Detoxification of mercury pollutant leached from spent fluorescent lamps using bacterial strains.

Science.gov (United States)

Al-Ghouti, Mohammad A; Abuqaoud, Reem H; Abu-Dieyeh, Mohammed H

2016-03-01

The spent fluorescent lamps (SFLs) are being classified as a hazardous waste due to having mercury as one of its main components. Mercury is considered the second most toxic heavy metal (arsenic is the first) with harmful effects on animal nervous system as it causes different neurological disorders. In this research, the mercury from phosphor powder was leached, then bioremediated using bacterial strains isolated from Qatari environment. Leaching of mercury was carried out with nitric and hydrochloric acid solutions using two approaches: leaching at ambient conditions and microwave-assisted leaching. The results obtained from this research showed that microwave-assisted leaching method was significantly better in leaching mercury than the acid leaching where the mercury leaching efficiency reached 76.4%. For mercury bio-uptake, twenty bacterial strains (previously isolated and purified from petroleum oil contaminated soils) were sub-cultured on Luria Bertani (LB) plates with mercury chloride to check the bacterial tolerance to mercury. Seven of these twenty strains showed a degree of tolerance to mercury. The bio-uptake capacities of the promising strains were investigated using the mercury leached from the fluorescent lamps. Three of the strains (Enterobacter helveticus, Citrobacter amalonaticus, and Cronobacter muytjensii) showed bio-uptake efficiency ranged from 28.8% to 63.6%. Copyright © 2015 Elsevier Ltd. All rights reserved.

Conductivity-Dependent Strain Response of Carbon Nanotube Treated Bacterial Nanocellulose

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S. Farjana

2013-01-01

Full Text Available This paper reports the strain sensitivity of flexible, electrically conductive, and nanostructured cellulose which was prepared by modification of bacterial cellulose with double-walled carbon nanotubes (DWCNTs and multiwalled carbon nanotubes (MWCNTs. The electrical conductivity depends on the modifying agent and its dispersion process. The conductivity of the samples obtained from bacterial cellulose (BNC pellicles modified with DWCNT was in the range from 0.034 S·cm−1 to 0.39 S·cm−1, and for BNC pellicles modified with MWCNTs it was from 0.12 S·cm−1 to 1.6 S·cm−1. The strain-induced electromechanical response, resistance versus strain, was monitored during the application of tensile force in order to study the sensitivity of the modified nanocellulose. A maximum gauge factor of 252 was found from the highest conductive sample treated by MWCNT. It has been observed that the sensitivity of the sample depends on the conductivity of the modified cellulose.

Characterization and optimization of antibiotic resistant bacterial strains for polyhydroxyalkanoates (phas) production

International Nuclear Information System (INIS)

Rehman, S. U.; Jamil, N.; Hussain, S.

2005-01-01

In this investigation, sugarcane soil, sewage water and soil containing long chain hydrocarbons was screened to obtain bacterial strains that were able to synthesize poly-beta-hydroxyalkanoates (PHA). The potential to synthesize PHA was tested qualitatively by Sudan Black staining of colonies growing in glucose and sucrose. Sixteen bacterial strains were isolated, purified and characterized for Gram reaction, biochemical analysis and PHA production. Isolates showed a wide range of tolerance to different commonly used antibiotics. PHA extraction was done by solvent extraction and hypochlorite digestion method. PHA production was optimized for different nitrogen concentrations. (author)

Carbazole degradation in the soil microcosm by tropical bacterial strains

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Lateef B. Salam

2015-01-01

Full Text Available In a previous study, three bacterial strains isolated from tropical hydrocarbon-contaminated soils and phylogenetically identified as Achromobacter sp. strain SL1, Pseudomonassp. strain SL4 and Microbacterium esteraromaticum strain SL6 displayed angular dioxygenation and mineralization of carbazole in batch cultures. In this study, the ability of these isolates to survive and enhance carbazole degradation in soil were tested in field-moist microcosms. Strain SL4 had the highest survival rate (1.8 x 107 cfu/g after 30 days of incubation in sterilized soil, while there was a decrease in population density in native (unsterilized soil when compared with the initial population. Gas chromatographic analysis after 30 days of incubation showed that in sterilized soil amended with carbazole (100 mg/kg, 66.96, 82.15 and 68.54% were degraded by strains SL1, SL4 and SL6, respectively, with rates of degradation of 0.093, 0.114 and 0.095 mg kg−1 h−1. The combination of the three isolates as inoculum in sterilized soil degraded 87.13% carbazole at a rate of 0.121 mg kg−1 h−1. In native soil amended with carbazole (100 mg/kg, 91.64, 87.29 and 89.13% were degraded by strains SL1, SL4 and SL6 after 30 days of incubation, with rates of degradation of 0.127, 0.121 and 0.124 mg kg−1h−1, respectively. This study successfully established the survivability (> 106 cfu/g detected after 30 days and carbazole-degrading ability of these bacterial strains in soil, and highlights the potential of these isolates as seed for the bioremediation of carbazole-impacted environments.

Regional analysis of potential polychlorinated biphenyl degrading bacterial strains from China

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Jianjun Shuai

Full Text Available ABSTRACT Polychlorinated biphenyls (PCBs, the chlorinated derivatives of biphenyl, are one of the most prevalent, highly toxic and persistent groups of contaminants in the environment. The objective of this study was to investigate the biodegradation of PCBs in northeastern (Heilongjiang Province, northern (Shanxi Province and eastern China (Shanghai municipality. From these areas, nine soil samples were screened for PCB-degrading bacteria using a functional complementarity method. The genomic 16S rDNA locus was amplified and the products were sequenced to identify the bacterial genera. Seven Pseudomonas strains were selected to compare the capacity of bacteria from different regions to degrade biphenyl by HPLC. Compared to the biphenyl content in controls of 100%, the biphenyl content went down to 3.7% for strain P9-324, 36.3% for P2-11, and 20.0% for the other five strains. These results indicate that a longer processing time led to more degradation of biphenyl. PCB-degrading bacterial strains are distributed differently in different regions of China.

Short communication: Antiproliferative effect of wild Lactobacillus strains isolated from fermented foods on HT-29 cells.

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Tuo, Y F; Zhang, L W; Yi, H X; Zhang, Y C; Zhang, W Q; Han, X; Du, M; Jiao, Y H; Wang, S M

2010-06-01

In vitro studies, animal models, epidemiology, and human intervention studies provide evidence that some lactic acid bacteria can reduce the risk of certain cancers. In this study, heat-killed bacterial cells, genomic DNA, and cell wall of 7 wild Lactobacillus strains isolated from traditional fermented foods in western China were tested in vitro for cytotoxicity on colonic cancer cell line HT-29 by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The heat-killed bacterial cells, genomic DNA, and cell wall of the 7 strains exhibited direct antiproliferative activities against HT-29 cells. Among the strains, the cellular components of Lactobacillus coryniformis ssp. torquens T3L exerted marked antiproliferative activities against HT-29 cells. The maximum inhibition rates of HT-29 cells by the heat-killed bacterial cells (1x10(7) cfu/mL), cell wall (20 microg of protein/mL) and genomic DNA (100 microg/mL) of L. coryniformis ssp. torquens T3L were 30, 44.9, and 35.9%, respectively. The results indicate that the heat-killed bacterial cells, cell wall, and genomic DNA of the 7 wild Lactobacillus strains could inhibit the growth of HT-29 cells. 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Antifungal activity of bacterial strains from the rhizosphere of ...

African Journals Online (AJOL)

This study evaluated the antifungal action of biomolecules produced from the secondary metabolism of bacterial strains found in the rhizosphere of semi arid plants against human pathogenic Candida albicans. Crude extracts were obtained using ethyl acetate as an organic solvent and the bioactivity was assessed with a ...

ANTIMICROBIAL POTENTIAL OF GARLIC AND OREGANO EXTRACTS AND ESSENTIAL OILS AGAINST DIFFERENT BACTERIAL STRAINS

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Ionica Deliu

2017-12-01

Full Text Available The modern world is often concerned about the bacterial diseases and the diversity of treatment possibilities. The herbal medicines overreach the medical world because the less number of side effects than synthetic drugs and their low costs. In addition to conventional drugs, the natural remedies can solve exceptional health problems. In this study the antibacterial actions of ethanolic, methanolic and aqueous plant extracts (Allium sativum L. and Origanum vulgare L. were tested. Also, we tested the antimicrobial effects of garlic and oregano essential oils against three bacterial strains. The extracts were tested by diffusion method and certain variants were used. The antibacterial effects were read after 24h of incubation at 37°C. The most obvious effect was observed for oregano essential oil and the smallest growth inhibition was registered for aqueous extracts. The alcoholic extracts were more efficient after concentration by evaporation. The most sensitive bacterial strain was Staphylococcus aureus strain. However the Citrobacter freundii clinical strain had not so high sensitivity at plant extracts, we shall consider the plant extracts as a good alternative to synthetic drugs.

Isolation and characterization of a bacterial strain for aniline ...

African Journals Online (AJOL)

STORAGESEVER

which the microbes enzymatically decompose and utilize in cellular ... dioxygenases, liberating ammonia and subsequently ... others). MATERIALS AND METHODS ... results were then interpreted for bacterial identification according to.

Isolation and characterization of butachlor-catabolizing bacterial strain Stenotrophomonas acidaminiphila JS-1 from soil and assessment of its biodegradation potential.

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Dwivedi, S; Singh, B R; Al-Khedhairy, A A; Alarifi, S; Musarrat, J

2010-07-01

Isolation, characterization and assessment of butachlor-degrading potential of bacterial strain JS-1 in soil. Butachlor-degrading bacteria were isolated using enrichment culture technique. The morphological, biochemical and genetic characteristics based on 16S rDNA sequence homology and phylogenetic analysis confirmed the isolate as Stenotrophomonas acidaminiphila strain JS-1. The strain JS-1 exhibited substantial growth in M9 mineral salt medium supplemented with 3.2 mmol l(-1) butachlor, as a sole source of carbon and energy. The HPLC analysis revealed almost complete disappearance of butachlor within 20 days in soil at a rate constant of 0.17 day(-1) and half-life (t((1/2))) of 4.0 days, following the first-order rate kinetics. The strain JS-1 in stationary phase of culture also produced 21.0 microg ml(-1) of growth hormone indole acetic acid (IAA) in the presence of 500 microg ml(-1) of tryptophan. The IAA production was stimulated at lower concentrations of butachlor, whereas higher concentrations above 0.8 mmol l(-1) were found inhibitory. The isolate JS-1 characterized as Stenotrophomonas acidaminiphila was capable of utilizing butachlor as sole source of carbon and energy. Besides being an efficient butachlor degrader, it substantially produces IAA. The bacterial strain JS-1 has a potential for butachlor remediation with a distinctive auxiliary attribute of plant growth stimulation.

[3H] Thymidine incorporation to estimate growth rates of anaerobic bacterial strains

International Nuclear Information System (INIS)

Winding, A.

1992-01-01

The incorporation of [ 3 H] thymidine by axenic cultures of anaerobic bacteria was investigated as a means to measure growth. The three fermentative strains and one of the methanogenic strains tested incorporated [ 3 H] thymidine during growth. It is concluded that the [ 3 H] thymidine incorporation method underestimates bacterial growth in anaerobic environments

Petroleum-hydrocarbon utilization by native bacterial population ...

African Journals Online (AJOL)

Two Nigerian crude oils (Bonny light and Escravos blend) were exposed to the wastewater canal via oil impregnated membrane filters (0.45 μm diameter) for 21 days in a microcosm experiment. Bacterial petroleum-hydrocarbon utilizers were later harvested from both the millipore membrane filters and laboratory ...

Global Phenotypic Characterization of Effects of Fluoroquinolone Resistance Selection on the Metabolic Activities and Drug Susceptibilities of Clostridium perfringens Strains

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Miseon Park

2014-01-01

Full Text Available Fluoroquinolone resistance affects toxin production of Clostridium perfringens strains differently. To investigate the effect of fluoroquinolone resistance selection on global changes in metabolic activities and drug susceptibilities, four C. perfringens strains and their norfloxacin-, ciprofloxacin-, and gatifloxacin-resistant mutants were compared in nearly 2000 assays, using phenotype microarray plates. Variations among mutant strains resulting from resistance selection were observed in all aspects of metabolism. Carbon utilization, pH range, osmotic tolerance, and chemical sensitivity of resistant strains were affected differently in the resistant mutants depending on both the bacterial genotype and the fluoroquinolone to which the bacterium was resistant. The susceptibilities to gentamicin and erythromycin of all resistant mutants except one increased, but some resistant strains were less susceptible to amoxicillin, cefoxitin, ceftriaxone, chloramphenicol, and metronidazole than their wild types. Sensitivity to ethidium bromide decreased in some resistant mutants and increased in others. Microarray analysis of two gatifloxacin-resistant mutants showed changes in metabolic activities that were correlated with altered expression of various genes. Both the chemical structures of fluoroquinolones and the genomic makeup of the wild types influenced the changes found in resistant mutants, which may explain some inconsistent reports of the effects of therapeutic use of fluoroquinolones on clinical isolates of bacteria.

MALDI-TOF-MS with PLS Modeling Enables Strain Typing of the Bacterial Plant Pathogen Xanthomonas axonopodis

Science.gov (United States)

Sindt, Nathan M.; Robison, Faith; Brick, Mark A.; Schwartz, Howard F.; Heuberger, Adam L.; Prenni, Jessica E.

2018-02-01

Matrix-assisted desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) is a fast and effective tool for microbial species identification. However, current approaches are limited to species-level identification even when genetic differences are known. Here, we present a novel workflow that applies the statistical method of partial least squares discriminant analysis (PLS-DA) to MALDI-TOF-MS protein fingerprint data of Xanthomonas axonopodis, an important bacterial plant pathogen of fruit and vegetable crops. Mass spectra of 32 X. axonopodis strains were used to create a mass spectral library and PLS-DA was employed to model the closely related strains. A robust workflow was designed to optimize the PLS-DA model by assessing the model performance over a range of signal-to-noise ratios (s/n) and mass filter (MF) thresholds. The optimized parameters were observed to be s/n = 3 and MF = 0.7. The model correctly classified 83% of spectra withheld from the model as a test set. A new decision rule was developed, termed the rolled-up Maximum Decision Rule (ruMDR), and this method improved identification rates to 92%. These results demonstrate that MALDI-TOF-MS protein fingerprints of bacterial isolates can be utilized to enable identification at the strain level. Furthermore, the open-source framework of this workflow allows for broad implementation across various instrument platforms as well as integration with alternative modeling and classification algorithms.

Synergism between hydrogen peroxide and seventeen acids against six bacterial strains.

Science.gov (United States)

Martin, H; Maris, P

2012-09-01

The objective of this study was to evaluate the bactericidal efficacy of hydrogen peroxide administered in combination with 17 mineral and organic acids authorized for use in the food industry. The assays were performed on a 96-well microplate using a microdilution technique based on the checkerboard titration method. The six selected strains were reference strains and strains representative of contaminating bacteria in the food industry. Each synergistic hydrogen peroxide/acid combination found after 5-min contact time at 20°C in distilled water was then tested in conditions simulating four different use conditions. Thirty-two combinations were synergistic in distilled water; twenty-five of these remained synergistic with one or more of the four mineral and organic interfering substances selected. Hydrogen peroxide/formic acid combination was synergistic for all six bacterial strains in distilled water and remained synergistic with interfering substances. Six other combinations maintained their synergistic effect in the presence of an organic load but only for one or two bacterial strains. Synergistic combinations of disinfectants were revealed, among them the promising hydrogen peroxide/formic acid combination. A rapid screening method was proposed and used to reveal the synergistic potential of disinfectant and/or sanitizer combinations. © 2012 ANSES Fougères Laboratory Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

Biotransformation of tetracycline by a novel bacterial strain Stenotrophomonas maltophilia DT1.

Science.gov (United States)

Leng, Yifei; Bao, Jianguo; Chang, Gaofeng; Zheng, Han; Li, Xingxing; Du, Jiangkun; Snow, Daniel; Li, Xu

2016-11-15

Although several abiotic processes have been reported that can transform antibiotics, little is known about whether and how microbiological processes may degrade antibiotics in the environment. This work isolated one tetracycline degrading bacterial strain, Stenotrophomonas maltophilia strain DT1, and characterized the biotransformation of tetracycline by DT1 under various environmental conditions. The biotransformation rate was the highest when the initial pH was 9 and the reaction temperature was at 30°C, and can be described using the Michaelis-Menten model under different initial tetracycline concentrations. When additional substrate was present, the substrate that caused increased biomass resulted in a decreased biotransformation rate of tetracycline. According to disk diffusion tests, the biotransformation products of tetracycline had lower antibiotic potency than the parent compound. Six possible biotransformation products were identified, and a potential biotransformation pathway was proposed that included sequential removal of N-methyl, carbonyl, and amine function groups. Results from this study can lead to better estimation of the fate and transport of antibiotics in the environment and has the potential to be utilized in designing engineering processes to remove tetracycline from water and soil. Copyright © 2016 Elsevier B.V. All rights reserved.

Volatile emissions from Mycobacterium avium subsp. paratuberculosis mirror bacterial growth and enable distinction of different strains.

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Phillip Trefz

Full Text Available Control of paratuberculosis in livestock is hampered by the low sensitivity of established direct and indirect diagnostic methods. Like other bacteria, Mycobacterium avium subsp. paratuberculosis (MAP emits volatile organic compounds (VOCs. Differences of VOC patterns in breath and feces of infected and not infected animals were described in first pilot experiments but detailed information on potential marker substances is missing. This study was intended to look for characteristic volatile substances in the headspace of cultures of different MAP strains and to find out how the emission of VOCs was affected by density of bacterial growth. One laboratory adapted and four field strains, three of MAP C-type and one MAP S-type were cultivated on Herrold's egg yolk medium in dilutions of 10(-0, 10(-2, 10(-4 and 10(-6. Volatile substances were pre-concentrated from the headspace over the MAP cultures by means of Solid Phase Micro Extraction (SPME, thermally desorbed from the SPME fibers and separated and identified by means of GC-MS. Out of the large number of compounds found in the headspace over MAP cultures, 34 volatile marker substances could be identified as potential biomarkers for growth and metabolic activity. All five MAP strains could clearly be distinguished from blank culture media by means of emission patterns based on these 34 substances. In addition, patterns of volatiles emitted by the reference strain were significantly different from the field strains. Headspace concentrations of 2-ethylfuran, 2-methylfuran, 3-methylfuran, 2-pentylfuran, ethyl acetate, 1-methyl-1-H-pyrrole and dimethyldisulfide varied with density of bacterial growth. Analysis of VOCs emitted from mycobacterial cultures can be used to identify bacterial growth and, in addition, to differentiate between different bacterial strains. VOC emission patterns may be used to approximate bacterial growth density. In a perspective volatile marker substances could be used to

Volatile emissions from Mycobacterium avium subsp. paratuberculosis mirror bacterial growth and enable distinction of different strains.

Science.gov (United States)

Trefz, Phillip; Koehler, Heike; Klepik, Klaus; Moebius, Petra; Reinhold, Petra; Schubert, Jochen K; Miekisch, Wolfram

2013-01-01

Control of paratuberculosis in livestock is hampered by the low sensitivity of established direct and indirect diagnostic methods. Like other bacteria, Mycobacterium avium subsp. paratuberculosis (MAP) emits volatile organic compounds (VOCs). Differences of VOC patterns in breath and feces of infected and not infected animals were described in first pilot experiments but detailed information on potential marker substances is missing. This study was intended to look for characteristic volatile substances in the headspace of cultures of different MAP strains and to find out how the emission of VOCs was affected by density of bacterial growth. One laboratory adapted and four field strains, three of MAP C-type and one MAP S-type were cultivated on Herrold's egg yolk medium in dilutions of 10(-0), 10(-2), 10(-4) and 10(-6). Volatile substances were pre-concentrated from the headspace over the MAP cultures by means of Solid Phase Micro Extraction (SPME), thermally desorbed from the SPME fibers and separated and identified by means of GC-MS. Out of the large number of compounds found in the headspace over MAP cultures, 34 volatile marker substances could be identified as potential biomarkers for growth and metabolic activity. All five MAP strains could clearly be distinguished from blank culture media by means of emission patterns based on these 34 substances. In addition, patterns of volatiles emitted by the reference strain were significantly different from the field strains. Headspace concentrations of 2-ethylfuran, 2-methylfuran, 3-methylfuran, 2-pentylfuran, ethyl acetate, 1-methyl-1-H-pyrrole and dimethyldisulfide varied with density of bacterial growth. Analysis of VOCs emitted from mycobacterial cultures can be used to identify bacterial growth and, in addition, to differentiate between different bacterial strains. VOC emission patterns may be used to approximate bacterial growth density. In a perspective volatile marker substances could be used to diagnose MAP

Characterization of rumen bacterial strains isolated from enrichments of rumen content in the presence of propolis.

Science.gov (United States)

de Aguiar, Sílvia Cristina; Zeoula, Lucia Maria; do Prado, Odimari Pricila Pires; Arcuri, Pedro Braga; Forano, Evelyne

2014-11-01

Propolis presents many biological properties, including antibacterial activities, and has been proposed as an additive in ruminant nutrition. Twenty bacterial strains, previously isolated from enrichments of Brazilian cow rumen contents in the presence of different propolis extracts (LLOS), were characterized using phenotyping and 16S rRNA identification. Seven strains were assigned to Streptococcus sp., most likely S. bovis, and were all degrading starch. One amylolytic lactate-utilizing strain of Selenomonas ruminantium was also found. Two strains of Clostridium bifermentans were identified and showed proteolytic activity. Two strains were assigned to Mitsuokella jalaludinii and were saccharolytic. One strain belonged to a Bacillus species and seven strains were affiliated with Escherichia coli. All of the 20 strains were able to use many sugars, but none of them were able to degrade the polysaccharides carboxymethylcellulose and xylans. The effect of three propolis extracts (LLOS B1, C1 and C3) was tested on the in vitro growth of four representative isolates of S. bovis, E. coli, M. jalaludinii and C. bifermentans. The growth of S. bovis, E. coli and M. jalaludinii was not affected by the three propolis extracts at 1 mg ml(-1). C. bifermentans growth was completely inhibited at this LLOS concentration, but this bacterium was partially resistant at lower concentrations. LLOS C3, with the lower concentration of phenolic compounds, was a little less inhibitory than B1 and C1 on this strain.

Effect of Aqueous Garlic Extract (AGE) and gamma irradiation on some Bacterial Strains

International Nuclear Information System (INIS)

Awny, N.M; Tawfik, Z.S; Abu Nor, S.M; El-Saled, K.M.

2005-01-01

In the present study the sensitivity of four bacterial strains; Salmonella typhimurium, Escherichia coli, Bacillus subtilis and Bacillus pumilus were tested towards the antibacterial effect of aqueous garlic extract (AGE) with different concentration. The results indicated that, the Gram positive spore forming strains, Bacillus subtilis and Bacillus pumilus treated with AGE from 0 to 70μ1/m1 were more resistant than Gram negative non-spore forming ones, Salmonella typhimurium and Escherichia coli treated with AGE from 0 to 24 μ1/m1. The effect of AGE treatment on the radiosensitivity of the tested bacterial strains showed that, AGE treatment before γ-irradiation induced a higher protection than treatment immediately after γ-irradiation. The ultrastructure configuration of untreated strains, treated with AGE or irradiation and combination between AGE and Irradiation, were investigated using transmission electron microscope (TEM). The results indicated that, ultra-structures configuration of the cells treated with AGE before irradiation appeared with less damage than those of cells irradiated without AGE treatment

Fluorometric determination of ethidium bromide efflux kinetics in Escherichia coli

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Monteiro Gabriel A

2009-10-01

Full Text Available Abstract Background Efflux pump activity has been associated with multidrug resistance phenotypes in bacteria, compromising the effectiveness of antimicrobial therapy. The development of methods for the early detection and quantification of drug transport across the bacterial cell wall is a tool essential to understand and overcome this type of drug resistance mechanism. This approach was developed to study the transport of the efflux pump substrate ethidium bromide (EtBr across the cell envelope of Escherichia coli K-12 and derivatives, differing in the expression of their efflux systems. Results EtBr transport across the cell envelope of E. coli K-12 and derivatives was analysed by a semi-automated fluorometric method. Accumulation and efflux of EtBr was studied under limiting energy supply (absence of glucose and low temperature and in the presence and absence of the efflux pump inhibitor, chlorpromazine. The bulk fluorescence variations were also observed by single-cell flow cytometry analysis, revealing that once inside the cells, leakage of EtBr does not occur and that efflux is mediated by active transport. The importance of AcrAB-TolC, the main efflux system of E. coli, in the extrusion of EtBr was evidenced by comparing strains with different levels of AcrAB expression. An experimental model was developed to describe the transport kinetics in the three strains. The model integrates passive entry (influx and active efflux of EtBr, and discriminates different degrees of efflux between the studied strains that vary in the activity of their efflux systems, as evident from the calculated efflux rates: = 0.0173 ± 0.0057 min-1; = 0.0106 ± 0.0033 min-1; and = 0.0230 ± 0.0075 min-1. Conclusion The combined use of a semi-automated fluorometric method and an experimental model allowed quantifying EtBr transport in E. coli strains that differ in their overall efflux activity. This methodology can be used for the early detection of differences in

Screening of bacterial strains capable of converting biodiesel-derived raw glycerol into 1,3-propanediol, 2,3-butanediol and ethanol

Energy Technology Data Exchange (ETDEWEB)

Metsoviti, Maria; Paramithiotis, Spiros; Drosinos, Eleftherios H.; Galiotou-Panayotou, Maria; Nychas, George-John E.; Papanikolaou, Seraphim [Department of Food Science and Technology, Agricultural University of Athens, Athens (Greece); Zeng, An-Ping [Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology (TUHH), Hamburg (Germany)

2012-02-15

The ability of bacterial strains to assimilate glycerol derived from biodiesel facilities to produce metabolic compounds of importance for the food, textile and chemical industry, such as 1,3-propanediol (PD), 2,3-butanediol (BD) and ethanol (EtOH), was assessed. The screening of 84 bacterial strains was performed using glycerol as carbon source. After initial trials, 12 strains were identified capable of consuming raw glycerol under anaerobic conditions, whereas 5 strains consumed glycerol under aerobiosis. A plethora of metabolic compounds was synthesized; in anaerobic batch-bioreactor cultures PD in quantities up to 11.3 g/L was produced by Clostridium butyricum NRRL B-23495, while the respective value was 10.1 g/L for a newly isolated Citrobacter freundii. Adaptation of Cl. butyricum at higher initial glycerol concentration resulted in a PD{sub max} concentration of {proportional_to}32 g/L. BD was produced by a new Enterobacter aerogenes isolate in shake-flask experiments, under fully aerobic conditions, with a maximum concentration of {proportional_to}22 g/L which was achieved at an initial glycerol quantity of 55 g/L. A new Klebsiella oxytoca isolate converted waste glycerol into mixtures of PD, BD and EtOH at various ratios. Finally, another new C. freundii isolate converted waste glycerol into EtOH in anaerobic batch-bioreactor cultures with constant pH, achieving a final EtOH concentration of 14.5 g/L, a conversion yield of 0.45 g/g and a volumetric productivity of {proportional_to}0.7 g/L/h. As a conclusion, the current study confirmed the utilization of biodiesel-derived raw glycerol as an appropriate substrate for the production of PD, BD and EtOH by several newly isolated bacterial strains under different experimental conditions. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

[Co-occurence of indol-producing bacterial strains in the vagina of women infected with Chlamydia trachomatis].

Science.gov (United States)

Romanik, Małgorzata; Martirosian, Gayane; Wojciechowska-Wieja, Anna; Cieślik, Katarzyna; Kaźmierczak, Wojciech

2007-08-01

The aim of this study was to determine if cervicitis, caused by Chlamydia trachomatis (C. trachomatis), has an influence on the frequency of occurrence of selected aerobic and anaerobic bacterial strains, connected with etiology of aerobic vaginitis (AV) and bacterial vaginosis (BV). Indole-producing bacteria have received particular attention due to their possibly inductive role in chronic cervicitis caused by C. trachomatis. The swabs from vagina and cervical canal have been obtained from 122 women (aged 18-40). The presence of C. trachomatis antigen had been detected and diagnosed with the help of direct immunofluorescence, BV with Amesl and Nugent criteria, whereas the AV with Donders criteria. The identification of the bacterial strains isolated from vagina has been performed according to classical microbiological diagnostics. Disruption of vaginal microflora (4-10 in Nugent score) was determined in 11,5% of observed women. AV was diagnosed in 4.5% women with chlamydial cervicitis, BV was diagnosed in 10.9% and 5.45% of these women, on the basis of Amsel and Nugent criteria respectively. Indole-producing bacterial strains connected with BV and AV (Peptostreptococcus anaerobius, Propionibacterium acnes, Escherichia coli) have been isolated significantly more often from vagina of women infected with C trachomatis (p = 0.0405, chi2 = 4.20) and these findings confirm co-importance of indole-producing bacterial strains in cervicitis caused by C trachomatis .

Occurrence of Antibiotic resistance in some bacterial strains due to gamma radiation, heavy metals or food preservatives

International Nuclear Information System (INIS)

Mattar, Z.A.; Bashandy, A.S.

2006-01-01

The susceptibility of bacterial strains (B. cereus, Staph. aureus, Escherichia coli and Salmonella) against 10 different antibiotics that are commonly used against food borne pathogens was studied. All the tested strains were observed to tolerate up to 100 mg/l copper sulphate or lead acetate, and there was a positive correlations between the tolerance to high levels of Cu or Pb and multiple antibiotic resistance was investigated. When the food preservatives (potassium sorbate or sodium benzoate) were added to the growth medium at different concentrations, the bacterial strains were able to tolerate up to 1000 ppm potassium sorbate or sodium benzoate (MIC). The antibiotic resistance of these strains was increased when grown on media supplemented with the MIC of sodium sorbate or potassium benzoate. When these bacterial strains were irradiated at dose levels of 1 or 3 or 5 KGy and examined for antibiotic sensitivity, a correlation was observed between the increases of radiation dose up to 5 KGy and the antibiotic resistance in all the studied strains

Eradication of the corrosion-causing bacterial strains Desulfovibrio vulgaris and Desulfovibrio desulfuricans using photodisinfection

Energy Technology Data Exchange (ETDEWEB)

Street, C.N.; Gibbs, A.J. [Biocorrosion Solutions Inc., Edmonton, AB (Canada)

2010-07-01

Microbiologically influenced corrosion (MIC) can cause oil and gas pipelines to fail prematurely. The free-floating bacteria collects on the inner pipeline surface to form complex adherent biofilms. This study evaluated the use of photodisinfection as a means of treating 2 sulfate-reducing bacterial strains known to contribute to MIC. The sulfate-reducing strains Desulfovibrio vulgaris and Desulfovibrio desulfuricans were studied experimentally to a concentration of 10{sup 7} colony-forming units per millimeter. Bacterial inocula was made to an optical density of 0.150 at 420 nm in order to assess biofilm growth. The study showed that photodisinfection was able to eradicate more than 99 per cent of the bacterial populations prepared in the study. The method was highly effective in removing the biofilms known to cause MIC in oil and gas pipelines. A close-loop dynamic flow system model will be prepared to evaluate the ability of photodisinfection to inhibit bacterially-influenced corrosion of steel coupons. 24 refs., 3 tabs., 1 fig.

Distinct Bacterial Composition Associated with Different Laboratory-cultured Aiptasia Strains Across Two Thermal Conditions

KAUST Repository

Ahmed, Hanin

2018-05-01

Coral reefs are crucial for the ecological sustainability of the oceans, yet, increasing sea surface temperature is threatening these ecosystems globally. Microbial communities associated with corals have become a recent research focus, as the associated microbiome may contribute to coral resilience to environmental stressors, e.g., heat stress. However, research in this area is hampered by the difficulty of working with corals. This study aims to use Aiptasia, a sea anemone, as a tractable laboratory model system to study the role of the coral microbiome. Analyses of the bacterial compositions associated with different Aiptasia strains across two temperatures (25 °C and 32 °C), based on 16S rRNA gene sequencing. This study aims also to identify a “core” microbiome associated with heat stress acclimation, as well as host-specific differences. In general, results showed that bacterial composition associated with Aiptasia strains differs significantly with temperature. Higher bacterial diversity and richness were observed when all Aiptasia strains were placed under heat stress. Moreover, results showed an increase in beta diversity and dispersion of bacterial communities in response to heat stress. These changes in the bacterial composition are in line with the recently described “Anna Karenina principle” for animal microbiomes, which suggests that the microbiomes of unhealthy individuals vary more than healthy and stable individuals. This study further shows that while temperature had the greatest effect on structuring the bacterial compositions, there were some variations better attributed to batch and host effects. This suggests that technical aspects have to be carefully addressed in the framework of microbiome studies. Members of a putative “core” microbiome associated with 32 °C Aiptasia have been identified as indicator species of heat stress (i.e., Francisella sp.,). Previous reports have shown that these indicator taxa are associated with

Biodegradation of petroleum oil by certain bacterial strains

International Nuclear Information System (INIS)

Zakaria, A.E.M.

1998-01-01

Balaeam base oil was chosen as a model oil in the present study through which some abiotic treatments were implemented aiming at attenuating its naphthenic and aromatic contents; such as the adsorptive technique and the gamma-irradiation technique . In an attempt to apply the biodegrading bacteria as oil pollutant bio indicators upon coastal water samples, a correlation between hydrocarbon concentration and the relative enumeration of the bacterial oil degraders was detected for some litter locations along the mediterranean Sea shore west and east Delta, Suez canal. and suez gulf. 24 petroleum utilizing bacterial isolates were isolated from El-Zayteia port (suez) and identified by morphological, physiological and environmental examination . the biodegradation capacity of the isolates towards the chosen model oil and its separate components was studied in comparison with the standard isolate pseudomonas aeruginosa. Further, the role of the bacterial plasmids taking part in the biodegradation process was investigated as well

Bioremediation of crude oil polluted seawater by a hydrocarbon-degrading bacterial strain immobilized on chitin and chitosan flakes

International Nuclear Information System (INIS)

Gentili, A.R.; Cubitto, M.A.; Ferrero, M.; Rodriguez, M.S.

2006-01-01

In this laboratory-scale study, we examined the potential of chitin and chitosan flakes obtained from shrimp wastes as carrier material for a hydrocarbon-degrading bacterial strain. Flakes decontamination, immobilization conditions and the survival of the immobilized bacterial strain under different storage temperatures were evaluated. The potential of immobilized hydrocarbon-degrading bacterial strain for crude oil polluted seawater bioremediation was tested in seawater microcosms. In terms of removal percentage of crude oil after 15 days, the microcosms treated with the immobilized inoculants proved to be the most successful. The inoculants formulated with chitin and chitosan as carrier materials improved the survival and the activity of the immobilized strain. It is important to emphasize that the inoculants formulated with chitin showed the best performance during storage and seawater bioremediation. (author)

Antimicrobial sensitivity and frequency of DRUG resistance among bacterial strains isolated from cancer patients

International Nuclear Information System (INIS)

Faiz, M.; Bashir, T.

2004-01-01

Blood stream infections (bacteremia) is potentially life threatening. Concomitant with a change in the incidence and epidemiology of infecting organisms, there has been an increase in resistance to many antibiotic compounds. The widespread emergence of resistance among bacterial pathogens has an impact on our ability to treat patients effectively. The changing spectrum of microbial pathogens and widespread emergence of microbial resistance to antibiotic drugs has emphasized the need to monitor the prevalence of resistance in these strains. In the present study frequency of isolation of clinically significant bacteria and their susceptibility and resistance pattern against a wide range of antimicrobial drugs from positive blood cultures collected during 2001-2003 was studied. A total of 102 consecutive isolates were found with 63% gram positive and 44% gram negative strains. The dominating pathogens were Staphylococcus aureus (51%), Streptococci (31%), Pseudomonas (40%), Proteus (13%), Klebsiella (13%). The isolated strains were tested against a wide range of antibiotics belonging to cephalosporins, aminoglycosides and quinolone derivative group by disk diffusion method. It has been observed that isolated strains among gram positive and negative strains showed different level of resistance against aminoglycosides and cephalosporin group of antibiotics with gram positives showing highest number and frequency of resistance against aminoglycosides (40-50%) and cephalosporins.(35-45%) whereas cephalosporins were found to be more effective against gram negatives with low frequency of resistant strains. Cabapenem and quinolone derivative drugs were found to be most effective among other groups in both gram positive and negative strains with 23-41% strains found sensitive to these two drugs. The frequency of sensitive strains against aminoglycoside and cephalosporin in gram negative and gram positive strains were found to be decreasing yearwise with a trend towards an

Methyl bromide residues in fumigated cocoa beans with particular reference to inorganic bromide

International Nuclear Information System (INIS)

Adomako, D.

1976-01-01

Inorganic bromide residues and 14 C-labelled methylated products (expressed as CH 3 Br equivalent) in cocoa beans fumigated with [ 14 C]-methyl bromide have been determined by radiometric and chemical methods. Determination of 14 C by direct combustion in an oxygen chamber followed by liquid scintillation counting confirmed previous findings with respect to the magnitude, distribution and chemical nature of the residues. Although recovery of added bromide was good, the values of total bromide obtained by the chemical method were only half of those estimated from the total residual 14 C-activity. This is attributed to loss of organic (presumably, protein-bound) bromide. In agreement with the total 14 C-labelled residue contents, total bromide in shells was 20 times greater than that in nibs. The low levels of residues in the nib (12ppm as CH 3 Br equivalent, 10ppm Br) and the further reduction of organic residues by roasting suggest that no toxicological and nutritional hazards may be expected from fumigation of cocoa beans with methyl bromide. (author)

The Mechanism for Type I Interferon Induction by Mycobacterium tuberculosis is Bacterial Strain-Dependent.

Directory of Open Access Journals (Sweden)

Kirsten E Wiens

2016-08-01

Full Text Available Type I interferons (including IFNαβ are innate cytokines that may contribute to pathogenesis during Mycobacterium tuberculosis (Mtb infection. To induce IFNβ, Mtb must gain access to the host cytosol and trigger stimulator of interferon genes (STING signaling. A recently proposed model suggests that Mtb triggers STING signaling through bacterial DNA binding cyclic GMP-AMP synthase (cGAS in the cytosol. The aim of this study was to test the generalizability of this model using phylogenetically distinct strains of the Mtb complex (MTBC. We infected bone marrow derived macrophages with strains from MTBC Lineages 2, 4 and 6. We found that the Lineage 6 strain induced less IFNβ, and that the Lineage 2 strain induced more IFNβ, than the Lineage 4 strain. The strains did not differ in their access to the host cytosol and IFNβ induction by each strain required both STING and cGAS. We also found that the three strains shed similar amounts of bacterial DNA. Interestingly, we found that the Lineage 6 strain was associated with less mitochondrial stress and less mitochondrial DNA (mtDNA in the cytosol compared with the Lineage 4 strain. Treating macrophages with a mitochondria-specific antioxidant reduced cytosolic mtDNA and inhibited IFNβ induction by the Lineage 2 and 4 strains. We also found that the Lineage 2 strain did not induce more mitochondrial stress than the Lineage 4 strain, suggesting that additional pathways contribute to higher IFNβ induction. These results indicate that the mechanism for IFNβ by Mtb is more complex than the established model suggests. We show that mitochondrial dynamics and mtDNA contribute to IFNβ induction by Mtb. Moreover, we show that the contribution of mtDNA to the IFNβ response varies by MTBC strain and that additional mechanisms exist for Mtb to induce IFNβ.

Variable Responses to Carbon Utilization between Planktonic and Biofilm Cells of a Human Carrier Strain of Salmonella enterica Serovar Typhi.

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Kalaivani Kalai Chelvam

Full Text Available Salmonella enterica serovar Typhi (S. Typhi is a foodborne pathogen that causes typhoid fever and infects only humans. The ability of S. Typhi to survive outside the human host remains unclear, particularly in human carrier strains. In this study, we have investigated the catabolic activity of a human carrier S. Typhi strain in both planktonic and biofilm cells using the high-throughput Biolog Phenotype MicroArray, Minimum Biofilm Eradication Concentration (MBEC biofilm inoculator (96-well peg lid and whole genome sequence data. Additional strains of S. Typhi were tested to further validate the variation of catabolism in selected carbon substrates in the different bacterial growth phases. The analyzes of the carbon utilization data indicated that planktonic cells of the carrier strain, S. Typhi CR0044 could utilize a broader range of carbon substrates compared to biofilm cells. Pyruvic acid and succinic acid which are related to energy metabolism were actively catabolised in the planktonic stage compared to biofilm stage. On the other hand, glycerol, L-fucose, L-rhamnose (carbohydrates and D-threonine (amino acid were more actively catabolised by biofilm cells compared to planktonic cells. Notably, dextrin and pectin could induce strong biofilm formation in the human carrier strain of S. Typhi. However, pectin could not induce formation of biofilm in the other S. Typhi strains. Phenome data showed the utilization of certain carbon substrates which was supported by the presence of the catabolism-associated genes in S. Typhi CR0044. In conclusion, the findings showed the differential carbon utilization between planktonic and biofilm cells of a S. Typhi human carrier strain. The differences found in the carbon utilization profiles suggested that S. Typhi uses substrates mainly found in the human biliary mucus glycoprotein, gallbladder, liver and cortex of the kidney of the human host. The observed diversity in the carbon catabolism profiles among

Systematic determination of the mosaic structure of bacterial genomes: species backbone versus strain-specific loops

Directory of Open Access Journals (Sweden)

Gendrault-Jacquemard A

2005-07-01

Full Text Available Abstract Background Public databases now contain multitude of complete bacterial genomes, including several genomes of the same species. The available data offers new opportunities to address questions about bacterial genome evolution, a task that requires reliable fine comparison data of closely related genomes. Recent analyses have shown, using pairwise whole genome alignments, that it is possible to segment bacterial genomes into a common conserved backbone and strain-specific sequences called loops. Results Here, we generalize this approach and propose a strategy that allows systematic and non-biased genome segmentation based on multiple genome alignments. Segmentation analyses, as applied to 13 different bacterial species, confirmed the feasibility of our approach to discern the 'mosaic' organization of bacterial genomes. Segmentation results are available through a Web interface permitting functional analysis, extraction and visualization of the backbone/loops structure of documented genomes. To illustrate the potential of this approach, we performed a precise analysis of the mosaic organization of three E. coli strains and functional characterization of the loops. Conclusion The segmentation results including the backbone/loops structure of 13 bacterial species genomes are new and available for use by the scientific community at the URL: http://genome.jouy.inra.fr/mosaic.

Limited diffusive fluxes of substrate facilitate coexistence of two competing bacterial strains

DEFF Research Database (Denmark)

Dechesne, Arnaud; Or, D.; Smets, Barth F.

2008-01-01

. It has been proposed, but never unambiguously experimentally tested, that a low substrate diffusive flux would impact bacterial diversity, by promoting the coexistence between slow-growing bacteria and their potentially faster-growing competitors. We used a simple experimental system, based on a Petri...... dish and a perforated Teflon((R)) membrane to control diffusive fluxes of substrate (benzoate) whilst permitting direct observation of bacterial colonies. The system was inoculated with prescribed strains of Pseudomonas, whose growth was quantified by microscopic monitoring of the fluorescent proteins...

Exploring the Potentiality of Novel Rhizospheric Bacterial Strains against the Rice Blast Fungus Magnaporthe oryzae

Science.gov (United States)

Amruta, Narayanappa; Prasanna Kumar, M. K.; Puneeth, M. E.; Sarika, Gowdiperu; Kandikattu, Hemanth Kumar; Vishwanath, K.; Narayanaswamy, Sonnappa

2018-01-01

Rice blast caused by Magnaporthe oryzae is a major disease. In the present study, we aimed to identify and evaluate the novel bacterial isolates from rice rhizosphere for biocontrol of M. oryzae pathogen. Sixty bacterial strains from the rice plant’s rhizosphere were tested for their biocontrol activity against M. oryzae under in vitro and in vivo. Among them, B. amyloliquefaciens had significant high activity against the pathogen. The least disease severity and highest germination were recorded in seeds treated with B. amyloliquefaciens UASBR9 (0.96 and 98.00%) compared to untreated control (3.43 and 95.00%, respectively) under in vivo condition. These isolates had high activity of enzymes in relation to growth promoting activity upon challenge inoculation of the pathogen. The potential strains were identified based on 16S rRNA gene sequencing and dominance of these particular genes were associated in Bacillus strains. These strains were also confirmed for the presence of antimicrobial peptide biosynthetic genes viz., srfAA (surfactin), fenD (fengycin), spaS (subtilin), and ituC (iturin) related to secondary metabolite production (e.g., AMPs). Overall, the results suggested that application of potential bacterial strains like B. amyloliquefaciens UASBR9 not only helps in control of the biological suppression of one of the most devastating rice pathogens, M. grisea but also increases plant growth along with a reduction in application of toxic chemical pesticides. PMID:29628819

Effects of Bacterial Strains to Inhibit Growth of Phytophthora pistaciae under Different Electrical Conductivities

Directory of Open Access Journals (Sweden)

Moslem Hajabdolahi

2018-06-01

Full Text Available Root and crown rot (gummosis is known as the most destructive disease affecting pistachio in Iran. The efficiency of bacterial strains to reduce the growth rate of Phytophthora pistaciae was studied under different electrical conductivities (EC, 0, 2, 4, 8, 12 ds/m. Soil and rhizosphere samples were collected from pistachio growing regions in Kerman province, Iran, during 2011 - 2012. Overall, the strains of bacteria were presented in all sampling areas in both infected and uninfected orchards. Out of 400 bacterial isolates, 63% and 37% were collected from soil and rhizosphere samples, respectively. Among 400 bacterial isolates, 19 exhibited the highest ability to reduce the growth of P. pistaciae in dual culture, volatile and non-volatile compounds, though by different degrees. The degrees of inhibitory activities against mycelial growth of P. pistaciae by Pseudomonas fluorescens strains ranged from 40 to 97.5%, 8 to 97.5% and 7.5 to 90% in dual culture, non-volatile and volatile assays, respectively. The Bacillus subtilis strains reduced the growth of P. pistaciae by 22-92.5%, 17-85%, 21-92.5% in dual culture, non-volatile and volatile assays, respectively. The negative effects of ECs on the growth of P. pistaciae in modified CMA were observed in 8 and 12 ECs. ECs had no effect until 8 ds/m on the growth of P. pistaciae, while the mycelial growth decreased by ECs higher than 8 ds/m. No mycelial growth was observed at EC 14 ds/m. There were significant differences between different bacterial isolates, ECs and their interactions on the mycelial growth of P. pistaciae. The highest mycelial suppression belonged to isolates Nos. 123 and 112 in dual culture, volatile and non-volatile compounds test. More research is required to understand the native mechanisms involved in biological control under natural conditions in pistachio orchards

Evaluation of different lactic acid bacterial strains for probiotic characteristics

OpenAIRE

B. Srinu,; T. Madhava Rao,; P. V. Mallikarjuna Reddy; K. Kondal Reddy

2013-01-01

Objective: The objective of the present study was to collect different Lactic acid bacterial strains from culture collection centers and screen their functional probiotic characteristics such as acid tolerance, bile tolerance, antibacterial activity and antibiotic sensitivity for their commercial use. Materials and Methods: Acid and bile tolerence of selected LAB(Lactic acid bacteria) was determined. The antibiotic resistance of Lactobacillus species was assessed using different antibiotic di...

Antibacterial activity of fumaria indica (hausskn.) pugsley against selected bacterial strains

International Nuclear Information System (INIS)

Toor, Y.; Nawaz, K.; Hussain, K.

2015-01-01

Antibacterial properties of methanolic extracts of F. indica prepared in different doses against seven Gram-positive and Gram-negative bacterial strains i.e. Streptococcus pyogenes, Staphylococcus aureus (1), Staphylococcus aureus (2), Shigella sonnei, Escherichia coli (1), Escherichia coli (2) and Neisseria gonorrhoeae using agar well diffusion method (inhibition zone measurements) compared to gentamicin as standard antibiotic. Results showed significant activities against the test organisms with overall satisfactory statistics. Streptococcus pyogenes, Staphylococcus aureus strains as well as Neisseria gonorrhoeae showed more inhibition to methanolic extracts of F. indica. Minimum inhibitory as well as minimum bactericidal concentrations against all strains except Shigella sonnei were also recorded. Studies showed promising horizons for the use of F. indica as an active antibacterial component in modern drug formulations. (author)

Evaluation of indigenous bacterial strains for biocontrol of the frogeye leaf spot of soya bean caused by Cercospora sojina.

Science.gov (United States)

Simonetti, E; Carmona, M A; Scandiani, M M; García, A F; Luque, A G; Correa, O S; Balestrasse, K B

2012-08-01

Assessment of biological control of Cercospora sojina, causal agent of frogeye leaf spot (FLS) of soya bean, using three indigenous bacterial strains, BNM297 (Pseudomonas fluorescens), BNM340 and BNM122 (Bacillus amyloliquefaciens). From cultures of each bacterial strain, cell suspensions and cell-free supernatants were obtained and assayed to determine their antifungal activity against C. sojina. Both mycelial growth and spore germination in vitro were more strongly inhibited by bacterial cell suspensions than by cell-free supernatants. The Bacillus strains BNM122 and BNM340 inhibited the fungal growth to a similar degree (I ≈ 52-53%), while cells from P. fluorescens BNM297 caused a lesser reduction (I ≈ 32-34%) in the fungus colony diameter. The foliar application of the two Bacillus strains on soya bean seedlings, under greenhouse conditions, significantly reduced the disease severity with respect to control soya bean seedlings and those sprayed with BNM297. This last bacterial strain was not effective in controlling FLS in vivo. Our data demonstrate that the application of antagonistic bacteria may be a promising and environmentally friendly alternative to control the FLS of soya bean.   To our knowledge, this is the first report of biological control of C. sojina by using native Bacillus strains. © 2012 The Authors. Letters in Applied Microbiology © 2012 The Society for Applied Microbiology.

Detection of antibiotic resistance in clinical bacterial strains from pets

OpenAIRE

Poeta, P.; Rodrigues, J.

2008-01-01

The identification of different bacterial strains and the occurrence of antibiotic resistance were investigated in several infection processes of pets as skin abscess with purulent discharge, bronco alveolar fluid, earwax, urine, mammary, and eye fluid. Streptococcus spp. and Staphylococcus spp. were the most detected in the different samples. A high frequency of antimicrobial resistance has been observed and this could reflect the wide use of antimicrobials in pets, making the effectiveness ...

Bacterial Utilization of Petroleum in Liquid and Simulated Soil ...

African Journals Online (AJOL)

... by the weight of extracted residual oil indicated that the extents of oil removal in the stimulated and/or bioaugmented soils were significantly high in relation to unsupplemented and uninoculated controls. Keywords: Bacterial utilization, Petroleum in liquid, Petroleum in soil, Environments Bio-Research Vol. 6 (2) 2008: pp.

Evaluation of insecticidal activity of a bacterial strain, Serratia sp. EML-SE1 against diamondback moth.

Science.gov (United States)

Jeong, Hyung Uk; Mun, Hye Yeon; Oh, Hyung Keun; Kim, Seung Bum; Yang, Kwang Yeol; Kim, Iksoo; Lee, Hyang Burm

2010-08-01

To identify novel bioinsecticidal agents, a bacterial strain, Serratia sp. EML-SE1, was isolated from a dead larva of the lepidopteran diamondback moth (Plutella xylostella) collected from a cabbage field in Korea. In this study, the insecticidal activity of liquid cultures in Luria-Bertani broth (LBB) and nutrient broth (NB) of a bacterial strain, Serratia sp. EML-SE1 against thirty 3rd and 4th instar larvae of the diamondback moth was investigated on a Chinese cabbage leaf housed in a round plastic cage (Ø 10 x 6 cm). 72 h after spraying the cabbage leaf with LBB and NB cultures containing the bacterial strain, the mortalities of the larvae were determined to be 91.7% and 88.3%, respectively. In addition, the insecticidal activity on potted cabbage containing 14 leaves in a growth cage (165 x 83 x 124 cm) was found to be similar to that of the plastic cage experiment. The results of this study provided valuable information on the insecticidal activity of the liquid culture of a Serratia species against the diamondback moth.

Effect of CuO Nanoparticles over Isolated Bacterial Strains from Agricultural Soil

International Nuclear Information System (INIS)

Concha-Guerrero, S.I.; Pinon-Castillo, H.A.; Luna-Velasco, A.; Orrantia-Borunda, E.; Brito, E.M.S.; Tarango-Rivero, S.H.; Caretta, C.A.; Duran, R.

2014-01-01

The increased use of the nanoparticles (NPs) on several processes is notorious. In contrast the eco toxicological effects of NPs have been scarcely studied. The main current researches are related to the oxide metallic NPs. In the present work, fifty-six bacterial strains were isolated from soil, comprising 17 different OTUs distributed into 3 classes: Bacilli (36 strains), Flavobacteria (2 strains), and Gamma proteobacteria (18 strains). Copper oxide nanoparticles (CuONPs) were synthesized using a process of chemical precipitation. The obtained CuONPs have a spherical shape and primary size less than 17 nm. Twenty-one strains were used to evaluate the cytotoxicity of CuONPs and 11 of these strains showed high sensibility. Among those 11 strains, 4 (Brevibacillus later osporus strain CSS8, Chryseobacterium indoltheticum strain CSA28, and Pantoea ananatis strains CSA34 and CSA35) were selected to determine the kind of damage produced. The CuONPs toxic effect was observed at expositions over 25 mg·L -1 and the damage to cell membrane above 160 mg·L -1 . The electron microscopy showed the formation of cavities, holes, membrane degradation, blebs, cellular collapse, and lysis. These toxic effects may probably be due to the ions interaction, the oxide-reduction reactions, and the generation of reactive species

Beneficial role of hydrophytes in removing Cr(VI) from wastewater in association with chromate-reducing bacterial strains Ochrobactrum intermedium and Brevibacterium.

Science.gov (United States)

Faisal, Muhammad; Hasnain, Shahida

2005-01-01

This study deals with the use of three chromium-resistant bacterial strains (Ochrobactrum intermedium CrT-1, Brevibacterium CrT-13, and CrM-1) in conjunction with Eichornia crassipes for the removal of toxic chromium from wastewater. Bacterial strains resulted in reduced uptake of chromate into inoculated plants as compared to noninoculated control plants. In the presence of different heavy metals, chromium uptake into the plants was 28.7 and 7.15% less at an initial K2CrO4 concentration of 100 and 500 microg ml(-1) in comparison to a metal free chromium solution. K2CrO4 uptake into the plant occurred at different pHs tested, but maximum uptake was observed at pH 5. Nevertheless, the bacterial strains caused some decrease in chromate uptake into the plants, but the combined effect of plants and bacterial strains conduce more removal of Cr(VI) from the solution.

Programmable removal of bacterial strains by use of genome-targeting CRISPR-Cas systems.

Science.gov (United States)

Gomaa, Ahmed A; Klumpe, Heidi E; Luo, Michelle L; Selle, Kurt; Barrangou, Rodolphe; Beisel, Chase L

2014-01-28

CRISPR (clustered regularly interspaced short palindromic repeats)-Cas (CRISPR-associated) systems in bacteria and archaea employ CRISPR RNAs to specifically recognize the complementary DNA of foreign invaders, leading to sequence-specific cleavage or degradation of the target DNA. Recent work has shown that the accidental or intentional targeting of the bacterial genome is cytotoxic and can lead to cell death. Here, we have demonstrated that genome targeting with CRISPR-Cas systems can be employed for the sequence-specific and titratable removal of individual bacterial strains and species. Using the type I-E CRISPR-Cas system in Escherichia coli as a model, we found that this effect could be elicited using native or imported systems and was similarly potent regardless of the genomic location, strand, or transcriptional activity of the target sequence. Furthermore, the specificity of targeting with CRISPR RNAs could readily distinguish between even highly similar strains in pure or mixed cultures. Finally, varying the collection of delivered CRISPR RNAs could quantitatively control the relative number of individual strains within a mixed culture. Critically, the observed selectivity and programmability of bacterial removal would be virtually impossible with traditional antibiotics, bacteriophages, selectable markers, or tailored growth conditions. Once delivery challenges are addressed, we envision that this approach could offer a novel means to quantitatively control the composition of environmental and industrial microbial consortia and may open new avenues for the development of "smart" antibiotics that circumvent multidrug resistance and differentiate between pathogenic and beneficial microorganisms. Controlling the composition of microbial populations is a critical aspect in medicine, biotechnology, and environmental cycles. While different antimicrobial strategies, such as antibiotics, antimicrobial peptides, and lytic bacteriophages, offer partial solutions

Novel Accurate Bacterial Discrimination by MALDI-Time-of-Flight MS Based on Ribosomal Proteins Coding in S10-spc-alpha Operon at Strain Level S10-GERMS

Science.gov (United States)

Tamura, Hiroto; Hotta, Yudai; Sato, Hiroaki

2013-08-01

Matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is one of the most widely used mass-based approaches for bacterial identification and classification because of the simple sample preparation and extremely rapid analysis within a few minutes. To establish the accurate MALDI-TOF MS bacterial discrimination method at strain level, the ribosomal subunit proteins coded in the S 10-spc-alpha operon, which encodes half of the ribosomal subunit protein and is highly conserved in eubacterial genomes, were selected as reliable biomarkers. This method, named the S10-GERMS method, revealed that the strains of genus Pseudomonas were successfully identified and discriminated at species and strain levels, respectively; therefore, the S10-GERMS method was further applied to discriminate the pathovar of P. syringae. The eight selected biomarkers (L24, L30, S10, S12, S14, S16, S17, and S19) suggested the rapid discrimination of P. syringae at the strain (pathovar) level. The S10-GERMS method appears to be a powerful tool for rapid and reliable bacterial discrimination and successful phylogenetic characterization. In this article, an overview of the utilization of results from the S10-GERMS method is presented, highlighting the characterization of the Lactobacillus casei group and discrimination of the bacteria of genera Bacillus and Sphingopyxis despite only two and one base difference in the 16S rRNA gene sequence, respectively.

The effect of rhamnolipid biosurfactant produced by Pseudomonas fluorescens on model bacterial strains and isolates from industrial wastewater.

Science.gov (United States)

Vasileva-Tonkova, Evgenia; Sotirova, Anna; Galabova, Danka

2011-02-01

In this study, the effect of rhamnolipid biosurfactant produced by Pseudomonas fluorescens on bacterial strains, laboratory strains, and isolates from industrial wastewater was investigated. It was shown that biosurfactant, depending on the concentration, has a neutral or detrimental effect on the growth and protein release of model Gram (+) strain Bacillus subtilis 168. The growth and protein release of model Gram (-) strain Pseudomonas aeruginosa 1390 was not influenced by the presence of biosurfactant in the medium. Rhamnolipid biosurfactant at the used concentrations supported the growth of some slow growing on hexadecane bacterial isolates, members of the microbial community. Changes in cell surface hydrophobicity and permeability of some Gram (+) and Gram (-) isolates in the presence of rhamnolipid biosurfactant were followed in experiments in vitro. It was found that bacterial cells treated with biosurfactant became more or less hydrophobic than untreated cells depending on individual characteristics and abilities of the strains. For all treated strains, an increase in the amount of released protein was observed with increasing the amount of biosurfactant, probably due to increased cell permeability as a result of changes in the organization of cell surface structures. The results obtained could contribute to clarify the relationships between members of the microbial community as well as suggest the efficiency of surface properties of rhamnolipid biosurfactant from Pseudomonas fluorescens making it potentially applicable in bioremediation of hydrocarbon-polluted environments.

Evaluation of gastrointestinal bacterial population for the production of holocellulose enzymes for biomass deconstruction.

Science.gov (United States)

Asem, Dhaneshwaree; Leo, Vincent Vineeth; Passari, Ajit Kumar; Tonsing, Mary Vanlalhruaii; Joshi, J Beslin; Uthandi, Sivakumar; Hashem, Abeer; Abd Allah, Elsayed Fathi; Singh, Bhim Pratap

2017-01-01

The gastrointestinal (GI) habitat of ruminant and non-ruminant animals sustains a vast ensemble of microbes that are capable of utilizing lignocellulosic plant biomass. In this study, an indigenous swine (Zovawk) and a domesticated goat (Black Bengal) were investigated to isolate bacteria having plant biomass degrading enzymes. After screening and enzymatic quantification of eighty-one obtained bacterial isolates, Serratia rubidaea strain DBT4 and Aneurinibacillus aneurinilyticus strain DBT87 were revealed as the most potent strains, showing both cellulase and xylanase production. A biomass utilization study showed that submerged fermentation (SmF) of D2 (alkaline pretreated pulpy biomass) using strain DBT4 resulted in the most efficient biomass deconstruction with maximum xylanase (11.98 U/mL) and FPase (0.5 U/mL) activities (55°C, pH 8). The present study demonstrated that bacterial strains residing in the gastrointestinal region of non-ruminant swine are a promising source for lignocellulose degrading microorganisms that could be used for biomass conversion.

Evaluation of gastrointestinal bacterial population for the production of holocellulose enzymes for biomass deconstruction.

Directory of Open Access Journals (Sweden)

Dhaneshwaree Asem

Full Text Available The gastrointestinal (GI habitat of ruminant and non-ruminant animals sustains a vast ensemble of microbes that are capable of utilizing lignocellulosic plant biomass. In this study, an indigenous swine (Zovawk and a domesticated goat (Black Bengal were investigated to isolate bacteria having plant biomass degrading enzymes. After screening and enzymatic quantification of eighty-one obtained bacterial isolates, Serratia rubidaea strain DBT4 and Aneurinibacillus aneurinilyticus strain DBT87 were revealed as the most potent strains, showing both cellulase and xylanase production. A biomass utilization study showed that submerged fermentation (SmF of D2 (alkaline pretreated pulpy biomass using strain DBT4 resulted in the most efficient biomass deconstruction with maximum xylanase (11.98 U/mL and FPase (0.5 U/mL activities (55°C, pH 8. The present study demonstrated that bacterial strains residing in the gastrointestinal region of non-ruminant swine are a promising source for lignocellulose degrading microorganisms that could be used for biomass conversion.

Genetic Variation of the SusC/SusD Homologs from a Polysaccharide Utilization Locus Underlies Divergent Fructan Specificities and Functional Adaptation in Bacteroides thetaiotaomicron Strains.

Science.gov (United States)

Joglekar, Payal; Sonnenburg, Erica D; Higginbottom, Steven K; Earle, Kristen A; Morland, Carl; Shapiro-Ward, Sarah; Bolam, David N; Sonnenburg, Justin L

2018-01-01

Genomic differences between gut-resident bacterial strains likely underlie significant interindividual variation in microbiome function. Traditional methods of determining community composition, such as 16S rRNA gene amplicon sequencing, fail to capture this functional diversity. Metagenomic approaches are a significant step forward in identifying strain-level sequence variants; however, given the current paucity of biochemical information, they too are limited to mainly low-resolution and incomplete functional predictions. Using genomic, biochemical, and molecular approaches, we identified differences in the fructan utilization profiles of two closely related Bacteroides thetaiotaomicron strains. B. thetaiotaomicron 8736 ( Bt-8736 ) contains a fructan polysaccharide utilization locus (PUL) with a divergent susC / susD homolog gene pair that enables it to utilize inulin, differentiating this strain from other characterized Bt strains. Transfer of the distinct pair of susC / susD genes from Bt-8736 into the noninulin using type strain B. thetaiotaomicron VPI-5482 resulted in inulin use by the recipient strain, Bt ( 8736-2 ). The presence of the divergent susC / susD gene pair alone enabled the hybrid Bt ( 8736-2 ) strain to outcompete the wild-type strain in vivo in mice fed an inulin diet. Further, we discovered that the susC / susD homolog gene pair facilitated import of inulin into the periplasm without surface predigestion by an endo-acting enzyme, possibly due to the short average chain length of inulin compared to many other polysaccharides. Our data builds upon recent reports of dietary polysaccharide utilization mechanisms found in members of the Bacteroides genus and demonstrates how the acquisition of two genes can alter the functionality and success of a strain within the gut. IMPORTANCE Dietary polysaccharides play a dominant role in shaping the composition and functionality of our gut microbiota. Dietary interventions using these m icrobiota- a

[Characteristics of natural strains of naphthalene-utilizing bacteria of the genus Pseudomonas].

Science.gov (United States)

Levchuk, A A; Vasilenko, S L; Bulyga, I M; Titok, M A; Thomas, K M

2005-01-01

Sixty-three strains of bacteria capable of utilizing naphthalene as the sole source of carbon and energy were isolated from 137 samples of soil taken in different sites in Belarus. All isolated bacteria contained extrachromosomal genetic elements of 45 to 150 kb in length. It was found that bacteria of 31 strains contained the IncP-9 incompatibility group plasmids, bacteria of one strain carried a plasmid containing replicons IncP-9 and IncP-7, and bacteria of 31 strains contained unidentified plasmids. Primary identification showed that the hosts of plasmids of naphthalene biodegradation are fluorescent bacteria of the genus Pseudomonas (P. putida and P. aeruginosa; a total of 47 strains) and unidentified nonfluorescent microorganisms (a total of 16 strains). In addition to the ability to utilize naphthalene, some strains exhibited the ability to stimulate the growth and development of the root system of Secale cereale.

Simultaneous Microcystis Algicidal and Microcystin Degrading Capability by a Single Acinetobacter Bacterial Strain.

Science.gov (United States)

Li, Hong; Ai, Hainan; Kang, Li; Sun, Xingfu; He, Qiang

2016-11-01

Measures for removal of toxic harmful algal blooms often cause lysis of algal cells and release of microcystins (MCs). In this study, Acinetobacter sp. CMDB-2 that exhibits distinct algal lysing activity and MCs degradation capability was isolated. The physiological response and morphological characteristics of toxin-producing Microcystis aeruginosa, the dynamics of intra- and extracellular MC-LR concentration were studied in an algal/bacterial cocultured system. The results demonstrated that Acinetobacter sp. CMDB-2 caused thorough decomposition of algal cells and impairment of photosynthesis within 24 h. Enhanced algal lysis and MC-LR release appeared with increasing bacterial density from 1 × 10 3 to 1 × 10 7 cells/mL; however, the MC-LR was reduced by nearly 94% within 14 h irrespective of bacterial density. Measurement of extracellular and intracellular MC-LR revealed that the toxin was decreased by 92% in bacterial cell incubated systems relative to control and bacterial cell-free filtrate systems. The results confirmed that the bacterial metabolite caused 92% lysis of Microcystis aeruginosa cells, whereas the bacterial cells were responsible for approximately 91% reduction of MC-LR. The joint efforts of the bacterium and its metabolite accomplished the sustainable removal of algae and MC-LR. This is the first report of a single bacterial strain that achieves these dual actions.

Utilizing Photogrammetry and Strain Gage Measurement to Characterize Pressurization of an Inflatable Module

Science.gov (United States)

Valle, Gerard D.; Selig, Molly; Litteken, Doug; Oliveras, Ovidio

2012-01-01

This paper documents the integration of a large hatch penetration into an inflatable module. This paper also documents the comparison of analytical load predictions with measured results utilizing strain measurement. Strain was measured by utilizing photogrammetric measurement and through measurement obtained from strain gages mounted to selected clevises that interface with the structural webbings. Bench testing showed good correlation between strain measurement obtained from an extensometer and photogrammetric measurement especially after the fabric has transitioned through the low load/high strain region of the curve. Test results for the full-scale torus showed mixed results in the lower load and thus lower strain regions. Overall strain, and thus load, measured by strain gages and photogrammetry tracked fairly well with analytical predictions. Methods and areas of improvements are discussed.

Radioprotective effect of garlic extract on some bacterial strains with different radiation sensitivities

International Nuclear Information System (INIS)

Tawfik, Z.S.; Abushady, M.R.

1992-01-01

The radioprotective effect of garlic on four bacterial strains with different degrees of radiation sensitivities was investigated. The presence of garlic led to an increase in d-10 value of Ps. Aeruginosa, S. aureus and S. typhimurium by 160%, 50%, and 30% respectively. The protective efficiency of garlic against radiation was noticed to be proportional to its concentration in a given inoculum size. Garlic extract up to 180 micro liter per 10 8 inoculum size of B. cereus showed no protective effect. This fact was attributed to the existence of sulphur compounds in the given strain. Higher garlic concentrations appeared to affect the cloning efficiency of a given strain. 4fig., 2tab

The strains recommended for use in the bacterial reverse mutation test (OECD guideline 471) can be certified as non-genetically modified organisms.

Science.gov (United States)

Sugiyama, Kei-Ichi; Yamada, Masami; Awogi, Takumi; Hakura, Atsushi

2016-01-01

The bacterial reverse mutation test, commonly called Ames test, is used worldwide. In Japan, the genetically modified organisms (GMOs) are regulated under the Cartagena Domestic Law, and organisms obtained by self-cloning and/or natural occurrence would be exempted from the law case by case. The strains of Salmonella typhimurium and Escherichia coli recommended for use in the bacterial reverse mutation test (OECD guideline 471), have been considered as non-GMOs because they can be constructed by self-cloning or naturally occurring bacterial strains, or do not disturb the biological diversity. The present article explains the reasons why these tester strains should be classified as non-GMOs.

Proof of Principle for a Real-Time Pathogen Isolation Media Diagnostic: The Use of Laser-Induced Breakdown Spectroscopy to Discriminate Bacterial Pathogens and Antimicrobial-Resistant Staphylococcus aureus Strains Grown on Blood Agar

Directory of Open Access Journals (Sweden)

Rosalie A. Multari

2013-01-01

Full Text Available Laser-Induced Breakdown Spectroscopy (LIBS is a rapid, in situ, diagnostic technique in which light emissions from a laser plasma formed on the sample are used for analysis allowing automated analysis results to be available in seconds to minutes. This speed of analysis coupled with little or no sample preparation makes LIBS an attractive detection tool. In this study, it is demonstrated that LIBS can be utilized to discriminate both the bacterial species and strains of bacterial colonies grown on blood agar. A discrimination algorithm was created based on multivariate regression analysis of spectral data. The algorithm was deployed on a simulated LIBS instrument system to demonstrate discrimination capability using 6 species. Genetically altered Staphylococcus aureus strains grown on BA, including isogenic sets that differed only by the acquisition of mutations that increase fusidic acid or vancomycin resistance, were also discriminated. The algorithm successfully identified all thirteen cultures used in this study in a time period of 2 minutes. This work provides proof of principle for a LIBS instrumentation system that could be developed for the rapid discrimination of bacterial species and strains demonstrating relatively minor genomic alterations using data collected directly from pathogen isolation media.

Transforming microbial genotyping: a robotic pipeline for genotyping bacterial strains.

Directory of Open Access Journals (Sweden)

Brian O'Farrell

Full Text Available Microbial genotyping increasingly deals with large numbers of samples, and data are commonly evaluated by unstructured approaches, such as spread-sheets. The efficiency, reliability and throughput of genotyping would benefit from the automation of manual manipulations within the context of sophisticated data storage. We developed a medium- throughput genotyping pipeline for MultiLocus Sequence Typing (MLST of bacterial pathogens. This pipeline was implemented through a combination of four automated liquid handling systems, a Laboratory Information Management System (LIMS consisting of a variety of dedicated commercial operating systems and programs, including a Sample Management System, plus numerous Python scripts. All tubes and microwell racks were bar-coded and their locations and status were recorded in the LIMS. We also created a hierarchical set of items that could be used to represent bacterial species, their products and experiments. The LIMS allowed reliable, semi-automated, traceable bacterial genotyping from initial single colony isolation and sub-cultivation through DNA extraction and normalization to PCRs, sequencing and MLST sequence trace evaluation. We also describe robotic sequencing to facilitate cherrypicking of sequence dropouts. This pipeline is user-friendly, with a throughput of 96 strains within 10 working days at a total cost of 200,000 items were processed by two to three people. Our sophisticated automated pipeline can be implemented by a small microbiology group without extensive external support, and provides a general framework for semi-automated bacterial genotyping of large numbers of samples at low cost.

A nonluminescent and highly virulent Vibrio harveyi strain is associated with "bacterial white tail disease" of Litopenaeus vannamei shrimp.

Directory of Open Access Journals (Sweden)

Junfang Zhou

Full Text Available Recurrent outbreaks of a disease in pond-cultured juvenile and subadult Litopenaeus vannamei shrimp in several districts in China remain an important problem in recent years. The disease was characterized by "white tail" and generally accompanied by mass mortalities. Based on data from the microscopical analyses, PCR detection and 16S rRNA sequencing, a new Vibrio harveyi strain (designated as strain HLB0905 was identified as the etiologic pathogen. The bacterial isolation and challenge tests demonstrated that the HLB0905 strain was nonluminescent but highly virulent. It could cause mass mortality in affected shrimp during a short time period with a low dose of infection. Meanwhile, the histopathological and electron microscopical analysis both showed that the HLB0905 strain could cause severe fiber cell damages and striated muscle necrosis by accumulating in the tail muscle of L. vannamei shrimp, which led the affected shrimp to exhibit white or opaque lesions in the tail. The typical sign was closely similar to that caused by infectious myonecrosis (IMN, white tail disease (WTD or penaeid white tail disease (PWTD. To differentiate from such diseases as with a sign of "white tail" but of non-bacterial origin, the present disease was named as "bacterial white tail disease (BWTD". Present study revealed that, just like IMN and WTD, BWTD could also cause mass mortalities in pond-cultured shrimp. These results suggested that some bacterial strains are changing themselves from secondary to primary pathogens by enhancing their virulence in current shrimp aquaculture system.

Plant domestication and the assembly of bacterial and fungal communities associated with strains of the common sunflower, Helianthus annuus.

Science.gov (United States)

Leff, Jonathan W; Lynch, Ryan C; Kane, Nolan C; Fierer, Noah

2017-04-01

Root and rhizosphere microbial communities can affect plant health, but it remains undetermined how plant domestication may influence these bacterial and fungal communities. We grew 33 sunflower (Helianthus annuus) strains (n = 5) that varied in their extent of domestication and assessed rhizosphere and root endosphere bacterial and fungal communities. We also assessed fungal communities in the sunflower seeds to investigate the degree to which root and rhizosphere communities were influenced by vertical transmission of the microbiome through seeds. Neither root nor rhizosphere bacterial communities were affected by the extent of sunflower domestication, but domestication did affect the composition of rhizosphere fungal communities. In particular, more modern sunflower strains had lower relative abundances of putative fungal pathogens. Seed-associated fungal communities strongly differed across strains, but several lines of evidence suggest that there is minimal vertical transmission of fungi from seeds to the adult plants. Our results indicate that plant-associated fungal communities are more strongly influenced by host genetic factors and plant breeding than bacterial communities, a finding that could influence strategies for optimizing microbial communities to improve crop yields. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Distinct Bacterial Composition Associated with Different Laboratory-cultured Aiptasia Strains Across Two Thermal Conditions

KAUST Repository

Ahmed, Hanin

2018-01-01

laboratory model system to study the role of the coral microbiome. Analyses of the bacterial compositions associated with different Aiptasia strains across two temperatures (25 °C and 32 °C), based on 16S rRNA gene sequencing. This study aims also to identify

Bacterial utilization of size-fractionated dissolved organic matter

Digital Repository Service at National Institute of Oceanography (India)

Khodse, V.B.; Bhosle, N.B.

and vice versa (Amon et al. 2001, Goldberg et al. 2009). Similarly, utilization of uronic acid by heterotrophic bacteria has been reported in waters of the Bay of Bengal and the Gulf of Mexico (Hung et al. 2003, Khodse et al. 2007). In the coastal... in the Gulf of Mexico. Mar Chem 81:119-135 14 Jain A, Bhosle NB (2009) Biochemical composition of the marine conditioning film: implications for bacterial adhesion. Biofouling 25:13-19 Jorgensen NOG, Jensen RE (1994) Microbial fluxes of free...

Evaluation of various pesticides-degrading pure bacterial cultures ...

African Journals Online (AJOL)

Due to the intensive use of pesticides within the greenhouse-rose production, remediation of polluted soils has become a hot topic for researchers in recent decades. Several bacterial strains having the ability to utilize various pesticides as a sole source of carbon and energy were isolated from pesticidecontaminated soils ...

Bacterial strains diversity in Musa spp. phyllosphere with antifungal activity against Mycosphaerella fijiensis Morelet

Directory of Open Access Journals (Sweden)

Mileidy Cruz-Martín

2016-01-01

Full Text Available The search for alternatives to agricultural pesticides used for the management of black Sigatoka (Mycosphaerella fijiensis Morelet includes the selection of microorganisms strains with potential for the control of this pathogen. The objective of the work was to characterize bacterial strains isolated from the phylosphere of Musa spp. with antifungal effect against M. fijiensis. A morphological, cultural, physiological and molecular characterization of the strains was performed and the antifungal activity of these strains was quantified by dual culture. It was verified the diversity of bacteria with antifungal properties against M. fijiensis present in the phylosphere of Musa spp.  In addition, it was found that the phyllosphere of these crops can be used as a source of obtaining possible biological controls of M. fijiensis.   Keywords: bacteria, biocontrol, Black Sigatoka, epiphytes

RNA–Stable-Isotope Probing Shows Utilization of Carbon from Inulin by Specific Bacterial Populations in the Rat Large Bowel

Science.gov (United States)

Lawley, Blair; Munro, Karen; Sims, Ian M.; Lee, Julian; Butts, Christine A.; Roy, Nicole

2014-01-01

Knowledge of the trophisms that underpin bowel microbiota composition is required in order to understand its complex phylogeny and function. Stable-isotope (13C)-labeled inulin was added to the diet of rats on a single occasion in order to detect utilization of inulin-derived substrates by particular members of the cecal microbiota. Cecal digesta from Fibruline-inulin-fed rats was collected prior to (0 h) and at 6, 12, 18 and 24 h following provision of the [13C]inulin diet. RNA was extracted from these cecal specimens and fractionated in isopycnic buoyant density gradients in order to detect 13C-labeled nucleic acid originating in bacterial cells that had metabolized the labeled dietary constituent. RNA extracted from specimens collected after provision of the labeled diet was more dense than 0-h RNA. Sequencing of 16S rRNA genes amplified from cDNA obtained from these fractions showed that Bacteroides uniformis, Blautia glucerasea, Clostridium indolis, and Bifidobacterium animalis were the main users of the 13C-labeled substrate. Culture-based studies of strains of these bacterial species enabled trophisms associated with inulin and its hydrolysis products to be identified. B. uniformis utilized Fibruline-inulin for growth, whereas the other species used fructo-oligosaccharide and monosaccharides. Thus, RNA–stable-isotope probing (RNA-SIP) provided new information about the use of carbon from inulin in microbiota metabolism. PMID:24487527

A Nonluminescent and Highly Virulent Vibrio harveyi Strain Is Associated with “Bacterial White Tail Disease” of Litopenaeus vannamei Shrimp

Science.gov (United States)

Zhou, Junfang; Fang, Wenhong; Yang, Xianle; Zhou, Shuai; Hu, Linlin; Li, Xincang; Qi, Xinyong; Su, Hang; Xie, Layue

2012-01-01

Recurrent outbreaks of a disease in pond-cultured juvenile and subadult Litopenaeus vannamei shrimp in several districts in China remain an important problem in recent years. The disease was characterized by “white tail” and generally accompanied by mass mortalities. Based on data from the microscopical analyses, PCR detection and 16S rRNA sequencing, a new Vibrio harveyi strain (designated as strain HLB0905) was identified as the etiologic pathogen. The bacterial isolation and challenge tests demonstrated that the HLB0905 strain was nonluminescent but highly virulent. It could cause mass mortality in affected shrimp during a short time period with a low dose of infection. Meanwhile, the histopathological and electron microscopical analysis both showed that the HLB0905 strain could cause severe fiber cell damages and striated muscle necrosis by accumulating in the tail muscle of L. vannamei shrimp, which led the affected shrimp to exhibit white or opaque lesions in the tail. The typical sign was closely similar to that caused by infectious myonecrosis (IMN), white tail disease (WTD) or penaeid white tail disease (PWTD). To differentiate from such diseases as with a sign of “white tail” but of non-bacterial origin, the present disease was named as “bacterial white tail disease (BWTD)”. Present study revealed that, just like IMN and WTD, BWTD could also cause mass mortalities in pond-cultured shrimp. These results suggested that some bacterial strains are changing themselves from secondary to primary pathogens by enhancing their virulence in current shrimp aquaculture system. PMID:22383954

Characterization and degradation potential of diesel-degrading bacterial strains for application in bioremediation.

Science.gov (United States)

Balseiro-Romero, María; Gkorezis, Panagiotis; Kidd, Petra S; Van Hamme, Jonathan; Weyens, Nele; Monterroso, Carmen; Vangronsveld, Jaco

2017-10-03

Bioremediation of polluted soils is a promising technique with low environmental impact, which uses soil organisms to degrade soil contaminants. In this study, 19 bacterial strains isolated from a diesel-contaminated soil were screened for their diesel-degrading potential, biosurfactant (BS) production, and biofilm formation abilities, all desirable characteristics when selecting strains for re-inoculation into hydrocarbon-contaminated soils. Diesel-degradation rates were determined in vitro in minimal medium with diesel as the sole carbon source. The capacity to degrade diesel range organics (DROs) of strains SPG23 (Arthobacter sp.) and PF1 (Acinetobacter oleivorans) reached 17-26% of total DROs after 10 days, and 90% for strain GK2 (Acinetobacter calcoaceticus). The amount and rate of alkane degradation decreased significantly with increasing carbon number for strains SPG23 and PF1. Strain GK2, which produced BSs and biofilms, exhibited a greater extent, and faster rate of alkane degradation compared to SPG23 and PF1. Based on the outcomes of degradation experiments, in addition to BS production, biofilm formation capacities, and previous genome characterizations, strain GK2 is a promising candidate for microbial-assisted phytoremediation of diesel-contaminated soils. These results are of particular interest to select suitable strains for bioremediation, not only presenting high diesel-degradation rates, but also other characteristics which could improve rhizosphere colonization.

Biotransformation of Tributyltin chloride by Pseudomonas stutzeri strain DN2

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Dnyanada S. Khanolkar

2014-12-01

Full Text Available A bacterial isolate capable of utilizing tributyltin chloride (TBTCl as sole carbon source was isolated from estuarine sediments of west coast of India and identified as Pseudomonas stutzeri based on biochemical tests and Fatty acid methyl ester (FAME analysis. This isolate was designated as strain DN2. Although this bacterial isolate could resist up to 3 mM TBTCl level, it showed maximum growth at 2 mM TBTCl in mineral salt medium (MSM. Pseudomonas stutzeri DN2 exposed to 2 mM TBTCl revealed significant alteration in cell morphology as elongation and shrinkage in cell size along with roughness of cell surface. FTIR and NMR analysis of TBTCl degradation product extracted using chloroform and purified using column chromatography clearly revealed biotransformation of TBTCl into Dibutyltin dichloride (DBTCl2 through debutylation process. Therefore, Pseudomonas stutzeri strain DN2 may be used as a potential bacterial strain for bioremediation of TBTCl contaminated aquatic environmental sites.

Biotransformation of Tributyltin chloride by Pseudomonas stutzeri strain DN2

Science.gov (United States)

Khanolkar, Dnyanada S.; Naik, Milind Mohan; Dubey, Santosh Kumar

2014-01-01

A bacterial isolate capable of utilizing tributyltin chloride (TBTCl) as sole carbon source was isolated from estuarine sediments of west coast of India and identified as Pseudomonas stutzeri based on biochemical tests and Fatty acid methyl ester (FAME) analysis. This isolate was designated as strain DN2. Although this bacterial isolate could resist up to 3 mM TBTCl level, it showed maximum growth at 2 mM TBTCl in mineral salt medium (MSM). Pseudomonas stutzeri DN2 exposed to 2 mM TBTCl revealed significant alteration in cell morphology as elongation and shrinkage in cell size along with roughness of cell surface. FTIR and NMR analysis of TBTCl degradation product extracted using chloroform and purified using column chromatography clearly revealed biotransformation of TBTCl into Dibutyltin dichloride (DBTCl2) through debutylation process. Therefore, Pseudomonas stutzeri strain DN2 may be used as a potential bacterial strain for bioremediation of TBTCl contaminated aquatic environmental sites. PMID:25763027

40 CFR 180.123 - Inorganic bromide residues resulting from fumigation with methyl bromide; tolerances for residues.

Science.gov (United States)

2010-07-01

..., postharvest 30.0 Lemon, postharvest 30.0 Lime, postharvest 30.0 Mango, postharvest 20.0 Melon, honeydew... methyl bromide or from such fumigation in addition to the authorized use of methyl bromide on the source...

Analysis of preference for carbon source utilization among three strains of aromatic compounds degrading Pseudomonas.

Science.gov (United States)

Karishma, M; Trivedi, Vikas D; Choudhary, Alpa; Mhatre, Akanksha; Kambli, Pranita; Desai, Jinal; Phale, Prashant S

2015-10-01

Soil isolates Pseudomonas putida CSV86, Pseudomonas aeruginosa PP4 and Pseudomonas sp. C5pp degrade naphthalene, phthalate isomers and carbaryl, respectively. Strain CSV86 displayed a diauxic growth pattern on phenylpropanoid compounds (veratraldehyde, ferulic acid, vanillin or vanillic acid) plus glucose with a distinct second lag-phase. The glucose concentration in the medium remained constant with higher cell respiration rates on aromatics and maximum protocatechuate 3,4-dioxygenase activity in the first log-phase, which gradually decreased in the second log-phase with concomitant depletion of the glucose. In strains PP4 and C5pp, growth profile and metabolic studies suggest that glucose is utilized in the first log-phase with the repression of utilization of aromatics (phthalate or carbaryl). All three strains utilize benzoate via the catechol 'ortho' ring-cleavage pathway. On benzoate plus glucose, strain CSV86 showed preference for benzoate over glucose in contrast to strains PP4 and C5pp. Additionally, organic acids like succinate were preferred over aromatics in strains PP4 and C5pp, whereas strain CSV86 co-metabolizes them. Preferential utilization of aromatics over glucose and co-metabolism of organic acids and aromatics are found to be unique properties of P. putida CSV86 as compared with strains PP4 and C5pp and this property of strain CSV86 can be exploited for effective bioremediation. © FEMS 2015. All rights reserved.

Bromide in some coastal and oceanic waters of India

Digital Repository Service at National Institute of Oceanography (India)

DeSouza, F.P.; Dalal, V.N.K.

Bromide concentration and bromide/chlorinity ratio are estimated in coastal waters of Goa, Minicoy Lagoon, Western Arabian Sea and Western Bay of Bengal. The influence of precipitation and river runoff on bromide and bromide/chlorinity ratio...

Bacterial Prostatitis: Bacterial Virulence, Clinical Outcomes, and New Directions.

Science.gov (United States)

Krieger, John N; Thumbikat, Praveen

2016-02-01

Four prostatitis syndromes are recognized clinically: acute bacterial prostatitis, chronic bacterial prostatitis, chronic prostatitis/chronic pelvic pain syndrome, and asymptomatic prostatitis. Because Escherichia coli represents the most common cause of bacterial prostatitis, we investigated the importance of bacterial virulence factors and antimicrobial resistance in E. coli strains causing prostatitis and the potential association of these characteristics with clinical outcomes. A structured literature review revealed that we have limited understanding of the virulence-associated characteristics of E. coli causing acute prostatitis. Therefore, we completed a comprehensive microbiological and molecular investigation of a unique strain collection isolated from healthy young men. We also considered new data from an animal model system suggesting certain E. coli might prove important in the etiology of chronic prostatitis/chronic pelvic pain syndrome. Our human data suggest that E. coli needs multiple pathogenicity-associated traits to overcome anatomic and immune responses in healthy young men without urological risk factors. The phylogenetic background and accumulation of an exceptional repertoire of extraintestinal pathogenic virulence-associated genes indicate that these E. coli strains belong to a highly virulent subset of uropathogenic variants. In contrast, antibiotic resistance confers little added advantage to E. coli strains in these healthy outpatients. Our animal model data also suggest that certain pathogenic E. coli may be important in the etiology of chronic prostatitis/chronic pelvic pain syndrome through mechanisms that are dependent on the host genetic background and the virulence of the bacterial strain.

A novel cetyltrimethyl ammonium silver bromide complex and silver bromide nanoparticles obtained by the surfactant counterion.

Science.gov (United States)

Liu, Xian-Hao; Luo, Xiao-Hong; Lu, Shu-Xia; Zhang, Jing-Chang; Cao, Wei-Liang

2007-03-01

A novel cetyltrimethyl ammonium silver bromide (CTASB) complex has been prepared simply through the reaction of silver nitrate with cetyltrimethyl ammonium bromide (CTAB) in aqueous solution at room temperature by controlling the concentration of CTAB and the molar ratio of CTAB to silver nitrate in the reaction solution, in which halogen in CTAB is used as surfactant counterion. The structure and thermal behavior of cetyltrimethyl ammonium silver bromide have been investigated by using X-ray diffraction (XRD), infrared spectroscopy (IR), X-ray photoelectron spectroscopy (XPS), UV/vis spectroscopy, thermal analysis (TG-DTA), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The results show that the complex possesses a metastable layered structure. Upon heating the CTASB aqueous dispersion to above 80 degrees C, the structure change of the complex took place and CTAB-capped nanosized silver bromide particles further formed.

Recombinant protein expression in Pichia pastoris strains with an engineered methanol utilization pathway

Science.gov (United States)

2012-01-01

Βackground The methylotrophic yeast Pichia pastoris has become an important host organism for recombinant protein production and is able to use methanol as a sole carbon source. The methanol utilization pathway describes all the catalytic reactions, which happen during methanol metabolism. Despite the importance of certain key enzymes in this pathway, so far very little is known about possible effects of overexpressing either of these key enzymes on the overall energetic behavior, the productivity and the substrate uptake rate in P. pastoris strains. Results A fast and easy-to-do approach based on batch cultivations with methanol pulses was used to characterize different P. pastoris strains. A strain with MutS phenotype was found to be superior over a strain with Mut+ phenotype in both the volumetric productivity and the efficiency in expressing recombinant horseradish peroxidase C1A. Consequently, either of the enzymes dihydroxyacetone synthase, transketolase or formaldehyde dehydrogenase, which play key roles in the methanol utilization pathway, was co-overexpressed in MutS strains harboring either of the reporter enzymes horseradish peroxidase or Candida antarctica lipase B. Although the co-overexpression of these enzymes did not change the stoichiometric yields of the recombinant MutS strains, significant changes in the specific growth rate, the specific substrate uptake rate and the specific productivity were observed. Co-overexpression of dihydroxyacetone synthase yielded a 2- to 3-fold more efficient conversion of the substrate methanol into product, but also resulted in a reduced volumetric productivity. Co-overexpression of formaldehyde dehydrogenase resulted in a 2-fold more efficient conversion of the substrate into product and at least similar volumetric productivities compared to strains without an engineered methanol utilization pathway, and thus turned out to be a valuable strategy to improve recombinant protein production. Conclusions Co

Recombinant protein expression in Pichia pastoris strains with an engineered methanol utilization pathway

Directory of Open Access Journals (Sweden)

Krainer Florian W

2012-02-01

Full Text Available Abstract Βackground The methylotrophic yeast Pichia pastoris has become an important host organism for recombinant protein production and is able to use methanol as a sole carbon source. The methanol utilization pathway describes all the catalytic reactions, which happen during methanol metabolism. Despite the importance of certain key enzymes in this pathway, so far very little is known about possible effects of overexpressing either of these key enzymes on the overall energetic behavior, the productivity and the substrate uptake rate in P. pastoris strains. Results A fast and easy-to-do approach based on batch cultivations with methanol pulses was used to characterize different P. pastoris strains. A strain with MutS phenotype was found to be superior over a strain with Mut+ phenotype in both the volumetric productivity and the efficiency in expressing recombinant horseradish peroxidase C1A. Consequently, either of the enzymes dihydroxyacetone synthase, transketolase or formaldehyde dehydrogenase, which play key roles in the methanol utilization pathway, was co-overexpressed in MutS strains harboring either of the reporter enzymes horseradish peroxidase or Candida antarctica lipase B. Although the co-overexpression of these enzymes did not change the stoichiometric yields of the recombinant MutS strains, significant changes in the specific growth rate, the specific substrate uptake rate and the specific productivity were observed. Co-overexpression of dihydroxyacetone synthase yielded a 2- to 3-fold more efficient conversion of the substrate methanol into product, but also resulted in a reduced volumetric productivity. Co-overexpression of formaldehyde dehydrogenase resulted in a 2-fold more efficient conversion of the substrate into product and at least similar volumetric productivities compared to strains without an engineered methanol utilization pathway, and thus turned out to be a valuable strategy to improve recombinant protein

Radiolytic reduction reaction of colloidal silver bromide solution

International Nuclear Information System (INIS)

Oya, Yasuhisa; Zushi, Takehiro; Hasegawa, Kunihiko; Matsuura, Tatsuo.

1995-01-01

The reduction reaction of colloidal silver bromide (AgBr 3 ) 2- in nitrous oxide gas saturated solution of some alcohols: methanol, ethanol, 2-propanol and 2-methyl-2-propanol by γ-irradiation was studied spectrophotometrically in order to elucidate the mechanism of the formation of colloidal silver bromide (AgBr 3 ) 3- at ambient temperature. The amount of colloidal silver bromide formed increases in the order: i-PrOH, EtOH, MeOH. In t-BuOH, colloidal silver bromide did not form. The relative reactivities of alcohols for colloidal silver bromide was also studied kinetically. (author)

Effect of feeding tannin degrading bacterial culture (Streptococcus gallolyticus strain TDGB 406) on nutrient utilization, urinary purine derivatives and growth performance of goats fed on Quercus semicarpifolia leaves.

Science.gov (United States)

Kumar, K; Chaudhary, L C; Agarwal, N; Kamra, D N

2014-10-01

To study the effect of supplementation of tannin degrading bacterial culture (Streptococcus gallolyticus strain TDGB 406) on growth performance, nutrient utilization and urinary purine derivatives of goats fed on oak (Quercus semicarpifolia) leaves. For growth study, eighteen billy goats (4 month old, average body weight 9.50 ± 1.50 kg) were distributed into three groups of six animals each. The animals of group 1 served as control while animals of groups 2 (T1) and 3 (T2) were given (@ 5 ml/kg live weight) autoclaved and live culture of isolate TDGB 406 (10(6) cells/ml) respectively. The animals were fed measured quantity of dry oak leaves as the main roughage source and ad libitum maize hay along with fixed quantity of concentrate mixture. The feeding of live culture of isolate TDGB 406 (probiotic) did not affect dry matter intake and digestibility of nutrients except that of dry matter and crude protein, which was higher in T2 group as compared to control. All the animals were in positive nitrogen balance. There was no significant effect of feeding isolate TDGB 406 on urinary purine derivatives (microbial protein production) in goats. The body weight gain and average live weight gain was significantly higher (p = 0.071) in T2 group as compared to control. Feed conversion efficiency was also better in the goats fed on live culture of TDGB 406 (T2). The feeding of tannin degrading bacterial isolate TDGB 406 as probiotic resulted in improved growth performance and feed conversion ratio in goats fed on oak leaves as one of the main roughage source. Journal of Animal Physiology and Animal Nutrition © 2013 Blackwell Verlag GmbH.

‘Olegusella massiliensis’ strain KHD7, a new bacterial genus isolated from the female genital tract

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K. Diop

2016-07-01

Full Text Available We report the main characteristics of ‘Olegusella massiliensis’ gen. nov., sp. nov., strain KHD7 (= CSUR P2268=DSM 101849, a new member of the Coriobacteriaceae family isolated from the vaginal flora of a patient with bacterial vaginosis.

The efficacy of different anti-microbial metals at preventing the formation of, and eradicating bacterial biofilms of pathogenic indicator strains.

Science.gov (United States)

Gugala, Natalie; Lemire, Joe A; Turner, Raymond J

2017-06-01

The emergence of multidrug-resistant pathogens and the prevalence of biofilm-related infections have generated a demand for alternative anti-microbial therapies. Metals have not been explored in adequate detail for their capacity to combat infectious disease. Metal compounds can now be found in textiles, medical devices and disinfectants-yet, we know little about their efficacy against specific pathogens. To help fill this knowledge gap, we report on the anti-microbial and antibiofilm activity of seven metals: silver, copper, titanium, gallium, nickel, aluminum and zinc against three bacterial strains, Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli. To evaluate the capacity of metal ions to prevent the growth of, and eradicate biofilms and planktonic cells, bacterial cultures were inoculated in the Calgary Biofilm Device (minimal biofilm eradication concentration) in the presence of the metal salts. Copper, gallium and titanium were capable of preventing planktonic and biofilm growth, and eradicating established biofilms of all tested strains. Further, we observed that the efficacies of the other tested metal salts displayed variable efficacy against the tested strains. Further, contrary to the enhanced resistance anticipated from bacterial biofilms, particular metal salts were observed to be more effective against biofilm communities versus planktonic cells. In this study, we have demonstrated that the identity of the bacterial strain must be considered before treatment with a particular metal ion. Consequent to the use of metal ions as anti-microbial agents to fight multidrug-resistant and biofilm-related infections increases, we must aim for more selective deployment in a given infectious setting.

Strains of bacterial species induce a greatly varied acute adaptive immune response: The contribution of the accessory genome.

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Uri Sela

2018-01-01

Full Text Available A fundamental question in human susceptibility to bacterial infections is to what extent variability is a function of differences in the pathogen species or in individual humans. To focus on the pathogen species, we compared in the same individual the human adaptive T and B cell immune response to multiple strains of two major human pathogens, Staphylococcus aureus and Streptococcus pyogenes. We found wide variability in the acute adaptive immune response induced by various strains of a species, with a unique combination of activation within the two arms of the adaptive response. Further, this was also accompanied by a dramatic difference in the intensity of the specific protective T helper (Th response. Importantly, the same immune response differences induced by the individual strains were maintained across multiple healthy human donors. A comparison of isogenic phage KO strains, demonstrated that of the pangenome, prophages were the major contributor to inter-strain immune heterogeneity, as the T cell response to the remaining "core genome" was noticeably blunted. Therefore, these findings extend and modify the notion of an adaptive response to a pathogenic bacterium, by implying that the adaptive immune response signature of a bacterial species should be defined either per strain or alternatively to the species' 'core genome', common to all of its strains. Further, our results demonstrate that the acquired immune response variation is as wide among different strains within a single pathogenic species as it is among different humans, and therefore may explain in part the clinical heterogeneity observed in patients infected with the same species.

In vitro antibacterial activity of methanol and water extracts of adiantum capillus veneris and tagetes patula against multidrug resistant bacterial strains

International Nuclear Information System (INIS)

Hussain, M.M.; Ahmad, B.; Bashid, E.; Hashim, S.

2014-01-01

The aim of present study was to screen the antimicrobial activities of extracts of leaves and stems of Adiantum capillus veneris and Tagetes patula against multidrug-resistant (MDR) bacterial strains. Extracts from the leaves and stems of these plants were extracted with methanol and water and tested for their antibacterial activity by disc diffusion method against ten MDR bacterial strains i.e., Citrobacter freundii, Escherichia coli, Providencia, Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumoniae, Proteus vulgaris, Salmonella typhi, Shigella and Vibrio cholerae. Leaves methanol extract (LME) of Adiantum showed maximum Zone of Inhibition (ZI) against Providencia, Klebsiella pneumoniae, Shigella, Vibrio cholerae, Staphylococcus aureus, Proteus vulgaris and Salmonella typhi, whereas its stem methanol extract (SME) was very active against Escherichia coli, Klebsiella pneumoniae and Salmonella typhi. Similarly LME of Tagetes showed highest ZI against Escherichia coli and Vibrio cholerae while SME showed highest ZI to Escherichia coli, Vibrio cholerae, Providencia, Shigella and Klebsiella pneumoniae. Leaves water extract (LWE) of Adiantum was very active against all ten bacterial strains while its stem water extract (SWE) showed maximum ZI against Escherichia coli, Klebsiella pneumoniae and Salmonella typhi, Shigella, Proteus vulgaris and Providencia. LWE of Tagetes was only active against Vibrio cholerae whereas SWE was very active against Salmonella typhi and active against P. vulgaris, Citrobacter freundii and Vibrio cholerae. It was concluded from this study that extracts of both Adiantum and Tagetes have prominent activities against most of the MDR bacterial strains and needs further studies for utmost benefits. (author)

Binding of collagens to an enterotoxigenic strain of Escherichia coli

International Nuclear Information System (INIS)

Visai, L.; Speziale, P.; Bozzini, S.

1990-01-01

An enterotoxigenic strain of Escherichia coli, B34289c, has been shown to bind the N-terminal region of fibronectin with high affinity. We now report that this strain also binds collagen. The binding of 125I-labeled type II collagen to bacteria was time dependent and reversible. Bacteria expressed a limited number of collagen receptors (2.2 x 10(4) per cell) and bound collagen with a Kd of 20 nM. All collagen types tested (I to V) as well as all tested cyanogen bromide-generated peptides [alpha 1(I)CB2, alpha 1(I)CB3, alpha 1(I)CB7, alpha 1(I)CB8, and alpha 2(I)CB4] were recognized by bacterial receptors, as demonstrated by the ability of these proteins to inhibit the binding of 125I-labeled collagen to bacteria. Of several unlabeled proteins tested in competition experiments, fibronectin and its N-terminal region strongly inhibited binding of the radiolabeled collagen to E. coli cells. Conversely, collagen competed with an 125I-labeled 28-kilodalton fibronectin fragment for bacterial binding. Collagen bound to bacteria could be displaced by excess amounts of either unlabeled fibronectin or its N-terminal fragment. Similarly, collagen could displace 125I-labeled N-terminal peptide of fibronectin bound to the bacterial cell surface. Bacteria grown at 41 degrees C or in the presence of glucose did not express collagen or fibronectin receptors. These results indicate the presence of specific binding sites for collagen on the surface of E. coli cells and furthermore that the collagen and fibronectin binding sites are located in close proximity, possibly on the same structure

Screening of bacterial strains for pectinolytic activity: characterization of the polygalacturonase produced by Bacillus sp

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Soares Márcia M.C.N.

1999-01-01

Full Text Available One hundred sixty eight bacterial strains, isolated from soil and samples of vegetable in decomposition, were screened for the use of citrus pectin as the sole carbon source. 102 were positive for pectinase depolymerization in assay plates as evidenced by clear hydrolization halos. Among them, 30% presented considerable pectinolytic activity. The cultivation of these strains by submerged and semi-solid fermentation for polygalacturonase production indicated that five strains of Bacillus sp produced high quantities of the enzyme. The physico-chemical characteristics, such as optimum pH of 6.0 - 7.0, optimum temperatures between 45oC and 55oC, stability at temperatures above 40oC and in neutral and alkaline pH, were determined.

Extracellular polymeric substances (EPS) producing bacterial strains of municipal wastewater sludge: isolation, molecular identification, EPS characterization and performance for sludge settling and dewatering.

Science.gov (United States)

Bala Subramanian, S; Yan, S; Tyagi, R D; Surampalli, R Y

2010-04-01

Wastewater treatment plants often face the problems of sludge settling mainly due to sludge bulking. Generally, synthetic organic polymer and/or inorganic coagulants (ferric chloride, alum and quick lime) are used for sludge settling. These chemicals are very expensive and further pollute the environment. Whereas, the bioflocculants are environment friendly and may be used to flocculate the sludge. Extracellular polymeric substances (EPS) produced by sludge microorganisms play a definite role in sludge flocculation. In this study, 25 EPS producing strains were isolated from municipal wastewater treatment plant. Microorganisms were selected based on EPS production properties on solid agar medium. Three types of EPS (slime, capsular and bacterial broth mixture of both slime and capsular) were harvested and their characteristics were studied. EPS concentration (dry weight), viscosity and their charge (using a Zetaphoremeter) were also measured. Bioflocculability of obtained EPS was evaluated by measuring the kaolin clay flocculation activity. Six bacterial strains (BS2, BS8, BS9, BS11, BS15 and BS25) were selected based on the kaolin clay flocculation. The slime EPS was better for bioflocculation than capsular EPS and bacterial broth. Therefore, extracted slime EPS (partially purified) from six bacterial strains was studied in terms of sludge settling [sludge volume index (SVI)] and dewatering [capillary suction time (CST)]. Biopolymers produced by individual strains substantially improved dewaterability. The extracted slime EPS from six different strains were partially characterized. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Acute effect of methyl bromide on sleep-wakefulness and its

Energy Technology Data Exchange (ETDEWEB)

Tanaka, S; Arito, H; Abuku, S; Imamiya, S

1986-01-01

In an attempt to clarify the acute effects of methyl bromide on the central nervous system, abnormal electrocorticographic activity and changes in sleep-wakefulness and its circadian rhythms were investigated after a single injection of methyl bromide. The effects of possible hydrolyzed products of methyl bromide, methanol and bromine ions on sleep and its rhythms were also examined. It was found that the hydrolyzed products of methyl bromide, bromine ions and methanol exerted little effect on the amounts of wakefulness (W), non-REM sleep (NREMS) and REM sleep (REMS) at the same molar dose as 45 mg methyl bromide/kg. Thus, it can be concluded that the methyl bromide-induced changes in sleep-wakefulness and its circadian rhythms are due to methyl bromide and not to the hydrolyzed products. It was also found that amounts of W, NREMS and REMS were changed dose-dependently after a single injection of methyl bromide and that methyl bromide significantly disrupted the circadian REMS rhythm. 17 references, 1 figure, 1 table.

Biodegradation of Chlorpyrifos by Pseudomonas Resinovarans Strain AST2.2 Isolated from Enriched Cultures.

OpenAIRE

Anish Sharma*,; Jyotsana Pandit; Ruchika Sharma and; Poonam Shirkot

2016-01-01

A bacterial strain AST2.2 with chlorpyrifos degrading ability was isolated by enrichment technique from apple orchard soil with previous history of chlorpyrifos use. Based on the morphological, biochemical tests and 16S rRNA sequence analysis, AST2.2 strain was identified as Pseudomonas resinovarans. The strain AST2.2 utilized chlorpyrifos as the sole source of carbon and energy. This strain exhibited growth upto 400mg/l concentration of chlorpyrifos and exhibited high extracellular organopho...

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

DEFF Research Database (Denmark)

Pedersen, Annette; Nybroe, Ole; Winding, Anne

2009-01-01

How bacterial feeding fauna affects colonization and survival of bacteria in soil is not well understood, which constrains the applicability of bacterial inoculants in agriculture. This study aimed to unravel how food quality of bacteria and bacterial feeders with different feeding habits (the......50090 or one of two biocontrol strains P. fluorescens CHA0 or Pseudomonas sp. DSS73) or combinations of two bacterial strains. DSM50090 is a suitable food bacterium, DSS73 is of intermediate food quality, and CHA0 is inedible to the bacterial feeders. Bacterial and protozoan cell numbers were measured...... predation pressure. Hence, the results suggested that the outcome of competition among bacteria depended on their ability to cope with the prevailing bacterial predator....

Utilizing Photogrammetry and Strain Gage Measurement to Characterize Pressurization of Inflatable Modules

Science.gov (United States)

Mohammed, Anil

2011-01-01

This paper focuses on integrating a large hatch penetration into inflatable modules of various constructions. This paper also compares load predictions with test measurements. The strain was measured by utilizing photogrammetric methods and strain gages mounted to select clevises that interface with the structural webbings. Bench testing showed good correlation between strain data collected from an extensometer and photogrammetric measurements, even when the material transitioned from the low load to high load strain region of the curve. The full-scale torus design module showed mixed results as well in the lower load and high strain regions. After thorough analysis of photogrammetric measurements, strain gage measurements, and predicted load, the photogrammetric measurements seem to be off by a factor of two.

Expert Opinion on Three Phage Therapy Related Topics: Bacterial Phage Resistance, Phage Training and Prophages in Bacterial Production Strains

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Christine Rohde

2018-04-01

Full Text Available Phage therapy is increasingly put forward as a “new” potential tool in the fight against antibiotic resistant infections. During the “Centennial Celebration of Bacteriophage Research” conference in Tbilisi, Georgia on 26–29 June 2017, an international group of phage researchers committed to elaborate an expert opinion on three contentious phage therapy related issues that are hampering clinical progress in the field of phage therapy. This paper explores and discusses bacterial phage resistance, phage training and the presence of prophages in bacterial production strains while reviewing relevant research findings and experiences. Our purpose is to inform phage therapy stakeholders such as policy makers, officials of the competent authorities for medicines, phage researchers and phage producers, and members of the pharmaceutical industry. This brief also points out potential avenues for future phage therapy research and development as it specifically addresses those overarching questions that currently call for attention whenever phages go into purification processes for application.

Studies on chlorinated bromide salt for microfouling control

International Nuclear Information System (INIS)

Satpathy, K.K.; Rajmohan, R.; Rao, T.S.; Nair, K.V.K.; Mathur, P.K.

1995-01-01

The Fast Breeder Test reactor (FBTR) at Kalpakkam has been facing various problems in cooling water systems in spite of intermittent chlorination.Effects of chlorinated-bromide mixture was evaluated against heterotrophic bacteria (TVC) and iron oxidising bacteria (IOB) vis-a-vis chlorine. Results indicated that chlorinated-bromide mixture was far superior (2 orders of magnitude for TVC and 2 times for IOB) to chlorine in microfouling control. Results also showed that at bromide to chlorine ratio of one effectiveness of chlorinated-bromide was at its maximum. (author). 9 refs., 1 tab

Development of a strain of saccharomyces cereviase to utilize hemicellulosic biomass

International Nuclear Information System (INIS)

Batt, C.A.

1991-01-01

The current status of yeast conversion to utilize pentose sugar is discussed in this paper. The development of processes for the production of ethanol from agricultural wastes provides both a beneficial utilization of the resources presently available and an alternate source of liquid transportation fuel. The efficient conversion of agricultural bio mass is in part dependent on utilization of all the potential sugars, including the pentoses in the hemicellulosic fraction. A number of approaches have been investigated, including the engineering of strain of S. cerevisiae which express a xylose isomerase activity. Despite the apparent lack of success with respect to expressing an active xylose isomerase, a great deal of knowledge has been gained on the metabolism of pentoses by yeast and the genetics, structure/function of the enzyme xylose isomerase. Hopefully this cumulative knowledge base will lead to the design of a xylose isomerase with the appropriate structure to allow it retain activity in S. cerevisiae. This coupled with the elegant efforts in a number of laboratories to develop cellulose utilizing strains of S. cerevisiae might yield a single yeast capable of fermenting all of the major carbon substrates in agricultural to fuel grade ethanol. (Orig./A.B.)

Aerobic cyanide degradation by bacterial isolates from cassava factory wastewater.

Science.gov (United States)

Kandasamy, Sujatha; Dananjeyan, Balachandar; Krishnamurthy, Kumar; Benckiser, Gero

2015-01-01

Ten bacterial strains that utilize cyanide (CN) as a nitrogen source were isolated from cassava factory wastewater after enrichment in a liquid media containing sodium cyanide (1 mM) and glucose (0.2% w/v). The strains could tolerate and grow in cyanide concentrations of up to 5 mM. Increased cyanide levels in the media caused an extension of lag phase in the bacterial growth indicating that they need some period of acclimatisation. The rate of cyanide removal by the strains depends on the initial cyanide and glucose concentrations. When initial cyanide and glucose concentrations were increased up to 5 mM, cyanide removal rate increased up to 63 and 61 per cent by Bacillus pumilus and Pseudomonas putida. Metabolic products such as ammonia and formate were detected in culture supernatants, suggesting a direct hydrolytic pathway without an intermediate formamide. The study clearly demonstrates the potential of aerobic treatment with cyanide degrading bacteria for cyanide removal in cassava factory wastewaters.

Biodegradation of Maya crude oil fractions by bacterial strains and a defined mixed culture isolated from Cyperus laxus rhizosphere soil in a contaminated site

Energy Technology Data Exchange (ETDEWEB)

Diaz-Ramirez, I. J.; Gutierrez-Rojas, M.; Favela-Torres, E. [Autonomous Metropolitan University (UAM)- Iztapalapa, Dept. of Biotechnology, Federal District (Mexico); Ramirez-Sada, H. [Autonomous Metropolitan University (UAM)-Xochimilco, Dept. of Biological Systems, Federal District (Mexico)

2003-12-01

Biodegradation of aliphatic, aromatic, and polar constituents of Maya crude oil by a set of isolated bacterial strains and a defined mixed culture made up with all isolated strains, was evaluated. The bacterial strains were obtained from the rhizosphere of Cyperus laxus, a native plant on a highly hydrocarbon-polluted site. Oxygen uptake rate was used to determine the culture transfer timing during the enrichment culture. Results showed that five of the isolated strains were able to degrade 50 per cent of the aliphatic fractions of Maya crude oil. With the defined mixed culture the level of biodegradation was 47 per cent for aliphatics and 6 per cent of the aromatic-polar mixture. When grown in the presence of total hydrocarbons, the defined mixed culture was able to degrade 40 per cent of the aliphatic fraction and 26 per cent of the aromatic fraction. By combining enrichment cultures with oxygen uptake rate to determine the culture transfer timing during the enrichment cultures allowed the isolation of bacterial strains that are able to degrade specific hydrocarbon fractions at high consumption rates. 28 refs., 4 tabs., 1 fig.

Bacterial Biosensors for Measuring Availability of Environmental Pollutants

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Jan Roelof van der Meer

2008-07-01

Full Text Available Traditionally, pollution risk assessment is based on the measurement of a pollutant’s total concentration in a sample. The toxicity of a given pollutant in the environment, however, is tightly linked to its bioavailability, which may differ significantly from the total amount. Physico-chemical and biological parameters strongly influence pollutant fate in terms of leaching, sequestration and biodegradation. Bacterial sensorreporters, which consist of living micro-organisms genetically engineered to produce specific output in response to target chemicals, offer an interesting alternative to monitoring approaches. Bacterial sensor-reporters detect bioavailable and/or bioaccessible compound fractions in samples. Currently, a variety of environmental pollutants can be targeted by specific biosensor-reporters. Although most of such strains are still confined to the lab, several recent reports have demonstrated utility of bacterial sensing-reporting in the field, with method detection limits in the nanomolar range. This review illustrates the general design principles for bacterial sensor-reporters, presents an overview of the existing biosensor-reporter strains with emphasis on organic compound detection. A specific focus throughout is on the concepts of bioavailability and bioaccessibility, and how bacteria-based sensing-reporting systems can help to improve our basic understanding of the different processes at work.

Improved xylose and arabinose utilization by an industrial recombinant Saccharomyces cerevisiae strain using evolutionary engineering

DEFF Research Database (Denmark)

Sanchez, R.G.; Karhumaa, Kaisa; Fonseca, C.

2010-01-01

Background: Cost-effective fermentation of lignocellulosic hydrolysate to ethanol by Saccharomyces cerevisiae requires efficient mixed sugar utilization. Notably, the rate and yield of xylose and arabinose co-fermentation to ethanol must be enhanced. Results: Evolutionary engineering was used...... to improve the simultaneous conversion of xylose and arabinose to ethanol in a recombinant industrial Saccharomyces cerevisiae strain carrying the heterologous genes for xylose and arabinose utilization pathways integrated in the genome. The evolved strain TMB3130 displayed an increased consumption rate...... of our knowledge, this is the first report that characterizes the molecular mechanisms for improved mixed-pentose utilization obtained by evolutionary engineering of a recombinant S. cerevisiae strain. Increased transport of pentoses and increased activities of xylose converting enzymes contributed...

Polyphasic analysis of Acidovorax citrulli strains from northeastern Brazil

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Kirley Michele Marques Silva

2016-06-01

Full Text Available ABSTRACT Bacterial fruit blotch (BFB of cucurbit plants is caused by Acidovorax citrulli and represents a serious concern to melon (Cucumis melo L. growers worldwide, including those in Brazil. Thirty-four A. citrulli strains from different melon production areas of northeastern Brazil were characterized for their virulence on melon fruits and their substrate utilization and molecular profiles. Based on the analysis of BFB severity on melon fruits, the A. citrulli strains were divided into three groups, classified as mildly, moderately or highly virulent. Although host-related groups were not observed, the watermelon and ‘melão-pepino’ strains exhibited only low or moderate virulence on melon fruit. Substrate utilization profiles revealed that 94 % of the 95 tested compounds were used by A. citrulli strains as a carbon source. Overall, based on substrate utilization, low variability was observed with no relationship to host of origin. The formation of one group of A. citrulli strains based on Repetitive Sequence-based PCR (rep-PCR analysis confirmed the low variability observed in the substrate utilization analyses. Bayesian inference based on the analysis of 23S rDNA partial sequence data resulted in one well-supported clade and clustered the strains with the A. citrulli-type species with high posterior probability support. Based on the markers used, the Brazilian A. citrulli strains belong to a single group, which corresponds to the previously described Group I for this bacterium in the United States.

Advanced hydrogen electrode for hydrogen-bromide battery

Science.gov (United States)

Kosek, Jack A.; Laconti, Anthony B.

1987-01-01

Binary platinum alloys are being developed as hydrogen electrocatalysts for use in a hydrogen bromide battery system. These alloys were varied in terms of alloy component mole ratio and heat treatment temperature. Electrocatalyst evaluation, performed in the absence and presence of bromide ion, includes floating half cell polarization studies, electrochemical surface area measurements, X ray diffraction analysis, scanning electron microscopy analysis and corrosion measurements. Results obtained to date indicate a platinum rich alloy has the best tolerance to bromide ion poisoning.

BACTERIAL CONSORTIUM

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Payel Sarkar

2013-01-01

Full Text Available Petroleum aromatic hydrocarbons like benzen e, toluene, ethyl benzene and xylene, together known as BTEX, has almost the same chemical structure. These aromatic hydrocarbons are released as pollutants in th e environment. This work was taken up to develop a solvent tolerant bacterial cons ortium that could degrade BTEX compounds as they all share a common chemical structure. We have isolated almost 60 different types of bacterial strains from different petroleum contaminated sites. Of these 60 bacterial strains almost 20 microorganisms were screene d on the basis of capability to tolerate high concentration of BTEX. Ten differe nt consortia were prepared and the compatibility of the bacterial strains within the consortia was checked by gram staining and BTEX tolerance level. Four successful mi crobial consortia were selected in which all the bacterial strains concomitantly grew in presence of high concentration of BTEX (10% of toluene, 10% of benzene 5% ethyl benzene and 1% xylene. Consortium #2 showed the highest growth rate in pr esence of BTEX. Degradation of BTEX by consortium #2 was monitored for 5 days by gradual decrease in the volume of the solvents. The maximum reduction observed wa s 85% in 5 days. Gas chromatography results also reveal that could completely degrade benzene and ethyl benzene within 48 hours. Almost 90% degradation of toluene and xylene in 48 hours was exhibited by consortium #2. It could also tolerate and degrade many industrial solvents such as chloroform, DMSO, acetonitrile having a wide range of log P values (0.03–3.1. Degradation of aromatic hydrocarbon like BTEX by a solvent tolerant bacterial consortium is greatly significant as it could degrade high concentration of pollutants compared to a bacterium and also reduces the time span of degradation.

Identification of marine methanol-utilizing bacteria

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, M; Iwaki, H; Kouno, K; Inui, T

1980-01-01

A taxonomical study of 65 marine methanol-utilizing bacteria is described. They were Gram-negative, non-spore-forming rods with a polar flagellum and had marine bacterial properties and required vitamin B/sub 12/ for growth. All of them assimilated fructose in addition to C/sub 1/-compounds and produced acid oxidatively from fructose. Twenty-four strains assimilated only C/sub 1/-compounds. They were resistant to penicillin, oxytetracycline and 0/129 substance (Vibrio stat), and tolerant to 12% NaCl. Guanine-cytosine contents of deoxyribonucleic acid in typical strains fell in the range of 43.8 to 47.6%. Other morphological and physiological properties were almost the same as those of terrestrial methanol-utilizers. Bacteria in the first group (41 strains) were facultative methylotrophs and were divided into three subgroups by the assimilation of methylated amines, that is, subgroup I (30 strains) assimilated mono-, di- and tri-methylamine, subgroup II (9 strains) assimilated only mono-methylamine, the bacteria of subgroups I and II were named Alteromonas thalassomethanolica sp. nov. and subgroup III (2 strains) did not assimilate methylated amines, and was tentatively assigned as Alteromonas sp. The second group of bacteria (24 strains) was obligate methylotrophs, named Methylomonas thalassica sp. nov. and was divided into subgroup IV (15 strains) which assimilated mono-, di and tri-methylamine and subgroup V (9 strains) which assimilated mono-methylamine.

Construction of a stable GFP-tagged Vibrio harveyi strain for bacterial dynamics analysis of abalone infection.

Science.gov (United States)

Travers, Marie-Agnès; Barbou, Annaïck; Le Goïc, Nelly; Huchette, Sylvain; Paillard, Christine; Koken, Marcel

2008-12-01

Vibrio harveyi is a bacterial marine pathogen that can cause fatal disease in a large range of vertebrates and invertebrates, including the commercially important marine gastropod, Haliotis tuberculata. Since 1997, strains of this bacterium have regularly been causing high mortalities in farmed and wild abalone populations. The way in which the pathogen enters into abalone and the disease transmission mechanisms are thus far unknown. Therefore, a pathogenic strain, ORM4, was green fluorescent protein-tagged and validated both for its growth characteristics and for its virulence as a genuine model for abalone disease. The strain allows V. harveyi quantification by flow cytometry in seawater and in abalone haemolymph as well as the in situ detection of the parasite inside abalone tissues.

Enterobacter sp. LU1 as a novel succinic acid producer - co-utilization of glycerol and lactose.

Science.gov (United States)

Podleśny, Marcin; Jarocki, Piotr; Wyrostek, Jakub; Czernecki, Tomasz; Kucharska, Jagoda; Nowak, Anna; Targoński, Zdzisław

2017-03-01

Succinic acid is an important C4-building chemical platform for many applications. A novel succinic acid-producing bacterial strain was isolated from goat rumen. Phylogenetic analysis based on the 16S rRNA sequence and physiological analysis indicated that the strain belongs to the genus Enterobacter. This is the first report of a wild bacterial strain from the genus Enterobacter that is capable of efficient succinic acid production. Co-fermentation of glycerol and lactose significantly improved glycerol utilization under anaerobic conditions, debottlenecking the utilization pathway of this valuable biodiesel waste product. Succinic acid production reached 35 g l -1 when Enterobacter sp. LU1 was cultured in medium containing 50 g l -1 of glycerol and 25 g l -1 of lactose as carbon sources. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Anti-bacterial Efficacy of Bacteriocin Produced by Marine Bacillus subtilis Against Clinically Important Extended Spectrum Beta-Lactamase Strains and Methicillin-Resistant Staphylococcus aureus

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Suresh Mickymaray

2018-02-01

Full Text Available Objective: To investigate the anti-bacterial efficacy of bacteriocin produced by Bacillus subtilis SM01 (GenBank accession no: KY612347, a Gram-positive marine bacterium, against Extended Spectrum Beta-Lactamase (ESBL producing Gram-negative pathogens Acinetobacter baumannii, Pseudomonas aeruginosa, and Escherichia coli, and Gram-positive pathogen Methicillin-Resistant Staphylococcus aureus (MRSA. Methods: A marine bacterium was isolated from mangrove sediment from the Red Sea coast of Jeddah, Kingdom of Saudi Arabia, and identified based on its morphological, biochemical, and molecular characteristics. The bacteriocin production using this isolate was carried out in brain heart infusion broth (BHIB medium. The Anti-bacterial activity of bacteriocin was evaluated against selected ESBL strains and MRSA by the well agar method. The effects of incubation time, pH, and temperature on the Anti-bacterial activity were studied. Results: The bacteriocin Bac-SM01 produced by B. subtilis SM01 demonstrated broad-spectrum Anti-bacterial activity against both Gram-negative and -positive bacteria. The present study is the first report that the bacteriocin Bac-SM01 inhibits the growth of ESBL producing Gram-negative strains A. baumannii, P. aeruginosa, and E. coli, and a Gram-positive MRSA strain. The optimum incubation time, pH, and temperature for the Anti-bacterial activity of Bac-SM01 was 24 h, 7, and 37°C respectively. Conclusion: The overall investigation can conclude that the bacteriocin Bac-SM01 from the marine isolate Bacillus subtilis SM01 could be used as an alternative Anti-bacterial agent in pharmaceutical products.

The importance of bacterial utilization of released phytoplankton photosynthate in two humic forest lakes in southern Finland

International Nuclear Information System (INIS)

Jones, R.I.; Salonen, K.

1985-01-01

Bacterial utilization of photosynthetically fixed dissolved organic carbon (PDOC) released from natural phytoplankton assemblages was studied in two small, extremely humic, forest lakes in southern Finland. Bacterial activity (measured us uptake of 14 C-glucose) and phytoplankton photosynthesis (measured as light uptake of 14 CO 2 ) could be most effectively separated using Nuclepore filters of pore 1-2 μm. Released PDOC was 10-67% of total phytoplankton carbon fixation during in situ experiments, and represented about 0.1% of total DOC. Net uptake of PDOC by bacteria was found to be about 20% during 24 hour laboratory incubations, although about 40% of PDOC present at the start of an experiment could be utilized by bacteria during a 24 hour period. PDOC does not provide a quantitatively important substrate supply fo bacterial respiration in humic forest lakes. (author)

Cooked meat products made of coarsely ground pork: the main bacterial strains of bacterial flora, their heat resistance and effect on spoilage

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Esko Petäjä

1993-09-01

Full Text Available This study was conducted to investigate the bacterial flora of the surface layer and the core of meat products made of coarsely ground pork at the moment of spoilage when stored at 7°C or 4°C. The dominating strains were isolated, their heat resistance was studied in APT-broth, on APT-agar and in coarsely ground cured pork, and their growth after heating and effect on spoilage were followed in coarsely ground cured pork. The first signs of spoilage appeared in the surface layer of the products. The strains were coccoid lactic acid bacteria with counts ranging from 3,5 to 7.8 log cfu (colony forming units/g. They survived only accidentally after heating for 15 minutes at 72°C in APT-broth. The core of the products contained only coccoid lactic acid bacteria or only pseudomonads or both as the main bacterial strains. The counts ranged from 2.6 to 6.0 log cfu/g. Most of the strains isolated from the core survived after heating for 30 minutes at 72°C in APT-broth in at least three tests out of six. The most noticeable result of the study was the occurence of heat-resistant pseudomonads in the core. It must be pointed out that all pseudomonads found survived after heating for 60 minutes at 72°C in APT-broth, and often after heating for 15 minutes at 72°C in coarsely ground cured pork (core 72°C. The cfu number of the two most heat-resistant streptococcus strains decreased only 1 log unit over 15 minutes at 72°C in coarsely ground cured pork. The numbers of inoculated pseudomonads decreased but those of streptococci rose by a maximum of 1 log unit when the experimental porks were kept at 4°C after heating. This indicates that streptococci and pseudomonads probably do not constitute a serious spoilage factor in cooked meat products, but spoilage is generally effected by bacteria which have contaminated the surface layer of the products after heat treatment.

Bacterial Diversity and Nitrogen Utilization Strategies in the Upper Layer of the Northwestern Pacific Ocean.

Science.gov (United States)

Li, Yuan-Yuan; Chen, Xiao-Huang; Xie, Zhang-Xian; Li, Dong-Xu; Wu, Peng-Fei; Kong, Ling-Fen; Lin, Lin; Kao, Shuh-Ji; Wang, Da-Zhi

2018-01-01

Nitrogen (N) is a primary limiting nutrient for bacterial growth and productivity in the ocean. To better understand bacterial community and their N utilization strategy in different N regimes of the ocean, we examined bacterial diversity, diazotrophic diversity, and N utilization gene expressions in the northwestern Pacific Ocean (NWPO) using a combination of high-throughput sequencing and real-time qPCR methods. 521 and 204 different operational taxonomic units (OTUs) were identified in the 16s rRNA and nifH libraries from nine surface samples. Of the 16s rRNA gene OTUs, 11.9% were observed in all samples while 3.5 and 15.9% were detected only in N-sufficient and N-deficient samples. Proteobacteria, Cyanobacteria and Bacteroidetes dominated the bacterial community. Prochlorococcus and Pseudoalteromonas were the most abundant at the genus level in N-deficient regimes, while SAR86, Synechococcus and SAR92 were predominant in the Kuroshio-Oyashio confluence region. The distribution of the nifH gene presented great divergence among sampling stations: Cyanobacterium_UCYN-A dominated the N-deficient stations, while clusters related to the Alpha-, Beta- , and Gamma-Proteobacteria were abundant in other stations. Temperature was the main factor that determined bacterial community structure and diversity while concentration of NO X -N was significantly correlated with structure and distribution of N 2 -fixing microorganisms. Expression of the ammonium transporter was much higher than that of urea transporter subunit A ( urtA ) and ferredoxin-nitrate reductase , while urtA had an increased expression in N-deficient surface water. The predicted ammonium transporter and ammonium assimilation enzymes were most abundant in surface samples while urease and nitrogenase were more abundant in the N-deficient regions. These findings underscore the fact that marine bacteria have evolved diverse N utilization strategies to adapt to different N habitats, and that urea metabolism is of

Bacterial Diversity and Nitrogen Utilization Strategies in the Upper Layer of the Northwestern Pacific Ocean

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Yuan-Yuan Li

2018-04-01

Full Text Available Nitrogen (N is a primary limiting nutrient for bacterial growth and productivity in the ocean. To better understand bacterial community and their N utilization strategy in different N regimes of the ocean, we examined bacterial diversity, diazotrophic diversity, and N utilization gene expressions in the northwestern Pacific Ocean (NWPO using a combination of high-throughput sequencing and real-time qPCR methods. 521 and 204 different operational taxonomic units (OTUs were identified in the 16s rRNA and nifH libraries from nine surface samples. Of the 16s rRNA gene OTUs, 11.9% were observed in all samples while 3.5 and 15.9% were detected only in N-sufficient and N-deficient samples. Proteobacteria, Cyanobacteria and Bacteroidetes dominated the bacterial community. Prochlorococcus and Pseudoalteromonas were the most abundant at the genus level in N-deficient regimes, while SAR86, Synechococcus and SAR92 were predominant in the Kuroshio-Oyashio confluence region. The distribution of the nifH gene presented great divergence among sampling stations: Cyanobacterium_UCYN-A dominated the N-deficient stations, while clusters related to the Alpha-, Beta-, and Gamma-Proteobacteria were abundant in other stations. Temperature was the main factor that determined bacterial community structure and diversity while concentration of NOX-N was significantly correlated with structure and distribution of N2-fixing microorganisms. Expression of the ammonium transporter was much higher than that of urea transporter subunit A (urtA and ferredoxin-nitrate reductase, while urtA had an increased expression in N-deficient surface water. The predicted ammonium transporter and ammonium assimilation enzymes were most abundant in surface samples while urease and nitrogenase were more abundant in the N-deficient regions. These findings underscore the fact that marine bacteria have evolved diverse N utilization strategies to adapt to different N habitats, and that urea

Identification of bacterial strains isolated from the Mediterranean Sea exhibiting different abilities of biofilm formation.

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Brian-Jaisson, Florence; Ortalo-Magné, Annick; Guentas-Dombrowsky, Linda; Armougom, Fabrice; Blache, Yves; Molmeret, Maëlle

2014-07-01

The Mediterranean Sea has rarely been investigated for the characterization of marine bacteria as compared to other marine environments such as the Atlantic or Pacific Ocean. Bacteria recovered from inert surfaces are poorly studied in these environments, when it has been shown that the community structure of attached bacteria can be dissimilar from that of planktonic bacteria present in the water column. The objectives of this study were to identify and characterize marine bacteria isolated from biofilms developed on inert surfaces immersed in the Mediterranean Sea and to evaluate their capacity to form a biofilm in vitro. Here, 13 marine bacterial strains have been isolated from different supports immersed in seawater in the Bay of Toulon (France). Phylogenetic analysis and different biological and physico-chemical properties have been investigated. Among the 13 strains recovered, 8 different genera and 12 different species were identified including 2 isolates of a novel bacterial species that we named Persicivirga mediterranea and whose genus had never been isolated from the Mediterranean Sea. Shewanella sp. and Pseudoalteromonas sp. were the most preponderant genera recovered in our conditions. The phenotypical characterization revealed that one isolate belonging to the Polaribacter genus differed from all the other ones by its hydrophobic properties and poor ability to form biofilms in vitro. Identifying and characterizing species isolated from seawater including from Mediterranean ecosystems could be helpful for example, to understand some aspects of bacterial biodiversity and to further study the mechanisms of biofilm (and biofouling) development in conditions approaching those of the marine environment.

Spatial variation in deposition rate coefficients of an adhesion-deficient bacterial strain in quartz sand.

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Tong, Meiping; Camesano, Terri A; Johnson, William P

2005-05-15

The transport of bacterial strain DA001 was examined in packed quartz sand under a variety of environmentally relevant ionic strength and flow conditions. Under all conditions, the retained bacterial concentrations decreased with distance from the column inlet at a rate that was faster than loglinear, indicating that the deposition rate coefficient decreased with increasing transport distance. The hyperexponential retained profile contrasted againstthe nonmonotonic retained profiles that had been previously observed for this same bacterial strain in glass bead porous media, demonstrating that the form of deviation from log-linear behavior is highly sensitive to system conditions. The deposition rate constants in quartz sand were orders of magnitude below those expected from filtration theory, even in the absence of electrostatic energy barriers. The degree of hyperexponential deviation of the retained profiles from loglinear behavior did not decrease with increasing ionic strength in quartz sand. These observations demonstrate thatthe observed low adhesion and deviation from log-linear behavior was not driven by electrostatic repulsion. Measurements of the interaction forces between DA001 cells and the silicon nitride tip of an atomic force microscope (AFM) showed that the bacterium possesses surface polymers with an average equilibrium length of 59.8 nm. AFM adhesion force measurements revealed low adhesion affinities between silicon nitride and DA001 polymers with approximately 95% of adhesion forces having magnitudes responsible for the low adhesion to silicon nitride, indicating that steric interactions from extracellular polymers controlled DA001 adhesion deficiency and deviation from log-linear behavior on quartz sand.

Mutagenic and antimutagenic activities of Artemisia absinthium volatile oil by the bacterial reverse mutation assay in Salmonella typhimurium strains TA98 and TA100

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Mahboubeh Taherkhani

2014-09-01

Full Text Available Objective: To investigate the mutagenic and antimutagenic activities of Artemisia absinthium L. (A. absinthium essential oil by the bacterial reverse mutation assay in Salmonella typhimurium (S. typhimurium strains. Methods: Water-distilled essential oil of A. absinthium collected from Ardabil, NorthWestern Iran, was investigated for mutagenic and antimutagenic activities. In present study, the mutagenic and antimutagenic activities of A. absinthium oil were investigated by the bacterial revere mutation assay in S. typhimurium TA98 and TA100 strains with and without S9 (microsomal mutagenesis assay. Results: The comparative mutagenicity effect was seen in 1.5 mg/plate by the bacterial reverse mutation assay in S. typhimurium TA98 strains, without S9 and the excellent antimutagenicity effect was seen in 1.5 mg/plate against S. typhimurium TA100, without S9. Conclusions: The mutagenicity and antimutagenicity effects of the volatile oil of A. absinthium were seen without the presence of metabolic activation.

Effects of inoculation with organic-phosphorus-mineralizing bacteria on soybean (Glycine max) growth and indigenous bacterial community diversity.

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Sun, Wei; Qian, Xun; Gu, Jie; Wang, Xiao-Juan; Li, Yang; Duan, Man-Li

2017-05-01

Three different organic-phosphorus-mineralizing bacteria (OPMB) strains were inoculated to soil planted with soybean (Glycine max), and their effects on soybean growth and indigenous bacterial community diversity were investigated. Inoculation with Pseudomonas fluorescens Z4-1 and Brevibacillus agri L7-1 increased organic phosphorus degradation by 22% and 30%, respectively, compared with the control at the mature stage. Strains P. fluorescens Z4-1 and B. agri L7-1 significantly improved the soil alkaline phosphatase activity, average well color development, and the soybean root activity. Terminal restriction fragment length polymorphism analysis demonstrated that P. fluorescens Z4-1 and B. agri L7-1 could persist in the soil at relative abundances of 2.0%-6.4% throughout soybean growth. Thus, P. fluorescens Z4-1 and B. agri L7-1 could potentially be used in organic-phosphorus-mineralizing biofertilizers. OPMB inoculation altered the genetic structure of the soil bacterial communities but had no apparent influence on the carbon source utilization profiles of the soil bacterial communities. Principal components analysis showed that the changes in the carbon source utilization profiles of bacterial community depended mainly on the plant growth stages rather than inoculation with OPMB. The results help to understand the evolution of the soil bacterial community after OPMB inoculation.

Development of Rare Bacterial Monosaccharide Analogs for Metabolic Glycan Labeling in Pathogenic Bacteria.

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Clark, Emily L; Emmadi, Madhu; Krupp, Katharine L; Podilapu, Ananda R; Helble, Jennifer D; Kulkarni, Suvarn S; Dube, Danielle H

2016-12-16

Bacterial glycans contain rare, exclusively bacterial monosaccharides that are frequently linked to pathogenesis and essentially absent from human cells. Therefore, bacterial glycans are intriguing molecular targets. However, systematic discovery of bacterial glycoproteins is hampered by the presence of rare deoxy amino sugars, which are refractory to traditional glycan-binding reagents. Thus, the development of chemical tools that label bacterial glycans is a crucial step toward discovering and targeting these biomolecules. Here, we explore the extent to which metabolic glycan labeling facilitates the studying and targeting of glycoproteins in a range of pathogenic and symbiotic bacterial strains. We began with an azide-containing analog of the naturally abundant monosaccharide N-acetylglucosamine and discovered that it is not broadly incorporated into bacterial glycans, thus revealing a need for additional azidosugar substrates to broaden the utility of metabolic glycan labeling in bacteria. Therefore, we designed and synthesized analogs of the rare deoxy amino d-sugars N-acetylfucosamine, bacillosamine, and 2,4-diacetamido-2,4,6-trideoxygalactose and established that these analogs are differentially incorporated into glycan-containing structures in a range of pathogenic and symbiotic bacterial species. Further application of these analogs will refine our knowledge of the glycan repertoire in diverse bacteria and may find utility in treating a variety of infectious diseases with selectivity.

Comparison and Analysis of Lithium Bromide-water Absorption Chillers Using Plastic Heat Transfer Tubes and Traditional Lithium Bromide-water Absorption Chillers

OpenAIRE

Xue-dong Zhang

2010-01-01

There are extensive applications of lithium bromide-water absorption chillers in industry, but the heat exchangers corrosion and refrigerating capacity loss are very difficult to be solved. In this paper, an experiment was conducted by using plastic heat transfer tubes instead of copper tubes. As an example, for a lithium bromide-water absorption chiller of refrigerating capacity of 35kW, the correlative performance of the lithium bromide-water absorption chiller using pl...

Experimental infection with different bacterial strains in larvae and juvenile Litopenaeus vannamei reared in Santa Catarina State, Brazil - doi: 10.4025/actascibiolsci.v32i3.5471 Experimental infection with different bacterial strains in larvae and juvenile Litopenaeus vannamei reared in Santa Catarina State, Brazil - doi: 10.4025/actascibiolsci.v32i3.5471

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Adolfo Jatoba

2010-09-01

Full Text Available This study evaluated the pathogenic characteristics of bacteria isolated from Litopenaeus vannamei during an outbreak at the Laboratory of Marine Shrimp, UFSC, Santa Catarina State, Brazil. Their virulence potential in larvae and juvenile shrimp and the effects on the total haemocyte count, phenoloxidase activity and serum agglutinate titre were examined after experimental infection. Bacterial strains were isolated from larvae and adult shrimps, identified by the AP120E biochemical system as: two strains of Vibrio alginolyticus, three of Aeromonas salmonicida and one of Pasteurella multocida sp. and Pasteurella sp. All the bacterial strains isolated in this study caused mortality in shrimp. One strain of V. alginolyticus was responsible for 97.3 and 88.7% mortality in larvae and juvenil shrimps, respectively. The shrimp immunological system was influenced by experimental infection with V. alginolyticus. Decrease in the total haemocyte count and increase in the phenoloxidase activity and the serum agglutinate titre (p V. alginolyticus isolated from larvae and juvenile reared marine shrimp.This study evaluated the pathogenic characteristics of bacteria isolated from Litopenaeus vannamei during an outbreak at the Laboratory of Marine Shrimp, UFSC, Santa Catarina State, Brazil. Their virulence potential in larvae and juvenile shrimp and the effects on the total haemocyte count, phenoloxidase activity and serum agglutinate titre were examined after experimental infection. Bacterial strains were isolated from larvae and adult shrimps, identified by the AP120E biochemical system as: two strains of Vibrio alginolyticus, three of Aeromonas salmonicida and one of Pasteurella multocida sp. and Pasteurella sp. All the bacterial strains isolated in this study caused mortality in shrimp. One strain of V. alginolyticus was responsible for 97.3 and 88.7% mortality in larvae and juvenil shrimps, respectively. The shrimp immunological system was influenced by

Disinfection byproduct regulatory compliance surrogates and bromide-associated risk.

Science.gov (United States)

Kolb, Chelsea; Francis, Royce A; VanBriesen, Jeanne M

2017-08-01

Natural and anthropogenic factors can alter bromide concentrations in drinking water sources. Increasing source water bromide concentrations increases the formation and alters the speciation of disinfection byproducts (DBPs) formed during drinking water treatment. Brominated DBPs are more toxic than their chlorinated analogs, and thus have a greater impact on human health. However, DBPs are regulated based on the mass sum of DBPs within a given class (e.g., trihalomethanes and haloacetic acids), not based on species-specific risk or extent of bromine incorporation. The regulated surrogate measures are intended to protect against not only the species they directly represent, but also against unregulated DBPs that are not routinely measured. Surrogates that do not incorporate effects of increasing bromide may not adequately capture human health risk associated with drinking water when source water bromide is elevated. The present study analyzes trihalomethanes (THMs), measured as TTHM, with varying source water bromide concentrations, and assesses its correlation with brominated THM, TTHM risk and species-specific THM concentrations and associated risk. Alternative potential surrogates are evaluated to assess their ability to capture THM risk under different source water bromide concentration conditions. The results of the present study indicate that TTHM does not adequately capture risk of the regulated species when source water bromide concentrations are elevated, and thus would also likely be an inadequate surrogate for many unregulated brominated species. Alternative surrogate measures, including THM 3 and the bromodichloromethane concentration, are more robust surrogates for species-specific THM risk at varying source water bromide concentrations. Copyright © 2017. Published by Elsevier B.V.

Biodegradation of furfural by Bacillus subtilis strain DS3.

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Zheng, Dan; Bao, Jianguo; Lu, Jueming; Lv, Quanxi

2015-07-01

An aerobic bacterial strain DS3, capable of growing on furfural as sole carbon source, was isolated from actived sludge of wastewater treatment plant in a diosgenin factory after enrichment. Based on morphological physiological tests as well as 16SrDNA sequence and Biolog analyses it was identified as Bacillus subtilis. The study revealed that strain DS3 utilized furfural, as analyzed by high-performance liquid chromatography (HPLC). Under following conditions: pH 8.0, temperature 35 degrees C, 150 rpm and 10% inoculum, strain DS3 showed 31.2% furfural degradation. Furthermore, DS3 strain was found to tolerate furfural concentration as high as 6000 mg(-1). The ability of Bacillus subtilis strain DS3 to degrade furfural has been demonstrated for the first time in the present study.

Degradation of 1,2-Dibromoethane by Mycobacterium sp. Strain GP1

NARCIS (Netherlands)

Poelarends, Gerrit J.; van Hylckama Vlieg, Johannes; Marchesi, Julian R.; Freitas dos Santos, Luisa M.; Janssen, Dick B.

The newly isolated bacterial strain GP1 can utilize 1,2-dibromoethane as the sole carbon and energy source. On the basis of 16S rRNA gene sequence analysis, the organism was identified as a member of the subgroup which contains the fast-growing mycobacteria, The first step in 1,2-dibromoethane

Power Plant Bromide Discharges and Downstream Drinking Water Systems in Pennsylvania.

Science.gov (United States)

Good, Kelly D; VanBriesen, Jeanne M

2017-10-17

Coal-fired power plants equipped with wet flue gas desulfurization (FGD) systems have been implicated in increasing bromide levels and subsequent increases in disinfection byproducts at downstream drinking water plants. Bromide was not included as a regulated constituent in the recent steam electric effluent limitations guidelines and standards (ELGs) since the U.S. EPA analysis suggested few drinking water facilities would be affected by bromide discharges from power plants. The present analysis uses a watershed approach to identify Pennsylvania drinking water intakes downstream of wet FGD discharges and to assess the potential for bromide discharge effects. Twenty-two (22) public drinking water systems serving 2.5 million people were identified as being downstream of at least one wet FGD discharge. During mean August conditions (generally low-flow, minimal dilution) in receiving rivers, the median predicted bromide concentrations contributed by wet FGD at Pennsylvania intake locations ranged from 5.2 to 62 μg/L for the Base scenario (including only natural bromide in coal) and from 16 to 190 μg/L for the Bromide Addition scenario (natural plus added bromide for mercury control); ranges depend on bromide loads and receiving stream dilution capacity.

New Parameters to Quantitatively Express the Invasiveness of Bacterial Strains from Implant-Related Orthopaedic Infections into Osteoblast Cells.

Science.gov (United States)

Campoccia, Davide; Montanaro, Lucio; Ravaioli, Stefano; Cangini, Ilaria; Testoni, Francesca; Visai, Livia; Arciola, Carla Renata

2018-04-03

Complete eradication of bacterial infections is often a challenging task, especially in presence of prosthetic devices. Invasion of non-phagocytic host cells appears to be a critical mechanism of microbial persistence in host tissues. Hidden within host cells, bacteria elude host defences and antibiotic treatments that are intracellularly inactive. The intracellular invasiveness of bacteria is generally measured by conventional gentamicin protection assays. The efficiency of invasion, however, markedly differs across bacterial species and adjustments to the titre of the microbial inocula used in the assays are often needed to enumerate intracellular bacteria. Such changes affect the standardisation of the method and hamper a direct comparison of bacteria on a same scale. This study aims at investigating the precise relation between inoculum, in terms of multiplicity of infection (MOI), and internalised bacteria. The investigation included nine Staphylococcus aureus , seven Staphylococcus epidermidis , five Staphylococcus lugdunensis and two Enterococcus faecalis clinical strains, which are co-cultured with MG63 human osteoblasts. Unprecedented insights are offered on the relations existing between MOI, number of internalised bacteria and per cent of internalised bacteria. New parameters are identified that are of potential use for qualifying the efficiency of internalization and compare the behaviour of bacterial strains.

New Parameters to Quantitatively Express the Invasiveness of Bacterial Strains from Implant-Related Orthopaedic Infections into Osteoblast Cells

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Davide Campoccia

2018-04-01

Full Text Available Complete eradication of bacterial infections is often a challenging task, especially in presence of prosthetic devices. Invasion of non-phagocytic host cells appears to be a critical mechanism of microbial persistence in host tissues. Hidden within host cells, bacteria elude host defences and antibiotic treatments that are intracellularly inactive. The intracellular invasiveness of bacteria is generally measured by conventional gentamicin protection assays. The efficiency of invasion, however, markedly differs across bacterial species and adjustments to the titre of the microbial inocula used in the assays are often needed to enumerate intracellular bacteria. Such changes affect the standardisation of the method and hamper a direct comparison of bacteria on a same scale. This study aims at investigating the precise relation between inoculum, in terms of multiplicity of infection (MOI, and internalised bacteria. The investigation included nine Staphylococcus aureus, seven Staphylococcus epidermidis, five Staphylococcus lugdunensis and two Enterococcus faecalis clinical strains, which are co-cultured with MG63 human osteoblasts. Unprecedented insights are offered on the relations existing between MOI, number of internalised bacteria and per cent of internalised bacteria. New parameters are identified that are of potential use for qualifying the efficiency of internalization and compare the behaviour of bacterial strains.

Antibiotic Resistance and Virulence Phenotypes of Recent Bacterial Strains Isolated from Urinary Tract Infections in Elderly Patients with Prostatic Disease

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Cristina Delcaru

2017-05-01

Full Text Available Acute bacterial prostatitis is one of the frequent complications of urinary tract infection (UTI. From the approximately 10% of men having prostatitis, 7% experience a bacterial prostatitis. The purpose of this study was to investigate the prevalence of uropathogens associated with UTIs in older patients with benign prostatic hyperplasia and to assess their susceptibility to commonly prescribed antibiotics as well as the relationships between microbial virulence and resistance features. Uropathogenic Escherichia coli was found to be the most frequent bacterial strain isolated from patients with benign prostatic hyperplasia, followed by Enterococcus spp., Enterobacter spp., Klebsiella spp., Proteus spp., Pseudomonas aeruginosa, and Serratia marcescens. Increased resistance rates to tetracyclines, quinolones, and sulfonamides were registered. Besides their resistance profiles, the uropathogenic isolates produced various virulence factors with possible implications in the pathogenesis process. The great majority of the uropathogenic isolates revealed a high capacity to adhere to HEp-2 cell monolayer in vitro, mostly exhibiting a localized adherence pattern. Differences in the repertoire of soluble virulence factors that can affect bacterial growth and persistence within the urinary tract were detected. The Gram-negative strains produced pore-forming toxins—such as hemolysins, lecithinases, and lipases—proteases, siderophore-like molecules resulted from the esculin hydrolysis and amylases, while Enterococcus sp. strains were positive only for caseinase and esculin hydrolase. Our study demonstrates that necessity of investigating the etiology and local resistance patterns of uropathogenic organisms, which is crucial for determining appropriate empirical antibiotic treatment in elderly patients with UTI, while establishing correlations between resistance and virulence profiles could provide valuable input about the clinical evolution and

Improving nitrogen utilization efficiency of aquaponics by introducing algal-bacterial consortia.

Science.gov (United States)

Fang, Yingke; Hu, Zhen; Zou, Yina; Zhang, Jian; Zhu, Zhuoran; Zhang, Jianda; Nie, Lichao

2017-12-01

Aquaponics is a promising technology combining aquaculture with hydroponics. In this study, algal-bacterial consortia were introduced into aquaponics, i.e., algal-bacterial based aquaponics (AA), to improve the nitrogen utilization efficiency (NUE) of aquaponics. The results showed that the NUE of AA was 13.79% higher than that of media-based aquaponics (MA). In addition, higher NO 3 - removal by microalgae assimilation led to better water quality in AA, which made up for the deficiencies of poor aquaponic management of nitrate. As a result of lower NO 3 - concentrations and dramatically higher dissolved oxygen (DO) concentrations caused by microalgae photosynthesis in the photobioreactor, the N 2 O emission of AA was 89.89% lower than that of MA, although nosZ gene abundance in MA's hydroponic bed was approximately 30 times over that in AA. Considering the factors mentioned above, AA would improve the sustainability of aquaponics and have a good application foreground. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Characterization of a bacterial biocontrol strain 1404 and its efficacy in controlling postharvest citrus anthracnose].

Science.gov (United States)

Wang, Qian; Hu, Chunjin; Ke, Fanggang; Huang, Siliang; Li, Qiqin

2010-09-01

Anthracnose caused by Colletotrichum gloeosporioides (Penz.) Sacc. is a main disease in citrus production. To develop an effective biocontrol measure against citrus postharvest anthracnose, we screened antagonistic microbes and obtained a bacterial strain 1404 from the rhizospheric soil of chili plants in Nanning city, Guangxi, China. The objectives of the present study were to: (1) identify and characterize the antagonistic bacterium; and (2) to evaluate the efficacy of the antagonistic strain in controlling citrus postharvest anthracnose disease. Strain 1404 was identified by comparing its 16S rDNA sequence with related bacteria from GenBank database, as well as analyzing its morphological, physiological and biochemical characters. The antagonistic stability of the strain 1404 was determined by continuously transferring it on artificial media. The effect of the strain on suppressing citrus anthracnose at postharvest stage was tested by stab inoculation method. The 16S rDNA of strain 1404 was amplified with primers PF1 (5'-AGAGTTTGATCATGGCTCAG-3') and PR1 (5'-TACGGTTACCTTGTTACGACTT-3') and its sequence submitted to GenBank (accession number: GU361113). Strain 1404 clustered with the GenBank-derived Brevibacillus brevis strains in the 16S-rDNA-sequence-based phylogenetic tree at 100% bootstrap level. The morphological traits, physiological and biochemical characters of strain 1404 agreed with that of Brevibacillus brevis. Less change in the suppressive ability of antagonist against growth of Colletotrichum gloeosporioides was observed during four continuous transfers on artificial media. The average control efficacy of the strain was 64. 9 % against the disease 20 days after the antagonist application. Strain 1404 was identified as Brevibacillus brevis based on its morphological traits, phyiological and biochemical characters as well as 16S rDNA sequence analysis. The antagonist was approved to be a promising biocontrol agent. This is the first report of

Facile method to stain the bacterial cell surface for super-resolution fluorescence microscopy

Energy Technology Data Exchange (ETDEWEB)

Gunsolus, Ian L.; Hu, Dehong; Mihai, Cosmin; Lohse, Samuel E.; Lee, Chang-Soo; Torelli, Marco; Hamers, Robert J.; Murphy, Catherine; Orr, Galya; Haynes, Christy L.

2014-01-01

A method to fluorescently stain the surfaces of both Gram-negative and Gram-positive bacterial cells compatible with super-resolution fluorescence microscopy is presented. This method utilizes a commercially-available fluorescent probe to label primary amines at the surface of the cell. We demonstrate efficient staining of two bacterial strains, the Gram-negative Shewanella oneidensis MR-1 and the Gram-positive Bacillus subtilis 168. Using structured illumination microscopy and stochastic optical reconstruction microscopy, which require high quantum yield or specialized dyes, we show that this staining method may be used to resolve the bacterial cell surface with sub-diffraction-limited resolution. We further use this method to identify localization patterns of nanomaterials, specifically cadmium selenide quantum dots, following interaction with bacterial cells.

On the distribution of bromide and bromide/chlorinity ratios in the waters of the Arabian sea off central Indian coast

Digital Repository Service at National Institute of Oceanography (India)

DeSouza, F.P.; SenGupta, R.

Water samples from surface to 2000 m depth at two stations in the Arabian Sea collected during the 82nd cruise of R V Gaveshani in November, 1980 were analysed for bromide. The average bromide concentration was 0.068 g/kg plus or minus 0...

Hexavalent chromium reduction by bacterial consortia and pure strains from an alkaline industrial effluent.

Science.gov (United States)

Piñón-Castillo, H A; Brito, E M S; Goñi-Urriza, M; Guyoneaud, R; Duran, R; Nevarez-Moorillon, G V; Gutiérrez-Corona, J F; Caretta, C A; Reyna-López, G E

2010-12-01

To characterize the bacterial consortia and isolates selected for their role in hexavalent chromium removal by adsorption and reduction. Bacterial consortia from industrial wastes revealed significant Cr(VI) removal after 15 days when incubated in medium M9 at pH 6·5 and 8·0. The results suggested chromium reduction. The bacterial consortia diversity (T-RFLP based on 16S rRNA gene) indicated a highest number of operational taxonomic units in an alkaline carbonate medium mimicking in situ conditions. However, incubations under such conditions revealed low Cr(VI) removal. Genomic libraries were obtained for the consortia exhibiting optimal Cr(VI) removal (M9 medium at pH 6·5 and 8·0). They revealed the dominance of 16S rRNA gene sequences related to the genera Pseudomonas/Stenotrophomonas or Enterobacter/Halomonas, respectively. Isolates related to Pseudomonas fluorescens and Enterobacter aerogenes were efficient in Cr(VI) reduction and adsorption to the biomass. Cr(VI) reduction was better at neutral pH rather than under in situ conditions (alkaline pH with carbonate). Isolated strains exhibited significant capacity for Cr(VI) reduction and adsorption. Bacterial communities from chromium-contaminated industrial wastes as well as isolates were able to remove Cr(VI). The results suggest a good potential for bioremediation of industrial wastes when optimal conditions are applied. Journal of Applied Microbiology © 2010 The Society for Applied Microbiology. No claim to Mexican Government works.

The physicochemical properties of the low-temperature ionic liquid silver bromide-1-butyl-3-methylimidazolium bromide

Science.gov (United States)

Grishina, E. P.; Ramenskaya, L. M.; Pimenova, A. M.

2009-11-01

The physicochemical properties of the low-temperature ionic liquid based on 1-butyl-3-methylimidazolium bromide (BMImBr) and silver bromide were studied. Differential scanning calorimetry, Fourier transform IR spectroscopy, densimetry, viscometry, and conductometry measurements were performed to determine the dependences of the parameters under study on the concentration of AgBr. It was shown that the temperature and concentration behavior of the physicochemical properties of BMImBr-AgBr melts characterized the interaction between the system components with the formation of complex particles.

Isolation, screening and molecular identification of novel bacterial strain removing methylene blue from water solutions

Science.gov (United States)

Kilany, Mona

2017-11-01

The potentially deleterious effects of methylene blue (MB) on human health drove the interest in its removal promptly. Bioremediation is an effective and eco friendly for removing MB. Soil bacteria were isolated and examined for their potential to remove MB. The most potent bacterial candidate was characterized and identified using 16S rRNA sequence technique. The evolutionary history of the isolate was conducted by maximum likelihood method. Some physiochemical parameters were optimized for maximum decolorization. Decolorization mechanism and microbial toxicity study of MB (100 mg/l) and by-products were investigated. Participation of heat killed bacteria in color adsorption have been investigated too. The bacterial isolate was identified as Stenotrophomonas maltophilia strain Kilany_MB 16S ribosomal RNA gene with 99% sequence similarity. The sequence was submitted to NCBI (Accession number = KU533726). Phylogeny depicted the phylogenetic relationships between 16S ribosomal RNA gene, partial sequence (1442 bp), of the isolated strain and other strains related to Stenotrophomonas maltophilia in the GenBank database. The optimal conditions were investigated to be pH 5 at 30 °C, after 24 h using 5 mg/l MB showing optimum decolorization percentage (61.3%). Microbial toxicity study demonstrated relative reduction in the toxicity of MB decolorized products on test bacteria. Mechanism of color removal was proved by both biosorption and biodegradation, where heat-killed and live cells showed 43 and 52% of decolorization, respectively, as a maximum value after 24-h incubation. It was demonstrated that the mechanism of color removal is by adsorption. Therefore, good performance of S maltophilia in MB color removal reinforces the exploitation of these bacteria in environmental clean-up and restoration of the ecosystem.

Soil microbial species loss affects plant biomass and survival of an introduced bacterial strain, but not inducible plant defences

NARCIS (Netherlands)

Kurm, Viola; van der Putten, W.H.; Pineda, A.M.; Hol, W.H.G.

2018-01-01

• Background and Aims Plant growth-promoting rhizobacteria (PGPR) strains can influence plant–insect interactions. However, little is known about the effect of changes in the soil bacterial community in general and especially the loss of rare soil microbes on these interactions. Here, the influence

Soil microbial species loss affects plant biomass and survival of an introduced bacterial strain, but not inducible plant defences

NARCIS (Netherlands)

Kurm, Viola; Putten, Van Der Wim H.; Pineda, Ana; Hol, G.W.H.

2018-01-01

• Background and Aims: Plant growth-promoting rhizobacteria (PGPR) strains can influence plant-insect interactions. However, little is known about the effect of changes in the soil bacterial community in general and especially the loss of rare soil microbes on these interactions. Here, the influence

Examining the interrelationship between DOC, bromide and chlorine dose on DBP formation in drinking water--a case study.

Science.gov (United States)

Bond, Tom; Huang, Jin; Graham, Nigel J D; Templeton, Michael R

2014-02-01

During drinking water treatment aqueous chlorine and bromine compete to react with natural organic matter (NOM). Among the products of these reactions are potentially harmful halogenated disinfection by-products, notably four trihalomethanes (THM4) and nine haloacetic acids (HAAs). Previous research has concentrated on the role of bromide in chlorination reactions under conditions of a given NOM type and/or concentration. In this study different concentrations of dissolved organic carbon (DOC) from U.K. lowland water were reacted with varying amounts of bromide and chlorine in order to examine the interrelationship between the three reactants in the formation of THM4, dihaloacetic acids (DHAAs) and trihaloacetic acids (THAAs). Results showed that, in general, molar yields of THM4 increased with DOC, bromide and chlorine concentrations, although yields did fluctuate versus chlorine dose. In contrast both DHAA and THAA yields were mainly independent of changes in bromide and chlorine dose at low DOC (1 mg·L(-1)), but increased with chlorine dose at higher DOC concentrations (4 mg·L(-1)). Bromine substitution factors reached maxima of 0.80, 0.67 and 0.65 for the THM4, DHAAs and THAAs, respectively, at the highest bromide/chlorine ratio studied. These results suggest that THM4 formation kinetics depend on both oxidation and halogenation steps, whereas for DHAAs and THAAs oxidation steps are more important. Furthermore, they indicate that high bromide waters may prove more problematic for water utilities with respect to THM4 formation than for THAAs or DHAAs. While mass concentrations of all three groups increased in response to increased bromide incorporation, only the THMs also showed an increase in molar yield. Overall, the formation behaviour of DHAA and THAA was more similar than that of THM4 and THAA. © 2013.

Identification of thermophilic bacterial strains producing thermotolerant hydrolytic enzymes from manure compost.

Science.gov (United States)

Charbonneau, David M; Meddeb-Mouelhi, Fatma; Boissinot, Maurice; Sirois, Marc; Beauregard, Marc

2012-03-01

Ten thermophilic bacterial strains were isolated from manure compost. Phylogenetic analysis based on 16S rRNA genes and biochemical characterization allowed identification of four different species belonging to four genera: Geobacillus thermodenitrificans, Bacillus smithii, Ureibacillus suwonensis and Aneurinibacillus thermoaerophilus. PCR-RFLP profiles of the 16S-ITS-23S rRNA region allowed us to distinguish two subgroups among the G. thermodenitrificans isolates. Isolates were screened for thermotolerant hydrolytic activities (60-65°C). Thermotolerant lipolytic activities were detected for G. thermodenitrificans, A. thermoaerophilus and B. smithii. Thermotolerant protease, α-amylase and xylanase activities were also observed in the G. thermodenitrificans group. These species represent a source of potential novel thermostable enzymes for industrial applications.

Isolation and characterization of bacterial endophytes of Curcuma longa L.

Science.gov (United States)

Kumar, Ajay; Singh, Ritu; Yadav, Akhilesh; Giri, D D; Singh, P K; Pandey, Kapil D

2016-06-01

Fourteen endophytic bacterial isolates were isolated from the rhizome of Curcuma longa L. were characterized on the basis of morphology, biochemical characteristics and 16S rRNA gene sequence analysis. The isolates were identified to six strains namely Bacillus cereus (ECL1), Bacillus thuringiensis (ECL2), Bacillus sp. (ECL3), Bacillus pumilis (ECL4), Pseudomonas putida (ECL5), and Clavibacter michiganensis (ECL6). All the strains produced IAA and solubilized phosphate and only two strains produced siderophore (ECL3 and ECL5) during plant growth promoting trait analysis. All the endophytic strains utilized glucose, sucrose and yeast extract as a carbon source where as glycine, alanine, cystine and glutamine as nitrogen source. The strains were mostly sensitive to antibiotic chloramphenicol followed by erythromycin while resistant to polymixin B. The endophytic strains effectively inhibit the growth of Escherichia coli, Klebsiella pneumoniae and some of the fungal strain like Fusarium solani and Alterneria alternata. The strain ECL2 and ECL4 tolerated maximum 8 % of NaCl concentration where as strains ECL5 and ECL6 6 % in salinity tolerance.

Effect of ipratropium bromide in bronchial asthma.

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Taskar V

1992-07-01

Full Text Available The effect of inhalation of ipratropium bromide was evaluated in 20 patients with bronchial asthma. It was observed that there was no significant improvement in the forced vital capacity and the forced expired volume in one second, while there was significant improvement in the peak expiratory flow rate (PEFR measured at 9 pm, after inhalation of 2 puffs of ipratropium bromide aerosol (0.02mg/puff three to four times a day for 2 weeks. Since PEFR is a measure of large airway function and cholinergic mechanisms are primarily involved for airflow obstruction at large airways, improvement in PEFR by ipratropium bromide highlights its role as a useful bronchodilator in patients in whom vagal reflexes are responsible for the provocation of bronchoconstriction.

Modulating bacterial and gut mucosal interactions with engineered biofilm matrix proteins.

Science.gov (United States)

Duraj-Thatte, Anna M; Praveschotinunt, Pichet; Nash, Trevor R; Ward, Frederick R; Joshi, Neel S

2018-02-22

Extracellular appendages play a significant role in mediating communication between bacteria and their host. Curli fibers are a class of bacterial fimbria that is highly amenable to engineering. We demonstrate the use of engineered curli fibers to rationally program interactions between bacteria and components of the mucosal epithelium. Commensal E. coli strains were engineered to produce recombinant curli fibers fused to the trefoil family of human cytokines. Biofilms formed from these strains bound more mucins than those producing wild-type curli fibers, and modulated mucin rheology as well. When treated with bacteria producing the curli-trefoil fusions mammalian cells behaved identically in terms of their migration behavior as when they were treated with the corresponding soluble trefoil factors. Overall, this demonstrates the potential utility of curli fibers as a scaffold for the display of bioactive domains and an untapped approach to rationally modulating host-microbe interactions using bacterial matrix proteins.

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-10-15

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

Effects of liposomal-curcumin on five opportunistic bacterial strains found in the equine hindgut - preliminary study

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S. D. Bland

2017-06-01

Full Text Available Abstract Background The horse intestinal tract is sensitive and contains a highly complex microbial population. A shift in the microbial population can lead to various issues such as inflammation and colic. The use of nutraceuticals in the equine industry is on the rise and curcumin is thought to possess antimicrobial properties that may help to minimize the proliferation of opportunistic bacteria. Methods Four cecally-cannulated horses were utilized to determine the optimal dose of liposomal-curcumin (LIPC on reducing Streptococcus bovis/equinus complex (SBEC, Escherichia coli K-12, Escherichia coli general, Clostridium difficile, and Clostridium perfringens in the equine hindgut without adversely affecting cecal characteristics. In the first study cecal fluid was collected from each horse and composited for an in vitro, 24 h batch culture to examine LIPC at four different dosages (15, 20, 25, and 30 g in a completely randomized design. A subsequent in vivo 4 × 4 Latin square design study was conducted to evaluate no LIPC (control, CON or LIPC dosed at 15, 25, and 35 g per day (dosages determined from in vitro results for 9 days on the efficacy of LIPC on selected bacterial strains, pH, and volatile fatty acids. Each period was 14 days with 9 d for acclimation and 5 d withdrawal period. Results In the in vitro study dosage had no effect (P ≥ 0.42 on Clostridium strains, but as the dose increased SBEC concentrations increased (P = 0.001. Concentrations of the E. coli strain varied with dose. In vivo, LIPC’s antimicrobial properties, at 15 g, significantly decreased (P = 0.02 SBEC when compared to 25 and 35 g dosages. C. perfringens decreased linearly (P = 0.03 as LIPC dose increased. Butyrate decreased linearly (P = 0.01 as LIPC dose increased. Conclusion Further studies should be conducted with a longer dosing period to examine the antimicrobial properties of curcumin without adversely affecting cecal characteristics.

System of lithium, sodium, and strontium bromides

International Nuclear Information System (INIS)

Litvinova, G.N.; Yagub'yan, E.S.; Bukhalova, G.A.

1988-01-01

The visual-polythermal and partially differential thermal methods of analysis have been applied to investigate the meltability diagram of the Li 2 Br 2 -Na 2 Br 2 -SrBr 2 ternary system. Three fields of crystallization belonging to strontium bromide, to the compound LiSr 2 Br 5 and solid solutions of lithium and sodium bromides are found. Two points complying with nonvariant equilibria are discovered

Characterization of CRISPR-Cas system in clinical Staphylococcus epidermidis strains revealed its potential association with bacterial infection sites

DEFF Research Database (Denmark)

Li, Qiuchun; Xie, Xiaolei; Yin, Kequan

2016-01-01

Staphylococcus epidermidis is considered as a major cause of nosocomial infections, bringing an immense burden to healthcare systems. Virulent phages have been confirmed to be efficient in combating the pathogen, but the prensence of CRISPR-Cas system, which is a bacterial immune system eliminating...... phages was reported in few S. epidermidis strains. In this study, the CRISPR-Cas system was detected in 12 from almost 300 published genomes in GenBank and by PCR of cas6 gene in 18 strains out of 130 clinical isolates obtained in Copenhagen. Four strains isolated in 1965-1966 harboured CRISPR elements...... spacers located in the CRISPR1 locus with homolgy to virulent phage 6ec DNA sequences, and 19 strains each carrying 2 or 3 different spacers recognizing this phage, implied that the CRISPR-Cas immunity could be abrogated by nucleotide mismatch between the spacer and its target phage sequence, while new...

Molecular methods for bacterial genotyping and analyzed gene regions

Directory of Open Access Journals (Sweden)

İbrahim Halil Yıldırım1, Seval Cing Yıldırım2, Nadir Koçak3

2011-06-01

Full Text Available Bacterial strain typing is an important process for diagnosis, treatment and epidemiological investigations. Current bacterial strain typing methods may be classified into two main categories: phenotyping and genotyping. Phenotypic characters are the reflection of genetic contents. Genotyping, which refers discrimination of bacterial strains based on their genetic content, has recently become widely used for bacterial strain typing. The methods already used in genotypingof bacteria are quite different from each other. In this review we tried to summarize the basic principles of DNA-based methods used in genotyping of bacteria and describe some important DNA regions that are used in genotyping of bacteria. J Microbiol Infect Dis 2011;1(1:42-46.

Isolation and characterization of two new methanesulfonic acid-degrading bacterial isolates from a Portuguese soil sample.

Science.gov (United States)

De Marco, P; Murrell, J C; Bordalo, A A; Moradas-Ferreira, P

2000-02-01

Two novel bacterial strains that can utilize methanesulfonic acid as a source of carbon and energy were isolated from a soil sample collected in northern Portugal. Morphological, physiological, biochemical and molecular biological characterization of the two isolates indicate that strain P1 is a pink-pigmented facultative methylotroph belonging to the genus Methylobacterium, while strain P2 is a restricted methylotroph belonging to the genus Hyphomicrobium. Both strains are strictly aerobic, degrade methanesulfonate, and release small quantities of sulfite into the medium. Growth on methanesulfonate induces a specific polypeptide profile in each strain. This, together with the positive hybridization to a DNA probe that carries the msm genes of Methylosulfonomonas methylovora strain M2, strongly endorses the contention that a methanesulfonic acid monooxygenase related to that found in the previously known methanesulfonate-utilizing bacteria is present in strains P1 and P2. The isolation of bacteria containing conserved msm genes from diverse environments and geographical locations supports the hypothesis that a common enzyme may be globally responsible for the oxidation of methanesulfonate by natural methylotrophic communities.

Metabolic Requirements of Escherichia coli in Intracellular Bacterial Communities during Urinary Tract Infection Pathogenesis

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Matt S. Conover

2016-04-01

Full Text Available Uropathogenic Escherichia coli (UPEC is the primary etiological agent of over 85% of community-acquired urinary tract infections (UTIs. Mouse models of infection have shown that UPEC can invade bladder epithelial cells in a type 1 pilus-dependent mechanism, avoid a TLR4-mediated exocytic process, and escape into the host cell cytoplasm. The internalized UPEC can clonally replicate into biofilm-like intracellular bacterial communities (IBCs of thousands of bacteria while avoiding many host clearance mechanisms. Importantly, IBCs have been documented in urine from women and children suffering acute UTI. To understand this protected bacterial niche, we elucidated the transcriptional profile of bacteria within IBCs using microarrays. We delineated the upregulation within the IBC of genes involved in iron acquisition, metabolism, and transport. Interestingly, lacZ was highly upregulated, suggesting that bacteria were sensing and/or utilizing a galactoside for metabolism in the IBC. A ΔlacZ strain displayed significantly smaller IBCs than the wild-type strain and was attenuated during competitive infection with a wild-type strain. Similarly, a galK mutant resulted in smaller IBCs and attenuated infection. Further, analysis of the highly upregulated gene yeaR revealed that this gene contributes to oxidative stress resistance and type 1 pilus production. These results suggest that bacteria within the IBC are under oxidative stress and, consistent with previous reports, utilize nonglucose carbon metabolites. Better understanding of the bacterial mechanisms used for IBC development and establishment of infection may give insights into development of novel anti-virulence strategies.

Bacterial Diversity and Bioremediation Potential of the Highly Contaminated Marine Sediments at El-Max District (Egypt, Mediterranean Sea)

KAUST Repository

Amer, Ranya A.

2015-02-01

Coastal environments worldwide are threatened by the effects of pollution, a risk particularly high in semienclosed basins like the Mediterranean Sea that is poorly studied from bioremediation potential perspective especially in the Southern coast. Here, we investigated the physical, chemical, and microbiological features of hydrocarbon and heavy metals contaminated sediments collected at El-Max bay (Egypt). Molecular and statistical approaches assessing the structure of the sediment-dwelling bacterial communities showed correlations between the composition of bacterial assemblages and the associated environmental parameters. Fifty strains were isolated on mineral media supplemented by 1% crude oil and identified as a diverse range of hydrocarbon-degrading bacteria involved in different successional stages of biodegradation. We screened the collection for biotechnological potential studying biosurfactant production, biofilm formation, and the capability to utilize different hydrocarbons. Some strains were able to grow on multiple hydrocarbons as unique carbon source and presented biosurfactant-like activities and/or capacity to form biofilm and owned genes involved in different detoxification/degradation processes. El-Max sediments represent a promising reservoir of novel bacterial strains adapted to high hydrocarbon contamination loads. The potential of the strains for exploitation for in situ intervention to combat pollution in coastal areas is discussed.

Transient neuromyopathy after bromide intoxication in a dog with idiopathic epilepsy

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Steinmetz Sonja

2012-12-01

Full Text Available Abstract A seven-year old Australian Shepherd, suffering from idiopathic epilepsy under treatment with phenobarbitone and potassium bromide, was presented with generalised lower motor neuron signs. Electrophysiology and muscle-nerve biopsies revealed a neuromyopathy. The serum bromide concentration was increased more than two-fold above the upper reference value. Clinical signs disappeared after applying diuretics and reducing the potassium bromide dose rate. This is the first case report describing electrophysiological and histopathological findings associated with bromide induced lower motor neuron dysfunction in a dog.

Seaweed as source of energy. 1: effect of a specific bacterial strain on biogas production

Energy Technology Data Exchange (ETDEWEB)

Sreenivasa R.P.; Tarwade, S.J.; Sarma, K.S.R.

1980-09-01

Only certain marine bacteria capable of digesting the special type of polysaccharide - agar and alginic acid can bring about the biodegradation of these substances and utilise them as carbon source to produce the organics which will be utilised by the methane bacteria to produce methane. When bacterial strain was used in conjunction with cowdung as a source of methane bacteria in seaweed digester, production of biogas from seaweed was accelerated. Adding of small amount of Ulva to seaweed digester increased the output of gas. (Refs. 4).

Development of copper bromide laser master oscillator power

Indian Academy of Sciences (India)

2014-02-09

Feb 9, 2014 ... Development of master oscillator power amplifier (MOPA) system of copper bromide laser (CBL) operating at 110 W average power is reported. The spectral distribution of power at green (510.6 nm) and yellow (578.2 nm) components in the output of a copper bromide laser is studied as a function of ...

Screening of Acetic Acid Bacteria from Pineapple Waste for Bacterial Cellulose Production using Sago Liquid Waste

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Nur Arfa Yanti

2017-12-01

Full Text Available Bacterial cellulose is a biopolymer produced by fermentation process with the help of bacteria. It has numerous applications in industrial sector with its characteristic as a biodegradable and nontoxic compound in nature. The potential application of BC is limited by its production costs, because BC is produced from expensive culture media. The use of cheap carbon and nutrient sources such as sago liquid waste is an interesting strategy to overcome this limitation. The objective of this study was to obtain the AAB strain that capable to produce bacterial cellulose from sago liquid waste. Isolation of AAB strains was conducted using CARR media and the screening of BC production was performed on Hestrin-Schramm (HS media with glucose as a carbon source. The strains of AAB then were evaluated for their cellulose-producing capability using sago liquid waste as a substrate. Thirteen strains of AAB producing BC were isolated from pineapple waste (pineapple core and peel and seven of them were capable to produce BC using sago liquid waste substrate. One of the AAB strains produced a relatively high BC, i.e. isolate LKN6. The result of morphological and biochemical test was proven that the bacteria was Acetobacter xylinum. The result of this study showed that A. xylinum LKN6 can produce a high yield of BC, therefore this strain is potentially useful for its utilization as a starter in bacterial cellulose production. 

Compatible bacterial mixture, tolerant to desiccation, improves maize plant growth.

Science.gov (United States)

Molina-Romero, Dalia; Baez, Antonino; Quintero-Hernández, Verónica; Castañeda-Lucio, Miguel; Fuentes-Ramírez, Luis Ernesto; Bustillos-Cristales, María Del Rocío; Rodríguez-Andrade, Osvaldo; Morales-García, Yolanda Elizabeth; Munive, Antonio; Muñoz-Rojas, Jesús

2017-01-01

Plant growth-promoting rhizobacteria (PGPR) increase plant growth and crop productivity. The inoculation of plants with a bacterial mixture (consortium) apparently provides greater benefits to plant growth than inoculation with a single bacterial strain. In the present work, a bacterial consortium was formulated containing four compatible and desiccation-tolerant strains with potential as PGPR. The formulation had one moderately (Pseudomonas putida KT2440) and three highly desiccation-tolerant (Sphingomonas sp. OF178, Azospirillum brasilense Sp7 and Acinetobacter sp. EMM02) strains. The four bacterial strains were able to adhere to seeds and colonize the rhizosphere of plants when applied in both mono-inoculation and multi-inoculation treatments, showing that they can also coexist without antagonistic effects in association with plants. The effects of the bacterial consortium on the growth of blue maize were evaluated. Seeds inoculated with either individual bacterial strains or the bacterial consortium were subjected to two experimental conditions before sowing: normal hydration or desiccation. In general, inoculation with the bacterial consortium increased the shoot and root dry weight, plant height and plant diameter compared to the non-inoculated control or mono-inoculation treatments. The bacterial consortium formulated in this work had greater benefits for blue maize plants even when the inoculated seeds underwent desiccation stress before germination, making this formulation attractive for future field applications.

Compatible bacterial mixture, tolerant to desiccation, improves maize plant growth.

Directory of Open Access Journals (Sweden)

Dalia Molina-Romero

Full Text Available Plant growth-promoting rhizobacteria (PGPR increase plant growth and crop productivity. The inoculation of plants with a bacterial mixture (consortium apparently provides greater benefits to plant growth than inoculation with a single bacterial strain. In the present work, a bacterial consortium was formulated containing four compatible and desiccation-tolerant strains with potential as PGPR. The formulation had one moderately (Pseudomonas putida KT2440 and three highly desiccation-tolerant (Sphingomonas sp. OF178, Azospirillum brasilense Sp7 and Acinetobacter sp. EMM02 strains. The four bacterial strains were able to adhere to seeds and colonize the rhizosphere of plants when applied in both mono-inoculation and multi-inoculation treatments, showing that they can also coexist without antagonistic effects in association with plants. The effects of the bacterial consortium on the growth of blue maize were evaluated. Seeds inoculated with either individual bacterial strains or the bacterial consortium were subjected to two experimental conditions before sowing: normal hydration or desiccation. In general, inoculation with the bacterial consortium increased the shoot and root dry weight, plant height and plant diameter compared to the non-inoculated control or mono-inoculation treatments. The bacterial consortium formulated in this work had greater benefits for blue maize plants even when the inoculated seeds underwent desiccation stress before germination, making this formulation attractive for future field applications.

Fluoride, bromide and iodide in the Arabian Sea

Digital Repository Service at National Institute of Oceanography (India)

DeSouza, F.P.

Fluoride concentrations varying from 1.32 mg/l at the surface to 1.37 mg/l at depth showed an average of 1.35 + or - 0.004 mg/l with F/Cl of (6.65 + - 0.07) x 10/5. Average bromide was 70 mg/l with Br/Cl of 0.00347. Bromide was found to bear a...

Cytokine responses in primary chicken embryo intestinal cells infected with Campylobacter jejuni strains of human and chicken origin and the expression of bacterial virulence-associated genes

DEFF Research Database (Denmark)

Li, Yiping; Ingmer, Hanne; Madsen, Mogens

2008-01-01

of the bacterial genes. We have investigated the invasiveness of primary chicken embryo intestinal cells (CEICs) by C. jejuni strains of human and chicken origins and the production of pro-inflammatory cytokines as well as the expression of the bacterial virulence-associated genes during co-cultivation. Results C......-free media from another co-cultivation experiment also increased the expression of the virulence-associated genes in the C. jejuni chicken isolate, indicating that the expression of bacterial genes is regulated by component(s) secreted upon co-cultivation of bacteria and CEICs. Conclusion We show that under...... in vitro culture condition C. jejuni strains of both human and chicken origins can invade avian host cells with a pro-inflammatory response and that the virulence-associated genes of C. jejuni may play a role in this process....

Alkene- and alkyne- substituted methylimidazolium bromides: structural effects and Physical properties (Postprint)

National Research Council Canada - National Science Library

Schneider, Stefan; Drake, Gregory; Hall, Leslie; Hawkiins, Tommy; Rosander, Michael; Smith, Dennis

2007-01-01

.... X-ray structures of 1-(2-butynyl)-3-methylimidazolium bromide, 1-propargyl-3-methylimidazolium bromide as well as the X-ray structure of 1-allyl-3- methylimidazolium bromide which was previously identified as a room temperature ionic...

Alkene- and Alkyne- Substituted Methylimidazolium Bromides: Structural Effects and Physical properties (Preprint)

National Research Council Canada - National Science Library

Schneider, Stefan; Drake, Gregory; Hall, Leslie; Hawkiins, Tommy; Rosander, Michael; Smith, Dennis

2007-01-01

.... X-ray structures of 1-(2-butynyl)-3-methylimidazolium bromide, 1-propargyl-3-methylimidazolium bromide as well as the X-ray structure of 1-allyl-3- methylimidazolium bromide which was previously identified as a room temperature ionic...

Development of a novel artificial medium based on utilization of algal photosynthetic metabolites by symbiotic heterotrophs.

Science.gov (United States)

Watanabe, K; Imase, M; Aoyagi, H; Ohmura, N; Saiki, H; Tanaka, H

2008-09-01

(i) Quantitative and qualitative analyses of photosynthetic metabolites of Chlorella sorokiniana and elucidation of the mechanism of their utilization by algal symbionts. (ii) Development of artificial medium that imitates photoautotroph-heterotroph interaction and investigation of its suitability for isolation of novel microbes from the environment. Various components, including free dissolved carbohydrates, nitrogenous compounds and vitamin, were detected and together contributed 11.1% (as carbon content) of the total photosynthetic metabolites in the medium. Utilization of these photosynthetic metabolites in algal culture broth by algal symbionts was studied. Many symbionts showed specific utilization patterns. A novel artificial extracellular released organic carbon medium, which imitated the nutritional conditions surrounding algae, was developed based on the pattern of utilization of the algal metabolites by the symbiotic heterotrophs. About 42.9% of the isolates were closely related to photoautotrophic-dependent and oligotrophic bacteria. With the novel artificial medium, it was possible to selectively isolate some bacterial strains. Synthetic bacterial growth medium is an important and basic tool for bacterial isolation from environmental samples. The current study shows that preferential separation of typical bacterial subset can be achieved by using artificial medium that mimics photosynthetic metabolites.

Bromide space, total body water, and sick cell syndrome

International Nuclear Information System (INIS)

Schober, O.; Hundeshagen, H.; Lehr, L.

1982-01-01

Displacements of the bromide space (Br-82-C, as a marker for the extracellular fluid compartment) are caused by an enhanced anatomical space and/or increased permeability of cells to bromide. The ratio Br-82-C: total body water (TBW) was evaluated to be 0.83 +- 0.17 in critically ill patients (n = 38) compared with the normal value of 0.46 +- 0.04 (n = 10). Because of normal TBW in critically ill patients (TBW = 505 +- 68 ml/kg), an increased bromide penetration into cells seems to be responsible for the enlarged ratio Br-82-C: TBW. Taking into consideration measurements in patients with malabsorption (Br-82-C: TBW = 0.56 +- 0.13; n = 13) and carcinoma of the rectum and colon (Br-82-C: TBW = 0.66 +- 0.24; n = 18) we think that the bromide space is a good measurement of the effective extracellular water. (orig.)

[Isolation, identification and characterization of a diethylstilbestrol-degrading bacterial strain Serratia sp].

Science.gov (United States)

Xu, Ran-Fang; Sun, Min-Xia; Liu, Juan; Wang, Hong; Li, Xin; Zhu, Xue-Zhu; Ling, Wan-Ting

2014-08-01

Utilizing the diethylstilbestrol (DES)-degrading bacteria to biodegrade DES is a most reliable technique for cleanup of DES pollutants from the environment. However, little information is available heretofore on the isolation of DES-degrading bacteria and their DES removal performance in the environment. A novel bacterium capable of degrading DES was isolated from the activated sludge of a wastewater treatment plant. According to its morphology, physiochemical characteristics, and 16S rDNA sequence analysis, this strain was identified as Serratia sp.. The strain was an aerobic bacterium, and it could degrade 68.3% of DES (50 mg x L(-1)) after culturing for 7 days at 30 degrees C, 150 r x min(-1) in shaking flasks. The optimal conditions for DES biodegradation by the obtained strain were 30 degrees C, 40-60 mg x L(-1) DES, pH 7.0, 5% of inoculation volume, 0 g x L(-1) of added NaCl, and 10 mL of liquid medium volume in 100 mL flask.

Antibacterial and Antioxidant Activities of Novel Actinobacteria Strain Isolated from Gulf of Khambhat, Gujarat.

Science.gov (United States)

Dholakiya, Riddhi N; Kumar, Raghawendra; Mishra, Avinash; Mody, Kalpana H; Jha, Bhavanath

2017-01-01

Bacterial secondary metabolites possess a wide range of biologically active compounds including antibacterial and antioxidants. In this study, a Gram-positive novel marine Actinobacteria was isolated from sea sediment which showed 84% 16S rRNA gene sequence (KT588655) similarity with Streptomyces variabilis (EU841661) and designated as Streptomyces variabilis RD-5. The genus Streptomyces is considered as a promising source of bioactive secondary metabolites. The isolated novel bacterial strain was characterized by antibacterial characteristics and antioxidant activities. The BIOLOG based analysis suggested that S. variabilis RD-5 utilized a wide range of substrates compared to the reference strain. The result is further supported by statistical analysis such as AWCD (average well color development), heat-map and PCA (principal component analysis). The whole cell fatty acid profiling showed the dominance of iso/anteiso branched C15-C17 long chain fatty acids. The identified strain S. variabilis RD-5 exhibited a broad spectrum of antibacterial activities for the Gram-negative bacteria ( Escherichia coli NCIM 2065, Shigella boydii NCIM, Klebsiella pneumoniae, Enterobacter cloacae, Pseudomonas sp. NCIM 2200 and Salmonella enteritidis NCIM), and Gram-positive bacteria ( Bacillus subtilis NCIM 2920 and Staphylococcus aureus MTCC 96). Extract of S. variabilis strain RD-5 showed 82.86 and 89% of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and metal chelating activity, respectively, at 5.0 mg/mL. While H 2 O 2 scavenging activity was 74.5% at 0.05 mg/mL concentration. Furthermore, polyketide synthases (PKSs types I and II), an enzyme complex that produces polyketides, the encoding gene(s) detected in the strain RD-5 which may probably involve for the synthesis of antibacterial compound(s). In conclusion, a novel bacterial strain of Actinobacteria , isolated from the unexplored sea sediment of Alang, Gulf of Khambhat (Gujarat), India showed promising

Antibacterial and Antioxidant Activities of Novel Actinobacteria Strain Isolated from Gulf of Khambhat, Gujarat

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Riddhi N. Dholakiya

2017-12-01

Full Text Available Bacterial secondary metabolites possess a wide range of biologically active compounds including antibacterial and antioxidants. In this study, a Gram-positive novel marine Actinobacteria was isolated from sea sediment which showed 84% 16S rRNA gene sequence (KT588655 similarity with Streptomyces variabilis (EU841661 and designated as Streptomyces variabilis RD-5. The genus Streptomyces is considered as a promising source of bioactive secondary metabolites. The isolated novel bacterial strain was characterized by antibacterial characteristics and antioxidant activities. The BIOLOG based analysis suggested that S. variabilis RD-5 utilized a wide range of substrates compared to the reference strain. The result is further supported by statistical analysis such as AWCD (average well color development, heat-map and PCA (principal component analysis. The whole cell fatty acid profiling showed the dominance of iso/anteiso branched C15–C17 long chain fatty acids. The identified strain S. variabilis RD-5 exhibited a broad spectrum of antibacterial activities for the Gram-negative bacteria (Escherichia coli NCIM 2065, Shigella boydii NCIM, Klebsiella pneumoniae, Enterobacter cloacae, Pseudomonas sp. NCIM 2200 and Salmonella enteritidis NCIM, and Gram-positive bacteria (Bacillus subtilis NCIM 2920 and Staphylococcus aureus MTCC 96. Extract of S. variabilis strain RD-5 showed 82.86 and 89% of 2,2-diphenyl-1-picrylhydrazyl (DPPH free radical scavenging and metal chelating activity, respectively, at 5.0 mg/mL. While H2O2 scavenging activity was 74.5% at 0.05 mg/mL concentration. Furthermore, polyketide synthases (PKSs types I and II, an enzyme complex that produces polyketides, the encoding gene(s detected in the strain RD-5 which may probably involve for the synthesis of antibacterial compound(s. In conclusion, a novel bacterial strain of Actinobacteria, isolated from the unexplored sea sediment of Alang, Gulf of Khambhat (Gujarat, India showed promising

Antibacterial and Antioxidant Activities of Novel Actinobacteria Strain Isolated from Gulf of Khambhat, Gujarat

Science.gov (United States)

Dholakiya, Riddhi N.; Kumar, Raghawendra; Mishra, Avinash; Mody, Kalpana H.; Jha, Bhavanath

2017-01-01

Bacterial secondary metabolites possess a wide range of biologically active compounds including antibacterial and antioxidants. In this study, a Gram-positive novel marine Actinobacteria was isolated from sea sediment which showed 84% 16S rRNA gene sequence (KT588655) similarity with Streptomyces variabilis (EU841661) and designated as Streptomyces variabilis RD-5. The genus Streptomyces is considered as a promising source of bioactive secondary metabolites. The isolated novel bacterial strain was characterized by antibacterial characteristics and antioxidant activities. The BIOLOG based analysis suggested that S. variabilis RD-5 utilized a wide range of substrates compared to the reference strain. The result is further supported by statistical analysis such as AWCD (average well color development), heat-map and PCA (principal component analysis). The whole cell fatty acid profiling showed the dominance of iso/anteiso branched C15–C17 long chain fatty acids. The identified strain S. variabilis RD-5 exhibited a broad spectrum of antibacterial activities for the Gram-negative bacteria (Escherichia coli NCIM 2065, Shigella boydii NCIM, Klebsiella pneumoniae, Enterobacter cloacae, Pseudomonas sp. NCIM 2200 and Salmonella enteritidis NCIM), and Gram-positive bacteria (Bacillus subtilis NCIM 2920 and Staphylococcus aureus MTCC 96). Extract of S. variabilis strain RD-5 showed 82.86 and 89% of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and metal chelating activity, respectively, at 5.0 mg/mL. While H2O2 scavenging activity was 74.5% at 0.05 mg/mL concentration. Furthermore, polyketide synthases (PKSs types I and II), an enzyme complex that produces polyketides, the encoding gene(s) detected in the strain RD-5 which may probably involve for the synthesis of antibacterial compound(s). In conclusion, a novel bacterial strain of Actinobacteria, isolated from the unexplored sea sediment of Alang, Gulf of Khambhat (Gujarat), India showed promising

Enhancement of the potential to utilize octopine in the nonfluorescent Pseudomonas sp. strain 92

International Nuclear Information System (INIS)

Gill, S.S.; Boivin, R.; Dion, P.

1991-01-01

The nonfluorescent Pseudomonas sp. strain 92 requires the presence of a supplementary carbon source for growth on octopine, whereas the spontaneous mutant RB100 has acquired the capacity to utilize this opine as the sole carbon and nitrogen source. Insertional mutagenesis of RB100 with transposon Tn5 generated mutants which were unable to grow on octopine and others which grew slowly on this substrate. Both types of mutants yielded revertants that had regained the ability to utilize octopine. Some of the revertants had lost the transposon, whereas in others the transposon was retained but with rearrangements of the insertion site. Genes of octopine catabolism from strain 92 were cloned on a cosmid vector to generate pK3. The clone pK3 conferred the ability to utilize octopine as the sole carbon and nitrogen source on the host Pseudomonas putida KT2440. Although they conferred an equivalent growth phenotype, the mutant genes carried by RB100 and the cloned genes on pK3 differed in their regulation. Utilization of [ 14 C]octopine was inducible by octopine in RB100 and was constitutive in KT2440(pK3)

The Opportunistic Pathogen Serratia marcescens Utilizes Type VI Secretion To Target Bacterial Competitors ▿†

Science.gov (United States)

Murdoch, Sarah L.; Trunk, Katharina; English, Grant; Fritsch, Maximilian J.; Pourkarimi, Ehsan; Coulthurst, Sarah J.

2011-01-01

The type VI secretion system (T6SS) is the most recently described and least understood of the protein secretion systems of Gram-negative bacteria. It is widely distributed and has been implicated in the virulence of various pathogens, but its mechanism and exact mode of action remain to be defined. Additionally there have been several very recent reports that some T6SSs can target bacteria rather than eukaryotic cells. Serratia marcescens is an opportunistic enteric pathogen, a class of bacteria responsible for a significant proportion of hospital-acquired infections. We describe the identification of a functional T6SS in S. marcescens strain Db10, the first report of type VI secretion by an opportunist enteric bacterium. The T6SS of S. marcescens Db10 is active, with secretion of Hcp to the culture medium readily detected, and is expressed constitutively under normal growth conditions from a large transcriptional unit. Expression of the T6SS genes did not appear to be dependent on the integrity of the T6SS. The S. marcescens Db10 T6SS is not required for virulence in three nonmammalian virulence models. It does, however, exhibit dramatic antibacterial killing activity against several other bacterial species and is required for S. marcescens to persist in a mixed culture with another opportunist pathogen, Enterobacter cloacae. Importantly, this antibacterial killing activity is highly strain specific, with the S. marcescens Db10 T6SS being highly effective against another strain of S. marcescens with a very similar and active T6SS. We conclude that type VI secretion plays a crucial role in the competitiveness, and thus indirectly the virulence, of S. marcescens and other opportunistic bacterial pathogens. PMID:21890705

Conduction bands and invariant energy gaps in alkali bromides

NARCIS (Netherlands)

Boer, P.K. de; Groot, R.A. de

1998-01-01

Electronic structure calculations of the alkali bromides LiBr, NaBr, KBr, RbBr and CsBr are reported. It is shown that the conduction band has primarily bromine character. The size of the band gaps of bromides and alkali halides in general is reinterpreted.

On-line production of [11C]cyanogen bromide

International Nuclear Information System (INIS)

Westerberg, G.; Laangstroem, B.

1997-01-01

The electrophilic labelling precursor [ 11 C]cyanogen bromide was produced in 95% radiochemical yield (decay-corrected) from hydrogen [ 11 C]cyanide within 3 min from the end of bombardment using a simple and convenient solid-phase on-line procedure. The [ 11 C]cyanogen bromide has been used in the synthesis of a number of labelled compounds for use in positron emission tomography. (author)

Colonization of Vitis vinifera by a green fluorescence protein-labeled, gfp-marked strain of Xylophilus ampelinus, the causal agent of bacterial necrosis of grapevine.

Science.gov (United States)

Grall, Sophie; Manceau, Charles

2003-04-01

The dynamics of Xylophilus ampelinus were studied in Vitis vinifera cv. Ugni blanc using gfp-marked bacterial strains to evaluate the relative importance of epiphytic and endophytic phases of plant colonization in disease development. Currently, bacterial necrosis of grapevine is of economic importance in vineyards in three regions in France: the Cognac, Armagnac, and Die areas. This disease is responsible for progressive destruction of vine shoots, leading to their death. We constructed gfp-marked strains of the CFBP2098 strain of X. ampelinus for histological studies. We studied the colonization of young plants of V. vinifera cv. Ugni blanc by X. ampelinus after three types of artificial contamination in a growth chamber and in a greenhouse. (i) After wounding of the stem and inoculation, the bacteria progressed down to the crown through the xylem vessels, where they organized into biofilms. (ii) When the bacteria were forced into woody cuttings, they rarely colonized the emerging plantlets. Xylem vessels could play a key role in the multiplication and conservation of the bacteria, rather than being a route for plant colonization. (iii) When bacterial suspensions were sprayed onto the plants, bacteria progressed in two directions: both in emerging organs and down to the crown, thus displaying the importance of epiphytic colonization in disease development.

Increasing antibiotic resistance in preservative-tolerant bacterial strains isolated from cosmetic products.

Science.gov (United States)

Orús, Pilar; Gomez-Perez, Laura; Leranoz, Sonia; Berlanga, Mercedes

2015-03-01

To ensure the microbiological quality, consumer safety and organoleptic properties of cosmetic products, manufacturers need to comply with defined standards using several preservatives and disinfectants. A drawback regarding the use of these preservatives is the possibility of generating cross-insusceptibility to other disinfectants or preservatives, as well as cross resistance to antibiotics. Therefore, the objective of this study was to understand the adaptive mechanisms of Enterobacter gergoviae, Pseudomonas putida and Burkholderia cepacia that are involved in recurrent contamination in cosmetic products containing preservatives. Diminished susceptibility to formaldehyde-donors was detected in isolates but not to other preservatives commonly used in the cosmetics industry, although increasing resistance to different antibiotics (β-lactams, quinolones, rifampicin, and tetracycline) was demonstrated in these strains when compared with the wild-type strain. The outer membrane protein modifications and efflux mechanism activities responsible for the resistance trait were evaluated. The development of antibiotic-resistant microorganisms due to the selective pressure from preservatives included in cosmetic products could be a risk for the emergence and spread of bacterial resistance in the environment. Nevertheless, the large contribution of disinfection and preservation cannot be denied in cosmetic products. Copyright© by the Spanish Society for Microbiology and Institute for Catalan Studies.

Ultraviolet radiation response of two heterotropy Antarctic marine bacterial

International Nuclear Information System (INIS)

Hernandez, Edgardo A.; Ferreyra, Gustavo A.; Mac Cormack, Walter P.

2004-01-01

Two Antarctic marine bacterial strains, were exposed to different irradiance of ultraviolet (UV) solar radiation using several experimental protocols and interferential filters. Results showed that both, UV-A and UV-B radiation produce deleterious effects on two tested bacterial strains. The mortality values under UVB treatments were higher than those observed under UVA treatments. UVvi strain proved to be more resistant to UV radiation than the UVps strain. (author) [es

Resistance and Inactivation Kinetics of Bacterial Strains Isolated from the Non-Chlorinated and Chlorinated Effluents of a WWTP

Directory of Open Access Journals (Sweden)

Claudia Coronel-Olivares

2013-08-01

Full Text Available The microbiological quality of water from a wastewater treatment plant that uses sodium hypochlorite as a disinfectant was assessed. Mesophilic aerobic bacteria were not removed efficiently. This fact allowed for the isolation of several bacterial strains from the effluents. Molecular identification indicated that the strains were related to Aeromonas hydrophila, Escherichia coli (three strains, Enterobacter cloacae, Kluyvera cryocrescens (three strains, Kluyvera intermedia, Citrobacter freundii (two strains, Bacillus sp. and Enterobacter sp. The first five strains, which were isolated from the non-chlorinated effluent, were used to test resistance to chlorine disinfection using three sets of variables: disinfectant concentration (8, 20 and 30 mg·L−1, contact time (0, 15 and 30 min and water temperature (20, 25 and 30 °C. The results demonstrated that the strains have independent responses to experimental conditions and that the most efficient treatment was an 8 mg·L−1 dose of disinfectant at a temperature of 20 °C for 30 min. The other eight strains, which were isolated from the chlorinated effluent, were used to analyze inactivation kinetics using the disinfectant at a dose of 15 mg·L−1 with various retention times (0, 10, 20, 30, 60 and 90 min. The results indicated that during the inactivation process, there was no relationship between removal percentage and retention time and that the strains have no common response to the treatments.

Probiotic features of Lactobacillus plantarum mutant strains.

Science.gov (United States)

Bove, Pasquale; Gallone, Anna; Russo, Pasquale; Capozzi, Vittorio; Albenzio, Marzia; Spano, Giuseppe; Fiocco, Daniela

2012-10-01

In this study, the probiotic potential of Lactobacillus plantarum wild-type and derivative mutant strains was investigated. Bacterial survival was evaluated in an in vitro system, simulating the transit along the human oro-gastro-intestinal tract. Interaction with human gut epithelial cells was studied by assessing bacterial adhesive ability to Caco-2 cells and induction of genes involved in innate immunity. L. plantarum strains were resistant to the combined stress at the various steps of the simulated gastrointestinal tract. Major decreases in the viability of L. plantarum cells were observed mainly under drastic acidic conditions (pH ≤ 2.0) of the gastric compartment. Abiotic stresses associated to small intestine poorly affected bacterial viability. All the bacterial strains significantly adhered to Caco-2 cells, with the ΔctsR mutant strain exhibiting the highest adhesion. Induction of immune-related genes resulted higher upon incubation with heat-inactivated bacteria rather than with live ones. For specific genes, a differential transcriptional pattern was observed upon stimulation with different L. plantarum strains, evidencing a possible role of the knocked out bacterial genes in the modulation of host cell response. In particular, cells from Δhsp18.55 and ΔftsH mutants strongly triggered immune defence genes. Our study highlights the relevance of microbial genetic background in host-probiotic interaction and might contribute to identify candidate bacterial genes and molecules involved in probiosis.

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

NARCIS (Netherlands)

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

2014-01-01

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

Antibiotics promote aggregation within aquatic bacterial communities

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Gianluca eCorno

2014-07-01

Full Text Available The release of antibiotics (AB into the environment poses several threats for human health due to potential development of ABresistant natural bacteria. Even though the use of low-dose antibiotics has been promoted in health care and farming, significant amounts of AB are observed in aquatic environments. Knowledge on the impact of AB on natural bacterial communities is missing both in terms of spread and evolution of resistance mechanisms, and of modifications of community composition and productivity. New approaches are required to study the response of microbial communities rather than individual resistance genes. In this study a chemostat-based experiment with 4 coexisting bacterial strains has been performed to mimicking the response of a freshwater bacterial community to the presence of antibiotics in low and high doses. Bacterial abundance rapidly decreased by 75% in the presence of AB, independently of their concentration, and remained constant until the end of the experiment. The bacterial community was mainly dominated by Aeromonas hydrophila and Brevundimonas intermedia while the other two strains, Micrococcus luteus and Rhodococcus sp. never exceed 10%. Interestingly, the bacterial strains, which were isolated at the end of the experiment, were not AB-resistant, while reassembled communities composed of the 4 strains, isolated from treatments under AB stress, significantly raised their performance (growth rate, abundance in the presence of AB compared to the communities reassembled with strains isolated from the treatment without AB. By investigating the phenotypic adaptations of the communities subjected to the different treatments, we found that the presence of AB significantly increased co-aggregation by 5-6 fold.These results represent the first observation of co-aggregation as a successful strategy of AB resistance based on phenotype in aquatic bacterial communities, and can represent a fundamental step in the understanding of

Molecular approaches for bacterial azoreductases

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Montira Leelakriangsak

2013-12-01

Full Text Available Azo dyes are the dominant types of synthetic dyes, widely used in textiles, foods, leather, printing, tattooing, cosmetics, and pharmaceutical industries. Many microorganisms are able to decolorize azo dyes, and there is increasing interest in biological waste treatment methods. Bacterial azoreductases can cleave azo linkages (-N=N- in azo dyes, forming aromatic amines. This review mainly focuses on employing molecular approaches, including gene manipulation and recombinant strains, to study bacterial azoreductases. The construction of the recombinant protein by cloning and the overexpression of azoreductase is described. The mechanisms and function of bacterial azoreductases can be studied by other molecular techniques discussed in this review, such as RT-PCR, southern blot analysis, western blot analysis, zymography, and muta-genesis in order to understand bacterial azoreductase properties, function and application. In addition, understanding the regulation of azoreductase gene expression will lead to the systematic use of gene manipulation in bacterial strains for new strategies in future waste remediation technologies.

Bacterial Diversity and Bioremediation Potential of the Highly Contaminated Marine Sediments at El-Max District (Egypt, Mediterranean Sea

Directory of Open Access Journals (Sweden)

Ranya A. Amer

2015-01-01

Full Text Available Coastal environments worldwide are threatened by the effects of pollution, a risk particularly high in semienclosed basins like the Mediterranean Sea that is poorly studied from bioremediation potential perspective especially in the Southern coast. Here, we investigated the physical, chemical, and microbiological features of hydrocarbon and heavy metals contaminated sediments collected at El-Max bay (Egypt. Molecular and statistical approaches assessing the structure of the sediment-dwelling bacterial communities showed correlations between the composition of bacterial assemblages and the associated environmental parameters. Fifty strains were isolated on mineral media supplemented by 1% crude oil and identified as a diverse range of hydrocarbon-degrading bacteria involved in different successional stages of biodegradation. We screened the collection for biotechnological potential studying biosurfactant production, biofilm formation, and the capability to utilize different hydrocarbons. Some strains were able to grow on multiple hydrocarbons as unique carbon source and presented biosurfactant-like activities and/or capacity to form biofilm and owned genes involved in different detoxification/degradation processes. El-Max sediments represent a promising reservoir of novel bacterial strains adapted to high hydrocarbon contamination loads. The potential of the strains for exploitation for in situ intervention to combat pollution in coastal areas is discussed.

Bacterial Diversity and Bioremediation Potential of the Highly Contaminated Marine Sediments at El-Max District (Egypt, Mediterranean Sea)

Science.gov (United States)

Amer, Ranya A.; El Gendi, Hamada M.; Goda, Doaa A.; Corsini, Anna; Cavalca, Lucia; Fusi, Marco; Daffonchio, Daniele; Abdel-Fattah, Yasser R.

2015-01-01

Coastal environments worldwide are threatened by the effects of pollution, a risk particularly high in semienclosed basins like the Mediterranean Sea that is poorly studied from bioremediation potential perspective especially in the Southern coast. Here, we investigated the physical, chemical, and microbiological features of hydrocarbon and heavy metals contaminated sediments collected at El-Max bay (Egypt). Molecular and statistical approaches assessing the structure of the sediment-dwelling bacterial communities showed correlations between the composition of bacterial assemblages and the associated environmental parameters. Fifty strains were isolated on mineral media supplemented by 1% crude oil and identified as a diverse range of hydrocarbon-degrading bacteria involved in different successional stages of biodegradation. We screened the collection for biotechnological potential studying biosurfactant production, biofilm formation, and the capability to utilize different hydrocarbons. Some strains were able to grow on multiple hydrocarbons as unique carbon source and presented biosurfactant-like activities and/or capacity to form biofilm and owned genes involved in different detoxification/degradation processes. El-Max sediments represent a promising reservoir of novel bacterial strains adapted to high hydrocarbon contamination loads. The potential of the strains for exploitation for in situ intervention to combat pollution in coastal areas is discussed. PMID:26273661

Draft Genome Sequence of Cupriavidus pauculus Strain KF709, a Biphenyl-Utilizing Bacterium Isolated from Biphenyl-Contaminated Soil

OpenAIRE

Watanabe, Takahito; Yamazoe, Atsushi; Hosoyama, Akira; Fujihara, Hidehiko; Suenaga, Hikaru; Hirose, Jun; Futagami, Taiki; Goto, Masatoshi; Kimura, Nobutada; Furukawa, Kensuke

2015-01-01

We report the draft genome sequence of Cupriavidus pauculus strain KF709, which comprises 6,826,799 bp with 6,272 coding sequences. The strain KF709 utilizes biphenyl and degrades low-chlorinated biphenyls; however, it possesses fewer coding sequences involved in the degradation of aromatic compounds than other strains belonging to the Betaproteobacteria.

Study On Ammonia Accumulation of Cellulose-Utilizing and Nitrogen-Fixing Bacteria Isolated from Various Soils

International Nuclear Information System (INIS)

Soe Myat Thandar; Aung Ko Ko Oo; Weine Nway Nway Oo

2011-12-01

Cellulose-utilizing and nitrogen-fixing bacteria were isolated from various soil. 42 bacterial strains were obtained. Among those stains, 13 strains were screened for nitrogen-fixing activity. Among them, 4 strains coded as CPB1, CMB1, GPB2 and 3LC4 showed the high nitrogen-fixing activity. Different strains produced different amount of ammonium compounds at various incubation periods. CMB1 produced the maximum amount of ammonium 1.2 mg/L NH4+ at 6th day culture but 3LC4, GPB2 and CPB1 produced more amount of NH4+ with 2, 2.5 and 3 mg/L NH4+ respectively at 5th day culture.

Preparation, characterization and antibacterial effects of eco-friendly ...

African Journals Online (AJOL)

Purpose: To synthesize and characterize eco-friendly gold nanorods (Au-NRs) and to assess their effects against two bacterial strains. Methods: Synthesis of eco-friendly gold nanorods was done from an aqueous solution of chloroauric acid and cetyltrimethylammonium bromide by mixing Olea europaea fruit and Acacia ...

Monitoring of water movement in paddy field's soil using a bromide tracer

International Nuclear Information System (INIS)

Asiah Ahmad; Kouichi Yuita

1994-01-01

Water movement in soils at the lower course and the middle course of Sakawa River's paddy field was monitored over an 8 week period using a bromide tracer. The water of soil samples taken one day after bromide application contained high concentrations of bromide at 50 to 60 cm soil depth at lower course. The bromide was concentrated promarily within 20 to 80 cm depth. No downward movement below 80 cm depth was detected six weeks afetr the application. This might indicate the high water table of this area. On the other hand, bromide concentrations were high at 50 cm depth in water of the soils sample taken one day after application from the middle course of Sakawa River plot. However, the concentrations were nearly at background level in all samples taken from the middle course of sakawa River 3 weeks after application. The evidence from bromide's movement shows that water readily penetrate the soils at the middle course of Sakawa River. The downward movement was faster compared to that at lower course

Biodegradation and detoxification of melanoidin from distillery effluent using an aerobic bacterial strain SAG{sub 5} of Alcaligenes faecalis

Energy Technology Data Exchange (ETDEWEB)

Santal, Anita Rani, E-mail: anita.gangotra@gmail.com [Department of Microbiology, Maharshi Dayanand University, Rohtak-124001, Haryana (India); Singh, N.P. [Centre for Biotechnology, Maharshi Dayanand University, Rohtak-124001, Haryana (India); Saharan, Baljeet Singh [Department of Microbiology, Kurukshetra University, Kurukshetra-136119, Haryana (India)

2011-10-15

Highlights: {yields} The Alcaligenes faecalis strain SAG{sub 5} decolorizes 72.6 {+-} 0.56% of melanoidins. {yields} The decolorization was achieved at pH 7.5 and temperature 37 {sup o}C on 5th day. {yields} The distillery effluent after biological treatment is environmentally safe. - Abstract: Distillery effluent retains very dark brown color even after anaerobic treatment due to presence of various water soluble, recalcitrant and coloring compounds mainly melanoidins. In laboratory conditions, melanoidin decolorizing bacteria was isolated and optimized the cultural conditions at various incubation temperatures, pH, carbon sources, nitrogen sources and combined effect of both carbon and nitrogen sources. The optimum decolorization (72.6 {+-} 0.56%) of melanoidins was achieved at pH 7.5 and temperature 37 {sup o}C on 5th day of cultivation. The toxicity evaluation with mung bean (Vigna radiata) revealed that the raw distillery effluent was environmentally highly toxic as compared to biologically treated distillery effluent, which indicated that the effluent after bacterial treatment is environmentally safe. This proves to be novel biological treatment technique for biodegradation and detoxification of melanoidin from distillery effluent using the bacterial strain SAG{sub 5}.

Engineering control of bacterial cellulose production using a genetic toolkit and a new cellulose-producing strain

Science.gov (United States)

Florea, Michael; Hagemann, Henrik; Santosa, Gabriella; Micklem, Chris N.; Spencer-Milnes, Xenia; de Arroyo Garcia, Laura; Paschou, Despoina; Lazenbatt, Christopher; Kong, Deze; Chughtai, Haroon; Jensen, Kirsten; Freemont, Paul S.; Kitney, Richard; Reeve, Benjamin; Ellis, Tom

2016-01-01

Bacterial cellulose is a strong and ultrapure form of cellulose produced naturally by several species of the Acetobacteraceae. Its high strength, purity, and biocompatibility make it of great interest to materials science; however, precise control of its biosynthesis has remained a challenge for biotechnology. Here we isolate a strain of Komagataeibacter rhaeticus (K. rhaeticus iGEM) that can produce cellulose at high yields, grow in low-nitrogen conditions, and is highly resistant to toxic chemicals. We achieved external control over its bacterial cellulose production through development of a modular genetic toolkit that enables rational reprogramming of the cell. To further its use as an organism for biotechnology, we sequenced its genome and demonstrate genetic circuits that enable functionalization and patterning of heterologous gene expression within the cellulose matrix. This work lays the foundations for using genetic engineering to produce cellulose-based materials, with numerous applications in basic science, materials engineering, and biotechnology. PMID:27247386

Construction of a full-length infectious bacterial artificial chromosome clone of duck enteritis virus vaccine strain

Science.gov (United States)

2013-01-01

Background Duck enteritis virus (DEV) is the causative agent of duck viral enteritis, which causes an acute, contagious and lethal disease of many species of waterfowl within the order Anseriformes. In recent years, two laboratories have reported on the successful construction of DEV infectious clones in viral vectors to express exogenous genes. The clones obtained were either created with deletion of viral genes and based on highly virulent strains or were constructed using a traditional overlapping fosmid DNA system. Here, we report the construction of a full-length infectious clone of DEV vaccine strain that was cloned into a bacterial artificial chromosome (BAC). Methods A mini-F vector as a BAC that allows the maintenance of large circular DNA in E. coli was introduced into the intergenic region between UL15B and UL18 of a DEV vaccine strain by homologous recombination in chicken embryoblasts (CEFs). Then, the full-length DEV clone pDEV-vac was obtained by electroporating circular viral replication intermediates containing the mini-F sequence into E. coli DH10B and identified by enzyme digestion and sequencing. The infectivity of the pDEV-vac was validated by DEV reconstitution from CEFs transfected with pDEV-vac. The reconstructed virus without mini-F vector sequence was also rescued by co-transfecting the Cre recombinase expression plasmid pCAGGS-NLS/Cre and pDEV-vac into CEF cultures. Finally, the in vitro growth properties and immunoprotection capacity in ducks of the reconstructed viruses were also determined and compared with the parental virus. Results The full genome of the DEV vaccine strain was successfully cloned into the BAC, and this BAC clone was infectious. The in vitro growth properties of these reconstructions were very similar to parental DEV, and ducks immunized with these viruses acquired protection against virulent DEV challenge. Conclusions DEV vaccine virus was cloned as an infectious bacterial artificial chromosome maintaining full

Colonization of Vitis vinifera by a Green Fluorescence Protein-Labeled, gfp-Marked Strain of Xylophilus ampelinus, the Causal Agent of Bacterial Necrosis of Grapevine

OpenAIRE

Grall, Sophie; Manceau, Charles

2003-01-01

The dynamics of Xylophilus ampelinus were studied in Vitis vinifera cv. Ugni blanc using gfp-marked bacterial strains to evaluate the relative importance of epiphytic and endophytic phases of plant colonization in disease development. Currently, bacterial necrosis of grapevine is of economic importance in vineyards in three regions in France: the Cognac, Armagnac, and Die areas. This disease is responsible for progressive destruction of vine shoots, leading to their death. We constructed gfp-...

Effectiveness of Origanum vulgare L. and Origanum majorana L. essential oils in inhibiting the growth of bacterial strains isolated from the patients with conjunctivitis

OpenAIRE

Oliveira, Jana Luíza Toscano Mendes de; Diniz, Margareth de Fátima Melo; Lima, Edeltrudes de Oliveira; Souza, Evandro Leite de; Trajano, Vinícius Nogueira; Santos, Bernadete Helena Cavalcante

2009-01-01

This study aimed to evaluate the antibacterial activity of Origanum vulgare L. and O. majorana L. essential oils on Staphylococcus aureus, S. coagulase negative, Enterobacter spp., Proteus spp., Acinetobacter spp., Klebsiella spp. isolated from the patients with conjunctivitis. The results showed a prominent inhibitory effect of both the essential oils on all the bacterial strains, noted by the large bacterial growth inhibition zones (15-32mm). The Minimum Inhibitory Concentrations (MIC) valu...

Draft Genome Sequence of Cupriavidus pauculus Strain KF709, a Biphenyl-Utilizing Bacterium Isolated from Biphenyl-Contaminated Soil.

Science.gov (United States)

Watanabe, Takahito; Yamazoe, Atsushi; Hosoyama, Akira; Fujihara, Hidehiko; Suenaga, Hikaru; Hirose, Jun; Futagami, Taiki; Goto, Masatoshi; Kimura, Nobutada; Furukawa, Kensuke

2015-03-26

We report the draft genome sequence of Cupriavidus pauculus strain KF709, which comprises 6,826,799 bp with 6,272 coding sequences. The strain KF709 utilizes biphenyl and degrades low-chlorinated biphenyls; however, it possesses fewer coding sequences involved in the degradation of aromatic compounds than other strains belonging to the Betaproteobacteria. Copyright © 2015 Watanabe et al.

Evolution of Bacterial Global Modulators: Role of a Novel H-NS Paralogue in the Enteroaggregative Escherichia coli Strain 042.

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Prieto, A; Bernabeu, M; Aznar, S; Ruiz-Cruz, S; Bravo, A; Queiroz, M H; Juárez, A

2018-01-01

Bacterial genomes sometimes contain genes that code for homologues of global regulators, the function of which is unclear. In members of the family Enterobacteriaceae , cells express the global regulator H-NS and its paralogue StpA. In Escherichia coli , out of providing a molecular backup for H-NS, the role of StpA is poorly characterized. The enteroaggregative E. coli strain 042 carries, in addition to the hns and stpA genes, a third gene encoding an hns paralogue ( hns2 ). We present in this paper information about its biological function. Transcriptomic analysis has shown that the H-NS2 protein targets a subset of the genes targeted by H-NS. Genes targeted by H-NS2 correspond mainly with horizontally transferred (HGT) genes and are also targeted by the Hha protein, a fine-tuner of H-NS activity. Compared with H-NS, H-NS2 expression levels are lower. In addition, H-NS2 expression exhibits specific features: it is sensitive to the growth temperature and to the nature of the culture medium. This novel H-NS paralogue is widespread within the Enterobacteriaceae . IMPORTANCE Global regulators such as H-NS play key relevant roles enabling bacterial cells to adapt to a changing environment. H-NS modulates both core and horizontally transferred (HGT) genes, but the mechanism by which H-NS can differentially regulate these genes remains to be elucidated. There are several instances of bacterial cells carrying genes that encode homologues of the global regulators. The question is what the roles of these proteins are. We noticed that the enteroaggregative E. coli strain 042 carries a new hitherto uncharacterized copy of the hns gene. We decided to investigate why this pathogenic E. coli strain requires an extra H-NS paralogue, termed H-NS2. In our work, we show that H-NS2 displays specific expression and regulatory properties. H-NS2 targets a subset of H-NS-specific genes and may help to differentially modulate core and HGT genes by the H-NS cellular pool.

Bacterial Cellulose Production from Industrial Waste and by-Product Streams.

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Tsouko, Erminda; Kourmentza, Constantina; Ladakis, Dimitrios; Kopsahelis, Nikolaos; Mandala, Ioanna; Papanikolaou, Seraphim; Paloukis, Fotis; Alves, Vitor; Koutinas, Apostolis

2015-07-01

The utilization of fermentation media derived from waste and by-product streams from biodiesel and confectionery industries could lead to highly efficient production of bacterial cellulose. Batch fermentations with the bacterial strain Komagataeibacter sucrofermentans DSM (Deutsche Sammlung von Mikroorganismen) 15973 were initially carried out in synthetic media using commercial sugars and crude glycerol. The highest bacterial cellulose concentration was achieved when crude glycerol (3.2 g/L) and commercial sucrose (4.9 g/L) were used. The combination of crude glycerol and sunflower meal hydrolysates as the sole fermentation media resulted in bacterial cellulose production of 13.3 g/L. Similar results (13 g/L) were obtained when flour-rich hydrolysates produced from confectionery industry waste streams were used. The properties of bacterial celluloses developed when different fermentation media were used showed water holding capacities of 102-138 g · water/g · dry bacterial cellulose, viscosities of 4.7-9.3 dL/g, degree of polymerization of 1889.1-2672.8, stress at break of 72.3-139.5 MPa and Young's modulus of 0.97-1.64 GPa. This study demonstrated that by-product streams from the biodiesel industry and waste streams from confectionery industries could be used as the sole sources of nutrients for the production of bacterial cellulose with similar properties as those produced with commercial sources of nutrients.

Whole genome sequencing options for bacterial strain typing and epidemiologic analysis based on single nucleotide polymorphism versus gene-by-gene-based approaches.

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Schürch, A C; Arredondo-Alonso, S; Willems, R J L; Goering, R V

2018-04-01

Whole genome sequence (WGS)-based strain typing finds increasing use in the epidemiologic analysis of bacterial pathogens in both public health as well as more localized infection control settings. This minireview describes methodologic approaches that have been explored for WGS-based epidemiologic analysis and considers the challenges and pitfalls of data interpretation. Personal collection of relevant publications. When applying WGS to study the molecular epidemiology of bacterial pathogens, genomic variability between strains is translated into measures of distance by determining single nucleotide polymorphisms in core genome alignments or by indexing allelic variation in hundreds to thousands of core genes, assigning types to unique allelic profiles. Interpreting isolate relatedness from these distances is highly organism specific, and attempts to establish species-specific cutoffs are unlikely to be generally applicable. In cases where single nucleotide polymorphism or core gene typing do not provide the resolution necessary for accurate assessment of the epidemiology of bacterial pathogens, inclusion of accessory gene or plasmid sequences may provide the additional required discrimination. As with all epidemiologic analysis, realizing the full potential of the revolutionary advances in WGS-based approaches requires understanding and dealing with issues related to the fundamental steps of data generation and interpretation. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Analysis of infiltration through mill tailings using a bromide tracer

International Nuclear Information System (INIS)

Lewis, G.J.; Stephens, D.B.

1985-01-01

Infiltration of precipitation into tailings impoundments as a means of recharge to underlying materials is often considered insignificant, particularly in arid and semi-arid environments. A series of experiments was performed to investigate the behavior of infiltrated precipitation into tailing soils, by the use of a bromide tracer. A bromide tracer was applied to the surface of columns driven into the tailings to monitor downward advancement of tracer-laden water. Controlled laboratory experiments on the behavior of the bromide tracer under varying precipitation events and initial soil moisture contents were also conducted. Results indicate that a definite downward migration of infiltrated precipitation occurs, particularly with large magnitude precipitation events, and that, eventually, some fraction of the infiltrated precipitation may continue downward below the zone affected by evaporation. The use of an artificially applied bromide tracer to monitor depth of infiltration of precipitation is a simple, safe technique that can provide valuable information for long-term tailings management strategies at low cost

Bacterial community affects toxin production by Gymnodinium catenatum.

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Maria E Albinsson

Full Text Available The paralytic shellfish toxin (PST-producing dinoflagellate Gymnodinium catenatum grows in association with a complex marine bacterial community that is both essential for growth and can alter culture growth dynamics. Using a bacterial community replacement approach, we examined the intracellular PST content, production rate, and profile of G. catenatum cultures grown with bacterial communities of differing complexity and composition. Clonal offspring were established from surface-sterilized resting cysts (produced by sexual crosses of strain GCDE06 and strain GCLV01 and grown with: 1 complex bacterial communities derived from each of the two parent cultures; 2 simplified bacterial communities composed of the G. catenatum-associated bacteria Marinobacter sp. strain DG879 or Alcanivorax sp. strain DG881; 3 a complex bacterial community associated with an untreated, unsterilized sexual cross of the parents. Toxin content (STX-equivalent per cell of clonal offspring (134-197 fmol STX cell(-1 was similar to the parent cultures (169-206 fmol STX cell(-1, however cultures grown with single bacterial types contained less toxin (134-146 fmol STX cell(-1 than offspring or parent cultures grown with more complex mixed bacterial communities (152-176 fmol STX cell(-1. Specific toxin production rate (fmol STX day(-1 was strongly correlated with culture growth rate. Net toxin production rate (fmol STX cell(-1 day(-1 did not differ among treatments, however, mean net toxin production rate of offspring was 8-fold lower than the parent cultures, suggesting that completion of the sexual lifecycle in laboratory cultures leads to reduced toxin production. The PST profiles of offspring cultures were most similar to parent GCDE06 with the exception of cultures grown with Marinobacter sp. DG879 which produced higher proportions of dcGTX2+3 and GC1+2, and lower proportions of C1+2 and C3+4. Our data demonstrate that the bacterial community can alter intracellular STX

Bacterial community affects toxin production by Gymnodinium catenatum.

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Albinsson, Maria E; Negri, Andrew P; Blackburn, Susan I; Bolch, Christopher J S

2014-01-01

The paralytic shellfish toxin (PST)-producing dinoflagellate Gymnodinium catenatum grows in association with a complex marine bacterial community that is both essential for growth and can alter culture growth dynamics. Using a bacterial community replacement approach, we examined the intracellular PST content, production rate, and profile of G. catenatum cultures grown with bacterial communities of differing complexity and composition. Clonal offspring were established from surface-sterilized resting cysts (produced by sexual crosses of strain GCDE06 and strain GCLV01) and grown with: 1) complex bacterial communities derived from each of the two parent cultures; 2) simplified bacterial communities composed of the G. catenatum-associated bacteria Marinobacter sp. strain DG879 or Alcanivorax sp. strain DG881; 3) a complex bacterial community associated with an untreated, unsterilized sexual cross of the parents. Toxin content (STX-equivalent per cell) of clonal offspring (134-197 fmol STX cell(-1)) was similar to the parent cultures (169-206 fmol STX cell(-1)), however cultures grown with single bacterial types contained less toxin (134-146 fmol STX cell(-1)) than offspring or parent cultures grown with more complex mixed bacterial communities (152-176 fmol STX cell(-1)). Specific toxin production rate (fmol STX day(-1)) was strongly correlated with culture growth rate. Net toxin production rate (fmol STX cell(-1) day(-1)) did not differ among treatments, however, mean net toxin production rate of offspring was 8-fold lower than the parent cultures, suggesting that completion of the sexual lifecycle in laboratory cultures leads to reduced toxin production. The PST profiles of offspring cultures were most similar to parent GCDE06 with the exception of cultures grown with Marinobacter sp. DG879 which produced higher proportions of dcGTX2+3 and GC1+2, and lower proportions of C1+2 and C3+4. Our data demonstrate that the bacterial community can alter intracellular STX

Engineering Escherichia coli for Biodiesel Production Utilizing a Bacterial Fatty Acid Methyltransferase▿†

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Nawabi, Parwez; Bauer, Stefan; Kyrpides, Nikos; Lykidis, Athanasios

2011-01-01

The production of low-cost biofuels in engineered microorganisms is of great interest due to the continual increase in the world's energy demands. Biodiesel is a renewable fuel that can potentially be produced in microbes cost-effectively. Fatty acid methyl esters (FAMEs) are a common component of biodiesel and can be synthesized from either triacylglycerol or free fatty acids (FFAs). Here we report the identification of a novel bacterial fatty acid methyltransferase (FAMT) that catalyzes the formation of FAMEs and 3-hydroxyl fatty acid methyl esters (3-OH-FAMEs) from the respective free acids and S-adenosylmethionine (AdoMet). FAMT exhibits a higher specificity toward 3-hydroxy free fatty acids (3-OH-FFAs) than FFAs, synthesizing 3-hydroxy fatty acid methyl esters (3-OH-FAMEs) in vivo. We have also identified bacterial members of the fatty acyl-acyl carrier protein (ACP) thioesterase (FAT) enzyme family with distinct acyl chain specificities. These bacterial FATs exhibit increased specificity toward 3-hydroxyacyl-ACP, generating 3-OH-FFAs, which can subsequently be utilized by FAMTs to produce 3-OH-FAMEs. PhaG (3-hydroxyacyl ACP:coenzyme A [CoA] transacylase) constitutes an alternative route to 3-OH-FFA synthesis; the coexpression of PhaG with FAMT led to the highest level of accumulation of 3-OH-FAMEs and FAMEs. The availability of AdoMet, the second substrate for FAMT, is an important factor regulating the amount of methyl esters produced by bacterial cells. Our results indicate that the deletion of the global methionine regulator metJ and the overexpression of methionine adenosyltransferase result in increased methyl ester synthesis. PMID:21926202

Revisiting the Kinetics and Mechanism of Bromate-Bromide Reaction

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Côrtes Carlos Eduardo S.

2001-01-01

Full Text Available The bromate-bromide reaction was investigated in an acidity range not studied yet. The reaction was followed at the Br2/Br3- isosbestic point (lambda = 446 nm. It was observed a first-order behavior for bromate and bromide ions and a second-order behavior for H+ ion that results in the rate law nu = k[BrO3-][Br- ][H+]². This rate law suggests a mechanism involving two successive protonation of bromate followed by the interaction of the intermediate species H2BrO3+ with bromide. These results disagree with the obtained by other authors who observed a second-order behavior for the bromide and first-order for H+, and have proposed intermediate species like H2Br2O3 and HBr2O3-. The second-order for [H+] observed in the range 0.005 <= [H+] <= 2.77 mol L-1 sets down that the pKa of bromic acid, HBrO3, must be lower than -0.5 (T = 25 °C, different from all other values for this pKa proposed in the literature.

Analysis of bacterial strains from contaminated and non ...

African Journals Online (AJOL)

Administrator

2007-05-02

May 2, 2007 ... A total 18 strains were collected from non-contaminated and contaminated environments, and were purified. All purified strains were characterized for Gram reaction and biochemical analysis. Screening for bioplastic production was done by Sudan black staining. Strains isolated from non-contaminated.

Evaluation of different lactic acid bacterial strains for probiotic characteristics

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B. Srinu,

2013-08-01

Full Text Available Objective: The objective of the present study was to collect different Lactic acid bacterial strains from culture collection centers and screen their functional probiotic characteristics such as acid tolerance, bile tolerance, antibacterial activity and antibiotic sensitivity for their commercial use. Materials and Methods: Acid and bile tolerence of selected LAB(Lactic acid bacteria was determined. The antibiotic resistance of Lactobacillus species was assessed using different antibiotic discs on de Mann Rogosa Sharpe broth (MRS agar plates seeded with the test probiotic organism. The antibacterial activity of LAB was assessed by using well diffusion method.Results: Among the six probiotic strains tested, all showed good survivability at high bile salt concentration (0.3 to 2.0 % oxgall and good growth at a low pH of 1.5 to 3.5. These probiotic species showed good survival abilities in acidic pH of 2.0 to 3.5 except Lactobacillus delbrueckii subspp. bulgaricus 281 which did not grown at pH of 2.0. Lactobacillus fermentum 141 was able to grow even at pH of 1.5 also. Among the six lactic acid species, Lactobacillus fermentum 141 (except Tetracycline, Lactobacillus delbrueckii subspp. Bulgaricus 281 except (Cefpodoxime and all other LAB were resistant to all the antibiotics tested (Ampicillin, Nalidixic acid , Ciprofloxacin ,Co-Trimoxazole, Gentamicin and Cefpodoxime. All these probiotic organisms were screened for their in vitro inhibition ability against pathogenic microorganisms namely, E.coli ATCC (American type culture collection centre, Pseudomonas aeruginosa, Salmonella paratyphi, Staphylococcus aureus. Lactobacillus delbrueckii subspp. bulgaricus 281, Lactobacillus casei 297 and Lactobacillus fermentum 141 inhibited the growth of all the pathogenic bacteria used in the study. Conclusion: The study indicated Lactobacillus fermentum 141 and Lactobacillus casei 297 as potential functional probiotics for future in vivo studies for

Molecular diagnosis of bacterial vaginosis: Does adjustment for total bacterial load or human cellular content improve diagnostic performance?

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Plummer, E L; Garland, S M; Bradshaw, C S; Law, M G; Vodstrcil, L A; Hocking, J S; Fairley, C K; Tabrizi, S N

2017-02-01

We investigated the utility of quantitative PCR assays for diagnosis of bacterial vaginosis and found that while the best model utilized bacterial copy number adjusted for total bacterial load (sensitivity=98%, specificity=93%, AUC=0.95[95%CI=0.93,0.97]), adjusting for total bacterial or human cell load did not consistently increase the diagnostic performance of the assays. Copyright © 2017 Elsevier B.V. All rights reserved.

Glyphosate Utilization as the Source of Carbon: Isolation and Identification of new Bacteria

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M. Mohsen Nourouzi

2011-01-01

Full Text Available Mixed bacteria from oil palm plantation soil (OPS were isolated to investigate their ability to utilize glyphosate as carbon source. Results showed that approximately all of the glyphosate was converted to aminomethyl-phosphonic acid (AMPA (99.5%. It is worthy to note that mixed bacteria were able to degrade only 2% of AMPA to further metabolites. Two bacterial strains i.e. Stenotrophomonas maltophilia and Providencia alcalifaciens were obtained from enrichment culture. Bacterial isolates were cultured individually on glyphosate as a sole carbon source. It was observed that both isolates were able to convert glyphosate to AMPA.

‘Khoudiadiopia massiliensis’ gen. nov., sp. nov., strain Marseille-P2746TT, a new bacterial genus isolated from the female genital tract

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A. Diop

2017-09-01

Full Text Available We report the main characteristics of ‘Khoudiadiopia massiliensis’ gen. nov., sp. nov., strain Marseille-P2746T (= CSUR P2746, a new member of the Peptoniphilaceae family isolated from a vaginal swab of a patient suffering from bacterial vaginosis.

Degradation of polynuclear aromatic hydrocarbons by two strains of Pseudomonas.

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Nwinyi, Obinna C; Ajayi, Oluseyi O; Amund, Olukayode O

2016-01-01

The goal of this investigation was to isolate competent polynuclear aromatic hydrocarbons degraders that can utilize polynuclear aromatic hydrocarbons of former industrial sites at McDoel Switchyard in Bloomington, Indiana. Using conventional enrichment method based on soil slurry, we isolated, screened and purified two bacterial species strains PB1 and PB2. Applying the ribotyping technique using the 16S rRNA gene analysis, the strains were assigned to the genus Pseudomonas (Pseudomonas plecoglossicida strain PB1 and Pseudomonas sp. PB2). Both isolates showed promising metabolic capacity on pyrene sprayed MS agar plates during the preliminary investigations. Using time course studies in the liquid cultures at calculated concentrations 123, 64, 97 and 94ppm for naphthalene, chrysene, fluroanthene and pyrene, P. plecoglossicida strain PB1 and Pseudomonas sp. PB2 showed partial utilization of the polynuclear aromatic hydrocarbons. Naphthalene was degraded between 26% and 40%, chrysene 14% and 16%, fluroanthene 5% and 7%; pyrene 8% and 13% by P. plecoglossicida strain PB1 and Pseudomonas sp. PB2 respectively. Based on their growth profile, we developed a model R(2)=1 to predict the degradation rate of slow polynuclear aromatic hydrocarbon-degraders where all the necessary parameters are constant. From this investigation, we confirm that the former industrial site soil microbial communities may be explored for the biorestoration of the industrial site. Copyright © 2016. Published by Elsevier Editora Ltda.

Correlation of Lactobacillus rhamnosus Genotypes and Carbohydrate Utilization Signatures Determined by Phenotype Profiling.

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Ceapa, Corina; Lambert, Jolanda; van Limpt, Kees; Wels, Michiel; Smokvina, Tamara; Knol, Jan; Kleerebezem, Michiel

2015-08-15

Lactobacillus rhamnosus is a bacterial species commonly colonizing the gastrointestinal (GI) tract of humans and also frequently used in food products. While some strains have been studied extensively, physiological variability among isolates of the species found in healthy humans or their diet is largely unexplored. The aim of this study was to characterize the diversity of carbohydrate utilization capabilities of human isolates and food-derived strains of L. rhamnosus in relation to their niche of isolation and genotype. We investigated the genotypic and phenotypic diversity of 25 out of 65 L. rhamnosus strains from various niches, mainly human feces and fermented dairy products. Genetic fingerprinting of the strains by amplified fragment length polymorphism (AFLP) identified 11 distinct subgroups at 70% similarity and suggested niche enrichment within particular genetic clades. High-resolution carbohydrate utilization profiling (OmniLog) identified 14 carbon sources that could be used by all of the strains tested for growth, while the utilization of 58 carbon sources differed significantly between strains, enabling the stratification of L. rhamnosus strains into three metabolic clusters that partially correlate with the genotypic clades but appear uncorrelated with the strain's origin of isolation. Draft genome sequences of 8 strains were generated and employed in a gene-trait matching (GTM) analysis together with the publicly available genomes of L. rhamnosus GG (ATCC 53103) and HN001 for several carbohydrates that were distinct for the different metabolic clusters: l-rhamnose, cellobiose, l-sorbose, and α-methyl-d-glucoside. From the analysis, candidate genes were identified that correlate with l-sorbose and α-methyl-d-glucoside utilization, and the proposed function of these genes could be confirmed by heterologous expression in a strain lacking the genes. This study expands our insight into the phenotypic and genotypic diversity of the species L. rhamnosus

The use of 14C-FIAU to predict bacterial thymidine kinase presence: Implications for radiolabeled FIAU bacterial imaging

International Nuclear Information System (INIS)

Peterson, Kristin L.; Reid, William C.; Freeman, Alexandra F.; Holland, Steven M.; Pettigrew, Roderic I.; Gharib, Ahmed M.; Hammoud, Dima A.

2013-01-01

Currently available infectious disease imaging techniques cannot differentiate between infection and sterile inflammation or between different types of infections. Recently, radiolabeled FIAU was found to be a substrate for the thymidine kinase (TK) enzyme of multiple pathogenic bacteria, leading to its translational use in the imaging of bacterial infections. Patients with immunodeficiencies, however, are susceptible to a different group of pathogenic bacteria when compared to immunocompetent subjects. In this study, we wanted to predict the usefulness of radiolabeled FIAU in the detection of bacterial infections commonly occurring in patients with immunodeficiencies, in vitro, prior to attempting in vivo imaging with 124 I-FIAU-PET. Methods: We obtained representative strains of bacterial pathogens isolated from actual patients with genetic immunodeficiencies. We evaluated the bacterial susceptibility of different strains to the effect of incubation with FIAU, which would implicate the presence of the thymidine kinase (TK) enzyme. We also incubated the bacteria with 14 C-FIAU and consequently measured its rate of incorporation in the bacterial DNA using a liquid scintillation counter. Results: Unlike the other bacterial strains, the growth of Pseudomonas aeruginosa was not halted by FIAU at any concentration. All the tested clinical isolates demonstrated different levels of 14 C-FIAU uptake, except for P. aeruginosa. Conclusion: Radiolabeled FIAU has been successful in delineating bacterial infections, both in preclinical and pilot translational studies. In patients with immunodeficiencies, Pseudomonas infections are commonly encountered and are usually difficult to differentiate from fungal infections. The use of radiolabeled FIAU for in vivo imaging of those patients, however, would not be useful, considering the apparent lack of TK enzyme in Pseudomonas. One has to keep in mind that not all pathogenic bacteria possess the TK enzyme and as such will not all

Brucella abortus strain 2308 Wisconsin genome: importance of the definition of reference strains

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Marcela Suárez-Esquivel

2016-09-01

Full Text Available Brucellosis is a bacterial infectious disease affecting a wide range of mammals and a neglected zoonosis caused by species of the genetically homogenous genus Brucella. As in most studies on bacterial diseases, research in brucellosis is carried out by using reference strains as canonical models to understand the mechanisms underlying host pathogen interactions. We performed whole genome sequencing (WGS analysis of the reference strain Brucella abortus 2308 routinely used in our laboratory, including manual curated annotation accessible as an editable version at www.wikipedia.Comparison of this genome with two publically available 2308 genomes showed significant differences, particularly indels related to insertional elements, suggesting variability related to the transposition of these elements within the same strain. Considering the outcome of high resolution genomic techniques in the bacteriology field, the conventional concept of strain definition needs to be revised.

Substrate specificity of glucose dehydrogenase and carbon source utilization pattern of pantoea dispersa strain P2 and its radiation induced mutants

International Nuclear Information System (INIS)

Lee, Young Keun; Murugesan, Senthilkumar

2009-01-01

Mineral phosphate solubilizing pantoea dispersa strain P2 produced 5.5 mM and 42.6 mM of gluconic acid on 24 h and 72 h incubation, respectively. Strain P2 exhibited glucose dehydrogenase (GDH) specific activity of 0.32 IU mg -1 protein. We have studied the substrate specificity of GDH as well as carbon source utilization pattern of strain P2. GDH of strain P2 did not use ribose as substrate. Utilization of lactose with specific activity of 0.65 IU mg -1 protein indicated that the enzyme belongs to GDH type B isozyme. Arabinose, galactose, ribose, sucrose and xylose did not induce the synthesis of GDH enzyme while mannose induced the synthesis of GDH with highest specific activity of 0.58 IU mg -1 protein. Through radiation mutagenesis, the substrate specificity of GDH was modified in order to utilize side range of sugars available in root exudates. Ribose, originally not a substrate for GDH of strain P2 was utilized as substrate by mutants P2-M5 with specific activity of 0.44 and 0.57 IU mg -1 protein, respectively. Specific activity of GDH on the media containing lactose and galactose was also improved to 1.2 and 0.52 IU mg -1 protein in P2-M5 and P2-M6 respectively. Based on the carbon source availability in root exudate, the mutants can be selected and utilized as efficient biofertilizer under P-deficient soil conditions

Morphological characterization of several strains of the rice-pathogenic bacterium Burkholderia glumae in North Sumatra

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Hasibuan, M.; Safni, I.; Lisnawita; Lubis, K.

2018-02-01

Burkholderia glumae is a quarantine seed-borne bacterial pathogen causing panicle blight disease on rice. This pathogen has been detected in some locations in Java, and recently, farmers in North Sumatra have reported rice yield loss with symptoms similar with those on rice infeced by the rice-pathogenic bacterium B. glumae. This research was aimed to isolate several bacterial strains from several rice varieties in various locations in North Sumatra and characterize the morphology of the strains to detect and identify the unknown bacterial strains presumably B. glumae. Several rice seed varieties were collected from Medan and Deli Serdang Districts. The seed samples were extracted, isolated and purified, then grown in semi-selective media PPGA. The morphological characteristics of the bacterial strains were determined including Gram staining, bacterial colony’s and bacterial cell’s morphology. The results showed that of eleven strains isolated, two strains were Gram negative and nine strains were Gram positive. On the basis of colony morphology, all strains had circular form, flat elevation and cream colour while the colony margin varied, i.e. entire and undulate. Most strains had bacillus/rod shape (8 strains) and only 3 strains were coccus.

Bacterial biofilms utilization of low concentrations of organic matter on hydrophile surfaces submerged in seawater

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Aurelia Manuela Moldoveanu

2011-12-01

Full Text Available A series of experiments were designed to determine the effect and the metabolic rate utilization of various types of organic matter in low concentration by heterotrophic marine bacteria using as Henrici slide technique as culture method and “in vitro” static conditions in sterile containers in order to obtain bacterial biofilms on the hydrophile surface of glass. The bacteria attachment and biofilm formation was analyzed for a period from 2 hours to 72 hours in order to observe de first phase of biofilm formation in condition of seawater supplied  with organic matter and noninvasive optic microscopy analysis. The utilization of five different  types of organic substances (amino-acid mixture, yeast extract, tryptone, glucose and starch reveled that bacteria multiply and are otherwise physiologically active in this very dilute nutrient solutions of 0.1% and also the results revealed that the bacterial growth was considerable in the case of the substances like amino-acid mixture with a total density of 30.9∙103 cells/mm2  and tryptone with a total density of 28.85∙103 cells/mm2  comparable to the other types of organic matter used to supply the seawater

[Features of interaction bacterial strains Micrococcus luteus LBK1 from plants varieties/hybrids cucumber and sweet pepper and with fungus Fusarium oxysporum Scelecht].

Science.gov (United States)

Parfeniuk, A; Sterlikova, O; Beznosko, I; Krut', V

2014-01-01

The article presents the results of studying the impact of bacterial strain M. luteus LBK1, stimulating the growth and development of plant varieties/hybrids of cucumber and sweet pepper on the intensity of sporulation of the fungus F. oxysporum Scelecht--fusariose rot pathogen.

Metabolism of Toxic Sugars by Strains of the Bee Gut Symbiont Gilliamella apicola

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Hao Zheng

2016-11-01

Full Text Available Social bees collect carbohydrate-rich food to support their colonies, and yet, certain carbohydrates present in their diet or produced through the breakdown of pollen are toxic to bees. The gut microbiota of social bees is dominated by a few core bacterial species, including the Gram-negative species Gilliamella apicola. We isolated 42 strains of G. apicola from guts of honey bees and bumble bees and sequenced their genomes. All of the G. apicola strains share high 16S rRNA gene similarity, but they vary extensively in gene repertoires related to carbohydrate metabolism. Predicted abilities to utilize different sugars were verified experimentally. Some strains can utilize mannose, arabinose, xylose, or rhamnose (monosaccharides that can cause toxicity in bees as their sole carbon and energy source. All of the G. apicola strains possess a manO-associated mannose family phosphotransferase system; phylogenetic analyses suggest that this was acquired from Firmicutes through horizontal gene transfer. The metabolism of mannose is specifically dependent on the presence of mannose-6-phosphate isomerase (MPI. Neither growth rates nor the utilization of glucose and fructose are affected in the presence of mannose when the gene encoding MPI is absent from the genome, suggesting that mannose is not taken up by G. apicola strains which harbor the phosphotransferase system but do not encode the MPI. Given their ability to simultaneously utilize glucose, fructose, and mannose, as well as the ability of many strains to break down other potentially toxic carbohydrates, G. apicola bacteria may have key roles in improving dietary tolerances and maintaining the health of their bee hosts.

Evaluation of antifungal activity from Bacillus strains against ...

African Journals Online (AJOL)

In this study, 30 bacterial strains isolated from marine biofilms were screened for their antifungal activity against Rhizoctonia solani by dual culture assay. Two bacterial strains, Bacillus subtilis and Bacillus cereus, showed a clear antagonism against R. solani on potato dextrose agar (PDA) medium. The antagonistic activity ...

Strain Dependent Genetic Networks for Antibiotic-Sensitivity in a Bacterial Pathogen with a Large Pan-Genome.

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Tim van Opijnen

2016-09-01

Full Text Available The interaction between an antibiotic and bacterium is not merely restricted to the drug and its direct target, rather antibiotic induced stress seems to resonate through the bacterium, creating selective pressures that drive the emergence of adaptive mutations not only in the direct target, but in genes involved in many different fundamental processes as well. Surprisingly, it has been shown that adaptive mutations do not necessarily have the same effect in all species, indicating that the genetic background influences how phenotypes are manifested. However, to what extent the genetic background affects the manner in which a bacterium experiences antibiotic stress, and how this stress is processed is unclear. Here we employ the genome-wide tool Tn-Seq to construct daptomycin-sensitivity profiles for two strains of the bacterial pathogen Streptococcus pneumoniae. Remarkably, over half of the genes that are important for dealing with antibiotic-induced stress in one strain are dispensable in another. By confirming over 100 genotype-phenotype relationships, probing potassium-loss, employing genetic interaction mapping as well as temporal gene-expression experiments we reveal genome-wide conditionally important/essential genes, we discover roles for genes with unknown function, and uncover parts of the antibiotic's mode-of-action. Moreover, by mapping the underlying genomic network for two query genes we encounter little conservation in network connectivity between strains as well as profound differences in regulatory relationships. Our approach uniquely enables genome-wide fitness comparisons across strains, facilitating the discovery that antibiotic responses are complex events that can vary widely between strains, which suggests that in some cases the emergence of resistance could be strain specific and at least for species with a large pan-genome less predictable.

Vaginal lactobacilli inhibiting growth of Gardnerella vaginalis, Mobiluncus and other bacterial species cultured from vaginal content of women with bacterial vaginosis.

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Skarin, A; Sylwan, J

1986-12-01

On a solid agar medium the growth-inhibitory effect of 9 Lactobacillus strains cultured from vaginal content was tested on bacteria cultured from vaginal content of women with bacterial vaginosis: Mobiluncus, Gardnerella vaginalis, Bacteroides and anaerobic cocci. Inhibition zones were observed in the growth of all of the strains isolated from women with bacterial vaginosis around all lactobacilli. The inhibitory effect of the lactobacilli was further tested on various anaerobic and facultatively anaerobic species, both type strains and fresh extragenitally cultured strains. Four Bacteroides fragilis strains as well as 2 out of 4 Staphylococcus aureus strains were clearly inhibited by the lactobacilli. The inhibition zones were generally wider at pH 5.5 than at 6.0. For all inhibited strains, (the S. aureus excepted) a low pH on the agar around the lactobacilli correlated to wider growth-inhibition zones.

Preparation of pyridostigmine bromide labeled with carbon-14 and tritium

Energy Technology Data Exchange (ETDEWEB)

Kepler, J.A.; Twine, C.E.; Austin, R.D. (Research Triangle Inst., Research Triangle Park, NC (United States))

1992-08-01

[2-[sup 14]C]Pyridostigmine bromide was prepared in 17.6% radiochemical yield with specific activity of 18 mCi/mmol. The reaction sequence involved preparation of 2-furan[[sup 14]C]carboxylic acid by carbonation of 2-lithiofuran, followed by conversion to 2-amino[[sup 14]C]methylfuran by lithium aluminium hydride reduction of its carboxamide. Oxidative rearrangement of 2-amino[[sup 14]C]methylfuran gave 3-hydroxy[2-[sup 14]C]pyridine which was converted to [2-[sup 14]C]pyridostigmine bromide by reaction with dimethylcarbamyl chloride and quarternization with bromomethane. Pyridostigmine bromide labeled in the methyl group of the carbamate function was prepared in 73% yield with specific activity of 37.6 mCi/mmol by reaction of bis-3-pyridyl carbonate with [[sup 14]C]dimethylamine followed by quarternization with bromomethane. [6-[sup 3]H]-Pyridostigmine bromide with specific activity of 22.5 mCi/mmol was prepared by catalytic halogen-tritium replacement of 2,6-dibromo-3-dimethylcarbamyloxypyridine followed by quarternization with bromomethane and back-exchanging the labile 2-tritium. (author).

Preparation of pyridostigmine bromide labeled with carbon-14 and tritium

International Nuclear Information System (INIS)

Kepler, J.A.; Twine, C.E.; Austin, R.D.

1992-01-01

[2- 14 C]Pyridostigmine bromide was prepared in 17.6% radiochemical yield with specific activity of 18 mCi/mmol. The reaction sequence involved preparation of 2-furan[ 14 C]carboxylic acid by carbonation of 2-lithiofuran, followed by conversion to 2-amino[ 14 C]methylfuran by lithium aluminium hydride reduction of its carboxamide. Oxidative rearrangement of 2-amino[ 14 C]methylfuran gave 3-hydroxy[2- 14 C]pyridine which was converted to [2- 14 C]pyridostigmine bromide by reaction with dimethylcarbamyl chloride and quarternization with bromomethane. Pyridostigmine bromide labeled in the methyl group of the carbamate function was prepared in 73% yield with specific activity of 37.6 mCi/mmol by reaction of bis-3-pyridyl carbonate with [ 14 C]dimethylamine followed by quarternization with bromomethane. [6- 3 H]-Pyridostigmine bromide with specific activity of 22.5 mCi/mmol was prepared by catalytic halogen-tritium replacement of 2,6-dibromo-3-dimethylcarbamyloxypyridine followed by quarternization with bromomethane and back-exchanging the labile 2-tritium. (author)

Quillaja saponaria Saponins with Potential to Enhance the Effectiveness of Disinfection Processes in the Beverage Industry

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Hubert Antolak

2018-03-01

Full Text Available This study examines the in vitro effect of Quillaja saponaria extracts on Asaia spp. planktonic cells and biofilms, in comparison and combination with two disinfectants: peracetic acid and N-ethyl-N,N-dimethylhexadecylammonium bromide. The growth of six bacterial strains was evaluated spectrophotometrically. Biofilm eradication was determined using the plate count method and luminometry. The planktonic cells were characterized by relatively high resistance to peracetic acid and higher sensitivity to N-ethylo-N,N-dimethylohexadecylioamonium bromide. In almost all the tested strains, growth was inhibited by 0.125% (v/v peracetic acid and 0.0313% (w/v quaternary ammonium compound. However, combinations of cell pretreatment using saponin and peracetic acid action were the most efficient against both planktonic and biofilm cells. The minimum inhibitory concentrations for peracetic acid were 4–8 times lower than those for bacterial strains without preliminary saponin action. Eradication of Asaia spp. biofilms reduced the number of living cells by 4–5 logarithmic units. These results demonstrate the synergetic action of saponin extract and disinfectant, and could be useful in the development of industrial strategies against Asaia spp. biofilms.

Synergistic and additive effect of oregano essential oil and biological silver nanoparticles against multidrug-resistant bacterial strains

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Sara eScandorieiro

2016-05-01

Full Text Available Bacterial resistance to conventional antibiotics has become a clinical and public health problem, making therapeutic decisions more challenging. Plant compounds and nanodrugs have been proposed as potential antimicrobial alternatives. Studies have shown that oregano (Origanum vulgare essential oil (OEO and silver nanoparticles have potent antibacterial activity, also against multidrug-resistant strains; however, the strong organoleptic characteristics of OEO and the development of resistance to these metal nanoparticles can limit their use. This study evaluated the antibacterial effect of a two-drug combination of biologically synthesized silver nanoparticles (bio-AgNP, produced by Fusarium oxysporum, and OEO against Gram-positive and Gram-negative bacteria, including multidrug-resistant strains. OEO and bio-AgNP showed bactericidal effects against all seventeen strains tested, with minimal inhibitory concentrations (MIC ranging from 0.298 to 1.193 mg/mL and 62.5 to 250 µM, respectively. Time-kill curves indicated that OEO acted rapidly (within 10 min, while the metallic nanoparticles took 4 h to kill Gram-negative bacteria and 24 h to kill Gram-positive bacteria. The combination of the two compounds resulted in a synergistic or additive effect, reducing their MIC values and reducing the time of action compared to bio-AgNP used alone, i.e., 20 min for Gram-negative bacteria and 7 h for Gram-positive bacteria. Scanning electron microscopy (SEM revealed similar morphological alterations in Staphylococcus aureus (non-methicillin-resistant S. aureus, non-MRSA cells exposed to three different treatments (OEO, bio-AgNP and combination of the two, which appeared cell surface blebbing. Individual and combined treatments showed reduction in cell density and decrease in exopolysaccharide matrix compared to untreated bacterial cells. It indicated that this composition have an antimicrobial activity against S. aureus by disrupting cells. Both compounds

Synergistic and Additive Effect of Oregano Essential Oil and Biological Silver Nanoparticles against Multidrug-Resistant Bacterial Strains.

Science.gov (United States)

Scandorieiro, Sara; de Camargo, Larissa C; Lancheros, Cesar A C; Yamada-Ogatta, Sueli F; Nakamura, Celso V; de Oliveira, Admilton G; Andrade, Célia G T J; Duran, Nelson; Nakazato, Gerson; Kobayashi, Renata K T

2016-01-01

Bacterial resistance to conventional antibiotics has become a clinical and public health problem, making therapeutic decisions more challenging. Plant compounds and nanodrugs have been proposed as potential antimicrobial alternatives. Studies have shown that oregano (Origanum vulgare) essential oil (OEO) and silver nanoparticles have potent antibacterial activity, also against multidrug-resistant strains; however, the strong organoleptic characteristics of OEO and the development of resistance to these metal nanoparticles can limit their use. This study evaluated the antibacterial effect of a two-drug combination of biologically synthesized silver nanoparticles (bio-AgNP), produced by Fusarium oxysporum, and OEO against Gram-positive and Gram-negative bacteria, including multidrug-resistant strains. OEO and bio-AgNP showed bactericidal effects against all 17 strains tested, with minimal inhibitory concentrations (MIC) ranging from 0.298 to 1.193 mg/mL and 62.5 to 250 μM, respectively. Time-kill curves indicated that OEO acted rapidly (within 10 min), while the metallic nanoparticles took 4 h to kill Gram-negative bacteria and 24 h to kill Gram-positive bacteria. The combination of the two compounds resulted in a synergistic or additive effect, reducing their MIC values and reducing the time of action compared to bio-AgNP used alone, i.e., 20 min for Gram-negative bacteria and 7 h for Gram-positive bacteria. Scanning electron microscopy (SEM) revealed similar morphological alterations in Staphylococcus aureus (non-methicillin-resistant S. aureus, non-MRSA) cells exposed to three different treatments (OEO, bio-AgNP and combination of the two), which appeared cell surface blebbing. Individual and combined treatments showed reduction in cell density and decrease in exopolysaccharide matrix compared to untreated bacterial cells. It indicated that this composition have an antimicrobial activity against S. aureus by disrupting cells. Both compounds showed very low

Bacterial cheating limits antibiotic resistance

Science.gov (United States)

Xiao Chao, Hui; Yurtsev, Eugene; Datta, Manoshi; Artemova, Tanya; Gore, Jeff

2012-02-01

The widespread use of antibiotics has led to the evolution of resistance in bacteria. Bacteria can gain resistance to the antibiotic ampicillin by acquiring a plasmid carrying the gene beta-lactamase, which inactivates the antibiotic. This inactivation may represent a cooperative behavior, as the entire bacterial population benefits from removing the antibiotic. The cooperative nature of this growth suggests that a cheater strain---which does not contribute to breaking down the antibiotic---may be able to take advantage of cells cooperatively inactivating the antibiotic. Here we find experimentally that a ``sensitive'' bacterial strain lacking the plasmid conferring resistance can invade a population of resistant bacteria, even in antibiotic concentrations that should kill the sensitive strain. We observe stable coexistence between the two strains and find that a simple model successfully explains the behavior as a function of antibiotic concentration and cell density. We anticipate that our results will provide insight into the evolutionary origin of phenotypic diversity and cooperative behaviors.

Brucella abortus Strain 2308 Wisconsin Genome: Importance of the Definition of Reference Strains

Science.gov (United States)

Suárez-Esquivel, Marcela; Ruiz-Villalobos, Nazareth; Castillo-Zeledón, Amanda; Jiménez-Rojas, César; Roop II, R. Martin; Comerci, Diego J.; Barquero-Calvo, Elías; Chacón-Díaz, Carlos; Caswell, Clayton C.; Baker, Kate S.; Chaves-Olarte, Esteban; Thomson, Nicholas R.; Moreno, Edgardo; Letesson, Jean J.; De Bolle, Xavier; Guzmán-Verri, Caterina

2016-01-01

Brucellosis is a bacterial infectious disease affecting a wide range of mammals and a neglected zoonosis caused by species of the genetically homogenous genus Brucella. As in most studies on bacterial diseases, research in brucellosis is carried out by using reference strains as canonical models to understand the mechanisms underlying host pathogen interactions. We performed whole genome sequencing analysis of the reference strain B. abortus 2308 routinely used in our laboratory, including manual curated annotation accessible as an editable version through a link at https://en.wikipedia.org/wiki/Brucella#Genomics. Comparison of this genome with two publically available 2308 genomes showed significant differences, particularly indels related to insertional elements, suggesting variability related to the transposition of these elements within the same strain. Considering the outcome of high resolution genomic techniques in the bacteriology field, the conventional concept of strain definition needs to be revised. PMID:27746773

A comparison of the effect of intranasal desmopressin and intramuscular hyoscine N-butyl bromide combination with intramuscular hyoscine N-butyl bromide alone in acute renal colic

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Abdol-Reza Kheirollahi

2010-01-01

Full Text Available Background: Patients with acute renal colic usually require immediate diagnosis and treatment. In this clinical trial analgesic effect of hyoscine N-butyl bromide and desmopressin combination in comparison with hyoscine N-butyl bromide alone in patients with acute renal colic induced by urinary stones was assessed. Methods: The study included 114 patients randomly allocated in two groups (A and B. Patients in group A received 20 mg intramuscular hyoscine N-butyl bromide at admission time and patients in group B received 20 μg of intranasal desmopressin in combination with 20 mg intramuscular hyoscine N-butyl bromide. A visual analogue scale (VAS; a 10-cm horizontal scale ranging from "zero or no pain" to "10 or unbearable pain" was hired to assess the patients′ pain severity at baseline, 30 and 60 minutes after the treatments. Results: On admission, the pain level was similar in both groups (group A: 8.95 ± 0.11 and group B: 8.95 ± 0.12. In group A, the mean of pain level showed a decrease after 30 minutes (group A: 7.26 ± 0.25 and group B: 5.95 ± 0.28 but further decreasing did not occur; however in group B, the pain consistently decreased and the mean after 60 minutes was significantly decreased (group A: 6.80 ± 0.31 and group B: 3.71 ± 0.31. No side effects were detected in this study. Conclusions: The combination of hyoscine N-butyl bromide and desmopressin is more effective than hyoscine N-butyl bromide alone in patients with renal colic. Further studies are recommended to validate these findings and compare the different doses of desmopressin.

Profile of aclidinium bromide in the treatment of chronic obstructive pulmonary disease

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Sims MW

2011-09-01

Full Text Available Michael W Sims, Reynold A Panettieri, Jr. Pulmonary, Allergy, and Critical Care Division, Airways Biology Initiative, Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA Abstract: Bronchodilators provide the mainstay of pharmacologic therapy for chronic obstructive pulmonary disease (COPD, and anticholinergic bronchodilators, in particular, appear to be the most effective. There are currently two anticholinergic agents available in the US for the treatment of COPD (ipratropium bromide and tiotropium bromide, but several others are in various stages of development. Aclidinium bromide, a novel, long-acting, anticholinergic bronchodilator, is currently in Phase III trials for the management of COPD. Available evidence suggests that aclidinium is a safe and well tolerated drug with a relatively rapid onset and a sufficient duration of action to provide once-daily dosing. This article will provide a pharmacologic profile of aclidinium bromide and review the preclinical and clinical studies evaluating its safety and efficacy in the treatment of COPD. Keywords: aclidinium bromide, bronchodilators, pulmonary disease, chronic obstructive, muscarinic antagonists, pharmacokinetics, pharmacology

The inoculation method affects colonization and performance of bacterial inoculant strains in the phytoremediation of soil contaminated with diesel oil.

Science.gov (United States)

Afzal, Muhammad; Yousaf, Sohail; Reichenauer, Thomas G; Sessitsch, Angela

2012-01-01

Plants in combination with microorganisms can remediate soils, which are contaminated with organic pollutants such as petroleum hydrocarbons. Inoculation of plants with degrading bacteria is one approach to improve remediation processes, but is often not successful due to the competition with resident microorganisms. It is therefore of high importance to address the persistence and colonization behavior of inoculant strains. The objective of this study was to determine whether the inoculation method (seed imbibement and soil inoculation) influences bacterial colonization, plant growth promotion and hydrocarbon degradation. Italian ryegrass was grown in non-sterilized soil polluted with diesel and inoculated with different alkane-degrading strains Pantoea sp. ITSI10, Pantoea sp. BTRH79 and Pseudomonas sp. MixRI75 individually as well as in combination. Inoculation generally had a beneficial effect on plant biomass production and hydrocarbon degradation, however, strains inoculated in soil performed better than applied by seed imbibement. Performance correlated with the colonization efficiency of the inoculated strains. The highest hydrocarbon degradation was observed in the treatment, in which all three strains were inoculated in combination into soil. Our study revealed that besides the degradation potential and competitive ability of inoculant strains the inoculation method plays an important role in determining the success of microbial inoculation.

Substrate specificity of glucose dehydrogenase and carbon source utilization pattern of pantoea dispersa strain P2 and its radiation induced mutants

Energy Technology Data Exchange (ETDEWEB)

Lee, Young Keun; Murugesan, Senthilkumar [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

2009-06-15

Mineral phosphate solubilizing pantoea dispersa strain P2 produced 5.5 mM and 42.6 mM of gluconic acid on 24 h and 72 h incubation, respectively. Strain P2 exhibited glucose dehydrogenase (GDH) specific activity of 0.32 IU mg{sup -1} protein. We have studied the substrate specificity of GDH as well as carbon source utilization pattern of strain P2. GDH of strain P2 did not use ribose as substrate. Utilization of lactose with specific activity of 0.65 IU mg{sup -1} protein indicated that the enzyme belongs to GDH type B isozyme. Arabinose, galactose, ribose, sucrose and xylose did not induce the synthesis of GDH enzyme while mannose induced the synthesis of GDH with highest specific activity of 0.58 IU mg{sup -1} protein. Through radiation mutagenesis, the substrate specificity of GDH was modified in order to utilize side range of sugars available in root exudates. Ribose, originally not a substrate for GDH of strain P2 was utilized as substrate by mutants P2-M5 with specific activity of 0.44 and 0.57 IU mg{sup -1} protein, respectively. Specific activity of GDH on the media containing lactose and galactose was also improved to 1.2 and 0.52 IU mg{sup -1} protein in P2-M5 and P2-M6 respectively. Based on the carbon source availability in root exudate, the mutants can be selected and utilized as efficient biofertilizer under P-deficient soil conditions.

Bacterial Cellulose Production from Industrial Waste and by-Product Streams

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Erminda Tsouko

2015-07-01

Full Text Available The utilization of fermentation media derived from waste and by-product streams from biodiesel and confectionery industries could lead to highly efficient production of bacterial cellulose. Batch fermentations with the bacterial strain Komagataeibacter sucrofermentans DSM (Deutsche Sammlung von Mikroorganismen 15973 were initially carried out in synthetic media using commercial sugars and crude glycerol. The highest bacterial cellulose concentration was achieved when crude glycerol (3.2 g/L and commercial sucrose (4.9 g/L were used. The combination of crude glycerol and sunflower meal hydrolysates as the sole fermentation media resulted in bacterial cellulose production of 13.3 g/L. Similar results (13 g/L were obtained when flour-rich hydrolysates produced from confectionery industry waste streams were used. The properties of bacterial celluloses developed when different fermentation media were used showed water holding capacities of 102–138 g·water/g·dry bacterial cellulose, viscosities of 4.7–9.3 dL/g, degree of polymerization of 1889.1–2672.8, stress at break of 72.3–139.5 MPa and Young’s modulus of 0.97–1.64 GPa. This study demonstrated that by-product streams from the biodiesel industry and waste streams from confectionery industries could be used as the sole sources of nutrients for the production of bacterial cellulose with similar properties as those produced with commercial sources of nutrients.

The bacterial diversity associated with bacterial diseases on Mud Crab (Scylla serrata Fab.) from Pemalang Coast, Indonesia

Science.gov (United States)

Sarjito; Desrina; Haditomo, AHC; Budi Prayitno, S.

2018-05-01

Bacterial disease is a problem in mud crab culture in Pemalang, Indonesia. The purpose of this study was to find out the bacteria associated with bacterial diseases on mud crab based on the molecular approach. Exploratory methods were conducted in this reserach. Twenty two bacteria (SJP 01 – SJP 22) were isolated from carapace and gills and hepathopancreas of moribound mud crab with TCBS and TSA medium. Based on rep PCR, five isolates (SJP 01, SJP 02, SJP 04, SJP 10 and SJP 11) were choosen for further investigation. Result from 16S rDNA sequence analysis, SJP 01, SJP 02, SJP 04, SJP 10 and SJP 11 were closely related to Exiguobacterium sp. ZJ2505 (99%), V. harveyi strain NCIMB1280 (98%), V. alginolyticus strain ATCC 17749(98%.), B. marisflavi strain TF-11 (97%) and E. aestuarii strain TF-16 (99%) respectively.

Seaweed as source of energy. I: effect of a specific bacterial strain on biogas production

Energy Technology Data Exchange (ETDEWEB)

Rao, P.S.; Tarwade, S.J.; Sarma, K.S.R.

1980-01-01

Biogas was produced from seaweed by making use of alginate-digesting marine bacteria that were isolated from decomposing seaweed and can digest seaweed carbohydrates (agar and alginic acid). Laboratory digesters containing 100 g seaweed were inoculated with 50 mL broth cultures of different seaweed-derived bacterial strains, and the maximum amount of degradation obtained was 28% (compared with 13% for a bacteria-free digestion). Cow dung was added as a source of methanogenic bacteria, and the amount of biogas produced was more than double the amount obtained when seaweed and cow dung were digested in the absence of the seaweed-derived bacteria. Adding a small amount of Ulva to the seaweed digester increased the production of biogas.

Probing bacterial adhesion at the single-cell level

DEFF Research Database (Denmark)

Zeng, Guanghong; Müller, Torsten; Meyer, Rikke Louise

be considered. We have developed a simple and versatile method to make single-cell bacterial probes for measuring single cell adhesion by force spectroscopy using atomic force microscopy (AFM). A single-cell probe was readily made by picking up a bacterial cell from a glass surface by approaching a tipless AFM...... cantilever coated with the commercial cell adhesive CellTakTM. We applied the method to study adhesion of living cells to abiotic surfaces at the single-cell level. Immobilisation of single bacterial cells to the cantilever was stable for several hours, and viability was confirmed by Live/Dead staining...... on the adhesion force, we explored the bond formation and adhesive strength of four different bacterial strains towards three abiotic substrates with variable hydrophobicity and surface roughness. The adhesion force and final rupture length were dependent on bacterial strains, surfaces properties, and time...

Isolation and characterization of atrazine mineralizing Bacillus subtilis strain HB-6.

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Jinhua Wang

Full Text Available Atrazine is a widely used herbicide with great environmental concern due to its high potential to contaminate soil and waters. An atrazine-degrading bacterial strain HB-6 was isolated from industrial wastewater and the 16S rRNA gene sequencing identified HB-6 as a Bacillus subtilis. PCR assays indicated that HB-6 contained atrazine-degrading genes trzN, atzB and atzC. The strain HB-6 was capable of utilizing atrazine and cyanuric acid as a sole nitrogen source for growth and even cleaved the s-triazine ring and mineralized atrazine. The strain demonstrated a very high efficiency of atrazine biodegradation with a broad optimum pH and temperature ranges and could be enhanced by cooperating with other bacteria, suggesting its huge potential for remediation of atrazine-contaminated sites. To our knowledge, there are few Bacillus subtilis strains reported that can mineralize atrazine, therefore, the present work might provide some new insights on atrazine remediation.

Pancreatitis associated with potassium bromide/phenobarbital combination therapy in epileptic dogs.

OpenAIRE

Gaskill, C L; Cribb, A E

2000-01-01

In a retrospective study, at least 10% of dogs receiving potassium bromide/phenobarbital combination therapy, compared with 0.3% of dogs receiving phenobarbital monotherapy, had probable pancreatitis. Pancreatitis may be a more frequent and more serious adverse effect of potassium bromide/phenobarbital combination therapy than has been reported previously.

Selection of potent bacterial strain for over-production of PHB by using low cost carbon source for eco-friendly bioplastics

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Rahat Abdul Rehman

2015-11-01

Full Text Available Background: The microbial PHB production is a promising tool for the plastic industry for the synthesis of environmental friendly, biodegradable plastic in contrast to the conventional petro-chemical based non-degradable plastics. The selection of potent bacterial strains, inexpensive carbon source, efficient fermentation and recovery processes are important aspects that were taken into account during this study. Methods: Different bacterial strains i.e. Bacillus Spp, P. putida and P. fluorescens were screened for maximum PHB production. Under media optimization, various carbon and nitrogen sources (alone or in combination were used to achieve the maximum PHB production. Finally the degradation tests of the PHB sheet were also performed to test its biodegradability potential. Results: Shake flask studies have shown the PHB concentrations upto 7.02, 4.50 and 34.4 mg/g of dry cell mass of P. putida, P. fluorescens and Bacillus Spp. respectively. Almost same results were observed at laboratory scale production of PHB in 10 L fermenter i.e. 6.28, 6.23 and 39.5 mg/g of dry cell mass by P. putida, P. fluorescens and Bacillus Spp. respectively. On the basis of these observations, Bacillus Spp. was chosen for laboratory scale PHB production. Corn steep liquor (4% was chosen as the best medium to achieve the highest PHB contents. Isolated PHB has shown biodegradation in soil up to 86.7% at 37oC. Conclusion: The Bacillus Spp. Proved to be the best strain for PHB production on only 4% CSL which is cheapest and easily available.

Factors influencing bacterial adhesion to contact lenses.

Science.gov (United States)

Dutta, Debarun; Cole, Nerida; Willcox, Mark

2012-01-01

The process of any contact lens related keratitis generally starts with the adhesion of opportunistic pathogens to contact lens surface. This article focuses on identifying the factors which have been reported to affect bacterial adhesion to contact lenses. Adhesion to lenses differs between various genera/species/strains of bacteria. Pseudomonas aeruginosa, which is the predominant causative organism, adheres in the highest numbers to both hydrogel and silicone hydrogel lenses in vitro. The adhesion of this strain reaches maximum numbers within 1h in most in vitro studies and a biofilm has generally formed within 24 h of cells adhering to the lens surface. Physical and chemical properties of contact lens material affect bacterial adhesion. The water content of hydroxyethylmethacrylate (HEMA)-based lenses and their iconicity affect the ability of bacteria to adhere. The higher hydrophobicity of silicone hydrogel lenses compared to HEMA-based lenses has been implicated in the higher numbers of bacteria that can adhere to their surfaces. Lens wear has different effects on bacterial adhesion, partly due to differences between wearers, responses of bacterial strains and the ability of certain tear film proteins when bound to a lens surface to kill certain types of bacteria.

A study of bromide in the Mandovi-Zuari river system of Goa

Digital Repository Service at National Institute of Oceanography (India)

De; Dalal, V.N

Bromide was the subject of detailed investigation in the Mandovi Zuari river system and information was compiled on its spatial and temporal distribution. A simple mixture relation of Carpenter et. al. was applied and seawater percentage and bromide...

Paracetamol - toxicity and microbial utilization. Pseudomonas moorei KB4 as a case study for exploring degradation pathway.

Science.gov (United States)

Żur, Joanna; Wojcieszyńska, Danuta; Hupert-Kocurek, Katarzyna; Marchlewicz, Ariel; Guzik, Urszula

2018-09-01

Paracetamol, a widely used analgesic and antipyretic drug, is currently one of the most emerging pollutants worldwide. Besides its wide prevalence in the literature only several bacterial strains able to degrade this compound have been described. In this study, we isolated six new bacterial strains able to remove paracetamol. The isolated strains were identified as the members of Pseudomonas, Bacillus, Acinetobacter and Sphingomonas genera and characterized phenotypically and biochemically using standard methods. From the isolated strains, Pseudomonas moorei KB4 was able to utilize 50 mg L -1 of paracetamol. As the main degradation products, p-aminophenol and hydroquinone were identified. Based on the measurements of specific activity of acyl amidohydrolase, deaminase and hydroquinone 1,2-dioxygenase and the results of liquid chromatography analyses, we proposed a mechanism of paracetamol degradation by KB4 strain under co-metabolic conditions with glucose. Additionally, toxicity bioassays and the influence of various environmental factors, including pH, temperature, heavy metals at no-observed-effective-concentrations, and the presence of aromatic compounds on the efficiency and mechanism of paracetamol degradation by KB4 strain were determined. This comprehensive study about paracetamol biodegradation will be helpful in designing a treatment systems of wastewaters contaminated with paracetamol. Copyright © 2018 Elsevier Ltd. All rights reserved.

Elucidating Duramycin’s Bacterial Selectivity and Mode of Action on the Bacterial Cell Envelope

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Sahar Hasim

2018-02-01

Full Text Available The use of naturally occurring antimicrobial peptides provides a promising route to selectively target pathogenic agents and to shape microbiome structure. Lantibiotics, such as duramycin, are one class of bacterially produced peptidic natural products that can selectively inhibit the growth of other bacteria. However, despite longstanding characterization efforts, the microbial selectivity and mode of action of duramycin are still obscure. We describe here a suite of biological, chemical, and physical characterizations that shed new light on the selective and mechanistic aspects of duramycin activity. Bacterial screening assays have been performed using duramycin and Populus-derived bacterial isolates to determine species selectivity. Lipidomic profiles of selected resistant and sensitive strains show that the sensitivity of Gram-positive bacteria depends on the presence of phosphatidylethanolamine (PE in the cell membrane. Further the surface and interface morphology were studied by high resolution atomic force microscopy and showed a progression of cellular changes in the cell envelope after treatment with duramycin for the susceptible bacterial strains. Together, these molecular and cellular level analyses provide insight into duramycin’s mode of action and a better understanding of its selectivity.

Use of 82Br and 131I radionuclides in studies of goitrogenic effects of exogenous bromide

International Nuclear Information System (INIS)

Stanislav Pavelka

2012-01-01

The interference of excessive bromide intake with iodine metabolism in the rat was studied using 82 Br and 131 I radionuclides. Mainly lactating rat dams and their pups were used, in addition to adult male rats, in the present studies. Particularly, the influence of high bromide intake in lactating rat dams on the transfer of iodine and bromide to suckling young through breast milk was evaluated. The induction of hypothyroid status in the pups by high bromide intake in the mothers was proved unambiguously. Excessive bromide in lactating rat dams caused a marked decrease in plasma levels of thyroid hormones both, in the mothers and in their sucklings. The effects of an enhanced bromide intake on the thyroid function in relation to iodine status in the animals were also followed. Marked goitrogenic and thyrotoxic effects of excessive bromide in adult rats were significantly enhanced under the conditions of simultaneous iodine deficiency in the experimental animals. (author)

Production of putrescine-capped stable silver nanoparticle: its characterization and antibacterial activity against multidrug-resistant bacterial strains

Science.gov (United States)

Saha, Saswati; Gupta, Bhaskar; Gupta, Kamala; Chaudhuri, Mahua Ghosh

2016-11-01

Integration of biology with nanotechnology is now becoming attention-grabbing area of research. The antimicrobial potency of silver has been eminent from antiquity. Due to the recent desire for the enhancement of antibacterial efficacy of silver, various synthesis methods of silver in their nano dimensions are being practiced using a range of capping material. The present work highlights a facile biomimetic approach for production of silver nanoparticle being capped and stabilized by putrescine, possessing a diameter of 10-25 ± 1.5 nm. The synthesized nanoparticles have been analyzed spectrally and analytically. Morphological studies are carried out by high-resolution transmission electron microscopy and crystallinity by selected area electron diffraction patterns. Moreover, the elemental composition of the capped nanoparticles was confirmed by energy-dispersive X-ray spectroscopy analysis. A comparative study (zone of inhibition and minimum inhibitory concentration) regarding the interactions and antibacterial potentiality of the capped silver nanoparticles with respect to the bare ones reveal the efficiency of the capped one over the bare one. The bacterial kinetic study was executed to monitor the interference of nanoparticles with bacterial growth rate. The results also highlight the efficacy of putrescine-capped silver nanoparticles as effective growth inhibitors against multi-drug resistant human pathogenic bacterial strains, which may, thus, potentially be applicable as an effective antibacterial control system to fight diseases.

Are grazer-induced adaptations of bacterial abundance and morphology timedependent?

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Gianluca CORNO

2006-02-01

Full Text Available Predation by protists is a well known force that shapes bacterial communities and can lead to filamentous forms and aggregations of large cell clusters. These classic resistance strategies were observed as a direct consequence of predation by heteroand mixotrophic flagellates (the main group of bacteria predators in water on natural assemblages of bacteria and on single plastic strains. Recently it was shown that a long time exposure (about 30 days of a bacterial strain, characterized by high degree of phenotypic plasticity, to flagellates, without direct predation, enhanced the formation of resistant forms (filaments in a continuous culture system. Target prey populations and predators were separated by a dialysis membrane. Moreover, the positive impact on bacterial growth, due to the chemical excretes released by flagellates was demonstrated for exudates of photosynthetic activity. The same positive impact may also be seen in response to exudates related to grazing. In this study, two short-term experiments (<100 hours were conducted to test for modifications in the morphology and productivity of three different bacterial strains that were induced by the presence of active predators, but without direct predation. The growth and morphological distribution of each of the selected strains was tested separately using batch cultures. Cultures were either enriched with carbon in the presence or absence of flagellate predators, or included pre-filtered exudates from flagellate activity. In a second experiment, bottles were provided with a central dialysis bag that contained active flagellates, and were inoculated with the selected bacterial strains. In this way, bacteria were exposed to the presence of predators without direct predation. The bacterial strains used in this experience were characterised by a high degree of phenotypic plasticity and exhibited different successful strategies of resistance against grazing. The flagellates selected as

Pathogenicity of a Very Virulent Strain of Marek's Disease Herpesvirus Cloned as Infectious Bacterial Artificial Chromosomes

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Lorraine P. Smith

2011-01-01

Full Text Available Bacterial artificial chromosome (BAC vectors containing the full-length genomes of several herpesviruses have been used widely as tools to enable functional studies of viral genes. Marek's disease viruses (MDVs are highly oncogenic alphaherpesviruses that induce rapid-onset T-cell lymphomas in chickens. Oncogenic strains of MDV reconstituted from BAC clones have been used to examine the role of viral genes in inducing tumours. Past studies have demonstrated continuous increase in virulence of MDV strains. We have previously reported on the UK isolate C12/130 that showed increased virulence features including lymphoid organ atrophy and enhanced tropism for the central nervous system. Here we report the construction of the BAC clones (pC12/130 of this strain. Chickens were infected with viruses reconstituted from the pC12/130 clones along with the wild-type virus for the comparison of the pathogenic properties. Our studies show that BAC-derived viruses induced disease similar to the wild-type virus, though there were differences in the levels of pathogenicity between individual viruses. Generation of BAC clones that differ in the potential to induce cytolytic disease provide the opportunity to identify the molecular determinants of increased virulence by direct sequence analysis as well as by using reverse genetics approaches on the infectious BAC clones.

Enhanced biodegradation of alkane hydrocarbons and crude oil by mixed strains and bacterial community analysis.

Science.gov (United States)

Chen, Yu; Li, Chen; Zhou, Zhengxi; Wen, Jianping; You, Xueyi; Mao, Youzhi; Lu, Chunzhe; Huo, Guangxin; Jia, Xiaoqiang

2014-04-01

In this study, two strains, Acinetobacter sp. XM-02 and Pseudomonas sp. XM-01, were isolated from soil samples polluted by crude oil at Bohai offshore. The former one could degrade alkane hydrocarbons (crude oil and diesel, 1:4 (v/v)) and crude oil efficiently; the latter one failed to grow on alkane hydrocarbons but could produce rhamnolipid (a biosurfactant) with glycerol as sole carbon source. Compared with pure culture, mixed culture of the two strains showed higher capability in degrading alkane hydrocarbons and crude oil of which degradation rate were increased from 89.35 and 74.32 ± 4.09 to 97.41 and 87.29 ± 2.41 %, respectively. In the mixed culture, Acinetobacter sp. XM-02 grew fast with sufficient carbon source and produced intermediates which were subsequently utilized for the growth of Pseudomonas sp. XM-01 and then, rhamnolipid was produced by Pseudomonas sp. XM-01. Till the end of the process, Acinetobacter sp. XM-02 was inhibited by the rapid growth of Pseudomonas sp. XM-01. In addition, alkane hydrocarbon degradation rate of the mixed culture increased by 8.06 to 97.41 % compared with 87.29 % of the pure culture. The surface tension of medium dropping from 73.2 × 10(-3) to 28.6 × 10(-3) N/m. Based on newly found cooperation between the degrader and the coworking strain, rational investigations and optimal strategies to alkane hydrocarbons biodegradation were utilized for enhancing crude oil biodegradation.

Role of overexpressed CFA/I fimbriae in bacterial swimming.

Science.gov (United States)

Cao, Ling; Suo, Zhiyong; Lim, Timothy; Jun, Sangmu; Deliorman, Muhammedin; Riccardi, Carol; Kellerman, Laura; Avci, Recep; Yang, Xinghong

2012-06-01

Enterotoxigenic Escherichia coli CFA/I is a protective antigen and has been overexpressed in bacterial vectors, such as Salmonella Typhimurium H683, to generate vaccines. Effects that overexpressed CFA/I may engender on the bacterial host remain largely unexplored. To investigate, we constructed a high CFA/I expression strain, H683-pC2, and compared it to a low CFA/I expression strain, H683-pC, and to a non-CFA/I expression strain, H683-pY. The results showed that H683-pC2 was less able to migrate into semisolid agar (0.35%) than either H683-pC or H683-pY. Bacteria that migrated showed motility halo sizes of H683-pC2 CFA/I fimbriae on bacterial swimming motility.

Pitting Corrosion Behavior of 304 SS and 316 SS Alloys in Aqueous Chloride and Bromide Solutions

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Ibtehal Kareem Shakir

2018-01-01

Full Text Available The importance of the present work falls on the pitting corrosion behavior investigation of 304 SS and 316 SS alloys in 3.5 wt% of aqueous solution bearing with chloride and bromide anion at different solutions temperature range starting from (20-50oC due to the pitting corrosion tremendous effect on the economic, safety and materials loss due to leakage. The impact of solution temperatures on the pitting corrosion resistance at 3.5wt% (NaCl and NaBr solutions for the 304 SS and 316 SS has been investigated utilizing the cyclic polarization techniques at the potential range -400 to1000 mV vs. SCE at 40 mV/sec scan rate followed by the surface characterization employing Scanning Electron Microscope. The results show that a significant decline in the pitting corrosion potential Ep values of both stainless steel alloys in chloride and bromide solution during temperature increase attributed to the pitting corrosion potential decreased arises from the modification of the passive film properties. The surface examination using optical microscope and scanning electron microscope prove the occurring of higher pitting density over 304 SS in chloride solution than that observed in bromide solution with a non-circular lacy cover pitfall out at the center and falls inside the pits hall in comparison to the isolated circular lacy cover pit formed on 316 SS in 3.5wt% NaBr solution at 50 oC.

Evaluation of biofilm formation by bacterial strains isolated from milking equipment and milk samples from cows with mastitis

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Laura Gonçalves da Silva Chagas

2017-08-01

Full Text Available The presence of biofilm-forming bacteria from the mammary gland of dairy cows adhered to equipment in the milking environment represents one of the major causes of bacterial resistance during mastitis treatment. The aim of this study was to identify strains of Staphylococcus aureus, Staphylococcus epidermidis and Escherichia coli in milk samples from cows with mastitis, as well as in the expansion tank and milking set liners. We aimed to quantify the extracellular proteins and polysaccharides in the biofilm produced by each strain. A total of 294 samples were collected from a dairy farm in the municipality of Uberlândia, Minas Gerais. To identify the S. aureus, S. epidermidis and E. coli isolates responsible for biofilm production, we tested the phenotype using the Congo red agar (CRA and microplate adhesion tests. Protein quantification was performed with a Bicinchoninic Acid Protein Assay Kit (BCA kit, and polysaccharides were quantified by the phenol sulfuric acid method. We identified eight strains of S. aureus, one strain of S. epidermidis and 11 strains of E. coli responsible for biofilm production, all of which showed a higher concentration of polysaccharides than proteins in the matrix. Escherichia coli was considered the most prevalent bacterium among the samples, and S. aureus was determined to be the largest biofilm producer. The results of the CRA and microplate adhesion tests were similar in regard to identification of the biofilm-producing strains according to their phenotype and matrix composition. The classification of S. aureus strains as major biofilm producers is of great concern for producers, as such bacteria are considered one of the predominant contagious etiological agents that cause bovine mastitis. In addition, our observation that E. coli and S. epidermidis can produce biofilms highlights the need to reassess prophylactic measures to avoid the adhesion of biofilm-producing bacteria.

Isolation, Identification, and Evaluation of Novel Probiotic Strains Isolated from Feces of Breast-Fed Infants.

Science.gov (United States)

Panya, Marutpong; Lulitanond, Viraphong; Rattanachaikunsopon, Pongsak; Srivoramas, Thanyakarn; Chaiwong, Tarinee

2016-01-01

To isolate, identify, and evaluate the probiotic properties of lactic acid bacteria (LAB) isolated from the feces of breast-fed infants. The probiotic tests included investigation of hemolysis activity, survival in simulated gastrointestinal tract conditions (acid and bile salt tolerance), susceptibility to antibiotics, and ability to inhibit selected bacterial pathogens (Escherichia coli O157:H7, Vibrio cholerae and Salmonella enterica subsp enterica serovar Typhimurium). The bacterial species identification was performed by both carbohydrate utilization and partial 16S ribosomal RNA sequencing. Five of fifty LAB isolates (UBU-03, UBU-06, UBU-09, UBU-34, and UBU-37) showed good probiotic properties. These five isolates showed non-hemolysis type (gamma-hemolysis), susceptibility to all antibiotics tested except for vancomycin, ability to survive in the simulated gastrointestinal conditions of both acid and bile salt solution, and ability to inhibit growth of E. coli O157: H7 and V. cholerae. Bacterial species identification revealed that all five isolates were firmly identified as Lactobacillus rhamnosus species. The L. rhamnosus strains that were isolated and characterized in this study could be considered as probiotic strains, and then used for further probiotic characterization in human cell cultures or animal models.

The Genomic Sequence of the Oral Pathobiont Strain NI1060 Reveals Unique Strategies for Bacterial Competition and Pathogenicity.

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Youssef Darzi

Full Text Available Strain NI1060 is an oral bacterium responsible for periodontitis in a murine ligature-induced disease model. To better understand its pathogenicity, we have determined the complete sequence of its 2,553,982 bp genome. Although closely related to Pasteurella pneumotropica, a pneumonia-associated rodent commensal based on its 16S rRNA, the NI1060 genomic content suggests that they are different species thriving on different energy sources via alternative metabolic pathways. Genomic and phylogenetic analyses showed that strain NI1060 is distinct from the genera currently described in the family Pasteurellaceae, and is likely to represent a novel species. In addition, we found putative virulence genes involved in lipooligosaccharide synthesis, adhesins and bacteriotoxic proteins. These genes are potentially important for host adaption and for the induction of dysbiosis through bacterial competition and pathogenicity. Importantly, strain NI1060 strongly stimulates Nod1, an innate immune receptor, but is defective in two peptidoglycan recycling genes due to a frameshift mutation. The in-depth analysis of its genome thus provides critical insights for the development of NI1060 as a prime model system for infectious disease.

Temporary diplopia upon hyoscine-N-butyl bromide administration: case report

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Migliorini R

2013-05-01

Full Text Available R Migliorini, R Malagola, M Mafrici, R Spena, L ArricoDepartment of Sense Organs, University of Rome "La Sapienza", Rome, ItalyAbstract: Hyoscine-N-butyl bromide is a widely used antispasmodic belonging to the belladonna alkaloid class of semisynthetic quaternary ammonium compounds. These compounds exert a spasmolytic action on the smooth muscles of the bile-gastrointestinal tract, genitourinary tract, salivary glands (xerostomia, and also on the visual apparatus – in particular, the irido-ciliary complex. As a consequence, they provoke collateral effects such as mydriasis and accommodation disturbances. We report the case of a 23-year-old woman who complained of not only "dry mouth" but also "cloudy vision" and a "diplopia", both of temporary type, 2 hours after oral administration of hyoscine-N-butyl bromide.Keywords: hyoscine-N-butyl bromide, accommodation disorders, temporary diplopia, fusion alteration, vertical strabismus

Vaginal epithelial cells regulate membrane adhesiveness to co-ordinate bacterial adhesion

NARCIS (Netherlands)

Younes, Jessica A.; Klappe, Karin; Kok, Jan Willem; Busscher, Henk J.; Reid, Gregor; van der Mei, Henny C.

Vaginal epithelium is colonized by different bacterial strains and species. The bacterial composition of vaginal biofilms controls the balance between health and disease. Little is known about the relative contribution of the epithelial and bacterial cell surfaces to bacterial adhesion and whether

Methyl bromide residues in fumigated cocoa beans

International Nuclear Information System (INIS)

Adomako, D.

1975-01-01

The 14 C activity in unroasted [ 14 C]-methyl bromide fumigated cocoa beans was used to study the fate and persistence of CH 3 Br in the stored beans. About 70% of the residues occurred in the shells. Unchanged CH 3 Br could not be detected, all the sorbed CH 3 Br having reacted with bean constituents apparently to form 14 C-methylated derivatives and inorganic bromide. No 14 C activity was found in the lipid fraction. Roasting decreased the bound (non-volatile) residues, with corresponding changes in the activities and amounts of free sugars, free and protein amino acids. Roasted nibs and shells showed a two-fold increase in the volatile fraction of the 14 C residue. This fraction may be related to the volatile aroma compounds formed by Maillard-type reactions. (author)

Uptake of ozone to mixed sodium bromide/ citric acid solutions

Science.gov (United States)

Lee, Ming-Tao; Steimle, Emilie; Bartels-Rausch, Thorsten; Kato, Shunsuke; Lampimäki, Markus; Brown, Matthew; van Bokhoven, Jeroen; Nolting, Frithjof; Kleibert, Armin; Türler, Andreas; Ammann, Markus

2013-04-01

Sea-salt solution - air interfaces play an important role in the chemistry of the marine boundary layer. The reaction of ozone (O3) with bromide is of interest in the context of formation of photolabile halogens (Br2, BrCl) in the marine boundary layer. Recent experiments have suggested that the bromide oxidation rate is related to the surface concentration of bromide [1] and inversely related to the gas phase concentration of O3, an indication for a precursor mediated reaction at the surface [2]. So far, the effect of organics (such as those occurring at the ocean surface or in marine aerosols) on the reaction of O3 with bromide aerosols has not been studied yet. In our study we investigate the uptake kinetics of O3 to a mixed solution of sodium bromide (NaBr) and citric acid (CA), which represents highly oxidized organic compounds present in the environment, with a well-established coated wall flow tube technique, which leads to exposure of the film to O3 allowing the heterogeneous reactions to take place and the loss of O3 being measured. The results indicate that the uptake of O3 to the films with the higher bromide concentrations (0.34M and 4M) is independent of the gas phase concentration and roughly consistent with uptake limited by reaction in the bulk. For the lower bromide concentration (84mM), however, we observe a trend of the uptake coefficient to decrease with increasing O3 concentration, indicating an increasing importance of a surface reaction. In an attempt to constrain the kinetic data, we employed X-ray photoelectron spectroscopy (XPS) to get insight into the surface composition of the aqueous solution - air interface. Previous XPS studies have shown that halide ion concentrations are enhanced at the aqueous solution air interface [3-4], which likely promotes the surface reactions of bromide or iodide with O3. A first XPS study of ternary solutions of KI with butanol indicated the importance of specific interactions of the cation with the alcohol

Field-scale transport of water and bromide in a cracking clay soil

NARCIS (Netherlands)

Hendriks, R.F.A.; Hamminga, W.; Oostindie, K.; Bronswijk, J.J.B.

1995-01-01

The transport of a bromide tracer was studied in a cracking heavy clay soil. The soil was sampled six times and the groundwater and drain discharge were sampled frequently. Samples were analysed for bromide content. Solutes were transported in three domains: macropores, such as large continuous

Thermochromatic investigation of some bromides and comparison with the corresponding chlorides

International Nuclear Information System (INIS)

Kim U Zin; Timokhin, S.N.; Zvara, I.

1988-01-01

The thermochromatographic behaviour of chlorides and bromides of La, Tb, Ag, Mn, Cs, Zn, Au, Zr, Hf, Nb ('carrier-free' nuclides) in quartz column was studied. From the experimental data a correlation was observed between the deposition temperature on the column and the enthalpy of sublimation of the chlorides and bromides. The enthalpy of adsortion of the halides were also evaluated. (author)

Chloride/bromide ratios in leachate derived from farm-animal waste

International Nuclear Information System (INIS)

Hudak, P.F.

2003-01-01

Results have important implications for identifying animal sources of contaminated groundwater. - Ratios of conservative chemicals have been used to identify sources of groundwater contamination. While chloride/bromide ratios have been reported for several common sources of groundwater contamination, little work has been done on leachate derived from farm-animal waste. In this study, chloride/bromide ratios were measured in leachate derived from longhorn-cattle, quarter-horse, and pygme-goat waste at a farm in Abilene, Texas, USA. (Minimum, median, and maximum) chloride/bromide ratios of (66.5, 85.6, and 167), (119, 146, and 156), and (35.4, 57.8, and 165) were observed for cattle, horses, and goats, respectively. These ratios are below typical values for domestic wastewater and within the range commonly observed for oilfield brine. Results of this study have important implications for identifying sources of contaminated groundwater in settings with significant livestock and/or oil production

Synthesis and Characterization of Cefotaxime Conjugated Gold Nanoparticles and Their Use to Target Drug-Resistant CTX-M-Producing Bacterial Pathogens.

Science.gov (United States)

Shaikh, Sibhghatulla; Rizvi, Syed Mohd Danish; Shakil, Shazi; Hussain, Talib; Alshammari, Thamir M; Ahmad, Waseem; Tabrez, Shams; Al-Qahtani, Mohammad H; Abuzenadah, Adel M

2017-09-01

Multidrug-resistance due to "β lactamases having the expanded spectrum" (ESBLs) in members of Enterobacteriaceae is a matter of continued clinical concern. CTX-M is among the most common ESBLs in Enterobacteriaceae family. In the present study, a nanoformulation of cefotaxime was prepared using gold nanoparticles to combat drug-resistance in ESBL producing strains. Here, two CTX-M-15 positive cefotaxime resistant bacterial strains (i.e., one Escherichia coli and one Klebsiella pneumoniae strain) were used for testing the efficacy of "cefotaxime loaded gold-nanoparticles." Bromelain was used for both reduction and capping in the process of synthesis of gold-nanoparticles. Thereafter, cefotaxime was conjugated onto it with the help of activator 1-Ethyl-3-(3-dimethylaminopropyl)-carbodiimide. For characterization of both unconjugated and cefotaxime conjugated gold nanoparticles; UV-Visible spectroscopy, Scanning, and Transmission type Electron Microscopy methods accompanied with Dynamic Light Scattering were used. We used agar diffusion method plus microbroth-dilution method for the estimation of the antibacterial-activity and determination of minimum inhibitory concentration or MIC values, respectively. MIC values of cefotaxime loaded gold nanoparticles against E. coli and K. pneumoniae were obtained as 1.009 and 2.018 mg/L, respectively. These bacterial strains were completely resistant to cefotaxime alone. These results reinforce the utility of conjugating an old unresponsive antibiotic with gold nanoparticles to restore its efficacy against otherwise resistant bacterial pathogens. J. Cell. Biochem. 118: 2802-2808, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Methods for analysis of bacterial autoinducer-2 production.

Science.gov (United States)

Taga, Michiko E

2005-07-01

The quorum-sensing signal molecule autoinducer-2 (AI-2) is produced by over 50 diverse bacterial species and controls many different processes, including antibiotic production, biofilm formation, and virulence. AI-2 production often varies according to growth phase, media conditions, and the presence of specific factors. This unit describes a biological assay for AI-2 activity produced by a bacterial strain of interest. The assay employs an AI-2 reporter strain, Vibrio harveyi BB170, which produces light in response to AI-2. In the first stage of the assay, culture fluids of the bacterial strain of interest are collected over a time course of growth and filtered to remove cells. In the next stage, these culture fluids are mixed with BB170, and the light produced in response to AI-2 in the culture fluids is measured using a luminometer. BB170 is exquisitely sensitive to AI-2, and therefore, even low amounts of AI-2 can be detected using this bioassay.

Application of vacuum membrane distillation to lithium bromide absorption refrigeration system

Energy Technology Data Exchange (ETDEWEB)

Wang, Zanshe; Feng, Shiyu; Li, Yun [School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Gu, Zhaolin [School of Human Settlement and Civil Engineering, Xi' an Jiaotong University, Xi' an 710049 (China)

2009-11-15

Conventional generator in lithium bromide absorption refrigeration system is too bulky and heavy to be fitted into small scale device, and the temperature of the driving heater in the generator seems much higher than low grade energy such as regenerative energy or waste heat energy. In this paper, desorption of aqueous lithium bromide solution by vacuum membrane distillation process was presented. Hollow fiber membrane module made by polyvinylidene fluoride was used as desorption device of aqueous lithium bromide solution. Influencing factors of feed flux, feed temperature in lumen side and vacuum pressure in shell side were tested and analyzed with orthogonal test. The results showed that permeation flux of water vapor increased with the feed temperature increasing and the feed flux increasing in lumen side, and the permeation flux also went up along with absolute pressure drop in shell side. Feasibility and potential application analysis shows that the temperature of the driving heat was low and the volume and weight of the desorption device was light. In this study, vacuum membrane distillation to the lithium bromide absorption refrigeration system has proved to be an efficient and cheap desorption mode. (author)

First Stabilization and Disposal of Radioactive Zinc Bromide at the SRS

International Nuclear Information System (INIS)

Denny, J.K.

2003-01-01

Facilities Disposition Projects (FDP) personnel at Savannah River Site (SRS) implement the Inactive Facility Risk Management Program to drive down risk and costs in SRS inactive facilities. The program includes cost-effective techniques to identify and dispose of hazardous chemicals and radioactive waste from inactive facilities, thereby ensuring adequate protection of the public, workers and the environment. In June 1998, FDP conducted an assessment of the inactive C-Reactor Facility to assure that chemical and radiological hazards had been identified and were being safely managed. The walkdown identified the need to mitigate a significant hazard associated with storing approximately 13,400 gallons of liquid radioactive Zinc Bromide in three aging railcar tankers outside of the facility. No preventive maintenance was being performed on the rusting tankers and a leak could send radioactive Zinc Bromide into an outfall and offsite to the Savannah River. In 2001, DOE-Savannah River (DOE- SR) funded the FDP to eliminate the identified hazard by disposing of the radioactive Zinc Bromide solution and the three contaminated railcar tankers. This paper describes the innovative, cost-effective approaches and technology used to perform the first stabilization and disposal of radioactive Zinc Bromide at SRS

Corn cob biochar increases soil culturable bacterial abundance without enhancing their capacities in utilizing carbon sources in Biolog Eco-plates

Institute of Scientific and Technical Information of China (English)

JIANG Lin-lin; HAN Guang-ming; LAN Yu; LIU Sai-nan; GAO Ji-ping; YANG Xu; MENG Jun; CHEN Wen-fu

2017-01-01

Biochar has been shown to influence soil microbial communities in terms of their abundance and diversity.However,the relationship among microbial abundance,structure and C metabolic traits is not well studied under biochar application.Here it was hypothesized that the addition of biochar with intrinsic properties (i.e.,porous structure) could affect the proliferation of culturable microbes and the genetic structure of soil bacterial communities.In the meantime,the presence of available organic carbon in biochar may influence the C utilization capacities of microbial community in Biolog Eco-plates.A pot experiment was conducted with differenct biochar application (BC) rates:control (0 t ha-1),BC1 (20 t ha-1) and BC2 (40 t ha-1).Culturable microorganisms were enumerated via the plate counting method.Bacterial diversity was examined using denaturing gradient gel electrophoresis (DGGE).Microbial capacity in using C sources was assessed using Biolog Eco-plates.The addition of biochar stimulated the growth of actinomyces and bacteria,especially the ammonifying bacteria and azotobacteria,but had no significant effect on fungi proliferation.The phylogenetic distribution of the operational taxonomic units could be divided into the following groups with the biochar addition:Firmicutes,Acidobacteria,Gemmatimonadetes,Actinobacteria,Cyanobacteria and α-,β-,γ-and δ-Proteobacteria (average similarity ＞95％).Biochar application had a higher capacity utilization for L-asparagine,Tween 80,D-mannitol,L-serine,γ-hydroxybutyric acid,N-acetyI-D-glucosamine,glycogen,itaconic acid,glycyl-L-glutamic acid,α-ketobutyricacid and putrescine,whereas it had received decreased capacities in using the other 20 carbon sources in Biolog Eco-plates.Redundancy analysis (RDA) revealed that the physico-chemical properties,indices of bacterial diversity,and C metabolic traits were positively correlated with the appearance of novel sequences under BC2 treatment.Our study indicates that the

DNA microarray-based genome comparison of a pathogenic and a nonpathogenic strain of Xylella fastidiosa delineates genes important for bacterial virulence.

Science.gov (United States)

Koide, Tie; Zaini, Paulo A; Moreira, Leandro M; Vêncio, Ricardo Z N; Matsukuma, Adriana Y; Durham, Alan M; Teixeira, Diva C; El-Dorry, Hamza; Monteiro, Patrícia B; da Silva, Ana Claudia R; Verjovski-Almeida, Sergio; da Silva, Aline M; Gomes, Suely L

2004-08-01

Xylella fastidiosa is a phytopathogenic bacterium that causes serious diseases in a wide range of economically important crops. Despite extensive comparative analyses of genome sequences of Xylella pathogenic strains from different plant hosts, nonpathogenic strains have not been studied. In this report, we show that X. fastidiosa strain J1a12, associated with citrus variegated chlorosis (CVC), is nonpathogenic when injected into citrus and tobacco plants. Furthermore, a DNA microarray-based comparison of J1a12 with 9a5c, a CVC strain that is highly pathogenic and had its genome completely sequenced, revealed that 14 coding sequences of strain 9a5c are absent or highly divergent in strain J1a12. Among them, we found an arginase and a fimbrial adhesin precursor of type III pilus, which were confirmed to be absent in the nonpathogenic strain by PCR and DNA sequencing. The absence of arginase can be correlated to the inability of J1a12 to multiply in host plants. This enzyme has been recently shown to act as a bacterial survival mechanism by down-regulating host nitric oxide production. The lack of the adhesin precursor gene is in accordance with the less aggregated phenotype observed for J1a12 cells growing in vitro. Thus, the absence of both genes can be associated with the failure of the J1a12 strain to establish and spread in citrus and tobacco plants. These results provide the first detailed comparison between a nonpathogenic strain and a pathogenic strain of X. fastidiosa, constituting an important step towards understanding the molecular basis of the disease.

Isolation and partial characterization of a new strain of Klebsiella pneumoniae capable of high 1,3 propanediol production from glycerol

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B. Sen

2015-04-01

Full Text Available Glycerol is a promising feedstock for microbial cultivation and production of 1,3 propanediol (1,3 PDO. Here we report a newly isolated bacterial strain BA11 from soil, capable of fermenting glycerol to 1,3 PDO, and has been identified to be a strain of Klebsiella pneumoniae. Strain BA11 was fast growing showing peak 1,3 PDO production in 6 h of cultivation with productivity of 1.2 g/L-h without the addition of Vitamin B12. Based on the optimum glycerol utilization (75% and 1,3 PDO production (8.3 g/L and yield (0.56 mol/mol glycerol utilized, the most appropriate glycerol concentration for cultivation was 20 g/L. The strain BA11 could tolerate the pH range of 6 to 8.5 as no inhibitory effects were seen on growth as well as 1,3 PDO production. Strain BA11 was most active and could produce high 1,3 PDO in the incubation temperature range of 25 to 40 oC. The production of 1,3 PDO was maximum (9.3 g/L under aerobic condition with 95.8% glycerol utilization. Addition of glucose to the glycerol fermentation led to increased cell mass but no improvement in the 1,3 PDO production.

Stabilized thallium bromide radiation detectors and methods of making the same

Science.gov (United States)

Leao, Cedric Rocha; Lordi, Vincenzo

2015-11-24

According to one embodiment, a crystal includes thallium bromide (TlBr), one or more positively charged dopants, and one or more negatively charged dopants. According to another embodiment, a system includes a monolithic crystal including thallium bromide (TlBr), one or more positively charged dopants, and one or more negatively charged dopants; and a detector configured to detect a signal response of the crystal.

Biodegradation of phenol and benzene by endophytic bacterial strains isolated from refinery wastewater-fed Cannabis sativa.

Science.gov (United States)

Iqbal, Aneela; Arshad, Muhammad; Hashmi, Imran; Karthikeyan, Raghupathy; Gentry, Terry J; Schwab, Arthur Paul

2017-06-13

The presence of benzene and phenol in the environment can lead to serious health effects in humans and warrant development of efficient cleanup strategies. The aim of the present work was to assess the potential of indigenous endophytic bacterial strains to degrade benzene and phenol. Seven strains were successfully isolated from Cannabis sativa plants irrigated with oil refinery wastewater. Molecular characterization was performed by 16S rRNA gene sequencing. Phenol was biodegraded almost completely with Achromobacter sp. (AIEB-7), Pseudomonas sp. (AIEB-4), and Alcaligenes sp. (AIEB-6) at 250, 500, and 750 mg L -1 ; however, the degradation was only 81%, 72%, and 69%, respectively, when exposed to 1000 mg L -1 . Bacillus sp. (AIEB-1), Enterobacter sp. (AIEB-3), and Acinetobacter sp. (AIEB-2) degraded benzene significantly at 250, 500, and 750 mg L -1 . However, these strains showed 80%, 72%, and 68% benzene removal at 1000 mg L -1 exposure, respectively. Rates of degradation could be modeled with first-order kinetics with rate constant values of 1.86 × 10 -2 for Pseudomonas sp. (AIEB-4) and 1.80 × 10 -2  h -1 for Bacillus sp. (AIEB-1) and half-lives of 1.5 and 1.6 days, respectively. These results establish a foundation for further testing of the phytoremediation of hydrocarbon-contaminated soils in the presence of these endophytic bacteria.

Antimicrobial and Anti-Swarming Effects of Bacteriocins and Biosurfactants from Probiotic Bacterial Strains against Proteus spp.

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Laila Goudarzi

2017-02-01

Full Text Available Background:   Proteus spp. belongs to the family of Enterobacteriaceae. These bacteria are Gram-negative and motile microorganisms and known as the third most common causes of urinary tract infections. The aim of the current study was to investigate the effects of some secondary metabolites from probiotic strains of Lactobacillus spp. on swarming and growth of Proteus mirabilis and P. vulgaris. Methods:   After determination of optimal conditions for the growth and production of antimicrobials, bacteriocins and biosurfactants were partially purified from Lactobacillus culture supernatants. Then, effects of the purified compounds on growth and swarming migration of Proteus spp. were examined in the presence of various concentrations of semi-purified compounds. Results:  Results showed that the partially purified bacteriocins inhibited Proteus spp. swarming distance and had a significant reduction on the bacterial growth curves. Biosurfactants in a solvent form did not have any considerable effects on factors produced by Proteus spp. Conclusion:  According to the results, the secondary metabolites, especially bacteriocins or bacteriocin-like substances derived from Lactobacillus strains, can inhibit or reduce growth and swarming migration of Proteus spp. which are considered as the bacteria major virulence factors.

SYBR safeTM efficiently replaces ethidium bromide in Aspergillus fumigatus gene disruption.

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Canela, H M S; Takami, L A; Ferreira, M E S

2017-02-08

Invasive aspergillosis is a disease responsible for high mortality rates, caused mainly by Aspergillus fumigatus. The available drugs are limited and this disease continues to occur at an unacceptable frequency. Gene disruption is essential in the search for new drug targets. An efficient protocol for A. fumigatus gene disruption was described but it requires ethidium bromide, a genotoxic agent, for DNA staining. Therefore, the present study tested SYBR safe TM , a non-genotoxic DNA stain, in A. fumigatus gene disruption protocol. The chosen gene was cipC, which has already been disrupted successfully in our laboratory. A deletion cassette was constructed in Saccharomyces cerevisiae and used in A. fumigatus transformation. There was no statistical difference between the tested DNA stains. The success rate of S. cerevisiae transformation was 63.3% for ethidium bromide and 70% for SYBR safe TM . For A. fumigatus gene disruption, the success rate for ethidium bromide was 100 and 97% for SYBR safe TM . In conclusion, SYBR safe TM efficiently replaced ethidium bromide, making this dye a safe and efficient alternative for DNA staining in A. fumigatus gene disruption.

Optimization of endoglucanase production from thermophilic strain of Bacillus licheniformis RT-17 and its application for saccharification of sugarcane bagasse

International Nuclear Information System (INIS)

Tariq, R.; Qadir, F.; Ahmed, A.; Shariq, M.; Zafar, U.; Khan, S.A.

2018-01-01

Thermostable cellulases are required for a variety of commercial processes. Bacillus is a house of thermostable proteins. Screening of indigenously isolated strains of bacteria revealed the promising production of cellulase by a strain, RT-17, at 50 degree C. The strain was identified on the basis of biochemical and molecular characteristics as B. licheniformis. The factors affecting cellulase production from B. licheniformis RT-17 were evaluated for their significant effect using Plackett Burman Design and were optimized by employing Box-Behnken Design. The model predicted 9.808 IU/ml of endoglucanase (EG) under optimum conditions of 50 degree C; 10% inoculum size; pH 5; and 1% peptone in fermentation medium. Practically, a titer of 9.128 IU/ml was obtained, showed the validity of the model. The enzyme preparation from B. licheniformis RT-17 was applied in combination with xylanase and pectinase preparations from indigenous yeasts for the hydrolysis of sugarcane bagasse (SCB). A higher degree of synergy (7.1 folds) was observed when yeast pectinase was used with bacterial cellulase for the hydrolysis of alkali treated SCB. Whereas, the degree of synergy was lower when bacterial cellulase was mixed with yeast xylanase. The study revealed the possibility of utilization of combination of yeast and bacterial enzymes for biomass saccharification. (author)

Enzymes produced by halotolerant spore-forming gram-positive bacterial strains isolated from a resting habitat (Restinga de Jurubatiba) in Rio de Janeiro, Brazil: focus on proteases.

Science.gov (United States)

D Santos, Anderson Fragoso; Pacheco, Clarissa Almeida; Valle, Roberta D Santos; Seldin, Lucy; D Santos, André Luis Souza

2014-12-01

The screening for hydrolases-producing, halotolerant, and spore-forming gram-positive bacteria from the root, rhizosphere, and non-rhizosphere soil of Blutaparon portulacoides, a plant found in the Restinga de Jurubatiba located at the northern region of Rio de Janeiro State, Brazil, resulted in the isolation of 22 strains. These strains were identified as Halobacillus blutaparonensis (n = 2), Oceanobacillus picturae (n = 5), and Oceanobacillus iheyensis (n = 15), and all showed the ability to produce different extracellular enzymes. A total of 20 isolates (90.9 %) showed activity for protease, 5 (22.7 %) for phytase, 3 (13.6 %) for cellulase, and 2 (9.1 %) for amylase. Some bacterial strains were capable of producing three (13.6 %) or two (9.1 %) distinct hydrolytic enzymes. However, no bacterial strain with ability to produce esterase and DNase was observed. The isolate designated M9, belonging to the species H. blutaparonensis, was the best producer of protease and also yielded amylase and phytase. This strain was chosen for further studies regarding its protease activity. The M9 strain produced similar amounts of protease when grown either without or with different NaCl concentrations (from 0.5 to 10 %). A simple inspection of the cell-free culture supernatant by gelatin-sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed the presence of three major alkaline proteases of 40, 50, and 70 kDa, which were fully inhibited by phenylmethylsulfonyl fluoride (PMSF) and tosyl-L-phenylalanine chloromethyl ketone (TPCK) (two classical serine protease inhibitors). The secreted proteases were detected in a wide range of temperature (from 4 to 45 °C) and their hydrolytic activities were stimulated by NaCl (up to 10 %). The serine proteases produced by the M9 strain cleaved gelatin, casein, albumin, and hemoglobin, however, in different extensions. Collectively, these results suggest the potential use of the M9 strain in biotechnological

Vaginal epithelial cells regulate membrane adhesiveness to co-ordinate bacterial adhesion.

Science.gov (United States)

Younes, Jessica A; Klappe, Karin; Kok, Jan Willem; Busscher, Henk J; Reid, Gregor; van der Mei, Henny C

2016-04-01

Vaginal epithelium is colonized by different bacterial strains and species. The bacterial composition of vaginal biofilms controls the balance between health and disease. Little is known about the relative contribution of the epithelial and bacterial cell surfaces to bacterial adhesion and whether and how adhesion is regulated over cell membrane regions. Here, we show that bacterial adhesion forces with cell membrane regions not located above the nucleus are stronger than with regions above the nucleus both for vaginal pathogens and different commensal and probiotic lactobacillus strains involved in health. Importantly, adhesion force ratios over membrane regions away from and above the nucleus coincided with the ratios between numbers of adhering bacteria over both regions. Bacterial adhesion forces were dramatically decreased by depleting the epithelial cell membrane of cholesterol or sub-membrane cortical actin. Thus, epithelial cells can regulate membrane regions to which bacterial adhesion is discouraged, possibly to protect the nucleus. © 2015 John Wiley & Sons Ltd.

Biodegradation of carcinogenic textile azo dyes using bacterial isolates of mangrove sediment

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Guru Prasad Srinivasan

2014-02-01

Full Text Available Objective: To evaluate the biodegrading property against carcinogenic azo dyes using bacterial isolates of mangrove sediment. Methods: The bacterial isolates were subjected to submerged fermentation and their growth kinetics were studied. The potential strain was characterized using 16S rDNA sequencing. Results: In the present study, dye degrading bacterial colonies were isolated from the mangrove sediment samples of Parangipettai estuarine area, Tamil Nadu. Of the 30 morphologically different strains isolated, 5 showed antagonistic property. The growth kinetics of the two strains, P1 and G1, which showed potent activity were calculated. One particular isolate (P1 showing promising dye degrading potential in the submerged fermentation was further characterized. The strain was identified as Paenibacillus sp. by 16S rDNA sequencing. Conclusions: This study reveals the less explored microflora of mangrove sediments. The novel strain may further be analyzed and used in the treatment of effluent from dye industry so as to reduce the impact of carcinogenic contaminants.

Identification of electrode respiring, hydrocarbonoclastic bacterial strain Stenotrophomonas maltophilia MK2 highlights the untapped potential for environmental bioremediation

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Krishnaveni Venkidusamy

2016-12-01

Full Text Available Electrode respiring bacteria (ERB possess a great potential for many biotechnological applications such as microbial electrochemical remediation systems (MERS because of their exoelectrogenic capabilities to degrade xenobiotic pollutants. Very few ERB have been isolated from MERS, those exhibited a bioremediation potential towards organic contaminants. Here we report once such bacterial strain, Stenotrophomonas maltophilia MK2, a facultative anaerobic bacterium isolated from a hydrocarbon fed MERS, showed a potent hydrocarbonoclastic behavior under aerobic and anaerobic environments. Distinct properties of the strain MK2 were anaerobic fermentation of the amino acids, electrode respiration, anaerobic nitrate reduction and the ability to metabolize n-alkane components (C8-C36 of petroleum hydrocarbons including the biomarkers, pristine and phytane. The characteristic of diazoic dye decolorization was used as a criterion for pre-screening the possible electrochemically active microbial candidates. Bioelectricity generation with concomitant dye decolorization in MERS showed that the strain is electrochemically active. In acetate fed microbial fuel cells, maximum current density of 273±8 mA/m2 (1000Ω was produced (power density 113±7 mW/m2 by strain MK2 with a coulombic efficiency of 34.8 %. Further, the presence of possible alkane hydroxylase genes (alkB and rubA in the strain MK2 indicated that the genes involved in hydrocarbon degradation are of diverse origin. Such observations demonstrated the potential of facultative hydrocarbon degradation in contaminated environments. Identification of such a novel petrochemical hydrocarbon degrading ERB is likely to offer a new route to the sustainable bioremedial process of source zone contamination with simultaneous energy generation through MERS.

Antibacterial activity of curcuma long varieties against different strains of bacteria

International Nuclear Information System (INIS)

Naz, S.; Jabeen, S.; Ilyas, S.; Aslam, F.; Manzoor, F.; Ali, A.

2010-01-01

Crude extracts of curcuminoids and essential oil of Curcuma long varieties Kasur, Faisalabad and Bannu were studied for their antibacterial activity against 4 bacterial strains viz., Bacillus subtilis, Bacillus macerans, Bacillus licheniformis and Azotobacter using agar well diffusion method. Solvents used to determine antibacterial activity were ethanol and methanol. Ethanol was used for the extraction of curcuminoids. Essential oil was extracted by hydrodistillation and diluted in methanol by serial dilution method. Both Curcuminoids and oil showed zone of inhibition against all tested strains of bacteria. Among all the three turmeric varieties, Kasur variety had the most inhibitory effect on the growth of all bacterial strains tested as compared to Faisalabad and Bannu varieties. Among all the bacterial strains B. subtilis was the most sensitive to turmeric extracts of curcuminoids and oil. The MIC value for different strains and varieties ranged from 3.0 to 20.6 mm in diameter. (author)

Thin-layer chromatographic technique for rapid detection of bacterial phospholipases.

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Legakis, N J; Papavassiliou, J

1975-11-01

Silica gel thin-layer chromatography was employed to detect lecithinase activity induced from bacterial resting cell preparations induced from bacterial resting cell preparations incubated at 37 C for 4 h in the presence of purified egg yolk lecithin. Bacillus subtilis, Bacillus cereus, Serratia marcescens, and Pseudomonas aeruginosa hydrolyzed lecithin with the formation of free fatty acids as the sole lipid-soluble product. In none of the Escherichia coli and Citrobacter freundii strains tested could lecithinase activity be detected. Four among eight strains of Enterobacter aerogenes and one among 12 strains of Proteus tested produced negligible amounts of free fatty acid.

Identifikasi Brucella abortus Isolat Lokal dengan Brucella abortus Strain Specific-Polymerase Chain Reaction (IDENTIFICATION OF LOCAL ISOLATES OF BRUCELLA ABORTUS USING BRUCELLA ABORTUS STRAIN SPECIFIC-POLYMERASE CHAIN REACTION ASSAY

Directory of Open Access Journals (Sweden)

Susan Maphilindawati Noor

2014-10-01

Full Text Available Brucella abortus Strain Specific-Polymerase Chain Reaction (BaSS-PCR is a single multiplex PCRtechnique which able to identify and differentiate between Brucella abortus field strains (biovar 1, 2, and4, B. abortus vaccine strains, Brucella species, and non-Brucella species. In this study, BaSS-PCR wasapplied to identify local isolates of B. abortus in order to investigate the B. abortus strains that infectedcattle in Indonesia. Fifty local strains of B.abortus isolated from infected cattle in Java (Jakarta andBandung, South Sulawesi (Maros, East Nusa Tenggara (Kupang and Belu were used in this study. TheDNA bands were observed by agarose gel in the presence of ethidium bromide. Identification was performedbased on the size and number of DNA products amplified by PCR from each isolates. The results showedthat the 50 isolates were of B. abortus field strains. This finding showed that the cause of bovine brucellosisin Indonesia is B. abortus field strains.

An Inducible Operon Is Involved in Inulin Utilization in Lactobacillus plantarum Strains, as Revealed by Comparative Proteogenomics and Metabolic Profiling.

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Buntin, Nirunya; Hongpattarakere, Tipparat; Ritari, Jarmo; Douillard, François P; Paulin, Lars; Boeren, Sjef; Shetty, Sudarshan A; de Vos, Willem M

2017-01-15

The draft genomes of Lactobacillus plantarum strains isolated from Asian fermented foods, infant feces, and shrimp intestines were sequenced and compared to those of well-studied strains. Among 28 strains of L. plantarum, variations in the genomic features involved in ecological adaptation were elucidated. The genome sizes ranged from approximately 3.1 to 3.5 Mb, of which about 2,932 to 3,345 protein-coding sequences (CDS) were predicted. The food-derived isolates contained a higher number of carbohydrate metabolism-associated genes than those from infant feces. This observation correlated to their phenotypic carbohydrate metabolic profile, indicating their ability to metabolize the largest range of sugars. Surprisingly, two strains (P14 and P76) isolated from fermented fish utilized inulin. β-Fructosidase, the inulin-degrading enzyme, was detected in the supernatants and cell wall extracts of both strains. No activity was observed in the cytoplasmic fraction, indicating that this key enzyme was either membrane-bound or extracellularly secreted. From genomic mining analysis, a predicted inulin operon of fosRABCDXE, which encodes β-fructosidase and many fructose transporting proteins, was found within the genomes of strains P14 and P76. Moreover, pts1BCA genes, encoding sucrose-specific IIBCA components involved in sucrose transport, were also identified. The proteomic analysis revealed the mechanism and functional characteristic of the fosRABCDXE operon involved in the inulin utilization of L. plantarum The expression levels of the fos operon and pst genes were upregulated at mid-log phase. FosE and the LPXTG-motif cell wall anchored β-fructosidase were induced to a high abundance when inulin was present as a carbon source. Inulin is a long-chain carbohydrate that may act as a prebiotic, which provides many health benefits to the host by selectively stimulating the growth and activity of beneficial bacteria in the colon. While certain lactobacilli can catabolize

Towards Spectral Library-free MALDI-TOF MS Bacterial Identification.

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Cheng, Ding; Qiao, Liang; Horvatovich, Péter

2018-05-11

Bacterial identification is of great importance in clinical diagnosis, environmental monitoring and food safety control. Among various strategies, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has drawn significant interests, and has been clinically used. Nevertheless, current bioinformatics solutions use spectral libraries for the identification of bacterial strains. Spectral library generation requires acquisition of MALDI-TOF spectra from monoculture bacterial colonies, which is time-consuming and not possible for many species and strains. We propose a strategy for bacterial typing by MALDI-TOF using protein sequences from public database, i.e. UniProt. Ten genes were identified to encode proteins most often observed by MALD-TOF from bacteria through 500 times repeated a 10-fold double cross-validation procedure, using 403 MALDI-TOF spectra corresponding to 14 genera, 81 species and 403 strains, and the protein sequences of 1276 species in UniProt. The 10 genes were then used to annotate peaks on MALDI-TOF spectra of bacteria for bacterial identification. With the approach, bacteria can be identified at the genus level by searching against a database containing the protein sequences of 42 genera of bacteria from UniProt. Our approach identified 84.1% of the 403 spectra correctly at the genus level. Source code of the algorithm is available at https://github.com/dipcarbon/BacteriaMSLF.

A multi-channel bioluminescent bacterial biosensor for the on-line detection of metals and toxicity. Part I: design and optimization of bioluminescent bacterial strains

Energy Technology Data Exchange (ETDEWEB)

Charrier, Thomas; Durand, Marie-Jose; Jouanneau, Sulivan; Thouand, Gerald [UMR CNRS 6144 GEPEA, CBAC, Nantes University, PRES UNAM, Campus de la Courtaisiere-IUT, La Roche-sur-Yon cedex (France); Dion, Michel [UMR CNRS 6204, Nantes University, PRES UNAM, Biotechnologie, Biocatalyse, Bioregulation, 2, Rue de la Houssiniere, BP 92208, Nantes cedex 3 (France); Pernetti, Mimma; Poncelet, Denis [ONIRIS-ENITIAA, UMR CNRS GEPEA, Rue de la Geraudiere, BP 82225, Nantes cedex 3 (France)

2011-05-15

This study describes the construction of inducible bioluminescent strains via genetic engineering along with their characterization and optimization in the detection of heavy metals. Firstly, a preliminary comparative study enabled us to select a suitable carbon substrate from pyruvate, glucose, citrate, diluted Luria-Bertani, and acetate. The latter carbon source provided the best induction ratios for comparison. Results showed that the three constructed inducible strains, Escherichia coli DH1 pBzntlux, pBarslux, and pBcoplux, were usable when conducting a bioassay after a 14-h overnight culture at 30 C. Utilizing these sensors gave a range of 12 detected heavy metals including several cross-detections. Detection limits for each metal were often close to and sometimes lower than the European standards for water pollution. Finally, in order to maintain sensitive bacteria within the future biosensor-measuring cell, the agarose immobilization matrix was compared to polyvinyl alcohol (PVA). Agarose was selected because the detection limits of the bioluminescent strains were not affected, in contrast to PVA. Specific detection and cross-detection ranges determined in this study will form the basis of a multiple metals detection system by the new multi-channel Lumisens3 biosensor. (orig.)

Factors influencing production of lipase under metal supplementation by bacterial strain, Bacillus subtilis BDG-8.

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Dhevahi, B; Gurusamy, R

2014-11-01

Lipases are biocatalyst having wide applications in industries due to their versatile properties. In the present study, a lipolytic bacterial strain, Bacillus subtilis BDG-8 was isolated from an oil based industrial soil. The effect of selenium and nickel as a media supplement on enhancement of lipase production, was studied individually with the isolated strain by varying the concentration of selected metal. 60 μg l(-1) selenium enhanced lipase production to an enzyme activity measuring 7.8 U ml(-1) while 40 μgI(-1) nickel gave the maximum enzyme activity equivalent to 7.5 U ml(-1). However, nickel and selenium together at a range of concentration with an equal w/v ratio, at 60 μg l(-1) each, showed the maximum lipase activity of 8.5 U ml(-1). The effect of pH and temperature on lipase production showed maximum enzyme activity in the presence of each of the metals at pH 7 and 35°C among the other tested ranges. After optimisation of the parameters such as metal concentration, pH and temperature lipase production by Bacillus subtilis BDG-8 had increased several folds. This preliminary investigation may consequently lead as to various industrial applications such as treatment of wastewater contaminated with metal or oil with simultaneous lipase production.

Rocuronium Bromide Inhibits Inflammation and Pain by Suppressing Nitric Oxide Production and Enhancing Prostaglandin E2 Synthesis in Endothelial Cells.

Science.gov (United States)

Baek, Sang Bin; Shin, Mal Soon; Han, Jin Hee; Moon, Sang Woong; Chang, Boksoon; Jeon, Jung Won; Yi, Jae Woo; Chung, Jun Young

2016-12-01

Rocuronium bromide is a nondepolarizing neuromuscular blocking drug and has been used as an adjunct for relaxation or paralysis of the skeletal muscles, facilitation of endotracheal intubation, and improving surgical conditions during general anesthesia. However, intravenous injection of rocuronium bromide induces injection pain or withdrawal movement. The exact mechanism of rocuronium bromide-induced injection pain or withdrawal movement is not yet understood. We investigated whether rocuronium bromide treatment is involved in the induction of inflammation and pain in vascular endothelial cells. For this study, calf pulmonary artery endothelial (CPAE) cells were used, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, Western blot, nitric oxide detection, and prostaglandin E 2 immunoassay were conducted. Rocuronium bromide treatment inhibited endothelial nitric oxide synthase and suppressed nitric oxide production in CPAE cells. Rocuronium bromide activated cyclooxygenase-2, inducible nitric oxide synthase and increased prostaglandin E 2 synthesis in CPAE cells. Rocuronium bromide induced inflammation and pain in CPAE cells. Suppressing nitric oxide production and enhancing prostaglandin E 2 synthesis might be associated with rocuronium bromide-induced injection pain or withdrawal movement.

Comparison of phenobarbital with bromide as a first-choice antiepileptic drug for treatment of epilepsy in dogs.

Science.gov (United States)

Boothe, Dawn Merton; Dewey, Curtis; Carpenter, David Mark

2012-05-01

To compare efficacy and safety of treatment with phenobarbital or bromide as the first-choice antiepileptic drug (AED) in dogs. Double-blinded, randomized, parallel, clinical trial. 46 AED-naïve dogs with naturally occurring epilepsy. Study inclusion was based on age, history, findings on physical and neurologic examinations, and clinicopathologic test results. For either phenobarbital treatment (21 dogs) or bromide treatment (25), a 7-day loading dose period was initiated along with a maintenance dose, which was adjusted on the basis of monthly monitoring. Efficacy and safety outcomes were compared between times (baseline and study end [generally 6 months]) and between drugs. Phenobarbital treatment resulted in eradication of seizures (17/20 [85%]) significantly more often than did bromide (12/23 [52%]); phenobarbital treatment also resulted in a greater percentage decrease in seizure duration (88 ± 34%), compared with bromide (49 ± 75%). Seizure activity worsened in 3 bromide-treated dogs only. In dogs with seizure eradication, mean ± SD serum phenobarbital concentration was 25 ± 6 μg/mL (phenobarbital dosage, 4.1 ± 1.1 mg/kg [1.9 ± 0.5 mg/lb], p.o., q 12 h) and mean serum bromide concentration was 1.8 ± 0.6 mg/mL (bromide dosage, 31 ± 11 mg/kg [14 ± 5 mg/lb], p.o., q 12 h). Ataxia, lethargy, and polydipsia were greater at 1 month for phenobarbital-treated dogs; vomiting was greater for bromide-treated dogs at 1 month and study end. Both phenobarbital and bromide were reasonable first-choice AEDs for dogs, but phenobarbital was more effective and better tolerated during the first 6 months of treatment.

Physiological and biochemical characterization of Azospirillum brasilense strains commonly used as plant growth-promoting rhizobacteria.

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Di Salvo, Luciana P; Silva, Esdras; Teixeira, Kátia R S; Cote, Rosalba Esquivel; Pereyra, M Alejandra; García de Salamone, Inés E

2014-12-01

Azospirillum is a plant growth-promoting rhizobacteria (PGPR) genus vastly studied and utilized as agriculture inoculants. Isolation of new strains under different environmental conditions allows the access to the genetic diversity and improves the success of inoculation procedures. Historically, the isolation of this genus has been performed by the use of some traditional culture media. In this work we characterized the physiology and biochemistry of five different A. brasilense strains, commonly used as cereal inoculants. The aim of this work is to contribute to pose into revision some concepts concerning the most used protocols to isolate and characterize this bacterium. We characterized their growth in different traditional and non-traditional culture media, evaluated some PGPR mechanisms and characterized their profiles of fatty acid methyl esters and carbon-source utilization. This work shows, for the first time, differences in both profiles, and ACC deaminase activity of A. brasilense strains. Also, we show unexpected results obtained in some of the evaluated culture media. Results obtained here and an exhaustive knowledge revision revealed that it is not appropriate to conclude about bacterial species without analyzing several strains. Also, it is necessary to continue developing studies and laboratory techniques to improve the isolation and characterization protocols. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Comparative microvascular exchange kinetics of [{sup 77}Br]bromide and {sup 99m}Tc-DTPA in humans

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Cousins, Claire [Department of Clinical Radiology, Addenbrooke' s Hospital, Cambridge (United Kingdom); Skehan, Stephen J.; Rolph, Susan M.; Flaxman, Mary E.; Ballinger, James R.; Bird, Nicholas J.; Barber, Robert W.; Peters, Michael A. [Department of Nuclear Medicine, Addenbrooke' s Hospital, Cambridge (United Kingdom)

2002-05-01

The plasma clearance curves of small hydrophilic solutes comprise three exponentials, consistent with a three-compartmental distribution model. A previous comparison between inulin and diethylene triamine penta-acetic acid (DTPA) suggested that these three compartments are in series, the first being plasma and the second and third representing compartments within the extravascular space. Moreover, whilst the total distribution volumes of these two indicators were similar, the volume of the second compartment was higher for DTPA. The purpose of the current study was to investigate whether a solute smaller than DTPA, namely bromide, fits the hypothesis that the second space volume is an inverse function of the size of the solute. Two groups of subjects were studied: group A comprised eight patients undergoing routine diagnostic arteriography and group B, eight patients referred for routine measurement of glomerular filtration rate plus two normal volunteers. {sup 99m}Tc-DTPA and sodium [{sup 77}Br]bromide were intravenously administered simultaneously. In group A, frequent arterial samples were obtained up to 40 min after injection, and antecubital venous samples 30 s after each arterial sample. In group B, frequent venous samples were obtained up to 280 min after injection. Volume measurements based on bromide were corrected for erythrocyte bromide accumulation. In both subject groups, the normalised venous concentration ratio of bromide to DTPA, corrected for red cell bromide uptake, was significantly less than unity in the earliest blood samples, being 0.56 (SD 0.08) at 1 min, consistent with faster diffusion of bromide from plasma to interstitial fluid. Furthermore, the extraction fraction of bromide from plasma to interstitial fluid in the forearm was about 0.6, higher than that of DTPA (about 0.5) in spite of red cell bromide accumulation which equilibrated with plasma bromide within 20 s and resulted in a red cell to plasma concentration ratio of 0.51 (0

Development of copper bromide laser master oscillator power ...

Indian Academy of Sciences (India)

2014-02-09

Feb 9, 2014 ... Development of master oscillator power amplifier (MOPA) system of copper bromide laser (CBL) operating at ... The spectral distribution of power at .... It is evident from the voltage waveforms that the breakdown voltage drops.

Partial molar volume and isentropic compressibility of symmetrical and asymmetrical quaternary ammonium bromides in aqueous solution

International Nuclear Information System (INIS)

Moreno, Nicolás; Buchner, Richard; Vargas, Edgar F.

2015-01-01

Highlights: • Structural effects of the cations on surrounding water molecules are discussed. • Alkyl-chain geometry determines the hydration of Bu 4 N + isomers. • The “compactness” in the hydration shells varies significantly among the isomers. - Abstract: Values of apparent molar volume and isentropic compressibility of symmetric and asymmetric isomers of tetrabutylammonium bromide, namely tetra-n-butylammonium bromide, tetra-iso-butylammonium bromide, tetra-sec-butylammonium bromide, di-n-butyl-di-iso-butylammonium bromide and di-n-butyl-di-sec-butylammonium bromide, in aqueous solution were determined from density and speed of sound measurements. These properties were obtained as a function of molal concentration within the range of 0.01 < m/mol · kg −1 < 0.1 covering temperatures from 278.15 ⩽ T/K ⩽ 293.15. The partial molar volumes and the apparent isentropic molar compressibility at infinite dilution were calculated and their dependence on temperature examined. The results show that cations with sec-butyl chains have larger structural volumes compared to those with iso-butyl chains. In addition, cations with sec-butyl chains induce smaller structural changes in their hydration shell than the others

UTILIZATION OF PINE NEEDLES AS BED MATERIAL IN SOLID STATE FERMENTATION FOR PRODUCTION OF LACTIC ACID BY LACTOBACILLUS STRAINS

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Manoj Kumar Ghosh

Full Text Available Pine needles, which are abundantly found as underexploited biomass in coniferous forests, are responsible for fire hazards and air pollution. Utilization of pine needles as bed material in lactic acid production with solid state fermentation (SSF has been studied here. This investigation compared lactic acid production by pure strains of Lactobacilli, (1 L. delbrueckii (NCIM2025; (2 L. pentosus (NCIM 2912; (3 Lactobacillus sp. (NCIM 2734; (4 Lactobacillus sp. (NCIM2084; and a co-culture of the first two strains. The studies required 6 g per flask powdered dry pine needles as bed material, 2 g/L (inoculum, liquid production media based on pure glucose or whey substituted glucose, at 60, 80, and 120 g/L sugar levels, 37 oC, and an initial pH of 6.5. Co-culture attained a maximum lactic acid concentration of 45.10 g/L, followed by that of strain-1, 43.87 g/L and strain-4, 26.15 g/L, in 80 g/L pure glucose media. With 120g/L total sugar in whey-substituted media, the co-culture attained maximum lactic acid production of 44.88 g/L followed by that of strain-1, 43.67 g/L. The present experimental studies indicated better compatibility of pine needle bed with co-culture in solid state fermentation of lactic acid, which may prove to be an eco-friendly technology for utilization of biomass as well as minimizing fires in coniferous forests.

Formation of xylitol and xylitol-5-phosphate and its impact on growth of d-xylose-utilizing Corynebacterium glutamicum strains.

Science.gov (United States)

Radek, Andreas; Müller, Moritz-Fabian; Gätgens, Jochem; Eggeling, Lothar; Krumbach, Karin; Marienhagen, Jan; Noack, Stephan

2016-08-10

Wild-type Corynebacterium glutamicum has no endogenous metabolic activity for utilizing the lignocellulosic pentose d-xylose for cell growth. Therefore, two different engineering approaches have been pursued resulting in platform strains harbouring a functional version of either the Isomerase (ISO) or the Weimberg (WMB) pathway for d-xylose assimilation. In a previous study we found for C. glutamicum WMB by-product formation of xylitol during growth on d-xylose and speculated that the observed lower growth rates are due to the growth inhibiting effect of this compound. Based on a detailed phenotyping of the ISO, WMB and the wild-type strain of C. glutamicum, we here show that this organism has a natural capability to synthesize xylitol from d-xylose under aerobic cultivation conditions. We furthermore observed the intracellular accumulation of xylitol-5-phosphate as a result of the intracellular phosphorylation of xylitol, which was particularly pronounced in the C. glutamicum ISO strain. Interestingly, low amounts of supplemented xylitol strongly inhibit growth of this strain on d-xylose, d-glucose and d-arabitol. These findings demonstrate that xylitol is a suitable substrate of the endogenous xylulokinase (XK, encoded by xylB) and its overexpression in the ISO strain leads to a significant phosphorylation of xylitol in C. glutamicum. Therefore, in order to circumvent cytotoxicity by xylitol-5-phosphate, the WMB pathway represents an interesting alternative route for engineering C. glutamicum towards efficient d-xylose utilization. Copyright © 2016 Elsevier B.V. All rights reserved.

Methyl Bromide Commodity Fumigation Buffer Zone Lookup Tables

Science.gov (United States)

Product labels for methyl bromide used in commodity and structural fumigation include requirements for buffer zones around treated areas. The information on this page will allow you to find the appropriate buffer zone for your planned application.

Wpływ szczepów bakterii wyizolowanych z hydroponicznej uprawy sałaty (Lactuca sativa L. na wzrost siewek sałaty, rosnących w obecnosci rożnych form pożywienia azotowego [Influence of bacterial strains isolated from hydroponic cultures of lettuce (Lactuca sativa L. on the growth of lettuce seedlings growing in the presence of various forms of nitrogen nutrition

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Z. Kobierzyńska-Gołąb

2015-06-01

Full Text Available 320 bacterial strains isolated from the surface of cultivated plants, as well as from other parts of hydroponic cultures showed stimulating (49 bacterial strains or inhibitory (9 bacterial strains properties in respect to the investigated plant. The following bacteria were isolated: Pseudomonas, Flavobacterium, Agrobacterium, Achromobacter and Chromobacterium. The effects of active bacterial strains on the growth of seedlings were investigated in dependence on the kind of inorganic form of nitrogen present in the nutrient solutions. The same bacterial strains exerted a stimulating effect on seedlings growing on nitrates, weaker stimulation was observed in cultures with ammonium nitrate; the growth of lettuce seedlings on nutrient solution with ammonium only, was, as a rule, inhibited by the bacteria.

Bacteriophages for detection of bacterial pathogens

International Nuclear Information System (INIS)

Kutateladze, M.

2009-01-01

The G. Eliava Institute of Bacteriophages, Microbiology and Virology (Tbilisi, Georgia) is one of the most famous institutions focused on bacteriophage research for the elaboration of appropriate phage methodologies for human and animal protection. The main direction of the institute is the study and production of bacteriophages against intestinal disorders (dysentery, typhoid, intesti) and purulent-septic infections (staphylococcus, streptococcus, pyophage, etc.). These preparations were successfully introduced during the Soviet era, and for decades were used throughout the former Soviet Union and in other Socialist countries for the treatment, prophylaxis, and diagnosis of various infectious diseases, including those caused by antibiotic-resistant bacterial strains. Bacteriophages were widely used for identifying and detecting infections caused by the most dangerous pathogens and causative agents of epidemiological outbreaks. The specific topic of this presentation is the phage typing of bacterial species, which can be an important method for epidemiological diagnostics. Together with different genetic methodologies - such as PCR-based methods, PFGE, plasmid fingerprinting, and ribosomal typing - phage typing is one method for identifying bacterial pathogens. The method has a high percentage of determination of phage types, high specificity of reaction, and is easy for interpretation and use by health workers. Phage typing was applied for inter-species differentiation of different species of Salmonella, S. typhi, Brucella spp, Staphylococcus aureus, E. col,i Clostridium deficile, Vibrio cholerae, Yersinia pestis, Yersinia enterocolitica, Lysteria monocytogenes, Clostridium perfringens, Clostridium tetani, plant pathogens, and other bacterial pathogens. In addition to addressing the utility and efficacy of phage typing, the paper will discuss the isolation and selection of diagnostic typing phages for interspecies differentiation of pathogens that is necessary

Bacterial diversity in agricultural soils during litter decomposition

NARCIS (Netherlands)

Dilly, O.; Bloem, J.; Vos, A.; Munch, J.C.

2004-01-01

Denaturing gradient gel electrophoresis (DGGE) of amplified fragments of genes coding for 16S rRNA was used to study the development of bacterial communities during decomposition of crop residues in agricultural soils. Ten strains were tested, and eight of these strains produced a single band.

Residential proximity to methyl bromide use and birth outcomes in an agricultural population in California.

Science.gov (United States)

Gemmill, Alison; Gunier, Robert B; Bradman, Asa; Eskenazi, Brenda; Harley, Kim G

2013-06-01

Methyl bromide, a fungicide often used in strawberry cultivation, is of concern for residents who live near agricultural applications because of its toxicity and potential for drift. Little is known about the effects of methyl bromide exposure during pregnancy. We investigated the relationship between residential proximity to methyl bromide use and birth outcomes. Participants were from the CHAMACOS (Center for the Health Assessment of Mothers and Children of Salinas) study (n = 442), a longitudinal cohort study examining the health effects of environmental exposures on pregnant women and their children in an agricultural community in northern California. Using data from the California Pesticide Use Reporting system, we employed a geographic information system to estimate the amount of methyl bromide applied within 5 km of a woman's residence during pregnancy. Multiple linear regression models were used to estimate associations between trimester-specific proximity to use and birth weight, length, head circumference, and gestational age. High methyl bromide use (vs. no use) within 5 km of the home during the second trimester was negatively associated with birth weight (β = -113.1 g; CI: -218.1, -8.1), birth length (β = -0.85 cm; CI: -1.44, -0.27), and head circumference (β = -0.33 cm; CI: -0.67, 0.01). These outcomes were also associated with moderate methyl bromide use during the second trimester. Negative associations with fetal growth parameters were stronger when larger (5 km and 8 km) versus smaller (1 km and 3 km) buffer zones were used to estimate exposure. Residential proximity to methyl bromide use during the second trimester was associated with markers of restricted fetal growth in our study.

Metabolic Characteristics of a Glucose-Utilizing Shewanella oneidensis Strain Grown under Electrode-Respiring Conditions.

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Gen Nakagawa

Full Text Available In bioelectrochemical systems, the electrode potential is an important parameter affecting the electron flow between electrodes and microbes and microbial metabolic activities. Here, we investigated the metabolic characteristics of a glucose-utilizing strain of engineered Shewanella oneidensis under electrode-respiring conditions in electrochemical reactors for gaining insight into how metabolic pathways in electrochemically active bacteria are affected by the electrode potential. When an electrochemical reactor was operated with its working electrode poised at +0.4 V (vs. an Ag/AgCl reference electrode, the engineered S. oneidensis strain, carrying a plasmid encoding a sugar permease and glucose kinase of Escherichia coli, generated current by oxidizing glucose to acetate and produced D-lactate as an intermediate metabolite. However, D-lactate accumulation was not observed when the engineered strain was grown with a working electrode poised at 0 V. We also found that transcription of genes involved in pyruvate and D-lactate metabolisms was upregulated at a high electrode potential compared with their transcription at a low electrode potential. These results suggest that the carbon catabolic pathway of S. oneidensis can be modified by controlling the potential of a working electrode in an electrochemical bioreactor.

Protein design in systems metabolic engineering for industrial strain development.

Science.gov (United States)

Chen, Zhen; Zeng, An-Ping

2013-05-01

Accelerating the process of industrial bacterial host strain development, aimed at increasing productivity, generating new bio-products or utilizing alternative feedstocks, requires the integration of complementary approaches to manipulate cellular metabolism and regulatory networks. Systems metabolic engineering extends the concept of classical metabolic engineering to the systems level by incorporating the techniques used in systems biology and synthetic biology, and offers a framework for the development of the next generation of industrial strains. As one of the most useful tools of systems metabolic engineering, protein design allows us to design and optimize cellular metabolism at a molecular level. Here, we review the current strategies of protein design for engineering cellular synthetic pathways, metabolic control systems and signaling pathways, and highlight the challenges of this subfield within the context of systems metabolic engineering. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Capacitive-discharge-pumped copper bromide vapour laser

International Nuclear Information System (INIS)

Sukhanov, V B; Fedorov, V F; Troitskii, V O; Gubarev, F A; Evtushenko, Gennadii S

2007-01-01

A copper bromide vapour laser pumped by a high-frequency capacitive discharge is developed. It is shown that, by using of a capacitive discharge, it is possible to built a sealed off metal halide vapour laser of a simple design allowing the addition of active impurities into the working medium. (letters)

Revealing differences in metabolic flux distributions between a mutant strain and its parent strain Gluconacetobacter xylinus CGMCC 2955.

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Cheng Zhong

Full Text Available A better understanding of metabolic fluxes is important for manipulating microbial metabolism toward desired end products, or away from undesirable by-products. A mutant strain, Gluconacetobacter xylinus AX2-16, was obtained by combined chemical mutation of the parent strain (G. xylinus CGMCC 2955 using DEC (diethyl sulfate and LiCl. The highest bacterial cellulose production for this mutant was obtained at about 11.75 g/L, which was an increase of 62% compared with that by the parent strain. In contrast, gluconic acid (the main byproduct concentration was only 5.71 g/L for mutant strain, which was 55.7% lower than that of parent strain. Metabolic flux analysis indicated that 40.1% of the carbon source was transformed to bacterial cellulose in mutant strain, compared with 24.2% for parent strain. Only 32.7% and 4.0% of the carbon source were converted into gluconic acid and acetic acid in mutant strain, compared with 58.5% and 9.5% of that in parent strain. In addition, a higher flux of tricarboxylic acid (TCA cycle was obtained in mutant strain (57.0% compared with parent strain (17.0%. It was also indicated from the flux analysis that more ATP was produced in mutant strain from pentose phosphate pathway (PPP and TCA cycle. The enzymatic activity of succinate dehydrogenase (SDH, which is one of the key enzymes in TCA cycle, was 1.65-fold higher in mutant strain than that in parent strain at the end of culture. It was further validated by the measurement of ATPase that 3.53-6.41 fold higher enzymatic activity was obtained from mutant strain compared with parent strain.

Chemotaxis and degradation of organophosphate compound by a novel moderately thermo-halo tolerant Pseudomonas sp. strain BUR11: evidence for possible existence of two pathways for degradation

OpenAIRE

Pailan, Santanu; Saha, Pradipta

2015-01-01

An organophosphate (OP) degrading chemotactic bacterial strain BUR11 isolated from an agricultural field was identified as a member of Pseudomonas genus on the basis of its 16S rRNA gene sequence. The strain could utilize parathion, chlorpyrifos and their major hydrolytic intermediates as sole source of carbon for its growth and exhibited positive chemotactic response towards most of them. Optimum concentration of parathion for its growth was recorded to be 200 ppm and 62% of which was degrad...

GREEN CHEMISTRY APPLICATION FOR THE SYNTHESIS OF (1-N-4’-METHOXYBENZYL-1,10-PHENANTHROLINIUM BROMIDE

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Maulidan Firdaus

2010-06-01

Full Text Available A simple, energy-efficient, and relatively quick synthetic procedure for the synthesis of (1-N-4'-methoxybenzyl-1,10-phenanthrolinium bromide, based on green chemistry principles has been carried out. The synthesis was started by solvent-free reduction of p-anisaldehyde with NaBH4 to give 4-methoxybenzyl alcohol in 98% yield to be followed by solvent-free treatment of the resulted alcohol with PBr3 to yield 4-methoxybenzyl bromide (86%. Furthermore, the obtained bromide was reacted with 1,10-phenanthroline in acetone at reflux for 12 h to give the phenanthrolinium salt target in 68% yield.   Keywords: green chemistry, p-anisaldehyde, (1-N-4'-methoxybenzyl-1,10-phenanthrolinium bromide

Ease of intubation: A randomized, double-blind study to compare two doses of rocuronium bromide for endotracheal intubation.

Science.gov (United States)

Shukla, Aparna; Misra, Shilpi

2016-01-01

Clinical need for a nondepolarizing agent with a rapid onset time and a brief duration of action has led to the development of rocuronium bromide. The aim of this study was to evaluate optimal dose of rocuronium bromide for intubation and to compare the onset time, duration of action, intubating conditions, and hemodynamic effects of two doses of rocuronium bromide. A prospective, randomized, double-blind study. All the patients were divided in a randomized, double-blind fashion into two groups of twenty patients each. Group I patients received rocuronium bromide 0.6 mg/kg intravenously and intubated at 60 s, Group II patients received rocuronium bromide 0.9 mg/kg and intubated at 60 s. The neuromuscular block was assessed using single twitch stimulation of 0.1 Hz at adductor pollicis muscle of hand at every 10 s. The results were compiled and analyzed statistically using Chi-square test for qualitative data and Student's t -test for quantitative data. Time of onset was significantly shorter ( P Rocuronium bromide 0.9 mg/kg is a safer alternative to rocuronium bromide 0.6 mg/kg for endotracheal intubation with shorter time of onset and better intubating conditions.

Incorporation of Listeria monocytogenes strains in raw milk biofilms.

Science.gov (United States)

Weiler, Christiane; Ifland, Andrea; Naumann, Annette; Kleta, Sylvia; Noll, Matthias

2013-02-01

Biofilms develop successively on devices of milk production without sufficient cleaning and originate from the microbial community of raw milk. The established biofilm matrices enable incorporation of pathogens like Listeria monocytogenes, which can cause a continuous contamination of food processing plants. L. monocytogenes is frequently found in raw milk and non-pasteurized raw milk products and as part of a biofilm community in milk meters and bulk milk tanks. The aim of this study was to analyze whether different L. monocytogenes strains are interacting with the microbial community of raw milk in terms of biofilm formation in the same manner, and to identify at which stage of biofilm formation a selected L. monocytogenes strain settles best. Bacterial community structure and composition of biofilms were analyzed by a cloning and sequencing approach and terminal restriction fragment length polymorphism analysis (T-RFLP) based on the bacterial 16S rRNA gene. The chemical composition of biofilms was analyzed by Fourier transform infrared spectroscopy (FTIR), while settled L. monocytogenes cells were quantified by fluorescence in situ hybridization (FISH). Addition of individual L. monocytogenes strains to raw milk caused significant shifts in the biofilm biomass, in the chemical as well as in the bacterial community composition. Biofilm formation and attachment of L. monocytogenes cells were not serotype but strain specific. However, the added L. monocytogenes strains were not abundant since mainly members of the genera Citrobacter and Lactococcus dominated the bacterial biofilm community. Overall, added L. monocytogenes strains led to a highly competitive interaction with the raw milk community and triggered alterations in biofilm formation. Copyright © 2012 Elsevier B.V. All rights reserved.

Exploiting the aerobic endospore-forming bacterial diversity in saline and hypersaline environments for biosurfactant production.

Science.gov (United States)

de Almeida Couto, Camila Rattes; Alvarez, Vanessa Marques; Marques, Joana Montezano; de Azevedo Jurelevicius, Diogo; Seldin, Lucy

2015-10-28

Biosurfactants are surface-active biomolecules with great applicability in the food, pharmaceutical and oil industries. Endospore-forming bacteria, which survive for long periods in harsh environments, are described as biosurfactant producers. Although the ubiquity of endospore-forming bacteria in saline and hypersaline environments is well known, studies on the diversity of the endospore-forming and biosurfactant-producing bacterial genera/species in these habitats are underrepresented. In this study, the structure of endospore-forming bacterial communities in sediment/mud samples from Vermelha Lagoon, Massambaba, Dois Rios and Abraão Beaches (saline environments), as well as the Praia Seca salterns (hypersaline environments) was determined via denaturing gradient gel electrophoresis. Bacterial strains were isolated from these environmental samples and further identified using 16S rRNA gene sequencing. Strains presenting emulsification values higher than 30 % were grouped via BOX-PCR, and the culture supernatants of representative strains were subjected to high temperatures and to the presence of up to 20 % NaCl to test their emulsifying activities in these extreme conditions. Mass spectrometry analysis was used to demonstrate the presence of surfactin. A diverse endospore-forming bacterial community was observed in all environments. The 110 bacterial strains isolated from these environmental samples were molecularly identified as belonging to the genera Bacillus, Thalassobacillus, Halobacillus, Paenibacillus, Fictibacillus and Paenisporosarcina. Fifty-two strains showed emulsification values of at least 30%, and they were grouped into 18 BOX groups. The stability of the emulsification values varied when the culture supernatants of representative strains were subjected to high temperatures and to the presence of up to 20% NaCl. The presence of surfactin was demonstrated in one of the most promising strains. The environments studied can harbor endospore

Evaluation of environmental bacterial communities as a factor affecting the growth of duckweed Lemna minor.

Science.gov (United States)

Ishizawa, Hidehiro; Kuroda, Masashi; Morikawa, Masaaki; Ike, Michihiko

2017-01-01

Duckweed (family Lemnaceae ) has recently been recognized as an ideal biomass feedstock for biofuel production due to its rapid growth and high starch content, which inspired interest in improving their productivity. Since microbes that co-exist with plants are known to have significant effects on their growth according to the previous studies for terrestrial plants, this study has attempted to understand the plant-microbial interactions of a duckweed, Lemna minor , focusing on the growth promotion/inhibition effects so as to assess the possibility of accelerated duckweed production by modifying co-existing bacterial community. Co-cultivation of aseptic L. minor and bacterial communities collected from various aquatic environments resulted in changes in duckweed growth ranging from -24 to +14% compared to aseptic control. A number of bacterial strains were isolated from both growth-promoting and growth-inhibitory communities, and examined for their co-existing effects on duckweed growth. Irrespective of the source, each strain showed promotive, inhibitory, or neutral effects when individually co-cultured with L. minor . To further analyze the interactions among these bacterial strains in a community, binary combinations of promotive and inhibitory strains were co-cultured with aseptic L. minor , resulting in that combinations of promotive-promotive or inhibitory-inhibitory strains generally showed effects similar to those of individual strains. However, combinations of promotive-inhibitory strains tended to show inhibitory effects while only Aquitalea magnusonii H3 exerted its plant growth-promoting effect in all combinations tested. Significant change in biomass production was observed when duckweed was co-cultivated with environmental bacterial communities. Promotive, neutral, and inhibitory bacteria in the community would synergistically determine the effects. The results indicate the possibility of improving duckweed biomass production via regulation of co

Role of the Genes of Type VI Secretion System in Virulence of Rice Bacterial Brown Stripe Pathogen Acidovorax avenae subsp. avenae Strain RS-2

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Md. Mahidul Islam Masum

2017-09-01

Full Text Available The Type VI secretion system (T6SS is a class of macromolecular machine that is required for the virulence of gram-negative bacteria. However, it is still not clear what the role of T6SS in the virulence of rice bacterial brown stripe pathogen Acidovorax avenae subsp. avenae (Aaa is. The aim of the current study was to investigate the contribution of T6SS in Aaa strain RS2 virulence using insertional deletion mutation and complementation approaches. This strain produced weak virulence but contains a complete T6SS gene cluster based on a genome-wide analysis. Here we compared the virulence-related phenotypes between the wild-type (RS-2 and 25 T6SS mutants, which were constructed using homologous recombination methods. The mutation of 15 T6SS genes significantly reduced bacterial virulence and the secretion of Hcp protein. Additionally, the complemented 7 mutations ΔpppA, ΔclpB, Δhcp, ΔdotU, ΔicmF, ΔimpJ, and ΔimpM caused similar virulence characteristics as RS-2. Moreover, the mutant ΔpppA, ΔclpB, ΔicmF, ΔimpJ and ΔimpM genes caused by a 38.3~56.4% reduction in biofilm formation while the mutants ΔpppA, ΔclpB, ΔicmF and Δhcp resulted in a 37.5~44.6% reduction in motility. All together, these results demonstrate that T6SS play vital roles in the virulence of strain RS-2, which may be partially attributed to the reductions in Hcp secretion, biofilm formation and motility. However, differences in virulence between strain RS-1 and RS-2 suggest that other factors may also be involved in the virulence of Aaa.

Role of the Genes of Type VI Secretion System in Virulence of Rice Bacterial Brown Stripe Pathogen Acidovorax avenae subsp. avenae Strain RS-2.

Science.gov (United States)

Masum, Md Mahidul Islam; Yang, Yingzi; Li, Bin; Olaitan, Ogunyemi Solabomi; Chen, Jie; Zhang, Yang; Fang, Yushi; Qiu, Wen; Wang, Yanli; Sun, Guochang

2017-09-21

The Type VI secretion system (T6SS) is a class of macromolecular machine that is required for the virulence of gram-negative bacteria. However, it is still not clear what the role of T6SS in the virulence of rice bacterial brown stripe pathogen Acidovorax avenae subsp. avenae (Aaa) is. The aim of the current study was to investigate the contribution of T6SS in Aaa strain RS2 virulence using insertional deletion mutation and complementation approaches. This strain produced weak virulence but contains a complete T6SS gene cluster based on a genome-wide analysis. Here we compared the virulence-related phenotypes between the wild-type (RS-2) and 25 T6SS mutants, which were constructed using homologous recombination methods. The mutation of 15 T6SS genes significantly reduced bacterial virulence and the secretion of Hcp protein. Additionally, the complemented 7 mutations Δ pppA , Δ clpB , Δ hcp , Δ dotU , Δ icmF , Δ impJ , and Δ impM caused similar virulence characteristics as RS-2. Moreover, the mutant Δ pppA , Δ clpB , Δ icmF , Δ impJ and Δ impM genes caused by a 38.3~56.4% reduction in biofilm formation while the mutants Δ pppA , Δ clpB , Δ icmF and Δ hcp resulted in a 37.5~44.6% reduction in motility. All together, these results demonstrate that T6SS play vital roles in the virulence of strain RS-2, which may be partially attributed to the reductions in Hcp secretion, biofilm formation and motility. However, differences in virulence between strain RS-1 and RS-2 suggest that other factors may also be involved in the virulence of Aaa.

Dielectrophoretic assay of bacterial resistance to antibiotics

International Nuclear Information System (INIS)

Johari, Juliana; Huebner, Yvonne; Hull, Judith C; Dale, Jeremy W; Hughes, Michael P

2003-01-01

The dielectrophoretic collection spectra of antibiotic-sensitive and antibiotic-resistant strains of Staphylococcus epidermidis have been determined. These indicate that in the absence of antibiotic treatment there is a strong similarity between the dielectric properties of sensitive and resistant strains, and that there is a significant difference between the sensitive strains before and after treatment with the antibiotic streptomycin after 24 h exposure. This method offers possibilities for the assessment of bacterial resistance to antibiotics. (note)

Bisphosphonates enhance bacterial adhesion and biofilm formation on bone hydroxyapatite.

Science.gov (United States)

Kos, Marcin; Junka, Adam; Smutnicka, Danuta; Szymczyk, Patrycja; Gluza, Karolina; Bartoszewicz, Marzenna

2015-07-01

Because of the suspicion that bisphosphonates enhance bacterial colonization, this study evaluated adhesion and biofilm formation by Streptococcus mutans 25175, Staphylococcus aureus 6538, and Pseudomonas aeruginosa 14454 reference strains on hydroxyapatite coated with clodronate, pamidronate, or zoledronate. Bacterial strains were cultured on bisphosphonate-coated and noncoated hydroxyapatite discs. After incubation, nonadhered bacteria were removed by centrifugation. Biofilm formation was confirmed by scanning electron microscopy. Bacterial colonization was estimated using quantitative cultures compared by means with Kruskal-Wallis and post-hoc Student-Newman-Keuls tests. Modeling of the interactions between bisphosphonates and hydroxyapatite was performed using the Density Functional Theory method. Bacterial colonization of the hydroxyapatite discs was significantly higher for all tested strains in the presence of bisphosphonates vs. Adherence in the presence of pamidronate was higher than with other bisphosphonates. Density Functional Theory analysis showed that the protonated amine group of pamidronate, which are not present in clodronate or zoledronate, forms two additional hydrogen bonds with hydroxyapatite. Moreover, the reactive cationic amino group of pamidronate may attract bacteria by direct electrostatic interaction. Increased bacterial adhesion and biofilm formation can promote osteomyelitis, cause failure of dental implants or bisphosphonate-coated joint prostheses, and complicate bone surgery in patients on bisphosphonates. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Clostridial Strain-Specific Characteristics Associated with Necrotizing Enterocolitis.

Science.gov (United States)

Schönherr-Hellec, Sophia; Klein, Geraldine L; Delannoy, Johanne; Ferraris, Laurent; Rozé, Jean Christophe; Butel, Marie José; Aires, Julio

2018-04-01

We aimed at identifying potential bacterial factors linking clostridia with necrotizing enterocolitis (NEC). We compared the phenotypic traits, stress responses, cellular cytotoxicity, and inflammatory capabilities of the largest collection of Clostridium butyricum and Clostridium neonatale strains isolated from fecal samples of NEC preterm neonates (PN) and control PNs. When strain characteristics were used as explanatory variables, a statistical discriminant analysis allowed the separation of NEC and control strains into separate groups. Strains isolated from NEC PN were characterized by a higher viability at 30°C ( P = 0.03) and higher aerotolerance ( P = 0.01), suggesting that NEC strains may have a competitive and/or survival advantage in the environmental gastrointestinal tract conditions of NEC PN. Heat-treated NEC bacteria induced higher production of interleukin-8 in Caco-2 cells ( P = 0.03), suggesting proinflammatory activity. In vitro , bacteria, bacterial components, and fecal filtrates showed variable cytotoxic effects affecting the cellular network and/or cell viability, without specific association with NEC or control samples. Altogether, our data support the existence of a specific clostridial strain signature associated with NEC. IMPORTANCE Clostridia are part of the commensal microbiota in preterm neonates (PN). However, microbiota analyses by culture and metagenomics have linked necrotizing enterocolitis (NEC) and intestinal colonization with clostridial species. Nevertheless, little is known about the specific characteristics that may be shared by clostridia associated with NEC compared to commensal clostridia. Therefore, our goal was to identify specific bacterial factors linking clostridial strains with NEC. We report the existence of a specific bacterial signature associated with NEC and propose that activation of the innate immune response may be a unifying causative mechanism for the development of NEC independent of a specific pathogenic

Methyl bromide fumigation and delayed mortality: safe trade of live pests?

Science.gov (United States)

Phillips, C B; Iline, I I; Novoselov, M; McNeill, M R; Richards, N K; van Koten, C; Stephenson, B P

Live organisms intercepted from treated commodities during phytosanitary inspections usually arouse suspicions of treatment failure, sub-standard treatment application, or post-treatment infestation. The additional possibility that some treatments could kill slowly, meaning commodities might be inspected before pests have succumbed, is seldom considered for treatments other than irradiation. We used a novel biochemical viability assay to measure delays between methyl bromide fumigation and mortality of dipteran eggs, and evaluated the correspondence between egg viability and egg morphological features. Our experimental conditions simulated shipping of rock melons from Australia to New Zealand by sea and air. No eggs survived fumigation, but they took 3-20 days to die, whereas phytosanitary inspections of rock melons occur within 2-7 days. Delays were not influenced by methyl bromide concentration, but were significantly lengthened by cooler storage temperatures. Methyl bromide's preservative effects delayed degradation of egg morphology, so the biochemical assay detected mortality long before morphological signs of egg death appeared. The results show that commodities subjected to effective methyl bromide treatments are at risk of being inspected before all pests have either died, or started to exhibit morphological signs of death. This could cause commodities to be unnecessarily rejected by quarantine authorities. Better methods than inspection for live pests are needed to assist authorities to gain assurance that treated commodities have been effectively disinfested. These could be developed by exploiting biochemical responses of pests and commodities to treatments.

Bromide as a tracer for studying water movement and nitrate displacement in soils: comparison with stable isotope tracers; Bromid als Tracer zur Untersuchung der Wasserbewegung und der Nitratverlagerung in Boeden: Vergleich mit stabilisotopen Tracern

Energy Technology Data Exchange (ETDEWEB)

Russow, R.; Knappe, S. [UFZ - Umweltforschungszentrum Leipzig-Halle GmbH, Bad Lauchstaedt (Germany). Sektion Bodenforschung

1999-02-01

Tracers are an ideal means of studying water movement and associated nitrate displacement. Often bromide is preferred as a tracer because it is considered a representative tracer for water and because, being a conservative tracer (i.e. not involved in chemical and biological soil processes), it can be used for studying anion transport in soils. Moreover, it is less expensive and easier to measure than the stable isotopes deuterium and {sup 15}N. Its great advantage over radioactive tracers (e.g. tritium), which outweighs their extreme sensitivity and ease of measurement and which it has in common with stable isotopes, is that it does not require radiation protection measures. However, there are also constraints on the use of bromide as a tracer in soil/water/plant systems. Our own studies on different soils using D{sub 2}O, bromide and [{sup 15}N]-nitrate in lysimeters suggest that the above assumptions on bromide tracers need not always be valid under conditions as they prevail in biologically active soils. As the present paper shows, these studies permit a good assessment of the possibilities and limits to these tracers. [Deutsch] Fuer die Untersuchung der Wasserbewegung sowie der daran gekoppelten Nitrat-Verlagerung ist der Einsatz von Tracern das Mittel der Wahl. Dabei wird Bromid als Tracer haeufig bevorzugt, da es allgemein als ein repraesentativer Tracer fuer Wasser und als konservativer Tracer (nicht involviert in chemische und biologische Bodenprozesse) zur Untersuchung des Anionentransportes in Boeden angesehen wird und es gegenueber den stabilen Isotopen Deuterium und {sup 15}N billiger und einfacher zu bestimmen ist. Gegenueber den radioaktiven Tracern (z.B. Tritium), die zwar sehr empfindlich und einfach messbar sind, besteht der grosse Vorteil, dass, wie bei den stabilen Isotopen, keine Strahlenschutzmassnahmen ergriffen werden muessen. Es gibt jedoch auch einschraenkende Hinweise fuer die Verwendung von Bromid als Tracer im System Boden

Iron bromide vapor laser

Science.gov (United States)

Sukhanov, V. B.; Shiyanov, D. V.; Trigub, M. V.; Dimaki, V. A.; Evtushenko, G. S.

2016-03-01

We have studied the characteristics of a pulsed gas-discharge laser on iron bromide vapor generating radiation with a wavelength of 452.9 nm at a pulse repetition frequency (PRF) of 5-30 kHz. The maximum output power amounted to 10 mW at a PRF within 5-15 kHz for a voltage of 20-25 kV applied to electrodes of the discharge tube. Addition of HBr to the medium produced leveling of the radial profile of emission. Initial weak lasing at a wavelength of 868.9 nm was observed for the first time, which ceased with buildup of the main 452.9-nm line.

Ethidium bromide resistance of L929 cells is accompanied by regular changes in karotype structure

International Nuclear Information System (INIS)

Grinchuk, T.M.; Novikova, I.Yu.; Sorokina, E.A.; Sal'nikov, K.V.

1988-01-01

Using the method of differential staining of chromosomes for G-bands a comparative karyological analysis of line L 929 mouse cells has been conducted, after the L 929 cells had been sequentially selected for resistance to ethidium bromide at concentrations of 1, 10, 25, and 50 μg/ml and had retained these levels of resistance for a number of cell generations. It was found that the resistant variants exhibited certain karyotypic changes. Only thirteen of the thirty six marker chromosomes typical of the original ethidium bromide-sensitive cells were preserved. Sixteen of the markers were specific for the resistant variants. The changes detected arose at the initial selection stage and were preserved unaltered as the concentration of the toxin was raised. The detection of similar karyotypic changes in cells of clone L 929 of independent origin selected for resistance of 3 μg/ml of ethidium bromide and also in cells of the clone selected for resistance to 25 μg/ml of ethidium bromide and studied previously by the present authors suggests that these changes are universal for L 929 cells resistant to ethidium bromide

Evaluation of Anti-adherent Activity of Excretions of Irradiated Lucilia sericata Maggot and Certain Essential Oils against Some Pathogenic Bacterial Strains

International Nuclear Information System (INIS)

Eltablawy, S.Y.; Amin, M.M.

2011-01-01

Essential Oils are widely used for their medicinal properties. They block adhesion and colonization of pathogenic microbes to epithelial cells which associated with bacterial resistance to antibiotics. So, this study investigates the effect of Lu cilia sacarato (flesh fly-an ectoparasitic) excretions of non-irradiated and irradiated maggot and some essential oils on biofilm formation by tube method, antimicrobial susceptibility by agar disc diffusion method as well as on their anti-adherent activity by spectrophotometric method. The results showed that excretions and secretions (E/S) of non-irradiated and irradiated maggots (at 20 Gy), as well as (clove and cinnamon oils) did not have antibacterial activity against the tested bacterial strains Pseudomonas aeruginosa (P. aeruginosa), Staphylococcus aureus (St. aureus) and Staphylococcus epidermidis (St. epidermidis) except marjoram oil which has low antimicrobial activity against all the tested strains. The results also showed that the most potent oil was clove which decrease biofilm of P. aeruginosa by 83%, followed by marjoram (69%), then E/S of non-irradiated maggots (66%). Whiles, biofilm was less affected by cinnamon oil and E/S of irradiated maggots by 50 % and 36%, respectively. In addition, clove oil and E/S of non-irradiated maggots affect the pre-adhered biofilm of P. aeruginosa by 57 and 45 %, respectively. Conclusion: Clove oil flowed by marjoram had anti-adherent effect on P. aeruginosa. Greater inhibition of adhesion was observed by excretions of non-irradiated lucilia sericata.

Organic metabolites produced by Vibrio parahaemolyticus strain ...

African Journals Online (AJOL)

Identification and action of several antibacterial metabolites produced by a fish pathogen Vibrio parahaemolyticus strain An3 from marine ecosystem of Goa has been demonstrated. Antibacterial activity of the crude cell extract of the test bacterium has been evaluated against indicator pathogenic bacterial strains such as ...

The longitudinal effect of a multi-strain probiotic on the intestinal bacterial microbiota of neonatal foals

DEFF Research Database (Denmark)

Schoster, Angelika; Guardabassi, Luca; Staempfli, H. R.

2016-01-01

REASONS FOR PERFORMING THE STUDY: The microbiota plays a key role in health and disease. Probiotics are a potential way to therapeutically modify the intestinal microbiota and prevent disease. OBJECTIVES: The aim of this study was to investigate the effects of probiotics on the bacterial microbiota...... of foals during and after administration. STUDY DESIGN: Randomised placebo controlled field trial. METHODS: Thirty-eight healthy neonatal foals enrolled in a prior study were selected. The foals had received a multi-strain probiotic (four Lactobacillus spp 3-4x10(3) cfu/g each, Bifidobacterium animalis spp...... or class level between treatment groups at any age (all p>0.08) but some significant changes in relative abundance of families. Probiotic administration did not result in an increased relative abundance of lactobacilli or bifidobacteria at any age (Lactobacillus: p = 0.95, p = 0.1 and p = 0...

Preliminary data on antibacterial activity of Echinacea purpurea-associated bacterial communities against Burkholderia cepacia complex strains, opportunistic pathogens of Cystic Fibrosis patients.

Science.gov (United States)

Chiellini, Carolina; Maida, Isabel; Maggini, Valentina; Bosi, Emanuele; Mocali, Stefano; Emiliani, Giovanni; Perrin, Elena; Firenzuoli, Fabio; Mengoni, Alessio; Fani, Renato

2017-03-01

Burkholderia cepacia complex bacteria (Bcc) represent a serious threat for immune-compromised patient affected by Cystic Fibrosis (CF) since they are resistant to many substances and to most antibiotics. For this reason, the research of new natural compounds able to inhibit the growth of Bcc strains has raised new interest during the last years. A source of such natural compounds is represented by medicinal plants and, in particular, by bacterial communities associated with these plants able to produce molecules with antimicrobial activity. In this work, a panel of 151 (endophytic) bacteria isolated from three different compartments (rhizospheric soil, roots, and stem/leaves) of the medicinal plant Echinacea purpurea were tested (using the cross-streak method) for their ability to inhibit the growth of 10 Bcc strains. Data obtained revealed that bacteria isolated from the roots of E. purpurea are the most active in the inhibition of Bcc strains, followed by bacteria isolated from the rhizospheric soil, and endophytes from stem/leaf compartment. At the same time, Bcc strains of environmental origin showed a higher resistance toward inhibition than the Bcc strains with clinical (i.e. CF patients) origin. Differences in the inhibition activity of E. purpurea-associated bacteria are mainly linked to the environment -the plant compartment- rather than to their taxonomical position. Copyright © 2016 Elsevier GmbH. All rights reserved.

Biodegradation of hard keratins by two bacillus strains.

Science.gov (United States)

Laba, Wojciech; Rodziewicz, Anna

2014-02-01

Extensive quantities of keratinic by-products are disposed annually by animal-processing industry, causing a mounting ecological problem due to extreme resilience of these materials to enzymatic breakdown. There is a growing trend to apply cheap and environment-friendly methods to recycle keratinic wastes. Soil bacteria of profound keratinolytic potential, especially spore-forming rods from the genus Bacillus, play a significant role in keratinase-mediated biodegradation of keratins, therefore could be effective in hastening their biodegradation. Keratin hydrolysis in microbial cultures is one of the most promising techniques not only to utilize this protein but also to obtain valuable by products. The study was undertaken to investigate the biodegradation process of various keratinic materials by two Bacillus strains. Two keratinolytic strains, Bacillus cereus and B. polymyxa, were subject to cultures in the presence of several keratinic appendages, like chicken feathers, barbs and rachea of ostrich feathers, pig bristle, lamb wool, human hair and stratum corneum of epidermis, as main nutrient sources. Bacterial ability to decompose these waste materials was evaluated, at the background of keratinase and protease biosynthesis, in brief four-day cultures. Keratinolytic activity was measured on soluble keratin preparation and proteases were assayed on casein. Additionally, amounts of liberated proteins, amino acids and thiols were evaluated. Residual keratin weight was tested afterwards. Both tested strains proved to be more adapted for fast biodegradation of feather β-keratins than hair-type α-keratins. B. cereus revealed its significant proteolytic potential, especially on whole chicken feathers (230 PU) and stratum corneum (180 PU), but also on separated barbs and rachea, which appeared to be moderate protease inducers. Keratinolytic activity of B. cereus was comparable on most substrates and maximum level obtained was 11 KU. B. polymyxa was found to be a

Polysaccharide utilization loci and nutritional specialization in a dominant group of butyrate-producing human colonic Firmicutes.

Science.gov (United States)

Sheridan, Paul O; Martin, Jennifer C; Lawley, Trevor D; Browne, Hilary P; Harris, Hugh M B; Bernalier-Donadille, Annick; Duncan, Sylvia H; O'Toole, Paul W; Scott, Karen P; Flint, Harry J

2016-02-01

Firmicutes and Bacteroidetes are the predominant bacterial phyla colonizing the healthy human large intestine. Whilst both ferment dietary fibre, genes responsible for this important activity have been analysed only in the Bacteroidetes , with very little known about the Firmicutes . This work investigates the carbohydrate-active enzymes (CAZymes) in a group of Firmicutes , Roseburia spp. and Eubacterium rectale , which play an important role in producing butyrate from dietary carbohydrates and in health maintenance. Genome sequences of 11 strains representing E. rectale and four Roseburia spp. were analysed for carbohydrate-active genes. Following assembly into a pan-genome, core, variable and unique genes were identified. The 1840 CAZyme genes identified in the pan-genome were assigned to 538 orthologous groups, of which only 26 were present in all strains, indicating considerable inter-strain variability. This analysis was used to categorize the 11 strains into four carbohydrate utilization ecotypes (CUEs), which were shown to correspond to utilization of different carbohydrates for growth. Many glycoside hydrolase genes were found linked to genes encoding oligosaccharide transporters and regulatory elements in the genomes of Roseburia spp. and E. rectale , forming distinct polysaccharide utilization loci (PULs). Whilst PULs are also a common feature in Bacteroidetes , key differences were noted in these Firmicutes , including the absence of close homologues of Bacteroides polysaccharide utilization genes, hence we refer to Gram-positive PULs (gpPULs). Most CAZyme genes in the Roseburia / E. rectale group are organized into gpPULs. Variation in gpPULs can explain the high degree of nutritional specialization at the species level within this group.

Forces involved in bacterial adhesion to hydrophilic and hydrophobic surfaces

NARCIS (Netherlands)

Boks, N.P.; Norde, W.; Meil, H.C.; Busscher, H.J.

2008-01-01

Using a parallel-plate flow chamber, the hydrodynamic shear forces to prevent bacterial adhesion (F-prev) and to detach adhering bacteria (F-det) were evaluated for hydrophilic glass, hydrophobic, dimethyldichlorosilane (DDS)-coated glass and six different bacterial strains, in order to test the

Transport of EDTA into cells of the EDTA-degrading bacterial strain DSM 9103.

Science.gov (United States)

Witschel, M; Egli, T; Zehnder, A J; Wehrli, E; Spycher, M

1999-04-01

In the bacterial strain DSM 9103, which is able to grow with the complexing agent EDTA as the sole source of carbon, nitrogen and energy, the transport of EDTA into whole cells was investigated. EDTA uptake was found to be dependent on speciation: free EDTA and metal-EDTA complexes with low stability constants were readily taken up, whereas those with stability constants higher than 1016 were not transported. In EDTA-grown cells, initial transport rates of CaEDTA showed substrate-saturation kinetics with a high apparent affinity for CaEDTA (affinity constant Kt= 0.39 microM). Several uncouplers had an inhibitory effect on CaEDTA transport. CaEDTA uptake was also significantly reduced in the presence of an inhibitor of ATPase and the ionophore nigericin, which dissipates the proton gradient. Valinomycin, however, which affects the electrical potential, had little effect on uptake, indicating that EDTA transport is probably driven by the proton gradient. Of various structurally related compounds tested only Ca2+-complexed diethylenetriaminepentaacetate (CaDTPA) competitively inhibited CaEDTA transport. Uptake in fumarate-grown cells was low compared to that measured in EDTA-grown bacteria. These results strongly suggest that the first step in EDTA degradation by strain DSM 9103 consists of transport by an inducible energy-dependent carrier. Uptake experiments with 45Ca2+ in the presence and absence of EDTA indicated that Ca2+ is transported together with EDTA into the cells. In addition, these transport studies and electron-dispersive X-ray analysis of electron-dense intracellular bodies present in EDTA-grown cells suggest that two mechanisms acting simultaneously allow the cells to cope with the large amounts of metal ions taken up together with EDTA. In one mechanism the metal ions are excreted, in the other they are inactivated intracellularly in polyphosphate granules.

High prevalence of biofilm synergy among bacterial soil isolates in cocultures indicates bacterial interspecific cooperation

DEFF Research Database (Denmark)

Ren, Dawei; Madsen, Jonas Stenløkke; Sørensen, Søren Johannes

2015-01-01

of single-species biofilms, indicating that all the individual strains benefit from inclusion in the multispecies community. Our results show a high prevalence of synergy in biofilm formation in multispecies consortia isolated from a natural bacterial habitat and suggest that interspecific cooperation...

Haloalkane-utilizing Rhodococcus strains isolated from geographically distinct locations possess a highly conserved gene cluster encoding haloalkane catabolism

NARCIS (Netherlands)

Poelarends, GJ; Bosma, T; Kulakov, LA; Larkin, MJ; Marchesi, [No Value; Weightman, AJ; Janssen, DB; Kulakov, Leonid A.; Larkin, Michael J.; Marchesi, Julian R.; Weightman, Andrew J.

The sequences of the 16S rRNA and haloalkane dehalogenase (dhaA) genes of five gram-positive haloalkane-utilizing bacteria isolated from contaminated sites in Europe, Japan, and the United States and of the archetypal haloalkane-degrading bacterium Rhodococcus sp. strain NCIMB13064 were compared.

Prostate cancer and toxicity from critical use exemptions of methyl bromide: Environmental protection helps protect against human health risks

Directory of Open Access Journals (Sweden)

Budnik Lygia T

2012-01-01

Full Text Available Abstract Background Although ozone-depleting methyl bromide was destined for phase-out by 2005, it is still widely applied as a consequence of various critical-use-exemptions and mandatory international regulations aiming to restrict the spread of pests and alien species (e.g. in globalized transport and storage. The withdrawal of methyl bromide because of its environmental risk could fortuitously help in the containment of its human toxicity. Methods We performed a systematic review of the literature, including in vitro toxicological and epidemiological studies of occupational and community exposure to the halogenated hydrocarbon pesticide methyl bromide. We focused on toxic (especially chronic or carcinogenic effects from the use of methyl bromide, on biomonitoring data and reference values. Eligible epidemiological studies were subjected to meta-analysis. Results Out of the 542 peer reviewed publications between 1990-2011, we found only 91 referring to toxicity of methyl bromide and 29 using the term "carcinogenic", "neoplastic" or "mutagenic". Several studies provide new additional data pertaining to the mechanistic aspects of methyl bromide toxicity. Few studies have performed a detailed exposure assessment including biomonitoring. Three evaluated epidemiological studies assessed a possible association between cancer and methyl bromide. Overall, exposure to methyl bromide is associated with an increased risk of prostate cancer OR, 1.21; 95% CI (0,98-1.49, P = 0.076. Two epidemiological studies have analyzed environmental, non-occupational exposure to methyl bromide providing evidence for its health risk to the general public. None of the epidemiological studies addressed its use as a fumigant in freight containers, although recent field and case reports do refer to its toxic effects associated with its use in shipping and storage. Conclusions Both the epidemiological evidence and toxicological data suggest a possible link between methyl

Influence of bacterial interactions on pneumococcal colonization of the nasopharynx.

Science.gov (United States)

Shak, Joshua R; Vidal, Jorge E; Klugman, Keith P

2013-03-01

Streptococcus pneumoniae (the pneumococcus) is a common commensal inhabitant of the nasopharynx and a frequent etiologic agent in serious diseases such as pneumonia, otitis media, bacteremia, and meningitis. Multiple pneumococcal strains can colonize the nasopharynx, which is also home to many other bacterial species. Intraspecies and interspecies interactions influence pneumococcal carriage in important ways. Co-colonization by two or more pneumococcal strains has implications for vaccine serotype replacement, carriage detection, and pneumonia diagnostics. Interactions between the pneumococcus and other bacterial species alter carriage prevalence, modulate virulence, and affect biofilm formation. By examining these interactions, this review highlights how the bacterial ecosystem of the nasopharynx changes the nature and course of pneumococcal carriage. Copyright © 2012 Elsevier Ltd. All rights reserved.

Identification of an Endophytic Antifungal Bacterial Strain Isolated from the Rubber Tree and Its Application in the Biological Control of Banana Fusarium Wilt.

Directory of Open Access Journals (Sweden)

Deguan Tan

Full Text Available Banana Fusarium wilt (also known as Panama disease is one of the most disastrous plant diseases. Effective control methods are still under exploring. The endophytic bacterial strain ITBB B5-1 was isolated from the rubber tree, and identified as Serratia marcescens by morphological, biochemical, and phylogenetic analyses. This strain exhibited a high potential for biological control against the banana Fusarium disease. Visual agar plate assay showed that ITBB B5-1 restricted the mycelial growth of the pathogenic fungus Fusarium oxysporum f. sp. cubense race 4 (FOC4. Microscopic observation revealed that the cell wall of the FOC4 mycelium close to the co-cultured bacterium was partially decomposed, and the conidial formation was prohibited. The inhibition ratio of the culture fluid of ITBB B5-1 against the pathogenic fungus was 95.4% as estimated by tip culture assay. Chitinase and glucanase activity was detected in the culture fluid, and the highest activity was obtained at Day 2 and Day 3 of incubation for chitinase and glucanase, respectively. The filtrated cell-free culture fluid degraded the cell wall of FOC4 mycelium. These results indicated that chitinase and glucanase were involved in the antifungal mechanism of ITBB B5-1. The potted banana plants that were inoculated with ITBB B5-1 before infection with FOC4 showed 78.7% reduction in the disease severity index in the green house experiments. In the field trials, ITBB B5-1 showed a control effect of approximately 70.0% against the disease. Therefore, the endophytic bacterial strain ITBB B5-1 could be applied in the biological control of banana Fusarium wilt.

DNA-mediated bacterial aggregation is dictated by acid-base interactions

NARCIS (Netherlands)

Das, Theerthankar; Krom, Bastiaan P.; van der Mei, Henny C.; Busscher, Henk J.; Sharma, Prashant K.

2011-01-01

Extracellular DNA (eDNA) plays a significant role in bacterial biofilm formation and aggregation. Here, for the first time, we present a physico-chemical analysis of the DNA-mediated aggregation for three bacterial strains (Streptococcus mutans LT11, Pseudomonas aeruginosa PAO1 and Staphylococcus

Bacterial growth kinetics

International Nuclear Information System (INIS)

Boonkitticharoen, V.; Ehrhardt, J.C.; Kirchner, P.T.

1989-01-01

Quantitative measurement of bacterial growth may be made using a radioassay technique. This method measures, by scintillation counting, the 14 CO 2 derived from the bacterial metabolism of a 14 C-labeled substrate. Mathematical growth models may serve as reliable tools for estimation of the generation rate constant (or slope of the growth curve) and provide a basis for evaluating assay performance. Two models, i.e., exponential and logistic, are proposed. Both models yielded an accurate fit to the data from radioactive measurement of bacterial growth. The exponential model yielded high precision values of the generation rate constant, with an average relative standard deviation of 1.2%. Under most conditions the assay demonstrated no changes in the slopes of growth curves when the number of bacteria per inoculation was changed. However, the radiometric assay by scintillation method had a growth-inhibiting effect on a few strains of bacteria. The source of this problem was thought to be hypersensitivity to trace amounts of toluene remaining on the detector

Cost versus utility of aclidinium bromide 400 µg plus formoterol fumarate dihydrate 12 µg compared to aclidinium bromide 400 µg alone in the management of moderate-to-severe COPD

Science.gov (United States)

Ramos, Mafalda; Haughney, John; Henry, Nathaniel; Lindner, Leandro; Lamotte, Mark

2016-01-01

Purpose Aclidinium–formoterol 400/12 µg is a long-acting muscarinic antagonist (LAMA) and a long-acting β2-agonist in a fixed-dose combination used in the management of patients with COPD. This study aimed to assess the cost-effectiveness of aclidinium–formoterol 400/12 µg against the long-acting muscarinic antagonist aclidinium bromide 400 µg. Materials and methods A five-health-state Markov transition model with monthly cycles was developed using MS Excel to simulate patients with moderate-to-severe COPD and their initial lung-function improvement following treatment with aclidinium–formoterol 400/12 µg or aclidinium 400 µg. Health states were based on severity levels defined by Global Initiative for Chronic Obstructive Lung Disease 2010 criteria. The analysis was a head-to-head comparison without step-up therapy, from the NHS Scotland perspective, over a 5-year time horizon. Clinical data on initial lung-function improvement were provided by a pooled analysis of the ACLIFORM and AUGMENT trials. Management, event costs, and utilities were health state-specific. Costs and effects were discounted at an annual rate of 3.5%. The outcome of the analysis was expressed as cost (UK£) per quality-adjusted life-year (QALY) gained. The analysis included one way and probabilistic sensitivity analyses to investigate the impact of parameter uncertainty on model outputs. Results Aclidinium–formoterol 400/12 µg provided marginally higher costs (£41) and more QALYs (0.014), resulting in an incremental cost-effectiveness ratio of £2,976/QALY. Sensitivity analyses indicated that results were robust to key parameter variations, and the main drivers were: mean baseline forced expiratory volume in 1 second (FEV1), risk of exacerbation, FEV1 improvement from aclidinium–formoterol 400/12 µg, and lung-function decline. The probability of aclidinium–formoterol 400/12 µg being cost-effective (using a willingness-to-pay threshold of £20,000/QALY) versus aclidinium

Iodate and iodo-trihalomethane formation during chlorination of iodide-containing waters: role of bromide.

Science.gov (United States)

Criquet, Justine; Allard, Sebastien; Salhi, Elisabeth; Joll, Cynthia A; Heitz, Anna; von Gunten, Urs

2012-07-03

The kinetics of iodate formation is a critical factor in mitigation of the formation of potentially toxic and off flavor causing iodoorganic compounds during chlorination. This study demonstrates that the formation of bromine through the oxidation of bromide by chlorine significantly enhances the oxidation of iodide to iodate in a bromide-catalyzed process. The pH-dependent kinetics revealed species specific rate constants of k(HOBr + IO(-)) = 1.9 × 10(6) M(-1) s(-1), k(BrO(-) + IO(-)) = 1.8 × 10(3) M(-1) s(-1), and k(HOBr + HOI) < 1 M(-1) s(-1). The kinetics and the yield of iodate formation in natural waters depend mainly on the naturally occurring bromide and the type and concentration of dissolved organic matter (DOM). The process of free chlorine exposure followed by ammonia addition revealed that the formation of iodo-trihalomethanes (I-THMs), especially iodoform, was greatly reduced by an increase of free chlorine exposure and an increase of the Br(-)/I(-) ratio. In water from the Great Southern River (with a bromide concentration of 200 μg/L), the relative I-incorporation in I-THMs decreased from 18 to 2% when the free chlorine contact time was increased from 2 to 20 min (chlorine dose of 1 mg Cl(2)/L). This observation is inversely correlated with the conversion of iodide to iodate, which increased from 10 to nearly 90%. Increasing bromide concentration also increased the conversion of iodide to iodate: from 45 to nearly 90% with a bromide concentration of 40 and 200 μg/L, respectively, and a prechlorination time of 20 min, while the I-incorporation in I-THMs decreased from 10 to 2%.

Agricultural management legacy affects microbial energetics, resource utilization and active bacterial community membership during 13C-glucose consumption

Science.gov (United States)

Helgason, B. L.; Levy-Booth, D.; Arcand, M. M.

2017-12-01

Over the long-term, differences in soil management can result in fundamental changes in biogeochemical cycling. The Alternative Cropping Systems (ACS) Study at Scott, SK, Canada (est. 1994) compares organic (ORG) vs. conventionally (CON) managed crop rotations in a loamy Typic Borall. Nitrogen (N) and phosphorus (P) deficiency in the ORG systems have limited crop growth and thus plant carbon (C) inputs for over two decades, ultimately resulting in a C deficiency which has further altered biogeochemical cycling. We conducted a short-term microcosm experiment using 13C-glucose stable isotope probing (SIP) of DNA to test whether ORG soils have greater microbial C use efficiency due to long term resource limitation. Glucose-utilizing populations were dominated by Proteobacteria and Actinobacteria, with differing species-level identities and physiological capacities between CON and ORG systems. Of the 13C-utilizing taxa, relative abundance of Proteobacteria was greater in CON while Actinobacteria (and notably Firmicutes) were more dominant in ORG soils. Using isothermal calorimetry, we measured a thermodynamic efficiency (ηeff) of 0.68, which was not significantly different between soils indicating that the metabolic cost of glucose utilization was similar in CON and ORG soils. In spite of this, differential abundance analysis of 13C-labelled OTUs revealed that ORG soils had distinct active bacterial populations that were positively correlated with ηeff, ηsoil (glucose energy retained in soil) and primed soil organic matter (pSOM). In contrast, differentially abundant OTUs in the CON soils were negatively correlated with measures of thermodynamic efficiency but positively correlated with glucose-derived heat and CO2 production as well as NO3- and PO4- availability. ORG bacterial communities may co-metabolize other resources (N and P) from SOM to meet their metabolic requirements during glucose utilization, while the active bacteria in the CON soils could access these

Contribution of Streptococcus mutans Strains with Collagen-Binding Proteins in the Presence of Serum to the Pathogenesis of Infective Endocarditis.

Science.gov (United States)

Otsugu, Masatoshi; Nomura, Ryota; Matayoshi, Saaya; Teramoto, Noboru; Nakano, Kazuhiko

2017-12-01

Streptococcus mutans , a major pathogen of dental caries, is considered one of the causative agents of infective endocarditis (IE). Recently, bacterial DNA encoding 120-kDa cell surface collagen-binding proteins (CBPs) has frequently been detected from S. mutans -positive IE patients. In addition, some of the CBP-positive S. mutans strains lacked a 190-kDa protein antigen (PA), whose absence strengthened the adhesion to and invasion of endothelial cells. The interaction between pathogenic bacteria and serum or plasma is considered an important virulence factor in developing systemic diseases; thus, we decided to analyze the pathogenesis of IE induced by S. mutans strains with different patterns of CBP and PA expression by focusing on the interaction with serum or plasma. CBP-positive (CBP + )/PA-negative (PA - ) strains showed prominent aggregation in the presence of human serum or plasma, which was significantly greater than that with CBP + /PA-positive (PA + ) and CBP-negative (CBP - )/PA+ strains. Aggregation of CBP + /PA - strains was also observed in the presence of a high concentration of type IV collagen, a major extracellular matrix protein in serum. In addition, aggregation of CBP + /PA - strains was drastically reduced when serum complement was inactivated. Furthermore, an ex vivo adherence model and an in vivo rat model of IE showed that extirpated heart valves infected with CBP + /PA - strains displayed prominent bacterial mass formation, which was not observed following infection with CBP + /PA + and CBP - /PA + strains. These results suggest that CBP + /PA - S. mutans strains utilize serum to contribute to their pathogenicity in IE. Copyright © 2017 American Society for Microbiology.

Quillaja saponaria Saponins with Potential to Enhance the Effectiveness of Disinfection Processes in the Beverage Industry

OpenAIRE

Hubert Antolak; Urszula Mizerska; Joanna Berłowska; Anna Otlewska; Dorota Kręgiel

2018-01-01

This study examines the in vitro effect of Quillaja saponaria extracts on Asaia spp. planktonic cells and biofilms, in comparison and combination with two disinfectants: peracetic acid and N-ethyl-N,N-dimethylhexadecylammonium bromide. The growth of six bacterial strains was evaluated spectrophotometrically. Biofilm eradication was determined using the plate count method and luminometry. The planktonic cells were characterized by relatively high resistance to peracetic acid and higher sensiti...

Once-daily glycopyrronium bromide (Seebri Breezhaler(®)) for the treatment of chronic obstructive pulmonary disease (COPD)

DEFF Research Database (Denmark)

Ulrik, Charlotte Suppli

2015-01-01

INTRODUCTION: Long-acting bronchodilators are the mainstay of pharmacological therapy for patients with chronic obstructive pulmonary disease (COPD). The choice of optimal bronchodilator therapy for COPD is increasingly difficult for clinicians as new treatments are marketed. AREAS COVERED: Inhaled...... glycopyrronium bromide (Seebri Breezhaler®) is a well-tolerated long-acting anti-muscarinic agent (LAMA) with a fast onset of action. In patients with moderate to severe COPD, glycopyrronium bromide has clinically important effects on level of FEV1, use of relief medication, day-time dyspnea scores, and probably...... also on health status. Furthermore, glycopyrronium bromide also has beneficial effects on dynamic hyperinflation and, probably by that, exercise tolerance. Glycopyrronium bromide has been shown to reduce the rate of exacerbations in patients with moderate to severe COPD, although as a secondary outcome...

Streptococcus mutans autolysin AtlA is a fibronectin-binding protein and contributes to bacterial survival in the bloodstream and virulence for infective endocarditis.

Science.gov (United States)

Jung, Chiau-Jing; Zheng, Quan-Hau; Shieh, Ya-Hsiung; Lin, Chi-Shuan; Chia, Jean-San

2009-11-01

Streptococcus mutans, a commensal of the human oral cavity, can survive in the bloodstream and cause infective endocarditis (IE). However, the virulence factors associated with this manifestation of disease are not known. Here, we demonstrate that AtlA, an autolysin of S. mutans is a newly identified fibronectin (Fn) binding protein and contributes to bacterial resistance to phagocytosis and survival in the bloodstream. Interestingly, prior exposure to plasma at low concentrations was sufficient to enhance bacterial survival in the circulation. Calcium ions at physiological plasma concentrations induced maturation of AtlA from the 104-90 kDa isoform resulting in increased Fn binding and resistance to phagocytosis. An isogenic mutant strain defective in AtlA expression exhibited reduced survival and virulence when tested in a rat model of IE compared with the wild-type and complemented strains. The data presented suggest that plasma components utilized by S. mutans enhanced survival in the circulation and AtlA is a virulence factor associated with infective endocarditis.

Strain-Modulated Epitaxy

National Research Council Canada - National Science Library

Brown, April

1999-01-01

Strain-Modulated Epitaxy (SME) is a novel approach, invented at Georgia Tech, to utilize subsurface stressors to control strain and therefore material properties and growth kinetics in the material above the stressors...

Control of insects with fumigants at low temperatures: toxicity of mixtures of methyl bromide and acrylonitrile to three species of insects

Energy Technology Data Exchange (ETDEWEB)

Bond, E.J.; Buckland, C.T.

1976-12-15

Acrylonitrile can be mixed with methyl bromide to increase toxicity so that the quantity of methyl bromide required for control of Sitophilus granarius (L.), Tenebrio molitor L., and Tribolium confusum Jacquelin duval is reduced by one half. Mixtures of methyl bromide and acrylonitrile are considerably more effective at low temperatures than methyl bromide alone.

Role of overexpressed CFA/I fimbriae in bacterial swimming

International Nuclear Information System (INIS)

Cao, Ling; Lim, Timothy; Jun, SangMu; Riccardi, Carol; Yang, Xinghong; Suo, Zhiyong; Deliorman, Muhammedin; Kellerman, Laura; Avci, Recep

2012-01-01

Enterotoxigenic Escherichia coli CFA/I is a protective antigen and has been overexpressed in bacterial vectors, such as Salmonella Typhimurium H683, to generate vaccines. Effects that overexpressed CFA/I may engender on the bacterial host remain largely unexplored. To investigate, we constructed a high CFA/I expression strain, H683-pC2, and compared it to a low CFA/I expression strain, H683-pC, and to a non-CFA/I expression strain, H683-pY. The results showed that H683-pC2 was less able to migrate into semisolid agar (0.35%) than either H683-pC or H683-pY. Bacteria that migrated showed motility halo sizes of H683-pC2 < H683-pC < H683-pY. In the liquid culture media, H683-pC2 cells precipitated to the bottom of the tube, while those of H683-pY did not. In situ imaging revealed that H683-pC2 bacilli tended to auto-agglutinate within the semisolid agar, while H683-pY bacilli did not. When the cfaBE fimbrial fiber encoding genes were deleted from pC2, the new plasmid, pC2(-), significantly recovered bacterial swimming capability. Our study highlights the negative impact of overexpressed CFA/I fimbriae on bacterial swimming motility. (paper)

Bacterial Population Genetics in a Forensic Context

Energy Technology Data Exchange (ETDEWEB)

Velsko, S P

2009-11-02

This report addresses the recent Department of Homeland Security (DHS) call for a Phase I study to (1) assess gaps in the forensically relevant knowledge about the population genetics of eight bacterial agents of concern, (2) formulate a technical roadmap to address those gaps, and (3) identify new bioinformatics tools that would be necessary to analyze and interpret population genetic data in a forensic context. The eight organisms that were studied are B. anthracis, Y. pestis, F. tularensis, Brucella spp., E. coli O157/H7, Burkholderia mallei, Burkholderia pseudomallei, and C. botulinum. Our study focused on the use of bacterial population genetics by forensic investigators to test hypotheses about the possible provenance of an agent that was used in a crime or act of terrorism. Just as human population genetics underpins the calculations of match probabilities for human DNA evidence, bacterial population genetics determines the level of support that microbial DNA evidence provides for or against certain well-defined hypotheses about the origins of an infecting strain. Our key findings are: (1) Bacterial population genetics is critical for answering certain types of questions in a probabilistic manner, akin (but not identical) to 'match probabilities' in DNA forensics. (2) A basic theoretical framework for calculating likelihood ratios or posterior probabilities for forensic hypotheses based on microbial genetic comparisons has been formulated. This 'inference-on-networks' framework has deep but simple connections to the population genetics of mtDNA and Y-STRs in human DNA forensics. (3) The 'phylogeographic' approach to identifying microbial sources is not an adequate basis for understanding bacterial population genetics in a forensic context, and has limited utility, even for generating 'leads' with respect to strain origin. (4) A collection of genotyped isolates obtained opportunistically from international locations

Electrolytic coloration and spectral properties of hydroxyl-doped potassium bromide single crystals

International Nuclear Information System (INIS)

Qi, Lan; Song, Cuiying; Gu, Hongen

2013-01-01

Hydroxyl-doped potassium bromide single crystals are colored electrolytically at various temperatures and voltages by using a pointed cathode and a flat anode. The characteristic OH − spectral band is observed in absorption spectrum of uncolored single crystal. The characteristic O − , OH − , U, V 2 , O 2− −V a + , M L1 , F and M spectral bands are observed simultaneously in absorption spectra of colored single crystals. Current–time curve for electrolytic coloration of hydroxyl-doped potassium bromide single crystal and its relationship with electrolytic coloration processes are given. Production and conversion of color centers are explained. - Highlights: ► We expanded the traditional electrolysis method. ► Hydroxyl-doped potassium bromide crystals were colored electrolytically for the first time. ► Useful V, F and F-aggregate color centers were produced in colored crystals. ► V color centers were produced directly and F as well as F-aggregate color centers indirectly.

Endophytic and epiphytic hydrocarbon-utilizing bacteria associated with root nodules of legumes

International Nuclear Information System (INIS)

Dashti, N.; Khanafer, M.; Radwan, S.S.

2005-01-01

During their withdrawal from Kuwait in 1991, the Iraqi forces damaged and set fire to approximately 700 oil wells. Oil gushed from the wells for a period of 7 months, resulting in oil lakes which covered about 50 square km of the Kuwaiti desert and posing an environmental problem. Most of the crude oil has been pumped out, leaving the lake bottoms polluted with oil to depths reaching 20 to 25 cm. The oily areas have been mediated through indigenous hydrocarbon-utilizing microorganisms, but recovery is slow. Rhizospheres of crop plants, including legumes, are rich in oil-utilizing bacteria. Cultivation of broad beans in oily desert samples has enhanced oil biodegradation. This paper discussed the evidence that rhizobium strains inside the nodules on roots of broad beans are active in hydrocarbon utilization, and that the nodules are also colonized on their entire surfaces with oil-utilizing bacteria. Nodule-associated hydrocarbon utilizers appear to contribute together with rhizospheric hydrocarbon utilizers to the phytoremediation of oily soil. Broad beans were removed from soil and their root surfaces were sterilized to eliminate rhizospheric microorganisms. Plants with intact nodules were tested for their potential of attenuating to crude oil in water. Plants were divided into 2 groups: control plants in which all nodules were removed; and experimental plants which were used directly without further treatment. To isolate rhizobium from inside the nodules, fresh nodules were washed, sterilized and homogenized in sterile water. Bacterial strains were tested for their hydrocarbon utilization potential by streaking cell suspensions on the surface of sterile inorganic mediums containing 1 per cent of crude oil or of individual pure aliphatic and aromatic test hydrocarbons. All bacterial isolates were tested for growth on a solid Ashbery's nitrogen free medium. Results indicated that hydrocarbons were more efficiently eliminated from water supporting disinfected

Pentafluorobenzyl bromide-A versatile derivatization agent in chromatography and mass spectrometry: I. Analysis of inorganic anions and organophosphates.

Science.gov (United States)

Tsikas, Dimitrios

2017-02-01

Pentafluorobenzyl bromide (PFB-Br) is a versatile derivatization agent. It is widely used in chromatography and mass spectrometry since several decades. The bromide atom is largely the single leaving group of PFB-Br. It is substituted by wide a spectrum of nucleophiles in aqueous and non-aqueous systems to form electrically neutral, in most organic solvents soluble, generally thermally stable, volatile, strongly electron-capturing and ultraviolet light-absorbing derivatives. Because of these greatly favoured physicochemical properties, PFB-Br emerged an ideal derivatization agent for highly sensitive analysis of endogenous and exogenous substances including various inorganic and organic anions by electron capture detection or after electron-capture negative-ion chemical ionization in GC-MS. The present article attempts an appraisal of the utility of PFB-Br in analytical chemistry. It reviews and discusses papers dealing with the use of PFB-Br as the derivatization reagent in the qualitative and quantitative analysis of endogenous and exogenous inorganic anions in various biological samples, notably plasma, urine and saliva. These analytes include nitrite, nitrate, cyanide and dialkyl organophosphates. Special emphasis is given to mass spectrometry-based approaches and stable-isotope dilution techniques. Copyright © 2016 Elsevier B.V. All rights reserved.

The effect of iatrogenic Staphylococcus epidermidis intercellar adhesion operon on the formation of bacterial biofilm on polyvinyl chloride surfaces.

Science.gov (United States)

Lianhua, Ye; Yunchao, Huang; Guangqiang, Zhao; Kun, Yang; Xing, Liu; Fengli, Guo

2014-12-01

The intercellular adhesion gene (ica) of Staphylococcus epidermidis is a key factor for bacterial aggregation. This study explored the effect of ica on the formation of bacterial biofilm on polyvinyl chloride (PVC) surfaces. Genes related to bacterial biofilm formation, including 16S rRNA, autolysin (atlE), fibrinogen binding protein gene (fbe), and ica were identified and sequenced from 112 clinical isolates of iatrogenic S. epidermidis by polymerase chain reaction (PCR) and gene sequencing. Based on the sequencing result, ica operon-positive (icaADB+/atlE+/fbe+) and ica operon-negative (icaADB-/atlE+/fbe+) strains were separated and co-cultivated with PVC material. After 6, 12, 18, 24, and 30 h of co-culture, the thickness of the bacterial biofilm and quantity of bacterial colony on the PVC surface were measured under the confocal laser scanning microscope and scanning electron microscope. The positive rate of S. epidermidis-specific 16SrRNA in 112 iatrogenic strains was 100% (112/112). The genotype of ica-positive (icaADB+/atlE+/fbe+) strains accounted for 57.1% (64/112), and genotype of ica-negative (icaADB-/atlE+/fbe+) strains accounted for 37.5% (42/112). During 30 h of co-culture, no obvious bacterial biofilm formed on the surface of PVC in the ica-positive group, however, mature bacterial biofilm structure formed after 24 h. For all time points, thickness of bacterial biofilm and quantity of bacterial colony on PVC surfaces in the ica operon-positive group were significantly higher than those in ica operon-negative group (poperon-negative and ica operon-positive strains. The ica operon plays an important role in bacterial biofilm formation and bacterial multiplication on PVC material.

Bacterially Induced Weathering of Ultramafic Rock and Its Implications for Phytoextraction

Science.gov (United States)

Kidd, Petra; Kuffner, Melanie; Prieto-Fernández, Ángeles; Hann, Stephan; Monterroso, Carmela; Sessitsch, Angela; Wenzel, Walter; Puschenreiter, Markus

2013-01-01

The bioavailability of metals in soil is often cited as a limiting factor of phytoextraction (or phytomining). Bacterial metabolites, such as organic acids, siderophores, or biosurfactants, have been shown to mobilize metals, and their use to improve metal extraction has been proposed. In this study, the weathering capacities of, and Ni mobilization by, bacterial strains were evaluated. Minimal medium containing ground ultramafic rock was inoculated with either of two Arthrobacter strains: LA44 (indole acetic acid [IAA] producer) or SBA82 (siderophore producer, PO4 solubilizer, and IAA producer). Trace elements and organic compounds were determined in aliquots taken at different time intervals after inoculation. Trace metal fractionation was carried out on the remaining rock at the end of the experiment. The results suggest that the strains act upon different mineral phases. LA44 is a more efficient Ni mobilizer, apparently solubilizing Ni associated with Mn oxides, and this appeared to be related to oxalate production. SBA82 also leads to release of Ni and Mn, albeit to a much lower extent. In this case, the concurrent mobilization of Fe and Si indicates preferential weathering of Fe oxides and serpentine minerals, possibly related to the siderophore production capacity of the strain. The same bacterial strains were tested in a soil-plant system: the Ni hyperaccumulator Alyssum serpyllifolium subsp. malacitanum was grown in ultramafic soil in a rhizobox system and inoculated with each bacterial strain. At harvest, biomass production and shoot Ni concentrations were higher in plants from inoculated pots than from noninoculated pots. Ni yield was significantly enhanced in plants inoculated with LA44. These results suggest that Ni-mobilizing inoculants could be useful for improving Ni uptake by hyperaccumulator plants. PMID:23793627

Isolation and characterization of a novel 2-methyl-4-chlorophenoxyacetic acid-degrading Enterobacter sp. strain SE08.

Science.gov (United States)

Tan, Lin; Hu, Qiulong; Xiong, Xingyao; Su, Xiaojun; Huang, Yanning; Jiang, Ziwei; Zhou, Qingming; Zhao, Songyi; Zeng, Wei-ai

2013-10-01

A bacterial strain (SE08) capable of utilizing 2-methyl-4-chlorophenoxy acetic acid (MCPA) as the sole carbon and energy source for growth was isolated by continuous enrichment culturing in minimal salt medium (MSM) from a long term MCPA exposed soil. This bacterial strain was identified as Enterobacter sp. based on morphological, physiological and biochemical tests, as well as 16S rRNA sequence analysis. Its ability to degrade MCPA was determined using high performance liquid chromatography. The strain SE08 can tolerate unusually high MCPA concentrations (125-2000mg/L). The influences of culturing factors (initial concentration, pH, and temperature) on the bacterial growth and substrate degradation were studied. The results showed that the optimal MCPA degradation occurred at an MCPA concentration of 500mg/L, 30°C and pH 6.0. Under these conditions, 68.5 percent of MCPA in MSM was degraded by SE08, and the OD600nm reached 0.64 after culturing for 72h. The degradation of MCPA could be enhanced by addition of both carbon and nitrogen sources. At an initial MCPA concentration of 500mg/L, when 5g/L glucose and 2.5g/L yeast extract were added into the MSM media, the MCPA degradation was significantly increased to 83.8 percent, and OD600nm was increased to 1.09 after incubation at 30°C and pH 6.0 for 72h. This is the first study showing that an Enterobacter sp. strain is capable of degrading MCPA, which might provide a new approach for the remediation of MCPA contaminated soil and contribute to the limited knowledge about the function of Enterobacter species. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

Characterization of Bacteria Isolation of Bacteria from Pinyon Rhizosphere,

Science.gov (United States)

2016-01-01

Two hundred and fifty bacterial strains were isolated from pinyon rhizosphere and screened for biosurfactants production. Among them, six bacterial strains were selected for their potential to produce biosurfactants using two low cost wastes, crude glycerol and lactoserum, as raw material. Both wastes were useful for producing biosurfactants because of their high content in fat and carbohydrates. The six strains were identified by 16S rDNA with an identity percentage higher than 95%, three strains belonged to Enterobacter sp., Pseudomonas aeruginosa, Bacillus pumilus and Rhizobium sp. All strains assayed were able to grow and showed halos around the colonies as evidence of biosurfactants production on Cetyl Trimethyl Ammonium Bromide agar with crude glycerol and lactoserum as substrate. In a mineral salt liquid medium enriched with both wastes, the biosurfactants were produced and collected from free cell medium after 72 h incubation. The biosurfactants produced reduced the surface tension from 69 to 30 mN/m with an emulsification index of diesel at approximately 60%. The results suggest that biosurfactants produced by rhizosphere bacteria from pinyon have promising environmental applications.

Subsurface associations of Acaryochloris-related picocyanobacteria with oil-utilizing bacteria in the Arabian Gulf water body: promising consortia in oil sediment bioremediation.

Science.gov (United States)

Al-Bader, Dhia; Eliyas, Mohamed; Rayan, Rihab; Radwan, Samir

2013-04-01

Two picocyanobacterial strains related to Acaryochloris were isolated from the Arabian Gulf, 3 m below the water surface, one from the north shore and the other from the south shore of Kuwait. Both strains were morphologically, ultrastructurally, and albeit to a less extend, phylogenetically similar to Acaryochloris. However, both isolates lacked chlorophyll d and produced instead chlorophyll a, as the major photosynthetic pigment. Both picocyanobacterial isolates were associated with oil-utilizing bacteria in the magnitude of 10(5) cells g(-1). According to their 16S rRNA gene sequences, bacteria associated with the isolate from the north were affiliated to Paenibacillus sp., Bacillus pumilus, and Marinobacter aquaeolei, but those associated with the isolate from the south were affiliated to Bacillus asahii and Alcanivorax jadensis. These bacterial differences were probably due to environmental variations. In batch cultures, the bacterial consortia in the nonaxenic biomass as well as the pure bacterial isolates effectively consumed crude oil and pure aliphatic and aromatic hydrocarbons, including very high-molecular-weight compounds. Water and diethylether extracts from the phototrophic biomass enhanced growth of individual bacterial isolates and their hydrocarbon-consumption potential in batch cultures. It was concluded that these consortia could be promising in bioremediation of hydrocarbon pollutants, especially heavy sediments in the marine ecosystem.

[Behavior of different strains of Staphylococcus aureus against root canal filling cements].

Science.gov (United States)

Pumarola, J; Berástegui, E; Canalda, C; Brau, E

1991-01-01

The mean goal of this study is the determination of the conduct of 120 strains of Staphylococcus aureus against seven root canal sealers: Traitement Spad, Endométhasone, N2 Universal, AH26 with silver, Diaket-A, Tubli Seal and Sealapex. The agar diffusion test was employed in the determination of its bacterial growth inhibition. The results obtained have demonstrated values very different between the tested strains. Therefore we recommended to employ strains with reference in the investigation of the bacterial growth inhibition in order to repeat equal experimentation conditions.

Utilization of chitinolytic bacterial isolates to control anthracnose of ...

African Journals Online (AJOL)

SAM

2014-04-09

Apr 9, 2014 ... Assay of antagonistic bacterial chitinolytic to C. gloeosporioides was ... 1632 Afr. J. Biotechnol. ... microorganisms, by their interactions with various plant ... ristics such as colony, mycelia as well as shape and size of conidia.

Tribromoisocyanuric acid/triphenylphosphine: a new system for conversion of alcohols into alkyl bromides

Energy Technology Data Exchange (ETDEWEB)

Andrade, Vitor S.C. de; Mattos, Marcio C.S. de, E-mail: mmattos@iq.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Instituto de Quimica. Departamento de Quimica Organica

2014-05-15

An efficient and facile method has been developed for the conversion of alcohols into alkyl bromides under neutral conditions using tribromoisocyanuric acid and triphenylphosphine (molar ratio 1.0:0.7:2.0, alcohol/tribromoisocyanuric acid/triphenylphosphine) in dichloromethane at room temperature. This method can be applied for the conversion of primary, secondary, benzilic and allylic alcohols, and their corresponding bromides are obtained in 67-82 % yield. Tertiary alcohols do not react under these conditions. (author)

Tribromoisocyanuric acid/triphenylphosphine: a new system for conversion of alcohols into alkyl bromides

International Nuclear Information System (INIS)

Andrade, Vitor S.C. de; Mattos, Marcio C.S. de

2014-01-01

An efficient and facile method has been developed for the conversion of alcohols into alkyl bromides under neutral conditions using tribromoisocyanuric acid and triphenylphosphine (molar ratio 1.0:0.7:2.0, alcohol/tribromoisocyanuric acid/triphenylphosphine) in dichloromethane at room temperature. This method can be applied for the conversion of primary, secondary, benzilic and allylic alcohols, and their corresponding bromides are obtained in 67-82 % yield. Tertiary alcohols do not react under these conditions. (author)

Directed antigen delivery as a vaccine strategy for an intracellular bacterial pathogen

Science.gov (United States)

Bouwer, H. G. Archie; Alberti-Segui, Christine; Montfort, Megan J.; Berkowitz, Nathan D.; Higgins, Darren E.

2006-03-01

We have developed a vaccine strategy for generating an attenuated strain of an intracellular bacterial pathogen that, after uptake by professional antigen-presenting cells, does not replicate intracellularly and is readily killed. However, after degradation of the vaccine strain within the phagolysosome, target antigens are released into the cytosol for endogenous processing and presentation for stimulation of CD8+ effector T cells. Applying this strategy to the model intracellular pathogen Listeria monocytogenes, we show that an intracellular replication-deficient vaccine strain is cleared rapidly in normal and immunocompromised animals, yet antigen-specific CD8+ effector T cells are stimulated after immunization. Furthermore, animals immunized with the intracellular replication-deficient vaccine strain are resistant to lethal challenge with a virulent WT strain of L. monocytogenes. These studies suggest a general strategy for developing safe and effective, attenuated intracellular replication-deficient vaccine strains for stimulation of protective immune responses against intracellular bacterial pathogens. CD8+ T cell | replication-deficient | Listeria monocytogenes

COMPARISON OF ROCURONIUM BROMIDE AND SUCCINYLCHOLINE CHLORIDE FOR USE DURING RAPID SEQUENCE INTUBATION IN ADULTS

Directory of Open Access Journals (Sweden)

Ch. Penchalaiah

2015-08-01

Full Text Available BACKGROUND AND OBJECTIVE : The goal of rapid sequence intubation is to secure the patients airway smoothly and quickly, minimizing the chances of regurgitation and aspiration of gastric contents. Traditionally succinylcholine chloride has been the neuromuscular blocking drug of choi ce for use in rapid sequence intubation because of its rapid onset of action and profound relaxation. Succinylcholine chloride remains unsurpassed in providing ideal intubating conditions. However the use of succinylcholine chloride is associated with many side effects like muscle pain, bradycardia, hyperkalaemia and rise in intragastric and intraocular pressure. Rocuronium bromide is the only drug currently available which has the rapidity of onset of action like succinylcholine chloride. Hence the present study was undertaken to compare rocuronium bromide with succinylcholine chloride for use during rapid sequence intubation in adult patients. METHODOLOGY : The study population consisted of 90 patients aged between 18 - 60 years posted for various elective su rgeries requiring general anaesthesia . S tudy population was randomly divided into 3 groups with 30 patients in each sub group. 1. Group I : Intubated with 1 mg kg - 1 of succinylcholine chloride (n=30 . 2. Grou p II : Intubated with rocuronium bromide 0.6 mg kg - 1 (n=30 . 3. Group III : Intubated with rocuronium bromide 0.9 mg kg - 1 (n=30 . Intubating conditions were assessed at 60 seconds based on the scale adopted by Toni Magorian et al. 1993. The haemodynamic para meters in the present study were compared using p - value obtained from student t - test . RESULTS : It was noted that succinylcholine chloride 1 mg kg - 1 body weight produced excellent intubating conditions in all patients. Rocuronium bromide 0.6 mg kg - 1 body we ight produced excellent intubating conditions in 53.33% of patients but produced good to excellent intubating conditions in 96.67% of patients. Rocuronium bromide 0.9 mg kg - 1

Vapour pressures, densities, and viscosities of the (water + lithium bromide + potassium acetate) system and (water + lithium bromide + sodium lactate) system

International Nuclear Information System (INIS)

Lucas, Antonio de; Donate, Marina; Rodriguez, Juan F.

2006-01-01

Measurements of thermophysical properties (vapour pressure, density, and viscosity) of the (water + lithium bromide + potassium acetate) system LiBr:CH 3 COOK = 2:1 by mass ratio and the (water + lithium bromide + sodium lactate) system LiBr:CH 3 CH(OH)COONa = 2:1 by mass ratio were measured. The system, a possible new working fluid for absorption heat pump, consists of absorbent (LiBr + CH 3 COOK) or (LiBr + CH 3 CH(OH)COONa) and refrigerant H 2 O. The vapour pressures were measured in the ranges of temperature and absorbent concentration from T = (293.15 to 333.15) K and from mass fraction 0.20 to 0.50, densities and viscosities were measured from T = (293.15 to 323.15) K and from mass fraction 0.20 to 0.40. The experimental data were correlated with an Antoine-type equation. Densities and viscosities were measured in the same range of temperature and absorbent concentration as that of the vapour pressure. Regression equations for densities and viscosities were obtained with a minimum mean square error criterion

Characterization of CCN and IN activity of bacterial isolates collected in Atlanta, GA

Science.gov (United States)

Purdue, Sara; Waters, Samantha; Karthikeyan, Smruthi; Konstantinidis, Kostas; Nenes, Athanasios

2016-04-01

Characterization of CCN activity of bacteria, other than a few select types such as Pseudomonas syringae, is limited, especially when looked at in conjunction with corresponding IN activity. The link between these two points is especially important for bacteria as those that have high CCN activity are likely to form an aqueous phase required for immersion freezing. Given the high ice nucleation temperature of bacterial cells, especially in immersion mode, it is important to characterize the CCN and IN activity of many different bacterial strains. To this effect, we developed a droplet freezing assay (DFA) which consists of an aluminum cold plate, cooled by a continuous flow of an ethylene glycol-water mixture, in order to observe immersion freezing of the collected bacteria. Here, we present the initial results on the CCN and IN activities of bacterial samples we have collected in Atlanta, GA. Bacterial strains were collected and isolated from rainwater samples taken from different storms throughout the year. We then characterized the CCN activity of each strain using a DMT Continuous Flow Streamwise Thermal Gradient CCN Counter by exposing the aerosolized bacteria to supersaturations ranging from 0.05% to 0.6%. Additionally, using our new DFA, we characterized the IN activity of each bacterial strain at temperatures ranging from -20oC to 0oC. The combined CCN and IN activity gives us valuable information on how some uncharacterized bacteria contribute to warm and mixed-phase cloud formation in the atmosphere.

Evaluation of repetitive-PCR and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for rapid strain typing of Bacillus coagulans.

Science.gov (United States)

Sato, Jun; Nakayama, Motokazu; Tomita, Ayumi; Sonoda, Takumi; Hasumi, Motomitsu; Miyamoto, Takahisa

2017-01-01

In order to establish rapid and accurate typing method for Bacillus coagulans strains which is important for controlling in some canned foods and tea-based beverages manufacturing because of the high-heat resistance of the spores and high tolerance of the vegetative cells to catechins and chemicals, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and repetitive-PCR (rep-PCR) were evaluated. For this purpose, 28 strains of B. coagulans obtained from various culture collections were tested. DNA sequence analyses of the genes encoding 16S rRNA and DNA gyrase classified the test strains into two and three groups, respectively, regardless of their phenotypes. Both MALDI-TOF MS and rep-PCR methods classified the test strains in great detail. Strains classified in each group showed similar phenotypes, such as carbohydrate utilization determined using API 50CH. In particular, the respective two pairs of strains which showed the same metabolic characteristic were classified into the same group by both MALDI-TOF MS and rep-PCR methods separating from the other strains. On the other hand, the other strains which have the different profiles of carbohydrate utilization were separated into different groups by these methods. These results suggested that the combination of MALDI-TOF MS and rep-PCR analyses was advantageous for the rapid and detailed typing of bacterial strains in respect to both phenotype and genotype.

Biomimetic synthesis of selenium nanospheres by bacterial strain JS-11 and its role as a biosensor for nanotoxicity assessment: a novel se-bioassay.

Science.gov (United States)

Dwivedi, Sourabh; Alkhedhairy, Abdulaziz A; Ahamed, Maqusood; Musarrat, Javed

2013-01-01

Selenium nanoparticles (Se-NPs) were synthesized by green technology using the bacterial isolate Pseudomonas aeruginosa strain JS-11. The bacteria exhibited significant tolerance to selenite (SeO3(2-)) up to 100 mM concentration with an EC50 value of 140 mM. The spent medium (culture supernatant) contains the potential of reducing soluble and colorless SeO3(2-) to insoluble red elemental selenium (Se(0)) at 37°C. Characterization of red Se° product by use of UV-Vis spectroscopy, X-ray diffraction (XRD), atomic force microscopy (AFM) and transmission electron microscopy (TEM) with energy dispersive X-ray spectrum (EDX) analysis revealed the presence of stable, predominantly monodispersed and spherical selenium nanoparticles (Se-NPs) of an average size of 21 nm. Most likely, the metabolite phenazine-1-carboxylic acid (PCA) released by strain JS-11 in culture supernatant along with the known redox agents like NADH and NADH dependent reductases are responsible for biomimetic reduction of SeO3(2-) to Se° nanospheres. Based on the bioreduction of a colorless solution of SeO3(2-) to elemental red Se(0), a high throughput colorimetric bioassay (Se-Assay) was developed for parallel detection and quantification of nanoparticles (NPs) cytotoxicity in a 96 well format. Thus, it has been concluded that the reducing power of the culture supernatant of strain JS-11 could be effectively exploited for developing a simple and environmental friendly method of Se-NPs synthesis. The results elucidated that the red colored Se° nanospheres may serve as a biosensor for nanotoxicity assessment, contemplating the inhibition of SeO3(2-) bioreduction process in NPs treated bacterial cell culture supernatant, as a toxicity end point.

Removal of bromide from aqueous solutions using the UV/ZnO process based on the multivariate analysis model

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Kolsoom Mohammad Moradi

2017-02-01

Full Text Available Background: Bromide is found naturally in groundwater and surface water. The rapid growth of industrial activities, drainage of surface runoff, and use of methyl bromide in pesticides has increased bromide discharge to the environment. Disinfection of water-containing bromide causes the creation of additional products of organo-halogenated that are considered cancer-causing agents. In this study, the effect and optimization of factors in removal of this ion was evaluated by using the nano-photocatalytic UV/ZnO process. Methods: This analytical study was conducted in a batch system by the phenol-red method. The test design was performed through the analysis model of multi-factor variance with 99 subjects, while the main, interactive, and reciprocal effects of variables, such as reaction time, catalyst concentration, bromide concentration, and pH at different levels of each factor, were analysed by using SPSS version 16. Results: The main, interactive, and reciprocal effects of factors were significant in three different levels with P < 0.001, and the optimal level of the factors reaction time, catalyst concentration, bromide concentration, and pH were 120 minutes, 0.5, 0.1, and 7 mg/L, respectively, by using the Schaffer test. The highest removal efficiency of 95% was obtained at least 91.56 and a maximum of 94.76% was obtained under optimal conditions of all factors. Conclusion: The results show that by optimization of factors, this process can be effectively used to remove bromide from aquatic environments.

Proanthocyanidins-Will they effectively restrain conspicuous bacterial strains devolving on urinary tract infection?

Science.gov (United States)

Jagannathan, Venkataseshan; Viswanathan, Pragasam

2018-05-18

Struvite or infection stones are one of the major clinical burdens among urinary tract infection, which occur due to the interaction between microbes and urine mineral components. Numerous urinary tract infection (UTI) causing microbes regulate through biofilm formation for survival from host defense, it is often found difficult in its eradication with simple anti-microbial agents and also the chance of recurrence and resistance development is significantly high. Cranberry consumption and maintenance of urinary tract health have been supported by clinical, epidemiological, and mechanistic studies. It predominantly contains proanthocyanidins that belong to the class of polyphenols with repeating catechin and epicatechin monomeric units. Numerous studies have correlated proanthocyanidin consumption and prevention of bacterial adhesion to uroepithelial cells. Quorum sensing (QS) is the prime mechanism that drives bacteria to coordinate biofilm development and virulence expression. Reports have shown that proanthocyanidins are effective in disrupting cell-cell communication by quenching signal molecules. Overall, this review assesses the merits of proanthocyanidins and its effective oppression on adherence, motility, QS, and biofilm formation of major UTI strains such as Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis by comparing and evaluating results from many significant findings. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Application of two bacterial strains for wastewater bioremediation and assessment of phenolics biodegradation.

Science.gov (United States)

Paisio, Cintia E; Quevedo, María R; Talano, Melina A; González, Paola S; Agostini, Elizabeth

2014-08-01

The use of native bacteria is a useful strategy to decontaminate industrial effluents. In this work, two bacterial strains isolated from polluted environments constitutes a promising alternative since they were able to remove several phenolic compounds not only from synthetic solutions but also from effluents derived from a chemical industry and a tannery which are complex matrices. Acinetobacter sp. RTE 1.4 showed ability to completely remove 2-methoxyphenol (1000 mg/L) while Rhodococcus sp. CS 1 not only degrade the same concentration of this compound but also removed 4- chlorophenol, 2,4-dichlorophenol and pentachlorophenol with high efficiency. Moreover, both bacteria degraded phenols naturally present or even exogenously added at high concentrations in effluents from the chemical industry and a tannery in short time (up to 5 d). In addition, a significant reduction of biological oxygen demand and chemical oxygen demand values was achieved after 7 d of treatment for both effluents using Acinetobacter sp. RTE 1.4 and Rhodococcus sp. CS1, respectively. These results showed that Acinetobacter sp. RTE1.4 and Rhodococcus sp. CS 1 might be considered as useful biotechnological tools for an efficient treatment of different effluents, since they showed wide versatility to detoxify these complex matrices, even supplemented with high phenol concentrations.

Encyclopedia of bacterial gene circuits whose presence or absence correlate with pathogenicity--a large-scale system analysis of decoded bacterial genomes.

Science.gov (United States)

Shestov, Maksim; Ontañón, Santiago; Tozeren, Aydin

2015-10-13

Bacterial infections comprise a global health challenge as the incidences of antibiotic resistance increase. Pathogenic potential of bacteria has been shown to be context dependent, varying in response to environment and even within the strains of the same genus. We used the KEGG repository and extensive literature searches to identify among the 2527 bacterial genomes in the literature those implicated as pathogenic to the host, including those which show pathogenicity in a context dependent manner. Using data on the gene contents of these genomes, we identified sets of genes highly abundant in pathogenic but relatively absent in commensal strains and vice versa. In addition, we carried out genome comparison within a genus for the seventeen largest genera in our genome collection. We projected the resultant lists of ortholog genes onto KEGG bacterial pathways to identify clusters and circuits, which can be linked to either pathogenicity or synergy. Gene circuits relatively abundant in nonpathogenic bacteria often mediated biosynthesis of antibiotics. Other synergy-linked circuits reduced drug-induced toxicity. Pathogen-abundant gene circuits included modules in one-carbon folate, two-component system, type-3 secretion system, and peptidoglycan biosynthesis. Antibiotics-resistant bacterial strains possessed genes modulating phagocytosis, vesicle trafficking, cytoskeletal reorganization, and regulation of the inflammatory response. Our study also identified bacterial genera containing a circuit, elements of which were previously linked to Alzheimer's disease. Present study produces for the first time, a signature, in the form of a robust list of gene circuitry whose presence or absence could potentially define the pathogenicity of a microbiome. Extensive literature search substantiated a bulk majority of the commensal and pathogenic circuitry in our predicted list. Scanning microbiome libraries for these circuitry motifs will provide further insights into the complex

Novel Acetone Metabolism in a Propane-Utilizing Bacterium, Gordonia sp. Strain TY-5▿

Science.gov (United States)

Kotani, Tetsuya; Yurimoto, Hiroya; Kato, Nobuo; Sakai, Yasuyoshi

2007-01-01

In the propane-utilizing bacterium Gordonia sp. strain TY-5, propane was shown to be oxidized to 2-propanol and then further oxidized to acetone. In this study, the subsequent metabolism of acetone was studied. Acetone-induced proteins were found in extracts of cells induced by acetone, and a gene cluster designated acmAB was cloned on the basis of the N-terminal amino acid sequences of acetone-induced proteins. The acmA and acmB genes encode a Baeyer-Villiger monooxygenase (BVMO) and esterase, respectively. The BVMO encoded by acmA was purified from acetone-induced cells of Gordonia sp. strain TY-5 and characterized. The BVMO exhibited NADPH-dependent oxidation activity for linear ketones (C3 to C10) and cyclic ketones (C4 to C8). Escherichia coli expressing the acmA gene oxidized acetone to methyl acetate, and E. coli expressing the acmB gene hydrolyzed methyl acetate. Northern blot analyses revealed that polycistronic transcription of the acmAB gene cluster was induced by propane, 2-propanol, and acetone. These results indicate that the acmAB gene products play an important role in the metabolism of acetone derived from propane oxidation and clarify the propane metabolism pathway of strain TY-5 (propane → 2-propanol → acetone → methyl acetate → acetic acid + methanol). This paper provides the first evidence for BVMO-dependent acetone metabolism. PMID:17071761

Bacterial Cheating Limits the Evolution of Antibiotic Resistance

Science.gov (United States)

Yurtsev, Eugene; Xiao Chao, Hui; Datta, Manoshi; Artemova, Tatiana; Gore, Jeff

2012-02-01

The emergence of antibiotic resistance in bacteria is a significant health concern. Bacteria can gain resistance to the antibiotic ampicillin by acquiring a plasmid carrying the gene beta-lactamase, which inactivates the antibiotic. This inactivation may represent a cooperative behavior, as the entire bacterial population benefits from removal of the antibiotic. The presence of a cooperative mechanism of resistance suggests that a cheater strain - which does not contribute to breaking down the antibiotic - may be able to take advantage of resistant cells. We find experimentally that a ``sensitive'' bacterial strain lacking the plasmid conferring resistance can invade a population of resistant bacteria, even in antibiotic concentrations that should kill the sensitive strain. We use a simple model in conjunction with difference equations to explain the observed population dynamics as a function of cell density and antibiotic concentration. Our experimental difference equations resemble the logistic map, raising the possibility of oscillations or even chaotic dynamics.

Antibiotic resistance of bacterial biofilms

DEFF Research Database (Denmark)

Hoiby, N.; Bjarnsholt, T.; Givskov, M.

2010-01-01

A biofilm is a structured consortium of bacteria embedded in a self-produced polymer matrix consisting of polysaccharide, protein and DNA. Bacterial biofilms cause chronic infections because they show increased tolerance to antibiotics and disinfectant chemicals as well as resisting phagocytosis...... and other components of the body's defence system. The persistence of, for example, staphylococcal infections related to foreign bodies is due to biofilm formation. Likewise, chronic Pseudomonas aeruginosa lung infection in cystic fibrosis patients is caused by biofilm-growing mucoid strains....... Characteristically, gradients of nutrients and oxygen exist from the top to the bottom of biofilms and these gradients are associated with decreased bacterial metabolic activity and increased doubling times of the bacterial cells; it is these more or less dormant cells that are responsible for some of the tolerance...

A novel explicit approach to model bromide and pesticide transport in soils containing macropores

Science.gov (United States)

Klaus, J.; Zehe, E.

2011-01-01

The present study tests whether an explicit treatment of worm burrows is feasible for simulating water flow, bromide and pesticide transport in structured heterogeneous soils. The essence is to represent worm burrows as morphologically connected paths of low flow resistance in the spatially highly resolved model domain. A recent Monte Carlo study (Klaus and Zehe, 2010) revealed that this approach allowed successful reproduction of tile drain event discharge recorded during an irrigation experiment at a tile drained field site. However, several "hillslope architectures" that were all consistent with the available extensive data base allowed a good reproduction of tile drain flow response. Our second objective was thus to find out whether this "equifinality" in spatial model setups may be reduced when including bromide tracer data in the model falsification process. We thus simulated transport of bromide and Isoproturon (IPU) for the 13 spatial model setups, which performed best with respect to reproduce tile drain event discharge, without any further calibration. All model setups allowed a very good prediction of the temporal dynamics of cumulated bromide leaching into the tile drain, while only four of them matched the accumulated water balance and accumulated bromide loss into the tile drain. The number of behavioural model architectures could thus be reduced to four. One of those setups was used for simulating transport of IPU, using different parameter combinations to characterise adsorption according to the Footprint data base. Simulations could, however, only reproduce the observed leaching behaviour, when we allowed for retardation coefficients that were very close to one.

Irradiation as a disinfestation method - update on methyl bromide phase out, regulatory action and emerging opportunities

International Nuclear Information System (INIS)

Marcotte, Michelle

1998-01-01

Methyl bromide (MeBr), is the most widely used agricultural fumigant in the world for the control of pests and plant diseases. It is used to control pests and diseases in food, agricultural and forestry commodities after harvest, before or during storage or transportation and/or at time of import to control quarantine or storage pests. Knowing MeBr will be phased out has spurred a search for alternative treatments and products, and has placed pressure on regulatory authorities to approve alternatives. Some of methyl bromide use could be replaced with irradiation. Methyl bromide is also used for soil and structural fumigation, and although there is some use of irradiation for packaged soil or greenhouse products, in general, these uses can not be replaced by irradiation. Some radiation processing facilities have either seen increased business to disinfest commodities, or have experienced more inquiries for service. There are many other processes and products competing for this market and irradiation will not win its share of the business without an improved regulatory picture, improved marketing to methyl bromide users and improved information to answer questions from commodity sectors. The United Nations Environment Program - Methyl Bromide Technical Options Committee (MBTOC) provides a venue for the publication or information about the use and availability of irradiation as an alternative to methyl bromide. It provides the technical base to the Montreal Protocol contributing to the setting of phase out dates; this committee is actively researching and assessing all alternatives and needs information about irradiation. The author is a member of the MBTOC committee

Crude petroleum-oil biodegradation efficiency of Bacillus subtilis and Pseudomonas aeruginosa strains isolated from a petroleum-oil contaminated soil from North-East India.

Science.gov (United States)

Das, Kishore; Mukherjee, Ashis K

2007-05-01

The efficiency of Bacillus subtilis DM-04 and Pseudomonas aeruginosa M and NM strains isolated from a petroleum contaminated soil sample from North-East India was compared for the biodegradation of crude petroleum-oil hydrocarbons in soil and shake flask study. These bacterial strains could utilize crude petroleum-oil hydrocarbons as sole source of carbon and energy. Bioaugmentation of TPH contaminated microcosm with P. aeruginosa M and NM consortia and B. subtilis strain showed a significant reduction of TPH levels in treated soil as compared to control soil at the end of experiment (120 d). P. aeruginosa strains were more efficient than B. subtilis strain in reducing the TPH content from the medium. The plate count technique indicated expressive growth and biosurfactant production by exogenously seeded bacteria in crude petroleum-oil rich soil. The results showed that B. subtilis DM-04 and P. aeruginosa M and NM strains could be effective for in situ bioremediation.

Mechanism and in vivo evaluation :photodynamic antibacterial chemotherapy of lysine-porphyrin conjugate

Directory of Open Access Journals (Sweden)

Zengping eXu

2016-03-01

Full Text Available We previously reported lysine-porphyrin conjugate 4i, which had potent photosensitive antibacterial effect on clinical isolated Methicillin-resistant Staphylococcus aureus (MRSA, Escherichia coli (E. coli and Pseudomonas aeruginosa (P. aeruginosa bacterial strains. The aim of this paper is to evaluate the mechanism of photodynamic antibacterial chemotherapy of 4i (4i-PACT in vitro and the treatment effect in vivo. Atomic force microscopy (AFM revealed 4i-PACT could effectively destroy bacterial membrane and wall, making the bacterial content leakage, which was confirmed by dual fluorescent staining with acridine orange/ethidium bromide (AO/EB and absorbance at 260 nm, agarose gel electrophoresis indicated 4i-PACT could damage genomic DNA. The results combined AFM and DNA electrophoresis revealed why the bacterial strains had no resistance to 4i-PACT. Wound healing in rat model with mixed bacteria infected wounds showed the efficiency of 4i-PACT was light-dose dependent. These results showed 4i-PACT had promising bactericidal effect both in vitro and in vivo.

Antagonistic interactions are sufficient to explain self-assemblage of bacterial communities in a homogeneous environment: a computational modeling approach

Directory of Open Access Journals (Sweden)

Román eZapién-Campos

2015-05-01

Full Text Available Most of the studies in Ecology have been devoted to analyzing the effects the environment has on individuals, populations, and communities, thus neglecting the effects of biotic interactions on the system dynamics. In the present work we study the structure of bacterial communities in the oligotrophic shallow water system of Churince, Cuatro Cienegas, Mexico. Since the physicochemical conditions of this water system are homogeneous and quite stable in time, it is an excellent candidate to study how biotic factors influence the structure of bacterial communities. In a previous study, the binary antagonistic interactions of 78 bacterial strains, isolated from Churince, were experimentally determined. We employ these data to develop a computer algorithm to simulate growth experiments in a cellular grid representing the pond. Remarkably, in our model, the dynamics of all the simulated bacterial populations is determined solely by antagonistic interactions. Our results indicate that all bacterial strains (even those that are antagonized by many other bacteria survive in the long term, and that the underlying mechanism is the formation of bacterial community patches. Patches corresponding to less antagonistic and highly susceptible strains are consistently isolated from the highly-antagonistic bacterial colonies by patches of neutral strains. These results concur with the observed features of the bacterial community structure previously reported. Finally, we study how our findings depend on factors like initial population size, differential population growth rates, homogeneous population death rates, and enhanced bacterial diffusion.

Bacterial adhesion to unworn and worn silicone hydrogel lenses.

Science.gov (United States)

Vijay, Ajay Kumar; Zhu, Hua; Ozkan, Jerome; Wu, Duojia; Masoudi, Simin; Bandara, Rani; Borazjani, Roya N; Willcox, Mark D P

2012-08-01

The objective of this study was to determine the bacterial adhesion to various silicone hydrogel lens materials and to determine whether lens wear modulated adhesion. Bacterial adhesion (total and viable cells) of Staphylococcus aureus (31, 38, and ATCC 6538) and Pseudomonas aeruginosa (6294, 6206, and GSU-3) to 10 commercially available different unworn and worn silicone hydrogel lenses was measured. Results of adhesion were correlated to polymer and surface properties of contact lenses. S. aureus adhesion to unworn lenses ranged from 2.8 × 10 to 4.4 × 10 colony forming units per lens. The highest adhesion was to lotrafilcon A lenses, and the lowest adhesion was to asmofilcon A lenses. P. aeruginosa adhesion to unworn lenses ranged from 8.9 × 10 to 3.2 × 10 colony forming units per lens. The highest adhesion was to comfilcon A lenses, and the lowest adhesion was to asmofilcon A and balafilcon A lenses. Lens wear altered bacterial adhesion, but the effect was specific to lens and strain type. Adhesion of bacteria, regardless of genera/species or lens wear, was generally correlated with the hydrophobicity of the lens; the less hydrophobic the lens surface, the greater the adhesion. P. aeruginosa adhered in higher numbers to lenses in comparison with S. aureus strains, regardless of the lens type or lens wear. The effect of lens wear was specific to strain and lens. Hydrophobicity of the silicone hydrogel lens surface influenced the adhesion of bacterial cells.

Biodegradability of bacterial surfactants.

Science.gov (United States)

Lima, Tânia M S; Procópio, Lorena C; Brandão, Felipe D; Carvalho, André M X; Tótola, Marcos R; Borges, Arnaldo C

2011-06-01

This work aimed at evaluating the biodegradability of different bacterial surfactants in liquid medium and in soil microcosms. The biodegradability of biosurfactants by pure and mixed bacterial cultures was evaluated through CO(2) evolution. Three bacterial strains, Acinetobacter baumanni LBBMA ES11, Acinetobacter haemolyticus LBBMA 53 and Pseudomonas sp. LBBMA 101B, used the biosurfactants produced by Bacillus sp. LBBMA 111A (mixed lipopeptide), Bacillus subtilis LBBMA 155 (lipopeptide), Flavobacterium sp. LBBMA 168 (mixture of flavolipids), Dietzia Maris LBBMA 191(glycolipid) and Arthrobacter oxydans LBBMA 201(lipopeptide) as carbon sources in minimal medium. The synthetic surfactant sodium dodecyl sulfate (SDS) was also mineralized by these microorganisms, but at a lower rate. CO(2) emitted by a mixed bacterial culture in soil microcosms with biosurfactants was higher than in the microcosm containing SDS. Biosurfactant mineralization in soil was confirmed by the increase in surface tension of the soil aqueous extracts after incubation with the mixed bacterial culture. It can be concluded that, in terms of biodegradability and environmental security, these compounds are more suitable for applications in remediation technologies in comparison to synthetic surfactants. However, more information is needed on structure of biosurfactants, their interaction with soil and contaminants and scale up and cost for biosurfactant production.

Elimination of nonspecific radioactivity from [76Br]bromide in PET study with [76Br]bromodeoxyuridine

International Nuclear Information System (INIS)

Li Lu; Bergstroem, Mats; Fasth, Karl-Johan; Wu Feng; Eriksson, Barbro; Laangstroem, Bengt

1999-01-01

[ 76 Br]Bromodeoxyuridine ([ 76 Br]BrdU) might allow a determination of proliferation in vivo using positron emission tomography (PET), but only with consideration of organ nonspecific radioactivity constituted by [ 76 Br]bromide. A first study assessed the potential of diuretics to eliminate [ 76 Br]bromide. [ 76 Br]Bromide was injected in the vein of rats and different diuretic combinations were given. Urine was collected and radioactivity measured. Torasemide plus sodium chloride gave better 76 Br elimination than the other diuretics. In a second experiment, rats were given [ 76 Br]BrdU. After the radioactivity injection, the rats of the treatment group were given torasemide plus NaCl. At 44 h after the radioactivity injection, the radioactivity concentration and the fraction incorporated into DNA were measured in different organs. Using diuretics, the elimination of [ 76 Br]bromide was increased. The radioactivity decreased 30-50% in most of the organs but the highest radioactivity uptake was found in the organs with more active DNA synthesis. This method may facilitate the use of [ 76 Br]BrdU as a tracer for DNA synthesis using PET

Biotreatment of industrial wastewater by selected algal-bacterial consortia

Energy Technology Data Exchange (ETDEWEB)

Safonova, E.; Kvitko, K.V. [St. Petersburg State University, Biological Institute, Oranienbaum Chaussee 2, Old Peterhof, 198504 St. Petersburg (Russian Federation); Iankevitch, M.I.; Surgko, L.F.; Afti, I.A. [Ecoprom Ltd., Gruzovoi Proezd 13, Obukhovo, 192289 St. Petersburg (Russian Federation); Reisser, W. [Universitaet Leipzig, Botanisches Institut, Johannisallee 21-23, D-04103 Leipzig (Germany)

2004-08-01

A new approach for remediation processes in highly polluted environments is presented. The efficiency of algal-bacterial associations for the remediation of industrial wastewater of a pond in Samara, Russia, was investigated. After screening of algae and bacteria for the resistance to the wastewater the following strains were selected: the algal strains Chlorella sp. ES-13, Chlorella sp. ES-30, Scenedesmus obliquus ES-55, several Stichococcus strains (ES-19, ES-85, ES-86, ES-87, ES-88), and Phormidium sp. ES-90 and the bacterial strains Rhodococcus sp. Ac-1267, Kibdelosporangium aridum 754 as well as two unidentified bacterial strains (St-1, St-2) isolated from the collector pond. All the strains listed above were immobilized onto various solid carriers (capron fibers for algae; ceramics, capron and wood for bacteria) and used for biotreatment in a pilot installation. The results showed that the selected algae and bacteria formed stable consortia during the degradation of the waste, which was demonstrated for the first time for the green alga Stichococcus. Stichococcus and Phormidium cells attached to capron fibers with the help of slime and formed a matrix. This matrix fixed the bacteria and eukaryotic algae and prevented them from being washed off. A significant decrease in the content of the pollutants was observed: phenols were removed up to 85 %, anionic surface active substances (anionic SAS) up to 73 %, oil spills up to 96 %, copper up to 62 %, nickel up to 62 %, zinc up to 90 %, manganese up to 70 %, and iron up to 64 %. The reduction of the biological oxygen demand (BOD{sub 25}) and the chemical oxygen demand COD amounted to 97 % and 51 %, respectively. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

Xylose utilization in recombinant zymomonas

Science.gov (United States)

Caimi, Perry G; McCole, Laura; Tao, Luan; Tomb, Jean-Francois; Viitanen, Paul V

2014-03-25

Xylose-utilizing Zymomonas strains studied were found to accumulate ribulose when grown in xylose-containing media. Engineering these strains to increase ribose-5-phosphate isomerase activity led to reduced ribulose accumulation, improved growth, improved xylose utilization, and increased ethanol production.

2,6-Bis(oxazolinyl)phenylnickel(II) Bromide and 2,6-Bis(ketimine)phenylnickel(II) Bromide: Synthesis, Structural Features, and Redox Properties

NARCIS (Netherlands)

Stol, M.; Snelders, D.J.M.|info:eu-repo/dai/nl/304836257; Godbole, M.D.; Havenith, R.W.A.|info:eu-repo/dai/nl/205279546; Haddleton, D.M.; Clarkson, G.; Lutz, M.|info:eu-repo/dai/nl/304828971; Spek, A.L.|info:eu-repo/dai/nl/156517566; van Klink, G.P.M.|info:eu-repo/dai/nl/170637964; van Koten, G.|info:eu-repo/dai/nl/073839191

2007-01-01

2,6-Bis(oxazolinyl)phenylnickel bromide complexes [NiBr(R,R'-Phebox)] (2) were synthesized via two synthetic routes (A and B). In route A, selective bis-ortho lithiation of [R,R'-PheboxBr], followed by a transmetalation reaction with [NiBr2(PEt3)2], yielded not only complexes 2 with an

Aluminum electroplating on steel from a fused bromide electrolyte

Energy Technology Data Exchange (ETDEWEB)

Prabhat K. Tripathy; Laura A. Wurth; Eric J. Dufek; Toni Y. Gutknecht; Natalie J. Gese; Paula Hahn; Steven M. Frank; Guy L. Frederickson; J. Stephen Herring

2014-08-01

A quaternary bromide bath (LiBr–KBr–CsBr–AlBr3) was used to electro-coat aluminum on steel substrates. The electrolytewas prepared by the addition of AlBr3 into the eutectic LiBr–KBr–CsBr melt. A smooth, thick, adherent and shiny aluminum coating could be obtained with 80 wt.% AlBr3 in the ternary melt. The SEM photographs of the coated surfaces suggest the formation of thick and dense coatings with good aluminum coverage. Both salt immersion and open circuit potential measurement suggested that the coatings did display a good corrosionresistance behavior. Annealing of the coated surfaces, prior to corrosion tests, suggested the robustness of the metallic aluminum coating in preventing the corrosion of the steel surfaces. Studies also indicated that the quaternary bromide plating bath can potentially provide a better aluminumcoating on both ferrous and non-ferrous metals, including complex surfaces/geometries.

Aluminium Electroplating on Steel from a Fused Bromide Electrolyte

Energy Technology Data Exchange (ETDEWEB)

Prabhat Tripathy; Laura Wurth; Eric Dufek; Toni Y. Gutknecht; Natalie Gese; Paula Hahn; Steven Frank; Guy Fredrickson; J Stephen Herring

2014-08-01

A quaternary bromide bath (LiBr-KBr-CsBr-AlBr3) was used to electro-coat aluminium on steel substrates. The electrolyte was prepared by the addition of AlBr3 into the eutectic LiBr-KBr-CsBr melt. A smooth, thick, adherent and shiny aluminium coating could be obtained with 80 wt.% AlBr3 in the ternary melt. The SEM photographs of the coated surfaces suggest the formation of thick and dense coatings with good aluminium coverage. Both salt immersion and open circuit potential measurement suggest that the coatings did display good corrosion-resistance behavior. Annealing of the coated surfaces, prior to corrosion tests, suggested the robustness of the metallic aluminium coating in preventing the corrosion of the steel surfaces. Studies also indicated that the quaternary bromide plating bath can potentially provide a better aluminium coating on both ferrous and non-ferrous metals, including complex surfaces/geometries.

Bacterial adhesion to conventional hydrogel and new silicone-hydrogel contact lens materials.

Science.gov (United States)

Kodjikian, Laurent; Casoli-Bergeron, Emmanuelle; Malet, Florence; Janin-Manificat, Hélène; Freney, Jean; Burillon, Carole; Colin, Joseph; Steghens, Jean-Paul

2008-02-01

As bacterial adhesion to contact lenses may contribute to the pathogenesis of keratitis, the aim of our study was to investigate in vitro adhesion of clinically relevant bacteria to conventional hydrogel (standard HEMA) and silicone-hydrogel contact lenses using a bioluminescent ATP assay. Four types of unworn contact lenses (Etafilcon A, Galyfilcon A, Balafilcon A, Lotrafilcon B) were incubated with Staphylococcus epidermidis (two different strains) and Pseudomonas aeruginosa suspended in phosphate buffered saline (PBS). Lenses were placed with the posterior surface facing up and were incubated in the bacterial suspension for 4 hours at 37 degrees C. Bacterial binding was then measured and studied by bioluminescent ATP assay. Six replicate experiments were performed for each lens and strain. Adhesion of all species of bacteria to standard HEMA contact lenses (Etafilcon A) was found to be significantly lower than that of three types of silicone-hydrogel contact lenses, whereas Lotrafilcon B material showed the highest level of bacterial binding. Differences between species in the overall level of adhesion to the different types of contact lenses were observed. Adhesion of P. aeruginosa was typically at least 20 times greater than that observed with both S. epidermidis strains. Conventional hydrogel contact lenses exhibit significantly lower bacterial adhesion in vitro than silicone-hydrogel ones. This could be due to the greater hydrophobicity but also to the higher oxygen transmissibility of silicone-hydrogel lenses.

Use of atomic force microscopy and transmission electron microscopy for correlative studies of bacterial capsules.

Science.gov (United States)

Stukalov, Oleg; Korenevsky, Anton; Beveridge, Terry J; Dutcher, John R

2008-09-01

Bacteria can possess an outermost assembly of polysaccharide molecules, a capsule, which is attached to their cell wall. We have used two complementary, high-resolution microscopy techniques, atomic force microscopy (AFM) and transmission electron microscopy (TEM), to study bacterial capsules of four different gram-negative bacterial strains: Escherichia coli K30, Pseudomonas aeruginosa FRD1, Shewanella oneidensis MR-4, and Geobacter sulfurreducens PCA. TEM analysis of bacterial cells using different preparative techniques (whole-cell mounts, conventional embeddings, and freeze-substitution) revealed capsules for some but not all of the strains. In contrast, the use of AFM allowed the unambiguous identification of the presence of capsules on all strains used in the present study, including those that were shown by TEM to be not encapsulated. In addition, the use of AFM phase imaging allowed the visualization of the bacterial cell within the capsule, with a depth sensitivity that decreased with increasing tapping frequency.

Activity of aminotransferases in organs of rats during hypoxia of enclosed space of the action of thiamine bromide

Directory of Open Access Journals (Sweden)

Сніжана Сергіївна Чернадчук

2015-05-01

Full Text Available It is studied an aminotransferase activity during injection of thiamin bromide in rat tissues in normal and hypoxic enclosed space. After injection of thiamine bromide we have set reduction of AST and ALT activity, relative to control, except by the brain tissue, where there was an increase of investigated indicators. The decrease of activity of the investigated elements is occurred in animals which before hypoxia were injection of thiamine bromide

Utility of the serum C-reactive protein for detection of occult bacterial infection in children.

Science.gov (United States)

Isaacman, Daniel J; Burke, Bonnie L

2002-09-01

To assess the utility of serum C-reactive protein (CRP) as a screen for occult bacterial infection in children. Febrile children ages 3 to 36 months who visited an urban children's hospital emergency department and received a complete blood cell count and blood culture as part of their evaluation were prospectively enrolled from February 2, 2000, through May 30, 2001. Informed consent was obtained for the withdrawal of an additional 1-mL aliquot of blood for use in CRP evaluation. Logistic regression and receiver operator characteristic (ROC) curves were modeled for each predictor to identify optimal test values, and were compared using likelihood ratio tests. Two hundred fifty-six patients were included in the analysis, with a median age of 15.3 months (range, 3.1-35.2 months) and median temperature at triage 40.0 degrees C (range, 39.0 degrees C-41.3 degrees C). Twenty-nine (11.3%) cases of occult bacterial infection (OBI) were identified, including 17 cases of pneumonia, 9 cases of urinary tract infection, and 3 cases of bacteremia. The median white blood cell count in this data set was 12.9 x 10(3)/ micro L [corrected] (range, 3.6-39.1 x10(3)/ micro L) [corrected], the median absolute neutrophil count (ANC) was 7.12 x 10(3)/L [corrected] (range, 0.56-28.16 x10(3)/L) [corrected], and the median CRP level was 1.7 mg/dL (range, 0.2-43.3 mg/dL). The optimal cut-off point for CRP in this data set (4.4 mg/dL) achieved a sensitivity of 63% and a specificity of 81% for detection of OBI in this population. Comparing models using cut-off values from individual laboratory predictors (ANC, white blood cell count, and CRP) that maximized sensitivity and specificity revealed that a model using an ANC of 10.6 x10(3)/L [corrected] (sensitivity, 69%; specificity, 79%) was the best predictive model. Adding CRP to the model insignificantly increased sensitivity to 79%, while significantly decreasing specificity to 50%. Active monitoring of emergency department blood cultures

Bacterial genome engineering and synthetic biology: combating pathogens.

Science.gov (United States)

Krishnamurthy, Malathy; Moore, Richard T; Rajamani, Sathish; Panchal, Rekha G

2016-11-04

The emergence and prevalence of multidrug resistant (MDR) pathogenic bacteria poses a serious threat to human and animal health globally. Nosocomial infections and common ailments such as pneumonia, wound, urinary tract, and bloodstream infections are becoming more challenging to treat due to the rapid spread of MDR pathogenic bacteria. According to recent reports by the World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC), there is an unprecedented increase in the occurrence of MDR infections worldwide. The rise in these infections has generated an economic strain worldwide, prompting the WHO to endorse a global action plan to improve awareness and understanding of antimicrobial resistance. This health crisis necessitates an immediate action to target the underlying mechanisms of drug resistance in bacteria. The advent of new bacterial genome engineering and synthetic biology (SB) tools is providing promising diagnostic and treatment plans to monitor and treat widespread recalcitrant bacterial infections. Key advances in genetic engineering approaches can successfully aid in targeting and editing pathogenic bacterial genomes for understanding and mitigating drug resistance mechanisms. In this review, we discuss the application of specific genome engineering and SB methods such as recombineering, clustered regularly interspaced short palindromic repeats (CRISPR), and bacterial cell-cell signaling mechanisms for pathogen targeting. The utility of these tools in developing antibacterial strategies such as novel antibiotic production, phage therapy, diagnostics and vaccine production to name a few, are also highlighted. The prevalent use of antibiotics and the spread of MDR bacteria raise the prospect of a post-antibiotic era, which underscores the need for developing novel therapeutics to target MDR pathogens. The development of enabling SB technologies offers promising solutions to deliver safe and effective antibacterial therapies.

Bromide Sources and Loads in Swiss Surface Waters and Their Relevance for Bromate Formation during Wastewater Ozonation.

Science.gov (United States)

Soltermann, Fabian; Abegglen, Christian; Götz, Christian; von Gunten, Urs

2016-09-20

Bromide measurements and mass balances in the catchments of major Swiss rivers revealed that chemical industry and municipal waste incinerators are the most important bromide sources and account for ∼50% and ∼20%, respectively, of the ∼2000 tons of bromide discharged in the Rhine river in 2014 in Switzerland. About 100 wastewater treatment plants (WWTPs) will upgrade their treatment for micropollutant abatement in the future to comply with Swiss regulations. An upgrade with ozonation may lead to unintended bromate formation in bromide-containing wastewaters. Measured bromide concentrations were industry). Wastewater ozonation formed little bromate at specific ozone doses of ≤0.4 mg O3/mg DOC, while the bromate yields were almost linearly correlated to the specific ozone dose for higher ozone doses. Molar bromate yields for typical specific ozone doses in wastewater treatment (0.4-0.6 mg O3/mg DOC) are ≤3%. In a modeled extreme scenario (in which all upgraded WWTPs release 10 μg L(-1) of bromate), bromate concentrations increased by major Swiss rivers and by several micrograms per liter in receiving water bodies with a high fraction of municipal wastewater.

Modeling bacterial contamination of fuel ethanol fermentation.

Science.gov (United States)

Bischoff, Kenneth M; Liu, Siqing; Leathers, Timothy D; Worthington, Ronald E; Rich, Joseph O

2009-05-01

The emergence of antibiotic-resistant bacteria may limit the effectiveness of antibiotics to treat bacterial contamination in fuel ethanol plants, and therefore, new antibacterial intervention methods and tools to test their application are needed. Using shake-flask cultures of Saccharomyces cerevisiae grown on saccharified corn mash and strains of lactic acid bacteria isolated from a dry-grind ethanol facility, a simple model to simulate bacterial contamination and infection was developed. Challenging the model with 10(8) CFU/mL Lactobacillus fermentum decreased ethanol yield by 27% and increased residual glucose from 6.2 to 45.5 g/L. The magnitude of the effect was proportional to the initial bacterial load, with 10(5) CFU/mL L. fermentum still producing an 8% decrease in ethanol and a 3.2-fold increase in residual glucose. Infection was also dependent on the bacterial species used to challenge the fermentation, as neither L. delbrueckii ATCC 4797 nor L. amylovorus 0315-7B produced a significant decrease in ethanol when inoculated at a density of 10(8) CFU/mL. In the shake-flask model, treatment with 2 microg/mL virginiamycin mitigated the infection when challenged with a susceptible strain of L. fermentum (MIC for virginiamycin model may find application in developing new antibacterial agents and management practices for use in controlling contamination in the fuel ethanol industry. Copyright 2008 Wiley Periodicals, Inc.

[Physiological and biochemical characteristics and capacity for polyhydroxyalkanoates synthesis in a glucose-utilizing strain of hydrogen-oxidizing bacteria, Ralstonia eutropha B8562].

Science.gov (United States)

Volova, T G; Kozhevnikov, I V; Dolgopolova, Iu B; Trusova, M Iu; Kalacheva, G S; Aref'eva, Iu V

2005-01-01

The physiological, biochemical, genetic, and cultural characteristics of the glucose-utilizing mutant strain Ralstonia eutropha B8562 were investigated in comparison with the parent strain R. eutropha B5786. The morphological, cultural, and biochemical characteristics of strain R. eutropha B8562 were similar to those of strain R. eutropha B5786. Genetic analysis revealed differences between the 16S rRNA gene sequences of these strains. The growth characteristics of the mutant using glucose as the sole carbon and energy source were comparable with those of the parent strain grown on fructose. Strain B8562 was characterized by high yields of polyhydroxyalkanoate (PHA) from different carbon sources (CO2, fructose, and glucose). In batch culture with glucose under nitrogen limitation, PHA accumulation reached 90% of dry weight. In PHA, beta-hydroxybutyrate was predominant (over 99 mol %); beta-hydroxyvalerate (0.25-0.72 mol %) and beta-hydroxyhexanoate (0.008-1.5 mol %) were present as minor components. The strain has prospects as a PHA producer on glucose-containing media.

Thermal decomposition mechanism of 1-ethyl-3-methylimidazolium bromide ionic liquid.

Science.gov (United States)

Chambreau, Steven D; Boatz, Jerry A; Vaghjiani, Ghanshyam L; Koh, Christine; Kostko, Oleg; Golan, Amir; Leone, Stephen R

2012-06-21

In order to better understand the volatilization process for ionic liquids, the vapor evolved from heating the ionic liquid 1-ethyl-3-methylimidazolium bromide (EMIM(+)Br(-)) was analyzed via tunable vacuum ultraviolet photoionization time-of-flight mass spectrometry (VUV-PI-TOFMS) and thermogravimetric analysis mass spectrometry (TGA-MS). For this ionic liquid, the experimental results indicate that vaporization takes place via the evolution of alkyl bromides and alkylimidazoles, presumably through alkyl abstraction via an S(N)2 type mechanism, and that vaporization of intact ion pairs or the formation of carbenes is negligible. Activation enthalpies for the formation of the methyl and ethyl bromides were evaluated experimentally, ΔH(‡)(CH(3)Br) = 116.1 ± 6.6 kJ/mol and ΔH(‡)(CH(3)CH(2)Br) = 122.9 ± 7.2 kJ/mol, and the results are found to be in agreement with calculated values for the S(N)2 reactions. Comparisons of product photoionization efficiency (PIE) curves with literature data are in good agreement, and ab initio thermodynamics calculations are presented as further evidence for the proposed thermal decomposition mechanism. Estimates for the enthalpy of vaporization of EMIM(+)Br(-) and, by comparison, 1-butyl-3-methylimidazolium bromide (BMIM(+)Br(-)) from molecular dynamics calculations and their gas phase enthalpies of formation obtained by G4 calculations yield estimates for the ionic liquids' enthalpies of formation in the liquid phase: ΔH(vap)(298 K) (EMIM(+)Br(-)) = 168 ± 20 kJ/mol, ΔH(f, gas)(298 K) (EMIM(+)Br(-)) = 38.4 ± 10 kJ/mol, ΔH(f, liq)(298 K) (EMIM(+)Br(-)) = -130 ± 22 kJ/mol, ΔH(f, gas)(298 K) (BMIM(+)Br(-)) = -5.6 ± 10 kJ/mol, and ΔH(f, liq)(298 K) (BMIM(+)Br(-)) = -180 ± 20 kJ/mol.

Expression of Heterologous Cellulases in Thermotoga sp. Strain RQ2

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Hui Xu

2015-01-01

Full Text Available The ability of Thermotoga spp. to degrade cellulose is limited due to a lack of exoglucanases. To address this deficiency, cellulase genes Csac_1076 (celA and Csac_1078 (celB from Caldicellulosiruptor saccharolyticus were cloned into T. sp. strain RQ2 for heterologous overexpression. Coding regions of Csac_1076 and Csac_1078 were fused to the signal peptide of TM1840 (amyA and TM0070 (xynB, resulting in three chimeric enzymes, namely, TM1840-Csac_1078, TM0070-Csac_1078, and TM0070-Csac_1076, which were carried by Thermotoga-E. coli shuttle vectors pHX02, pHX04, and pHX07, respectively. All three recombinant enzymes were successfully expressed in E. coli DH5α and T. sp. strain RQ2, rendering the hosts with increased endo- and/or exoglucanase activities. In E. coli, the recombinant enzymes were mainly bound to the bacterial cells, whereas in T. sp. strain RQ2, about half of the enzyme activities were observed in the culture supernatants. However, the cellulase activities were lost in T. sp. strain RQ2 after three consecutive transfers. Nevertheless, this is the first time heterologous genes bigger than 1 kb (up to 5.3 kb in this study have ever been expressed in Thermotoga, demonstrating the feasibility of using engineered Thermotoga spp. for efficient cellulose utilization.

Degradation of paracetamol by pure bacterial cultures and their microbial consortium.

Science.gov (United States)

Zhang, Lili; Hu, Jun; Zhu, Runye; Zhou, Qingwei; Chen, Jianmeng

2013-04-01

Three bacterial strains utilizing paracetamol as the sole carbon, nitrogen, and energy source were isolated from a paracetamol-degrading aerobic aggregate, and assigned to species of the genera Stenotrophomonas and Pseudomonas. The Stenotrophomonas species have not included any known paracetamol degraders until now. In batch cultures, the organisms f1, f2, and fg-2 could perform complete degradation of paracetamol at concentrations of 400, 2,500, and 2,000 mg/L or below, respectively. A combination of three microbial strains resulted in significantly improved degradation and mineralization of paracetamol. The co-culture was able to use paracetamol up to concentrations of 4,000 mg/L, and mineralized 87.1 % of the added paracetamol at the initial of 2,000 mg/L. Two key metabolites of the biodegradation pathway of paracetamol, 4-aminophenol, and hydroquinone were detected. Paracetamol was degraded predominantly via 4-aminophenol to hydroquinone with subsequent ring fission, suggesting new pathways for paracetamol-degrading bacteria. The degradation of paracetamol could thus be performed by the single isolates, but is stimulated by a synergistic interaction of the three-member consortium, suggesting a possible complementary interaction among the various isolates. The exact roles of each of the strains in the consortium need to be further elucidated.

78 FR 36507 - Notice of Availability of a Treatment Evaluation Document; Methyl Bromide Fumigation of Blueberries

Science.gov (United States)

2013-06-18

... treatment schedule for blueberries at a temperature of 60[emsp14][deg]F at a dosage rate of 2 lbs gas/1,000...] Notice of Availability of a Treatment Evaluation Document; Methyl Bromide Fumigation of Blueberries... and Quarantine Treatment Manual an additional treatment schedule for methyl bromide fumigation of...

CRISPR technologies for bacterial systems: Current achievements and future directions.

Science.gov (United States)

Choi, Kyeong Rok; Lee, Sang Yup

2016-11-15

Throughout the decades of its history, the advances in bacteria-based bio-industries have coincided with great leaps in strain engineering technologies. Recently unveiled clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated proteins (Cas) systems are now revolutionizing biotechnology as well as biology. Diverse technologies have been derived from CRISPR/Cas systems in bacteria, yet the applications unfortunately have not been actively employed in bacteria as extensively as in eukaryotic organisms. A recent trend of engineering less explored strains in industrial microbiology-metabolic engineering, synthetic biology, and other related disciplines-is demanding facile yet robust tools, and various CRISPR technologies have potential to cater to the demands. Here, we briefly review the science in CRISPR/Cas systems and the milestone inventions that enabled numerous CRISPR technologies. Next, we describe CRISPR/Cas-derived technologies for bacterial strain development, including genome editing and gene expression regulation applications. Then, other CRISPR technologies possessing great potential for industrial applications are described, including typing and tracking of bacterial strains, virome identification, vaccination of bacteria, and advanced antimicrobial approaches. For each application, we note our suggestions for additional improvements as well. In the same context, replication of CRISPR/Cas-based chromosome imaging technologies developed originally in eukaryotic systems is introduced with its potential impact on studying bacterial chromosomal dynamics. Also, the current patent status of CRISPR technologies is reviewed. Finally, we provide some insights to the future of CRISPR technologies for bacterial systems by proposing complementary techniques to be developed for the use of CRISPR technologies in even wider range of applications. Copyright © 2016. Published by Elsevier Inc.

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

Energy Technology Data Exchange (ETDEWEB)

Karczewska, H

1962-01-01

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

A novel explicit approach to model bromide and pesticide transport in connected soil structures

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J. Klaus

2011-07-01

Full Text Available The present study tests whether an explicit treatment of worm burrows and tile drains as connected structures is feasible for simulating water flow, bromide and pesticide transport in structured heterogeneous soils at hillslope scale. The essence is to represent worm burrows as morphologically connected paths of low flow resistance in a hillslope model. A recent Monte Carlo study (Klaus and Zehe, 2010, Hydrological Processes, 24, p. 1595–1609 revealed that this approach allowed successful reproduction of tile drain event discharge recorded during an irrigation experiment at a tile drained field site. However, several "hillslope architectures" that were all consistent with the available extensive data base allowed a good reproduction of tile drain flow response. Our second objective was thus to find out whether this "equifinality" in spatial model setups may be reduced when including bromide tracer data in the model falsification process. We thus simulated transport of bromide for the 13 spatial model setups that performed best with respect to reproduce tile drain event discharge, without any further calibration. All model setups allowed a very good prediction of the temporal dynamics of cumulated bromide leaching into the tile drain, while only four of them matched the accumulated water balance and accumulated bromide loss into the tile drain. The number of behavioural model architectures could thus be reduced to four. One of those setups was used for simulating transport of Isoproturon, using different parameter combinations to characterise adsorption according to the Footprint data base. Simulations could, however, only reproduce the observed leaching behaviour, when we allowed for retardation coefficients that were very close to one.

A novel explicit approach to model bromide and pesticide transport in connected soil structures

Science.gov (United States)

Klaus, J.; Zehe, E.

2011-07-01

The present study tests whether an explicit treatment of worm burrows and tile drains as connected structures is feasible for simulating water flow, bromide and pesticide transport in structured heterogeneous soils at hillslope scale. The essence is to represent worm burrows as morphologically connected paths of low flow resistance in a hillslope model. A recent Monte Carlo study (Klaus and Zehe, 2010, Hydrological Processes, 24, p. 1595-1609) revealed that this approach allowed successful reproduction of tile drain event discharge recorded during an irrigation experiment at a tile drained field site. However, several "hillslope architectures" that were all consistent with the available extensive data base allowed a good reproduction of tile drain flow response. Our second objective was thus to find out whether this "equifinality" in spatial model setups may be reduced when including bromide tracer data in the model falsification process. We thus simulated transport of bromide for the 13 spatial model setups that performed best with respect to reproduce tile drain event discharge, without any further calibration. All model setups allowed a very good prediction of the temporal dynamics of cumulated bromide leaching into the tile drain, while only four of them matched the accumulated water balance and accumulated bromide loss into the tile drain. The number of behavioural model architectures could thus be reduced to four. One of those setups was used for simulating transport of Isoproturon, using different parameter combinations to characterise adsorption according to the Footprint data base. Simulations could, however, only reproduce the observed leaching behaviour, when we allowed for retardation coefficients that were very close to one.

A simple and novel modification of comet assay for determination of bacteriophage mediated bacterial cell lysis.

Science.gov (United States)

Khairnar, Krishna; Sanmukh, Swapnil; Chandekar, Rajshree; Paunikar, Waman

2014-07-01

The comet assay is the widely used method for in vitro toxicity testing which is also an alternative to the use of animal models for in vivo testing. Since, its inception in 1984 by Ostling and Johansson, it is being modified frequently for a wide range of application. In spite of its wide applicability, unfortunately there is no report of its application in bacteriophages research. In this study, a novel application of comet assay for the detection of bacteriophage mediated bacterial cell lysis was described. The conventional methods in bacteriophage research for studying bacterial lysis by bacteriophages are plaque assay method. It is time consuming, laborious and costly. The lytic activity of bacteriophage devours the bacterial cell which results in the release of bacterial genomic material that gets detected by ethidium bromide staining method by the comet assay protocol. The objective of this study was to compare efficacy of comet assay with different assay used to study phage mediated bacterial lysis. The assay was performed on culture isolates (N=80 studies), modified comet assay appear to have relatively higher sensitivity and specificity than other assay. The results of the study showed that the application of comet assay can be an economical, time saving and less laborious alternative to conventional plaque assay for the detection of bacteriophage mediated bacterial cell lysis. Copyright © 2014 Elsevier B.V. All rights reserved.

Patterning bacterial communities on epithelial cells.

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Mohammed Dwidar

Full Text Available Micropatterning of bacteria using aqueous two phase system (ATPS enables the localized culture and formation of physically separated bacterial communities on human epithelial cell sheets. This method was used to compare the effects of Escherichia coli strain MG1655 and an isogenic invasive counterpart that expresses the invasin (inv gene from Yersinia pseudotuberculosis on the underlying epithelial cell layer. Large portions of the cell layer beneath the invasive strain were killed or detached while the non-invasive E. coli had no apparent effect on the epithelial cell layer over a 24 h observation period. In addition, simultaneous testing of the localized effects of three different bacterial species; E. coli MG1655, Shigella boydii KACC 10792 and Pseudomonas sp DSM 50906 on an epithelial cell layer is also demonstrated. The paper further shows the ability to use a bacterial predator, Bdellovibriobacteriovorus HD 100, to selectively remove the E. coli, S. boydii and P. sp communities from this bacteria-patterned epithelial cell layer. Importantly, predation and removal of the P. Sp was critical for maintaining viability of the underlying epithelial cells. Although this paper focuses on a few specific cell types, the technique should be broadly applicable to understand a variety of bacteria-epithelial cell interactions.

Methylnaltrexone bromide methanol monosolvate

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Xinbo Zhou

2012-03-01

Full Text Available In the title compound [systematic name: (4R,4aS,7aR,12bS-3-cyclopropylmethyl-4a,9-hydroxy-7-oxo-2,3,4,4a,5,6,7,7a-octahydro-1H-4,12-methanobenzofuro[3,2-e]isoquinolin-3-ium bromide methanol monosolvate], C21H26NO4+·Br−·CH3OH, two of the three six-membered rings adopt chair conformations while the third, which contains a C=C double bond, adopts an approximate half-boat conformation. The 2,3-dihydrofuran ring adopts an envelope conformation. In the crystal, the components are linked by O—H...O and O—H...Br hydrogen bonds. The absolute stereochemistry was inferred from one of the starting materials.

Bacterial adherence on UHMWPE doped with Vitamin E: an in vitro study

International Nuclear Information System (INIS)

Molina-Manso D; Gomez-Barrena E; Esteban J; Adames H; Martinez M J; Cordero J; Fernandez-Roblas R; Puertolas J A

2010-01-01

Biomaterials may improve its capacity to resist bacterial adherence, and subsequent infection through material changes. Our aim was to test the bacterial adherence to vitamin E (VE) doped UHMWPE with S. aureus and S. epidermidis (collection and clinical strains), compared to virgin material. Experimental UHMWPE with 3%, 0.4%, and commercial 0.1% VE concentration (1000 ppm) were tested. The biofilm-developing ability was used as a covariable. The collection strain of S. aureus showed significantly less adherence to the commercial VE UHMWPE (p=0.036) but the clinical strains did not significantly modified its adhesion to UHMWPE in presence of VE. The collection strain of S. epidermidis showed significantly less adherence to experimental UHMWPE with VE, independently of the concentration used (p=0.008). However, only 1 of the 4 clinical strains under study clearly confirmed these results in commercial VE polyethylene. Vitamin E doped UHMWPE affects the adherence of some S. aureus and S. epidermidis strains, independently of the concentration in use, but the results showed important intraspecies differences.

Bacterial adaptation to the gut environment favors successful colonization: microbial and metabonomic characterization of a simplified microbiota mouse model.

Science.gov (United States)

Rezzonico, Enea; Mestdagh, Renaud; Delley, Michèle; Combremont, Séverine; Dumas, Marc-Emmanuel; Holmes, Elaine; Nicholson, Jeremy; Bibiloni, Rodrigo

2011-01-01

Rodent models harboring a simple yet functional human intestinal microbiota provide a valuable tool to study the relationships between mammals and their bacterial inhabitants. In this study, we aimed to develop a simplified gnotobiotic mouse model containing 10 easy-to-grow bacteria, readily available from culture repositories, and of known genome sequence, that overall reflect the dominant commensal bacterial makeup found in adult human feces. We observed that merely inoculating a mix of fresh bacterial cultures into ex-germ free mice did not guarantee a successful intestinal colonization of the entire bacterial set, as mice inoculated simultaneously with all strains only harbored 3 after 21 d. Therefore, several inoculation procedures were tested and levels of individual strains were quantified using molecular tools. Best results were obtained by inoculating single bacterial strains into individual animals followed by an interval of two weeks before allowing the animals to socialize to exchange their commensal microbes. Through this procedure, animals were colonized with almost the complete bacterial set (9/10). Differences in the intestinal composition were also reflected in the urine and plasma metabolic profiles, where changes in lipids, SCFA, and amino acids were observed. We conclude that adaptation of bacterial strains to the host's gut environment (mono-colonization) may predict a successful establishment of a more complex microbiota in rodents.

The effect of new probiotic strain Lactobacillus plantarum on counts of coliforms, lactobacilli and bacterial enzyme activities in rats exposed to N,N-dimethylhydrazine (chemical carcinogen

Directory of Open Access Journals (Sweden)

Denisa Čokášová

2012-01-01

Full Text Available The aim of the present study was to evaluate the effect of the new probiotic strain Lactobacillus plantarum on chemically induced carcinogenesis in rats. Sprague dowley rats (n = 33 were divided into control and experimental groups and were fed a conventional laboratory diet. In the experimental group, rats were treated with the probiotic at the dose of 1 × 109 CFU (colony-forming units/ml. Two weeks after the beginning of the trial, N,N-dimethylhydrazine (chemical carcinogen injections were applied s.c. at the dose of 21 mg/kg b.w., 5 × weekly. At the end of the 8-month experimental period, faeces samples were taken from the rats and used for laboratory analysis. The counts of lactobacilli and coliforms and bacterial enzyme activity were determined. The probiotic strain L. plantarum as single species or in combination with oil (Lini oleum virginale decreased the count of total coliforms and increased lactobacilli in faeces of rats. Application of probiotic microorganisms significantly (P < 0.05 decreased the activities of bacterial enzymes (β-galactosidase and β-glucuronidase compared to the control group rats. The results of this study indicate that probiotic microorganisms could exert a preventive effect on colon carcinogenesis induced by N,N-dimethylhydrazine.

Insights from the Genome Sequence of Acidovorax citrulli M6, a Group I Strain of the Causal Agent of Bacterial Fruit Blotch of Cucurbits.

Science.gov (United States)

Eckshtain-Levi, Noam; Shkedy, Dafna; Gershovits, Michael; Da Silva, Gustavo M; Tamir-Ariel, Dafna; Walcott, Ron; Pupko, Tal; Burdman, Saul

2016-01-01

Acidovorax citrulli is a seedborne bacterium that causes bacterial fruit blotch of cucurbit plants including watermelon and melon. A. citrulli strains can be divided into two major groups based on DNA fingerprint analyses and biochemical properties. Group I strains have been generally isolated from non-watermelon cucurbits, while group II strains are closely associated with watermelon. In the present study, we report the genome sequence of M6, a group I model A. citrulli strain, isolated from melon. We used comparative genome analysis to investigate differences between the genome of strain M6 and the genome of the group II model strain AAC00-1. The draft genome sequence of A. citrulli M6 harbors 139 contigs, with an overall approximate size of 4.85 Mb. The genome of M6 is ∼500 Kb shorter than that of strain AAC00-1. Comparative analysis revealed that this size difference is mainly explained by eight fragments, ranging from ∼35-120 Kb and distributed throughout the AAC00-1 genome, which are absent in the M6 genome. In agreement with this finding, while AAC00-1 was found to possess 532 open reading frames (ORFs) that are absent in strain M6, only 123 ORFs in M6 were absent in AAC00-1. Most of these M6 ORFs are hypothetical proteins and most of them were also detected in two group I strains that were recently sequenced, tw6 and pslb65. Further analyses by PCR assays and coverage analyses with other A. citrulli strains support the notion that some of these fragments or significant portions of them are discriminative between groups I and II strains of A. citrulli. Moreover, GC content, effective number of codon values and cluster of orthologs' analyses indicate that these fragments were introduced into group II strains by horizontal gene transfer events. Our study reports the genome sequence of a model group I strain of A. citrulli, one of the most important pathogens of cucurbits. It also provides the first comprehensive comparison at the genomic level between the

Draft genome sequences of eight bacteria isolated from the indoor environment: Staphylococcus capitis strain H36, S. capitis strain H65, S. cohnii strain H62, S. hominis strain H69, Microbacterium sp. strain H83, Mycobacterium iranicum strain H39, Plantibacter sp. strain H53, and Pseudomonas oryzihabitans strain H72

OpenAIRE

Lymperopoulou, Despoina S.; Coil, David A.; Schichnes, Denise; Lindow, Steven E.; Jospin, Guillaume; Eisen, Jonathan A.; Adams, Rachel I.

2017-01-01

We report here the draft genome sequences of eight bacterial strains of the genera Staphylococcus, Microbacterium, Mycobacterium, Plantibacter, and Pseudomonas. These isolates were obtained from aerosol sampling of bathrooms of five residences in the San Francisco Bay area. Taxonomic classifications as well as the genome sequence and gene annotation of the isolates are described. As part of the ?Built Environment Reference Genome? project, these isolates and associated genome data provide val...

Comparative Genomics Analysis and Phenotypic Characterization of Shewanella putrefaciens W3-18-1: Anaerobic Respiration, Bacterial Microcompartments, and Lateral Flagella

International Nuclear Information System (INIS)

Qiu, D.; Tu, Q.; He, Zhili; Zhou, Jizhong

2010-01-01

Respiratory versatility and psychrophily are the hallmarks of Shewanella. The ability to utilize a wide range of electron acceptors for respiration is due to the large number of c-type cytochrome genes present in the genome of Shewanella strains. More recently the dissimilatory metal reduction of Shewanella species has been extensively and intensively studied for potential applications in the bioremediation of radioactive wastes of groundwater and subsurface environments. Multiple Shewanella genome sequences are now available in the public databases (Fredrickson et al., 2008). Most of the sequenced Shewanella strains were isolated from marine environments and this genus was believed to be of marine origin (Hau and Gralnick, 2007). However, the well-characterized model strain, S. oneidensis MR-1, was isolated from the freshwater lake sediment of Lake Oneida, New York (Myers and Nealson, 1988) and similar bacteria have also been isolated from other freshwater environments (Venkateswaran et al., 1999). Here we comparatively analyzed the genome sequence and physiological characteristics of S. putrefaciens W3-18-1 and S. oneidensis MR-1, isolated from the marine and freshwater lake sediments, respectively. The anaerobic respirations, carbon source utilization, and cell motility have been experimentally investigated. Large scale horizontal gene transfers have been revealed and the genetic divergence between these two strains was considered to be critical to the bacterial adaptation to specific habitats, freshwater or marine sediments.

Metabolic functions of Pseudomonas fluorescens strains from Populus deltoides depend on rhizosphere or endosphere isolation compartment

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Collin M Timm

2015-10-01

Full Text Available The bacterial microbiota of plants is diverse, with 1,000s of operational taxonomic units (OTUs associated with any individual plant. In this work we investigate the differences between 19 sequenced Pseudomonas fluorescens strains, isolated from Populus deltoides rhizosphere and endosphere and which represent a single OTU, using phenotypic analysis, comparative genomics, and metabolic models. While no traits were exclusive to either endosphere or rhizosphere P. fluorescens isolates, multiple pathways relevant for plant-bacterial interactions are enriched in endosphere isolate genomes. Further, growth phenotypes such as phosphate solubilization, protease activity, denitrification and root growth promotion are biased towards endosphere isolates. Endosphere isolates have significantly more metabolic pathways for plant signaling compounds and an increased metabolic range that includes utilization of energy rich nucleotides and sugars, consistent with endosphere colonization. Rhizosphere P. fluorescens have fewer pathways representative of plant-bacterial interactions but show metabolic bias towards chemical substrates often found in root exudates. This work reveals the diverse functions that may contribute to colonization of the endosphere by bacteria and are enriched among closely related isolates.

Carbon and Hydrogen Stable Isotope Fractionation during Aerobic Bacterial Degradation of Aromatic Hydrocarbons†

Science.gov (United States)

Morasch, Barbara; Richnow, Hans H.; Schink, Bernhard; Vieth, Andrea; Meckenstock, Rainer U.

2002-01-01

13C/12C and D/H stable isotope fractionation during aerobic degradation was determined for Pseudomonas putida strain mt-2, Pseudomonas putida strain F1, Ralstonia pickettii strain PKO1, and Pseudomonas putida strain NCIB 9816 grown with toluene, xylenes, and naphthalene. Different types of initial reactions used by the respective bacterial strains could be linked with certain extents of stable isotope fractionation during substrate degradation. PMID:12324375

Screening and selection of wild strains for L-arabinose isomerase production

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R. M. Manzo

2013-12-01

Full Text Available The majority of L-arabinose isomerases have been isolated by recombinant techniques, but this methodology implies a reduced technological application. For this reason, 29 bacterial strains, some of them previously characterized as L-arabinose isomerase producers, were assayed as L-arabinose fermenting strains by employing conveniently designed culture media with 0.5% (w/v L-arabinose as main carbon source. From all evaluated bacterial strains, Enterococcus faecium DBFIQ ID: E36, Enterococcus faecium DBFIQ ID: ETW4 and Pediococcus acidilactici ATCC ID: 8042 were, in this order, the best L-arabinose fermenting strains. Afterwards, to assay L-arabinose metabolization and L-arabinose isomerase activity, cell-free extract and saline precipitated cell-free extract of the three bacterial cultures were obtained and the production of ketoses was determined by the cysteine carbazole sulfuric acid method. Results showed that the greater the L-arabinose metabolization ability, the higher the enzymatic activity achieved, so Enterococcus faecium DBFIQ ID: E36 was selected to continue with production, purification and characterization studies. This work thus describes a simple microbiological method for the selection of L-arabinose fermenting bacteria for the potential production of the enzyme L-arabinose isomerase.

Ipratropium bromide delivered by metered-dose aerosol to infant ...

African Journals Online (AJOL)

Two methods of administration of ipratropium bromide (Atrovent; Boehringer Ingelheim) to wheezing children'< 25 months of age were compared: (i) the conventional nebulisation (15 children); and (ii) a metered-dose aerosol plus spacer and mask (MDA group, 17 children). The drug induced a significant and similar fall in ...

Biogenic amine formation and bacterial contribution in Natto products.

Science.gov (United States)

Kim, Bitna; Byun, Bo Young; Mah, Jae-Hyung

2012-12-01

Twenty-one Natto products currently distributed in Korea were analysed for biogenic amine contents and tested to determine physicochemical and bacterial contributions to biogenic amine formation. Among them, nine products (about 43%) had β-phenylethylamine or tyramine contents greater than the toxic dose (30mg/kg and 100mg/kg, respectively) of each amine, although no products showed total amounts of biogenic amines above the harmful level (1000mg/kg), which indicates that the amounts of biogenic amines in some Natto products are not within the safe level for human health. From four different Natto products, that contained noticeable levels of β-phenylethylamine and tyramine, 80 bacterial strains were isolated. All the strains were identified to be Bacillus subtilis and highly capable of producing β-phenylethylamine and tyramine. Therefore, it seems likely that the remarkable contents of β-phenylethylamine and tyramine in Natto predominantly resulted from the strains highly capable of producing those amines present in the food. Copyright © 2012 Elsevier Ltd. All rights reserved.

‘Corynebacterium fournierii,’ a new bacterial species isolated from the vaginal sample of a patient with bacterial vaginosis

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K. Diop

2017-07-01

Full Text Available Here we describe briefly ‘Corynebacterium fournierii’ strain Marseille P2948 (= CSUR P2948 = DSM103271, a new bacterium that was isolated from the vaginal sample of a 21-year-old woman with bacterial vaginosis.

On the existence of 'L-alanine cadmium bromide'.

Science.gov (United States)

Srinivasan, Bikshandarkoil R

2013-12-01

It is argued that the recently reported nonlinear optical crystal L-alanine cadmium bromide, grown by slow solvent evaporation method at room temperature [P. Ilayabarathi, J. Chandrasekaran, Spectrochim. Acta 96A (2012) 684-689] is the well-known L-alanine crystal. The isolation of L-alanine crystal is explained due to fractional crystallization. Copyright © 2013 Elsevier B.V. All rights reserved.

Putative bacterial interactions from metagenomic knowledge with an integrative systems ecology approach.

Science.gov (United States)

Bordron, Philippe; Latorre, Mauricio; Cortés, Maria-Paz; González, Mauricio; Thiele, Sven; Siegel, Anne; Maass, Alejandro; Eveillard, Damien

2016-02-01

Following the trend of studies that investigate microbial ecosystems using different metagenomic techniques, we propose a new integrative systems ecology approach that aims to decipher functional roles within a consortium through the integration of genomic and metabolic knowledge at genome scale. For the sake of application, using public genomes of five bacterial strains involved in copper bioleaching: Acidiphilium cryptum, Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, Leptospirillum ferriphilum, and Sulfobacillus thermosulfidooxidans, we first reconstructed a global metabolic network. Next, using a parsimony assumption, we deciphered sets of genes, called Sets from Genome Segments (SGS), that (1) are close on their respective genomes, (2) take an active part in metabolic pathways and (3) whose associated metabolic reactions are also closely connected within metabolic networks. Overall, this SGS paradigm depicts genomic functional units that emphasize respective roles of bacterial strains to catalyze metabolic pathways and environmental processes. Our analysis suggested that only few functional metabolic genes are horizontally transferred within the consortium and that no single bacterial strain can accomplish by itself the whole copper bioleaching. The use of SGS pinpoints a functional compartmentalization among the investigated species and exhibits putative bacterial interactions necessary for promoting these pathways. © 2015 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Evaluation of repetitive-PCR and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS for rapid strain typing of Bacillus coagulans.

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Jun Sato

Full Text Available In order to establish rapid and accurate typing method for Bacillus coagulans strains which is important for controlling in some canned foods and tea-based beverages manufacturing because of the high-heat resistance of the spores and high tolerance of the vegetative cells to catechins and chemicals, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS and repetitive-PCR (rep-PCR were evaluated. For this purpose, 28 strains of B. coagulans obtained from various culture collections were tested. DNA sequence analyses of the genes encoding 16S rRNA and DNA gyrase classified the test strains into two and three groups, respectively, regardless of their phenotypes. Both MALDI-TOF MS and rep-PCR methods classified the test strains in great detail. Strains classified in each group showed similar phenotypes, such as carbohydrate utilization determined using API 50CH. In particular, the respective two pairs of strains which showed the same metabolic characteristic were classified into the same group by both MALDI-TOF MS and rep-PCR methods separating from the other strains. On the other hand, the other strains which have the different profiles of carbohydrate utilization were separated into different groups by these methods. These results suggested that the combination of MALDI-TOF MS and rep-PCR analyses was advantageous for the rapid and detailed typing of bacterial strains in respect to both phenotype and genotype.

Well-Defined Copper(I) Fluoroalkoxide Complexes for Trifluoroethoxylation of Aryl and Heteroaryl Bromides

KAUST Repository

Huang, Ronglu

2015-03-17

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Copper(I) fluoroalkoxide complexes bearing dinitrogen ligands were synthesized and the structure and reactivity of the complexes toward trifluoroethoxylation, pentafluoropropoxylation, and tetrafluoropropoxylation of aryl and heteroaryl bromides were investigated. Efficiency drive: A series of copper(I) fluoroalkoxide complexes bearing N,N ligands have been prepared and structurally characterized. These well-defined complexes serve as efficient reagents for the fluoroalkoxylation of aryl and heteroaryl bromides to produce a wide range of trifluoroethyl, pentafluoropropyl, and tetrafluoropropyl (hetero)aryl ethers in good to excellent yields.

Influence of bromide on the performance of the amphipod Hyalella azteca in reconstituted waters

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Ivey, Chris D.; Ingersoll, Christopher G.

2016-01-01

Poor performance of the amphipod Hyalella azteca has been observed in exposures using reconstituted waters. Previous studies have reported success in H. azteca water-only exposures with the addition of relatively high concentrations of bromide. The present study evaluated the influence of lower environmentally representative concentrations of bromide on the response ofH. azteca in 42-d water-only exposures. Improved performance of H. azteca was observed in reconstituted waters with >0.02 mg Br/L.

Characterization of Exoelectrogenic Bacteria Enterobacter Strains Isolated from a Microbial Fuel Cell Exposed to Copper Shock Load

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Feng, Cuijie; Li, Jiangwei; Qin, Dan; Chen, Lixiang; Zhao, Feng; Chen, Shaohua; Hu, Hongbo; Yu, Chang-Ping

2014-01-01

Microorganisms capable of generating electricity in microbial fuel cells (MFCs) have gained increasing interest. Here fourteen exoelectrogenic bacterial strains were isolated from the anodic biofilm in an MFC before and after copper (Cu) shock load by Hungate roll-tube technique with solid ferric (III) oxide as an electron acceptor and acetate as an electron donor. Phylogenetic analysis of the 16S rRNA gene sequences revealed that they were all closely related to Enterobacter ludwigii DSM 16688T within the Enterobacteriaceae family, although these isolated bacteria showed slightly different morphology before and after Cu shock load. Two representative strains R2B1 (before Cu shock load) and B4B2 (after Cu shock load) were chosen for further analysis. B4B2 is resistant to 200 mg L−1 of Cu(II) while R2B1 is not, which indicated the potential selection of the Cu shock load. Raman analysis revealed that both R2B1 and B4B2 contained c-type cytochromes. Cyclic voltammetry measurements revealed that strain R2B1 had the capacity to transfer electrons to electrodes. The experimental results demonstrated that strain R2B1 was capable of utilizing a wide range of substrates, including Luria-Bertani (LB) broth, cellulose, acetate, citrate, glucose, sucrose, glycerol and lactose to generate electricity, with the highest current density of 440 mA·m−2 generated from LB-fed MFC. Further experiments indicated that the bacterial cell density had potential correlation with the current density. PMID:25412475

Characterization of exoelectrogenic bacteria enterobacter strains isolated from a microbial fuel cell exposed to copper shock load.

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Cuijie Feng

Full Text Available Microorganisms capable of generating electricity in microbial fuel cells (MFCs have gained increasing interest. Here fourteen exoelectrogenic bacterial strains were isolated from the anodic biofilm in an MFC before and after copper (Cu shock load by Hungate roll-tube technique with solid ferric (III oxide as an electron acceptor and acetate as an electron donor. Phylogenetic analysis of the 16S rRNA gene sequences revealed that they were all closely related to Enterobacter ludwigii DSM 16688T within the Enterobacteriaceae family, although these isolated bacteria showed slightly different morphology before and after Cu shock load. Two representative strains R2B1 (before Cu shock load and B4B2 (after Cu shock load were chosen for further analysis. B4B2 is resistant to 200 mg L-1 of Cu(II while R2B1 is not, which indicated the potential selection of the Cu shock load. Raman analysis revealed that both R2B1 and B4B2 contained c-type cytochromes. Cyclic voltammetry measurements revealed that strain R2B1 had the capacity to transfer electrons to electrodes. The experimental results demonstrated that strain R2B1 was capable of utilizing a wide range of substrates, including Luria-Bertani (LB broth, cellulose, acetate, citrate, glucose, sucrose, glycerol and lactose to generate electricity, with the highest current density of 440 mA·m-2 generated from LB-fed MFC. Further experiments indicated that the bacterial cell density had potential correlation with the current density.

[Effect of the 10 kb sequence of piscine Streptococcus agalactiae on bacterial virulence].

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Liu, Guangjin; Zhu, Jielian; Shi, Ziwei; Ding, Ming; Wang, Ruyi; Yao, Huochun; Lu, Chengping; Xu, Pao

2016-01-04

From the previous comparative genomic analysis, we found a specific unknown 10 kb sequence (including 11 Open reading Frames) in Chinese piscine strain GD201008-001 genome. To study the role of 10 kb in the pathogenicity of piscine S. agalactiae, the 10 kb sequence was deleted from the GD201008-001 genome. The isogenic mutant Δ10 kb was constructed by using the temperature-sensitive Streptococcus-E. coli shuttle vector pSET4s. We compared the growth characteristics, adherence to HEp-2 cell and bacterial virulence in a zebrafish infection model between wild strain and mutant. Meanwhile the expressions of the known virulence genes from GD201008-001 and Δ10 kb were also quantified by real-time PCR. The Δ10 kb showed no significant differences in bacterial morphology and adherence to HEp-2 cells compared with the wild-type strain, but the speed of growth was slightly slower than the wild strain. Furthermore the 50% lethal dose of Δ10 kb was decreased up to 10-fold (P kb sequence of piscine Streptococcus agalactiae exerts a significant effect on bacterial virulence and probably regulates the virulence genes expression of GD20 1008-001.

Diversity and biological activities of the bacterial community associated with the marine sponge Phorbas tenacior (Porifera, Demospongiae).

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Dupont, S; Carré-Mlouka, A; Descarrega, F; Ereskovsky, A; Longeon, A; Mouray, E; Florent, I; Bourguet-Kondracki, M L

2014-01-01

The diversity of the cultivable microbiota of the marine sponge Phorbas tenacior frequently found in the Mediterranean Sea was investigated, and its potential as a source of antimicrobial, antioxidant and antiplasmodial compounds was evaluated. The cultivable bacterial community was studied by isolation, cultivation and 16S rRNA gene sequencing. Twenty-three bacterial strains were isolated and identified in the Proteobacteria (α or γ classes) and Actinobacteria phyla. Furthermore, three different bacterial morphotypes localized extracellularly within the sponge tissues were revealed by microscopic observations. Bacterial strains were assigned to seven different genera, namely Vibrio, Photobacterium, Shewanella, Pseudomonas, Ruegeria, Pseudovibrio and Citricoccus. The strains affiliated to the same genus were differentiated according to their genetic dissimilarities using random amplified polymorphic DNA (RAPD) analyses. Eleven bacterial strains were selected for evaluation of their bioactivities. Three isolates Pseudovibrio P1Ma4, Vibrio P1MaNal1 and Citricoccus P1S7 revealed antimicrobial activity; Citricoccus P1S7 and Vibrio P1MaNal1 isolates also exhibited antiplasmodial activity, while two Vibrio isolates P1Ma8 and P1Ma5 displayed antioxidant activity. These data confirmed the importance of Proteobacteria and Actinobacteria associated with marine sponges as a reservoir of bioactive compounds. This study presents the first report on the diversity of the cultivable bacteria associated with the marine sponge Phorbas tenacior, frequently found in the Mediterranean Sea. Evaluation of the antiplasmodial, antimicrobial and antioxidant activities of the isolates has been investigated and allowed to select bacterial strains, confirming the importance of Proteobacteria and Actinobacteria as sources of bioactive compounds. © 2013 The Society for Applied Microbiology.

Paenibacillus motobuensis sp. nov., isolated from a composting machine utilizing soil from Motobu-town, Okinawa, Japan.

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Iida, Ken-ichiro; Ueda, Yasuichi; Kawamura, Yoshiaki; Ezaki, Takayuki; Takade, Akemi; Yoshida, Shin-ichi; Amako, Kazunobu

2005-09-01

A novel bacterial strain, MC10(T), was isolated from a compost sample produced in a composting machine utilizing soil from Motobu-town, Okinawa, Japan. The isolate was Gram-negative, but produced endospores. These conflicting characters prompted a taxonomic study of the isolate. The isolate was examined using a combination of phenotypic characterization, cellular fatty acid analysis, DNA base composition determination and 16S rRNA gene sequence analysis. Phylogenetic analysis, based on 16S rRNA gene sequence comparisons, placed strain MC10(T) within the genus Paenibacillus. As in other Paenibacillus species, the isolate contained anteiso-C(15:0) as the major fatty acid and the DNA G+C content was 47.0 mol%. However, 16S rRNA gene sequence similarity values of less than 95.6% were found between this isolate and all members of the genus Paenibacillus. Based upon these results, strain MC10(T) (=GTC 1835(T)=JCM 12774(T)=CCUG 50090(T)) should be designated as the type strain of a novel species within the genus Paenibacillus, Paenibacillus motobuensis sp. nov.