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Sample records for degrading bacterial strain

  1. Isolation of polyvinyl chloride degrading bacterial strains from ...

    African Journals Online (AJOL)

    Isolation of polyvinyl chloride degrading bacterial strains from environmental samples using enrichment culture technique. ... by their ability to release chloride from PVC polymer, increase their cell density in test media, carbon dioxide production and growth on the surface of PVC film in plate assay. ... Article Metrics.

  2. Carbazole degradation in the soil microcosm by tropical bacterial strains

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    Lateef B. Salam

    2015-01-01

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

  3. Isolation and characterization of organic-sulfur degradation bacterial strain

    Institute of Scientific and Technical Information of China (English)

    YANG Yu; DIAO Meng-xue; SHI Wu-yang; LI Li; DAI Qin-yun; QIU Guan-zhou

    2007-01-01

    A bacterial strain that was capable of degrading organic sulfur (dibenzothiophene) was isolated by enrichment techniques from the petroleum-contaminated soil collected from Zhongyuan Oil Field. The strain is named ZYX and is gram-positive.This strain undergoes bacilus-coccus morphological change, and forms yellow-pigment glossy circular colonies with 1.5 mm in diameter on average after 2 d incubation on Luria-Bertani(LB) plates. The full-length of 16S rDNA sequence of strain ZYX was determined and analyzed. Strain ZYX is found most relative with the genus of Arthrobacter. The similarity values between ZYX and Arthrobacter sp. P2 is 99.53%. The main morphological, biochemical and physiological features of strain ZYX accord with those of Arthrobacter. It is found that the optimal initial pH for growth is about 7.0, and the optimal concentration of dibenzothiophene(DBT)for growth is 0.10 g/L. Additionally, the results show that the best carbon source and nitrogen source are glycerol and glutamine,respectively.

  4. Optimized cultivation of highly-efficient degradation bacterial strains and their degradation ability towards pyrene

    Institute of Scientific and Technical Information of China (English)

    HOU Shuyu; ZHANG Qingmin; DUO Miao; ZHANG Yang; SUN Hongwen

    2007-01-01

    Two bacterial strains,Pyl and Py4,have been tamed and isolated through long cultivation with polycyclic aromatic hydrocarbon-pyrene as the single carbon source.It has been proven that they are both highly-efficient pyrene degrading bacteria and both Bacillus sp..The pyrene degradation ability of separated Pyl,Py4 and the consortium of equal Pyl and Py4 was studied in this project.It is shown that pyrene degradation rates were 88% in 10hr by Py1,84% in 14hr by Py4,and 88% in 8hr by the consortium.It was also determined that the best degradation temperatures were 37℃ and pH 7.0 respectively.The influence of different nutrient substrates added in the degradation experiments was also studied.It was shown that sodium salicylate,sodium acetate and yeast exuact had obvious simulative effect,but glucose had no obvious effect.

  5. Isolation and characterization of a bacterial strain that efficiently degrades sex steroid hormones

    Institute of Scientific and Technical Information of China (English)

    JI Shulan; LIU Zhipei; LIU Zhipeng; REN Haiyan

    2007-01-01

    A bacterial strain,ZY3,growing on sex steroid hormones as the sole source of carbon and energy was isolated from the sewage treatment plant of a prophylactic steroids factory.ZY3 degrades the 3-methoxy-17β-hyclroxy-1,3,5(10),8(9)-δ-4-estren (MHE).This strain was preliminarily identified as Raoultella sp.ZY3 according to its morphology and its 16S rRNA gene sequence.During the experimental period (72 h),the optimum temperature,pH and 3-MHE concentration for the degradation of hydride by the strain ZY3 were 35℃,10 and 10 mg/L,respectively.The degradation rate of the sex steroid hormones increased to 87% and 85% after the addition of maltose and peptone,respectively.

  6. Regional analysis of potential polychlorinated biphenyl degrading bacterial strains from China

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    Jianjun Shuai

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

  7. Isolation and characteristics of a novel biphenyl-degrading bacterial strain, Dyella ginsengisoli LA-4

    Institute of Scientific and Technical Information of China (English)

    LI Ang; QU Yuanyuan; ZHOU Jiti; GOU Min

    2009-01-01

    A novel biphenyl-degrading bacterial strain LA-4 was isolated from activated sludge. It was identified as Dyella ginsengisoli according to phylogenetic similarity of 16S rRNA gene sequence. This isolate could utilize biphenyl as sole source of carbon and energy, which degraded over 95 mg/L biphenyl within 36 h. The major metabolites formed from biphenyl, such as 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid (HOPDA) and benzoic acid, were identified by LC-MS. The crude cell extract of strain LA-4 exhibited the activity of 2,3-dihydroxybiphenyl 1,2-dioxygenase (2,3-DHBD) and the kinetic parameters were Km= 26.48 μmol/L and Vmax= 8.12 μmol/mg protein. A conserved region of the biphenyl dioxygenase gene bphA1 of strain LA-4 was amplified by PCR and confirmed by DNA sequencing.

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

    Science.gov (United States)

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

    2016-11-01

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

  9. New bacterial strain of the genus Ochrobactrum with glyphosate-degrading activity.

    Science.gov (United States)

    Hadi, Faranak; Mousavi, Amir; Noghabi, Kambiz Akbari; Tabar, Hadi Ghaderi; Salmanian, Ali Hatef

    2013-01-01

    Thirty bacterial strains with various abilities to utilize glyphosate as the sole phosphorus source were isolated from farm soils using the glyphosate enrichment cultivation technique. Among them, a strain showing a remarkable glyphosate-degrading activity was identified by biochemical features and 16S rRNA sequence analysis as Ochrobactrum sp. (GDOS). Herbicide (3 mM) degradation was induced by phosphate starvation, and was completed within 60 h. Aminomethylphosphonic acid was detected in the exhausted medium, suggesting glyphosate oxidoreductase as the enzyme responsible for herbicide breakdown. As it grew even in the presence of glyphosate concentrations as high as 200 mM, Ochrobactrum sp. could be used for bioremediation purposes and treatment of heavily contaminated soils.

  10. Isolation of bacterial strains from bovine fecal microflora capable of degradation of ceftiofur.

    Science.gov (United States)

    Rafii, Fatemeh; Williams, Anna J; Park, Miseon; Sims, Lillie M; Heinze, Thomas M; Cerniglia, Carl E; Sutherland, John B

    2009-10-20

    Ceftiofur, a third-generation cephalosporin used to treat bacterial infections in animals, is degraded in bovine feces but the specific bacteria involved are unknown. To find the bacteria involved in ceftiofur metabolism, the bovine fecal microflora was screened. Twenty-one nonidentical strains of bovine fecal bacteria were isolated on media containing 1-32 microg ml(-1) of ceftiofur. The cultures were incubated with 5 microg ml(-1) ceftiofur for different times, then centrifuged and analyzed by high-performance liquid chromatography. Three strains of Bacillus spp., two strains of Roseomonas spp., and one strain of Azospirillum sp. metabolized 5 microg ml(-1) ceftiofur in broth cultures in less than 24h; ten other strains of Roseomonas and one strain of Bacillus pumilus had metabolized it by 120 h. After the ceftiofur had been metabolized by these bacteria, the filter-sterilized supernatants of centrifuged cultures no longer inhibited the growth of a ceftiofur-sensitive strain of Kocuria rhizophila, which indicated that ceftiofur had been transformed to compounds without bactericidal activity. Each isolate was also found to be able to grow in the presence of other beta-lactams, and a nitrocefin assay showed beta-lactamase activity in the 17 strains that metabolized ceftiofur. The results show that some beta-lactamase-producing bacteria from the bovine fecal microflora are capable of transforming ceftiofur to metabolites lacking bactericidal activity.

  11. Isolation and molecular characterisation of malathion-degrading bacterial strains from waste water in Egypt

    Directory of Open Access Journals (Sweden)

    Zeinat K. Mohamed

    2010-04-01

    Full Text Available Efficiencies of local bacterial isolates in malathion degradation were investigated. Five bacterial isolates obtained from agricultural waste water were selected due to their ability to grow in minimal salt media, supplied with 250 ppm malathion as sole source of carbon and phosphorus. The purified bacterial isolates (MOS-1, MOS-2, MOS-3, MOS-4 and MOS-5 were characterised and identified using a combination of cellular profile (SDS-PAGE, genetic make up profile (RAPD-PCR, and morphological and biochemical characteristics. Four bacterial isolates (MOS-1, MOS-2, MOS-3 and MOS-4 with identical genetic characteristics were identified as Enterobacter aerogenes, whereas isolate MOS-5 was identified as Bacillus thuringiensis. The degradation rate of malathion in liquid culture was estimated during 15 days of incubation for the isolate MOS-5 of B. thuringiensis. Slightly more than 50% of the initial malathion was decomposed within 3 days. The malathion concentration decreased to almost 17% in the inoculated medium after 10 days incubation, while more than 91% of the initial malathion was degraded after 15 days.

  12. Enhanced Degradation of Diesel in the Rhizosphere of after Inoculation with Diesel-Degrading and Plant Growth-Promoting Bacterial Strains.

    Science.gov (United States)

    Balseiro-Romero, María; Gkorezis, Panagiotis; Kidd, Petra S; Vangronsveld, Jaco; Monterroso, Carmen

    2016-05-01

    The association of plants and rhizospheric bacteria provides a successful strategy to clean up contaminated soils. The purpose of this work was to enhance diesel degradation in rhizosphere by inoculation with selected bacterial strains: a diesel degrader (D), plant growth-promoting (PGP) strains, or a combination (D+PGP). Plants were set up in pots with the A or B horizon of an umbric Cambisol (A and B) spiked with diesel (1.25%, w/w). After 1 mo, the dissipation of diesel range organics (DRO) with respect to = 0 (i.e., 1 wk after preparing the pots with the seedlings) concentration was significantly higher in inoculated than in noninoculated (NI) pots: The highest DRO losses were found in A D+PGP pots (close to 15-20% higher than NI) and in B D pots (close to 10% higher). The water-extractable DRO fraction was significantly higher at = 30 d (15-25%) compared with = 0 (<5%), probably due to the effects of plant root exudates and biosurfactants produced by the degrader strain. The results of this experiment reflect the importance of the partnerships between plants and bacterial inoculants and demonstrate the relevance of the effect of bacterial biosurfactants and plant root exudates on contaminant bioavailability, a key factor for enhancing diesel rhizodegradation. The association of lupine with D and PGP strains resulted in a promising combination for application in the rhizoremediation of soils with moderate diesel contamination.

  13. Bacterial degradation of aminopyrine.

    Science.gov (United States)

    Blecher, H; Blecher, R; Wegst, W; Eberspaecher, J; Lingens, F

    1981-11-01

    1. Four strains of bacteria growing with aminopyrine as sole source of carbon were isolated from soil and were identified as strains of Phenylobacterium immobilis. 2. Strain M13 and strain E, the type species of Phenylobacterium immobilis (DSM 1986), which had been isolated by enrichment with chloridazon (5-amino-4-chloro-2-phenyl-2H-pyridazin-3-one) were used to investigate the bacterial degradation of aminopyrine. 3. Three metabolites were isolated and identified as: 4-(dimethylamino)-1,2-dihydro-1,5-dimethyl-2-(2,3-dihydro-2,3-dihydroxy-4,6-cyc lohexadien-1-yl)-3H-pyrazol-3-one, 4-(dimethylamino)-1,2-dihydro-1,5-dimethyl-2-(2,3-dihydroxyphenyl)-3H-pyrazol-3 -one and 4-(dimethylamino)-1,2-dihydro-1,5-dimethyl-3H-pyrazol-3-one. 4. An enzyme extract from cells of strain m13 was shown to further metabolize the catechol derivative of aminopyrine, with the formation of 2-pyrone-6-carboxylic acid. 5. Results indicate that the benzene ring of aminopyrine is the principal site of microbial metabolism.

  14. Isolation, characterization and phylogenetic analysis of a bacterial strain capable of degrading acetamiprid

    Institute of Scientific and Technical Information of China (English)

    YAO Xiao-hua; MIN Hang

    2006-01-01

    An aerobic bacterium, capable of degrading the new chloronicotine pesticide acetamiprid, was isolated from the sludge of pesticide factory after successive enrichment cultures and named strain FH2 which is a Gram-negative, rod-shaped, obligate aerobic organism with ((0.5-0.7) ×(1.5-3.0))μm of cell size and with monotrichous flagellum. It was identified as a member of Pseudomonas sp. based on morphology, physio-biochemical properties, Biolog GN2, 16S rDNA sequence and phylogenetic characteristic analysis. The isolate could grow optimally at pH 7.0 and 30℃ in acetamiprid-mineral medium with 800 mg/L concentration. About 53.3% acetamiprid was degraded by strain FH2 after incubation for 14 d in acetamiprid-mineral medium and nearly 96.7% degraded when incubated in acetamiprid-yeast mineral medium at 30℃ for 14 d. This paper describes phylogenetic and degradation characterization of a pure bacterium being able to mineralize acetamiprid for the first time.

  15. [Isolation and identification of a bacterial strain JS018 capable of degrading several kinds of organophosphate pesticides].

    Science.gov (United States)

    Jiang, Yu-Ji; Deng, You-Jin; Liu, Xin-Rui; Xie, Bao-Gui; Hu, Fang-Ping

    2006-06-01

    Organophosphate pesticides are used widely all over the world and play an important role in plant pest control. However these pesticides are considered as pollutants and harmful to human health. To search for microorganisms that can degrade organophosphate pesticides with high efficiency, a bacterial strain, coded as JS018, was isolated and screened from the soil in the vicinity of Shanming Pesticides Factory, Shanming, Fujian. Laboratory tests showed that the bacterium could degrade several kinds of organophosphate pesticides, such as Parathion-methyl and phoxin. The strain's degrading rates on phoxin, Parathion-methyl, hostathion and dichlorvos in LB liquid fermentation medium for 36 h were 99%, 96%, 80.4% and 69.0% respectively. The bacterial colonies on LB plate appeared shiny and pale-pink in color. The bacteria were Gram-negative coccoids, 0.5 - 0.7 microm in diameter. They grew well at 30 - 38 degrees C and pH 7.0 - 9.0. The optimal temperature and pH for cell growth was 32 degrees C and pH 7.5 - 8.0, respectively. They did not grow in medium containing 6% or more NaCl. The antibiotic susceptibility tests showed that the strain was resistant to ampicillin, penicillin and lincomycin. It was sensitive to kanamycin, tetracycline and gentamicin. Laboratory tests also showed that the strain could ferment D-glucose, trehalose, melezitose and ethanol. It was negative in the production of indole and hydrogen sulfide. It could not liquefy gelatin, utilize citrate, nor ferment L-arabinose, sucrose, D-mannitol, D-xylose, fructose, D-galactose, maltose or lactose. The catalase, urease and nitrate reduction were positive. Based on its morphological, physiological and biochemical properties as well as the 16S rDNA sequence analysis result, the strain was tentatively identified as Roseomonas sp.

  16. Growth kinetics of a diesel-degrading bacterial strain from petroleum-contaminated soil.

    Science.gov (United States)

    Dahalan, S F A; Yunus, I; Johari, W L W; Shukor, M Y; Halmi, M I E; Shamaan, N A; Syed, M A

    2014-03-01

    A diesel-degrading bacterium was isolated from a diesel-contaminated site in Selangor, Malaysia. The isolate was tentatively identified as Acinetobacter sp. strain DRY12 based on partial 16S rDNA molecular phylogeny and Biolog GN microplate panels and Microlog database. Optimum growth occurred from 3 to 5% diesel and the strain was able to tolerate as high as 8% diesel. The optimal pH that supported growth of the bacterium was between pH 7.5 to 8.0. The isolate exhibited optimal growth in between 30 and 35 degrees C. The best nitrogen source was potassium nitrate (between 0.6 and 0.9% (w/v)) followed by ammonium chloride, sodium nitrite and ammonium sulphate in descending order. An almost complete removal of diesel components was seen from the reduction in hydrocarbon peaks observed using Solid Phase Microextraction Gas Chromatography analysis after 10 days of incubation. The best growth kinetic model to fit experimental data was the Haldane model of substrate inhibiting growth with a correlation coefficient value of 0.97. The maximum growth rate- micromax was 0.039 hr(-1) while the saturation constant or half velocity constant Ks and inhibition constant Ki, were 0.387% and 4.46%, respectively. MATH assays showed that 75% of the bacterium was found in the hexadecane phase indicating that the bacterium was hydrophobic. The characteristics of this bacterium make it useful for bioremediation works in the Tropics.

  17. Bioremediation of Cd and carbendazim co-contaminated soil by Cd-hyperaccumulator Sedum alfredii associated with carbendazim-degrading bacterial strains.

    Science.gov (United States)

    Xiao, Wendan; Wang, Huan; Li, Tingqiang; Zhu, Zhiqiang; Zhang, Jie; He, Zhenli; Yang, Xiaoe

    2013-01-01

    The objective of this study was to develop a bioremediation strategy for cadmium (Cd) and carbendazim co-contaminated soil using a hyperaccumulator plant (Sedum alfredii) combined with carbendazim-degrading bacterial strains (Bacillus subtilis, Paracoccus sp., Flavobacterium and Pseudomonas sp.). A pot experiment was conducted under greenhouse conditions for 180 days with S. alfredii and/or carbendazim-degrading strains grown in soil artificially polluted with two levels of contaminants (low level, 1 mg kg(-1) Cd and 21 mg kg(-1) carbendazim; high level, 6 mg kg(-1) Cd and 117 mg kg(-1) carbendazim). Cd removal efficiencies were 32.3-35.1 % and 7.8-8.2 % for the low and high contaminant level, respectively. Inoculation with carbendazim-degrading bacterial strains significantly (P soil microbial biomass, dehydrogenase activities and microbial diversities by 46.2-121.3 %, 64.2-143.4 %, and 2.4-24.7 %, respectively. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis revealed that S. alfredii stimulated the activities of Flavobacteria and Bradyrhizobiaceae. The association of S. alfredii with carbendazim-degrading bacterial strains enhanced the degradation of carbendazim by changing microbial activity and community structure in the soil. The results demonstrated that association of S. alfredii with carbendazim-degrading bacterial strains is promising for remediation of Cd and carbendazim co-contaminated soil.

  18. Bacterial Degradation of Pesticides

    DEFF Research Database (Denmark)

    Knudsen, Berith Elkær

    . Bioaugmentation i.e. addition of specific degrader organisms, has been suggested as an environmentally friendly and economically competitive strategy for cleaning polluted sites. Several organisms have been isolated, capable of degrading different compounds. However the capacity to degrade the desired compound...... SRS2, Variovorax SRS16 and Arthrobacter globiformis D47. The degradation capacity of each strain individually as well as two- and three-member consortia was studied in a sand column set up. Glass beads were added to the set up to create a dry patch, separating the organisms and the diuron-spiked sand...

  19. Bioremediation of petroleum based contaminants with biosurfactant produced by a newly isolated petroleum oil degrading bacterial strain

    Directory of Open Access Journals (Sweden)

    Debajit Borah

    2017-03-01

    Full Text Available Petroleum based hydrocarbon degrading and biosurfactant producing bacterial strain was isolated from an automobile engine. The strain was identified as Bacillus cereus DRDU1 on the basis of 16S rDNA sequencing analysis. The strain was found to be efficiently degrading 96% of kerosene making it a potential tool for bioremediation of petroleum based contaminants. Production and optimization of the biosurfactant produced by the isolate were also carried out. Surface hydrophobicity trait of isolate was found to be 60.67 ± 1.53% and foaming percentage of the crude biosurfactant was found to be 31.33 ± 0.58%. The presence of amino acids and sugar moieties in the biosurfactant was confirmed by biochemical tests and were further validated by FTIR (the Fourier transform infrared spectrometric analysis revealing the presence of υOH, υCOO, υCOOH, υCH (stretching, υNH, υCH2, υCH3, and υCH (bending, and υCO (ester in the surfactant. The decrease in contact angle of hydrocarbon oil from (30.67 ± 1.15° to (21.3 ± 1.53° respectively after 3 and 6 days of incubation reveals its potential to emulsify petroleum oil. Further, emulsification index (E24 of biosurfactant against kerosene, crude oil, and used engine oil were determined to be 55.33 ± 1.53%, 29.67 ± 1.53%, and 20 ± 1% respectively which attracts its future application in MEOR (microbial enhanced oil recovery process.

  20. Bacterial Degradation of Pesticides

    DEFF Research Database (Denmark)

    Knudsen, Berith Elkær

    could potentially improve bioremediation of BAM. An important prerequisite for bioaugmentation is the potential to produce the degrader strain at large quantities within reasonable time. The aim of manuscript II, was to optimize the growth medium for Aminobacter MSH1 and to elucidate optimal growth...

  1. High performance degradation of azo dye Acid Orange 7 and sulfanilic acid in a laboratory scale reactor after seeding with cultured bacterial strains.

    Science.gov (United States)

    Coughlin, Michael F; Kinkle, Brian K; Bishop, Paul L

    2003-06-01

    Bacterial strains 1CX and SAD4i--previously isolated from the mixed liquor of a municipal sewage treatment plant--are capable of degrading the azo dye Acid Orange 7 (AO7) and sulfanilic acid, respectively. A rotating drum bioreactor (RDBR), operating under continuous flow and nutrient conditions designed to simulate the effluent from a dye manufacturing plant, was seeded with strains 1CX and SAD4i, forming a biofilm capable of degrading AO7 and sulfanilic acid. In addition, an RDBR containing a pre-existing biofilm capable of degrading AO7, but not sulfanilic acid, was seeded with strain SAD4i alone. Strain SAD4i was incorporated into the existing biofilm and degraded the sulfanilic acid resulting from the degradation of AO7 by indigenous members of the biofilm. The ability to seed a bioreactor with bacterial strains capable of degrading azo dyes, and resulting by-products, in a mixed microbial community suggests that this process could have commercial applications.

  2. 油脂降解菌种的鉴定及降解条件优化%Identification of Oil Degradable Bacterial Strain & Optimization of Degradation Condition

    Institute of Scientific and Technical Information of China (English)

    张印; 薛永常

    2015-01-01

    从学校食堂排放的废水中筛选出1株油脂降解菌株,经形态特征、生理生化特征、16S rDNA 同源性序列分析,鉴定为克雷伯氏菌属,暂命名为 Klebsiella sp. X-1。并利用正交实验进一步考察了 pH、培养温度、摇床转速对油脂降解率的影响。实验结果表明,在高含油废水培养基中,pH 7.0、转速为140 r/ min、培养温度为30℃时,72 h 内该菌的油脂降解率最高达68.2%。%An oil degradable bacterial strain was screened from wastewater discharged from the university dining hall. It was identified as Klebsiella sp. X-1 through its morphological,physiological and biochemical features,and 16S rDNA homology sequencing analysis. The effects of pH,temperature,and shaking rpm on oil degradation were further observed adopted with orthogonal experiment. The results showed that within 72 hours,in the high oily wastewater me-dium,the optimum process conditions were as follows:pH 7,shaking at 140 r/ min,cultured at 30 ℃,the oil de-gradable rate of the strain reached at the highest of 68. 2% .

  3. Isolation of bacterial strains able to degrade biphenyl, diphenyl ether and the heat transfer fluid used in thermo-solar plants.

    Science.gov (United States)

    Blanco-Moreno, Rafael; Sáez, Lara P; Luque-Almagro, Víctor M; Roldán, M Dolores; Moreno-Vivián, Conrado

    2017-03-25

    Thermo-solar plants use eutectic mixtures of diphenyl ether (DE) and biphenyl (BP) as heat transfer fluid (HTF). Potential losses of HTF may contaminate soils and bioremediation is an attractive tool for its treatment. DE- or BP-degrading bacteria are known, but up to now bacteria able to degrade HTF mixture have not been described. Here, five bacterial strains which are able to grow with HTF or its separate components DE and BP as sole carbon sources have been isolated, either from soils exposed to HTF or from rhizospheric soils of plants growing near a thermo-solar plant. The organisms were identified by 16S rRNA gene sequencing as Achromobacter piechaudii strain BioC1, Pseudomonas plecoglossicida strain 6.1, Pseudomonas aeruginosa strains HBD1 and HBD3, and Pseudomonas oleovorans strain HBD2. Activity of 2,3-dihydroxybiphenyl dioxygenase (BphC), a key enzyme of the biphenyl upper degradation pathway, was detected in all isolates. Pseudomonas strains almost completely degraded 2000ppm HTF after 5-day culture, and even tolerated and grew in the presence of 150,000ppm HTF, being suitable candidates for in situ soil bioremediation. Degradation of both components of HTF is of particular interest since in the DE-degrader Sphingomonas sp. SS3, growth on DE or benzoate was strongly inhibited by addition of BP.

  4. Isolation and characterization of a potential paraffin-wax degrading thermophilic bacterial strain Geobacillus kaustophilus TERI NSM for application in oil wells with paraffin deposition problems.

    Science.gov (United States)

    Sood, Nitu; Lal, Banwari

    2008-02-01

    Paraffin deposition problems, that have plagued the oil industry, are currently remediated by mechanical and chemical means. However, since these methods are problematic, a microbiological approach has been considered. The bacteria, required for the mitigation of paraffin deposition problems, should be able to survive the high temperatures of oil wells and degrade the paraffins under low oxygen and nutrient conditions while sparing the low carbon chain paraffins. In this study, a thermophilic paraffinic wax degrading bacterial strain was isolated from a soil sample contaminated with paraffinic crude oil. The selected strain, Geobacillus TERI NSM, could degrade 600mg of paraffinic wax as the sole carbon source in 1000ml minimal salts medium in 7d at 55 degrees C. This strain was identified as Geobacillus kaustophilus by fatty acid methyl esters analysis and 16S rRNA full gene sequencing. G. kaustophilus TERI NSM showed 97% degradation of eicosane, 85% degradation of pentacosane and 77% degradation of triacontane in 10d when used as the carbon source. The strain TERI NSM could also degrade the paraffins of crude oil collected from oil wells that had a history of paraffin deposition problems.

  5. Isolation and characterization of a cold-resistant PCB209-degrading bacterial strain from river sediment and its application in bioremediation of contaminated soil.

    Science.gov (United States)

    Qiu, Liping; Wang, Hu; Wang, Xuntao

    2016-01-01

    A cold-resistant bacterium (strain QL) that can degrade 2,2',3,3',4,4',5,5',6,6'-decachlorobiphenyl (PCB209) was isolated from Wei-he River sediment. Strain QL was identified as a rod-shaped gram-negative bacterial strain, which was further identified as Comamonas testosteroni. C. testosteroni has never been reported to be capable of degrading PCB209 at low temperatures. In this study, the degradation characteristics showed that strain QL could grow with PCB209 as the sole carbon source at low temperatures (10 ± 0.5 °C). More significantly, strain QL of 40% inoculation volume was able to completely degrade PCB209 in 140 h (initial concentration of PCB209 was 100-500 µg L(-1) at 10 ± 0.5 °C and pH 7-8). The degradation process proceeded with zero-order reaction kinetics. Moreover, both laboratory simulation and real-world field experiments demonstrated that strain QL was effective in practical applications of PCB209 biodegradation in contaminated soil.

  6. Microcystin-degrading activity of an indigenous bacterial strain Stenotrophomonas acidaminiphila MC-LTH2 isolated from Lake Taihu.

    Directory of Open Access Journals (Sweden)

    Fei Yang

    Full Text Available Microcystin-LR (MC-LR and microcystin-RR (MC-RR produced by harmful cyanobacterial blooms (HCBs pose substantial threats to the ecosystem and public health due to their potential hepatotoxicity. Degradation of microcystins (MCs by indigenous bacteria represents a promising method for removing MCs from fresh water without harming the aquatic environment, but only a few microcystin (MC-degrading bacteria have been isolated and had their mechanisms reported. This study aimed to isolate indigenous bacteria from Lake Taihu, and investigate the capability and mechanism of MC degradation by these bacteria. During a Microcystis bloom, an indigenous MC-degrading bacterium designated MC-LTH2 was successfully isolated from Lake Taihu, and identified as Stenotrophomonas acidaminiphila based on phylogenetic analysis. In the presence of MC-LR together with MC-RR, the strain MC-LTH2 was capable of totally degrading both simultaneously in 8 days, at rates of 3.0 mg/(L⋅d and 5.6 mg/(L⋅d, respectively. The degradation rates of MCs were dependent on temperature, pH, and initial MC concentration. Adda (3-amino-9-methoxy-2, 6, 8-trimethyl-10-phenyldeca-4, 6-dienoic acid was detected as an intermediate degradation product of MCs using high performance liquid chromatography coupled with time-of-flight mass spectrometry (HPLC-TOF-MS. To the best of our knowledge, this is the first report of Stenotrophomonas acidaminiphila capable of degrading two MC analogues and other compounds containing Adda residue completely under various conditions, although the mlrA gene in the strain was not detected. These results indicate the Stenotrophomonas acidaminiphila strain MC-LTH2 possesses a significant potential to be used in bioremediation of water bodies contaminated by MC-LR and MC-RR, and is potentially involved in the degradation of MCs during the disappearance of the HCBs in Lake Taihu.

  7. Bacterial isolates degrading aliphatic polycarbonates.

    Science.gov (United States)

    Suyama, T; Hosoya, H; Tokiwa, Y

    1998-04-15

    Bacteria that degrade an aliphatic polycarbonate, poly(hexamethylene carbonate), were isolated from river water in Ibaraki. Prefecture, Japan, after enrichment in liquid medium containing poly(hexamethylene carbonate) suspensions as carbon source, and dilution to single cells. Four of the strains, 35L, WFF52, 61A and 61B2, degraded poly(hexamethylene carbonate) on agar plate containing suspended poly(hexamethylene carbonate). Degradation of poly(hexamethylene carbonate) was confirmed by gel permeation chromatography. Besides poly(hexamethylene carbonate), the strains were found to degrade poly(tetramethylene carbonate). The strains were characterized morphologically, physiologically, and by 16S rDNA sequence analysis. Strains 35L and WFF52 were tentatively identified as Pseudomonas sp. and Variovorax sp., respectively, while strains 61A and 61B2 constitute an unidentified branch within the beta subclass of the Proteobacteria.

  8. Biosurfactant production from marine hydrocarbon-degrading consortia and pure bacterial strains using crude oil as carbon source

    Directory of Open Access Journals (Sweden)

    Eleftheria eAntoniou

    2015-04-01

    Full Text Available Biosurfactants (BS are green amphiphilic molecules produced by microorganisms during biodegradation, increasing the bioavailability of organic pollutants. In this work, the BS production yield of marine hydrocarbon degraders isolated from Elefsina bay in Eastern Mediterranean Sea has been investigated. The drop collapse test was used as a preliminary screening test to confirm biosurfactant producing strains or mixed consortia. The community structure of the best consortia based on the drop collapse test was determined by 16S-rDNA pyrotag screening. Subsequently, the effect of incubation time, temperature, substrate and supplementation with inorganic nutrients, on biosurfactant production, was examined. Two types of BS - lipid mixtures were extracted from the culture broth; the low molecular weight BS Rhamnolipids and Sophorolipids. Crude extracts were purified by silica gel column chromatography and then identified by thin layer chromatography (TLC and Fourier transform infrared spectroscopy (FT-IR. Results indicate that biosurfactant production yield remains constant and low while it is independent of the total culture biomass, carbon source, and temperature. A constant BS concentration in a culture broth with continuous degradation of crude oil implies that the BS producing microbes generate no more than the required amount of biosurfactants that enables biodegradation of the crude oil. Isolated pure strains were found to have higher specific production yields than the complex microbial marine community-consortia. The heavy oil fraction of crude oil has emerged as a promising substrate for BS production (by marine BS producers with fewer impurities in the final product. Furthermore, a particular strain isolated from sediments, Paracoccus marcusii, may be an optimal choice for bioremediation purposes as its biomass remains trapped in the hydrocarbon phase, not suffering from potential dilution effects by sea currents.

  9. Bacterial degradation of detergent compounds.

    Science.gov (United States)

    Goodnow, R A; Harrison, A P

    1972-10-01

    A survey for surfactant degradation among aerobic bacteria has been undertaken. Tests have been made in peptone medium where such a degradation, if it occurs, will be gratuitous. Tallow-alkyl-sulfate, alkyl-ethoxylate-sulfate, and linear-alkyl-benzene-sulfonate were used. Forty-five strains of 34 species in 19 genera degrade one or more of these detergent compounds. With some species, the surfactant inhibits degradation without inhibiting growth, whereas with one species slight degradation took place even at a toxic concentration of surfactant.

  10. Bacterial Degradation of Aromatic Compounds

    Directory of Open Access Journals (Sweden)

    Qing X. Li

    2009-01-01

    Full Text Available Aromatic compounds are among the most prevalent and persistent pollutants in the environment. Petroleum-contaminated soil and sediment commonly contain a mixture of polycyclic aromatic hydrocarbons (PAHs and heterocyclic aromatics. Aromatics derived from industrial activities often have functional groups such as alkyls, halogens and nitro groups. Biodegradation is a major mechanism of removal of organic pollutants from a contaminated site. This review focuses on bacterial degradation pathways of selected aromatic compounds. Catabolic pathways of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene are described in detail. Bacterial catabolism of the heterocycles dibenzofuran, carbazole, dibenzothiophene, and dibenzodioxin is discussed. Bacterial catabolism of alkylated PAHs is summarized, followed by a brief discussion of proteomics and metabolomics as powerful tools for elucidation of biodegradation mechanisms.

  11. Bacterial degradation of fungicide captan.

    Science.gov (United States)

    Megadi, Veena B; Tallur, Preeti N; Mulla, Sikandar I; Ninnekar, Harichandra Z

    2010-12-22

    The phthalimide fungicide captan has been widely used to control plant pathogenic fungi. A strain of Bacillus circulans utilized the fungicide captan as sole source of carbon and energy. The organism degraded captan by a pathway involving its initial hydrolysis to yield cis-1,2,3,6-tetrahydrophthalimide, a compound without fungicidal activity. The formation of this compound was confirmed by HPLC, IR, NMR, and mass spectral analysis. The results also revealed that cis-1,2,3,6-tetrahydrophthalimide was further degraded to o-phthalic acid by a protocatechuate pathway. These findings indicated that there was a complete mineralization of fungicide captan by B. circulans.

  12. 石油降解菌株的分离鉴定及降油特性%Isolation and Identification of Petroleum-Degradable Bacterial Strain and Its Oil-Degradation Characteristics

    Institute of Scientific and Technical Information of China (English)

    雒晓芳; 杨琴; 陈丽华; 周立辉; 徐红伟

    2012-01-01

    从甘肃华庆油田污染严重的土壤中采样,通过富集培养、多次筛选分离得到1株优势菌F1.依据生理生化特征和16S rDNA序列将菌株F1鉴定为白色类诺卡氏菌(Nocardioides albus).GS-MC结果表明,等量原油经F1菌株降解前、后,表现出先降解高碳数正构烷烃为低碳数正构烷烃;高碳数正构烷烃中奇数碳向偶数碳正构烷烃演化规律;平均降油率为64%,F1菌株能较好地促使五环三萜类化合物立体构型中不稳定构型向稳定性构型转化.F1菌株在含油浓度0.3%、0.5%、1.0%土样中降解石油烃的半衰期分别为17.2、18.2、23.7 d,42 d后均达到78%以上.%An oil-degradation bacterial dominant strain F, was screened and isolated from seriously oil-contaminated soil sampled at Huaqing Oilfield in Gansu Province through enrichement cultivation and multiple screening. Based on physio-biochemical characters and 16S rDNA sequencing indicate that the strain F1 was identified preliminarily as Ao-cardioides albus. The general law is that after treated with strain F1 , the higher molecular weight n-alkanes were deg-radated into lower molecular weight n-alkanes, and the n-alkanes in odd-numbered carbon were degradaled into n-al-kanes in even-numbered carbon, as revealed by GS-MC. The average oil-degradation rate was 64% , and the strain F, could promote the transition from less stable configuration in pentacyclic triterpenes to stable one. In addition, it was shown that the TPH degradation rate of the strain F1 was higher than 78% after 42 days, the degradation half-life of petroleum were about 17. 2、18.2、23.7 days under different petroleum-contaminated soils respectively.

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

    Science.gov (United States)

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

    2014-10-01

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

  14. Isolation and identification of bacterial strains efficient degrading formaldehyde and their degrading characteristics%高效降解甲醛菌株的分离鉴定及其特性

    Institute of Scientific and Technical Information of China (English)

    谢文娟; 王洁; 孙佩石; 邹平

    2011-01-01

    In this paper, two newly isolated bacterial strain Al and strain A2, which were capable of degrading formaldehyde in high efficiency, were identified based on the results of standard morphological identification, physiological and biochemical characters, 16S rDNA sequence analysis. Their capability of degrading formaldehyde was investigated by determination of the formaldehyde concentration change in culture. The biological packed tower hung membrane experiment was carried to determine the purification performance of the two bacterial to formaldehyde gas. The results showed that: these two bacterial strain Al and strain A2 were identified as Pseudomonas and Sphingomonas, respectively; when formaldehyde initial concentration was below 1 200 mg/L, it could be degraded by bacteria strain Aland strain A2 completely; when original formaldehyde concentration was up to 1600 mg/L, 50% of formaldehyde was consumed by strain Al after 48 h, 74.3% of formaldehyde was consumed bystrain A2 after 104 h; the removal efficiency of these two bacteria could be over 99%, the formaldehyde removal biochemical can amount to 26.4 mg/(L-h) of strain Al and 20.6 mg/(L·h) of strain A2.%首先对新分离的、能高效降解甲醛的两菌株A1和A2在形态学特征、生理生化特性及16S rDNA序列分析等方面进行了系统研究;随后通过测定在液体培养过程中甲醛浓度的变化,确定新分离菌株A1、A2降解溶液中甲醛的性能;最后利用菌株A1、A2分别进行生物填料塔的挂膜实验,确定其对甲醛气体的净化性能.结果表明:菌株A1属于假单胞菌属(Pseudomonas),菌株A2为鞘氨醇单胞菌属(Sphingomonas);当甲醛初始浓度<1 200 mg/L时,菌株A1、A2都能完全降解 溶液中的甲醛,当甲醛浓度增高至1 600 mg/L时,菌株A1在48 h后的甲醛降解率为50%,菌株A2在104 h后的甲醛降解率为74.3%;菌株A1、A2对甲醛气体的净化效率均能达到99%以上,菌株A1的

  15. Screening, Identification and Degrading Characteristics of A Phenol Degrading Bacterial Strain%一株苯酚降解菌的筛选、鉴定及其降解特性

    Institute of Scientific and Technical Information of China (English)

    刘鸿杰; 何熙璞; 张敏; 梁锦添; 陈加辉; 李俊芳; 陈保善

    2011-01-01

    By gradually increasing the concentration of phenol in the culture medium, a phenol-degrading bacterial strain designated as F5-1 was isolated from the wastewater of a paper mill. The organism was able to utilize phenol as a sole carbon source. Based on morphological, physiological and biochemical characterizations and 16S rDNA sequence analysis, F5-1 was identified as a species of Klebsiella. The strain F5-1 could degrade phenol with initial concentration of 100 mg/L completely in 7 h and the phenol degradation was found to occur in log phase. At pH 5.0~9.0, the strain F5-1 could efficiently degrade phenol with initial concentration from 100 mg/L to 1 200 mg/L in the presence of 0~80 g/L of NaCl at temperature range from 20℃ to 40 ℃. The highest concentration of phenol that the strain can tolerate was 1 500 mg/L. These results indicated that the strain F5-1 may have potential application in treatment of phenol-containing wastewater with complex environmental conditions.%本研究采用逐量分批驯化的方法,从造纸废水中分离得到一株能够以苯酚为唯一碳源生长的苯酚降解菌株F5-1.经形态观察、生理生化特性鉴定及16S rDNA序列分析,将该菌株鉴定为克雷伯菌(Klebsie-lla sp.).该菌株能够在7 h时完全降解初始浓度为100 mg/L的苯酚,降解苯酚主要发生在生长对数期;在pH 5.0~9.0,NaCl浓度0~80 g/L,温度20~40℃范围内,菌株F5-1均可有效降解初始浓度为100~1 200 mg/L的苯酚;能够耐受的最大苯酚浓度为1 500 mg/L.本研究结果表明,F5-1菌株对处理环境条件复杂的含酚废水具有潜在的应用前景.

  16. Hydrocarbon degradation and plant colonization of selected bacterial strains isolated from the rhizsophere and plant interior of Italian ryegrass and Birdsfoot trefoil

    Science.gov (United States)

    Sohail, Y.; Andria, V.; Reichenauer, T. G.; Sessitsch, A.

    2009-04-01

    Hydrocarbon-degrading strains were isolated from the rhizosphere, root and shoot interior of Italian ryegrass (Lolium multiflorum var. Taurus), Birdsfoot trefoil (Lotus corniculatus var. Leo) grown in a soil contaminated with petroleum oil. Strains were tested regarding their phylogeny and their degradation efficiency. The most efficient strains were tested regarding their suitability to be applied for phytoremediation of diesel oils. Sterilized and non-sterilized agricultural soil, with and with out compost, were spiked with diesel and used for planting Italian ryegrass and birdsfoot trefoil. Four selected strains with high degradation activities, derived from the rhizosphere and plant interior, were selected for individual inoculation. Plants were harvested at flowering stage and plant biomass and hydrocarbon degradation was determined. Furthermore, it was investigated to which extent the inoculant strains were able to survive and colonize plants. Microbial community structures were analysed by 16S rRNA and alkB gene analysis. Results showed efficient colonization by the inoculant strains and improved degradation by the application of compost combined with inoculation as well as on microbial community structures will be presented.

  17. Selection and identification of bacterial strains with methyl-tert-butyl ether, ethyl-tert-butyl ether, and tert-amyl methyl ether degrading capacities.

    Science.gov (United States)

    Purswani, Jessica; Pozo, Clementina; Rodríguez-Díaz, Marina; González-López, Jesús

    2008-11-01

    Nine bacterial strains isolated from two hydrocarbon-contaminated soils were selected because of their capacity for growth in culture media amended with 200 mg/L of one of the following gasoline oxygenates: Methyl-tert-butyl ether (MTBE), ethyl-tert-butyl ether (ETBE), and tert-amyl methyl ether (TAME). These strains were identified by amplification of their 16S rRNA gene, using fDl and rD1 primers, and were tested for their capacity to grow and biotransform these oxygenates in both mineral and cometabolic media. The isolates were classified as Bacillus simplex, Bacillus drentensis, Arthrobacter sp., Acinetobacter calcoaceticus, Acinetobacter sp., Gordonia amicalis (two strains), Nocardioides sp., and Rhodococcus ruber. Arthrobacter sp. (strain MG) and A. calcoaceticus (strain M10) consumed 100 (cometabolic medium) and 82 mg/L (mineral medium) of oxygenate TAME in 21 d, respectively, under aerobic conditions. Rhodococcus ruber (strain E10) was observed to use MTBE and ETBE as the sole carbon and energy source, whereas G. amicalis (strain T3) used TAME as the sole carbon and energy source for growth. All the bacterial strains transformed oxygenates better in the presence of an alternative carbon source (ethanol) with the exception of A. calcoaceticus (strain M10). The capacity of the selected strains to remove MTBE, ETBE, and TAME looks promising for application in bioremediation technologies.

  18. 一株丁草胺降解菌 BTC-3的分离鉴定及降解特性研究%Isolation, Identification and Degradation Characteristics of A Butachlor-degrading Bacterial Strain BTC-3

    Institute of Scientific and Technical Information of China (English)

    马吉平; 陈庆隆; 王洪秀; 姚健; 陈柳萌

    2015-01-01

    A butachlor-degrading bacterial strain named BTC-3 was isolated from a soil sample near the outfall of a pesticide factory, which had produced butachlor for many years.BTC-3 could degrade more than 85%of 100 mg/L butachlor in inorganic salt culture medium with butachlor as sole carbon source within 6 days.Combining the culture, physiological and biochemical character-istics with 16S rRNA sequence analysis, strain BTC-3 was identified as Bacillus sp.The optimal temperature and pH-value for the degradation of butachlor by BTC-3 were 30℃and 7, respectively.When the inoculation amount was less than or equal to 3%, the degrading rate increased with the increase in the inoculation amount.When the initial concentration of butachlor was less than or e-qual to 100 mg/L, the higher the concentration of butachlor, the better the effect of degradation.%从长期生产丁草胺的农药厂排水口土壤中分离得到1株能够降解丁草胺的细菌,将其命名为BTC-3。在以丁草胺为唯一碳源的基础盐培养基中,6 d内可将100 mg/L的丁草胺降解85%以上。经培养特征、生理生化分析和16S rRNA序列分析,将该菌株鉴定为芽孢杆菌属( Bacillus sp.)。菌株BTC-3降解丁草胺的最适温度为30℃,最适pH值为7;当接种量≤3%时,接种量越大,降解率越高;当丁草胺初始浓度≤100 mg/L时,浓度越高,降解效果越好。

  19. Hydrocarbon degradation abilities of psychrotolerant Bacillus strains

    Directory of Open Access Journals (Sweden)

    Fulya Kolsal

    2017-06-01

    Full Text Available Biodegradation requires identification of hydrocarbon degrading microbes and the investigation of psychrotolerant hydrocarbon degrading microbes is essential for successful biodegradation in cold seawater. In the present study, a total of 597 Bacillus isolates were screened to select psychrotolerant strains and 134 isolates were established as psychrotolerant on the basis of their ability to grow at 7 °C. Hydrocarbon degradation capacities of these 134 psychrotolerant isolate were initially investigated on agar medium containing different hydrocarbons (naphthalene, n-hexadecane, mineral oil and 47 positive isolates were grown in broth medium containing hydrocarbons at 20 °C under static culture. Bacterial growth was estimated in terms of viable cell count (cfu ml–1. Isolates showing the best growth in static culture were further grown in presence of crude oil under shaking culture and viable cell count was observed between 8.3 × 105–7.4 × 108 cfu ml–1. In the final step, polycyclic aromatic hydrocarbon (PAH (chrysene and naphthalene degradation yield of two most potent isolates was determined by GC-MS along with the measurement of pH, biomass and emulsification activities. Results showed that isolates Ege B.6.2i and Ege B.1.4Ka have shown 60% and 36% chrysene degradation yield, respectively, while 33% and 55% naphthalene degradation yield, respectively, with emulsification activities ranges between 33–50%. These isolates can be used to remove hydrocarbon contamination from different environments, particularly in cold regions.

  20. Bacterial community structure and predicted alginate metabolic pathway in an alginate-degrading bacterial consortium.

    Science.gov (United States)

    Kita, Akihisa; Miura, Toyokazu; Kawata, Satoshi; Yamaguchi, Takeshi; Okamura, Yoshiko; Aki, Tsunehiro; Matsumura, Yukihiko; Tajima, Takahisa; Kato, Junichi; Nishio, Naomichi; Nakashimada, Yutaka

    2016-03-01

    Methane fermentation is one of the effective approaches for utilization of brown algae; however, this process is limited by the microbial capability to degrade alginate, a main polysaccharide found in these algae. Despite its potential, little is known about anaerobic microbial degradation of alginate. Here we constructed a bacterial consortium able to anaerobically degrade alginate. Taxonomic classification of 16S rRNA gene, based on high-throughput sequencing data, revealed that this consortium included two dominant strains, designated HUA-1 and HUA-2; these strains were related to Clostridiaceae bacterium SK082 (99%) and Dysgonomonas capnocytophagoides (95%), respectively. Alginate lyase activity and metagenomic analyses, based on high-throughput sequencing data, revealed that this bacterial consortium possessed putative genes related to a predicted alginate metabolic pathway. However, HUA-1 and 2 did not grow on agar medium with alginate by using roll-tube method, suggesting the existence of bacterial interactions like symbiosis for anaerobic alginate degradation.

  1. Bacterial Selection from Shrimp Ponds for Degradation of Organic Matters

    OpenAIRE

    Powtongsook, S.; Chanpun, K.; Suntornsuk, W.

    2007-01-01

    Accumulation of ammonia, nitrite and hydrogen sulfide in a shrimp pond is generally caused by incomplete degradation of residual organic matters from overfeeding and from organic wastes released by shrimps. The phenomenon affects shrimp growth and survival rate. The objectives of this investigation were to screen for a bacterial strain able to digest organic residues and to evaluate the changes of residues by bacterial activities under natural conditions. The results from this work showed tha...

  2. Degradation of triclocarban by a triclosan-degrading Sphingomonas sp. strain YL-JM2C.

    Science.gov (United States)

    Mulla, Sikandar I; Hu, Anyi; Wang, Yuwen; Sun, Qian; Huang, Shir-Ly; Wang, Han; Yu, Chang-Ping

    2016-02-01

    Bacterial degradation plays a vital role in determining the environmental fate of micropollutants like triclocarban. The mechanism of triclocarban degradation by pure bacterium is not yet explored. The purpose of this study was to identify metabolic pathway that might be involved in bacterial degradation of triclocarban. Triclosan-degrading Sphingomonas sp. strain YL-JM2C was first found to degrade up to 35% of triclocarban (4 mg L(-1)) within 5 d. Gas chromatography-mass spectrometry detected 3,4-dichloroaniline, 4-chloroaniline and 4-chlorocatechol as the major metabolites of the triclocarban degradation. Furthermore, total organic carbon results confirmed that the intermediates, 3,4-dichloroaniline (4 mg L(-1)) and 4-chloroaniline (4 mg L(-1)) could be degraded up to 77% and 80% by strain YL-JM2C within 5 d.

  3. Degradation and mineralization of 2-chioro-, 3-chloro- and 4-chlorobiphenyl by a newly characterized natural bacterial strain isolated from an electrical transformer fluid-contaminated soil

    Institute of Scientific and Technical Information of China (English)

    Matthew O.Ilori; Gary K.Robinson; Sunday A.Adebusoye

    2008-01-01

    A bacterium classified as Achromobacter xylosoxidans strain IR08 by phenotypic typing coupled with 16S rRNA gene analysis wasisolated from a soil contaminated with electrical transformer fluid for over sixty years using Aroclor 1221 as an enrichment substrate.The substrate utilization profiles revealed that IR08 could grow on all three monochlorobiphenyls (CBs), 2,4'- and 4,4'-dichlorobiphenylas well as 2-chlorobenzoate (2-CBA), 3-CBA, 4-CBA, and 2,3-dichlorobenzoate. Unusually, growth was poorly sustained on biphenyland benzoate. In growth experiments, IR08 degraded all CBs (0.27 mmol/L) in less than 96 h with concomitant stoichiometric release ofinorganic chloride and growth yields were 2-3 times higher than those observed on biphenyl. In contrast to most of the chlorobiphenyl-degrading strains described in the literature, which are reported to form CBA, no metabolite was identified in the culture broth byHPLC analysis. When co-incubated with respective CBs and biphenyl, strain IR08 preferentially utilized the chlorinated analoguesin less than 96 h while it took another 264 h before 90% of the initially supplied biphenyl could be degraded. The promotion of co-metabolic transformation of halogenated substrates by the inclusion of their non-halogenated derivatives may not therefore, result inuniversal benefits.

  4. 添加混合菌剂对石油污染土壤的降解%Degrading of petroleum contaminated soil by injected mixed oil-degradation bacterial strains

    Institute of Scientific and Technical Information of China (English)

    陈丽华; 马金珠; 雒晓芳; 杨琴

    2012-01-01

    Some oil-degradation bacterial strains, designated as A6, A5, D4, Fl and F2, were screened and isolated from oil contaminated soil at Huaqing Oilfield of Gansu Province, China. Different amounts of mixed bacteria were injected into soil polluted by crude oil, and the influences of petroleum degradation rates, including dehydrogenises activity, soil solution electrical conductivity and nitrogen-phosphorus content were studied. The results show that the oil degradation rates with high-efficiency degradation bacteria are higher than the rates without degradation bacteria. After 48 d, with oil contents of 50 g/kg in the contaminated soil, the oil degradation rates with addition of 2%, 4% and 8% bacteria reach 68.01%, 80.42%, 78.47%, respectively, which clearly improves the biodegrading efficiency higher than CK degradation rate (40.34%). The degradation efficiency of the case with 4% mixed bacteria is the highest. In organic fertilizer, nitrogen and phosphorus contents are the main factors affecting oil degradation rate, only appropriate amount of the organic fertilizer could achieve the best degradation efficiency, e.g. the 4% additive amount of organic fertilizer. As revealed by GS-MC, the degrading appears that after being treated with the mixed bacteria, the higher molecular weight n-alkanes are degraded into lower molecular weight n-alkanes, and the n-alkanes in odd-numbered carbon are degraded into n-alkanes in even-numbered carbon. As well as, isoprenoid alkanes appear a significant degradation in crude oil under the action of mixed bacteria after 7 d. The mixed bacteria can promote the transition pentacyclic triterpenes from less stable configuration to stable one.%从甘肃华庆油田污染严重的土壤中富集培养、筛选分离得到A6,A5,D4,F1和F2共5种菌属的降解石油菌,在实验条件下向土壤中添加上述5种菌不同浓度的混合菌剂,并对土壤中的脱氢酶活性、土壤溶液电导率、氮磷的变化对石油污染土壤

  5. Bacterial degradation of monocyclic aromatic amines

    Directory of Open Access Journals (Sweden)

    Pankaj Kumar Arora

    2015-08-01

    Full Text Available Aromatic amines are an important group of industrial chemicals, which are widely used for manufacturing of dyes, pesticides, drugs, pigments, and other industrial products. These compounds have been considered highly toxic to human beings due to their carcinogenic nature. Three groups of aromatic amines have been recognized: monocyclic, polycyclic and heterocyclic aromatic amines. Bacterial degradation of several monocyclic aromatic compounds has been studied in a variety of bacteria, which utilizes monocyclic aromatic amines as their sole source of carbon and energy. Several degradation pathways have been proposed and the related enzymes and genes have also been characterized. Many reviews have been reviewed toxicity of monocyclic aromatic amines; however, there is lack of review on biodegradation of monocyclic aromatic amines. The aim of this review is to summarize bacterial degradation of monocyclic aromatic amines. This review will increase our current understanding of biochemical and molecular basis of bacterial degradation of monocyclic aromatic amines.

  6. Screening,Identification and Degrading Characteristics of A Phenol Degrading Bacterial Strain%一株苯酚降解菌的筛选、鉴定及其降解特性

    Institute of Scientific and Technical Information of China (English)

    刘鸿杰; 何熙璞; 张敏; 梁锦添; 陈加辉; 李俊芳; 陈保善

    2011-01-01

    By gradually increasing the concentration of phenol in the culture medium,a phenol-degrading bacterial strain designated as F5-1 was isolated from the wastewater of a paper mill.The organism was able to utilize phenol as a sole carbon source.Based on morp%本研究采用逐量分批驯化的方法,从造纸废水中分离得到一株能够以苯酚为唯一碳源生长的苯酚降解菌株F5-1。经形态观察、生理生化特性鉴定及16S rDNA序列分析,将该菌株鉴定为克雷伯菌(Klebsiella sp.)。该菌株能够在7h时完全降解初始浓度为100mg/L的苯酚,降解苯酚主要发生在生长对数期;在pH5.0~9.0,NaCl浓度0~80g/L,温度20~40℃范围内,菌株F5-1均可有效降解初始浓度为100~1200mg/L的苯酚;能够耐受的最大苯酚浓度为1500mg/L。本研究结果表明,F5-1菌

  7. Microbial Degradation of Aniline by Bacterial Consortium

    Institute of Scientific and Technical Information of China (English)

    JIAN-LONG WANG; ZE-YU MAO; WEI-ZHONG WU

    2003-01-01

    Objective To investigate the characteristics of microbial degradation of aniline by a stable bacterial consortium. Methods The bacterial consortium was isolated from activated sludge treating chemical wastewater using aniline as the sole source of carbon and nitrogen by enrichment and isolation technique. The biomass was measured as optical density (OD) at 510 nm using a spectrophotometer. Aniline concentrations were determined by spectrophotometer. The intermediates of aniline degradation were identified by GC/MS method. Results The bacterial consortium could grow at a range of aniline concentrations between 50 and 500 mg/L. The optimal pH and temperature for aniline degradation were determined to be 7.0 and 30, respectively. The presence of NH4NO3 as an additional nitrogen source (100-500 mg/L) had no adverse effect on bacterial growth and aniline degradation. The presence of heavy metal ions, such as Co2+, Zn2+, Ni2+, Mn2+ and Cu2+ had an inhibitory effect on aniline degradation. Conclusions The isolated bacterial consortium candegrade aniline up to 500 mg/L effectively and tolerate some heavy metal ions that commonly exist in chemical wastewater. It has a potential to be applied in the practical treatment of aniline-containingwastewater.

  8. 1,4-二氯苯降解菌的分离及其降解特性研究%Study on isolation and characterization of a dichlorobenzene-degrading bacterial strain

    Institute of Scientific and Technical Information of China (English)

    戴青华; 曹晓丹; 孙向武

    2009-01-01

    从某污水处理曝气池的活性污泥中分离出一株能够以1,4-二氯苯为唯一碳源和能源生长的菌株DEB.1,通过形态特征和生理生化试验初步鉴定为黄杆菌属(Flavobacterium sp.).实验结果表明,该菌株最适降解温度为32℃、最适降解pH为7.8,24 h对100 mg/L的1,4-二氯苯的降解率达94.5%.菌株DEB.1的降解谱较广,对5种氯苯类物质具有较高的降解率.并进一步研究了DEB-1的1,4一二氯苯降解酶粗酶液的性质,其最适反应温度和pH分别为30℃和8.5.对处理含氯代芳香化合物的有机废水具有一定的意义.%A bacterial strain named DEB-1 that degraded dichlorobenzene as sole carbon and energy sources was isolated from activated sludge of a wastewater treatment plant. It was identified as Flavobacteriurn sp.according to its morphology and biochemical properties. The results showed that the optimal degradation tempera-ture of DEB-1 was 32 ℃,the optimal degradation pH value was 7.8,the degradation rate reached to 94.5% with-in 24 hours when the concentration of dichlorobenzene was 100 mg/L. The degradation spectrum of strain DEB-1 was broad and it had higher degradation for five chlorobenzenes. Further study on the characterization of strain DEB-1 degrading crude enzyme showed that the optimal reaction temperature and pH was 30 ℃ and 8.5 respec-tively. It could be useful for treating chlorinated-aromatic-containing organic wastewater.

  9. Effect of isolate of ruminal fibrolytic bacterial culture supplementation on fibrolytic bacterial population and survivability of inoculated bacterial strain in lactating Murrah buffaloes

    Directory of Open Access Journals (Sweden)

    Brishketu Kumar

    2013-02-01

    Full Text Available Aim: The present study was conducted to evaluate the effect of bacterial culture supplementation on ruminal fibrolytic bacterial population as well as on survivability of inoculated bacterial strain in lactating Murrah buffaloes kept on high fibre diet. Materials and Methods: Fibrolytic bacterial strains were isolated from rumen liquor of fistulated Murrah buffaloes and live bacterial culture were supplemented orally in treatment group of lactating Murrah buffaloes fed on high fibre diet to see it's effect on ruminal fibrolytic bacterial population as well as to see the effect of survivability of the inoculated bacterial strain at three different time interval in comparison to control group. Results: It has been shown by real time quantification study that supplementation of bacterial culture orally increases the population of major fibre degrading bacteria i.e. Ruminococcus flavefaciens, Ruminococcus albus as well as Fibrobacter succinogenes whereas there was decrease in secondary fibre degrading bacterial population i.e. Butyrivibrio fibrisolvens over the different time periods. However, the inoculated strain of Ruminococcus flavefaciens survived significantly over the period of time, which was shown in stability of increased inoculated bacterial population. Conclusion: The isolates of fibrolytic bacterial strains are found to be useful in increasing the number of major ruminal fibre degrading bacteria in lactating buffaloes and may act as probiotic in large ruminants on fibre-based diets. [Vet World 2013; 6(1.000: 14-17

  10. 联苯菊酯降解菌的筛选、鉴定及降解特性研究%Isolation, Identification and Biodegradation Characteristics of a Bacterial Strain able to Degrade Bifenthrin

    Institute of Scientific and Technical Information of China (English)

    刘婷婷; 董昆明; 缪莉; 周晓见; 靳翠丽; 姜薇; 封克

    2012-01-01

    Bifenthrin(BF) is a broad-spectrum and highly efficient synthetic insecticide. However, the difficulty of its natural degradation makes it widely remain in the environment, which causes many critical environmental problems. Microbial biodegradation of pesticide residues, especially bacterial biodegradation, is the main way in repair of such sort of environment pollution. Although there have been some reports on the pyrethroid insecticide degradation bacteria, the degradation effect and stability of those bacteria still need to be explored. Therefore, the screen for efficient BF degrading bacteria has great research significance. In this study, a BF degrading bacterium designated as S8 was isolated, purified and sorted from the surface soil near to the Yangzhou Pesticide Plant The bacterial strain S8 was identified as Acinetobacter cakoacelkus, according to its morphological, physiological and biochemical characterization, as well as the sequence analysis of its I6S rDNA. The BF degradation reached equilibrium at 72 h and the degradation rate was 56.4%( initial concentration of 100 mg·L-1) with half lives of 2.53 d under the conditions of pH7.0 and 30 ℃. The optimal conditions for BF degradation were at pH6.0~8.0, 30-35 ℃ and with 5% inoculation. The results indicated that the BF-degrading strain S8 had great application potential for the future bioremediation of environmental contamination by BF.%联苯菊酯是一种广谱高效杀虫剂,大规模的应用使其广泛残留在环境中,因此筛选联苯菊酯的高效降解菌具有重要意义.从扬州农药厂附近的地表土壤取样,利用富集驯化培养分离得到一株编号为S8的降解细菌,经表形特征、生理生化特性和16SrDNA序列分析其为醋酸钙不动杆菌(Acinetobacter calcoacetic us),该菌株在pH7.0和30℃的条件下,对100 mg·L1联苯菊酯的3d降解率达56.4%,半衰期为60.7 h.其最适生长条件为:pH6.0-8.0,温度30~35℃,接种量5%.研究结果可

  11. Bacteriocins and novel bacterial strains.

    Science.gov (United States)

    Poultry is thought to be a significant source of Campylobacter in human disease. We evaluated anti-Campylobacter activity among 365 Bacillus and Paenibacillus isolates from poultry. One novel antagonistic Bacillus circulans and three Paenibacillus polymyxa strains were identified and further studi...

  12. 一株新的多菌灵高效降解菌的筛选与降解特性分析%Identification and Characterization of a Newly Isolated Carbendazim-degrading Bacterial Strain MBC

    Institute of Scientific and Technical Information of China (English)

    王呈玉; 李明石; 曲迪; 李成龙; 崔俊涛; 胡耀辉; 王玉军

    2012-01-01

    A novel bacterial strain, which can effectively use carbendazim as sole carbon and energy source, was isolated from long-term carbendazim administered soil by enrichment screening. Based on the analysis of physiological and biochemical characteristics, 16S rDNA gene sequence homology and phylogenetic tree, the isolate was identified. Its degradation characteristics and degradation capability of the lysate were tested by HPLC. The new bacterial strain was identified as Raoultella sp. and named MBC. Results showed that this strain could utilize carbendazim as sole carbon source for growth, and could degrade 100% of carbendazim after 72 h shaking culture at 200 r·min-1, 25 °C and pH 7.0. Its degradation rate was increased by adding exogenous carbon and nitrogen source into the medium at the later stage of culture, and the degradation of adding exogenous nitrogen source was more effective than that of carbon source. The lysate had a degrading activity of carbendazim, and the catabolic enzymes were the induced enzyme. These results provided a rationale and a material for bio-remediation of long-term carbendazim-contaminated soil.%从长期施用多菌灵农药的土壤中,通过富集筛选,获得1株新的多菌灵高效降解菌株.通过生理生化实验和16S rDNA序列同源性分析鉴定该菌株,应用高效液相色谱法对纯培养条件下菌株的降解特性和粗酶提取液的降解性能进行了分析.结果表明,筛选所获得的菌株与Raoultella菌属的亲缘关系最近,将其命名为Raoultella sp.MBC,该菌株能在以多菌灵为唯一碳源的无机盐培养基中生长;25℃、pH7.0、200 r·min-1的最适生长条件下避光振荡培养72 h,多菌灵的降解率达到100%;在最适培养条件下外加氮源和碳源在培养后期均可以提高多菌灵的降解率,外加氮源对多菌灵的降解效果优于外加碳源;该菌体的粗酶提取液具有降解多菌灵活性,且多菌灵降解酶为诱导酶.研究结果为

  13. Bacterial Selection from Shrimp Ponds for Degradation of Organic Matters

    Directory of Open Access Journals (Sweden)

    Powtongsook, S.

    2007-01-01

    Full Text Available Accumulation of ammonia, nitrite and hydrogen sulfide in a shrimp pond is generally caused by incomplete degradation of residual organic matters from overfeeding and from organic wastes released by shrimps. The phenomenon affects shrimp growth and survival rate. The objectives of this investigation were to screen for a bacterial strain able to digest organic residues and to evaluate the changes of residues by bacterial activities under natural conditions. The results from this work showed that the isolated strain, Bacillus cereus S1, had the highest protease activity (57.1 U/ml with the presence of glucoamylase and lipase activities (4.5 and 0.13 U/ml, respectively. Under an aseptic condition in 1-L flasks containing seawater with 0.1% shrimp feed, B. cereus S1 degraded organic matters and significantly reduced chemical oxygen demand (COD (70.8%. An amount of ammonia-nitrogen was increased during the first 5 days of incubation due to the degradation of organic compounds in shrimp feed. However, it declined afterward with nitrate-nitrogen increase and unchanged nitrite nitrogen content. Under natural conditions in 10-L glass jars containing seawater with 0.05% shrimp feed and 0.05% sediment, B. cereus S1 and a commercial bacterial product (Inpicin-G could reduce COD (4.5% and 15.8%, respectively and biochemical oxygen demand (BOD (35.1 and 11.4%, respectively. However, similar changes of ammonia-nitrogen, nitrate-nitrogen and nitrite-nitrogen contents in water samples were observed. The results indicate that this selected bacterium could reduce organic compound accumulations on a laboratory scale. In addition, the strain did not produce any enterotoxins compared to a toxin standard. Therefore, the bacterium, Bacillus cereus S1, could be applied to decrease organic matters accumulated in shrimp pond without any harm to shrimps or consumers.

  14. Mycotoxin-degradation profile of Rhodococcus strains.

    Science.gov (United States)

    Cserháti, M; Kriszt, B; Krifaton, Cs; Szoboszlay, S; Háhn, J; Tóth, Sz; Nagy, I; Kukolya, J

    2013-08-16

    Mycotoxins are secondary fungal metabolites that may have mutagenic, carcinogenic, cytotoxic and endocrine disrupting effects. These substances frequently contaminate agricultural commodities despite efforts to prevent them, so successful detoxification tools are needed. The application of microorganisms to biodegrade mycotoxins is a novel strategy that shows potential for application in food and feed processing. In this study we investigated the mycotoxin degradation ability of thirty-two Rhodococcus strains on economically important mycotoxins: aflatoxin B1, zearalenone, fumonisin B1, T2 toxin and ochratoxin A, and monitored the safety of aflatoxin B1 and zearalenone degradation processes and degradation products using previously developed toxicity profiling methods. Moreover, experiments were performed to analyse multi-mycotoxin-degrading ability of the best toxin degrader/detoxifier strains on aflatoxin B1, zearalenone and T2 toxin mixtures. This enabled the safest and the most effective Rhodococcus strains to be selected, even for multi-mycotoxin degradation. We concluded that several Rhodococcus species are effective in the degradation of aromatic mycotoxins and their application in mycotoxin biodetoxification processes is a promising field of biotechnology.

  15. Tannic acid degradation by Klebsiella strains isolated from goat feces

    Directory of Open Access Journals (Sweden)

    Arezoo Tahmourespour

    2016-03-01

    Full Text Available Background and Objectives: Tannins are toxic polyphenols that either bind and precipitate or condense proteins. The high tannin content of some plants is the preliminary limitation of using them as a ruminant feed. So, the aim of this study was the isolation and characterization of tannic acid degrading bacterial strains from goat feces before and after feeding on Pis- tachio-Soft Hulls as tannin rich diet (TRD.Materials and Methods: Bacterial strains capable of utilizing tannic acid as sole carbon and energy source were isolated and characterized from goat feces before and after feeding on TRD. Tannase activity, maximum tolerable concentration and biodegradation potential were assessed.Results: Four tannase positive isolates were identified as Klebsiella pneumoniae. Isolated strains showed the maximum tolerable concentration of 64g/L of tannin. The tannic acid degradation percentage at a concentration of 15.0 g/L reached a maximum of 68% after 24 h incubation, and more than 98% after 72 h incubation. The pH of the medium also decreased along with tannic acid utilization.Conclusions: It is obvious that TRD induced adaptive responses. Thus, while the bacteria were able to degrade and detoxify the tannic acids, they had to adapt in the presence of high concentrations of tannic acid. So, these isolates have an amazing potential for application in bioremediation, waste water treatment, also reduction of tannins antinutritional effects in animal feeds.Keywords: Biodegradation; Goat feces; Klebsiella strains; Tannic acid

  16. Bacterial degradation and corrosion of naphtha in transporting pipeline.

    Science.gov (United States)

    Rajasekar, A; Ponmariappan, S; Maruthamuthu, S; Palaniswamy, N

    2007-11-01

    Five naphtha hydrocarbon-degrading bacteria including representative strains of the two classified species (Serratia marcescensAR1, Bacillus pumilusAR2, Bacillus carboniphilus AR3, Bacillus megaterium AR4, and Bacillus cereus AR5) were identified by 16S rDNA gene sequence in a naphtha-transporting pipeline. The naphtha-degrading strains were able to be involved in the corrosion process of API 5LX steel and also utilized the naphtha as the sole carbon source. The biodegradation of naphtha by the bacterial isolates was characterized by gas chromatography-mass spectrometry. Weight-loss measurement on the corrosion of API 5LX steel in the presence/absence of consortia grown in naphtha-water aqueous media was performed. The scanning electron microscope observation showed that the consortia were able to attack the steel API 5LX surface, creating localized corrosion (pit). The biodegradation of naphtha by the strains AR1, AR2, AR3, AR4, and AR5 showed biodegradation efficiency of about 76.21, 67.20, 68.78, 68.78, and 68.15, respectively. The role of degradation on corrosion has been discussed. This basic study will be useful for the development of new approaches for the detection, monitoring, and control of microbial corrosion in a petroleum product pipeline.

  17. Degradation of phenanthrene-analogue azaarenes by Mycobacterium gilvum strain LB307T under aerobic conditions.

    Science.gov (United States)

    Willumsen, P A; Nielsen, J K; Karlson, U

    2001-08-01

    A polycyclic aromatic hydrocarbon degrading Mycobacterium gilvum, strain LB307T, was able to degrade the azaarenes 5,6-benzoquinoline, 7,8-benzoquinoline, and phenanthridine (nitrogen-containing heterocyclic aromatic hydrocarbons) under aerobic conditions. The strain was able to use 5,6-benzoquinoline as sole sources of carbon, nitrogen, and energy. However, inhibition of degradation and growth was observed with increasing substrate concentration. During degradation, metabolites built up transiently. One of the metabolites detected during 5,6-benzoquinoline degradation is suggested to be 2-oxo-5,6-benzoquinoline. This is the first report on bacterial degradation of phenanthrene-analogue azaarenes.

  18. Aerobic cyanide degradation by bacterial isolates from cassava factory wastewater

    Directory of Open Access Journals (Sweden)

    Sujatha Kandasamy

    2015-09-01

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

  19. Aerobic cyanide degradation by bacterial isolates from cassava factory wastewater.

    Science.gov (United States)

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

    2015-01-01

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

  20. Aerobic granulation of pure bacterial strain Bacillus thuringiensis

    Institute of Scientific and Technical Information of China (English)

    Sunil S ADAV; Duu-Jong LEE

    2008-01-01

    The objective of this study is to cultivate aer-obic granules by pure bacterial strain, Bacillus thuringien-sis, in a sequencing batch reactor. Stable granules sized 2.0-2.2 mm were formed in the reactor after a five-week cultivation. These granules exhibited excellent settling attributes, and degraded phenol at rates of 1.49 and concentration, respectively. Confocal laser scanning microscopic test results show that Bacillus thuringiensis was distributed over the initial small aggregates, and the outer edge of the granule was away from the core regime in the following stage.

  1. Degradation Characteristics and Community Structure of a Hydrocarbon Degrading Bacterial Consortium

    Institute of Scientific and Technical Information of China (English)

    Li Zheng; Gu Guizhou; Zhao Chaocheng; Zhao Dongfeng

    2015-01-01

    A hydrocarbon degrading bacterial consortium KO5-2 was isolated from oil-contaminated soil of Karamay in Xinjiang, China, which could remove 56.9%of 10 g/L total petroleum hydrocarbons (TPH) at 30℃after 7 days of incu-bation, and could also remove 100%of lfuorene, 98.93%of phenanthrene and 65.73%of pyrene within 3, 7 and 9 days, respectively. Twelve strains from six different genera were isolated from KO5-2 and only eight ones were able to utilize the TPH. The denaturing gradient gel electrophoresis (DGGE) was used to investigate the microbial community shifts in ifve different carbon sources (including TPH, saturated hydrocarbons, lfuorene, phenanthrene and pyrene). The test results indi-cated that the community compositions of KO5-2 in carbon sources of TPH and saturated hydrocarbons, respectively, were roughly the same, while they were distinctive in the three different carbon sources of PAHs. Rhodococcus sp. and Pseudo-monas sp. could survive in the ifve kinds of carbon sources. Bacillus sp., Sphingomonas sp. and Ochrobactrum sp. likely played key roles in the degradation of saturated hydrocarbons, PAHs and phenanthrene, respectively. This study showed that speciifc bacterial phylotypes were associated with different contaminants and complex interactions between bacterial spe-cies, and the medium conditions inlfuenced the biodegradation capacity of the microbial communities involved in bioreme-diation processes.

  2. The effects of temperature and pH bacterial degradation of latex ...

    African Journals Online (AJOL)

    The effects of temperature and pH bacterial degradation of latex paint in ... degradation of latex paint under humid condition by bacterial isolates was studied. ... can be preserved from bacterial contamination, deterioration and degradation by ...

  3. Draft Genome Sequence of a Chitinophaga Strain Isolated from a Lignocellulose Biomass-Degrading Consortium

    Science.gov (United States)

    Kishi, Luciano T.; Lopes, Erica M.; Fernandes, Camila C.; Fernandes, Gabriela C.; Sacco, Lais P.; Carareto Alves, Lucia M.

    2017-01-01

    ABSTRACT Chitinophaga comprises microorganisms capable of degrading plant-derived carbohydrates, serving as a source of new tools for the characterization and degradation of plant biomass. Here, we report the draft genome assembly of a Chitinophaga strain with 8.2 Mbp and 7,173 open reading frames (ORFs), isolated from a bacterial consortium that is able to degrade lignocellulose. PMID:28104646

  4. Isolation, identification and corn stalk degradation characteristics of cellulose-degrading bacterial strain NH11%一株纤维素降解菌的分离、鉴定及对玉米秸秆的降解特性

    Institute of Scientific and Technical Information of China (English)

    吴文韬; 鞠美庭; 刘金鹏; 刘博群; 佟树敏

    2013-01-01

    [Objective] This study is aimed to obtain effective cellulose-degrading bacterial strains and study the characteristics of cellulase production and degradation characteristics used NH3-H2O pretreated corn stalk as substrate, and explore mechanism of cellulose enzyme so as to improve the resource utilization rate of agricultural solid wastes. [Methods] LB medium was used to obtain eleven bacterial strains (NH1-11) from earthworm farm. CMC-Na was used in preliminary medium and congo red staining method to screening strains. Influence of pretreatment to cellulose production ability of NH11 and degradation rate of substrates was studied. Morphological characteristics of NH11 was observed by electron microscope and identified by 16S rRNA and Biolog method. [Results] Bacterial strain NH11 was isolated and identified as Bacillus subtilis. The maximum degradation rate of untreated and pretreated corn stalk was 14.24% and 24.73% when culture temperature was 30 ℃ after five days. CMC cellulose activity of NH11 reached to 153.84 U/mL and FPA cellulose activity to 197.24 U/mL in treatment group, 11.45% and 10.59% higher than untreated group. [Conclusion] NH11 has a high cellulase productivity, and NH3·H2O pretreatment could enhance the degradation rate of corn stalk. NH11 has a high value in straw compost, mushroom culture medium and ruminant feed production.%[目的]获得高产纤维素酶细菌菌株,探讨以氨化预处理玉米秸秆为底物时的纤维素酶产酶特性及底物降解特性,探讨纤维素酶作用机理,提高玉米秸秆利用率.[方法]用LB培养基分离并纯化菌株,羧甲基纤维素钠培养基培养、刚果红染色进行初步筛选.考察氨化预处理对底物降解率、产酶能力的影响.通过形态特征观察及16S rRNA、Biolog鉴定菌株.[结果]分离到一株高效纤维素降解菌NH11,经鉴定为枯草芽孢杆菌(Bacillus subtilis). 30℃、发酵5d时,预处理前后玉米秸秆降解率分别为14.24%和24.73

  5. Isolation, Identification and Biodegradation Characteristics of a 4-tert-Octylphenol Degradable Bacterial Strain%环境激素对叔辛基酚降解菌的筛选、鉴定及降解特性

    Institute of Scientific and Technical Information of China (English)

    刘杨; 董昆明; 缪莉; 周晓见; 靳翠丽; 封克

    2012-01-01

    A bacterial strain labeled as TW30, which can use4-t-0P (4-tert-0ctylphend) as the sole carbon source, was isolated from the activated sludge from the secondary sedimentation tank of the Yangzhou Tangwang Wastewater Treatment Plant. The strain TW30 was identified preliminarily according to the analysis of its 16S rRNA gene sequence as Acinetobacter sp. The results showed that the optimal conditions for 4-t-OP biodegradation in the shaking flasks were 40 X, and pH 6. 0. Under these conditions, 99. 03% of the initial 5 mg/L p(4-t-OP) was degraded after 5 d culturing. The biodegradation reaction fitted well with the first-order kinetic model, with a degradation constant (k) of 0. 875 d-1 and half-life (t1n) of 0.8 d. The degradation rate of 4-t-OP was enhanced by the increase of temperature and addition of Ca2+ and Mn20 . The rate was deceased by the increase of initial concentration of p(4-t-OP) in the range of 5 to 25 mg/L, and by the addition of phosphates, NH4+ , Mg2+ , Fe2+ , Na+ , Zn2+ , Cu2+ , NaAc and glucose.%为了研究环境激素4-t-OP(对叔辛基酚)的生物降解,从扬州市汤汪生活污水处理厂二沉池污泥中筛选得到1株能以4-t-OP为唯一碳源进行生长的降解菌株,标示为TW30,16S rRNA测试其为不动杆菌属(Acinetobacter sp.),通过摇瓶试验测试其降解活性.结果表明:在40℃、初始pH为6.0、p(4-t-OP)为5 mg/L的无机盐培养基中,5d后降解率可达99.03%;降解过程满足一级反应模型,降解速率常数(k)为0.875 d-1,半衰期(t1Ω)为0.8d.这说明TW30是一株高效的4-t-OP降解菌.此外,培养温度的升高和额外Ca2+、Mn2+的加入可以提高TW30降解4-t-OP的效率,而在5~25 mg/L范围内提高初始p(4-t-OP)以及额外加入磷酸盐、NH4+、Mg2+、Fe2、Na+、Zn2+、Cu2+等无机盐和葡萄糖、CH3COO-等碳源则会降低降解率.

  6. Isolation,identification,degradation characteristics and pathway of a pyrethroid-degrading bacterial strain%一株拟除虫菊酯农药降解菌的分离鉴定及其降解特性与途径

    Institute of Scientific and Technical Information of China (English)

    陈少华; 罗建军; 胡美英; 赖开平; 耿鹏; 肖盈

    2011-01-01

    A bacterial strain named P-01 was newly isolated by enrichment culture from the activated sludge in the wastewater of a pyrethroid-manufacturer in Zhongshan.Based on the morphology,physio-biochemical characteristics,and 16S rDNA sequence analysis,strain P-01 was temporarily identified as Achromobacter sp.P-01.Response surface methodology(RSM) was used to optimize degradation conditions.The optimal conditions for biodegradation were obtained as follows:31.4℃,pH 7.6 and inoculum biomass 0.4 g · L-1.Under the optimal degradation conditions,strain P-01 could effectively degrade deltamethrin,fenvalerate,beta-cypermethrin,beta-cyfluthrin and cyhalothrin with degradation rates of 98.9%,92.2%,91.0%,85.1% and 77.3%,respectively,within 7 days of incubation.Strain P-01 not only could utilize deltamethrin as the sole carbon source and energy for growth in mineral salt medium(MSM),but also could tolerate and efficiently degrade high concentrations of deltamethrin(100~500 mg · L-1).Furthermore,the degradation reaction followed first-order kinetics and half lives(T1/2) were 1.3,1.8,2.0,2.5 and 3.0 d,respectively.Studies on the degradation pathway showed that deltamethrin was degraded by hydrolysis of the carboxylester linkage to yield alpha-hydroxy-3-phenoxy-benzeneacetonitrile and 3-phenoxy benzaldehyde,and then the intermediates were further degraded by oxygenolysis to form 2-hydroxy-4-methoxy benzophenone and 1,2-benzenedicarboxylic acid,mono ester,finally resulting in complete detoxification.%采用富集培养法,从拟除虫菊酯农药厂废水排放口的活性污泥中分离到1株菊酯农药高效降解菌P-01.经形态、生理生化特征及16S rDNA序列分析,初步鉴定其为无色杆菌属(Achromobacter sp.).响应曲面法优化菌株P-01的降解条件,其降解最优条件为31.4℃、初始pH7.6和接种量0.4g·L-1,在此条件下,该菌株培养7d对50mg·L-1溴氰菊酯、氰戊菊酯、高效氯氰菊酯、高效氟

  7. Biodegradation of crude oil by individual bacterial strains and a mixed bacterial consortium

    Directory of Open Access Journals (Sweden)

    Santina Santisi

    2015-06-01

    Full Text Available Three bacterial isolates identified as Alcanivorax borkumensis SK2, Rhodococcus erythropolis HS4 and Pseudomonas stutzeri SDM, based on 16S rRNA gene sequences, were isolated from crude oil enrichments of natural seawater. Single strains and four bacterial consortia designed by mixing the single bacterial cultures respectively in the following ratios: (Alcanivorax: Pseudomonas, 1:1, (Alcanivorax: Rhodococcus, 1:1, (Pseudomonas: Rhodococcus, 1:1, and (Alcanivorax: Pseudomonas: Rhodococcus, 1:1:1, were analyzed in order to evaluate their oil degrading capability. All experiments were carried out in microcosms systems containing seawater (with and without addition of inorganic nutrients and crude oil (unique carbon source. Measures of total and live bacterial abundance, Card-FISH and quali-, quantitative analysis of hydrocarbons (GC-FID were carried out in order to elucidate the co-operative action of mixed microbial populations in the process of biodegradation of crude oil. All data obtained confirmed the fundamental role of bacteria belonging to Alcanivorax genus in the degradation of linear hydrocarbons in oil polluted environments.

  8. Application of an Efficient Formaldehyde-degrading Bacterial Strain in Treatment of Accidently Polluted Water%高效甲醛降解菌处理突发污染事故研究

    Institute of Scientific and Technical Information of China (English)

    肖波; 谭周亮; 刘庆华; 周后珍; 李旭东

    2011-01-01

    A bacterial strain BZ-001H, capable of efficiently degrading formaldehyde, was isolated and identified as Bacillus cereus.The optimal conditions for formaldehyde degradation by BZ-001H included 30 ℃, pH 7, 8 000 mg L-1 formaldehyde and 0.3‰ inoculation.Interestingly, this degradation process seemed to be more pH-sensitive for higher substrate concentrations than for lower ones.The wastewaters containing 2 035.67 mg L-1, 4 155.63 mg L-1, 8 099.27 mg L-1 formaldehyde were degraded rapidly by 99% within only 2.5 h, 6 h and 14 h, respectively, with BZ-001H in regular biological system.It took only 8 h for the emergency treatment of the wastewater containing 4 073.65 mg L-1 formaldehyde under simulating engineering conditions to meet the formaldehyde discharge standard, with BZ-001H in regular SBR system.The effect of the emergency treatment on the treatment systems suggested that after the treatment of 4 073.65 mg L-1 formaldehyde-wastewater, the COD and NH4-N met the discharge standard by the emergency SBR treatment system after 2 and 6 cycles, respectively; but the NH4-N did not meet the discharge standard by the regular SBR system after 10 cycles, with the removal efficiency was only 18.81%.Fig 6, Ref 17%通过选择培养,选育到1株能快速降解高浓度甲醛的菌株BZ-001H,经鉴定为Bacillus cereus,其最适降解条件是30℃和pH 7.0,最适浓度为8 000 mg L-1,最佳接种量为0.3‰,甲醛浓度越高时对pH的变化越敏感.用BZ-001H作为功能菌株对活性污泥系统强化后应急处理含2 035.67 mg L-1、4 155.63 mg L-1、8 099.27 mg L-1浓度甲醛的模拟废液,2.5h、6 h、14 h后去除率都能达到99%以上.模拟甲醛突发污染事故场景与应用条件,用BZ-001H强化常规SBR工艺应急处理4 073.65 mg L-1甲醛废液,经过8 h降解,可使出水甲醛达到《污水综合排放标准》(GB 8978-1996)一级标准.同时,考察了应急处理过程对应急系统和常规系统的影响,结果表明,应急处

  9. Thiamethoxam degradation by Pseudomonas and Bacillus strains isolated from agricultural soils.

    Science.gov (United States)

    Rana, Shivnam; Jindal, Vikas; Mandal, Kousik; Kaur, Gurpreet; Gupta, V K

    2015-05-01

    Twelve bacterial species were evaluated to know the degradation pattern of thiamethoxam in liquid medium. All the bacterial species could actively degrade phorate in a mineral salt medium containing phorate (50 μg ml(-1)) as sole carbon source. As these species have ability to degrade, we used these for the degradation of thiamethoxam--a neonicoitinoids. Screening of 12 active phorate-metabolizing bacterial species resulted in selection of Bacillus aeromonas strain IMBL 4.1 and Pseudomonas putida strain IMBL 5.2 causing 45.28 and 38.23 % thiamethoxam (50 μg ml(-1)) reduction, respectively, in 15 days as potential thiamethoxam degrading species. These two bacterial species grew optimally at 37 °C under shake culture conditions in MSMT medium raised with initial pH of 6.0-6.5 and use of these optimum cultural conditions resulted in improved thiamethoxam degradation by these bacterial species. These species caused maximum thiamethoxam degradation only in the presence of thiamethoxam as sole source of carbon and energy and the same was reduced in the presence of easily metabolize able carbon (C₀ and C₁) and nitrogen ((N₀, N₁ and N₂) sources. This could be attributed to involvement of repressible metabolic pathways, reactions of which are inhibited by the presence of easily available nutrients for growth. Besides above, qualitative analysis of thiamethoxam residues by gas liquid chromatography revealed complete metabolization of thiamethoxam without detectable accumulation of any known thiamethoxam metabolites.

  10. Zearalenone degradation by two Pseudomonas strains from soil.

    Science.gov (United States)

    Tan, Hui; Hu, Yanchun; He, Jie; Wu, Lei; Liao, Fei; Luo, Biao; He, Yajun; Zuo, Zhicai; Ren, Zhihua; Zhong, Zhijun; Peng, Guangneng; Deng, Junliang

    2014-11-01

    This study describes the screening of soil bacteria for their capability to degrade zearalenone (ZEN), employing an enrichment technique in which ZEN is used as the sole carbon source. Two isolates that were able to degrade ZEN belonged to the genus Pseudomonas according to biochemical characterization and 16S rRNA gene sequence and were named as Pseudomonas alcaliphila TH-C1 and Pseudomonas plecoglossicida TH-L1, respectively. The results showed that the degradation rates of P. alcaliphila TH-C1 and P. plecoglossicida TH-L1 for ZEN (2 μg/ml) were 68 ± 0.85 % and 57 ± 0.73%, when incubated for 72 h at 30 °C in a rotary shaker (160 rpm) and detected by high-performance liquid chromatograms (HPLC). These results suggest that the two Pseudomonas strains are new bacterial resource for degrading ZEN and can provide a new approach for the detoxification of ZEN.

  11. Biodegradation of organochlorine pesticide endosulfan by bacterial strain Alcaligenes faecalis JBW4.

    Science.gov (United States)

    Kong, Lingfen; Zhu, Shaoyuan; Zhu, Lusheng; Xie, Hui; Su, Kunchang; Yan, Tongxiang; Wang, Jun; Wang, Jinhua; Wang, Fenghua; Sun, Fengxia

    2013-11-01

    The recently discovered endosulfan-degrading bacterial strain Alcaligenesfaecalis JBW4 was isolated from activated sludge. This strain is able to use endosulfan as a carbon and energy source. The optimal conditions for the growth of strain JBW4 and for biodegradation by this strain were identified, and the metabolic products of endosulfan degradation were studied in detail. The maximum level of endosulfan biodegradation by strain JBW4 was obtained using broth at an initial pH of 7.0, an incubation temperature of 40 degreeC and an endosulfan concentration of 100 mg/L. The concentration of endosulfan was determined by gas chromatography. Strain JBW4 was able to degrade 87.5% of alpha-endosulfan and 83.9% of beta-endosulfan within 5 days. These degradation rates are much higher than the previously reported bacterial strains. Endosulfan diol and endosulfan lactone were the major metabolites detected by gas chromatography-mass spectrometry; endosulfan sulfate, which is a persistent and toxic metabolite, was not detected. These results suggested that A. faecalis JBW4 degrades endosulfan via a non-oxidative pathway. The biodegradation of endosulfan by A. faecalis is reported for the first time. Additionally, the present study indicates that strain JBW4 may have potential for the biodegradation of endosulfan residues.

  12. Studies on hydrocarbon degradation by the bacterial isolate ...

    African Journals Online (AJOL)

    Studies on hydrocarbon degradation by the bacterial isolate ... Journal Home > Vol 4, No 3 (2015) > ... The degradation of 2 % heavy crude oil and other PAHs from the isolate PM-1 was assessed ... Algeria (5); Benin (2); Botswana (3); Burkina Faso (3); Cameroon (8); Congo, Republic (1); Côte d'Ivoire (4); Egypt, Arab Rep.

  13. Isolation and Degrading Characteristics of a Phenol-degrading Bacterial Strain with High Efficiency%苯酚高效降解菌的筛选和降解特性研究

    Institute of Scientific and Technical Information of China (English)

    李江; 白涛; 饶军; 宋钞穷

    2007-01-01

    从东华理工学院北区原化学系排污口土壤中筛选到一株高效的苯酚降解细菌PS1.该菌为球菌,革兰氏染色阴性,能以苯酚为唯一碳源和能源生长.经16S rRNA基因部分序列分析PS1为Raoultella属菌株(Raoultella sp.strain PS1),其最高苯酚耐受和降解浓度在3500mg/L以上,当苯酚浓度为500mg/L和1000mg/L时,22h和32h可完全降解,在1500mg/L~3000mg/L时,32h~50h可完全降解,2500mg/L时降解速率最快,达78.1mg/h.通过正交试验得出该菌最适生长条件为25℃、pH6.5、葡萄糖500mg/L;最佳苯酚降解条件为20℃、pH7.0、葡萄糖500mg/L.

  14. Decolorization of the textile dyes by newly isolated bacterial strains.

    Science.gov (United States)

    Chen, Kuo-Cheng; Wu, Jane-Yii; Liou, Dar-Jen; Hwang, Sz-Chwun John

    2003-02-27

    Six bacterial strains with the capability of degrading textile dyes were isolated from sludge samples and mud lakes. Aeromonas hydrophila was selected and identified because it exhibited the greatest color removal from various dyes. Although A. hydrophila displayed good growth in aerobic or agitation culture (AGI culture), color removal was the best in anoxic or anaerobic culture (ANA culture). For color removal, the most suitable pH and temperature were pH 5.5-10.0 and 20-35 degrees C under anoxic culture (ANO culture). More than 90% of RED RBN was reduced in color within 8 days at a dye concentration of 3,000 mg l(-1). This strain could also decolorize the media containing a mixture of dyes within 2 days of incubation. Nitrogen sources such as yeast extract or peptone could enhance strongly the decolorization efficiency. In contrast to a nitrogen source, glucose inhibited decolorization activity because the consumed glucose was converted to organic acids that might decrease the pH of the culture medium, thus inhibiting the cell growth and decolorization activity. Decolorization appeared to proceed primarily by biological degradation.

  15. Bacterial enzymes involved in lignin degradation

    NARCIS (Netherlands)

    de Gonzalo, Gonzalo; Colpa, Dana I; Habib, Mohamed H M; Fraaije, Marco W

    2016-01-01

    Lignin forms a large part of plant biomass. It is a highly heterogeneous polymer of 4-hydroxyphenylpropanoid units and is embedded within polysaccharide polymers forming lignocellulose. Lignin provides strength and rigidity to plants and is rather resilient towards degradation. To improve the (bio)p

  16. Bacterial enzymes involved in lignin degradation

    NARCIS (Netherlands)

    de Gonzalo, Gonzalo; Colpa, Dana I; Habib, Mohamed H M; Fraaije, Marco W

    2016-01-01

    Lignin forms a large part of plant biomass. It is a highly heterogeneous polymer of 4-hydroxyphenylpropanoid units and is embedded within polysaccharide polymers forming lignocellulose. Lignin provides strength and rigidity to plants and is rather resilient towards degradation. To improve the

  17. Bacterial degradation of m-nitrobenzoic acid.

    OpenAIRE

    Nadeau, L J; Spain, J C

    1995-01-01

    Pseudomonas sp. strain JS51 grows on m-nitrobenzoate (m-NBA) with stoichiometric release of nitrite. m-NBA-grown cells oxidized m-NBA and protocatechuate but not 3-hydroxybenzoate, 4-hydroxy-3-nitrobenzoate, 4-nitrocatechol, and 1,2,4-benzenetriol. Protocatechuate accumulated transiently when succinate-grown cells were transferred to media containing m-NBA. Respirometric experiments indicated that the conversion of m-NBA to protocatechuate required 1 mol of oxygen per mol of substrate. Conver...

  18. A role of Bradyrhizobium elkanii and closely related strains in the degradation of methoxychlor in soil and surface water environments.

    Science.gov (United States)

    Satsuma, Koji; Masuda, Minoru; Sato, Kiyoshi

    2013-01-01

    We have reported that a leguminous bacterial strain, Bradyrhizobium sp. strain 17-4, isolated from river sediment, phylogenetically very close to Bradyrhizobium elkanii, degraded methoxychlor through O-demethylation and oxidative dechlorination. In the present investigation, we found that B. elkanii (USDA94), a standard species deposited in the Culture Collection, degraded methoxychlor. Furthermore, Bradyrhizobium sp. strain 4-1, also very close to B. elkanii, isolated from Japanese paddy field soil, degraded methoxychlor. These B. elkanii and closely related strains degraded methoxychlor through almost identical metabolic pathways, and cleaved the phenyl ring and mineralized. In contrast, another representative Bradyrhizobium species, B. japonicum (USDA110), did not degrade methoxychlor at all. Based on these findings, B. elkanii and closely related strains are likely to play an important role not only in providing the readily biodegradable substrates but also in completely degrading (mineralizing) methoxychlor by themselves in the soil and surface water environment.

  19. 2株纤维素降解细菌处理白酒丢糟的应用特性%Application Characteristics of Two Cellulose-degradation Bacterial Strains in Waste Distiller's Grains from Liquor Producing

    Institute of Scientific and Technical Information of China (English)

    游玲; 周黎军; 罗刚; 陈思慧; 王涛

    2014-01-01

    Application features of two bacterial strains (No. G7B-58 and S522B-41) of Bacillus in the fermentation of waste distiller's grains from liquor producing were studied. It's found that the two strains can adapt to the environment of waste distiller's grains, when inoculated in the waste distiller's grains separately, the cellulose of waste distiller's grains reduced by 16.9%and 16.6%, and the protein of waste distiller's grains increased by 35.0%and 39.2%, respectively. In the case of two strains inoculated in the waste distiller's grains together, the cellulose of waste distiller's grains decompose by 21.1%, the protein increased by 41.1%and the acidity reduced by 86%, with significantly reducing of acid, starch and residual sugar at the same time. For the scale of 10 kg waste distiller's grains, inoculated with 2%of the bacterial suspension, and piled up six days was appropriate. The results showed that the strains in the spent grains harmless or Grains fodder production had a good prospect of application. The results showed that the two bacteria strains had a good prospect of application in pollution control of waste distiller's grains and feed industry.%对2株Bacillus属细菌在白酒丢糟中的生长及降解纤维素的情况进行了研究。发现2株菌均可在丢糟中生长良好;分别可使丢糟纤维素降低16.9%及16.6%,蛋白质增加35.0%及39.2%。2株菌等比例混合接种于丢糟(2%接种量,处理10 kg丢糟),堆积6 d后可使丢糟纤维素降解21.1%,蛋白增加41.1%,酸度降低86%;同时丢糟中淀粉、残糖、酸度等指标也有明显降低。结果显示该2株细菌在丢糟饲料生产或丢糟无害化处理方面有很好的应用前景。

  20. Degradation characteristics of two Bacillus strains on the Microcystis aeruginosa

    Institute of Scientific and Technical Information of China (English)

    PEI Hai-yan; HU Wen-rong; QU Yin-bo; MU Rui-min; LI Xiao-cai

    2005-01-01

    The degradation kinetics of strains P05 and P07 and the degradation effects of mixed strain on Microcystis aeruginosa were studied. The results showed that: ( 1 ) The degradation processes of strains P05 and P07 on Microcystis aeruginosa accorded with the first-order reaction model when the range of Chl- a concentration was from 0 to 1500 μg/L. (2) The initial bacterium densities had a strong influence on the degradation velocity. The greater the initial bacterium density was, the faster the degradation was. The degradation velocity constants of P05 were 0.1913, 0.2175 and 0.3092 respectively, when bacterium densities were 4.8×105 , 4.8 × 106, 2.4 × 107 cells/ml. For strain P07, they were 0.1509, 0.1647 and 0.2708. The degradation velocity constant of strain P05 was higher than that of P07 when the bacterium density was under 4.8 × 105 cells/ml, but the constant increasing of P07 was quicker than that of P05. (3) The degradation effects of P05 and P07 strains did not antagonize. When the concentration of Chl-a was high, the degradation effects of mixed strain excelled that of any single strains. But with the decrease of the Chl-a concentration, this advantage was not clear. When the concentration was less than 180 μg/L, the degradation effects of mixed were consistent with that of strain P07.

  1. Novel bacterial consortia isolated from plastic garbage processing areas demonstrated enhanced degradation for low density polyethylene.

    Science.gov (United States)

    Skariyachan, Sinosh; Manjunatha, Vishal; Sultana, Subiya; Jois, Chandana; Bai, Vidya; Vasist, Kiran S

    2016-09-01

    This study aimed to formulate novel microbial consortia isolated from plastic garbage processing areas and thereby devise an eco-friendly approach for enhanced degradation of low-density polyethylene (LDPE). The LDPE degrading bacteria were screened and microbiologically characterized. The best isolates were formulated as bacterial consortia, and degradation efficiency was compared with the consortia formulated using known isolates obtained from the Microbial Culture Collection Centre (MTCC). The degradation products were analyzed by FTIR, GC-FID, tensile strength, and SEM. The bacterial consortia were characterized by 16S ribosomal DNA (rDNA) sequencing. The formulated bacterial consortia demonstrated 81 ± 4 and 38 ± 3 % of weight reduction for LDPE strips and LDPE pellets, respectively, over a period of 120 days. However, the consortia formulated by MTCC strains demonstrated 49 ± 4 and 20 ± 2 % of weight reduction for LDPE strips and pellets, respectively, for the same period. Furthermore, the three isolates in its individual application exhibited 70 ± 4, 68 ± 4, and 64 ± 4 % weight reduction for LDPE strips and 21 ± 2, 28 ± 2, 24 ± 2 % weight reduction for LDPE pellets over a period of 120 days (p product analysis showed structural changes and formation of bacterial film on degraded LDPE strips. The 16S rDNA characterization of bacterial consortia revealed that these organisms were novel strains and designated as Enterobacter sp. bengaluru-btdsce01, Enterobacter sp. bengaluru-btdsce02, and Pantoea sp. bengaluru-btdsce03. The current study thus suggests that industrial scale-up of these microbial consortia probably provides better insights for waste management of LDPE and similar types of plastic garbage.

  2. Biodegradation of endosulfan isomers and its metabolite endosulfate by two biosurfactant producing bacterial strains of Bordetella petrii.

    Science.gov (United States)

    Odukkathil, Greeshma; Vasudevan, Namasivayam

    2015-01-01

    The main objective of the investigation was to study the biodegradation of endosulfan isomers and its major metabolite endosulfate by two biosurfactant producing bacterial strains of Bordetella petrii. The significance of the study is to evaluate the capability of biosurfactant producing bacterial strains in enhancing the bioavailability of endosulfan. Sixty bacterial strains were isolated from the endosulfan degrading bacterial consortium and were screened for endosulfan degradation and biosurfactant production. Among those, two strains Bordetella petrii I GV 34 (Gene bank Accession No KJ02262) and Bordetella petrii II GV 36 (Gene bank Accession No KJ022625) were capable of degrading endosulfan with simultaneous biosurfactant production. Bordetella petrii I degraded 89% of α and 84% of β isomers of endosulfan whereas Bordetella petrii II degraded 82% of both the isomers. Both the strains were able to reduce the surface tension up to 19.6% and 21.4% with a minimum observed surface tension of 45 Dynes/cm and 44 Dynes/cm, respectively. The study revealed that the strains have the potential to enhance the degradation endosulfan residues in contaminated sites and water by biosurfactant production.

  3. Microbial activity and bacterial community structure during degradation of microcystins

    DEFF Research Database (Denmark)

    Christoffersen, K.; Lyck, Susanne; Winding, A.

    2002-01-01

    Degradation of realistic microcystin concentrations in lake water with indigenous bacteria was studied in laboratory and field experiments following inoculation with lysed toxic algal material containing microcystin primarily from Microcystis sp. or purified commercial microcystin-LR to microcosms...... experiment to evaluate the effects of organic lysates on bacterial proliferation in the absence of microcystin. An exponential decline of the dissolved toxins was observed in all cases with toxins present, and the degradation rates ranged between 0.5 and 1.0 d(-1). No lag phases were observed but slow...... including microcystins, and this resulted in a net accumulation of bacterial cells. The heterotrophic nanoflagellates responded quickly to the bacterial growth and probably consumed a considerable amount of the bacteria. The microbial activities returned to initial values within 5 to 6 d as the toxins...

  4. Aflatoxin B₁ degradation by a Pseudomonas strain.

    Science.gov (United States)

    Sangare, Lancine; Zhao, Yueju; Folly, Yawa Minnie Elodie; Chang, Jinghua; Li, Jinhan; Selvaraj, Jonathan Nimal; Xing, Fuguo; Zhou, Lu; Wang, Yan; Liu, Yang

    2014-10-23

    Aflatoxin B1 (AFB1), one of the most potent naturally occurring mutagens and carcinogens, causes significant threats to the food industry and animal production. In this study, 25 bacteria isolates were collected from grain kernels and soils displaying AFB1 reduction activity. Based on its degradation effectiveness, isolate N17-1 was selected for further characterization and identified as Pseudomonas aeruginosa. P. aeruginosa N17-1 could degrade AFB₁, AFB₂ and AFM₁ by 82.8%, 46.8% and 31.9% after incubation in Nutrient Broth (NB) medium at 37 °C for 72 h, respectively. The culture supernatant of isolate N17-1 degraded AFB₁ effectively, whereas the viable cells and intra cell extracts were far less effective. Factors influencing AFB1 degradation by the culture supernatant were investigated. Maximum degradation was observed at 55 °C. Ions Mn²⁺ and Cu²⁺ were activators for AFB1 degradation, however, ions Mg²⁺, Li⁺, Zn²⁺, Se²⁺, Fe³⁺ were strong inhibitors. Treatments with proteinase K and proteinase K plus SDS significantly reduced the degradation activity of the culture supernatant. No degradation products were observed based on preliminary LC-QTOF/MS analysis, indicating AFB₁ was metabolized to degradation products with chemical properties different from that of AFB₁. The results indicated that the degradation of AFB₁ by P. aeruginosa N17-1 was enzymatic and could have a great potential in industrial applications. This is the first report indicating that the isolate of P. aeruginosa possesses the ability to degrade aflatoxin.

  5. Hydrocarbon degradation, plant colonization and gene expression of alkane degradation genes by endophytic Enterobacter ludwigii strains

    Energy Technology Data Exchange (ETDEWEB)

    Yousaf, Sohail [AIT Austrian Institute of Technology GmbH, Bioresources Unit, A-2444 Seibersdorf (Austria); Afzal, Muhammad [AIT Austrian Institute of Technology GmbH, Bioresources Unit, A-2444 Seibersdorf (Austria); National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad (Pakistan); Reichenauer, Thomas G. [AIT Austrian Institute of Technology GmbH, Environmental Resources and Technologies Unit, A-2444 Seibersdorf (Austria); Brady, Carrie L. [Forestry and Agricultural Biotechnology Institute, Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria (South Africa); Sessitsch, Angela, E-mail: angela.sessitsch@ait.ac.at [AIT Austrian Institute of Technology GmbH, Bioresources Unit, A-2444 Seibersdorf (Austria)

    2011-10-15

    The genus Enterobacter comprises a range of beneficial plant-associated bacteria showing plant growth promotion. Enterobacter ludwigii belongs to the Enterobacter cloacae complex and has been reported to include human pathogens but also plant-associated strains with plant beneficial capacities. To assess the role of Enterobacter endophytes in hydrocarbon degradation, plant colonization, abundance and expression of CYP153 genes in different plant compartments, three plant species (Italian ryegrass, birdsfoot trefoil and alfalfa) were grown in sterile soil spiked with 1% diesel and inoculated with three endophytic E. ludwigii strains. Results showed that all strains were capable of hydrocarbon degradation and efficiently colonized the rhizosphere and plant interior. Two strains, ISI10-3 and BRI10-9, showed highest degradation rates of diesel fuel up to 68% and performed best in combination with Italian ryegrass and alfalfa. All strains expressed the CYP153 gene in all plant compartments, indicating an active role in degradation of diesel in association with plants. - Highlights: > E. ludwigii strains efficiently colonized plants in a non-sterile soil environment. > E. ludwigii strains efficiently expressed alkane degradation genes in plants. > E. ludwigii efficiently degraded alkane contaminations and promoted plant growth. > E. ludwigii interacted more effectively with Italian ryegrass than with other plants. > Degradation activity varied with plant and microbial genotype as well as with time. - Enterobacter ludwigii strains belonging to the E. cloacae complex are able to efficiently degrade alkanes when associated with plants and to promote plant growth.

  6. Aerobic Degradation of Dinitrotoluenes and Pathway for Bacterial Degradation of 2,6-Dinitrotoluene

    OpenAIRE

    Nishino, Shirley F.; Paoli, George C.; Spain, Jim C.

    2000-01-01

    An oxidative pathway for the mineralization of 2,4-dinitrotoluene (2,4-DNT) by Burkholderia sp. strain DNT has been reported previously. We report here the isolation of additional strains with the ability to mineralize 2,4-DNT by the same pathway and the isolation and characterization of bacterial strains that mineralize 2,6-dinitrotoluene (2,6-DNT) by a different pathway. Burkholderia cepacia strain JS850 and Hydrogenophaga palleronii strain JS863 grew on 2,6-DNT as the sole source of carbon...

  7. [Isolation and characterization of a halotolerant p-nitroaniline degrading strain S8].

    Science.gov (United States)

    Song, Cai-Xia; Deng, Xin-Ping; Li, Tian; Xiao, Wei

    2014-03-01

    A bacterial strain S8 was isolated from pesticide-contaminated sludge, which showed ability of utilizing p-nitroaniline as the sole source of carbon and nitrogen for growth. Based on the morphology, the physiological and biochemical characteristics, and the 16S rDNA sequence analysis, the strain was identified as Bacillus subtilis. Strain S8 showed high efficiency in p-nitroaniline degradation. 65.6% and 55.8% of p-nitroaniline (60 mg x L(-1) and 120 mg x L(-1)) were degraded by this strain within 72 hours under the optimal conditions of 31degrees C and pH 6.0. Besides, strain S8 degraded 49.5% p-nitroaniline in 7% NaCl and 27.4% p-nitroaniline in 10% NaCl (72 h), which showed that the strain S8 had a high salinity tolerance. When the LC-MS method was used for identification of the biodegradation products, six kinds of degradation products were found, two of which were identified as phenol and hydroquinone. To date, this is the first report on the degradation of p-nitroaniline by Bacillus subtilis. These results suggest that S8 could be a potential candidate for treating p-nitroaniline-contaminated saline wastewater.

  8. Identification and characterization of humic substances-degrading bacterial isolates from an estuarine environment.

    Science.gov (United States)

    Esham; Ye; Moran

    2000-12-01

    Bacterial isolates were obtained from enrichment cultures containing humic substances extracted from estuarine water using an XAD-8 resin. Eighteen isolates were chosen for phylogenetic and physiological characterization based on numerical importance in serial dilutions of the enrichment culture and unique colony morphology. Partial sequences of the 16S rRNA genes indicated that six of the isolates were associated with the alpha subclass of Proteobacteria, three with the gamma-Proteobacteria, and nine with the Gram-positive bacteria. Ten isolates degraded at least one (and up to six) selected aromatic single-ring compounds. Six isolates showed ability to degrade [(14)C]humic substances derived from the dominant salt marsh grass in the estuary from which they were isolated (Spartina alterniflora), mineralizing 0.4-1.1% of the humic substances over 4 weeks. A mixture of all 18 isolates did not degrade humic substances significantly faster than any of the individual strains, however, and no isolate degraded humic substances to the same extent as the natural marine bacterial community (3.0%). Similar studies with a radiolabeled synthetic lignin ([beta-(14)C]dehydropolymerisate) showed measurable levels of degradation by all 18 bacteria (3.0-8.8% in 4 weeks), but mineralization levels were again lower than that observed for the natural marine bacterial community (28.2%). Metabolic capabilities of the 18 isolates were highly variable and generally did not map to phylogenetic affiliation.

  9. 多氯联苯污染土壤好氧降解菌群的分离与鉴定%Isolation and Identification of Aerobic Polychlorinated Biphenyls-Degrading Bacterial Strains in PCBs-contaminated Soils

    Institute of Scientific and Technical Information of China (English)

    唐伟; 李英; 梁璐怡; 朱优峰; 王凤平

    2013-01-01

    Growth of microorganisms was stimulated by incubating polychlorinated biphenyl-polluted soils in Wenling and Xiaoshan with biphenyl as sole carbon and energy source.After 4 weeks,a total of thirty five strains of bacteria which were able to grow on biphenyl-containing minimal medium plates were isolated.Sixty percent of them are gram-negative bacteria.The results of 16S rRNA gene sequencing showed that the dominant strains are Stenotrophomonas sp.and Pandoraea sp..We chose two well growing strains from each soil to further study PCB-degradation.The four strains are Corynebacterium sp.WLS,Bacillus sp.WL10,Microbacterium sp.XS4 and Citrobacter sp.XS7.All of them were cultured in fresh mineral medium containing 100 mg ·L-1 biphenyl and 2 mg· L-1 2,3,4,5-tetrachlorobiphenyl (PCB61) for five days.The residual concentrations of PCB61 determined by gas chromatography showed all the strains could degrade PCB61.Especially,the transformation rate of PCB61 by Corynebacterium sp.WL 8,isolated from Wenling soil,reached 50%.This result will benefit further research of genetic screening,cloning and restructuring,as well as providing guidance for the cultivation of PCBs-degrading bacteria.%从浙江温岭和萧山长期受多氯联苯污染的土壤中,以联苯为唯一碳源和能源进行菌类的富集筛选共得到35株纯菌,其中革兰氏阴性菌占细菌总数的60%.对得到的35株菌株进行16S rRNA基因序列分析,结果显示温岭和萧山土壤中的优势菌属分别为寡养单胞菌(Stenotrophomonas sp.)和潘多拉菌属(Pandoraea sp.).挑选的4株细菌棒状杆菌(Corynebacterium sp.)WL8、芽孢杆菌(Bacillus sp.)WL10、微杆菌属(Microbacterium sp.)XS4和柠檬酸杆菌(Citrobacter sp.)XS7均可在联苯存在情况下共代谢降解2,3,4,5-四氯代多氯联苯(PCB61),其中从温岭土壤中筛选到的Corynebacterium sp.WL 8对PCB61的5d去除率达到了50%.

  10. Degradation of 4-fluorophenol by Arthrobacter sp strain IF1

    NARCIS (Netherlands)

    Ferreira, Maria Isabel M.; Marchesi, Julian R.; Janssen, Dick B.

    2008-01-01

    A Gram-positive bacterial strain capable of aerobic biodegradation of 4-fluorophenol (4-FP) as the sole source of carbon and energy was isolated by selective enrichment from soil samples collected near an industrial site. The organism, designated strain IF1, was identified as a member of the genus A

  11. Characterization of Rhodococcus wratislaviensis strain J3 that degrades 4-nitrocatechol and other nitroaromatic compounds.

    Science.gov (United States)

    Navrátilová, Jitka; Tvrzová, Ludmila; Durnová, Eva; Spröer, Cathrin; Sedlácek, Ivo; Neca, Jirí; Nemec, Miroslav

    2005-02-01

    The bacterial strain J3 was isolated from soil by selective enrichment on mineral medium containing 4-nitrocatechol as the sole carbon and energy source. This strain was identified as Rhodococcus wratislaviensis on the basis of morphology, biochemical, physiological and chemotaxonomic characterization and complete sequencing of the 16S rDNA gene. The isolated bacterium could utilize 4-nitrocatechol, 3-nitrophenol and 5-nitroguaiacol as sole carbon and energy sources. Stoichiometric release of nitrites was measured during degradation of 4-nitrocatechol both in growing cultures and for stationary phase cells. The J3 strain was unable to degrade 4-nitroguaiacol, 2-nitrophenol, 4-nitrophenol, 2,4-dinitrobenzoic acid, 4,5-dimethoxy-2-nitrobenzoic acid and 2,3-difluoro-6-nitrophenol. The J3 strain is deposited in the Czech Collection of Microorganisms as CCM 4930.

  12. 卡马西平降解菌的筛选分离及其降解机理%Isolation of a bacterial strain capable of carbamazepine degrading and biodegradation mechanism

    Institute of Scientific and Technical Information of China (English)

    杨林; 薛罡; 刘亚男

    2012-01-01

    Quite recently,among new emerging contaminants,pharmaceutical products and their active metabolites are an emerging environmental issue,due to their presence in the aquatic environment and potential for impacts on wildlife and humans.Carbamazepine was one of the most frequently detected pharmaceuticals in surface water and even in drinking water and at the relatively high concentration levels.Moreover,this drug has displayed high chronic ecotoxicity.A strain of carbamazepine-degrading bacterium was isolated from biological aerated filter treating pharmaceutical wastewater.It was identified as Pseudomonas putida YK-6,based on biochemical test,16S rRNA gene sequence analysis.Strain YK-6 could grow in liquid mineral salt medium with carbamazepine as sole source of carbon,nitrogen and energy.HPLC analysis revealed that the carbamazepine degradation rate by YK-6 after 5 days was 54.66% at pH 7.2,30℃,initial carbamazepine concentration of 20 mg/L and oscillation rate of 160 r/min.Possible degradation pathway of carbamazepine by strain YK-6 was the biological oxidation.The CBZ was oxidized into CBZ-EP,and then CBZ-EP was converted to CBZ-DiOH through the hydrolysis.CBZ-DiOH was cracked into aniline and o-benzoic acid through oxidative decarboxylation by pyruvate and under the reducing the role of coenzyme NADH,and then the late one was further oxidized until the final mineralization.%药品污染物日益成为新兴污染物研究的重点,药品卡马西平因具有多种药效被广泛使用,在环境中频繁被检出,且浓度较高,不易去除,通常作为环境中药品污染状况的指示化合物。本研究从长期用于去除药品废水的曝气生物滤池中分离出一株细菌YK-6,其能以卡马西平为惟一碳源、氮源和能源生长,通过生理生化以及16S rDNA基因序列分析鉴定并命名为Pseudomonas putida YK-6。该菌株YK-6在pH为7.2、温度30℃、卡马西平初始浓度为20 mg/L、摇床振荡速率为160 r

  13. 1株扑热息痛降解新菌株的选育及其代谢特性研究%Isolation, Identification and Biodegradation Characteristics of a New Bacterial Strain Degrading Paracetamol

    Institute of Scientific and Technical Information of China (English)

    魏芳; 周卿伟; 冷守琴; 张丽丽; 陈建孟

    2011-01-01

    通过选择性富集培养,从活性污泥样品中选育到1株能以扑热息痛为唯一碳源生长的好氧细菌F1.根据菌株F1的形态特征、生理生化特性、16S rRNA基因序列分析及和Biolog测试,初步鉴定为亲铜(Cupriavidus necator)菌属.菌株F1降解扑热息痛最适pH值和温度分别为7.0和30℃;菌株降解扑热息痛的过程遵循Haldane动力学模型,其最大比生长速率μ为0.097 h;其细胞产率系数为0.21 mg/mg.当扑热息痛浓度低于400 mg/L,其降解量与CO生成量呈线性关系,与扑热息痛完全矿化生成CO的理论系数值相近,同时该浓度下TOC去除率为92%,表明菌株降解扑热息痛具有较高的矿化率.代谢产物分析表明菌株F1降解扑热息痛可能的主要途径为:菌株首先脱掉扑热息痛乙酰基形成对氨基苯酚,对氨基苯酚进一步脱氨基转化为对苯二酚,继而裂解开环进入TCA循环.%A paracetamol-degrading bacterium Fl was isolated by selective enrichment from activated sludge samples. Based on the morphological characteristics, physiological and biochemical characteristics, 16S rRNA sequence analysis and Biolog identification,this strain was tentatively identified as Cupriavidus necator (previously Ralstonia eutropha ). The optimal pH and temperature for Fl biodegradation in shaking flasks were 7.0 and 30℃, respectively. The degrading process of the strain Fl followed the Haldane kinetic model. The maximum specific growth rate and yield coefficient were 0. 097 h-1 and 0. 21 mg/mg, respectively. At concentrations below 400 mg/mL, the production of CO2 was linearly correlated with paracetamol consumed with a coefficient of 1. 5805, close to the theoretical coefficient value. Meanwhile, TOC removal efficiency up to 92% was obtained at the initial concentration of 400 mg/L. The results indicated that strain Fl had a high mineralization extent for paracetamol. The identified metabolites suggested a possible main route for paracetamol

  14. Ecofriendly degradation, decolorization and detoxification of textile effluent by a developed bacterial consortium.

    Science.gov (United States)

    Phugare, Swapnil S; Kalyani, Dayanand C; Surwase, Shripad N; Jadhav, Jyoti P

    2011-07-01

    Present study illustrates the effectual decolorization and degradation of the textile effluent using a developed bacterial consortium SDS, consisted of bacterial species Providencia sp. SDS and Pseudomonas aeuroginosa strain BCH, originally isolated from dye contaminated soil. The intensive metabolic activity of the consortium SDS led to complete decolorization of textile effluent within 20 h at pH 7 and temperature 30°C. Significant induction in the activities of veratryl alcohol oxidase, laccase, azoreductase and DCIP reductase were observed during decolorization, which indicates their involvement in decolorization and degradation process. The decolorization and biodegradation was monitored using UV-vis spectroscopy, IR spectroscopy, HPLC and HPTLC analysis. Toxicological analysis of effluent before and after treatment was performed using classical Allium cepa test. Investigations of various toxicological parameters viz, oxidative stress response, cytotoxicity, genotoxicity and phytotoxicity, collectively concludes that, the toxicity of effluent reduces significantly after treatment with consortium SDS.

  15. Biodegradation of Ochratoxin A by Bacterial Strains Isolated from Vineyard Soils

    Directory of Open Access Journals (Sweden)

    Palmira De Bellis

    2015-11-01

    Full Text Available Ochratoxin A (OTA is a mycotoxin with a main nephrotoxic activity contaminating several foodstuffs. In the present report, five soil samples collected from OTA-contaminated vineyards were screened to isolate microorganisms able to biodegrade OTA. When cultivated in OTA-supplemented medium, OTA was converted in OTα by 225 bacterial isolates. To reveal clonal relationships between isolates, molecular typing by using an automated rep-PCR system was carried out, thus showing the presence of 27 different strains (rep-PCR profiles. The 16S-rRNA gene sequence analysis of an isolate representative of each rep-PCR profiles indicated that they belonged to five bacterial genera, namely Pseudomonas, Leclercia, Pantoea, Enterobacter, and Acinetobacter. However, further evaluation of OTA-degrading activity by the 27 strains revealed that only Acinetobacter calcoaceticus strain 396.1 and Acinetobacter sp. strain neg1, consistently conserved the above property; their further characterization showed that they were able to convert 82% and 91% OTA into OTα in six days at 24 °C, respectively. The presence of OTα, as the unique OTA-degradation product was confirmed by LC-HRMS. This is the first report on OTA biodegradation by bacterial strains isolated from agricultural soils and carried out under aerobic conditions and moderate temperatures. These microorganisms might be used to detoxify OTA-contaminated feed and could be a new source of gene(s for the development of a novel enzymatic detoxification system.

  16. Biodegradation of malathion, α- and β-endosulfan by bacterial strains isolated from agricultural soil in Veracruz, Mexico.

    Science.gov (United States)

    Jimenez-Torres, Catya; Ortiz, Irmene; San-Martin, Pablo; Hernandez-Herrera, R Idalia

    2016-12-01

    The objective of this study was to evaluate the capacity of two bacterial strains isolated, cultivated, and purified from agricultural soils of Veracruz, Mexico, for biodegradation and mineralisation of malathion (diethyl 2-(dimethoxyphosphorothioyl) succinate) and α- and β-endosulfan (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6-9-methano-2,4,3-benzodioxathiepine-3-oxide). The isolated bacterial strains were identified using biochemical and morphological characterization and the analysis of their 16S rDNA gene, as Enterobacter cloacae strain PMM16 (E1) and E. amnigenus strain XGL214 (M1). The E1 strain was able to degrade endosulfan, whereas the M1 strain was capable of degrading both pesticides. The E1 strain degraded 71.32% of α-endosulfan and 100% of β-endosulfan within 24 days. The absence of metabolites, such as endosulfan sulfate, endosulfan lactone, or endosulfan diol, would suggest degradation of endosulfan isomers through non-oxidative pathways. Malathion was completely eliminated by the M1 strain. The major metabolite was butanedioic acid. There was a time-dependent increase in bacterial biomass, typical of bacterial growth, correlated with the decrease in pesticide concentration. The CO2 production also increased significantly with the addition of pesticides to the bacterial growth media, demonstrating that, under aerobic conditions, the bacteria utilized endosulfan and malathion as a carbon source. Here, two bacterial strains are shown to metabolize two toxic pesticides into non-toxic intermediates.

  17. Simazine degradation in bioaugmented soil: urea impact and response of ammonia-oxidizing bacteria and other soil bacterial communities.

    Science.gov (United States)

    Guo, Qingwei; Wan, Rui; Xie, Shuguang

    2014-01-01

    The objective of this study was to investigate the impact of exogenous urea nitrogen on ammonia-oxidizing bacteria (AOB) and other soil bacterial communities in soil bioaugmented for simazine remediation. The previously isolated simazine-degrading Arthrobacter sp. strain SD1 was used to degrade the herbicide. The effect of urea on the simazine degradation capacity of the soil bioaugmented with Arthrobacter strain SD1 was assessed using quantitative PCR targeting the s-triazine-degrading trzN and atzC genes. Structures of bacterial and AOB communities were characterized using terminal restriction fragment length polymorphism. Urea fertilizer could affect simazine biodegradation and decreased the proportion of its trzN and atzC genes in soil augmented with Arthrobacter strain SD1. Bioaugmentation process could significantly alter the structures of both bacterial and AOB communities, which were strongly affected by urea amendment, depending on the dosage. This study could provide some new insights towards s-triazine bioremediation and microbial ecology in a bioaugmented system. However, further studies are necessary in order to elucidate the impact of different types and levels of nitrogen sources on s-triazine-degraders and bacterial and AOB communities in bioaugmented soil.

  18. Productive degradation of the biocide benzylbenzoate by Acinetobacter sp. strain AG1 isolated from the River Elbe.

    Science.gov (United States)

    Göttsching, Anja; Schmidt, Stefan

    2007-04-01

    From water sampled in the River Elbe, we isolated a bacterial strain able to use the biocidal compound benzylbenzoate as its sole source of carbon and energy under aerobic conditions. This isolate was tentatively assigned to the genus Acinetobacter due to its morphological, physiological and partial SSU rRNA gene sequence properties. The productive bacterial degradation of the biocide benzylbenzoate was demonstrated, and the catabolic sequence was elucidated biochemically. Growth experiments, along with enzymatic studies, demonstrated that strain Acinetobacter sp. AG1 hydrolyzed benzylbenzoate enzymatically to yield benzylalcohol and benzoate. Benzylalcohol was further transformed to benzoate via benzaldehyde. Benzoate was subsequently channeled via catechol into the oxoadipate pathway for further degradation.

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

    Science.gov (United States)

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

    2014-11-01

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

  20. Bacterial diversity of a consortium degrading high-molecular-weight polycyclic aromatic hydrocarbons in a two-liquid phase biosystem.

    Science.gov (United States)

    Lafortune, Isabelle; Juteau, Pierre; Déziel, Eric; Lépine, François; Beaudet, Réjean; Villemur, Richard

    2009-04-01

    High-molecular-weight (HMW) polycyclic aromatic hydrocarbons (PAHs) are pollutants that persist in the environment due to their low solubility in water and their sequestration by soil and sediments. Although several PAH-degrading bacterial species have been isolated, it is not expected that a single isolate would exhibit the ability to degrade completely all PAHs. A consortium composed of different microorganisms can better achieve this. Two-liquid phase (TLP) culture systems have been developed to increase the bioavailability of poorly soluble substrates for uptake and biodegradation by microorganisms. By combining a silicone oil-water TLP system with a microbial consortium capable of degrading HMW PAHs, we previously developed a highly efficient PAH-degrading system. In this report, we characterized the bacterial diversity of the consortium with a combination of culture-dependent and culture-independent methods. Polymerase chain reaction (PCR) of part of the 16S ribosomal RNA gene (rDNA) sequences combined with denaturing gradient gel electrophoresis was used to monitor the bacterial population changes during PAH degradation of the consortium when pyrene, chrysene, and benzo[a]pyrene were provided together or separately in the TLP cultures. No substantial changes in bacterial profiles occurred during biodegradation of pyrene and chrysene in these cultures. However, the addition of the low-molecular-weight PAHs phenanthrene or naphthalene in the system favored one bacterial species related to Sphingobium yanoikuyae. Eleven bacterial strains were isolated from the consortium but, interestingly, only one-IAFILS9 affiliated to Novosphingobium pentaromativorans-was capable of growing on pyrene and chrysene as sole source of carbon. A 16S rDNA library was derived from the consortium to identify noncultured bacteria. Among 86 clones screened, 20 were affiliated to different bacterial species-genera. Only three strains were represented in the screened clones. Eighty

  1. [Characterization of a thermophilic Geobacillus strain DM-2 degrading hydrocarbons].

    Science.gov (United States)

    Liu, Qing-kun; Wang, Jun; Li, Guo-qiang; Ma, Ting; Liang, Feng-lai; Liu, Ru-lin

    2008-12-01

    A thermophilic Geobacillus strain DM-2 from a deep-subsurface oil reservoir was investigated on its capability of degrading crude oil under various conditions as well as its characters on degrading hydrocarbons in optimal conditions. The results showed that Geobacillus strain DM-2 was able to degrade crude oil under anoxic wide-range conditions with pH ranging from 4.0 to 10.0, high temperature in the range of 45-70 degrees C and saline concentration ranging from 0.2% to 3.0%. Furthermore, the optimal temperature and pH value for utilizing hydrocarbons by the strain were 60 degrees C and 7.0, respectively. Under such optimal conditions, the strain utilized liquid paraffine emulsified by itself as its carbon source for growth; further analysis by gas chromatography (GC) and infrared absorption spectroscopy demonstrated that it was able to degrade n-alkanes (C14-C30), branched-chain alkanes and aromatic hydrocarbons in crude oil and could also utilize long-chain n-alkanes from C16 to C36, among of which the degradation efficiency of C28 was the highest, up to 88.95%. One metabolite of the strain oxidizing alkanes is fatty acid.While utilizing C16 as carbon source for 5 d, only one fatty acid-acetic acid was detected by HPLC and MS as the product, with the amount of 0.312 g/L, which indicated that it degraded n-alkanes with pathway of inferior terminal oxidation,and then followed by a beta-oxidation pathway. Due to its characters of efficient emulsification, high-performance degradation of hydrocarbons and fatty-acid production under high temperature and anoxic condition, the strain DM-2 may be potentially applied to oil-waste treatment and microbial enhanced heavy oil recovery in extreme conditions.

  2. Bacterial degradation of moxifloxacin in the presence of acetate as a bulk substrate.

    Science.gov (United States)

    Carvalho, M F; Maia, A S; Tiritan, M E; Castro, P M L

    2016-03-01

    Fluoroquinolones constitute a group of emerging pollutants and their occurrence in different environmental compartments is becoming object of increasing public concern due to their ecotoxicological effects and the potential to develop resistant bacteria. This study aimed to investigate the biodegradation of moxifloxacin (MOX), for which studies in the literature are very scarce. An activated sludge (AS) consortium and three bacterial strains able to degrade fluoroaromatic compounds - strains F11, FP1 and S2 - were tested. Biodegradation studies were conducted using acetate as a bulk carbon source. Strain F11 showed the highest biodegradation capacity, being able to completely consume and dehalogenate 7.5 μM of the target antibiotic when daily co-supplemented with acetate present as a readily degradable organic substrate in wastewaters. MOX could be used by strain F11 as a sole nitrogen source but the presence of an external nitrogen source in the culture medium was essential for complete biodegradation. Strain F11 was capable of completely consuming MOX in a range between 2 and 11 μM, although stoichiometric fluoride release was not obtained for the highest tested concentration. The antibacterial activity of residual MOX and of the metabolic products potentially resultant from the biodegradation process was investigated by agar diffusion tests, demonstrating that MOX biodegradation is associated with the elimination of the antibacterial properties of the target antibiotic and of the produced metabolites, which is an important result, as the activity of antibiotics and/or their metabolites in the environment, even at low levels, may lead to the development of resistant bacterial strains. Overall, the results obtained in this study suggest that strain F11 is a promising microorganism for the treatment of waters contaminated with MOX, where it could be used for bioaugmentation/bioremediation purposes. To the best of our knowledge, this is the first study reporting

  3. Isolation of a Bacterium Strain Degraded Agar

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    One in 58 strains of bacteria isolated from the compost showed clear colonies after a few days of growth on the plates containing medium made of only agar and water.Water suspension contained only agar (2 and 8g·L -1 ) with two controls (normal saline,LB medium) was inoculated with the bacterium BR5-1 to see whether there was an increasement of the alive bacteria concentration after 48 h of the growth.The results showed that there was a significant rising of the alive bacteria concentration in the agar susp...

  4. Isolation and characterization of different bacterial strains for bioremediation of n-alkanes and polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Guermouche M'rassi, A; Bensalah, F; Gury, J; Duran, R

    2015-10-01

    Crude oil is a common environmental pollutant composed of a large number of both aromatic and aliphatic hydrocarbons. Biodegradation is carried out by microbial communities that are important in determining the fate of pollutants in the environment. The intrinsic biodegradability of the hydrocarbons and the distribution in the environment of competent degrading microorganisms are crucial information for the implementation of bioremediation processes. In the present study, the biodegradation capacities of various bacteria toward aliphatic and aromatic hydrocarbons were determined. The purpose of the study was to isolate and characterize hydrocarbon-degrading bacteria from contaminated soil of a refinery in Arzew, Algeria. A collection of 150 bacterial strains was obtained; the bacterial isolates were identified by 16S rRNA gene sequencing and their ability to degrade hydrocarbon compounds characterized. The isolated strains were mainly affiliated to the Gamma-Proteobacteria class. Among them, Pseudomonas spp. had the ability to metabolize high molecular weight hydrocarbon compounds such as pristane (C19) at 35.11 % by strain LGM22 and benzo[a] pyrene (C20) at 33.93 % by strain LGM11. Some strains were able to grow on all the hydrocarbons tested including octadecane, squalene, phenanthrene, and pyrene. Some strains were specialized degrading only few substrates. In contrast, the strain LGM2 designated as Pseudomonas sp. was found able to degrade both linear and branched alkanes as well as low and high poly-aromatic hydrocarbons (PAHs). The alkB gene involved in alkane degradation was detected in LGM2 and other Pseudomonas-related isolates. The capabilities of the isolated bacterial strains to degrade alkanes and PAHs should be of great practical significance in bioremediation of oil-contaminated environments.

  5. Degradation of polyester polyurethane by a newly isolated soil bacterium, Bacillus subtilis strain MZA-75.

    Science.gov (United States)

    Shah, Ziaullah; Krumholz, Lee; Aktas, Deniz Fulya; Hasan, Fariha; Khattak, Mutiullah; Shah, Aamer Ali

    2013-11-01

    A polyurethane (PU) degrading bacterial strain MZA-75 was isolated from soil through enrichment technique. The bacterium was identified through 16S rRNA gene sequencing, the phylogenetic analysis indicated the strain MZA-75 belonged to genus Bacillus having maximum similarity with Bacillus subtilis strain JBE0016. The degradation of PU films by strain MZA-75 in mineral salt medium (MSM) was analyzed by scanning electron microscopy (SEM), fourier transform infra-red spectroscopy (FT-IR) and gel permeation chromatography (GPC). SEM revealed the appearance of widespread cracks on the surface. FTIR spectrum showed decrease in ester functional group. Increase in polydispersity index was observed in GPC, which indicates chain scission as a result of microbial treatment. CO2 evolution and cell growth increased when PU was used as carbon source in MSM in Sturm test. Increase in both cell associated and extracellular esterases was observed in the presence of PU indicated by p-Nitrophenyl acetate (pNPA) hydrolysis assay. Analysis of cell free supernatant by gas chromatography-mass spectrometry (GC-MS) revealed that 1,4-butanediol and adipic acid monomers were produced. Bacillus subtilis strain MZA-75 can degrade the soft segment of polyester polyurethane, unfortunately no information about the fate of hard segment could be obtained. Growth of strain MZA-75 in the presence of these metabolites indicated mineralization of ester hydrolysis products into CO2 and H2O.

  6. Degradation and mineralization of atrazine by a soil bacterial isolate.

    OpenAIRE

    Radosevich, M.; Traina, S.J.; Hao, Y. L.; Tuovinen, O H

    1995-01-01

    An atrazine-degrading bacterial culture was isolated from an agricultural soil previously impacted by herbicide spills. The organism was capable of using atrazine under aerobic conditions as the sole source of C and N. Cyanuric acid could replace atrazine as the sole source of N, indicating that the organism was capable of ring cleavage. Ring cleavage was confirmed in 14CO2 evolution experiments with [U-14C-ring]atrazine. Between 40 and 50% of ring-14C was mineralized to 14CO2. [14C]biuret an...

  7. Bacterial degradation of cyanide and its metal complexes under alkaline conditions.

    Science.gov (United States)

    Luque-Almagro, Víctor M; Huertas, María-J; Martínez-Luque, Manuel; Moreno-Vivián, Conrado; Roldán, M Dolores; García-Gil, L Jesús; Castillo, Francisco; Blasco, Rafael

    2005-02-01

    A bacterial strain able to use cyanide as the sole nitrogen source under alkaline conditions has been isolated. The bacterium was classified as Pseudomonas pseudoalcaligenes by comparison of its 16S RNA gene sequence to those of existing strains and deposited in the Coleccion Espanola de Cultivos Tipo (Spanish Type Culture Collection) as strain CECT5344. Cyanide consumption is an assimilative process, since (i) bacterial growth was concomitant and proportional to cyanide degradation and (ii) the bacterium stoichiometrically converted cyanide into ammonium in the presence of l-methionine-d,l-sulfoximine, a glutamine synthetase inhibitor. The bacterium was able to grow in alkaline media, up to an initial pH of 11.5, and tolerated free cyanide in concentrations of up to 30 mM, which makes it a good candidate for the biological treatment of cyanide-contaminated residues. Both acetate and d,l-malate were suitable carbon sources for cyanotrophic growth, but no growth was detected in media with cyanide as the sole carbon source. In addition to cyanide, P. pseudoalcaligenes CECT5344 used other nitrogen sources, namely ammonium, nitrate, cyanate, cyanoacetamide, nitroferricyanide (nitroprusside), and a variety of cyanide-metal complexes. Cyanide and ammonium were assimilated simultaneously, whereas cyanide strongly inhibited nitrate and nitrite assimilation. Cyanase activity was induced during growth with cyanide or cyanate, but not with ammonium or nitrate as the nitrogen source. This result suggests that cyanate could be an intermediate in the cyanide degradation pathway, but alternative routes cannot be excluded.

  8. Identification of a Marine Bacillus Strain C5 and Parathion-Methyl Degradation Characteristics of the Extracellular Esterase B1

    Directory of Open Access Journals (Sweden)

    Jianhua Hao

    2014-01-01

    Full Text Available A bacterial strain C5 that can produce new type of marine esterase was isolated and screened from marine sludge. According to 16S rRNA sequence analysis and physiological and biochemical experiments, the strain was identified as Bacillus subtilis. A single isozyme with a molecular weight of 86 kDa was observed by SDS-PAGE and native-PAGE. On this basis, the mechanism of esterase B1 secreted by strain C5 degrading parathion-methyl was explored, and the effects of temperature and pH on the degradation rate were investigated. From the results, p-nitrophenol was one of the degradation products of B1 degrading parathion-methyl, and the best degradation effect could be achieved at the temperature of 40°C and the neutral pH value.

  9. Genome engineering and gene expression control for bacterial strain development.

    Science.gov (United States)

    Song, Chan Woo; Lee, Joungmin; Lee, Sang Yup

    2015-01-01

    In recent years, a number of techniques and tools have been developed for genome engineering and gene expression control to achieve desired phenotypes of various bacteria. Here we review and discuss the recent advances in bacterial genome manipulation and gene expression control techniques, and their actual uses with accompanying examples. Genome engineering has been commonly performed based on homologous recombination. During such genome manipulation, the counterselection systems employing SacB or nucleases have mainly been used for the efficient selection of desired engineered strains. The recombineering technology enables simple and more rapid manipulation of the bacterial genome. The group II intron-mediated genome engineering technology is another option for some bacteria that are difficult to be engineered by homologous recombination. Due to the increasing demands on high-throughput screening of bacterial strains having the desired phenotypes, several multiplex genome engineering techniques have recently been developed and validated in some bacteria. Another approach to achieve desired bacterial phenotypes is the repression of target gene expression without the modification of genome sequences. This can be performed by expressing antisense RNA, small regulatory RNA, or CRISPR RNA to repress target gene expression at the transcriptional or translational level. All of these techniques allow efficient and rapid development and screening of bacterial strains having desired phenotypes, and more advanced techniques are expected to be seen.

  10. Isolation and Characterization of a Thermophilic Oil-Degrading Bacterial Consortium

    Institute of Scientific and Technical Information of China (English)

    Gu Guizhou; Li Zheng; Zhao Dongfeng; Zhao Chaocheng

    2013-01-01

    In this study, a thermophilic oil-degrading bacterial consortium KO8-2 growing within the temperature range of 45-65℃(with 55℃being the optimum temperature) was isolated from oil-contaminated soil of Karamay in Xinjiang, China. Denaturing gradient gel electrophoresis (DGGE) showed that there were nine strains included in KO8-2, which originated from the genera of Bacillus, Geobacillus and Clostridium. They all belonged to thermophilic bacteria, and had been previously proved as degraders of at least one petroleum fraction. The crude oil degraded by KO8-2 was analyzed by infrared spectrophotometry, hydrocarbon group type analysis and gas chromatography. The results indicated that the bacterial consortium KO8-2 was able to utilize 64.33%of saturates, 27.06%of aromatics, 13.24%of resins and the oil removal efifciency reached up to 58.73%at 55℃when the oil concentration was 10 g/L. Detailed analysis showed that KO8-2 was able to utilize the hydrocarbon components before C19, and the n-alkanes ranging from C20-C33 were signiif-cantly degraded. The ratios of nC17/Pr and nC18/Ph were 3.12 and 3.87, respectively, before degradation, whereas after degradation the ratios reduced to 0.21 and 0.38, respectively. Compared with the control sample, the oil removal efifciency in KO8-2 composting reactor reached 50.12%after a degradation duration of 60 days.

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

    Institute of Scientific and Technical Information of China (English)

    PEI Haiyan; HU Wenrong

    2006-01-01

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

  12. Diversity of Streptococcus mutans strains in bacterial interspecies interactions

    NARCIS (Netherlands)

    Li, X.; Hoogenkamp, M.A.; Ling, J.; Crielaard, W.; Deng, D.M.

    2014-01-01

    Biofilms are matrix-enclosed microbial population adhere to each other and to surfaces. Compared to planktonic bacterial cells, biofilm cells show much higher levels of antimicrobial resistance. We aimed to investigate Streptococcus mutans strain diversity in biofilm formation and chlorhexidine (CHX

  13. Effect of CuO Nanoparticles over Isolated Bacterial Strains from Agricultural Soil

    Directory of Open Access Journals (Sweden)

    Sandra I. Concha-Guerrero

    2014-01-01

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

  14. Identification and characterisation of potential biofertilizer bacterial strains

    Science.gov (United States)

    Karagöz, Kenan; Kotan, Recep; Dadaşoǧlu, Fatih; Dadaşoǧlu, Esin

    2016-04-01

    In this study we aimed that isolation, identification and characterizations of PGPR strains from rhizosphere of legume plants. 188 bacterial strains isolated from different legume plants like clover, sainfoin and vetch in Erzurum province of Turkey. These three plants are cultivated commonly in the Erzurum province. It was screen that 50 out of 188 strains can fix nitrogen and solubilize phosphate. These strains were identified via MIS (Microbial identification system). According to MIS identification results, 40 out of 50 strains were identified as Bacillus, 5 as Pseudomonas, 3 as Paenibacillus, 1 as Acinetobacter, 1 as Brevibacterium. According to classical test results, while the catalase test result of all isolates are positive, oxidase, KOH and starch hydrolysis rest results are variable.

  15. Draft Genome Sequence of MCPA-Degrading Sphingomonas sp. Strain ERG5, Isolated from a Groundwater Aquifer in Denmark

    DEFF Research Database (Denmark)

    Nielsen, Tue Kjærgaard; Kot, Witold; Sørensen, Sebastian R

    2015-01-01

    Sphingomonas sp. strain ERG5 was isolated from a bacterial community, originating from a groundwater aquifer polluted with low pesticide concentrations. This bacterium degrades 2-methyl-4-chlorophenoxyacetic acid (MCPA) in a wide spectrum of concentrations and has been shown to function in bioaug...

  16. Characterization of a strain capable of degrading a herbicide mixture of quinclorac and bensulfuronmethyl

    Institute of Scientific and Technical Information of China (English)

    LU Zhen-Mei; LI Zi-Mu; SANG Li-Ya; MIN Hang

    2008-01-01

    A bacterial strain,designated as LS,was isolated from a contaminated soil and was found to be capable of utilizing quinelorac,bensulfuromnethyl,and a mixture of the two as carbon and energy sources for growth.Strain LS was identified as Ochrobactrum sp.based on its physiological-biochemical properties,16S rDNA sequences,and phylogenetic analysis.The extent of degradation of quinclorac and bensulfuronmethyl at initial concentrations of 1.5 and 0.1 g L-1 was 90% and 67%,respectively,as measured by high performance liquid chromatography (HPLC).When a herbicide mixture of 0.34 g L-1 quinelorac and 0.02 g L-1 bensulfuronmethyl was applied as carbon sources,quinclorac and bensulfuronmethyl were degraded at 95.7% and 67.5%,respectively.It appears that quinclorac is utilized more easily in a mixture than in a single state.The optimal temperature for growth of strain LS was 37℃.Strain LS grew well at pH 6 to 9 and had the highest degradation level for quinclorac and bensulfuronmethyl at an initial pH of 7 and 8,respectively.Addition of 0.25 g L-1 yeast extract could promote the growth and extent of degradation of quinclorac and bensulfuronmethyl by strain LS.Strain LS also showed the capability to degrade other aromatic compounds such as catechol,propisochlor,4-chloro-2-methylphenoxyacetic acid sodium (MCPA-Na) and imazethapy.The isolate LS shows a huge potential to be used in bioremediation for treating complex herbicide residues.

  17. Plant Cell Wall Degradation by Saprophytic Bacillus subtilis Strains: Gene Clusters Responsible for Rhamnogalacturonan Depolymerization▿

    Science.gov (United States)

    Ochiai, Akihito; Itoh, Takafumi; Kawamata, Akiko; Hashimoto, Wataru; Murata, Kousaku

    2007-01-01

    Plant cell wall degradation is a premier event when Bacillus subtilis, a typical saprophytic bacterium, invades plants. Here we show the degradation system of rhamnogalacturonan type I (RG-I), a component of pectin from the plant cell wall, in B. subtilis strain 168. Strain 168 cells showed a significant growth on plant cell wall polysaccharides such as pectin, polygalacturonan, and RG-I as a carbon source. DNA microarray analysis indicated that three gene clusters (yesOPQRSTUVWXYZ, ytePQRST, and ybcMOPST-ybdABDE) are inducibly expressed in strain 168 cells grown on RG-I. Cells of an industrially important bacterium, B. subtilis strain natto, fermenting soybeans also express the gene cluster including the yes series during the assimilation of soybean used as a carbon source. Among proteins encoded in the yes cluster, YesW and YesX were found to be novel types of RG lyases releasing disaccharide from RG-I. Genetic and enzymatic properties of YesW and YesX suggest that strain 168 cells secrete YesW, which catalyzes the initial cleavage of the RG-I main chain, and the resultant oligosaccharides are converted to disaccharides through the extracellular exotype YesX reaction. The disaccharide is finally degraded into its constituent monosaccharides through the reaction of intracellular unsaturated galacturonyl hydrolases YesR and YteR. This enzymatic route for RG-I degradation in strain 168 differs significantly from that in plant-pathogenic fungus Aspergillus aculeatus. This is, to our knowledge, the first report on the bacterial system for complete RG-I main chain degradation. PMID:17449691

  18. Plant cell wall degradation by saprophytic Bacillus subtilis strains: gene clusters responsible for rhamnogalacturonan depolymerization.

    Science.gov (United States)

    Ochiai, Akihito; Itoh, Takafumi; Kawamata, Akiko; Hashimoto, Wataru; Murata, Kousaku

    2007-06-01

    Plant cell wall degradation is a premier event when Bacillus subtilis, a typical saprophytic bacterium, invades plants. Here we show the degradation system of rhamnogalacturonan type I (RG-I), a component of pectin from the plant cell wall, in B. subtilis strain 168. Strain 168 cells showed a significant growth on plant cell wall polysaccharides such as pectin, polygalacturonan, and RG-I as a carbon source. DNA microarray analysis indicated that three gene clusters (yesOPQRSTUVWXYZ, ytePQRST, and ybcMOPST-ybdABDE) are inducibly expressed in strain 168 cells grown on RG-I. Cells of an industrially important bacterium, B. subtilis strain natto, fermenting soybeans also express the gene cluster including the yes series during the assimilation of soybean used as a carbon source. Among proteins encoded in the yes cluster, YesW and YesX were found to be novel types of RG lyases releasing disaccharide from RG-I. Genetic and enzymatic properties of YesW and YesX suggest that strain 168 cells secrete YesW, which catalyzes the initial cleavage of the RG-I main chain, and the resultant oligosaccharides are converted to disaccharides through the extracellular exotype YesX reaction. The disaccharide is finally degraded into its constituent monosaccharides through the reaction of intracellular unsaturated galacturonyl hydrolases YesR and YteR. This enzymatic route for RG-I degradation in strain 168 differs significantly from that in plant-pathogenic fungus Aspergillus aculeatus. This is, to our knowledge, the first report on the bacterial system for complete RG-I main chain degradation.

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

    OpenAIRE

    2016-01-01

    Electrode respiring bacteria (ERB) possess a great potential for many biotechnological applications such as microbial electrochemical remediation systems (MERS) because of their exoelectrogenic capabilities to degrade xenobiotic pollutants. Very few ERB have been isolated from MERS, those exhibited a bioremediation potential towards organic contaminants. Here we report once such bacterial strain, Stenotrophomonas maltophilia MK2, a facultative anaerobic bacterium isolated from a hydrocarbon f...

  20. Antimicrobial resistance of bacterial strains isolated from avian cellulitis

    Directory of Open Access Journals (Sweden)

    MM Santos

    2014-03-01

    Full Text Available Avian cellulitis is an inflammatory process in the subcutaneous tissue, mainly located in the abdomen and thighs. This problem is commonly observed in poultry at slaughter and it is considered one of the major causes of condemnation of carcasses in Brazil. The aim of this study was to perform the microbial isolation of lesions of avian cellulitis from a processing plant located in the State of Goiás in order to analyze antimicrobial resistance by antibiogram test and to detect resistance genes by polymerase chain reaction. A total of 25 samples of avian cellulitis lesions were analyzed, from which 30 bacterial strains were isolated. There were eleven (44% strains of Escherichia coli, nine (36% strains of Staphylococcus epidermidis, seven (28% strains of Proteus mirabilis and three (12% strains of Manheimiahaemolytica. The antibiogram test showed that all strains were resistant to at least one antimicrobial. The gene of antimicrobial resistance tetB was detected in E. coli, S. epidermidis and P. mirabilis strains, and was the most frequently observed gene. The gene of antimicrobial resistance Sul1 was detected in all bacterial species, while tetA was found in E. coli and S. epidermidis strains, SHV in E. coli strains, S. epidermidis and P. mirabilis,and cat1 in one P. mirabilis strain. The results suggest a potential public health hazard due to the ability of these microorganisms to transmit antimicrobial resistancegenes to other microorganisms present in the intestinal tract of humans and animals, which may affect clinical-medical usage of these drugs.

  1. Degradation of 2,4-dinitroanisole (DNAN) by metabolic cooperative activity of Pseudomonas sp. strain FK357and Rhodococcus imtechensis strain RKJ300.

    Science.gov (United States)

    Khan, Fazlurrahman; Pal, Deepika; Ghosh, Anuradha; Cameotra, Swaranjit Singh

    2013-11-01

    2,4-Dinitroanisole (DNAN) is an insensitive explosive ingredient used by many defense agencies as a replacement for 2,4,6-trinitrotoluene. Although the biotransformation of DNAN under anaerobic condition has been reported, aerobic microbial degradation pathway has not been elucidated. An n-methyl-4-nitroaniline degrading bacterium Pseudomonas sp. strain FK357 transformed DNAN into 2,4-dinitrophenol (2,4-DNP) as an end product. Interestingly, when strain FK357 was co-cultured with a 2,4-DNP degrading Rhodococcus imtechensis strain RKJ300, complete and high rate of DNAN degradation was observed with no accumulation of intermediates. Enzyme assay using cell extracts of strain FK357 demonstrated that O-demethylation reaction is the first step of DNAN degradation with formation of 2,4-DNP and formaldehyde as intermediates. Subsequently, 2,4-DNP was degraded by strain RKJ300 via the formation of hydride-Meisenheimer complex. The present study clearly demonstrates that complete degradation of DNAN occurs as a result of the metabolic cooperative activity of two members within a bacterial consortium.

  2. Isolation and identification of a pyrene-degrading bacterial strain in seawater and its pyrene biodegradation features%1株分离自海水中芘降解菌的鉴定及其降解特性研究

    Institute of Scientific and Technical Information of China (English)

    王静; 邱金泉; 张雨山; 杨波; 张晓青; 苗英霞; 张爱君; 张辉

    2011-01-01

    以芘为唯一碳源,对采自于天津港石油污染区的海水和土壤样品进行富集培养,分离到1株芘降解菌,经显微形态观察、生理生化鉴定、16S rRNA基因序列的比对及系统发育进化的分析,确定该菌株为施氏假单孢菌Pseudomonas stutzeri,并采用室内培养方法,对其进行了芘降解性能的测定及降解途径的分析.结果表明,该菌株在以芘为唯一碳源的无机盐培养基中培养36 h后,对芘的降解率达到96%以上.该菌株具有邻二酚2,3-双加氧酶活力,且酶活力随芘质量浓度的增高而提高,可以确定该菌株是以邻苯二酚为中间代谢物对芘进行降解的.%Polycyclic aromatic hydrocarbons (PAHs) are common organic pollutants widely distributed in the natural environment. Their easiness to accumulate and be delivered by food chain and their carcinogenic and mutagenic features make them extremely harmful to human health and ecological environment. A large amount of wastewater containing PAHs flows into the ocean at last, which makes the study of PAHs pollution control of the sea a critical issue. But, due to the particularity and complexity of the marine environment, many regular physical and chemical approaches do not work. In recent years, remediation of the polluted environment with microbial degradation is considered to be the most efficient way to control PAHs contamination. Thus the study on PAHs microbial degradation has become one of the most active areas in marine environmental pollution research, and acquisition of high efficient PAHs-degradating bacteria is the key for biodegradation and bioremediation of PAHs.A pyrene-degrading bacterial strain B5 was separated through selectively enriched culture from the oilcontaminated sample from the Tianjin port. Its characteristics of growth and pyrene degradation ability are studied. This strain B5 grew very fast in culture solution with pyrene as the sole carbon source. The growth entered into logarithm

  3. Functional redundancy in phenol and toluene degradation in Pseudomonas stutzeri strains isolated from the Baltic Sea.

    Science.gov (United States)

    Heinaru, Eeva; Naanuri, Eve; Grünbach, Maarja; Jõesaar, Merike; Heinaru, Ain

    2016-09-01

    In the present study we describe functional redundancy of bacterial multicomponent monooxygenases (toluene monooxygenase (TMO) and toluene/xylene monooxygenase (XylAM) of TOL pathway) and cooperative genetic regulation at the expression of the respective catabolic operons by touR and xylR encoded regulatory circuits in five phenol- and toluene-degrading Pseudomonas stutzeri strains. In these strains both toluene degradation pathways (TMO and Xyl) are active and induced by toluene and phenol. The whole genome sequence of the representative strain 2A20 revealed the presence of complete TMO- and Xyl-upper pathway operons together with two sets of lower catechol meta pathway operons, as well as phenol-degrading operon in a single 292,430bp contig. The much lower GC content and analysis of the predicted ORFs refer to the plasmid origin of the approximately 130kb region of this contig, containing the xyl, phe and tou genes. The deduced amino acid sequences of the TMO, XylA and the large subunit of phenol monooxygenase (LmPH) show 98-100% identity with the respective gene products of the strain Pseudomonas sp. OX1. In both strains 2A20 and OX1 the meta-cleavage pathways for catechol degradation are coded by two redundant operons (phe and xyl). We show that in the strain 2A20 TouR and XylR are activated by different effector molecules, phenol and toluene, respectively, and they both control transcription of the xyl upper, tou (TMO) and phe catabolic operons. Although the growth parameters of redundant strains did not show advantage at toluene biodegradation, the functional redundancy could provide better flexibility to the bacteria in environmental conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Phagosomal degradation increases TLR access to bacterial ligands and enhances macrophage sensitivity to bacteria

    Science.gov (United States)

    Wolf, Andrea J.; Arruda, Andrea; Reyes, Christopher N.; Kaplan, Amber T.; Shimada, Takahiro; Shimada, Kenichi; Arditi, Moshe; Liu, George; Underhill, David M.

    2011-01-01

    Signaling by innate immune receptors initiates and orchestrates the overall immune responses to infection. Macrophage receptors recognizing pathogens can be broadly grouped into surface receptors and receptors restricted to intracellular compartments, such as phagosomes and the cytoplasm. There is an expectation that ingestion and degradation of microorganisms by phagocytes contributes to activation of intracellular innate receptors, although direct demonstrations of this are rare and many model ligands are studied in soluble form, outside of their microbial context. By comparing a wild-type strain of Staphylococcus aureus and a lysozyme-sensitive mutant, we have been able to directly address the role of degradation of live bacteria by mouse macrophages in determining the overall innate cellular inflammatory response. Our investigations revealed a biphasic response to S. aureus that consisted of an initial signal resulting from the engagement of surface TLR2, followed by a later, second wave on inflammatory gene induction. This second wave of inflammatory signaling was dependent on and correlated with the timing of bacterial degradation in phagosomes. We found that TLR2 signaling followed by TLR2/TLR9 signaling enhanced sensitivity to small numbers of bacteria. We further found that treating wild-type bacteria with the peptidoglycan synthesis-inhibiting antibiotic vancomycin made S. aureus more susceptible to degradation and resulted in increased inflammatory responses, similar to those observed for mutant degradation-sensitive bacteria. PMID:22031762

  5. Bacterial assisted degradation of chlorpyrifos: The key role of environmental conditions, trace metals and organic solvents.

    Science.gov (United States)

    Khalid, Saira; Hashmi, Imran; Khan, Sher Jamal

    2016-03-01

    Wastewater from pesticide industries, agricultural or surface runoff containing pesticides and their residues has adverse environmental impacts. Present study demonstrates effect of petrochemicals and trace metals on chlorpyrifos (CP) biotransformation often released in wastewater of agrochemical industry. Biodegradation was investigated using bacterial strain Pseudomonas kilonensis SRK1 isolated from wastewater spiked with CP. Optimal environmental conditions for CP removal were CFU (306 × 10(6)), pH (8); initial CP concentration (150 mg/L) and glucose as additional carbon source. Among various organic solvents (petrochemicals) used in this study toluene has stimulatory effect on CP degradation process using SRK1, contrary to this benzene and phenol negatively inhibited degradation process. Application of metal ions (Cu (II), Fe (II) Zn (II) at low concentration (1 mg/L) took part in biochemical reaction and positively stimulated CP degradation process. Metal ions at high concentrations have inhibitory effect on degradation process. A first order growth model was shown to fit the data. It could be concluded that both type and concentration of metal ions and petrochemicals can affect CP degradation process.

  6. Metagenomic data of free cyanide and thiocyanate degrading bacterial communities

    Directory of Open Access Journals (Sweden)

    Lukhanyo Mekuto

    2017-08-01

    Full Text Available The data presented in this article contains the bacterial community structure of the free cyanide (CN- and thiocyanate (SCN- degrading organisms that were isolated from electroplating wastewater and synthetic SCN- containing wastewater. PCR amplification of the 16S rRNA V1-V3 regions was undertaken using the 27F and 518R oligonucleotide primers following the metacommunity DNA extraction procedure. The PCR amplicons were processed using the illumina® reaction kits as per manufacturer׳s instruction and sequenced using the illumina® MiSeq-2000, using the MiSeq V3 kit. The data was processed using bioinformatics tools such as QIIME and the raw sequence files are available via NCBI׳s Sequence Read Archive (SRA database.

  7. In silico comparison of bacterial strains using mutual information

    Indian Academy of Sciences (India)

    D Swati

    2007-09-01

    Fast-sequencing throughput methods have increased the number of completely sequenced bacterial genomes to about 400 by December 2006, with the number increasing rapidly. These include several strains. In silico methods of comparative genomics are of use in categorizing and phylogenetically sorting these bacteria. Various word-based tools have been used for quantifying the similarities and differences between entire genomes. The simple di-nucleotide frequency comparison, codon specificity and k-mer repeat detection are among some of the well-known methods. In this paper, we show that the Mutual Information function, which is a measure of correlations and a concept from Information Theory, is very effective in determining the similarities and differences among genome sequences of various strains of bacteria such as the plant pathogen Xylella fastidiosa, marine Cyanobacteria Prochlorococcus marinus or animal and human pathogens such as species of Ehrlichia and Legionella. The short-range three-base periodicity, small sequence repeats and long-range correlations taken together constitute a genome signature that can be used as a technique for identifying new bacterial strains with the help of strains already catalogued in the database. There have been several applications of using the Mutual Information function as a measure of correlations in genomics but this is the first whole genome analysis done to detect strain similarities and differences.

  8. Technological Potential of Lactobacillus Strains Isolated from Fermented Green Olives: In Vitro Studies with Emphasis on Oleuropein-Degrading Capability

    Directory of Open Access Journals (Sweden)

    Massimo Iorizzo

    2016-01-01

    Full Text Available Technological properties of two strains of Lactobacillus plantarum (B3 and B11 and one of Lactobacillus pentosus (B4, previously isolated from natural fermented green olives, have been studied in vitro. Acidifying ability, salt, temperature, and pH tolerances of all strains were found in the range reported for similar strains produced in Italy and optimal growth conditions were found to be 6.0–8.0 pH, 15–30°C temperature, and less than 6% NaCl. Moreover, all strains showed very good tolerance to common olive phenol content (0.3% total phenol and high oleuropein-degrading capability. It was found that medium composition affected the bacterial oleuropein degradation. B11 strain grown in a nutrient-rich medium showed a lower oleuropein-degrading action than when it was cultivated in nutrient-poor medium. Furthermore, enzymatic activity assays revealed that oleuropein depletion did not correspond to an increase of hydroxytyrosol, evidencing that bacterial strains could efficiently degrade oleuropein via a mechanism different from hydrolysis.

  9. Bacterial strain changes during chronic otitis media surgery.

    Science.gov (United States)

    Kim, G J; Yoo, S; Han, S; Bu, J; Hong, Y; Kim, D-K

    2017-09-01

    Cultures obtained from pre-operative middle-ear swabs from patients with chronic otitis media have traditionally been used to guide antibiotic selection. This study investigated changes in the bacterial strains of the middle ear during chronic otitis media surgery. Pre-operative bacterial cultures of otorrhoea, and peri-operative cultures of the granulation tissue in either the middle ear or mastoid cavity, were obtained. Post-operative cultures were selectively obtained when otorrhoea developed after surgery. Bacterial growth was observed in 45.5 per cent of pre-operative cultures, 13.5 per cent of peri-operative cultures and 4.5 per cent of post-operative cultures. Methicillin-resistant Staphylococcus aureus was identified as the most common bacteria in all pre-operative (32.4 per cent), peri-operative (52.4 per cent) and post-operative (71.4 per cent) tests, and the percentage of Methicillin-resistant S aureus increased from the pre- to the post-operative period. The bacterial culture results for post-operative otorrhoea showed low agreement with those for pre-operative or peri-operative culture, and strain re-identification was required.

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

    Science.gov (United States)

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

    2012-01-01

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

  11. Degradation of Bacterial Quorum Sensing Signaling Molecules by the Microscopic Yeast Trichosporon loubieri Isolated from Tropical Wetland Waters

    Directory of Open Access Journals (Sweden)

    Cheng-Siang Wong

    2013-09-01

    Full Text Available Proteobacteria produce N-acylhomoserine lactones as signaling molecules, which will bind to their cognate receptor and activate quorum sensing-mediated phenotypes in a population-dependent manner. Although quorum sensing signaling molecules can be degraded by bacteria or fungi, there is no reported work on the degradation of such molecules by basidiomycetous yeast. By using a minimal growth medium containing N-3-oxohexanoylhomoserine lactone as the sole source of carbon, a wetland water sample from Malaysia was enriched for microbial strains that can degrade N-acylhomoserine lactones, and consequently, a basidiomycetous yeast strain WW1C was isolated. Morphological phenotype and molecular analyses confirmed that WW1C was a strain of Trichosporon loubieri. We showed that WW1C degraded AHLs with N-acyl side chains ranging from 4 to 10 carbons in length, with or without oxo group substitutions at the C3 position. Re-lactonisation bioassays revealed that WW1C degraded AHLs via a lactonase activity. To the best of our knowledge, this is the first report of degradation of N-acyl-homoserine lactones and utilization of N-3-oxohexanoylhomoserine as carbon and nitrogen source for growth by basidiomycetous yeast from tropical wetland water; and the degradation of bacterial quorum sensing molecules by an eukaryotic yeast.

  12. High-Throughput Screening for a Moderately Halophilic Phenol-Degrading Strain and Its Salt Tolerance Response

    Directory of Open Access Journals (Sweden)

    Zhi-Yan Lu

    2015-05-01

    Full Text Available A high-throughput screening system for moderately halophilic phenol-degrading bacteria from various habitats was developed to replace the conventional strain screening owing to its high efficiency. Bacterial enrichments were cultivated in 48 deep well microplates instead of shake flasks or tubes. Measurement of phenol concentrations was performed in 96-well microplates instead of using the conventional spectrophotometric method or high-performance liquid chromatography (HPLC. The high-throughput screening system was used to cultivate forty-three bacterial enrichments and gained a halophilic bacterial community E3 with the best phenol-degrading capability. Halomonas sp. strain 4-5 was isolated from the E3 community. Strain 4-5 was able to degrade more than 94% of the phenol (500 mg·L−1 starting concentration over a range of 3%–10% NaCl. Additionally, the strain accumulated the compatible solute, ectoine, with increasing salt concentrations. PCR detection of the functional genes suggested that the largest subunit of multicomponent phenol hydroxylase (LmPH and catechol 1,2-dioxygenase (C12O were active in the phenol degradation process.

  13. Genome Sequence of Pseudomonas sp. Strain Chol1, a Model Organism for the Degradation of Bile Salts and Other Steroid Compounds

    KAUST Repository

    Holert, Johannes

    2013-01-15

    Bacterial degradation of steroid compounds is of high ecological and biotechnological relevance. Pseudomonas sp. strain Chol1 is a model organism for studying the degradation of the steroid compound cholate. Its draft genome sequence is presented and reveals one gene cluster responsible for the metabolism of steroid compounds.

  14. [Effects of nitrogen and phosphorus fertilizer on atrazine degradation and detoxification by degrading strain HB-5].

    Science.gov (United States)

    Su, Jun; Zhu, Lu-Sheng; Li, Xu-Hua; Wang, Jun; Xie, Hui; Wang, Jin-Hua; Wang, Qi; Jia, Wen-Tao

    2010-10-01

    An atrazine-degrading strain HB-5 was used as a bacteria for biodegradation. Treatments of soil with nitrogen single, phosphate single and nitrogen phosphate together with HB-5 were carried out for degradation and eco-toxicity test; then, relationship between atrazine degradation rate and soil available nitrogen, available phosphorus were discussed. Atrazine residues were determined by HPLC; available nitrogen was determined with alkaline hydrolysis diffusion method; available phosphorus was determined with 0.5 mol/L-NaHCO3 extraction and molybdenum stibium anti-color method, and toxicity test was carried out with micronucleus test of Vicia faba root tip cells. The results showed that: After separately or together application, nitrogenous and phosphorous fertilizers could significantly accelerate atrazine degradation than soil with HB-5 only. On day 5, the order of atrazine degradation was ANP > AP > AN > A; 7 days later, no statistically significant differences were found between treatments. The available nitrogen and phosphorus level in soil reduced as the degradation rate increased in the soil. The soil of eco-toxicity test results indicated that the eco-toxicity significantly reduced with the degradation of atrazine by HB-5, and the eco-toxicity on treatments of soil with fertilizer were all below the treatments without fertilizer. On day 5, the order of eco-toxicity was ANP atrazine degradation in soil but also could reduce the soil eco-toxicity effects that atrazine caused. All these results could be keystone of atrazine pollution remediation in contaminated soil in the future.

  15. Bacterial degradation of recalcitrant PAHs: metabolic studies and application to pyrene degradation in a freshwater sediment

    Energy Technology Data Exchange (ETDEWEB)

    Jouanneau, Y.; Demaneche, S.; Meyer, Ch.; Willison, J.C. [CEA-Grenoble, UMR 5092 CNRS-CEA-UJF, 38 - Grenoble (France)

    2005-07-01

    Cost-effective bio-remediation strategies have been proposed to remove toxic chemicals, including polycyclic aromatic hydrocarbons (PAHs), from contaminated sites. However, the efficiency of these strategies is often limited, due to the resistance of certain chemicals to microbial degradation. Our studies deal with the biodegradation of four-ring PAHs using two recently isolated bacteria, Mycobacterium strain 6PY1, which can mineralize pyrene and phenanthrene, and Sphingomonas strain CHY-1, which mineralizes chrysene and various three-ring PAHs. The metabolic pathways for the biodegradation of PAHs have been investigated using GC-MS to identify and assay metabolites. Also, several enzymes involved in PAH catabolism have been identified by a combination of proteomic and genetic approaches. In Mycobacterium 6PY1, two ring-hydroxylating di-oxygenases which catalyze the initial attack of PAHs have been overproduced in E. coli, isolated and characterized. The selectivity of the two enzymes showed marked differences, since one di-oxygenase preferentially oxidized 2- or 3- ring PAHs whereas the other attacked pyrene and 3-ring PAHs exclusively. In Sphingomonas CHY-1, a single di-oxygenase, called PhnI, was found to convert seven PAHs, including chrysene, to the corresponding dihydro-diols. It is the first enzyme to be described which is able to attack the four-ring PAHs chrysene and benz[a]anthracene.. The fate of pyrene was examined in a sediment taken from a freshwater lake of the French Alps. Experiments were carried out in microcosms containing a layer of sediment which was spiked with {sup 14}C-pyrene. Pyrene mineralization was monitored over 61 days by measuring the {sup 14}CO{sub 2} evolved from the microcosms. Some microcosms were planted with young reeds (Phragmites australis), while other were inoculated with Mycobacterium 6PY1. P. australis reeds promoted a significant increase of pyrene degradation, which most likely resulted from a root-mediated increase of

  16. Biological treatment of tannery wastewater by using salt-tolerant bacterial strains

    Directory of Open Access Journals (Sweden)

    Sekar Sudharshan

    2008-04-01

    Full Text Available Abstract Background High salinity (1–10% w/v of tannery wastewater makes it difficult to be treated by conventional biological treatment. Salt tolerant microbes can adapt to these saline conditions and degrade the organics in saline wastewater. Results Four salt tolerant bacterial strains isolated from marine and tannery saline wastewater samples were identified as Pseudomonas aeruginosa, Bacillus flexus, Exiguobacterium homiense and Staphylococcus aureus. Growth factors of the identified strains were optimized. Tannery saline wastewater obtained from a Common Effluent Treatment Plant (CETP near Chennai (southern India was treated with pure and mixed consortia of four salt tolerant bacterial strains. Experiments with optimized conditions and varying salt content (between 2 and 10% (w/v were conducted. Salt inhibition effects on COD removal rate were noted. Comparative analysis was made by treating the tannery saline wastewater with activated sludge obtained from CETP and with natural habitat microbes present in raw tannery saline wastewater. Conclusion Salt tolerant bacterial mixed consortia showed appreciable biodegradation at all saline concentrations (2%, 4%, 6%, 8% and 10% w/v with 80% COD reduction in particular at 8% salinity level the consortia could be used as suitable working cultures for tannery saline wastewater treatment.

  17. Microbial Degradation of Chlorogenic Acid by a Sphingomonas sp. Strain.

    Science.gov (United States)

    Ma, Yuping; Wang, Xiaoyu; Nie, Xueling; Zhang, Zhan; Yang, Zongcan; Nie, Cong; Tang, Hongzhi

    2016-08-01

    In order to elucidate the metabolism of chlorogenic acid by environmental microbes, a strain of Sphingomonas sp. isolated from tobacco leaves was cultured under various conditions, and chlorogenic acid degradation and its metabolites were investigated. The strain converting chlorogenic acid was newly isolated and identified as a Sphingomonas sp. strain by 16S rRNA sequencing. The optimal conditions for growth and chlorogenic acid degradation were 37 °C and pH 7.0 with supplementation of 1.5 g/l (NH4)2SO4 as the nitrogen source and 2 g/l chlorogenic acid as the sole carbon source. The maximum chlorogenic acid tolerating capability for the strain was 5 g/l. The main metabolites were identified as caffeic acid, shikimic acid, and 3,4-dihydroxybenzoic acid based on gas chromatography-mass spectrometry analysis. The analysis reveals the biotransformation mechanism of chlorogenic acid in microbial cells isolated from the environment.

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

    Science.gov (United States)

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

    2013-10-01

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

  19. Enhanced cometabolic degradation of methyl tert-butyl ether by a Pseudomonas sp. strain grown on n-pentane

    Science.gov (United States)

    Li, S. S.; Wang, S.; Yan, W.

    2016-08-01

    When methyl tert-butyl ether (MTBE) is added as oxygenates it increases the octane number and decreases the release of nitric oxide from the incomplete combustion of reformulated gasoline. The extensive use of MTBE allowed it to be detectable as a pollutant in both ground-level and underground water worldwide. The present study focuses on the isolation and characterization of MTB-degrading microorganisms by cometabolism based on the results of growth on different carbon sources. It also focuses on the kinetic analysis and the continuous degradation of MTBE. A bacterial strain WL1 that can grow on both n-alkanes (C5-C8) and aromatics was isolated and named Pseudomonas sp. WL1 according to the 16S rDNA sequencing analysis. Strain WL1 could cometabolically degrade MTBE in the presence of n-alkanes with a desirable degradation rate. Diverse n-alkanes with different lengths of carbon chains showed significant influence on the degradation rate of MTBE and accumulation of tert-butyl alcohol (TBA). When strain WL1 cometabolically degraded MTBE in the presence of n-pentane, higher MTBE-degrading rate and lower TBA-accumulation were observed (Vmax = 38.1 nmol/min/mgprotei, Ks = 6.8 mmol/L). In the continuous degrading experiment, the removal efficiency of MTBE by Pseudomonas sp. WL1 did not show any obvious decrease after five subsequent additions.

  20. [Isolation of an anthracene-degrading strain Aspergillus fumigatus A10 and its degradation characteristics].

    Science.gov (United States)

    Qiang, Jing; Yin, Hua; Peng, Hui; Ye, Jin-Shao; Qin, Hua-Ming; He, Bao-Yan; Zhang, Na

    2009-05-15

    An anthracene-degrading strain (A10) was isolated from contaminated environment and identified as Aspergillus fumigatus. The experimental results showed that the biodegradation rate of anthracene increased with the increasing time. Between 12-84 h interval, the biodegradation performed rapidly, while after this, the increase of biodegradation rate tended to become slow, and ultimately the biodegradation rate could achieve approximately 83%. The degradatinn rate of anthracene reached 79.37% within 5 days when the initial concentration of anthracene in mineral salts medium (MSM) was 10 mg/L, the inoculum dosage was 50 g/L (wet weight) and the cell age was 36 h. The concentration of anthracene had notable influence on degradation function of strain A10 and the highest degradation rate (92.17%) was achieved when anthracene concentration was 5 mg/L. The degradation rate could maintain about 60% with initial pH of MSM in the range of 5.0-7.5, and also, the anthracene could be better broken down when the temperature was 30 degrees C and dissolved oxygen was 4.30 mg/L. Certain amount of nutrition salts promoted the biodegradation of anthracene to some extent. Addition of lactose as co-metabolic substrate most favorably accelerated degradation of anthracene by about 37.15%. The mechanism research revealed that the biodegradation by strain A10 was a dynamic process in which extracellular sorption and intracellular degradation were included. FT-IR analysis exhibited that the structure of anthracene changed with the action of microbe, generating a series of metabolites, such as aromatic acid, aromatic ketone, aromatic aldehyde with one or two benzene rings, as well as saturated hydrocarbons.

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

    Directory of Open Access Journals (Sweden)

    Brian O'Farrell

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

  2. Vibrio vulnificus Secretes an Insulin-degrading Enzyme That Promotes Bacterial Proliferation in Vivo.

    Science.gov (United States)

    Kim, In Hwang; Kim, Ik-Jung; Wen, Yancheng; Park, Na-Young; Park, Jinyoung; Lee, Keun-Woo; Koh, Ara; Lee, Ji-Hyun; Koo, Seung-Hoi; Kim, Kun-Soo

    2015-07-24

    We describe a novel insulin-degrading enzyme, SidC, that contributes to the proliferation of the human bacterial pathogen Vibrio vulnificus in a mouse model. SidC is phylogenetically distinct from other known insulin-degrading enzymes and is expressed and secreted specifically during host infection. Purified SidC causes a significant decrease in serum insulin levels and an increase in blood glucose levels in mice. A comparison of mice infected with wild type V. vulnificus or an isogenic sidC-deletion strain showed that wild type bacteria proliferated to higher levels. Additionally, hyperglycemia leads to increased proliferation of V. vulnificus in diabetic mice. Consistent with these observations, the sid operon was up-regulated in response to low glucose levels through binding of the cAMP-receptor protein (CRP) complex to a region upstream of the operon. We conclude that glucose levels are important for the survival of V. vulnificus in the host, and that this pathogen uses SidC to actively manipulate host endocrine signals, making the host environment more favorable for bacterial survival and growth.

  3. Characterization of Bacterial Strains Isolated from a Novel Seawater-based Retting Treatment of Hemp

    Institute of Scientific and Technical Information of China (English)

    ZHU Run-ye; CHEN Jian-yong; FENG Xin-xing; ZHANG Jian-chun

    2008-01-01

    Cultivable bacteria were isolated from seawater-based retting treatment of hemp, in which three of purified strains (SW - 1, SW - 2, and S - SW1) produced relatively high levels of pectinase activities, and also produced mannanases and xylanases.PCR - based entebacterial repetitive intergenic consensus primers (ERIC- PCR) were employed for fingerprinting DNA of the bacterial strains.The ERIC - PCR fingerprints of stains SW- 1, SW -1, and S -SW1 were found to be different, and should be further identified for each isolate.Strains SW - 1 and SW - 2 were identified as Stenotrophomnas maltophilia, while strain S - SW1 was assigned to Ochrobactrum anthropi by BIOLOG system.These two species represented rhizosphere bacterial genera, and possibly were introduced by the hemp plants.These organisms seemed potentially capable of producing pectinase and hemicellulase, and thus effectively degrading the gum substances in the seawater retting.This research could be helpful for improving a novel seawater-based retting treatment of hemp.

  4. Halotolerance, ligninase production and herbicide degradation ability of basidiomycetes strains

    Directory of Open Access Journals (Sweden)

    R.L. Arakaki

    2013-12-01

    Full Text Available Fungi have been recently recognized as organisms able to grow in presence of high salt concentration with halophilic and halotolerance properties and their ligninolytic enzyme complex have an unspecific action enabling their use to degradation of a number of xenobiotic compounds. In this work, both the effect of salt and polyols on growth of the basidiomycetes strains, on their ability to produce ligninolytic enzyme and diuron degradation were evaluated. Results showed that the presence of NaCl in the culture medium affected fungal specimens in different ways. Seven out of ten tested strains had growth inhibited by salt while Dacryopinax elegans SXS323, Polyporus sp MCA128 and Datronia stereoides MCA167 fungi exhibited higher biomass production in medium containing 0.5 and 0.6 mol.L-1 of NaCl, suggesting to be halotolerant. Polyols such as glycerol and mannitol added into the culture media improved the biomass and ligninases production by D. elegans but the fungus did not reveal consumption of these polyols from media. This fungus degraded diuron in medium control, in presence of NaCl as well as polyols, produced MnP, LiP and laccase.

  5. Antimicrobial effect against different bacterial strains and bacterial adaptation to essential oils used as feed additives

    OpenAIRE

    Melo, Antonio Diego Brandão; Amaral, Amanda Figueiredo; Schaefer, Gustavo; Luciano, Fernando Bittencourt; Andrade,Carla de; Costa, Leandro Batista; Rostagno, Marcos Horácio

    2015-01-01

    The aim of this study was to evaluate the antimicrobial activity and determine the minimum bactericidal concentration (MBC) of the essential oils derived from Origanum vulgare (oregano), Melaleuca alternifolia (tea tree), Cinnamomum cassia (cassia), and Thymus vulgaris (white thyme) against Salmonella Typhimurium, Salmonella Enteritidis, Escherichia coli, Staphylococcus aureus and Enterococcus faecalis. The study also investigated the ability of these different bacterial strains to develop ad...

  6. Ciclohexadespipeptide beauvericin degradation by different strains of Saccharomyces cerevisiae.

    Science.gov (United States)

    Meca, G; Zhou, T; Li, X Z; Ritieni, A; Mañes, J

    2013-09-01

    The interaction between the mycotoxin beauvericin (BEA) and 9 yeast strains of Saccharomyces cerevisiae named LO9, YE-2, YE5, YE-6, YE-4, A34, A17, A42 and A08 was studied. The biological degradations were carried out under aerobic conditions in the liquid medium of Potato Dextrose Broth (PDB) at 25°C for 48 h and in a food/feed system composed of corn flour at 37°C for 3 days, respectively. BEA present in fermented medium and corn flour was determined using liquid chromatography coupled to the mass spectrometry detector in tandem (LC-MS/MS) and the BEA degradation products produced during the fermentations were determined using the technique of the liquid chromatography coupled to a linear ion trap (LIT). Results showed that the S. cerevisiae strains reduced meanly the concentration of the BEA present in PDB by 86.2% and in a food system by 71.1%. All the S. cerevisiae strains used in this study showed a significant BEA reduction during the fermentation process employed.

  7. Cometabolic Degradation of Naproxen by Planococcus sp. Strain S5.

    Science.gov (United States)

    Domaradzka, Dorota; Guzik, Urszula; Hupert-Kocurek, Katarzyna; Wojcieszyńska, Danuta

    Naproxen is a non-steroidal anti-inflammatory drug frequently detected in the influent and effluent of sewage treatment plants. The Gram-positive strain Planococcus sp. S5 was able to remove approximately 30 % of naproxen after 35 days of incubation in monosubstrate culture. Under cometabolic conditions, with glucose or phenol as a growth substrate, the degradation efficiency of S5 increased. During 35 days of incubation, 75.14 ± 1.71 % and 86.27 ± 2.09 % of naproxen was degraded in the presence of glucose and phenol, respectively. The highest rate of naproxen degradation observed in the presence of phenol may be connected with the fact that phenol is known to induce enzymes responsible for aromatic ring cleavage. The activity of phenol monooxygenase, naphthalene monooxygenase, and hydroxyquinol 1,2-dioxygenase was indicated in Planococcus sp. S5 culture with glucose or phenol as a growth substrate. It is suggested that these enzymes may be engaged in naproxen degradation.

  8. Novel bacterial strains for the removal of microcystins from drinking water.

    Science.gov (United States)

    Lawton, L A; Welgamage, A; Manage, P M; Edwards, C

    2011-01-01

    Microcystins (MC) and nodularin (NOD) are common contaminants of drinking water around the world and due to their significant health impact it is important to explore suitable approaches for their removal. Unfortunately, these toxins are not always removed by conventional water treatments. One of the most exciting areas that hold promise for a successful and cost effective solution is bioremediation of microcystins. Recent work resulted in successful isolation and characterisation of 10 novel bacterial strains (Rhodococcus sp., Arthrobacter spp. and Brevibacterium sp.) capable of metabolizing microcystin-LR (MC-LR) in a Biolog MT2 assay. The work presented here aims to further investigate and evaluate the metabolism and the degradation of multiple microcystins (MC-LR, MC-LF, MC-LY, MC-LW and MC-RR) and nodularin by the bacterial isolates. A total of five bacterial isolates representing the three genera were evaluated using Biolog MT2 assay with a range of MCs where they all demonstrated an overall metabolism on all MCs and NOD. Subsequently, the results were confirmed by observing the degradation of the range of toxins in a separate batch experiment.

  9. Isolation and characterization of a Sphingomonas sp. strain F-7 degrading fenvalerate and its use in bioremediation of contaminated soil.

    Science.gov (United States)

    Yu, Fang B; Shan, Sheng D; Luo, Lin P; Guan, Li B; Qin, Hua

    2013-01-01

    A fenvalerate-degrading bacterial strain F-7 was isolated from long-term contaminated sludge. Based on morphological, physiological and biochemical characterization, and phylogenetic analysis of 16S rRNA gene sequence, strain F-7 was identified as Sphingomonas sp. The bacterium could utilize fenvalerate as the sole source of carbon. An amount measuring 100 mg L(-1) fenvalerate was completely degraded within 72 h and 3-phenoxybenzoic acid (3-PBA) was detected as a major metabolite. The result indicates that S. sp. F-7 might metabolize fenvalerate by hydrolysis of carboxylester linkage. It was capable of degrading permethrin, fenpropathrin, beta-cypermethrin, cyhalothrin, deltamethrin, bifenthrin and 3-PBA. Further studies demonstrated that the strain was multi-resistant to heavy metals and antibiotics. In addition, degradative enzymes involved were confirmed as intracellular distributed and constitutively expressed. Furthermore, application of the strain was found to accelerate the removal of fenvalerate in soil. This is the first report of fenvalerate degrading strain isolated from S. sp. These results might help with future research in better understanding of pyrethroid biodegradation and highlight S. sp. F-7 might have potential for practical application in bioremediation of fenvalerate-contaminated sites.

  10. Molecular analysis of phenol-degrading microbial strains.

    Science.gov (United States)

    Manasiev, Jordan; Gerginova, Maria; Yemendzhiev, Hyusein; Peneva, Nadejda; Alexieva, Zlatka

    2008-01-01

    In an attempt to estimate the occurrence of phenol hydroxylase-related gene sequences we performed a dot blot hybridization assay with DNA from phenol utilizing Trichosporon cutaneum R57 strain NBIMCC 2414 and microbial isolates from different wastewaters. The used oligonucletides were homologous to the 5'-end of TORPHD locus (NCBI)-coding phenol hydroxylase in Trichosporon cutaneum ATCC 46490 and to the 5'-end of TORCCMLE locus (NCBI)-coding cis,cis-muconate-lactonizing enzyme in Trichosporon cutaneum ATCC 58094. Two microbial strains, Escherichia coli JM 109 and Lactobacillus acidophilus ATCC 4356, incapable to degrade phenol were used as negative controls. We established the presence of hybridization with both used oligonucleotide probes in T. cutaneum R57 and T. cutaneum ATCC 46490 yeast strains. The experiments implemented with microbial isolates obtained from three industrialized areas in Bulgaria showed that 7 of them may carry sequences hybridizing with a phenol hydroxylase oligonucleotide probe. A subsequent hybridization test for the cis,cis-muconate-lactonizing enzyme showed that only 3 of them displayed a positive signal. Lactobacillus acidophilus ATCC 4356 and Escherichia coli JM 109 strains' DNA used as negative controls in the experiments did not reveal any sequence similarity to the both applied oligonucleotides. The partial nucleotide sequences of 16S rDNAs of the isolated strains C1 and K1 obtained as PCR products were determined and sequenced. A comparison of these nucleotide sequences with similar sequences in NCBI Data Bank indicated that both C1 and K1 strains are closely related to the genera Acinetobacter and Burkholderia.

  11. Monocyclic aromatic hydrocarbon degradation by Rhodococcus sp. strain DK17.

    Science.gov (United States)

    Kim, Dockyu; Kim, Young-Soo; Kim, Seong-Ki; Kim, Si Wouk; Zylstra, Gerben J; Kim, Young Min; Kim, Eungbin

    2002-07-01

    Rhodococcus sp. strain DK17 was isolated from soil and analyzed for the ability to grow on o-xylene as the sole carbon and energy source. Although DK17 cannot grow on m- and p-xylene, it is capable of growth on benzene, phenol, toluene, ethylbenzene, isopropylbenzene, and other alkylbenzene isomers. One UV-generated mutant strain, DK176, simultaneously lost the ability to grow on o-xylene, ethylbenzene, isopropylbenzene, toluene, and benzene, although it could still grow on phenol. The mutant strain was also unable to oxidize indole to indigo following growth in the presence of o-xylene. This observation suggests the loss of an oxygenase that is involved in the initial oxidation of the (alkyl)benzenes tested. Another mutant strain, DK180, isolated for the inability to grow on o-xylene, retained the ability to grow on benzene but was unable to grow on alkylbenzenes due to loss of a meta-cleavage dioxygenase needed for metabolism of methyl-substituted catechols. Further experiments showed that DK180 as well as the wild-type strain DK17 have an ortho-cleavage pathway which is specifically induced by benzene but not by o-xylene. These results indicate that DK17 possesses two different ring-cleavage pathways for the degradation of aromatic compounds, although the initial oxidation reactions may be catalyzed by a common oxygenase. Gas chromatography-mass spectrometry and 300-MHz proton nuclear magnetic resonance spectrometry clearly show that DK180 accumulates 3,4-dimethylcatechol from o-xylene and both 3- and 4-methylcatechol from toluene. This means that there are two initial routes of oxidation of toluene by the strain. Pulsed-field gel electrophoresis analysis demonstrated the presence of two large megaplasmids in the wild-type strain DK17, one of which (pDK2) was lost in the mutant strain DK176. Since several other independently derived mutant strains unable to grow on alkylbenzenes are also missing pDK2, the genes encoding the initial steps in alkylbenzene

  12. Production and Reutilization of Fluorescent Dissolved Organic Matter by a Marine Bacterial Strain, Alteromonas macleodii

    Science.gov (United States)

    Goto, Shuji; Tada, Yuya; Suzuki, Koji; Yamashita, Youhei

    2017-01-01

    The recalcitrant fraction of marine dissolved organic matter (DOM) plays an important role in carbon storage on the earth’s surface. Bacterial production of recalcitrant DOM (RDOM) has been proposed as a carbon sequestration process. It is still unclear whether bacterial physiology can affect RDOM production. In this study, we conducted a batch culture using the marine bacterial isolate Alteromonas macleodii, a ubiquitous gammaproteobacterium, to evaluate the linkage between bacterial growth and DOM production. Glucose (1 mmol C L-1) was used as the sole carbon source, and the bacterial number, the DOM concentration in terms of carbon, and the excitation–emission matrices (EEMs) of DOM were monitored during the 168-h incubation. The incubation period was partitioned into the exponential growth (0–24 h) and stationary phases (24–168 h) based on the growth curve. Although the DOM concentration decreased during the exponential growth phase due to glucose consumption, it remained stable during the stationary phase, corresponding to approximately 4% of the initial glucose in terms of carbon. Distinct fluorophores were not evident in the EEMs at the beginning of the incubation, but DOM produced by the strain exhibited five fluorescent peaks during exponential growth. Two fluorescent peaks were similar to protein-like fluorophores, while the others could be categorized as humic-like fluorophores. All fluorophores increased during the exponential growth phase. The tryptophan-like fluorophore decreased during the stationary phase, suggesting that the strain reused the large exopolymer. The tyrosine-like fluorophore seemed to be stable during the stationary phase, implying that the production of tyrosine-containing small peptides through the degradation of exopolymers was correlated with the reutilization of the tyrosine-like fluorophore. Two humic-like fluorophores that showed emission maxima at the longer wavelength (525 nm) increased during the stationary phase

  13. Strains of the soil fungus Mortierella show different degradation potentials for the phenylurea herbicide diuron.

    Science.gov (United States)

    Ellegaard-Jensen, Lea; Aamand, Jens; Kragelund, Birthe B; Johnsen, Anders H; Rosendahl, Søren

    2013-11-01

    Microbial pesticide degradation studies have until now mainly focused on bacteria, although fungi have also been shown to degrade pesticides. In this study we clarify the background for the ability of the common soil fungus Mortierella to degrade the phenylurea herbicide diuron. Diuron degradation potentials of five Mortierella strains were compared, and the role of carbon and nitrogen for the degradation process was investigated. Results showed that the ability to degrade diuron varied greatly among the Mortierella strains tested, and the strains able to degrade diuron were closely related. Degradation of diuron was fastest in carbon and nitrogen rich media while suboptimal nutrient levels restricted degradation, making it unlikely that Mortierella utilize diuron as carbon or nitrogen sources. Degradation kinetics showed that diuron degradation was followed by formation of the metabolites 1-(3,4-dichlorophenyl)-3-methylurea, 1-(3,4-dichlorophenyl)urea and an hitherto unknown metabolite suggested to be 1-(3,4-dichlorophenyl)-3-methylideneurea.

  14. Identification of Two Chlorpyrifos-degrading Strains and the Effect of Bacterial Fermentation on Seed Germination of Radish%两株毒死蜱降解细菌菌株鉴定及对萝卜种子萌发的影响

    Institute of Scientific and Technical Information of China (English)

    任艳; 张新建; 李红梅; 黄玉杰; 李纪顺; 杨合同

    2011-01-01

    鉴定两株有较强降解毒死蜱能力的菌株N16和N432,并初步探讨此两株细菌菌液对萝卜种子萌发的影响.通过对其形态、生理生化特征及16S rDNA的分析,进行初步鉴定;以不同浓度的菌液浸泡萝卜种,之后于25℃下培养,测定发芽势、发芽率、发芽指数、活力指数.通过形态特征及序列分析,这两株菌均为琼氏不动杆菌属(Acinetobacter junii).N16细菌原液对萝卜种子发芽率、发芽指数均高于对照组,N432作用完全相反.菌株N16对萝卜种子的萌发具有促进作用,这种促进作用随着培养液的稀释,呈现逐渐降低的趋势.而菌株N432则对种子的萌发具有抑制作用,并且这种抑制作用随着培养液的稀释呈现减弱趋势.%Two bacterial strains N16, N432 which could degrade chlorpyrifos were identified, and the effect of the fermentation liquid from the strains on sprout and seeding of radish was studied. The strains were identified based on the morphological, physiological, biochemical characteristic and 16S rDNA sequences. The radish seed treated with the fermentation liquid at 251 were cultures, and then germination energy, germination rate, germination index, vigor index were measured. It is showed that N16, N432 were identified as Acinetobacter junii according to the morphological characteristic and sequencing. Germination energy, germination rate, germination index, vigor index of radish seeds pretreated with pure bacteria liquid of N16 were higher than control, but they were inhibited by the N432. Germination rate and germination index were promoted by the liquid culture of N16, but they were inhibited by the liquid culture of N432. And the effects including inhibition of N432 and enhancement of N16 would be weakened when their liquid cultures were diluted.

  15. In situ degradation of phenol and promotion of plant growth in contaminated environments by a single Pseudomonas aeruginosa strain.

    Science.gov (United States)

    Wang, Yujing; Song, Jing; Zhao, Wei; He, Xiaoli; Chen, Jun; Xiao, Ming

    2011-08-15

    For bioremediation of contaminated environments, a bacterial strain, SZH16, was isolated and found to reduce phenol concentration in a selective medium. Using the reaction vessel containing the soil mixed with phenol and bacteria, we found that the single strain degraded efficiently the phenol level in soil samples. The strain was identified as Pseudomonas aeruginosa on the basis of biochemical tests and by comparison of 16S rDNA sequences, and phosphate solubilization and IAA production were not observed in the strain. Simultaneous examination of the role of strain SZH16 in the plant growth and phenol biodegradation was performed. Results showed that inoculation of the single strain in the phenol-spiked soil resulted in corn growth promotion and in situ phenol degradation and the increase in plant biomass correlated with the decrease in phenol content. Colonization experiments showed that the population of the SZH16 strain remained relatively constant. All these findings indicated that the corn growth promotion might be due to reduction in phytotoxicity, a result of phenol biodegradation by the single strain SZH16. Furthermore, the strain was found to stimulate corn growth and reduce phenol concentration simultaneously in phenol-containing water, and even historically contaminated field soils. It is attractive for environment remediation and agronomic applications. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Comparative bacterial degradation and detoxification of model and kraft lignin from pulp paper wastewater and its metabolites

    Science.gov (United States)

    Abhishek, Amar; Dwivedi, Ashish; Tandan, Neeraj; Kumar, Urwashi

    2015-05-01

    Continuous discharge of lignin containing colored wastewater from pulp paper mill into the environment has resulted in building up their high level in various aquatic systems. In this study, the chemical texture of kraft lignin in terms of pollution parameters (COD, TOC, BOD, etc.) was quite different and approximately twofold higher as compared to model lignin at same optical density (OD 3.7 at 465 nm) and lignin content (2000 mg/L). For comparative bacterial degradation and detoxification of model and kraft lignin two bacteria Citrobacter freundii and Serratia marcescens were isolated, screened and applied in axenic and mixed condition. Bacterial mixed culture was found to decolorize 87 and 70 % model and kraft lignin (2000 mg/L), respectively; whereas, axenic culture Citrobacter freundii and Serratia marcescens decolorized 64, 60 % model and 50, 55 % kraft lignin, respectively, at optimized condition (34 °C, pH 8.2, 140 rpm). In addition, the mixed bacterial culture also showed the removal of 76, 61 % TOC; 80, 67 % COD and 87, 65 % lignin from model and kraft lignin, respectively. High pollution parameters (like TOC, COD, BOD, sulphate) and toxic chemicals slow down the degradation of kraft lignin as compared to model lignin. The comparative GC-MS analysis has suggested that the interspecies collaboration, i.e., each bacterial strain in culture medium has cumulative enhancing effect on growth, and degradation of lignin rather than inhibition. Furthermore, toxicity evaluation on human keratinocyte cell line after bacterial treatment has supported the degradation and detoxification of model and kraft lignin.

  17. Dispersal networks for enhancing bacterial degradation in heterogeneous environments

    Energy Technology Data Exchange (ETDEWEB)

    Banitz, Thomas, E-mail: thomas.banitz@ufz.de [Department of Ecological Modelling, UFZ - Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig (Germany); Wick, Lukas Y.; Fetzer, Ingo [Department of Environmental Microbiology, UFZ - Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig (Germany); Frank, Karin [Department of Ecological Modelling, UFZ - Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig (Germany); Harms, Hauke [Department of Environmental Microbiology, UFZ - Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig (Germany); Johst, Karin [Department of Ecological Modelling, UFZ - Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig (Germany)

    2011-10-15

    Successful biodegradation of organic soil pollutants depends on their bioavailability to catabolically active microorganisms. In particular, environmental heterogeneities often limit bacterial access to pollutants. Experimental and modelling studies revealed that fungal networks can facilitate bacterial dispersal and may thereby improve pollutant bioavailability. Here, we investigate the influence of such bacterial dispersal networks on biodegradation performance under spatially heterogeneous abiotic conditions using a process-based simulation model. To match typical situations in polluted soils, two types of abiotic conditions are studied: heterogeneous bacterial dispersal conditions and heterogeneous initial resource distributions. The model predicts that networks facilitating bacterial dispersal can enhance biodegradation performance for a wide range of these conditions. Additionally, the time horizon over which this performance is assessed and the network's spatial configuration are key factors determining the degree of biodegradation improvement. Our results support the idea of stimulating the establishment of fungal mycelia for enhanced bioremediation of polluted soils. - Highlights: > Bacterial dispersal networks can considerably improve biodegradation performance. > They facilitate bacterial access to dispersal-limited areas and remote resources. > Abiotic conditions, time horizon and network structure govern the improvements. > Stimulating the establishment of fungal mycelia promises enhanced soil remediation. - Simulation modelling demonstrates that fungus-mediated bacterial dispersal can considerably improve the bioavailability of organic pollutants under spatially heterogeneous abiotic conditions typical for water-unsaturated soils.

  18. Degradation of linuron in soil by two fungal strains

    Directory of Open Access Journals (Sweden)

    Danilović Gordana M.

    2015-01-01

    Full Text Available Two fungal strains were applied to soil polluted with herbicide in order to determine their degradation potential. Three experimental setups were used. In the first setup, the soil in pots was contaminated by linuron in final concentration of 1 ppm. Suspensions of Phanerocheate chrysosporium and Trichoderma asperellum were applied sepa­rately or in combination. Tomato plantlets were transplanted and chlorophyll content in their leaves was determined at two time points during plant growth. In the second setup in pots, the final concentration of linuron was lower, 0.45 ppm. In the third setup 0.1 ppm of linuron was applied in the field plot. Plantlets of lettuce were transplanted and chlorophyll content was measured as indicator of plant stress. The content of linuron in soil was determined by HPLC. The applied fungal strains significantly reduced toxic effect of 0.45 ppm linuron on plants, which was not the case for 1 ppm linuron. Both fungi, applied separately or in combination, were effective in decreasing the linuron content in the soil. However, in field conditions the combination of both fungi was the most effective. [Projekat Ministarstva nauke Republike Srbije, br. III43010

  19. Novel method for separation and screening of lubricant-degrading microorganisms and bacterial biodegradation☆

    Institute of Scientific and Technical Information of China (English)

    Yan Jiang; Hui Qi; Xianming Zhang

    2016-01-01

    With the rapid increase of lubricant consumption, oil contamination becomes more serious. Biotreatment is an important method to remove oil contamination with some advantages. In this study, acclimatized oil-contaminated soil and used lubricating oil were sampled to isolate lubricant-degrading strains by several methods. 51 isolates were obtained and 24-well plates were employed to assess bacterial potential in high-throughput screening. The method was noted for the prominence of oil–water two-phase system with saving chemicals, shortening cycles and lessening workloads. In order to decrease inaccuracy, subculture and resting cells were inoculated into mineral salt medium with 200μl oil in well plates for the cultivation at 37 °C for 5 and 7 days, and the biodegradation potential was characterized by the changes of oil film and cell density. With appropriate evaluation by shaking flask tests, 5 isolates were retained for their potentials with the maxi-mum biodegradation from 1500 to 2200 mg · L−1 and identified as Acidovorax citrul i, Pseudomonas balearica, Acinetobacter johnsoni (two isolates with different biodegradation potentials) and Acidovorax avenae using 16S rRNA sequencing analysis. Also, lipase activity was determined using indicator titration and p-nitrophenyl palmitate (p-NPP) methods. The results indicated that only p-NPP was successful to test lipase activity with the range of 1.93–6.29 U · ml−1. Although these five strains could degrade 1000 mg · L−1 lubricating oil in 158–168 h, there existed distinct difference in enzyme activity, which demonstrates that lipase activity could not be used as the criterion to evaluate microbial biodegradation potential for petroleum hydrocarbons.

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

    Science.gov (United States)

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

    2016-11-15

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

  1. Impact of hydrocarbons, PCBs and heavy metals on bacterial communities in Lerma River, Salamanca, Mexico: Investigation of hydrocarbon degradation potential.

    Science.gov (United States)

    Brito, Elcia M S; De la Cruz Barrón, Magali; Caretta, César A; Goñi-Urriza, Marisol; Andrade, Leandro H; Cuevas-Rodríguez, Germán; Malm, Olaf; Torres, João P M; Simon, Maryse; Guyoneaud, Remy

    2015-07-15

    Freshwater contamination usually comes from runoff water or direct wastewater discharges to the environment. This paper presents a case study which reveals the impact of these types of contamination on the sediment bacterial population. A small stretch of Lerma River Basin, heavily impacted by industrial activities and urban wastewater release, was studied. Due to industrial inputs, the sediments are characterized by strong hydrocarbon concentrations, ranging from 2 935 to 28 430μg·kg(-1) of total polyaromatic hydrocarbons (PAHs). These sediments are also impacted by heavy metals (e.g., 9.6μg·kg(-1) of Cd and 246μg·kg(-1) of Cu, about 8 times the maximum recommended values for environmental samples) and polychlorinated biphenyls (ranging from 54 to 123μg·kg(-1) of total PCBs). The bacterial diversity on 6 sediment samples, taken from upstream to downstream of the main industrial and urban contamination sources, was assessed through TRFLP. Even though the high PAH concentrations are hazardous to aquatic life, they are not the only factor driving bacterial community composition in this ecosystem. Urban discharges, leading to hypoxia and low pH, also strongly influenced bacterial community structure. The bacterial bioprospection of these samples, using PAH as unique carbon source, yielded 8 hydrocarbonoclastic strains. By sequencing the 16S rDNA gene, these were identified as similar to Mycobacterium goodii, Pseudomonas aeruginosa, Pseudomonas lundensis or Aeromonas veronii. These strains showed high capacity to degrade naphthalene (between 92 and 100% at 200mg·L(-1)), pyrene (up to 72% at 100mg·L(-1)) and/or fluoranthene (52% at 50mg·L(-1)) as their only carbon source on in vitro experiments. These hydrocarbonoclastic bacteria were detected even in the samples upstream of the city of Salamanca, suggesting chronical contamination, already in place longer before. Such microorganisms are clearly potential candidates for hydrocarbon degradation in the

  2. Characterization and Genomic Analysis of a Highly Efficient Dibutyl Phthalate-Degrading Bacterium Gordonia sp. Strain QH-12

    Science.gov (United States)

    Jin, Decai; Kong, Xiao; Liu, Huijun; Wang, Xinxin; Deng, Ye; Jia, Minghong; Yu, Xiangyang

    2016-01-01

    A bacterial strain QH-12 isolated from activated sludge was identified as Gordonia sp. based on analysis of 16S rRNA gene sequence and was found to be capable of utilizing dibutyl phthalate (DBP) and other common phthalate esters (PAEs) as the sole carbon and energy source. The degradation kinetics of DBP under different concentrations by the strain QH-12 fit well with the modified Gompertz model (R2 > 0.98). However, strain QH-12 could not utilize the major intermediate product phthalate (phthalic acid; PA) as the sole carbon and energy source, and only a little amount of PA was detected. The QH-12 genome analysis revealed the presence of putative hydrolase/esterase genes involved in PAEs-degradation but no phthalic acid catabolic gene cluster was found, suggesting that a novel degradation pathway of PAEs was present in Gordonia sp. QH-12. This information will be valuable for obtaining a more holistic understanding on diverse genetic mechanisms of PAEs-degrading Gordonia sp. strains. PMID:27347943

  3. Characterization and Genomic Analysis of a Highly Efficient Dibutyl Phthalate-Degrading Bacterium Gordonia sp. Strain QH-12

    Directory of Open Access Journals (Sweden)

    Decai Jin

    2016-06-01

    Full Text Available A bacterial strain QH-12 isolated from activated sludge was identified as Gordonia sp. based on analysis of 16S rRNA gene sequence and was found to be capable of utilizing dibutyl phthalate (DBP and other common phthalate esters (PAEs as the sole carbon and energy source. The degradation kinetics of DBP under different concentrations by the strain QH-12 fit well with the modified Gompertz model (R2 > 0.98. However, strain QH-12 could not utilize the major intermediate product phthalate (phthalic acid; PA as the sole carbon and energy source, and only a little amount of PA was detected. The QH-12 genome analysis revealed the presence of putative hydrolase/esterase genes involved in PAEs-degradation but no phthalic acid catabolic gene cluster was found, suggesting that a novel degradation pathway of PAEs was present in Gordonia sp. QH-12. This information will be valuable for obtaining a more holistic understanding on diverse genetic mechanisms of PAEs-degrading Gordonia sp. strains.

  4. Aerobic digestion of tannery wastewater in a sequential batch reactor by salt-tolerant bacterial strains

    Science.gov (United States)

    Durai, G.; Rajasimman, M.; Rajamohan, N.

    2011-09-01

    Among the industries generating hyper saline effluents, tanneries are prominent in India. Hyper saline wastewater is difficult to treat by conventional biological treatment methods. Salt-tolerant microbes can adapt to these conditions and degrade the organics in hyper saline wastewater. In this study, the performance of a bench scale aerobic sequencing batch reactor (SBR) was investigated to treat the tannery wastewater by the salt-tolerant bacterial strains namely Pseudomonas aeruginosa, Bacillus flexus, Exiguobacterium homiense and Styphylococcus aureus. The study was carried out under different operating conditions by changing the hydraulic retention time, organic loading rate and initial substrate concentration. From the results it was found that a maximum COD reduction of 90.4% and colour removal of 78.6% was attained. From this study it was found that the salt-tolerant microorganisms could improve the reduction efficiency of COD and colour of the tannery wastewater.

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

    African Journals Online (AJOL)

    IASA

    2016-10-05

    Oct 5, 2016 ... that the highest growth rate of microbial consortium was observed during degradation of various pesticides .... is Gram positive, aerobic, catalase, oxidase and King B .... sp. nov., isolated from root nodules of Pisumsativum.

  6. Ultrasound-assisted degradation of a new bacterial ...

    African Journals Online (AJOL)

    user

    2012-05-14

    May 14, 2012 ... cable as a gelling agent at high temperature when other gelling agents ... distinguish it from thermal or photochemical degradation. (Price and Smith ... S64 spindle. Monosaccharide analysis ..... power ultrasound. Ultrason ...

  7. Naphthalene degradation by bacterial consortium (DV-AL) developed from Alang-Sosiya ship breaking yard, Gujarat, India.

    Science.gov (United States)

    Patel, Vilas; Jain, Siddharth; Madamwar, Datta

    2012-03-01

    Naphthalene degrading bacterial consortium (DV-AL) was developed by enrichment culture technique from sediment collected from the Alang-Sosiya ship breaking yard, Gujarat, India. The 16S rRNA gene based molecular analyzes revealed that the bacterial consortium (DV-AL) consisted of four strains namely, Achromobacter sp. BAB239, Pseudomonas sp. DV-AL2, Enterobacter sp. BAB240 and Pseudomonas sp. BAB241. Consortium DV-AL was able to degrade 1000 ppm of naphthalene in Bushnell Haas medium (BHM) containing peptone (0.1%) as co-substrate with an initial pH of 8.0 at 37°C under shaking conditions (150 rpm) within 24h. Maximum growth rate and naphthalene degradation rate were found to be 0.0389 h(-1) and 80 mg h(-1), respectively. Consortium DV-AL was able to utilize other aromatic and aliphatic hydrocarbons such as benzene, phenol, carbazole, petroleum oil, diesel fuel, and phenanthrene and 2-methyl naphthalene as sole carbon source. Consortium DV-AL was also efficient to degrade naphthalene in the presence of other pollutants such as petroleum hydrocarbons and heavy metals.

  8. Isolation and characterization of xylan-degrading strains of Butyrivibrio fibrisolvens from a napier grass-fed anaerobic digester

    Energy Technology Data Exchange (ETDEWEB)

    Sewell, G.W.; Aldrich, H.C.; Williams, D.; Mannarelli, B.; Wilkie, A.; Hespell, R.B.; Smith, P.H.; Ingram, L.O.

    1988-05-01

    Six new xylanolytic bacterial strains have been isolated from a Napier grass-fed anaerobic digester. These strains were identified as Butyrivibrio fibrisolvens and were similar in many respects to ruminal isolates described previously. The new isolates exhibited a high degree of DNA homology with several ruminal strains of B. fibrisolvens. Xylan or xylose was required to induce the production of enzymes for xylan degradation, xylanase and xylosidase. Production of these was repressed in the presence of glucose. Xylanase activity was predominantly extracellular, while that of xylosidases was cell associated. The new isolates of B. fibrisolvens grew well in defined medium containing xylan as the sole carbon source and did not produce obvious slime or capsular layers. These strains may be useful for future genetic investigations.

  9. Evaluation of different lactic acid bacterial strains for probiotic characteristics

    Directory of Open Access Journals (Sweden)

    B. Srinu,

    2013-08-01

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

  10. Factors that influence the speed of bacterial wood degradation

    NARCIS (Netherlands)

    Klaassen, R.K.W.M.; Overeem, van B.S.

    2012-01-01

    Bacterial wood decay is a serious threat to the many wooden foundation piles in the Netherlands. In order to learn more about the factors that influence the process of decay, approx. 2000 wood samples taken from Amsterdam piles heads were analysed on type and degree of decay and for 59 extracted pil

  11. Genomic Encyclopedia of Bacterial and Archaeal Type Strains, Phase III: the genomes of soil and plant-associated and newly described type strains.

    Science.gov (United States)

    Whitman, William B; Woyke, Tanja; Klenk, Hans-Peter; Zhou, Yuguang; Lilburn, Timothy G; Beck, Brian J; De Vos, Paul; Vandamme, Peter; Eisen, Jonathan A; Garrity, George; Hugenholtz, Philip; Kyrpides, Nikos C

    2015-01-01

    The Genomic Encyclopedia of Bacteria and Archaea (GEBA) project was launched by the JGI in 2007 as a pilot project to sequence about 250 bacterial and archaeal genomes of elevated phylogenetic diversity. Herein, we propose to extend this approach to type strains of prokaryotes associated with soil or plants and their close relatives as well as type strains from newly described species. Understanding the microbiology of soil and plants is critical to many DOE mission areas, such as biofuel production from biomass, biogeochemistry, and carbon cycling. We are also targeting type strains of novel species while they are being described. Since 2006, about 630 new species have been described per year, many of which are closely aligned to DOE areas of interest in soil, agriculture, degradation of pollutants, biofuel production, biogeochemical transformation, and biodiversity.

  12. Pathways for degrading TNT by Thu-Z: a Pantoea sp. strain.

    Science.gov (United States)

    Zou, Liangdong; Lu, Diannan; Liu, Zheng

    2012-12-01

    2,4,6-Trinitrotoluene (TNT), an extensively used and versatile explosive, is harmful in soil and water. In the present study, four bacterial strains capable of degrading TNT have been isolated from contaminated sites and named as Thu-A, Thu-B, Thu-C, and Thu-Z. Thu-Z, which gave the highest degradation efficiency compared to the others, was assigned to the genus Pantoea according to its 16S rRNA gene. Similarities in both biochemical properties and morphology suggested that Thu-Z was a Pantoea sp. strain. Thu-Z was proved to be capable of using TNT as a sole nitrogen source by cleaving NO(2) from the nitroaromatic ring by direct aromatic ring reduction. Under nitrogen-limited conditions, 96.6 % N of TNT was consumed by Thu-Z for growth, which was determined in terms of NaNO(2). Trace nitro reduction metabolites such as 2,4-diamino-6-nitrotoluene (24Dam) and 2,6-diamino-4-nitrotoluene (26Dam) were identified in the presence of (NH(4))(2)SO(4). On the other hand, 4,4',6,6'-tetranitro-2,2'-azoxytoluene (22Azo) and 2,2',6,6'-tetranitro-4,4'-azoxytoluene (44Azo) were detected in the absence of (NH(4))(2)SO(4). These indicated the existence of a dual pathway for Thu-Z, while the direct aromatic ring reduction was predominant. Addition of a nitrogen source ((NH(4))(2)SO(4)) after inoculation stimulated the growth of Thu-Z and accelerated TNT degradation.

  13. ISOLATION AND CHARACTERIZATION OF BIFENTHRIN CATABOLIZING BACTERIAL STRAIN BACILLUS CIBI FROM SOIL FOR PYRETHROIDS BIODEGRADATION

    Directory of Open Access Journals (Sweden)

    Preeti Pandey

    2014-01-01

    Full Text Available Pyrethroids are commonly used in most parts of the world and are reported to have potential health risks. Bifenthrin, a third generation pyrethroid used as insecticide has caused potential effect on aquatic life and human health. Bioremediation is a practical approach to reduce pesticide in the environment and reports of microbial degradation of bifenthrin are meagre. This study was aimed at isolating and characterizing bacterial isolates for the efficient removal of bifenthrin residues in the environment. A bacterial strain PGS-4 isolated from sewage of pesticide industry was tested for growth at higher concentration of bifenthrin (800 mg L-1 and the optimum pH and temperature were determined. The strain utilized bifenthrin as sole carbon source for growth over a wide range of pH (4.0-9.0 and temperatures (16-37°C. On the basis of growth kinetics studies, the optimal conditions were determined to be pH 7.0-8.0 and 30°C. 16S rRNA gene sequence analysis showed that strain PGS-4 forms a distinct phylogenetic lineage within the evolutionary radiation encompassed by the genus Bacillus and showed 99% similarity to that of Bacillus cibi. This study depicts the ability of B. cibi to utilize bifenthrin at higher concentration under in vitro thereby can be used in eliminating bifenthrin from contaminated soils as a practical approach to reduce pyrethroid toxicity in the environment.

  14. Degradation of Polyester Polyurethane by Bacterial Polyester Hydrolases

    Directory of Open Access Journals (Sweden)

    Juliane Schmidt

    2017-02-01

    Full Text Available Polyurethanes (PU are widely used synthetic polymers. The growing amount of PU used industrially has resulted in a worldwide increase of plastic wastes. The related environmental pollution as well as the limited availability of the raw materials based on petrochemicals requires novel solutions for their efficient degradation and recycling. The degradation of the polyester PU Impranil DLN by the polyester hydrolases LC cutinase (LCC, TfCut2, Tcur1278 and Tcur0390 was analyzed using a turbidimetric assay. The highest hydrolysis rates were obtained with TfCut2 and Tcur0390. TfCut2 also showed a significantly higher substrate affinity for Impranil DLN than the other three enzymes, indicated by a higher adsorption constant K. Significant weight losses of the solid thermoplastic polyester PU (TPU Elastollan B85A-10 and C85A-10 were detected as a result of the enzymatic degradation by all four polyester hydrolases. Within a reaction time of 200 h at 70 °C, LCC caused weight losses of up to 4.9% and 4.1% of Elastollan B85A-10 and C85A-10, respectively. Gel permeation chromatography confirmed a preferential degradation of the larger polymer chains. Scanning electron microscopy revealed cracks at the surface of the TPU cubes as a result of enzymatic surface erosion. Analysis by Fourier transform infrared spectroscopy indicated that the observed weight losses were a result of the cleavage of ester bonds of the polyester TPU.

  15. Penicillium strains as dominant degraders in soil for coffee residue, a biological waste unsuitable for fertilization.

    Science.gov (United States)

    Fujii, Katsuhiko; Takeshi, Kyoko

    2007-12-01

    Coffee residue is an agricultural waste which inhibits the growth of several crops. Therefore coffee residue-degrading microbes in soil were screened, isolated and characterized. Forty isolates were obtained after enrichment culture of soil samples. Seven strains (fast degraders) showed strong degrading activity, while 18 strains (slow degraders) showed weak degrading activity. DNA analysis suggested that the fast degraders are Penicillium, and the slow degraders are Penicillium, Trichoderma/Hypocrea, Fusarium/Gibberella, Phaeoacremonium/Togninia or Acidocella. The all fast degraders are cellulolytic, mannolytic and pectinolytic. Although it is generally thought that fungi such as Trichoderma contribute largely to aerobic degradation of cellulosic biomass, our data suggested that Penicillium overwhelms them in coffee residue degradation. It was implied that polysaccharides in coffee residue are not degraded independently by different microbes, but degraded simultaneously by strains with cellulolytic, mannolytic and pectinolytic activity. Since there is no report of an ascomycete possessing all the three enzyme activities, the fast degraders are ecologically important and have the potential to be used as producers of the costly enzymes from agricultural wastes. The present results advance our understanding of microbial degradation of a phytotoxic agricultural waste, and offer a new tool for recycling it.

  16. Acceleration of Fibrous Biomass Degradation by Bacterial Enzymes

    OpenAIRE

    大宮, 邦雄; 河津, 哲; 孫, 嘉琳; 木村, 哲哉; 苅田, 修一; 粟冠, 和郎; Ohmiya,Kunio; Kawazu, Tetsu; Sun, Jialin; KIMURA, TETSUYA; Karita, Shuichi; Sakka, Kazuo

    1997-01-01

    Since biomass photosynthesized from C02 and H2O is one of the most predominant storage sites of solar energy, its effective utilization will be essential to overcome the shortage of foods and energy in future. Relaxation of biomass tissue is focused to enhance solubilization by expressing fiber‐degrading enzyme genes in plants. A xylanase gene from Clostridium thermocellum was highly expressed in tobacco plant (4%) without apparent defects in the growth. Another xylanase from Clostridium ste...

  17. Hydrocarbon-Degrading Bacteria and the Bacterial Community Response in Gulf of Mexico Beach Sands Impacted by the Deepwater Horizon Oil Spill▿†‡

    Science.gov (United States)

    Kostka, Joel E.; Prakash, Om; Overholt, Will A.; Green, Stefan J.; Freyer, Gina; Canion, Andy; Delgardio, Jonathan; Norton, Nikita; Hazen, Terry C.; Huettel, Markus

    2011-01-01

    A significant portion of oil from the recent Deepwater Horizon (DH) oil spill in the Gulf of Mexico was transported to the shoreline, where it may have severe ecological and economic consequences. The objectives of this study were (i) to identify and characterize predominant oil-degrading taxa that may be used as model hydrocarbon degraders or as microbial indicators of contamination and (ii) to characterize the in situ response of indigenous bacterial communities to oil contamination in beach ecosystems. This study was conducted at municipal Pensacola Beach, FL, where chemical analysis revealed weathered oil petroleum hydrocarbon (C8 to C40) concentrations ranging from 3.1 to 4,500 mg kg−1 in beach sands. A total of 24 bacterial strains from 14 genera were isolated from oiled beach sands and confirmed as oil-degrading microorganisms. Isolated bacterial strains were primarily Gammaproteobacteria, including representatives of genera with known oil degraders (Alcanivorax, Marinobacter, Pseudomonas, and Acinetobacter). Sequence libraries generated from oiled sands revealed phylotypes that showed high sequence identity (up to 99%) to rRNA gene sequences from the oil-degrading bacterial isolates. The abundance of bacterial SSU rRNA gene sequences was ∼10-fold higher in oiled (0.44 × 107 to 10.2 × 107 copies g−1) versus clean (0.024 × 107 to 1.4 × 107 copies g−1) sand. Community analysis revealed a distinct response to oil contamination, and SSU rRNA gene abundance derived from the genus Alcanivorax showed the largest increase in relative abundance in contaminated samples. We conclude that oil contamination from the DH spill had a profound impact on the abundance and community composition of indigenous bacteria in Gulf beach sands, and our evidence points to members of the Gammaproteobacteria (Alcanivorax, Marinobacter) and Alphaproteobacteria (Rhodobacteraceae) as key players in oil degradation there. PMID:21948834

  18. Detection of carboxylesterase and esterase activity in culturable gut bacterial flora isolated from diamondback moth, Plutella xylostella (Linnaeus, from India and its possible role in indoxacarb degradation

    Directory of Open Access Journals (Sweden)

    Shanivarsanthe Leelesh Ramya

    2016-06-01

    Full Text Available Abstract Diamondback moth (DBM, Plutella xylostella (Linnaeus, is a notorious pest of brassica crops worldwide and is resistant to all groups of insecticides. The insect system harbors diverse groups of microbiota, which in turn helps in enzymatic degradation of xenobiotic-like insecticides. The present study aimed to determine the diversity of gut microflora in DBM, quantify esterase activity and elucidate their possible role in degradation of indoxacarb. We screened 11 geographic populations of DBM in India and analyzed them for bacterial diversity. The culturable gut bacterial flora underwent molecular characterization with 16S rRNA. We obtained 25 bacterial isolates from larvae (n = 13 and adults (n = 12 of DBM. In larval gut isolates, gammaproteobacteria was the most abundant (76%, followed by bacilli (15.4%. Molecular characterization placed adult gut bacterial strains into three major classes based on abundance: gammaproteobacteria (66%, bacilli (16.7% and flavobacteria (16.7%. Esterase activity from 19 gut bacterial isolates ranged from 0.072 to 2.32 µmol/min/mg protein. Esterase bands were observed in 15 bacterial strains and the banding pattern differed in Bacillus cereus – KC985225 and Pantoea agglomerans – KC985229. The bands were characterized as carboxylesterase with profenofos used as an inhibitor. Minimal media study showed that B. cereus degraded indoxacarb up to 20%, so it could use indoxacarb for metabolism and growth. Furthermore, esterase activity was greater with minimal media than control media: 1.87 versus 0.26 µmol/min/mg protein. Apart from the insect esterases, bacterial carboxylesterase may aid in the degradation of insecticides in DBM.

  19. Continuous degradation of trichloroethylene by Xanthobacter sp. strain Py2 during growth on propene.

    OpenAIRE

    Reij, M.W.; Kieboom, J.; de Bont, J A; Hartmans, S

    1995-01-01

    Propene-grown Xanthobacter sp. strain Py2 cells can degrade trichloroethylene (TCE), but the transformation capacity of such cells was limited and depended on both the TCE concentration and the biomass concentration. Toxic metabolites presumably accumulated extracellularly, because the fermentation of glucose by yeast cells was inhibited by TCE degradation products formed by strain Py2. The affinity of the propene monooxygenase for TCE was low, and this allowed strain Py2 to grow on propene i...

  20. Degradative capacities of bacteria and fungi isolated from a fuel-contaminated soil. Capacites degradatives de bacteries et de champignons isoles d'un sol contamine par un fuel

    Energy Technology Data Exchange (ETDEWEB)

    Oudot, J.; Fusey, P.; Abdelouahid, D.E.; Haloui, S.; Roquebert, M.F. (Museum national d' histoire naturelle, Cedex (France))

    1987-01-01

    The long-term influence of a fuel spill on the bacterial and fungal communities of an agricultural soil was studied. Three years after the contamination, biodegradation of the fuel in the soil was achieved and after 5 years the residual compounds had no significant effect on the density and the specific composition of the microbial populations of the soil. Hydrocarbon-oxidizing bacteria Corynebacterium and Nocardia spp. were isolated. Most of the active fungi were Aspergillus and Penicillium spp., but strains of Paecilomyces, Acremonium, Fusarium, and Gliocladium were also identified. In laboratory experiments, the biodegration rate of a reference crude oil by pure cultures of oil-degrading strains was nearly the same as in mixed cultures. The biodegradation potential of the strains isolated from the control plot was as high as strains isolated from the oiled plot. In the soil, as in laboratory cultures, the saturate hydrocarbons were more degraded than the aromatics, whereas the resins and asphaltenes were resistant to microbial attack, as were polycyclic alkanes, steranes and triterpanes. Nocardia degraded preferentially the aromatics and attacked significantly the asphaltenes, as did Fusarium oxysporum. Aspergillus niger, Aspergillus flavus, and Fusarium oxysporum degraded part of the resins. The spectrum of the initial degradation of petroleum by the most active fungi and bacteria was identical, and it appears that the enzymatic equipment necessary to oxidize hydrocarbons is quite complete in these strains. 21 refs., 9 figs., 5 tabs.

  1. Bacterial Community Dynamics and Polycyclic Aromatic Hydrocarbon Degradation during Bioremediation of Heavily Creosote-Contaminated Soil

    OpenAIRE

    Viñas, Marc; Sabaté, Jordi; Espuny, María José; Solanas, Anna M.

    2005-01-01

    Bacterial community dynamics and biodegradation processes were examined in a highly creosote-contaminated soil undergoing a range of laboratory-based bioremediation treatments. The dynamics of the eubacterial community, the number of heterotrophs and polycyclic aromatic hydrocarbon (PAH) degraders, and the total petroleum hydrocarbon (TPH) and PAH concentrations were monitored during the bioremediation process. TPH and PAHs were significantly degraded in all treatments (72 to 79% and 83 to 87...

  2. Application of two bacterial strains for wastewater bioremediation and assessment of phenolics biodegradation.

    Science.gov (United States)

    Paisio, Cintia E; Quevedo, María R; Talano, Melina A; González, Paola S; Agostini, Elizabeth

    2014-08-01

    The use of native bacteria is a useful strategy to decontaminate industrial effluents. In this work, two bacterial strains isolated from polluted environments constitutes a promising alternative since they were able to remove several phenolic compounds not only from synthetic solutions but also from effluents derived from a chemical industry and a tannery which are complex matrices. Acinetobacter sp. RTE 1.4 showed ability to completely remove 2-methoxyphenol (1000 mg/L) while Rhodococcus sp. CS 1 not only degrade the same concentration of this compound but also removed 4- chlorophenol, 2,4-dichlorophenol and pentachlorophenol with high efficiency. Moreover, both bacteria degraded phenols naturally present or even exogenously added at high concentrations in effluents from the chemical industry and a tannery in short time (up to 5 d). In addition, a significant reduction of biological oxygen demand and chemical oxygen demand values was achieved after 7 d of treatment for both effluents using Acinetobacter sp. RTE 1.4 and Rhodococcus sp. CS1, respectively. These results showed that Acinetobacter sp. RTE1.4 and Rhodococcus sp. CS 1 might be considered as useful biotechnological tools for an efficient treatment of different effluents, since they showed wide versatility to detoxify these complex matrices, even supplemented with high phenol concentrations.

  3. Strain dependent UV degradation of Escherichia coli DNA monitored by Fourier transform infrared spectroscopy.

    Science.gov (United States)

    Muntean, Cristina M; Lapusan, Alexandra; Mihaiu, Liora; Stefan, Razvan

    2014-01-05

    In this work we present a method for detection of DNA isolated from nonpathogenic Escherichia coli strains, respectively. Untreated and UV irradiated bacterial DNAs were analyzed by FT-IR spectroscopy, to investigate their screening characteristic features and their structural radiotolerance at 253.7nm. FT-IR spectra, providing a high molecular structural information, have been analyzed in the wavenumber range 800-1800cm(-1). FT-IR signatures, spectroscopic band assignments and structural interpretations of these DNAs are reported. Also, UV damage at the DNA molecular level is of interest. Strain dependent UV degradation of DNA from E. coli has been observed. Particularly, alterations in nucleic acid bases, base pairing and base stacking have been found. Also changes in the DNA conformation and deoxyribose were detected. Based on this work, specific E. coli DNA-ligand interactions, drug development and vaccine design for a better understanding of the infection mechanism caused by an interference between pathogenic and nonpathogenic bacteria and for a better control of disease, respectively, might be further investigated using Fourier transform infrared spectroscopy. Besides, understanding the pathways for UV damaged DNA response, like nucleic acids repair mechanisms is appreciated.

  4. High bacterial biodiversity increases degradation performance of hydrocarbons during bioremediation of contaminated harbor marine sediments.

    Science.gov (United States)

    Dell'Anno, Antonio; Beolchini, Francesca; Rocchetti, Laura; Luna, Gian Marco; Danovaro, Roberto

    2012-08-01

    We investigated changes of bacterial abundance and biodiversity during bioremediation experiments carried out on oxic and anoxic marine harbor sediments contaminated with hydrocarbons. Oxic sediments, supplied with inorganic nutrients, were incubated in aerobic conditions at 20 °C and 35 °C for 30 days, whereas anoxic sediments, amended with organic substrates, were incubated in anaerobic conditions at the same temperatures for 60 days. Results reported here indicate that temperature exerted the main effect on bacterial abundance, diversity and assemblage composition. At higher temperature bacterial diversity and evenness increased significantly in aerobic conditions, whilst decreased in anaerobic conditions. In both aerobic and anaerobic conditions, biodegradation efficiencies of hydrocarbons were significantly and positively related with bacterial richness and evenness. Overall results presented here suggest that bioremediation strategies, which can sustain high levels of bacterial diversity rather than the selection of specific taxa, may significantly increase the efficiency of hydrocarbon degradation in contaminated marine sediments.

  5. Rapid identification and discrimination of bacterial strains by laser induced breakdown spectroscopy and neural networks.

    Science.gov (United States)

    Manzoor, S; Moncayo, S; Navarro-Villoslada, F; Ayala, J A; Izquierdo-Hornillos, R; de Villena, F J Manuel; Caceres, J O

    2014-04-01

    Identification and discrimination of bacterial strains of same species exhibiting resistance to antibiotics using laser induced breakdown spectroscopy (LIBS) and neural networks (NN) algorithm is reported. The method has been applied to identify 40 bacterial strains causing hospital acquired infections (HAI), i.e. Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Salmonella typhimurium, Salmonella pullurum and Salmonella salamae. The strains analyzed included both isolated from clinical samples and constructed in laboratory that differ in mutations as a result of their resistance to one or more antibiotics. Small changes in the atomic composition of the bacterial strains, as a result of their mutations and genetic variations, were detected by the LIBS-NN methodology and led to their identification and classification. This is of utmost importance because solely identification of bacterial species is not sufficient for disease diagnosis and identification of the actual strain is also required. The proposed method was successfully able to discriminate strains of the same bacterial species. The optimized NN models provided reliable bacterial strain identification with an index of spectral correlation higher than 95% for the samples analyzed, showing the potential and effectiveness of the method to address the safety and social-cost HAI-related issue. Copyright © 2013 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Maryam Jalili Tabaii

    2015-12-01

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

  7. Microbial taxa and functional genes shift in degraded soil with bacterial wilt

    Science.gov (United States)

    Zhang, Hongchun; Wang, Rui; Chen, Shu; Qi, Gaofu; He, Zhili; Zhao, Xiuyun

    2017-01-01

    Soil degradation is a serious global problem, but little is known about how soil microbial communities respond to soil degradation as well as their feedback to ecosystem functioning. In this study, we found the microbial community composition, structure and functional potential significantly altered in the degraded soils with bacterial wilt (termed as degraded soils). Compared with healthy soils, OTU richness of beneficial microorganisms were significantly decreased, but OTU richness of pathogenic microorganisms were significantly increased in the degraded soils. Functional gene array (GeoChip 5.0) analysis showed the functional metabolic potential of genes involved in stress, virulence, sulfur cycle, metal resistance, degradation of plant cell wall was significantly increased in the degraded soils. Increased functional metabolic potential of these genes may be related to the acidification and severe plant disease of degraded soils. Biological activity of degraded soils was obviously decreased with weakened soil enzyme activities when compared to the healthy soils. Soil pH and enzyme activities were negatively correlated with the abundance of genes involved in sulfur cycle, virulence, and stress responses. This study provides new insights into our understanding of soil microbial community responses to soil degradation. PMID:28051173

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-12-01

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

  9. Enrichment and isolation of microbial strains degrading bioplastic ...

    African Journals Online (AJOL)

    acer

    2015-07-08

    Jul 8, 2015 ... Key words: Polyvinyl alcohol (PVA) degrading bacteria, isolation, ultimate biodegradation, mineralization. ... for its application in the production of environmental- ..... Thalassospira povalilytica from compost and marine.

  10. Fungal–bacterial consortia increase diuron degradation in water-unsaturated systems

    DEFF Research Database (Denmark)

    Ellegaard-Jensen, Lea; Knudsen, Berith Elkær; Johansen, Anders;

    2014-01-01

    Abstract Bioremediation of pesticide-polluted soil may be more efficient using mixed fungal–bacterial cultures rather than the individual strains alone. This may be due to cooperative catabolism, where the first organism transforms the pollutant to products which are then used by the second......-member consortia. This study demonstrates new possibilities for applying efficient fungal–bacterial consortia for bioremediation of polluted soil....

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

    Directory of Open Access Journals (Sweden)

    Krishnaveni Venkidusamy

    2016-12-01

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

  12. Identification of Electrode Respiring, Hydrocarbonoclastic Bacterial Strain Stenotrophomonas maltophilia MK2 Highlights the Untapped Potential for Environmental Bioremediation

    Science.gov (United States)

    Venkidusamy, Krishnaveni; Megharaj, Mallavarapu

    2016-01-01

    Electrode respiring bacteria (ERB) possess a great potential for many biotechnological applications such as microbial electrochemical remediation systems (MERS) because of their exoelectrogenic capabilities to degrade xenobiotic pollutants. Very few ERB have been isolated from MERS, those exhibited a bioremediation potential toward organic contaminants. Here we report once such bacterial strain, Stenotrophomonas maltophilia MK2, a facultative anaerobic bacterium isolated from a hydrocarbon fed MERS, showed a potent hydrocarbonoclastic behavior under aerobic and anaerobic environments. Distinct properties of the strain MK2 were anaerobic fermentation of the amino acids, electrode respiration, anaerobic nitrate reduction and the ability to metabolize n-alkane components (C8–C36) of petroleum hydrocarbons (PH) including the biomarkers, pristine and phytane. The characteristic of diazoic dye decolorization was used as a criterion for pre-screening the possible electrochemically active microbial candidates. Bioelectricity generation with concomitant dye decolorization in MERS showed that the strain is electrochemically active. In acetate fed microbial fuel cells (MFCs), maximum current density of 273 ± 8 mA/m2 (1000 Ω) was produced (power density 113 ± 7 mW/m2) by strain MK2 with a coulombic efficiency of 34.8%. Further, the presence of possible alkane hydroxylase genes (alkB and rubA) in the strain MK2 indicated that the genes involved in hydrocarbon degradation are of diverse origin. Such observations demonstrated the potential of facultative hydrocarbon degradation in contaminated environments. Identification of such a novel petrochemical hydrocarbon degrading ERB is likely to offer a new route to the sustainable bioremedial process of source zone contamination with simultaneous energy generation through MERS. PMID:28018304

  13. Screening for and identification of starch-, amylopectin-, and pullulan-degrading activities in bifidobacterial strains.

    Science.gov (United States)

    Ryan, Sinéad M; Fitzgerald, Gerald F; van Sinderen, Douwe

    2006-08-01

    Forty-two bifidobacterial strains were screened for alpha-amylase and/or pullulanase activity by investigating their capacities to utilize starch, amylopectin, or pullulan. Of the 42 bifidobacterial strains tested, 19 were capable of degrading potato starch. Of these 19 strains, 11 were able to degrade starch and amylopectin, as well as pullulan. These 11 strains, which were shown to produce extracellular starch-degrading activities, included 5 strains of Bifidobacterium breve, 1 B. dentium strain, 1 B. infantis strain, 3 strains of B. pseudolongum, and 1 strain of B. thermophilum. Quantitative and qualitative enzyme activities were determined by measuring the concentrations of released reducing sugars and by high-performance thin-layer chromatography, respectively. These analyses confirmed both the inducible nature and the extracellular nature of the starch- and pullulan-degrading enzyme activities and showed that the five B. breve strains produced an activity that is consistent with type II pullulanase (amylopullulanase) activity, while the remaining six strains produced an activity with properties that resemble those of type III pullulan hydrolase.

  14. Laboratory-Cultured Strains of the Sea Anemone Exaiptasia Reveal Distinct Bacterial Communities

    KAUST Repository

    Herrera Sarrias, Marcela

    2017-05-02

    Exaiptasia is a laboratory sea anemone model system for stony corals. Two clonal strains are commonly used, referred to as H2 and CC7, that originate from two genetically distinct lineages and that differ in their Symbiodinium specificity. However, little is known about their other microbial associations. Here, we examined and compared the taxonomic composition of the bacterial assemblages of these two symbiotic Exaiptasia strains, both of which have been cultured in the laboratory long-term under identical conditions. We found distinct bacterial microbiota for each strain, indicating the presence of host-specific microbial consortia. Putative differences in the bacterial functional profiles (i.e., enrichment and depletion of various metabolic processes) based on taxonomic inference were also detected, further suggesting functional differences of the microbiomes associated with these lineages. Our study contributes to the current knowledge of the Exaiptasia holobiont by comparing the bacterial diversity of two commonly used strains as models for coral research.

  15. Mechanisms of tolerance and high degradation capacity of the herbicide mesotrione by Escherichia coli strain DH5-α.

    Directory of Open Access Journals (Sweden)

    Luiz R Olchanheski

    Full Text Available The intensive use of agrochemicals has played an important role in increasing agricultural production. One of the impacts of agrochemical use has been changes in population structure of soil microbiota. The aim of this work was to analyze the adaptive strategies that bacteria use to overcome oxidative stress caused by mesotrione, which inhibits 4-hydroxyphenylpyruvate dioxygenase. We also examined antioxidative stress systems, saturation changes of lipid membranes, and the capacity of bacteria to degrade mesotrione. Escherichia coli DH5-á was chosen as a non-environmental strain, which is already a model bacterium for studying metabolism and adaptation. The results showed that this bacterium was able to tolerate high doses of the herbicide (10× field rate, and completely degraded mesotrione after 3 h of exposure, as determined by a High Performance Liquid Chromatography. Growth rates in the presence of mesotrione were lower than in the control, prior to the period of degradation, showing toxic effects of this herbicide on bacterial cells. Changes in the saturation of the membrane lipids reduced the damage caused by reactive oxygen species and possibly hindered the entry of xenobiotics in the cell, while activating glutathione-S-transferase enzyme in the antioxidant system and in the metabolizing process of the herbicide. Considering that E. coli DH5-α is a non-environmental strain and it had no previous contact with mesotrione, the defense system found in this strain could be considered non-specific. This bacterium system response may be a general adaptation mechanism by which bacterial strains resist to damage from the presence of herbicides in agricultural soils.

  16. Aflatoxin B1 Degradation by a Pseudomonas Strain

    Science.gov (United States)

    Sangare, Lancine; Zhao, Yueju; Folly, Yawa Minnie Elodie; Chang, Jinghua; Li, Jinhan; Selvaraj, Jonathan Nimal; Xing, Fuguo; Zhou, Lu; Wang, Yan; Liu, Yang

    2014-01-01

    Aflatoxin B1 (AFB1), one of the most potent naturally occurring mutagens and carcinogens, causes significant threats to the food industry and animal production. In this study, 25 bacteria isolates were collected from grain kernels and soils displaying AFB1 reduction activity. Based on its degradation effectiveness, isolate N17-1 was selected for further characterization and identified as Pseudomonas aeruginosa. P. aeruginosa N17-1 could degrade AFB1, AFB2 and AFM1 by 82.8%, 46.8% and 31.9% after incubation in Nutrient Broth (NB) medium at 37 °C for 72 h, respectively. The culture supernatant of isolate N17-1 degraded AFB1 effectively, whereas the viable cells and intra cell extracts were far less effective. Factors influencing AFB1 degradation by the culture supernatant were investigated. Maximum degradation was observed at 55 °C. Ions Mn2+ and Cu2+ were activators for AFB1 degradation, however, ions Mg2+, Li+, Zn2+, Se2+, Fe3+ were strong inhibitors. Treatments with proteinase K and proteinase K plus SDS significantly reduced the degradation activity of the culture supernatant. No degradation products were observed based on preliminary LC-QTOF/MS analysis, indicating AFB1 was metabolized to degradation products with chemical properties different from that of AFB1. The results indicated that the degradation of AFB1 by P. aeruginosa N17-1 was enzymatic and could have a great potential in industrial applications. This is the first report indicating that the isolate of P. aeruginosa possesses the ability to degrade aflatoxin. PMID:25341538

  17. Screening of bacterial strains isolated from uranium mill tailings porewaters for bioremediation purposes.

    Science.gov (United States)

    Sánchez-Castro, Iván; Amador-García, Ahinara; Moreno-Romero, Cristina; López-Fernández, Margarita; Phrommavanh, Vannapha; Nos, Jeremy; Descostes, Michael; Merroun, Mohamed L

    2017-01-01

    The present work characterizes at different levels a number of bacterial strains isolated from porewaters sampled in the vicinity of two French uranium tailing repositories. The 16S rRNA gene from 33 bacterial isolates, corresponding to the different morphotypes recovered, was almost fully sequenced. The resulting sequences belonged to 13 bacterial genera comprised in the phyla Firmicutes, Actinobacteria and Proteobacteria. Further characterization at physiological level and metals/metalloid tolerance provided evidences for an appropriate selection of bacterial strains potentially useful for immobilization of uranium and other common contaminants. By using High Resolution Transmission Electron Microscope (HRTEM), this potential ability to immobilize uranium as U phosphate mineral phases was confirmed for the bacterial strains Br3 and Br5 corresponding to Arthrobacter sp. and Microbacterium oxydans, respectively. Scanning Transmission Electron Microscope- High-Angle Annular Dark-Field (STEM-HAADF) analysis showed U accumulates on the surface and within bacterial cytoplasm, in addition to the extracellular space. Energy Dispersive X-ray (EDX) element-distribution maps demonstrated the presence of U and P within these accumulates. These results indicate the potential of certain bacterial strains isolated from porewaters of U mill tailings for immobilizing uranium, likely as uranium phosphates. Some of these bacterial isolates might be considered as promising candidates in the design of uranium bioremediation strategies.

  18. Effect of inoculant strain and organic matter content on kinetics of 2,4-dichlorophenoxyacetic acid degradation in soil.

    Science.gov (United States)

    Greer, L E; Shelton, D R

    1992-01-01

    We monitored rates of degradation of soluble and sorbed 2,4-dichlorophenoxyacetic acid (2,4-D) in low-organic-matter soil at field capacity amended with 1, 10, or 100 micrograms of 2,4-D per g of wet soil and inoculated with one of two bacterial strains (MI and 155) with similar maximum growth rates (mu max) but significantly different half-saturation growth constants (Ks). Concentrations of soluble 2,4-D were determined by analyzing samples of pore water pressed from soil, and concentrations of sorbed 2,4-D were determined by solvent extraction. Between 65 and 75% of the total 2,4-D was present in the soluble phase at equilibrium, resulting in soil solution concentrations of ca. 8, 60, and 600 micrograms of 2,4-D per ml, respectively. Soluble 2,4-D was metabolized preferentially; this was followed by degradation of both sorbed (after desorption) and soluble 2,4-D. Rates of degradation were comparable for the two strains at soil concentrations of 10 and 100 micrograms of 2,4-D per g; however, at 1 microgram/g of soil, 2,4-D was metabolized more rapidly by the strain with the lower Ks value (strain MI). We also monitored rates of biodegradation of soluble and sorbed 2,4-D in high-organic-matter soil at field capacity amended with 100 micrograms of 2,4-D per g of wet soil and inoculated with the low-Ks strain (strain MI). Ten percent of total 2,4-D was present in the soluble phase, resulting in a soil solution concentration of ca. 30 micrograms of 2,4-D per ml.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1622212

  19. Evaluating robustness of a diesel-degrading bacterial consortium isolated from contaminated soil

    DEFF Research Database (Denmark)

    Sydow, Mateusz; Owsianiak, Mikolaj; Szczepaniak, Zuzanna;

    2016-01-01

    It is not known whether diesel-degrading bacterial communities are structurally and functionally robust when exposed to different hydrocarbon types. Here, we exposed a diesel-degrading consortium to model either alkanes, cycloalkanes or aromatic hydrocarbons as carbon sources to study its...... structural resistance. The structural resistance was low, with changes in relative abundances of up to four orders of magnitude, depending on hydrocarbon type and bacterial taxon. This low resistance is explained by the presence of hydrocarbon-degrading specialists in the consortium and differences in growth...... kinetics on individual hydrocarbons. However, despite this low resistance, structural and functional resilience were high, as verified by re-exposing the hydrocarbon-perturbed consortium to diesel fuel. The high resilience is either due to the short exposure time, insufficient for permanent changes...

  20. Evident bacterial community changes but only slight degradation when polluted with pyrene in a red soil

    Directory of Open Access Journals (Sweden)

    Gaidi eRen

    2015-01-01

    Full Text Available Understanding the potential for PAH degradation by indigenous microbiota and the influence of PAHs on native microbial communities is of great importance for bioremediation and ecological evaluation. Various studies have focused on the bacterial communities in the environment where obvious PAH degradation was observed, little is known about the microbiota in the soil where poor degradation was observed. Soil microcosms were constructed with a red soil by supplementation with a high-molecular-weight PAH (pyrene at three dosages (5, 30, and 70 mg.kg-1. Real-time PCR was used to evaluate the changes in bacterial abundance and pyrene dioxygenase gene (nidA quantity. Illumina sequencing was used to investigate changes in diversity, structure, and composition of bacterial communities. After 42 days of incubation, no evident degradation was observed. The poor degradation ability was associated with the stability or significant decrease of abundance of the nidA gene. Although the abundance of the bacterial 16S rRNA gene was not affected by pyrene, the bacterial richness and diversity were decreased with increasing dosage of pyrene and the community structure was changed. Phylotypes affected by pyrene were comprehensively surveyed: (1 at the high taxonomic level, seven of the abundant phyla/classes (relative abundance >1.0% including Chloroflexi, AD3, WPS-2, GAL5, Alphaproteobacteria, Actinobacteria, and Deltaproteobacteria and one rare phylum Crenarchaeota were significantly decreased by at least one dosage of pyrene, while 3 phyla/classes (Acidobacteria, Betaproteobacteria, and Gammaproteobacteria were significantly increased; and (2 at the lower taxonomic level, the relative abundances of twelve orders were significantly depressed, whereas those of nine orders were significantly increased. This work enhanced our understanding of the biodegradation potential of pyrene in red soil and the effect of pyrene on soil ecosystems at the microbial community

  1. Silicon compounds in solution during bacterial degradation of quartz

    Energy Technology Data Exchange (ETDEWEB)

    Avakyan, Z.A.; Belkanova, N.P.; Karavayko, G.I.; Piskunov, V.P.

    A study was made of the form of silicon compounds in solution in the following systems: distilled water-exopolysaccharides of Bacillus mucilaginosus-monomeric silica; distilled water-suspension of B. mucilaginosus cells-quartz; culture fluids-growing B. mucilaginosus or Thiobacillus thioparus cultures-quartz. In control variants, which contained no exopolysaccharides or bacteria, all of the silicon in solution is demonstrable with the reaction with molybdic acid in the form of monosilicic acid and, perhaps, its lower oligomers. The presence of exopolysaccharides or bacteria leads to the appearance of three forms of silicon compounds: monomeric, polymeric as demonstrable by reaction with molybdic acid after alkaline hydrolysis, and bound, which is demonstrable only by the sintering method. The pH, concentrations of exopolysaccharides and silicon are factors that control the proportion of these forms of silica in the systems studied with exopolysaccharides and resting cells. An increase in the concentration of polysaccharides in the system, as well as changes in medium reaction in the alkaline direction, shift equilibrium toward the formation of the bound form of silica. The mechanism of microbiological degradation of quartz and the formation of silicon compounds is discussed.

  2. Application of green fluorescent protein for monitoring phenol-degrading strains

    Directory of Open Access Journals (Sweden)

    Ana Milena Valderrama F.

    2011-12-01

    Full Text Available Several methods have been developed for detecting microorganisms in environmental samples. Some systems for incorporating reporter genes, such as lux or the green fluorescent protein (GFP gene, have been developed recently This study describes gfp gene marking of a phenol degrading strain, its evaluation and monitoring in a bioreactor containing refinery sour water. Tagged strains were obtained having the same physiological and metabolic characteristics as the parent strain. Fluorescent expression was kept stable with no selection for more than 50 consecutive generations and tagged strains were recovered from the bioreactor after forty-five days of phenol-degradation treatment. 

  3. Response of bacterial communities from California coastal waters to alginate particles and an alginolytic Alteromonas macleodii strain.

    Science.gov (United States)

    Mitulla, Maximilian; Dinasquet, Julie; Guillemette, Ryan; Simon, Meinhard; Azam, Farooq; Wietz, Matthias

    2016-12-01

    Alginate is a major cell wall polysaccharide from marine macroalgae and nutrient source for heterotrophic bacteria. Alginate can form gel particles in contact with divalent cations as found in seawater. Here, we tested the hypothesis that alginate gel particles serve as carbon source and microhabitat for marine bacteria by adding sterile alginate particles to microcosms with seawater from coastal California, a habitat rich in alginate-containing macroalgae. Alginate particles were rapidly colonized and degraded, with three- to eightfold higher bacterial abundances and production among alginate particle-associated (PA) bacteria. 16S rRNA gene amplicon sequencing showed that alginate PA bacteria were enriched in OTUs related to Cryomorphaceae, Saprospiraceae (Bacteroidetes) and Phaeobacter (Alphaproteobacteria) towards the end of the experiment. In microcosms amended with alginate particles and the proficient alginolytic bacterium Alteromonas macleodii strain 83-1, this strain dominated the community and outcompeted Cryomorphaceae, Saprospiraceae and Phaeobacter, and PA hydrolytic activities were over 50% higher. Thus, alginolytic activity by strain 83-1 did not benefit non-alginolytic strains by cross-feeding on alginate hydrolysis or other metabolic products. Considering the global distribution and extensive biomass of alginate-containing macroalgae, the observed bacterial dynamics associated with the utilization and remineralization of alginate microhabitats promote the understanding of carbon cycling in macroalgae-rich waters worldwide. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  4. Degradation pathway of 2-chloroethanol in Pseudomonas stutzeri strain JJ under denitrifying conditions

    NARCIS (Netherlands)

    Dijk, J.A.; Gerritse, J.; Schraa, G.; Stams, A.J.M.

    2004-01-01

    The pathway of 2-chloroethanol degradation in the denitrifying Pseudomonas stutzeri strain JJ was investigated. In cell-free extracts, activities of a phenazine methosulfate (PMS)-dependent chloroethanol dehydrogenase, an NAD-dependent chloroacetaldehyde dehydrogenase, and a chloroacetate dehalogena

  5. Complete genome sequence of Japanese erwinia strain ejp617, a bacterial shoot blight pathogen of pear.

    Science.gov (United States)

    Park, Duck Hwan; Thapa, Shree Prasad; Choi, Beom-Soon; Kim, Won-Sik; Hur, Jang Hyun; Cho, Jun Mo; Lim, Jong-Sung; Choi, Ik-Young; Lim, Chun Keun

    2011-01-01

    The Japanese Erwinia strain Ejp617 is a plant pathogen that causes bacterial shoot blight of pear in Japan. Here, we report the complete genome sequence of strain Ejp617 isolated from Nashi pears in Japan to provide further valuable insight among related Erwinia species.

  6. Fungal-bacterial consortia increase diuron degradation in water-unsaturated systems

    DEFF Research Database (Denmark)

    Ellegaard-Jensen, Lea; Knudsen, Berith Elkær; Johansen, Anders

    2014-01-01

    Abstract Bioremediation of pesticide-polluted soil may be more efficient using mixed fungal–bacterial cultures rather than the individual strains alone. This may be due to cooperative catabolism, where the first organism transforms the pollutant to products which are then used by the second organ...

  7. Lysozyme-coated silver nanoparticles for differentiating bacterial strains on the basis of antibacterial activity

    Science.gov (United States)

    Ashraf, Sumaira; Chatha, Mariyam Asghar; Ejaz, Wardah; Janjua, Hussnain Ahmed; Hussain, Irshad

    2014-10-01

    Lysozyme, an antibacterial enzyme, was used as a stabilizing ligand for the synthesis of fairly uniform silver nanoparticles adopting various strategies. The synthesized particles were characterized using UV-visible spectroscopy, FTIR, dynamic light scattering (DLS), and TEM to observe their morphology and surface chemistry. The silver nanoparticles were evaluated for their antimicrobial activity against several bacterial species and various bacterial strains within the same species. The cationic silver nanoparticles were found to be more effective against Pseudomonas aeruginosa 3 compared to other bacterial species/strains investigated. Some of the bacterial strains of the same species showed variable antibacterial activity. The difference in antimicrobial activity of these particles has led to the conclusion that antimicrobial products formed from silver nanoparticles may not be equally effective against all the bacteria. This difference in the antibacterial activity of silver nanoparticles for different bacterial strains from the same species may be due to the genome islands that are acquired through horizontal gene transfer (HGT). These genome islands are expected to possess some genes that may encode enzymes to resist the antimicrobial activity of silver nanoparticles. These silver nanoparticles may thus also be used to differentiate some bacterial strains within the same species due to variable silver resistance of these variants, which may not possible by simple biochemical tests.

  8. Large-scale bioreactor production of the herbicide-degrading Aminobacter sp. strain MSH1

    DEFF Research Database (Denmark)

    Schultz-Jensen, Nadja; Knudsen, Berith Elkær; Frkova, Zuzana;

    2014-01-01

    The Aminobacter sp. strain MSH1 has potential for pesticide bioremediation because it degrades the herbicide metabolite 2,6-dichlorobenzamide (BAM). Production of the BAM-degrading bacterium using aerobic bioreactor fermentation was investigated. A mineral salt medium limited for carbon...

  9. Genome sequence of Citrobacter sp. strain A1, a dye-degrading bacterium.

    Science.gov (United States)

    Chan, Giek Far; Gan, Han Ming; Rashid, Noor Aini Abdul

    2012-10-01

    Citrobacter sp. strain A1, isolated from a sewage oxidation pond, is a facultative aerobe and mesophilic dye-degrading bacterium. This organism degrades azo dyes efficiently via azo reduction and desulfonation, followed by the successive biotransformation of dye intermediates under an aerobic environment. Here we report the draft genome sequence of Citrobacter sp. A1.

  10. Genome Sequence of the Electrogenic Petroleum-Degrading Thalassospira sp. Strain HJ

    Science.gov (United States)

    Kiseleva, Larisa; Garushyants, Sofya K.; Briliute, Justina; Simpson, David J. W.; Goryanin, Igor

    2015-01-01

    We present the draft genome of the petroleum-degrading Thalassospira sp. strain HJ, isolated from tidal marine sediment. Knowledge of this genomic information will inform studies on electrogenesis and means to degrade environmental organic contaminants, including compounds found in petroleum. PMID:25977412

  11. Genome Sequence of Streptomyces viridosporus Strain T7A ATCC 39115, a Lignin-Degrading Actinomycete

    Science.gov (United States)

    Davis, Jennifer R.; Goodwin, Lynne; Teshima, Hazuki; Detter, Chris; Tapia, Roxanne; Han, Cliff; Huntemann, Marcel; Wei, Chia-Lin; Han, James; Chen, Amy; Kyrpides, Nikos; Mavrommatis, Kostas; Szeto, Ernest; Markowitz, Victor; Ivanova, Natalia; Mikhailova, Natalia; Ovchinnikova, Galina; Pagani, Ioanna; Pati, Amrita; Woyke, Tanja; Pitluck, Sam; Peters, Lin; Nolan, Matt; Land, Miriam

    2013-01-01

    We announce the availability of the genome sequence of Streptomyces viridosporus strain T7A ATCC 39115, a plant biomass-degrading actinomycete. This bacterium is of special interest because of its capacity to degrade lignin, an underutilized component of plants in the context of bioenergy. It has a full complement of genes for plant biomass catabolism. PMID:23833133

  12. Genome Sequence of Streptomyces viridosporus Strain T7A ATCC 39115, a Lignin-Degrading Actinomycete

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Jennifer R. [Brown University; Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Teshima, Hazuki [Los Alamos National Laboratory (LANL); Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Tapia, Roxanne [Los Alamos National Laboratory (LANL); Han, Cliff [Los Alamos National Laboratory (LANL); Huntemann, Marcel [U.S. Department of Energy, Joint Genome Institute; Wei, Chia-Lin [Los Alamos National Laboratory (LANL); Han, James [U.S. Department of Energy, Joint Genome Institute; Chen, Amy [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Szeto, Ernest [U.S. Department of Energy, Joint Genome Institute; Markowitz, Victor [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Mikhailova, Natalia [U.S. Department of Energy, Joint Genome Institute; Ovchinnikova, Galina [U.S. Department of Energy, Joint Genome Institute; Pagani, Ioanna [U.S. Department of Energy, Joint Genome Institute; Pati, Amrita [U.S. Department of Energy, Joint Genome Institute; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Peters, Lin [U.S. Department of Energy, Joint Genome Institute; Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Sello, Jason K. [Brown University

    2013-01-01

    We announce the availability of the genome sequence of Streptomyces viridosporus strain T7A ATCC 39115, a plant biomass- degrading actinomycete. This bacterium is of special interest because of its capacity to degrade lignin, an underutilized compo- nent of plants in the context of bioenergy. It has a full complement of genes for plant biomass catabolism.

  13. Biodegradation of Leonardite by an alkali-producing bacterial community and characterization of the degraded products.

    Science.gov (United States)

    Gao, Tong-Guo; Jiang, Feng; Yang, Jin-Shui; Li, Bao-Zhen; Yuan, Hong-Li

    2012-03-01

    In this study, three bacterial communities were obtained from 12 Leonardite samples with the aim of identifying a clean, effective, and economic technique for the dissolution of Leonardite, a type of low-grade coal, in the production of humic acid (HA). The biodegradation ability and characteristics of the degraded products of the most effective bacterial community (MCSL-2), which degraded 50% of the Leonardite within 21 days, were further investigated. Analyses of elemental composition, (13)C NMR, and Fourier transform infrared revealed that the contents of C, O, and aliphatic carbon were similar in biodegraded humic acid (bHA) and chemically (alkali) extracted humic acid (cHA). However, the N and carboxyl carbon contents of bHA was higher than that of cHA. Furthermore, a positive correlation was identified between the degradation efficiency and the increasing pH of the culture medium, while increases of manganese peroxidase and esterase activities were also observed. These data demonstrated that both alkali production and enzyme reactions were involved in Leonardite solubilization by MCSL-2, although the former mechanism predominated. No fungus was observed by microscopy. Only four bacterial phylotypes were recognized, and Bacillus licheniformis-related bacteria were identified as the main group in MCSL-2 by analysis of amplified 16S rRNA genes, thus demonstrating that Leonardite degradation ability has a limited distribution in bacteria. Hormone-like bioactivities of bHA were also detected. In this study, a bacterial community capable of Leonardite degradation was identified and the products characterized. These data implicate the use of such bacteria for the exploitation of Leonardite as a biofertilizer.

  14. Marine bacterium strain screening and pyrethroid insecticide-degrading efficiency analysis

    Science.gov (United States)

    Sun, Aili; Liu, Jinghua; Shi, Xizhi; Li, Dexiang; Chen, Jiong; Tang, Daojun

    2014-09-01

    A pyrethroid insecticide-degrading bacterium, strain HS-24, was isolated from an offshore seawater environment. The strain, which can degrade cypermethrin (CYP) and deltamethrin (DEL), was identified as Methylophaga sp. The optimal culture and degradation conditions for CYP and DEL by strain HS-24 is pH 7 at 28°C. Under optimum culture conditions, strain HS-24 exhibited a broad degradation concentration range of 100, 200, 400, 600, and 800 mg/L for CYP and DEL. The metabolic intermediates were analyzed by NMR, which provided strong evidence that CYP and DEL removal occurred mainly because of a biological process. The toxicity of the degradation products of strain HS-24 was studied simultaneously by measuring the light output of the luminescence bacterium. This demonstrated that the biodegradation ability of strain HS-24 significantly decreased the toxicity of CYP- and DEL-contaminated aquaculture seawater. Finally, the findings of this paper indicate that strain HS-24 is thus revealed as a biological agent for the remediation of marine aquatic environments.

  15. Isolation and characterization of aniline degradation slightly halophilic bacterium, Erwinia sp. Strain HSA 6.

    Science.gov (United States)

    Li, Junmin; Jin, Zexin; Yu, Binbin

    2010-07-20

    The isolated strain HSA6 is classified as Erwinia amylovora based on 16S rDNA sequence and the morphological and physiological properties. Strain HSA6 is the first reported E. amylovora in pure culture growing with aniline as sole electron donor and carbon source. The suitable pH for strain HSA6 is wide (from 5 to 11). Strain HSA6 is slightly halophilic with growth occurring at 0-10% (v/v) NaCl, and the suitable NaCl concentration for strain HSA6 is from 0% to 6%. The number of bacteria appeared to decrease with an increase in aniline concentration. The number of bacteria appeared to be constant as the wastewater concentration increased from 0% to 20%. However, the number of cells decreased with an increase in wastewater concentration from 30% to 50% and grew very slowly at 50%. The degradation rate of aniline was 100% at 0.5% aniline concentration after 24 h culture. The degradation rate of aniline was found to descend as the concentration of aniline increased from 0.5% to 3% and rose as the culture time increased. Strain HSA6 contains a plasmid with molecular weight higher than 42 kDA. Plasmid curing test and quantitative degradation test showed that strain requires the plasmid for aniline degradation. The gene cluster degrading aniline was determined in the plasmid by PCR amplification.

  16. Probiotic Activity of a Bacterial Strain Isolated from Ancient Permafrost Against Salmonella Infection in Mice.

    Science.gov (United States)

    Fursova, O; Potapov, V; Brouchkov, A; Pogorelko, G; Griva, G; Fursova, N; Ignatov, S

    2012-09-01

    Bacillus cereus strain F, collected from relict permafrost located in Siberia, was analyzed for probiotic activity in the mouse Salmonella enterica model. Viable bacterial cells were found in frozen soils taken at Mammoth Mountain in Yakutia from a depth below the level of seasonal thawing. Geological data indicated the absence of a thawing within millions of years of deposited soils, which helped to ensure the ancient origin of our sample. According to DNA analysis, bacterial cells collected from the relict permafrost appeared to be B. cereus strain F. The morphology of these bacteria was analyzed using atomic force microscopy. B. cereus strain F was assessed as a nonpathogenic bacterium by evaluation of its pathogenicity. A S. enterica model is described in mice after per oral inoculation and serves as a model for the human carrier state. Using this model, probiotic activity by the bacterial strain isolated from the ancient permafrost has been shown against Salmonella infection in mice.

  17. Plant secondary metabolite-induced shifts in bacterial community structure and degradative ability in contaminated soil.

    Science.gov (United States)

    Uhlik, Ondrej; Musilova, Lucie; Ridl, Jakub; Hroudova, Miluse; Vlcek, Cestmir; Koubek, Jiri; Holeckova, Marcela; Mackova, Martina; Macek, Tomas

    2013-10-01

    The aim of the study was to investigate how selected natural compounds (naringin, caffeic acid, and limonene) induce shifts in both bacterial community structure and degradative activity in long-term polychlorinated biphenyl (PCB)-contaminated soil and how these changes correlate with changes in chlorobiphenyl degradation capacity. In order to address this issue, we have integrated analytical methods of determining PCB degradation with pyrosequencing of 16S rRNA gene tag-encoded amplicons and DNA-stable isotope probing (SIP). Our model system was set in laboratory microcosms with PCB-contaminated soil, which was enriched for 8 weeks with the suspensions of flavonoid naringin, terpene limonene, and phenolic caffeic acid. Our results show that application of selected plant secondary metabolites resulted in bacterial community structure far different from the control one (no natural compound amendment). The community in soil treated with caffeic acid is almost solely represented by Proteobacteria, Acidobacteria, and Verrucomicrobia (together over 99 %). Treatment with naringin resulted in an enrichment of Firmicutes to the exclusion of Acidobacteria and Verrucomicrobia. SIP was applied in order to identify populations actively participating in 4-chlorobiphenyl catabolism. We observed that naringin and limonene in soil foster mainly populations of Hydrogenophaga spp., caffeic acid Burkholderia spp. and Pseudoxanthomonas spp. None of these populations were detected among 4-chlorobiphenyl utilizers in non-amended soil. Similarly, the degradation of individual PCB congeners was influenced by the addition of different plant compounds. Residual content of PCBs was lowest after treating the soil with naringin. Addition of caffeic acid resulted in comparable decrease of total PCBs with non-amended soil; however, higher substituted congeners were more degraded after caffeic acid treatment compared to all other treatments. Finally, it appears that plant secondary metabolites

  18. Proteomic analysis of nitrate-dependent acetone degradation by Alicycliphilus denitrificans strain BC

    NARCIS (Netherlands)

    Oosterkamp, M.J.; Boeren, S.; Atashgahi, S.; Plugge, C.M.; Schaap, P.J.; Stams, A.J.M.

    2015-01-01

    Alicycliphilus denitrificans strain BC grows anaerobically on acetone with nitrate as electron acceptor. Comparative proteomics of cultures of A. denitrificans strain BC grown on either acetone or acetate with nitrate was performed to study the enzymes involved in the acetone degradation pathway. In

  19. Complete Genome Sequence of the Fenitrothion-Degrading Burkholderia sp. Strain YI23

    OpenAIRE

    Lim, Jong Sung; Choi, Beom Soon; Choi, Ah Young; Kim, Kyung Duk; Kim, Dong In; Choi, Ik Young; Ka, Jong-Ok

    2012-01-01

    Burkholderia species are ubiquitous in soil environments. Many Burkholderia species isolated from various environments have the potential to biodegrade man-made chemicals. Burkholderia sp. strain YI23 was isolated from a golf course soil and identified as a fenitrothion-degrading bacterium. In this study, we report the complete genome sequence of Burkholderia sp. strain YI23.

  20. Bacterial degradation of synthetic and kraft lignin by axenic and mixed culture and their metabolic products.

    Science.gov (United States)

    Chandra, Ram; Bharagava, Ram Naresh

    2013-11-01

    Pulp paper mill effluent has high pollution load due to presence of lignin and its derivatives as major colouring and polluting constituents. In this study, two lignin degrading bacteria IITRL1 and IITRSU7 were isolated and identified as Citrobacter freundii (FJ581026) and Citrobacter sp. (FJ581023), respectively. In degradation study by axenic and mixed culture, mixed bacterial culture was found more effective compared to axenic culture as it decolourized 85 and 62% of synthetic and kraft lignin whereas in axenic conditions, bacterium IITRL1 and IITRSU7 decolourized 61 and 64% synthetic and 49 and 54% kraft lignin, respectively. Further, the mixed bacterial culture also showed the removal of 71, 58% TOC; 78, 53% AOX; 70, 58% COD and 74, 58% lignin from synthetic and kraft lignin, respectively. The ligninolytic enzyme was characterized as manganese peroxidase by SDS-PAGE yielding a single band of 43 KDa. The HPLC analysis of degraded samples showed reduction as well as shifting of peaks compared to control indicating the degradation as well as transformation of compounds. Further, in GC-MS analysis of synthetic and kraft lignin degraded samples, hexadecanoic acid was found as recalcitrant compounds while 2,4,6-trichloro-phenol, 2,3,4,5-tetrachloro-phenol and pentachloro-phenol were detected as new metabolites.

  1. Fungal hyphae stimulate bacterial degradation of 2,6-dichlorobenzamide (BAM)

    DEFF Research Database (Denmark)

    Knudsen, Berith Elkær; Ellegaard-Jensen, Lea; Albers, Christian Nyrop

    2013-01-01

    Abstract Introduction of specific degrading microorganisms into polluted soil or aquifers is a promising remediation technology provided that the organisms survive and spread in the environment. We suggest that consortia, rather than single strains, may be better suited to overcome these challenges...

  2. Kinetics study of pyridine biodegradation by a novel bacterial strain, Rhizobium sp. NJUST18.

    Science.gov (United States)

    Shen, Jinyou; Zhang, Xin; Chen, Dan; Liu, Xiaodong; Zhang, Libin; Sun, Xiuyun; Li, Jiansheng; Bi, Huiping; Wang, Lianjun

    2014-06-01

    Biodegradation of pyridine by a novel bacterial strain, Rhizobium sp. NJUST18, was studied in batch experiments over a wide concentration range (from 100 to 1,000 mg l(-1)). Pyridine inhibited both growth of Rhizobium sp. NJUST18 and biodegradation of pyridine. The Haldane model could be fitted to the growth kinetics data well with the kinetic constants μ* = 0.1473 h(-1), K s = 793.97 mg l(-1), K i = 268.60 mg l(-1) and S m = 461.80 mg l(-1). The true μ max, calculated from μ*, was found to be 0.0332 h(-1). Yield coefficient Y X/S depended on S i and reached a maximum of 0.51 g g(-1) at S i of 600 mg l(-1). V max was calculated by fitting the pyridine consumption data with the Gompertz model. V max increased with initial pyridine concentration up to 14.809 mg l(-1) h(-1). The q S values, calculated from [Formula: see text], were fitted with the Haldane equation, yielding q Smax = 0.1212 g g(-1) h(-1) and q* = 0.3874 g g(-1) h(-1) at S m' = 507.83 mg l(-1), K s' = 558.03 mg l(-1), and K i' = 462.15 mg l(-1). Inhibition constants for growth and degradation rate value were in the same range. Compared with other pyridine degraders, μ max and S m obtained for Rhizobium sp. NJUST18 were relatively high. High K i and K i' values and extremely high K s and K s' values indicated that NJUST18 was able to grow on pyridine within a wide concentration range, especially at relatively high concentrations.

  3. Isolation of a Pseudomonas Stutzeri strain that degrades1, 2, 4-trichlorobenzene and characterization of its degradative plasmid

    Institute of Scientific and Technical Information of China (English)

    Lei SONG; Hui WANG; Hanchang SHI; Hongying HU

    2008-01-01

    The genetic information encoding metabolic pathways for xenobiotic compounds in bacteria often resides on catabolic plasmids. The aim of the present work was to know the location of the genes for degrading 1, 2, 4-trichlorobenzen. In this paper a 1, 2, 4-trichlorobenzene-degrading strain THSL-1 was isolated from the soil of Tianjin Chemical Plant using 1, 2, 4-trichlorobenzene as the sole carbon source. The strain was identified as Pseudomonas stutzeri through morphologic survey and 16S rDNA sequence determination. A plasmid was discovered from strain THSL-1 by using the alkali lysis method. When the plasmid was transformed into E. coli. JM109 by the CaCl2 method, the transformant could grow using 1, 2, 4-trichlorobenzene as the sole carbon source and had the degradation function of 1, 2, 4-trichlorobenzene. Therefore, it could be deemed that the plasmid carried the degradative genes of 1, 2, 4-trichlorobenzene. The average size of the plasmid was finally determined to be 40.2 Kb using selectively three kinds of restricted inscribed enzymes (HindIII, BamHI, and XholI) for single cutting and double cutting the plasmid pTHSL-1, respectively.

  4. Enhanced caffeine degradation by immobilised cells of Leifsonia sp. strain SIU.

    Science.gov (United States)

    Ibrahim, Salihu; Shukor, Mohd Y; Syed, Mohd A; Johari, Wan L W; Shamaan, Nor A; Sabullah, Mohd K; Ahmad, Siti A

    2016-01-01

    In a previous study, we isolated Leifsonia sp. strain SIU, a new bacterium from agricultured soil. The bacterium was tested for its ability to degrade caffeine. The isolate was encapsulated in gellan gum and its ability to degrade caffeine was compared with the free cells. The optimal caffeine degradation was attained at a gellan gum concentration of 0.75% (w/v), a bead size of 4 mm diameter, and 250 beads per 100 mL of medium. At a caffeine concentration of 0.1 g/L, immobilised cells of the strain SIU degraded caffeine within 9 h, which is faster when compared to the case of free cells, in which it took 12 h to degrade. The immobilised cells degraded caffeine completely within 39 and 78 h at 0.5 and 1.0 g/L, while the free cells took 72 and 148 h at 0.5 and 1.0 g/L, respectively. At higher caffeine concentrations, immobilised cells exhibited a higher caffeine degradation rate. At concentrations of 1.5 and 2.0 g/L, caffeine-degrading activities of both immobilised and free cells were inhibited. The immobilised cells showed no loss in caffeine-degrading activity after being used repeatedly for nine 24-h cycles. The effect of heavy metals on immobilised cells was also tested. This study showed an increase in caffeine degradation efficiency when the cells were encapsulated in gellan gum.

  5. Fucoidan-degrading fungal strains : screening, morphometric evaluation, and influence of medium composition

    OpenAIRE

    Rodríguez-Jasso, Rosa María; Mussatto, Solange I.; Pastrana, Lorenzo; Aguilar Gonzalez, Cristobal Noé; Teixeira, J.A.

    2010-01-01

    Ten different fungal strains from the genus Aspergillus, Penicillium, and Mucor were screened for fucoidan hydrolyzing ability aiming to find microorganisms able to produce sulfated fucan-degrading enzymes. Screening was carried out by measuring the strains kinetic and morphometric behavior over plate assays using Laminaria japonica fucoidan as only carbon source, testing three nitrogen sources (urea, peptone, and sodium nitrate). The selected fungal strains were subsequently u...

  6. Raman discrimination of bacterial strains using multilayered microcavity substrates

    Science.gov (United States)

    Sharma, Shiv K.; Dykes, Ava C.; Misra, Anupam K.; Kamemoto, Lori E.; Bates, David E.

    2011-05-01

    Surface-enhanced Raman scattering (SERS) utilizing colloidal silver and gold has been demonstrated to provide a rapid means of measuring the Raman spectra of microorganisms in the fingerprint region. In this study, we have introduced microcavity substrates coated with alternating layers of silver and gold thin films for measuring the Raman spectra of four strains of E. coli. These microcavitiy substrates have been prepared by placing glass microspheres between two polished aluminum substrates and pressing them together using a standard lab press. After removing the glass microspheres from the substrates, the substrates have been coated with 15 to 70 nm thick films of chromium, silver and gold in a precise order. The cavities were evaluated for SERS enhancement by measuring Raman spectra of dilute rhodamine 6G (R6G) down to 10-8 M. With these microcavities, we have investigated the SERS spectra of four chemically competent strains of E. coli (One Shot OmniMAX 2-T1, Mach1-T1, Stbl3, and TOP10). Replicate SERS spectra of all the four e-coli strains show excellent reproducibility. Visual examination of the spectra, however, reveals differences in the spectra of these strains. To confirm this observation, we have used multivariate analysis for positive identification and discrimination between the strains.

  7. Arginine deiminase pathway genes and arginine degradation variability in Oenococcus oeni strains.

    Science.gov (United States)

    Araque, Isabel; Gil, Joana; Carreté, Ramon; Constantí, Magda; Bordons, Albert; Reguant, Cristina

    2016-03-01

    Trace amounts of the carcinogenic ethyl carbamate can appear in wine as a result of a reaction between ethanol and citrulline, which is produced from arginine degradation by some bacteria used in winemaking. In this study, arginine deiminase (ADI) pathway genes were evaluated in 44 Oenococcus oeni strains from wines originating from several locations in order to establish the relationship between the ability of a strain to degrade arginine and the presence of related genes. To detect the presence of arc genes of the ADI pathway in O. oeni, pairs of primers were designed to amplify arcA, arcB, arcC and arcD1 sequences. All strains contained these four genes. The same primers were used to confirm the organization of these genes in an arcABCD1 operon. Nevertheless, considerable variability in the ability to degrade arginine among these O. oeni strains was observed. Therefore, despite the presence of the arc genes in all strains, the expression patterns of individual genes must be strain dependent and influenced by the different wine conditions. Additionally, the presence of arc genes was also determined in the 57 sequenced strains of O. oeni available in GenBank, and the complete operon was found in 83% of strains derived from wine. The other strains were found to lack the arcB, arcC and arcD genes, but all contained sequences homologous to arcA, and some of them had also ADI activity.

  8. Comparative biocidal activity of peracetic acid, benzalkonium chloride and ortho-phthalaldehyde on 77 bacterial strains.

    Science.gov (United States)

    Bridier, A; Briandet, R; Thomas, V; Dubois-Brissonnet, F

    2011-07-01

    Despite numerous reports on biocide activities, it is often difficult to have a reliable and relevant overview of bacterial resistance to disinfectants because each work challenges a limited number of strains and tested methods are often different. The aim of this study was to evaluate the bactericidal activity of three different disinfectants commonly used in industrial or medical environments (peracetic acid, benzalkonium chloride and ortho-phthalaldehyde) against 77 bacterial strains from different origins using one standard test method (NF EN 1040). Results highlight the existence of high interspecific variability of resistance to disinfectants and, contrary to widespread belief, Gram-positive strains generally appeared more resistant than Gram-negative strains. Resistance was also variable among strains of the same species such as Bacillus subtilis to peracetic acid, Pseudomonas aeruginosa to benzalkonium chloride and Staphylococcus aureus to ortho-phthalaldehyde.

  9. Filter Paper Degrading Ability of a Trichoderma Strain With Multinucleate Conidia

    Science.gov (United States)

    Toyama, Hideo; Yano, Makiko; Hotta, Takeshi; Toyama, Nobuo

    The multinucleate conidia were produced from the green mature conidia of Trichoderma reesei Rut C-30 strain by colchicine treatment. The strain with higher Filter paper degrading ability was selected among those conidia using a double layer selection medium. The selected strain, JS-2 was able to collapse the filter paper within 15 min but the original strain took 25 min to collapse it completely. Moreover, the amount of reducing sugar in the L-type glass tube of the strain, JS-2, was greater than that of the original strain. The Avicel, CMC-Na, and Salicin hydrolyzing activity of the strain, JS-2, increased 2.1 times, 1.2 times, and 3.6 times higher than that of the original strain.

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

    Directory of Open Access Journals (Sweden)

    Phillip Trefz

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

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

    Science.gov (United States)

    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.

  12. Robust hydrocarbon degradation and dynamics of bacterial communities during nutrient-enhanced oil spill bioremediation.

    Science.gov (United States)

    Röling, Wilfred F M; Milner, Michael G; Jones, D Martin; Lee, Kenneth; Daniel, Fabien; Swannell, Richard J P; Head, Ian M

    2002-11-01

    Degradation of oil on beaches is, in general, limited by the supply of inorganic nutrients. In order to obtain a more systematic understanding of the effects of nutrient addition on oil spill bioremediation, beach sediment microcosms contaminated with oil were treated with different levels of inorganic nutrients. Oil biodegradation was assessed respirometrically and on the basis of changes in oil composition. Bacterial communities were compared by numerical analysis of denaturing gradient gel electrophoresis (DGGE) profiles of PCR-amplified 16S rRNA genes and cloning and sequencing of PCR-amplified 16S rRNA genes. Nutrient amendment over a wide range of concentrations significantly improved oil degradation, confirming that N and P limited degradation over the concentration range tested. However, the extent and rate of oil degradation were similar for all microcosms, indicating that, in this experiment, it was the addition of inorganic nutrients rather than the precise amount that was most important operationally. Very different microbial communities were selected in all of the microcosms. Similarities between DGGE profiles of replicate samples from a single microcosm were high (95% +/- 5%), but similarities between DGGE profiles from replicate microcosms receiving the same level of inorganic nutrients (68% +/- 5%) were not significantly higher than those between microcosms subjected to different nutrient amendments (63% +/- 7%). Therefore, it is apparent that the different communities selected cannot be attributed to the level of inorganic nutrients present in different microcosms. Bioremediation treatments dramatically reduced the diversity of the bacterial community. The decrease in diversity could be accounted for by a strong selection for bacteria belonging to the alkane-degrading Alcanivorax/Fundibacter group. On the basis of Shannon-Weaver indices, rapid recovery of the bacterial community diversity to preoiling levels of diversity occurred. However, although

  13. Kinetic and morphometric evaluation of fucoidan‐degrading fungal strains

    OpenAIRE

    Rodríguez-Jasso, Rosa María; Mussatto, Solange I.; Pastrana, Lorenzo; Aguilar Gonzalez, Cristobal Noé; Teixeira, J.A.

    2009-01-01

    Fucoidan is a sulfated fucose hetero‐polysaccharide found in brown algae. This compound has a wide variety of biological activities including anticoagulant, antithrombotic, antitumoral and antiviral (Alexeeva et al. 2002; Ellouali et al. 1993; McClure et al. 1992). Specific enzymes able to degrade fucoidan matrix are important tools to establish structural characteristics and biological functions of this polysaccharide. Such enzymes, called fucoidanases, have been only isolated fr...

  14. Degradation of fluoroanilines by the wild strain Labrys portucalensis

    OpenAIRE

    Amorim, Catarina L.; Carvalho, Maria F.; Afonso, Carlos M. M.; Castro, Paula M. L.

    2009-01-01

    Aromatic amine compounds, many of them with halogenated substituents, constitute a major class of environmental pollutants that have been released into soil and water due to extensive use in industries and agriculture. Biodegradation has been found to be a major route for the removal of this kind of toxic and recalcitrant pollutants from the environment. Whereas the degradation of mono- and dichlorinated anilines has been studied, very little is known about fluorinated anilines. Therefore,...

  15. Rhodococcus opacus strain RW, a resorcinol- degrading bacterium ...

    African Journals Online (AJOL)

    Owner

    results isolate RW is proposed as a new strain in the species R. opacus. The ability of the ... environments contaminated by such or related compounds. Key words: .... used in the PCR to amplify the 16S rRNA gene with primers 27F .... It has been suggested that biological control of .... The biology and genetics of the genus.

  16. Textile dye degradation by bacterial consortium and subsequent toxicological analysis of dye and dye metabolites using cytotoxicity, genotoxicity and oxidative stress studies.

    Science.gov (United States)

    Phugare, Swapnil S; Kalyani, Dayanand C; Patil, Asmita V; Jadhav, Jyoti P

    2011-02-15

    The present study aims to evaluate Red HE3B degrading potential of developed microbial consortium SDS using two bacterial cultures viz. Providencia sp. SDS (PS) and Pseudomonas aeuroginosa strain BCH (PA) originally isolated from dye contaminated soil. Consortium was found to be much faster for decolorization and degradation of Red HE3B compared to the individual bacterial strain. The intensive metabolic activity of these strains led to 100% decolorization of Red HE3B (50 mg l(-1)) with in 1h. Significant induction of various dye decolorizing enzymes viz. veratryl alcohol oxidase, laccase, azoreductase and DCIP reductase compared to control, point out towards their involvement in overall decolorization and degradation process. Analytical studies like HPLC, FTIR and GC-MS were used to scrutinize the biodegradation process. Toxicological studies before and after microbial treatment was studied with respect to cytotoxicity, genotoxicity, oxidative stress, antioxidant enzyme status, protein oxidation and lipid peroxidation analysis using root cells of Allium cepa. Toxicity analysis with A. cepa signifies that dye Red HE3B exerts oxidative stress and subsequently toxic effect on the root cells where as biodegradation metabolites of the dye are relatively less toxic in nature. Phytotoxicity studies also indicated that microbial treatment favors detoxification of Red HE3B.

  17. Degradation of pyrene, benz[a]anthracene, and benzo[a]pyrene by Mycobacterium sp. strain RJGII-135, isolated from a former coal gasification site.

    Science.gov (United States)

    Schneider, J; Grosser, R; Jayasimhulu, K; Xue, W; Warshawsky, D

    1996-01-01

    The degradation of three polycyclic aromatic hydrocarbons (PAH), pyrene (PYR), benz[a]anthracene (BAA), and benzo[a]pyrene (BaP), by Mycobacterium sp. strain RJGII-135 was studied. The bacterium was isolated from an abandoned coal gasification site soil by analog enrichment techniques and found to mineralize [14C]PYR. Further degradation studies with PYR showed three metabolites formed by Mycobacterium sp. strain RJGII-135, including 4,5-phenanthrene-dicarboxylic acid not previously isolated, 4-phenanthrene-carboxylic acid, and 4,5-pyrene-dihydrodiol. At least two dihydrodiols, 5,6-BAA-dihydrodiol and 10,11-BAA-dihydrodiol, were confirmed by high-resolution mass spectral and fluorescence analyses as products of the biodegradation of BAA by Mycobacterium sp. strain RJGII-135. Additionally, a cleavage product of BAA was also isolated. Mass spectra and fluorescence data support two different routes for the degradation of BaP by Mycobacterium sp. strain RJGII-135. The 7,8-BaP-dihydrodiol and three cleavage products of BaP, including 4,5-chrysene-dicarboxylic acid and a dihydro-pyrene-carboxylic acid metabolite, have been isolated and identified as degradation products formed by Mycobacterium sp. strain RJGII-135. These latter results represent the first example of the isolation of BaP ring fission products formed by a bacterial isolate. We propose that while this bacterium appears to attack only one site of the PYR molecule, it is capable of degrading different sites of the BAA and BaP molecules, and although the sites of attack may be different, the ability of this bacterium to degrade these PAH is well supported. The proposed pathways for biodegradation of these compounds by this Mycobacterium sp. strain RJGII-135 support the dioxygenase enzymatic processes reported previously for other bacteria. Microorganisms like Mycobacterium sp. strain RJGII-135 will be invaluable in attaining the goal of remediation of sites containing mixtures of these PAH.

  18. [BACILLUS STRAINS'S SCREENING--ACTIVE ANTAGONISTS OF BACTERIAL AND FUNGAL PHYTOPATHOGENS].

    Science.gov (United States)

    Grabova, A Yu; Dragovoz, I V; Kruchkova, L A; Pasichnik, L A; Avdeeva, L V

    2015-01-01

    Antagonistic activity 100 strains of Bacillus bacteria towards to museum and actual strains of phytopathogenic bacteria and fungy was defined. Relation between level of antagonistic activity to phytopathogenic bacteria and genus accessory of the last was shown. The medium level of antagonism to fungal phytopathogens at 30% of the studied strains of Bacillus bacteria was shown. 5 strains of Bacillus sp. with high and medium levels of antagonism to phytopathogens bacterial and fungy nature was selected and considered as perspective for creation of biological preparations for plant protection.

  19. Experimental insights into the importance of aquatic bacterial community composition to the degradation of dissolved organic matter

    DEFF Research Database (Denmark)

    Logue, J.B.; Stedmon, Colin; Kellerman, A.M.

    2016-01-01

    and ecosystem functioning in that differently structured aquatic bacterial communities differed in their degradation of terrestrially derived DOM. Although the same amount of carbon was processed, both the temporal pattern of degradation and the compounds degraded differed among communities. We, moreover...... insight into how the structure of bacterial communities may affect processes of biogeochemical significance......Bacteria play a central role in the cycling of carbon, yet our understanding of the relationship between the taxonomic composition and the degradation of dissolved organic matter (DOM) is still poor. In this experimental study, we were able to demonstrate a direct link between community composition...

  20. Strain induced irreversible critical current degradation in highly dense Bi-2212 round wire

    CERN Document Server

    Bjoerstad, R; Rikel, M.O.; Ballarino, A; Bottura, L; Jiang, J; Matras, M; Sugano, M; Hudspeth, J; Di Michiel, M

    2015-01-01

    The strain induced critical current degradation of overpressure processed straight Bi 2212/Ag wires has been studied at 77 K in self-field. For the first time superconducting properties, lattice distortions, composite wire stress and strain have been measured simultaneously in a high energy synchrotron beamline. A permanent Ic degradation of 5% occurs when the wire strain exceeds 0.60%. At a wire strain of about 0.65% a drastic n value and Ic reduction occur, and the composite stress and the Bi-2212 lattice parameter reach a plateau, indicating Bi-2212 filament fracturing. The XRD measurements show that Bi-2212 exhibits linear elastic behaviour up to the irreversible strain limit.

  1. Use of colony-based bacterial strain typing for tracking the fate of Lactobacillus strains during human consumption

    Directory of Open Access Journals (Sweden)

    Drevinek Pavel

    2009-12-01

    Full Text Available Abstract Background The Lactic Acid Bacteria (LAB are important components of the healthy gut flora and have been used extensively as probiotics. Understanding the cultivable diversity of LAB before and after probiotic administration, and being able to track the fate of administered probiotic isolates during feeding are important parameters to consider in the design of clinical trials to assess probiotic efficacy. Several methods may be used to identify bacteria at the strain level, however, PCR-based methods such as Random Amplified Polymorphic DNA (RAPD are particularly suited to rapid analysis. We examined the cultivable diversity of LAB in the human gut before and after feeding with two Lactobacillus strains, and also tracked the fate of these two administered strains using a RAPD technique. Results A RAPD typing scheme was developed to genetically type LAB isolates from a wide range of species, and optimised for direct application to bacterial colony growth. A high-throughput strategy for fingerprinting the cultivable diversity of human faeces was developed and used to determine: (i the initial cultivable LAB strain diversity in the human gut, and (ii the fate of two Lactobacillus strains (Lactobacillus salivarius NCIMB 30211 and Lactobacillus acidophilus NCIMB 30156 contained within a capsule that was administered in a small-scale human feeding study. The L. salivarius strain was not cultivated from the faeces of any of the 12 volunteers prior to capsule administration, but appeared post-feeding in four. Strains matching the L. acidophilus NCIMB 30156 feeding strain were found in the faeces of three volunteers prior to consumption; after taking the Lactobacillus capsule, 10 of the 12 volunteers were culture positive for this strain. The appearance of both Lactobacillus strains during capsule consumption was statistically significant (p Conclusion We have shown that genetic strain typing of the cultivable human gut microbiota can be

  2. Isolation of a naphthalene-degrading strain from activated sludge and bioaugmentation with it in a MBR treating coal gasification wastewater.

    Science.gov (United States)

    Xu, Peng; Ma, Wencheng; Han, Hongjun; Jia, Shengyong; Hou, Baolin

    2015-03-01

    A highly effective naphthalene-degrading bacterial strain was isolated from acclimated activated sludge from a coal gasification wastewater plant, and identified as a Streptomyces sp., designated as strain QWE-35. The optimal pH and temperature for naphthalene degradation were 7.0 and 35°C. The presence of additional glucose and methanol significantly increased the degradation efficiency of naphthalene. The strain showed tolerance to the toxicity of naphthalene at a concentration as great as 200 mg/L. The Andrews mode could be fitted to the degradation kinetics data well over a wide range of initial naphthalene concentrations (10-200 mg/L), with kinetic values q max = 0.84 h(-1), K s = 40.39 mg/L, and K i = 193.76 mg/L. Metabolic intermediates were identified by gas chromatography and mass spectrometry, allowing a new degradation pathway for naphthalene to be proposed for the first time. Strain QWE-35 was added into a membrane bioreactor (MBR) to enhance the treatment of real coal gasification wastewater. The results showed that the removal of chemical oxygen demand and total nitrogen were similar between bioaugmented and non-bioaugmented MBRs, however, significant removal of naphthalene was obtained in the bioaugmented reactor. The findings suggest a potential bioremediation role of Streptomyces sp. QWE-35 in the removal of naphthalene from wastewaters.

  3. Specificity of monoclonal antibodies to strains of Dickeya sp. that cause bacterial heart rot of pineapple.

    Science.gov (United States)

    Peckham, Gabriel D; Kaneshiro, Wendy S; Luu, Van; Berestecky, John M; Alvarez, Anne M

    2010-10-01

    During a severe outbreak of bacterial heart rot that occurred in pineapple plantations on Oahu, Hawaii, in 2003 and years following, 43 bacterial strains were isolated from diseased plants or irrigation water and identified as Erwinia chrysanthemi (now Dickeya sp.) by phenotypic, molecular, and pathogenicity assays. Rep-PCR fingerprint patterns grouped strains from pineapple plants and irrigation water into five genotypes (A-E) that differed from representatives of other Dickeya species, Pectobacterium carotovorum and other enteric saprophytes isolated from pineapple. Monoclonal antibodies produced following immunization of mice with virulent type C Dickeya sp. showed only two specificities. MAb Pine-1 (2D11G1, IgG1 with kappa light chain) reacted to all 43 pineapple/water strains and some reference strains (D. dianthicola, D. chrysanthemi, D. paradisiaca, some D. dadantii, and uncharacterized Dickeya sp.) but did not react to reference strains of D. dieffenbachiae, D. zeae, or one of the two Malaysian pineapple strains. MAb Pine-2 (2A7F2, IgG3 with kappa light chain) reacted to all type B, C, and D strains but not to any A or E strains or any reference strains except Dickeya sp. isolated from Malaysian pineapple. Pathogenicity tests showed that type C strains were more aggressive than type A strains when inoculated during cool months. Therefore, MAb Pine-2 distinguishes the more virulent type C strains from less virulent type A pineapple strains and type E water strains. MAbs with these two specificities enable development of rapid diagnostic tests that will distinguish the systemic heart rot pathogen from opportunistic bacteria associated with rotted tissues. Use of the two MAbs in field assays also permits the monitoring of a known subpopulation and provides additional decision tools for disease containment and management practices.

  4. Differences in biomass degradation between newly isolated environmental strains of Clostridium thermocellum and heterogeneity in the size of the cellulosomal scaffoldin.

    Science.gov (United States)

    Koeck, D E; Koellmeier, T; Zverlov, V V; Liebl, W; Schwarz, W H

    2015-09-01

    Cellulolytic bacterial strains with high activity were isolated from cellulose degrading enrichment cultures derived from thermophilic biogas plants and environmental samples. The 16S rRNA gene sequences of the strains revealed >99.8% sequence identity and affiliation with the species Clostridium thermocellum. The strains differed in their ability to degrade crystalline cellulose, especially at an elevated temperature of up to 67 °C and at relatively low pH values (pH 6.5). To evaluate the influence of amino acid sequences on the discrepancies in cellulose degradation efficacy, the gene for the major cellulosomal component CelR was sequenced for all strains. The sequences were found to be almost identical (>99%). In contrast, the cellulosomal scaffoldin gene cipA showed more differences in the amino acid sequence and contained 8 or 9 cohesin modules, which indicated a different size of the cellulosome depending on the isolate. Based on MALDI-TOF MS analysis the relative abundance of important cellulosomal enzyme classes was determined. The strains with better biomass degradation properties (BC1 and NB2) had a significantly higher fraction of xylanases.

  5. Transcriptional profiling of genes involved in n-hexadecane compounds assimilation in the hydrocarbon degrading Dietzia cinnamea P4 strain

    NARCIS (Netherlands)

    Procopio, Luciano; Pereira e Silva, Michele de Cassia; van Elsas, Jan Dirk; Seldin, Lucy

    2013-01-01

    The petroleum-derived degrading Dietzia cinnamea strain P4 recently had its genome sequenced and annotated. This allowed employing the data on genes that are involved in the degradation of n-alkanes. To examine the physiological behavior of strain P4 in the presence of n-alkanes, the strain was grow

  6. Formyl-methionine as a degradation signal at the N-termini of bacterial proteins

    Science.gov (United States)

    Piatkov, Konstantin I.; Vu, Tri T. M.; Hwang, Cheol-Sang; Varshavsky, Alexander

    2015-01-01

    In bacteria, all nascent proteins bear the pretranslationally formed N-terminal formyl-methionine (fMet) residue. The fMet residue is cotranslationally deformylated by a ribosome-associated deformylase. The formylation of N-terminal Met in bacterial proteins is not strictly essential for either translation or cell viability. Moreover, protein synthesis by the cytosolic ribosomes of eukaryotes does not involve the formylation of N-terminal Met. What, then, is the main biological function of this metabolically costly, transient, and not strictly essential modification of N terminal Met, and why has Met formylation not been eliminated during bacterial evolution? One possibility is that the similarity of the formyl and acetyl groups, their identical locations in N terminally formylated (Nt formylated) and Nt-acetylated proteins, and the recently discovered proteolytic function of Nt-acetylation in eukaryotes might also signify a proteolytic role of Nt formylation in bacteria. We addressed this hypothesis about fMet based degradation signals, termed fMet/N-degrons, using specific E. coli mutants, pulse-chase degradation assays, and protein reporters whose deformylation was altered, through site-directed mutagenesis, to be either rapid or relatively slow. Our findings strongly suggest that the formylated N-terminal fMet can act as a degradation signal, largely a cotranslational one. One likely function of fMet/N-degrons is the control of protein quality. In bacteria, the rate of polypeptide chain elongation is nearly an order of magnitude higher than in eukaryotes. We suggest that the faster emergence of nascent proteins from bacterial ribosomes is one mechanistic and evolutionary reason for the pretranslational design of bacterial fMet/N degrons, in contrast to the cotranslational design of analogous Ac/N degrons in eukaryotes. PMID:26866044

  7. Biochemical diversity of the bacterial strains and their biopolymer producing capabilities in wastewater sludge.

    Science.gov (United States)

    More, T T; Yan, S; John, R P; Tyagi, R D; Surampalli, R Y

    2012-10-01

    The biochemical characterization of 13 extracellular polymeric substances (EPS) producing bacterial strains were carried out by BIOLOG. The bacterial strains were cultured in sterilized sludge for EPS production. Flocculation and dewatering capabilities of produced EPS (broth, crude slime and capsular) were examined using kaolin suspension combined with calcium (150 mg of Ca(2+)/L of kaolin suspension). BIOLOG revealed that there were 9 Bacillus, 2 Serratia and 2 Yersinia species. Most of these bacterial strains had the capability to utilize wide spectrum of carbon and nitrogen sources. EPS concentration of more than 1g/L was produced by most of the bacterial strains. Concentration of EPS produced by different Bacillus strains was higher than that of Serratia and Yersinia. Broth EPS revealed flocculation activity more than 75% for Bacillus sp.7, Bacillus sp.4 and Bacillus sp.6, respectively. Flocculation activity higher than 75% was attained using very low concentrations of broth EPS (1.12-2.70 mg EPS/g SS).

  8. Biodecolorization of Reactive Black-5 by a metal and salt tolerant bacterial strain Pseudomonas sp. RA20 isolated from Paharang drain effluents in Pakistan.

    Science.gov (United States)

    Hussain, Sabir; Maqbool, Zahid; Ali, Shafaqat; Yasmeen, Tahira; Imran, Muhammad; Mahmood, Faisal; Abbas, Farhat

    2013-12-01

    Discharge of untreated azo dyes contaminated textile wastewater into soil and water bodies causes severe contamination. The present study was conducted to isolate dye degrading bacterial strains from a textile industry wastewater carrying drain in the neighborhood of Faisalabad, Pakistan. Seventy six bacterial strains were initially isolated and was screened using liquid mineral salts medium spiked with Reactive Black-5 azo dye. The strain RA20 was found to be the most efficient azo dye degrading bacterial isolate and was identified by amplifying and sequencing its 16S rRNA. Analysis indicated that this strain belonged to genus Pseudomonas and was designated as Pseudomonas sp. RA20. It had the highest decolorization activity at pH 8 and 25 °C incubation temperature under static conditions using yeast extract as an additional C source. This strain was also effective in decolorizing structurally related other reactive dyes including Reactive Orange 16, Reactive Yellow 2 and Reactive Red 120 but with varying efficacy. RA20 decolorized Reactive Black-5 significantly in the presence of up to 30 g L⁻¹ NaCl; however, the decolorization rate was significantly (p≤0.05) reduced beyond this salt concentration. Moreover, this bacterial strain also exhibited moderate tolerance to different heavy metals including zinc (Zn), cadmium (Cd), chromium (Cr), lead (Pb) and copper (Cu). RA20 also decolorized Reactive Black-5 in the presence of a mixture of the selected heavy metals depending upon their concentrations. This study highlights the importance of Pseudomonas sp. RA20 as a prospective biological resource for bioremediation of water and soils contaminated with azo dyes.

  9. Role of nutrients in the utilization of polycyclic aromatic hydrocarbons by halotolerant bacterial strain

    Institute of Scientific and Technical Information of China (English)

    Pugazhcndi Arulazhagan; Namsivayam Vasudevan

    2011-01-01

    A halotolerant bacterial strain VA1 isolated from marine environment was studied for its ability to utilize polycylic aromatic hydrocarbons (PAHs) under saline condition.Anthracene and pyrene were used as representatives for the utilization of PAH by the bacterial strain.Glucose and sodium citrate were used as additional carbon sources to enhance the PAH utilization.The strain VA1was able to utilize anthracene (73%) and pyrene (66%) without any additional substrate.In the presence of additional carbon sources (glucose/sodium citrate) the utilization of PAH was faster.PAH was utilized faster by VA1 in the presence of glucose than sodium citrate.The stain utilized 87% and 83% of anthracene and pyrene with glucose as carbon source and with sodium citrate the strain utilized 81%and 76% respectively in 4 days.Urea as an alternative source of nitrogen also enhanced the utilization of PAHs (anthracene and pyrene)by the bacterial strain up to 88% and 84% in 4 days.Sodium nitrate as nitrogen source was not able to enhance the PAH utilization rate.Phenotypic and phlyogenetic analysis proved that the PAHs utilizing halotolerant strain VA1 belongs to Ochrobactrum sp.

  10. Evolution of a degradative bacterial consortium during the enrichment of naphtha solvent.

    Science.gov (United States)

    Cavalca, L; Confalonieri, A; Larcher, S; Andreoni, V

    2000-06-01

    A microbial mixed culture able to degrade naphtha solvent, a model of hydrocarbon aromatic mixture, was isolated from a hydrocarbon-polluted soil. Composition of the population was monitored by phenotypic and molecular methods applied on soil DNA, on whole enrichment culture DNA, and on 85 isolated strains. Strains were characterized for their 16S rDNA restriction profiles and for their random amplified polymorphic DNA profiles. Catabolic capabilities were monitored by phenotypic traits and by PCR assays for the presence of the catabolic genes methyl mono-oxygenase ( xylA, M), catechol 2,3 dioxygenase (xylE) and toluene dioxygenase (todC1) of TOL and TOD pathways. Different haplotypes belonging to Pseudomonas putida, Ps. aureofaciens and Ps. aeruginosa were found to degrade aromatic compounds and naphtha solvent. The intrinsic catabolic activity of the microbial population of the polluted site was detected by PCR amplification of the xylE gene directly from soil DNA.

  11. Land-based salmon aquacultures change the quality and bacterial degradation of riverine dissolved organic matter

    Science.gov (United States)

    Kamjunke, Norbert; Nimptsch, Jorge; Harir, Mourad; Herzsprung, Peter; Schmitt-Kopplin, Philippe; Neu, Thomas R.; Graeber, Daniel; Osorio, Sebastian; Valenzuela, Jose; Carlos Reyes, Juan; Woelfl, Stefan; Hertkorn, Norbert

    2017-03-01

    Aquacultures are of great economic importance worldwide but pollute pristine headwater streams, lakes, and estuaries. However, there are no in-depth studies of the consequences of aquacultures on dissolved organic matter (DOM) composition and structure. We performed a detailed molecular level characterization of aquaculture DOM quality and its bacterial degradation using four salmon aquacultures in Chile. Fluorescence measurements, ultrahigh-resolution mass spectrometry, and nuclear magnetic resonance spectroscopy of the DOM revealed specific and extensive molecular alterations caused by aquacultures. Aquacultures released large quantities of readily bioavailable metabolites (primarily carbohydrates and peptides/proteins, and lipids), causing the organic matter downstream of all the investigated aquacultures to deviate strongly from the highly processed, polydisperse and molecularly heterogeneous DOM found in pristine rivers. However, the upstream individual catchment DOM signatures remained distinguishable at the downstream sites. The benthic algal biovolume decreased and the bacterial biovolume and production increased downstream of the aquacultures, shifting stream ecosystems to a more heterotrophic state and thus impairing the ecosystem health. The bacterial DOM degradation rates explain the attenuation of aquaculture DOM within the subsequent stream reaches. This knowledge may aid the development of improved waste processing facilities and may help to define emission thresholds to protect sensitive stream ecosystems.

  12. Comparative analysis of tertiary alcohol esterase activity in bacterial strains isolated from enrichment cultures and from screening strain libraries.

    Science.gov (United States)

    Herter, Susanne; Nguyen, Giang-Son; Thompson, Mark L; Steffen-Munsberg, Fabian; Schauer, Frieder; Bornscheuer, Uwe T; Kourist, Robert

    2011-05-01

    The preparation of enantiopure tertiary alcohols is of great contemporary interest due to the application of these versatile building blocks in organic synthesis and as precursors towards high value pharmaceutical compounds. Herein, we describe two approaches taken towards the discovery of novel biocatalysts for the synthesis of these valuable compounds. The first approach was initiated with screening of 47 bacterial strains for hydrolytic activity towards the simple tertiary alcohol ester tert-butyl acetate. In conjunction, a second method focussed on the isolation of strains competent for growth on tert-butyl acetate as the sole source of carbon and energy. From functional screening, 10 Gram-positive Actinomycetes showed hydrolytic activity, whilst enrichment selection resulted in the identification of 14 active strains, of which five belong to the Gram-negative cell-wall type. Bacterial strains obtained from both approaches were viable for enantioselective hydrolysis of pyridine substituted tertiary alcohol esters in addition to bulky aliphatic and keto-derived substrates from the same class. Activity towards each of the test substrates was uncovered, with promising enantioselectivities of up to E = 71 in the hydrolysis of a para-substituted pyridine tertiary alcohol ester using a strain of Rhodococcus ruber. Interestingly strains of Microbacterium and Alcaligenes sp. gave opposite enantiopreference in the hydrolysis of a meta-substituted pyridine tertiary alcohol ester with E values of 17 and 54. These approaches show that via both possibilities, screening established strain collections and performing enrichment selection, it is possible to identify novel species which show activity towards sterically challenging substrates.

  13. Tyrosol degradation via the homogentisic acid pathway in a newly isolated Halomonas strain from olive processing effluents

    OpenAIRE

    Liebgott, Pierre-Pol; Labat, Marc; Amouric, Agnès; Tholozan, Jean-Luc; Lorquin, Jean

    2008-01-01

    To isolate a new Halomonas sp. strain capable of degrading tyrosol, a toxic compound present in olive mill wastewater, through the homogentisic acid (HGA) pathway. A moderately halophilic Gram-negative bacterium belonging to the Halomonas genus and designated strain TYRC17 was isolated from olive processing effluents. This strain was able to completely degrade tyrosol (2-(p-hydroxyphenyl)-ethanol), a toxic compound found in such effluent. Tyrosol degradation begins by an oxidation to 4-hydrox...

  14. Marine methane paradox explained by bacterial degradation of dissolved organic matter

    Science.gov (United States)

    Repeta, Daniel J.; Ferrón, Sara; Sosa, Oscar A.; Johnson, Carl G.; Repeta, Lucas D.; Acker, Marianne; Delong, Edward F.; Karl, David M.

    2016-12-01

    Biogenic methane is widely thought to be a product of archaeal methanogenesis, an anaerobic process that is inhibited or outcompeted by the presence of oxygen and sulfate. Yet a large fraction of marine methane delivered to the atmosphere is produced in high-sulfate, fully oxygenated surface waters that have methane concentrations above atmospheric equilibrium values, an unexplained phenomenon referred to as the marine methane paradox. Here we use nuclear magnetic resonance spectroscopy to show that polysaccharide esters of three phosphonic acids are important constituents of dissolved organic matter in seawater from the North Pacific. In seawater and pure culture incubations, bacterial degradation of these dissolved organic matter phosphonates in the presence of oxygen releases methane, ethylene and propylene gas. Moreover, we found that in mutants of a methane-producing marine bacterium, Pseudomonas stutzeri, disrupted in the C-P lyase phosphonate degradation pathway, methanogenesis was also disabled, indicating that the C-P lyase pathway can catalyse methane production from marine dissolved organic matter. Finally, the carbon stable isotope ratio of methane emitted during our incubations agrees well with anomalous isotopic characteristics of seawater methane. We estimate that daily cycling of only about 0.25% of the organic matter phosphonate inventory would support the entire atmospheric methane flux at our study site. We conclude that aerobic bacterial degradation of phosphonate esters in dissolved organic matter may explain the marine methane paradox.

  15. Remote sensing of bacterial response to degrading phytoplankton in the Arabian Sea.

    Science.gov (United States)

    Priyaja, P; Dwivedi, R; Sini, S; Hatha, M; Saravanane, N; Sudhakar, M

    2016-12-01

    A remote sensing technique has been developed to detect physiological condition of phytoplankton using in situ and moderate imaging spectroradiometer (MODIS)-Aqua data. The recurring massive mixed algal bloom of diatom and Noctiluca scintillans in the Northern Arabian Sea during winter-spring was used as test bed to study formation, growth and degradation of phytoplankton. The ratio of chlorophyll (chl) to particulate organic carbon (POC) was considered as an indicator of phytoplankton physiological condition and used for the approach development. Algal blooms represent the areas of new production, and therefore, knowledge of their degradation is important to the study microbial loop and export carbon flux. Relation of chl/POC ratio with bacterial abundance revealed Gaussian distribution. Bacteria were strongly correlated with POC, and hence, the latter which is available from satellite data could be used as a proxy for remote assessment of bacteria. Thresholds for active and degrading phytoplankton were determined using the ratio computed from the satellite data. The criteria were implemented on MODIS data to generate an image representing distribution of degrading algal bloom. Bacteria abundance data from two validation cruises during dinoflagellate and cyanobacteria bloom confirmed well match up of phytoplankton degradation information from the satellite. Comparison of environmental parameters during decay phase of dinoflagellate (N. scintillans bloom (winter) and Trichodesmium bloom (summer) revealed that degradation after active Trichodesmium bloom was more severe as compared to the N. scintillans. The present study also highlights the prediction capability of phytoplankton degradation using a time series of satellite retrieved chlorophyll/POC images.

  16. Identification of bacterial strains by laboratories participating in the Deutsches Krebsforschungszentrum quality assurance programme.

    Science.gov (United States)

    Boot, R; Reubsaet, F A G

    2007-10-01

    The quality assurance programme (QAP) of the Deutsches Krebsforschungszentrum (DKFZ) is a proficiency testing system developed to service the laboratory animal discipline. QAP comprises the quarterly distribution of two bacterial strains originating from various species of animals for identification to the species level and antibiotic susceptibility testing. We compared identification results reported by QAP participants over the years 1996-2004 with those obtained by the Dutch Bacterial Diagnostics reference laboratory on 68 samples comprising 71 bacterial strains and a fungus. Significant differences were found in the frequency of reported and correct identifications when bacteria were assigned to different groups based on morphology by Gram stain and on origin (animal versus environmental, rodent and rabbit versus other animal species, pathogen versus non-pathogens). Rodent and rabbit pathogens yielded 73% correct identifications, and with all bacterial strains only 60% of the identifications were correct. We assume that most QAP participants were from laboratory animal diagnostic laboratories. If this is true, the capabilities of laboratories in the laboratory animal discipline to correctly identify bacterial species are well below what are considered acceptable limits for human diagnostic laboratories. The distribution of cultured bacteria circumvents the most difficult step in the microbiological monitoring of animals, namely primary culture from clinical samples. We propose to set up a QAP that comprises the distribution of specimens mimicking clinical samples normally submitted to laboratory animal diagnostic laboratories.

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

    NARCIS (Netherlands)

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

    1999-01-01

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

  18. Draft Genome Sequence of Sphingobium ummariense Strain RL-3, a Hexachlorocyclohexane-Degrading Bacterium.

    Science.gov (United States)

    Kohli, Puneet; Dua, Ankita; Sangwan, Naseer; Oldach, Phoebe; Khurana, J P; Lal, Rup

    2013-11-14

    Here, we report the draft genome sequence of the hexachlorocyclohexane (HCH)-degrading bacterium Sphingobium ummariense strain RL-3, which was isolated from the HCH dumpsite located in Lucknow, India (27°00'N and 81°09'E). The annotated draft genome sequence (4.75 Mb) of strain RL-3 consisted of 139 contigs, 4,645 coding sequences, and 65% G+C content.

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

    DEFF Research Database (Denmark)

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

    2008-01-01

    dish and a perforated Teflon((R)) membrane to control diffusive fluxes of substrate (benzoate) whilst permitting direct observation of bacterial colonies. The system was inoculated with prescribed strains of Pseudomonas, whose growth was quantified by microscopic monitoring of the fluorescent proteins...

  20. Isolation and characterization of novel bacterial strains exhibiting ligninolytic potential

    Directory of Open Access Journals (Sweden)

    Bandounas Luaine

    2011-10-01

    Full Text Available Abstract Background To expand on the range of products which can be obtained from lignocellulosic biomass, the lignin component should be utilized as feedstock for value-added chemicals such as substituted aromatics, instead of being incinerated for heat and energy. Enzymes could provide an effective means for lignin depolymerization into products of interest. In this study, soil bacteria were isolated by enrichment on Kraft lignin and evaluated for their ligninolytic potential as a source of novel enzymes for waste lignin valorization. Results Based on 16S rRNA gene sequencing and phenotypic characterization, the organisms were identified as Pandoraea norimbergensis LD001, Pseudomonas sp LD002 and Bacillus sp LD003. The ligninolytic capability of each of these isolates was assessed by growth on high-molecular weight and low-molecular weight lignin fractions, utilization of lignin-associated aromatic monomers and degradation of ligninolytic indicator dyes. Pandoraea norimbergensis LD001 and Pseudomonas sp. LD002 exhibited best growth on lignin fractions, but limited dye-decolourizing capacity. Bacillus sp. LD003, however, showed least efficient growth on lignin fractions but extensive dye-decolourizing capacity, with a particular preference for the recalcitrant phenothiazine dye class (Azure B, Methylene Blue and Toluidene Blue O. Conclusions Bacillus sp. LD003 was selected as a promising source of novel types of ligninolytic enzymes. Our observations suggested that lignin mineralization and depolymerization are separate events which place additional challenges on the screening of ligninolytic microorganisms for specific ligninolytic enzymes.

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

    Directory of Open Access Journals (Sweden)

    Boutheina Gargouri

    2015-01-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Gendrault-Jacquemard A

    2005-07-01

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

  5. Bacterial cellulose produced by a new acid-resistant strain of Gluconacetobacter genus.

    Science.gov (United States)

    Castro, Cristina; Zuluaga, Robin; Álvarez, Catalina; Putaux, Jean-Luc; Caro, Gloria; Rojas, Orlando J; Mondragon, Iñaki; Gañán, Piedad

    2012-08-01

    A bacterial strain isolated from the fermentation of Colombian homemade vinegar, Gluconacetobacter medellensis, was investigated as a new source of bacterial cellulose (BC). The BC produced from substrate media consisting of various carbon sources at different pH and incubation times was quantified. Hestrin-Schramm (HS) medium modified with glucose led to the highest BC yields followed by sucrose and fructose. Interestingly, the microorganisms are highly tolerant to low pH: an optimum yield of 4.5 g/L was achieved at pH 3.5, which is generally too low for other bacterial species to function. The cellulose microfibrils produced by the new strain were characterized by scanning and transmission electron microscopy, infrared spectroscopy X-ray diffraction and elemental analysis. The morphological, structural and chemical characteristics of the cellulose produced are similar to those expected for BC.

  6. In vitro screening of pentamidine analogs against bacterial and fungal strains.

    Science.gov (United States)

    Maciejewska, Dorota; Żabiński, Jerzy; Kaźmierczak, Paweł; Wójciuk, Karolina; Kruszewski, Marcin; Kruszewska, Hanna

    2014-07-01

    A series of linear pentamidine analogs exhibiting low cytotoxicity, active against Pneumocystis carinii, were evaluated for in vitro activities against bacterial and fungal strains. The majority of the tested bis-amidines exhibited marked activities against Gram-positive strains. In view of the fact that the highest potency was found for 1,5-bis(4-amidinophenoxy)-3-thiapentane dihydrochloride 1j with the S atom in the middle of the aliphatic linker, four new pentamidines bearing S atoms were synthesized and also evaluated against MRSA strains. N,N'-Dialkylated pentamidines with S atoms in the linker are the promising lead structures for antimicrobials development.

  7. Genomic analysis of six new Geobacillus strains reveals highly conserved carbohydrate degradation architectures and strategies

    Directory of Open Access Journals (Sweden)

    Phillip eBrumm

    2015-05-01

    Full Text Available In this work we report the whole genome sequences of six new Geobacillus xylanolytic strains along with the genomic analysis of their capability to degrade carbohydrates.. The six sequenced Geobacillus strains described here have a range of GC contents from 43.9% to 52.5% and clade with named Geobacillus species throughout the entire genus. We have identified a ~200 kb unique super-cluster in all six strains, containing five to eight distinct carbohydrate degradation clusters in a single genomic region, a feature not seen in other genera. The Geobacillus strains rely on a small number of secreted enzymes located within distinct clusters for carbohydrate utilization, in contrast to most biomass-degrading organisms which contain numerous secreted enzymes located randomly throughout the genomes. All six strains are able to utilize fructose, arabinose, xylose, mannitol, gluconate, xylan, and α-1,6-glucosides. The gene clusters for utilization of these seven substrates have identical organization and the individual proteins have a high percent identity to their homologs. The strains show significant differences in their ability to utilize inositol, sucrose, lactose, α-mannosides, α-1,4-glucosides and arabinan.

  8. Relationship between bacterial diversity and function under biotic control: the soil pesticide degraders as a case study

    OpenAIRE

    2010-01-01

    In soil, the way biotic parameters impact the relationship between bacterial diversity and function is still unknown. To understand these interactions better, we used RNA-based stable-isotope probing to study the diversity of active atrazine-degrading bacteria in relation to atrazine degradation and to explore the impact of earthworm-soil engineering with respect to this relationship. Bulk soil, burrow linings and earthworm casts were incubated with 13C-atrazine. The pollutant degradation was...

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

    Science.gov (United States)

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

    2016-03-01

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

  10. Aerobic degradation of ibuprofen in batch and continuous reactors by an indigenous bacterial community.

    Science.gov (United States)

    Fortunato, María Susana; Fuentes Abril, Nancy Piedad; Martinefski, Manuela; Trípodi, Valeria; Papalia, Mariana; Rádice, Marcela; Gutkind, Gabriel; Gallego, Alfredo; Korol, Sonia Edith

    2016-10-01

    Water from six points from the Riachuelo-Matanza basin was analyzed in order to assess ibuprofen biodegradability. In four of them biodegradation of ibuprofen was proved and degrading bacterial communities were isolated. Biodegradation in each point could not be correlated with sewage pollution. The indigenous bacterial community isolated from the point localized in the La Noria Bridge showed the highest degradative capacity and was selected to perform batch and continuous degradation assays. The partial 16S rRNA gene sequence showed that the community consisted of Comamonas aquatica and Bacillus sp. In batch assays the community was capable of degrading 100 mg L(-1) of ibuprofen in 33 h, with a specific growth rate (μ) of 0.21 h(-1). The removal of the compound, as determined by High performance liquid chromatography (HPLC), exceeded 99% of the initial concentration, with a 92.3% removal of Chemical Oxygen Demand (COD). In a down-flow fixed-bed continuous reactor, the community shows a removal efficiency of 95.9% of ibuprofen and 92.3% of COD for an average inlet concentration of 110.4 mg. The reactor was kept in operation for 70 days. The maximal removal rate for the compound was 17.4 g m(-3) d(-1). Scanning electron microscopy was employed to observe biofilm development in the reactor. The ability of the isolated indigenous community can be exploited to improve the treatment of wastewaters containing ibuprofen.

  11. Isolation and characteristics analysis of a novel high bacterial cellulose producing strain Gluconacetobacter intermedius CIs26.

    Science.gov (United States)

    Yang, Ying; Jia, Jingjing; Xing, Jianrong; Chen, Jianbing; Lu, Shengmin

    2013-02-15

    A strain producing bacterial cellulose (BC) screened from rotten mandarin fruit was identified as Gluconacetobacter intermedius CIs26 by the examination of general taxonomical characteristics and 16S rDNA sequence analysis. Furthermore, Fourier transform infrared (FT-IR) spectrum showed that pellicle produced by strain CIs26 was composed of glucan, and had the same functional group as a typical BC. X-ray diffractometry (XRD) analysis indicated that the BC was type I in structure with crystallinity index of 75%. BC yields of strain CIs26 in Hestrin-Schramn (HS), citrus waste modified HS (CMHS) and citrus waste solution (CWS) mediums were 2.1 g/L, 5.7 g/L, and 7.2 g/L, respectively. It was shown that citrus waste could stimulate BC production of strain CIs26 efficiently. Based on the ability of utilization of citrus waste, this strain appeared to have potential in BC manufacture on an industrial scale.

  12. The potential of glycerol in freezing preservation of turbine oil-degrading bacterial consortium and the ability of the revised consortium to degrade petroleum wastes

    OpenAIRE

    Kurachi, Kumiko; Hosokawa, Reia; Takahashi, Marina; Okuyama, Hidetoshi

    2014-01-01

    The turbine oil (TuO)-degrading bacterial consortium Tank-2 (original Tank-2) was preserved as a glycerol stock at -80 degrees C from 2009 to 2012. Storage methods have been unavailable so far for any TuO-degrading bacterial consortia or isolates. To evaluate the usefulness of glycerol stock, the original Tank-2 consortium frozen in glycerol at -80 degrees C was thawed and then revived by repeated culture in mineral salts medium (MSM) containing 0.5% (w/w) TuO (revived Tank-2). The revived Ta...

  13. Strain-Dependent Effect of Macroautophagy on Abnormally Folded Prion Protein Degradation in Infected Neuronal Cells.

    Directory of Open Access Journals (Sweden)

    Daisuke Ishibashi

    Full Text Available Prion diseases are neurodegenerative disorders caused by the accumulation of abnormal prion protein (PrPSc in the central nervous system. With the aim of elucidating the mechanism underlying the accumulation and degradation of PrPSc, we investigated the role of autophagy in its degradation, using cultured cells stably infected with distinct prion strains. The effects of pharmacological compounds that inhibit or stimulate the cellular signal transduction pathways that mediate autophagy during PrPSc degradation were evaluated. The accumulation of PrPSc in cells persistently infected with the prion strain Fukuoka-1 (FK, derived from a patient with Gerstmann-Sträussler-Scheinker syndrome, was significantly increased in cultures treated with the macroautophagy inhibitor 3-methyladenine (3MA but substantially reduced in those treated with the macroautophagy inducer rapamycin. The decrease in FK-derived PrPSc levels was mediated, at least in part, by the phosphatidylinositol 3-kinase/MEK signalling pathway. By contrast, neither rapamycin nor 3MA had any apparently effect on PrPSc from either the 22L or the Chandler strain, indicating that the degradation of PrPSc in host cells might be strain-dependent.

  14. Isolation of a Pseudomonas aeruginosa strain from soil that can degrade polyurethane diol.

    Science.gov (United States)

    Mukherjee, Koushik; Tribedi, Prosun; Chowdhury, Arup; Ray, Tanusree; Joardar, Archi; Giri, Subhajit; Sil, Alok Kumar

    2011-04-01

    Polyurethane diol (PUR-diol), a synthetic polymer, is widely used as a modifier for water-soluble resins and emulsions in wood appliances and auto coatings. Non-biodegradability of polyurethanes (PUR) and PUR-based materials poses a threat to environment that has led scientists to isolate microbes capable of degrading PUR. However, the bio-degradation of PUR-diol has not yet been reported. In this study, we report isolation of a soil bacterium that can survive using PUR-diol as sole carbon source. PUR-diol degradation by the organism was confirmed by thin layer chromatographic analysis of the conditioned medium obtained after the growth wherein a significant reduction of PUR-diol was observed compared to non-inoculated medium. To quantify the PUR-diol degradation, a sensitive assay based on High Performance Thin Layer Chromatography has been developed that showed 32% degradation of PUR-diol by the organism in 10 days. Degradation kinetics showed the maximal depletion of PUR-diol during logarithmic growth of the organism indicating a direct relation between the growth and PUR-diol degradation. Mutagenic study and GC-MS analysis revealed that esterase activity is involved in this degradation event. The ribotyping and metabolic fingerprinting analysis showed that this organism is a strain of Pseudomonous aeruginosa (P. aeruginosa). It has also been observed that this strain is able to degrade Impranil DLN™, a variety of commercially available PUR. Therefore this study identifies a new bacterium from soil that has the potential to reduce PUR-related waste burden and adds a new facet to diverse functional activities of P. aeruginosa.

  15. Screening a strain of Aspergillus niger and optimization of fermentation conditions for degradation of aflatoxin B₁.

    Science.gov (United States)

    Zhang, Wei; Xue, Beibei; Li, Mengmeng; Mu, Yang; Chen, Zhihui; Li, Jianping; Shan, Anshan

    2014-11-13

    Aflatoxin B₁, a type of highly toxic mycotoxin produced by some species belonging to the Aspergillus genus, such as Aspergillus flavus and Aspergillus parasiticus, is widely distributed in feed matrices. Here, coumarin was used as the sole carbon source to screen microorganism strains that were isolated from types of feed ingredients. Only one isolate (ND-1) was able to degrade aflatoxin B₁ after screening. ND-1 isolate, identified as a strain of Aspergillus niger using phylogenetic analysis on the basis of 18S rDNA, could remove 26.3% of aflatoxin B₁ after 48 h of fermentation in nutrient broth (NB). Optimization of fermentation conditions for aflatoxin B₁ degradation by selected Aspergillus niger was also performed. These results showed that 58.2% of aflatoxin B₁ was degraded after 24 h of culture under the optimal fermentation conditions. The aflatoxin B₁ degradation activity of Aspergillus niger supernatant was significantly stronger than cells and cell extracts. Furthermore, effects of temperature, heat treatment, pH, and metal ions on aflatoxin B₁ degradation by the supernatant were examined. Results indicated that aflatoxin B₁ degradation of Aspergillus niger is enzymatic and this process occurs in the extracellular environment.

  16. Molecular characterization of Lactobacillus plantarum DMDL 9010, a strain with efficient nitrite degradation capacity.

    Science.gov (United States)

    Fei, Yong-tao; Liu, Dong-mei; Luo, Tong-hui; Chen, Gu; Wu, Hui; Li, Li; Yu, Yi-gang

    2014-01-01

    Nitrites commonly found in food, especially in fermented vegetables, are potential carcinogens. Therefore, limiting nitrites in food is critically important for food safety. A Lactobacillus strain (Lactobacillus sp. DMDL 9010) was previously isolated from fermented vegetables by our group, and is not yet fully characterized. A number of phenotypical and genotypical approaches were employed to characterize Lactobacillus sp. DMDL 9010. Its nitrite degradation capacity was compared with four other Lactobacillus strains, including Lactobacillus casei subsp. rhamnosus 719, Lactobacillus delbrueckii subsp. bulgaricu 1.83, Streptococcus thermophilus 1.204, and lactobacillus plantarum 8140, on MRS medium. Compared to these four Lactobacillus strains, Lactobacillus sp. DMDL 9010 had a significantly higher nitrite degradation capacity (PLactobacillus sp. DMDL 9010 was identified as either Lactobacillus plantarum or Lactobacillus pentosus. To further identify this strain, the flanking regions (922 bp and 806 bp upstream and downstream, respectively) of the L-lactate dehydrogenase 1 (L-ldh1) gene were amplified and sequenced. Lactobacillus sp. DMDL 9010 had 98.92 and 76.98% sequence identity in the upstream region with L. plantarum WCFS1 and L. pentosus IG1, respectively, suggesting that Lactobacillu sp. DMDL 9010 is an L. plantarum strain. It was therefore named L. plantarum DMDL 9010. Our study provides a platform for genetic engineering of L. plantarum DMDL 9010, in order to further improve its nitrite degradation capacity.

  17. Effect of microstructure on anomalous strain-rate-dependent behaviour of bacterial cellulose hydrogel.

    Science.gov (United States)

    Gao, Xing; Shi, Zhijun; Lau, Andrew; Liu, Changqin; Yang, Guang; Silberschmidt, Vadim V

    2016-05-01

    This study is focused on anomalous strain-rate-dependent behaviour of bacterial cellulose (BC) hydrogel that can be strain-rate insensitive, hardening, softening, or strain-rate insensitive in various ranges of strain rate. BC hydrogel consists of randomly distributed nanofibres and a large content of free water; thanks to its ideal biocompatibility, it is suitable for biomedical applications. Motivated by its potential applications in complex loading conditions of body environment, its time-dependent behaviour was studied by means of in-aqua uniaxial tension tests at constant temperature of 37 °C at various strain rates ranging from 0.000 1s(-1) to 0.3s(-1). Experimental results reflect anomalous strain-rate-dependent behaviour that was not documented before. Micro-morphological observations allowed identification of deformation mechanisms at low and high strain rates in relation to microstructural changes. Unlike strain-rate softening behaviours in other materials, reorientation of nanofibres and kinematics of free-water flow dominate the softening behaviour of BC hydrogel at high strain rates.

  18. Genes involved in alkane degradation in the Alcanivorax hongdengensis strain A-11-3.

    Science.gov (United States)

    Wang, Wanpeng; Shao, Zongze

    2012-04-01

    Alcanivorax hongdengensis A-11-3 is a newly identified type strain isolated from the surface water of the Malacca and Singapore Straits that can degrade a wide range of alkanes. To understand the degradation mechanism of this strain, the genes encoding alkane hydroxylases were obtained by PCR screening and shotgun sequencing of a genomic fosmid library. Six genes involved in alkane degradation were found, including alkB1, alkB2, p450-1, p450-2, p450-3 and almA. Heterogeneous expression analysis confirmed their functions as alkane oxidases in Pseudomonas putida GPo12 (pGEc47ΔB) or Pseudomonas fluorescens KOB2Δ1. Q-PCR revealed that the transcription of alkB1 and alkB2 was enhanced in the presence of n-alkanes C(12) to C(24); three p450 genes were up-regulated by C(8)-C(16) n-alkanes at different levels, whereas enhanced expression of almA was observed when strain A-11-3 grew with long-chain alkanes (C(24) to C(36)). In the case of branched alkanes, pristane significantly enhanced the expression of alkB1, p450-3 and almA. The six genes enable strain A-11-3 to degrade short (C(8)) to long (C(36)) alkanes that are straight or branched. The ability of A. hongdengensis A-11-3 to thrive in oil-polluted marine environments may be due to this strain's multiple systems for alkane degradation and its range of substrates.

  19. The use of Molecular Beacons to Directly Measure Bacterial mRNA Abundances and Transcript Degradation

    Science.gov (United States)

    Kuechenmeister, Lisa J.; Anderson, Kelsi L.; Morrison, John M.; Dunman, Paul M.

    2009-01-01

    The regulation of mRNA turnover is a dynamic means by which bacteria regulate gene expression. Although current methodologies allow characterization of the stability of individual transcripts, procedures designed to measure alterations in transcript abundance/turnover on a high throughput scale are lacking. In the current report, we describe the development of a rapid and simplified molecular beacon-based procedure to directly measure the mRNA abundances and mRNA degradation properties of well-characterized Staphylococcus aureus pathogenicity factors. This method does not require any PCR-based amplification, can monitor the abundances of multiple transcripts within a single RNA sample, and was successfully implemented into a high throughput screen of transposon mutant library members to detect isolates with altered mRNA turnover properties. It is expected that the described methodology will provide great utility in characterizing components of bacterial RNA degradation processes and can be used to directly measure the mRNA levels of virtually any bacterial transcript. PMID:18992285

  20. Serological studies on chloridazon-degrading bacteria.

    Science.gov (United States)

    Layh, G; Böhm, R; Eberspächer, J; Lingens, F

    1983-01-01

    Agglutination tests and immunofluorescence tests with antisera against four strains of chloridazon-degrading bacteria revealed the serological uniformity of a group of 22 chloridazon-degrading bacterial strains. No serological relationship could be found between chloridazon-degrading bacteria and representatives of other Gram-negative bacteria. This was demonstrated by agglutination tests, including testing of the antiserum against Acinetobacter calcoaceticus, and by immunofluorescence tests, including testing of the sera against Pseudomonas and Acinetobacter strains. The tests were performed with 31 representatives of different Gram-negative bacteria, and with 22 strains of chloridazon-degrading bacteria as antigens. Differences in the extent of agglutination reactions and antibody titres among chloridazon-degrading bacterial strains together with cross-adsorption xperiments, suggest a rough classification of chloridazon-degrading bacteria into two subgroups. On the basis of immunofluorescence data, a linkage-map was worked out to represent serological relationships in the group of chloridazon-degrading strains.

  1. A 2,4-dichlorophenoxyacetic acid degradation plasmid pM7012 discloses distribution of an unclassified megaplasmid group across bacterial species.

    Science.gov (United States)

    Sakai, Yoriko; Ogawa, Naoto; Shimomura, Yumi; Fujii, Takeshi

    2014-03-01

    Analysis of the complete nucleotide sequence of plasmid pM7012 from 2,4-dichlorophenoxyacetic-acid (2,4-D)-degrading bacterium Burkholderia sp. M701 revealed that the plasmid had 582 142 bp, with 541 putative protein-coding sequences and 39 putative tRNA genes for the transport of the standard 20 aa. pM7012 contains sequences homologous to the regions involved in conjugal transfer and plasmid maintenance found in plasmids byi_2p from Burkholderia sp. YI23 and pBVIE01 from Burkholderia sp. G4. No relaxase gene was found in any of these plasmids, although genes for a type IV secretion system and type IV coupling proteins were identified. Plasmids with no relaxase gene have been classified as non-mobile plasmids. However, nucleotide sequences with a high level of similarity to the genes for plasmid transfer, plasmid maintenance, 2,4-D degradation and arsenic resistance contained on pM7012 were also detected in eight other megaplasmids (~600 or 900 kb) found in seven Burkholderia strains and a strain of Cupriavidus, which were isolated as 2,4-D-degrading bacteria in Japan and the United States. These results suggested that the 2,4-D degradation megaplasmids related to pM7012 are mobile and distributed across various bacterial species worldwide, and that the plasmid group could be distinguished from known mobile plasmid groups.

  2. Preparation of petroleum-degrading bacterial agent and its application in remediation of contaminated soil in Shengli Oil Field, China.

    Science.gov (United States)

    Yu, Yang; Zhang, Wen; Chen, Guanhong; Gao, Yongchao; Wang, Jianing

    2014-01-01

    Two petroleum-degrading strains were screened from oil fields and denoted as SWH-1 (Bacillus subtilis) and SWH-2 (Sphingobacterium multivorum), which were used to ferment and prepare bacterial agent to remediate petroleum-contaminated sites in Shengli Oil Field in China. The optimal liquid fermentation medium and conditions were MgSO₄·7H₂O (0.5%), NaCl (0.5%), soybean dregs (3%), pH 7.0, culturing at 30 °C, and 220 r/min for 16 h. Peat was chosen as the bacterial carrier due to its ability of keeping microbial activity. Mixed fermented liquid was added into peat (1:2) and air-dried, and the bacterial agent was obtained. It was applied to the petroleum-contaminated soil, which was irrigated, tilled, and fertilized. The removal rate reached 67.7% after 2 months of remediation. During remediation, the quantity of indigenous bacteria varied a lot, while the inoculated bacteria remained stable; the dehydrogenase activity was at high levels and then decreased. Indigenous microorganisms, inoculated bacterial agent, nutrients, water, and soil permeability all played important roles. The study prepared an environment-friendly bacterial agent and established a set of bioremediation technique, which provided further insights into integration of fermentation engineering and soil remediation engineering.

  3. Enzymatic degradation of granular potato starch by Microbacterium aurum strain B8.A.

    Science.gov (United States)

    Sarian, Fean D; van der Kaaij, Rachel M; Kralj, Slavko; Wijbenga, Dirk-Jan; Binnema, Doede J; van der Maarel, Marc J E C; Dijkhuizen, Lubbert

    2012-01-01

    Microbacterium aurum strain B8.A was isolated from the sludge of a potato starch-processing factory on the basis of its ability to use granular starch as carbon- and energy source. Extracellular enzymes hydrolyzing granular starch were detected in the growth medium of M. aurum B8.A, while the type strain M. aurum DSMZ 8600 produced very little amylase activity, and hence was unable to degrade granular starch. The strain B8.A extracellular enzyme fraction degraded wheat, tapioca and potato starch at 37 °C, well below the gelatinization temperature of these starches. Starch granules of potato were hydrolyzed more slowly than of wheat and tapioca, probably due to structural differences and/or surface area effects. Partial hydrolysis of starch granules by extracellular enzymes of strain B8.A resulted in large holes of irregular sizes in case of wheat and tapioca and many smaller pores of relatively homogeneous size in case of potato. The strain B8.A extracellular amylolytic system produced mainly maltotriose and maltose from both granular and soluble starch substrates; also, larger maltooligosaccharides were formed after growth of strain B8.A in rich medium. Zymogram analysis confirmed that a different set of amylolytic enzymes was present depending on the growth conditions of M. aurum B8.A. Some of these enzymes could be partly purified by binding to starch granules.

  4. Kinetics of degradation of carbendazim by B. subtilis strains: possibility of in situ detoxification.

    Science.gov (United States)

    Salunkhe, Varsha P; Sawant, Indu S; Banerjee, Kaushik; Wadkar, Pallavi N; Sawant, Sanjay D; Hingmire, Sandip A

    2014-12-01

    Food safety is a global concern due to the increased use of pesticides in agriculture. In grapes, carbendazim is one of the frequently detected fungicides. However, it is amenable to biodegradation. In this study, we aimed to assess the degradation of carbendazim by four Bacillus subtilis strains, which had earlier shown potential for biocontrol of grape diseases. In liquid medium, each of the four strains, namely, DR-39, CS-126, TL-171, and TS-204, could utilize carbendazim as the sole carbon source. The half-life was minimized from 8.4 days in the uninoculated spiked control to 4.0-6.2 days by the four strains. In Thompson Seedless sprayed with carbendazim at 1.0 g L(-1), the residue on grape berries in control was 0.44 mg kg(-1) after 25 days of application, whereas in grapes treated with the four B. subtilis strains, the residues had decreased to 0.02 mg kg(-1). The degradation kinetics showed low half-lives of 3.1 to 5.2 days in treated grapes as compared to 8.8 days in control. In inoculated soils, the half-lives were 5.9 to 7.6 days in autoclaved and 6.5 to 7.2 days in nonautoclaved soils as compared to 8.2 and 8.0 days in respective controls. The growth dynamics of these strains in all the three matrices was not affected by presence of carbendazim. Bacillus strains TS-204 and TL-171 showed higher degradation rate than the other two strains in all the three matrices and show promise for in situ biodegradation of carbendazim.

  5. Screening of bacterial strains producing maltotetraose-forming amylase and the conditions for enzyme production.

    Science.gov (United States)

    Yan, Z; She, X; Li, M; Zhang, S

    1992-01-01

    The authors isolated 1380 bacterial strains from 290 soil samples collected in China and 490 strains were received from other research teams in this institute. By screening 707 strains showed starch-hydrolyzing activity. By further screening and paper chromatographic test, three strains with maltotetraose as the major product were obtained. The maltotetraose was further confirmed by treatment with beta-amylase splitting to maltose and with glucoamylase to glucose. The most promising strain was 537.1, which produced maltotetraose about 90% (w/w) in the starch hydrolysate. While the other two strains produced maltose and maltotriose besides maltotetraose. Strain 537.1 was tentatively identified as Alcaligenes sp. The optimum conditions for enzyme production were as follows: medium composition: 1.5% maltose; 0.5% peptone with initial pH of 7.0-7.5; cultured at 27-28 degrees C for 48 hours on rotary shaker. The culture supernatant of the strain 537.1 can hydrolyze starch and different kinds of cereal flour with a high yield of maltotetraose in the hydrolysate.

  6. The antimicrobial activity of thyme essential oil against multidrug resistant clinical bacterial strains.

    Science.gov (United States)

    Sienkiewicz, Monika; Łysakowska, Monika; Denys, Paweł; Kowalczyk, Edward

    2012-04-01

    The aim of this work was to investigate the antimicrobial activity of thyme essential oil against clinical multidrug resistant strains of Staphylococcus, Enterococcus, Escherichia, and Pseudomonas genus. The antibacterial activity of oil was tested against standard strains of bacteria and 120 clinical strains isolated from patients with infections of the oral cavity, abdominal cavity, respiratory and genitourinary tracts, skin, and from the hospital environment. Agar diffusion was used to determine the microbial growth inhibition of bacterial growth at various concentrations of oil from Thymus vulgaris. Susceptibility testing to antibiotics was carried out using disk diffusion. Thyme essential oil strongly inhibited the growth of the clinical strains of bacteria tested. The use of phytopharmaceuticals based on an investigated essential oil from thyme in the prevention and treatment of various human infections may be reasonable.

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

    Directory of Open Access Journals (Sweden)

    Mileidy Cruz-Martín

    2016-01-01

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

  8. The Role of the Bacterial Community of an Agroecosystem in Simazine Degradation

    Directory of Open Access Journals (Sweden)

    Anna Barra Caracciolo

    Full Text Available The use of pesticides and fertilizers in agricultural practice is the main source of soil and groundwater contamination. S-Triazines are among the most used herbicides in the world for selective weed control in several types of crops. The homeostatic capability of an agroecosystem to remove a triazinic herbicide, simazine, was assessed in microcosms treated with the herbicide in presence/absence of urea fertilizer. The latter, as well as a fertilizer, is also one of the last by-products before simazine mineralization. The biodegradation, in terms of disappearance of 50% of the initial concentration (DT50, was compared to the degradation and metabolite formation occurring in sterilized soil. Moreover, the bacterial community response was assessed in terms of abundance and community structure by the epifluorescence direct count method and fluorescence in situ hybridization. The results show that the microbial community has a primary role in simazine degradation and that this process is due to the presence of a microbial pool working in succession and of which the metabolism may be modulated by exogenous sources of nitrogen, like urea. The latter influences the degradative pathway with a greater formation and accumulation of the desethyl-simazine metabolite, which is a hazardous contaminant of soil and groundwater ecosystems, as well as its parent compound.

  9. The Role of the Bacterial Community of an Agroecosystem in Simazine Degradation

    Directory of Open Access Journals (Sweden)

    Roberto Ciccoli

    2011-02-01

    Full Text Available The use of pesticides and fertilizers in agricultural practice is the main source of soil and groundwater contamination. S-Triazines are among the most used herbicides in the world for selective weed control in several types of crops. The homeostatic capability of an agroecosystem to remove a triazinic herbicide, simazine, was assessed in microcosms treated with the herbicide in presence/absence of urea fertilizer. The latter, as well as a fertilizer, is also one of the last by-products before simazine mineralization. The biodegradation, in terms of disappearance of 50% of the initial concentration (DT50, was compared to the degradation and metabolite formation occurring in sterilized soil. Moreover, the bacterial community response was assessed in terms of abundance and community structure by the epifluorescence direct count method and fluorescence in situ hybridization. The results show that the microbial community has a primary role in simazine degradation and that this process is due to the presence of a microbial pool working in succession and of which the metabolism may be modulated by exogenous sources of nitrogen, like urea. The latter influences the degradative pathway with a greater formation and accumulation of the desethyl-simazine metabolite, which is a hazardous contaminant of soil and groundwater ecosystems, as well as its parent compound.

  10. Bacterial degradation of styrene in waste gases using a peat filter

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, M.; Reittu, A. [Kuopio Univ. (Finland). Dept. of Environmental Sciences; Wright, A. von; Suihko, M.L. [VTT Biotechnology and Food Research (Finland); Martikainen, P.J. [Kuopio Univ. (Finland). Dept. of Environmental Sciences]|[National Public Health Inst., Lab. of Environmental Microbiology, Kuopio (Finland)

    1997-12-31

    A biofiltration process was developed for styrene-containing off-gases using peat as filter material. The average styrene reduction ratio after 190 days of operation was 70% (max. 98%) and the mean styrene elimination capacity was 12 g m{sup -3} h{sup -1} (max. 30 g m{sup -3} h{sup -1}). Efficient styrene degradation required addition of nutrients to the peat, adjustment of the pH to a neutral level and efficient control of the humidity. Maintenance of the water balance was easier in a down-flow than in an up-flow process, the former consequently resulting in much better filtration efficiency. The optimum operation temperature was around 23 C, but the styrene removal was still satisfactory at 12 C. Seven different bacterial isolates belonging to the genera Tsukamurella, Pseudomonas, Sphingomonas, Xanthomonas and an unidentified genus in the {gamma} group of the Proteobacteria isolated from the microflora of active peat filter material were capable of styrene degradation. The isolates differed in their capacity to decompose styrene to carbon dioxide and assimilate it to biomass. No toxic intermediate degradation products of styrene were detected in the filter outlet gas or in growing cultures of isolated bacteria. The use of these isolates in industrial biofilters is beneficial at low styrene concentrations and is safe from both the environmental and public health points of view. (orig.)

  11. Differential degradation of crude oil (Bonny Light) by four Pseudomonas strains

    Institute of Scientific and Technical Information of China (English)

    Oluwafemi S. Obayori; Sunday A. Adebusoye; Adams O. Adewale; Ganiyu O. Oyetibo; Odunola O. Oluyemi; Rashid A. Amokun; Matthew O. Ilori

    2009-01-01

    Four hydrocarbon degraders isolated from enriched oil- and asphalt-contaminated soils in Lagos, Nigeria, were tested for their petroleum degradation potentials.All the isolates were identified as species of Pseudomonas.Pseudomonas putida P11 demonstrated a strong ability to degrade kerosene, gasoline, diesel, engine oil and crude oil while P.aeruginosa BB3 exhibited fair degradative ability on crude oil, gasoline, engine oil, anthracene and pyrene but weak on kerosene, diesel and dibenzothiophene.Pseudomonas putida WL2 and P.aeruginosa MVL1 grew on crude oil and all its cuts tested with the latter possessing similar polycyclic aromatic potentials as P11.All the strains grew logarithmically with 1-2 orders of magnitude and with generation time ranging significantly between 3.07 and 8.55 d at 0.05 level of confidence.Strains WL2 and MVL1 utilized the oil substrate best with more than 70% in 6 d experimental period, whereas the same feat was achieved by P11 in 12 d period.BB3 on the other hand degraded only 46% within 6 d.Interestingly, data obtained from gas chromatographic analysis of oil recovered from the culture fluids of MVL1 confirmed near-disappearance of major peaks (including aliphatics and aromatics) in the hydrocarbon mixture.

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

    Science.gov (United States)

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

    2010-09-01

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

  13. Isolation and characterization of a furfural-degrading bacterium Bacillus cereus sp. strain DS1.

    Science.gov (United States)

    Zheng, Dan; Bao, Jianguo; Lu, Jueming; Gao, Chunlei

    2015-02-01

    Furfural was found to be the main organic pollutant in the wastewater coming from the Diosgenin factory. This substance is derived from acidic pentosan in Dioscorea zingiberensis and is also found in a variety of agricultural byproducts, including corncobs, oat, wheat bran, and sawdust. It is regarded as a toxicant and an inhibitor to the growth of microorganism in both sewage disposal and biological fermentation. A furfural-degrading strain (DS1) was isolated from activated sludge of wastewater treatment plant in a diosgenin factory by continuous enrichment culture. The strain was identified as Bacillus cereus based on morphological, physiological tests, as well as on 16S rDNA sequence and Biolog analyses. The capacity of this strain to grow on a mineral salt medium, utilizing furfural as the sole carbon and energy source to degrade furfural, was investigated in this study. Under the condition of pH 9.0, temperature 35 °C, with rotating speed of 150 rpm, and an inoculum of 6 %, the strain showed that the furfural degradation capacity reaches 35 % in 7 days, as measured by high-performance liquid chromatography. The addition of inorganic carbon sources could bring down the biodegradation efficiency of the furfural. The strain DS1 showed better furfural removal capacity, as compared to other inorganic carbon sources in the media. Furthermore, a furfural concentration of as high as 4,000 mg L(-1) was tolerated by the culture. The capacity to degrade furfural was demonstrated for the first time by using the genus B. cereus. This study suggests the possible application in biodegradation strategies.

  14. Relationship between bacterial diversity and function under biotic control: the soil pesticide degraders as a case study.

    Science.gov (United States)

    Monard, Cécile; Vandenkoornhuyse, Philippe; Le Bot, Barbara; Binet, Françoise

    2011-06-01

    In soil, the way biotic parameters impact the relationship between bacterial diversity and function is still unknown. To understand these interactions better, we used RNA-based stable-isotope probing to study the diversity of active atrazine-degrading bacteria in relation to atrazine degradation and to explore the impact of earthworm-soil engineering with respect to this relationship. Bulk soil, burrow linings and earthworm casts were incubated with (13)C-atrazine. The pollutant degradation was quantified by liquid chromatography-mass spectrometry for 8 days, whereas active atrazine degraders were identified at 2 and 8 days by sequencing the 16S ribosomal RNA in the (13)C-RNA fractions from the three soil microsites. An original diversity of atrazine degraders was found. Earthworm soil engineering greatly modified the taxonomic composition of atrazine degraders with dominance of α-, β- and γ-proteobacteria in burrow linings and of Actinobacteria in casts. Earthworm soil bioturbation increased the γ-diversity of atrazine degraders over the soil microsites generated. Atrazine degradation was enhanced in burrow linings in which primary atrazine degraders, closely related to Pelomonas aquatica, were detected only 2 days after atrazine addition. Atrazine degradation efficiency was not linearly related to the species richness of degraders but likely relied on keystone species. By enhancing soil heterogeneity, earthworms sustained high phylogenetic bacterial diversity and exerted a biotic control on the bacterial diversity-function relationships. Our findings call for future investigations to assess the ecological significance of biotic controls on the relationships between diversity and function on ecosystem properties and services (for example, soil detoxification) at larger scales.

  15. Degradation of toxaphene by Bjerkandera sp. strain BOL13 using waste biomass as a cosubstrate.

    Science.gov (United States)

    Lacayo Romero, Martha; Terrazas, Enrique; van Bavel, Bert; Mattiasson, Bo

    2006-07-01

    The white-rot fungus Bjerkandera sp. strain BOL13 was capable of degrading toxaphene when supplied with wood chips, wheat husk or cane molasses as cosubstrates in batch culture experiments. Approximately 85% of toxaphene was removed when wheat husk was the main substrate. The production of lignin peroxidase was only stimulated when wheat husk was present in the liquid medium. Although xylanase was always detected, wheat husk supported the highest xylanase production. A negligible amount of beta-glucosidase and cellulase were found in the batch culture medium. To the best of our knowledge, this is the first reported case of toxaphene degradation by white-rot fungi.

  16. 一株源于醇化烟叶表面高效降解TSNA菌株AS97的分离筛选、鉴定及应用%Identification and primary application of TSNA degrading bacterial strain AS97 isolated from aging tobacco leaves

    Institute of Scientific and Technical Information of China (English)

    单宏英; 陈德鑫; 李晶; 陈太春; 胡怀喜; 郭志刚; 安德荣

    2011-01-01

    selective medium. The strain was identified by morphological, physio-biochemical characteristics and 16S rRNA gene sequence analysis. The concentration of 4-( methylnitrosamino ) -l-( 3-pyridy ) -1-butanone ( NNK ) , N-nitrosonicotine ( NNN ) , N-nitrosoanatabine ( NAT ) and N-nitrosoanabasine ( NAB ) were determined by LC-MS/MS. The fermentation broth of strain AS97 was spraied on the leaves of tobacco to define inoculum concentration and fermentation condition. [Results] AS97 was identified as Pseudomonas fluorescens ( Genbank accession number; JF 449445). Under the optimal growth conditions with inoculum concentration of 5% , at 30℃ for 10 d, AS97 had high biological activity against NNK and NNN with a degradation rate of 59. 08% and 38. 79% , respectively. The correlation analysis displayed a pronounced correlation(p >0. 01) among the concentration of nitrate, nitrite and TSNA. Furthermore, the results also exhibited that nitrate and nitrite were antecedent substance of TSNA. [Conclusion] These results indicated that Pseudomonas fluorescens AS97 could be a promising microorganism in the practice of non-harmful cigarette production.

  17. Impact of in Situ Isolated Bacterial Strains on Nitrogen Fixation in Alfalfa

    OpenAIRE

    Carmen Dragomir; Rodica Schipor; Neculai Dragomir; Nicoleta Moraru; Claudiu Ghiocel; Darius Văcariu

    2013-01-01

    Symbiosis relationships among legumes and nitrogen fixing bacteria play a crucial role in agriculture since they provide the opportunity of converting atmospheric molecular nitrogen into an ammonia form of nitrogen that the plants can use in protein formation. To enhance this process we have selected nitrogen fixing bacterial strains commercialised under different forms depending on the cultivation technologies in legume species. In our research, we have pointed out the efficacy of in situ is...

  18. Bacterial Cellulose Production by Acetobacter xylinum Strains from Agricultural Waste Products

    Science.gov (United States)

    Kongruang, Sasithorn

    Bacterial cellulose is a biopolysaccharide produced from the bacteria, Acetobacter xylinum. Static batch fermentations for bacterial cellulose production were studied in coconut and pineapple juices under 30 °C in 5-1 fermenters by using three Acetobacter strains: A. xylinum TISTR 998, A. xylinum TISTR 975, and A. xylinum TISTR 893. Experiments were carried out to compare bacterial cellulose yields along with growth kinetic analysis. Results showed that A. xylinum TISTR 998 produced a bacterial cellulose yield of 553.33 g/l, while A. xylinum TISTR 893 produced 453.33 g/l and A. xylinum TISTR 975 produced 243.33 g/l. In pineapple juice, the yields for A. xylinum TISTR 893, 975, and 998 were 576.66, 546.66, and 520 g/l, respectively. The strain TISTR 998 showed the highest productivity when using coconut juice. Morphological properties of cellulose pellicles, in terms of texture and color, were also measured, and the textures were not significantly different among treatments.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

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

  20. Screening of Bacterial Strains for Polygalacturonase Activity: Its Production by Bacillus sphaericus (MTCC 7542

    Directory of Open Access Journals (Sweden)

    Ranveer Singh Jayani

    2010-01-01

    Full Text Available At present almost all the pectinolytic enzymes used for industrial applications are produced by fungi. There are a few reports of pectinase production by bacterial strains. Therefore, in the present study, seventy-four bacterial strains, isolated from soil and rotten vegetable samples, were screened for polygalacturonase production. The strain PG-31, which gave maximum activity, was identified as Bacillus sphaericus (MTCC 7542. Maximal quantities of polygalacturonase were produced when a 16-hours-old inoculum was used at 7.5% (v/v in production medium and incubated in shaking conditions (160 rpm for 72 hours. The optimal temperature and pH for bacterial growth and polygalacturonase production were found to be 30∘C and 6.8, respectively. Maximum enzyme production resulted when citrus pectin was used as the carbon source at a concentration of 1.25% (w/v, whereas other carbon sources led to a decrease (30%–70% in enzyme production. Casein hydrolysate and yeast extract used together as organic nitrogen source gave best results, and ammonium chloride was found to be the most suitable inorganic nitrogen source. The supplementation of media with 0.9% (w/v D-galacturonic acid led to a 23% increase in activity. Bacillus sphaericus, a bacterium isolated from soil, produced good amount of polygalacturonase activity at neutral pH; hence, it would be potentially useful to increase the yield of banana, grape, or apple juice.

  1. Interaction between selected bacterial strains and Arabidopsis halleri modulates shoot proteome and cadmium and zinc accumulation.

    Science.gov (United States)

    Farinati, Silvia; DalCrso, Giovanni; Panigati, Monica; Furini, Antonella

    2011-06-01

    The effects of plant-microbe interactions between the hyperaccumulator Arabidopsis halleri and eight bacterial strains, isolated from the rhizosphere of A. halleri plants grown in a cadmium- and zinc-contaminated site, were analysed for shoot metal accumulation, shoot proteome, and the transcription of genes involved in plant metal homeostasis and hyperaccumulation. Cadmium and zinc concentrations were lower in the shoots of plants cultivated in the presence of these metals plus the selected bacterial strains compared with plants grown solely with these metals or, as previously reported, with plants grown with these metals plus the autochthonous rhizosphere-derived microorganisms. The shoot proteome of plants cultivated in the presence of these selected bacterial strains plus metals, showed an increased abundance of photosynthesis- and abiotic stress-related proteins (e.g. subunits of the photosynthetic complexes, Rubisco, superoxide dismutase, and malate dehydrogenase) counteracted by a decreased amount of plant defence-related proteins (e.g. endochitinases, vegetative storage proteins, and β-glucosidase). The transcription of several homeostasis genes was modulated by the microbial communities and by Cd and Zn content in the shoot. Altogether these results highlight the importance of plant-microbe interactions in plant protein expression and metal accumulation and emphasize the possibility of exploiting microbial consortia for increasing or decreasing shoot metal content.

  2. Interaction between selected bacterial strains and Arabidopsis halleri modulates shoot proteome and cadmium and zinc accumulation

    Science.gov (United States)

    Panigati, Monica; Furini, Antonella

    2011-01-01

    The effects of plant–microbe interactions between the hyperaccumulator Arabidopsis halleri and eight bacterial strains, isolated from the rhizosphere of A. halleri plants grown in a cadmium- and zinc-contaminated site, were analysed for shoot metal accumulation, shoot proteome, and the transcription of genes involved in plant metal homeostasis and hyperaccumulation. Cadmium and zinc concentrations were lower in the shoots of plants cultivated in the presence of these metals plus the selected bacterial strains compared with plants grown solely with these metals or, as previously reported, with plants grown with these metals plus the autochthonous rhizosphere-derived microorganisms. The shoot proteome of plants cultivated in the presence of these selected bacterial strains plus metals, showed an increased abundance of photosynthesis- and abiotic stress-related proteins (e.g. subunits of the photosynthetic complexes, Rubisco, superoxide dismutase, and malate dehydrogenase) counteracted by a decreased amount of plant defence-related proteins (e.g. endochitinases, vegetative storage proteins, and β-glucosidase). The transcription of several homeostasis genes was modulated by the microbial communities and by Cd and Zn content in the shoot. Altogether these results highlight the importance of plant-microbe interactions in plant protein expression and metal accumulation and emphasize the possibility of exploiting microbial consortia for increasing or decreasing shoot metal content. PMID:21357773

  3. Lignin degradation, ligninolytic enzymes activities and exopolysaccharide production by Grifola frondosa strains cultivated on oak sawdust

    Directory of Open Access Journals (Sweden)

    Nona A Mikiashvili

    2011-09-01

    Full Text Available Fourteen strains of Grifola frondosa (Dicks. S. F. Gray, originating from different regions (Asia, Europe and North America were tested for lignin degradation, ligninolytic enzyme activities, protein accumulation and exopolysaccharide production during 55 days of cultivation on oak sawdust. Lignin degradation varied from 2.6 to7.1 % of dry weight of the oak sawdust substrate among tested strains. The loss of dry matter in all screened fungi varied between 11.7 and 33.0%, and the amount of crude protein in the dry substrate varied between 0.94 to 2.55%. The strain, MBFBL 596, had the highest laccase activity (703.3 U/l, and the maximum peroxidase activity of 22.6 U/l was shown by the strain MBFBL 684. Several tested strains (MBFBL 21, 638 and 662 appeared to be good producers of exopolysaccharides (3.5, 3.5 and 3.2 mg/ml respectively.

  4. Selection of oleuropein-degrading lactic acid bacteria strains isolated from fermenting Moroccan green olives

    Energy Technology Data Exchange (ETDEWEB)

    Ghabbour, N.; Lamzira, Z.; Thonart, P.; Cidalia, P.; Markaouid, M.; Asehraoua, A.

    2011-07-01

    A total of 177 strains of lactic acid bacteria (LAB) were isolated from early-stage Moroccan Picholine green olive fermentation, including Lactobacillus plantarum (44.63%), Lactobacillus pentosus (25.99%), Lactobacillus brevis (9.61%) and Pediococcus pentosaceus (19.77%). All the isolates were screened for their tolerance to olive leaf extract and oleuropein. Most of the isolates (85.3%) were found able to degrade oleuropein, when evaluated by either oleuropein or 5-Bromo-4-chloro-3-indolyl {beta}-D-glucuronide (X-Gluc) as substrates. The biodegradation capacity of the selected strains of each species was confirmed by HPLC analysis. (Author).

  5. Rhodococcus aetherivorans IAR1, a new bacterial strain synthesizing poly(3-hydroxybutyrate-co-3-hydroxyvalerate) from toluene.

    Science.gov (United States)

    Hori, Katsutoshi; Kobayashi, Atsushi; Ikeda, Hiroshi; Unno, Hajime

    2009-02-01

    Toluene is the volatile organic compound (VOC) that is most abundantly emitted to the environment. Here, we report a new bacterial strain, IAR1, which synthesizes polyhydroxyalkanoate (PHA) from toluene as the sole carbon source. Using physiological tests and phylogenetic analysis, IAR1 was identified as Rhodococcus aetherivorans. Degradation of toluene by resting IAR1 cells followed Michaelis-Menten kinetics. The determined kinetic parameters showed that the degradation ability of IAR1 is slightly lower than that of Acinetobacter sp. Tol 5, which is highly effective for removing toluene from off-gas. PHA synthesized by IAR1 was identified as poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) by 1H NMR and gas chromatography. During fed-batch cultivation of resting IAR1 cells, the principal monomer unit shifted from 3-hydroxybutyrate to 3-hydroxyvalerate. PHBV shows flexibility and toughness comparable to conventional thermoplastics, but its production usually requires supplying expensive precursors as a secondary carbon source. Therefore, employment of R. aetherivorans IAR1 in the production of PHBV from toluene as the sole carbon source is an attractive means for production of the practical copolymer. In addition, the utilization of waste toluene as a raw material for the polymer production will achieve further cost reduction alongside the effective utilization of waste material.

  6. Characterization of a Novel Mesophilic Bacterial Amylase Secreted by ZW2531-1,a Strain Newly Isolated from Soil

    Institute of Scientific and Technical Information of China (English)

    WANG Yang; LI Fan; GAO Chao-hui; ZHANG Ying-Jiu

    2009-01-01

    A novel mesophilic bacterial amylase,named oligosaccharide-producing multifunctional amylase(OPMA),was discovered and characterized.OPMA is an extracellular enzyme secreted by ZW2531-1,a strain newly isolated from Chinese soil.It could be purified to homogeneity from the culture supematant of ZW2531-1 by 30%-60% saturated ammonium sulfate precipitation,followed by twice Sephadex gel filtration chromatography.OPMA is a 66 kDa protein based on SDS-PAGE and has an isoelectric point(p/) at pH=5.3 by Isoelectric focusing electrophoresis(IFE),it only catalyzes the degradation of starch,rather than other alpha-1,4-and/or 1,6-glucan polysaccharides such as β-cyclomaltodextrin and pullulan.OPMA degraded starch to produce several oligosccharides including maltose,maltotriose,and isomaltotriose as the major end-products,and perhaps other oligosaccharides such as isomaltotetraose,rather than glucose.OPMA exhibited optimal catalytic activity at a reaction temperature of 50 ℃ and pH=6.0,as determined by orthogonal test.Under the optimal reaction conditions,purified OPMA had a specific activity of 13.75 U/mg.These findings suggest that OPMA could be used for the production of some oligosaccharides beneficial to the food industry and medicine.

  7. Effects of surfactants on bacteria and the bacterial degradation of alkanes in crude oil

    Energy Technology Data Exchange (ETDEWEB)

    Bruheim, Per

    1998-12-31

    This thesis investigates the effects of surfactants on the bacterial degradation of alkanes in crude oil. Several alkane oxidising Gram positive and Gram negative were tested for their abilities to oxidise alkanes in crude oil emulsified with surfactants. The surfactants used to make the oil in water emulsions were either of microbial or chemical origin. Oxidation rates of resting bacteria oxidising various crude oil in water emulsions were measured by Warburg respirometry. The emulsions were compared with non-emulsified oil to see which was the preferred substrate. The bacteria were pregrown to both the exponential and stationary phase of growth before harvesting and preparation for the Warburg experiments. 123 refs., 4 figs., 14 tabs.

  8. Plant-associated bacterial degradation of toxic organic compounds in soil.

    LENUS (Irish Health Repository)

    McGuinness, Martina

    2009-08-01

    A number of toxic synthetic organic compounds can contaminate environmental soil through either local (e.g., industrial) or diffuse (e.g., agricultural) contamination. Increased levels of these toxic organic compounds in the environment have been associated with human health risks including cancer. Plant-associated bacteria, such as endophytic bacteria (non-pathogenic bacteria that occur naturally in plants) and rhizospheric bacteria (bacteria that live on and near the roots of plants), have been shown to contribute to biodegradation of toxic organic compounds in contaminated soil and could have potential for improving phytoremediation. Endophytic and rhizospheric bacterial degradation of toxic organic compounds (either naturally occurring or genetically enhanced) in contaminated soil in the environment could have positive implications for human health worldwide and is the subject of this review.

  9. Investigating bacterial populations in styrene-degrading biofilters by 16S rDNA tag pyrosequencing.

    Science.gov (United States)

    Portune, Kevin J; Pérez, M Carmen; Álvarez-Hornos, F Javier; Gabaldón, Carmen

    2015-01-01

    Microbial biofilms are essential components in the elimination of pollutants within biofilters, yet still little is known regarding the complex relationships between microbial community structure and biodegradation function within these engineered ecosystems. To further explore this relationship, 16S rDNA tag pyrosequencing was applied to samples taken at four time points from a styrene-degrading biofilter undergoing variable operating conditions. Changes in microbial structure were observed between different stages of biofilter operation, and the level of styrene concentration was revealed to be a critical factor affecting these changes. Bacterial genera Azoarcus and Pseudomonas were among the dominant classified genera in the biofilter. Canonical correspondence analysis (CCA) and correlation analysis revealed that the genera Brevundimonas, Hydrogenophaga, and Achromobacter may play important roles in styrene degradation under increasing styrene concentrations. No significant correlations (P > 0.05) could be detected between biofilter operational/functional parameters and biodiversity measurements, although biological heterogeneity within biofilms and/or technical variability within pyrosequencing may have considerably affected these results. Percentages of selected bacterial taxonomic groups detected by fluorescence in situ hybridization (FISH) were compared to results from pyrosequencing in order to assess the effectiveness and limitations of each method for identifying each microbial taxon. Comparison of results revealed discrepancies between the two methods in the detected percentages of numerous taxonomic groups. Biases and technical limitations of both FISH and pyrosequencing, such as the binding of FISH probes to non-target microbial groups and lack of classification of sequences for defined taxonomic groups from pyrosequencing, may partially explain some differences between the two methods.

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

    Science.gov (United States)

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

    2014-04-01

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

  11. Screening for a new Streptomyces strain capable of efficient keratin degradation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Keratinous wastes could be degraded by some microorganisms in nature.Native human foot skin (NHFS) was used as sole nitrogen source to screen microorganisms with keratin-degrading capability.From approximately 200 strains,a strain of Streptomyces sp.strain No.16 was found to possess the strongest keratinolytic activity,and the total activity in the culture was 110 KU/ml with specific activity of 2870 KU/mg protein (KU:keratinase unit).Substrate specificity test indicated that the crude keratinase could degrade keratin azure,human hair,cock feathers and collagen.The optimal pH of the crude keratinase ranged from 7.5 to 10 and the temperature ranged from 40℃ to 55℃.Metal chelating agent ethylenediamine tetraacetic acid obviously stimulated the keratinolytic activity but suppressed the proteolytic activity.To our knowledge.this is the first report on specific induction of kemtinases by NHFS from an actinomycete.Moreover,excellent characteristics of its crude keratinase may lead to the potential application in waste treatment and recovery,poultry and leather industry,medicine,and cosmetic development.

  12. Survival of model bacterial strains and helminth eggs in the course of mesophilic anaerobic digestion of pig slurry.

    Science.gov (United States)

    Juris, P; Tóth, F; Lauková, A; Plachý, P; Dubinský, P; Sokol, J

    1996-05-01

    The effect of methanogenesis on the survival of model bacterial strains (Escherichia coli EC 5, Staphylococcus aureus SA 11, Enterococcus faecium CCM 4231) and non-embryonated helminth eggs (Ascaris suum) was investigated in pig slurry. Two pilot-plant experiments were carried out in two anaerobic digesters (800 and 1,000 litre) in a mesophilic thermal range (35-37 degrees C). The mean hydraulic retention time of the digesters was 20 days. The methanogenesis process was monitored by determining the following chemical parameters: pH, N-NH3, total dry matter (kg/day), organic matter (kg/day) production of methane by supplied and degraded organic matter (m3/kg). The results obtained allow us to state that the anaerobic stabilization of pig slurry in the mesophilic temperature range resulted in total devitalization of model bacterial strains E. coli EC 5 and Ent. faecium CCM 4231. St. aureus SA 11 cells, exposed to the above mentioned conditions, were also reduced in their number from 10.04 to 3.27 and from 8.69 to 2.77 log cfu/ml. It is assumed that the longer retention time of excrements in the digester could also result in total devitalization of St. aureus SA 11 cells. From the microbiological point of view, the above mentioned facts indicate a sufficient hygienization effect of the anaerobic fermentation on the contaminated pig excrements. The survival of A. suum eggs was little affected by the 20-day anaerobic mesophilic digestion of pig slurry. Only 17 or 18% (F1, F2) of the non-embryonated A. suum eggs were damaged after the 20-day exposure.

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

    Directory of Open Access Journals (Sweden)

    Soares Márcia M.C.N.

    1999-01-01

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

  14. Functional diversity of bacterial genes associated with aromatic hydrocarbon degradation in anthropogenic dark earth of Amazonia

    Directory of Open Access Journals (Sweden)

    Mariana Gomes Germano

    2012-05-01

    Full Text Available The objective of this work was to evaluate the catabolic gene diversity for the bacterial degradation of aromatic hydrocarbons in anthropogenic dark earth of Amazonia (ADE and their biochar (BC. Functional diversity analyses in ADE soils can provide information on how adaptive microorganisms may influence the fertility of soils and what is their involvement in biogeochemical cycles. For this, clone libraries containing the gene encoding for the alpha subunit of aromatic ring-hydroxylating dioxygenases (α-ARHD bacterial gene were constructed, totaling 800 clones. These libraries were prepared from samples of an ADE soil under two different land uses, located at the Caldeirão Experimental Station - secondary forest (SF and agriculture (AG -, and the biochar (SF_BC and AG_BC, respectively. Heterogeneity estimates indicated greater diversity in BC libraries; and Venn diagrams showed more unique operational protein clusters (OPC in the SF_BC library than the ADE soil, which indicates that specific metabolic processes may occur in biochar. Phylogenetic analysis showed unidentified dioxygenases in ADE soils. Libraries containing functional gene encoding for the alpha subunit of the aromatic ring-hydroxylating dioxygenases (ARHD gene from biochar show higher diversity indices than those of ADE under secondary forest and agriculture.

  15. Bacterial strains from floodplain soils perform different plant-growth promoting processes and enhance cowpea growth

    Directory of Open Access Journals (Sweden)

    Elaine Martins da Costa

    2016-08-01

    Full Text Available ABSTRACT Certain nodulating nitrogen-fixing bacteria in legumes and other nodule endophytes perform different plant-growth promoting processes. The objective of this study was to evaluate 26 bacterial strains isolated from cowpea nodules grown in floodplain soils in the Brazilian savannas, regarding performance of plant-growth promoting processes and ability to enhance cowpea growth. We also identified these strains by 16S rRNA sequencing. The following processes were evaluated: free-living biological nitrogen fixation (BNF, solubilization of calcium, aluminum and iron phosphates and production of indole-3-acetic acid (IAA. The abilities to nodulate and promote cowpea growth were evaluated in Leonard jars. Partial sequencing of the 16S rRNA gene identified 60 % of the strains as belonging to genus Paenibacillus. The following four genera were also identified: Bacillus, Bradyrhizobium, Enterobacter and Pseudomonas. None of the strains fixed N2 free-living. Among the strains, 80 % solubilized Ca phosphate and one solubilized Al phosphate and none solubilized Fe phosphate. The highest IAA concentrations (52.37, 51.52 and 51.00 μg mL−1 were obtained in the 79 medium with tryptophan by Enterobacter strains UFPI B5-7A, UFPI B5-4 and UFPI B5-6, respectively. Only eight strains nodulated cowpea, however, all increased production of total dry matter. The fact that the strains evaluated perform different biological processes to promote plant growth indicates that these strains have potential use in agricultural crops to increase production and environmental sustainability.

  16. Characterization of a novel β-cypermethrin-degrading Aspergillus niger YAT strain and the biochemical degradation pathway of β-cypermethrin.

    Science.gov (United States)

    Deng, Weiqin; Lin, Derong; Yao, Kai; Yuan, Huaiyu; Wang, Zhilong; Li, Jianlong; Zou, Likou; Han, Xinfeng; Zhou, Kang; He, Li; Hu, Xinjie; Liu, Shuliang

    2015-10-01

    Aspergillus niger YAT strain was obtained from Chinese brick tea (Collection number: CGMCC 10,568) and identified on the basis of morphological characteristics and internal transcribed spacer (ITS) sequence. The strain could degrade 54.83 % of β-cypermethrin (β-CY; 50 mg L(-1)) in 7 days and 100 % of 3-phenoxybenzoic acid (3-PBA; 100 mg L(-1)) in 22 h. The half-lives of β-CY and 3-PBA range from 3.573 to 11.748 days and from 5.635 to 12.160 h, respectively. The degradation of β-CY and 3-PBA was further described using first-order kinetic models. The pathway and mechanism of β-CY degraded by YAT were investigated by analyzing the degraded metabolites through high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS). Relevant enzymatic activities and substrate utilization were also investigated. β-CY degradation products were analyzed. Results indicated that YAT strain transformed β-CY into 3-PBA. 3-PBA was then gradually transformed into permethric acid, protocatechuic acid, 3-hydroxy-5-phenoxy benzoic acid, gallic acid, and phenol gradually. The YAT strain can also effectively degrade these metabolites. The results indicated that YAT strain has potential applications in bioremediation of pyrethroid insecticide (PI)-contaminated environments and fermented food.

  17. Isolation and characterization of atrazine-degrading Arthrobacter sp. AD26 and use of this strain in bioremediation of contaminated soil

    Institute of Scientific and Technical Information of China (English)

    LI Qingyan; LI Ying; ZHU Xikun; CAI Baoli

    2008-01-01

    A bacterial strain (AD26) capable of utilizing atrazine as a sole nitrogen source for growth was isolated from an industrial wastewatersample by enrichment culture. The 16S rRNA gene sequencing identified AD26 as anArthrobacter sp. PCR assays indicated that AD26contained atrazine-degrading genes trzN and atzBC. The trzN gene of AD26 only differs from the trzN ofArthrobacter aurescens TC1by one base (A→T at 907) and one amino acid (Met→Leu at 303). The specific activity of trzN of AD26 in crude cell extract was0.28 U/mg, which was 1.2 times that of TC 1. This strain has shown faster growth and atrazine-degradation rates in atrazine-containingminimal media than two well characterized atrazine-degrading bacteria, Pseudomonas sp. ADP and Arthrobacter aurescens TC 1. Afterincubating for 48 h at 30℃, the OD600 of AD26 reached 2.6 compared with 1.33 of ADP. AD26 was capable of degrading 500 mg/Lof atrazine in minimal medium at 95% in 72 h, while the degradative rates by TC1 and ADP were only 90% and 86%, respectively. Abioremediation trial of contaminated soil has indicated that AD26 can degrade as high as 98% of atrazine contained in soil (300 mg/kg)after incubating for 20 d at 26℃, nominating this strain as a good candidate for use in bioremediation programs.

  18. Recombination-prone bacterial strains form a reservoir from which epidemic clones emerge in agroecosystems.

    Science.gov (United States)

    Merda, Déborah; Bonneau, Sophie; Guimbaud, Jean-François; Durand, Karine; Brin, Chrystelle; Boureau, Tristan; Lemaire, Christophe; Jacques, Marie-Agnès; Fischer-Le Saux, Marion

    2016-04-05

    The acquisition of virulence-related genes through horizontal gene transfer can modify the pathogenic profiles of strains and lead to the emergence of new diseases. Xanthomonas arboricola is a bacterial species largely known for the damage it causes to stone and nut fruit trees worldwide. In addition to these host-specific populations called pathovars, many nonpathogenic strains have been identified in this species. Their evolutionary significance in the context of pathogen emergence is unknown. We looked at seven housekeeping genes amplified from 187 pathogenic and nonpathogenic strains isolated from various plants worldwide to analyze population genetics and recombination dynamics. We also examined the dynamics of the gains and losses of genes associated with life history traits (LHTs) during X. arboricola evolution. We discovered that X. arboricola presents an epidemic population structure. Successful pathovars of trees (i.e., pruni, corylina, and juglandis) are epidemic clones whose emergence appears to be linked to the acquisition of eight genes coding for Type III effectors. The other strains of this species are part of a recombinant network, within which LHT-associated genes might have been lost. We suggest that nonpathogenic strains, because of their high genetic diversity and propensity for recombination, may promote the emergence of pathogenic strains. This article is protected by copyright. All rights reserved. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  19. Isolation, development and identification of salt-tolerant bacterial consortium from crude-oil-contaminated soil for degradation of di-azo dye Reactive Blue 220.

    Science.gov (United States)

    Patel, Vipul R; Bhatt, Nikhil

    2015-01-01

    The objective of this study was development and characterization of a halophilic bacterial consortium for rapid decolorization and degradation of a wide range of dyes and their mixtures. The 16S rRNA gene analysis of developed halophilic consortium VN.1 showed that the bacterial consortium contained six bacterial strains, which were identified as Pseudomonas fluorescens HM480360, Enterobacter aerogenes HM480361, Shewanella sp. HM589853, Arthrobacter nicotianae HM480363, Bacillus beijingensis HM480362 and Pseudomonas aeruginosa JQ659549. Halophilic consortium VN.1 was able to decolorize up to 2,500 mg/L RB220 with >85% chemical oxygen demand (COD) reduction under static condition at 30 °C and pH 8.0 in the presence of 7% NaCl. VN.1 also exhibited more than 85% COD reduction with >25 mg/(L h) rate of decolorization in the case of different reactive dye mixtures. We propose the symmetric cleavage of RB220 using Fourier transform infrared, high-performance liquid chromatography (HPLC), nuclear magnetic resonance and gas chromatography-mass spectrometry analysis, and confirmed the formation of sodium-4-aminobenzenesulfonate, sodium-6-aminonepthalenesulfonate, and sodiumbenzene/nepthalenesulfonate. Toxicity studies confirm that the biodegraded products of RB220 effluent stimulate the growth of plants as well as the bacterial community responsible for soil fertility.

  20. Comparative Genomic and Phenotypic Characterization of Pathogenic and Non-Pathogenic Strains of Xanthomonas arboricola Reveals Insights into the Infection Process of Bacterial Spot Disease of Stone Fruits.

    Science.gov (United States)

    Garita-Cambronero, Jerson; Palacio-Bielsa, Ana; López, María M; Cubero, Jaime

    2016-01-01

    Xanthomonas arboricola pv. pruni is the causal agent of bacterial spot disease of stone fruits, a quarantinable pathogen in several areas worldwide, including the European Union. In order to develop efficient control methods for this disease, it is necessary to improve the understanding of the key determinants associated with host restriction, colonization and the development of pathogenesis. After an initial characterization, by multilocus sequence analysis, of 15 strains of X. arboricola isolated from Prunus, one strain did not group into the pathovar pruni or into other pathovars of this species and therefore it was identified and defined as a X. arboricola pv. pruni look-a-like. This non-pathogenic strain and two typical strains of X. arboricola pv. pruni were selected for a whole genome and phenotype comparative analysis in features associated with the pathogenesis process in Xanthomonas. Comparative analysis among these bacterial strains isolated from Prunus spp. and the inclusion of 15 publicly available genome sequences from other pathogenic and non-pathogenic strains of X. arboricola revealed variations in the phenotype associated with variations in the profiles of TonB-dependent transporters, sensors of the two-component regulatory system, methyl accepting chemotaxis proteins, components of the flagella and the type IV pilus, as well as in the repertoire of cell-wall degrading enzymes and the components of the type III secretion system and related effectors. These variations provide a global overview of those mechanisms that could be associated with the development of bacterial spot disease. Additionally, it pointed out some features that might influence the host specificity and the variable virulence observed in X. arboricola.

  1. Screening of Lignocellulose-Degrading Superior Mushroom Strains and Determination of Their CMCase and Laccase Activity

    Directory of Open Access Journals (Sweden)

    Li Fen

    2014-01-01

    Full Text Available In order to screen lignocellulose-degrading superior mushroom strains ten strains of mushrooms (Lentinus edodes939, Pholiota nameko, Lentinus edodes868, Coprinus comatus, Macrolepiota procera, Auricularia auricula, Hericium erinaceus, Grifola frondosa, Pleurotus nebrodensis, and Shiraia bambusicola were inoculated onto carboxymethylcellulose agar-Congo red plates to evaluate their ability to produce carbomethyl cellulase (CMCase. The results showed that the ratio of transparent circle to mycelium circle of Hericium erinaceus was 8.16 (P<0.01 higher than other strains. The filter paper culture screening test showed that Hericium erinaceus and Macrolepiota procera grew well and showed extreme decomposition of the filter paper. When cultivated in guaiacol culture medium to detect their abilities to secrete laccase, Hericium erinaceus showed the highest ability with the largest reddish brown circles of 4.330 cm. CMCase activity determination indicated that Coprinus comatus and Hericium erinaceus had the ability to produce CMCase with 33.92 U/L on the 9th day and 22.58 U/L on the 10th day, respectively, while Coprinus comatus and Pleurotus nebrodensis had the ability to produce laccase with 496.67 U/L and 489.17 U/L on the 16th day and 18th day. Based on the results, Coprinus comatus might be the most promising lignocellulose-degrading strain to produce both CMCase and laccase at high levels.

  2. Keratinase production and keratin degradation by a mutant strain of Bacillus subtilis

    Institute of Scientific and Technical Information of China (English)

    Cheng-gang CAI; Bing-gan LOU; Xiao-dong ZHENG

    2008-01-01

    A new feather-degrading bacterium was isolated from a local feather waste site and identified as Bacillus subtilis based on morphological, physiochemical, and phylogenetic characteristics. Screening for mutants with elevated keratinolytic activity using N-methyl-N'-nitro-N-nitrosoguanidine mutagenesis resulted in a mutant strain KD-N2 producing keratinolytic activity about 2.5 times that of the wild-type strain. The mutant strain produced inducible keratinase in different substrates of feathers, hair, wool and silk under submerged cultivation. Scanning electron microscopy studies showed the degradation of feathers, hair and silk by the keratinase. The optimal conditions for keratinase production include initial pH of 7.5, inoculum size of 2% (v/v), age of inoculum of 16 h, and cultivation at 23 ℃. The maximum keratinolytic activity of KD-N2 was achieved after 30 h. Essential amino acids like threonine, valine, methionine as well as ammonia were produced when feathers were used as substrates. Strain KD-N2,therefore, shows great promise of finding potential applications in keratin hydrolysis and keratinase production.

  3. Tannin degradation by a novel tannase enzyme present in some Lactobacillus plantarum strains.

    Science.gov (United States)

    Jiménez, Natalia; Esteban-Torres, María; Mancheño, José Miguel; de Las Rivas, Blanca; Muñoz, Rosario

    2014-05-01

    Lactobacillus plantarum is frequently isolated from the fermentation of plant material where tannins are abundant. L. plantarum strains possess tannase activity to degrade plant tannins. An L. plantarum tannase (TanBLp, formerly called TanLp1) was previously identified and biochemically characterized. In this study, we report the identification and characterization of a novel tannase (TanALp). While all 29 L. plantarum strains analyzed in the study possess the tanBLp gene, the gene tanALp was present in only four strains. Upon methyl gallate exposure, the expression of tanBLp was induced, whereas tanALp expression was not affected. TanALp showed only 27% sequence identity to TanBLp, but the residues involved in tannase activity are conserved. Optimum activity for TanALp was observed at 30°C and pH 6 in the presence of Ca(2+) ions. TanALp was able to hydrolyze gallate and protocatechuate esters with a short aliphatic alcohol substituent. Moreover, TanALp was able to fully hydrolyze complex gallotannins, such as tannic acid. The presence of the extracellular TanALp tannase in some L. plantarum strains provides them an advantage for the initial degradation of complex tannins present in plant environments.

  4. Biodegradation of oil spill by petroleum refineries using consortia of novel bacterial strains.

    Science.gov (United States)

    Singh, Bina; Bhattacharya, Amit; Channashettar, Veeranna A; Jeyaseelan, C Paul; Gupta, Sachin; Sarma, Priyangshu M; Mandal, Ajoy K; Lal, Banwari

    2012-08-01

    Feasibility study carried out at the site prior to the full scale study showed that the introduced bacterial consortium effectively adapted to the local environment of the soil at bioremediation site. The soil samples were collected from the contaminated fields after treatment with bacterial consortium at different time intervals and analyzed by gas chromatography after extraction with hexane and toluene. At time zero (just before initiation of bioremediation), the concentration of total petroleum hydrocarbons in the soil (25-cm horizon) of plot A, B, C and D was 30.90 %, 18.80 %, 25.90 % and 29.90 % respectively, after 360 days of treatment with microbial consortia was reduced to 0.97 %, 1.0 %, 1.0 %, and 1.1 % respectively. Whereas, only 5 % degradation was observed in the control plot after 365 days (microbial consortium not applied).

  5. [Raoultella planticola, a new strain degrading 2,4,5-trichlorophenoxyacetic acid].

    Science.gov (United States)

    Zharikova, N V; Markusheva, T V; Galkin, E G; Korobov, V V; Zhurenko, E Iu; Sitdikova, L R; Kolganova, T V; Kuznetsov, B B; Turova, T P

    2006-01-01

    A new strain that degrades the herbicide 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) was isolated from soil, which was exposed to factors related to the petrochemical industry. According to its physiological, biochemical, cultural, and morphological traits, together with the sequence of the 16S rRNA gene, the strain was identified as Raoultella planticola 33-4ch. The strain could consume 2,4,5-T as a sole source of carbon and energy. The amount of 2,4,5-T in the culture medium decreased by 51% after five days of incubation. Raoultella planticola 33-4ch consumes 2,4,5-T to produce 4-chlorophenoxyacetic, phenoxyacetic, and 3-methyl-2,6-dioxo-4-hexenoic acids.

  6. Life in oil :Hydrocarbon-degrading bacterial mineralization in oil spill-polluted marine environment

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    play the greatest role under neutral to alkaline condition (pH;7-7.8).On the contrary,when pH shifted to acidic (pH;2-4) levels,the fungi took over to degrade heavy oil.During the period,the aliphatic hydrocarbons were reduced significantly but the aromatic hydrocarbons remained relatively constant even after 429 days of bioremediation.Experimental study was undertaken to investigate the bioavailability of kaolinite clay minerals and the role they play in seawater polluted with the Nakhodka oil spill.TEM/EDS imaging suggested that the clays present in oil-polluted seawater were capable of stimulating oildegrading bacteria probably because Si from clays facilitates bacterial usage of oil and C-O-Na-Si complexes on the surfaces of bacterial cell walls are a stimulator for oildegrading bacterial growth in seawater contaminated with the Nakhodka oil spill.

  7. High Chromium Tolerant Bacterial Strains from Palar River Basin: Impact of Tannery Pollution

    Directory of Open Access Journals (Sweden)

    K. Sundar

    2010-04-01

    Full Text Available The basic survey study on tanneries and its pollution in the Palar river basin of Vellore District showed that it has been contaminated with heavy metals especially chromium and salts. This study is to improve our understanding to find the Cr contamination level and the ecology of heavy metal tolerance of the native bacterial flora of our study area. Chromium tolerant strains were isolated from contaminated sediments, water and effluents of various tanneries. The minimum and maximum concentration of chromium sediments was in the range of 47.4 and 682.4 mg/L, with an average of 306.285 mg/L in the study area. Sixty-eight chromium resistant bacterial strains were isolated and Maximum Tolerance Concentration (MTC studies have indicated that the tolerance concentrations of the isolates were in the range of 100-3300 mg/L. These bacterial isolates were also checked for their resistance to other heavy metals like Ni, Pb, Zn, Fe and Cd. Eighty percent of the isolates showed resistance to Ni, Pb, Zn, Fe at 100 ppm level and 45% had shown resistance to Cd. The isolates also had shown tolerance to salt (NaCl up to 9%. Significant note was found in the concentration of chromium and in the chromium tolerance ability of the bacteria in the study area and these chromium tolerance bacteria can be used as the indicator for the Cr contamination.

  8. Cockroaches as a Source of High Bacterial Pathogens with Multidrug Resistant Strains in Gondar Town, Ethiopia.

    Science.gov (United States)

    Moges, Feleke; Eshetie, Setegn; Endris, Mengistu; Huruy, Kahsay; Muluye, Dagnachew; Feleke, Tigist; G/Silassie, Fisha; Ayalew, Getenet; Nagappan, Raja

    2016-01-01

    Background. Cockroaches are source of bacterial infections and this study was aimed to assess bacterial isolates and their antimicrobial profiles from cockroaches in Gondar town, Ethiopia. Methods. A total of 60 cockroaches were collected from March 1 to May 30, 2014, in Gondar town. Bacterial species were isolated from external and internal parts of cockroaches. Disk diffusion method was used to determine antibiotic susceptibility patterns. Data were entered and analyzed by using SPSS version 20; P values cockroaches, respectively. Klebsiella pneumoniae 32 (17.7%), Escherichia coli 29 (16%), and Citrobacter spp. 27 (15%) were the predominant isolates. High resistance rate was observed to cotrimoxazole, 60 (33.1%), and least resistance rate was noted to ciprofloxacin, 2 (1.1%). Additionally, 116 (64.1%) of the isolates were MDR strains; Salmonella spp. were the leading MDR isolates (100%) followed by Enterobacter (90.5%) and Shigella spp. (76.9%). Conclusion. Cockroaches are the potential source of bacteria pathogens with multidrug resistant strains and hence effective preventive and control measures are required to minimize cockroach related infections.

  9. Saponaria officinalis L. extract: Surface active properties and impact on environmental bacterial strains.

    Science.gov (United States)

    Smułek, Wojciech; Zdarta, Agata; Pacholak, Amanda; Zgoła-Grześkowiak, Agnieszka; Marczak, Łukasz; Jarzębski, Maciej; Kaczorek, Ewa

    2017-02-01

    Plant-derived surfactants are characterised by low toxicity, high biodegradability and environmental compatibility. They therefore have many applications; for instance, they can be used in bioremediation to accelerate biodegradation processes, especially of hydrophobic pollutants. This paper analyses the properties of an extract from Saponaria officinalis L. containing saponins and its impact on bacterial strains isolated from soil, as well as its potential for application in hydrocarbon bioremediation. The tested extract from Saponaria officinalis L. contains gypsogenin, hederagenin, hydroxyhederagenin and quillaic acid aglycone structures and demonstrates good emulsification properties. Contact with the extract led to modification of bacterial cell surface properties. A decrease in cell surface hydrophobicity and an increase in membrane permeability were recorded in the experiments. An increase of up to 63% in diesel oil biodegradation was also recorded for Pseudomonas putida DA1 on addition of 1gL(-1) of saponins from Saponaria officinalis L. Saponaria extract showed no toxic impact on the tested environmental bacterial strains at the concentration used in the biodegradation process. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Genome Sequences of 15 Gardnerella vaginalis Strains Isolated from the Vaginas of Women with and without Bacterial Vaginosis

    Science.gov (United States)

    Robinson, Lloyd S.; Perry, Justin; Lek, Sai; Wollam, Aye; Sodergren, Erica; Weinstock, George

    2016-01-01

    Gardnerella vaginalis is a predominant species in bacterial vaginosis, a dysbiosis of the vagina that is associated with adverse health outcomes, including preterm birth. Here, we present the draft genome sequences of 15 Gardnerella vaginalis strains (now available through BEI Resources) isolated from women with and without bacterial vaginosis. PMID:27688326

  11. Generalist hydrocarbon-degrading bacterial communities in the oil-polluted water column of the North Sea

    NARCIS (Netherlands)

    Chronopoulou, P.M.; Sanni, G.O.; Silas-Olu, D.I.; van der Meer, J.R.; Timmis, K.N.; Brussaard, C.P.D.; McGenity, T.J.

    2015-01-01

    The aim of this work was to determine the effect of light crude oil on bacterial communities during an experimental oil spill in the North Sea and in mesocosms (simulating a heavy, enclosed oil spill), and to isolate and characterize hydrocarbon-degrading bacteria from the water column. No oil-induc

  12. Generalist hydrocarbon-degrading bacterial communities in the oil-polluted water column of the North Sea

    NARCIS (Netherlands)

    Chronopoulou, P.M.; Sanni, G.O.; Silas-Olu, D.I.; van der Meer, J.R.; Timmis, K.N.; Brussaard, C.P.D.; McGenity, T.J.

    2015-01-01

    The aim of this work was to determine the effect of light crude oil on bacterial communities during an experimental oil spill in the North Sea and in mesocosms (simulating a heavy, enclosed oil spill), and to isolate and characterize hydrocarbon-degrading bacteria from the water column. No

  13. 3-Ketosteroid 9 alpha-hydroxylase enzymes : Rieske non-heme monooxygenases essential for bacterial steroid degradation

    NARCIS (Netherlands)

    Petrusma, Mirjan; van der Geize, Robert; Dijkhuizen, Lubbert

    2014-01-01

    Various micro-organisms are able to use sterols/steroids as carbon- and energy sources for growth. 3-Ketosteroid 9 alpha-hydroxylase (KSH), a two component Rieske non-heme monooxygenase comprised of the oxygenase KshA and the reductase KshB, is a key-enzyme in bacterial steroid degradation. It initi

  14. Strain-Dependent Recognition of a Unique Degradation Motif by ClpXP in Streptococcus mutans

    Science.gov (United States)

    Jana, Biswanath; Tao, Liang

    2016-01-01

    ABSTRACT Streptococcus mutans, a dental pathogen, has a remarkable ability to cope with environmental stresses. Under stress conditions, cytoplasmic proteases play a major role in controlling the stability of regulatory proteins and preventing accumulation of damaged and misfolded proteins. ClpXP, a well-conserved cytoplasmic proteolytic system, is crucial in maintaining cellular homeostasis in bacteria. ClpX is primarily responsible for recognition of substrates and subsequent translocation of unfolded substrates into the ClpP proteolytic compartment for degradation. In Escherichia coli, ClpX recognizes distinct motifs present at the C-terminal end of target proteins. However, recognition sequences for ClpXP in other bacteria, including S. mutans, are not known. In this study, using two-dimensional (2D) polyacrylamide gel electrophoresis (PAGE) analysis, we have identified several putative substrates for S. mutans ClpXP. SsbA, which encodes a small DNA binding protein, is one such substrate that is degraded by ClpXP. By sequential deletions, we found that the last 3 C-terminal amino acids, LPF, are sufficient for ClpXP-mediated degradation. Addition of LPF at the C-terminal end of green fluorescent protein (GFP) rendered the protein completely degradable by ClpXP. Alterations of this tripeptide motif impeded ClpXP-mediated degradation. However, recognition of LPF by ClpXP is highly specific to some S. mutans strains (UA159, UA130, and N3209) since not all S. mutans strains recognize the motif. We speculate that an adaptor protein is involved in either substrate recognition or substrate degradation by ClpXP. Nevertheless, this is the first report of a unique recognition sequence for ClpXP in streptococci. IMPORTANCE Regulated proteolysis in bacteria is an important biological process that maintains protein homeostasis. ClpXP, an intracellular proteolytic complex, is the primary protease that is responsible for protein turnover. While the substrates for Clp

  15. Conductivity-Dependent Strain Response of Carbon Nanotube Treated Bacterial Nanocellulose

    Directory of Open Access Journals (Sweden)

    S. Farjana

    2013-01-01

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

  16. The Conditions of Releasing Potassium by a Silicate-dissolving Bacterial Strain NBT

    Institute of Scientific and Technical Information of China (English)

    SHENG Xia-fang; HE Lin-yan; HUANG Wei-yi

    2002-01-01

    The potassium-releasing characteristics of a bacterium from different minerals were studied through pure culture and soil column experiments. The results showed that the strain NBT of tested strains had the highest potassium-releasing capacity. It released 35.2 mg/L after 7days of pure culture incubation at 28℃, 31.8% - 1203.7% more than other tested strains. Potassium released from the minerals was obviously affected by pH, aerobic condition, soil and mineral properties. The strain NBT had a much higher potential to release potassium in the pH 6.5 - 8.0 than other pHs. Living cell inoculation resulted in an increase of 84.8%- 127.9% compared with that of the dead cell inoculation. More aerobic condition produced more K than a less aerobic one. The potassium-releasing order was as follows: illite > feldspar> muscovite. Soil column experiment showed that the bacterial number increased from (2.6 - 3.0) × 106/g to (6.8 - 7.4) × 107/g. Soil available potassium content increased by 31.2- 33.6mg/kg in yellow-brown soil and 21.7mg/kg in paddy soil, when inoculated with the strain NBT, 290.6% and 185.5% increment of the dead cell inoculation soils respectively.

  17. Antimicrobial Activity of Monoramnholipids Produced by Bacterial Strains Isolated from the Ross Sea (Antarctica

    Directory of Open Access Journals (Sweden)

    Pietro Tedesco

    2016-04-01

    Full Text Available Microorganisms living in extreme environments represent a huge reservoir of novel antimicrobial compounds and possibly of novel chemical families. Antarctica is one of the most extraordinary places on Earth and exhibits many distinctive features. Antarctic microorganisms are well known producers of valuable secondary metabolites. Specifically, several Antarctic strains have been reported to inhibit opportunistic human pathogens strains belonging to Burkholderia cepacia complex (Bcc. Herein, we applied a biodiscovery pipeline for the identification of anti-Bcc compounds. Antarctic sub-sea sediments were collected from the Ross Sea, and used to isolate 25 microorganisms, which were phylogenetically affiliated to three bacterial genera (Psychrobacter, Arthrobacter, and Pseudomonas via sequencing and analysis of 16S rRNA genes. They were then subjected to a primary cell-based screening to determine their bioactivity against Bcc strains. Positive isolates were used to produce crude extracts from microbial spent culture media, to perform the secondary screening. Strain Pseudomonas BNT1 was then selected for bioassay-guided purification employing SPE and HPLC. Finally, LC-MS and NMR structurally resolved the purified bioactive compounds. With this strategy, we achieved the isolation of three rhamnolipids, two of which were new, endowed with high (MIC < 1 μg/mL and unreported antimicrobial activity against Bcc strains.

  18. Antimicrobial Activity of Monoramnholipids Produced by Bacterial Strains Isolated from the Ross Sea (Antarctica) †

    Science.gov (United States)

    Tedesco, Pietro; Maida, Isabel; Palma Esposito, Fortunato; Tortorella, Emiliana; Subko, Karolina; Ezeofor, Chidinma Christiana; Zhang, Ying; Tabudravu, Jioji; Jaspars, Marcel; Fani, Renato; de Pascale, Donatella

    2016-01-01

    Microorganisms living in extreme environments represent a huge reservoir of novel antimicrobial compounds and possibly of novel chemical families. Antarctica is one of the most extraordinary places on Earth and exhibits many distinctive features. Antarctic microorganisms are well known producers of valuable secondary metabolites. Specifically, several Antarctic strains have been reported to inhibit opportunistic human pathogens strains belonging to Burkholderia cepacia complex (Bcc). Herein, we applied a biodiscovery pipeline for the identification of anti-Bcc compounds. Antarctic sub-sea sediments were collected from the Ross Sea, and used to isolate 25 microorganisms, which were phylogenetically affiliated to three bacterial genera (Psychrobacter, Arthrobacter, and Pseudomonas) via sequencing and analysis of 16S rRNA genes. They were then subjected to a primary cell-based screening to determine their bioactivity against Bcc strains. Positive isolates were used to produce crude extracts from microbial spent culture media, to perform the secondary screening. Strain Pseudomonas BNT1 was then selected for bioassay-guided purification employing SPE and HPLC. Finally, LC-MS and NMR structurally resolved the purified bioactive compounds. With this strategy, we achieved the isolation of three rhamnolipids, two of which were new, endowed with high (MIC < 1 μg/mL) and unreported antimicrobial activity against Bcc strains. PMID:27128927

  19. Adhesion of different bacterial strains to low-temperature plasma treated biomedical PVC catheter surfaces.

    Science.gov (United States)

    Yousefi Rad, A; Ayhan, H; Kisa, U; Pişkin, E

    1998-01-01

    In this study, firstly five different bacteria (i.e. Coagulase positive and negative staphylococcus, Streptococcus pyogenes, Escherichia coli, Pseudomonas aeruginosa) with their different strains were isolated and used. The contact angle, surface free energy, p-xylene adhesion, and zeta potential of these bacteria were in the range of 43-69 deg, 45.4-61.8 erg cm(-2), 2.3-80.3%, and from -650.2 to + 17.5 mV, respectively. Most of the bacteria were negatively charged. Attachment of these bacteria to PVC catheter and its DMAEMA- and AAc-plasma treated forms were investigated. Bacterial attachment to the hydrophobic PVC catheter was high. Both plasma treatments caused significant drops in bacterial attachment in most of the cases. The effects of AAc-plasma treatment was more significant.

  20. Rhinovirus Infection Induces Degradation of Antimicrobial Peptides and Secondary Bacterial Infection in Chronic Obstructive Pulmonary Disease

    OpenAIRE

    Patrick Mallia; Joseph Footitt; Rosa Sotero; Annette Jepson; Marco Contoli; Maria-Belen Trujillo-Torralbo; Tatiana Kebadze; Julia Aniscenko; Gregory Oleszkiewicz; Katrina Gray; Message, Simon D.; Kazuhiro Ito; Peter J Barnes; Ian M Adcock; Alberto Papi

    2012-01-01

    Rationale: Chronic obstructive pulmonary disease (COPD) exacerbations are associated with virus (mostly rhinovirus) and bacterial infections, but it is not known whether rhinovirus infections precipitate secondary bacterial infections.

  1. Screen and analysis of degradation ability for crude oil degradation strains from South China Sea%南海高效石油降解菌的筛选及降解特性研究

    Institute of Scientific and Technical Information of China (English)

    姜肸; 高伟; 李倩; 崔志松; 张魁英; 郑立

    2012-01-01

    The study was performed to test the petroleum biodegradation ability of 52 bacterial strains using gravimetric method.All of these bacteria were collected from 10 samples of water from the South China Sea.Chemical analysis of biodegradation was accomplished with GC-MS,screening out six strains that had strong de-emulsification and degradation activity.The six bacterial strains was identified using 16S rRNA sequencing.The experimental results show that after screening test using the gravimetric method,the biodegradation rates of six bacterial strains were determined between 20% and 55%.The six selected strains of bacteria were compared to genus-species in Genbank through contrast of the BLAST.Three strains belonged to Bacillus,one strain to Pseudoalteromonas,and one strain to Alteromonas.The six strains showed high degradation rates,up to 40% with alkanes and 70% with polycyclic aromatic hydrocarbon(PAHs).The bacterial strain B08 500 m-3 had the highest rates with 75% reduction of alkanes and 87% degradation of PAHs.%以南海10个采样点采集到的样品为研究材料,以石油降解率为筛选依据,初筛获得52株石油降解菌,从中进一步筛选出6株对石油烃有降解能力的细菌,通过16S rRNA序列分析对筛选得到的6株菌进行初步鉴定,并使用GC-MS内标法测定降解产物,对降解菌的降解特性进行进一步研究.结果表明,采用重量法筛选出来的6株细菌对石油的降解率为20%~55%.与Genbank中的16S rRNA基因序列BLAST对比结果显示,所筛选出的6株菌株中,3株菌株属于芽孢杆菌属(Bacillus),2株菌株属于假交替单胞菌属(Pseudoalteromonas),1株属于交替单胞菌属(Alteromonas).降解特性分析表明,所筛选6株菌的烷烃降解率均在40%以上,多环芳烃降解率均在70%以上,其中,菌株B08500m-3对石油中总烷烃和总芳香烃的降解效果较好,降解率分别为75%和87%.

  2. Biochemical Characterization of 3-Methyl-4-nitrophenol degradation in Burkholderia sp. Strain SJ98

    Directory of Open Access Journals (Sweden)

    Jun eMin

    2016-05-01

    Full Text Available Several strains have been reported to grow on 3-methyl-4-nitrophenol (3M4NP, the primary breakdown product of the excessively used insecticide fenitrothion. However, the microbial degradation of 3M4NP at molecular and biochemical levels remains unknown. Here, methyl-1,4-benzoquinone (MBQ and methylhydroquinone (MHQ,rather than catechol proposed previously, were identified as the intermediates before ring cleavage during 3M4NP degradation by Burkholderia sp. strain SJ98. Real-time quantitative PCR analysis indicated that the pnpABA1CDEF cluster involved in para-nitrophenol (PNP and 2-chloro-4-nitrophenol (2C4NP catabolism was also likely responsible for 3M4NP degradation in this strain. Purified PNP 4-monooxygenase (PnpA is able to catalyze the monooxygenation of 3M4NP to MBQ and exhibited an apparent Km value of 20.3±2.54 μM for 3M4NP, and pnpA is absolutely necessary for the catabolism of 3M4NP by gene knock-out and complementation. PnpB, a 1,4-benzoquinone reductase catalyzes the reduction of MBQ to MHQ, and also found to enhance PnpA activity in vitro in the conversion of 3M4NP to MBQ. By sequential catalysis assays, PnpCD, PnpE and PnpF were likely involved in the lower pathway of 3M4NP catabolism. Although NpcCD, NpcE and NpcF are able to catalyze the sequential conversion of MHQ in vitro, these enzymes are unlikely involved in 3M4NP catabolism because their coding genes were not upregulated by 3M4NP induction in vivo. These results revealed that the enzymes involved in PNP and 2C4NP catabolism were also responsible for 3M4NP degradation in strain SJ98. This fills a gap in our understanding of the microbial degradation of 3M4NP at molecular and biochemical levels and also provides another example to illustrate the adaptive flexibility in microbial catabolism for structurally similar compounds.

  3. EDTA addition enhances bacterial respiration activities and hydrocarbon degradation in bioaugmented and non-bioaugmented oil-contaminated desert soils.

    Science.gov (United States)

    Al Kharusi, Samiha; Abed, Raeid M M; Dobretsov, Sergey

    2016-03-01

    The low number and activity of hydrocarbon-degrading bacteria and the low solubility and availability of hydrocarbons hamper bioremediation of oil-contaminated soils in arid deserts, thus bioremediation treatments that circumvent these limitations are required. We tested the effect of Ethylenediaminetetraacetic acid (EDTA) addition, at different concentrations (i.e. 0.1, 1 and 10 mM), on bacterial respiration and biodegradation of Arabian light oil in bioaugmented (i.e. with the addition of exogenous alkane-degrading consortium) and non-bioaugmented oil-contaminated desert soils. Post-treatment shifts in the soils' bacterial community structure were monitored using MiSeq sequencing. Bacterial respiration, indicated by the amount of evolved CO2, was highest at 10 mM EDTA in bioaugmented and non-bioaugmented soils, reaching an amount of 2.2 ± 0.08 and 1.6 ± 0.02 mg-CO2 g(-1) after 14 days of incubation, respectively. GC-MS revealed that 91.5% of the C14-C30 alkanes were degraded after 42 days when 10 mM EDTA and the bacterial consortium were added together. MiSeq sequencing showed that 78-91% of retrieved sequences in the original soil belonged to Deinococci, Alphaproteobacteria, Gammaproteobacteia and Bacilli. The same bacterial classes were detected in the 10 mM EDTA-treated soils, however with slight differences in their relative abundances. In the bioaugmented soils, only Alcanivorax sp. MH3 and Parvibaculum sp. MH21 from the exogenous bacterial consortium could survive until the end of the experiment. We conclude that the addition of EDTA at appropriate concentrations could facilitate biodegradation processes by increasing hydrocarbon availability to microbes. The addition of exogenous oil-degrading bacteria along with EDTA could serve as an ideal solution for the decontamination of oil-contaminated desert soils.

  4. Potential Environmental Factors Affecting Oil-Degrading Bacterial Populations in Deep and Surface Waters of the Northern Gulf of Mexico

    Science.gov (United States)

    Liu, Jiqing; Bacosa, Hernando P.; Liu, Zhanfei

    2017-01-01

    Understanding bacterial community dynamics as a result of an oil spill is important for predicting the fate of oil released to the environment and developing bioremediation strategies in the Gulf of Mexico. In this study, we aimed to elucidate the roles of temperature, water chemistry (nutrients), and initial bacterial community in selecting oil degraders through a series of incubation experiments. Surface (2 m) and bottom (1537 m) waters, collected near the Deepwater Horizon site, were amended with 200 ppm light Louisiana sweet crude oil and bacterial inoculums from surface or bottom water, and incubated at 4 or 24°C for 50 days. Bacterial community and residual oil were analyzed by pyrosequencing and gas chromatography-mass spectrometry (GC-MS), respectively. The results showed that temperature played a key role in selecting oil-degrading bacteria. Incubation at 4°C favored the development of Cycloclasticus, Pseudoalteromonas, Sulfitobacter, and Reinekea, while 24°C incubations enhanced Oleibacter, Thalassobius, Phaeobacter, and Roseobacter. Water chemistry and the initial community also had potential roles in the development of hydrocarbon-degrading bacterial communities. Pseudoalteromonas, Oleibacter, and Winogradskyella developed well in the nutrient-enriched bottom water, while Reinekea and Thalassobius were favored by low-nutrient surface water. We revealed that the combination of 4°C, crude oil and bottom inoculum was a key factor for the growth of Cycloclasticus, while the combination of surface inoculum and bottom water chemistry was important for the growth of Pseudoalteromonas. Moreover, regardless of the source of inoculum, bottom water at 24°C was a favorable condition for Oleibacter. Redundancy analysis further showed that temperature and initial community explained 57 and 19% of the variation observed, while oil and water chemistry contributed 14 and 10%, respectively. Overall, this study revealed the relative roles of temperature, water

  5. Evaluation of king oyster mushroom strains (Pleurotus eryngii) on selective lignin degradation in wheat straw: An update

    NARCIS (Netherlands)

    Sonnenberg, A.S.M.; Visser, M.H.M.; Lavrijssen, B.; Hendrickx, P.M.

    2016-01-01

    The collection of Plant Breeding contains a large number of strains of Pleurotus eryngii and Lentinula edodes, two fungi producing edible mushrooms and also known by their selective degradation of lignin in lignocellulosic materials.

  6. Fucoidan-degrading fungal strains: screening, morphometric evaluation, and influence of medium composition.

    Science.gov (United States)

    Rodríguez-Jasso, Rosa M; Mussatto, Solange Inês; Pastrana, Lorenzo; Aguilar, Cristóbal N; Teixeira, José A

    2010-12-01

    Ten different fungal strains from the genus Aspergillus, Penicillium, and Mucor were screened for fucoidan hydrolyzing ability aiming to find microorganisms able to produce sulfated fucan-degrading enzymes. Screening was carried out by measuring the strains kinetic and morphometric behavior over plate assays using Laminaria japonica fucoidan as only carbon source, testing three nitrogen sources (urea, peptone, and sodium nitrate). The selected fungal strains were subsequently used in submerged fermentations, which were performed for (1) selection of the strains able to growth over fucoidan medium and (2) media selection, testing the synergy of fucoidan with other sugars for inducing high enzyme titles. Radial expansion and hyphae parameters were observed for Aspergillus niger PSH, Mucor sp. 3P, and Penicillium purpurogenum GH2 grown only over fucoidan-urea medium. A. niger PSH showed the maximum enzymatic activity values, which were significantly different (p < 0.05) from those achieved by the other selected fungi. Sucrose addition to fucoidan media proportioned the highest fucoidanase activity values for this fungal strain. This research allowed establishing optimal conditions for metabolites synthesis by fungal stains able to act toward fucoidan ramified matrix.

  7. Draft Genome Sequence of Nocardioides luteus Strain BAFB, an Alkane-Degrading Bacterium Isolated from JP-7-Polluted Soil

    Science.gov (United States)

    Brown, Lisa M.; Gunasekera, Thusitha S.

    2017-01-01

    ABSTRACT Nocardioides luteus strain BAFB is a Gram-positive bacterium that efficiently degrades C8 to C11 alkanes aerobically. The draft genome of N. luteus BAFB is 5.76 Mb in size, with 5,358 coding sequences and 69.9% G+C content. The genes responsible for alkane degradation are present in this strain. PMID:28126947

  8. Complete Genome Sequence of Akkermansia glycaniphila Strain PytT, a Mucin-Degrading Specialist of the Reticulated Python Gut

    Science.gov (United States)

    Ouwerkerk, Janneke P.; Schaap, Peter J.; Ritari, Jarmo; Paulin, Lars; Belzer, Clara

    2017-01-01

    ABSTRACT Akkermansia glycaniphila is a novel Akkermansia species that was isolated from the intestine of the reticulated python and shares the capacity to degrade mucin with the human strain Akkermansia muciniphila MucT. Here, we report the complete genome sequence of strain PytT of 3,074,121 bp. The genomic analysis reveals genes for mucin degradation and aerobic respiration. PMID:28057747

  9. Isolation and characterization of a novel n-alkane-degrading strain, Acinetobacter haemolyticus AR-46

    Energy Technology Data Exchange (ETDEWEB)

    Bihari, Z.; Balazs, M.; Bartos, P.; Kesserue, P.; Kiss, I.; Mecs, I. [Bay Zoltan Foundation for Applied Research, Szeged (Hungary). Inst. for Biotechnology; Pettko-Szandtner, A. [Hungarian Academy of Sciences, Szeged (Hungary). Inst. of Plant Biology; Csanadi, G. [Szeged Univ. (Hungary). Dept. of Biotechnology

    2007-03-15

    Strain AR-46, isolated and identified as Acinetobacter haemolyticus, evolutionally distant from the known hydrocarbon-degrading Acinetobacter spp., proved to have excellent long-chain n-alkane-degrading ability. This is the first detailed report on an n-alkane-utilizing strain belonging to this species. The preferred substrate is n-hexadecane, with an optimal temperature of 37 C under aerobic conditions. Five complete and two partial open reading frames were sequenced and correlated with the early steps of monoterminal oxidation-initiated n-alkane mineralization. The encoded protein sequences and the arrangement of these genes displayed high similarity to those found in Acinetobacter sp. M-1, but AR-46 seemed to have only one alkane hydroxylase gene, with a completely different induction profile. Unique behaviour was also observed in n-alkane bioavailability. Substrate uptake occurred through the hydrophobic surface of n-alkane droplet-adhered cells possessing long, thick fimbriae, which were presumed to play a major role in n-alkane solubilization. A majority of the cells was in detached form, with thick, but short fimbriae. These free cells were permanently hydrophilic, unlike the cells of other Acinetobacter strains. (orig.)

  10. Immobilization of cells with nitrilase activity from a thermophilic bacterial strain.

    Science.gov (United States)

    Kabaivanova, L; Dobreva, E; Dimitrov, P; Emanuilova, E

    2005-01-01

    Cells of the moderately thermophilic Bacillus sp. UG-5B strain, producing nitrilase (EC3.5.5.1), which converts nitriles directly to the corresponding acid and ammonia, were immobilized using different types of matrices and techniques. A variety of sol-gel silica hybrids were tested for entrapment and adsorption of bacterial cells as well as chemical binding on polysulphone membranes. Activation of the matrix surface with formaldehyde led to an increase in immobilization efficiency and operational stability of the biocatalysts. Among the supports screened, membranes gave the best results for enzyme activity and especially operational stability, with retention of 100% activity after eight reaction cycles.

  11. Regeneration of nitric oxide chelate absorption solution by two heterotrophic bacterial strains

    Institute of Scientific and Technical Information of China (English)

    荆国华; 李伟; 施耀; 马碧瑶; 谭天恩

    2004-01-01

    Ferrous chelate absorption is deemed a promising method for NO removal from flue gas, but the key problem is the difficulty to regenerate the absorption solution, i.e. the complexes of FeⅡ(EDTA)NO and FeⅢ(EDTA) in the solution. Two bacterial strains isolated recently from the sludge of the denitrification step of a municipal wastewater treatment plant could be applied effectively to regenerate the absorbent were Pseudomonas sp. and klebsiella trevisan sp. Pseudomonas sp. exhibited high reduction ability on FeⅡ(EDTA)NO and the klebsiella trevisan sp. was more suitable for FeⅢ(EDTA) reduction.

  12. Science Letters:Regeneration of nitric oxide chelate absorption solution by two heterotrophic bacterial strains

    Institute of Scientific and Technical Information of China (English)

    荆国华; 李伟; 施耀; 马碧瑶; 谭天恩

    2004-01-01

    Ferrous chelate absorption is deemed a promising method for NO removal from flue gas, but the key problem is the difficulty to regenerate the absorption solution, i.e. the complexes of FeⅡ(EDTA)NO and FeⅢ(EDTA) in the solution.Two bacterial strains isolated recently from the sludge of the denitrification step of a municipal wastewater treatment plant could be applied effectively to regenerate the absorbent were Pseudomonas sp. and klebsiella trevisan sp. Pseudomonas sp.exhibited high reduction ability on FeⅡ(EDTA)NO and the klebsiella trevisan sp. was more suitable for FenⅢ(EDTA) reduction.

  13. Complete Genome Sequence of Gluconacetobacter hansenii Strain NQ5 (ATCC 53582), an Efficient Producer of Bacterial Cellulose.

    Science.gov (United States)

    Pfeffer, Sarah; Mehta, Kalpa; Brown, R Malcolm

    2016-08-11

    This study reports the release of the complete nucleotide sequence of Gluconacetobacter hansenii strain NQ5 (ATCC 53582). This strain was isolated by R. Malcolm Brown, Jr. in a sugar mill in North Queensland, Australia, and is an efficient producer of bacterial cellulose. The elucidation of the genome will contribute to the study of the molecular mechanisms necessary for cellulose biosynthesis.

  14. Inactivation rates of Cronobacter spp. and selected other bacterial strains in powdered infant formulae stored at different temperatures

    NARCIS (Netherlands)

    Kandhai, M.C.; Reij, M.W.; Schothorst, van M.; Gorris, L.G.M.; Zwietering, M.H.

    2010-01-01

    The aim of this study was to determine the survival of two strains of Cronobacter (Enterobacter sakazakii) and six other bacterial strains inoculated into dry powdered infant formula (PIF) stored for 22 weeks at several temperatures between 7 and 42°C. The experimental setup involved a relatively hi

  15. Degradation of Benzo [a] Pyrene by a novel strain Bacillus subtilis BMT4i (MTCC 9447

    Directory of Open Access Journals (Sweden)

    Madhuri Kaushish Lily

    2009-12-01

    Full Text Available Benzo [a] Pyrene (BaP is a highly recalcitrant, polycyclic aromatic hydrocarbon (PAH with high genotoxicity and carcinogenicity. It is formed and released into the environment due to incomplete combustion of fossil fuel and various anthropogenic activities including cigarette smoke and automobile exhausts. The aim of present study is to isolate bacteria which can degrade BaP as a sole source of carbon and energy. We have isolated a novel strain BMT4i (MTCC 9447 of Bacillus subtilis from automobile contaminated soil using BaP (50 μg /ml as the sole source of carbon and energy in basal salt mineral (BSM medium. The growth kinetics of BMT4i was studied using CFU method which revealed that BMT4i is able to survive in BaP-BSM medium up to 40 days attaining its peak growth (10(29 fold increase in cell number on 7 days of incubation. The BaP degradation kinetics of BMT4i was studied using High Performance Liquid Chromatography (HPLC analysis of BaP biodegradation products. BMT4i started degrading BaP after 24 hours and continued up to 28 days achieving maximum degradation of approximately 84.66 %. The above findings inferred that BMT4i is a very efficient degrader of BaP. To our best of knowledge, this is the first report showing utilization of BaP as a sole source of carbon and energy by bacteria. In addition, BMT4i can degrade a wide range of PAHs including naphthalene, anthracene, and dibenzothiophene therefore, it could serve as a better candidate for bioremediation of PAHs contaminated sites.

  16. Isolation and characterization of a novel native Bacillus thuringiensis strain BRC-HZM2 capable of degrading chlorpyrifos.

    Science.gov (United States)

    Wu, Songqing; Peng, Yan; Huang, Zhangmin; Huang, Zhipeng; Xu, Lei; Ivan, Gelbič; Guan, Xiong; Zhang, Lingling; Zou, Shuangquan

    2015-03-01

    Studies were carried out to isolate chlorpyrifos degrading Bacillus thuringiensis (Bt) strains from chlorpyrifos-contaminated samples. Six Bt strains (isolation rate 2.7%) were isolated by modified sodium acetate antibiotic heat treatment, and one novel strain (BRC-HZM2) was selected for further analysis. Phenotype and phylogeny analysis of this strain was conducted on the basis of biochemical reactions, antibiotic sensitivity, 16s rRNA genes, plasmid profile, insecticidal crystal protein profiles, and PCR-RFLP for cry and cyt genes. The degradation rate of chlorpyrifos in liquid culture was estimated during 48 h of incubation for the isolate BRC-HZM2. More than 50% of the initial chlorpyrifos concentration degraded within 12 h, 88.9% after 48 h. These results highlight the potential of the Bt strain for biological control and the bioremediation of environments contaminated with chlorpyrifos.

  17. Isolation and screening of strains producing high amounts of rutin degrading enzymes from Fagopyrum tataricum seeds.

    Science.gov (United States)

    Zheng, Ya-Di; Luo, Qing-Lin; Zhou, Mei-Liang; Wang, De-Zhou; Zhang, Ye-Dong; Shao, Ji-Rong; Zhu, Xue-Mei; Tang, Yu

    2013-02-01

    The rutin degrading enzyme (RDE) was isolated and purified from tartary buckwheat seeds. The RDE was purified about 11.34-fold and its final yield was 3.5%, which was very low, due to our purification strategy of giving priority to purity over yield. The RDE molecular weight was estimated to be about 60 kDa. When rutin was used as substrate, an optimal enzyme activity was seen at around pH 5.0 and 40 °C. Strains isolation strategy characterized by the use of rutin as sole carbon source in enrichment cultures was used to isolate RDE-producing strains. Then the active strains were identified by morphology characterization and 18s rDNA-ITS (Internal Transcribed Spacer) gene sequencing. Three isolates coded as B3, W2, Y2 were successfully isolated from fusty Fagopyrum tataricum flour cultures. Strain B3 possessed the highest unit activity among these three strains, and its total activity reached up to 171.0 Unit. The active isolate (B3) could be assigned to Penicillium farinosum. When the Penicillium farinosum strains were added to tartary buckwheat flour cultures at pH 5.0, 30 °C after 5 days fermentation, the quercetin production raised up to 1.78 mg/l, almost 5.1 times higher than the fermentation without the above active strains. Hence, a new approach was available to utilize microorganism-aided fermentation for effective quercetin extraction from Fagopyrum tataricum seeds. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Identification and discrimination of bacterial strains by laser induced breakdown spectroscopy and neural networks.

    Science.gov (United States)

    Marcos-Martinez, D; Ayala, J A; Izquierdo-Hornillos, R C; de Villena, F J Manuel; Caceres, J O

    2011-05-15

    A method based on laser induced breakdown spectroscopy (LIBS) and neural networks (NNs) has been developed and applied to the identification and discrimination of specific bacteria strains (Pseudomonas aeroginosa, Escherichia coli and Salmonella typhimurium). Instant identification of the samples is achieved using a spectral library, which was obtained by analysis using a single laser pulse of representative samples and treatment by neural networks. The samples used in this study were divided into three groups, which were prepared on three different days. The results obtained allow the identification of the bacteria tested with a certainty of over 95%, and show that only a difference between the bacteria can cause identification. Single-shot measurements were sufficient for clear identification of the bacterial strains studied. The method can be developed for automatic real time, fast, reliable and robust measurements and can be packaged in portable systems for non-specialist users. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Bacterial inoculants of forage grasses that enhance degradation of 2-chlorobenzoic acid in soil

    Energy Technology Data Exchange (ETDEWEB)

    Siciliano, S.D.; Germida, J.J. [Univ. of Saskatchewan, Saskatoon, Saskatchewan (Canada)

    1997-06-01

    Biological remediation of contaminated soil is an effective method of reducing risk to human and ecosystem health. Bacteria and plants might be used to enhance remediation of soil pollutants in situ. This study assessed the potential of bacteria, plants, and plant-bacteria associations to remediate 2-chlorobenzoic acid (2CBA) contaminated soil. Initially, grass viability was assessed in 2CBA-contaminated soil. Soil was contaminated with 2CBA, forage grasses were grown under growth chamber conditions for 42 or 60 d, and the 2CBA concentration in soil was determined by gas chromatography. Only five of 16 forage grasses grew in 2CBA-treated soil. Growth of Bromus inermis had no effect on 2CBA concentration, whereas Agropyron intermedium, B. biebersteinii, A. riparum, and Elymus dauricus decreased 2CBA relative to nonplanted control soil by 32 to 42%. The 12 bacteria isolates were screened for their ability to promote the germination of the five grasses in 2CBA-contaminated soil. Inoculation of A. riparum with Pseudomonas aeruginosa strain R75, a proven plant growth-promoting rhizobacterium, increased seed germination by 80% and disappearance of 2CBA by 20% relative to noninoculated plants. Inoculation of E. dauricus with a mixture of P. savastanoi strain CB35, a 2CBA-degrading bacterium, and P. aeruginosa strain R75 increased disappearance of 2CBA by 112% relative to noninoculated plants. No clear relationship between enhanced 2CBA disappearance and increased plant biomass was found. These results suggest that specific plant-microbial systems can be developed to enhance remediation of pollutants in soil.

  20. Diverse Bacterial Groups Contribute to the Alkane Degradation Potential of Chronically Polluted Subantarctic Coastal Sediments

    Energy Technology Data Exchange (ETDEWEB)

    Guibert, Lilian M.; Loviso, Claudia L.; Borglin, Sharon; Jansson, Janet K.; Dionisi, Hebe M.; Lozada, Mariana

    2015-11-07

    We aimed to gain insight into the alkane degradation potential of microbial communities from chronically polluted sediments of a subantarctic coastal environment using a combination of metagenomic approaches. A total of 6178 sequences annotated as alkane-1-monooxygenases (EC 1.14.15.3) were retrieved from a shotgun metagenomic dataset that included two sites analyzed in triplicate. The majority of the sequences binned with AlkB described in Bacteroidetes (32 ± 13 %) or Proteobacteria (29 ± 7 %), although a large proportion remained unclassified at the phylum level. Operational taxonomic unit (OTU)-based analyses showed small differences in AlkB distribution among samples that could be correlated with alkane concentrations, as well as with site-specific variations in pH and salinity. A number of low-abundance OTUs, mostly affiliated with Actinobacterial sequences, were found to be only present in the most contaminated samples. On the other hand, the molecular screening of a large-insert metagenomic library of intertidal sediments from one of the sampling sites identified two genomic fragments containing novel alkB gene sequences, as well as various contiguous genes related to lipid metabolism. Both genomic fragments were affiliated with the phylum Planctomycetes, and one could be further assigned to the genus Rhodopirellula due to the presence of a partial sequence of the 23S ribosomal RNA (rRNA) gene. This work highlights the diversity of bacterial groups contributing to the alkane degradation potential and reveals patterns of functional diversity in relation with environmental stressors in a chronically polluted, high-latitude coastal environment. In addition, alkane biodegradation genes are described for the first time in members of Planctomycetes.

  1. Diverse Bacterial Groups Contribute to the Alkane Degradation Potential of Chronically Polluted Subantarctic Coastal Sediments.

    Science.gov (United States)

    Guibert, Lilian M; Loviso, Claudia L; Borglin, Sharon; Jansson, Janet K; Dionisi, Hebe M; Lozada, Mariana

    2016-01-01

    We aimed to gain insight into the alkane degradation potential of microbial communities from chronically polluted sediments of a subantarctic coastal environment using a combination of metagenomic approaches. A total of 6178 sequences annotated as alkane-1-monooxygenases (EC 1.14.15.3) were retrieved from a shotgun metagenomic dataset that included two sites analyzed in triplicate. The majority of the sequences binned with AlkB described in Bacteroidetes (32 ± 13 %) or Proteobacteria (29 ± 7 %), although a large proportion remained unclassified at the phylum level. Operational taxonomic unit (OTU)-based analyses showed small differences in AlkB distribution among samples that could be correlated with alkane concentrations, as well as with site-specific variations in pH and salinity. A number of low-abundance OTUs, mostly affiliated with Actinobacterial sequences, were found to be only present in the most contaminated samples. On the other hand, the molecular screening of a large-insert metagenomic library of intertidal sediments from one of the sampling sites identified two genomic fragments containing novel alkB gene sequences, as well as various contiguous genes related to lipid metabolism. Both genomic fragments were affiliated with the phylum Planctomycetes, and one could be further assigned to the genus Rhodopirellula due to the presence of a partial sequence of the 23S ribosomal RNA (rRNA) gene. This work highlights the diversity of bacterial groups contributing to the alkane degradation potential and reveals patterns of functional diversity in relation with environmental stressors in a chronically polluted, high-latitude coastal environment. In addition, alkane biodegradation genes are described for the first time in members of Planctomycetes.

  2. Bacterial and fungal communities in a degraded ombrotrophic peatland undergoing natural and managed re-vegetation.

    Directory of Open Access Journals (Sweden)

    David R Elliott

    Full Text Available The UK hosts 15-19% of global upland ombrotrophic (rain fed peatlands that are estimated to store 3.2 billion tonnes of carbon and represent a critical upland habitat with regard to biodiversity and ecosystem services provision. Net production is dependent on an imbalance between growth of peat-forming Sphagnum mosses and microbial decomposition by microorganisms that are limited by cold, acidic, and anaerobic conditions. In the Southern Pennines, land-use change, drainage, and over 200 years of anthropogenic N and heavy metal deposition have contributed to severe peatland degradation manifested as a loss of vegetation leaving bare peat susceptible to erosion and deep gullying. A restoration programme designed to regain peat hydrology, stability and functionality has involved re-vegetation through nurse grass, dwarf shrub and Sphagnum re-introduction. Our aim was to characterise bacterial and fungal communities, via high-throughput rRNA gene sequencing, in the surface acrotelm/mesotelm of degraded bare peat, long-term stable vegetated peat, and natural and managed restorations. Compared to long-term vegetated areas the bare peat microbiome had significantly higher levels of oligotrophic marker phyla (Acidobacteria, Verrucomicrobia, TM6 and lower Bacteroidetes and Actinobacteria, together with much higher ligninolytic Basidiomycota. Fewer distinct microbial sequences and significantly fewer cultivable microbes were detected in bare peat compared to other areas. Microbial community structure was linked to restoration activity and correlated with soil edaphic variables (e.g. moisture and heavy metals. Although rapid community changes were evident following restoration activity, restored bare peat did not approach a similar microbial community structure to non-eroded areas even after 25 years, which may be related to the stabilisation of historic deposited heavy metals pollution in long-term stable areas. These primary findings are discussed in

  3. Establishment of Bacterial Herbicide Degraders in a Rapid Sand Filter for Bioremediation of Phenoxypropionate-Polluted Groundwater.

    Science.gov (United States)

    Feld, Louise; Nielsen, Tue Kjærgaard; Hansen, Lars Hestbjerg; Aamand, Jens; Albers, Christian Nyrop

    2015-11-20

    In this study, we investigated the establishment of natural bacterial degraders in a sand filter treating groundwater contaminated with the phenoxypropionate herbicides (RS)-2-(4-chloro-2-methylphenoxy)propanoic acid (MCPP) and (RS)-2-(2,4-dichlorophenoxy)propanoic acid (DCPP) and the associated impurity/catabolite 4-chlorophenoxypropanoic acid (4-CPP). A pilot facility was set up in a contaminated landfill site. Anaerobic groundwater was pumped up and passed through an aeration basin and subsequently through a rapid sand filter, which is characterized by a short residence time of the water in the filter. For 3 months, the degradation of DCPP, MCPP, and 4-CPP in the sand filter increased to 15 to 30% of the inlet concentration. A significant selection for natural bacterial herbicide degraders also occurred in the sand filter. Using a most-probable-number (MPN) method, we found a steady increase in the number of culturable phenoxypropionate degraders, reaching approximately 5 × 10(5) degraders per g sand by the end of the study. Using a quantitative PCR targeting the two phenoxypropionate degradation genes, rdpA and sdpA, encoding stereospecific dioxygenases, a parallel increase was observed, but with the gene copy numbers being about 2 to 3 log units higher than the MPN. In general, the sdpA gene was more abundant than the rdpA gene, and the establishment of a significant population of bacteria harboring sdpA occurred faster than the establishment of an rdpA gene-carrying population. The identities of the specific herbicide degraders in the sand filter were assessed by Illumina MiSeq sequencing of 16S rRNA genes from sand filter samples and from selected MPN plate wells. We propose a list of potential degrader bacteria involved in herbicide degradation, including representatives belonging to the Comamonadaceae and Sphingomonadales.

  4. Draft Genome Sequence of Oil-Degrading Bacterium Gallaecimonas pentaromativorans Strain YA_1 from the Southwest Indian Ocean

    Science.gov (United States)

    Xu, Yiyuan; Ren, Chong; Chen, Ruixuan

    2016-01-01

    Gallaecimonas pentaromativorans has been previously reported to be capable of degrading crude oil and diesel oil. G. pentaromativorans strain YA_1 was isolated from the southwest Indian Ocean and can degrade crude oil. This study reports the draft genome sequence of G. pentaromativorans, which can provide insights into the mechanisms of microbial oil biodegradation. PMID:27491993

  5. Draft Genome Sequence of Oil-Degrading Bacterium Gallaecimonas pentaromativorans Strain YA_1 from the Southwest Indian Ocean.

    Science.gov (United States)

    Xu, Yiyuan; Ren, Chong; Chen, Ruixuan; Zeng, Runying

    2016-08-04

    Gallaecimonas pentaromativorans has been previously reported to be capable of degrading crude oil and diesel oil. G. pentaromativorans strain YA_1 was isolated from the southwest Indian Ocean and can degrade crude oil. This study reports the draft genome sequence of G. pentaromativorans, which can provide insights into the mechanisms of microbial oil biodegradation.

  6. Complete genome sequence of Streptomyces sp. strain CFMR 7, a natural rubber degrading actinomycete isolated from Penang, Malaysia.

    Science.gov (United States)

    Nanthini, Jayaram; Chia, Kim-Hou; Thottathil, Gincy P; Taylor, Todd D; Kondo, Shinji; Najimudin, Nazalan; Baybayan, Primo; Singh, Siddharth; Sudesh, Kumar

    2015-11-20

    Streptomyces sp. strain CFMR 7, which naturally degrades rubber, was isolated from a rubber plantation. Whole genome sequencing and assembly resulted in 2 contigs with total genome size of 8.248 Mb. Two latex clearing protein (lcp) genes which are responsible for rubber degrading activities were identified.

  7. Genome Sequence of a Typical Ultramicrobacterium, Curvibacter sp. Strain PAE-UM, Capable of Phthalate Ester Degradation.

    Science.gov (United States)

    Ma, Dan; Hao, Zhenyu; Sun, Rui; Bartlam, Mark; Wang, Yingying

    2016-01-14

    Curvibacter sp. strain PAE-UM, isolated from river sediment, is a typical ultramicrobacterium capable of phthalate ester degradation. The genome of Curvibacter sp. PAE-UM consists of 3,284,473 bp, and its information will provide insights into the molecular mechanisms underlying its degradation ability.

  8. Genome Sequence of a Typical Ultramicrobacterium, Curvibacter sp. Strain PAE-UM, Capable of Phthalate Ester Degradation

    OpenAIRE

    Ma, Dan; Hao, Zhenyu; Sun, Rui; Bartlam, Mark; Wang, Yingying

    2016-01-01

    Curvibacter sp. strain PAE-UM, isolated from river sediment, is a typical ultramicrobacterium capable of phthalate ester degradation. The genome of Curvibacter sp. PAE-UM consists of 3,284,473 bp, and its information will provide insights into the molecular mechanisms underlying its degradation ability.

  9. Modular microfluidic system fabricated in thermoplastics for the strain-specific detection of bacterial pathogens.

    Science.gov (United States)

    Chen, Yi-Wen; Wang, Hong; Hupert, Mateusz; Witek, Makgorzata; Dharmasiri, Udara; Pingle, Maneesh R; Barany, Francis; Soper, Steven A

    2012-09-21

    The recent outbreaks of a lethal E. coli strain in Germany have aroused renewed interest in developing rapid, specific and accurate systems for detecting and characterizing bacterial pathogens in suspected contaminated food and/or water supplies. To address this need, we have designed, fabricated and tested an integrated modular-based microfluidic system and the accompanying assay for the strain-specific identification of bacterial pathogens. The system can carry out the entire molecular processing pipeline in a single disposable fluidic cartridge and detect single nucleotide variations in selected genes to allow for the identification of the bacterial species, even its strain with high specificity. The unique aspect of this fluidic cartridge is its modular format with task-specific modules interconnected to a fluidic motherboard to permit the selection of the target material. In addition, to minimize the amount of finishing steps for assembling the fluidic cartridge, many of the functional components were produced during the polymer molding step used to create the fluidic network. The operation of the cartridge was provided by electronic, mechanical, optical and hydraulic controls located off-chip and packaged into a small footprint instrument (1 ft(3)). The fluidic cartridge was capable of performing cell enrichment, cell lysis, solid-phase extraction (SPE) of genomic DNA, continuous flow (CF) PCR, CF ligase detection reaction (LDR) and universal DNA array readout. The cartridge was comprised of modules situated on a fluidic motherboard; the motherboard was made from polycarbonate, PC, and used for cell lysis, SPE, CF PCR and CF LDR. The modules were task-specific units and performed universal zip-code array readout or affinity enrichment of the target cells with both made from poly(methylmethacrylate), PMMA. Two genes, uidA and sipB/C, were used to discriminate between E. coli and Salmonella, and evaluated as a model system. Results showed that the fluidic

  10. Modular microfluidic system fabricated in thermoplastics for the strain-specific detection of bacterial pathogens†

    Science.gov (United States)

    Chen, Yi-Wen; Wang, Hong; Hupert, Mateusz; Witek, Makgorzata; Dharmasiri, Udara; Pingle, Maneesh R.; Barany, Francis

    2015-01-01

    The recent outbreaks of a lethal E. coli strain in Germany have aroused renewed interest in developing rapid, specific and accurate systems for detecting and characterizing bacterial pathogens in suspected contaminated food and/or water supplies. To address this need, we have designed, fabricated and tested an integrated modular-based microfluidic system and the accompanying assay for the strain-specific identification of bacterial pathogens. The system can carry out the entire molecular processing pipeline in a single disposable fluidic cartridge and detect single nucleotide variations in selected genes to allow for the identification of the bacterial species, even its strain with high specificity. The unique aspect of this fluidic cartridge is its modular format with task-specific modules interconnected to a fluidic motherboard to permit the selection of the target material. In addition, to minimize the amount of finishing steps for assembling the fluidic cartridge, many of the functional components were produced during the polymer molding step used to create the fluidic network. The operation of the cartridge was provided by electronic, mechanical, optical and hydraulic controls located off-chip and packaged into a small footprint instrument (1 ft3). The fluidic cartridge was capable of performing cell enrichment, cell lysis, solid-phase extraction (SPE) of genomic DNA, continuous flow (CF) PCR, CF ligase detection reaction (LDR) and universal DNA array readout. The cartridge was comprised of modules situated on a fluidic motherboard; the motherboard was made from polycarbonate, PC, and used for cell lysis, SPE, CF PCR and CF LDR. The modules were task-specific units and performed universal zip-code array readout or affinity enrichment of the target cells with both made from poly(methylmethacrylate), PMMA. Two genes, uidA and sipB/C, were used to discriminate between E. coli and Salmonella, and evaluated as a model system. Results showed that the fluidic system

  11. Degradation of 2,4-dichlorophenoxyacetic acid by a halotolerant strain of Penicillium chrysogenum: antibiotic production.

    Science.gov (United States)

    Ferreira-Guedes, Sumaya; Mendes, Benilde; Leitão, Ana Lúcia

    2012-01-01

    The extensive use of pesticides in agriculture has prompted intensive research on chemical and biological methods in order to protect contamination of water and soil resources. In this paper the degradation of the pesticide 2,4-dichlorophenoxyacetic acid by a Penicillium chrysogenum strain previously isolated from a salt mine was studied in batch cultures. Co-degradation of 2,4-dichlorophenoxyacetic acid with additives such as sugar and intermediates of pesticide metabolism was also investigated. Penicillium chrysogenum in solid medium was able to grow at concentrations up to 1000 mg/L of 2,4-dichlorophenoxyacetic acid (2,4-D) with sucrose. Meanwhile, supplementation of the solid medium with glucose and lactose led to fungal growth at concentrations up to 500 mg/L of herbicide. Batch cultures of 2,4-D at 100 mg/L were developed under aerobic conditions with the addition of glucose, lactose and sucrose, showing sucrose as the best additional carbon source. The 2,4-D removal was quantified by liquid chromatography. The fungus was able to use 2,4-D as the sole carbon and energy source under 0%, 2% and 5.9% NaCl. The greatest 2,4-D degradation efficiency was found using alpha-ketoglutarate and ascorbic acid as co-substrates under 2% NaCl at pH 7. Penicillin production was evaluated in submerged cultures by bioassay, and higher amounts of beta-lactam antibiotic were produced when the herbicide was alone. Taking into account the ability of P. chrysogenum CLONA2 to degrade aromatic compounds, this strain could be an interesting tool for 2,4-D herbicide remediation in saline environments.

  12. Selective growth promotion of bloom-forming raphidophyte Heterosigma akashiwo by a marine bacterial strain.

    Science.gov (United States)

    Higashi, Aiko; Fujitani, Yoshiko; Nakayama, Natsuko; Tani, Akio; Ueki, Shoko

    2016-12-01

    Algal bloom is typically caused by aberrant propagation of a single species, resulting in its predomination in the local population. While environmental factors including temperature and eutrophication are linked to bloom, the precise mechanism of its formation process is still obscure. Here, we isolated a bacterial strain that promotes growth of Heterosigma akashiwo, a Raphidophyceae that causes harmful algal blooms. Based on 16S rRNA gene sequence, the strain was identified as Altererythrobacter ishigakiensis, a member of the class Alphaproteobacteria. When added to culture, this strain facilitated growth of H. akashiwo and increased its cell culture yield significantly. Importantly, this strain did not affect the growth of other raphidophytes, Chattonella ovate and C. antiqua, indicating that it promotes growth of H. akashiwo in a species-specific manner. We also found that, in co-culture, H. akashiwo suppressed the growth of C. ovate. When A. ishigakiensis was added to the mixed culture, H. akashiwo growth was facilitated while C. ovate propagation was markedly suppressed, indicating that the presence of the bacterium enhances the dominance of H. akashiwo over C. ovate. This is the first example of selective growth promotion of H. akashiwo by a marine bacterium, and may exemplify importance of symbiotic bacterium on algal bloom forming process in general.

  13. Preparation and properties of bacteriophage-borne enzyme degrading bacterial exopolysaccharide

    Institute of Scientific and Technical Information of China (English)

    Mou Haijin; Wang Jingxue; Jiang Xiaolu; Liu Zhihong

    2008-01-01

    Bacteriophages infected different serotypes of Klebsiella were isolated from sewage. Among them, a heat-stable polysaccharide depolymerase enzyme which could degrade bacterial exopolysaccharide effectively was prepared from the phage infecting Klebsiella K13. Treatment at 60 ℃ for 30 min could inactivate most of the K13 phage, with the titration decreasing from 6.4×108 PFU/mL to 1.6×106 PFU/mL. However, no obvious loss of phage enzyme activity was found after this treatment. The optimum hydrolytic temperature of phage enzyme was 60 ℃, with an activity 57% higher than that at 30 ℃. The addition of phage enzyme could result in a rapid decrease of viscosity of exopolysaccharide (EPS) solution within minutes, indicating that K13 phage polysaccharide depolymerase acts as a kind of endo-glycanohydrolase. HPLC and reducing sugar analysis showed that the hydrolysis of EPS approached approximately the maximum at 4h when the final concentration of phage was 6.0 × 108 PFU/mL. The results showed that Klebsiella K13 phage depolymerase enzyme could be used as a good tool for the preparation of EPS oligosaccharide.

  14. Draft Genome Perspective of Staphylococcus saprophyticus Strain SU8, an N-Acyl Homoserine Lactone-Degrading Bacterium.

    Science.gov (United States)

    Chan, Kok-Gan; Sulaiman, Joanita; Yong, Delicia Ann; Tee, Kok Keng; Yin, Wai-Fong; Priya, Kumutha

    2015-09-24

    Staphylococcus saprophyticus strain SU8 was isolated from a pristine water source in Malaysia and it exhibited degradation of N-hexanoylhomoserine lactone. Here we report the draft genome sequence of S. saprophyticus strain SU8 to further understand its quorum quenching abilities.

  15. Biodegradation of the metallic carcinogen hexavalent chromium Cr(VI by an indigenously isolated bacterial strain

    Directory of Open Access Journals (Sweden)

    Das Alok

    2010-01-01

    Full Text Available Background : Hexavalent chromium [Cr(VI], a potential mutagen and carcinogen, is regularly introduced into the environment through diverse anthropogenic activities, including electroplating, leather tanning, and pigment manufacturing. Human exposure to this toxic metal ion not only causes potential human health hazards but also affects other life forms. The World Health Organization, the International Agency for Research on Cancer, and the Environmental Protection Agency have determined that Cr(VI compounds are known human carcinogens. The Sukinda valley in Jajpur District, Orissa, is known for its deposit of chromite ore, producing nearly 98% of the chromite ore in India and one of the prime open cast chromite ore mines in the world (CES, Orissa Newsletter. Materials and Methods: Our investigation involved microbial remediation of Cr(VI without producing any byproduct. Bacterial cultures tolerating high concentrations of Cr were isolated from the soil sample collected from the chromite-contaminated sites of Sukinda, and their bioaccumulation properties were investigated. Strains capable of growing at 250 mg/L Cr(VI were considered as Cr resistant. Results: The experimental investigation showed the maximum specific Cr uptake at pH 7 and temperature 30oC. At about 50 mg/L initial Cr(VI concentrations, uptake of the selected potential strain exceeded 98% within 12 h of incubation. The bacterial isolate was identified by 16S rRNA sequencing as Brevebacterium casei. Conclusion: Results indicated promising approach for microbial remediation of effluents containing elevated levels of Cr(VI.

  16. Bacterial virulence, proinflammatory cytokines and host immunity: how to choose the appropriate Salmonella vaccine strain?

    Science.gov (United States)

    Raupach, B; Kaufmann, S H

    2001-01-01

    Salmonella infection in its mammalian host can be dissected into two main components. The co-ordinate expression of bacterial virulence genes which are designed to evade, subvert or circumvent the host response on the one hand, and the host defence mechanisms which are designed to restrict bacterial survival and replication on the other hand. The outcome of infection is determined by the one which succeeds in disturbing this equilibrium more efficiently. This delicate balance between Salmonella virulence and host immunity/inflammation has important implications for vaccine development or therapeutic intervention. Novel Salmonella vaccine candidates and live carriers for heterologous antigens are attenuated strains with defined genetic modifications of metabolic or virulence functions. Although genetic defects of different gene loci can lead to similar degrees of attenuation, effects on the course of infection may vary, thereby altering the quality of the elicited immune response. Studies with gene-deficient animals indicate that Salmonella typhimurium strains with mutations in aroA, phoP/phoQ or ssrA/ssrB invoke different immune responses and that a differential repertoire of pro-inflammatory cytokines is required for clearance. Consequently, Salmonella mutants defective in distinct virulence functions offer the potential to specifically modulate the immune response for defined medical applications.

  17. Partial Characteristics of Hydrogen Production by Fermentative Hydrogen-producing Bacterial Strain B49

    Institute of Scientific and Technical Information of China (English)

    Wang Xiangjing(王相晶); Ren Nanqi; Xiang Wensheng; Lin Ming; Guo Wanqian

    2003-01-01

    To investigate the characteristics of hydrogen production by a novel fermentative hydrogen-producing bacterial strain B49 (AF481148 in EMBL), batch experiments are conducted under different conditions. Hydrogen production has a correlation with cell growth and the consumption of glucose and soluble protein. The optimum pH for cell growth is 4.5±0.15. At acidic pH 4.0±0.15, the bacteria has the maximum accumulated hydrogen volume of 2382 ml/L culture and the maximum hydrogen evolution rate of 339.9 ml/L culture*h with 1% glucose. The optimum temperature for cell growth and hydrogen production is 35℃. In addition, fermentative hydrogen-producing bacterial strain B49 can generate hydrogen from the decomposition of other organic substrates such as wheat, soybean, corn, and potato. Moreover, it can also produce hydrogen from molasses wastewater and brewage wastewater, and hydrogen yields are 137.9 ml H2/g COD and 49.9 ml H2/g COD, respectively.

  18. Cell wall degrading isoenzyme profiles of Trichoderma biocontrol strains show correlation with rDNA species

    Institute of Scientific and Technical Information of China (English)

    Sanz L; Hermosa M R; González F J; Monte E

    2004-01-01

    @@ Species of the fungus Trichoderma, a genus of Hyphomycetes, are ubiquitous in the environment, but especially in soil. They have been used in a wide range of commercial applications including the production of hydrolases and in the biological control of plant diseases. A fundamental part of the Trichoderma antifungal system consists of a series of genes coding for a surprising variety of extracellular cell wall degrading enzymes (CWDE).Characterisation and identification of strains at the species level is the first step in utilizing the full potential of fungi in specific applications. One aim when isolating Trichoderma strains is to identify those which can be used in new agricultural and industrial applications. In the past it was not uncommon that biocontrol strains were defined as T. harzianum Rifai, due to the limited classification system of the genus Trichoderma. In recent years, several PCR-based molecular techniques have been used to detect and discriminate among microorganisms. Sequence analysis of the ITS regions of the ribosomal DNA and gene fragments as those corresponding to tef1 gene have been helpful in the neotypification, description and characterization of species in the genus Trichoderna.Another useful method for the identification of Trichoderma strains is the randomly amplified polymorphic DNA (RAPD) technique.Isozyme polymorphisms evaluation of five putative extracellular lytic enzymes loci (β-1,3-glucanase, β-1,6-glucanase, cellulase, chitinase and protease antivities) were carried out using representative strains of defined molecular groups. CWDE groupings obtained from biocontrol strains are discussed in relation to their phylogenetic location and antifungal activities.Compiling morphological, biochemical and sequence information data into a common database would provide a useful resource that could be used to accurately name new haplotypes identified in the future and correctly place them within the genus Trichoderma.

  19. Effect of Sphingobium yanoikuyae B1 inoculation on bacterial community dynamics and polycyclic aromatic hydrocarbon degradation in aged and freshly PAH-contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Cunliffe, Michael [Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester M13 9PT (United Kingdom); Kertesz, Michael A. [Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester M13 9PT (United Kingdom)]. E-mail: michael.kertesz@manchester.ac.uk

    2006-11-15

    Sphingobium yanoikuyae B1 is able to degrade a range of polycyclic aromatic hydrocarbons (PAHs) and as a sphingomonad belongs to one of the dominant genera found in PAH-contaminated soils. We examined the ecological effect that soil inoculation with S. yanoikuyae B1 has on the native bacterial community in three different soils: aged PAH-contaminated soil from an industrial site, compost freshly contaminated with PAHs and un-contaminated compost. Survival of S. yanoikuyae B1 was dependent on the presence of PAHs, and the strain was unable to colonize un-contaminated compost. Inoculation with S. yanoikuyae B1 did not cause extensive changes in the native bacterial community of either soil, as assessed by denaturing gel electrophoresis, but its presence led to an increase in the population level of two other species in the aged contaminated soil community and appeared to have an antagonistic affect on several members of the contaminated compost community, indicating niche competition. - Sphingobium yanoikuyae B1 does not cause major changes in the native bacterial community while colonizing PAH-contaminated soils, but some niche competition is evident.

  20. Biodegradation Ability and Catabolic Genes of Petroleum-Degrading Sphingomonas koreensis Strain ASU-06 Isolated from Egyptian Oily Soil

    Directory of Open Access Journals (Sweden)

    Abd El-Latif Hesham

    2014-01-01

    Full Text Available Polycyclic aromatic hydrocarbons (PAHs are serious pollutants and health hazards. In this study, 15 PAHs-degrading bacteria were isolated from Egyptian oily soil. Among them, one Gram-negative strain (ASU-06 was selected and biodegradation ability and initial catabolic genes of petroleum compounds were investigated. Comparison of 16S rRNA gene sequence of strain ASU-06 to published sequences in GenBank database as well as phylogenetic analysis identified ASU-06 as Sphingomonas koreensis. Strain ASU-06 degraded 100, 99, 98, and 92.7% of 100 mg/L naphthalene, phenanthrene, anthracene, and pyrene within 15 days, respectively. When these PAHs present in a mixed form, the enhancement phenomenon appeared, particularly in the degradation of pyrene, whereas the degradation rate was 98.6% within the period. This is the first report showing the degradation of different PAHs by this species. PCR experiments with specific primers for catabolic genes alkB, alkB1, nahAc, C12O, and C23O suggested that ASU-06 might possess genes for aliphatic and PAHs degradation, while PAH-RHDαGP gene was not detected. Production of biosurfactants and increasing cell-surface hydrophobicity were investigated. GC/MS analysis of intermediate metabolites of studied PAHs concluded that this strain utilized these compounds via two main pathways, and phthalate was the major constant product that appeared in each day of the degradation period.

  1. Biodegradation ability and catabolic genes of petroleum-degrading Sphingomonas koreensis strain ASU-06 isolated from Egyptian oily soil.

    Science.gov (United States)

    Hesham, Abd El-Latif; Mawad, Asmaa M M; Mostafa, Yasser M; Shoreit, Ahmed

    2014-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are serious pollutants and health hazards. In this study, 15 PAHs-degrading bacteria were isolated from Egyptian oily soil. Among them, one Gram-negative strain (ASU-06) was selected and biodegradation ability and initial catabolic genes of petroleum compounds were investigated. Comparison of 16S rRNA gene sequence of strain ASU-06 to published sequences in GenBank database as well as phylogenetic analysis identified ASU-06 as Sphingomonas koreensis. Strain ASU-06 degraded 100, 99, 98, and 92.7% of 100 mg/L naphthalene, phenanthrene, anthracene, and pyrene within 15 days, respectively. When these PAHs present in a mixed form, the enhancement phenomenon appeared, particularly in the degradation of pyrene, whereas the degradation rate was 98.6% within the period. This is the first report showing the degradation of different PAHs by this species. PCR experiments with specific primers for catabolic genes alkB, alkB1, nahAc, C12O, and C23O suggested that ASU-06 might possess genes for aliphatic and PAHs degradation, while PAH-RHDαGP gene was not detected. Production of biosurfactants and increasing cell-surface hydrophobicity were investigated. GC/MS analysis of intermediate metabolites of studied PAHs concluded that this strain utilized these compounds via two main pathways, and phthalate was the major constant product that appeared in each day of the degradation period.

  2. 赤霉酸降解菌的筛选及其适宜降解条件的确定%Screening of Gibberellic Acid-degrading Strains and the Optimization of Its Degradation Conditions

    Institute of Scientific and Technical Information of China (English)

    李清平; 马丽莉; 唐洁; 黄灏; 姚开

    2012-01-01

    [ Objective] To screen a gibberellic acid-degrading strain and investigate the optimization of its degradation conditions. [ Method] An efficient gibberellic acid-degrading strain G-6 was screened from some domesticated strains tolerant to gibberellic acid ( GA3) by using basal salt medium with gibberellic acid as its only carbon source. In this paper, the effects of various factors on GA3 degradation by G-6 were investigated by single factor test and its condition for GA3 degradation was determined. [ Kesuit] The rate of GA3 degradation was up to 60.62% when the strain was incubated in 250 ml conical flask containing 40 ml mineral medium with 200 mg/L of gibberellic acid, 5. 0% of bacterial suspension and pH 7,0 on a rotary shaker (140 r/min) at 30 X for 120 h. [ Conclusion] The research supplied references for the biodegrada-tion pathway of GA3.%[目的]筛选一株赤霉酸( GA3)降解菌并探讨其适宜的降解备件.[方法]利用仅含赤霉酸为唯一碳源的基础盐培养基,对前期驯化得到的对GA3具有较强耐受性的微生物进行筛选,获得了具有较强降解GA3能力的菌株G-6;采用单因素试验系统考察了不同因素对菌株G-6降解GA3效果的影响,确定了其适宜的降解条件.[结果]在培养时间为120h、培养温度为30℃、初始pH为7.0、接种量(菌悬液OD600=1.000)为5.0% (V/V)、培养基中赤霉酸浓度为200 mg/L、摇床转速为140 r/min、250 ml锥形瓶培养基装量为40 ml的条件下,GA3降解率达到60.62%.[结论]为深入探讨GA3的生物降解途径提供了参考.

  3. Isolation and characterization of a fipronil-degrading strain R-2 and its degrading characteristics%锐劲特降解菌株R-2的分离、鉴定及降解特性

    Institute of Scientific and Technical Information of China (English)

    宋瑶; 李荣; 王融; 张曼曼; 杨洪杏; 李顺鹏; 蒋建东

    2011-01-01

    A bacterial strain R-2, capable of degrading fipronil, was isolated from a long-term fipronil-polluted activated sludge in a fipronil manufacture factory. Strain R-2 was preliminarily identified as Paracoccus sp. based on its physiological and biochemical properties, as well as the 16S rRNA gene sequence analysis. Strain R-2 could utilize fipronil as the sole carbon source for growth, and degrade 85% of 50 mg/L fipronil within 3 d in mineral salts medium. The optimal pH value and temperature for fipronil degradation by strain R-2 were 6.0-7.0 and 30 ℃, respectively. The degrading rate showed a negative correlation with the initial concentration of fipronil. The addition of 0.1 mmol/L Zn2+or Fe3+ to the culture medium could significantly increase the degradation of fipronil. In both sterile and non-sterile soils, strain could remove 63.4%-71.2% of 100 μg/g fipronil within 10 d.%从长期受锐劲特污染的农药厂活性污泥中分离到一株锐劲特降解菌株R-2,根据其生理生化特征和16S rRNA基因序列同源性分析.将该菌株鉴定为Paracoccus sp..菌株R-2能以锐劲特为唯一碳源生长,在含有50 mg/L的锐劲特的基础盐培养基中,3 d的降解率达到85%.菌株R-2降解锐劲特的最适温度为30℃,最适pH值为6.0-7.0,其降解锐劲特的效率与锐劲特初始浓度呈负相关.添加0.1 mmol/L的Zn或Fe能够显著促进菌株对锐劲特的降解.灭菌与非灭菌土壤降解试验表明,菌株R-2均可以在10 d内降解63.4%-71.2%的100 μg/g的锐劲特.

  4. Plasmid dependence of Pseudomonas sp. strain NK87 enzymes that degrade 6-aminohexanoate-cyclic dimer.

    Science.gov (United States)

    Kanagawa, K; Negoro, S; Takada, N; Okada, H

    1989-06-01

    A bacterial strain, Pseudomonas sp. strain NK87, that can use 6-aminohexanoate-cyclic dimer as the sole source of carbon and nitrogen was newly isolated from wastewater of a factory which produces nylon-6. Two responsible enzymes, 6-aminohexanoate-cyclic-dimer hydrolase (P-EI) and 6-aminohexanoate-dimer hydrolase (P-EII), were found in the NK87 strain, as is the case with Flavobacterium sp. strain KI72, another 6-aminohexanoate-cyclic-dimer-metabolizing bacterium (H. Okada, S. Negoro, H. Kimura, and S. Nakamura, Nature [London] 306:203-206, 1983). The P-EI enzyme is immunologically identical to the 6-aminohexanoate-cyclic-dimer hydrolase of KI72 (F-EI). However, antiserum against the 6-aminohexanoate-dimer hydrolase purified from KI72 (F-EII) did not react with cell extracts of NK87, indicating that the F-EII and P-EII enzymes are immunologically different. Restriction endonuclease analyses show that the NK87 strain harbors at least six plasmids ranging in size from 20 to 80 kilobase pairs (kbp). The P-EI and P-EII genes were cloned in Escherichia coli. Both the P-EI and F-EI probes strongly hybridized with a 23-kbp plasmid in Southern hybridization analyses. The P-EII probe hybridized specifically with an 80-kbp plasmid, but the F-EII probe hybridized with none of the plasmids harbored in NK87. These results indicate that the P-EI gene and P-EII gene are encoded on the 23-kbp and 80-kbp plasmids, respectively.

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

    Science.gov (United States)

    Kilany, Mona

    2017-04-01

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

  6. Effect of catchment land use and soil type on the concentration, quality, and bacterial degradation of riverine dissolved organic matter

    DEFF Research Database (Denmark)

    Autio, Iida; Soinne, Helena; Helin, Janne;

    2016-01-01

    of dissolved organic carbon, nitrogen, and phosphorus (DOC, DON, and DOP, respectively), and was linked to DOM quality. Soil type was more important than land use in determining the concentration and quality of riverine DOM. On average, 5–9 % of the DOC and 45 % of the DON were degraded by the bacterial......We studied the effects of catchment characteristics (soil type and land use) on the concentration and quality of dissolved organic matter (DOM) in river water and on the bacterial degradation of terrestrial DOM. The share of organic soil was the strongest predictor of high concentrations...... communities within 2–3 months. Simultaneously, the proportion of humic-like compounds in the DOM pool increased. Bioavailable DON accounted for approximately one-third of the total bioavailable dissolved nitrogen, and thus, terrestrial DON can markedly contribute to the coastal plankton dynamics and support...

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

    Science.gov (United States)

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

    2012-08-01

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

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

    Directory of Open Access Journals (Sweden)

    Lorraine P. Smith

    2011-01-01

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

  9. Genetic and biochemical diversity of Gardnerella vaginalis strains isolated from women with bacterial vaginosis.

    Science.gov (United States)

    Pleckaityte, Milda; Janulaitiene, Migle; Lasickiene, Rita; Zvirbliene, Aurelija

    2012-06-01

    Gardnerella vaginalis is considered a substantial player in the progression of bacterial vaginosis (BV). We analysed 17 G. vaginalis strains isolated from the genital tract of women diagnosed with BV to establish a potential link between genotypes/biotypes and the expression of virulence factors, vaginolysin (VLY) and sialidase, which are assumed to play a substantial role in the pathogenesis of BV. Amplified ribosomal DNA restriction analysis revealed two G. vaginalis genotypes. Gardnerella vaginalis isolates of genotype 2 appeared more complex than genotype 1 and were subdivided into three subtypes. Biochemical typing allowed us to distinguish four different biotypes. A great diversity of the level of VLY production among the isolates of G. vaginalis may be related to a different cytotoxicity level of the strains. We did not find any correlation between VLY production level and G. vaginalis genotype/biotype. In contrast, a link between G. vaginalis genotype and sialidase production was established. Our findings on the diversity of VLY expression level in different clinical isolates and linking sialidase activity with the genotype of G. vaginalis could help to evaluate the pathogenic potential of different G. vaginalis strains.

  10. Bioremediation potential of a highly mercury resistant bacterial strain Sphingobium SA2 isolated from contaminated soil.

    Science.gov (United States)

    Mahbub, Khandaker Rayhan; Krishnan, Kannan; Megharaj, Mallavarapu; Naidu, Ravi

    2016-02-01

    A mercury resistant bacterial strain, SA2, was isolated from soil contaminated with mercury. The 16S rRNA gene sequence of this isolate showed 99% sequence similarity to the genera Sphingobium and Sphingomonas of α-proteobacteria group. However, the isolate formed a distinct phyletic line with the genus Sphingobium suggesting the strain belongs to Sphingobium sp. Toxicity studies indicated resistance to high levels of mercury with estimated EC50 values 4.5 mg L(-1) and 44.15 mg L(-1) and MIC values 5.1 mg L(-1) and 48.48 mg L(-1) in minimal and rich media, respectively. The strain SA2 was able to volatilize mercury by producing mercuric reductase enzyme which makes it potential candidate for remediating mercury. ICP-QQQ-MS analysis of Hg supplemented culture solutions confirmed that almost 79% mercury in the culture suspension was volatilized in 6 h. A very small amount of mercury was observed to accumulate in cell pellets which was also evident according to ESEM-EDX analysis. The mercuric reductase gene merA was amplified and sequenced. The deduced amino acid sequence demonstrated sequence homology with α-proteobacteria and Ascomycota group.

  11. Bacteroides uniformis is a putative bacterial species associated with the degradation of the isoflavone genistein in human feces.

    Science.gov (United States)

    Renouf, Mathieu; Hendrich, Suzanne

    2011-06-01

    Inter-individual variation in isoflavone absorption depends on gut microbial degradation and affects the efficacy of these compounds. We hypothesized that inter-individual variation in fecal isoflavone disappearance coincided with variation in bacterial species. In vitro anaerobic fecal disappearance of isoflavones was measured from 33 participants by HPLC. Fecal microbial 16S rRNA variable region PCR products were obtained from 4 participants with the greatest and least genistein or glycitein degradation and were subjected to denaturing gradient gel electrophoresis. DNA bands with a homology of 90-95% to Bacteroides uniformis and Faecalibacterium prausnitzii were present in greater intensities in fecal samples showing a genistein disappearance rate constant of 1.47 ± 0.14 h(-1) compared with those with a genistein disappearance rate constant of 0.15 ± 0.03 h(-1) (P < 0.05). Human fecal bacterial species with DNA sequences 90-100% homologous to Tannerella forsythensis and 4 other species were present in greater intensities in fecal samples showing a glycitein disappearance rate constant of 0.57 ± 0.30 h(-1) compared with fecal samples with a glycitein disappearance rate constant of 0.08 ± 0.03 h(-1) (P < 0.05). In high degraders, B. uniformis may be a candidate for genistein degradation and T. forsythensis for glycitein degradation, based on fecal isoflavone degradation in the presence of these species. Bacteroides acidifaciens increased isoflavone disappearance in anaerobic human fecal incubations under nutrient-rich and -depleted conditions, suggesting this species as one responsible for the generally high degradation of isoflavones by humans. These fecal microbes are candidate biomarkers for interindividual variation in isoflavone uptake and efficacy.

  12. Degradation and mineralization of high-molecular-weight polycyclic aromatic hydrocarbons by defined fungal-bacterial cocultures

    Energy Technology Data Exchange (ETDEWEB)

    Boonchan, S.; Britz, M.L.; Stanley, G.A.

    2000-03-01

    This study investigated the biodegradation of high-molecular-weight polycyclic aromatic hydrocarbons (PAHs) in liquid media and soil by bacteria (Stenotrophomonas maltophilia VUN 10,010 and bacterial consortium VUN 10,009) and a fungus (Penicillium janthinellum VUO 10,201) that were isolated from separate creosote- and manufactured-gas plant-contaminated soils. The bacteria could use pyrene as their sole carbon and energy source in a basal salts medium (BSM) and mineralized significant amounts of benzo[a]pyrene cometabolically when pyrene was also present in BSM. P. janthinellum VUO 10,201 could not utilize any high-molecular-weight PAH as sole carbon and energy source but could partially degrade these if cultured in a nutrient broth. Although small amounts of chrysene, benz[a]pyrene, and dibenz[a,h]anthracene were degraded by axenic cultures of these isolates in BSM containing a single PAH, such conditions did not support significant microbial growth or PAH mineralization. However, significant degradation of, and microbial growth on, pyrene, chrysene, benz[a]anthracene, benzo[a]pyrene, and dibenz[a,h]anthracene, each as a single PAH in BSM, occurred when P. janthinellum VUO 10,201 and either bacterial consortium VUN 10,009 or S. maltophilia VUN 10,010 were combined in the one culture, i.e., fungal-bacterial cocultures: 25% of the benzo[a]pyrene was mineralized to CO{sub 2} by these cocultures over 49 days, accompanied by transient accumulation and disappearance of intermediates detected by high-pressure liquid chromatography. Inoculation of fungal-bacterial cocultures into PAH-contaminated soil resulted in significantly improved degradation of high-molecular-weight PAHs, benzo[a]pyrene mineralization, and reduction in the mutagenicity of organic soil extracts, compared with the indigenous microbes and soil amended with only axenic inocula.

  13. Degradation and mineralization of high-molecular-weight polycyclic aromatic hydrocarbons by defined fungal-bacterial cocultures.

    Science.gov (United States)

    Boonchan, S; Britz, M L; Stanley, G A

    2000-03-01

    This study investigated the biodegradation of high-molecular-weight polycyclic aromatic hydrocarbons (PAHs) in liquid media and soil by bacteria (Stenotrophomonas maltophilia VUN 10,010 and bacterial consortium VUN 10,009) and a fungus (Penicillium janthinellum VUO 10, 201) that were isolated from separate creosote- and manufactured-gas plant-contaminated soils. The bacteria could use pyrene as their sole carbon and energy source in a basal salts medium (BSM) and mineralized significant amounts of benzo[a]pyrene cometabolically when pyrene was also present in BSM. P. janthinellum VUO 10,201 could not utilize any high-molecular-weight PAH as sole carbon and energy source but could partially degrade these if cultured in a nutrient broth. Although small amounts of chrysene, benz[a]anthracene, benzo[a]pyrene, and dibenz[a,h]anthracene were degraded by axenic cultures of these isolates in BSM containing a single PAH, such conditions did not support significant microbial growth or PAH mineralization. However, significant degradation of, and microbial growth on, pyrene, chrysene, benz[a]anthracene, benzo[a]pyrene, and dibenz[a,h]anthracene, each as a single PAH in BSM, occurred when P. janthinellum VUO 10,201 and either bacterial consortium VUN 10,009 or S. maltophilia VUN 10,010 were combined in the one culture, i.e., fungal-bacterial cocultures: 25% of the benzo[a]pyrene was mineralized to CO(2) by these cocultures over 49 days, accompanied by transient accumulation and disappearance of intermediates detected by high-pressure liquid chromatography. Inoculation of fungal-bacterial cocultures into PAH-contaminated soil resulted in significantly improved degradation of high-molecular-weight PAHs, benzo[a]pyrene mineralization (53% of added [(14)C]benzo[a]pyrene was recovered as (14)CO(2) in 100 days), and reduction in the mutagenicity of organic soil extracts, compared with the indigenous microbes and soil amended with only axenic inocula.

  14. Comparison of Paraffin and Diesel Oil as Cultivation Medium Supplements for Preparing a Hydrocarbon-Degrading Bacterial Biomass

    Directory of Open Access Journals (Sweden)

    Dokukins Eduards

    2016-05-01

    Full Text Available The effect of liquid paraffin and diesel oil as nutrient amendments for hydrocarbon-degrading bacteria was compared. Different parameters were analyzed - optical density of bacterial suspension, oxygen consumption by biomass, morphology of bacteria, etc. In some experiments the paraffin was more preferable for microorganisms, but in other tests the results for both substances were similar. The influence of the comparable substances strongly depends on cultivation conditions.

  15. Genome sequencing and systems biology analysis of a lipase-producing bacterial strain.

    Science.gov (United States)

    Li, N; Li, D D; Zhang, Y Z; Yuan, Y Z; Geng, H; Xiong, L; Liu, D L

    2016-03-18

    Lipase-producing bacteria are naturally-occurring, industrially-relevant microorganisms that produce lipases, which can be used to synthesize biodiesel from waste oils. The efficiency of lipase expression varies between various microbial strains. Therefore, strains that can produce lipases with high efficiency must be screened, and the conditions of lipase metabolism and optimization of the production process in a given environment must be thoroughly studied. A high efficiency lipase-producing strain was isolated from the sediments of Jinsha River, identified by 16S rRNA sequence analysis as Serratia marcescens, and designated as HS-L5. A schematic diagram of the genome sequence was constructed by high-throughput genome sequencing. A series of genes related to lipid degradation were identified by functional gene annotation through sequence homology analysis. A genome-scale metabolic model of HS-ML5 was constructed using systems biology techniques. The model consisted of 1722 genes and 1567 metabolic reactions. The topological graph of the genome-scale metabolic model was compared to that of conventional metabolic pathways using a visualization software and KEGG database. The basic components and boundaries of the tributyrin degradation subnetwork were determined, and its flux balance analyzed using Matlab and COBRA Toolbox to simulate the effects of different conditions on the catalytic efficiency of lipases produced by HS-ML5. We proved that the catalytic activity of microbial lipases was closely related to the carbon metabolic pathway. As production and catalytic efficiency of lipases varied greatly with the environment, the catalytic efficiency and environmental adaptability of microbial lipases can be improved by proper control of the production conditions.

  16. Molecular analysis of the bacterial diversity in a specialized consortium for diesel oil degradation

    Energy Technology Data Exchange (ETDEWEB)

    Paixao, Douglas Antonio Alvaredo; Accorsini, Fabio Raphael; Vidotti, Maria Benincasa; Lemos, Eliana Gertrudes de Macedo [Universidade Estadual Paulista (FCAV/UNESP), Jaboticabal, SP (Brazil). Fac. de Ciencias Agrarias e Veterinarias], Emails: douglas_unespfcav@yahoo.com.br, vidotti@netsite.com.bregerle@fcav.unesp.br; Dimitrov, Mauricio Rocha [Universidade de Sao Paulo (USP), SP (Brazil)], Email: mau_dimitrov@yahoo.com.br; Pereira, Rodrigo Matheus [EMBRAPARA Soybean - Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA - Soja), Londrina, PR (Brazil)], Email: poetbr@gmail.com

    2010-05-15

    Diesel oil is a compound derived from petroleum, consisting primarily of hydrocarbons. Poor conditions in transportation and storage of this product can contribute significantly to accidental spills causing serious ecological problems in soil and water and affecting the diversity of the microbial environment. The cloning and sequencing of the 16S rRNA gene is one of the molecular techniques that allows estimation and comparison of the microbial diversity in different environmental samples. The aim of this work was to estimate the diversity of microorganisms from the Bacteria domain in a consortium specialized in diesel oil degradation through partial sequencing of the 16S rRNA gene. After the extraction of DNA metagenomics, the material was amplified by PCR reaction using specific oligonucleotide primers for the 16S rRNA gene. The PCR products were cloned into a pGEM-T-Easy vector (Promega), and Escherichia coli was used as the host cell for recombinant DNAs. The partial clone sequencing was obtained using universal oligonucleotide primers from the vector. The genetic library obtained generated 431 clones. All the sequenced clones presented similarity to phylum Proteobacteria, with Gammaproteobacteria the most present group (49.8 % of the clones), followed by Alphaproteobacteira (44.8 %) and Betaproteobacteria (5.4 %). The Pseudomonas genus was the most abundant in the metagenomics library, followed by the Parvibaculum and the Sphingobium genus, respectively. After partial sequencing of the 16S rRNA, the diversity of the bacterial consortium was estimated using DOTUR software. When comparing these sequences to the database from the National Center for Biotechnology Information (NCBI), a strong correlation was found between the data generated by the software used and the data deposited in NCBI. (author)

  17. Controlled fermentation of Moroccan picholine green olives by oleuropein-degrading Lactobacilli strains

    Energy Technology Data Exchange (ETDEWEB)

    Ghabbour, N.; Rokni, Y.; Lamzira, Z.; Thonart, P.; Chihib, N.E.; Peres, C.; Asehraou, A.

    2016-07-01

    The control of the spontaneous fermentation process of un-debittered Moroccan Picholine green olives was undertaken basing the inoculation with two lactobacilli strains (Lactobacillus plantarum S175 and Lactobacillus pentosus S100). These strains, previously selected in our laboratory for their oleuropein-degrading capacity, were inoculated in olives brined at 5% of NaCl, and then incubated at 30 °C. The physico-chemical parameters (pH, free acidity, reducing sugars, sodium chloride, oleuropein and its hydrolysis products), and the microbiological parameters (mesophilic aerobic bacteria, coliforms, Staphylococcus, lactic acid bacteria and yeasts and moulds), were regularly analyzed during the fermentation time. The results obtained showed the effectiveness of the lactic acid bacteria strains to develop suitable oleuropein biodegradation and controlled lactic fermentation processes more than the un-inoculated olives (control). This result was confirmed by the rapid elimination of coliforms and staphylococcus, the accumulation of hydroxytyrosol as a result of oleuropein biodegradation, and a drastic reduction in spoiled olives with good quality fermented olives. (Author)

  18. NKLP27: a teleost NK-lysin peptide that modulates immune response, induces degradation of bacterial DNA, and inhibits bacterial and viral infection.

    Science.gov (United States)

    Zhang, Min; Li, Mo-fei; Sun, Li

    2014-01-01

    NK-lysin is an antimicrobial protein produced by cytotoxic T lymphocytes and natural killer cells. In this study, we examined the biological property of a peptide, NKLP27, derived from tongue sole (Cynoglossus semilaevis) NK-lysin. NKLP27 is composed of 27 amino acids and shares little sequence identity with known NK-lysin peptides. NKLP27 possesses bactericidal activity against both Gram-negative and Gram-positive bacteria including common aquaculture pathogens. The bactericidal activity of NKLP27 was dependent on the C-terminal five residues, deletion of which dramatically reduced the activity of NKLP27. During its interaction with the target bacterial cells, NKLP27 destroyed cell membrane integrity, penetrated into the cytoplasm, and induced degradation of genomic DNA. In vivo study showed that administration of tongue sole with NKLP27 before bacterial and viral infection significantly reduced pathogen dissemination and replication in tissues. Further study revealed that fish administered with NKLP27 exhibited significantly upregulated expression of the immune genes including those that are known to be involved in antibacterial and antiviral defense. These results indicate that NKLP27 is a novel antimicrobial against bacterial and viral pathogens, and that the observed effect of NKLP27 on bacterial DNA and host gene expression adds new insights to the action mechanism of fish antimicrobial peptides.

  19. NKLP27: a teleost NK-lysin peptide that modulates immune response, induces degradation of bacterial DNA, and inhibits bacterial and viral infection.

    Directory of Open Access Journals (Sweden)

    Min Zhang

    Full Text Available NK-lysin is an antimicrobial protein produced by cytotoxic T lymphocytes and natural killer cells. In this study, we examined the biological property of a peptide, NKLP27, derived from tongue sole (Cynoglossus semilaevis NK-lysin. NKLP27 is composed of 27 amino acids and shares little sequence identity with known NK-lysin peptides. NKLP27 possesses bactericidal activity against both Gram-negative and Gram-positive bacteria including common aquaculture pathogens. The bactericidal activity of NKLP27 was dependent on the C-terminal five residues, deletion of which dramatically reduced the activity of NKLP27. During its interaction with the target bacterial cells, NKLP27 destroyed cell membrane integrity, penetrated into the cytoplasm, and induced degradation of genomic DNA. In vivo study showed that administration of tongue sole with NKLP27 before bacterial and viral infection significantly reduced pathogen dissemination and replication in tissues. Further study revealed that fish administered with NKLP27 exhibited significantly upregulated expression of the immune genes including those that are known to be involved in antibacterial and antiviral defense. These results indicate that NKLP27 is a novel antimicrobial against bacterial and viral pathogens, and that the observed effect of NKLP27 on bacterial DNA and host gene expression adds new insights to the action mechanism of fish antimicrobial peptides.

  20. Complete genome sequence and transcriptomic analysis of a novel marine strain Bacillus weihaiensis reveals the mechanism of brown algae degradation.

    Science.gov (United States)

    Zhu, Yueming; Chen, Peng; Bao, Yunjuan; Men, Yan; Zeng, Yan; Yang, Jiangang; Sun, Jibin; Sun, Yuanxia

    2016-11-30

    A novel marine strain representing efficient degradation ability toward brown algae was isolated, identified, and assigned to Bacillus weihaiensis Alg07. The alga-associated marine bacteria promote the nutrient cycle and perform important functions in the marine ecosystem. The de novo sequencing of the B. weihaiensis Alg07 genome was carried out. Results of gene annotation and carbohydrate-active enzyme analysis showed that the strain harbored enzymes that can completely degrade alginate and laminarin, which are the specific polysaccharides of brown algae. We also found genes for the utilization of mannitol, the major storage monosaccharide in the cell of brown algae. To understand the process of brown algae decomposition by B. weihaiensis Alg07, RNA-seq transcriptome analysis and qRT-PCR were performed. The genes involved in alginate metabolism were all up-regulated in the initial stage of kelp degradation, suggesting that the strain Alg07 first degrades alginate to destruct the cell wall so that the laminarin and mannitol are released and subsequently decomposed. The key genes involved in alginate and laminarin degradation were expressed in Escherichia coli and characterized. Overall, the model of brown algae degradation by the marine strain Alg07 was established, and novel alginate lyases and laminarinase were discovered.

  1. Bacterial community analysis of an industrial wastewater treatment plant in Colombia with screening for lipid-degrading microorganisms.

    Science.gov (United States)

    Silva-Bedoya, Lina Marcela; Sánchez-Pinzón, María Solange; Cadavid-Restrepo, Gloria Ester; Moreno-Herrera, Claudia Ximena

    2016-11-01

    The operation of wastewater treatment technologies depends on a combination of physical, chemical and biological factors. Microorganisms present in wastewater treatment plants play essential roles in the degradation and removal of organic waste and xenobiotic pollutants. Several microorganisms have been used in complementary treatments to process effluents rich in fats and oils. Microbial lipases have received significant industrial attention because of their stability, broad substrate specificity, high yields, and regular supply, as well as the fact that the microorganisms producing them grow rapidly on inexpensive media. In Colombia, bacterial community studies have focused on populations of cultivable nitrifying, heterotrophic and nitrogen-fixing bacteria present in constructed wetlands. In this study, culture-dependent methods, culture-independent methods (TTGE, RISA) and enzymatic methods were used to estimate bacterial diversity, to monitor temporal and spatial changes in bacterial communities, and to screen microorganisms that presented lipolytic activity. The dominant microorganisms in the Wastewater Treatment Plant (WWTP) examined in this study belonged to the phyla Firmicutes, Proteobacteria and Bacteroidetes. The enzymatic studies performed indicated that five bacterial isolates and three fungal isolates possessed the ability to degrade lipids; additionally, the Serratia, Kosakonia and Mucor genera presented lipase-mediated transesterification activity. The implications of these findings in regard to possible applications are discussed later in this paper. Our results indicate that there is a wide diversity of aerobic Gram-negative bacteria inhabiting the different sections of the WWTP, which could indicate its ecological condition, functioning and general efficiency.

  2. A suite of recombinant luminescent bacterial strains for the quantification of bioavailable heavy metals and toxicity testing

    Directory of Open Access Journals (Sweden)

    Kahru Anne

    2009-05-01

    Full Text Available Abstract Background Recombinant whole-cell sensors have already proven useful in the assessment of the bioavailability of environmental pollutants like heavy metals and organic compounds. In this work 19 recombinant bacterial strains representing various Gram-positive (Staphylococcus aureus and Bacillus subtilis and Gram-negative (Escherichia coli, Pseudomonas fluorescens bacteria were constructed to express the luminescence encoding genes luxCDABE (from Photorhabdus luminescens as a response to bioavailable heavy metals ("lights-on" metal sensors containing metal-response elements, 13 strains or in a constitutive manner ("lights-off" constructs, 6 strains. Results The bioluminescence of all 13 "lights-on" metal sensor strains was expressed as a function of the sub-toxic metal concentrations enabling the quantitative determination of metals bioavailable for these strains. Five sensor strains, constructed for detecting copper and mercury, proved to be target metal specific, whereas eight other sensor strains were simultaneously induced by Cd2+, Hg2+, Zn2+and Pb2+. The lowest limits of determination of the "lights-on" sensor strains for the metals tested in this study were (μg l-1: 0.002 of CH3HgCl, 0.03 of HgCl2, 1.8 of CdCl2, 33 of Pb(NO32, 1626 of ZnSO4, 24 of CuSO4 and 340 of AgNO3. In general, the sensitivity of the "lights-on" sensor strains was mostly dependent on the metal-response element used while the selection of host bacterium played a relatively minor role. In contrast, toxicity of metals to the "lights-off" strains was only dependent on the bacterial host so that Gram-positive strains were remarkably more sensitive than Gram-negative ones. Conclusion The constructed battery of 19 recombinant luminescent bacterial strains exhibits several novel aspects as it contains i metal sensor strains with similar metal-response elements in different host bacteria; ii metal sensor strains with metal-response elements in different copies and iii

  3. Bacterial communities predominant in the degradation of 13C(4)-4,5,9,10-pyrene during composting.

    Science.gov (United States)

    Peng, Jingjing; Zhang, Yuan; Su, Jianqiang; Qiu, Qiongfen; Jia, Zhongjun; Zhu, Yong-Guan

    2013-09-01

    An in-vessel composting bioremediation of (13)C4-4,5,9,10-pyrene and unlabeled pyrene spiked soil amended with fresh wastes was investigated by DNA-based stable isotope probing (SIP) of active bacteria involved. Highest dissipation of (13)C4-pyrene was detected at 55 °C after 42 days composting. The active bacterial communities in the composting changed over time, showing a distinct difference among different stages. α-, β-, γ-Proteobacteria, and Actinobacteria were detected mainly involving in pyrene degradation at 38 °C over 14 days composting. Streptomyces appeared to dominate the pyrene degradation at 55 °C. β- and γ-Proteobacteria and Actinobacteria were the dominant pyrene degraders at 70 °C after 42 days composting and at 38 °C after 60 days composting. The results of this study suggest the pyrene degradation was performed by phylogenetically distinct bacterial guilds from the phyla Actinobacteria and Proteobacteria during in-vessel composition processes.

  4. Enhanced remediation of chlorpyrifos by ryegrass (Lolium multiflorum) and a chlorpyrifos degrading bacterial endophyte Mezorhizobium sp. HN3.

    Science.gov (United States)

    Jabeen, Hina; Iqbal, Samina; Ahmad, Fiaz; Afzal, Muhammad; Firdous, Sadiqa

    2016-01-01

    For effective remediation of contaminants, plant-endophyte partnership is a promising field to be explored. Generally endophytic bacteria assist their host plant by withstanding the stress induced by the contaminants. The objective of this study was to explore the suitability of plant-bacterial partnership for chlorpyrifos (CP) remediation using ryegrass and a CP degrading endophyte, Mesorhizobium sp. HN3 which belongs to plant growth promoting rhizobia. The inoculated yfp-tagged Mesorhizobium sp. HN3 efficiently colonized in the rhizosphere, enhanced plant growth and degradation of CP and its metabolite 3,5,6 trichloro-2-pyridinol (TCP). Significantly lower CP residues were observed in the roots and shoots of plants vegetated in inoculated soil which might be attributed to the efficient root colonization of HN3yfp. These results suggest the involvement of Mesorhizobium sp. HN3yfp in CP degradation inside the roots and rhizosphere of plants and further emphasize on the effectiveness of endophytic bacteria in stimulating the remediation of pesticide contaminants. This is the first report which demonstrates the efficacy of bacterial endophyte for degradation of CP residues taken up by the plant and enhanced remediation of chlorpyrifos contaminated soil.

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

    Directory of Open Access Journals (Sweden)

    Rahat Abdul Rehman

    2015-11-01

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

  6. Screening and degrading characteristics and community structure of a high molecular weight polycyclic aromatic hydrocarbon-degrading bacterial consortium from contaminated soil

    Institute of Scientific and Technical Information of China (English)

    Run Sun; Jinghua Jin; Guangdong Sun; Ying Liu; Zhipei Liu

    2010-01-01

    Inoculation with efficient microbes had been proved to be the most important way for the bioremediation of polluted environments.For the treatment of abandoned site of Beijing Coking Chemical Plant contaminated with high level of high-molecular-weight polycyclic aromatic hydrocarbons (HMW-PAHs),a bacterial consortium capable of degrading HMW-PAHs,designated 1-18-1,was enriched and screened from HMW-PAHs contaminated soil.Its degrading ability was analyzed by high performance liquid chromatography (HPLC),and the community structure was investigated by construction and analyses of the 16S rRNA gene clone libraries (A,B and F) at different transfers.The results indicated that 1-18-1 was able to utilize pyrene,fluoranthene and benzo[a]pyrene as sole carbon and energy source for growth.The degradation rate of pyrene and fluoranthene reached 82.8% and 96.2% after incubation for 8 days at 30℃,respectively;while the degradation rate of benzo[a]pyrene was only 65.1% after incubation for 28 days at 30℃.Totally,108,100 and 100 valid clones were randomly selected and sequenced from the libraries A,B,and E Phylogenetic analyses showed that all the clones could be divided into 5 groups,Bacteroidetes,α-Proteobacteria,Actinobacteria,β-Proteobacteria and γ-Proteobacteria.Sequence similarity analyses showed total 39 operational taxonomic units (OTUs) in the libraries.The predominant bacterial groups were α-Proteobacteria (19 OTUs,48.7%),γ-Proteobacteria (9 OTUs,23.1%) and β-Protcobacteria (8 OTUs,20.5%).During the transfer process,the proportions of α-Proteobacteria and β-Proteobacteria increased greatly (from 47% to 93%),while γ-Proteobacteria decreased from 32% (library A) to 6% (library F);and Bacteroidetes group disappeared in libraries B and F.

  7. In vitro antimicrobial activity of marbofloxacin and enrofloxacin against bacterial strains isolated from companion animals.

    Science.gov (United States)

    Farca, A M; Cavana, P; Robino, P; Nebbia, P

    2007-06-01

    Fluoroquinolones were originally developed for the Gram-negative aerobic spectrum, but the newer generation agents are also highly effective against some Gram-positive pathogens and cause few adverse effects. Owing to these characteristics, fluoroquinolones are often used in first line therapy in small animal practice. However, their widespread use has raised concern over emerging bacterial resistance. In this study we evaluated the in vitro efficacy of two fluoroquinolones, marbofloxacin and enrofloxacin, on field strains isolated from clinical infections between 2002 and 2005. Our data show that most of the isolates are still sensitive to both antimicrobials and marbofloxacin was more effective than enrofloxacin, especially against P. aeruginosa and beta-Streptococci (P < 0.01). beta-Streptococci demonstrated the greatest resistance to the two study drugs.

  8. Isolation of Marine Polycyclic Aromatic Hydrocarbon (PAH)-Degrading Cycloclasticus Strains from the Gulf of Mexico and Comparison of Their PAH Degradation Ability with That of Puget Sound Cycloclasticus Strains

    OpenAIRE

    1998-01-01

    Phenanthrene- and naphthalene-degrading bacteria were isolated from four offshore and nearshore locations in the Gulf of Mexico by using a modified most-probable-number technique. The concentrations of these bacteria ranged from 102 to 106 cells per ml of wet surficial sediment in mildly contaminated and noncontaminated sediments. A total of 23 strains of polycyclic aromatic hydrocarbon (PAH)-degrading bacteria were obtained. Based on partial 16S ribosomal DNA sequences and phenotypic charact...

  9. Isolation and Characterization of a Acetochlor-degrading Strain Y-4 and Its Degrading Characteristics%乙草胺降解菌Y-4的分离鉴定及降解特性研究

    Institute of Scientific and Technical Information of China (English)

    倪俊; 沈维亮; 闫新; 李顺鹏

    2011-01-01

    Acetochlor were widely used to weeding in agriculture and resulted in severely environmental pollution. Bioremediation is an effective and economic method to treat the environment that has been polluted by acetochlor. So researchers paid much attention in this area. In the present study, a bacterial strain Y-4 capable of utilizing acetochlor as sole carbon and energy sources was isolated from the sludge that have long been subjected to acetochlor pollution by enrichment method The Y-4 cells were short rod, Gram nesative. The colonies on LB media were light yellow in color, circular, and smooth. Strain Y-4 was identified preliminarily as Shinella sp. based on its physiological and biochemical characters and the result of the 16S rDNA homologue sequence analysis. The Y-4 strain could effectively degrade acetochlor ranging of 5-200 mg·L-1. 50 mg· L-1 acetochlor could be degraded at a rate of 83.3% by Y-4 strain in 48 h. The optimal initial pH value and temperature for acetochlor degradation by Y-4 was 8.0 and 30 ℃, respectively. Adding extra glucose or nitrogen source promoted the growth of strain Y-4, but influence the degradation of acetochlor slightly. The ion Mg2+ could promote the strain to degrade acetochlor slightly, and Ni2+, Co2+, Hg2+ could inhibit it when it was at low level. However, Zn2+, Fe2+ had no effect on the degradation of acetochlor. Strain Y-4 could also degrade some other pesticides such as pretilachlor and butachlor.%从长期经乙草胺污染的污泥中分离到一株能以乙草胺为唯一碳源和能源生长的菌株Y-4,通过生理生化实验和l6S rDNA同源性序列分析,鉴定为申氏杆菌属(Shinella sp.).采用室内培养方法,研究了Y-4对乙草胺的降解特性.结果表明,Y-4能有效地降解浓度为5~200mg·L-1的乙草胺,在48 h内对50 mg·L-1乙草胺的降解率达到83.3%.菌株Y-4降解乙草胺的最适pH值为8.0,最适温度为30℃,其对丙草胺和丁草胺等农药也有良好的降解效果.

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

    Science.gov (United States)

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

    2012-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Junfang Zhou

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

  12. Production of volatile aroma compounds by bacterial strains isolated from different surface-ripened French cheeses.

    Science.gov (United States)

    Deetae, Pawinee; Bonnarme, Pascal; Spinnler, Henry E; Helinck, Sandra

    2007-10-01

    Twelve bacterial strains belonging to eight taxonomic groups: Brevibacterium linens, Microbacterium foliorum, Arthrobacter arilaitensis, Staphylococcus cohnii, Staphylococcus equorum, Brachybacterium sp., Proteus vulgaris and Psychrobacter sp., isolated from different surface-ripened French cheeses, were investigated for their abilities to generate volatile aroma compounds. Out of 104 volatile compounds, 54 volatile compounds (identified using dynamic headspace technique coupled with gas chromatography-mass spectrometry [GC-MS]) appeared to be produced by the different bacteria on a casamino acid medium. Four out of eight species used in this study: B. linens, M. foliorum, P. vulgaris and Psychrobacter sp. showed a high flavouring potential. Among these four bacterial species, P. vulgaris had the greatest capacity to produce not only the widest varieties but also the highest quantities of volatile compounds having low olfactive thresholds such as sulphur compounds. Branched aldehydes, alcohols and esters were produced in large amounts by P. vulgaris and Psychrobacter sp. showing their capacity to breakdown the branched amino acids. This investigation shows that some common but rarely mentioned bacteria present on the surface of ripened cheeses could play a major role in cheese flavour formation and could be used to produce cheese flavours.

  13. Disentangling the interactions between photochemical and bacterial degradation of dissolved organic matter: amino acids play a central role.

    Science.gov (United States)

    Amado, André M; Cotner, James B; Cory, Rose M; Edhlund, Betsy L; McNeill, Kristopher

    2015-04-01

    Photochemical and bacterial degradation are important pathways to carbon mineralization and can be coupled in dissolved organic matter (DOM) decomposition. However, details of several mechanisms of the coupled photochemical and biological processing of DOM remain too poorly understood to achieve accurate predictions of the impact of these processes on DOM fate and reactivity. The aim of this study was to evaluate how photochemical degradation of amino acids affects bacterial metabolism and whether or not photochemical degradation of DOM competes for amino acids with biological processes. We examined the interactions between photochemical and bacterial degradation dynamics using a mixture of 18 amino acids and examined their dynamics and turnover rates within a larger pool of allochthonous or autochthonous DOM. We observed that photochemical exposure of DOM containing amino acids led to delayed biomass production (even though the final biomass did not differ), most likely due to a need for upregulation of biosynthetic pathways for amino acids that were damaged by photochemically produced reactive oxygen species (ROS). This response was most pronounced in bacterial communities where the abundance of photosensitive amino acids was highest (amended treatments and autochthonous DOM) and least pronounced when the abundance of these amino acids was low (unamended and allochthonous DOM), likely because these bacteria already had these biosynthetic pathways functioning. We observed both a cost and benefit associated with photochemical exposure of DOM. We observed a cost associated with photochemically produced ROS that partially degrade key amino acids and a benefit associated with an increase in the availability of other compounds in the DOM. Bacteria growing on DOM sources that are low in labile amino acids, such as those in terrestrially influenced environments, experience more of the benefits associated with photochemical exposure, whereas bacteria growing in more amino

  14. Microaerophilic degradation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) by three Rhodococcus strains.

    Science.gov (United States)

    Fuller, M E; Perreault, N; Hawari, J

    2010-09-01

    The goal of this study was to compare the degradation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) by three Rhodococcus strains under anaerobic, microaerophilic (RDX as the sole nitrogen source. RDX and RDX metabolite concentrations were measured over time. Under microaerophilic conditions, the bacteria degraded RDX, albeit about 60-fold slower than under fully aerobic conditions. Only the breakdown product, 4-nitro-2,4-diazabutanal (NDAB) accumulated to measurable concentrations under microaerophilic conditions. RDX degraded quickly under both aerated and static aerobic conditions (DO allowed to drop below 1 mg l(-1)) with the accumulation of both NDAB and methylenedinitramine (MEDINA). No RDX degradation was observed under strict anaerobic conditions. The Rhodococcus strains did not degrade RDX under strict anaerobic conditions, while slow degradation was observed under microaerophilic conditions. The RDX metabolite NDAB was detected under both microaerophilic and aerobic conditions, while MEDINA was detected only under aerobic conditions. IMPACT AND SIGNIFICANCE OF THE STUDY: This work confirmed the production of MEDINA under aerobic conditions, which has not been previously associated with aerobic RDX degradation by these organisms. More importantly, it demonstrated that aerobic rhodococci are able to degrade RDX under a broader range of oxygen concentrations than previously reported.

  15. Involvement of two latex-clearing proteins during rubber degradation and insights into the subsequent degradation pathway revealed by the genome sequence of Gordonia polyisoprenivorans strain VH2.

    Science.gov (United States)

    Hiessl, Sebastian; Schuldes, Jörg; Thürmer, Andrea; Halbsguth, Tobias; Bröker, Daniel; Angelov, Angel; Liebl, Wolfgang; Daniel, Rolf; Steinbüchel, Alexander

    2012-04-01

    The increasing production of synthetic and natural poly(cis-1,4-isoprene) rubber leads to huge challenges in waste management. Only a few bacteria are known to degrade rubber, and little is known about the mechanism of microbial rubber degradation. The genome of Gordonia polyisoprenivorans strain VH2, which is one of the most effective rubber-degrading bacteria, was sequenced and annotated to elucidate the degradation pathway and other features of this actinomycete. The genome consists of a circular chromosome of 5,669,805 bp and a circular plasmid of 174,494 bp with average GC contents of 67.0% and 65.7%, respectively. It contains 5,110 putative protein-coding sequences, including many candidate genes responsible for rubber degradation and other biotechnically relevant pathways. Furthermore, we detected two homologues of a latex-clearing protein, which is supposed to be a key enzyme in rubber degradation. The deletion of these two genes for the first time revealed clear evidence that latex-clearing protein is essential for the microbial utilization of rubber. Based on the genome sequence, we predict a pathway for the microbial degradation of rubber which is supported by previous and current data on transposon mutagenesis, deletion mutants, applied comparative genomics, and literature search.

  16. Antimicrobial potential of Ricinus communis leaf extracts in different solvents against pathogenic bacterial and fungal strains

    Institute of Scientific and Technical Information of China (English)

    Rabia Naz; Asghari Bano

    2012-01-01

    Objective: To investigate the in vitro antimicrobial activities of the leaf extract in different solvents viz., methanol, ethanol and water extracts of the selected plant Ricinus communis. Methods:Agar well diffusion method and agar tube dilution method were carried out to perform the antibacterial and antifungal activity of methanol, ethanol and aqueous extracts. Results:Methanol leaf extracts were found to be more active against Gram positive bacteria (Bacillus subtilis: ATCC 6059 and Staphylococcus aureus: ATCC 6538) as well as Gram negative bacteria (Pseudomonas aeruginosa: ATCC 7221 and Klebsiella pneumoniae) than ethanol and aqueous leaf extracts. Antifungal activity of methanol and aqueous leaf extracts were also carried out against selected fungal strains as Aspergillus fumigatus and Aspergillus flavus. Methanolic as well as aqueous leaf extracts of Ricinus communis were effective in inhibiting the fungal growth. Conclusions: The efficient antibacterial and antifungal activity of Ricinus communis from the present investigation revealed that the methanol leaf extracts of the selected plant have significant potential to inhibit the growth of pathogenic bacterial and fungal strains than ethanol and aqueous leaf extracts.

  17. Lactobacillus rhamnosus GG-supplemented formula expands butyrate-producing bacterial strains in food allergic infants

    Science.gov (United States)

    Berni Canani, Roberto; Sangwan, Naseer; Stefka, Andrew T; Nocerino, Rita; Paparo, Lorella; Aitoro, Rosita; Calignano, Antonio; Khan, Aly A; Gilbert, Jack A; Nagler, Cathryn R

    2016-01-01

    Dietary intervention with extensively hydrolyzed casein formula supplemented with Lactobacillus rhamnosus GG (EHCF+LGG) accelerates tolerance acquisition in infants with cow's milk allergy (CMA). We examined whether this effect is attributable, at least in part, to an influence on the gut microbiota. Fecal samples from healthy controls (n=20) and from CMA infants (n=19) before and after treatment with EHCF with (n=12) and without (n=7) supplementation with LGG were compared by 16S rRNA-based operational taxonomic unit clustering and oligotyping. Differential feature selection and generalized linear model fitting revealed that the CMA infants have a diverse gut microbial community structure dominated by Lachnospiraceae (20.5±9.7%) and Ruminococcaceae (16.2±9.1%). Blautia, Roseburia and Coprococcus were significantly enriched following treatment with EHCF and LGG, but only one genus, Oscillospira, was significantly different between infants that became tolerant and those that remained allergic. However, most tolerant infants showed a significant increase in fecal butyrate levels, and those taxa that were significantly enriched in these samples, Blautia and Roseburia, exhibited specific strain-level demarcations between tolerant and allergic infants. Our data suggest that EHCF+LGG promotes tolerance in infants with CMA, in part, by influencing the strain-level bacterial community structure of the infant gut. PMID:26394008

  18. Lactobacillus rhamnosus GG-supplemented formula expands butyrate-producing bacterial strains in food allergic infants.

    Science.gov (United States)

    Berni Canani, Roberto; Sangwan, Naseer; Stefka, Andrew T; Nocerino, Rita; Paparo, Lorella; Aitoro, Rosita; Calignano, Antonio; Khan, Aly A; Gilbert, Jack A; Nagler, Cathryn R

    2016-03-01

    Dietary intervention with extensively hydrolyzed casein formula supplemented with Lactobacillus rhamnosus GG (EHCF+LGG) accelerates tolerance acquisition in infants with cow's milk allergy (CMA). We examined whether this effect is attributable, at least in part, to an influence on the gut microbiota. Fecal samples from healthy controls (n=20) and from CMA infants (n=19) before and after treatment with EHCF with (n=12) and without (n=7) supplementation with LGG were compared by 16S rRNA-based operational taxonomic unit clustering and oligotyping. Differential feature selection and generalized linear model fitting revealed that the CMA infants have a diverse gut microbial community structure dominated by Lachnospiraceae (20.5±9.7%) and Ruminococcaceae (16.2±9.1%). Blautia, Roseburia and Coprococcus were significantly enriched following treatment with EHCF and LGG, but only one genus, Oscillospira, was significantly different between infants that became tolerant and those that remained allergic. However, most tolerant infants showed a significant increase in fecal butyrate levels, and those taxa that were significantly enriched in these samples, Blautia and Roseburia, exhibited specific strain-level demarcations between tolerant and allergic infants. Our data suggest that EHCF+LGG promotes tolerance in infants with CMA, in part, by influencing the strain-level bacterial community structure of the infant gut.

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

    Science.gov (United States)

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

    2015-03-01

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

  20. Antimicrobial potential of Ricinus communis leaf extracts in different solvents against pathogenic bacterial and fungal strains.

    Science.gov (United States)

    Naz, Rabia; Bano, Asghari

    2012-12-01

    To investigate the in vitro antimicrobial activities of the leaf extract in different solvents viz., methanol, ethanol and water extracts of the selected plant Ricinus communis. Agar well diffusion method and agar tube dilution method were carried out to perform the antibacterial and antifungal activity of methanol, ethanol and aqueous extracts. Methanol leaf extracts were found to be more active against Gram positive bacteria (Bacillus subtilis: ATCC 6059 and Staphylococcus aureus: ATCC 6538) as well as Gram negative bacteria (Pseudomonas aeruginosa: ATCC 7221 and Klebsiella pneumoniae) than ethanol and aqueous leaf extracts. Antifungal activity of methanol and aqueous leaf extracts were also carried out against selected fungal strains as Aspergillus fumigatus and Aspergillus flavus. Methanolic as well as aqueous leaf extracts of Ricinus communis were effective in inhibiting the fungal growth. The efficient antibacterial and antifungal activity of Ricinus communis from the present investigation revealed that the methanol leaf extracts of the selected plant have significant potential to inhibit the growth of pathogenic bacterial and fungal strains than ethanol and aqueous leaf extracts.

  1. Carbon utilization profiles of river bacterial strains facing sole carbon sources suggest metabolic interactions.

    Science.gov (United States)

    Goetghebuer, Lise; Servais, Pierre; George, Isabelle F

    2017-05-01

    Microbial communities play a key role in water self-purification. They are primary drivers of biogenic element cycles and ecosystem processes. However, these communities remain largely uncharacterized. In order to understand the diversity-heterotrophic activity relationship facing sole carbon sources, we assembled a synthetic community composed of 20 'typical' freshwater bacterial species mainly isolated from the Zenne River (Belgium). The carbon source utilization profiles of each individual strain and of the mixed community were measured in Biolog Phenotype MicroArrays PM1 and PM2A microplates that allowed testing 190 different carbon sources. Our results strongly suggest interactions occurring between our planktonic strains as our synthetic community showed metabolic properties that were not displayed by its single components. Finally, the catabolic performances of the synthetic community and a natural community from the same sampling site were compared. The synthetic community behaved like the natural one and was therefore representative of the latter in regard to carbon source consumption. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Sphingomonas taxi, Isolated from Cucurbita pepo, Proves to Be a DDE-Degrading and Plant Growth-Promoting Strain.

    Science.gov (United States)

    Eevers, Nele; Van Hamme, Jonathan D; Bottos, Eric M; Weyens, Nele; Vangronsveld, Jaco

    2015-05-14

    The draft genome of Sphingomonas taxi, a strain of the Sphingomonadaceae isolated from Cucurbita pepo root tissue, is presented. This Gram-negative bacterium shows 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene (DDE)-degrading potential and plant growth-promoting capacities. An analysis of its 3.9-Mb draft genome will enhance the understanding of DDE-degradation pathways and phytoremediation applications for DDE-contaminated soils. Copyright © 2015 Eevers et al.

  3. Production of keratinolytic enzyme by an indigenous feather-degrading strain Bacillus cereus Wu2.

    Science.gov (United States)

    Lo, Wei-Hsun; Too, Jui-Rze; Wu, Jane-Yii

    2012-12-01

    A novel feather-degrading microorganism was isolated from a poultry farm in Taiwan, and was identified Bacillus cereus Wu2 according to 16S rRNA sequencing. The isolated strain produces keratinolytic enzyme using chicken feather as the sole carbon and nitrogen source. The experimental results indicated that the extra carbon sources (glucose, fructose, starch, sucrose, or lactose) could act as a catabolite repressor to the enzyme secretion or keratinolytic activity when keratinous substrates were employed as protein sources. However, addition of 2 g/L of NH(4)Cl to the feather medium increased the enzyme production. The optimum temperature and initial pH for enzyme production were 30°C and 7.0, respectively. The maximum yield of the enzyme was 1.75 kU/mL in the optimal chicken feather medium; this value was about 17-fold higher than the yield in the basal hair medium. The B. cereus Wu2 possessed disulfide reductase activity along with keratinolytic activity. The amino acid contents of feathers degradated by B. cereus Wu2 were higher, especially for lysine, methionine and threonine which were nutritionally essential amino acids and usually deficient in the feather meal. Thus, B. cereus Wu2 could be not only used to enhance the nutritional value of feather meal but is also a potential bioinoculant in agricultural environments.

  4. Screening of Lactobacillus strains of domestic goose origin against bacterial poultry pathogens for use as probiotics.

    Science.gov (United States)

    Dec, Marta; Puchalski, Andrzej; Urban-Chmiel, Renata; Wernicki, Andrzej

    2014-10-01

    Lactobacilli are natural inhabitants of human and animal mucous membranes, including the avian gastrointestinal tract. Recently, increasing attention has been given to their probiotic, health-promoting capacities, among which their antagonistic potential against pathogens plays a key role. A study was conducted to evaluate probiotic properties of Lactobacillus strains isolated from feces or cloacae of domestic geese. Among the 104 examined isolates, previously identified to the species level by whole-cell matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and analysis of 16S-23S regions of rDNA, dominated Lactobacillus salivarius (35%), followed by Lactobacillus johnsonii (18%) and Lactobacillus ingluviei (11%). All lactobacilli were screened for antimicrobial activity toward Salmonella Enteritidis, Escherichia coli, Clostridium perfringens, Staphylococcus aureus, Pasteurella multocida, and Riemerella anatipestifer using the agar slab method and the well diffusion method. Lactobacillus salivarius and Lactobacillus plantarum exhibited particularly strong antagonism toward all of the indicator strains. In the agar slab method, the highest sensitivity to Lactobacillus was observed in R. anatipestifer and P. multocida, and the lowest in E. coli and S. aureus. The ability to produce H₂O₂was exhibited by 92% of isolates, but there was no correlation between the rate of production of this reactive oxygen species and the antimicrobial activity of Lactobacillus sp. All lactobacilli showed resistance to pH 3.0 and 3.5 and to 2% bile. The data demonstrate that Lactobacillus isolates from geese may have probiotic potential in reducing bacterial infections. The antibacterial activity of the selected lactobacilli is mainly due to lactic acid production by these bacteria. The selected Lactobacillus strains that strongly inhibited the growth of pathogenic bacteria, and were also resistant to low pH and bile salts, can potentially restore the balance

  5. Rapid identification of ESKAPE bacterial strains using an autonomous microfluidic device.

    Directory of Open Access Journals (Sweden)

    Jack Y Ho

    Full Text Available This article describes Bacteria ID Chips ('BacChips': an inexpensive, portable, and autonomous microfluidic platform for identifying pathogenic strains of bacteria. BacChips consist of a set of microchambers and channels molded in the elastomeric polymer, poly(dimethylsiloxane (PDMS. Each microchamber is preloaded with mono-, di-, or trisaccharides and dried. Pressing the layer of PDMS into contact with a glass coverslip forms the device; the footprint of the device in this article is ∼6 cm(2. After assembly, BacChips are degased under large negative pressure and are stored in vacuum-sealed plastic bags. To use the device, the bag is opened, a sample containing bacteria is introduced at the inlet of the device, and the degased PDMS draws the sample into the central channel and chambers. After the liquid at the inlet is consumed, air is drawn into the BacChip via the inlet and provides a physical barrier that separates the liquid samples in adjacent microchambers. A pH indicator is admixed with the samples prior to their loading, enabling the metabolism of the dissolved saccharides in the microchambers to be visualized. Importantly, BacChips operate without external equipment or instruments. By visually detecting the growth of bacteria using ambient light after ∼4 h, we demonstrate that BacChips with ten microchambers containing different saccharides can reproducibly detect the ESKAPE panel of pathogens, including strains of: Enterococcus faecalis, Enteroccocus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter aerogenes, and Enterobacter cloacae. This article describes a BacChip for point-of-care detection of ESKAPE pathogens and a starting point for designing multiplexed assays that identify bacterial strains from clinical samples and simultaneously determine their susceptibility to antibiotics.

  6. Production of 6-phenylacetylene picolinic acid from diphenylacetylene by a toluene-degrading Acinetobacter strain.

    Science.gov (United States)

    Spain, Jim C; Nishino, Shirley F; Witholt, Bernard; Tan, Loon-Seng; Duetz, Wouter A

    2003-07-01

    Several strategies for using enzymes to catalyze reactions leading to the synthesis of relatively simple substituted picolinic acids have been described. The goal of the work described here was to synthesize a more complex molecule, 6-phenylacetylene picolinic acid [6-(2-phenylethynyl)pyridine-2-carboxylic acid], for use as a potential endcapping agent for aerospace polymers. We screened 139 toluene-degrading strains that use a variety of catabolic pathways for the ability to catalyze oxidative transformation of diphenylacetylene. Acinetobacter sp. strain F4 catalyzed the overall conversion of diphenylacetylene to a yellow metabolite, which was identified as a putative meta ring fission product (2-hydroxy-8-phenyl-6-oxoocta-2,4-dien-7-ynoic acid [RFP]). The activity could be sustained by addition of toluene at a flow rate determined empirically so that the transformations were sustained in spite of the fact that toluene is a competitive inhibitor of the enzymes. The overall rate of transformation was limited by the instability of RFP. The RFP was chemically converted to 6-phenylacetylene picolinic acid by treatment with ammonium hydroxide. The results show the potential for using the normal growth substrate to provide energy and to maintain induction of the enzymes involved in biotransformation during preliminary stages of biocatalyst development.

  7. Ethanedisulfonate is degraded via sulfoacetaldehyde in Ralstonia sp. strain EDS1.

    Science.gov (United States)

    Denger, K; Cook, A M

    2001-07-01

    Aerobic enrichment cultures (11) yielded three cultures able to utilise ethane-1,2-disulfonate as sole source of carbon and energy in salts medium. Two pure cultures were obtained and we worked with strain EDS1, which was assigned to the genus Ralstonia on the basis of its 16S rDNA sequence and simple taxonomic tests. Strain EDS1 utilised at least seven alkane(di)sulfonates, ethane-1,2-disulfonate, taurine, isethionate, sulfoacetate, sulfoacetaldehyde and propane-1,3-disulfonate, as well as methanesulfonate and formate. Growth with ethanedisulfonate was concomitant with substrate disappearance and the formation of 2 mol sulfate per mol substrate. The growth yield, 7 g protein (mol C)(-1), indicated quantitative utilisation of the substrate. Ethanedisulfonate-dependent oxygen uptake of whole cells during growth rose to a maximum before the end of growth and then sank rapidly; this was interpreted as evidence for an inducible desulfonative oxygenase that was not active in cell extracts. Inducible sulfoacetaldehyde sulfo-lyase was detected at high activity. Inducible degradation of taurine or isethionate or sulfoacetate via sulfoacetaldehyde sulfo-lyase is interpreted from the data.

  8. Bacterial diversity and reductive dehalogenase redundancy in a 1,2-dichloroethane-degrading bacterial consortium enriched from a contaminated aquifer

    Directory of Open Access Journals (Sweden)

    Wittebolle Lieven

    2010-02-01

    Full Text Available Abstract Background Bacteria possess a reservoir of metabolic functionalities ready to be exploited for multiple purposes. The use of microorganisms to clean up xenobiotics from polluted ecosystems (e.g. soil and water represents an eco-sustainable and powerful alternative to traditional remediation processes. Recent developments in molecular-biology-based techniques have led to rapid and accurate strategies for monitoring and identification of bacteria and catabolic genes involved in the degradation of xenobiotics, key processes to follow up the activities in situ. Results We report the characterization of the response of an enriched bacterial community of a 1,2-dichloroethane (1,2-DCA contaminated aquifer to the spiking with 5 mM lactate as electron donor in microcosm studies. After 15 days of incubation, the microbial community structure was analyzed. The bacterial 16S rRNA gene clone library showed that the most represented phylogenetic group within the consortium was affiliated with the phylum Firmicutes. Among them, known degraders of chlorinated compounds were identified. A reductive dehalogenase genes clone library showed that the community held four phylogenetically-distinct catalytic enzymes, all conserving signature residues previously shown to be linked to 1,2-DCA dehalogenation. Conclusions The overall data indicate that the enriched bacterial consortium shares the metabolic functionality between different members of the microbial community and is characterized by a high functional redundancy. These are fundamental features for the maintenance of the community's functionality, especially under stress conditions and suggest the feasibility of a bioremediation treatment with a potential prompt dehalogenation and a process stability over time.

  9. Screening of the effective cellulose-degradable strain and its application in the production of cellulose bioethanol

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Strains from the cellulose-containing environment were collected. Primary screening(by filter-paper Hutchison solid culture medium and sodium carboxymethylcellulose solid culture medium) and reelection(by filter-paper inorganic salt culture medium and sodium carboxymethylcellulose Congo red culture medium) indicated that five strains obtained were best suited for high performance cellulose degradation. Determination of sodium carboxymethylcellulose activity(CMCA) and filter paper activity(FPA) was accomplis...

  10. Screening a Strain of Aspergillus niger and Optimization of Fermentation Conditions for Degradation of Aflatoxin B1

    OpenAIRE

    Wei Zhang; Beibei Xue; Mengmeng Li; Yang Mu; Zhihui Chen; Jianping Li; Anshan Shan

    2014-01-01

    Aflatoxin B1, a type of highly toxic mycotoxin produced by some species belonging to the Aspergillus genus, such as Aspergillus flavus and Aspergillus parasiticus, is widely distributed in feed matrices. Here, coumarin was used as the sole carbon source to screen microorganism strains that were isolated from types of feed ingredients. Only one isolate (ND-1) was able to degrade aflatoxin B1 after screening. ND-1 isolate, identified as a strain of Aspergillus niger using phylogenetic analysis ...

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

    Directory of Open Access Journals (Sweden)

    K. Diop

    2016-07-01

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

  12. Isolation and Partial Characterization of Bacterial Strains on Low Organic Carbon Medium from Soils Fertilized with Different Organic Amendments

    NARCIS (Netherlands)

    Senechkin, I.V.; Speksnijder, A.G.C.L.; Semenov, A.M.; Bruggen, van A.H.C.; Overbeek, van L.S.

    2010-01-01

    A total of 720 bacterial strains were isolated from soils with four different organic amendment regimes on a low organic carbon (low-C) agar medium (10 mu g C ml(-1)) traditionally used for isolation of oligotrophs. Organic amendments in combination with field history resulted in differences in diss

  13. Interaction of mouse splenocytes and macrophages with bacterial strains in vitro : the effect of age in the immune response

    NARCIS (Netherlands)

    Van Beek, A. A.; Hoogerland, J. A.; Belzer, C.; De Vos, P.; De Vos, W. M.; Savelkoul, H. F. J.; Leenen, P. J. M.

    2016-01-01

    Probiotics influence the immune system, both at the local and systemic level. Recent findings suggest the relation between microbiota and the immune system alters with age. Our objective was to address direct effects of six bacterial strains on immune cells from young and aged mice: Lactobacillus pl

  14. Interaction of mouse splenocytes and macrophages with bacterial strains in vitro: the effect of age in the immune response

    NARCIS (Netherlands)

    Beek, van A.A.; Hoogerland, Joanne; Belzer, C.; Vos, de P.; Vos, de W.M.; Savelkoul, H.F.J.; Leenen, P.J.

    2016-01-01

    Probiotics influence the immune system, both at the local and systemic level. Recent findings suggest the relation between microbiota and the immune system alters with age. Our objective was to address direct effects of six bacterial strains on immune cells from young and aged mice: Lactobacillus pl

  15. ‘Lascolabacter vaginalis’ strain KHD1, a new bacterial species cultivated from human female genital tract

    Directory of Open Access Journals (Sweden)

    K. Diop

    2016-09-01

    Full Text Available We present the major characteristics of ‘Lascolabacter vaginalis’ strain KHD1 (= CSUR P0109 = DSM 101752, a new member of the family Prevotellaceae that was cultivated from a vaginal sample of a 33-year-old woman with bacterial vaginosis.

  16. An approach to biodegradation of chlorobenzenes: combination of Typha angustifolia and bacterial effects on hexachlorobenzene degradation in water.

    Science.gov (United States)

    Wang, Bei; Zhang, Cuiping; Li, Shuying; Lu, Guangqiu; Lu, Guoli; Li, Song; Zhou, Yuanqing

    2016-09-01

    Although rhizoremediation is an effective approach to remove organic pollutants from the environment, little is known about the mechanism of hexachlorobenzene (HCB) biodegradation in water. In this study, we used Typha angustifolia (T. angustifolia) grown in sterile Hoagland nutrient solution to determine the rhizosphere effects on the ability of bacteria in water to reduce HCB levels. The results revealed that T. angustifolia could facilitate HCB degradation and that the initial HCB concentration was the major factor responsible for HCB degradation in nutrient solution. Furthermore, HCB biodegradation in low-HCB nutrient solution with T. angustifolia fitted the first-order kinetics, owing to the high concentration of total organic carbon, low HCB toxicity, and unique bacterial community in the T. angustifolia rhizosphere. Denaturing gradient gel electrophoresis indicated that the rhizosphere effects and different dosages of HCB have significant effects on the bacterial communities by repressing and favoring certain populations. The most successful bacteria to adapt to HCB contamination was Bacillus sp., while the dominant bacterial phyla in HCB-polluted water were Proteobacteria and Firmicutes.

  17. 16S ribosomal DNA clone libraries to reveal bacterial diversity in anaerobic reactor-degraded tetrabromobisphenol A.

    Science.gov (United States)

    Peng, Xingxing; Zhang, Zaili; Zhao, Ziling; Jia, Xiaoshan

    2012-05-01

    Microorganisms able to rapidly degrade tetrabromobisphenol A (TBBPA) were domesticated in an anaerobic reactor and added to gradually increased concentrations of TBBPA. After 240 days of domestication, the degradation rate reached 96.0% in cultivated batch experiments lasting 20 days. The optimum cultivating temperature and pH were 30°C and 7.0. The bacterial community's composition and diversity in the reactor was studied by comparative analysis with 16S ribosomal DNA clone libraries. Amplified rDNA restriction analysis of 200 clones from the library indicate that the rDNA richness was high (Coverage C 99.5%) and that evenness was not high (Shannon-Weaver index 2.42). Phylogenetic analysis of 63 bacterial sequences from the reactor libraries demonstrated the presence of Betaproteobacteria (33.1%), Gammaproteobacteria (18.7%), Bacteroidetes (13.9%), Firmicutes (11.4%), Chloroflexi (3.6%), Actinobacteria (0.6%), the candidate division TM7 (4.2%) and other unknown, uncultured bacterial groups (14.5%). Comamonas, Achromobacter, Pseudomonas and Flavobacterium were the dominant types.

  18. Metabolic network analysis of an adipoyl-7-ADCA-producing strain of Penicillium chrysogenum: Elucidation of adipate degradation

    DEFF Research Database (Denmark)

    Thykær, Jette; Christensen, Bjarke; Nielsen, Jens

    2002-01-01

    An adipoyl-7-ADCA-producing, recombinant strain of Penicillium chrysogenum was characterized by metabolic network analysis, with special focus on the degradation of adipate and determination of the metabolic fluxes. Degradation of the side-chain precursor, adipate, causes an undesired consumption...... and the formed acetyl-CoA was metabolized in the glyoxylate shunt. This hypothesis was further substantiated by an enzyme assay, which showed activity of the key enzyme in the glyoxylate shunt. Flux estimations in two chemostat cultures, one with and one without adipate in the feed, revealed that degradation...... of adipate in the production of 7-ADCA. Using C-13-labeled glucose and measurement of metabolite labeling patterns, it was shown that adipate was degraded by beta-oxidation to succinyl-CoA and acetyl-CoA. The labeling analysis indicated that degradation of adipate was taking place in the microbodies...

  19. Aflatoxin B1 degradation during co-cultivation of Aspergillus flavus and Pleurotus ostreatus strains on rice straw.

    Science.gov (United States)

    Das, Arijit; Bhattacharya, Sourav; Palaniswamy, Muthusamy; Angayarkanni, Jayaraman

    2015-06-01

    Aflatoxin B1 (AFB1) produced by Aspergillus flavus is known to have carcinogenic and teratogenic effects on animal health. Accidental feeding of AFB1-contaminated rice straw may be detrimental to dairy cattle. White-rot basidiomycetous fungus Pleurotus ostreatus can grow on different agronomic wastes by synthesizing different ligninolytic enzymes. These extracellular enzymes are capable of degrading many environmentally hazardous compounds including AFB1. The present study examines the ability of different strains of P. ostreatus to degrade AFB1 in contaminated rice straw. Different strains of A. flavus were inoculated on rice straw for AFB1 production. The moldy straw was then subjected to co-cultivation by different strains of P. ostreatus. The extent of AFB1 degradation was determined by high performance liquid chromatography. Results indicated the presence of AFB1 in the moldy straw samples at levels of 27.95 ± 0.23 and 21.26 ± 0.55 µg/g of dry substrate for A. flavus MTCC 2798 and A. flavus GHBF09, respectively. Co-cultivation of P. ostreatus strains on AFB1-contaminated rice straw revealed their ability to rapidly colonize the substrate by profuse hyphal ramification. Highest degradation of AFB1 (89.41 %) was recorded in the straw containing co-cultures of A. flavus MTCC 2798 and P. ostreatus GHBBF10. Natural isolate P. ostreatus GHBBF10 demonstrated higher AFB1-degradation potential than P.ostreatus MTCC 142. This basidiomycete strain can be further exploited to effectively degrade moderate concentrations of AFB1 in contaminated moldy rice straw.

  20. Genome analysis of crude oil degrading Franconibacter pulveris strain DJ34 revealed its genetic basis for hydrocarbon degradation and survival in oil contaminated environment.

    Science.gov (United States)

    Pal, Siddhartha; Kundu, Anirban; Banerjee, Tirtha Das; Mohapatra, Balaram; Roy, Ajoy; Manna, Riddha; Sar, Pinaki; Kazy, Sufia K

    2017-06-15

    Franconibacter pulveris strain DJ34, isolated from Duliajan oil fields, Assam, was characterized in terms of its taxonomic, metabolic and genomic properties. The bacterium showed utilization of diverse petroleum hydrocarbons and electron acceptors, metal resistance, and biosurfactant production. The genome (4,856,096bp) of this strain contained different genes related to the degradation of various petroleum hydrocarbons, metal transport and resistance, dissimilatory nitrate, nitrite and sulfite reduction, chemotaxy, biosurfactant synthesis, etc. Genomic comparison with other Franconibacter spp. revealed higher abundance of genes for cell motility, lipid transport and metabolism, transcription and translation in DJ34 genome. Detailed COG analysis provides deeper insights into the genomic potential of this organism for degradation and survival in oil-contaminated complex habitat. This is the first report on ecophysiology and genomic inventory of Franconibacter sp. inhabiting crude oil rich environment, which might be useful for designing the strategy for bioremediation of oil contaminated environment. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Degradation of 2,6-di-tert-butylphenol by an isolated high-efficiency bacterium strain.

    Science.gov (United States)

    Zhang, Ya-lei; Fang, Zhen-wei; Xu, De-qiang; Xiao, Yi-ping; Zhao, Jian-fu; Qiang, Zhi-min

    2005-01-01

    An aerobic bacterium strain, F-3-4, capable of effectively degrading 2, 6-ditert-butylphenol (2, 6-DTBP), was isolated and screened out from an acrylic fiber wastewater and the biofilm in the wastewater treatment facilities. This strain was identified as Alcaligenes sp. through morphological, physiological and biochemical examinations. After cultivation, the strain was enhanced by 26.3% in its degradation capacity for 2,6-DTBP. Results indicated that the strain was able to utilize 2,6-DTBP, lysine, lactamine, citrate, n-utenedioic acid and malic acid as the sole carbon and energy source, alkalinize acetamide, asparagine, L-histidine, acetate, citrate and propionate, but failed to utilize glucose, D-fructose, D-seminose, D-xylose, serine and phenylalanine as the sole carbon and energy source. The optimal growth conditions were determined to be: temperature 37 degrees C, pH 7.0, inoculum size 0.1% and shaker rotary speed 250 r/min. Under the optimal conditions, the degradation kinetics of 2,6-DTBP with an initial concentration of 100 mg/L was studied. Results indicated that 62.4% of 2,6-DTBP was removed after 11 d. The degradation kinetics could be expressed by Eckenfelder equation with a half life of 9.38 d. In addition, the initial concentration of 2,6-DTBP played an important role on the degradation ability of the strain. The maximum initial concentration of 2,6-DTBP was determined to be 200 mg/L. Above this level, the strain was overloaded and exhibited significant inhibition.

  2. Degradation of 2,6-di-tert-butylphenol by an isolated high-efficiency bacterium strain

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ya-lei; FANG Zhen-wei; XU De-qiang; XIAO Yi-ping; ZHAO Jian-fu; QIANG Zhi-min

    2005-01-01

    An aerobic bacterium strain, F-3-4, capable of effectively degrading 2,6-di-tert-butylphenol (2, 6-DTBP), was isolated and screened out from an acrylic fiber wastewater and the biofilm in the wastewater treatment facilities. This strain was identified as Alcaligenes sp. through morphological, physiological and biochemical examinations. After cultivation, the strain was enhanced by 26.3% in its degradation capacity for 2,6-DTBP. Results indicated that the strain was able to utilize 2,6-DTBP, lysine, lactamine, citrate, n-utenedioic acid and maiic acid as the sole carbon and energy source, alkalinize acetamide, asparagine, L-histidine, acetate, citrate and propionate,but failed to utilize glucose, D-fructose, D-seminose, D-xylose, serine and phenylalanine as the sole carbon and energy source. The optimal growth conditions were determined to be: temperature 37 ℃, pH 7.0, inoculum size 0.1% and shaker rotary speed 250 r/min.Under the optimal conditions, the degradation kinetics of 2,6-DTBP with an initial concentration of 100 mg/L was studied. Results indicated that 62.4% of 2,6-DTBP was removed after 11 d. The degradation kinetics could be expressed by Eckenfelder equation with a half life of 9.38 d. In addition, the initial concentration of 2,6-DTBP played an important role on the degradation ability of the strain. The maximum initial concentration of 2,6-DTBP was determined to be 200 mg/L. Above this level, the strain was overloaded and exhibited significant inhibition.

  3. Identification of polymorphic tandem repeats by direct comparison of genome sequence from different bacterial strains : a web-based resource

    Directory of Open Access Journals (Sweden)

    Vergnaud Gilles

    2004-01-01

    Full Text Available Abstract Background Polymorphic tandem repeat typing is a new generic technology which has been proved to be very efficient for bacterial pathogens such as B. anthracis, M. tuberculosis, P. aeruginosa, L. pneumophila, Y. pestis. The previously developed tandem repeats database takes advantage of the release of genome sequence data for a growing number of bacteria to facilitate the identification of tandem repeats. The development of an assay then requires the evaluation of tandem repeat polymorphism on well-selected sets of isolates. In the case of major human pathogens, such as S. aureus, more than one strain is being sequenced, so that tandem repeats most likely to be polymorphic can now be selected in silico based on genome sequence comparison. Results In addition to the previously described general Tandem Repeats Database, we have developed a tool to automatically identify tandem repeats of a different length in the genome sequence of two (or more closely related bacterial strains. Genome comparisons are pre-computed. The results of the comparisons are parsed in a database, which can be conveniently queried over the internet according to criteria of practical value, including repeat unit length, predicted size difference, etc. Comparisons are available for 16 bacterial species, and the orthopox viruses, including the variola virus and three of its close neighbors. Conclusions We are presenting an internet-based resource to help develop and perform tandem repeats based bacterial strain typing. The tools accessible at http://minisatellites.u-psud.fr now comprise four parts. The Tandem Repeats Database enables the identification of tandem repeats across entire genomes. The Strain Comparison Page identifies tandem repeats differing between different genome sequences from the same species. The "Blast in the Tandem Repeats Database" facilitates the search for a known tandem repeat and the prediction of amplification product sizes. The "Bacterial

  4. The function of a toluene-degrading bacterial community in a waste gas trickling filter

    DEFF Research Database (Denmark)

    Pedersen, A.R.; Arvin, E.

    1999-01-01

    oligonucleotide 16S ribosomal RNA probe targeting the toluene-degrading species Pseudomonas putida, and by computer simulations (AQUASIM) of the biofilm growth based on a food web model. Biofilms were taken from a lab-scale trickling filter for treatment of toluene-polluted air. The biofilm growth......The function of a community of toluene-degrading bacteria in a biofilm system was investigated with regard to growth and toluene degradation in order to investigate substrate interactions in the community. This was done by the combination of experimental observations using a specific...... and the activity of P. putida, a representative of the toluene-degrading species in the biofilm which have been described previously (Pedersen et al., 1997) were simulated. The simulation indicated that the volume fraction of the toluene degraders in the biofilm decreased from 12% to only 2% (11% of dry weight...

  5. Enhancing the Decolorizing and Degradation Ability of Bacterial Consortium Isolated from Textile Effluent Affected Area and Its Application on Seed Germination

    Directory of Open Access Journals (Sweden)

    Rashid Mahmood

    2015-01-01

    Full Text Available A bacterial consortium BMP1/SDSC/01 consisting of six isolates was isolated from textile effected soil, sludge, and textile effluent from Hudiara drain near Nishat Mills Limited, Ferozepur Road, Lahore, Pakistan. It was selected because of being capable of degrading and detoxifying red, green, black, and yellow textile dyes. The pH and supplements were optimized to enhance the decolorization ability of the selected consortium. The results indicated that decolorizing ability of consortium for the red, green, black, and yellow dyes was higher as compared to individual strains. The consortium was able to decolorize 84%, 84%, 85%, 85%, and 82% of 200 ppm of red, green, black, yellow, and mixed dyes within 24 h while individual strain required 72 h. On supplementing urea, the consortium decolorized 87, 86, 89, 86, and 83%, respectively, while on supplementing sodium chloride the consortium decolorized 93, 94, 93, 94, and 89% of red, green, black, yellow, and mixed dyes, respectively, which was maximum while in the presence of ascorbic acid and ammonium chloride it showed intermediate results. The effect of untreated and treated dyes was investigated on Zea mays L. (maize and Sorghum vulgare Pers. (sorghum. This study will help to promote an efficient biotreatment of textile effluents.

  6. A diverse bacterial community in an anoxic quinoline-degrading bioreactor determined by using pyrosequencing and clone library analysis.

    Science.gov (United States)

    Zhang, Xiaojun; Yue, Siqing; Zhong, Huihui; Hua, Weiying; Chen, Ruijia; Cao, Youfang; Zhao, Liping

    2011-07-01

    There is a concern of whether the structure and diversity of a microbial community can be effectively revealed by short-length pyrosequencing reads. In this study, we performed a microbial community analysis on a sample from a high-efficiency denitrifying quinoline-degrading bioreactor and compared the results generated by pyrosequencing with those generated by clone library technology. By both technologies, 16S rRNA gene analysis indicated that the bacteria in the sample were closely related to, for example, Proteobacteria, Actinobacteria, and Bacteroidetes. The sequences belonging to Rhodococcus were the most predominant, and Pseudomonas, Sphingomonas, Acidovorax, and Zoogloea were also abundant. Both methods revealed a similar overall bacterial community structure. However, the 622 pyrosequencing reads of the hypervariable V3 region of the 16S rRNA gene revealed much higher bacterial diversity than the 130 sequences from the full-length 16S rRNA gene clone library. The 92 operational taxonomic unit (OTUs) detected using pyrosequencing belonged to 45 families, whereas the 37 OTUs found in the clone library belonged to 25 families. Most sequences obtained from the clone library had equivalents in the pyrosequencing reads. However, 64 OTUs detected by pyrosequencing were not represented in the clone library. Our results demonstrate that pyrosequencing of the V3 region of the 16S rRNA gene is not only a powerful tool for discovering low-abundance bacterial populations but is also reliable for dissecting the bacterial community structure in a wastewater environment.

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

    DEFF Research Database (Denmark)

    Pedersen, Annette; Nybroe, Ole; Winding, Anne;

    2009-01-01

    selective feeding flagellate Cercomonas longicauda versus the non-selective feeding nematode Caenorhabditis elegans) influence the abundance of two bacteria that compete for resources in simple model communities. Microcosms consisted of either one gfp-tagged bacterial strain (Pseudomonas fluorescens DSM......50090 or one of two biocontrol strains P. fluorescens CHA0 or Pseudomonas sp. DSS73) or combinations of two bacterial strains. DSM50090 is a suitable food bacterium, DSS73 is of intermediate food quality, and CHA0 is inedible to the bacterial feeders. Bacterial and protozoan cell numbers were measured......How bacterial feeding fauna affects colonization and survival of bacteria in soil is not well understood, which constrains the applicability of bacterial inoculants in agriculture. This study aimed to unravel how food quality of bacteria and bacterial feeders with different feeding habits (the...

  8. Resorcinol degradation by a Penicillium chrysogenum strain under osmotic stress: mono and binary substrate matrices with phenol.

    Science.gov (United States)

    Guedes, Sumaya Ferreira; Mendes, Benilde; Leitão, Ana Lúcia

    2011-04-01

    A phenol-degrading Penicillium chrysogenum strain previously isolated from a salt mine was able to grow at 1,000 mg l(-1) of resorcinol on solid medium. The aerobic degradation of resorcinol by P. chrysogenum CLONA2 was studied in batch cultures in minimal mineral medium with 58.5 g l(-1) of sodium chloride using resorcinol as the sole carbon source. The fungal strain showed the ability to degrade up to 250 mg l(-1) of resorcinol. Resorcinol and phenol efficiency degradation by P. chrysogenum CLONA2 was compared. This strain removes phenol faster than resorcinol. When phenol and resorcinol were in binary substrate matrices, phenol enhanced resorcinol degradation, and organic load decreased with respect to the mono substrate matrices. The acute toxicity of phenol and resorcinol, individually and in combination, to Artemia franciscana larvae has been verified before and after the bioremediation process with P. chrysogenum CLONA2. The remediation process was effective in mono and binary substrate systems.

  9. Analysis of Two Gene Clusters Involved in the Degradation of 4-Fluorophenol by Arthrobacter sp Strain IF1

    NARCIS (Netherlands)

    Ferreira, Maria Isabel M.; Iida, Toshiya; Hasan, Syed A.; Nakamura, Kaoru; Fraaije, Marco W.; Janssen, Dick B.; Kudo, Toshiaki

    2009-01-01

    Arthrobacter sp. strain IF1 is able to grow on 4-fluorophenol (4-FP) as a sole source of carbon and energy. To clone the 4-FP degradation genes, DNA libraries were constructed and screened with a probe obtained by PCR using primers designed on the basis of conserved regions of aromatic two-component

  10. Complete Genome Sequence of Raoultella ornithinolytica Strain S12, a Lignin-Degrading Bacterium Isolated from Forest Soil.

    Science.gov (United States)

    Bao, Wenying; Zhou, Yun; Jiang, Jingwei; Xu, Zhihui; Hou, Liyuan; Leung, Frederick Chi-Ching

    2015-03-19

    We report the complete genome sequence of Raoultella ornithinolytica strain S12, isolated from a soil sample collected from areas bordering rotten wood and wet soil on Mt. Zijin, Nanjing. The complete genome of this bacterium may contribute toward the discovery of efficient lignin-degrading pathways.

  11. Test of aerobic TCE degradation by willows (Salix viminalis) and willows inoculated with TCE-cometabolizing strains of Burkholderia cepacia

    DEFF Research Database (Denmark)

    Clausen, Lauge Peter Westergaard; Broholm, Mette Martina; Gosewinkel, Ulrich Bay

    2017-01-01

    Trichloroethylene (TCE) is a widespread soil and groundwater pollutant and clean-up is often problematic and expensive. Phytoremediation may be a cost-effective solution at some sites. This study investigates TCE degradation by willows (S. viminalis) and willows inoculated with three strains of B...

  12. Effects of the antibiotic ciprofloxacin on the bacterial community structure and degradation of pyrene in marine sediment

    Energy Technology Data Exchange (ETDEWEB)

    Naeslund, Johan [Department of Systems Ecology, Stockholm University, 106 91 Stockholm (Sweden)], E-mail: johan@ecology.su.se; Hedman, Jenny E.; Agestrand, Cecilia [Department of Systems Ecology, Stockholm University, 106 91 Stockholm (Sweden)

    2008-11-21

    The ecological consequences of antibiotics in the aquatic environment have been an issue of concern over the past years due to the potential risk for negative effects on indigenous microorganisms. Microorganisms provide important ecosystem services, such as nutrient recycling, organic matter mineralization and degradation of pollutants. In this study, effects of exposure to the antibiotic ciprofloxacin on the bacterial diversity and pollutant degradation in natural marine sediments were studied using molecular methods (T-RFLP) in combination with radiorespirometry. In a microcosm experiment, sediment spiked with {sup 14}C-labelled pyrene was exposed to five concentrations of ciprofloxacin (0, 20, 200, 1000 and 2000 {mu}g L{sup -1}) in a single dose to the overlying water. The production of {sup 14}CO{sub 2} (i.e. complete mineralization of pyrene) was measured during 11 weeks. Sediment samples for bacterial community structure analysis were taken after 7 weeks. Results showed a significant dose-dependent inhibition of pyrene mineralization measured as the total {sup 14}CO{sub 2} production. The nominal EC{sub 50} was calculated to 560 {mu}g L{sup -1}, corresponding to 0.4 {mu}g/kg d.w. sediment. The lowest effect concentration on the bacterial community structure was 200 {mu}g L{sup -1}, which corresponds to 0.1 {mu}g/kg d.w. sediment. Our results show that antibiotic pollution can be a potential threat to both bacterial diversity and an essential ecosystem service they perform in marine sediment.

  13. Isolation of marine polycyclic aromatic hydrocarbon (PAH)-degrading Cycloclasticus strains from the Gulf of Mexico and comparison of their PAH degradation ability with that of Puget Sound Cycloclasticus strains

    Energy Technology Data Exchange (ETDEWEB)

    Geiselbrecht, A.D.; Hedlund, B.P.; Tichi, M.A.; Staley, J.T. [Univ. of Washington, Seattle, WA (United States). Dept. of Microbiology

    1998-12-01

    Phenanthrene- and naphthalene-degrading bacteria were isolated from four offshore and nearshore locations in the Gulf of Mexico by using a modified most-probable-number technique. The concentrations of these bacteria ranged from 10{sup 2} to 10{sup 6} cells per ml of wet surficial sediment in mildly contaminated and noncontaminated sediments. A total of 23 strains of polycyclic aromatic hydrocarbon (PAH)-degrading bacteria were obtained. Based on partial 16S ribosomal DNA sequences and Phenotypic characteristics, these 23 strains are members of the genus Cycloclasticus. Three representatives were chosen for a complete phylogenetic analysis, which confirmed the close relationship of these isolates to type strain Cycloclasticus pugetii PS-1, which was isolated from Puget Sound. PAH substrate utilization tests which included high-molecular-weight PAHs revealed that these isolates had similar, broad substrate ranges which included naphthalene, substituted naphthalenes, phenanthrene, biphenyl, anthracene, acenaphthene, and fluorene. Degradation of pyrene and fluoranthene occurred only when the strains were incubated with phenanthrene. Two distinct partial PAH dioxygenase iron sulfur protein (ISP) gene sequences were PCR amplified from Puget Sound and Gulf of Mexico Cycloclasticus strains. Phylogenetic analyses of these sequences revealed that one ISP type is related to the bph type of ISP sequences, while the other ISP type is related to the nah type of ISP sequences. The predicted ISP amino acid sequences for the Gulf of Mexico and Puget Sound strains are identical, which supports the hypothesis that these geographically separated isolates are closely related phylogentically. Cycloclasticus species appear to be numerically important and widespread PAH-degrading bacteria in both Puget Sound and the Gulf of Mexico.

  14. Degradation of o-methoxybenzoate by a two-member consortium made up of a gram-positive Arthrobacter strain and a gram-negative Pantotea strain.

    Science.gov (United States)

    Gil, M; Haïdour, A; Ramos, J L

    2000-01-01

    Aromatic carboxylic acids substituted with methoxylated groups are among the most abundant products in "alpechin", the wastes resulting from pressing olives to obtain olive oil. Degradation of o-methoxybenzoate by an stable consortium made of a gram positive bacterium, Arthrobacter oxydans, and gram negative one, Pantotea agglomerans, was shown to mineralize this compound efficiently. The concerted action of both microorganisms was needed for the two first steps in the process, namely, the conversion of o-methoxybenzoate into salycilate, and the hydroxylation of the latter to gentisate. Gentisate was further degraded by the Arthrobacter strain.

  15. Effective biodegradation of 2,4,6-trinitrotoluene using a novel bacterial strain isolated from TNT-contaminated soil

    NARCIS (Netherlands)

    Gümüscü, B.; Tekinay, Turgay

    2013-01-01

    In this environmental-sample based study, rapid microbial-mediated degradation of 2,4,6-trinitrotoluene (TNT) contaminated soils is demonstrated by a novel strain, Achromobacter spanius STE 11. Complete removal of 100 mg L−1 TNT is achieved within only 20 h under aerobic conditions by the isolate. I

  16. Isolation and characterization of Klebsiella oxytoca strain degrading crude oil from a Tunisian off-shore oil field.

    Science.gov (United States)

    Chamkha, Mohamed; Trabelsi, Yosra; Mnif, Sami; Sayadi, Sami

    2011-12-01

    A facultatively anaerobic, Gram-negative, mesophilic, moderately halotolerant, non-motile, and non-sporulated bacterium, designated strain BSC5 was isolated from an off-shore "Sercina" oil field, located near the Kerkennah island, Tunisia. Yeast extract was not required for growth. Phenotypic characteristics and phylogenetic analysis of the 16S rRNA gene sequence of strain BSC5 revealed that it was related to members of the genus Klebsiella, being most closely related to the type strain of K. oxytoca (99% sequence similarity). Strain BSC5 was capable of using aerobically the crude oil as substrate growth. The growth of strain BSC5 on crude oil was followed by measuring the OD(600 nm) and by enumeration of viable cells at different culture's time. GC-MS analysis showed that strain BSC5 was capable of degrading a wide range of aliphatic hydrocarbons from C(13) to C(30) . The biodegradation rate for n -alkanes reached 44% and 75%, after 20 and 45 days of incubation, respectively. Addition of the synthetic surfactant, Tween 80, accelerated the crude oil degradation. The biodegradation rate for n -alkanes reached 61% and 98%, after 20 and 45 days of incubation, respectively. Moreover, three aromatic compounds, p -hydroxybenzoate, protocatechuate and gentisate, were metabolized completely by strain BSC5 after 24 h, under aerobic conditions.

  17. Cloning and Characterization of a Novel Agarase from a Newly Isolated Bacterium Simiduia sp. Strain TM-2 Able to Degrade Various Seaweeds.

    Science.gov (United States)

    Tawara, Mika; Sakatoku, Akihiro; Tiodjio, Rosine E; Tanaka, Daisuke; Nakamura, Shogo

    2015-10-01

    A new bacterial strain capable of reducing thalli of various seaweeds (red, green, and brown algae) was isolated from marine sediments of Uozu in Toyama Prefecture, Japan. We designated the strain Simiduia sp. TM-2 based on analyses of the 16S rRNA gene and gyrB gene sequences and its biochemical and morphological characteristics. Zymography methods revealed numerous active bands of alginate lyases, cellulases, and agarases in the cells and culture supernatants of TM-2, showing that the strain possessed multiple polysaccharide lyases. A novel agarase gene (agaTM2) was cloned from TM-2 and expressed in Escherichia coli. The resulting DNA sequence contained an open reading frame of 1764 bp that encoded a protein of 587 amino acids with an estimated molecular mass of 64 kDa and pI of 4.62. The deduced amino acid sequence, AgaTM2, had a typical signal peptide followed by a glycoside hydrolase family 16 catalytic domain and two carbohydrate-binding modules 6. A BLAST search indicated that AgaTM2 shared 75.5 % amino acid sequence identity with agarase from Simiduia agarivorans SA1. The cloned and purified AgaTM2 protein showed optimal activity at 35 °C and pH 8.0, and its thermostability increased in the presence of calcium ions. AgaTM2 degraded agarose to tetraose and hexaose.

  18. A toxaphene-degrading bacterium related to Enterobacter cloacae, strain D1 isolated from aged contaminated soil in Nicaragua.

    Science.gov (United States)

    Lacayo-Romero, Martha; Quillaguamán, Jorge; van Bavel, Bert; Mattiasson, Bo

    2005-09-01

    Enterobacter sp. strain D1 is a facultative anaerobic, Gram-negative heterotrophic bacterium isolated from toxaphene-contaminated soil. This organism was identified and characterized through phylogenetic and taxonomic studies. Based on 16S rDNA analysis, the strain D1 was clustered closely with the species Enterobacter cloacae subsp. dissolvens (LMG 2683) and E. cloacae (ATCC 13047T). Strain D1 resembled these E. cloacae strains with respect to various biochemical and nutritional characteristics, but also exhibited differences. Moreover, strain D1 is able to grow and survive with toxaphene supplied in the medium in the range 3-96 mg/L. Amongst the chemical components of toxaphene, octachlorocamphenes, nonachlorobornanes and decachlorobornanes were seen to be rapidly metabolized, although levels of hexachlorocamphenes and heptachlorobornanes were found to be slowly degraded, and subsequently accumulated during the last stage of the cultivation.

  19. Screening a Strain of Aspergillus niger and Optimization of Fermentation Conditions for Degradation of Aflatoxin B1

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2014-11-01

    Full Text Available Aflatoxin B1, a type of highly toxic mycotoxin produced by some species belonging to the Aspergillus genus, such as Aspergillus flavus and Aspergillus parasiticus, is widely distributed in feed matrices. Here, coumarin was used as the sole carbon source to screen microorganism strains that were isolated from types of feed ingredients. Only one isolate (ND-1 was able to degrade aflatoxin B1 after screening. ND-1 isolate, identified as a strain of Aspergillus niger using phylogenetic analysis on the basis of 18S rDNA, could remove 26.3% of aflatoxin B1 after 48 h of fermentation in nutrient broth (NB. Optimization of fermentation conditions for aflatoxin B1 degradation by selected Aspergillus niger was also performed. These results showed that 58.2% of aflatoxin B1 was degraded after 24 h of culture under the optimal fermentation conditions. The aflatoxin B1 degradation activity of Aspergillus niger supernatant was significantly stronger than cells and cell extracts. Furthermore, effects of temperature, heat treatment, pH, and metal ions on aflatoxin B1 degradation by the supernatant were examined. Results indicated that aflatoxin B1 degradation of Aspergillus niger is enzymatic and this process occurs in the extracellular environment.

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

    Directory of Open Access Journals (Sweden)

    Claudia Coronel-Olivares

    2013-08-01

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

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

    Science.gov (United States)

    Martínez-Hernández, Sylvia; Vázquez-Rodríguez, Gabriela A.; Beltrán-Hernández, Rosa I.; Prieto-García, Francisco; Miranda-López, José M.; Franco-Abuín, Carlos M.; Álvarez-Hernández, Alejandro; Iturbe, Ulises; Coronel-Olivares, Claudia

    2013-01-01

    The microbiological quality of water from a wastewater treatment plant that uses sodium hypochlorite as a disinfectant was assessed. Mesophilic aerobic bacteria were not removed efficiently. This fact allowed for the isolation of several bacterial strains from the effluents. Molecular identification indicated that the strains were related to Aeromonas hydrophila, Escherichia coli (three strains), Enterobacter cloacae, Kluyvera cryocrescens (three strains), Kluyvera intermedia, Citrobacter freundii (two strains), Bacillus sp. and Enterobacter sp. The first five strains, which were isolated from the non-chlorinated effluent, were used to test resistance to chlorine disinfection using three sets of variables: disinfectant concentration (8, 20 and 30 mg·L−1), contact time (0, 15 and 30 min) and water temperature (20, 25 and 30 °C). The results demonstrated that the strains have independent responses to experimental conditions and that the most efficient treatment was an 8 mg·L−1 dose of disinfectant at a temperature of 20 °C for 30 min. The other eight strains, which were isolated from the chlorinated effluent, were used to analyze inactivation kinetics using the disinfectant at a dose of 15 mg·L−1 with various retention times (0, 10, 20, 30, 60 and 90 min). The results indicated that during the inactivation process, there was no relationship between removal percentage and retention time and that the strains have no common response to the treatments. PMID:23924881

  2. Resistance and inactivation kinetics of bacterial strains isolated from the non-chlorinated and chlorinated effluents of a WWTP.

    Science.gov (United States)

    Martínez-Hernández, Sylvia; Vázquez-Rodríguez, Gabriela A; Beltrán-Hernández, Rosa I; Prieto-García, Francisco; Miranda-López, José M; Franco-Abuín, Carlos M; Álvarez-Hernández, Alejandro; Iturbe, Ulises; Coronel-Olivares, Claudia

    2013-08-06

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

  3. Selection of oleuropein-degrading lactic acid bacteria strains isolated from fermenting Moroccan green olives

    Directory of Open Access Journals (Sweden)

    Ghabbour, N.

    2011-03-01

    Full Text Available A total of 177 strains of lactic acid bacteria (LAB were isolated from early-stage Moroccan Picholine green olive fermentation, including Lactobacillus plantarum (44.63%, Lactobacillus pentosus (25.99%, Lactobacillus brevis (9.61% and Pediococcus pentosaceus (19.77%. All the isolates were screened for their tolerance to olive leaf extract and oleuropein. Most of the isolates (85.3% were found able to degrade oleuropein, when evaluated by either oleuropein or 5-Bromo- 4-chloro-3-indolyl β-D-glucuronide (X-Gluc as substrates. The biodegradation capacity of the selected strains of each species was confirmed by HPLC analysis.

    Un total de 177 cepas de bacterias ácido lácticas (LAB fueron aisladas en las primeras etapas de la fermentación de aceitunas verdes marroquíes Picholine, incluyendo Lactobacillus plantarum (44.63%, Lactobacillus pentosus (25.99%, Lactobacillus brevis (9.61% y Pediococcus pentosaceus (19.77%. Todos los aislados fueron evaluados mediante su tolerancia a extractos de hojas de olivo y oleuropeína. La mayoría de los aislados (85,3% degradaron oleuropeína, cuando fueron evaluados usando oleuropeína o 5-Bromo-4-cloro- 3-indolil β-D-glucuronido (X-Gluc como sustrato. La capacidad de biodegradación de las cepas seleccionadas para cada especie fue confirmada mediante análisis por HPLC.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

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

  5. Magnesium improves hydrogen production by a novel fermentative hydrogen-producing bacterial strain B49

    Institute of Scientific and Technical Information of China (English)

    WANG Xiang-jing; REN Nan-qi; XIANG Wen-sheng

    2005-01-01

    Batch experiments were conducted to investigate the effects of magnesium on glucose metabolism, including growth and hydrogen-producing capacity of fermentative hydrogen-producing bacterial strain B49. These abilities were enhanced with an increase in magnesium concentration. At the end of fermentation from 10 g/L ratio of ethanol amount (mg/L) to acetate amount (mg/L) was 1.1, and the accumulated hydrogen volume hydrogen volume was increased to 2 360. 5 mL H2/L culture, the ratio of ethanol amount (mg/L) to acetate amount (mg/L) was increased to 1.3 and polysaccharide was decreased to 2. 5 mg/L. Moreover, the magnesium solution addition to the medium at different fermentation times affected hydrogen-producing ability. However,the later the addition time was postponed, the less the effect was on hydrogen evolution. Further experiments confirmed the enhancement was dependent on magnesium ions and not on the other inorganic ions such as SO42- or Cl-, which constituted the magnesium salts.

  6. Composition of the bacterial community degrading Phaeocystis mucopolysaccharides in enrichment cultures

    NARCIS (Netherlands)

    Janse, Ingmar; Zwart, Gabriel; Maarel, Marc J.E.C. van der; Gottschal, Jan C.

    2000-01-01

    As described recently, mucopolysaccharides of the marine microalga Phaeocystis can be degraded in enrichment cultures. In this paper we report on the characterization of the microbial community in such enrichments. Denaturing gradient gel electrophoresis (DGGE) profiles that were obtained during

  7. Behaviour of marine oil-degrading bacterial populations in a continuous culture system

    Digital Repository Service at National Institute of Oceanography (India)

    Mohandass, C.; David, J.J.; Nair, S.; LokaBharathi, P.A.; Chandramohan, D.

    In pursuit of developing an oil-degrading microbial consortium, we used the principle of "plasmid assisted molecular breeding" (PAMB) in a continuous culture system. Three marine bacteria, Pseudomonas putida, Brevibacterium epidermidis...

  8. 耐热石油降解混合菌群的降解性能研究%Study on Degrading Performance of A Thermophilic Oil-Degrading Bacterial Group

    Institute of Scientific and Technical Information of China (English)

    李政; 赵朝成; 张云波; 刘春爽; 赵东风

    2011-01-01

    针对极端环境下石油污染土壤的生物修复,从克拉玛依油田石油污染土壤中筛选获得一组最适生长温度为45~55℃、最高耐受温度为75℃的耐热石油降解混合菌群KLO-8,该混合菌群由4株单菌组成,16S rDNA序列分析鉴定表明,其中3株为芽孢杆菌(Bacillus sp.)、1株为地芽孢杆菌(Geobacillus sp.).考察了KLO-8的降解性能,结果表明:最佳培养时间为7d;最佳氮磷比为3:1;初始pH值偏碱性更利于原油的降解,最佳初始pH值为8;原油浓度不高于10 g·L-1时降解效果较好;添加表面活性剂(十二烷基苯磺酸钠)能够提高混合菌群的降油效果,最佳添加浓度为50mg·L-1.气相色谱—模拟蒸馏分析结果表明,KLO-8对C11~C37的正构烷烃降解效果显著,随着碳原子数的增加,混合菌群对原油中正构烷烃的利用率逐渐降低.%For bioremediation of oil-contaminated soil under extreme conditions,a thermophilic oil-degrading bacterial group KLO-8 composed of four single strains was isolated from Karamay Oilfield oil-contaminated soil. Its optimal growth temperature was 45 - 55 °C ,and its highest resistant temperature was 75℃. Based on 16S rDNA sequence analysis, three single strains of KLO-8 was Bacillus sp. , one strain was Geobacillus sp.. The degrading performance of KLO-8 were discussed. The results showed that the optimal culture time was 7 d,the optimal nitrogen-phosphorus ratio was 3∶1,the initial pH value leaning alkalinity was more propitious to crude oil degradation and the optimal initial pH value was 8,the crude oil concentration below 10 g· L-1 was suitable,the addition of surfactant (sodium dodecyl benzene sulfonate) was able to improve the crude oil degradation rate and the optimal concentration was 50 mg ·L-1. Gas chromatogram-simulation distillation analysis result showed that KLO-8 was able to degrade the n-alkanes ranging from C11 to C37 and the degradation decreased with the long-chain alkanes

  9. Biodegradation of soil-applied pesticides by selected strains of plant growth-promoting rhizobacteria (PGPR) and their effects on bacterial growth.

    Science.gov (United States)

    Myresiotis, Charalampos K; Vryzas, Zisis; Papadopoulou-Mourkidou, Euphemia

    2012-04-01

    A laboratory study was conducted to investigate the influence of four PGPR strains on the degradation of five soil applied pesticides and their effects on bacterial growth. Interactions of Bacillus subtilis GB03, Bacillus subtilis FZB24, Bacillus amyloliquefaciens IN937a and Bacillus pumilus SE34 with two concentrations of acibenzolar-S-methyl, metribuzin, napropamide, propamocarb hydrochloride and thiamethoxam in liquid culture and soil microcosm were studied. The degradation of acibenzolar-S-methyl by all PGPR tested in low and high concentration, was 5.4 and 5.7 times, respectively, faster than that in non-inoculated liquid culture medium. At the end of the 72-h liquid cultured experiments, 8-18, 9-11, 15-36 and 11-22% of metribuzin, napropamide, propamocarb hydrochloride and thiamethoxam, respectively, had disappeared from PGPR inoculated medium. Under the soil microcosm experimental conditions, the half-lives of acibenzolar-S-methyl incubated in the presence of PGPR strains spiked at 1.0 and 10.0 mg kg(-1) were 10.3-16.4 and 9.2-15.9 days, respectively, markedly lower compared with >34.2 days in the control. From the rest pesticides studied degradation of propamocarb hydrochloride and thiamethoxam was enhanced in the presence of B. amyloliquefaciens IN937a and B. pumilus SE34. Acibenzolar-S-methyl, propamocarb hydrochloride and thiamethoxam significantly increased the PGPR growth. However, the stimulatory effect was related to the level of pesticide spiked.

  10. Characterization of a sodium dodecyl sulphate-