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Sample records for arsenite-oxidizing bacteria isolated

  1. Isolation and Characterization of Arsenite-Oxidation Bacteria From Arsenic-contaminated Groundwater in Blackfoot Disease Region in Taiwan

    NASA Astrophysics Data System (ADS)

    Hsu, H.; Hsiao, S.; Liu, C.; Liao, C.; Chang, F.; Liao, V. H.

    2006-12-01

    Arsenic is an environmental carcinogen of toxicological concern. Although arsenic is generally toxic to life, it has been demonstrated that some microorganisms can use arsenic compounds as electron donors, electron acceptors, or possess arsenic detoxification mechanisms. Increasing evidences suggest that the biogeochemical cycle of arsenic is significant dependent on microbial transformations which affect the distribution and the mobility of arsenic species in the environment. However, the roles of the bacteria in the arsenic cycles are yet to be fully elucidated. In this study, we isolate As(V)-As(III) redox bacteria using arsenic-contaminated groundwater in Blackfoot disease region in Taiwan under oxic condition. Two hundred and nineteen arsenic-resistant heterotrophic bacterial strains were isolated. Analysis of the 16S rRNA gene sequence of some bacteria revealed that some of bacteria have been indicated involving in arsenic transformation, while others have not been reported to be associated with arsenic transformation. Of these isolated bacteria, one designated as L7506 was selected for further investigation. Strain L7506 is a Gram- negative, straight to curved rod, and motile bacteria. It belongs to genus Bosea based on 16S rRNA sequence analysis. The optimal growth condition was at pH 6-7, 37'C in LB medium. Moreover, it was able to grow in the presence of 100mM arsenate. L7506 began to significantly oxidize arsenite (2mM) to arsenate after 3-day incubation and complete the oxidation process after 10-day incubation. To further explore the genetic basis for the regulation of arsenite oxidation, transposon Tn5 mutagenesis was used to identify genetic determinants required for arsenite oxidation in L7506 and it is in progress. Results from this study show that diverse bacteria were isolated from arsenic-contaminated groundwater in Blackfoot disease region in Taiwan. The identified As(III)-oxidizing bacteria may be potentially used for bioremediation of arsenic

  2. Characterization of arsenite-oxidizing bacteria isolated from arsenic-contaminated groundwater of West Bengal.

    PubMed

    Paul, Dhiraj; Poddar, Soumya; Sar, Pinaki

    2014-01-01

    Nine arsenic (As)-resistant bacterial strains isolated from As-rich groundwater samples of West Bengal were characterized to elucidate their potential in geomicrobial transformation and bioremediation aspects. The 16S rRNA gene-based phylogenetic analysis revealed that the strains were affiliated with genera Actinobacteria, Microbacterium, Pseudomonas and Rhizobium. The strains exhibited high resistance to As [Minimum inhibitory concentration (MIC) ≥ 10 mM As(3+) and MIC ≥ 450 mM As(5+)] and other heavy metals, e.g., Cu(2+), Cr(2+), Ni(2+), etc. (MIC ≥ 2 mM) as well as As transformation (As(3+) oxidation and As(5+) reduction) capabilities. Their ability to utilize diverse carbon source(s) including hydrocarbons and different alternative electron acceptor(s) (As(5+), SO4(2-), S2O3(2-), etc.) during anaerobic growth was noted. Growth at wide range of pH, temperature and salinity, production of siderophore and biofilm were observed. Together with these, growth pattern and transformation kinetics indicated a high As(3+) oxidation activity of the isolates Rhizobium sp. CAS934i, Microbacterium sp. CAS905i and Pseudomonas sp. CAS912i. A positive relation between high As(3+) resistance and As(3+) oxidation and the supportive role of As(3+) in bacterial growth was noted. The results highlighted As(3+) oxidation process and metabolic repertory of strains indigenous to contaminated groundwater and indicates their potential in As(3+) detoxification. Thus, such metabolically well equipped bacterial strains with highest As(3+) oxidation activities may be used for bioremediation of As contaminated water and effluents in the near future. PMID:25137536

  3. Arsenite-oxidizing bacteria exhibiting plant growth promoting traits isolated from the rhizosphere of Oryza sativa L.: Implications for mitigation of arsenic contamination in paddies.

    PubMed

    Das, Suvendu; Jean, Jiin-Shuh; Chou, Mon-Lin; Rathod, Jagat; Liu, Chia-Chuan

    2016-01-25

    Arsenite-oxidizing bacteria exhibiting plant growth promoting (PGP) traits can have the advantages of reducing As-uptake by rice and promoting plant growth in As-stressed soil. A gram-positive bacterium Bacillus flexus ASO-6 resistant to high levels of As (32 and 280 mM for arsenite and arsenate, respectively) and exhibiting elevated rates of As(III) oxidation (Vmax=1.34 μM min(-1) 10(-7) cell) was isolated from rhizosphere of rice. The presence of aoxB gene and exhibition of As(III)-oxidase enzyme activity of this strain was observed. The ability of the strain to produce siderophore, IAA, ACC-deaminase and to solubilize phosphate was verified. The rice seed treated with the strain exhibited significantly improved seed germination and seedling vigor compared with the un-inoculated seeds. The bacterial inoculation significantly increased root biomass, straw yield, grain yield, chlorophyll and carotenoid in the rice plant. Moreover, As uptake from root to shoot and As accumulation in straw and grain decreased significantly as a result of the bacterial inoculation. Noteworthy, the inoculation effect is more prominent in non-flooded soil than it is in flooded soil. Owing to its wide action spectrum, this As(III)-oxidizing PGPB could serve as a potential bio-inoculant for mitigation of As in paddies and sustainable rice production in As-contaminated areas. PMID:26448489

  4. Arsenite-oxidizing bacteria exhibiting plant growth promoting traits isolated from the rhizosphere of Oryza sativa L.: Implications for mitigation of arsenic contamination in paddies.

    PubMed

    Das, Suvendu; Jean, Jiin-Shuh; Chou, Mon-Lin; Rathod, Jagat; Liu, Chia-Chuan

    2016-01-25

    Arsenite-oxidizing bacteria exhibiting plant growth promoting (PGP) traits can have the advantages of reducing As-uptake by rice and promoting plant growth in As-stressed soil. A gram-positive bacterium Bacillus flexus ASO-6 resistant to high levels of As (32 and 280 mM for arsenite and arsenate, respectively) and exhibiting elevated rates of As(III) oxidation (Vmax=1.34 μM min(-1) 10(-7) cell) was isolated from rhizosphere of rice. The presence of aoxB gene and exhibition of As(III)-oxidase enzyme activity of this strain was observed. The ability of the strain to produce siderophore, IAA, ACC-deaminase and to solubilize phosphate was verified. The rice seed treated with the strain exhibited significantly improved seed germination and seedling vigor compared with the un-inoculated seeds. The bacterial inoculation significantly increased root biomass, straw yield, grain yield, chlorophyll and carotenoid in the rice plant. Moreover, As uptake from root to shoot and As accumulation in straw and grain decreased significantly as a result of the bacterial inoculation. Noteworthy, the inoculation effect is more prominent in non-flooded soil than it is in flooded soil. Owing to its wide action spectrum, this As(III)-oxidizing PGPB could serve as a potential bio-inoculant for mitigation of As in paddies and sustainable rice production in As-contaminated areas.

  5. Arsenite-oxidizing and arsenate-reducing bacteria associated with arsenic-rich groundwater in Taiwan

    NASA Astrophysics Data System (ADS)

    Liao, Vivian Hsiu-Chuan; Chu, Yu-Ju; Su, Yu-Chen; Hsiao, Sung-Yun; Wei, Chia-Cheng; Liu, Chen-Wuing; Liao, Chung-Min; Shen, Wei-Chiang; Chang, Fi-John

    2011-04-01

    Drinking highly arsenic-contaminated groundwater is a likely cause of blackfoot disease in Taiwan, but microorganisms that potentially control arsenic mobility in the subsurface remain unstudied. The objective of this study was to investigate the relevant arsenite-oxidizing and arsenate-reducing microbial community that exists in highly arsenic-contaminated groundwater in Taiwan. We cultured and identified arsenic-transforming bacteria, analyzed arsenic resistance and transformation, and determined the presence of genetic markers for arsenic transformation. In total, 11 arsenic-transforming bacterial strains with different colony morphologies and varying arsenic transformation abilities were isolated, including 10 facultative anaerobic arsenate-reducing bacteria and one strictly aerobic arsenite-oxidizing bacterium. All of the isolates exhibited high levels of arsenic resistance with minimum inhibitory concentrations of arsenic ranging from 2 to 200 mM. Strain AR-11 was able to rapidly oxidize arsenite to arsenate at concentrations relevant to environmental groundwater samples without the addition of any electron donors or acceptors. We provide evidence that arsenic-reduction activity may be conferred by the ars operon(s) that were not amplified by the designed primers currently in use. The 16S rRNA sequence analysis grouped the isolates into the following genera: Pseudomonas, Bacillus, Psychrobacter, Vibrio, Citrobacter, Enterobacter, and Bosea. Among these genera, we present the first report of the genus Psychrobacter being involved in arsenic reduction. Our results further support the hypothesis that bacteria capable of either oxidizing arsenite or reducing arsenate coexist and are ubiquitous in arsenic-contaminated groundwater.

  6. Arsenite-oxidizing Hydrogenobaculum strain isolated from an acid-sulfate-chloride geothermal spring in Yellowstone National Park.

    PubMed

    Donahoe-Christiansen, Jessica; D'Imperio, Seth; Jackson, Colin R; Inskeep, William P; McDermott, Timothy R

    2004-03-01

    An arsenite-oxidizing Hydrogenobaculum strain was isolated from a geothermal spring in Yellowstone National Park, Wyo., that was previously shown to contain microbial populations engaged in arsenite oxidation. The isolate was sensitive to both arsenite and arsenate and behaved as an obligate chemolithoautotroph that used H(2) as its sole energy source and had an optimum temperature of 55 to 60 degrees C and an optimum pH of 3.0. The arsenite oxidation in this organism displayed saturation kinetics and was strongly inhibited by H(2)S.

  7. Arsenite-Oxidizing Hydrogenobaculum Strain Isolated from an Acid-Sulfate-Chloride Geothermal Spring in Yellowstone National Park

    PubMed Central

    Donahoe-Christiansen, Jessica; D'Imperio, Seth; Jackson, Colin R.; Inskeep, William P.; McDermott, Timothy R.

    2004-01-01

    An arsenite-oxidizing Hydrogenobaculum strain was isolated from a geothermal spring in Yellowstone National Park, Wyo., that was previously shown to contain microbial populations engaged in arsenite oxidation. The isolate was sensitive to both arsenite and arsenate and behaved as an obligate chemolithoautotroph that used H2 as its sole energy source and had an optimum temperature of 55 to 60°C and an optimum pH of 3.0. The arsenite oxidation in this organism displayed saturation kinetics and was strongly inhibited by H2S. PMID:15006819

  8. Arsenite oxidizing Thiomonas strains isolated from different mining sites

    NASA Astrophysics Data System (ADS)

    Battaglia-Brunet, F.; Duquesne, K.; Dictor, M. C.; Garrido, F.; Bonnefoy, V.; Baranger, P.; Morin, D.

    2003-04-01

    Arsenic is commonly found in sulfide rocks and ores. This toxic metalloid is transferred to the water phase through acidophilic bio-oxidation of sulfides in mining galleries and waste dumps. Inorganic arsenic As(III) and As(V) are both soluble anions, however As(III) is more mobile and toxic than As(V). Bacteria can participate to the biogeochemical arsenic cycling through As(III) oxidation or As(V) reduction. Mineral selective media, containing As(III) as sole energy source, were used to isolate As(III)-oxidizing bacteria from two disused mining sites. Cheni site (Haute Vienne) was a gold mine, and Carnoules (Gard) was lead-zinc mine. Both sites are highly contaminated with arsenic. Samples of sediments and water from Cheni (pH 6) and Carnoules (pH 3) were used to inoculate mineral selective media whose pH were adjusted to those of the sampling environments. In both cases, organisms belonging to the genus Thiomonas were selected, then isolated. These bacteria oxidize arsenite during their exponential growth phase. The Both bacteria are able to grow, as a pure strains, in autotrophic conditions. The As(III)-oxidase activity of the Carnoules strain was exclusively found in cells cultivated with arsenite, and was associated to the membrane. If they can use As(III) as energetic substrate, Thiomonas-related organisms may play an important role in the biogeochemical cycling of arsenic within mining ecosystems.

  9. Removal of arsenic from groundwater by arsenite-oxidizing bacteria.

    PubMed

    Ike, M; Miyazaki, T; Yamamoto, N; Sei, K; Soda, S

    2008-01-01

    The presence of arsenic in groundwater has been of great public concern because of its high toxicity. For purification of arsenic-contaminated groundwater, bacterial oxidation of arsenite, As(III), with a chemical adsorption process was examined in this study. After As(III) oxidation to arsenate, As(V), arsenic is easily removable from contaminated groundwater because As(V) is more adsorptive to absorbents than As(III). By acclimation to As(III) of high concentrations, a mixed culture of heterotrophic bacteria with high As(III)-oxidizing activity was obtained from a soil sample that was free from contamination. With initial concentration up to 1,500 mg l(-1) As(III), the mixed culture showed high As(III)-oxidizing activity at pH values of 7-10 and at temperatures of 25-35 degrees C. The mixed culture contained several genera of heterotrophic As(III)-oxidizing and arsenic-tolerant bacteria: Haemophilus, Micrococcus, and Bacillus. Activated alumina was added to the basal salt medium containing 75 mg l(-1) As(III) before and after bacterial oxidation. Arsenic removal by activated alumina was greatly enhanced by bacterial oxidation of As(III) to As(V). The isotherms of As(III) and As(V) onto activated alumina verified that bacterial As(III) oxidation is a helpful pretreatment process for the conventional adsorption process for arsenic removal.

  10. Arsenite Oxidation by Anaerobic Bacteria in Mono Lake, California

    NASA Astrophysics Data System (ADS)

    Hoeft, S. E.; Oremland, R. S.

    2001-12-01

    Mono Lake, California is a meromictic soda lake (pH = 9.8; salinity = 70-90 g/L) with exceptionally high arsenic content (200 μ M) derived from hydrothermal sources. Previous work has shown that arsenic speciation changes from arsenate [As(V)] to the more reduced arsenite [As(III)] with vertical transition from the lake's surface oxic waters to its unmixed, anoxic bottom waters and that dissimilatory reduction is responsible for the observed change in arsenic speciation (Oremland et al., 2000). Depth profiles of arsenic speciation indicate that a small amount of As(V) exists in the anoxic bottom waters, suggesting a constant re-supply by microbial oxidation of As(III). Anaerobic microbial oxidation of As(III) to As(V) was first noted in arsenate-enriched anoxic bottom water amended with nitrate, where nitrate addition caused a rapid microbial re-oxidation of arsenite to arsenate (Hoeft et al. 2001). In following, we conducted time course experiments with As(III)-amended bottom waters supplemented with either 5 mM nitrate, Fe(III)-NTA or nitrite. Nitrate-amended waters formed As(V), while killed controls did not form significant amounts and 5 mM nitrate was completely reduced to 5 mM nitrite by the end of the incubation. Live samples amended with 5mM Fe(III)-NTA produced As(V) that exceeded production of As(V) in killed controls, while nitrite-amended waters formed As(V) in excess of killed controls after an initial lag. We isolated a pure culture, strain MLHE-1, that grows in minimal salts media by oxidation of As(III) to As(V) with the reduction of equivalent quantities of nitrate to nitrite. Strain MLHE-1 appears to be a chemoautotroph. These results demonstrate that the cycling of As(V) and As(III) can be sustained in the absence of oxygen. This has implications not only for the recycling of As(V) in Mono Lake's bottom waters, but also for the mobility of arsenic in aquifers as well. Oremland, R.S. et al. 2000. Geochim. Cosmochim. Acta 64: 3073-3084. Hoeft, S

  11. Arsenite oxidation by a facultative chemolithoautotrophic Sinorhizobium sp. KGO-5 isolated from arsenic-contaminated soil.

    PubMed

    Dong, Dan; Ohtsuka, Toshihiko; Dong, Dian Tao; Amachi, Seigo

    2014-01-01

    A chemolithoautotrophic arsenite-oxidizing bacterium, designated strain KGO-5, was isolated from arsenic-contaminated industrial soil. Strain KGO-5 was phylogenetically closely related with Sinorhizobium meliloti with 16S rRNA gene similarity of more than 99%, and oxidized 5 mM arsenite under autotrophic condition within 60 h with a doubling time of 3.0 h. Additions of 0.01-0.1% yeast extract enhanced the growth significantly, and the strain still oxidized arsenite efficiently with much lower doubling times of approximately 1.0 h. Arsenite-oxidizing capacities (11.2-54.1 μmol h(-1) mg dry cells(-1)) as well as arsenite oxidase (Aio) activities (1.76-10.0 mU mg protein(-1)) were found in the cells grown with arsenite, but neither could be detected in the cells grown without arsenite. Strain KGO-5 possessed putative aioA gene, which is closely related with AioA of Ensifer adhaerens. These results suggest that strain KGO-5 is a facultative chemolithoautotrophic arsenite oxidizer, and its Aio is induced by arsenic. PMID:25051896

  12. The fate of arsenic adsorbed on iron oxides in the presence of arsenite-oxidizing bacteria.

    PubMed

    Zhang, Zhennan; Yin, Naiyi; Du, Huili; Cai, Xiaolin; Cui, Yanshan

    2016-05-01

    Arsenic (As) is a redox-active metalloid whose toxicity and mobility in soil depend on its oxidation state. Arsenite [As(III)] can be oxidized by microbes and adsorbed by minerals in the soil. However, the combined effects of these abiotic and biotic processes are not well understood. In this study, the fate of arsenic in the presence of an isolated As(III)-oxidizing bacterium (Pseudomonas sp. HN-1, 10(9) colony-forming units (CFUs)·ml(-1)) and three iron oxides (goethite, hematite, and magnetite at 1.6 g L(-1)) was determined using batch experiments. The total As adsorption by iron oxides was lower with bacteria present and was higher with iron oxides alone. The total As adsorption decreased by 78.6%, 36.0% and 79.7% for goethite, hematite and magnetite, respectively, due to the presence of bacteria. As(III) adsorbed on iron oxides could also be oxidized by Pseudomonas sp. HN-1, but the oxidation rate (1.3 μmol h(-1)) was much slower than the rate in the aqueous phase (96.2 μmol h(-1)). Therefore, the results of other studies with minerals only might overestimate the adsorptive capacity of solids in natural systems; the presence of minerals might hinder As(III) oxidation by microbes. Under aerobic conditions, in the presence of iron oxides and As(III)-oxidizing bacteria, arsenic is adsorbed onto iron oxides within the adsorption capacity, and As(V) is the primary form in the solid and aqueous phases.

  13. Removal of arsenic from groundwater by using a native isolated arsenite-oxidizing bacterium.

    PubMed

    Kao, An-Chieh; Chu, Yu-Ju; Hsu, Fu-Lan; Liao, Vivian Hsiu-Chuan

    2013-12-01

    Arsenic (As) contamination of groundwater is a significant public health concern. In this study, the removal of arsenic from groundwater using biological processes was investigated. The efficiency of arsenite (As(III)) bacterial oxidation and subsequent arsenate (As(V)) removal from contaminated groundwater using bacterial biomass was examined. A novel As(III)-oxidizing bacterium (As7325) was isolated from the aquifer in the blackfoot disease (BFD) endemic area in Taiwan. As7325 oxidized 2300μg/l As(III) using in situ As(III)-contaminated groundwater under aerobic conditions within 1d. After the oxidation of As(III) to As(V), As(V) removal was further examined using As7325 cell pellets. The results showed that As(V) could be adsorbed efficiently by lyophilized As7325 cell pellets, the efficiency of which was related to lyophilized cell pellet concentration. Our study conducted the examination of an alternative technology for the removal of As(III) and As(V) from groundwater, indicating that the oxidation of As(III)-contaminated groundwater by native isolated bacterium, followed by As(V) removal using bacterial biomass is a potentially effective technology for the treatment of As(III)-contaminated groundwater.

  14. Rapid arsenite oxidation by Thermus aquaticus and Thermus thermophilus: Field and laboratory investigations

    USGS Publications Warehouse

    Gihring, T.M.; Druschel, G.K.; McCleskey, R.B.; Hamers, R.J.; Banfield, J.F.

    2001-01-01

    Thermus aquaticus and Thermus thermophilus, common inhabitants of terrestrial hot springs and thermally polluted domestic and industrial waters, have been found to rapidly oxidize arsenite to arsenate. Field investigations at a hot spring in Yellowstone National Park revealed conserved total arsenic transport and rapid arsenite oxidation occurring within the drainage channel. This environment was heavily colonized by Thermus aquaticus. In laboratory experiments, arsenite oxidation by cultures of Thermus aquaticus YT1 (previously isolated from Yellowstone National Park) and Thermus thermophilus HB8 was accelerated by a factor of over 100 relative to abiotic controls. Thermus aquaticus and Thermus thermophilus may therefore play a large and previously unrecognized role in determining arsenic speciation and bioavailability in thermal environments.

  15. Diversity of arsenite oxidizing bacterial communities in arsenic-rich deltaic aquifers in West Bengal, India

    PubMed Central

    Ghosh, Devanita; Bhadury, Punyasloke; Routh, Joyanto

    2014-01-01

    High arsenic (As) concentration in groundwater has affected human health, particularly in South-East Asia putting millions of people at risk. Biogeochemical cycling of As carried out by different bacterial groups are suggested to control the As fluxes in aquifers. A functional diversity approach in link with As precipitation was adopted to study bacterial community structures and their variation within the As contaminated Bengal Delta Plain (BDP) aquifers of India. Groundwater samples collected from two shallow aquifers in Karimpur II (West Bengal, India), during years 2010 and 2011, were investigated to trace the effects immediately after monsoon period (precipitation) on community structure and diversity of bacterial assemblages with a focus on arsenite oxidizing bacterial phyla for two successive years. The study focused on amplification, clone library generation and sequencing of the arsenite oxidase large sub-unit gene aioA and 16S rRNA marker, with respect to changes in elemental concentrations. New set of primers were designed to amplify the aioA gene as a phylogenetic marker to study taxonomically diverse arsenite oxidizing bacterial groups in these aquifers. The overall narrow distribution of bacterial communities based on aioA and 16S rRNA sequences observed was due to poor nutrient status and anoxic conditions in these As contaminated aquifers. Proteobacteria was the dominant phylum detected, within which Acidovorax, Hydrogenophaga, Albidiferax, Bosea, and Polymorphum were the major arsenite oxidizing bacterial genera based on the number of clones sequenced. The structure of bacterial assemblages including those of arsenite oxidizing bacteria seems to have been affected by increase in major elemental concentrations (e.g., As, Fe, S, and Si) within two sampling sessions, which was supported by statistical analyses. One of the significant findings of this study is detection of novel lineages of 16S rRNA-like bacterial sequences indicating presence of

  16. Construction of the recombinant broad-host-range plasmids providing their bacterial hosts arsenic resistance and arsenite oxidation ability.

    PubMed

    Drewniak, Lukasz; Ciezkowska, Martyna; Radlinska, Monika; Sklodowska, Aleksandra

    2015-02-20

    The plasmid pSinA of Sinorhizobium sp. M14 was used as a source of functional phenotypic modules, encoding proteins involved in arsenite oxidation and arsenic resistance, to obtain recombinant broad-host-range plasmids providing their bacterial hosts arsenic resistance and arsenite oxidative ability. An arsenite oxidation module was cloned into pBBR1MCS-2 vector yielding plasmid vector pAIO1, while an arsenic resistance module was cloned into pCM62 vector yielding plasmid pARS1. Both plasmid constructs were introduced (separately and together) into the cells of phylogenetically distant (representing Alpha-, Beta-, and Gammaproteobacteria) and physiologically diversified (unable to oxidize arsenite and susceptible/resistant to arsenite and arsenate) bacteria. Functional analysis of the modified strains showed that: (i) the plasmid pARS1 can be used for the construction of strains with an increased resistance to arsenite [up to 20mM of As(III), (ii) the presence of the plasmid pAIO1 in bacteria previously unable to oxidize As(III) to As(V), contributes to the acquisition of arsenite oxidation abilities by these cells, (iii) the highest arsenite utilization rate are observed in the culture of strains harbouring both the plasmids pAIO1 and pARS1, (iv) the strains harbouring the plasmid pAIO1 were able to grow on arsenic-contaminated mine waters (∼ 3.0 mg As L(-1)) without any supplementation.

  17. Bacteria isolated from amoebae/bacteria consortium

    DOEpatents

    Tyndall, R.L.

    1995-05-30

    New protozoan derived microbial consortia and method for their isolation are provided. Consortia and bacteria isolated therefrom are useful for treating wastes such as trichloroethylene and trinitrotoluene. Consortia, bacteria isolated therefrom, and dispersants isolated therefrom are useful for dispersing hydrocarbons such as oil, creosote, wax, and grease.

  18. Bacteria isolated from amoebae/bacteria consortium

    DOEpatents

    Tyndall, Richard L.

    1995-01-01

    New protozoan derived microbial consortia and method for their isolation are provided. Consortia and bacteria isolated therefrom are useful for treating wastes such as trichloroethylene and trinitrotoluene. Consortia, bacteria isolated therefrom, and dispersants isolated therefrom are useful for dispersing hydrocarbons such as oil, creosote, wax, and grease.

  19. Long-term performance of rapid oxidation of arsenite in simulated groundwater using a population of arsenite-oxidizing microorganisms in a bioreactor.

    PubMed

    Li, Hao; Zeng, Xian-Chun; He, Zhong; Chen, Xiaoming; E, Guoji; Han, Yiyang; Wang, Yanxin

    2016-09-15

    A population of arsenite-oxidizing microorganisms enriched from the tailing of the Shimen realgar mine was used to generate biofilms on the surfaces of perlites. This bioreactor is able to completely oxidize 1100 μg/L As(III) dissolved in simulated groundwater into As(V) within 10 min; after 140 days of operation, approximately 20 min were required to completely oxidize the same concentration of As(III). Analysis for the 16S rRNA genes of the microbial community showed that Bacteroidetes and Proteobacteria are dominant in the reactor. Six different bacterial strains were randomly isolated from the reactor. Function and gene analysis indicated that all the isolates possess arsenite-oxidizing activity, and five of them are chemoautotrophic. Further analysis showed that a large diversity of AioAs and two types of RuBisCOs are present in the microbial community. This suggests that many chemoautotrophic arsenite-oxidizing microorganisms were responsible for quick oxidation of arsenite in the reactor. We also found that the reactor is easily regenerated and its number is readily expanded. To the best of our knowledge, the arsenite-oxidizing efficiency, which was expressed as the minimum time for complete oxidization of a certain concentration of As(III) under a single operation, of this bioreactor is the highest among the described bioreactors; it is also the most stable, economic and environment-friendly.

  20. Long-term performance of rapid oxidation of arsenite in simulated groundwater using a population of arsenite-oxidizing microorganisms in a bioreactor.

    PubMed

    Li, Hao; Zeng, Xian-Chun; He, Zhong; Chen, Xiaoming; E, Guoji; Han, Yiyang; Wang, Yanxin

    2016-09-15

    A population of arsenite-oxidizing microorganisms enriched from the tailing of the Shimen realgar mine was used to generate biofilms on the surfaces of perlites. This bioreactor is able to completely oxidize 1100 μg/L As(III) dissolved in simulated groundwater into As(V) within 10 min; after 140 days of operation, approximately 20 min were required to completely oxidize the same concentration of As(III). Analysis for the 16S rRNA genes of the microbial community showed that Bacteroidetes and Proteobacteria are dominant in the reactor. Six different bacterial strains were randomly isolated from the reactor. Function and gene analysis indicated that all the isolates possess arsenite-oxidizing activity, and five of them are chemoautotrophic. Further analysis showed that a large diversity of AioAs and two types of RuBisCOs are present in the microbial community. This suggests that many chemoautotrophic arsenite-oxidizing microorganisms were responsible for quick oxidation of arsenite in the reactor. We also found that the reactor is easily regenerated and its number is readily expanded. To the best of our knowledge, the arsenite-oxidizing efficiency, which was expressed as the minimum time for complete oxidization of a certain concentration of As(III) under a single operation, of this bioreactor is the highest among the described bioreactors; it is also the most stable, economic and environment-friendly. PMID:27288673

  1. The genetic basis of anoxygenic photosynthetic arsenite oxidation

    USGS Publications Warehouse

    Hernandez-Maldonado, Jamie; Sanchez-Sedillo, Benjamin; Stoneburner, Brendon; Boren, Alison; Miller, Laurence G.; McCann, Shelley; Rosen, Michael R.; Oremland, Ronald S.; Saltikov, Chad W.

    2016-01-01

    “Photoarsenotrophy”, the use of arsenite as an electron donor for anoxygenic photosynthesis, is thought to be an ancient form of phototrophy along with the photosynthetic oxidation of Fe(II), H2S, H2, and NO2-. Photoarsenotrophy was recently identified from Paoha Island's (Mono Lake, CA) arsenic-rich hot springs. The genomes of several photoarsenotrophs revealed a gene cluster, arxB2AB1CD, where arxA is predicted to encode for the sole arsenite oxidase. The role of arxA in photosynthetic arsenite oxidation was confirmed by disrupting the gene in a representative photoarsenotrophic bacterium, resulting in the loss of light-dependent arsenite oxidation. In situ evidence of active photoarsenotrophic microbes was supported by arxA mRNA detection for the first time, in red-pigmented microbial mats within the hot springs of Paoha Island. This work expands on the genetics for photosynthesis coupled to new electron donors and elaborates on known mechanisms for arsenic metabolism, thereby highlighting the complexities of arsenic biogeochemical cycling.

  2. Arsenite modifies structure of soil microbial communities and arsenite oxidization potential.

    PubMed

    Lami, Raphaël; Jones, L Camille; Cottrell, Matthew T; Lafferty, Brandon J; Ginder-Vogel, M; Sparks, Donald L; Kirchman, David L

    2013-05-01

    The influence of arsenite [As(III)] on natural microbial communities and the capacity of exposed communities to oxidize As(III) has not been well explored. In this study, we conducted soil column experiments with a natural microbial community exposed to different carbon conditions and a continuous flow of As(III). We measured the oxidation rates of As(III) to As(V), and the composition of the bacterial community was monitored by 454 pyrosequencing of 16S rRNA genes. The diversity of As(III)-oxidizing bacteria was examined with the aox gene, which encodes the enzyme involved in As(III) oxidation. Arsenite oxidation was high in the live soil regardless of the carbon source and below detection in sterilized soil. In columns amended with 200 μmol kg(-1) of As (III), As(V) concentrations reached 158 μmol kg(-1) in the column effluent, while As(III) decreased to unmeasurable levels. Although the number of bacterial taxa decreased by as much as twofold in treatments amended with As(III), some As(III)-oxidizing bacterial groups increased up to 20-fold. Collectively, the data show the large effect of As(III) on bacterial diversity, and the capacity of natural communities from a soil with low initial As contamination to oxidize large inputs of As(III).

  3. Isolation and Identification of Concrete Environment Bacteria

    NASA Astrophysics Data System (ADS)

    Irwan, J. M.; Anneza, L. H.; Othman, N.; Husnul, T.; Alshalif, A. F.

    2016-07-01

    This paper presents the isolation and molecular method for bacteria identification through PCR and DNA sequencing. Identification of the bacteria species is required in order to fully utilize the bacterium capability for precipitation of calcium carbonate in concrete. This process is to enable the addition of suitable catalyst according to the bacterium enzymatic pathway that is known through the bacteria species used. The objective of this study is to isolate, enriched and identify the bacteria species. The bacteria in this study was isolated from fresh urine and acid mine drainage water, Kota Tinggi, Johor. Enrichment of the isolated bacteria was conducted to ensure the bacteria survivability in concrete. The identification of bacteria species was done through polymerase chain reaction (PCR) and rRDNA sequencing. The isolation and enrichment of the bacteria was done successfully. Whereas, the results for bacteria identification showed that the isolated bacteria strains are Bacillus sp and Enterococus faecalis.

  4. Anaerobic arsenite oxidation by an autotrophic arsenite-oxidizing bacterium from an arsenic-contaminated paddy soil.

    PubMed

    Zhang, Jun; Zhou, Wuxian; Liu, Bingbing; He, Jian; Shen, Qirong; Zhao, Fang-Jie

    2015-05-19

    Microbe-mediated arsenic (As) redox reactions play an important role in the biogeochemical cycling of As. Reduction of arsenate [As(V)] generally leads to As mobilization in paddy soils and increased As availability to rice plants, whereas oxidation of arsenite [As(III)] results in As immobilization. A novel chemoautotrophic As(III)-oxidizing bacterium, designated strain SY, was isolated from an As-contaminated paddy soil. The isolate was able to derive energy from the oxidation of As(III) to As(V) under both aerobic and anaerobic conditions using O2 or NO3(-) as the respective electron acceptor. Inoculation of the washed SY cells into a flooded soil greatly enhanced As(III) oxidation to As(V) both in the solution and adsorbed phases of the soil. Strain SY is phylogenetically closely related to Paracoccus niistensis with a 16S rRNA gene similarity of 96.79%. The isolate contains both the denitrification and ribulose 1,5-bisphosphate carboxylase/oxygenase gene clusters, underscoring its ability to denitrify and to fix CO2 while coupled to As(III) oxidation. Deletion of the aioA gene encoding the As(III) oxidase subunit A abolished the As(III) oxidation ability of strain SY and led to increased sensitivity to As(III), suggesting that As(III) oxidation is a detoxification mechanism in this bacterium under aerobic and heterotrophic growth conditions. Analysis of the aioA gene clone library revealed that the majority of the As(III)-oxidizing bacteria in the soil were closely related to the genera Paracoccus of α-Proteobacteria. Our results provide direct evidence for As(III) oxidation by Paracoccus species and suggest that these species may play an important role in As(III) oxidation in paddy soils under both aerobic and denitrifying conditions. PMID:25905768

  5. Anaerobic oxidation of arsenite in Mono Lake water and by a facultative, arsenite-oxidizing chemoautotroph, strain MLHE-1

    USGS Publications Warehouse

    Oremland, R.S.; Hoeft, S.E.; Santini, J.M.; Bano, N.; Hollibaugh, R.A.; Hollibaugh, J.T.

    2002-01-01

    Arsenite [As(III)]-enriched anoxic bottom water from Mono Lake, California, produced arsenate [As(V)] during incubation with either nitrate or nitrite. No such oxidation occurred in killed controls or in live samples incubated without added nitrate or nitrite. A small amount of biological As(III) oxidation was observed in samples amended with Fe(III) chelated with nitrolotriacetic acid, although some chemical oxidation was also evident in killed controls. A pure culture, strain MLHE-1, that was capable of growth with As(III) as its electron donor and nitrate as its electron acceptor was isolated in a defined mineral salts medium. Cells were also able to grow in nitrate-mineral salts medium by using H2 or sulfide as their electron donor in lieu of As(III). Arsenite-grown cells demonstrated dark 14CO2 fixation, and PCR was used to indicate the presence of a gene encoding ribulose-1,5-biphosphate carboxylase/oxygenase. Strain MLHE-1 is a facultative chemoautotroph, able to grow with these inorganic electron donors and nitrate as its electron acceptor, but heterotrophic growth on acetate was also observed under both aerobic and anaerobic (nitrate) conditions. Phylogenetic analysis of its 16S ribosomal DNA sequence placed strain MLHE-1 within the haloalkaliphilic Ectothiorhodospira of the ??-Proteobacteria. Arsenite oxidation has never been reported for any members of this subgroup of the Proteobacteria.

  6. Bacteria-induced sexual isolation in Drosophila.

    PubMed

    Ringo, John; Sharon, Gil; Segal, Daniel

    2011-01-01

    Commensal bacteria can induce sexual isolation between populations of Drosophila. This phenomenon has implications for speciation, and raises questions about its behavioral and developmental mechanisms, which are not yet known. In this Extra View, we discuss related work by others, bearing directly on these issues, and we speculate about how bacteria might influence fly behavior. There are many reports of interaction between Drosophila and their microbiota that significantly impacts mating preferences. Sexual isolation can be enhanced or reduced by altering the culture media, or the microbiota inhabiting those media. More dramatically, the endoparasite Wolbachia has induced strong mate preferences in some instances. While a sudden, ecologically induced shift in mating preferences falls far short of the changes required for speciation, it might be a first step in that direction. We hypothesize that bacteria-induced sexual isolation is caused by chemosensory cues. In our experiments, bacteria altered the profile of cuticular hydrocarbons, which function as sex pheromones. Commensal bacteria may act directly on these hydrocarbons, or they may affect their synthesis. Alternatively, bacterial metabolites might perfume the flies in ways that affect mate choice. In that event, habituation or conditioning likely plays a role.

  7. Isolation of methanotrophic bacteria from termite gut.

    PubMed

    Reuss, Julia; Rachel, Reinhard; Kämpfer, Peter; Rabenstein, Andreas; Küver, Jan; Dröge, Stefan; König, Helmut

    2015-10-01

    The guts of termites feature suitable conditions for methane oxidizing bacteria (MOB) with their permanent production of CH4 and constant supply of O2 via tracheae. In this study, we have isolated MOB from the gut contents of the termites Incisitermes marginipennis, Mastotermes darwiniensis, and Neotermes castaneus for the first time. The existence of MOB was indicated by detecting pmoA, the gene for the particulate methane monooxygenase, in the DNA of gut contents. Fluorescence in situ hybridization and quantitative real-time polymerase chain reaction supported those findings. The MOB cell titer was determined to be 10(2)-10(3) per gut. Analyses of the 16S rDNA from isolates indicated close similarity to the genus Methylocystis. After various physiological tests and fingerprinting methods, no exact match to a known species was obtained, indicating the isolation of new MOB species. However, MALDI-TOF MS analyses revealed a close relationship to Methylocystis bryophila and Methylocystis parvus.

  8. The predominant bacteria isolated from radicular cysts

    PubMed Central

    2013-01-01

    Purpose To detect predominant bacteria associated with radicular cysts and discuss in light of the literature. Material and methods Clinical materials were obtained from 35 radicular cysts by aspiration. Cultures were made from clinical materials by modern laboratory techniques, they underwent microbiologic analysis. Results The following are microorganisms isolated from cultures: Streptococcus milleri Group (SMG) (23.8%) [Streptococcus constellatus (19.1%) and Streptococcus anginosus (4.7%)], Streptococcus sanguis (14.3%), Streptococcus mitis (4.7%), Streptococcus cremoris (4.7%), Peptostreptococcus pevotii (4.7%), Prevotella buccae (4.7%), Prevotella intermedia (4.7%), Actinomyces meyeri (4.7%), Actinomyces viscosus (4.7%), Propionibacterium propionicum (4.7%), Bacteroides capillosus (4.7%), Staphylococcus hominis (4.7%), Rothia denticariosa (4.7%), Gemella haemolysans (4.7%), and Fusobacterium nucleatum (4.7%). Conclusions Results of this study demonstrated that radicular cysts show a great variety of anaerobic and facultative anaerobic bacterial flora. It was observed that all isolated microorganisms were the types commonly found in oral flora. Although no specific microorganism was found, Streptococcus spp. bacteria (47.5%) – especially SMG (23.8%) – were predominantly found in the microorganisms isolated. Furthermore, radicular cysts might be polymicrobial originated. Although radicular cyst is an inflammatory cyst, some radicular cyst fluids might be sterile. PMID:24011184

  9. Isolation of methanotrophic bacteria from termite gut.

    PubMed

    Reuss, Julia; Rachel, Reinhard; Kämpfer, Peter; Rabenstein, Andreas; Küver, Jan; Dröge, Stefan; König, Helmut

    2015-10-01

    The guts of termites feature suitable conditions for methane oxidizing bacteria (MOB) with their permanent production of CH4 and constant supply of O2 via tracheae. In this study, we have isolated MOB from the gut contents of the termites Incisitermes marginipennis, Mastotermes darwiniensis, and Neotermes castaneus for the first time. The existence of MOB was indicated by detecting pmoA, the gene for the particulate methane monooxygenase, in the DNA of gut contents. Fluorescence in situ hybridization and quantitative real-time polymerase chain reaction supported those findings. The MOB cell titer was determined to be 10(2)-10(3) per gut. Analyses of the 16S rDNA from isolates indicated close similarity to the genus Methylocystis. After various physiological tests and fingerprinting methods, no exact match to a known species was obtained, indicating the isolation of new MOB species. However, MALDI-TOF MS analyses revealed a close relationship to Methylocystis bryophila and Methylocystis parvus. PMID:26411892

  10. Isolation and characterization of novel chitinolytic bacteria

    NASA Astrophysics Data System (ADS)

    Gürkök, Sümeyra; Görmez, Arzu

    2016-04-01

    Chitin, a linear polymer of β-1,4-N-acetylglucosamine units, is one of the most abundant biopolymers widely distributed in the marine and terrestrial environments. It is found as a structural component of insects, crustaceans and the cell walls of fungi. Chitinases, the enzymes degrading chitin by cleaving the β-(1-4) bond, have gained increased attention due to their wide range of biotechnological applications, especially for biocontrol of harmful insects and phytopathogenic fungi in agriculture. In the present study, 200 bacterial isolates from Western Anatolia Region of Turkey were screened for chitinolytic activity on agar media amended with colloidal chitin. Based on the chitin hydrolysis zone, 13 isolates were selected for further study. Bacterial isolates with the highest chitinase activity were identified as Acinetobacter calcoaceticus, Arthrobacter oxydans, Bacillus cereus, Bacillus megaterium, Brevibacillus reuszeri, Kocuria erythromyxa, Kocuria rosea, Novosphingobium capsulatum, Rhodococcus bratislaviensis, Rhodococcus fascians and Staphylococcus cohnii by MIS and BIOLOG systems. The next aims of the study are to compare the productivity of these bacteria quantitatively, to purify the enzyme from the most potent producer and to apply the pure enzyme for the fight against the phytopathogenic fungi and harmful insects.

  11. Mutations and Misconceptions: The Isolation and Study of Mutant Bacteria.

    ERIC Educational Resources Information Center

    Corner, Thomas R.

    1992-01-01

    Describes simple, inexpensive activities for teaching students about mutants and mutations in bacteria. Explains how to isolate bacteria from soil and leaves and how to grow bacteria on agar or in broth. Describes how to construct a gradient plate for finding the minimum inhibitory concentration of a substance and how to use this set up to find…

  12. Isolation of oxalotrophic bacteria able to disperse on fungal mycelium.

    PubMed

    Bravo, Daniel; Cailleau, Guillaume; Bindschedler, Saskia; Simon, Anaele; Job, Daniel; Verrecchia, Eric; Junier, Pilar

    2013-11-01

    A technique based on an inverted Petri dish system was developed for the growth and isolation of soil oxalotrophic bacteria able to disperse on fungal mycelia. The method is related to the 'fungal highways' dispersion theory in which mycelial fungal networks allow active movement of bacteria in soil. Quantification of this phenomenon showed that bacterial dispersal occurs preferentially in upper soil horizons. Eight bacteria and one fungal strain were isolated by this method. The oxalotrophic activity of the isolated bacteria was confirmed through calcium oxalate dissolution in solid selective medium. After separation of the bacteria-fungus couple, partial sequencing of the 16S and the ITS1 and ITS2 sequences of the ribosomal RNA genes were used for the identification of bacteria and the associated fungus. The isolated oxalotrophic bacteria included strains related to Stenotrophomonas, Achromobacter, Lysobacter, Pseudomonas, Agrobacterium, Cohnella, and Variovorax. The recovered fungus corresponded to Trichoderma sp. A test carried out to verify bacterial transport in an unsaturated medium showed that all the isolated bacteria were able to migrate on Trichoderma hyphae or glass fibers to re-colonize an oxalate-rich medium. The results highlight the importance of fungus-driven bacterial dispersal to understand the functional role of oxalotrophic bacteria and fungi in soils. PMID:24106816

  13. Isolation of fucosyltransferase-producing bacteria from marine environments.

    PubMed

    Kajiwara, Hitomi; Toda, Munetoyo; Mine, Toshiki; Nakada, Hiroshi; Yamamoto, Takeshi

    2012-01-01

    Fucose-containing oligosaccharides on the cell surface of some pathogenic bacteria are thought to be important for host-microbe interactions and to play a major role in the pathogenicity of bacterial pathogens. Here, we screened marine bacteria for glycosyltransferases using two methods: a one-pot glycosyltransferase assay method and a lectin-staining method. Using this approach, we isolated marine bacteria with fucosyltransferase activity. There have been no previous reports of marine bacteria producing fucosyltransferase. This paper thus represents the first report of fucosyltransferase-producing marine bacteria.

  14. Isolation and characterization of methanogenic bacteria from landfills

    SciTech Connect

    Fielding, E.R.; Archer, D.B.; De Macario, E.C.; Macario, A.J.L.

    1988-03-01

    Methanogenic bacteria were isolated from landfill sites in the United Kindgom. Strains of Methanobacterium formicicum, Methanosarcina barkeri, several different immunotypes of Methanobacterium bryantii, and a coccoid methanogen distinct from the reference immunotypes were identified.

  15. VIRULENCE CHARACTERISTICS OF HETEROTROPHIC BACTERIA COMMONLY ISOLATED FROM POTABLE WATER

    EPA Science Inventory

    Heterotrophic bacteria isolated from drinking water distribution systems were examined to determine if they possessed putative virulence factors such as hemolysins, proteases, or cytotoxins. Representative samples of colonies from several different distribution systems indicated ...

  16. Isolation of carbohydrate-metabolizing, extremely halophilic bacteria.

    NASA Technical Reports Server (NTRS)

    Tomlinson, G. A.; Hochstein, L. I.

    1972-01-01

    Four previously unrecognized strains of extremely halophilic bacteria that utilize carbohydrates have been isolated. Gas production proved an unreliable index of carbohydrate metabolism; therefore, carbohydrate utilization was measured by determining acid formation and sugar disappearance during growth. By these procedures, carbohydrate utilization was readily detected. The results suggest that carbohydrate dissimilation by extremely halophilic bacteria may be more common than previously thought and that the apparent rarity of carbohydrate-metabolizing halophiles may be an artifact of the isolation procedures used.

  17. [Isolation and determination of silver-resistant bacteria plasmids].

    PubMed

    Li, Junmin; Jin, Zexin

    2006-02-01

    Through the enrichment of the active mud obtained from three chemical plants and the domestication with different concentration Ag+ solution, thirty bacteria strains with silver (Ag+)-resistance were isolated, among which, the highest Ag+ -resistant concentration was 80 mg x ml(-1). The plasmids in these bacteria were extracted, with the detection rate of 76.67%. The elimination rate of the plasmid in HAg4 bacteria was 98.75% by 40 mmol x L(-1) sodium benzoate, and 77.78% by 350 microg x ml(-1) acridine orange. It was suggested that the Ag+ -resistance of bacteria was highly correlated with their plasmids.

  18. Isolation of fiber degrading bacteria from pig feces

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to better understand fiber digestion in the pig, two types of selective enrichments to isolate cellulose, xylan and pectin utilizing bacteria, were used. Rapid flow isolations utilized a chemostat with a flow rate of 25%/h combined with substrate immobilized in Dacron bags. Substrate depl...

  19. Isolation and characterization of pigmented algicidal bacteria from seawater

    NASA Astrophysics Data System (ADS)

    Shaima, A.; Gires, U.; Asmat, A.

    2014-09-01

    Some dinoflagellate species are toxic and widely distributed in Malaysian marines ecosystems. They can cause many problems to aquatic life due to the production of various potential and natural toxins that accumulate in filter feeding shellfish and cause food poisoning to human. In recent decades, bacteria have been widely used as a biological control against these harmful algae. In the present study, pigmented bacteria isolated from marine water of Port Dickson beach was studied for their anti-algal activity towards toxic dinoflagellate Alexandrium minutum. Four isolates were studied and only one was capable of inhibiting algal growth when treated with bacterial culture. The algilytic effect on dinoflagellate was evaluated based on direct cell count under the microscope. Results showed that only isolate Sdpd-310 with orange colour has an inhibitory effect on A. minutum growth. This study demonstrated the rapid algicidal activity of a marine pigmented bacteria against the toxic dinoflagellate A. minutum.

  20. Effect of arsenite-oxidizing bacterium B. laterosporus on arsenite toxicity and arsenic translocation in rice seedlings.

    PubMed

    Yang, Gui-Di; Xie, Wan-Ying; Zhu, Xi; Huang, Yi; Yang, Xiao-Jun; Qiu, Zong-Qing; Lv, Zhen-Mao; Wang, Wen-Na; Lin, Wen-Xiong

    2015-10-01

    Arsenite [As (III)] oxidation can be accelerated by bacterial catalysis, but the effects of the accelerated oxidation on arsenic toxicity and translocation in rice plants are poorly understood. Herein we investigated how an arsenite-oxidizing bacterium, namely Brevibacillus laterosporus, influences As (III) toxicity and translocation in rice plants. Rice seedlings of four cultivars, namely Guangyou Ming 118 (GM), Teyou Hang II (TH), Shanyou 63 (SY) and Minghui 63 (MH), inoculated with or without the bacterium were grown hydroponically with As (III) to investigate its effects on arsenic toxicity and translocation in the plants. Percentages of As (III) oxidation in the solutions with the bacterium (100%) were all significantly higher than those without (30-72%). The addition of the bacterium significantly decreased As (III) concentrations in SY root, GM root and shoot, while increased the As (III) concentrations in the shoot of SY, MH and TH and in the root of MH. Furthermore, the As (III) concentrations in the root and shoot of SY were both the lowest among the treatments with the bacterium. On the other hand, its addition significantly alleviated the As (III) toxicity on four rice cultivars. Among the treatments amended with B. laterosporus, the bacterium showed the best remediation on SY seedlings, with respect to the subdued As (III) toxicity and decreased As (III) concentration in its roots. These results indicated that As (III) oxidation accelerated by B. laterosporus could be an effective method to alleviate As (III) toxicity on rice seedlings. PMID:26024808

  1. Effect of arsenite-oxidizing bacterium B. laterosporus on arsenite toxicity and arsenic translocation in rice seedlings.

    PubMed

    Yang, Gui-Di; Xie, Wan-Ying; Zhu, Xi; Huang, Yi; Yang, Xiao-Jun; Qiu, Zong-Qing; Lv, Zhen-Mao; Wang, Wen-Na; Lin, Wen-Xiong

    2015-10-01

    Arsenite [As (III)] oxidation can be accelerated by bacterial catalysis, but the effects of the accelerated oxidation on arsenic toxicity and translocation in rice plants are poorly understood. Herein we investigated how an arsenite-oxidizing bacterium, namely Brevibacillus laterosporus, influences As (III) toxicity and translocation in rice plants. Rice seedlings of four cultivars, namely Guangyou Ming 118 (GM), Teyou Hang II (TH), Shanyou 63 (SY) and Minghui 63 (MH), inoculated with or without the bacterium were grown hydroponically with As (III) to investigate its effects on arsenic toxicity and translocation in the plants. Percentages of As (III) oxidation in the solutions with the bacterium (100%) were all significantly higher than those without (30-72%). The addition of the bacterium significantly decreased As (III) concentrations in SY root, GM root and shoot, while increased the As (III) concentrations in the shoot of SY, MH and TH and in the root of MH. Furthermore, the As (III) concentrations in the root and shoot of SY were both the lowest among the treatments with the bacterium. On the other hand, its addition significantly alleviated the As (III) toxicity on four rice cultivars. Among the treatments amended with B. laterosporus, the bacterium showed the best remediation on SY seedlings, with respect to the subdued As (III) toxicity and decreased As (III) concentration in its roots. These results indicated that As (III) oxidation accelerated by B. laterosporus could be an effective method to alleviate As (III) toxicity on rice seedlings.

  2. Isolation of Vermamoeba vermiformis and associated bacteria in hospital water.

    PubMed

    Pagnier, Isabelle; Valles, Camille; Raoult, Didier; La Scola, Bernard

    2015-03-01

    To detect new potential pathogens in hospital water, we isolated free-living amoebae in water samples taken from three different hospitals in Marseille (France). The samples were inoculated in media containing saline buffer and various bacteria as nutrient sources. The isolated amoebae were identified by gene sequencing. Among the 105 water samples, taken from 19 sites, we isolated 14 amoebae, of which 9 Vermamoeba vermiformis and 5 Acanthamoeba sp. None of the amoebae showed the presence of obligate bacterial endosymbionts. Because V. vermiformis was most commonly isolated, we used an axenic collection strain to isolate amoeba-resistant bacteria from the same sites. The isolated bacterial species included Stenotrophomonas maltophilia and Legionella sp. Legionella taurinensis was isolated for the first time in association with amoebae. A strict intracellular bacterium was isolated, that may represent a new genus among the Chlamydiales. We propose that it be named "Candidatus Rubidus massiliensis". Our study shows that the isolation and identification of new pathogens associated with amoebae, which were previously performed using Acanthamoeba sp., should instead use V. vermiformis because this organism is more commonly associated with humans and is an essential complement of Acanthamoeba sp. co-culture to study the ecology of hospital water supplies. PMID:25697664

  3. Triclosan-resistant bacteria isolated from feedlot and residential soils.

    PubMed

    Welsch, Tanner T; Gillock, Eric T

    2011-01-01

    Triclosan is an antimicrobial agent that is currently incorporated into hundreds of consumer and medical products. It can be either a bacteriostatic or bactericidal agent, depending on its formulation. It has activity against Gram-positive and Gram-negative bacteria, as well as some viruses and protists. The purpose of this study was to determine whether triclosan-resistant bacteria could be isolated from the soil. Soils from cattle feedlots and residential lawns were collected and assayed for the presence of these organisms by plating samples on growth media containing triclosan. Organisms were subsequently identified by partial 16S rRNA sequencing analysis. All the organisms isolated in this study were Gram-negative rods, with members of genus Pseudomonas being particularly well represented. This result may not be surprising because Gram-negative organisms are generally more resistant to triclosan, and since Pseudomonas bacteria are known to have numerous efflux mechanisms for dealing with harmful substances.

  4. Isolation and identification of bacteria from spent nuclear fuel pools.

    PubMed

    Chicote, Eduardo; García, Ana M; Moreno, Diego A; Sarró, M Isabel; Lorenzo, Petra I; Montero, Felipe

    2005-04-01

    The aim of the present research was to isolate and identify bacteria from spent nuclear fuel pools of a Spanish nuclear power plant. Water samples were collected and inoculated onto different culture media to isolate the highest number of species. 16S rDNA fragments from colonies growing on solid media were amplified and analysed by denaturing gradient gel electrophoresis. Sequencing revealed the presence of 21 different bacteria belonging to several phylogenetic groups (alpha, beta, and gamma-Proteobacteria, Actinomycetales, Flavobacterium, and the Bacillus/Staphylococcus group). The isolation of these microorganisms in this particular environment (oligotrophic and radioactive) is highly interesting because of the possibility of their being used for the bioremediation of radionuclide-contaminated waters.

  5. Isolation of naphthalene-degrading bacteria from tropical marine sediments.

    PubMed

    Zhuang, W Q; Tay, J H; Maszenan, A M; Tay, S T L

    2003-01-01

    Oil pollution is a major environmental concern in many countries, and this has led to a concerted effort in studying the feasibility of using oil-degrading bacteria for bioremediation. Although many oil-degrading bacteria have been isolated from different environments, environmental conditions can impose a selection pressure on the types of bacteria that can reside in a particular environment. This study reports the successful isolation of two indigenous naphthalene-degrading bacteria from oil-contaminated tropical marine sediments by enrichment culture. Strains MN-005 and MN-006 were characterized using an extensive range of biochemical tests. The 16S ribosomal deoxyribonucleic acid (rDNA) sequence analysis was also performed for the two strains. Their naphthalene degradation capabilities were determined using gas chromatography and DAPI counting of bacterial cells. Strains MN-005 and MN-006 are phenotypically and phylogenetically different from each other, and belong to the genera Staphylococcus and Micrococcus, respectively. Strains MN-005 and MN-006 had maximal specific growth rates (micro(max)) of 0.082 +/- 0.008 and 0.30 +/- 0.02 per hour, respectively, and half-saturation constants (K(s)) of 0.79 +/- 0.10 and 2.52 +/- 0.32 mg per litre, respectively. These physiological and growth studies are useful in assessing the potential of these indigenous isolates for in situ or ex situ naphthalene pollutant bioremediation in tropical marine environments.

  6. Optimization of Cellulase Production from Bacteria Isolated from Soil

    PubMed Central

    Sethi, Sonia; Datta, Aparna; Gupta, B. Lal; Gupta, Saksham

    2013-01-01

    Cellulase-producing bacteria were isolated from soil and identified as Pseudomonas fluorescens, Bacillus subtilIs, E. coli, and Serratia marcescens. Optimization of the fermentation medium for maximum cellulase production was carried out. The culture conditions like pH, temperature, carbon sources, and nitrogen sources were optimized. The optimum conditions found for cellulase production were 40°C at pH 10 with glucose as carbon source and ammonium sulphate as nitrogen source, and coconut cake stimulates the production of cellulase. Among bacteria, Pseudomonas fluorescens is the best cellulase producer among the four followed by Bacillus subtilis, E. coli, and Serratia marscens. PMID:25937986

  7. Antibiotic resistance of lactic acid bacteria isolated from Chinese yogurts.

    PubMed

    Zhou, N; Zhang, J X; Fan, M T; Wang, J; Guo, G; Wei, X Y

    2012-09-01

    The aim of this study was to evaluate the susceptibility of 43 strains of lactic acid bacteria, isolated from Chinese yogurts made in different geographical areas, to 11 antibiotics (ampicillin, penicillin G, roxithromycin, chloramphenicol, tetracycline, chlortetracycline, lincomycin, kanamycin, streptomycin, neomycin, and gentamycin). The 43 isolates (18 Lactobacillus bulgaricus and 25 Streptococcus thermophilus) were identified at species level and were typed by random amplified polymorphic DNA analysis. Thirty-five genotypically different strains were detected and their antimicrobial resistance to 11 antibiotics was determined using the agar dilution method. Widespread resistance to ampicillin, chloramphenicol, chlortetracycline, tetracyclines, lincomycin, streptomycin, neomycin, and gentamycin was found among the 35 strains tested. All of the Strep. thermophilus strains tested were susceptible to penicillin G and roxithromycin, whereas 23.5 and 64.7% of Lb. bulgaricus strains, respectively, were resistant. All of the Strep. thermophilus and Lb. bulgaricus strains were found to be resistant to kanamycin. The presence of the corresponding resistance genes in the resistant isolates was investigated through PCR, with the following genes detected: tet(M) in 1 Lb. bulgaricus and 2 Strep. thermophilus isolates, ant(6) in 2 Lb. bulgaricus and 2 Strep. thermophilus isolates, and aph(3')-IIIa in 5 Lb. bulgaricus and 2 Strep. thermophilus isolates. The main threat associated with these bacteria is that they may transfer resistance genes to pathogenic bacteria, which has been a major cause of concern to human and animal health. To our knowledge, the aph(3')-IIIa and ant(6) genes were found in Lb. bulgaricus and Strep. thermophilus for the first time. Further investigations are required to analyze whether the genes identified in Lb. bulgaricus and Strep. thermophilus isolates might be horizontally transferred to other species.

  8. Screening and isolation of halophilic bacteria producing industrially important enzymes

    PubMed Central

    Kumar, Sumit; Karan, Ram; Kapoor, Sanjay; S.P., Singh; S.K., Khare

    2012-01-01

    Halophiles are excellent sources of enzymes that are not only salt stable but also can withstand and carry out reactions efficiently under extreme conditions. The aim of the study was to isolate and study the diversity among halophilic bacteria producing enzymes of industrial value. Screening of halophiles from various saline habitats of India led to isolation of 108 halophilic bacteria producing industrially important hydrolases (amylases, lipases and proteases). Characterization of 21 potential isolates by morphological, biochemical and 16S rRNA gene analysis found them related to Marinobacter, Virgibacillus, Halobacillus, Geomicrobium, Chromohalobacter, Oceanobacillus, Bacillus, Halomonas and Staphylococcus genera. They belonged to moderately halophilic group of bacteria exhibiting salt requirement in the range of 3–20%. There is significant diversity among halophiles from saline habitats of India. Preliminary characterization of crude hydrolases established them to be active and stable under more than one extreme condition of high salt, pH, temperature and presence of organic solvents. It is concluded that these halophilic isolates are not only diverse in phylogeny but also in their enzyme characteristics. Their enzymes may be potentially useful for catalysis under harsh operational conditions encountered in industrial processes. The solvent stability among halophilic enzymes seems a generic novel feature making them potentially useful in non-aqueous enzymology. PMID:24031991

  9. Screening and isolation of halophilic bacteria producing industrially important enzymes.

    PubMed

    Kumar, Sumit; Karan, Ram; Kapoor, Sanjay; S P, Singh; S K, Khare

    2012-10-01

    Halophiles are excellent sources of enzymes that are not only salt stable but also can withstand and carry out reactions efficiently under extreme conditions. The aim of the study was to isolate and study the diversity among halophilic bacteria producing enzymes of industrial value. Screening of halophiles from various saline habitats of India led to isolation of 108 halophilic bacteria producing industrially important hydrolases (amylases, lipases and proteases). Characterization of 21 potential isolates by morphological, biochemical and 16S rRNA gene analysis found them related to Marinobacter, Virgibacillus, Halobacillus, Geomicrobium, Chromohalobacter, Oceanobacillus, Bacillus, Halomonas and Staphylococcus genera. They belonged to moderately halophilic group of bacteria exhibiting salt requirement in the range of 3-20%. There is significant diversity among halophiles from saline habitats of India. Preliminary characterization of crude hydrolases established them to be active and stable under more than one extreme condition of high salt, pH, temperature and presence of organic solvents. It is concluded that these halophilic isolates are not only diverse in phylogeny but also in their enzyme characteristics. Their enzymes may be potentially useful for catalysis under harsh operational conditions encountered in industrial processes. The solvent stability among halophilic enzymes seems a generic novel feature making them potentially useful in non-aqueous enzymology. PMID:24031991

  10. Simultaneous arsenite oxidation and nitrate reduction at the electrodes of bioelectrochemical systems.

    PubMed

    Nguyen, Van Khanh; Park, Younghyun; Yu, Jaecheul; Lee, Taeho

    2016-10-01

    Arsenic and nitrate contaminations in the soil and groundwater have urged the scientific community to explore suitable technologies for treatment of both contaminants. This study reports, for the first time, a novel application of bioelectrochemical systems for coupling As detoxification at the anode and denitrification at the cathode. A similar As(III) oxidation efficiency was achieved when anode potential was controlled by a potentiostat or a direct current (DC) power supply. However, a slightly lower nitrate reduction rate was obtained in reactors using DC power supply during simultaneous operation of nitrate reduction and As(III) oxidation. Microbial community analysis by denaturing gradient gel electrophoresis indicated the presence of some autotrophic As(III)-oxidizing bacteria, including Achromobacter spp., Ensifer spp., and Sinorhizobium spp., that can flexibly switch their original metabolism of using oxygen as sole electron acceptor to a new metabolism mode of using solid-state anode as sole electron acceptor driving for As(III) oxidation under anaerobic conditions. Although further research is required for validating their applicability, bioelectrochemical systems represent a brilliant technology for remediation of groundwater contaminated with nitrate and/or arsenite. PMID:27438874

  11. Simultaneous arsenite oxidation and nitrate reduction at the electrodes of bioelectrochemical systems.

    PubMed

    Nguyen, Van Khanh; Park, Younghyun; Yu, Jaecheul; Lee, Taeho

    2016-10-01

    Arsenic and nitrate contaminations in the soil and groundwater have urged the scientific community to explore suitable technologies for treatment of both contaminants. This study reports, for the first time, a novel application of bioelectrochemical systems for coupling As detoxification at the anode and denitrification at the cathode. A similar As(III) oxidation efficiency was achieved when anode potential was controlled by a potentiostat or a direct current (DC) power supply. However, a slightly lower nitrate reduction rate was obtained in reactors using DC power supply during simultaneous operation of nitrate reduction and As(III) oxidation. Microbial community analysis by denaturing gradient gel electrophoresis indicated the presence of some autotrophic As(III)-oxidizing bacteria, including Achromobacter spp., Ensifer spp., and Sinorhizobium spp., that can flexibly switch their original metabolism of using oxygen as sole electron acceptor to a new metabolism mode of using solid-state anode as sole electron acceptor driving for As(III) oxidation under anaerobic conditions. Although further research is required for validating their applicability, bioelectrochemical systems represent a brilliant technology for remediation of groundwater contaminated with nitrate and/or arsenite.

  12. Characterization of anaerobic heterotrophic bacteria isolated from freshwater lake sediments.

    PubMed

    Molongoski, J J; Klug, M J

    1976-01-01

    Strict anaerobic culture techniques were used to quantitatively and qualitatively evaluate the anaerobic heterotrophic bacteria present at the sediment-water interface of hyperutrophic Wintergreen Lake (Augusta, Mich.). Anaerobic plate counts remained constant from March through December, 1973, ranging from 2.4 X 10(6) to 5.7 X 10(6) organisms/g (dry weight) of sediment. The isolatable bacteria represented a small percentage of the total microbial community, which was shown by direct microscopic counts to be 2.0 X 10'' organisms/g (dry weight) of sediment during June and July. Bacteria of the genus Clostridium dominated the isolates obtained, accounting for 71.8% of the 960 isolates examined. A single species, Clostridium bifermentens, comprised 47.7% of the total. Additional bacterial groups and the percentage in which they were isolated included: Streptococcus sp. (10.8%), unidentified curved rods (9.5%y, gram-positive nonsporing rods (5.6%), and motile gram-negative rods (1.9%). Temperature growth studies demonstrated the ability of all the isolates to grow at in situ sediment temperatures. Gas-liqid radiochromatography was used to determine the soluble metabolic end products from [U-14C]glucose and a U-14C-labeled amino acid mixture by representative sedimentary clostridial isolates and by natural sediment microbial communities. At in situ temperatures the natural sediment microflora produced soluble fermentative end products characteristic of those elaborated by the clostridial isolates tested. These results are considered strong presumptive evidence that clostridia are actively metabolizing in the sediments of Wintergreen Lake.

  13. Isolation and Characterization of Bacteria from Ancient Siberian Permafrost Sediment

    PubMed Central

    Zhang, De-Chao; Brouchkov, Anatoli; Griva, Gennady; Schinner, Franz; Margesin, Rosa

    2013-01-01

    In this study, we isolated and characterized bacterial strains from ancient (Neogene) permafrost sediment that was permanently frozen for 3.5 million years. The sampling site was located at Mammoth Mountain in the Aldan river valley in Central Yakutia in Eastern Siberia. Analysis of phospolipid fatty acids (PLFA) demonstrated the dominance of bacteria over fungi; the analysis of fatty acids specific for Gram-positive and Gram-negative bacteria revealed an approximately twofold higher amount of Gram-negative bacteria compared to Gram-positive bacteria. Direct microbial counts after natural permafrost enrichment showed the presence of (4.7 ± 1.5) × 108 cells g−1 sediment dry mass. Viable heterotrophic bacteria were found at 0 °C, 10 °C and 25 °C, but not at 37 °C. Spore-forming bacteria were not detected. Numbers of viable fungi were low and were only detected at 0 °C and 10 °C. Selected culturable bacterial isolates were identified as representatives of Arthrobacter phenanthrenivorans, Subtercola frigoramans and Glaciimonas immobilis. Representatives of each of these species were characterized with regard to their growth temperature range, their ability to grow on different media, to produce enzymes, to grow in the presence of NaCl, antibiotics, and heavy metals, and to degrade hydrocarbons. All strains could grow at −5 °C; the upper temperature limit for growth in liquid culture was 25 °C or 30 °C. Sensitivity to rich media, antibiotics, heavy metals, and salt increased when temperature decreased (20 °C > 10 °C > 1 °C). In spite of the ligninolytic activity of some strains, no biodegradation activity was detected. PMID:24832653

  14. Plasmid Mediated Antibiotic Resistance in Isolated Bacteria From Burned Patients

    PubMed Central

    Beige, Fahimeh; Baseri Salehi, Majid; Bahador, Nima; Mobasherzadeh, Sina

    2014-01-01

    Background: Nowadays, the treatment of burned patients is difficult because of the high frequency of infection with antibiotic resistance bacteria. Objectives: This study was conducted to evaluate the level of antibiotic resistance in Gram-negative bacteria and its relation with the existence of plasmid. Materials and Methods: The samples were collected from two hundred twenty hospitalized burned patients in Isfahan burn hospital during a three-month period (March 2012 to June 2012). The samples were isolated and the Gram-negative bacteria were identified using phenotypic method and API 20E System. Antibiotic susceptibility and plasmid profile were determined by standard Agar disc diffusion and plasmid spin column extraction methods. Results: Totally 117 Gram-negative bacteria were isolated, the most common were Pseudomonas aerugionsa (37.6%), P. fluorescens (25.6%), Acinetobacter baumanii (20/5%) and Klebsiella pneumoniae (7.6%), respectively. The isolates showed high frequency of antibiotic resistance against ceftazidime and co-amoxiclave (100%) and low frequency of antibiotic resistance against amikacin with (70%).The results indicated that 60% of the isolates harboured plasmid. On the other hand, the patients infected with A. baumanii and P. aeruginosa were cured (with 60% frequency) whereas, those infected with P. fluorescens were not cured. Hence, probably antibiotic resistance markers of A. baumanii and P. aeruginosa are plasmid mediated; however, P. fluorescens is chromosomally mediated. Conclusions: Based on our findings, P. aerugionsa is a major causative agent of wound infections and amikacin could be considered as a more effective antibiotic for treatment of the burned patients. PMID:25789121

  15. Arsenic transformation and mobilization from minerals by the arsenite oxidizing strain WAO

    USGS Publications Warehouse

    Rhine, E.D.; Onesios, K.M.; Serfes, M.E.; Reinfelder, J.R.; Young, L.Y.

    2008-01-01

    Analysis of arsenic concentrations in New Jersey well water from the Newark Basin showed up to 15% of the wells exceed 10 ??g L-1, with a maximum of 215 ??g L-1. In some geologic settings in the basin, this mobile arsenic could be from the weathering of pyrite (FeS2) found in black shale that contains up to 4% arsenic by weight. We hypothesized that under oxic conditions at circumneutral pH, the microbially mediated oxidation of sulfide in the pyrite lattice would lead to the release of pyrite-bound arsenic. Moreover, the oxidation of aqueous As(III) to As(V) by aerobic microorganisms could further enhance arsenic mobilization from the solid phase. Enrichment cultures under aerobic, As(III)-oxidizing conditions were established under circumneutral pH with weathered black shale from the Newark Basin as the inoculum source. Strain WAO, an autotrophic inorganic-sulfur and As(III)-oxidizer, was isolated and phylogenetically and physiologically characterized. Arsenic mobilization studies from arsenopyrite (FeAsS) mineral, conducted with strain WAO at circumneutral pH, showed microbially enhanced mobilization of arsenic and complete oxidation of released arsenic and sulfur to stoichiometric amounts of arsenate and sulfate. In addition, WAO preferentially colonized pyrite on the surface of arsenic-bearing, black shale thick sections. These findings support the hypothesis that microorganisms can directly mobilize and transform arsenic bound in mineral form at circumneutral pH and suggest that the microbial mobilization of arsenic into groundwater may be important in other arsenic-impacted aquifers. ?? 2008 American Chemical Society.

  16. Azoreductase activity of anaerobic bacteria isolated from human intestinal microflora.

    PubMed Central

    Rafii, F; Franklin, W; Cerniglia, C E

    1990-01-01

    A plate assay was developed for the detection of anaerobic bacteria that produce azoreductases. With this plate assay, 10 strains of anaerobic bacteria capable of reducing azo dyes were isolated from human feces and identified as Eubacterium hadrum (2 strains), Eubacterium spp. (2 species), Clostridium clostridiiforme, a Butyrivibrio sp., a Bacteroides sp., Clostridium paraputrificum, Clostridium nexile, and a Clostridium sp. The average rate of reduction of Direct Blue 15 dye (a dimethoxybenzidine-based dye) in these strains ranged from 16 to 135 nmol of dye per min per mg of protein. The enzymes were inactivated by oxygen. In seven isolates, a flavin compound (riboflavin, flavin adenine dinucleotide, or flavin mononucleotide) was required for azoreductase activity. In the other three isolates and in Clostridium perfringens, no added flavin was required for activity. Nondenaturing polyacrylamide gel electrophoresis showed that each bacterium expressed only one azoreductase isozyme. At least three types of azoreductase enzyme were produced by the different isolates. All of the azoreductases were produced constitutively and released extracellularly. Images PMID:2202258

  17. Diverse bacteria isolated from microtherm oil-production water.

    PubMed

    Sun, Ji-Quan; Xu, Lian; Zhang, Zhao; Li, Yan; Tang, Yue-Qin; Wu, Xiao-Lei

    2014-02-01

    In total, 435 pure bacterial strains were isolated from microtherm oil-production water from the Karamay Oilfield, Xinjiang, China, by using four media: oil-production water medium (Cai medium), oil-production water supplemented with mineral salt medium (CW medium), oil-production water supplemented with yeast extract medium (CY medium), and blood agar medium (X medium). The bacterial isolates were affiliated with 61 phylogenetic groups that belong to 32 genera in the phyla Actinobacteria, Firmicutes, and Proteobacteria. Except for the Rhizobium, Dietzia, and Pseudomonas strains that were isolated using all the four media, using different media led to the isolation of bacteria with different functions. Similarly, nonheme diiron alkane monooxygenase genes (alkB/alkM) also clustered according to the isolation medium. Among the bacterial strains, more than 24 % of the isolates could use n-hexadecane as the sole carbon source for growth. For the first time, the alkane-degrading ability and alkB/alkM were detected in Rhizobium, Rhodobacter, Trichococcus, Micrococcus, Enterococcus, and Bavariicoccus strains, and the alkM gene was detected in Firmicutes strains.

  18. Isolation and identification of bacteria by means of Raman spectroscopy.

    PubMed

    Pahlow, Susanne; Meisel, Susann; Cialla-May, Dana; Weber, Karina; Rösch, Petra; Popp, Jürgen

    2015-07-15

    Bacterial detection is a highly topical research area, because various fields of application will benefit from the progress being made. Consequently, new and innovative strategies which enable the investigation of complex samples, like body fluids or food stuff, and improvements regarding the limit of detection are of general interest. Within this review the prospects of Raman spectroscopy as a reliable tool for identifying bacteria in complex samples are discussed. The main emphasis of this work is on important aspects of applying Raman spectroscopy for the detection of bacteria like sample preparation and the identification process. Several approaches for a Raman compatible isolation of bacterial cells have been developed and applied to different matrices. Here, an overview of the limitations and possibilities of these methods is provided. Furthermore, the utilization of Raman spectroscopy for diagnostic purposes, food safety and environmental issues is discussed under a critical view. PMID:25895619

  19. Isolation and characterization of bacteria resistant to metallic copper surfaces.

    PubMed

    Santo, Christophe Espírito; Morais, Paula Vasconcelos; Grass, Gregor

    2010-03-01

    Metallic copper alloys have recently attracted attention as a new antimicrobial weapon for areas where surface hygiene is paramount. Currently it is not understood on a molecular level how metallic copper kills microbes, but previous studies have demonstrated that a wide variety of bacteria, including Escherichia coli, Staphylococcus aureus, and Clostridium difficile, are inactivated within minutes or a few hours of exposure. In this study, we show that bacteria isolated from copper alloy coins comprise strains that are especially resistant against the toxic properties exerted by dry metallic copper surfaces. The most resistant of 294 isolates were Gram-positive staphylococci and micrococci, Kocuria palustris, and Brachybacterium conglomeratum but also included the proteobacterial species Sphingomonas panni and Pseudomonas oleovorans. Cells of some of these bacterial strains survived on copper surfaces for 48 h or more. Remarkably, when these dry-surface-resistant strains were exposed to moist copper surfaces, resistance levels were close to those of control strains and MICs for copper ions were at or below control strain levels. This suggests that mechanisms conferring resistance against dry metallic copper surfaces in these newly isolated bacterial strains are different from well-characterized copper ion detoxification systems. Furthermore, staphylococci on coins did not exhibit increased levels of resistance to antibiotics, arguing against coselection with copper surface resistance traits. PMID:20048058

  20. Naturally Occurring Lactic Acid Bacteria Isolated from Tomato Pomace Silage

    PubMed Central

    Wu, Jing-jing; Du, Rui-ping; Gao, Min; Sui, Yao-qiang; Xiu, Lei; Wang, Xiao

    2014-01-01

    Silage making has become a significant method of forage conservation worldwide. To determine how tomato pomace (TP) may be used effectively as animal feed, it was ensilaged for 90 days and microbiology counts, fermentation characteristics and chemical composition of tomato pomace silage (TPS) were evaluated at the 30th, 60th, and 90th days, respectively. In addition, 103 lactic acid bacteria were isolated from TPS. Based on the phenotypic and chemotaxonomic characteristics, 16S rDNA sequence and carbohydrate fermentation tests, the isolates were identified as 17 species namely: Lactobacillus coryniformis subsp. torquens (0.97%), Lactobacillus pontis (0.97%), Lactobacillus hilgardii (0.97%), Lactobacillus pantheris (0.97%), Lactobacillus amylovorus (1.9%), Lactobacillus panis (1.9%), Lactobacillus vaginalis (1.9%), Lactobacillus rapi (1.9%), Lactobacillus buchneri (2.9%), Lactobacillus parafarraginis (2.9%), Lactobacillus helveticus (3.9%), Lactobacillus camelliae (3.9%), Lactobacillus fermentum (5.8%), Lactobacillus manihotivorans (6.8%), Lactobacillus plantarum (10.7%), Lactobacillus harbinensis (16.5%) and Lactobacillus paracasei subsp. paracasei (35.0%). This study has shown that TP can be well preserved for 90 days by ensilaging and that TPS is not only rich in essential nutrients, but that physiological and biochemical properties of the isolates could provide a platform for future design of lactic acid bacteria (LAB) inoculants aimed at improving the fermentation quality of silage. PMID:25049999

  1. Isolation and identification of novel geosmin-degrading bacteria.

    PubMed

    Xue, Qiang; Chen, Gang; Shimizu, Kazuya; Sakharkar, Meena Kishore; Utsumi, Motoo; Chen, Honghan; Li, Miao; Zhang, Zhenya; Sugiura, Norio

    2011-06-01

    Three novel geosmin-degrading bacteria were isolated from the sediments of Lake Kasumigaura, Japan. All strains were identified as Acinetobacter spp. by 16S rRNA gene sequence analysis and can biodegrade geosmin at an initial geosmin concentration of 2 mg/L after 2 days. Furthermore, at an initial geosmin concentration of 40 microg/L, geosmin removal was more than 68per cent by GSM-2 strain, and the degradation mechanism followed a pseudo-first-order mode. A rate constant of 0.026 reveals rapid geosmin degradation. This is the first report on geosmin degradation by by Acinetobacter spp.

  2. Isolation and characterization of endophytic bacteria isolated from the leaves of the common bean (Phaseolus vulgaris)

    PubMed Central

    de Oliveira Costa, Leonardo Emanuel; de Queiroz, Marisa Vieira; Borges, Arnaldo Chaer; de Moraes, Celia Alencar; de Araújo, Elza Fernandes

    2012-01-01

    The common bean is one of the most important legumes in the human diet, but little is known about the endophytic bacteria associated with the leaves of this plant. The objective of this study was to characterize the culturable endophytic bacteria of common bean (Phaseolus vulgaris) leaves from three different cultivars (Vermelhinho, Talismã, and Ouro Negro) grown under the same field conditions. The density of endophytic populations varied from 4.5 x 102 to 2.8 x 103 CFU g-1 of fresh weight. Of the 158 total isolates, 36.7% belonged to the Proteobacteria, 32.9% to Firmicutes, 29.7% to Actinobacteria, and 0.6% to Bacteroidetes. The three P. vulgaris cultivars showed class distribution differences among Actinobacteria, Alphaproteobacteria and Bacilli. Based on 16S rDNA sequences, 23 different genera were isolated comprising bacteria commonly associated with soil and plants. The genera Bacillus, Delftia, Methylobacterium, Microbacterium, Paenibacillus, Staphylococcus and Stenotrophomonas were isolated from all three cultivars. To access and compare the community structure, diversity indices were calculated. The isolates from the Talismã cultivar were less diverse than the isolates derived from the other two cultivars. The results of this work indicate that the cultivar of the plant may contribute to the structure of the endophytic community associated with the common bean. This is the first report of endophytic bacteria from the leaves of P. vulgaris cultivars. Future studies will determine the potential application of these isolates in biological control, growth promotion and enzyme production for biotechnology. PMID:24031988

  3. Isolation and identification of thermophilic and mesophylic proteolytic bacteria from shrimp paste "Terasi"

    NASA Astrophysics Data System (ADS)

    Murwani, R.; Supriyadi, Subagio, Trianto, A.; Ambariyanto

    2015-12-01

    Terasi is a traditional product generally made of fermented shrimp. There were many studies regarding lactic acid bacteria of terasi but none regarding proteolitic bacteria. This study was conducted to isolate and identify the thermophilic and mesophylic proteolytic bacteria from terasi. In addition, the effect of different salt concentrations on the growth of the isolated proteolytic bacteria with the greatest proteolytic activity was also studied. Terasi samples were obtained from the Northern coast region of Java island i.e. Jepara, Demak and Batang. The study obtained 34 proteolytic isolates. Four isolates were identified as Sulfidobacillus, three isolates as Vibrio / Alkaligenes / Aeromonas, two isolates as Pseudomonas, 21 isolates as Bacillus, three isolates as Kurthia/ Caryophanon and one isolates as Amphibacillus. The growth of proteolytic bacteria was affected by salt concentration. The largest growth was found at 0 ppm salt concentrations and growth was declined as salt concentration increased. Maximum growth at each salt concentration tested was found at 8 hours incubation.

  4. Alternative methodology for isolation of biosurfactant-producing bacteria.

    PubMed

    Krepsky, N; Da Silva, F S; Fontana, L F; Crapez, M A C

    2007-02-01

    Wide biosurfactant application on biorremediation is limited by its high production cost. The search for cheaper biossurfactant production alternatives has guided our study. The use of selective media containing sucrose (10 g x L(-1)) and Arabian Light oil (2 g x L(-1)) as carbon sources showed to be effective to screen and maintain biosurfactant-producing consortia isolated from mangrove hydrocarbon-contaminated sediment. The biosurfactant production was assayed by kerosene, gasoline and Arabian Light Emulsification activity and the bacterial growth curve was determined by bacterial quantification. The parameters analyzed for biosurfactant production were the growth curve, salinity concentration, flask shape and oxygenation. All bacteria consortia screened were able to emulsify the petroleum derivatives tested. Biosurfactant production increased according to the incubation time; however the type of emulsification (non-aqueous phase or aqueous phase) did not change with time but with the compound tested. The methodology was able to isolate biosurfactant-producing consortia from superficial mangrove sediment contaminated by petroleum hydrocarbons and was recommended for selection of biosurfactant producing bacteria in tropical countries with low financial resources.

  5. Isolation of iron bacteria from terrestrial and aquatic environments

    NASA Astrophysics Data System (ADS)

    Schmidt, Bertram; Szewzyk, Ulrich

    2010-05-01

    Bacteria, which are capable of iron oxidation or at least iron deposition are widely distributed in environments where zones of dissolved ferrous iron and oxygen gradients are overlapping [1]. They take part in the biological cycling of iron and influence other cycles of elements for example carbon [2]. Manganese can be used for similar metabolic purposes as iron, because it can be biologically oxidized by chemolithotrophs or can be reduced by respirating bacteria as well [3, 4]. Bacterial activity is responsible for the accumulation of ferric iron compounds in their surroundings. The formation of bog ore is a well known example for a soil horizon, with an extreme enrichment of biogenic ferric iron [5]. We focused on the isolation of neutrophilic iron bacteria and bacteria capable of manganese oxidation. We used samples from Tierra del Fuego (Argentina) the National Park "Unteres Odertal" (Germany) and Berlin ground water wells. Microscopic examination of the samples revealed a considerable diversity of iron encrusted structures of bacterial origin. Most of these morphologic types are already well known. The taxonomic classification of many of these organisms is based on morphologic features and is not reliable compared to recent methods of molecular biology. That is mainly due to the fact, that most of these bacteria are hardly culturable or do not show their characteristic morphologic features under culture conditions. We established a collection of more than 300 iron depositing strains. Phylogenetic analyses showed that we have many yet uncultured strains in pure culture. We obtained many isolates which form distinct branches within long known iron bacteria groups like the Sphaerotilus-Leptothrix cluster. But some of the strains belong to groups, which have not yet been associated with iron oxidation activity. The strains deposit high amounts of oxidized iron and manganese compounds under laboratory conditions. However it is unclear if these precipitations are

  6. Synergistic Effect of Photosynthetic Bacteria and Isolated Bacteria in Their Antifungal Activities against Root Rot Fungi.

    PubMed

    Wei, Hongyi; Okunishi, Suguru; Yoshikawa, Takeshi; Kamei, Yuto; Dawwoda, Mahmoud A O; Santander-DE Leon, Sheila Mae S; Nuñal, Sharon Nonato; Maeda, Hiroto

    2016-01-01

    Antifungal bacteria (AB) in root rot fungus (RRF)-contaminated sweet potato farms were isolated, and seven strains were initially chosen as antagonistic candidates. An antagonistic test by using the mycelial disk placement method revealed that one AB strain by itself could inhibit the RRF growth. This AB strain was identified as Bacillus polyfermenticus based on phylogeny of 16S ribosomal RNA genes. Two AB strains (Bacillus aerophilus) displayed high levels of antifungal activity when paired with photosynthetic bacterial strain A (a purple nonsulfur photosynthetic bacterium Rhodopseudomonas faecalis). The results suggest the possible use of the isolates as agents for the biological control of the RRF infection of agricultural products in fields of cultivation. PMID:27667522

  7. A MEMBRANE FILTER PROCEDURE FOR ASSAYING CYTOTOXIC ACTIVITY IN HETEROTROPHIC BACTERIA ISOLATED FROM DRINKING WATER

    EPA Science Inventory

    Cytotoxic activity assays of Gram-negative, heterotrophic bacteria are often laborious and time consuming. The objective of this study was to develop in situ procedures for testing potential cytotoxic activities of heterotrophic bacteria isolated from drinking water systems. Wate...

  8. Symbiotic root nodule bacteria isolated from yam bean (Pachyrhizus erosus).

    PubMed

    Fuentes, Jenet B; Abe, Mikiko; Uchiumi, Toshiki; Suzuki, Akihiro; Higashi, Shiro

    2002-08-01

    A total of 25 isolates from root nodules of yam bean (Pachyrhizus erosus L. Urban), a tuber-producing leguminous plant, were characterized. All isolates formed effective nodules mainly on lateral roots while edible tubers were developed on the taproot. The root nodules formed were identified as the typical determinate type. By an analysis of the partial sequences of the 16S rRNA gene (approximately 300 bp) of 10 strains which were selected randomly, the isolated root nodule bacteria of yam bean were classified into two different genera, Rhizobium and Bradyrhizobium. Two strains, YB2 (Bradyrhizobium group) and YB4 (Rhizobium group) were selected and used for further analyses. The generation time of each strain was shown to be 22.5 h for strain YB2 and 0.8 h for strain YB4, respectively. Differences between strains YB2 and YB4 were also reflected in the bacteroid state in the symbiosome. Symbiosome in nodule cells for the strain YB4 contained one bacteroid cell in a peribacteroid membrane, whereas a symbiosome for strain YB2 contained several bacteroid cells. PMID:12469317

  9. Acetic acid bacteria isolated from grapes of South Australian vineyards.

    PubMed

    Mateo, E; Torija, M J; Mas, A; Bartowsky, E J

    2014-05-16

    Acetic acid bacteria (AAB) diversity from healthy, mould-infected and rot-affected grapes collected from three vineyards of Adelaide Hills (South Australia) was analyzed by molecular typing and identification methods. Nine different AAB species were identified from the 624 isolates recovered: Four species from Gluconobacter genus, two from Asaia and one from Acetobacter were identified by the analysis of 16S rRNA gene and 16S-23S rRNA gene internal transcribed spacer. However, the identification of other isolates that were assigned as Asaia sp. and Ameyamaea chiangmaiensis required more analysis for a correct species classification. The species of Gluconobacter cerinus was the main one identified; while one genotype of Asaia siamensis presented the highest number of isolates. The number of colonies recovered and genotypes identified was strongly affected by the infection status of the grapes; the rot-affected with the highest number. However, the species diversity was similar in all the cases. High AAB diversity was detected with a specific genotype distribution for each vineyard.

  10. [Directed isolation of gram-negative asporogenous bacteria from natural substrates].

    PubMed

    Ivanitskaia, L P; Singal, E M; Bodunkova, L E; Ostanina, L N; Baturina, M V

    1984-10-01

    A method for selective isolation of gramnegative nonsporulating bacteria from soil substrates was developed. The method consists of plating out the substrates on a glucose-yeast medium with addition of benzylpenicillin and nalidixic acid. The isolation frequency of gramnegative nonsporulating bacteria increased under such conditions from 9-16 (control) to 80-100 per cent. At the same time the isolation frequency of gram-positive bacteria decreased from 88.5 to 9.6 per cent. PMID:6391365

  11. [Bacteria isolated from urine and renal tissue samples and their relation to renal histology].

    PubMed

    Gökalp, A; Gültekin, E Y; Bakici, M Z; Ozdeşlik, B

    1988-01-01

    The bacteria from the urine and renal biopsy specimens of 40 patients undergoing renal surgery were isolated and their relations with renal histology investigated. The urine cultures were positive in 14 patients, the same organisms being isolated from the renal tissue in 7 cases. In 6 patients with negative urine cultures, bacteria were isolated from renal tissues. Of the 28 cases pathologically diagnosed as chronic pyelonephritis, bacteria were isolated from the renal tissue in 13 cases, the urine cultures being positive in only 11 cases. E. coli was the most commonly encountered bacteria in both the urine and renal tissues.

  12. Piezophilic Bacteria Isolated from Sediment of the Shimokita Coalbed, Japan

    NASA Astrophysics Data System (ADS)

    Fang, J.; Kato, C.; Hori, T.; Morono, Y.; Inagaki, F.

    2013-12-01

    The Earth is a cold planet as well as pressured planet, hosting both the surface biosphere and the deep biosphere. Pressure ranges over four-orders of magnitude in the surface biosphere and probably more in the deep biosphere. Pressure is an important thermodynamic property of the deep biosphere that affects microbial physiology and biochemistry. Bacteria that require high-pressure conditions for optimal growth are called piezophilic bacteria. Subseafloor marine sediments are one of the most extensive microbial habitats on Earth. Marine sediments cover more than two-thirds of the Earth's surface, and represent a major part of the deep biosphere. Owing to its vast size and intimate connection with the surface biosphere, particularly the oceans, the deep biosphere has enormous potential for influencing global-scale biogeochemical processes, including energy, climate, carbon and nutrient cycles. Therefore, studying piezophilic bacteria of the deep biosphere has important implications in increasing our understanding of global biogeochemical cycles, the interactions between the biosphere and the geosphere, and the evolution of life. Sediment samples were obtained during IODP Expedition 337, from 1498 meters below sea floor (mbsf) (Sample 6R-3), 1951~1999 mbsf (19R-1~25R-3; coalbed mix), and 2406 mbsf (29R-7). The samples were mixed with MB2216 growth medium and cultivated under anaerobic conditions at 35 MPa (megapascal) pressure. Growth temperatures were adjusted to in situ environmental conditions, 35°C for 6R-3, 45°C for 19R-1~25R-3, and 55°C for 29R-7. The cultivation was performed three times, for 30 days each time. Microbial cells were obtained and the total DNA was extracted. At the same time, isolation of microbes was also performed under anaerobic conditions. Microbial communities in the coalbed sediment were analyzed by cloning, sequencing, and terminal restriction fragment length polymorphism (t-RFLP) of 16S ribosomal RNA genes. From the partial 16S r

  13. Hexavalent chromium-resistant bacteria isolated from river sediments.

    PubMed Central

    Luli, G W; Talnagi, J W; Strohl, W R; Pfister, R M

    1983-01-01

    Hexavalent chromium [Cr(VI)] is a known carcinogen and mutagen; however, the actual mechanisms of Cr toxicity are unknown. Two approaches were used to isolate Cr(VI)-resistant bacteria from metal-contaminated river sediments. Diluted sediments were plated directly onto a peptone-yeast extract (PYE) medium containing 0 to 100 micrograms of Cr(VI) ml-1. Approximately 8.4 x 10(5) CFU g-1 were recovered on 0 microgram of Cr(VI) ml-1, whereas 4.0 x 10(2) CFU g-1 were recovered on PYE plus 100 micrograms of Cr(VI) ml-1. Alternatively, continuous culture enrichment techniques were employed using PYE and 100 micrograms Cr(VI) ml-1 input at dilution rates of 0.02 and 0.10 h-1. After six residence periods, 10(9) CFU were recovered on PYE agar containing 0 microgram of Cr(VI) ml-1 and 10(7) CFU on PYE agar plus 100 micrograms of Cr(VI) ml-1. Of 89 isolates obtained by direct plating onto PYE, 47% were resistant to 100 micrograms of Cr(VI) ml-1, and 29% were resistant to 250 micrograms of Cr(VI) ml-1. When the same isolates were plated onto PYE containing Cr(III), 88% were resistant to 100 micrograms ml-1 but only 2% were resistant to 250 micrograms ml-1. Cr, Co, Sb, and Zn were found in significantly higher concentrations at an industry-related contaminated site than at a site 11 km downstream. Total Cr in the sediments at the contaminated site averaged 586 micrograms (dry weight) g-1, and the downstream site averaged 71 micrograms (dry weight) g-1. The Cr recovered from acid-digested Ottawa River sediment samples was predominantly hexavalent. Five acid digestion procedures followed by atomic absorption spectroscopy were compared and found to be 30 to 70% efficient for recovery of Cr relative to neutron activation analysis. A population of aerobic, heterotrophic bacteria was recovered from sediments containing elevated levels of Cr.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:6639032

  14. [Isolation identification and characterization of halotolerant petroleum-degrading bacteria].

    PubMed

    Wu, Tao; Xie, Wen-Jun; Yi, Yan-Li; Li, Xiao-Bin; Wang, Jun; Hu, Xiang-Ming

    2012-11-01

    To obtain efficient halotolerant petroleum-degrading bacteria, 39 bacteria strains were isolated from 30 petroleum contaminated saline soil samples in Yellow River Delta, an important base of petroleum production in China. One bacterium (strain BM38) was found to efficiently degrade crude oil in highly saline environments based on a series of liquid and soil incubation experiments. According to its morphology, physiochemical characteristics and 16S rDNA sequence analysis, this strain was identified as Pseudomonas putida. Moreover, a series of liquid incubation experiments were conducted to investigate its characteristics such as halotolerance, biosurfactants production and degrading efficiency for various hydrocarbons. The salt resistance test demonstrated that strain BM38 grew well at NaCl concentrations ranging from 0.5% to 6.0%. Petroleum degradation experiments showed that strain BM38 could degrade 73.5% crude oil after 7 days in a liquid culture medium containing 1.0% NaCl and remove more than 40% of total petroleum hydrocarbons after 40 days in the soil with 0.22% and 0.61% of salinity, these results proved that the strain was effective in removing petroleum hydrocarbons. Strain BM38 could produce a bioemulsifier in a liquid culture medium. The NaCl concentration had the significant effect on the EI24 of fermentation broth, which decreased sharply if the NaCl concentration was greater than 1.0%. However, the EI24 of BM38 was still quite high in the presence of 2.0% of NaCl, and the value was 61.0%. Furthermore, this strain was also able to grow in mineral liquid media amended with hexadecane, toluene, phenanthrene, isooctane and cyclohexane as the sole carbon sources. Among these hydracarbons, strain BM38 showed relatively high ability in degrading n-alkanes and aromatic hydracarbons. The results indicated that strain BM38 had potential for application in bioremediation of petroleum-contaminated saline soil.

  15. Methods of isolation and purification of outer membrane vesicles from gram-negative bacteria.

    PubMed

    Klimentová, Jana; Stulík, Jiří

    2015-01-01

    Outer membrane vesicles secreted by gram-negative bacteria play an important role in bacterial physiology as well as in virulence and host-pathogen interaction. Isolated vesicles of some bacteria have also been studied for their immunomodulatory potential in the vaccine development. However, the production of vesicles in sufficient amount, purity and reproducibility remains a critical challenge for subsequent analyses in most bacteria. In the present review methods of production, isolation, purification and quantification of outer membrane vesicles are summarized and discussed.

  16. Isolation and characterisation of lactic acid bacteria from donkey milk.

    PubMed

    Soto Del Rio, Maria de Los Dolores; Andrighetto, Christian; Dalmasso, Alessandra; Lombardi, Angiolella; Civera, Tiziana; Bottero, Maria Teresa

    2016-08-01

    During the last years the interest in donkey milk has increased significantly mainly because of its compelling functional elements. Even if the composition and nutritional properties of donkey milk are known, its microbiota is less studied. This Research Communication aimed to provide a comprehensive characterisation of the lactic acid bacteria in raw donkey milk. RAPD-PCR assay combined with 16S rDNA sequencing analysis were used to describe the microbial diversity of several donkey farms in the North West part of Italy. The more frequently detected species were: Lactobacillus paracasei, Lactococcus lactis and Carnobacterium maltaromaticum. Less abundant genera were Leuconostoc, Enterococcus and Streptococcus. The yeast Kluyveromyces marxianus was also isolated. The bacterial and biotype distribution notably diverged among the farms. Several of the found species, not previously detected in donkey milk, could have an important probiotic activity and biotechnological potential. This study represents an important insight to the ample diversity of the microorganisms present in the highly selective ecosystem of raw donkey milk. PMID:27600975

  17. Isolation and characterization of novel thermophilic lipase-secreting bacteria

    PubMed Central

    Rabbani, Mohammed; Bagherinejad, Mohammad Reza; Sadeghi, Hamid MirMohammad; Shariat, Ziaedin Samsam; Etemadifar, Zahra; Moazen, Fatemeh; Rahbari, Manizheh; Mafakher, Ladan; Zaghian, Saeideh

    2013-01-01

    The purpose of the present study was to screen and identify the lipase-producing microorganisms from various regions of Iran. Samples collected from hot spring, Persian Gulf, desert area and oil-contaminated soil, were analyzed for thermophilic extracellular-lipase producing organisms. Six strains with high activity on rhodamine B plates were selected for chemical identification and further study. Among these isolated bacteria, four strains show higher activity in pH-Stat method at 55 °C. These strains were identified by PCR amplification of 16s rRNA genes using universal primers. Fermentation increased the activity up to 50%. The growth medium, designed for lipase production, increased the activity up to 4.55 folds. The crude supernatant of ZR-5 after fermentation and separation the cells, was lyophilized and the activity was measured. Total activity of this strain was 12 kU/g that shows its potential for industrial uses. Further study is required for purification of enzyme and calculation its specific activity. Immobilization is another approach should be considered. PMID:24688500

  18. Isolation and characterization of novel thermophilic lipase-secreting bacteria.

    PubMed

    Rabbani, Mohammed; Bagherinejad, Mohammad Reza; Sadeghi, Hamid MirMohammad; Shariat, Ziaedin Samsam; Etemadifar, Zahra; Moazen, Fatemeh; Rahbari, Manizheh; Mafakher, Ladan; Zaghian, Saeideh

    2013-12-01

    The purpose of the present study was to screen and identify the lipase-producing microorganisms from various regions of Iran. Samples collected from hot spring, Persian Gulf, desert area and oil-contaminated soil, were analyzed for thermophilic extracellular-lipase producing organisms. Six strains with high activity on rhodamine B plates were selected for chemical identification and further study. Among these isolated bacteria, four strains show higher activity in pH-Stat method at 55 °C. These strains were identified by PCR amplification of 16s rRNA genes using universal primers. Fermentation increased the activity up to 50%. The growth medium, designed for lipase production, increased the activity up to 4.55 folds. The crude supernatant of ZR-5 after fermentation and separation the cells, was lyophilized and the activity was measured. Total activity of this strain was 12 kU/g that shows its potential for industrial uses. Further study is required for purification of enzyme and calculation its specific activity. Immobilization is another approach should be considered. PMID:24688500

  19. Isolation of lactic acid bacteria with potential protective culture characteristics from fruits

    NASA Astrophysics Data System (ADS)

    Hashim, Nurul Huda; Sani, Norrakiah Abdullah

    2015-09-01

    Lactic acid bacteria are also known as beneficial microorganisms abundantly found in fermented food products. In this study, lactic acid bacteria were isolated from fresh cut fruits obtained from local markets. Throughout the isolation process from 11 samples of fruits, 225 presumptive lactic acid bacteria were isolated on MRS agar medium. After catalase and oxidase tests, 149 resulted to fit the characteristics of lactic acid bacteria. Further identification using Gram staining was conducted to identify the Gram positive bacteria. After this confirmation, the fermentation characteristics of these isolates were identified. It was found that 87 (58.4%) isolates were heterofermentative, while the rest of 62 (41.6%) are homofermentative lactic acid bacteria. Later, all these isolates were investigated for the ability to inhibit growth of Staphylococcus aureus using agar spot assay method. Seven (4.7%) isolates showed strong antagonistic capacity, while 127 (85.2%) and 8 (5.4%) isolates have medium and weak antagonistic capacity, respectively. The other 7 (4.7%) isolates indicated to have no antagonistic effect on S. aureus. Results support the potential of LAB isolated in this study which showed strong antagonistic activity against S. aureus may be manipulated to become protective cultures in food products. While the homofermentative or heterofermentative LAB can be utilized in fermentation of food and non-food products depending on the by-products required during the fermentation.

  20. Isolation and characteristics of lactic acid bacteria isolated from ripe mulberries in Taiwan

    PubMed Central

    Chen, Yi-sheng; Wu, Hui-chung; Yanagida, Fujitoshi

    2010-01-01

    The objective of this study was to isolate, characterize, and identify lactic acid bacteria (LAB) from ripe mulberries collected in Taiwan. Ripe mulberry samples were collected at five mulberry farms, located in different counties of Taiwan. Eighty-eight acid-producing cultures were isolated from these samples, and isolates were divided into classes first by phenotype, then into groups by restriction fragment length polymorphism (RFLP) analysis and sequencing of 16S ribosomal DNA (rDNA). Phenotypic and biochemical characteristics led to identification of four bacterial groups (A to D). Weissella cibaria was the most abundant type of LAB distributed in four mulberry farms, and Lactobacillus plantarum was the most abundant LAB found in the remaining farm. Ten W. cibaria and one Lactococcus lactis subsp. lactis isolate produced bacteriocins against the indicator strain Lactobacillus sakei JCM 1157T. These results suggest that various LAB are distributed in ripe mulberries and W. cibaria was the most abundant LAB found in this study. PMID:24031571

  1. Antifouling potential of bacteria isolated from a marine biofilm

    NASA Astrophysics Data System (ADS)

    Gao, Min; Wang, Ke; Su, Rongguo; Li, Xuzhao; Lu, Wei

    2014-10-01

    Marine microorganisms are a new source of natural antifouling compounds. In this study, two bacterial strains, Kytococcus sedentarius QDG-B506 and Bacillus cereus QDG-B509, were isolated from a marine biofilm and identified. The bacteria fermentation broth could exert inhibitory effects on the growth of Skeletonema costatum and barnacle larvae. A procedure was employed to extract and identify the antifouling compounds. Firstly, a toxicity test was conducted by graduated pH and liquid-liquid extraction to determine the optimal extraction conditions. The best extraction conditions were found to be pH 2 and 100% petroleum ether. The EC 50 value of the crude extract of K. sedentarius against the test microalgae was 236.7 ± 14.08 μg mL-1, and that of B. cereus was 290.6 ± 27.11 μg mL-1. Secondly, HLB SPE columns were used to purify the two crude extracts. After purification, the antifouling activities of the two extracts significantly increased: the EC 50 of the K. sedentarius extract against the test microalgae was 86.4 ± 3.71 μg mL-1, and that of B. cereus was 92.6 ± 1.47 μg mL-1. These results suggest that the metabolites produced by the two bacterial strains are with high antifouling activities and they should be fatty acid compounds. Lastly, GC-MS was used for the structural elucidation of the compounds. The results show that the antifouling compounds produced by the two bacterial strains are myristic, palmitic and octadecanoic acids.

  2. Isolation and preliminary characterization of aerobic heterotrophic bacteria isolated from sub-glacial Antarctic water samples

    NASA Astrophysics Data System (ADS)

    Palma-Alvarez, R.; Lanoil, B. D.

    2002-05-01

    Recently, evidence has been accumulating supporting the presence of biogeochemically active microbial communities in cold, dark, and isolated subglacial environments. These environments are important sites of rock weathering, provide insight into global biogeochemistry during glacial periods, and are potential analogues for ancient Snowball Earth events and the ice-covered oceans of the Jovian moon, Europa. However, the extent of microbial influence on subglacial geochemistry is unclear. As part of an ongoing project to address the extent of that influence, we isolated aerobic heterotrophic bacteria from sediment-laden water from beneath Ice Stream C, a fast moving region of the Western Antarctic Ice Sheet (WAIS). Plates of a standard environmental media (R2A) were prepared at three dilutions (1x, 0.1x, 0.01x) and inoculated in duplicate in a HEPA-filtered environment. One replicate was incubated at 4oC, the other at room temperature in the dark. All plates showed abundant growth, although colony size was positively correlated with media concentration. One-hundred eighty-one colonies total were picked, grown in liquid R2A (1x concentration) at the same initial temperature, and characterized for Gram character, cell shape, cell size, and production of a diffusible yellow pigment with similar chemical characteristics to the siderophore, pyoverdine. Based on these characters, a moderate level of diversity was observed in these isolates. A few types dominated the samples, with several others found only rarely. Further characterization of these isolates is ongoing, and results of these studies and their possible implications for sub-glacial biogeochemistry are discussed.

  3. Isolation of marine bacteria by in situ culture on media-supplemented polyurethane foam.

    PubMed

    Yasumoto-Hirose, Mina; Nishijima, Miyuki; Ngirchechol, Metiek Kimie; Kanoh, Kaneo; Shizuri, Yoshikazu; Miki, Wataru

    2006-01-01

    Polyurethane foam (PUF) supplemented with various agar media was used in situ to trap marine bacteria and it consequently provided a substrate on which they could be cultivated while exposed to natural seawater in the coral reef area. The bacterial population on the PUF blocks was analyzed by denaturing gradient gel electrophoresis (DGGE) of polymerase chain reaction (PCR)-amplified 16S rDNA fragments. Changing the composition of the cultivation medium in the PUF blocks and selecting different sampling sites resulted in different bacteria being detected on the PUF blocks. For example, iron-utilizing (IU) bacteria, siderophore-producing (SP) bacteria, and petroleum-degrading (PD) bacteria were isolated from PUF blocks and it was discovered that IU and SP contained iron and PD contained hydrocarbon. This method opens up the possibility for isolating novel and useful marine bacteria.

  4. Degradation of Polycyclic Aromatic Hydrocarbons (PAHs) by Bacteria Isolated from Light Oil Polluted Soils

    NASA Astrophysics Data System (ADS)

    Ohnuma, T.; Suto, K.; Inoue, C.

    2007-03-01

    Polycyclic aromatic hydrocarbons (PAHs) have polluted soil and groundwater widely and for long term because of their low solubility at normal temperature. Several microorganisms, such as Pseudomonas sp., Sphigomonas sp., a white-rot fungus and so on, being able to decompose PAHs, have been isolated and researched. This study reported to investigate biodegradation of low molecule PAH by isolated bacteria from light oil polluted soil. 12 isolates were obtained from a light oil polluted soil using naphthalene, fluorene and anthracene as sole carbon source, of which 4 isolates grew with naphthalene, 4 isolates did with fluorene and 4 isolates did with anthracene. Among them 3 isolates showed the ability to degrade phenanthrene additionally. These phenanthrene degradation and growth rates were almost same as that of S. yanoikuyae (DSM6900), which is the typical bacteria of PAHs degrader. Therefore, the isolate seemed to have an expectation for PAHs degradation.

  5. Lipase Activity among Bacteria Isolated from Amazonian Soils

    PubMed Central

    Willerding, André Luis; de Oliveira, Luiz Antonio; Moreira, Francisco Wesen; Germano, Mariana Gomes; Chagas, Aloísio Freitas

    2011-01-01

    The objective of this study was to select lipase-producing bacteria collected from different counties of the Amazon region. Of the 440 bacteria strains, 181 were selected for the lipase assay in qualitative tests at Petri dishes, being 75 (41%) lipase positive. The enzymatic index was determined during fifteen days at different temperatures (30°, 35°, 40°, and 45°C). The highest lipase activity was observed within 72 hours at 30°C. Twelve bacteria strains presented an index equal to or greater than the standard used like reference, demonstrating the potential of microbial resource. After the bioassay in Petri dishes, the selected bacteria strains were analyzed in quantitative tests on p-nitrophenyl palmitate (p-NPP). A group of the strains was selected for other phases of study with the use in oleaginous substrates of the Amazonian flora, aiming for the application in processes like oil biotransformation. PMID:22007294

  6. Lipase Activity among Bacteria Isolated from Amazonian Soils.

    PubMed

    Willerding, André Luis; de Oliveira, Luiz Antonio; Moreira, Francisco Wesen; Germano, Mariana Gomes; Chagas, Aloísio Freitas

    2011-01-01

    The objective of this study was to select lipase-producing bacteria collected from different counties of the Amazon region. Of the 440 bacteria strains, 181 were selected for the lipase assay in qualitative tests at Petri dishes, being 75 (41%) lipase positive. The enzymatic index was determined during fifteen days at different temperatures (30°, 35°, 40°, and 45°C). The highest lipase activity was observed within 72 hours at 30°C. Twelve bacteria strains presented an index equal to or greater than the standard used like reference, demonstrating the potential of microbial resource. After the bioassay in Petri dishes, the selected bacteria strains were analyzed in quantitative tests on p-nitrophenyl palmitate (p-NPP). A group of the strains was selected for other phases of study with the use in oleaginous substrates of the Amazonian flora, aiming for the application in processes like oil biotransformation. PMID:22007294

  7. Draft Genome Sequences of Two Ureolytic Bacteria Isolated from Concrete Block Waste

    PubMed Central

    Park, Hongjae; Park, Byeonghyeok; Kim, Hyun Jung

    2016-01-01

    We sequenced genomes of two ureolytic bacteria, Bacillus sp. JH7 and Sporosarcina sp. HYO08, which were isolated from concrete waste and have a potential for biocementation applications. PMID:27491992

  8. Draft Genome Sequences of Two Ureolytic Bacteria Isolated from Concrete Block Waste.

    PubMed

    Park, Hongjae; Park, Byeonghyeok; Kim, Hyun Jung; Park, Woojun; Choi, In-Geol

    2016-01-01

    We sequenced genomes of two ureolytic bacteria, Bacillus sp. JH7 and Sporosarcina sp. HYO08, which were isolated from concrete waste and have a potential for biocementation applications. PMID:27491992

  9. Enrichment and isolation of crude oil degrading bacteria from some mussels collected from the Persian Gulf.

    PubMed

    Bayat, Zeynab; Hassanshahian, Mehdi; Hesni, Majid Askari

    2015-12-15

    To date, little is known about existing relationships between mussels and bacteria in hydrocarbon-contaminated marine environments. The aim of this study is to find crude oil degrading bacteria in some mussels at the Persian Gulf. Twenty eight crude oil degrading bacteria were isolated from three mussels species collected from oil contaminated area at Persian Gulf. According to high growth and degradation of crude oil four strains were selected between 28 isolated strains for more study. Determination the nucleotide sequence of the gene encoding for 16S rRNA show that these isolated strains belong to: Shewanella algae isolate BHA1, Micrococcus luteus isolate BHA7, Pseudoalteromonas sp. isolate BHA8 and Shewanella haliotis isolate BHA35. The residual crude oil in culture medium was analysis by Gas Chromatography (GC). The results confirmed that these strains can degrade: 47.24%, 66.08%, 27.13% and 69.17% of crude oil respectively. These strains had high emulsification activity and biosurfactant production. Also, the effects of some factors on crude oil degradation by isolated strains were studied. The results show that the optimum concentration of crude oil was 2.5% and the best degradation take place at 12% of salinity. This research is the first reports on characterization of crude oil degrading bacteria from mussels at Persian Gulf and by using of these bacteria in the field the effect of oil pollution can be reduce on this marine environment. PMID:26581816

  10. Enrichment and isolation of crude oil degrading bacteria from some mussels collected from the Persian Gulf.

    PubMed

    Bayat, Zeynab; Hassanshahian, Mehdi; Hesni, Majid Askari

    2015-12-15

    To date, little is known about existing relationships between mussels and bacteria in hydrocarbon-contaminated marine environments. The aim of this study is to find crude oil degrading bacteria in some mussels at the Persian Gulf. Twenty eight crude oil degrading bacteria were isolated from three mussels species collected from oil contaminated area at Persian Gulf. According to high growth and degradation of crude oil four strains were selected between 28 isolated strains for more study. Determination the nucleotide sequence of the gene encoding for 16S rRNA show that these isolated strains belong to: Shewanella algae isolate BHA1, Micrococcus luteus isolate BHA7, Pseudoalteromonas sp. isolate BHA8 and Shewanella haliotis isolate BHA35. The residual crude oil in culture medium was analysis by Gas Chromatography (GC). The results confirmed that these strains can degrade: 47.24%, 66.08%, 27.13% and 69.17% of crude oil respectively. These strains had high emulsification activity and biosurfactant production. Also, the effects of some factors on crude oil degradation by isolated strains were studied. The results show that the optimum concentration of crude oil was 2.5% and the best degradation take place at 12% of salinity. This research is the first reports on characterization of crude oil degrading bacteria from mussels at Persian Gulf and by using of these bacteria in the field the effect of oil pollution can be reduce on this marine environment.

  11. Genome Sequences of Three Spore-Forming Bacteria Isolated from the Feces of Organically Raised Chickens.

    PubMed

    Kennedy, Victoria; Van Laar, Tricia A; Aleru, Omoshola; Thomas, Michael; Ganci, Michelle; Rawat, Mamta

    2016-01-01

    Antibiotic feed supplements have been implicated in the rise of multidrug-resistant bacteria. An alternative to antibiotics is probiotics. Here, we report the genome sequences of two Bacillus and one Solibacillus species, all spore-forming, Gram-positive bacteria, isolated from the feces organically raised chicken feces, with potential to serve as probiotics. PMID:27587809

  12. Genome Sequences of Three Spore-Forming Bacteria Isolated from the Feces of Organically Raised Chickens

    PubMed Central

    Kennedy, Victoria; Van Laar, Tricia A.; Aleru, Omoshola; Thomas, Michael; Ganci, Michelle

    2016-01-01

    Antibiotic feed supplements have been implicated in the rise of multidrug-resistant bacteria. An alternative to antibiotics is probiotics. Here, we report the genome sequences of two Bacillus and one Solibacillus species, all spore-forming, Gram-positive bacteria, isolated from the feces organically raised chicken feces, with potential to serve as probiotics. PMID:27587809

  13. Molecular analysis of endophytic bacteria from the genus Bacillus isolated from tropical maize (Zea mays L.)

    PubMed Central

    Figueiredo, José Edson Fontes; Gomes, Eliane Aparecida; Guimarães, Claudia Teixeira; de Paula Lana, Ubiraci Gomes; Teixeira, Marta Aparecida; Lima, Guilherme Vitor Corrêa; Bressan, Wellington

    2009-01-01

    Endophytic bacteria play an important role in agriculture by improving plant performance and adaptation against biotic and abiotic stresses. In the present study molecular methods were used for identifying Bacillus endophytic bacteria isolated from Brazilian sweet corn. SDS-PAGE of whole-cell protein extract of forty-two isolates revealed a high number of scrutinable bands. Twenty-four isolates were identified in nine different groups of duplicated bacteria and eighteen were identified as unique. Some high-accumulated polipeptides with variable length were observed in almost isolates. Partial sequencing of 16S ribosomal gene revealed that all isolates are Bacillus sp. and among thirteen isolates with similar protein profiles, two were different strains. Among the forty-two isolates identified by rDNA sequencing, Bacillus subitilis and B. pumilus were the most frequenty species (15 and 12 isolates, respectively) followed by B. licheniformes (7 isolates), B. cereus (5 isolates) and B. amiloliquefascens (3 isolates). According to present results, SDS-PAGE technique could be used as a fast and cheap first tool for identifying inter-specific variation in maize endophytic bacterial collections while rDNA sequencing could be applied for analyzing intra-specific variation among isolates with similar protein profile as well as for taxonomic studies. PMID:24031395

  14. Potential of siderophore production by bacteria isolated from heavy metal: polluted and rhizosphere soils.

    PubMed

    Hussein, Khalid A; Joo, Jin Ho

    2014-06-01

    Recently, heavy metals have been shown to have a stimulating effect on siderophore biosynthesis in various bacteria. In addition, several studies have found that siderophore production is greater in bacteria isolated from soil near plant roots. The aim of this study was to compare the production of siderophores by bacterial strains isolated from heavy metal-contaminated and uncontaminated soils. Chrome azurol sulphonate was used to detect siderophore secretion by several bacterial strains isolated from heavy metal-contaminated and rhizosphere-uncontaminated soils with both a qualitative disc diffusion method and a quantitative ultraviolet spectrophotometric method. Siderophore production by rhizosphere bacteria was significantly greater than by bacteria isolated from contaminated soil. The Pearson's correlation test indicated a positive correlation between the amount of siderophore produced by bacteria isolated from the rhizosphere using the quantitative and qualitative detection methods and the amount of heavy metal in the soil. However, a significant negative correlation was observed between the amount of siderophore produced by bacteria isolated from heavy metal-contaminated soil and the amount of heavy metal (r value of -0.775, P < 0.001).

  15. Interstrain interactions between bacteria isolated from vacuum-packaged refrigerated beef.

    PubMed

    Zhang, Peipei; Baranyi, József; Tamplin, Mark

    2015-04-01

    The formation of bacterial spoilage communities in food is influenced by both extrinsic and intrinsic environmental factors. Although many reports describe how these factors affect bacterial growth, much less is known about interactions among bacteria, which may influence community structure. This study investigated interactions among representative species of bacteria isolated from vacuum-packaged (VP) beef. Thirty-nine effectors and 20 target isolates were selected, representing 10 bacterial genera: Carnobacterium, Pseudomonas, Hafnia, Serratia, Yersinia, Rahnella, Brochothrix, Bacillus, Leuconostoc, and Staphylococcus. The influence of live effectors on growth of target isolates was measured by spot-lawn agar assay and also in liquid culture medium broth using live targets and effector cell-free supernatants. Inhibition on agar was quantified by diameter of inhibition zone and in broth by measuring detection time, growth rate, and maximum population density. A number of interactions were observed, with 28.6% of isolates inhibiting and 4.2% promoting growth. The majority of Pseudomonas isolates antagonized growth of approximately one-half of target isolates. Two Bacillus spp. each inhibited 16 targets. Among lactic acid bacteria (LAB), Carnobacterium maltaromaticum inhibited a wider range of isolates compared to other LAB. The majority of effector isolates enhancing target isolate growth were Gram-negative, including Pseudomonas spp. and Enterobacteriaceae. These findings markedly improve the understanding of potential interactions among spoilage bacteria, possibly leading to more mechanistic descriptions of bacterial community formation in VP beef and other foods.

  16. Interstrain Interactions between Bacteria Isolated from Vacuum-Packaged Refrigerated Beef

    PubMed Central

    Zhang, Peipei; Baranyi, József

    2015-01-01

    The formation of bacterial spoilage communities in food is influenced by both extrinsic and intrinsic environmental factors. Although many reports describe how these factors affect bacterial growth, much less is known about interactions among bacteria, which may influence community structure. This study investigated interactions among representative species of bacteria isolated from vacuum-packaged (VP) beef. Thirty-nine effectors and 20 target isolates were selected, representing 10 bacterial genera: Carnobacterium, Pseudomonas, Hafnia, Serratia, Yersinia, Rahnella, Brochothrix, Bacillus, Leuconostoc, and Staphylococcus. The influence of live effectors on growth of target isolates was measured by spot-lawn agar assay and also in liquid culture medium broth using live targets and effector cell-free supernatants. Inhibition on agar was quantified by diameter of inhibition zone and in broth by measuring detection time, growth rate, and maximum population density. A number of interactions were observed, with 28.6% of isolates inhibiting and 4.2% promoting growth. The majority of Pseudomonas isolates antagonized growth of approximately one-half of target isolates. Two Bacillus spp. each inhibited 16 targets. Among lactic acid bacteria (LAB), Carnobacterium maltaromaticum inhibited a wider range of isolates compared to other LAB. The majority of effector isolates enhancing target isolate growth were Gram-negative, including Pseudomonas spp. and Enterobacteriaceae. These findings markedly improve the understanding of potential interactions among spoilage bacteria, possibly leading to more mechanistic descriptions of bacterial community formation in VP beef and other foods. PMID:25662972

  17. Phylogenetically Diverse Aerobic Anoxygenic Phototrophic Bacteria Isolated from Epilithic Biofilms in Tama River, Japan

    PubMed Central

    Hirose, Setsuko; Matsuura, Katsumi; Haruta, Shin

    2016-01-01

    The diversity of aerobic anoxygenic phototrophic (AAP) bacteria in freshwater environments, particularly in rivers, has not been examined in as much detail as in ocean environments. In the present study, we investigated the phylogenetic and physiological diversities of AAP bacteria in biofilms that developed on submerged stones in a freshwater river using culture methods. The biofilms collected were homogenized and inoculated on solid media and incubated aerobically in the dark. Sixty-eight red-, pink-, yellow-, orange-, or brown-colored colonies were isolated, and, of these, 28 isolates contained the photosynthetic pigment, bacteriochlorophyll (BChl) a. Phylogenetic analyses based on 16S rRNA gene sequences showed that the isolates were classified into 14 groups in 8 operational taxonomic units (OTUs) and distributed in the orders Rhodospirillales, Rhodobacterales, and Sphingomonadales of Alphaproteobacteria and in Betaproteobacteria. Physiological analyses confirmed that none of the representative isolates from any of the groups grew under anaerobic phototrophic conditions. Seven isolates in 4 OTUs showed a 16S rRNA gene sequence identity of 98.0% or less with any established species, suggesting the presence of previously undescribed species of AAP bacteria. Six isolates in 2 other OTUs had the closest relatives, which have not been reported to be AAP bacteria. Physiological comparisons among the isolates revealed differences in preferences for nutrient concentrations, BChl contents, and light-harvesting proteins. These results suggest that diverse and previously unknown AAP bacteria inhabit river biofilms. PMID:27453124

  18. Isolation and identification of bacteria from paperboard food packaging

    PubMed Central

    Mashhadi Mohammadzadeh-Vazifeh, Mojtaba; Khajeh-Nasiri, Shamsolmoluk; Hashemi, Shabnam; Fakhari, Javad

    2015-01-01

    Background and Objectives: Paper and paperboard packaging play an important role in safety and quality of food products. Common bacteria of paper and paperboard food packaging could grow due to specific conditions included humidity, temperature and major nutrition to contaminate the food. The purpose of this research was to investigate numbers and the types of bacteria in the food packaging paperboard. Materials and Methods: The surface and the depth of the each paperboard sample were examined by the dimension of one cm2 and one gram. The paperboard samples were randomly collected from popular confectionaries and fast food restaurants in Tehran, Iran. Results: The results indicated the range of 0.2×103 to >1.0×105 cfu/1g bacterial contamination in paperboard food packaging. Also, most detected bacteria were from spore forming and family Bacillaceae. Conclusion: The bioburden paperboard used for food packaging showed high contamination rate more than standard acceptance level. PMID:26719786

  19. Isolation and identification of ropy bacteria in raw milk.

    PubMed

    Cheung, B A; Westhoff, D C

    1983-09-01

    Approximately 4.2% of 4,000 Maryland-Virginia raw milk tanker samples developed ropiness when incubated at 10 degrees C. Of the 56 bacterial isolates 30 were identified by species. Klebsiella oxytoca and Pseudomonas aeruginosa were isolated most frequently. Other ropy isolates were identified as Pseudomonas spp., Chromobacterium, Flavobacterium multivorum, presumptive Yersinia pestis, Enterobacter agglomerans, Klebsiella pneumoniae, and Pasteurella-Actinobacter spp. Six of the Klebsiella oxytoca isolates were mesophilic (optimum temperatures of 32.0 to 37.8 degrees C) with two isolates having psychrotrophic tendencies (optimum temperature of 26.8 degrees C). All Pseudomonas aeruginosa isolates appeared to be psychrotropic in their temperature requirements (optimum temperature of 23.0 to 31.0 degrees C). Klebsiella oxytoca was significant in preliminary development of the ropy condition. All Klebsiella oxytoca isolates developed ropiness within 24 h. The Pseudomonas spp. and Klebsiella pneumoniae isolates required at long as 7 days to develop detectable ropiness at 10 degrees C. A recommended Klebsiella oxytoca differentiation agar is presented as a rapid screening method during outbreaks where Klebsiella oxytoca is the organism of significance. PMID:6685140

  20. Genetic Diversity and Association Characters of Bacteria Isolated from Arbuscular Mycorrhizal Fungal Spore Walls.

    PubMed

    Selvakumar, Gopal; Krishnamoorthy, Ramasamy; Kim, Kiyoon; Sa, Tong-Min

    2016-01-01

    Association between arbuscular mycorrhizal fungi (AMF) and bacteria has long been studied. However, the factors influencing their association in the natural environment is still unknown. This study aimed to isolate bacteria associated with spore walls of AMF and identify their potential characters for association. Spores collected from coastal reclamation land were differentiated based on their morphology and identified by 18S rDNA sequencing as Funneliformis caledonium, Racocetra alborosea and Funneliformis mosseae. Bacteria associated with AMF spore walls were isolated after treating them with disinfection solution at different time intervals. After 0, 10 and 20 min of spore disinfection, 86, 24 and 10 spore associated bacteria (SAB) were isolated, respectively. BOX-PCR fingerprinting analysis showed that diverse bacterial communities were associated to AMF spores. Bacteria belonging to the same genera could associate with different AMF spores. Gram positive bacteria were more closely associated with AMF spores. Isolated SAB were characterized and tested for spore association characters such as chitinase, protease, cellulase enzymes and exopolysaccharide production (EPS). Among the 120 SAB, 113 SAB were able to show one or more characters for association and seven SAB did not show any association characters. The 16S rDNA sequence of SAB revealed that bacteria belonging to the phyla Firmicutes, Proteobacteria, Actinobacteria and Bactereiodes were associated with AMF spore walls. PMID:27479250

  1. Genetic Diversity and Association Characters of Bacteria Isolated from Arbuscular Mycorrhizal Fungal Spore Walls

    PubMed Central

    Selvakumar, Gopal; Krishnamoorthy, Ramasamy; Kim, Kiyoon; Sa, Tong-Min

    2016-01-01

    Association between arbuscular mycorrhizal fungi (AMF) and bacteria has long been studied. However, the factors influencing their association in the natural environment is still unknown. This study aimed to isolate bacteria associated with spore walls of AMF and identify their potential characters for association. Spores collected from coastal reclamation land were differentiated based on their morphology and identified by 18S rDNA sequencing as Funneliformis caledonium, Racocetra alborosea and Funneliformis mosseae. Bacteria associated with AMF spore walls were isolated after treating them with disinfection solution at different time intervals. After 0, 10 and 20 min of spore disinfection, 86, 24 and 10 spore associated bacteria (SAB) were isolated, respectively. BOX-PCR fingerprinting analysis showed that diverse bacterial communities were associated to AMF spores. Bacteria belonging to the same genera could associate with different AMF spores. Gram positive bacteria were more closely associated with AMF spores. Isolated SAB were characterized and tested for spore association characters such as chitinase, protease, cellulase enzymes and exopolysaccharide production (EPS). Among the 120 SAB, 113 SAB were able to show one or more characters for association and seven SAB did not show any association characters. The 16S rDNA sequence of SAB revealed that bacteria belonging to the phyla Firmicutes, Proteobacteria, Actinobacteria and Bactereiodes were associated with AMF spore walls. PMID:27479250

  2. Production of halomethanes and isoprene in the culture of bacteria isolated from brackish water

    NASA Astrophysics Data System (ADS)

    Fujimori, T.; Taniai, G.; Kurihara, M.; Tamegai, H.; Hashimoto, S.

    2010-12-01

    Halomethanes produced naturally are important source of halogen in troposphere and stratosphere. In the ocean, macroalgae and phytoplankton have been considered to be the main producers of halomethanes. Recent investigations have shown that marine bacteria also produces halomethane such as iodomethane. However, knowledge of aquatic halomethane production, especially by bacteria, is insufficient. Here we survey bacteria, which produce volatile organic compounds (VOCs) including halomethanes, from brackish area (salinity: about 5‰) where high halomethane productions were observed. Bacteria was isolated and incubated in marine broth 2216, which is the media for marine bacteria. The VOCs such as halomethanes in the gas phase above cultured samples was determined using dynamic headspace (GESTEL DHS) - gas chromatograph (Agilent 6890N)- mass spectrometer (Agilent 5975C). The optical density at 600 nm (OD600) was also measured during the cultured period. From the result of the isolation and measurement of VOCs, some of the isolated bacteria produced halomethanes. For example, monohalomethanes (from 1 to about 600 nM) and isoprene (up to about 400 nM) were increased for several days in the culture (dibromomethane, chloroiodomethane, bromoiodomethane, and tribromomethane were not detected). Since halomethanes are abundant at the sampling point (under 1% of light intensity of the surface), bacteria is one of the possible candidates for halomethane producer there. Now, we are studying on the identification by 16S rRNA sequence analysis of bacteria collected from brackish water.

  3. [Characteristics of microbial community structure during isolation of electrical active bacteria].

    PubMed

    Wang, Min; Zhao, Yang- Guo; Lu, Shan-Shan

    2014-10-01

    To investigate the effect of selective culturing on microorganisms and functional role of electrical active bacteria in biofilm, some exoelectrogens were isolated from microbial fuel cell (MFC) anodic biofilm using Hungate roll-tube technique with iron oxide as indicator. At the same time, the dynamics of the microbial community structure was monitored during the pure culture isolation. The results show that maximum voltages of MFCs feeding with lactic acid, acetic acid and steroid wastewater are 0.57, 0.60 and 0.40 V respectively. The dominant bacteria isolated from seed sludge and anodic films feeding with acetate and lactate belong to phylum Proteobacteria; while steroid wastewater contains relative high diversity of bacteria, i. e. Proteobacteria, Firmicutes and Bacteroidetes. After enriching and culturing, two bacteria were consequently obtained, which shared the highest similarity with Enterobacter ludwigii and Citrobacter freundii respectively. When inoculated in MFC with lactic acid as the substrate, they produced maximum voltage of 0.10 and 0.17 V individually. This study shows that electrical active bacteria can be isolated from the MFC anodic biofilm using anaerobic gradient dilution culture techniques with iron oxide as indicator. Microbial community structure presents markedly shifting during the bacteria isolation owing to its selectivity.

  4. Multidrug-Resistance and Toxic Metal Tolerance of Medically Important Bacteria Isolated from an Aquaculture System

    PubMed Central

    Resende, Juliana Alves; Silva, Vânia L.; Fontes, Cláudia Oliveira; Souza-Filho, Job Alves; de Oliveira, Tamara Lopes Rocha; Coelho, Cíntia Marques; César, Dionéia Evangelista; Diniz, Cláudio Galuppo

    2012-01-01

    The use of antimicrobials and toxic metals should be considered carefully in aquaculture and surrounding environments. We aimed to evaluate medically relevant bacteria in an aquaculture system and their susceptibility to antimicrobials and toxic metals. Selective cultures for enterobacteria (ENT), non-fermenting Gram-negative rods (NFR) and Gram-positive cocci (GPC) were obtained from water samples collected in two different year seasons. The isolated bacteria were biochemically identified and antimicrobial and toxic metal susceptibility patterns were determined. Overall, 407 representative strains were recovered. In general, bacteria isolated from fish ponds showed higher multiple antibiotic resistance indices when compared to those isolated from a water-fed canal. Resistance to penicillin and azithromycin was observed more frequently in the GPC group, whereas resistance to ampicillin and ampicillin/sulbactam or gentamicin was observed more frequently in the ENT and NFR groups, respectively. All the isolated bacteria were tolerant to nickel, zinc, chromium and copper at high levels (≥1,024 μg mL−1), whereas tolerance to cadmium and mercury varied among the isolated bacteria (2–1,024 μg mL−1). Multidrug-resistant bacteria were more frequent and diverse in fish ponds than in the water-fed canal. A positive correlation was observed between antimicrobial resistance and metal tolerance. The data point out the need for water treatment associated with the aquaculture system. PMID:22972388

  5. Isolation of unique butyrate-producing bacteria from swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Butyrate-producing bacteria in humans contribute to a healthy gastrointestinal tract and are known to be species from clostridial clusters IV, IX, XIVa, and XVI - with the community dominated by clusters XIVa and IV. However, the composition of the butyrate-producing bacterial community in swine is...

  6. Free-Living Heterotrophic Nitrogen-Fixing Bacteria Isolated from Fuel-Contaminated Antarctic Soils

    PubMed Central

    Eckford, Ruth; Cook, Fred D.; Saul, David; Aislabie, Jackie; Foght, Julia

    2002-01-01

    Five bacterial isolates enriched from fuel-contaminated Antarctic soils fixed nitrogen in the dark heterotrophically and nonsymbiotically. Two isolates utilized jet fuel vapors and volatile hydrocarbons for growth but not in N-deficient medium. Bacteria such as these may contribute to in situ biodegradation of hydrocarbons in Antarctic soils. PMID:12324373

  7. Antimicrobial susceptibility of bacteria isolated from pinnipeds stranded in central and northern California.

    PubMed

    Johnson, S P; Nolan, S; Gulland, F M

    1998-09-01

    Over a 2-yr period (1994-1995), the antimicrobial susceptibilities of 129 bacterial isolates recovered from live stranded California sea lions (Zalophus californianus), harbor seals (Phoca vitulina), and northern elephant seals (Mirounga angustirostris) were studied. Nineteen genera of bacteria were isolated from various sites of inflammation; abscesses and umbilici were the most common sites. Seventy-two percent of the bacterial isolated were gram negative, and the Enterobacteriaceae (Escherichia coli, Proteus spp., Klebsiella spp., Salmonella spp.) accounted for 75% of the gram-negative isolates. All of the gram-positive isolates were either Enterococcus spp. or Staphylococcus aureus. Multiple drug resistance was present in all but one of the bacterial isolates. The gram-positive bacteria were most susceptible to amoxicillin-clavulanic acid (77% of 36 isolates) and least susceptible to lincomycin (18% of 11 isolates). The gram-negative bacteria were most susceptible to amikacin (91% of 91 isolates) and least susceptible to clindamycin (3% of 109 isolates). PMID:9809600

  8. Isolation of novel bacteria, including a candidate division, from geothermal soils in New Zealand.

    PubMed

    Stott, Matthew B; Crowe, Michelle A; Mountain, Bruce W; Smirnova, Angela V; Hou, Shaobin; Alam, Maqsudul; Dunfield, Peter F

    2008-08-01

    We examined bacterial diversity of three geothermal soils in the Taupo Volcanic Zone of New Zealand. Phylogenetic analysis of 16S rRNA genes recovered directly from soils indicated that the bacterial communities differed in composition and richness, and were dominated by previously uncultured species of the phyla Actinobacteria, Acidobacteria, Chloroflexi, Proteobacteria and candidate division OP10. Aerobic, thermophilic, organotrophic bacteria were isolated using cultivation protocols that involved extended incubation times, low-pH media and gellan as a replacement gelling agent to agar. Isolates represented previously uncultured species, genera, classes, and even a new phylum of bacteria. They included members of the commonly cultivated phyla Proteobacteria, Firmicutes, Thermus/Deinococcus, Actinobacteria and Bacteroidetes, as well as more-difficult-to-cultivate groups. Isolates possessing < 85% 16S rRNA gene sequence identity to any cultivated species were obtained from the phyla Acidobacteria, Chloroflexi and the previously uncultured candidate division OP10. Several isolates were prevalent in 16S rRNA gene clone libraries constructed directly from the soils. A key factor facilitating isolation was the use of gellan-solidified plates, where the gellan itself served as an energy source for certain bacteria. The results indicate that geothermal soils are a rich potential source of novel bacteria, and that relatively simple cultivation techniques are practical for isolating bacteria from these habitats.

  9. Use of mycelia as paths for the isolation of contaminant‐degrading bacteria from soil

    PubMed Central

    Furuno, Shoko; Remer, Rita; Chatzinotas, Antonis; Harms, Hauke; Wick, Lukas Y.

    2012-01-01

    Summary Mycelia of fungi and soil oomycetes have recently been found to act as effective paths boosting bacterial mobility and bioaccessibility of contaminants in vadose environments. In this study, we demonstrate that mycelia can be used for targeted separation and isolation of contaminant‐degrading bacteria from soil. In a ‘proof of concept’ study we developed a novel approach to isolate bacteria from contaminated soil using mycelia of the soil oomycete Pythium ultimum as translocation networks for bacteria and the polycyclic aromatic hydrocarbon naphthalene (NAPH) as selective carbon source. NAPH‐degrading bacterial isolates were affiliated with the genera Xanthomonas, Rhodococcus and Pseudomonas. Except for Rhodococcus the NAPH‐degrading isolates exhibited significant motility as observed in standard swarming and swimming motility assays. All steps of the isolation procedures were followed by cultivation‐independent terminal 16S rRNA gene terminal fragment length polymorphism (T‐RFLP) analysis. Interestingly, a high similarity (63%) between both the cultivable NAPH‐degrading migrant and the cultivable parent soil bacterial community profiles was observed. This suggests that mycelial networks generally confer mobility to native, contaminant‐degrading soil bacteria. Targeted, mycelia‐based dispersal hence may have high potential for the isolation of bacteria with biotechnologically useful properties. PMID:22014110

  10. The aflatoxin B1 isolating potential of two lactic acid bacteria

    PubMed Central

    Hamidi, Adel; Mirnejad, Reza; Yahaghi, Emad; Behnod, Vahid; Mirhosseini, Ali; Amani, Sajad; Sattari, Sara; Darian, Ebrahim Khodaverdi

    2013-01-01

    Objective To determine lactic acid bacteria's capability to enhance the process of binding and isolating aflatoxin B1 and to utilize such lactic acid bacteria as a food supplement or probiotic products for preventing absorption of aflatoxin B1 in human and animal bodies. Methods In the present research, the bacteria were isolated from five different sources. For surveying the capability of the bacteria in isolating aflatoxin B1, ELISA method was implemented, and for identifying the resultant strains through 16S rRNA sequencing method, universal primers were applied. Results Among the strains which were isolated, two strains of Lactobacillus pentosus and Lactobacillus beveris exhibited the capability of absorbing and isolating aflatoxin B1 by respectively absorbing and discharging 17.4% and 34.7% of the aforementioned toxin existing in the experiment solution. Conclusions Strains of Lactobacillus pentosus and Lactobacillus beveris were isolated from human feces and local milk samples, respectively. And both strains has the ability to isolate or bind with aflatoxin B1. PMID:23998015

  11. Dibenzothiophene desulfurization capability and evolutionary divergence of newly isolated bacteria.

    PubMed

    Akhtar, Nasrin; Ghauri, Muhammad A; Akhtar, Kalsoom

    2016-08-01

    Metabolically microorganisms are diverse, and they are capable of transforming almost every known group of chemical compounds present in coal and oil in various forms. In this milieu, one of the important microbial metabolic processes is the biodesulfurization [cleavage of carbon-sulfur (C-S) bond] of thiophenic compounds, such as dibenzothiophene (DBT), which is the most abundant form of organic sulfur present in fossil fuels. In the current study, ten newly isolated bacterial isolates, designated as species of genera Gordonia, Amycolatopsis, Microbacterium and Mycobacterium, were enriched from different samples in the presence of DBT as a sole source of organic sulfur. The HPLC analysis of the DBT grown cultures indicated the consumption of DBT and accumulation of 2-hydroxybiphenyl (2-HBP). Detection of 2-HBP, a marker metabolite of 4S (sulfoxide-sulfone-sulfinate-sulfate) pathway, suggested that the newly isolated strains harbored metabolic activity for DBT desulfurization through the cleavage of C-S bond. The maximum 2-HBP formation rate was 3.5 µmol/g dry cell weight (DCW)/h. The phylogenetic analysis of the new isolates showed that they had diverse distribution within the phylogenetic tree and formed distinct clusters, suggesting that they might represent strains of already reported species or they were altogether new species. Estimates of evolutionary divergence showed high level of nucleotide divergence between the isolates within the same genus. The new isolates were able to use a range of heterocyclic sulfur compounds, thus making them suitable candidates for a robust biodesulfurization system for fossil fuels. PMID:26973057

  12. Isolation of Gemmata-like and Isosphaera-like planctomycete bacteria from soil and freshwater.

    PubMed

    Wang, Jenny; Jenkins, Cheryl; Webb, Richard I; Fuerst, John A

    2002-01-01

    New cultured strains of the planctomycete division (order Planctomycetales) of the domain Bacteria related to species in the genera Gemmata and Isosphaera were isolated from soil, freshwater, and a laboratory ampicillin solution. Phylogenetic analysis of the 16S rRNA gene from eight representative isolates showed that all the isolates were members of the planctomycete division. Six isolates clustered with Gemmata obscuriglobus and related strains, while two isolates clustered with Isosphaera pallida. A double-membrane-bounded nucleoid was observed in Gemmata-related isolates but not in Isosphaera-related isolates, consistent with the ultrastructures of existing species of each genus. Two isolates from this study represent the first planctomycetes successfully cultivated from soil. PMID:11772655

  13. Isolation of Gemmata-Like and Isosphaera-Like Planctomycete Bacteria from Soil and Freshwater

    PubMed Central

    Wang, Jenny; Jenkins, Cheryl; Webb, Richard I.; Fuerst, John A.

    2002-01-01

    New cultured strains of the planctomycete division (order Planctomycetales) of the domain Bacteria related to species in the genera Gemmata and Isosphaera were isolated from soil, freshwater, and a laboratory ampicillin solution. Phylogenetic analysis of the 16S rRNA gene from eight representative isolates showed that all the isolates were members of the planctomycete division. Six isolates clustered with Gemmata obscuriglobus and related strains, while two isolates clustered with Isosphaera pallida. A double-membrane-bounded nucleoid was observed in Gemmata-related isolates but not in Isosphaera-related isolates, consistent with the ultrastructures of existing species of each genus. Two isolates from this study represent the first planctomycetes successfully cultivated from soil. PMID:11772655

  14. Isolation and identification of cobalt- and caesium-resistant bacteria from a nuclear fuel storage pond.

    PubMed

    Dekker, Linda; Osborne, Thomas H; Santini, Joanne M

    2014-10-01

    One of the issues facing the nuclear power industry is how to store spent nuclear fuel which is contaminated with radionuclides produced during nuclear fission, including caesium ((134)Cs(+), (135)Cs(+) and (137)Cs(+)) and cobalt ((60)Co(2+)). In this study, we have isolated Co(2+)- and Cs(+)-resistant bacteria from water collected from a nuclear fuel storage pond. The most resistant Cs(+) and Co(2+) isolates grew in the presence of 500 mM CsCl and 3 mM CoCl2. Strain Cs67-2 is resistant to fourfold more Cs(+) than Cupriavidus metallidurans str. CH34 making it the most Cs(+)-resistant strain identified to date. The Cs(+)-resistant isolates were closely related to bacteria in the Serratia and Yersinia genera, while the Co(2+)-resistant isolates were closely related to the Curvibacter and Tardiphaga genera. These new isolates could be used for bioremediation.

  15. Isolation and characterization of some moderately halophilic bacteria with lipase activity.

    PubMed

    Ghasemi, Y; Rasoul-Amini, S; Kazemi, A; Zarrinic, G; Morowvat, M H; Kargar, M

    2011-01-01

    Lipases are an important class of enzymes which catalyze the hydrolysis of long chain triglycerides and constitute the most prominent group ofbiocatalysts for biotechnological applications. There are a number of lipases, produced by some halophilic microorganisms. In this study, some lipase producing bacteria from Maharlu salt lake located in south of Iran were isolated. All isolates were screened for true lipase activity on plates containing olive oil. The lipase activity was measured using titrimetric methods. Among thirty three isolates, thirteen strains demonstrating orange zone around colonies under UV light, were selected for identification using the molecular methods and some morphological characteristics. The bacterium Bacillus vallismortis BCCS 007 with 3.41 +/- 0.14 U/mL lipase activity was selected as the highest lipase producing isolate. This is the first report of isolation and molecular identification of lipase producing bacteria from Maharlu lake. PMID:22073547

  16. Isolation and identification of cobalt- and caesium-resistant bacteria from a nuclear fuel storage pond.

    PubMed

    Dekker, Linda; Osborne, Thomas H; Santini, Joanne M

    2014-10-01

    One of the issues facing the nuclear power industry is how to store spent nuclear fuel which is contaminated with radionuclides produced during nuclear fission, including caesium ((134)Cs(+), (135)Cs(+) and (137)Cs(+)) and cobalt ((60)Co(2+)). In this study, we have isolated Co(2+)- and Cs(+)-resistant bacteria from water collected from a nuclear fuel storage pond. The most resistant Cs(+) and Co(2+) isolates grew in the presence of 500 mM CsCl and 3 mM CoCl2. Strain Cs67-2 is resistant to fourfold more Cs(+) than Cupriavidus metallidurans str. CH34 making it the most Cs(+)-resistant strain identified to date. The Cs(+)-resistant isolates were closely related to bacteria in the Serratia and Yersinia genera, while the Co(2+)-resistant isolates were closely related to the Curvibacter and Tardiphaga genera. These new isolates could be used for bioremediation. PMID:25091383

  17. The role of denitrification on arsenite oxidation and arsenic mobility in an anoxic sediment column model with activated alumina.

    PubMed

    Sun, Wenjie; Sierra-Alvarez, Reyes; Field, Jim A

    2010-12-01

    Arsenite (As(III)) is the predominant arsenic (As) species in reducing environments. As(III) is less strongly adsorbed than As(V) at circumneutral pH conditions by common non-iron metal oxides in sediments such as those of aluminum. Therefore, oxidation of As(III) to As(V) could contribute to an improved immobilization of As and thus help mitigate As contamination in groundwater. Microbial oxidation of As(III) is known to readily under aerobic conditions, however, the dissolved oxygen (O₂) concentration in groundwater may be limited due to the poor solubility of O₂ and its high chemical reactivity with reduced compounds. Nitrate (NO₃⁻), can be considered as an alternative electron acceptor, which can support oxidation of As(III) to As(V) by denitrifying bacteria. In this study, two up-flow sediment columns packed with activated alumina (AA) were utilized to demonstrate the role of denitrification on the oxidation of As(III) to As(V) and its contribution to improved As adsorption onto AA. One column was supplied with NO₃⁻(C1) and its performance was compared with a control column lacking NO₃⁻(C2). During most of the operation when the pH was in the circumneutral range (days 50-250), the release of arsenic was greater from C2 compared to C1. The effluent As concentrations started increasing on days 60 and 100 in C2 and C1, respectively. Complete breakthrough started on day 200 in C2; whereas in C1, complete breakthrough was never achieved. The effluent and solid phase As speciation was dominated by As(V) in C1, indicating the occurrence of As(III) oxidation due to NO₃⁻; whereas in C2, only As(III) was dominant. This study illustrates a bioremediation or natural attenuation process based on anoxic microbial NO₃⁻-dependent oxidation of As(III) to more readily adsorbed As(V) as a means to enhance the immobilization of As on alumina oxide particles in subsurface environments.

  18. Coincident plasmids and antimicrobial resistance in marine bacteria isolated from polluted and unpolluted Atlantic Ocean Samples

    SciTech Connect

    Baya, A.M.; Brayton, P.R.; Brown, V.L.; Grimes, D.J.; Russek-Cohen, E.; Colwell, R.R.

    1986-06-01

    Sewage effluent and outfall confluence samples were collected at the Barceloneta Regional Treatment Plant in Barceloneta, Puerto Rico; outfall confluence samples at Ocean City, Md., were also collected. Samples from uncontaminated open ocean areas served as clean-water controls. Bacteria were enriched in marine broth 2216 amended with 1 ..mu..g of one of a set of chemical selected for study per ml: nitrobenzene, dibutyl phthalate, m-cresol, o-cresol, 4-nitroaniline, bis(tributyltin) oxide, and quinone. MICs of the chemicals were determined individually for all isolates. Bacterial isolates were evaluated for resistance to nine different antibiotics and for the presence of plasmid DNA. Treated sewage was found to contain large numbers of bacteria simultaneously possessing antibiotic resistance, chemical resistance, and multiple bands of plasmic DNA. Bacteria resistant to penicillin, erythromycin, nalidixic acid, ampicillin, m-cresol, quinone, and bis(tributyltin) oxide were detected in nearly all samples, but only sewage outfall confluence samples yielded bacterial isolates that were resistant to streptomycin. Bacteria resistant to a combination of antibiotics, including kanamycin, chloramphenicol, gentamicin, and tetracycline, were isolated only from sewage effluent samples. It is concluded that bacterial isolates derived from toxic chemical wastes more frequently contain plasmid DNA and demonstrate antimicrobial resistance than do bacterial isolates from domestic sewage-impacted waters or from uncontaminated open ocean sites.

  19. Review of disinfectant susceptibility of bacteria isolated in hospital to commonly used disinfectants.

    PubMed

    Shiraishi, T; Nakagawa, Y

    1993-01-01

    The susceptibility of clinical isolates and indigenous bacteria to commonly used disinfectants was investigated during different time periods. Among the clinical isolates tested during Period I (August 1985-July 1986, 6 genera, 9 species, 353 strains) there were many resistant strains not killed within a short period of time by the recommended concentration of chlorhexidine gluconate (CHG) or benzalkonium chloride (BAC). During Period II (October 1987-May 1988, 6 genera, 9 species, 152 strains), however, a reduction in the number of strains resistant to these disinfectants was observed. The use of the broad spectrum disinfectant povidone-iodine (PVP-I) increased between those two time periods. With regard to the susceptibility of indigenous bacteria, tests were carried out on bacteria isolated from sinks and physicians' hands in the gastroenterology division of the Departments of Internal Medicine and Surgery at the hospital. During Phase I (April-June 1987), strains of Pseudomonas and Serratia resistant to CHG and BAC were isolated from sinks, while the same strains of Serratia were also isolated from physicians' hands. During Phase II (March-May 1988), however, no resistant strains were isolated. A comparison of the consumption of disinfectants during the two phases revealed that a greater amount of CHG was consumed during Phase I, while a greater amount of PVP-I was consumed during Phase II. There was a strong indication, therefore, that bacteria resistant to CHG and BAC decrease with the increased use of PVP-I.

  20. Association of metal tolerance with multiple antibiotic resistance of bacteria isolated from drinking water

    SciTech Connect

    Calomiris, J.J.; Armstrong, J.L.; Seidler, R.J.

    1984-06-01

    Bacterial isolates from the drinking water system of an Oregon coastal community were examined to assess the association of metal tolerance with multiple antibiotic resistance. Positive correlations between tolerance to high levels of Cu/sup 2 +/, Pb/sup 2 +/, and Zn/sup 2 +/ and multiple antibiotic resistance were noted among bacteria from distribution waters but not among bacteria from raw waters. Tolerances to higher levels of Al/sup 3 +/ and Sn/sup 2 +/ were demonstrated more often by raw water isolates which were not typically multiple antibiotic resistant. A similar incidence of tolerance to Cd/sup 2 +/ was demonstrated by isolates of both water types and was not associated with multiple antibiotic resistance. These results suggest that simultaneous selection phenomena occurred in distribution water for bacteria which exhibited unique patterns of tolerance to Cu/sup 2 +/, Pb/sup 2 +/, and Zn/sup 2 +/ and antibiotic resistance.

  1. Enumeration, isolation, and characterization of n(2)-fixing bacteria from seawater.

    PubMed

    Guerinot, M L; Colwell, R R

    1985-08-01

    Marine pelagic N(2)-fixing bacteria have not, in general, been identified or quantified, since low or negligible rates of N(2) fixation have been recorded for seawater when blue-green algae (cyanobacteria) are absent. In the study reported here, marine N(2)-fixing bacteria were found in all samples of seawater collected and were analyzed by using a most-probable-number (MPN) method. Two different media were used which allowed growth of microaerophiles, as well as that of aerobes and facultative anaerobes. MPN values obtained for N(2)-fixing bacteria ranged from 0.4 to 1 x 10 per liter for water collected off the coast of Puerto Rico and from 2 to 5.5 x 10 per liter for Chesapeake Bay water. Over 100 strains of N(2)-fixing bacteria were isolated from the MPN tubes and classified, yielding four major groups of NaCl-requiring bacteria based on biochemical characteristics. Results of differential filtration studies indicate that N(2)-fixing bacteria may be associated with phytoplankton. In addition, when N(2)-fixing bacteria were inoculated into unfiltered seawater and incubated in situ, nitrogenase activity could be detected within 1 h. However, no nitrogenase activity was detected in uninoculated seawater or when bacteria were incubated in 0.2-mum-filtered (phytoplankton-free) seawater. The ability of these isolates to fix N(2) at ambient conditions in seawater and the large variety of N(2)-fixing bacteria isolated and identified lead to the conclusion that N(2) fixation in the ocean may occur to a greater degree than previously believed. PMID:16346855

  2. Isolation of bacteria from toxic dinoflagellate Alexandrium minutum and their effects on algae toxicity.

    PubMed

    Lu, Y H; Chai, T J; Hwang, D F

    2000-11-01

    Attempts were made to isolate the bacteria from toxic dinoflagellate Alexandrium minutum T1 and to study the effect of these bacteria on the growth and toxicity of A. minutum T1. It was found that intracellular bacterial species including Pasteurella haemolytica, Pseudomonas vesicularis, and Sphingomonas sp., and extracellular bacterial species including Pasteurolla pneumotropica, Morganella wisconsensis, Flavobacterium oryzihabitans, Pseudomonas pseudomallei, and Sphingomonas sp. All of them were cultured and determined to have non-PSP-producing ability. The maximum cell number of A. minutum cultured without isolated bacteria was higher than that cultured with isolated bacteria. The total toxicity of A. minutum cultured with bacteria was similar to that of A. minutum T1 cultured without bacteria from lag phase to stationary phase, but it was lower after stationary phase. The growth of A. minutum T1 cultured without antibiotics was also better than that cultured with antibiotics. The total toxicity of A. minutum cultured without antibiotics was higher than that of A. minutum cultured with antibiotics. However, the cell toxicity of A. minutum did not decrease even if the culture medium was added with antibiotics.

  3. Isolation of bacteria from toxic dinoflagellate Alexandrium minutum and their effects on algae toxicity.

    PubMed

    Lu, Y H; Chai, T J; Hwang, D F

    2000-11-01

    Attempts were made to isolate the bacteria from toxic dinoflagellate Alexandrium minutum T1 and to study the effect of these bacteria on the growth and toxicity of A. minutum T1. It was found that intracellular bacterial species including Pasteurella haemolytica, Pseudomonas vesicularis, and Sphingomonas sp., and extracellular bacterial species including Pasteurolla pneumotropica, Morganella wisconsensis, Flavobacterium oryzihabitans, Pseudomonas pseudomallei, and Sphingomonas sp. All of them were cultured and determined to have non-PSP-producing ability. The maximum cell number of A. minutum cultured without isolated bacteria was higher than that cultured with isolated bacteria. The total toxicity of A. minutum cultured with bacteria was similar to that of A. minutum T1 cultured without bacteria from lag phase to stationary phase, but it was lower after stationary phase. The growth of A. minutum T1 cultured without antibiotics was also better than that cultured with antibiotics. The total toxicity of A. minutum cultured without antibiotics was higher than that of A. minutum cultured with antibiotics. However, the cell toxicity of A. minutum did not decrease even if the culture medium was added with antibiotics. PMID:11126517

  4. Isolation, characterization and phylogeny of sponge-associated bacteria with antimicrobial activities from Brazil.

    PubMed

    Santos, Olinda C S; Pontes, Paula V M L; Santos, Juliana F M; Muricy, Guilherme; Giambiagi-deMarval, Marcia; Laport, Marinella S

    2010-09-01

    Bacteria associated with marine sponges represent a rich source of bioactive metabolites. The aim of this study was to isolate and characterize bacteria with antimicrobial activities from Brazilian sponges. A total of 158 colony-forming units were isolated from nine sponge species. Among these, 12 isolates presented antimicrobial activities against pathogenic bacteria. Based on comparative sequence analysis of their 16S rRNA genes, the sponge-associated bacterial strains could be subdivided into three phylogenetically different clusters. Five strains were affiliated with Firmicutes (genera Bacillus and Virgibacillus), three with alpha-Proteobacteria (Pseudovibrio sp.) and four with gamma-Proteobacteria (genera Pseudomonas and Stenotrophomonas). The sponge-associated bacterial strains Pseudomonas fluorescens H40 and H41 and Pseudomonas aeruginosa H51 exhibited antimicrobial activity against both Gram-negative and Gram-positive bacteria, including strains such as vancomycin-resistant Enterococcus faecium and multiresistant Klebsiella pneumoniae. Bacillus pumilus Pc31 and Pc32, Pseudovibrio ascidiaceicola Pm31 and Ca31 and Pseudovibrio denitrificans Mm37 strains were more effective against Gram-positive bacteria. These findings suggest that the identified strains may contribute to the search for new sources of antimicrobial substances, an important strategy for developing alternative therapies to treat infections caused by multidrug-resistant bacteria. PMID:20600863

  5. Isolation and characterization of phenol-degrading denitrifying bacteria.

    PubMed

    van Schie, P M; Young, L Y

    1998-07-01

    Phenol is a man-made as well as a naturally occurring aromatic compound and an important intermediate in the biodegradation of natural and industrial aromatic compounds. Whereas many microorganisms that are capable of aerobic phenol degradation have been isolated, only a few phenol-degrading anaerobic organisms have been described to date. In this study, three novel nitrate-reducing microorganisms that are capable of using phenol as a sole source of carbon were isolated and characterized. Phenol-degrading denitrifying pure cultures were obtained by enrichment culture from anaerobic sediments obtained from three different geographic locations, the East River in New York, N.Y., a Florida orange grove, and a rain forest in Costa Rica. The three strains were shown to be different from each other based on physiologic and metabolic properties. Even though analysis of membrane fatty acids did not result in identification of the organisms, the fatty acid profiles were found to be similar to those of Azoarcus species. Sequence analysis of 16S ribosomal DNA also indicated that the phenol-degrading isolates were closely related to members of the genus Azoarcus. The results of this study add three new members to the genus Azoarcus, which previously comprised only nitrogen-fixing species associated with plant roots and denitrifying toluene degraders.

  6. Isolation and characterization of phenol-degrading denitrifying bacteria

    SciTech Connect

    Schie, P.M. van; Young, L.Y.

    1998-07-01

    Phenol is a man-made as well as a naturally occurring aromatic compound and an important intermediate in the biodegradation of natural and industrial aromatic compounds. Whereas many microorganisms that are capable of aerobic phenol degradation have been isolated, only a few phenol-degrading anaerobic organisms have been described to date. In this study, three novel nitrate-reducing microorganisms that are capable of using phenol as a sole source of carbon were isolated and characterized. Phenol-degrading denitrifying pure cultures were obtained by enrichment culture from anaerobic sediments obtained from three different geographic locations, the East River in New York, NY, a Florida orange grove, and a rain forest in Costa Rica. The three strains were shown to be different from each other based on physiologic and metabolic properties. Even though analysis of membrane fatty acids did not result in identification of the organisms, the fatty acid profiles were found to be similar to those of Azoarcus species. Sequence analysis of 16S ribosomal DNA also indicated that the phenol-degrading isolates were closely related to members of the genus Azoarcus. The results of this study add three new members to the genus Azoarcus, which previously comprised only nitrogen-fixing species associated with plant roots and denitrifying toluene degraders.

  7. The antagonism activity of bacteria isolated from potato cultivated soil.

    PubMed

    Mezaache-Aichour, S; Sayah, N; Zerroug, M M; Guechi, A

    2012-01-01

    Soil-borne fungal and bacterial root pathogens can cause serious losses to agricultural crops. Resistant plant varieties are not available for several soil-borne pathogens and chemical control is often insufficiently effective in soil. The enhancement of disease suppressive properties of soils will limit disease development, thus, being of great importance for sustainable agriculture as well as organic farming systems. The aim of this research is to find and identify suppressive soils in the Sétif's areas (potato field located in different regions of Sétif); this allows the selection of the indigenous soil bacteria that are able to develop several mechanisms of action related to biocontrol of phytopathogenic fungi affecting potato crops. Among 50 bacterial strains only 14 showed a wide range of antifungal action against the tested phytopathogenic fungi. With a range of inhibition percent from 0 to 92.30% especially Fusarium oxysporum f. sp. albedinis with 92% inhibition.

  8. Arsenic resistance and accumulation by two bacteria isolated from a natural arsenic contaminated site.

    PubMed

    Pandey, Neha; Bhatt, Renu

    2015-11-01

    Forty-three indigenous arsenic resistant bacteria were isolated from arsenic rich soil of Rajnandgaon district in the state of Chhattisgarh, India by enrichment culture technique. Among the isolates, two of the bacteria (As-9 and As-14) exhibited high resistance to As(V) [MIC ≥ 700 mM] and As(III) [MIC ≥ 10 mM] and were selected for further studies. Both these bacteria grew well in the presence of arsenic [20 mM As(V) and 5 mM As(III)], but the isolate As-14 strictly required arsenic for its survival and growth and was characterized as a novel arsenic dependent bacterium. The isolates contributed to 99% removal of arsenic from the growth medium which was efficiently accumulated in the cell. Quantitative estimation of arsenic through Atomic Absorption Spectrophotometer revealed that there was >60% accumulation of both As(V) and As(III) by the two isolates. Scanning Electron Microscopic analysis showed a fourfold increase in bacterial cell volume when grown in the presence of arsenic and the results of Transmission Electron Microscopy and energy-dispersive X-ray spectroscopy proved that such an alteration was due to arsenic accumulation. Such arsenic resistant bacteria with efficient accumulating property could be effectively applied in the treatment of arsenic contaminated water. PMID:26095615

  9. Identification of bacteria isolated from diseased Neungee mushroom, Sarcodon aspratus.

    PubMed

    Lee, Young Nam; Koo, Chang-Duck

    2007-02-01

    As the first step in an investigation of the problem with quality deterioration seen in the Neungee mushroom (Sarcodon aspratus) due to bacterial overgrowth during its storage, an attempt to isolate bacterial strains was made using infected gills of Sarcodon aspratus. Five bacterial strains were isolated; one phototrophic cyanobacterial species and four heterotrophic Gram negative rods. The four heterotrophic bacterial isolates (strains P, S, R, and MK1) were subjected to identification based on biochemical characteristics using the Biolog system, cellular fatty acid analysis using the MIDI system, cytology by scanning microscopy, and 16s rDNA sequence analysis. A slow grower, the P strain (ca. 0.7 microm x 1.5 microm), which forms pink colonies on Tryptic Soy agar (TSA) and glucose minimal salt medium containing thiamine (MT medium), belongs to genus Methylobacterium, and is likely M. radiotolerans. The methanol-utilizing capacity of the P strain was confirmed by growth on methanol-supplemented medium as a sole carbon source. Both the S and R strains (ca. 0.5 microm x 0.8 microm) produced smooth and slightly rough white colonies, respectively, on TSA, MT, and potato dextrose (PD) agar are members of the Burkholderia cepacia complex. Although both strains showed some differences from each other in colony morphology, nitrogen fixation capacity, and denitrification, they were considered to be Burkholderia stabilis because their 16s rDNA sequences showed 99.93% similarity with those of B. stabilis LMG 14294T (NCBI AF 148554). The MK1 strain, a rod-shaped bacterium with a tapered end (ca. 0.6 microm x 1.8 microm), produces a copious mucoid substance on MT and PD agar, but not on TSA. Despite extensive identification studies, the M strain is not currently identifiable, which suggests that it is a novel bacterium. PMID:17304616

  10. Isolation of acetic, propionic and butyric acid-forming bacteria from biogas plants.

    PubMed

    Cibis, Katharina Gabriela; Gneipel, Armin; König, Helmut

    2016-02-20

    In this study, acetic, propionic and butyric acid-forming bacteria were isolated from thermophilic and mesophilic biogas plants (BGP) located in Germany. The fermenters were fed with maize silage and cattle or swine manure. Furthermore, pressurized laboratory fermenters digesting maize silage were sampled. Enrichment cultures for the isolation of acid-forming bacteria were grown in minimal medium supplemented with one of the following carbon sources: Na(+)-dl-lactate, succinate, ethanol, glycerol, glucose or a mixture of amino acids. These substrates could be converted by the isolates to acetic, propionic or butyric acid. In total, 49 isolates were obtained, which belonged to the phyla Firmicutes, Tenericutes or Thermotogae. According to 16S rRNA gene sequences, most isolates were related to Clostridium sporosphaeroides, Defluviitoga tunisiensis and Dendrosporobacter quercicolus. Acetic, propionic or butyric acid were produced in cultures of isolates affiliated to Bacillus thermoamylovorans, Clostridium aminovalericum, Clostridium cochlearium/Clostridium tetani, C. sporosphaeroides, D. quercicolus, Proteiniborus ethanoligenes, Selenomonas bovis and Tepidanaerobacter sp. Isolates related to Thermoanaerobacterium thermosaccharolyticum produced acetic, butyric and lactic acid, and isolates related to D. tunisiensis formed acetic acid. Specific primer sets targeting 16S rRNA gene sequences were designed and used for real-time quantitative PCR (qPCR). The isolates were physiologically characterized and their role in BGP discussed.

  11. Isolation and characterization of endophytic bacteria from the nickel hyperaccumulator plant Alyssum bertolonii.

    PubMed

    Barzanti, Rita; Ozino, Francesca; Bazzicalupo, Marco; Gabbrielli, Roberto; Galardi, Francesca; Gonnelli, Cristina; Mengoni, Alessio

    2007-02-01

    We report the isolation and characterization of endophytic bacteria, endemic to serpentine outcrops of Central Italy, from a nickel hyperaccumulator plant, Alyssum bertolonii Desv. (Brassicaceae). Eighty-three endophytic bacteria were isolated from roots, stems, and leaves of A. bertolonii and classified by restriction analysis of 16S rDNA (ARDRA) and partial 16S rDNA sequencing in 23 different taxonomic groups. All isolates were then screened for siderophore production and for resistance to heavy metals. One isolate representative of each ARDRA group was then tested for plant tissue colonization ability in sterile culture. Obtained results pointed out that, despite the high concentration of heavy metals present in its tissues, A. bertolonii harbors an endophytic bacterial flora showing a high genetic diversity as well as a high level of resistance to heavy metals that could potentially help plant growth and Ni hyperaccumulation. PMID:17264998

  12. Butanol tolerance of carboxydotrophic bacteria isolated from manure composts.

    PubMed

    Pomaranski, Eric; Tiquia-Arashiro, Sonia M

    2016-08-01

    Carboxydotrophic bacteria (carboxydotrophs) have the ability to uptake carbon monoxide (CO) and synthesize butanol. The aims of this study were to determine the butanol tolerance and biological production of butanol carboxydotrophic strains. In this study, 11 carboxydotrophic strains were exposed to increasing n-butanol concentrations (1-3% vol/vol) to determine their effect on growth. Butanol production by the strains was quantified and the identity of the strains was elucidated using 16S rRNA sequencing. The carboxydotrophic strains possessed inherent tolerance to butanol and tolerated up to 3% n-butanol. Among the 11 strains, T1-16, M2-32 and M3-28 were the most tolerant to butanol. The 16S rRNA gene sequence of these strains was similar (99% nucleotide similarity) to the butanol-tolerant strains Bacillus licheniformis YP1A, Pediococcus acidilacti IMUA20068 and Enterococcus faecium IMAU60169, respectively. The carboxydotrophic strains screened in this study have two distinct features: (1) high tolerance to butanol and (2) natural production of low concentration of butanol from CO, which distinguish them from other screened butanol-tolerant strains. The butanol tolerance of these carboxydotrophic strains makes them ideal for genetic studies, particularly the molecular mechanisms that enable them to survive such hostile environmental conditions and the identification of genes that confer tolerance to butanol. PMID:26809187

  13. Phylogenetic and physiological diversity of sulphate-reducing bacteria isolated from a salt marsh sediment.

    PubMed

    Rooney-Varga, J N; Genthner, B R; Devereux, R; Willis, S G; Friedman, S D; Hines, M E

    1998-12-01

    The phylogenetic and physiological diversity of sulphate-reducing bacteria inhabiting a salt marsh rhizosphere were investigated. Sulphate-reducing bacteria were isolated from a salt marsh rhizosphere using enrichment cultures with electron donors thought to be prevalent in the rhizosphere of Spartina alterniflora. The relationship between phylogeny and nutritional characteristics of 10 strains was investigated. None of the isolates had 16S rRNA sequences identical to other delta subclass sulphate-reducers, sharing 85.3 to 98.1% sequence similarity with 16S rRNA sequences of their respective closest relatives. Phylogenetic analysis placed two isolates, obtained with ethanol as an electron donor, within the Desulfovibrionaceae. Seven isolates, obtained with acetate, butyrate, propionate, or benzoate, were placed within the Desulfobacteriaceae. One isolate, obtained with butyrate, fell within the Desulfobulbus assemblage, which is currently considered part of the Desulfobacteriaceae family. However, due to the phylogenetic breadth and physiological traits of this group, we propose that it be considered a new family, the "Desulfobulbusaceae." The isolates utilised an array of electron donors similar to their closest relatives with a few exceptions. As a whole, the phylogenetic and physiological data indicate isolation of several sulphate-reducing bacteria which might be considered as new species and representative of new genera. Comparison of the Desulfobacteriaceae isolates' 16S rRNA sequences to environmental clones originating from the same study site revealed that none shared more than 86% sequence similarity. The results provide further insight into the diversity of sulphate-reducing bacteria inhabiting the salt marsh ecosystem, as well as supporting general trends in the phylogenetic coherence of physiological traits of delta Proteobacteria sulphate reducers.

  14. Microbiological study of pathogenic bacteria isolated from paediatric wound infections following the 2008 Wenchuan earthquake.

    PubMed

    Ran, Ying-Chun; Ao, Xiao-Xiao; Liu, Lan; Fu, Yi-Long; Tuo, Hui; Xu, Feng

    2010-05-01

    On 12 May 2008, the Wenchuan earthquake struck in Sichuan, China. Within 1 month after the earthquake, 98 injured children were admitted to the Children's Hospital of Chongqing Medical University. According to clinical manifestations, 50 children were diagnosed with wound infections. Wound secretions were cultured for bacteria. Pathogen distribution and drug resistance were analyzed. A total of 99 pathogens were isolated; 16 (16%) were Gram-positive bacteria and 81 (82%) were Gram-negative bacteria. The distribution of pathogens isolated within 1 month after the earthquake was different to the distribution of pathogens in 546 general hospitalized cases in the y before the earthquake. The pathogens most frequently isolated 1 month after the earthquake were Acinetobacter baumannii (27%), Enterobacter cloacae (18%) and Pseudomonas aeruginosa (13%). The pathogens most frequently isolated in the y prior to the earthquake were Escherichia coli (27%), Staphylococcus aureus (23%) and coagulase-negative staphylococci (9%). The rate of isolated drug-resistant bacteria was higher in the earthquake cases than in the general hospitalized cases. In the cases injured in the earthquake, the rates of isolation of methicillin-resistant Staphylococcus aureus and extended-spectrum beta-lactamase-producing E. cloacae, E. coli and Klebsiella pneumoniae were higher than in the cases from before the earthquake. Multidrug-resistant and pandrug-resistant A. baumannii were isolated at a higher rate in cases after the earthquake than in those before the earthquake. These changes in the spectrum of pathogens and in the drug resistance of the pathogens isolated following an earthquake will provide the basis for emergency treatment after earthquakes. PMID:20095936

  15. Evaluation of Malolactic Bacteria Isolated from Oregon Wines †

    PubMed Central

    Henick-Kling, T.; Sandine, W. E.; Heatherbell, D. A.

    1989-01-01

    Oregon is a cool wine-producing region where grapes characteristically contain high concentrations of organic acids. To reduce the natural acidity and increase the microbiological stability and flavor complexity of the wine, malolactic fermentation is encouraged. In this study, strains of Leuconostoc oenos indigenous to Oregon wines were evaluated for their suitability to conduct malolactic fermentation in Oregon wines. Tests determined the malolactic activity of the Oregon isolates in comparison with commercial strains ML-34, PSU-1, MLT-kli, and ens 44-40 under various temperature and pH conditions. Sensitivities to sulfur dioxide, ethanol, and fumaric acid also were determined. Two Oregon strains, Er-1a and Ey-2d, were selected for commercial winemaking tests because they had greater malolactic activity under conditions of low pH (3.0) and low temperature (15 and 8°C), respectively. PMID:16347992

  16. New Approaches for Isolation of Previously Uncultivated Oral Bacteria

    PubMed Central

    Sizova, M. V.; Hohmann, T.; Hazen, A.; Paster, B. J.; Halem, S. R.; Murphy, C. M.; Panikov, N. S.

    2012-01-01

    A significant number of microorganisms from the human oral cavity remain uncultivated. This is a major impediment to the study of human health since some of the uncultivated species may be involved in a variety of systemic diseases. We used a range of innovations previously developed to cultivate microorganisms from the human oral cavity, focusing on anaerobic species. These innovations include (i) in vivo cultivation to specifically enrich for species actively growing in the oral cavity (the “minitrap” method), (ii) single-cell long-term cultivation to minimize the effect of fast-growing microorganisms, and (iii) modifications of conventional enrichment techniques, using media that did not contain sugar, including glucose. To enable cultivation of obligate anaerobes, we maintained strict anaerobic conditions in most of our cultivation experiments. We report that, on a per cell basis, the most successful recovery was achieved using minitrap enrichment (11%), followed by single-cell cultivation (3%) and conventional plating (1%). Taxonomically, the richest collection was obtained using the single-cell cultivation method, followed by minitrap and conventional enrichment, comprising representatives of 13, 9, and 4 genera, respectively. Interestingly, no single species was isolated by all three methods, indicating method complementarity. An important result is the isolation and maintenance in pure culture of 10 strains previously only known by their molecular signatures, as well as representatives of what are likely to be three new microbial genera. We conclude that the ensemble of new methods we introduced will likely help close the gap between cultivated and uncultivated species from the human oral cavity. PMID:22057871

  17. Characterization and transferability of class 1 integrons in commensal bacteria isolated from farm and nonfarm environments.

    PubMed

    Yang, Hua; Byelashov, Oleksandr A; Geornaras, Ifigenia; Goodridge, Lawrence D; Nightingale, Kendra K; Belk, Keith E; Smith, Gary C; Sofos, John N

    2010-12-01

    This study assessed the distribution of class 1 integrons in commensal bacteria isolated from agricultural and nonfarm environments, and the transferability of class 1 integrons to pathogenic bacteria. A total of 26 class 1 integron-positive isolates were detected in fecal samples from cattle operations and a city park, water samples from a beef ranch and city lakes, and soil, feed (unused), manure, and compost samples from a dairy farm. Antimicrobial susceptibility testing of class 1 integron-positive Enterobacteriaceae isolates from city locations displayed multi-resistance to 12-13 out of the 22 antibiotics tested, whereas class 1 integron-positive Enterobacteriaceae isolates from cattle operations only displayed tetracycline resistance. Most class 1 integrons had one gene cassette belonging to the aadA family that confers resistance to streptomycin and spectinomycin. One isolate from a dog fecal sample collected from a city dog park transferred its class 1 integron to a strain of Escherichia coli O157:H7 at a frequency of 10(-7) transconjugants/donor by in vitro filter mating experiments under the stated laboratory conditions. Due to the numerous factors that may affect the transferability testing, further investigation using different methodologies may be helpful to reveal the transferability of the integrons from other isolates. The presence of class 1 integrons among diverse commensal bacteria from agricultural and nonfarm environments strengthens the possible role of environmental commensals in serving as reservoirs of antibiotic resistance genes.

  18. Ice nucleation activity of bacteria isolated from cloud water

    NASA Astrophysics Data System (ADS)

    Joly, Muriel; Attard, Eléonore; Sancelme, Martine; Deguillaume, Laurent; Guilbaud, Caroline; Morris, Cindy E.; Amato, Pierre; Delort, Anne-Marie

    2013-05-01

    Some Gamma-Proteobacteria can catalyze ice formation thereby potentially contributing to the induction of precipitation in supercooled clouds and subsequently to bacterial deposition. Forty-four bacterial strains from cloud water were screened for their capacity to induce freezing. Seven strains (16%) were active at -8 °C or warmer and were identified as Pseudomonas syringae, Xanthomonas spp. and Pseudoxanthomonas sp. Phylogenetic analysis revealed that the P. syringae strains in clouds at the Puy de Dôme belonged to clades that are among the most infrequently detected in the environment, while widespread clades were absent suggesting some extent of selection or unusual biogeography of the bacteria at the sampling site. Three strains induced freezing at -3 °C while the others nucleated ice at -4 °C to -6 °C. The freezing profiles revealed that the peaks of activity were centered around -3.5 °C, -5 °C and/or -8.5 °C depending on the strain. The frequency of ice-nuclei (IN) per cell at -6 °C was generally below 0.5% and reached up to 4.2% in one strain. We estimated that clouds influenced by vegetated areas would carry between less than 1 and ˜500 bacterial IN mL-1 of water active between -3 °C and -10 °C depending on the season. These data will contribute to modeling the impact of bacterial IN on precipitation at regional scales.

  19. Multidrug resistant bacteria isolated from cockroaches in long-term care facilities and nursing homes.

    PubMed

    Pai, Hsiu-Hua

    2013-01-01

    Residents in long-term care facilities and nursing homes have a relative higher risk for infections. The nocturnal and filthy habits of cockroaches may be ideal disseminators of pathogenic microorganisms in these institutions. This study was designed to determine the infestation and vector potential of cockroaches under this institutional environment. Cockroaches were collected from 69 long-term care facilities and nursing homes in Kaohsiung City. Risk factors related to cockroach infestation were determined by questionnaire survey. In addition, bacteria were isolated and identified from the alimentary tract and external surface of these insects. Antibiotic resistances of these microorganisms were then determined. Cockroach infestation was found in 45 (65.2%) institutions and 558 cockroaches (119 Periplaneta americana and 439 Blattella germanica) were collected. A significant association was found between cockroach infestation and indoor environmental sanitation. From 250 adult cockroaches, 38 species of gram-negative bacteria, 20 species of glucose non-fermenter bacilli and 6 species of gram-positive bacteria were isolated. Moreover, antibiotic resistances were found among the bacteria isolated. These findings indicate that cockroaches have the potential in transmitting pathogenic bacteria with multidrug resistances in long-term care facilities and nursing homes.

  20. Isolation and Characterization of Diverse Halobenzoate-Degrading Denitrifying Bacteria from Soils and Sediments

    PubMed Central

    Song, Bongkeun; Palleroni, Norberto J.; Häggblom, Max M.

    2000-01-01

    Denitrifying bacteria capable of degrading halobenzoates were isolated from various geographical and ecological sites. The strains were isolated after initial enrichment on one of the monofluoro-, monochloro-, or monobromo-benzoate isomers with nitrate as an electron acceptor, yielding a total of 33 strains isolated from the different halobenzoate-utilizing enrichment cultures. Each isolate could grow on the selected halobenzoate with nitrate as the terminal electron acceptor. The isolates obtained on 2-fluorobenzoate could use 2-fluorobenzoate under both aerobic and denitrifying conditions, but did not degrade other halobenzoates. In contrast, the 4-fluorobenzoate isolates degraded 4-fluorobenzoate under denitrifying conditions only, but utilized 2-fluorobenzoate under both aerobic and denitrifying conditions. The strains isolated on either 3-chlorobenzoate or 3-bromobenzoate could use 3-chlorobenzoate, 3-bromobenzoate, and 2- and 4-fluorobenzoates under denitrifying conditions. The isolates were identified and classified on the basis of 16S rRNA gene sequence analysis and their cellular fatty acid profiles. They were placed in nine genera belonging to either the α-, β-, or γ-branch of the Proteobacteria, namely, Acidovorax, Azoarcus, Bradyrhizobium, Ochrobactrum, Paracoccus, Pseudomonas, Mesorhizobium, Ensifer, and Thauera. These results indicate that the ability to utilize different halobenzoates under denitrifying conditions is ubiquitously distributed in the Proteobacteria and that these bacteria are widely distributed in soils and sediments. PMID:10919805

  1. Genetic and phenotypic diversity of carbofuran-degrading bacteria isolated from agricultural soils.

    PubMed

    Shin, Dong-Hyeon; Kim, Dong-Uk; Seong, Chi-Nam; Song, Hong-Gyu; Ka, Jong-Ok

    2012-04-01

    Thirty-seven carbofuran-degrading bacteria were isolated from agricultural soils, and their genetic and phenotypic characteristics were investigated. The isolates were able to utilize carbofuran as a sole source of carbon and energy. Analysis of the 16S rRNA gene sequence indicated that the isolates were related to members of the genera Rhodococcus, Sphingomonas, and Sphingobium, including new types of carbofuran-degrading bacteria, Bosea and Microbacterium. Among the 37 isolates, 15 different chromosomal DNA patterns were obtained by polymerase chain reaction (PCR) amplification of repetitive extragenic palindromic (REP) sequences. Five of the 15 representative isolates were able to degrade carbofuran phenol, fenoxycarb, and carbaryl, in addition to carbofuran. Ten of the 15 representative isolates had 1 to 8 plasmids. Among the 10 plasmid-containing isolates, plasmid-cured strains were obtained from 5 strains. The cured strains could not degrade carbofuran and other pesticides anymore, suggesting that the carbofuran degradative genes were on the plasmid DNAs in these strains. When analyzed with PCR amplification and dot-blot hybridization using the primers targeting for the previously reported carbofuran hydrolase gene (mcd), all of the isolates did not show any positive signals, suggesting that their carbofuran hydrolase genes had no significant sequence homology with the mcd gene.

  2. How-to-Do-It: A Simple DNA Isolation Technique Using Halophilic Bacteria.

    ERIC Educational Resources Information Center

    Guilfoile, Patrick

    1989-01-01

    Described is a simple technique for isolating DNA from halophilic bacteria. Materials, procedure, and additional experiments are outlined. It is stated that the DNA obtained will be somewhat contaminated with cellular proteins and RNA. Offers a procedure for greater purification. (RT)

  3. Cellulolytic and proteolytic ability of bacteria isolated from gastrointestinal tract and composting of a hippopotamus.

    PubMed

    da Cruz Ramos, Geomárcia Feitosa; Ramos, Patricia Locosque; Passarini, Michel Rodrigo Zambrano; Vieira Silveira, Marghuel A; Okamoto, Débora Noma; de Oliveira, Lilian Caroline Gonçalves; Zezzo, Larissa Vieira; Marem, Alyne; Santos Rocha, Rafael Costa; da Cruz, João Batista; Juliano, Luiz; de Vasconcellos, Suzan Pantaroto

    2016-03-01

    The bioprospection for cellulase and protease producers is a promise strategy for the discovery of potential biocatalysts for use in hydrolysis of lignocellulosic materials as well as proteic residues. These enzymes can increment and turn viable the production of second generation ethanol from different and alternative sources. In this context, the goal of this study was the investigation of cellulolytic and proteolytic abilities of bacteria isolated from the gastrointestinal tract of a hippopotamus as well as from its composting process. It is important to highlight that hippopotamus gastrointestinal samples were a non-typical sources of efficient hydrolytic bacteria with potential for application in biotechnological industries, like biofuel production. Looking for this, a total of 159 bacteria were isolated, which were submitted to qualitative and quantitative enzymatic assays. Proteolytic analyzes were conducted through the evaluation of fluorescent probes. Qualitative assays for cellulolytic abilities revealed 70 positive hits. After quantitative analyzes, 44 % of these positive hits were selected, but five (5) strains showed cellulolytic activity up to 11,8 FPU/mL. Regarding to proteolytic activities, six (6) strains showed activity above 10 %, which overpassed results described in the literature. Molecular analyzes based on the identification of 16S rDNA, revealed that all the selected bacterial isolates were affiliated to Bacillus genus. In summary, these results strongly indicate that the isolated bacteria from a hippopotamus can be a potential source of interesting biocatalysts with cellulolytic and proteolytic activities, with relevance for industrial applications.

  4. Cellulolytic and proteolytic ability of bacteria isolated from gastrointestinal tract and composting of a hippopotamus.

    PubMed

    da Cruz Ramos, Geomárcia Feitosa; Ramos, Patricia Locosque; Passarini, Michel Rodrigo Zambrano; Vieira Silveira, Marghuel A; Okamoto, Débora Noma; de Oliveira, Lilian Caroline Gonçalves; Zezzo, Larissa Vieira; Marem, Alyne; Santos Rocha, Rafael Costa; da Cruz, João Batista; Juliano, Luiz; de Vasconcellos, Suzan Pantaroto

    2016-03-01

    The bioprospection for cellulase and protease producers is a promise strategy for the discovery of potential biocatalysts for use in hydrolysis of lignocellulosic materials as well as proteic residues. These enzymes can increment and turn viable the production of second generation ethanol from different and alternative sources. In this context, the goal of this study was the investigation of cellulolytic and proteolytic abilities of bacteria isolated from the gastrointestinal tract of a hippopotamus as well as from its composting process. It is important to highlight that hippopotamus gastrointestinal samples were a non-typical sources of efficient hydrolytic bacteria with potential for application in biotechnological industries, like biofuel production. Looking for this, a total of 159 bacteria were isolated, which were submitted to qualitative and quantitative enzymatic assays. Proteolytic analyzes were conducted through the evaluation of fluorescent probes. Qualitative assays for cellulolytic abilities revealed 70 positive hits. After quantitative analyzes, 44 % of these positive hits were selected, but five (5) strains showed cellulolytic activity up to 11,8 FPU/mL. Regarding to proteolytic activities, six (6) strains showed activity above 10 %, which overpassed results described in the literature. Molecular analyzes based on the identification of 16S rDNA, revealed that all the selected bacterial isolates were affiliated to Bacillus genus. In summary, these results strongly indicate that the isolated bacteria from a hippopotamus can be a potential source of interesting biocatalysts with cellulolytic and proteolytic activities, with relevance for industrial applications. PMID:26931430

  5. Isolation and characterization of plant growth promoting endophytic diazotrophic bacteria from Korean rice cultivars.

    PubMed

    Ji, Sang Hye; Gururani, Mayank Anand; Chun, Se-Chul

    2014-01-20

    We have isolated 576 endophytic bacteria from the leaves, stems, and roots of 10 rice cultivars and identified 12 of them as diazotrophic bacteria using a specific primer set of nif gene. Through 16S rDNA sequence analysis, nifH genes were confirmed in the two species of Penibacillus, three species of Microbacterium, three Bacillus species, and four species of Klebsiella. Rice seeds treated with these plant growth-promoting bacteria (PGPB) showed improved plant growth, increased height and dry weight and antagonistic effects against fungal pathogens. In addition, auxin and siderophore producing ability, and phosphate solubilizing activity were studied for the possible mechanisms of plant growth promotion. Among 12 isolates tested, 10 strains have shown higher auxin producing activity, 6 isolates were confirmed as strains with high siderophore producing activity while 4 isolates turned out to have high phosphate-solubilizing activity. These results strongly suggest that the endophytic diazotrophic bacteria characterized in this study could be successfully used to promote plant growth and inducing fungal resistance in plants.

  6. Epibiotic Vibrio luminous bacteria isolated from some hydrozoa and bryozoa species.

    PubMed

    Stabili, L; Gravili, C; Tredici, S M; Piraino, S; Talà, A; Boero, F; Alifano, P

    2008-11-01

    Luminous bacteria are isolated from both Hydrozoa and Bryozoa with chitinous structures on their surfaces. All the specimens of the examined hydroid species (Aglaophenia kirchenpaueri, Aglaophenia octodonta, Aglaophenia tubiformis, Halopteris diaphana, Plumularia setacea, Ventromma halecioides), observed under blue light excitation, showed a clear fluorescence on the external side of the perisarc (chitinous exoskeleton) around hydrocladia. In the bryozoan Myriapora truncata, luminous bacteria are present on the chitinous opercula. All the isolated luminous bacteria were identified on the basis of both phenotypic and genotypic analysis. The isolates from A. tubiformis and H. diaphana were unambiguously assigned to the species Vibrio fischeri. In contrast, the isolates from the other hydroids, phenotypically assigned to the species Vibrio harveyi, were then split into two distinct species by phylogenetic analysis of 16S rRNA gene sequences and DNA-DNA hybridization experiments. Scanning electron microscopy analysis and results of culture-based and culture-independent approaches enabled us to establish that luminous vibrios represent major constituents of the bacterial community inhabiting the A. octodonta surface suggesting that the interactions between luminous bacteria and the examined hydrozoan and bryozoan species are highly specific. These interactions might have epidemiological as well as ecological implications because of the opportunistic pathogenicity of luminous Vibrio species for marine organisms and the wide-distribution of the hydrozoan and bryozoan functioning as carriers.

  7. Isolation, characterization and evaluation of probiotic lactic acid bacteria for potential use in animal production.

    PubMed

    García-Hernández, Yaneisy; Pérez-Sánchez, Tania; Boucourt, Ramón; Balcázar, José L; Nicoli, Jacques R; Moreira-Silva, João; Rodríguez, Zoraya; Fuertes, Héctor; Nuñez, Odalys; Albelo, Nereyda; Halaihel, Nabil

    2016-10-01

    In livestock production, lactic acid bacteria (LAB) are the most common microorganisms used as probiotics. For such use, these bacteria must be correctly identified and characterized to ensure their safety and efficiency. In the present study, LAB were isolated from broiler excreta, where a fermentation process was used. Nine among sixteen isolates were identified by biochemical and molecular (sequencing of the 16S rRNA gene) methods as Lactobacillus crispatus (n=1), Lactobacillus pentosus (n=1), Weissella cibaria (n=1), Pediococcus pentosaceus (n=2) and Enterococcus hirae (n=4). Subsequently, these bacteria were characterized for their growth capabilities, lactic acid production, acidic pH and bile salts tolerance, cell surface hydrophobicity, antimicrobial susceptibility and antagonistic activity. Lactobacillus pentosus strain LB-31, which showed the best characteristics, was selected for further analysis. This strain was administered to broilers and showed the ability of modulating the immune response and producing beneficial effects on morpho-physiological, productive and health indicators of the animals.

  8. Efficacy of Locally Isolated Lactic Acid Bacteria Against Antibiotic-Resistant Uropathogens

    PubMed Central

    Manzoor, Asma; Ul-Haq, Ikram; Baig, Shahjhan; Qazi, Javed Iqbal; Seratlic, Sanja

    2016-01-01

    Background: Antibiotic resistance represents a serious global health threat to public health, so infections such as pneumonia and urinary tract infection (UTI) are becoming harder to treat. Therefore, it is necessary to develop an action plan to restrain the problem of antibiotic resistance. One approach in UTI control could be the use of lactobacilli because these indigenous inhabitants in human intestine have been found to play an important role in protecting the host from various infections. Objectives: We sought to check the efficacy of locally isolated Lactobacillus species to eradicate antibiotic-resistant pathogenic bacteria causing UTI. Materials and Methods: Lactic acid bacteria isolated from spoiled fruits and vegetables and grown in MRS medium were screened against multi-drug-resistant Candida albicans, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and Enterococcus fecalis. Results: Fifty-four lactic acid bacteria were isolated from spoiled fruits and vegetables, of which 11 Gram-positive and catalase-negative Lactobacillus isolates were identified by carbohydrate assimilation profiles as Lactobacillus acidophilus, L. paracasei, L. delbrueckii, L. casei, L. helveticus, L. brevis, L. salivarius, L. fermentum, L. rhamnosus, L. animalis, and L. plantarum. The latter organism had the highest abundance of all the samples, so its isolates were also verified through 16S rRNA gene sequencing. The isolated Lactobacilli were screened against multi-drug-resistant uropathogens, viz. C. albicans, P. aeruginosa, K. pneumoniae, E. fecalis, and E. coli. The growth inhibition zone (GIZ) was over 10 mm against all the uropathogenic test organisms, where L. fermentum and L. plantarum strains demonstrated remarkable inhibitory activities against E. coli and E. faecalis, with a GIZ up to 28 mm. The susceptibility test to 16 antibiotics showed multidrug resistance (3 to 5 antibiotics) among all the tested uropathogens. Conclusions: The obtained results

  9. Gram-positive bacteria of marine origin: a numerical taxonomic study on Mediterranean isolates.

    PubMed

    Ortigosa, M; Garay, E; Pujalte, M J

    1997-12-01

    A numerical taxonomic study was performed on 65 Gram-positive wild strains of heterotrophic, aerobic, marine bacteria, and 9 reference strains. The isolates were obtained from oysters and seawater sampled monthly over one year, by direct plating on Marine Agar. The strains were characterized by 96 morphological, biochemical, physiological and nutritional tests. Clustering yielded 13 phena at 0.62 similarity level (Sl coefficient). Only one of the seven phena containing wild isolates could be identified (Bacillus marinus). A pronounced salt requirement was found in most isolates.

  10. Isolation and identification of thermo-acidophilic bacteria from orchards in china.

    PubMed

    Wang, Ying; Yue, Tianli; Yuan, Yahong; Gao, Zhenpeng

    2010-02-01

    Eight strains of thermo-acidophilic bacteria have been isolated from apple orchards in Shaanxi Province, China. The isolated strains were identified at the species level by comparing 16S rRNA gene sequences. It was found that all strains could be assigned to two genera. The strain YL-5 belonged to Alicyclobacillus, and other isolates belonged to Bacillus. The enzymatic patterns by the API ZYM system showed very significant differences between 12 strains of Alicyclobacillus and 8 strains of Bacillus. The ability of guaiacol production varied among different strains.

  11. Innovative Approaches Using Lichen Enriched Media to Improve Isolation and Culturability of Lichen Associated Bacteria

    PubMed Central

    Biosca, Elena G.; Flores, Raquel; Santander, Ricardo D.; Díez-Gil, José Luis; Barreno, Eva

    2016-01-01

    Lichens, self-supporting mutualistic associations between a fungal partner and one or more photosynthetic partners, also harbor non-photosynthetic bacteria. The diversity and contribution of these bacteria to the functioning of lichen symbiosis have recently begun to be studied, often by culture-independent techniques due to difficulties in their isolation and culture. However, culturing as yet unculturable lichenic bacteria is critical to unravel their potential functional roles in lichen symbiogenesis, to explore and exploit their biotechnological potential and for the description of new taxa. Our objective was to improve the recovery of lichen associated bacteria by developing novel isolation and culture approaches, initially using the lichen Pseudevernia furfuracea. We evaluated the effect of newly developed media enriched with novel lichen extracts, as well as the influence of thalli washing time and different disinfection and processing protocols of thalli. The developed methodology included: i) the use of lichen enriched media to mimic lichen nutrients, supplemented with the fungicide natamycin; ii) an extended washing of thalli to increase the recovery of ectolichenic bacteria, thus allowing the disinfection of thalli to be discarded, hence enhancing endolichenic bacteria recovery; and iii) the use of an antioxidant buffer to prevent or reduce oxidative stress during thalli disruption. The optimized methodology allowed significant increases in the number and diversity of culturable bacteria associated with P. furfuracea, and it was also successfully applied to the lichens Ramalina farinacea and Parmotrema pseudotinctorum. Furthermore, we provide, for the first time, data on the abundance of culturable ecto- and endolichenic bacteria that naturally colonize P. furfuracea, R. farinacea and P. pseudotinctorum, some of which were only able to grow on lichen enriched media. This innovative methodology is also applicable to other microorganisms inhabiting these

  12. Linear alkylbenzene sulfonate tolerance in bacteria isolated from sediment of tropical water bodies polluted with detergents.

    PubMed

    Eniola, Kehinde I T; Olayemi, Albert B

    2008-12-01

    The discharge of untreated detergent-bearing waste introduces linear alklcylbenzene sulfonates (LAS) to the aquatic environment. The surfactant persists in some streams and rivers in Nigeria, some is adsorbed to suspended materials and end in the sediment of the receiving water bodies. In this study, bacteria isolated from sediments of some tropical detergent-effluent-polluted streams were tested for tolerance to LAS using the media dilution technique. LAS-tolerance was indicated by growth of the bacteria in the presence of the surfactant. The pH, concentrations of surfactant, population of heterotrophic bacteria and population of LAS-tolerant bacteria in the sediments were determined. A direct relationship (r = 0.9124) was found between the alkaline conditions (pH= 8.2-12.0) and high surfactant concentrations (45-132 mg/g) in the sediment. The sediments harboured a high population and a wide variety of bacteria; the populations of viable heterotrophic bacteria (VHB: 2.9 x 10(5) to 1.2 x 10(7) cfu/g) and LAS tolerant bacteria (LTB: 1.5 x 10(4) to 1.2 x 10(6) cfu/g) had a direct relationship (r = 0.9500). An inverse relationship resulted between each of them and the concentration of surfactant in the sediment, r(VHB/LAS) = -0.9303 and r(LTB/LAS) = -0.9143, respectively. Twelve bacteria species were isolated from the sediment: Alcaligenes odorans, Bacillus subtilis, Burkholderia cepacia, Citrobacter freundii, Citrobacter diversus, Escherichia coli, Micrococcus luteus, Micrococcus albus, Pseudomonas putida, Pseudomonas stutzeri, Staphylococcus aureus and Streptococcusfaecalis. Most of them were adapted to the surfactant with their maximum acceptable concentrations ranging between 0.03 and >1.0% (w/v). The sediments could serve as source of adapted organisms which can be used in bio-treatment of LAS-bearing waste. PMID:19419067

  13. Innovative Approaches Using Lichen Enriched Media to Improve Isolation and Culturability of Lichen Associated Bacteria.

    PubMed

    Biosca, Elena G; Flores, Raquel; Santander, Ricardo D; Díez-Gil, José Luis; Barreno, Eva

    2016-01-01

    Lichens, self-supporting mutualistic associations between a fungal partner and one or more photosynthetic partners, also harbor non-photosynthetic bacteria. The diversity and contribution of these bacteria to the functioning of lichen symbiosis have recently begun to be studied, often by culture-independent techniques due to difficulties in their isolation and culture. However, culturing as yet unculturable lichenic bacteria is critical to unravel their potential functional roles in lichen symbiogenesis, to explore and exploit their biotechnological potential and for the description of new taxa. Our objective was to improve the recovery of lichen associated bacteria by developing novel isolation and culture approaches, initially using the lichen Pseudevernia furfuracea. We evaluated the effect of newly developed media enriched with novel lichen extracts, as well as the influence of thalli washing time and different disinfection and processing protocols of thalli. The developed methodology included: i) the use of lichen enriched media to mimic lichen nutrients, supplemented with the fungicide natamycin; ii) an extended washing of thalli to increase the recovery of ectolichenic bacteria, thus allowing the disinfection of thalli to be discarded, hence enhancing endolichenic bacteria recovery; and iii) the use of an antioxidant buffer to prevent or reduce oxidative stress during thalli disruption. The optimized methodology allowed significant increases in the number and diversity of culturable bacteria associated with P. furfuracea, and it was also successfully applied to the lichens Ramalina farinacea and Parmotrema pseudotinctorum. Furthermore, we provide, for the first time, data on the abundance of culturable ecto- and endolichenic bacteria that naturally colonize P. furfuracea, R. farinacea and P. pseudotinctorum, some of which were only able to grow on lichen enriched media. This innovative methodology is also applicable to other microorganisms inhabiting these

  14. Innovative Approaches Using Lichen Enriched Media to Improve Isolation and Culturability of Lichen Associated Bacteria.

    PubMed

    Biosca, Elena G; Flores, Raquel; Santander, Ricardo D; Díez-Gil, José Luis; Barreno, Eva

    2016-01-01

    Lichens, self-supporting mutualistic associations between a fungal partner and one or more photosynthetic partners, also harbor non-photosynthetic bacteria. The diversity and contribution of these bacteria to the functioning of lichen symbiosis have recently begun to be studied, often by culture-independent techniques due to difficulties in their isolation and culture. However, culturing as yet unculturable lichenic bacteria is critical to unravel their potential functional roles in lichen symbiogenesis, to explore and exploit their biotechnological potential and for the description of new taxa. Our objective was to improve the recovery of lichen associated bacteria by developing novel isolation and culture approaches, initially using the lichen Pseudevernia furfuracea. We evaluated the effect of newly developed media enriched with novel lichen extracts, as well as the influence of thalli washing time and different disinfection and processing protocols of thalli. The developed methodology included: i) the use of lichen enriched media to mimic lichen nutrients, supplemented with the fungicide natamycin; ii) an extended washing of thalli to increase the recovery of ectolichenic bacteria, thus allowing the disinfection of thalli to be discarded, hence enhancing endolichenic bacteria recovery; and iii) the use of an antioxidant buffer to prevent or reduce oxidative stress during thalli disruption. The optimized methodology allowed significant increases in the number and diversity of culturable bacteria associated with P. furfuracea, and it was also successfully applied to the lichens Ramalina farinacea and Parmotrema pseudotinctorum. Furthermore, we provide, for the first time, data on the abundance of culturable ecto- and endolichenic bacteria that naturally colonize P. furfuracea, R. farinacea and P. pseudotinctorum, some of which were only able to grow on lichen enriched media. This innovative methodology is also applicable to other microorganisms inhabiting these

  15. Isolation of Extended Spectrum β-lactamase (ESBL) Producing Bacteria from Urban Surface Waters in Malaysia

    PubMed Central

    Tissera, Shehani; Lee, Sui Mae

    2013-01-01

    Background: This was a preliminary study to test for the presence of multiple antibiotic-resistant extended spectrum β-lactamase (ESBL) producing bacteria in Malaysian urban surface waters. Although the literature review revealed several published papers on clinical ESBL isolates in Malaysia, none were found on ESBL isolates obtained from local surface waters Methods: Isolated bacterial species were tested for resistance to cefotaxime, amoxicillin/clavulanate and aztreonam, and susceptibility to imipenem and meropenem using antibiotic susceptibility testing (AST) by disc diffusion. This served as a screening step to detect bacteria that could be potential ESBL species. 16S ribose ribonucleic acid (rRNA) polymerase chain reaction (PCR) testing with two clusters of bla (β-lactamase) gene primers was used to test for the bla genes CTX-M (Groups 1, 2, 9), OXA-1, SHV and TEM. Results: A total of 19 isolates were found, possessing at least one of the bla genes tested for. There was a relatively high occurrence of CTX-M genes (84.2%) among these, followed by TEM genes (47.4%). The isolates were identified as Enterobacteriaceae (89.5%), predominantly Escherichia coli and Klebsiella pneumoniae. Conclusion: There appears to be a high occurrence of ESBL-bacteria in local surface waters, among these being opportunistic pathogens. The persistence and spread of these species in the environment poses a threat to exposed human populations. PMID:23966820

  16. Screening and isolation of halophilic bacteria producing extracellular hydrolyses from Howz Soltan Lake, Iran.

    PubMed

    Rohban, R; Amoozegar, Mohammad Ali; Ventosa, A

    2009-03-01

    Screening of bacteria from different areas of Howz Soltan playa, a hypersaline lake in the central desert zone of Iran, led to the isolation of 231 moderately halophilic bacteria, which were able to grow optimally in media with 5-15% of salt, and 49 extremely halophilic microorganisms that required 20-25% of salt for optimal growth. These isolates produced a great variety of extracellular hydrolytic enzymes. A total of 195, 177, 100, 95, 92, 68, 65, 33, and 28 strains produced lipases, amylases, proteases, inulinases, xylanases, cellulases, pullulanases, DNases, and pectinases, respectively. In comparison with gram-negative bacteria, the gram-positive halophilic rods, showed more hydrolytic activities. Several combined activities were showed by some of these isolates. One strain presented 9 hydrolytic activities, 4 strains presented 8 hydrolytic activities, 10 strains presented 7 hydrolytic activities and 29 strains presented 6 hydrolytic activities. No halophilic isolate without hydrolytic activity has been found in this study. According to their phenotypic characteristics and comparative partial 16S rRNA sequence analysis, the halophilic strains were identified as members of the genera: Salicola, Halovibrio, Halomonas, Oceanobacillus, Thalassobacillus, Halobacillus, Virgibacillus, Gracilibacillus, Salinicoccus, and Piscibacillus. Most lipase and DNase producers were members of the genera Gracilibacillus and Halomonas, respectively, whereas most of the isolates able to produce hydrolytic enzymes such as amylase, protease, cellulose (CMCase) and inulinase, belonged to gram-positive genera, like Gracilibacillus, Thalassobacillus, Virgibacillus, and Halobacillus. PMID:19037673

  17. The antimicrobial efficacy of silver on antibiotic-resistant bacteria isolated from burn wounds.

    PubMed

    Percival, Steven L; Thomas, John; Linton, Sara; Okel, Tyler; Corum, Linda; Slone, Will

    2012-10-01

    The antibiotic-resistant bacteria are a major concern to wound care because of their ability to resist many of the antibiotics used today to treat infections. Consequently, other antimicrobials, in particular ionic silver, are considered ideal topical agents for effectively helping to manage and prevent local infections. Little is known about the antimicrobial efficacy of ionic silver on antibiotic-resistant bacteria at different pH values. Consequently, in this study our aim was to evaluate the effect of pH on the antimicrobial efficacy of a silver alginate (SA) and a silver carboxymethyl cellulose (SCMC) dressing on antibiotic-resistant bacteria isolated from burn patients. Forty-nine antibiotic-resistant bacteria, including Vancomycin-resistant Enterococcus faecium, meticillin-resistant Staphylococcus aureus, multidrug-resistant (MDR) Pseudomonas aeruginosa, MDR Vibrio sp, MDR Stenotrophomonas maltophilia, extended-spectrum ß-lactamase (ESBL) producing Salmonella sp, ESBL producing Klebsiella pneumoniae, ESBL producing Proteus mirabilis, ESBL producing Escherichia coli and MDR Acinetobacter baumannii, routinely isolated from burn wounds were used in the study and evaluated for their susceptibility to two silver containing wound dressings using a standardised antimicrobial efficacy screening assay [corrected zone of inhibition (CZOI)]. The mean overall CZOI for the Gram-positive isolates at a pH of 5·5 were very similar for both dressings. A mean CZOI of 5 mm was recorded for the SCMC dressing, which was slightly higher, at 5·4 mm for the SA dressing. At a pH of 7·0 both dressings, in general, showed a similar activity. However, at a pH of 8·5 the mean CZOI of the SCMC dressing was found to be significantly (P < 0·05) higher than the SA dressing for a select number of isolates. The mean overall CZOI for the Gram-negative bacteria followed a similar pattern as observed with the Gram-positive bacteria. Susceptibility to silver ions did vary significantly

  18. The antimicrobial efficacy of silver on antibiotic-resistant bacteria isolated from burn wounds.

    PubMed

    Percival, Steven L; Thomas, John; Linton, Sara; Okel, Tyler; Corum, Linda; Slone, Will

    2012-10-01

    The antibiotic-resistant bacteria are a major concern to wound care because of their ability to resist many of the antibiotics used today to treat infections. Consequently, other antimicrobials, in particular ionic silver, are considered ideal topical agents for effectively helping to manage and prevent local infections. Little is known about the antimicrobial efficacy of ionic silver on antibiotic-resistant bacteria at different pH values. Consequently, in this study our aim was to evaluate the effect of pH on the antimicrobial efficacy of a silver alginate (SA) and a silver carboxymethyl cellulose (SCMC) dressing on antibiotic-resistant bacteria isolated from burn patients. Forty-nine antibiotic-resistant bacteria, including Vancomycin-resistant Enterococcus faecium, meticillin-resistant Staphylococcus aureus, multidrug-resistant (MDR) Pseudomonas aeruginosa, MDR Vibrio sp, MDR Stenotrophomonas maltophilia, extended-spectrum ß-lactamase (ESBL) producing Salmonella sp, ESBL producing Klebsiella pneumoniae, ESBL producing Proteus mirabilis, ESBL producing Escherichia coli and MDR Acinetobacter baumannii, routinely isolated from burn wounds were used in the study and evaluated for their susceptibility to two silver containing wound dressings using a standardised antimicrobial efficacy screening assay [corrected zone of inhibition (CZOI)]. The mean overall CZOI for the Gram-positive isolates at a pH of 5·5 were very similar for both dressings. A mean CZOI of 5 mm was recorded for the SCMC dressing, which was slightly higher, at 5·4 mm for the SA dressing. At a pH of 7·0 both dressings, in general, showed a similar activity. However, at a pH of 8·5 the mean CZOI of the SCMC dressing was found to be significantly (P < 0·05) higher than the SA dressing for a select number of isolates. The mean overall CZOI for the Gram-negative bacteria followed a similar pattern as observed with the Gram-positive bacteria. Susceptibility to silver ions did vary significantly

  19. Spore-forming thermophilic sulfate-reducing bacteria isolated from North Sea oil field waters

    SciTech Connect

    Rosnes, J.T.; Torsvik, T.; Lien, T. )

    1991-08-01

    Thermophilic sulfate-reducing bacteria were isolated from oil field waters from oil production platforms in the Norwegian sector of the North Sea. Spore-forming rods dominated in the enrichments when lactate, propionate, butyrate, or a mixture of aliphatic fatty acids (C{sub 4} through C{sub 6}) was added as a carbon source and electron donor. Representative strains were isolated and characterized. The isolates grew autotrophically on H{sub 2}-CO{sub 2} and heterotrophically on fatty acids such as formate, propionate, butyrate, caproate, valerate, pyruvate, and lactate and on alcohols such as methanol, ethanol, and propanol. Sulfate, sulfite, and thiosulfate but not nitrate could be used as an electron acceptor. The temperature range for growth was 43 to 78C; the spores were extremely heat resistant and survived 131C for 20 min. The optimum pH was 7.0. The isolates grew well in salt concentrations ranging from 0 to 800 mmol of NaCl per liter. Sulfite reductase P582 was present, but cytochrome c and desulfoviridin were not found. Electron micrographs revealed a gram-positive cell organization. The isolates were classified as a Desulfotomaculum sp. on the basis of spore formation, general physiological characteristics, and submicroscopic organization. To detect thermophilic spore-forming sulfate-reducing bacteria in oil field water, polyvalent antisera raised against antigens from two isolates were used. These bacteria were shown to be widespread in oil field water from different platforms. The origin of thermophilic sulfate-reducing bacteria in the pore water of oil reservoirs is discussed.

  20. Biodegradation of crude oil by thermophilic bacteria isolated from a volcano island.

    PubMed

    Meintanis, Christos; Chalkou, Kalliopi I; Kormas, Konstantinos Ar; Karagouni, Amalia D

    2006-03-01

    One-hundred and fifty different thermophilic bacteria isolated from a volcanic island were screened for detection of an alkane hydroxylase gene using degenerated primers developed to amplify genes related to the Pseudomonas putida and Pseudomonas oleovorans alkane hydroxylases. Ten isolates carrying the alkJ gene were further characterized by 16s rDNA gene sequencing. Nine out of ten isolates were phylogenetically affiliated with Geobacillus species and one isolate with Bacillus species. These isolates were able to grow in liquid cultures with crude oil as the sole carbon source and were found to degrade long chain crude oil alkanes in a range between 46.64% and 87.68%. Results indicated that indigenous thermophilic hydrocarbon degraders of Bacillus and Geobacillus species are of special significance as they could be efficiently used for bioremediation of oil-polluted soil and composting processes. PMID:16456612

  1. Biochemical and physiological properties of alkaline phosphatases in five isolates of marine bacteria.

    PubMed Central

    Hassan, H M; Pratt, D

    1977-01-01

    The alkaline phosphatase activities of five unique isolates of marine bacteria were found to be associated with the periplasmic space; however, the enzymes from these isolates differed with respect to their repressibility, the apparent number of isoenzymes, the necessity for Mg2 for activity, and the conditions required for their release. With three of the isolates, the enzyme was released when cells that had been washed in 0.5 M NaCl were suspended in sucrose; however, with the other two isolates, one required the additional presence of tris(hydroxymethyl)aminomethane and the other required the presence of lysozyme and ethylenediaminetetraacetic acid. In two isolates the activity was constitutive, in two it was partially repressed, and in one it was completely repressed by inorganic phosphate. The repression of activity was associated with corresponding changes of activity bands as seen by acrylamide gel electrophoresis. Images PMID:845125

  2. Isolation and Characterization of Environmental Bacteria Capable of Extracellular Biosorption of Mercury

    PubMed Central

    François, Fabienne; Lombard, Carine; Guigner, Jean-Michel; Soreau, Paul; Brian-Jaisson, Florence; Martino, Grégory; Vandervennet, Manon; Garcia, Daniel; Molinier, Anne-Laure; Pignol, David; Peduzzi, Jean; Zirah, Séverine

    2012-01-01

    Accumulation of toxic metals in the environment represents a public health and wildlife concern. Bacteria resistant to toxic metals constitute an attractive biomass for the development of systems to decontaminate soils, sediments, or waters. In particular, biosorption of metals within the bacterial cell wall or secreted extracellular polymeric substances (EPS) is an emerging process for the bioremediation of contaminated water. Here the isolation of bacteria from soil, effluents, and river sediments contaminated with toxic metals permitted the selection of seven bacterial isolates tolerant to mercury and associated with a mucoid phenotype indicative of the production of EPS. Inductively coupled plasma-optical emission spectroscopy and transmission electron microscopy in conjunction with X-ray energy dispersive spectrometry revealed that bacteria incubated in the presence of HgCl2 sequestered mercury extracellularly as spherical or amorphous deposits. Killed bacterial biomass incubated in the presence of HgCl2 also generated spherical extracellular mercury deposits, with a sequestration capacity (40 to 120 mg mercury per g [dry weight] of biomass) superior to that of live bacteria (1 to 2 mg mercury per g [dry weight] of biomass). The seven strains were shown to produce EPS, which were characterized by Fourier transform-infrared (FT-IR) spectroscopy and chemical analysis of neutral-carbohydrate, uronic acid, and protein contents. The results highlight the high potential of Hg-tolerant bacteria for applications in the bioremediation of mercury through biosorption onto the biomass surface or secreted EPS. PMID:22156431

  3. Detection and isolation of plant-associated bacteria scavenging atmospheric molecular hydrogen.

    PubMed

    Kanno, Manabu; Constant, Philippe; Tamaki, Hideyuki; Kamagata, Yoichi

    2016-09-01

    High-affinity hydrogen (H2 )-oxidizing bacteria possessing group 5 [NiFe]-hydrogenase genes are important contributors to atmospheric H2 uptake in soil environments. Although previous studies reported the occurrence of a significant H2 uptake activity in vegetation, there has been no report on the identification and diversity of the responsible microorganisms. Here, we show the existence of plant-associated bacteria with the ability to consume atmospheric H2 that may be a potential energy source required for their persistence in plants. Detection of the gene hhyL - encoding the large subunit of group 5 [NiFe]-hydrogenase - in plant tissues showed that plant-associated high-affinity H2 -oxidizing bacteria are widely distributed in herbaceous plants. Among a collection of 145 endophytic isolates, seven Streptomyces strains were shown to possess hhyL gene and exhibit high- or intermediate-affinity H2 uptake activity. Inoculation of Arabidopsis thaliana (thale cress) and Oryza sativa (rice) seedlings with selected isolates resulted in an internalization of the bacteria in plant tissues. H2 uptake activity per bacterial cells was comparable between plant and soil, demonstrating that both environments are favourable for the H2 uptake activity of streptomycetes. This study first demonstrated the occurrence of plant-associated high-affinity H2 -oxidizing bacteria and proposed their potential contribution as atmospheric H2 sink.

  4. Isolation and characterization of polymeric galloyl-ester-degrading bacteria from a tannery discharge place.

    PubMed

    Franco, A R; Calheiros, C S C; Pacheco, C C; De Marco, P; Manaia, C M; Castro, P M L

    2005-11-01

    The culturable bacteria colonizing the rhizosphere of plants growing in the area of discharge of a tannery effluent were characterized. Relative proportions of aerobic, denitrifying, and sulfate-reducing bacteria were determined in the rhizosphere of Typha latifolia, Canna indica, and Phragmites australis. Aerobic bacteria were observed to be the most abundant group in the rhizosphere, and plant type did not seem to influence the abundance of the bacterial types analyzed. To isolate bacteria able to degrade polyphenols used in the tannery industry, enrichments were conducted under different conditions. Bacterial cultures were enriched with individual polyphenols (tannins Tara, Quebracho, or Mimosa) or with an undefined mixture of tannins present in the tannery effluent as carbon source. Cultures enriched with the effluent or Tara tannin were able to degrade tannic acid. Six bacterial isolates purified from these mixed cultures were able to use tannic acid as a sole carbon source in axenic culture. On the basis of 16S ribosomal DNA sequence analysis, these isolates were closely related to organisms belonging to the taxa Serratia, Stenotrophomonas maltophilia, Klebsiella oxytoca, Herbaspirillum chlorophenolicum, and Pseudomonas putida.

  5. Isolation of ice-nucleating active bacteria from the freeze-tolerant frog, Rana sylvatica.

    PubMed

    Lee, M R; Lee, R E; Strong-Gunderson, J M; Minges, S R

    1995-08-01

    Ice-nucleating active (INA) bacteria were isolated from the gut of field-collected freeze-tolerant wood frogs (Rana sylvatica) collected in winter. Thirteen strains of Pseudomonas fluorescens, four strains of Pseudomonas putida, and two strains of Enterobacter agglomerans had ice-nucleating activity. Each of the INA pseudomonad strains was psychrophilic. P. putida strains were differentiated from P. fluorescens strains by gelatinase, lecithinase, and lipase production. The maximum nucleation temperatures (Tmax) of aqueous suspensions (10(9) bacteria/ml) of the four INA P. putida strains ranged from -1.6 to -3.0 degrees C, which places this INA species among the most potent known biological nucleators. Ingestion of INA P. putida isolated from R. sylvatica by another freeze-tolerant frog. Pseudacris crucifer, decreased the capacity of this frog to supercool and remain unfrozen at -2 degrees C. This is the first report of INA bacteria isolated from a vertebrate, and suggests that, as part of the gut flora in some posthibernation freeze-tolerant wood frogs, these bacteria may play a role in enhancing winter survival by promoting ice nucleation at high subzero temperatures (ca. -2 degrees C). PMID:7656570

  6. Occurrence of antibiotic resistance genes in culturable bacteria isolated from Turkish trout farms and their local aquatic environment.

    PubMed

    Capkin, Erol; Terzi, Ertugrul; Altinok, Ilhan

    2015-05-21

    Antibiotic resistance and presence of the resistance genes were investigated in the bacteria isolated from water, sediment, and fish in trout farms. A total of 9 bacterial species, particularly Escherichia coli, were isolated from the water and sediment samples, and 12 species were isolated from fish. The antimicrobial test indicated the highest resistance against sulfamethoxazole and ampicillin in coliform bacteria, and against sulfamethoxazole, imipenem, and aztreonam in known pathogenic bacteria isolated from fish. The most effective antibiotics were rifampicin, chloramphenicol, and tetracycline. The multiple antibiotic resistance index was above the critical limit for almost all of the bacteria isolated. The most common antibiotic resistance gene was ampC, followed by tetA, sul2, blaCTX-M1, and blaTEM in the coliform bacteria. At least one resistance gene was found in 70.8% of the bacteria, and 66.6% of the bacteria had 2 or more resistance genes. Approximately 36.54% of the bacteria that contain plasmids were able to transfer them to other bacteria. The plasmid-mediated transferable resistance genes were ampC, blaCTX-M1, tetA, sul2, and blaTEM. These results indicate that the aquatic environment could play an important role in the development of antibiotic resistance and the dissemination of resistance genes among bacteria.

  7. Isolation and Characterization of Ethane, Propane, and Butane Consuming Bacteria from Marine Hydrocarbon Seeps

    NASA Astrophysics Data System (ADS)

    Redmond, M. C.; Valentine, D. L.

    2005-12-01

    Three strains of ethane, propane, or butane consuming bacteria were isolated from marine hydrocarbon seep sediments at Coal Oil Point, off shore Santa Barbara, CA. These three isolates (MR1, MR2 and MR3) were capable of growth at natural environmental temperatures and salinity. Isolate MR2 was capable of growth on ethane or propane as the sole carbon source, isolate MR4 on propane or butane, and isolate MR3 on ethane, propane, or butane. All three isolates were also able to grow on other carbon-containing molecules, including ethanol, 1-propanol, 2-propanol, acetate, butyrate, sucrose, and dextrose, and isolates MR3 and MR4 were able to grow on 1-butanol and 2-butanol. None showed significant growth with methane, methanol, or formate as the sole carbon source. 16S rDNA sequencing indicated that isolate MR2 was most closely related to the gamma-Proteobacterium Pseudomonas stutzeri, while isolates MR3 and MR4 were both Gram-positive and most similar to Rhodococcus wratislaviensis and Rhodococcus opacus, respectively. Compared to methanotrophs, relatively little is known about the organisms that consume the C2-C4 alkanes, but both our isolates and the previously described species appear to be capable of metabolizing a wide variety of carbon compounds, including several common pollutants. The growth of these hydrocarbon-oxidizing bacteria on other organic compounds raises the possibility that the abundance and distribution of organic matter might be expected to impact the oxidation of C2-C4 hydrocarbons. Additional studies will further characterize the range of metabolism, and will investigate the importance of these organisms in natural hydrocarbon seep environments.

  8. Isolation and characterization of fructophilic lactic acid bacteria from fructose-rich niches.

    PubMed

    Endo, Akihito; Futagawa-Endo, Yuka; Dicks, Leon M T

    2009-12-01

    Fourteen strains of fructophilic lactic acid bacteria were isolated from fructose-rich niches, flowers, and fruits. Phylogenetic analysis and BLAST analysis of 16S rDNA sequences identified six strains as Lactobacillus kunkeei, four as Fructobacillus pseudoficulneus, and one as Fructobacillus fructosus. The remaining three strains grouped within the Lactobacillus buchneri phylogenetic subcluster, but shared low sequence similarities to other known Lactobacillus spp. The fructophilic strains fermented only a few carbohydrates and fermented D-fructose faster than D-glucose. Based on the growth characteristics, the 14 isolates were divided into two groups. Strains in the first group containing L. kunkeei, F. fructosus, and F. pseudoficulneus grew well on D-fructose and on D-glucose with pyruvate or oxygen as external electron acceptors, but poorly on D-glucose without the electron acceptors. Strains in this group were classified as "obligately" fructophilic lactic acid bacteria. The second group contained three unidentified strains of Lactobacillus that grew well on D-fructose and on D-glucose with the electron acceptors. These strains grew on D-glucose without the electron acceptors, but at a delayed rate. Strains in this group were classified as facultatively fructophilic lactic acid bacteria. All fructophilic isolates were heterofermentative lactic acid bacteria, but "obligately" fructophilic lactic acid bacteria mainly produced lactic acid and acetic acid and very little ethanol from D-glucose. Facultatively fructophilic strains produced lactic acid, acetic acid and ethanol, but at a ratio different from that recorded for heterofermentative lactic acid bacteria. These unique characteristics may have been obtained through adaptation to the habitat. PMID:19733991

  9. Stone-isolated carbonatogenic bacteria as inoculants in bioconsolidation treatments for historical limestone.

    PubMed

    Jroundi, Fadwa; Gómez-Suaga, Patricia; Jimenez-Lopez, Concepción; González-Muñoz, Maria Teresa; Fernandez-Vivas, Maria Antonia

    2012-05-15

    Stone consolidation treatments that use bacterial biomineralization are mainly based on two strategies: (1) the inoculation of a bacterial culture with proven carbonatogenic ability and/or (2) the application of a culture medium capable of activating those bacteria able to induce the formation of calcium carbonate, from amongst the bacterial community of the stone. While the second strategy has been demonstrated to be effective and, unlike first strategy, it does not introduce any exogenous microorganism into the stone, problems may arise when the bacterial community of the stone is altered, for instance by the use of biocides in the cleaning process. In this study we isolate bacteria that belong to the natural microbial community of the stone and which have proven biomineralization capabilities, with the aim of preparing an inoculum that may be used in stone consolidation treatments wherein the natural community of those stones is altered. With this aim, outdoor experiments were undertaken to activate and isolate bacteria that display high biomineralization capacity from altered calcarenite stone. Most of the bacteria precipitated calcium carbonate in the form of calcite. The selected bacteria were phylogenetically affiliated with members of Actinobacteria, Gamma-proteobacteria and Firmicutes. Furthermore, the capability of these selected carbonatogenic bacteria to consolidate altered calcarenite stone slabs was studied in in vitro experiments, both in the presence and the absence of Myxococcus xanthus, as a potential reinforcement for the bacterial biomineralization. Herein, Acinetobacter species, belonging to the microbial community of the stone, are proposed as powerful carbonatogenic bacteria that, inoculated under appropriate conditions, may be used as inoculum for calcareous stone conservation/consolidation in restoration interventions where the microbial community of the stone is altered.

  10. Preliminary study on swarming marine bacteria isolated from Pulau Tinggi's sponges

    NASA Astrophysics Data System (ADS)

    Sairi, Fareed; Idris, Hamidah; Zakaria, Nur Syuhana; Usup, Gires; Ahmad, Asmat

    2015-09-01

    Marine sponges were known to produce novel bioactive compounds that have anti-bacterial, anti-viral, anti-cancer and anti-fungal activities. Most of the bioactive compounds were secreted from the bacteria that lives on the sponges. The bacterial communities also produced biofilm, toxin or biosurfactant that protect the sponges from disease or in-coming predator. In this study, twenty nine marine bacteria with swarming motility characteristic was isolated from 2 different sponge samples collected in Pulau Tinggi These isolates were grown and their genome were extracted for molecular identification using the 16S rRNA approach. Sequence comparison using BLASTn and multiple alignments using MEGA4 was performed to produce a phylogenetic tree. The phylogenetic tree revealed that 20 of the isolates were grouped under α-Proteobacteria that comprised of 19 isolates in the Vibrionaceae family and one belongs to Aeromonadaceae family. Furthermore, six isolates from Actinobacteria family and three isolates from Firmicutes were also detected. The swarming characteristic indicates the possible production of biosurfactant.

  11. Bioprospection and selection of bacteria isolated from environments contaminated with petrochemical residues for application in bioremediation.

    PubMed

    Cerqueira, Vanessa S; Hollenbach, Emanuel B; Maboni, Franciele; Camargo, Flávio A O; Peralba, Maria do Carmo R; Bento, Fátima M

    2012-03-01

    The use of microorganisms with hydrocarbon degrading capability and biosurfactant producers have emerged as an alternative for sustainable treatment of environmental passives. In this study 45 bacteria were isolated from samples contaminated with petrochemical residues, from which 21 were obtained from Landfarming soil contaminated with oily sludge, 11 were obtained from petrochemical industry effluents and 13 were originated directly from oily sludge. The metabolization capability of different carbon sources, growth capacity and tolerance, biosurfactant production and enzymes detection were determined. A preliminary selection carried out through the analysis of capability for degrading hydrocarbons showed that 22% of the isolates were able to degrade all carbon sources employed. On the other hand, in 36% of the isolates, the degradation of the oily sludge started within 18-48 h. Those isolates were considered as the most efficient ones. Twenty isolates, identified based on partial sequencing of the 16S rRNA gene, were pre-selected. These isolates showed ability for growing in a medium containing 1% of oily sludge as the sole carbon source, tolerance in a medium containing up to 30% of oily sludge, ability for biosurfactant production, and expression of enzymes involved in degradation of aliphatic and aromatic compounds. Five bacteria, identified as Stenotrophomonas acidaminiphila BB5, Bacillus megaterium BB6, Bacillus cibi, Pseudomonas aeruginosa, and Bacillus cereus BS20 were shown to be promising for use as inoculum in bioremediation processes (bioaugmentation) of areas contaminated with petrochemical residues since they can use oily sludge as the sole carbon source and produce biosurfactants.

  12. Characterization of culturable bacteria isolated from the cold-water coral Lophelia pertusa

    USGS Publications Warehouse

    Galkiewicz, Julia P.; Pratte, Zoe A.; Gray, Michael A.; Kellogg, Christina A.

    2011-01-01

    Microorganisms associated with corals are hypothesized to contribute to the function of the host animal by cycling nutrients, breaking down carbon sources, fixing nitrogen, and producing antibiotics. This is the first study to culture and characterize bacteria from Lophelia pertusa, a cold-water coral found in the deep sea, in an effort to understand the roles that the microorganisms play in the coral microbial community. Two sites in the northern Gulf of Mexico were sampled over 2 years. Bacteria were cultured from coral tissue, skeleton, and mucus, identified by 16S rRNA genes, and subjected to biochemical testing. Most isolates were members of the Gammaproteobacteria, although there was one isolate each from the Betaproteobacteria and Actinobacteria. Phylogenetic results showed that both sampling sites shared closely related isolates (e.g. Pseudoalteromonas spp.), indicating possible temporally and geographically stable bacterial-coral associations. The Kirby-Bauer antibiotic susceptibility test was used to separate bacteria to the strain level, with the results showing that isolates that were phylogenetically tightly grouped had varying responses to antibiotics. These results support the conclusion that phylogenetic placement cannot predict strain-level differences and further highlight the need for culture-based experiments to supplement culture-independent studies.

  13. Characterization of some bacteriocins produced by lactic acid bacteria isolated from fermented foods.

    PubMed

    Grosu-Tudor, Silvia-Simona; Stancu, Mihaela-Marilena; Pelinescu, Diana; Zamfir, Medana

    2014-09-01

    Lactic acid bacteria (LAB) isolated from different sources (dairy products, fruits, fresh and fermented vegetables, fermented cereals) were screened for antimicrobial activity against other bacteria, including potential pathogens and food spoiling bacteria. Six strains have been shown to produce bacteriocins: Lactococcus lactis 19.3, Lactobacillus plantarum 26.1, Enterococcus durans 41.2, isolated from dairy products and Lactobacillus amylolyticus P40 and P50, and Lactobacillus oris P49, isolated from bors. Among the six bacteriocins, there were both heat stable, low molecular mass polypeptides, with a broad inhibitory spectrum, probably belonging to class II bacteriocins, and heat labile, high molecular mass proteins, with a very narrow inhibitory spectrum, most probably belonging to class III bacteriocins. A synergistic effect of some bacteriocins mixtures was observed. We can conclude that fermented foods are still important sources of new functional LAB. Among the six characterized bacteriocins, there might be some novel compounds with interesting features. Moreover, the bacteriocin-producing strains isolated in our study may find applications as protective cultures.

  14. Isolation and characterization of putative endophytic bacteria antagonistic to Phoma tracheiphila and Verticillium albo-atrum.

    PubMed

    Kalai-Grami, Leila; Saidi, Sabrine; Bachkouel, Sarra; Ben Slimene, Imen; Mnari-Hattab, Monia; Hajlaoui, Mohamed Rebah; Limam, Ferid

    2014-09-01

    A collection of 200 bacterial isolates recovered from citrus plants (Citrus limon, Citrus sinensis, and Citrus reticulata), Medicago truncatula and Laurus nobilis, was established. In vitro screening indicated that 28 isolates exhibited an inhibitory activity against the vascular pathogens Phoma tracheiphila and Verticillium albo-atrum. Isolates were screened according to their hydrolytic activities, plant growth-promoting bacteria (PGPB) abilities, as well as for the presence of nonribosomal peptide synthetase (NRPS) genes responsible of the lipopeptide biosynthesis. The results were positive for 16 isolates which exhibited at least two PGPB activities and a single NRPS gene. Genetic diversity of the selected isolates was studied using random amplified polymorphic DNA (RAPD) and repetitive element PCR (REP) tools that showed clustering of strains into three major groups (I, II, and III) (i, ii, and iii), respectively. Clustering was further confirmed by the 16S rDNA sequencing that assigned nine isolates to Bacillus velezensis, four isolates to Bacillus methyltrophicus, one isolate to Bacillus amyloliquefaciens, and two isolates to Bacillus mojavensis. Organ-bacterial genotype interaction as well as positive correlation with NRPS genes are discussed. PMID:25074353

  15. The antimicrobial activity of heterotrophic bacteria isolated from the marine sponge Erylus deficiens (Astrophorida, Geodiidae)

    PubMed Central

    Graça, Ana Patrícia; Viana, Flávia; Bondoso, Joana; Correia, Maria Inês; Gomes, Luis; Humanes, Madalena; Reis, Alberto; Xavier, Joana R.; Gaspar, Helena; Lage, Olga M.

    2015-01-01

    Interest in the study of marine sponges and their associated microbiome has increased both for ecological reasons and for their great biotechnological potential. In this work, heterotrophic bacteria associated with three specimens of the marine sponge Erylus deficiens, were isolated in pure culture, phylogenetically identified and screened for antimicrobial activity. The isolation of bacteria after an enrichment treatment in heterotrophic medium revealed diversity in bacterial composition with only Pseudoalteromonas being shared by two specimens. Of the 83 selected isolates, 58% belong to Proteobacteria, 23% to Actinobacteria and 19% to Firmicutes. Diffusion agar assays for bioactivity screening against four bacterial strains and one yeast, revealed that a high number of the isolated bacteria (68.7%) were active, particularly against Candida albicans and Vibrio anguillarum. Pseudoalteromonas, Microbacterium, and Proteus were the most bioactive genera. After this preliminary screening, the bioactive strains were further evaluated in liquid assays against C. albicans, Bacillus subtilis and Escherichia coli. Filtered culture medium and acetone extracts from three and 5 days-old cultures were assayed. High antifungal activity against C. albicans in both aqueous and acetone extracts as well as absence of activity against B. subtilis were confirmed. Higher levels of activity were obtained with the aqueous extracts when compared to the acetone extracts and differences were also observed between the 3 and 5 day-old extracts. Furthermore, a low number of active strains was observed against E. coli. Potential presence of type-I polyketide synthases (PKS-I) and non-ribosomal peptide synthetases (NRPSs) genes were detected in 17 and 30 isolates, respectively. The high levels of bioactivity and the likely presence of associated genes suggest that Erylus deficiens bacteria are potential sources of novel marine bioactive compounds. PMID:25999928

  16. The antimicrobial activity of heterotrophic bacteria isolated from the marine sponge Erylus deficiens (Astrophorida, Geodiidae).

    PubMed

    Graça, Ana Patrícia; Viana, Flávia; Bondoso, Joana; Correia, Maria Inês; Gomes, Luis; Humanes, Madalena; Reis, Alberto; Xavier, Joana R; Gaspar, Helena; Lage, Olga M

    2015-01-01

    Interest in the study of marine sponges and their associated microbiome has increased both for ecological reasons and for their great biotechnological potential. In this work, heterotrophic bacteria associated with three specimens of the marine sponge Erylus deficiens, were isolated in pure culture, phylogenetically identified and screened for antimicrobial activity. The isolation of bacteria after an enrichment treatment in heterotrophic medium revealed diversity in bacterial composition with only Pseudoalteromonas being shared by two specimens. Of the 83 selected isolates, 58% belong to Proteobacteria, 23% to Actinobacteria and 19% to Firmicutes. Diffusion agar assays for bioactivity screening against four bacterial strains and one yeast, revealed that a high number of the isolated bacteria (68.7%) were active, particularly against Candida albicans and Vibrio anguillarum. Pseudoalteromonas, Microbacterium, and Proteus were the most bioactive genera. After this preliminary screening, the bioactive strains were further evaluated in liquid assays against C. albicans, Bacillus subtilis and Escherichia coli. Filtered culture medium and acetone extracts from three and 5 days-old cultures were assayed. High antifungal activity against C. albicans in both aqueous and acetone extracts as well as absence of activity against B. subtilis were confirmed. Higher levels of activity were obtained with the aqueous extracts when compared to the acetone extracts and differences were also observed between the 3 and 5 day-old extracts. Furthermore, a low number of active strains was observed against E. coli. Potential presence of type-I polyketide synthases (PKS-I) and non-ribosomal peptide synthetases (NRPSs) genes were detected in 17 and 30 isolates, respectively. The high levels of bioactivity and the likely presence of associated genes suggest that Erylus deficiens bacteria are potential sources of novel marine bioactive compounds.

  17. Isolation and partial characterization of phosphate solubilizing bacteria isolated from soil and marine samples.

    PubMed

    Mujahid, Talat Yasmeen; Siddiqui, Khaizran; Ahmed, Rifat; Kazmi, Shahana U; Ahmed, Nuzhat

    2014-09-01

    In the present study the potential of indigenous bacterial isolates from soil rhizosphere and marine environment to promote plant growth was determined. Eight bacterial strains isolated from soil and marine samples were characterized for the phosphate solubilizing activity. Qualitative and quantitative estimation of phosphate solubilization is done. MIC of antibiotic and heavy metals were checked for these strains. Strains show a diverse pattern of antibiotic and heavy metals resistance.

  18. Isolation and Screening of Rhizosphere Bacteria from Grasses in East Kavango Region of Namibia for Plant Growth Promoting Characteristics.

    PubMed

    Haiyambo, D H; Chimwamurombe, P M; Reinhold-Hurek, B

    2015-11-01

    A diverse group of soil bacteria known as plant growth promoting rhizobacteria (PGPR) is able to inhabit the area close to plant roots and exert beneficial effects on plant growth. Beneficial interactions between rhizospheric bacteria and plants provide prospects for isolating culturable PGPR that can be used as bio-fertilizers for sustainable crop production in communities that cannot easily afford chemical fertilizers. This study was conducted with the aim of isolating rhizospheric bacteria from grasses along the Kavango River and screening the bacterial isolates for plant growth promoting characteristics. The bacteria were isolated from rhizospheres of Phragmites australis, Sporobolus sp., Vetiveria nigritana, Pennisetum glaucum and Sorghum bicolor. The isolates were screened for inorganic phosphate solubilization, siderophore production and indole-3-acetic acid (IAA) production. The nitrogen-fixing capability of the bacteria was determined by screening for the presence of the nifH gene. Up to 21 isolates were obtained from P. australis, Sporobolus sp., S. bicolor, P. glaucum and V. nigritana. The genera Bacillus, Enterobacter, Kocuria, Pseudomonas and Stenotrophomonas, identified via 16S rDNA were represented in the 13 PGPR strains isolated. The isolates exhibited more than one plant growth promoting trait and they were profiled as follows: three phosphate solubilizers, four siderophore producers, eight IAA producing isolates and five nitrogen-fixers. These bacteria can be used to develop bio-fertilizer inoculants for improved soil fertility management and sustainable production of local cereals. PMID:26254764

  19. Isolation and Screening of Rhizosphere Bacteria from Grasses in East Kavango Region of Namibia for Plant Growth Promoting Characteristics.

    PubMed

    Haiyambo, D H; Chimwamurombe, P M; Reinhold-Hurek, B

    2015-11-01

    A diverse group of soil bacteria known as plant growth promoting rhizobacteria (PGPR) is able to inhabit the area close to plant roots and exert beneficial effects on plant growth. Beneficial interactions between rhizospheric bacteria and plants provide prospects for isolating culturable PGPR that can be used as bio-fertilizers for sustainable crop production in communities that cannot easily afford chemical fertilizers. This study was conducted with the aim of isolating rhizospheric bacteria from grasses along the Kavango River and screening the bacterial isolates for plant growth promoting characteristics. The bacteria were isolated from rhizospheres of Phragmites australis, Sporobolus sp., Vetiveria nigritana, Pennisetum glaucum and Sorghum bicolor. The isolates were screened for inorganic phosphate solubilization, siderophore production and indole-3-acetic acid (IAA) production. The nitrogen-fixing capability of the bacteria was determined by screening for the presence of the nifH gene. Up to 21 isolates were obtained from P. australis, Sporobolus sp., S. bicolor, P. glaucum and V. nigritana. The genera Bacillus, Enterobacter, Kocuria, Pseudomonas and Stenotrophomonas, identified via 16S rDNA were represented in the 13 PGPR strains isolated. The isolates exhibited more than one plant growth promoting trait and they were profiled as follows: three phosphate solubilizers, four siderophore producers, eight IAA producing isolates and five nitrogen-fixers. These bacteria can be used to develop bio-fertilizer inoculants for improved soil fertility management and sustainable production of local cereals.

  20. [Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibacterial agents (2011)].

    PubMed

    Goto, Hajime; Iwasaki, Mitsuhiro

    2015-04-01

    From October 2011 to September 2012, we collected the specimen from 316 patients with lower respiratory tract infections in 16 institutions in Japan, and investigated the susceptibilities of isolated bacteria to various antibacterial agents and patients' characteristics. All of 357 strains that were isolated from specimen (mainly from sputum) and assumed to be bacteria causing in infection, were examined. The isolated bacteria were: Staphylococcus aureus 51, Streptococcus pneumoniae 73, Haemophilus influenzae 88, Pseudomonas aeruginosa (non-mucoid) 34, P. aeruginosa (mucoid) 9, Klebsiella pneumoniae 21, and Moraxella catarrhalis 33. Of 51 S. aureus strains, those with 2 μg/mL or less of MIC of oxacillin (methicillin-susceptible S. aureus: MSSA) and those with 4 μg/mL or more of MIC of oxacillin (methicillin-resistant S. aureus: MRSA) were 31 (60.8%) and 20 (39.2%) strains, respectively. Against MSSA, imipenem had the most potent antibacterial activity and inhibited the growth of all strains at 0.063 μg/mL or less. Against MRSA, vancomycin showed the potent activity and inhibited the growth of all the strains at 1 μg/mL. Linezolid also showed the great activity and inhibited the growth of all the strains at 2 μg/mL. Carbapenems and penems showed the most potent activities against S. pneumoniae and panipenem inhibited the growth of all the strains at 0.125 μg/mL. Imipenem and faropenem also had a preferable activity and inhibited the growth of all the strains at 0.5 and 1 μg/mL, respectively. In contrast, there were high-resistant strains (MIC: > 128 μg/mL) for erythromycin (53.4%) and clindamycin (3 5.6%). Against H. influenzae, levofloxacin showed the most potent activity and its MIC90 was 0.063 μg/mL or less. Ciprofloxacin showed the most potent activity against P. aeruginosa (mucoid) and inhibited the growth of all the strains at 2 μg/mL or less. Against the non-mucoid type of P. aeruginosa, tobramycin had the most potent activity and its MIC90 was 2

  1. [Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibacterial agents (2010)].

    PubMed

    Goto, Hajime; Iwasaki, Mitsuhiro

    2015-04-01

    From October 2010 to September 2011, we collected the specimen from 361 patients with lower respiratory tract infections in 16 institutions in Japan, and investigated the susceptibilities of isolated bacteria to various antibacterial agents and patients' characteristics. All of 399 strains that were isolated from specimen (mainly from sputum) and assumed to be bacteria causing in infection, were examined. The isolated bacteria were: Staphylococcus aureus 70, Streptococcus pneumoniae 65, Haemophilus influenzae 72, Pseudomonas aeruginosa (non-mucoid) 47, P. aeruginosa (mucoid) 14, Klebsiella pneumoniae 30, and Moraxella catarrhalis 39. Of 70 S. aureus strains, those with 2 μg/mL or less of MIC of oxacillin (methicillin-susceptible S. aureus: MSSA) and those with 4 μg/mL or more of MIC of oxacillin (methicillin-resistant S. aureus: MRSA) were 45 (64.3%) and 25 (35.7%) strains, respectively. Against MSSA, imipenem had the most potent antibacterial activity and inhibited the growth of all strains at 0.063 μg/mL or less. Against MRSA, vancomycin and arbekacin showed the potent activity and inhibited the growth of all the strains at 2 μg/mL. Linezolid also showed the great activity and inhibited the growth of all the strains at 2 μg/mL. Carbapenems and penems showed the most potent activities against S. pneumoniae and panipenem inhibited the growth of all the strains at 0.125 μg/mL. Imipenem and faropenem also had a preferable activity and inhibited the growth of all the strains at 0.5 and 1 μg/mL, respectively. In contrast, there were high-resistant strains (MIC: > 128 μg/mL) for erythromycin (44.6%) and clindamycin (24.6%). Against H. influenzae, levofloxacin showed the most potent activity and its MIC90 was 0.063 μg/mL or less. Meropenem showed the most potent activity against P. aeruginosa (mucoid) and its MIC90 was 0.5 μg/mL. Against the non-mucoid type of P. aeruginosa, tobramycin had the most potent activity and its MIC90 was 2 μg/mL. Against K

  2. Isolation of aluminum-tolerant bacteria capable of nitrogen removal in activated sludge.

    PubMed

    Ji, Bin; Chen, Wei; Zhu, Lei; Yang, Kai

    2016-05-15

    Four strains of bacteria capable of withstanding 20mM concentration of aluminum were isolated from activated sludge in a bioreactor. 16S rRNA identification and morphological characteristics indicated that these strains were Chryseobacterium sp. B1, Brevundimonas diminuta B3, Hydrogenophaga sp. B4, and Bacillus cereus B5. Phylogenetic analysis revealed the position and interrelationships of these bacteria. B. diminuta B3 and Hydrogenophaga sp. B4 could achieve nitrate nitrogen removal of 94.0% and 76.8% within 36h of its initial concentration of 148.8 and 151.7mg/L, respectively. Meanwhile, B3 and B4 could degrade ammonia with little nitrite accumulation. Results of this study provide more information about aluminum-resistant bacteria and laid the foundation for aluminum salt when it is simultaneously used for chemical precipitation. PMID:27038879

  3. Isolation and characterization of histamine-producing bacteria from fermented fish products.

    PubMed

    Moon, Jin Seok; Kim, So-Young; Cho, Kyung-Ju; Yang, Seung-Joon; Yoon, Gun-Mook; Eom, Hyun-Ju; Han, Nam Soo

    2013-12-01

    Histamine is mainly produced by microorganisms that are found in fermented foods, and is frequently involved in food poisoning. Two histamine-producing bacteria were isolated from fermented fish products, anchovy sauce, and sand lance sauce by using a histidine decarboxylating medium. The species were identified as Bacillus licheniformis A7 and B. coagulans SL5. Multiplex PCR analysis showed the presence of the conserved histidine decarboxylase (hdc) gene in the chromosome of these bacteria. B. licheniformis A7 and B. coagulans SL5 produced the maximum amount of histamine (22.3±3.5 and 15.1±1.5 mg/L, respectively). As such, they were determined to be potential histamine-producing bacteria among the tested cultures.

  4. Denitrifying bacteria isolated from terrestrial subsurface sediments exposed to mixed-waste contamination.

    PubMed

    Green, Stefan J; Prakash, Om; Gihring, Thomas M; Akob, Denise M; Jasrotia, Puja; Jardine, Philip M; Watson, David B; Brown, Steven D; Palumbo, Anthony V; Kostka, Joel E

    2010-05-01

    In terrestrial subsurface environments where nitrate is a critical groundwater contaminant, few cultivated representatives are available to verify the metabolism of organisms that catalyze denitrification. In this study, five species of denitrifying bacteria from three phyla were isolated from subsurface sediments exposed to metal radionuclide and nitrate contamination as part of the U.S. Department of Energy's Oak Ridge Integrated Field Research Challenge (OR-IFRC). Isolates belonged to the genera Afipia and Hyphomicrobium (Alphaproteobacteria), Rhodanobacter (Gammaproteobacteria), Intrasporangium (Actinobacteria), and Bacillus (Firmicutes). Isolates from the phylum Proteobacteria were complete denitrifiers, whereas the Gram-positive isolates reduced nitrate to nitrous oxide. rRNA gene analyses coupled with physiological and genomic analyses suggest that bacteria from the genus Rhodanobacter are a diverse population of denitrifiers that are circumneutral to moderately acidophilic, with a high relative abundance in areas of the acidic source zone at the OR-IFRC site. Based on genome analysis, Rhodanobacter species contain two nitrite reductase genes and have not been detected in functional-gene surveys of denitrifying bacteria at the OR-IFRC site. Nitrite and nitrous oxide reductase gene sequences were recovered from the isolates and from the terrestrial subsurface by designing primer sets mined from genomic and metagenomic data and from draft genomes of two of the isolates. We demonstrate that a combination of cultivation and genomic and metagenomic data is essential to the in situ characterization of denitrifiers and that current PCR-based approaches are not suitable for deep coverage of denitrifiers. Our results indicate that the diversity of denitrifiers is significantly underestimated in the terrestrial subsurface. PMID:20305024

  5. Isolation and molecular identification of planctomycete bacteria from postlarvae of the giant tiger prawn, Penaeus monodon.

    PubMed Central

    Fuerst, J A; Gwilliam, H G; Lindsay, M; Lichanska, A; Belcher, C; Vickers, J E; Hugenholtz, P

    1997-01-01

    Bacteria phenotypically resembling members of the phylogenetically distinct planctomycete group of the domain Bacteria were isolated from postlarvae of the giant tiger prawn, Penaeus monodon. A selective medium designed in the light of planctomycete antibiotic resistance characteristics was used for this isolation. Planctomycetes were isolated from both healthy and monodon baculovirus-infected prawn postlarvae. The predominant colony type recovered from postlarvae regardless of viral infection status was nonpigmented. Other, less commonly observed types were pink or orange pigmented. A planctomycete-specific 16S rRNA-directed probe was designed and used to screen the isolates for their identity as planctomycetes prior to molecular phylogenetic characterization. 16S rRNA genes from nine prawn isolates together with two planctomycete reference strains (Planctomyces brasiliensis and Gemmata obscuriglobus) were sequenced and compared with reference sequences from the planctomycetes and other members of the domain Bacteria. Phylogenetic analyses and sequence signatures of the 16S rRNA genes demonstrated that the prawn isolates were members of the planctomycete group. Five representatives of the predominant nonpigmented colony type were members of the Pirellula group within the planctomycetes, as were three pink-pigmented colony type representatives. Homology values and tree topology indicated that representatives of the nonpigmented and pink-pigmented colony types formed two discrete clusters within the Pirellula group, not identical to any known Pirellula species. A sole representative of the orange colony type was a member of the Planctomyces group, virtually identical in 16S rDNA sequence to P. brasiliensis, and exhibited distinctive morphology. PMID:8979353

  6. Denitrifying bacteria isolated from terrestrial subsurface sediments exposed to mixed-waste contamination.

    PubMed

    Green, Stefan J; Prakash, Om; Gihring, Thomas M; Akob, Denise M; Jasrotia, Puja; Jardine, Philip M; Watson, David B; Brown, Steven D; Palumbo, Anthony V; Kostka, Joel E

    2010-05-01

    In terrestrial subsurface environments where nitrate is a critical groundwater contaminant, few cultivated representatives are available to verify the metabolism of organisms that catalyze denitrification. In this study, five species of denitrifying bacteria from three phyla were isolated from subsurface sediments exposed to metal radionuclide and nitrate contamination as part of the U.S. Department of Energy's Oak Ridge Integrated Field Research Challenge (OR-IFRC). Isolates belonged to the genera Afipia and Hyphomicrobium (Alphaproteobacteria), Rhodanobacter (Gammaproteobacteria), Intrasporangium (Actinobacteria), and Bacillus (Firmicutes). Isolates from the phylum Proteobacteria were complete denitrifiers, whereas the Gram-positive isolates reduced nitrate to nitrous oxide. rRNA gene analyses coupled with physiological and genomic analyses suggest that bacteria from the genus Rhodanobacter are a diverse population of denitrifiers that are circumneutral to moderately acidophilic, with a high relative abundance in areas of the acidic source zone at the OR-IFRC site. Based on genome analysis, Rhodanobacter species contain two nitrite reductase genes and have not been detected in functional-gene surveys of denitrifying bacteria at the OR-IFRC site. Nitrite and nitrous oxide reductase gene sequences were recovered from the isolates and from the terrestrial subsurface by designing primer sets mined from genomic and metagenomic data and from draft genomes of two of the isolates. We demonstrate that a combination of cultivation and genomic and metagenomic data is essential to the in situ characterization of denitrifiers and that current PCR-based approaches are not suitable for deep coverage of denitrifiers. Our results indicate that the diversity of denitrifiers is significantly underestimated in the terrestrial subsurface.

  7. Denitrifying Bacteria Isolated from Terrestrial Subsurface Sediments Exposed to Mixed-Waste Contamination▿ †

    PubMed Central

    Green, Stefan J.; Prakash, Om; Gihring, Thomas M.; Akob, Denise M.; Jasrotia, Puja; Jardine, Philip M.; Watson, David B.; Brown, Steven D.; Palumbo, Anthony V.; Kostka, Joel E.

    2010-01-01

    In terrestrial subsurface environments where nitrate is a critical groundwater contaminant, few cultivated representatives are available to verify the metabolism of organisms that catalyze denitrification. In this study, five species of denitrifying bacteria from three phyla were isolated from subsurface sediments exposed to metal radionuclide and nitrate contamination as part of the U.S. Department of Energy's Oak Ridge Integrated Field Research Challenge (OR-IFRC). Isolates belonged to the genera Afipia and Hyphomicrobium (Alphaproteobacteria), Rhodanobacter (Gammaproteobacteria), Intrasporangium (Actinobacteria), and Bacillus (Firmicutes). Isolates from the phylum Proteobacteria were complete denitrifiers, whereas the Gram-positive isolates reduced nitrate to nitrous oxide. rRNA gene analyses coupled with physiological and genomic analyses suggest that bacteria from the genus Rhodanobacter are a diverse population of denitrifiers that are circumneutral to moderately acidophilic, with a high relative abundance in areas of the acidic source zone at the OR-IFRC site. Based on genome analysis, Rhodanobacter species contain two nitrite reductase genes and have not been detected in functional-gene surveys of denitrifying bacteria at the OR-IFRC site. Nitrite and nitrous oxide reductase gene sequences were recovered from the isolates and from the terrestrial subsurface by designing primer sets mined from genomic and metagenomic data and from draft genomes of two of the isolates. We demonstrate that a combination of cultivation and genomic and metagenomic data is essential to the in situ characterization of denitrifiers and that current PCR-based approaches are not suitable for deep coverage of denitrifiers. Our results indicate that the diversity of denitrifiers is significantly underestimated in the terrestrial subsurface. PMID:20305024

  8. Characterization of Quorum Sensing and Quorum Quenching Soil Bacteria Isolated from Malaysian Tropical Montane Forest

    PubMed Central

    Chong, Teik-Min; Koh, Chong-Lek; Sam, Choon-Kook; Choo, Yeun-Mun; Yin, Wai-Fong; Chan, Kok-Gan

    2012-01-01

    We report the production and degradation of quorum sensing N-acyl-homoserine lactones by bacteria isolated from Malaysian montane forest soil. Phylogenetic analysis indicated that these isolates clustered closely to the genera of Arthrobacter, Bacillus and Pseudomonas. Quorum quenching activity was detected in six isolates of these three genera by using a series of bioassays and rapid resolution liquid chromatography analysis. Biosensor screening and high resolution liquid chromatography-mass spectrometry analysis revealed the production of N-dodecanoyl-L-homoserine lactone (C12-HSL) by Pseudomonas frederiksbergensis (isolate BT9). In addition to degradation of a wide range of N-acyl-homoserine lactones, Arthrobacter and Pseudomonas spp. also degraded p-coumaroyl-homoserine lactone. To the best of our knowledge, this is the first documentation of Arthrobacter and Pseudomonas spp. capable of degrading p-coumaroyl-homoserine lactone and the production of C12-HSL by P. frederiksbergensis. PMID:22666062

  9. Phytate-degrading enzyme production by bacteria isolated from Malaysian soil.

    PubMed

    Hussin, Anis Shobirin Meor; Farouk, Abd-ElAziem; Greiner, Ralf; Salleh, Hamzah Mohd; Ismail, Ahmad Faris

    2007-12-01

    Over two hundred bacteria were isolated from the halosphere, rhizosphere and endophyte of Malaysian maize plantation and screened for phytases activity. Thirty isolates with high detectable phytase activity were chosen for media optimization study and species identification. Ten types of bacterial phytase producers have been discovered in this study, which provides opportunity for characterization of new phytase(s) and various commercial and environmental applications. The majority of the bacterial isolates with high detectable phytase activity were of endophyte origin and 1.6% of the total isolates showed phytase activity of more than 1 U/ml. Most of the strains produced extra-cellular phytase and Staphylococcus lentus ASUIA 279 showed the highest phytase activity of 1.913 U/ml. All 30 species used in media optimization study exhibit favorable enzyme production when 1% rice bran was included in the growth media. PMID:27517819

  10. Isolation and identification of bacteria to improve the strength of concrete.

    PubMed

    Krishnapriya, S; Venkatesh Babu, D L; G, Prince Arulraj

    2015-05-01

    The objective of this research work is to isolate and identify calcite precipitating bacteria and to check the suitability of these bacteria for use in concrete to improve its strength. Bacteria to be incorporated in concrete should be alkali resistant to endure the high pH of concrete and endospore forming to withstand the mechanical stresses induced in concrete during mixing. They must exhibit high urease activity to precipitate calcium carbonate in the form of calcite. Bacterial strains were isolated from alkaline soil samples of a cement factory and were tested for urease activity, potential to form endospores and precipitation of calcium carbonate. Based on these results, three isolates were selected and identified by 16S rRNA gene sequencing. They were identified as Bacillus megaterium BSKAU, Bacillus licheniformis BSKNAU and Bacillus flexus BSKNAU. The results were compared with B. megaterium MTCC 1684 obtained from Microbial Type Culture Collection and Gene Bank, Chandigarh, India. Experimental work was carried out to assess the influence of bacteria on the compressive strength and tests revealed that bacterial concrete specimens showed enhancement in compressive strength. The efficiency of bacteria toward crack healing was also tested. Substantial increase in strength and complete healing of cracks was observed in concrete specimens cast with B. megaterium BSKAU, B. licheniformis BSKNAU and B. megaterium MTCC 1684. This indicates the suitability of these bacterial strains for use in concrete. The enhancement of strength and healing of cracks can be attributed to the filling of cracks in concrete by calcite which was visualized by scanning electron microscope. PMID:25946328

  11. Isolation of Butanol- and Isobutanol-Tolerant Bacteria and Physiological Characterization of Their Butanol Tolerance

    PubMed Central

    Kanno, Manabu; Katayama, Taiki; Tamaki, Hideyuki; Mitani, Yasuo; Meng, Xian-Ying; Hori, Tomoyuki; Narihiro, Takashi; Morita, Naoki; Hoshino, Tamotsu; Yumoto, Isao; Kimura, Nobutada; Hanada, Satoshi

    2013-01-01

    Despite their importance as a biofuel production platform, only a very limited number of butanol-tolerant bacteria have been identified thus far. Here, we extensively explored butanol- and isobutanol-tolerant bacteria from various environmental samples. A total of 16 aerobic and anaerobic bacteria that could tolerate greater than 2.0% (vol/vol) butanol and isobutanol were isolated. A 16S rRNA gene sequencing analysis revealed that the isolates were phylogenetically distributed over at least nine genera: Bacillus, Lysinibacillus, Rummeliibacillus, Brevibacillus, Coprothermobacter, Caloribacterium, Enterococcus, Hydrogenoanaerobacterium, and Cellulosimicrobium, within the phyla Firmicutes and Actinobacteria. Ten of the isolates were phylogenetically distinct from previously identified butanol-tolerant bacteria. Two relatively highly butanol-tolerant strains CM4A (aerobe) and GK12 (obligate anaerobe) were characterized further. Both strains changed their membrane fatty acid composition in response to butanol exposure, i.e., CM4A and GK12 exhibited increased saturated and cyclopropane fatty acids (CFAs) and long-chain fatty acids, respectively, which may serve to maintain membrane fluidity. The gene (cfa) encoding CFA synthase was cloned from strain CM4A and expressed in Escherichia coli. The recombinant E. coli showed relatively higher butanol and isobutanol tolerance than E. coli without the cfa gene, suggesting that cfa can confer solvent tolerance. The exposure of strain GK12 to butanol by consecutive passages even enhanced the growth rate, indicating that yet-unknown mechanisms may also contribute to solvent tolerance. Taken together, the results demonstrate that a wide variety of butanol- and isobutanol-tolerant bacteria that can grow in 2.0% butanol exist in the environment and have various strategies to maintain structural integrity against detrimental solvents. PMID:24014527

  12. Isolation and identification of bacteria to improve the strength of concrete.

    PubMed

    Krishnapriya, S; Venkatesh Babu, D L; G, Prince Arulraj

    2015-05-01

    The objective of this research work is to isolate and identify calcite precipitating bacteria and to check the suitability of these bacteria for use in concrete to improve its strength. Bacteria to be incorporated in concrete should be alkali resistant to endure the high pH of concrete and endospore forming to withstand the mechanical stresses induced in concrete during mixing. They must exhibit high urease activity to precipitate calcium carbonate in the form of calcite. Bacterial strains were isolated from alkaline soil samples of a cement factory and were tested for urease activity, potential to form endospores and precipitation of calcium carbonate. Based on these results, three isolates were selected and identified by 16S rRNA gene sequencing. They were identified as Bacillus megaterium BSKAU, Bacillus licheniformis BSKNAU and Bacillus flexus BSKNAU. The results were compared with B. megaterium MTCC 1684 obtained from Microbial Type Culture Collection and Gene Bank, Chandigarh, India. Experimental work was carried out to assess the influence of bacteria on the compressive strength and tests revealed that bacterial concrete specimens showed enhancement in compressive strength. The efficiency of bacteria toward crack healing was also tested. Substantial increase in strength and complete healing of cracks was observed in concrete specimens cast with B. megaterium BSKAU, B. licheniformis BSKNAU and B. megaterium MTCC 1684. This indicates the suitability of these bacterial strains for use in concrete. The enhancement of strength and healing of cracks can be attributed to the filling of cracks in concrete by calcite which was visualized by scanning electron microscope.

  13. Isolation and characterization of entomopathogenic bacteria from soil samples from the western region of Cuba.

    PubMed

    González, Aileen; Rodríguez, Graciela; Bruzón, Rosa Y; Díaz, Manuel; Companionis, Ariamys; Menéndez, Zulema; Gato, René

    2013-06-01

    The use of insect pathogens is a viable alternative for insect control because of their relative specificity and lower environmental impact. The search for wild strains against dipterans could have an impact on mosquito control programs. We have made an extensive screening of soil in western Cuba to find bacteria with larvicidal activity against mosquitoes. A total of 150 soil samples were collected and isolates were identifying using the API 50 CHB gallery. Phenotypic characteristics were analyzed by hierarchical ascending classification. Quantitative bioassays were conducted under laboratory conditions following the World Health Organization protocol in order to ascertain the toxicity and efficacy of isolates. The protein profiles of the crystal components were determined by SDS-PAGE. Eight hundred and eighty-one bacterial isolates were obtained, and 13 isolates with entomopathogenic activity were isolated from nine samples. Nine isolates displayed higher entomopathogenic activity against both Cx. quinquefasciatus and Ae. aegypti compared with the reference strain 266/2. All toxic isolates showed higher biological potency than the 266/2 strain. These isolates with high entomopathogenic activity displayed a protein pattern similar to the B. thuringiensis var. israelensis IPS-82 and 266/2 strains. These results are a valuable tool for the control of Diptera of medical importance. PMID:23701606

  14. Isolation and characterization of diesel degrading bacteria, Sphingomonas sp. and Acinetobacter junii from petroleum contaminated soil

    NASA Astrophysics Data System (ADS)

    Zhang, Qiuzhuo; Wang, Duanchao; Li, Mengmeng; Xiang, Wei-Ning; Achal, Varenyam

    2014-03-01

    Two indigenous bacteria of petroleum contaminated soil were characterized to utilize diesel fuel as the sole carbon and energy sources in this work. 16S rRNA gene sequence analysis identified these bacteria as Sphingomonas sp. and Acinetobacter junii. The ability to degrade diesel fuel has been demonstrated for the first time by these isolates. The results of IR analyses showed that Sphingomonas sp. VA1 and A. junii VA2 degraded up to 82.6% and 75.8% of applied diesel over 15 days, respectively. In addition, Sphingomonas sp. VA1 possessed the higher cellular hydrophobicities of 94% for diesel compared to 81% by A. junii VA2. The isolates Sphingomonas sp. VA1 and A. junii VA2 exhibited 24% and 18%, respectively emulsification activity. This study reports two new diesel degrading bacterial species, which can be effectively used for bioremediation of petroleum contaminated sites.

  15. [Improvement of the method of isolation of hydrogen-forming bacteria of Clostridium genus].

    PubMed

    Pritula, I R; Tashirev, A B

    2012-01-01

    The method of isolation and quantitative account of pure cultures of obligate anaerobic hydrogen-forming clostridia is improved. A strain of hydrogen-forming bacteria Clostridium sp. BY-11 has been isolated from the association of sporulating bacteria. Quantitative indices of hydrogen synthesis and starch fermentation have been determined when growing the strain in the liquid medium. Concentration of H2 in the gas phase was 49%, microorganisms synthesized 128 1 of H2 from 1 kg of starch, the mass of starch decreased 7 times for 6 days. The mentioned indices for hydrogen synthesis and starch fermentation and for other organic model substrates in the future are the basis for creating the industrial biotechnology for production of hydrogen as the energy carrier under disposal of ecologically dangerous solid food waste. PMID:23293828

  16. [Improvement of the method of isolation of hydrogen-forming bacteria of Clostridium genus].

    PubMed

    Pritula, I R; Tashirev, A B

    2012-01-01

    The method of isolation and quantitative account of pure cultures of obligate anaerobic hydrogen-forming clostridia is improved. A strain of hydrogen-forming bacteria Clostridium sp. BY-11 has been isolated from the association of sporulating bacteria. Quantitative indices of hydrogen synthesis and starch fermentation have been determined when growing the strain in the liquid medium. Concentration of H2 in the gas phase was 49%, microorganisms synthesized 128 1 of H2 from 1 kg of starch, the mass of starch decreased 7 times for 6 days. The mentioned indices for hydrogen synthesis and starch fermentation and for other organic model substrates in the future are the basis for creating the industrial biotechnology for production of hydrogen as the energy carrier under disposal of ecologically dangerous solid food waste.

  17. Isolation, identification and characterization of fluoride resistant bacteria: possible role in bioremediation.

    PubMed

    Chouhan, S; Tuteja, U; Flora, S J S

    2012-01-01

    Microorganisms found in industrial effluents and near the sites of the contamination can be used to indicate pollution and detoxify the contaminated water resources. Emergence of xenobiotic resistant bacteria among them might be potential application in bioremediation. The objective of this study was to isolate and characterize fluoride resistant bacteria from soil and water samples of different regions of India. Five isolates were recovered from different samples which were found to be fluoride resistant. Two of them effectively reduced the fluoride from their media. Through the current study it can be predicted that fluoride pollution results in selective pressure that leads to the development of fluoride resistant among bacterial populations, probably through the mechanism which involved high affinity anion binding compounds called ionophores. Resistant microbes may play a bioremediative role by transforming and concentrating these anions so that they are less available and less dangerous. PMID:22567885

  18. Inhibition of food-borne bacterial pathogens by bacteriocins from lactic acid bacteria isolated from meat.

    PubMed Central

    Lewus, C B; Kaiser, A; Montville, T J

    1991-01-01

    Ten strains of bacteriocin-producing lactic acid bacteria were isolated from retail cuts of meat. These 10 strains along with 11 other bacteriocin-producing lactic acid bacteria were tested for inhibitory activity against psychotrophic pathogens, including four strains of Listeria monocytogenes, two strains of Aeromonas hydrophila, and two strains of Staphylococcus aureus. Inhibition due to acid, hydrogen peroxide, and lytic bacteriophage were excluded. The proteinaceous nature of the inhibitory substance was confirmed by demonstration of its sensitivity to proteolytic enzymes. Eight of the meat isolates had inhibitory activity against all four L. monocytogenes strains. Bacteriocin activity against L. monocytogenes was found in all of the strains obtained from other sources. Activity against A. hydrophila and S. aureus was also common. Images PMID:1908209

  19. Biochemical characteristics and virulence of environmental group F bacteria isolated in the United States.

    PubMed Central

    Seidler, R J; Allen, D A; Colwell, R R; Joseph, S W; Daily, O P

    1980-01-01

    Bacteria phenotypically resembling Aeromonas hydrophila, but requiring NaCl for growth, have been isolated form the New York Bight. The bacteria proved to be identical to group F organisms isolated from cases of human diarrhea in Indonesia and Bangladesh. Anaerogenic strains initiated responses in Y-1 tissue culture and rabbit ileal loop, consistent with those associated with cytotoxin- and enterotoxin-producing Aeromonas spp. strains. Separation on the basis of production of gas from glucose by group F strains was correlated with differences in mean guanine-plus-cytosine deoxyribonucleic acid base composition and in deoxyribonucleic acid relative reassociation. Both aerogenic and anaerogenic strains reassociated to a significantly greater extent with Vibrio spp. than with Aeromonas spp. and indeed should be considered a new species of the genus Vibrio. PMID:7425623

  20. Isolation and Characterization of Bacteria Capable of Tolerating the Extreme Conditions of Clean Room Environments▿

    PubMed Central

    La Duc, Myron T.; Dekas, Anne; Osman, Shariff; Moissl, Christine; Newcombe, David; Venkateswaran, Kasthuri

    2007-01-01

    In assessing the bacterial populations present in spacecraft assembly, spacecraft test, and launch preparation facilities, extremophilic bacteria (requiring severe conditions for growth) and extremotolerant bacteria (tolerant to extreme conditions) were isolated. Several cultivation approaches were employed to select for and identify bacteria that not only survive the nutrient-limiting conditions of clean room environments but can also withstand even more inhospitable environmental stresses. Due to their proximity to spacefaring objects, these bacteria pose a considerable risk for forward contamination of extraterrestrial sites. Samples collected from four geographically distinct National Aeronautics and Space Administration clean rooms were challenged with UV-C irradiation, 5% hydrogen peroxide, heat shock, pH extremes (pH 3.0 and 11.0), temperature extremes (4°C to 65°C), and hypersalinity (25% NaCl) prior to and/or during cultivation as a means of selecting for extremotolerant bacteria. Culture-independent approaches were employed to measure viable microbial (ATP-based) and total bacterial (quantitative PCR-based) burdens. Intracellular ATP concentrations suggested a viable microbial presence ranging from below detection limits to 106 cells/m2. However, only 0.1 to 55% of these viable cells were able to grow on defined culture medium. Isolated members of the Bacillaceae family were more physiologically diverse than those reported in previous studies, including thermophiles (Geobacillus), obligate anaerobes (Paenibacillus), and halotolerant, alkalophilic species (Oceanobacillus and Exiguobacterium). Non-spore-forming microbes (α- and β-proteobacteria and actinobacteria) exhibiting tolerance to the selected stresses were also encountered. The multiassay cultivation approach employed herein enhances the current understanding of the physiological diversity of bacteria housed in these clean rooms and leads us to ponder the origin and means of translocation of

  1. Isolation and Genetic Analysis of Multidrug Resistant Bacteria from Diabetic Foot Ulcers.

    PubMed

    Shahi, Shailesh K; Kumar, Ashok

    2015-01-01

    Severe diabetic foot ulcers (DFUs) patients visiting Sir Sunderlal Hospital, Banaras Hindu University, Varanasi, were selected for this study. Bacteria were isolated from swab and deep tissue of 42 patients, for examining their prevalence and antibiotic sensitivity. DFUs of majority of the patients were found infected with Enterococcus spp. (47.61%), Escherichia coli (35.71%), Staphylococcus spp. (33.33%), Alcaligenes spp. (30.95%), Pseudomonas spp. (30.95%), and Stenotrophomonas spp. (30.95%). Antibiotic susceptibility assay of 142 bacteria with 16 antibiotics belonging to eight classes showed the presence of 38 (26.76%) isolates with multidrug resistance (MDR) phenotypes. MDR character appeared to be governed by integrons as class 1 integrons were detected in 26 (68.42%) isolates. Altogether six different arrays of genes (aadA1, aadB, aadAV, dhfrV, dhfrXII, and dhfrXVII) were found within class 1 integron. Gene cassette dhfrAXVII-aadAV (1.6 kb) was present in 12 (3 Gram positive and 9 Gram negative) isolates and was conserved across all the isolates as evident from RFLP analysis. In addition to the presence of class 1 integron, six β-lactamase resistance encoding genes namely bla TEM, bla SHV, bla OXA, bla CTX-M-gp1, bla CTX-M-gp2, and bla CTX-M-gp9 and two methicillin resistance genes namely mecA and femA and vancomycin resistance encoding genes (vanA and vanB) were identified in different isolates. Majority of the MDR isolates were positive for bla TEM (89.47%), bla OXA (52.63%), and bla CTX-M-gp1 (34.21%). To our knowledge, this is the first report of molecular characterization of antibiotic resistance in bacteria isolated from DFUs from North India. In conclusion, findings of this study suggest that class-1 integrons and β-lactamase genes contributed to the MDR in above bacteria. PMID:26779134

  2. Isolation and Genetic Analysis of Multidrug Resistant Bacteria from Diabetic Foot Ulcers

    PubMed Central

    Shahi, Shailesh K.; Kumar, Ashok

    2016-01-01

    Severe diabetic foot ulcers (DFUs) patients visiting Sir Sunderlal Hospital, Banaras Hindu University, Varanasi, were selected for this study. Bacteria were isolated from swab and deep tissue of 42 patients, for examining their prevalence and antibiotic sensitivity. DFUs of majority of the patients were found infected with Enterococcus spp. (47.61%), Escherichia coli (35.71%), Staphylococcus spp. (33.33%), Alcaligenes spp. (30.95%), Pseudomonas spp. (30.95%), and Stenotrophomonas spp. (30.95%). Antibiotic susceptibility assay of 142 bacteria with 16 antibiotics belonging to eight classes showed the presence of 38 (26.76%) isolates with multidrug resistance (MDR) phenotypes. MDR character appeared to be governed by integrons as class 1 integrons were detected in 26 (68.42%) isolates. Altogether six different arrays of genes (aadA1, aadB, aadAV, dhfrV, dhfrXII, and dhfrXVII) were found within class 1 integron. Gene cassette dhfrAXVII-aadAV (1.6 kb) was present in 12 (3 Gram positive and 9 Gram negative) isolates and was conserved across all the isolates as evident from RFLP analysis. In addition to the presence of class 1 integron, six β-lactamase resistance encoding genes namely blaTEM, blaSHV, blaOXA, blaCTX−M−gp1, blaCTX−M−gp2, and blaCTX−M−gp9 and two methicillin resistance genes namely mecA and femA and vancomycin resistance encoding genes (vanA and vanB) were identified in different isolates. Majority of the MDR isolates were positive for blaTEM (89.47%), blaOXA (52.63%), and blaCTX−M−gp1 (34.21%). To our knowledge, this is the first report of molecular characterization of antibiotic resistance in bacteria isolated from DFUs from North India. In conclusion, findings of this study suggest that class-1 integrons and β-lactamase genes contributed to the MDR in above bacteria. PMID:26779134

  3. Cultivation of Denitrifying Bacteria: Optimization of Isolation Conditions and Diversity Study†

    PubMed Central

    Heylen, Kim; Vanparys, Bram; Wittebolle, Lieven; Verstraete, Willy; Boon, Nico; De Vos, Paul

    2006-01-01

    An evolutionary algorithm was applied to study the complex interactions between medium parameters and their effects on the isolation of denitrifying bacteria, both in number and in diversity. Growth media with a pH of 7 and a nitrogen concentration of 3 mM, supplemented with 1 ml of vitamin solution but not with sodium chloride or riboflavin, were the most successful for the isolation of denitrifiers from activated sludge. The use of ethanol or succinate as a carbon source and a molar C/N ratio of 2.5, 20, or 25 were also favorable. After testing of 60 different medium parameter combinations and comparison with each other as well as with the standard medium Trypticase soy agar supplemented with nitrate, three growth media were highly suitable for the cultivation of denitrifying bacteria. All evaluated isolation conditions were used to study the cultivable denitrifier diversity of activated sludge from a municipal wastewater treatment plant. One hundred ninety-nine denitrifiers were isolated, the majority of which belonged to the Betaproteobacteria (50.4%) and the Alphaproteobacteria (36.8%). Representatives of Gammaproteobacteria (5.6%), Epsilonproteobacteria (2%), and Firmicutes (4%) and one isolate of the Bacteroidetes were also found. This study revealed a much more diverse denitrifying community than that previously described in cultivation-dependent research on activated sludge. PMID:16597968

  4. Antibiotic resistance patterns of gram-negative bacteria isolated from environmental sources.

    PubMed Central

    Kelch, W J; Lee, J S

    1978-01-01

    A total of 2,445 gram-negative bacteria belonging to fecal coliform, Pseudomonas, Moraxella, Acinetobacter, and Flavobacterium-Cytophaga groups were isolated from the rivers and bay of Tillamook, Oregon, and their resistances to chloramphenicol (25 microgram/ml), streptomycin (10 microgram/ml), ampicillin (10 microgram/ml), tetracycline (25 microgram/ml), chlortetracycline (25 microgram/ml), oxytetracycline (25 microgram/ml), neomycin (50 microgram/ml), nitrofurazone (12.5 microgram/ml), nalidixic acid (25 microgram/ml), kanamycin (25 microgram/ml), and penicillin G (10 IU/ml) were determined. Among fecal coliforms the bay isolates showed greater resistance to antibiotics than those from tributaries or surface runoff. No such well-defined difference was found among other bacterial groups. The antibiotic resistance patterns of gram-negative bacteria from different sources correlated well, perhaps indicating their common origin. The antibiotic resistance patterns of gram-negative bacteria of different general also correlated well, perhaps indicating that bacteria which share a common environment also share a common mode for developing antibiotic resistance. PMID:727777

  5. Isolation of Indole Utilizing Bacteria Arthrobacter sp. and Alcaligenes sp. From Livestock Waste.

    PubMed

    Kim, Minsu; Lee, Jin-Hyung; Kim, Eonmi; Choi, Hyukjae; Kim, Younghoon; Lee, Jintae

    2016-06-01

    Indole is an interspecies and interkingdom signaling molecule widespread in different environmental compartment. Although multifaceted roles of indole in different biological systems have been established, little information is available on the microbial utilization of indole in the context of combating odor emissions from different types of waste. The present study was aimed at identifying novel bacteria capable of utilizing indole as the sole carbon and energy source. From the selective enrichment of swine waste and cattle feces, we identified Gram-positive and Gram-negative bacteria belonging to the genera Arthrobacter and Alcaligenes. Bacteria belonging to the genus Alcaligenes showed higher rates of indole utilization than Arthrobacter. Indole at 1.0 mM for growth was completely utilized by Alcaligenes sp. in 16 h. Both strains produced two intermediates, anthranilic acid and isatin, during aerobic indole metabolism. These isolates were also able to grow on several indole derivatives. Interestingly, an adaptive response in terms of a decrease in cell size was observed in both strains in the presence of indole. The present study will help to explain the degradation of indole by different bacteria and also the pathways through which it is catabolized. Furthermore, these novel bacterial isolates could be potentially useful for the in situ attenuation of odorant indole and its derivatives emitted from different types of livestock waste. PMID:27570307

  6. Novel Simplified and Rapid Method for Screening and Isolation of Polyunsaturated Fatty Acids Producing Marine Bacteria

    PubMed Central

    Tilay, Ashwini; Annapure, Uday

    2012-01-01

    Bacterial production of polyunsaturated fatty acids (PUFAs) is a potential biotechnological approach for production of valuable nutraceuticals. Reliable method for screening of number of strains within short period of time is great need. Here, we report a novel simplified method for screening and isolation of PUFA-producing bacteria by direct visualization using the H2O2-plate assay. The oxidative stability of PUFAs in growing bacteria towards added H2O2 is a distinguishing characteristic between the PUFAs producers (no zone of inhibition) and non-PUFAs producers (zone of inhibition) by direct visualization. The confirmation of assay results was performed by injecting fatty acid methyl esters (FAMEs) produced by selected marine bacteria to Gas Chromatography-Mass Spectrometry (GCMS). To date, this assay is the most effective, inexpensive, and specific method for bacteria producing PUFAs and shows drastically reduction in the number of samples thus saves the time, effort, and cost of screening and isolating strains of bacterial PUFAs producers. PMID:22934188

  7. Isolation, culture characteristics, and identification of anaerobic bacteria from the chicken cecum.

    PubMed

    Salanitro, J P; Fairchilds, I G; Zgornicki, Y D

    1974-04-01

    Studies on the anaerobic cecal microflora of the 5-week-old chicken were made to determine a suitable roll-tube medium for enumeration and isolation of the bacterial population, to determine effects of medium components on recovery of total anaerobes, and to identify the predominant bacterial groups. The total number of microorganisms in cecal contents determined by direct microscope cell counts varied (among six samples) from 3.83 x 10(10) to 7.64 x 10(10) per g. Comparison of different nonselective media indicated that 60% of the direct microscope count could be recovered with a rumen fluid medium (M98-5) and 45% with medium 10. Deletion of rumen fluid from M98-5 reduced the total anaerobic count by half. Colony counts were lower if chicken cecal extract was substituted for rumen fluid in M98-5. Supplementing medium 10 with liver, chicken fecal, or cecal extracts improved recovery of anaerobes slightly. Prereduced blood agar media were inferior to M98-5. At least 11 groups of bacteria were isolated from high dilutions (10(-9)) of cecal material. Data on morphology and physiological and fermentation characteristics of 90% of the 298 isolated strains indicated that these bacteria represented species of anaerobic gram-negative cocci, facultatively anaerobic cocci and streptococci, Peptostreptococcus, Propionibacterium, Eubacterium, Bacteroides, and Clostridium. The growth of many of these strains was enhanced by rumen fluid, yeast extract, and cecal extract additions to basal media. These studies indicate that some of the more numerous anaerobic bacteria present in chicken cecal digesta can be isolated and cultured when media and methods that have been developed for ruminal bacteria are employed.

  8. Improved oil recovery using bacteria isolated from North Sea petroleum reservoirs

    SciTech Connect

    Davey, R.A.; Lappin-Scott, H.

    1995-12-31

    During secondary oil recovery, water is injected into the formation to sweep out the residual oil. The injected water, however, follows the path of least resistance through the high-permeability zones, leaving oil in the low-permeability zones. Selective plugging of these their zones would divert the waterflood to the residual oil and thus increase the life of the well. Bacteria have been suggested as an alternative plugging agent to the current method of polymer injection. Starved bacteria can penetrate deeply into rock formations where they attach to the rock surfaces, and given the right nutrients can grow and produce exo-polymer, reducing the permeability of these zones. The application of microbial enhanced oil recovery has only been applied to shallow, cool, onshore fields to date. This study has focused on the ability of bacteria to enhance oil recovery offshore in the North Sea, where the environment can be considered extreme. A screen of produced water from oil reservoirs (and other extreme subterranean environments) was undertaken, and two bacteria were chosen for further work. These two isolates were able to grow and survive in the presence of saline formation waters at a range of temperatures above 50{degrees}C as facultative anaerobes. When a solution of isolates was passed through sandpacks and nutrients were added, significant reductions in permeabilities were achieved. This was confirmed in Clashach sandstone at 255 bar, when a reduction of 88% in permeability was obtained. Both isolates can survive nutrient starvation, which may improve penetration through the reservoir. Thus, the isolates show potential for field trials in the North Sea as plugging agents.

  9. Biofilm-forming activity of bacteria isolated from toilet bowl biofilms and the bactericidal activity of disinfectants against the isolates.

    PubMed

    Mori, Miho; Gomi, Mitsuhiro; Matsumune, Norihiko; Niizeki, Kazuma; Sakagami, Yoshikazu

    2013-01-01

    To evaluate the sanitary conditions of toilets, the bacterial counts of the toilet bowl biofilms in 5 Kansai area and 11 Kansai and Kanto area homes in Japan were measured in winter and summer seasons, respectively. Isolates (128 strains) were identified by analyzing 16S ribosomal RNA sequences. The number of colonies and bacterial species from biofilms sampled in winter tended to be higher and lower, respectively, than those in summer. Moreover, the composition of bacterial communities in summer and winter samples differed considerably. In summer samples, biofilms in Kansai and Kanto areas were dominated by Blastomonas sp. and Mycobacterium sp., respectively. Methylobacterium sp. was detected in all toilet bowl biofilms except for one sample. Methylobacterium sp. constituted the major presence in biofilms along with Brevundimonas sp., Sphingomonas sp., and/or Pseudomonas sp. The composition ratio of the sum of their genera was 88.0 from 42.9% of the total bacterial flora. The biofilm formation abilities of 128 isolates were investigated, and results suggested that Methylobacterium sp. and Sphingomonas sp. were involved in biofilm formation in toilet bowls. The biofilm formation of a mixed bacteria system that included bacteria with the highest biofilm-forming ability in a winter sample was greater than mixture without such bacteria. This result suggests that isolates possessing a high biofilm-forming activity are involved in the biofilm formation in the actual toilet bowl. A bactericidal test against 25 strains indicated that the bactericidal activities of didecyldimethylammonium chloride (DDAC) tended to be higher than those of polyhexamethylene biguanide (PHMB) and N-benzyl-N,N-dimethyldodecylammonium chloride (ADBAC). In particular, DDAC showed high bactericidal activity against approximately 90% of tested strains under the 5 h treatment.

  10. Isolation of butyrate-utilizing bacteria from thermophilic and mesophilic methane-producing ecosystems

    SciTech Connect

    Henson, J.M.

    1983-01-01

    The ability of various ecosystems to convert butyrate to methane was studied in order to isolate the bacteria responsible for the conversion. When thermophilic digester sludge was enriched with butyrate, methane was produced without a lag period. Marine sediments enriched with butyrate required a 2-week incubation period before methanogenesis began. A thermophilic digester was studied in more detail and found by most-probable-number enumeration to have ca. 5 x 10/sup 6/ butyrate-utilizing bactera/ml of sludge. A thermophilic butyrate-utilizing bacterium was isolated in coculture with Methanobacterium thermoautotrophicum and a Methanosarcina sp. This bacterium was a gram-negative, slightly curved rod that occurred singly, was nonmotile, and did not appear to produce spores. The thermophilic digester was infused with butyrate at the rate of 10 ..mu..moles/ml of sludge per day. Biogas production increased by 150%, with the percentage of methane increasing from 58% to 68%. Acetate, propionate, and butyrate did not accumulate. Butyrate-utilizing enrichments from mesophilic ecosystems were used in obtaining cocultures of butyrate-utilizing bacteria. These cocultures served as inocula for attempts to isolate pure cultures of butyrate-utilizing bacteria by use of hydrogenase-containing membrane fragments of Escherichia coli. After a 3-week incubation period, colonies appeared only in inoculated tubes that contained membrane fragments and butyrate.

  11. Morphological and genetic characterization of endophytic bacteria isolated from roots of different maize genotypes.

    PubMed

    Ikeda, Angela Cristina; Bassani, Luciana Lange; Adamoski, Douglas; Stringari, Danyelle; Cordeiro, Vanessa Kava; Glienke, Chirlei; Steffens, Maria Berenice Reynaud; Hungria, Mariangela; Galli-Terasawa, Lygia Vitoria

    2013-01-01

    Maize is one of the most important crops worldwide, and in Brazil, the state of Paraná stands as its largest producer. The crop demands high inputs of N fertilizers, therefore all strategies aiming to optimize the grain production with lower inputs are very relevant. Endophytic bacteria have a high potential to increment maize grain yield by means of input via biological nitrogen fixation and/or plant growth promotion, in this last case increasing the absorption of water and nutrients by the plants. In this study, we established a collection of 217 endophytic bacteria, isolated from roots of four lineages and three hybrid genotypes of maize, and isolated in four different N-free culture media. Biochemical-comprising growth in different carbon sources, intrinsic tolerance to antibiotics, and biochemical tests for catalase, nitrate reductase, urease, and growth in N-free media in vitro-and genetic characterization by BOX-PCR revealed great variability among the isolates. Both commercial hybrids and homozygous lineages were broadly colonized by endophytes, and sequencing of the 16S rRNA gene revealed the presence of bacteria belonging to the genera Pantoea, Bacillus, Burkholderia, and Klebsiella. Qualitative differences in endophytic colonization were detected between lineages and hybrid genotypes.

  12. Functional Characterization of Bacteria Isolated from Ancient Arctic Soil Exposes Diverse Resistance Mechanisms to Modern Antibiotics

    PubMed Central

    Perron, Gabriel G.; Whyte, Lyle; Turnbaugh, Peter J.; Goordial, Jacqueline; Hanage, William P.; Dantas, Gautam; Desai, Michael M.

    2015-01-01

    Using functional metagenomics to study the resistomes of bacterial communities isolated from different layers of the Canadian high Arctic permafrost, we show that microbial communities harbored diverse resistance mechanisms at least 5,000 years ago. Among bacteria sampled from the ancient layers of a permafrost core, we isolated eight genes conferring clinical levels of resistance against aminoglycoside, β-lactam and tetracycline antibiotics that are naturally produced by microorganisms. Among these resistance genes, four also conferred resistance against amikacin, a modern semi-synthetic antibiotic that does not naturally occur in microorganisms. In bacteria sampled from the overlaying active layer, we isolated ten different genes conferring resistance to all six antibiotics tested in this study, including aminoglycoside, β-lactam and tetracycline variants that are naturally produced by microorganisms as well as semi-synthetic variants produced in the laboratory. On average, we found that resistance genes found in permafrost bacteria conferred lower levels of resistance against clinically relevant antibiotics than resistance genes sampled from the active layer. Our results demonstrate that antibiotic resistance genes were functionally diverse prior to the anthropogenic use of antibiotics, contributing to the evolution of natural reservoirs of resistance genes. PMID:25807523

  13. Isolation and Identification of Cellulolytic Bacteria from the Gut of Holotrichia parallela Larvae (Coleoptera: Scarabaeidae)

    PubMed Central

    Huang, Shengwei; Sheng, Ping; Zhang, Hongyu

    2012-01-01

    In this study, 207 strains of aerobic and facultatively anaerobic cellulolytic bacteria were isolated from the gut of Holotrichia parallela larvae. These bacterial isolates were assigned to 21 genotypes by amplified ribosomal DNA restriction analysis (ARDRA). A partial 16S rDNA sequence analysis and standard biochemical and physiological tests were used for the assignment of the 21 representative isolates. Our results show that the cellulolytic bacterial community is dominated by the Proteobacteria (70.05%), followed by the Actinobacteria (24.15%), the Firmicutes (4.35%), and the Bacteroidetes (1.45%). At the genus level, Gram-negative bacteria including Pseudomonas, Ochrobactrum, Rhizobium, Cellulosimicrobium, and Microbacterium were the predominant groups, but members of Bacillus, Dyadobacter, Siphonobacter, Paracoccus, Kaistia, Devosia, Labrys, Ensifer, Variovorax, Shinella, Citrobacter, and Stenotrophomonas were also found. Furthermore, our results suggest that a significant amount of bacterial diversity exists among the cellulolytic bacteria, and that Siphonobacter aquaeclarae, Cellulosimicrobium funkei, Paracoccus sulfuroxidans, Ochrobactrum cytisi, Ochrobactrum haematophilum, Kaistia adipata, Devosia riboflavina, Labrys neptuniae, Ensifer adhaerens, Shinella zoogloeoides, Citrobacter freundii, and Pseudomonas nitroreducens are reported to be cellulolytic for the first time in this study. Our results indicate that the scarab gut is an attractive source for the study of novel cellulolytic microorganisms and enzymes useful for cellulose degradation. PMID:22489111

  14. Bioaccumulation of Vanadium by Vanadium-Resistant Bacteria Isolated from the Intestine of Ascidia sydneiensis samea.

    PubMed

    Romaidi; Ueki, Tatsuya

    2016-06-01

    Isolation of naturally occurring bacterial strains from metal-rich environments has gained popularity due to the growing need for bioremediation technologies. In this study, we found that the vanadium concentration in the intestine of the vanadium-rich ascidian Ascidia sydneiensis samea could reach 0.67 mM, and thus, we isolated vanadium-resistant bacteria from the intestinal contents and determined the ability of each bacterial strain to accumulate vanadium and other heavy metals. Nine strains of vanadium-resistant bacteria were successfully isolated, of which two strains, V-RA-4 and S-RA-6, accumulated vanadium at a higher rate than did the other strains. The maximum vanadium absorption by these bacteria was achieved at pH 3, and intracellular accumulation was the predominant mechanism. Each strain strongly accumulated copper and cobalt ions, but accumulation of nickel and molybdate ions was relatively low. These bacterial strains can be applied to protocols for bioremediation of vanadium and heavy metal toxicity. PMID:27177911

  15. Functional characterization of bacteria isolated from ancient arctic soil exposes diverse resistance mechanisms to modern antibiotics.

    PubMed

    Perron, Gabriel G; Whyte, Lyle; Turnbaugh, Peter J; Goordial, Jacqueline; Hanage, William P; Dantas, Gautam; Desai, Michael M

    2015-01-01

    Using functional metagenomics to study the resistomes of bacterial communities isolated from different layers of the Canadian high Arctic permafrost, we show that microbial communities harbored diverse resistance mechanisms at least 5,000 years ago. Among bacteria sampled from the ancient layers of a permafrost core, we isolated eight genes conferring clinical levels of resistance against aminoglycoside, β-lactam and tetracycline antibiotics that are naturally produced by microorganisms. Among these resistance genes, four also conferred resistance against amikacin, a modern semi-synthetic antibiotic that does not naturally occur in microorganisms. In bacteria sampled from the overlaying active layer, we isolated ten different genes conferring resistance to all six antibiotics tested in this study, including aminoglycoside, β-lactam and tetracycline variants that are naturally produced by microorganisms as well as semi-synthetic variants produced in the laboratory. On average, we found that resistance genes found in permafrost bacteria conferred lower levels of resistance against clinically relevant antibiotics than resistance genes sampled from the active layer. Our results demonstrate that antibiotic resistance genes were functionally diverse prior to the anthropogenic use of antibiotics, contributing to the evolution of natural reservoirs of resistance genes.

  16. Antimicrobial activities of novel cultivable bacteria isolated from marine sponge Tedania anhelans

    NASA Astrophysics Data System (ADS)

    Zeng, Zhen; Zhao, Jing; Ke, Caihuan; Wang, Dexiang

    2013-05-01

    Marine sponge Tedania anhelans distributes throughout the intertidal zone of Fujian, southeastern China, and is a potential source of natural bioactive products. The sponge harbors a large number of bacterial groups that have been identified using various techniques, including fluorescent in situ hybridization (FISH). Fractionation of dissociated sponge allowed isolation of 25 bacterial species. Based on 16S rRNA gene sequencing, phylogenetic analysis attributed most of these eubacteria to α- Proteobacteria, γ- Proteobacteria, Cytophaga / Flavobacterium / Bacteroidetes (CFB group), and the family Bacillaceae of Gram-positive bacteria. In sequence similarity, five putatively novel species were identified with less than 98% similarity to other strains in the NCBI database. Tests for antimicrobial activities were performed against Gram-positive bacteria, Gram-negative bacteria, fungi, antitumor indicators Escherichia coli 343/591 (with DNA repair deficiency), regular E. coli 343/636 (with different DNA repair capacity), and 10 bacterial isolates exhibited inhibitory bioactivities. Among these strains, three isolates were detected involving function gene NRPS-A domains, which were most closely related to the amino acid sequences of linear gramicidin synthetase and pyoverdine synthetase. These results contribute to our knowledge of the microbes associated with marine sponges and further reveal novel bacterial resources for the screening of bioactive marine natural products.

  17. Thermophilic, anaerobic bacteria isolated from a deep borehole in granite in Sweden.

    PubMed

    Szewzyk, U; Szewzyk, R; Stenström, T A

    1994-03-01

    A borehole drilled to a total depth of 6779 m in granitic rock in Gravberg, Sweden, was sampled and examined for the presence of anaerobic, thermophilic, fermenting bacteria and sulfate-reducing bacteria. Growth in enrichment cultures was obtained only from water samples collected from a specific sampling depth in the borehole (3500 m). The hole was cased down to a depth of 5278 m and open to the formation below that level. All the water below 2000 m in depth standing in the borehole at the time of sampling must have entered at the 5278-m level or below, during a prior pumping operation. A strong salinity stratification certifies that no major amount of vertical mixing had taken place. The depth from which bacteria could be enriched was that of a pronounced local minimum of salinity. Pure cultures of thermophilic, anaerobic, fermenting bacteria were obtained with the following substrates: glucose, starch, xylan, ethanol, and lactate. The morphology and physiology of the glucose- and starch-degrading strains indicate a relationship to Thermoanaerobacter and Thermoanaerobium species. All but one of the newly isolated strains differ however from those by lacking acetate as a fermentation product. The glucose-degrading strain Gluc1 is phylogenetically related to Clostridium thermohydrosulfuricum, with an evolutionary distance based upon rRNA sequence comparisons of 3%. No sulfate-reducing or methanogenic bacteria were found.

  18. Application of immobilized synthetic anti-lipopolysaccharide peptides for the isolation and detection of bacteria.

    PubMed

    Sandetskaya, N; Engelmann, B; Brandenburg, K; Kuhlmeier, D

    2015-08-01

    The molecular detection of microorganisms in liquid samples generally requires their enrichment or isolation. The aim of our study was to evaluate the capture and pre-concentration of bacteria by immobilized particular cationic antimicrobial peptides, called synthetic anti-lipopolysaccharide peptides (SALP). For the proof-of-concept and screening of different SALP, the peptides were covalently immobilized on glass slides, and the binding of bacteria was confirmed by microscopic examination of the slides or their scanning, in case of fluorescent bacterial cells. The most efficient SALP was further tethered to magnetic beads. SALP beads were used for the magnetic capture of Escherichia coli in liquid samples. The efficiency of this strategy was evaluated using polymerase chain reaction (PCR). Covalently immobilized SALP were capable of capturing bacteria in liquid samples. However, PCR was hampered by the unspecific binding of DNA to the positively charged peptide. We developed a method for DNA recovery by the enzymatic digestion of the peptide, which allowed for a successful PCR, though the method had its own adverse impact on the detection and, thus, did not allow for the reliable quantitative analysis of the pathogen enrichment. Immobilized SALP can be used as capture molecules for bacteria in liquid samples and can be recommended for the design of the assays or decontamination of the fluids. For the accurate subsequent detection of bacteria, DNA-independent methods should be used.

  19. Comparative genomics of Roseobacter clade bacteria isolated from the accessory nidamental gland of Euprymna scolopes

    PubMed Central

    Collins, Andrew J.; Fullmer, Matthew S.; Gogarten, Johann P.; Nyholm, Spencer V.

    2015-01-01

    The accessory nidamental gland (ANG) of the female Hawaiian bobtail squid, Euprymna scolopes, houses a consortium of bacteria including members of the Flavobacteriales, Rhizobiales, and Verrucomicrobia but is dominated by members of the Roseobacter clade (Rhodobacterales) within the Alphaproteobacteria. These bacteria are deposited into the jelly coat of the squid’s eggs, however, the function of the ANG and its bacterial symbionts has yet to be elucidated. In order to gain insight into this consortium and its potential role in host reproduction, we cultured 12 Rhodobacterales isolates from ANGs of sexually mature female squid and sequenced their genomes with Illumina sequencing technology. For taxonomic analyses, the ribosomal proteins of 79 genomes representing both roseobacters and non-roseobacters along with a separate MLSA analysis of 33 housekeeping genes from Roseobacter organisms placed all 12 isolates from the ANG within two groups of a single Roseobacter clade. Average nucelotide identity analysis suggests the ANG isolates represent three genera (Leisingera, Ruegeria, and Tateyamaria) comprised of seven putative species groups. All but one of the isolates contains a predicted Type VI secretion system, which has been shown to be important in secreting signaling and/or effector molecules in host–microbe associations and in bacteria–bacteria interactions. All sequenced genomes also show potential for secondary metabolite production, and are predicted to be involved with the production of acyl homoserine lactones (AHLs) and/or siderophores. An AHL bioassay confirmed AHL production in three tested isolates and from whole ANG homogenates. The dominant symbiont, Leisingera sp. ANG1, showed greater viability in iron-limiting conditions compared to other roseobacters, possibly due to higher levels of siderophore production. Future comparisons will try to elucidate novel metabolic pathways of the ANG symbionts to understand their putative role in host

  20. Isolation, fingerprinting and genetic identification of indigenous PAHs degrading bacteria from oil-polluted soils.

    PubMed

    Alrumman, Sulaiman A; Hesham, Abd El-Latif; Alamri, Saad A

    2016-01-01

    In the present study, thirty five bacterial isolates were obtained from hydrocarbon-contaminated soil samples using an enrichment method. These isolates were tested to grow on mineral salt medium containing anthracene or phenanthrene as sole carbon source. Only five isolates showed the ability to degrade these compounds. RAPD-PCR fingerprinting was carried out for the five isolates, and the DNA patterns revealed that there was no similarity among the examined bacteria whenever the RFLP using four restriction enzymes HaeIII, Msp1, Hinf1 and Taq1 failed to differentiate among them. Five bacterial isolates were grown in high concentration of anthracene and phenanthrene (4% w/v). Two bacterial isolates were selected due to their high ability to grow in the presence of high concentrations of anthracene and phenanthrene. The isolates were identified as Bacillus flexus and Ochrobactrum anthropi, based on DNA sequencing of amplified 16S rRNA gene and phylogenetic analysis. Finally, the ability of these bacterial strains to tolerate and remove different PAHs looked promising for application in bioremediation technologies.

  1. Phylogeny of bacteria isolated from Rhabditis sp. (Nematoda) and identification of novel entomopathogenic Serratia marcescens strains.

    PubMed

    Tambong, James T

    2013-02-01

    Twenty-five bacterial strains isolated from entomopathogenic nematodes were characterized to the genus level by 16S rRNA phylogeny and BLAST analyses. Bacteria strains isolated could be affiliated with seven genera. Microbacterium-like isolates phylogenetically affiliated with M. oxydans while those of Serratia were highly similar to S. marcescens. 16S rRNA sequences of Bacillus isolates matched those of both B. mycoides and B. weihenstephanesis. One isolate each matched Pseudomonas mosselii, Rheinheimera aquimaris, Achromobacter marplatensis, or Staphylococcus hominis. Serratia isolates were examined further for their pathogenicity to Galleria mellonella larvae. All the Serratia isolates exhibited potent pathogenicity toward G. mellonella larvae and possessed a metalloprotease gene encoding for a novel serralysin-like protein. The nucleotide sequence of the metalloprotease gene had 60 synonymous and 8 nonsynonymous substitutions when compared to the closest genBank entry, S. marcescens E-15, with an insertion of a new aspartic acid residue. Tajima's test for equality of evolutionary rate was significant between the metalloprotease gene sequence of S. marcescens strain DOAB 216-82 (this study) and strain E-15. This new insecticidal metalloprotease gene and/or its product could have applications in agricultural biotechnology.

  2. Isolation, fingerprinting and genetic identification of indigenous PAHs degrading bacteria from oil-polluted soils.

    PubMed

    Alrumman, Sulaiman A; Hesham, Abd El-Latif; Alamri, Saad A

    2016-01-01

    In the present study, thirty five bacterial isolates were obtained from hydrocarbon-contaminated soil samples using an enrichment method. These isolates were tested to grow on mineral salt medium containing anthracene or phenanthrene as sole carbon source. Only five isolates showed the ability to degrade these compounds. RAPD-PCR fingerprinting was carried out for the five isolates, and the DNA patterns revealed that there was no similarity among the examined bacteria whenever the RFLP using four restriction enzymes HaeIII, Msp1, Hinf1 and Taq1 failed to differentiate among them. Five bacterial isolates were grown in high concentration of anthracene and phenanthrene (4% w/v). Two bacterial isolates were selected due to their high ability to grow in the presence of high concentrations of anthracene and phenanthrene. The isolates were identified as Bacillus flexus and Ochrobactrum anthropi, based on DNA sequencing of amplified 16S rRNA gene and phylogenetic analysis. Finally, the ability of these bacterial strains to tolerate and remove different PAHs looked promising for application in bioremediation technologies. PMID:26930863

  3. Incidence and transferability of antibiotic resistance in the enteric bacteria isolated from hospital wastewater.

    PubMed

    Alam, Mohammad Zubair; Aqil, Farrukh; Ahmad, Iqbal; Ahmad, Shamim

    2013-01-01

    This study reports the occurrence of antibiotic resistance and production of β-lactamases including extended spectrum beta-lactamases (ESβL) in enteric bacteria isolated from hospital wastewater. Among sixty-nine isolates, tested for antibiotic sensitivity, 73.9% strains were resistant to ampicillin followed by nalidixic acid (72.5%), penicillin (63.8%), co-trimoxazole (55.1%), norfloxacin (53.6%), methicillin (52.7%), cefuroxime (39.1%), cefotaxime (23.2%) and cefixime (20.3%). Resistance to streptomycin, chloramphenicol, nitrofurantoin, tetracycline, and doxycycline was recorded in less than 13% of the strains. The minimum inhibitory concentration (MIC) showed a high level of resistance (800-1600 μg/mL) to one or more antibiotics. Sixty three (91%) isolates produced β-lactamases as determined by rapid iodometric test. Multiple antibiotic resistances were noted in both among ESβL and non-ESβL producers. The β-lactamases hydrolyzed multiple substrates including penicillin (78.8% isolates), ampicillin (62.3%), cefodroxil (52.2%), cefotoxime (21.7%) and cefuroxime (18.8%). Fifteen isolates producing ESβLs were found multidrug resistant. Four ESβL producing isolates could transfer their R-plasmid to the recipient strain E. coli K-12 with conjugation frequency ranging from 7.0 × 10(-3) to 8.8 × 10(-4). The findings indicated that ESβL producing enteric bacteria are common in the waste water. Such isolates may disseminate the multiple antibiotic resistance traits among bacterial community through genetic exchange mechanisms and thus requires immediate attention.

  4. Biochemical and molecular characterization of high population density bacteria isolated from sunflower.

    PubMed

    Guerra Pinheiro de Goes, Kelly Campos; de Castro Fisher, Maria Luisa; Cattelan, Alexandre José; Nogueira, Marco Antonio; Portela de Carvalho, Claudio Guilherme; Martinez de Oliveira, Andre Luiz

    2012-04-01

    Natural and beneficial associations between plants and bacteria have demonstrated potential commercial application for several agricultural crops. The sunflower has acquired increasing importance in Brazilian agribusiness owing to its agronomic characteristics such as the tolerance to edaphoclimatic variations, resistance to pests and diseases, and adaptation to the implements commonly used for maize and soybean, as well as the versatility of the products and by-products obtained from its cultivation. A study of the cultivable bacteria associated with two sunflower cultivars, using classical microbiological methods, successfully obtained isolates from different plant tissues (roots, stems, florets, and rhizosphere). Out of 57 plantgrowth- promoting isolates obtained, 45 were identified at the genus level and phylogenetically positioned based on 16S rRNA gene sequencing: 42 Bacillus (B. subtilis, B. cereus, B. thuringiensis, B. pumilus, B. megaterium, and Bacillus sp.) and 3 Methylobacterium komagatae. Random amplified polymorphic DNA (RAPD) analysis showed a broad diversity among the Bacillus isolates, which clustered into 2 groups with 75% similarity and 13 subgroups with 85% similarity, suggesting that the genetic distance correlated with the source of isolation. The isolates were also analyzed for certain growth-promoting activities. Auxin synthesis was widely distributed among the isolates, with values ranging from 93.34 to 1653.37 microM auxin per microng of protein. The phosphate solubilization index ranged from 1.25 to 3.89, and siderophore index varied from 1.15 to 5.25. From a total of 57 isolates, 3 showed an ability to biologically fix atmospheric nitrogen, and 7 showed antagonism against the pathogen Sclerotinia sclerotiorum. The results of biochemical characterization allowed identification of potential candidates for the development of biofertilizers targeted to the sunflower crop.

  5. Identification and characterization of psychrotolerant coliform bacteria isolated from pasteurized fluid milk.

    PubMed

    Masiello, S N; Martin, N H; Trmčić, A; Wiedmann, M; Boor, K J

    2016-01-01

    The presence of coliform bacteria in pasteurized fluid milk typically indicates that product contamination occurred downstream of the pasteurizer, but it may also indicate pasteurization failure. Although coliform detection is frequently used as a hygiene indicator for dairy products, our understanding of the taxonomic and phenotypic coliform diversity associated with dairy products is surprisingly limited. Therefore, using Petrifilm Coliform Count plates (3M, St. Paul, MN), we isolated coliforms from high-temperature, short-time (HTST)-pasteurized fluid milk samples from 21 fluid milk processing plants in the northeast United States. Based on source information and initial characterization using partial 16S rDNA sequencing, 240 nonredundant isolates were obtained. The majority of these isolates were identified as belonging to the genera Enterobacter (42% of isolates), Hafnia (13%), Citrobacter (12%), Serratia (10%), and Raoultella (9%); additional isolates were classified into the genera Buttiauxella, Cedecea, Kluyvera, Leclercia, Pantoea, and Rahnella. A subset of 104 representative isolates was subsequently characterized phenotypically. Cold growth analysis in skim milk broth showed that all isolates displayed at least a 2-log increase over 10 d at 6°C; the majority of isolates (n=74) displayed more than a 5-log increase. In total, 43% of the representative isolates displayed lipolysis when incubated on spirit blue agar at 6°C for 14 d, whereas 71% of isolates displayed proteolysis when incubated on skim milk agar at 6°C for 14 d. Our data indicate that a considerable diversity of coliforms is found in HTST-pasteurized fluid milk and that a considerable proportion of these coliforms have phenotypic characteristics that will allow them to cause fluid milk spoilage. PMID:26547640

  6. Identification and characterization of psychrotolerant coliform bacteria isolated from pasteurized fluid milk.

    PubMed

    Masiello, S N; Martin, N H; Trmčić, A; Wiedmann, M; Boor, K J

    2016-01-01

    The presence of coliform bacteria in pasteurized fluid milk typically indicates that product contamination occurred downstream of the pasteurizer, but it may also indicate pasteurization failure. Although coliform detection is frequently used as a hygiene indicator for dairy products, our understanding of the taxonomic and phenotypic coliform diversity associated with dairy products is surprisingly limited. Therefore, using Petrifilm Coliform Count plates (3M, St. Paul, MN), we isolated coliforms from high-temperature, short-time (HTST)-pasteurized fluid milk samples from 21 fluid milk processing plants in the northeast United States. Based on source information and initial characterization using partial 16S rDNA sequencing, 240 nonredundant isolates were obtained. The majority of these isolates were identified as belonging to the genera Enterobacter (42% of isolates), Hafnia (13%), Citrobacter (12%), Serratia (10%), and Raoultella (9%); additional isolates were classified into the genera Buttiauxella, Cedecea, Kluyvera, Leclercia, Pantoea, and Rahnella. A subset of 104 representative isolates was subsequently characterized phenotypically. Cold growth analysis in skim milk broth showed that all isolates displayed at least a 2-log increase over 10 d at 6°C; the majority of isolates (n=74) displayed more than a 5-log increase. In total, 43% of the representative isolates displayed lipolysis when incubated on spirit blue agar at 6°C for 14 d, whereas 71% of isolates displayed proteolysis when incubated on skim milk agar at 6°C for 14 d. Our data indicate that a considerable diversity of coliforms is found in HTST-pasteurized fluid milk and that a considerable proportion of these coliforms have phenotypic characteristics that will allow them to cause fluid milk spoilage.

  7. Biogeochemistry and Genetic Potential related to Denitrification of Heterotrophic Bacteria isolated from Lake Vida Cryobrine

    NASA Astrophysics Data System (ADS)

    Trubl, G.; Kuhn, E.; Ichimura, A.; Fritsen, C. H.; Murray, A. E.

    2012-12-01

    Lake Vida, one of the largest lakes in McMurdo Dry Valleys, Antarctica, is a thick block of ice permeated by brine channels below 16 m that contain the highest levels of nitrous oxide (N2O) that have been reported from a terrestrial environment (86.6 ± 5.9 μM). The subzero -13.4oC brine (18% salinity) has an unusual geochemistry with high levels of iron, dissolved organic carbon, nitrate, and ammonium. A number of heterotrophic bacteria were cultivated from this unusual, extreme ecosystem that has been isolated for at least three thousand years. The aim of this research was to phylogenetically characterize the bacterial isolates (using 16S ribosomal RNA analysis) and investigate their denitrifying abilities and genetic potential related to key reactions in the denitrification cycle. Fifteen phylotypes were isolated from Lake Vida brine among three phyla: Gammaproteobacteria, Actinobacteria, and Firmicutes. Based on the 16S ribosomal RNA analysis, Marinobacter was the most abundant (56%) genus identified among the 57 isolates. The other isolates were related to the genera Psychrobacter, Exiguobacterium, Kocuria, and Microbacterium. Representatives of each phylotype were characterized and verified for: (1) Nitrate (NO3-) reduction to either N2O or dinitrogen (N2) by Gas Chromatography; (2) presence of the genes nirK or nirS for NO3- reduction and nosZ for nitric oxide (NO) reduction by polymerase chain reaction (PCR); and (3) growth response to salinity and temperature gradients. Thirty five of the Lake Vida isolates produced either N2O or N2 coupled to cell growth. All 57 isolates have grown across a 32°C temperature range (-10°C to 22°C) and 54 isolates were halotolerant bacteria (growing in 0% to 16% salinity), while the last three isolates were halophilic. Electron microscopy revealed membrane vesicles and extracellular polymeric substances (EPS) around the Lake Vida isolates, which may be a survival adaptation. Investigating the denitrification and other

  8. Isolation and characterization of methane utilizing bacteria from wetland paddy ecosystem.

    PubMed

    Jhala, Y K; Vyas, R V; Shelat, H N; Patel, H K; Patel, H K; Patel, K T

    2014-06-01

    Methylotrophic bacteria which are known to utilize C1 compounds including methane. Research during past few decades increased the interest in finding out novel genera of methane degrading bacteria to efficiently utilize methane to decrease global warming effect. Moreover, evaluation of certain known plant growth promoting strains for their methane degrading potential may open up a new direction for multiple utility of such cultures. In this study, efficient methylotrophic cultures were isolated from wetland paddy fields of Gujarat. From the overall morphological, biochemical and molecular characterization studies, the isolates were identified and designated as Bacillus aerius AAU M 8; Rhizobium sp. AAU M 10; B. subtilis AAU M 14; Paenibacillus illinoisensis AAU M 17 and B. megaterium AAU M 29. Gene specific PCR analysis of the isolates, P. illinoisensis, B. aerius, Rhizobium sp. and B. subtilis showed presence of pmoA gene encoding α subunit particulate methane monooxygenase cluster. B. megaterium, P. illinoisensis, Rhizobium sp. and Methylobacterium extrorquens showed presence of mmoX gene encoding α subunit of the hydroxylase component of the soluble methane monooxygenase cluster. P. illinoisensis and Rhizobium sp. showed presence mxaF gene encoding α subunit region of methanol dehydrogenase gene cluster showing that both isolates are efficient utilizers of methane. To the best of our knowledge, this is the first time report showing presence of methane degradation enzymes and genes within the known PGPB group of organisms from wet land paddy agro-ecosystem, which is considered as one of the leading methane producer.

  9. Isolation and Physiological Characterization of Psychrophilic Denitrifying Bacteria from Permanently Cold Arctic Fjord Sediments (Svalbard, Norway)

    NASA Technical Reports Server (NTRS)

    Canion, Andy; Prakash, Om; Green, Stefan J.; Jahnke, Linda; Kuypers, Marcel M. M.; Kostka, Joel E.

    2013-01-01

    A large proportion of reactive nitrogen loss from polar sediments is mediated by denitrification, but microorganisms mediating denitrification in polar environments remain poorly characterized. A combined approach of most-probable-number (MPN) enumeration, cultivation and physiological characterization was used to describe psychrophilic denitrifying bacterial communities in sediments of three Arctic fjords in Svalbard (Norway). A MPN assay showed the presence of 10(sup 3)-10(sup 6) cells of psychrophilic nitrate-respiring bacteria g(sup -1) of sediment. Fifteen strains within the Proteobacteria were isolated using a systematic enrichment approach with organic acids as electron donors and nitrate as an electron acceptor. Isolates belonged to five genera, including Shewanella, Pseudomonas, Psychromonas (Gammaproteobacteria), Arcobacter (Epsilonproteobacteria) and Herminiimonas (Betaproteobacteria). All isolates were denitrifiers, except Shewanella, which exhibited the capacity for dissimilatory nitrate reduction to ammonium (DNRA). Growth from 0 to 40 degC demonstrated that all genera except Shewanella were psychrophiles with optimal growth below 15 degC, and adaptation to low temperature was demonstrated as a shift from primarily C16:0 saturated fatty acids to C16:1 monounsaturated fatty acids at lower temperatures. This study provides the first targeted enrichment and characterization of psychrophilic denitrifying bacteria from polar sediments, and two genera, Arcobacter and Herminiimonas, are isolated for the first time from permanently cold marine sediments.

  10. Antimicrobial resistance in some gram-negative bacteria isolated from the bovine ejaculate.

    PubMed

    Kilburn, C; Rooks, D J; McCarthy, A J; Murray, R D

    2013-06-01

    The bacterial load and degree of antibiotic resistance present in untreated and antibiotic-treated semen samples were investigated in five bulls standing at a cattle-breeding centre. Bacterial load was determined by colony counts from semen samples cultured on brain heart infusion and nutrient agar plates. Antibiotic resistance in these bacteria was assessed by measuring the diameter of bacterial growth inhibition zones around discs containing different concentrations of antibiotics. Representative antibiotic-resistant bacterial isolates were selected for identification. Untreated semen contained few culturable bacteria, and all were completely sensitive to gentamycin, spectinomycin and lincomycin: six of the isolates showed some resistance to tylosin. In semen to which antibiotics had been added as part of the routine production process, two isolates were sensitive to all of the antibiotics tested, and the remainder were resistant to all. Resistant Gram-negative isolates that were identified included Pseudomonas and Stenotrophomonas spp. both in the class Gammaproteobacteria and a Sphingomonas sp. which is in the class Alphaproteobacteria. PMID:23331295

  11. Characterization of heterotrophic bacteria isolated from the biofilm of a kitchen sink.

    PubMed

    Furuhata, Katsunori; Ishizaki, Naoto; Fukuyama, Masafumi

    2010-03-01

    Heterotrophic bacteria constituting the biofilm produced in a kitchen sink drain were analyzed, and the biofilm formation abilities and the hydrophobicity of the cell surface layer were measured for the isolates. When the biofilm sample was cultured at 36 degrees C and 25 degrees C for 7 days, there were about 10 times more colonies on oligotrophic R2A agar medium than on eutrophic BHI agar medium. From isolates from the biofilm sample, 13 bacterial species were detected. To examine the biofilm formation ability of these strains, we measured the absorbance (OD570) by crystal violet staining. The absorbance of Brevibacterium casei 7-R-36-1 was the highest (3.029). In the comparison of the absorbance values between genera, Brevibacterium spp. (4 strains) showed the highest absorbance (mean: 2.056), followed by K. pneumoniae (4 strains) with a mean of 1.111. Regarding the hydrophobicity of the isolates, the values ranged from 0.002 for P. nitroreducens (strain 1-B-36-2) to 0.096 for M. lacticum (strain 5-R-25-2). The hydrophobicity values were generally low, and the cell surface layer of all tested strains was highly hydrophilic. The diversity of species of bacteria in the biofilm sample produced in the kitchen sink drain was recognized, and all the isolates had biofilm formation abilities.

  12. Isolation of maize soil and rhizosphere bacteria with antagonistic activity against Aspergillus flavus and Fusarium verticillioides.

    PubMed

    Palumbo, Jeffrey D; O'Keeffe, Teresa L; Abbas, Hamed K

    2007-07-01

    Bacterial isolates from Mississippi maize field soil and maize rhizosphere samples were evaluated for their potential as biological control agents against Aspergillus flavus and Fusarium verticillioides. Isolated strains were screened for antagonistic activities in liquid coculture against A. flavus and on agar media against A. flavus and F. verticillioides. We identified 221 strains that inhibited growth of both fungi. These bacteria were further differentiated by their production of extracellular enzymes that hydrolyzed chitin and yeast cell walls and by production of antifungal metabolites. Based on molecular and nutritional identification of the bacterial strains, the most prevalent genera isolated from rhizosphere samples were Burkholderia and Pseudomonas, and the most prevalent genera isolated from nonrhizosphere soil were Pseudomonas and Bacillus. Less prevalent genera included Stenotrophomonas, Agrobacterium, Variovorax, Wautersia, and several genera of coryneform and enteric bacteria. In quantitative coculture assays, strains of P. chlororaphis and P. fluorescens consistently inhibited growth of A. flavus and F. verticillioides in different media. These results demonstrate the potential for developing individual biocontrol agents for simultaneous control of the mycotoxigenic A. flavus and F. verticillioides. PMID:17685333

  13. Heavy-metal resistance in Gram-negative bacteria isolated from Kongsfjord, Arctic.

    PubMed

    Neethu, C S; Mujeeb Rahiman, K M; Saramma, A V; Mohamed Hatha, A A

    2015-06-01

    Isolation and characterization of heterotrophic Gram-negative bacteria was carried out from the sediment and water samples collected from Kongsfjord, Arctic. In this study, the potential of Arctic bacteria to tolerate heavy metals that are of ecological significance to the Arctic (selenium (Se), mercury (Hg), cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn)) was investigated. Quantitative assay of 130 isolates by means of plate diffusion and tube dilution methods was carried out by incorporation of different concentrations of metals. Growth in Se and Pb at a concentration of 3000 μg/L was significantly lower (P≤0.0001) than at 2000 μg/L. The minimum inhibitory concentration for Cd and Hg was 50 μg/L (P≤0.0001, F=264.23 and P≤0.0001, F=291.08, respectively) even though in the tube dilution test, Hg-containing tubes showed much less growth, revealing its superior toxicity to Cd. Thus, the level of toxicity of heavy metals was found to be in the order of Hg>Cd>Cu>Zn>Pb>Se. Multiple-metal-resistant isolates were investigated for their resistance against antibiotics, and a positive correlation was observed between antibiotic and metal resistance for all the isolates tested. The resistant organisms thus observed might influence the organic and inorganic cycles in the Arctic and affect the ecosystem.

  14. Isolation of acetogenic bacteria that induce biocorrosion by utilizing metallic iron as the sole electron donor.

    PubMed

    Kato, Souichiro; Yumoto, Isao; Kamagata, Yoichi

    2015-01-01

    Corrosion of iron occurring under anoxic conditions, which is termed microbiologically influenced corrosion (MIC) or biocorrosion, is mostly caused by microbial activities. Microbial activity that enhances corrosion via uptake of electrons from metallic iron [Fe(0)] has been regarded as one of the major causative factors. In addition to sulfate-reducing bacteria and methanogenic archaea in marine environments, acetogenic bacteria in freshwater environments have recently been suggested to cause MIC under anoxic conditions. However, no microorganisms that perform acetogenesis-dependent MIC have been isolated or had their MIC-inducing mechanisms characterized. Here, we enriched and isolated acetogenic bacteria that induce iron corrosion by utilizing Fe(0) as the sole electron donor under freshwater, sulfate-free, and anoxic conditions. The enriched communities produced significantly larger amounts of Fe(II) than the abiotic controls and produced acetate coupled with Fe(0) oxidation prior to CH4 production. Microbial community analysis revealed that Sporomusa sp. and Desulfovibrio sp. dominated in the enrichments. Strain GT1, which is closely related to the acetogen Sporomusa sphaeroides, was eventually isolated from the enrichment. Strain GT1 grew acetogenetically with Fe(0) as the sole electron donor and enhanced iron corrosion, which is the first demonstration of MIC mediated by a pure culture of an acetogen. Other well-known acetogenic bacteria, including Sporomusa ovata and Acetobacterium spp., did not grow well on Fe(0). These results indicate that very few species of acetogens have specific mechanisms to efficiently utilize cathodic electrons derived from Fe(0) oxidation and induce iron corrosion.

  15. [Isolation and Identification of Petroleum Degradation Bacteria and Interspecific Interactions Among Four Bacillus Strains].

    PubMed

    Wang, Jia-nan; Shi, Yan-yun; Zheng, Li-yan; Wang, Zhe; Cai, Zhang; Liu, Jie

    2015-06-01

    Six petroleum-degrading strains were isolated from oil-contaminated soil at Dagang oil field and oil sewage on Bohai offshore drilling platform in Tianjin using enrichment culture and isolation method. The physiological biochemical test together with 16S rDNA sequencing analysis indicated that they belonged to Bacillus (S1, S2, S3, S4), Pseudomonas (W1) and Ochrobactrum (W2), respectively. The strain S3 had the maximum degradation rate of alkane (41.3%) and aromatic hydrocarbon (30.9%) among all isolated strains showing the better degradation efficiency by endogenous bacteria when compared to that by the exogenous bacteria. The four Bacillus strains were used to construct microbiome, thereafter subjected to petroleum degradation efficiency test and analyzed. The results showed that microbiome F3 consisting of S1 and S4 had the maximum degradation rates of alkane (50.5%) and aromatic hydrocarbon (54.0%), which were 69.9% and 156.1% higher than those by single bacterium, respectively. Furthermore, they were 22.1% and 74.6% respectively higher than those by the most optimal degradation bacterium S3. Microbiome F4 consisting of S2 and S3 had the minimum degradation rates of alkane (18.5%) and aromatic hydrocarbon (18.9%) which were 55.3% and 39.0% lower than the degradation rates of single bacterium, respectively. The results also demonstrated that there were both microbial synergy promotion and antagonism inhibition among bacteria of the same genus in the petroleum degradation period. Bacteria with close affinity in Bacillus genus displayed mainly promoted petroleum degradation effect.

  16. [Isolation and Identification of Petroleum Degradation Bacteria and Interspecific Interactions Among Four Bacillus Strains].

    PubMed

    Wang, Jia-nan; Shi, Yan-yun; Zheng, Li-yan; Wang, Zhe; Cai, Zhang; Liu, Jie

    2015-06-01

    Six petroleum-degrading strains were isolated from oil-contaminated soil at Dagang oil field and oil sewage on Bohai offshore drilling platform in Tianjin using enrichment culture and isolation method. The physiological biochemical test together with 16S rDNA sequencing analysis indicated that they belonged to Bacillus (S1, S2, S3, S4), Pseudomonas (W1) and Ochrobactrum (W2), respectively. The strain S3 had the maximum degradation rate of alkane (41.3%) and aromatic hydrocarbon (30.9%) among all isolated strains showing the better degradation efficiency by endogenous bacteria when compared to that by the exogenous bacteria. The four Bacillus strains were used to construct microbiome, thereafter subjected to petroleum degradation efficiency test and analyzed. The results showed that microbiome F3 consisting of S1 and S4 had the maximum degradation rates of alkane (50.5%) and aromatic hydrocarbon (54.0%), which were 69.9% and 156.1% higher than those by single bacterium, respectively. Furthermore, they were 22.1% and 74.6% respectively higher than those by the most optimal degradation bacterium S3. Microbiome F4 consisting of S2 and S3 had the minimum degradation rates of alkane (18.5%) and aromatic hydrocarbon (18.9%) which were 55.3% and 39.0% lower than the degradation rates of single bacterium, respectively. The results also demonstrated that there were both microbial synergy promotion and antagonism inhibition among bacteria of the same genus in the petroleum degradation period. Bacteria with close affinity in Bacillus genus displayed mainly promoted petroleum degradation effect. PMID:26387332

  17. Isolation of Typical Marine Bacteria by Dilution Culture: Growth, Maintenance, and Characteristics of Isolates under Laboratory Conditions

    PubMed Central

    Schut, Frits; de Vries, Egbert J.; Gottschal, Jan C.; Robertson, Betsy R.; Harder, Wim; Prins, Rudolf A.; Button, Don K.

    1993-01-01

    Marine bacteria in Resurrection Bay near Seward, Alaska, and in the central North Sea off the Dutch coast were cultured in filtered autoclaved seawater following dilution to extinction. The populations present before dilution varied from 0.11 × 109 to 1.07 × 109 cells per liter. The mean cell volume varied between 0.042 and 0.074 μm3, and the mean apparent DNA content of the cells ranged from 2.5 to 4.7 fg of DNA per cell. All three parameters were determined by high-resolution flow cytometry. All 37 strains that were obtained from very high dilutions of Resurrection Bay and North Sea samples represented facultatively oligotrophic bacteria. However, 15 of these isolates were eventually obtained from dilution cultures that could initially be cultured only on very low-nutrient media and that could initially not form visible colonies on any of the agar media tested, indicating that these cultures contained obligately oligotrophic bacteria. It was concluded that the cells in these 15 dilution cultures had adapted to growth under laboratory conditions after several months of nutrient deprivation prior to isolation. From the North Sea experiment, it was concluded that the contribution of facultative oligotrophs and eutrophs to the total population was less than 1% and that while more than half of the population behaved as obligately oligotrophic bacteria upon first cultivation in the dilution culture media, around 50% could not be cultured at all. During one of the Resurrection Bay experiments, 53% of the dilution cultures obtained from samples diluted more than 2.5 × 105 times consisted of such obligate oligotrophs. These cultures invariably harbored a small rod-shaped bacterium with a mean cell volume of 0.05 to 0.06 μm3 and an apparent DNA content of 1 to 1.5 fg per cell. This cell type had the dimensions of ultramicrobacteria. Isolates of these ultramicrobacterial cultures that were eventually obtained on relatively high-nutrient agar plates were, with respect

  18. Utilization of Vinegar for Isolation of Cellulose Producing Acetic Acid Bacteria

    SciTech Connect

    Aydin, Y. Andelib; Aksoy, Nuran Deveci

    2010-06-17

    Wastes of traditionally fermented Turkish vinegar were used in the isolation of cellulose producing acetic acid bacteria. Waste material was pre-enriched in Hestrin-Schramm medium and microorganisms were isolated by plating dilution series on HS agar plates The isolated strains were subjected to elaborate biochemical and physiological tests for identification. Test results were compared to those of reference strains Gluconacetobacter xylinus DSM 46604, Gluconacetobacter hansenii DSM 5602 and Gluconacetobacter liquefaciens DSM 5603. Seventeen strains, out of which only three were found to secrete the exopolysaccharide cellulose. The highest cellulose yield was recorded as 0.263+-0.02 g cellulose L{sup -1} for the strain AS14 which resembled Gluconacetobacter hansenii in terms of biochemical tests.

  19. Utilization of Vinegar for Isolation of Cellulose Producing Acetic Acid Bacteria

    NASA Astrophysics Data System (ADS)

    Aydin, Y. Andelib; Aksoy, Nuran Deveci

    2010-06-01

    Wastes of traditionally fermented Turkish vinegar were used in the isolation of cellulose producing acetic acid bacteria. Waste material was pre-enriched in Hestrin-Schramm medium and microorganisms were isolated by plating dilution series on HS agar plates The isolated strains were subjected to elaborate biochemical and physiological tests for identification. Test results were compared to those of reference strains Gluconacetobacter xylinus DSM 46604, Gluconacetobacter hansenii DSM 5602 and Gluconacetobacter liquefaciens DSM 5603. Seventeen strains, out of which only three were found to secrete the exopolysaccharide cellulose. The highest cellulose yield was recorded as 0.263±0.02 g cellulose L-1 for the strain AS14 which resembled Gluconacetobacter hansenii in terms of biochemical tests.

  20. The diversity of bacteria isolated from antarctic freshwater reservoirs possessing the ability to produce polyhydroxyalkanoates.

    PubMed

    Ciesielski, Slawomir; Górniak, Dorota; Możejko, Justyna; Świątecki, Aleksander; Grzesiak, Jakub; Zdanowski, Marek

    2014-11-01

    The diversity of polyhydroxyalkanoates-producing bacteria in freshwater reservoirs in the Ecology Glacier foreland, Antarctica, was examined by a cultivation-dependent method. Isolated strains were analyzed phylogenetically by 16S rRNA gene sequencing, and classified as members of Alpha-, Beta-, or Gammaproteobacteria classes. Polymerase chain reaction was used to detect PHA synthase genes. Potential polyhydroxyalkanoates (PHAs) producers belonging mainly to Pseudomonas sp., and Janthinobacterium sp. were isolated from all five sampling sites, suggesting that PHA synthesis is a common bacterial feature at pioneer sites. All Pseudomonas strains had the genetic potential to synthesize medium-chain-length PHAs, whereas some isolated Janthinobacterium strains might produce short-chain-length PHAs or medium-chain-length PHAs. It is the first report revealing that Janthinobacterium species could have the potential to produce medium-chain-length PHAs.

  1. Biosequestration of copper by bacteria isolated from an abandoned mine by using microbially induced calcite precipitation.

    PubMed

    Kang, Chang-Ho; Shin, YuJin; Anbu, Periasamy; Nam, In-Hyun; So, Jae-Seong

    2016-09-12

    Abandoned mine sites are frequently polluted with high concentrations of heavy metals. In this study, 25 calcite-forming bacteria were newly isolated from the soil of an abandoned metal mine in Korea. Based on their urease activity, calcite production, and resistance to copper toxicity, four isolates were selected and further identified by 16S rRNA gene sequencing. Among the isolates, Sporosarcina soli B-22 was selected for subsequent copper biosequestration studies, using the sand impermeability test by production of calcite and extracellular polymeric substance. High removal rates (61.8%) of copper were obtained when the sand samples were analyzed using an inductively coupled plasma-optical emission spectrometer following 72 h of incubation. Scanning electron microscopy showed that the copper carbonate precipitates had a diameter of approximately 5-10 μm. X-ray diffraction further confirmed the presence of copper carbonate and calcium carbonate crystals. PMID:27488956

  2. [Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibacterial agents (2009)].

    PubMed

    Goto, Hajime; Kumagai, Shigeru

    2015-02-01

    From October 2009 to September 2010, we collected the specimen from 432 patients with lower respiratory tract infections in 16 institutions in Japan, and investigated the susceptibilities of isolated bacteria to various antibacterial agents and patients' characteristics. All of 479 strains that were isolated from specimen (mainly from sputum) and assumed to be bacteria causing in infection, were examined. The isolated bacteria were: Staphylococcus aureus 90, Streptococcus pneumoniae 74, Haemophilus influenzae 82, Pseudomonas aeruginosa (non-mucoid) 60, P. aeruginosa (mucoid) 31, Klebsiella pneumoniae 41, and Moraxella catarrhalis 34. Of 90 S. aureus strains, those with 2 μg/mL or less of MIC of oxacillin (methicillin-susceptible S. aureus: MSSA) and those with 4 μg/mL or more of MIC of oxacillin (methicillin-resistant S. aureus: MRSA) were 43 (47.8%) and 47 (52.2%) strains, respectively. Against MSSA, imipenem had the most potent antibacterial activity and inhibited the growth of all strains at 0.063 μg/mL or less. Against MRSA, vancomycin and arbekacin showed the potent activity and inhibited the growth of all the strains at 2 and 4 μg/mL, respectively. Linezolid also showed the great activity and inhibited the growth of all the strains at 2 μg/mL. Carbapenems and penems showed the most potent activities against S. pneumoniae and panipenem inhibited the growth of all the strains at 0.125 μg/mL. Imipenem and faropenem also had a preferable activity and inhibited the growth of all the strains at 0.25 and 0.5 μg/mL, respectively. In contrast, there were high-resistant strains (MIC: > 128 μg/mL) for erythromycin (51.4%) and clindamycin (35.1%). Against H. influenzae, levofloxacin showed the most potent activity and its MIC90 was 0.063 μg/mL or less. Meropenem showed the most potent activity against P. aeruginosa (mucoid) and its MIC90 was 1 μg/mL. Against the non-mucoid type of P. aeruginosa, tobramycin had the most potent activity and its MIC90 was 2

  3. [Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibiotics (2006)].

    PubMed

    Goto, Hajime; Takeda, Hideki; Kawai, Shin; Suwabe, Akira; Watanabe, Suguru; Okazaki, Mitsuhiro; Ashino, Yugo; Shimada, Kaoru; Aoki, Nobuki; Sato, Tetsuo; Honma, Yasuo; Mori, Takeshi; Kudo, Kouichiro; Sugiyama, Haruhito; Kondo, Shigemi; Tanaka, Tsukasa; Kido, Kenji; Yoshimura, Kunihiko; Oguri, Toyoko; Yamamoto, Makoto; Nakamori, Yoshitaka; Inoue, Hiroshi; Yamauchi, Kohei; Sumitomo, Midori; Endo, Shigeatsu; Nakadate, Toshihide; Oka, Mikio; Kobashi, Yoshihiro; Saita, Naoki; Yanagihara, Katsunori; Kondou, Akira; Matsuda, Junichi; Nakano, Michiko; Kohno, Shigeru; Oikawa, Satoru

    2013-12-01

    From October 2006 to September 2007, we collected the specimen from 356 patients with lower respiratory tract infections in 14 institutions in Japan, and investigated the susceptibilities of isolated bacteria to various antibacterial agents and patients' characteristics. Of 414 strains that were isolated from specimen (mainly from sputum) and assumed to be bacteria causing in infection, 407 strains were examined. The isolated bacteria were: Staphylococcus aureus 64, Streptococcus pneumoniae 96, Haemophilus influenzae 87, Pseudomonas aeruginosa (non-mucoid) 52, P. aeruginosa (mucoid) 11, Klebsiella pneumoniae 20, and Moraxella catarrhalis 44. Of 64 S. aureus strains, those with 2 microg/ml or less of MIC of oxacillin (methicillin-susceptible S. aureus: MSSA) and those with 4 microg/ml or more of MIC of oxacillin (methicillin-resistant S. aureus: MRSA) were 27 (42.2%) and 37 (57.8%) strains, respectively. Against MSSA, imipenem had the most potent antibacterial activity and inhibited the growth of all strains at 0.063 microg/ml or less. Against MRSA, vancomycin and linezolid showed the most potent activity and inhibited the growth of all the strains at 1 microg/ml. Carbapenems showed the most potent activities against S. pneumoniae and in particular, panipenem inhibited the growth of all the strains at 0.063 microg/ml or less. Imipenem and faropenem also had a preferable activity and inhibited the growth of all the strains at 0.125 and 0.5 microg/ml, respectively. In contrast, there were high-resistant strains (MIC: over 128 microg/ml) for erythromycin (45.8%) and clindamycin (20.8%). Against H. influenzae, levofloxacin showed the most potent activity and its MIC90 was 0.063 microg/ml or less. Meropenem showed the most potent activity against P. aeruginosa (mucoid) and its MIC90 was 0.5 microg/ml. Against P. aeruginosa (non-mucoid), tobramycin had the most potent activity and its MIC90 was 2 microg/ml. Against K. pneumoniae, cefozopran was the most potent activity

  4. [Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibacterial agents (2008)].

    PubMed

    Goto, Hajime; Iwasaki, Mitsuhiro

    2015-02-01

    From October 2008 to September 2009, we collected the specimen from 374 patients with lower respiratory tract infections in 15 institutions in Japan, and investigated the susceptibilities of isolated bacteria to various antibacterial agents and patients' characteristics. Of 423 strains that were isolated from specimen (mainly from sputum) and assumed to be bacteria causing in infection, 421 strains were examined. The isolated bacteria were: Staphylococcus aureus 78, Streptococcus pneumoniae 78, Haemophilus influenzae 89, Pseudomonas aeruginosa (non-mucoid) 61, P. aeruginosa (mucoid) 19, Klebsiella pneumoniae 28, and Moraxella catarrhalis 32. Of 78 S. aureus strains, those with 2 μg/mL or less of MIC of oxacillin (methicillin-susceptible S. aureus: MSSA) and those with 4 μg/mL or more of MIC of oxacillin (methicillin-resistant S. aureus: MRSA) were 34 (43.6%) and 44 (56.4%) strains, respectively. Against MSSA, imipenem had the most potent antibacterial activity and inhibited the growth of all strains at 0.063 μg/mL or less. Against MRSA vancomycin and arbekacin showed the potent activity and inhibited the growth of all the strains at 1 and 2 μg/mL, respectively. Linezolid also showed the great activity and inhibited the growth of all the strains at 1 μg/mL. Carbapenems and penems showed the most potent activities against S. pneumoniae and panipenem inhibited the growth of all the strains at 0.125 μg/mL. Imipenem and faropenem also had a preferable activity and inhibited the growth of all the strains at 0.25 and 1 μg/mL, respectively. In contrast, there were high-resistant strains (MIC: > 128 μg/mL) for erythromycin (43.6%) and clindamycin (19.2%). Against H. influenzae, levofloxacin showed the most potent activity and its MIC90 was 0.063 μg/mL or less. Tobramycin showed the most potent activity against P. aeruginosa (mucoid) and its MIC90 was 2 μg/mL. Against the non-mucoid type of P. aeruginosa, tobramycin and ciprofloxacin had the most potent activity

  5. [Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibacterial agents (2007)].

    PubMed

    Goto, Hajime; Iwasaki, Mitsuhiro

    2015-02-01

    From October 2007 to September 2008, we collected the specimen from 362 patients with lower respiratory tract infections in 14 institutions in Japan, and investigated the susceptibilities of isolated bacteria to various antibacterial agents and patients' characteristics. Of 413 strains that were isolated from specimen (mainly from sputum) and assumed to be bacteria causing in infection, 412 strains were examined. The isolated bacteria were: Staphylococcus aureus 65, Streptococcus pneumoniae 90, Haemophilus influenzae 88, Pseudomonas aeruginosa (non-mucoid) 53, P. aeruginosa (mucoid) 13, Klebsiella pneumoniae 19, and Moraxella catarrhalis 41. Of 65 S. aureus strains, those with 2 μg/mL or less of MIC of oxacillin (methicillin-susceptible S. aureus: MSSA) and those with 4 μg/mL or more of MIC of oxacillin (methicillin-resistant S. aureus: MRSA) were 38 (58.5%) and 27 (41.5%) strains, respectively. Against MSSA, imipenem had the most potent antibacterial activity and inhibited the growth of all strains at 0.063 μg/mL or less. Against MRSA, vancomycin and arbekacin showed the most potent activity and inhibited the growth of all the strains at 2 μg/mL. Linezolid also showed the same activity as them. Carbapenems and penems showed the most potent activities against S. pneumoniae and in particular, panipenem inhibited the growth of all the strains at 0.063 μg/mL or less. Imipenem and faropenem also had a preferable activity and inhibited the growth of all the strains at 0.25 and 1 μg/mL, respectively. In contrast, there were high-resistant strains (MIC: over 128 μg/mL) for erythromycin (38.2%) and clindamycin (18.0%). Against H. influenzae, levofloxacin showed the most potent activity and its MIC90 was 0.063 μg/mL or less. Meropenem showed the most potent activity against P. aeruginosa (mucoid) and its MIC90 was 0.5 μg/mL. Against P. aeruginosa (non-mucoid), tobramycin had the most potent activity and its MIC90 was 2 μg/mL. Against K. pneumoniae, cefozopran had

  6. [Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibiotics (2005)].

    PubMed

    Goto, Hajime; Takeda, Hideki; Kawai, Shin; Watanabe, Suguru; Okazaki, Mitsuhiro; Shimada, Kaoru; Nakano, Kunio; Yokouchi, Hiroshi; Mori, Takeshi; Igari, Jun; Oguri, Toyoko; Yamamoto, Makoto; Kudo, Kolichiro; Kobayashi, Nobuyuki; Tanaka, Tsukasa; Yoshimura, Kunihiko; Kawabata, Masaaki; Nakamori, Yoshitaka; Sumitomo, Midori; Inoue, Hiroshi; Nakadate, Toshihide; Suwabe, Akira; Ashino, Yugo; Aoki, Nobuki; Honma, Yasuo; Suzuki, Yasutoshi; Karasawa, Yasuo; Oka, Mikio; Kobashi, Yoshihiro; Kohno, Shigeru; Hirakata, Yoichi; Kondou, Akira; Matsuda, Junichi; Nakano, Michiko; Oikawa, Satoru

    2008-08-01

    From October 2005 to September 2006, we collected the specimen from 366 patients with lower respiratory tract infections in 12 institutions in Japan, and investigated the susceptibilities of isolated bacteria to various antibacterial agents and patients' characteristics. Of 411 strains that were isolated from specimen (mainly from sputum) and assumed to be bacteria causing in infection, 406 strains were examined. The isolated bacteria were: Staphylococcus aureus 70, Streptococcus pneumoniae 85, Haemophilus influenzae 78, Pseudomonas aeruginosa (non-mucoid) 46, P. aeruginosa (mucoid) 14, Klebsiella pneumoniae 21, and Moraxella subgenus Branhamella catarrhalis 40. Of 70 S. aureus strains, those with 2 microg/ml or less of MIC of oxacillin (methicillin-susceptible S. aureus: MSSA) and those with 4 microg/ml or more of MIC of oxacillin (methicillin-resistant S. aureus: MRSA) were 38 (54.3%) and 32 (45.7%) strains, respectively. Against MSSA, imipenem had the most potent antibacterial activity and inhibited the growth of 37 strains (97.4%) at 0.063 microg/ml or less. Against MRSA, arbekacin and vancomycin showed the most potent activity and inhibited the growth of all the strains at 1 microg/ml. Carbapenems showed the most potent activities against S. pneumoniae and in particular, panipenem inhibited the growth of all the strains at 0.063 microg/ml or less. Faropenem also had a preferable activity and inhibited the growth of all the strains at 0.25 microg/ml. In contrast, there were high-resistant strains (MIC: over 128 microg/ml) for erythromycin (38.1%) and clindamycin (22.6%). Against H. influenzae, levofloxacin showed the most potent activity and its MIC90 was 0.063 microg/ml or less. Meropenem showed the most potent activity against P. aeruginosa (mucoid) and its MIC90 was 0.5 microg/ml. Against P. aeruginosa (non-mucoid), arbekacin had the most potent activity and its MIC90 was 8 microg/ml. Against K. pneumoniae, cefozopran was the most potent activity and

  7. Isolation and screening of polyhydroxyalkanoates producing bacteria from pulp, paper, and cardboard industry wastes.

    PubMed

    Bhuwal, Anish Kumari; Singh, Gulab; Aggarwal, Neeraj Kumar; Goyal, Varsha; Yadav, Anita

    2013-01-01

    Background. Polyhydroxyalkanoates (PHAs) are storage materials that accumulate by various bacteria as energy and carbon reserve materials. They are biodegradable, environmentally friendly, and also biocompatible bioplastics. Unlike petrochemical-based plastics that take several decades to fully degrade, PHAs can be completely degraded within a year by variety of microorganisms into CO2 and water. In the present study, we aim to utilize pulp, paper, and cardboard industry sludge and waste water for the isolation and screening of polyhydroxyalkanoates (PHAs) accumulating bacteria and production of cost-effective PHB using cardboard industry waste water. Results. A total of 42 isolates showed black-blue coloration when stained with Sudan black B, a preliminary screening agent for lipophilic compounds, and a total of 15 isolates showed positive result with Nile blue A staining, a more specific dye for PHA granules. The isolates NAP11 and NAC1 showed maximum PHA production 79.27% and 77.63% with polymer concentration of 5.236 g/L and 4.042 g/L with cardboard industry waste water. Both of the selected isolates, NAP11 and NAC1, were classified up to genus level by studying their morphological and biochemical characteristics and were found to be Enterococcus sp., Brevundimonas sp. and, respectively. Conclusion. The isolates Enterococcus sp. NAP11 and Brevundimonas sp. NAC1 can be considered as good candidates for industrial production of PHB from cardboard industry waste water. We are reporting for the first time the use of cardboard industry waste water as a cultivation medium for the PHB production.

  8. Isolation and Screening of Polyhydroxyalkanoates Producing Bacteria from Pulp, Paper, and Cardboard Industry Wastes

    PubMed Central

    Bhuwal, Anish Kumari; Singh, Gulab; Aggarwal, Neeraj Kumar; Goyal, Varsha; Yadav, Anita

    2013-01-01

    Background. Polyhydroxyalkanoates (PHAs) are storage materials that accumulate by various bacteria as energy and carbon reserve materials. They are biodegradable, environmentally friendly, and also biocompatible bioplastics. Unlike petrochemical-based plastics that take several decades to fully degrade, PHAs can be completely degraded within a year by variety of microorganisms into CO2 and water. In the present study, we aim to utilize pulp, paper, and cardboard industry sludge and waste water for the isolation and screening of polyhydroxyalkanoates (PHAs) accumulating bacteria and production of cost-effective PHB using cardboard industry waste water. Results. A total of 42 isolates showed black-blue coloration when stained with Sudan black B, a preliminary screening agent for lipophilic compounds, and a total of 15 isolates showed positive result with Nile blue A staining, a more specific dye for PHA granules. The isolates NAP11 and NAC1 showed maximum PHA production 79.27% and 77.63% with polymer concentration of 5.236 g/L and 4.042 g/L with cardboard industry waste water. Both of the selected isolates, NAP11 and NAC1, were classified up to genus level by studying their morphological and biochemical characteristics and were found to be Enterococcus sp., Brevundimonas sp. and, respectively. Conclusion. The isolates Enterococcus sp. NAP11 and Brevundimonas sp. NAC1 can be considered as good candidates for industrial production of PHB from cardboard industry waste water. We are reporting for the first time the use of cardboard industry waste water as a cultivation medium for the PHB production. PMID:24288534

  9. Isolation and screening of polyhydroxyalkanoates producing bacteria from pulp, paper, and cardboard industry wastes.

    PubMed

    Bhuwal, Anish Kumari; Singh, Gulab; Aggarwal, Neeraj Kumar; Goyal, Varsha; Yadav, Anita

    2013-01-01

    Background. Polyhydroxyalkanoates (PHAs) are storage materials that accumulate by various bacteria as energy and carbon reserve materials. They are biodegradable, environmentally friendly, and also biocompatible bioplastics. Unlike petrochemical-based plastics that take several decades to fully degrade, PHAs can be completely degraded within a year by variety of microorganisms into CO2 and water. In the present study, we aim to utilize pulp, paper, and cardboard industry sludge and waste water for the isolation and screening of polyhydroxyalkanoates (PHAs) accumulating bacteria and production of cost-effective PHB using cardboard industry waste water. Results. A total of 42 isolates showed black-blue coloration when stained with Sudan black B, a preliminary screening agent for lipophilic compounds, and a total of 15 isolates showed positive result with Nile blue A staining, a more specific dye for PHA granules. The isolates NAP11 and NAC1 showed maximum PHA production 79.27% and 77.63% with polymer concentration of 5.236 g/L and 4.042 g/L with cardboard industry waste water. Both of the selected isolates, NAP11 and NAC1, were classified up to genus level by studying their morphological and biochemical characteristics and were found to be Enterococcus sp., Brevundimonas sp. and, respectively. Conclusion. The isolates Enterococcus sp. NAP11 and Brevundimonas sp. NAC1 can be considered as good candidates for industrial production of PHB from cardboard industry waste water. We are reporting for the first time the use of cardboard industry waste water as a cultivation medium for the PHB production. PMID:24288534

  10. Isolation and chemical characterization of lipid A from gram-negative bacteria.

    PubMed

    Henderson, Jeremy C; O'Brien, John P; Brodbelt, Jennifer S; Trent, M Stephen

    2013-09-16

    Lipopolysaccharide (LPS) is the major cell surface molecule of gram-negative bacteria, deposited on the outer leaflet of the outer membrane bilayer. LPS can be subdivided into three domains: the distal O-polysaccharide, a core oligosaccharide, and the lipid A domain consisting of a lipid A molecular species and 3-deoxy-D-manno-oct-2-ulosonic acid residues (Kdo). The lipid A domain is the only component essential for bacterial cell survival. Following its synthesis, lipid A is chemically modified in response to environmental stresses such as pH or temperature, to promote resistance to antibiotic compounds, and to evade recognition by mediators of the host innate immune response. The following protocol details the small- and large-scale isolation of lipid A from gram-negative bacteria. Isolated material is then chemically characterized by thin layer chromatography (TLC) or mass-spectrometry (MS). In addition to matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) MS, we also describe tandem MS protocols for analyzing lipid A molecular species using electrospray ionization (ESI) coupled to collision induced dissociation (CID) and newly employed ultraviolet photodissociation (UVPD) methods. Our MS protocols allow for unequivocal determination of chemical structure, paramount to characterization of lipid A molecules that contain unique or novel chemical modifications. We also describe the radioisotopic labeling, and subsequent isolation, of lipid A from bacterial cells for analysis by TLC. Relative to MS-based protocols, TLC provides a more economical and rapid characterization method, but cannot be used to unambiguously assign lipid A chemical structures without the use of standards of known chemical structure. Over the last two decades isolation and characterization of lipid A has led to numerous exciting discoveries that have improved our understanding of the physiology of gram-negative bacteria, mechanisms of antibiotic resistance, the human innate

  11. Phytobeneficial Properties of Bacteria Isolated from the Rhizosphere of Maize in Southwestern Nigerian Soils

    PubMed Central

    Odebode, A. C.; Hsu, S. F.

    2015-01-01

    Biocontrol agents isolated outside Africa have performed inconsistently under field conditions in Africa. The development of indigenous phytobeneficial microbial strains that suit local environments may help enhance competitiveness with in situ microorganisms and effectiveness at suppressing local pathogen strains. We isolated bacteria from the rhizosphere of maize growing in southwestern Nigeria and assessed them for growth-promoting characteristics. The best isolates were characterized using 16S rRNA genes and were further evaluated in the greenhouse on maize seedlings. Four isolates (EBS8, IGBR11, EPR2, and ADS14) were outstanding in in vitro assays of antagonistic activity against a local strain of Fusarium verticillioides, phosphate solubilization efficiency, chitinase enzyme activity, and indole-3-acetic acid production. Inoculation of maize seeds with these isolates resulted in ≥95% maize seed germination and significantly enhanced radicle and plumule length. In the greenhouse, maize seedling height, stem girth, number of leaves, leaf area, shoot mass (dry matter), and nutrient contents were significantly enhanced. The bioprotectant and phytobeneficial effects were strongest and most consistent for isolate EBS8, which was identified as a Bacillus strain by 16S rRNA gene analysis. As a bacterial strain that exhibits multiple growth-promoting characteristics and is adapted to local conditions, EBS8 should be considered for the development of indigenous biological fertilizer treatments. PMID:25956774

  12. Isolation and enzyme bioprospection of endophytic bacteria associated with plants of Brazilian mangrove ecosystem.

    PubMed

    Castro, Renata A; Quecine, Maria Carolina; Lacava, Paulo T; Batista, Bruna D; Luvizotto, Danice M; Marcon, Joelma; Ferreira, Anderson; Melo, Itamar S; Azevedo, João L

    2014-01-01

    The mangrove ecosystem is a coastal tropical biome located in the transition zone between land and sea that is characterized by periodic flooding, which confers unique and specific environmental conditions on this biome. In these ecosystems, the vegetation is dominated by a particular group of plant species that provide a unique environment harboring diverse groups of microorganisms, including the endophytic microorganisms that are the focus of this study. Because of their intimate association with plants, endophytic microorganisms could be explored for biotechnologically significant products, such as enzymes, proteins, antibiotics and others. Here, we isolated endophytic microorganisms from two mangrove species, Rhizophora mangle and Avicennia nitida, that are found in streams in two mangrove systems in Bertioga and Cananéia, Brazil. Bacillus was the most frequently isolated genus, comprising 42% of the species isolated from Cananéia and 28% of the species from Bertioga. However, other common endophytic genera such as Pantoea, Curtobacterium and Enterobacter were also found. After identifying the isolates, the bacterial communities were evaluated for enzyme production. Protease activity was observed in 75% of the isolates, while endoglucanase activity occurred in 62% of the isolates. Bacillus showed the highest activity rates for amylase and esterase and endoglucanase. To our knowledge, this is the first reported diversity analysis performed on endophytic bacteria obtained from the branches of mangrove trees and the first overview of the specific enzymes produced by different bacterial genera. This work contributes to our knowledge of the microorganisms and enzymes present in mangrove ecosystems. PMID:25110630

  13. Phytobeneficial Properties of Bacteria Isolated from the Rhizosphere of Maize in Southwestern Nigerian Soils.

    PubMed

    Abiala, M A; Odebode, A C; Hsu, S F; Blackwood, C B

    2015-07-01

    Biocontrol agents isolated outside Africa have performed inconsistently under field conditions in Africa. The development of indigenous phytobeneficial microbial strains that suit local environments may help enhance competitiveness with in situ microorganisms and effectiveness at suppressing local pathogen strains. We isolated bacteria from the rhizosphere of maize growing in southwestern Nigeria and assessed them for growth-promoting characteristics. The best isolates were characterized using 16S rRNA genes and were further evaluated in the greenhouse on maize seedlings. Four isolates (EBS8, IGBR11, EPR2, and ADS14) were outstanding in in vitro assays of antagonistic activity against a local strain of Fusarium verticillioides, phosphate solubilization efficiency, chitinase enzyme activity, and indole-3-acetic acid production. Inoculation of maize seeds with these isolates resulted in ≥95% maize seed germination and significantly enhanced radicle and plumule length. In the greenhouse, maize seedling height, stem girth, number of leaves, leaf area, shoot mass (dry matter), and nutrient contents were significantly enhanced. The bioprotectant and phytobeneficial effects were strongest and most consistent for isolate EBS8, which was identified as a Bacillus strain by 16S rRNA gene analysis. As a bacterial strain that exhibits multiple growth-promoting characteristics and is adapted to local conditions, EBS8 should be considered for the development of indigenous biological fertilizer treatments. PMID:25956774

  14. In vitro antibacterial potency of Butea monosperma Lam. against 12 clinically isolated multidrug resistant bacteria

    PubMed Central

    Sahu, Mahesh Chandra; Padhy, Rabindra Nath

    2013-01-01

    Objective To investigate the antibacterial activity, using cold and hot extraction procedures with five solvents, petroleum ether, acetone, ethanol, methanol and water to validate medicinal uses of Butea monosperma Lam (B. monosperma) in controlling infections; and to qualitatively estimate phytochemical constituents of leaf-extracts of the plant. Methods The antibacterial activity of leaf-extracts was evaluated by the agar-well diffusion method against clinically isolated 12 Gram-positive and -negative multidrug resistant (MDR) pathogenic bacteria in vitro. Values of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of leaf-extracts against each bacterium were obtained in a 96-well micro-titre plate, by broth dilution micro-titre plate technique. Results The presence of tannins, flavonoids, starch, glycosides and carbohydrates in different leaf extracts was established. Pathogenic bacteria used were, Acinetobacter sp., Chromobacterium violaceum, Citrobacter freundii, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, Shigella sp., Enterococcus sp., Staphylococcus aureus (S. aureus), methicillin resistant S. aureus and vancomycin resistant S. aureus, along with standard bacterial strains. These MDR bacteria had been recorded to have significant inhibitions by leaf extracts, obtained by cold and hot extraction procedures with five solvents. In addition, the hot aqueous extract against Enterococcus sp. had the highest inhibition zone-size (21 mm). Ciprofloxacin 30 µg/disc was the positive/reference control and the diluting solvent, 10% dimethyl sulphoxide was the negative control. Recorded MIC values of different extracts ranged between 0.23 and 13.30 mg/mL, and MBC values were 0.52 to 30.00 mg/mL, for these bacteria. Conclusions Leaf-extracts with hot water and ethanol had shown significant antibacterial activity against all bacteria. B. monosperma leaf-extract could be used in treating infectious

  15. Intestinal microflora in rats: isolation and characterization of strictly anaerobic bacteria requiring long-chain fatty acids.

    PubMed Central

    Morotomi, M; Kawai, Y; Mutai, M

    1976-01-01

    Three strains of strictly anaerobic bacteria, isolated from the cecal contents of rats, have strict requirements for long-chain fatty acids. The effect of exogenous fatty acids on the growth and fatty acid composition of the bacteria was examined. Biohydrogenation of linoleic acid into octadecenoic acid was observed. These observations suggest that long-chain fatty acids in the intestine are factors in controlling the localization and the population levels of indigenous bacteria in vivo in rats. PMID:1267446

  16. Isolation of some pathogenic bacteria from the great spruce bark beetle, Dendroctonus micans and its specific predator, Rhizophagus grandis.

    PubMed

    Yaman, M; Ertürk, O; Aslan, I

    2010-01-01

    Some bacteria were isolated from Dendroctonus micans and its specific predator, Rhizophagus grandis. Six bacteria from D. micans were identified as Bacillus pumilus, Enterobacter intermedius, Citrobacter freundii, Cellulomonas flavigena, Microbacterium liquefaciens and Enterobacter amnigenus, three bacteria from R. grandis as Klebsiella pneumoniae, Pantoea agglomerans and Serratia grimesii, on the basis of fatty acid methyl ester analysis and carbon utilization profile by using Microbial Identification and Biolog Microplate Systems. Their insecticidal effects were tested on larvae and adults of D. micans.

  17. Recurrent isolation of extremotolerant bacteria from the clean room where Phoenix spacecraft components were assembled.

    PubMed

    Ghosh, Sudeshna; Osman, Shariff; Vaishampayan, Parag; Venkateswaran, Kasthuri

    2010-04-01

    The microbial burden of the Phoenix spacecraft assembly environment was assessed in a systematic manner via several cultivation-based techniques and a suite of NASA-certified, cultivation-independent biomolecule-based detection assays. Extremotolerant bacteria that could potentially survive conditions experienced en route to Mars or on the planet's surface were isolated with a series of cultivation-based assays that promoted the growth of a variety of organisms, including spore formers, mesophilic heterotrophs, anaerobes, thermophiles, psychrophiles, alkaliphiles, and bacteria resistant to UVC radiation and hydrogen peroxide exposure. Samples were collected from the clean room where Phoenix was housed at three different time points, before (1P), during (2P), and after (3P) Phoenix's presence at the facility. There was a reduction in microbial burden of most bacterial groups, including spore formers, in samples 2P and 3P. Analysis of 262 isolates from the facility demonstrated that there was also a shift in predominant cultivable bacterial populations accompanied by a reduction in diversity during 2P and 3P. It is suggested that this shift was a result of increased cleaning when Phoenix was present in the assembly facility and that certain species, such as Acinetobacter johnsonii and Brevundimonas diminuta, may be better adapted to environmental conditions found during 2P and 3P. In addition, problematic bacteria resistant to multiple extreme conditions, such as Bacillus pumilus, were able to survive these periods of increased cleaning.

  18. Isolation, characterization and evaluation of probiotic lactic acid bacteria for potential use in animal production.

    PubMed

    García-Hernández, Yaneisy; Pérez-Sánchez, Tania; Boucourt, Ramón; Balcázar, José L; Nicoli, Jacques R; Moreira-Silva, João; Rodríguez, Zoraya; Fuertes, Héctor; Nuñez, Odalys; Albelo, Nereyda; Halaihel, Nabil

    2016-10-01

    In livestock production, lactic acid bacteria (LAB) are the most common microorganisms used as probiotics. For such use, these bacteria must be correctly identified and characterized to ensure their safety and efficiency. In the present study, LAB were isolated from broiler excreta, where a fermentation process was used. Nine among sixteen isolates were identified by biochemical and molecular (sequencing of the 16S rRNA gene) methods as Lactobacillus crispatus (n=1), Lactobacillus pentosus (n=1), Weissella cibaria (n=1), Pediococcus pentosaceus (n=2) and Enterococcus hirae (n=4). Subsequently, these bacteria were characterized for their growth capabilities, lactic acid production, acidic pH and bile salts tolerance, cell surface hydrophobicity, antimicrobial susceptibility and antagonistic activity. Lactobacillus pentosus strain LB-31, which showed the best characteristics, was selected for further analysis. This strain was administered to broilers and showed the ability of modulating the immune response and producing beneficial effects on morpho-physiological, productive and health indicators of the animals. PMID:27663381

  19. Isolation and characterization of gasoline-degrading bacteria from gas station leaking-contaminated soils.

    PubMed

    Lu, Si-Jin; Wang, Hong-qi; Yao, Zhi-hua

    2006-01-01

    The effects of culture conditions in vitro and biosurfactant detection were studied on bacterial strains capable of degrading gasoline from contaminated soils near gas station. The main results were summarized as follows. Three bacteria (strains Q 10, Q14 and Q18) that were considered as efficiently degrading strains were isolated and identified as Pseudomonas sp., Flavobacterium sp. and Rhodococcus sp., respectively. The optimal growth conditions of three bacteria including pH, temperature and the concentration of gasoline were similar. The reduction in surface tension was observed with all the three bacteria, indicating the production of biosurfactant compounds. The value of surface tension reduced by the three strains Q10, Q14 and Q18 was 32.6 mN x m, 12.4 mNx m and 21.9 mN x m, respectively. Strain Q10 could be considered as a potential biosurfactant producer. Gasoline, diesel oil, benzene, toluene, ethylbenzene and xylene (BTEX) could easily be degraded by the three isolates. The consortium was more effective than the individual cultures in degrading added gasoline, diesel oil, and BTEX. These results indicate that these strains have great potential for in situ remediation of soils contaminated by gas station leaking.

  20. luxS in bacteria isolated from 25- to 40-million-year-old amber.

    PubMed

    Santiago-Rodriguez, Tasha M; Patrício, Ana R; Rivera, Jessica I; Coradin, Mariel; Gonzalez, Alfredo; Tirado, Gabriela; Cano, Raúl J; Toranzos, Gary A

    2014-01-01

    Interspecies bacterial communication is mediated by autoinducer-2, whose synthesis depends on luxS. Due to the apparent universality of luxS (present in more than 40 bacterial species), it may have an ancient origin; however, no direct evidence is currently available. We amplified luxS in bacteria isolated from 25- to 40-million-year-old amber. The phylogenies and molecular clocks of luxS and the 16S rRNA gene from ancient and extant bacteria were determined as well. Luminescence assays using Vibrio harveyi BB170 aimed to determine the activity of luxS. While the phylogeny of luxS was very similar to that of extant Bacillus spp., amber isolates exhibited unique 16S rRNA gene phylogenies. This suggests that luxS may have been acquired by horizontal transfer millions of years ago. Molecular clocks of luxS suggest slow evolutionary rates, similar to those of the 16S rRNA gene and consistent with a conserved gene. Dendograms of the 16S rRNA gene and luxS show two separate clusters for the extant and ancient bacteria, confirming the uniqueness of the latter group.

  1. Growth Potential of Halophilic Bacteria Isolated from Solar Salt Environments: Carbon Sources and Salt Requirements

    PubMed Central

    Javor, Barbara J.

    1984-01-01

    Eighteen strains of extremely halophilic bacteria and three strains of moderately halophilic bacteria were isolated from four different solar salt environments. Growth tests on carbohydrates, low-molecular-weight carboxylic acids, and complex medium demonstrated that the moderate halophiles and strains of the extreme halophiles Haloarcula and Halococcus grew on most of the substrates tested. Among the Halobacterium isolates were several metabolic groups: strains that grew on a broad range of substrates and strains that were essentially confined to either amino acid (peptone) or carbohydrate oxidation. One strain (WS-4) only grew well on pyruvate and acetate. Most strains of extreme halophiles grew by anaerobic fermentation and possibly by nitrate reduction. Tests of growth potential in natural saltern brines demonstrated that none of the halobacteria grew well in brines which harbor the densest populations of these bacteria in solar salterns. All grew best in brines which were unsaturated with NaCl. The high concentrations of Na+ and Mg2+ found in saltern crystallizer brines limited bacterial growth, but the concentrations of K+ found in these brines had little effect. MgSO4 was relatively more inhibitory to the extreme halophiles than was MgCl2, but the reverse was true for the moderate halophiles. PMID:16346609

  2. Isolation of Sphaerotilus-Leptothrix strains from iron bacteria communities in Tierra del Fuego wetlands.

    PubMed

    Schmidt, Bertram; Sánchez, Leandro A; Fretschner, Till; Kreps, Gastón; Ferrero, Marcela A; Siñeriz, Faustino; Szewzyk, Ulrich

    2014-11-01

    Sheath-forming iron- and manganese-depositing bacteria belonging to the Sphaerotilus-Leptothrix group (SLG) are widespread in natural and artificial water systems. Known requirements for their growth include the presence of organic substrates and molecular oxygen. High concentrations of reduced iron or manganese, although not necessary for most species, make their growth a noticeable phenomenon. Such microbial communities have been studied mostly in the Northern Hemisphere. Here, we present descriptions of diverse ochre-depositing microbial communities in Tierra del Fuego, Argentina, using a combined approach of microscopical examination, clone library construction and cultivation focused on SLG bacteria. To date, only few SLG type strains are available. The present work increases the number and diversity of cultivated SLG bacteria by obtaining isolates from biofilms and sediment samples of wetlands in Tierra del Fuego. Thirty isolates were selected based on morphological features such as sheath formation and iron/manganese deposition. Five operational taxonomic units (OTUs) were deduced. Sequencing of 16S rRNA genes showed that one OTU is identical to the Leptothrix mobilis Feox-1(T) -sequence while the four remaining OTUs show similarity values related to previously described type strains. Similarity values ranged from 96.5% to 98.8%, indicating possible new species and subspecies. PMID:25098830

  3. Isolation of Sphaerotilus-Leptothrix strains from iron bacteria communities in Tierra del Fuego wetlands.

    PubMed

    Schmidt, Bertram; Sánchez, Leandro A; Fretschner, Till; Kreps, Gastón; Ferrero, Marcela A; Siñeriz, Faustino; Szewzyk, Ulrich

    2014-11-01

    Sheath-forming iron- and manganese-depositing bacteria belonging to the Sphaerotilus-Leptothrix group (SLG) are widespread in natural and artificial water systems. Known requirements for their growth include the presence of organic substrates and molecular oxygen. High concentrations of reduced iron or manganese, although not necessary for most species, make their growth a noticeable phenomenon. Such microbial communities have been studied mostly in the Northern Hemisphere. Here, we present descriptions of diverse ochre-depositing microbial communities in Tierra del Fuego, Argentina, using a combined approach of microscopical examination, clone library construction and cultivation focused on SLG bacteria. To date, only few SLG type strains are available. The present work increases the number and diversity of cultivated SLG bacteria by obtaining isolates from biofilms and sediment samples of wetlands in Tierra del Fuego. Thirty isolates were selected based on morphological features such as sheath formation and iron/manganese deposition. Five operational taxonomic units (OTUs) were deduced. Sequencing of 16S rRNA genes showed that one OTU is identical to the Leptothrix mobilis Feox-1(T) -sequence while the four remaining OTUs show similarity values related to previously described type strains. Similarity values ranged from 96.5% to 98.8%, indicating possible new species and subspecies.

  4. Natural Antibiotic Resistance of Bacteria Isolated from Larvae of the Oil Fly, Helaeomyia petrolei

    PubMed Central

    Kadavy, Dana R.; Hornby, Jacob M.; Haverkost, Terry; Nickerson, Kenneth W.

    2000-01-01

    Helaeomyia petrolei (oil fly) larvae inhabit the asphalt seeps of Rancho La Brea in Los Angeles, Calif. The culturable microbial gut contents of larvae collected from the viscous oil were recently examined, and the majority (9 of 14) of the strains were identified as Providencia spp. Subsequently, 12 of the bacterial strains isolated were tested for their resistance or sensitivity to 23 commonly used antibiotics. All nine strains classified as Providencia rettgeri exhibited dramatic resistance to tetracycline, vancomycin, bacitracin, erythromycin, novobiocin, polymyxin, colistin, and nitrofurantoin. Eight of nine Providencia strains showed resistance to spectinomycin, six of nine showed resistance to chloramphenicol, and five of nine showed resistance to neomycin. All 12 isolates were sensitive to nalidixic acid, streptomycin, norfloxacin, aztreonam, cipericillin, pipericillin, and cefotaxime, and all but OF008 (Morganella morganii) were sensitive to ampicillin and cefoxitin. The oil fly bacteria were not resistant to multiple antibiotics due to an elevated mutation rate. For each bacterium, the number of resistant mutants per 108 cells was determined separately on rifampin, nalidixic acid, and spectinomycin. In each case, the average frequencies of resistant colonies were at least 50-fold lower than those established for known mutator strain ECOR 48. In addition, the oil fly bacteria do not appear to excrete antimicrobial agents. When tested, none of the oil fly bacteria produced detectable zones of inhibition on Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, or Candida albicans cultures. Furthermore, the resistance properties of oil fly bacteria extended to organic solvents as well as antibiotics. When pre-exposed to 20 μg of tetracycline per ml, seven of nine oil fly bacteria tolerated overlays of 100% cyclohexane, six of nine tolerated 10% xylene, benzene, or toluene (10:90 in cyclohexane), and three of nine (OF007, OF010, and OF011

  5. Isolation and Identification of Lactic Acid Bacteria Isolated from a Traditional Jeotgal Product in Korea

    NASA Astrophysics Data System (ADS)

    Cho, Gyu Sung; Do, Hyung Ki

    2006-06-01

    Seventeen lactic acid bacterial strains (LAB) were isolated using MRS agar medium from Jeotgal, a Korean fermented food, purchased at the Jukdo market of Pohang. To identify the strains isolated, they were tested by examining their cell morphologies, gram-staining, catalase activity, arginine hydrolase activity, D-L lactate form and carbohydrate fermentation. According to the phenotypic characteristics, three strains were tent atively identified as Lactobacillus spp., ten were Enterococcus spp. (or Streptococcus spp., or Pediococcus spp.) and the rest were Leuconostoc spp. (or Weissella spp.). Five strains among 17 were chosen by preliminary bacteriocin activity test. Four bacterial strains which inhibited both indicator microorganisms were identified by 16S rRNA sequencing. The results are as follows; Leuconostoc mesenteroides (HK 4), Leuconostoc mesenteroides (HK 5), Leuconostoc mesenteroides(HK 11), Streptococcus salivarius(HK 8). In order to check LAB which are showing a high survival rate in gut, we investigated three strains inhibiting both indicator microorganisms in artificial gastric acid and bile juice -all except HK8. The three strains mentioned above grew in extreme low acid conditions.

  6. Identification of effective Pb resistant bacteria isolated from Lens culinaris growing in lead contaminated soils.

    PubMed

    Jebara, Salwa Harzalli; Abdelkerim, Souhir; Fatnassi, Imen Challougui; Chiboub, Manel; Saadani, Omar; Jebara, Moez

    2015-03-01

    Soil bacteria are a new phytoremediation system for the removal of heavy metals from soils. In this study, fifteen soil bacteria were isolated from root nodules of lentil growing in heavy metals contaminated soils, particularly by lead. Molecular characterization of the collection showed a large diversity, including Agrobacterium tumefaciens, Rahnella aquatilis, Pseudomonas, and Rhizobium sp. These soil bacteria had a wide range of tolerance to heavy metals. Among them, strains of A. tumefaciens and R. aquatilis tolerated up to 3.35 mM Pb; whereas Pseudomonas tolerated up to 3.24 mM Pb. The inoculation of lentil grown hydroponically with inoculums formed by these efficient and Pb resistant bacteria enhanced plant biomass. The treatment of this symbiosis by 1 mM Pb for 10 days or by 2 mM Pb for 3 days demonstrated that lentil had Pb accumulation capacity and can be considered a Pb accumulator plant, elsewhere, roots accumulated more Pb than shoots, and the inoculation decreased the Pb up take by the plants, suggesting that this symbiosis should be investigated for use in phytostabilization of Pb-contaminated soils. At the same time, a modulation in the antioxidant enzyme activity and a specific duration was required for the induction of the superoxide dismutase (SOD), peroxidase (POX), and ascorbate peroxidase (APX) response and to adapt to Pb stress. These results suggested that these enzymes may be involved in the main mechanism of antioxidative defense in lentil exposed to Pb oxidative stress.

  7. Reduction of nitroaromatic compounds by anaerobic bacteria isolated from the human gastrointestinal tract.

    PubMed Central

    Rafil, F; Franklin, W; Heflich, R H; Cerniglia, C E

    1991-01-01

    Human intestinal microbial flora were screened for their abilities to reduce nitroaromatic compounds by growing them on brain heart infusion agar plates containing 1-nitropyrene. Bacteria metabolizing 1-nitropyrene, detected by the appearance of clear zones around the colonies, were identified as Clostridium leptum, Clostridium paraputrificum, Clostridium clostridiiforme, another Clostridium sp., and a Eubacterium sp. These bacteria produced aromatic amines from nitroaromatic compounds, as shown by thin-layer chromatography, high-pressure liquid chromatography, and biochemical tests. Incubation of three of these bacteria with 1-nitropyrene, 1,3-dinitropyrene, and 1,6-dinitropyrene inactivated the direct-acting mutagenicity associated with these compounds. Menadione and o-iodosobenzoic acid inhibited nitroreductase activity in all of the isolates, indicating the involvement of sulfhydryl groups in the active site of the enzyme. The optimum pH for nitroreductase activity was 8.0. Only the Clostridium sp. required added flavin adenine dinucleotide for nitroreductase activity. The nitroreductases were constitutive and extracellular. An activity stain for the detection of nitroreductase on anaerobic native polyacrylamide gels was developed. This activity stain revealed only one isozyme in each bacterium but showed that the nitroreductases from different bacteria had distinct electrophoretic mobilities. Images PMID:2059053

  8. Bacteria Isolated from Bats Inhibit the Growth of Pseudogymnoascus destructans, the Causative Agent of White-Nose Syndrome

    PubMed Central

    Hoyt, Joseph R.; Cheng, Tina L.; Langwig, Kate E.; Hee, Mallory M.; Frick, Winifred F.; Kilpatrick, A. Marm

    2015-01-01

    Emerging infectious diseases are a key threat to wildlife. Several fungal skin pathogens have recently emerged and caused widespread mortality in several vertebrate groups, including amphibians, bats, rattlesnakes and humans. White-nose syndrome, caused by the fungal skin pathogen Pseudogymnoascus destructans, threatens several hibernating bat species with extinction and there are few effective treatment strategies. The skin microbiome is increasingly understood to play a large role in determining disease outcome. We isolated bacteria from the skin of four bat species, and co-cultured these isolates with P. destructans to identify bacteria that might inhibit or kill P. destructans. We then conducted two reciprocal challenge experiments in vitro with six bacterial isolates (all in the genus Pseudomonas) to quantify the effect of these bacteria on the growth of P. destructans. All six Pseudomonas isolates significantly inhibited growth of P. destructans compared to non-inhibitory control bacteria, and two isolates performed significantly better than others in suppressing P. destructans growth for at least 35 days. In both challenge experiments, the extent of suppression of P. destructans growth was dependent on the initial concentration of P. destructans and the initial concentration of the bacterial isolate. These results show that bacteria found naturally occurring on bats can inhibit the growth of P. destructans in vitro and should be studied further as a possible probiotic to protect bats from white-nose syndrome. In addition, the presence of these bacteria may influence disease outcomes among individuals, populations, and species. PMID:25853558

  9. Bacteria isolated from bats inhibit the growth of Pseudogymnoascus destructans, the causative agent of white-nose syndrome.

    PubMed

    Hoyt, Joseph R; Cheng, Tina L; Langwig, Kate E; Hee, Mallory M; Frick, Winifred F; Kilpatrick, A Marm

    2015-01-01

    Emerging infectious diseases are a key threat to wildlife. Several fungal skin pathogens have recently emerged and caused widespread mortality in several vertebrate groups, including amphibians, bats, rattlesnakes and humans. White-nose syndrome, caused by the fungal skin pathogen Pseudogymnoascus destructans, threatens several hibernating bat species with extinction and there are few effective treatment strategies. The skin microbiome is increasingly understood to play a large role in determining disease outcome. We isolated bacteria from the skin of four bat species, and co-cultured these isolates with P. destructans to identify bacteria that might inhibit or kill P. destructans. We then conducted two reciprocal challenge experiments in vitro with six bacterial isolates (all in the genus Pseudomonas) to quantify the effect of these bacteria on the growth of P. destructans. All six Pseudomonas isolates significantly inhibited growth of P. destructans compared to non-inhibitory control bacteria, and two isolates performed significantly better than others in suppressing P. destructans growth for at least 35 days. In both challenge experiments, the extent of suppression of P. destructans growth was dependent on the initial concentration of P. destructans and the initial concentration of the bacterial isolate. These results show that bacteria found naturally occurring on bats can inhibit the growth of P. destructans in vitro and should be studied further as a possible probiotic to protect bats from white-nose syndrome. In addition, the presence of these bacteria may influence disease outcomes among individuals, populations, and species. PMID:25853558

  10. Supporting data for identification of biosurfactant-producing bacteria isolated from agro-food industrial effluent.

    PubMed

    Fulazzaky, Mohamad Ali; Abdullah, Shakila; Salim, Mohd Razman

    2016-06-01

    The goal of this study was to identify the biosurfactant-producing bacteria isolated from agro-food industrial effluet. The identification of the potential bacterial strain using a polymerase chain reaction of the 16S rRNA gene analysis was closely related to Serratia marcescens with its recorded strain of SA30 "Fundamentals of mass transfer and kinetics for biosorption of oil and grease from agro-food industrial effluent by Serratia marcescens SA30" (Fulazzaky et al., 2015) [1]; however, many biochemical tests have not been published yet. The biochemical tests of biosurfactant production, haemolytic assay and cell surface hydrophobicity were performed to investigate the beneficial strain of biosurfactant-producing bacteria. Here we do share data collected from the biochemical tests to get a better understanding of the use of Serratia marcescens SA30 to degrade oil, which contributes the technical features of strengthening the biological treatment of oil-contaminated wastewater in tropical environments.

  11. Supporting data for identification of biosurfactant-producing bacteria isolated from agro-food industrial effluent.

    PubMed

    Fulazzaky, Mohamad Ali; Abdullah, Shakila; Salim, Mohd Razman

    2016-06-01

    The goal of this study was to identify the biosurfactant-producing bacteria isolated from agro-food industrial effluet. The identification of the potential bacterial strain using a polymerase chain reaction of the 16S rRNA gene analysis was closely related to Serratia marcescens with its recorded strain of SA30 "Fundamentals of mass transfer and kinetics for biosorption of oil and grease from agro-food industrial effluent by Serratia marcescens SA30" (Fulazzaky et al., 2015) [1]; however, many biochemical tests have not been published yet. The biochemical tests of biosurfactant production, haemolytic assay and cell surface hydrophobicity were performed to investigate the beneficial strain of biosurfactant-producing bacteria. Here we do share data collected from the biochemical tests to get a better understanding of the use of Serratia marcescens SA30 to degrade oil, which contributes the technical features of strengthening the biological treatment of oil-contaminated wastewater in tropical environments. PMID:27077083

  12. Characterization of boron tolerant bacteria isolated from a fly ash dumping site for bacterial boron remediation.

    PubMed

    Edward Raja, Chellaiah; Omine, Kiyoshi

    2013-08-01

    Boron is an essential micronutrient for plants, but can above certain concentrations be toxic to living organisms. A major environmental concern is the removal of boron from contaminated water and fly ash. For this purpose, the samples were collected from a fly ash dumping site, Nagasaki prefecture, Japan. The chemical characteristics and heavy metal concentration of the samples were performed by X-ray fluorescent analysis and leaching test. For bacterial analysis, samples were collected in sterile plastic sheets and isolation was carried out by serial dilution method. The boron tolerant isolates that showed values of maximum inhibitory concentration toward boron ranging from 100 to 260 mM level were screened. Based on 16S rRNA sequencing and phylogenetic analysis, the isolates were most closely related to the genera Bacillus, Lysinibacillus, Microbacterium and Ralstonia. The boron tolerance of these strains was also associated with resistant to several heavy metals, such as As (III), Cr (VI), Cd, Cu, Pb, Ni, Se (III) and Zn. Indeed, these strains were arsenic oxidizing bacteria confirmed by silver nitrate test. These strains exhibited their salt resistances ranging from 4 to 15 % were determined in Trypticase soy agar medium. The boron tolerant strains were capable of removing 0.1-2.0 and 2.7-3.7 mg l(-1) boron from the medium and fly ash at 168 h. Thus, we have successfully identified the boron tolerant and removal bacteria from a fly ash dumping site for boron remediation.

  13. Taxonomic status and ecologic function of methanogenic bacteria isolated from the oral cavity of humans

    SciTech Connect

    Kemp, C.W.

    1985-01-01

    The detection of methane gas in samples of dental plaque and media inoculated with dental plaque was attributed to the presence of methane-producing bacteria in the plaque microbiota. The results of a taxonomic analysis of the 12 methanogenic isolates obtained from human dental plaque, (ABK1-ABK12), placed the organisms in the genus Methanobrevibacter. A DNA-DNA hybridization survey established three distinct genetic groups of oral methanogens based on percent homology values. The groups exhibited less than 32% homology between themselves and less than 17% homology with the three known members of the genus methanobrevibacter. The ecological role of the oral methanogens was established using mixed cultures of selected methanogenic isolates (ABK1, ABK4, ABK6, or ABK7) with oral heterotrophic bacteria. Binary cultures of either Streptococcus mutans, Streptococcus sanguis, Veillonella rodentium, Lactobacillus casei, or Peptostreptococcus anaerobius together with either methanogenic isolates ABK6 or ABK7 were grown to determine the effect of the methanogens on the distribution of carbon end products produced by the heterotrophs. Binary cultures of S. mutans and ABK7 exhibited a 27% decrease in lactic acid formation when compared to pure culture of S. mutans. The decrease in lactic acid production was attributed to the removal of formate by the methanogen, (ABK7), which caused an alteration in the distribution of carbon end products by S. mutans.

  14. Methanogenesis in hypersaline ecosystems, and isolation and characterization of eight halophilic, methanogenic bacteria

    SciTech Connect

    Mathrani, I.M.

    1989-01-01

    The present ecological study of methanogenesis in hypersaline ecosystems focused on anaerobic sediment samples collected from several parts of the world. Inocula from solar salterns and natural hypersaline systems were examined for their ability to use catabolic substrates and for conditions which supported methanogenesis. Eight strictly anaerobic, halophilic, methane-producing Archaeobacteria were isolated from enrichment cultures inoculated with samples from hypersaline systems. The physiological and ecological characteristics of the isolates were examined and their phenotypic relatedness to each other and existing species of halophilic methanogens was discussed. The methanogenic, sulfate-reducing, and cellulolytic, halophilic bacteria from sediments of Lake Retba, Senegal were enumerated in depth profiles of sediment core samples. The catabolic substrates and environmental conditions for best growth of each bacterial group were determined. Trimethylamine, dimethylamine, methylamine, methanol, and sometimes dimethylsulfide were used as substrates for growth of methanogenic enrichment cultures and the eight isolates; hydrogen, acetate, or secondary alcohols did not support growth of methanogens. Hydrogen, formate, and lactate supported the growth of halophilic sulfate-reducing bacteria.

  15. Isolation of Lactic Acid Bacteria Showing Antioxidative and Probiotic Activities from Kimchi and Infant Feces.

    PubMed

    Ji, Keunho; Jang, Na Young; Kim, Young Tae

    2015-09-01

    The purpose of this study was to investigate lactic acid bacteria with antioxidative and probiotic activities isolated from Korean healthy infant feces and kimchi. Isolates A1, A2, S1, S2, and S3 were assigned to Lactobacillus sp. and isolates A3, A4, E1, E2, E3, and E4 were assigned to Leuconostoc sp. on the basis of their physiological properties and 16S ribosomal DNA sequence analysis. Most strains were confirmed as safe bioresources through nonhemolytic activities and non-production of harmful enzymes such as β-glucosidase, β- glucuronidase and tryptophanase. The 11 isolates showed different resistance to acid and bile acids. In addition, they exhibited antibacterial activity against foodborne bacteria, especially Bacillus cereus, Listeria monocytogenes, and Escherichia coli. Furthermore, all strains showed significantly high levels of hydrophobicity. The antioxidant effects of culture filtrates of the 11 strains included 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging capacity, 2.2'- azino-bis (2-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical cation scavenging activity, and superoxide dismutase activity. The results revealed that most of the culture filtrates have effective scavenging activity for DPPH and ABTS radicals. All strains appeared to have effective superoxide dismutase activity. In conclusion, the isolated strains A1, A3, S1, and S3 have significant probiotic activities applicable to the development of functional foods and health-related products. These strains might also contribute to preventing and controlling several diseases associated with oxidative stress, when used as probiotics.

  16. Airborne multidrug-resistant bacteria isolated from a concentrated swine feeding operation.

    PubMed

    Chapin, Amy; Rule, Ana; Gibson, Kristen; Buckley, Timothy; Schwab, Kellogg

    2005-02-01

    The use of nontherapeutic levels of antibiotics in swine production can select for antibiotic resistance in commensal and pathogenic bacteria in swine. As a result, retail pork products, as well as surface and groundwaters contaminated with swine waste, have been shown to be sources of human exposure to antibiotic-resistant bacteria. However, it is unclear whether the air within swine operations also serves as a source of exposure to antibiotic-resistant bacterial pathogens. To investigate this issue, we sampled the air within a concentrated swine feeding operation with an all-glass impinger. Samples were analyzed using a method for the isolation of Enterococcus. A total of 137 presumptive Enterococcus isolates were identified to species level using standard biochemical tests and analyzed for resistance to erythromycin, clindamycin, virginiamycin, tetracycline, and vancomycin using the agar dilution method. Thirty-four percent of the isolates were confirmed as Enterococcus, 32% were identified as coagulase-negative staphylococci, and 33% were identified as viridans group streptococci. Regardless of bacterial species, 98% of the isolates expressed high-level resistance to at least two antibiotics commonly used in swine production. None of the isolates were resistant to vancomycin, an antibiotic that has never been approved for use in livestock in the United States. In conclusion, high-level multidrug-resistant Enterococcus, coagulase-negative staphylococci, and viridans group streptococci were detected in the air of a concentrated swine feeding operation. These findings suggest that the inhalation of air from these facilities may serve as an exposure pathway for the transfer of multidrug-resistant bacterial pathogens from swine to humans.

  17. Deep subsurface life from North Pond: Enrichment, isolation, characterization and genomes of heterotrophic bacteria

    DOE PAGESBeta

    Russell, Joseph A.; Leon-Zayas, Rosa; Wrighton, Kelly; Biddle, Jennifer F.

    2016-05-10

    Studies of subsurface microorganisms have yielded few environmentally relevant isolates for laboratory studies. In order to address this lack of cultivated microorganisms, we initiated several enrichments on sediment and underlying basalt samples from North Pond, a sediment basin ringed by basalt outcrops underlying an oligotrophic watercolumn west of the Mid-Atlantic Ridge at 22° N. In contrast to anoxic enrichments, growth was observed in aerobic, heterotrophic enrichments from sediment of IODP Hole U1382B at 4 and 68 m below seafloor (mbsf). These sediment depths, respectively, correspond to the fringes of oxygen penetration from overlying seawater in the top of the sedimentmore » column and upward migration of oxygen from oxic seawater from the basalt aquifer below the sediment. Here we report the enrichment, isolation, initial characterization and genomes of three isolated aerobic heterotrophs from North Pond sediments; an Arthrobacter species from 4 mbsf, and Paracoccus and Pseudomonas species from 68 mbsf. These cultivated bacteria are represented in the amplicon 16S rRNA gene libraries created from whole sediments, albeit at low (up to 2%) relative abundance. We provide genomic evidence from our isolates demonstrating that the Arthrobacter and Pseudomonas isolates have the potential to respire nitrate and oxygen, though dissimilatory nitrate reduction could not be confirmed in laboratory cultures. Furthermore, the cultures from this study represent members of abundant phyla, as determined by amplicon sequencing of environmental DNA extracts, and allow for further studies into geochemical factors impacting life in the deep subsurface.« less

  18. Deep Subsurface Life from North Pond: Enrichment, Isolation, Characterization and Genomes of Heterotrophic Bacteria

    PubMed Central

    Russell, Joseph A.; León-Zayas, Rosa; Wrighton, Kelly; Biddle, Jennifer F.

    2016-01-01

    Studies of subsurface microorganisms have yielded few environmentally relevant isolates for laboratory studies. In order to address this lack of cultivated microorganisms, we initiated several enrichments on sediment and underlying basalt samples from North Pond, a sediment basin ringed by basalt outcrops underlying an oligotrophic water-column west of the Mid-Atlantic Ridge at 22°N. In contrast to anoxic enrichments, growth was observed in aerobic, heterotrophic enrichments from sediment of IODP Hole U1382B at 4 and 68 m below seafloor (mbsf). These sediment depths, respectively, correspond to the fringes of oxygen penetration from overlying seawater in the top of the sediment column and upward migration of oxygen from oxic seawater from the basalt aquifer below the sediment. Here we report the enrichment, isolation, initial characterization and genomes of three isolated aerobic heterotrophs from North Pond sediments; an Arthrobacter species from 4 mbsf, and Paracoccus and Pseudomonas species from 68 mbsf. These cultivated bacteria are represented in the amplicon 16S rRNA gene libraries created from whole sediments, albeit at low (up to 2%) relative abundance. We provide genomic evidence from our isolates demonstrating that the Arthrobacter and Pseudomonas isolates have the potential to respire nitrate and oxygen, though dissimilatory nitrate reduction could not be confirmed in laboratory cultures. The cultures from this study represent members of abundant phyla, as determined by amplicon sequencing of environmental DNA extracts, and allow for further studies into geochemical factors impacting life in the deep subsurface. PMID:27242705

  19. Deep Subsurface Life from North Pond: Enrichment, Isolation, Characterization and Genomes of Heterotrophic Bacteria.

    PubMed

    Russell, Joseph A; León-Zayas, Rosa; Wrighton, Kelly; Biddle, Jennifer F

    2016-01-01

    Studies of subsurface microorganisms have yielded few environmentally relevant isolates for laboratory studies. In order to address this lack of cultivated microorganisms, we initiated several enrichments on sediment and underlying basalt samples from North Pond, a sediment basin ringed by basalt outcrops underlying an oligotrophic water-column west of the Mid-Atlantic Ridge at 22°N. In contrast to anoxic enrichments, growth was observed in aerobic, heterotrophic enrichments from sediment of IODP Hole U1382B at 4 and 68 m below seafloor (mbsf). These sediment depths, respectively, correspond to the fringes of oxygen penetration from overlying seawater in the top of the sediment column and upward migration of oxygen from oxic seawater from the basalt aquifer below the sediment. Here we report the enrichment, isolation, initial characterization and genomes of three isolated aerobic heterotrophs from North Pond sediments; an Arthrobacter species from 4 mbsf, and Paracoccus and Pseudomonas species from 68 mbsf. These cultivated bacteria are represented in the amplicon 16S rRNA gene libraries created from whole sediments, albeit at low (up to 2%) relative abundance. We provide genomic evidence from our isolates demonstrating that the Arthrobacter and Pseudomonas isolates have the potential to respire nitrate and oxygen, though dissimilatory nitrate reduction could not be confirmed in laboratory cultures. The cultures from this study represent members of abundant phyla, as determined by amplicon sequencing of environmental DNA extracts, and allow for further studies into geochemical factors impacting life in the deep subsurface. PMID:27242705

  20. Deep Subsurface Life from North Pond: Enrichment, Isolation, Characterization and Genomes of Heterotrophic Bacteria.

    PubMed

    Russell, Joseph A; León-Zayas, Rosa; Wrighton, Kelly; Biddle, Jennifer F

    2016-01-01

    Studies of subsurface microorganisms have yielded few environmentally relevant isolates for laboratory studies. In order to address this lack of cultivated microorganisms, we initiated several enrichments on sediment and underlying basalt samples from North Pond, a sediment basin ringed by basalt outcrops underlying an oligotrophic water-column west of the Mid-Atlantic Ridge at 22°N. In contrast to anoxic enrichments, growth was observed in aerobic, heterotrophic enrichments from sediment of IODP Hole U1382B at 4 and 68 m below seafloor (mbsf). These sediment depths, respectively, correspond to the fringes of oxygen penetration from overlying seawater in the top of the sediment column and upward migration of oxygen from oxic seawater from the basalt aquifer below the sediment. Here we report the enrichment, isolation, initial characterization and genomes of three isolated aerobic heterotrophs from North Pond sediments; an Arthrobacter species from 4 mbsf, and Paracoccus and Pseudomonas species from 68 mbsf. These cultivated bacteria are represented in the amplicon 16S rRNA gene libraries created from whole sediments, albeit at low (up to 2%) relative abundance. We provide genomic evidence from our isolates demonstrating that the Arthrobacter and Pseudomonas isolates have the potential to respire nitrate and oxygen, though dissimilatory nitrate reduction could not be confirmed in laboratory cultures. The cultures from this study represent members of abundant phyla, as determined by amplicon sequencing of environmental DNA extracts, and allow for further studies into geochemical factors impacting life in the deep subsurface.

  1. Antibiotic resistance in lactic acid bacteria isolated from some pharmaceutical and dairy products

    PubMed Central

    Gad, Gamal Fadl M.; Abdel-Hamid, Ahmed M.; Farag, Zeinab Shawky H.

    2014-01-01

    A total of 244 lactic acid bacteria (LAB) strains were isolated from 180 dairy and pharmaceutical products that were collected from different areas in Minia governorate, Egypt. LAB were identified phenotypically on basis of morphological, physiological and biochemical characteristics. Lactobacillus isolates were further confirmed using PCR-based assay. By combination of phenotypic with molecular identification Lactobacillus spp. were found to be the dominant genus (138, 76.7%) followed by Streptococcus spp. (65, 36.1%) and Lactococcus spp. (27, 15%). Some contaminant organisms such as (Staphylococcus spp., Escherichia coli, Salmonella spp., mould and yeast) were isolated from the collected dairy samples but pharmaceutical products were free of such contaminants. Susceptibility of LAB isolates to antibiotics representing all major classes was tested by agar dilution method. Generally, LAB were highly susceptible to Beta-lactams except penicillin. Lactobacilli were resistant to vancomycin, however lactococci and streptococci proved to be very susceptible. Most strains were susceptible to tetracycline and showed a wide range of streptomycin MICs. The MICs of erythromycin and clindamycin for most of the LAB were within the normal range of susceptibility. Sixteen Lactobacillus, 8 Lactococcus and 8 Streptococcus isolates including all tetracycline and/or erythromycin resistant strains were tested for the presence of tetracycline and/or erythromycin resistant genes [tet(M) and/or erm(B)]. PCR assays shows that some resistant strains harbor tet(M) and/or erm(B) resistance genes. PMID:24948910

  2. Highly effective bacterial agents against Cimbex quadrimaculatus (Hymenoptera: Cimbicidae): isolation of bacteria and their insecticidal activities.

    PubMed

    Cakici, Filiz Ozkan; Ozgen, İnanc; Bolu, Halil; Erbas, Zeynep; Demirbağ, Zihni; Demir, İsmail

    2015-01-01

    Cimbex quadrimaculatus (Hymenoptera: Cimbicidae) is one of the serious pests of almonds in Turkey and worldwide. Since there is no effective control application against this pest, it has been a serious problem up to now. Therefore, we aimed to find an effective bacterium that can be utilized as a biocontrol agent against C. quadrimaculatus in pest management. We isolated seven bacteria from dead and live C. quadrimaculatus larvae, and evaluated the larvicidal potency of all isolates on the respective pest. Based on the morphological, physiological, biochemical and molecular properties (partial sequence of 16S rRNA gene), the isolates were identified to be Bacillus safensis (CQ1), Bacillus subtilis (CQ2), Bacillus tequilensis (CQ3), Enterobacter sp. (CQ4), Kurthia gibsonii (CQ5), Staphylococcus sp. (CQ6) and Staphylococcus sciuri (CQ7). The results of the larvicidal activities of these isolates indicated that the mortality value obtained from all treatments changed from 58 to 100 %, and reached 100 % with B. safensis (CQ1) and B. subtilis (CQ2) on the 3rd instar larvae within 10 days of application of 1.89 × 10(9) cfu/mL bacterial concentration at 25 °C under laboratory conditions. Findings from this study indicate that these isolates appear to be a promising biocontrol agent for C. quadrimaculatus.

  3. Bacteria isolated from dugongs (Dugong dugon) submitted for postmortem examination in Queensland, Australia, 2000-2011.

    PubMed

    Nielsen, Kristen A; Owen, Helen C; Mills, Paul C; Flint, Mark; Gibson, Justine S

    2013-03-01

    Microbial infection may contribute to disease in a significant proportion of marine mammal mortalities, but little is known about infectious bacterial species and their prevalence in dugongs (Dugong dugon). This study represents a survey of the species of bacteria and fungi isolated from dugongs submitted to the University of Queensland's School of Veterinary Science for postmortem examination. Thirty-six dugongs were included in the survey, with 23 species of bacteria and four species of fungus cultured from lesions that were suspected of contributing to local infection, systemic infection, or both. The most abundant bacteria included Aeromonas spp., Clostridium spp., Vibrio spp., Enterococcus faecalis, and Pseudomonas spp. In six cases, the microorganism(s) cultured were considered to have been associated with disease. Mixed infections containing Aeromonas spp. and Vibrio spp.; Morganella morganii, Pasteurella multocida, and Serratia marcescens; and Actinomyces spp. and Peptostreptococcus spp. were associated with pneumonia or pleuritis, and Enterococcus faecalis was associated with a multisystemic infection in a neonate. Clostridium spp. was cultured from two animals with peritonitis and likely septicemia. The significance of many of the other isolates is uncertain because the samples were taken after death, and some of the species isolated may represent postmortem overgrowth. It is also difficult to fulfil Koch's postulates through experimental infection in marine mammals. Regardless, this information will assist clinicians working with dugongs to make treatment decisions and the baseline data on the prevalence of bacterial and fungal species is of value for monitoring coastal water habitat health and risks of zoonotic disease transmission. PMID:23505701

  4. [Isolation and characterization of two bacteria with heavy metal resistance and phosphate solubilizing capability].

    PubMed

    Tian, Jiang; Peng, Xia-Wei; Li, Xia; Sun, Ya-Jun; Feng, Hong-Mei; Jiang, Ze-Ping

    2014-06-01

    Two phosphate solubilizing bacteria (T PSB1 and T PSB 2) with high heavy metal resistance were isolated from soil of a lead-zinc mine in Huayuan of Hunan Province, China. These two bacteria were identified as Stenotrophomonas maltophilia and Burkholderia gladioli by 16S rRNA sequencing analysis, respectively. In the media containing insoluble inorganic calcium phosphate, the soluble phosphate amounts reached respectively 402.9 mg x L(-1) and 589.9 mg x L(-1) with the bacteria T PSB1 and T PSB2 after two weeks' growth. Moreover, the two bacteria developed solubilizing halos on the plates supplemented with the organic phosphate compounds, and the resulting soluble phosphate amounts in the broth media were respectively 2.97 mg x L(-1) and 4.69 mg x L(-1). In addition, these two bacteria showed the resistance to up to 2000 mg x L(-1) Zn2+, and their phosphate solubilizing amounts reached respectively 114.8 mg x L(-1) and 125.1 mg x L(-1). Similarly, their heavy metal resistance and phosphate solubilizing ability were also found in the Cr and Pb broth media with the concentration of 1000 mg x L(-1). In the Pb media, the soluble phosphate amounts reached respectively 57.9 mg x L(-1) and 71.7 mg x L(-1), and the soluble P amounts in the Cr media were 60.1 mg x L(-1) and 98.4 mg x L(-1) at the concentration of 1000 mg x L(-1).

  5. Isolation, Identification and Phenotypic Characterization of Microcystin-Degrading Bacteria from Lake Erie

    NASA Astrophysics Data System (ADS)

    Krishnan, A.; Mou, X. J.

    2015-12-01

    Lake Erie, the smallest and warmest lake among the Laurentian Great Lakes, is known for its problem of eutrophication and frequent occurrence of harmful cyanobacterial blooms (CyanoHABs). One major harmful effect of CyanoHABs is the production of cyanotoxins, especially microcystins. Microcystins (MC) are a group of hepatotoxins and the predominant variant of them is MC-LR. Field measurements and lab experiments indicate that MC degradation in Lake Erie is mainly carried out by indigenous bacteria. However, our knowledge on taxa involved in this process is very limited. This study aimed to fill this knowledge gap using a culture-dependent approach. Water and surface sediment samples were collected from Lake Erie in 2014 and 2015 and enriched with MC-LR. Cells were plated on a number of culturing media. The obtained pure bacterial cultures were screened for MC degrading abilities by MT2 BIO-LOG assays and by growing cells in liquid media containing MC-LR as the sole carbon source. In the latter experiment, MC concentrations were measured using HPLC. Isolates showing positive MC degradation activities in the screening steps were designated MC+ bacteria and characterized based on their phenotypic properties, including colony pigmentation, elevation, opacity, margin, gram nature and motility. The taxonomic identity of MC+ bacteria was determined by 16S rRNA gene full-length DNA sequencing. The presence of mlrA, a gene encoding MC cleavage pathway, was detected by PCR. Our culturing efforts obtained 520 pure cultures; 44 of them were identified as MC+. These MC+ isolates showed diversity in taxonomic identities and differed in their morphology, gram nature, colony characteristics and motility. PCR amplification of mlrA gene yield negative results for all MC+ isolates, indicating that the primers that were used may not be ubiquitous enough to cover the heterogeneity of mlrA genes or, more likely, alternative degradative genes/pathways were employed by Lake Erie bacteria

  6. Isolation of Optically Targeted Single Bacteria by Application of Fluidic Force Microscopy to Aerobic Anoxygenic Phototrophs from the Phyllosphere

    PubMed Central

    Stiefel, Philipp; Zambelli, Tomaso

    2013-01-01

    In their natural environment, bacteria often behave differently than they do under laboratory conditions. To gain insight into the physiology of bacteria in situ, dedicated approaches are required to monitor their adaptations and specific behaviors under environmental conditions. Optical microscopy is crucial for the observation of fundamental characteristics of bacteria, such as cell shape, size, and marker gene expression. Here, fluidic force microscopy (FluidFM) was exploited to isolate optically selected bacteria for subsequent identification and characterization. In this study, bacteriochlorophyll-producing bacteria, which can be visualized due to their characteristic fluorescence in the infrared range, were isolated from leaf washes. Bacterial communities from the phyllosphere were investigated because they harbor genes indicative of aerobic anoxygenic photosynthesis. Our data show that different species of Methylobacterium express their photosystem in planta, and they show a distinct pattern of bacteriochlorophyll production under laboratory conditions that is dependent on supplied carbon sources. PMID:23770907

  7. Isolation and Characterization of α-Endosulfan Degrading Bacteria from the Microflora of Cockroaches.

    PubMed

    Ozdal, Murat; Ozdal, Ozlem Gur; Alguri, Omer Faruk

    2016-01-01

    Extensive applications of organochlorine pesticides like endosulfan have led to the contamination of soil and environments. Five different bacteria were isolated from cockroaches living in pesticide contaminated environments. According to morphological, physiological, biochemical properties, and total cellular fatty acid profile by Fatty Acid Methyl Esters (FAMEs), the isolates were identified as Pseudomonas aeruginosa G1, Stenotrophomonas maltophilia G2, Bacillus atrophaeus G3, Citrobacter amolonaticus G4 and Acinetobacter lwoffii G5. This is the first study on the bacterial flora of Blatta orientalis evaluated for the biodegradation of α-endosulfan. After 10 days of incubation, the biodegradation yields obtained from P. aeruginosa G1, S. maltophilia G2, B. atrophaeus G3, C. amolonaticus G4 and A. lwoffii G5 were 88.5% , 85.5%, 64.4%, 56.7% and 80.2%, respectively. As a result, these bacterial strains may be utilized for biodegradation of endosulfan polluted soil and environments.

  8. Molecular detection and isolation from antarctica of methylotrophic bacteria able to grow with methylated sulfur compounds.

    PubMed

    Moosvi, S Azra; McDonald, Ian R; Pearce, David A; Kelly, Donovan P; Wood, Ann P

    2005-08-01

    This study is the first demonstration that a diverse facultatively methylotrophic microbiota exists in some Antarctic locations. PCR amplification of genes diagnostic for methylotrophs was carried out with bacterial DNA isolated from 14 soil and sediment samples from ten locations on Signy Island, South Orkney Islands, Antarctica. Genes encoding the mxaF of methanol dehydrogenase, the fdxA for Afipia ferredoxin, the msmA of methanesulfonate monooxygenase, and the 16S rRNA gene of Methylobacterium were detected in all samples tested. The mxaF gene sequences corresponded to those of Hyphomicrobium, Methylobacterium, and Methylomonas. Over 30 pure cultures of methylotrophs were isolated on methanesulfonate, dimethylsulfone, or dimethylsulfide from ten Signy Island lakes. Some were identified from 16S rRNA gene sequences (and morphology) as Hyphomicrobium species, strains of Afipia felis, and a methylotrophic Flavobacterium strain. Antarctic environments thus contain diverse methylotrophic bacteria, growing on various C1-substrates, including C1-sulfur compounds. PMID:16104352

  9. Isolation of carotenoid-deficient mutant from alkylated dibenzothiophene desulfurizing nocardioform bacteria, Gordonia sp. TM414.

    PubMed

    Matsui, Toru; Maruhashi, Kenji

    2004-02-01

    The dibenzothiophene-desulfurizing nocardioform bacteria, Gordonia sp. TM414, was isolated from oil-contaminated soil. To avoid coloration of the oil layer after the desulfurization reaction, which could decrease the quality of the oil, two colorless knock-out mutants, TPc and TPd, were isolated by using a broad-host-range transposon complex. Genomic sequence analysis revealed that the same gene was disrupted in these mutants and that the transposon-inserted gene was assigned as the gene for phytoene desaturase, crt I. The crt I mutants also showed desulfurization activity comparable to that of the parent strain in a model-oil/aqueous bi-phasic reaction, suggesting that the carotenoid production is not responsible for the bi-phasic desulfurization reaction that requires hydrophobic substrate incorporation from the organic phase.

  10. Laboratory identification of anaerobic bacteria isolated on Clostridium difficile selective medium.

    PubMed

    Rodriguez, Cristina; Warszawski, Nathalie; Korsak, Nicolas; Taminiau, Bernard; Van Broeck, Johan; Delmée, Michel; Daube, Georges

    2016-06-01

    Despite increasing interest in the bacterium, the methodology for Clostridium difficile recovery has not yet been standardized. Cycloserine-cefoxitin fructose taurocholate (CCFT) has historically been the most used medium for C. difficile isolation from human, animal, environmental, and food samples, and presumptive identification is usually based on colony morphologies. However, CCFT is not totally selective. This study describes the recovery of 24 bacteria species belonging to 10 different genera other than C. difficile, present in the environment and foods of a retirement establishment that were not inhibited in the C. difficile selective medium. These findings provide insight for further environmental and food studies as well as for the isolation of C. difficile on supplemented CCFT.

  11. Inhibitory activity of Aloe vera gel on some clinically isolated cariogenic and periodontopathic bacteria.

    PubMed

    Fani, Mohammadmehdi; Kohanteb, Jamshid

    2012-03-01

    Aloe vera is a medicinal plant with anti-inflammatory, antimicrobial, antidiabetic and immune-boosting properties. In the present study we investigated the inhibitory activities of Aloe vera gel on some cariogenic (Streptococcus mutans), periodontopathic (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis) and an opportunistic periodontopathogen (Bacteroides fragilis) isolated from patients with dental caries and periodontal diseases. Twenty isolates of each of these bacteria were investigated for their sensitivity to Aloe vera gel using the disk diffusion and microdilution methods. S. mutans was the species most sensitive to Aloe vera gel with a MIC of 12.5 µg/ml, while A. actinomycetemcomitans, P. gingivalis, and B. fragilis were less sensitive, with a MIC of 25-50 µg/ml (P < 0.01). Based on our present findings it is concluded that Aloe vera gel at optimum concentration could be used as an antiseptic for prevention of dental caries and periodontal diseases.

  12. Biotransformation of phosphogypsum by bacteria isolated from petroleum-refining wastewaters.

    PubMed

    Wolicka, Dorota; Kowalski, Włodzimierz; Boszczyk-Maleszak, Hanka

    2005-01-01

    The biotransformation of phosphogypsum in cultures of sulfate-reducing bacteria (SRB) isolated from crude petroleum-refining wastewaters or purified using activated sludge method was studied. Selection was with the microcosms method on Postgate and minimal medium with different carbon sources, Emerson medium and petroleum-refining wastewaters. Highest hydrogen sulfide production, in excess of 500 mg/L, was observed in culture of microorganisms isolated from purified petroleum-refining wastewaters in Postgate medium with phenol as sole carbon source. 76% phenol reduction with simultaneous biotransformation of 2.7g phosphogypsum/L (1350 mg SO4/L) was obtained. The results regarding post-culture sediment indicated 66% utilization of phosphogypsum introduced into the culture (5 g/L), which reflects the active biotransformation of phosphogypsum by the community selected from the wastewaters.

  13. Isolation and Characterization of α-Endosulfan Degrading Bacteria from the Microflora of Cockroaches.

    PubMed

    Ozdal, Murat; Ozdal, Ozlem Gur; Alguri, Omer Faruk

    2016-01-01

    Extensive applications of organochlorine pesticides like endosulfan have led to the contamination of soil and environments. Five different bacteria were isolated from cockroaches living in pesticide contaminated environments. According to morphological, physiological, biochemical properties, and total cellular fatty acid profile by Fatty Acid Methyl Esters (FAMEs), the isolates were identified as Pseudomonas aeruginosa G1, Stenotrophomonas maltophilia G2, Bacillus atrophaeus G3, Citrobacter amolonaticus G4 and Acinetobacter lwoffii G5. This is the first study on the bacterial flora of Blatta orientalis evaluated for the biodegradation of α-endosulfan. After 10 days of incubation, the biodegradation yields obtained from P. aeruginosa G1, S. maltophilia G2, B. atrophaeus G3, C. amolonaticus G4 and A. lwoffii G5 were 88.5% , 85.5%, 64.4%, 56.7% and 80.2%, respectively. As a result, these bacterial strains may be utilized for biodegradation of endosulfan polluted soil and environments. PMID:27281995

  14. Isolation of Bacteria Whose Growth Is Dependent on High Levels of CO2 and Implications of Their Potential Diversity▿ †

    PubMed Central

    Ueda, Kenji; Tagami, Yudai; Kamihara, Yuka; Shiratori, Hatsumi; Takano, Hideaki; Beppu, Teruhiko

    2008-01-01

    Although some bacteria require an atmosphere with high CO2 levels for their growth, CO2 is not generally supplied to conventional screening cultures. Here, we isolated 84 bacterial strains exhibiting high-CO2 dependence. Their phylogenetic affiliations imply that high-CO2 culture has potential as an effective method to isolate unknown microorganisms. PMID:18487395

  15. Bacteriocinogenic Bacteria Isolated from Raw Goat Milk and Goat Cheese Produced in the Center of México.

    PubMed

    Hernández-Saldaña, Oscar F; Valencia-Posadas, Mauricio; de la Fuente-Salcido, Norma M; Bideshi, Dennis K; Barboza-Corona, José E

    2016-09-01

    Currently, there are few reports on the isolation of microorganisms from goat milk and goat cheese that have antibacterial activity. In particular, there are no reports on the isolation of microorganisms with antibacterial activity from these products in central Mexico. Our objective was to isolate bacteria, from goat products, that synthesized antimicrobial peptides with activity against a variety of clinically significant bacteria. We isolated and identified Lactobacillus rhamnosus, L. plantarum, L. pentosus, L. helveticus and Enterococcus faecium from goat cheese, and Aquabacterium fontiphilum, Methylibium petroleiphilum, Piscinobacter aquaticus and Staphylococcus xylosus from goat milk. These bacteria isolated from goat cheese were able to inhibit Staphylococcus aureus, Bacillus cereus, Escherichia coli, Listeria monocytogenes, L. inoccua, Pseudomona aeruginosa, Shigella flexneri, Serratia marcescens, Enterobacter cloacae and Klebsiella pneumoniae. In addition, bacteria from goat milk showed inhibitory activity against B. cereus, L. lactis, E. coli, S. flexneri, E. cloacae and K. pneumonia; S. aureus, L. innocua, S. agalactiae and S. marcescens. The bacteriocins produced by these isolates were shown to be acid stable (pH 2-6) and thermotolerant (up to 100 °C), but were susceptible to proteinases. When screened by PCR for the presence of nisin, pediocin and enterocin A genes, none was found in isolates recovered from goat milk, and only the enterocin A gene was found in isolates from goat cheese.

  16. Bacteriocinogenic Bacteria Isolated from Raw Goat Milk and Goat Cheese Produced in the Center of México.

    PubMed

    Hernández-Saldaña, Oscar F; Valencia-Posadas, Mauricio; de la Fuente-Salcido, Norma M; Bideshi, Dennis K; Barboza-Corona, José E

    2016-09-01

    Currently, there are few reports on the isolation of microorganisms from goat milk and goat cheese that have antibacterial activity. In particular, there are no reports on the isolation of microorganisms with antibacterial activity from these products in central Mexico. Our objective was to isolate bacteria, from goat products, that synthesized antimicrobial peptides with activity against a variety of clinically significant bacteria. We isolated and identified Lactobacillus rhamnosus, L. plantarum, L. pentosus, L. helveticus and Enterococcus faecium from goat cheese, and Aquabacterium fontiphilum, Methylibium petroleiphilum, Piscinobacter aquaticus and Staphylococcus xylosus from goat milk. These bacteria isolated from goat cheese were able to inhibit Staphylococcus aureus, Bacillus cereus, Escherichia coli, Listeria monocytogenes, L. inoccua, Pseudomona aeruginosa, Shigella flexneri, Serratia marcescens, Enterobacter cloacae and Klebsiella pneumoniae. In addition, bacteria from goat milk showed inhibitory activity against B. cereus, L. lactis, E. coli, S. flexneri, E. cloacae and K. pneumonia; S. aureus, L. innocua, S. agalactiae and S. marcescens. The bacteriocins produced by these isolates were shown to be acid stable (pH 2-6) and thermotolerant (up to 100 °C), but were susceptible to proteinases. When screened by PCR for the presence of nisin, pediocin and enterocin A genes, none was found in isolates recovered from goat milk, and only the enterocin A gene was found in isolates from goat cheese. PMID:27407294

  17. Characteristics of lactic acid bacteria isolates and their effect on silage fermentation of fruit residues.

    PubMed

    Yang, Jinsong; Tan, Haisheng; Cai, Yimin

    2016-07-01

    The natural lactic acid bacteria (LAB) population, chemical composition, and silage fermentation of fruit residues were studied. Eighty-two strains of LAB were isolated from fruit residues such as banana leaf and stem, pineapple peel, and papaya peel. All strains were gram-positive and catalase-negative bacteria, and they were divided into 7 groups (A-G) according to morphological and biochemical characters. Strains in groups A to F were rods, and group G was cocci. Group F produced gas from glucose; other groups did not. Groups A to C and F formed dl-lactic acid, whereas groups D, E, and G formed l-lactic acid. Based on the 16S rRNA gene sequence and DNA-DNA hybridization analysis, groups A to G strains were identified as Lactobacillus plantarum (54.9% of the total isolates), Lactobacillus paraplantarum (3.6%), Lactobacillus nagelii (8.5%), Lactobacillus perolens (4.9%), Lactobacillus casei (11.0%), Lactobacillus fermentum (9.8%), and Enterococcus gallinarum (7.3%), respectively. Lactobacillus plantarum and Lactobacillus casei are the most frequently isolated from fruit residues as a dominant species, and they could grow at a lower pH conditions and produce more lactic acid than other isolates. Pineapple and papaya peels contained higher crude protein (11.5-13.8%) and water-soluble carbohydrate (16.8-22.4%), but lower acid detergent fiber contents (21.2 to 26.4%) than banana stems and leaves (8.2% crude protein, 42.8% acid detergent fiber, and 5.1% water-soluble carbohydrate). Compared with banana stem and leaf silages, the pineapple and papaya peel silages were well preserved with a lower pH and higher lactate content. The study suggests that the fruit residues contain excellent LAB species and abundant feed nutrients, and that they can be preserved as silage to be potential food resources for livestock. PMID:27108171

  18. Characteristics of lactic acid bacteria isolates and their effect on silage fermentation of fruit residues.

    PubMed

    Yang, Jinsong; Tan, Haisheng; Cai, Yimin

    2016-07-01

    The natural lactic acid bacteria (LAB) population, chemical composition, and silage fermentation of fruit residues were studied. Eighty-two strains of LAB were isolated from fruit residues such as banana leaf and stem, pineapple peel, and papaya peel. All strains were gram-positive and catalase-negative bacteria, and they were divided into 7 groups (A-G) according to morphological and biochemical characters. Strains in groups A to F were rods, and group G was cocci. Group F produced gas from glucose; other groups did not. Groups A to C and F formed dl-lactic acid, whereas groups D, E, and G formed l-lactic acid. Based on the 16S rRNA gene sequence and DNA-DNA hybridization analysis, groups A to G strains were identified as Lactobacillus plantarum (54.9% of the total isolates), Lactobacillus paraplantarum (3.6%), Lactobacillus nagelii (8.5%), Lactobacillus perolens (4.9%), Lactobacillus casei (11.0%), Lactobacillus fermentum (9.8%), and Enterococcus gallinarum (7.3%), respectively. Lactobacillus plantarum and Lactobacillus casei are the most frequently isolated from fruit residues as a dominant species, and they could grow at a lower pH conditions and produce more lactic acid than other isolates. Pineapple and papaya peels contained higher crude protein (11.5-13.8%) and water-soluble carbohydrate (16.8-22.4%), but lower acid detergent fiber contents (21.2 to 26.4%) than banana stems and leaves (8.2% crude protein, 42.8% acid detergent fiber, and 5.1% water-soluble carbohydrate). Compared with banana stem and leaf silages, the pineapple and papaya peel silages were well preserved with a lower pH and higher lactate content. The study suggests that the fruit residues contain excellent LAB species and abundant feed nutrients, and that they can be preserved as silage to be potential food resources for livestock.

  19. Identification and characterization of two bacteriocin-producing bacteria isolated from garlic and ginger root.

    PubMed

    Janes, M E; Nannapaneni, R; Johnson, M G

    1999-08-01

    Two bacteriocin-producing bacterial strains were isolated from garlic and ginger root by the agar overlay method. The bacteria were identified by 16S rRNA sequence analyses and fermentation patterns as Leuconostoc mesenteroides (garlic isolate) and Lactococcus lactis (ginger isolate). The bacteriocins were assigned the names leucocin BC2 and lactocin GI3, respectively. Physiochemical properties and antimicrobial spectra of the bacteriocins were determined by the spot-on-lawn method. Both bacteriocins were inhibited by proteolytic enzymes. Leucocin BC2 exhibited a narrow antimicrobial spectrum, inhibiting only Bacillus, Enterococcus, and Listeria species. Lactocin GI3 had a broader spectrum, inhibiting Bacillus, Clostridium, Listeria, Enterococcus, Leuconostoc, Pediococcus, and Staphylococcus species. Both bacteriocins remained active when heated at 90 degrees C for 15 min or 120 degrees C for 20 min. Leucocin BC2 assayed at 37 degrees C showed an inhibitory activity of 1,600 AU/ml, whereas at 8 degrees C the activity was 12,800 AU/ml. Conversely, lactocin GI3 activity was the same at both assay temperatures. Both bacteriocins remained active over a pH range of 2.0 to 9.0 and in various organic solvents. The activity of leucocin BC2 was increased when treated with 0.5% acetic acid and 0.5% lactic acid, whereas lactocin GI3 activity was decreased with either acid. The molecular mass values were 3.7 kDa for leucocin BC2 and 3.9 kDa for lactocin GI3. These results show that the inhibitory substances produced by the bacteria isolated from garlic and ginger are bacteriocins that appear to be different in some characteristics from previously reported bacteriocins. PMID:10456744

  20. Isolation of bacteria from remote high altitude Andean lakes able to grow in the presence of antibiotics.

    PubMed

    Dib, Julián R; Weiss, Annika; Neumann, Anna; Ordoñez, Omar; Estévez, María C; Farías, Maria E

    2009-01-01

    High altitude Andean lakes are placed in Puna desert over 4400 above sea level. Completely isolated, they are exposed to extreme environmental factors like high levels of salinity, UV radiation and heavy metals and low concentrations of phosphorus. Nevertheless, they are the habitat of enormous populations of three flamingo species that migrate among these Lakes. Previous reports have determined that bacteria isolated from these environments present high levels of resistance to antibiotics. The aim of this work was to determine the diversity of antibiotic resistant bacteria in water from Andean Lakes and their connection with flamingo enteric biota. Bacteria from water and birds faeces from high altitude Lakes: Laguna (L.) Aparejos, L. Negra, L. Vilama and L. Azul (all are located between 4,200 and 4,600 m altitude) were isolated by plating in five different Antibiotics (ampicillin, 100 microg ml(-1); chloramphenicol, 170 microg ml(-1); colistin , 20 microg ml(-1); erythromycin, 50 microg ml(-1) and tetracycline 50 microg ml(-1)). 56 bacteria were isolated and identified by 16 S rDNA sequencing. Antibiotic resistance profiles of isolated bacteria were determined for 22 different antibiotics. All identified bacteria were able to growth in multiple ATBs. Colistin, ceftazidime, ampicillin/sulbactam, cefotaxime, cefepime, cefalotin, ampicillin and erythromycin were the most distributed resistances among the 56 tested bacteria. The current results demonstrated that antibiotic resistance was abundant and diverse in high altitude Lakes. Also the present article indicates some useful patents regarding the isolation of bacteria able to grow in the present of antibiotics. PMID:19149698

  1. A Glutamic Acid-Producing Lactic Acid Bacteria Isolated from Malaysian Fermented Foods

    PubMed Central

    Zareian, Mohsen; Ebrahimpour, Afshin; Bakar, Fatimah Abu; Mohamed, Abdul Karim Sabo; Forghani, Bita; Ab-Kadir, Mohd Safuan B.; Saari, Nazamid

    2012-01-01

    l-glutamaic acid is the principal excitatory neurotransmitter in the brain and an important intermediate in metabolism. In the present study, lactic acid bacteria (218) were isolated from six different fermented foods as potent sources of glutamic acid producers. The presumptive bacteria were tested for their ability to synthesize glutamic acid. Out of the 35 strains showing this capability, strain MNZ was determined as the highest glutamic-acid producer. Identification tests including 16S rRNA gene sequencing and sugar assimilation ability identified the strain MNZ as Lactobacillus plantarum. The characteristics of this microorganism related to its glutamic acid-producing ability, growth rate, glucose consumption and pH profile were studied. Results revealed that glutamic acid was formed inside the cell and excreted into the extracellular medium. Glutamic acid production was found to be growth-associated and glucose significantly enhanced glutamic acid production (1.032 mmol/L) compared to other carbon sources. A concentration of 0.7% ammonium nitrate as a nitrogen source effectively enhanced glutamic acid production. To the best of our knowledge this is the first report of glutamic acid production by lactic acid bacteria. The results of this study can be further applied for developing functional foods enriched in glutamic acid and subsequently γ-amino butyric acid (GABA) as a bioactive compound. PMID:22754309

  2. Recurrent Isolation of Extremotolerant Bacteria from the Clean Room Where Phoenix Spacecraft Components Were Assembled

    NASA Astrophysics Data System (ADS)

    Ghosh, Sudeshna; Osman, Shariff; Vaishampayan, Parag; Venkateswaran, Kasthuri

    2010-04-01

    The microbial burden of the Phoenix spacecraft assembly environment was assessed in a systematic manner via several cultivation-based techniques and a suite of NASA-certified, cultivation-independent biomolecule-based detection assays. Extremotolerant bacteria that could potentially survive conditions experienced en route to Mars or on the planet's surface were isolated with a series of cultivation-based assays that promoted the growth of a variety of organisms, including spore formers, mesophilic heterotrophs, anaerobes, thermophiles, psychrophiles, alkaliphiles, and bacteria resistant to UVC radiation and hydrogen peroxide exposure. Samples were collected from the clean room where Phoenix was housed at three different time points, before (1P), during (2P), and after (3P) Phoenix's presence at the facility. There was a reduction in microbial burden of most bacterial groups, including spore formers, in samples 2P and 3P. Analysis of 262 isolatisolattivable bacterial populations accompanied by a reduction in diversity during 2P and 3P. It is suggested that this shift was a result of increased cleaning when Phoenix was present in the assembly facility and that certain species, such as Acinetobacter johnsonii and Brevundimonas diminuta, may be better adapted to environmental conditions found during 2P and 3P. In addition, problematic bacteria resistant to multiple extreme conditions, such as Bacillus pumilus, were able to survive these periods of increased cleaning.

  3. Cultivation and isolation of N2-fixing bacteria from suboxic waters in the Baltic Sea.

    PubMed

    Bentzon-Tilia, Mikkel; Farnelid, Hanna; Jürgens, Klaus; Riemann, Lasse

    2014-05-01

    Nitrogenase genes (nifH) from heterotrophic dinitrogen (N2)-fixing bacteria appear ubiquitous in marine bacterioplankton, but the significance of these bacteria for N cycling is unknown. Quantitative data on the N2-fixation potential of marine and estuarine heterotrophs are scarce, and the shortage of cultivated specimens currently precludes ecophysiological characterization of these bacteria. Through the cultivation of diazotrophs from suboxic (1.79 μmol O2 L(-1)) Baltic Sea water in an artificial seawater medium devoid of combined N, we report the cultivability of a considerable fraction of the diazotrophic community in the Gotland Deep. Two nifH clades were present both in situ and in enrichment cultures showing gene abundances of up to 4.6 × 10(5) and 5.8 × 10(5) nifH gene copies L(-1) within two vertical profiles in the Baltic Sea. The distributions of the two clades suggested a relationship with the O2 concentrations in the water column as abundances increased in the suboxic and anoxic waters. It was possible to cultivate and isolate representatives from one of these prevalent clades, and preliminary analysis of their ecophysiology demonstrated growth optima at 0.5-15 μmol O2 L(-1) and 186-194 μmol O2 L(-1) in the absence of combined N. PMID:24579891

  4. Antibacterial activity of Lactobacillus spp. isolated from the feces of healthy infants against enteropathogenic bacteria.

    PubMed

    Davoodabadi, Abolfazl; Soltan Dallal, Mohammad Mehdi; Rahimi Foroushani, Abbas; Douraghi, Masoumeh; Sharifi Yazdi, Mohammad Kazem; Amin Harati, Farzaneh

    2015-08-01

    Lactobacilli are normal microflora of the gastrointestinal (GI) tract and are a heterogeneous group of lactic acid bacteria (LAB). Lactobacillus strains with Probiotic activity may have health Benefits for human. This study investigates the probiotic potential of Lactobacillus strains obtained from the feces of healthy infants and also explores antibacterial activity of Lactobacillus strains with probiotic potential against enteropathogenic bacteria. Fecal samples were collected from 95 healthy infants younger than 18 months. Two hundred and ninety Lactobacillus strains were isolated and assessed for probiotic potential properties including ability to survive in gastrointestinal conditions (pH 2.0, 0.3% oxgall), adherence to HT-29 cells and antibiotic resistance. Six strains including Lactobacillus fermentum (4 strains), Lactobacillus paracasei and Lactobacillus plantarum showed good probiotic potential and inhibited the growth of enteropathogenic bacteria including ETEC H10407, Shigella flexneri ATCC 12022, Shigella sonnei ATCC 9290, Salmonella enteritidis H7 and Yersinia enterocolitica ATCC 23715. These Lactobacillus strains with probiotic potential may be useful for prevention or treatment of diarrhea, but further in vitro and in vivo studies on these strains are still required.

  5. [Inactivation of the chlorine-resistant bacteria isolated from the drinking water distribution system].

    PubMed

    Chen, Yu-Qiao; Duan, Xiao-Di; Lu, Pin-Pin; Wang, Qian; Zhang, Xiao-Jian; Chen, Chao

    2012-01-01

    Inactivation experiments of seven strains of chlorine-resistant bacteria, isolated from a drinking water distribution system, were conducted with four kinds of disinfectants. All the bacteria showed high resistance to chlorine, especially for Mycobacterium mucogenicum. The CT value of 99.9% inactivation for M. mucogenicum, Sphingomonas sanguinis and Methylobacterium were 120 mg x (L x min)(-1), 7 mg x (L x min)(-1) and 4 mg x (L x min)(-1), respectively. The results of inactivation experiments showed that chlorine dioxide and potassium monopersulfate could inactive 5 lg of M. mucogenicum within 30 min, which showed significantly higher efficiency than free chlorine and monochloramine. Free chlorine was less effective because the disinfectant decayed very quickly. Chloramination needed higher concentration to meet the disinfection requirements. The verified dosage of disinfectants, which could effectively inactivate 99.9% of the highly chlorine-resistant M. mucogenicum within 1 h, were 3.0 mg/L monochloramine, 1.0 mg/L chlorine dioxide (as Cl2), and 1.0 mg/L potassium monopersulfate (as Cl2). It was suggested that the water treatment plants increase the concentration of monochloramine or apply chlorine dioxide intermittently to control the disinfectant-resistant bacteria.

  6. Screening and isolation of PHB-producing bacteria in a polluted marine microbial mat.

    PubMed

    López-Cortés, Alejandro; Lanz-Landázuri, Alberto; García-Maldonado, José Q

    2008-07-01

    The characteristics of microbial mats within the waste stream from a seafood cannery were compared to a microbial community at a pristine site near a sandy beach at Puerto San Carlos, Baja California Sur, Mexico. Isolation of poly-beta-hydroxybutyrate (PHB)-producing bacteria, recognition of brightly refractile cytoplasmatic inclusions, lipophilic stains with Sudan Black and Nile Red, and chemical extraction of PHB were used as a culture-dependent strategy for the detection of PHB-producing bacteria. The culture-independent approach included denaturing gradient gel electrophoresis of phylotypes of 16S rRNA of microbial communities from environmental samples. Significant differences in community structure were found among the polluted and pristine sites. These differences were correlated with the physicochemical characteristics of the seawater column. At the polluted site, the seawater was rich in nutrients (ammonia, phosphates, and organic matter), compared to the pristine location. Partial sequencing of 16S rDNA of cultures of bacteria producing PHB included Bacillus and Staphylococcus at both sites; Paracoccus and Micrococcus were found only at the polluted site and Rhodococcus and Methylobacterium were found only at the pristine site. Bands of the sequences of 16S rDNA from both field samples in the denaturing gradient gel electrophoresis (DGGE) analyses affiliated closely only with bacterial sequences of cultures of Bacillus and Staphylococcus. High concentrations of organic and inorganic nutrients at the polluted site had a clear effect on the composition and diversity of the microbial community compared to the unpolluted site.

  7. Selection and characterization of biofuel-producing environmental bacteria isolated from vegetable oil-rich wastes.

    PubMed

    Escobar-Niño, Almudena; Luna, Carlos; Luna, Diego; Marcos, Ana T; Cánovas, David; Mellado, Encarnación

    2014-01-01

    Fossil fuels are consumed so rapidly that it is expected that the planet resources will be soon exhausted. Therefore, it is imperative to develop alternative and inexpensive new technologies to produce sustainable fuels, for example biodiesel. In addition to hydrolytic and esterification reactions, lipases are capable of performing transesterification reactions useful for the production of biodiesel. However selection of the lipases capable of performing transesterification reactions is not easy and consequently very few biodiesel producing lipases are currently available. In this work we first isolated 1,016 lipolytic microorganisms by a qualitative plate assay. In a second step, lipolytic bacteria were analyzed using a colorimetric assay to detect the transesterification activity. Thirty of the initial lipolytic strains were selected for further characterization. Phylogenetic analysis revealed that 23 of the bacterial isolates were Gram negative and 7 were Gram positive, belonging to different clades. Biofuel production was analyzed and quantified by gas chromatography and revealed that 5 of the isolates produced biofuel with yields higher than 80% at benchtop scale. Chemical and viscosity analysis of the produced biofuel revealed that it differed from biodiesel. This bacterial-derived biofuel does not require any further downstream processing and it can be used directly in engines. The freeze-dried bacterial culture supernatants could be used at least five times for biofuel production without diminishing their activity. Therefore, these 5 isolates represent excellent candidates for testing biofuel production at industrial scale.

  8. Accelerated decolorization of reactive azo dyes under saline conditions by bacteria isolated from Arabian seawater sediment.

    PubMed

    Khalid, Azeem; Kausar, Farzana; Arshad, Muhammad; Mahmood, Tariq; Ahmed, Iftikhar

    2012-12-01

    Presence of huge amount of salts in the wastewater of textile dyeing industry is one of the major limiting factors in the development of an effective biotreatment system for the removal of azo dyes from textile effluents. Bacterial spp. capable of thriving under high salt conditions could be employed for the treatment of saline dyecontaminated textile wastewaters. The present study was aimed at isolating the most efficient bacterial strains capable of decolorizing azo dyes under high saline conditions. Fiftyeight bacterial strains were isolated from seawater, seawater sediment, and saline soil, using mineral salt medium enriched with 100 mg l−1 Reactive Black-5 azo dye and 50 g NaCl l−1 salt concentration. Bacterial strains KS23 (Psychrobacter alimentarius) and KS26 (Staphylococcus equorum) isolated from seawater sediment were able to decolorize three reactive dyes including Reactive Black 5, Reactive Golden Ovifix, and Reactive Blue BRS very efficiently in liquid medium over a wide range of salt concentration (0-100 g NaCl l)⁻¹. Time required for complete decolorization of 100 mg dye l ⁻¹ varied with the type of dye and salt concentration. In general, there was an inverse linear relationship between the velocity of the decolorization reaction (V) and salt concentration. This study suggested that bacteria isolated from saline conditions such as seawater sediment could be used in designing a bioreactor for the treatment of textile effluent containing high concentration of salts.

  9. Selection and characterization of biofuel-producing environmental bacteria isolated from vegetable oil-rich wastes.

    PubMed

    Escobar-Niño, Almudena; Luna, Carlos; Luna, Diego; Marcos, Ana T; Cánovas, David; Mellado, Encarnación

    2014-01-01

    Fossil fuels are consumed so rapidly that it is expected that the planet resources will be soon exhausted. Therefore, it is imperative to develop alternative and inexpensive new technologies to produce sustainable fuels, for example biodiesel. In addition to hydrolytic and esterification reactions, lipases are capable of performing transesterification reactions useful for the production of biodiesel. However selection of the lipases capable of performing transesterification reactions is not easy and consequently very few biodiesel producing lipases are currently available. In this work we first isolated 1,016 lipolytic microorganisms by a qualitative plate assay. In a second step, lipolytic bacteria were analyzed using a colorimetric assay to detect the transesterification activity. Thirty of the initial lipolytic strains were selected for further characterization. Phylogenetic analysis revealed that 23 of the bacterial isolates were Gram negative and 7 were Gram positive, belonging to different clades. Biofuel production was analyzed and quantified by gas chromatography and revealed that 5 of the isolates produced biofuel with yields higher than 80% at benchtop scale. Chemical and viscosity analysis of the produced biofuel revealed that it differed from biodiesel. This bacterial-derived biofuel does not require any further downstream processing and it can be used directly in engines. The freeze-dried bacterial culture supernatants could be used at least five times for biofuel production without diminishing their activity. Therefore, these 5 isolates represent excellent candidates for testing biofuel production at industrial scale. PMID:25099150

  10. Effects of lactic acid bacteria isolated from fermented mustard on lowering cholesterol

    PubMed Central

    Wang, Shu Chen; Chang, Chen Kai; Chan, Shu Chang; Shieh, Jiunn Shiuh; Chiu, Chih Kwang; Duh, Pin-Der

    2014-01-01

    Objective To evaluate the ability of lactic acid bacteria (LAB) strains isolated from fermented mustard to lower the cholesterol in vitro. Methods The ability of 50 LAB strains isolated from fermented mustard on lowering cholesterol in vitro was determined by modified o-phtshalaldehyde method. The LAB isolates were analyzed for their resistance to acid and bile salt. Strains with lowering cholesterol activity, were determined adherence to Caco-2 cells. Results Strain B0007, B0006 and B0022 assimilated more cholesterol than BCRC10474 and BCRC 17010. The isolated strains showed tolerance to pH 3.0 for 3 h despite variations in the degree of viability and bile-tolerant strains, with more than 108 CFU/mL after incubation for 24 h at 1% oxigall in MRS. In addition, strain B0007 and B0022 identified as Lactobacillus plantarum with 16S rDNA sequences were able to adhere to the Caco-2 cell lines. Conclusions These strains B0007 and B0022 may be potential functional sources for cholesterol-lowering activities as well as adhering to Caco-2 cell lines. PMID:25183271

  11. Selection and Characterization of Biofuel-Producing Environmental Bacteria Isolated from Vegetable Oil-Rich Wastes

    PubMed Central

    Escobar-Niño, Almudena; Luna, Carlos; Luna, Diego; Marcos, Ana T.; Cánovas, David; Mellado, Encarnación

    2014-01-01

    Fossil fuels are consumed so rapidly that it is expected that the planet resources will be soon exhausted. Therefore, it is imperative to develop alternative and inexpensive new technologies to produce sustainable fuels, for example biodiesel. In addition to hydrolytic and esterification reactions, lipases are capable of performing transesterification reactions useful for the production of biodiesel. However selection of the lipases capable of performing transesterification reactions is not easy and consequently very few biodiesel producing lipases are currently available. In this work we first isolated 1,016 lipolytic microorganisms by a qualitative plate assay. In a second step, lipolytic bacteria were analyzed using a colorimetric assay to detect the transesterification activity. Thirty of the initial lipolytic strains were selected for further characterization. Phylogenetic analysis revealed that 23 of the bacterial isolates were Gram negative and 7 were Gram positive, belonging to different clades. Biofuel production was analyzed and quantified by gas chromatography and revealed that 5 of the isolates produced biofuel with yields higher than 80% at benchtop scale. Chemical and viscosity analysis of the produced biofuel revealed that it differed from biodiesel. This bacterial-derived biofuel does not require any further downstream processing and it can be used directly in engines. The freeze-dried bacterial culture supernatants could be used at least five times for biofuel production without diminishing their activity. Therefore, these 5 isolates represent excellent candidates for testing biofuel production at industrial scale. PMID:25099150

  12. Isolation and characterization of bacteriophages specific to hydrogen-sulfide-producing bacteria.

    PubMed

    Gong, Chao; Heringa, Spencer; Singh, Randhir; Kim, Jinkyung; Jiang, Xiuping

    2013-01-01

    The objectives of this study were to isolate and characterize bacteriophages specific to hydrogen-sulfide-producing bacteria (SPB) from raw animal materials, and to develop a SPB-specific bacteriophage cocktail for rendering application. Meat, chicken offal, and feather samples collected from local supermarkets and rendering processing plants were used to isolate SPB (n = 142). Bacteriophages (n = 52) specific to SPB were isolated and purified from the above samples using 18 of those isolated SPB strains as hosts. The host ranges of bacteriophages against 5 selected SPB strains (Escherichia coli, Citrobacter freundii, and Hafnia alvei) were determined. Electron microscopy observation of 9 phages selected for the phage cocktail revealed that 6 phages belonged to the family of Siphoviridae and 3 belonged to the Myoviridae family. Restriction enzyme digestion analysis with endonuclease DraI detected 6 distinguished patterns among the 9 phages. Phage treatment prevented the growth of SPB for up to 10 h with multiplicity of infection ratios of 1, 10, 100, and 1000 in tryptic soy broth at 30 °C, and extended the lag phase of SPB growth for 2 h at 22 °C with multiplicities of infection of 10, 100, and 1000. These results suggest that the selected bacteriophage cocktail has a high potential for phage application to control SPB in raw animal materials destined for the rendering process.

  13. Isolation and characterization of bacteriophages specific to hydrogen-sulfide-producing bacteria.

    PubMed

    Gong, Chao; Heringa, Spencer; Singh, Randhir; Kim, Jinkyung; Jiang, Xiuping

    2013-01-01

    The objectives of this study were to isolate and characterize bacteriophages specific to hydrogen-sulfide-producing bacteria (SPB) from raw animal materials, and to develop a SPB-specific bacteriophage cocktail for rendering application. Meat, chicken offal, and feather samples collected from local supermarkets and rendering processing plants were used to isolate SPB (n = 142). Bacteriophages (n = 52) specific to SPB were isolated and purified from the above samples using 18 of those isolated SPB strains as hosts. The host ranges of bacteriophages against 5 selected SPB strains (Escherichia coli, Citrobacter freundii, and Hafnia alvei) were determined. Electron microscopy observation of 9 phages selected for the phage cocktail revealed that 6 phages belonged to the family of Siphoviridae and 3 belonged to the Myoviridae family. Restriction enzyme digestion analysis with endonuclease DraI detected 6 distinguished patterns among the 9 phages. Phage treatment prevented the growth of SPB for up to 10 h with multiplicity of infection ratios of 1, 10, 100, and 1000 in tryptic soy broth at 30 °C, and extended the lag phase of SPB growth for 2 h at 22 °C with multiplicities of infection of 10, 100, and 1000. These results suggest that the selected bacteriophage cocktail has a high potential for phage application to control SPB in raw animal materials destined for the rendering process. PMID:23391228

  14. Probiotic potential of selected lactic acid bacteria strains isolated from Brazilian kefir grains.

    PubMed

    Leite, A M O; Miguel, M A L; Peixoto, R S; Ruas-Madiedo, P; Paschoalin, V M F; Mayo, B; Delgado, S

    2015-06-01

    A total of 34 lactic acid bacteria isolates from 4 different Brazilian kefir grains were identified and characterized among a group of 150 isolates, using the ability to tolerate acidic pH and resistance to bile salts as restrictive criteria for probiotic potential. All isolates were identified by amplified ribosomal DNA restriction analysis and 16S rDNA sequencing of representative amplicons. Eighteen isolates belonged to the species Leuconostoc mesenteroides, 11 to Lactococcus lactis (of which 8 belonged to subspecies cremoris and 3 to subspecies lactis), and 5 to Lactobacillus paracasei. To exclude replicates, a molecular typing analysis was performed by combining repetitive extragenic palindromic-PCR and random amplification of polymorphic DNA techniques. Considering a threshold of 90% similarity, 32 different strains were considered. All strains showed some antagonistic activity against 4 model food pathogens. In addition, 3 Lc. lactis strains and 1 Lb. paracasei produced bacteriocin-like inhibitory substances against at least 2 indicator organisms. Moreover, 1 Lc. lactis and 2 Lb. paracasei presented good total antioxidative activity. None of these strains showed undesirable enzymatic or hemolytic activities, while proving susceptible or intrinsically resistant to a series of clinically relevant antibiotics. The Lb. paracasei strain MRS59 showed a level of adhesion to human Caco-2 epithelial cells comparable with that observed for Lactobacillus rhamnosus GG. Taken together, these properties allow the MRS59 strain to be considered a promising probiotic candidate.

  15. Decolorization of textile azo dyes by newly isolated halophilic and halotolerant bacteria.

    PubMed

    Asad, S; Amoozegar, M A; Pourbabaee, A A; Sarbolouki, M N; Dastgheib, S M M

    2007-08-01

    Studies were carried out on the decolorization of textile azo dyes by newly isolated halophilic and halotolerant bacteria. Among the 27 strains of halophilic and halotolerant bacteria isolated from effluents of textile industries, three showed remarkable ability in decolorizing the widely utilized azo dyes. Phenotypic characterization and phylogenetic analysis based on 16S rDNA sequence comparisons indicate that these strains belonged to the genus Halomonas. The three strains were able to decolorize azo dyes in a wide range of NaCl concentration (up to 20%w/v), temperature (25-40 degrees C), and pH (5-11) after 4 days of incubation in static culture. They could decolorize the mixture of dyes as well as pure dyes. These strains also readily grew in and decolorized the high concentrations of dye (5000 ppm) and could tolerate up to 10,000 ppm of the dye. UV-Vis analyses before and after decolorization and the colorless bacterial biomass after decolorization suggested that decolorization was due to biodegradation, rather than inactive surface adsorption. Analytical studies based on HPLC showed that the principal decolorization was reduction of the azo bond, followed by cleavage of the reduced bond.

  16. Aerobic biodegradation of dichloroethenes by indigenous bacteria isolated from contaminated sites in Africa.

    PubMed

    Olaniran, Ademola O; Pillay, Dorsamy; Pillay, Balakrishna

    2008-08-01

    The widespread use of tetrachloroethene (PCE) and trichloroethene (TCE) as dry cleaning solvents and degreasing agents for military and industrial applications has resulted in significant environmental contamination worldwide. Anaerobic biotransformation of PCE and TCE through reductive dechlorination frequently lead to the accumulation of dichloroethenes (DCEs), thus limiting the use of reductive dechlorination for the biotransformation of the compounds. In this study, seven bacteria indigenous to contaminated sites in Africa were characterized for DCE degradation under aerobic conditions. The specific growth rate constants of the bacterial isolates ranged between 0.346-0.552 d(-1) and 0.461-0.667 d(-1) in cis-DCE and trans-DCE, respectively. Gas chromatographic analysis revealed that up to 75% of the compounds were degraded within seven days with the degradation rate constants ranging between 0.167 and 0.198 d(-1). The two compounds were also observed to be significantly degraded, simultaneously, rather than sequentially, when present as a mixture. Phylogenetic analysis of the 16S rRNA gene sequences of the bacterial isolates revealed their identity as well as their relation to other environmentally-important bacteria. The observed biodegradation of DCEs may contribute to PCE and TCE removal at the aerobic fringe of groundwater plumes undergoing reductive dechlorination in contaminated sites. PMID:18635246

  17. Isolation of Endohyphal Bacteria from Foliar Ascomycota and In Vitro Establishment of Their Symbiotic Associations.

    PubMed

    Arendt, Kayla R; Hockett, Kevin L; Araldi-Brondolo, Sarah J; Baltrus, David A; Arnold, A Elizabeth

    2016-05-15

    Endohyphal bacteria (EHB) can influence fungal phenotypes and shape the outcomes of plant-fungal interactions. Previous work has suggested that EHB form facultative associations with many foliar fungi in the Ascomycota. These bacteria can be isolated in culture, and fungi can be cured of EHB using antibiotics. Here, we present methods for successfully introducing EHB into axenic mycelia of strains representing two classes of Ascomycota. We first establish in vitro conditions favoring reintroduction of two strains of EHB (Luteibacter sp.) into axenic cultures of their original fungal hosts, focusing on fungi isolated from healthy plant tissue as endophytes: Microdiplodia sp. (Dothideomycetes) and Pestalotiopsis sp. (Sordariomycetes). We then demonstrate that these EHB can be introduced into a novel fungal host under the same conditions, successfully transferring EHB between fungi representing different classes. Finally, we manipulate conditions to optimize reintroduction in a focal EHB-fungal association. We show that EHB infections were initiated and maintained more often under low-nutrient culture conditions and when EHB and fungal hyphae were washed with MgCl2 prior to reassociation. Our study provides new methods for experimental assessment of the effects of EHB on fungal phenotypes and shows how the identity of the fungal host and growth conditions can define the establishment of these widespread and important symbioses. PMID:26969692

  18. Characterization of unusual alkaliphilic gram-positive bacteria isolated from degraded brown alga thalluses.

    PubMed

    Ivanova, E P; Wright, J P; Lysenko, A M; Zhukova, N V; Alexeeva, Y V; Buljan, V; Kalinovskaya, N I; Nicolau, D V; Christen, R; Mikhailov, V V

    2006-01-01

    Two orange-pigmented Gram-positive, aerobic bacteria were isolated from enrichment culture during degradation of brown alga Fucus evanescens thalluses. In this work, atomic force microscopy (AFM) has been used to study the cell morphology. The non-contact mode imaging revealed unusual irregular coccoid shape of cells, possessing a single flagellum. Bacteria produced carotenoid pigments, were chemo-organotrophic, alkaliphilic and halo-tolerant growing well on nutrient media containing up to 15% NaCl. Growth temperature ranged from 5 to 45 degrees C. The DNA base compositions were 48 mol% G + C and the level of DNA similarity of two strains was conspecific (98%). A comparative phylogenetic analysis of 16S rRNA gene sequences revealed that the strain KMM 3738 tightly clustered with recently described Planococcus maritimus (99.9% 16S rRNA gene sequence similarity). DNA-DNA hybridisation experiments revealed that DNA from the KMM 3738 showed 12-15% and 16-35% of genetic relatedness with the DNA of type strains of the genera Planomicrobium and Planococcus, respectively, and 87% with DNA from Planococcus maritimus, indicating that new isolates belong to the later species. PMID:17100323

  19. Aerobic biodegradation of dichloroethenes by indigenous bacteria isolated from contaminated sites in Africa.

    PubMed

    Olaniran, Ademola O; Pillay, Dorsamy; Pillay, Balakrishna

    2008-08-01

    The widespread use of tetrachloroethene (PCE) and trichloroethene (TCE) as dry cleaning solvents and degreasing agents for military and industrial applications has resulted in significant environmental contamination worldwide. Anaerobic biotransformation of PCE and TCE through reductive dechlorination frequently lead to the accumulation of dichloroethenes (DCEs), thus limiting the use of reductive dechlorination for the biotransformation of the compounds. In this study, seven bacteria indigenous to contaminated sites in Africa were characterized for DCE degradation under aerobic conditions. The specific growth rate constants of the bacterial isolates ranged between 0.346-0.552 d(-1) and 0.461-0.667 d(-1) in cis-DCE and trans-DCE, respectively. Gas chromatographic analysis revealed that up to 75% of the compounds were degraded within seven days with the degradation rate constants ranging between 0.167 and 0.198 d(-1). The two compounds were also observed to be significantly degraded, simultaneously, rather than sequentially, when present as a mixture. Phylogenetic analysis of the 16S rRNA gene sequences of the bacterial isolates revealed their identity as well as their relation to other environmentally-important bacteria. The observed biodegradation of DCEs may contribute to PCE and TCE removal at the aerobic fringe of groundwater plumes undergoing reductive dechlorination in contaminated sites.

  20. Beneficial Bacteria Isolated from Grapevine Inner Tissues Shape Arabidopsis thaliana Roots.

    PubMed

    Baldan, Enrico; Nigris, Sebastiano; Romualdi, Chiara; D'Alessandro, Stefano; Clocchiatti, Anna; Zottini, Michela; Stevanato, Piergiorgio; Squartini, Andrea; Baldan, Barbara

    2015-01-01

    We investigated the potential plant growth-promoting traits of 377 culturable endophytic bacteria, isolated from Vitis vinifera cv. Glera, as good biofertilizer candidates in vineyard management. Endophyte ability in promoting plant growth was assessed in vitro by testing ammonia production, phosphate solubilization, indole-3-acetic acid (IAA) and IAA-like molecule biosynthesis, siderophore and lytic enzyme secretion. Many of the isolates were able to mobilize phosphate (33%), release ammonium (39%), secrete siderophores (38%) and a limited part of them synthetized IAA and IAA-like molecules (5%). Effects of each of the 377 grapevine beneficial bacteria on Arabidopsis thaliana root development were also analyzed to discern plant growth-promoting abilities (PGP) of the different strains, that often exhibit more than one PGP trait. A supervised model-based clustering analysis highlighted six different classes of PGP effects on root architecture. A. thaliana DR5::GUS plantlets, inoculated with IAA-producing endophytes, resulted in altered root growth and enhanced auxin response. Overall, the results indicate that the Glera PGP endospheric culturable microbiome could contribute, by structural root changes, to obtain water and nutrients increasing plant adaptation and survival. From the complete cultivable collection, twelve promising endophytes mainly belonging to the Bacillus but also to Micrococcus and Pantoea genera, were selected for further investigations in the grapevine host plants towards future application in sustainable management of vineyards. PMID:26473358

  1. Characteristics of Hg-resistant bacteria isolated from Minamata Bay sediment

    SciTech Connect

    Nakamura, K.; Fujisaki, T.; Tamashiro, H.

    1986-06-01

    Seventy-two strains of Hg-resistant bacteria (Pseudomonas) were isolated on agar plates containing 40 micrograms/ml of HgCl2 from Minamata Bay sediment, which was heavily polluted with mercury (45.8 micrograms/g). The minimal inhibitory concentrations (MICs) of mercurial compounds were determined for the Hg-resistant pseudomonads and 65 strains (Pseudomonas sp., Bacillus sp., Vibrio sp., and Corynebacterium sp.) isolated from Sendai Bay sediment (1 microgram/g of mercury) as control. The MICs to HgCl/sub 2/, CH/sub 3/HgCl, C/sub 2/H/sub 5/HgCl, C/sub 3/H/sub 7/HgCl, and C/sub 6/H/sub 5/HgOCOCH/sub 3/ for the Hg-resistant pseudomonads from Minamata Bay were significantly higher than those of strains from Sendai Bay. The volatilization from liquid culture containing 20 micrograms/ml of HgCl2 was observed in all of the Hg-resistant pseudomonads from Minamata Bay (70 strains). The mean loss of mercury from liquid culture was 60.4 +/- 17.3%. Further study is warranted to determine what role the Hg-resistant bacteria, particularly the Pseudomonas species, play in the mercury cycle in Minamata Bay.

  2. Beneficial Bacteria Isolated from Grapevine Inner Tissues Shape Arabidopsis thaliana Roots

    PubMed Central

    Baldan, Enrico; Nigris, Sebastiano; Romualdi, Chiara; D’Alessandro, Stefano; Clocchiatti, Anna; Zottini, Michela; Stevanato, Piergiorgio; Squartini, Andrea; Baldan, Barbara

    2015-01-01

    We investigated the potential plant growth-promoting traits of 377 culturable endophytic bacteria, isolated from Vitis vinifera cv. Glera, as good biofertilizer candidates in vineyard management. Endophyte ability in promoting plant growth was assessed in vitro by testing ammonia production, phosphate solubilization, indole-3-acetic acid (IAA) and IAA-like molecule biosynthesis, siderophore and lytic enzyme secretion. Many of the isolates were able to mobilize phosphate (33%), release ammonium (39%), secrete siderophores (38%) and a limited part of them synthetized IAA and IAA-like molecules (5%). Effects of each of the 377 grapevine beneficial bacteria on Arabidopsis thaliana root development were also analyzed to discern plant growth-promoting abilities (PGP) of the different strains, that often exhibit more than one PGP trait. A supervised model-based clustering analysis highlighted six different classes of PGP effects on root architecture. A. thaliana DR5::GUS plantlets, inoculated with IAA-producing endophytes, resulted in altered root growth and enhanced auxin response. Overall, the results indicate that the Glera PGP endospheric culturable microbiome could contribute, by structural root changes, to obtain water and nutrients increasing plant adaptation and survival. From the complete cultivable collection, twelve promising endophytes mainly belonging to the Bacillus but also to Micrococcus and Pantoea genera, were selected for further investigations in the grapevine host plants towards future application in sustainable management of vineyards. PMID:26473358

  3. Biomineralization processes of calcite induced by bacteria isolated from marine sediments

    PubMed Central

    Wei, Shiping; Cui, Hongpeng; Jiang, Zhenglong; Liu, Hao; He, Hao; Fang, Nianqiao

    2015-01-01

    Biomineralization is a known natural phenomenon associated with a wide range of bacterial species. Bacterial-induced calcium carbonate precipitation by marine isolates was investigated in this study. Three genera of ureolytic bacteria, Sporosarcina sp., Bacillus sp. and Brevundimonas sp. were observed to precipitate calcium carbonate minerals. Of these species, Sporosarcina sp. dominated the cultured isolates. B. lentus CP28 generated higher urease activity and facilitated more efficient precipitation of calcium carbonate at 3.24 ± 0.25 × 10−4 mg/cell. X-ray diffraction indicated that the dominant calcium carbonate phase was calcite. Scanning electron microscopy showed that morphologies of the minerals were dominated by cubic, rhombic and polygonal plate-like crystals. The dynamic process of microbial calcium carbonate precipitation revealed that B. lentus CP28 precipitated calcite crystals through the enzymatic hydrolysis of urea, and that when ammonium ion concentrations reached 746 mM and the pH reached 9.6, that favored calcite precipitation at a higher level of 96 mg/L. The results of this research provide evidence that a variety of marine bacteria can induce calcium carbonate precipitation, and may influence the marine carbonate cycle in natural environments. PMID:26273260

  4. Isolation and Identification of Sodium Fluoroacetate Degrading Bacteria from Caprine Rumen in Brazil

    PubMed Central

    Camboim, Expedito K. A.; Almeida, Arthur P.; Tadra-Sfeir, Michelle Z.; Junior, Felício G.; Andrade, Paulo P.; McSweeney, Chris S.; Melo, Marcia A.; Riet-Correa, Franklin

    2012-01-01

    The objective of this paper was to report the isolation of two fluoroacetate degrading bacteria from the rumen of goats. The animals were adult goats, males, crossbred, with rumen fistula, fed with hay, and native pasture. The rumen fluid was obtained through the rumen fistula and immediately was inoculated 100 μL in mineral medium added with 20 mmol L−1 sodium fluoroacetate (SF), incubated at 39°C in an orbital shaker. Pseudomonas fluorescens (strain DSM 8341) was used as positive control for fluoroacetate dehalogenase activity. Two isolates were identified by 16S rRNA gene sequencing as Pigmentiphaga kullae (ECPB08) and Ancylobacter dichloromethanicus (ECPB09). These bacteria degraded sodium fluoroacetate, releasing 20 mmol L−1 of fluoride ion after 32 hours of incubation in Brunner medium containing 20 mmol L−1 of SF. There are no previous reports of fluoroacetate dehalogenase activity for P. kullae and A. dichloromethanicus. Control measures to prevent plant intoxication, including use of fences, herbicides, or other methods of eliminating poisonous plants, have been unsuccessful to avoid poisoning by fluoroacetate containing plants in Brazil. In this way, P. kullae and A. dichloromethanicus may be used to colonize the rumen of susceptible animals to avoid intoxication by fluoroacetate containing plants. PMID:22919294

  5. Beneficial Bacteria Isolated from Grapevine Inner Tissues Shape Arabidopsis thaliana Roots.

    PubMed

    Baldan, Enrico; Nigris, Sebastiano; Romualdi, Chiara; D'Alessandro, Stefano; Clocchiatti, Anna; Zottini, Michela; Stevanato, Piergiorgio; Squartini, Andrea; Baldan, Barbara

    2015-01-01

    We investigated the potential plant growth-promoting traits of 377 culturable endophytic bacteria, isolated from Vitis vinifera cv. Glera, as good biofertilizer candidates in vineyard management. Endophyte ability in promoting plant growth was assessed in vitro by testing ammonia production, phosphate solubilization, indole-3-acetic acid (IAA) and IAA-like molecule biosynthesis, siderophore and lytic enzyme secretion. Many of the isolates were able to mobilize phosphate (33%), release ammonium (39%), secrete siderophores (38%) and a limited part of them synthetized IAA and IAA-like molecules (5%). Effects of each of the 377 grapevine beneficial bacteria on Arabidopsis thaliana root development were also analyzed to discern plant growth-promoting abilities (PGP) of the different strains, that often exhibit more than one PGP trait. A supervised model-based clustering analysis highlighted six different classes of PGP effects on root architecture. A. thaliana DR5::GUS plantlets, inoculated with IAA-producing endophytes, resulted in altered root growth and enhanced auxin response. Overall, the results indicate that the Glera PGP endospheric culturable microbiome could contribute, by structural root changes, to obtain water and nutrients increasing plant adaptation and survival. From the complete cultivable collection, twelve promising endophytes mainly belonging to the Bacillus but also to Micrococcus and Pantoea genera, were selected for further investigations in the grapevine host plants towards future application in sustainable management of vineyards.

  6. Extended-Spectrum Beta-Lactamase Bacteria From Urine Isolates in Children

    PubMed Central

    Degnan, Lisa A.; Milstone, Aaron M.; Diener-West, Marie

    2015-01-01

    OBJECTIVES: Multidrug-resistant Gram-negative bacteria, including extended-spectrum beta-lactamase (ESBL)–producing organisms, are a growing problem. The primary objective of this study was to describe the proportion of children with ESBL-producing urinary isolates at a tertiary medical center as well as these organisms' susceptibility patterns. The secondary objective was to identify the risk factors for acquiring ESBL urinary pathogens. METHODS: This retrospective study evaluated a cohort of children with ESBL urinary isolates, admitted to a tertiary children's hospital during a 6-year period. The proportion of patients with an ESBL-producing urinary isolate among all patients who grew a Gram-negative isolate is described together with the organism's susceptibility pattern. Patients with non-ESBL Gram-negative urinary organisms were used as a control group for identifying patient risk factors for ESBL. RESULTS: A total of 7.8% (29 of 370) of patients in our cohort grew Gram-negative urinary isolates with an ESBL strain. Most of the ESBL organisms isolated were sensitive to carbapenems (100% of ESBL organisms susceptible to ertapenem and 93.8% susceptible to meropenem) and amikacin (92.3% of ESBL organisms susceptible). Patients with longer hospitalization, recent antibiotic use, and recent intensive care unit admission were found to be at increased risk for ESBL organisms in the urine. CONCLUSIONS: When selecting empiric antibiotic therapy for suspected urinary tract infection in children, it may be prudent to consider the risk factors identified for acquiring an ESBL urinary pathogen. PMID:26472951

  7. Isolating and evaluating lactic acid bacteria strains for effectiveness of Leymus chinensis silage fermentation.

    PubMed

    Zhang, Q; Li, X J; Zhao, M M; Yu, Z

    2014-10-01

    Five LAB strains were evaluated using the acid production ability test, morphological observation, Gram staining, physiological, biochemical and acid tolerance tests. All five strains (LP1, LP2, LP3, LC1 and LC2) grew at pH 4·0, and LP1 grew at 15°C. Strains LP1, LP2 and LP3 were identified as Lactobacillus plantarum, whereas LC1 and LC2 were classified as Lactobacillus casei by sequencing 16S rDNA. The five isolated strains and two commercial inoculants (PS and CL) were added to native grass and Leymus chinensis (Trin.) Tzvel. for ensiling. All five isolated strains decreased the pH and ammonia nitrogen content, increased the lactic acid content and LP1, LP2 and LP3 increased the acetic content and lactic/acetic acid ratio of L. chinensis silage significantly. The five isolated strains and two commercial inoculants decreased the butyric acid content of the native grass silage. LP2 treatment had lower butyric acid content and ammonia nitrogen content than the other treatments. The five isolated strains improved the quality of L. chinensis silage. The five isolated strains and the two commercial inoculants were not effective in improving the fermentation quality of the native grass silage, but LP2 performed better comparatively. Significance and impact of the study: Leymus chinensis is an important grass in China and Russia, being the primary grass of the short grassland 'steppe' regions of central Asia. However, it has been difficult to make high-quality silage of this species because of low concentration of water-soluble carbohydrates (WSC). Isolating and evaluating lactic acid bacteria strains will be helpful for improving the silage quality of this extensively grown species. PMID:24888497

  8. Plant growth-promoting traits of biocontrol potential bacteria isolated from rice rhizosphere.

    PubMed

    Gopalakrishnan, Subramaniam; Upadhyaya, Hd; Vadlamudi, Srinivas; Humayun, Pagidi; Vidya, Meesala Sree; Alekhya, Gottumukkala; Singh, Amit; Vijayabharathi, Rajendran; Bhimineni, Ratna Kumari; Seema, Murali; Rathore, Abhishek; Rupela, Om

    2012-12-01

    Seven isolates of bacteria (SRI-156, SRI-158, SRI-178, SRI-211, SRI-229, SRI-305 and SRI-360) were earlier reported by us as having potential for biocontrol of charcoal rot of sorghum and plant growth promotion (PGP) of the plant. In the present study, the seven isolates were characterized for their physiological traits (tolerance to salinity, pH, temperature and resistance to antibiotics and fungicides) and further evaluated in the field for their PGP of rice. All the seven isolates were able to grow at pH values between 5 and 13, in NaCl concentrations of up to 8% (except SRI-156 and SRI-360), temperatures between 20 and 40°C and were resistant to ampicillin (>100 ppm; except SRI-158 and SRI-178) but sensitive (<10 ppm) to chloramphenicol, kanamycin, nalidixic acid, streptomycin (except SRI-156 and SRI-211) and tetracycline. They were tolerant to fungicides benlate and captan, except SRI-158 and SRI-178, bavistin and sensitive to thiram (except SRI-156 and SRI-211) at field application level. In the field, four of the seven isolates (SRI-158, SRI-211, SRI-229 and SRI-360) significantly enhanced the tiller numbers, stover and grain yields, total dry matter, root length, volume and dry weight over the un-inoculated control. In the rhizosphere soil at harvest, all the isolates significantly enhanced microbial biomass carbon (except SRI-156), microbial biomass nitrogen and dehydrogenase activity (up to 33%, 36% and 39%, respectively) and total N, available P and% organic carbon (up to 10%, 38% and 10%, respectively) compared to the control. This investigation further confirms that the SRI isolates have PGP properties.

  9. Destruction-free procedure for the isolation of bacteria from sputum samples for Raman spectroscopic analysis.

    PubMed

    Kloß, Sandra; Lorenz, Björn; Dees, Stefan; Labugger, Ines; Rösch, Petra; Popp, Jürgen

    2015-11-01

    Lower respiratory tract infections are the fourth leading cause of death worldwide. Here, a timely identification of the causing pathogens is crucial to the success of the treatment. Raman spectroscopy allows for quick identification of bacterial cells without the need for time-consuming cultivation steps, which is the current gold standard to detect pathogens. However, before Raman spectroscopy can be used to identify pathogens, they have to be isolated from the sample matrix, i.e., sputum in case of lower respiratory tract infections. In this study, we report an isolation protocol for single bacterial cells from sputum samples for Raman spectroscopic identification. Prior to the isolation, a liquefaction step using the proteolytic enzyme mixture Pronase E is required in order to deal with the high viscosity of sputum. The extraction of the bacteria was subsequently performed via different filtration and centrifugation steps, whereby isolation ratios between 46 and 57 % were achieved for sputa spiked with 6·10(7) to 6·10(4) CFU/mL of Staphylococcus aureus. The compatibility of such a liquefaction and isolation procedure towards a Raman spectroscopic classification was shown for five different model species, namely S. aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Klebsiella pneumoniae, and Pseudomonas aeruginosa. A classification of single-cell Raman spectra of these five species with an accuracy of 98.5 % could be achieved on the basis of a principal component analysis (PCA) followed by a linear discriminant analysis (LDA). These classification results could be validated with an independent test dataset, where 97.4 % of all spectra were identified correctly. Graphical Abstract Development of an isolation protocol of bacterial cells out of sputum samples followed by Raman spectroscopic measurement and species identification using chemometrical models. PMID:26041453

  10. Hydrogen-dependent oxygen reduction by homoacetogenic bacteria isolated from termite guts.

    PubMed

    Boga, Hamadi I; Brune, Andreas

    2003-02-01

    Although homoacetogenic bacteria are generally considered to be obligate anaerobes, they colonize the intestinal tracts of termites and other environments that are not entirely anoxic in space or time. In this study, we investigated how homoacetogenic bacteria isolated from the hindguts of various termites respond to the presence of molecular oxygen. All strains investigated formed growth bands in oxygen gradient agar tubes under a headspace of H(2)-CO(2). The position of the bands coincided with the oxic-anoxic interface and depended on the O(2) partial pressure in the headspace; the position of the bands relative to the meniscus remained stable for more than 1 month. Experiments with dense cell suspensions, performed with Clark-type O(2) and H(2) electrodes, revealed a large capacity for H(2)-dependent oxygen reduction in Sporomusa termitida and Sporomusa sp. strain TmAO3 (149 and 826 nmol min(-1) mg of protein(-1), respectively). Both strains also reduced O(2) with endogenous reductants, albeit at lower rates. Only in Acetonema longum did the basal rates exceed the H(2)-dependent rates considerably (181 versus 28 nmol min(-1) mg of protein)(-1)). Addition of organic substrates did not stimulate O(2) consumption in any of the strains. Nevertheless, reductive acetogenesis by cell suspensions of strain TmAO3 was inhibited even at the lowest O(2) fluxes, and growth in nonreduced medium occurred only after the bacteria had rendered the medium anoxic. Similar results were obtained with Acetobacterium woodii, suggesting that the results are not unique to the strains isolated from termites. We concluded that because of their tolerance to temporary exposure to O(2) at low partial pressures (up to 1.5 kPa in the case of strain TmAO3) and because of their large capacity for O(2) reduction, homoacetogens can reestablish conditions favorable for growth by actively removing oxygen from their environment.

  11. Heavy metal tolerance (Cr, Ag AND Hg) in bacteria isolated from sewage

    PubMed Central

    Lima de Silva, Agostinho A.; de Carvalho, Márcia A. Ribeiro; de Souza, Sérgio A. L; Dias, Patrícia M. Teixeira; da Silva Filho, Renato G.; de Meirelles Saramago, Carmen S.; de Melo Bento, Cleonice A.; Hofer, Ernesto

    2012-01-01

    Samples of sewage from a university hospital and a chemistry technical school were analysed for the percentage of bacterial tolerance to chromium (Cr), silver (Ag) and mercury (Hg). Additionally, we investigated the effect of these metals on pigmentation and on some enzymatic activities of the metal tolerant strains isolated, as well as antimicrobial resistance in some metal tolerant Enterobacteriaceae strains. Tolerance to Cr was observed mainly in Gram positive bacteria while in the case of Ag and Hg the tolerant bacteria were predominately Gram negative. Hg was the metal for which the percentage of tolerance was significantly higher, especially in samples from the hospital sewage (4.1%). Mercury also had the most discernible effect on color of the colonies. Considering the effect of metals on the respiratory enzymes, one strain of Ag-tolerant Bacillus sp. and one of Hg-tolerant P. aeruginosa were unable to produce oxidase in the presence of Ag and Hg, respectively, while the expression of gelatinase was largely inhibited in various Gram negative strains (66% by Cr). Drug resistance in Hg-tolerant Enterobacteriaceae strains isolated from the university hospital sewage was greater than 80%, with prevalence of multiple resistance, while the Ag-tolerant strains from the same source showed about 34% of resistance, with the predominance of mono-resistance. Our results showed that, despite the ability of metal tolerant strains to survive and grow in the presence of these elements, the interactions with these metals may result in metabolic or phisiological changes in this group of bacteria. PMID:24031994

  12. Rapid Isolation of Phenol Degrading Bacteria by Fourier Transform Infrared (FTIR) Spectroscopy.

    PubMed

    Li, Fei; Song, Wen-jun; Wei, Ji-ping; Wang, Su-ying; Liu, Chong-ji

    2015-05-01

    Phenol is an important chemical engineering material and ubiquitous in industry wastewater, its existence has become a thorny issue in many developed and developing country. More and more stringent standards for effluent all over the world with human realizing the toxicity of phenol have been announced. Many advanced biological methods are applied to industrial wastewater treatment with low cost, high efficiency and no secondary pollution, but the screening of function microorganisms is certain cumbersome process. In our study a rapid procedure devised for screening bacteria on solid medium can degrade phenol coupled with attenuated total reflection fourier transform infrared (ATR-FTIR) which is a detection method has the characteristics of efficient, fast, high fingerprint were used. Principal component analysis (PCA) is a method in common use to extract fingerprint peaks effectively, it couples with partial least squares (PLS) statistical method could establish a credible model. The model we created using PCA-PLS can reach 99. 5% of coefficient determination and validation data get 99. 4%, which shows the promising fitness and forecasting of the model. The high fitting model is used for predicting the concentration of phenol at solid medium where the bacteria were grown. The highly consistent result of two screening methods, solid cultural with ATR-FTIR detected and traditional liquid cultural detected by GC methods, suggests the former can rapid isolate the bacteria which can degrade substrates as well as traditional cumbersome liquid cultural method. Many hazardous substrates widely existed in industry wastewater, most of them has specialize fingerprint peaks detected by ATR-FTIR, thereby this detected method could be used as a rapid detection for isolation of functional microorganisms those can degrade many other toxic substrates.

  13. Heavy metal tolerance (Cr, Ag AND Hg) in bacteria isolated from sewage.

    PubMed

    Lima de Silva, Agostinho A; de Carvalho, Márcia A Ribeiro; de Souza, Sérgio A L; Dias, Patrícia M Teixeira; da Silva Filho, Renato G; de Meirelles Saramago, Carmen S; de Melo Bento, Cleonice A; Hofer, Ernesto

    2012-10-01

    Samples of sewage from a university hospital and a chemistry technical school were analysed for the percentage of bacterial tolerance to chromium (Cr), silver (Ag) and mercury (Hg). Additionally, we investigated the effect of these metals on pigmentation and on some enzymatic activities of the metal tolerant strains isolated, as well as antimicrobial resistance in some metal tolerant Enterobacteriaceae strains. Tolerance to Cr was observed mainly in Gram positive bacteria while in the case of Ag and Hg the tolerant bacteria were predominately Gram negative. Hg was the metal for which the percentage of tolerance was significantly higher, especially in samples from the hospital sewage (4.1%). Mercury also had the most discernible effect on color of the colonies. Considering the effect of metals on the respiratory enzymes, one strain of Ag-tolerant Bacillus sp. and one of Hg-tolerant P. aeruginosa were unable to produce oxidase in the presence of Ag and Hg, respectively, while the expression of gelatinase was largely inhibited in various Gram negative strains (66% by Cr). Drug resistance in Hg-tolerant Enterobacteriaceae strains isolated from the university hospital sewage was greater than 80%, with prevalence of multiple resistance, while the Ag-tolerant strains from the same source showed about 34% of resistance, with the predominance of mono-resistance. Our results showed that, despite the ability of metal tolerant strains to survive and grow in the presence of these elements, the interactions with these metals may result in metabolic or phisiological changes in this group of bacteria.

  14. Isolation, characterisation and identification of lactic acid bacteria from bushera: a Ugandan traditional fermented beverage.

    PubMed

    Muyanja, C M B K; Narvhus, J A; Treimo, J; Langsrud, T

    2003-02-15

    One hundred and thirteen strains of lactic acid bacteria (LAB) were selected from 351 isolates from 15 samples of traditionally fermented household bushera from Uganda and also from laboratory-prepared bushera. Isolates were phenotypically characterised by their ability to ferment 49 carbohydrates using API 50 CHL kits and additional biochemical tests. Coliforms, yeasts and LAB were enumerated in bushera. The pH, volatile organic compounds and organic acids were also determined. The LAB counts in household bushera varied between 7.1 and 9.4 log cfu ml(-1). The coliform counts varied between < 1 and 5.2 log cfu ml(-1). The pH of bushera ranged from 3.7 to 4.5. Ethanol (max, 0.27%) was the major volatile organic compound while lactic acid (max, 0.52%) was identified as the dominant organic acid in household bushera. The initial numbers of LAB and coliforms in laboratory-fermented bushera were similar; however, the LAB numbers increased faster during the first 24 h. LAB counts increased from 5.5 to 9.0 log cfu ml(-1) during the laboratory fermentation. Coliform counts increased from 5.9 to 7.8 log cfu ml(-1) at 24 h, but after 48 h, counts were less 4 log cfu ml(-1). Yeasts increased from 4.3 to 7.7 log cfu ml(-1) at 48 h, but thereafter decreased slightly. The pH declined from 7.0 to around 4.0. Lactic acid and ethanol increased from zero to 0.75% and 0.20%, respectively. Lactic acid bacteria isolated from household bushera belonged to Lactobacillus, Streptococcus and Enterococcus genera. Tentatively, Lactobacillus isolates were identified as Lactobacillus plantarum, L. paracasei subsp. paracasei, L. fermentum, L. brevis and L. delbrueckii subsp. delbrueckii. Streptococcus thermophilus strains were also identified in household bushera. LAB isolated from bushera produced in the laboratory belonged to five genera (Lactococcus, Leuconostoc, Lactobacillus, Weissella and Enterococcus. Eight isolates were able to produce acid from starch and were identified as Lactococcus

  15. Isolation of iron-oxidizing bacteria from corroded concretes of sewage treatment plants.

    PubMed

    Maeda, T; Negishi, A; Komoto, H; Oshima, Y; Kamimura, K; Sugio, T

    1999-01-01

    Thirty-six strains of iron-oxidizing bacteria were isolated from corroded concrete samples obtained at eight sewage treatment plants in Japan. All of the strains isolated grew autotrophically in ferrous sulfate (3.0%), elemental sulfur (1.0%) and FeS (1.0%) media (pH 1.5). Washed intact cells of the 36 isolates had activities to oxidize both ferrous iron and elemental sulfur. Strain SNA-5, a representative of the isolated strains, was a gram-negative, rod-shaped bacterium (0.5-0.6x0.9-1.5 microm). The mean G+C content of its DNA was 55.9 mol%. The pH and temperature optima for growth were 1.5 and 30 degrees C, and the bacterium had activity to assimilate 14CO2 into the cells when ferrous iron or elemental sulfur was used as a sole source of energy. These results suggest that SNA-5 is Thiobacillus ferrooxidans strain. The pHs and numbers of iron-oxidizing bacteria in corroded concrete samples obtained by boring to depths of 0-1, 1-3, and 3-5 cm below the concrete surface were respectively 1.4, 1.7, and 2.0, and 1.2 x 10(8), 5 x 10(7), and 5 x 10(6) cells/g concrete. The degree of corrosion in the sample obtained nearest to the surface was more severe than in the deeper samples. The findings indicated that the levels of acidification and corrosion of the concrete structure corresponded with the number of iron-oxidizing bacteria in a concrete sample. Sulfuric acid produced by the chemolithoautotrophic sulfur-oxidizing bacterium Thiobacillus thiooxidansis known to induce concrete corrosion. Since not only T. thiooxidans but also T. ferrooxidans can oxidize reduced sulfur compounds and produce sulfuric acid, the results strongly suggest that T. ferrooxidans as well as T. thiooxidans is involved in concrete corrosion. PMID:16232615

  16. Isolation of iron-oxidizing bacteria from corroded concretes of sewage treatment plants.

    PubMed

    Maeda, T; Negishi, A; Komoto, H; Oshima, Y; Kamimura, K; Sugio, T

    1999-01-01

    Thirty-six strains of iron-oxidizing bacteria were isolated from corroded concrete samples obtained at eight sewage treatment plants in Japan. All of the strains isolated grew autotrophically in ferrous sulfate (3.0%), elemental sulfur (1.0%) and FeS (1.0%) media (pH 1.5). Washed intact cells of the 36 isolates had activities to oxidize both ferrous iron and elemental sulfur. Strain SNA-5, a representative of the isolated strains, was a gram-negative, rod-shaped bacterium (0.5-0.6x0.9-1.5 microm). The mean G+C content of its DNA was 55.9 mol%. The pH and temperature optima for growth were 1.5 and 30 degrees C, and the bacterium had activity to assimilate 14CO2 into the cells when ferrous iron or elemental sulfur was used as a sole source of energy. These results suggest that SNA-5 is Thiobacillus ferrooxidans strain. The pHs and numbers of iron-oxidizing bacteria in corroded concrete samples obtained by boring to depths of 0-1, 1-3, and 3-5 cm below the concrete surface were respectively 1.4, 1.7, and 2.0, and 1.2 x 10(8), 5 x 10(7), and 5 x 10(6) cells/g concrete. The degree of corrosion in the sample obtained nearest to the surface was more severe than in the deeper samples. The findings indicated that the levels of acidification and corrosion of the concrete structure corresponded with the number of iron-oxidizing bacteria in a concrete sample. Sulfuric acid produced by the chemolithoautotrophic sulfur-oxidizing bacterium Thiobacillus thiooxidansis known to induce concrete corrosion. Since not only T. thiooxidans but also T. ferrooxidans can oxidize reduced sulfur compounds and produce sulfuric acid, the results strongly suggest that T. ferrooxidans as well as T. thiooxidans is involved in concrete corrosion.

  17. Identification of effective Pb resistant bacteria isolated from Lens culinaris growing in lead contaminated soils.

    PubMed

    Jebara, Salwa Harzalli; Abdelkerim, Souhir; Fatnassi, Imen Challougui; Chiboub, Manel; Saadani, Omar; Jebara, Moez

    2015-03-01

    Soil bacteria are a new phytoremediation system for the removal of heavy metals from soils. In this study, fifteen soil bacteria were isolated from root nodules of lentil growing in heavy metals contaminated soils, particularly by lead. Molecular characterization of the collection showed a large diversity, including Agrobacterium tumefaciens, Rahnella aquatilis, Pseudomonas, and Rhizobium sp. These soil bacteria had a wide range of tolerance to heavy metals. Among them, strains of A. tumefaciens and R. aquatilis tolerated up to 3.35 mM Pb; whereas Pseudomonas tolerated up to 3.24 mM Pb. The inoculation of lentil grown hydroponically with inoculums formed by these efficient and Pb resistant bacteria enhanced plant biomass. The treatment of this symbiosis by 1 mM Pb for 10 days or by 2 mM Pb for 3 days demonstrated that lentil had Pb accumulation capacity and can be considered a Pb accumulator plant, elsewhere, roots accumulated more Pb than shoots, and the inoculation decreased the Pb up take by the plants, suggesting that this symbiosis should be investigated for use in phytostabilization of Pb-contaminated soils. At the same time, a modulation in the antioxidant enzyme activity and a specific duration was required for the induction of the superoxide dismutase (SOD), peroxidase (POX), and ascorbate peroxidase (APX) response and to adapt to Pb stress. These results suggested that these enzymes may be involved in the main mechanism of antioxidative defense in lentil exposed to Pb oxidative stress. PMID:24740715

  18. Antimicrobial susceptibility of clinically isolated anaerobic bacteria in a University Hospital Centre Split, Croatia in 2013.

    PubMed

    Novak, Anita; Rubic, Zana; Dogas, Varja; Goic-Barisic, Ivana; Radic, Marina; Tonkic, Marija

    2015-02-01

    Anaerobic bacteria play a significant role in many endogenous polymicrobial infections. Since antimicrobial resistance among anaerobes has increased worldwide, it is useful to provide local susceptibility data to guide empirical therapy. The present study reports recent data on the susceptibility of clinically relevant anaerobes in a University Hospital Centre (UHC) Split, Croatia. A total of 63 Gram-negative and 59 Gram-positive anaerobic clinical isolates from various body sites were consecutively collected from January to December 2013. Antimicrobial susceptibility testing was performed using standardized methods and interpreted using EUCAST criteria. Patient's clinical and demographic data were recorded by clinical microbiologist. Among 35 isolates of Bacteroides spp., 97.1% were resistant to penicillin (PCN), 5.7% to amoxicillin/clavulanic acid (AMC), 8.6% to piperacillin/tazobactam (TZP), 29.0% to clindamycin (CLI) and 2.9% to metronidazole (MZ). Percentages of susceptible strains to imipenem (IPM), meropenem (MEM) and ertapenem (ETP) were 94.3. Resistance of other Gram-negative bacilli was 76.0% to PCN, 8.0% to AMC, 12.0% to TZP, 28.0% to CLI and 8% to MZ. All other Gram-negative strains were fully susceptible to MEM and ETP, while 96.0% were susceptible to IPM. Clostridium spp. isolates were 100% susceptible to all tested antibiotics except to CLI (two of four tested isolates were resistant). Propionibacterium spp. showed resistance to CLI in 4.3%, while 100% were resistant to MZ. Among other Gram-positive bacilli, 18.2% were resistant to PCN, 9.1% to CLI and 54.5% to MZ, while 81.8% of isolates were susceptible to carbapenems. Gram-positive cocci were 100% susceptible to all tested antimicrobials except to MZ, where 28.6% of resistant strains were recorded. Abdomen was the most common source of isolates (82.5%). The most prevalent types of infection were abscess (22.1%), sepsis (14.8%), appendicitis (13.9%) and peritonitis (6.6%). Twenty four patients (19

  19. Antimicrobial susceptibility of clinically isolated anaerobic bacteria in a University Hospital Centre Split, Croatia in 2013.

    PubMed

    Novak, Anita; Rubic, Zana; Dogas, Varja; Goic-Barisic, Ivana; Radic, Marina; Tonkic, Marija

    2015-02-01

    Anaerobic bacteria play a significant role in many endogenous polymicrobial infections. Since antimicrobial resistance among anaerobes has increased worldwide, it is useful to provide local susceptibility data to guide empirical therapy. The present study reports recent data on the susceptibility of clinically relevant anaerobes in a University Hospital Centre (UHC) Split, Croatia. A total of 63 Gram-negative and 59 Gram-positive anaerobic clinical isolates from various body sites were consecutively collected from January to December 2013. Antimicrobial susceptibility testing was performed using standardized methods and interpreted using EUCAST criteria. Patient's clinical and demographic data were recorded by clinical microbiologist. Among 35 isolates of Bacteroides spp., 97.1% were resistant to penicillin (PCN), 5.7% to amoxicillin/clavulanic acid (AMC), 8.6% to piperacillin/tazobactam (TZP), 29.0% to clindamycin (CLI) and 2.9% to metronidazole (MZ). Percentages of susceptible strains to imipenem (IPM), meropenem (MEM) and ertapenem (ETP) were 94.3. Resistance of other Gram-negative bacilli was 76.0% to PCN, 8.0% to AMC, 12.0% to TZP, 28.0% to CLI and 8% to MZ. All other Gram-negative strains were fully susceptible to MEM and ETP, while 96.0% were susceptible to IPM. Clostridium spp. isolates were 100% susceptible to all tested antibiotics except to CLI (two of four tested isolates were resistant). Propionibacterium spp. showed resistance to CLI in 4.3%, while 100% were resistant to MZ. Among other Gram-positive bacilli, 18.2% were resistant to PCN, 9.1% to CLI and 54.5% to MZ, while 81.8% of isolates were susceptible to carbapenems. Gram-positive cocci were 100% susceptible to all tested antimicrobials except to MZ, where 28.6% of resistant strains were recorded. Abdomen was the most common source of isolates (82.5%). The most prevalent types of infection were abscess (22.1%), sepsis (14.8%), appendicitis (13.9%) and peritonitis (6.6%). Twenty four patients (19

  20. Analysis of antibiotic resistance in bacteria isolated from the surface microlayer and underlying water of an estuarine environment.

    PubMed

    Azevedo, Juliana S N; Araújo, Susana; Oliveira, Cláudia S; Correia, António; Henriques, Isabel

    2013-02-01

    We compared the prevalence of cultivable antibiotic-resistant bacteria and resistance genes in the surface microlayer (SML) and underlying waters (UW) of an estuary. Prevalence of resistant bacteria was determined in antibiotic-supplemented agar. Bacterial isolates from the UW (n=91) and SML (n=80), selected in media without antibiotic, were characterized concerning susceptibility against nine antibiotics. The presence of genes bla(TEM), bla(OXA-B), bla(SHV), bla(IMP), tet(A), tet(B), tet(E), tet(M), cat, sul1, sul2, sul3, aadA, IntI1, IntI2, and IntI3 was assessed by PCR. The variable regions of integrons were sequenced. Ampicillin- and streptomycin-resistant bacteria were significantly more prevalent in SML. Resistance levels among the bacterial collections were generally low, preventing detection of significant differences between SML and UW. The tet(E) gene was detected in two Aeromonas isolates and tet(M) was detected in a Pseudomonas isolate. Gene sul1 was amplified from three Aeromonas isolates. Prevalence of intI genes was 2.11%. Cassette arrays contained genes encoding resistance to aminoglycosides and chloramphenicol. A higher prevalence of antibiotic-resistant bacteria in the SML, although only detectable when bacteria were selected in antibiotic-supplemented agar, suggests that SML conditions select for antibiotic resistance. Results also showed that antibiotic resistance was uncommon among estuarine bacteria and the resistance mechanisms are probably predominantly intrinsic.

  1. Low-temperature isolation of disease-suppressive bacteria and characterization of a distinctive group of pseudomonads.

    PubMed

    Johansson, P Maria; Wright, Sandra A I

    2003-11-01

    The influence of environmental factors during isolation on the composition of potential biocontrol isolates is largely unknown. Bacterial isolates that efficiently suppressed wheat seedling blight caused by Fusarium culmorum were found by isolating psychrotrophic, root-associated bacteria and by screening them in a bioassay that mimicked field conditions. The impact of individual isolation factors on the disease-suppressive index (DSI) of almost 600 isolates was analyzed. The bacteria originated from 135 samples from 62 sites in Sweden and Switzerland. The isolation factors that increased the probability of finding isolates with high DSIs were sampling from arable land, Swiss origin of samples, and origination of isolates from plants belonging to the family Brassicaceae. The colony morphology of the isolates was characterized and compared to DSIs, which led to identification of a uniform morphological group containing 57 highly disease-suppressive isolates. Isolates in this group were identified as Pseudomonas sp.; they were fluorescent on King's medium B and had characteristic crystalline structures in their colonies. These isolates were morphologically similar to seven strains that had previously been selected for suppression of barley net blotch caused by Drechslera teres. Members of this morphological group grow at 1.5 degrees C and produce an antifungal polyketide (2,3-deepoxy-2,3-didehydrorhizoxin [DDR]). They have similar two-dimensional polyacrylamide gel electrophoresis protein profiles, phenotypic characteristics, and in vitro inhibition spectra of pathogens. In summary, in this paper we describe some isolation factors that are important for obtaining disease-suppressive bacteria in our system, and we describe a novel group of biocontrol pseudomonads.

  2. Low-Temperature Isolation of Disease-Suppressive Bacteria and Characterization of a Distinctive Group of Pseudomonads

    PubMed Central

    Johansson, P. Maria; Wright, Sandra A. I.

    2003-01-01

    The influence of environmental factors during isolation on the composition of potential biocontrol isolates is largely unknown. Bacterial isolates that efficiently suppressed wheat seedling blight caused by Fusarium culmorum were found by isolating psychrotrophic, root-associated bacteria and by screening them in a bioassay that mimicked field conditions. The impact of individual isolation factors on the disease-suppressive index (DSI) of almost 600 isolates was analyzed. The bacteria originated from 135 samples from 62 sites in Sweden and Switzerland. The isolation factors that increased the probability of finding isolates with high DSIs were sampling from arable land, Swiss origin of samples, and origination of isolates from plants belonging to the family Brassicaceae. The colony morphology of the isolates was characterized and compared to DSIs, which led to identification of a uniform morphological group containing 57 highly disease-suppressive isolates. Isolates in this group were identified as Pseudomonas sp.; they were fluorescent on King's medium B and had characteristic crystalline structures in their colonies. These isolates were morphologically similar to seven strains that had previously been selected for suppression of barley net blotch caused by Drechslera teres. Members of this morphological group grow at 1.5°C and produce an antifungal polyketide (2,3-deepoxy-2,3-didehydrorhizoxin [DDR]). They have similar two-dimensional polyacrylamide gel electrophoresis protein profiles, phenotypic characteristics, and in vitro inhibition spectra of pathogens. In summary, in this paper we describe some isolation factors that are important for obtaining disease-suppressive bacteria in our system, and we describe a novel group of biocontrol pseudomonads. PMID:14602601

  3. Phytochemical, toxicological and antimicrobial evaluation of lawsonia inermis extracts against clinical isolates of pathogenic bacteria

    PubMed Central

    2013-01-01

    Background The emerging resistance of pathogen against the currently available antimicrobial agents demands the search of new antimicrobial agents. The use of medicinal plants as natural substitute is the paramount area of research to overwhelm the drug resistance of infectious agents. Scientists have not made enough effort on the evaluation of safety of medicinal plant yet. Methods In the present study antimicrobial activity of Lawsonia inermis is investigated against clinical isolates of seven bacteria including four Gram negative (Escherichia coli, Salmonella typhi, Klebsiella spp., Shigella sonnei) and three Gram positive (Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis) using disc diffusion method. Four types of Lawsonia inermis extracts were prepared using methanol, chloroform, acetone and water as extraction solvents, while DMSO (Dimethyl sulfoxide) and water as dissolution solvents. The rate and extent of bacterial killing was estimated by time-kill kinetic assay at 1× MIC of each bacterial isolate. The overall safety of Lawsonia inermis extracts was assessed in mice. Results Lawsonia inermis displayed noteworthy antimicrobial activity against both gram positive and gram negative bacterial strains used in the study. The minimum value of MIC for different bacterial strains ranged from 2.31 mg/ml to 9.27 mg/ml. At 1x MIC of each bacterial isolate, 3log10 decrease in CFU was recorded after 6 hours of drug exposure and no growth was observed in almost all tested bacteria after 24 hours of exposure. No sign of toxidrome were observed during in vivo toxicity evaluation in mice at 300 mg/kg concentration. Conclusion In conclusion, the present study provides the scientific rational for medicinal use of Lawsonia inermis. The use of Lawsonia inermis extracts is of great significance as substitute antimicrobial agent in therapeutics. PMID:24289297

  4. Characterization of boron tolerant bacteria isolated from a fly ash dumping site for bacterial boron remediation.

    PubMed

    Edward Raja, Chellaiah; Omine, Kiyoshi

    2013-08-01

    Boron is an essential micronutrient for plants, but can above certain concentrations be toxic to living organisms. A major environmental concern is the removal of boron from contaminated water and fly ash. For this purpose, the samples were collected from a fly ash dumping site, Nagasaki prefecture, Japan. The chemical characteristics and heavy metal concentration of the samples were performed by X-ray fluorescent analysis and leaching test. For bacterial analysis, samples were collected in sterile plastic sheets and isolation was carried out by serial dilution method. The boron tolerant isolates that showed values of maximum inhibitory concentration toward boron ranging from 100 to 260 mM level were screened. Based on 16S rRNA sequencing and phylogenetic analysis, the isolates were most closely related to the genera Bacillus, Lysinibacillus, Microbacterium and Ralstonia. The boron tolerance of these strains was also associated with resistant to several heavy metals, such as As (III), Cr (VI), Cd, Cu, Pb, Ni, Se (III) and Zn. Indeed, these strains were arsenic oxidizing bacteria confirmed by silver nitrate test. These strains exhibited their salt resistances ranging from 4 to 15 % were determined in Trypticase soy agar medium. The boron tolerant strains were capable of removing 0.1-2.0 and 2.7-3.7 mg l(-1) boron from the medium and fly ash at 168 h. Thus, we have successfully identified the boron tolerant and removal bacteria from a fly ash dumping site for boron remediation. PMID:23212536

  5. Antagonistic Characteristics Against Food-borne Pathogenic Bacteria of Lactic Acid Bacteria and Bifidobacteria Isolated from Feces of Healthy Thai Infants

    PubMed Central

    Uraipan, Supansa; Hongpattarakere, Tipparat

    2015-01-01

    Background: Food-borne pathogens are among the most significant problems in maintaining the health of people. Many probiotics have been widely reported to alleviate and protect against gastrointestinal infections through antibacterial secretion. However, the majority of them cannot always play antagonistic roles under gut conditions. Probiotic bacteria of human origin must possess other protective mechanisms to survive, out-compete intestinal flora and to successfully establish in their new host at a significant level. Objectives: Probiotic characteristics of Lactic Acid Bacteria (LAB) and bifidobacteria isolated from the feces of Thai infants were primarily investigated in terms of gastric acid and bile resistances, antibacterial activity and mucin adhesion ability. Antagonistic interaction through secretion of antibacterial compounds and competitive exclusion against food-borne pathogens were also evaluated. Materials and Methods: Culturable LAB and bifidobacteria were isolated from feces of Thai infants. Their ability to withstand gastric acid and bile were then evaluated. Acid and bile salt tolerant LAB and bifidobacteria were identified. They were then further assessed according to their antagonistic interactions through antibacterial secretion, mucin adhesion and competitive mucin adhesion against various food-borne pathogenic bacteria. Results: Gastric acid and bile tolerant LAB and bifidobacteria isolated from healthy infant feces were identified and selected according to their antagonistic interaction against various food-borne pathogenic bacteria. These antagonistic probiotics included four strains of Lactobacillus rhamnosus, two strains of L. casei, five strains of L. plantarum, two strains of Bifidobacterium longum subsp. longum and three strains of B. bifidum. All strains of the selected LAB inhibited all pathogenic bacteria tested through antibacterial secretion, while bifidobacteria showed high level of competitive exclusion against the pathogenic

  6. Multiple antibiotic resistance of heterotrophic bacteria isolated from Siberian lakes subjected to differing degrees of anthropogenic impact.

    PubMed

    Lobova, Tatiana I; Feil, Edward J; Popova, Lyudmila Yu

    2011-12-01

    The antibiotic resistance profiles of 150 heterotrophic bacterial isolates recovered from two lakes in Southern Siberia was determined to examine the effect of anthropogenic disturbance on aquatic ecosystems. Resistance was detected in at least one strain for seven of the eight antibiotics tested, the exception being amikacin. Resistance to antibiotics predominated in the areas of the lakes likely to be under highest anthropogenic disturbance. Resistance was more frequently observed among isolates recovered from within the proximity to a tourist resort (Lake Shira; 63% of bacteria with multiple antibiotic resistance (MAR) in the resort part), or the shore line (Lake Shunet; 100% of bacteria with MAR) than among isolates from the center of each lake; 42.5% of bacteria with MAR from Lake Shira and 25%/75% of bacteria are resistant to three/four antibiotics consequently from Lake Shunet. Plasmid profiles were determined from a sample of 37 multiply resistant bacteria, and between one and four plasmids were isolated from each isolate; the plasmids ranged in size from 2.3 to 23.1 kb. These observations are consistent with anthropogenic disturbance playing one of the key roles in the dissemination of antibiotic resistance in the aquatic ecosystems.

  7. Antimicrobial Resistance and Resistance Genes in Aerobic Bacteria Isolated from Pork at Slaughter.

    PubMed

    Li, Lili; Heidemann Olsen, Rikke; Ye, Lei; Yan, He; Nie, Qing; Meng, Hecheng; Shi, Lei

    2016-04-01

    The aim of this study was to investigate the phenotypic and genotypic antimicrobial resistance, integrons, and transferability of resistance markers in 243 aerobic bacteria recovered from pork at slaughter in the People's Republic of China. The organisms belonged to 22 genera of gram-negative bacteria (92.2%) and gram-positive bacteria (7.8%). High levels of resistance were detected to tetracycline, trimethoprim-sulfamethoxazole, and ampicillin (36.2 to 54.3%), and lower levels were detected to nitrofurantoin, cefotaxime, gentamicin, ciprofloxacin, and chloramphenicol (7.8 to 29.2%). Across species, genes conferring antimicrobial resistance were observed with the following frequencies: blaTEM, 40.7%; blaCMY-2, 15.2%; blaCTX-M, 11.5%; sul2, 27.2%; sul1, 14.4%; tet(A), 5.4%; tet(L), 5.4%; tet(M), 5.0%; tet(E), 3.7%; tet(C), 3.3%; tet(S), 2.5%; and tet(K), 0.8%. Various antimicrobial resistance genes were found in new carriers: blaTEM in Lactococcus garvieae, Myroides odoratimimus, Aeromonas hydrophila, Staphylococcus sciuri, Raoultella terrigena, Macrococcus caseolyticus, Acinetobacter ursingii, Sphingobacterium sp., and Oceanobacillus sp.; blaCMY-2 in Lactococcus lactis, Klebsiella oxytoca, Serratia marcescens, Acinetobacter baumannii, and Myroides phaeus; tet(L) in M. caseolyticus; sul1 in Vibrio cincinnatiensis; sul2 in Acinetobacter bereziniae, Acinetobacter johnsonii, and V. cincinnatiensis; and the class 1 integron and gene cassette aadA2 in V. cincinnatiensis. Approximately 6.6% of isolates contained class 1 integrons, and one isolate harbored class 2 integrons. Plasmid associated intI1 and androgen receptor- encoding genes were transferred into Escherichia coli J53 and E. coli DH5α by conjugation and transformation experiments, respectively. Our study highlights the importance of aerobic bacteria from pork as reservoirs for antimicrobial resistance genes and mobile genetic elements that can readily be transferred intra- and interspecies. PMID:27052863

  8. Halotolerant and halophilic histamine-forming bacteria isolated during the ripening of salted anchovies (Engraulis encrasicholus).

    PubMed

    Hernández-Herrero, M M; Roig-Sagués, A X; Rodríguez-Jerez, J J; Mora-Ventura, M T

    1999-05-01

    This study was performed to investigate halotolerant and halophilic histamine-producing bacteria isolated during the ripening of salted anchovies. Of the isolates obtained during the ripening of anchovies, 1.37% showed histamine-forming activity, most of them (70%) belonging to the Staphylococcus genus. S. epidermidis showed a powerful histamine-forming activity, producing more than 1,000 microg/ml in the presence of 3% and 10% NaCl. Another powerful histamine-producing bacterium isolated during the ripening of salted anchovies was S. capitis. It was able to produce about 400 microg/ml of histamine in 10% NaCl under experimental conditions. Most of these species might be expected to be found as a result of contamination of fish during capture and subsequent unhygienic handling. However, no increase in histamine content was found in any batches through the ripening process. Histamine content always was acceptable in accordance with the maximum allowable levels of histamine fixed by the Spanish and European Union regulations.

  9. Effect of neem extract against the bacteria isolated from marine fish.

    PubMed

    Dhayanithi, N B; Kumar, T T Ajith; Kathiresan, K

    2010-07-01

    Marine ornamental fishes are exceedingly valuable due to their high demand in domestic and international markets. There is a growing global interest to rear the fishes in captivity. But problem due to bacteria and fungi are the major hitch in captive condition. Since, the use of antibiotics is banned, an attempt was made to ascertain in vitro assay of the neem leaves extract against the bacterial pathogens isolated from infected fishes. Bacterial strains isolated from infected regions of the clown fishes Amphiprion sebae and A. ocellaris were identified as Aeromonas hydrophila, Enterobacter sp., E. coli, Pseudomonas aeruginosa, Proteus sp., Streptococcus sp., Vibrio cholerae, V. alginolyticus, V. parahaemolyticus and Yersinia enterocolitica. Ethanol and methanol extracts were highly inhibitory to the bacterial isolates when compared to other solvents. Ethanol extracts exhibited low minimum inhibitory concentration (75-250 microg ml(-1)) as compared to other extracts. The present finding revealed that the neem leaf extract significantly reduces the bacterial pathogens and their infection in marine ornamental fishes.

  10. Medium Without Rumen Fluid for Nonselective Enumeration and Isolation of Rumen Bacteria

    PubMed Central

    Caldwell, Daniel R.; Bryant, Marvin P.

    1966-01-01

    Colony counts which approximated those in a habitat-simulating, rumen fluid-agar medium (RFM) were obtained in medium 10, a medium identical to the RFM except for the replacement of rumen fluid with 1.5 × 10-6m hemin, 0.2% Trypticase, 0.05% yeast extract, and a 6.6 × 10-2m volatile fatty acid mixture qualitatively and quantitatively similar to that in rumen fluid. Single deletion of Trypticase, yeast extract, or the volatile fatty acid mixture from medium 10 significantly reduced colony counts. Colony counts were also reduced when medium 10 was modified to contain higher concentrations of Trypticase or volatile fatty acids. Significant differences were found between colony counts obtained from diluted rumen contents of animals fed a cracked corn-urea diet, and the colony counts obtained from animals fed either a cracked corn-soyean oil meal or an alfalfa hay-grain diet. Qualitative differences were found between the predominant bacterial strains isolated from rumen contents of animals fed cracked corn diets and strains isolated from animals fed alfalfa hay-grain. Regardless of differences in the predominant flora associated with diet, medium 10 and the RFM supported growth of similar bacterial populations. The results show that medium 10 is suitable for enumeration and isolation of many predominant rumen bacteria. PMID:5970467

  11. Determinants encoding resistance to several heavy metals in newly isolated copper-resistant bacteria

    SciTech Connect

    Dressler, C.; Kues, U.; Nies, D.H.; Friedrich, B. )

    1991-11-01

    Three copper-resistant, gram-negative bacteria were isolated and characterized. Of the three strains, Alcaligenes dentrificans AH tolerated the highest copper concentration (MIC = 4 mM CuSO{sub 4}). All three strains showed various levels of resistance to other metal ions. A. denitrificans AH contains sequences which cross-hybridized with the mer (mercury resistance) determinant of Tn21 and the czc (cobalt, zinc, and cadmium resistance), cnr (cobalt and nickel resistance), and chr (chromate resistance) determinants of A. eutrophus CH34. DNA-DNA hybridization with probes prepared from A. eutrophus CH34 and Tn21 revealed the presence of chr-, cnr-, and mer-like sequences on the 200-kb plasmid pHG27 and of czc, cnr, and mer homologs located on the chromosomes. The second strain, classified as Alcaligenes sp. strain PW, carries czc, cnr, and mer homologs on the 240-kb plasmid pHG29-c and chr determinant on the 290-kb plasmid pHG29-a; a third plasmid, the 260-kb large plasmid pHG29-b, is cryptic. In contrast to the Alcaligenes strains, which were isolated from metal-contaminated water, Pseudomonas paucimobilis CD was isolated from the air. This strain harbors two cryptic plasmids: the 210-kb large plasmid pHG28-a and the 40-kb plasmid pHG28-b. Southern analysis revealed no homology between the metal ion resistance determinants of A. eutrophus CH34 and P. paucimonilis CD.

  12. Isolation of Cellulose-Degrading Bacteria and Determination of Their Cellulolytic Potential

    PubMed Central

    Gupta, Pratima; Samant, Kalpana; Sahu, Avinash

    2012-01-01

    Eight isolates of cellulose-degrading bacteria (CDB) were isolated from four different invertebrates (termite, snail, caterpillar, and bookworm) by enriching the basal culture medium with filter paper as substrate for cellulose degradation. To indicate the cellulase activity of the organisms, diameter of clear zone around the colony and hydrolytic value on cellulose Congo Red agar media were measured. CDB 8 and CDB 10 exhibited the maximum zone of clearance around the colony with diameter of 45 and 50 mm and with the hydrolytic value of 9 and 9.8, respectively. The enzyme assays for two enzymes, filter paper cellulase (FPC), and cellulase (endoglucanase), were examined by methods recommended by the International Union of Pure and Applied Chemistry (IUPAC). The extracellular cellulase activities ranged from 0.012 to 0.196 IU/mL for FPC and 0.162 to 0.400 IU/mL for endoglucanase assay. All the cultures were also further tested for their capacity to degrade filter paper by gravimetric method. The maximum filter paper degradation percentage was estimated to be 65.7 for CDB 8. Selected bacterial isolates CDB 2, 7, 8, and 10 were co-cultured with Saccharomyces cerevisiae for simultaneous saccharification and fermentation. Ethanol production was positively tested after five days of incubation with acidified potassium dichromate. PMID:22315612

  13. Halotolerant and halophilic histamine-forming bacteria isolated during the ripening of salted anchovies (Engraulis encrasicholus).

    PubMed

    Hernández-Herrero, M M; Roig-Sagués, A X; Rodríguez-Jerez, J J; Mora-Ventura, M T

    1999-05-01

    This study was performed to investigate halotolerant and halophilic histamine-producing bacteria isolated during the ripening of salted anchovies. Of the isolates obtained during the ripening of anchovies, 1.37% showed histamine-forming activity, most of them (70%) belonging to the Staphylococcus genus. S. epidermidis showed a powerful histamine-forming activity, producing more than 1,000 microg/ml in the presence of 3% and 10% NaCl. Another powerful histamine-producing bacterium isolated during the ripening of salted anchovies was S. capitis. It was able to produce about 400 microg/ml of histamine in 10% NaCl under experimental conditions. Most of these species might be expected to be found as a result of contamination of fish during capture and subsequent unhygienic handling. However, no increase in histamine content was found in any batches through the ripening process. Histamine content always was acceptable in accordance with the maximum allowable levels of histamine fixed by the Spanish and European Union regulations. PMID:10340672

  14. Isolation and Characterization of a New Thermoalkalophilic Lipase from Soil Bacteria.

    PubMed

    Rabbani, Mohammad; Shafiee, Fatemeh; Shayegh, Zahra; MirMohammadSadeghi, Hamid; Samsam Shariat, Ziaedin; Etemadifar, Zahra; Moazen, Fatemeh

    2015-01-01

    Lipases are diversified enzymes in their properties and substrate specificity, which make them attractive tools for various industrial applications. In this study, an alkalinethermostable lipase producing bacteria were isolated from soil of different regions of Isfahan province (Iran) and its lipase was purified by ammonium sulfate precipitation and ion exchange chromatography. To select a thermoalkalophil lipase producing bacterium, Rhodamine B and Horikoshi media were used and the strain that can grow at 45° Cwas selected. The isolated strain was identified using microbial and biochemical tests. One strain showed an orange colored zone on plate and grew on Horikoshi plate. Microbial and biochemical tests showed that the isolated strain was Bacillus subtilis, a Gram positive rod. In PCR, an expected band was obtained with about 371 bp. The activity of the purified lipase was 10.2 folds that of the standard enzyme using ammonium sulfate precipitation and ion exchange chromatography. The molecular weight of lipase determined by SDS-PAGE electrophoresis, was 21 and 35 KDa. Existence of two bands in SDS-PAGE electrophoresis and low amount of obtained purified enzyme highlights the necessity of optimization of purification and concentrating process. PMID:26330879

  15. Antibiofilm activity of biosurfactant producing coral associated bacteria isolated from gulf of mannar.

    PubMed

    Padmavathi, Alwar Ramanujam; Pandian, Shunmugiah Karutha

    2014-12-01

    Coral Associated Bacteria (CAB) (N = 22) isolated from the mucus of the coral Acropora digitifera were screened for biosurfactants using classical screening methods; hemolysis test, lipase production, oil displacement, drop collapse test and emulsifying activity. Six CAB (U7, U9, U10, U13, U14, and U16) were found to produce biosurfactants and were identified by 16S ribosomal RNA gene sequencing as Providencia rettgeri, Psychrobacter sp., Bacillus flexus, Bacillus anthracis, Psychrobacter sp., and Bacillus pumilus respectively. Their cell surface hydrophobicity was determined by Microbial adhesion to hydrocarbon assay and the biosurfactants produced were extracted and characterized by Fourier Transform Infrared spectroscopy. Since the biosurfactants are known for their surface modifying capabilities, antibiofilm activity of positive isolates was evaluated against biofilm forming Pseudomonas aeruginosa ATCC10145. Stability of the active principle exhibiting antibiofilm activity was tested through various temperature treatments ranging from 60 to 100 °C and Proteinase K treatment. CAB isolates U7 and U9 exhibited stable antibiofilm activity even after exposure to higher temperatures which is promising for the development of novel antifouling agents for diverse industrial applications. Further, this is the first report on biosurfactant production by a coral symbiont. PMID:25320434

  16. Novel Thermo-Acidophilic Bacteria Isolated from Geothermal Sites in Yellowstone National Park: Physiological and Phylogenetic Characteristics

    SciTech Connect

    D. B. Johnson; N. Okibe; F. F. Roberto

    2003-07-01

    Moderately thermophilic acidophilic bacteria were isolated from geothermal (30–83 °C) acidic (pH 2.7– 3.7) sites in Yellowstone National Park. The temperature maxima and pH minima of the isolates ranged from 50 to 65 °C, and pH 1.0–1.9. Eight of the bacteria were able to catalyze the dissimilatory oxidation of ferrous iron, and eleven could reduce ferric iron to ferrous iron in anaerobic cultures. Several of the isolates could also oxidize tetrathionate. Six of the iron-oxidizing isolates, and one obligate heterotroph, were low G+C gram-positive bacteria (Firmicutes). The former included three Sulfobacillus-like isolates (two closely related to a previously isolated Yellowstone strain, and the third to a mesophilic bacterium isolated from Montserrat), while the other three appeared to belong to a different genus. The other two iron-oxidizers were an Actinobacterium (related to Acidimicrobium ferrooxidans) and a Methylobacterium-like isolate (a genus within the a-Proteobacteria that has not previously been found to contain either iron-oxidizers or acidophiles). The other three (heterotrophic) isolates were also a-Proteobacteria and appeared be a novel thermophilic Acidisphaera sp. An ARDREA protocol was developed to discriminate between the iron-oxidizing isolates. Digestion of amplified rRNA genes with two restriction enzymes (SnaBI and BsaAI) separated these bacteria into five distinct groups; this result was confirmed by analysis of sequenced rRNA genes.

  17. Molecular characterization and identification of plant growth promoting endophytic bacteria isolated from the root nodules of pea (Pisum sativum L.).

    PubMed

    Tariq, Mohsin; Hameed, Sohail; Yasmeen, Tahira; Zahid, Mehwish; Zafar, Marriam

    2014-02-01

    Root nodule accommodates various non-nodulating bacteria at varying densities. Present study was planned to identify and characterize the non-nodulating bacteria from the pea plant. Ten fast growing bacteria were isolated from the root nodules of cultivated pea plants. These bacterial isolates were unable to nodulate pea plants in nodulation assay, which indicate the non-rhizobial nature of these bacteria. Bacterial isolates were tested in vitro for plant growth promoting properties including indole acetic acid (IAA) production, nitrogen fixation, phosphate solubilization, root colonization and biofilm formation. Six isolates were able to produce IAA at varying level from 0.86 to 16.16 μg ml(-1), with the isolate MSP9 being most efficient. Only two isolates, MSP2 and MSP10, were able to fix nitrogen. All isolates were able to solubilize inorganic phosphorus ranging from 5.57 to 11.73 μg ml(-1), except MSP4. Bacterial isolates showed considerably better potential for colonization on pea roots. Isolates MSP9 and MSP10 were most efficient in biofilm formation on polyvinyl chloride, which indicated their potential to withstand various biotic and abiotic stresses, whereas the remaining isolates showed a very poor biofilm formation ability. The most efficient plant growth promoting agents, MSP9 and MSP10, were phylogenetically identified by 16S rRNA gene sequence analysis as Ochrobactrum and Enterobacter, respectively, with 99% similarity. It is suggested the potential endophytic bacterial strains, Ochrobactrum sp. MSP9 and Enterobacter sp. MSP10, can be used as biofertilizers for various legume and non-legume crops after studying their interaction with the host crop and field evaluation.

  18. Molecular characterization and identification of plant growth promoting endophytic bacteria isolated from the root nodules of pea (Pisum sativum L.).

    PubMed

    Tariq, Mohsin; Hameed, Sohail; Yasmeen, Tahira; Zahid, Mehwish; Zafar, Marriam

    2014-02-01

    Root nodule accommodates various non-nodulating bacteria at varying densities. Present study was planned to identify and characterize the non-nodulating bacteria from the pea plant. Ten fast growing bacteria were isolated from the root nodules of cultivated pea plants. These bacterial isolates were unable to nodulate pea plants in nodulation assay, which indicate the non-rhizobial nature of these bacteria. Bacterial isolates were tested in vitro for plant growth promoting properties including indole acetic acid (IAA) production, nitrogen fixation, phosphate solubilization, root colonization and biofilm formation. Six isolates were able to produce IAA at varying level from 0.86 to 16.16 μg ml(-1), with the isolate MSP9 being most efficient. Only two isolates, MSP2 and MSP10, were able to fix nitrogen. All isolates were able to solubilize inorganic phosphorus ranging from 5.57 to 11.73 μg ml(-1), except MSP4. Bacterial isolates showed considerably better potential for colonization on pea roots. Isolates MSP9 and MSP10 were most efficient in biofilm formation on polyvinyl chloride, which indicated their potential to withstand various biotic and abiotic stresses, whereas the remaining isolates showed a very poor biofilm formation ability. The most efficient plant growth promoting agents, MSP9 and MSP10, were phylogenetically identified by 16S rRNA gene sequence analysis as Ochrobactrum and Enterobacter, respectively, with 99% similarity. It is suggested the potential endophytic bacterial strains, Ochrobactrum sp. MSP9 and Enterobacter sp. MSP10, can be used as biofertilizers for various legume and non-legume crops after studying their interaction with the host crop and field evaluation. PMID:24072498

  19. [Isolation of hydrocarbon-oxidizing psychrophilic bacteria from oil-polluted soils].

    PubMed

    Khomiakova, D V; Botvinko, I V; Netrusov, A I

    2003-01-01

    Microorganisms growing on a mineral medium with crude oil and its light fractions as only carbon and energy sources have been isolated from samples of oil-polluted soils collected in the Usa District (Komi Republic, Russia). For the first time, hydrocarbon-oxidizing psychrophilic bacteria of the genus Cytophaga have been found that are clearly capable of consuming crude oil hydrocarbons. A method for cultivating microorganisms on porous plastic is proposed. The data from the literature on the response of soil microbiota to oil pollution indicate that the pollution can activate or suppress the growth of various physiological groups of microorganisms [1]. Different soil and climatic conditions and pollution levels can give rise to different microbial cenoses, which include different associations and predominant microbial species.

  20. Technological and safety properties of lactic acid bacteria isolated from Spanish dry-cured sausages.

    PubMed

    Landeta, G; Curiel, J A; Carrascosa, A V; Muñoz, R; de las Rivas, B

    2013-10-01

    Technological and safety-related properties were analyzed in lactic acid bacteria isolated from Spanish dry-cured sausages in order to select them as starter cultures. In relation to technological properties, all the strains showed significative nitrate reductase activity; Lactobacillus plantarum, Lactobacillus paracasei and 52% of the Enterococcus faecium strains showed lipolytic activity and only Lactobacillus sakei strains (43%) were able to form biofilms. Related to safety aspects, E. faecium strains were the most resistant to antibiotics, whereas, L. sakei strains were the most sensitive. In relation to virulence factors, in the E. faecium strains analyzed, only the presence of efaA gene was detected. The analysis of biogenic amine production showed that most E. faecium strains and L. sakei Al-142 produced tyramine. In conclusion, L. paracasei Al-128 and L. sakei Al-143 strains possess the best properties to be selected as adequate and safe meat starter cultures.

  1. Endophytic bacteria isolated from orchid and their potential to promote plant growth.

    PubMed

    Faria, Deise Cristina; Dias, Armando Cavalcante Franco; Melo, Itamar Soares; de Carvalho Costa, Francisco Eduardo

    2013-02-01

    Twelve endophytic bacteria were isolated from the meristem of in vitro Cymbidium eburneum orchid, and screened according to indole yield quantified by colorimetric assay, in vitro phosphate solubilization, and potential for plant growth promotion under greenhouse conditions. Eight strains with positive results were classified into the genus Paenibacillus by FAME profile, and evaluated for their ability to increase survival and promote the growth of in vitro germinated Cattleya loddigesii seedlings during the acclimatization process. The obtained results showed that all strains produced detectable indole levels and did not exhibit potential for solubilizing inorganic phosphate. Particularly, an increase of the total biomass and number of leaves was observed. Two strains of Paenibacillus macerans promoted plant growth under greenhouse conditions. None of the treatments had a deleterious effect on growth of inoculated plants. These results suggest that these bacterial effects could be potentially useful to promote plant growth during seedling acclimatization in orchid species other than the species of origin.

  2. The metabolism of anthracene and 9,10-dimethylanthracene by bacteria isolated from waters.

    PubMed

    Traczewska, T M; Ochocka, R; Lamparczyk, H

    1991-01-01

    The metabolism of two polycyclic aromatic hydrocarbons i.e. anthracene and 9,10-dimethylanthracene by Micrococcus sp., Pseudomonas sp. and Bacillus macerans was examined. The above compounds were used as a sole carbon source for their growth. Using the reversed-phase thin layer chromatography techniques a number of anthracene and 9,10-dimethylanthracene metabolites were isolated and their structures identified spectroscopically. These included anthracene and 9,10-dimethylanthracene cis-dihydrodiols, hydroxy-methyl-derivatives and various phenolic compounds. Bacteria metabolise hydrocarbons using the dioxygenase enzyme system, which differs from the mammalian cytochrome P-450 monoxygenase. Hence in addition rat liver microsomal metabolism of the above hydrocarbons was investigated using the same separation techniques.

  3. A Screening Method for the Isolation of Polyhydroxyalkanoate-Producing Purple Non-sulfur Photosynthetic Bacteria from Natural Seawater

    PubMed Central

    Higuchi-Takeuchi, Mieko; Morisaki, Kumiko; Numata, Keiji

    2016-01-01

    Polyhydroxyalkanoates (PHAs) are a family of biopolyesters accumulated by a variety of microorganisms as carbon and energy storage under starvation conditions. We focused on marine purple non-sulfur photosynthetic bacteria as host microorganisms for PHA production and developed a method for their isolation from natural seawater. To identify novel PHA-producing marine purple non-sulfur photosynthetic bacteria, natural seawaters were cultured in nutrient-rich medium for purple non-sulfur photosynthetic bacteria, and twelve pink- or red-pigmented colonies were picked up. Gas chromatography mass spectrometry analysis revealed that four isolates synthesized PHA at levels ranging from 0.5 to 24.4 wt% of cell dry weight. The 16S ribosomal RNA sequence analysis revealed that one isolate (HM2) showed 100% identity to marine purple non-sulfur photosynthetic bacteria. In conclusion, we have demonstrated in this study that PHA-producing marine purple non-sulfur photosynthetic bacteria can be isolated from natural seawater under nutrient-rich conditions. PMID:27708640

  4. Antimicrobial resistance of bacteria isolated from slaughtered and retail chickens in South Africa.

    PubMed

    Manie, T; Khan, S; Brözel, V S; Veith, W J; Gouws, P A

    1998-04-01

    Animal feed is increasingly being supplemented with antibiotics to decrease the risk of epidemics in animal husbandry. This practice could lead to the selection for antibiotic resistant micro-organisms. The aim of this study was to determine the level of antibiotic resistant bacteria present on retail and abattoir chicken. Staphylococci, Enterobacteriaceae, Salmonella and isolates from total aerobic plate count were tested for resistance to vancomycin, streptomycin, methicillin, tetracycline and gentamicin using the disc diffusion susceptibility test; resistance to penicillin was determined using oxacillin. Results from the antibiotic code profile indicated that many of the bacterial strains were displaying multiple antibiotic resistance (MAR). A larger proportion of resistance to most antibiotics, except for vancomycin, was displayed by the abattoir samples, therefore suggesting that the incidence of MAR pathogenic bacteria was also higher in the abattoir samples. This resistance spectrum of abattoir samples is a result of farmers adding low doses of antibiotics to livestock feed to improve feeding efficiency so that the animals need less food to reach marketable weight. The lower incidence of MAR pathogenic bacteria in the retail samples is a result of resistance genes being lost due to lack of selective pressure, or to the fact that the resistant flora are being replaced by more sensitive flora during processing. The use of subtherapeutic levels of antibiotics for prophylaxis and as growth promoters remains a concern as the laws of evolution dictate that microbes will eventually develop resistance to practically any antibiotic. Selective pressure exerted by widespread antimicrobial use is therefore the driving force in the development of antibiotic resistance. This study indicated that a large proportion of the bacterial flora on fresh chicken is resistant to a variety of antibiotics, and that resultant food-related infections will be more difficult to treat.

  5. Isolation and partial characterization of bacteria in an anaerobic consortium that mineralizes 3-chlorobenzoic acid

    SciTech Connect

    Shelton, D.R.; Tiedje, J.M.

    1984-10-01

    A methanogenic consortium able to use 3-chlorobenzoic acid as its sole energy and carbon source was enriched from anaerobic sewage sludge. Seven bacteria were isolated from the consortium in mono- or coculture. They included: one dechlorinating bacterium, one benzoate-oxidizing bacterium, two butyrate-oxidizing bacteria, two H/sub 2/-consuming methanogens (methanospirillum hungatei PM-1 and Methanobacterium sp. strain PM-2), and a sulfate-reducing bacterium (Desulfovibrio sp.). The dechlorinating bacterium was a gram-negative, obligate anaerobe with a unique collar surrounding the cell. A medium containing rumen fluid supported minimal growth; pyruvate was the only substrate found to increase growth. The bacterium had a generation time of 4 to 5 days. 3-Chlorobenzoate was dechlorinated stoichiometrically to benzoate, which accumulated in the medium; the rate of dechlorination was ca. 0.1 pmol bacterium/sup -1/ day/sup -1/. The benzoate-oxidizing bacterium was a gram-negative, obligate anaerobe and could only be grown as a syntroph. Benzoate was the only substrate observed to support growth, and, when grown in coculture with M. hungatei, it was fermented to acetate and CH/sub 4/. One butyrate-oxidizing bacterium was a gram-negative, non-sporeforming, obligate anaerobe; the other was a gram-positive, sporeforming, obligate anaerobe. Both could only be grown as syntrophs. The substrates observed to support growth of both bacteria were butyrate, 2-DL-methylbutyrate, valerate, and caproate; isobutyrate supported growth of only the sporeforming bacterium. Fermentation products were acetate and CH/sub 4/ or acetate, propionate, and CH/sub 4/ when grown in coculture with M. hungatei. A mutualism among at least the dechlorinating, benzoate-oxidizing, and methane-forming members was apparently required for utilization of the 3-chlorobenzoate substrate. 21 references, 8 figures, 2 tables.

  6. Decarboxylation of substituted cinnamic acids by lactic acid bacteria isolated during malt whisky fermentation.

    PubMed

    van Beek, S; Priest, F G

    2000-12-01

    Seven strains of Lactobacillus isolated from malt whisky fermentations and representing Lactobacillus brevis, L. crispatus, L. fermentum, L. hilgardii, L. paracasei, L. pentosus, and L. plantarum contained genes for hydroxycinnamic acid (p-coumaric acid) decarboxylase. With the exception of L. hilgardii, these bacteria decarboxylated p-coumaric acid and/or ferulic acid, with the production of 4-vinylphenol and/or 4-vinylguaiacol, respectively, although the relative activities on the two substrates varied between strains. The addition of p-coumaric acid or ferulic acid to cultures of L. pentosus in MRS broth induced hydroxycinnamic acid decarboxylase mRNA within 5 min, and the gene was also induced by the indigenous components of malt wort. In a simulated distillery fermentation, a mixed culture of L. crispatus and L. pentosus in the presence of Saccharomyces cerevisiae decarboxylated added p-coumaric acid more rapidly than the yeast alone but had little activity on added ferulic acid. Moreover, we were able to demonstrate the induction of hydroxycinnamic acid decarboxylase mRNA under these conditions. However, in fermentations with no additional hydroxycinnamic acid, the bacteria lowered the final concentration of 4-vinylphenol in the fermented wort compared to the level seen in a pure-yeast fermentation. It seems likely that the combined activities of bacteria and yeast decarboxylate p-coumaric acid and then reduce 4-vinylphenol to 4-ethylphenol more effectively than either microorganism alone in pure cultures. Although we have shown that lactobacilli participate in the metabolism of phenolic compounds during malt whisky fermentations, the net result is a reduction in the concentrations of 4-vinylphenol and 4-vinylguaiacol prior to distillation.

  7. Characterization of N-Acylhomoserine Lactones Produced by Bacteria Isolated from Industrial Cooling Water Systems

    PubMed Central

    Okutsu, Noriya; Morohoshi, Tomohiro; Xie, Xiaonan; Kato, Norihiro; Ikeda, Tsukasa

    2015-01-01

    The cooling water systems are used to remove heat generated in the various industries. Biofouling of the cooling water systems causes blocking of condenser pipes and the heat exchanger tubes. In many Gram-negative bacteria, N-acylhomoserine lactone (AHL) are used as quorum-sensing signal molecule and associated with biofilm formation. To investigate the relationship between quorum sensing and biofouling in the cooling water system, we isolated a total of 192 bacterial strains from the five cooling water systems, and screened for AHL production. Seven isolates stimulated AHL-mediated purple pigment production in AHL reporter strain Chromobacterium violaceum CV026 or VIR07. Based on their 16S rRNA gene sequences, AHL-producing isolates were assigned to Aeromonas hydrophila, Lysobacter sp., Methylobacterium oryzae, and Bosea massiliensis. To the best of our knowledge, B. massiliensis and Lysobacter sp. have not been reported as AHL-producing species in the previous researches. AHLs extracted from the culture supernatants of B. massiliensis and Lysobacter sp. were identified by liquid chromatography-mass spectrometry. AHLs produced by B. massiliensis were assigned as N-hexanoyl-l-homoserine lactone (C6-HSL), N-(3-oxohexanoyl)-l-homoserine lactone (3-oxo-C6-HSL), and N-(3-oxooctanoyl)-l-homoserine lactone (3-oxo-C8-HSL). AHLs produced by Lysobacter sp. were assigned as N-decanoyl-l-homoserine lactone (C10-HSL) and N-(3-oxodecanoyl)-l-homoserine lactone (3-oxo-C10-HSL). This is the first report of identification of AHLs produced by B. massiliensis and Lysobacter sp. isolated from the cooling water system. PMID:26729121

  8. Isolation and Characterization of Endophytic Colonizing Bacteria from Agronomic Crops and Prairie Plants†

    PubMed Central

    Zinniel, Denise K.; Lambrecht, Pat; Harris, N. Beth; Feng, Zhengyu; Kuczmarski, Daniel; Higley, Phyllis; Ishimaru, Carol A.; Arunakumari, Alahari; Barletta, Raúl G.; Vidaver, Anne K.

    2002-01-01

    Endophytic bacteria reside within plant hosts without causing disease symptoms. In this study, 853 endophytic strains were isolated from aerial tissues of four agronomic crop species and 27 prairie plant species. We determined several phenotypic properties and found approximately equal numbers of gram-negative and gram-positive isolates. In a greenhouse study, 28 of 86 prairie plant endophytes were found to colonize their original hosts at 42 days postinoculation at levels of 3.5 to 7.7 log10 CFU/g (fresh weight). More comprehensive colonization studies were conducted with 373 corn and sorghum endophytes. In growth room studies, none of the isolates displayed pathogenicity, and 69 of the strains were recovered from corn or sorghum seedlings at levels of 8.3 log10 CFU/plant or higher. Host range greenhouse studies demonstrated that 26 of 29 endophytes were recoverable from at least one host other than corn and sorghum at levels of up to 5.8 log10 CFU/g (fresh weight). Long-range dent corn greenhouse studies and field trials with 17 wild-type strains and 14 antibiotic-resistant mutants demonstrated bacterial persistence at significant average colonization levels ranging between 3.4 and 6.1 log10 CFU/g (fresh weight) up to 78 days postinoculation. Three prairie and three agronomic endophytes exhibiting the most promising levels of colonization and an ability to persist were identified as Cellulomonas, Clavibacter, Curtobacterium, and Microbacterium isolates by 16S rRNA gene sequence, fatty acid, and carbon source utilization analyses. This study defines for the first time the endophytic nature of Microbacterium testaceum. These microorganisms may be useful for biocontrol and other applications. PMID:11976089

  9. Isolation of sulfate-reducing bacteria from sediments above the deep-subseafloor aquifer.

    PubMed

    Fichtel, Katja; Mathes, Falko; Könneke, Martin; Cypionka, Heribert; Engelen, Bert

    2012-01-01

    On a global scale, crustal fluids fuel a large part of the deep-subseafloor biosphere by providing electron acceptors for microbial respiration. In this study, we examined bacterial cultures from sediments of the Juan de Fuca Ridge, Northeast Pacific (IODP Site U1301). The sediments comprise three distinctive compartments: an upper sulfate-containing zone, formed by bottom-seawater diffusion, a sulfate-depleted zone, and a second (∼140 m thick) sulfate-containing zone influenced by fluid diffusion from the basaltic aquifer. In order to identify and characterize sulfate-reducing bacteria, enrichment cultures from different sediment layers were set up, analyzed by molecular screening, and used for isolating pure cultures. The initial enrichments harbored specific communities of heterotrophic microorganisms. Strains affiliated to Desulfosporosinus lacus, Desulfotomaculum sp., and Desulfovibrio aespoeensis were isolated only from the top layers (1.3-9.1 meters below seafloor, mbsf), while several strains of Desulfovibrio indonesiensis and a relative of Desulfotignum balticum were obtained from near-basement sediments (240-262 mbsf). Physiological tests on three selected strains affiliated to Dv. aespoeensis, Dv. indonesiensis, and Desulfotignum balticum indicated that all reduce sulfate with a limited number of short-chain n-alcohols or fatty acids and were able to ferment either ethanol, pyruvate, or betaine. All three isolates shared the capacity of growing chemolithotrophically with H(2) as sole electron donor. Strain P23, affiliating with Dv. indonesiensis, even grew autotrophically in the absence of any organic compounds. Thus, H(2) might be an essential electron donor in the deep-subseafloor where the availability of organic substrates is limited. The isolation of non-sporeforming sulfate reducers from fluid-influenced layers indicates that they have survived the long-term burial as active populations even after the separation from the seafloor hundreds

  10. Isolation of Sulfate-Reducing Bacteria from Sediments Above the Deep-Subseafloor Aquifer

    PubMed Central

    Fichtel, Katja; Mathes, Falko; Könneke, Martin; Cypionka, Heribert; Engelen, Bert

    2011-01-01

    On a global scale, crustal fluids fuel a large part of the deep-subseafloor biosphere by providing electron acceptors for microbial respiration. In this study, we examined bacterial cultures from sediments of the Juan de Fuca Ridge, Northeast Pacific (IODP Site U1301). The sediments comprise three distinctive compartments: an upper sulfate-containing zone, formed by bottom-seawater diffusion, a sulfate-depleted zone, and a second (∼140 m thick) sulfate-containing zone influenced by fluid diffusion from the basaltic aquifer. In order to identify and characterize sulfate-reducing bacteria, enrichment cultures from different sediment layers were set up, analyzed by molecular screening, and used for isolating pure cultures. The initial enrichments harbored specific communities of heterotrophic microorganisms. Strains affiliated to Desulfosporosinus lacus, Desulfotomaculum sp., and Desulfovibrio aespoeensis were isolated only from the top layers (1.3–9.1 meters below seafloor, mbsf), while several strains of Desulfovibrio indonesiensis and a relative of Desulfotignum balticum were obtained from near-basement sediments (240–262 mbsf). Physiological tests on three selected strains affiliated to Dv. aespoeensis, Dv. indonesiensis, and Desulfotignum balticum indicated that all reduce sulfate with a limited number of short-chain n-alcohols or fatty acids and were able to ferment either ethanol, pyruvate, or betaine. All three isolates shared the capacity of growing chemolithotrophically with H2 as sole electron donor. Strain P23, affiliating with Dv. indonesiensis, even grew autotrophically in the absence of any organic compounds. Thus, H2 might be an essential electron donor in the deep-subseafloor where the availability of organic substrates is limited. The isolation of non-sporeforming sulfate reducers from fluid-influenced layers indicates that they have survived the long-term burial as active populations even after the separation from the seafloor hundreds

  11. Characterization of N-Acylhomoserine Lactones Produced by Bacteria Isolated from Industrial Cooling Water Systems.

    PubMed

    Okutsu, Noriya; Morohoshi, Tomohiro; Xie, Xiaonan; Kato, Norihiro; Ikeda, Tsukasa

    2015-01-01

    The cooling water systems are used to remove heat generated in the various industries. Biofouling of the cooling water systems causes blocking of condenser pipes and the heat exchanger tubes. In many Gram-negative bacteria, N-acylhomoserine lactone (AHL) are used as quorum-sensing signal molecule and associated with biofilm formation. To investigate the relationship between quorum sensing and biofouling in the cooling water system, we isolated a total of 192 bacterial strains from the five cooling water systems, and screened for AHL production. Seven isolates stimulated AHL-mediated purple pigment production in AHL reporter strain Chromobacterium violaceum CV026 or VIR07. Based on their 16S rRNA gene sequences, AHL-producing isolates were assigned to Aeromonas hydrophila, Lysobacter sp., Methylobacterium oryzae, and Bosea massiliensis. To the best of our knowledge, B. massiliensis and Lysobacter sp. have not been reported as AHL-producing species in the previous researches. AHLs extracted from the culture supernatants of B. massiliensis and Lysobacter sp. were identified by liquid chromatography-mass spectrometry. AHLs produced by B. massiliensis were assigned as N-hexanoyl-L-homoserine lactone (C6-HSL), N-(3-oxohexanoyl)-L-homoserine lactone (3-oxo-C6-HSL), and N-(3-oxooctanoyl)-L-homoserine lactone (3-oxo-C8-HSL). AHLs produced by Lysobacter sp. were assigned as N-decanoyl-L-homoserine lactone (C10-HSL) and N-(3-oxodecanoyl)-L-homoserine lactone (3-oxo-C10-HSL). This is the first report of identification of AHLs produced by B. massiliensis and Lysobacter sp. isolated from the cooling water system.

  12. Enrichment and isolation of acidophilic sulfate-reducing bacteria from Tinto River sediments.

    PubMed

    Sánchez-Andrea, Irene; Stams, Alfons J M; Amils, Ricardo; Sanz, José Luis

    2013-10-01

    Although some acidophilic and alkaliphilic species have been described recently, most of the known sulfate-reducing bacteria (SRB) grow optimally at neutral pH. In this study, sulfate reduction was studied with sediment samples from the extremely acidic Tinto River basin. Stable enrichments of SRB were obtained at pH 4 with glycerol, methanol and hydrogen; at pH 4.5 with lactate and at pH 5.5 with succinate as substrates. Inhibition of sulfate reduction by organic acids below their pKa was observed. Cloning and sequencing of 16S rRNA gene showed that fermentative bacteria (Paludibacter spp., Oscillibacter spp.) and SRB (Thermodesulfobium spp., Desulfosporosinus spp., Desulfitobacterium spp., Desulfotomaculum spp.) were co-enriched. By repeated serial dilutions and streaking on agar plates, four strains of SRB belonging to the Firmicutes phylum were obtained. Two of them show 96% 16S rRNA gene sequence similarity with Desulfosporosinus acidophilus, and a third one with Desulfosporosinus orientis. Another isolate has just 93% rRNA gene sequence similarity with the Desulfosporosinus/Desulfitobacterium cluster and might represent a novel species within a novel genus. One of the Desulfosporosinus strains was further investigated showing maximum growth at pH 5.5, and a pH-dependent inhibitory effect of organic acids and sulfide.

  13. Supporting data for identification of biosurfactant-producing bacteria isolated from agro-food industrial effluent

    PubMed Central

    Fulazzaky, Mohamad Ali; Abdullah, Shakila; Salim, Mohd Razman

    2016-01-01

    The goal of this study was to identify the biosurfactant-producing bacteria isolated from agro-food industrial effluet. The identification of the potential bacterial strain using a polymerase chain reaction of the 16S rRNA gene analysis was closely related to Serratia marcescens with its recorded strain of SA30 “Fundamentals of mass transfer and kinetics for biosorption of oil and grease from agro-food industrial effluent by Serratia marcescens SA30” (Fulazzaky et al., 2015) [1]; however, many biochemical tests have not been published yet. The biochemical tests of biosurfactant production, haemolytic assay and cell surface hydrophobicity were performed to investigate the beneficial strain of biosurfactant-producing bacteria. Here we do share data collected from the biochemical tests to get a better understanding of the use of Serratia marcescens SA30 to degrade oil, which contributes the technical features of strengthening the biological treatment of oil-contaminated wastewater in tropical environments. PMID:27077083

  14. Potential of the adhesion of bacteria isolated from drinking water to materials.

    PubMed

    Simões, Lúcia Chaves; Simões, Manuel; Oliveira, Rosário; Vieira, Maria João

    2007-04-01

    Heterotrophic bacteria (11 genera, 14 species, 25 putative strains) were isolated from drinking water, identified either biochemically or by partial 16s rDNA gene sequencing and their adherence characteristics were determined by two methods: i. thermodynamic prediction of adhesion potential by measuring hydrophobicity (contact angle measurements) and ii. by measuring adherence to eight different substrata (ASI 304 and 316 stainless steel, copper, polyvinyl chloride, polypropylene, polyethylene, silicone and glass). All the test organisms were hydrophilic and inter-species variation in hydrophobicity occurred only for Comamonas acidovorans. Stainless steel 304 (SS 304), copper, polypropylene (PP), polyethylene (PE) and silicone thermodynamically favoured adhesion for the majority of test strains (>18/25), whilst adhesion was generally less thermodynamically favorable for stainless steel 316 (SS 316), polyvinyl chloride (PVC) and glass. The predictability of thermodynamic adhesion test methods was validated by comparison with 24-well microtiter plate assays using nine reference strains and three adhesion surfaces (SS 316, PVC and PE). Results for Acinetobacter calcoaceticus, Burkolderia cepacia and Stenotrophomonas maltophilia sp. 2 were congruent between both methods whilst they differed for the other bacteria to at least one material. Only A. calcoaceticus had strongly adherent properties to the three tested surfaces. Strain variation in adhesion ability was detected only for Sphingomonas capsulata. Analysis of adhesion demonstrated that in addition to physicochemical surface properties of bacterium and substratum, biological factors are involved in early adhesion processes, suggesting that reliance on thermodynamic approaches alone may not accurately predict adhesion capacity. PMID:17440920

  15. Antibacterial activity of [10]-gingerol and [12]-gingerol isolated from ginger rhizome against periodontal bacteria.

    PubMed

    Park, Miri; Bae, Jungdon; Lee, Dae-Sil

    2008-11-01

    Ginger (Zingiber officinale Roscoe) has been used widely as a food spice and an herbal medicine. In particular, its gingerol-related components have been reported to possess antimicrobial and antifungal properties, as well as several pharmaceutical properties. However, the effective ginger constituents that inhibit the growth of oral bacteria associated with periodontitis in the human oral cavity have not been elucidated. This study revealed that the ethanol and n-hexane extracts of ginger exhibited antibacterial activities against three anaerobic Gram-negative bacteria, Porphyromonas gingivalis ATCC 53978, Porphyromonas endodontalis ATCC 35406 and Prevotella intermedia ATCC 25611, causing periodontal diseases. Thereafter, five ginger constituents were isolated by a preparative high-performance liquid chromatographic method from the active silica-gel column chromatography fractions, elucidated their structures by nuclear magnetic resonance spectroscopy and electrospray ionization mass spectrometry and their antibacterial activity evaluated. In conclusion, two highly alkylated gingerols, [10]-gingerol and [12]-gingerol effectively inhibited the growth of these oral pathogens at a minimum inhibitory concentration (MIC) range of 6-30 microg/mL. These ginger compounds also killed the oral pathogens at a minimum bactericidal concentration (MBC) range of 4-20 microg/mL, but not the other ginger compounds 5-acetoxy-[6]-gingerol, 3,5-diacetoxy-[6]-gingerdiol and galanolactone. PMID:18814211

  16. Exploiting the fungal highway: development of a novel tool for the in situ isolation of bacteria migrating along fungal mycelium.

    PubMed

    Simon, Anaele; Bindschedler, Saskia; Job, Daniel; Wick, Lukas Y; Filippidou, Sevasti; Kooli, Wafa M; Verrecchia, Eric P; Junier, Pilar

    2015-11-01

    Fungi and bacteria form various associations that are central to numerous environmental processes. In the so-called fungal highway, bacteria disperse along fungal mycelium. We developed a novel tool for the in situ isolation of bacteria moving along fungal hyphae as well as for the recovery of fungi potentially involved in dispersal, both of which are attracted towards a target culture medium. We present the validation and the results of the first in situ test. Couples of fungi and bacteria were isolated from soil. Amongst the enriched organisms, we identified several species of fast-growing fungi (Fusarium sp. and Chaetomium sp.), as well as various potentially associated bacterial groups, including Variovorax soli, Olivibacter soli, Acinetobacter calcoaceticus, and several species of the genera Stenotrophomonas, Achromobacter and Ochrobactrum. Migration of bacteria along fungal hyphae across a discontinuous medium was confirmed in most of the cases. Although the majority of the bacteria for which migration was confirmed were also positive for flagellar motility, not all motile bacteria dispersed using their potential fungal partner. In addition, the importance of hydrophobicity of the fungal mycelial surface was confirmed. Future applications of the columns include targeting different types of microorganisms and their interactions, either by enrichment or by state of the art molecular biological methods.

  17. Exploiting the fungal highway: development of a novel tool for the in situ isolation of bacteria migrating along fungal mycelium.

    PubMed

    Simon, Anaele; Bindschedler, Saskia; Job, Daniel; Wick, Lukas Y; Filippidou, Sevasti; Kooli, Wafa M; Verrecchia, Eric P; Junier, Pilar

    2015-11-01

    Fungi and bacteria form various associations that are central to numerous environmental processes. In the so-called fungal highway, bacteria disperse along fungal mycelium. We developed a novel tool for the in situ isolation of bacteria moving along fungal hyphae as well as for the recovery of fungi potentially involved in dispersal, both of which are attracted towards a target culture medium. We present the validation and the results of the first in situ test. Couples of fungi and bacteria were isolated from soil. Amongst the enriched organisms, we identified several species of fast-growing fungi (Fusarium sp. and Chaetomium sp.), as well as various potentially associated bacterial groups, including Variovorax soli, Olivibacter soli, Acinetobacter calcoaceticus, and several species of the genera Stenotrophomonas, Achromobacter and Ochrobactrum. Migration of bacteria along fungal hyphae across a discontinuous medium was confirmed in most of the cases. Although the majority of the bacteria for which migration was confirmed were also positive for flagellar motility, not all motile bacteria dispersed using their potential fungal partner. In addition, the importance of hydrophobicity of the fungal mycelial surface was confirmed. Future applications of the columns include targeting different types of microorganisms and their interactions, either by enrichment or by state of the art molecular biological methods. PMID:26432804

  18. Antibiotic resistance among bacteria isolated from seawater and penguin fecal samples collected near Palmer Station, Antarctica.

    PubMed

    Miller, Robert V; Gammon, Katharine; Day, Martin J

    2009-01-01

    Antibiotic resistance in aquatic bacteria has increased steadily as a consequence of the widespread use of antibiotics, but practice and international treaty should have limited antibiotic contamination in Antarctica. We estimated antibiotic resistance in microorganisms isolated from the Antarctic marine waters and a penguin rookery, for 2 reasons: (i) as a measure of human impact and (ii) as a potential "snapshot" of the preantibiotic world. Samples were taken at 4 established sampling sites near Palmer Station, which is situated at the southern end of the Palmer Archipelago (64 degrees 10'S, 61 degrees 50'W). Sites were chosen to provide different potentials for human contamination. Forty 50 mL samples of seawater were collected and colony-forming units (CFU)/mL were determined at 6 and 20 degrees C. For this study, presumed psychrophiles (growth at 6 degrees C) were assumed to be native to Antarctic waters, whereas presumed mesophiles (growth at 20 degrees C but not at 6 degrees C) were taken to represent introduced organisms. The 20-6 degrees C CFU/mL ratio was used as a measure of the relative impact to the ecosystem of presumably introduced organisms. This ratio was highest at the site nearest to Palmer Station and decreased with distance from it, suggesting that human presence has impacted the natural microbial flora of the site. The frequency of resistance to 5 common antibiotics was determined in each group of isolates. Overall drug resistance was higher among the presumed mesophiles than the presumed psychrophiles and increased with proximity to Palmer Station, with the presumed mesophiles showing higher frequencies of single and multiple drug resistance than the psychrophile population. The frequency of multidrug resistance followed the same pattern. It appears that multidrug resistance is low among native Antarctic bacteria but is increased by human habitation.

  19. Isolation and Characterization of Gram-Positive Piezophilic Bacteria from Deep Marine Subsurface Sediment

    NASA Astrophysics Data System (ADS)

    Runko, G. M.; Fang, J.; Kato, C.

    2014-12-01

    The marine deep biosphere remains as the least studied of all of Earth's habitats and is inadequately understood, but is extremely important to understand the impacts that microbes have on global biogeochemical cycles. Sediment samples were obtained during IODP Expedition 337 in the western Pacific Ocean, from 1,498 meters below the seafloor (mbsf; samples 6R3), 1,951-1,999 mbsf (19R1), and 2,406 mbsf (29R7). These samples were initially mixed with marine broth and cultivated under anaerobic conditions at pressure of 35 MPa (megapascal) and temperatures of 35° C, 45° C, and 55° C for 3 months on board the Chikyu. Single colonies were isolated via plating on marine broth. Then, six strains of bacteria were identified, 6R3-1, 6R3-15, 19R1-5, 29R7-12B, 29R7-12M, and 29R7-12S. The six strains were then examined for optimal growth temperature and pressure. These organisms are Gram-positive, spore-forming, facultative anaerobic piezophilic bacteria. Major fatty acids are anteiso-15:0, anteiso-17:0 and iso-15:0. Phylogenetic analysis of 16S rRNA gene sequences revealed that the isolates are closely related to Virgibacillus pantothenticus, Robinsoniella peoriensis, and Bacillus subtilis. Because of their abundance in the deep marine subsurface, these microorganisms likely play an important role in sustaining the deep microbial ecosystem and influencing biogeochemical cycles in the deep biosphere.

  20. Rapid isolation of gluten-digesting bacteria from human stool and saliva by using gliadin-containing plates.

    PubMed

    Berger, Martina; Sarantopoulos, Christos; Ongchangco, Deryn; Sry, Jeremy; Cesario, Thomas

    2015-07-01

    The number of individuals with gluten intolerance has increased dramatically over the last years. To date, the only therapy for gluten intolerance is the complete avoidance of dietary gluten. To sustain a strictly gluten-free diet, however, is very challenging. Therefore, there is need for a non-dietary therapy. Any such treatment must appreciate that the immunogenic part of gluten are gliadin peptides which are poorly degraded by the enzymes of the gastrointestinal tract. Probiotic therapy and oral enzyme therapy containing gluten-degrading bacteria (GDB) and their gliadin-digesting enzymes are possible new approaches for the treatment of gluten intolerance, however effectively isolating GDB for these treatments is problematic. The goal of this study was to develop an easy technique to isolate GDB rapidly and efficiently with the hope it might lead to newer ways of developing either probiotics or traditional medicines to treat gluten intolerance. Several researchers have already isolated successfully GDB by using gluten minimal or limited agar plates. Although these plates can be used to isolate bacteria which can tolerate gluten, further assays are needed to investigate if the same bacteria can also digest gluten. The agar plates we developed can detect bacteria which cannot only tolerate gluten but are able to digest it as well. Therefore, we were able to combine two steps into one step. Using such technologies, we were able to isolate five GDB from saliva and stool, and identified three bacterial reference strains with gluten-degrading activity. The technique we developed to isolate bacteria with gluten-degrading activity is fast, effective, and easy to use. The GDB isolated by our technology could have potential as part of a probiotic or enzymatic therapy for people with gluten intolerance.

  1. Rapid isolation of gluten-digesting bacteria from human stool and saliva by using gliadin-containing plates

    PubMed Central

    Sarantopoulos, Christos; Ongchangco, Deryn; Sry, Jeremy; Cesario, Thomas

    2014-01-01

    The number of individuals with gluten intolerance has increased dramatically over the last years. To date, the only therapy for gluten intolerance is the complete avoidance of dietary gluten. To sustain a strictly gluten-free diet, however, is very challenging. Therefore, there is need for a non-dietary therapy. Any such treatment must appreciate that the immunogenic part of gluten are gliadin peptides which are poorly degraded by the enzymes of the gastrointestinal tract. Probiotic therapy and oral enzyme therapy containing gluten-degrading bacteria (GDB) and their gliadin-digesting enzymes are possible new approaches for the treatment of gluten intolerance, however effectively isolating GDB for these treatments is problematic. The goal of this study was to develop an easy technique to isolate GDB rapidly and efficiently with the hope it might lead to newer ways of developing either probiotics or traditional medicines to treat gluten intolerance. Several researchers have already isolated successfully GDB by using gluten minimal or limited agar plates. Although these plates can be used to isolate bacteria which can tolerate gluten, further assays are needed to investigate if the same bacteria can also digest gluten. The agar plates we developed can detect bacteria which cannot only tolerate gluten but are able to digest it as well. Therefore, we were able to combine two steps into one step. Using such technologies, we were able to isolate five GDB from saliva and stool, and identified three bacterial reference strains with gluten-degrading activity. The technique we developed to isolate bacteria with gluten-degrading activity is fast, effective, and easy to use. The GDB isolated by our technology could have potential as part of a probiotic or enzymatic therapy for people with gluten intolerance. PMID:25519429

  2. Diversity of Bacteria Carried by Pinewood Nematode in USA and Phylogenetic Comparison with Isolates from Other Countries

    PubMed Central

    Proença, Diogo Neves; Fonseca, Luís; Powers, Thomas O.; Abrantes, Isabel M. O.; Morais, Paula V.

    2014-01-01

    Pine wilt disease (PWD) is native to North America and has spread to Asia and Europe. Lately, mutualistic relationship has been suggested between the pinewood nematode (PWN), Bursaphelenchus xylophilus the causal nematode agent of PWD, and bacteria. In countries where PWN occurs, nematodes from diseased trees were reported to carry bacteria from several genera. However no data exists for the United States. The objective of this study was to evaluate the diversity of the bacterial community carried by B. xylophilus, isolated from different Pinus spp. with PWD in Nebraska, United States. The bacteria carried by PWN belonged to Gammaproteobacteria (79.9%), Betaproteobacteria (11.7%), Bacilli (5.0%), Alphaproteobacteria (1.7%) and Flavobacteriia (1.7%). Strains from the genera Chryseobacterium and Pigmentiphaga were found associated with the nematode for the first time. These results were compared to results from similar studies conducted from other countries of three continents in order to assess the diversity of bacteria with associated with PWN. The isolates from the United States, Portugal and China belonged to 25 different genera and only strains from the genus Pseudomonas were found in nematodes from all countries. The strains from China were closely related to P. fluorescens and the strains isolated from Portugal and USA were phylogenetically related to P. mohnii and P. lutea. Nematodes from the different countries are associated with bacteria of different species, not supporting a relationship between PWN with a particular bacterial species. Moreover, the diversity of the bacteria carried by the pinewood nematode seems to be related to the geographic area and the Pinus species. The roles these bacteria play within the pine trees or when associated with the nematodes, might be independent of the presence of the nematode in the tree and only related on the bacteria's relationship with the tree. PMID:25127255

  3. Calcium carbonate mineralization: involvement of extracellular polymeric materials isolated from calcifying bacteria.

    PubMed

    Ercole, Claudia; Bozzelli, Paola; Altieri, Fabio; Cacchio, Paola; Del Gallo, Maddalena

    2012-08-01

    This study highlights the role of specific outer bacterial structures, such as the glycocalix, in calcium carbonate crystallization in vitro. We describe the formation of calcite crystals by extracellular polymeric materials, such as exopolysaccharides (EPS) and capsular polysaccharides (CPS) isolated from Bacillus firmus and Nocardia calcarea. Organic matrices were isolated from calcifying bacteria grown on synthetic medium--in the presence or absence of calcium ions--and their effect on calcite precipitation was assessed. Scanning electron microscopy observations and energy dispersive X-ray spectrometry analysis showed that CPS and EPS fractions were involved in calcium carbonate precipitation, not only serving as nucleation sites but also through a direct role in crystal formation. The utilization of different synthetic media, with and without addition of calcium ions, influenced the biofilm production and protein profile of extracellular polymeric materials. Proteins of CPS fractions with a molecular mass between 25 and 70 kDa were overexpressed when calcium ions were present in the medium. This higher level of protein synthesis could be related to the active process of bioprecipitation.

  4. Identification and phylogenetic analysis of new sulfate-reducing bacteria isolated from oilfield samples.

    PubMed

    Chen, Wu; Xiang, Fu; Fu, Jie; Wang, Qiang; Wang, Wenjun; Zeng, Qingfu; Yu, Longjiang

    2009-01-01

    Microbiologically influenced corrosion (MIC) caused by sulfate-reducing bacteria (SRB) has been investigated in an oilfield injection water system. Strain CW-01 was isolated from an oilfield and strain CW-04 was isolated from biofilm dirt of pipeline walls. The strains were facultative anaerobes, non-motile, Gram-positive, pole flagellum, and spore-forming curved rods. The growth was observed over the temperature range 20-70 degrees C. Strain CW-01 grew optimally at 37 degrees C. The pH range for growth was 3.0-11, optimal at pH 6.0. Strain CW-04 grew optimally at 48 degrees C. The pH range for growth was 3.0-10, optimal at pH 7.2. The strains grew at a very broad range of salt concentrations. Optimal growth was observed with 1.5 g/L NaCl for strain CW-01 and 0.7 g/L NaCl for strain CW-04. The strains showed most similarity in physiological characteristics, except for acetone and saccharose. Analysis of the 16S rDNA sequences allowed strains CW-01 and CW-04 to be classified into the genus Desulfotomaculum. The corrosion speciality of the strains had been comparatively investigated. Especially SRB's growth curve, bearable oxygen capability, drug fastness and corrosion rate had been analyzed. The results showed that it is difficult to prevent bacterial corrosion caused by these two strains.

  5. The Spider Venom Peptide Lycosin-II Has Potent Antimicrobial Activity against Clinically Isolated Bacteria

    PubMed Central

    Wang, Yongjun; Wang, Ling; Yang, Huali; Xiao, Haoliang; Farooq, Athar; Liu, Zhonghua; Hu, Min; Shi, Xiaoliu

    2016-01-01

    Antimicrobial peptides have been accepted as excellent candidates for developing novel antibiotics against drug-resistant bacteria. Recent studies indicate that spider venoms are the source for the identification of novel antimicrobial peptides. In the present study, we isolated and characterized an antibacterial peptide named lycosin-II from the venom of the spider Lycosa singoriensis. It contains 21 amino acid residue lacking cysteine residues and forms a typical linear amphipathic and cationic α-helical conformation. Lycosin-II displays potent bacteriostatic effect on the tested drug-resistant bacterial strains isolated from hospital patients, including multidrug-resistant A. baumannii, which has presented a huge challenge for the infection therapy. The inhibitory ability of lycosin-II might derive from its binding to cell membrane, because Mg2+ could compete with the binding sites to reduce the bacteriostatic potency of lycosin-II. Our data suggest that lycosin-II might be a lead in the development of novel antibiotics for curing drug-resistant bacterial infections. PMID:27128941

  6. The Spider Venom Peptide Lycosin-II Has Potent Antimicrobial Activity against Clinically Isolated Bacteria.

    PubMed

    Wang, Yongjun; Wang, Ling; Yang, Huali; Xiao, Haoliang; Farooq, Athar; Liu, Zhonghua; Hu, Min; Shi, Xiaoliu

    2016-04-26

    Antimicrobial peptides have been accepted as excellent candidates for developing novel antibiotics against drug-resistant bacteria. Recent studies indicate that spider venoms are the source for the identification of novel antimicrobial peptides. In the present study, we isolated and characterized an antibacterial peptide named lycosin-II from the venom of the spider Lycosa singoriensis. It contains 21 amino acid residue lacking cysteine residues and forms a typical linear amphipathic and cationic α-helical conformation. Lycosin-II displays potent bacteriostatic effect on the tested drug-resistant bacterial strains isolated from hospital patients, including multidrug-resistant A. baumannii, which has presented a huge challenge for the infection therapy. The inhibitory ability of lycosin-II might derive from its binding to cell membrane, because Mg(2+) could compete with the binding sites to reduce the bacteriostatic potency of lycosin-II. Our data suggest that lycosin-II might be a lead in the development of novel antibiotics for curing drug-resistant bacterial infections.

  7. Antibacterial metabolites synthesized by psychrotrophic bacteria isolated from cold-freshwater environments.

    PubMed

    Barros, Javier; Becerra, José; González, Carlos; Martínez, Miguel

    2013-03-01

    The ability of three psychrotrophic Gram-negative bacilli isolated from Chilean Patagonian cold freshwater rivers to produce bioactive metabolites was evaluated. The strains were isolated from cold waters rivers and identified by their biochemical properties and 16S rRNA gene analysis. The metabolites fractions showing antibacterial activity were obtained by solvent extraction and partially characterized by gas-mass chromatography (GC-MS). Antibacterial activity of the fractions was evaluated by an agar-well diffusion test upon 14 bacterial strains, both Gram positive and Gram negative. Thermal and proteolytic resistances of the antibacterial metabolites fractions were also evaluated. Molecular analysis allows the identification of the three Patagonian strains as Pseudomonas sp. RG-6 (Pseudomonas brenneri 99.6 % identity), Pseudomonas sp. RG-8 (Pseudomonas trivialis 99.6 % identity) and Yersinia sp. RP-3 (Yersinia aldovae 99.5 % identity). These extracts were able to inhibit both Gram-positive and Gram-negative bacteria but not Listeria monocytogenes. The antibacterial activity of the filtrated supernatants was lost at temperatures ≥60 °C, and was not affected by proteinase K treatment. The chemical structure of the active molecule remains to be elucidated, although the GC-MS analysis of the filtrates suggests that compounds like sesquiterpenes derivatives from β-maaliene or δ-selinene could be responsible of this antibacterial activity. Pristine cold freshwater streams showed to be interesting sources of metabolites-producing microorganisms with antibacterial activity. PMID:22886611

  8. Bacteria isolated from Korean black raspberry vinegar with low biogenic amine production in wine.

    PubMed

    Song, Nho-Eul; Cho, Hyoun-Suk; Baik, Sang-Ho

    2016-01-01

    A high concentration of histamine, one of the biogenic amines (BAs) usually found in fermented foods, can cause undesirable physiological side effects in sensitive humans. The objective of this study is to isolate indigenous Acetobacter strains from naturally fermented Bokbunja vinegar in Korea with reduced histamine production during starter fermentation. Further, we examined its physiological and biochemical properties, including BA synthesis. The obtained strain MBA-77, identified as Acetobacter aceti by 16S rDNA homology and biochemical analysis and named A. aceti MBA-77. A. aceti MBA-77 showed optimal acidity % production at pH 5; the optimal temperature was 25°C. When we prepared and examined the BAs synthesis spectrum during the fermentation process, Bokbunja wine fermented with Saccharomyces cerevisiae showed that the histamine concentration increased from 2.72 of Bokbunja extract to 5.29mg/L and cadaverine and dopamine was decreased to 2.6 and 10.12mg/L, respectively. Bokbunja vinegar prepared by A. aceti MBA-77 as the starter, the histamine concentration of the vinegar preparation step was decreased up to 3.66mg/L from 5.29mg/L in the wine preparation step. To our knowledge, this is the first report to demonstrate acetic acid bacteria isolated from Bokbunja seed vinegar with low spectrum BA and would be useful for wellbeing vinegar preparation.

  9. Calcium carbonate mineralization: involvement of extracellular polymeric materials isolated from calcifying bacteria.

    PubMed

    Ercole, Claudia; Bozzelli, Paola; Altieri, Fabio; Cacchio, Paola; Del Gallo, Maddalena

    2012-08-01

    This study highlights the role of specific outer bacterial structures, such as the glycocalix, in calcium carbonate crystallization in vitro. We describe the formation of calcite crystals by extracellular polymeric materials, such as exopolysaccharides (EPS) and capsular polysaccharides (CPS) isolated from Bacillus firmus and Nocardia calcarea. Organic matrices were isolated from calcifying bacteria grown on synthetic medium--in the presence or absence of calcium ions--and their effect on calcite precipitation was assessed. Scanning electron microscopy observations and energy dispersive X-ray spectrometry analysis showed that CPS and EPS fractions were involved in calcium carbonate precipitation, not only serving as nucleation sites but also through a direct role in crystal formation. The utilization of different synthetic media, with and without addition of calcium ions, influenced the biofilm production and protein profile of extracellular polymeric materials. Proteins of CPS fractions with a molecular mass between 25 and 70 kDa were overexpressed when calcium ions were present in the medium. This higher level of protein synthesis could be related to the active process of bioprecipitation. PMID:22697480

  10. Antibacterial Activity of Essential Oils and Their Isolated Constituents against Cariogenic Bacteria: A Systematic Review.

    PubMed

    Freires, Irlan Almeida; Denny, Carina; Benso, Bruna; de Alencar, Severino Matias; Rosalen, Pedro Luiz

    2015-01-01

    Dental caries remains the most prevalent and costly oral infectious disease worldwide. Several methods have been employed to prevent this biofilm-dependent disease, including the use of essential oils (EOs). In this systematic review, we discuss the antibacterial activity of EOs and their isolated constituents in view of a potential applicability in novel dental formulations. Seven databases were systematically searched for clinical trials, in situ, in vivo and in vitro studies addressing the topic published up to date. Most of the knowledge in the literature is based on in vitro studies assessing the effects of EOs on caries-related streptococci (mainly Streptococcus mutans) and lactobacilli, and on a limited number of clinical trials. The most promising species with antibacterial potential against cariogenic bacteria are: Achillea ligustica, Baccharis dracunculifolia, Croton cajucara, Cryptomeria japonica, Coriandrum sativum, Eugenia caryophyllata, Lippia sidoides, Ocimum americanum, and Rosmarinus officinalis. In some cases, the major phytochemical compounds determine the biological properties of EOs. Menthol and eugenol were considered outstanding compounds demonstrating an antibacterial potential. Only L. sidoides mouthwash (1%) has shown clinical antimicrobial effects against oral pathogens thus far. This review suggests avenues for further non-clinical and clinical studies with the most promising EOs and their isolated constituents bioprospected worldwide. PMID:25911964

  11. Characterization and in vitro probiotic evaluation of lactic acid bacteria isolated from idli batter.

    PubMed

    Iyer, Bharti K; Singhal, Rekha S; Ananthanarayan, Laxmi

    2013-12-01

    An Indian traditional fermented food, idli batter, was used as a source for isolation of lactic acid bacteria (LAB). A total of 15 LAB strains were isolated on the basis of their Gram nature and catalase activity. Of these, one lactobacilli strain and one lactococci strain which showed antimicrobial activity were identified using biochemical characterization, sugar utilization and molecular sequencing. The microbes, labeled as IB-1 (Lactobacillus plantarum) and IB-2 (Lactococcus lactis) were tested for their in vitro tolerance to bile salts, resistance to low pH values and acidifying activity. Both the strains showed good viability (IB1- 58.11%; IB2- 60.84%) when exposed to high bile salt concentration (2%) and acidic pH of ≤pH 3.0 (IB1- 88.13%; IB2- 89.85%). Lactic acid (IB1- 181.93 mM; IB2- 154.44 mM), biomass production (IB1- 0.65; IB2- 0.58 g/l) after 54 h as well as qualitative estimation of β-galactosidase and vitamin B12 production were also studied to check their suitability as an industrially important strain for production of important biomolecules.

  12. Clinically significant anaerobic bacteria isolated from patients in a South African academic hospital: antimicrobial susceptibility testing.

    PubMed

    Naidoo, S; Perovic, O; Richards, G A; Duse, A G

    2011-09-27

    BACKGROUND. Increasing resistance to some antimicrobial agents among anaerobic bacteria has made susceptibility patterns less predictable. METHOD. This was a prospective study of the susceptibility data of anaerobic organisms isolated from clinical specimens from patients with suspected anaerobic infections from June 2005 until February 2007. Specimens were submitted to the microbiology laboratory at Charlotte Maxeke Johannesburg Academic Hospital, where microscopy, culture and susceptibility testing were performed the using E test® strip minimum inhibitory concentration method. Results were interpreted with reference to Clinical and Laboratory Standards Institute guidelines for amoxicillin-clavulanate, clindamycin, metronidazole, penicillin, ertapenem, cefoxitin, ceftriaxone, chloramphenicol and piperacillin-tazobactam. RESULTS. One hundred and eighty anaerobic isolates were submitted from 165 patients. The most active antimicrobial agents were chloramphenicol (100% susceptible), ertapenem (97.2%), piperacillin-tazobactam (99.4%) and amoxicillin-clavulanic acid (96.7%). Less active were metronidazole (89.4%), cefoxitin (85%), clindamycin (81.7%), ceftriaxone (68.3%) and penicillin (33.3%). CONCLUSION. Susceptibility testing should be performed periodically to identify emerging trends in resistance and to modify empirical treatment of anaerobic infections.

  13. Lactic acid bacteria isolated from young calves--characterization and potential as probiotics.

    PubMed

    Maldonado, Natalia C; de Ruiz, Clara Silva; Otero, María Claudia; Sesma, Fernando; Nader-Macías, María Elena

    2012-04-01

    Lactic acid bacteria (LAB) are widely used as probiotics in humans and animals to restore the ecological balance of different mucosa. They help in the physiological functions of newborn calves that are susceptible to a variety of syndromes. The criteria for the selection of strains for the design of probiotic products are not available. Based in the host-specificity of the indigenous microbiota, 96 LAB isolates from faeces and oral cavity of calves were obtained. The surface properties were screened showing a small number of highly hydrophobic or autoagglutinating isolates. Also, a group produced H(2)O(2) and were able to inhibit pathogens, and two strains were bacteriocin-producers. Some grew at very low pH and high bile concentrations. The strains sharing some of the specific properties evaluated were identified genetically, assayed their compatibility and exopolysaccharide production. The results allow going further in the establishment of criteria to select strains to be included in a multi-strain-probiotic-product to be further assayed in animals.

  14. Isolation and characterization of halophilic bacteria and archaea from salt ponds in Hangu Saltworks, Tianjin, China

    NASA Astrophysics Data System (ADS)

    Deng, Yuangao; Xu, Gaochao; Sui, Liying

    2015-07-01

    A total of 26 isolates were obtained from solar salt ponds of different salinities (100, 150, 200, and 250) in Hangu Saltworks Co. Ltd., Tianjin, China. Phylogenetic analysis of 16S rRNA gene sequences indicated that five bacteria genera Halomonas, Salinicoccus, Oceanobacillus, Gracibacillus, and Salimicrobium and one archaea genera Halorubrum were present. The genus Halomonas was predominant with eight strains distributed in a salinity range of 100-200, followed by Halorubrum with six strains in salinity 250. Based on the genus and original sampling salinity, eight bacterial and two archaeal isolates were selected for further morphological, physiological, and biochemical characterization. All of the bacterial strains were moderately halophilic with the optimal salinity for growth being either 50 or 100, while two archaeal strains were extremely halophilic with an optimal growth salinity of 200. Additionally, we put forth strain SM.200-5 as a new candidate Salimicrobium species based on the phylogenic analysis of the 16S rRNA gene sequence and its biochemical characteristics when compared with known related species.

  15. Bacteria isolated from Korean black raspberry vinegar with low biogenic amine production in wine.

    PubMed

    Song, Nho-Eul; Cho, Hyoun-Suk; Baik, Sang-Ho

    2016-01-01

    A high concentration of histamine, one of the biogenic amines (BAs) usually found in fermented foods, can cause undesirable physiological side effects in sensitive humans. The objective of this study is to isolate indigenous Acetobacter strains from naturally fermented Bokbunja vinegar in Korea with reduced histamine production during starter fermentation. Further, we examined its physiological and biochemical properties, including BA synthesis. The obtained strain MBA-77, identified as Acetobacter aceti by 16S rDNA homology and biochemical analysis and named A. aceti MBA-77. A. aceti MBA-77 showed optimal acidity % production at pH 5; the optimal temperature was 25°C. When we prepared and examined the BAs synthesis spectrum during the fermentation process, Bokbunja wine fermented with Saccharomyces cerevisiae showed that the histamine concentration increased from 2.72 of Bokbunja extract to 5.29mg/L and cadaverine and dopamine was decreased to 2.6 and 10.12mg/L, respectively. Bokbunja vinegar prepared by A. aceti MBA-77 as the starter, the histamine concentration of the vinegar preparation step was decreased up to 3.66mg/L from 5.29mg/L in the wine preparation step. To our knowledge, this is the first report to demonstrate acetic acid bacteria isolated from Bokbunja seed vinegar with low spectrum BA and would be useful for wellbeing vinegar preparation. PMID:26991285

  16. Characterization of Gram-negative psychrotrophic bacteria isolated from Italian bulk tank milk.

    PubMed

    Decimo, Marilù; Morandi, Stefano; Silvetti, Tiziana; Brasca, Milena

    2014-10-01

    Eighty psychrotrophic bacterial strains, isolated from different northwest Italian bulk tank milks destined for Grana Padano cheese production, were identified by 16S rRNA gene amplification and partial sequence analysis of the rpoB gene. Pseudomonas spp. were the most commonly occurring contaminants, P. fluorescens being the predominant isolated species, along with Enterobacteriaceae, primarily Serratia marcescens. RAPD-PCR was used to study genetic variability and distinguish closely related strains; a high degree of genetic heterogeneity among the strains was highlighted. All the strains were characterized for their ability to produce proteases, lipases and lecithinases at different temperatures (7, 22, and 30 °C). Forty-one of the psychrotrophic strains were positive for all the enzymatic activities. The highest number of positive strains for all the incubation temperatures was found for lipolytic activity (59), followed by proteolytic (31) and lecithinase (28) activities, and the enzymatic traits varied among the Pseudomonas and Enterobacteriaceae strains. The proteolytic psychrotrophic strains were screened for the presence of the aprX gene, coding for a heat-resistant metalloprotease in Pseudomonas spp. The aprX gene was detected in 19 of 63 Pseudomonas strains, and was widespread in the P. fluorescens strains (14/19). PRATICAL APPLICATION: The study provides new data on the enzymatic activity of Gram-negative psychrotrophic bacteria, useful in developing strategies to control the proteo-lipolytic spoilage of raw and processed milk that causes gelation, off-flavors, and loss of sensory quality and shelf life. PMID:25224662

  17. Antibacterial metabolites synthesized by psychrotrophic bacteria isolated from cold-freshwater environments.

    PubMed

    Barros, Javier; Becerra, José; González, Carlos; Martínez, Miguel

    2013-03-01

    The ability of three psychrotrophic Gram-negative bacilli isolated from Chilean Patagonian cold freshwater rivers to produce bioactive metabolites was evaluated. The strains were isolated from cold waters rivers and identified by their biochemical properties and 16S rRNA gene analysis. The metabolites fractions showing antibacterial activity were obtained by solvent extraction and partially characterized by gas-mass chromatography (GC-MS). Antibacterial activity of the fractions was evaluated by an agar-well diffusion test upon 14 bacterial strains, both Gram positive and Gram negative. Thermal and proteolytic resistances of the antibacterial metabolites fractions were also evaluated. Molecular analysis allows the identification of the three Patagonian strains as Pseudomonas sp. RG-6 (Pseudomonas brenneri 99.6 % identity), Pseudomonas sp. RG-8 (Pseudomonas trivialis 99.6 % identity) and Yersinia sp. RP-3 (Yersinia aldovae 99.5 % identity). These extracts were able to inhibit both Gram-positive and Gram-negative bacteria but not Listeria monocytogenes. The antibacterial activity of the filtrated supernatants was lost at temperatures ≥60 °C, and was not affected by proteinase K treatment. The chemical structure of the active molecule remains to be elucidated, although the GC-MS analysis of the filtrates suggests that compounds like sesquiterpenes derivatives from β-maaliene or δ-selinene could be responsible of this antibacterial activity. Pristine cold freshwater streams showed to be interesting sources of metabolites-producing microorganisms with antibacterial activity.

  18. In vitro activity of gemifloxacin against recent clinical isolates of bacteria in Korea.

    PubMed Central

    Yong, Dong Eun; Cheong, Hee-Jin; Kim, Yang Soo; Park, Yeon Joon; Kim, Woo-Joo; Woo, Jun Hee; Lee, Kyung Won; Kang, Moon Won; Choo, Youn-Sung

    2002-01-01

    Gemifloxacin is an enhanced-affinity fluoroquinolone with broad-spectrum antibacterial activity. In Korea, resistant bacteria are relatively more prevalent than in other industrialized countries. In this study, we studied the in vitro activities of gemifloxacin, gatifloxacin, moxifloxacin, levofloxacin, ciprofloxacin, and other commonly used antimicrobial agents against 1,689 bacterial strains isolated at four Korean university hospitals during 1999-2000. Minimum inhibitory concentrations (MICs) were determined using the agar dilution method of National Committee for Clinical Laboratory Standards. Gemifloxacin had the lowest MICs for the respiratory pathogens: 90% of Streptococcus pneumoniae, Moraxella catarrhalis, and Haemophilus influenzae were inhibited by 0.06, 0.03, and 0.03 mg/L, respectively. Gemifloxacin was more active than the other fluoroquinolones against methicillin-susceptible Staphylococcus aureus, coagulase-negative staphylococci, streptococci, and Enterococcus faecalis. The MIC90s of gemifloxacin for Klebsiella oxytoca, Proteus vulgaris, and non-typhoidal Salmonella spp. were 0.25, 1.0, and 0.12 mg/L, respectively, while those for other Gram-negative bacilli were 4-64 mg/L. In conclusion, gemifloxacin was the most active among the comparative agents against Gram-positive species, including respiratory pathogens isolated in Korea. PMID:12482994

  19. Characterization of Gram-negative psychrotrophic bacteria isolated from Italian bulk tank milk.

    PubMed

    Decimo, Marilù; Morandi, Stefano; Silvetti, Tiziana; Brasca, Milena

    2014-10-01

    Eighty psychrotrophic bacterial strains, isolated from different northwest Italian bulk tank milks destined for Grana Padano cheese production, were identified by 16S rRNA gene amplification and partial sequence analysis of the rpoB gene. Pseudomonas spp. were the most commonly occurring contaminants, P. fluorescens being the predominant isolated species, along with Enterobacteriaceae, primarily Serratia marcescens. RAPD-PCR was used to study genetic variability and distinguish closely related strains; a high degree of genetic heterogeneity among the strains was highlighted. All the strains were characterized for their ability to produce proteases, lipases and lecithinases at different temperatures (7, 22, and 30 °C). Forty-one of the psychrotrophic strains were positive for all the enzymatic activities. The highest number of positive strains for all the incubation temperatures was found for lipolytic activity (59), followed by proteolytic (31) and lecithinase (28) activities, and the enzymatic traits varied among the Pseudomonas and Enterobacteriaceae strains. The proteolytic psychrotrophic strains were screened for the presence of the aprX gene, coding for a heat-resistant metalloprotease in Pseudomonas spp. The aprX gene was detected in 19 of 63 Pseudomonas strains, and was widespread in the P. fluorescens strains (14/19). PRATICAL APPLICATION: The study provides new data on the enzymatic activity of Gram-negative psychrotrophic bacteria, useful in developing strategies to control the proteo-lipolytic spoilage of raw and processed milk that causes gelation, off-flavors, and loss of sensory quality and shelf life.

  20. Corrosion of iron by iodide-oxidizing bacteria isolated from brine in an iodine production facility.

    PubMed

    Wakai, Satoshi; Ito, Kimio; Iino, Takao; Tomoe, Yasuyoshi; Mori, Koji; Harayama, Shigeaki

    2014-10-01

    Elemental iodine is produced in Japan from underground brine (fossil salt water). Carbon steel pipes in an iodine production facility at Chiba, Japan, for brine conveyance were found to corrode more rapidly than those in other facilities. The corroding activity of iodide-containing brine from the facility was examined by immersing carbon steel coupons in "native" and "filter-sterilized" brine samples. The dissolution of iron from the coupons immersed in native brine was threefold to fourfold higher than that in the filter-sterilized brine. Denaturing gradient gel electrophoresis analyses revealed that iodide-oxidizing bacteria (IOBs) were predominant in the coupon-containing native brine samples. IOBs were also detected in a corrosion deposit on the inner surface of a corroded pipe. These results strongly suggested the involvement of IOBs in the corrosion of the carbon steel pipes. Of the six bacterial strains isolated from a brine sample, four were capable of oxidizing iodide ion (I(-)) into molecular iodine (I(2)), and these strains were further phylogenetically classified into two groups. The iron-corroding activity of each of the isolates from the two groups was examined. Both strains corroded iron in the presence of potassium iodide in a concentration-dependent manner. This is the first report providing direct evidence that IOBs are involved in iron corrosion. Further, possible mechanisms by which IOBs corrode iron are discussed.

  1. Characterization and in vitro probiotic evaluation of lactic acid bacteria isolated from idli batter.

    PubMed

    Iyer, Bharti K; Singhal, Rekha S; Ananthanarayan, Laxmi

    2013-12-01

    An Indian traditional fermented food, idli batter, was used as a source for isolation of lactic acid bacteria (LAB). A total of 15 LAB strains were isolated on the basis of their Gram nature and catalase activity. Of these, one lactobacilli strain and one lactococci strain which showed antimicrobial activity were identified using biochemical characterization, sugar utilization and molecular sequencing. The microbes, labeled as IB-1 (Lactobacillus plantarum) and IB-2 (Lactococcus lactis) were tested for their in vitro tolerance to bile salts, resistance to low pH values and acidifying activity. Both the strains showed good viability (IB1- 58.11%; IB2- 60.84%) when exposed to high bile salt concentration (2%) and acidic pH of ≤pH 3.0 (IB1- 88.13%; IB2- 89.85%). Lactic acid (IB1- 181.93 mM; IB2- 154.44 mM), biomass production (IB1- 0.65; IB2- 0.58 g/l) after 54 h as well as qualitative estimation of β-galactosidase and vitamin B12 production were also studied to check their suitability as an industrially important strain for production of important biomolecules. PMID:24426023

  2. Lactic Acid Bacteria Isolated from Bovine Mammary Microbiota: Potential Allies against Bovine Mastitis.

    PubMed

    Bouchard, Damien S; Seridan, Bianca; Saraoui, Taous; Rault, Lucie; Germon, Pierre; Gonzalez-Moreno, Candelaria; Nader-Macias, Fatima M E; Baud, Damien; François, Patrice; Chuat, Victoria; Chain, Florian; Langella, Philippe; Nicoli, Jacques; Le Loir, Yves; Even, Sergine

    2015-01-01

    Bovine mastitis is a costly disease in dairy cattle worldwide. As of yet, the control of bovine mastitis is mostly based on prevention by thorough hygienic procedures during milking. Additional strategies include vaccination and utilization of antibiotics. Despite these measures, mastitis is not fully under control, thus prompting the need for alternative strategies. The goal of this study was to isolate autochthonous lactic acid bacteria (LAB) from bovine mammary microbiota that exhibit beneficial properties that could be used for mastitis prevention and/or treatment. Sampling of the teat canal led to the isolation of 165 isolates, among which a selection of ten non-redundant LAB strains belonging to the genera Lactobacillus and Lactococcus were further characterized with regard to several properties: surface properties (hydrophobicity, autoaggregation); inhibition potential of three main mastitis pathogens, Staphylococcus aureus, Escherichia coli and Streptococcus uberis; colonization capacities of bovine mammary epithelial cells (bMEC); and immunomodulation properties. Three strains, Lactobacillus brevis 1595 and 1597 and Lactobacillus plantarum 1610, showed high colonization capacities and a medium surface hydrophobicity. These strains are good candidates to compete with pathogens for mammary gland colonization. Moreover, nine strains exhibited anti-inflammatory properties, as illustrated by the lower IL-8 secretion by E. coli-stimulated bMEC in the presence of these LAB. Full genome sequencing of five candidate strains allowed to check for undesirable genetic elements such as antibiotic resistance genes and to identify potential bacterial determinants involved in the beneficial properties. This large screening of beneficial properties while checking for undesirable genetic markers allowed the selection of promising candidate LAB strains from bovine mammary microbiota for the prevention and/or treatment of bovine mastitis.

  3. Lactic Acid Bacteria Isolated from Bovine Mammary Microbiota: Potential Allies against Bovine Mastitis

    PubMed Central

    Saraoui, Taous; Rault, Lucie; Germon, Pierre; Gonzalez-Moreno, Candelaria; Nader-Macias, Fatima M. E.; Baud, Damien; François, Patrice; Chuat, Victoria; Chain, Florian; Langella, Philippe; Nicoli, Jacques; Le Loir, Yves; Even, Sergine

    2015-01-01

    Bovine mastitis is a costly disease in dairy cattle worldwide. As of yet, the control of bovine mastitis is mostly based on prevention by thorough hygienic procedures during milking. Additional strategies include vaccination and utilization of antibiotics. Despite these measures, mastitis is not fully under control, thus prompting the need for alternative strategies. The goal of this study was to isolate autochthonous lactic acid bacteria (LAB) from bovine mammary microbiota that exhibit beneficial properties that could be used for mastitis prevention and/or treatment. Sampling of the teat canal led to the isolation of 165 isolates, among which a selection of ten non-redundant LAB strains belonging to the genera Lactobacillus and Lactococcus were further characterized with regard to several properties: surface properties (hydrophobicity, autoaggregation); inhibition potential of three main mastitis pathogens, Staphylococcus aureus, Escherichia coli and Streptococcus uberis; colonization capacities of bovine mammary epithelial cells (bMEC); and immunomodulation properties. Three strains, Lactobacillus brevis 1595 and 1597 and Lactobacillus plantarum 1610, showed high colonization capacities and a medium surface hydrophobicity. These strains are good candidates to compete with pathogens for mammary gland colonization. Moreover, nine strains exhibited anti-inflammatory properties, as illustrated by the lower IL-8 secretion by E. coli-stimulated bMEC in the presence of these LAB. Full genome sequencing of five candidate strains allowed to check for undesirable genetic elements such as antibiotic resistance genes and to identify potential bacterial determinants involved in the beneficial properties. This large screening of beneficial properties while checking for undesirable genetic markers allowed the selection of promising candidate LAB strains from bovine mammary microbiota for the prevention and/or treatment of bovine mastitis. PMID:26713450

  4. Characterization, Identification and Application of Lactic Acid Bacteria Isolated from Forage Paddy Rice Silage

    PubMed Central

    Ni, Kuikui; Wang, Yanping; Li, Dongxia; Cai, Yimin; Pang, Huili

    2015-01-01

    There has been growing interest to develop forage rice as a new feed resource for livestock. This study was to characterize the natural population of lactic acid bacteria (LAB) and select potentially excellent strains for paddy rice silage preparation in China. One hundred and twenty-six strains were isolated and screened from paddy rice silage prepared using a small-scale fermentation system, and ninety-nine of these isolates were considered to be LAB based on their Gram-positive and catalase-negative morphology and the production of most of their metabolic products as lactic acid. These isolates were divided into eight groups (A-H) on the basis of their morphological and biochemical characteristics. The Group A to H strains were identified as Lactobacillus (L.) plantarum subsp. plantarum (species ratio: 8.1%), L. casei (5.1%), Leuconostoc (Ln.) pseudomesenteroides (11.1%), Pediococcus (P.) pentosaceus (24.2%), Enterococcus (E.) mundtii (12.1%), Lactococcus (Lc.) garvieae (15.2%), E. faecium (9.1%) and Lc. lactis subsp. lactis (15.2%) based on sequence analyses of their 16S rRNA and recA genes. P. pentosaceus was the most abundant member of the LAB population in the paddy rice silage. A selected strain, namely L. casei R 465, was found to be able to grow under low pH conditions and to improve the silage quality with low pH and a relatively high content of lactic acid. This study demonstrated that forage paddy rice silage contains abundant LAB species and its silage can be well preserved by inoculation with LAB, and that strain R 465 can be a potentially excellent inoculant for paddy rice silage. PMID:25803578

  5. Identification and Antimicrobial Resistance of Bacteria Isolated from Probiotic Products Used in Shrimp Culture.

    PubMed

    Noor Uddin, Gazi Md; Larsen, Marianne Halberg; Christensen, Henrik; Aarestrup, Frank M; Phu, Tran Minh; Dalsgaard, Anders

    2015-01-01

    Probiotics are increasingly used in aquaculture to control diseases and improve feed digestion and pond water quality; however, little is known about the antimicrobial resistance properties of such probiotic bacteria and to what extent they may contribute to the development of bacterial resistance in aquaculture ponds. Concerns have been raised that the declared information on probiotic product labels are incorrect and information on bacterial composition are often missing. We therefore evaluated seven probiotics commonly used in Vietnamese shrimp culture for their bacterial species content, phenotypic antimicrobial resistance and associated transferable resistance genes. The bacterial species was established by 16S rRNA sequence analysis of 125 representative bacterial isolates. MIC testing was done for a range of antimicrobials and whole genome sequencing of six multiple antimicrobial resistant Bacillus spp. used to identify resistance genes and genetic elements associated with horizontal gene transfer. Thirteen bacterial species declared on the probiotic products could not be identified and 11 non-declared Bacillus spp. were identified. Although our culture-based isolation and identification may have missed a few bacterial species present in the tested products this would represent minor bias, but future studies may apply culture independent identification methods like pyro sequencing. Only 6/60 isolates were resistant to more than four antimicrobials and whole genome sequencing showed that they contained macrolide (ermD), tetracycline (tetL), phenicol (fexA) and trimethoprim (dfrD, dfrG and dfrK) resistance genes, but not known structures associated with horizontal gene transfer. Probiotic bacterial strains used in Vietnamese shrimp culture seem to contribute with very limited types and numbers of resistance genes compared to the naturally occurring bacterial species in aquaculture environments. Approval procedures of probiotic products must be strengthened

  6. Lactic Acid Bacteria Isolated from Bovine Mammary Microbiota: Potential Allies against Bovine Mastitis.

    PubMed

    Bouchard, Damien S; Seridan, Bianca; Saraoui, Taous; Rault, Lucie; Germon, Pierre; Gonzalez-Moreno, Candelaria; Nader-Macias, Fatima M E; Baud, Damien; François, Patrice; Chuat, Victoria; Chain, Florian; Langella, Philippe; Nicoli, Jacques; Le Loir, Yves; Even, Sergine

    2015-01-01

    Bovine mastitis is a costly disease in dairy cattle worldwide. As of yet, the control of bovine mastitis is mostly based on prevention by thorough hygienic procedures during milking. Additional strategies include vaccination and utilization of antibiotics. Despite these measures, mastitis is not fully under control, thus prompting the need for alternative strategies. The goal of this study was to isolate autochthonous lactic acid bacteria (LAB) from bovine mammary microbiota that exhibit beneficial properties that could be used for mastitis prevention and/or treatment. Sampling of the teat canal led to the isolation of 165 isolates, among which a selection of ten non-redundant LAB strains belonging to the genera Lactobacillus and Lactococcus were further characterized with regard to several properties: surface properties (hydrophobicity, autoaggregation); inhibition potential of three main mastitis pathogens, Staphylococcus aureus, Escherichia coli and Streptococcus uberis; colonization capacities of bovine mammary epithelial cells (bMEC); and immunomodulation properties. Three strains, Lactobacillus brevis 1595 and 1597 and Lactobacillus plantarum 1610, showed high colonization capacities and a medium surface hydrophobicity. These strains are good candidates to compete with pathogens for mammary gland colonization. Moreover, nine strains exhibited anti-inflammatory properties, as illustrated by the lower IL-8 secretion by E. coli-stimulated bMEC in the presence of these LAB. Full genome sequencing of five candidate strains allowed to check for undesirable genetic elements such as antibiotic resistance genes and to identify potential bacterial determinants involved in the beneficial properties. This large screening of beneficial properties while checking for undesirable genetic markers allowed the selection of promising candidate LAB strains from bovine mammary microbiota for the prevention and/or treatment of bovine mastitis. PMID:26713450

  7. Genomics and Ecophysiology of Heterotrophic Nitrogen-Fixing Bacteria Isolated from Estuarine Surface Water

    PubMed Central

    Bentzon-Tilia, Mikkel; Severin, Ina; Hansen, Lars H.

    2015-01-01

    ABSTRACT The ability to reduce atmospheric nitrogen (N2) to ammonia, known as N2 fixation, is a widely distributed trait among prokaryotes that accounts for an essential input of new N to a multitude of environments. Nitrogenase reductase gene (nifH) composition suggests that putative N2-fixing heterotrophic organisms are widespread in marine bacterioplankton, but their autecology and ecological significance are unknown. Here, we report genomic and ecophysiology data in relation to N2 fixation by three environmentally relevant heterotrophic bacteria isolated from Baltic Sea surface water: Pseudomonas stutzeri strain BAL361 and Raoultella ornithinolytica strain BAL286, which are gammaproteobacteria, and Rhodopseudomonas palustris strain BAL398, an alphaproteobacterium. Genome sequencing revealed that all were metabolically versatile and that the gene clusters encoding the N2 fixation complex varied in length and complexity between isolates. All three isolates could sustain growth by N2 fixation in the absence of reactive N, and this fixation was stimulated by low concentrations of oxygen in all three organisms (≈4 to 40 µmol O2 liter−1). P. stutzeri BAL361 did, however, fix N at up to 165 µmol O2 liter−1, presumably accommodated through aggregate formation. Glucose stimulated N2 fixation in general, and reactive N repressed N2 fixation, except that ammonium (NH4+) stimulated N2 fixation in R. palustris BAL398, indicating the use of nitrogenase as an electron sink. The lack of correlations between nitrogenase reductase gene expression and ethylene (C2H4) production indicated tight posttranscriptional-level control. The N2 fixation rates obtained suggested that, given the right conditions, these heterotrophic diazotrophs could contribute significantly to in situ rates. PMID:26152586

  8. Identification and Antimicrobial Resistance of Bacteria Isolated from Probiotic Products Used in Shrimp Culture.

    PubMed

    Noor Uddin, Gazi Md; Larsen, Marianne Halberg; Christensen, Henrik; Aarestrup, Frank M; Phu, Tran Minh; Dalsgaard, Anders

    2015-01-01

    Probiotics are increasingly used in aquaculture to control diseases and improve feed digestion and pond water quality; however, little is known about the antimicrobial resistance properties of such probiotic bacteria and to what extent they may contribute to the development of bacterial resistance in aquaculture ponds. Concerns have been raised that the declared information on probiotic product labels are incorrect and information on bacterial composition are often missing. We therefore evaluated seven probiotics commonly used in Vietnamese shrimp culture for their bacterial species content, phenotypic antimicrobial resistance and associated transferable resistance genes. The bacterial species was established by 16S rRNA sequence analysis of 125 representative bacterial isolates. MIC testing was done for a range of antimicrobials and whole genome sequencing of six multiple antimicrobial resistant Bacillus spp. used to identify resistance genes and genetic elements associated with horizontal gene transfer. Thirteen bacterial species declared on the probiotic products could not be identified and 11 non-declared Bacillus spp. were identified. Although our culture-based isolation and identification may have missed a few bacterial species present in the tested products this would represent minor bias, but future studies may apply culture independent identification methods like pyro sequencing. Only 6/60 isolates were resistant to more than four antimicrobials and whole genome sequencing showed that they contained macrolide (ermD), tetracycline (tetL), phenicol (fexA) and trimethoprim (dfrD, dfrG and dfrK) resistance genes, but not known structures associated with horizontal gene transfer. Probiotic bacterial strains used in Vietnamese shrimp culture seem to contribute with very limited types and numbers of resistance genes compared to the naturally occurring bacterial species in aquaculture environments. Approval procedures of probiotic products must be strengthened

  9. Characterization, identification and application of lactic Acid bacteria isolated from forage paddy rice silage.

    PubMed

    Ni, Kuikui; Wang, Yanping; Li, Dongxia; Cai, Yimin; Pang, Huili

    2015-01-01

    There has been growing interest to develop forage rice as a new feed resource for livestock. This study was to characterize the natural population of lactic acid bacteria (LAB) and select potentially excellent strains for paddy rice silage preparation in China. One hundred and twenty-six strains were isolated and screened from paddy rice silage prepared using a small-scale fermentation system, and ninety-nine of these isolates were considered to be LAB based on their Gram-positive and catalase-negative morphology and the production of most of their metabolic products as lactic acid. These isolates were divided into eight groups (A-H) on the basis of their morphological and biochemical characteristics. The Group A to H strains were identified as Lactobacillus (L.) plantarum subsp. plantarum (species ratio: 8.1%), L. casei (5.1%), Leuconostoc (Ln.) pseudomesenteroides (11.1%), Pediococcus (P.) pentosaceus (24.2%), Enterococcus (E.) mundtii (12.1%), Lactococcus (Lc.) garvieae (15.2%), E. faecium (9.1%) and Lc. lactis subsp. lactis (15.2%) based on sequence analyses of their 16S rRNA and recA genes. P. pentosaceus was the most abundant member of the LAB population in the paddy rice silage. A selected strain, namely L. casei R 465, was found to be able to grow under low pH conditions and to improve the silage quality with low pH and a relatively high content of lactic acid. This study demonstrated that forage paddy rice silage contains abundant LAB species and its silage can be well preserved by inoculation with LAB, and that strain R 465 can be a potentially excellent inoculant for paddy rice silage. PMID:25803578

  10. Identification and Antimicrobial Resistance of Bacteria Isolated from Probiotic Products Used in Shrimp Culture

    PubMed Central

    Noor Uddin, Gazi Md.; Larsen, Marianne Halberg; Christensen, Henrik; Aarestrup, Frank M.; Phu, Tran Minh; Dalsgaard, Anders

    2015-01-01

    Probiotics are increasingly used in aquaculture to control diseases and improve feed digestion and pond water quality; however, little is known about the antimicrobial resistance properties of such probiotic bacteria and to what extent they may contribute to the development of bacterial resistance in aquaculture ponds. Concerns have been raised that the declared information on probiotic product labels are incorrect and information on bacterial composition are often missing. We therefore evaluated seven probiotics commonly used in Vietnamese shrimp culture for their bacterial species content, phenotypic antimicrobial resistance and associated transferable resistance genes. The bacterial species was established by 16S rRNA sequence analysis of 125 representative bacterial isolates. MIC testing was done for a range of antimicrobials and whole genome sequencing of six multiple antimicrobial resistant Bacillus spp. used to identify resistance genes and genetic elements associated with horizontal gene transfer. Thirteen bacterial species declared on the probiotic products could not be identified and 11 non-declared Bacillus spp. were identified. Although our culture-based isolation and identification may have missed a few bacterial species present in the tested products this would represent minor bias, but future studies may apply culture independent identification methods like pyro sequencing. Only 6/60 isolates were resistant to more than four antimicrobials and whole genome sequencing showed that they contained macrolide (ermD), tetracycline (tetL), phenicol (fexA) and trimethoprim (dfrD, dfrG and dfrK) resistance genes, but not known structures associated with horizontal gene transfer. Probiotic bacterial strains used in Vietnamese shrimp culture seem to contribute with very limited types and numbers of resistance genes compared to the naturally occurring bacterial species in aquaculture environments. Approval procedures of probiotic products must be strengthened

  11. Screening and identification of newly isolated cellulose-degrading bacteria from the gut of xylophagous termite Microcerotermes diversus (Silvestri).

    PubMed

    Pourramezan, Z; Ghezelbash, G R; Romani, B; Ziaei, S; Hedayatkhah, A

    2012-01-01

    The aim of the present study was to isolate and characterize the cellulose-degrading bacteria from the gut of the local termite, Microcerotermes diversus (Silvestri), inhabiting the Khuzestan province of Iran. The microorganisms capable of growing in the liquid medium containing cellulose as the only source of carbon were isolated and their cellulolytic activity on CMC-containing media was confirmed by the congo red clearing zone assay. The isolates were identified based on biochemical characteristics and the phylogenetic analysis of 16S rRNA gene fragments. The results of the present study show that three cellulose-degrading bacteria isolated from local termite guts belonged to the genera Acinetobacter, Pseudomonas and Staphylococcus and four cellulose-degrading bacteria belonged to Enterobacteriaceae and Bacillaceae families. Several isolates recovered from separate termite Microcerotermes diversus samples closely clustered in phylogenetic trees indicating high similarity and the abundance of particular cellulolytic strains. Bacillus B5B and Acinetobacter L9B hydrolyzed cellulose faster than the other isolates (with CMCase activity of 1.47 U/mL and 1.22 U/mL, respectively). The stability of CMCase produced by Bacillus B5B over a broad range of pH and high temperature indicated that the enzyme may be of great commercial value.

  12. Detection and isolation of chloromethane-degrading bacteria from the Arabidopsis thaliana phyllosphere, and characterization of chloromethane utilization genes.

    PubMed

    Nadalig, Thierry; Farhan Ul Haque, Muhammad; Roselli, Sandro; Schaller, Hubert; Bringel, Françoise; Vuilleumier, Stéphane

    2011-08-01

    Chloromethane gas is produced naturally in the phyllosphere, the compartment defined as the aboveground parts of vegetation, which hosts a rich bacterial flora. Chloromethane may serve as a growth substrate for specialized aerobic methylotrophic bacteria, which have been isolated from soil and water environments, and use cmu genes for chloromethane utilization. Evidence for the presence of chloromethane-degrading bacteria on the leaf surfaces of Arabidopsis thaliana was obtained by specific quantitative PCR of the cmuA gene encoding the two-domain methyltransferase corrinoid protein of chloromethane dehalogenase. Bacterial strains were isolated on a solid mineral medium with chloromethane as the sole carbon source from liquid mineral medium enrichment cultures inoculated with leaves of A. thaliana. Restriction analysis-based genotyping of cmuA PCR products was used to evaluate the diversity of chloromethane-degrading bacteria during enrichment and after strain isolation. The isolates obtained, affiliated to the genus Hyphomicrobium based on their 16S rRNA gene sequence and the presence of characteristic hyphae, dehalogenate chloromethane, and grow in a liquid culture with chloromethane as the sole carbon and energy source. The cmu genes of these isolates were analysed using new PCR primers, and their sequences were compared with those of previously reported aerobic chloromethane-degrading strains. The three isolates featured a colinear cmuBCA gene arrangement similar to that of all previously characterized strains, except Methylobacterium extorquens CM4 of known genome sequence. PMID:21545604

  13. An efficient screening method for the isolation of heterotrophic bacteria influencing growth of diatoms under photoautotrophic conditions.

    PubMed

    Zecher, Karsten; Jagmann, Nina; Seemann, Philipp; Philipp, Bodo

    2015-12-01

    Interactions between photoautotrophic diatoms and heterotrophic bacteria are important for the biogeochemical C-cycle in the oceans. Additionally, biofilms formed by diatoms and bacteria are the initiating step of biofouling processes, which causes high costs in shipping. Despite this ecological and economical importance, the knowledge about biochemical and molecular mechanisms underlying these interkingdom interactions is relatively small. For analyzing these mechanisms, laboratory model systems are required. In this study, an efficient screening method for isolating bacteria influencing photoautotrophic diatom growth was established. First, diatom cultures of Phaeodactylum tricornutum and Thalassiosira pseudonana were made axenic by applying β-lactam antibiotics. Second, a non-invasive method for measuring growth of multiple parallel diatom cultures by chlorophyll fluorescence was established. This method allowed semi-quantitative chlorophyll determination of cultures with up to 3 μg (chlorophyll) ml(-1). Axenic diatom cultures were then used for enriching bacteria and led to the isolation of 24 strains influencing growth of both diatom strains in various ways. For example, Rheinheimera sp. strain Tn16 inhibited growth of T. pseudonana, while it stimulated growth and cell aggregation of P. tricornutum. Thus, this screening method is appropriate for isolating heterotrophic bacteria showing different interactions with different diatom species ranging from synergistic to antagonistic. In consecutive applications, this method will be useful to screen for bacterial mutants with altered phenotypes regarding the influence on diatom growth.

  14. Draft Genome Sequences of Gluconobacter cerinus CECT 9110 and Gluconobacter japonicus CECT 8443, Acetic Acid Bacteria Isolated from Grape Must

    PubMed Central

    Sainz, Florencia

    2016-01-01

    We report here the draft genome sequences of Gluconobacter cerinus strain CECT9110 and Gluconobacter japonicus CECT8443, acetic acid bacteria isolated from grape must. Gluconobacter species are well known for their ability to oxidize sugar alcohols into the corresponding acids. Our objective was to select strains to oxidize effectively d-glucose. PMID:27365351

  15. "Paraffin wax-overlay of pour plate", a method for the isolation and enumeration of purple non-sulfur bacteria.

    PubMed

    Archana, A; Sasikala, Ch; Ramana, Ch V; Arunasri, K

    2004-12-01

    A modification of pour plate technique with an overlay of wax was used for isolation and enumeration of purple non-sulfur bacteria (PNSB) with equal efficiency as that of agar shake culture. The total count of PNSB ranged from 10(5)-10(8) CFU g dry soil(-1) and belonged to the genera of Rhodobacter, Rhodopseudomonas, Rhodocista and Rubrivivax.

  16. High prevalence of multidrug-tolerant bacteria and associated antimicrobial resistance genes isolated from ornamental fish and their carriage water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objectives: The aim of the study was to assess the extent to which ornamental fish and their carriage water harbour antibiotic resistant bacteria and associated antibiotic resistance genes. Methods: 129 Aeromonas spp. isolated from warm water and coldwater ornamental fish species were screened for r...

  17. Resistance to ceftriaxone and other beta-lactams in bacteria isolated in the community. The Vigil'Roc Study Group.

    PubMed Central

    Goldstein, F W; Péan, Y; Gertner, J

    1995-01-01

    The incidence of bacterial species and their susceptibilities to ceftriaxone and other beta-lactams from patients with community-acquired infections were evaluated in a multicenter study over a 4-month period. A total of 5,768 bacterial isolates were classified according to whether the patient had been previously hospitalized or had received antibiotic treatment. The most relevant findings were the presence of 33.8% penicillin-resistant Streptococcus pneumoniae isolates, 25% beta-lactamase-producing Haemophilus influenzae isolates, and 36.4% amoxicillin-resistant Escherichia coli isolates. All of these bacteria were fully susceptible to ceftriaxone. Nosocomial multiply-resistant bacteria, and particularly methicillin-resistant S. aureus, were found, as expected, at a higher frequency among previously hospitalized patients. However, such bacteria may be present in the community; their incidence is high in particular clinical settings, and such bacteria should be considered when one is choosing a first-line therapy for the treatment of severe infections. PMID:8585736

  18. Spore-forming halophilic bacteria isolated from Arctic terrains: Implications for long-range transportation of microorganisms

    NASA Astrophysics Data System (ADS)

    Yukimura, Kise; Nakai, Ryosuke; Kohshima, Shiro; Uetake, Jun; Kanda, Hiroshi; Naganuma, Takeshi

    2009-11-01

    Organisms living in the Arctic terrains such as Greenland have to deal with low temperature conditions. The mechanisms by which bacteria resist to low temperature are largely unknown; however, a well-known survival strategy of the microorganisms inhabiting the Arctic is spore forming. Moreover, halophilic bacteria are often resistant to various stresses. We have attempted isolation of spore-forming halophilic bacteria from Arctic terrains. We isolated 10 strains of spore-forming halophilic bacteria from the samples collected from a glacial moraine in Qaanaaq, Greenland in July 2007. Identification based on 16S rRNA gene sequence similarities showed that the isolates were closely related to the Oceanobacillus, Ornithinibacillus, Virgibacillus, Gracilibacillus, and Bacillus genera. In addition, the 16S rRNA sequences of some isolates were extremely similar to those of strains from the desert sand in China (100% identity, near full length), the source of the so-called “yellow dust.” Previous research indicated that yellow dust had been transported to Greenland by the wind. Our research implies the long-range transportation of these microorganisms to locations such as the Arctic.

  19. Endophytic Bacteria Isolated from Common Bean (Phaseolus vulgaris) Exhibiting High Variability Showed Antimicrobial Activity and Quorum Sensing Inhibition.

    PubMed

    Lopes, Ralf Bruno Moura; Costa, Leonardo Emanuel de Oliveira; Vanetti, Maria Cristina Dantas; de Araújo, Elza Fernandes; de Queiroz, Marisa Vieira

    2015-10-01

    Endophytic bacteria play a key role in the biocontrol of phytopathogenic microorganisms. In this study, genotypic diversity was analyzed via repetitive element PCR (rep-PCR) of endophytic isolates of the phylum Actinobacteria that were previously collected from leaves of cultivars of common bean (Phaseolus vulgaris). Considerable variability was observed, which has not been reported previously for this phylum of endophytic bacteria of the common bean. Furthermore, the ethanol extracts from cultures of various isolates inhibited the growth of pathogenic bacteria in vitro, especially Gram-positive pathogens. Extracts from cultures of Microbacterium testaceum BAC1065 and BAC1093, which were both isolated from the 'Talismã' cultivar, strongly inhibited most of the pathogenic bacteria tested. Bean endophytic bacteria were also demonstrated to have the potential to inhibit the quorum sensing of Gram-negative bacteria. This mechanism may regulate the production of virulence factors in pathogens. The ability to inhibit quorum sensing has also not been reported previously for endophytic microorganisms of P. vulgaris. Furthermore, M. testaceum with capacity to inhibit quorum sensing appears to be widespread in common bean. The genomic profiles of M. testaceum were also analyzed via pulsed-field gel electrophoresis, and greater differentiation was observed using this method than rep-PCR; in general, no groups were formed based on the cultivar of origin. This study showed for the first time that endophytic bacteria from common bean plants exhibit high variability and may be useful for the development of strategies for the biological control of diseases in this important legume plant.

  20. Endophytic Bacteria Isolated from Common Bean (Phaseolus vulgaris) Exhibiting High Variability Showed Antimicrobial Activity and Quorum Sensing Inhibition.

    PubMed

    Lopes, Ralf Bruno Moura; Costa, Leonardo Emanuel de Oliveira; Vanetti, Maria Cristina Dantas; de Araújo, Elza Fernandes; de Queiroz, Marisa Vieira

    2015-10-01

    Endophytic bacteria play a key role in the biocontrol of phytopathogenic microorganisms. In this study, genotypic diversity was analyzed via repetitive element PCR (rep-PCR) of endophytic isolates of the phylum Actinobacteria that were previously collected from leaves of cultivars of common bean (Phaseolus vulgaris). Considerable variability was observed, which has not been reported previously for this phylum of endophytic bacteria of the common bean. Furthermore, the ethanol extracts from cultures of various isolates inhibited the growth of pathogenic bacteria in vitro, especially Gram-positive pathogens. Extracts from cultures of Microbacterium testaceum BAC1065 and BAC1093, which were both isolated from the 'Talismã' cultivar, strongly inhibited most of the pathogenic bacteria tested. Bean endophytic bacteria were also demonstrated to have the potential to inhibit the quorum sensing of Gram-negative bacteria. This mechanism may regulate the production of virulence factors in pathogens. The ability to inhibit quorum sensing has also not been reported previously for endophytic microorganisms of P. vulgaris. Furthermore, M. testaceum with capacity to inhibit quorum sensing appears to be widespread in common bean. The genomic profiles of M. testaceum were also analyzed via pulsed-field gel electrophoresis, and greater differentiation was observed using this method than rep-PCR; in general, no groups were formed based on the cultivar of origin. This study showed for the first time that endophytic bacteria from common bean plants exhibit high variability and may be useful for the development of strategies for the biological control of diseases in this important legume plant. PMID:26202846

  1. Production of rhamnolipids and diesel oil degradation by bacteria isolated from soil contaminated by petroleum.

    PubMed

    Leite, Giuseppe G F; Figueirôa, Juciane V; Almeida, Thiago C M; Valões, Jaqueline L; Marques, Walber F; Duarte, Maria D D C; Gorlach-Lira, Krystyna

    2016-03-01

    Biosurfactants are microbial secondary metabolites. The most studied are rhamnolipids, which decrease the surface tension and have emulsifying capacity. In this study, the production of biosurfactants, with emphasis on rhamnolipids, and diesel oil degradation by 18 strains of bacteria isolated from waste landfill soil contaminated by petroleum was analyzed. Among the studied bacteria, gram-positive endospore forming rods (39%), gram positive rods without endospores (17%), and gram-negative rods (44%) were found. The following methods were used to test for biosurfactant production: oil spreading, emulsification, and hemolytic activity. All strains showed the ability to disperse the diesel oil, while 77% and 44% of the strains showed hemolysis and emulsification of diesel oil, respectively. Rhamnolipids production was observed in four strains that were classified on the basis of the 16S rRNA sequences as Pseudomonas aeruginosa. Only those strains showed the rhlAB gene involved in rhamnolipids synthesis, and antibacterial activity against Escherichia coli, P. aeruginosa, Staphylococcus aureus, Bacillus cereus, Erwinia carotovora, and Ralstonia solanacearum. The highest production of rhamnolipids was 565.7 mg/L observed in mineral medium containing olive oil (pH 8). With regard to the capacity to degrade diesel oil, it was observed that 7 strains were positive in reduction of the dye 2,6-dichlorophenolindophenol (2,6-DCPIP) while 16 had the gene alkane mono-oxygenase (alkB), and the producers of rhamnolipids were positive in both tests. Several bacterial strains have shown high potential to be explored further for bioremediation purposes due to their simultaneous ability to emulsify, disperse, and degrade diesel oil. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 32:262-270, 2016. PMID:26588432

  2. The establishment of resistance phenotypes for bacteria isolated from outpatients in urine cultures.

    PubMed

    Zugravu, Roxana; Licker, Monica; Berceanu-Văduva, Delia; Rădulescu, Matilda; Adămuţ, Marcela; Dragomirescu, Liliana; Branea, Dorina; Hogea, Elena; Muntean, Delia; Mihaela, Diana Popa; Moldovan, Roxana; Loredana, Gabriela Popa

    2006-01-01

    From 1911 outpatients, who addressed a Timişoara private clinical laboratory, from January to December 2005, we collected 1,889 urine cultures, 431 being positive. Bacteria identification was generally done using morphological, cultural, biochemical characters and pathogenicity tests. Sensitivity testing to antimicrobial medical drugs was done by using the classical diffusion Kirby-Bauer method and the automatic analyzer Osiris, also. The main bacteria involved in the etiology of these infections were represented by Enterobacteriaceae, head of the list being Escherichia coli (81.21%), followed by Klebsiella pneumoniae (8.35%) and Proteus mirabilis (3.02%). We also isolated Gram positive cocci (in a much smaller proportion), mainly represented by Enterococcus faecalis (1.16%), Staphylococcus aureus (0.93%), Streptococcus agalactiae, and also Gram negative non-fermentative bacilli, such as Pseudomonas aeruginosa (0.93%) or Acinetobacter baumanii (0.23%). As soon as we performed the sensitivity tests, we divided them in resistance phenotypes: Most of the Enterobacteriaceae were integrated in the wild phenotype, followed by the penicillinase producing phenotype. An E. coli strain (0.29%) and 3 Klebsiella pneumoniae strains (8.33%) were integrated in the large spectrum, multidrug resistant, beta-lactamase producing phenotype, also associated with resistance to fluoroquinolones and aminoglycosides; Non-fermentative bacilli did not present special resistance problems, the four Pseudomonas aeruginosa strains were integrated in the wild phenotype (secreting induced chromosomal cephalosporinase). As for Staphylococcus aureus it was identified a strain having fluoroquinolone resistance, two strains secreting penicillinase and having a K (Nm) phenotype and a strain secreting penicillinase only. Antibiotic resistance represents a major concern for patients, physicians, healthcare managers, and policymakers. The use of antibiotics is closely linked with the development of

  3. Comparison of identification systems for psychrotrophic bacteria isolated from raw bovine milk.

    PubMed

    Vithanage, Nuwan R; Yeager, Thomas R; Jadhav, Snehal R; Palombo, Enzo A; Datta, Nivedita

    2014-10-17

    spoilage bacteria. The Biolog system is suitable for the identification of Gram negative spoilage bacteria, while MALDI-TOF MS and API systems are suitable for the identification of Gram positive spoilage bacteria isolated from raw milk. The commercial systems used in this study have been developed and extensively used for the identification of clinical microbes but only a limited number of studies used those systems to identify the environmental microorganisms that often contaminate raw milk. Therefore, comparison of those systems for the identification of spoilage microbes in raw milk would provide better understanding of their suitability for routine dairy microbiology and more extensive dairy research. PMID:25113043

  4. Isolation and characterization of novel iron-oxidizing bacteria that grow at circumneutral pH.

    PubMed Central

    Emerson, D; Moyer, C

    1997-01-01

    A gel-stabilized gradient method that employed opposing gradients of Fe2+ and O2 was used to isolate and characterize two new Fe-oxidizing bacteria from a neutral pH, Fe(2+)-containing groundwater in Michigan. Two separate enrichment cultures were obtained, and in each the cells grew in a distinct, rust-colored band in the gel at the oxic-anoxic interface. The cells were tightly associated with the ferric hydroxides. Repeated serial dilutions of both enrichments resulted in the isolation of two axenic strains, ES-1 and ES-2. The cultures were judged pure based on (i) growth from single colonies in tubes at dilutions of 10(-7) (ES-2) (ES-2) and 10(-8) (ES-1); (ii) uniform cell morphologies, i.e., ES-1 was a motile long thin, bent, or S-shaped rod and ES-2 was a shorter curved rod; and (iii) no growth on a heterotrophic medium. Strain ES-1 grew to a density of 10(8) cells/ml on FeS with a doubling time of 8 h. Strain ES-2 grew to a density of 5 x 10(7) cells/ml with a doubling time of 12.5 h. Both strains also grew on FeCO3. Neither strain grew without Fe2+, nor did they grow with glucose, pyruvate, acetate, Mn, or H2S as an electron donor. Studies with an oxygen microelectrode revealed that both strains grew at the oxic-anoxic interface of the gradients and tracked the O2 minima when subjected to higher O2 concentrations, suggesting they are microaerobes. Phylogenetically the two strains formed a novel lineage within the gamma Proteobacteria. They were very closely related to each other and were equally closely related to PVB OTU 1, a phylotype obtained from an iron-rich hydrothermal vent system at the Loihi Seamount in the Pacific Ocean, and SPB OTU 1, a phylotype obtained from permafrost soil in Siberia. Their closest cultivated relative was Stenotrophomonas maltophilia. In total, this evidence suggests ES-1 and ES-2 are members of a previously untapped group of putatively lithotrophic, unicellular iron-oxidizing bacteria. PMID:9406396

  5. Isotopologue signatures of nitrous oxide produced by nitrate-ammonifying bacteria isolated from soil

    NASA Astrophysics Data System (ADS)

    Behrendt, Undine; Well, Reinhard; Giesemann, Anette; Ulrich, Andreas; Augustin, Jürgen

    2015-04-01

    Agricultural soils are the largest single source of anthropogenic N2O to the atmosphere, primarily driven by microbiological processes such as denitrification and dissimilatory nitrate reduction to ammonium (DNRA). Both processes occur under similar conditions of low oxygen concentration and therefore, source partitioning of emitted N2O is difficult. Understanding what controls the dynamics and reaction equilibrium of denitrification and DNRA is important and may allow the development of more effective mitigation strategies. 15N site preference (SP), i.e. the difference between 15N of the central and peripheral N-position of the asymmetric N2O molecule, differs depending on processes involved in N2O formation. Hence investigation of the isotopomer ratios of formed N2O potentially presents a reliable mean to identify its source. In this study, bacterial isolates obtained from organic soils were screened for their ability to reduce nitrate/nitrite to ammonium and to release N2O to the atmosphere. Taxonomic characterisation of the strains revealed that N2O formation was only detected in ammonifying strains affiliated to several genera of the family Enterobacteriaceae and strains belonging to the genus Bacillus and Paenibacillus. Sampling of N2O was conducted by incubation of strains under oxic and anoxic conditions. Investigation of the 15N site preference showed SP values in the range of 39 to 57 o . Incubation conditions had no influence on the SP. The lowest values were achieved by a strain of the species Escherichia coli which was included in this study as a DNRA reference bacterium harbouring the NrfA gene that is coding the nitrite reductase, associated with respiratory nitrite ammonification. Soil isolates showed SP-values higher than 40 o . Comparison of these results with SP-values of N2O produced by denitrifying bacteria in pure cultures (-5 to 0 o )^[1, 2]revealedsignificantdifferences.Incontrast,N_2OproducedbydenitrifyingfungidisplayedSP - valuesinarangeof

  6. PHB-degrading bacteria isolated from the gastrointestinal tract of aquatic animals as protective actors against luminescent vibriosis.

    PubMed

    Liu, Yiying; De Schryver, Peter; Van Delsen, Bart; Maignien, Loïs; Boon, Nico; Sorgeloos, Patrick; Verstraete, Willy; Bossier, Peter; Defoirdt, Tom

    2010-10-01

    The use of poly-β-hydroxybutyrate (PHB) was shown to be successful in increasing the resistance of brine shrimp against pathogenic infections. In this study, we isolated for the first time PHB-degrading bacteria from a gastrointestinal environment. Pure strains of PHB-degrading bacteria were isolated from Siberian sturgeon, European sea bass and giant river prawn. The capability of selected isolates to degrade PHB was confirmed in at least two of three setups: (1) growth in minimal medium containing PHB as the sole carbon (C) source, (2) production of clearing zones on minimal agar containing PHB as the sole C source and (3) degradation of PHB (as determined by HPLC analysis) in 10% Luria-Bertani medium containing PHB. Challenge tests showed that the PHB-degrading activity of the selected isolates increased the survival of brine shrimp larvae challenged to a pathogenic Vibrio campbellii strain by a factor 2-3. Finally, one of the PHB-degrading isolates from sturgeon showed a double biocontrol effect because it was also able to inactivate acylhomoserine lactones, a type of quorum-sensing molecule that regulates the virulence of different pathogenic bacteria. Thus, the combined supplementation of a PHB-degrading bacterium and PHB as a synbioticum provides perspectives for improving the gastrointestinal health of aquatic animals. PMID:20597982

  7. Use of an insect cell culture growth medium to isolate bacteria from horses with effusive, fibrinous pericarditis: a preliminary study.

    PubMed

    Jones, Samuel L; Valenzisi, Amy; Sontakke, Sushama; Sprayberry, Kimberly A; Maggi, Ricardo; Hegarty, Barbara; Breitschwerdt, Edward

    2007-03-31

    Effusive, fibrinous pericarditis is an uncommon disease entity in horses. In 2001, pericarditis occurred in conjunction with an epizootic in central Kentucky that was associated with exposure to eastern tent caterpillars (ETCs). Bacterial isolation from equine pericardial fluid samples was attempted using an insect cell culture growth medium (ICCGM). Using previously cultured, stored frozen samples from four horses with fibrinous pericarditis, inoculation of 10% blood agar plates yielded no growth, whereas simultaneous inoculation of ICCGM resulted in the isolation of Proprionibacterium acnes, Staphylococcus equorum, a Streptococcus sp. and Pseudomonas rhodesiae from pericardial fluid samples. A similar or novel caterpillar-associated bacteria was not identified; however, use of an ICCGM might enhance isolation of bacteria from equine pericardial fluid.

  8. Diversity of lactic acid bacteria isolated from Brazilian water buffalo mozzarella cheese.

    PubMed

    Silva, Luana Faria; Casella, Tiago; Gomes, Elisangela Soares; Nogueira, Mara Correa Lelles; De Dea Lindner, Juliano; Penna, Ana Lúcia Barretto

    2015-02-01

    The water buffalo mozzarella cheese is a typical Italian cheese which has been introduced in the thriving Brazilian market in the last 10 y, with good acceptance by its consumers. Lactic acid bacteria (LAB) play an important role in the technological and sensory quality of mozzarella cheese. In this study, the aim was to evaluate the diversity of the autochthones viable LAB isolated from water buffalo mozzarella cheese under storage. Samples were collected in 3 independent trials in a dairy industry located in the southeast region of Brazil, on the 28th day of storage, at 4 ºC. The LAB were characterized by Gram staining, catalase test, capacity to assimilate citrate, and production of CO2 from glucose. The diversity of LAB was evaluated by RAPD-PCR (randomly amplified polymorphic DNA-polymerase chain reaction), 16S rRNA gene sequencing, and by Vitek 2 system. Twenty LAB strains were isolated and clustered into 12 different clusters, and identified as Streptococcus thermophilus, Enterococcus faecium, Enterococcus durans, Leuconostoc mesenteroides subsp. mesenteroides, Lactobacillus fermentum, Lactobacillus casei, Lactobacillus delbrueckii subsp. bulgaricus, and Lactobacillus helveticus. Enterococcus species were dominant and citrate-positive. Only the strains of L. mesenteroides subsp. mesenteroides and L. fermentum produced CO2 from glucose and were citrate-positive, while L. casei was only citrate positive. This is the first report which elucidates the LAB diversity involved in Brazilian water buffalo mozzarella cheese. Furthermore, the results show that despite the absence of natural whey cultures as starters in production, the LAB species identified are the ones typically found in mozzarella cheese.

  9. Identification and Antimicrobial Activity Detection of Lactic Acid Bacteria Isolated from Corn Stover Silage

    PubMed Central

    Li, Dongxia; Ni, Kuikui; Pang, Huili; Wang, Yanping; Cai, Yimin; Jin, Qingsheng

    2015-01-01

    A total of 59 lactic acid bacteria (LAB) strains were isolated from corn stover silage. According to phenotypic and chemotaxonomic characteristics, 16S ribosomal DNA (rDNA) sequences and recA gene polymerase chain reaction amplification, these LAB isolates were identified as five species: Lactobacillus (L.) plantarum subsp. plantarum, Pediococcus pentosaceus, Enterococcus mundtii, Weissella cibaria and Leuconostoc pseudomesenteroides, respectively. Those strains were also screened for antimicrobial activity using a dual-culture agar plate assay. Based on excluding the effects of organic acids and hydrogen peroxide, two L. plantarum subsp. plantarum strains ZZU 203 and 204, which strongly inhibited Salmonella enterica ATCC 43971T, Micrococcus luteus ATCC 4698T and Escherichia coli ATCC 11775T were selected for further research on sensitivity of the antimicrobial substance to heat, pH and protease. Cell-free culture supernatants of the two strains exhibited strong heat stability (60 min at 100°C), but the antimicrobial activity was eliminated after treatment at 121°C for 15 min. The antimicrobial substance remained active under acidic condition (pH 2.0 to 6.0), but became inactive under neutral and alkaline condition (pH 7.0 to 9.0). In addition, the antimicrobial activities of these two strains decreased remarkably after digestion by protease K. These results preliminarily suggest that the desirable antimicrobial activity of strains ZZU 203 and 204 is the result of the production of a bacteriocin-like substance, and these two strains with antimicrobial activity could be used as silage additives to inhibit proliferation of unwanted microorganism during ensiling and preserve nutrients of silage. The nature of the antimicrobial substances is being investigated in our laboratory. PMID:25924957

  10. Identification and antimicrobial activity detection of lactic Acid bacteria isolated from corn stover silage.

    PubMed

    Li, Dongxia; Ni, Kuikui; Pang, Huili; Wang, Yanping; Cai, Yimin; Jin, Qingsheng

    2015-05-01

    A total of 59 lactic acid bacteria (LAB) strains were isolated from corn stover silage. According to phenotypic and chemotaxonomic characteristics, 16S ribosomal DNA (rDNA) sequences and recA gene polymerase chain reaction amplification, these LAB isolates were identified as five species: Lactobacillus (L.) plantarum subsp. plantarum, Pediococcus pentosaceus, Enterococcus mundtii, Weissella cibaria and Leuconostoc pseudomesenteroides, respectively. Those strains were also screened for antimicrobial activity using a dual-culture agar plate assay. Based on excluding the effects of organic acids and hydrogen peroxide, two L. plantarum subsp. plantarum strains ZZU 203 and 204, which strongly inhibited Salmonella enterica ATCC 43971(T), Micrococcus luteus ATCC 4698(T) and Escherichia coli ATCC 11775(T) were selected for further research on sensitivity of the antimicrobial substance to heat, pH and protease. Cell-free culture supernatants of the two strains exhibited strong heat stability (60 min at 100°C), but the antimicrobial activity was eliminated after treatment at 121°C for 15 min. The antimicrobial substance remained active under acidic condition (pH 2.0 to 6.0), but became inactive under neutral and alkaline condition (pH 7.0 to 9.0). In addition, the antimicrobial activities of these two strains decreased remarkably after digestion by protease K. These results preliminarily suggest that the desirable antimicrobial activity of strains ZZU 203 and 204 is the result of the production of a bacteriocin-like substance, and these two strains with antimicrobial activity could be used as silage additives to inhibit proliferation of unwanted microorganism during ensiling and preserve nutrients of silage. The nature of the antimicrobial substances is being investigated in our laboratory.

  11. Magnetic nanoparticle-mediated isolation of functional bacteria in a complex microbial community.

    PubMed

    Zhang, Dayi; Berry, James P; Zhu, Di; Wang, Yun; Chen, Yin; Jiang, Bo; Huang, Shi; Langford, Harry; Li, Guanghe; Davison, Paul A; Xu, Jian; Aries, Eric; Huang, Wei E

    2015-03-01

    Although uncultured microorganisms have important roles in ecosystems, their ecophysiology in situ remains elusive owing to the difficulty of obtaining live cells from their natural habitats. In this study, we employed a novel magnetic nanoparticle-mediated isolation (MMI) method to recover metabolically active cells of a group of previously uncultured phenol degraders, Burkholderiales spp., from coking plant wastewater biosludge; five other culturable phenol degraders-Rhodococcus sp., Chryseobacterium sp. and three different Pseudomonas spp.-were also isolated from the same biosludge using traditional methods. The kinetics of phenol degradation by MMI-recovered cells (MRCs) was similar to that of the original sludge. Stable isotope probing (SIP) and pyrosequencing of the 16S rRNA from the 'heavy' DNA ((13)C-DNA) fractions indicated that Burkholderiales spp. were the key phenol degraders in situ in the biosludge, consistent with the results of MRCs. Single-cell Raman micro-spectroscopy was applied to probe individual bacteria in the MRCs obtained from the SIP experiment and showed that 79% of them were fully (13)C-labelled. Biolog assays on the MRCs revealed the impact of various carbon and nitrogen substrates on the efficiency of phenol degradation in the wastewater treatment plant biosludge. Specifically, hydroxylamine, a metabolite of ammonia oxidisation, but not nitrite, nitrate or ammonia, inhibited phenol degradation in the biosludge. Our results provided a novel insight into the occasional abrupt failure events that occur in the wastewater treatment plant. This study demonstrated that MMI is a powerful tool to recover live and functional cells in situ from a complex microbial community to enable further characterisation of their physiology.

  12. Magnetic nanoparticle-mediated isolation of functional bacteria in a complex microbial community

    PubMed Central

    Zhang, Dayi; Berry, James P; Zhu, Di; Wang, Yun; Chen, Yin; Jiang, Bo; Huang, Shi; Langford, Harry; Li, Guanghe; Davison, Paul A; Xu, Jian; Aries, Eric; Huang, Wei E

    2015-01-01

    Although uncultured microorganisms have important roles in ecosystems, their ecophysiology in situ remains elusive owing to the difficulty of obtaining live cells from their natural habitats. In this study, we employed a novel magnetic nanoparticle-mediated isolation (MMI) method to recover metabolically active cells of a group of previously uncultured phenol degraders, Burkholderiales spp., from coking plant wastewater biosludge; five other culturable phenol degraders—Rhodococcus sp., Chryseobacterium sp. and three different Pseudomonas spp.—were also isolated from the same biosludge using traditional methods. The kinetics of phenol degradation by MMI-recovered cells (MRCs) was similar to that of the original sludge. Stable isotope probing (SIP) and pyrosequencing of the 16S rRNA from the ‘heavy' DNA (13C-DNA) fractions indicated that Burkholderiales spp. were the key phenol degraders in situ in the biosludge, consistent with the results of MRCs. Single-cell Raman micro-spectroscopy was applied to probe individual bacteria in the MRCs obtained from the SIP experiment and showed that 79% of them were fully 13C-labelled. Biolog assays on the MRCs revealed the impact of various carbon and nitrogen substrates on the efficiency of phenol degradation in the wastewater treatment plant biosludge. Specifically, hydroxylamine, a metabolite of ammonia oxidisation, but not nitrite, nitrate or ammonia, inhibited phenol degradation in the biosludge. Our results provided a novel insight into the occasional abrupt failure events that occur in the wastewater treatment plant. This study demonstrated that MMI is a powerful tool to recover live and functional cells in situ from a complex microbial community to enable further characterisation of their physiology. PMID:25191996

  13. Isolation and characterization of bacteriocin-producing lactic acid bacteria from ready-to-eat food products.

    PubMed

    Kelly, W J; Asmundson, R V; Huang, C M

    1996-12-01

    Lactic acid bacteria isolated from a range of foods sold in ready-to-eat form were screened for bacteriocin production. Twenty-two bacteriocin-producing cultures were isolated from 14 of the 41 foods sampled. Bacteriocin-producing isolates from meat, fish and dairy products were Lactobacillus and Leuconostoc species typically found associated with these products. Most of these isolates gave only a narrow inhibitory spectrum although two showed activity against Listeria monocytogenes. Fruit and vegetable products gave a broader range of organisms but most of the bacteriocin-producing cultures were found to be strains of Lactococcus. Several lactococci produced a nisin-like activity, and showed a broad inhibitory spectrum against the indicator strains tested. The ease with which bacteriocin-producing strains could be isolated implies that they are already being safely consumed in food, and highlights the potential for using bacteriocin-producing cultures for biopreservation, especially in association with minimally processed products. PMID:8930706

  14. Taxonomic and symbiotic diversity of bacteria isolated from nodules of Acacia tortilis subsp. raddiana in arid soils of Tunisia.

    PubMed

    Fterich, A; Mahdhi, M; Lafuente, A; Pajuelo, E; Caviedes, M A; Rodriguez-Llorente, I D; Mars, M

    2012-06-01

    A collection of rhizobia isolated from Acacia tortilis subsp. raddiana nodules from various arid soils in Tunisia was analyzed for their diversity at both taxonomic and symbiotic levels. The isolates were found to be phenotypically diverse. The majority of the isolates tolerated 3% NaCl and grew at 40 °C. Genetic characterization emphasized that most of the strains (42/50) belong to the genus Ensifer, particularly the species Ensifer meliloti, Ensifer garamanticus, and Ensifer numidicus. Symbiotic properties of isolates showed diversity in their capacity to nodulate their host plant and to fix atmospheric nitrogen. The most effective isolates were closely related to E. garamanticus. Nodulation tests showed that 3 strains belonging to Mesorhizobium genus failed to renodulate their host plant, which is surprising for symbiotic rhizobia. Furthermore, our results support the presence of non-nodulating endophytic bacteria belonging to the Acinetobacter genus in legume nodules. PMID:22616625

  15. Isolation and Characterization of Polycyclic Aromatic Hydrocarbon-Degrading Bacteria Associated with the Rhizosphere of Salt Marsh Plants

    PubMed Central

    Daane, L. L.; Harjono, I.; Zylstra, G. J.; Häggblom, M. M.

    2001-01-01

    Polycyclic aromatic hydrocarbon (PAH)-degrading bacteria were isolated from contaminated estuarine sediment and salt marsh rhizosphere by enrichment using either naphthalene, phenanthrene, or biphenyl as the sole source of carbon and energy. Pasteurization of samples prior to enrichment resulted in isolation of gram-positive, spore-forming bacteria. The isolates were characterized using a variety of phenotypic, morphologic, and molecular properties. Identification of the isolates based on their fatty acid profiles and partial 16S rRNA gene sequences assigned them to three main bacterial groups: gram-negative pseudomonads; gram-positive, non-spore-forming nocardioforms; and the gram-positive, spore-forming group, Paenibacillus. Genomic digest patterns of all isolates were used to determine unique isolates, and representatives from each bacterial group were chosen for further investigation. Southern hybridization was performed using genes for PAH degradation from Pseudomonas putida NCIB 9816-4, Comamonas testosteroni GZ42, Sphingomonas yanoikuyae B1, and Mycobacterium sp. strain PY01. None of the isolates from the three groups showed homology to the B1 genes, only two nocardioform isolates showed homology to the PY01 genes, and only members of the pseudomonad group showed homology to the NCIB 9816-4 or GZ42 probes. The Paenibacillus isolates showed no homology to any of the tested gene probes, indicating the possibility of novel genes for PAH degradation. Pure culture substrate utilization experiments using several selected isolates from each of the three groups showed that the phenanthrene-enriched isolates are able to utilize a greater number of PAHs than are the naphthalene-enriched isolates. Inoculating two of the gram-positive isolates to a marine sediment slurry spiked with a mixture of PAHs (naphthalene, fluorene, phenanthrene, and pyrene) and biphenyl resulted in rapid transformation of pyrene, in addition to the two- and three-ringed PAHs and biphenyl. This

  16. Isolation of antibiotic-resistant pathogenic and potentially pathogenic bacteria from carpets of mosques in Tripoli, Libya

    PubMed Central

    Rahouma, Amal; Elghamoudi, Abdunabi; Nashnoush, Halima; Belhaj, Khalifa; Tawil, Khaled; Sifaw Ghenghesh, Khalifa

    2010-01-01

    Objective Isolation of potentially pathogenic bacteria from carpets in hospitals has been reported earlier, but not from carpets in mosques. The aim of the present study is to determine the pathogenic and potentially pathogenic bacteria that may exist on the carpets of mosques in Tripoli, Libya. Methods Dust samples from carpets were collected from 57 mosques in Tripoli. Samples were examined for pathogenic bacteria using standard bacteriological procedures. Susceptibility of isolated bacteria to antimicrobial agents was determined by the disc-diffusion method. Results Of dust samples examined, Salmonella spp. was detected in two samples (3.5%, 1 in group B and 1 in group C1), Escherichia coli in 16 samples (28.1%), Aeromonas spp. in one sample (1.8%), and Staphylococcus aureus in 12 samples (21.1%). Multiple drug resistance was observed in >16.7% of E. coli and in 25% of S. aureus. Conclusion Contamination of carpets in mosques of Tripoli with antibiotic-resistant pathogenic and potentially pathogenic bacteria may pose a health risk to worshipers, particularly, the very young, the old and the immunecompromised. Worshipers are encouraged to use personal praying mats when praying in mosques. PMID:21483559

  17. Isolation of an antimicrobial compound produced by bacteria associated with reef-building corals

    PubMed Central

    Tapiolas, Dianne; Motti, Cherie A.; Foret, Sylvain; Tebben, Jan; Willis, Bette L.; Bourne, David G.

    2016-01-01

    Bacterial communities associated with healthy corals produce antimicrobial compounds that inhibit the colonization and growth of invasive microbes and potential pathogens. To date, however, bacteria-derived antimicrobial molecules have not been identified in reef-building corals. Here, we report the isolation of an antimicrobial compound produced by Pseudovibrio sp. P12, a common and abundant coral-associated bacterium. This strain was capable of metabolizing dimethylsulfoniopropionate (DMSP), a sulfur molecule produced in high concentrations by reef-building corals and playing a role in structuring their bacterial communities. Bioassay-guided fractionation coupled with nuclear magnetic resonance (NMR) and mass spectrometry (MS), identified the antimicrobial as tropodithietic acid (TDA), a sulfur-containing compound likely derived from DMSP catabolism. TDA was produced in large quantities by Pseudovibrio sp., and prevented the growth of two previously identified coral pathogens, Vibrio coralliilyticus and V. owensii, at very low concentrations (0.5 μg/mL) in agar diffusion assays. Genome sequencing of Pseudovibrio sp. P12 identified gene homologs likely involved in the metabolism of DMSP and production of TDA. These results provide additional evidence for the integral role of DMSP in structuring coral-associated bacterial communities and underline the potential of these DMSP-metabolizing microbes to contribute to coral disease prevention.

  18. Tetracycline modifies competitive interactions in experimental microcosms containing bacteria isolated from freshwater.

    PubMed

    Hall, Alex R; Corno, Gianluca

    2014-10-01

    Interspecific microbial interactions are important for community structure, function and evolution, but it is not fully understood how interactions among bacterial species are influenced by some types of abiotic environmental variation, such as exposure to antibiotics. We tested for the effect of an antibiotic, tetracycline, on interspecific interactions in vitro among four species of aquatic bacteria isolated from European water bodies. Interactions among species in experimental microcosms containing artificial lake water (ALW) supplemented with glucose were largely competitive, as detected by comparing mixed cultures to pure cultures of their constituent species. Sublethal concentrations of tetracycline changed the relative competitive abilities of different species and revealed considerable variation in antibiotic sensitivity, but did not reduce the average strength of competition. Interspecific interactions at a given concentration were largely predictable from growth in pure cultures and indirect interactions with other species. These results suggest that antibiotics such as tetracycline may have important consequences for interactions among bacterial species, but in our experiments this was because species varied in their capacities for growth in the presence of tetracycline, rather than reduced competition at increasing tetracycline concentrations. PMID:25056916

  19. Isolation of an antimicrobial compound produced by bacteria associated with reef-building corals

    PubMed Central

    Tapiolas, Dianne; Motti, Cherie A.; Foret, Sylvain; Tebben, Jan; Willis, Bette L.; Bourne, David G.

    2016-01-01

    Bacterial communities associated with healthy corals produce antimicrobial compounds that inhibit the colonization and growth of invasive microbes and potential pathogens. To date, however, bacteria-derived antimicrobial molecules have not been identified in reef-building corals. Here, we report the isolation of an antimicrobial compound produced by Pseudovibrio sp. P12, a common and abundant coral-associated bacterium. This strain was capable of metabolizing dimethylsulfoniopropionate (DMSP), a sulfur molecule produced in high concentrations by reef-building corals and playing a role in structuring their bacterial communities. Bioassay-guided fractionation coupled with nuclear magnetic resonance (NMR) and mass spectrometry (MS), identified the antimicrobial as tropodithietic acid (TDA), a sulfur-containing compound likely derived from DMSP catabolism. TDA was produced in large quantities by Pseudovibrio sp., and prevented the growth of two previously identified coral pathogens, Vibrio coralliilyticus and V. owensii, at very low concentrations (0.5 μg/mL) in agar diffusion assays. Genome sequencing of Pseudovibrio sp. P12 identified gene homologs likely involved in the metabolism of DMSP and production of TDA. These results provide additional evidence for the integral role of DMSP in structuring coral-associated bacterial communities and underline the potential of these DMSP-metabolizing microbes to contribute to coral disease prevention. PMID:27602265

  20. Isolation and Characterization of Methanesulfonic Acid-Degrading Bacteria from the Marine Environment

    PubMed Central

    Thompson, A. S.; Owens, N.; Murrell, J. C.

    1995-01-01

    Two methylotrophic bacterial strains, TR3 and PSCH4, capable of growth on methanesulfonic acid as the sole carbon source were isolated from the marine environment. Methanesulfonic acid metabolism in these strains was initiated by an inducible NADH-dependent monooxygenase, which cleaved methanesulfonic acid into formaldehyde and sulfite. The presence of hydroxypyruvate reductase and the absence of ribulose monophosphate-dependent hexulose monophosphate synthase indicated the presence of the serine pathway for formaldehyde assimilation. Cell suspensions of bacteria grown on methanesulfonic acid completely oxidized methanesulfonic acid to carbon dioxide and sulfite with a methanesulfonic acid/oxygen stoichiometry of 1.0:2.0. Oxygen electrode-substrate studies indicated the dissimilation of formaldehyde to formate and carbon dioxide for energy generation. Carbon dioxide was not fixed by ribulose bisphosphate carboxylase. It was shown that methanol is not an intermediate in methanesulfonic acid metabolism, although these strains grew on methanol and other one-carbon compounds, as well as a variety of heterotrophic carbon sources. These two novel marine facultative methylotrophs have the ability to mineralize methanesulfonic acid and may play a role in the cycling of global organic sulfur. PMID:16535055

  1. CIPROFLOXACIN RESISTANCE PATTERN AMONG BACTERIA ISOLATED FROM PATIENTS WITH COMMUNITY-ACQUIRED URINARY TRACT INFECTION

    PubMed Central

    REIS, Ana Carolina Costa; SANTOS, Susana Regia da Silva; de SOUZA, Siane Campos; SALDANHA, Milena Góes; PITANGA, Thassila Nogueira; OLIVEIRA, Ricardo Riccio

    2016-01-01

    SUMMARY Objective: To identify the main bacterial species associated with community-acquired urinary tract infection (UTI) and to assess the pattern of ciprofloxacin susceptibility among bacteria isolated from urine cultures. Methods: We conducted a retrospective study in all the patients with community-acquired UTI seen in Santa Helena Laboratory, Camaçari, Bahia, Brazil during five years (2010-2014). All individuals who had a positive urine culture result were included in this study. Results: A total of 1,641 individuals met the inclusion criteria. Despite the fact that participants were female, we observed a higher rate of resistance to ciprofloxacin in males. The most frequent pathogens identified in urine samples were Escherichia coli, Klebsiella pneumoniae and Staphylococcus saprophyticus. Antimicrobial resistance has been observed mainly for ampicillin, sulfamethoxazole + trimethoprim and ciprofloxacin. Moreover, E. coli has shown the highest rate of ciprofloxacin resistance, reaching 36% of ciprofloxacin resistant strains in 2014. Conclusion: The rate of bacterial resistance to ciprofloxacin observed in the studied population is much higher than expected, prompting the need for rational use of this antibiotic, especially in infections caused by E. coli. Prevention of bacterial resistance can be performed through control measures to limit the spread of resistant microorganisms and a rational use of antimicrobial policy. PMID:27410913

  2. Isolation of bacteria with antifungal activity against the phytopathogenic fungi Stenocarpella maydis and Stenocarpella macrospora.

    PubMed

    Petatán-Sagahón, Iván; Anducho-Reyes, Miguel Angel; Silva-Rojas, Hilda Victoria; Arana-Cuenca, Ainhoa; Tellez-Jurado, Alejandro; Cárdenas-Álvarez, Isabel Oyuki; Mercado-Flores, Yuridia

    2011-01-01

    Stenocarpella maydis and Stenocarpella macrospora are the causal agents of ear rot in corn, which is one of the most destructive diseases in this crop worldwide. These fungi are important mycotoxin producers that cause different pathologies in farmed animals and represent an important risk for humans. In this work, 160 strains were isolated from soil of corn crops of which 10 showed antifungal activity against these phytopathogens, which, were identified as: Bacillus subtilis, Pseudomonas spp., Pseudomonas fluorescens, and Pantoea agglomerans by sequencing of 16S rRNA gene and the phylogenetic analysis. From cultures of each strain, extracellular filtrates were obtained and assayed to determine antifungal activity. The best filtrates were obtained in the stationary phase of B. subtilis cultures that were stable to the temperature and extreme pH values; in addition they did not show a cytotoxicity effect against brine shrimp and inhibited germination of conidia. The bacteria described in this work have the potential to be used in the control of white ear rot disease. PMID:22016606

  3. Isolation of an antimicrobial compound produced by bacteria associated with reef-building corals.

    PubMed

    Raina, Jean-Baptiste; Tapiolas, Dianne; Motti, Cherie A; Foret, Sylvain; Seemann, Torsten; Tebben, Jan; Willis, Bette L; Bourne, David G

    2016-01-01

    Bacterial communities associated with healthy corals produce antimicrobial compounds that inhibit the colonization and growth of invasive microbes and potential pathogens. To date, however, bacteria-derived antimicrobial molecules have not been identified in reef-building corals. Here, we report the isolation of an antimicrobial compound produced by Pseudovibrio sp. P12, a common and abundant coral-associated bacterium. This strain was capable of metabolizing dimethylsulfoniopropionate (DMSP), a sulfur molecule produced in high concentrations by reef-building corals and playing a role in structuring their bacterial communities. Bioassay-guided fractionation coupled with nuclear magnetic resonance (NMR) and mass spectrometry (MS), identified the antimicrobial as tropodithietic acid (TDA), a sulfur-containing compound likely derived from DMSP catabolism. TDA was produced in large quantities by Pseudovibrio sp., and prevented the growth of two previously identified coral pathogens, Vibrio coralliilyticus and V. owensii, at very low concentrations (0.5 μg/mL) in agar diffusion assays. Genome sequencing of Pseudovibrio sp. P12 identified gene homologs likely involved in the metabolism of DMSP and production of TDA. These results provide additional evidence for the integral role of DMSP in structuring coral-associated bacterial communities and underline the potential of these DMSP-metabolizing microbes to contribute to coral disease prevention. PMID:27602265

  4. Biofilm-Forming Capacity in Biogenic Amine-Producing Bacteria Isolated from Dairy Products.

    PubMed

    Diaz, Maria; Ladero, Victor; Del Rio, Beatriz; Redruello, Begoña; Fernández, María; Martin, M Cruz; Alvarez, Miguel A

    2016-01-01

    Biofilms on the surface of food industry equipment are reservoirs of potentially food-contaminating bacteria-both spoilage and pathogenic. However, the capacity of biogenic amine (BA)-producers to form biofilms has remained largely unexamined. BAs are low molecular weight, biologically active compounds that in food can reach concentrations high enough to be a toxicological hazard. Fermented foods, especially some types of cheese, accumulate the highest BA concentrations of all. The present work examines the biofilm-forming capacity of 56 BA-producing strains belonging to three genera and 10 species (12 Enterococcus faecalis, 6 Enterococcus faecium, 6 Enterococcus durans, 1 Enterococcus hirae, 12 Lactococcus lactis, 7 Lactobacillus vaginalis, 2 Lactobacillus curvatus, 2 Lactobacillus brevis, 1 Lactobacillus reuteri, and 7 Lactobacillus parabuchneri), all isolated from dairy products. Strains of all the tested species - except for L. vaginalis-were able to produce biofilms on polystyrene and adhered to stainless steel. However, the biomass produced in biofilms was strain-dependent. These results suggest that biofilms may provide a route via which fermented foods can become contaminated by BA-producing microorganisms. PMID:27242675

  5. Isolation and molecular detection of methylotrophic bacteria occurring in the human mouth.

    PubMed

    Anesti, Vasiliki; McDonald, Ian R; Ramaswamy, Meghna; Wade, William G; Kelly, Donovan P; Wood, Ann P

    2005-08-01

    Diverse methylotrophic bacteria were isolated from the tongue, and supra- and subgingival plaque in the mouths of volunteers and patients with periodontitis. One-carbon compounds such as dimethylsulfide in the mouth are likely to be used as growth substrates for these organisms. Methylotrophic strains of Bacillus, Brevibacterium casei, Hyphomicrobium sulfonivorans, Methylobacterium, Micrococcus luteus and Variovorax paradoxus were characterized physiologically and by their 16S rRNA gene sequences. The type strain of B. casei was shown to be methylotrophic. Enzymes of methylotrophic metabolism were characterized in some strains, and activities consistent with growth using known pathways of C1-compound metabolism demonstrated. Genomic DNA from 18 tongue and dental plaque samples from nine volunteers was amplified by the polymerase chain reaction using primers for the 16S rRNA gene of Methylobacterium and the mxaF gene of methanol dehydrogenase. MxaF was detected in all nine volunteers, and Methylobacterium was detected in seven. Methylotrophic activity is thus a feature of the oral bacterial community. PMID:16011760

  6. Diverse bacteria isolated from root nodules of wild Vicia species grown in temperate region of China.

    PubMed

    Lei, Xia; Wang, En Tao; Chen, Wen Feng; Sui, Xin Hua; Chen, Wen Xin

    2008-12-01

    In the present study, a total of 154 bacterial strains isolated from nodules of eighteen Vicia species mainly grown in the temperate Chinese provinces were characterized by ARDRA, ITS PCR-RFLP, BOX-PCR, sequencing of 16S rDNA, nodC, nifH, atpD and glnII, and nodulation tests. The results demonstrated that most of the R. leguminosarum strains were effective microsymbionts of the wild Vicia species, while genomic species related to Rhizobium gallicum, Mesorhizobium huakuii, Ensifer meliloti and Bradyrhizobium spp. were symbiotic bacteria occasionally nodulating with Vicia species. In addition, fourteen strains related to Agrobacterium, Phyllobacterium, Ensifer, Shinella and R. tropici, as well as 22 strains of R. leguminosarum might be nodule endophytes without symbiotic genes. Diverse symbiotic gene lineages were found among the test strains and a strong association was found among the symbiotic gene types and genomic species, indicating the absence of lateral gene transfer. These results greatly enlarged the rhizobial spectrum of Vicia species.

  7. Isolation and characterization of the native entomopathogenic nematode, Heterorhabditis brevicaudis, and its symbiotic bacteria from Taiwan.

    PubMed

    Hsieh, Feng-Chia; Tzeng, Chiaw-Yen; Tseng, Jui-Tang; Tsai, Yeong-Sheng; Meng, Menghsiao; Kao, Suey-Sheng

    2009-06-01

    The occurrence of Heterorhabditis brevicaudis (Rhabditida: Heterorhabditidae) and its symbiotic bacteria, Photorhabdus luminescens subsp. akhurstii in Taiwan were recorded for the first time. H. brevicaudis was described by Liu in 1994, but it was unavailable and no molecular data has ever been published for it ever since. The native entomopathogenic nematode (EPN), H. brevicaudis TG01 was recovered from sandy coastal soils in moist bamboo forest, as observed in this article. The bacterial symbiont was isolated from H. brevicaudis for the first time. On the basis of biochemical tests and 16S rDNA it was identified as P. luminescens subsp. akhurstii. This is also the first report of novel nucleotide sequences of the internal transcribed spacer (ITS) from H. brevicaudis. The phylogenetic relationships of ITS sequences were established using Neighbor-Joining, Maximum Parsimony, and Maximum Likelihood methods. The inferred trees strongly support that H. brevicaudis TG01 is specifically related to H. indica and H. hawaiiensis. But the tail length of the infective juveniles (IJ) of H. brevicaudis TG01 in our study, which was less than 80 microm, shorter than that of other species indeed, fall within the original description for H. brevicaudis. Moreover, comparing with morphometrics of IJ and male of H. brevicaudis and H. indica, we recognize that the H. brevicaudis TG01 does not represent variation among populations of H. indica and H. hawaiiensis. This article will answer questions regarding the status of H. brevicaudis and would also provide this species for further investigation. PMID:19214629

  8. Biodegradation of geosmin in drinking water by novel bacteria isolated from biologically active carbon.

    PubMed

    Zhou, Beihai; Yuan, Rongfang; Shi, Chunhong; Yu, Liying; Gu, Junnong; Zhang, Chunlei

    2011-01-01

    Three strains of Gram-negative bacteria capable of removing geosmin from drinking water were isolated from biologically active carbon and identified to be Chryseobacterium sp., Sinorhizobium sp. and Stenotrophomonas sp. based on physio-biochemistry analysis and 16S rRNA gene sequence analysis. Removal efficiencies of 2 mg/L geosmin in mineral salts medium were 84.0%, 80.2% and 74.4% for Chryseobacterium sp., Sinorhizobium sp. and Stenotrophomonas sp., respectively, while removal efficiencies of 560 ng/L geosmin in filter influent were 84.8%, 82.3% and 82.5%, respectively. The biodegradation of geosmin was determined to be a pseudo first-order reaction, with rate constants at 2 mg/L and 560 ng/L being 0.097 and 0.086 day(-1), 0.089 and 0.084 day(-1), 0.074 and 0.098 day(-1) for the above mentioned degraders, respectively. The biomass of culture in the presence of geosmin was much higher than that in the absence of geosmin.

  9. Effect of human isolated probiotic bacteria on preventing Campylobacter jejuni colonization of poultry.

    PubMed

    Cean, Ada; Stef, Lavinia; Simiz, Eliza; Julean, Calin; Dumitrescu, Gabi; Vasile, Aida; Pet, Elena; Drinceanu, Dan; Corcionivoschi, Nicolae

    2015-02-01

    This study was performed in order to determine whether human isolated probiotic bacteria can be effective in reducing Campylobacter jejuni infection of chicken intestinal cells, in vitro, and in decreasing its colonization abilities within the chicken gut. Our results show that the probiotic strains Lactobacillus paracasei J. R, L. rhamnosus 15b, L. lactis Y, and L. lactis FOa had a significant effect on C. jejuni invasion of chicken primary cells, with the strongest inhibitory effect detected when a combination of four was administered. In regard to the in vivo effect, using all four strains in one combination prevented mucus colonization in the duodenum and cecum. Moreover, the pathogen load in the lumen of these two compartments was significantly reduced. When probiotics were introduced during the early growth period, the presence of the pathogen in feces was increased (p>0.05), but when they were given during the last week of growth, there was no significant effect. In conclusion, our data indicate that these four new probiotic strains are able to cause modifications in the chicken intestinal mucosa and can reduce the ability of C. jejuni to invade, in vitro, and to colonize, in vivo. These probiotics are now proven to be effective even when introduced in broiler's feed 7 days before slaughter, which makes them cost-effective for the producers.

  10. Exopolysaccharides isolated from hydrothermal vent bacteria can modulate the complement system.

    PubMed

    Courtois, Anthony; Berthou, Christian; Guézennec, Jean; Boisset, Claire; Bordron, Anne

    2014-01-01

    The complement system is involved in the defence against bacterial infection, or in the elimination of tumour cells. However, disturbances in this system contributes to the pathogenesis of various inflammatory diseases. The efficiency of therapeutic anti-tumour antibodies is enhanced when the complement system is stimulated. In contrast, cancer cells are able to inhibit the complement system and thus proliferate. Some marine molecules are currently being developed as new drugs for use in humans. Among them, known exopolyssacharides (EPSs) generally originate from fungi, but few studies have been performed on bacterial EPSs and even fewer on EPSs extracted from deep-sea hydrothermal vent microbes. For use in humans, these high molecular weight EPSs must be depolymerised. Furthermore, the over-sulphation of EPSs can modify their biological activity. The aim of this study was to investigate the immunodulation of the complement system by either native or over-sulphated low molecular weight EPSs isolated from vent bacteria in order to find pro or anti-activators of complement.

  11. Biofilm-Forming Capacity in Biogenic Amine-Producing Bacteria Isolated from Dairy Products.

    PubMed

    Diaz, Maria; Ladero, Victor; Del Rio, Beatriz; Redruello, Begoña; Fernández, María; Martin, M Cruz; Alvarez, Miguel A

    2016-01-01

    Biofilms on the surface of food industry equipment are reservoirs of potentially food-contaminating bacteria-both spoilage and pathogenic. However, the capacity of biogenic amine (BA)-producers to form biofilms has remained largely unexamined. BAs are low molecular weight, biologically active compounds that in food can reach concentrations high enough to be a toxicological hazard. Fermented foods, especially some types of cheese, accumulate the highest BA concentrations of all. The present work examines the biofilm-forming capacity of 56 BA-producing strains belonging to three genera and 10 species (12 Enterococcus faecalis, 6 Enterococcus faecium, 6 Enterococcus durans, 1 Enterococcus hirae, 12 Lactococcus lactis, 7 Lactobacillus vaginalis, 2 Lactobacillus curvatus, 2 Lactobacillus brevis, 1 Lactobacillus reuteri, and 7 Lactobacillus parabuchneri), all isolated from dairy products. Strains of all the tested species - except for L. vaginalis-were able to produce biofilms on polystyrene and adhered to stainless steel. However, the biomass produced in biofilms was strain-dependent. These results suggest that biofilms may provide a route via which fermented foods can become contaminated by BA-producing microorganisms.

  12. Isolation of Bacteria with Antifungal Activity against the Phytopathogenic Fungi Stenocarpella maydis and Stenocarpella macrospora

    PubMed Central

    Petatán-Sagahón, Iván; Anducho-Reyes, Miguel Angel; Silva-Rojas, Hilda Victoria; Arana-Cuenca, Ainhoa; Tellez-Jurado, Alejandro; Cárdenas-Álvarez, Isabel Oyuki; Mercado-Flores, Yuridia

    2011-01-01

    Stenocarpella maydis and Stenocarpella macrospora are the causal agents of ear rot in corn, which is one of the most destructive diseases in this crop worldwide. These fungi are important mycotoxin producers that cause different pathologies in farmed animals and represent an important risk for humans. In this work, 160 strains were isolated from soil of corn crops of which 10 showed antifungal activity against these phytopathogens, which, were identified as: Bacillus subtilis, Pseudomonas spp., Pseudomonas fluorescens, and Pantoea agglomerans by sequencing of 16S rRNA gene and the phylogenetic analysis. From cultures of each strain, extracellular filtrates were obtained and assayed to determine antifungal activity. The best filtrates were obtained in the stationary phase of B. subtilis cultures that were stable to the temperature and extreme pH values; in addition they did not show a cytotoxicity effect against brine shrimp and inhibited germination of conidia. The bacteria described in this work have the potential to be used in the control of white ear rot disease. PMID:22016606

  13. Enteric bacteria isolated from acute diarrheal patients in the Republic of Korea between the year 2004 and 2006.

    PubMed

    Cho, Seung-Hak; Shin, Hyun-Ho; Choi, Yeon-Hwa; Park, Mi-Sun; Lee, Bok-Kwon

    2008-06-01

    In an epidemiological survey of human enterobacterial infections in the Republic of Korea during three years from 2004 to 2006, we isolated 1,784 (6.2%, isolation rate of enteropathogens from stool samples) in 2004, 2,547 (9.5%) in 2005 and 3,506 bacteria (12.3%) from people who visited clinics. Among the isolated bacteria, pathogenic Escherichia coli, especially, EAEC was the most frequently identified pathogen in both urban and rural regions followed by Staphylococcus aureus, Salmonella species, Bacillus cereus, Vibrio parahaemolyticus, Campylobacter jejuni, Clostridium perfringens, and Shigella species. Distinct seasonality was found in V. parahaemolyticus species, while this pathogen showed no age-specific patterns. However, other bacteria, i.e., pathogenic E. coli, S. aureus, Salmonella spp., and B. cereus showed similar seasonality throughout the year, showing a slight increase in the infection rate during the summer months and high prevalence among children under 10 years of age and elder-age people. The antibiotic susceptibility patterns of pathogenic E. coli, Salmonella spp., and S. aureus showed high resistance to penicillins. However, both pathogenic E. coli and Salmonella spp. were susceptible to several cephems, imipenem, and amikacin. Moreover, S. aureus strains resistant to vancomycin were not found. In conclusion, these surveillances can play an important role for the control and prevention to the diseases originated by enteritis bacteria.

  14. Microbiota and anthropic interference on antimicrobial resistance profile of bacteria isolated from Brazilian Maned-wolf (Chrysocyon brachyurus).

    PubMed

    Vieira-da-Motta, Olney; Eckhardt-de-Pontes, Luiz Antonio; Petrucci, Melissa Paes; dos Santos, Israel Pereira; da Cunha, Isabel Candia Nunes; Morato, Ronaldo Gonçalves

    2013-12-01

    Both the study of Brazilian wild mammal fauna and the conditions that foster the preservation of endangered species, such as Brazilian Maned-wolf (Chrysocyon brachyurus), in wild life are of extreme importance. In order to study the resistance profile of microbiota bacterial colonizing Brazilian Maned-wolf, this work investigated samples from eight male captive and free roaming animals originating from different Brazilian geographical regions. Samples for microbiological purposes were collected with swabs and kept in appropriate transport medium. Using routine microbiological techniques, the isolated bacteria were tested toward antimicrobial drugs by the agar disk diffusion method. Results showed that all samples from wild animals were sensitive toward all drugs tested. Conversely, the resistance profile of bacteria isolated from captive animals varied among strains and animal body site location. Escherichia coli samples from prepuce, anus and ear showed multi-resistance toward at least four drugs, especially against erythromycin and tetracycline, followed by Proteus mirabilis and P. vulgaris strains isolated from anus and ear. Among Gram-positive bacteria, strains of coagulase-negative staphylococci showed multi-resistance mainly toward erythromycin and amoxicillin. The work discusses these findings and suggests that profile of multi-resistance bacteria from captive subjects may be attributed to direct contact with human or through lifestyle factors such as feeding, predation or contact of animals with urban animals such as birds, rodents, and insects from surrounding environments. PMID:24688529

  15. Isolation and characterization of alkane degrading bacteria from petroleum reservoir waste water in Iran (Kerman and Tehran provenances).

    PubMed

    Hassanshahian, Mehdi; Ahmadinejad, Mohammad; Tebyanian, Hamid; Kariminik, Ashraf

    2013-08-15

    Petroleum products spill and leakage have become two major environmental challenges in Iran. Sampling was performed in the petroleum reservoir waste water of Tehran and Kerman Provinces of Iran. Alkane degrading bacteria were isolated by enrichment in a Bushnel-Hass medium, with hexadecane as sole source of carbon and energy. The isolated strains were identified by amplification of 16S rDNA gene and sequencing. Specific primers were used for identification of alkane hydroxylase gene. Fifteen alkane degrading bacteria were isolated and 8 strains were selected as powerful degradative bacteria. These 8 strains relate to Rhodococcus jostii, Stenotrophomonas maltophilia, Achromobacter piechaudii, Tsukamurella tyrosinosolvens, Pseudomonas fluorescens, Rhodococcus erythropolis, Stenotrophomonas maltophilia, Pseudomonas aeruginosa genera. The optimum concentration of hexadecane that allowed high growth was 2.5%. Gas chromatography results show that all strains can degrade approximately half of hexadecane in one week of incubation. All of the strains have alkane hydroxylase gene which are important for biodegradation. As a result, this study indicates that there is a high diversity of degradative bacteria in petroleum reservoir waste water in Iran.

  16. Microbiota and anthropic interference on antimicrobial resistance profile of bacteria isolated from Brazilian maned-wolf (Chrysocyon brachyurus)

    PubMed Central

    Vieira-da-Motta, Olney; Eckhardt-de-Pontes, Luiz Antonio; Petrucci, Melissa Paes; dos Santos, Israel Pereira; da Cunha, Isabel Candia Nunes; Morato, Ronaldo Gonçalves

    2013-01-01

    Both the study of Brazilian wild mammal fauna and the conditions that foster the preservation of endangered species, such as Brazilian Maned-wolf (Chrysocyon brachyurus), in wild life are of extreme importance. In order to study the resistance profile of microbiota bacterial c