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Sample records for lytic enzyme-producing microorganisms

  1. Bioremediation of Industrial Waste Through Enzyme Producing Marine Microorganisms.

    Science.gov (United States)

    Sivaperumal, P; Kamala, K; Rajaram, R

    2017-01-01

    Bioremediation process using microorganisms is a kind of nature-friendly and cost-effective clean green technology. Recently, biodegradation of industrial wastes using enzymes from marine microorganisms has been reported worldwide. The prospectus research activity in remediation area would contribute toward the development of advanced bioprocess technology. To minimize industrial wastes, marine enzymes could constitute a novel alternative in terms of waste treatment. Nowadays, the evidence on the mechanisms of bioremediation-related enzymes from marine microorganisms has been extensively studied. This review also will provide information about enzymes from various marine microorganisms and their complexity in the biodegradation of comprehensive range of industrial wastes.

  2. Effect of enzyme producing microorganisms on the biomass of epigeic earthworms (eisenia fetida) in vermicompost.

    Science.gov (United States)

    Hong, Sung Wook; Lee, Ju Sam; Chung, Kun Sub

    2011-05-01

    We analyzed the bacterial community structure of the intestines of earthworms and determined the effect of enzyme producing microorganisms on the biomass of earthworms in vermicompost. Fifty-seven bacterial 16S rDNA clones were identified in the intestines of earthworms by using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis. Entomoplasma somnilux and Bacillus licheniformis were the dominant microorganisms; other strains included Aeromonas, Bacillus, Clostridium, Ferrimonas, and uncultured bacteria. Among these strains, Photobacterium ganghwense, Aeromonas hydrophila, and Paenibacillus motobuensis were enzyme-producing microorganisms. In the mixtures that were inoculated with pure cultures of A. hydrophila WA40 and P. motobuensis WN9, the highest survival rate was 100% and the average number of earthworms, young earthworms, and cocoons were 10, 4.00-4.33, and 3.00-3.33, respectively. In addition, P. motobuensis WN9 increased the growth of earthworms and production of casts in the vermicompost. These results show that earthworms and microorganisms have a symbiotic relationship.

  3. North Western Spain hot springs are a source of lipolytic enzyme-producing thermophilic microorganisms.

    Science.gov (United States)

    Deive, Francisco J; Alvarez, María S; Sanromán, M Angeles; Longo, Maria A

    2013-02-01

    Several hot springs in Galicia (North Western Spain) have been investigated as potential sources of lipolytic enzyme-producing thermophilic microorganisms. After isolating 12 esterase producing strains, 9 of them were assured to be true lipase producers, and consequently grown in submerged cultures, obtaining high extracellular activities by two of them. Furthermore, a preliminary partial characterization of the crude lipase, obtained by ultrafiltration of the cell-free culture supernatant, was carried out at several pH and temperature values. It is outstanding that several enzymes turned out to be multiextremozymes, since they had their optimum temperature and pH at typical values from thermoalkalophiles. The thermal stability in aqueous solution of the crude enzymes was also assayed, and the influence of some potential enzyme stabilizing compounds was tested. Finally, the viability of the selected microorganisms has been demonstrated at bioreactor scale.

  4. SCREENING OF THERMOPHYLIC MICROORGANISM FROM IJEN CRATER BANYUWANGI AS PHYTASE ENZYME PRODUCER

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    Aline Puspita Kusumadjaja

    2010-06-01

    Full Text Available Phytase is enzyme which hydrolysis phytic acid to anorganic phosphate and myo-inositol pentakis-, tetrakis-, tris-, bis-, and monophosphate. The use of phytase in feed industry can overcome environment and nutrition problems which were arisen from unmetabolism phytic acid or its salt by poultry, swine and fish. The feed industry needs a thermostable enzyme due to the need of high temperature in pelleting process, i.e. 81 °C. By using thermostabile phytase, the pelleting process will not affect the enzyme activity. Thermostabile phytase can be isolated from microorganism live in hot spring water or volcano crater. In this study, the screening of thermophylic microorganism having thermostabile phytase activity in Ijen Crater, Banyuwangi, has been done. From this process, it was obtained 33 isolates that produce phytase enzyme. Isolate was code by AP-17 yields highest phytase activity, that is 0.0296 U/mL, so this isolate was choosen for further study. The activity of crude phytase enzyme was measured based on the amount of anorganic phosphate that was produced in enzymatic reaction using UV-VIS spectrophotometer at 392 nm. Based on morphology test to identify the gram type of microorganism, isolate AP-17 has a bacill cell type and identified as positive gram bacteria. This isolate was assumed as Bacillus type.   Keywords: Phytase, thermophilic microorganism, phytase activity

  5. 发酵香肠中微生物产生的酶及其作用%Enzyme Produced by Microorganism and Its Effect on Fermented Sausage

    Institute of Scientific and Technical Information of China (English)

    王海燕; 张春江; 罗欣

    2001-01-01

    本文阐述了发酵香肠中由微生物产生的硝酸还原酶、过氧化氢酶、蛋白酶和脂酶的作用%The function of nitrate reductase,hydrogen peroxidease,proteaseand lipase that produced by microorganism in fermented sausage were elaborated.

  6. Lytic enzyme production optimization using low-cost substrates and its application in the clarification of xanthan gum culture broth

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    da Silva, Cíntia Reis; Silva, Marilia Lordelo Cardoso; Kamida, Helio Mitoshi; Goes-Neto, Aristoteles; Koblitz, Maria Gabriela Bello

    2014-01-01

    Lytic enzymes are widely used in industrial biotechnology as they are able to hydrolyze the bacterial cell wall. One application of these enzymes is the clarification of the culture broth for the production of xanthan gum, because of its viability in viscous media and high specificity. The screening process for filamentous fungi producing lytic enzymes, the optimization of production of these enzymes by the selected microorganism, and the optimization of the application of the enzymes produced in the clarification of culture broth are presented in this article. Eleven fungal isolates were tested for their ability to produce enzymes able to increase the transmittance of the culture broth containing cells of Xanthomonas campestris. To optimize the secretion of lytic enzymes by the selected microorganism the following variables were tested: solid substrate, initial pH, incubation temperature, and addition of inducer (gelatin). Thereafter, secretion of the enzymes over time of incubation was assessed. To optimize the clarification process a central composite rotational design was applied in which the pH of the reaction medium, the dilution of the broth, and the reaction temperature were evaluated. The isolate identified as Aspergillus tamarii was selected for increasing the transmittance of the broth from 2.1% to 54.8%. The best conditions for cultivation of this microorganism were: use of coconut husk as solid substrate, with 90% moisture, at 30°C for 20 days. The lytic enzymes produced thereby were able to increase the transmittance of the culture broth from 2.1% to 70.6% at 65°C, without dilution and without pH adjustment. PMID:25473487

  7. Characterization and identification of enzyme-producing microflora isolated from the gut of sea cucumber Apostichopus japonicus

    Science.gov (United States)

    Li, Fenghui; Gao, Fei; Tan, Jie; Fan, Chaojing; Sun, Huiling; Yan, Jingping; Chen, Siqing; Wang, Xiaojun

    2016-01-01

    Gut microorganisms play an important role in the digestion of their host animals. The purpose of this research was to isolate and assess the enzyme-producing microbes from the Apostichopus japonicus gut. Thirty-nine strains that can produce at least one of the three digestive enzymes (protease, amylase, and cellulase) were qualitatively screened based on their extracellular enzyme-producing abilities. The enzyme-producing strains clustered into eight groups at the genetic similarity level of 100% by analyzing the restriction patterns of 16S rDNA amplified with Mbo I. Phylogenetic analysis revealed that 37 strains belonged to the genus Bacillus and two were members of the genus Virgibacillus. Enzyme-producing capability results indicate that the main enzyme-producing microflora in the A. japonicus gut was Bacillus, which can produce protease, amylase, and cellulase. Virgibacillus, however, can only produce protease. The high enzyme-producing capability of the isolates suggests that the gut microbiota play an important role in the sea cucumber digestive process.

  8. SCREENING OF THERMOPHYLIC MICROORGANISM FROM IJEN CRATER BANYUWANGI AS PHYTASE ENZYME PRODUCER

    OpenAIRE

    Kusumadjaja, Aline Puspita; Budiati, Tutuk; Puspaningsih, Ni Nyoman Tri; Sajidan, Sajidan

    2010-01-01

    Phytase is enzyme which hydrolysis phytic acid to anorganic phosphate and myo-inositol pentakis-, tetrakis-, tris-, bis-, and monophosphate. The use of phytase in feed industry can overcome environment and nutrition problems which were arisen from unmetabolism phytic acid or its salt by poultry, swine and fish. The feed industry needs a thermostable enzyme due to the need of high temperature in pelleting process, i.e. 81 °C. By using thermostabile phytase, the pelleting process will not affec...

  9. Cooperation between ligninolytic enzymes produced by superior mixed flora

    Institute of Scientific and Technical Information of China (English)

    WANG Hai-lei; LI Zong-yi; GUO Wei-yun; WANG Zhen-yu; PAN Feng

    2005-01-01

    Since the ability to degrade lignin with one kind of white-rot fungi or bacteria was very limited, superior mixed flora's ability to degrade lignin was investigated by an orthogonal experiment in this paper. The results showed that superior mixed flora reinforced the ability to degrade lignin, the degradation rates of both sample 9 and 10 were beyond 80% on the day 9. The cooperation between lignin peroxidase(LiP), Mn-dependent peroxidase(MnP) and laccase (Lac) for lignin degradation was also studied. By examining the activities of three enzymes produced by superior mixed flora, it was found that Lac was a key enzyme in the process of biological degradation of lignin but Lip was not; the enzyme activity ratios of Lac/MnP and Lac/LiP were significantly correlative with the degradation rate of lignin at the 0.01 level; and the ratio of MnP/LiP was an important factor affecting the degradation rate of lignin.

  10. The significance of cellulolytic enzymes produced by Trichoderma in opportunistic lifestyle of this fungus.

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    Strakowska, Judyta; Błaszczyk, Lidia; Chełkowski, Jerzy

    2014-07-01

    The degradation of native cellulose to glucose monomers is a complex process, which requires the synergistic action of the extracellular enzymes produced by cellulolytic microorganisms. Among fungi, the enzymatic systems that can degrade native cellulose have been extensively studied for species belonging to the genera of Trichoderma. The majority of the cellulolytic enzymes described so far have been examples of Trichoderma reesei, extremely specialized in the efficient degradation of plant cell wall cellulose. Other Trichoderma species, such as T. harzianum, T. koningii, T. longibrachiatum, and T. viride, known for their capacity to produce cellulolytic enzymes, have been isolated from various ecological niches, where they have proved successful in various heterotrophic interactions. As saprotrophs, these species are considered to make a contribution to the degradation of lignocellulosic plant material. Their cellulolytic potential is also used in interactions with plants, especially in plant root colonization. However, the role of cellulolytic enzymes in species forming endophytic associations with plants or in those existing in the substratum for mushroom cultivation remains unknown. The present review discusses the current state of knowledge about cellulolytic enzymes production by Trichoderma species and the encoding genes, as well as the involvement of these proteins in the lifestyle of Trichoderma.

  11. Purification and characterization of an acidothermophilic cellulase enzyme produced by Bacillus subtilis strain LFS3.

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    Rawat, Rekha; Tewari, Lakshmi

    2012-07-01

    In the present investigation, a microorganism hydrolyzing carboxymethylcellulose (CMC) was isolated and identified as Bacillus subtilis strain LFS3 by 16S rDNA sequence analysis. The carboxymethylcellulase (CMCase) enzyme produced by the B. subtilis strain LFS3 was purified by (NH₄)₂SO₄ precipitation, ion exchange and gel filtration chromatography, with an overall recovery of 15 %. Native-PAGE analysis of purified CMCase revealed the molecular weight of enzyme to be about 185 kDa. The activity profile of CMCase enzyme showed the optimum activity at temperature 60 °C and pH 4.0, respectively. The enzyme activity was induced by Na⁺, Mg²⁺, NH₄⁺, and EDTA, whereas strongly inhibited by Hg²⁺ and Fe³⁺. The purified enzyme hydrolyzed CMC, filter paper, and xylan, but not p-nitrophenyl β-D-glucopyranoside and cellulose. Kinetic analysis of purified enzyme showed the K(m) value of 2.2 mg/ml. Thus, acidophilic as well as thermophilic nature makes this cellulase a suitable candidate for current mainstream biomass conversion into fuel and other industrial processes.

  12. Phage lytic enzymes: a history

    Institute of Scientific and Technical Information of China (English)

    David; Trudil

    2015-01-01

    There are many recent studies regarding the efficacy of bacteriophage-related lytic enzymes: the enzymes of ‘bacteria-eaters’ or viruses that infect bacteria. By degrading the cell wall of the targeted bacteria, these lytic enzymes have been shown to efficiently lyse Gram-positive bacteria without affecting normal flora and non-related bacteria. Recent studies have suggested approaches for lysing Gram-negative bacteria as well(Briersa Y, et al., 2014). These enzymes include: phage-lysozyme, endolysin, lysozyme, lysin, phage lysin, phage lytic enzymes, phageassociated enzymes, enzybiotics, muralysin, muramidase, virolysin and designations such as Ply, PAE and others. Bacteriophages are viruses that kill bacteria, do not contribute to antimicrobial resistance, are easy to develop, inexpensive to manufacture and safe for humans, animals and the environment. The current focus on lytic enzymes has been on their use as anti-infectives in humans and more recently in agricultural research models. The initial translational application of lytic enzymes, however, was not associated with treating or preventing a specifi c disease but rather as an extraction method to be incorporated in a rapid bacterial detection assay(Bernstein D, 1997).The current review traces the translational history of phage lytic enzymes–from their initial discovery in 1986 for the rapid detection of group A streptococcus in clinical specimens to evolving applications in the detection and prevention of disease in humans and in agriculture.

  13. Characterization of cellulase enzyme produced by Chaetomium sp. isolated from books and archives

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    Moza Mohammed AL-Kharousi

    2015-12-01

    Full Text Available Background: Cellulase is an important industrial enzyme used to degrade cellulosic biomass. The demand for cellulase enzyme is continuously increasing because of its applications in various industries. Hence, screening of cellulase producing microorganisms from different sources has gained significant importance. Material and Methods: In this study, fungi isolated from books and archives were screened for their cellulase producing abilities. Four different fungi were isolated from books and archives using potato dextrose agar. Screening of these isolates for cellulase production was carried out using carboxymethyl cellulose broth. The most efficient fungus was subjected to cellulase fermentation and enzymes produced were purified and partially characterized. Results: Four different fungi, Chaetomium sp., Aspergillus niger, Aspergillus nidulans and Penicillium sp., were isolated from books and archives. All the isolates were tested for their ability to producecellulase enzyme. During the primary screening Chaetomium sp. showed good growth and highercellulase activity (155.3±25.6 U/mL in carboxymethyl cellulose medium than the other fungi. The cellulase fermentation study was conducted with Chaetomium sp. using carboxymethyl cellulose asa substrate. During the stationary phase (144 h of the growth, the cellulase activity of Chaetomium sp. was significantly high. The maximum mycelial weight of this fungi was obtained at 168 h. Viscosity of the Chaetomium sp. inoculated fermentation medium continuously decreased until 144 h because of the degradation of carboxymethyl cellulose. During cellulase fermentation, pHincreased from the initial neutral pH to 8.5. Purified cellulase showed a specific activity of 7.3 U/mg. It exhibited maximum activity at 20°C and was stable between pH 5 and 9. Conclusions: Books and archives could be a good source for the isolation of cellulase producing fungi.

  14. The novel Shewanella putrefaciens-infecting bacteriophage Spp001: genome sequence and lytic enzymes.

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    Han, Feng; Li, Meng; Lin, Hong; Wang, Jingxue; Cao, Limin; Khan, Muhammad Naseem

    2014-06-01

    Shewanella putrefaciens has been identified as a specific spoilage organism commonly found in chilled fresh fish, which contributes to the spoilage of fish products. Limiting S. putrefaciens growth can extend the shelf-life of chilled fish. Endolysins, which are lytic enzymes produced by bacteriophages, have been considered an alternative to control bacterial growth, and have been useful in various applications, including food preservation. We report here, for the first time, the complete genome sequence of a novel phage Spp001, which lyses S. putrefaciens Sp225. The Spp001 genome comprises a 54,789-bp DNA molecule with 67 open reading frames and an average total G + C content of 49.42 %. In silico analysis revealed that the Spp001 open reading frames encode various putative functional proteins, including an endolysin (ORF 62); however, no sequence for genes encoding the holin polypeptides, which work in concert with endolysins, was identified. To examine further the lytic activity of Spp001, we analyzed the lytic enzyme-containing fraction from phages released at the end of the phage lytic cycle in S. putrefaciens, using diffusion and turbidimetric assays. The results show that the partially purified extract contained endolysin, as indicated by a high hydrolytic activity towards bacterial peptidoglycan decrease in the OD590 value by 0.160 in 15 min. The results will allow further investigation of the purification of natural Spp001 endolysin, the extension of Spp001 host range, and the applications of the phage-encoded enzymes.

  15. The rhizosphere priming effect explained by microscale interactions among enzyme producing microbes

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    Kaiser, Christina; Dieckmann, Ulf; Franklin, Oskar

    2017-04-01

    Addition of small amounts of labile carbon (C), for example by root exudations, have been found to accelerate soil organic matter decomposition ('Priming Effect'). Possible explanations that have been suggested so far are that this C increases microbial turnover or - by increasing nitrogen (N) limitation of microbes - triggers increased mining of microbes for nutrients. Individual-based modeling of microbes at the microscale offer a new and alternative explanation for the emergence of the priming effect: Enzyme producing microbes benefit from proximity to other enzyme producing microbes since this increases their return of investment for each enzyme produced. The benefit grows the more microbes are close to each other, such that growth of a patch of microbes becomes a self-enhancing process. Our results show that there is a 'tipping point' - a critical size of such a patch, or number of spatially related microbes, which is necessary to start this process. In a model setting where soil microbes are C limited and thus only grow slowly, the addition of a small amount of labile C in a certain area is sufficient to trigger the emergence of such a growing microbial patch which consequently increases long-term decomposition rates of soil organic matter far beyond the initial labile C input in the model.

  16. Screening Of the Association of Aspergillusfungi – Macerase and Cellulase Enzymes Producers

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    R.K.Bliyeva,; Zh.B.Suleimenova

    2015-01-01

    In nature, the destruction of plant wastes takes place by not a single microorganism, butby complex of microorganisms which belong to different species and genera with complex of enzymes. Using of highly active monocultures to createfungal association which produce multifunctional enzymeswith desired properties is a promising approach to create relevant and effective crop production microorganisms with beneficial properties. Among15 industrial micro my cetes the most active associ...

  17. Enzymatic hydrolysis of steam-pretreated lignocellulosic materials with Trichoderma atroviride enzymes produced in-house

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    Macrelli Stefano

    2009-07-01

    Full Text Available Abstract Background Improvement of the process of cellulase production and development of more efficient lignocellulose-degrading enzymes are necessary in order to reduce the cost of enzymes required in the biomass-to-bioethanol process. Results Lignocellulolytic enzyme complexes were produced by the mutant Trichoderma atroviride TUB F-1663 on three different steam-pretreated lignocellulosic substrates, namely spruce, wheat straw and sugarcane bagasse. Filter paper activities of the enzymes produced on the three materials were very similar, while β-glucosidase and hemicellulase activities were more dependent on the nature of the substrate. Hydrolysis of the enzyme preparations investigated produced similar glucose yields. However, the enzymes produced in-house proved to degrade the xylan and the xylose oligomers less efficiently than a commercial mixture of cellulase and β-glucosidase. Furthermore, accumulation of xylose oligomers was observed when the TUB F-1663 supernatants were applied to xylan-containing substrates, probably due to the low β-xylosidase activity of the enzymes. The efficiency of the enzymes produced in-house was enhanced by supplementation with extra commercial β-glucosidase and β-xylosidase. When the hydrolytic capacities of various mixtures of a commercial cellulase and a T. atroviride supernatant produced in the lab were investigated at the same enzyme loading, the glucose yield appeared to be correlated with the β-glucosidase activity, while the xylose yield seemed to be correlated with the β-xylosidase level in the mixtures. Conclusion Enzyme supernatants produced by the mutant T. atroviride TUB F-1663 on various pretreated lignocellulosic substrates have good filter paper activity values combined with high levels of β-glucosidase activities, leading to cellulose conversion in the enzymatic hydrolysis that is as efficient as with a commercial cellulase mixture. On the other hand, in order to achieve good xylan

  18. [Isolation of protoplasts from vegetable tissues using extracellular lytic enzymes from fusarium oxysporum f.sp. melonis].

    Science.gov (United States)

    Alconada, T M; Martínez, M J

    1995-01-01

    Fusarium oxysporum f.sp. melonis, a pathogen of melon (Cucumis melo L.), was grown in shaken cultures at 26 degrees C in a mineral salts medium containing glucose, xylan and apple pectin as carbon sources. The extracellular enzymic complex obtained from these cultures showed lytic activity on plant tissues, causing maceration of melon fruits, potato tubers and carrot roots. Protoplasts were isolated from melon fruits when the maceration was carried out under appropriate osmotic conditions. This fact suggest a possible relationship between the enzymes produced by Fusarium oxysporum f.sp. melonis and their pathogenicity on melon plants.

  19. Screening Of the Association of Aspergillusfungi – Macerase and Cellulase Enzymes Producers

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    R.K.Bliyeva,

    2015-08-01

    Full Text Available In nature, the destruction of plant wastes takes place by not a single microorganism, butby complex of microorganisms which belong to different species and genera with complex of enzymes. Using of highly active monocultures to createfungal association which produce multifunctional enzymeswith desired properties is a promising approach to create relevant and effective crop production microorganisms with beneficial properties. Among15 industrial micro my cetes the most active association was from Aspergillusniger 355 and Aspergillusawamori 1-8 which had highmacerase and cellulase enzymes activity.

  20. DETERMINATION OF ENZYMES PRODUCED BY CERIPORIOPSIS SUBVERMISPORA DURING PRETREATMENT OF DIFFERENT BIOMASS SOURCES

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    Miroslav Ondrejovič

    2012-02-01

    Full Text Available The aim of this paper was to study of lignocellulolytic enzymes producing by Ceriporiopsis subvermispora during its cultivation on three types of plant biomass differentiated by chemical composition and physical properties (wheat straw, pine and poplar wood. The activity of lignocellulolytic enzymes in cultivation medium was determined by catalytic transformation of their natural substrates to products which were detected by photometric methods. Cellulase activities were very low while xylanases predominated. Wheat straw was best substrate for production of cellulases (4.38 U/mL and xylanases (23.34 U/mL. The maximum activity of cellulase and xylanase was reached at 8th and 3rd day, respectively. Laccase activity reached the maximum after 16 days and then gradually decreased. The best substrate for production of laccases was poplar wood (1.67 U/mL.

  1. Heterologous overproduction of β-fructofuranosidase from yeast Xanthophyllomyces dendrorhous, an enzyme producing prebiotic sugars.

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    Gimeno-Pérez, María; Linde, Dolores; Fernández-Arrojo, Lucía; Plou, Francisco J; Fernández-Lobato, María

    2015-04-01

    The β-fructofuranosidase Xd-INV from the yeast Xanthophyllomyces dendrorhous is the largest microbial enzyme producing neo-fructooligosaccharides (neo-FOS) known to date. It mainly synthesizes neokestose and neonystose, oligosaccharides with potentially improved prebiotic properties. The Xd-INV gene comprises an open reading frame of 1995 bp, which encodes a 665-amino acid protein. Initial N-terminal sequencing of Xd-INV pointed to a majority extracellular protein of 595 amino acids lacking the first 70 residues (potential signal peptide). Functionality of the last 1785 bp of Xd-INV gene was previously proved in Saccharomyces cerevisiae but only weak β-fructofuranosidase activity was quantified. In this study, different strategies to improve this enzyme level in a heterologous system have been used. Curiously, best results were obtained by increasing the protein N-terminus sequence in 39 amino acids, protein of 634 residues. The higher β-fructofuranosidase activity detected in this study, about 15 U/mL, was obtained using Pichia pastoris and represents an improvement of about 1500 times the level previously obtained in a heterologous organism and doubles the best level of activity obtained by the natural producer. Heterologously expressed protein was purified and characterized biochemically and kinetically. Except by its glycosylation degree (10 % lower) and thermal stability (4-5 °C lower in the 60-85 °C range), the properties of the heterologous enzyme, including ability to produce neo-FOS, remained unchanged. Interestingly, besides the neo-FOS referred before blastose was also detected (8-22 g/L) in the reaction mixtures, making Xd-INV the first yeast enzyme producing this non-conventional disaccharide reported to date.

  2. Lytic to temperate switching of viral communities

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    Knowles, B.; Silveira, C. B.; Bailey, B. A.; Barott, K.; Cantu, V. A.; Cobián-Güemes, A. G.; Coutinho, F. H.; Dinsdale, E. A.; Felts, B.; Furby, K. A.; George, E. E.; Green, K. T.; Gregoracci, G. B.; Haas, A. F.; Haggerty, J. M.; Hester, E. R.; Hisakawa, N.; Kelly, L. W.; Lim, Y. W.; Little, M.; Luque, A.; McDole-Somera, T.; McNair, K.; de Oliveira, L. S.; Quistad, S. D.; Robinett, N. L.; Sala, E.; Salamon, P.; Sanchez, S. E.; Sandin, S.; Silva, G. G. Z.; Smith, J.; Sullivan, C.; Thompson, C.; Vermeij, M. J. A.; Youle, M.; Young, C.; Zgliczynski, B.; Brainard, R.; Edwards, R. A.; Nulton, J.; Thompson, F.; Rohwer, F.

    2016-03-01

    Microbial viruses can control host abundances via density-dependent lytic predator-prey dynamics. Less clear is how temperate viruses, which coexist and replicate with their host, influence microbial communities. Here we show that virus-like particles are relatively less abundant at high host densities. This suggests suppressed lysis where established models predict lytic dynamics are favoured. Meta-analysis of published viral and microbial densities showed that this trend was widespread in diverse ecosystems ranging from soil to freshwater to human lungs. Experimental manipulations showed viral densities more consistent with temperate than lytic life cycles at increasing microbial abundance. An analysis of 24 coral reef viromes showed a relative increase in the abundance of hallmark genes encoded by temperate viruses with increased microbial abundance. Based on these four lines of evidence, we propose the Piggyback-the-Winner model wherein temperate dynamics become increasingly important in ecosystems with high microbial densities; thus ‘more microbes, fewer viruses’.

  3. Lytic clavicular lesions in fibromatosis colli

    Energy Technology Data Exchange (ETDEWEB)

    Sartoris, D.J.; Parker, B.R.; Mochizuki, R.M.

    1983-06-01

    Two patients with fibromatosis colli (congenital torticollis) presented with lytic lesions in the clavicle at the insertion of the fibrosed clavicular head of the sternocleidomastoid muscle. Biopsy of one lesion showed intraosseous fibrosis. These lesions are probably not uncommon but radiographs are rarely performed in uncomplicated cases.

  4. Ultrasound-assisted extraction and characterization of hydrolytic and oxidative enzymes produced by solid state fermentation.

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    Szabo, Orsolya Erzsebet; Csiszar, Emilia; Toth, Karolina; Szakacs, George; Koczka, Bela

    2015-01-01

    Ligninolytic and hydrolytic enzymes were produced with six selected fungi on flax substrate by solid state fermentation (SSF). The extracellular enzyme production of the organisms in two SSF media was evaluated by measuring the soluble protein concentration and the filter paper, endoxylanase, 1,4-β-d-glucosidase, 1,4-β-d-endoglucanase, polygalacturonase, lignin peroxidase, manganese peroxidase and laccase activities of the clear culture solutions produced by conventional extraction from the SSF materials. The SSF material of the best enzyme producer (Trichoderma virens TUB F-498) was further investigated to enhance the enzyme recovery by low frequency ultrasound treatment. Performance of both the original and ultrasound macerated crude enzyme mixtures was evaluated in degradation of the colored lignin-containing and waxy materials of raw linen fabric. Results proved that sonication (at 40%, 60% and 80% amplitudes, for 60min) did not result in reduction in the filter paper, lignin peroxidase and laccase activities of the crude enzyme solution, but has a significant positive effect on the efficiency of enzyme extraction from the SSF material. Depending on the parameters of sonication, the enzyme activities in the extracts obtained can be increased up to 129-413% of the original activities measured in the control extracts recovered by a common magnetic stirrer. Sonication also has an effect on both the enzymatic removal of the lignin-containing color materials and hydrophobic surface layer from the raw linen.

  5. Testing protozoacidal activity of ligand-lytic peptides against termite gut protozoa in vitro (protozoa culture) and in vivo (microinjection into termite hindgut).

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    Husseneder, Claudia; Sethi, Amit; Foil, Lane; Delatte, Jennifer

    2010-12-29

    We are developing a novel approach to subterranean termite control that would lead to reduced reliance on the use of chemical pesticides. Subterranean termites are dependent on protozoa in the hindguts of workers to efficiently digest wood. Lytic peptides have been shown to kill a variety of protozoan parasites (Mutwiri et al. 2000) and also protozoa in the gut of the Formosan subterranean termite, Coptotermes formosanus (Husseneder and Collier 2009). Lytic peptides are part of the nonspecific immune system of eukaryotes, and destroy the membranes of microorganisms (Leuschner and Hansel 2004). Most lytic peptides are not likely to harm higher eukaryotes, because they do not affect the electrically neutral cholesterol-containing cell membranes of higher eukaryotes (Javadpour et al. 1996). Lytic peptide action can be targeted to specific cell types by the addition of a ligand. For example, Hansel et al. (2007) reported that lytic peptides conjugated with cancer cell membrane receptor ligands could be used to destroy breast cancer cells, while lytic peptides alone or conjugated with non-specific peptides were not effective. Lytic peptides also have been conjugated to human hormones that bind to receptors on tumor cells for targeted destruction of prostate and testicular cancer cells (Leuschner and Hansel 2004). In this article we present techniques used to demonstrate the protozoacidal activity of a lytic peptide (Hecate) coupled to a heptapeptide ligand that binds to the surface membrane of protozoa from the gut of the Formosan subterranean termite. These techniques include extirpation of the gut from termite workers, anaerobic culture of gut protozoa (Pseudotrichonympha grassii, Holomastigotoides hartmanni,Spirotrichonympha leidyi), microscopic confirmation that the ligand marked with a fluorescent dye binds to the termite gut protozoa and other free-living protozoa but not to bacteria or gut tissue. We also demonstrate that the same ligand coupled to a lytic

  6. Mycolytic enzymes produced by Streptomyces violaceusniger and their role in antagonism towards wood-rotting fungi.

    Science.gov (United States)

    Nagpure, Anand; Choudhary, Bharti; Gupta, Rajinder K

    2014-05-01

    Extracellular mycolytic enzymes produced under submerged fermentation by the fungal antagonist Streptomyces violaceusniger MTCC 3959 were characterized. This streptomycete produced higher amounts of extracellular chitinase and protease during late exponential phase, whereas β-1,3-glucanase production was at peak in mid-stationary phase. Cell-free culture filtrate (CCF) exhibited a broad range of antifungal activity against both white rot and brown rot fungi. The inhibitory activity was completely lost after treatment with proteinase K and heat, indicating that extracellular antifungal metabolites are heat labile and proteinaceous in nature. Optimum pH and temperature for enzyme activity were: 9.0 and 60 °C for chitinase; 6.0 and 60 °C for β-1,3-glucanase; and 9.0 and 70 °C for protease. Mycolytic enzymes were moderately thermostable, and had a wide pH stability range extending from pH 5.0 to 10.0. The zymogram analysis of CCF revealed five chitinase isoenzymes with an apparent molecular weight of 20.8, 33.3, 45.6, 67.4, and 114.8 kDa, one β-1,3-glucanase appeared as a single band of ∼131.8 kDa and four protease isoenzymes with approximate molecular weights of 22.8, 62.52, 74.64, and 120.5 kDa. S. violaceusniger MTCC 3959 produced mycolytic enzymes that can be effectively used for suppression of phytopathogenic basidiomycetes. It has the potential to be an effective biofungicide.

  7. The Study of Natural Isolates of Fusarium spp. Micromycetes – Ligninolytic Enzymes Producers

    Directory of Open Access Journals (Sweden)

    I.V. Darmov

    2017-03-01

    Full Text Available It is known that many basidiomycetes, white rot agents of wood in particular, produce ligninolytic complex enzymes, the most important of which are laccase, manganese peroxidase, and lignin peroxidase. Using these basidiomycete enzymes, promising methods have been developed for disposal of logging and plant farming wastes, paper stock delignification, cloth bio-bleaching, and production of wooden fibreboards; however, these techniques are not commonly applied on an industrial scale. It should be noted that wood lignin can be also destructed by various micromycetes, such as Fusarium, Trichoderma, Aspergillus, Penicillium, etc. Nevertheless, the range of ligninolytic complex enzymes produced by them, as well as the level of their activity and localization in a cell, have been studied insufficiently. Thus, it is not possible to fully appreciate the ligninolytic potential of micromycetes. The purpose of this research is to evaluate the ability of natural isolates of Fusarium spp. to produce laccase, manganese peroxidase, and lignin peroxidase. Furthermore, the level of activity of these enzymes in the culture liquid and cell mass of producers has been determined. The following natural isolates of micromycetes have been isolated and identified from natural envi-ronments of the Kirov region: F. culmorum, strain 3, F. sporotrichioides, strain 12, and F. solani, strain 52, all capable of degradation of wood lignin and carrying simultaneously genetic determinants of all the three major ligninolytic enzymes – laccase, manganese peroxidase, and lignin peroxidase. We have studied the dynamics of the activity of these enzymes in the culture liquid supernatants at deep micromycete cultivation. The enzyme activity has been determined by the spectrophotometric method. In terms of laccase and manganese peroxidase production, two micromycete strains – F. culmorum 3 and F. sporotrichioides 12 – have been almost as good as the basidiomycete T. versicolor

  8. Percutaneous aspiration biopsy in cervical spine lytic lesions. Indications and technique

    Energy Technology Data Exchange (ETDEWEB)

    Tampieri, D.; Weill, A.; Melanson, D.; Ethier, R. (Montreal Neurological Inst. and Hospital, PQ (Canada). Dept. of Neuroradiology)

    1991-02-01

    We describe the technique and the results of the percutaneous aspiration biopsy (PAB) in a series of 9 patients presenting with neck pain and different degrees of myelopathy, in whom the cervical spine X-ray demonstrated lytic lesions of unknown origin. PAB is a useful, relatively safe technique, and leads to histological diagnosis between metastatic and inflammatory processes. Furthermore, in inflammatory lesions with negative hemoculture, PAB may help in detecting the micro-organism responsible and therefore allow a better antibiotic treatment. (orig.).

  9. Microorganism Billiards

    CERN Document Server

    Wahl, Colin; Spagnolie, Saverio E; Thiffeault, Jean-Luc

    2015-01-01

    Recent experiments and numerical simulations have shown that certain types of microorganisms "reflect" off of a flat surface at a critical angle of departure, independent of the angle of incidence. The nature of the reflection may be active (cell and flagellar contact with the surface) or passive (hydrodynamic) interactions. We explore the billiard-like motion of such a body inside a regular polygon and show that the dynamics can settle on a stable periodic orbit, or can be chaotic, depending on the swimmer's departure angle and the domain geometry. The dynamics are often found to be robust to the introduction of weak random fluctuations. The Lyapunov exponent of swimmer trajectories can be positive or negative, can have extremal values, and can have discontinuities depending on the degree of the polygon. A passive sorting device is proposed that traps swimmers of different departure angles into separate bins. We also study the external problem of a microorganism swimming in a patterned environment of square ...

  10. Effect of temperature on the production of cellulases, xylanases and lytic enzymes by selected Trichoderma reesei mutants

    Directory of Open Access Journals (Sweden)

    Piotr Janas

    2014-08-01

    Full Text Available The effect of temperature in the rangę of 26-38°C on the production of cellulases, xylanases and lytic enzymes by four mutant strains of Trichoderma reesei was analysed. On the basis of these investigations three thermosensitive strains (M-7. RUT C 30 and VTT-D-78085 which showed reduced excretion of the above mentioned enzymes as well as protein and a thermoresistant mutant (VTT-D-79I24 which grew within a temperature range of 26-34°C were characterized. Higher temperature caused an increase in the level of xylanolytic enzymes produced by the four mutants. In addition. it effected the complex composition of cellulolytic enzymes secreted by VTT-D-79l 24 (i.c. increased and reduced excertion of (β-glucosidase and β-1,4-endoglucanase respectively.

  11. Microorganism billiards

    Science.gov (United States)

    Spagnolie, Saverio E.; Wahl, Colin; Lukasik, Joseph; Thiffeault, Jean-Luc

    2017-02-01

    Recent experiments and numerical simulations have shown that certain types of microorganisms "reflect" off of a flat surface at a critical angle of departure, independent of the angle of incidence. The nature of the reflection may be active (cell and flagellar contact with the surface) or passive (hydrodynamic) interactions. We explore the billiard-like motion of a body with this empirical reflection law inside a regular polygon and show that the dynamics can settle on a stable periodic orbit or can be chaotic, depending on the swimmer's departure angle and the domain geometry. The dynamics are often found to be robust to the introduction of weak random fluctuations. The Lyapunov exponent of swimmer trajectories can be positive or negative, can have extremal values, and can have discontinuities depending on the degree of the polygon. A passive sorting device is proposed that traps swimmers of different departure angles into separate bins. We also study the external problem of a microorganism swimming in a patterned environment of square obstacles, where the departure angle dictates the possibility of trapping or diffusive trajectories.

  12. Lignite microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Bulankina, M.A.; Lysak, L.V.; Zvyagintsev, D.G. [Moscow MV Lomonosov State University, Moscow (Russian Federation). Faculty of Soil Science

    2007-03-15

    The first demonstration that samples of lignite at a depth of 10 m are considerably enriched in bacteria is reported. According to direct microscopy, the abundance of bacteria was about 10{sup 7} cells/g. About 70% of cells had intact cell membranes and small size, which points to their anabiotic state. The fungal mycelium length was no more than 1 m. Lignite inoculation onto solid glucose-yeast-peptone medium allowed us to isolate bacteria of the genera Bacillus, Rhodococcus, Arthrobacter, Micrococcus, Spirillum, and Cytophaga. Representatives of the genera Penicillium and Trichoderma were identified on Czapek medium. Moistening of lignite powder increased the microbial respiration rate and microbial and fungal abundance but did not increase their generic diversity. This finding suggests that the studied microorganisms are autochthonous to lignite.

  13. Viral reproductive strategies: How can lytic viruses be evolutionarily competitive?

    Science.gov (United States)

    Komarova, Natalia L

    2007-12-21

    Viral release strategies can be roughly classified as lytic (the ones that accumulate inside the host cell and exit in a burst, killing the cell), and budding (the ones that are produced and released from the host cell gradually). Here we study the evolutionary competition between the two strategies. If all the parameters, such as the rate of viral production, cell life-span and the neutralizing capacity of the antibodies, were the same for lytic and budding viruses, the budding life-strategy would have a large evolutionary advantage. The question arises what makes lytic viruses evolutionarily competitive. We propose that it is the different removal capacity of the antibodies against budding and lytic virions. The latter exit the cell in a large burst such that the antibodies are "flooded" and a larger proportion of virions can escape the immune system and spread to new cells. We create two spatial models of virus-antibody interaction and show that for realistic parameter values, the effect of antibody flooding can indeed take place. We also argue that the lytic life cycle, including a relatively large burst-size, has evolved to promote survival in the face of antibody attack. According to the calculations, in the absence of efficient antibodies, the optimal burst size of lytic viruses would be only a few virus particles, as opposed to the observed 10(2)-10(5) viral particles. Similarly, there is an evolutionary pressure to extend the life-span as a response to antibody action.

  14. Lytic and non-lytic permeabilization of cardiolipin-containing lipid bilayers induced by cytochrome C.

    Directory of Open Access Journals (Sweden)

    Jian Xu

    Full Text Available The release of cytochrome c (cyt c from mitochondria is an important early step during cellular apoptosis, however the precise mechanism by which the outer mitochondrial membrane becomes permeable to these proteins is as yet unclear. Inspired by our previous observation of cyt c crossing the membrane barrier of giant unilamellar vesicle model systems, we investigate the interaction of cyt c with cardiolipin (CL-containing membranes using the innovative droplet bilayer system that permits electrochemical measurements with simultaneous microscopy observation. We find that cyt c can permeabilize CL-containing membranes by induction of lipid pores in a dose-dependent manner, with membrane lysis eventually observed at relatively high (µM cyt c concentrations due to widespread pore formation in the membrane destabilizing its bilayer structure. Surprisingly, as cyt c concentration is further increased, we find a regime with exceptionally high permeability where a stable membrane barrier is still maintained between droplet compartments. This unusual non-lytic state has a long lifetime (>20 h and can be reversibly formed by mechanically separating the droplets before reforming the contact area between them. The transitions between behavioural regimes are electrostatically driven, demonstrated by their suppression with increasing ionic concentrations and their dependence on CL composition. While membrane permeability could also be induced by cationic PAMAM dendrimers, the non-lytic, highly permeable membrane state could not be reproduced using these synthetic polymers, indicating that details in the structure of cyt c beyond simply possessing a cationic net charge are important for the emergence of this unconventional membrane state. These unexpected findings may hold significance for the mechanism by which cyt c escapes into the cytosol of cells during apoptosis.

  15. Painful Lytic Lesions of the Foot : A Case Report

    Directory of Open Access Journals (Sweden)

    R Vaishya

    2015-03-01

    Full Text Available The presence of lytic lesions in the bones of foot raises a number of diagnostic possibilities ranging from infection, inflammatory pathology to neoplastic conditions. Although the radiological picture is not pathognomonic of any pathology, clinical history and histopathological examination can help to clinch the diagnosis. We present a case of multiple lytic lesions of the foot and discuss possible differential diagnoses. The patient was diagnosed as a case of madura foot and the lesions responded to surgical debridement and anti-fungal treatment with a good functional outcome. Madura foot is an uncommon, chronic granulomatous fungal or bacterial infection with a predilection in people who walk barefoot. Although known for a specific geographical distribution, madura foot should be kept as a possible diagnosis in patients presenting with lytic lesions of the foot due to population emigration across the world.

  16. Comparative genomics of citric-acid producing Aspergillus niger ATCC 1015 versus enzyme-producing CBS 513.88

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Mikael R.; Salazar, Margarita; Schaap, Peter; van de Vondervoort, Peter; Culley, David E.; Thykaer, Jette; Frisvad, Jens C.; Nielsen, Kristian F.; Albang, Richard; Albermann, Kaj; Berka, Randy; Braus, Gerhard; Braus-Stromeyer, Susanna A.; Corrochano, Luis; Dai, Ziyu; van Dijck, Piet; Hofmann, Gerald; Lasure, Linda L.; Magnuson, Jon K.; Menke, Hildegard; Meijer, Martin; Meijer, Susan; Nielsen, Jakob B.; Nielsen, Michael L.; van Ooyen, Albert; Pel, Herman J.; Poulsen, Lars; Samson, Rob; Stam, Hein; Tsang, Adrian; van den Brink, Johannes M.; ATkins, Alex; Aerts, Andrea; Shapiro, Harris; Pangilinan, Jasmyn; Salamov, Asaf; Lou, Yigong; Lindquist, Erika; Lucas, Susan; Grimwood, Jane; Grigoriev, Igor V.; Kubicek, Christian P.; Martinez, Diego; van Peij, Noel; Roubos, Johannes A.; Nielsen, Jens B.; Baker, Scott E.

    2011-06-01

    The filamentous fungus Aspergillus niger exhibits great diversity in its phenotype. It is found globally, both as marine and terrestrial strains, produces both organic acids and hydrolytic enzymes in high amounts, and some isolates exhibit pathogenicity. Although the genome of an industrial enzyme-producing A. niger strain (CBS 513.88) has already been sequenced, the versatility and diversity of this species compels additional exploration. We therefore undertook whole genome sequencing of the acidogenic A. niger wild type strain (ATCC 1015), and produced a genome sequence of very high quality. Only 15 gaps are present in the sequence and half the telomeric regions have been elucidated. Moreover, sequence information from ATCC 1015 was utilized to improve the genome sequence of CBS 513.88. Chromosome-level comparisons uncovered several genome rearrangements, deletions, a clear case of strain-specific horizontal gene transfer, and identification of 0.8 megabase of novel sequence. Single nucleotide polymorphisms per kilobase (SNPs/kb) between the two strains were found to be exceptionally high (average: 7.8, maximum: 160 SNPs/kb). High variation within the species was confirmed with exo-metabolite profiling and phylogenetics. Detailed lists of alleles were generated, and genotypic differences were observed to accumulate in metabolic pathways essential to acid production and protein synthesis. A transcriptome analysis revealed up-regulation of the electron transport chain, specifically the alternative oxidative pathway in ATCC 1015, while CBS 513.88 showed significant up regulation of genes associated with biosynthesis of amino acids that are abundant in glucoamylase A, tRNA-synthases and protein transporters.

  17. Comparative genomics of citric-acid-producing Aspergillus niger ATCC 1015 versus enzyme-producing CBS 513.88

    Science.gov (United States)

    Andersen, Mikael R.; Salazar, Margarita P.; Schaap, Peter J.; van de Vondervoort, Peter J.I.; Culley, David; Thykaer, Jette; Frisvad, Jens C.; Nielsen, Kristian F.; Albang, Richard; Albermann, Kaj; Berka, Randy M.; Braus, Gerhard H.; Braus-Stromeyer, Susanna A.; Corrochano, Luis M.; Dai, Ziyu; van Dijck, Piet W.M.; Hofmann, Gerald; Lasure, Linda L.; Magnuson, Jon K.; Menke, Hildegard; Meijer, Martin; Meijer, Susan L.; Nielsen, Jakob B.; Nielsen, Michael L.; van Ooyen, Albert J.J.; Pel, Herman J.; Poulsen, Lars; Samson, Rob A.; Stam, Hein; Tsang, Adrian; van den Brink, Johannes M.; Atkins, Alex; Aerts, Andrea; Shapiro, Harris; Pangilinan, Jasmyn; Salamov, Asaf; Lou, Yigong; Lindquist, Erika; Lucas, Susan; Grimwood, Jane; Grigoriev, Igor V.; Kubicek, Christian P.; Martinez, Diego; van Peij, Noël N.M.E.; Roubos, Johannes A.; Nielsen, Jens; Baker, Scott E.

    2011-01-01

    The filamentous fungus Aspergillus niger exhibits great diversity in its phenotype. It is found globally, both as marine and terrestrial strains, produces both organic acids and hydrolytic enzymes in high amounts, and some isolates exhibit pathogenicity. Although the genome of an industrial enzyme-producing A. niger strain (CBS 513.88) has already been sequenced, the versatility and diversity of this species compel additional exploration. We therefore undertook whole-genome sequencing of the acidogenic A. niger wild-type strain (ATCC 1015) and produced a genome sequence of very high quality. Only 15 gaps are present in the sequence, and half the telomeric regions have been elucidated. Moreover, sequence information from ATCC 1015 was used to improve the genome sequence of CBS 513.88. Chromosome-level comparisons uncovered several genome rearrangements, deletions, a clear case of strain-specific horizontal gene transfer, and identification of 0.8 Mb of novel sequence. Single nucleotide polymorphisms per kilobase (SNPs/kb) between the two strains were found to be exceptionally high (average: 7.8, maximum: 160 SNPs/kb). High variation within the species was confirmed with exo-metabolite profiling and phylogenetics. Detailed lists of alleles were generated, and genotypic differences were observed to accumulate in metabolic pathways essential to acid production and protein synthesis. A transcriptome analysis supported up-regulation of genes associated with biosynthesis of amino acids that are abundant in glucoamylase A, tRNA-synthases, and protein transporters in the protein producing CBS 513.88 strain. Our results and data sets from this integrative systems biology analysis resulted in a snapshot of fungal evolution and will support further optimization of cell factories based on filamentous fungi. PMID:21543515

  18. Comparative genomics of citric-acid producing Aspergillus niger ATCC 1015 versus enzyme-producing CBS 513.88

    Energy Technology Data Exchange (ETDEWEB)

    Grigoriev, Igor V.; Baker, Scott E.; Andersen, Mikael R.; Salazar, Margarita P.; Schaap, Peter J.; Vondervoot, Peter J.I. van de; Culley, David; Thykaer, Jette; Frisvad, Jens C.; Nielsen, Kristen F.; Albang, Richard; Albermann, Kaj; Berka, Randy M.; Braus, Gerhard H.; Braus-Stromeyer, Susanna A.; Corrochano, Luis M.; Dai, Ziyu; Dijck, Piet W.M. van; Hofmann, Gerald; Lasure, Linda L.; Magnusson, Jon K.; Meijer, Susan L.; Nielsen, Jakob B.; Nielsen, Michael L.; Ooyen, Albert J.J. van; Panther, Kathyrn S.; Pel, Herman J.; Poulsen, Lars; Samson, Rob A.; Stam, Hen; Tsang, Adrian; Brink, Johannes M. van den; Atkins, Alex; Aerts, Andrea; Shapiro, Harris; Pangilinan, Jasmyn; Salamov, Asaf; Lou, Yigong; Lindquist, Erika; Lucas, Susan; Grimwood, Jane; Kubicek, Christian P.; Martinez, Diego; Peij, Noel N.M.E. van; Roubos, Johannes A.; Nielsen, Jens

    2011-04-28

    The filamentous fungus Aspergillus niger exhibits great diversity in its phenotype. It is found globally, both as marine and terrestrial strains, produces both organic acids and hydrolytic enzymes in high amounts, and some isolates exhibit pathogenicity. Although the genome of an industrial enzyme-producing A. niger strain (CBS 513.88) has already been sequenced, the versatility and diversity of this species compels additional exploration. We therefore undertook whole genome sequencing of the acidogenic A. niger wild type strain (ATCC 1015), and produced a genome sequence of very high quality. Only 15 gaps are present in the sequence and half the telomeric regions have been elucidated. Moreover, sequence information from ATCC 1015 was utilized to improve the genome sequence of CBS 513.88. Chromosome-level comparisons uncovered several genome rearrangements, deletions, a clear case of strain-specific horizontal gene transfer, and identification of 0.8 megabase of novel sequence. Single nucleotide polymorphisms per kilobase (SNPs/kb) between the two strains were found to be exceptionally high (average: 7.8, maximum: 160 SNPs/kb). High variation within the species was confirmed with exo-metabolite profiling and phylogenetics. Detailed lists of alleles were generated, and genotypic differences were observed to accumulate in metabolic pathways essential to acid production and protein synthesis. A transcriptome analysis revealed up-regulation of the electron transport chain, specifically the alternative oxidative pathway in ATCC 1015, while CBS 513.88 showed significant up-regulation of genes relevant to glucoamylase A production, such as tRNA-synthases and protein transporters. Our results and datasets from this integrative systems biology analysis resulted in a snapshot of fungal evolution and will support further optimization of cell factories based on filamentous fungi.[Supplemental materials (10 figures, three text documents and 16 tables) have been made available

  19. Isolation and characterization of a T7-like lytic phage for Pseudomonas fluorescens

    Directory of Open Access Journals (Sweden)

    Neubauer Peter

    2008-10-01

    Full Text Available Abstract Background Despite the proven relevance of Pseudomonas fluorescens as a spoilage microorganism in milk, fresh meats and refrigerated food products and the recognized potential of bacteriophages as sanitation agents, so far no phages specific for P. fluorescens isolates from dairy industry have been closely characterized in view of their lytic efficiency. Here we describe the isolation and characterization of a lytic phage capable to infect a variety of P. fluorescens strains isolated from Portuguese and United States dairy industries. Results Several phages were isolated which showed a different host spectrum and efficiency of lysis. One of the phages, phage ϕIBB-PF7A, was studied in detail due to its efficient lysis of a wide spectrum of P. fluorescens strains and ribotypes. Phage ϕIBB-PF7A with a head diameter of about 63 nm and a tail size of about 13 × 8 nm belongs morphologically to the Podoviridae family and resembles a typical T7-like phage, as analyzed by transmission electron microscopy (TEM. The phage growth cycle with a detected latent period of 15 min, an eclipse period of 10 min, a burst size of 153 plaque forming units per infected cell, its genome size of approximately 42 kbp, and the size and N-terminal sequence of one of the protein bands, which gave similarity to the major capsid protein 10A, are consistent with this classification. Conclusion The isolated T7-like phage, phage ϕIBB-PF7A, is fast and efficient in lysing different P. fluorescens strains and may be a good candidate to be used as a sanitation agent to control the prevalence of spoilage causing P. fluorescens strains in dairy and food related environments.

  20. Trypanosome lytic factor, an antimicrobial high-density lipoprotein, ameliorates Leishmania infection.

    Directory of Open Access Journals (Sweden)

    Marie Samanovic

    2009-01-01

    Full Text Available Innate immunity is the first line of defense against invading microorganisms. Trypanosome Lytic Factor (TLF is a minor sub-fraction of human high-density lipoprotein that provides innate immunity by completely protecting humans from infection by most species of African trypanosomes, which belong to the Kinetoplastida order. Herein, we demonstrate the broader protective effects of human TLF, which inhibits intracellular infection by Leishmania, a kinetoplastid that replicates in phagolysosomes of macrophages. We show that TLF accumulates within the parasitophorous vacuole of macrophages in vitro and reduces the number of Leishmania metacyclic promastigotes, but not amastigotes. We do not detect any activation of the macrophages by TLF in the presence or absence of Leishmania, and therefore propose that TLF directly damages the parasite in the acidic parasitophorous vacuole. To investigate the physiological relevance of this observation, we have reconstituted lytic activity in vivo by generating mice that express the two main protein components of TLFs: human apolipoprotein L-I and haptoglobin-related protein. Both proteins are expressed in mice at levels equivalent to those found in humans and circulate within high-density lipoproteins. We find that TLF mice can ameliorate an infection with Leishmania by significantly reducing the pathogen burden. In contrast, TLF mice were not protected against infection by the kinetoplastid Trypanosoma cruzi, which infects many cell types and transiently passes through a phagolysosome. We conclude that TLF not only determines species specificity for African trypanosomes, but can also ameliorate an infection with Leishmania, while having no effect on T. cruzi. We propose that TLFs are a component of the innate immune system that can limit infections by their ability to selectively damage pathogens in phagolysosomes within the reticuloendothelial system.

  1. Cortex Peptidoglycan Lytic Activity in Germinating Bacillus anthracis Spores▿

    OpenAIRE

    2008-01-01

    Bacterial endospore dormancy and resistance properties depend on the relative dehydration of the spore core, which is maintained by the spore membrane and its surrounding cortex peptidoglycan wall. During spore germination, the cortex peptidoglycan is rapidly hydrolyzed by lytic enzymes packaged into the dormant spore. The peptidoglycan structures in both dormant and germinating Bacillus anthracis Sterne spores were analyzed. The B. anthracis dormant spore peptidoglycan was similar to that fo...

  2. Microorganisms resistant to free-living amoebae.

    Science.gov (United States)

    Greub, Gilbert; Raoult, Didier

    2004-04-01

    Free-living amoebae feed on bacteria, fungi, and algae. However, some microorganisms have evolved to become resistant to these protists. These amoeba-resistant microorganisms include established pathogens, such as Cryptococcus neoformans, Legionella spp., Chlamydophila pneumoniae, Mycobacterium avium, Listeria monocytogenes, Pseudomonas aeruginosa, and Francisella tularensis, and emerging pathogens, such as Bosea spp., Simkania negevensis, Parachlamydia acanthamoebae, and Legionella-like amoebal pathogens. Some of these amoeba-resistant bacteria (ARB) are lytic for their amoebal host, while others are considered endosymbionts, since a stable host-parasite ratio is maintained. Free-living amoebae represent an important reservoir of ARB and may, while encysted, protect the internalized bacteria from chlorine and other biocides. Free-living amoebae may act as a Trojan horse, bringing hidden ARB within the human "Troy," and may produce vesicles filled with ARB, increasing their transmission potential. Free-living amoebae may also play a role in the selection of virulence traits and in adaptation to survival in macrophages. Thus, intra-amoebal growth was found to enhance virulence, and similar mechanisms seem to be implicated in the survival of ARB in response to both amoebae and macrophages. Moreover, free-living amoebae represent a useful tool for the culture of some intracellular bacteria and new bacterial species that might be potential emerging pathogens.

  3. The future of starch bioengineering:GM microorganisms or GM plants?

    OpenAIRE

    Kim Henrik eHebelstrup; Domenico eSagnelli; Andreas eBlennow

    2015-01-01

    Plant starches regularly require extensive modification to permit subsequent applications. Such processing is usually done by the use of chemical and/or physical treatments. The use of recombinant enzymes produced by large-scale fermentation of GM microorganisms is increasingly used in starch processing and modification, sometimes as an alternative to chemical or physical treatments. However, as a means to impart the modifications as early as possible in the starch production chain, similar r...

  4. Biosurfactants from marine microorganisms

    OpenAIRE

    Suppasil Maneerat

    2005-01-01

    Biosurfactants are the surface-active molecules synthesized by microorganisms. With the advantage of environmental compatibility, the demand for biosurfactants has been steadily increasing and may eventually replace their chemically synthesized counterparts. Marine biosurfactants produced by some marine microorganisms have been paid more attention, particularly for the bioremediation of the sea polluted by crude oil. This review describes screening of biosurfactant-producing microorganisms, t...

  5. Application of an Impedimetric Technique for the Detection of Lytic Infection of Salmonella spp. by Specific Phages

    Directory of Open Access Journals (Sweden)

    Lara R. P. Amorim

    2009-01-01

    Full Text Available This study was performed to evaluate the adaption of the impedimetric method to detect the lytic infection by Salmonella-specific bacteriophages and to provide a higher selectivity to this rapid method in detecting Salmonella spp. by using specific agents. Three bacteriophages and twelve strains of Salmonella spp. were tested. Each of the twelve strains was used separately to inoculate TSB together with each one of the phages. The inoculum concentration was between 106 and 107 cfu/mL, at a cell: phage ratio of 1 : 100. From the sample analysis, based on conductance (G measurements (37°C, the infection could be detected, by observation of both detection-time delay and distinct curve trends. The main conclusions were that kinetic detection by impedance microbiology with phage typing constitutes a method of determining whether a test microorganism is sensitive to the bacteriophage and a method to evaluate whether a lytic bacteriophage is present in a sample, by affecting bacterial growth rate/metabolic change.

  6. A green-light inducible lytic system for cyanobacterial cells.

    Science.gov (United States)

    Miyake, Kotone; Abe, Koichi; Ferri, Stefano; Nakajima, Mitsuharu; Nakamura, Mayumi; Yoshida, Wataru; Kojima, Katsuhiro; Ikebukuro, Kazunori; Sode, Koji

    2014-01-01

    Cyanobacteria are an attractive candidate for the production of biofuel because of their ability to capture carbon dioxide by photosynthesis and grow on non-arable land. However, because huge quantities of water are required for cultivation, strict water management is one of the greatest issues in algae- and cyanobacteria-based biofuel production. In this study, we aim to construct a lytic cyanobacterium that can be regulated by a physical signal (green-light illumination) for future use in the recovery of biofuel related compounds. We introduced T4 bacteriophage-derived lysis genes encoding holin and endolysin under the control of the green-light regulated cpcG2 promoter in Synechocystis sp. PCC 6803. When cells harboring the lysis genes were illuminated with both red and green light, we observed a considerable decrease in growth rate, a significant increase in cellular phycocyanin released in the medium, and a considerable fraction of dead cells. These effects were not observed when these cells were illuminated with only red light, or when cells not containing the lysis genes were grown under either red light or red and green light. These results indicate that our constructed green-light inducible lytic system was clearly induced by green-light illumination, resulting in lytic cells that released intracellular phycocyanin into the culture supernatant. This property suggests a future possibility to construct photosynthetic genetically modified organisms that are unable to survive under sunlight exposure. Expression of the self-lysis system with green-light illumination was also found to greatly increase the fragility of the cell membrane, as determined by subjecting the induced cells to detergent, osmotic-shock, and freeze-thaw treatments. A green-light inducible lytic system was constructed in Synechocystis sp. PCC 6803. The engineered lytic cyanobacterial cells should be beneficial for the recovery of biofuels and related compounds from cells with minimal effort

  7. The future of starch bioengineering: GM microorganisms or GM plants?

    DEFF Research Database (Denmark)

    Hebelstrup, Kim; Sagnelli, Domenico; Blennow, Andreas

    2015-01-01

    Plant starches regularly require extensive modification to permit subsequent applications. Such processing is usually done by the use of chemical and/or physical treatments. The use of recombinant enzymes produced by large-scale fermentation of GM microorganisms is increasingly used in starch...... processing and modification, sometimes as an alternative to chemical or physical treatments. However, as a means to impart the modifications as early as possible in the starch production chain, similar recombinant enzymes may also be expressed in planta in the developing starch storage organ such as in roots......, tubers and cereal grains to provide a GM crop as an alternative to the use of enzymes from GM microorganisms. We here discuss these techniques in relation to important structural features and modifications of starches such as: starch phosphorylation, starch hydrolysis, chain transfer/branching and novel...

  8. Microorganisms (Microbes), Role of

    DEFF Research Database (Denmark)

    Fenchel, Tom

    2013-01-01

    Microorganisms (microbes) are those life forms too small to be seen by the naked eye; that is, those that require a microscope or other form of magnification in order to be observed. The term microorganism is thus a functional description rather than a taxonomic one, and the grouping includes...

  9. Microorganisms (Microbes), Role of

    DEFF Research Database (Denmark)

    Fenchel, Tom

    2013-01-01

    Microorganisms (microbes) are those life forms too small to be seen by the naked eye; that is, those that require a microscope or other form of magnification in order to be observed. The term microorganism is thus a functional description rather than a taxonomic one, and the grouping includes a w...

  10. Use of lytic bacteriophages to reduce Salmonella Enteritidis in experimentally contaminated chicken cuts

    Directory of Open Access Journals (Sweden)

    L Fiorentin

    2005-12-01

    Full Text Available Reducing Salmonella contamination in poultry is of major importance to prevent the introduction of this microorganism into the food chain. Salmonellae may spread during storage time (shelf life whenever pre-harvest control fails or post-harvest contamination occurs. Therefore, preventive measures should also be used in the post-harvest level of poultry production in order to control salmonellae. Chicken skin samples were experimentally contaminated by immersing whole legs (thighs and drumsticks in a suspension containing 10(6 colony forming units per milliliter (CFU/mL of Salmonella Enteritidis phage type 4 (SE PT4 at the slaughter day. One day later, samples from one group were immersed in a suspension pool containing 10(9 CFU/mL of each of three wild salmonella-lytic bacteriophages previously isolated from feces of free-range chickens. Salmonella counting was performed at three-day intervals in the chicken legs stored at 5°C and showed a significant reduction (P<0.05 of SE PT4 in bacteriophage-treated cuts on days 3, 6 and 9 post-treatment. These findings suggest that the use of bacteriophages may reduce SE PT4 in chicken skin. Further studies are encouraged and might demonstrate the potential of this approach as an efficient and safe technique to be routinelly used for Salmonella control in chicken products.

  11. Structural characterization of Lytic Polysaccharide MonoOxygenases

    DEFF Research Database (Denmark)

    Frandsen, Kristian Erik Høpfner

    Lytic polysaccharide monooxygenases (LPMOs) are a new class of copper-containingmetalloenzymes that have been found to oxidatively degrade polysaccharides (and recently alsooligosaccharides). They dependent on redox partners to provide them with electrons and they utilizemolecular oxygen to cleave......) and their interaction with substratehave been structurally characterized. A number of structures of LsAA9A have been obtained in complexwith a range of cellulosic- and hemicellulosic substrates and with the active site Cu in different redox state.Two of the LsAA9A structures with the active site Cu in essentially a Cu...

  12. Biosurfactants from marine microorganisms

    Directory of Open Access Journals (Sweden)

    Suppasil Maneerat

    2005-11-01

    Full Text Available Biosurfactants are the surface-active molecules synthesized by microorganisms. With the advantage of environmental compatibility, the demand for biosurfactants has been steadily increasing and may eventually replace their chemically synthesized counterparts. Marine biosurfactants produced by some marine microorganisms have been paid more attention, particularly for the bioremediation of the sea polluted by crude oil. This review describes screening of biosurfactant-producing microorganisms, the determination of biosurfactant activity as well as the recovery of marine surfactant. The uses of marine biosurfactants for bioremediation are also discussed.

  13. Microorganisms involved in MIC

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, K. [Danish Technological Institute (Denmark)

    2011-07-01

    Microbiologically influenced corrosion (MIC) is a widespread problem that is difficult to detect and assess because of its complex mechanism. This paper presents the involvement of microorganisms in MIC. Some of the mechanisms that cause MIC include hydrogen consumption, production of acids, anode-cathode formation and electron shuttling. A classic bio-corrosive microorganism in the oil and gas industry is sulphate-reducing prokaryotes (SRP). Methanogens also increase corrosion rates in metals. Some of the phylogenetic orders detected while studying SRP and methanogens are archaeoglobales, clostridiales, methanosarcinales and methanothermococcus. There were some implications, such as growth of SRP not being correlated with growth of methanogens; methanogens were included in MIC risk assessment. A few examples are used to display how microorganisms are involved in topside corrosion and microbial community in producing wells. From the study, it can be concluded that, MIC risk assessment includes system data and empirical knowledge of the distribution and number of microorganisms in the system.

  14. Micro-Organ Device

    Science.gov (United States)

    Gonda, Steve R. (Inventor); Chang, Robert C. (Inventor); Starly, Binil (Inventor); Culbertson, Christopher (Inventor); Holtorf, Heidi L. (Inventor); Sun, Wei (Inventor); Leslie, Julia (Inventor)

    2013-01-01

    A method for fabricating a micro-organ device comprises providing a microscale support having one or more microfluidic channels and one or more micro-chambers for housing a micro-organ and printing a micro-organ on the microscale support using a cell suspension in a syringe controlled by a computer-aided tissue engineering system, wherein the cell suspension comprises cells suspended in a solution containing a material that functions as a three-dimensional scaffold. The printing is performed with the computer-aided tissue engineering system according to a particular pattern. The micro-organ device comprises at least one micro-chamber each housing a micro-organ; and at least one microfluidic channel connected to the micro-chamber, wherein the micro-organ comprises cells arranged in a configuration that includes microscale spacing between portions of the cells to facilitate diffusion exchange between the cells and a medium supplied from the at least one microfluidic channel.

  15. Rumen microorganisms and fermentation

    Directory of Open Access Journals (Sweden)

    AR Castillo-González

    2014-01-01

    Full Text Available The rumen consists of a complex ecosystem where nutrients consumed by ruminants are digested by fermentation process, which is executed by diverse microorganisms such as bacteria, protozoa, and fungi. A symbiotic relationship is found among different groups of microorganisms due to the diverse nature of these microbial species and their adaptability and interactions also coexist. The ruminant provides the necessary environment for the establishment of such microorganisms, while the microorganisms obtain energy from the host animal from microbial fermentation end products. Within the ruminal ecosystem, the microorganisms coexist in a reduced environment and pH remains close to neutral. Rumen microorganisms are involved in the fermentation of substrates contained in thedietof the animals (carbohydrates, proteins and lipids. However, the fermentation process is not 100% effective because there are energy losses mainly in the form of methane gas (CH4, which is a problem for the environment since it is a greenhouse gas. In order to improve the efficiency of ruminant production systems, nutritional strategies that aim to manipulate ruminal fermentation using additives in the diet such as monensin, tallow, buffers, nitrogen compounds, probiotics, and others have been used. These additives allow changing the ruminal fermentation process in ways that produce better growth efficiency while decreasing energy loss. The purpose of this review is to contribute to a better understanding of the fermentation processes taking place in the rumen, providing information that can be applied in the development of new nutritional strategies for the improvement of the digestion process to achieve maximum production.

  16. Characterization of newly isolated lytic bacteriophages active against Acinetobacter baumannii.

    Science.gov (United States)

    Merabishvili, Maia; Vandenheuvel, Dieter; Kropinski, Andrew M; Mast, Jan; De Vos, Daniel; Verbeken, Gilbert; Noben, Jean-Paul; Lavigne, Rob; Vaneechoutte, Mario; Pirnay, Jean-Paul

    2014-01-01

    Based on genotyping and host range, two newly isolated lytic bacteriophages, myovirus vB_AbaM_Acibel004 and podovirus vB_AbaP_Acibel007, active against Acinetobacter baumannii clinical strains, were selected from a new phage library for further characterization. The complete genomes of the two phages were analyzed. Both phages are characterized by broad host range and essential features of potential therapeutic phages, such as short latent period (27 and 21 min, respectively), high burst size (125 and 145, respectively), stability of activity in liquid culture and low frequency of occurrence of phage-resistant mutant bacterial cells. Genomic analysis showed that while Acibel004 represents a novel bacteriophage with resemblance to some unclassified Pseudomonas aeruginosa phages, Acibel007 belongs to the well-characterized genus of the Phikmvlikevirus. The newly isolated phages can serve as potential candidates for phage cocktails to control A. baumannii infections.

  17. Characterization of newly isolated lytic bacteriophages active against Acinetobacter baumannii.

    Directory of Open Access Journals (Sweden)

    Maia Merabishvili

    Full Text Available Based on genotyping and host range, two newly isolated lytic bacteriophages, myovirus vB_AbaM_Acibel004 and podovirus vB_AbaP_Acibel007, active against Acinetobacter baumannii clinical strains, were selected from a new phage library for further characterization. The complete genomes of the two phages were analyzed. Both phages are characterized by broad host range and essential features of potential therapeutic phages, such as short latent period (27 and 21 min, respectively, high burst size (125 and 145, respectively, stability of activity in liquid culture and low frequency of occurrence of phage-resistant mutant bacterial cells. Genomic analysis showed that while Acibel004 represents a novel bacteriophage with resemblance to some unclassified Pseudomonas aeruginosa phages, Acibel007 belongs to the well-characterized genus of the Phikmvlikevirus. The newly isolated phages can serve as potential candidates for phage cocktails to control A. baumannii infections.

  18. Lytic polysaccharide monooxygenases disrupt the cellulose fibers structure

    Science.gov (United States)

    Villares, Ana; Moreau, Céline; Bennati-Granier, Chloé; Garajova, Sona; Foucat, Loïc; Falourd, Xavier; Saake, Bodo; Berrin, Jean-Guy; Cathala, Bernard

    2017-01-01

    Lytic polysaccharide monooxygenases (LPMOs) are a class of powerful oxidative enzymes that breakdown recalcitrant polysaccharides such as cellulose. Here we investigate the action of LPMOs on cellulose fibers. After enzymatic treatment and dispersion, LPMO-treated fibers show intense fibrillation. Cellulose structure modifications visualized at different scales indicate that LPMO creates nicking points that trigger the disintegration of the cellulose fibrillar structure with rupture of chains and release of elementary nanofibrils. Investigation of LPMO action using solid-state NMR provides direct evidence of modification of accessible and inaccessible surfaces surrounding the crystalline core of the fibrils. The chains breakage likely induces modifications of the cellulose network and weakens fibers cohesion promoting their disruption. Besides the formation of new initiation sites for conventional cellulases, this work provides the first evidence of the direct oxidative action of LPMOs with the mechanical weakening of the cellulose ultrastructure. LPMOs can be viewed as promising biocatalysts for enzymatic modification or degradation of cellulose fibers. PMID:28071716

  19. Increased Lytic Efficiency of Bovine Macrophages Trained with Killed Mycobacteria

    Science.gov (United States)

    Juste, Ramon A.; Alonso-Hearn, Marta; Garrido, Joseba M.; Abendaño, Naiara; Sevilla, Iker A.; Gortazar, Christian; de la Fuente, José; Dominguez, Lucas

    2016-01-01

    Innate immunity is evolutionarily conserved in multicellular organisms and was considered to lack memory until very recently. One of its more characteristic mechanisms is phagocytosis, the ability of cells to engulf, process and eventually destroy any injuring agent. We report the results of an ex vivo experiment in bovine macrophages in which improved clearance of Mycobacterium bovis (M. bovis) was induced by pre-exposure to a heat killed M. bovis preparation. The effects were independent of humoral and cellular adaptive immune responses and lasted up to six months. Specifically, our results demonstrate the existence of a training effect in the lytic phase of phagocytosis that can be activated by killed mycobacteria, thus suggesting a new mechanism of vaccine protection. These findings are compatible with the recently proposed concept of trained immunity, which was developed to explain the observation that innate immune responses provide unspecific protection against pathogens including other than those that originally triggered the immune response. PMID:27820836

  20. Structural characterization of Lytic Polysaccharide MonoOxygenases

    DEFF Research Database (Denmark)

    Frandsen, Kristian Erik Høpfner

    Lytic polysaccharide monooxygenases (LPMOs) are a new class of copper-containingmetalloenzymes that have been found to oxidatively degrade polysaccharides (and recently alsooligosaccharides). They dependent on redox partners to provide them with electrons and they utilizemolecular oxygen to cleave......) and their interaction with substratehave been structurally characterized. A number of structures of LsAA9A have been obtained in complexwith a range of cellulosic- and hemicellulosic substrates and with the active site Cu in different redox state.Two of the LsAA9A structures with the active site Cu in essentially a Cu......(II) state show differences in thenature of the Cu-ligand with and without cellulosic substrate bound and provide structural insight into themechanistic action of LPMOs. Interestingly, for an LsAA9A complex structure with a hemicellulosicsubstrate (xylooligosaccharide) a corresponding difference...

  1. Elastohydrodynamics of flagellated microorganisms

    Science.gov (United States)

    Li, Gaojin; Ardekani, Arezoo

    2016-11-01

    The swimming motion of many microorganisms and cells are achieved by the waving deformation of their cilia and flagella. The typical structure of flagella and cilia contains nine doublets of parallel microtubules in a cylindrical arrangement surrounding one pair of microtubules in the center. The dynein molecular motors internally drive the sliding motion between the neighboring microtubules and cause the bending motion of the flagella and cilia and drive the microorganism swimming motion. In this work, we develop a numerical model for a microorganism swimming by an internally self-driven filament. Our numerical method captures the interaction between the elasticity of the flagellum and the surround fluid. The no-slip boundary conditions are satisfied by an iterative distributed Lagrangian multiplier method. We also investigate the effects of the non-Newtonian fluid rheology on the motion of an elastic flagellum near a wall.

  2. 5-hydroxymethylation of the EBV genome regulates the latent to lytic switch.

    Science.gov (United States)

    Wille, Coral K; Nawandar, Dhananjay M; Henning, Amanda N; Ma, Shidong; Oetting, Kayla M; Lee, Dennis; Lambert, Paul; Johannsen, Eric C; Kenney, Shannon C

    2015-12-29

    Latent Epstein-Barr virus (EBV) infection and cellular hypermethylation are hallmarks of undifferentiated nasopharyngeal carcinoma (NPC). However, EBV infection of normal oral epithelial cells is confined to differentiated cells and is lytic. Here we demonstrate that the EBV genome can become 5-hydroxymethylated and that this DNA modification affects EBV lytic reactivation. We show that global 5-hydroxymethylcytosine (5hmC)-modified DNA accumulates during normal epithelial-cell differentiation, whereas EBV+ NPCs have little if any 5hmC-modified DNA. Furthermore, we find that increasing cellular ten-eleven translocation (TET) activity [which converts methylated cytosine (5mC) to 5hmC] decreases methylation, and increases 5hmC modification, of lytic EBV promoters in EBV-infected cell lines containing highly methylated viral genomes. Conversely, inhibition of endogenous TET activity increases lytic EBV promoter methylation in an EBV-infected telomerase-immortalized normal oral keratinocyte (NOKs) cell line where lytic viral promoters are largely unmethylated. We demonstrate that these cytosine modifications differentially affect the ability of the two EBV immediate-early proteins, BZLF1 (Z) and BRLF1 (R), to induce the lytic form of viral infection. Although methylation of lytic EBV promoters increases Z-mediated and inhibits R-mediated lytic reactivation, 5hmC modification of lytic EBV promoters has the opposite effect. We also identify a specific CpG-containing Z-binding site on the BRLF1 promoter that must be methylated for Z-mediated viral reactivation and show that TET-mediated 5hmC modification of this site in NOKs prevents Z-mediated viral reactivation. Decreased 5-hydroxymethylation of cellular and viral genes may contribute to NPC formation.

  3. Modelling microorganisms in food

    NARCIS (Netherlands)

    Brul, S.; Gerwen, van S.; Zwietering, M.H.

    2007-01-01

    Predicting the growth and behaviour of microorganisms in food has long been an aim in food microbiology research. In recent years, microbial models have evolved to become more exact and the discipline of quantitative microbial ecology has gained increasing importance for food safety management, part

  4. Complete Genome Sequences of Lytic Bacteriophages of Xanthomonas arboricola pv. juglandis.

    Science.gov (United States)

    Retamales, Julio; Vasquez, Ignacio; Santos, Leonardo; Segovia, Cristopher; Ayala, Manuel; Alvarado, Romina; Nuñez, Pablo; Santander, Javier

    2016-06-02

    Three bacteriophages, f20-Xaj, f29-Xaj, and f30-Xaj, with lytic activity against Xanthomonas arboricola pv. juglandis were isolated from walnut trees (VIII Bío Bío Region, Chile). These lytic bacteriophages have double-stranded DNA (dsDNA) genomes of 43,851 bp, 41,865 bp, and 44,262 bp, respectively. These are the first described bacteriophages with lytic activity against X. arboricola pv. juglandis that can be utilized as biocontrol agents.

  5. Properties of Brucella-phages lytic for non-smooth Brucella strains.

    Science.gov (United States)

    Corbel, M J

    1984-01-01

    A series of host-range mutants has been selected for brucella-phage R. Two of these mutants designated R/O and R/C have been used for typing purposes. Phage R/O is lytic for non-smooth strains of Brucella abortus and for B. ovis. It is genetically unstable however and produces mutants lytic for smooth B. obortus and B. suis. Phage R/C is lytic for non-smooth B. abortus and for B. ovis and B. canis. It is much more stable than phages R or R/O and shows little or no lytic activity on smooth Brucella strains. It has been effective in differentiating B. canis from B. suis in tests on a limited number of strains. In their properties, all of the brucella-phages of the R series resemble their parent phage.

  6. Inactivation of Microorganisms

    Science.gov (United States)

    Alzamora, Stella Maris; Guerrero, Sandra N.; Schenk, Marcela; Raffellini, Silvia; López-Malo, Aurelio

    Minimal processing techniques for food preservation allow better retention of product flavor, texture, color, and nutrient content than comparable conventional treatments. A wide range of novel alternative physical factors have been intensely investigated in the last two decades. These physical factors can cause inactivation of microorganisms at ambient or sublethal temperatures (e.g., high hydrostatic pressure, pulsed electric fields, ultrasound, pulsed light, and ultraviolet light). These technologies have been reported to reduce microorganism population in foods while avoiding the deleterious effects of severe heating on quality. Among technologies, high-energy ultrasound (i.e., intensities higher than 1 W/cm2, frequencies between 18 and 100 kHz) has attracted considerable interest for food preservation applications (Mason et al., 1996; Povey and Mason, 1998).

  7. Informative communication of microorganisms

    Directory of Open Access Journals (Sweden)

    G. N. Kremenchutskу

    2010-06-01

    Full Text Available Macroorganism in combination with microbiota is considered as a “superorganism”. Microorganisms, belonging to the microbiota, are in dynamic equilibrium with a macroorganism. This balance is achieved through a molecular “language” of communication between prokaryotic and eukaryotic cells. Molecular communication between cells leads to positive and negative results. A large number of metabolites of microorganisms that carry the information load: autoinducers is revealed. Autoinducer affect on the immune systems, and variety of metabolic processes. This affects on practically all organs and systems of maсroorganism. Studied metabolites of aerococci affect on the immune system, regenerative cycles and other processes of macroorganism. The problem of informative communication between prokaryotes and eukaryotes provides new insights about vital functions of “superorganisms”.

  8. Differentiation-Dependent KLF4 Expression Promotes Lytic Epstein-Barr Virus Infection in Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Dhananjay M Nawandar

    2015-10-01

    Full Text Available Epstein-Barr virus (EBV is a human herpesvirus associated with B-cell and epithelial cell malignancies. EBV lytically infects normal differentiated oral epithelial cells, where it causes a tongue lesion known as oral hairy leukoplakia (OHL in immunosuppressed patients. However, the cellular mechanism(s that enable EBV to establish exclusively lytic infection in normal differentiated oral epithelial cells are not currently understood. Here we show that a cellular transcription factor known to promote epithelial cell differentiation, KLF4, induces differentiation-dependent lytic EBV infection by binding to and activating the two EBV immediate-early gene (BZLF1 and BRLF1 promoters. We demonstrate that latently EBV-infected, telomerase-immortalized normal oral keratinocyte (NOKs cells undergo lytic viral reactivation confined to the more differentiated cell layers in organotypic raft culture. Furthermore, we show that endogenous KLF4 expression is required for efficient lytic viral reactivation in response to phorbol ester and sodium butyrate treatment in several different EBV-infected epithelial cell lines, and that the combination of KLF4 and another differentiation-dependent cellular transcription factor, BLIMP1, is highly synergistic for inducing lytic EBV infection. We confirm that both KLF4 and BLIMP1 are expressed in differentiated, but not undifferentiated, epithelial cells in normal tongue tissue, and show that KLF4 and BLIMP1 are both expressed in a patient-derived OHL lesion. In contrast, KLF4 protein is not detectably expressed in B cells, where EBV normally enters latent infection, although KLF4 over-expression is sufficient to induce lytic EBV reactivation in Burkitt lymphoma cells. Thus, KLF4, together with BLIMP1, plays a critical role in mediating lytic EBV reactivation in epithelial cells.

  9. Autochthonous Gut Bacteria in Two Indian Air-breathing Fish, Climbing Perch (Anabas testudineus) and Walking Catfish (Clarias batrachus): Mode of Association, Identification and Enzyme Producing Ability.

    Science.gov (United States)

    Banerjee, Goutam; Dan, Suhas K; Nandi, Ankita; Ghosh, Pinki; Ray, Arun K

    2015-01-01

    Scanning electron microscopy (SEM) was used to define the location of epithelium-associated bacteria in the gastrointestinal (GI) tract of two Indian air-breathing fish, the climbing perch (Anabas testudineus) and walking catfish (Clarias batrachus). The SEM examination revealed substantial numbers of rod shaped bacterial cells associated with the microvillus brush borders of enterocytes in proximal (PI) and distal regions (DI) of the GI tract of both the fish species. Ten (two each from the PI and DI of climbing perch and three each from the PI and DI of walking catfish) isolated bacterial strains were evaluated for extracellular protease, amylase and cellulase production quantitatively. All the bacterial strains exhibited high cellulolytic activity compared to amylolytic and proteolytic activites. Only two strains, CBH6 and CBH7, isolated from the DI of walking catfish exhibited high proteolytic activity. Maximum cellulase activity was exhibited by the strain, CBF2, isolated from the PI of climbing perch. Six most promising enzyme-producing adherent bacterial strains were identified by 16S rDNA gene sequence analysis. The strain ATH1 (isolated from climbing perch) showed high similarity fo Bacillus amyloliquefaciens whereas, the remaining five strains (isolated from walking catfish) were most closely related to Bacillus licheniformis.

  10. Decolourisation Capabilities of Ligninolytic Enzymes Produced by Marasmius cladophyllus UMAS MS8 on Remazol Brilliant Blue R and Other Azo Dyes

    Directory of Open Access Journals (Sweden)

    Ngieng Ngui Sing

    2017-01-01

    Full Text Available Marasmius cladophyllus was examined for its ability to degradatively decolourise the recalcitrant dye Remazol Brilliant Blue R (RBBR and screened for the production of ligninolytic enzymes using specific substrates. Monitoring dye decolourisation by the decrease in absorbance ratio of A592/A500 shows that the decolourisation of RBBR dye was associated with the dye degradation. Marasmius cladophyllus produces laccase and lignin peroxidase in glucose minimal liquid medium containing RBBR. Both enzyme activities were increased, with laccase activity recorded 70 times higher reaching up to 390 U L−1 on day 12. Further in vitro RBBR dye decolourisation using the culture medium shows that laccase activity was correlated with the dye decolourisation. Fresh RBBR dye continuously supplemented into the decolourised culture medium was further decolourised much faster in the subsequent round of the RBBR dye decolourisation. In vitro dye decolourisation using the crude laccase not only decolourised 76% of RBBR dye in just 19 hours but also decolourised 54% of Orange G and 33% of Congo red at the same period of time without the use of any exogenous mediator. This rapid dye decolourisation ability of the enzymes produced by M. cladophyllus thus suggested its possible application in the bioremediation of dye containing wastewater.

  11. Enhancement of Lytic Activity by Leptin Is Independent From Lipid Rafts in Murine Primary Splenocytes.

    Science.gov (United States)

    Collin, Aurore; Noacco, Audrey; Talvas, Jérémie; Caldefie-Chézet, Florence; Vasson, Marie-Paule; Farges, Marie-Chantal

    2017-01-01

    Leptin, a pleiotropic adipokine, is known as a regulator of food intake, but it is also involved in inflammation, immunity, cell proliferation, and survival. Leptin receptor is integrated inside cholesterol-rich microdomains called lipid rafts, which, if disrupted or destroyed, could lead to a perturbation of lytic mechanism. Previous studies also reported that leptin could induce membrane remodeling. In this context, we studied the effect of membrane remodeling in lytic activity modulation induced by leptin. Thus, primary mouse splenocytes were incubated with methyl-β-cyclodextrin (β-MCD), a lipid rafts disrupting agent, cholesterol, a major component of cell membranes, or ursodeoxycholic acid (UDCA), a membrane stabilizer agent for 1 h. These treatments were followed by splenocyte incubation with leptin (absence, 10 and 100 ng/ml). Unlike β-MCD or cholesterol, UDCA was able to block leptin lytic induction. This result suggests that leptin increased the lytic activity of primary spleen cells against syngenic EO771 mammary cancer cells independently from lipid rafts but may involve membrane fluidity. Furthermore, natural killer cells were shown to be involved in the splenocyte lytic activity. To our knowledge it is the first publication in primary culture that provides the link between leptin lytic modulation and membrane remodeling. J. Cell. Physiol. 232: 101-109, 2017. © 2016 Wiley Periodicals, Inc.

  12. Analysis of nanomechanical properties of Borrelia burgdorferi spirochetes under the influence of lytic factors in an in vitro model using atomic force microscopy.

    Science.gov (United States)

    Tokarska-Rodak, Małgorzata; Kozioł-Montewka, Maria; Skrzypiec, Krzysztof; Chmielewski, Tomasz; Mendyk, Ewaryst; Tylewska-Wierzbanowska, Stanisława

    2015-11-12

    Atomic force microscopy (AFM) is an experimental technique which recently has been used in biology, microbiology, and medicine to investigate the topography of surfaces and in the evaluation of mechanical properties of cells. The aim of this study was to evaluate the influence of the complement system and specific anti-Borrelia antibodies in in vitro conditions on the modification of nanomechanical features of B. burgdorferi B31 cells. In order to assess the influence of the complement system and anti-Borrelia antibodies on B. burgdorferi s.s. B31 spirochetes, the bacteria were incubated together with plasma of identified status. The samples were applied on the surface of mica disks. Young's modulus and adhesive forces were analyzed with a NanoScope V, MultiMode 8 AFM microscope (Bruker) by the PeakForce QNM technique in air using NanoScope Analysis 1.40 software (Bruker). The average value of flexibility of spirochetes' surface expressed by Young's modulus was 10185.32 MPa, whereas the adhesion force was 3.68 nN. AFM is a modern tool with a broad spectrum of observational and measurement abilities. Young's modulus and the adhesion force can be treated as parameters in the evaluation of intensity and changes which take place in pathogenic microorganisms under the influence of various lytic factors. The visualization of the changes in association with nanomechanical features provides a realistic portrayal of the lytic abilities of the elements of the innate and adaptive human immune system.

  13. Discovery and industrial applications of lytic polysaccharide mono-oxygenases.

    Science.gov (United States)

    Johansen, Katja S

    2016-02-01

    The recent discovery of copper-dependent lytic polysaccharide mono-oxygenases (LPMOs) has opened up a vast area of research covering several fields of application. The biotech company Novozymes A/S holds patents on the use of these enzymes for the conversion of steam-pre-treated plant residues such as straw to free sugars. These patents predate the correct classification of LPMOs and the striking synergistic effect of fungal LPMOs when combined with canonical cellulases was discovered when fractions of fungal secretomes were evaluated in industrially relevant enzyme performance assays. Today, LPMOs are a central component in the Cellic CTec enzyme products which are used in several large-scale plants for the industrial production of lignocellulosic ethanol. LPMOs are characterized by an N-terminal histidine residue which, together with an internal histidine and a tyrosine residue, co-ordinates a single copper atom in a so-called histidine brace. The mechanism by which oxygen binds to the reduced copper atom has been reported and the general mechanism of copper-oxygen-mediated activation of carbon is being investigated in the light of these discoveries. LPMOs are widespread in both the fungal and the bacterial kingdoms, although the range of action of these enzymes remains to be elucidated. However, based on the high abundance of LPMOs expressed by microbes involved in the decomposition of organic matter, the importance of LPMOs in the natural carbon-cycle is predicted to be significant. In addition, it has been suggested that LPMOs play a role in the pathology of infectious diseases such as cholera and to thus be relevant in the field of medicine. © 2016 Authors; published by Portland Press Limited.

  14. The future of starch bioengineering: GM microorganisms or GM plants?

    Directory of Open Access Journals (Sweden)

    Kim Henrik eHebelstrup

    2015-04-01

    Full Text Available Plant starches regularly require extensive modification to permit subsequent applications. Such processing is usually done by the use of chemical and/or physical treatments. The use of recombinant enzymes produced by large-scale fermentation of GM microorganisms is increasingly used in starch processing and modification, sometimes as an alternative to chemical or physical treatments. However, as a means to impart the modifications as early as possible in the starch production chain, similar recombinant enzymes may also be expressed in planta in the developing starch storage organ such as in roots, tubers and cereal grains to provide a GM crop as an alternative to the use of enzymes from GM microorganisms. We here discuss these techniques in relation to important structural features and modifications of starches such as: starch phosphorylation, starch hydrolysis, chain transfer/branching and novel concepts of hybrid starch-based polysaccharides. In planta starch bioengineering is generally challenged by yield penalties and inefficient production of the desired product. However in some situations, GM crops for starch bioengineering without deleterious effects have been achieved.

  15. Efficacy of lytic Staphylococcus aureus bacteriophage against multidrug-resistant Staphylococcus aureus in mice.

    Science.gov (United States)

    Oduor, Joseph Michael Ochieng'; Onkoba, Nyamongo; Maloba, Fredrick; Arodi, Washingtone Ouma; Nyachieo, Atunga

    2016-11-24

    The use of bacteriophages as an alternative treatment method against multidrug-resistant bacteria has not been explored in Kenya. This study sought to determine the efficacy of environmentally obtained lytic bacteriophage against multidrug-resistant Staphylococcus aureus (MDRSA) bacterium in mice. Staphylococcus aureus bacterium and S. aureus-specific lytic phage were isolated from sewage and wastewater collected within Nairobi County, Kenya. Thirty mice were randomly assigned into three groups: MDRSA infection group (n = 20), phage-infection group (n = 5), and non-infection group (n = 5). The MDRSA infection group was further subdivided into three groups: clindamycin treatment (8 mg/kg; n = 5), lytic phage treatment (108 PFU/mL (n = 5), and a combination treatment of clindamycin and lytic phage (n = 5). Treatments were done at either 24 or 72 hours post-infection (p.i), and data on efficacy, bacterial load, and animal physical health were collected. Treatment with phage was more effective (100%) than with clindamycin (62.25% at 24 hours p.i and 87.5% at 72 hours p.i.) or combination treatment (75% at 24 hours p.i. and 90% at 72 hours p.i.) (p aureus lytic bacteriophage has therapeutic potential against MDRSA bacterium in mice.

  16. TRIM5α Promotes Ubiquitination of Rta from Epstein–Barr Virus to Attenuate Lytic Progression

    Science.gov (United States)

    Huang, Hsiang-Hung; Chen, Chien-Sin; Wang, Wen-Hung; Hsu, Shih-Wei; Tsai, Hsiao-Han; Liu, Shih-Tung; Chang, Li-Kwan

    2017-01-01

    Replication and transcription activator (Rta), a key protein expressed by Epstein–Barr virus (EBV) during the immediate-early stage of the lytic cycle, is responsible for the activation of viral lytic genes. In this study, GST-pulldown and coimmunoprecipitation assays showed that Rta interacts in vitro and in vivo with TRIM5α, a host factor known to be involved in the restriction of retroviral infections. Confocal microscopy results revealed that Rta colocalizes with TRIM5α in the nucleus during lytic progression. The interaction involves 190 amino acids in the N-terminal of Rta and the RING domain in TRIM5α, and it was further found that TRIM5α acts as an E3 ubiquitin ligase to promote Rta ubiquitination. Overexpression of TRIM5α reduced the transactivating capabilities of Rta, while reducing TRIM5α expression enhanced EBV lytic protein expression and DNA replication. Taken together, these results point to a critical role for TRIM5α in attenuating EBV lytic progression through the targeting of Rta for ubiquitination, and suggest that the restrictive capabilities of TRIM5α may go beyond retroviral infections. PMID:28105027

  17. A Herpesviral Lytic Protein Regulates the Structure of Latent Viral Chromatin

    Directory of Open Access Journals (Sweden)

    Priya Raja

    2016-05-01

    Full Text Available Latent infections by viruses usually involve minimizing viral protein expression so that the host immune system cannot recognize the infected cell through the viral peptides presented on its cell surface. Herpes simplex virus (HSV, for example, is thought to express noncoding RNAs such as latency-associated transcripts (LATs and microRNAs (miRNAs as the only abundant viral gene products during latent infection. Here we describe analysis of HSV-1 mutant viruses, providing strong genetic evidence that HSV-infected cell protein 0 (ICP0 is expressed during establishment and/or maintenance of latent infection in murine sensory neurons in vivo. Studies of an ICP0 nonsense mutant virus showed that ICP0 promotes heterochromatin and latent and lytic transcription, arguing that ICP0 is expressed and functional. We propose that ICP0 promotes transcription of LATs during establishment or maintenance of HSV latent infection, much as it promotes lytic gene transcription. This report introduces the new concept that a lytic viral protein can be expressed during latent infection and can serve dual roles to regulate viral chromatin to optimize latent infection in addition to its role in epigenetic regulation during lytic infection. An additional implication of the results is that ICP0 might serve as a target for an antiviral therapeutic acting on lytic and latent infections.

  18. Inhibition of the Epstein-Barr virus lytic cycle by moronic acid.

    Science.gov (United States)

    Chang, Fang-Rong; Hsieh, Yi-Chung; Chang, Yung-Fu; Lee, Kuo-Hsiung; Wu, Yang-Chang; Chang, Li-Kwan

    2010-03-01

    Epstein-Barr virus (EBV) expresses two transcription factors, Rta and Zta, during the immediate-early stage of the lytic cycle to activate the transcription of viral lytic genes. Our immunoblotting and flow cytometry analyses find that moronic acid, found in galls of Rhus chinensis and Brazilian propolis, at 10microM inhibits the expression of Rta, Zta, and an EBV early protein, EA-D, after lytic induction with sodium butyrate. This study also finds that moronic acids inhibits the capacity of Rta to activate a promoter that contains an Rta-response element, indicating that moronic acid interferes with the function of Rta. On the other hand, moronic acid does not appear to influence with the transactivation function of Zta. Therefore, the lack of expression of Zta and EA-D after moronic acid treatment is attributable to the inhibition of the transactivation functions of Rta. Because the expression of Zta, EA-D and many EBV lytic genes depends on Rta, the treatment of P3HR1 cells with moronic acid substantially reduces the numbers of EBV particles produced by the cells after lytic induction. This study suggests that moronic acid is a new structural lead for anti-EBV drug development.

  19. The Lytic SA Phage Demonstrate Bactericidal Activity against Mastitis Causing Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Hamza Ameer

    2016-01-01

    Full Text Available Staphylococcus aureus is the major causative agent of mastitis among dairy animals as it causes intramammary gland infection. Due to antibiotic resistance and contamination of antibiotics in the milk of diseased animals; alternative therapeutic agents are required to cure mastitis. Lytic bacteriophages and their gene products can be potential therapeutic agents against bacteria as they are host specific and less harmful than antibiotics. In this study, Staphylococcus aureus were isolated from milk samples of the infected animals and identified biochemically. SA phage was isolated from sewage water showing lytic activity against Staphylococcus aureus isolates. The highest lytic activity of bacteriophages was observed at 37°C and pH 7, and the most suitable storage condition was at 4°C. SA phage efficiently reduced bacterial growth in the bacterial reduction assay. The characterization and bacterial growth reduction activity of the bacteriophages against Staphylococcus aureus signifies their underlying potential of phage therapy against mastitis.

  20. In vitro cytocidal effect of lytic peptides on several transformed mammalian cell lines.

    Science.gov (United States)

    Jaynes, J M; Julian, G R; Jeffers, G W; White, K L; Enright, F M

    1989-01-01

    Several types of transformed mammalian cells, derived from established cell lines, were found to be lysed in vitro by three novel lytic peptides (SB-37, SB-37*, and Shiva-1). This is in contrast with the behavior of normal cells, where the observed lytic activity of the peptides is greatly reduced. Based on experiments utilizing compounds which disrupt the cytoskeleton (colchicine and cytochalasin-D), it is surmised that alterations in the cytoskeleton of transformed cells increase their sensitivity to the cytolytic activity exerted by the peptides, primarily by causing a loss of osmotic integrity. Thus, a stable and regenerative cytoskeletal system, as that possessed by normal cells, would seem requisite to withstanding the lytic effects of the peptides.

  1. In vitro cytocidal effect of novel lytic peptides on Plasmodium falciparum and Trypanosoma cruzi.

    Science.gov (United States)

    Jaynes, J M; Burton, C A; Barr, S B; Jeffers, G W; Julian, G R; White, K L; Enright, F M; Klei, T R; Laine, R A

    1988-10-01

    Plasmodium falciparum and Trypanosoma cruzi were killed by two novel lytic peptides (SB-37 and Shiva-1) in vitro. Human erythrocytes infected with P. falciparum, and Vero cells infected with T. cruzi, were exposed to these peptides. The result, in both cases, was a significant decrease in the level of parasite infection. Furthermore, the peptides had a marked cytocidal effect on trypomastigote stages of T. cruzi in media, whereas host eukaryotic cells were unaffected by the treatments. In view of the worldwide prevalence of these protozoan diseases and the lack of completely suitable treatments, lytic peptides may provide new and unique chemotherapeutic agents for the treatment of these infections.

  2. Listeria monocytogenes has a functional chitinolytic system and an active lytic polysaccharide monooxygenase

    DEFF Research Database (Denmark)

    Paspaliari, Dafni Katerina; Loose, Jennifer S. M.; Larsen, Marianne Halberg

    2015-01-01

    B) and a multi-modular lytic polysaccharide monooxygenase (LmLPMO10). These enzymes have been related to virulence and their role in chitin metabolism is poorly understood. It is thus of interest to functionally characterize the individual enzymes in order to shed light on their roles in vivo. Our results......Chitinases and chitin-active lytic polysaccharide monooxygenases (LPMOs) are most commonly associated with chitin metabolism, but are also reported as virulence factors in pathogenic bacteria. Listeria monocytogenes, a well-known virulent bacterium, possesses two chitinases (ChiA and Chi...

  3. Undetectable bacterial resistance to phage lytic proteins from the Staphylococcus aureus bacteriophage vB_SauS-phiIPLA88

    Science.gov (United States)

    The increase in antibiotic resistance world-wide revitalized the interest in the use of phage lysins to combat pathogenic bacteria. In this work, we tested for the emergence of resistant Staphylococcus aureus to any of three phage lytic proteins constructs. The investigated cell wall lytic enzymes w...

  4. Regional Variation in Lytic and Lysogenic Viral Infection in the Southern Ocean and Its Contribution to Biogeochemical Cycling

    NARCIS (Netherlands)

    Evans, C.; Brussaard, C.P.D.

    2012-01-01

    Lytic and lysogenic viral infection was investigated throughout the Southern Ocean at sites spanning the sub-Antarctic zone, the Antarctic Circumpolar Current, and an Antarctic continental sea. Higher lytic virus activity was recorded in the more productive sub-Antarctic zone than in the iron-limite

  5. Influence of heavy metals on biosynthesis, activity of lytic enzymes and growthstimulating factor of Streptomyces recifensis var. lyticus P-29

    Directory of Open Access Journals (Sweden)

    Т. P. Kilochok

    2005-02-01

    Full Text Available Influence of heavy metals on growth, biosynthesis, lytic action and growthstimulating activity enzymes complex of Streptomyces recifensis var. lyticus was studied. It was showed that salt of plumbum' has positive influence as on biosynthesis hydrolases (lytic endopeptidases, proteinases, amylases as well increase growthstimulating activity of preparation relatively the yeast

  6. Effectiveness of lytic bacteriophages in reducing E. coli O157:H7 populations introduced through cross-contamination on fresh cut lettuce

    Science.gov (United States)

    Previous research has shown that lytic bacteriophages (phages) can kill E. coli O157:H7 on produce surfaces. The role of lytic bacteriophages in preventing cross contamination of produce has not been evaluated. A cocktail of three lytic phages specific for E. coli O157:H7 (EcoShield) at 10^8 PFU/m...

  7. Complete Genome Sequence of a Lytic Siphoviridae Bacteriophage Infecting Several Serovars of Salmonella enterica

    Science.gov (United States)

    Paradiso, Rubina; Lombardi, Serena; Iodice, Maria Grazia; Riccardi, Marita Georgia; Orsini, Massimiliano; Bolletti Censi, Sergio; Galiero, Giorgio

    2016-01-01

    The bacteriophage 100268_sal2 was isolated from water buffalo feces in southern Italy, exhibiting lytic activity against several subspecies of Salmonella enterica. This bacteriophage belongs to the Siphoviridae family and has a 125,114-bp double-stranded DNA (ds-DNA) genome containing 188 coding sequences (CDSs). PMID:27688334

  8. Oncogenic Herpesvirus Utilizes Stress-Induced Cell Cycle Checkpoints for Efficient Lytic Replication.

    Directory of Open Access Journals (Sweden)

    Giuseppe Balistreri

    2016-02-01

    Full Text Available Kaposi's sarcoma herpesvirus (KSHV causes Kaposi's sarcoma and certain lymphoproliferative malignancies. Latent infection is established in the majority of tumor cells, whereas lytic replication is reactivated in a small fraction of cells, which is important for both virus spread and disease progression. A siRNA screen for novel regulators of KSHV reactivation identified the E3 ubiquitin ligase MDM2 as a negative regulator of viral reactivation. Depletion of MDM2, a repressor of p53, favored efficient activation of the viral lytic transcription program and viral reactivation. During lytic replication cells activated a p53 response, accumulated DNA damage and arrested at G2-phase. Depletion of p21, a p53 target gene, restored cell cycle progression and thereby impaired the virus reactivation cascade delaying the onset of virus replication induced cytopathic effect. Herpesviruses are known to reactivate in response to different kinds of stress, and our study now highlights the molecular events in the stressed host cell that KSHV has evolved to utilize to ensure efficient viral lytic replication.

  9. Crystal structure and mechanism of the lytic transglycosylase MltA from Escherichia coli

    NARCIS (Netherlands)

    van Straaten, Karin

    2006-01-01

    This thesis describes the determination and analysis of the 3D-structure of the lytic transglycosylase MltA from Escherichia coli by X-ray crystallography. This work aims to further increase our knowledge of the molecular details of the cleaving mechanism and the typical 1,6- anhydromuropeptide prod

  10. Structure and boosting activity of a starch-degrading lytic polysaccharide monooxygenase

    DEFF Research Database (Denmark)

    Lo Leggio, Leila; Simmons, Thomas J.; Poulsen, Jens-Christian Navarro

    2015-01-01

    Lytic polysaccharide monooxygenases (LPMOs) are recently discovered enzymes that oxidatively deconstruct polysaccharides. LPMOs are fundamental in the effective utilization of these substrates by bacteria and fungi; moreover, the enzymes have significant industrial importance. We report here...... substrate to maltose by β-amylase. The detailed structure of the enzyme's active site yields insights into the mechanism of action of this important class of enzymes....

  11. Pain relief with percutaneous trochanteroplasty in a patient with bilateral trochanteric myelomatous lytic lesions.

    Science.gov (United States)

    Wahezi, Sayed E; Silva, Kyle; Najafi, Shervin

    2015-01-01

    Multiple myeloma is a hematologic malignancy associated with destructive bone loss. Lytic lesions, a hallmark of this cancer, can result in significant morbidity because of associated pain and structural osseous compromise. Osteoplasty has demonstrated efficacy in the treatment of myelomatous pain within the axial skeleton; however, there is limited evidence supporting the utility of osteoplasty to treat extra-spinal lesions. We describe a 67 year-old woman with stable IgA lambda multiple myeloma with sentinel bilateral greater trochanteric lytic lesions that was referred to our interventional pain management clinic for evaluation of bilateral lateral hip pain. Conservative treatment options including physical therapy, non-steroidal anti-inflammatory drugs (NSAIDs), oral opiates, and local corticosteroid injections to bilateral trochanteric bursae failed to offer pain relief. The patient underwent minimally invasive percutaneous trochanteroplasty with concomitant core biopsy of her bilateral trochanteric lytic lesions. The intended goals of this novel procedure were to determine the cause of the suspected lytic lesions, provide pain relief, and offer structural stability by safely implanting bone cement as part of a fracture prevention strategy. At 12 month follow-up, the patient's pain improved by 70% and she no longer required the use of pain medication. The patient also displayed a significant improvement in her day-to-day functioning and quality of life.

  12. The importance of lytic and nonlytic immune responses in viral infections

    DEFF Research Database (Denmark)

    Wodarz, Dominik; Christensen, Jan Pravsgaard; Thomsen, Allan Randrup

    2002-01-01

    Antiviral immune effector mechanisms can be divided broadly into lytic and nonlytic components. We use mathematical models to investigate the fundamental question of which type of response is required to combat different types of viral infection. According to our model, the relative roles...

  13. Oncogenic Herpesvirus Utilizes Stress-Induced Cell Cycle Checkpoints for Efficient Lytic Replication.

    Science.gov (United States)

    Balistreri, Giuseppe; Viiliäinen, Johanna; Turunen, Mikko; Diaz, Raquel; Lyly, Lauri; Pekkonen, Pirita; Rantala, Juha; Ojala, Krista; Sarek, Grzegorz; Teesalu, Mari; Denisova, Oxana; Peltonen, Karita; Julkunen, Ilkka; Varjosalo, Markku; Kainov, Denis; Kallioniemi, Olli; Laiho, Marikki; Taipale, Jussi; Hautaniemi, Sampsa; Ojala, Päivi M

    2016-02-01

    Kaposi's sarcoma herpesvirus (KSHV) causes Kaposi's sarcoma and certain lymphoproliferative malignancies. Latent infection is established in the majority of tumor cells, whereas lytic replication is reactivated in a small fraction of cells, which is important for both virus spread and disease progression. A siRNA screen for novel regulators of KSHV reactivation identified the E3 ubiquitin ligase MDM2 as a negative regulator of viral reactivation. Depletion of MDM2, a repressor of p53, favored efficient activation of the viral lytic transcription program and viral reactivation. During lytic replication cells activated a p53 response, accumulated DNA damage and arrested at G2-phase. Depletion of p21, a p53 target gene, restored cell cycle progression and thereby impaired the virus reactivation cascade delaying the onset of virus replication induced cytopathic effect. Herpesviruses are known to reactivate in response to different kinds of stress, and our study now highlights the molecular events in the stressed host cell that KSHV has evolved to utilize to ensure efficient viral lytic replication.

  14. Crystal structure and mechanism of the lytic transglycosylase MltA from Escherichia coli

    NARCIS (Netherlands)

    van Straaten, Karin

    2006-01-01

    This thesis describes the determination and analysis of the 3D-structure of the lytic transglycosylase MltA from Escherichia coli by X-ray crystallography. This work aims to further increase our knowledge of the molecular details of the cleaving mechanism and the typical 1,6- anhydromuropeptide prod

  15. Characterization of the lytic-lysogenic switch of the lactococcal bacteriophage Tuc2009

    NARCIS (Netherlands)

    Kenny, JG; Leach, S; de la Hoz, AB; Venema, G; Kok, J; Fitzgerald, GF; Nauta, A; Alonso, JC; van Sinderen, D; Kenny, John G.; Hoz, Ana B. de la; Fitzgerald, Gerald F.; Alonso, Juan C.

    2006-01-01

    Tuc2009 is a temperate bacteriophage of Lactococcus lactis subsp. cremoris UC509 which encodes a CI- and Cro-type lysogenic-lytic switch region. A helix-swap of the 0 helices of the closely related Cl-type proteins from the lactococcal phages r1t and Tuc2009 revealed the crucial elements involved in

  16. STUDIES ON THE BACTERIOPHAGE OF D'HERELLE : I. IS THE LYTIC PRINCIPLE VOLATILE?

    Science.gov (United States)

    Bronfenbrenner, J J; Korb, C

    1925-01-01

    The lytic principle concerned in the phenomenon of transmissible lysis is not volatile. The results which have been taken to indicate volatility are, in our opinion, to be attributed to the transfer to the distillate of minute droplets of the original active filtrate.

  17. Textiles for protection against microorganism

    Science.gov (United States)

    Sauperl, O.

    2016-04-01

    Concerning micro-organisms such as bacteria, viruses and fungi, there is a huge progress in the development of textile materials and procedures which should effectively protect against these various pathogens. In this sense there is especially problematic hospital environment, where it is necessary to take into account properly designed textile material which, when good selected and composed, act as a good barrier against transfer of micro-organisms through material mainly in its wet state. Respect to this it is necessary to be familiar with the rules regarding selection of the input material, the choice of proper yarn construction, the choice of the proper weaving mode, the rules regarding selection of antimicrobial-active compound suitable for (eco-friendly) treatment, and the choice of the most appropriate test method by which it is possible objectively to conclude on the reduction of selected microorganism. As is well known, fabrics are three-dimensional structures with void and non-void areas. Therefore, the physical-chemical properties of the textile material/fabric, the surface characteristics together with the shape of microorganism, and the carriers' characteristics contribute to control the transfer of microorganism through textile material. Therefore, careful planning of textile materials and treatment procedure with the compound which is able to reduce micro-organism satisfactory is particularly important, especially due to the fact that in hospital environment population with impaired immune system is mainly presented.

  18. Why are some microorganisms boring?

    Science.gov (United States)

    Cockell, Charles S; Herrera, Aude

    2008-03-01

    Microorganisms from diverse environments actively bore into rocks, contributing significantly to rock weathering. Carbonates are the most common substrate into which they bore, although there are also reports of microbial borings into volcanic glass. One of the most intriguing questions in microbial evolutionary biology is why some microorganisms bore. A variety of possible selection pressures, including nutrient acquisition, protection from UV radiation and predatory grazing could promote boring. None of these pressures is mutually exclusive and many of them could have acted in concert with varying strengths in different environments to favour the development of microorganisms that bore. We suggest that microbial boring might have begun in some environments as a mechanism against entombment by mineralization.

  19. A comparative study on the activity of fungal lytic polysaccharide monooxygenases for the depolymerization of cellulose in soybean spent flakes

    DEFF Research Database (Denmark)

    Pierce, Brian; Wittrup Agger, Jane; Zhang, Zhenghong

    2017-01-01

    Lytic polysaccharide monooxygenases (LPMOs) are copper-dependent enzymes capable of the oxidative breakdown of polysaccharides. They are of industrial interest due to their ability to enhance the enzymatic depolymerization of recalcitrant substrates by glycoside hydrolases. In this paper, twenty-...

  20. Lytic and lysogenic infection of diverse Escherichia coli and Shigella strains with a verocytotoxigenic bacteriophage.

    Science.gov (United States)

    James, C E; Stanley, K N; Allison, H E; Flint, H J; Stewart, C S; Sharp, R J; Saunders, J R; McCarthy, A J

    2001-09-01

    A verocytotoxigenic bacteriophage isolated from a strain of enterohemorrhagic Escherichia coli O157, into which a kanamycin resistance gene (aph3) had been inserted to inactivate the verocytotoxin gene (vt2), was used to infect Enterobacteriaceae strains. A number of Shigella and E. coli strains were susceptible to lysogenic infection, and a smooth E. coli isolate (O107) was also susceptible to lytic infection. The lysogenized strains included different smooth E. coli serotypes of both human and animal origin, indicating that this bacteriophage has a substantial capacity to disseminate verocytotoxin genes. A novel indirect plaque assay utilizing an E. coli recA441 mutant in which phage-infected cells can enter only the lytic cycle, enabling detection of all infective phage, was developed.

  1. Oxygen Activation at the Active Site of a Fungal Lytic Polysaccharide Monooxygenase.

    Science.gov (United States)

    O'Dell, William B; Agarwal, Pratul K; Meilleur, Flora

    2017-01-16

    Lytic polysaccharide monooxygenases have attracted vast attention owing to their abilities to disrupt glycosidic bonds via oxidation instead of hydrolysis and to enhance enzymatic digestion of recalcitrant substrates including chitin and cellulose. We have determined high-resolution X-ray crystal structures of an enzyme from Neurospora crassa in the resting state and of a copper(II) dioxo intermediate complex formed in the absence of substrate. X-ray crystal structures also revealed "pre-bound" molecular oxygen adjacent to the active site. An examination of protonation states enabled by neutron crystallography and density functional theory calculations identified a role for a conserved histidine in promoting oxygen activation. These results provide a new structural description of oxygen activation by substrate free lytic polysaccharide monooxygenases and provide insights that can be extended to reactivity in the enzyme-substrate complex. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Participation of the lytic replicon in bacteriophage P1 plasmid maintenance.

    OpenAIRE

    1989-01-01

    P1 bacteriophage carries at least two replicons: a plasmid replicon and a viral lytic replicon. Since the isolated plasmid replicon can maintain itself stably at the low copy number characteristic of intact P1 prophage, it has been assumed that this replicon is responsible for driving prophage replication. We provide evidence that when replication from the plasmid replicon is prevented, prophage replication continues, albeit at a reduced rate. The residual plasmid replication is due to incomp...

  3. Involvement of Noxa in mediating cellular ER stress responses to lytic virus infection

    OpenAIRE

    2011-01-01

    Noxa is a Bcl-2 homology domain-containing pro-apoptotic mitochondrial protein. Noxa mRNA and protein expression are upregulated by dsRNA or virus, and ectopic Noxa expression enhances cellular sensitivity to virus or dsRNA-induced apoptosis. Here we demonstrate that Noxa null baby mouse kidney (BMK) cells are deficient in normal cytopathic response to lytic viruses, and that reconstitution of the knockout cells with wild type Noxa restored normal cytopathic responses. Noxa regulation by viru...

  4. How Cancer Cells Become Resistant to Cationic Lytic Peptides: It's the Sugar!

    Science.gov (United States)

    Pierce, Joshua G

    2017-02-16

    In this issue of Cell Chemical Biology, Ishikawa et al. (2017) demonstrate that the loss of cell-surface anionic saccharides can impart resistance toward anticancer peptides. This study provides the first insight into potential resistance mechanisms toward cationic lytic peptides and highlights the important, yet previously unappreciated, role cell-surface glycans can play in cellular resistance mechanisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Regulation of the Spore Cortex Lytic Enzyme SleB in Bacillus anthracis

    OpenAIRE

    2014-01-01

    Bacillus anthracis is the causative agent of the disease anthrax and poses a threat due to its potential to be used as a biological weapon. The spore form of this bacterium is an extremely resistant structure, making spore decontamination exceptionally challenging. During spore germination, nutrient germinants interact with Ger receptors, triggering a cascade of events. A crucial event in this process is degradation of the cortex peptidoglycan by germination-specific lytic enzymes (GSLEs),...

  6. Murine gamma-herpesvirus 68 hijacks MAVS and IKKbeta to initiate lytic replication.

    Directory of Open Access Journals (Sweden)

    Xiaonan Dong

    2010-07-01

    Full Text Available Upon viral infection, the mitochondrial antiviral signaling (MAVS-IKKbeta pathway is activated to restrict viral replication. Manipulation of immune signaling events by pathogens has been an outstanding theme of host-pathogen interaction. Here we report that the loss of MAVS or IKKbeta impaired the lytic replication of gamma-herpesvirus 68 (gammaHV68, a model herpesvirus for human Kaposi's sarcoma-associated herpesvirus and Epstein-Barr virus. gammaHV68 infection activated IKKbeta in a MAVS-dependent manner; however, IKKbeta phosphorylated and promoted the transcriptional activation of the gammaHV68 replication and transcription activator (RTA. Mutational analyses identified IKKbeta phosphorylation sites, through which RTA-mediated transcription was increased by IKKbeta, within the transactivation domain of RTA. Moreover, the lytic replication of recombinant gammaHV68 carrying mutations within the IKKbeta phosphorylation sites was greatly impaired. These findings support the conclusion that gammaHV68 hijacks the antiviral MAVS-IKKbeta pathway to promote viral transcription and lytic infection, representing an example whereby viral replication is coupled to host immune activation.

  7. Diversity of phage infection types and associated terminology: the problem with 'Lytic or lysogenic'.

    Science.gov (United States)

    Hobbs, Zack; Abedon, Stephen T

    2016-04-01

    Bacteriophages, or phages, are viruses of members of domain Bacteria. These viruses play numerous roles in shaping the diversity of microbial communities, with impact differing depending on what infection strategies specific phages employ. From an applied perspective, these especially are communities containing undesired or pathogenic bacteria that can be modified through phage-mediated bacterial biocontrol, that is, through phage therapy. Here we seek to categorize phages in terms of their infection strategies as well as review or suggest more descriptive, accurate or distinguishing terminology. Categories can be differentiated in terms of (1) whether or not virion release occurs (productive infections versus lysogeny, pseudolysogeny and/or the phage carrier state), (2) the means of virion release (lytic versus chronic release) and (3) the degree to which phages are genetically equipped to display lysogenic cycles (temperate versus non-temperate phages). We address in particular the use or overuse of what can be a somewhat equivocal phrase, 'Lytic or lysogenic', especially when employed as a means of distinguishing among phages types. We suggest that the implied dichotomy is inconsistent with both modern as well as historical understanding of phage biology. We consider, therefore, less ambiguous terminology for distinguishing between 'Lytic' versus 'Lysogenic' phage types.

  8. KSHV Targeted Therapy: An Update on Inhibitors of Viral Lytic Replication

    Directory of Open Access Journals (Sweden)

    Natacha Coen

    2014-11-01

    Full Text Available Kaposi’s sarcoma-associated herpesvirus (KSHV is the causative agent of Kaposi’s sarcoma, primary effusion lymphoma and multicentric Castleman’s disease. Since the discovery of KSHV 20 years ago, there is still no standard treatment and the management of virus-associated malignancies remains toxic and incompletely efficacious. As the majority of tumor cells are latently infected with KSHV, currently marketed antivirals that target the virus lytic cycle have shown inconsistent results in clinic. Nevertheless, lytic replication plays a major role in disease progression and virus dissemination. Case reports and retrospective studies have pointed out the benefit of antiviral therapy in the treatment and prevention of KSHV-associated diseases. As a consequence, potent and selective antivirals are needed. This review focuses on the anti-KSHV activity, mode of action and current status of antiviral drugs targeting KSHV lytic cycle. Among these drugs, different subclasses of viral DNA polymerase inhibitors and compounds that do not target the viral DNA polymerase are being discussed. We also cover molecules that target cellular kinases, as well as the potential of new drug targets and animal models for antiviral testing.

  9. Host transcript accumulation during lytic KSHV infection reveals several classes of host responses.

    Directory of Open Access Journals (Sweden)

    Sanjay Chandriani

    Full Text Available Lytic infection by Kaposi's sarcoma-associated herpesvirus (KSHV is associated with an extensive shutoff of host gene expression, mediated chiefly by accelerated mRNA turnover due to expression of the viral SOX protein. We have previously identified a small number of host mRNAs that can escape SOX-mediated degradation. Here we present a detailed, transcriptome-wide analysis of host shutoff, with careful microarray normalization to allow rigorous determination of the magnitude and extent of transcript loss. We find that the extent of transcript reduction represents a continuum of susceptibilities of transcripts to virus-mediated shutoff. Our results affirm that the levels of over 75% of host transcripts are substantially reduced during lytic infection, but also show that another approximately 20% of cellular mRNAs declines only slightly (less than 2-fold during the course of infection. Approximately 2% of examined cellular genes are strongly upregulated during lytic infection, most likely due to transcriptional induction of mRNAs that display intrinsic SOX-resistance.

  10. Isolation and characterization of lytic phages TSE1-3 against Enterobacter cloacae

    Directory of Open Access Journals (Sweden)

    Khawaja Komal Ameer

    2016-01-01

    Full Text Available The emergence of antibiotic resistant bacterial pathogens is becoming a major challenge for patient care. The utilization of alternative therapies for infectious diseases other than antibiotics is an urgent need of today medical practice. The utilization of lytic bacteriophages and their gene products as therapeutic agents against antibiotic resistant bacteria is one of the convincing alternative approaches. Here we present the isolation and characterization of three lytic bacteriophages TSE1-3 against Enterobacter cloacae from sewage effluent. The isolates maintained antibacterial activity for 10 hours of incubation followed by the development of phage resistance. Their stability at different temperatures and pH, established their possible application in phage therapy. The highest activity of the phages was observed at 37°C and pH 7.0, while they gave lytic activity up to 60°C. The latent period of all the TSE phages was 20 minutes, while the burst size was 360 for TSE1, 270 for TSE2 and 311 for TSE3. The phages were harboring double-stranded DNA larger than 12kb in size. Further research into the phages genome and proteins, animal experiments, delivery parameters and clinical trials may lead to their utilization in phage therapy.

  11. [Immobilized microorganisms and water purification].

    Science.gov (United States)

    Mogilevich, N F

    1995-01-01

    Advantages and disadvantages of cells of aerobic microorganisms immobilized by the type of adhesion and incorporation into the gel beads, the amount of retained biomass, limitations of diffusion of oxygen and nutrients, viability, morphology, biochemical properties are described. Immobilized biocatalysts are discussed in the aspect of their use in purification of sewage waters.

  12. Airborne microorganisms from waste containers.

    Science.gov (United States)

    Jedlicka, Sabrina S; Stravitz, David M; Lyman, Charles E

    2012-01-01

    In physician's offices and biomedical labs, biological waste is handled every day. This waste is disposed of in waste containers designed for holding red autoclave bags. The containers used in these environments are closed hands-free containers, often with a step pedal. While these containers protect the user from surface-borne microorganisms, the containers may allow airborne microorganisms to escape via the open/close mechanism because of the air current produced upon open/close cycles. In this study, the air current was shown to be sufficient to allow airborne escape of microorganisms held in the container, including Aspergillus niger. However, bacterial cultures, such as Escherichia coli and Lactococcus lactis did not escape. This may be due to the choice of bacterial cultures and the absence of solid waste, such as dust or other particulate matter in the waste containers, that such strains of bacteria could travel on during aerosolization. We compared these results to those obtained using a re-designed receptacle, which mimimizes air currents, and detected no escaping microorganisms. This study highlights one potential source of airborne contamination in labs, hospitals, and other environments that dispose of biological waste.

  13. Biofuel production by recombinant microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Liao, James C.; Atsumi, Shota; Cann, Anthony F.

    2017-07-04

    Provided herein are metabolically-modified microorganisms useful for producing biofuels. More specifically, provided herein are methods of producing high alcohols including isobutanol, 1-butanol, 1-propanol, 2-methyl-1-butanol, 3-methyl-1-butanol and 2-phenylethanol from a suitable substrate.

  14. Phosphate Biomineralization of Cambrian Microorganisms

    Science.gov (United States)

    McKay, David S.; Rozanov, Alexei Yu.; Hoover, Richard B.; Westall, Frances

    1998-01-01

    As part of a long term study of biological markers (biomarkers), we are documenting a variety of features which reflect the previous presence of living organisms. As we study meteorites and samples returned from Mars, our main clue to recognizing possible microbial material may be the presence of biomarkers rather than the organisms themselves. One class of biomarkers consists of biominerals which have either been precipitated directly by microorganisms, or whose precipitation has been influenced by the organisms. Such microbe-mediated mineral formation may include important clues to the size, shape, and environment of the microorganisms. The process of fossilization or mineralization can cause major changes in morphologies and textures of the original organisms. The study of fossilized terrestrial organisms can help provide insight into the interpretation of mineral biomarkers. This paper describes the results of investigations of microfossils in Cambrian phosphate-rich rocks (phosphorites) that were found in Khubsugul, Northern Mongolia.

  15. Smaller Fleas: Viruses of Microorganisms

    OpenAIRE

    Paul Hyman; Stephen T. Abedon

    2012-01-01

    Life forms can be roughly differentiated into those that are microscopic versus those that are not as well as those that are multicellular and those that, instead, are unicellular. Cellular organisms seem generally able to host viruses, and this propensity carries over to those that are both microscopic and less than truly multicellular. These viruses of microorganisms, or VoMs, in fact exist as the world’s most abundant somewhat autonomous genetic entities and include the viruses of domain B...

  16. Microorganism Utilization for Synthetic Milk

    Science.gov (United States)

    Morford, Megan A.; Khodadad, Christina L.; Caro, Janicce I.; Spencer, LaShelle E.; Richards, Jeffery T.; Strayer, Richard F.; Birmele, Michele N.; Wheeler, Raymond M.

    2014-01-01

    A desired architecture for long duration spaceflight, like aboard the International Space Station or for future missions to Mars, is to provide a supply of fresh food crops for the astronauts. However, some crops can create a high proportion of inedible plant waste. The main goal of the Synthetic Biology project, Cow in a Column, was to produce the components of milk (sugar, lipid, protein) from inedible plant waste by utilizing microorganisms (fungi, yeast, bacteria). Of particular interest was utilizing the valuable polysaccharide, cellulose, found in plant waste, to naturally fuel-through microorganism cellular metabolism- the creation of sugar (glucose), lipid (milk fat), and protein (casein) in order to produce a synthetic edible food product. Environmental conditions such as pH, temperature, carbon source, aeration, and choice microorganisms were optimized in the laboratory and the desired end-products, sugars and lipids, were analyzed. Trichoderma reesei, a known cellulolytic fungus, was utilized to drive the production of glucose, with the intent that the produced glucose would serve as the carbon source for milk fat production and be a substitute for the milk sugar lactose. Lipid production would be carried out by Rhodosporidium toruloides, yeast known to accumulate those lipids that are typically found in milk fat. Results showed that glucose and total lipid content were below what was expected during this phase of experimentation. In addition, individual analysis of six fatty acids revealed that the percentage of each fatty acid was lower than naturally produced bovine milk. Overall, this research indicates that microorganisms could be utilized to breakdown inedible solid waste to produce useable products. For future work, the production of the casein protein for milk would require the development of a genetically modified organism, which was beyond the scope of the original project. Additional trials would be needed to further refine the required

  17. Transformation of the insecticide teflubenzuron by microorganisms

    NARCIS (Netherlands)

    Finkelstein, Z.I.; Baskunov, B.P.; Rietjens, I.M.C.M.; Boersma, M.G.; Vervoort, J.; Golovleva, L.A.

    2001-01-01

    Transformation of teflubenzuron, the active component in the insecticide commercialized as Nomolt, by soil microorganisms was studied. It was shown that microorganisms, belonging to Bacillus, Alcaligenes, Pseudomonas and Acinetobacter genera are capable to perform the hydrolytic cleavage of the phen

  18. OPPORTUNISTIC MICROORGANISMS IN RHEUMATIC DISEASES

    Directory of Open Access Journals (Sweden)

    M. Yu. Gulneva

    2016-01-01

    Full Text Available The paper gives the data available in the literature on the role of opportunistic microorganisms (OMs in rheumatic diseases (RDs. OMs are anticipated to be involved as triggers initiating the development of chronic inflammation. Along with this, OMs in autoimmune diseases may play a defensive role through the interaction with Toll-like receptors and the activation of T cells that have suppressor activity. The possible involvement of OMs in the pathogenesis of RDs provides support not only the isolation of microorganisms, but also the detection of antibacterial antibodies of different classes. Of great importance are OMs in the etiology of comorbid infections, the risk of which is due to both the presence of autoimmune RDs and the necessity of using the drugs having immunosuppressive activity. The active clinical introduction of biological agents is followed by a rise in the rate and severity of different infections, including those caused by OMs. Having a marked biological and environmental plasticity, OMs are able to persist long when there are changes in the immune defense of patients with RDs. There is evidence for the higher adhesive properties and persistent potential of the microorganisms that colonize the body of patients with RDs. In the latter, OMs that are distinguished by pronounced antibiotic polyresistance are isolated, making the treatment and prevention of opportunistic infections more difficult in rheumatology. The results of the papers analyzed in the review suggest that the study of OMs in RDs is of practical importance.

  19. PROBIOTICS BASED ON TRANSGENIC MICROORGANISMS

    Directory of Open Access Journals (Sweden)

    S. А. Starovoitova

    2012-02-01

    Full Text Available Modern tendencies of recombinant microorganisms creation for obtaining on their basis a new effective biopreparations (probiotics with wider spectrum of biological and therapeutic properties were considered. A lot of attention was focused on the main genera of perspective bacteria for creation of recombinant probiotics particularly: Lactococcus, Bifidobac terium,Bacillus, Escherichia. The main created Ukrainian and foreign gene-modified strains, that are widely used today in creation of effective recombinant biopreparations were characterized. Some fundamental directions and methods of gene-modified strains obtaining, which are used in getting effective biopreparations that used for therapy and prophylactic illness were reported, under which this group of pharmaceutical drugs were not used earlier. The safety matters of probiotics using on basis of genemodified strains were examined. Medical and veterinary biopreparations on basis of recombinant microorganisms could be used directly and effectively for therapy and prophylaxis of different illness, beginning from disbacteriosis up to cardiovascular diseases. It is related with some probiotic microorganisms ability for lowering of serum cholesterol at the host organism.

  20. Secondary metabolites from marine microorganisms

    Directory of Open Access Journals (Sweden)

    KELECOM ALPHONSE

    2002-01-01

    Full Text Available After 40 years of intensive research, chemistry of marine natural products has become a mature field. Since 1995, there are signals of decreased interest in the search of new metabolites from traditional sources such as macroalgae and octocorals, and the number of annual reports on marine sponges stabilized. On the contrary, metabolites from microorganisms is a rapidly growing field, due, at least in part, to the suspicion that a number of metabolites obtained from algae and invertebrates may be produced by associated microorganisms. Studies are concerned with bacteria and fungi, isolated from seawater, sediments, algae, fish and mainly from marine invertebrates such as sponges, mollusks, tunicates, coelenterates and crustaceans. Although it is still to early to define tendencies, it may be stated that the metabolites from microorganisms are in most cases quite different from those produced by the invertebrate hosts. Nitrogenated metabolites predominate over acetate derivatives, and terpenes are uncommon. Among the latter, sesquiterpenes, diterpenes and carotenes have been isolated; among nitrogenated metabolites, amides, cyclic peptides and indole alkaloids predominate.

  1. Microorganism Reduction Methods in Meat Products

    OpenAIRE

    ZÁHOROVÁ, Jana

    2011-01-01

    In Bachelor thesis I deal with a theme of the influences on the reduction of microorganisms of meat products. First, I focused on the characteristics of individual organisms, the factors affecting their growth, incidence of microorganisms in meat, forms of microbial degradation and contamination of meat microorganisms in slaughterhouses. The next section deals with the means to fight against microorganisms and methods which can reduce their presence in meat products. In the end there is menti...

  2. Noncanonical microRNAs and endogenous siRNAs in lytic infection of murine gammaherpesvirus.

    Directory of Open Access Journals (Sweden)

    Jing Xia

    Full Text Available MicroRNA (miRNA and endogenous small interfering RNA (endo-siRNA are two essential classes of small noncoding RNAs (sncRNAs in eukaryotes. The class of miRNA is diverse and there exist noncanonical miRNAs that bypass the canonical miRNA biogenesis pathway. In order to identify noncanonical miRNAs and endo-siRNAs responding to virus infection and study their potential function, we sequenced small-RNA species from cells lytically infected with murine gammaherpesvirus 68 (MHV68. In addition to three novel canonical miRNAs in mouse, two antisense miRNAs in virus and 25 novel noncanonical miRNAs, including miRNAs derived from transfer RNAs, small nucleolar RNAs and introns, in the host were identified. These noncanonical miRNAs exhibited features distinct from that of canonical miRNAs in lengths of hairpins, base pairings and first nucleotide preference. Many of the novel miRNAs are conserved in mammals. Besides several known murine endo-siRNAs detected by the sequencing profiling, a novel locus in the mouse genome was identified to produce endo-siRNAs. This novel endo-siRNA locus is comprised of two tandem inverted B4 short interspersed nuclear elements (SINEs. Unexpectedly, the SINE-derived endo-siRNAs were found in a variety of sequencing data and virus-infected cells. Moreover, a murine miRNA was up-regulated more than 35 fold in infected than in mock-treated cells. The putative targets of the viral and the up-regulated murine miRNAs were potentially involved in processes of gene transcription and protein phosphorylation, and localized to membranes, suggesting their potential role in manipulating the host basal immune system during lytic infection. Our results extended the number of noncanonical miRNAs in mammals and shed new light on their potential functions of lytic infection of MHV68.

  3. Induction of Epstein-Barr Virus Lytic Replication by Recombinant Adenoviruses Expressing the Zebra Gene with EBV Specific Promoters

    Institute of Scientific and Technical Information of China (English)

    Lu CHEN; Juan YIN; Yi CHEN; Jiang ZHONG

    2005-01-01

    The latent Epstein-Barr virus (EBV) is found in the cells of many tumors. For example, EBV is detectable in almost all cases, and in almost all tumor cells, of non-keratinizing nasopharyngeal carcinoma.Activating the latent virus, which will result in its lytic replication and the death of tumor cells, is a potential approach for the treatment of EBV-associated cancers. In this study, three recombinant adenoviruses were constructed to express the Zebra gene, an EBV gene responsible for switching from the latent state to lytic replication. EBV-specific promoters were used in order to limit Zebra expression in EBV-positive cells, and reduce the potential side effects. The EBV promoters used were Cp, Zp and a dual promoter combining both promoters, CpZp. The Zebra protein was detected in HEK293 cells as well as the EBV-positive D98-HR1 cells infected with recombinant viruses. An EBV lytic replication early antigen, EA-D, was also detected in infected D98-HR1, implying the initiation of lytic replication. In the cell viability assay, Zebra-expressing adenoviruses had little effect on EBV-negative HeLa cells, while significantly reducing the cell viability and proliferation of D98-HR1 cells. The results indicate that EBV virus promoters can be used in adenovirus vectors to express the Zebra gene and induce EBV lytic replication in D98-HR1 cells.

  4. Structure and boosting activity of a starch-degrading lytic polysaccharide monooxygenase.

    Science.gov (United States)

    Lo Leggio, Leila; Simmons, Thomas J; Poulsen, Jens-Christian N; Frandsen, Kristian E H; Hemsworth, Glyn R; Stringer, Mary A; von Freiesleben, Pernille; Tovborg, Morten; Johansen, Katja S; De Maria, Leonardo; Harris, Paul V; Soong, Chee-Leong; Dupree, Paul; Tryfona, Theodora; Lenfant, Nicolas; Henrissat, Bernard; Davies, Gideon J; Walton, Paul H

    2015-01-22

    Lytic polysaccharide monooxygenases (LPMOs) are recently discovered enzymes that oxidatively deconstruct polysaccharides. LPMOs are fundamental in the effective utilization of these substrates by bacteria and fungi; moreover, the enzymes have significant industrial importance. We report here the activity, spectroscopy and three-dimensional structure of a starch-active LPMO, a representative of the new CAZy AA13 family. We demonstrate that these enzymes generate aldonic acid-terminated malto-oligosaccharides from retrograded starch and boost significantly the conversion of this recalcitrant substrate to maltose by β-amylase. The detailed structure of the enzyme's active site yields insights into the mechanism of action of this important class of enzymes.

  5. Regulation of latency to lytic life cycle:multiple tricks by KSHV RTA

    Institute of Scientific and Technical Information of China (English)

    Jiemin Wong

    2010-01-01

    @@ Higher Education Press and Springer-Verlag Berlin Heidelberg 2010The herpesviruses are large enveloped DNA viruses that infect a wide spectrum hosts including human being. A key characteristic of all herpesviruses is their ability to establish life-time latency within the infected host and to periodically reactivate and enter the iytic replication to produce infectious virus progeny. During latency the 120-300 kb double-stranded DNA genomes of these viruses are maintained as multiple copies of circular episomes within the nuclei of the host cells. Lytic replication is marked by an increase in viral gene expression and the production of infectious virus progeny.

  6. Trametes suaveolens as ligninolytic enzyme producer

    Directory of Open Access Journals (Sweden)

    Knežević Aleksandar

    2013-01-01

    Full Text Available Species of the genus Trametes represent one of the most efficient lignin-degraders which can be attributed to a well developed ligninolytic enzyme system. Current trends are screening of ability of new species to produce these enzymes, as well as the optimization of conditions for their overproduction. Therefore, the aim of the study was to evaluate the potential of T. suaveolens to synthesize laccase and Mn-oxidizing peroxidases during fermentation of the selected plant raw materials. Level of enzyme activities was measured on 7, 10 and 14th day of submersion, as well as the solid-state fermentation of wheat straw and oak sawdust in the presence of NH4NO3 in previously determined optimal nitrogen concentration of 25 mM. The enzyme activity was determined spectrophotometrically using ABTS and phenol red as the substrates. The highest level of laccase activity (1087.1 U/L was noted after 7 days of wheat straw solid-state fermentation, while during the submerged cultivation the production of the enzyme was not noted. Submerged cultivation in oak sawdust-enriched medium was the optimal for activity of Mn-dependent peroxidase (1767.7 U/L on day 14 and Mn-independent peroxidase (1113.7 U/L on day 7. Introduction of T. suaveolens to produce ligninolytic enzyme represented the base for further study, as well as the determination of relation between enzyme activity and rate of lignin degradation. It could lead to greater possibility of fungal species selection with high delignification capacity, which could take participation in sustainable production of food, feed, fibres, and energy, environmentally friendly pollution prevention, and bioremediation.

  7. Identification of Novel Small Organic Compounds with Diverse Structures for the Induction of Epstein-Barr Virus (EBV) Lytic Cycle in EBV-Positive Epithelial Malignancies.

    Science.gov (United States)

    Choi, Chung King; Ho, Dona N; Hui, Kwai Fung; Kao, Richard Y; Chiang, Alan K S

    2015-01-01

    Phorbol esters, which are protein kinase C (PKC) activators, and histone deacetylase (HDAC) inhibitors, which cause enhanced acetylation of cellular proteins, are the main classes of chemical inducers of Epstein-Barr virus (EBV) lytic cycle in latently EBV-infected cells acting through the PKC pathway. Chemical inducers which induce EBV lytic cycle through alternative cellular pathways may aid in defining the mechanisms leading to lytic cycle reactivation and improve cells' responsiveness towards lytic induction. We performed a phenotypic screening on a chemical library of 50,240 novel small organic compounds to identify novel class(es) of strong inducer(s) of EBV lytic cycle in gastric carcinoma (GC) and nasopharyngeal carcinoma (NPC) cells. Five hit compounds were selected after three successive rounds of increasingly stringent screening. All five compounds are structurally diverse from each other and distinct from phorbol esters or HDAC inhibitors. They neither cause hyperacetylation of histone proteins nor significant PKC activation at their working concentrations, suggesting that their biological mode of action are distinct from that of the known chemical inducers. Two of the five compounds with rapid lytic-inducing action were further studied for their mechanisms of induction of EBV lytic cycle. Unlike HDAC inhibitors, lytic induction by both compounds was not inhibited by rottlerin, a specific inhibitor of PKCδ. Interestingly, both compounds could cooperate with HDAC inhibitors to enhance EBV lytic cycle induction in EBV-positive epithelial cancer cells, paving way for the development of strategies to increase cells' responsiveness towards lytic reactivation. One of the two compounds bears structural resemblance to iron chelators and the other strongly activates the MAPK pathways. These structurally diverse novel organic compounds may represent potential new classes of chemicals that can be used to investigate any alternative mechanism(s) leading to EBV

  8. Protozoacidal Trojan-Horse: use of a ligand-lytic peptide for selective destruction of symbiotic protozoa within termite guts.

    Science.gov (United States)

    Sethi, Amit; Delatte, Jennifer; Foil, Lane; Husseneder, Claudia

    2014-01-01

    For novel biotechnology-based termite control, we developed a cellulose bait containing freeze-dried genetically engineered yeast which expresses a protozoacidal lytic peptide attached to a protozoa-recognizing ligand. The yeast acts as a 'Trojan-Horse' that kills the cellulose-digesting protozoa in the termite gut, which leads to the death of termites, presumably due to inefficient cellulose digestion. The ligand targets the lytic peptide specifically to protozoa, thereby increasing its protozoacidal efficiency while protecting non-target organisms. After ingestion of the bait, the yeast propagates in the termite's gut and is spread throughout the termite colony via social interactions. This novel paratransgenesis-based strategy could be a good supplement for current termite control using fortified biological control agents in addition to chemical insecticides. Moreover, this ligand-lytic peptide system could be used for drug development to selectively target disease-causing protozoa in humans or other vertebrates.

  9. Genomic sequence and evolution of marine cyanophage P60: a new insight on lytic and lysogenic phages.

    Science.gov (United States)

    Chen, Feng; Lu, Jingrang

    2002-05-01

    The genome of cyanophage P60, a lytic virus which infects marine Synechococcus WH7803, was completely sequenced. The P60 genome contained 47,872 bp with 80 potential open reading frames that were mostly similar to the genes found in lytic phages like T7, phi-YeO3-12, and SIO1. The DNA replication system, consisting of primase-helicase and DNA polymerase, appeared to be more conserved in podoviruses than in siphoviruses and myoviruses, suggesting that DNA replication genes could be the critical elements for lytic phages. Strikingly high sequence similarities in the regions coding for nucleotide metabolism were found between cyanophage P60 and marine unicellular cyanobacteria.

  10. Epstein-Barr virus (EBV Rta-mediated EBV and Kaposi's sarcoma-associated herpesvirus lytic reactivations in 293 cells.

    Directory of Open Access Journals (Sweden)

    Yen-Ju Chen

    Full Text Available Epstein-Barr virus (EBV Rta belongs to a lytic switch gene family that is evolutionarily conserved in all gamma-herpesviruses. Emerging evidence indicates that cell cycle arrest is a common means by which herpesviral immediate-early protein hijacks the host cell to advance the virus's lytic cycle progression. To examine the role of Rta in cell cycle regulation, we recently established a doxycycline (Dox-inducible Rta system in 293 cells. In this cell background, inducible Rta modulated the levels of signature G1 arrest proteins, followed by induction of the cellular senescence marker, SA-β-Gal. To delineate the relationship between Rta-induced cell growth arrest and EBV reactivation, recombinant viral genomes were transferred into Rta-inducible 293 cells. Somewhat unexpectedly, we found that Dox-inducible Rta reactivated both EBV and Kaposi's sarcoma-associated herpesvirus (KSHV, to similar efficacy. As a consequence, the Rta-mediated EBV and KSHV lytic replication systems, designated as EREV8 and ERKV, respectively, were homogenous, robust, and concurrent with cell death likely due to permissive lytic replication. In addition, the expression kinetics of EBV lytic genes in Dox-treated EREV8 cells was similar to that of their KSHV counterparts in Dox-induced ERKV cells, suggesting that a common pathway is used to disrupt viral latency in both cell systems. When the time course was compared, cell cycle arrest was achieved between 6 and 48 h, EBV or KSHV reactivation was initiated abruptly at 48 h, and the cellular senescence marker was not detected until 120 h after Dox treatment. These results lead us to hypothesize that in 293 cells, Rta-induced G1 cell cycle arrest could provide (1 an ideal environment for virus reactivation if EBV or KSHV coexists and (2 a preparatory milieu for cell senescence if no viral genome is available. The latter is hypothetical in a transient-lytic situation.

  11. Epstein-Barr virus (EBV) Rta-mediated EBV and Kaposi's sarcoma-associated herpesvirus lytic reactivations in 293 cells.

    Science.gov (United States)

    Chen, Yen-Ju; Tsai, Wan-Hua; Chen, Yu-Lian; Ko, Ying-Chieh; Chou, Sheng-Ping; Chen, Jen-Yang; Lin, Su-Fang

    2011-03-10

    Epstein-Barr virus (EBV) Rta belongs to a lytic switch gene family that is evolutionarily conserved in all gamma-herpesviruses. Emerging evidence indicates that cell cycle arrest is a common means by which herpesviral immediate-early protein hijacks the host cell to advance the virus's lytic cycle progression. To examine the role of Rta in cell cycle regulation, we recently established a doxycycline (Dox)-inducible Rta system in 293 cells. In this cell background, inducible Rta modulated the levels of signature G1 arrest proteins, followed by induction of the cellular senescence marker, SA-β-Gal. To delineate the relationship between Rta-induced cell growth arrest and EBV reactivation, recombinant viral genomes were transferred into Rta-inducible 293 cells. Somewhat unexpectedly, we found that Dox-inducible Rta reactivated both EBV and Kaposi's sarcoma-associated herpesvirus (KSHV), to similar efficacy. As a consequence, the Rta-mediated EBV and KSHV lytic replication systems, designated as EREV8 and ERKV, respectively, were homogenous, robust, and concurrent with cell death likely due to permissive lytic replication. In addition, the expression kinetics of EBV lytic genes in Dox-treated EREV8 cells was similar to that of their KSHV counterparts in Dox-induced ERKV cells, suggesting that a common pathway is used to disrupt viral latency in both cell systems. When the time course was compared, cell cycle arrest was achieved between 6 and 48 h, EBV or KSHV reactivation was initiated abruptly at 48 h, and the cellular senescence marker was not detected until 120 h after Dox treatment. These results lead us to hypothesize that in 293 cells, Rta-induced G1 cell cycle arrest could provide (1) an ideal environment for virus reactivation if EBV or KSHV coexists and (2) a preparatory milieu for cell senescence if no viral genome is available. The latter is hypothetical in a transient-lytic situation.

  12. Simian virus 40 late proteins possess lytic properties that render them capable of permeabilizing cellular membranes.

    Science.gov (United States)

    Daniels, Robert; Rusan, Nasser M; Wilbuer, Anne-Kathrin; Norkin, Leonard C; Wadsworth, Patricia; Hebert, Daniel N

    2006-07-01

    Many nonenveloped viruses have evolved an infectious cycle that culminates in the lysis or permeabilization of the host to enable viral release. How these viruses initiate the lytic event is largely unknown. Here, we demonstrated that the simian virus 40 progeny accumulated at the nuclear envelope prior to the permeabilization of the nuclear, endoplasmic reticulum, and plasma membranes at a time which corresponded with the release of the progeny. The permeabilization of these cellular membranes temporally correlated with late protein expression and was not observed upon the inhibition of their synthesis. To address whether one or more of the late proteins possessed an inherent capacity to induce membrane permeabilization, we examined the permeability of Escherichia coli that separately expressed the late proteins. VP2 and VP3, but not VP1, caused the permeabilization of bacterial membranes. Additionally, VP3 expression resulted in bacterial cell lysis. These findings demonstrate that VP3 possesses an inherent lytic property that is independent of eukaryotic signaling or cell death pathways.

  13. Calcium Signaling throughout the Toxoplasma gondii Lytic Cycle: A STUDY USING GENETICALLY ENCODED CALCIUM INDICATORS.

    Science.gov (United States)

    Borges-Pereira, Lucas; Budu, Alexandre; McKnight, Ciara A; Moore, Christina A; Vella, Stephen A; Hortua Triana, Miryam A; Liu, Jing; Garcia, Celia R S; Pace, Douglas A; Moreno, Silvia N J

    2015-11-01

    Toxoplasma gondii is an obligate intracellular parasite that invades host cells, creating a parasitophorous vacuole where it communicates with the host cell cytosol through the parasitophorous vacuole membrane. The lytic cycle of the parasite starts with its exit from the host cell followed by gliding motility, conoid extrusion, attachment, and invasion of another host cell. Here, we report that Ca(2+) oscillations occur in the cytosol of the parasite during egress, gliding, and invasion, which are critical steps of the lytic cycle. Extracellular Ca(2+) enhances each one of these processes. We used tachyzoite clonal lines expressing genetically encoded calcium indicators combined with host cells expressing transiently expressed calcium indicators of different colors, and we measured Ca(2+) changes in both parasites and host simultaneously during egress. We demonstrated a link between cytosolic Ca(2+) oscillations in the host and in the parasite. Our approach also allowed us to measure two new features of motile parasites, which were enhanced by Ca(2+) influx. This is the first study showing, in real time, Ca(2+) signals preceding egress and their direct link with motility, an essential virulence trait.

  14. CTCF interacts with the lytic HSV-1 genome to promote viral transcription

    Science.gov (United States)

    Lang, Fengchao; Li, Xin; Vladimirova, Olga; Hu, Benxia; Chen, Guijun; Xiao, Yu; Singh, Vikrant; Lu, Danfeng; Li, Lihong; Han, Hongbo; Wickramasinghe, J. M. A. S. P.; Smith, Sheryl T.; Zheng, Chunfu; Li, Qihan; Lieberman, Paul M.; Fraser, Nigel W.; Zhou, Jumin

    2017-01-01

    CTCF is an essential chromatin regulator implicated in important nuclear processes including in nuclear organization and transcription. Herpes Simplex Virus-1 (HSV-1) is a ubiquitous human pathogen, which enters productive infection in human epithelial and many other cell types. CTCF is known to bind several sites in the HSV-1 genome during latency and reactivation, but its function has not been defined. Here, we report that CTCF interacts extensively with the HSV-1 DNA during lytic infection by ChIP-seq, and its knockdown results in the reduction of viral transcription, viral genome copy number and virus yield. CTCF knockdown led to increased H3K9me3 and H3K27me3, and a reduction of RNA pol II occupancy on viral genes. Importantly, ChIP-seq analysis revealed that there is a higher level of CTD Ser2P modified RNA Pol II near CTCF peaks relative to the Ser5P form in the viral genome. Consistent with this, CTCF knockdown reduced the Ser2P but increased Ser5P modified forms of RNA Pol II on viral genes. These results suggest that CTCF promotes HSV-1 lytic transcription by facilitating the elongation of RNA Pol II and preventing silenced chromatin on the viral genome. PMID:28045091

  15. Viroporin potential of the lentivirus lytic peptide (LLP domains of the HIV-1 gp41 protein

    Directory of Open Access Journals (Sweden)

    Garry Robert F

    2007-11-01

    Full Text Available Abstract Background Mechanisms by which HIV-1 mediates reductions in CD4+ cell levels in infected persons are being intensely investigated, and have broad implications for AIDS drug and vaccine development. Virally induced changes in membrane ionic permeability induced by lytic viruses of many families contribute to cytopathogenesis. HIV-1 induces disturbances in plasma membrane ion transport. The carboxyl terminus of TM (gp41 contains potential amphipathic α-helical motifs identified through their structural similarities to naturally occurring cytolytic peptides. These sequences have been dubbed lentiviral lytic peptides (LLP -1, -2, and -3. Results Peptides corresponding to the LLP domains (from a clade B virus partition into lipid membranes, fold into α-helices and disrupt model membrane permeability. A peptide corresponding to the LLP-1 domain of a clade D HIV-1 virus, LLP-1D displayed similar activity to the LLP-1 domain of the clade B virus in all assays, despite a lack of amino acid sequence identity. Conclusion These results suggest that the C-terminal domains of HIV-1 Env proteins may form an ion channel, or viroporin. Increased understanding of the function of LLP domains and their role in the viral replication cycle could allow for the development of novel HIV drugs.

  16. Parosteal osteosarcoma dedifferentiating into telangiectatic osteosarcoma: importance of lytic changes and fluid cavities at imaging

    Energy Technology Data Exchange (ETDEWEB)

    Azura, M. [Istituto Ortopedico Rizzoli, Musculoskeletal Oncological Surgery Department, Bologna (Italy); University of Malaya, Department of Orthopaedic Surgery, Kuala Lumpur (Malaysia); Vanel, D. [Radiology, Istituto Ortopedico Rizzoli, Bologna (Italy); Istituti Rizzoli, Anatomia Patologica, Bologna (Italy); Alberghini, M. [Pathology, Istituto Ortopedico Rizzoli, Bologna (Italy); Picci, P.; Staals, E.; Mercuri, M. [Istituto Ortopedico Rizzoli, Musculoskeletal Oncological Surgery Department, Bologna (Italy)

    2009-07-15

    This study was performed to assess the imaging findings in cases of parosteal osteosarcoma dedifferentiated into telangiectatic osteosarcoma. Parosteal osteosarcoma is a low-grade well-differentiated malignant tumor. Dedifferentiation into a more aggressive lesion is frequent and usually visible on imaging as a central lytic area in a sclerotic mass. Only one case of differentiation into a telangiectatic osteosarcoma has been reported. As it has practical consequences, with a need for aggressive chemotherapy, we looked for this rather typical imaging pattern. Review of 199 cases of surface osteosarcomas (including 86 parosteal, of which 23 were dedifferentiated) revealed lesions suggesting a possible telangiectatic osteosarcoma on imaging examinations in five cases (cavities with fluid). Histology confirmed three cases (the two other only had hematoma inside a dedifferentiated tumor). There were three males, aged 24, 28, and 32. They had radiographs and CT, and two an MR examination. Lesions involved the distal femur, proximal tibia, and proximal humerus. The parosteal osteosarcoma was a sclerotic, regular mass, attached to the cortex. A purely lytic mass, partially composed of fluid cavities was easily detected on CT and MR. It involved the medullary cavity twice, and remained outside the bone once. Histology confirmed the two components in each case. Two patients died of pulmonary metastases and one is alive. Knowledge of this highly suggestive pattern should help guide the initial biopsy to diagnose the two components of the tumor, and guide aggressive treatment. (orig.)

  17. Overexpression of antimicrobial lytic peptides protects grapevine from Pierce's disease under greenhouse but not field conditions.

    Science.gov (United States)

    Li, Zhijian T; Hopkins, Donald L; Gray, Dennis J

    2015-10-01

    Pierce's disease (PD) caused by Xylella fastidiosa prevents cultivation of grapevine (Vitis vinifera) and susceptible hybrids in the southeastern United States and poses a major threat to the grape industry of California and Texas. Genetic resistance is the only proven control of X. fastidiosa. Genetic engineering offers an alternative to heretofore ineffective conventional breeding in order to transfer only PD resistance traits into elite cultivars. A synthetic gene encoding lytic peptide LIMA-A was introduced into V. vinifera and a Vitis hybrid to assess in planta inhibition of X. fastidiosa. Over 1050 independent transgenic plant lines were evaluated in the greenhouse, among which nine lines were selected and tested under naturally-inoculated field conditions. These selected plant lines in the greenhouse remain disease-free for 10 years, to date, even with multiple manual pathogen inoculations. However, all these lines in the field, including a grafted transgenic rootstock, succumbed to PD within 7 years. We conclude that in planta production of antimicrobial lytic peptides does not provide durable PD resistance to grapevine under field conditions.

  18. Preliminary survey of local bacteriophages with lytic activity against multi-drug resistant bacteria.

    Science.gov (United States)

    Latz, Simone; Wahida, Adam; Arif, Assuda; Häfner, Helga; Hoß, Mareike; Ritter, Klaus; Horz, Hans-Peter

    2016-10-01

    Bacteriophages (phages) represent a potential alternative for combating multi-drug resistant bacteria. Because of their narrow host range and the ever emergence of novel pathogen variants the continued search for phages is a prerequisite for optimal treatment of bacterial infections. Here we performed an ad hoc survey in the surroundings of a University hospital for the presence of phages with therapeutic potential. To this end, 16 aquatic samples of different origins and locations were tested simultaneously for the presence of phages with lytic activity against five current, but distinct strains each from the ESKAPE-group (i.e., Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter cloacae). Phages could be isolated for 70% of strains, covering all bacterial species except S. aureus. Apart from samples from two lakes, freshwater samples were largely devoid of phages. By contrast, one liter of hospital effluent collected at a single time point already contained phages active against two-thirds of tested strains. In conclusion, phages with lytic activity against nosocomial pathogens are unevenly distributed across environments with the prime source being the immediate hospital vicinity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Global mRNA degradation during lytic gammaherpesvirus infection contributes to establishment of viral latency.

    Directory of Open Access Journals (Sweden)

    Justin M Richner

    2011-07-01

    Full Text Available During a lytic gammaherpesvirus infection, host gene expression is severely restricted by the global degradation and altered 3' end processing of mRNA. This host shutoff phenotype is orchestrated by the viral SOX protein, yet its functional significance to the viral lifecycle has not been elucidated, in part due to the multifunctional nature of SOX. Using an unbiased mutagenesis screen of the murine gammaherpesvirus 68 (MHV68 SOX homolog, we isolated a single amino acid point mutant that is selectively defective in host shutoff activity. Incorporation of this mutation into MHV68 yielded a virus with significantly reduced capacity for mRNA turnover. Unexpectedly, the MHV68 mutant showed little defect during the acute replication phase in the mouse lung. Instead, the virus exhibited attenuation at later stages of in vivo infections suggestive of defects in both trafficking and latency establishment. Specifically, mice intranasally infected with the host shutoff mutant accumulated to lower levels at 10 days post infection in the lymph nodes, failed to develop splenomegaly, and exhibited reduced viral DNA levels and a lower frequency of latently infected splenocytes. Decreased latency establishment was also observed upon infection via the intraperitoneal route. These results highlight for the first time the importance of global mRNA degradation during a gammaherpesvirus infection and link an exclusively lytic phenomenon with downstream latency establishment.

  20. Investigating the lytic activity and structural properties of Staphylococcus aureus phenol soluble modulin (PSM) peptide toxins.

    Science.gov (United States)

    Laabei, Maisem; Jamieson, W David; Yang, Yi; van den Elsen, Jean; Jenkins, A Toby A

    2014-12-01

    The ubiquitous bacterial pathogen, Staphylococcus aureus, expresses a large arsenal of virulence factors essential for pathogenesis. The phenol-soluble modulins (PSMs) are a family of cytolytic peptide toxins which have multiple roles in staphylococcal virulence. To gain an insight into which specific factors are important in PSM-mediated cell membrane disruption, the lytic activity of individual PSM peptides against phospholipid vesicles and T cells was investigated. Vesicles were most susceptible to lysis by the PSMα subclass of peptides (α1-3 in particular), when containing between 10 and 30mol% cholesterol, which for these vesicles is the mixed solid ordered (so)-liquid ordered (lo) phase. Our results show that the PSMβ class of peptides has little effect on vesicles at concentrations comparable to that of the PSMα class and exhibited no cytotoxicity. Furthermore, within the PSMα class, differences emerged with PSMα4 showing decreased vesicle and cytotoxic activity in comparison to its counterparts, in contrast to previous studies. In order to understand this, peptides were studied using helical wheel projections and circular dichroism measurements. The degree of amphipathicity, alpha-helicity and properties such as charge and hydrophobicity were calculated, allowing a structure-function relationship to be inferred. The degree of alpha-helicity of the peptides was the single most important property of the seven peptides studied in predicting their lytic activity. These results help to redefine this class of peptide toxins and also highlight certain membrane parameters required for efficient lysis.

  1. Effect of metals on the lytic cycle of the coccolithovirus, EhV86.

    Directory of Open Access Journals (Sweden)

    Martha eGledhill

    2012-04-01

    Full Text Available In this study we show that metals, and in particular copper (Cu, can disrupt the lytic cycle in the Emiliania huxleyi - EhV86 host-virus system. Numbers of virus particles produced per E. huxleyi cell and E. huxleyi lysis rates were reduced by Cu at total metal concentrations over 500 nM in the presence of EDTA (ethylenediaminetetraacetic acid, and 250 nM in the absence of EDTA in acute short term exposure experiments. Zinc (Zn, cadmium (Cd and cobalt (Co were not observed to affect the lysis rate of EhV86 in these experiments. The cellular glutathione (GSH content increased in virus infected cells, but not as a result of metal exposure. In contrast, the cellular content of phytochelatins (PCs increased only in response to metal exposure. The increase in gluthatione content is consistent with increases in the production of reactive oxygen species (ROS on viral infection, while increases in PC content are likely linked to metal homeostasis and indicate that metal toxicity to the host was not affected by viral infection. We propose that Cu prevents lytic production of EhV86 by interfering with virus DNA (deoxyribonucleic acid synthesis through a transcriptional block, which ultimately suppresses the formation of ROS, a biochemical response required for successful virus infection.

  2. PARTIAL CHARACTERIZATION OF A LYTIC METHICILLIN RESISTANT-STAPHYLOCOCCUS AUREUS BACTERIOPHAGE

    Directory of Open Access Journals (Sweden)

    Sulaiman Al-Yousef

    2014-12-01

    Full Text Available A marked increase in the infection incidence caused by methicillin-resistant Staphylococcus aureus (MRSA strains has been noted in medical practice in recent years. This study was conducted to study the biological and characterize of MRSA-phage. Methicillin resistance of Staphylococcus aureus was detected and confirmed by determining of the MIC of oxacillin by the standard agar dilution method. Phage was biologically purified using single plaque technique, then phage characterization were studied using host range, adsorption time, particle morphology and its structural protein. MRSA phage showing lytic nature was purified by repeated plating after picking of single isolated plaques. This phage is active against all 11 isolates either of S. aureus or MRSA tested as hosts. Phage produced clear plaques indicating their lytic nature. This phage was concentrated employing polyethylene glycol (PEG-NaCl precipitation method. Morphologically, MRSA Phage has a hexagonal head having a long non-contractile tail, indicating his icosahedral nature. Adsorption studies showed 100% adsorption of MRSA-Phage after 35 minutes of exposure. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE experimentation indicated that the phage particles contain one major structural protein (about 30 Kda.

  3. Preparation and characterization of polyclonal antibody against Kaposi's sarcoma-associated herpesvirus lytic gene encoding RTA.

    Science.gov (United States)

    Fan, Weifei; Tang, Qiao; Shen, Chenyou; Qin, Di; Lu, Chun; Yan, Qin

    2015-11-01

    Replication and transcription activator (RTA) is a critical lytic protein encoded by Kaposi's sarcoma-associated herpesvirus (KSHV). To prepare rabbit polyclonal antibody against RTA, three antigenic polypeptides of KSHV RTA were initially synthesized. The fragment of RTA was cloned into p3FlagBsd to construct the recombinant plasmid, pRTA-Flag. 293 T and EA.hy926 cells were transfected with pRTA-Flag to obtain RTA-Flag fusion protein, which was detected using anti-Flag antibody. Next, New Zealand white rabbits were immunized with keyhole limpet hemocyanin-conjugated peptides to generate polyclonal antibodies against RTA. Enzyme-linked immunosorbent assays were performed to characterize the polyclonal antibodies, and the titers of the polyclonal antibodies against RTA were greater than 1:11,000. Western blotting and immunofluorescence assay revealed that the prepared antibody reacted specifically with the RTA-Flag fusion protein as well as the native viral protein in KSHV-infected primary effusion lymphoma cells. Collectively, our work successfully constructed the recombinant expression vector, pRTA-Flag, and prepared the polyclonal antibody against RTA, which was valuable for investigating the biochemical and biological functions of the critical KSHV lytic gene.

  4. Bronchogenic adenocarcinoma presenting as a synchronous solitary lytic skull lesion with ischaemic stroke--case report and literature review.

    LENUS (Irish Health Repository)

    O'Connell, David

    2011-01-01

    The authors describe a rare case of metastatic bronchogenic adenocarcinoma in a 55-year-old man presenting with concomittant solitary lytic skull lesion and ischaemic stroke. Metastatic bronchogenic carcinoma is known to present as lytic skull lesions. Primary brain tumours are also known to cause ischaemic brain injury. An underlying stroke risk may be exagerated by cranial tumour surgery. Patients with brain tumours are well known to be predisposed to an increased risk of developing thromboembolic disease. It is unusual to see metastatic bronchogenic adenocarcinoma presenting as ischaemic stroke with a background of concomittant cerebral metastasis. The aetio-pathogenesis of this rare occurrence is discussed with a review of literature.

  5. MID2 can substitute for MID1 and control exocytosis of lytic granules in cytotoxic T cells

    DEFF Research Database (Denmark)

    Boding, Lasse; Hansen, Ann K; Meroni, Germana;

    2015-01-01

    We have recently shown that the E3 ubiquitin ligase midline 1 (MID1) is upregulated in murine cytotoxic lymphocytes (CTL), where it controls exocytosis of lytic granules and the killing capacity. Accordingly, CTL from MID1 knock-out (MID1(-/-)) mice have a 25-30% reduction in exocytosis of lytic...... granules and cytotoxicity compared to CTL from wild-type (WT) mice. We wondered why the MID1 gene knock-out did not affect exocytosis and cytotoxicity more severely and speculated whether MID2, a close homologue of MID1, might partially compensate for the loss of MID1 in MID1(-/-) CTL. Here, we showed...

  6. Cellulolytic Microorganisms from Thermal Environments

    Energy Technology Data Exchange (ETDEWEB)

    Vishnivetskaya, Tatiana A [ORNL; Raman, Babu [ORNL; Phelps, Tommy Joe [ORNL; Podar, Mircea [ORNL; Elkins, James G [ORNL

    2012-01-01

    Thermal, anaerobic environments rich in decaying plant material are a potential source of novel cellulolytic bacteria. Samples collected from geothermal aquifers in the Yellowstone National Park (YNP) were used to select for cellulolytic thermophiles. Laboratory enrichments on dilute-acid pretreated plant biomass (switchgrass, Populus), and crystalline cellulose (Avicel) resulted in the isolation of 247 environmental clones. The majority of individual clones were affiliated with the cellulolytic bacteria of phylum Firmicutes, followed by xylanolytic and saccharolytic members of the phylum Dictyoglomi. Among the Firmicutes, the clones were affiliated with the genera Caldicellulosiruptor (54.4%), Caloramator (11.5%), Thermoanaerobacter (8.8%), Thermovenabulum (4.1%), and Clostridium (2.0%). From established anaerobic thermophilic enrichments a total of 81 single strains of the genera Caldicellulosiruptor (57%) and Thermoanaerobacter (43%) were isolated. With continuous flow enrichment on Avicel, increases in the relative abundance of Caloramator sp. was observed over clones detected from the Caldicellulosiruptor. Complex communities of interacting microorganisms bring about cellulose decomposition in nature, therefore using up-to-date approaches may yield novel cellulolytic microorganisms with high activity and a rapid rate of biomass conversion to biofuels.

  7. The use of lytic bacteriophages to reduce E. coli O157:H7 on fresh cut lettuce introduced through cross-contamination

    Science.gov (United States)

    The role of lytic bacteriophages in preventing cross contamination of produce has not been evaluated. A cocktail of three lytic phages specific for E. coli O157:H7 (EcoShield) at 108 PFU/ml or a control (phosphate buffered saline, PBS) was applied to lettuce by either 1) spraying on to lettuce piec...

  8. Phage lysin LysK can be truncated to its CHAP domain and retain lytic activity against live antibiotic-resistant staphylococci.

    Science.gov (United States)

    Horgan, Marianne; O'Flynn, Gary; Garry, Jennifer; Cooney, Jakki; Coffey, Aidan; Fitzgerald, Gerald F; Ross, R Paul; McAuliffe, Olivia

    2009-02-01

    A truncated derivative of the phage endolysin LysK containing only the CHAP (cysteine- and histidine-dependent amidohydrolase/peptidase) domain exhibited lytic activity against live clinical staphylococcal isolates, including methicillin-resistant Staphylococcus aureus. This is the first known report of a truncated phage lysin which retains high lytic activity against live staphylococcal cells.

  9. Isolation and Characterization of Lytic Properties of Bacteriophages Specific for M. haemolytica Strains.

    Directory of Open Access Journals (Sweden)

    Renata Urban-Chmiel

    Full Text Available The objective of this study was isolation and morphological characterization of temperate bacteriophages obtained from M. haemolytica strains and evaluation of their lytic properties in vitro against M. haemolytica isolated from the respiratory tract of calves.The material for the study consisted of the reference strain M. haemolytica serotype 1 (ATCC® BAA-410™, reference serotypes A1, A2, A5, A6, A7, A9 and A11, and wild-type isolates of M. haemolytica. Bacteriophages were induced from an overnight bacterial starter culture of all examined M. haemolytica strains treated with mitomycin C. The lytic properties and host ranges were determined by plaque assays. The morphology of the bacteriophages was examined in negative-stained smears with 5% uranyl acetate solution using a transmission electron microscope. The genetic analysis of the bacteriophages was followed by restriction analysis of bacteriophage DNA. This was followed by analysis of genetic material by polymerase chain reaction (PCR.Eight bacteriophages were obtained, like typical of the families Myoviridae, Siphoviridae and Podoviridae. Most of the bacteriophages exhibited lytic properties against the M. haemolytica strains. Restriction analysis revealed similarities to the P2-like phage obtained from the strain M. haemolytica BAA-410. The most similar profiles were observed in the case of bacteriophages φA1 and φA5. All of the bacteriophages obtained were characterized by the presence of additional fragments in the restriction profiles with respect to the P2-like reference phage. In the analysis of PCR products for the P2-like reference phage phi-MhaA1-PHL101 (DQ426904 and the phages of the M. haemolytica serotypes, a 734-bp phage PCR product was obtained. The primers were programmed in Primer-Blast software using the structure of the sequence DQ426904 of reference phage PHL101.The results obtained indicate the need for further research aimed at isolating and characterizing

  10. Isolation and Characterization of Lytic Properties of Bacteriophages Specific for M. haemolytica Strains.

    Science.gov (United States)

    Urban-Chmiel, Renata; Wernicki, Andrzej; Stęgierska, Diana; Dec, Marta; Dudzic, Anna; Puchalski, Andrzej

    2015-01-01

    The objective of this study was isolation and morphological characterization of temperate bacteriophages obtained from M. haemolytica strains and evaluation of their lytic properties in vitro against M. haemolytica isolated from the respiratory tract of calves. The material for the study consisted of the reference strain M. haemolytica serotype 1 (ATCC®) BAA-410™, reference serotypes A1, A2, A5, A6, A7, A9 and A11, and wild-type isolates of M. haemolytica. Bacteriophages were induced from an overnight bacterial starter culture of all examined M. haemolytica strains treated with mitomycin C. The lytic properties and host ranges were determined by plaque assays. The morphology of the bacteriophages was examined in negative-stained smears with 5% uranyl acetate solution using a transmission electron microscope. The genetic analysis of the bacteriophages was followed by restriction analysis of bacteriophage DNA. This was followed by analysis of genetic material by polymerase chain reaction (PCR). Eight bacteriophages were obtained, like typical of the families Myoviridae, Siphoviridae and Podoviridae. Most of the bacteriophages exhibited lytic properties against the M. haemolytica strains. Restriction analysis revealed similarities to the P2-like phage obtained from the strain M. haemolytica BAA-410. The most similar profiles were observed in the case of bacteriophages φA1 and φA5. All of the bacteriophages obtained were characterized by the presence of additional fragments in the restriction profiles with respect to the P2-like reference phage. In the analysis of PCR products for the P2-like reference phage phi-MhaA1-PHL101 (DQ426904) and the phages of the M. haemolytica serotypes, a 734-bp phage PCR product was obtained. The primers were programmed in Primer-Blast software using the structure of the sequence DQ426904 of reference phage PHL101. The results obtained indicate the need for further research aimed at isolating and characterizing bacteriophages

  11. Functional Basis of Microorganism Classification.

    Directory of Open Access Journals (Sweden)

    Chengsheng Zhu

    2015-08-01

    Full Text Available Correctly identifying nearest "neighbors" of a given microorganism is important in industrial and clinical applications where close relationships imply similar treatment. Microbial classification based on similarity of physiological and genetic organism traits (polyphasic similarity is experimentally difficult and, arguably, subjective. Evolutionary relatedness, inferred from phylogenetic markers, facilitates classification but does not guarantee functional identity between members of the same taxon or lack of similarity between different taxa. Using over thirteen hundred sequenced bacterial genomes, we built a novel function-based microorganism classification scheme, functional-repertoire similarity-based organism network (FuSiON; flattened to fusion. Our scheme is phenetic, based on a network of quantitatively defined organism relationships across the known prokaryotic space. It correlates significantly with the current taxonomy, but the observed discrepancies reveal both (1 the inconsistency of functional diversity levels among different taxa and (2 an (unsurprising bias towards prioritizing, for classification purposes, relatively minor traits of particular interest to humans. Our dynamic network-based organism classification is independent of the arbitrary pairwise organism similarity cut-offs traditionally applied to establish taxonomic identity. Instead, it reveals natural, functionally defined organism groupings and is thus robust in handling organism diversity. Additionally, fusion can use organism meta-data to highlight the specific environmental factors that drive microbial diversification. Our approach provides a complementary view to cladistic assignments and holds important clues for further exploration of microbial lifestyles. Fusion is a more practical fit for biomedical, industrial, and ecological applications, as many of these rely on understanding the functional capabilities of the microbes in their environment and are less

  12. Biocorrosion produced by Thiobacillus-like microorganisms.

    Science.gov (United States)

    López, A I; Marín, I; Amils, R

    1994-01-01

    Biocorrosion can be produced by many different microorganisms through diverse mechanisms. The biocorrosion produced by acidophilic microorganisms of the genus Thiobacillus is based on the production of sulfuric acid and ferric ion from pyrites or related mineral structures, as a result of the chemolithotrophic metabolism of these microorganisms. The products of this aerobic respiration are also powerful oxidant elements, which can produce chemical oxidations of other metallic structures. The Tinto River, a very unusual extremophilic habitat (pH around 2, and high concentration of ferric ion), product of the growth of strict chemolithotrophic microorganisms, is discussed as a model case.

  13. Hepatocyte growth factor pathway upregulation in the bone marrow microenvironment in multiple myeloma is associated with lytic bone disease

    DEFF Research Database (Denmark)

    Kristensen, Ida B; Christensen, Jacob H; Lyng, Maria Bibi

    2013-01-01

    Lytic bone disease (LBD) in multiple myeloma (MM) is caused by osteoclast hyperactivation and osteoblast inhibition. Based on in vitro studies, the hepatocyte growth factor (HGF) pathway is thought to be central in osteoblast inhibition. We evaluated the gene expression of the HGF pathway in vivo...

  14. Lytic infection of Lactococcus lactis by bacteriophages Tuc2009 and c2 triggers alternative transcriptional host responses.

    Science.gov (United States)

    Ainsworth, Stuart; Zomer, Aldert; Mahony, Jennifer; van Sinderen, Douwe

    2013-08-01

    Here we present an entire temporal transcriptional profile of Lactococcus lactis subsp. cremoris UC509.9 undergoing lytic infection with two distinct bacteriophages, Tuc2009 and c2. Furthermore, corresponding high-resolution whole-phage genome tiling arrays of both bacteriophages were performed throughout lytic infection. Whole-genome microarrays performed at various time points postinfection demonstrated a rather modest impact on host transcription. The majority of changes in the host transcriptome occur during late infection stages; few changes in host gene transcription occur during the immediate and early infection stages. Alterations in the L. lactis UC509.9 transcriptome during lytic infection appear to be phage specific, with relatively few differentially transcribed genes shared between cells infected with Tuc2009 and those infected with c2. Despite the apparent lack of a coordinated general phage response, three themes common to both infections were noted: alternative transcription of genes involved in catabolic flux and energy production, differential transcription of genes involved in cell wall modification, and differential transcription of genes involved in the conversion of ribonucleotides to deoxyribonucleotides. The transcriptional profiles of both bacteriophages during lytic infection generally correlated with the findings of previous studies and allowed the confirmation of previously predicted promoter sequences. In addition, the host transcriptional response to lysogenization with Tuc2009 was monitored along with tiling array analysis of Tuc2009 in the lysogenic state. Analysis identified 44 host genes with altered transcription during lysogeny, 36 of which displayed levels of transcription significantly reduced from those for uninfected cells.

  15. Probing the structure of glucan lyases – the lytic members of GH31 - by sequence analysis, circular dichroism and proteolysis

    DEFF Research Database (Denmark)

    Ernst, Heidi; Lo Leggio, Leila; Yu, Shukun

    2005-01-01

    Glucan lyase (GL) is a polysaccharide lyase with unique characteristics. It is involved in an alternative pathway for the degradation of alpha-glucans, the anhydrofructose pathway. Sequence similarity suggests that this lytic enzyme belongs to glycoside hydrolase family 31, for which until very r...

  16. Lytic Infection of Lactococcus lactis by Bacteriophages Tuc2009 and c2 Triggers Alternative Transcriptional Host Responses

    NARCIS (Netherlands)

    Ainsworth, S.; Zomer, A.L.; Mahony, J.; Sinderen, D. van

    2013-01-01

    Here we present an entire temporal transcriptional profile of Lactococcus lactis subsp. cremoris UC509.9 undergoing lytic infection with two distinct bacteriophages, Tuc2009 and c2. Furthermore, corresponding high-resolution whole-phage genome tiling arrays of both bacteriophages were performed thro

  17. In vivo dynamics of EBNA1-oriP interaction during latent and lytic replication of Epstein-Barr virus.

    Science.gov (United States)

    Daikoku, Tohru; Kudoh, Ayumi; Fujita, Masatoshi; Sugaya, Yutaka; Isomura, Hiroki; Tsurumi, Tatsuya

    2004-12-24

    The Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) is required for maintenance of the viral genome DNA during the latent phase of EBV replication but continues to be synthesized after the induction of viral productive replication. An EBV genome-wide chromatin immunoprecipitation assay revealed that EBNA1 constantly binds to oriP of the EBV genome during not only latent but also lytic infection. Although the total levels of EBNA1 proved constant throughout the latter, the levels of the oriP-bound form were increased as lytic infection proceeded. EBV productive DNA replication occurs at discrete sites in nuclei, called replication compartments, where viral replication proteins are clustered. Confocal laser microscopic analyses revealed that whereas EBNA1 was distributed broadly in nuclei as fine punctate dots during the latent phase of infection, the protein became redistributed to the viral replication compartments and localized as distinct spots within and/or nearby the compartments after the induction of lytic replication. Taking these findings into consideration, oriP regions of the EBV genome might be organized by EBNA1 into replication domains that may set up scaffolding for lytic replication and transcription.

  18. Epiphyseal involvement in Erdheim-Chester disease: radiographic and scintigraphic findings in a case with lytic lesions

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Hernandez, G.; Tajahuerce-Romera, G.M.; Latorre-Ibanez, M.D.; Lara-Pomares, A. [Servicio de Medicina Nuclear, Hospital Provincial de Castellon (Spain); Vila-Fayos, V. [Servicio de Reumatologia, Hospital Comarcal de Vinaroz (Spain)

    2000-08-01

    We reported a symmetric increase of activity in lower links secondary to Erdheim-Chester disease and demonstrated by bone scans and radiographs. An inusual scintigraphic and radiographic appearance with epiphyseal involvement and lytic lesions is described. Differential diagnosis of bone scan and radiographic findings is discussed. (orig.)

  19. Oxidative cleavage and hydrolytic boosting of cellulose in soybean spent flakes by Trichoderma reesei Cel61A lytic polysaccharide monooxygenase

    DEFF Research Database (Denmark)

    Pierce, Brian; Wittrup Agger, Jane; Wichmann, Jesper

    2017-01-01

    The auxiliary activity family 9 (AA9) copper-dependent lytic polysaccharide monooxygenase (LPMO) from Trichoderma reesei (EG4; TrCel61A) was investigated for its ability to oxidize the complex polysaccharides from soybean. The substrate specificity of the enzyme was assessed against a variety...

  20. Lytic Infection of Lactococcus lactis by Bacteriophages Tuc2009 and c2 Triggers Alternative Transcriptional Host Responses

    NARCIS (Netherlands)

    Ainsworth, S.; Zomer, A.L.; Mahony, J.; Sinderen, D. van

    2013-01-01

    Here we present an entire temporal transcriptional profile of Lactococcus lactis subsp. cremoris UC509.9 undergoing lytic infection with two distinct bacteriophages, Tuc2009 and c2. Furthermore, corresponding high-resolution whole-phage genome tiling arrays of both bacteriophages were performed

  1. High resolution crystal structures of the Escherichia coli lytic transglycosylase Slt70 and its complex with a peptidoglycan fragment

    NARCIS (Netherlands)

    Asselt, Erik J. van; Thunnissen, Andy-Mark W.H.; Dijkstra, Bauke W.

    1999-01-01

    The 70 kDa soluble lytic transglycosylase (Slt70) from Escherichia coli is an exo-muramidase, that catalyses the cleavage of the glycosidic bonds between N-acetylmuramic acid and N-acetylglucosamine residues in peptidoglycan, the main structural component of the bacterial cell wall. This cleavage is

  2. A subset of replication proteins enhances origin recognition and lytic replication by the Epstein-Barr virus ZEBRA protein.

    Directory of Open Access Journals (Sweden)

    Ayman El-Guindy

    Full Text Available ZEBRA is a site-specific DNA binding protein that functions as a transcriptional activator and as an origin binding protein. Both activities require that ZEBRA recognizes DNA motifs that are scattered along the viral genome. The mechanism by which ZEBRA discriminates between the origin of lytic replication and promoters of EBV early genes is not well understood. We explored the hypothesis that activation of replication requires stronger association between ZEBRA and DNA than does transcription. A ZEBRA mutant, Z(S173A, at a phosphorylation site and three point mutants in the DNA recognition domain of ZEBRA, namely Z(Y180E, Z(R187K and Z(K188A, were similarly deficient at activating lytic DNA replication and expression of late gene expression but were competent to activate transcription of viral early lytic genes. These mutants all exhibited reduced capacity to interact with DNA as assessed by EMSA, ChIP and an in vivo biotinylated DNA pull-down assay. Over-expression of three virally encoded replication proteins, namely the primase (BSLF1, the single-stranded DNA-binding protein (BALF2 and the DNA polymerase processivity factor (BMRF1, partially rescued the replication defect in these mutants and enhanced ZEBRA's interaction with oriLyt. The findings demonstrate a functional role of replication proteins in stabilizing the association of ZEBRA with viral DNA. Enhanced binding of ZEBRA to oriLyt is crucial for lytic viral DNA replication.

  3. Probing the structure of glucan lyases – the lytic members of GH31 - by sequence analysis, circular dichroism and proteolysis

    DEFF Research Database (Denmark)

    Ernst, Heidi; Lo Leggio, Leila; Yu, Shukun

    2005-01-01

    Glucan lyase (GL) is a polysaccharide lyase with unique characteristics. It is involved in an alternative pathway for the degradation of alpha-glucans, the anhydrofructose pathway. Sequence similarity suggests that this lytic enzyme belongs to glycoside hydrolase family 31, for which until very r...

  4. Isolation and characterization of lytic vibriophage against Vibrio cholerae O1 from environmental water samples in Kelantan, Malaysia.

    Science.gov (United States)

    Al-Fendi, Ali; Shueb, Rafidah Hanim; Ravichandran, Manickam; Yean, Chan Yean

    2014-10-01

    Water samples from a variety of sources in Kelantan, Malaysia (lakes, ponds, rivers, ditches, fish farms, and sewage) were screened for the presence of bacteriophages infecting Vibrio cholerae. Ten strains of V. cholerae that appeared to be free of inducible prophages were used as the host strains. Eleven bacteriophage isolates were obtained by plaque assay, three of which were lytic and further characterized. The morphologies of the three lytic phages were similar with each having an icosahedral head (ca. 50-60 nm in diameter), a neck, and a sheathed tail (ca. 90-100 nm in length) characteristic of the family Myoviridae. The genomes of the lytic phages were indistinguishable in length (ca. 33.5 kb), nuclease sensitivity (digestible with DNase I, but not RNase A or S1 nuclease), and restriction enzyme sensitivity (identical banding patterns with HindIII, no digestion with seven other enzymes). Testing for infection against 46 strains of V. cholerae and 16 other species of enteric bacteria revealed that all three isolates had a narrow host range and were only capable of infecting V. cholerae O1 El Tor Inaba. The similar morphologies, indistinguishable genome characteristics, and identical host ranges of these lytic isolates suggests that they represent one phage, or several very closely related phages, present in different water sources. These isolates are good candidates for further bio-phage-control studies. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. pH值对3个根霉菌株产酶活性的影响%Enzyme-producing Abilities of Three Rhizopus Strains at Different pH Levels

    Institute of Scientific and Technical Information of China (English)

    田国政; 孙东发; 汪兴平

    2011-01-01

    The pH reaction conditions for enzyme-producing of three Rhizopus of ERh1123,ERh3421 and ERh5131,which was cultivated in culture medium with different pH value,and the activeness level of saccharified enzyme,liquefied enzyme and protease achived from aboved culture medium have been respectively measured in reactions with certain substrates,and analysed the influence of enzyme-producing by pH value.The study shows that,at optimal culture medium of pH value of 4.6~5.2,the activeness of saccharified enzymes produced by above strains can be reached at level of 1.41×102~1.59×102U/g,and liquefied enzymes 0.69×103~2.21×103U/g;and for protease the activeness can reach 1.98×103U/g ~2.58×102 U/g in culture medium with 5.8 of pH value;in reaction with certain substrates,the optimal level of pH value for saccharified enzyme was 4.6,protease 5.8,liquefied enzyme 5.2~5.8,and the activeness of enzyme of the former two,in contrast to that at condition of enzyme-producing,can be respectively improved to 1.52×102~3.21×102U/g and 2.56×102~2.97×102U/g,but no change for liquefied enzyme.Generally,there exists considerable improving for enzyme activeness levels by pH value of culture medium and of reaction liquied with substrates.%在不同的pH值培养基中培养ERh1123、ERh3421、ERh5131 3个根霉菌株,研究其产酶的pH条件,同时将得到的酶液在不同的pH值条件下与一定的底物反应,分别测定了糖化酶、液化酶、蛋白酶活性,研究了pH条件对产酶活性的影响。结果表明:菌株产糖化酶、液化酶的适宜pH为4.6~5.2,在此条件下,糖化酶的活性为1.41×102~1.59×102U/g,液化酶的活性为0.69×103~2.21×103U/g,菌株产蛋白酶的适宜pH为5.8,其活性为1.98×103U/g~2.58×102U/g;反应时糖化酶适宜的pH为4.6,蛋白酶适宜的pH为5.8,液化酶适宜的pH为5.2-5.8,反应时酶的活性与产酶条件下相比,前两种酶的活性可分别提高到1.52×102~3.21×102U/g,2.56

  6. "Lytic" lesions in autologous bone grafts: demonstration of medullary air pockets on post mortem computed tomography.

    Science.gov (United States)

    Rotman, A; Hamilton, K; O'Donnell, C

    2007-12-01

    Donor bone grafts are an important aspect of orthopaedic surgery. The use of plain film as a pathological screening tool before donor bone dispatch has revealed "lytic" lesions in proximal humeri. Donor demographics did not support the diagnosis of myeloma and subsequent computed tomography (CT) scans of these bones identified the lesions as air, not pathology. In total, 27 long bones were scanned and 100% (27/27 cases) exhibited air within the trabecular bone. Three distinct patterns were found: ovoid, linear/branching, and broad channel. A longitudinal course of CT scans was performed to identify at which stage air appeared within the bone. Pre-retrieval, preprocessing, and postprocessing scans revealed that air originated between the retrieval and preprocessing stages of donor bone preparation. There may be multiple aetiology of this phenomenon, including bone retrieval and natural decomposition.

  7. Multiple Lytic Origins of Replication Are Required for Optimal Gammaherpesvirus Fitness In Vitro and In Vivo.

    Directory of Open Access Journals (Sweden)

    Christine Sattler

    2016-03-01

    Full Text Available An unresolved question in herpesvirus biology is why some herpesviruses contain more than one lytic origin of replication (oriLyt. Using murine gammaherpesvirus 68 (MHV-68 as model virus containing two oriLyts, we demonstrate that loss of either of the two oriLyts was well tolerated in some situations but not in others both in vitro and in vivo. This was related to the cell type, the organ or the route of inoculation. Depending on the cell type, different cellular proteins, for example Hexim1 and Rbbp4, were found to be associated with oriLyt DNA. Overexpression or downregulation of these proteins differentially affected the growth of mutants lacking either the left or the right oriLyt. Thus, multiple oriLyts are required to ensure optimal fitness in different cell types and tissues.

  8. Lytic polysaccharide monooxygenases: a crystallographer's view on a new class of biomass-degrading enzymes

    Directory of Open Access Journals (Sweden)

    Kristian E. H. Frandsen

    2016-11-01

    Full Text Available Lytic polysaccharide monooxygenases (LPMOs are a new class of microbial copper enzymes involved in the degradation of recalcitrant polysaccharides. They have only been discovered and characterized in the last 5–10 years and have stimulated strong interest both in biotechnology and in bioinorganic chemistry. In biotechnology, the hope is that these enzymes will finally help to make enzymatic biomass conversion, especially of lignocellulosic plant waste, economically attractive. Here, the role of LPMOs is likely to be in attacking bonds that are not accessible to other enzymes. LPMOs have attracted enormous interest since their discovery. The emphasis in this review is on the past and present contribution of crystallographic studies as a guide to functional understanding, with a final look towards the future.

  9. In vitro management of hospital Pseudomonas aeruginosa biofilm using indigenous T7-like lytic phage.

    Science.gov (United States)

    Ahiwale, Sangeeta; Tamboli, Nilofer; Thorat, Kiran; Kulkarni, Rajendra; Ackermann, Hans; Kapadnis, Balasaheb

    2011-02-01

    Pseudomonas aeruginosa, a human pathogen capable of forming biofilm and contaminating medical settings, is responsible for 65% mortality in the hospitals all over the world. This study was undertaken to isolate lytic phages against biofilm forming Ps. aeruginosa hospital isolates and to use them for in vitro management of biofilms in the microtiter plate. Multidrug resistant strains of Ps. aeruginosa were isolated from the hospital environment in and around Pimpri-Chinchwad, Maharashtra by standard microbiological methods. Lytic phages against these strains were isolated from the Pavana river water by double agar layer plaque assay method. A wide host range phage bacterial virus Ps. aeruginosa phage (BVPaP-3) was selected. Electron microscopy revealed that BVPaP-3 phage is a T7-like phage and is a relative of phage species gh-1. A phage at MOI-0.001 could prevent biofilm formation by Ps. aeruginosa hospital strain-6(HS6) on the pegs within 24 h. It could also disperse pre-formed biofilms of all hospital isolates (HS1-HS6) on the pegs within 24 h. Dispersion of biofilm was studied by monitoring log percent reduction in cfu and log percent increase in pfu of respective bacterium and phage on the peg as well as in the well. Scanning electron microscopy confirmed that phage BVPaP-3 indeed causes biofilm reduction and bacterial cell killing. Laboratory studies prove that BVPaP-3 is a highly efficient phage in preventing and dispersing biofilms of Ps. aeruginosa. Phage BVPaP-3 can be used as biological disinfectant to control biofilm problem in medical devices.

  10. The FIKK kinase of Toxoplasma gondii is not essential for the parasite's lytic cycle.

    Science.gov (United States)

    Skariah, S; Walwyn, O; Engelberg, K; Gubbels, M-J; Gaylets, C; Kim, N; Lynch, B; Sultan, A; Mordue, D G

    2016-05-01

    FIKK kinases are a novel family of kinases unique to the Apicomplexa. While most apicomplexans encode a single FIKK kinase, Plasmodium falciparum expresses 21 and piroplasms do not encode a FIKK kinase. FIKK kinases share a conserved C-terminal catalytic domain, but the N-terminal region is highly variable and contains no known functional domains. To date, FIKK kinases have been primarily studied in P. falciparum and Plasmodium berghei. Those that have been studied are exported from the parasite and associate with diverse locations in the infected erythrocyte cytosol or membrane. Deletion of individual P. falciparum FIKK kinases indicates that they may play a role in modification of the infected erythrocyte. The current study characterises the single FIKK gene in Toxoplasma gondii to evaluate the importance of the FIKK kinase in an apicomplexan that has a single FIKK kinase. The TgFIKK gene encoded a protein of approximately 280kDa. Endogenous tagging of the FIKK protein with Yellow Fluorescent Protein showed that the FIKK protein exclusively localised to the posterior end of tachyzoites. A Yellow Fluorescent Protein-tagged FIKK and a Ty-tagged FIKK both co-localised with T. gondii membrane occupation and recognition nexus protein to the basal complex and were localised apical to inner membrane complex protein-5 and Centrin2. Deletion of TgFIKK, surprisingly, had no detectable effect on the parasite's lytic cycle in vitro in human fibroblast cells or in acute virulence in vivo. Thus, our results clearly show that while the FIKK kinase is expressed in tachyzoites, it is not essential for the lytic cycle of T. gondii. Copyright © 2016 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

  11. Broad-range lytic bacteriophages that kill Staphylococcus aureus local field strains.

    Science.gov (United States)

    Abatángelo, Virginia; Peressutti Bacci, Natalia; Boncompain, Carina A; Amadio, Ariel A; Carrasco, Soledad; Suárez, Cristian A; Morbidoni, Héctor R

    2017-01-01

    Staphylococcus aureus is a very successful opportunistic pathogen capable of causing a variety of diseases ranging from mild skin infections to life-threatening sepsis, meningitis and pneumonia. Its ability to display numerous virulence mechanisms matches its skill to display resistance to several antibiotics, including β-lactams, underscoring the fact that new anti-S. aureus drugs are urgently required. In this scenario, the utilization of lytic bacteriophages that kill bacteria in a genus -or even species- specific way, has become an attractive field of study. In this report, we describe the isolation, characterization and sequencing of phages capable of killing S. aureus including methicillin resistant (MRSA) and multi-drug resistant S. aureus local strains from environmental, animal and human origin. Genome sequencing and bio-informatics analysis showed the absence of genes encoding virulence factors, toxins or antibiotic resistance determinants. Of note, there was a high similarity between our set of phages to others described in the literature such as phage K. Considering that reported phages were obtained in different continents, it seems plausible that there is a commonality of genetic features that are needed for optimum, broad host range anti-staphylococcal activity of these related phages. Importantly, the high activity and broad host range of one of our phages underscores its promising value to control the presence of S. aureus in fomites, industry and hospital environments and eventually on animal and human skin. The development of a cocktail of the reported lytic phages active against S. aureus-currently under way- is thus, a sensible strategy against this pathogen.

  12. Revisiting the Cellulosimicrobium cellulans yeast-lytic β-1,3-glucanases toolbox: A review

    Directory of Open Access Journals (Sweden)

    Ferrer Pau

    2006-03-01

    Full Text Available Abstract Cellulosimicrobium cellulans (also known with the synonyms Cellulomonas cellulans, Oerskovia xanthineolytica, and Arthrobacter luteus is an actinomycete that excretes yeast cell wall lytic enzyme complexes containing endo-β-1,3-glucanases [EC 3.2.1.39 and 3.2.1.6] as key constituents. Three genes encoding endo-β-1,3-glucanases from two C. cellulans strains have been cloned and characterised over the past years. The βglII and βglIIA genes from strain DSM 10297 (also known as O. xanthineolytica LL G109 encoded proteins of 40.8 and 28.6 kDa, respectively, whereas the β-1,3-glucanase gene from strain ATCC 21606 (also known as A. luteus 73–14 encoded a 54.5 kDa protein. Alignment of their deduced amino acid sequences reveal that βglII and βglIIA have catalytic domains assigned to family 16 of glycosyl hydrolases, whereas the catalytic domain from the 54.5 kDa glucanase belongs to family 64. Notably, both βglII and the 54.5 kDa β-1,3-glucanase are multidomain proteins, having a lectin-like C-terminal domain that has been assigned to family 13 of carbohydrate binding modules, and that confers to β-1,3-glucanases the ability to lyse viable yeast cells. Furthermore, βglII may also undergo posttranslational proteolytic processing of its C-terminal domain, resulting in a truncated enzyme retaining its glucanase activity but with very low yeast-lytic activity. In this review, the diversity in terms of structural and functional characteristics of the C. cellulans β-1,3-glucanases has been compiled and compared.

  13. Lytic Characteristics and Identification of Two Alga-lysing Bacterial Strains

    Institute of Scientific and Technical Information of China (English)

    PEI Haiyan; HU Wenrong

    2006-01-01

    All previously reported bacterial species which are capable of lysing harmful algae have been isolated from coastal environments in which harmful algae blooms have occurred. Due to the low concentration of alga-lysing bacteria in an algal bloom, it is difficult to isolate the alga-lysing bacteria by existing methods. In this paper, two algae-lysing bacterial strains,P01 and P03, have been isolated from a biosystem immobilized on a sponge that was highly effective in removing algae and microcystins. Their lysing modes and effects on Microcystis aeruginosa have been studied. The results show that the degradation processes of these two strains for M. aeruginosa accorded with a first-order reaction model when the chlorophylla concentration was in the range from 0 to 1000 μg L-1. The degradation rate constants were 0.106 7, 0.127 4 and 0.279 2 for P01and0.0683, 0.0744 and 0.02897 for P03, when the bacterial densities were 8.6 × 105, 8.6 × 106 and 8.6 × 107cells mL 1, respectively. Moreover, the two bacterial strains had favourable lytic effects not only on M. aeruginosa, but also on Chlorella and Scene-desmus. Their lytic effect on M. aeruginosa did not require physical cell to cell contact, but proceeded by the production of an extracellular product. The bacterial strains were identified as Bacillus species by PCR amplification of the 16S rRNA gene, BLAST analysis, and comparison with sequences in the GenBank nucleotide database.

  14. Structure of the Bacteriophage [phi]KZ Lytic Transglycosylase gp144

    Energy Technology Data Exchange (ETDEWEB)

    Fokine, Andrei; Miroshnikov, Konstantin A.; Shneider, Mikhail M.; Mesyanzhinov, Vadim V.; Rossmann, Michael G. (SOIBC); (Purdue)

    2008-04-02

    Lytic transglycosylases are enzymes that act on the peptidoglycan of bacterial cell walls. They cleave the glycosidic linkage between N-acetylmuramoyl and N-acetylglucosaminyl residues with the concomitant formation of a 1,6-anhydromuramoyl product. The x-ray structure of the lytic transglycosylase gp144 from the Pseudomonas bacteriophage {phi}KZ has been determined to 2.5-{angstrom} resolution. This protein is probably employed by the bacteriophage in the late stage of the virus reproduction cycle to destroy the bacterial cell wall to release the phage progeny. {phi}KZ gp144 is a 260-residue {alpha}-helical protein composed of a 70-residue N-terminal cell wall-binding domain and a C-terminal catalytic domain. The fold of the N-terminal domain is similar to the peptidoglycan-binding domain from Streptomyces albus G d-Ala-d-Ala carboxypeptidase and to the N-terminal prodomain of human metalloproteinases that act on extracellular matrices. The C-terminal catalytic domain of gp144 has a structural similarity to the catalytic domain of the transglycosylase Slt70 from Escherichia coli and to lysozymes. The gp144 catalytic domain has an elongated groove that can bind at least five sugar residues at sites A-E. As in other lysozymes, the peptidoglycan cleavage (catalyzed by Glu{sup 115} in gp144) occurs between sugar-binding subsites D and E. The x-ray structure of the {phi}KZ transglycosylase complexed with the chitotetraose (N-acetylglucosamine){sub 4} has been determined to 2.6-{angstrom} resolution. The N-acetylglucosamine residues of the chitotetraose bind in sites A-D.

  15. Delta-9 tetrahydrocannabinol (THC inhibits lytic replication of gamma oncogenic herpesviruses in vitro

    Directory of Open Access Journals (Sweden)

    Friedman Herman

    2004-09-01

    Full Text Available Abstract Background The major psychoactive cannabinoid compound of marijuana, delta-9 tetrahydrocannabinol (THC, has been shown to modulate immune responses and lymphocyte function. After primary infection the viral DNA genome of gamma herpesviruses persists in lymphoid cell nuclei in a latent episomal circular form. In response to extracellular signals, the latent virus can be activated, which leads to production of infectious virus progeny. Therefore, we evaluated the potential effects of THC on gamma herpesvirus replication. Methods Tissue cultures infected with various gamma herpesviruses were cultured in the presence of increasing concentrations of THC and the amount of viral DNA or infectious virus yield was compared to those of control cultures. The effect of THC on Kaposi's Sarcoma Associated Herpesvirus (KSHV and Epstein-Barr virus (EBV replication was measured by the Gardella method and replication of herpesvirus saimiri (HVS of monkeys, murine gamma herpesvirus 68 (MHV 68, and herpes simplex type 1 (HSV-1 was measured by yield reduction assays. Inhibition of the immediate early ORF 50 gene promoter activity was measured by the dual luciferase method. Results Micromolar concentrations of THC inhibit KSHV and EBV reactivation in virus infected/immortalized B cells. THC also strongly inhibits lytic replication of MHV 68 and HVS in vitro. Importantly, concentrations of THC that inhibit virus replication of gamma herpesviruses have no effect on cell growth or HSV-1 replication, indicating selectivity. THC was shown to selectively inhibit the immediate early ORF 50 gene promoter of KSHV and MHV 68. Conclusions THC specifically targets viral and/or cellular mechanisms required for replication and possibly shared by these gamma herpesviruses, and the endocannabinoid system is possibly involved in regulating gamma herpesvirus latency and lytic replication. The immediate early gene ORF 50 promoter activity was specifically inhibited by THC

  16. Remodelling of cortical actin where lytic granules dock at natural killer cell immune synapses revealed by super-resolution microscopy.

    Directory of Open Access Journals (Sweden)

    Alice C N Brown

    2011-09-01

    Full Text Available Natural Killer (NK cells are innate immune cells that secrete lytic granules to directly kill virus-infected or transformed cells across an immune synapse. However, a major gap in understanding this process is in establishing how lytic granules pass through the mesh of cortical actin known to underlie the NK cell membrane. Research has been hampered by the resolution of conventional light microscopy, which is too low to resolve cortical actin during lytic granule secretion. Here we use two high-resolution imaging techniques to probe the synaptic organisation of NK cell receptors and filamentous (F-actin. A combination of optical tweezers and live cell confocal microscopy reveals that microclusters of NKG2D assemble into a ring-shaped structure at the centre of intercellular synapses, where Vav1 and Grb2 also accumulate. Within this ring-shaped organisation of NK cell proteins, lytic granules accumulate for secretion. Using 3D-structured illumination microscopy (3D-SIM to gain super-resolution of ~100 nm, cortical actin was detected in a central region of the NK cell synapse irrespective of whether activating or inhibitory signals dominate. Strikingly, the periodicity of the cortical actin mesh increased in specific domains at the synapse when the NK cell was activated. Two-colour super-resolution imaging revealed that lytic granules docked precisely in these domains which were also proximal to where the microtubule-organising centre (MTOC polarised. Together, these data demonstrate that remodelling of the cortical actin mesh occurs at the central region of the cytolytic NK cell immune synapse. This is likely to occur for other types of cell secretion and also emphasises the importance of emerging super-resolution imaging technology for revealing new biology.

  17. Remodelling of cortical actin where lytic granules dock at natural killer cell immune synapses revealed by super-resolution microscopy.

    Science.gov (United States)

    Brown, Alice C N; Oddos, Stephane; Dobbie, Ian M; Alakoskela, Juha-Matti; Parton, Richard M; Eissmann, Philipp; Neil, Mark A A; Dunsby, Christopher; French, Paul M W; Davis, Ilan; Davis, Daniel M

    2011-09-01

    Natural Killer (NK) cells are innate immune cells that secrete lytic granules to directly kill virus-infected or transformed cells across an immune synapse. However, a major gap in understanding this process is in establishing how lytic granules pass through the mesh of cortical actin known to underlie the NK cell membrane. Research has been hampered by the resolution of conventional light microscopy, which is too low to resolve cortical actin during lytic granule secretion. Here we use two high-resolution imaging techniques to probe the synaptic organisation of NK cell receptors and filamentous (F)-actin. A combination of optical tweezers and live cell confocal microscopy reveals that microclusters of NKG2D assemble into a ring-shaped structure at the centre of intercellular synapses, where Vav1 and Grb2 also accumulate. Within this ring-shaped organisation of NK cell proteins, lytic granules accumulate for secretion. Using 3D-structured illumination microscopy (3D-SIM) to gain super-resolution of ~100 nm, cortical actin was detected in a central region of the NK cell synapse irrespective of whether activating or inhibitory signals dominate. Strikingly, the periodicity of the cortical actin mesh increased in specific domains at the synapse when the NK cell was activated. Two-colour super-resolution imaging revealed that lytic granules docked precisely in these domains which were also proximal to where the microtubule-organising centre (MTOC) polarised. Together, these data demonstrate that remodelling of the cortical actin mesh occurs at the central region of the cytolytic NK cell immune synapse. This is likely to occur for other types of cell secretion and also emphasises the importance of emerging super-resolution imaging technology for revealing new biology.

  18. Protease expression by microorganisms and its relevance to crucial physiological/pathological events

    Institute of Scientific and Technical Information of China (English)

    AndréLuis; Souza; dos; Santos

    2011-01-01

    The treatment of infections caused by fungi and trypanosomatids is difficult due to the eukaryotic nature of these microbial cells,which are similar in several biochemical and genetic aspects to host cells.Aggravating this scenario,very few antifungal and anti-trypanosomatidal agents are in clinical use and,therefore,therapy is limited by drug safety considerations and their narrow spectrum of activity,efficacy and resistance. The search for new bioactive agents against fungi and trypanosomatids has been expanded because progress in biochemistry and molecular biology has led to a better understanding of important and essential pathways in these microorganisms including nutrition,growth, proliferation,signaling,differentiation and death.In this context,proteolytic enzymes produced by these eukaryotic microorganisms are appointed and,in some cases,proven to be excellent targets for searching novel natural and/or synthetic pharmacological compounds,in order to cure or prevent invasive fungal/trypanosomatid diseases.With this task in mind,our research group and others have focused on aspartic-type proteases,since the activity of this class of hydrolytic enzymes is directly implicated in several facets of basic biological processes of both fungal and trypanosomatid cells as well as due to the participation in numerous events of interaction between these microorganisms and host structures.In the present paper,a concise revision of the beneficial effects of aspartic protease inhibitors,with emphasis on the aspartic protease inhibitors used in the anti-human immunodeficiency virus therapy,will be presented and discussed using our experience with the following microbial models:the yeast Candida albicans,the filamentous fungus Fonsecaea pedrosoi and the protozoan trypanosomatid Leishmania amazonensis.

  19. Microorganisms interacting in a bio filter

    Energy Technology Data Exchange (ETDEWEB)

    Barba-Avila, M. D.; Flores-Tene, F. J.; Moreno-Terrazas, R.; Ramirez-Lopez, E. M.

    2009-07-01

    Biofilm microorganisms developed on a bio filter support media allow the metabolism of volatile organic compounds (VOCs) to carbon dioxide and water. VOCs are present in polluted gaseous streams for varied industrial activities. The main objective of this study was to identify the microorganisms present in the biofilm developed on a bio filter support media using molecular biology techniques. (Author)

  20. Microorganisms Resistant to Free-Living Amoebae

    OpenAIRE

    Greub, Gilbert; Raoult, Didier

    2004-01-01

    Free-living amoebae feed on bacteria, fungi, and algae. However, some microorganisms have evolved to become resistant to these protists. These amoeba-resistant microorganisms include established pathogens, such as Cryptococcus neoformans, Legionella spp., Chlamydophila pneumoniae, Mycobacterium avium, Listeria monocytogenes, Pseudomonas aeruginosa, and Francisella tularensis, and emerging pathogens, such as Bosea spp., Simkania negevensis, Parachlamydia acanthamoebae, and Legionella-like amoe...

  1. Spoilage microorganisms in milk and dairy products

    Directory of Open Access Journals (Sweden)

    Andrea Skelin

    2007-12-01

    Full Text Available Spoilage microorganisms cause changes of primary characteristics and properties of milk and dairy products. The product defects depends on the specific species and number of microorganisms involved in pre- and post- technological processing. Most often, these changes are related to single undesirable sensory characteristic, smell, flavour or conistency. However, in the case of heavier microbial contamination all these undesirable characteristics can occur simultaneously. Besides, even small changes caused by presence of spoilage microorganisms lead to decreased quality of milk and various dairy products. Despite of the importance for the overall quality, the control of spoilage microorganisms for dairy industry is not obligated and therefore, only a few producers control them. Therefore, the present study describes the undesirable effect of spoilage microorganisms on quality of raw, pasteurized and sterilized milk, fermented milk, butter, sour cream and cheeses with the intention to emphasize the importance and significance of their control in the dairy industry.

  2. Biofouling of marbles by oxygenic photosynthetic microorganisms.

    Science.gov (United States)

    Karaca, Zeki; Öztürk, Ayten; Çolak, Emel

    2015-08-01

    Phototrophic microorganisms disfigure the surfaces of different types of stone. Stone structure is damaged by the activity of photoautotrophic and other microorganisms. However, to date few, investigations have been undertaken into the relationship between microorganisms and the properties of different types of marble. In this study, biological activity of photoautotrophic microorganisms on three types of marble (Yatagan White, Giallo Anticato and Afyon White) was investigated under laboratory conditions over a short period of time. The three types of marble supported the growth of phototrophic microbial communities on their outer and inner layers, turning their original colour from white to a yellowish green colour. The porosity of the marble types facilitated filamentous microbial growth in the presence of water. Scanning electron microscope analysis revealed the accumulation of aggregates such as small spherical, fibrillar, calcified globular bodies on the inner surfaces of the marbles. This suggests that the microscopic characteristics of particular marble types may stimulate the growth of certain types of microorganisms.

  3. FUNCTIONAL POLYHYDROXYALKANOATES SYNTHESIZED BY MICROORGANISMS

    Institute of Scientific and Technical Information of China (English)

    Guo-qiang Chen; Qiong Wu; Kai Zhao; Peter H.Yu

    2000-01-01

    Many bacteria have been found to synthesize a family of polyesters termed polyhydroxyalkanoate, abbreviated as PHA. Some interesting physical properties of PHAs such as piezoelectricity, non-linear optical activity, biocompatibility and biodegradability offer promising applications in areas such as degradable packaging, tissue engineering and drug delivery.Over 90 PHAs with various structure variations have been reported and the number is still increasing. The mechanical property of PHAs changes from brittle to flexible to elastic, depending on the side-chainlength of PHA. Many attempts have been made to produce PHAs as biodegradable plastics using various microorganisms obtained from screening natural environments, genetic engineering and mutation. Due to the high production cost, PHAs still can not compete with the nondegradable plastics, such as polyethylene and polypropylene. Various processes have been developed using low cost raw materials for fermentation and an inorganic extraction process for PHA purification. However, a super PHA production strain may play the most critical role for any large-scale PHA production. Our recent study showed that PHA synthesis is a common phenomenon among bacteria inhabiting various locations, especially oil-contaminated soils. This is very important for finding a suitable bacterial strain for PHA production. In fact, PHA production strains capable of rapid growth and rapid PHA synthesis on cheap molasses substrate have been found on molasses contaminated soils. A combination of novel properties and lower cost will allow easier commercialization of PHA for many applications.

  4. Systems biology of industrial microorganisms.

    Science.gov (United States)

    Papini, Marta; Salazar, Margarita; Nielsen, Jens

    2010-01-01

    The field of industrial biotechnology is expanding rapidly as the chemical industry is looking towards more sustainable production of chemicals that can be used as fuels or building blocks for production of solvents and materials. In connection with the development of sustainable bioprocesses, it is a major challenge to design and develop efficient cell factories that can ensure cost efficient conversion of the raw material into the chemical of interest. This is achieved through metabolic engineering, where the metabolism of the cell factory is engineered such that there is an efficient conversion of sugars, the typical raw materials in the fermentation industry, into the desired product. However, engineering of cellular metabolism is often challenging due to the complex regulation that has evolved in connection with adaptation of the different microorganisms to their ecological niches. In order to map these regulatory structures and further de-regulate them, as well as identify ingenious metabolic engineering strategies that full-fill mass balance constraints, tools from systems biology can be applied. This involves both high-throughput analysis tools like transcriptome, proteome and metabolome analysis, as well as the use of mathematical modeling to simulate the phenotypes resulting from the different metabolic engineering strategies. It is in fact expected that systems biology may substantially improve the process of cell factory development, and we therefore propose the term Industrial Systems Biology for how systems biology will enhance the development of industrial biotechnology for sustainable chemical production.

  5. [Genome editing of industrial microorganism].

    Science.gov (United States)

    Zhu, Linjiang; Li, Qi

    2015-03-01

    Genome editing is defined as highly-effective and precise modification of cellular genome in a large scale. In recent years, such genome-editing methods have been rapidly developed in the field of industrial strain improvement. The quickly-updating methods thoroughly change the old mode of inefficient genetic modification, which is "one modification, one selection marker, and one target site". Highly-effective modification mode in genome editing have been developed including simultaneous modification of multiplex genes, highly-effective insertion, replacement, and deletion of target genes in the genome scale, cut-paste of a large DNA fragment. These new tools for microbial genome editing will certainly be applied widely, and increase the efficiency of industrial strain improvement, and promote the revolution of traditional fermentation industry and rapid development of novel industrial biotechnology like production of biofuel and biomaterial. The technological principle of these genome-editing methods and their applications were summarized in this review, which can benefit engineering and construction of industrial microorganism.

  6. Systems Biology of Industrial Microorganisms

    Science.gov (United States)

    Papini, Marta; Salazar, Margarita; Nielsen, Jens

    The field of industrial biotechnology is expanding rapidly as the chemical industry is looking towards more sustainable production of chemicals that can be used as fuels or building blocks for production of solvents and materials. In connection with the development of sustainable bioprocesses, it is a major challenge to design and develop efficient cell factories that can ensure cost efficient conversion of the raw material into the chemical of interest. This is achieved through metabolic engineering, where the metabolism of the cell factory is engineered such that there is an efficient conversion of sugars, the typical raw materials in the fermentation industry, into the desired product. However, engineering of cellular metabolism is often challenging due to the complex regulation that has evolved in connection with adaptation of the different microorganisms to their ecological niches. In order to map these regulatory structures and further de-regulate them, as well as identify ingenious metabolic engineering strategies that full-fill mass balance constraints, tools from systems biology can be applied. This involves both high-throughput analysis tools like transcriptome, proteome and metabolome analysis, as well as the use of mathematical modeling to simulate the phenotypes resulting from the different metabolic engineering strategies. It is in fact expected that systems biology may substantially improve the process of cell factory development, and we therefore propose the term Industrial Systems Biology for how systems biology will enhance the development of industrial biotechnology for sustainable chemical production.

  7. DNA Damage Signaling Is Induced in the Absence of Epstein-Barr Virus (EBV) Lytic DNA Replication and in Response to Expression of ZEBRA.

    Science.gov (United States)

    Wang'ondu, Ruth; Teal, Stuart; Park, Richard; Heston, Lee; Delecluse, Henri; Miller, George

    2015-01-01

    Epstein Barr virus (EBV), like other oncogenic viruses, modulates the activity of cellular DNA damage responses (DDR) during its life cycle. Our aim was to characterize the role of early lytic proteins and viral lytic DNA replication in activation of DNA damage signaling during the EBV lytic cycle. Our data challenge the prevalent hypothesis that activation of DDR pathways during the EBV lytic cycle occurs solely in response to large amounts of exogenous double stranded DNA products generated during lytic viral DNA replication. In immunofluorescence or immunoblot assays, DDR activation markers, specifically phosphorylated ATM (pATM), H2AX (γH2AX), or 53BP1 (p53BP1), were induced in the presence or absence of viral DNA amplification or replication compartments during the EBV lytic cycle. In assays with an ATM inhibitor and DNA damaging reagents in Burkitt lymphoma cell lines, γH2AX induction was necessary for optimal expression of early EBV genes, but not sufficient for lytic reactivation. Studies in lytically reactivated EBV-positive cells in which early EBV proteins, BGLF4, BGLF5, or BALF2, were not expressed showed that these proteins were not necessary for DDR activation during the EBV lytic cycle. Expression of ZEBRA, a viral protein that is necessary for EBV entry into the lytic phase, induced pATM foci and γH2AX independent of other EBV gene products. ZEBRA mutants deficient in DNA binding, Z(R183E) and Z(S186E), did not induce foci of pATM. ZEBRA co-localized with HP1β, a heterochromatin associated protein involved in DNA damage signaling. We propose a model of DDR activation during the EBV lytic cycle in which ZEBRA induces ATM kinase phosphorylation, in a DNA binding dependent manner, to modulate gene expression. ATM and H2AX phosphorylation induced prior to EBV replication may be critical for creating a microenvironment of viral and cellular gene expression that enables lytic cycle progression.

  8. Activation and Repression of Epstein-Barr Virus and Kaposi's Sarcoma-Associated Herpesvirus Lytic Cycles by Short- and Medium-Chain Fatty Acids

    Science.gov (United States)

    Gorres, Kelly L.; Daigle, Derek; Mohanram, Sudharshan

    2014-01-01

    ABSTRACT The lytic cycles of Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) are induced in cell culture by sodium butyrate (NaB), a short-chain fatty acid (SCFA) histone deacetylase (HDAC) inhibitor. Valproic acid (VPA), another SCFA and an HDAC inhibitor, induces the lytic cycle of KSHV but blocks EBV lytic reactivation. To explore the hypothesis that structural differences between NaB and VPA account for their functional effects on the two related viruses, we investigated the capacity of 16 structurally related short- and medium-chain fatty acids to promote or prevent lytic cycle reactivation. SCFAs differentially affected EBV and KSHV reactivation. KSHV was reactivated by all SCFAs that are HDAC inhibitors, including phenylbutyrate. However, several fatty acid HDAC inhibitors, such as isobutyrate and phenylbutyrate, did not reactivate EBV. Reactivation of KSHV lytic transcripts could not be blocked completely by any fatty acid tested. In contrast, several medium-chain fatty acids inhibited lytic activation of EBV. Fatty acids that blocked EBV reactivation were more lipophilic than those that activated EBV. VPA blocked activation of the BZLF1 promoter by NaB but did not block the transcriptional function of ZEBRA. VPA also blocked activation of the DNA damage response that accompanies EBV lytic cycle activation. Properties of SCFAs in addition to their effects on chromatin are likely to explain activation or repression of EBV. We concluded that fatty acids stimulate the two related human gammaherpesviruses to enter the lytic cycle through different pathways. IMPORTANCE Lytic reactivation of EBV and KSHV is needed for persistence of these viruses and plays a role in carcinogenesis. Our direct comparison highlights the mechanistic differences in lytic reactivation between related human oncogenic gammaherpesviruses. Our findings have therapeutic implications, as fatty acids are found in the diet and produced by the human microbiota

  9. 刺参肠道潜在产酶益生菌的筛选和鉴定%Screening and identification of potential enzyme producing probiotics from gut of sea cucumber Apostichopus japonicus

    Institute of Scientific and Technical Information of China (English)

    杨志平; 孙飞雪; 刘志明; 张磊; 曹为; 马悦欣

    2013-01-01

    从健康刺参Apostichopus japonicus(体质量为10~30 g)肠道中分离出50株细菌,以点种法在选择培养基上对菌株产淀粉酶、蛋白酶、脂肪酶和纤维素酶的能力进行测试,筛选出产3种酶以上的细菌13株,并定量测定了其中9株菌的淀粉酶和蛋白酶活力.依据产酶能力选6株细菌进行溶血试验.结果表明:6株菌均不产生溶血素,不具有潜在的致病性,选3株产酶细菌BC26、BC228、BC232进行毒力测试,经一个月观察证实,无论给刺参腹腔注射细胞浓度为107 cfu/mL的菌悬液,还是投喂含细菌浓度为109 cfu/g的干饲料,刺参都是安全的;对细菌16S rDNA序列同源性的分析表明,BC26、BC228、BC232菌株分别与芽孢杆菌Bacillus sp.FA132、假交替单胞菌Pseudoalteromonas sp.NBRC102016和塔斯马尼亚弧菌Vibrio tasmaniensis 04102的相似性均为99%.%Fifty bacterial strains were isolated from gut of healthy sea cucumber Apostichopus japonicus with body weight of 10-30 g, whose extracellular amylase, protease, lipase and cellulase activities were detected using selective media by point inoculation method. Thirteen bacterial strains producing 3 enzymes were screened, nine strains of which were further quantitatively assayed for amylase and protease activities. Hemolysis was tested in six bacterial strains selected depending on the extracellular enzyme producing ability. The results showed that the six bacterial strains did not secreted hemolysin, without potential pathogenicity. The toxicity test revealed that three enzyme producing bacterial strains,BC26, BC228 and BC232, were found to be safe for the sea cucumber which were challenged by intra-peritoneal injection of 0.1 mL cell suspension of the three bacterial strains at concentration of 107 cfu/mL, and which were fed the diet containing the three bacterial cells at 109 cfu/g once daily for one month. Similarity analysis of 16S rDNA sequences indicated that the bacterial strain BC26 had

  10. 1株纤溶酶菌株的筛选鉴定及提高产酶量的方法研究%Screening and Identification of a Fibrinolytic Enzyme Producing Strain and Research on Increasing its Enzyme Yield

    Institute of Scientific and Technical Information of China (English)

    王海曼; 宋刚; 柴洋洋; 平文祥; 葛菁萍

    2011-01-01

    从齐齐哈尔市拜泉县的自酿农家豆酱制品中分离筛选出1株产纤溶酶菌株HDBF-DJ3,对其进行菌体、菌落、生理生化特征分析,并结合16S rDNA序列分析结果,鉴定其为枯草芽孢杆菌.经亚硝基胍诱变筛选得到突变株HDBF-DJ3N7,其纤溶酶活力为368.78 IU/mL,是出发菌株的2.1倍.对菌株HDBF-DJ3N7进行连续10代的培养,结果表明该突变株的高产纤溶酶特性能够稳定遗传.该菌株有望应用到生产领域.%A flbrinolytic enzyme producing strain named HDBF-DJ3 was isolated from soy-bean paste which was sampled from Baiquan county of Qiqihar district. It was initially identified as Bacillus subtilis by testing its morphological, physiological and biochemical characteristics as well as 16S rDNA sequence analysis. A mutant named HDBF-DJ3N7 was obtained from HDBF-DJ3 by mutagenesis treatment of nitrosoguanidine(NTG). The fibrinolysin activity of HDBF-DJ3N7 was 368.78 U/mL, which was 2.1 times higher than that of HDBF-DJ3. It was indicated that the mutant had genetic stability on fibrinolytic enzyme production by 10 generation cultivation and it could be applied into production field.

  11. Increased CD8+ T cell response to Epstein-Barr virus lytic antigens in the active phase of multiple sclerosis.

    Directory of Open Access Journals (Sweden)

    Daniela F Angelini

    Full Text Available It has long been known that multiple sclerosis (MS is associated with an increased Epstein-Barr virus (EBV seroprevalence and high immune reactivity to EBV and that infectious mononucleosis increases MS risk. This evidence led to postulate that EBV infection plays a role in MS etiopathogenesis, although the mechanisms are debated. This study was designed to assess the prevalence and magnitude of CD8+ T-cell responses to EBV latent (EBNA-3A, LMP-2A and lytic (BZLF-1, BMLF-1 antigens in relapsing-remitting MS patients (n = 113 and healthy donors (HD (n = 43 and to investigate whether the EBV-specific CD8+ T cell response correlates with disease activity, as defined by clinical evaluation and gadolinium-enhanced magnetic resonance imaging. Using HLA class I pentamers, lytic antigen-specific CD8+ T cell responses were detected in fewer untreated inactive MS patients than in active MS patients and HD while the frequency of CD8+ T cells specific for EBV lytic and latent antigens was higher in active and inactive MS patients, respectively. In contrast, the CD8+ T cell response to cytomegalovirus did not differ between HD and MS patients, irrespective of the disease phase. Marked differences in the prevalence of EBV-specific CD8+ T cell responses were observed in patients treated with interferon-β and natalizumab, two licensed drugs for relapsing-remitting MS. Longitudinal studies revealed expansion of CD8+ T cells specific for EBV lytic antigens during active disease in untreated MS patients but not in relapse-free, natalizumab-treated patients. Analysis of post-mortem MS brain samples showed expression of the EBV lytic protein BZLF-1 and interactions between cytotoxic CD8+ T cells and EBV lytically infected plasma cells in inflammatory white matter lesions and meninges. We therefore propose that inability to control EBV infection during inactive MS could set the stage for intracerebral viral reactivation and disease relapse.

  12. Application of flow cytometry to wine microorganisms.

    Science.gov (United States)

    Longin, Cédric; Petitgonnet, Clément; Guilloux-Benatier, Michèle; Rousseaux, Sandrine; Alexandre, Hervé

    2017-04-01

    Flow cytometry (FCM) is a powerful technique allowing detection and enumeration of microbial populations in food and during food process. Thanks to the fluorescent dyes used and specific probes, FCM provides information about cell physiological state and allows enumeration of a microorganism in a mixed culture. Thus, this technique is increasingly used to quantify pathogen, spoilage microorganisms and microorganisms of interest. Since one decade, FCM applications to the wine field increase greatly to determine population and physiological state of microorganisms performing alcoholic and malolactic fermentations. Wine spoilage microorganisms were also studied. In this review we briefly describe FCM principles. Next, a deep revision concerning enumeration of wine microorganisms by FCM is presented including the fluorescent dyes used and techniques allowing a yeast and bacteria species specific enumeration. Then, the last chapter is dedicated to fluorescent dyes which are used to date in fluorescent microscopy but applicable in FCM. This chapter also describes other interesting "future" techniques which could be applied to study the wine microorganisms. Thus, this review seeks to highlight the main advantages of the flow cytometry applied to wine microbiology.

  13. Utility of lytic bacteriophage in the treatment of multidrug-resistant Pseudomonas aeruginosa septicemia in mice

    Directory of Open Access Journals (Sweden)

    Vinodkumar C

    2008-07-01

    Full Text Available Drug resistance is the major cause of increase in morbidity and mortality in neonates. One thousand six hundred forty-seven suspected septicemic neonates were subjected for microbiological analysis over a period of 5 years. Forty-two P. aeruginosa were isolated and the antibiogram revealed that 28 P. aeruginosa were resistant to almost all the common drugs used (multidrug-resistant. The emergence of antibiotic-resistant bacterial strains is one of the most critical problems of modern medicine. As a result, a novel and most effective approaches for treating infection caused by multidrug-resistant bacteria are urgently required. In this context, one intriguing approach is to use bacteriophages (viruses that kill bacteria in the treatment of infection caused by drug-resistant bacteria. In the present study, the utility of lytic bacteriophages to rescue septicemic mice with multidrug-resistant (MDR P. aeruginosa infection was evaluated. MDR P. aeruginosa was used to induce septicemia in mice by intraperitoneal (i.p. injection of 10 7 CFU. The resulting bacteremia was fatal within 48 hrs. The phage strain used in this study had lytic activity against a wide range of clinical isolates of MDR P. aeruginosa. A single i.p. injection of 3 x 10 9 PFU of the phage strain, administered 45 min after the bacterial challenge, was sufficient to rescue 100% of the animals. Even when treatment was delayed to the point where all animals were moribund, approximately 50% of them were rescued by a single injection of this phage preparation. The ability of this phage to rescue septicemic mice was demonstrated to be due to the functional capabilities of the phage and not to a nonspecific immune effect. The rescue of septicemic mice could be affected only by phage strains able to grow in vitro on the bacterial host used to infect the animals and when such strains are heat-inactivated, they lose their ability to rescue the infected mice. Multidrug-resistant bacteria have

  14. Survival of Salmonella Newport on Whole and Fresh-Cut Cucumbers Treated with Lytic Bacteriophages.

    Science.gov (United States)

    Sharma, Manan; Dashiell, Gwendolyn; Handy, Eric T; East, Cheryl; Reynnells, Russell; White, Chanelle; Nyarko, Esmond; Micallef, Shirley; Hashem, Fawzy; Millner, Patricia D

    2017-04-01

    Salmonella enterica associated with consumption of cucumbers ( Cucumis sativus ) has led to foodborne outbreaks in the United States. Whole and fresh-cut cucumbers are susceptible to S. enterica contamination during growing, harvesting, and postharvest handling. The application of lytic bacteriophages specific for S. enterica was evaluated to reduce Salmonella populations on cucumbers. Unwaxed cucumbers ('Lisboa' variety, or mini-cucumbers purchased at retail) were inoculated with Salmonella Newport (5 log CFU per cucumber) and were sprayed with 3.2 mL of phosphate-buffered saline (control) or 10 log PFU/ml of SalmoFresh, a Salmonella-specific bacteriophage preparation (phage), to deliver 4.76 × 10(7) PFU/cm(2). Cucumbers were stored at 10 or 22°C for 7 days. Inoculated mini-cucumbers were sliced with a sterile knife to investigate Salmonella transfer to mesocarp, and cut pieces were stored at 4°C for 2 days. Populations (log CFU per cucumber) of Salmonella Newport on phage-treated whole cucumbers were significantly (P cucumbers (4.27 ± 0.37) on day 0. Populations on phage-treated cucumbers stored at 10°C were 1.72 ± 0.77 and 1.56 ± 0.46, which were significantly lower than those on control-treated cucumbers (3.20 ± 0.48 and 2.33 ± 0.25) on days 1 and 4, respectively. Between days 0 and 1, populations on control-treated cucumbers stored at 10 and 22°C declined by 1.07 and 2.47 log CFU per cucumber, respectively. At 22°C, Salmonella Newport populations declined by 2.37 log CFU per cucumber between days 0 and 1. Phage application to whole cucumbers before slicing did not reduce the transfer of Salmonella Newport to fresh-cut slices. Lytic phage application may be a potential intervention to reduce Salmonella populations on whole cucumbers.

  15. A rapid quantitative activity assay shows that the Vibrio cholerae colonization factor GbpA is an active lytic polysaccharide monooxygenase

    NARCIS (Netherlands)

    Loose, Jennifer S. M.; Forsberg, Zarah; Fraaije, Marco W.; Eijsink, Vincent G. H.; Vaaje-Kolstad, Gustav

    2014-01-01

    The discovery of the copper-dependent lytic polysaccharide monooxygenases (LPMOs) has revealed new territory for chemical and biochemical analysis. These unique mononuclear copper enzymes are abundant, suggesting functional diversity beyond their established roles in the depolymerization of biomass

  16. A rapid quantitative activity assay shows that the Vibrio cholerae colonization factor GbpA is an active lytic polysaccharide monooxygenase

    NARCIS (Netherlands)

    Loose, Jennifer S. M.; Forsberg, Zarah; Fraaije, Marco W.; Eijsink, Vincent G. H.; Vaaje-Kolstad, Gustav

    2014-01-01

    The discovery of the copper-dependent lytic polysaccharide monooxygenases (LPMOs) has revealed new territory for chemical and biochemical analysis. These unique mononuclear copper enzymes are abundant, suggesting functional diversity beyond their established roles in the depolymerization of biomass

  17. Inhibition of Epstein-Barr Virus Lytic Cycle by an Ethyl Acetate Subfraction Separated from Polygonum cuspidatum Root and Its Major Component, Emodin

    Directory of Open Access Journals (Sweden)

    Ching-Yi Yiu

    2014-01-01

    Full Text Available Polygonum cuspidatum is widely used as a medicinal herb in Asia. In this study, we examined the ethyl acetate subfraction F3 obtained from P. cuspidatum root and its major component, emodin, for their capacity to inhibit the Epstein-Barr virus (EBV lytic cycle. The cell viability was determined by the MTT [3-(4,5-dimethyldiazol-2-yl-2,5-diphenyltetrazolium bromide] method. The expression of EBV lytic proteins was analyzed by immunoblot, indirect immunofluorescence and flow cytometric assays. Real-time quantitative PCR was used to assess the EBV DNA replication and the transcription of lytic genes, including BRLF1 and BZLF1. Results showed that the F3 and its major component emodin inhibit the transcription of EBV immediate early genes, the expression of EBV lytic proteins, including Rta, Zta, and EA-D and reduces EBV DNA replication, showing that F3 and emodin are potentially useful as an anti-EBV drug.

  18. A novel role of IL-17–producing lymphocytes in mediating lytic bone disease in multiple myeloma

    Science.gov (United States)

    Noonan, Kimberly; Marchionni, Luigi; Anderson, Judy; Pardoll, Drew; Roodman, G. David

    2010-01-01

    Osteoclast (OC)–mediated lytic bone disease remains a cause of major morbidity in multiple myeloma. Here we demonstrate the critical role of interleukin-17–producing marrow infiltrating lymphocytes (MILs) in OC activation and development of bone lesions in myeloma patients. Unlike MILs from normal bone marrow, myeloma MILs possess few regulatory T cells (Tregs) and demonstrate an interleukin-17 phenotype that enhances OC activation. In univariate analyses of factors mediating bone destruction, levels of cytokines that selectively induce and maintain the Th17 phenotype tightly correlated with the extent of bone disease in myeloma. In contrast, MILs activated under conditions that skew toward a Th1 phenotype significantly reduced formation of mature OC. These findings demonstrate that interleukin-17 T cells are critical to the genesis of myeloma bone disease and that immunologic manipulations shifting MILs from a Th17 to a Th1 phenotype may profoundly diminish lytic bone lesions in multiple myeloma. PMID:20664052

  19. The algae-lytic ability of bacterium DC10 and the influence of environmental factors on the ability

    Institute of Scientific and Technical Information of China (English)

    SHI Shunyu; LIU Yongding; SHEN Yinwu; LI Genbao

    2005-01-01

    A lysing-bacterium DC10, isolated from Dianchi Lake of Yunnan Province, was characterized to be Pseudomonas sp. It was able to lyse some algae well, such as Microcystis viridis, Selenastrum capricornutum, and so on. In this study, it was shown that the bacterium lysed the algae by releasing a substance; the best lytic effects were achieved at Iow temperatures and in the dark. Different concentrations of CaCI2 and NaNO3 influenced the lytic effects;the ability to lyse algae decreased in the following order: pH 4 > pH 9 > pH 7 > pH 5.5. It was significant to develop a special technology with this kind of bacterium for controlling the bloomforming planktonic microalgae.

  20. The Role of Microorganisms in Marine Corrosion

    Science.gov (United States)

    1990-02-12

    Electrochemical evaluation of hydrogen embrittlement by microorganisms. ’The Electrochemical Society ,’ 175th meeting, Los Angeles, CA. 4. Black, J.P...microbiologically-produced hydrogen permeation through palladium. Journal of the Electrochemical Society . (In Press). INVENTIONS: None TRAINING ACTIVITIES

  1. Detection of microorganisms using terahertz metamaterials.

    Science.gov (United States)

    Park, S J; Hong, J T; Choi, S J; Kim, H S; Park, W K; Han, S T; Park, J Y; Lee, S; Kim, D S; Ahn, Y H

    2014-05-16

    Microorganisms such as fungi and bacteria cause many human diseases and therefore rapid and accurate identification of these substances is essential for effective treatment and prevention of further infections. In particular, contemporary microbial detection technique is limited by the low detection speed which usually extends over a couple of days. Here we demonstrate that metamaterials operating in the terahertz frequency range shows promising potential for use in fabricating the highly sensitive and selective microbial sensors that are capable of high-speed on-site detection of microorganisms in both ambient and aqueous environments. We were able to detect extremely small amounts of the microorganisms, because their sizes are on the same scale as the micro-gaps of the terahertz metamaterials. The resonant frequency shift of the metamaterials was investigated in terms of the number density and the dielectric constants of the microorganisms, which was successfully interpreted by the change in the effective dielectric constant of a gap area.

  2. Mass Spectrometry for Rapid Characterization of Microorganisms

    Science.gov (United States)

    Demirev, Plamen A.; Fenselau, Catherine

    2008-07-01

    Advances in instrumentation, proteomics, and bioinformatics have contributed to the successful applications of mass spectrometry (MS) for detection, identification, and classification of microorganisms. These MS applications are based on the detection of organism-specific biomarker molecules, which allow differentiation between organisms to be made. Intact proteins, their proteolytic peptides, and nonribosomal peptides have been successfully utilized as biomarkers. Sequence-specific fragments for biomarkers are generated by tandem MS of intact proteins or proteolytic peptides, obtained after, for instance, microwave-assisted acid hydrolysis. In combination with proteome database searching, individual biomarker proteins are unambiguously identified from their tandem mass spectra, and from there the source microorganism is also identified. Such top-down or bottom-up proteomics approaches permit rapid, sensitive, and confident characterization of individual microorganisms in mixtures and are reviewed here. Examples of MS-based functional assays for detection of targeted microorganisms, e.g., Bacillus anthracis, in environmental or clinically relevant backgrounds are also reviewed.

  3. Phosphoproteomic Analysis of KSHV-Infected Cells Reveals Roles of ORF45-Activated RSK during Lytic Replication.

    Directory of Open Access Journals (Sweden)

    Denis Avey

    2015-07-01

    Full Text Available Kaposi's Sarcoma-Associated Herpesvirus (KSHV is an oncogenic virus which has adapted unique mechanisms to modulate the cellular microenvironment of its human host. The pathogenesis of KSHV is intimately linked to its manipulation of cellular signaling pathways, including the extracellular signal-regulated kinase (ERK mitogen-activated protein kinase (MAPK pathway. We have previously shown that KSHV ORF45 contributes to the sustained activation of both ERK and p90 ribosomal S6 kinase (RSK, a major functional mediator of ERK/MAPK signaling during KSHV lytic replication. ORF45-activated RSK is required for optimal KSHV lytic gene expression and progeny virion production, though the underlying mechanisms downstream of this activation are still unclear. We hypothesized that the activation of RSK by ORF45 causes differential phosphorylation of cellular and viral substrates, affecting biological processes essential for efficient KSHV lytic replication. Accordingly, we observed widespread and significant differences in protein phosphorylation upon induction of lytic replication. Mass-spectrometry-based phosphoproteomic screening identified putative substrates of ORF45-activated RSK in KSHV-infected cells. Bioinformatic analyses revealed that nuclear proteins, including several transcriptional regulators, were overrepresented among these candidates. We validated the ORF45/RSK-dependent phosphorylation of several putative substrates by employing KSHV BAC mutagenesis, kinase inhibitor treatments, and/or CRISPR-mediated knockout of RSK in KSHV-infected cells. Furthermore, we assessed the consequences of knocking out these substrates on ORF45/RSK-dependent regulation of gene expression and KSHV progeny virion production. Finally, we show data to support that ORF45 regulates the translational efficiency of a subset of viral/cellular genes with complex secondary structure in their 5' UTR. Altogether, these data shed light on the mechanisms by which KSHV ORF45

  4. Morphological diversity of cultured cold-active lytic bacteriophages isolated from the Napahai plateau wetland in China

    Institute of Scientific and Technical Information of China (English)

    Xiuling Ji; Chunjing Zhang; Anxiu Kuang; Jiankai Li; Yinshan Cui; Kunhao Qin; Lianbing Lin; Benxu Cheng; Qi Zhang; Yunlin Wei

    2015-01-01

    Dear Editor,Viruses are the most abundant,diverse,and ubiquitous entities(approximately 1031)on Earth.They play major roles in horizontal gene transfer,the regulation of bacterial community structures,as well as nutrient and energy cycles of marine ecosystems(Danovaro et al.,2008).In particular,lytic bacteriophages(phages)can infect and kill bacteria without harming human or animal

  5. In vitro and in vivo analyses of the Bacillus anthracis spore cortex lytic protein SleL

    OpenAIRE

    2012-01-01

    The bacterial endospore is the most resilient biological structure known. Multiple protective integument layers shield the spore core and promote spore dehydration and dormancy. Dormancy is broken when a spore germinates and becomes a metabolically active vegetative cell. Germination requires the breakdown of a modified layer of peptidoglycan (PG) known as the spore cortex. This study reports in vitro and in vivo analyses of the Bacillus anthracis SleL protein. SleL is a spore cortex lytic en...

  6. Alkaliphilic Micro-organisms and Habitats

    OpenAIRE

    Ulukanli, Zeynep

    2002-01-01

    Alkaline environments are typical extreme environments which include naturally occurring soda lakes, deserts, soils and artificially occurring industrial-derived waters. Micro-organisms that occupy extreme pH environments have resulted in the definition of an unusual group, termed alkaliphiles. In this review, the current status of the biodiversity of alkaliphilic micro-organisms in various environments and aspects of their biotechnological potential are summarised briefly.

  7. Reactions of fish to microorganisms in wastewater.

    OpenAIRE

    1985-01-01

    Fish were inoculated with various microorganisms present in wastewater. A threshold concentration was determined over which these microorganisms were recovered from the muscles. The threshold concentrations were different for bacteria, bacteriophages, and polio 1 LSc virus. The threshold values were lower when fish were inoculated than when they were immersed in water containing these organisms. Depuration experiments were efficient when the fish did not contain high concentrations of bacteri...

  8. Potential antiviral lignans from the roots of Saururus chinensis with activity against Epstein-Barr virus lytic replication.

    Science.gov (United States)

    Cui, Hui; Xu, Bo; Wu, Taizong; Xu, Jun; Yuan, Yan; Gu, Qiong

    2014-01-24

    Epstein-Barr virus (EBV) is a member of the γ-herpes virus subfamily and has been implicated in the pathogenesis of several human malignancies. Bioassay-guided fractionation was conducted on an EtOAc-soluble extract of the roots of Saururus chinensis and monitored using an EBV lytic replication assay. This led to the isolation of 19 new (1-19) and nine known (20-28) lignans. The absolute configurations of the new lignans were established by Mosher's ester, ECD, and computational methods. Eight lignans, including three sesquineolignans (19, 23, and 24) and five dineolignans (3, 4, 26, 27, and 28), exhibited inhibitory effects toward EBV lytic replication with EC50 values from 1.09 to 7.55 μM and SI values from 3.3 to 116.4. In particular, manassantin B (27) exhibited the most promising inhibition, with an EC50 of 1.72 μM, low cytotoxicity, CC50 > 200 μM, and SI > 116.4. This is the first study demonstrating that lignans possess anti-EBV lytic replication activity.

  9. Advanced lytic lesion is a poor mobilization factor in peripheral blood stem cell collection in patients with multiple myeloma.

    Science.gov (United States)

    Jung, Sung-Hoon; Yang, Deok-Hwan; Ahn, Jae-Sook; Kim, Yeo-Kyeoung; Kim, Hyeoung-Joon; Lee, Je-Jung

    2014-12-01

    This study examined the incidence and predictors of peripheral blood stem cell (PBSC) mobilization failure in patients with multiple myeloma (MM). Retrospective data for 104 patients who received granulocyte colony-stimulating factor (G-CSF) alone or with cyclophosphamide as mobilization regimens were analyzed. The rates of mobilization failure using two definitions of failure (mobilization failure were evaluated using logistic regression analysis which included age, advanced osteolytic lesions, bone marrow cellularity before mobilization, platelet count, body mass index before mobilization, and mobilization method. Lytic bone lesions were assessed using a conventional skeletal survey, and advanced osteolytic lesions were defined as lytic lesions in more than three skeletal sites regardless of the number of lytic lesions. On multivariate analysis, advanced osteolytic lesions [hazard ratio (HR) = 10.95, P = 0.001] and age ≥60 years (HR = 5.45, P = 0.016) were associated with a PBSC yield mobilization (HR = 4.72, P = 0.005), and G-CSF only mobilization (HR 10.52, P mobilization failure in MM patients.

  10. Biomimetic aqueous-core lipid nanoballoons integrating a multiple emulsion formulation: a suitable housing system for viable lytic bacteriophages.

    Science.gov (United States)

    Balcão, Victor M; Glasser, Cássia A; Chaud, Marco V; del Fiol, Fernando S; Tubino, Matthieu; Vila, Marta M D C

    2014-11-01

    The emergence of antibiotic-resistant bacterial strains and the weak penetration of antibiotics into bacterial biofilms put an emphasis in the need for safe and effective alternatives for antimicrobial treatments. The application of strictly lytic bacteriophages (or phages) has been proposed as an alternative (or complement) to conventional antibiotics, allowing release of the natural predators of bacteria directly to the site of infection. In the present research effort, production of bacteriophage derivatives (starting from lytic phage particle isolates), encompassing full stabilization of their three-dimensional structure, has been attempted via housing said bacteriophage particles within lipid nanovesicles integrating a multiple water-in-oil-in-water (W/O/W) emulsion. As a proof-of-concept for the aforementioned strategy, bacteriophage particles with broad lytic spectrum were entrapped within the aqueous core of lipid nanoballoons integrating a W/O/W multiple emulsion. Long-term storage of the multiple emulsions produced did not lead to leaching of phage particles, thus proving the effectiveness of the encapsulation procedure.

  11. Isolation and characterization of five lytic bacteriophages infecting a Vibrio strain closely related to Vibrio owensii.

    Science.gov (United States)

    Yu, Yan-Ping; Gong, Ting; Jost, Günter; Liu, Wen-Hua; Ye, De-Zan; Luo, Zhu-Hua

    2013-11-01

    Vibrio owensii is a potential bacterial pathogen in marine aquaculture system. In this study, five lytic phages specific against Vibrio strain B8D, closely related to V. owensii, were isolated from seawater of an abalone farm. The phages were characterized with respect to morphology, genome size, growth phenotype, as well as thermal, and pH stability. All phages were found to belong to the family Siphoviridae with long noncontractile tails and terminal fibers. Restriction analysis indicated that the five phages were dsDNA viruses with molecular weights ranging from c. 30 to 48 kb. One-step growth experiments revealed that the phages were heterogeneous in latent periods (10-70 min), rise periods (40-70 min), and burst sizes [23-331 plaque-forming units (PFU) per infected cell] at the same host strain. All phages were thermal stable and were tolerant to a wide range of pH. The results indicated that these phages could be potential candidates of a phage cocktail for biological control of V. owensii in aquaculture systems.

  12. Determination of lytic enzyme activities of indigenous Trichoderma isolates from Pakistan.

    Science.gov (United States)

    Asad, Saeed Ahmad; Tabassum, Ayesha; Hameed, Abdul; Hassan, Fayyaz Ul; Afzal, Aftab; Khan, Sabaz Ali; Ahmed, Rafiq; Shahzad, Muhammad

    2015-01-01

    This study investigated lytic enzyme activities in three indigenous Trichoderma strains namely, Trichoderma asperellum, Trichoderma harzianum and Trichoderma sp. Native Trichoderma strains and a virulent strain of Rhizoctonia solani isolated from infected bean plants were also included in the study. Enzyme activities were determined by measuring sugar reduction by dinitrosalicylic acid (DNS) method using suitable substrates. The antagonists were cultured in minimal salt medium with the following modifications: medium A (1 g of glucose), medium B (0.5 g of glucose + 0.5 g of deactivated R. solani mycelia), medium C (1.0 g of deactivated respective antagonist mycelium) and medium D (1 g of deactivated R. solani mycelia). T asperellum showed presence of higher amounts of chitinases, β-1, 3-glucanases and xylanases in extracellular protein extracts from medium D as compared to medium A. While, the higher activities of glucosidases and endoglucanses were shown in medium D extracts by T. harzianum. β-glucosidase activities were lower compared with other enzymes; however, activities of the extracts of medium D were significantly different. T. asperellum exhibited maximum inhibition (97.7%). On the other hand, Trichoderma sp. did not show any effect on mycelia growth of R. solani on crude extract.

  13. Lytic phages obscure the cost of antibiotic resistance in Escherichia coli

    Science.gov (United States)

    Tazzyman, Samuel J; Hall, Alex R

    2015-01-01

    The long-term persistence of antibiotic-resistant bacteria depends on their fitness relative to other genotypes in the absence of drugs. Outside the laboratory, viruses that parasitize bacteria (phages) are ubiquitous, but costs of antibiotic resistance are typically studied in phage-free experimental conditions. We used a mathematical model and experiments with Escherichia coli to show that lytic phages strongly affect the incidence of antibiotic resistance in drug-free conditions. Under phage parasitism, the likelihood that antibiotic-resistant genetic backgrounds spread depends on their initial frequency, mutation rate and intrinsic growth rate relative to drug-susceptible genotypes, because these parameters determine relative rates of phage-resistance evolution on different genetic backgrounds. Moreover, the average cost of antibiotic resistance in terms of intrinsic growth in the antibiotic-free experimental environment was small relative to the benefits of an increased mutation rate in the presence of phages. This is consistent with our theoretical work indicating that, under phage selection, typical costs of antibiotic resistance can be outweighed by realistic increases in mutability if drug resistance and hypermutability are genetically linked, as is frequently observed in clinical isolates. This suggests the long-term distribution of antibiotic resistance depends on the relative rates at which different lineages adapt to other types of selection, which in the case of phage parasitism is probably extremely common, as well as costs of resistance inferred by classical in vitro methods. PMID:25268496

  14. Characterization and function of kuruma shrimp lysozyme possessing lytic activity against Vibrio species.

    Science.gov (United States)

    Hikima, Sonomi; Hikima, Jun ichi; Rojtinnakorn, Jiraporn; Hirono, Ikuo; Aoki, Takashi

    2003-10-16

    Lysozyme cDNA was isolated from a kuruma shrimp, Marsupenaeus japonicus, hemocyte cDNA library. The cDNA consists of 1055 base pairs (bp) and encodes a chicken-type (c-type) lysozyme with a deduced amino acid sequence of 156 residues. The kuruma shrimp lysozyme has a high identity (79.7%) with pacific white shrimp lysozyme, and low to moderate identities (33.3-43.0%) with lysozymes of insects and vertebrates. Comparisons with other c-type lysozymes from invertebrates and vertebrates showed that the two catalytic residues (Glu58 and Asp75) and the eight cysteine residue motif were completely conserved. Two novel insertion sequences were also observed in the kuruma and pacific white shrimp lysozyme amino acid sequences. Interestingly, phylogenetic analysis revealed that the kuruma shrimp lysozyme was more closely related to vertebrate c-type lysozymes. Expression of the cDNA in insect cells, using a baculovirus expression system, yielded a recombinant lysozyme with optimum activity at pH 7.5 and 50 degrees C, as evaluated by a lysoplate assay. The kuruma shrimp lysozyme displayed lytic activities against several Vibrio species and fish pathogens, including Vibrio penaeicida (a pathogenic bacteria to the kuruma shrimp) and suggested that shrimp lysozyme affects a greater variety of pathogens.

  15. Hemoglobin is a co-factor of human trypanosome lytic factor.

    Directory of Open Access Journals (Sweden)

    Justin Widener

    2007-09-01

    Full Text Available Trypanosome lytic factor (TLF is a high-density lipoprotein (HDL subclass providing innate protection to humans against infection by the protozoan parasite Trypanosoma brucei brucei. Two primate-specific plasma proteins, haptoglobin-related protein (Hpr and apolipoprotein L-1 (ApoL-1, have been proposed to kill T. b. brucei both singularly or when co-assembled into the same HDL. To better understand the mechanism of T. b. brucei killing by TLF, the protein composition of TLF was investigated using a gentle immunoaffinity purification technique that avoids the loss of weakly associated proteins. HDL particles recovered by immunoaffinity absorption, with either anti-Hpr or anti-ApoL-1, were identical in protein composition and specific activity for T. b. brucei killing. Here, we show that TLF-bound Hpr strongly binds Hb and that addition of Hb stimulates TLF killing of T. b. brucei by increasing the affinity of TLF for its receptor, and by inducing Fenton chemistry within the trypanosome lysosome. These findings suggest that TLF in uninfected humans may be inactive against T. b. brucei prior to initiation of infection. We propose that infection of humans by T. b. brucei causes hemolysis that triggers the activation of TLF by the formation of Hpr-Hb complexes, leading to enhanced binding, trypanolytic activity, and clearance of parasites.

  16. Non-lytic, actin-based exit of intracellular parasites from C. elegans intestinal cells.

    Science.gov (United States)

    Estes, Kathleen A; Szumowski, Suzannah C; Troemel, Emily R

    2011-09-01

    The intestine is a common site for invasion by intracellular pathogens, but little is known about how pathogens restructure and exit intestinal cells in vivo. The natural microsporidian parasite N. parisii invades intestinal cells of the nematode C. elegans, progresses through its life cycle, and then exits cells in a transmissible spore form. Here we show that N. parisii causes rearrangements of host actin inside intestinal cells as part of a novel parasite exit strategy. First, we show that N. parisii infection causes ectopic localization of the normally apical-restricted actin to the basolateral side of intestinal cells, where it often forms network-like structures. Soon after this actin relocalization, we find that gaps appear in the terminal web, a conserved cytoskeletal structure that could present a barrier to exit. Reducing actin expression creates terminal web gaps in the absence of infection, suggesting that infection-induced actin relocalization triggers gap formation. We show that terminal web gaps form at a distinct stage of infection, precisely timed to precede spore exit, and that all contagious animals exhibit gaps. Interestingly, we find that while perturbations in actin can create these gaps, actin is not required for infection progression or spore formation, but actin is required for spore exit. Finally, we show that despite large numbers of spores exiting intestinal cells, this exit does not cause cell lysis. These results provide insight into parasite manipulation of the host cytoskeleton and non-lytic escape from intestinal cells in vivo.

  17. Production of four Neurospora crassa lytic polysaccharide monooxygenases in Pichia pastoris monitored by a fluorimetric assay.

    Science.gov (United States)

    Kittl, Roman; Kracher, Daniel; Burgstaller, Daniel; Haltrich, Dietmar; Ludwig, Roland

    2012-10-26

    Recent studies demonstrate that enzymes from the glycosyl hydrolase family 61 (GH61) show lytic polysaccharide monooxygenase (PMO) activity. Together with cellobiose dehydrogenase (CDH) an enzymatic system capable of oxidative cellulose cleavage is formed, which increases the efficiency of cellulases and put PMOs at focus of biofuel research. Large amounts of purified PMOs, which are difficult to obtain from the native fungal producers, are needed to study their reaction kinetics, structure and industrial application. In addition, a fast and robust enzymatic assay is necessary to monitor enzyme production and purification. Four pmo genes from Neurospora crassa were expressed in P. pastoris under control of the AOX1 promoter. High yields were obtained for the glycosylated gene products PMO-01867, PMO-02916 and PMO-08760 (>300 mg L-1), whereas the yield of non-glycosylated PMO-03328 was moderate (~45 mg L-1). The production and purification of all four enzymes was specifically followed by a newly developed, fast assay based on a side reaction of PMO: the production of H2O2 in the presence of reductants. While ascorbate is a suitable reductant for homogeneous PMO preparations, fermentation samples require the specific electron donor CDH. P. pastoris is a high performing expression host for N. crassa PMOs. The pmo genes under control of the native signal sequence are correctly processed and active. The novel CDH-based enzyme assay allows fast determination of PMO activity in fermentation samples and is robust against interfering matrix components.

  18. Involvement of Noxa in mediating cellular ER stress responses to lytic virus infection.

    Science.gov (United States)

    Rosebeck, Shaun; Sudini, Kuladeep; Chen, Tiannan; Leaman, Douglas W

    2011-09-01

    Noxa is a Bcl-2 homology domain-containing pro-apoptotic mitochondrial protein. Noxa mRNA and protein expression are upregulated by dsRNA or virus, and ectopic Noxa expression enhances cellular sensitivity to virus or dsRNA-induced apoptosis. Here we demonstrate that Noxa null baby mouse kidney (BMK) cells are deficient in normal cytopathic response to lytic viruses, and that reconstitution of the knockout cells with wild-type Noxa restored normal cytopathic responses. Noxa regulation by virus mirrored its regulation by proteasome inhibitors or ER stress inducers and the ER stress response inhibitor salubrinal protected cells against viral cytopathic effects. Noxa mRNA and protein were synergistically upregulated by IFN or dsRNA when combined with ER stress inducers, leading to Noxa/Mcl-1 interaction, activation of Bax and pro-apoptotic caspases, degradation of Mcl-1, loss of mitochondrial membrane potential and initiation of apoptosis. These data highlight the importance of ER stress in augmenting the expression of Noxa following viral infection.

  19. Isolation and characterisation of lytic bacteriophages of Klebsiella pneumoniae and Klebsiella oxytoca.

    Science.gov (United States)

    Karumidze, Natia; Kusradze, Ia; Rigvava, Sophio; Goderdzishvili, Marine; Rajakumar, Kumar; Alavidze, Zemphira

    2013-03-01

    Klebsiella bacteria have emerged as an increasingly important cause of community-acquired nosocomial infections. Extensive use of broad-spectrum antibiotics in hospitalised patients has led to both increased carriage of Klebsiella and the development of multidrug-resistant strains that frequently produce extended-spectrum β-lactamases and/or other defences against antibiotics. Many of these strains are highly virulent and exhibit a strong propensity to spread. In this study, six lytic Klebsiella bacteriophages were isolated from sewage-contaminated river water in Georgia and characterised as phage therapy candidates. Two of the phages were investigated in greater detail. Biological properties, including phage morphology, nucleic acid composition, host range, growth phenotype, and thermal and pH stability were studied for all six phages. Limited sample sequencing was performed to define the phylogeny of the K. pneumoniae- and K. oxytoca-specific bacteriophages vB_Klp_5 and vB_Klox_2, respectively. Both of the latter phages had large burst sizes, efficient rates of adsorption and were stable under different adverse conditions. Phages reported in this study are double-stranded DNA bacterial viruses belonging to the families Podoviridae and Siphoviridae. One or more of the six phages was capable of efficiently lysing ~63 % of Klebsiella strains comprising a collection of 123 clinical isolates from Georgia and the United Kingdom. These phages exhibit a number of properties indicative of potential utility in phage therapy cocktails.

  20. Characterisation and genome sequence of the lytic Acinetobacter baumannii bacteriophage vB_AbaS_Loki

    Science.gov (United States)

    Wand, Matthew E.; Briers, Yves; Lavigne, Rob; Sutton, J. Mark; Reynolds, Darren M.

    2017-01-01

    Acinetobacter baumannii has emerged as an important nosocomial pathogen in healthcare and community settings. While over 100 of Acinetobacter phages have been described in the literature, relatively few have been sequenced. This work describes the characterisation and genome annotation of a new lytic Acinetobacter siphovirus, vB_AbaS_Loki, isolated from activated sewage sludge. Sequencing revealed that Loki encapsulates a 41,308 bp genome, encoding 51 predicted open reading frames. Loki is most closely related to Acinetobacter phage IME_AB3 and more distantly related to Burkholderia phage KL1, Paracoccus phage vB_PmaS_IMEP1 and Pseudomonas phages vB_Pae_Kakheti25, vB_PaeS_SCH_Ab26 and PA73. Loki is characterised by a narrow host range, among the 40 Acinetobacter isolates tested, productive infection was only observed for the propagating host, A. baumannii ATCC 17978. Plaque formation was found to be dependent upon the presence of Ca2+ ions and adsorption to host cells was abolished upon incubation with a mutant of ATCC 17978 encoding a premature stop codon in lpxA. The complete genome sequence of vB_AbaS_Loki was deposited in the European Nucleotide Archive (ENA) under the accession number LN890663. PMID:28207864

  1. Syntaxin 8 is required for efficient lytic granule trafficking in cytotoxic T lymphocytes.

    Science.gov (United States)

    Bhat, Shruthi S; Friedmann, Kim S; Knörck, Arne; Hoxha, Cora; Leidinger, Petra; Backes, Christina; Meese, Eckart; Keller, Andreas; Rettig, Jens; Hoth, Markus; Qu, Bin; Schwarz, Eva C

    2016-07-01

    Cytotoxic T lymphocytes (CTL) eliminate pathogen-infected and cancerous cells mainly by polarized secretion of lytic granules (LG, containing cytotoxic molecules like perforin and granzymes) at the immunological synapse (IS). Members of the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) family are involved in trafficking (generation, transport and fusion) of vesicles at the IS. Syntaxin 8 (Stx8) is expressed in LG and colocalizes with the T cell receptor (TCR) upon IS formation. Here, we report the significance of Stx8 for human CTL cytotoxicity. We found that Stx8 mostly localized in late, recycling endosomal and lysosomal compartments with little expression in early endosomal compartments. Down-regulation of Stx8 by siRNA resulted in reduced cytotoxicity. We found that following perforin release of the pre-existing pool upon target cell contact, Stx8 down-regulated CTL regenerate perforin pools less efficiently and thus release less perforin compared to control CTL. CD107a degranulation, real-time and end-point population cytotoxicity assays, and high resolution microscopy support our conclusion that Stx8 is required for proper and timely sorting and trafficking of cytotoxic molecules to functional LG through the endosomal pathway in human CTL.

  2. Determination of lytic enzyme activities of indigenous Trichoderma isolates from Pakistan

    Science.gov (United States)

    Asad, Saeed Ahmad; Tabassum, Ayesha; Hameed, Abdul; Hassan, Fayyaz ul; Afzal, Aftab; Khan, Sabaz Ali; Ahmed, Rafiq; Shahzad, Muhammad

    2015-01-01

    Abstract This study investigated lytic enzyme activities in three indigenous Trichoderma strains namely, Trichoderma asperellum, Trichoderma harzianum and Trichoderma sp. Native Trichoderma strains and a virulent strain of Rhizoctonia solani isolated from infected bean plants were also included in the study. Enzyme activities were determined by measuring sugar reduction by dinitrosalicylic acid (DNS) method using suitable substrates. The antagonists were cultured in minimal salt medium with the following modifications: medium A (1 g of glucose), medium B (0.5 g of glucose + 0.5 g of deactivated R. solani mycelia), medium C (1.0 g of deactivated respective antagonist mycelium) and medium D (1 g of deactivated R. solani mycelia). T asperellum showed presence of higher amounts of chitinases, β-1, 3-glucanases and xylanases in extracellular protein extracts from medium D as compared to medium A. While, the higher activities of glucosidases and endoglucanses were shown in medium D extracts by T. harzianum. β-glucosidase activities were lower compared with other enzymes; however, activities of the extracts of medium D were significantly different. T. asperellum exhibited maximum inhibition (97.7%). On the other hand, Trichoderma sp. did not show any effect on mycelia growth of R. solani on crude extract. PMID:26691463

  3. Parachlamydia acanthamoeba is endosymbiotic or lytic for Acanthamoeba polyphaga depending on the incubation temperature.

    Science.gov (United States)

    Greub, Gilbert; La Scola, Bernard; Raoult, Didier

    2003-06-01

    Parachlamydiaceae are potential emerging pathogens that naturally infect free-living amoebae. We investigated the affects of incubation temperature on the growth and cytopathic effect of P. acanthamoeba in Acanthamoeba polyphaga. A. polyphaga were infected with P. acanthamoeba and incubated at different temperatures for ten days. Bacterial growth was quantified by real-time PCR. Cytopathic effects were determined by counting the number of cysts and viable amoebae (unstained with trypan blue) in Nageotte counting chambers. Uninfected amoebae cultures were used as negative control. At 32, 35, and 37 degrees C, we observed a significant decrease in the number of viable A. polyphaga that contrasted with the delayed and smaller decrease in the number of living A. polyphaga observed at 25, 28, and 30 degrees C. Higher incubation temperature, which is associated with amoebal lysis, surprisingly was not associated with increased growth rate. P. acanthamoeba is lytic for A. polyphaga at 32-37 degrees C but endosymbiotic at 25-30 degrees C. This suggests that A. polyphaga may be a reservoir of endosymbionts at the lower temperature of the nasal mucosa, which may be liberated by lysis at higher temperature, for instance, when the amoeba is inhaled and reaches the lower respiratory tract.

  4. Identification of a membrane-bound prepore species clarifies the lytic mechanism of actinoporins

    CERN Document Server

    Morante, Koldo; Gil-Cartón, David; Redondo-Morata, Lorena; Sot, Jesús; Scheuring, Simon; Valle, Mikel; González-Mañas, Juan Manuel; Tsumoto, Kouhei; Caaveiro, Jose M M

    2016-01-01

    Pore-forming toxins (PFT) are cytolytic proteins belonging to the molecular warfare apparatus of living organisms. The assembly of the functional transmembrane pore requires several intermediate steps ranging from a water-soluble monomeric species to the multimeric ensemble inserted in the cell membrane. The non-lytic oligomeric intermediate known as prepore plays an essential role in the mechanism of insertion of the class of $\\beta$-PFT. However, in the class of $\\alpha$-PFT like the actinoporins produced by sea anemones, evidence of membrane-bound prepores is still lacking. We have employed single-particle cryo-electron microscopy (cryo-EM) and atomic force microscopy (AFM) to identify, for the first time, a prepore species of the actinoporin fragaceatoxin C (FraC) bound to lipid vesicles. The size of the prepore coincides that of the functional pore, except for the transmembrane region, which is absent in the prepore. Biochemical assays indicated that, in the prepore species, the N-terminus is not inserte...

  5. Characterization of potential lytic bacteriophage against Vibrio alginolyticus and its therapeutic implications on biofilm dispersal.

    Science.gov (United States)

    Sasikala, Dakshinamurthy; Srinivasan, Pappu

    2016-12-01

    Vibrio alginolyticus is a leading cause of vibriosis, presenting opportunistic infections to humans associated with raw seafood contamination. At present, phage therapy that acts as an alternative sanitizing agent is explored for targeting V. alginolyticus. The study outcome revealed that the phage VP01 with its extreme lytic effect showed a high potential impact on the growth of V. alginolyticus as well as biofilm formation. Electron microscopy revealed the phage resemblance to Myoviridae, based on its morphology. Further study clarified that the phage VP01 possesses a broad host spectrum and amazing phage sensitivity at different pH, high thermal stability, and high burst size of 415 PFU/cell. In addition, the investigation of phage co-culturing against this pathogen resulted in a significant growth reduction even at less MOIs 0.1 and 1. These results suggest that the phage could be a promising candidate for the control of V. alginolyticus infections. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Chromatin Modulation of Herpesvirus Lytic Gene Expression: Managing Nucleosome Density and Heterochromatic Histone Modifications

    Directory of Open Access Journals (Sweden)

    Thomas M. Kristie

    2016-03-01

    Full Text Available Like their cellular hosts, herpesviruses are subject to the regulatory impacts of chromatin assembled on their genomes. Upon infection, these viruses are assembled into domains of chromatin with heterochromatic signatures that suppress viral gene expression or euchromatic characteristics that promote gene expression. The organization and modulation of these chromatin domains appear to be intimately linked to the coordinated expression of the different classes of viral genes and thus ultimately play an important role in the progression of productive infection or the establishment and maintenance of viral latency. A recent report from the Knipe laboratory (J. S. Lee, P. Raja, and D. M. Knipe, mBio 7:e02007-15, 2016 contributes to the understanding of the dynamic modulation of chromatin assembled on the herpes simplex virus genome by monitoring the levels of characteristic heterochromatic histone modifications (histone H3 lysine 9 and 27 methylation associated with a model viral early gene during the progression of lytic infection. Additionally, this study builds upon previous observations that the viral immediate-early protein ICP0 plays a role in reducing the levels of heterochromatin associated with the early genes.

  7. Lytic phages obscure the cost of antibiotic resistance in Escherichia coli.

    Science.gov (United States)

    Tazzyman, Samuel J; Hall, Alex R

    2015-03-17

    The long-term persistence of antibiotic-resistant bacteria depends on their fitness relative to other genotypes in the absence of drugs. Outside the laboratory, viruses that parasitize bacteria (phages) are ubiquitous, but costs of antibiotic resistance are typically studied in phage-free experimental conditions. We used a mathematical model and experiments with Escherichia coli to show that lytic phages strongly affect the incidence of antibiotic resistance in drug-free conditions. Under phage parasitism, the likelihood that antibiotic-resistant genetic backgrounds spread depends on their initial frequency, mutation rate and intrinsic growth rate relative to drug-susceptible genotypes, because these parameters determine relative rates of phage-resistance evolution on different genetic backgrounds. Moreover, the average cost of antibiotic resistance in terms of intrinsic growth in the antibiotic-free experimental environment was small relative to the benefits of an increased mutation rate in the presence of phages. This is consistent with our theoretical work indicating that, under phage selection, typical costs of antibiotic resistance can be outweighed by realistic increases in mutability if drug resistance and hypermutability are genetically linked, as is frequently observed in clinical isolates. This suggests the long-term distribution of antibiotic resistance depends on the relative rates at which different lineages adapt to other types of selection, which in the case of phage parasitism is probably extremely common, as well as costs of resistance inferred by classical in vitro methods.

  8. Characterisation and genome sequence of the lytic Acinetobacter baumannii bacteriophage vB_AbaS_Loki.

    Science.gov (United States)

    Turner, Dann; Wand, Matthew E; Briers, Yves; Lavigne, Rob; Sutton, J Mark; Reynolds, Darren M

    2017-01-01

    Acinetobacter baumannii has emerged as an important nosocomial pathogen in healthcare and community settings. While over 100 of Acinetobacter phages have been described in the literature, relatively few have been sequenced. This work describes the characterisation and genome annotation of a new lytic Acinetobacter siphovirus, vB_AbaS_Loki, isolated from activated sewage sludge. Sequencing revealed that Loki encapsulates a 41,308 bp genome, encoding 51 predicted open reading frames. Loki is most closely related to Acinetobacter phage IME_AB3 and more distantly related to Burkholderia phage KL1, Paracoccus phage vB_PmaS_IMEP1 and Pseudomonas phages vB_Pae_Kakheti25, vB_PaeS_SCH_Ab26 and PA73. Loki is characterised by a narrow host range, among the 40 Acinetobacter isolates tested, productive infection was only observed for the propagating host, A. baumannii ATCC 17978. Plaque formation was found to be dependent upon the presence of Ca2+ ions and adsorption to host cells was abolished upon incubation with a mutant of ATCC 17978 encoding a premature stop codon in lpxA. The complete genome sequence of vB_AbaS_Loki was deposited in the European Nucleotide Archive (ENA) under the accession number LN890663.

  9. Screening of thermotolerant microorganisms and application for oil separation from palm oil mill wastewater

    Directory of Open Access Journals (Sweden)

    Aran H-Kittikun

    2007-05-01

    Full Text Available The characteristics of palm oil mill wastewater (POMW were brown color, pH 3.8-4.3, temperature 48-55oC, total solids 68.2-82.1 g/l, suspended solids 26.2-65.6 g/l, oil and grease 19.1-25.1 g/l, COD 49.9-160.7g/l and BOD 32.5-75.3 g/l. After centrifugation (3,184 xg of 50 ml POMW for 10 min, the POMW was separated into 3 layers: top (oil, middle (supernatant and bottom layer (sediment. The sediment containeddry weight 1.19 g and oil and grease 1.07 g. In order to release oil and grease trapped in palm fiber debris in the POMW, cellulase- and/or xylanase-enzyme-producing and thermotolerant microorganisms wereisolated. The isolates SO1 and SO2 were isolated from soil near the first anaerobic pond of the palm oil mill. They were aerobic, Gram positive, rod shaped, thermotolerant microorganisms and produced cellulase 12.11 U/ml (3 days and 7.2 U/ml (4 days, and xylanase 50.98 U/ml (4 days and 20.42 U/ml (4 days, respectivelyin synthetic medium containing carboxymethycellulose as a carbon source. When these 2 isolates were added into the steriled POMW under shaking condition for 7 days, after centrifugation at 3,184 xg the isolate SO1gave the better % reduction of dry weight (64.66 % and of oil and grease in the bottom layer (85.32 % of the POMW.

  10. Functional microorganisms for functional food quality.

    Science.gov (United States)

    Gobbetti, M; Cagno, R Di; De Angelis, M

    2010-09-01

    Functional microorganisms and health benefits represent a binomial with great potential for fermented functional foods. The health benefits of fermented functional foods are expressed either directly through the interactions of ingested live microorganisms with the host (probiotic effect) or indirectly as the result of the ingestion of microbial metabolites synthesized during fermentation (biogenic effect). Since the importance of high viability for probiotic effect, two major options are currently pursued for improving it--to enhance bacterial stress response and to use alternative products for incorporating probiotics (e.g., ice cream, cheeses, cereals, fruit juices, vegetables, and soy beans). Further, it seems that quorum sensing signal molecules released by probiotics may interact with human epithelial cells from intestine thus modulating several physiological functions. Under optimal processing conditions, functional microorganisms contribute to food functionality through their enzyme portfolio and the release of metabolites. Overproduction of free amino acids and vitamins are two classical examples. Besides, bioactive compounds (e.g., peptides, γ-amino butyric acid, and conjugated linoleic acid) may be released during food processing above the physiological threshold and they may exert various in vivo health benefits. Functional microorganisms are even more used in novel strategies for decreasing phenomenon of food intolerance (e.g., gluten intolerance) and allergy. By a critical approach, this review will aim at showing the potential of functional microorganisms for the quality of functional foods.

  11. Production of fats and oils by microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Osamu

    1987-10-20

    This paper describes the production of fats and oils by microorganisms. Various fat-productive bacteria have been found to produce the fats and oils by microorganisms which are roughly classified into enzyme and filiform fungus. The cells do not proliferate under the conditions adequate for producing the cells with the high content of lipid. A cell with high content of fat belonging to Mortierella filamentas fungi has been recently obtained at high density in the high concentration culture medium. The productivity of the fat similar to cocoa butter seems to be also high. A lot of microorganisms producing various functional fatty acids have been found. The microorganismic production methods of esters of longer-chain dicarboxylic acids and alcohols than C/sub 11/ hardly produced in nature form n-alkane also have been recently developed. Squalene has been able to produce by a cell from the other raw materials than the shark oil. Various sterols exist in microorganisms. The high-productivity manufacturing method of the fats containing gamma-linoleic acid by Mortierella filiform fungi has been developed and commercialized as the first production process of the fat by the microorganism. (5 figs, 7 tabs, 128 refs

  12. Application of thermotolerant microorganisms for biofertilizer preparation.

    Science.gov (United States)

    Chen, Kuo-Shu; Lin, Yann-Shying; Yang, Shang-Shyng

    2007-12-01

    Intensive agriculture is practised in Taiwan, and compost application is very popular as a means of improving the soil physical properties and supplying plant nutrition. We tested the potential of inoculation with thermotolerant microorganisms to shorten the maturity and improve the quality of biofertilizer prepared by composting. Thermotolerant microorganisms were isolated from compost and reinoculated for the preparation of biofertilizer. The physical, chemical and biological properties of the biofertilizer were determined during composting. The effects of biofertilizer application on the growth and yield of rape were also studied. Among 3823 colonies of thermotolerant microorganisms, Streptomyces thermonitrificans NTU-88, Streptococcus sp. NTU-130 and Aspergillus fumigatus NTU-132 exhibited high growth rates and cellulolytic and proteolytic activities. When a mixture of rice straw and swine manure were inoculated with these isolates and composted for 61 days, substrate temperature increased initially and then decreased gradually during composting. Substrate pH increased from 7.3 to 8.5. Microbial inoculation enhanced the rate of maturity, and increased the content of ash and total and immobilized nitrogen, improved the germination rate of alfalfa seed, and decreased the content of total organic carbon and the carbon/nitrogen ratio. Biofertilizer application increased the growth and yield of rape. Inoculation of thermotolerant and thermophilic microorganisms to agricultural waste for biofertilizer preparation enhances the rate of maturity and improves the quality of the resulting biofertilizer. Inoculation of appropriate microorganisms in biofertilizer preparation might be usefully applied to agricultural situations.

  13. 小檗碱对外科术后产AmpC酶分离菌株的抑菌作用%Inhibitory effects of berberine on postoperative AmpC enzyme producing strains

    Institute of Scientific and Technical Information of China (English)

    徐剑; 司徒瑞儒; 林勇平

    2014-01-01

    Objective To investigate the pathogenic bacteria distribution in postoperative infection and the effects of berberine on the antibacterial effect of AmpC enzyme producing strains. Methods The bacteria producing AmpC enzyme were isolated from patients with postoperative infection, and the minimum inhibitory effects of berberine on the three kinds of isolates producing AmpC enzymes were detected by using the agar dilution method and broth dilution method. Results A total of 225 strains of G-Bacillus were isolated ,46 strains of which producing AmpC enzyme, the MIC of 27 strains was 31.25g/L berberine;26 strains of Klebsiella pneumoniae producing high AmpC, 13 of which had MIC concentration of 31.25g/L berberine;21 strains of Pseudomonas aeruginosa producing AmpC, 12 strains of which had MIC concentration of 60.25g/L berberine. The concentration of 15.62g/L berberine had no inhibitory effect on bacteria producing AmpC enzyme. There were 170 strains of G+pathogen, including 94 cases of Staphylococcus aureus, 36 cases of Staphylococcus epidermidis and 27 cases of fungus. Conclusion G-coli producing AmpC enzyme in postoperative infections are more common, and the berberine has some antibacterial effect on bacterial strains producing AmpC enzyme. In order to reduce the abuse of antibiotics and cause multiple drug resistance, it is worthy of clinical application.%目的:了解外科术后感染的病原菌分布情况并探讨小檗碱对产AmpC酶术后感染分离菌株的抗菌作用。方法从术后感染病人中分离出产AmpC酶细菌,并采用琼脂对倍稀释法、肉汤稀释法分别检测小檗碱对产AmpC酶三种分离菌株的最低抑菌作用。结果共分离出G-杆菌225株,其中产AmpC酶大肠埃希菌46株,有27株MIC为浓度31.25g/l小檗碱;高产AmpC酶肺炎克雷伯菌有26株,有13株MIC为浓度31.25g/l小檗碱;产AmpC铜绿假单胞菌21株,有12株MIC为浓度60.25g/l小檗碱。浓度为15.62g/L小檗碱对产AmpC酶

  14. A rapid, efficient and sensitive plate assay for detection and screening of l-asparaginase-producing microorganisms.

    Science.gov (United States)

    Mahajan, Richi V; Saran, Saurabh; Saxena, Rajendra K; Srivastava, Ayush K

    2013-04-01

    l-Asparaginase-producing microbes are conventionally screened on phenol red l-asparagine-containing plates. However, sometimes the contrast of the zone obtained (between yellow and pink) is not very sharp and distinct. In the present investigation, an improved method for screening of the microorganisms producing extracellular l-asparaginase is reported wherein bromothymol blue (BTB) is incorporated as pH indicator in l-asparagine-containing medium instead of phenol red. Plates containing BTB at acidic pH are yellow and turn dark blue at alkaline pH. Thus, a dense dark blue zone is formed around microbial colonies producing l-asparaginase, differentiating between enzyme producers and non-producers. The present method is more sensitive and accurate than the conventional method for screening of both fungi and bacteria producing extracellular l-asparaginase. Furthermore, BTB gives a transient green colour at neutral pH (7.0) and dark blue colour at higher pH 8.0-9.0, indicating the potency of the microorganism for l-asparaginase production.

  15. PRESENCE OF MICROORGANISMS AT VARIOUS STAGES OF POULTRY WASTES MANAGEMENT. PART I. KERATINOLYTIC MICROORGANISMS

    Directory of Open Access Journals (Sweden)

    Ilona Wrońska

    2016-11-01

    Based on the study, the presence of keratinolytic microorganisms was found in all materials. The slime was the most numerously inhabited waste, while proper compost the least. Predominant group of microorganisms, regardless of the tested material type, was composed of bacteria.

  16. Using lytic bacteriophages to eliminate or significantly reduce contamination of food by foodborne bacterial pathogens.

    Science.gov (United States)

    Sulakvelidze, Alexander

    2013-10-01

    Bacteriophages (also called 'phages') are viruses that kill bacteria. They are arguably the oldest (3 billion years old, by some estimates) and most ubiquitous (total number estimated to be 10(30) -10(32) ) known organisms on Earth. Phages play a key role in maintaining microbial balance in every ecosystem where bacteria exist, and they are part of the normal microflora of all fresh, unprocessed foods. Interest in various practical applications of bacteriophages has been gaining momentum recently, with perhaps the most attention focused on using them to improve food safety. That approach, called 'phage biocontrol', typically includes three main types of applications: (i) using phages to treat domesticated livestock in order to reduce their intestinal colonization with, and shedding of, specific bacterial pathogens; (ii) treatments for decontaminating inanimate surfaces in food-processing facilities and other food establishments, so that foods processed on those surfaces are not cross-contaminated with the targeted pathogens; and (iii) post-harvest treatments involving direct applications of phages onto the harvested foods. This mini-review primarily focuses on the last type of intervention, which has been gaining the most momentum recently. Indeed, the results of recent studies dealing with improving food safety, and several recent regulatory approvals of various commercial phage preparations developed for post-harvest food safety applications, strongly support the idea that lytic phages may provide a safe, environmentally-friendly, and effective approach for significantly reducing contamination of various foods with foodborne bacterial pathogens. However, some important technical and nontechnical problems may need to be addressed before phage biocontrol protocols can become an integral part of routine food safety intervention strategies implemented by food industries in the USA.

  17. Characterization of four lytic transducing bacteriophages of luminescent Vibrio harveyi isolated from shrimp (Penaeus monodon) hatcheries.

    Science.gov (United States)

    Thiyagarajan, Sanjeevi; Chrisolite, Bagthasingh; Alavandi, Shankar V; Poornima, Modem; Kalaimani, Natarajan; Santiago, T Chinnappan

    2011-12-01

    Four lytic bacteriophages designated as φVh1, φVh2, φVh3, and φVh4 were isolated from commercial shrimp hatcheries, possessing broad spectrum of infectivity against luminescent Vibrio harveyi isolates, considering their potential as biocontrol agent of luminescent bacterial disease in shrimp hatcheries, and were characterized by electron microscopy, genomic analysis, restriction enzyme analysis (REA), and pulsed-field gel electrophoresis (PFGE). Three phages φVh1, φVh2, and φVh4 had an icosahedral head of 60-115 nm size with a long, noncontractile tail of 130-329 × 1-17 nm, belonged to the family Siphoviridae. φVh3 had an icosahedral head (72 ± 5 nm) with a short tail (27 × 12 nm) and belonged to Podoviridae. REA with DraI and PFGE of genomic DNA digested with ScaI and XbaI and cluster analysis of their banding patterns indicated that φVh3 was distinct from the other three siphophages. PFGE-based genome mean size of the four bacteriophages φVh1, φVh2, φVh3, and φVh4 was estimated to be about 85, 58, 64, and 107 kb, respectively. These phages had the property of generalized transduction as demonstrated by transduction with plasmid pHSG 396 with frequencies ranging from 4.1 × 10(-7) to 2 × 10(-9) per plaque-forming unit, suggesting a potential ecological role in gene transfer among aquatic vibrios.

  18. killerFLIP: a novel lytic peptide specifically inducing cancer cell death.

    Science.gov (United States)

    Pennarun, B; Gaidos, G; Bucur, O; Tinari, A; Rupasinghe, C; Jin, T; Dewar, R; Song, K; Santos, M T; Malorni, W; Mierke, D; Khosravi-Far, R

    2013-10-31

    One of the objectives in the development of effective cancer therapy is induction of tumor-selective cell death. Toward this end, we have identified a small peptide that, when introduced into cells via a TAT cell-delivery system, shows a remarkably potent cytoxicity in a variety of cancer cell lines and inhibits tumor growth in vivo, whereas sparing normal cells and tissues. This fusion peptide was named killerFLIP as its sequence was derived from the C-terminal domain of c-FLIP, an anti-apoptotic protein. Using structure activity analysis, we determined the minimal bioactive core of killerFLIP, namely killerFLIP-E. Structural analysis of cells using electron microscopy demonstrated that killerFLIP-E triggers cell death accompanied by rapid (within minutes) plasma membrane permeabilization. Studies of the structure of the active core of killerFLIP (-E) indicated that it possesses amphiphilic properties and self-assembles into micellar structures in aqueous solution. The biochemical properties of killerFLIP are comparable to those of cationic lytic peptides, which participate in defense against pathogens and have also demonstrated anticancer properties. We show that the pro-cell death effects of killerFLIP are independent of its sequence similarity with c-FLIPL as killerFLIP-induced cell death was largely apoptosis and necroptosis independent. A killerFLIP-E variant containing a scrambled c-FLIPL motif indeed induced similar cell death, suggesting the importance of the c-FLIPL residues but not of their sequence. Thus, we report the discovery of a promising synthetic peptide with novel anticancer activity in vitro and in vivo.

  19. Chemical modification of methionines in a cobra venom cytotoxin differentiates between lytic and binding domains.

    Science.gov (United States)

    Stevens-Truss, R; Hinman, C L

    1996-08-01

    Cytotoxin-III from Naja naja atra (CTX) was chemically modified at either or both of its two methionine residues: Over 50% oxidation of methionine-26 occurred with a 1:1 molar ratio of chloramine-T:methionine; at a 5:1 molar ratio, methionine-26 was almost completely oxidized, while methionine-24 was modified only 26%; at a 10:1 molar ratio, both methionines were completely oxidized. Each oxidized derivative demonstrated a lower toxicity toward T-cells than toward heart cells. Conversely, binding to heart cells was affected more than binding to T-cells. Cyanogen bromide cleaved native CTX at both methionines, excising phenyl-alanine-25 and methionine-26 and converting methionine-24 to homoserine lactone. This treatment of CTX eliminated cytotoxicity toward both heart and T-cells, but had only a modest effect upon T-cell binding, as had 50% oxidation of methionine-26, suggesting that CTX lytic and binding regions may be distinct. A selective loss in heart cell binding following oxidation of methionine-24 further suggests that different parts of CTX may interact with the two types of target cells. Perturbation of the relatively flat hydrophobic surface of the CTX' triple-stranded beta-sheet could result from the introduction of negative charge due to methionine-24 oxidation. Alternatively, amino acid side chain participation in a CTX binding domain may be altered by the potential formation of a new hydrogen bond between tyrosine-51 and methionine-24 sulfoxide, as revealed by computer modeling of the completely oxidized CTX derivative.

  20. Natural killer lytic-associated molecule plays a role in controlling tumor dissemination and metastasis

    Directory of Open Access Journals (Sweden)

    Richard Glenn Hoover

    2012-12-01

    Full Text Available Natural killer lytic-associated molecule (NKLAM is an E3 ubiquitin ligase that plays a major role in the cytolytic activity of NK cells. NKLAM is rapidly synthesized and then targeted to the granule membranes of NK cells upon NK activation. Previous studies have shown an essential role for NKLAM in NK killing activity in vitro. These findings were extended to an in vivo model of NK-mediated tumor killing in which NKLAM-deficient knockout (KO mice injected with B16 melanoma cells were found to have significantly higher numbers of pulmonary tumor nodules than wild type (WT mice. To further investigate the role of NKLAM and NK function in tumor immunity in vivo, we utilized additional tumor models to compare tumor development and progression in NKLAM KO and WT mice. Primary tumor growth, dissemination, and metastasis of RMA-S lymphoma cells and E0771 breast cancer cells were evaluated. Both tumor cell lines were stably transfected with constructs that allow expression of green fluorescent protein (GFP, which serves as a tumor-specific marker. Intravenous injection of NK-sensitive RMA-S lymphoma cells resulted in greater dissemination of lymphoma cells in NKLAM KO mice than in WT mice. Lymphoma cells were found in the lymph nodes and bone marrow of NKLAM KO mice two weeks after injection; few detectable tumor cells remained in WT mice. E0771 syngeneic breast cancer cells were injected into the mammary pads of NKLAM KO and WT mice. Primary tumor growth was greater in NKLAM KO than in WT mice. More significantly, there were four to five fold more tumor cells in the blood and lungs of NKLAM KO than in WT mice two weeks after injection of tumor cells into the mammary pad. These results indicate that NKLAM plays a role in tumor development in vivo, especially in controlling tumor dissemination and metastasis to distant sites.

  1. Analyzing Activities of Lytic Polysaccharide Monooxygenases by Liquid Chromatography and Mass Spectrometry.

    Science.gov (United States)

    Westereng, Bjørge; Arntzen, Magnus Ø; Agger, Jane Wittrup; Vaaje-Kolstad, Gustav; Eijsink, Vincent G H

    2017-01-01

    Lytic polysaccharide monooxygenases perform oxidative cleavage of glycosidic bonds in various polysaccharides. The majority of LMPOs studied so far possess activity on either cellulose or chitin and analysis of these activities is therefore the main focus of this review. Notably, however, the number of LPMOs that are active on other polysaccharides is increasing. The products generated by LPMOs from cellulose are either oxidized in the downstream end (at C1) or upstream end (at C4), or at both ends. These modifications only result in small structural changes, which makes both chromatographic separation and product identification by mass spectrometry challenging. The changes in physicochemical properties that are associated with oxidation need to be considered when choosing analytical approaches. C1 oxidation leads to a sugar that is no longer reducing but instead has an acidic functionality, whereas C4 oxidation leads to products that are inherently labile at high and low pH and that exist in a keto-gemdiol equilibrium that is strongly shifted toward the gemdiol in aqueous solutions. Partial degradation of C4-oxidized products leads to the formation of native products, which could explain why some authors claim to have observed glycoside hydrolase activity for LPMOs. Notably, apparent glycoside hydrolase activity may also be due to small amounts of contaminating glycoside hydrolases since these normally have much higher catalytic rates than LPMOs. The low catalytic turnover rates of LPMOs necessitate the use of sensitive product detection methods, which limits the analytical possibilities considerably. Modern liquid chromatography and mass spectrometry have become essential tools for evaluating LPMO activity, and this chapter provides an overview of available methods together with a few novel tools. The methods described constitute a suite of techniques for analyzing oxidized carbohydrate products, which can be applied to LPMOs as well as other carbohydrate

  2. Antibacterial efficacy of lytic bacteriophages against antibiotic-resistant Klebsiella species.

    Science.gov (United States)

    Karamoddini, M Khajeh; Fazli-Bazzaz, B S; Emamipour, F; Ghannad, M Sabouri; Jahanshahi, A R; Saed, N; Sahebkar, A

    2011-07-07

    Bacterial resistance to antibiotics is a leading and highly prevalent problem in the treatment of infectious diseases. Bacteriophages (phages) appear to be effective and safe alternatives for the treatment of resistant infections because of their specificity for bacterial species and lack of infectivity in eukaryotic cells. The present study aimed to isolate bacteriophages against Klebsiella spp. and evaluate their efficacy against antibiotic-resistant species. Seventy-two antibiotic-resistant Klebsiella spp. were isolated from samples of patients who referred to the Ghaem Hospital (Mashhad, Iran). Lytic bacteriophages against Klebsiella spp. were isolated from wastewater of the septic tank of the same hospital. Bactericidal activity of phages against resistant Klebsiella spp. was tested in both liquid (tube method; after 1 and 24 h of incubation) and solid (double-layer agar plate method; after 24 h of incubation) phases. In each method, three different concentrations of bacteriophages (low: 10(7) PFU/mL) were used. Bacteriophages showed promising bactericidal activity at all assessed concentrations, regardless of the test method and duration of incubation. Overall, bactericidal effects were augmented at higher concentrations. In the tube method, higher activity was observed after 24 h of incubation compared to the 1-h incubation. The bactericidal effects were also higher in the tube method compared to the double-layer agar plate method after 24 h of incubation. The findings of the present study suggest that bacteriophages possess effective bactericidal activity against resistant Klebsiella spp. These bactericidal activities are influenced by phage concentration, duration of incubation, and test method.

  3. In vitro model for lytic replication, latency, and transformation of an oncogenic alphaherpesvirus.

    Science.gov (United States)

    Schermuly, Julia; Greco, Annachiara; Härtle, Sonja; Osterrieder, Nikolaus; Kaufer, Benedikt B; Kaspers, Bernd

    2015-06-09

    Marek's disease virus (MDV) is an alphaherpesvirus that causes deadly T-cell lymphomas in chickens and serves as a natural small animal model for virus-induced tumor formation. In vivo, MDV lytically replicates in B cells that transfer the virus to T cells in which the virus establishes latency. MDV also malignantly transforms CD4+ T cells with a T(reg) signature, ultimately resulting in deadly lymphomas. No in vitro infection system for primary target cells of MDV has been available due to the short-lived nature of these cells in culture. Recently, we characterized cytokines and monoclonal antibodies that promote survival of cultured chicken B and T cells. We used these survival stimuli to establish a culture system that allows efficient infection of B and T cells with MDV. We were able to productively infect with MDV B cells isolated from spleen, bursa or blood cultured in the presence of soluble CD40L. Virus was readily transferred from infected B to T cells stimulated with an anti-TCRαVβ1 antibody, thus recapitulating the in vivo situation in the culture dish. Infected T cells could then be maintained in culture for at least 90 d in the absence of TCR stimulation, which allowed the establishment of MDV-transformed lymphoblastoid cell lines (LCL). The immortalized cells had a signature comparable to MDV-transformed CD4+ α/β T cells present in tumors. In summary, we have developed a novel in vitro system that precisely reflects the life cycle of an oncogenic herpesivrus in vivo and will allow us to investigate the interaction between virus and target cells in an easily accessible system.

  4. Antibacterial Efficacy of Lytic Bacteriophages against Antibiotic-Resistant Klebsiella Species

    Directory of Open Access Journals (Sweden)

    M. Khajeh Karamoddini

    2011-01-01

    Full Text Available Bacterial resistance to antibiotics is a leading and highly prevalent problem in the treatment of infectious diseases. Bacteriophages (phages appear to be effective and safe alternatives for the treatment of resistant infections because of their specificity for bacterial species and lack of infectivity in eukaryotic cells. The present study aimed to isolate bacteriophages against Klebsiella spp. and evaluate their efficacy against antibiotic-resistant species. Seventy-two antibiotic-resistant Klebsiella spp. were isolated from samples of patients who referred to the Ghaem Hospital (Mashhad, Iran. Lytic bacteriophages against Klebsiella spp. were isolated from wastewater of the septic tank of the same hospital. Bactericidal activity of phages against resistant Klebsiella spp. was tested in both liquid (tube method; after 1 and 24 h of incubation and solid (double-layer agar plate method; after 24 h of incubation phases. In each method, three different concentrations of bacteriophages (low: 107 PFU/mL were used. Bacteriophages showed promising bactericidal activity at all assessed concentrations, regardless of the test method and duration of incubation. Overall, bactericidal effects were augmented at higher concentrations. In the tube method, higher activity was observed after 24 h of incubation compared to the 1-h incubation. The bactericidal effects were also higher in the tube method compared to the double-layer agar plate method after 24 h of incubation. The findings of the present study suggest that bacteriophages possess effective bactericidal activity against resistant Klebsiella spp. These bactericidal activities are influenced by phage concentration, duration of incubation, and test method.

  5. Cyclin-dependent kinase activity controls the onset of the HCMV lytic cycle.

    Directory of Open Access Journals (Sweden)

    Martin Zydek

    Full Text Available The onset of human cytomegalovirus (HCMV lytic infection is strictly synchronized with the host cell cycle. Infected G0/G1 cells support viral immediate early (IE gene expression and proceed to the G1/S boundary where they finally arrest. In contrast, S/G2 cells can be infected but effectively block IE gene expression and this inhibition is not relieved until host cells have divided and reentered G1. During latent infection IE gene expression is also inhibited, and for reactivation to occur this block to IE gene expression must be overcome. It is only poorly understood which viral and/or cellular activities maintain the block to cell cycle or latency-associated viral IE gene repression and whether the two mechanisms may be linked. Here, we show that the block to IE gene expression during S and G2 phase can be overcome by both genotoxic stress and chemical inhibitors of cellular DNA replication, pointing to the involvement of checkpoint-dependent signaling pathways in controlling IE gene repression. Checkpoint-dependent rescue of IE expression strictly requires p53 and in the absence of checkpoint activation is mimicked by proteasomal inhibition in a p53 dependent manner. Requirement for the cyclin dependent kinase (CDK inhibitor p21 downstream of p53 suggests a pivotal role for CDKs in controlling IE gene repression in S/G2 and treatment of S/G2 cells with the CDK inhibitor roscovitine alleviates IE repression independently of p53. Importantly, CDK inhibiton also overcomes the block to IE expression during quiescent infection of NTera2 (NT2 cells. Thus, a timely block to CDK activity not only secures phase specificity of the cell cycle dependent HCMV IE gene expression program, but in addition plays a hitherto unrecognized role in preventing the establishment of a latent-like state.

  6. Lytic effects of normal serum on isolated postonchospheral and metacestode stages of Taenia taeniaeformis.

    Science.gov (United States)

    Conder, G A; Picone, J; Geary, A M; deHoog, J; Williams, J F

    1983-06-01

    Postonchospheral stages of Taenia taeniaeformis liberated from rat livers by enzymatic digestion at 1 to 10 days postinfection (DPI) and metacestodes dissected from infected livers at 22, 34, and 69 DPI were exposed in vitro to immune rat serum (IRS) and to normal serum from rats (NRS), human beings (NHS), or guinea pigs (NGS). The onset of rapid and destructive tegumental changes in all organisms exposed to any of the sera was demonstrated to be complement-dependent because the reaction was: (a) inhibited by treatment of serum at 56 C for 30 min; (b) inhibited by prior incubation of serum with zymosan or with complement-fixing, soluble products derived from larvae of T. taeniaeformis maintained in vitro (IVP); and (c) abolished by the addition of EDTA. Lytic effects occurred on exposure to agammaglobulinemic sheep serum, and lysis in the presence of IRS and NRS was shown to result in consumption of available hemolytic complement. Surface changes consisted of vesiculation in the microvillar or microthrix layers followed by sloughing of the tegument, eventually leading to collapse of the cystic bladder and cessation of flame cell activity, or, in the case of early postonchospheral forms, complete disintegration of the organism. When IVP was added to NHS, reduction of hemolytic complement activity was associated with the electrophoretic conversion of C3, and Factor B, but there was little or no consumption of C1. The observations support the hypothesis that complement-mediated effector mechanisms must be counteracted to ensure survival of parasites in vivo, and that the capacity for release of soluble nonspecific complement-fixing factors by taeniid larvae may have an important role to play in this process.

  7. Combating Antimicrobial Resistance in Foodborne Microorganisms.

    Science.gov (United States)

    Lai, Edward P C; Iqbal, Zafar; Avis, Tyler J

    2016-02-01

    This review addresses an important public health hazard affecting food safety. Antimicrobial agents are used in foods to reduce or eliminate microorganisms that cause disease. Many traditional organic compounds, novel synthetic organic agents, natural products, peptides, and proteins have been extensively studied for their effectiveness as antimicrobial agents against foodborne Campylobacter spp., Escherichia coli, Listeria spp. and Salmonella. However, antimicrobial resistance can develop in microorganisms, enhancing their ability to withstand the inhibiting or killing action of antimicrobial agents. Knowledge gaps still exist with regard to the actual chemical and microbiological mechanisms that must be identified to facilitate the search for new antimicrobial agents. Technical implementation of antimicrobial active packing films and coatings against target microorganisms must also be improved for extended product shelf life. Recent advances in antimicrobial susceptibility testing can provide researchers with new momentum to pursue their quest for a resistance panacea.

  8. Recovery of germanium from lignite by microorganism

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The recovery of Ge from lignite by microorganism includes two stages: (1) the breaking-down of Ge complex of humus in lignite into simple compounds assisted by microorganism; (2) the desorption of Ge compounds from the lignite. The recovery rate of Ge has been enhanced by 14% since the discovery of adsorption and desorption of Ge from coal. The effects of pH, leaching agents, and coal size on the recovery of Ge were experimentally investigated, and the optimized process parameters were obtained. The reaction heat of Ge adsorption and desorption in lignite was determined. It is about 23-53 kJ/mol, which reveals that the adsorption belongs to physical process. The recovery rate of Ge from lignite with direct microorganism leaching can reach about 85%, which is higher than that of 60% reported elsewhere. A potential process for leaching Ge in lignite was suggested.

  9. Selective enumeration of probiotic microorganisms in cheese.

    Science.gov (United States)

    Karimi, Reza; Mortazavian, Amir M; Amiri-Rigi, Atefeh

    2012-02-01

    Cheese is a dairy product which has a good potential for delivery of probiotic microorganisms into the human intestine. To be considered to offer probiotic health benefits, probiotics must remain viable in food products above a threshold level (e.g., 10(6) cfu g(-1)) until the time of consumption. In order to ensure that a minimal number of probiotic bacteria is present in the cheese, reliable methods for enumeration are required. The choice of culture medium for selective enumeration of probiotic strains in combination with starters depends on the product matrix, the target group and the taxonomic diversity of the bacterial background flora in the product. Enumeration protocol should be designed as a function of the target microorganism(s) to be quantified in the cheese. An overview of some series of culture media for selective enumeration of commercial probiotic cultures is presented in this review.

  10. Microorganism Utilization for Synthetic Milk Production

    Science.gov (United States)

    Birmele, Michele; Morford, Megan; Khodadad, Christina; Spencer, Lashelle; Richards, Jeffrey; Strayer, Richard; Caro, Janicce; Hummerick, Mary; Wheeler, Ray

    2014-01-01

    A desired architecture for long duration spaceflight, such as aboard the International Space Station (ISS) or for future missions to Mars, is to provide a supply of fresh food crops for the astronauts. However, some crops can create a high proportion of inedible plant waste. The main goal of this project was to produce the components of milk (sugar, lipid, protein) from inedible plant waste by utilizing microorganisms (fungi, yeast, bacteria). Of particular interest was utilizing the valuable polysaccharide, cellulose, found in plant waste, to naturally fuel- through microorganism cellular metabolism- the creation of sugar (glucose), lipid (milk fat), and protein (casein) to produce a synthetic edible food product. Environmental conditions such as pH, temperature, carbon source, aeration, and choice microorganisms.

  11. Biosurfactants, bioemulsifiers and exopolysaccharides from marine microorganisms.

    Science.gov (United States)

    Satpute, Surekha K; Banat, Ibrahim M; Dhakephalkar, Prashant K; Banpurkar, Arun G; Chopade, Balu A

    2010-01-01

    Marine biosphere offers wealthy flora and fauna, which represents a vast natural resource of imperative functional commercial grade products. Among the various bioactive compounds, biosurfactant (BS)/bioemulsifiers (BE) are attracting major interest and attention due to their structural and functional diversity. The versatile properties of surface active molecules find numerous applications in various industries. Marine microorganisms such as Acinetobacter, Arthrobacter, Pseudomonas, Halomonas, Myroides, Corynebacteria, Bacillus, Alteromonas sp. have been studied for production of BS/BE and exopolysaccharides (EPS). Due to the enormity of marine biosphere, most of the marine microbial world remains unexplored. The discovery of potent BS/BE producing marine microorganism would enhance the use of environmental biodegradable surface active molecule and hopefully reduce total dependence or number of new application oriented towards the chemical synthetic surfactant industry. Our present review gives comprehensive information on BS/BE which has been reported to be produced by marine microorganisms and their possible potential future applications.

  12. Functional Properties of Microorganisms in Fermented Foods

    Directory of Open Access Journals (Sweden)

    Jyoti Prakash Tamang

    2016-04-01

    Full Text Available Fermented foods have unique functional properties imparting some health benefits to consumers due to presence of functional microorganisms, which possess probiotics properties, antimicrobial, antioxidant, peptide production, etc. Health benefits of some global fermented foods are synthesis of nutrients, prevention of cardiovascular disease, prevention of cancer, gastrointestinal disorders, allergic reactions, diabetes, among others. The present paper is aimed to review the information on some functional properties of the microorganisms associated with fermented foods and beverages, and their health-promoting benefits to consumers.

  13. Risk Assessment of Genetically Modified Microorganisms

    DEFF Research Database (Denmark)

    Jacobsen, B. L.; Wilcks, Andrea

    2001-01-01

    the industry, national administration and research institutions were gathered to discuss which elements should be considered in a risk assessment of genetically modified microorganisms used as food or food ingredients. The existing EU and national regulations were presented, together with the experiences......The rapid development of recombinant DNA techniques for food organisms urges for an ongoing discussion on the risk assessment of both new as traditional use of microorganisms in food production. This report, supported by the Nordic Council of Ministers, is the result of a workshop where people from...

  14. [Metagenomics in studying gastrointestinal tract microorganism].

    Science.gov (United States)

    Xu, Bo; Yang, Yunjuan; Li, Junjun; Tang, Xianghua; Mu, Yuelin; Huang, Zunxi

    2013-12-01

    Animal gastrointestinal tract contains a complex community of microbes, whose composition ultimately reflects the co-evolution of microorganisms with their animal host. The gut microbial community of humans and animals has received significant attention from researchers because of its association with health and disease. The application of metagenomics technology enables researchers to study not only the microbial composition but also the function of microbes in the gastrointestinal tract. In this paper, combined with our own findings, we summarized advances in studying gastrointestinal tract microorganism with metagenomics and the bioinformatics technology.

  15. Genome wide nucleosome mapping for HSV-1 shows nucleosomes are deposited at preferred positions during lytic infection.

    Science.gov (United States)

    Oh, Jaewook; Sanders, Iryna F; Chen, Eric Z; Li, Hongzhe; Tobias, John W; Isett, R Benjamin; Penubarthi, Sindura; Sun, Hao; Baldwin, Don A; Fraser, Nigel W

    2015-01-01

    HSV is a large double stranded DNA virus, capable of causing a variety of diseases from the common cold sore to devastating encephalitis. Although DNA within the HSV virion does not contain any histone protein, within 1 h of infecting a cell and entering its nucleus the viral genome acquires some histone protein (nucleosomes). During lytic infection, partial micrococcal nuclease (MNase) digestion does not give the classic ladder band pattern, seen on digestion of cell DNA or latent viral DNA. However, complete digestion does give a mono-nucleosome band, strongly suggesting that there are some nucleosomes present on the viral genome during the lytic infection, but that they are not evenly positioned, with a 200 bp repeat pattern, like cell DNA. Where then are the nucleosomes positioned? Here we perform HSV-1 genome wide nucleosome mapping, at a time when viral replication is in full swing (6 hr PI), using a microarray consisting of 50mer oligonucleotides, covering the whole viral genome (152 kb). Arrays were probed with MNase-protected fragments of DNA from infected cells. Cells were not treated with crosslinking agents, thus we are only mapping tightly bound nucleosomes. The data show that nucleosome deposition is not random. The distribution of signal on the arrays suggest that nucleosomes are located at preferred positions on the genome, and that there are some positions that are not occupied (nucleosome free regions -NFR or Nucleosome depleted regions -NDR), or occupied at frequency below our limit of detection in the population of genomes. Occupancy of only a fraction of the possible sites may explain the lack of a typical MNase partial digestion band ladder pattern for HSV DNA during lytic infection. On average, DNA encoding Immediate Early (IE), Early (E) and Late (L) genes appear to have a similar density of nucleosomes.

  16. Prospective study of the clinical performance of three BACTEC media in a modern emergency department: Plus Aerobic/F, Plus Anaerobic/F, and Anaerobic Lytic/F.

    Science.gov (United States)

    Rocchetti, Andrea; Di Matteo, Luigi; Bottino, Paolo; Foret, Benjamin; Gamalero, Elisa; Calabresi, Alessandra; Guido, Gianluca; Casagranda, Ivo

    2016-11-01

    The performance of 3 blood culture bottles (BACTEC Plus Aerobic/F, Plus Anaerobic/F, and Anaerobic Lytic/F) were analyzed with clinical specimens collected from 688 Emergency Department patients. A total of 270 strains belonging to 33 species were identified, with E. coli and S. aureus as the most frequently detected. Overall recovery rate (RR) of bacteria and yeast was equivalent in the Plus Aerobic/F vials (208 of 270 isolates; 77.0%) and Anaerobic Lytic/F vials (206 isolates; 76.3%) and significantly better than in the Plus Anaerobic/F vials (189 isolates; 70.0%). Median time to detection (TTD) was earliest with the Anaerobic Lytic/F vials (12.0h) compared with the Plus Aerobic/F (14.6h) and Plus Anaerobic/F vials (15.4h). Positivity rate (PR) was similar for Anaerobic Lytic/F vials (76.9%) and Plus Aerobic/F vials (76.5%), but better if compared with Plus Anaerobic/F vials (69.4%). The PR and TTD for the combination of Plus Aerobic/F with Anaerobic Lytic/F (94.5% and 12.3h, respectively) was significantly better than with Plus Aerobic/F with Plus Anaerobic/F (87.8% and 14.1h).

  17. The phage lytic proteins from the Staphylococcus aureus bacteriophage vB_SauS-phiIPLA88 display multiple active catalytic domains and do not trigger staphylococcal resistance.

    Directory of Open Access Journals (Sweden)

    Lorena Rodríguez-Rubio

    Full Text Available The increase in antibiotic resistance world-wide revitalized the interest in the use of phage lysins to combat pathogenic bacteria. In this work, we analyzed the specific cleavage sites on the staphylococcal peptidoglycan produced by three phage lytic proteins. The investigated cell wall lytic enzymes were the endolysin LysH5 derived from the S. aureus bacteriophage vB_SauS-phi-IPLA88 (phi-IPLA88 and two fusion proteins between lysostaphin and the virion-associated peptidoglycan hydrolase HydH5 (HydH5SH3b and HydH5Lyso. We determined that all catalytic domains present in these proteins were active. Additionally, we tested for the emergence of resistant Staphylococcus aureus to any of the three phage lytic proteins constructs. Resistant S. aureus could not be identified after 10 cycles of bacterial exposure to phage lytic proteins either in liquid or plate cultures. However, a quick increase in lysostaphin resistance (up to 1000-fold in liquid culture was observed. The lack of resistant development supports the use of phage lytic proteins as future therapeutics to treat staphylococcal infections.

  18. Inhibition of p38 MAP kinase pathway induces apoptosis and prevents Epstein Barr virus reactivation in Raji cells exposed to lytic cycle inducing compounds

    Directory of Open Access Journals (Sweden)

    Di Renzo Livia

    2009-03-01

    Full Text Available Abstract Background EBV lytic cycle activators, such as phorbol esters, anti-immunoglobulin, transforming growth factor β (TGFβ, sodium butyrate, induce apoptosis in EBV-negative but not in EBV-positive Burkitt's lymphoma (BL cells. To investigate the molecular mechanisms allowing EBV-infected cells to be protected, we examined the expression of viral and cellular antiapoptotic proteins as well as the activation of signal transduction pathways in BL-derived Raji cells exposed to lytic cycle inducing agents. Results Our data show that, following EBV activation, the latent membrane protein 1 (LMP1 and the cellular anti-apoptotic proteins MCL-1 and BCL-2 were quickly up-regulated and that Raji cells remained viable even when exposed simultaneously to P(BU2, sodium butyrate and TGFβ. We report here that inhibition of p38 pathway, during EBV activation, led to a three fold increment of apoptosis and largely prevented lytic gene expression. Conclusion These findings indicate that, during the switch from the latent to the lytic phase of EBV infection, p38 MAPK phosphorylation plays a key role both for protecting the host cells from apoptosis as well as for inducing viral reactivation. Because Raji cells are defective for late antigens expression, we hypothesize that the increment of LMP1 gene expression in the early phases of EBV lytic cycle might contribute to the survival of the EBV-positive cells.

  19. Rare presentation of pediatric acute promyelocytic leukemia as multiple lytic bone lesions: Case report and review of literature

    Directory of Open Access Journals (Sweden)

    Manjusha Nair

    2014-01-01

    Full Text Available Acute promyelocytic leukemia (APL is an uncommon malignancy in the pediatric population, accounting for only 5-10% of pediatric acute myeloid leukemias, and for this disease to present with bone lesions at diagnosis is extremely unusual. We wish to convey that very rarely, in a pediatric cancer patient presenting with multiple extensive lytic bone lesions, the diagnosis can be APL. The treatment protocol and prognostic implications are vastly different. Histopathology is the gold standard in arriving at a correct diagnosis and delivering proper treatment in such cases. This patient had excellent response to chemotherapy.

  20. Cello-Oligosaccharide Oxidation Reveals Differences between Two Lytic Polysaccharide Monooxygenases (Family GH61) from Podospora anserina

    OpenAIRE

    Bey, Mathieu; Zhou, Simeng; Poidevin, Laetitia; Henrissat, Bernard; Coutinho, Pedro M.; Berrin, Jean-Guy; Sigoillot, Jean-Claude

    2013-01-01

    The genome of the coprophilic ascomycete Podospora anserina encodes 33 different genes encoding copper-dependent lytic polysaccharide monooxygenases (LPMOs) from glycoside hydrolase family 61 (GH61). In this study, two of these enzymes (P. anserina GH61A [PaGH61A] and PaGH61B), which both harbored a family 1 carbohydrate binding module, were successfully produced in Pichia pastoris. Synergistic cooperation between PaGH61A or PaGH61B with the cellobiose dehydrogenase (CDH) of Pycnoporus cinnab...

  1. Primary intraosseous atypical inflammatory meningioma presenting as a lytic skull lesion: Case report with review of literature

    Directory of Open Access Journals (Sweden)

    Sangita Bohara

    2016-01-01

    Full Text Available Primary extradural meningiomas of the skull comprise 1% of all meningiomas, and lytic skull meningiomas are still rarer and are said to be more aggressive. We present a case of 38-year-old male with an extradural tumor which on histopathological examination showed features of inflammatory atypical meningioma (WHO Grade II. The intense inflammatory nature of osteolytic primary intraosseous meningioma has not been reported before. This entity deserves special mention because of the need for adjuvant therapy and proper follow-up.

  2. Modelling the morphology of filamentous microorganisms

    DEFF Research Database (Denmark)

    Nielsen, Jens Bredal

    1996-01-01

    The rapid development in image analysis techniques has made it possible to study the growth kinetics of filamentous microorganisms in more detail than previously, However, owing to the many different processes that influence the morphology it is important to apply mathematical models to extract...

  3. Food fermentations: Microorganisms with technological beneficial use

    DEFF Research Database (Denmark)

    Bourdichon, François; Casaregola, Serge; Farrokh, Choreh

    2012-01-01

    Microbial food cultures have directly or indirectly come under various regulatory frameworks in the course of the last decades. Several of those regulatory frameworks put emphasis on “the history of use”, “traditional food”, or “general recognition of safety”. Authoritative lists of microorganisms...

  4. Engineered microorganisms having resistance to ionic liquids

    Science.gov (United States)

    Ruegg, Thomas Lawrence; Thelen, Michael P.

    2016-03-22

    The present invention provides for a method of genetically modifying microorganisms to enhance resistance to ionic liquids, host cells genetically modified in accordance with the methods, and methods of using the host cells in a reaction comprising biomass that has been pretreated with ionic liquids.

  5. Ecophysiology of microorganisms in microbial elctrolysis cells

    NARCIS (Netherlands)

    Croese, E.

    2012-01-01

    One of the main challenges for improvement of the microbial electrolysis cell (MEC) has been the reduction of the cost of the cathode catalyst. As catalyst at the cathode, microorganisms offer great possibilities. Previous research has shown the principle possibilities for the biocathode for H2

  6. Microorganisms as Indicators of Soil Health

    DEFF Research Database (Denmark)

    Nielsen, M. N.; Winding, A.; Binnerup, S.;

    Microorganisms are an essential part of living soil and of outmost importance for soil health. As such they can be used as indicators of soil health. This report reviews the current and potential future use of microbial indicators of soil health and recommends specific microbial indicators for soil...... indicators into soil monitoring programmes as they become applicable....

  7. Pesticides in Soil: Effects on Microorganisms

    Directory of Open Access Journals (Sweden)

    Ljiljana Radivojević

    2007-01-01

    Full Text Available Since their discovery to the present day, pesticides have been an inevitable segment of agricultural production and efforts have been made to synthesize compounds that would share a required efficacy along with selectivity, sufficient persistence on the object of protection and favourable toxicological and ecotoxicological characteristics so as to minimize their effect on the environment.When a pesticide gets into soil after application, it takes part in a number of physical, chemical and biological processes that depend not only on the compound itself, but a number of other factors as well, such as: physical, chemical and biological characteristics of soil; climatic factors, equipment used, method of application, method of storage, handling and disposal of waste, site characteristics (proximity of ground and underground waters, biodiversity and sensitivity of the environment. Microorganisms play an important role in pesticide degradation as they are able to utilize the biogenic elements from those compounds, as well as energy for their physiological processes. On the other hand, pesticides are more or less toxic substances that can have adverse effect on populations of microorganisms and prevent their development, reduce their abundance, deplete their taxonomic complexity and create communities with a lower level of diversity and reduced physiological activity.The article discusses complex interactions between pesticides and microorganisms in soil immediately after application and over the ensuing period. Data on changes in the abundance of some systematic and physiological groups of microorganisms, their microbial biomass and enzymatic activity caused under pesticide activity are discussed as indicators of these processes.

  8. 40 CFR 725.85 - Microorganism identity.

    Science.gov (United States)

    2010-07-01

    ... information confidential in a TERA submission and wishes the same information to remain confidential in a subsequent TERA or MCAN submission, the person must reassert and resubstantiate the claim in the subsequent... under paragraph (a) of this section in any TERA submitted for the microorganism, but subsequently...

  9. Ecophysiology of microorganisms in microbial elctrolysis cells

    NARCIS (Netherlands)

    Croese, E.

    2012-01-01

    One of the main challenges for improvement of the microbial electrolysis cell (MEC) has been the reduction of the cost of the cathode catalyst. As catalyst at the cathode, microorganisms offer great possibilities. Previous research has shown the principle possibilities for the biocathode for H2 prod

  10. Attaching substances to micro-organisms

    NARCIS (Netherlands)

    Buist, Girbe; Leenhouts, Cornelis Johannes; Venema, Gerard; Kok, Jan

    1999-01-01

    The invention relates to surface display of proteins on micro-organisms via the targeting and anchoring of heterologous proteins to the outer surface of cells such as yeast, fungi, mammalian and plant cells, and bacteria. The invention provides a proteinaceous substance comprising a reactive group a

  11. Novel Industrial Enzymes from Uncultured Arctic Microorganisms

    DEFF Research Database (Denmark)

    Vester, Jan Kjølhede

    on the diversity of microorganisms from the ikaite columns as well as bioprospecting for enzyme activities using both culture dependent and independent methods. Two cold-active β-galactosidases and one extremely cold-active α-amylase, all related to Clostridia, were characterized in more details....

  12. Radiation sensitivity of hyperthermal composting microorganisms

    Science.gov (United States)

    Choi, Jong-Il; Yoon, Min-Chul; Kim, Jae-Hun; Yamashita, Masamichi; Kim, Geun Joong; Lee, Ju-Woon

    In the space station and vehicles designed for long human mission, high-temperature compost is a promising technology for decomposing organic waste and producing the fertilizers. In space, the microorganisms could have the changed biological activities or even be mutated by ionizing irradiation. Therefore, in this study, the effect of gamma irradiation on the sensitivity of bacteria in hyperthermal composting was investigated. The sequence analysis of the amplified 16s rDNA genes and amoA gene were used for the identification of composting microorganisms. Viability of microorganisms in compost soil after gamma irradiation was directly visualized with LIVE/DEAD Baclight viability kit. The dominant bacterial genera are Weissella cibaria and Leuconostoc sp. and fungus genera are Metschnikowia bicuspidate and Pichia guilliermondii, respectively. By the gamma irradiation up to the dose of 1 kGy, the microbial population was not changed. Also, the enzyme activities of amylase and cellulose were sustained by the gamma irradiation. These results show that these hyperthermia microorganisms might have the high resistance to gamma radiation and could be used for agriculture in the Space Station.

  13. Airborne microorganisms and dust from livestock houses

    NARCIS (Netherlands)

    Zhao, Y.; Aarnink, A.J.A.; Jong, de M.C.M.; Groot Koerkamp, P.W.G.

    2011-01-01

    The objective of this study was to evaluate the efficiencies and suitability of samplers for airborne microorganisms and dust, which could be used in practical livestock houses. Two studies were performed: 1) Testing impaction and cyclone pre-separators for dust sampling in livestock houses; 2) Dete

  14. Biodiversity of deep-sea microorganisms

    Directory of Open Access Journals (Sweden)

    Fengping Wang

    2013-07-01

    Full Text Available The oceans, with an average depth of 3,800 meters and an average pressure about 38 MPa, cover about 70% of the surface of the Earth. Geological structures under the seawater, such as marine sediments, oceanic crust, hydrothermal vents, and the cold seeps, vary significantly with regard to physical and chemical properties. In combination, these diverse environments contain the largest microbial ecosystem in the world. In deep seawater, the major microorganism groups are Alpha-& Gammaproteobacteria, and Marine Group I. In deep-sea sediments, the abundance of microbes is related to the content of organic matter and distance from land. Methane Oxidizing Archaea (ANME and sulfate reducing bacteria (Deltaproteobacteria are common in deep-sea cold seep environments; while in hydrothermal vents, the richness and dynamics of chemical substances have led to highly diversified archaeal and bacterial groups. In contrast, the oceanic crust is mainly composed of basic and ultrabasic rocks rich in minerals, and as a result houses microorganisms that are mainly autotrophic, utilizing iron, manganese and sulfur. Because more than 99% of deep-sea microorganisms cannot be cultured, an understanding of their diversity, physiological features, and biogeochemical roles remains to be fully achieved. In this article, we review and summarize what is known about the distribution and diversity of deep-sea microorganisms in diverse habitats. It is emphasized that there is much to learn about these microbes.

  15. Artifical Microorganism Infection in Aviation Kerosene

    Directory of Open Access Journals (Sweden)

    Dušan Vallo

    2004-12-01

    Full Text Available The fuel used in the aviation engineering has to be clean and dry, it may not contain mechanical impurities and water. Water inaviation kerosene may occur in soluble and insoluble form. The danger inheres in the insoluble form, which may drop out in the crystallineform and cause various failures, such as those caused by mechanical impurities. The water assists in the biological matter formation createdby various species of microorganisms (bacteria, mould fungi and yeast. The microorganisms, present in water phase occurring on thebottom of tanks or on the interface water phase – kerosene, grow and reproduce and subsequently may pollute (impair the fuel by thebiomass or by the products of their metabolism. There is a possibility to infect the fuel artificially by a selected reference microorganismstrain, which usually occur in contaminated fuel, or by microorganisms which cause a biological contamination of aviation kerosene.Out of the selected reference strains used in the experiments, the reference strains of Proteus vulgaris, Sacharamyces cerevisiae andClostridium perfringens were not cultivated in the sterile aviation kerosene and the propagating nutrient medium. The aviation kerosene actsas a biocide medium for the presented reference microorganism strains.

  16. How Microorganisms Affect Food Safety and Quality

    OpenAIRE

    Bacon, Karleigh

    2012-01-01

    The main methods of preservation for shelf-stable foods are controlling the water activity or lowering the pH. Factors are often combined, like lowering pH AND using refrigeration. Understanding how food supports the growth of microorganisms can help improve both food safety AND food quality. This guide can help you manipulate your food to create a safe product.

  17. Abortive lytic reactivation of KSHV in CBF1/CSL deficient human B cell lines.

    Directory of Open Access Journals (Sweden)

    Barbara A Scholz

    Full Text Available Since Kaposi's sarcoma associated herpesvirus (KSHV establishes a persistent infection in human B cells, B cells are a critical compartment for viral pathogenesis. RTA, the replication and transcription activator of KSHV, can either directly bind to DNA or use cellular DNA binding factors including CBF1/CSL as DNA adaptors. In addition, the viral factors LANA1 and vIRF4 are known to bind to CBF1/CSL and modulate RTA activity. To analyze the contribution of CBF1/CSL to reactivation in human B cells, we have successfully infected DG75 and DG75 CBF1/CSL knock-out cell lines with recombinant KSHV.219 and selected for viral maintenance by selective medium. Both lines maintained the virus irrespective of their CBF1/CSL status. Viral reactivation could be initiated in both B cell lines but viral genome replication was attenuated in CBF1/CSL deficient lines, which also failed to produce detectable levels of infectious virus. Induction of immediate early, early and late viral genes was impaired in CBF1/CSL deficient cells at multiple stages of the reactivation process but could be restored to wild-type levels by reintroduction of CBF1/CSL. To identify additional viral RTA target genes, which are directly controlled by CBF1/CSL, we analyzed promoters of a selected subset of viral genes. We show that the induction of the late viral genes ORF29a and ORF65 by RTA is strongly enhanced by CBF1/CSL. Orthologs of ORF29a in other herpesviruses are part of the terminase complex required for viral packaging. ORF65 encodes the small capsid protein essential for capsid shell assembly. Our study demonstrates for the first time that in human B cells viral replication can be initiated in the absence of CBF1/CSL but the reactivation process is severely attenuated at all stages and does not lead to virion production. Thus, CBF1/CSL acts as a global hub which is used by the virus to coordinate the lytic cascade.

  18. Imprinting of Microorganisms for Biosensor Applications

    Science.gov (United States)

    Idil, Neslihan; Mattiasson, Bo

    2017-01-01

    There is a growing need for selective recognition of microorganisms in complex samples due to the rapidly emerging importance of detecting them in various matrices. Most of the conventional methods used to identify microorganisms are time-consuming, laborious and expensive. In recent years, many efforts have been put forth to develop alternative methods for the detection of microorganisms. These methods include use of various components such as silica nanoparticles, microfluidics, liquid crystals, carbon nanotubes which could be integrated with sensor technology in order to detect microorganisms. In many of these publications antibodies were used as recognition elements by means of specific interactions between the target cell and the binding site of the antibody for the purpose of cell recognition and detection. Even though natural antibodies have high selectivity and sensitivity, they have limited stability and tend to denature in conditions outside the physiological range. Among different approaches, biomimetic materials having superior properties have been used in creating artificial systems. Molecular imprinting is a well suited technique serving the purpose to develop highly selective sensing devices. Molecularly imprinted polymers defined as artificial recognition elements are of growing interest for applications in several sectors of life science involving the investigations on detecting molecules of specific interest. These polymers have attractive properties such as high bio-recognition capability, mechanical and chemical stability, easy preparation and low cost which make them superior over natural recognition reagents. This review summarizes the recent advances in the detection and quantification of microorganisms by emphasizing the molecular imprinting technology and its applications in the development of sensor strategies. PMID:28353629

  19. Genomic analysis of Bacillus subtilis lytic bacteriophage ϕNIT1 capable of obstructing natto fermentation carrying genes for the capsule-lytic soluble enzymes poly-γ-glutamate hydrolase and levanase.

    Science.gov (United States)

    Ozaki, Tatsuro; Abe, Naoki; Kimura, Keitarou; Suzuki, Atsuto; Kaneko, Jun

    2017-01-01

    Bacillus subtilis strains including the fermented soybean (natto) starter produce capsular polymers consisting of poly-γ-glutamate and levan. Capsular polymers may protect the cells from phage infection. However, bacteriophage ϕNIT1 carries a γ-PGA hydrolase gene (pghP) that help it to counteract the host cell's protection strategy. ϕNIT had a linear double stranded DNA genome of 155,631-bp with a terminal redundancy of 5,103-bp, containing a gene encoding an active levan hydrolase. These capsule-lytic enzyme genes were located in the possible foreign gene cluster regions between central core and terminal redundant regions, and were expressed at the late phase of the phage lytic cycle. All tested natto origin Spounavirinae phages carried both genes for capsule degrading enzymes similar to ϕNIT1. A comparative genomic analysis revealed the diversity among ϕNIT1 and Bacillus phages carrying pghP-like and levan-hydrolase genes, and provides novel understanding on the acquisition mechanism of these enzymatic genes.

  20. Recombinant microorganisms for increased production of organic acids

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Jian; Kleff, Susanne; Guettler, Michael V

    2013-04-30

    Disclosed are recombinant microorganisms for producing organic acids. The recombinant microorganisms express a polypeptide that has the enzymatic activity of an enzyme that is utilized in the pentose phosphate cycle. The recombinant microorganism may include recombinant Actinobacillus succinogenes that has been transformed to express a Zwischenferment (Zwf) gene. The recombinant microorganisms may be useful in fermentation processes for producing organic acids such as succinic acid and lactic acid. Also disclosed are novel plasmids that are useful for transforming microorganisms to produce recombinant microorganisms that express enzymes such as Zwf.

  1. An Epstein-Barr Virus (EBV) mutant with enhanced BZLF1 expression causes lymphomas with abortive lytic EBV infection in a humanized mouse model.

    Science.gov (United States)

    Ma, Shi-Dong; Yu, Xianming; Mertz, Janet E; Gumperz, Jenny E; Reinheim, Erik; Zhou, Ying; Tang, Weihua; Burlingham, William J; Gulley, Margaret L; Kenney, Shannon C

    2012-08-01

    Immunosuppressed patients are at risk for developing Epstein-Barr Virus (EBV)-positive lymphomas that express the major EBV oncoprotein, LMP1. Although increasing evidence suggests that a small number of lytically infected cells may promote EBV-positive lymphomas, the impact of enhanced lytic gene expression on the ability of EBV to induce lymphomas is unclear. Here we have used immune-deficient mice, engrafted with human fetal hematopoietic stem cells and thymus and liver tissue, to compare lymphoma formation following infection with wild-type (WT) EBV versus infection with a "superlytic" (SL) mutant with enhanced BZLF1 (Z) expression. The same proportions (2/6) of the WT and SL virus-infected animals developed B-cell lymphomas by day 60 postinfection; the remainder of the animals had persistent tumor-free viral latency. In contrast, all WT and SL virus-infected animals treated with the OKT3 anti-CD3 antibody (which inhibits T-cell function) developed lymphomas by day 29. Lymphomas in OKT3-treated animals (in contrast to lymphomas in the untreated animals) contained many LMP1-expressing cells. The SL virus-infected lymphomas in both OKT3-treated and untreated animals contained many more Z-expressing cells (up to 30%) than the WT virus-infected lymphomas, but did not express late viral proteins and thus had an abortive lytic form of EBV infection. LMP1 and BMRF1 (an early lytic viral protein) were never coexpressed in the same cell, suggesting that LMP1 expression is incompatible with lytic viral reactivation. These results show that the SL mutant induces an "abortive" lytic infection in humanized mice that is compatible with continued cell growth and at least partially resistant to T-cell killing.

  2. De Novo Herpes Simplex Virus VP16 Expression Gates a Dynamic Programmatic Transition and Sets the Latent/Lytic Balance during Acute Infection in Trigeminal Ganglia.

    Science.gov (United States)

    Sawtell, Nancy M; Thompson, Richard L

    2016-09-01

    The life long relationship between herpes simplex virus and its host hinges on the ability of the virus to aggressively replicate in epithelial cells at the site of infection and transport into the nervous system through axons innervating the infection site. Interaction between the virus and the sensory neuron represents a pivot point where largely unknown mechanisms lead to a latent or a lytic infection in the neuron. Regulation at this pivot point is critical for balancing two objectives, efficient widespread seeding of the nervous system and host survival. By combining genetic and in vivo in approaches, our studies reveal that the balance between latent and lytic programs is a process occurring early in the trigeminal ganglion. Unexpectedly, activation of the latent program precedes entry into the lytic program by 12 -14hrs. Importantly, at the individual neuronal level, the lytic program begins as a transition out of this acute stage latent program and this escape from the default latent program is regulated by de novo VP16 expression. Our findings support a model in which regulated de novo VP16 expression in the neuron mediates entry into the lytic cycle during the earliest stages of virus infection in vivo. These findings support the hypothesis that the loose association of VP16 with the viral tegument combined with sensory axon length and transport mechanisms serve to limit arrival of virion associated VP16 into neuronal nuclei favoring latency. Further, our findings point to specialized features of the VP16 promoter that control the de novo expression of VP16 in neurons and this regulation is a key component in setting the balance between lytic and latent infections in the nervous system.

  3. Induction of epstein-barr virus (EBV lytic cycle in vitro causes lipid peroxidation, protein oxidation and DNA damage in lymphoblastoid B cell lines

    Directory of Open Access Journals (Sweden)

    benmansour Riadh

    2011-07-01

    Full Text Available Abstract Background We investigated the oxidative modifications of lipids, proteins and DNA, potential molecular targets of oxidative stress, in two lymphoblastoid cell lines: B95-8 and Raji, after EBV lytic cycle induction. Conjugated dienes level was measured as biomarker of lipid peroxidation. Malondialdehyde adduct and protein carbonyl levels, as well as protein thiol levels were measured as biomarkers of protein oxidation. DNA fragmentation was evaluated as biomarker of DNA oxidation. Results After 48 h (peak of lytic cycle, a significant increase in conjugated dienes level was observed in B95-8 and Raji cell lines (p = 0.0001 and p = 0.019 respectively. Malondialdehyde adduct, protein carbonyl levels were increased in B95-8 and Raji cell lines after EBV lytic cycle induction as compared to controls (MDA-adduct: p = 0.008 and p = 0.006 respectively; Carbonyl: p = 0.003 and p = 0.0039 respectively. Proteins thiol levels were decreased by induction in B95-8 and Raji cell lines (p = 0.046; p = 0.002 respectively. DNA fragmentation was also detected in B95-8 and Raji cell lines after EBV lytic cycle induction as compared to controls. Conclusion The results of this study demonstrate the presence of increased combined oxidative modifications in lipids, proteins in B95-8 and Raji cells lines after EBV lytic cycle induction. These results suggest that lipid peroxidation, protein oxidation and DNA fragmentation are generally induced during EBV lytic cycle induction and probably contribute to the cytopathic effect of EBV.

  4. Isolation, Characterization, and Bioinformatic Analyses of Lytic Salmonella Enteritidis Phages and Tests of Their Antibacterial Activity in Food.

    Science.gov (United States)

    Han, Han; Wei, Xiaoting; Wei, Yi; Zhang, Xiufeng; Li, Xuemin; Jiang, Jinzhong; Wang, Ran

    2017-02-01

    Salmonella Enteritidis remains a major threat for food safety. To take efforts to develop phage-based biocontrol for S. Enteritidis contamination in food, in this study, the phages against S. Enteritidis were isolated from sewage samples, characterized by host range assays, DNA restriction enzyme pattern analyses, and transmission electron microscope observations, and tested for antibacterial activity in food; some potent phages were further characterized by bioinformatic analyses. Results showed that based on the plaque quality and host range, seven lytic phages targeting S. Enteritidis were selected, considered as seven distinct phages through DNA physical maps, and classified as Myoviridae or Siphoviridae family by morphologic observations; the combined use of such seven strain phages as a "food additive" could succeed in controlling the artificial S. Enteritidis contamination in the different physical forms of food at a range of temperatures; by bioinformatic analyses, both selected phage BPS11Q3 and BPS15Q2 seemed to be newfound obligate lytic phage strains with no indications for any potentially harmful genes in their genomes. In conclusion, our results showed a potential of isolated phages as food additives for controlling S. Enteritidis contamination in some salmonellosis outbreak-associated food vehicles, and there could be minimized potential risk associated with using BPS11Q3 and BPS15Q2 in food.

  5. Interactions of a lytic peptide with supported lipid bilayers investigated by time-resolved evanescent wave-induced fluorescence spectroscopy

    Science.gov (United States)

    Rapson, Andrew C.; Gee, Michelle L.; Clayton, Andrew H. A.; Smith, Trevor A.

    2016-12-01

    We report investigations, using time-resolved and polarised evanescent wave-induced fluorescence methods, into the location, orientation and mobility of a fluorescently labelled form of the antimicrobial peptide, melittin, when it interacts with vesicles and supported lipid bilayers (SLBs). This melittin analogue, termed MK14-A430, was found to penetrate the lipid headgroup structure in pure, ordered-phase DPPC membranes but was located near the headgroup-water region when cholesterol was included. MK14-A430 formed lytic pores in SLBs, and an increase in pore formation with incubation time was observed through an increase in polarity and mobility of the probe. When associated with the Cholesterol-containing SLB, the probe displayed polarity and mobility that indicated a population distributed near the lipid headgroup-water interface with MK14-A430 arranged predominantly in a surface-aligned state. This study indicates that the lytic activity of MK14-A430 occurred through a pore-forming mechanism. The lipid headgroup environment experienced by the fluorescent label, where MK14-A430 displayed pore information, indicated that pore formation was best described by the toroidal pore model.

  6. A comparative study on the activity of fungal lytic polysaccharide monooxygenases for the depolymerization of cellulose in soybean spent flakes.

    Science.gov (United States)

    Pierce, Brian C; Agger, Jane Wittrup; Zhang, Zhenghong; Wichmann, Jesper; Meyer, Anne S

    2017-09-08

    Lytic polysaccharide monooxygenases (LPMOs) are copper-dependent enzymes capable of the oxidative breakdown of polysaccharides. They are of industrial interest due to their ability to enhance the enzymatic depolymerization of recalcitrant substrates by glycoside hydrolases. In this paper, twenty-four lytic polysaccharide monooxygenases (LPMOs) expressed in Trichoderma reesei were evaluated for their ability to oxidize the complex polysaccharides in soybean spent flakes, an abundant and industrially relevant substrate. TrCel61A, a soy-polysaccharide-active AA9 LPMO from T. reesei, was used as a benchmark in this evaluation. In total, seven LPMOs demonstrated activity on pretreated soy spent flakes, with the products from enzymatic treatments evaluated using mass spectrometry and high performance anion exchange chromatography. The hydrolytic boosting effect of the top-performing enzymes was evaluated in combination with endoglucanase and beta-glucosidase. Two enzymes (TrCel61A and Aspte6) showed the ability to release more than 36% of the pretreated soy spent flake glucose - a greater than 75% increase over the same treatment without LPMO addition. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Effective inhibition of lytic development of bacteriophages λ, P1 and T4 by starvation of their host, Escherichia coli

    Directory of Open Access Journals (Sweden)

    Węgrzyn Alicja

    2007-02-01

    Full Text Available Abstract Background Bacteriophage infections of bacterial cultures cause serious problems in genetic engineering and biotechnology. They are dangerous not only because of direct effects on the currently infected cultures, i.e. their devastation, but also due to a high probability of spreading the phage progeny throughout a whole laboratory or plant, which causes a real danger for further cultivations. Therefore, a simple method for quick inhibition of phage development after detection of bacterial culture infection should be very useful. Results Here, we demonstrate that depletion of a carbon source from the culture medium, which provokes starvation of bacterial cells, results in rapid inhibition of lytic development of three Escherichia coli phages, λ, P1 and T4. Since the effect was similar for three different phages, it seems that it may be a general phenomenon. Moreover, similar effects were observed in flask cultures and in chemostats. Conclusion Bacteriophage lytic development can be inhibited efficiently by carbon source limitation in bacterial cultures. Thus, if bacteriophage contamination is detected, starvation procedures may be recommended to alleviate deleterious effects of phage infection on the culture. We believe that this strategy, in combination with the use of automated and sensitive bacteriophage biosensors, may be employed in the fermentation laboratory practice to control phage outbreaks in bioprocesses more effectively.

  8. Screening of the Human Kinome Identifies MSK1/2-CREB1 as an Essential Pathway Mediating Kaposi's Sarcoma-Associated Herpesvirus Lytic Replication during Primary Infection

    Science.gov (United States)

    Cheng, Fan; Sawant, Tanvee Vinod; Lan, Ke; Lu, Chun; Jung, Jae U.

    2015-01-01

    ABSTRACT Viruses often hijack cellular pathways to facilitate infection and replication. Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic gammaherpesvirus etiologically associated with Kaposi's sarcoma, a vascular tumor of endothelial cells. Despite intensive studies, cellular pathways mediating KSHV infection and replication are still not well defined. Using an antibody array approach, we examined cellular proteins phosphorylated during primary KSHV infection of primary human umbilical vein endothelial cells. Enrichment analysis identified integrin/mitogen-activated protein kinase (integrin/MAPK), insulin/epidermal growth factor receptor (insulin/EGFR), and JAK/STAT as the activated networks during primary KSHV infection. The transcriptional factor CREB1 (cyclic AMP [cAMP]-responsive element-binding protein 1) had the strongest increase in phosphorylation. While knockdown of CREB1 had no effect on KSHV entry and trafficking, it drastically reduced the expression of lytic transcripts and proteins and the production of infectious virions. Chemical activation of CREB1 significantly enhanced viral lytic replication. In contrast, CREB1 neither influenced the expression of the latent gene LANA nor affected KSHV infectivity. Mechanistically, CREB1 was not activated through the classic cAMP/protein kinase A (cAMP/PKA) pathway or via the AKT, MK2, and RSK pathways. Rather, CREB1 was activated by the mitogen- and stress-activated protein kinases 1 and 2 (MSK1/2). Consequently, chemical inhibition or knockdown of MSKs significantly inhibited the KSHV lytic replication program; however, it had a minimal effect on LANA expression and KSHV infectivity. Together, these results identify the MSK1/2-CREB1 proteins as novel essential effectors of KSHV lytic replication during primary infection. The differential effect of the MSK1/2-CREB1 pathway on the expression of viral latent and lytic genes might control the robustness of viral lytic replication, and therefore the

  9. Assessment of microorganisms from Indonesian Oil Fields

    Energy Technology Data Exchange (ETDEWEB)

    Kadarwati, S.; Udiharto, M.; Rahman, M.; Jasjfi, E.; Legowo, E.H. [Research and Development Centre for Oil and Gas Technology LEMIGAS, Jakarta Selatan (Indonesia)

    1995-12-31

    Petroleum resources have been the mainstay of the national development in Indonesia. However, resources are being depleted after over a century of exploitation, while the demand continues to grow with the rapid economic development of the country. In facing the problem, EOR has been applied in Indonesia, such as the steamflooding project in Duri field, but a more energy efficient technology would be preferable. Therefore, MEOR has been recommended as a promising solution. Our study, aimed at finding indigenous microorganisms which can be developed for application in MEOR, has isolated microbes from some oil fields of Indonesia. These microorganisms have been identified, their activities studied, and the effects of their metabolisms examined. This paper describes the research carried out by LEMIGAS in this respect, giving details on the methods of sampling, incubation, identification, and activation of the microbes as well as tests on the effects of their metabolites, with particular attention to those with potential for application in MEOR.

  10. UV inactivation of pathogenic and indicator microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Chang, J.C.; Ossoff, S.F.; Lobe, D.C.; Dorfman, M.H.; Dumais, C.M.; Qualls, R.G.; Johnson, J.D.

    1985-06-01

    Survival was measured as a function of the dose of germicidal UV light for the bacteria Escherichia coli, Salmonella typhi, Shigella sonnei, Streptococcus faecalis, Staphylococcus aureus, and Bacillus subtilis spores, the enteric viruses poliovirus type 1 and simian rotavirus SA11, the cysts of the protozoan Acanthamoeba castellanii, as well as for total coliforms and standard plate count microorganisms from secondary effluent. The doses of UV light necessary for a 99.9% inactivation of the cultured vegetative bacteria, total coliforms, and standard plate count microorganisms were comparable. However, the viruses, the bacterial spores, and the amoebic cysts required about 3 to 4 times, 9 times, and 15 times, respectively, the dose required for E. coli. These ratios covered a narrower relative dose range than that previously reported for chlorine disinfection of E. coli, viruses, spores, and cysts.

  11. Interactions of chromium with microorganisms and plants.

    Science.gov (United States)

    Cervantes, C; Campos-García, J; Devars, S; Gutiérrez-Corona, F; Loza-Tavera, H; Torres-Guzmán, J C; Moreno-Sánchez, R

    2001-05-01

    Chromium is a highly toxic non-essential metal for microorganisms and plants. Due to its widespread industrial use, chromium (Cr) has become a serious pollutant in diverse environmental settings. The hexavalent form of the metal, Cr(VI), is considered a more toxic species than the relatively innocuous and less mobile Cr(III) form. The presence of Cr in the environment has selected microbial and plant variants able to tolerate high levels of Cr compounds. The diverse Cr-resistance mechanisms displayed by microorganisms, and probably by plants, include biosorption, diminished accumulation, precipitation, reduction of Cr(VI) to Cr(III), and chromate efflux. Some of these systems have been proposed as potential biotechnological tools for the bioremediation of Cr pollution. In this review we summarize the interactions of bacteria, algae, fungi and plants with Cr and its compounds.

  12. Microorganisms detection on substrates using QCL spectroscopy

    Science.gov (United States)

    Padilla-Jiménez, Amira C.; Ortiz-Rivera, William; Castro-Suarez, John R.; Ríos-Velázquez, Carlos; Vázquez-Ayala, Iris; Hernández-Rivera, Samuel P.

    2013-05-01

    Recent investigations have focused on the improvement of rapid and accurate methods to develop spectroscopic markers of compounds constituting microorganisms that are considered biological threats. Quantum cascade lasers (QCL) systems have revolutionized many areas of research and development in defense and security applications, including his area of research. Infrared spectroscopy detection based on QCL was employed to acquire mid infrared (MIR) spectral signatures of Bacillus thuringiensis (Bt), Escherichia coli (Ec) and Staphylococcus epidermidis (Se), which were used as biological agent simulants of biothreats. The experiments were carried out in reflection mode on various substrates such as cardboard, glass, travel baggage, wood and stainless steel. Chemometrics statistical routines such as principal component analysis (PCA) regression and partial least squares-discriminant analysis (PLS-DA) were applied to the recorded MIR spectra. The results show that the infrared vibrational techniques investigated are useful for classification/detection of the target microorganisms on the types of substrates studied.

  13. Consolidated bioprocessing method using thermophilic microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Mielenz, Jonathan Richard

    2016-02-02

    The present invention is directed to a method of converting biomass to biofuel, and particularly to a consolidated bioprocessing method using a co-culture of thermophilic and extremely thermophilic microorganisms which collectively can ferment the hexose and pentose sugars produced by degradation of cellulose and hemicelluloses at high substrate conversion rates. A culture medium therefor is also provided as well as use of the methods to produce and recover cellulosic ethanol.

  14. Control of microorganisms in flowing nutrient solutions.

    Science.gov (United States)

    Evans, R D

    1994-11-01

    Controlling microorganisms in flowing nutrient solutions involves different techniques when targeting the nutrient solution, hardware surfaces in contact with the solution, or the active root zone. This review presents basic principles and applications of a number of treatment techniques, including disinfection by chemicals, ultrafiltration, ultrasonics, and heat treatment, with emphasis on UV irradiation and ozone treatment. Procedures for control of specific pathogens by nutrient solution conditioning also are reviewed.

  15. Mass Spectrometer for Airborne Micro-Organisms

    Science.gov (United States)

    Sinha, M. P.; Friedlander, S. K.

    1986-01-01

    Bacteria and other micro-organisms identified continously with aid of new technique for producing samples for mass spectrometer. Technique generates aerosol of organisms and feeds to spectrometer. Given species of organism produces characteristic set of peaks in mass spectrum and thereby identified. Technique useful for monitoring bacterial makeup in environmental studies and in places where cleanliness is essential, such as hospital operating rooms, breweries, and pharmaceutical plants.

  16. Biology Students’ Initial Mental Model about Microorganism

    Science.gov (United States)

    Hamdiyati, Y.; Sudargo, F.; Redjeki, S.; Fitriani, A.

    2017-02-01

    The purpose of this study was to identify biology students’ initial mental model about microorganism. This research used descriptive method with 32 sixth semester biology students at Biology Education Departement-Universitas Pendidikan Indonesia as its respondents. Data was taken at the beginning of the 6th semester before respondents endure microbiology course. Instrument used to assess mental model was drawing-writing test in which it contains concepts such as structure of bacteria, archaea, virus, and fungi. Students were asked to describe their imagination about the structure of microorganisms and subsequently asked to explain the structure of microorganisms in writing through open-ended questions. Students’ response was then compared to scientists or experts’ mental models as the targeted mental model. Student mental models were categorized into five levels (levels 1-5), namely “there is no drawing/writing,” “wrong or irrelevant drawing/writing of question,” “partially correct drawing/writing,” “the drawing/writing that has some deficiencies,” and “completely correct and complete drawing/writing.” Results showed that the level of mental models through drawing or writing about the four concepts were varied. The highest level of mental models through drawing (D5) was found in the concept of bacteria, while the highest level of mental models through writing (W3) was found in the concept of bacteria, virus, and fungi. Mental model levels most commonly found in each concept through drawing-writing tests (D/W) were bacteria (D2/W2), Archaea (D1/W1 and D2/W2), virus (D3/W3), and fungi (D2/W1). From these results it is advisable to improve lectures and assessment strategy to enhance or complement students’ mental models about microorganisms.

  17. Role of microorganisms in mural paintings decay

    OpenAIRE

    Rosado, T; J. Mirão; Gil, M.; Candeias, A.; Caldeira, A. T.

    2014-01-01

    The action of microbial communities on mural paintings, particularly in mortars and in pictorial layers, triggered numerous studies to identify the main biodeteriogenic agents and to better understand the role of microorganisms in the biodeterioration/biodegradation of these artworks. The biodegradation phenomenon is an important issue for the conservation of cultural heritage that needs urgent answers to their rehabilitation. Microbial activity and their ability to obtain elements by bios...

  18. MODELING THE FATE OF MICROORGANISMS IN WATER, WASTEWATER, AND SOIL

    Science.gov (United States)

    The natural environment is filled with microorganisms, most of which are natural residents and colonize various ecological niches. These microorganisms either live independently within the environment, or live in association with various host organisms. There also are places and ...

  19. Bioemulsan Production by Iranian Oil Reservoirs Microorganisms

    Directory of Open Access Journals (Sweden)

    A Amiriyan, M Mazaheri Assadi, VA Saggadian, A Noohi

    2004-10-01

    Full Text Available The biosurfactants are believed to be surface active components that are shed into the surrounding medium during the growth of the microorganisms. The oil degrading microorganism Acinetobacter calcoaceticus RAG-1 produces a poly-anionic biosurfactant, hetero-polysaccharide bioemulsifier termed as emulsan which forms and stabilizes oil-water emulsions with a variety of hydrophobic substrates. In the present paper results of the possibility of biosurfactant (Emulsan production by microorganisms isolated from Iranian oil reservoirs is presented. Fourthy three gram negative and gram positive, non fermentative, rod bacilli and coccobacilli shaped baceria were isolated from the oil wells of Bibi Hakimeh, Siri, Maroon, Ilam , East Paydar and West Paydar. Out of the isolated strains, 39 bacterial strains showed beta haemolytic activity, further screening revealed the emulsifying activity and surface tension. 11 out of 43 tested emulsifiers were identified as possible biosurfactant producers and two isolates produced large surface tension reduction, indicating the high probability of biosurfactant production. Further investigation revealed that, two gram negative, oxidase negative, aerobic and coccoid rods isolates were the best producers and hence designated as IL-1, PAY-4. Whole culture broth of isolates reduced surface tension from 68 mN /m to 30 and 29.1mN/m, respectively, and were stable during exposure to high salinity (10%NaCl and elevated temperatures(120C for 15 min .

  20. Stress-tolerant P-solubilizing microorganisms.

    Science.gov (United States)

    Vassilev, N; Eichler-Löbermann, B; Vassileva, M

    2012-08-01

    Drought, high/low temperature, and salinity are abiotic stress factors accepted as the main reason for crop yield losses in a world with growing population and food price increases. Additional problems create nutrient limitations and particularly low P soil status. The problem of phosphate fertilizers, P plant nutrition, and existing phosphate bearing resources can also be related to the scarcity of rock phosphate. The modern agricultural systems are highly dependent on the existing fertilizer industry based exclusively of this natural, finite, non-renewable resource. Biotechnology offers a number of sustainable solutions that can mitigate these problems by using plant beneficial, including P-solubilizing, microorganisms. This short review paper summarizes the current and future trends in isolation, development, and application of P-solubilizing microorganisms in stress environmental conditions bearing also in mind the imbalanced cycling and unsustainable management of P. Special attention is devoted to the efforts on development of biotechnological strategies for formulation of P-solubilizing microorganisms in order to increase their protection against adverse abiotic factors.

  1. Biomining: metal recovery from ores with microorganisms.

    Science.gov (United States)

    Schippers, Axel; Hedrich, Sabrina; Vasters, Jürgen; Drobe, Malte; Sand, Wolfgang; Willscher, Sabine

    2014-01-01

    Biomining is an increasingly applied biotechnological procedure for processing of ores in the mining industry (biohydrometallurgy). Nowadays the production of copper from low-grade ores is the most important industrial application and a significant part of world copper production already originates from heap or dump/stockpile bioleaching. Conceptual differences exist between the industrial processes of bioleaching and biooxidation. Bioleaching is a conversion of an insoluble valuable metal into a soluble form by means of microorganisms. In biooxidation, on the other hand, gold is predominantly unlocked from refractory ores in large-scale stirred-tank biooxidation arrangements for further processing steps. In addition to copper and gold production, biomining is also used to produce cobalt, nickel, zinc, and uranium. Up to now, biomining has merely been used as a procedure in the processing of sulfide ores and uranium ore, but laboratory and pilot procedures already exist for the processing of silicate and oxide ores (e.g., laterites), for leaching of processing residues or mine waste dumps (mine tailings), as well as for the extraction of metals from industrial residues and waste (recycling). This chapter estimates the world production of copper, gold, and other metals by means of biomining and chemical leaching (bio-/hydrometallurgy) compared with metal production by pyrometallurgical procedures, and describes new developments in biomining. In addition, an overview is given about metal sulfide oxidizing microorganisms, fundamentals of biomining including bioleaching mechanisms and interface processes, as well as anaerobic bioleaching and bioleaching with heterotrophic microorganisms.

  2. Protein languages differ depending on microorganism lifestyle.

    Directory of Open Access Journals (Sweden)

    Joseph J Grzymski

    Full Text Available Few quantitative measures of genome architecture or organization exist to support assumptions of differences between microorganisms that are broadly defined as being free-living or pathogenic. General principles about complete proteomes exist for codon usage, amino acid biases and essential or core genes. Genome-wide shifts in amino acid usage between free-living and pathogenic microorganisms result in fundamental differences in the complexity of their respective proteomes that are size and gene content independent. These differences are evident across broad phylogenetic groups-a result of environmental factors and population genetic forces rather than phylogenetic distance. A novel comparative analysis of amino acid usage-utilizing linguistic analyses of word frequency in language and text-identified a global pattern of higher peptide word repetition in 376 free-living versus 421 pathogen genomes across broad ranges of genome size, G+C content and phylogenetic ancestry. This imprint of repetitive word usage indicates free-living microorganisms have a bias for repetitive sequence usage compared to pathogens. These findings quantify fundamental differences in microbial genomes relative to life-history function.

  3. Airborne microorganisms in Lascaux Cave (France

    Directory of Open Access Journals (Sweden)

    Pedro M Martin-Sanchez

    2014-09-01

    Full Text Available Lascaux Cave in France contains valuable Palaeolithic paintings. The importance of the paintings, one of the finest examples of European rock art paintings, was recognized shortly after their discovery in 1940. In the 60’s of the past century the cave received a huge number of visitors and suffered a microbial crisis due to the impact of massive tourism and the previous adaptation works carried out to facilitate visits. In 1963, the cave was closed due to the damage produced by visitors’ breath, lighting and algal growth on the paintings. In 2001, an outbreak of the fungus Fusarium solani covered the walls and sediments. Later, black stains, produced by the growth of the fungus Ochroconis lascauxensis, appeared on the walls. In 2006, the extensive black stains constituted the third major microbial crisis. In an attempt to know the dispersion of microorganisms inside the cave, aerobiological and microclimate studies were carried out in two different seasons, when a climate system for preventing condensation of water vapor on the walls was active (September 2010 or inactive (February 2010. The data showed that in September the convection currents created by the climate system evacuated the airborne microorganisms whereas in February they remained in suspension which explained the high concentrations of bacteria and fungi found in the air. This double aerobiological and microclimate study inLascauxCave can help to understand the dispersion of microorganisms and to adopt measures for a correct cave management.

  4. Food fermentations: microorganisms with technological beneficial use.

    Science.gov (United States)

    Bourdichon, François; Casaregola, Serge; Farrokh, Choreh; Frisvad, Jens C; Gerds, Monica L; Hammes, Walter P; Harnett, James; Huys, Geert; Laulund, Svend; Ouwehand, Arthur; Powell, Ian B; Prajapati, Jashbhai B; Seto, Yasuyuki; Ter Schure, Eelko; Van Boven, Aart; Vankerckhoven, Vanessa; Zgoda, Annabelle; Tuijtelaars, Sandra; Hansen, Egon Bech

    2012-03-15

    Microbial food cultures have directly or indirectly come under various regulatory frameworks in the course of the last decades. Several of those regulatory frameworks put emphasis on "the history of use", "traditional food", or "general recognition of safety". Authoritative lists of microorganisms with a documented use in food have therefore come into high demand. One such list was published in 2002 as a result of a joint project between the International Dairy Federation (IDF) and the European Food and Feed Cultures Association (EFFCA). The "2002 IDF inventory" has become a de facto reference for food cultures in practical use. However, as the focus mainly was on commercially available dairy cultures, there was an unmet need for a list with a wider scope. We present an updated inventory of microorganisms used in food fermentations covering a wide range of food matrices (dairy, meat, fish, vegetables, legumes, cereals, beverages, and vinegar). We have also reviewed and updated the taxonomy of the microorganisms used in food fermentations in order to bring the taxonomy in agreement with the current standing in nomenclature.

  5. 21 CFR 866.2660 - Microorganism differentiation and identification device.

    Science.gov (United States)

    2010-04-01

    ... § 866.2660 Microorganism differentiation and identification device. (a) Identification. A microorganism differentiation and identification device is a device intended for medical purposes that consists of one or more... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Microorganism differentiation and identification...

  6. Decalcified allograft in repair of lytic lesions of bone: A study to evolve bone bank in developing countries

    Directory of Open Access Journals (Sweden)

    Anil Kumar Gupta

    2016-01-01

    Full Text Available Background: The quest for ideal bone graft substitutes still haunts orthopedic researchers. The impetus for this search of newer bone substitutes is provided by mismatch between the demand and supply of autogenous bone grafts. Bone banking facilities such as deep frozen and freeze-dried allografts are not so widely available in most of the developing countries. To overcome the problem, we have used partially decalcified, ethanol preserved, and domestic refrigerator stored allografts which are economical and needs simple technology for procurement, preparation, and preservation. The aim of the study was to assess the radiological and functional outcome of the partially decalcified allograft (by weak hydrochloric acid in patients of benign lytic lesions of bone. Through this study, we have also tried to evolve, establish, and disseminate the concept of the bone bank. Materials and Methods: 42 cases of lytic lesions of bone who were treated by decalcified (by weak hydrochloric acid, ethanol preserved, allografts were included in this prospective study. The allograft was obtained from freshly amputated limbs or excised femoral heads during hip arthroplasties under strict aseptic conditions. The causes of lytic lesions were unicameral bone cyst ( n = 3, aneurysmal bone cyst ( n = 3, giant cell tumor ( n = 9, fibrous dysplasia ( n = 12, chondromyxoid fibroma, chondroma, nonossifying fibroma ( n = 1 each, tubercular osteomyelitis ( n = 7, and chronic pyogenic osteomyelitis ( n = 5. The cavity of the lesion was thoroughly curetted and compactly filled with matchstick sized allografts. Results: Quantitative assessment based on the criteria of Sethi et al. (1993 was done. There was complete assimilation in 27 cases, partial healing in 12 cases, and failure in 3 cases. Functional assessment was also done according to which there were 29 excellent results, 6 good, and 7 cases of failure (infection, recurrence, and nonunion of pathological fracture. We

  7. Isolation of Histamine-degrading Enzyme Producing Bacteria from Mackerel and Characteration of Enzyme Concerned%鲭鱼中组胺降解酶产生菌的分离筛选和基本酶学性质研究

    Institute of Scientific and Technical Information of China (English)

    欧昌荣; 汤海青; 张宇琼; 郑洁; 李海波

    2012-01-01

    Marine fishes, scombroid species in paticular, are susceptible to producing histamine during processing and storage, as has been reported in incidents of scombroid fish poisoning. To understand the relationship between the producing and degrading of histamine and the microorganism concerned in fish, the bacterials with the capacity of producing histamine-degrading enzyme are screened from skin, flesh, entrails and gills of mackerel (Pneumatophorus japonicus) by plate and shaking flask culture, followed with testing the enzyme activity by pectrofluorimetry method. A gram-negative rod bacterium producing histamine-degrading enzyme is isolated from entrails of mackerel. The enzyme is presumed to be primary metabolite according to the growth and enzyme production curves. The optimum pH and temperature of the crude enzyme activity to histamine is found to be 7.2 and 35 ℃ respectively, and a high stability of the enzyme is observed at 20-35 ℃ and pH 6.0-8.0. It is activated by 5 mmol·L^-1 of ions such as Mn^2+, Ca^2+, Na^-, Mg^2+, K^+, but inhibited by Zn^2+, Al^3+, Fe^3+, Fe^2+, Cu^2+, and completely inhibited by EDTA. The results of kinetic studies show that the kinetic parameter Km of the enzyme was 0.22 mg.mL^-1, and the Vmax of the enzyme is 156.25 U.mL^-1. This paoer presents the first domestic report oh histamine-degrading enzyme producing bacteria, and the study is believed to be important to seek biological control of histamine in food processing in the future.%鲭鱼亚目的海洋鱼类在捕获后易产生组胺,导致鲭鱼中毒.为研究组胺消长与微生物的关系,通过平板分离和摇瓶发酵,以荧光光度法测定酶活力,从鲭鱼(Pneumatophorus japonicus)皮肉、内脏和腮中分离筛选组胺降解菌,并对所产组胺降解酶的酶学性质进行研究和分析.结果表明:自内脏中分离筛选到一株组胺降解酶活力较高的革兰氏阴性杆菌,从生长产酶曲线推

  8. The loss of immunodominant epitopes affects interferon-γ production and lytic activity of the human influenza virus-specific cytotoxic T lymphocyte response in vitro

    NARCIS (Netherlands)

    E.G.M. Berkhoff (Eufemia); M.M. Geelhoed-Mieras (Martina); E.J. Verschuren (Esther); C.A. van Baalen (Carel); R.A. Gruters (Rob); R.A.M. Fouchier (Ron); A.D.M.E. Osterhaus (Albert); G.F. Rimmelzwaan (Guus)

    2007-01-01

    textabstractIn the present study, we examined the effect of the loss of the human leucocyte antigen (HLA)-B*3501-restricted nucleoprotein (NP)418-426epitope on interferon (IFN)-γ-production and lytic activity of the human cytotoxic T lymphocyte (CTL) response in vitro. Extensive amino acid variation

  9. Bacteriophage formulated into a range of semisolid and solid dosage forms maintain lytic capacity against isolated cutaneous and opportunistic oral bacteria.

    Science.gov (United States)

    Brown, Teagan L; Thomas, Tereen; Odgers, Jessica; Petrovski, Steve; Spark, Marion Joy; Tucci, Joseph

    2017-03-01

    Resistance of bacteria to antimicrobial agents is of grave concern. Further research into the development of bacteriophage as therapeutic agents against bacterial infections may help alleviate this problem. To formulate bacteriophage into a range of semisolid and solid dosage forms and investigate the capacity of these preparations to kill bacteria under laboratory conditions. Bacteriophage suspensions were incorporated into dosage forms such as creams, ointments, pastes, pessaries and troches. These were applied to bacterial lawns in order to ascertain lytic capacity. Stability of these formulations containing phage was tested under various storage conditions. A range of creams and ointments were able to support phage lytic activity against Propionibacterium acnes. Assessment of the stability of these formulations showed that storage at 4 °C in light-protected containers resulted in optimal phage viability after 90 days. Pessaries/suppositories and troches were able to support phage lytic activity against Rhodococcus equi. We report here the in-vitro testing of semisolid and solid formulations of bacteriophage lytic against a range of bacteria known to contribute to infections of the epithelia. This study provides a basis for the future formulation of diverse phage against a range of bacteria that infect epithelial tissues. © 2016 Royal Pharmaceutical Society.

  10. Extracellular electron transfer mechanisms between microorganisms and minerals

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Liang; Dong, Hailiang; Reguera, Gemma; Beyenal, Haluk; Lu, Anhuai; Liu, Juan; Yu, Han-Qing; Fredrickson, James K.

    2016-08-30

    Electrons can be transferred from microorganisms to multivalent metal ions that are associated with minerals and vice versa. As the microbial cell envelope is neither physically permeable to minerals nor electrically conductive, microorganisms have evolved strategies to exchange electrons with extracellular minerals. In this Review, we discuss the molecular mechanisms that underlie the ability of microorganisms to exchange electrons, such as c-type cytochromes and microbial nanowires, with extracellular minerals and with microorganisms of the same or different species. Microorganisms that have extracellular electron transfer capability can be used for biotechnological applications, including bioremediation, biomining and the production of biofuels and nanomaterials.

  11. Enhancement of lytic activity of leukemic cells by CD8+ cytotoxic T lymphocytes generated against a WT1 peptide analogue.

    Science.gov (United States)

    Al Qudaihi, Ghofran; Lehe, Cynthia; Negash, Muna; Al-Alwan, Monther; Ghebeh, Hazem; Mohamed, Said Yousuf; Saleh, Abu-Jafar Mohammed; Al-Humaidan, Hind; Tbakhi, Abdelghani; Dickinson, Anne; Aljurf, Mahmoud; Dermime, Said

    2009-02-01

    The Wilms tumor antigen 1 (WT1) antigen is over-expressed in human leukemias, making it an attractive target for immunotherapy. Most WT1-specific Cytotoxic T Lymphocytes (CTLs) described so far displayed low avidity, limiting its function. To improve the immunogenicity of CTL epitopes, we replaced the first-amino-acid of two known immunogenic WT1-peptides (126 and 187) with a tyrosine. This modification enhances 126Y analogue-binding ability, triggers significant number of IFN-gamma-producing T cells (P = 0.0003), induces CTL that cross-react with the wild-type peptide, exerts a significant lytic activity against peptide-loaded-targets (P = 0.0006) and HLA-A0201-matched-leukemic cells (P = 0.0014). These data support peptide modification as a feasible approach for the development of a leukemia-vaccine.

  12. Oxidative cleavage and hydrolytic boosting of cellulose in soybean spent flakes by Trichoderma reesei Cel61A lytic polysaccharide monooxygenase.

    Science.gov (United States)

    Pierce, Brian C; Agger, Jane Wittrup; Wichmann, Jesper; Meyer, Anne S

    2017-03-01

    The auxiliary activity family 9 (AA9) copper-dependent lytic polysaccharide monooxygenase (LPMO) from Trichoderma reesei (EG4; TrCel61A) was investigated for its ability to oxidize the complex polysaccharides from soybean. The substrate specificity of the enzyme was assessed against a variety of substrates, including both soy spent flake, a by-product of the soy food industry, and soy spent flake pretreated with sodium hydroxide. Products from enzymatic treatments were analyzed using mass spectrometry and high performance anion exchange chromatography. We demonstrate that TrCel61A is capable of oxidizing cellulose from both pretreated soy spent flake and phosphoric acid swollen cellulose, oxidizing at both the C1 and C4 positions. In addition, we show that the oxidative activity of TrCel61A displays a synergistic effect capable of boosting endoglucanase activity, and thereby substrate depolymerization of soy cellulose, by 27%. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Lipid mobilization and acid phosphatase activity in lytic compartments during conidium dormancy and appressorium formation of Colletotrichum graminicola.

    Science.gov (United States)

    Schadeck, R J; Leite, B; de Freitas Buchi, D

    1998-12-01

    Colletotrichum graminicola, a pathogen of sorghum and corn, was investigated prior and during germination as to certain aspects of acid phosphatase activity and lipid mobilization. Ungerminated conidia cytoplasm was filled with lipid deposits, which were mobilized during the germination process. Cytochemical ultrastructural examination showed that conidia vacuoles exhibit acid phosphatase activity, which is suggestive of lytic activity. Lipid bodies, stored in the ungerminated conidia cytoplasm, were internalized by vacuoles in a process analogous to microautophagy and were apparently digested inside them. The lipid bodies disappeared and vacuoles became enlarged in conidial cells during germination. Appressoria also showed acid phosphatase activity in multiple heterogeneous vesicles which were, in most cases, juxtaposed with lipid bodies. These results suggest that the vacuolar system plays an important role during C. graminicola germination and that the initial stages of lipid metabolization are taking place inside the vacuoles.

  14. Lytic polysaccharide monooxygenases: a crystallographer’s view on a new class of biomass-degrading enzymes

    Science.gov (United States)

    Frandsen, Kristian E. H.; Lo Leggio, Leila

    2016-01-01

    Lytic polysaccharide monooxygenases (LPMOs) are a new class of microbial copper enzymes involved in the degradation of recalcitrant polysaccharides. They have only been discovered and characterized in the last 5–10 years and have stimulated strong interest both in biotechnology and in bioinorganic chemistry. In biotechnology, the hope is that these enzymes will finally help to make enzymatic biomass conversion, especially of lignocellulosic plant waste, economically attractive. Here, the role of LPMOs is likely to be in attacking bonds that are not accessible to other enzymes. LPMOs have attracted enormous interest since their discovery. The emphasis in this review is on the past and present contribution of crystallographic studies as a guide to functional understanding, with a final look towards the future. PMID:27840684

  15. Effects of Heavy Metals on Activated Sludge Microorganism

    Institute of Scientific and Technical Information of China (English)

    XIE Bing; XI Dan-li; CHEN Ji-hua

    2002-01-01

    The efforts of heavy metals on activated sludge microorganisms are reviewed. Although some heavy metals play an important role in the life of microorganism, heavy metals concentrations above toxic levels inhibit biological processes. Copper, zinc, nickel,cadmium and chromium were mostly studied because of their toxicity and widely used, regardless of single or combination. The microorganism response to these heavy metals varied with species and concentrations of metals,factors such as pH, sludge age, MLSS etc. also affect toxicity on the microorganism. The acclimation could extend the microorganism tolerance of heavy metals. The effects of heavy metals on sludge microorganisms could be described with different models, such as Sigmoidal and Monod equation. The kinetic constants are the useful indexes to estimate the heavy metals inhibition on activated sludge system. Methods to measure the toxicity and effects on microorganism community were also reviewed.

  16. Screening of biosurfactants from cloud microorganisms

    Science.gov (United States)

    Sancelme, Martine; Canet, Isabelle; Traikia, Mounir; Uhliarikova, Yveta; Capek, Peter; Matulova, Maria; Delort, Anne-Marie; Amato, Pierre

    2015-04-01

    The formation of cloud droplets from aerosol particles in the atmosphere is still not well understood and a main source of uncertainties in the climate budget today. One of the principal parameters in these processes is the surface tension of atmospheric particles, which can be strongly affected by trace compounds called surfactants. Within a project devoted to bring information on atmospheric surfactants and their effects on cloud droplet formation, we focused on surfactants produced by microorganisms present in atmospheric waters. From our unique collection of microorganisms, isolated from cloud water collected at the Puy-de-Dôme (France),1 we undertook a screening of this bank for biosurfactant producers. After extraction of the supernatants of the pure cultures, surface tension of crude extracts was determined by the hanging drop technique. Results showed that a wide variety of microorganisms are able to produce biosurfactants, some of them exhibiting strong surfactant properties as the resulting tension surface decreases to values less then 35 mN.m-1. Preliminary analytical characterization of biosurfactants, obtained after isolation from overproducing cultures of Rhodococcus sp. and Pseudomonas sp., allowed us to identify them as belonging to two main classes, namely glycolipids and glycopeptides. 1. Vaïtilingom, M.; Attard, E.; Gaiani, N.; Sancelme, M.; Deguillaume, L.; Flossmann, A. I.; Amato, P.; Delort, A. M. Long-term features of cloud microbiology at the puy de Dôme (France). Atmos. Environ. 2012, 56, 88-100. Acknowledgements: This work is supported by the French-USA ANR SONATA program and the French-Slovakia programs Stefanik and CNRS exchange.

  17. RTA Occupancy of the Origin of Lytic Replication during Murine Gammaherpesvirus 68 Reactivation from B Cell Latency

    Directory of Open Access Journals (Sweden)

    Alexis L. Santana

    2017-02-01

    Full Text Available RTA, the viral Replication and Transcription Activator, is essential for rhadinovirus lytic gene expression upon de novo infection and reactivation from latency. Lipopolysaccharide (LPS/toll-like receptor (TLR4 engagement enhances rhadinovirus reactivation. We developed two new systems to examine the interaction of RTA with host NF-kappaB (NF-κB signaling during murine gammaherpesvirus 68 (MHV68 infection: a latent B cell line (HE-RIT inducible for RTA-Flag expression and virus reactivation; and a recombinant virus (MHV68-RTA-Bio that enabled in vivo biotinylation of RTA in BirA transgenic mice. LPS acted as a second stimulus to drive virus reactivation from latency in the context of induced expression of RTA-Flag. ORF6, the gene encoding the single-stranded DNA binding protein, was one of many viral genes that were directly responsive to RTA induction; expression was further increased upon treatment with LPS. However, NF-κB sites in the promoter of ORF6 did not influence RTA transactivation in response to LPS in HE-RIT cells. We found no evidence for RTA occupancy of the minimal RTA-responsive region of the ORF6 promoter, yet RTA was found to complex with a portion of the right origin of lytic replication (oriLyt-R that contains predicted RTA recognition elements. RTA occupancy of select regions of the MHV-68 genome was also evaluated in our novel in vivo RTA biotinylation system. Streptavidin isolation of RTA-Bio confirmed complex formation with oriLyt-R in LPS-treated primary splenocytes from BirA mice infected with MHV68 RTA-Bio. We demonstrate the utility of reactivation-inducible B cells coupled with in vivo RTA biotinylation for mechanistic investigations of the interplay of host signaling with RTA.

  18. Novel bacteriophage lysin with broad lytic activity protects against mixed infection by Streptococcus pyogenes and methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Gilmer, Daniel B; Schmitz, Jonathan E; Euler, Chad W; Fischetti, Vincent A

    2013-06-01

    Methicillin-resistant Staphylococcus aureus (MRSA) and Streptococcus pyogenes (group A streptococcus [GrAS]) cause serious and sometimes fatal human diseases. They are among the many Gram-positive pathogens for which resistance to leading antibiotics has emerged. As a result, alternative therapies need to be developed to combat these pathogens. We have identified a novel bacteriophage lysin (PlySs2), derived from a Streptococcus suis phage, with broad lytic activity against MRSA, vancomycin-intermediate S. aureus (VISA), Streptococcus suis, Listeria, Staphylococcus simulans, Staphylococcus epidermidis, Streptococcus equi, Streptococcus agalactiae (group B streptococcus [GBS]), S. pyogenes, Streptococcus sanguinis, group G streptococci (GGS), group E streptococci (GES), and Streptococcus pneumoniae. PlySs2 has an N-terminal cysteine-histidine aminopeptidase (CHAP) catalytic domain and a C-terminal SH3b binding domain. It is stable at 50 °C for 30 min, 37 °C for >24 h, 4°C for 15 days, and -80 °C for >7 months; it maintained full activity after 10 freeze-thaw cycles. PlySs2 at 128 μg/ml in vitro reduced MRSA and S. pyogenes growth by 5 logs and 3 logs within 1 h, respectively, and exhibited a MIC of 16 μg/ml for MRSA. A single, 2-mg dose of PlySs2 protected 92% (22/24) of the mice in a bacteremia model of mixed MRSA and S. pyogenes infection. Serially increasing exposure of MRSA and S. pyogenes to PlySs2 or mupirocin resulted in no observed resistance to PlySs2 and resistance to mupirocin. To date, no other lysin has shown such notable broad lytic activity, stability, and efficacy against multiple, leading, human bacterial pathogens; as such, PlySs2 has all the characteristics to be an effective therapeutic.

  19. RTA Occupancy of the Origin of Lytic Replication during Murine Gammaherpesvirus 68 Reactivation from B Cell Latency

    Science.gov (United States)

    Santana, Alexis L.; Oldenburg, Darby G.; Kirillov, Varvara; Malik, Laraib; Dong, Qiwen; Sinayev, Roman; Marcu, Kenneth B.; White, Douglas W.; Krug, Laurie T.

    2017-01-01

    RTA, the viral Replication and Transcription Activator, is essential for rhadinovirus lytic gene expression upon de novo infection and reactivation from latency. Lipopolysaccharide (LPS)/toll-like receptor (TLR)4 engagement enhances rhadinovirus reactivation. We developed two new systems to examine the interaction of RTA with host NF-kappaB (NF-κB) signaling during murine gammaherpesvirus 68 (MHV68) infection: a latent B cell line (HE-RIT) inducible for RTA-Flag expression and virus reactivation; and a recombinant virus (MHV68-RTA-Bio) that enabled in vivo biotinylation of RTA in BirA transgenic mice. LPS acted as a second stimulus to drive virus reactivation from latency in the context of induced expression of RTA-Flag. ORF6, the gene encoding the single-stranded DNA binding protein, was one of many viral genes that were directly responsive to RTA induction; expression was further increased upon treatment with LPS. However, NF-κB sites in the promoter of ORF6 did not influence RTA transactivation in response to LPS in HE-RIT cells. We found no evidence for RTA occupancy of the minimal RTA-responsive region of the ORF6 promoter, yet RTA was found to complex with a portion of the right origin of lytic replication (oriLyt-R) that contains predicted RTA recognition elements. RTA occupancy of select regions of the MHV-68 genome was also evaluated in our novel in vivo RTA biotinylation system. Streptavidin isolation of RTA-Bio confirmed complex formation with oriLyt-R in LPS-treated primary splenocytes from BirA mice infected with MHV68 RTA-Bio. We demonstrate the utility of reactivation-inducible B cells coupled with in vivo RTA biotinylation for mechanistic investigations of the interplay of host signaling with RTA. PMID:28212352

  20. Microorganisms as Indicators of Soil Health

    DEFF Research Database (Denmark)

    Nielsen, M. N.; Winding, A.; Binnerup, S.

    Microorganisms are an essential part of living soil and of outmost importance for soil health. As such they can be used as indicators of soil health. This report reviews the current and potential future use of microbial indicators of soil health and recommends specific microbial indicators for soil...... ecosystem parameters representing policy relevant end points. It is further recommended to identify a specific minimum data set for specific policy relevant end points, to carefully establish baseline values, to improve scientific knowledge on biodiversity and modelling of soil data, and to implement new...... indicators into soil monitoring programmes as they become applicable....

  1. Resistance of soil microorganisms to starvation.

    Science.gov (United States)

    Chen, M.; Alexander, M.

    1972-01-01

    Most groups of soil microorganisms died when exposed to prolonged starvation in a carbon-free solution, but the relative abundance of Bacillus and actinomycetes increased with time. Certain nonspore-forming bacteria also persisted. The ability of individual soil isolates to endure starvation in solution was not correlated with their glycogen content or rate of endogenous respiration. However, cells of the resistant populations were rich in poly-beta-hydroxybutyrate, whereas the starvation-susceptible bacteria generally contained little of this substance. Poly-beta-hydroxybutyrate was used rapidly in cells deprived of exogenous sources of carbon.

  2. Green biosynthesis of floxuridine by immobilized microorganisms.

    Science.gov (United States)

    Rivero, Cintia W; Britos, Claudia N; Lozano, Mario E; Sinisterra, Jose V; Trelles, Jorge A

    2012-06-01

    This work describes an efficient, simple, and green bioprocess for obtaining 5-halogenated pyrimidine nucleosides from thymidine by transglycosylation using whole cells. Biosynthesis of 5-fluoro-2'-deoxyuridine (floxuridine) was achieved by free and immobilized Aeromonas salmonicida ATCC 27013 with an 80% and 65% conversion occurring in 1 h, respectively. The immobilized biocatalyst was stable for more than 4 months in storage conditions (4 °C) and could be reused at least 30 times without loss of its activity. This microorganism was able to biosynthesize 2.0 mg L(-1) min(-1) (60%) of 5-chloro-2'-deoxyuridine in 3 h. These halogenated pyrimidine 2'-deoxynucleosides are used as antitumoral agents.

  3. Toolbox for Antibiotics Discovery from Microorganisms.

    Science.gov (United States)

    Fisch, Katja M; Schäberle, Till F

    2016-09-01

    Microorganisms produce a vast array of biologically active metabolites. Such compounds are applied by humans to positively influence their health and, therefore, natural products serve as drug leads for pharmaceutical and medicinal chemistry. In this minireview, tools for the discovery and the production of potential drug leads are explained. A snapshot is provided, starting from the isolation of new producer strains, across genomic mining of (meta)genomes to identify biosynthetic gene clusters corresponding to natural products, toward heterologous expression to produce potential drug leads. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Lead resistance in micro-organisms.

    Science.gov (United States)

    Jarosławiecka, Anna; Piotrowska-Seget, Zofia

    2014-01-01

    Lead (Pb) is an element present in the environment that negatively affects all living organisms. To diminish its high toxicity, micro-organisms have developed several mechanisms that allow them to survive exposure to Pb(II). The main mechanisms of lead resistance involve adsorption by extracellular polysaccharides, cell exclusion, sequestration as insoluble phosphates, and ion efflux to the cell exterior. This review describes the various lead resistance mechanisms, and the regulation of their expression by lead binding regulatory proteins. Special attention is given to the Pbr system from Cupriavidus metallidurans CH34, which involves a unique mechanism combining efflux and lead precipitation.

  5. Microorganisms and biomolecules in space hard environment

    Science.gov (United States)

    Horneck, G.

    1981-01-01

    Microorganisms and biomolecules exposed to space vacuum and to different intensities of selected wavelengths of solar ultraviolet radiation is studied. The influence of these factors, applied singly or simultaneously, on the integrity of microbial systems and biomolecules is measured. Specifically, this experiment will study in Bacillus subtilis spores (1) disturbances in subsequent germination, outgrowth, and colony formation; (2) photochemical reactions of the DNA and protein in vivo and in vitro and their role in biological injury; and (3) the efficiency of repair processes in these events.

  6. Mixing by microorganisms in stratified fluids

    CERN Document Server

    Wagner, Gregory L; Lauga, Eric

    2014-01-01

    We examine the vertical mixing induced by the swimming of microorganisms at low Reynolds and P\\'eclet numbers in a stably stratified ocean, and show that the global contribution of oceanic microswimmers to vertical mixing is negligible. We propose two approaches to estimating the mixing efficiency, $\\eta$, or the ratio of the rate of potential energy creation to the total rate-of-working on the ocean by microswimmers. The first is based on scaling arguments and estimates $\\eta$ in terms of the ratio between the typical organism size, $a$, and an intrinsic length scale for the stratified flow, $\\ell = \\left ( \

  7. Microorganisms and radionuclides in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Yoshitomo [Central Research Inst. of Electric Power Industry, Abiko, Chiba (Japan)

    2002-11-01

    The influence of microorganisms on the behavior of radionuclides in the subsurface environment is one of the factors to be concerned with for the safety assessment of the geological disposal of radioactive waste. It is considered that the important microbiological aspects with respect to radionuclide behavior are biological adsorption, oxidation-reduction and complex formation between organic matter and radionuclides. These phenomena with respect to radionuclides, especially actinides, in the environment should be understood. A description of two studies, illustrating these points are presented. (author)

  8. Engineering photosynthesis in plants and synthetic microorganisms.

    Science.gov (United States)

    Maurino, Veronica G; Weber, Andreas P M

    2013-01-01

    Photosynthetic organisms, such as cyanobacteria, algae, and plants, sustain life on earth by converting light energy, water, and CO(2) into chemical energy. However, due to global change and a growing human population, arable land is becoming scarce and resources, including water and fertilizers, are becoming exhausted. It will therefore be crucial to design innovative strategies for sustainable plant production to maintain the food and energy bases of human civilization. Several different strategies for engineering improved photosynthesis in crop plants and introducing novel photosynthetic capacity into microorganisms have been reviewed.

  9. Microorganisms in human milk: lights and shadows.

    Science.gov (United States)

    Civardi, Elisa; Garofoli, Francesca; Tzialla, Chryssoula; Paolillo, Piermichele; Bollani, Lina; Stronati, Mauro

    2013-10-01

    Human milk has been traditionally considered germ free, however, recent studies have shown that it represents a continuous supply of commensal and potentially probiotic bacteria to the infant gut. Mammary microbioma may exercise anti-infective, anti-inflammatory, immunomodulatory and metabolic properties. Moreover human milk may be a source of pathogenic microorganism during maternal infection, if contaminated during expression or in case of vaccination of the mother. The non-sterility of breast milk can, thus, be seen as a protective factor, or rarely, as a risk factor for the newborn.

  10. CTCF and Rad21 act as host cell restriction factors for Kaposi's sarcoma-associated herpesvirus (KSHV lytic replication by modulating viral gene transcription.

    Directory of Open Access Journals (Sweden)

    Da-Jiang Li

    2014-01-01

    Full Text Available Kaposi's sarcoma-associated herpesvirus (KSHV is a human herpesvirus that causes Kaposi's sarcoma and is associated with the development of lymphoproliferative diseases. KSHV reactivation from latency and virion production is dependent on efficient transcription of over eighty lytic cycle genes and viral DNA replication. CTCF and cohesin, cellular proteins that cooperatively regulate gene expression and mediate long-range DNA interactions, have been shown to bind at specific sites in herpesvirus genomes. CTCF and cohesin regulate KSHV gene expression during latency and may also control lytic reactivation, although their role in lytic gene expression remains incompletely characterized. Here, we analyze the dynamic changes in CTCF and cohesin binding that occur during the process of KSHV viral reactivation and virion production by high resolution chromatin immunoprecipitation and deep sequencing (ChIP-Seq and show that both proteins dissociate from viral genomes in kinetically and spatially distinct patterns. By utilizing siRNAs to specifically deplete CTCF and Rad21, a cohesin component, we demonstrate that both proteins are potent restriction factors for KSHV replication, with cohesin knockdown leading to hundred-fold increases in viral yield. High-throughput RNA sequencing was used to characterize the transcriptional effects of CTCF and cohesin depletion, and demonstrated that both proteins have complex and global effects on KSHV lytic transcription. Specifically, both proteins act as positive factors for viral transcription initially but subsequently inhibit KSHV lytic transcription, such that their net effect is to limit KSHV RNA accumulation. Cohesin is a more potent inhibitor of KSHV transcription than CTCF but both proteins are also required for efficient transcription of a subset of KSHV genes. These data reveal novel effects of CTCF and cohesin on transcription from a relatively small genome that resemble their effects on the cellular

  11. Cross talk between EBV and telomerase: the role of TERT and NOTCH2 in the switch of latent/lytic cycle of the virus.

    Science.gov (United States)

    Giunco, S; Celeghin, A; Gianesin, K; Dolcetti, R; Indraccolo, S; De Rossi, A

    2015-05-28

    Epstein-Barr virus (EBV)-associated malignancies, as well as lymphoblastoid cell lines (LCLs), obtained in vitro by EBV infection of B cells, express latent viral proteins and maintain their ability to grow indefinitely through inappropriate activation of telomere-specific reverse transcriptase (TERT), the catalytic component of telomerase. Our previous studies demonstrated that high levels of TERT expression in LCLs prevent the activation of EBV lytic cycle, which is instead triggered by TERT silencing. As lytic infection promotes the death of EBV-positive tumor cells, understanding the mechanism(s) by which TERT affects the latent/lytic status of EBV may be important for setting new therapeutic strategies. BATF, a transcription factor activated by NOTCH2, the major NOTCH family member in B cells, negatively affects the expression of BZLF1, the master regulator of viral lytic cycle. We therefore analyzed the interplay between TERT, NOTCH and BATF in LCLs and found that high levels of endogenous TERT are associated with high NOTCH2 and BATF expression levels. In addition, ectopic expression of TERT in LCLs with low levels of endogenous telomerase was associated with upregulation of NOTCH2 and BATF at both mRNA and protein levels. By contrast, infection of LCLs with retroviral vectors expressing functional NOTCH2 did not alter TERT transcript levels. Luciferase reporter assays, demonstrated that TERT significantly activated NOTCH2 promoter in a dose-dependent manner. We also found that NF-κB pathway is involved in TERT-induced NOTCH2 activation. Lastly, pharmacologic inhibition of NOTCH signaling triggers the EBV lytic cycle, leading to the death of EBV-infected cells. Overall, these results indicate that TERT contributes to preserve EBV latency in B cells mainly through the NOTCH2/BAFT pathway, and suggest that NOTCH2 inhibition may represent an appealing therapeutic strategy against EBV-associated malignancies.

  12. Role of protein kinase C in TBT-induced inhibition of lytic function and MAPK activation in human natural killer cells.

    Science.gov (United States)

    Abraha, Abraham B; Rana, Krupa; Whalen, Margaret M

    2010-11-01

    Human natural killer (NK) cells are lymphocytes that destroy tumor and virally infected cells. Previous studies have shown that exposure of NK cells to tributyltin (TBT) greatly diminishes their ability to destroy tumor cells (lytic function) while activating mitogen-activated protein kinases (MAPK) (p44/42, p38, and JNK) in NK cells. The signaling pathway that regulates NK lytic function appears to include activation of protein kinase C(PKC) as well as MAPK activity. TBT-induced activation of MAPKs would trigger a portion of the NK lytic signaling pathway, which would then leave the NK cell unable to trigger this pathway in response to a subsequent encounter with a target cell. In the present study we evaluated the involvement of PKC in inhibition of NK lysis of tumor cells and activation of MAPKs caused by TBT exposure. TBT caused a 2–3-fold activation of PKC at concentrations ranging from 50 to 300 nM (16–98 ng/ml),indicating that activation of PKC occurs in response to TBT exposure. This would then leave the NK cell unable to respond to targets. Treatment with the PKC inhibitor, bisindolylmaleimide I, caused an 85% decrease in the ability of NK cells to lyse tumor cells, validating the involvement of PKC in the lytic signaling pathway. The role of PKC in the activation of MAPKs by TBT was also investigated using bisindolylmaleimide I. The results indicated that, in NK cells where PKC activation was blocked, there was no activation of the MAPK, p44/42 in response to TBT.However, TBT-induced activation of the MAPKs, p38 and JNK did not require PKC activation. These results indicate the pivotal role of PKC in the TBT-induced loss of NK lytic function including activation of p44/42 by TBT in NK cells.

  13. Soil:An Extreme Habitat for Microorganisms?

    Institute of Scientific and Technical Information of China (English)

    M.BOLTER

    2004-01-01

    The question is asked whether soils can be regarded as extreme environments with respect to microorganisms. After defining some extreme environments in a general sense, special properties of extreme environments are compared to soil habitats, with special emphasis laid on time frame and localities. In relation to water availability, nutrients and other properties, such places as aggregates can show properties of extreme habitats. These features, which can act at different levels of the system from the community level down to the cellular level, are summarized as stress factors. The latter,where many switches are located leading to different strategies of survival, is described as the most important one. This raises the question of how organisms have adapted to such conditions. The soil system demands a broad spectrum of adaptations and/or adjustments for a highly variable environment.The soil microorganisms'adaptation can thus be seen as the highest kind of flexibility and is more useful than any other special adaptation.

  14. [Sensitivity of surface microorganisms to disinfectants].

    Science.gov (United States)

    Krzywicka, H; Janowska, J; Tadeusiak, B

    1991-01-01

    The influence of humidity and temperature on survival of S. aureus and P. aeruginosa on the surfaces of titles, glass and blanket carriers has been estimated. The number of CFU was examined after exposure time 6 and 24 hours in temperatures of 21 degrees C, 37 degrees C and RH 35%, 95%. It was observed: 1. The important reduction of numbers of both microorganisms at temperature 37 degrees C and RH 95%, 2. The relatively high number of survival cells of P. aeruginosa on the surface of blankets at temp. 21 degrees C and RH 95%. The microorganisms on the carriers were previously kept for 24 h at temp. 21 degrees C, RH 35% and 95% and then exposed to solutions of chloramine, formalin, lysol and Sterinol (QAC). It was observed that there was a great dependence of the disinfecting effect on the degree of dessication of the surfaces. In all cases the resistance of contaminated carriers stored 24 h was higher at 95% RH than at 35% RH.

  15. Identification of periodontopathogen microorganisms by PCR technique

    Directory of Open Access Journals (Sweden)

    Milićević Radovan

    2008-01-01

    Full Text Available INTRODUCTION Periodontitis is an inflammatory disease of the supporting tissues of teeth and is a major cause of tooth loss in adults. The onset and progression of periodontal disease is attributed to the presence of elevated levels of a consortium of pathogenic bacteria. Gram negative bacteria, mainly strict anaerobes, play the major role. OBJECTIVE The present study aimed to assess the presence of the main types of microorganisms involved in the aetiopathogenesis of periodontal disease: Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Eikenella corrodens, Treponema denticola, Tanerella forsythia and Prevotella intermedia in different samples collected from the oral cavity of 90 patients diagnosed with periodontitis. METHOD Bacterial DNA detection was performed in diverse biological materials, namely in dental plaque, gingival tissue and saliva, by means of multiplex PCR, a technique that allows simultaneous identification of two different bacterial genomes. RESULTS In the dental plaque of the periodontitis patients, Treponema denticola dominated. In the gingival tissue, Tannerella forsythia and Treponema denticola were the microbiota most frequently detected, whilst in saliva Treponema denticola and Eikenella corrodens were found with the highest percentage. CONCLUSION The identification of microorganisms by multiplex PCR is specific and sensitive. Rapid and precise assessment of different types of periodontopathogens is extremely important for early detection of the infection and consequently for the prevention and treatment of periodontal disease. In everyday clinical practice, for routine bacterial evaluation in patients with periodontal disease, the dental plaque is the most suitable biological material, because it is the richest in periodontal bacteria.

  16. Bioremediation of trinitrotolulene by a ruminal microorganism

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Taejin; Williamson, K.J.; Craig, A.M. [Oregon State Univ., Corvallis, OR (United States)

    1995-10-01

    2,4,6-trinitrotoluene (TNT) has been widely used for the production of explosives because of its low boiling point, high stability, low impact sensitivity, and safe manufacture. More than 1,100 military facilities, each potentially contaminated with munitions waste, are expected to require treatment of more than one million cubic yards of contaminated soils. The cost associated with remediation of these sites has been estimated to be in excess of $1.5 billion. Recently, researchers have studied ruminal microorganisms in relation to their ability to degrade xenobiotic compounds. Many of these organisms are strict anaerobes with optimal redox potentials as low as -420 mV. Ruminal organisms have been shown capable of destroying some pesticides, such as parathion, p-nitrophenol, and biphenyl-type compounds; thiono isomers, and nitrogen-containing heterocyclic plant toxins such as the pyrrolizidine alkaloids. Many of these compounds have structures similar to TNT. A TNT-degrading ruminal microorganism has been isolated from goat rumen fluid with successive enrichments on triaminotoluene (TAT) and TNT. The isolate, designated G.8, utilizes nitrate and lactate as the primary energy source. G.8 was able to tolerate and metabolite levels of TNT up to the saturation point of 125 mg/l.

  17. From chemosensing in microorganisms to practical biosensors.

    Science.gov (United States)

    Ghosh, Surya K; Kundu, Tapanendu; Sain, Anirban

    2012-11-01

    Microorganisms like bacteria can sense concentrations of chemoattractants in their medium very accurately. They achieve this through interaction between the receptors on their cell surfaces and chemoattractant molecules (like sugar). Physical processes like diffusion set some limits on the accuracy of detection, which was discussed by Berg and Purcell in the late seventies. We re-examine their work in order to assess what insight it may offer for making efficient, practical biosensors. We model the functioning of a typical biosensor as a reaction-diffusion process in a confined geometry. Using available data first we characterize the system by estimating the kinetic constants for the binding and unbinding reactions between the chemoattractants and the receptors. Then we compute the binding flux for this system, which Berg and Purcell had discussed. Unlike in microorganisms where the interval between successive measurements determines the efficiency of the nutrient searching process, it turns out that biosensors depend on long time properties like signal saturation time, which we study in detail. We also develop a mean field description of the kinetics of the system.

  18. Treatment of landfill leachate by immobilized microorganisms

    Institute of Scientific and Technical Information of China (English)

    YE ZhengFang; YU HongYan; WEN LiLi; NI JinRen

    2008-01-01

    This paper focuses on the outcome and the main performance of the immobilized microbial that treats landfill leachate. Based on the analysis of COD and ammonia-nitrogen of the influent and effluent, research was done on the high removal efficiency of COD and ammonium nitrogen by immobilized microbial. The leachate composition was analyzed qualitatively using GC-MS before and after being treated. Biological loading of efficient microbial flora on the carrier was measured by Kjeldahl's method. Finally, the patterns of immobilized microbe were observed through scanning electron microscopy (SEM). The results showed that in immobilized microorganisms system, the efficiencies of COD and nitrogen were 98.3% and 99.9%, respectively. There was a great reduction of organic components in effluent. When the immobilized biomass on the carrier was 38 g·L-1 (H2O), the filamentous microorganism was highly developed. There was no inhibitory effect on the nitrobacteria and nitrococcus, when ammonia was over 200 mg·L-1 and NH3 over 150 mg·L-1, At a high organic loading, it still had good nitrification. This paper also compares the performance of immobilized microbial with free microbial under the same condition. The immobilized microbial technology demonstrated better than the latter in all aspects.

  19. Treatment of landfill leachate by immobilized microorganisms

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper focuses on the outcome and the main performance of the immobilized microbial that treats landfill leachate. Based on the analysis of COD and ammonia-nitrogen of the influent and effluent, research was done on the high removal efficiency of COD and ammonium nitrogen by immobilized microbial. The leachate composition was analyzed qualitatively using GC-MS before and after being treated. Biological loading of efficient microbial flora on the carrier was measured by Kjeldahl’s method. Finally, the patterns of immobilized microbe were observed through scanning electron microscopy (SEM). The results showed that in immobilized microorganisms system, the efficiencies of COD and nitrogen were 98.3% and 99.9%, respectively. There was a great reduction of organic components in effluent. When the immobilized biomass on the carrier was 38 g·L?1 (H2O), the filamentous microorganism was highly developed. There was no inhibitory effect on the nitrobacteria and nitrococcus, when ammonia was over 200 mg·L?1 and NH3 over 150 mg·L?1. At a high organic loading, it still had good nitrification. This paper also compares the performance of immobilized microbial with free microbial under the same condition. The immobilized microbial technology demonstrated better than the latter in all aspects.

  20. Microorganisms as bioindicators of pollutants in soil

    Directory of Open Access Journals (Sweden)

    Milošević Nada

    2010-01-01

    Full Text Available Microorganisms are the predominant portion of the soil's biological phase and they are indicators of soil health and quality. Soil microorganisms a take part in degradation of organic and inorganic compounds, b their activity, number and diversity may serve as bioindicators of toxic effects on soil biological activity, c some microbial species may be used for soil bioremediation and d some sensitive microbes are used in eco-toxicity tests. The primary microbial population starts to decompose herbicides several days after their arrival into the soil. The secondary population produces induced enzymes and decomposes herbicides after a period of adaptation. Certain microbial groups are indifferent to the applied herbicides. Effect of heavy metals on soil microbial activity depends on the element, their concentration, microbial species, as well as physical and chemical soil properties. Toxic level of individual pollutants depends on their origin and composition. However, combined application of chemicals makes room for the occurrence of synergistic toxic effects detrimental for the ecosystem and human health. .

  1. [Rapid and efficient extraction of soluble proteins from gram-negative microorganisms without disruption of cell walls].

    Science.gov (United States)

    Danilevich, V N; Petrovskaia, L E; Grishin, E V

    2006-01-01

    The ability of buffer solutions containing low concentrations of nonionic detergents (Triton X-100, Tween 20, Brij 58, and Lubrol PX) and the anionic detergent sodium deoxycholate, as well as mixtures of these detergents with chaeotropes (urea and guanidine hydrochloride), to extract intracellular proteins of Gram-negative microorganisms (Escherichia coli and Pseudomonas aeruginosa) was studied. It was established that the solutions containing Triton X-100 and sodium deoxycholate and the mixtures of these detergents with urea are the most effective. It was shown that the extraction of proteins from bacterial cells under the studied conditions is not accompanied by a release of DNA into solution but is associated with extraction of low-molecular RNAs. The level of protein extraction reaches 80%. No disruption of the bacterial cell wall occurs during the extraction, and proteins probably permeate through meshes of the murein network. The efficiencies of our buffer mixtures are close to or higher than that of the commercial reagent CelLytic B (Sigma, United States). The practical uses of the chaeotropic mixtures developed are discussed.

  2. Abortive lytic Epstein–Barr virus replication in tonsil-B lymphocytes in infectious mononucleosis and a subset of the chronic fatigue syndrome

    Directory of Open Access Journals (Sweden)

    Lerner AM

    2012-11-01

    Full Text Available A Martin Lerner,1 Safedin Beqaj21Department of Medicine, Oakland University William Beaumont School of Medicine, Rochester, MI, USA; 2Pathology Inc, Torrance, CA, USAAbstract: A systematic 2001–2007 review of 142 chronic fatigue syndrome (CFS patients identified 106 CFS patients with elevated serum IgG antibodies to the herpesviruses Epstein–Barr virus (EBV, cytomegalovirus, or human herpesvirus (HHV 6 in single or multiple infections, with no other co-infections detected. We named these 106 patients group-A CFS. Eighty-six of these 106 group-A CFS patients (81% had elevated EBV early antibody, early antigen (diffuse, serum titers. A small group of six patients in the group-A EBV subset of CFS, additionally, had repetitive elevated-serum titers of antibody to the early lytic replication-encoded proteins, EBV dUTPase, and EBV DNA polymerase. The presence of these serum antibodies to EBV dUTPase and EBV DNA polymerase indicated EBV abortive lytic replication in these 6 CFS patients. None of 20 random control people (age- and sex-matched, with blood drawn at a commercial laboratory had elevated serum titers of antibody to EBV dUTPase or EBV DNA polymerase (P < 0.01. This finding needs verification in a larger group of EBV CFS subset patients, but if corroborated, it may represent a molecular marker for diagnosing the EBV subset of CFS. We review evidence that EBV abortive lytic replication with unassembled viral proteins in the blood may be the same in infectious mononucleosis (IM and a subset of CFS. EBV-abortive lytic replication in tonsil plasma cells is dominant in IM. No complete lytic virion is in the blood of IM or CFS patients. Complications of CFS and IM include cardiomyopathy and encephalopathy. Circulating abortive lytic-encoded EBV proteins (eg, EBV dUTPase, EBV DNA polymerase, and others may be common to IM and CFS. The intensity and duration of the circulating EBV-encoded proteins might differentiate the IM and EBV subsets of CFS

  3. System for identification of microorganism and detection of infectious disorder

    DEFF Research Database (Denmark)

    2013-01-01

    Methods for the identification of microorganisms or infectious disorders are disclosed, comprising obtaining a suitable sample from sources such as persons, animals, plants, food, water or soil. The methods also comprise providing tailored nucleic acid substrate(s) designed to react with a type 1...... topoisomerase from one or more microorganism(s) or infectious agent(s), and incubating said substrate with said sample, or extracts or preparations from the sample, so that the substrate is processed by said topoisomerase if said microorganism(s) or infectious agent(s) is present in the sample. Finally......, processed substrates are identified and potentially quantified by one or more of a range of standard molecular biology methods and read-out systems. The identification and potential quantification of microorganisms and infectious agents, including but not limited to Plasmodium falciparum and Mycobacterium...

  4. Itaconic Acid Production by Microorganisms: A Review

    Directory of Open Access Journals (Sweden)

    Helia Hajian

    2015-04-01

    Full Text Available Itaconic acid (C5H6O4 is an organic acid with unique structure and characteristics. In order to promote the bio-based economy, the US-Department of Energy (DOE assigned a “top-12” of platform chemicals, which include numerous of organic acids. In particular di-carboxylic acids, like itaconic acid, can be used as monomers for bio-polymers. Thus the need to produce itaconic acid attracts much attention. The favored production process is fermentation of carbohydrates by fungi and Aspergillus terreus is the mostly frequently employed commercial producer of itaconic acid. This review reports the current status of use of microorganisms in enhancing productivity.

  5. Laboratory studies of ocean mixing by microorganisms

    Science.gov (United States)

    Martinez-Ortiz, Monica; Dabiri, John O.

    2011-11-01

    Ocean mixing plays a major role in nutrient and energy transport and is an important input to climate models. Recent studies suggest that the contribution of fluid transport by swimming microorganisms to ocean mixing may be of the same order of magnitude as winds and tides. An experimental setup has been designed in order to study the mixing efficiency of vertical migration of plankton. To this end, a stratified water column is created to model the ocean's density gradient. The vertical migration of Artemia Salina (brine shrimp) within the water column is controlled via luminescent signals on the top and bottom of the column. By fluorescently labelling portions of the water column, the stirring of the density gradient by the animals is visualized and quantified. Preliminary results show that the vertical movement of these organisms produces enhanced mixing relative to control cases in which only buoyancy forces and diffusion are present.

  6. POLYPEPTIDE AND POLYSACCHARIDE PROCESSING IN HYPERTHERMOPHILIC MICROORGANISMS

    Energy Technology Data Exchange (ETDEWEB)

    KELLY, ROBERT M.

    2008-12-22

    This project focused on the microbial physiology and biochemistry of heterotrophic hyperthermophiles with respect to mechanisms by which these organisms process polypeptides and polysaccharides under normal and stressed conditions. Emphasis is on two model organisms, for which completed genome sequences are available: Pyrococcus furiosus (growth Topt of 98°C), an archaeon, and Thermotoga maritima (growth Topt of 80°C), a bacterium. Both organisms are obligately anaerobic heterotrophs that reduce sulfur facultatively. Whole genome cDNA spotted microarrays were used to follow transcriptional response to a variety of environmental conditions in order to identify genes encoding proteins involved in the acquisition, synthesis, processing and utilization of polypeptides and polysaccharides. This project provided new insights into the physiological aspects of hyperthermophiles as these relate to microbial biochemistry and biological function in high temperature habitats. The capacity of these microorganisms to produce biohydrogen from renewable feedstocks makes them important for future efforts to develop biofuels.

  7. Microorganism billiards in closed plane curves

    CERN Document Server

    Krieger, Madison S

    2016-01-01

    Recent experiments have shown that many species of microorganisms leave a solid surface at a fixed angle determined by steric interactions and near-field hydrodynamics. This angle is completely independent of the incoming angle. For several collisions in a closed body this determines a unique type of billiard system, an aspecular billiard in which the outgoing angle is fixed for all collisions. We analyze such a system using numerical simulation of this billiard for varying tables and outgoing angles, and also utilize the theory of one-dimensional maps and wavefront dynamics. When applicable we cite results from and compare our system to similar billiard systems in the literature. We focus on examples from three broad classes: the ellipse, the Bunimovich billiards, and the Sinai billiards. The effect of a noisy outgoing angle is also discussed.

  8. Role of effective microorganism in unfertile soil

    Directory of Open Access Journals (Sweden)

    Yasotha Chandramohan

    2014-03-01

    Full Text Available The present study was conducted to evaluvate the effect of Effective microorganisms (EM.The EM isolation is very important for agricultural fields. For this study used the different kinds of natural ingrediends such as banana, papaya, pumpkin, egg, cane molasses and neem powder to added and mixed and wait for the fermentation. After 45 days the samples were collected.The collected sample were identified using plating technique, microscopic studies and Biochemical test. The identified effective organism was Bacillus megaterium. These Effective organisms acting against the pathogen. The results concluded miximum zone of inhibition against the pathogen Such as E.coil (16mm, P.aeruginosa (18mm, K.pneumoniae (19mm, S.aureus (17mm, S.epidermis (16mm

  9. Pathogenic microorganisms of medicinal herbal drugs

    Directory of Open Access Journals (Sweden)

    Stević Tatjana

    2012-01-01

    Full Text Available All the parts of plants (root, leaf, flower naturally have a high level of microorganisms, bacteria and fungi, especially molds. Microbial contamination could be a result of inappropriate harvesting, cleaning of the raw plant material, unhygienic processing of the plants, unsuitable transport and storage. After examination of over 40 dried medicinal plant species, the lowest microbial quality was determined for Maydis stigma, Mentha leaf and herb, Equisetum herb, Calendula flower, Urtica leaf, Melissa leaf, Serpylli herb, Chamomilla flower etc. Although mixed infections are recorded with different types of fungus, Fusarium was observed as the most dominant genus in most of the tested drugs, followed by Aspergillus and Alternaria. In addition to these fungi species from the following genera were identified: Phoma, Cephalosporium, Nigrospora, Cladosporium, Epicoccum, Gliocladium, Myrothecium, Cercospora, Phomopsis, Verticillium, Dreschlera (=Bipolaris, Rhizoctonia, Septoria, Trichoderma, Curvularia, Stachybotrys, Trichothecium, Puccinia, Botrytis, Mucor and Rhizopus sp., depending on plant species.

  10. Genetic engineering of microorganisms for biodiesel production.

    Science.gov (United States)

    Lin, Hui; Wang, Qun; Shen, Qi; Zhan, Jumei; Zhao, Yuhua

    2013-01-01

    Biodiesel, as one type of renewable energy, is an ideal substitute for petroleum-based diesel fuel and is usually made from triacylglycerides by transesterification with alcohols. Biodiesel production based on microbial fermentation aiming to establish more efficient, less-cost and sustainable biodiesel production strategies is under current investigation by various start-up biotechnology companies and research centers. Genetic engineering plays a key role in the transformation of microbes into the desired cell factories with high efficiency of biodiesel production. Here, we present an overview of principal microorganisms used in the microbial biodiesel production and recent advances in metabolic engineering for the modification required. Overexpression or deletion of the related enzymes for de novo synthesis of biodiesel is highlighted with relevant examples.

  11. Feeding, Swimming and Navigation of Colonial Microorganisms

    Science.gov (United States)

    Kirkegaard, Julius; Bouillant, Ambre; Marron, Alan; Leptos, Kyriacos; Goldstein, Raymond

    2016-11-01

    Animals are multicellular in nature, but evolved from unicellular organisms. In the closest relatives of animals, the choanoflagellates, the unicellular species Salpincgoeca rosetta has the ability to form colonies, resembling true multicellularity. In this work we use a combination of experiments, theory, and simulations to understand the physical differences that arise from feeding, swimming and navigating as colonies instead of as single cells. We show that the feeding efficiency decreases with colony size for distinct reasons in the small and large Péclet number limits, and we find that swimming as a colony changes the conventional active random walks of microorganism to stochastic helices, but that this does not hinder effective navigation towards chemoattractants.

  12. Petroleum pollutant degradation by surface water microorganisms.

    Science.gov (United States)

    Antić, Malisa P; Jovancićević, Branimir S; Ilić, Mila; Vrvić, Miroslav M; Schwarzbauer, Jan

    2006-09-01

    It is well known that the composition of petroleum or some of its processing products changes in the environment mostly under the influence of microorganisms. A series of experiments was conducted in order to define the optimum conditions for an efficient biodegradation of petroleum pollutant, or bioremediation of different segments of the environment. The aim of these investigations was to show to what extent the hydrocarbons of a petroleum pollutant are degraded by microbial cultures which were isolated as dominant microorganisms from a surface water of a wastewater canal of an oil refinery and a nitrogen plant. Biodegradation experiments were conducted on one paraffinic, and one naphthenic type of petroleum during a three month period under aerobic conditions, varying the following parameters: Inorganic (Kp) or an organic medium (Bh) with or without exposition to light. Microorganisms were analyzed in a surface water sample from a canal (Pancevo, Serbia), into which wastewater from an oil refinery and a nitrogen plant is released. The consortia of microorganisms were isolated from the water sample (most abundant species: Phormidium foveolarum--filamentous Cyanobacteria, blue-green algae and Achanthes minutissima, diatoms, algae). The simulation experiments of biodegradation were conducted with the biomass suspension and crude oils Sirakovo (Sir, paraffinic type) and Velebit (Ve, naphthenic type). After a three month period, organic substance was extracted by means of chloroform. In the extracts, the content of saturated hydrocarbons, aromatic hydrocarbons, alcohols and fatty acids was determined (the group composition). n-Alkanes and isoprenoid aliphatic alkanes, pristane and phytane, in the aliphatic fractions, were analyzed using gas chromatography (GC). Total isoprenoid aliphatic alkanes and polycyclic alkanes of sterane and triterpane types were analyzed by GC-MS. Paraffinic type petroleums have a significant loss of saturated hydrocarbons. For naphthenic

  13. Putative ancient microorganisms from amber nuggets.

    Science.gov (United States)

    Veiga-Crespo, Patricia; Blasco, Lucía; Poza, Margarita; Villa, Tomás G

    2007-06-01

    Evolutionary microbiology studies based on the isolation of ancient DNA and/or microbial samples are scarce due to the difficulty of finding well preserved biological specimens. However, amber is a fossil resin with natural preserving properties for microbial cells and DNA. The visualization by transmission electron microscopy of different microorganism-like specimens found in amber nuggets from both the Miocene and the Cretaceous periods was accompanied by studies of ancient DNA obtained from the nuggets. After the design of specific primers based on the present sequences of both genes in Saccharomyces cerevisiae, the ancestral AGP2 sequence from the Miocene, as well as the 18S rRNA from the Cretaceous, were amplified.

  14. Climate change effects on beneficial plant-microorganism interactions

    OpenAIRE

    Compant, Stéphane; van der Heijden, Marcel G. A.; Sessitsch, Angela

    2017-01-01

    It is well known that beneficial plant-associated microorganisms may stimulate plant growth and enhance resistance to disease and abiotic stresses. The effects of climate change factors such as elevated CO2, drought and warming on beneficial plant-microorganism interactions are increasingly being explored. This now makes it possible to test whether some general patterns occur and whether different groups of plant-associated microorganisms respond differently or in the same way to climate chan...

  15. Safety Assessment of Foods Derived from Genetically Modified Microorganisms

    OpenAIRE

    Schlundt, J.

    2011-01-01

    Microorganisms have a long history of use in food production, e.g. in the production of sausages, cheeses, etc. Roughly one quarter of all food products rely on microbiological processes, and the safe use of microorganisms for food production is essential. The transfer of novel traits to food microorganisms through recombinant gene technology will result in new potential food safety issues. This requires the elaboration of criteria for safety assessment of foods derived from genetic microorga...

  16. Enhancement of uranium-accumulating ability of microorganisms by irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sakaguchi, Takashi; Nakajima, Akira; Tsuruta, Takehiko [Miyazaki Medical Coll., Kiyotake (Japan)

    1998-01-01

    Some microorganisms having excellent ability to accumulate uranium were isolated, from soil and water systems in and around the Ningyo-toge Station of Power Reactor and Nuclear Fuel Development Corporation. The enhancement of uranium-accumulating ability of microorganisms by electron-beam irradiation was examined, and the ability of JW-046 was increased 3-5% by the irradiation. The irradiation affect the growth of some of microorganisms tested. (author)

  17. Radiation resistance of microorganisms on unsterilized infusion sets

    DEFF Research Database (Denmark)

    Christensen, E. Ahrensburg; Kristensen, H.; Hoborn, J.;

    1991-01-01

    Three different methods were used for detecting and isolating microorganisms with high radiation resistance from the microbial contamination on infusion sets prior to sterilization. By all three methods, microorganisms with a radiation resistance high enough to be a critical factor in a steriliza......Three different methods were used for detecting and isolating microorganisms with high radiation resistance from the microbial contamination on infusion sets prior to sterilization. By all three methods, microorganisms with a radiation resistance high enough to be a critical factor...

  18. Biosynthesis of Nanoparticles by Microorganisms and Their Applications

    National Research Council Canada - National Science Library

    Li, Xiangqian; Xu, Huizhong; Chen, Zhe-Sheng; Chen, Guofang

    2011-01-01

    .... Nowadays, a variety of inorganic nanoparticles with well-defined chemical composition, size, and morphology have been synthesized by using different microorganisms, and their applications in many...

  19. Collective motion of micro-organisms from field theoretical viewpoint

    CERN Document Server

    Kawamura, M; Kawamura, Masako; Sugamoto, Akio

    1995-01-01

    We analyze the collective motion of micro-organisms in the fluid and consider the problem of the red tide. The red tide is produced by the condensation of the micro-organisms, which might be a similar phenomenon to the condensation of the strings. We propose a model of the generation of the red tide. By considering the interaction between the micro-organisms mediated by the velocity fields in the fluid, we derive the Van der Waals type equation of state, where the generation of the red tide can be regarded as a phase transition from the gas of micro-organisms to the liquid.

  20. The ecology of micro-organisms in a closed environment

    Science.gov (United States)

    Fox, L.

    1971-01-01

    Microorganisms under closed environmental ecological conditions with reference to astronauts infectious diseases, discussing bacteria growth in Biosatellite 2 and earth based closed chamber experiments

  1. Analysis of Membrane Lipids of Airborne Micro-Organisms

    Science.gov (United States)

    MacNaughton, Sarah

    2006-01-01

    A method of characterization of airborne micro-organisms in a given location involves (1) large-volume filtration of air onto glass-fiber filters; (2) accelerated extraction of membrane lipids of the collected micro-organisms by use of pressurized hot liquid; and (3) identification and quantitation of the lipids by use of gas chromatography and mass spectrometry. This method is suitable for use in both outdoor and indoor environments; for example, it can be used to measure airborne microbial contamination in buildings ("sick-building syndrome"). The classical approach to analysis of airborne micro-organisms is based on the growth of cultureable micro-organisms and does not provide an account of viable but noncultureable micro-organisms, which typically amount to more than 90 percent of the micro-organisms present. In contrast, the present method provides an account of all micro-organisms, including cultureable, noncultureable, aerobic, and anaerobic ones. The analysis of lipids according to this method makes it possible to estimate the number of viable airborne micro-organisms present in the sampled air and to obtain a quantitative profile of the general types of micro-organisms present along with some information about their physiological statuses.

  2. Posterior lumbar interbody fusion for lytic spondylolisthesis: restoration of sagittal balance using insert-and-rotate interbody spacers.

    Science.gov (United States)

    Sears, William

    2005-01-01

    The role of surgical correction of sagittal plane deformity in cases of lytic spondylolisthesis remains controversial. While some early evidence is emerging of the possible short- and long-term benefits of restoring spinal balance, many surgeons have been concerned about the associated risks. The insert-and-rotate posterior lumbar interbody fusion (PLIF) technique, first described by Jaslow in 1946, may enable surgeons to safely and effectively correct sagittal balance through a single posterior approach. To determine whether the focal kyphosis and subluxation associated with a lytic lumbosacral spondylolisthesis can be safely and effectively corrected using a single-stage posterior distraction/reduction technique and insert-and-rotate interbody fusion spacers. A prospective, single cohort, observational study of the clinical outcomes and retrospective radiological review, in a series of 18 consecutive patients with lytic spondylolisthesis Grades I to IV, operated between September 2000 and December 2002. Mean age of 50.2 years (range, 15.5 to 77.8 years). Principal indication for surgery was relief of radicular pain secondary to foraminal stenosis in 16 of 18 patients, and back pain was the principal symptom in 2 patients. Mean preoperative slip was 30.2% (range, 9% to 78%). Mean preoperative focal lordosis was 10.6 degrees (range, -12 to 33 degrees). Minimum 12-month follow-up was available on all patients except one, who died of unrelated causes after his 6-month visit. Patients completed Visual Analogue Pain Score (VAS), Low Back Outcome Score (LBOS), Short Form (SF)-12 and patient satisfaction questionnaires. Pre- and postoperative measurements of the percentage slip and lumbar lordosis of the involved segments were available on 13 patients. SURGICAL METHODS: Decompressive laminectomy was followed by reduction of the spondylolisthesis with the aid of intervertebral disc space spreaders and supplementary pedicle screw instrumentation. The vertebral bodies were

  3. Human Herpesvirus 6B Downregulates Expression of Activating Ligands during Lytic Infection To Escape Elimination by Natural Killer Cells.

    Science.gov (United States)

    Schmiedel, Dominik; Tai, Julie; Levi-Schaffer, Francesca; Dovrat, Sarah; Mandelboim, Ofer

    2016-11-01

    The Herpesviridae family consists of eight viruses, most of which infect a majority of the human population. One of the less-studied members is human herpesvirus 6 (HHV-6) (Roseolovirus), which causes a mild, well-characterized childhood disease. Primary HHV-6 infection is followed by lifelong latency. Reactivation frequently occurs in immunocompromised patients, such as those suffering from HIV infection or cancer or following transplantation, and causes potentially life-threatening complications. In this study, we investigated the mechanisms that HHV-6 utilizes to remain undetected by natural killer (NK) cells, which are key participants in the innate immune response to infections. We revealed viral mechanisms which downregulate ligands for two powerful activating NK cell receptors: ULBP1, ULBP3, and MICB, which trigger NKG2D, and B7-H6, which activates NKp30. Accordingly, this downregulation impaired the ability of NK cells to recognize HHV-6-infected cells. Thus, we describe for the first time immune evasion mechanisms of HHV-6 that protect lytically infected cells from NK elimination. Human herpesvirus 6 (HHV-6) latently infects a large portion of the human population and can reactivate in humans lacking a functional immune system, such as cancer or AIDS patients. Under these conditions, it can cause life-threatening diseases. To date, the actions and interplay of immune cells, and particularly cells of the innate immune system, during HHV-6 infection are poorly defined. In this study, we aimed to understand how cells undergoing lytic HHV-6 infection interact with natural killer (NK) cells, innate lymphocytes constituting the first line of defense against viral intruders. We show that HHV-6 suppresses the expression of surface proteins that alert the immune cells by triggering two major receptors on NK cells, NKG2D and NKp30. As a consequence, HHV-6 can replicate undetected by the innate immune system and potentially spread infection throughout the body. This

  4. Antibodies against lytic and latent Kaposi's sarcoma-associated herpes virus antigens and lymphoma in the European EpiLymph case–control study

    Science.gov (United States)

    Benavente, Y; Mbisa, G; Labo, N; Casabonne, D; Becker, N; Maynadie, M; Foretova, L; Cocco, P L; Nieters, A; Staines, A; Bofetta, P; Brennan, P; Whitby, D; de Sanjosé, S

    2011-01-01

    Background: Kaposi's sarcoma-associated herpes virus is associated with primary effusion lymphoma and multicentric Castleman's disease. Methods: Seropositivity to lytic and latent Kaposi's sarcoma herpes virus (KSHV) antigens were examined in 2083 lymphomas and 2013 controls from six European countries. Results: Antibodies against KSHV latent and lytic antigens were detectable in 4.5% and 3.4% of controls, respectively, and 3.6% of cases (P>0.05). The KSHV seropositivity was associated with splenic marginal zone lymphoma (SMZL) (odds ratio (OR)=4.11, 95% confidence interval (CI)=1.57–10.83) and multiple myeloma (OR=0.31, 95% CI=0.11–0.85). Conclusion: The KSHV is unlikely to contribute importantly to lymphomagenesis among immunocompetent subjects. However, the observed association with SMZL may underline a chronic antigen mechanism in its aetiology. PMID:21952625

  5. Protein expression on Cr resistant microorganism using electrophoresis method

    Directory of Open Access Journals (Sweden)

    SAJIDAN

    2009-01-01

    Full Text Available Fatmawati U, Suranto, Sajidan. 2009. Protein expression on Cr resistant microorganism using electrophoresis method. Nusantara Bioscience 1: 31-37. Hexavalent chromium (Cr(VI is known as toxic heavy metals, so the need is reduced to Cr(III is much less toxicity. Pseudomonas aeruginosa, Pseudomonas putida, Klebsiella pneumoniae, Pantoea sp. and Saccharomyces cerevisiae are resistant Cr(VI microorganism and have ability to reduce Cr(VI. The aim of this research is to know ability of microorganism to reduce Cr(VI and to know protein band pattern between Cr(VI resistant microorganism and non resistant microorganism which inoculated on LB broth. SDS-PAGE was used to indentify protein expression. While, Cr(VI concentration was identified by 1.5 diphenylcarbazide method. The quantitative data was analyzed by two factorial ANOVA that continued with DMRT at 1% level test. The qualitative data i.e. protein expression analyzed by relative mobility (Rf. The results showed that the ability of microorganisms to reduce Cr(VI at initial concentration of 0.5 ppm, 1 ppm, 5 ppm and 10 ppm may vary, the average percentage of the ability of each microorganism in reducing Cr(VI is P. putida (65% > S. cerevisiae (64.45% >. P. aeruginosa (60.73% > Pantoea sp. (50.22% > K. pneumoniae (47.82% > without microorganisms (34.25%. The adding microorganisms have significantly influenced toward reduction of Cr(VI. The SDS-PAGE shows that protein expression between resistant and not resistant microorganisms are no different, but resistant microorganisms have more protein (protein band is thicker.

  6. Kaposi's Sarcoma-Associated Herpesvirus K-bZIP Protein Is Necessary for Lytic Viral Gene Expression, DNA Replication, and Virion Production in Primary Effusion Lymphoma Cell Lines▿ †

    OpenAIRE

    Lefort, Sylvain; Flamand, Louis

    2009-01-01

    Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of three human proliferative disorders, namely, Kaposi's sarcoma, primary effusion lymphomas (PEL), and multicentric Castleman's disease. Lytic DNA replication of KSHV, which is essential for viral propagation, requires the binding of at least two KSHV proteins, replication and transactivation activator (RTA) and K-bZIP, on the lytic origin of replication. Moreover, K-bZIP physically interacts with RTA and represses its tra...

  7. Nitrogen utilization pathways of soil microorganisms

    Science.gov (United States)

    Pinggera, J.; Geisseler, D.; Merbach, I.; Ludwig, B.

    2012-04-01

    Nitrogen (N) is an essential nutrient for all organisms. In terrestrial ecosystems N occurs predominantly in the form of organic matter. Here, soil microorganisms can use two possible mechanisms for the uptake of organic N: the direct route and the mobilization-immobilization-turnover (MIT) route. In the direct route simple organic molecules are taken up directly into the cell. The deamination occurs inside the cell and only the surplus N is released into the soil solution. In the second route, the deamination occurs outside the cell and all N is mineralized before assimilation. To determine the importance of the different N uptake pathways of soil microorganisms an incubation experiment (21 days, 20°C) is currently being carried out. Corn leaves with different C to N ratios (20, 40) and (NH4)2SO4 have been added to three soils (Haplic Chernozem, FAO) with different fertilization histories (300dt/ha farmyard manure every second year, mineral NPK fertilizer, no fertilization) from the long-term experiment at Bad Lauchstädt. Contents of NH4+, NO3- and microbial biomass C (Cmic) and N (Nmic), CO2 production, potential protease activity, gross N mineralization and mineralization of added amino acids will be determined after 3, 7 and 21 days. Preliminary results show that the protease activity (without addition of corn residues) decreased in the order manure-fertilized soil (18.26 mg tyrosine kg-1 soil h-1) > Soil with mineral NPK fertilizer (17.45 mg tyrosine kg-1 soil h-1) > unfertilized soil (11.34 mg tyrosine kg-1 oven dry soil h-1). The turnover of amino acids after 24h was higher for the manure-fertilized soil (99.5% of the added amino acids were consumed) than for the NPK- fertilized and unfertilized soils (76%). The effects of the fertilization histories on the temporal dynamics of the different biological properties (Cmic, Nmic), CO2 production, protease activity and N mineralization rates will be presented.

  8. 羟基化酶产生菌Stenorophomonas maltophilia CGMCC1.1788对农药氯噻啉生物转化的条件研究%Biotransformation Conditions Optimization of Hydroxylation Enzyme Producing Bacteria Stenorophomonas maltophilia CGMCC 1.1788 to Pesticide Imidaclothiz

    Institute of Scientific and Technical Information of China (English)

    赵银娟; 袁生

    2012-01-01

    [ Objective ] The aim was to explore the transformation activity of hydroxylation enzyme from hydroxylation enzyme producing bacteria Stenorophomonas maltophilia CGMCC 1. 1788. [Method] Biotransformation conditions of hydroxylation enzyme producing bacteria S. Maltophilia CGMCC 1.1788 to pesticide imidaclothiz were optimized by using shaking flask fermentation method. [Result] The converting conditions were established as followed: the best outfit fluid volume was 10 ml per 100 ml conical flask; the best reaction temperature was 25℃; the optimum pH was 6.5; the optimum reaction substrate initial concentration was 0. 2 g/L; and the best reaction time was 48 h. [ Conclusion] The research results provide theoretical basis to play the microbial transformation function of S. Maltophilia CGMCC 1.1788 and understand the biological characteristics of hydroxylation enzyme.%[目的]探究羟基化酶产生菌Stenorophomonas maltophilia CGMCC 1.1788菌株中羟基化酶的转化活性.[方法]采用摇瓶发酵转化方法对羟基化酶产生菌S.maltophilia CGMCC 1.1788对农药氯噻啉的生物转化条件(不同生长时期的细胞、温度、pH等影响因子)进行了优化.[结果]确立了转化条件:100 ml锥形瓶最佳装液量10 ml,最佳反应温度25℃,最适pH 6.5,最佳反应底物起始浓度0.2 g/L,最佳反应时间48 h.[结论]为较好地发挥该菌的微生物转化功能及了解羟基化酶的生物学特性提供了理论依据.

  9. Isolation and characterization of glacier VMY22, a novel lytic cold-active bacteriophage of Bacillus cereus

    Institute of Scientific and Technical Information of China (English)

    Xiuling; Ji; Chunjing; Zhang; Yuan; Fang; Qi; Zhang; Lianbing; Lin; Bing; Tang; Yunlin; Wei

    2015-01-01

    As a unique ecological system with low temperature and low nutrient levels, glaciers are considered a "living fossil" for the research of evolution. In this work, a lytic cold-active bacteriophage designated VMY22 against Bacillus cereus MYB41-22 was isolated from Mingyong Glacier in China, and its characteristics were studied. Electron microscopy revealed that VMY22 has an icosahedral head(59.2 nm in length, 31.9 nm in width) and a tail(43.2 nm in length). Bacteriophage VMY22 was classified as a Podoviridae with an approximate genome size of 18 to 20 kb. A one-step growth curve revealed that the latent and the burst periods were 70 and 70 min, respectively, with an average burst size of 78 bacteriophage particles per infected cell. The pH and thermal stability of bacteriophage VMY22 were also investigated. The maximum stability of the bacteriophage was observed to be at pH 8.0 and it was comparatively stable at p H 5.0–9.0. As VMY22 is a cold-active bacteriophage with low production temperature, its characterization and the relationship between MYB41-22 and Bacillus cereus bacteriophage deserve further study.

  10. Changes in coagulation and lytic activity of the blood and tissues at the pelvic trauma during anticoagulant therapy

    Directory of Open Access Journals (Sweden)

    A. P. Vlasov

    2014-01-01

    Full Text Available The purpose of our study was exploration of coagulation and lytic activity in blood and tissues during anticoagulation therapy in the early posttraumatic period in patients with pelvic bone fracture. The study was based on experiment researches using methods allowing to estimate coagulation activity in different tissues (skeletal muscles, liver, kidneys, heart, lungs and blood at pelvic trauma during anticoagulation therapy. It was established that at pelvic trauma using anticoagulation therapy (fraxiparine leads to hemostatic system modification in the early posttraumatic period. We observed fast decrease of a hypercoagulability in a blood plasma (organism level and growth fibrinolytic activity. In liver, kidneys, heart and lungs tissues (organ level we also registered correction the hemostatic disorders. However, the rate of these recovery processes in tissues is lower than in the blood. Especially low it was in skeletal muscles in the area of injury. Thus, it is proved that anticoagulant therapy at a pelvic trauma affects on the extrinsic coagulation pathway less than on the intrinsic coagulation pathway. The established regularity explains the risks of coagulation abnormalities in the early posttraumatic period during anticoagulation treatment.

  11. Acquisition of intact polar lipids from the Prymnesiophyte Phaeocystis globosa by its lytic virus PgV-07T

    Directory of Open Access Journals (Sweden)

    D. S. Maat

    2013-07-01

    Full Text Available Recent studies showed changes in phytoplankton lipid composition during viral infection and have indicated roles for specific lipids in the mechanisms of algal virus-host interaction. To investigate the generality of these findings and obtain a better understanding of the allocation of specific lipids to viruses, we studied the intact polar lipid (IPL composition of virally infected and non-infected cultures of the Prymnesiophyte Phaeocystis globosa G(A and its lytic virus PgV-07T. The P. globosa IPL composition was relatively stable over a diel cycle and not strongly affected by viral infection. Glycolipids, phospholipids and betaine lipids were present in both the host and virus, although specific groups such as the diacylglyceryl-hydroxymethyltrimethyl-β-alanines and the sulfoquinovosyldiacylglycerols, were present in a lower proportion or were not detected in the virus. Viral glycosphingolipids (vGSLs, which have been shown to play a role in the infection strategy of the virus EhV-86, infecting the Prymnesiophyte Emiliania huxleyi CCMP374, were not encountered. Our results show that the involvement of lipids in virus-algal host interactions can be very different amongst virus-algal host systems.

  12. Cello-oligosaccharide oxidation reveals differences between two lytic polysaccharide monooxygenases (family GH61) from Podospora anserina.

    Science.gov (United States)

    Bey, Mathieu; Zhou, Simeng; Poidevin, Laetitia; Henrissat, Bernard; Coutinho, Pedro M; Berrin, Jean-Guy; Sigoillot, Jean-Claude

    2013-01-01

    The genome of the coprophilic ascomycete Podospora anserina encodes 33 different genes encoding copper-dependent lytic polysaccharide monooxygenases (LPMOs) from glycoside hydrolase family 61 (GH61). In this study, two of these enzymes (P. anserina GH61A [PaGH61A] and PaGH61B), which both harbored a family 1 carbohydrate binding module, were successfully produced in Pichia pastoris. Synergistic cooperation between PaGH61A or PaGH61B with the cellobiose dehydrogenase (CDH) of Pycnoporus cinnabarinus on cellulose resulted in the formation of oxidized and nonoxidized cello-oligosaccharides. A striking difference between PaGH61A and PaGH61B was observed through the identification of the products, among which were doubly and triply oxidized cellodextrins, which were released only by the combination of PaGH61B with CDH. The mass spectrometry fragmentation patterns of these oxidized products could be consistent with oxidation at the C-6 position with a geminal diol group. The different properties of PaGH61A and PaGH61B and their effect on the interaction with CDH are discussed in regard to the proposed in vivo function of the CDH/GH61 enzyme system in oxidative cellulose hydrolysis.

  13. Characterization of the Newly Isolated Lytic Bacteriophages KTN6 and KT28 and Their Efficacy against Pseudomonas aeruginosa Biofilm.

    Directory of Open Access Journals (Sweden)

    Katarzyna Danis-Wlodarczyk

    Full Text Available We here describe two novel lytic phages, KT28 and KTN6, infecting Pseudomonas aeruginosa, isolated from a sewage sample from an irrigated field near Wroclaw, in Poland. Both viruses show characteristic features of Pbunalikevirus genus within the Myoviridae family with respect to shape and size of head/tail, as well as LPS host receptor recognition. Genome analysis confirmed the similarity to other PB1-related phages, ranging between 48 and 96%. Pseudomonas phage KT28 has a genome size of 66,381 bp and KTN6 of 65,994 bp. The latent period, burst size, stability and host range was determined for both viruses under standard laboratory conditions. Biofilm eradication efficacy was tested on peg-lid plate assay and PET membrane surface. Significant reduction of colony forming units was observed (70-90% in 24 h to 72 h old Pseudomonas aeruginosa PAO1 biofilm cultures for both phages. Furthermore, a pyocyanin and pyoverdin reduction tests reveal that tested phages lowers the amount of both secreted dyes in 48-72 h old biofilms. Diffusion and goniometry experiments revealed the increase of diffusion rate through the biofilm matrix after phage application. These characteristics indicate these phages could be used to prevent Pseudomonas aeruginosa infections and biofilm formation. It was also shown, that PB1-related phage treatment of biofilm caused the emergence of stable phage-resistant mutants growing as small colony variants.

  14. In vitro characterization and in vivo properties of Salmonellae lytic bacteriophages isolated from free-range layers

    Directory of Open Access Journals (Sweden)

    L Fiorentin

    2004-06-01

    Full Text Available Occurrence of food poisoning related to Salmonella-contaminated eggs and chicken meat has been frequent in humans. Salmonella Enteritidis (SE and Salmonella Typhimurium (ST are included among the most important paratyphoid salmonellae associated with chicken meat and eggs. Elimination of Salmonella at the pre-harvest stage can play a significant role in preventing the introduction of this pathogen into the food chain and consequently in the reduction of food poisoning in humans. Bactericidal bacteriophages may provide a natural, nontoxic, feasible and non-expensive component of the multi-factorial approach for a pre-harvest control of Salmonella in poultry. Five bacteriophages lytic for SE PT4 and ST were obtained from 107 samples of feces of free-range layers in Brazil. All bacteriophages were characterized in vitro and in vivo, showing head and tail morphology and dsDNA as nucleic acids. Results of "in vivo" studies suggested that bacteriophages do not remain in Salmonella-free birds longer than one day, whereas they multiply in Salmonella-infected birds for longer periods. Besides, selection for phage-resistant SE PT4 did not seem to occur in the short term. Isolated bacteriophages will be investigated for their potential for pre-harvest biocontrol of SE PT4 in poultry.

  15. Characterization of the Newly Isolated Lytic Bacteriophages KTN6 and KT28 and Their Efficacy against Pseudomonas aeruginosa Biofilm.

    Science.gov (United States)

    Danis-Wlodarczyk, Katarzyna; Olszak, Tomasz; Arabski, Michal; Wasik, Slawomir; Majkowska-Skrobek, Grazyna; Augustyniak, Daria; Gula, Grzegorz; Briers, Yves; Jang, Ho Bin; Vandenheuvel, Dieter; Duda, Katarzyna Anna; Lavigne, Rob; Drulis-Kawa, Zuzanna

    2015-01-01

    We here describe two novel lytic phages, KT28 and KTN6, infecting Pseudomonas aeruginosa, isolated from a sewage sample from an irrigated field near Wroclaw, in Poland. Both viruses show characteristic features of Pbunalikevirus genus within the Myoviridae family with respect to shape and size of head/tail, as well as LPS host receptor recognition. Genome analysis confirmed the similarity to other PB1-related phages, ranging between 48 and 96%. Pseudomonas phage KT28 has a genome size of 66,381 bp and KTN6 of 65,994 bp. The latent period, burst size, stability and host range was determined for both viruses under standard laboratory conditions. Biofilm eradication efficacy was tested on peg-lid plate assay and PET membrane surface. Significant reduction of colony forming units was observed (70-90%) in 24 h to 72 h old Pseudomonas aeruginosa PAO1 biofilm cultures for both phages. Furthermore, a pyocyanin and pyoverdin reduction tests reveal that tested phages lowers the amount of both secreted dyes in 48-72 h old biofilms. Diffusion and goniometry experiments revealed the increase of diffusion rate through the biofilm matrix after phage application. These characteristics indicate these phages could be used to prevent Pseudomonas aeruginosa infections and biofilm formation. It was also shown, that PB1-related phage treatment of biofilm caused the emergence of stable phage-resistant mutants growing as small colony variants.

  16. COX-2 induces lytic reactivation of EBV through PGE2 by modulating the EP receptor signaling pathway.

    Science.gov (United States)

    Gandhi, Jaya; Gaur, Nivedita; Khera, Lohit; Kaul, Rajeev; Robertson, Erle S

    2015-10-01

    Inflammation is one of the predisposing factors known to be associated with Epstein Barr Virus (EBV) mediated tumorigenesis. However it is not well understood whether inflammation in itself plays a role in regulating the life cycle of this infectious agent. COX-2, a key mediator of the inflammatory processes is frequently over-expressed in EBV positive cancer cells. In various tumors, PGE2 is the principle COX-2 regulated downstream product which exerts its effects on cellular processes through the EP1-4 receptors. In this study, we further elucidated how upregulated COX-2 levels can modulate the events in EBV life cycle related to latency-lytic reactivation. Our data suggest a role for upregulated COX-2 on modulation of EBV latency through its downstream effector PGE2. This study demonstrates a role for increased COX-2 levels in modulation of EBV latency. This is important for understanding the pathogenesis of EBV-associated cancers in people with chronic inflammatory conditions. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. S-Layered Aneurinibacillus and Bacillus spp. Are Susceptible to the Lytic Action of Pseudomonas aeruginosa Membrane Vesicles

    Science.gov (United States)

    Kadurugamuwa, J. L.; Mayer, A.; Messner, P.; Sára, M.; Sleytr, U. B.; Beveridge, T. J.

    1998-01-01

    When S-layered strains of Bacillus stearothermophilus and Aneurinibacillus thermoaerophilus, possessing S-layers of different lattice type and lattice constant as well as S-(glyco)protein chemistry, and isogenic S-layerless variants were subjected to membrane vesicles (MVs) from P. aeruginosa during plaque assays on plates or CFU measurements on cell suspensions, all bacterial types lysed. Electron microscopy of negative stains, thin sections, and immunogold-labelled MV preparations revealed that the vesicles adhered to all bacterial surfaces, broke open, and digested the underlying peptidoglycan-containing cell wall of all cell types. Reassembled S-layer did not appear to be affected by MVs, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis showed that the S-(glyco)proteins remained intact. meso-Diaminopimelic acid, as a peptidoglycan breakdown product, was found in all culture supernatants after MV attack. These results suggest that even though MVs are much larger than the channels which penetrate these proteinaceous arrays, S-layers on gram-positive bacteria do not form a defensive barrier against the lytic action of MVs. The primary mode of attack is by the liberation from the MVs of a peptidoglycan hydrolase, which penetrates through the S-layer to digest the underlying peptidoglycan-containing cell wall. The S-layer is not affected by MV protease. PMID:9573179

  18. In vitro design of a novel lytic bacteriophage cocktail with therapeutic potential against organisms causing diabetic foot infections.

    Science.gov (United States)

    Mendes, João J; Leandro, Clara; Mottola, Carla; Barbosa, Raquel; Silva, Filipa A; Oliveira, Manuela; Vilela, Cristina L; Melo-Cristino, José; Górski, Andrzej; Pimentel, Madalena; São-José, Carlos; Cavaco-Silva, Patrícia; Garcia, Miguel

    2014-08-01

    In patients with diabetes mellitus, foot infections pose a significant risk. These are complex infections commonly caused by Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter baumannii, all of which are potentially susceptible to bacteriophages. Here, we characterized five bacteriophages that we had determined previously to have antimicrobial and wound-healing potential in chronic S. aureus, P. aeruginosa and A. baumannii infections. Morphological and genetic features indicated that the bacteriophages were lytic members of the family Myoviridae or Podoviridae and did not harbour any known bacterial virulence genes. Combinations of the bacteriophages had broad host ranges for the different target bacterial species. The activity of the bacteriophages against planktonic cells revealed effective, early killing at 4 h, followed by bacterial regrowth to pre-treatment levels by 24 h. Using metabolic activity as a measure of cell viability within established biofilms, we found significant cell impairment following bacteriophage exposure. Repeated treatment every 4 h caused a further decrease in cell activity. The greatest effects on both planktonic and biofilm cells occurred at a bacteriophage : bacterium input multiplicity of 10. These studies on both planktonic cells and established biofilms allowed us to better evaluate the effects of a high input multiplicity and a multiple-dose treatment protocol, and the findings support further clinical development of bacteriophage therapy. © 2014 The Authors.

  19. Microorganisms in processes of the destruction of oil in reservoirs

    Directory of Open Access Journals (Sweden)

    A. A. Kurapov

    2010-01-01

    Full Text Available Pollution by oil has negative influence on all ecosystem of the sea. The main role in decomposing of hydrocarbons belongs to microorganisms. Influence emulsion and water repellencies of cellular walls of microorganisms on an oil destruction is noted.

  20. Effects of heat-activated persulfate oxidation on soil microorganisms

    DEFF Research Database (Denmark)

    Tsitonaki, Aikaterini; Smets, Barth F.; Bjerg, Poul Løgstrup

    2008-01-01

    /L). The results emphasize the necessity of using multiple toxicity assays and indigenous cultures in order to realistically assess the potential effects of in situ chemical oxidation on soil microorganisms. A comparison to other studies suggests that the effects of activated persulfate on soil microorganisms...

  1. Potential applications of plant probiotic microorganisms in agriculture and forestry

    OpenAIRE

    Luciana Porto de Souza Vandenberghe; Lina Marcela Blandon Garcia; Cristine Rodrigues; Marcela Cândido Camara; Gilberto Vinícius de Melo Pereira; Juliana de Oliveira; Carlos Ricardo Soccol

    2017-01-01

    Agriculture producers, pushed by the need for high productivity, have stimulated the intensive use of pesticides and fertilizers. Unfortunately, negative effects on water, soil, and human and animal health have appeared as a consequence of this indiscriminate practice. Plant probiotic microorganisms (PPM), also known as bioprotectants, biocontrollers, biofertilizers, or biostimulants, are beneficial microorganisms that offer a promising alternative and reduce health and environmental problems...

  2. Composting MSW and sewage sludge with effective complex microorganisms

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The effects of complex microorganisms in composting process of the municipal solid waste (MSW) and sludge were examined through inspecting biomass, temperature, oxygen consumption, organic mater, and C/N (the ratio of carbon and nitrogen). The experimental results shows: complex microorganisms are effective to compose organic matter and speedup composting change into humus.

  3. Climate change effects on beneficial plant-microorganism interactions.

    Science.gov (United States)

    Compant, Stéphane; van der Heijden, Marcel G A; Sessitsch, Angela

    2010-08-01

    It is well known that beneficial plant-associated microorganisms may stimulate plant growth and enhance resistance to disease and abiotic stresses. The effects of climate change factors such as elevated CO(2), drought and warming on beneficial plant-microorganism interactions are increasingly being explored. This now makes it possible to test whether some general patterns occur and whether different groups of plant-associated microorganisms respond differently or in the same way to climate change. Here, we review the results of 135 studies investigating the effects of climate change factors on beneficial microorganisms and their interaction with host plants. The majority of studies showed that elevated CO(2) had a positive influence on the abundance of arbuscular and ectomycorrhizal fungi, whereas the effects on plant growth-promoting bacteria and endophytic fungi were more variable. In most cases, plant-associated microorganisms had a beneficial effect on plants under elevated CO(2). The effects of increased temperature on beneficial plant-associated microorganisms were more variable, positive and neutral, and negative effects were equally common and varied considerably with the study system and the temperature range investigated. Moreover, numerous studies indicated that plant growth-promoting microorganisms (both bacteria and fungi) positively affected plants subjected to drought stress. Overall, this review shows that plant-associated microorganisms are an important factor influencing the response of plants to climate change.

  4. Process for selecting polyhydroxyalkanoate (PHA) producing micro-organisms

    NARCIS (Netherlands)

    Van Loosdrecht, M.C.M.; Kleerebezem, R.; Jian, Y.; Johnson, K.

    2009-01-01

    The invention relates to a process for selecting a polyhydroxyalkanoate (PHA) producing micro-organism from a natural source comprising a variety of micro-organisms, comprising steps of preparing a fermentation broth comprising the natural source and nutrients in water; creating and maintaining

  5. Process for selecting polyhydroxyalkanoate (PHA) producing micro-organisms

    NARCIS (Netherlands)

    Van Loosdrecht, M.C.M.; Kleerebezem, R.; Jian, Y.; Johnson, K.

    2009-01-01

    The invention relates to a process for selecting a polyhydroxyalkanoate (PHA) producing micro-organism from a natural source comprising a variety of micro-organisms, comprising steps of preparing a fermentation broth comprising the natural source and nutrients in water; creating and maintaining aero

  6. Glyphosate-Degrading Microorganisms from Industrial Activated Sludge

    OpenAIRE

    Balthazor, Terry M.; Hallas, Laurence E.

    1986-01-01

    A plating medium was developed to isolate N-phosphonomethylglycine (glyphosate)-degrading microorganisms, with glyphosate as the sole phosphorus source. Two industrial biosystems treating glyphosate wastes contained elevated microbial counts on the medium. One purified isolate metabolized glyphosate to aminomethylphosphonic acid, mineralizing this accumulating intermediate during log growth. This microorganism has been identified as a Flavobacterium species.

  7. Microorganisms in Food--Their Significance and Methods of Enumeration.

    Science.gov (United States)

    Andrews, S.

    1980-01-01

    Described are laboratory methods for enumerating microorganisms in food. These methods are utilized to determine if foods are potentially hazardous to the consumer due to high concentrations of microorganisms. Discussed are indicator organisms, including coliforms, interococci, yeasts, and molds; food poisoning organisms (staphylococci and…

  8. (-)-Epigallocatechin-3-gallate inhibition of Epstein-Barr virus spontaneous lytic infection involves ERK1/2 and PI3-K/Akt signaling in EBV-positive cells.

    Science.gov (United States)

    Liu, Sufang; Li, Hongde; Chen, Lin; Yang, Lifang; Li, Lili; Tao, Yongguan; Li, Wei; Li, Zijian; Liu, Haidan; Tang, Min; Bode, Ann M; Dong, Zigang; Cao, Ya

    2013-03-01

    Epstein-Barr virus (EBV) reactivation into the lytic cycle plays certain roles in the development of EBV-associated diseases, including nasopharyngeal carcinoma and lymphoma. In this study, we investigated the effects of the tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) on EBV spontaneous lytic infection and the mechanism(s) involved in EBV-positive cells. We found that EGCG could effectively inhibit the constitutive lytic infection of EBV at the DNA, gene transcription and protein levels by decreasing the phosphorylation and activation of extracellular signal-regulated kinase 1/2 (ERK1/2) and Akt. By using cellular signaling pathway-specific inhibitors, we also explored the signaling mechanisms underlying the inhibitory effects of EGCG on EBV spontaneous lytic infection in cell models. Results show that specific inhibitors of Mitogen-Activated Protein Kinase Kinase (MEK) (PD98059) and phosphatidylinositol 3-kinase [PI3-K (LY294002)] markedly downregulated gene transcription and expression of BZLF1 and BMRF1 indicating that the MEK/ERK1/2 and PI3-K/Akt pathways are involved in the EBV spontaneous lytic cycle cascade. Therefore, one of the mechanisms by which EGCG inhibits EBV spontaneous lytic infection appears to involve the suppression of the activation of MEK/ERK1/2 and PI3-K/Akt signaling.

  9. Isolation and identification of enzyme-producing bacteria from the digestive tract of Epinehelus moara in re-circulating aquaculture sys-tems%工厂化循环水养殖条件下云纹石斑鱼消化道产酶菌的分离鉴定

    Institute of Scientific and Technical Information of China (English)

    施兆鸿; 王建建; 高权新

    2015-01-01

    The purpose of this research was to study the bacterial community structure in digestive tract and en-zyme production capacity of enzyme-producing bacteria, and provide reference for selection and application of probiotics for carnivorous fish culture. In this experiment, samples of juvenile saladfish (Epinehelus moara) stomach, pyloric caeca, foregut, midgut, and hindgut were obtained in recirculating aquaculture systems. Bacterial community structure was analyzed using 16S rDNA-PCR. The enzyme-producing bacteria were isolated and iden-tified by isolating and screening enzyme-producing bacteria. Moreover, the enzyme activities were tested. Twenty-seven strains were isolated and cultured under experimental conditions, including 13 strains of Pseudo-monas, 5 strains of Exiguobacterium, 7 strains of Acinetobacter, 1 strain of Stenotrophomonas, and 1 strain of Staphylococcus, which accounted for 48.2%, 18.5%, 25.9%, 3.7%, and 3.7%, respectively, of the isolated bacteria. The sequence homology of corresponding genes was greater than 98%. Fifteen strains produced enzymes and ac-counted for 55.6%of all bacteria;these bacteria included 7 strains of Pseudomonas, 5 strains of Exiguobacterium, 2 strains of Acinetobacter and 1 strain of Stenotrophomonas. Among these bacteria, 13 strains can produce both protease and amylase, whereas 4 strains can produce protease, amylase, and lipase. Among the enzyme-producing bacteria, 5 strains can produce 3 enzymes and 9 strains can produce 2 enzymes. Moreover, the bacteria in the midgut and hindgut were most abundant, and those in the stomach, diverticulum pyloricum and foregut were less abundant; the bacteria that produce lipase were concentrated in the midgut. Protease and amylase were the main enzymes produced by these bacteria; these two enzymes were highly productive, with protease activity up to (87.732±1.134) U/mL and amylase activity between (77.176±0.599) U/mL and (73.458±0.574) U/mL. Only one strain produced cellulase, and

  10. Application of lignocellulolytic enzymes produced under solid state cultivation conditions.

    Science.gov (United States)

    Deswal, Deepa; Sharma, Abha; Gupta, Rishi; Kuhad, Ramesh Chander

    2012-07-01

    In this paper, cellulose from brown-rot fungus Fomitopsis sp. RCK2010, thermostable and alkalostable xylanase from Bacillus pumilus MK001 and laccase from Ganoderma sp. rckk-02 were evaluated for (i) saccharification of alkali pretreated rice straw and wheat straw, (ii) upgradation of chick feed and (iii) decolorization of dyes, respectively. The cellulose from brown-rot fungus resulted in a sugar release of 151.48 and 214.11 mg/g, respectively, from rice straw and wheat straw, which was comparatively higher than the earlier reports. While xylan, one of the main anti-nutritional factors (ANFs) present in the chick feed was removed to an extent of 11.6 mg/g xylose sugars at 50°C using the thermostable xylanase. Besides, the treatment with thermostable xylanase also brought about a release of 0.85 (mg/g) of soluble phosphorous. Moreover, the laccase when used for the decolorization of Remazol Brilliant Blue R (RBBR) and xylidine ponceau cause almost complete decolorization in 2 and 4h, respectively, depicting high rate of decolorization.

  11. Extracellular proteolytic enzymes produced by human pathogenic Vibrio species

    Directory of Open Access Journals (Sweden)

    Shin-Ichi eMiyoshi

    2013-11-01

    Full Text Available Bacteria in the genus Vibrio produce extracellular proteolytic enzymes to obtain nutrients via digestion of various protein substrates. However, the enzymes secreted by human pathogenic species have been documented to modulate the bacterial virulence. Several species including Vibrio cholerae and V. vulnificus are known to produce thermolysin-like metalloproteases termed vibriolysin. The vibriolysin from V. vulnificus, a causative agent of serious systemic infection, is a major toxic factor eliciting the secondary skin damage characterized by formation of the hemorrhagic brae. The vibriolysin from intestinal pathogens may play indirect roles in pathogenicity because it can activate protein toxins and hemagglutinin by the limited proteolysis and can affect the bacterial attachment to or detachment from the intestinal surface by degradation of the mucus layer. Two species causing wound infections, V. alginolyticus and V. parahaemolyticus, produce another metalloproteases so-called collagenases. Although the detailed pathological roles have not been studied, the collagenase is potent to accelerate the bacterial dissemination through digestion of the protein components of the extracellular matrix. Some species produce cymotrypsin-like serine proteases, which may also affect the bacterial virulence potential. The intestinal pathogens produce sufficient amounts of the metalloprotease at the small intestinal temperature; however, the metalloprotease production by extra-intestinal pathogens is much higher around the body surface temperature. On the other hand, the serine protease is expressed only in the absence of the metalloprotease.

  12. 微生物源菊粉酶的研究进展%Research advance on inulinase produced by microorganism

    Institute of Scientific and Technical Information of China (English)

    宫颖; 于基成; 刘秋; 陈娇; 于春

    2014-01-01

    菊粉是由果糖分子经β-2,1糖苷键连接形成的多聚果糖,是一种存在于菊芋和菊苣等植物中的天然碳水化合物。作为新资源食品和食品原料,其研究已备受国内外关注。而以菊粉开发系列的功能性食品发展迅速。菊粉酶是一种能水解菊粉中β-2,1果糖苷键的一类水解酶,主要为真菌、酵母菌和细菌等微生物发酵产物,是以菊粉生产高纯度果糖浆、低聚果糖的关键酶。微生物源菊粉酶在食品、医药等领域中的重要应用价值和良好应用前景越来越成为研究者的研究热点。本文综述了近年来国内外微生物源菊粉酶的研究现状,主要论述了产酶微生物菌株的筛选、产酶条件、工程菌株的构建及应用等研究的进展。%Inulin exists as a reserved carbohydrate in the roots and tubers of plants such asjerusalem arti-choke, chicory and so on. It consists of linear chains ofβ-2,1-linked D-fructofuranose molecules terminated by a glucose residue. As a kind of new resource food or food material, the research on inulin has been paid more attentions. Inulinase is a key enzyme coming from fungi, yeast and bacteria. It targets theβ-2,1 linkage of in-ulin and hydrolyzes it into fructose and fructooligosaccharides. Inulinase deriving from microorganism has been taken more and more attentions by researchers because of its important value and good prospect of appli-cation in food and medicine fields. The development of inulinase produced by microorganisms is reviewed in recent years, including microorganism producing inulinase isolated, enzyme producing conditions, construction of engineering strain and its application.

  13. Cybernetic modeling of adaptive prediction of environmental changes by microorganisms.

    Science.gov (United States)

    Mandli, Aravinda R; Modak, Jayant M

    2014-02-01

    Microorganisms exhibit varied regulatory strategies such as direct regulation, symmetric anticipatory regulation, asymmetric anticipatory regulation, etc. Current mathematical modeling frameworks for the growth of microorganisms either do not incorporate regulation or assume that the microorganisms utilize the direct regulation strategy. In the present study, we extend the cybernetic modeling framework to account for asymmetric anticipatory regulation strategy. The extended model accurately captures various experimental observations. We use the developed model to explore the fitness advantage provided by the asymmetric anticipatory regulation strategy and observe that the optimal extent of asymmetric regulation depends on the selective pressure that the microorganisms experience. We also explore the importance of timing the response in anticipatory regulation and find that there is an optimal time, dependent on the extent of asymmetric regulation, at which microorganisms should respond anticipatorily to maximize their fitness. We then discuss the advantages offered by the cybernetic modeling framework over other modeling frameworks in modeling the asymmetric anticipatory regulation strategy.

  14. Effectiveness of ozone against periodontal pathogenic microorganisms.

    Science.gov (United States)

    Huth, Karin C; Quirling, Martina; Lenzke, Stefanie; Paschos, Ekaterini; Kamereck, Klaus; Brand, Korbinian; Hickel, Reinhard; Ilie, Nicoleta

    2011-06-01

    Ozone has been proposed as an adjunct antiseptic in periodontitis therapy. The aim of this study was to investigate the antimicrobial effectiveness of gaseous/aqueous ozone, in comparison with that of the established antiseptic chlorhexidine digluconate (CHX), against periodontal microorganisms. Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, and Parvimonas micra in planktonic or biofilm cultures were exposed, for 1 min, to gaseous ozone, aqueous ozone, CHX, or phosphate-buffered saline (control). None of the agents was able to substantially reduce the A. actinomycetemcomitans count in biofilm cultures. In contrast, P. gingivalis, T. forsythia, and P. micra could be eliminated by 2% CHX or by ozone gas at 53 gm(-3) . Significantly greater antimicrobial effects were observed against planktonic cultures than against biofilm-associated bacteria. The rate of killing was influenced by the species of bacteria, and by the type and concentration of agent. There were no significant differences in the effectiveness of aqueous ozone (20 μg ml(-1) ) or gaseous ozone (≥ 4 gm(-3) ) compared with 2% CHX but they were more effective than 0.2% CHX. Therefore, high-concentrated gaseous and aqueous ozone merit further investigation as antiseptics in periodontitis therapy. A safe system for applying gaseous ozone into the periodontal pocket that avoids inhalation still needs to be developed.

  15. Rapidly evolving microorganisms with high biofuel tolerance

    Science.gov (United States)

    Vyawahare, Saurabh; Zhang, Qiucen; Lang, Wendy; Austin, Robert

    2012-02-01

    Replacing non-renewable energy sources is one of the biggest and most exciting challenges of our generation. Algae and bacteria are poised to become major renewable biofuels if strains can be developed that provide a high,consistent and robust yield of oil. One major stumbling block towards this goal is the lack of tolerance to high concentrations of biofuels like isobutanol. Using traditional bioengineering techniques to remedy this face the hurdle of identifying the correct pathway or gene to modify. But the multiplicity of interactions inside a cell makes it very hard to determine what to modify a priori. Instead, we propose a technology that does not require prior knowledge of the genes or pathways to modify. In our approach that marries microfabrication and ecology, spatial heterogeneity is used as a knob to speed up evolution in the desired direction. Recently, we have successfully used this approach to demonstrate the rapid emergence of bacterial antibiotic resistance in as little as ten hours. Here, we describe our experimental results in developing new strains of micro-organisms with high oil tolerance. Besides biofuel production, our work is also relevant to oil spill clean-ups.

  16. Snow as a habitat for microorganisms

    Science.gov (United States)

    Hoham, Ronald W.

    1989-01-01

    There are three major habitats involving ice and snow, and the microorganisms studied from these habitats are most eukaryotic. Sea ice is inhabited by algae called diatoms, glacial ice has sparse populations of green algai cal desmids, and the temporary and permanent snows in mountainous regions and high latitudes are inhabited mostly by green algal flagellates. The life cycle of green algal flagellates is summarized by discussing the effects of light, temperature, nutrients, and snow melts. Specific examples of optimal conditions and environmental effects for various snow algae are given. It is not likely that the eukaryotic snow algae presented are candidated for life on the planet Mars. Evolutionally, eukaryotic cells as know on Earth may not have had the opportunity to develop on Mars (if life evolved at all on Mars) since eukaryotes did not appear on Earth until almost two billion years after the first prokaryotic organisms. However, the snow/ice ecosystems on Earth present themselves as extreme habitats were there is evidence of prokaryotic life (eubacteria and cyanbacteria) of which literally nothing is known. Any future surveillances of extant and/or extinct life on Mars should include probes (if not landing sites) to investigate sites of concentrations of ice water. The possibility of signs of life in Martian polar regions should not be overlooked.

  17. Autonomous support for microorganism research in space

    Science.gov (United States)

    Fleet, Mary L.; Miller, Mark S.; Shipley, Derek, E.; Smith, Jeff D.

    1992-01-01

    A preliminary design for performing on orbit, autonomous research on microorganisms and cultured cells/tissues is presented. An understanding of gravity and its effects on cells is crucial for space exploration as well as for terrestrial applications. The payload is designed to be compatible with the Commercial Experiment Transporter (COMET) launch vehicle, an orbiter middeck locker interface, and with Space Station Freedom. Uplink/downlink capabilities and sample return through controlled reentry are available for all carriers. Autonomous testing activities are preprogrammed with in-flight reprogrammability. Sensors for monitoring temperature, pH, light, gravity levels, vibrations, and radiation are provided for environmental regulation and experimental data collection. Additional experimental data acquisition includes optical density measurement, microscopy, video, and film photography. On-board full data storage capabilities are provided. A fluid transfer mechanism is utilized for inoculation, sampling, and nutrient replenishment of experiment cultures. In addition to payload design, representative experiments were developed to ensure scientific objectives remained compatible with hardware capabilities. The project is defined to provide biological data pertinent to extended duration crewed space flight including crew health issues and development of a Controlled Ecological Life Support System (CELSS). In addition, opportunities are opened for investigations leading to commercial applications of space, such as pharmaceutical development, modeling of terrestrial diseases, and material processing.

  18. Evaluation of actinide biosorption by microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Happel, A.M.

    1996-06-01

    Conventional methods for removing metals from aqueous solutions include chemical precipitation, chemical oxidation or reduction, ion exchange, reverse osmosis, electrochemical treatment and evaporation. The removal of radionuclides from aqueous waste streams has largely relied on ion exchange methods which can be prohibitively costly given increasingly stringent regulatory effluent limits. The use of microbial cells as biosorbants for heavy metals offers a potential alternative to existing methods for decontamination or recovery of heavy metals from a variety of industrial waste streams and contaminated ground waters. The toxicity and the extreme and variable conditions present in many radionuclide containing waste streams may preclude the use of living microorganisms and favor the use of non-living biomass for the removal of actinides from these waste streams. In the work presented here, we have examined the biosorption of uranium by non-living, non-metabolizing microbial biomass thus avoiding the problems associated with living systems. We are investigating biosorption with the long term goal of developing microbial technologies for the remediation of actinides.

  19. Heavy metal removal and recovery using microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Wilde, E.W. (Westinghouse Savannah River Co., Aiken, SC (United States)); Benemann, J.R. (Benemann (J.R.), Pinole, CA (United States))

    1991-02-01

    Microorganisms -- bacteria, fungi, and microalgae -- can accumulate relatively large amounts of toxic heavy metals and radionuclides from the environment. These organisms often exhibit specificity for particular metals. The metal content of microbial biomass can be a substantial fraction of total dry weight with concentration factors (metal in dry biomass to metal in solution) exceeding one million in some cases. Both living and inert (dead) microbial biomass can be used to reduce heavy metal concentrations in contaminated waters to very low levels -- parts per billion and even lower. In many respects (e.g. specificity, residual metal concentrations, accumulation factors, and economics) microbial bioremoval processes can be superior to conventional processes, such as ion exchange and caustic (lime or hydroxide) precipitation for heavy metals removal from waste and contaminated waters. Thus, bioremoval could be developed to contribute to the clean-up of wastes at the Savannah River Site (SRS) and other DOE facilities. However, the potential advantages of bioremoval processes must still be developed into practical operating systems. A detailed review of the literature suggests that appropriate bioremoval processes could be developed for the SRS. There is great variability from one biomass source to another in bioremoval capabilities. Bioremoval is affected by pH, other ions, temperature, and many other factors. The biological (living vs. dead) and physical (immobilized vs. dispersed) characteristics of the biomass also greatly affect metal binding. Even subtle differences in the microbial biomass, such as the conditions under which it was cultivated, can have major effects on heavy metal binding.

  20. Isolation of porphyran-degrading marine microorganisms from the surface of red alga, Porphyra yezoensis.

    Science.gov (United States)

    Yoshimura, Takashi; Tsuge, Keisuke; Sumi, Toshihisa; Yoshiki, Masahiro; Tsuruta, Yumi; Abe, Shin-ichi; Nishino, Shiduo; Sanematsu, Seigo; Koganemaru, Kazuyoshi

    2006-04-01

    Marine microorganisms degrading porphyran (POR) were found on the surface of thalli of Porphyra yezoensis. Fifteen crude microorganism groups softened and liquefied the surface of agar-rich plate medium. Among these, 11 microorganism groups degraded porphyran that consisted of sulfated polysaccharide in Porphyra yezoensis. Following isolation, 7 POR-degradable microorganisms were isolated from the 11 POR-degradable microorganism groups.

  1. Single cell genomics of subsurface microorganisms

    Science.gov (United States)

    Stepanauskas, R.; Onstott, T. C.; Lau, C.; Kieft, T. L.; Woyke, T.; Rinke, C.; Sczyrba, A.; van Heerden, E.

    2012-12-01

    Recent studies have revealed unexpected abundance and diversity of microorganisms in terrestrial and marine subsurface, providing new perspectives over their biogeochemical significance, evolution, and the limits of life. The now commonly used research tools, such as metagenomics and PCR-based gene surveys enabled cultivation-unbiased analysis of genes encoded by natural microbial communities. However, these methods seldom provide direct evidence for how the discovered genes are organized inside genomes and from which organisms do they come from. Here we evaluated the feasibility of an alternative, single cell genomics approach, in the analysis of subsurface microbial community composition, metabolic potential and microevolution at the Sanford Underground Research Facility (SURF), South Dakota, and the Witwaterstrand Basin, South Africa. We successfully recovered genomic DNA from individual microbial cells from multiple locations, including ultra-deep (down to 3,500 m) and low-biomass (down to 10^3 cells mL^-1) fracture water. The obtained single amplified genomes (SAGs) from SURF contained multiple representatives of the candidate divisions OP3, OP11, OD1 and uncharacterized archaea. By sequencing eight of these SAGs, we obtained the first genome content information for these phylum-level lineages that do not contain a single cultured representative. The Witwaterstrand samples were collected from deep fractures, biogeochemical dating of which suggests isolation from tens of thousands to tens of millions of years. Thus, these fractures may be viewed as "underground Galapagos", a natural, long-term experiment of microbial evolution within well-defined temporal and spatial boundaries. We are analyzing multiple SAGs from these environments, which will provide detailed information about adaptations to life in deep subsurface, mutation rates, selective pressures and gene flux within and across microbial populations.

  2. [Metagenomics as a Tool for the Investigation of Uncultured Microorganisms].

    Science.gov (United States)

    Ravin, N V; Mardanova, A V; Skryabin, K G

    2015-05-01

    Uncultured microorganisms represent a significant part of the Earth's biodiversity. Natural ecosystems contain less than 0.1-1% of the microorganisms that can be cultured in the laboratory. Therefore, new methodological approaches are required for the identification and description of uncultured microorganisms, for studies of their genetic diversity and the structure of microbial associations, and for an understanding of their ecological importance in the biosphere. Metagenomics, a method of analyzing the collective genome.of a microbial community without cultivation, makes it possible to unravel fundamental matters of the microbiology and ecology of microorganisms. Another efficient method of analysis of uncultured forms of microorganisms is "single cell genomics," which involves the isolation of single cells from microbial communities and the sequencing of their genomes. Developed in the last decade, the high throughput technologies of next-generation sequencing provide important input into the investigation of genome reconstruction for all of the microorganisms residing and interacting within ecosystems. This review describes the major methodological approaches used in metagenomic analysis of microbial communities, as well as accomplishments in the search for new uncultured microorganism, the unraveling of their genomes, and an elucidation of their role in ecosystems.

  3. Isolation and characterization of Arctic microorganisms decomposing bioplastics.

    Science.gov (United States)

    Urbanek, Aneta K; Rymowicz, Waldemar; Strzelecki, Mateusz C; Kociuba, Waldemar; Franczak, Łukasz; Mirończuk, Aleksandra M

    2017-12-01

    The increasing amount of plastic waste causes significant environmental pollution. In this study, screening of Arctic microorganisms which are able to degrade bioplastics was performed. In total, 313 microorganisms were isolated from 52 soil samples from the Arctic region (Spitsbergen). Among the isolated microorganisms, 121 (38.66%) showed biodegradation activity. The ability of clear zone formation on emulsified poly(butylene succinate-co-adipate) (PBSA) was observed for 116 microorganisms (95.87%), on poly(butylene succinate) (PBS) for 73 microorganisms (60.33%), and on poly(ɛ-caprolactone) (PCL) for 102 microorganisms (84.3%). Moreover, the growth of microorganisms on poly(lactic acid) (PLA) agar plates was observed for 56 microorganisms (46.28%). Based on the 16S rRNA sequence, 10 bacterial strains which showed the highest ability for biodegradation were identified as species belonging to Pseudomonas sp. and Rhodococcus sp. The isolated fungal strains were tested for polycaprolactone films and commercial corn and potato starch bags degradation under laboratory conditions. Strains 16G (based on the analysis of a partial 18S rRNA sequence, identified as Clonostachys rosea) and 16H (identified as Trichoderma sp.) showed the highest capability for biodegradation. A particularly high capability for biodegradation was observed for the strain Clonostachys rosea, which showed 100% degradation of starch films and 52.91% degradation of PCL films in a 30-day shake flask experiment. The main advantage of the microorganisms isolated from Arctic environment is the ability to grow at low temperature and efficient biodegradation under this condition. The data suggest that C. rosea can be used in natural and laboratory conditions for degradations of bioplastics.

  4. Participation of microorganisms in processes of waste biodegradation

    Directory of Open Access Journals (Sweden)

    V. V. Kolomoets

    2009-11-01

    Full Text Available It is shown, that microorganisms can be used for utilisation of products of waste degradation. The influence of microelements small doses on the ability of secured cultures of soil microorganisms to grow on poor nutrient medium was studied. The cultures simulate the relationship of the end products of waste pyrolysis. The positive influence of MnCl2, K2HPO4, NH4NО3 as well as the complex of microelements on the ability of secured microorganisms to accumulate the biomass and assimilate the substrate is shown. Among two secured and studied germ culturesthe genus of –Bacillus is more promising.

  5. Functional Elucidation of Nemopilema nomurai and Cyanea nozakii Nematocyst Venoms’ Lytic Activity Using Mass Spectrometry and Zymography

    Directory of Open Access Journals (Sweden)

    Yang Yue

    2017-01-01

    Full Text Available Background: Medusozoans utilize explosively discharging penetrant nematocysts to inject venom into prey. These venoms are composed of highly complex proteins and peptides with extensive bioactivities, as observed in vitro. Diverse enzymatic toxins have been putatively identified in the venom of jellyfish, Nemopilema nomurai and Cyanea nozakii, through examination of their proteomes and transcriptomes. However, functional examination of putative enzymatic components identified in proteomic approaches to elucidate potential bioactivities is critically needed. Methods: In this study, enzymatic toxins were functionally identified using a combined approach consisting of in gel zymography and liquid chromatography tandem mass spectrometry (LC-MS/MS. The potential roles of metalloproteinases and lipases in hemolytic activity were explored using specific inhibitors. Results: Zymography indicated that nematocyst venom possessed protease-, lipase- and hyaluronidase-class activities. Further, proteomic approaches using LC-MS/MS indicated sequence homology of proteolytic bands observed in zymography to extant zinc metalloproteinase-disintegrins and astacin metalloproteinases. Moreover, pre-incubation of the metalloproteinase inhibitor batimastat with N. nomurai nematocyst venom resulted in an approximate 62% reduction of hemolysis compared to venom exposed sheep erythrocytes, suggesting that metalloproteinases contribute to hemolytic activity. Additionally, species within the molecular mass range of 14–18 kDa exhibited both egg yolk and erythrocyte lytic activities in gel overlay assays. Conclusion: For the first time, our findings demonstrate the contribution of jellyfish venom metalloproteinase and suggest the involvement of lipase species to hemolytic activity. Investigations of this relationship will facilitate a better understanding of the constituents and toxicity of jellyfish venom.

  6. Herpesviral ICP0 Protein Promotes Two Waves of Heterochromatin Removal on an Early Viral Promoter during Lytic Infection

    Directory of Open Access Journals (Sweden)

    Jennifer S. Lee

    2016-01-01

    Full Text Available Herpesviruses must contend with host cell epigenetic silencing responses acting on their genomes upon entry into the host cell nucleus. In this study, we confirmed that unchromatinized herpes simplex virus 1 (HSV-1 genomes enter primary human foreskin fibroblasts and are rapidly subjected to assembly of nucleosomes and association with repressive heterochromatin modifications such as histone 3 (H3 lysine 9-trimethylation (H3K9me3 and lysine 27-trimethylation (H3K27me3 during the first 1 to 2 h postinfection. Kinetic analysis of the modulation of nucleosomes and heterochromatin modifications over the course of lytic infection demonstrates a progressive removal that coincided with initiation of viral gene expression. We obtained evidence for three phases of heterochromatin removal from an early gene promoter: an initial removal of histones and heterochromatin not dependent on ICP0, a second ICP0-dependent round of removal of H3K9me3 that is independent of viral DNA synthesis, and a third phase of H3K27me3 removal that is dependent on ICP0 and viral DNA synthesis. The presence of ICP0 in transfected cells is also sufficient to promote removal of histones and H3K9me3 modifications of cotransfected genes. Overall, these results show that ICP0 promotes histone removal, a reduction of H3K9me3 modifications, and a later indirect reduction of H3K27me3 modifications following viral early gene expression and DNA synthesis. Therefore, HSV ICP0 promotes the reversal of host epigenetic silencing mechanisms by several mechanisms.

  7. An antisense RNA in a lytic cyanophage links psbA to a gene encoding a homing endonuclease.

    Science.gov (United States)

    Millard, Andrew D; Gierga, Gregor; Clokie, Martha R J; Evans, David J; Hess, Wolfgang R; Scanlan, David J

    2010-09-01

    Cyanophage genomes frequently possess the psbA gene, encoding the D1 polypeptide of photosystem II. This protein is believed to maintain host photosynthetic capacity during infection and enhance phage fitness under high-light conditions. Although the first documented cyanophage-encoded psbA gene contained a group I intron, this feature has not been widely reported since, despite a plethora of new sequences becoming available. In this study, we show that in cyanophage S-PM2, this intron is spliced during the entire infection cycle. Furthermore, we report the widespread occurrence of psbA introns in marine metagenomic libraries, and with psbA often adjacent to a homing endonuclease (HE). Bioinformatic analysis of the intergenic region between psbA and the adjacent HE gene F-CphI in S-PM2 showed the presence of an antisense RNA (asRNA) connecting these two separate genetic elements. The asRNA is co-regulated with psbA and F-CphI, suggesting its involvement with their expression. Analysis of scaffolds from global ocean survey datasets shows this asRNA to be commonly associated with the 3' end of cyanophage psbA genes, implying that this potential mechanism of regulating marine 'viral' photosynthesis is evolutionarily conserved. Although antisense transcription is commonly found in eukaryotic and increasingly also in prokaryotic organisms, there has been no indication for asRNAs in lytic phages so far. We propose that this asRNA also provides a means of preventing the formation of mobile group I introns within cyanophage psbA genes.

  8. Reduction of Salmonella on chicken meat and chicken skin by combined or sequential application of lytic bacteriophage with chemical antimicrobials.

    Science.gov (United States)

    Sukumaran, Anuraj T; Nannapaneni, Rama; Kiess, Aaron; Sharma, Chander Shekhar

    2015-08-17

    The effectiveness of recently approved Salmonella lytic bacteriophage preparation (SalmoFresh™) in reducing Salmonella in vitro and on chicken breast fillets was examined in combination with lauric arginate (LAE) or cetylpyridinium chloride (CPC). In another experiment, a sequential spray application of this bacteriophage (phage) solution on Salmonella inoculated chicken skin after a 20s dip in chemical antimicrobials (LAE, CPC, peracetic acid, or chlorine) was also examined in reducing Salmonella counts on chicken skin. The application of phage in combination with CPC or LAE reduced S. Typhimurium, S. Heidelberg, and S. Enteritidis up to 5 log units in vitro at 4 °C. On chicken breast fillets, phage in combination with CPC or LAE resulted in significant (pSalmonella ranging from 0.5 to 1.3 log CFU/g as compared to control up to 7 days of refrigerated storage. When phage was applied sequentially with chemical antimicrobials, all the treatments resulted in significant reductions of Salmonella. The application of chlorine (30 ppm) and PAA (400 ppm) followed by phage spray (10(9)PFU/ml) resulted in highest Salmonella reductions of 1.6-1.7 and 2.2-2.5l og CFU/cm(2), respectively. In conclusion, the surface applications of phage in combination with LAE or CPC significantly reduced Salmonella counts on chicken breast fillets. However, higher reductions in Salmonella counts were achieved on chicken skin by the sequential application of chemical antimicrobials followed by phage spray. The sequential application of chlorine, PAA, and phage can provide additional hurdles to reduce Salmonella on fresh poultry carcasses or cut up parts.

  9. Hemorrhagic, coagulant and fibrino(geno)lytic activities of crude venom and fractions from mapanare (Bothrops colombiensis) snakes.

    Science.gov (United States)

    Girón, María E; Salazar, Ana M; Aguilar, Irma; Pérez, John C; Sánchez, Elda E; Arocha-Piñango, Carmen L; Rodríguez-Acosta, Alexis; Guerrero, Belsy

    2008-01-01

    Bothrops colombiensis venom from two similar geographical locations were tested for their hemostatic functions and characterized by gel-filtration chromatography and SDS-PAGE electrophoresis. The snakes were from Caucagua and El Guapo towns of the Venezuelan state of Miranda. Fibrino(geno)lytic, procoagulant, hemorrhagic, lethal activities, gel-filtration chromatography and SDS-PAGE profiles were analyzed and compared for both venoms. The highest hemorrhagic activity of 5.3 mug was seen in El Guapo venom while Caucagua venom had the lowest LD(50) of 5.8 mg/kg. Both venoms presented similar thrombin-like activity. El Guapo showed a factor Xa-like activity two times higher than Caucagua. Differences were observed in kallikrein-like and t-PA activities, being highest in El Guapo. Caucagua venom showed the maximum fibrin lysis. Both crude venom runs on Sephadex G-100 chromatography gave fraction SII with the high fibrinolytic activity. Proteases presented in SII fractions and eluted from Benzamidine-Sepharose (not bound to the column) provoked a fast degradation of fibrinogen alpha chains and a slower degradation of beta chains, which could possibly be due to a higher content of alpha fibrinogenases in these venoms. The fibrinogenolytic activity was decreased by metalloprotease inhibitors. The results suggested that metalloproteases in SII fractions were responsible for the fibrinolytic activity. The analysis of samples for fibrin-zymography of SII fractions showed an active band with a molecular mass of approximately 30 kDa. These results reiterate the importance of using pools of venoms for antivenom immunization, to facilitate the neutralization of the maximum potential number of toxins.

  10. 77 FR 45350 - Notice of Availability of Microbial Risk Assessment Guideline: Pathogenic Microorganisms With...

    Science.gov (United States)

    2012-07-31

    ... Assessment Guideline: Pathogenic Microorganisms with Focus on Food and Water (MRA Guideline). The MRA... document, Microbial Risk Assessment Guideline: Pathogenic Microorganisms with Focus on Food and Water will... AGENCY Notice of Availability of Microbial Risk Assessment Guideline: Pathogenic Microorganisms...

  11. Indigenous microorganisms production and the effect on composting process

    Science.gov (United States)

    Abu-Bakar, Nurul-Ain; Ibrahim, Nazlina

    2013-11-01

    In this study, production of indigenous microorganisms (IMO) and effect on addition of IMO in composting process were done. Production of IMO was done in a series of steps to allow propagation of beneficial microorganisms. Effect of IMO addition in composting process was investigated by having 4 treatments; 1) rice straw without IMO nor manure and rice bran, 2) rice straw with IMO only, 3) rice straw with manure and rice bran, 4) rice straw with IMO, manure and rice bran. Production of IMO using cooked rice yields white molds. Addition of IMO during composting did not affect temperature increment. However, there were differences in numbers of microorganisms found during each stages of composting. Initial composting stage was dominated by mesophilic bacteria and actinomycetes, followed by thermophilic bacteria and later by actinomycetes upon composting completion. In conclusion, this study showed that IMO addition in composting increased microorganisms which are responsible in organic decomposition.

  12. Mineral Salt Medium (MSM) for extreme acidophilic microorganisms

    OpenAIRE

    sprotocols

    2015-01-01

    Medium for growth of extreme acidophilic microorganisms. This medium does not contain trace elements. When not working on mineral, addition of trace element (TE) solution is necessary, see separate protocol. http://www.nature.com/protocolexchange/protocols/3811

  13. Latest improvements in CIEF: from proteins to microorganisms.

    Science.gov (United States)

    Šalplachta, Jiří; Kubesová, Anna; Horká, Marie

    2012-10-01

    In recent years, characterization and identification of microorganisms has become very important in different fields of human activity. Conventional laboratory methods are time consuming, laborious, and they may provide both false positive or negative results, especially for closely related microorganisms. On that account, new methods for fast and reliable microbial characterization are of great interest. In particular, capillary electrophoretic techniques have a great potential for characterization of microorganisms due to their unique surface properties. Cell surface proteins play a key role in this respect. Since CIEF represents one of the most efficient techniques for protein separation, it was consequently applied to the analysis of microbial cells. This review describes, after a brief introduction to CIEF of proteins, recent developments in CIEF of diverse microorganisms (viruses, bacteria, yeasts, and fungi). Possible application schemes in human and veterinary medicine as well as in plant protection and in biosecurity are outlined.

  14. Technologies for Beneficial Microorganisms Inocula Used as Biofertilizers

    Directory of Open Access Journals (Sweden)

    E. Malusá

    2012-01-01

    Full Text Available The increasing need for environmentaly friendly agricultural practices is driving the use of fertilizers based on beneficial microorganisms. The latter belong to a wide array of genera, classes, and phyla, ranging from bacteria to yeasts and fungi, which can support plant nutrition with different mechanisms. Moreover, studies on the interactions between plant, soil, and the different microorganisms are shedding light on their interrelationships thus providing new possible ways to exploit them for agricultural purposes. However, even though the inoculation of plants with these microorganisms is a well-known practice, the formulation of inocula with a reliable and consistent effect under field conditions is still a bottleneck for their wider use. The choice of the technology for inocula production and of the carrier for the formulation is key to their successful application. This paper focuses on how inoculation issues can be approached to improve the performance of beneficial microorganisms used as a tool for enhancing plant growth and yield.

  15. Effects of tourmaline on growth of three kinds of microorganisms

    African Journals Online (AJOL)

    AJL

    2012-05-22

    May 22, 2012 ... Key words: Microcalorimetric, water cluster, growth rate, inhibitory ratio. ... study the effect of tourmaline on some microorganism (Ni et al., 2008), there are ..... the activities of compounds on metabolism of Escherichia coli: A.

  16. A device for continuous microscopic examination of aquatic microorganisms

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, S.

    The device consists of a sealed microscopic mount provided with an inlet for liquid medium and an outlet, permitting continuous flow of the liquid. It permits observation of development of marine microorganisms such as thraustochytrids for 3 d...

  17. [Bio-active substances derived from marine microorganisms].

    Science.gov (United States)

    Liu, Quanyong; Hu, Jiangchun; Xue, Delin; Ma, Chengxin; Wang, Shujin

    2002-07-01

    Marine microorganisms, which are taxonomically diverse and genetically special, have powerful potential in producing novel bio-active substances. This article summarized research progress in this respect. The results showed that marine bacteria which are main marine microorganism flora can produce rich kinds of bio-active substances and that even though marine actinomycetes and marine fungi are not as many as marine bacteria in species and quantity, they should be paid no less attention about their bio-active substances. Besides, present research are limited to those marine microorganisms which are easily cultured. One of the future research trends will be focused on bio-active substances derived from non-culturable marine microorganisms.

  18. isolation and identification of the microorganisms most prevalent in ...

    African Journals Online (AJOL)

    blood and MacConkey plates for culture. ... microorganisms most prevalent in external eye infections in Owerri urban (as seen Mercy Eye clinic). ... surfaces, as the case may be, from infected eyes and streaked immediately on blood and ...

  19. Technologies for Beneficial Microorganisms Inocula Used as Biofertilizers

    Science.gov (United States)

    Malusá, E.; Sas-Paszt, L.; Ciesielska, J.

    2012-01-01

    The increasing need for environmentaly friendly agricultural practices is driving the use of fertilizers based on beneficial microorganisms. The latter belong to a wide array of genera, classes, and phyla, ranging from bacteria to yeasts and fungi, which can support plant nutrition with different mechanisms. Moreover, studies on the interactions between plant, soil, and the different microorganisms are shedding light on their interrelationships thus providing new possible ways to exploit them for agricultural purposes. However, even though the inoculation of plants with these microorganisms is a well-known practice, the formulation of inocula with a reliable and consistent effect under field conditions is still a bottleneck for their wider use. The choice of the technology for inocula production and of the carrier for the formulation is key to their successful application. This paper focuses on how inoculation issues can be approached to improve the performance of beneficial microorganisms used as a tool for enhancing plant growth and yield. PMID:22547984

  20. the economic importance of microorganism in food processing

    African Journals Online (AJOL)

    BSN

    This paper attempts to highlight the Economic Importance of microorganisms in food processing and manufacturing; it goes further to differentiate between the desirable and the undesirable .... Lactobacil/us casei. Cheese. Lactobacil/.us lactic.

  1. Microorganisms having enhanced resistance to acetate and methods of use

    Science.gov (United States)

    Brown, Steven D; Yang, Shihui

    2014-10-21

    The present invention provides isolated or genetically modified strains of microorganisms that display enhanced resistance to acetate as a result of increased expression of a sodium proton antiporter. The present invention also provides methods for producing such microbial strains, as well as related promoter sequences and expression vectors. Further, the present invention provides methods of producing alcohol from biomass materials by using microorganisms with enhanced resistance to acetate.

  2. Microorganisms having enhanced tolerance to inhibitors and stress

    Science.gov (United States)

    Brown, Steven D.; Yang, Shihui

    2014-07-29

    The present invention provides genetically modified strains of microorganisms that display enhanced tolerance to stress and/or inhibitors such as sodium acetate and vanillin. The enhanced tolerance can be achieved by increasing the expression of a protein of the Sm-like superfamily such as a bacterial Hfq protein and a fungal Sm or Lsm protein. Further, the present invention provides methods of producing alcohol from biomass materials by using the genetically modified microorganisms of the present invention.

  3. Diversity and adaptations of deep-sea microorganisms

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, C.

    from moderately barophilic or barotolerant microorganisms. The effect of pressure on cell membrane, protein and gene expression are studied in detail in some of these microorganisms. Cold temperatures and high pressures decrease membrane fluidity... and affect a number of membrane-associated processes including ion and nutrient flux and DNA replication (Bartlett, 1992). A barotolerant strain of Alteromonas isolated from 4033 m in the Izu-Ogasawara Trench, Japan showed an increase in the proportion...

  4. Characterization of Airborne Microorganisms at Nationaltheatret Subway Station

    OpenAIRE

    Valen, Anja

    2011-01-01

    Bioaerosols containing pathogenic microorganisms can have health implications when respired. Of special concern are potential bioterrorism attacks conducted by deliberate aerosolization of hazardous toxins or pathogenic microorganisms. Investigation aiming at understanding the normal state of the bioaerosol environment is essential to facilitate detection of biological threat agents and deviations from the normal background. This MSc thesis presents a pilot study for investigation of the bioa...

  5. Rotary Apparatus Concentrates And Separates Micro-Organisms

    Science.gov (United States)

    Noever, David A.

    1992-01-01

    Apparatus concentrates and separates swimming micro-organisms of different species into concentric rings in fluid. Fluid containing high concentration of desired species removed by use of small scoop placed into fluid at radius of one of rings formed by that species. Micro-organisms concentrated into concentric rings by combined dynamic effects of upward and horizontal components of swimming, rotation of dish, gravitation, and viscosity.

  6. Method for treating wastewater using microorganisms and vascular aquatic plants

    Science.gov (United States)

    Wolverton, B. C. (Inventor)

    1983-01-01

    A method for treating wastewater compresses subjecting the wastewater to an anaerobic setting step for at least 6 hours and passing the liquid effluent from the anaerobic settling step through a filter cell in an upflow manner. There the effluent is subjected first to the action of anaerobic and facultative microorganisms, and then to the action of aerobic microorganisms and the roots of at least one vascular aquatic plant.

  7. Microorganisms having enhanced tolerance to inhibitors and stress

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Steven D.; Yang, Shihui

    2014-07-29

    The present invention provides genetically modified strains of microorganisms that display enhanced tolerance to stress and/or inhibitors such as sodium acetate and vanillin. The enhanced tolerance can be achieved by increasing the expression of a protein of the Sm-like superfamily such as a bacterial Hfq protein and a fungal Sm or Lsm protein. Further, the present invention provides methods of producing alcohol from biomass materials by using the genetically modified microorganisms of the present invention.

  8. Measuring airborne microorganisms and dust from livestock houses

    OpenAIRE

    Yang Zhao, Yang

    2011-01-01

      Airborne transmission has been suspected to be responsible for epidemics of highly infectious disease in livestock production. In such transmission, the pathogenic microorganisms may associate with dust particles. However, the extent to which airborne transmission plays a role in the spread of diseases between farms, and the relationship between microorganisms and dust remain unclear. In order to better understand airborne transmission and to set up effective control techniques, this s...

  9. Marine Microorganisms: perspectives for getting involved in cellulosic ethanol.

    Science.gov (United States)

    Intriago, Pablo

    2012-08-29

    The production of ethanol has been considered as an alternative to replace part of the petroleum derivate. Brazil and the US are the leading producers, but more environmentally friendly alternatives are needed. Lignocellulose has an enormous potential but technology has to be still improve in order to economically produce ethanol. The present paper reviews the potential and problems of this technology and proposes the study of a group of microorganisms with the largest genetic pool, marine microorganism.

  10. Pathogenic Microorganisms from Raw Milk of Different Animals

    OpenAIRE

    Letiţia Oprean; Ramona Iancu; Eniko Gaşpar; Ecaterina Lengyel

    2011-01-01

    Milk is an ideal environment for microbial growth and for this reason the separation of some pathogens is very important. The analysis of milk regarding pathogenic microorganisms is a clear indicator of hygienic quality and this influences the dairy production. Samples of raw milk from cow, goat and sheep were analyzed for pathogens like Staphylococcus aureus and Escherichia coli. The microorganisms found in milk directly affect the human health and can cause a public illness if the unpasteur...

  11. Interactions between novel micro-organisms and intestinal flora.

    Science.gov (United States)

    Aureli, P; Franciosa, G

    2002-09-01

    Microbial strains traditionally used to ferment food have a long history of safe use and are, therefore, considered as generally recognised as safe. Many of these micro-organisms have also functional attributes and are included among probiotics. New species and strains of bacteria with desirable technological and functional properties are constantly being identified; in addition, micro-organisms can be engineered by recently developed biotechnological tools in order to accelerate strain improvement. Although the potentialities of novel micro-organisms with better probiotic and technological properties are promising, it cannot be assumed that they share the safety record of traditional micro-organisms, since they may pose unique challenges for human health. The risk assessment and safety evaluation of novel micro-organisms must focus, primarily, on their potential harmful effects, both direct and indirect, upon host resident intestinal microflora. Genetically modified micro-organisms need further assessment for the complete characterisation of the DNA rearrangement and of the final product, in order to establish the "substantial equivalence" with the parental strain.

  12. New therapeutic approaches by using microorganism-derived compounds.

    Science.gov (United States)

    Amedei, A; D'Elios, M M

    2012-01-01

    The role of natural products as a source for remedies has been recognized since ancient times. Despite major scientific and technological progress in combinatorial chemistry, drugs derived from natural product still make an enormous contribution to drug discovery today. Nature is an attractive source of new therapeutic candidate compounds since a tremendous chemical diversity is found in millions of species of plants, animals, marine organisms and microorganisms. Microorganisms such as bacteria and fungi have been invaluable to discover drugs and lead compounds. These microorganisms produce a large variety of antimicrobial agents which have evolved to give their hosts an advantage over their competitors in the microbiological world. The screening of microorganisms became highly popular after the discovery of penicillin but in recent years the list of antibacterial agents (bacteria- or fungi-derived) has increased considerably with the arrival of cephalosporins, tetracyclines, aminoglycosides, rifamycins, and chloramphenicol. Although most of the drugs derived from microorganisms are used in antibacterial therapy, some microbial metabolites have provided lead compounds in other fields of medicine. For example: the fungal metabolite lovastatin, which was the lead compound for a series of drugs that lower cholesterol levels, the ciclosporin (fungal metabolite) currently used to suppress the immune response after transplantation operations and sirolimus- a bacterium-derived macrolide- used in the treatment of some cancers. The aim of this review is to analyze the current uses and the future applications in therapeutic treatments of microorganism-derived products (MdPs) and discuss the results obtained in the some clinical trials.

  13. An Epstein-Barr Virus-Encoded Protein Complex Requires an Origin of Lytic Replication In Cis to Mediate Late Gene Transcription.

    Directory of Open Access Journals (Sweden)

    Reza Djavadian

    2016-06-01

    Full Text Available Epstein-Barr virus lytic replication is accomplished by an intricate cascade of gene expression that integrates viral DNA replication and structural protein synthesis. Most genes encoding structural proteins exhibit "true" late kinetics-their expression is strictly dependent on lytic DNA replication. Recently, the EBV BcRF1 gene was reported to encode a TATA box binding protein homolog, which preferentially recognizes the TATT sequence found in true late gene promoters. BcRF1 is one of seven EBV genes with homologs found in other β- and γ-, but not in α-herpesviruses. Using EBV BACmids, we systematically disrupted each of these "βγ" genes. We found that six of them, including BcRF1, exhibited an identical phenotype: intact viral DNA replication with loss of late gene expression. The proteins encoded by these six genes have been found by other investigators to form a viral protein complex that is essential for activation of TATT-containing reporters in EBV-negative 293 cells. Unexpectedly, in EBV infected 293 cells, we found that TATT reporter activation was weak and non-specific unless an EBV origin of lytic replication (OriLyt was present in cis. Using two different replication-defective EBV genomes, we demonstrated that OriLyt-mediated DNA replication is required in cis for TATT reporter activation and for late gene expression from the EBV genome. We further demonstrate by fluorescence in situ hybridization that the late BcLF1 mRNA localizes to EBV DNA replication factories. These findings support a model in which EBV true late genes are only transcribed from newly replicated viral genomes.

  14. The Molecular Switch of Telomere Phages: High Binding Specificity of the PY54 Cro Lytic Repressor to a Single Operator Site

    Directory of Open Access Journals (Sweden)

    Jens Andre Hammerl

    2015-06-01

    Full Text Available Temperate bacteriophages possess a molecular switch, which regulates the lytic and lysogenic growth. The genomes of the temperate telomere phages N15, PY54 and ɸKO2 harbor a primary immunity region (immB comprising genes for the prophage repressor, the lytic repressor and a putative antiterminator. The roles of these products are thought to be similar to those of the lambda proteins CI, Cro and Q, respectively. Moreover, the gene order and the location of several operator sites in the prototype telomere phage N15 and in ɸKO2 are also reminiscent of lambda-like phages. By contrast, in silico analyses revealed the presence of only one operator (O\\(_{\\rm{R}}\\3 in PY54. The purified PY54 Cro protein was used for EMSA studies demonstrating that it exclusively binds to a 16-bp palindromic site (O\\(_{\\rm{R}}\\3 upstream of the prophage repressor gene. The O\\(_{\\rm{R}}\\3 operator sequences of PY54 and ɸKO2/N15 only differ by their peripheral base pairs, which are responsible for Cro specificity. PY54 cI and cro transcription is regulated by highly active promoters initiating the synthesis of a homogenious species of leaderless mRNA. The location of the PY54 Cro binding site and of the identified promoters suggests that the lytic repressor suppresses cI transcription but not its own synthesis. The results indicate an unexpected diversity of the growth regulation mechanisms in lambda-related phages.

  15. Salivary production of IgA and IgG to human herpes virus 8 latent and lytic antigens by patients in whom Kaposi's sarcoma has regressed.

    Science.gov (United States)

    Mbopi-Keou, Francois-Xavier; Legoff, Jerome; Piketty, Christophe; Hocini, Hakim; Malkin, Jean-Elie; Inoue, Naoki; Scully, Crispian M; Porter, Stephen R; Teo, Chong-Gee; Belec, Laurent

    2004-01-23

    IgG and IgA antibodies with specificities to a latent and a lytic antigen of human herpes virus 8 (HHV-8) were detectable in the saliva and serum of eight patients whose Kaposi's sarcoma had regressed, seven of whom were HIV-1 infected. The measurement of antibody-specific activity and secretion rate, and the detection of secretory IgA all indicate anti-HHV-8 antibody activity in saliva. The specific humoral responses possibly influence mucosal replication of HHV-8, and in turn, that of HIV.

  16. A Lytic Polysaccharide Monooxygenase with Broad Xyloglucan Specificity from the Brown-Rot Fungus Gloeophyllum trabeum and Its Action on Cellulose-Xyloglucan Complexes

    OpenAIRE

    KOJIMA, Yuka; Várnai, Anikó; Ishida, Takuya; Sunagawa, Naoki; Petrovic, Dejan M.; Igarashi, Kiyohiko; Jellison, Jody; GOODELL, BARRY; Alfredsen, Gry; Westereng, Bjørge; Vincent G H Eijsink; Yoshida, Makoto

    2016-01-01

    ABSTRACT Fungi secrete a set of glycoside hydrolases and lytic polysaccharide monooxygenases (LPMOs) to degrade plant polysaccharides. Brown-rot fungi, such as Gloeophyllum trabeum, tend to have few LPMOs, and information on these enzymes is scarce. The genome of G. trabeum encodes four auxiliary activity 9 (AA9) LPMOs (GtLPMO9s), whose coding sequences were amplified from cDNA. Due to alternative splicing, two variants of GtLPMO9A seem to be produced, a single-domain variant, GtLPMO9A-1, and...

  17. Open kyphoplasty in the treatment of a painful vertebral lytic lesion with spinal cord compression caused by multiple myeloma: A case report

    OpenAIRE

    Pan, Jun; QIAN, ZHONG-LAI; Sun, Zhi-Yong; Yang, Hui-Lin

    2013-01-01

    Multiple myeloma is a fatal hematological malignancy, with the most common localization being the spine. A 72-year-old male patient presented with progressive back pain and dysfunction of ambulation. Spinal computed tomography (CT) and magnetic resonance imaging (MRI) showed spinal cord compression at the T9-T10 level due to an extensive epidural mass in the spinal canal, a large lytic mass of T7-T12 with extraosseous extension and involvement of T9 and T10 vertebral pedicle and posterior wal...

  18. Development of an efficient method for screening microorganisms by using symbiotic association between Nasutitermes takasagoensis and intestinal microorganisms.

    Science.gov (United States)

    Hayashi, Arata; Aoyagi, Hideki; Kinjyo, Kazuhiko; Yoshimura, Tsuyoshi; Tanaka, Hideo

    2007-07-01

    Screening method of microorganisms that utilized the symbiotic association between insect (Nasutitermes takasagoensis: Nt) and intestinal microorganisms was developed. The existence of desired microorganisms that grew by degrading difficult-to-degrade materials in the gut was detected using survivability of Nt as an indicator. The desired microorganisms were isolated from the survived Nt. It was thought that guts of Nt behave as continuous culture systems whereby microorganisms that cannot degrade diet components are washed out, whereas those that can degrade it are retained and concentrated in the gut. About 60% of Nt fed with phenol artificial diet (PAD) died within 7 days, while 4% of termites survived for 9 days. The structure of intestinal microorganisms of the survived Nt fed with PAD differed from the bacterial communities obtained from enrichment culture (which contained phenol) of wood-feeding Nt. Relatively high colonies (650-times) were detected in the gut of Nt fed on phenol artificial diet compared with those obtained when Nt was fed on wood. Seven denaturing gradient gel electrophoresis (DGGE) bands were detected from gut of wood-feeding Nt, whereas 11 DGGE-bands were detected from that of phenol-feeding Nt. Out of 11 DGGE-bands, 5 of them were sequenced, and bacterial species including phenol-degrading bacteria were identified.

  19. Clinical Manifestations of Kaposi Sarcoma Herpesvirus Lytic Activation: Multicentric Castleman Disease (KSHV–MCD and the KSHV Inflammatory Cytokine Syndrome

    Directory of Open Access Journals (Sweden)

    Mark N. Polizzotto

    2012-03-01

    Full Text Available Soon after the discovery of Kaposi sarcoma (KS-associated herpesvirus (KSHV, it was appreciated that this virus was associated with most cases of multicentric Castleman disease (MCD arising in patients infected with human immunodeficiency virus. It has subsequently been recognized that KSHV–MCD is a distinct entity from other forms of MCD. Like MCD that is unrelated to KSHV, the clinical presentation of KSHV–MCD is dominated by systemic inflammatory symptoms including fevers, cachexia, and laboratory abnormalities including cytopenias, hypoalbuminemia, hyponatremia, and elevated C-reactive protein. Pathologically KSHV–MCD is characterized by polyclonal, IgM-lambda restricted plasmacytoid cells in the intrafollicular areas of affected lymph nodes. A portion of these cells are infected with KSHV and a sizable subset of these cells express KSHV lytic genes including a viral homolog of interleukin-6 (vIL-6. Patients with KSHV–MCD generally have elevated KSHV viral loads in their peripheral blood. Production of vIL-6 and induction of human (h IL-6 both contribute to symptoms, perhaps in combination with overproduction of IL-10 and other cytokines. Until recently, the prognosis of patients with KSHV–MCD was poor. Recent therapeutic advances targeting KSHV-infected B cells with the anti-CD20 monoclonal antibody rituximab and utilizing KSHV enzymes to target KSHV-infected cells have substantially improved patient outcomes. Recently another KSHV-associated condition, the KSHV inflammatory cytokine syndrome (KICS has been described. Its clinical manifestations resemble those of KSHV–MCD but lymphadenopathy is not prominent and the pathologic nodal changes of KSHV–MCD are absent. Patients with KICS exhibit elevated KSHV viral loads and elevation of vIL-6, homolog of human interleukin-6 and IL-10 comparable to those seen in KSHV–MCD; the cellular origin of these is a matter of investigation. KICS may contribute to the inflammatory symptoms

  20. Induction of lytic pathways in T cell clones derived from wild-type or protein tyrosine kinase Fyn mutant mice.

    Science.gov (United States)

    Lancki, D W; Fields, P; Qian, D; Fitch, F W

    1995-08-01

    detected in CD8+ clones derived from fyn-/- mutant mice. Thus, Fyn is not required for expression of these components of antigen specific lysis by CD8+ alloreactive CTL clones. It appears that CD8+ clones that use multiple lytic mechanisms may selectively employ the perforin or Fas-based pathway depending on properties of the target cell or stimulus.(ABSTRACT TRUNCATED AT 400 WORDS)

  1. Lytic HSV-1 infection induces the multifunctional transcription factor Early Growth Response-1 (EGR-1 in rabbit corneal cells

    Directory of Open Access Journals (Sweden)

    McFerrin Harris E

    2011-05-01

    Full Text Available Abstract Background Herpes simplex virus type-1 (HSV-1 infections can cause a number of diseases ranging from simple cold sores to dangerous keratitis and lethal encephalitis. The interaction between virus and host cells, critical for viral replication, is being extensively investigated by many laboratories. In this study, we tested the hypothesis that HSV-1 lytic infection triggers the expression of important multi-functional transcription factor Egr1. The mechanisms of induction are mediated, at least in part, by signaling pathways such as NFκB and CREB. Methods SIRC, VERO, and 293HEK cell lines were infected with HSV-1, and the Egr-1 transcript and protein were detected by RT-PCR and Western blot, respectively. The localization and expression profile of Egr-1 were investigated further by immunofluorescence microscopy analyses. The recruitment of transcription factors to the Egr-1 promoter during infection was studied by chromatin immunoprecipitation (ChIP. Various inhibitors and dominant-negative mutant were used to assess the mechanisms of Egr-1 induction and their effects were addressed by immunofluorescence microscopy. Results Western blot analyses showed that Egr-1 was absent in uninfected cells; however, the protein was detected 24-72 hours post treatment, and the response was directly proportional to the titer of the virus used for infection. Using recombinant HSV-1 expressing EGFP, Egr-1 was detected only in the infected cells. ChIP assays demonstrated that NFкB and cAMP response element binding protein (CREB were recruited to the Egr-1 promoter upon infection. Additional studies showed that inhibitors of NFкB and dominant-negative CREB repressed the Egr-1 induction by HSV-1 infection. Conclusion Collectively, these results demonstrate that Egr-1 is expressed rapidly upon HSV-1 infection and that this novel induction could be due to the NFкB/CREB-mediated transactivation. Egr-1 induction might play a key role in the viral gene

  2. Produção, purificação, clonagem e aplicação de enzimas líticas Production, purification, cloning and application of lytic enzymes

    Directory of Open Access Journals (Sweden)

    Luciana Francisco Fleuri

    2005-10-01

    Full Text Available Lytic enzymes such as beta-1,3 glucanases, proteases and chitinases are able to hydrolyse, respectively, beta-1,3 glucans, mannoproteins and chitin, as well as the cell walls of many yeast species. Lytic enzymes are useful in a great variety of applications including the preparation of protoplasts; the extraction of proteins, enzymes, pigments and functional carbohydrates; pre-treatment for the mechanical rupture of cells; degradation of residual yeast cell mass for the preparation of animal feed; analysis of the yeast cell wall structure and composition; study of the yeast cell wall synthesis and the control of pathogenic fungi. This review presents the most important aspects with respect to lytic enzymes, especially their production, purification, cloning and application.

  3. [Effects of transgenic crops on soil microorganisms: a review].

    Science.gov (United States)

    Zhang, Yan-Jun; Xie, Ming; Peng, De-Liang

    2013-09-01

    The worldwide cultivation of transgenic crops not only provides tremendous economic benefits, but also induces the concern about the potential risks of transgenic crops on soil ecosystem in which microorganisms are involved. The potential effects of transgenic crops on soil microorganisms include the direct effects of the transgenic proteins on non-target soil microorganisms, and the indirect effects of the unintentional changes in the chemical compositions of root exudates induced by the introduction of the exogenous transgenic proteins. Most of the studies on transgenic crops suggested that transgenic crops could affect the quantity and structure of soil microbial populations. However, the perceivable effects on the soil microorganisms are inconsistent, with some in significant and others in non-significant, or some with persistent and others with non-persistent. This paper summarized the effects of different transgenic crops on soil microorganisms, and discussed the factors affecting the assessment reliability, including the species of transgenic crops and the experimental technologies and principles. Some issues needed to be paid special attention to in the future studies were put forward.

  4. Assessment of cellulolytic microorganisms in soils of Nevados Park, Colombia

    Directory of Open Access Journals (Sweden)

    Lizeth Manuela Avellaneda-Torres

    2014-12-01

    Full Text Available A systematized survey was conducted to find soil-borne microbes that degrade cellulose in soils from unique ecosystems, such as the Superpáramo, Páramo, and the High Andean Forest in the Nevados National Natural Park (NNNP, Colombia. These high mountain ecosystems represent extreme environments, such as high levels of solar radiation, low atmospheric pressure, and extreme daily changes in temperature. Cellulolytic activity of the microorganisms was evaluated using qualitative tests, such as growth in selective media followed by staining with congo red and iodine, and quantitative tests to determine the activity of endoglucanase, β-glucosidase, exoglucanase, and total cellulase. Microorganisms were identified using molecular markers, such as the 16S rRNA gene for bacteria and the internal transcribed spacer region (ITS of ribosomal DNA for fungi. Multivariate statistical analysis (MVA was used to select microorganisms with high cellulolytic capacity. A total of 108 microorganisms were isolated from the soils and, in general, the enzymatic activities of fungi were higher than those of bacteria. Our results also found that none of the organisms studied were able to degrade all the components of the cellulose and it is therefore suggested that a combination of bacteria and/or fungi with various enzymatic activities be used to obtain high total cellulolytic activity. This study gives an overview of the potential microorganism that could be used for cellulose degradation in various biotechnological applications and for sustainable agricultural waste treatment.

  5. Capillary isoelectric focusing of native and inactivated microorganisms.

    Science.gov (United States)

    Horká, M; Kubícek, O; Růzicka, F; Holá, V; Malinovská, I; Slais, K

    2007-07-06

    The research of microorganisms includes the development of methods for the inactivation of viruses and other microbes. It also means to efficiently eliminate the infectivity of microorganisms without damage of their integrity and structure. According to the results of the last 5 years the capillary electromigration techniques appear to be very perspective for the comparison of the methods applicable for inactivation in the diagnostics and study of the pathogens. In this paper we suggest the capillary isoelectric focusing of the model microorganisms, Escherichia coli, Staphylococcus epidermidis, Candida albicans and bacteriophage PhiX 174, native or inactivated by different procedures. UV detection and fluorometric detection for the dynamically modified microbes by pyrenebutanoate on the basis of the non-ionogenic tenside were used here. Isoelectric points of native and/or dynamically modified microorganisms and other properties were compared with those obtained after microorganisms inactivation. The segmental injection of the sample pulse enabled the reproducible and efficient capillary isoelectric focusing in different pH gradients. The low-molecular-weight pI markers were used for tracing of the pH gradient.

  6. Mini-review: Inhibition of biofouling by marine microorganisms.

    Science.gov (United States)

    Dobretsov, Sergey; Abed, Raeid M M; Teplitski, Max

    2013-01-01

    Any natural or artificial substratum exposed to seawater is quickly fouled by marine microorganisms and later by macrofouling species. Microfouling organisms on the surface of a substratum form heterogenic biofilms, which are composed of multiple species of heterotrophic bacteria, cyanobacteria, diatoms, protozoa and fungi. Biofilms on artificial structures create serious problems for industries worldwide, with effects including an increase in drag force and metal corrosion as well as a reduction in heat transfer efficiency. Additionally, microorganisms produce chemical compounds that may induce or inhibit settlement and growth of other fouling organisms. Since the last review by the first author on inhibition of biofouling by marine microbes in 2006, significant progress has been made in the field. Several antimicrobial, antialgal and antilarval compounds have been isolated from heterotrophic marine bacteria, cyanobacteria and fungi. Some of these compounds have multiple bioactivities. Microorganisms are able to disrupt biofilms by inhibition of bacterial signalling and production of enzymes that degrade bacterial signals and polymers. Epibiotic microorganisms associated with marine algae and invertebrates have a high antifouling (AF) potential, which can be used to solve biofouling problems in industry. However, more information about the production of AF compounds by marine microorganisms in situ and their mechanisms of action needs to be obtained. This review focuses on the AF activity of marine heterotrophic bacteria, cyanobacteria and fungi and covers publications from 2006 up to the end of 2012.

  7. Identification and Characterization of Extremophile Microorganisms with Significance to Astrobiology

    Science.gov (United States)

    Bej, Asim K.

    2003-01-01

    It is now well recognized that microorganisms thrive in extreme ecological conditions such as geothermal vents, polar region, acid and alkaline lakes, and the cold pressurized depth of the ocean floor of this planet. Morphological, physiological, biochemical and genetic adaptations to extreme environments by these extremophile microorganisms have generated immense interest amongst astrobiologists who increasingly believe in the existence of extraterrestrial life. The evidence collected by NASA's space probe Galileo suggested the presence of liquid water and volcanic activity on Mars and Jupiter's satellite Europa. Volcanic activity provides some of the heat necessary to keep the water on Europa from freezing that could provide important dissolved chemicals needed by living organisms. The possibility of the existence of hypersaline alkaline lakes and evaporites confined within closed volcanic basins and impact craters on Mars, and a layer of liquid water under the ice on Europa provide sufficient 'raison d'etre' to study microorganisms in similar extreme environments on Earth, which could provide us with a model that would help establish the existence of extraterrestrial life on other planetary bodies. The objectives of the summer research project were as follows: (1) application of molecular approaches to help establish new species of extremophile microorganisms isolated from a hypersaline alkaline lake; and (2) identification of a major cold-shock gene (cspA) homolog from a psychrotolerant microorganism, PmagG1.

  8. Biosurfactants Produced by Marine Microorganisms with Therapeutic Applications.

    Science.gov (United States)

    Gudiña, Eduardo J; Teixeira, José A; Rodrigues, Lígia R

    2016-02-18

    Marine microorganisms possess unique metabolic and physiological features and are an important source of new biomolecules, such as biosurfactants. Some of these surface-active compounds synthesized by marine microorganisms exhibit antimicrobial, anti-adhesive and anti-biofilm activity against a broad spectrum of human pathogens (including multi-drug resistant pathogens), and could be used instead of existing drugs to treat infections caused by them. In other cases, these biosurfactants show anti-cancer activity, which could be envisaged as an alternative to conventional therapies. However, marine biosurfactants have not been widely explored, mainly due to the difficulties associated with the isolation and growth of their producing microorganisms. Culture-independent techniques (metagenomics) constitute a promising approach to study the genetic resources of otherwise inaccessible marine microorganisms without the requirement of culturing them, and can contribute to the discovery of novel biosurfactants with significant biological activities. This paper reviews the most relevant biosurfactants produced by marine microorganisms with potential therapeutic applications and discusses future perspectives and opportunities to discover novel molecules from marine environments.

  9. A decay-accelerating factor-binding strain of coxsackievirus B3 requires the coxsackievirus-adenovirus receptor protein to mediate lytic infection of rhabdomyosarcoma cells.

    Science.gov (United States)

    Shafren, D R; Williams, D T; Barry, R D

    1997-12-01

    The composition of the cellular receptor complex for coxsackievirus B3 (CVB3) has been an area of much contention for the last 30 years. Recently, two individual components of a putative CVB3 cellular receptor complex have been identified as (i) decay-accelerating factor (DAF) and (ii) the coxsackievirus-adenovirus receptor protein (CAR). The present study elucidates the individual roles of DAF and CAR in cell entry of CVB3 Nancy. First, we confirm that the DAF-binding phenotype of CVB3 correlates to the presence of key amino acids located in the viral capsid protein, VP2. Second, using antibody blockade, we show that complete protection of permissive cells from infection by high input multiplicities of CVB3 requires a combination of both anti-DAF and anti-CAR antibodies. Finally, it is shown that expression of the CAR protein on the surface of nonpermissive DAF-expressing RD cells renders them highly susceptible to CVB3-mediated lytic infection. Therefore, although the majority of CVB3 Nancy attaches to the cell via DAF, only virus directly interacting with the CAR protein mediates lytic infection. The role of DAF in CVB3 cell infection may be analogous to that recently described for coxsackievirus A21 (D. R. Shafren, D. J. Dorahy, R. A. Ingham, G. F. Burns, and R. D. Barry, J. Virol. 71:4736-4743, 1997), in that DAF may act as a CVB3 sequestration site, enhancing viral presentation to the functional CAR protein.

  10. The HSV-1 Latency-Associated Transcript Functions to Repress Latent Phase Lytic Gene Expression and Suppress Virus Reactivation from Latently Infected Neurons.

    Science.gov (United States)

    Nicoll, Michael P; Hann, William; Shivkumar, Maitreyi; Harman, Laura E R; Connor, Viv; Coleman, Heather M; Proença, João T; Efstathiou, Stacey

    2016-04-01

    Herpes simplex virus 1 (HSV-1) establishes life-long latent infection within sensory neurons, during which viral lytic gene expression is silenced. The only highly expressed viral gene product during latent infection is the latency-associated transcript (LAT), a non-protein coding RNA that has been strongly implicated in the epigenetic regulation of HSV-1 gene expression. We have investigated LAT-mediated control of latent gene expression using chromatin immunoprecipitation analyses and LAT-negative viruses engineered to express firefly luciferase or β-galactosidase from a heterologous lytic promoter. Whilst we were unable to determine a significant effect of LAT expression upon heterochromatin enrichment on latent HSV-1 genomes, we show that reporter gene expression from latent HSV-1 genomes occurs at a greater frequency in the absence of LAT. Furthermore, using luciferase reporter viruses we have observed that HSV-1 gene expression decreases during long-term latent infection, with a most marked effect during LAT-negative virus infection. Finally, using a fluorescent mouse model of infection to isolate and culture single latently infected neurons, we also show that reactivation occurs at a greater frequency from cultures harbouring LAT-negative HSV-1. Together, our data suggest that the HSV-1 LAT RNA represses HSV-1 gene expression in small populations of neurons within the mouse TG, a phenomenon that directly impacts upon the frequency of reactivation and the maintenance of the transcriptionally active latent reservoir.

  11. Genetically Engineered Yeast Expressing a Lytic Peptide from Bee Venom (Melittin) Kills Symbiotic Protozoa in the Gut of Formosan Subterranean Termites.

    Science.gov (United States)

    Husseneder, Claudia; Donaldson, Jennifer R; Foil, Lane D

    2016-01-01

    The Formosan subterranean termite, Coptotermes formosanus Shiraki, is a costly invasive urban pest in warm and humid regions around the world. Feeding workers of the Formosan subterranean termite genetically engineered yeast strains that express synthetic protozoacidal lytic peptides has been shown to kill the cellulose digesting termite gut protozoa, which results in death of the termite colony. In this study, we tested if Melittin, a natural lytic peptide from bee venom, could be delivered into the termite gut via genetically engineered yeast and if the expressed Melittin killed termites via lysis of symbiotic protozoa in the gut of termite workers and/or destruction of the gut tissue itself. Melittin expressing yeast did kill protozoa in the termite gut within 56 days of exposure. The expressed Melittin weakened the gut but did not add a synergistic effect to the protozoacidal action by gut necrosis. While Melittin could be applied for termite control via killing the cellulose-digesting protozoa in the termite gut, it is unlikely to be useful as a standalone product to control insects that do not rely on symbiotic protozoa for survival.

  12. 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.

  13. Functional characterization of a novel lytic phage EcSw isolated from Sus scrofa domesticus and its potential for phage therapy.

    Science.gov (United States)

    Easwaran, Maheswaran; Paudel, Sarita; De Zoysa, Mahanama; Shin, Hyun-Jin

    2015-06-01

    In this study, multi-drug resistant Escherichia coli Sw1 (E. coli Sw1) and active lytic phage EcSw was isolated from feces samples of Sus scrofa domesticus (piglet) suffering from diarrhea. Transmission electron microscopy (TEM) indicated that isolated EcSw belongs to the Myoviridae family with an icosahedral head (80 ± 4) and a long tail (180 ± 5 nm). The EcSw phage genome size was estimated to be approximately 75 Kb of double-stranded DNA (dsDNA). Phage dynamic studies show that the latent period and burst size of EcSw were approximately 20 min and 28 PFU per cell, respectively. Interestingly, the EcSw phage can tolerate a wide range of environmental conditions, such as temperature, pH and ions (Ca(2+) and Mg(2+)). Furthermore, genome sequence analysis revealed that the lytic genes of the EcSw phage are notably similar to those of enterobacteria phages. In addition, phage-antibiotic synergy has notable effects compared with the effects of phages or antibiotics alone. Inhibition of E. coli Sw1 and 0157:H7 strains showed that the limitations of host specificity and infectivity of EcSw. Even though, it has considerable potential for phage therapy for handling the problem of the emergence of multidrug resistant pathogens.

  14. Binding of cellular export factor REF/Aly by Kaposi's sarcoma-associated herpesvirus (KSHV) ORF57 protein is not required for efficient KSHV lytic replication.

    Science.gov (United States)

    Li, Da-Jiang; Verma, Dinesh; Swaminathan, Sankar

    2012-09-01

    Kaposi's sarcoma-associated herpesvirus (KSHV) ORF57 protein is expressed early during lytic KSHV replication, enhances expression of many KSHV genes, and is essential for virus production. ORF57 is a member of a family of proteins conserved among all human and many animal herpesviruses that are multifunctional regulators of gene expression and act posttranscriptionally to increase accumulation of their target mRNAs. The mechanism of ORF57 action is complex and may involve effects on mRNA transcription, stability, and export. ORF57 directly binds to REF/Aly, a cellular RNA-binding protein component of the TREX complex that mediates RNA transcription and export. We analyzed the effects of an ORF57 mutation known to abrogate REF/Aly binding and demonstrate that the REF-binding mutant is impaired in activation of viral mRNAs and noncoding RNAs confined to the nucleus. Although the inability to bind REF leads to decreased ORF57 activity in enhancing gene expression, there is no demonstrable effect on nuclear export of viral mRNA or the ability of ORF57 to support KSHV replication and virus production. These data indicate that REF/Aly-ORF57 interaction is not essential for KSHV lytic replication but may contribute to target RNA stability independent of effects on RNA export, suggesting a novel role for REF/Aly in viral RNA metabolism.

  15. 9 CFR 114.5 - Micro-organisms used as seed.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Micro-organisms used as seed. 114.5... BIOLOGICAL PRODUCTS § 114.5 Micro-organisms used as seed. Micro-organisms used in the preparation of... conditions. A complete record of such micro-organisms shall be kept currently correct and a list submitted...

  16. 40 CFR 725.12 - Identification of microorganisms for Inventory and other listing purposes.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Identification of microorganisms for... MICROORGANISMS General Provisions and Applicability § 725.12 Identification of microorganisms for Inventory and...) Taxonomic designation. The taxonomic designation of a microorganism must be provided for the donor...

  17. Bioprospection of marine microorganisms: potential and challenges for Argentina.

    Science.gov (United States)

    Dionisi, Hebe M; Lozada, Mariana; Olivera, Nelda L

    2012-01-01

    The marine environments of Argentina have a remarkable extension, as well as high biological productivity and biodiversity of both macro- and microorganisms. Despite having a great potential for biotechnological applications, the microorganisms inhabiting these ecosystems remain mostly unexplored and unexploited. In this review, we study the research topics and the interactions among Argentinean laboratories, by analyzing current articles published on biotechnology-related marine microbiology by researchers of this country. In addition, we identify the challenges and opportunities for Argentina to take advantage of the genetic potential of its marine microorganisms. Finally, we suggest possible actions that could improve the development of this research field, as well as the utilization of this knowledge to solve societal needs.

  18. Systems biology for understanding and engineering of heterotrophic oleaginous microorganisms.

    Science.gov (United States)

    Park, Beom Gi; Kim, Minsuk; Kim, Joonwon; Yoo, Heewang; Kim, Byung-Gee

    2017-01-01

    Heterotrophic oleaginous microorganisms continue to draw interest as they can accumulate a large amount of lipids which is a promising feedstock for the production of biofuels and oleochemicals. Nutrient limitation, especially nitrogen limitation, is known to effectively trigger the lipid production in these microorganisms. For the aim of developing improved strains, the mechanisms behind the lipid production have been studied for a long time. Nowadays, system-level understanding of their metabolism and associated metabolic switches is attainable with modern systems biology tools. This work reviews the systems biology studies, based on (i) top-down, large-scale 'omics' tools, and (ii) bottom-up, mathematical modeling methods, on the heterotrophic oleaginous microorganisms with an emphasis on further application to metabolic engineering.

  19. Opportunistic microorganisms in individuals with lesions of denture stomatitis.

    Science.gov (United States)

    Pereira, Cristiane Aparecida; Toledo, Bruna Costa; Santos, Camila Teles; Pereira Costa, Anna Carolina Borges; Back-Brito, Graziella Nuernberg; Kaminagakura, Estela; Jorge, Antonio Olavo Cardoso

    2013-08-01

    The aim of this study was to isolate, quantify, identify, and compare opportunistic microorganisms (Candida and Staphylococcus genera and Enterobacteriaceae/Pseudomonadaceae families) from prosthesis-fitting surfaces, the hard palate, and mouth rinses of individuals wearing removable maxillary prosthesis with (50) and without (50) lesions of denture stomatitis (DS). The strains were collected and identified using phenotypic, biochemical and molecular tests. The counts of microorganisms were significantly higher in the group of individuals with DS (P < 0.05). C. albicans was the most frequently isolated yeast species in both groups, following by C. tropicalis and C. glabrata. Six isolates were identified as C. dubliniensis. S. aureus and S. epidermidis were the most frequent Staphylococcus species in both groups. Klebsiella pneumoniae was the predominant species in both groups. The association between Candida spp. and bacteria isolated in this study with DS suggests that these microorganisms may play important roles in the establishment and persistence of this disease.

  20. The role of microorganisms in coral health, disease and evolution.

    Science.gov (United States)

    Rosenberg, Eugene; Koren, Omry; Reshef, Leah; Efrony, Rotem; Zilber-Rosenberg, Ilana

    2007-05-01

    Coral microbiology is an emerging field, driven largely by a desire to understand, and ultimately prevent, the worldwide destruction of coral reefs. The mucus layer, skeleton and tissues of healthy corals all contain large populations of eukaryotic algae, bacteria and archaea. These microorganisms confer benefits to their host by various mechanisms, including photosynthesis, nitrogen fixation, the provision of nutrients and infection prevention. Conversely, in conditions of environmental stress, certain microorganisms cause coral bleaching and other diseases. Recent research indicates that corals can develop resistance to specific pathogens and adapt to higher environmental temperatures. To explain these findings the coral probiotic hypothesis proposes the occurrence of a dynamic relationship between symbiotic microorganisms and corals that selects for the coral holobiont that is best suited for the prevailing environmental conditions. Generalization of the coral probiotic hypothesis has led us to propose the hologenome theory of evolution.

  1. Accumulation of motile elongated micro-organisms in turbulence

    Science.gov (United States)

    Zhan, Caijuan; Sardina, Gaetano; Lushi, Enkeleida; Brandt, Luca

    2014-01-01

    We study the effect of turbulence on marine life by performing numerical simulations of motile microorganisms, modelled as prolate spheroids, in isotropic homogeneous turbulence. We show that the clustering and patchiness observed in laminar flows, linear shear and vortex flows, are significantly reduced in a three-dimensional turbulent flow mainly because of the complex topology; elongated micro-orgamisms show some level of clustering in the case of swimmers without any preferential alignment whereas spherical swimmers remain uniformly distributed. Micro-organisms with one preferential swimming direction (e.g. gyrotaxis) still show significant clustering if spherical in shape, whereas prolate swimmers remain more uniformly distributed. Due to their large sensitivity to the local shear, these elongated swimmers react slower to the action of vorticity and gravity and therefore do not have time to accumulate in a turbulent flow. These results show how purely hydrodynamic effects can alter the ecology of microorganisms that can vary their shape and their preferential orientation.

  2. Use of Probiotic Microorganisms for Bio-Protective Aims

    Directory of Open Access Journals (Sweden)

    Filiz YANGILAR

    2015-03-01

    Full Text Available It was known that some diseases can be treated as the result of the use of antibiotics in certain periods and at certain dosages while inactivating and deteriorating normal microorganisms performing useful activities in human metabolism (in especially intestinal flora. It was occured that after the use of antibiotics, some defects can be seen resulting from antibiotics (such as allergy, diarrhea, gas formation etc. With this aim, nutraceutics and functional food have gained importance over the last years and consumers began to be interested in probiotics, natural antioxidants, dietary fibres, products with low calorie and cholesterol contents, especially the products containing probioticbacteria. Bacteriocins produced by probiotic bacteria can play important roles as food protective and safeguarding since they can compete with unwanted or pathogen microorganisms survive in the media and colonize in intestines. In this review, is aimed to emphasis bioprotective compounds, advantages and disadvantages of biopreservation method and the importance of the mechanisms of probiotic microorganisms.

  3. Removal of triazine herbicides from freshwater systems using photosynthetic microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Barreiro, O. [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n. 15071 A Coruna (Spain); Rioboo, C. [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n. 15071 A Coruna (Spain); Herrero, C. [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n. 15071 A Coruna (Spain); Cid, A. [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n. 15071 A Coruna (Spain)]. E-mail: cid@udc.es

    2006-11-15

    The uptake of the triazine herbicides, atrazine and terbutryn, was determined for two freshwater photosynthetic microorganisms, the green microalga Chlorella vulgaris and the cyanobacterium Synechococcus elongatus. An extremely rapid uptake of both pesticides was recorded, although uptake rate was lower for the cyanobacterium, mainly for atrazine. Other parameters related to the herbicide bioconcentration capacity of these microorganisms were also studied. Growth rate, biomass, and cell viability in cultures containing herbicide were clearly affected by herbicide uptake. Herbicide toxicity and microalgae sensitivity were used to determine the effectiveness of the bioconcentration process and the stability of herbicide removal. C. vulgaris showed higher bioconcentration capability for these two triazine herbicides than S. elongatus, especially with regard to terbutryn. This study supports the usefulness of such microorganisms, as a bioremediation technique in freshwater systems polluted with triazine herbicides.

  4. Microorganisms as potential corrosion inhibitors of metallic materials

    Directory of Open Access Journals (Sweden)

    Tasić Žaklina Z.

    2016-01-01

    Full Text Available Corrosion presents the destruction of materials through chemical or electrochemical interactions with their environment. Interactions between the metal surface and bacterial cells or products of their metabolic activities can lead to microbially-influenced corrosion. Also, it is known that certain microorganisms can contribute to corrosion inhibition. In accordance to that, the literature dealing with the application of different microorganisms as a potentialy corrosion inhibitors of metals is investigated. Different bacterial strains as a corrosion inhibitor of a metalic materials are examined. Further, the role of extracellular polymeric substances in corrosion behavior of metals is emphasized. Based on the data presented in this work, it can be said that inhibition efficiency depends on microorganism as well as type of metal. Also, it is presented that some bacterial species can be used as a good corrosion inhibitor instead of toxic organic compounds.

  5. Potential role of microorganisms in the pathogenesis of rosacea.

    Science.gov (United States)

    Holmes, Anna D

    2013-12-01

    Rosacea is a skin condition of abnormal inflammation and vascular dysfunction. The active contribution of a microbial agent in the development or progression of rosacea continues to be debated. Research supports the presence of commensal Demodex folliculorum mites at increased density in the skin and associates Helicobacter pylori infection of the gut with rosacea. Fewer studies implicate Staphylococcus epidermidis, Chlamydophila pneumoniae, and the Demodex-associated bacteria Bacillus oleronius. No research, however, provides a mechanism by which colonization by a microorganism translates to manifestation of the condition. Prevailing and emerging principles in the biology of the microbiome and the pathophysiology of rosacea may help to reconcile these lingering questions. Here the microorganisms implicated in rosacea are reviewed and the reaction of the microbiome to inflammation and to changes in microenvironments and macroenvironments are discussed to explain potential roles for microorganisms in rosacea pathophysiology.

  6. Plant development in the absence of epiphytic microorganisms

    Science.gov (United States)

    Kutschera, U.; Koopmann, V.; Grotha, R.

    2002-05-01

    Microorganisms (bacteria, fungi) are common residents of the roots, stems and leaves of higher plants. In order to explore the dependency of plant development on the presence of epiphytic microorganisms, the achenes (seeds) of sunflower (Helianthus annuus L.) were sterilized and germinated under aseptic conditions. The sterility of the seedlings was determined with the agar impression method. In seedlings from non-sterile seeds (control) that were likewise raised in a germ-free environment, all plant organs investigated (stem, cotyledons and primary leaves) were contaminated with bacteria. Hypocotyl elongation was not affected by epiphytic microorganisms. However, the growth rates of the cotyledons and primary leaves were higher in sterile seedlings compared with the control. The implications of this differential inhibition of organ development by epiphytic bacteria that are transmitted via the outer surface of the seed coat are discussed. We conclude that epiphytes in the above-ground phytosphere are not necessary for the development of the sunflower seedling.

  7. 三种白腐菌及其组合菌种木质素降解酶比较研究%Comparative studies on lignin degradation enzymes produced by three species of white-rot fungi and combination of the strains

    Institute of Scientific and Technical Information of China (English)

    段传人; 朱丽平; 姚月良

    2009-01-01

    朱红栓菌Trametes cinnabarina、糙皮侧耳Pleurotus ostreatus、黄孢原毛平革菌Phanerochaete chrysosporium是产生木质素降解酶能力强的菌株.对三种白腐菌及其组合菌种产生木质素降解酶能力和行为进行了比较分析和研究.结果表明,最佳培养方式为液体振荡培养;最佳培养基为酵母膏液体培养基.在产漆酶(laccases,lacs)方面,Pleurotus ostreatus和Phanerochaete chrysosporium的组合菌种的酶活最强,在第6天出现峰值,酶活达到450U/L;在产锰过氧化物酶(manganese peroxidases,maps)方面,Trametes cinnabarina和Pleurotus ostreatus的组合菌种的酶活最强,在第10天出现峰值,酶活达到1050U/L;在产木质素过氧化物酶(lignin peroxidases,lips)方面,Trametes cinnabarina和Phanerochaete chrysosporium的组合菌种的酶活最强,在第8天出现产酶峰值,酶活达到2990U/L.筛选结果表明,组合菌种比单菌种产生的三种主要木质素降解酶的活性强,这为白腐菌高效产酶提供了一条新的途径,并为白腐菌研究领域的后续工作奠定基础.%Trametes cinnabarina, Pleurotus ostreatus and Phanerochaete chrysosporium are high-yielding strains producing lignin degradation enzymes. Comparative studies on lignin degradation enzymes produced by these three species of white-rot fungi and combination of the swains were conducted. The results showed that liquid-shaking culture was the best culture method, yeast extract liquid medium was the best medium. As far as laccase (lacs) production was concerned, the enzyme activities of lacs produced by the combination of Pleurotus ostreatus and Phanerochaete chrysosporium were the highest, reaching 450U/L on day 6; the enzyme activities of manganese peroxidases (mnps) produced by the combination of Trametes cinnabarina and Pleurotus ostreatus were the highest, reaching 1050U/L on day 10; the enzyme activities of lignin peroxidases (lips) produced by the combination of Trametes cinnabarina and

  8. Identification of beer spoilage microorganisms using the MALDI Biotyper platform.

    Science.gov (United States)

    Turvey, Michelle Elizabeth; Weiland, Florian; Meneses, Jon; Sterenberg, Nick; Hoffmann, Peter

    2016-03-01

    Beer spoilage microorganisms present a major risk for the brewing industry and can lead to cost-intensive recall of contaminated products and damage to brand reputation. The applicability of molecular profiling using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) in combination with Biotyper software was investigated for the identification of beer spoilage microorganisms from routine brewery quality control samples. Reference mass spectrum profiles for three of the most common bacterial beer spoilage microorganisms (Lactobacillus lindneri, Lactobacillus brevis and Pediococcus damnosus), four commercially available brewing yeast strains (top- and bottom-fermenting) and Dekkera/Brettanomyces bruxellensis wild yeast were established, incorporated into the Biotyper reference library and validated by successful identification after inoculation into beer. Each bacterial species could be accurately identified and distinguished from one another and from over 5600 other microorganisms present in the Biotyper database. In addition, wild yeast contaminations were rapidly detected and distinguished from top- and bottom-fermenting brewing strains. The applicability and integration of mass spectrometry profiling using the Biotyper platform into existing brewery quality assurance practices within industry were assessed by analysing routine microbiology control samples from a local brewery, where contaminating microorganisms could be reliably identified. Brewery-isolated microorganisms not present in the Biotyper database were further analysed for identification using LC-MS/MS methods. This renders the Biotyper platform a promising candidate for biological quality control testing within the brewing industry as a more rapid, high-throughput and cost-effective technology that can be tailored for the detection of brewery-specific spoilage organisms from the local environment.

  9. Fermentation of various sugars and sugar substitutes by oral microorganisms

    Institute of Scientific and Technical Information of China (English)

    Boonyanit Thaweboon; Sroisiri Thaweboon; Doan Minh Tri

    2011-01-01

    Objective: To examine acid production of caries-associated strains of oral microorganisms and salivary microorganisms from sugar and sugar substitutes. Methods:Standard and clinical strains of Streptococcus mutans (S. mutans), Lactobacillus casei (L. casei) and Candida albicans were incubated in peptone-yeast-extract media containing 1% test sugar (sucrose, glucose, fructose) or sugar substitutes (xylitol, sorbitol, trehalulose and palatinose) at 37 ℃in 5% CO2 for 24-48 h. The pH of each culture was measured and microbial growth was determined as optical density at 660 nm. Paraffin-stimulated saliva collected from high caries-risk persons were added to media containing 10%test sugar or sugar substitutes. The pH of medium was measured at each time interval from 0-90 minutes. Results:All types of sugar and trehalulose could be fermented by all test microorganisms in pH lower than 5.5 except sucrose by standard strain of L. casei. All sugar and sugar substitutes supported growth of all organisms except xylitol for S. mutans. In the fermentation assay by salivary microorganisms, all sugar could be utilized and produced pH< 5.5 within 10 minutes of incubation and the pH drop was prolonged to until 90 minutes. Conversely, xylitol and palatinose were not fermented by microorganisms in saliva. Conclusions:All test microorganisms could ferment sucrose, glucose, fructose and trehalulose to pH lower than 5.5. Sugar alcohols and palatinose were not utilized well by organisms and may be used as sugar substitutes to reduce dental caries incidence. However, further studies particularly clinical investigations are required to evaluate the cariogenicity of these sugar substitutes.

  10. Liquefaction/solubilization processes of Spanish coals by microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Laborda, F.; Monistrol, I.F.; Luna, N.; Fernandez, M. [Madrid Univ. (Spain). Dept. de Microbiologia y Parasitologia

    1997-12-31

    Several fundamental aspects of microbial coal liquefaction/solubilization have been studied in this work. The first one is the mechanisms implicated on coal transformation. During coal solubilization, fungal cells produced extracellular peroxidase, esterase and some times phenol oxidase enzymes which appear to be involved in solubilization. Moreover, the analysis of liquefaction/solubilization products was done. In this regard, a reduction on the average size of humic acids derived from lignite was observed, probably due to depolymerization caused by microorganisms. Finally, microorganisms showed a specific adherence to the coal surface, that seems to promote the microbial attack to coal. (orig.)

  11. Processes of liquefaction/solubilization of Spanish coals by microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Laborda, F.; Monistrol, I.F.; Luna, N.; Fernandez, M. [Universidad de Alcala de Henares, Madrid (Spain). Dept. de Microbiologia y Parasitologia

    1999-07-01

    Several fundamental aspects of microbial coal liquefaction/solubilization were studied. The liquefied/solubilized products from coal by microorganisms were analysed. The liquid products analysed by IR titration and UV/visible spectrometry showed some alterations with regard to the original coal. Humic acids extracted from the liquefied lignite showed a reduction in the average molecular weight and a increase in the condensation index, probably due to depolymerization caused by microorganisms. The mechanisms implicated in coal biosolubilization by two fungal strains, M2 (Trichoderma sp.) and M4 (Penicillium sp.) were also studied. Extracellular peroxidase, esterase and phenoloxidase enzymes appear to be involved in coal solubilization. (orig.)

  12. Study of microorganisms degrading PCB in vegetated contaminated soil

    Directory of Open Access Journals (Sweden)

    Veronika Kurzawova

    2010-12-01

    Full Text Available Removal of PCBs from contaminated soil is one of the challenges ofenvironmental microbiology. In our study, we aimed to isolate,characterize and identify microorganisms from contaminated soiland to find out the plant effect on microbial diversity in theenvironment. Microorganisms were isolated by two ways, directextraction and isolation after cultivation with biphenyl as a solesource of carbon. Isolated bacteria were biochemically characterizedand the composition of ribosomal proteins in bacterial cells wasdetermined by mass spectrometry MALDI-TOF. Bacteria withrequired properties were chosen and the bphA gene was amplifiedand detected. Bacteria with detected bphA gene were then identifiedby 16S rRNA sequence analyses.

  13. Biosynthesis of anti-HCV compounds using thermophilic microorganisms.

    Science.gov (United States)

    Rivero, Cintia W; De Benedetti, Eliana C; Sambeth, Jorge E; Lozano, Mario E; Trelles, Jorge A

    2012-10-01

    This work describes the application of thermophilic microorganisms for obtaining 6-halogenated purine nucleosides. Biosynthesis of 6-chloropurine-2'-deoxyriboside and 6-chloropurine riboside was achieved by Geobacillus stearothermophilus CECT 43 with a conversion of 90% and 68%, respectively. Furthermore, the selected microorganism was satisfactorily stabilized by immobilization in an agarose matrix. This biocatalyst can be reused at least 70 times without significant loss of activity, obtaining 379mg/L of 6-chloropurine-2'-deoxyriboside. The obtained compounds can be used as antiviral agents.

  14. Gut Microorganisms Found Necessary for Successful Cancer Therapy | Poster

    Science.gov (United States)

    By Nancy Parrish, Staff Writer Humans play host to trillions of microorganisms that help our bodies perform basic functions, like digestion, growth, and fighting disease. In fact, bacterial cells outnumber the human cells in our bodies by 10 to 1.1 The tens of trillions of microorganisms thriving in our intestines are known as gut microbiota, and those that are not harmful to us are referred to as commensal microbiota. In a recent paper in Science, NCI scientists described their discovery that, in mice, the presence of commensal microbiota is needed for successful response to cancer therapy.

  15. Collective Motion of Micro-organisms from Field Theoretical Viewpoint

    OpenAIRE

    Nojiri, Shin'ichi; Kawamura, Masako; Sugamoto, Akio

    1995-01-01

    We analyze the collective motion of micro-organisms in the fluid and consider the problem of the red tide. The red tide is produced by the condensation of the micro-organisms, which might be a similar phenomenon to the condensation of the strings. We propose a model of the generation of the red tide. By considering the interaction between the micro- organisms mediated by the velocity fields in the fluid, we derive the Van der Waals type equation of state, where the generation of the red tide ...

  16. Stringy and membranic theory of swimming of micro-organisms

    CERN Document Server

    Kawamura, M; Kawamura, Masako; Sugamoto, Akio

    1996-01-01

    When the swimming of micro-organisms is viewed from the string and membrane theories coupled to the velocity field of the fluid, a number of interesting results are derived; 1) importance of the area (or volume) preserving algebra, 2) usefulness of the N-point Reggeon (membranic) amplitudes, and of the gas to liquid transition in case of the red tide issues, 3) close relation between the red tide issue and the generation of Einstein gravity, and 4) possible understanding of the three different swimming ways of micro-organisms from the singularity structure of the shape space.

  17. Biotechnologies for Marine Oil Spill Cleanup: Indissoluble Ties with Microorganisms

    KAUST Repository

    Mapelli, Francesca

    2017-05-13

    The ubiquitous exploitation of petroleum hydrocarbons (HCs) has been accompanied by accidental spills and chronic pollution in marine ecosystems, including the deep ocean. Physicochemical technologies are available for oil spill cleanup, but HCs must ultimately be mineralized by microorganisms. How environmental factors drive the assembly and activity of HC-degrading microbial communities remains unknown, limiting our capacity to integrate microorganism-based cleanup strategies with current physicochemical remediation technologies. In this review, we summarize recent findings about microbial physiology, metabolism and ecology and describe how microbes can be exploited to create improved biotechnological solutions to clean up marine surface and deep waters, sediments and beaches.

  18. Pathogenic Microorganisms from Raw Milk of Different Animals

    Directory of Open Access Journals (Sweden)

    Letiţia Oprean

    2011-05-01

    Full Text Available Milk is an ideal environment for microbial growth and for this reason the separation of some pathogens is very important. The analysis of milk regarding pathogenic microorganisms is a clear indicator of hygienic quality and this influences the dairy production. Samples of raw milk from cow, goat and sheep were analyzed for pathogens like Staphylococcus aureus and Escherichia coli. The microorganisms found in milk directly affect the human health and can cause a public illness if the unpasteurized milk is used in the food industry.

  19. Lytic activity of the virion-associated peptidoglycan hydrolase HydH5 of Staphylococcus aureus bacteriophage vB_SauS-phiIPLA88

    Directory of Open Access Journals (Sweden)

    Donovan David M

    2011-06-01

    Full Text Available Abstract Background Staphylococcus aureus is a food-borne pathogen and the most common cause of infections in hospitalized patients. The increase in the resistance of this pathogen to antibacterials has made necessary the development of new anti-staphylococcal agents. In this context, bacteriophage lytic enzymes such as endolysins and structural peptidoglycan (PG hydrolases have received considerable attention as possible antimicrobials against gram-positive bacteria. Results S. aureus bacteriophage vB_SauS-phiIPLA88 (phiIPLA88 contains a virion-associated muralytic enzyme (HydH5 encoded by orf58, which is located in the morphogenetic module. Comparative bioinformatic analysis revealed that HydH5 significantly resembled other peptidoglycan hydrolases encoded by staphylococcal phages. The protein consists of 634 amino acid residues. Two putative lytic domains were identified: an N-terminal CHAP (cysteine, histidine-dependent amidohydrolase/peptidase domain (135 amino acid residues, and a C-terminal LYZ2 (lysozyme subfamily 2 domain (147 amino acid residues. These domains were also found when a predicted three-dimensional structure of HydH5 was made which provided the basis for deletion analysis. The complete HydH5 protein and truncated proteins containing only each catalytic domain were overproduced in E. coli and purified from inclusion bodies by subsequent refolding. Truncated and full-length HydH5 proteins were all able to bind and lyse S. aureus Sa9 cells as shown by binding assays, zymogram analyses and CFU reduction analysis. HydH5 demonstrated high antibiotic activity against early exponential cells, at 45°C and in the absence of divalent cations (Ca2+, Mg2+, Mn2+. Thermostability assays showed that HydH5 retained 72% of its activity after 5 min at 100°C. Conclusions The virion-associated PG hydrolase HydH5 has lytic activity against S. aureus, which makes it attractive as antimicrobial for food biopreservation and anti

  20. Murine Gammaherpesvirus 68 ORF48 Is an RTA-Responsive Gene Product and Functions in both Viral Lytic Replication and Latency during In Vivo Infection.

    Science.gov (United States)

    Qi, Jing; Han, Chuanhui; Gong, Danyang; Liu, Ping; Zhou, Sheng; Deng, Hongyu

    2015-06-01

    Replication and transcription activator (RTA) of gammaherpesvirus is an immediate early gene product and regulates the expression of many downstream viral lytic genes. ORF48 is also conserved among gammaherpesviruses; however, its expression regulation and function remained largely unknown. In this study, we characterized the transcription unit of ORF48 from murine gammaherpesvirus 68 (MHV-68) and analyzed its transcriptional regulation. We showed that RTA activates the ORF48 promoter via an RTA-responsive element (48pRRE). RTA binds to 48pRRE directly in vitro and also associates with ORF48 promoter in vivo. Mutagenesis of 48pRRE in the context of the viral genome demonstrated that the expression of ORF48 is activated by RTA through 48pRRE during de novo infection. Through site-specific mutagenesis, we generated an ORF48-null virus and examined the function of ORF48 in vitro and in vivo. The ORF48-null mutation remarkably reduced the viral replication efficiency in cell culture. Moreover, through intranasal or intraperitoneal infection of laboratory mice, we showed that ORF48 is important for viral lytic replication in the lung and establishment of latency in the spleen, as well as viral reactivation from latency. Collectively, our study identified ORF48 as an RTA-responsive gene and showed that ORF48 is important for MHV-68 replication both in vitro and in vivo. The replication and transcription activator (RTA), conserved among gammaherpesviruses, serves as a molecular switch for the virus life cycle. It works as a transcriptional regulator to activate the expression of many viral lytic genes. However, only a limited number of such downstream genes have been uncovered for MHV-68. In this study, we identified ORF48 as an RTA-responsive gene of MHV-68 and mapped the cis element involved. By constructing a mutant virus that is deficient in ORF48 expression and through infection of laboratory mice, we showed that ORF48 plays important roles in different stages of

  1. Mass Disinfection of Documents Affected by Microorganisms: One Practical Experience.

    Science.gov (United States)

    Dobrusina, Svetlana; Velikova, Tatiana

    This paper presents the results of disinfecting treatment of more than 200,000 documents damaged by microorganisms in connection with moving the documents from depositories to a new building of the National Library of Russia. For disinfection, a preparation Metatin GT made by a Swedish firm ACIMA was applied. Metatin GT meets three basic…

  2. Methods for identifying lipoxygenase producing microorganisms on agar plates

    NARCIS (Netherlands)

    Nyyssola, A.; Heshof, R.; Haarmann, T.; Eidner, J.; Westerholm-Parvinen, A.; Langfelder, K.; Kruus, K.; Graaff, de L.H.; Buchert, J.

    2012-01-01

    Plate assays for lipoxygenase producing microorganisms on agar plates have been developed. Both potassium iodide-starch and indamine dye formation methods were effective for detecting soybean lipoxygenase activity on agar plates. A positive result was also achieved using the beta-carotene bleaching

  3. Alkalizing Reactions Streamline Cellular Metabolism in Acidogenic Microorganisms

    Science.gov (United States)

    Arioli, Stefania; Ragg, Enzio; Scaglioni, Leonardo; Fessas, Dimitrios; Signorelli, Marco; Karp, Matti; Daffonchio, Daniele; De Noni, Ivano; Mulas, Laura; Oggioni, Marco; Guglielmetti, Simone; Mora, Diego

    2010-01-01

    An understanding of the integrated relationships among the principal cellular functions that govern the bioenergetic reactions of an organism is necessary to determine how cells remain viable and optimise their fitness in the environment. Urease is a complex enzyme that catalyzes the hydrolysis of urea to ammonia and carbonic acid. While the induction of urease activity by several microorganisms has been predominantly considered a stress-response that is initiated to generate a nitrogen source in response to a low environmental pH, here we demonstrate a new role of urease in the optimisation of cellular bioenergetics. We show that urea hydrolysis increases the catabolic efficiency of Streptococcus thermophilus, a lactic acid bacterium that is widely used in the industrial manufacture of dairy products. By modulating the intracellular pH and thereby increasing the activity of β-galactosidase, glycolytic enzymes and lactate dehydrogenase, urease increases the overall change in enthalpy generated by the bioenergetic reactions. A cooperative altruistic behaviour of urease-positive microorganisms on the urease-negative microorganisms within the same environment was also observed. The physiological role of a single enzymatic activity demonstrates a novel and unexpected view of the non-transcriptional regulatory mechanisms that govern the bioenergetics of a bacterial cell, highlighting a new role for cytosol-alkalizing biochemical pathways in acidogenic microorganisms. PMID:21152088

  4. Mitigating cyanobacterial blooms: how effective are 'effective microorganisms'?

    NARCIS (Netherlands)

    Lürling, M.F.L.L.W.; Tolman, Y.; Euwe, M.

    2009-01-01

    This study examined the effects of 'Effective Microorganisms (EM)' on the growth of cyanobacteria, and their ability to terminate cyanobacterial blooms. The EM was tested in the form of 'mudballs' or 'Bokashi-balls', and as a suspension (EM-A) in laboratory experiments. No growth inhibition was obse

  5. Killer-sensitive coexistence in metapopulations of micro-organisms

    NARCIS (Netherlands)

    Czárán, T.L.; Hoekstra, R.F.

    2003-01-01

    Many micro-organisms are known to produce efficient toxic substances against conspecifics and closely related species. The widespread coexistence of killer (toxin producer) and sensitive (non-producer) strains is a puzzle calling for a theoretical explanation. Based on stochastic cellular automaton

  6. Fossil Microorganisms and Formation of Early Precambrian Weathering Profiles

    Science.gov (United States)

    Rozanov, A. Yu; Astafieva, M. M.; Vrevsky, A. B.; Alfimova, N. A.; Matrenichev, V. A.; Hoover, R. B.

    2009-01-01

    Weathering crusts are the only reliable evidences of the existence of continental conditions. Often they are the only source of information about exogenous processes and subsequently about conditions under which the development of the biosphere occurred. A complex of diverse fossil microorganisms was discovered as a result of Scanning Electron Microscope investigations. The chemical composition of the discovered fossils is identical to that of the host rocks and is represented by Si, Al, Fe, Ca and Mg. Probably, the microorganisms fixed in rocks played the role of catalyst. The decomposition of minerals comprising the rocks and their transformation into clayey (argillaceous) minerals, most likely occurred under the influence of microorganisms. And may be unique weathering crusts of Early Precambrian were formed due to interaction between specific composition of microorganism assemblage and conditions of hypergene transformations. So it is possible to speak about colonization of land by microbes already at that time and about existence of single raw from weathering crusts (Primitive soils) to real soils.

  7. 78 FR 42451 - Animal Feeds Contaminated With Salmonella Microorganisms

    Science.gov (United States)

    2013-07-16

    ... feeds, Cancer, Labeling, Packaging and containers, Polychlorinated biphenyls (PCBs). Therefore, under... HUMAN SERVICES Food and Drug Administration 21 CFR Part 500 Animal Feeds Contaminated With Salmonella Microorganisms AGENCY: Food and Drug Administration, HHS. ACTION: Final rule; removal. SUMMARY: The Food and Drug...

  8. Antibiotic cytotoxic effects of microorganisms isolated from Jachymov uranium mines

    Energy Technology Data Exchange (ETDEWEB)

    Fuska, J.; Fuskova, A. (Slovenska Vysoka Skola Technicka, Bratislava (Czechoslovakia). Chemickotechnologicka Fakulta); Jilek, R. (Vyzkumny Ustav Veterinarniho Lekarstvi, Brno-Medlanky (Czechoslovakia))

    1982-01-01

    Microorganisms were isolated from old relinquished uranium mines in Jachymov; they had been growing for several decades in darkness in temperatures of 5 to 12 degC and relative humidity from 80 to 100%. The concentration of uranium salts in mine waters varied from 10/sup -4/ to 10/sup -5/ g.l/sup -1/, that of Rn in the atmosphere was from 0.04 to 40 Bq.l/sup -1/. Of 324 cultures, 18.8% inhibited the growth of Bacillus subtilis, Escherichia coli and Candida pseudotropicalis and 16.6% that of HeLa cells. The frequency of microorganisms inhibiting the growth of HeLa or Ehrlich ascites cells was markedly higher in this set of cultures than among microorganisms kept in culture collections or isolated from other natural habitats. About 10% of the isolated cultures were mycelia sterilia. The following antibiotics were isolated from microorganisms obtained from uranium mines: frequentin, vermiculin, vermicillin, vermistatin, cytostipin and duclauxin.

  9. Causes and implications of colloid and microorganism retention hysteresis

    Science.gov (United States)

    Experiments were designed to better understand the causes and implications of colloid and microorganism retention hysteresis with transients in solution ionic strength (IS). Saturated packed column experiments were conducted using two sizes of carboxyl modified latex (CML) microspheres (0.1 and 1.1...

  10. The metabolism and biotechnological application of betaine in microorganism.

    Science.gov (United States)

    Zou, Huibin; Chen, Ningning; Shi, Mengxun; Xian, Mo; Song, Yimin; Liu, Junhong

    2016-05-01

    Glycine betaine (betaine) is widely distributed in nature and can be found in many microorganisms, including bacteria, archaea, and fungi. Due to its particular functions, many microorganisms utilize betaine as a functional chemical and have evolved different metabolic pathways for the biosynthesis and catabolism of betaine. As in animals and plants, the principle role of betaine is to protect microbial cells against drought, osmotic stress, and temperature stress. In addition, the role of betaine in methyl group metabolism has been observed in a variety of microorganisms. Recent studies have shown that betaine supplementation can improve the performance of microbial strains used for the fermentation of lactate, ethanol, lysine, pyruvate, and vitamin B12, during which betaine can act as stress protectant or methyl donor for the biosynthesis of structurally complex compounds. In this review, we summarize the transport, synthesis, catabolism, and functions of betaine in microorganisms and discuss potential engineering strategies that employ betaine as a methyl donor for the biosynthesis of complex secondary metabolites such as a variety of vitamins, coenzymes, and antibiotics. In conclusion, the biocompatibility, C/N ratio, abundance, and comprehensive metabolic information of betaine collectively indicate that this molecule has great potential for broad applications in microbial biotechnology.

  11. Production of gaba (γ - aminobutyric acid by microorganisms: a review

    Directory of Open Access Journals (Sweden)

    Radhika Dhakal

    2012-12-01

    Full Text Available GABA (γ-aminobutyric acid is a four carbon non-protein amino acid that is widely distributed in plants, animals and microorganisms. As a metabolic product of plants and microorganisms produced by the decarboxylation of glutamic acid, GABA functions as an inhibitory neurotransmitter in the brain that directly affects the personality and the stress management. A wide range of traditional foods produced by microbial fermentation contain GABA, in which GABA is safe and eco-friendly, and also has the possibility of providing new health-benefited products enriched with GABA. Synthesis of GABA is catalyzed by glutamate decarboxylase, therefore, the optimal fermentation condition is mainly based on the biochemical properties of the enzyme. Major GABA producing microorganisms are lactic acid bacteria (LAB, which make food spoilage pathogens unable to grow and act as probiotics in the gastrointestinal tract. The major factors affecting the production of GABA by microbial fermentation are temperature, pH, fermentation time and different media additives, therefore, these factors are summarized to provide the most up-dated information for effective GABA synthesis. There has been a huge accumulation of knowledge on GABA application for human health accompanying with a demand on natural GABA supply. Only the GABA production by microorganisms can fulfill the demand with GABA-enriched health beneficial foods.

  12. Children's Anthropomorphic and Anthropocentric Ideas about Micro-Organisms

    Science.gov (United States)

    Byrne, Jenny; Grace, Marcus; Hanley, Pam

    2009-01-01

    Different views exist about whether anthropomorphic ideas assist or hinder learning in biology. This paper discusses the anthropomorphic and anthropocentric ideas children have about micro-organisms, and whether they affect their understanding. The research was carried out in primary and secondary schools in the South of England and involved 414…

  13. Factors that Interfere in Dextran Production By Sugarcane Contaminating Microorganisms

    Directory of Open Access Journals (Sweden)

    Maria Celia Oliveira Hauly

    2002-01-01

    Full Text Available Dextrans are polysaccharides produced by microorganisms, specially bacterias from the Leuconostoc genus. Dextrans have a high molecular weigh and most of the glycosidic bonds are a(1®6. For the sugar manufacture, dextran is a problem which changes the quality of sugar and the industry efficiency. Dextrans are synthesized when the sugarcane is spoiled before the harvest period, through the sugarcane fissures, which permit the penetration of microorganisms that deteriorate the sugarcane. This work aims at improving the sugar quality and the industry efficiency by isolating dextran producing microorganisms, comparing the time of burning with the infection index and the dextran concentration in the sugarcane juice. Dextran producing microorganisms were isolated from sugarcane juice during the 97/98; 99/00 and 2001 harvests. The isolated strains were maintained in MRS agar at the temperature of 4°C. The fermentation was carried out in MRS broth for 72 hours at 28°C with 180 rpm. Dextran was analyzed by spectrophotometry at 485 nm. Only three isolated strains showed good dextran production. The average of dextran production in MRS broth was 390 mg%. It was observed that a burning period above 72 hours increases the sugarcane contamination and causes high dextran production, and consequently the reduction of the industry efficiency of the sugar factory.

  14. [Advances in researches of molluscicidal microorganisms against Oncomelania hupensis].

    Science.gov (United States)

    Cheng, Wan-ting; Zhou, Yi-biao; Pan, Xiang; Song, Xiu-xia; Jiang, Qing-wu

    2016-02-01

    The elimination of Oncomelania hupensis snails is important to schistosomiasis control. Recently, the application of molluscicidal organisms is considered as a safe and efficient method for snail elimination. In order to provide scientific evidences for effective control of O. hupensis and schistosomiasis, this paper summarizes the researches of molluscicidal microorganisms against O. hupensis.

  15. Characterisation of microorganisms responsible for EBPR in a ...

    African Journals Online (AJOL)

    Characterisation of microorganisms responsible for EBPR in a sequencing batch reactor by using the 16S rDNA-DGGE method. ... The genomic DNA of samples was extracted as the template and the 16S rDNA genes (V3 region) were ...

  16. Alkalizing reactions streamline cellular metabolism in acidogenic microorganisms.

    Directory of Open Access Journals (Sweden)

    Stefania Arioli

    Full Text Available An understanding of the integrated relationships among the principal cellular functions that govern the bioenergetic reactions of an organism is necessary to determine how cells remain viable and optimise their fitness in the environment. Urease is a complex enzyme that catalyzes the hydrolysis of urea to ammonia and carbonic acid. While the induction of urease activity by several microorganisms has been predominantly considered a stress-response that is initiated to generate a nitrogen source in response to a low environmental pH, here we demonstrate a new role of urease in the optimisation of cellular bioenergetics. We show that urea hydrolysis increases the catabolic efficiency of Streptococcus thermophilus, a lactic acid bacterium that is widely used in the industrial manufacture of dairy products. By modulating the intracellular pH and thereby increasing the activity of β-galactosidase, glycolytic enzymes and lactate dehydrogenase, urease increases the overall change in enthalpy generated by the bioenergetic reactions. A cooperative altruistic behaviour of urease-positive microorganisms on the urease-negative microorganisms within the same environment was also observed. The physiological role of a single enzymatic activity demonstrates a novel and unexpected view of the non-transcriptional regulatory mechanisms that govern the bioenergetics of a bacterial cell, highlighting a new role for cytosol-alkalizing biochemical pathways in acidogenic microorganisms.

  17. Genetic Origins of Mercury Resistance in Great Salt Lake Microorganisms

    OpenAIRE

    Smith, Ashtyn; Wood, Austin; Lam, Chelsea; Butler, Jaimi; Baxter, Bonnie

    2014-01-01

    Extremophiles are a diverse group of organisms, typically Bacteria and Archaea, that can inhabit extreme environments, such as geysers, deserts, and saline lakes. Their abilities to withstand extremely dry, hot, salinic, acidic, and mercuric conditions have made these microorganisms admirable astrobiological models for life on other planets1.

  18. Measuring airborne microorganisms and dust from livestock houses

    NARCIS (Netherlands)

    Yang Zhao, Yang

    2011-01-01

      Airborne transmission has been suspected to be responsible for epidemics of highly infectious disease in livestock production. In such transmission, the pathogenic microorganisms may associate with dust particles. However, the extent to which airborne transmission plays a role in the spread

  19. A spectrophotometric screening method for avermectin oxidizing microorganisms.

    Science.gov (United States)

    Wang, Yuan-Shan; Hu, Qi-Wei; Zheng, Xing-Chang; Zhang, Jian-Fen; Zheng, Yu-Guo

    2017-04-01

    A spectrophotometric screening method for avermectin oxidizing microbes by determination of 4″-oxo-avermectin was established based on the reaction between 4″-oxo-avermectin and 2,4-dinitrophenylhydrazine. Combined with a gradient HPLC assay, microorganisms capable of regioselectively oxidizing avermectin to 4″-oxo-avermectin were successfully obtained by this method.

  20. Biological characterisation of Haliclona (?gellius) sp.: sponge and associated microorganisms.

    NARCIS (Netherlands)

    Sipkema, D.; Holmes, B.; Nichols, S.A.; Blanch, H.W.

    2009-01-01

    We have characterised the northern Pacific undescribed sponge Haliclona (?gellius) sp. based on rDNA of the sponge and its associated microorganisms. The sponge is closely related to Amphimedon queenslandica from the Great Barrier Reef as the near-complete 18S rDNA sequences of both sponges were ide