostly depleted at the end of fermentation. The main products of carbohydrate metabolism were lactic acid, acetic acid, ethanol and small amounts of mannitol, indicating heterolactate fermentation. Given their prevalence at the end of vegetable fermentations, Lb. brevis and Lb. plantarum appear to be good candidate starter cultures for controlled vegetable fermentation processes. © 2012 Society of Chemical Industry.

  15. Resolving Bacterial Contamination of Fuel Ethanol Fermentations with Beneficial Bacteria – an Alternative to Antibiotic Treatment

    Science.gov (United States)

    Fuel ethanol fermentations are not performed under aseptic conditions and microbial contamination reduces yields and can lead to costly “stuck fermentations.” Antibiotics are commonly used to combat contaminants, but these may persist in the distillers grains co-product. Among contaminants, it is kn...

  16. Serotonin Activates Bacterial Quorum Sensing and Enhances the Virulence of Pseudomonas aeruginosa in the Host

    Directory of Open Access Journals (Sweden)

    Leslie D. Knecht

    2016-07-01

    Full Text Available Bacteria in humans play an important role in health and disease. Considerable emphasis has been placed in understanding the role of bacteria in host-microbiome interkingdom communication. Here we show that serotonin, responsible for mood in the brain and motility in the gut, can also act as a bacterial signaling molecule for pathogenic bacteria. Specifically, we found that serotonin acts as an interkingdom signaling molecule via quorum sensing and that it stimulates the production of bacterial virulence factors and increases biofilm formation in vitro and in vivo in a novel mouse infection model. This discovery points out at roles of serotonin both in bacteria and humans, and at phenotypic implications not only manifested in mood behavior but also in infection processes in the host. Thus, regulating serotonin concentrations in the gut may provide with paradigm shifting therapeutic approaches.

  17. Serotonin Activates Bacterial Quorum Sensing and Enhances the Virulence of Pseudomonas aeruginosa in the Host.

    Science.gov (United States)

    Knecht, Leslie D; O'Connor, Gregory; Mittal, Rahul; Liu, Xue Z; Daftarian, Pirouz; Deo, Sapna K; Daunert, Sylvia

    2016-07-01

    Bacteria in humans play an important role in health and disease. Considerable emphasis has been placed in understanding the role of bacteria in host-microbiome interkingdom communication. Here we show that serotonin, responsible for mood in the brain and motility in the gut, can also act as a bacterial signaling molecule for pathogenic bacteria. Specifically, we found that serotonin acts as an interkingdom signaling molecule via quorum sensing and that it stimulates the production of bacterial virulence factors and increases biofilm formation in vitro and in vivo in a novel mouse infection model. This discovery points out at roles of serotonin both in bacteria and humans, and at phenotypic implications not only manifested in mood behavior but also in infection processes in the host. Thus, regulating serotonin concentrations in the gut may provide with paradigm shifting therapeutic approaches. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  18. Lactic Acid Bacterial Starter Culture with Antioxidant and γ-Aminobutyric Acid Biosynthetic Activities Isolated from Flatfish-Sikhae Fermentation.

    Science.gov (United States)

    Won, Yeong Geol; Yu, Hyun-Hee; Chang, Young-Hyo; Hwang, Han-Joon

    2015-12-01

    The aim of this study is to select a lactic acid bacterial strain as a starter culture for flatfish-Sikhae fermentation and to evaluate its suitability for application in a food system. Four strains of lactic acid bacteria isolated from commercial flatfish-Sikhae were identified and selected as starter culture candidates through investigation of growth rates, salt tolerance, food safety, and functional properties such as antioxidative and antimicrobial activities. The fermentation properties of the starter candidates were also examined in food systems prepared with these strains (candidate batch) in comparison with a spontaneous fermentation process without starter culture (control batch) at 15°C. The results showed that the candidate YG331 batch had better fermentation properties such as viable cell count, pH, and acidity than the other experimental batches, including the control batch. The results are expressed according to selection criteria based on a preliminary sensory evaluation and physiochemical investigation. Also, only a small amount of histamine was detected with the candidate YG331 batch. The radical scavenging activity of the candidate batches was better compared with the control batch, and especially candidate YG331 batch showed the best radical scavenging activity. Also, we isolated another starter candidate (identified as Lactobacillus brevis PM03) with γ-aminobutyric acid (GABA)-producing activity from commercial flatfish-Sikhae products. The sensory scores of the candidate YG331 batch were better than those of the other experimental batches in terms of flavor, color, and overall acceptance. In this study, we established selection criteria for the lactic acid bacterial starter for the flatfish-Sikhae production and finally selected candidate YG331 as the most suitable starter.

  19. Permeabilization of biological and artificial membranes by a bacterial dirhamnolipid produced by Pseudomonas aeruginosa.

    Science.gov (United States)

    Sánchez, Marina; Aranda, Francisco J; Teruel, José A; Espuny, María J; Marqués, Ana; Manresa, Angeles; Ortiz, Antonio

    2010-01-15

    Pseudomonas aeruginosa, when cultured under the appropriate conditions, secretes rhamnolipids to the external medium. These glycolipids constitute one of the most interesting classes of biosurfactants so far. A dirhamnolipid fraction was isolated and purified from the crude biosurfactant, and its action on model and biological membranes was studied. Dirhamnolipid induced leakage of internal contents, as measured by the release of carboxyfluorescein, in phosphatidylcholine unilamellar vesicles, at concentrations below its CMC. Membrane solubilization was not observed within this concentration range. The presence of inverted cone-shaped lipids in the membrane, namely lysophosphatidylcholine, accelerated leakage, whereas cone-shaped lipids, like phosphatidylethanolamine, decreased leakage rate. Increasing concentrations of cholesterol protected the membrane against dirhamnolipid-induced leakage, which was totally abolished by the presence of 50 mol% of the sterol. Dirhamnolipid caused hemolysis of human erythrocytes through a lytic mechanism, as shown by the similar rates of K(+) and hemoglobin leakage, and by the absence of effect of osmotic protectants. Scanning electron microscopy showed that the addition of the biosurfactant changed the usual disc shape of erythrocytes into that of spheroechinocytes. The results are discussed within the frame of the biological actions of dirhamnolipid, and the possible future applications of this biosurfactant.

  20. Strong incidence of Pseudomonas aeruginosa on bacterial rrs and ITS genetic structures of cystic fibrosis sputa.

    Science.gov (United States)

    Pages-Monteiro, Laurence; Marti, Romain; Commun, Carine; Alliot, Nolwenn; Bardel, Claire; Meugnier, Helene; Perouse-de-Montclos, Michele; Reix, Philippe; Durieu, Isabelle; Durupt, Stephane; Vandenesch, Francois; Freney, Jean; Cournoyer, Benoit; Doleans-Jordheim, Anne

    2017-01-01

    Cystic fibrosis (CF) lungs harbor a complex community of interacting microbes, including pathogens like Pseudomonas aeruginosa. Meta-taxogenomic analysis based on V5-V6 rrs PCR products of 52 P. aeruginosa-positive (Pp) and 52 P. aeruginosa-negative (Pn) pooled DNA extracts from CF sputa suggested positive associations between P. aeruginosa and Stenotrophomonas and Prevotella, but negative ones with Haemophilus, Neisseria and Burkholderia. Internal Transcribed Spacer analyses (RISA) from individual DNA extracts identified three significant genetic structures within the CF cohorts, and indicated an impact of P. aeruginosa. RISA clusters Ip and IIIp contained CF sputa with a P. aeruginosa prevalence above 93%, and of 24.2% in cluster IIp. Clusters Ip and IIIp showed lower RISA genetic diversity and richness than IIp. Highly similar cluster IIp RISA profiles were obtained from two patients harboring isolates of a same P. aeruginosa clone, suggesting convergent evolution in the structure of their microbiota. CF patients of cluster IIp had received significantly less antibiotics than patients of clusters Ip and IIIp but harbored the most resistant P. aeruginosa strains. Patients of cluster IIIp were older than those of Ip. The effects of P. aeruginosa on the RISA structures could not be fully dissociated from the above two confounding factors but several trends in these datasets support the conclusion of a strong incidence of P. aeruginosa on the genetic structure of CF lung microbiota.

  1. Identification of novel members of the bacterial azoreductase family in Pseudomonas aeruginosa.

    Science.gov (United States)

    Crescente, Vincenzo; Holland, Sinead M; Kashyap, Sapna; Polycarpou, Elena; Sim, Edith; Ryan, Ali

    2016-03-01

    Azoreductases are a family of diverse enzymes found in many pathogenic bacteria as well as distant homologues being present in eukarya. In addition to having azoreductase activity, these enzymes are also suggested to have NAD(P)H quinone oxidoreductase (NQO) activity which leads to a proposed role in plant pathogenesis. Azoreductases have also been suggested to play a role in the mammalian pathogenesis of Pseudomonas aeruginosa. In view of the importance of P. aeruginosa as a pathogen, we therefore characterized recombinant enzymes following expression of a group of putative azoreductase genes from P. aeruginosa expressed in Escherichia coli. The enzymes include members of the arsenic-resistance protein H (ArsH), tryptophan repressor-binding protein A (WrbA), modulator of drug activity B (MdaB) and YieF families. The ArsH, MdaB and YieF family members all show azoreductase and NQO activities. In contrast, WrbA is the first enzyme to show NQO activity but does not reduce any of the 11 azo compounds tested under a wide range of conditions. These studies will allow further investigation of the possible role of these enzymes in the pathogenesis of P. aeruginosa. © 2016 Authors; published by Portland Press Limited.

  2. Multimodal chemical imaging of molecular messengers in emerging Pseudomonas aeruginosa bacterial communities.

    Science.gov (United States)

    Baig, Nameera F; Dunham, Sage J B; Morales-Soto, Nydia; Shrout, Joshua D; Sweedler, Jonathan V; Bohn, Paul W

    2015-10-07

    Two label-free molecular imaging techniques, confocal Raman microscopy (CRM) and secondary ion mass spectrometry (SIMS), are combined for in situ characterization of the spatiotemporal distributions of quinolone metabolites and signaling molecules in communities of the pathogenic bacterium Pseudomonas aeruginosa. Dramatic molecular differences are observed between planktonic and biofilm modes of growth for these bacteria. We observe patterned aggregation and a high abundance of N-oxide quinolines in early biofilms and swarm zones of P. aeruginosa, while the concentrations of these secreted components in planktonic cells and agar plate colonies are below CRM and SIMS detection limits. CRM, in conjunction with principal component analysis (PCA) is used to distinguish between the two co-localized isomeric analyte pairs 4-hydroxy-2-heptylquinoline-N-oxide (HQNO)/2-heptyl-3-hydroxyquinolone (PQS) and 4-hydroxy-2-nonylquinoline-N-oxide (NQNO)/2-nonyl-hydroxyquinolone (C9-PQS) based on differences in their vibrational fingerprints, illustrating how the technique can be used to guide tandem-MS and tandem-MS imaging analysis. Because N-oxide quinolines are ubiquitous and expressed early in biofilms, these analytes may be fundamentally important for early biofilm formation and the growth and organization of P. aeruginosa microbial communities. This study underscores the advantages of using multimodal molecular imaging to study complex biological systems.

  3. Metformin prevents the effects of Pseudomonas aeruginosa on airway epithelial tight junctions and restricts hyperglycaemia-induced bacterial growth.

    Science.gov (United States)

    Patkee, Wishwanath R A; Carr, Georgina; Baker, Emma H; Baines, Deborah L; Garnett, James P

    2016-04-01

    Lung disease and elevation of blood glucose are associated with increased glucose concentration in the airway surface liquid (ASL). Raised ASL glucose is associated with increased susceptibility to infection by respiratory pathogens including Staphylococcus aureus and Pseudomonas aeruginosa. We have previously shown that the anti-diabetes drug, metformin, reduces glucose-induced S. aureus growth across in vitro airway epithelial cultures. The aim of this study was to investigate whether metformin has the potential to reduce glucose-induced P. aeruginosa infections across airway epithelial (Calu-3) cultures by limiting glucose permeability. We also explored the effect of P. aeruginosa and metformin on airway epithelial barrier function by investigating changes in tight junction protein abundance. Apical P. aeruginosa growth increased with basolateral glucose concentration, reduced transepithelial electrical resistance (TEER) and increased paracellular glucose flux. Metformin pre-treatment of the epithelium inhibited the glucose-induced growth of P. aeruginosa, increased TEER and decreased glucose flux. Similar effects on bacterial growth and TEER were observed with the AMP activated protein kinase agonist, 5-aminoimidazole-4-carboxamide ribonucleotide. Interestingly, metformin was able to prevent the P. aeruginosa-induced reduction in the abundance of tight junction proteins, claudin-1 and occludin. Our study highlights the potential of metformin to reduce hyperglycaemia-induced P. aeruginosa growth through airway epithelial tight junction modulation, and that claudin-1 and occludin could be important targets to regulate glucose permeability across airway epithelia and supress bacterial growth. Further investigation into the mechanisms regulating metformin and P. aeruginosa action on airway epithelial tight junctions could yield new therapeutic targets to prevent/suppress hyperglycaemia-induced respiratory infections, avoiding the use of antibiotics. © 2016 The

  4. Characterization of Novel Bacteriophages for Biocontrol of Bacterial Blight in Leek Caused by Pseudomonas syringae pv. porri.

    Science.gov (United States)

    Rombouts, Sofie; Volckaert, Anneleen; Venneman, Sofie; Declercq, Bart; Vandenheuvel, Dieter; Allonsius, Camille N; Van Malderghem, Cinzia; Jang, Ho B; Briers, Yves; Noben, Jean P; Klumpp, Jochen; Van Vaerenbergh, Johan; Maes, Martine; Lavigne, Rob

    2016-01-01

    Pseudomonas syringae pv. porri, the causative agent of bacterial blight in leek (Allium porrum), is increasingly frequent causing problems in leek cultivation. Because of the current lack of control measures, novel bacteriophages were isolated to control this pathogen using phage therapy. Five novel phages were isolated from infected fields in Flanders (vB_PsyM_KIL1, vB_PsyM_KIL2, vB_PsyM_KIL3, vB_PsyM_KIL4, and vB_PsyM_KIL5), and were complemented with one selected host range mutant phage (vB_PsyM_KIL3b). Genome analysis of the phages revealed genome sizes between 90 and 94 kb and an average GC-content of 44.8%. Phylogenomic networking classified them into a novel clade, named the "KIL-like viruses," related to the Felixounalikevirus genus, together with phage phiPsa374 from P. syringae pv. actinidiae. In vitro characterization demonstrated the stability and lytic potential of these phages. Host range analysis confirmed heterogeneity within P. syringae pv. porri, leading to the development of a phage cocktail with a range that covers the entire set of 41 strains tested. Specific bio-assays demonstrated the in planta efficacy of phages vB_PsyM_KIL1, vB_PsyM_KIL2, vB_PsyM_KIL3, and vB_PsyM_KIL3b. In addition, two parallel field trial experiments on three locations using a phage cocktail of the six phages showed variable results. In one trial, symptom development was attenuated. These data suggest some potential for phage therapy in controlling bacterial blight of leek, pending optimization of formulation and application methods.

  5. Allelic variation in two distinct Pseudomonas syringae flagellin epitopes modulates the strength of plant immune responses but not bacterial motility

    Science.gov (United States)

    Clarke, Christopher R.; Chinchilla, Delphine; Hind, Sarah R.; Taguchi, Fumiko; Miki, Ryuji; Ichinose, Yuki; Martin, Gregory B.; Leman, Scotland; Felix, Georg; Vinatzer, Boris A.

    2013-01-01

    Summary The bacterial flagellin (FliC) epitopes flg22 and flgII-28 are microbe-associated molecular patterns (MAMPs). While flg22 is recognized by many plant species via the pattern recognition receptor FLS2, neither the flgII-28 receptor nor the extent of flgII-28 recognition by different plant families is known.Here we tested the significance of flgII-28 as a MAMP and the importance of allelic diversity in flg22 and flgII-28 in plant–pathogen interactions using purified peptides and a Pseudomonas syringae ΔfliC mutant complemented with different fliC alleles.Plant genotype and allelic diversity in flg22 and flgII-28 were found to significantly affect the plant immune response but not bacterial motility. Recognition of flgII-28 is restricted to a number of Solanaceous species. While the flgII-28 peptide does not trigger any immune response in Arabidopsis, mutations in both flg22 and flgII-28 have FLS2-dependent effects on virulence. However, expression of a tomato allele of FLS2 does not confer to Nicotiana benthamiana the ability to detect flgII-28 and tomato plants silenced for FLS2 are not altered in flgII-28 recognition.Therefore, MAMP diversification is an effective pathogen virulence strategy and flgII-28 appears to be perceived by a yet unidentified receptor in the Solanaceae although it has an FLS2-dependent virulence effect in Arabidopsis. PMID:23865782

  6. Pseudomonas fluorescens filamentous hemagglutinin, an iron-regulated protein, is an important virulence factor that modulates bacterial pathogenicity

    Directory of Open Access Journals (Sweden)

    Yuan-yuan Sun

    2016-08-01

    Full Text Available Pseudomonas fluorescens is a common bacterial pathogen to a wide range of aquaculture animals including various species of fish. In this study, we employed proteomic analysis and identified filamentous hemagglutinin (FHA as an iron-responsive protein secreted by TSS, a pathogenic P. fluorescens isolate. In vitro study showed that compared to the wild type, the fha mutant TSSfha (i exhibited a largely similar vegetative growth profile but significantly retarded in the ability of biofilm growth and producing extracellular matrix, (ii displayed no apparent flagella and motility, (iii was defective in the attachment to host cells and unable to form self-aggregation, (iv displayed markedly reduced capacity of hemagglutination and surviving in host serum. In vivo infection analysis revealed that TSSfha was significantly attenuated in the ability of dissemination in fish tissues and inducing host mortality, and that antibody blocking of the natural FHA produced by the wild type TSS impaired the infectivity of the pathogen. Furthermore, when introduced into turbot as a subunit vaccine, recombinant FHA elicited a significant protection against lethal TSS challenge. Taken together, these results indicate for the first time that P. fluorescens FHA is a key virulence factor essential to multiple biological processes associated with pathogenicity.

  7. External Bacterial Flora and Antimicrobial Susceptibility Patterns of Staphylococcus spp. and Pseudomonas spp. Isolated from Two Household Cockroaches, Blattella germanica and Blatta orientalis.

    Science.gov (United States)

    Menasria, Taha; Tine, Samir; Mahcene, Djaouida; Benammar, Leyla; Megri, Rochdi; Boukoucha, Mourad; Debabza, Manel

    2015-04-01

    A study was performed to estimate the prevalence of the external bacterial flora of two domestic cockroaches (Blattella germanica and Blatta orientalis) collected from households in Tebessa (northeast Algeria). Three major bacterial groups were cultured (total aerobic, enterobacteria, and staphylococci) from 14 specimens of cockroaches, and antibiotic susceptibility was tested for both Staphylococcus and Pseudomonas isolates. Culturing showed that the total bacterial load of cockroaches from different households were comparable (P<0.001) and enterobacteria were the predominant colonizers of the insect surface, with a bacterial load of (2.1 × 10⁵ CFU/insect), whereas the staphylococci group was the minority. Twenty-eight bacterial species were isolated, and susceptibility patterns showed that most of the staphylococci isolates were highly susceptible to chloramphenicol, gentamycin, pristinamycin, ofloxacin, clindamycin, and vancomycin; however, Pseudomonas strains exhibited resistance to amoxicillin/clavulanic acid, imipenem, and the second-generation antibiotic cephalosporin cefuroxime. Copyright © 2015 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  8. Pre-adapting parasitic phages to a pathogen leads to increased pathogen clearance and lowered resistance evolution with Pseudomonas aeruginosacystic fibrosis bacterial isolates

    DEFF Research Database (Denmark)

    Friman, Ville-Petri; Soanes-Brown, Daniel; Sierocinski, Pawel

    2016-01-01

    determined if in vitro experimental coevolution can increase the efficiency of phage therapy by limiting the resistance evolution of intermittent and chronic cystic fibrosis Pseudomonas aeruginosa lung isolates to four different phages. We first pre-adapted all phage strains against all bacterial strains...... and then compared the efficacy of pre-adapted and non-adapted phages against ancestral bacterial strains. We found that evolved phages were more efficient in reducing bacterial densities than ancestral phages. This was primarily because only 50% of bacterial strains were able to evolve resistance to evolved phages......Recent years have seen renewed interest in phage therapy - the use of viruses to specifically kill disease-causing bacteria – because of the alarming rise in antibiotic resistance. However, a major limitation of phage therapy is the ease at with bacteria can evolve resistance to phages. Here we...

  9. Differential sensitivity of polyhydroxyalkanoate producing bacteria to fermentation inhibitors and comparison of polyhydroxybutyrate production from Burkholderia cepacia and Pseudomonas pseudoflava

    Science.gov (United States)

    Diane Dietrich; Barbara Illman; Casey Crooks

    2013-01-01

    The aim of this study is determine the relative sensitivity of a panel of seven polyhydroxyalkanoate producing bacteria to a panel of seven lignocellulosic-derived fermentation inhibitors representing aliphatic acids, furans and phenolics. A further aim was to measure the polyhydroxybutyrate production of select organisms on lignocellulosic-derived monosaccharides...

  10. Metatranscriptomic analysis of lactic acid bacterial gene expression during kimchi fermentation.

    Science.gov (United States)

    Jung, Ji Young; Lee, Se Hee; Jin, Hyun Mi; Hahn, Yoonsoo; Madsen, Eugene L; Jeon, Che Ok

    2013-05-15

    Barcode-based 16S rRNA gene pyrosequencing showed that the kimchi microbiome was dominated by six lactic acid bacteria (LAB), Leuconostoc (Lc.) mesenteroides, Lactobacillus (Lb.) sakei, Weissella (W.) koreensis, Lc. gelidum, Lc. carnosum, and Lc. gasicomitatum. Therefore, we used completed genome sequences of representatives of these bacteria to investigate metatranscriptomic gene-expression profiles during kimchi fermentation. Total mRNA was extracted from kimchi samples taken at five time points during a 29 day-fermentation. Nearly all (97.7%) of the metagenome sequences that were recruited on all LAB genomes of GenBank mapped onto the six LAB strains; this high coverage rate indicated that this approach for assessing processes carried out by the kimchi microbiome was valid. Expressed mRNA sequences (as cDNA) were determined using Illumina GA IIx. Assignment of mRNA sequences to metabolic genes using MG-RAST revealed the prevalence of carbohydrate metabolism and lactic acid fermentation. The mRNA sequencing reads were mapped onto genomes of the six LAB strains, which showed that Lc. mesenteroides was most active during the early-stage fermentation, whereas gene expression by Lb. sakei and W. koreensis was high during later stages. However, gene expression by Lb. sakei decreased rapidly at 25 days of fermentation, which was possibly caused by bacteriophage infection of the Lactobacillus species. Many genes related to carbohydrate transport and hydrolysis and lactate fermentation were actively expressed, which indicated typical heterolactic acid fermentation. Mannitol dehydrogenase-encoding genes (mdh) were identified from all Leuconostoc species and especially Lc. mesenteroides, which harbored three copies (two copies on chromosome and one copy on plasmid) of mdh with different expression patterns. These results contribute to knowledge of the active populations and gene expression in the LAB community responsible for an important fermentation process. Copyright

  11. Fermentation of cereals for reduction of bacterial contamination of weaning foods in Ghana.

    Science.gov (United States)

    Mensah, P P; Tomkins, A M; Drasar, B S; Harrison, T J

    1990-07-21

    Unfermented and fermented maize dough weaning foods prepared by mothers in a Ghanaian village were examined for gram-negative bacilli (GNB) immediately after preparation and during storage to assess the antimicrobial effect of fermentation. GNB were cultured from all samples of unfermented dough (51) and from 16 of 51 samples of fermented dough. The extent of contamination was significantly higher in the unfermented dough than in fermented dough (5.9 [SEM 0.1] vs 4.0 [0.4] log10 colony forming units/g). After 6 h and 12 h storage, a higher proportion of samples of porridge made from unfermented dough contained GNB than did those made with fermented dough (45/51 vs 22/55; 49/51 vs 20/51, respectively) and levels of GNB were significantly higher in the porridge made from unfermented dough after 6 h (4.2 [0.2] vs 3.8 [0.2]). Fermentation of maize dough is an effective method to reduce contamination of maize dough weaning foods with GNB.

  12. A simple one pot purification of bacterial amylase from fermented broth based on affinity toward starch-functionalized magnetic nanoparticle.

    Science.gov (United States)

    Paul, Tanima; Chatterjee, Saptarshi; Bandyopadhyay, Arghya; Chattopadhyay, Dwiptirtha; Basu, Semanti; Sarkar, Keka

    2015-08-18

    Surface-functionalized adsorbant particles in combination with magnetic separation techniques have received considerable attention in recent years. Selective manipulation on such magnetic nanoparticles permits separation with high affinity in the presence of other suspended solids. Amylase is used extensively in food and allied industries. Purification of amylase from bacterial sources is a matter of concern because most of the industrial need for amylase is met by microbial sources. Here we report a simple, cost-effective, one-pot purification technique for bacterial amylase directly from fermented broth of Bacillus megaterium utilizing starch-coated superparamagnetic iron oxide nanoparticles (SPION). SPION was prepared by co-precipitation method and then functionalized by starch coating. The synthesized nanoparticles were characterized by transmission electron microscopy (TEM), a superconducting quantum interference device (SQUID, zeta potential, and ultraviolet-visible (UV-vis) and Fourier-transform infrared (FTIR) spectroscopy. The starch-coated nanoparticles efficiently purified amylase from bacterial fermented broth with 93.22% recovery and 12.57-fold purification. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) revealed that the molecular mass of the purified amylase was 67 kD, and native gel showed the retention of amylase activity even after purification. Optimum pH and temperature of the purified amylase were 7 and 50°C, respectively, and it was stable over a range of 20°C to 50°C. Hence, an improved one-pot bacterial amylase purification method was developed using starch-coated SPION.

  13. Composition and Metabolic Activities of the Bacterial Community in Shrimp Sauce at the Flavor-Forming Stage of Fermentation As Revealed by Metatranscriptome and 16S rRNA Gene Sequencings.

    Science.gov (United States)

    Duan, Shan; Hu, Xiaoxi; Li, Mengru; Miao, Jianyin; Du, Jinghe; Wu, Rongli

    2016-03-30

    The bacterial community and the metabolic activities involved at the flavor-forming stage during the fermentation of shrimp sauce were investigated using metatranscriptome and 16S rRNA gene sequencings. Results showed that the abundance of Tetragenococcus was 95.1%. Tetragenococcus halophilus was identified in 520 of 588 transcripts annotated in the Nr database. Activation of the citrate cycle and oxidative phosphorylation, along with the absence of lactate dehydrogenase gene expression, in T. halophilus suggests that T. halophilus probably underwent aerobic metabolism during shrimp sauce fermentation. The metabolism of amino acids, production of peptidase, and degradation of limonene and pinene were very active in T. halophilus. Carnobacterium, Pseudomonas, Escherichia, Staphylococcus, Bacillus, and Clostridium were also metabolically active, although present in very small populations. Enterococcus, Abiotrophia, Streptococcus, and Lactobacillus were detected in metatranscriptome sequencing, but not in 16S rRNA gene sequencing. Many minor taxa showed no gene expression, suggesting that they were in dormant status.

  14. A survey of fermentation products and bacterial communities in corn silage produced in a bunker silo in China.

    Science.gov (United States)

    Wang, Chao; Han, Hongyan; Gu, Xueying; Yu, Zhu; Nishino, Naoki

    2014-01-01

    To evaluate the current practice of corn silage management in China, samples of bunker-made silage were collected from 14 farms within a 500-km radius of Beijing for the analysis of fermentation products and bacterial communities. Mean values for dry matter (DM) content were as low as 250 g/kg in both corn stover (St) and whole crop corn (Wc) silages, and pH values averaged 4.48 and 3.73, respectively. Only three of the 14 silages exhibited a lactic-to-acetic acid ratio > 1.0, indicating that the presence of acetic acid was predominant in fermentation. Although 1,2-propanediol content was marginal in most cases ( 25 g/kg DM. In contrast, 3 St silages had large amounts (> 10 g/kg DM) of butyric acid, and two of the three butyrate silages also had high concentrations of 1-propanol. Denaturing gradient gel electrophoresis analysis demonstrated that the bacterial community appeared similar in 10 out of the 14 silage samples. Bands indicating Lactobacillus buchneri, L. acetotolerans and Acetobacter pasteurianus were found in both the St and Wc silages, accounting for the high acetic acid content found across silage samples. © 2013 Japanese Society of Animal Science.

  15. Phylogenetic analysis of a spontaneous cocoa bean fermentation metagenome reveals new insights into its bacterial and fungal community diversity.

    Directory of Open Access Journals (Sweden)

    Koen Illeghems

    Full Text Available This is the first report on the phylogenetic analysis of the community diversity of a single spontaneous cocoa bean box fermentation sample through a metagenomic approach involving 454 pyrosequencing. Several sequence-based and composition-based taxonomic profiling tools were used and evaluated to avoid software-dependent results and their outcome was validated by comparison with previously obtained culture-dependent and culture-independent data. Overall, this approach revealed a wider bacterial (mainly γ-Proteobacteria and fungal diversity than previously found. Further, the use of a combination of different classification methods, in a software-independent way, helped to understand the actual composition of the microbial ecosystem under study. In addition, bacteriophage-related sequences were found. The bacterial diversity depended partially on the methods used, as composition-based methods predicted a wider diversity than sequence-based methods, and as classification methods based solely on phylogenetic marker genes predicted a more restricted diversity compared with methods that took all reads into account. The metagenomic sequencing analysis identified Hanseniaspora uvarum, Hanseniaspora opuntiae, Saccharomyces cerevisiae, Lactobacillus fermentum, and Acetobacter pasteurianus as the prevailing species. Also, the presence of occasional members of the cocoa bean fermentation process was revealed (such as Erwinia tasmaniensis, Lactobacillus brevis, Lactobacillus casei, Lactobacillus rhamnosus, Lactococcus lactis, Leuconostoc mesenteroides, and Oenococcus oeni. Furthermore, the sequence reads associated with viral communities were of a restricted diversity, dominated by Myoviridae and Siphoviridae, and reflecting Lactobacillus as the dominant host. To conclude, an accurate overview of all members of a cocoa bean fermentation process sample was revealed, indicating the superiority of metagenomic sequencing over previously used techniques.

  16. Phylogenetic analysis of a spontaneous cocoa bean fermentation metagenome reveals new insights into its bacterial and fungal community diversity.

    Science.gov (United States)

    Illeghems, Koen; De Vuyst, Luc; Papalexandratou, Zoi; Weckx, Stefan

    2012-01-01

    This is the first report on the phylogenetic analysis of the community diversity of a single spontaneous cocoa bean box fermentation sample through a metagenomic approach involving 454 pyrosequencing. Several sequence-based and composition-based taxonomic profiling tools were used and evaluated to avoid software-dependent results and their outcome was validated by comparison with previously obtained culture-dependent and culture-independent data. Overall, this approach revealed a wider bacterial (mainly γ-Proteobacteria) and fungal diversity than previously found. Further, the use of a combination of different classification methods, in a software-independent way, helped to understand the actual composition of the microbial ecosystem under study. In addition, bacteriophage-related sequences were found. The bacterial diversity depended partially on the methods used, as composition-based methods predicted a wider diversity than sequence-based methods, and as classification methods based solely on phylogenetic marker genes predicted a more restricted diversity compared with methods that took all reads into account. The metagenomic sequencing analysis identified Hanseniaspora uvarum, Hanseniaspora opuntiae, Saccharomyces cerevisiae, Lactobacillus fermentum, and Acetobacter pasteurianus as the prevailing species. Also, the presence of occasional members of the cocoa bean fermentation process was revealed (such as Erwinia tasmaniensis, Lactobacillus brevis, Lactobacillus casei, Lactobacillus rhamnosus, Lactococcus lactis, Leuconostoc mesenteroides, and Oenococcus oeni). Furthermore, the sequence reads associated with viral communities were of a restricted diversity, dominated by Myoviridae and Siphoviridae, and reflecting Lactobacillus as the dominant host. To conclude, an accurate overview of all members of a cocoa bean fermentation process sample was revealed, indicating the superiority of metagenomic sequencing over previously used techniques.

  17. Functioned silver nanoparticle loaded activated carbon for the recovery of bioactive molecule from bacterial fermenter for its bactericidal activity

    Science.gov (United States)

    Arivizhivendhan, Villalan; Mahesh, Mannacharaju; Boopathy, Ramasamy; Karthikeyan, Sekar; Mary, Rathanasamy Regina; Sekaran, Ganesan

    2018-01-01

    A novel continuous production and extraction of bacterial bioactive prodigiosin (PG) from fermented using silver nanoparticle impregnated functioned activated carbon composite is proposed for cost-effective and ecofriendly microbial technique. Hence, in this investigation silver nanoparticle was impregnated onto functioned activated carbon ([AC]F) as a support matrix and to enable the separation of PG conjugated silver nanoparticle from the fermented medium. A laboratory scale experiment was carried out to evaluate the continuous production and recovery of PG using [AC@Ag]F. Ag nanoparticle impregnated [AC]F ([AC@Ag]F) characterized by FT-IR, XRD, TGA, DSC and SEM. Instrumental analyses confirmed that Ag nanoparticles significantly impregnated on AC through the functionalization of AC with diethanolamine and it enhances the binding capacity between AC and Ag. The various process parameters, such as contact time, pH, and mass of [AC@Ag]F, were statistically optimized for the recovery of PG using Response Surface Methodology (RSM). The maximum extraction of PG in [AC@Ag]F was found to be 16.2 ± 0.2 mg g-1, its twofold higher than [AC]F. Further, PG conjugated [AC@Ag]F and ([AC@Ag]F-PG) were checked for the growth inhibition of gram negative and gram positive bacteria without formation of biofilm upto 96 h. Hence, the developed matrix could be eco-friendly, viable and lower energy consumption step for separation of the bacterial bioactive PG from fermented broth. In additionally, [AC@Ag]F-PG was used as an antifouling matrix without formation of biofilm.

  18. Complete genome sequence of Pseudomonas rhizosphaerae IH5T (=DSM 16299T), a phosphate-solubilizing rhizobacterium for bacterial biofertilizer.

    Science.gov (United States)

    Kwak, Yunyoung; Jung, Byung Kwon; Shin, Jae-Ho

    2015-01-10

    Pseudomonas rhizosphaerae IH5(T) (=DSM 16299(T)), isolated from the rhizospheric soil of grass growing in Spain, has been reported as a novel species of the genus Pseudomonas harboring insoluble phosphorus solubilizing activity. To understanding the multifunctional biofertilizer better, we report the complete genome sequence of P. rhizosphaerae IH5(T). Copyright © 2014 Elsevier B.V. All rights reserved.

  19. A novel signal transduction pathway that modulates rhl quorum sensing and bacterial virulence in Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Qiao Cao

    2014-08-01

    Full Text Available The rhl quorum-sensing (QS system plays critical roles in the pathogenesis of P. aeruginosa. However, the regulatory effects that occur directly upstream of the rhl QS system are poorly understood. Here, we show that deletion of gene encoding for the two-component sensor BfmS leads to the activation of its cognate response regulator BfmR, which in turn directly binds to the promoter and decreases the expression of the rhlR gene that encodes the QS regulator RhlR, causing the inhibition of the rhl QS system. In the absence of bfmS, the Acka-Pta pathway can modulate the regulatory activity of BfmR. In addition, BfmS tunes the expression of 202 genes that comprise 3.6% of the P. aeruginosa genome. We further demonstrate that deletion of bfmS causes substantially reduced virulence in lettuce leaf, reduced cytotoxicity, enhanced invasion, and reduced bacterial survival during acute mouse lung infection. Intriguingly, specific missense mutations, which occur naturally in the bfmS gene in P. aeruginosa cystic fibrosis (CF isolates such as DK2 strains and RP73 strain, can produce BfmS variants (BfmSL181P, BfmSL181P/E376Q, and BfmSR393H that no longer repress, but instead activate BfmR. As a result, BfmS variants, but not the wild-type BfmS, inhibit the rhl QS system. This study thus uncovers a previously unexplored signal transduction pathway, BfmS/BfmR/RhlR, for the regulation of rhl QS in P. aeruginosa. We propose that BfmRS TCS may have an important role in the regulation and evolution of P. aeruginosa virulence during chronic infection in CF lungs.

  20. Resistant and susceptible responses in alfalfa (Medicago sativa) to bacterial stem blight caused by Pseudomonas syringae pv. syringae.

    Science.gov (United States)

    Nemchinov, Lev G; Shao, Jonathan; Lee, Maya N; Postnikova, Olga A; Samac, Deborah A

    2017-01-01

    Bacterial stem blight caused by Pseudomonas syringae pv. syringae is a common disease of alfalfa (Medicago sativa L). Little is known about host-pathogen interactions and host defense mechanisms. Here, individual resistant and susceptible plants were selected from cultivars Maverick and ZG9830 and used for transcript profiling at 24 and 72 hours after inoculation (hai) with the isolate PssALF3. Bioinformatic analysis revealed a number of differentially expressed genes (DEGs) in resistant and susceptible genotypes. Although resistant plants from each cultivar produced a hypersensitive response, transcriptome analyses indicated that they respond differently at the molecular level. The number of DEGs was higher in resistant plants of ZG9830 at 24 hai than in Maverick, suggesting that ZG9830 plants had a more rapid effector triggered immune response. Unique up-regulated genes in resistant ZG9830 plants included genes encoding putative nematode resistance HSPRO2-like proteins, orthologs for the rice Xa21 and soybean Rpg1-b resistance genes, and TIR-containing R genes lacking both NBS and LRR domains. The suite of R genes up-regulated in resistant Maverick plants had an over-representation of R genes in the CC-NBS-LRR family including two genes for atypical CCR domains and a putative ortholog of the Arabidopsis RPM1 gene. Resistance in both cultivars appears to be mediated primarily by WRKY family transcription factors and expression of genes involved in protein phosphorylation, regulation of transcription, defense response including synthesis of isoflavonoids, and oxidation-reduction processes. These results will further the identification of mechanisms involved in resistance to facilitate selection of parent populations and development of commercial varieties.

  1. Resistant and susceptible responses in alfalfa (Medicago sativa to bacterial stem blight caused by Pseudomonas syringae pv. syringae.

    Directory of Open Access Journals (Sweden)

    Lev G Nemchinov

    Full Text Available Bacterial stem blight caused by Pseudomonas syringae pv. syringae is a common disease of alfalfa (Medicago sativa L. Little is known about host-pathogen interactions and host defense mechanisms. Here, individual resistant and susceptible plants were selected from cultivars Maverick and ZG9830 and used for transcript profiling at 24 and 72 hours after inoculation (hai with the isolate PssALF3. Bioinformatic analysis revealed a number of differentially expressed genes (DEGs in resistant and susceptible genotypes. Although resistant plants from each cultivar produced a hypersensitive response, transcriptome analyses indicated that they respond differently at the molecular level. The number of DEGs was higher in resistant plants of ZG9830 at 24 hai than in Maverick, suggesting that ZG9830 plants had a more rapid effector triggered immune response. Unique up-regulated genes in resistant ZG9830 plants included genes encoding putative nematode resistance HSPRO2-like proteins, orthologs for the rice Xa21 and soybean Rpg1-b resistance genes, and TIR-containing R genes lacking both NBS and LRR domains. The suite of R genes up-regulated in resistant Maverick plants had an over-representation of R genes in the CC-NBS-LRR family including two genes for atypical CCR domains and a putative ortholog of the Arabidopsis RPM1 gene. Resistance in both cultivars appears to be mediated primarily by WRKY family transcription factors and expression of genes involved in protein phosphorylation, regulation of transcription, defense response including synthesis of isoflavonoids, and oxidation-reduction processes. These results will further the identification of mechanisms involved in resistance to facilitate selection of parent populations and development of commercial varieties.

  2. An epoxide hydrolase secreted by Pseudomonas aeruginosa decreases mucociliary transport and hinders bacterial clearance from the lung.

    Science.gov (United States)

    Hvorecny, Kelli L; Dolben, Emily; Moreau-Marquis, Sophie; Hampton, Thomas H; Shabaneh, Tamer B; Flitter, Becca A; Bahl, Christopher D; Bomberger, Jennifer M; Levy, Bruce D; Stanton, Bruce A; Hogan, Deborah A; Madden, Dean R

    2018-01-01

    The opportunistic pathogen Pseudomonas aeruginosa colonizes the lungs of susceptible individuals by deploying virulence factors targeting host defenses. The secreted factor Cif (cystic fibrosis transmembrane conductance regulator inhibitory factor) dysregulates the endocytic recycling of CFTR and thus reduces CFTR abundance in host epithelial membranes. We have postulated that the decrease in ion secretion mediated by Cif would slow mucociliary transport and decrease bacterial clearance from the lungs. To test this hypothesis, we explored the effects of Cif in cultured epithelia and in the lungs of mice. We developed a strategy to interpret the "hurricane-like" motions observed in reconstituted cultures and identified a Cif-mediated decrease in the velocity of mucus transport in vitro. Presence of Cif also increased the number of bacteria recovered at two time points in an acute mouse model of pneumonia caused by P. aeruginosa. Furthermore, recent work has demonstrated an inverse correlation between the airway concentrations of Cif and 15-epi-lipoxin A4, a proresolving lipid mediator important in host defense and the resolution of pathogen-initiated inflammation. Here, we observe elevated levels of 15-epi-lipoxin A4 in the lungs of mice infected with a strain of P. aeruginosa that expresses only an inactive form of cif compared with those mice infected with wild-type P. aeruginosa. Together these data support the inclusion of Cif on the list of virulence factors that assist P. aeruginosa in colonizing and damaging the airways of compromised patients. Furthermore, this study establishes techniques that enable our groups to explore the underlying mechanisms of Cif effects during respiratory infection.

  3. Host genetic background influences the response to the opportunistic Pseudomonas aeruginosa infection altering cell-mediated immunity and bacterial replication.

    Directory of Open Access Journals (Sweden)

    Maura De Simone

    Full Text Available Pseudomonas aeruginosa is a common cause of healthcare-associated infections including pneumonia, bloodstream, urinary tract, and surgical site infections. The clinical outcome of P. aeruginosa infections may be extremely variable among individuals at risk and patients affected by cystic fibrosis. However, risk factors for P. aeruginosa infection remain largely unknown. To identify and track the host factors influencing P. aeruginosa lung infections, inbred immunocompetent mouse strains were screened in a pneumonia model system. A/J, BALB/cJ, BALB/cAnNCrl, BALB/cByJ, C3H/HeOuJ, C57BL/6J, C57BL/6NCrl, DBA/2J, and 129S2/SvPasCRL mice were infected with P. aeruginosa clinical strain and monitored for body weight and mortality up to seven days. The most deviant survival phenotypes were observed for A/J, 129S2/SvPasCRL and DBA/2J showing high susceptibility while BALB/cAnNCrl and C3H/HeOuJ showing more resistance to P. aeruginosa infection. Next, one of the most susceptible and resistant mouse strains were characterized for their deviant clinical and immunological phenotype by scoring bacterial count, cell-mediated immunity, cytokines and chemokines profile and lung pathology in an early time course. Susceptible A/J mice showed significantly higher bacterial burden, higher cytokines and chemokines levels but lower leukocyte recruitment, particularly neutrophils, when compared to C3H/HeOuJ resistant mice. Pathologic scores showed lower inflammatory severity, reduced intraluminal and interstitial inflammation extent, bronchial and parenchymal involvement and diminished alveolar damage in the lungs of A/J when compared to C3H/HeOuJ. Our findings indicate that during an early phase of infection a prompt inflammatory response in the airways set the conditions for a non-permissive environment to P. aeruginosa replication and lock the spread to other organs. Host gene(s may have a role in the reduction of cell-mediated immunity playing a critical role in

  4. Antibacterial Activity of Cinnamaldehyde and Estragole Extracted from Plant Essential Oils against Pseudomonas syringae pv. actinidiae Causing Bacterial Canker Disease in Kiwifruit

    Science.gov (United States)

    Song, Yu-Rim; Choi, Min-Seon; Choi, Geun-Won; Park, Il-Kwon; Oh, Chang-Sik

    2016-01-01

    Pseudomonas syringae pv. actinidiae (Psa) causes bacterial canker disease in kiwifruit. Antibacterial activity of plant essential oils (PEOs) originating from 49 plant species were tested against Psa by a vapor diffusion and a liquid culture assays. The five PEOs from Pimenta racemosa, P. dioica, Melaleuca linariifolia, M. cajuputii, and Cinnamomum cassia efficiently inhibited Psa growth by either assays. Among their major components, estragole, eugenol, and methyl eugenol showed significant antibacterial activity by only the liquid culture assay, while cinnamaldehyde exhibited antibacterial activity by both assays. The minimum inhibitory concentrations (MICs) of estragole and cinnamaldehyde by the liquid culture assay were 1,250 and 2,500 ppm, respectively. The MIC of cinnamaldehyde by the vapor diffusion assay was 5,000 ppm. Based on the formation of clear zones or the decrease of optical density caused by these compounds, they might kill the bacterial cells and this feature might be useful for managing the bacterial canker disease in kiwifruit. PMID:27493612

  5. Antibacterial Activity of Cinnamaldehyde and Estragole Extracted from Plant Essential Oils against Pseudomonas syringae pv. actinidiae Causing Bacterial Canker Disease in Kiwifruit

    Directory of Open Access Journals (Sweden)

    Yu-Rim Song

    2016-08-01

    Full Text Available Pseudomonas syringae pv. actinidiae (Psa causes bacterial canker disease in kiwifruit. Antibacterial activity of plant essential oils (PEOs originating from 49 plant species were tested against Psa by a vapor diffusion and a liquid culture assays. The five PEOs from Pimenta racemosa, P. dioica, Melaleuca linariifolia, M. cajuputii, and Cinnamomum cassia efficiently inhibited Psa growth by either assays. Among their major components, estragole, eugenol, and methyl eugenol showed significant antibacterial activity by only the liquid culture assay, while cinnamaldehyde exhibited antibacterial activity by both assays. The minimum inhibitory concentrations (MICs of estragole and cinnamaldehyde by the liquid culture assay were 1,250 and 2,500 ppm, respectively. The MIC of cinnamaldehyde by the vapor diffusion assay was 5,000 ppm. Based on the formation of clear zones or the decrease of optical density caused by these compounds, they might kill the bacterial cells and this feature might be useful for managing the bacterial canker disease in kiwifruit.

  6. Single-cell level based approach to investigate bacterial metabolism during batch industrial fermentation

    DEFF Research Database (Denmark)

    Nierychlo, Marta; Larsen, Poul; Eriksen, Niels T.

    culture of Escherichia coli MG1655 was used to investigate glucose and acetate metabolism at single-cell level during different stages of glucose batch fermentation process. Uptake of the substrates was observed and measured in situ by quantitative microautoradiography. Sub-populations of Escherichia coli...

  7. Effects of a dual-purpose bacterial inoculant on the fermentation ...

    African Journals Online (AJOL)

    The objective of this study was to investigate the effects of inoculating Lactisil Maize, a dual-purpose inoculant, on the fermentation characteristics and nutritive value of high-moisture maize silage and the performance of lactating cows receiving the silage in their diets. Whole-crop maize was harvested at 253 g dry matter ...

  8. Screening and characterization of lactic acid bacterial strains that produce fermented milk and reduce cholesterol levels

    Directory of Open Access Journals (Sweden)

    Xuefang Guan

    Full Text Available ABSTRACT Objective To screen for and characterize lactic acid bacteria strains with the ability to produce fermented milk and reduce cholesterol levels. Methods The strains were isolated from traditional fermented milk in China. In vitro and in vivo evaluation of cholesterol-reduction were used to identify and verify strains of interest. Characteristics were analyzed using spectrophotometry and plate counting assays. Results The isolate HLX37 consistently produced fermented milk with strong cholesterol-reducing properties was identified as Lactobacillus plantarum (accession number: KR105940 and was thus selected for further study. The cholesterol reduction by strain HLX37 was 45.84%. The isolates were acid-tolerant at pH 2.5 and bile-tolerant at 0.5% (w/v in simulated gastric juice (pH 2.5 for 2 h and in simulated intestinal fluid (pH 8.0 for 3 h. The auto-aggregation rate increased to 87.74% after 24 h, while the co-aggregation with Escherichia coli DH5 was 27.76%. Strain HLX37 was intrinsically resistant to antibiotics such as penicillin, tobramycin, kanamycin, streptomycin, vancomycin and amikacin. Compared with rats in the model hyperlipidemia group, the total cholesterol content in the serum and the liver as well as the atherogenic index of rats in the viable fermented milk group significantly decreased by 23.33%, 32.37% and 40.23%, respectively. Fewer fat vacuoles and other lesions in liver tissue were present in both the inactivated and viable fermented milk groups compared to the model group. Conclusion These studies indicate that strain HLX37 of L. plantarum demonstrates probiotic potential, potential for use as a candidate for commercial use for promoting health.

  9. Correlation of Particular Bacterial PCR-Denaturing Gradient Gel Electrophoresis Patterns with Bovine Ruminal Fermentation Parameters and Feed Efficiency Traits ▿ †

    OpenAIRE

    Hernandez-Sanabria, Emma; Guan, Le Luo; Goonewardene, Laksiri A.; Li, Meiju; Mujibi, Denis F.; Stothard, Paul; Moore, Stephen S; Leon-Quintero, Monica C.

    2010-01-01

    The influence of rumen microbial structure and functions on host physiology remains poorly understood. This study aimed to investigate the interaction between the ruminal microflora and the host by correlating bacterial diversity with fermentation measurements and feed efficiency traits, including dry matter intake, feed conversion ratio, average daily gain, and residual feed intake, using culture-independent methods. Universal bacterial partial 16S rRNA gene products were amplified from rumi...

  10. Exploring the Bacterial Microbiota of Colombian Fermented Maize Dough “Masa Agria” (Maiz Añejo)

    Science.gov (United States)

    Chaves-Lopez, Clemencia; Serio, Annalisa; Delgado-Ospina, Johannes; Rossi, Chiara; Grande-Tovar, Carlos D.; Paparella, Antonello

    2016-01-01

    Masa Agria is a naturally fermented maize dough produced in Colombia, very common in the traditional gastronomy. In this study we used culture-dependent and RNA-based pyrosequencing to investigate the bacterial community structure of Masa Agria samples produced in the south west of Colombia. The mean value of cell density was 7.6 log CFU/g of presumptive lactic acid bacteria, 5.4 log cfu/g for presumptive acetic bacteria and 5.6 og CFU/g for yeasts. The abundance of these microorganisms is also responsible for the low pH (3.1–3.7) registered. Although the 16S rRNA pyrosequencing revealed that the analyzed samples were different in bacteria richness and diversity, the genera Lactobacillus, Weissella, and Acetobacter were predominant. In particular, the most common species were Lactobacillus plantarum and Acetobacter fabarum, followed by L. fermentum, L. vaccinostercus, and Pediococcus argentinicus. Several microorganisms of environmental origin, such as Dechloromonas and most of all Sphingobium spp., revealed in each sample, were detected, and also bacteria related to maize, such as Phytoplasma. In conclusion, our results elucidated for the first time the structures of the bacterial communities of Masa Agria samples obtained from different producers, identifying the specific dominant species and revealing a complete picture of the bacterial consortium in this specific niche. The selective pressure of tropical environments may favor microbial biodiversity characterized by a useful technological potential. PMID:27524979

  11. Exploring the bacterial microbiota of Colombian fermented maize dough “Masa Agria” (Maiz Añejo

    Directory of Open Access Journals (Sweden)

    Clemencia Chaves

    2016-07-01

    Full Text Available Masa Agria is a naturally fermented maize dough produced in Colombia, very common in the traditional gastronomy. In this study we used culture-dependent and RNA-based pyrosequencing to investigate the bacterial community structure of Masa Agria samples produced in the south west of Colombia. The mean value of cell density was 7.6 Log CFU/g of presumptive lactic acid bacteria (LAB, 5.4 Log cfu/g for presumptive acetic bacteria and 5.6 Log CFU/g for yeasts. The abundance of these microorganisms is also responsible for the low pH (3.1-3.7 registered. Although the 16S rRNA pyrosequencing revealed that the analyzed samples were different in bacteria richness and diversity, the genera Lactobacillus, Weissella and Acetobacter were predominant. In particular, the most common species were Lactobacillus plantarum and Acetobacter fabarum, followed by Lb. fermentum, Lb. vaccinostercus and Pediococcus argentinicus. Several microorganisms of environmental origin, such as Dechloromonas and most of all Sphingobium spp., revealed in each sample, were detected, and also bacteria related to maize, such as Phytoplasma. In conclusion, our results elucidated for the first time the structures of the bacterial communities of Masa Agria samples obtained from different producers, identifying the specific dominant species and revealing a complete picture of the bacterial consortium in this specific niche. The selective pressure of tropical environments may favour microbial biodiversity characterized by a useful technological potential.

  12. Absence of phosphatidylcholine in bacterial membranes facilitates translocation of Sec-dependent β-lactamase AmpC from cytoplasm to periplasm in two Pseudomonas strains.

    Science.gov (United States)

    Liu, Xin; Sun, Yufang; Cao, Fang; Xiong, Min; Yang, Sheng; Li, Yang; Yu, Xuejing; Li, Yadong; Wang, Xingguo

    2017-05-01

    Phosphatidylcholine (PC) is a rare membrane lipid in bacteria but crucial for virulence of various plant and animal pathogens. The pcs- mutant lacking PC in bacterial membranes of Pseudomonas syringae pv. syringae van Hall 1336 displayed more ampicillin resistance. Ampicillin susceptibility tests gave an IC50 (half maximal inhibitory concentration) of 52 mg/ml for Pseudomonas syringae pv. syringae van Hall 1336, 53 mg/ml for the complemented strain 1336 RM (pcs-/+) and 90 mg/ml for the 1336 pcs- mutant. Activity assay of β-lactamase in periplasmic extracts gave 0.050 U/mg for the 1336 wild type, 0.052 U/mg for the 1336RM (pcs-/+), 0.086 U/mg for the 1336 pcs- mutant. Analysis by western blotting showed that the content of AmpC enzyme was markedly different in periplasmic extracts between the wild-type and pcs- mutant strains. Reverse transcriptase PCR also showed that the presence or absence of PC in bacterial membranes did not affect the transcription of ampC gene. The phenotype of the pcs- mutant was able to be recovered to the wild type by introducing a wild-type pcs gene into the pcs- mutant. Similar results were also obtained from the soil-dwelling bacterium Pseudomonas sp. 593. Our results demonstrate that the absence of PC in bacterial membranes facilitates the translocation of Sec-dependent β-lactamase AmpC from cytoplasm to periplasm, and the enhanced ampicillin-resistance in the pcs- strains mainly comes from effective translocation of AmpC via Sec-pathway. Copyright © 2016. Published by Elsevier Ltd.

  13. The efficacy of immediate versus delayed antibiotic administration on bacterial growth and biofilm production of selected strains of uropathogenic Escherichia coli and Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Leah Gandee

    2015-02-01

    Full Text Available Purpose The treatment of urinary tract infections (UTI with antibiotics is commonly used, but recurrence and antibiotic resistance have been growing and concerning clinicians. We studied whether the rapid onset of a protective biofilm may be responsible for the lack of effectiveness of antibiotics against selected bacteria. Materials and Methods Two established uropathogenic Escherichia coli strains, UTI89 and CFT073, and two Pseudomonas aeruginosa strains, PA01 and Boston-41501, were studied to establish a reliable biofilm formation process. Bacterial growth (BG was determined by optical density at 600 nm (OD 600 using a spectrophotometer, while biofilm formation (BF using crystal violet staining was measured at OD 550. Next, these bacterial strains were treated with clinically relevant antibiotics, ciprofloxacin HCl (200 ng/mL and 2 μg/mL, nitrofurantoin (20 μg/mL and 40 μg/mL and ampicillin (50 μg/mL at time points of 0 (T0 or after 6 hours of culture (T6. All measurements, including controls (bacteria -1% DMSO, were done in triplicates and repeated three times for consistency. Results The tested antibiotics effectively inhibited both BG and BF when administered at T0 for UPEC strains, but not when the antibiotic administration started 6 hours later. For Pseudomonas strains, only Ciprofloxacin was able to significantly inhibit bacterial growth at T0 but only at the higher concentration of 2 μg/mL for T6. Conclusion When established UPEC and Pseudomonas bacteria were allowed to culture for 6 hours before initialization of treatment, the therapeutic effect of selected antibiotics was greatly suppressed when compared to immediate treatment, probably as a result of the protective nature of the biofilm.

  14. Analysis of fermentation processes using flow microfluorometry: Single-parameter observations of batch bacterial growth.

    Science.gov (United States)

    Fazel-Madjlessi, Jila; Bailey, J E

    2002-09-05

    The laser flow microfluorometer (FMF) can determine the amounts of certain components in single cells at sample rates of several thousand cells per second. This technique has been employed to characterize Bacillus subtilis populations in batch fermentations with different inocula. Protein and nucleic acid distributions obtained by FMF analyses at different times during the batch have been decomposed using an optimized fit of summed subpopulation distributions. The results of these decomposition calculations, some of which have been approximately confirmed by independent microscopic observations, indicate that the relative numbers of single rods, cell chains, spores, and swollen rounded cells change dramatically during the entire fermentation including the stationary phase. The dynamics of these subpopulations may be related to secondary metabolite production. Copyright 2002 Wiley Periodicals, Inc.

  15. Comparison of bacterial community changes in fermenting kimchi at two different temperatures using a denaturing gradient gel electrophoresis analysis.

    Science.gov (United States)

    Hong, Yeun; Yang, Hee-Seok; Chang, Hae-Choon; Kim, Hae-Yeong

    2013-01-01

    A polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technique followed by sequencing of the 16S rDNA fragments eluted from the bands of interest on denaturing gradient gels was used to monitor changes in the bacterial microflora of two commercial kimchi, salted cabbage, and ingredient mix samples during 30 days of fermentation at 4°C and 10°C. Leuconostoc (Lc.) was the dominant lactic acid bacteria (LAB) over Lactobacillus (Lb.) species at 4°C. Weissella confusa was detected in the ingredient mix and also in kimchi samples throughout fermentation in both samples at 4°C and 10°C. Lc. gelidum was detected as the dominant LAB at 4°C in both samples. The temperature affected the LAB profile of kimchi by varing the pH, which was primarily caused by the temperature-dependent competition among different LAB species in kimchi. At 4°C, the sample variations in pH and titratable acidity were more conspicuous owing to the delayed growth of LAB. Temperature affected only initial decreases in pH and initial increases in viable cell counts, but affected both the initial increases and final values of titratable acidity. The initial microflora in the kimchi sample was probably determined by the microflora of the ingredient mix, not by that of the salted cabbage. The microbial distributions in the samples used in this study resembled across the different kimchi samples and the different fermentation temperatures as the numbers of LAB increased and titratable acidity decreased.

  16. Culture-independent bacterial community analysis of the salty-fermented fish paste products of Thailand and Laos.

    Science.gov (United States)

    Marui, Junichiro; Boulom, Sayvisene; Panthavee, Wanchai; Momma, Mari; Kusumoto, Ken-Ichi; Nakahara, Kazuhiko; Saito, Masayoshi

    2015-01-01

    A bacterial community analysis, using a culture-independent method (polymerase chain reaction-denaturing gradient gel electrophoresis), detected 17 species of bacteria including species of the genera Tetragenococcus, Lactobacillus, Pediococcus, Weissella Halanaerobium, Clostridium, and Sphingomonas in a traditional salty-fermented fish paste known as pla-ra or pa-daek in Thailand and Laos, which is used as a storage-stable multi-purpose seasoning. The representative genus of lactic acid bacteria seemed to vary in the 10 products collected from Thailand and Laos. Tetragenococci were common in products from central Thailand and Vientiane in Laos which had salinities of not less than 11% and pH values ranging from 5.6 to 6.1. However, lactobacilli were common in products from northern Thailand which had the lowest salinities (8.3-8.6%) and pH values (4.5-4.8) of all the samples examined. Two Lactobacillus and one Tetragenococcus species were detected in one product from northeastern Thailand containing 10% salt. These results suggest that salinity in pla-ra/pa-daek is an important determinant of the representative genus of lactic acid bacteria such as, Tetragenococcus or Lactobacillus. Additionally, differences in the acidity between these two groups seemed to be related to the production of d-/l-lactic acid in the lactic acid bacteria in each product. This is the first study to report a correlation between bacterial community structure and taste components in pla-ra/pa-daek products from various regions. This scientific work on a traditional fermented food will be useful in helping local producers meet differing consumer preferences in various regions.

  17. Mucin secretion in germfree rats fed fiber-free and psyllium diets and bacterial mass and carbohydrate fermentation after colonization.

    Science.gov (United States)

    Cabotaje, L M; Shinnick, F L; Lopéz-Guisa, J M; Marlett, J A

    1994-01-01

    The effect of psyllium on mucin secretion was determined by comparing water-soluble and -insoluble fractions of excreta from germfree rats fed a fiber-free (FF) diet or a diet containing psyllium seed husk (PS). Excreta from the same rats after colonization with a rat mixed cecal culture were separated into water-soluble, plant, and bacterial fractions to compare the remaining carbohydrate and the mass of bacteria. The sugar composition and water solubility of carbohydrate in excreta from germfree rats fed FF diets indicated that a primary fermentable substrate was mucin. PS increased fecal excretion of mucin-derived sugars almost threefold in germfree rats. Fecal carbohydrate was reduced from 619 to 237 mumol/g of dry feces and mostly in the bacterial fraction when rats fed an FF diet were colonized. The total sugar content and the amount of muramic acid, but not bacterial counts and mass, indicated that PS increased fecal bacteria. Fractionation of excreta from PS-fed rats was complicated by a gel which, based on sugar composition, was PS. Sugar composition of the water-soluble fraction from excreta from PS-fed rats suggested that it contained some bacterial component, possibly exopolysaccharides and some of the PS, but not mucin. PS digestibility ranged from 60 to 80%, depending on what fecal fraction was used for output. Because of the presence of PS-derived sugars in the gel and soluble fraction, it was not possible to determine which, if any, of the PS digestibilities was correct. PMID:8017918

  18. Biocontrol of Bacterial Leaf Blight of Rice and Profiling of Secondary Metabolites Produced by Rhizospheric Pseudomonas aeruginosa BRp3

    Science.gov (United States)

    Yasmin, Sumera; Hafeez, Fauzia Y.; Mirza, Muhammad S.; Rasul, Maria; Arshad, Hafiz M. I.; Zubair, Muhammad; Iqbal, Mazhar

    2017-01-01

    Xanthomonas oryzae pv. oryzae (Xoo) is widely prevalent and causes Bacterial Leaf Blight (BLB) in Basmati rice grown in different areas of Pakistan. There is a need to use environmentally safe approaches to overcome the loss of grain yield in rice due to this disease. The present study aimed to develop inocula, based on native antagonistic bacteria for biocontrol of BLB and to increase the yield of Super Basmati rice variety. Out of 512 bacteria isolated from the rice rhizosphere and screened for plant growth promoting determinants, the isolate BRp3 was found to be the best as it solubilized 97 μg/ mL phosphorus, produced 30 μg/mL phytohormone indole acetic acid and 15 mg/ L siderophores in vitro. The isolate BRp3 was found to be a Pseudomonas aeruginosa based on 16S rRNA gene sequencing (accession no. HQ840693). This bacterium showed antagonism in vitro against different phytopathogens including Xoo and Fusarium spp. Strain BRp3 showed consistent pathogen suppression of different strains of BLB pathogen in rice. Mass spectrometric analysis detected the production of siderophores (1-hydroxy-phenazine, pyocyanin, and pyochellin), rhamnolipids and a series of already characterized 4-hydroxy-2-alkylquinolines (HAQs) as well as novel 2,3,4-trihydroxy-2-alkylquinolines and 1,2,3,4-tetrahydroxy-2-alkylquinolines in crude extract of BRp3. These secondary metabolites might be responsible for the profound antibacterial activity of BRp3 against Xoo pathogen. Another contributing factor toward the suppression of the pathogen was the induction of defense related enzymes in the rice plant by the inoculated strain BRp3. When used as an inoculant in a field trial, this strain enhanced the grain and straw yields by 51 and 55%, respectively, over non-inoculated control. Confocal Laser Scanning Microscopy (CLSM) used in combination with immunofluorescence marker confirmed P. aeruginosa BRp3 in the rice rhizosphere under sterilized as well as field conditions. The results provide

  19. Biocontrol of Bacterial Leaf Blight of Rice and Profiling of Secondary Metabolites Produced by Rhizospheric Pseudomonas aeruginosa BRp3

    Directory of Open Access Journals (Sweden)

    Sumera Yasmin

    2017-09-01

    Full Text Available Xanthomonas oryzae pv. oryzae (Xoo is widely prevalent and causes Bacterial Leaf Blight (BLB in Basmati rice grown in different areas of Pakistan. There is a need to use environmentally safe approaches to overcome the loss of grain yield in rice due to this disease. The present study aimed to develop inocula, based on native antagonistic bacteria for biocontrol of BLB and to increase the yield of Super Basmati rice variety. Out of 512 bacteria isolated from the rice rhizosphere and screened for plant growth promoting determinants, the isolate BRp3 was found to be the best as it solubilized 97 μg/ mL phosphorus, produced 30 μg/mL phytohormone indole acetic acid and 15 mg/ L siderophores in vitro. The isolate BRp3 was found to be a Pseudomonas aeruginosa based on 16S rRNA gene sequencing (accession no. HQ840693. This bacterium showed antagonism in vitro against different phytopathogens including Xoo and Fusarium spp. Strain BRp3 showed consistent pathogen suppression of different strains of BLB pathogen in rice. Mass spectrometric analysis detected the production of siderophores (1-hydroxy-phenazine, pyocyanin, and pyochellin, rhamnolipids and a series of already characterized 4-hydroxy-2-alkylquinolines (HAQs as well as novel 2,3,4-trihydroxy-2-alkylquinolines and 1,2,3,4-tetrahydroxy-2-alkylquinolines in crude extract of BRp3. These secondary metabolites might be responsible for the profound antibacterial activity of BRp3 against Xoo pathogen. Another contributing factor toward the suppression of the pathogen was the induction of defense related enzymes in the rice plant by the inoculated strain BRp3. When used as an inoculant in a field trial, this strain enhanced the grain and straw yields by 51 and 55%, respectively, over non-inoculated control. Confocal Laser Scanning Microscopy (CLSM used in combination with immunofluorescence marker confirmed P. aeruginosa BRp3 in the rice rhizosphere under sterilized as well as field conditions. The

  20. Comparison of Bacterial Cellulose Production among Different Strains and Fermented Media

    Directory of Open Access Journals (Sweden)

    Maryam Jalili Tabaii

    2015-12-01

    Full Text Available The effect of different carbon sources on bacterial cellulose production by Gluconacetobacter xylinus (PTCC 1734 and two newly isolated strains (from vinegar under static culture conditions was studied. The production of bacterial cellulose was examined in modified Hestrin-Shramm medium by replacing D-glucose with other carbon sources. The results showed that the yield and characteristics of bacterial cellulose were influenced by the type of carbon source. Glycerol gave the highest yield in all of the studied strains (6%, 9.7% and 3.8% for S, A2 strain and Gluconacetobacter xylinus (PTCC 1734, respectively. The maximum dry bacterial cellulose weight in the glycerol containing medium is due to A2 strain (1.9 g l-1 in comparison to Gluconacetobacter xylinus as reference strain (0.76 g l-1. Although all of the studied strains were in Gluconacetobacter family, each used different sugars for maximum production after glycerol (mannitol and fructose for two newly isolated strains and glucose for Gluconacetobacter xylinus. The maximum moisture content was observed when sucrose and food-grade sucrose were used as carbon source. Contrary to expectations, while the maximum thickness of bacterial cellulose membrane was attained when glycerol was used, bacterial cellulose from glycerol had less moisture content than the others. The oxidized cellulose showed antibacterial activities, which makes it as a good candidate for food-preservatives.

  1. Screening of bacterial direct-fed microbials for their antimethanogenic potential in vitro and assessment of their effect on ruminal fermentation and microbial profiles in sheep.

    Science.gov (United States)

    Jeyanathan, J; Martin, C; Morgavi, D P

    2016-02-01

    Direct-fed microbials (DFM) are used to modulate ruminal function and induce beneficial effects on ruminants. The objectives of this work were to 1) screen bacterial strains for their antimethanogenic potential in vitro and 2) assess the effect of 3 selected DFM on ruminal methane (CH) emissions, fermentation parameters, and microbial profiles in sheep. Forty-five bacterial strains were preselected based on their metabolism and fermentation characteristics. These bacteria were screened for their ability to reduce ruminal methanogenesis using 24-h batch incubations and an inoculum of 10 cfu/mL of medium. The addition of bacterial strains stimulated ruminal fermentation with increases in total gas production for 41 strains ( Methane production was reduced by 13% ( < 0.05) with after 2 wk of DFM administration, and this effect was maintained throughout the treatment and posttreatment periods. In contrast, had no effect on CH production, and increased it by 16% ( < 0.05) after 4 wk of DFM administration. There was no effect on other fermentation parameters or on the bacterial, archaeal, and protozoal numbers monitored by quantitative PCR. However, denaturing gradient gel electrophoresis profiles indicated changes in bacterial and archaeal diversity in the and groups. Although added bacteria were unable to permanently colonize the rumen, had a greater 24-h survival rate than the others, implying that the persistence of DFM may be important for modulating ruminal traits of interest. These results suggest that bacterial DFM used in this trial were able to modify CH emissions, although correlated changes in other ruminal parameters studied were minor.

  2. Characterization of bacterial knot disease caused by Pseudomonas savastanoi pv. savastanoi on pomegranate (Punica granatum L.) trees: a new host of the pathogen.

    Science.gov (United States)

    Bozkurt, I A; Soylu, S; Mirik, M; Ulubas Serce, C; Baysal, Ö

    2014-11-01

    This study aimed to isolate and identify the causal organism causing hyperplastic outgrowths (knots) on stems and branches of pomegranate trees in the Eastern Mediterranean region of Turkey. Bacterial colonies were isolated from young knots on plates containing selective nutrient media. Biochemical tests, fatty acid analysis and PCR were performed to identify possible causal disease agent. Representative isolates were identified as Pseudomonas.pv.savastanoi (Psv) using biochemical tests, fatty acid profiling and PCR. Following inoculation of pomegranate plants (cv. hicaz) with bacterial suspensions, 25 of 54 bacterial isolates caused typical knots at the site of inoculation. PCR analysis, using specific primer for Psv, generated a single amplicon from all isolates. The similarity of the sequence of Turkish pomegranate isolate was 99% similar to the corresponding gene sequences of Psv in the databases. Based on symptoms, biochemical, molecular, pathogenicity tests and sequence analyses, the disease agent of knots observed on the pomegranate trees is Psv. To the best of our knowledge, this research has revealed pomegranate as a natural host of Psv, which extends the list of host plant species affected by the pathogen in the world and Turkey. Pomegranate trees were affected by the disease with outgrowths (galls or knot) disease. Currently, there is no published study on disease agent(s) causing the galls or knots on pomegranate trees in worldwide. Bacterial colonies were isolated from young knots. The causal agent of the knot Pseudomonas savastanoi pv.savastanoi (Psv) was identified based on symptoms, biochemical, molecular methods, pathogenicity tests and sequence analysis. To the best of our knowledge, this is the first report of Psv on pomegranate as a natural host, which extends the growing list of plant species affected by this bacterium in the world and Turkey. © 2014 The Society for Applied Microbiology.

  3. Correlation of particular bacterial PCR-denaturing gradient gel electrophoresis patterns with bovine ruminal fermentation parameters and feed efficiency traits.

    Science.gov (United States)

    Hernandez-Sanabria, Emma; Guan, Le Luo; Goonewardene, Laksiri A; Li, Meiju; Mujibi, Denis F; Stothard, Paul; Moore, Stephen S; Leon-Quintero, Monica C

    2010-10-01

    The influence of rumen microbial structure and functions on host physiology remains poorly understood. This study aimed to investigate the interaction between the ruminal microflora and the host by correlating bacterial diversity with fermentation measurements and feed efficiency traits, including dry matter intake, feed conversion ratio, average daily gain, and residual feed intake, using culture-independent methods. Universal bacterial partial 16S rRNA gene products were amplified from ruminal fluid collected from 58 steers raised under a low-energy diet and were subjected to PCR-denaturing gradient gel electrophoresis (DGGE) analysis. Multivariate statistical analysis was used to relate specific PCR-DGGE bands to various feed efficiency traits and metabolites. Analysis of volatile fatty acid profiles showed that butyrate was positively correlated with daily dry matter intake (P residual feed intake (P energy diet. This is the first study correlating PCR-DGGE bands representing specific bacteria to metabolites in the bovine rumen and to host feed efficiency traits.

  4. Endophytic Colonization of Potato (Solanum tuberosum L.) by a Novel Competent Bacterial Endophyte, Pseudomonas putida Strain P9, and Its Effect on Associated Bacterial Communities

    NARCIS (Netherlands)

    Andreote, F.D.; Araujo, W.L.; Azevedo, J.L.; Elsas, van J.D.; Rocha, da U.N.; Overbeek, van L.S.

    2009-01-01

    Pseudomonas putida strain P9 is a novel competent endophyte from potato. P9 causes cultivar-dependent suppression of Phytophthora infestans. Colonization of the rhizoplane and endosphere of potato plants by P9 and its rifampin-resistant derivative P9R was studied. The purposes of this work were to

  5. Endophytic colonization of potato (Solanum tuberosum L.) by a novel competent bacterial endophyte, Pseudomonas putida Strain P9, and its effect on associated bacterial communities

    NARCIS (Netherlands)

    Andreote, F.D; De Araujo, W.L.; de Azevedo, J.L.; van Elsas, J.D.; Nunes da Rocha, U.; van Overbeek, L.S.

    2009-01-01

    Pseudomonas putida strain P9 is a novel competent endophyte from potato. P9 causes cultivar-dependent suppression of Phytophthora infestans. Colonization of the rhizoplane and endosphere of potato plants by P9 and its rifampin-resistant derivative P9R was studied. The purposes of this work were to

  6. Synthetic furanones inhibit quorum-sensing and enhance bacterial clearance in Pseudomonas aeruginosa lung infection in mice

    DEFF Research Database (Denmark)

    Wu, H; Song, Z; Hentzer, M

    2004-01-01

    INTRODUCTION: Antibiotics are used to treat bacterial infections by killing the bacteria or inhibiting their growth, but resistance to antibiotics can develop readily. The discovery that bacterial quorum-sensing regulates bacterial virulence as well as the formation of biofilms opens up new ways...

  7. Synthetic furanones inhibit quorum-sensing and enhance bacterial clearance in Pseudomonas aeruginosa lung infection in mice

    DEFF Research Database (Denmark)

    Wu, H.; Song, Z.; Hentzer, Morten

    2004-01-01

    Introduction: Antibiotics are used to treat bacterial infections by killing the bacteria or inhibiting their growth, but resistance to antibiotics can develop readily. The discovery that bacterial quorum-sensing regulates bacterial virulence as well as the formation of biofilms opens up new ways...

  8. Bacterial Community Dynamics during Swine Fermentation Using Starch as a Substrate with Different Feed Additives for Odor Reduction

    Directory of Open Access Journals (Sweden)

    Md. J. Alam

    2012-05-01

    Full Text Available The experiment was conducted by in vitro fermentation and bacterial community analysis to investigate the reduction of odorous compounds in response to the use of feed additives (FA during carbohydrate overload in growing pigs. Soluble starch at 1% (control and various FA at 0.1% Ginseng meal (FA1; Persimmon leaf (FA2; Gingko nut (FA3 and Oregano lippia (FA4 were added to fecal slurry and incubated anaerobically for 12 and 24 h. In vitro parameters and microbial diversity of the dominant bacteria following fermentation were analyzed using Denaturing Gradient Gel Electrophoresis (DGGE, band cloning and sequencing of the V3 region. Results showed that total gas production increased with the advancement of incubation (p<0.05. pH values of FAs and control groups were decreased except the FA4 group which increased somewhat from 12 to 24 h (p<0.05. Ammonia nitrogen (NH3-N and H2S gas concentrations were comparatively lower in both stages in FA4 treatment than in the other groups (p<0.05. Hence, NH3-N concentrations in liquid phases were increased (p<0.05 from 12 to 24 h, but the trend was lowest in FA4 than in the other groups at both stages. The total VFA production was comparatively lower and butyrate levels were moderate in FA4 group than in the the other groups during both stages (p<0.05. Indirect odor-reducing compounds such as NO2, NO3 and SO4 concentrations were higher in the FA4 and FA3 than in the other groups at 24 h (p<0.05. After fermentation, ten dominant bands appeared, six of which appeared in all samples and four in only the FA4 treated group. The total number of DGGE bands and diversity was higher in the FA4-group compared to other groups. Additionally, similarity indices were lowest (71% in the FA4, which represented a different bacterial community compared with the other groups. These findings indicate that NH3-N, H2S and VFA production was minimal, and pH was also better in the FA4 group than in the other groups. Furthermore, the

  9. Effects of Ensiling Fermentation and Aerobic Deterioration on the Bacterial Community in Italian Ryegrass, Guinea Grass, and Whole-crop Maize Silages Stored at High Moisture Content

    Science.gov (United States)

    Li, Yanbing; Nishino, Naoki

    2013-01-01

    The effects of storage period and aerobic deterioration on the bacterial community were examined in Italian ryegrass (IR), guinea grass (GG), and whole-crop maize (WM) silages. Direct-cut forages were stored in a laboratory silo for 3, 7, 14, 28, 56, and 120 d without any additives; live counts, content of fermentation products, and characteristics of the bacterial community were determined. 2,3-Butanediol, acetic acid, and lactic acid were the dominant fermentation products in the IR, GG, and WM silages, respectively. The acetic acid content increased as a result of prolonged ensiling, regardless of the type of silage crop, and the changes were distinctively visible from the beginning of GG ensiling. Pantoea agglomerans, Rahnella aquatilis, and Enterobacter sp. were the major bacteria in the IR silage, indicating that alcoholic fermentation may be due to the activity of enterobacteria. Staphylococcus sciuri and Bacillus pumilus were detected when IR silage was spoiled, whereas between aerobically stable and unstable silages, no differences were seen in the bacterial community at silo opening. Lactococcus lactis was a representative bacterium, although acetic acid was the major fermentation product in the GG silage. Lactobacillus plantarum, Lactobacillus brevis, and Morganella morganii were suggested to be associated with the increase in acetic acid due to prolonged storage. Enterobacter cloacae appeared when the GG silage was spoiled. In the WM silage, no distinctive changes due to prolonged ensiling were seen in the bacterial community. Throughout the ensiling, Weissella paramesenteroides, Weissella confusa, and Klebsiella pneumoniae were present in addition to L. plantarum, L. brevis, and L. lactis. Upon deterioration, Acetobacter pasteurianus, Klebsiella variicola, Enterobacter hormaechei, and Bacillus gibsonii were detected. These results demonstrate the diverse bacterial community that evolves during ensiling and aerobic spoilage of IR, GG, and WM silages

  10. First report of the crucifer pathogen Pseudomonas cannabina pv. alisalensis causing bacterial blight on radish (Raphanus sativus) in Germany

    Science.gov (United States)

    Pseudomonas cannabina pv. alisalensis is a severe pathogen of crucifers across the U.S. We compared a strain isolated from diseased radish (Raphanus sativus) in Germany to pathotypes and additional strains of P. cannabina pv. alisalensis and P. syringae pv. maculicola. We demonstrated that the patho...

  11. Anti-Pseudomonas aeruginosa IgY antibodies augment bacterial clearance in a murine pneumonia model

    DEFF Research Database (Denmark)

    Thomsen, K.; Christophersen, L.; Bjarnsholt, T.

    2016-01-01

    Background: Oral prophylactic therapy by gargling with pathogen-specific egg yolk immunoglobulins (IgY) may reduce the initial airway colonization with Pseudomonas aeruginosa in cystic fibrosis (CF) patients. IgY antibodies impart passive immunization and we investigated the effects of anti...

  12. Microtus species as new herbivorous laboratory animals: reproduction; bacterial flora and fermentation in the digestive tracts; and nutritional physiology.

    Science.gov (United States)

    Kudo, H; Oki, Y

    1984-05-01

    In a study of the possible introduction of Japanese field vole (Microtus montebelli ) and Hungarian voles (M. arvalis) as herbivorous experimental animals, the following biological characteristics were investigated: breeding and reproductive performance; bacterial flora and fermentation in the digestive tracts; and nutritional physiology. The animals are polyestrus , show postpartum estrus on the day of parturition, and there is little or no delay in implantation due to lactation, especially in M. arvalis. On examination of vaginal smears, Japanese field vole did not show any definite pattern, whereas most Hungarian voles showed 6- to 18- day cycles. From the esophageal sac of voles fed rations with a high fiber content, cellulolytic bacteria similar to Ruminococcus albus, Ruminococcus flavefaciens , and Bacteroides succinogenes were isolated. More than 1 000 000/g anaerobic bacteria were present in the esophageal sac and the pattern and the types of bacteria resembled those found in the rumen. Gastric fermentation took place in the esophageal sac. The pH and total VFAs were much smaller in the fundic and pyloric regions of the stomach than in the esophageal sac. Acetic and lactic acids were the major fermentation products in the esophageal sac. Following deficiency or lowering of the cellulose decomposing abilities, a decrease of VFAs and an increase in lactic acid production in the esophageal sac were observed. These effects resulted in high glucose, FFA and ketone bodies in the blood, and a higher incidence of glucosuria. Diabetes induced by administrations of drugs such as alloxan, streptozotocin and phloridzin were compared using Microtus and mice. Microtus had low sensitivity to alloxan but high sensitivity to streptozotocin. The influence of monensin on Microtus was also investigated by using diets containing 20 and 80 mg/kg monensin. Diets containing 80 mg/kg monensin led to 50 % mortality in 7 weeks and growth was hindered. Gas production from the

  13. Butanol fermentation.

    Science.gov (United States)

    Schiel-Bengelsdorf, Bettina; Montoya, José; Linder, Sonja; Dürre, Peter

    2013-01-01

    This review provides an overview on bacterial butanol production and recent developments concerning strain improvement, newly built butanol production plants, and the importance of alternative substrates, especially lignocellulosic hydrolysates. The butanol fermentation using solventogenic clostridial strains, particularly Clostridium acetobutylicum, is a very old industrial process (acetone-butanol-ethanol-ABE fermentation). The genome of this organism has been sequenced and analysed, leading to important improvements in rational strain construction. As the traditional ABE fermentation process is economically unfavourable, novel butanol production strains are being developed. In this review, some newly engineered solvent-producing Clostridium strains are described and strains of which sequences are available are compared with C. acetobutylicum. Furthermore, the past and present of commercial butanol fermentation are presented, including active plants and companies. Finally, the use of biomass as substrate for butanol production is discussed. Some advances concerning processing of biomass in a biorefinery are highlighted, which would allow lowering the price of the butanol fermentation process at industrial scale.

  14. Use of PCR-DHPLC with fluorescence detection for the characterization of the bacterial diversity during cassava (Manihot esculenta Crantz) fermentation.

    Science.gov (United States)

    Kodama, C S; Cuadros-Orellana, S; Bandeira, C H M M; Graças, D A; Santos, A S; Silva, A

    2014-02-28

    Denaturing high-performance liquid chromatography (DHPLC) has been described as a suitable method to study DNA polymorphisms. Here, cassava (Manihot esculenta Crantz) fermentation liquor was examined using DHPLC analysis to characterize the bacterial diversity during the fermentation process. GC-clamped amplicons corresponding to a variable region of the bacterial community 16S rDNA were synthesized using polymerase chain reaction (PCR) and then resolved on a base-composition basis using preparative DHPLC. Eluate fractions were collected at random and used as a source of whole community DNA that could be used to determine the bacterial diversity. As a first approach, GC-clamps were removed from the eluted DNA fragments using PCR to avoid the possible bias these clamps could cause during the construction of clone libraries. As a second approach, a clone library of each eluate sample was constructed, preserving the GC-clamps of the DNA fragments. The first approach generated 132 bacterial rDNA sequences with an average size of 200 bp, 45% of which had similarity to unculturable or non-classified bacteria. The second approach produced 194 sequences identified as Proteobacteria (48%), uncultured or non-classified environmental bacteria (40%) and Firmicutes (12%). We detected a remarkably greater bacterial diversity using the first approach than the second approach. The DHPLC-PCR method allowed for the fast and non-laborious detection of a vast bacterial diversity that was associated with cassava fermentation, and we conclude that it is a promising alternative for the characterization of the overall microbial diversity in complex samples.

  15. Fermentative profile and bacterial diversity of corn silages inoculated with new tropical lactic acid bacteria.

    Science.gov (United States)

    Santos, A O; Ávila, C L S; Pinto, J C; Carvalho, B F; Dias, D R; Schwan, R F

    2016-02-01

    This study aimed to evaluate the effects of inoculation of strains of lactic acid bacteria (LAB) isolated from sugarcane grown in a Brazil on the quality of corn silage. Three strains of Lactobacillus buchneri (UFLA SLM11, UFLA SLM103 and UFLA SLM108), five strains of Lactobacillus plantarum (UFLA SLM08, UFLA SLM41, UFLA SLM45, UFLA SLM46 and UFLA SLM105), and one strain of Leuconostoc mesenteroides (UFLA SLM06) were evaluated at 0, 10, 30, 60 and 90 day after inoculating corn forage. The inoculation of the LAB strains did not influence the chemical composition of the silage, but pH, acetic acid and 1,2-propanediol were affected by treatment. The silages inoculated with UFLA SLM11 and SLM108 contained the lowest yeast and filamentous fungi counts during fermentation. Bacteria belonging to the Enterobacteriaceae family, Clostridium genus were detected in the silages inoculated with Lact. buchneri UFLA SLM 11, 103 and 108, as shown by DGGE analysis. Silages inoculated with Lact. buchneri UFLA SLM 11 showed higher aerobic stability. The Lact. buchneri UFLA SLM11 strain was considered promising as a starter culture or inoculant for corn silages. The selection of microbial inoculants for each crop promotes improvement of silage quality. Studies on the chemical and microbiological characteristics of silage provide useful information for improving ensiling techniques. © 2015 The Society for Applied Microbiology.

  16. Rumen microbial and fermentation characteristics are affected differently by bacterial probiotic supplementation during induced lactic and subacute acidosis in sheep

    Science.gov (United States)

    2012-01-01

    Background Ruminal disbiosis induced by feeding is the cause of ruminal acidosis, a digestive disorder prevalent in high-producing ruminants. Because probiotic microorganisms can modulate the gastrointestinal microbiota, propionibacteria- and lactobacilli-based probiotics were tested for their effectiveness in preventing different forms of acidosis. Results Lactic acidosis, butyric and propionic subacute ruminal acidosis (SARA) were induced by feed chalenges in three groups of four wethers intraruminally dosed with wheat, corn or beet pulp. In each group, wethers were either not supplemented (C) or supplemented with Propionibacterium P63 alone (P) or combined with L. plantarum (Lp + P) or L. rhamnosus (Lr + P). Compared with C, all the probiotics stimulated lactobacilli proliferation, which reached up to 25% of total bacteria during wheat-induced lactic acidosis. This induced a large increase in lactate concentration, which decreased ruminal pH. During the corn-induced butyric SARA, Lp + P decreased Prevotella spp. proportion with a concomitant decrease in microbial amylase activity and total volatile fatty acids concentration, and an increase in xylanase activity and pH. Relative to the beet pulp-induced propionic SARA, P and Lr + P improved ruminal pH without affecting the microbial or fermentation characteristics. Regardless of acidosis type, denaturing gradient gel electrophoresis revealed that probiotic supplementations modified the bacterial community structure. Conclusion This work showed that the effectiveness of the bacterial probiotics tested depended on the acidosis type. Although these probiotics were ineffective in lactic acidosis because of a deeply disturbed rumen microbiota, some of the probiotics tested may be useful to minimize the occurrence of butyric and propionic SARA in sheep. However, their modes of action need to be further investigated. PMID:22812531

  17. Rumen microbial and fermentation characteristics are affected differently by bacterial probiotic supplementation during induced lactic and subacute acidosis in sheep.

    Science.gov (United States)

    Lettat, Abderzak; Nozière, Pierre; Silberberg, Mathieu; Morgavi, Diego P; Berger, Claudette; Martin, Cécile

    2012-07-19

    Ruminal disbiosis induced by feeding is the cause of ruminal acidosis, a digestive disorder prevalent in high-producing ruminants. Because probiotic microorganisms can modulate the gastrointestinal microbiota, propionibacteria- and lactobacilli-based probiotics were tested for their effectiveness in preventing different forms of acidosis. Lactic acidosis, butyric and propionic subacute ruminal acidosis (SARA) were induced by feed chalenges in three groups of four wethers intraruminally dosed with wheat, corn or beet pulp. In each group, wethers were either not supplemented (C) or supplemented with Propionibacterium P63 alone (P) or combined with L. plantarum (Lp + P) or L. rhamnosus (Lr + P). Compared with C, all the probiotics stimulated lactobacilli proliferation, which reached up to 25% of total bacteria during wheat-induced lactic acidosis. This induced a large increase in lactate concentration, which decreased ruminal pH. During the corn-induced butyric SARA, Lp + P decreased Prevotella spp. proportion with a concomitant decrease in microbial amylase activity and total volatile fatty acids concentration, and an increase in xylanase activity and pH. Relative to the beet pulp-induced propionic SARA, P and Lr + P improved ruminal pH without affecting the microbial or fermentation characteristics. Regardless of acidosis type, denaturing gradient gel electrophoresis revealed that probiotic supplementations modified the bacterial community structure. This work showed that the effectiveness of the bacterial probiotics tested depended on the acidosis type. Although these probiotics were ineffective in lactic acidosis because of a deeply disturbed rumen microbiota, some of the probiotics tested may be useful to minimize the occurrence of butyric and propionic SARA in sheep. However, their modes of action need to be further investigated.

  18. Rumen microbial and fermentation characteristics are affected differently by bacterial probiotic supplementation during induced lactic and subacute acidosis in sheep

    Directory of Open Access Journals (Sweden)

    Lettat Abderzak

    2012-07-01

    Full Text Available Abstract Background Ruminal disbiosis induced by feeding is the cause of ruminal acidosis, a digestive disorder prevalent in high-producing ruminants. Because probiotic microorganisms can modulate the gastrointestinal microbiota, propionibacteria- and lactobacilli-based probiotics were tested for their effectiveness in preventing different forms of acidosis. Results Lactic acidosis, butyric and propionic subacute ruminal acidosis (SARA were induced by feed chalenges in three groups of four wethers intraruminally dosed with wheat, corn or beet pulp. In each group, wethers were either not supplemented (C or supplemented with Propionibacterium P63 alone (P or combined with L. plantarum (Lp + P or L. rhamnosus (Lr + P. Compared with C, all the probiotics stimulated lactobacilli proliferation, which reached up to 25% of total bacteria during wheat-induced lactic acidosis. This induced a large increase in lactate concentration, which decreased ruminal pH. During the corn-induced butyric SARA, Lp + P decreased Prevotella spp. proportion with a concomitant decrease in microbial amylase activity and total volatile fatty acids concentration, and an increase in xylanase activity and pH. Relative to the beet pulp-induced propionic SARA, P and Lr + P improved ruminal pH without affecting the microbial or fermentation characteristics. Regardless of acidosis type, denaturing gradient gel electrophoresis revealed that probiotic supplementations modified the bacterial community structure. Conclusion This work showed that the effectiveness of the bacterial probiotics tested depended on the acidosis type. Although these probiotics were ineffective in lactic acidosis because of a deeply disturbed rumen microbiota, some of the probiotics tested may be useful to minimize the occurrence of butyric and propionic SARA in sheep. However, their modes of action need to be further investigated.

  19. Assessing the impact of various ensilage factors on the fermentation of grass silage using conventional culture and bacterial community analysis techniques.

    Science.gov (United States)

    McEniry, J; O'Kiely, P; Clipson, N J W; Forristal, P D; Doyle, E M

    2010-05-01

    Grass silage is an important ruminant feedstuff on farms during winter. The ensilage of grass involves a natural lactic acid bacterial fermentation under anaerobic conditions, and numerous factors can influence the outcome of preservation. The aim of this study was to investigate the effect of dry matter concentration, ensiling system, compaction and air infiltration on silage bacterial community composition. The impact of these factors was examined using conventional methods of microbial analysis and culture-independent Terminal Restriction Fragment Length Polymorphism (T-RFLP). Silage fermentation was restricted in herbage with a high dry matter concentration, and this was reflected in a shift in the bacterial population present. In contrast, ensiling system had little effect on bacterial community composition. Air infiltration, in the absence of compaction, altered silage bacterial community composition and silage pH. Dry matter concentration and the absence of compaction were the main factors affecting silage microbial community composition, and this was reflected in both the conventional culture-based and T-RFLP data. T-RFLP proved a useful tool to study the factors affecting ensilage. Apart from monitoring the presence or absence of members of the population, shifts in the relative presence of members could be monitored.

  20. Effect of bacterial components of mixed culture supernatants of planktonic and biofilm Pseudomonas aeruginosa with commensal Escherichia coli on the neutrophil response in vitro.

    Science.gov (United States)

    Maslennikova, Irina L; Kuznetsova, Marina V; Nekrasova, Irina V; Shirshev, Sergei V

    2017-11-30

    Pseudomonas aeruginosa (PA) responsible for acute and chronic infections often forms a well-organized bacterial population with different microbial species including commensal strains of Escherichia coli. Bacterial extracellular components of mixed culture can modulate the influence of bacteria on the neutrophil functions. The objective of this study was to compare the effect of pyocyanin, pyoverdine, LPS, exopolysaccharide of single species and mixed culture supernatants of PA strains and E. coli K12 on microbicidal, secretory activity of human neutrophils in vitro. Bacterial components of E. coli K12 in mixed supernatants with 'biofilm' PA strains (PA ATCC, PA BALG) enhanced short-term microbicidal mechanisms and inhibited neutrophil secretion delayed in time. The influence of 'planktonic' PA (PA 9-3) exometabolites in mixed culture is almost mimicked by E. coli K12 effect on functional neutrophil changes. This investigation may help to understand some of the mechanisms of neutrophil response to mixed infections of different PA with other bacteria species. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Combination of culture-independent and culture-dependent molecular methods for the determination of bacterial community of iru, a fermented Parkia biglobosa seeds.

    Directory of Open Access Journals (Sweden)

    Gbenga Adedeji Adewumi

    2013-01-01

    Full Text Available In this study, bacterial composition of iru produced by natural, uncontrolled fermentation of Parkia biglobosa seeds was assessed using culture-independent method in combination with culture-based genotypic typing techniques. PCR-denaturing gradient gel electrophoresis (DGGE revealed similarity in DNA fragments with the two DNA extraction methods used and confirmed bacterial diversity in the sixteen iru samples from different production regions. DNA sequencing of the highly variable V3 region of the 16S rRNA genes obtained from PCR-DGGE identified species related to Bacillus subtilis as consistent bacterial species in the fermented samples, while other major bands were identified as close relatives of Staphylococcus vitulinus, Morganella morganii, B. thuringiensis, Staphylococcus saprophyticus, Tetragenococcus halophilus, Ureibacillus thermosphaericus, Brevibacillus parabrevis, Salinicoccus jeotgali, Brevibacterium sp. and Uncultured bacteria clones. Bacillus species were cultured as potential starter cultures and clonal relationship of different isolates determined using amplified ribosomal DNA restriction analysis (ARDRA combined with 16S-23S rRNA gene internal transcribed spacer (ITS PCR amplification, restriction analysis (ITS-PCR-RFLP and randomly amplified polymorphic DNA (RAPD-PCR. This further discriminated Bacillus subtilis and its variants from food-borne pathogens such as Bacillus cereus and suggested the need for development of controlled fermentation processes and good manufacturing practices (GMP for iru production to achieve product consistency, safety quality and improved shelf life.

  2. Insight into the bacterial diversity of fermentation woad dye vats as revealed by PCR-DGGE and pyrosequencing.

    Science.gov (United States)

    Milanović, Vesna; Osimani, Andrea; Taccari, Manuela; Garofalo, Cristiana; Butta, Alessandro; Clementi, Francesca; Aquilanti, Lucia

    2017-07-01

    The bacterial diversity in fermenting dye vats with woad (Isatis tinctoria L.) prepared and maintained in a functional state for approximately 12 months was examined using a combination of culture-dependent and -independent PCR-DGGE analyses and next-generation sequencing of 16S rRNA amplicons. An extremely complex ecosystem including taxa potentially contributing to both indigo reduction and formation, as well as indigo degradation was found. PCR-DGGE analyses revealed the presence of Paenibacillus lactis, Sporosarcina koreensis, Bacillus licheniformis, and Bacillus thermoamylovorans, while Bacillus thermolactis, Bacillus pumilus and Bacillus megaterium were also identified but with sequence identities lower than 97%. Dominant operational taxonomic units (OTUs) identified by pyrosequencing included Clostridium ultunense, Tissierella spp., Alcaligenes faecalis, Erysipelothrix spp., Enterococcus spp., Virgibacillus spp. and Virgibacillus panthothenicus, while sub-dominant OTUs included clostridia, alkaliphiles, halophiles, bacilli, moderately thermophilic bacteria, lactic acid bacteria, Enterobacteriaceae, aerobes, and even photosynthetic bacteria. Based on the current knowledge of indigo-reducing bacteria, it is considered that indigo-reducing bacteria constituted only a small fraction in the unique microcosm detected in the natural indigo dye vats.

  3. A biogeochemical and genetic survey of acetylene fermentation by environmental samples and bacterial isolates

    Science.gov (United States)

    Miller, Laurence G.; Baesman, Shaun M.; Kirshtein, Julie; Voytek, Mary A.; Oremland, Ronald S.

    2013-01-01

    Anoxic samples (sediment and groundwater) from 13 chemically diverse field sites were assayed for their ability to consume acetylene (C2H2). Over incubation periods ranging from ˜ 10 to 80 days, selected samples from 7 of the 13 tested sites displayed significant C2H2 removal. No significant formation of ethylene was noted in these incubations; therefore, C2H2 consumption could be attributed to acetylene hydratase (AH) rather than nitrogenase activity. This putative AH (PAH) activity was observed in only 21% of the total of assayed samples, while amplification of AH genes from extracted DNA using degenerate primers derived from Pelobacter acetylenicus occurred in even fewer (9.8%) samples. Acetylene-fermenting bacteria were isolated as a pure culture from the sediments of a tidal mudflat in San Francisco Bay (SFB93) and as an enrichment culture from freshwater Searsville Lake (SV7). Comparison of 16S rDNA clone libraries revealed that SFB93 was closely related to P. carbolinicus, while SV7 consisted of several unrelated bacteria. AH gene was amplified from SFB93 but not SV7. The inability of the primers to generate amplicons in the SV7 enrichment, as well as from several of the environmental samples that displayed PAH activity, implied that either the primers were too highly constrained in their specificity or that there was a different type of AH gene in these environmental samples than occurs in P. acetylenicus. The significance of this work with regard to the search for life in the outer Solar System, where C2HL2 is abundant, is discussed.

  4. ABILITY OF BACTERIAL CONSORTIUM: Bacillus coagulans, Bacilus licheniformis, Bacillus pumilus, Bacillus subtilis, Nitrosomonas sp. and Pseudomonas putida IN BIOREMEDIATION OF WASTE WATER IN CISIRUNG WASTE WATER TREATMENT PLANT

    Directory of Open Access Journals (Sweden)

    Ratu SAFITRI

    2015-10-01

    Full Text Available This study was conducted in order to determine the ability of bacterial consortium: Bacillus coagulans, Bacilus licheniformis, Bacillus pumilus, Bacillus subtilis, Nitrosomonas sp., and Pseudomonas putida in bioremediation of wastewater origin Cisirung WWTP. This study uses an experimental method completely randomized design (CRD, which consists of two treatment factors (8x8 factorial design. The first factor is a consortium of bacteria (K, consisting of 8 level factors (k1, k2, k3, k4, k5, k6, k7, and k8. The second factor is the time (T, consisting of a 7 level factors (t0, t1, t2, t3, t4, t5, t6, and t7. Test parameters consist of BOD (Biochemical Oxygen Demand, COD (Chemical Oxygen Demand, TSS (Total Suspended Solid, Ammonia and Population of Microbes during bioremediation. Data were analyzed by ANOVA, followed by Duncan test. The results of this study showed that the consortium of Bacillus pumilus, Bacillus subtilis, Bacillus coagulans, Nitrosomonas sp., and Pseudomonas putida with inoculum concentration of 5% (k6 is a consortium of the most effective in reducing BOD 71.93%, 64.30% COD, TSS 94.85%, and 88.58% of ammonia.

  5. Thienopyrimidine-type compounds protect Arabidopsis plants against the hemibiotrophic fungal pathogen Colletotrichum higginsianum and bacterial pathogen Pseudomonas syringae pv. maculicola.

    Science.gov (United States)

    Narusaka, Mari; Narusaka, Yoshihiro

    2017-03-04

    Plant activators activate systemic acquired resistance-like defense responses or induced systemic resistance, and thus protect plants from pathogens. We screened a chemical library composed of structurally diverse small molecules. We isolated six plant immune-inducing thienopyrimidine-type compounds and their analogous compounds. It was observed that the core structure of thienopyrimidine plays a role in induced resistance in plants. Furthermore, we highlight the protective effect of thienopyrimidine-type compounds against both hemibiotrophic fungal pathogen, Colletotrichum higginsianum, and bacterial pathogen, Pseudomonas syringae pv. maculicola, in Arabidopsis thaliana. We suggest that thienopyrimidine-type compounds could be potential lead compounds as novel plant activators, and can be useful and effective agrochemicals against various plant diseases.

  6. [High efficiency of L-glutamine production by coupling genetic engineered bacterial glutamine synthetase with yeast alcoholic fermentation system].

    Science.gov (United States)

    Chen, Qun-Ying; Chen, Guo-An; Xue, Bin; Zhang, Xian-Jiu; Yin, Zhi-Min

    2004-05-01

    Glutamine is an important conditionally necessary amino acid in human body. The effort is to establish a new and high efficient L-glutamine production system instead of traditional fermentaion. In this paper, high efficiency of L-glutamine production is obtained by coupling genetic engineered bacterial glutamine synthetase (GS) with yeast alcoholic fermentation system. Glutamine Synthetase gene (glnA) was amplified from Bacillus subtilis genomic DNA with primers designed according to sequences reported in EMBL data bank, then it was inserted into expression vector PET28b, the sequence of glnA was proved to be the same as that reported in the data bank by DNA sequencing. After transformation of this recombinant plasmid PET28b-glnA into BL-21 (DE3) strain, Lactose and IPTG were used to induce GS expression at 37 degrees C separately. Both of them can induce GS expression efficiently. The induced protein is proved to be soluble and occupies about 80% of the total proteins by SDS-PAGE analysis. The soluble GS was purified by Ni2+ chelating sepharose colum. After purification, the purified enzyme was proved active. Results reveal that the optmum temperature of this enzyme is 60 degrees C and optmum pH is 6.5 in biosynthetic reaction by using glutamate, ammonium choloride and ATP as substrates. After induction, the enzyme activity in crude extract of BL-21/PET28b-glnA is 83 times higher than that of original BL-21 extract. Mn2+ can obviously increase the activity and stability of this enzyme. Experiments show that the transformation efficiency of glutamate to glutamine is more than 95%. Because of the high cost from ATP, a system coupling GS with yeast for ATP regenaration was established. In this system, GS utilizes ATP released by yeast fermentation to synthesize L-glutamine. Yeast was treated by 2% toluence to increase its permeability and a yeast named YC001 with high yield of glutamine by coupling with recombinant GS was obtained. The good efficiency was achieved

  7. Effect of Phytogenic Feed Additives in Soybean Meal on Swine Fermentation for Odor Reduction and Bacterial Community Comparison

    Directory of Open Access Journals (Sweden)

    M. J. Alam

    2013-02-01

    Full Text Available The effect of different phytogenic feed additives on reducing odorous compounds in swine was investigated using in vitro fermentation and analyzed their microbial communities. Soybean meal (1% added with 0.1% different phytogenic feed additives (FA were in vitro fermented using swine fecal slurries and anaerobically incubated for 12 and 24 h. The phytogenic FAs used were red ginseng barn powder (Panax ginseng C. A. Meyer, FA1, persimmon leaf powder (Diospyros virginiana L., FA2, ginkgo leaf powder (Ginkgo biloba L., FA3, and oregano lippia seed oil extract (Lippia graveolens Kunth, OL, FA4. Total gas production, pH, ammonia-nitrogen (NH3-N, hydrogen sulfide (H2S, nitrite-nitrogen (NO2−-N, nitrate-nitrogen (NO3−-N, sulfate (SO4−−, volatile fatty acids (VFA and other metabolites concentration were determined. Microbial communities were also analyzed using 16S rRNA DGGE. Results showed that the pH values on all treatments increased as incubation time became longer except for FA4 where it decreased. Moreover, FA4 incubated for 12 and 24 h was not detected in NH3-N and H2S. Addition of FAs decreased (p<0.05 propionate production but increased (p<0.05 the total VFA production. Ten 16S rRNA DGGE bands were identified which ranged from 96 to 100% identity which were mostly isolated from the intestine. Similarity index showed three clearly different clusters: I (FA2 and FA3, II (Con and FA1, and III (FA4. Dominant bands which were identified closest to Eubacterium limosum (ATCC 8486T, Uncultured bacterium clone PF6641 and Streptococcus lutetiensis (CIP 106849T were present only in the FA4 treatment group and were not found in other groups. FA4 had a different bacterial diversity compared to control and other treatments and thus explains having lowest odorous compounds. Addition of FA4 to an enriched protein feed source for growing swine may effectively reduce odorous compounds which are typically associated with swine production.

  8. Polyamine is a critical determinant of Pseudomonas chlororaphis O6 for GacS-dependent bacterial cell growth and biocontrol capacity.

    Science.gov (United States)

    Park, Ju Yeon; Kang, Beom Ryong; Ryu, Choong-Min; Anderson, Anne J; Kim, Young Cheol

    2017-09-01

    The Gac/Rsm network regulates, at the transcriptional level, many beneficial traits in biocontrol-active pseudomonads. In this study, we used Phenotype MicroArrays, followed by specific growth studies and mutational analysis, to understand how catabolism is regulated by this sensor kinase system in the biocontrol isolate Pseudomonas chlororaphis O6. The growth of a gacS mutant was decreased significantly relative to that of the wild-type on ornithine and arginine, and on the precursor of these amino acids, N-acetyl-l-glutamic acid. The gacS mutant also showed reduced production of polyamines. Expression of the genes encoding arginine decarboxylase (speA) and ornithine decarboxylases (speC) was controlled at the transcriptional level by the GacS sensor of P. chlororaphis O6. Polyamine production was reduced in the speC mutant, and was eliminated in the speAspeC mutant. The addition of exogenous polyamines to the speAspeC mutant restored the in vitro growth inhibition of two fungal pathogens, as well as the secretion of three biological control-related factors: pyrrolnitrin, protease and siderophore. These results extend our knowledge of the regulation by the Gac/Rsm network in a biocontrol pseudomonad to include polyamine synthesis. Collectively, our studies demonstrate that bacterial polyamines act as important regulators of bacterial cell growth and biocontrol potential. © 2017 BSPP AND JOHN WILEY & SONS LTD.

  9. An antisense peptide nucleic acid against Pseudomonas aeruginosa inhibiting bacterial-induced inflammatory responses in the cystic fibrosis IB3-1 cellular model system.

    Science.gov (United States)

    Montagner, Giulia; Bezzerri, Valentino; Cabrini, Giulio; Fabbri, Enrica; Borgatti, Monica; Lampronti, Ilaria; Finotti, Alessia; Nielsen, Peter E; Gambari, Roberto

    2017-06-01

    Discovery of novel antimicrobial agents against Pseudomonas aeruginosa able to inhibit bacterial growth as well as the resulting inflammatory response is a key goal in cystic fibrosis research. We report in this paper that a peptide nucleic acid (PNA3969) targeting the translation initiation region of the essential acpP gene of P. aeruginosa, and previously shown to inhibit bacterial growth, concomitantly also strongly inhibits induced up-regulation of the pro-inflammatory markers IL-8, IL-6, G-CSF, IFN-γ, IP-10, MCP-1 and TNF-α in IB3-1 cystic fibrosis cells infected by P. aeruginosa PAO1. Remarkably, no effect on PAO1 induction of VEGF, GM-CSF and IL-17 was observed. Analogous experiments using a two base mis-match control PNA did not show such inhibition. Furthermore, no significant effects of the PNAs were seen on cell growth, apoptosis or secretome profile in uninfected IB3-1 cells (with the exception of a PNA-mediated up-regulation of PDGF, IL-17 and GM-CSF). Thus, we conclude that in cell culture an antimicrobial PNA against P. aeruginosa can inhibit the expression of pro-inflammatory cytokines otherwise induced by the infection. In particular, the effects of PNA-3969 on IL-8 gene expression are significant considering the key role of this protein in the cystic fibrosis inflammatory process exacerbated by P. aeruginosa infection. Copyright © 2017. Published by Elsevier B.V.

  10. Bacterial community composition and fermentation in the rumen of Xinjiang brown cattle (Bos taurus), Tarim red deer (Cervus elaphus yarkandensis), and Karakul sheep (Ovis aries).

    Science.gov (United States)

    Qian, Wenxi; Li, ZhiPeng; Ao, Weiping; Zhao, Guangyong; Li, Guangyu; Wu, JianPing

    2017-05-01

    The rumen microbiota plays a major role in the metabolism and absorption of indigestible food sources. Xinjiang brown cattle (Bos taurus), Tarim red deer (Cervus elaphus yarkandensis), and Karakul sheep (Ovis aries) are important ruminant species for animal husbandry in the Tarim Basin. However, the microbiota and rumen fermentation of these animals are poorly understood. Here, we apply high-throughput sequencing to examine the bacterial community in the rumen of cattle, red deer, and sheep and measured rumen fermentation products. Overall, 548 218 high-quality sequences were obtained and then classified into 6034 operational taxonomic units. Prevotella spp., Succiniclasticum spp., and unclassified bacteria within the families Succinivibrionaceae, Lachnospiraceae, and Veillonellaceae were the dominant bacteria in the rumen across the 3 hosts. Principal coordinate analysis identified significant differences in the bacterial communities across the 3 hosts. Pseudobutyrivibrio spp., Oscillospira spp., and Prevotella spp. were more prevalent in the rumen of the cattle, red deer, and sheep, respectively. Among the 3 hosts, the red deer rumen had the greatest amounts of acetate and butyrate and the lowest pH value. These results showed that Prevotella spp. are the dominant bacteria in the rumen of the cattle, red deer, and sheep, providing new insight into the rumen fermentation of ruminants distributed in the Tarim Basin.

  11. Comparison of PCR-DGGE and PCR-SSCP analysis for bacterial flora of Japanese traditional fermented fish products, aji-narezushi and iwashi-nukazuke.

    Science.gov (United States)

    An, Choa; Takahashi, Hajime; Kimura, Bon; Kuda, Takashi

    2010-08-30

    The bacterial flora of two Japanese traditional fermented fish products, aji-narezushi (salted and long-fermented horse mackerel (Trachurus japonicas) with rice) and iwashi-nukazuke (salted and long-fermented sardine (Sardinops melanostica) with rice bran), was analysed using non-culture-based polymerase chain reaction (PCR) denaturing gradient gel electrophoresis (DGGE) and culture-based PCR single-strand conformation polymorphism (SSCP) methods. Viable plate counts in aji-narezushi and iwashi-nukazuke were about 6.3-6.6 and 5.7-6.9 log colony-forming units g(-1) respectively. In the PCR-DGGE analysis, Lactobacillus acidipiscis was detected as the predominant bacterium in two of three aji-narezushi samples, while Lactobacillus versmoldensis was predominant in the third sample. By the PCR-SSCP method, Lb. acidipiscis and Lactobacillus plantarum were isolated as the predominant bacteria, while Lb. versmoldensis was not detected. The predominant bacterium in two of three iwashi-nukazuke samples was Tetragenococcus muriaticus, while Tetragenococcus halophilus was predominant in the third sample. The results suggest that the detection of some predominant lactic acid bacteria species in fermented fish by cultivation methods is difficult. Copyright (c) 2010 Society of Chemical Industry.

  12. The role of oral administration of oatmeal fermented by Lactobacillus reuteri R2LC on bacterial translocation after acute liver failure induced by subtotal liver resection in the rat.

    Science.gov (United States)

    Wang, X D; Soltesz, V; Molin, G; Andersson, R

    1995-02-01

    Previous experimental studies showed that a disturbed ecology of the enteric bacterial population might contribute to the occurrence of bacterial translocation from the gut in acute liver failure (ALF). In the present study the effects of oral administration of exogenous Lactobacillus reuteri R2LC and oat fiber on bacterial overgrowth and translocation and on enterocyte protein contents were investigated in rats with ALF induced by subtotal liver resection. The oatmeal soup base was anaerobically inoculated with L. reuteri R2LC and fermented for 15 h. The animals were then fed with fermented or unfermented oatmeal or saline daily for 6 days before the experimental procedure. The incidence of bacterial translocation to the systemic circulation was nil and 17% in rats subjected to sham operation with saline or 90% hepatectomy with fermented oatmeal, respectively, and 80-90% and 34-50% in rats subjected to hepatectomy with saline or unfermented oatmeal. One rat treated with fermented oatmeal had positive bacterial growth in mesenteric lymph nodes (MLN), which was significantly lower than in hepatectomized rats with saline or unfermented oatmeal (80-100% and 50-67%). No significant differences was demonstrable between hepatectomized animals with oral administration of fermented or unfermented oatmeal as compared with sham-operated rats. The number of anaerobic bacteria, Gram-negative anaerobes, and Lactobacillus decreased significantly, and the number of Escherichia coli increased in the distal small intestine and colon in hepatectomized animals with saline or unfermented oatmeal, as compared with animals subjected to sham operation or hepatectomy with fermented oatmeal. The occurrence of bacterial translocation from the gut in 90% hepatectomy-induced ALF could be prevented by fermented oatmeal, which implies possibilities for biologically balancing the enteric bacterial ecology.

  13. 'Pseudomonas saudiphocaensis' sp. nov., a new bacterial species isolated from currency notes collected during the Hajj pilgrimage in 2012 at Makkah, Saudi Arabia.

    Science.gov (United States)

    Azhar, E I; Papadioti, A; Bibi, F; Ashshi, A M; Raoult, D; Angelakis, E

    2017-01-01

    We report here the main characteristics of 'Pseudomonas saudiphocaensis' strain 20_BNT (CSUR P1224), a new species of the Pseudomonas genus that was isolated from currency notes collected during the Hajj pilgrimage in 2012 at Makkah, Saudi Arabia.

  14. Addition of citrus pulp and apple pomace in diets for dogs: influence on fermentation kinetics, digestion, faecal characteristics and bacterial populations.

    Science.gov (United States)

    Brambillasca, Sebastián; Britos, Alejandro; Deluca, Carolina; Fraga, Martín; Cajarville, Cecilia

    2013-12-01

    Fermentation kinetics, digestibility, faecal characteristics and bacterial populations (aerobes, anaerobes, lactobacilli, lactic acid bacteria, enterococci, coliforms and clostridia) of dog food mixed with citrus pulp and apple pomace were evaluated. The in vitro gas production of a pre-digested dog food mixed with 0, 30, 50 and 70 g/kg dry matter (DM) of citrus pulp or apple pomace was measured, and also an experiment with dogs fed the same dog food with or without the addition of 70 g/kg of either fresh citrus pulp or apple pomace was conducted. Gas production increased linearly (p citrus and apple was effective to stimulate the hindgut fermentation, but slightly depressed the digestion.

  15. Bacterial blight (Pseudomonas pisi Sackett) of peas in South Africa, with special reference to frost as a predisposing factor

    NARCIS (Netherlands)

    Boelema, B.H.

    1972-01-01

    In the beginning of the nineteen fifties bacterial blight caused much damage to pea crops in South Africa, particularly to those grown for seed production. A study has been made of the causal organism and the conditioning factors of the disease, special attention being paid to frost as a

  16. The relationship between instability of H2 production and compositions of bacterial communities within a dark fermentation fluidized-bed bioreactor.

    Science.gov (United States)

    Koskinen, Perttu E P; Kaksonen, Anna H; Puhakka, Jaakko A

    2007-07-01

    Microbial community composition dynamics was studied during H(2) fermentation from glucose in a fluidized-bed bioreactor (FBR) aiming at obtaining insight into the H(2) fermentation microbiology and factors resulting in the instability of biofilm processes. FBR H(2) production performance was characterised by an instable pattern of prompt onset of H(2) production followed by rapid decrease. Gradual enrichment of organisms increased the diversity of FBR attached and suspended-growth phase bacterial communities during the operation. FBR bacteria included potential H(2) producers, H(2) consumers and neither H(2) producers nor consumers, and those distantly related to any known organisms. The prompt onset of H(2) production was due to rapid growth of Clostridium butyricum (99-100%) affiliated strains after starting continuous feed. The proportion trend of C. butyricum in FBR attached and suspended-growth phase communities coincided with H(2) and butyrate production. High glucose loading rate favoured the H(2) production by Escherichia coli (100%) affiliated strain. Decrease in H(2) production, associated with a shift from acetate-butyrate to acetate-propionate production, was due to changes in FBR attached and suspended-growth phase bacterial community compositions. During the shift, organisms, including potential propionate producers, were enriched in the communities while the proportion trend of C. butyricum decreased. We suggest that the instability of H(2) fermentation in biofilm reactors is due to enrichment and efficient adhesion of H(2) consumers on the carrier and, therefore, biofilm reactors may not favour mesophilic H(2) fermentation. (c) 2006 Wiley Periodicals, Inc.

  17. Reproducible biofilm cultivation of chemostat-grown Escherichia coli and investigation of bacterial adhesion on biomaterials using a non-constant-depth film fermenter.

    Directory of Open Access Journals (Sweden)

    Claudia Lüdecke

    Full Text Available Biomaterials-associated infections are primarily initiated by the adhesion of microorganisms on the biomaterial surfaces and subsequent biofilm formation. Understanding the fundamental microbial adhesion mechanisms and biofilm development is crucial for developing strategies to prevent such infections. Suitable in vitro systems for biofilm cultivation and bacterial adhesion at controllable, constant and reproducible conditions are indispensable. This study aimed (i to modify the previously described constant-depth film fermenter for the reproducible cultivation of biofilms at non-depth-restricted, constant and low shear conditions and (ii to use this system to elucidate bacterial adhesion kinetics on different biomaterials, focusing on biomaterials surface nanoroughness and hydrophobicity. Chemostat-grown Escherichia coli were used for biofilm cultivation on titanium oxide and investigating bacterial adhesion over time on titanium oxide, poly(styrene, poly(tetrafluoroethylene and glass. Using chemostat-grown microbial cells (single-species continuous culture minimized variations between the biofilms cultivated during different experimental runs. Bacterial adhesion on biomaterials comprised an initial lag-phase I followed by a fast adhesion phase II and a phase of saturation III. With increasing biomaterials surface nanoroughness and increasing hydrophobicity, adhesion rates increased during phases I and II. The influence of materials surface hydrophobicity seemed to exceed that of nanoroughness during the lag-phase I, whereas it was vice versa during adhesion phase II. This study introduces the non-constant-depth film fermenter in combination with a chemostat culture to allow for a controlled approach to reproducibly cultivate biofilms and to investigate bacterial adhesion kinetics at constant and low shear conditions. The findings will support developing and adequate testing of biomaterials surface modifications eventually preventing

  18. Reproducible Biofilm Cultivation of Chemostat-Grown Escherichia coli and Investigation of Bacterial Adhesion on Biomaterials Using a Non-Constant-Depth Film Fermenter

    Science.gov (United States)

    Lüdecke, Claudia; Jandt, Klaus D.; Siegismund, Daniel; Kujau, Marian J.; Zang, Emerson; Rettenmayr, Markus; Bossert, Jörg; Roth, Martin

    2014-01-01

    Biomaterials-associated infections are primarily initiated by the adhesion of microorganisms on the biomaterial surfaces and subsequent biofilm formation. Understanding the fundamental microbial adhesion mechanisms and biofilm development is crucial for developing strategies to prevent such infections. Suitable in vitro systems for biofilm cultivation and bacterial adhesion at controllable, constant and reproducible conditions are indispensable. This study aimed (i) to modify the previously described constant-depth film fermenter for the reproducible cultivation of biofilms at non-depth-restricted, constant and low shear conditions and (ii) to use this system to elucidate bacterial adhesion kinetics on different biomaterials, focusing on biomaterials surface nanoroughness and hydrophobicity. Chemostat-grown Escherichia coli were used for biofilm cultivation on titanium oxide and investigating bacterial adhesion over time on titanium oxide, poly(styrene), poly(tetrafluoroethylene) and glass. Using chemostat-grown microbial cells (single-species continuous culture) minimized variations between the biofilms cultivated during different experimental runs. Bacterial adhesion on biomaterials comprised an initial lag-phase I followed by a fast adhesion phase II and a phase of saturation III. With increasing biomaterials surface nanoroughness and increasing hydrophobicity, adhesion rates increased during phases I and II. The influence of materials surface hydrophobicity seemed to exceed that of nanoroughness during the lag-phase I, whereas it was vice versa during adhesion phase II. This study introduces the non-constant-depth film fermenter in combination with a chemostat culture to allow for a controlled approach to reproducibly cultivate biofilms and to investigate bacterial adhesion kinetics at constant and low shear conditions. The findings will support developing and adequate testing of biomaterials surface modifications eventually preventing biomaterial

  19. Pseudomonas Lipopeptide Biosurfactants

    DEFF Research Database (Denmark)

    Bonnichsen, Lise

    Pseudomonas lipopetide biosurfactants are amphiphilic molecules with a broad range of natural functions. Due to their surface active properties, it has been suggested that Pseudomonas lipopetides potentially play a role in biodegradation of hydrophobic compounds and have essential functions...... in biofilm formation, however, detailed studies of these roles have not yet been carried out. The overall aim of this PhD project was therefore to elucidate in more depth the roles played by Pseudomonas lipopetides in pollutant biodegradation and biofilm formation. This study investigated the effect...... of the Pseudomonas lipopeptides belonging to different structural groups on important biodegradation parameters, mainly; solubilization and emulsification of hydrophobic pollutants (alkanes and PAHs) and increase of cell surface hydrophobicity of bacterial degraders. Ultimately, it was tested if these parameters led...

  20. Characterization of bacterial diversity in pulque, a traditional Mexican alcoholic fermented beverage, as determined by 16S rDNA analysis.

    Science.gov (United States)

    Escalante, Adelfo; Rodríguez, María Elena; Martínez, Alfredo; López-Munguía, Agustín; Bolívar, Francisco; Gosset, Guillermo

    2004-06-15

    The bacterial diversity in pulque, a traditional Mexican alcoholic fermented beverage, was studied in 16S rDNA clone libraries from three pulque samples. Sequenced clones identified as Lactobacillus acidophilus, Lactobacillus strain ASF360, L. kefir, L. acetotolerans, L. hilgardii, L. plantarum, Leuconostoc pseudomesenteroides, Microbacterium arborescens, Flavobacterium johnsoniae, Acetobacter pomorium, Gluconobacter oxydans, and Hafnia alvei, were detected for the first time in pulque. Identity of 16S rDNA sequenced clones showed that bacterial diversity present among pulque samples is dominated by Lactobacillus species (80.97%). Seventy-eight clones exhibited less than 95% of relatedness to NCBI database sequences, which may indicate the presence of new species in pulque samples.

  1. [Meningoencephalitis caused by Pseudomonas cepacia].

    Science.gov (United States)

    Pérez Monrás, Miriam Fina; Batlle Almodóvar, María del Carmen; González, Cernero; Tamargo Martínez, Isis; Meneses, Félix Dickinson

    2006-01-01

    A case of meningoencephalitis of bacterial etiology caused by Pseudomonas cepacia was described. The strain was received at the Reference Laboratory of Bacterial Acute Respiratory Infections of "Pedro Kouri" Institute of Tropical Medicine, where its microbiological identification was confirmed. This isolation was a finding in an adult immunocompetent patient. The evolution was favourable with no sequelae for his future life. Pseudomona cepacia has been associated with respiratory infections in patients with cystic fibrosis. Patients with Pseudomonas cepacia may be asymptomatic or present fatal acute and fulminant infection.

  2. Dietary pectin-derived acidic oligosaccharides improve the pulmonary bacterial clearance of Pseudomonas aeruginosa lung infection in mice by modulating intestinal microbiota and immunity.

    Science.gov (United States)

    Bernard, Henry; Desseyn, Jean-Luc; Bartke, Nana; Kleinjans, Lennart; Stahl, Bernd; Belzer, Clara; Knol, Jan; Gottrand, Frédéric; Husson, Marie-Odile

    2015-01-01

    A predominantly T-helper type 2 (Th2) immune response is critical in the prognosis of pulmonary Pseudomonas aeruginosa infection. But the mucosal and systemic immune responses can be influenced by the intestinal microbiota. We assessed the effect of microbiota compositional changes induced by a diet enriched in 5% acidic oligosaccharides derived from pectin (pAOS) on the immune response and outcome of chronic pulmonary P. aeruginosa infection in mice. pAOS promoted Th1 polarization by increasing interferon γ release, upregulating t-bet gene expression, decreasing interleukin 4 secretion, and downregulating gata3 gene expression. pAOS also sustained the release of keratinocyte chemoattractant, recruited polynuclear leukocytes and macrophages, stimulated M1 macrophage activation and interleukin 10 release, and decreased tumor necrosis factor α release in the lung. These effects led to increased bacterial clearance after the first and second P. aeruginosa infections. pAOS modified the intestinal microbiota by stimulating the growth of species involved in immunity development, such as Bifidobacterium species, Sutturella wadsworthia, and Clostridium cluster XIVa organisms, and at the same time increased the production of butyrate and propionate. These results suggest that pAOS may have beneficial effects by limiting the number and severity of pulmonary exacerbations in patients chronically infected with P. aeruginosa, such as individuals with cystic fibrosis. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  3. Gaseous 3-pentanol primes plant immunity against a bacterial speck pathogen, Pseudomonas syringae pv. tomato via salicylic acid and jasmonic acid-dependent signaling pathways in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Geun Cheol eSong

    2015-10-01

    Full Text Available 3-Pentanol is an active organic compound produced by plants and is a component of emitted insect sex pheromones. A previous study reported that drench application of 3-pentanol elicited plant immunity against microbial pathogens and an insect pest in crop plants. Here, we evaluated whether 3-pentanol and the derivatives 1-pentanol and 2-pentanol induced plant systemic resistance using the in vitro I-plate system. Exposure of Arabidopsis seedlings to 10 M and 100 nM 3-pentanol evaporate elicited an immune response to Pseudomonas syringae pv. tomato DC3000. We performed quantitative real-time PCR to investigate the 3-pentanol-mediated Arabidopsis immune responses by determining Pathogenesis-Related (PR gene expression levels associated with defense signaling through SA, JA, and ethylene signaling pathways. The results show that exposure to 3-pentanol and subsequent pathogen challenge upregulated PDF1.2 and PR1 expression. Selected Arabidopsis mutants confirmed that the 3-pentanol-mediated immune response involved salicylic acid (SA and jasmonic acid (JA signaling pathways and the NPR1 gene. Taken together, this study indicates that gaseous 3-pentanol triggers induced resistance in Arabidopsis by priming SA and JA signaling pathways. To our knowledge, this is the first report that a volatile compound of an insect sex pheromone triggers plant systemic resistance against a bacterial pathogen.

  4. A novel Pseudomonas aeruginosa bacteriophage, Ab31, a chimera formed from temperate phage PAJU2 and P. putida lytic phage AF: characteristics and mechanism of bacterial resistance.

    Directory of Open Access Journals (Sweden)

    Libera Latino

    Full Text Available A novel temperate bacteriophage of Pseudomonas aeruginosa, phage vB_PaeP_Tr60_Ab31 (alias Ab31 is described. Its genome is composed of structural genes related to those of lytic P. putida phage AF, and regulatory genes similar to those of temperate phage PAJU2. The virion structure resembles that of phage AF and other lytic Podoviridae (S. enterica Epsilon 15 and E. coli phiv10 with similar tail spikes. Ab31 was able to infect P. aeruginosa strain PA14 and two genetically related strains called Tr60 and Tr162, out of 35 diverse strains from cystic fibrosis patients. Analysis of resistant host variants revealed different phenotypes, including induction of pigment and alginate overproduction. Whole genome sequencing of resistant variants highlighted the existence of a large deletion of 234 kbp in two strains, encompassing a cluster of genes required for the production of CupA fimbriae. Stable lysogens formed by Ab31 in strain Tr60, permitted the identification of the insertion site. During colonization of the lung in cystic fibrosis patients, P. aeruginosa adapts by modifying its genome. We suggest that bacteriophages such as Ab31 may play an important role in this adaptation by selecting for bacterial characteristics that favor persistence of bacteria in the lung.

  5. Differential effect of early antibiotic intervention on bacterial fermentation patterns and mucosal gene expression in the colon of pigs under diets with different protein levels.

    Science.gov (United States)

    Zhang, Chuanjian; Yu, Miao; Yang, Yuxiang; Mu, Chunlong; Su, Yong; Zhu, Weiyun

    2017-03-01

    The study aimed to evaluate the effects of early antibiotic intervention (EAI) on bacterial fermentation patterns and mucosal immune markers in the colon of pigs with different protein level diets. Eighteen litters of piglets at day (d) 7 were fed creep feed without or with growth promoting antibiotics until d 42. At d 42, pigs within each group were further randomly assigned to a normal- or low-crude protein (CP) diet. At d 77 and d 120, five pigs per group were slaughtered for analyzing colonic bacteria, metabolites, and mucosal gene expressions. Results showed that low-CP diet increased propionate and butyrate concentrations at d 77 but reduced ammonia and phenol concentrations (P bacteria groups (Firmicutes, Clostridium cluster IV, Clostridium cluster XIVa, Escherichia coli, and Lactobacillus), but EAI showed limited effects. Low-CP diet down-regulated gene expressions of pro-inflammatory cytokines, toll-like receptor (TLR4), myeloid differentiating factor 88 (MyD88), and nuclear factor-κB p65 (NF-κB p65) (P fermentation and gene expressions of pro-inflammatory cytokines. Low-CP diet markedly reduced protein fermentation, modified microbial communities, and down-regulated gene expressions of pro-inflammatory cytokines possibly via down-regulating TLR4-MyD88-NF-κB signaling pathway.

  6. RND type efflux pump system MexAB-OprM of pseudomonas aeruginosa selects bacterial languages, 3-oxo-acyl-homoserine lactones, for cell-to-cell communication

    Directory of Open Access Journals (Sweden)

    Minagawa Shu

    2012-05-01

    Full Text Available Abstract Background Bacteria release a wide variety of small molecules including cell-to-cell signaling compounds. Gram-negative bacteria use a variety of self-produced autoinducers such as acylated homoserine lactones (acyl-HSLs as signal compounds for quorum sensing (QS within and between bacterial species. QS plays a significant role in the pathogenesis of infectious diseases and in beneficial symbiosis by responding to acyl-HSLs in Pseudomonas aeruginosa. It is considered that the selection of bacterial languages is necessary to regulate gene expression and thus it leads to the regulation of virulence and provides a growth advantage in several environments. In this study, we hypothesized that RND-type efflux pump system MexAB-OprM of P. aeruginosa might function in the selection of acyl-HSLs, and we provide evidence to support this hypothesis. Results Loss of MexAB-OprM due to deletion of mexB caused increases in QS responses, as shown by the expression of gfp located downstream of the lasB promoter and LasB elastase activity, which is regulated by a LasR-3-oxo-C12-HSL complex. Either complementation with a plasmid containing wild-type mexB or the addition of a LasR-specific inhibitor, patulin, repressed these high responses to 3-oxo-acyl-HSLs. Furthermore, it was shown that the acyl-HSLs-dependent response of P. aeruginosa was affected by the inhibition of MexB transport activity and the mexB mutant. The P. aeruginosa MexAB-OprM deletion mutant showed a strong QS response to 3-oxo-C10-HSL produced by Vibrio anguillarum in a bacterial cross-talk experiment. Conclusion This work demonstrated that MexAB-OprM does not control the binding of LasR to 3-oxo-Cn-HSLs but rather accessibility of non-cognate acyl-HSLs to LasR in P. aeruginosa. MexAB-OprM not only influences multidrug resistance, but also selects acyl-HSLs and regulates QS in P. aeruginosa. The results demonstrate a new QS regulation mechanism via the efflux system MexAB-OprM in P

  7. Identification of the bacterial community responsible for traditional fermentation during sour cassava starch, cachaça and minas cheese production using culture-independent 16s rRNA gene sequence analysis

    Directory of Open Access Journals (Sweden)

    Inayara C. A. Lacerda

    2011-06-01

    Full Text Available We used a cultivation-independent, clone library-based 16S rRNA gene sequence analysis to identify bacterial communities present during traditional fermentation in sour cassava starch, cachaça and cheese production in Brazil. Partial 16S rRNA gene clone sequences from sour cassava starch samples collected on day five of the fermentation process indicated that Leuconostoc citreum was the most prevalent species, representing 47.6% of the clones. After 27 days of fermentation, clones (GenBank accession numbers GQ999786 and GQ999788 related to unculturable bacteria were the most prevalent, representing 43.8% of the clones from the bacterial community analyzed. The clone represented by the sequence GQ999786 was the most prevalent at the end of the fermentation period. The majority of clones obtained from cachaça samples during the fermentation of sugar cane juice were from the genus Lactobacillus. Lactobacillus nagelli was the most prevalent at the beginning of the fermentation process, representing 76.9% of the clones analyzed. After 21 days, Lactobacillus harbinensis was the most prevalent species, representing 75% of the total clones. At the end of the fermentation period, Lactobacillus buchneri was the most prevalent species, representing 57.9% of the total clones. In the Minas cheese samples, Lactococcus lactis was the most prevalent species after seven days of ripening. After 60 days of ripening, Streptococcus salivarius was the most prevalent species. Our data show that these three fermentation processes are conducted by a succession of bacterial species, of which lactic acid bacteria are the most prevalent.

  8. Identification of the bacterial community responsible for traditional fermentation during sour cassava starch, cachaça and minas cheese production using culture-independent 16s rRNA gene sequence analysis.

    Science.gov (United States)

    Lacerda, Inayara C A; Gomes, Fátima C O; Borelli, Beatriz M; Faria, César L L; Franco, Gloria R; Mourão, Marina M; Morais, Paula B; Rosa, Carlos A

    2011-04-01

    We used a cultivation-independent, clone library-based 16S rRNA gene sequence analysis to identify bacterial communities present during traditional fermentation in sour cassava starch, cachaça and cheese production in Brazil. Partial 16S rRNA gene clone sequences from sour cassava starch samples collected on day five of the fermentation process indicated that Leuconostoc citreum was the most prevalent species, representing 47.6% of the clones. After 27 days of fermentation, clones (GenBank accession numbers GQ999786 and GQ999788) related to unculturable bacteria were the most prevalent, representing 43.8% of the clones from the bacterial community analyzed. The clone represented by the sequence GQ999786 was the most prevalent at the end of the fermentation period. The majority of clones obtained from cachaça samples during the fermentation of sugar cane juice were from the genus Lactobacillus. Lactobacillus nagelli was the most prevalent at the beginning of the fermentation process, representing 76.9% of the clones analyzed. After 21 days, Lactobacillus harbinensis was the most prevalent species, representing 75% of the total clones. At the end of the fermentation period, Lactobacillus buchneri was the most prevalent species, representing 57.9% of the total clones. In the Minas cheese samples, Lactococcus lactis was the most prevalent species after seven days of ripening. After 60 days of ripening, Streptococcus salivarius was the most prevalent species. Our data show that these three fermentation processes are conducted by a succession of bacterial species, of which lactic acid bacteria are the most prevalent.

  9. Analysis of the Bacterial Communities in Two Liquors of Soy Sauce Aroma as Revealed by High-Throughput Sequencing of the 16S rRNA V4 Hypervariable Region

    Science.gov (United States)

    Tang, Jing; Tang, Xiaoxin; Tang, Ming; Zhang, Ximin; Xu, Xiaorong

    2017-01-01

    Chinese liquor is one of the world's oldest distilled alcoholic beverages and an important commercial fermented product in China. The Chinese liquor fermentation process has three stages: making Daqu (the starter), stacking fermentation on the ground, and liquor fermentation in pits. We investigated the bacterial diversity of Maotai and Guotai Daqu and liquor fermentation using high-throughput sequencing of the V4 hypervariable region of the 16S rRNA gene. A total of 70,297 sequences were obtained from the Daqu samples and clustered into 17 phyla. The composition of the bacterial communities in the Daqu from these two soy sauce aroma-style Chinese liquors was the same, although some bacterial species changed in abundance. Between the Daqu and liquor fermentation samples, 12 bacterial phyla increased. The abundance of Lactobacillus and Pseudomonas increased in the liquor fermentation. This study has used high-throughput sequencing to provide new insights into the bacterial composition of the Chinese liquor Daqu and fermentation. Similarities in the distribution of bacteria in the soy sauce aroma-style Chinese liquors Daqu suggest that the abundance of bacteria might be generally concerned to other liquor. PMID:28337455

  10. Analysis of the Bacterial Communities in Two Liquors of Soy Sauce Aroma as Revealed by High-Throughput Sequencing of the 16S rRNA V4 Hypervariable Region.

    Science.gov (United States)

    Tang, Jing; Tang, Xiaoxin; Tang, Ming; Zhang, Ximin; Xu, Xiaorong; Yi, Yin

    2017-01-01

    Chinese liquor is one of the world's oldest distilled alcoholic beverages and an important commercial fermented product in China. The Chinese liquor fermentation process has three stages: making Daqu (the starter), stacking fermentation on the ground, and liquor fermentation in pits. We investigated the bacterial diversity of Maotai and Guotai Daqu and liquor fermentation using high-throughput sequencing of the V4 hypervariable region of the 16S rRNA gene. A total of 70,297 sequences were obtained from the Daqu samples and clustered into 17 phyla. The composition of the bacterial communities in the Daqu from these two soy sauce aroma-style Chinese liquors was the same, although some bacterial species changed in abundance. Between the Daqu and liquor fermentation samples, 12 bacterial phyla increased. The abundance of Lactobacillus and Pseudomonas increased in the liquor fermentation. This study has used high-throughput sequencing to provide new insights into the bacterial composition of the Chinese liquor Daqu and fermentation. Similarities in the distribution of bacteria in the soy sauce aroma-style Chinese liquors Daqu suggest that the abundance of bacteria might be generally concerned to other liquor.

  11. Analysis of the Bacterial Communities in Two Liquors of Soy Sauce Aroma as Revealed by High-Throughput Sequencing of the 16S rRNA V4 Hypervariable Region

    Directory of Open Access Journals (Sweden)

    Jing Tang

    2017-01-01

    Full Text Available Chinese liquor is one of the world’s oldest distilled alcoholic beverages and an important commercial fermented product in China. The Chinese liquor fermentation process has three stages: making Daqu (the starter, stacking fermentation on the ground, and liquor fermentation in pits. We investigated the bacterial diversity of Maotai and Guotai Daqu and liquor fermentation using high-throughput sequencing of the V4 hypervariable region of the 16S rRNA gene. A total of 70,297 sequences were obtained from the Daqu samples and clustered into 17 phyla. The composition of the bacterial communities in the Daqu from these two soy sauce aroma-style Chinese liquors was the same, although some bacterial species changed in abundance. Between the Daqu and liquor fermentation samples, 12 bacterial phyla increased. The abundance of Lactobacillus and Pseudomonas increased in the liquor fermentation. This study has used high-throughput sequencing to provide new insights into the bacterial composition of the Chinese liquor Daqu and fermentation. Similarities in the distribution of bacteria in the soy sauce aroma-style Chinese liquors Daqu suggest that the abundance of bacteria might be generally concerned to other liquor.

  12. Simultaneous Saccharification and Fermentation of Sugar Beet Pulp with Mixed Bacterial Cultures for Lactic Acid and Propylene Glycol Production

    Directory of Open Access Journals (Sweden)

    Joanna Berlowska

    2016-10-01

    Full Text Available Research into fermentative production of lactic acid from agricultural by-products has recently concentrated on the direct conversion of biomass, whereby pure sugars are replaced with inexpensive feedstock in the process of lactic acid production. In our studies, for the first time, the source of carbon used is sugar beet pulp, generated as a by-product of industrial sugar production. In this paper, we focus on the simultaneous saccharification of lignocellulosic biomass and fermentation of lactic acid, using mixed cultures with complementary assimilation profiles. Lactic acid is one of the primary platform chemicals, and can be used to synthesize a wide variety of useful products, including green propylene glycol. A series of controlled batch fermentations was conducted under various conditions, including pretreatment with enzymatic hydrolysis. Inoculation was performed in two sequential stages, to avoid carbon catabolite repression. Biologically-synthesized lactic acid was catalytically reduced to propylene glycol over 5% Ru/C. The highest lactic acid yield was obtained with mixed cultures. The yield of propylene glycol from the biological lactic acid was similar to that obtained with a water solution of pure lactic acid. Our results show that simultaneous saccharification and fermentation enables generation of lactic acid, suitable for further chemical transformations, from agricultural residues.

  13. Simultaneous Saccharification and Fermentation of Sugar Beet Pulp with Mixed Bacterial Cultures for Lactic Acid and Propylene Glycol Production.

    Science.gov (United States)

    Berlowska, Joanna; Cieciura, Weronika; Borowski, Sebastian; Dudkiewicz, Marta; Binczarski, Michal; Witonska, Izabela; Otlewska, Anna; Kregiel, Dorota

    2016-10-17

    Research into fermentative production of lactic acid from agricultural by-products has recently concentrated on the direct conversion of biomass, whereby pure sugars are replaced with inexpensive feedstock in the process of lactic acid production. In our studies, for the first time, the source of carbon used is sugar beet pulp, generated as a by-product of industrial sugar production. In this paper, we focus on the simultaneous saccharification of lignocellulosic biomass and fermentation of lactic acid, using mixed cultures with complementary assimilation profiles. Lactic acid is one of the primary platform chemicals, and can be used to synthesize a wide variety of useful products, including green propylene glycol. A series of controlled batch fermentations was conducted under various conditions, including pretreatment with enzymatic hydrolysis. Inoculation was performed in two sequential stages, to avoid carbon catabolite repression. Biologically-synthesized lactic acid was catalytically reduced to propylene glycol over 5% Ru/C. The highest lactic acid yield was obtained with mixed cultures. The yield of propylene glycol from the biological lactic acid was similar to that obtained with a water solution of pure lactic acid. Our results show that simultaneous saccharification and fermentation enables generation of lactic acid, suitable for further chemical transformations, from agricultural residues.

  14. Inactivation of bacterial pathogens in yoba mutandabota, a dairy product fermented with the probiotic Lactobacillus rhamnosus yoba

    NARCIS (Netherlands)

    Mpofu, A.; Linnemann, A.R.; Nout, M.J.R.; Zwietering, M.H.; Smid, E.J.; Besten, den H.M.W.

    2016-01-01

    Mutandabota is a dairy product consumed as a major source of proteins and micronutrients in Southern Africa. In this study the microbial safety of traditional and a variant of mutandabota fermented with the probiotic Lactobacillus rhamnosus yoba (yoba mutandabota) was investigated by challenging the

  15. Pseudomonas saudiphocaensis’ sp. nov., a new bacterial species isolated from currency notes collected during the Hajj pilgrimage in 2012 at Makkah, Saudi Arabia

    Directory of Open Access Journals (Sweden)

    E.I. Azhar

    2017-01-01

    Full Text Available We report here the main characteristics of ‘Pseudomonas saudiphocaensis’ strain 20_BNT (CSUR P1224, a new species of the Pseudomonas genus that was isolated from currency notes collected during the Hajj pilgrimage in 2012 at Makkah, Saudi Arabia.

  16. Application of Endophytic Pseudomonas fluorescens and a Bacterial Consortium to Brassica napus Can Increase Plant Height and Biomass under Greenhouse and Field Conditions

    Directory of Open Access Journals (Sweden)

    Richard D. Lally

    2017-12-01

    Full Text Available Plant associated bacteria with plant growth promotion (PGP properties have been proposed for use as environmentally friendly biofertilizers for sustainable agriculture; however, analysis of their efficacy in the field is often limited. In this study, greenhouse and field trials were carried out using individual endophytic Pseudomonas fluorescens strains, the well characterized rhizospheric P. fluorescens F113 and an endophytic microbial consortium of 10 different strains. These bacteria had been previously characterized with respect to their PGP properties in vitro and had been shown to harbor a range of traits associated with PGP including siderophore production, 1-aminocyclopropane-1-carboxylic acid (ACC deaminase activity, and inorganic phosphate solubilization. In greenhouse experiments individual strains tagged with gfp and Kmr were applied to Brassica napus as a seed coat and were shown to effectively colonize the rhizosphere and root of B. napus and in addition they demonstrated a significant increase in plant biomass compared with the non-inoculated control. In the field experiment, the bacteria (individual and consortium were spray inoculated to winter oilseed rape B. napus var. Compass which was grown under standard North Western European agronomic conditions. Analysis of the data provides evidence that the application of the live bacterial biofertilizers can enhance aspects of crop development in B. napus at field scale. The field data demonstrated statistically significant increases in crop height, stem/leaf, and pod biomass, particularly, in the case of the consortium inoculated treatment. However, although seed and oil yield were increased in the field in response to inoculation, these data were not statistically significant under the experimental conditions tested. Future field trials will investigate the effectiveness of the inoculants under different agronomic conditions.

  17. Application of EndophyticPseudomonas fluorescensand a Bacterial Consortium toBrassica napusCan Increase Plant Height and Biomass under Greenhouse and Field Conditions.

    Science.gov (United States)

    Lally, Richard D; Galbally, Paul; Moreira, António S; Spink, John; Ryan, David; Germaine, Kieran J; Dowling, David N

    2017-01-01

    Plant associated bacteria with plant growth promotion (PGP) properties have been proposed for use as environmentally friendly biofertilizers for sustainable agriculture; however, analysis of their efficacy in the field is often limited. In this study, greenhouse and field trials were carried out using individual endophytic Pseudomonas fluorescens strains, the well characterized rhizospheric P. fluorescens F113 and an endophytic microbial consortium of 10 different strains. These bacteria had been previously characterized with respect to their PGP properties in vitro and had been shown to harbor a range of traits associated with PGP including siderophore production, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, and inorganic phosphate solubilization. In greenhouse experiments individual strains tagged with gfp and Km r were applied to Brassica napus as a seed coat and were shown to effectively colonize the rhizosphere and root of B. napus and in addition they demonstrated a significant increase in plant biomass compared with the non-inoculated control. In the field experiment, the bacteria (individual and consortium) were spray inoculated to winter oilseed rape B. napus var. Compass which was grown under standard North Western European agronomic conditions. Analysis of the data provides evidence that the application of the live bacterial biofertilizers can enhance aspects of crop development in B. napus at field scale. The field data demonstrated statistically significant increases in crop height, stem/leaf, and pod biomass, particularly, in the case of the consortium inoculated treatment. However, although seed and oil yield were increased in the field in response to inoculation, these data were not statistically significant under the experimental conditions tested. Future field trials will investigate the effectiveness of the inoculants under different agronomic conditions.

  18. Fermented milk for hypertension

    DEFF Research Database (Denmark)

    Usinger, Lotte; Reimer, Christina; Ibsen, Hans

    2012-01-01

    Fermented milk has been suggested to have a blood pressure lowering effect through increased content of proteins and peptides produced during the bacterial fermentation. Hypertension is one of the major risk factors for cardiovascular disease world wide and new blood pressure reducing lifestyle...

  19. The effect of organic acid mixture and bacterial inoculant on fermentation in laboratory silos of climper high moisture maize grain corn

    Directory of Open Access Journals (Sweden)

    Václav Pyrochta

    2005-01-01

    Full Text Available In the experiment, the effect of chemical (A and biological (B additiva on the fermentation quality of climper high moisture maize grain corn was examined, compared with the untreated control (K. The chemical means contained propionic, formic and benzoic acids and ammonium formate as effective substances. As effective substances of bacterial water–soluble inoculants, selected were bacterial strains of Propionibacterium shermanii JS and Lactobacillus casei LC-705. Both conservative preservatives were added equally to the ensilaged material. The addition of chemical additivum under conditions of our experiment increased statistically significantly (P<0.01 the contents of acetic acid (7.66±0.95 g/kg DM, ethanol (11.22±0.65 g/kg DM and pH values (4.33±0.02 in experimental silages. Simultaneously, a statistically significant (P<0.01 inhibition of lactic acid formation (15.17±2.75 g/kg DM and of total content of all fermentation acids (22.33±2.38 g/kg DM occurred. The bacterial inoculant increased significantly (P<0.05 the content of lactic acid (26.78±2.63 g/kg DM and the total acid content (32.87±2.88 g/kg DM in inoculated silages. The inoculation positive effect was demonstrated highly significantly (P<0.01 in reduction of ethanol amount (2.14±0.40 g/kg DM and of totat acidification. The pH value (4.21±0.02 was significantly lower (P<0.05 than that in the control silage (4.24±0.02. The fermentation characteristics in the inoculated silages by us were more favourable. The addition of organic acid mixture in the used concentration of 3.5 L/t did not confirm the positive effect on climper maize grain corn quality as expected.

  20. Non-susceptibility trends among Pseudomonas aeruginosa and other non-fermentative Gram-negative bacteria from bacteraemias in the UK and Ireland, 2001-06.

    Science.gov (United States)

    Livermore, David M; Hope, Russell; Brick, Geraldine; Lillie, Mark; Reynolds, Rosy

    2008-11-01

    Pseudomonas and Acinetobacter spp. are important opportunists, notorious for resistance. Pseudomonas spp. are collected in the British Society for Antimicrobial Chemotherapy (BSAC) bacteraemia surveillance, with Acinetobacter spp. and Stenotrophomonas maltophilia well represented in the 'other Gram-negatives' group. Data for collected isolates were reviewed together with LabBase bacteraemia reports to the Health Protection Agency (HPA). Isolates with unusual resistances were subjected to molecular investigation. From 2001 to 2006, the BSAC surveillance collected 1226 Pseudomonas aeruginosa, 240 Acinetobacter spp.-125 of them Acinetobacter calcoaceticus/baumannii (Acb) complex-and 165 S. maltophilia. Among P. aeruginosa, non-susceptibility rates to beta-lactams and gentamicin fluctuated, without trend, below 10%; those to ciprofloxacin ranged from 16% to 22%. One P. aeruginosa isolate from 2001 had VIM-2 metallo-beta-lactamase. For Acb, the BSAC data indicated frequent non-susceptibility, except to imipenem, where only five non-susceptible isolates were collected, all after 2003, four of them belonging to the OXA-23 clone 1 lineage which is prevalent in Southeast England. Reports to the HPA indicated rising imipenem non-susceptibility in Acb (P /=16 mg/L for Acb OXA-23 clone 1. Ceftobiprole had higher MICs than ceftazidime for P. aeruginosa, but 81% of the isolates were inhibited at

  1. Culture-independent study of the diversity of microbial populations in brines during fermentation of naturally-fermented Aloreña green table olives.

    Science.gov (United States)

    Abriouel, Hikmate; Benomar, Nabil; Lucas, Rosario; Gálvez, Antonio

    2011-01-05

    Aloreña table olives are naturally fermented traditional green olives with a denomination of protection (DOP). The present study focused on Aloreña table olives manufactured by small and medium enterprises (SMEs) from Valle del Guadalhorce (Southern Spain) under three different conditions (cold storage, and ambient temperature fermentations in small vats and in large fermentation tanks). The microbial load of brines during fermentation was studied by plate counting, and the microbial diversity was determined by a culture-independent approach based on PCR-DGGE analysis. The viable microbial populations (total mesophilic counts, yeasts and molds, and lactic acid bacteria - LAB) changed in cell numbers during the course of fermentation. Great differences were also observed between cold, vat and tank fermentations and also from one SME to another. Yeasts seemed to be the predominant populations in cold-fermented olives, while LAB counts increased towards the end of vat and tank fermentations at ambient temperature. According to PCR-DGGE analysis, microbial populations in cold-fermented olives were composed mostly by Gordonia sp./Pseudomonas sp. and Sphingomonas sp./Sphingobium sp./Sphingopyxis sp. together with halophilic archaea (mainly by haloarchaeon/Halosarcina pallida and uncultured archaeon/uncultured haloarchaeon/Halorubrum orientalis) and yeasts (Saccharomyces cerevisiae and Candida cf. apicola). Vat-fermented olives stored at ambient temperature included a more diverse bacterial population: Gordonia sp./Pseudomonas sp., Sphingomonas sp./Sphingobium sp./Sphingopyxis sp. and Thalassomonas agarivorans together with halophilic archaea and yeasts (mainly S. cerevisiae and C. cf. apicola, but also Pichia sp., and Pichia manshurica/Pichia galeiformis). Some LAB were detected towards the end of vat fermentations, including Lactobacillus pentosus/Lactobacillus plantarum and Lactobacillus vaccinostercus/Lactobacillus suebicus. Only the tank fermentation showed a clear

  2. The Dynamic Microbiota Profile During Pepper (Piper nigrum L.) Peeling by Solid-State Fermentation.

    Science.gov (United States)

    Hu, Qisong; Zhang, Jiachao; Xu, Chuanbiao; Li, Congfa; Liu, Sixin

    2017-06-01

    White pepper (Piper nigrum L.), a well-known spice, is the main pepper processing product in Hainan province, China. The solid-state method of fermentation can peel pepper in a highly efficient manner and yield high-quality white pepper. In the present study, we used next-generation sequencing to reveal the dynamic changes in the microbiota during pepper peeling by solid-state fermentation. The results suggested that the inoculated Aspergillus niger was dominant throughout the fermentation stage, with its strains constituting more than 95% of the fungi present; thus, the fungal community structure was relatively stable. The bacterial community structure fluctuated across different fermentation periods; among the bacteria present, Pseudomonas, Tatumella, Pantoea, Acinetobacter, Lactococcus, and Enterobacter accounted for more than 95% of all bacteria. Based on the correlations among the microbial community, we found that Pseudomonas and Acinetobacter were significantly positively related with A. niger, which showed strong synergy with them. In view of the microbial functional gene analysis, we found that these three bacteria and fungi were closely related to the production of pectin esterase (COG4677) and acetyl xylan esterase (COG3458), the key enzymes for pepper peeling. The present research clarifies the solid-state fermentation method of pepper peeling and lays a theoretical foundation to promote the development of the pepper peeling process and the production of high-quality white pepper.

  3. Characteristics and Efficiency of Glutamine Production by Coupling of a Bacterial Glutamine Synthetase Reaction with the Alcoholic Fermentation System of Baker’s Yeast

    Science.gov (United States)

    Wakisaka, Shinji; Ohshima, Yoshifumi; Ogawa, Masahiro; Tochikura, Tatsurokuro; Tachiki, Takashi

    1998-01-01

    Glutamine production with bacterial glutamine synthetase (GS) and the sugar-fermenting system of baker’s yeast for ATP regeneration was investigated by determining the product yield obtained with the energy source for ATP regeneration (i.e., glucose) for yeast fermentation. Fructose 1,6-bisphosphate was accumulated temporarily prior to the formation of glutamine in mixtures which consisted of dried yeast cells, GS, their substrate (glucose and glutamate and ammonia), inorganic phosphate, and cofactors. By an increase in the amounts of GS and inorganic phosphate, the amounts of glutamine formed increased to 19 to 54 g/liter, with a yield increase of 69 to 72% based on the energy source (glucose) for ATP regeneration. The analyses of sugar fermentation of the yeast in the glutamine-producing mixtures suggested that the apparent hydrolysis of ATP by a futile cycle(s) at the early stage of glycolysis in the yeast cells reduces the efficiency of ATP utilization. Inorganic phosphate inhibits phosphatase(s) and thus improves glutamine yield. However, the analyses of GS activity in the glutamine-producing mixtures suggested that the higher concentration of inorganic phosphate as well as the limited amount of ATP-ADP caused the low reactivity of GS in the glutamine-producing mixtures. A result suggestive of improved glutamine yield under the conditions with lower concentrations of inorganic phosphate was obtained by using a yeast mutant strain that had low assimilating ability for glycerol and ethanol. In the mutant, the activity of the enzymes involved in gluconeogenesis, especially fructose 1,6-bisphosphatase, was lower than that in the wild-type strain. PMID:9687456

  4. Bacterial Ecology of Fermented Cucumber Rising pH Spoilage as Determined by Non-Culture Based Methods

    Science.gov (United States)

    Medina, Eduardo; Pérez-Díaz, Ilenys M.; Breidt, Fred; Hayes, Janet; Franco, Wendy; Butz, Natasha; Azcarate-Peril, María Andrea

    2016-01-01

    Fermented cucumber spoilage (FCS) characterized by rising pH and the appearance of manure and cheese like aromas is a challenge of significant economical impact for the pickling industry. Previous culture based studies identified the yeasts Pichia manshurica and Issatchenkia occidentalis, four gram positive bacteria, Lactobacillus buchneri, Lactobacillus parrafaraginis, Clostridium sp. and Propionibacterium and one gram-negative genus, Pectinatus as relevant in various stages of FCS given their ability to metabolize lactic acid. It was the objective of this study to augment the current knowledge of FCS using culture independent methods to microbiologically characterize commercial spoilage samples. Ion Torrent data and 16S rRNA cloning library analyses of samples collected from commercial fermentation tanks confirmed the presence of L. rapi and L. buchneri and revealed the presence of additional species involved in the development of FCS such as Lactobacillus namurensis, Lactobacillus acetotolerans, Lactobacillus panis, Acetobacter peroxydans, Acetobacter aceti, and Acetobacter pasteurianus at pH below 3.4. The culture independent analyses also revealed the presence of species of Veillonella and Dialister in spoilage samples with pH above 4.0 and confirmed the presence of Pectinatus spp. during lactic acid degradation at the higher pH. Acetobacter spp. were successfully isolated from commercial samples collected from tanks subjected to air purging by plating on Mannitol Yeast Peptone agar. In contrast, Lactobacillus spp. were primarily identified in samples of FCS collected from tanks not subjected to air purging for more than 4 months. Thus, it is speculated that oxygen availability may be a determining factor in the initiation of spoilage and the leading microbiota. Practical Application Understanding of the underlying microbiology and biochemistry driving FCS is essential to enhancing the sodium chloride (NaCl)-free cucumber fermentation technology and in

  5. Stable Carbon Isotope Fractionation during Bacterial Acetylene Fermentation: Potential for Life Detection in Hydrocarbon-Rich Volatiles of Icy Planet(oid)s.

    Science.gov (United States)

    Miller, Laurence G; Baesman, Shaun M; Oremland, Ronald S

    2015-11-01

    We report the first study of stable carbon isotope fractionation during microbial fermentation of acetylene (C2H2) in sediments, sediment enrichments, and bacterial cultures. Kinetic isotope effects (KIEs) averaged 3.7 ± 0.5‰ for slurries prepared with sediment collected at an intertidal mudflat in San Francisco Bay and 2.7 ± 0.2‰ for a pure culture of Pelobacter sp. isolated from these sediments. A similar KIE of 1.8 ± 0.7‰ was obtained for methanogenic enrichments derived from sediment collected at freshwater Searsville Lake, California. However, C2H2 uptake by a highly enriched mixed culture (strain SV7) obtained from Searsville Lake sediments resulted in a larger KIE of 9.0 ± 0.7‰. These are modest KIEs when compared with fractionation observed during oxidation of C1 compounds such as methane and methyl halides but are comparable to results obtained with other C2 compounds. These observations may be useful in distinguishing biologically active processes operating at distant locales in the Solar System where C2H2 is present. These locales include the surface of Saturn's largest moon Titan and the vaporous water- and hydrocarbon-rich jets emanating from Enceladus. Acetylene-Fermentation-Isotope fractionation-Enceladus-Life detection.

  6. Synergism of cattle and bison inoculum on ruminal fermentation and select bacterial communities in an artificial rumen (Rusitec fed barley straw

    Directory of Open Access Journals (Sweden)

    Daniela B Oss

    2016-12-01

    Full Text Available This study evaluated the effect of increasing the proportion of bison relative to cattle inoculum on fermentation and microbial populations within an artificial rumen (Rusitec. The experiment was a completely randomized design with a factorial treatment structure (proportion cattle:bison inoculum; 0:100, 33:67, 67:33 and 100:0 replicated in two Rusitec apparatuses (n=8 fermenters. The experiment was 15 d with 8 d of adaptation and 7 d of sampling. Fermenters were fed a diet of 70:30 barley straw:concentrate (DM basis. True digestibility of DM was determined after 48 h of incubation from d 13-15, and daily ammonia (NH3 and volatile fatty acid (VFA production were measured on d 9-12. Protozoa counts were determined at d 9, 11, 13 and 15 and particle-associated bacteria (PAB from d 13-15. Select bacterial populations in the PAB were measured using RT-qPCR. Fermenter was considered the experimental unit and day of sampling as a repeated measure. Increasing the proportion of bison inoculum resulted in a quadratic effect (P0.05. Increasing bison inoculum linearly increased (P<0.05 concentrate aNDF disappearance, total and concentrate N disappearance as well as total daily VFA and acetate production. A positive quadratic response (P<0.05 was observed for daily NH3-N, propionate, butyrate, valerate, isovalerate and isobutyrate production, as well as the acetate:propionate ratio. Increasing the proportion of bison inoculum linearly increased (P<0.05 total protozoa numbers. No effects were observed on pH, total gas and methane production, microbial N synthesis, or copies of 16S rRNA associated with total bacteria, Selenomonas ruminantium or Prevotella bryantii. Increasing bison inoculum had a quadratic effect (P<0.05 on Fibrobacter succinogenes, and tended to linearly (P<0.10 increase Ruminococcus flavefaciens and decrease (P<0.05 Ruminococcus albus copy numbers. In conclusion, bison inoculum increased the degradation of feed protein and fibre. A mixture

  7. New lactic acid bacterial strains from traditional Mongolian fermented milk products have altered adhesion to porcine gastric mucin depending on the carbon source.

    Science.gov (United States)

    Kimoto-Nira, Hiromi; Yamasaki, Seishi; Sasaki, Keisuke; Moriya, Naoko; Takenaka, Akio; Suzuki, Chise

    2015-03-01

    Attachment of lactic acid bacteria to the mucosal surface of the gastrointestinal tract is a major property of probiotics. Here, we examined the ability of 21 lactic acid bacterial strains isolated from traditional fermented milk products in Mongolia to adhere to porcine gastric mucin in vitro. Higher attachment was observed with Lactobacillus delbrueckii subsp. bulgaricus strains 6-8 and 8-1 than with Lactobacillus rhamnosus GG (positive control). Lactococcus lactis subsp. cremoris strain 7-1 adhered to mucin as effectively as did strain GG. Heat inactivation decreased the adhesive ability of strains 6-8 and 8-1 but did not affect strain 7-1. The adhesion of strains 6-8, 7-1 and 8-1 was significantly inhibited when the cells were pretreated with periodate and trypsin, indicating that proteinaceous and carbohydrate-like cell surface compounds are involved in the adhesion of these strains. The adhesion of strain 7-1 was affected by the type of carbohydrate present in the growth medium, being higher with fructose than with lactose, galactose or xylose as the carbon source. The sugar content of 7-1 cells grown on various carbohydrates was negatively correlated with its adhesive ability. We provide new probiotic candidate strains and new information regarding carbohydrate preference that influences lactic acid bacterial adhesion to mucin. © 2014 Japanese Society of Animal Science.

  8. Zinc Improves Biocontrol of Fusarium Crown and Root Rot of Tomato by Pseudomonas fluorescens and Represses the Production of Pathogen Metabolites Inhibitory to Bacterial Antibiotic Biosynthesis.

    Science.gov (United States)

    Duffy, B K; Défago, G

    1997-12-01

    ABSTRACT Crown and root rot of tomato caused by Fusarium oxysporum f. sp. radicis-lycopersici is an increasing problem in Europe, Israel, Japan, and North America. The biocontrol agent Pseudomonas fluorescens strain CHA0 provides only moderate control of this disease. A one-time amendment of zinc EDTA at 33 mug of Zn(2+)/ml to hydroponic nutrient solution in soilless rockwool culture did not reduce disease when used alone, but did reduce disease by 25% in the presence of CHA0. In in vitro studies with the pathogen, zinc at concentrations as low as 10 mug/ml abolished production of the phytotoxin fusaric acid, a Fusarium pathogenicity factor, and increased production of microconidia over 100-fold, but reduced total biomass. Copper EDTA at 33 mug of Cu(2+)/ml had a similar effect as zinc on the pathogen in vitro; it reduced disease when used alone, and increased the biocontrol activity of CHA0 in soilless culture. Ammonium-molybdate neither improved the biocontrol activity of CHA0 nor affected production of fusaric acid or microconidia. Strain CHA0 did not degrade fusaric acid. Fusaric acid at concentrations as low as 0.12 mug/ml repressed production by CHA0 of the antibiotic 2,4-diacetylphloroglucinol, a key factor in the biocontrol activity of this strain. Production of pyoluteorin by CHA0 was also reduced, but production of hydrogen cyanide and protease was not affected, suggesting that fusaric acid affects biosynthesis at a regulatory level downstream of gacA and apdA genes. Fusaric acid did not affect the recovery of preformed antibiotics nor did it affect bacterial growth even at concentrations as high as 200 mug/ml. When microbial meta-bolite production was measured in the rockwool bioassay, zinc amendments reduced fusaric acid production and enhanced 2,4-diacetylphloro-glucinol production. We suggest that zinc, which did not alleviate the repression of antibiotic biosynthesis by fusaric acid, improved biocontrol activity by reducing fusaric acid production by

  9. Flavonoid-rich agro-industrial residues for enhanced bacterial laccase production by submerged and solid-state fermentation.

    Science.gov (United States)

    Sharma, Aarjoo; Gupta, Vijaya; Khan, Mussarat; Balda, Sanjeev; Gupta, Naveen; Capalash, Neena; Sharma, Prince

    2017-07-01

    Laccases have potential applications in industrial, biotechnological, and environmental set ups. Development of cost effective and efficient production technologies has gained significant attention in recent years. To enhance the laccase production from Rheinheimera sp. (Gram negative) using submerged fermentation (SmF) and from Lysinibacillus sp. (Gram positive) using solid-state fermentation (SSF), the inducing effect of various flavonoid-rich agro-industrial residues was investigated. Peels of citrus fruits, soybean meal, tofu dreg, lignin monomers, and lingo-cellulosic waste, used tea leaves and peels of onion and kiwi, paper, and dying industry effluents were tested as inducers. In SmF, 0.1% of soybean meal, tofu dreg, and powdered orange peel were best, enhancing the laccase production 2.57-, 2.11-, and 2.05-fold, respectively. In SSF, 10 mg (w/w) of used tata acti green tea leaves per 5 g of wheat bran, 1% pulp and paper industry effluent (agro based), and 1% wine made from Sygium cumini enhanced the laccase production 2.69-, 2.61-, and 2.09-fold, respectively. These results suggest the utilization of these flavonoid and phenolic-rich waste materials to be potential enhancers of industrially important laccase production.

  10. Effects of Bacterial Inoculants and Absorbents on Fermentation Properties and Chemical Composition of Fresh Sugar Beet Pulp Silage Using Laboratory silos

    Directory of Open Access Journals (Sweden)

    Saeid Seidali Dolat-Abad

    2016-04-01

    Full Text Available Introduction Ensiling is one of the common preserving methods for forage or other organic materials. In this method, organic matters were preserved by proving an aerobic condition and then by reducing the pH with increasing acids production (mainly lactic acid. Some circumstances like enough soluble carbohydrates, low buffering capacity and appropriate dry matter concentration are needed in ensilages for an ideal silage production. Seepage production during ensiling is one of the most problems especially when high moisture materials (like fresh beet sugar pulp are ensiled. Silage seepage can pollute the environment and make loses in nutrients like soluble carbohydrates, protein, organic acids and etc. Moreover, lactic acid bacteria inoculants (Mainly consist of Lactobacillus plantarum have been widely used for improving fermentation pattern in ensilages. These external provided bacteria usually enhance lactic acid production in silage and then accelerate the falling of pH values in silages. Rapid decrease in pH can inhibit non-beneficial bacteria from activity which finally preserves nutrients from un-necessary fermentation or oxidation. The aim of this study was to investigate the interactive effects of lactic acid bacteria inoculants and some absorbents (straw and pith on chemical properties and fermentation profile of wet sugar beet pulp silage. Materials and Methods In the first experiment, fresh wet sugar beet pulp was treated with 5% straw or 5% pith in order to investigate the effects of these absorbents on chemical composition, fermentation characteristics and effluent production during ensiling period. In the second experiment, fresh wet sugar beet pulp was treated with a commercial lactic acid bacteria inoculants (Ecosyle and/or 5% pith in order to investing the main and interaction effects of the bacterial bacteria inoculants and the best absorbents from the experiment 1. In both experiments, triplicate samples were prepared for each

  11. Comparative study on the in vitro effects of Pseudomonas aeruginosa and seaweed alginates on human gut microbiota.

    Directory of Open Access Journals (Sweden)

    Shaofeng Bai

    Full Text Available Alginates pertain to organic polysaccharides that have been extensively used in food- and medicine-related industries. The present study obtained alginates from an alginate overproducing Pseudomonas aeruginosa PAO1 mutant by screening transposon mutagenesis libraries. The interaction between bacterial and seaweed alginates and gut microbiota were further studied by using an in vitro batch fermentation system. Thin-layer chromatography (TLC analysis indicated that both bacterial and seaweed alginates can be completely degraded by fecal bacteria isolated from study volunteers, indicating that a minor structural difference between bacterial and seaweed alginates (O-acetylation and lack of G-G blocks didn't affect the digestion of alginates by human microbiota. Although, the digestion of bacterial and seaweed alginates was attributed to different Bacteroides xylanisolvens strains, they harbored similar alginate lyase genes. Genus Bacteroides with alginate-degrading capability were enriched in growth medium containing bacterial or seaweed alginates after in vitro fermentation. Short-chain fatty acid (SCFA production in both bacterial and seaweed alginates was also comparable, but was significantly higher than the same medium using starch. In summary, the present study has isolated an alginate-overproducing P. aeruginosa mutant strain. Both seaweed and bacterial alginates were degraded by human gut microbiota, and their regulatory function on gut microbiota was similar.

  12. Bacterial Ecology of Fermented Cucumber Rising pH Spoilage as Determined by Nonculture-Based Methods.

    Science.gov (United States)

    Medina, Eduardo; Pérez-Díaz, Ilenys M; Breidt, Fred; Hayes, Janet; Franco, Wendy; Butz, Natasha; Azcarate-Peril, María Andrea

    2016-01-01

    Fermented cucumber spoilage (FCS) characterized by rising pH and the appearance of manure- and cheese-like aromas is a challenge of significant economical impact for the pickling industry. Previous culture-based studies identified the yeasts Pichia manshurica and Issatchenkia occidentalis, 4 Gram-positive bacteria, Lactobacillus buchneri, Lactobacillus parrafaraginis, Clostridium sp., and Propionibacterium and 1 Gram-negative genus, Pectinatus, as relevant in various stages of FCS given their ability to metabolize lactic acid. It was the objective of this study to augment the current knowledge of FCS using culture-independent methods to microbiologically characterize commercial spoilage samples. Ion Torrent data and 16S rRNA cloning library analyses of samples collected from commercial fermentation tanks confirmed the presence of L. rapi and L. buchneri and revealed the presence of additional species involved in the development of FCS such as Lactobacillus namurensis, Lactobacillus acetotolerans, Lactobacillus panis, Acetobacter peroxydans, Acetobacter aceti, and Acetobacter pasteurianus at pH below 3.4. The culture-independent analyses also revealed the presence of species of Veillonella and Dialister in spoilage samples with pH above 4.0 and confirmed the presence of Pectinatus spp. during lactic acid degradation at the higher pH. Acetobacter spp. were successfully isolated from commercial samples collected from tanks subjected to air purging by plating on Mannitol Yeast Peptone agar. In contrast, Lactobacillus spp. were primarily identified in samples of FCS collected from tanks not subjected to air purging for more than 4 mo. Thus, it is speculated that oxygen availability may be a determining factor in the initiation of spoilage and the leading microbiota. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

  13. Petroleum-hydrocarbons biodegradation by Pseudomonas strains ...

    African Journals Online (AJOL)

    Many indigenous microorganisms in water and soil are capable of degrading hydrocarbon contaminants. In this study, two bacterial strains were isolated from a contaminated soil of a refinery of Arzew (Oran). The isolated strains were identified as Pseudomonas aeruginosa (P3) and Pseudomonas fluoresens (P4).

  14. Bacterial fermentation of recombinant major wasp allergen Antigen 5 using oxygen limiting growth conditions improves yield and quality of inclusion bodies.

    Science.gov (United States)

    Kischnick, Stefanie; Weber, Bernhard; Verdino, Petra; Keller, Walter; Sanders, Ernst A; Anspach, F Birger; Fiebig, Helmut; Cromwell, Oliver; Suck, Roland

    2006-06-01

    A process for bacterial expression and purification of the recombinant major wasp allergen Antigen 5 (Ves v 5) was developed to produce protein for diagnostic and therapeutic applications for type 1 allergic diseases. Special attention was focused on medium selection, fermentation conditions, and efficient refolding procedures. A soy based medium was used for fermentation to avoid peptone from animal origin. Animal-derived peptone required the use of isopropyl-beta-D-thiogalactopyranoside (IPTG) for the induction of expression. In the case of soy peptone, a constitutive expression was observed, suggesting the presence of a component that mimics IPTG. Batch cultivation at reduced stirrer speed caused a reduced biomass due to oxygen limitation. However, subsequent purification and processing of inclusion bodies yielded significantly higher amount of product. Furthermore, the protein composition of the inclusion bodies differed. Inclusion bodies were denatured and subjected to diafiltration. Detailed monitoring of diafiltration enabled the determination of the transition point. Final purification was conducted using cation-exchange and size-exclusion chromatography. Purified recombinant Ves v 5 was analyzed by RP-HPLC, CD-spectroscopy, SDS-PAGE, and quantification ELISA. Up to 15 mg highly purified Ves v 5 per litre bioreactor volume were obtained, with endotoxin concentrations less than 20 EU mg(-1) protein and high comparability to the natural counterpart. Analytical results confirm the suitability of the recombinant protein for diagnostic and clinical applications. The results clearly demonstrate that not only biomass, but especially growth conditions play a key role in the production of recombinant Ves v 5. This has an influence on inclusion body formation, which in turn influences the renaturation rate and absolute product yield. This might also be true for other recombinant proteins that accumulate as inclusion bodies in Escherichia coli.

  15. Diversity of small RNAs expressed in Pseudomonas species

    DEFF Research Database (Denmark)

    Gomez-Lozano, Mara; Marvig, Rasmus Lykke; Molina-Santiago, Carlos

    2015-01-01

    RNA sequencing (RNA-seq) has revealed several hundreds of previously undetected small RNAs (sRNAs) in all bacterial species investigated, including strains of Pseudomonas aeruginosa, Pseudomonas putida and Pseudomonas syringae. Nonetheless, only little is known about the extent of conservation of...

  16. Antibiotic Conditioned Growth Medium of Pseudomonas Aeruginosa

    Science.gov (United States)

    Benathen, Isaiah A.; Cazeau, Barbara; Joseph, Njeri

    2004-01-01

    A simple method to study the consequences of bacterial antibiosis after interspecific competition between microorganisms is presented. Common microorganisms are used as the test organisms and Pseudomonas aeruginosa are used as the source of the inhibitor agents.

  17. Dietary Pectin-Derived Acidic Oligosaccharides Improve the Pulmonary Bacterial Clearance of Pseudomonas aeruginosa Lung Infection in Mice by Modulating Intestinal Microbiota and Immunity

    NARCIS (Netherlands)

    Bernard, H.; Desseyn, J.L.; Bartke, N.; Kleinjans, L.P.J.; Belzer, C.; Knol, J.; Gottrand, F.; Husson, M.O.

    2015-01-01

    Background. A predominantly T-helper type 2 (Th2) immune response is critical in the prognosis of pulmonary Pseudomonas aeruginosa infection. But the mucosal and systemic immune responses can be influenced by the intestinal microbiota. Methods. We assessed the effect of microbiota compositional

  18. Pseudomonas folliculitis in Arabian baths.

    Science.gov (United States)

    Molina-Leyva, Alejandro; Ruiz-Ruigomez, Maria

    2013-07-14

    A 35-year-old man presented with a painful cutaneous skin eruption that was localized on the upper trunk. He stated that the previous weekend he had attended an Arabian bath. The physical examination revealed multiple hair follicle-centered papulopustules surrounded by an erythematous halo. A clinical diagnosis of pseudomonas folliculitis was made and treatment was prescribed. Afterwards Pseudomonas aeruginosa was isolated from a pustule culture. Pseudomonas folliculitis is a bacterial infection of the hair follicles. The most common reservoirs include facilities with hot water and complex piping systems that are difficult to clean, such as hot tubs and bathtubs. Despite adequate or high chlorine levels, Pseudomonas aeruginosa can grow within a biofilm.

  19. Fermentation Tecniques and Applications of Bacterial Cellulose: a Review Técnicas de fermentación y aplicaciones de la celulosa bacteriana: una revisión

    Directory of Open Access Journals (Sweden)

    Luz Dary Carreño Pineda

    2012-12-01

    Full Text Available Bacterial cellulose is a polymer obtained by fermentation with microorganismsfrom Acetobacter, Rhizobium, Agrobacterium and Sarcina genera. Amongthem, Acetobacter xylinum is the most efficient specie. This polymer hasthe same chemical composition of plant cellulose, but its conformation andphysicochemical properties are different, making it attractive for several applications, especially in the areas of food, separation processes, catalysis andhealth, due to its biocompatibility. However, the main problem is the production in mass that is constrained by low yield. It is therefore necessaryto develop some alternatives. This paper presents a review about synthesis,production, properties and principal applications of bacterial cellulose, as wellas some alternatives to reduce the difficulties for process scaling.La celulosa bacteriana es un polímero obtenido por fermentación con microrganismosde los géneros Acetobacter, Rhizobium, Agrobacterium y Sarcina, delas cuales la especie más eficiente es la Acetobacter Xylinum. Este polímero presenta la misma estructura química de la celulosa de origen vegetal, pero difiereen su conformación y propiedades fisicoquímicas, lo que lo hace atractivo para diversas aplicaciones, especialmente en las áreas de alimentos, procesosde separación, catálisis y en medicina, gracias a su biocompatibilidad. Sin embargo, el principal problema es la producción a gran escala limitada por losbajos rendimientos, lo que genera la necesidad de desarrollar alternativas que permitan disminuir o eliminar las causas de esta limitación. En este artículo se hace una revisión acerca de la síntesis, producción, propiedades y principales aplicaciones de la celulosa bacteriana, así como de algunas alternativas estudiadas para disminuir los inconvenientes en el escalamiento del proceso.

  20. Pseudomonas-follikulitis efter badning i spabad

    DEFF Research Database (Denmark)

    Uldall Pallesen, Kristine Appel; Andersen, Klaus Ejner; Mørtz, Charlotte Gotthard

    2012-01-01

    Pseudomonas aeruginosa is a rare cause of folliculitis. Pseudomonas folliculitis can develop after contact with contaminated water from swimming pools, hot tubs and spa baths. Systemic therapy may be indicated in patients with widespread lesions, systemic symptoms or in immunosuppressed patients....... We describe a 23-year-old healthy woman who developed a pustular rash and general malaise after using a spa bath contaminated with Pseudomonas aeruginosa. Bacterial culture from a pustule confirmed Pseudomonas folliculitis and the patient was treated with ciprofloxacin with rapid good effect....

  1. Nutritional evaluation of soybean meal after fermentation with two fish gut bacterial strains, Bacillus cereus LRF5 and Staphylococcus caprae CCF2 in for-mulated diets for Labeo rohita fingerlings

    Directory of Open Access Journals (Sweden)

    Suhas Kumar Dan

    2017-04-01

    Full Text Available Twelve isonitrogenous (35 % crude protein and isocaloric (18.0 kJ/g diets were formulated incorporating raw and fermented soybean meal (SBM at 15%, 30%, 45% and 60% levels by weight. Two phytase-producing bacterial strains, Bacillus cereus LRF5 and Staphylococcus caprae CCF2 isolated from the gut of adult Labeo rohita and Catla catla, respectively were used for fermentation of SBM. Fermentation of SBM was effective in reducing the anti-nutritional factors, trypsin inhibitor and phytic acid and enhancing protein, lipid and mineral concentration. The response of L. rohita, fingerlings (initial weight 3.33±0.07 g fed the experimental diets for 100 days was compared with fish fed a fish meal based diet. In terms of growth, feed conversion ratio and protein efficiency ratio, diet S7 containing 45% SBM fermented with B. cereus LRF5 resulted in a significantly (P<0.05 better performance of fish. The overall performance of L. rohita fed fermented SBM incorporated diets was better in comparison to those fed raw SBM incorporated diets. The apparent digestibility of nutrients and minerals was significantly (P<0.05 higher in fish fed diet S7. The maximum deposition of protein in the carcass was recorded in fish fed diet S7. Diets containing fermented SBM reduced fecal P levels. The use of this fermented feed will definitely increase the production in fish farm. Furthermore, it will also reduce the production cost, as fish meal protein is costly in the market.

  2. Stable carbon isotope fractionation during bacterial acetylene fermentation: Potential for life detection in hydrocarbon-rich volatiles of icy planet(oid)s

    Science.gov (United States)

    Miller, Laurence; Baesman, Shaun; Oremland, Ron

    2015-01-01

    We report the first study of stable carbon isotope fractionation during microbial fermentation of acetylene (C2H2) in sediments, sediment enrichments, and bacterial cultures. Kinetic isotope effects (KIEs) averaged 3.7 ± 0.5‰ for slurries prepared with sediment collected at an intertidal mudflat in San Francisco Bay and 2.7 ± 0.2‰ for a pure culture of Pelobacter sp. isolated from these sediments. A similar KIE of 1.8 ± 0.7‰ was obtained for methanogenic enrichments derived from sediment collected at freshwater Searsville Lake, California. However, C2H2 uptake by a highly enriched mixed culture (strain SV7) obtained from Searsville Lake sediments resulted in a larger KIE of 9.0 ± 0.7‰. These are modest KIEs when compared with fractionation observed during oxidation of C1 compounds such as methane and methyl halides but are comparable to results obtained with other C2compounds. These observations may be useful in distinguishing biologically active processes operating at distant locales in the Solar System where C2H2 is present. These locales include the surface of Saturn's largest moon Titan and the vaporous water- and hydrocarbon-rich jets emanating from Enceladus.

  3. Inhibition of spoilage and food-borne pathogens by lactic acid bacteria isolated from fermenting tef (Eragrostis tef) dough.

    Science.gov (United States)

    Nigatu, A; Gashe, B A

    1994-10-01

    A study was carried out at the Department of Biology, Addis Abeba University, in 1991 to determine the inhibitory potential of fermenting tef and the lactic acid bacteria isolated from fermenting tef dough on Salmonella spp., Pseudomonas aeruginosa, Klebsiella spp., Bacillus cereus and Staphylococcus aureus. The test bacteria grew in the fermenting tef uptill 30 hr or till the pH dropped to 4.7. Thereafter, growth was inhibited and decreases in population were apparent. The results showed that the spent media from all of the four lactic acid bacterial isolates, namely, Lactobacillus spp., Pediococcus spp., Leuconostoc spp. and Streptococcus spp. inhibited the test bacteria. Acidity on its own was not responsible for the inhibition of the test bacteria. The spent medium from Streptococcus spp. showed the best inhibitory activity amongst the lactic acid bacteria.

  4. UTILIZATION OF MUSTARD OIL FOR THE PRODUCTION OF POLYHYDROXYALKANOATES BY Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Hasnain Javed

    2015-04-01

    Full Text Available With the unnecessary use of plastics and cumulative pressure being placed on capacities available for plastic waste disposal, the need for biodegradable plastics and biodegradation of plastic wastes has assumed increasing importance in the last few years. Bioplastic production from mustard oil was considered relatively cheap, easily available, included in vegetable oil and don’t having much volatile characteristics. Total of 67 bacterial strains were isolated and purified from different regions of the Pakistan, and were checked for Polyhydroxyalkanoates (PHA production by Sudan black and Nile blue staining. Quantitative analysis for biodegradable plastic produced by different bacterial species was performed by Modified surfactant hypochlorite method. High PHA production was detected in 35 strains belonging to different genera including Pseudomonas, Staphylococcus, Escherichia and Enterobacter. Fermentation and PHA production was done in batch culture. The PHA production of P. aeruginosa by mustered oil cultivation was studied under six experimental conditions, such as air flow rates, pH, Temperature, optical density, substrates concentration and cell dry weight. PHA production of Pseudomonas species were subsequently authenticated at molecular level by PCR amplifications and sequence analysis. PHA polymerase 1 (PhaC1 and PHA polymerase 2 (PhaC2 from Pseudomonas aeruginosa were amplified, sequenced and submitted to gene bank.

  5. Enhanced alpha-galactosidase expression in pseudomonas chlororaphis

    Science.gov (United States)

    Pseudomonas chlororaphis is a non-pathogenic bacterium useful for fermentative production of biopolymer (i.e., poly(hydroxyalkanoates); PHA) and biosurfactant (i.e., rhamnolipid; RhL). In order to enable P. chlororaphis to better fermentatively utilize the residual soy sugars in soy molasses – a lo...

  6. Growth of Pseudomonas fluorescens on Cassava Starch ...

    African Journals Online (AJOL)

    This involved hydrolysis of starch extracted from freshly harvested cassava tubers using enzyme-enzyme method of hydrolysis, followed by aerobic fermentation of Pseudomonas fluorescens on a mixture of the hydrolysate and nutrient media in a fermentor in batch cultures. The reducing sugar hydrolysate served as the ...

  7. Optimization of alkaline protease production from Pseudomonas ...

    African Journals Online (AJOL)

    A protease producing bacteria was isolated from meat waste contaminated soil and identified as Pseudomonas fluorescens. Optimization of the fermentation medium for maximum protease production was carried out. The culture conditions like inoculum concentration, incubation time, pH, temperature, carbon sources, ...

  8. Anti-Pseudomonas aeruginosa IgY Antibodies Induce Specific Bacterial Aggregation and Internalization in Human Polymorphonuclear Neutrophils

    DEFF Research Database (Denmark)

    Thomsen, K.; Christophersen, L.; Bjarnsholt, T.

    2015-01-01

    is attributed to IgY-facilitated formation of immobilized bacteria in aggregates, as visualized by fluorescence microscopy and the induction of increased bacterial hydrophobicity. Thus, the present study demonstrates that avian egg yolk immunoglobulins (IgY) targeting P. aeruginosa modify bacterial fitness...

  9. Bacterial consortia at different wine fermentation phases of two typical Central European grape varieties: Blaufränkisch (Frankovka modrá) and Grüner Veltliner (Veltlínske zelené).

    Science.gov (United States)

    Godálová, Zuzana; Kraková, Lucia; Puškárová, Andrea; Bučková, Mária; Kuchta, Tomáš; Piknová, Ľubica; Pangallo, Domenico

    2016-01-18

    This is the first study focused to bacterial diversity and dynamic during the vinification of two important Central Europe grape vines: Blaufränkisch and Grüner Veltliner. The investigation strategy included culture-dependent and culture-independent approaches. Four different agar media were utilized for the isolation of various bacteria occurring in several fermentation stages. The isolates were clustered by fluorescent-ITS PCR and, one or more representatives of each cluster, were identified by 16 rRNA gene sequencing. The culture-independent approach, based on 16S rRNA gene amplification, combined the denaturing gradient gel electrophoresis (DGGE) method and the construction of bacterial clone library for each wine fermentation step. A complex bacterial community was identified, comprising different lactic acid bacteria and acetic acid bacteria, such as Leuconostoc spp., Lactobacillus spp. and Gluconobacter spp. Other OTUs and bacterial isolates embraced the Actinobacteria, Bacilli, Alpha-, Beta- and Gamma-proteobacteria classes. Different taxa already detected by recent studies, such as Sphingomonas, Variovorax, Pantoea, Enterobacter and Tatumella, were detected confirming the continuous occurrence of these kinds of bacteria in wine environment. Moreover, novel genera (Amycolatopsis, Hydrogenophilus, Snodgrassella, Telluria, Gilliamella, Lelliottia, and Lonsdale quercina) never detected before were recognized, too. The role of these, until now anonymous, bacteria during vinification deserves investigation, which could open a new research field in wine technology. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Laboratory silo type and inoculation effects on nutritional composition, fermentation, and bacterial and fungal communities of oat silage.

    Science.gov (United States)

    Romero, J J; Zhao, Y; Balseca-Paredes, M A; Tiezzi, F; Gutierrez-Rodriguez, E; Castillo, M S

    2017-03-01

    The objectives were to evaluate (1) the use of 2 types of experimental silos (S) to characterize whole-crop oat (Avena sativa L.) silage with or without addition of an inoculant (I), and (2) the effect of inoculation on the microbial community structure of oats ensiled using only plastic bucket silos (BKT). From each of 6 sections in a field, oats were harvested, treated (INO) or not (CON) with inoculant, packed into 19-L BKT or vacuum bags (BG), and ensiled for 217 d. The inoculant added contained Lactobacillus buchneri and Pediococcus pentosaceus (4 × 105 and 1 × 105 cfu/g of fresh oats, respectively). The experimental design was a complete randomized design replicated 6 times. Treatment design was the factorial combination of 2 S × 2 I. Some differences existed between BG versus BKT at silo opening (217 d), including a decreased CP (7.73 vs. 7.04 ± 0.247% of DM) and ethanol (1.93 vs. 1.55 ± 0.155) and increased lactic acid (4.28 vs. 3.65 ± 0.241), respectively. Also, WSC and mold counts were reduced in BG versus BKT for CON (1.78 vs. 2.70 ± 0.162% of DM and 0.8 vs. 2.82 ± 0.409 log cfu/fresh g) but not for INO (∼1.53 and 1.55), respectively. Application of INO increased DM recovery (96.1 vs. 92.9 ± 0.63%), aerobic stability (565 vs. 133 ± 29.2 h), acetic acid (2.38 vs. 1.22 ± 0.116% of DM), and reduced NDF (65.0 vs. 67.0 ± 0.57), ADF (36.7 vs. 38.1 ± 0.60), ethanol (0.63 vs. 2.85 ± 0.155), and yeast counts (1.10 vs. 4.13 ± 0.484 log cfu/fresh g) in INO versus CON, respectively. At d 0, no differences were found for S and I on the nutritional composition and background microbial counts. Leuconostocaceae (82.9 ± 4.27%) and Enterobacteriaceae (15.2 ± 3.52) were the predominant bacterial families and unidentified sequences were predominant for fungi. A higher relative abundance of the Davidiellaceae fungal family (34.3 vs. 19.6 ± 4.47) was observed in INO versus CON. At opening (217 d), INO had a lower relative abundance of Leuconostocaceae (42

  11. Production of Medium Chain Length Polyhydroxyalkanoates From Oleic Acid Using Pseudomonas putida PGA1 by Fed Batch Culture

    Directory of Open Access Journals (Sweden)

    Sidik Marsudi

    2010-10-01

    Full Text Available Bacterial polyhydroxyalkanoates (PHAs are a class of p0lymers currently receiving much attention because of their potential as renewable and biodegradable plastics. A wide variety of bacteria has been reported to produce PHAs including Pseudomonas strains. These strains are known as versatile medium chain length PHAs (PHAs-mcl producers using fatty acids as carbon source. Oleic acid was used to produce PHAs-mcl using Pseudomonas putida PGA 1 by continuous feeding of both nitrogen and carbon source, in a fed batch culture. During cell growth, PHAs also accumulated, indicating that PHA production in this organism is growth associated. Residual cell increased until the nitrogen source was depleted. At the end of fermentation, final cell concentration, PHA content, and roductivity were 30.2 g/L, 44.8 % of cell dry weight, and 0.188 g/l/h, respectively.

  12. Enzymes in Fermented Fish.

    Science.gov (United States)

    Giyatmi; Irianto, H E

    Fermented fish products are very popular particularly in Southeast Asian countries. These products have unique characteristics, especially in terms of aroma, flavor, and texture developing during fermentation process. Proteolytic enzymes have a main role in hydrolyzing protein into simpler compounds. Fermentation process of fish relies both on naturally occurring enzymes (in the muscle or the intestinal tract) as well as bacteria. Fermented fish products processed using the whole fish show a different characteristic compared to those prepared from headed and gutted fish. Endogenous enzymes like trypsin, chymotrypsin, elastase, and aminopeptidase are the most involved in the fermentation process. Muscle tissue enzymes like cathepsins, peptidases, transaminases, amidases, amino acid decarboxylases, glutamic dehydrogenases, and related enzymes may also play a role in fish fermentation. Due to the decreased bacterial number during fermentation, contribution of microbial enzymes to proteolysis may be expected prior to salting of fish. Commercial enzymes are supplemented during processing for specific purposes, such as quality improvement and process acceleration. In the case of fish sauce, efforts to accelerate fermentation process and to improve product quality have been studied by addition of enzymes such as papain, bromelain, trypsin, pepsin, and chymotrypsin. © 2017 Elsevier Inc. All rights reserved.

  13. Bacterial Contaminants of Salad Vegetables in Abuja Municipal Area Council, Nigeria

    Directory of Open Access Journals (Sweden)

    Itohan, A. M.

    2011-01-01

    Full Text Available Salad vegetables are essential part of people’s diet all around the world. They are usually consumed raw and often without heat treatment or thorough washing; hence have been known to serve as vehicles for the transmission of pathogenic microorganism associated with human diseases. Fresh samples of lettuce, carrot and cucumber collected from different markets and vendors in Abuja Municipal Area Council, Federal Capital Territory, Nigeria were evaluated for bacterial loads using spread plate agar dilution method. Bacterial loads ranged from 1.6 x 106 to 2.9 x 108 cfu/g. Escherichia coli, Klebsiella and Enterobacter were amongst the coliforms (lactose fermenters, while Proteus, Pseudomonas aeruginosa, Salmonella and Shigella were non-lactose fermenters associated with the samples. Staphylococcus aureus was isolated from majority of the samples.

  14. Dynamics of bacterial communities during solid-state fermentation using agro-industrial wastes to produce poly-γ-glutamic acid, revealed by real-time PCR and denaturing gradient gel electrophoresis (DGGE).

    Science.gov (United States)

    Yong, Xiaoyu; Cui, Yaqing; Chen, Lihua; Ran, Wei; Shen, Qirong; Yang, Xingming

    2011-11-01

    The dynamics of bacterial communities play an important role in solid-state fermentation (SSF). Poly-γ-glutamic acid (γ-PGA) was produced by Bacillus amyloliquefaciens C1 in SSF using dairy manure compost and monosodium glutamate production residuals as basic substrates. The production of γ-PGA reached a maximum of 0.6% after 20 days fermentation. Real-time polymerase chain reaction showed the amount of total bacteria reached 3.95 × 10(9) 16S rDNA copies/g sample after 30 days, which was in good accordance with the 4.80 × 10(9) CFU/g obtained by plate counting. Denaturing gradient gel electrophoresis profile showed a reduction of microbial diversity during fermentation, while the inoculum, B. amyloliquefaciens C1, was detected as the dominant organism through the whole process. In the mesophilic phase of SSF, Proteobacteria was the dominant microbial, which was replaced by Firmicutes and Actinobacteria in the thermophilic phase. The molecular analysis of the bacterial diversity has significant potential for instructing the maturing process of SSF to produce γ-PGA at a large-scale level, which could be a benefit in the production of high quality and stable SSF products. © Springer-Verlag 2011

  15. Antibiograms of Staphylococcus Aureus and Pseudomonas ...

    African Journals Online (AJOL)

    While there was no bacterial growth after 48hrs incubation recorded for group one, only 5(13.9%) samples yielded growth of Staphylococcus aureus for group two with 31(86.1%) yielding no bacterial growth. All group three samples yielded profuse growth of which 11(36.7%) yielded Pseudomonas aeruginosa and ...

  16. Pseudomonas moraviensis subsp. stanleyae, a bacterial endophyte of hyperaccumulator Stanleya pinnata, is capable of efficient selenite reduction to elemental selenium under aerobic conditions

    NARCIS (Netherlands)

    Staicu, L. C.; Ackerson, C. J.; Cornelis, P.; Ye, L.; Berendsen, R. L.; Hunter, W. J.; Noblitt, S. D.; Henry, C. S.; Cappa, J. J.; Montenieri, R. L.; Wong, A. O.; Musilova, L.; Sura-de Jong, M.; van Hullebusch, E. D.; Lens, P. N L; Reynolds, R. J B; Pilon-Smits, Elizabeth A H

    2015-01-01

    Aims: To identify bacteria with high selenium tolerance and reduction capacity for bioremediation of wastewater and nanoselenium particle production. Methods and Results: A bacterial endophyte was isolated from the selenium hyperaccumulator Stanleya pinnata (Brassicaceae) growing on seleniferous

  17. PARTIAL PURIFICATION AND CHARACTERIZATION OF ALKALOPHILIC PROTEASE FROM PSEUDOMONAS AERUGINOSA

    Directory of Open Access Journals (Sweden)

    R. Satheeskumar

    2013-10-01

    Full Text Available Partial purification and characterization of alkalophilic protease production from Pseudomonas aeruginosa was isolated from the gut of marine and coastal waters shrimp Penaeus monodon. The protease production was assayed in submerged fermentation to produce maximum protease activity (423 ± 0.09 U/ml. The enzyme was precipitated with ammonium sulphate and partially purified by ion exchange chromatography through DEAE Sephadex A-50 column. In 10th fraction showed maximum protease activity (734 ± 0.18 U/ml with increase in purification fold. The molecular weight of protease from Pseudomonas aeruginosa was recorded as 60 kDa. The stability of protease was tested at various pH and temperature; it showed maximum protease activity at pH-9 and temperature 50ºC. Among the various surfactants tested for enzyme stability, maximum activity was retained in poly ethylene glycol. The compatibility of protease enzyme with various commercial detergents; the enzyme retained maximum protease activity in tide. The results are indicated that all these properties make the bacterial proteases are most suitable for wide industrial applications.

  18. Investigation of lactic acid bacterial strains for meat fermentation and the product's antioxidant and angiotensin-I-converting-enzyme inhibitory activities.

    Science.gov (United States)

    Takeda, Shiro; Matsufuji, Hisashi; Nakade, Koji; Takenoyama, Shin-Ichi; Ahhmed, Abdulatef; Sakata, Ryoichi; Kawahara, Satoshi; Muguruma, Michio

    2017-03-01

    In the lactic acid bacteria (LAB) strains screened from our LAB collection, Lactobacillus (L.) sakei strain no. 23 and L. curvatus strain no. 28 degraded meat protein and tolerated salt and nitrite in vitro. Fermented sausages inoculated strains no. 23 and no. 28 showed not only favorable increases in viable LAB counts and reduced pH, but also the degradation of meat protein. The sausages fermented with these strains showed significantly higher antioxidant activity than those without LAB or fermented by each LAB type strain. Angiotensin-I-converting-enzyme (ACE) inhibitory activity was also significantly higher in the sausages fermented with strain no. 23 than in those fermented with the type strain. Higher ACE inhibitory activity was also observed in the sausages fermented with strain no. 28, but did not differ significantly from those with the type strain. An analysis of the proteolysis and degradation products formed by each LAB in sausages suggested that those bioactivities yielded fermentation products such as peptides. Therefore, LAB starters that can adequately ferment meat, such as strains no. 23 and no. 28, should contribute to the production of bioactive compounds in meat products. © 2016 Japanese Society of Animal Science.

  19. COEXISTENCE OF BACTERIAL INFECTION IN SPUTUM POSITIVE PULMONARY TUBERCULOSIS

    Directory of Open Access Journals (Sweden)

    Shashi Bhushan

    2015-12-01

    Full Text Available AIM AND OBJECTIVES To study the coexistence of bacterial infection among patients with confirmed sputum positive pulmonary tuberculosis. METHODS Study conducted at department of pulmonary medicine Victoria Hospital Bangalore, Karnataka, India, from January 2015 to June 2015 in confirmed positive sputum pulmonary tuberculosis patient, all patients were subjected for sputum gram staining and culture and sensitivity and checked for bacterial growth. RESULTS Total 150 patients were confirmed to have sputum positive pulmonary tuberculosis from January 2015 to June 2015 both inpatient and outpatient were subjected to undergo sputum gram stain and culture and sensitivity with the following growth Klebsiella 40% E coli 15.33% Pseudomonas 9.33% Pneumococci 4.66% gram negative non fermenters 2.66% methicillin resistant Staphylococcus aureus 1.33% Citrobacter 1.33% Enterobacter 1.33%, Serratia/Staphylococci aureus/Proteus .66%. CONCLUSION The most common secondary infection observed out of 150 patients is Klebsiella which is seen in 60 patients followed by E coli in 23 patients, pseudomonas in 14 patients Pneumococci in 7 pt gram negative non fermenter 4 pt, Methicillin resistant Staph aureus, Citrobacter, Enterobacter in 2 patients each Serratia, Proteus, Staphylococcus aureus in 1 patient each.

  20. A ptsP deficiency in PGPR Pseudomonas fluorescens SF39a affects bacteriocin production and bacterial fitness in the wheat rhizosphere.

    Science.gov (United States)

    Godino, Agustina; Príncipe, Analía; Fischer, Sonia

    2016-04-01

    Pseudomonas fluorescens SF39a is a plant-growth-promoting bacterium isolated from wheat rhizosphere. In this report, we demonstrate that this native strain secretes bacteriocins that inhibit growth of phytopathogenic strains of the genera Pseudomonas and Xanthomonas. An S-type pyocin gene was detected in the genome of strain SF39a and named pys. A non-polar pys::Km mutant was constructed. The bacteriocin production was impaired in this mutant. To identify genes involved in bacteriocin regulation, random transposon mutagenesis was carried out. A miniTn5Km1 mutant, called P. fluorescens SF39a-451, showed strongly reduced bacteriocin production. This phenotype was caused by inactivation of the ptsP gene which encodes a phosphoenolpyruvate phosphotransferase (EI(Ntr)) of the nitrogen-related phosphotransferase system (PTS(Ntr)). In addition, this mutant showed a decrease in biofilm formation and protease production, and an increase in surface motility and pyoverdine production compared with the wild-type strain. Moreover, we investigated the ability of strain SF39a-451 to colonize the wheat rhizosphere under greenhouse conditions. Interestingly, the mutant was less competitive than the wild-type strain in the rhizosphere. To our knowledge, this study provides the first evidence of both the relevance of the ptsP gene in bacteriocin production and functional characterization of a pyocin S in P. fluorescens. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  1. Characterization of Cichopeptins, New Phytotoxic Cyclic Lipodepsipeptides Produced by Pseudomonas cichorii SF1-54 and Their Role in Bacterial Midrib Rot Disease of Lettuce.

    Science.gov (United States)

    Huang, Chien-Jui; Pauwelyn, Ellen; Ongena, Marc; Debois, Delphine; Leclère, Valerie; Jacques, Philippe; Bleyaert, Peter; Höfte, Monica

    2015-09-01

    The lettuce midrib rot pathogen Pseudomonas cichorii SF1-54 produces seven bioactive compounds with biosurfactant properties. Two compounds exhibited necrosis-inducing activity on chicory leaves. The structure of the two phytotoxic compounds, named cichopeptin A and B, was tentatively characterized. They are related cyclic lipopeptides composed of an unsaturated C12-fatty acid chain linked to the N-terminus of a 22-amino acid peptide moiety. Cichopeptin B differs from cichopeptin A only in the last C-terminal amino acid residue, which is probably Val instead of Leu/Ile. Based on peptide sequence similarity, cichopeptins are new cyclic lipopeptides related to corpeptin, produced by the tomato pathogen Pseudomonas corrugata. Production of cichopeptin is stimulated by glycine betaine but not by choline, an upstream precursor of glycine betaine. Furthermore, a gene cluster encoding cichopeptin synthethases, cipABCDEF, is responsible for cichopeptin biosynthesis. A cipA-deletion mutant exhibited significantly less virulence and rotten midribs than the parental strain upon spray inoculation on lettuce. However, the parental and mutant strains multiplied in lettuce leaves at a similar rate. These results demonstrate that cichopeptins contribute to virulence of P. cichorii SF1-54 on lettuce.

  2. Changes in flavour and microbial diversity during natural fermentation of suan-cai, a traditional food made in Northeast China.

    Science.gov (United States)

    Wu, Rina; Yu, Meiling; Liu, Xiaoyu; Meng, Lingshuai; Wang, Qianqian; Xue, Yating; Wu, Junrui; Yue, Xiqing

    2015-10-15

    We measured changes in the main physical and chemical properties, flavour compounds and microbial diversity in suan-cai during natural fermentation. The results showed that the pH and concentration of soluble protein initially decreased but were then maintained at a stable level; the concentration of nitrite increased in the initial fermentation stage and after reaching a peak it decreased significantly to a low level by the end of fermentation. Suan-cai was rich in 17 free amino acids. All of the free amino acids increased in concentration to different degrees, except histidine. Total free amino acids reached their highest levels in the mid-fermentation stage. The 17 volatile flavour components identified at the start of fermentation increased to 57 by the mid-fermentation stage; esters and aldehydes were in the greatest diversity and abundance, contributing most to the aroma of suan-cai. Bacteria were more abundant and diverse than fungi in suan-cai; 14 bacterial species were identified from the genera Leuconostoc, Bacillus, Pseudomonas and Lactobacillus. The predominant fungal species identified were Debaryomyces hansenii, Candida tropicalis and Penicillium expansum. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Increase of “Umami” and “Kokumi” Compounds in Miso, Fermented Soybeans, by the Addition of Bacterial γ-Glutamyltranspeptidase

    Directory of Open Access Journals (Sweden)

    Thao Van Ho

    2013-04-01

    Full Text Available γ-Glutamyltranspeptidase (GGT hydrolyzes γ-glutamyl compounds and transfers their γ-glutamyl moieties to amino acids and peptides.  We previously showed that the “umami” taste of soy sauce could be improved by the addition of salt-tolerant Bacillus subtilis GGT to the fermentation mixture, “moromi”.  Although miso fermentation is a semi-solid fermentation, unlike soy sauce fermentation, this was also the case. When 15 units of purified B. subtilis GGT were added to 418 g miso “moromi” (fermentation mixture, the glutamate concentration in “moromi” became 20 mM higher and the “umami” taste became stronger than without the addition of GGT after 2 to 6 months of fermentation.  In addition, γ-Glu-Val and γ-Glu-Val-Gly, which are known as “kokumi” peptides, were identified in “tamari”, and the concentrations of these γ-glutamyl peptides in “tamari" fermented by the addition of GGT were significantly higher than those of “moromi” without the addition of GGT.  These results indicate that B. subtilis GGT is able to improve the taste of miso.

  4. Bacterie remt phytophthora

    NARCIS (Netherlands)

    Knuivers, M.; Overbeek, van L.S.

    2009-01-01

    Bacteriën kunnen aardappelplanten weerbaarder maken tegen phytophthora. Uit kas-experimenten van Plant Research International (PRI) blijkt dat de aanwezigheid van de bacteriePseudomonas putida(isolaat P9) in twee late aardappelrassen leidt tot een vertraging met 45 procent van het ziekteverloop na

  5. A combined metabolomic and phylogenetic study reveals putatively prebiotic effects of high molecular weight arabino-oligosaccharides when assessed by in vitro fermentation in bacterial communities derived from humans

    DEFF Research Database (Denmark)

    Sulek, Karolina; Vigsnæs, Louise Kristine; Schmidt, Line Rieck

    2014-01-01

    Prebiotic oligosaccharides are defined by their selective stimulation of growth and/or activity of bacteria in the digestive system in ways claimed to be beneficial for health. However, apart from the short chain fatty acids, little is known about bacterial metabolites created by fermentation...... plant structures. Additionally, the combination of qPCR and LC–MS revealed a number of other putative interactions between intestinal microbes and the oligosaccharides, which contributes to the understanding of the mechanisms behind prebiotic impact on human health....

  6. Enhancement of antioxidant activity, α-glucosidase and α-amylase inhibitory activities by spontaneous and bacterial monoculture fermentation of Indonesian black grape juices

    Science.gov (United States)

    Frediansyah, Andri; Nurhayati, Rifa; Romadhoni, Fitrio

    2017-01-01

    This study was conducted to evaluate the in vitro antioxidant activity, α-glucosidase and α-amylase inhibitor activity of fermented black grape (Vitisvinifera) juice. In the present study black grape juice was prepared using spontaneous (SF) and monoculture fermentation (FL) of Lactobacillus plantarum FNCC 0027 and incubated for 48 h. The antioxidant capacity increased after fermentation. FL had the highest DPPH inhibition (81.32±3.45; p ≤ 0.05) compared to SF and unfermented (UF) black grape juice (75.17±1.47 and 65.63±1.02%, respectively). The pH values decreased during fermentation for both, SF and FL. M also had highest inhibition of α-glucosidase (80.15±3.23) and α-amylase (39.95±0.88). Fermentation of black grape juice using monoculture of L. plantarum has higher antioxidant activities and enzyme inhibitor effect than spontaneous and unfermented black grape juices (p ≤ 0.05). Thus fermented black grape juice may have the potential to serve as enhanced functional juice with anti-diabetic properties.

  7. Silver Nanocomposite Biosynthesis: Antibacterial Activity against Multidrug-Resistant Strains of Pseudomonas aeruginosa and Acinetobacter baumannii

    Directory of Open Access Journals (Sweden)

    Klebson Silva Santos

    2016-09-01

    Full Text Available Bacterial resistance is an emerging public health issue that is disseminated worldwide. Silver nanocomposite can be an alternative strategy to avoid Gram-positive and Gram-negative bacteria growth, including multidrug-resistant strains. In the present study a silver nanocomposite was synthesized, using a new green chemistry process, by the addition of silver nitrate (1.10−3 mol·L−1 into a fermentative medium of Xanthomonas spp. to produce a xanthan gum polymer. Transmission electron microscopy (TEM was used to evaluate the shape and size of the silver nanoparticles obtained. The silver ions in the nanocomposite were quantified by flame atomic absorption spectrometry (FAAS. The antibacterial activity of the nanomaterial against Escherichia coli (ATCC 22652, Enterococcus faecalis (ATCC 29282, Pseudomonas aeruginosa (ATCC 27853 and Staphylococcus aureus (ATCC 25923 was carried out using 500 mg of silver nanocomposite. Pseudomonas aeruginosa and Acinetobacter baumannii multidrug-resistant strains, isolated from hospitalized patients were also included in the study. The biosynthesized silver nanocomposite showed spherical nanoparticles with sizes smaller than 10 nm; 1 g of nanocomposite contained 49.24 µg of silver. Multidrug-resistant strains of Pseudomonas aeruginosa and Acinetobacter baumannii, and the other Gram-positive and Gram-negative bacteria tested, were sensitive to the silver nanocomposite (10–12.9 mm of inhibition zone. The biosynthesized silver nanocomposite seems to be a promising antibacterial agent for different applications, namely biomedical devices or topical wound coatings.

  8. Bioaugmentation with GFP-Tagged Pseudomonas migulae AN-1 in Aniline-Contaminated Aquifer Microcosms: Cellular Responses, Survival and Effect on Indigenous Bacterial Community.

    Science.gov (United States)

    Zhao, Yongsheng; Qu, Dan; Zhou, Rui; Ma, Yunge; Wang, Hao; Ren, Hejun

    2016-05-28

    The recently isolated aniline-degrading bacterium Pseudomonas migulae AN-1 was tagged with green fluorescent protein (GFP) to investigate its bioaugmentation potential against anilinecontaminated groundwater through microcosm experiments. The survival and cellular response of GFP-tagged AN-1 introduced in a lab-scale aquifer corresponded directly with aniline consumption. During the process, the GFP-tagged AN-1 biomass increased from 7.52 × 10⁵ cells/ml to 128 × 10⁵ cells/ml and the degradation rate of aniline was 6.04 mg/l/h. GFP-tagged AN-1 was moderately hydrophobic (41.74%-47.69%) when treated with 20- 100 mg/l aniline and exhibited relatively strong hydrophobicity (55.25%-65.78%) when the concentration of aniline was ≥100 mg/l. The membrane permeability of AN-1 increased followed by a rise in aniline below 100 mg/l and was invariable with aniline above 100 mg/l. Pyrosequencing analysis showed that the relative abundance of Proteobacteria (accounted for 99.22% in the non-bioaugmentation samples) changed to 89.23% after bioaugmentation with GFP-tagged AN-1. Actinobacteria increased from 0.29% to 2.01%, whereas the abundance of Firmicutes barely changed. These combined findings demonstrate the feasibility of removing aniline in aquifers by introducing the strain AN-1 and provide valuable information on the changes in the diversity of dominant populations during bioaugmentation.

  9. Sodium houttuyfonate, a potential phytoanticipin derivative of antibacterial agent, inhibits bacterial attachment and pyocyanine secretion of Pseudomonas aeruginosa by attenuating flagella-mediated swimming motility.

    Science.gov (United States)

    Shao, Jing; Cheng, Huijuan; Wang, Changzhong; Wu, Daqiang; Zhu, Xiaoli; Zhu, Lingling; Sun, Zhenxin

    2013-12-01

    Pseudomonas aeruginosa is a well-known clinical pathogen for its recalcitrant infection caused by biofilm formation which are initiated by flagella-mediated attachment. Sodium houttuyfonate (SH) is a natural phytoanticipin derivative of houttuynin and has anti-pathogenic effect on P. aeruginosa biofilm formation. In this paper, when using 1/2 × MIC SH, the diameter of P. aeruginosa swimming motility was sharply shortened to 36 % in 24 h incubation, and the fold changes of fliC required for swimming motility was 0.36 in 24 h cultivation, the adherence inhibition accounted for about 46 %, and the pyocyanin production decreased to 47 % after 1-day treatment and 56 % after 3-day treatment with obvious visual changes from dark green to light green, compared with the negative control. With the help of mass spectra and scanning electronic microscope, 1/2 × MIC SH was further testified to be enough to eradicate flagella and inhibit pyocyanin secretion of P. aeruginosa. The results do not only re-affirm the close interplay of attachment and virulence (i.e. swimming motility and pyocyanin), but also unravel the potential mechanism of SH on anti-biofilm of P. aeruginosa.

  10. New quinoproteins in oxidative fermentation.

    Science.gov (United States)

    Adachi, O; Moonmangmee, D; Shinagawa, E; Toyama, H; Yamada, M; Matsushita, K

    2003-04-11

    Several quinoproteins have been newly indicated in acetic acid bacteria, all of which can be applied to fermentative or enzymatic production of useful materials by means of oxidative fermentation. (1) D-Arabitol dehydrogenase from Gluconobacter suboxydans IFO 3257 was purified from the bacterial membrane and found to be a versatile enzyme for oxidation of various substrates to the corresponding oxidation products. It is worthy of notice that the enzyme catalyzes D-gluconate oxidation to 5-keto-D-gluconate, whereas 2-keto-D-gluconate is produced by a flavoprotein D-gluconate dehydrogenase. (2) Membrane-bound cyclic alcohol dehydrogenase was solubilized and purified for the first time from Gluconobacter frateurii CHM 9. When compared with the cytosolic NAD-dependent cyclic alcohol dehydrogenase crystallized from the same strain, the reaction rate in cyclic alcohol oxidation by the membrane enzyme was 100 times stronger than the cytosolic NAD-dependent enzyme. The NAD-dependent enzyme makes no contribution to cyclic alcohol oxidation but contributes to the reduction of cyclic ketones to cyclic alcohols. (3) Meso-erythritol dehydrogenase has been purified from the membrane fraction of G. frateurii CHM 43. The typical properties of quinoproteins were indicated in many respects with the enzyme. It was found that the enzyme, growing cells and also the resting cells of the organism are very effective in producing L-erythrulose. Dihydroxyacetone can be replaced by L-erythrulose for cosmetics for those who are sensitive to dihydroxyacetone. (4) Two different membrane-bound D-sorbitol dehydrogenases were indicated in acetic acid bacteria. One enzyme contributing to L-sorbose production has been identified to be a quinoprotein, while another FAD-containing D-sorbitol dehydrogenase catalyzes D-sorbitol oxidation to D-fructose. D-Fructose production by the oxidative fermentation would be possible by the latter enzyme and it is superior to the well-established D-glucose isomerase

  11. Screening for resistance against Pseudomonas syringae in rice-FOX Arabidopsis lines identified a putative receptor-like cytoplasmic kinase gene that confers resistance to major bacterial and fungal pathogens in Arabidopsis and rice.

    Science.gov (United States)

    Dubouzet, Joseph G; Maeda, Satoru; Sugano, Shoji; Ohtake, Miki; Hayashi, Nagao; Ichikawa, Takanari; Kondou, Youichi; Kuroda, Hirofumi; Horii, Yoko; Matsui, Minami; Oda, Kenji; Hirochika, Hirohiko; Takatsuji, Hiroshi; Mori, Masaki

    2011-05-01

    Approximately 20,000 of the rice-FOX Arabidopsis transgenic lines, which overexpress 13,000 rice full-length cDNAs at random in Arabidopsis, were screened for bacterial disease resistance by dip inoculation with Pseudomonas syringae pv. tomato DC3000 (Pst DC3000). The identities of the overexpressed genes were determined in 72 lines that showed consistent resistance after three independent screens. Pst DC3000 resistance was verified for 19 genes by characterizing other independent Arabidopsis lines for the same genes in the original rice-FOX hunting population or obtained by reintroducing the genes into ecotype Columbia by floral dip transformation. Thirteen lines of these 72 selections were also resistant to the fungal pathogen Colletotrichum higginsianum. Eight genes that conferred resistance to Pst DC3000 in Arabidopsis have been introduced into rice for overexpression, and transformants were evaluated for resistance to the rice bacterial pathogen, Xanthomonas oryzae pv. oryzae. One of the transgenic rice lines was highly resistant to Xanthomonas oryzae pv. oryzae. Interestingly, this line also showed remarkably high resistance to Magnaporthe grisea, the fungal pathogen causing rice blast, which is the most devastating rice disease in many countries. The causal rice gene, encoding a putative receptor-like cytoplasmic kinase, was therefore designated as BROAD-SPECTRUM RESISTANCE 1. Our results demonstrate the utility of the rice-FOX Arabidopsis lines as a tool for the identification of genes involved in plant defence and suggest the presence of a defence mechanism common between monocots and dicots. © 2010 The Authors. Plant Biotechnology Journal © 2010 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd.

  12. Azithromycin-Ciprofloxacin-Impregnated Urinary Catheters Avert Bacterial Colonization, Biofilm Formation, and Inflammation in a Murine Model of Foreign-Body-Associated Urinary Tract Infections Caused by Pseudomonas aeruginosa.

    Science.gov (United States)

    Saini, Hina; Vadekeetil, Anitha; Chhibber, Sanjay; Harjai, Kusum

    2017-03-01

    Pseudomonas aeruginosa is a multifaceted pathogen causing a variety of biofilm-mediated infections, including catheter-associated urinary tract infections (CAUTIs). The high prevalence of CAUTIs in hospitals, their clinical manifestations, such as urethritis, cystitis, pyelonephritis, meningitis, urosepsis, and death, and the associated economic challenges underscore the need for management of these infections. Biomaterial modification of urinary catheters with two drugs seems an interesting approach to combat CAUTIs by inhibiting biofilm. Previously, we demonstrated the in vitro efficacy of urinary catheters impregnated with azithromycin (AZM) and ciprofloxacin (CIP) against P. aeruginosa Here, we report how these coated catheters impact the course of CAUTI induced by P. aeruginosa in a murine model. CAUTI was established in female LACA mice with uncoated or AZM-CIP-coated silicone implants in the bladder, followed by transurethral inoculation of 10 8 CFU/ml of biofilm cells of P. aeruginosa PAO1. AZM-CIP-coated implants (i) prevented biofilm formation on the implant's surface ( P ≤ 0.01), (ii) restricted bacterial colonization in the bladder and kidney ( P catheters, which may possibly be a key to success in preventing CAUTIs. Copyright © 2017 American Society for Microbiology.

  13. Ethanol fermentation

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    The inulin of chicory slices was hydrolyzed enzymically and fermented to ethanol. Maximum ethanol yield was achieved with fermentation combined with saccharification, using cellulase and inulinase for saccharification. The fermenting organism was Saccharomyces cerevisiae. Kluyveromyces fragilis, containing endogenous inulinase, was also used, but with lower yield.

  14. Biosynthesis and regulation of cyclic lipopeptides in Pseudomonas fluorescens

    NARCIS (Netherlands)

    Bruijn, de I.

    2009-01-01

    Cyclic lipopeptides (CLPs) are surfactant and antibiotic metabolites produced by a variety of bacterial genera. For the genus Pseudomonas, many structurally different CLPs have been identified. CLPs play an important role in surface motility of Pseudomonas strains, but also in virulence and

  15. Pseudomonas Exotoxin A: optimized by evolution for effective killing

    Directory of Open Access Journals (Sweden)

    Marta eMichalska

    2015-09-01

    Full Text Available Pseudomonas Exotoxin A (PE is the most toxic virulence factor of the pathogenic bacterium Pseudomonas aeruginosa. This review describes current knowledge about the intoxication pathways of PE. Moreover, PE represents a remarkable example for pathoadaptive evolution, how bacterial molecules have been structurally and functionally optimized under evolutionary pressure to effectively impair and kill their host cells.

  16. The stack: a new bacterial structure analyzed in the Antarctic bacterium Pseudomonas deceptionensis M1(T by transmission electron microscopy and tomography.

    Directory of Open Access Journals (Sweden)

    Lidia Delgado

    Full Text Available In recent years, improvements in transmission electron microscopy (TEM techniques and the use of tomography have provided a more accurate view of the complexity of the ultrastructure of prokaryotic cells. Cryoimmobilization of specimens by rapid cooling followed by freeze substitution (FS and sectioning, freeze fracture (FF and observation of replica, or cryoelectron microscopy of vitreous sections (CEMOVIS now allow visualization of biological samples close to their native state, enabling us to refine our knowledge of already known bacterial structures and to discover new ones. Application of these techniques to the new Antarctic cold-adapted bacterium Pseudomonasdeceptionensis M1(T has demonstrated the existence of a previously undescribed cytoplasmic structure that does not correspond to known bacterial inclusion bodies or membranous formations. This structure, which we term a "stack", was mainly visualized in slow growing cultures of P. deceptionensis M1(T and can be described as a set of stacked membranous discs usually arranged perpendicularly to the cell membrane, but not continuous with it, and found in variable number in different locations within the cell. Regardless of their position, stacks were mostly observed very close to DNA fibers. Stacks are not exclusive to P. deceptionensis M1(T and were also visualized in slow-growing cultures of other bacteria. This new structure deserves further study using cryoelectron tomography to refine its configuration and to establish whether its function could be related to chromosome dynamics.

  17. A lactose fermentation product produced by Lactococcus lactis subsp. lactis, acetate, inhibits the motility of flagellated pathogenic bacteria.

    Science.gov (United States)

    Nakamura, Shuichi; Morimoto, Yusuke V; Kudo, Seishi

    2015-04-01

    Many strains of lactic acid bacteria have been used for the production of probiotics. Some metabolites produced by lactic acid bacteria impair the motilities of pathogenic bacteria. Because bacterial motility is strongly associated with virulence, the metabolic activities of lactic acid bacteria are effective for suppressing bacterial infections. Here we show that lactose fermentation by Lactococcus lactis subsp. lactis inhibits the motility of Salmonella enterica serovar Typhimurium. A single-cell tracking and rotation assay for a single flagellum showed that the swimming behaviour of Salmonella was severely but transiently impaired through disruption of flagellar rotation on exposure to media cultivated with Lac. lactis. Using a pH-sensitive fluorescent protein, we observed that the intracellular pH of Salmonella was decreased because of some fermentation products of Lac. lactis. We identified acetate as the lactose fermentation product of Lac. lactis triggering the paralysis of Salmonella flagella. The motilities of Pseudomonas, Vibrio and Leptospira strains were also severely disrupted by lactose utilization by Lac. lactis. These results highlight the potential use of Lac. lactis for preventing infections by multiple bacterial species. © 2015 The Authors.

  18. Sequencing and characterization of Pseudomonas aeruginosa phage JG004

    National Research Council Canada - National Science Library

    Garbe, Julia; Bunk, Boyke; Rohde, Manfred; Schobert, Max

    2011-01-01

    .... Pseudomonas aeruginosa. For an effective use of bacteriophages as antimicrobial agents, it is important to understand phage biology but also genes of the bacterial host essential for phage infection...

  19. New strategies for genetic engineering Pseudomonas syringae using recombination

    Science.gov (United States)

    Here we report that DNA oligonucleotides (oligos) introduced directly into bacteria by electroporation can recombine with the bacterial chromosome. This phenomenon was identified in Pseudomonas syringae and we subsequently found that Escherichia coli, Salmonella typhimurium and Shigella flexneri are...

  20. SOLID-STATE FERMENTATIVE PRODUCTION AND BIOACTIVITY OF FUNGAL CHITOSAN

    Directory of Open Access Journals (Sweden)

    Barry Aigbodion Omogbai

    2013-10-01

    Full Text Available Chitosan production was investigated using a laboratory-scale solid substrate fermentation (SSF technique with four species of fungi: Penicillium expansum, Aspergillus niger, Rhizopus oryzae and Fusarium moniliforme.The peak growth for the organisms was after 16 days. Aspergillus niger had the highest growth with a maximal dry cell biomass of 15.8g/kg after 16 days cultivation on corn straw under solid substrate fermentation. This was closely followed by Rhizopus oryzae (14.6g/kg, Penicillium expansum (13.8g/kg and Fusarium moniliforme (10.6g/kg respectively. The fungus Rhizopus oryzae had the highest chitosan production with a maximum of 8.57g/kg in 16 days under solid substrate fermentation (SSF with a medium containing corn straw. Aspergillus niger showed a modest chitosan yield of 6.8g/kg. Penicillium expansum and Fusarium moniliforme had low chitosan yields of 4.31g/kg and 3.1g/kg respectively. The degree of deacetylation of fungal chitosans ranged between 75.3-91.5% with a viscosity of 3.6-7.2 centipoises (Cp.Chitosan extracted from Rhizopus oryzae was found to have antibacterial activity on some bacterial isolates. At a concentration of 50mg/L, Rhizopus oryzae chitosan paralleled crab chitosan in susceptibility testing against some food-borne bacterial pathogens. Escherichia coli, Salmonella typhi, Pseudomonas aeruginosa and Bacillus subtilis showed inhibition rates of 83.2%, 67.9%, 63.8% and 62.4% respectively in response to 50mg/l Rhizopus oryzae chitosan in 24 h. The rate of inhibition (% increased with increase in chitosan concentration.

  1. Panax ginseng has anti-infective activity against opportunistic pathogen Pseudomonas aeruginosa by inhibiting quorum sensing, a bacterial communication process critical for establishing infection

    DEFF Research Database (Denmark)

    Song, Z; Kong, K F; Wu, H

    2010-01-01

    immune systems and cystic fibrosis. The QS systems of P. aeruginosa use N-acylated homoserine lactone (AHL) as signal molecules. Previously we have demonstrated that Panax ginseng treatment allowed the animals with P. aeruginosa pneumonia to effectively clear the bacterial infection. We postulated...... that the ability to impact the outcome of infections is partly due to ginseng having direct effect on the production of P. aeruginosa virulence factors. The study explores the effect of ginseng on alginate, protease and AHL production. The effect of ginseng extracts on growth and expression of QS......-controlled virulence factors on the prototypic P. aeruginosa PAO1 and its isogenic mucoid variant (PAOmucA22) was determined. Ginseng did not inhibit the growth of the bacteria, enhanced the extracellular protein production and stimulated the production of alginate. However, ginseng suppressed the production of Las...

  2. Consistent 1,3-propanediol production from glycerol in mixed culture fermentation over a wide range of pH

    National Research Council Canada - National Science Library

    Moscoviz, Roman; Trably, Eric; Bernet, Nicolas

    2016-01-01

    ...) in fermentation processes. The aim of this study was to investigate the effect of initial pH on a batch mixed culture fermentation of glycerol, considering both the bacterial community composition and the fermentation patterns...

  3. Quantification of viable bacterial starter cultures of Virgibacillus sp. and Tetragenococcus halophilus in fish sauce fermentation by real-time quantitative PCR.

    Science.gov (United States)

    Udomsil, Natteewan; Chen, Shu; Rodtong, Sureelak; Yongsawatdigul, Jirawat

    2016-08-01

    Real-time quantitative polymerase chain reaction (qPCR) methods were developed for the quantification of Virgibacillus sp. SK37 and Tetragenococcus halophilus MS33, which were added as starter cultures in fish sauce fermentation. The PCR assays were coupled with propidium monoazide (PMA) treatment of samples to selectively quantify viable cells and integrated with exogenous recombinant Escherichia coli cells to control variabilities in analysis procedures. The qPCR methods showed species-specificity for both Virgibacillus halodenitrificans and T. halophilus as evaluated using 6 reference strains and 28 strains of bacteria isolated from fish sauce fermentation. The qPCR efficiencies were 101.1% for V. halodenitrificans and 90.2% for T. halophilus. The quantification limits of the assays were 10(3) CFU/mL and 10(2) CFU/mL in fish sauce samples with linear correlations over 4 Logs for V. halodenitrificans and T. halophilus, respectively. The matrix effect was not observed when evaluated using fish sauce samples fermented for 1-6 months. The developed PMA-qPCR methods were successfully applied to monitor changes of Virgibacillus sp. SK37 and T. halophilus MS33 in a mackerel fish sauce fermentation model where culture-dependent techniques failed to quantify the starter cultures. The results demonstrated the usability of the methods as practical tools for monitoring the starter cultures in fish sauce fermentation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Plant growth promotion by Pseudomonas fluorescens

    NARCIS (Netherlands)

    Cheng, X.

    2016-01-01

    Pseudomonas fluorescens is a Gram-negative rod shaped bacterium that has a versatile metabolism and is widely spread in soil and water. P. fluorescens strain SBW25 (Pf.SBW25) is a well-known model strain to study bacterial evolution, plant colonization and biocontrol of plant diseases. It produces

  5. Behavioral response of resistant and sensitive Pseudomonas ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-07-18

    Jul 18, 2008 ... Key words: Pseudomonas aeruginosa, cadmium stress, heavy metal resistance. INTRODUCTION. The release of .... plasmids located in the bacterial strains isolated from agricultural and industrial soils ..... esteraromaticum S51 with other strains of non-flocculating sludge bacteria. IWA's Water Environ.

  6. Pseudomonas aeruginosa in Healthcare Settings

    Science.gov (United States)

    ... Sepsis Sharps Safety - CDC Transplant Safety Vaccine Safety Pseudomonas aeruginosa in Healthcare Settings Recommend on Facebook Tweet Share ... aeruginosa . Pseudomonas aeruginosa What types of infections does Pseudomonas aeruginosa cause? Serious Pseudomonas infections usually occur in people ...

  7. Bacterial Two-Hybrid Analysis of Interactions between Region 4 of the ς70 Subunit of RNA Polymerase and the Transcriptional Regulators Rsd from Escherichia coli and AlgQ from Pseudomonas aeruginosa

    Science.gov (United States)

    Dove, Simon L.; Hochschild, Ann

    2001-01-01

    A number of transcriptional regulators mediate their effects through direct contact with the ς70 subunit of Escherichia coli RNA polymerase (RNAP). In particular, several regulators have been shown to contact a C-terminal portion of ς70 that harbors conserved region 4. This region of ς contains a putative helix-turn-helix DNA-binding motif that contacts the −35 element of ς70-dependent promoters directly. Here we report the use of a recently developed bacterial two-hybrid system to study the interaction between the putative anti-ς factor Rsd and the ς70 subunit of E. coli RNAP. Using this system, we found that Rsd can interact with an 86-amino-acid C-terminal fragment of ς70 and also that amino acid substitution R596H, within region 4 of ς70, weakens this interaction. We demonstrated the specificity of this effect by showing that substitution R596H does not weaken the interaction between ς and two other regulators shown previously to contact region 4 of ς70. We also demonstrated that AlgQ, a homolog of Rsd that positively regulates virulence gene expression in Pseudomonas aeruginosa, can contact the C-terminal region of the ς70 subunit of RNAP from this organism. We found that amino acid substitution R600H in ς70 from P. aeruginosa, corresponding to the R596H substitution in E. coli ς70, specifically weakens the interaction between AlgQ and ς70. Taken together, our findings suggest that Rsd and AlgQ contact similar surfaces of RNAP present in region 4 of ς70 and probably regulate gene expression through this contact. PMID:11591686

  8. Bacterial two-hybrid analysis of interactions between region 4 of the sigma(70) subunit of RNA polymerase and the transcriptional regulators Rsd from Escherichia coli and AlgQ from Pseudomonas aeruginosa.

    Science.gov (United States)

    Dove, S L; Hochschild, A

    2001-11-01

    A number of transcriptional regulators mediate their effects through direct contact with the sigma(70) subunit of Escherichia coli RNA polymerase (RNAP). In particular, several regulators have been shown to contact a C-terminal portion of sigma(70) that harbors conserved region 4. This region of sigma contains a putative helix-turn-helix DNA-binding motif that contacts the -35 element of sigma(70)-dependent promoters directly. Here we report the use of a recently developed bacterial two-hybrid system to study the interaction between the putative anti-sigma factor Rsd and the sigma(70) subunit of E. coli RNAP. Using this system, we found that Rsd can interact with an 86-amino-acid C-terminal fragment of sigma(70) and also that amino acid substitution R596H, within region 4 of sigma(70), weakens this interaction. We demonstrated the specificity of this effect by showing that substitution R596H does not weaken the interaction between sigma and two other regulators shown previously to contact region 4 of sigma(70). We also demonstrated that AlgQ, a homolog of Rsd that positively regulates virulence gene expression in Pseudomonas aeruginosa, can contact the C-terminal region of the sigma(70) subunit of RNAP from this organism. We found that amino acid substitution R600H in sigma(70) from P. aeruginosa, corresponding to the R596H substitution in E. coli sigma(70), specifically weakens the interaction between AlgQ and sigma(70). Taken together, our findings suggest that Rsd and AlgQ contact similar surfaces of RNAP present in region 4 of sigma(70) and probably regulate gene expression through this contact.

  9. Azithromycin-Ciprofloxacin-Impregnated Urinary Catheters Avert Bacterial Colonization, Biofilm Formation, and Inflammation in a Murine Model of Foreign-Body-Associated Urinary Tract Infections Caused by Pseudomonas aeruginosa

    Science.gov (United States)

    Saini, Hina; Vadekeetil, Anitha

    2016-01-01

    ABSTRACT Pseudomonas aeruginosa is a multifaceted pathogen causing a variety of biofilm-mediated infections, including catheter-associated urinary tract infections (CAUTIs). The high prevalence of CAUTIs in hospitals, their clinical manifestations, such as urethritis, cystitis, pyelonephritis, meningitis, urosepsis, and death, and the associated economic challenges underscore the need for management of these infections. Biomaterial modification of urinary catheters with two drugs seems an interesting approach to combat CAUTIs by inhibiting biofilm. Previously, we demonstrated the in vitro efficacy of urinary catheters impregnated with azithromycin (AZM) and ciprofloxacin (CIP) against P. aeruginosa. Here, we report how these coated catheters impact the course of CAUTI induced by P. aeruginosa in a murine model. CAUTI was established in female LACA mice with uncoated or AZM-CIP-coated silicone implants in the bladder, followed by transurethral inoculation of 108 CFU/ml of biofilm cells of P. aeruginosa PAO1. AZM-CIP-coated implants (i) prevented biofilm formation on the implant's surface (P ≤ 0.01), (ii) restricted bacterial colonization in the bladder and kidney (P < 0.0001), (iii) averted bacteriuria (P < 0.0001), and (iv) exhibited no major histopathological changes for 28 days in comparison to uncoated implants, which showed persistent CAUTI. Antibiotic implants also overcame implant-mediated inflammation, as characterized by trivial levels of inflammatory markers such as malondialdehyde (P < 0.001), myeloperoxidase (P < 0.05), reactive oxygen species (P ≤ 0.001), and reactive nitrogen intermediates (P < 0.01) in comparison to those in uncoated implants. Further, AZM-CIP-coated implants showed immunomodulation by manipulating the release of inflammatory cytokines interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and IL-10 to the benefit of the host. Overall, the study demonstrates long-term in vivo effectiveness of AZM-CIP-impregnated catheters

  10. Origin of the Outbreak in France of Pseudomonas syringae pv. actinidiae Biovar 3, the Causal Agent of Bacterial Canker of Kiwifruit, Revealed by a Multilocus Variable-Number Tandem-Repeat Analysis.

    Science.gov (United States)

    Cunty, A; Cesbron, S; Poliakoff, F; Jacques, M-A; Manceau, C

    2015-10-01

    The first outbreaks of bacterial canker of kiwifruit caused by Pseudomonas syringae pv. actinidiae biovar 3 were detected in France in 2010. P. syringae pv. actinidiae causes leaf spots, dieback, and canker that sometimes lead to the death of the vine. P. syringae pv. actinidifoliorum, which is pathogenic on kiwi as well, causes only leaf spots. In order to conduct an epidemiological study to track the spread of the epidemics of these two pathogens in France, we developed a multilocus variable-number tandem-repeat (VNTR) analysis (MLVA). MLVA was conducted on 340 strains of P. syringae pv. actinidiae biovar 3 isolated in Chile, China, France, Italy, and New Zealand and on 39 strains of P. syringae pv. actinidifoliorum isolated in Australia, France, and New Zealand. Eleven polymorphic VNTR loci were identified in the genomes of P. syringae pv. actinidiae biovar 3 ICMP 18744 and of P. syringae pv. actinidifoliorum ICMP 18807. MLVA enabled the structuring of P. syringae pv. actinidiae biovar 3 and P. syringae pv. actinidifoliorum strains in 55 and 16 haplotypes, respectively. MLVA and discriminant analysis of principal components revealed that strains isolated in Chile, China, and New Zealand are genetically distinct from P. syringae pv. actinidiae strains isolated in France and in Italy, which appear to be closely related at the genetic level. In contrast, no structuring was observed for P. syringae pv. actinidifoliorum. We developed an MLVA scheme to explore the diversity within P. syringae pv. actinidiae biovar 3 and to trace the dispersal routes of epidemic P. syringae pv. actinidiae biovar 3 in Europe. We suggest using this MLVA scheme to trace the dispersal routes of P. syringae pv. actinidiae at a global level. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  11. Analysis of Substrate Access to Active Sites in Bacterial Multicomponent Monooxygenase Hydroxylases: X-ray Crystal Structure of Xenon-Pressurized Phenol Hydroxylase from Pseudomonas sp. OX1†,‡

    Science.gov (United States)

    McCormick, Michael S.; Lippard, Stephen J.

    2011-01-01

    In all structurally characterized bacterial multicomponent monooxygenase (BMM) hydroxylase proteins, a series of hydrophobic cavities in the α-subunit trace a conserved path from the protein exterior to the carboxylate-bridged diiron active site. The present study examines these cavities as a potential route for dioxygen transport to the active site by crystallographic characterization of a xenon-pressurized sample of the hydroxylase component of phenol hydroxylase from Pseudomonas sp. OX1. Computational analyses of the hydrophobic cavities in the hydroxylase α-subunits of phenol hydroxylase (PHH), toluene/o-xylene monooxygenase (ToMOH), and soluble methane monooxygenase (sMMOH) are also presented. The results, together with previous findings from crystallographic studies of xenon-pressurized sMMO hydroxylase, clearly identify the propensity for these cavities to bind hydrophobic gas molecules in the protein interior. This proposed functional role is supported by recent stopped flow kinetic studies of ToMOH variants (Song, et al., 2011). In addition to information about the Xe sites, the structure determination revealed significantly reduced regulatory protein binding to the hydroxylase in comparison to the previously reported structure of PHH, as well as the presence of a newly identified metal binding site in the α-subunit that adopts a linear coordination environment consistent with Cu(I), and a glycerol molecule bound to Fe1 in a fashion that is unique among hydrocarbon-diiron site adducts reported to date in BMM hydroxylase structures. Finally, a comparative analysis of the α-subunit structures of MMOH, ToMOH, and PHH details proposed routes for the other three BMM substrates, the hydrocarbon, electrons, and protons, comprising cavities, channels, hydrogen-bonding networks, and pores in the structures of their α-subunits. PMID:22136180

  12. Bactérias endofíticas no controle e inibição in vitro de Pseudomonas syringae pv tomato, agente da pinta bacteriana do tomateiro Control with endophytic bacteria and in vitro inhibition of Pseudomonas syringae pv tomato, agent of bacterial speck of tomato

    Directory of Open Access Journals (Sweden)

    Juliana Resende Campos Silva

    2008-08-01

    Full Text Available Para avaliar o potencial de 53 isolados de bactérias endofíticas no controle da pinta bacteriana do tomateiro (Lycopersicum esculentum Mill., realizaram-se seleções massais em casa-de-vegetação e a seguir foi avaliado, in vitro, o antagonismo desses isolados sobre a bactéria desafiante Pseudomonas syringae pv. tomato (Pst. A inoculação das bactérias endofíticas foi feita por microbiolização das sementes de tomate cv. Santa Clara e da desafiante (Pst por pulverização. Aos 7, 14 e 21 dias após a inoculação da Pst, foram realizadas as avaliações da severidade da pinta bacteriana, bem como da altura das plantas. As espécies e os isolados bacterianos mais eficazes na redução da severidade da pinta bacteriana foram: Acinetobacter johnsonii (isolado 10, Bacillus pumilus (isolados 3, 12, 20, 39, 51, Paenibacillus macerans (isolados 37 e 47, PIM 11, Bacillus sphaericus (isolado 45, B. amyloliquefaciens (isolado 50, TOM 2, TOM 24 e Staphylococcus aureus (isolado 18. Mais de 50% dos isolados eficazes na redução da severidade foram da espécie Bacillus pumilus. Das espécies endofíticas mais eficazes na redução da severidade da pinta bacteriana, Bacillus pumilus e B. amyloliquefaciens inibiram também o crescimento da Pst in vitro.Vários dos isolados promoveram também o crescimento das plantas.To asses the potential of fifty three isolates of endophytic bacteria on the control of Pseudomonas syringae pv. tomato (Pst in tomato (Lycopersicum esculentum Mill., several screening were done in greenhouse followed by in vitro studies on antagonism of those isolates to Pst. The inoculation of endophytic bacteria was done by microbiolization of tomato cv Santa Clara seeds. The challenging bacterium (Pst inoculation was done by spraying. At 7, 14 and 21 days after Pst inoculation the assessment of bacterial speck severity was done, and height of plants was also measured. The most efficient endophytic species and isolates in reducing

  13. Microbial Cellulose: Fermentative Production and Applications

    OpenAIRE

    Chawla, Prashant R.; Ishwar B. Bajaj; Survase, Shrikant A.; Rekha S. Singhal

    2009-01-01

    Bacterial cellulose, an exopolysaccharide produced by some bacteria, has unique structural and mechanical properties and is highly pure as compared to plant cellulose. This article presents a critical review of the available information on the bacterial cellulose with special emphasis on its fermentative production and applications. Information on the biosynthetic pathway of bacterial cellulose, enzymes and precursors involved in bacterial cellulose synthesis has been specified. Characteristi...

  14. Bacterial diversity of the Colombian fermented milk "Suero Costeño" assessed by culturing and high-throughput sequencing and DGGE analysis of 16S rRNA gene amplicons.

    Science.gov (United States)

    Motato, Karina Edith; Milani, Christian; Ventura, Marco; Valencia, Francia Elena; Ruas-Madiedo, Patricia; Delgado, Susana

    2017-12-01

    "Suero Costeño" (SC) is a traditional soured cream elaborated from raw milk in the Northern-Caribbean coast of Colombia. The natural microbiota that characterizes this popular Colombian fermented milk is unknown, although several culturing studies have previously been attempted. In this work, the microbiota associated with SC from three manufacturers in two regions, "Planeta Rica" (Córdoba) and "Caucasia" (Antioquia), was analysed by means of culturing methods in combination with high-throughput sequencing and DGGE analysis of 16S rRNA gene amplicons. The bacterial ecosystem of SC samples was revealed to be composed of lactic acid bacteria belonging to the Streptococcaceae and Lactobacillaceae families; the proportions and genera varying among manufacturers and region of elaboration. Members of the Lactobacillus acidophilus group, Lactocococcus lactis, Streptococcus infantarius and Streptococcus salivarius characterized this artisanal product. In comparison with culturing, the use of molecular in deep culture-independent techniques provides a more realistic picture of the overall bacterial communities residing in SC. Besides the descriptive purpose, these approaches will facilitate a rational strategy to follow (culture media and growing conditions) for the isolation of indigenous strains that allow standardization in the manufacture of SC. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. The influence of complex fermentation broth on denitrification of saline sewage in constructed wetlands by heterotrophic nitrifying/aerobic denitrifying bacterial communities.

    Science.gov (United States)

    Fu, Guiping; Yu, Tianyu; Huangshen, Linkun; Han, Jingyi

    2017-11-21

    An experimental vertical-flow constructed wetland (CW) was tested to treat salt-containing sewage. CW clogging deposits and withered Pontederia cordata L. were collected into a complex fermentation broth to serve as the carbon source and its effects on the denitrification capacity and microbial composition of the CW were examined. Addition of the complex fermentation broth into the CW influent (1.8% salinity) led to high removal efficiencies of NH 4 + -N > 99.82 ± 0.00% and TN > 90.39 ± 0.05%. Heterotrophic nitrifiers and aerobic denitrifiers were entirely dominant in the middle and upper layers of the CW, where obligate halophilic, aerobic denitrifiers Zobellella occurred. The CW successfully cultivated and enriched heterotrophic nitrifying-aerobic denitrifying bacteria, overcoming the effects of salinity and insufficient organic carbon sources on the denitrification capacity of CW. This type of complex carbon sources can also facilitate the utilization of waste resources, such as CW clogging deposits and withered wetland plants. Copyright © 2017. Published by Elsevier Ltd.

  16. Improved fermentation performance in an expanded ectopic fermentation system inoculated with thermophilic bacteria.

    Science.gov (United States)

    Guo, Hui; Zhu, Changxiong; Geng, Bing; Liu, Xue; Ye, Jing; Tian, Yunlong; Peng, Xiawei

    2015-12-01

    Previous research showed that ectopic fermentation system (EFS) inoculated with thermophilic bacteria is an excellent alternative for cow wastewater treatment. In this study, the effects of thermophilic bacterial consortium on the efficiency and quality of the fermentation process in EFS were evaluated by measuring physicochemical and environmental factors and the changes in organic matter composition. In parallel, the microbial communities correlated with fermentation performance were identified. Inoculation of EFS with thermophilic bacterial consortium led to higher temperatures, increased wastewater requirements for continuous fermentation, and improved quality of the litters in terms of physicochemical factors, security test, functional group analysis, and bacterial community composition. The relationship between the transformation of organic component and the dominant bacteria species indicated that environmental factors contributed to strain growth, which subsequently promoted the fermentation process. The results highlight the great potential of EFS model for wide application in cow wastewater treatment and re-utilization as bio-fertilizer. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. The Transcriptional Landscape of the Production Organism Pseudomonas putida

    DEFF Research Database (Denmark)

    D'Arrigo, Isotta

    Bacterial cell factories represent a valid alternative to fossil fuel-based production. A promising bacterium that can be optimized as cell factory is Pseudomonas putida. However, its development in bioproduction applications poses some challenges including a clear understanding of the bacterial ...

  18. Toward pectin fermentation by Saccharomyces cerevisiae: Expression of the first two steps of a bacterial pathway for d-galacturonate metabolism.

    NARCIS (Netherlands)

    Huisjes, E.H.; Luttik, M.A.; Almering, M.J.; Bisschops, M.M.; Dang, D.H.; Kleerebezem, M.; Siezen, R.J.; Maris, van A.J.; Pronk, J.T.

    2012-01-01

    Saccharomyces cerevisiae cannot metabolize d-galacturonate, an important monomer of pectin. Use of S. cerevisiae for production of ethanol or other compounds of interest from pectin-rich feedstocks therefore requires introduction of a heterologous pathway for d-galacturonate metabolism. Bacterial

  19. Influence of ensiling, exogenous protease addition, and bacterial inoculation on fermentation profile, nitrogen fractions, and ruminal in vitro starch digestibility in rehydrated and high-moisture corn.

    Science.gov (United States)

    Ferraretto, L F; Fredin, S M; Shaver, R D

    2015-10-01

    Exogenous protease addition may be an option to increase proteolysis of zein proteins and thus starch digestibility in rehydrated and high-moisture corn (HMC) ensiled for short periods. In addition, microbial inoculation may accelerate fermentation and increase acid production and thus increase solubilization of zein proteins. Four experiments were performed to evaluate the effect on fermentation profile, N fractions, and ruminal in vitro starch digestibility (ivSD) of the following: (1) rehydration and ensiling of dry ground corn; (2) exogenous protease addition to rehydrated un-ensiled and ensiled corn; (3) exogenous protease addition or inoculation in rehydrated ensiled corn; and (4) exogenous protease addition or inoculation in HMC. Experiments 1, 2, and 3 were performed with 7 treatments: dry ground corn (DGC); DGC rehydrated to a targeted dry matter content of 70% (REH); REH treated with exogenous protease (REH+); REH ensiled for 30 d (ENS); ENS treated with exogenous protease (ENS+); ENS treated with a microbial inoculant containing Lactobacillus plantarum, Lactobacillus casei, Enterococcus faecium, and Pediococcus sp. (ENSI); and ENS treated with exogenous protease and microbial inoculant (ENSI+). Experiment 1 compared DGC, REH, and ENS with ivSD being greater for ENS (64.9%) than DGC and REH (51.7% on average). Experiment 2 compared REH and ENS without or with exogenous protease addition (REH+ and ENS+, respectively). Ensiling and exogenous protease addition increased ivSD, but exogenous protease addition was more effective in ENS than REH (6.4 vs. 2.6 percentage unit increase). Experiment 3 compared the effects of exogenous protease addition and inoculation in ENS corn (ENS, ENS+, ENSI, and ENSI+). The addition of protease, but not inoculant, increased ivSD. Inoculation reduced pH and acetate, propionate, and ethanol concentrations, and increased lactate and total acid concentrations. In experiment 4, 8 treatments were a combination of HMC noninoculated

  20. Microbial Cellulose: Fermentative Production and Applications

    Directory of Open Access Journals (Sweden)

    Prashant R. Chawla

    2009-01-01

    Full Text Available Bacterial cellulose, an exopolysaccharide produced by some bacteria, has unique structural and mechanical properties and is highly pure as compared to plant cellulose. This article presents a critical review of the available information on the bacterial cellulose with special emphasis on its fermentative production and applications. Information on the biosynthetic pathway of bacterial cellulose, enzymes and precursors involved in bacterial cellulose synthesis has been specified. Characteristics of bacterial cellulose with respect to its structure and physicochemical properties are discussed. Current and potential applications of bacterial cellulose in food, pharmaceutical and other industries are also presented.

  1. Fermentation of sarshir (kaymak) by lactic acid bacteria: antibacterial activity, antioxidant properties, lipid and protein oxidation and fatty acid profile.

    Science.gov (United States)

    Hashemi, Seyed Mohammad Bagher; Mousavi Khaneghah, Amin; Kontominas, Michael G; Eş, Ismail; Sant'Ana, Anderson S; Martinez, Rafael R; Drider, Djamel

    2017-10-01

    The antioxidant and antibacterial activities of fermented sarshir (traditional dairy food), with three probiotic Lactobacillus plantarum strains (LP3, AF1, and LU5), were investigated. The oxidative stability and the lipid profile of non-fermented and fermented sarshir were compared, in addition to radical scavenging activity, as well as peroxide, anisidine and carbonyl values (PV, AnV and CV, respectively). The strong antibacterial activity of fermented sarshir against common pathogenic bacteria, including Gram-negative Escherichia coli O157: H7 ATCC 35150 and Pseudomonas aeruginosa ATCC 27853, as well as Gram-positive Bacillus cereus ATCC 10876 and Staphylococcus aureus ATCC 25923, was established. Among the strains examined, L. plantarum LP3 exhibited the highest radical scavenging activity (53.1 ± 1.8%) and lowest PV (3.0 meq kg-1 ), AnV (1.31 ± 0.06) and CV (1.4 ± 0.08). The pH of sarshir decreased from 6.2 ± 0 to 3.5 ± 0.1 during 14 h of fermentation. Incorporated bacterial cells exhibited notable viability during 10 days of cold storage (4 °C). The fermentation of sarshir by L. plantarum strains, especially LP3, resulted in beneficial changes in radical scavenging activity, as well as PV, AnV and carbonyl values, in addition to a broad spectrum of inhibitory activity against strains of P. aeruginosa, E. coli O157:H7, B. cereus and S. aureus. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  2. Animal Models of Bacterial Keratitis

    Science.gov (United States)

    Marquart, Mary E.

    2011-01-01

    Bacterial keratitis is a disease of the cornea characterized by pain, redness, inflammation, and opacity. Common causes of this disease are Pseudomonas aeruginosa and Staphylococcus aureus. Animal models of keratitis have been used to elucidate both the bacterial factors and the host inflammatory response involved in the disease. Reviewed herein are animal models of bacterial keratitis and some of the key findings in the last several decades. PMID:21274270

  3. Animal Models of Bacterial Keratitis

    Directory of Open Access Journals (Sweden)

    Mary E. Marquart

    2011-01-01

    Full Text Available Bacterial keratitis is a disease of the cornea characterized by pain, redness, inflammation, and opacity. Common causes of this disease are Pseudomonas aeruginosa and Staphylococcus aureus. Animal models of keratitis have been used to elucidate both the bacterial factors and the host inflammatory response involved in the disease. Reviewed herein are animal models of bacterial keratitis and some of the key findings in the last several decades.

  4. Screening bacterial species for antagonistic activities against the ...

    African Journals Online (AJOL)

    In this study, 23 bacteria strains that belong to 19 bacterial species were tested against Sclerotinia sclerotiorum (Lib.) De Bary. In vivo and in vitro testing of bacterial strains showed that Serratia plymuthica strains IK-150 and IK-139, Burkholderia cepacia strain IK-16, Pseudomonas flourocens strain IK-3, Pseudomonas ...

  5. Interfering with bacterial gossip

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Tolker-Nielsen, Tim; Givskov, Michael

    2011-01-01

    defense. Antibiotics exhibit a rather limited effect on biofilms. Furthermore, antibiotics have an ‘inherent obsolescence’ because they select for development of resistance. Bacterial infections with origin in bacterial biofilms have become a serious threat in developed countries. Pseudomonas aeruginosa...... that appropriately target bacteria in their relevant habitat with the aim of mitigating their destructive impact on patients. In this review we describe molecular mechanisms involved in “bacterial gossip” (more scientifically referred to as quorum sensing (QS) and c-di-GMP signaling), virulence, biofilm formation......, resistance and QS inhibition as future antimicrobial targets, in particular those that would work to minimize selection pressures for the development of resistant bacteria....

  6. Microbial community dynamics during fermentation of doenjang-meju, traditional Korean fermented soybean.

    Science.gov (United States)

    Jung, Ji Young; Lee, Se Hee; Jeon, Che Ok

    2014-08-18

    Bacterial and fungal community dynamics, along with viable plate counts and water content, were investigated in the exterior and interior regions of doenjang-meju, traditional Korean fermented soybean, during its fermentation process. Measurement of viable cells showed that the meju molding equipment might be an important source of bacterial cells (mostly Bacillus) during doenjang-meju fermentation, whereas fungi might be mostly derived from the fermentation environment including incubation shelves, air, and rice straws. Community analysis using rRNA-targeted pyrosequencing revealed that Bacillus among bacteria and Mucor among fungi were predominant in both the exterior and interior regions of doenjang-meju during the early fermentation period. Bacteria such as Ignatzschineria, Myroides, Enterococcus, Corynebacterium, and Clostridium and fungi such as Geotrichum, Scopulariopsis, Monascus, Fusarium, and eventually Aspergillus were mainly detected as the fermentation progressed. Bacillus, an aerobic bacterial group, was predominant in the exterior regions during the entire fermentation period, while anaerobic, facultative anaerobic, and microaerobic bacteria including Enterococcus, Lactobacillus, Clostridium, Myroides, and Ignatzschineria were much more abundant in the interior regions. Principal component analysis (PCA) also indicated that the bacterial communities in the exterior and interior regions were clearly differentiated, suggesting that aeration might be an important factor in determining the bacterial communities during doenjang-meju fermentation. However, PCA showed that fungal communities were not separated in the exterior and interior regions and Pearson's correlation coefficients showed that the major fungal taxa had significantly positive (Mucor and Geotrichum) or negative (Aspergillus) correlations with the water content during doenjang-meju fermentation, indicating that water content might be a significant factor in determining the fungal

  7. Alcohol by fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Tamoki, H.

    1973-08-22

    Alcohol was obtained by culturing Saccharomyces diastaticus and S. cerevisiae on a medium containing saccharified starch as the main carbon source. Starch was saccharified with either acid or enzyme. Thus, 185 ml fermented mash (10.52% EtOH) was obtained by culturing yeast starter on 200 ml saccharified solution containing yeast extract 2 and peptone 2 g for 94 hours at 30 degrees; the saccharified solution was prepared by adding 0.006 mole NaCl, 0.001 mole CaCl2, and 40 mg bacterial dextrinogenic amylase to 20% potato starch suspension and allowed to react for 30 minutes at 75 degrees.

  8. Comparison of in-house and commercial real time-PCR based carbapenemase gene detection methods in Enterobacteriaceae and non-fermenting gram-negative bacterial isolates.

    Science.gov (United States)

    Smiljanic, M; Kaase, M; Ahmad-Nejad, P; Ghebremedhin, B

    2017-07-10

    Carbapenemase-producing gram-negative bacteria are increasing globally and have been associated with outbreaks in hospital settings. Thus, the accurate detection of these bacteria in infections is mandatory for administering the adequate therapy and infection control measures. This study aimed to establish and evaluate a multiplex real-time PCR assay for the simultaneous detection of carbapenemase gene variants in gram-negative rods and to compare the performance with a commercial RT-PCR assay (Check-Direct CPE). 116 carbapenem-resistant Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter baumannii isolates were genotyped for carbapenemase genes by PCR and sequencing. The defined isolates were used for the validation of the in-house RT-PCR by use of designed primer pairs and probes. Among the carbapenem-resistant isolates the genes bla KPC , bla VIM , bla NDM or bla OXA were detected. Both RT-PCR assays detected all bla KPC , bla VIM and bla NDM in the isolates. The in-house RT-PCR detected 53 of 67 (79.0%) whereas the commercial assay detected only 29 (43.3%) of the OXA genes. The in-house sufficiently distinguished the most prevalent OXA types (23-like and 48-like) in the melting curve analysis and direct detection of the genes from positive blood culture vials. The Check-Direct CPE and the in-house RT-PCR assay detected the carbapenem resistance from solid culture isolates. Moreover, the in-house assay enabled the identification of carbapenemase genes directly from positive blood-culture vials. However, we observed insufficient detection of various OXA genes in both assays. Nevertheless, the in-house RT-PCR detected the majority of the OXA type genes in Enterobacteriaceae and A. baumannii.

  9. Results from a 13-Year Prospective Cohort Study Show Increased Mortality Associated with Bloodstream Infections Caused by Pseudomonas aeruginosa Compared to Other Bacteria.

    Science.gov (United States)

    Thaden, Joshua T; Park, Lawrence P; Maskarinec, Stacey A; Ruffin, Felicia; Fowler, Vance G; van Duin, David

    2017-06-01

    The impact of bacterial species on outcome in bloodstream infections (BSI) is incompletely understood. We evaluated the impact of bacterial species on BSI mortality, with adjustment for patient, bacterial, and treatment factors. From 2002 to 2015, all adult inpatients with monomicrobial BSI caused by Staphylococcus aureus or Gram-negative bacteria at Duke University Medical Center were prospectively enrolled. Kaplan-Meier curves and multivariable Cox regression with propensity score models were used to examine species-specific bacterial BSI mortality. Of the 2,659 enrolled patients, 999 (38%) were infected with S. aureus, and 1,660 (62%) were infected with Gram-negative bacteria. Among patients with Gram-negative BSI, Enterobacteriaceae (81% [1,343/1,660]) were most commonly isolated, followed by non-lactose-fermenting Gram-negative bacteria (16% [262/1,660]). Of the 999 S. aureus BSI isolates, 507 (51%) were methicillin resistant. Of the 1,660 Gram-negative BSI isolates, 500 (30%) were multidrug resistant. The unadjusted time-to-mortality among patients with Gram-negative BSI was shorter than that of patients with S. aureus BSI (P = 0.003), due to increased mortality in patients with non-lactose-fermenting Gram-negative BSI generally (P < 0.0001) and Pseudomonas aeruginosa BSI (n = 158) in particular (P < 0.0001). After adjustment for patient demographics, medical comorbidities, bacterial antibiotic resistance, timing of appropriate antibiotic therapy, and source control in patients with line-associated BSI, P. aeruginosa BSI remained significantly associated with increased mortality (hazard ratio = 1.435; 95% confidence interval = 1.043 to 1.933; P = 0.02). P. aeruginosa BSI was associated with increased mortality relative to S. aureus or other Gram-negative BSI. This effect persisted after adjustment for patient, bacterial, and treatment factors. Copyright © 2017 American Society for Microbiology.

  10. High pressure inactivation of Pseudomonas in black truffle - comparison with Pseudomonas fluorescens in tryptone soya broth

    Science.gov (United States)

    Ballestra, Patricia; Verret, Catherine; Cruz, Christian; Largeteau, Alain; Demazeau, Gerard; El Moueffak, Abdelhamid

    2010-03-01

    Pseudomonas is one of the most common genera in black Perigord truffle. Its inactivation by high pressure (100-500 MPa/10 min) applied on truffles at sub-zero or low temperatures was studied and compared with those of Pseudomonas fluorescens in tryptone soya broth. Pressurization of truffles at 300 MPa/4 °C reduced the bacterial count of Pseudomonas by 5.3 log cycles. Higher pressures of 400 or 500 MPa, at 4 °C or 20 °C, allowed us to slightly increase the level of destruction to the value of ca. 6.5 log cycles but did not permit us to completely inactivate Pseudomonas. The results showed a residual charge of about 10 CFU/g. Pressure-shift freezing of truffles, which consists in applying a pressure of 200 MPa/-18 °C for 10 min and then quickly releasing this pressure to induce freezing, reduced the population of Pseudomonas by 3.3 log cycles. The level of inactivation was higher than those obtained with conventional freezing. Endogenous Pseudomonas in truffle was shown to be more resistant to high pressure treatments than P. fluorescens used for inoculation of broths.

  11. Biodegradation Of 4-Chlorobiphenyl By Pseudomonas synxantha

    Directory of Open Access Journals (Sweden)

    Dhanjal Noorpreet Inder Kaur

    2014-10-01

    Full Text Available The stabilization and disposal of polychlorinated biphenyls (PCBs from soil environment and wetland areas is of great concern for health and safety. Wetland remediation with microorganisms is an approach for treating PCBs. A bacterial strain was isolated from hydrocarbon contaminated soil of Ropar, Punjab, able to degrade PCBs under aerobic conditions. The percentage of degradation with 100 mM/ml of 4-chlorobiphenyl was up to 90%. Degradation was monitored by mass spectrometry, high performance liquid chromatography and spectrophotometrically, showing that 4-chlorobiphenyl was degraded almost completely. The bacterial strain was identified as Pseudomonas synxantha by 16sRNA sequencing method. This is the first report of 4-chlorobiphenyl degradation by Pseudomonas synxantha.

  12. Zoonotic bacterial populations, gut fermentation characteristics and methane production in feedlot steers during oral nitroethane treatment and after the feeding of an experimental chlorate product.

    Science.gov (United States)

    Gutierrez-Bañuelos, Hector; Anderson, Robin C; Carstens, Gordon E; Slay, Lisa J; Ramlachan, Nicole; Horrocks, Shane M; Callaway, Todd R; Edrington, Thomas S; Nisbet, David J

    2007-02-01

    Nitroethane inhibits the growth of certain zoonotic pathogens such as Campylobacter and Salmonella spp., foodborne pathogens estimated to cause millions of human infections each year, and enhances the Salmonella- and Escherichia coli-killing effect of an experimental chlorate product being developed as a feed additive to kill these bacteria immediately pre-harvest. Limited studies have shown that nitroethane inhibits ruminal methane production, which represents a loss of 2-12% of the host's gross energy intake and contributes to global warming and destruction of the ozone layer. The present study was conducted to assess the effects of 14-day oral nitroethane administration, 0 (0X), 80 (1X) or 160 (2X)mg nitroethane/kg body weight per day on ruminal and fecal E. coli and Campylobacter, ruminal and fecal methane-producing and nitroethane-reducing activity, whole animal methane emissions, and ruminal and fecal fermentation balance in Holstein steers (n=6 per treatment) averaging 403+/-26 (SD) kg BW. An experimental chlorate product was fed the day following the last nitroethane administration to determine effects on E. coli and Campylobacter. The experimental chlorate product decreased (P0.05) E. coli concentrations by 1000- and 10-fold by 24 and 48 h, respectively, after chlorate feeding when compared to pre-treatment concentrations (>5.7 log(10) colony forming units/g). No effects (P>0.05) of nitroethane or the experimental chlorate product were observed on fecal Campylobacter concentrations; Campylobacter were not recovered from ruminal contents. Nitroethane treatment decreased (P0.05) methane-producing and nitroethane-reducing activities (P0.05). Ruminal accumulations of acetate decreased (P0.05) of nitroethane was observed on propionate, butyrate or the acetate to propionate ratio. Whole animal methane emissions, expressed as L/day or as a proportion of gross energy intake (%GEI), were unaffected by nitroethane treatment (P>0.05), and were not correlated (P>0

  13. Specific Genomic Fingerprints of Phosphate Solubilizing Pseudomonas Strains Generated by Box Elements

    Science.gov (United States)

    Javadi Nobandegani, Mohammad Bagher; Saud, Halimi Mohd; Yun, Wong Mui

    2014-01-01

    Primers corresponding to conserved bacterial repetitive of BOX elements were used to show that BOX-DNA sequences are widely distributed in phosphate solubilizing Pseudomonas strains. Phosphate solubilizing Pseudomonas was isolated from oil palm fields (tropical soil) in Malaysia. BOX elements were used to generate genomic fingerprints of a variety of Pseudomonas isolates to identify strains that were not distinguishable by other classification methods. BOX-PCR, that derived genomic fingerprints, was generated from whole purified genomic DNA by liquid culture of phosphate solubilizing Pseudomonas. BOX-PCR generated the phosphate solubilizing Pseudomonas specific fingerprints to identify the relationship between these strains. This suggests that distribution of BOX elements' sequences in phosphate solubilizing Pseudomonas strains is the mirror image of their genomic structure. Therefore, this method appears to be a rapid, simple, and reproducible method to identify and classify phosphate solubilizing Pseudomonas strains and it may be useful tool for fast identification of potential biofertilizer strains. PMID:25580434

  14. Fermentation Industry.

    Science.gov (United States)

    Grady, C. P. L., Jr.; Grady, J. K.

    1978-01-01

    Presents a literature review of wastes from the fermentation industry, covering publications of 1976-77. This review focuses on: (1) alcoholic beverage production; (2) pharmaceuticals and biochemicals production; and (3) biomass production. A list of 62 references is also presented. (HM)

  15. Solid state fermentation of broiler litter for production of biocontrol agents.

    Science.gov (United States)

    Adams, T T; Eiteman, M A; Hanel, B M

    2002-03-01

    Several varieties of heat-sterilized broiler litter with 60% (wet basis, wb) moisture content were substrate in solid-state fermentations to produce biocontrol agents. Litter varieties included litter produced by one flock of broilers from medicated and non-medicated controlled rations, and litter produced by two flocks and four flocks on a single application of bedding material from medicated commercial sources. Litter preparations were inoculated with monocultures of Bacillus thuringiensis serovar japonensis strain Buibui, a pathogen of Japanese beetle larvae (Popillia japonica), or Pseudomonas fluorescens 2-79. B. thuringiensis did not grow in unextracted 1-flock litter nor in water extracted litter, but grew in methanol extracted litter to 5 x 10(10) cell forming units (CFU)/g litter (dry weight, dw) and a spore count of 1 x 10(10) CFU/g litter (dw). B. thuringiensis also grew in unprocessed 2-flock and 4-flock litter, achieving cell counts of 3 x 10(9) and 1 x 10(9) CFU/g litter (dw), respectively, and spore counts of 1 x 10(9) CFU/g litter (dw). P. fluorescens grew in medicated 1-flock litter with no extraction to a cell density greater than 4 x 10(11) CFU/g litter (dw). Bioassays in soil containing over 0.5% (db) litter fermented with B. thuringiensis resulted in over 90% mortality in 21 days for first instars of Japanese beetle when compared to a control treatment using compost without fermented litter. The investigations demonstrate that bacterial biocontrol agents produced via solid substrate fermentations using broiler poultry litter have potential in biocontrol applications in the soil environment.

  16. Monocyte Profiles in Critically Ill Patients With Pseudomonas Aeruginosa Sepsis

    Science.gov (United States)

    2017-02-02

    Pseudomonas Infections; Pseudomonas Septicemia; Pseudomonas; Pneumonia; Pseudomonal Bacteraemia; Pseudomonas Urinary Tract Infection; Pseudomonas Gastrointestinal Tract Infection; Sepsis; Sepsis, Severe; Critically Ill

  17. [Isolation, identification and characterization of rice rhizobacterium Pseudomonas aeruginosa PA1201 producing high level of biopesticide "Shenqinmycin" and phenazine-1-carboxamide].

    Science.gov (United States)

    Zhou, Lian; Jiang, Haixia; Jin, Kaiming; Sun, Shuang; Zhang, Wei; Zhang, Xuehong; He, Ya-Wen

    2015-04-04

    To identify bacterial strains with the inhibitory activity to rice pathogens, and to evaluate their potentials for the development of new biopesticides. Rice rhizosphere Pseudomonas strains were isolated using 1-aminocyclopropane-1-carboxylic acid as the sole carbon source. Strain PA1201 was further identified through morphological analysis, biochemical characterization, 16S rDNA sequence analysis and phospholipid fatty acid profiling. Qualitative and quantitative analysis of the production of the green pesticide Shenqinmycin as well as phenazine-1-carboxamide produced by PA1201 was done by HPLC. Cytotoxicity of PA1201 was evaluated using human alveolar epithelial cell line A549 and Drosophila melanogaster as hosts. Strain PA1201 inhibited Rhizotonia solani Kuhn and Xanthomonas oryzae pv. oryzae, the causal agents of rice sheath blight and bacterial blight, respectively. It was further identified as Pseudomonas aeruginosa PA1201, which produces shenqinmycin and phenazine-1-carboxamide. The fermentation titer of shenqinmycin and phenazine-1-carboxamide in the PPM medium was 81.7 mg/L and 18. 1 mg/L, respectively. In the medium supplemented with soybean meal and corn steep liquor, the level of shenqinmycin and phenazine-1-carboxamide reached 926. 9 mg/L and 489. 5 mg/L. PA1201 also produced high level of extracellular protease and was toxic to human cell line and fruit fly. Strain PA1201 could be engineered for higher yield of Shenqinmycin or for a new biopesticide.

  18. Airway epithelial cell tolerance to Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Verghese Margrith W

    2005-04-01

    Full Text Available Abstract Background The respiratory tract epithelium is a critical environmental interface that regulates inflammation. In chronic infectious airway diseases, pathogens may permanently colonize normally sterile luminal environments. Host-pathogen interactions determine the intensity of inflammation and thus, rates of tissue injury. Although many cells become refractory to stimulation by pathogen products, it is unknown whether the airway epithelium becomes either tolerant or hypersensitive in the setting of chronic infection. Our goals were to characterize the response of well-differentiated primary human tracheobronchial epithelial cells to Pseudomonas aeruginosa, to understand whether repeated exposure induced tolerance and, if so, to explore the mechanism(s. Methods The apical surface of well-differentiated primary human tracheobronchial epithelial cell cultures was repetitively challenged with Pseudomonas aeruginosa culture filtrates or the bacterial media control. Toxicity, cytokine production, signal transduction events and specific effects of dominant negative forms of signaling molecules were examined. Additional experiments included using IL-1β and TNFα as challenge agents, and performing comparative studies with a novel airway epithelial cell line. Results An initial challenge of the apical surface of polarized human airway epithelial cells with Pseudomonas aeruginosa culture filtrates induced phosphorylation of IRAK1, JNK, p38, and ERK, caused degradation of IκBα, generation of NF-κB and AP-1 transcription factor activity, and resulted in IL-8 secretion, consistent with activation of the Toll-like receptor signal transduction pathway. These responses were strongly attenuated following a second Pseudomonas aeruginosa, or IL-1β, but not TNFα, challenge. Tolerance was associated with decreased IRAK1 protein content and kinase activity and dominant negative IRAK1 inhibited Pseudomonas aeruginosa -stimulated NF-κB transcriptional

  19. [Pseudomonas genus bacteria on weeds].

    Science.gov (United States)

    Gvozdiak, R I; Iakovleva, L M; Pasichnik, L A; Shcherbina, T N; Ogorodnik, L E

    2005-01-01

    It has been shown in the work that the weeds (couch-grass and ryegrass) may be affected by bacterial diseases in natural conditions, Pseudomonas genus bacteria being their agents. The isolated bacteria are highly-aggressive in respect of the host-plant and a wide range of cultivated plants: wheat, rye, oats, barley, apple-tree and pear-tree. In contrast to highly aggressive bacteria isolated from the affected weeds, bacteria-epi phytes isolated from formally healthy plants (common amaranth, orache, flat-leaved spurge, field sow thistle, matricary, common coltsfoot, narrow-leaved vetch) and identified as P. syringae pv. coronafaciens, were characterized by weak aggression. A wide range of ecological niches of bacteria evidently promote their revival and distribution everywhere in nature.

  20. Occurrence of unusual non-fermentative gram negative bacilli in ...

    African Journals Online (AJOL)

    Non-fermentative Gram-negative bacilli (NFGNB) other than Pseudomonas and Acinetobacter species have emerged as nosocomial pathogens. No much data is currently available concerning the occurrence of these types of bacteria in Zagazig University Hospitals (ZUHs). In this study, the occurrence as well as the ...

  1. Antibiotic therapy against Pseudomonas aeruginosa in cystic fibrosis : a European consensus

    NARCIS (Netherlands)

    Döring, G; Conway, S P; Heijerman, H G; Hodson, M E; Høiby, N; Smyth, A; Touw, D J

    2000-01-01

    Cystic fibrosis (CF) is the most common lethal hereditary disorder with autosomal recessive heredity in caucasians. The majority of CF patients suffer from chronic respiratory infection with the opportunistic bacterial pathogen Pseudomonas aeruginosa. No consensus among clinicians has been reached

  2. Initial Pseudomonas aeruginosa infection in patients with cystic fibrosis: characteristics of eradicated and persistent isolates

    DEFF Research Database (Denmark)

    Tramper-Stranders, G. A.; van der Ent, C. K.; Molin, Søren

    2012-01-01

    Clin Microbiol Infect 2012; 18: 567574 Abstract Despite intensive eradication therapy, some CF patients with early Pseudomonas aeruginosa infection rapidly develop a chronic infection. To elucidate factors associated with this persistence, bacterial characteristics of early P. aeruginosa isolates...

  3. Bacterial Isolates Associated with Pelvic Inflammatory Disease ...

    African Journals Online (AJOL)

    Results: Out of the 100 samples analysed, 43% yielded pure cultures of bacterial isolates, 2% yielded mixed cultures while no bacterial growths were recorded from the remaining 55% samples. Organisms encountered were Staphylococcus aureus (16%), Escherichia coli (10%), Streptococcus faecalis (8%), Pseudomonas ...

  4. Local domestication of lactic acid bacteria via cassava beer fermentation

    National Research Council Canada - National Science Library

    Colehour, Alese M; Meadow, James F; Liebert, Melissa A; Cepon-Robins, Tara J; Gildner, Theresa E; Urlacher, Samuel S; Bohannan, Brendan J M; Snodgrass, J Josh; Sugiyama, Lawrence S

    2014-01-01

    .... Fermented chicha samples were collected from seven Shuar households in two neighboring villages in the Morona-Santiago region of Ecuador, and the composition of the bacterial communities within each...

  5. Inoculation of starter cultures in a semi-dry coffee (Coffea arabica) fermentation process.

    Science.gov (United States)

    Evangelista, Suzana Reis; Miguel, Maria Gabriela da Cruz Pedrozo; Cordeiro, Cecília de Souza; Silva, Cristina Ferreira; Pinheiro, Ana Carla Marques; Schwan, Rosane Freitas

    2014-12-01

    The aim of this study was to evaluate the use of yeasts as starter cultures in coffee semi-dry processing. Arabica coffee was inoculated with one of the following starter cultures: Saccharomyces cerevisiae UFLA YCN727, S. cerevisiae UFLA YCN724, Candida parapsilosis UFLA YCN448 and Pichia guilliermondii UFLA YCN731. The control was not inoculated with a starter culture. Denaturing gradient gel electrophoresis (DGGE) was used to assess the microbial population, and organic acids and volatile compounds were quantified by HPLC and HS-SPME/GC, respectively. Sensory analyses were evaluated using the Temporal Dominance of Sensations (TDS). DGGE analysis showed that the inoculated yeasts were present throughout the fermentation. Other yeast species were also detected, including Debaryomyces hansenii, Cystofilobasidium ferigula and Trichosporon cavernicola. The bacterial population was diverse and was composed of the following genera: Weissella, Leuconostoc, Gluconobacter, Pseudomonas, Pantoea, Erwinia and Klebsiella. Butyric and propionic acids, were not detected in any treatment A total of 47 different volatiles compounds have been identified. The coffee inoculated with yeast had a caramel flavor that was not detected in the control, as assessed by TDS. The use of starter cultures during coffee fermentation is an interesting alternative for obtaining a beverage quality with distinctive flavor. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Saccharomyces cerevisiae expressing bacteriophage endolysins reduce Lactobacillus contamination during fermentation

    Science.gov (United States)

    One of the challenges facing the fuel ethanol industry is the management of bacterial contamination during fermentation. Lactobacillus species are the predominant contaminants that decrease the profitability of biofuel production by reducing ethanol yields and causing “stuck” fermentations, which i...

  7. Yeasts are essential for cocoa bean fermentation.

    Science.gov (United States)

    Ho, Van Thi Thuy; Zhao, Jian; Fleet, Graham

    2014-03-17

    Cocoa beans (Theobroma cacao) are the major raw material for chocolate production and fermentation of the beans is essential for the development of chocolate flavor precursors. In this study, a novel approach was used to determine the role of yeasts in cocoa fermentation and their contribution to chocolate quality. Cocoa bean fermentations were conducted with the addition of 200ppm Natamycin to inhibit the growth of yeasts, and the resultant microbial ecology and metabolism, bean chemistry and chocolate quality were compared with those of normal (control) fermentations. The yeasts Hanseniaspora guilliermondii, Pichia kudriavzevii and Kluyveromyces marxianus, the lactic acid bacteria Lactobacillus plantarum and Lactobacillus fermentum and the acetic acid bacteria Acetobacter pasteurianus and Gluconobacter frateurii were the major species found in the control fermentation. In fermentations with the presence of Natamycin, the same bacterial species grew but yeast growth was inhibited. Physical and chemical analyses showed that beans fermented without yeasts had increased shell content, lower production of ethanol, higher alcohols and esters throughout fermentation and lesser presence of pyrazines in the roasted product. Quality tests revealed that beans fermented without yeasts were purplish-violet in color and not fully brown, and chocolate prepared from these beans tasted more acid and lacked characteristic chocolate flavor. Beans fermented with yeast growth were fully brown in color and gave chocolate with typical characters which were clearly preferred by sensory panels. Our findings demonstrate that yeast growth and activity were essential for cocoa bean fermentation and the development of chocolate characteristics. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  8. Fermentation of aqueous plant seed extracts by lactic acid bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Schafner, D.W.; Beuchat, R.L.

    1986-05-01

    The effects of lactic acid bacterial fermentation on chemical and physical changes in aqueous extracts of cowpea (Vigna unguiculata), peanut (Arachis hypogea), soybean (Glycine max), and sorghum (Sorghum vulgare) were studied. The bacteria investigated were Lactobacillus helveticus, L. delbrueckii, L. casei, L. bulgaricus, L. acidophilus, and Streptococcus thermophilus. Organisms were inoculated individually into all of the seed extracts; L. bulgaricus and S. thermophilus were also evaluated together as inocula for fermenting the legume extracts. During fermentation, bacterial population and changes in titratable acidity, pH, viscosity, and color were measured over a 72 h period at 37 degrees C. Maximum bacterial populations, titratable acidity, pH, and viscosity varied depending upon the type of extract and bacterial strain. The maximum population of each organism was influenced by fermentable carbohydrates, which, in turn, influenced acid production and change in pH. Change in viscosity was correlated with the amount of protein and titratable acidity of products. Color was affected by pasteurization treatment and fermentation as well as the source of extract. In the extracts inoculated simultaneously with L. bulgaricus and S. thermophilus, a synergistic effect resulted in increased bacterial populations, titratable acidity, and viscosity, and decreased pH in all the legume extracts when compared to the extracts fermented with either of these organisms individually. Fermented extracts offer potential as substitutes for cultured dairy products. 24 references.

  9. The cytotoxin of Pseudomonas aeruginosa : Cytotoxicity requires proteolytic activation

    NARCIS (Netherlands)

    Orlik-Eisel, Gabriele; Lutz, Frieder; Henschen, Agnes; Eisel, Ulrich; Struckmeier, Martin; Kräuter, Josef; Niemann, Heiner

    The primary structure of a cytotoxin from Pseudomonas aeruginosa was determined by sequencing of the structural gene. The cytotoxin (31,700 Mr) lacks an N-terminal signal sequence for bacterial secretion but contains a pentapeptide consensus sequence commonly found in prokaryotic proteins which

  10. Rhamnolipid stimulates uptake of hydrophobic compounds by Pseudomonas aeruginosa

    NARCIS (Netherlands)

    Noordman, WH; Janssen, DB

    The biodegradation of hexadecane by five biosurfactant-producing bacterial strains (Pseudomonas aeruginosa UG2, Acinetobacter calcoaceticus RAG1, Rhodococcus erythropolis DSM 43066, R. erythropolis ATCC 19558, and strain BCG112) was determined in the presence and absence of exogenously added

  11. Characterization of Pseudomonas species causing brown blotch of Agaricus bisporis.

    NARCIS (Netherlands)

    Wolf, van der J.M.; Kastelein, P.; Krijger, M.C.; Hendriks, M.J.A.; Baars, J.J.P.; Amsing, J.G.M.; Lee, van der T.A.J.; Warris, S.

    2016-01-01

    Bacterial blotch is occasionally causing damage in the production of common mushroom (Agaricus bisporus). The disease is found worldwide and can be caused by different fluorescent Pseudomonas species present in casing material. For identification of the causative agents of blotch in the Netherlands

  12. Isolation and characterization of Pseudomonas resistant to heavy ...

    African Journals Online (AJOL)

    Isolation and characterization of Pseudomonas resistant to heavy metals and poly aromatics hydrocarbons (PAHs) from Persian Gulf sediments. ... Among 10 bacterial species isolated from marine sediment, one strain represented high potential to grow in medium supplemented with copper and phenanthrene. Isolated ...

  13. Detection of Pseudomonas fluorescens from broth, water and ...

    African Journals Online (AJOL)

    Loop mediated isothermal amplification is rapid, highly sensitive and specifically developed method for detection of bacterial infections. AprX gene for alkaline metalloprotease of Pseudomonas fluorescens was used to design four primers and loop mediated isothermal amplification (LAMP) conditions were standardized for ...

  14. Identification of a New Marine Bacterial Strain SD8 and Optimization of Its Culture Conditions for Producing Alkaline Protease.

    Science.gov (United States)

    Cui, Hongxia; Yang, Muyang; Wang, Liping; Xian, Cory J

    2015-01-01

    While much attention has been given to marine microorganisms for production of enzymes, which in general are relatively more stable and active compared to those from plants and animals, studies on alkaline protease production from marine microorganisms have been very limited. In the present study, the alkaline protease producing marine bacterial strain SD8 isolated from sea muds in the Geziwo Qinhuangdao sea area of China was characterized and its optimal culture conditions were investigated. Strain SD8 was initially classified to belong to genus Pseudomonas by morphological, physiological and biochemical characterizations, and then through 16S rDNA sequence it was identified to be likely Pseudomonas hibiscicola. In addition, the culture mediums, carbon sources and culture conditions of strain SD8 were optimized for maximum production of alkaline protease. Optimum enzyme production (236U/mL when cultured bacteria being at 0.75 mg dry weight/mL fermentation broth) was obtained when the isolate at a 3% inoculum size was grown in LB medium at 20 mL medium/100mL Erlenmeyer flask for 48h culture at 30°C with an initial of pH 7.5. This was the first report of strain Pseudomonas hibiscicola secreting alkaline protease, and the data for its optimal cultural conditions for alkaline protease production has laid a foundation for future exploration for the potential use of SD8 strain for alkaline protease production.

  15. Inhibition of Quorum Sensing-Controlled Virulence Factors and Biofilm Formation in Pseudomonas aeruginosa by Culture Extract from Novel Bacterial Species of Paenibacillus Using a Rat Model of Chronic Lung Infection

    Directory of Open Access Journals (Sweden)

    Saad Musbah Alasil

    2015-01-01

    Full Text Available Quorum sensing (QS is a key regulator of virulence factors and biofilm formation in Gram-negative bacteria such as Pseudomonas aeruginosa. Microorganisms that inhabit soil are of strategic importance in the discovery of compounds with anti-QS properties. The objective of the study was to test the culture extract of a taxonomically novel species of Paenibacillus strain 139SI for its inhibitory effects on the QS-controlled virulence factors and biofilm formation of Pseudomonas aeruginosa both in vitro and in vivo. The Paenibacillus sp. culture extract was used to test its anti-QS effects on the LasA protease, LasB elastase, pyoverdin production, and biofilm formation of P. aeruginosa as well as evaluate its therapeutic effects on lung bacteriology, pathology, hematological profile, and serum antibody responses of experimental animals in a rat model of chronic lung infection. Results showed significant decrease in the activities of QS-controlled LasA protease, LasB elastase pyoverdin, and biofilm formation of P. aeruginosa caused by the culture extract. Moreover, the extract significantly prolonged the survival times of rats and facilitated the clearance of biofilm infections from infected lungs. In conclusion, the antiquorum sensing effects of culture extract from a novel species of Paenibacillus provide new insights to combat biofilm-associated infections.

  16. Investigating the diversity of pseudomonas spp. in soil using culture dependent and independent techniques.

    Science.gov (United States)

    Li, Lili; Abu Al-Soud, Waleed; Bergmark, Lasse; Riber, Leise; Hansen, Lars H; Magid, Jakob; Sørensen, Søren J

    2013-10-01

    Less than 1 % of bacterial populations present in environmental samples are culturable, meaning that cultivation will lead to an underestimation of total cell counts and total diversity. However, it is less clear whether this is also true for specific well-defined groups of bacteria for which selective culture media is available. In this study, we use culture dependent and independent techniques to describe whether isolation of Pseudomonas spp. on selective nutrient-poor NAA 1:100 agar-medium can reflect the full diversity, found by pyrosequencing, of the total soil Pseudomonas community in an urban waste field trial experiment. Approximately 3,600 bacterial colonies were isolated using nutrient-poor NAA 1:100 medium from soils treated with different fertilizers; (i) high N-level sewage sludge (SA), (ii) high N-level cattle manure (CMA), and (iii) unfertilized control soil (U). Based on Pseudomonas specific quantitative-PCR and Pseudomonas CFU counts, less than 4 % of Pseudomonas spp. were culturable using NAA 1:100 medium. The Pseudomonas selectivity and specificity of the culture medium were evaluated by 454 pyrosequencing of 16S rRNA gene amplicons generated using Bacteria- and Pseudomonas-specific primers. Pyrosequencing results showed that most isolates were Pseudomonas and that the culturable fraction of Pseudomonas spp. reflects most clusters of the total Pseudomonas diversity in soil. This indicates that NAA 1:100 medium is highly selective for Pseudomonas species, and reveals the ability of NAA 1:100 medium to culture mostly the dominant Pseudomonas species in soil.

  17. Bacterial Keratitis: Risk Factors and Causative Agents | Bataineh ...

    African Journals Online (AJOL)

    Objectives: to describe the clinical, microbiological characteristics and risk factors of. Bacterial Keratitis at Prince Zeid and Rashed ... Offending organisms were isolated in 17(50%) cases only. Pseudomonas in 10(58.8%) cases ... Pseudomonas was the major causative organism. Proper sampling and microbiological ...

  18. Enzymatic removal and disinfection of bacterial biofilms.

    OpenAIRE

    Johansen, C; Falholt, P; Gram, L

    1997-01-01

    Model biofilms of Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas fluorescens, and Pseudomonas aeruginosa were made on steel and polypropylene substrata. Plaque-resembling biofilms of Streptococcus mutans, Actinomyces viscosus, and Fusobacterium nucleatum were made on saliva-coated hydroxyapatite. The activity of enzymes against bacterial cells in biofilm was measured by fluorescence microscopy and an indirect conductance test in which evolution of carbon dioxide was measured. ...

  19. Wine fermentation microbiome: a landscape from different Portuguese wine appellations

    Science.gov (United States)

    Pinto, Cátia; Pinho, Diogo; Cardoso, Remy; Custódio, Valéria; Fernandes, Joana; Sousa, Susana; Pinheiro, Miguel; Egas, Conceição; Gomes, Ana C.

    2015-01-01

    Grapes and wine musts harbor a complex microbiome, which plays a crucial role in wine fermentation as it impacts on wine flavour and, consequently, on its final quality and value. Unveiling the microbiome and its dynamics, and understanding the ecological factors that explain such biodiversity, has been a challenge to oenology. In this work, we tackle this using a metagenomics approach to describe the natural microbial communities, both fungal and bacterial microorganisms, associated with spontaneous wine fermentations. For this, the wine microbiome, from six Portuguese wine appellations, was fully characterized as regards to three stages of fermentation – Initial Musts (IM), and Start and End of alcoholic fermentations (SF and EF, respectively). The wine fermentation process revealed a higher impact on fungal populations when compared with bacterial communities, and the fermentation evolution clearly caused a loss of the environmental microorganisms. Furthermore, significant differences (p fermentations in wine must samples as Saccharomyces and non-Saccharomyces yeasts (as Lachancea, Metschnikowia, Hanseniaspora, Hyphopichia, Sporothrix, Candida, and Schizosaccharomyces). Among bacterial communities, the most abundant family was Enterobacteriaceae; though families of species associated with the production of lactic acid (Lactobacillaceae, Leuconostocaceae) and acetic acid (Acetobacteriaceae) were also detected. Interestingly, a biogeographical correlation for both fungal and bacterial communities was identified between wine appellations at IM suggesting that each wine region contains specific and embedded microbial communities which may contribute to the uniqueness of regional wines. PMID:26388852

  20. Bacterial agents and sensitivity pattern of neonatal conjuctivitis in ...

    African Journals Online (AJOL)

    Pseudomonas aeruginosa and Neisseria gonorrhea showed 100% sensitivity to ceftazidime and ceftriaxone respectively. Conclusion: Staphylococcus aureus is the commonest bacterial agent responsible for neonatal conjunctivitis. Staphylococcus aureus was most sensitive to ceftriaxone. Key words: Conjuctivitis ...

  1. Effect of osmotic stress on plant growth promoting Pseudomonas spp.

    Science.gov (United States)

    Sandhya, V; Ali, Sk Z; Venkateswarlu, B; Reddy, Gopal; Grover, Minakshi

    2010-10-01

    In this study we isolated and screened drought tolerant Pseudomonas isolates from arid and semi arid crop production systems of India. Five isolates could tolerate osmotic stress up to -0.73 MPa and possessed multiple PGP properties such as P-solubilization, production of phytohormones (IAA, GA and cytokinin), siderophores, ammonia and HCN however under osmotic stress expression of PGP traits was low compared to non-stressed conditions. The strains were identified as Pseudomonas entomophila, Pseudomonas stutzeri, Pseudomonas putida, Pseudomonas syringae and Pseudomonas monteilli respectively on the basis of 16S rRNA gene sequence analysis. Osmotic stress affected growth pattern of all the isolates as indicated by increased mean generation time. An increase level of intracellular free amino acids, proline, total soluble sugars and exopolysaccharides was observed under osmotic stress suggesting bacterial response to applied stress. Further, strains GAP-P45 and GRFHYTP52 showing higher levels of EPS and osmolytes (amino acids and proline) accumulation under stress as compared to non-stress conditions, also exhibited higher expression of PGP traits under stress indicating a relationship between stress response and expression of PGP traits. We conclude that isolation and screening of indigenous, stress adaptable strains possessing PGP traits can be a method for selection of efficient stress tolerant PGPR strains.

  2. Levofloxacin and Tobramycin for Severe Bacterial Keratouveitis.

    Science.gov (United States)

    Accorinti, Massimo; Colao, Lorena; Gilardi, Marta; Cecere, Michela; Salotti, Alessandra; Pesci, Francesca Romana

    2016-10-01

    To report on clinical features and outcome of severe bacterial keratouveitis. Twenty patients with severe bacterial keratouveitis treated with topical tobramycin and levofloxacin and oral levofloxacin were included. Main outcome measures were ulcers location, bacterial isolates, risk factors, visual prognosis. Centrally located ulcer/abscess was present in 65% of patients. Contact lens (CL) wear was the most common risk factor (70%). Bacterial isolates were observed in 58% of patients, none resistant to tobramycin and levofloxacin. Pseudomonas aeruginosa was found in 47% of positive cases and in 64% of CL wearers. After therapy, the mean visual acuity improved significantly (p levofloxacin and oral levofloxacin are effective in the treatment of bacterial keratouveitis.

  3. Isolation, screening, and optimization of the fermentation conditions of highly cellulolytic bacteria from the hindgut of Holotrichia parallela larvae (Coleoptera: Scarabaeidae).

    Science.gov (United States)

    Sheng, Ping; Huang, Shengwei; Wang, Qi; Wang, Ailing; Zhang, Hongyu

    2012-05-01

    From the hindgut contents of Holotrichia parallela, 93 cellulolytic bacterial isolates were isolated after enrichment in carboxymethyl cellulose medium. Among these isolates, a novel bacterium, designated HP207, with the highest endoglucanase productivity was selected for further study. This bacterium was identified as Pseudomonas sp. based on the results of the 16S ribosomal DNA analysis, morphological characteristics, and biochemical properties. The production of the endoglucanase was optimized by varying various physical culture conditions using a submerged fermentation method. Under the optimized fermentation conditions, the maximum endoglucanase activity of 1.432 U mL(-1) in bacterial cultures was obtained, higher than those of the most widely studied bacteria and fungi, which are the attractive candidates for the commercial producer of cellulase. And the crude endoglucanase enzyme was also highly thermostable; approximately 55% of the original activity was maintained after pretreatment at 70 °C for 1 h. Thus, from the present study, the bacterium can be added up to the database of cellulolytic bacteria.

  4. Occurrence of Pseudomonas syringae pv. actinidiae in Jin Tao kiwi plants in Italy

    Directory of Open Access Journals (Sweden)

    G.M. Balestra

    2009-09-01

    Full Text Available During 2007–2008 bacterial canker caused damage in Jin Tao cv. kiwi (Actinidia chinensis plants grown in northern and central Italy. A bacterial population was repeatedly isolated from these plants. Based on morphological, physiological, biochemical and molecular tests, the causal agent was identified as Pseudomonas syringae pv. actinidiae (epidemiology and control strategies are discussed.

  5. Recent Insights into the Diversity, Frequency and Ecological Roles of Phenazines in Fluorescent Pseudomonas spp.

    Science.gov (United States)

    Phenazine compounds represent a large class of bacterial metabolites that are produced by some fluorescent Pseudomonas spp. and a few other bacterial genera. Phenazines were first noted in the scientific literature over 100 years ago, but for a long time were considered to be pigments of uncertain f...

  6. Review: Diversity of Microorganisms in Global Fermented Foods and Beverages

    Directory of Open Access Journals (Sweden)

    Jyoti Prakash Tamang

    2016-03-01

    Full Text Available Majority of global fermented foods is naturally fermented by culturalable and non-culturable microorganisms. Food fermentations represent an extremely valuable cultural heritage in most regions, and harbour a huge genetic potential of valuable but hitherto undiscovered strains. Holistic approaches for identification and complete profiling of both culturalable and non-culturable microorganisms in global fermented foods are interest to food microbiologists. The application of molecular and modern identification tools through culture-independent techniques has thrown new light on the diversity of a number of hitherto unknown and uncultivable microorganisms in naturally fermented foods. Functional bacterial groups (phylotypes may be reflected by their mRNA expression in a particular substrate and not by mere DNA-level detection. An attempt is made here to review the microbiology of some global fermented foods and alcoholic beverages.

  7. Control of Candida albicans metabolism and biofilm formation by Pseudomonas aeruginosa phenazines.

    Science.gov (United States)

    Morales, Diana K; Grahl, Nora; Okegbe, Chinweike; Dietrich, Lars E P; Jacobs, Nicholas J; Hogan, Deborah A

    2013-01-29

    Candida albicans has developmental programs that govern transitions between yeast and filamentous morphologies and between unattached and biofilm lifestyles. Here, we report that filamentation, intercellular adherence, and biofilm development were inhibited during interactions between Candida albicans and Pseudomonas aeruginosa through the action of P. aeruginosa-produced phenazines. While phenazines are toxic to C. albicans at millimolar concentrations, we found that lower concentrations of any of three different phenazines (pyocyanin, phenazine methosulfate, and phenazine-1-carboxylate) allowed growth but affected the development of C. albicans wrinkled colony biofilms and inhibited the fungal yeast-to-filament transition. Phenazines impaired C. albicans growth on nonfermentable carbon sources and led to increased production of fermentation products (ethanol, glycerol, and acetate) in glucose-containing medium, leading us to propose that phenazines specifically inhibited respiration. Methylene blue, another inhibitor of respiration, also prevented the formation of structured colony biofilms. The inhibition of filamentation and colony wrinkling was not solely due to lowered extracellular pH induced by fermentation. Compared to smooth, unstructured colonies, wrinkled colony biofilms had higher oxygen concentrations within the colony, and wrinkled regions of these colonies had higher levels of respiration. Together, our data suggest that the structure of the fungal biofilm promotes access to oxygen and enhances respiratory metabolism and that the perturbation of respiration by bacterial molecules such as phenazines or compounds with similar activities disrupts these pathways. These findings may suggest new ways to limit fungal biofilms in the context of disease. IMPORTANCE Many of the infections caused by Candida albicans, a major human opportunistic fungal pathogen, involve both morphological transitions and the formation of surface-associated biofilms. Through the

  8. KINETIC DISTRIBUTION MODEL OF EVAPORATION, BIOSORPTION AND BIODEGRADATION OF POLYCHLORINATED BIPHENYLS (PCBS) IN THE SUSPENSION OF PSEUDOMONAS STUTZERI. (R826652)

    Science.gov (United States)

    AbstractKinetics of distribution of PCBs in an active bacterial suspension of Pseudomonas stutzeri was studied by monitoring the evaporated amounts and the concentration remaining in the liquid medium with the biomass. To determine the biodegradation rate const...

  9. Controlled trial of cycled antibiotic prophylaxis to prevent initial Pseudomonas aeruginosa infection in children with cystic fibrosis

    NARCIS (Netherlands)

    Tramper-Stranders, G.A.; Wolfs, T.F.W.; van Haren Noman, S.; van Aalderen, W.M.C.; Nagelkerke, A.F.; Nuijsink, M.; Kimpen, J.L.L.; van der Ent, C.K.

    2010-01-01

    Background Initial pulmonary Pseudomonas aeruginosa infection in patients with cystic fibrosis (CF) is currently treated with intensive antibiotic therapy. At this stage, inflammation and tissue injury might have already occurred. Moreover, bacterial eradication is not always achieved. Prophylactic

  10. Pseudomonas aeruginosa biofilms in cystic fibrosis

    DEFF Research Database (Denmark)

    Høiby, Niels; Ciofu, Oana; Bjarnsholt, Thomas

    2010-01-01

    of mutations, slow growth and adaptation of the bacteria to the conditions in the lungs, and to antibiotic therapy. Low bacterial metabolic activity and increase of doubling times of the bacterial cells in CF lungs are responsible for some of the tolerance to antibiotics. Conventional resistance mechanisms......, such as chromosomal ß-lactamase, upregulated efflux pumps, and mutations of antibiotic target molecules in the bacteria, also contribute to the survival of P. aeruginosa biofilms. Biofilms can be prevented by early aggressive antibiotic prophylaxis or therapy, and they can be treated by chronic suppressive therapy.......The persistence of chronic Pseudomonas aeruginosa lung infections in cystic fibrosis (CF) patients is due to biofilm-growing mucoid (alginate-producing) strains. A biofilm is a structured consortium of bacteria, embedded in a self-produced polymer matrix consisting of polysaccharide, protein...

  11. High-Throughput Sequencing of Microbial Community Diversity and Dynamics during Douchi Fermentation

    Science.gov (United States)

    Tu, Zong-cai; Wang, Xiao-lan

    2016-01-01

    Douchi is a type of Chinese traditional fermented food that is an important source of protein and is used in flavouring ingredients. The end product is affected by the microbial community present during fermentation, but exactly how microbes influence the fermentation process remains poorly understood. We used an Illumina MiSeq approach to investigate bacterial and fungal community diversity during both douchi-koji making and fermentation. A total of 181,443 high quality bacterial 16S rRNA sequences and 221,059 high quality fungal internal transcribed spacer reads were used for taxonomic classification, revealing eight bacterial and three fungal phyla. Firmicutes, Actinobacteria and Proteobacteria were the dominant bacterial phyla, while Ascomycota and Zygomycota were the dominant fungal phyla. At the genus level, Staphylococcus and Weissella were the dominant bacteria, while Aspergillus and Lichtheimia were the dominant fungi. Principal coordinate analysis showed structural separation between the composition of bacteria in koji making and fermentation. However, multivariate analysis of variance based on unweighted UniFrac distances did identify distinct differences (p fermentation. This is the first investigation to integrate douchi fermentation and koji making and fermentation processes through this technological approach. The results provide insight into the microbiome of the douchi fermentation process, and reveal a structural separation that may be stratified by the environment during the production of this traditional fermented food. PMID:27992473

  12. Analysis of microbial diversity in Shenqu with different fermentation times by PCR-DGGE

    Directory of Open Access Journals (Sweden)

    Tengfei Liu

    Full Text Available Abstract Shenqu is a fermented product that is widely used in traditional Chinese medicine (TCM to treat indigestion; however, the microbial strains in the fermentation process are still unknown. The aim of this study was to investigate microbial diversity in Shenqu using different fermentation time periods. DGGE (polymerase chain reaction-denaturing gradient gel electrophoresis profiles indicated that a strain of Pediococcus acidilactici (band 9 is the predominant bacteria during fermentation and that the predominant fungi were uncultured Rhizopus, Aspergillus oryzae, and Rhizopus oryzae. In addition, pathogenic bacteria, such as Enterobacter cloacae, Klebsiella oxytoca, Erwinia billingiae, and Pantoea vagan were detected in Shenqu. DGGE analysis showed that bacterial and fungal diversity declined over the course of fermentation. This determination of the predominant bacterial and fungal strains responsible for fermentation may contribute to further Shenqu research, such as optimization of the fermentation process.

  13. Bilateral Granulomatous and Fibrinoheterophilic Otitis Interna due to Pseudomonas aeruginosa in a Captive Little Bustard ( Tetrax tetrax ).

    Science.gov (United States)

    Scala, Christopher; Langlois, Isabelle; Lemberger, Karin

    2015-06-01

    A captive juvenile little bustard ( Tetrax tetrax ) was presented for acute onset of right head tilt and right circling. The bird failed to respond to supportive care and systemic antibiotic therapy. A bilateral granulomatous and fibrinoheterophilic otitis interna due to Pseudomonas aeruginosa was diagnosed postmortem by histopathologic examination and bacterial culture. In bustards, Pseudomonas species have been documented in the normal bacterial flora of the oropharynx and are frequently reported in upper respiratory tract infections. This is the first report of a peripheral vestibular syndrome due to P aeruginosa otitis interna in a bustard species. Pseudomonas aeruginosa should be included as a possible cause of otitis and peripheral vestibular syndrome in bustards.

  14. Population Structure of Pseudomonas aeruginosa

    National Research Council Canada - National Science Library

    Lutz Wiehlmann; Gerd Wagner; Nina Cramer; Benny Siebert; Peter Gudowius; Gracia Morales; Thilo Köhler; Christian van Delden; Christian Weinel; Peter Slickers; Burkhard Tümmler

    2007-01-01

    The metabolically versatile Gram-negative bacterium Pseudomonas aeruginosa inhabits terrestrial, aquatic, animal-, human-, and plant-host-associated environments and is an important causative agent...

  15. GUT FERMENTATION SYNDROME

    African Journals Online (AJOL)

    boaz

    individuals who became intoxicated after consuming carbohydrates, which became fermented in the gastrointestinal tract. These claims of intoxication without drinking alcohol, and the findings on endogenous alcohol fermentation are now called Gut. Fermentation Syndrome. This review will concentrate on understanding ...

  16. Degradation of polynuclear aromatic hydrocarbons by two strains of Pseudomonas

    Directory of Open Access Journals (Sweden)

    Obinna C. Nwinyi

    Full Text Available ABSTRACT The goal of this investigation was to isolate competent polynuclear aromatic hydrocarbons degraders that can utilize polynuclear aromatic hydrocarbons of former industrial sites at McDoel Switchyard in Bloomington, Indiana. Using conventional enrichment method based on soil slurry, we isolated, screened and purified two bacterial species strains PB1 and PB2. Applying the ribotyping technique using the 16S rRNA gene analysis, the strains were assigned to the genus Pseudomonas (Pseudomonas plecoglossicida strain PB1 and Pseudomonas sp. PB2. Both isolates showed promising metabolic capacity on pyrene sprayed MS agar plates during the preliminary investigations. Using time course studies in the liquid cultures at calculated concentrations 123, 64, 97 and 94 ppm for naphthalene, chrysene, fluroanthene and pyrene, P. plecoglossicida strain PB1 and Pseudomonas sp. PB2 showed partial utilization of the polynuclear aromatic hydrocarbons. Naphthalene was degraded between 26% and 40%, chrysene 14% and 16%, fluroanthene 5% and 7%; pyrene 8% and 13% by P. plecoglossicida strain PB1 and Pseudomonas sp. PB2 respectively. Based on their growth profile, we developed a model R2 = 1 to predict the degradation rate of slow polynuclear aromatic hydrocarbon-degraders where all the necessary parameters are constant. From this investigation, we confirm that the former industrial site soil microbial communities may be explored for the biorestoration of the industrial site.

  17. Bacterial Keratitis

    Science.gov (United States)

    ... Español Eye Health / Eye Health A-Z Bacterial Keratitis Sections What Is Bacterial Keratitis? Bacterial Keratitis Symptoms ... Lens Care Bacterial Keratitis Treatment What Is Bacterial Keratitis? Leer en Español: ¿Qué Es la Queratitis Bacteriana? ...

  18. Dynamics of sodium dodecyl sulfate utilization andantibiotic susceptibility of strain Pseudomonas sp. ATCC19151

    Directory of Open Access Journals (Sweden)

    Jovčić B.

    2009-01-01

    Full Text Available Pseudomonas sp. ATCC19151 harbors a gene encoding a putative alkylsulfatase (sdsA. Here we report a growth ability of this strain in minimal media containing 0.5, 0.75, and 1% sodium dodecyl sulfate as the sole carbon source. The most prominent growth was detected for the minimal medium with 0.5% SDS, so this concentration of SDS was used to monitor Pseudomonas sp. ATCC19151 SDS biodegradation dynamics. Bacterial growth coincided with the disappearance of SDS. Antibiotic susceptibility was tested as well. Pseudomonas sp. ATCC19151 was resistant to six out of nine tested antibiotics, including ampicillin, tetracycline, chloramphenicol, tobramycin, nalidixic acid, and gentamycin.

  19. Antimutagenicity of milk fermented by Enterococcus faecium.

    Science.gov (United States)

    Belicová, A; Krajcovic, J; Dobias, J; Ebringer, L

    1999-01-01

    The diethyl ether extracts isolated from unfermented milk and milk fermented by Enterococcus faecium exhibited dose-dependent inhibition of mutagenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), nitrovin (NIT), 5-nitro-2-furylacrylic acid (NFA) and UV-irradiation on the Ames bacterial test (Salmonella typhimurium strains TA97 and TA100) and the unicellular flagellate Euglena gracilis. Overall, the fermented milk extract was the most active against UV-irradiation, less active against NIT and MNNG, and the least active against NFA on bacteria. The highest antibleaching effects were observed against MNNG. The differences between antimutagenic effects from fermented and unfermented milk extracts were determined to be statistically significant at the 0.95 CI level.

  20. Characterization of the microbial diversity in yacon spontaneous fermentation

    Science.gov (United States)

    Reina, L. D.; Pérez-Díaz, I. M.; Breidt, F.; Azcarate-Peril, M. A.; Medina, E.; Butz, N.V.

    2015-01-01

    The prebiotic fructooligosaccharides (FOS) content of yacon makes this root an attractive alternative for the supplementation of a variety of food products. The preservation of yacon by fermentation has been proposed as an alternative to increase the probiotic content of the root concomitantly with its shelf life. Thus the fermented yacon could have significant functional content. The objective of this research was to characterize the biochemistry and microbiology of spontaneous yacon fermentation and define the viability of the proposed process. The biochemical analysis of spontaneous heterolactic fermentation of yacon showed a progressive drop in pH with increased lactic and acetic acids, and the production of mannitol during fermentation. The microbial ecology of yacon fermentation was investigated using culture-dependent and culture-independent methods. Bacterial cell counts revealed a dominance of lactic acid bacteria (LAB) over yeasts, which were also present during fermentation. Results showed that the heterofermentative LAB were primarily Leuconostoc species, which dominated the fermentation. The fermentation of yacon by Leuconostoc spp. is thus presented as a viable method to achieve long term preservation of this root. PMID:25777679

  1. Effect of mixing during fermentation in yogurt manufacturing.

    Science.gov (United States)

    Aguirre-Ezkauriatza, E J; Galarza-González, M G; Uribe-Bujanda, A I; Ríos-Licea, M; López-Pacheco, F; Hernández-Brenes, C M; Alvarez, M M

    2008-12-01

    In traditional yogurt manufacturing, the yogurt is not agitated during fermentation. However, stirring could be beneficial, particularly for improving heat and mass transport across the fermentation tank. In this contribution, we studied the effect of low-speed agitation during fermentation on process time, acidity profile, and microbial dynamics during yogurt fermentation in 2 laboratory-scale fermenters (3 and 5 L) with different heat-transfer characteristics. Lactobacillus bulgaricus and Streptococcus thermophilus were used as fermenting bacteria. Curves of pH, lactic acid concentration, lactose concentration, and bacterial population profiles during fermentation are presented for static and low-agitation conditions during fermentation. At low-inoculum conditions, agitation reduced the processing time by shortening the lag phase. However, mixing did not modify the duration or the shape of the pH profiles during the exponential phase. In fermentors with poor heat-transfer characteristics, important differences in microbial dynamics were observed between the agitated and nonagitated fermentation experiments; that is, agitation significantly increased the observable specific growth rate and the final microbial count of L. bulgaricus.

  2. Low energy Kombucha fermented milk-based beverages

    Directory of Open Access Journals (Sweden)

    Milanović Spasenija D.

    2008-01-01

    Full Text Available This paper investigates manufacturing of fermented beverages from two types of milk (1 % w/w and 2.2 % w/w fat by applying of Kombucha, which contains several yeasts and bacterial strains. The starter was the inoculum produced from previous Kombucha fermentation. The applied starter concentrations were: 10 % v/v, 15 % v/v and 20 % v/v. Also, the traditional yoghurt starter was used to produce the control samples. All fermentations were performed at 42oC and the changes in the pH were monitored. The fermentation process was about three times faster in the control yoghurt than in the Kombucha samples. Influence of Kombucha inoculum concentration on the rate of fermentation appeared not to be significant. All fermentations were stopped when the pH reached 4.4. After the production, the quality of the fermented milk beverages with Kombucha was determined and compared with the quality of the control yoghurt samples. It was concluded that the difference in fat contents in milks affects the difference in quantities of other components in the fermented milk beverages with Kombucha. Sensory characteristics of the beverages manufactured from the partially skimmed milk are much better than those of the fermented beverages produced from the low fat milk.

  3. Antimicrobial effect of probiotic Lactobacillus spp. on Pseudomonas aeruginosa

    OpenAIRE

    Maysaa Kadhim Al-Malkey; Munira Ch. Ismeeal; Fahema Jabbar Abo Al-Hur; Sinaa W. Mohammed; Hanan J. Nayyef

    2017-01-01

    Objectives Study the antimicrobial effect of probiotics produced from Lactobacillus rhamnosus GG and Lactobacillus acidophilus on Pseudomonas aeruginosa isolated from burn and wound infection and their ability of protease production. Methods Swab samples were collected from 70 patients admitted at Burns Center/Al-Yarmouk Teaching Hospital. Primary bacterial identification cultured on differential selective media and biochemical tests were done. The Vitek2 compact system (Biomerieux, France...

  4. Kombucha tea fermentation: Microbial and biochemical dynamics.

    Science.gov (United States)

    Chakravorty, Somnath; Bhattacharya, Semantee; Chatzinotas, Antonis; Chakraborty, Writachit; Bhattacharya, Debanjana; Gachhui, Ratan

    2016-03-02

    Kombucha tea, a non-alcoholic beverage, is acquiring significant interest due to its claimed beneficial properties. The microbial community of Kombucha tea consists of bacteria and yeast which thrive in two mutually non-exclusive compartments: the soup or the beverage and the biofilm floating on it. The microbial community and the biochemical properties of the beverage have so far mostly been described in separate studies. This, however, may prevent understanding the causal links between the microbial communities and the beneficial properties of Kombucha tea. Moreover, an extensive study into the microbial and biochemical dynamics has also been missing. In this study, we thus explored the structure and dynamics of the microbial community along with the biochemical properties of Kombucha tea at different time points up to 21 days of fermentation. We hypothesized that several biochemical properties will change during the course of fermentation along with the shifts in the yeast and bacterial communities. The yeast community of the biofilm did not show much variation over time and was dominated by Candida sp. (73.5-83%). The soup however, showed a significant shift in dominance from Candida sp. to Lachancea sp. on the 7th day of fermentation. This is the first report showing Candida as the most dominating yeast genus during Kombucha fermentation. Komagateibacter was identified as the single largest bacterial genus present in both the biofilm and the soup (~50%). The bacterial diversity was higher in the soup than in the biofilm with a peak on the seventh day of fermentation. The biochemical properties changed with the progression of the fermentation, i.e., beneficial properties of the beverage such as the radical scavenging ability increased significantly with a maximum increase at day 7. We further observed a significantly higher D-saccharic acid-1,4-lactone content and caffeine degradation property compared to previously described Kombucha tea fermentations. Our

  5. The pseudomonas quinolone signal (PQS balances life and death in Pseudomonas aeruginosa populations.

    Directory of Open Access Journals (Sweden)

    Susanne Häussler

    Full Text Available When environmental conditions deteriorate and become inhospitable, generic survival strategies for populations of bacteria may be to enter a dormant state that slows down metabolism, to develop a general tolerance to hostile parameters that characterize the habitat, and to impose a regime to eliminate damaged members. Here, we provide evidence that the pseudomonas quinolone signal (PQS mediates induction of all of these phenotypes. For individual cells, PQS, an interbacterial signaling molecule of Pseudomonas aeruginosa, has both deleterious and beneficial activities: on the one hand, it acts as a pro-oxidant and sensitizes the bacteria towards oxidative and other stresses and, on the other, it efficiently induces a protective anti-oxidative stress response. We propose that this dual function fragments populations into less and more stress tolerant members which respond differentially to developing stresses in deteriorating habitats. This suggests that a little poison may be generically beneficial to populations, in promoting survival of the fittest, and in contributing to bacterial multi-cellular behavior. It further identifies PQS as an essential mediator of the shaping of the population structure of Pseudomonas and of its response to and survival in hostile environmental conditions.

  6. Pseudomonas aeruginosa Biofilms

    DEFF Research Database (Denmark)

    Alhede, Maria; Bjarnsholt, Thomas; Givskov, Michael

    2014-01-01

    The opportunistic gram-negative bacterium Pseudomonas aeruginosa is implicated in many chronic infections and is readily isolated from chronic wounds, medical devices, and the lungs of cystic fibrosis patients. P. aeruginosa is believed to persist in the host organism due to its capacity to form...... biofilms, which protect the aggregated, biopolymer-embedded bacteria from the detrimental actions of antibiotic treatments and host immunity. A key component in the protection against innate immunity is rhamnolipid, which is a quorum sensing (QS)-regulated virulence factor. QS is a cell-to-cell signaling...

  7. The microbial diversity of traditional spontaneously fermented lambic beer.

    Directory of Open Access Journals (Sweden)

    Freek Spitaels

    Full Text Available Lambic sour beers are the products of a spontaneous fermentation that lasts for one to three years before bottling. The present study determined the microbiota involved in the fermentation of lambic beers by sampling two fermentation batches during two years in the most traditional lambic brewery of Belgium, using culture-dependent and culture-independent methods. From 14 samples per fermentation, over 2000 bacterial and yeast isolates were obtained and identified. Although minor variations in the microbiota between casks and batches and a considerable species diversity were found, a characteristic microbial succession was identified. This succession started with a dominance of Enterobacteriaceae in the first month, which were replaced at 2 months by Pediococcus damnosus and Saccharomyces spp., the latter being replaced by Dekkera bruxellensis at 6 months fermentation duration.

  8. The microbial diversity of traditional spontaneously fermented lambic beer.

    Science.gov (United States)

    Spitaels, Freek; Wieme, Anneleen D; Janssens, Maarten; Aerts, Maarten; Daniel, Heide-Marie; Van Landschoot, Anita; De Vuyst, Luc; Vandamme, Peter

    2014-01-01

    Lambic sour beers are the products of a spontaneous fermentation that lasts for one to three years before bottling. The present study determined the microbiota involved in the fermentation of lambic beers by sampling two fermentation batches during two years in the most traditional lambic brewery of Belgium, using culture-dependent and culture-independent methods. From 14 samples per fermentation, over 2000 bacterial and yeast isolates were obtained and identified. Although minor variations in the microbiota between casks and batches and a considerable species diversity were found, a characteristic microbial succession was identified. This succession started with a dominance of Enterobacteriaceae in the first month, which were replaced at 2 months by Pediococcus damnosus and Saccharomyces spp., the latter being replaced by Dekkera bruxellensis at 6 months fermentation duration.

  9. Wine fermentation microbiome: a landscape from different Portuguese wine appellations

    Directory of Open Access Journals (Sweden)

    Cátia ePinto

    2015-09-01

    Full Text Available Grapes and wine musts harbour a complex microbiome, which plays a crucial role in wine fermentation as it impacts on wine flavour and, consequently, on its final quality and value. Unveiling the microbiome and its dynamics, and understanding the ecological factors that explain such biodiversity, has been a challenge to oenology. In this work, we tackle this using a metagenomics approach to describe the natural microbial communities, both fungal and bacterial microorganisms, associated with spontaneous wine fermentations. For this, the wine microbiome, from six Portuguese wine appellations, was fully characterized as regards to three stages of fermentation – Initial Must (IM, and Start and End of alcoholic fermentation (SF and EF, respectively.The wine fermentation process revealed a higher impact on fungal populations when compared with bacterial communities, and the fermentation evolution clearly caused a loss of the environmental microorganisms. Furthermore, significant differences (p<0.05 were found in the fungal populations between IM, SF and EF, and in the bacterial population between MI and SF. Fungal communities were characterized by either the presence of environmental microorganisms and phytopathogens in the initial musts, or yeasts associated with alcoholic fermentations in wine must samples as Saccharomyces and non-Saccharomyces yeasts (as Lachancea, Metschnikowia, Hanseniaspora, Hyphopichia, Sporothrix, Candida and Schizosaccharomyces. Among bacterial communities, the most abundant family was Enterobacteriaceae; though families of species associated with the production of lactic acid (Lactobacillaceae, Leuconostocaceae and acetic acid (Acetobacteriaceae were also detected. Interestingly, a biogeographical correlation for both fungal and bacterial communities was identified between wine appellations at IM suggesting that each wine region contains specific and embedded microbial communities which may contribute to the uniqueness of

  10. Hexadecane degradation by bacterial strains isolated from ...

    African Journals Online (AJOL)

    A study was undertaken to detect and monitor the degradation of hexadecane by three potential degrading bacteria (Pseudomonas putida, Rhodococcus erythroplolis and Bacillus thermoleovorans) isolated from contaminated soils in Riyadh, Saudi Arabia. The extraction of the bacterial populations from these polluted soils ...

  11. Efficient utilization of crude glycerol as fermentation substrate in the synthesis of poly(3-hydroxybutyrate) biopolymers

    Science.gov (United States)

    One refined and 2 crude glycerol samples were utilized to produce poly(3-hydroxybutyrate) (PHB) by Pseudomonas oleovorans NRRL B-14682. Fermentation conditions were determined to efficiently utilize glycerol while maintaining PHB yields. A batch culture protocol including 1% glycerol and an aerati...

  12. characterisation of bacterial isolates from patients wounds and ...

    African Journals Online (AJOL)

    2013-12-12

    Dec 12, 2013 ... CHARACTERISATION OF BACTERIAL ISOLATES FROM PATIENTS WOUNDS AND ENVIRONMENTAL FACTORS. PREDICTIVE OF POST-SURGICAL .... as: mannitol salt agar (MSA) tryptone soy agar (TSA) supplemented with nystatin, blood agar ... by sugar fermentation (7). Gram negative rods were.

  13. Effect of Selected Azotobacter Bacterial Strains on the Enrichment of ...

    African Journals Online (AJOL)

    Effect of Selected Azotobacter Bacterial Strains on the Enrichment of Cassava Waste during Sold State Fermentation. ... The effect of three different strains of Azotobacter bacteria in solid substrate fermentation on cassava waste was evaluated. The substrate was incubated at 300c for 10 days inoculation with the ...

  14. Residual antibiotics disrupt meat fermentation and increase risk of infection.

    Science.gov (United States)

    Kjeldgaard, Jette; Cohn, Marianne T; Casey, Pat G; Hill, Colin; Ingmer, Hanne

    2012-01-01

    Fermented sausages, although presumed safe for consumption, sometimes cause serious bacterial infections in humans that may be deadly. Not much is known about why and when this is the case. We tested the hypothesis that residual veterinary antibiotics in meat can disrupt the fermentation process, giving pathogenic bacteria a chance to survive and multiply. We found that six commercially available starter cultures were susceptible to commonly used antibiotics, namely, oxytetracycline, penicillin, and erythromycin. In meat, statutorily tolerable levels of oxytetracycline and erythromycin inhibited fermentation performance of three and five of the six starter cultures, respectively. In model sausages, the disruption of meat fermentation enhanced survival of the pathogens Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium compared to successful fermentations. Our work reveals an overlooked risk associated with the presence of veterinary drugs in meat. Antibiotics have for a long time been used as growth promoters in farm animals, and while they are banned as such in Europe, their clinical use in farm animals still accounts for the majority of consumption. Here, we examined how acceptable levels of antibiotics in meat influence fermentation. Our results show that commonly used bacterial starter cultures are sensitive to residual antibiotics at or near statutorily tolerable levels, and as a result, processed sausages may indeed contain high levels of pathogens. Our findings provide a possible explanation for outbreaks and disease cases associated with consumption of fermented sausages and offer yet another argument for limiting the use of antimicrobials in farm animals.

  15. Management of soybean oil refinery wastes through recycling them for producing biosurfactant using Pseudomonas aeruginosa MR01.

    Science.gov (United States)

    Partovi, Maryam; Lotfabad, Tayebe Bagheri; Roostaazad, Reza; Bahmaei, Manochehr; Tayyebi, Shokoufe

    2013-06-01

    Biosurfactant production through a fermentation process involving the biodegradation of soybean oil refining wastes was studied. Pseudomonas aeruginosa MR01 was able to produce extracellular biosurfactant when it was cultured in three soybean oil refinement wastes; acid oil, deodorizer distillate and soapstock, at different carbon to nitrogen ratios. Subsequent fermentation kinetics in the three types of waste culture were also investigated and compared with kinetic behavior in soybean oil medium. Biodegradation of wastes, biosurfactant production, biomass growth, nitrate consumption and the number of colony forming units were detected in four proposed media, at specified time intervals. Unexpectedly, wastes could stimulate the biodegradation activity of MR01 bacterial cells and thus biosurfactant synthesis beyond that of the refined soybean oil. This is evident from higher yields of biodegradation and production, as revealed in the waste cultures (Ydeg|(Soybean oil) = 53.9 % YP/S|(Soybean oil) = 0.31 g g(-1), respectively). Although production yields were approximately the same in the three waste cultures (YP/S|(wastes) =/~ 0.5 g g(-1)), microbial activity resulted in higher yields of biodegradation (96.5 ± 1.13 %), maximum specific growth rate (μ max = 0.26 ± 0.02 h(-1)), and biosurfactant purity (89.6 %) with a productivity of 14.55 ± 1.10 g l(-1), during the bioconversion of soapstock into biosurfactant. Consequently, applying soybean oil soapstock as a substrate for the production of biosurfactant with commercial value has the potential to provide a combination of economical production with environmental protection through the biosynthesis of an environmentally friendly (green) compound and reduction of waste load entering the environment. Moreover, this work inferred spectrophotometry as an easy method to detect rhamnolipids in the biosurfactant products.

  16. Potent Antibacterial Antisense Peptide-Peptide Nucleic Acid Conjugates Against Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Ghosal, Anubrata; Nielsen, Peter E

    2012-01-01

    Pseudomonas aeruginosa is an opportunistic pathogen causing severe infections in hospital settings, especially with immune compromised patients, and the increasing prevalence of multidrug resistant strains urges search for new drugs with novel mechanisms of action. In this study we introduce...... antisense peptide-peptide nucleic acid (PNA) conjugates as antibacterial agents against P. aeruginosa. We have designed and optimized antisense peptide-PNA conjugates targeting the translation initiation region of the ftsZ gene (an essential bacterial gene involved in cell division) or the acpP gene (an...... significantly reduced bacterial survival. These results open the possibility of development of antisense antibacterials for treatment of Pseudomonas infections....

  17. First report of mixed infection by Pseudomonas syringae pathovars garcae and tabaci on coffee plantations

    OpenAIRE

    Lucas Mateus Rivero Rodrigues; Gustavo Hiroshi Sera; Oliveiro Guerreiro Filho; Luis Otavio Saggion Beriam; Irene Maria Gatti de Almeida

    2017-01-01

    ABSTRACT The bacterial-halo-blight (Pseudomonas syringae pv. garcae) is disseminated by the main coffee areas in the producing states of Brazil. On the other hand, the disease bacterial-leaf-spot (Pseudomonas syringae pv. tabaci) was reported only once in coffee seedlings in a sample collected in the State of São Paulo. In mid-2015, samples of coffee leaves with symptoms of foliar lesions surrounded by yellow halo, were collected in coffee plantations in the State of Paraná and fluorescent ba...

  18. Preliminary study on hazards and critical control points of kokoro, a Nigerian indigenous fermented maize snack.

    Science.gov (United States)

    Oranusi, S; Dahunsi, S O

    2015-01-01

    The microbial and proximate composition of an indigenous snack from fermented maize was investigated. Critical control points of milling the raw materials, fermentation pH, processing temperature and time intervals during holdings in processing and storage were evaluated with a view to optimizing the product. The mean total aerobic plate count (TAPC) log10 values for samples of the finished products range from 2.07 ± 0.50 to 4.36 ± 0.10 cfu/g. Mean fungi count log10 was 2.00 ± 0.00 to 3.50 ± 0.50 while mean coliform count 1.04 ± 0.10 log10 cfu/g was detected in one of the sales outlets investigated. Bacterial and fungal species were isolated belonging to the genera Aspergillus, Rhizopus, Penicillium, Fusarium, Cephalosporium, Alternaria, Bacillus, Klebsiella, Staphylococcus, Lactobacillus, Pseudomonas, Proteus and Enterobacter. The moisture content of the samples ranged from 3.41 to 6.75%; fat content was 19.68 to 32.59%; fiber content was 1.84 to 2.78% while protein ranged from 6.76 to 9.23%. The ash and carbohydrate contents ranged from 1.97 to 2.31% and 49.21 to 61.96%, respectively. Based on the specifications by International Commission for Microbiological Specification for Foods (ICMSF), the TAPC counts of the finished products remained at low levels. However, presence of coliforms could prejudice the hygienic quality of these types of products hence, the need for quality control.

  19. Korean traditional fermented fish products: jeotgal

    Directory of Open Access Journals (Sweden)

    Ok Kyung Koo

    2016-06-01

    Full Text Available Jeotgal (醢 is a traditional Korean fermented food with thousands years of history with kimchi and other jang (fermented soybean products, 醬. The history was proved by research from historical literature and antique architecture. Jeotgal was developed along with jang (豆醬, fish jang (魚醬, meat jang (肉醬 as a part of jang (醬 up to the Chosun Dynasty and it was always offered during the ancestral rites or ceremonies. According to antique documents written by women, jeotgal had been used as seasonings or condiments that were popular especially for women rather than as food served for ancestral rites. In Southeast Asia and other countries, jeotgal uses varieties of fish and seafoods to provide rich and varied flavors, and thanks to the next generation sequencing technology, we can identify microorganisms that are involved in the fermentation process. Major microorganisms in jeotgal are Bacillus, Brevibacterium, Micrococcus, Pediococcus, Pseudomonas, Lactobacillus, Leuconostoc, and Halobacterium. Recently, much research on various health function of jeotgal has been conducted, reflecting increasing interest in the safety and the functionality of jeotgal. Many reports on functionalities of jeotgal such as supplying essential amino acids, and having antioxidant and antitumorgenic have been published recently. Because of the diverse flavor, types, and their function, jeotgal is expected to continue to develop as an important seasoning in the world sauce market.

  20. Kombucha fermentation and its antimicrobial activity.

    Science.gov (United States)

    Sreeramulu, G; Zhu, Y; Knol, W

    2000-06-01

    Kombucha was prepared in a tea broth (0.5% w/v) supplemented with sucrose (10% w/v) by using a commercially available starter culture. The pH decreased steadily from 5 to 2.5 during the fermentation while the weight of the "tea fungus" and the OD of the tea broth increased through 4 days of the fermentation and remained fairly constant thereafter. The counts of acetic acid-producing bacteria and yeasts in the broth increased up to 4 days of fermentation and decreased afterward. The antimicrobial activity of Kombucha was investigated against a number of pathogenic microorganisms. Staphylococcus aureus, Shigella sonnei, Escherichia coli, Aeromonas hydrophila, Yersinia enterolitica, Pseudomonas aeruginosa, Enterobacter cloacae, Staphylococcus epidermis, Campylobacter jejuni, Salmonella enteritidis, Salmonella typhimurium, Bacillus cereus, Helicobacterpylori, and Listeria monocytogenes were found to be sensitive to Kombucha. According to the literature on Kombucha, acetic acid is considered to be responsible for the inhibitory effect toward a number of microbes tested, and this is also valid in the present study. However, in this study, Kombucha proved to exert antimicrobial activities against E. coli, Sh. sonnei, Sal. typhimurium, Sal. enteritidis, and Cm. jejuni, even at neutral pH and after thermal denaturation. This finding suggests the presence of antimicrobial compounds other than acetic acid and large proteins in Kombucha.

  1. Abundance and diversity of culturable Pseudomonas constitute sensitive indicators for adverse long-term copper impacts in soil

    DEFF Research Database (Denmark)

    Thorsen, Maja Kristine; Brandt, Kristian Koefoed; Nybroe, Ole

    2013-01-01

    heterotrophic bacteria. This indicates that the Pseudomonas population is not resilient towards copper stress and that culturable Pseudomonas spp. comprise sensitive bio-indicators of adverse copper impacts in contaminated soils. Further this study shows that copper exposure decreases bacterial diversity...

  2. Wave-like distribution patterns of Gfp-marked Pseudomonas fluorescens along roots of wheat plants grown in two soils

    NARCIS (Netherlands)

    Bruggen, van A.H.C.; Semenov, A.M.; Zelenev, V.V.; Semenov, A.V.; Raaijmakers, J.M.; Sayler, R.J.; Vos, de O.J.

    2008-01-01

    Culturable rhizosphere bacterial communities had been shown to exhibit wave-like distribution patterns along wheat roots. In the current work we show, for the first time, significant wave-like oscillations of an individual bacterial strain, the biocontrol agent Pseudomonas fluorescens 32 marked with

  3. Green Nail Syndrome (Pseudomonas aeruginosa Nail Infection: Two Cases Successfully Treated with Topical Nadifloxacin, an Acne Medication

    Directory of Open Access Journals (Sweden)

    Simon Müller

    2014-07-01

    Full Text Available Green nail syndrome (GNS caused by Pseudomonas aeruginosa is the most common bacterial nail infection. The treatment of GNS is challenging in many cases and recommendations based on clinical trials are lacking. We report two cases with GNS successfully treated with off-label use of topical nadifloxacin, a fluoroquinolone approved for acne and bacterial skin infections in some countries.

  4. Bacterial community associated with ensilage process of wilted guinea grass.

    Science.gov (United States)

    Parvin, S; Nishino, N

    2009-12-01

    To determine the effects of wilting, storage period and bacterial inoculant on the bacterial community and ensiling fermentation of guinea grass silage. Fermentation products, colony counts and denaturing gradient gel electrophoresis (DGGE) profiles were determined. There was more lactic acid than acetic acid in all silages, but the lactic acid to acetic acid ratio decreased with storage time. This shift from lactic to acetic acid was not prevented even with a combination of wilting and bacterial inoculant. The DGGE analyses suggest that facultatively heterofermentative lactic acid bacteria (Lactobacillus plantarum, Lactobacillus brevis and Lactobacillus pentosus) were involved in the shift to acetic acid fermentation. Lactic acid can dominate the fermentation in tropical grass silage with sufficient wilting prior to ensiling. Prolonged storage may lead to high levels of acetic acid without distinctive changes in the bacterial community. The bacterial community looks stable compared to fermentation products over the course of long storage periods in tropical grass silage. Acetic acid fermentation in tropical grass silage can be a result of the changes in bacterial metabolism rather than community structure.

  5. Targeting quorum sensing in Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Jakobsen, Tim Holm; Bjarnsholt, Thomas; Jensen, Peter Østrup

    2013-01-01

    Bacterial resistance to conventional antibiotics combined with an increasing acknowledgement of the role of biofilms in chronic infections has led to a growing interest in new antimicrobial strategies that target the biofilm mode of growth. In the aggregated biofilm mode, cell-to-cell communication...... systems involved in the process known as quorum sensing regulate coordinated expression of virulence with immune shielding mechanisms and antibiotic resistance. For two decades, the potential of interference with quorum sensing by small chemical compounds has been investigated with the aim of developing...... alternative antibacterial strategies. Here, we review state of the art research of quorum sensing inhibitors against the opportunistic human pathogen Pseudomonas aeruginosa, which is found in a number of biofilm-associated infections and identified as the predominant organism infecting the lungs of cystic...

  6. Bacterial Biodegradation of Crude Oil Using Local Isolates

    Directory of Open Access Journals (Sweden)

    Raed S. Al-Wasify

    2014-01-01

    Full Text Available An experimental study was undertaken to assess the efficiency of Pseudomonas aeruginosa, Bacillus subtilis, and Acinetobacter lwoffi isolated from petroleum contaminated water and soil samples to degrade crude oil, separately and in a mixed bacterial consortium. Capillary gas chromatography was used for testing the effect of those bacterial species on the biodegradation of crude oil. Individual bacterial cultures showed less growth and degradation than did the mixed bacterial consortium. At temperature 22°C, the mixed bacterial consortium degraded a maximum of 88.5% of Egyptian crude oil after 28 days of incubation. This was followed by 77.8% by Pseudomonas aeruginosa, 76.7% by Bacillus subtilis, and 74.3% by Acinetobacter lwoffi. The results demonstrated that the selected bacterial isolates could be effective in biodegradation of oil spills individually and showed better biodegradation abilities when they are used together in mixed consortium.

  7. Bacterial Biodegradation of Crude Oil Using Local Isolates.

    Science.gov (United States)

    Al-Wasify, Raed S; Hamed, Shimaa R

    2014-01-01

    An experimental study was undertaken to assess the efficiency of Pseudomonas aeruginosa, Bacillus subtilis, and Acinetobacter lwoffi isolated from petroleum contaminated water and soil samples to degrade crude oil, separately and in a mixed bacterial consortium. Capillary gas chromatography was used for testing the effect of those bacterial species on the biodegradation of crude oil. Individual bacterial cultures showed less growth and degradation than did the mixed bacterial consortium. At temperature 22°C, the mixed bacterial consortium degraded a maximum of 88.5% of Egyptian crude oil after 28 days of incubation. This was followed by 77.8% by Pseudomonas aeruginosa, 76.7% by Bacillus subtilis, and 74.3% by Acinetobacter lwoffi. The results demonstrated that the selected bacterial isolates could be effective in biodegradation of oil spills individually and showed better biodegradation abilities when they are used together in mixed consortium.

  8. Enhancing the digestibility of cowpea (Vigna unguiculata) by traditional processing and fermentation

    NARCIS (Netherlands)

    Madode, Y.E.; Nout, M.J.R.; Bakker, E.J.; Linnemann, A.R.; Hounhouigan, D.J.; Boekel, van M.A.J.S.

    2013-01-01

    Flatulence is an important drawback for the consumption of legumes. Therefore, the ability of traditional processing (dehulling, boiling, soaking) and fermentation (bacterial, fungal or yeast) of cowpeas to reduce flatulence was investigated. Raw and processed cowpeas were assessed for their

  9. Development of antioxidant activity in milk whey during fermentation with lactic acid bacteria

    National Research Council Canada - National Science Library

    Virtanen, T; Pihlanto, A; Akkanen, S; Korhonen, H

    2007-01-01

    ... system with a fluorescence method. Milk was fermented with 25 lactic acid bacterial (LAB) strains, and from these six strains, exhibiting the highest radical scavenging activity was selected for further investigation...

  10. Effects of atmospheric conditions on ice nucleation activity of Pseudomonas

    Directory of Open Access Journals (Sweden)

    C. Glaux

    2012-11-01

    Full Text Available Although ice nuclei from bacterial origin are known to be efficient at the highest temperatures known for ice catalysts, quantitative data are still needed to assess their role in cloud processes. Here we studied the effects of three typical cloud conditions (i acidic pH (ii NO2 and O3 exposure and (iii UV-A exposure on the ice nucleation activity (INA of four Pseudomonas strains. Three of the Pseudomonas syringae strains were isolated from cloud water and the phyllosphere and Pseudomonas fluorescens strain CGina-01 was isolated from Antarctic glacier ice melt. Among the three conditions tested, acidic pH caused the most significant effects on INA likely due to denaturation of the ice nucleation protein complex. Exposure to NO2 and O3 gases had no significant or only weak effects on the INA of two P. syringae strains whereas the INA of P. fluorescens CGina-01 was significantly affected. The INA of the third P. syringae strain showed variable responses to NO2 and O3 exposure. These differences in the INA of different Pseudomonas suggest that the response to atmospheric conditions could be strain-specific. After UV-A exposure, a substantial loss of viability of all four strains was observed whereas their INA decreased only slightly. This corroborates the notion that under certain conditions dead bacterial cells can maintain their INA. Overall, the negative effects of the three environmental factors on INA were more significant at the warmer temperatures. Our results suggest that in clouds where temperatures are near 0 °C, the importance of bacterial ice nucleation in precipitation processes could be reduced by some environmental factors.

  11. Passage of Salmonella through the crop and gizzard of broiler chickens fed with fermented liquid feed.

    NARCIS (Netherlands)

    Heres, L.; Wagenaar, J.A.; Knapen, van F.; Urlings, B.A.P.

    2003-01-01

    In vivo experiments were conducted in order to investigate the passage and bacterial reduction of Salmonella in the crop and gizzard of chickens when fed two different feeds. The chickens were fed dry conventional feed and fermented liquid feed. The fermented feed contains a relatively high

  12. Bacteriophage endolysins expressed in yeast kill strains of Lactobacillus that contaminate fermentations

    Science.gov (United States)

    One of the challenges facing the fuel ethanol industry is the management of bacterial contamination during fermentation. Species of Lactobacillus are the predominant contaminants that reduce ethanol yields and cause “stuck” fermentations, decreasing the profitability of biofuel production with expen...

  13. Pseudomonas aeruginosa biofilm infections

    DEFF Research Database (Denmark)

    Tolker-Nielsen, Tim

    2014-01-01

    Bacteria in natural, industrial and clinical settings predominantly live in biofilms, i.e., sessile structured microbial communities encased in self-produced extracellular matrix material. One of the most important characteristics of microbial biofilms is that the resident bacteria display...... a remarkable increased tolerance toward antimicrobial attack. Biofilms formed by opportunistic pathogenic bacteria are involved in devastating persistent medical device-associated infections, and chronic infections in individuals who are immune-compromised or otherwise impaired in the host defense. Because...... the use of conventional antimicrobial compounds in many cases cannot eradicate biofilms, there is an urgent need to develop alternative measures to combat biofilm infections. The present review is focussed on the important opportunistic pathogen and biofilm model organism Pseudomonas aeruginosa. Initially...

  14. The microbiology of Ghanaian cocoa fermentations analysed using culture-dependent and culture-independent methods.

    Science.gov (United States)

    Nielsen, D S; Teniola, O D; Ban-Koffi, L; Owusu, M; Andersson, T S; Holzapfel, W H

    2007-03-10

    Export of cocoa beans is of great economic importance in Ghana and several other tropical countries. Raw cocoa has an astringent unpleasant taste and a spontaneous fermentation is the first step in a process leading to cocoa beans with the characteristic cocoa flavour and taste. The microbiology of Ghanaian cocoa fermentations was investigated using culture-dependent and culture-independent methods. Samples were collected at 12 hour intervals during 96-144 hour tray and traditional heap fermentations. Yeast, Lactic Acid Bacteria (LAB), Acetic Acid Bacteria (AAB) and Bacillus spp. were enumerated on suitable substrates and identified using phenotypic and molecular methods. The yeast and bacterial micro-populations involved in the cocoa fermentation were further investigated using the culture-independent method Denaturing Gradient Gel Electrophopresis (DGGE). A microbiological succession was observed during the fermentations. At the onset of fermentation yeasts were the dominating microorganisms. Lactic Acid Bacteria became dominant after 12-24 h of fermentation and remained predominant throughout the fermentations with AAB reaching high counts in the mid phase of fermentation. Bacillus spp. were only detected during heap fermentations where they reached high numbers during the later stages of fermentation. Hanseniaspora guilliermondii was the predominant yeast during the initial phase and Pichia membranifaciens during the later phases of fermentation. A number of other yeast species including three putatively undescribed species were isolated during the fermentations. Lactobacillus fermentum was the dominant LAB in most samples. Several other LAB including Lactobacillus plantarum, Leuconostoc pseudomesenteroides, Leuconostoc pseudoficulneum, Pediocococcus acidilactici and a putatively undescribed LAB species were detected during the fermentations. Acetobacter syzygii, Acetobacter pasteurianus and Acetobacter tropicalis were the predominant AAB in all investigated

  15. Desulfurization activity evaluation of native strains of pseudomonas spp. in the presence of hydrocarbon

    OpenAIRE

    Alméciga-Díaz, Carlos Javier; Sánchez Medina, Óscar Fernando; Silva Gómez, Edelberto

    2007-01-01

    The main difficulty with fossil fuel combustión lies in sulphur and nitrogen becoming converted to their respective oxides, forming part of the acid rain which deteriorates the environment and infrastructure. Removing sulphur from organo-sulfur compounds by using micro-organisms has become an alternative to hydrodesulphurisation (HDS). Twenty-three Pseudomonas spp. native strains' desulphurisation activity on dibenzothiophene (DBT) was evaluated by using a fermentation system having equal pro...

  16. Study on fermentation kinetics and extraction process of rhamnolipid production by papermaking wastewater

    Science.gov (United States)

    Yu, Keer

    2018-01-01

    Paper mill wastewater (PMW) is the outlet water generated during pulp and papermaking process in the paper industry. Fermentation by wastewater can lower the cost of production as well as alleviate the pressure of wastewater treatment. Rhamnolipids find broad placations as natural surfactants. This paper studied the rhamnolipids fermentation by employing Pseudomonas aeruginosa isolated by the laboratory, and determined to use wastewater which filtered by medium speed filter paper and strain Z2, the culture conditions were optimized, based on the flask shaking fermentation. On the basis of 5L tank fermentation, batch fermentation was carried out, the yield of fermentation reached 7.067g/L and the fermentation kinetics model of cell growth, product formation and substrate consumption was established by using origin software, and the fermentation process could be simulated well. And studied on the extraction process of rhamnolipids, through fermentation dynamic equation analysis can predict the in fill material yield can be further improved. Research on the extraction process of rhamnolipid simplifies the operation of extraction, and lays the foundation for the industrial extraction.

  17. Final screening assessment for Pseudomonas putida ATCC 12633, Pseudomonas putida ATCC 31483, Pseudomonas putida ATCC 31800, Pseudomonas putida ATCC 700369

    National Research Council Canada - National Science Library

    2017-01-01

    "Pursuant to paragraph 74(b) of the Canadian Environmental Protection Act, 1999 (CEPA), the Minister of the Environment and the Minister of Health have conducted a screening assessment on four strains of Pseudomonas putida...

  18. Biosynthesis of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) by bacterial community from propylene oxide saponification wastewater residual sludge.

    Science.gov (United States)

    Wang, Yiwei; Zhu, Ying; Gu, Pengfei; Li, Yumei; Fan, Xiangyu; Song, Dongxue; Ji, Yan; Li, Qiang

    2017-05-01

    The saponification wastewater from the process of propylene oxide (PO) production is contaminated with high chemical oxygen demand (COD) and chlorine contents. Although the activated sludge process could treat the PO saponification wastewater effectively, the residual sludge was difficult to be disposed properly. In this research, microbes in PO saponification wastewater residual sludge were acclimated to produce poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) from volatile fatty acids. Through Miseq Illumina highthroughput sequencing, the bacterial community discrepancy between the original and the acclimated sludge samples were analyzed. The proportions of Bacillus, Acinetobacter, Brevundimonas and Pseudomonas, the potential PHBV-producers in the residual sludge, were all obviously increased. In the batch fermentation, the production of PHBV could achieve 4.262g/L at 300min, with the content increased from 0.04% to 23.67% of mixed liquor suspended solid (MLSS) in the acclimated sludge, and the COD of the PO saponification wastewater was also decreased in the fermentation. This work would provide an effective solution for the utilization of PO saponification wastewater residual sludge. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Chronic Pseudomonas aeruginosa cervical osteomyelitis

    Directory of Open Access Journals (Sweden)

    Sujeet Kumar Meher

    2016-01-01

    Full Text Available Pseudomonas aeruginosa is a rare cause of osteomyelitis of the cervical spine and is usually seen in the background of intravenous drug use and immunocompromised state. Very few cases of osteomyelitis of the cervical spine caused by pseudomonas aeruginosa have been reported in otherwise healthy patients. This is a case presentation of a young female, who in the absence of known risk factors for cervical osteomyelitis presented with progressively worsening neurological signs and symptoms.

  20. Biodegradation of crude oil by individual bacterial strains and a mixed bacterial consortium.

    Science.gov (United States)

    Santisi, Santina; Cappello, Simone; Catalfamo, Maurizio; Mancini, Giuseppe; Hassanshahian, Mehdi; Genovese, Lucrezia; Giuliano, Laura; Yakimov, Michail M

    2015-06-01

    Three bacterial isolates identified as Alcanivorax borkumensis SK2, Rhodococcus erythropolis HS4 and Pseudomonas stutzeri SDM, based on 16S rRNA gene sequences, were isolated from crude oil enrichments of natural seawater. Single strains and four bacterial consortia designed by mixing the single bacterial cultures respectively in the following ratios: (Alcanivorax: Pseudomonas, 1:1), (Alcanivorax: Rhodococcus, 1:1), (Pseudomonas: Rhodococcus, 1:1), and (Alcanivorax: Pseudomonas: Rhodococcus, 1:1:1), were analyzed in order to evaluate their oil degrading capability. All experiments were carried out in microcosms systems containing seawater (with and without addition of inorganic nutrients) and crude oil (unique carbon source). Measures of total and live bacterial abundance, Card-FISH and quali-, quantitative analysis of hydrocarbons (GC-FID) were carried out in order to elucidate the co-operative action of mixed microbial populations in the process of biodegradation of crude oil. All data obtained confirmed the fundamental role of bacteria belonging to Alcanivorax genus in the degradation of linear hydrocarbons in oil polluted environments.

  1. Biodegradation of crude oil by individual bacterial strains and a mixed bacterial consortium

    Directory of Open Access Journals (Sweden)

    Santina Santisi

    2015-06-01

    Full Text Available Three bacterial isolates identified as Alcanivorax borkumensis SK2, Rhodococcus erythropolis HS4 and Pseudomonas stutzeri SDM, based on 16S rRNA gene sequences, were isolated from crude oil enrichments of natural seawater. Single strains and four bacterial consortia designed by mixing the single bacterial cultures respectively in the following ratios: (Alcanivorax: Pseudomonas, 1:1, (Alcanivorax: Rhodococcus, 1:1, (Pseudomonas: Rhodococcus, 1:1, and (Alcanivorax: Pseudomonas: Rhodococcus, 1:1:1, were analyzed in order to evaluate their oil degrading capability. All experiments were carried out in microcosms systems containing seawater (with and without addition of inorganic nutrients and crude oil (unique carbon source. Measures of total and live bacterial abundance, Card-FISH and quali-, quantitative analysis of hydrocarbons (GC-FID were carried out in order to elucidate the co-operative action of mixed microbial populations in the process of biodegradation of crude oil. All data obtained confirmed the fundamental role of bacteria belonging to Alcanivorax genus in the degradation of linear hydrocarbons in oil polluted environments.

  2. Asian fungal fermented food

    NARCIS (Netherlands)

    Nout, M.J.R.; Aidoo, K.E.

    2010-01-01

    In Asian countries, there is a long history of fermentation of foods and beverages. Diverse micro-organisms, including bacteria, yeasts and moulds, are used as starters, and a wide range of ingredients can be made into fermented foods. The main raw materials include cereals, leguminous seeds,

  3. Food Technologies: Fermentation

    NARCIS (Netherlands)

    Nout, M.J.R.

    2014-01-01

    Fermentation refers to the use of microorganisms to achieve desirable food properties in the fermented food or beverage. Although the word ‘fermentation’ indicates ‘anaerobic metabolism,’ it is also used in a broader sense to indicate all anaerobic and aerobic microbiological and biochemical

  4. Bacterial meningitis

    NARCIS (Netherlands)

    Roos, Karen L.; van de Beek, Diederik

    2010-01-01

    Bacterial meningitis is a neurological emergency. Empiric antimicrobial and adjunctive therapy should be initiated as soon as a single set of blood cultures has been obtained. Clinical signs suggestive of bacterial meningitis include fever, headache, meningismus, vomiting, photophobia, and an

  5. Anaerobic production of alginate by Pseudomonas aeruginosa: alginate restricts diffusion of oxygen.

    OpenAIRE

    Hassett, D J

    1996-01-01

    Pseudomonas aeruginosa produced alginate and elevated algD (encoding GDPmannose 6-dehydrogenase) transcription under strict anaerobic conditions, especially when using nitrate as a terminal electron acceptor. Purified alginate added to bacterial suspensions caused a decrease in growth, suggesting that alginate contributes to oxygen limitation for the organism and likely for patients afflicted with the inherited autosomal disease cystic fibrosis.

  6. Force microscopic and thermodynamic analysis of the adhesion between Pseudomonas aeruginosa and Candida albicans

    NARCIS (Netherlands)

    Ovchinnikova, Ekaterina S.; Krom, Bastiaan P.; van der Mei, Henny C.; Busscher, Henk J.

    2012-01-01

    Pseudomonas aeruginosa expresses a plethora of virulence factors and many species have developed warning systems to detect and evade P. aeruginosa. Candida albicans detects P. aeruginosa by sensing the secreted bacterial quorum sensing molecule 3OC(12)HSL and responds by reverting to the yeast

  7. Genome sequence of the mycorrhizal helper bacterium Pseudomonas fluorescens BBc6R8

    Energy Technology Data Exchange (ETDEWEB)

    Deveau, Aurelie [French National Insitute for Agricultural Research (INRA); Grob, Harald [University of Bonn, Germany; Morin, Emmanuelle [INRA, Nancy, France; Karpinets, Tatiana V [ORNL; Utturkar, Sagar M [ORNL; Mehnaz, Samina [University of the Punjab, Pakistan; Kurz, Sven [University of Bonn, Germany; Martin, Francis [INRA, Nancy, France; Frey-Klett, Pascale [INRA, Nancy, France; Labbe, Jessy L [ORNL

    2014-01-01

    We report the draft genome sequence of the mycorrhiza helper bacterium Pseudomonas fluorescens strain BBc6R8 . Several traits which could be involved in the mycorrhiza helper ability of the bacterial strain such as multiple secretion systems, auxin metabolism and phosphate mobilization were evidenced in the genome.

  8. Force microscopic and thermodynamic analysis of the adhesion between Pseudomonas aeruginosa and Candida albicans

    NARCIS (Netherlands)

    Ovchinnikova, E.S.; Krom, B.P.; van der Mei, H.C.; Busscher, H.J.

    2012-01-01

    Pseudomonas aeruginosa expresses a plethora of virulence factors and many species have developed warning systems to detect and evade P. aeruginosa. Candida albicans detects P. aeruginosa by sensing the secreted bacterial quorum sensing molecule 3OC12HSL and responds by reverting to the yeast

  9. Cyclic lipopeptide production by plant-associated Pseudomonas spp.: diversity, activity, biosynthesis, and regulation

    NARCIS (Netherlands)

    Raaijmakers, J.M.; Bruijn, de I.; Kock, de M.J.D.

    2006-01-01

    Cyclic lipopeptides (CLPs) are versatile molecules produced by a variety of bacterial genera, including plant-associated Pseudomonas spp. CLPs are composed of a fatty acid tail linked to a short oligopeptide, which is cyclized to form a lactone ring between two amino acids in the peptide chain. CLPs

  10. Pseudomonas syringae evades host Immunity by degrading flagellin monomers with alkaline protease AprA

    NARCIS (Netherlands)

    Pel, M.J.C.; Van Dijken, A.J.H.; Bardoel, B.W.; Seidl, M.F; Van der Ent, S.; Van Strijp, J.A.G.

    2014-01-01

    Bacterial flagellin molecules are strong inducers of innate immune responses in both mammals and plants. The opportunistic pathogen Pseudomonas aeruginosa secretes an alkaline protease called AprA that degrades flagellin monomers. Here, we show that AprA is widespread among a wide variety of

  11. Pseudomonas syringae evades host immunity by degrading flagellin monomers with alkaline protease AprA

    NARCIS (Netherlands)

    Pel, Michiel J C; van Dijken, Anja J H; Bardoel, Bart W; Seidl, Michael F; van der Ent, Sjoerd; van Strijp, Jos A G; Pieterse, Corné M J

    Bacterial flagellin molecules are strong inducers of innate immune responses in both mammals and plants. The opportunistic pathogen Pseudomonas aeruginosa secretes an alkaline protease called AprA that degrades flagellin monomers. Here, we show that AprA is widespread among a wide variety of

  12. Biosynthetic Origin of the Antibiotic Cyclocarbamate Brabantamide A (SB-253514) in Plant-Associated Pseudomonas

    NARCIS (Netherlands)

    Schmidt, Y.; Voort, van der M.; Crüsemann, M.; Piel, J.; Josten, M.; Sahl, H.G.; Miess, H.; Raaijmakers, J.M.; Gross, H.

    2014-01-01

    Within the framework of our genome-based program to discover new antibiotic lipopeptides from Pseudomonads, brabantamides A–C were isolated from plant-associated Pseudomonas sp. SH-C52. Brabantamides A–C displayed moderate to high in vitro activities against Gram-positive bacterial pathogens. Their

  13. Nonrandom distribution of Pseudomonas aeruginosa and Staphylococcus aureus in chronic wounds

    DEFF Research Database (Denmark)

    Fazli, Mustafa; Bjarnsholt, Thomas; Kirketerp-Møller, Klaus

    2009-01-01

    The spatial organization of Pseudomonas aeruginosa and Staphylococcus aureus in chronic wounds was investigated in the present study. Wound biopsy specimens were obtained from patients diagnosed as having chronic venous leg ulcers, and bacterial aggregates in these wounds were detected and located...

  14. Water flow induced transport of Pseudomonas fluorescens cells through soil columns as affected by inoculant treatment

    NARCIS (Netherlands)

    Hekman, W.E.; Heijnen, C.E.; Trevors, J.T.; Elsas, van J.D.

    1994-01-01

    Water flow induced transport of Pseudomonas fluorescens cells through soil columns was measured as affected by the inoculant treatment. Bacterial cells were introduced into the topsoil of columns, either encapsulated in alginate beads of different types or mixed with bentonite clay in concentrations

  15. Cell surface physico chemistry alters biofilm development of Pseudomonas aeruginosa lipopolysaccharide mutants

    NARCIS (Netherlands)

    Flemming, CA; Palmer, RJ; Arrage, AA; van der Mei, H.C.; White, DC

    1999-01-01

    The hydrophobic and electrostatic characteristics of bacterial cell surfaces were compared with attachment proclivity and biomass accumulation over time between wildtype Pseudomonas aeruginosa serotype O6 (possesses A and B band LPS), and three LPS-deficient mutants, vi;. A28 (A(+)B(-)), R5

  16. Whole cell fatty acid analysis as a tool for classification of phytopathogenic pseudomonas bacteria

    NARCIS (Netherlands)

    Janse, J.D.

    1992-01-01

    In this thesis some members of the plant pathogenic bacterial genus Pseudomonas have been studied. Conventional morphological, biochemical, physiological and pathogenitcity tests as well as a 'finger-print' technique, viz. automated whole cell fatty acid analysis, were

  17. Community-acquired bloodstream infection caused by Pseudomonas paucimobilis: case report and review of the literature.

    OpenAIRE

    Morrison, A J; Shulman, J. A

    1986-01-01

    Various sources of Pseudomonas paucimobilis bacterial infections have been documented. We report the third human case of bloodstream infection due to P. paucimobilis and review the literature in English regarding community-acquired and nosocomial infection due to this bacterium. Biochemical and genetic characteristics supporting the pathogenic potential of P. paucimobilis are presented, and the antibiotic susceptibility profile of the organism is summarized.

  18. Distribution and survival of Pseudomonas sp. on Italian ryegrass and Curly dock in Georgia

    Science.gov (United States)

    Yellow bud, caused by Pseudomonas sp. is an emerging bacterial disease of onion. Polymerase chain reaction (PCR) assay based on the coronafacate ligase (cfl) and HrpZ genes were used to detect initial suspected bacteria on weeds. Growth on an agar medium, ability to cause a hypersensitive response i...

  19. Draft Genome Sequence of the Rhizobacterium Pseudomonas chlororaphis PCL1601, Displaying Biocontrol against Soilborne Phytopathogens.

    Science.gov (United States)

    Vida, Carmen; de Vicente, Antonio; Cazorla, Francisco M

    2017-04-06

    In this study, we present the draft genome sequence of the bacterial strain Pseudomonas chlororaphis PCL1601. This bacterium was isolated from the rhizosphere of healthy avocado trees and displayed antagonistic and biological control activities against different soilborne phytopathogenic fungi and oomycetes. Copyright © 2017 Vida et al.

  20. Disulfide Bond-Containing Ajoene Analogues As Novel Quorum Sensing Inhibitors of Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Fong, July; Yuan, Mingjun; Jakobsen, Tim Holm

    2017-01-01

    Since its discovery 22 years ago, the bacterial cell-to-cell communication system, termed quorum sensing (QS), has shown potential as antipathogenic target. Previous studies reported that ajoene from garlic inhibits QS in opportunistic human pathogen Pseudomonas aeruginosa. In this study, screening...

  1. Influence of phenolic compounds of Kangra tea [Camellia sinensis (L) O Kuntze] on bacterial pathogens and indigenous bacterial probiotics of Western Himalayas.

    Science.gov (United States)

    Sourabh, Aditi; Kanwar, S S; Sud, R G; Ghabru, Arti; Sharma, O P

    2013-01-01

    Phenolic compounds of nutraceutical importance viz., catechins (C), (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epigallocatechin-3-gallate (EGCG) and (-)-epicatechin-3-gallate (ECG) were estimated in fresh green tea shoots of Camellia sinensis (L) O Kuntze cultivar. The total polyphenols and total catechins were in the range of 219.90 to 317.81 and 140.83 to 271.39 g/kg, respectively in monthly samples of tea. The values of C, EC, EGC, EGCG and ECG in tea powders as analyzed through high performance liquid chromatography (HPLC) were in the range of 1.560 to 3.661, 13.338 to 27.766, 26.515 to 39.597, 62.903 to 102.168 and 18.969 to 39.469 mg/g, respectively. Effect of tea extracts and standard flavanols against five pathogenic bacteria viz., Listeria monocytogenes (MTCC-839), Pseudomonas aeruginosa (MTCC-741), Bacillus cereus (MTCC-1272), Staphylococcus aureus (MTCC-96) and Escherichia coli (MTCC-443), and eleven indigenous potential bacterial probiotics belonging to genera Enterococcus, Bacillus and Lactobacillus spp. obtained from fermented foods of Western Himalayas, was investigated. EGCG, ECG and EGC exhibited antibacterial activity but, C and EC did not show this activity. Tea extracts having high concentrations of EGCG and ECG were more potent in antibacterial action against bacterial pathogens. Tea extracts and standard flavan-3-ols augmented viability of potential probiotics in an order of EGCG > EGC > ECG > EC > C. Tea extracts and standard flavanols had no antibacterial activity against Escherichia coli (MTCC-443) but, in combination with probiotic culture supernatants, this activity was seen. The Kangra tea thus, exerts antibacterial effect on bacterial pathogens through EGCG, ECG and EGC constituents while stimulatory effect on growth of indigenous potential probiotics.

  2. Sugaring-out extraction of acetoin from fermentation broth by coupling with fermentation.

    Science.gov (United States)

    Dai, Jian-Ying; Ma, Lin-Hui; Wang, Zhuang-Fei; Guan, Wen-Tian; Xiu, Zhi-Long

    2017-03-01

    Acetoin is a natural flavor and an important bio-based chemical which could be separated from fermentation broth by solvent extraction, salting-out extraction or recovered in the form of derivatives. In this work, a novel method named as sugaring-out extraction coupled with fermentation was tried in the acetoin production by Bacillus subtilis DL01. The effects of six solvents on bacterial growth and the distribution of acetoin and glucose in different solvent-glucose systems were explored. The operation parameters such as standing time, glucose concentration, and volume ratio of ethyl acetate to fermentation broth were determined. In a system composed of fermentation broth, glucose (100%, m/v) and two-fold volume of ethyl acetate, nearly 100% glucose was distributed into bottom phase, and 61.2% acetoin into top phase without coloring matters and organic acids. The top phase was treated by vacuum distillation to remove solvent and purify acetoin, while the bottom phase was used as carbon source to produce acetoin in the next batch of fermentation.

  3. Identification of the potential inhibitors of malolactic fermentation in wines

    Directory of Open Access Journals (Sweden)

    Renata Vieira da MOTA

    2017-10-01

    Full Text Available Abstract This exploratory work aims to identify the potential inhibitors of lactic bacterial growth and to propose enological practices to guarantee the occurrence of spontaneous malolactic fermentation (MLF in wines from traditional and double-pruning management harvests in southeast Brazil. One white wine from a summer harvest and one red wine from a winter harvest that failed to complete MLF were utilized as comparative models to identify inhibitor compounds to lactic bacteria. Wine composition, alcoholic-fermentation temperature and bacterial strain contribute to the success or failure of MLF. Temperatures below 12 °C during alcoholic fermentation decrease lactic bacterial metabolism and may impair the bacteria’s growth after yeast cells lysis. A must pH below 3.2 in a summer harvest impairs bacterial growth, and the association of low pH with a free-SO2 concentration above 10 mg L-1 may inhibit MLF. For grapes with a high sugar content, harvested in the winter cycle, enologists should keep the alcohol content below 15% and control the alcoholic-fermentation temperature.

  4. Options of sugar beet pretreatment for hydrogen fermentation

    NARCIS (Netherlands)

    Grabarczyk, R.; Urbaniec, K.; Koukios, E.; Bakker, R.R.C.; Vaccari, G.

    2011-01-01

    Hydrogen is expected to play a major role in covering the future energy demand. To make its future uses sustainable, hydrogen should be produced from renewable resources, for example by bacterial fermentation of biomass-derived feedstocks. Sugar beet is recognised as one of the most interesting raw

  5. Fermentation characteristics of Korean pear ( Pyrus pyrifolia Nakai ...

    African Journals Online (AJOL)

    A lactic acid bacterial strain showing fast growth and high acid production when cultured in Korean pear puree was isolated from Kimchi. This strain was analyzed by using the API 50 CHL kit and 16S rRNA sequencing and was thus identified as Leuconostoc mesenteroides 51-3. Korean pear puree was fermented with the ...

  6. Comparison of protease production from newly isolated bacterial ...

    African Journals Online (AJOL)

    Nasir

    2016-10-12

    Oct 12, 2016 ... The bacterial strain was obtained from soil which was collected from different areas of Lahore, Pakistan. Fermentation medium (by using sub-merged ... Four different supports were used for the immobilization of the bacterial protease by physical ... other proteins, regulating their size, composition, shape,.

  7. Variability of laboratory identification and antibiotic susceptibility reporting of Pseudomonas spp. isolates from dogs with chronic otitis externa.

    Science.gov (United States)

    Schick, Anthea E; Angus, John C; Coyner, Kimberly S

    2007-04-01

    The purpose of this study was to evaluate interlaboratory variation in isolation and antibiotic susceptibility pattern of Pseudomonas spp. as reported to veterinarians for cases of canine chronic bacterial otitis externa. Twenty-six dogs with unilateral or bilateral bacterial otitis externa from multiple referral practices were included in this prospective study. Triplicate samples collected simultaneously from the same location in the external ear canal were randomly submitted to three laboratories for culture and susceptibility testing. Pseudomonas spp. were isolated from 18 of 34 (53%) ears. All three laboratories agreed on the presence of Pseudomonas spp. in 15 (83.3%) ears sampled. However, two laboratories agreed on two (11.1%) occasions, and on one occasion (5.5%) Pseudomonas spp. were identified in only one laboratory. Minimum inhibitory concentration (MIC) susceptibilities to 11 antibiotics were compared between laboratories B and C. Using laboratory-defined susceptibility of sensitive (S), intermediate (I) and resistant (R), none of the 16 Pseudomonas spp. with MIC data reported had identical patterns of antibiotic susceptibility. Agreement in susceptibility to individual antibiotics was observed in 13 of 16 (81%) occasions for amikacin and gentamicin, 10 of 16 (63%) occasions for ticarcillin, and nine of 16 (56%) for enrofloxacin. These results indicate that Pseudomonas spp. were identified by all three laboratories chosen for this study in 83% of the time. Moreover, antibiotic susceptibility patterns and MIC values reported to veterinarians may not agree between laboratories. Veterinarians should interpret bacterial culture and susceptibility results with multiple caveats including variability between laboratories.

  8. Timing of malolactic fermentation inoculation in Shiraz grape must and wine: influence on chemical composition.

    Science.gov (United States)

    Abrahamse, Caroline E; Bartowsky, Eveline J

    2012-01-01

    Malolactic fermentation (MLF) is an integral step in red winemaking, which in addition to deacidifying wine can also influence the composition of volatile fermentation-derived compounds with concomitant affects on wine sensory properties. Long-established winemaking protocols for MLF induction generally involve inoculation of bacteria starter cultures post alcoholic fermentation, however, more recently there has been a trend to introduce bacteria earlier in the fermentation process. For the first time, this study shows the impact of bacterial inoculation on wine quality parameters that define red wine, including wine colour and phenolics, and volatile fermentation-derived compounds. This study investigates the effects of inoculating Shiraz grape must with malolactic bacteria at various stages of alcoholic fermentation [beginning of alcoholic fermentation (co-inoculation, with yeast), mid-alcoholic fermentation, at pressing and post alcoholic fermentation] on the kinetics of MLF and wine chemical composition. Co-inoculation greatly reduced the overall fermentation time by up to 6 weeks, the rate of alcoholic fermentation was not affected by the presence of bacteria and the fermentation-derived wine volatiles profile was distinct from wines produced where bacteria were inoculated late or post alcoholic fermentation. An overall slight decrease in wine colour density observed following MLF was not influenced by the MLF inoculation regime. However, there were differences in anthocyanin and pigmented polymer composition, with co-inoculation exhibiting the most distinct profile. Differences in yeast and bacteria metabolism at various stages in fermentation are proposed as the drivers for differences in volatile chemical composition. This study demonstrates, with an in-depth analysis, that co-inoculation of yeast and bacteria in wine fermentation results in shorter total vinification time and produces sound wines, thus providing the opportunity to stabilise wines more

  9. The effectiveness of novel bacteriocin derived from Escherichia coli colonized in the fermented pineapple Ananas comosus (L. Merr. against pathogenic bacteria isolated from aquaculture sites

    Directory of Open Access Journals (Sweden)

    S. W. Lee

    2014-11-01

    Full Text Available Aim: The aim was to evaluate antimicrobial property of bacteriocin isolated from Escherichia coli against pathogenic bacteria from aquaculture sites. Materials and Methods: E. coli was isolated from fermented pineapple Ananas comosus using eosin methylene blue agar. The antimicrobial activity of the isolated E. coli was screened using hole-plate diffusion method. The bacterial strain that showed the widest inhibition zone was selected and grown in tryptic soy broth, followed by partial purification of bacteriocin by using ammonium sulphate. Bacteriocin derived from the E. coli was subjected to the antimicrobial test against 55 bacteria strains namely Aeromonas hydrophila (n=10, Citrobacter freundii (n=5, Edwardsiella tarda (n=10, Flavobacterium spp. (n=10, Pseudomonas spp. (n=10, Vibrio parahaemolyticus (n=5 and Vibrio alginolyticus (n=5 by using twofold broth microdilution method to determine minimum inhibitory concentration (MIC values of the bacteriocin against the tested bacteria. Results: The results of the present study showed that the MIC values of the partially purified bacteriocin against present pathogenic bacteria isolates ranged from 7.81 to 31.25 ppm whereas the MIC values of kanamycin (positive control ranged from 15.63 to 125 ppm. Conclusion: The results of the present study showed the bacteriocin derived from E. coli can control all the present bacterial isolates indicating the huge potential of the bacteriocin as a new antimicrobial agent for aquaculture uses.

  10. Protein modification by fermentation

    DEFF Research Database (Denmark)

    Barkholt, Helle Vibeke; Jørgensen, P.B.; Sørensen, Anne Dorthe

    1998-01-01

    The effect of fermentation on components of potential significance for the allergenicity of pea was analyzed. Pea flour was fermented with three lactic acid bacteria, Pediococcus pentosaceus, Lactococcus raffinolactis, and Lactobacillus plantarum, and two fungi, Rhizopus microsporus, var....... oligosporus and Geotrichum candidum. Residual antigenicity against antipea antibodies was reduced to 10% by the three lactic acid bacteria and R. microsporus. Reactions to anti-pea profilin and anti-Bet v I were still detectable after fermentation. The contents of lectin and pea protease inhibitor were...

  11. Microbial colonization of naturally black olives during fermentation and associated biochemical activities in the cover brine.

    Science.gov (United States)

    Nychas, G-J E; Panagou, E Z; Parker, M L; Waldron, K W; Tassou, C C

    2002-01-01

    To establish the site of microbial growth on naturally black fermented table olives, and to monitor the population dynamics of yeasts and selected micro-organisms together with the changes in organic acid profile and pH in the cover brine during fermentation. During fermentation, the numbers of Enterobacteriaceae and Pseudomonas spp. in the brine decreased whilst lactic acid bacteria and yeast populations increased. Scanning electron microscopy showed that a yeast-rich biofilm developed on the epicuticular wax of the olive skin during fermentation. Yeasts also predominated in the stomatal openings, but bacteria were more numerous in intercellular spaces in the sub-stomatal flesh. Citric, malic and tartaric acids were the major organic acids accumulating in the brine during fermentation. Micro-organisms associated with the skin, stomata and flesh in fermenting black olives may experience different local conditions to those prevailing in the cover brine. These are the first observations of the micro-organisms associated with the fruit of naturally fermented black olives and of the accumulation of specific organic acids during fermentation.

  12. Glycerine and levulinic acid: renewable co-substrates for the fermentative synthesis of short-chain poly(hydroxyalkanoate) biopolymers

    Science.gov (United States)

    Glycerine and levulinic acid were used alone and in combination for the fermentative synthesis of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB/V) biopolymers. Shake-flask cultures of Pseudomonas oleovorans NRRL B-14682 containing different glycerine:levulinic acid ratios (1%, w/v total carbon ...

  13. Surface Sensing for Biofilm Formation in Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Chien-Yi Chang

    2018-01-01

    Full Text Available Aggregating and forming biofilms on biotic or abiotic surfaces are ubiquitous bacterial behaviors under various conditions. In clinical settings, persistent presence of biofilms increases the risks of healthcare-associated infections and imposes huge healthcare and economic burdens. Bacteria within biofilms are protected from external damage and attacks from the host immune system and can exchange genomic information including antibiotic-resistance genes. Dispersed bacterial cells from attached biofilms on medical devices or host tissues may also serve as the origin of further infections. Understanding how bacteria develop biofilms is pertinent to tackle biofilm-associated infections and transmission. Biofilms have been suggested as a continuum of growth modes for adapting to different environments, initiating from bacterial cells sensing their attachment to a surface and then switching cellular physiological status for mature biofilm development. It is crucial to understand bacterial gene regulatory networks and decision-making processes for biofilm formation upon initial surface attachment. Pseudomonas aeruginosa is one of the model microorganisms for studying bacterial population behaviors. Several hypotheses and studies have suggested that extracellular macromolecules and appendages play important roles in bacterial responses to the surface attachment. Here, I review recent studies on potential molecular mechanisms and signal transduction pathways for P. aeruginosa surface sensing.

  14. Inoculante enzimático-bacteriano, composição química e parâmetros fermentativos das silagens dos capins Tanzânia e Mombaça Enzymatic-bacterial inoculants, chemical composition and fermentation characteristics of Tanzaniagrass and Mombaçagrass silages

    Directory of Open Access Journals (Sweden)

    Rogério Marchiori Coan

    2005-04-01

    Full Text Available Objetivou-se, com o presente trabalho, avaliar os efeitos de idades de colheita e do uso de inoculante enzimático-bacteriano sobre os parâmetros de fermentação, de composição química e digestibilidade in vitro da matéria seca (DIVMS das silagens dos cultivares Tanzânia e Mombaça (Panicum maximum Jacq.. As forragens foram colhidas aos 45 e 60 dias após o corte de uniformização, submetidas a dois tratamentos (A - Ensilagem sem aditivo [Controle]; B - Ensilagem com adição de inoculante enzimático-bacteriano e distribuídas em um delineamento inteiramente casualizado em esquema fatorial (dois capins x duas inoculações x duas idades de corte, com três repetições. O conteúdo de MS das silagens confeccionadas com as plantas colhidas aos 60 dias de rebrota foi superior àquele das silagens colhidas com 45 dias. As silagens confeccionadas com as plantas colhidas aos 45 dias de rebrota apresentaram os maiores teores de PB (11,9%. Não se observaram efeitos das silagens, dos tratamentos e das idades de corte sobre os teores de hemicelulose, celulose e DIVMS e valores de pH e N-NH3. As silagens do capim-tanzânia apresentaram os maiores teores de MS, FDN, FDA, ácido lático e ácido butírico, enquanto as de capim-mombaça, os de PB e de ácido acético. A adição de inoculante enzimático-bateriano promoveu silagens com menores teores de MS, PB e lignina que as não-tratadas. Os capins tanzânia e mombaça não apresentaram limitações ao processo de ensilagem. O inoculante enzimático-bacteriano não melhorou as características qualitativas, fermentativas e nutricionais das silagens avaliadas.The objective of this trial was to evaluate the effect of the harvest time (45 or 60 days of regrowth, and enzymatic-bacterial inoculants on the fermentation characteristics, chemical composition, in vitro dry matter digestibility (IVDMD of silages from Tanzânia and Mombaça (Panicum maximum Jacq. cultivars. Forages, cut in the different

  15. Effect of Fermented Spinach as Sources of Pre-Converted Nitrite on Color Development of Cured Pork Loin.

    Science.gov (United States)

    Kim, Tae-Kyung; Kim, Young-Boong; Jeon, Ki-Hong; Park, Jong-Dae; Sung, Jung-Min; Choi, Hyun-Wook; Hwang, Ko-Eun; Choi, Yun-Sang

    2017-01-01

    The effect of fermented spinach extracts on color development in cured meats was investigated in this study. The pH values of raw cured meats without addition of fermented spinach extract or nitrite (negative control) were higher (pcured meats in treatment groups were decreased with increasing addition levels of fermented spinach extract. The lightness and yellowness values of raw cured meats formulated with fermented spinach extract were higher (pcured meats were increased with increasing fermented spinach extract levels, whereas the yellowness values of cooked cured meats were decreased with increasing levels of fermented spinach extract. The lowest volatile basic nitrogen (VBN) and thiobarbituric acid reactive substances (TBARS) values were observed in the positive control group with addition of nitrite. TBARS values of cured meats added with fermented spinach extract were decreased with increasing levels of fermented spinach extract and VBN values of curing meat with 30% fermented spinach extract was lower than the other treatments. Total viable bacterial counts in cured meats added with fermented spinach extract ranged from 0.34-1.01 Log CFU/g. E. coli and coliform bacteria were not observed in any of the cured meats treated with fermented spinach extracts or nitrite. Residual nitrite contents in treatment groups were increased with increasing levels of fermented spinach extract added. These results demonstrated that fermented spinach could be added to meat products to improve own curing characteristics.

  16. Pseudomonas guariconensis sp. nov., isolated from rhizospheric soil.

    Science.gov (United States)

    Toro, Marcia; Ramírez-Bahena, Martha-Helena; Cuesta, Maria José; Velázquez, Encarna; Peix, Alvaro

    2013-12-01

    We isolated a bacterial strain designated PCAVU11(T) in the course of a study of phosphate-solubilizing bacteria occurring in rhizospheric soil of Vigna unguiculata (L.) Walp. in Guárico state, Venezuela. The 16S rRNA gene sequence had 99.2 % sequence similarity with respect to the most closely related species, Pseudomonas taiwanensis, and 99.1 % with respect to Pseudomonas entomophila, Pseudomonas plecoglossicida and Pseudomonas monteilii, on the basis of which PCAVU11(T) was classified as representing a member of the genus Pseudomonas. Analysis of the housekeeping genes rpoB, rpoD and gyrB confirmed the phylogenetic affiliation and showed sequence similarities lower than 95 % in all cases with respect to the above-mentioned closest relatives. Strain PCAVU11(T) showed two polar flagella. The respiratory quinone was Q9. The major fatty acids were 16 : 0 (25.7 %), 18 : 1ω7c (20.4 %), 17 : 0 cyclo (11.5 %) and 16 : 1ω7c/15 : 0 iso 2-OH in summed feature 3 (10.8 %). The strain was oxidase-, catalase- and urease-positive, the arginine dihydrolase system was present but nitrate reduction, β-galactosidase production and aesculin hydrolysis were negative. Strain PCAVU11(T) grew at 44 °C and at pH 10. The DNA G+C content was 61.5 mol%. DNA-DNA hybridization results showed values lower than 56 % relatedness with respect to the type strains of the four most closely related species. Therefore, the results of genotypic, phenotypic and chemotaxonomic analyses support the classification of strain PCAVU11(T) as representing a novel species of the genus Pseudomonas, which we propose to name Pseudomonas guariconensis sp. nov. The type strain is PCAVU11(T) ( = LMG 27394(T) = CECT 8262(T)).

  17. Survival and growth of selected pathogens in fermented kocho (Ensete ventricosum).

    Science.gov (United States)

    Nigatu, A; Gashe, B A

    1994-08-01

    A study was conducted to investigate the antagonistic potential of fermented kocho, aqueous extract of fermented kocho and spent media from lactic acid bacteria (LAB) isolated from it on Salmonella sp, Pseudomonas aeruginosa, Klebsiella sp, Bacillus cereus and Staphylococcus aureus. Fermented kocho (pH 4.3) inhibited growth of the test bacteria soon after their introduction into the food. The spent media from all of the four LAB, isolated from fermented kocho, namely Pediococcus sp, Leuconostoc sp, Lactobacillus sp and Streptococcus sp prevented the survival and growth of the test bacteria. The spent medium from Streptococcus sp showed the best antagonistic effect amongst all the LAB isolates. In all cases the inhibitory effects were independent of pH.

  18. Multivariate analysis of microarray data by principal component discriminant analysis: Prioritizing relevant transcripts linked to the degradation of different carbohydrates in Pseudomonas putida S12

    NARCIS (Netherlands)

    Werf, M.J. van der; Pieterse, B.; Luijk, N. van; Schuren, F.; Werff van der - Vat, B. van der; Overkamp, K.; Jellema, R.H.

    2006-01-01

    The value of the multivariate data analysis tools principal component analysis (PCA) and principal component discriminant analysis (PCDA) for prioritizing leads generated by microarrays was evaluated. To this end, Pseudomonas putida S12 was grown in independent triplicate fermentations on four

  19. Industrial fermentation in China

    Energy Technology Data Exchange (ETDEWEB)

    Chen, T.S.

    1982-07-01

    A brief description of the recent advances in industrial fermentation in China is presented. Subject areas discussed include century-old food products such as Soy sauce and 'Shao Jiu' (distilled spirits), ethanol, amino acid, citric acid, nucleic acid and enzymes. Also discussed are the recent studies on immobilised enzymes and cells and on long-chain dicarboxylic acid fermentation. (Refs. 9).

  20. Role of Fermentation in Improving Nutritional Quality of Soybean Meal — A Review

    Directory of Open Access Journals (Sweden)

    Runni Mukherjee

    2016-11-01

    Full Text Available Soybean meal (SBM, a commonly used protein source for animal feed, contains anti-nutritional factors such as trypsin inhibitor, phytate, oligosaccharides among others, which limit its utilization. Microbial fermentation using bacteria or fungi has the capability to improve nutritional value of SBM by altering the native composition. Both submerged and solid state fermentation processes can be used for this purpose. Bacterial and fungal fermentations result in degradation of various anti-nutritional factors, an increase in amount of small-sized peptides and improved content of both essential and non-essential amino acids. However, the resulting fermented products vary in levels of nutritional components as the two species used for fermentation differ in their metabolic activities. Compared to SBM, feeding non-ruminants with fermented SBM has several beneficial effects including increased average daily gain, improved growth performance, better protein digestibility, decreased immunological reactivity and undesirable morphological changes like absence of granulated pinocytotic vacuoles.

  1. Bacterial conjunctivitis

    OpenAIRE

    Epling, John

    2012-01-01

    Conjunctivitis causes irritation, itching, foreign body sensation, and watering or discharge of the eye. Most cases in adults are probably due to viral infection, but children are more likely to develop bacterial conjunctivitis than viral forms. The main bacterial pathogens are Staphylococcus species in adults, and Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis in children.A bacterial cause is more likely if there is gluing of the eyelids and no itch.Contact le...

  2. Bacterial conjunctivitis

    OpenAIRE

    Epling, John

    2010-01-01

    Conjunctivitis causes irritation, itching, foreign body sensation, and watering or discharge of the eye. Most cases in adults are probably due to viral infection, but children are more likely to develop bacterial conjunctivitis than viral forms. The main bacterial pathogens are Staphylococcus species in adults, and Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis in children.A bacterial cause is more likely if there is glueing of the eyelids and no itch.Contact l...

  3. Solid substrate fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Tengerdy, R.P.

    1985-04-01

    Solid Substrate Fermentation (SSF) describes the microbiological tranformation of biological materials in their natural state, in contrast with liquid or submerged fermentations which are carried out in dilute solutions or slurries. The most important industrial microorganisms used in SSF are filamentous fungi and the critical factors in their growth are the control of the moisture level and the temperature. Traditionally, most SSFs are conducted in shallow trays (so that heat build up is avoided) and stacked in a moist chamber, however, the modern SSF should be able to mix large amounts of substrate for a uniform fermentation, maximum automization scale-up of the process, continuous operation and fermentation control and a promising new design is the Helical screw fermenter. At the present time SSF is used in the production of foods (e.g. mushrooms and oriental foods) in municipal, agricultural and industrial solid waste disposal and in the production of enzymes and speciality chemicals but it does not seem likely that it will replace prevalent liquid fermentation technologies. 29 references.

  4. HOPM1 mediated disease resistance to Pseudomonas syringae in Arabidopsis

    Science.gov (United States)

    He, Sheng Yang [Okemos, MI; Nomura, Kinya [East Lansing, MI

    2011-11-15

    The present invention relates to compositions and methods for enhancing plant defenses against pathogens. More particularly, the invention relates to enhancing plant immunity against bacterial pathogens, wherein HopM1.sub.1-300 mediated protection is enhanced, such as increased protection to Pseudomonas syringae pv. tomato DC3000 HopM1 and/or there is an increase in activity of an ATMIN associated plant protection protein, such as ATMIN7. Reagents of the present invention further provide a means of studying cellular trafficking while formulations of the present inventions provide increased pathogen resistance in plants.

  5. Development of potent inhibitors of pyocyanin production in Pseudomonas aeruginosa.

    Science.gov (United States)

    Miller, Laura C; O'Loughlin, Colleen T; Zhang, Zinan; Siryaporn, Albert; Silpe, Justin E; Bassler, Bonnie L; Semmelhack, Martin F

    2015-02-12

    The development of new approaches for the treatment of antimicrobial-resistant infections is an urgent public health priority. The Pseudomonas aeruginosa pathogen, in particular, is a leading source of infection in hospital settings, with few available treatment options. In the context of an effort to develop antivirulence strategies to combat bacterial infection, we identified a series of highly effective small molecules that inhibit the production of pyocyanin, a redox-active virulence factor produced by P. aeruginosa. Interestingly, these new antagonists appear to suppress P. aeruginosa virulence factor production through a pathway that is independent of LasR and RhlR.

  6. Simultaneous and successive inoculations of yeasts and lactic acid bacteria on the fermentation of an unsulfited Tannat grape must

    Directory of Open Access Journals (Sweden)

    Viviana Muñoz

    2014-01-01

    Full Text Available Interactions between yeasts and lactic acid bacteria are strain specific, and their outcome is expected to change in simultaneous alcoholic -malolactic fermentations from the pattern observed in successive fermentations. One Oenococcus oeni strain Lalvin VP41TM was inoculated with two Saccharomyces cerevisiae strains either simultaneously, three days after the yeast inoculation, or when alcoholic fermentation was close to finish. Early bacterial inoculations with each yeast strain allowed for the growth of the bacterial populations, and the length of malolactic fermentation was reduced to six days. Alcoholic fermentation by Lalvin ICV D80® yeast strain left the highest residual sugar, suggesting a negative effect of the bacterial growth and malolactic activity on its performance. In sequential inoculations the bacterial populations did not show actual growth with either yeast strain. In this strategy, both yeast strains finished the alcoholic fermentations, and malolactic fermentations took longer to finish. Lalvin ICV D80® allowed for higher viability and activity of the bacterial strain than Fermicru UY4® under the three inoculation strategies. This was beneficial for the sequential completion of both fermentations, but negatively affected the completion of alcoholic fermentation by Lalvin ICV D80® in the early bacteria additions. Conversely, Fermicru UY4®, which was rather inhibitory towards the bacteria, favored the timely completion of both fermentations simultaneously. As bacteria in early inoculations with low or no SO2 addition can be expected to multiply and interact with fermenting yeasts, not only are the yeast-bacterium strains combination and time point of the inoculation to be considered, but also the amount of bacteria inoculated.

  7. Simultaneous and successive inoculations of yeasts and lactic acid bacteria on the fermentation of an unsulfited Tannat grape must.

    Science.gov (United States)

    Muñoz, Viviana; Beccaria, Bruno; Abreo, Eduardo

    2014-01-01

    Interactions between yeasts and lactic acid bacteria are strain specific, and their outcome is expected to change in simultaneous alcoholic--malolactic fermentations from the pattern observed in successive fermentations. One Oenococcus oeni strain Lalvin VP41™ was inoculated with two Saccharomyces cerevisiae strains either simultaneously, three days after the yeast inoculation, or when alcoholic fermentation was close to finish. Early bacterial inoculations with each yeast strain allowed for the growth of the bacterial populations, and the length of malolactic fermentation was reduced to six days. Alcoholic fermentation by Lalvin ICV D80® yeast strain left the highest residual sugar, suggesting a negative effect of the bacterial growth and malolactic activity on its performance. In sequential inoculations the bacterial populations did not show actual growth with either yeast strain. In this strategy, both yeast strains finished the alcoholic fermentations, and malolactic fermentations took longer to finish. Lalvin ICV D80® allowed for higher viability and activity of the bacterial strain than Fermicru UY4® under the three inoculation strategies. This was beneficial for the sequential completion of both fermentations, but negatively affected the completion of alcoholic fermentation by Lalvin ICV D80® in the early bacteria additions. Conversely, Fermicru UY4®, which was rather inhibitory towards the bacteria, favored the timely completion of both fermentations simultaneously. As bacteria in early inoculations with low or no SO2 addition can be expected to multiply and interact with fermenting yeasts, not only are the yeast-bacterium strains combination and time point of the inoculation to be considered, but also the amount of bacteria inoculated.

  8. Adherence of Pseudomonas aeruginosa onto surfactant-laden contact lenses.

    Science.gov (United States)

    Mosuela, Reynalyn; Mustafa, Shelan; Gould, Simon; Hassanin, Hany; Alany, Raid G; ElShaer, Amr

    2018-03-01

    There is an immense research interest to utilise contact lens (CLs) as a popular platform for ocular drug delivery. However, CLs are the major predisposing factors of bacterial keratitis which is commonly caused by adhesion of microbes such as Pseudomonas aeruginosa and Staphylococcus epidermidis. The aim of the current study is to explore the effect of surfactants; Poloxamer 188, Polysorbate 80 and Tetronic ® 90R4 (at 0.25% - 3% v/v) on the characteristics of CLs and on the adhesion abilities of Pseudomonas aeruginosa to the lenses' surfaces. CLs were formulated using a hydrophilic monomer; 2-hydroxyethyl methacrylate (HEMA) together with silicone-based polymer such as Poly dimethyl siloxane (PDMS) or 3,3,3-trifluoropropylsilane (FSA) then lenses were polymerized under UV light. The formulated CLs with surfactants were found to have an increased equilibrium water content (EWC) due to hydrophilic moiety present in surfactants. A relationship was deduced between EWC and surface contact angle of lenses containing surfactants; where an increased EWC was associated with a decrease in contact angle reflecting a more hydrophilic surfaces of CLs. Apart from the 3% Polysorbate 80 (p Lenses with surfactants were found to have lower bacterial ATP concentration than lenses without surfactants. Poloxamer 188 in FSA lenses reduced bacterial adhesion from 4.22 × 10 -4  ± 1.30 × 10 -4 pM to 1.03 × 10 -4  ± 4.86 × 10 -5 pM, a reduction by 75.59% when compared to the control lenses (p = .002). Moreover, 1% Tetronic ® 90R4 in PDMS showed a reduction by 57.17% in ATP concentration. Polysorbate 80 in FSA exhibited the least bacterial adhesion with an average bacterial ATP concentration of 3.85 × 10 -5  ± 2.61 × 10 -5 pM; i.e 90.88% less bacterial ATP than control lenses (p = .001). Bioluminescence studies demonstrated a decrease in Pseudomonas aeruginosa adhesion to CLs containing surfactants without impairing the optical and

  9. Inhibitory activity of cheese whey fermented with kefir grains.

    Science.gov (United States)

    Londero, A; Quinta, R; Abraham, A G; Sereno, R; De Antoni, G; Garrote, G L

    2011-01-01

    We investigated the chemical and microbiological compositions of three types of whey to be used for kefir fermentation as well as the inhibitory capacity of their subsequent fermentation products against 100 Salmonella sp. and 100 Escherichia coli pathogenic isolates. All the wheys after fermentation with 10% (wt/vol) kefir grains showed inhibition against all 200 isolates. The content of lactic acid bacteria in fermented whey ranged from 1.04 × 10(7) to 1.17 × 10(7) CFU/ml and the level of yeasts from 2.05 × 10(6) to 4.23 × 10(6) CFU/ml. The main changes in the chemical composition during fermentation were a decrease in lactose content by 41 to 48% along with a corresponding lactic acid production to a final level of 0.84 to 1.20% of the total reaction products. The MIC was a 30% dilution of the fermentation products for most of the isolates, while the MBC varied between 40 and 70%, depending on the isolate. The pathogenic isolates Salmonella enterica serovar Enteritidis 2713 and E. coli 2710 in the fermented whey lost their viability after 2 to 7 h of incubation. When pathogens were deliberately inoculated into whey before fermentation, the CFU were reduced by 2 log cycles for E. coli and 4 log cycles for Salmonella sp. after 24 h of incubation. The inhibition was mainly related to lactic acid production. This work demonstrated the possibility of using kefir grains to ferment an industrial by-product in order to obtain a natural acidic preparation with strong bacterial inhibitory properties that also contains potentially probiotic microorganisms.

  10. Hypoxia Reduces the Pathogenicity of Pseudomonas aeruginosa by Decreasing the Expression of Multiple Virulence Factors.

    Science.gov (United States)

    Schaible, Bettina; Rodriguez, Javier; Garcia, Amaya; von Kriegsheim, Alexander; McClean, Siobhán; Hickey, Caitríona; Keogh, Ciara E; Brown, Eric; Schaffer, Kirsten; Broquet, Alexis; Taylor, Cormac T

    2017-05-01

    Our understanding of how the course of opportunistic bacterial infection is influenced by the microenvironment is limited. We demonstrate that the pathogenicity of Pseudomonas aeruginosa strains derived from acute clinical infections is higher than that of strains derived from chronic infections, where tissues are hypoxic. Exposure to hypoxia attenuated the pathogenicity of strains from acute (but not chronic) infections, implicating a role for hypoxia in regulating bacterial virulence. Mass spectrometric analysis of the secretome of P. aeruginosa derived from an acute infection revealed hypoxia-induced repression of multiple virulence factors independent of altered bacterial growth. Pseudomonas aeruginosa lacking the Pseudomonas prolyl-hydroxylase domain-containing protein, which has been implicated in bacterial oxygen sensing, displays reduced virulence factor expression. Furthermore, pharmacological hydroxylase inhibition reduces virulence factor expression and pathogenicity in a murine model of pneumonia. We hypothesize that hypoxia reduces P. aeruginosa virulence at least in part through the regulation of bacterial hydroxylases. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  11. Biohydrogen production from soluble condensed molasses fermentation using anaerobic fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Lay, Chyi-How; Lin, Chiu-Yue [Department of Environmental Engineering and Science, Feng Chia University, Taichung 40724 (China); Wu, Jou-Hsien; Hsiao, Chin-Lang [Department of Water Resource Engineering, Feng Chia University (China); Chang, Jui-Jen [Department of Life Sciences, National Chung Hsing University (China); Chen, Chin-Chao [Environmental Resources Laboratory, Department of Landscape Architecture, Chungchou Institute of Technology (China)

    2010-12-15

    Using anaerobic micro-organisms to convert organic waste to produce hydrogen gas gives the benefits of energy recovery and environmental protection. The objective of this study was to develop a biohydrogen production technology from food wastewater focusing on hydrogen production efficiency and micro-flora community at different hydraulic retention times. Soluble condensed molasses fermentation (CMS) was used as the substrate because it is sacchariferous and ideal for hydrogen production. CMS contains nutrient components that are necessary for bacterial growth: microbial protein, amino acids, organic acids, vitamins and coenzymes. The seed sludge was obtained from the waste activated sludge from a municipal sewage treatment plant in Central Taiwan. This seed sludge was rich in Clostridium sp. A CSTR (continuously stirred tank reactor) lab-scale hydrogen fermentor (working volume, 4.0 L) was operated at a hydraulic retention time (HRT) of 3-24 h with an influent CMS concentration of 40 g COD/L. The results showed that the peak hydrogen production rate of 390 mmol H{sub 2}/L-d occurred at an organic loading rate (OLR) of 320 g COD/L-d at a HRT of 3 h. The peak hydrogen yield was obtained at an OLR of 80 g COD/L-d at a HRT of 12 h. At HRT 8 h, all hydrogenase mRNA detected were from Clostridium acetobutylicum-like and Clostridium pasteurianum-like hydrogen-producing bacteria by RT-PCR analysis. RNA based hydrogenase gene and 16S rRNA gene analysis suggests that Clostridium exists in the fermentative hydrogen-producing system and might be the dominant hydrogen-producing bacteria at tested HRTs (except 3 h). The hydrogen production feedstock from CMS is lower than that of sucrose and starch because CMS is a waste and has zero cost, requiring no added nutrients. Therefore, producing hydrogen from food wastewater is a more commercially feasible bioprocess. (author)

  12. SANITATION PROCESS OPTIMALIZATION IN RELATION TO THE MICROBIAL BIOFILM OF PSEUDOMONAS FLUORESCENS

    Directory of Open Access Journals (Sweden)

    Vladimír Vietoris

    2012-02-01

    Full Text Available Biofilms have been of considerable interest in the context of food hygiene. Extracellular polymeric substances play an important role in the attachment and colonization of microorganisms to food-contact surfaces. If the microorganisms from food-contact surfaces are not completely removed, they may lead to biofilm formation and also increase the biotransfer potential. The experimental part was focused on the adhesion of bacterial cells under static conditions and testing the effectiveness of disinfectants on created biofilm. In laboratory conditions we prepared and formed the bacterial biofilms Pseudomonas fluorescens in the test surfaces of stainless steel. Over the 72 hours and the next 72 hours were observed numbers of adhesion bacterial cells of Pseudomonas fluorescens on solid surfaces of tested materials.

  13. Enzymatic removal and disinfection of bacterial biofilms

    DEFF Research Database (Denmark)

    Johansen, Charlotte; Falholt, Per; Gram, Lone

    1997-01-01

    Model biofilms of Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas fluorescens, and Pseudomonas aeruginosa were made on steel and polypropylene substrata. Plaque-resembling biofilms of Streptococcus mutans, Actinomyces, viscosus, and Fusobacterium nucleatum were made on saliva...... the biofilm from the substrata. A complex mixture of polysaccharide-hydrolyzing enzymes was able to remove bacterial biofilm from steel and polypropylene substrata but did not have a significant bactericidal activity. Combining oxidoreductases with polysaccharide-hydrolyzing enzymes resulted in bactericidal......-coated hydroxyapatite. The activity of enzymes against bacterial cells in biofilm was measured by fluorescence microscopy and an indirect conductance test in which evolution of carbon dioxide was measured. Glucose oxidase combined with lactoperoxidase was bactericidal against biofilm bacteria but did not remove...

  14. Biodegradation of crude oil by individual bacterial strains and a mixed bacterial consortium isolated from hydrocarbon contaminated areas

    Energy Technology Data Exchange (ETDEWEB)

    Raj Binupriya, Arthur [Research and Development Division, Regent Ecotech Private Limited, Coimbatore, Tamil Nadu (India); Baik, Sang-Ho [Radiation Application Research Division, ARTI, Korea Atomic Energy Research Institute, Jeongeup (Korea); Yun, Sei-Eok [Department of Food Science and Technology, Institute of Agricultural Science and Technology, Research Institute of Bioindustry, Chonbuk National University, Chonju (Korea); Sathishkumar, Muthuswamy

    2008-01-15

    A preliminary study was undertaken to determine the optimal conditions for the biodegradation of a crude oil. Among 57 oil-degrading bacterial cultures isolated from oil-contaminated soil samples, Bacillus sp. IOS1-7, Corynebacterium sp. BPS2-6, Pseudomonas sp. HPS2-5, and Pseudomonas sp. BPS1-8 were selected for the study based on the efficiency of crude oil utilization. Along with the selected individual strains, a mixed bacterial consortium prepared using the above strains was also used for degradation studies. The mixed bacterial consortium showed more growth and degradation than did individual strains. At 1% crude oil concentration, the mixed bacterial consortium degraded a maximum of 77% of the crude oil. This was followed by 69% by Pseudomonas sp. BPS1-8, 64% by Bacillus sp. IOS1-7, 45% by Pseudomonas sp. HPS2-5, and 41% by Corynebacterium sp. BPS2-6. The percentage of degradation by the mixed bacterial consortium decreased from 77 to 45% as the concentration of crude oil was increased from 1 to 12%. Temperature of 35 C and pH 7 were found to be optimum for maximum degradation. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  15. Photodynamic antimicrobial therapy to inhibit pseudomonas aeruginosa of corneal isolates (Conference Presentation)

    Science.gov (United States)

    Durkee, Heather A.; Relhan, Nidhi; Arboleda, Alejandro; Halili, Francisco; De Freitas, Carolina; Alawa, Karam; Aguilar, Mariela C.; Amescua, Guillermo; Miller, Darlene; Parel, Jean-Marie

    2016-03-01

    Keratitis associated with Pseudomonas aeruginosa is difficult to manage. Treatment includes antibiotic eye drops, however, some strains of Pseudomonas aeruginosa are resistant. Current research efforts are focused on finding alternative and adjunct therapies to treat multi-drug resistant bacteria. One promising alternate technique is photodynamic therapy (PDT). The purpose of this study was to evaluate the effect of riboflavin- and rose bengal-mediated PDT on Pseudomonas aeruginosa keratitis isolates in vitro. Two isolates (S+U- and S-U+) of Pseudomonas aeruginosa were derived from keratitis patients and exposed to five experimental groups: (1) Control (dark, UV-A irradiation, 525nm irradiation); (2) 0.1% riboflavin (dark, UV-A irradiation); and (3) 0.1% rose bengal, (4) 0.05% rose bengal and (5) 0.01% rose bengal (dark, 525nm irradiation). Three days after treatment, in dark conditions of all concentration of riboflavin and rose bengal showed no inhibition in both S+U- and S-U+ strains of Pseudomonas aeruginosa. In 0.1% and 0.05% rose bengal irradiated groups, for both S+U- and S-U+ strains, there was complete inhibition of bacterial growth in the central 50mm zone corresponding to the diameter of the green light source. These in vitro results suggest that rose bengal photodynamic therapy may be an effective adjunct treatment for Pseudomonas aeruginosa keratitis.

  16. Pseudomonas kribbensis sp. nov., isolated from garden soils in Daejeon, Korea.

    Science.gov (United States)

    Chang, Dong-Ho; Rhee, Moon-Soo; Kim, Ji-Sun; Lee, Yookyung; Park, Mi Young; Kim, Haseong; Lee, Seung-Goo; Kim, Byoung-Chan

    2016-11-01

    Two bacterial strains, 46-1 and 46-2(T), were isolated from garden soil. These strains were observed to be aerobic, Gram-stain negative, rod-shaped, non-spore-forming, motile and catalase and oxidase positive. Phylogenetic analysis based on 16S rRNA gene sequences showed that the two strains shared 100 % sequence similarity with each other and belong to the genus Pseudomonas in the class Gammaproteobacteria. The concatenated 16S rRNA, gyrB, rpoB and rpoD gene sequences further confirmed that the isolates belong to the Pseudomonas koreensis subgroup (SG), with P. koreensis Ps 9-14(T), Pseudomonas moraviensis 1B4(T) and Pseudomonas granadensis F-278,770(T) as their close relatives (>96 % pairwise similarity). DNA-DNA hybridization with the closely related type strain P. koreensis SG revealed a low level of relatedness (15 %) in the isolates but it was a minor component (Pseudomonas, for which the name Pseudomonas kribbensis sp. nov. is proposed; the type strain is 46-2(T) (=KCTC 32541(T) = DSM 100278(T)).

  17. Pseudomonas aeruginosa forms Biofilms in Acute InfectionIndependent of Cell-to-Cell Signaling

    Energy Technology Data Exchange (ETDEWEB)

    Schaber, J. Andy; Triffo, W.J.; Suh, Sang J.; Oliver, Jeffrey W.; Hastert, Mary C.; Griswold, John A.; Auer, Manfred; Hamood, Abdul N.; Rumbaugh, Kendra P.

    2006-09-20

    Biofilms are bacterial communities residing within a polysaccharide matrix that are associated with persistence and antibiotic resistance in chronic infections. We show that the opportunistic pathogen Pseudomonas aeruginosa forms biofilms within 8 hours of infection in thermally-injured mice, demonstrating that biofilms contribute to bacterial colonization in acute infections. P. aeruginosa biofilms were visualized within burned tissue surrounding blood vessels and adipose cells. Although quorum sensing (QS), a bacterial signaling mechanism, coordinates differentiation of biofilms in vitro, wild type and QS-deficient P. aeruginosa formed similar biofilms in vivo. Our findings demonstrate that P. aeruginosa forms biofilms on specific host tissues independent of QS.

  18. Pseudomonas syringae evades host Immunity by degrading flagellin monomers with alkaline protease AprA

    OpenAIRE

    Pel, M.J.C.; Dijken, A.J.H. van; Bardoel, B.W.; Seidl, M.F.; Ent, S. van der; van Strijp, J. A. G.

    2014-01-01

    Bacterial flagellin molecules are strong inducers of innate immune responses in both mammals and plants. The opportunistic pathogen Pseudomonas aeruginosa secretes an alkaline protease called AprA that degrades flagellin monomers. Here, we show that AprA is widespread among a wide variety of bacterial species. In addition, we investigated the role of AprA in virulence of the bacterial plant athogen P. syringae pv. tomato DC3000. The AprA-deficient DC3000 ΔaprA knockout mutant was significantl...

  19. Local domestication of lactic acid bacteria via cassava beer fermentation

    Directory of Open Access Journals (Sweden)

    Alese M. Colehour

    2014-07-01

    Full Text Available Cassava beer, or chicha, is typically consumed daily by the indigenous Shuar people of the Ecuadorian Amazon. This traditional beverage made from cassava tuber (Manihot esculenta is thought to improve nutritional quality and flavor while extending shelf life in a tropical climate. Bacteria responsible for chicha fermentation could be a source of microbes for the human microbiome, but little is known regarding the microbiology of chicha. We investigated bacterial community composition of chicha batches using Illumina high-throughput sequencing. Fermented chicha samples were collected from seven Shuar households in two neighboring villages in the Morona-Santiago region of Ecuador, and the composition of the bacterial communities within each chicha sample was determined by sequencing a region of the 16S ribosomal gene. Members of the genus Lactobacillus dominated all samples. Significantly greater phylogenetic similarity was observed among chicha samples taken within a village than those from different villages. Community composition varied among chicha samples, even those separated by short geographic distances, suggesting that ecological and/or evolutionary processes, including human-mediated factors, may be responsible for creating locally distinct ferments. Our results add to evidence from other fermentation systems suggesting that traditional fermentation may be a form of domestication, providing endemic beneficial inocula for consumers, but additional research is needed to identify the mechanisms and extent of microbial dispersal.

  20. Silver against Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Kirketerp-Møller, K.; Kristiansen, S.

    2007-01-01

    bacteria in both the planktonic and biofilm modes of growth. The action of silver on mature in vitro biofilms of Pseudomonas aeruginosa, a primary pathogen of chronic infected wounds, was investigated. The results show that silver is very effective against mature biofilms of P. aeruginosa...

  1. The Bacterial Microflora of Fish

    Directory of Open Access Journals (Sweden)

    B. Austin

    2002-01-01

    Full Text Available The results of numerous studies indicate that fish possess bacterial populations on or in their skin, gills, digestive tract, and light-emitting organs. In addition, the internal organs (kidney, liver, and spleen of healthy fish may contain bacteria, but there is debate on whether or not muscle is actually sterile. The numbers and taxonomic composition of the bacterial populations often reflect those of the surrounding water. The role of the bacteria includes the ability to degrade complex molecules (therefore exercising a potential benefit in nutrition, to produce vitamins and polymers, and to be responsible for the emission of light by the light-emitting organs of deep-sea fish. Taxa, including Pseudomonas, may contribute to spoilage by the production of histamines in fish tissue.

  2. Bacterial Meningitis

    Science.gov (United States)

    ... Vaccine Schedules Preteen & Teen Vaccines Meningococcal Disease Sepsis Bacterial Meningitis Language: English (US) Español (Spanish) Recommend on ... Symptoms Diagnosis Treatment Prevention Reference Español: Meningitis bacteriana Bacterial meningitis is very serious and can be deadly. Death ...

  3. Bacterial adhesion

    NARCIS (Netherlands)

    Loosdrecht, van M.C.M.

    1988-01-01

    As mentioned in the introduction of this thesis bacterial adhesion has been studied from a variety of (mostly practice oriented) starting points. This has resulted in a range of widely divergent approaches. In order to elucidate general principles in bacterial adhesion phenomena, we felt it

  4. Comprehensive analysis of draft genomes of two closely related Pseudomonas syringae phylogroup 2b strains infecting mono and dicotyledon host plants

    Science.gov (United States)

    In recent years, the damage caused by bacterial pathogens to major crops has been increasing worldwide. Pseudomonas syringae is a widespread bacterial species that infects almost all major crops. Different P. syringae strains use a wide range of biochemical mechanisms, including phytotoxins and effe...

  5. MICROBIAL BIOFILMS PRODUCED BY PSEUDOMONAS FLUORESCENS ON SOLID SURFACES

    Directory of Open Access Journals (Sweden)

    Dagmar Kozelová

    2011-04-01

    Full Text Available Normal 0 21 false false false MicrosoftInternetExplorer4 Normal 0 21 false false false MicrosoftInternetExplorer4 A biofilm is a complex aggregation of microorganisms growing on a solid substrate. Biofilms are characterized by structural heterogeneity, genetic diversity, complex community interactions, and an extracellular matrix of polymeric substances. The experimental part was focused on the adhesion of bacterial cells under static conditions and testing the effectiveness of disinfectants on created biofilm. In laboratory conditions we prepared and formed the bacterial biofilms Pseudomonas fluorescens in the four test surfaces of stainless steel, glass and plastic materials - PE (polyethylene and EPDM (ethylene propylene diene monomer. Over the next 72 hours and 72 hours were observed numbers of adhesion bacterial cells of P. fluorescens on solid surfaces of tested materials. The highest values adhesion cells reached P. fluorescens cells after 72 hours of cultivation on plastic surfaces, where  was increased in adhesion bacterial cells for EPDM in the values of 105 CFU/cm2 and for PE up to 106 CFU/cm2. The subsequent repeated 72-hour cultivation P. fluorescens was an increase (growth in the number of adhesion bacterial cells to all tested surfaces.doi:10.5219/18  

  6. The clinical impact of bacterial biofilms

    DEFF Research Database (Denmark)

    Høiby, Niels; Ciofu, Oana; Johansen, Helle Krogh

    2011-01-01

    . Bacterial biofilms are resistant to antibiotics, disinfectant chemicals and to phagocytosis and other components of the innate and adaptive inflammatory defense system of the body. It is known, for example, that persistence of staphylococcal infections related to foreign bodies is due to biofilm formation....... Likewise, chronic Pseudomonas aeruginosa lung infections in cystic fibrosis patients are caused by biofilm growing mucoid strains. Gradients of nutrients and oxygen exist from the top to the bottom of biofilms and the bacterial cells located in nutrient poor areas have decreased metabolic activity...

  7. Respiratory bacterial infections in cystic fibrosis

    DEFF Research Database (Denmark)

    Ciofu, Oana; Hansen, Christine R; Høiby, Niels

    2013-01-01

    PURPOSE OF REVIEW: Bacterial respiratory infections are the main cause of morbidity and mortality in patients with cystic fibrosis (CF). Pseudomonas aeruginosa remains the main pathogen in adults, but other Gram-negative bacteria such as Achromobacter xylosoxidans and Stenotrophomonas maltophilia...... and site of bacterial adaptation has been recognized. This review will focus on the different conditions encountered by the bacteria in sinuses and lung, as well as the principles of treatment in the different infection sites. SUMMARY: Chronic, pulmonary infections remain the single most prominent cause...

  8. Enzymatic synthesis oF L-tryptophan from D,L-2-amino-delta2-thiazoline-4-carboxylic acid and indole by Pseudomonas sp. TS1138 L-2-amino-delta2-thiazoline-4-carboxylic acid hydrolase, S-carbamyl-L-cysteine amidohydrolase, and Escherichia coli L-tryptophanase.

    Science.gov (United States)

    Du, J; Duan, J J; Zhang, Q; Hou, J; Bai, F; Chen, N; Bai, G

    2012-01-01

    L-Tryptophan (L-Trp) is an essential amino acid. It is widely used in medical, health and food products, so a low-cost supply is needed. There are 4 methods for L-Trp production: chemical synthesis, extraction, enzymatic synthesis, and fermentation. In this study, we produced a recombinant bacterial strain pET-tnaA of Escherichia coli which has the L-tryptophanase gene. Using the pET-tnaA E. coli and the strain TS1138 of Pseudomonas sp., a one-pot enzymatic synthesis of L-Trp was developed. Pseudomonas sp. TS1138 was added to a solution of D,L-2-amino-delta2-thiazoline-4-carboxylic acid (DL-ATC) to convert it to L-cysteine (L-Cys). After concentration, E. coli BL21 (DE 3) cells including plasmid pET-tnaA, indole, and pyridoxal 5'-phosphate were added. At the optimum conditions, the conversion rates of DL-ATC and L-Cys were 95.4% and 92.1%, respectively. After purifying using macroporous resin S8 and NKA-II, 10.32 g of L-Trp of 98.3% purity was obtained. This study established methods for one-pot enzymatic synthesis and separation of L-Trp. This method of producing L-Trp is more environmentally sound than methods using chemical synthesis, and it lays the foundations for industrial production of L-Trp from DL-ATC and indole.

  9. Homo- and heterofermentative lactobacilli differently affect sugarcane-based fuel ethanol fermentation.

    Science.gov (United States)

    Basso, Thiago Olitta; Gomes, Fernanda Sgarbosa; Lopes, Mario Lucio; de Amorim, Henrique Vianna; Eggleston, Gillian; Basso, Luiz Carlos

    2014-01-01

    Bacterial contamination during industrial yeast fermentation has serious economic consequences for fuel ethanol producers. In addition to deviating carbon away from ethanol formation, bacterial cells and their metabolites often have a detrimental effect on yeast fermentative performance. The bacterial contaminants are commonly lactic acid bacteria (LAB), comprising both homo- and heterofermentative strains. We have studied the effects of these two different types of bacteria upon yeast fermentative performance, particularly in connection with sugarcane-based fuel ethanol fermentation process. Homofermentative Lactobacillus plantarum was found to be more detrimental to an industrial yeast strain (Saccharomyces cerevisiae CAT-1), when compared with heterofermentative Lactobacillus fermentum, in terms of reduced yeast viability and ethanol formation, presumably due to the higher titres of lactic acid in the growth medium. These effects were only noticed when bacteria and yeast were inoculated in equal cell numbers. However, when simulating industrial fuel ethanol conditions, as conducted in Brazil where high yeast cell densities and short fermentation time prevail, the heterofermentative strain was more deleterious than the homofermentative type, causing lower ethanol yield and out competing yeast cells during cell recycle. Yeast overproduction of glycerol was noticed only in the presence of the heterofermentative bacterium. Since the heterofermentative bacterium was shown to be more deleterious to yeast cells than the homofermentative strain, we believe our findings could stimulate the search for more strain-specific antimicrobial agents to treat bacterial contaminations during industrial ethanol fermentation.

  10. Gene expression in Pseudomonas aeruginosa swarming motility

    Directory of Open Access Journals (Sweden)

    Déziel Eric

    2010-10-01

    Full Text Available Abstract Background The bacterium Pseudomonas aeruginosa is capable of three types of motilities: swimming, twitching and swarming. The latter is characterized by a fast and coordinated group movement over a semi-solid surface resulting from intercellular interactions and morphological differentiation. A striking feature of swarming motility is the complex fractal-like patterns displayed by migrating bacteria while they move away from their inoculation point. This type of group behaviour is still poorly understood and its characterization provides important information on bacterial structured communities such as biofilms. Using GeneChip® Affymetrix microarrays, we obtained the transcriptomic profiles of both bacterial populations located at the tip of migrating tendrils and swarm center of swarming colonies and compared these profiles to that of a bacterial control population grown on the same media but solidified to not allow swarming motility. Results Microarray raw data were corrected for background noise with the RMA algorithm and quantile normalized. Differentially expressed genes between the three conditions were selected using a threshold of 1.5 log2-fold, which gave a total of 378 selected genes (6.3% of the predicted open reading frames of strain PA14. Major shifts in gene expression patterns are observed in each growth conditions, highlighting the presence of distinct bacterial subpopulations within a swarming colony (tendril tips vs. swarm center. Unexpectedly, microarrays expression data reveal that a minority of genes are up-regulated in tendril tip populations. Among them, we found energy metabolism, ribosomal protein and transport of small molecules related genes. On the other hand, many well-known virulence factors genes were globally repressed in tendril tip cells. Swarm center cells are distinct and appear to be under oxidative and copper stress responses. Conclusions Results reported in this study show that, as opposed to

  11. Xylose fermentation to ethanol

    Energy Technology Data Exchange (ETDEWEB)

    McMillan, J.D.

    1993-01-01

    The past several years have seen tremendous progress in the understanding of xylose metabolism and in the identification, characterization, and development of strains with improved xylose fermentation characteristics. A survey of the numerous microorganisms capable of directly fermenting xylose to ethanol indicates that wild-type yeast and recombinant bacteria offer the best overall performance in terms of high yield, final ethanol concentration, and volumetric productivity. The best performing bacteria, yeast, and fungi can achieve yields greater than 0.4 g/g and final ethanol concentrations approaching 5%. Productivities remain low for most yeast and particularly for fungi, but volumetric productivities exceeding 1.0 g/L-h have been reported for xylose-fermenting bacteria. In terms of wild-type microorganisms, strains of the yeast Pichia stipitis show the most promise in the short term for direct high-yield fermentation of xylose without byproduct formation. Of the recombinant xylose-fermenting microorganisms developed, recombinant E. coli ATTC 11303 (pLOI297) exhibits the most favorable performance characteristics reported to date.

  12. Prokaryotic community composition in alkaline-fermented skate (Raja pulchra).

    Science.gov (United States)

    Jang, Gwang Il; Kim, Gahee; Hwang, Chung Yeon; Cho, Byung Cheol

    2017-02-01

    Prokaryotes were extracted from skates and fermented skates purchased from fish markets and a local manufacturer in South Korea. The prokaryotic community composition of skates and fermented skates was investigated using 16S rRNA pyrosequencing. The ranges for pH and salinity of the grinded tissue extract from fermented skates were 8.4-8.9 and 1.6-6.6%, respectively. Urea and ammonia concentrations were markedly low and high, respectively, in fermented skates compared to skates. Species richness was increased in fermented skates compared to skates. Dominant and predominant bacterial groups present in the fermented skates belonged to the phylum Firmicutes, whereas those in skates belonged to Gammaproteobacteria. The major taxa found in Firmicutes were Atopostipes (Carnobacteriaceae, Lactobacillales) and/or Tissierella (Tissierellaceae, Tissierellales). A combination of RT-PCR and pyrosequencing for active bacterial composition showed that the dominant taxa i.e., Atopostipes and Tissierella, were active in fermented skate. Those dominant taxa are possibly marine lactic acid bacteria. Marine bacteria of the taxa Lactobacillales and/or Clostridia seem to be important in alkaline fermentation of skates. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Pseudomonas aeruginosa PA14 pathogenesis in Caenorhabditis elegans.

    Science.gov (United States)

    Kirienko, Natalia V; Cezairliyan, Brent O; Ausubel, Frederick M; Powell, Jennifer R

    2014-01-01

    The nematode Caenorhabditis elegans is a simple model host for studying the interaction between bacterial pathogens such as Pseudomonas aeruginosa and the metazoan innate immune system. Powerful genetic and molecular tools in both C. elegans and P. aeruginosa facilitate the identification and analysis of bacterial virulence factors as well as host defense factors. Here we describe three different assays that use the C. elegans-P. aeruginosa strain PA14 host-pathogen system. Fast Killing is a toxin-mediated death that depends on a diffusible toxin produced by PA14 but not on live bacteria. Slow Killing is due to an active infection in which bacteria colonize the C. elegans intestinal lumen. Liquid Killing is designed for high-throughput screening of chemical libraries for anti-infective compounds. Each assay has unique features and, interestingly, the PA14 virulence factors involved in killing are different in each assay.

  14. Attenuation of Pseudomonas aeruginosa virulence by quorum sensing inhibitors

    DEFF Research Database (Denmark)

    Hentzer, Morten; Wu, Hong; Andersen, Jens Bo

    2003-01-01

    Traditional treatment of infectious diseases is based on compounds that kill or inhibit growth of bacteria. A major concern with this approach is the frequent development of resistance to antibiotics. The discovery of communication systems (quorum sensing systems) regulating bacterial virulence has...... afforded a novel opportunity to control infectious bacteria without interfering with growth. Compounds that can override communication signals have been found in the marine environment. Using Pseudomonas aeruginosa PAO1 as an example of an opportunistic human pathogen, we show that a synthetic derivate...... and inhibited virulence factor expression. Application of the drug to P.aeruginosa biofilms increased bacterial susceptibility to tobramycin and SDS. In a mouse pulmonary infection model, the drug inhibited quorum sensing of the infecting bacteria and promoted their clearance by the mouse immune response....

  15. Evolution and Pathoadaptation of Pseudomonas aeruginosa in Cystic Fibrosis Patients

    DEFF Research Database (Denmark)

    Marvig, Rasmus Lykke

    understanding of how bacteria evolve and genetically adapt in a natural environment. In particular we sought to identify the genes that are targeted by mutation to optimize fitness in a given environment, and to understand the evolutionary mechanisms that govern the genetic change. Pseudomonas aeruginosa...... is the dominating pathogen of chronic airway infections in patients with cystic fibrosis (CF), and the bacterial long-term persistence in CF hosts involves mutation and selection of genetic variants with increased fitness in the CF airways. We performed a retrospective study of the P. aeruginosa DK2 clone type......, which is a transmissible clone isolated from chronically infected Danish CF patients over a period of 38 years. Whole-genome analysis of DK2 isolates enabled a finegrained reconstruction of the recent evolutionary history of the DK2 lineage and an identification of bacterial genes targeted by mutations...

  16. Filamentous Fungi Fermentation

    DEFF Research Database (Denmark)

    Nørregaard, Anders; Stocks, Stuart; Woodley, John

    2014-01-01

    Filamentous fungi (including microorganisms such as Aspergillus niger and Rhizopus oryzae) represent an enormously important platform for industrial fermentation. Two particularly valuable features are the high yield coefficients and the ability to secrete products. However, the filamentous...... morphology, together with non-Newtonian rheological properties (shear thinning), result in poor oxygen transfer unless sufficient energy is provided to the fermentation. While genomic research may improve the organisms, there is no doubt that to enable further application in future it will be necessary...... to match such research with studies of oxygen transfer and energy supply to high viscosity fluids. Hence, the implementation of innovative solutions (some of which in principle are already possible) will be essential to ensure the further development of such fermentations....

  17. Antivirulence activity of azithromycin in Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Francesco eImperi

    2014-04-01

    Full Text Available Antibiotics represent our bulwark to combat bacterial infections, but the spread of antibiotic resistance compromises their clinical efficacy. Alternatives to conventional antibiotics are urgently needed in order to complement the existing antibacterial arsenal. The macrolide antibiotic azithromycin (AZM provides a paradigmatic example of an unconventional antibacterial drug. Besides its growth-inhibiting activity, AZM displays potent anti-inflammatory properties, as well as antivirulence activity on some intrinsically resistant bacteria, such as Pseudomonas aeruginosa. In this bacterium, the antivirulence activity of AZM mainly relies on its ability to interact with the ribosome, resulting in direct and/or indirect repression of specific subsets of genes involved in virulence, quorum sensing, biofilm formation and intrinsic antibiotic resistance. Both clinical experience and clinical trials have shown the efficacy of AZM in the treatment of chronic pulmonary infections caused by P. aeruginosa. The aim of this review is to combine results from laboratory studies with evidence from clinical trials in order to unify the information on the in vivo mode of action of AZM in P. aeruginosa infection.

  18. Bioethanol Production from Fermentable Sugar Juice

    Science.gov (United States)

    Zabed, Hossain; Faruq, Golam; Sahu, Jaya Narayan; Azirun, Mohd Sofian; Hashim, Rosli; Nasrulhaq Boyce, Amru

    2014-01-01

    Bioethanol production from renewable sources to be used in transportation is now an increasing demand worldwide due to continuous depletion of fossil fuels, economic and political crises, and growing concern on environmental safety. Mainly, three types of raw materials, that is, sugar juice, starchy crops, and lignocellulosic materials, are being used for this purpose. This paper will investigate ethanol production from free sugar containing juices obtained from some energy crops such as sugarcane, sugar beet, and sweet sorghum that are the most attractive choice because of their cost-effectiveness and feasibility to use. Three types of fermentation process (batch, fed-batch, and continuous) are employed in ethanol production from these sugar juices. The most common microorganism used in fermentation from its history is the yeast, especially, Saccharomyces cerevisiae, though the bacterial species Zymomonas mobilis is also potentially used nowadays for this purpose. A number of factors related to the fermentation greatly influences the process and their optimization is the key point for efficient ethanol production from these feedstocks. PMID:24715820

  19. Bioethanol Production from Fermentable Sugar Juice

    Directory of Open Access Journals (Sweden)

    Hossain Zabed

    2014-01-01

    Full Text Available Bioethanol production from renewable sources to be used in transportation is now an increasing demand worldwide due to continuous depletion of fossil fuels, economic and political crises, and growing concern on environmental safety. Mainly, three types of raw materials, that is, sugar juice, starchy crops, and lignocellulosic materials, are being used for this purpose. This paper will investigate ethanol production from free sugar containing juices obtained from some energy crops such as sugarcane, sugar beet, and sweet sorghum that are the most attractive choice because of their cost-effectiveness and feasibility to use. Three types of fermentation process (batch, fed-batch, and continuous are employed in ethanol production from these sugar juices. The most common microorganism used in fermentation from its history is the yeast, especially, Saccharomyces cerevisiae, though the bacterial species Zymomonas mobilis is also potentially used nowadays for this purpose. A number of factors related to the fermentation greatly influences the process and their optimization is the key point for efficient ethanol production from these feedstocks.

  20. Culturable and nonculturable bacterial symbionts in the toxic benthic dinoflagellate Ostreopsis lenticularis.

    Science.gov (United States)

    Ashton, Mayra; Rosado, William; Govind, Nadathur S; Tosteson, Thomas R

    2003-09-15

    The toxic benthic dinoflagellate Ostreopsis lenticularis hosts a variety of symbiont bacterial flora. Laboratory cultured Ostreopsis clones require the presence of symbiotic Pseudomonas/Alteromonas bacterial strains for growth and toxicity development. Three culturable bacterial strains associated with Ostreopsis were identified as Pseudomonas/Alteromonas strain 1, Pseudomonas/Alteromonas strain 2 and Acinetobacter. Denaturing gradient gel electrophoresis (DGGE) analyses of extracted Ostreopsis associated bacterial DNAs indicated that there were three culturable and four non-culturable associated bacterial strains. The results presented here are the first report of the presence of unculturable bacterial symbionts in a toxic benthic dinoflagellate. Ostreopsis lost toxicity when exposed to elevated temperatures in the field and laboratory culture and subsequently recovered toxicity at reduced temperatures. Ostreopsis associated culturable Pseudomonas/Alteromonas bacterial strains were significantly reduced in dinoflagellate cultures exposed to elevated temperatures. The decreased toxicity of O. lenticularis exposed to elevated temperatures and their subsequent recovery of toxicity in periods of reduced thermal stress may have resulted from the effects of elevated temperature on the spectrum of culturable and unculturable bacterial species interacting with their Ostreopsis host.

  1. Assessment of the bacterial organisms in water from a lead-zinc ...

    African Journals Online (AJOL)

    Twenty-four (24) bulk water samples collected from a lead-zinc mining pit in Ishiagu, Ebonyi State, Nigeria over a period of 2 years were used to assess the bacterial population of the mining pit water. Nine bacterial organisms, which included Bacillus sp., Pseudomonas aeruginosa, Proteus sp., Escherichia coli, ...

  2. Common Bacterial Isolates From Infected Eyes | Ubani | Journal of ...

    African Journals Online (AJOL)

    The results yielded 333 bacterial isolates with the implicated bacteria in decreasing order of frequency as Staphylococcus aureus 80(23.70%), Staphylococcus albus 65(19.20%), Pseudomonas aeruginosa 34(10.10%), Streptococcus pneumoniae 29(8.60%), Haemophilus influenzae 26(7.70%), Streptococcus pyogene ...

  3. Bacterial adherence: the role of serum and wound fluid | Yah ...

    African Journals Online (AJOL)

    Bacteria are known to initiate wound infections and have been found associated with wound infections. The purpose of this study was to investigate the bacterial adherence potential (BAP) wounds. The bacteria used were Pseudomonas aeruginosa, Proteus mirabilis, Escherichia coli and Staphylococcus aureus isolated ...

  4. Isolation and Identification of Bacterial Species from the Human ...

    African Journals Online (AJOL)

    Isolation and Identification of Bacterial Species from the Human Gallbladders Bile of Sudanese Patients. ... On the other hand, Staphylococcus aureus and Pseudomonas spp. were less frequently isolated from bile specimens showing frequencies of 4 (4%) for each. Conclusion: The finding of this study indicated that ...

  5. Bacterial Isolates andAntibiotic Sensitivity in Community Acquired ...

    African Journals Online (AJOL)

    All patients had single conventional bacterial isolates. Streptococcus pneumoniae was the commonest isolate, found in 32 cases (64%). Klebsiella pneumoniae was the second, found in 7 cases (14%), others isolates found were Pseudomonas aeruginosa in 5 cases (10%), E coli 3cases (6%), Staphylococcus aureus in 2 ...

  6. Rapid DNA extraction of bacterial genome using laundry detergents ...

    African Journals Online (AJOL)

    Genomic DNA extraction from bacterial cells involves processes normally performed in most biological laboratories. Therefore, various methods have been offered, manually and kit, but these methods may be time consuming and costly. In this paper, genomic DNA extraction of Pseudomonas aeruginosa was investigated ...

  7. Bacterial adherence: the role of serum and wound fluid

    African Journals Online (AJOL)

    STORAGESEVER

    2008-11-05

    Nov 5, 2008 ... Bacteria are known to initiate wound infections and have been found associated with wound infections. The purpose of this study was to investigate the bacterial adherence potential (BAP) wounds. The bacteria used were Pseudomonas aeruginosa, Proteus mirabilis, Escherichia coli and Staphylococcus.

  8. Effeciency of fungal and bacterial biocontrol organisms for the ...

    African Journals Online (AJOL)

    Fungal and bacterial biocontrol organisms with known activity against soil borne fungal pathogens were tested for their efficacy in controlling Fusarium wilt of tomato in the screen house. The trial tested five organisms (Trichoderma virile, Trichoderma harzianum, Penicillium oxalicum, Bacilius subtilis and Pseudomonas ...

  9. Biodegradation of glyphosate herbicide in vitro using bacterial ...

    African Journals Online (AJOL)

    changing environment. The abilities of five bacterial species (Escherichia sp, Azotobacter sp., Alcaligenes sp., Acetobacter sp. and Pseudomonas fluorescens) to degrade glyphosate herbicide under varying environmental conditions were evaluated in this study. The isolates were screened for glyphosate utilization using ...

  10. Kinetics of Bacterial Growth on Chlorinated Aliphatic Compounds

    NARCIS (Netherlands)

    van den Wijngaard, Abraham; Wind, Richele; Janssen, Dick B.

    With the pure bacterial cultures Ancylobacter aquaticus AD20 and AD25, Xanthobacter autotrophicus GJ10, and Pseudomonas sp. strain AD1, Monod kinetics was observed during growth in chemostat cultures on 1,2-dichloroethane (AD20, AD25, and GJ10), 2-chloroethanol (AD20 and GJIO), and

  11. Bacterial Vaginosis

    Science.gov (United States)

    ... Pediatrician Health Issues Conditions Abdominal ADHD Allergies & Asthma Autism Cancer Chest & Lungs Chronic Conditions Cleft & Craniofacial Developmental ... most common vaginal infection in sexually active teenaged girls . It appears to be caused by a bacterial ...

  12. Bacterial Vaginosis

    Science.gov (United States)

    ... Archive STDs Home Page Bacterial Vaginosis (BV) Chlamydia Gonorrhea Genital Herpes Hepatitis HIV/AIDS & STDs Human Papillomavirus ( ... of getting other STDs, such as chlamydia and gonorrhea . These bacteria can sometimes cause pelvic inflammatory disease ( ...

  13. Protozoan growth rates on secondary-metabolite-producing Pseudomonas spp. correlate with high-level protozoan taxonomy

    DEFF Research Database (Denmark)

    Pedersen, Annette L.; Winding, Anne; Altenburger, Andreas

    2011-01-01

    Different features can protect bacteria against protozoan grazing, for example large size, rapid movement, and production of secondary metabolites. Most papers dealing with these matters focus on bacteria. Here, we describe protozoan features that affect their ability to grow on secondary......-metabolite-producing bacteria, and examine whether different bacterial secondary metabolites affect protozoa similarly. We investigated the growth of nine different soil protozoa on six different Pseudomonas strains, including the four secondary-metabolite-producing Pseudomonas fluorescens DR54 and CHA0, Pseudomonas...... chlororaphis MA342 and Pseudomonas sp. DSS73, as well as the two nonproducers P. fluorescens DSM50090T and P. chlororaphis ATCC43928. Secondary metabolite producers affected protozoan growth differently. In particular, bacteria with extracellular secondary metabolites seemed more inhibiting than bacteria...

  14. Biosynthesis and characterization of copolymer poly(3HB-co-3HV) from saponified Jatropha curcas oil by Pseudomonas oleovorans.

    Science.gov (United States)

    Allen, Adrian D; Anderson, Winston A; Ayorinde, Folahan O; Eribo, Broderick E

    2010-08-01

    Polyhydroxyalkanoates (PHAs) are naturally occurring biodegradable polymers with promising application in the formulation of plastic materials. PHAs are produced by numerous bacteria as energy/carbon storage materials from various substrates, including sugars and plant oils. Since these substrates compete as food sources, their use as raw material for industrial-scale production of PHA is limited. Therefore, efforts have been focused on seeking alternative sources for bacterial production of PHA. One substrate that seems to have great potential is the seed oil of Jatropha curcas plant. Among other favorable properties, J. curcas seed oil is non-edible, widely available, and can be cheaply produced. In this study, Pseudomonas oleovorans (ATCC 29347) was grown in a mineral salt medium supplemented with saponified J. curcas seed oil as the only carbon source under batch fermentation. Optimum PHA yield of 26.06% cell dry weight was achieved after 72 h. The PHA had a melting point (T(m)) between 150 and 160 degrees C. Results of polymer analyses by gas chromatography/mass spectrometry (GC/MS) identified only the methyl 3-hydroxybutanoate monomeric unit. However, electrospray ionization-time of flight mass spectroscopy (ESI-TOF MS) confirmed that the PHA was a copolymer with the characteristic HB/HV peaks at m/z 1155.49 (HB) and 1,169, 1,184-1,194 (HV). The data were further supported by 1H and 13C NMR analysis. Polymer analysis by gel permeation chromatography (GPC) indicated a peak molecular weight (MP) of 179,797, molecular weight (M(W)) of 166,838, weight number average mass (M(n)) of 131,847, and polydispersity (M(w)/M (n)) of 1.3. The data from this study indicate that J. curcas seed oil can be used as a substrate to produce the copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3HB-co-3HV).

  15. Production and characterization of rhamnolipid biosurfactant from waste frying coconut oil using a novel Pseudomonas aeruginosa D.

    Science.gov (United States)

    George, S; Jayachandran, K

    2013-02-01

    To improve biosurfactant production economics by the utilization of potential low-cost materials. In an attempt to utilize cost-effective carbon sources in the fermentative production of biosurfactants, various pure and waste frying oils were screened by a standard biosurfactant producing strain. Considering the regional significance, easy availability and the economical advantages, waste frying coconut oil was selected as the substrate for further studies. On isolation of more competent strains that could use waste frying coconut oil efficiently as a carbon source, six bacterial strains were isolated on cetyltrimethyl ammonium bromide-methylene blue agar plate, from a soil sample collected from the premises of a coconut oil mill. Among these, Pseudomonas aeruginosa D was selected as the potential producer of rhamnolipid. Spectrophotometric method, TLC, methylene blue active substance assay, drop collapse technique, surface tension measurement by Du Nouy ring method and emulsifying test confirmed the rhamnolipid producing ability of the selected strain and various process parameters were optimized for the production of maximum amount of biosurfactant. Rhamnolipid components purified and separated by ethyl acetate extraction, preparative silica gel column chromatography, HPLC and TLC were characterized by fast atom bombardment mass spectrometry as a mixture of dirhamnolipids and monorhamnolipids. The rhamnolipid homologues detected were Rha-Rha-C(10) -C(10) , Rha-C(12) -C(10) and Rha-C(10) -C(8) /Rha-C(8) -C(10) . These results indicated the possibility of waste frying coconut oil to be used as a very effective alternate substrate for the economic production of rhamnolipid by a newly isolated Ps. aeruginosa D. Results of this study throws light on the alternate use of already used cooking oil as high-energy source for producing a high value product like rhamnolipid. This would provide options for the food industry other than the recycling and reuse of waste frying

  16. Exopolysaccharides Produced by Phytopathogenic Pseudomonas syringae Pathovars in Infected Leaves of Susceptible Hosts

    Science.gov (United States)

    Fett, William F.; Dunn, Michael F.

    1989-01-01

    Bacterial exopolysaccharide (EPS) was extracted from infected leaves of several host plants inoculated with phytopathogenic strains of Pseudomonas syringae pathovars. Extraction was by a facilitated diffusion procedure or by collection of intercellular fluid using a centrifugation method. The extracted EPS was purified and characterized. All bacterial pathogens which induced watersoaked lesions on their host leaves, a characteristic of most members of this bacterial group, were found to produce alginic acid (a polymer consisting of varying ratios of mannuronic and guluronic acids). Only trace amounts of bacterial EPS could be isolated from leaves inoculated with a pathovar (pv. syringae) which does not induce the formation of lesions with a watersoaked appearance. Guluronic acid was either present in very low amounts or absent in the alginic acid preparations. All bacterial alginates were acetylated (7-11%). Levan (a fructan) was apparently not produced as an EPS in vivo by any of the pathogens tested. PMID:16666545

  17. Bacterial community dynamics during the ensilage of wilted grass.

    Science.gov (United States)

    McEniry, J; O'Kiely, P; Clipson, N J W; Forristal, P D; Doyle, E M

    2008-08-01

    Grass silage is the product formed by a natural lactic acid bacterial fermentation when grass is stored under anaerobic conditions, and represents an important ruminant feedstuff on farms during winter. Of the two commonly employed methods of ensiling forage, baled silage composition frequently differs from that of comparable precision-chop silage reflecting a different ensiling environment. The aim of this study was to investigate the dynamics of the silage fermentation in wilted grass and between ensiling systems. Fermentation dynamics were examined using traditional methods of silage analyses, including microbial enumeration and analysis of fermentation products, and culture-independent terminal restriction fragment length polymorphism (T-RFLP). A successful fermentation was achieved in both systems, with the fermentation (increase in lactic acid bacteria and lactic acid concentration, decrease in pH) proceeding rapidly once the herbage was ensiled. Under controlled conditions, little difference in silage quality and microbial composition were observed between ensiling systems and this was further reflected in the T-RFLP community analysis. T-RFLP proved a potentially useful tool to study the ensilage process and could provide valid support to traditional methods, or a viable alternative to these methods, for investigating the dynamics of the bacterial community over the course of the fermentation.

  18. Phylogenomics and systematics in Pseudomonas

    Directory of Open Access Journals (Sweden)

    Margarita eGomila

    2015-03-01

    Full Text Available The genus Pseudomonas currently contains 144 species, making it the genus of Gram-negative bacteria that contains the largest number of species. Currently, multilocus sequence analysis (MLSA is the preferred method for establishing the phylogeny between species and genera. Four partial gene sequences of housekeeping genes (16S rRNA, gyrB, rpoB and rpoD were obtained from 112 complete or draft genomes of strains related to the genus Pseudomonas that were available in databases. These genes were analyzed together with the corresponding sequences of 133 Pseudomonas type strains of validly published species to assess their correct phylogenetic assignations. We confirmed that 30% of the sequenced genomes of non-type strains were not correctly assigned at the species level in the accepted taxonomy of the genus and that 20% of the strains were not identified at the species level. Most of these strains had been isolated and classified several years ago, and their taxonomic status has not been updated by modern techniques. MLSA was also compared with indices based on the analysis of whole-genome sequences that have been proposed for species delineation, such as tetranucleotide usage patterns (TETRA, average nucleotide identity (ANIm, based on MUMmer and ANIb, based on BLAST and genome-to-genome distance (GGDC. TETRA was useful for discriminating Pseudomonas from other genera, whereas ANIb and GGDC clearly separated strains of different species. ANIb showed the strongest correlation with MLSA. The correct species classification is a prerequisite for most diversity and evolutionary studies. This work highlights the necessity for complete genomic sequences of type strains to build a phylogenomic taxonomy and that all new genome sequences submitted to databases should be correctly assigned to species to avoid taxonomic inconsistencies.

  19. Diabetic foot gangrene patient with multi-drug resistant Pseudomonas putida infection in Karawaci District, Indonesia

    Directory of Open Access Journals (Sweden)

    Nata Pratama Hardjo Lugito

    2015-01-01

    Full Text Available Pseudomonas putida is a rod-shaped, non fermenting Gram-negative organism frequently found in the environment that utilizes aerobic metabolism, previously thought to be of low pathogenicity. It had been reported as cause of skin and soft tissue infection, especially in immunocompromised patients. A female green grocer, 51 year-old came to internal medicine out-patient clinic with gangrene and osteomyelitis on her 1 st , 2 nd and 3 rd digit and wound on the sole of the right foot since 1 month prior. The patient had history of uncontrolled diabetes since a year ago. She was given ceftriaxone 2 grams b.i.d, metronidazole 500 mg t.i.d empirically and then amikacin 250 mg b.i.d, followed by amputation of the digits and wound debridement. The microorganism′s culture from pus revealed multi drug resistant Pseudomonas putida. She recovered well after antibiotics and surgery.

  20. Inhibition of Cell Differentiation in Bacillus subtilis by Pseudomonas protegens

    Science.gov (United States)

    Powers, Matthew J.; Sanabria-Valentín, Edgardo; Bowers, Albert A.

    2015-01-01

    ABSTRACT Interspecies interactions have been described for numerous bacterial systems, leading to the identification of chemical compounds that impact bacterial physiology and differentiation for processes such as biofilm formation. Here, we identified soil microbes that inhibit biofilm formation and sporulation in the common soil bacterium Bacillus subtilis. We did so by creating a reporter strain that fluoresces when the transcription of a biofilm-specific gene is repressed. Using this reporter in a coculture screen, we identified Pseudomonas putida and Pseudomonas protegens as bacteria that secrete compounds that inhibit biofilm gene expression in B. subtilis. The active compound produced by P. protegens was identified as the antibiotic and antifungal molecule 2,4-diacetylphloroglucinol (DAPG). Colonies of B. subtilis grown adjacent to a DAPG-producing P. protegens strain had altered colony morphologies relative to B. subtilis colonies grown next to a DAPG-null P. protegens strain (phlD strain). Using a subinhibitory concentration of purified DAPG in a pellicle assay, we saw that biofilm-specific gene transcription was delayed relative to transcription in untreated samples. These transcriptional changes also corresponded to phenotypic alterations: both biofilm biomass and spore formation were reduced in B. subtilis liquid cultures treated with subinhibitory concentrations of DAPG. Our results add DAPG to the growing list of antibiotics that impact bacterial development and physiology at subinhibitory concentrations. These findings also demonstrate the utility of using coculture as a means to uncover chemically mediated interspecies interactions between bacteria. IMPORTANCE Biofilms are communities of bacteria adhered to surfaces by an extracellular matrix; such biofilms can have important effects in both clinical and agricultural settings. To identify chemical compounds that inhibited biofilm formation, we used a fluorescent reporter to screen for bacteria that