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Sample records for bacterium thiobacillus denitrificans

  1. Genetic manipulation of the obligate chemolithoautotrophic bacterium Thiobacillus denitrificans

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    Beller, H.R.; Legler, T.C.; Kane, S.R.

    2011-07-15

    Chemolithoautotrophic bacteria can be of industrial and environmental importance, but they present a challenge for systems biology studies, as their central metabolism deviates from that of model organisms and there is a much less extensive experimental basis for their gene annotation than for typical organoheterotrophs. For microbes with sequenced genomes but unconventional metabolism, the ability to create knockout mutations can be a powerful tool for functional genomics and thereby render an organism more amenable to systems biology approaches. In this chapter, we describe a genetic system for Thiobacillus denitrificans, with which insertion mutations can be introduced by homologous recombination and complemented in trans. Insertion mutations are generated by in vitro transposition, the mutated genes are amplified by the PCR, and the amplicons are introduced into T. denitrificans by electroporation. Use of a complementation vector, pTL2, based on the IncP plasmid pRR10 is also addressed.

  2. Anaerobic, Nitrate-Dependent Oxidation of U(IV) Oxide Minerals by the Chemolithoautotrophic Bacterium Thiobacillus denitrificans

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    Beller, H R

    2004-06-25

    Under anaerobic conditions and at circumneutral pH, cells of the widely-distributed, obligate chemolithoautotrophic bacterium Thiobacillus denitrificans oxidatively dissolved synthetic and biogenic U(IV) oxides (uraninite) in nitrate-dependent fashion: U(IV) oxidation required the presence of nitrate and was strongly correlated to nitrate consumption. This is the first report of anaerobic U(IV) oxidation by an autotrophic bacterium.

  3. Genome-enabled studies of anaerobic, nitrate-dependent iron oxidation in the chemolithoautotrophic bacterium Thiobacillus denitrificans

    Directory of Open Access Journals (Sweden)

    Harry R Beller

    2013-08-01

    Full Text Available Thiobacillus denitrificans is a chemolithoautotrophic bacterium capable of anaerobic, nitrate-dependent U(IV and Fe(II oxidation, both of which can strongly influence the long-term efficacy of in situ reductive immobilization of uranium in contaminated aquifers. We previously identified two c-type cytochromes involved in nitrate-dependent U(IV oxidation in T. denitrificans and hypothesized that c-type cytochromes would also catalyze Fe(II oxidation, as they have been found to play this role in anaerobic phototrophic Fe(II-oxidizing bacteria. Here we report on efforts to identify genes associated with nitrate-dependent Fe(II oxidation, namely (a whole-genome transcriptional studies [using FeCO3, Fe2+, and U(IV oxides as electron donors under denitrifying conditions], (b Fe(II oxidation assays performed with knockout mutants targeting primarily highly expressed or upregulated c-type cytochromes, and (c random transposon-mutagenesis studies with screening for Fe(II oxidation. Assays of mutants for 26 target genes, most of which were c-type cytochromes, indicated that none of the mutants tested were significantly defective in nitrate-dependent Fe(II oxidation. The non-defective mutants included the c1-cytochrome subunit of the cytochrome bc1 complex (complex III, which has relevance to a previously proposed role for this complex in nitrate-dependent Fe(II oxidation and to current concepts of reverse electron transfer. A transposon mutant with a disrupted gene associated with NADH:ubiquinone oxidoreductase (complex I was ~35% defective relative to the wild-type strain; this strain was similarly defective in nitrate reduction with thiosulfate as the electron donor. Overall, our results indicate that nitrate-dependent Fe(II oxidation in T. denitrificans is not catalyzed by the same c-type cytochromes involved in U(IV oxidation, nor have other c-type cytochromes yet been implicated in the process.

  4. Repair Effect of Thiobacillus Denitrificans and Denitrifying Bacterium on Pollution in Tianjin Waste Landfill Sites%脱氮硫杆菌和反硝化菌对天津市垃圾填埋场污染的修复研究

    Institute of Scientific and Technical Information of China (English)

    季彦; 郝金山; 薛祈

    2013-01-01

    Aiming at waste leachate samples from Tianjin waste landfill sites,the situation of waste with nitrifying bacteria and sulfate reducting bacteria in laboratory was discussed.The results showed that the metabolizable action of Thiobacillus denitrificans and denitrifying bacterium had strong function for nitrogen and organics removal.Under favorable conditions,it also could remove some metal pollutants.Through strengthening metabolizable action of some microorganism,the pollution system could be controlled and repaired.%针对天津市各大垃圾填埋场的渗沥液试样,论述试验室对垃圾掺入氮化物转化的硝化菌、硫化物转化的硫酸盐还原菌情况.结果表明:脱氮硫杆菌及反硝化菌的代谢作用具有较强的除氮及除去有机物的功能,有利条件下,还去除某些金属污染物质;通过强化某些微生物的代谢作用,可以对污染系统进行调控和修复.

  5. Structure of the two-domain hexameric APS kinase from Thiobacillus denitrificans: structural basis for the absence of ATP sulfurylase activity

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    Gay, Sean C. [Department of Chemistry, University of California, One Shields Avenue, Davis, CA 95616 (United States); Segel, Irwin H. [Section of Molecular and Cellular Biology, University of California, One Shields Avenue, Davis, CA 95616 (United States); Fisher, Andrew J., E-mail: fisher@chem.ucdavis.edu [Department of Chemistry, University of California, One Shields Avenue, Davis, CA 95616 (United States); Section of Molecular and Cellular Biology, University of California, One Shields Avenue, Davis, CA 95616 (United States)

    2009-10-01

    APS kinase from Thiobacillus denitrificans contains an inactive N-terminal ATP sulfurylase domain. The structure presented unveils the first hexameric assembly for an APS kinase, and reveals that structural changes in the N-terminal domain disrupt the ATP sulfurylase active site thus prohibiting activity. The Tbd-0210 gene of the chemolithotrophic bacterium Thiobacillus denitrificans is annotated to encode a 60.5 kDa bifunctional enzyme with ATP sulfurylase and APS kinase activity. This putative bifunctional enzyme was cloned, expressed and structurally characterized. The 2.95 Å resolution X-ray crystal structure reported here revealed a hexameric assembly with D{sub 3} symmetry. Each subunit contains a large N-terminal sulfurylase-like domain and a C-terminal APS kinase domain reminiscent of the two-domain fungal ATP sulfurylases of Penicillium chrysogenum and Saccharomyces cerevisiae, which also exhibit a hexameric assembly. However, the T. denitrificans enzyme exhibits numerous structural and sequence differences in the N-terminal domain that render it inactive with respect to ATP sulfurylase activity. Surprisingly, the C-terminal domain does indeed display APS kinase activity, indicating that this gene product is a true APS kinase. Therefore, these results provide the first structural insights into a unique hexameric APS kinase that contains a nonfunctional ATP sulfurylase-like domain of unknown function.

  6. Halobacterium denitrificans sp. nov., an extremely halophilic denitrifying bacterium

    Science.gov (United States)

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

    1986-01-01

    Halobacterium denitrificans was one of several carbohydrate-utilizing, denitrifying, extremely halophilic bacteria isolated by anaerobic enrichment in the presence of nitrate. Anaerobic growth took place only when nitrate (or nitrite) was present and was accompanied by the production of dinitrogen. In the presence of high concentrations of nitrate (i.e., 0.5 percent), nitrous oxide and nitrite were also detected. When grown aerobically in a mineral-salts medium containing 0.005 percent yeast extract, H. denitrificans utilized a variety of carbohydrates as sources of carbon and energy. In every case, carbohydrate utilization was accompanied by acid production.

  7. Halobacterium denitrificans sp. nov. - An extremely halophilic denitrifying bacterium

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

    1986-01-01

    Halobacterium denitrificans was one of several carbohydrate-utilizing, denitrifying, extremely halophilic bacteria isolated by anaerobic enrichment in the presence of nitrate. Anaerobic growth took place only when nitrate (or nitrite) was present and was accompanied by the production of dinitrogen. In the presence of high concentrations of nitrate (i.e., 0.5 percent), nitrous oxide and nitrite were also detected. When grown aerobically in a mineral-salts medium containing 0.005 percent yeast extract, H. denitrificans utilized a variety of carbohydrates as sources of carbon and energy. In every case, carbohydrate utilization was accompanied by acid production.

  8. 脱氮硫杆菌对废水中硫氮的脱除%Removal of Nitrate and Sulfide from Wastewater by Thiobacillus denitrificans

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    武鑫; 赵晋忠

    2013-01-01

    The growth curve of Thiobacillus denitrificans and pH of the culture media during the domestication process were determined to make sure the optimum condition for the removal of nitrate and sulfide in highly-concentrated wastewater. Then the ratio of sulfide to nitrate and the removing rate of NO3- were also examined in this paper. The results showed that when the S2- concentration in wastewater was 400 mg/L and the ratio of sulfide to nitrate was 5:3, the removing rate of NO3- could reach 63.19%, and S2- could simultaneously be converted into sulfate or elementary sulfur. These results indicated that Thiobacillus denitrificans had application potential in pollution control for nitrate and sulfide in wastewater. Fig 6, Tab 1, Ref 16%为脱除废水中高浓度的硫氮,首先对脱氮硫杆菌(Thiobacillus denitrificans)的生长曲线和驯化期间营养液pH 的变化进行了测定,确定了脱氮硫杆菌合适的使用条件.然后检测了接菌后废水中的S2-浓度控制在400 mg/L时合适的硫氮比以及脱氮硫杆菌对NO3的去除率.结果表明,处理富含硫氮的废水时,当硫氮比控制在5:3、S2-浓度控制在400mg/L时,脱氮硫杆菌对NO3的去除率可达63.19%,同时S2-转化成硫酸盐或可回收的单质硫,使废水的硫氮污染得到了有效的控制.

  9. Whole-Genome Transcriptional Analysis of Chemolithoautotrophic Thiosulfate Oxidation by Thiobacillus denitrificans Under Aerobic vs. Denitrifying Conditions

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    Beller, H R; Letain, T E; Chakicherla, A; Kane, S R; Legler, T C; Coleman, M A

    2006-04-22

    Thiobacillus denitrificans is one of the few known obligate chemolithoautotrophic bacteria capable of energetically coupling thiosulfate oxidation to denitrification as well as aerobic respiration. As very little is known about the differential expression of genes associated with ke chemolithoautotrophic functions (such as sulfur-compound oxidation and CO2 fixation) under aerobic versus denitrifying conditions, we conducted whole-genome, cDNA microarray studies to explore this topic systematically. The microarrays identified 277 genes (approximately ten percent of the genome) as differentially expressed using Robust Multi-array Average statistical analysis and a 2-fold cutoff. Genes upregulated (ca. 6- to 150-fold) under aerobic conditions included a cluster of genes associated with iron acquisition (e.g., siderophore-related genes), a cluster of cytochrome cbb3 oxidase genes, cbbL and cbbS (encoding the large and small subunits of form I ribulose 1,5-bisphosphate carboxylase/oxygenase, or RubisCO), and multiple molecular chaperone genes. Genes upregulated (ca. 4- to 95-fold) under denitrifying conditions included nar, nir, and nor genes (associated respectively with nitrate reductase, nitrite reductase, and nitric oxide reductase, which catalyze successive steps of denitrification), cbbM (encoding form II RubisCO), and genes involved with sulfur-compound oxidation (including two physically separated but highly similar copies of sulfide:quinone oxidoreductase and of dsrC, associated with dissimilatory sulfite reductase). Among genes associated with denitrification, relative expression levels (i.e., degree of upregulation with nitrate) tended to decrease in the order nar > nir > nor > nos. Reverse transcription, quantitative PCR analysis was used to validate these trends.

  10. 养殖池塘系统脱氮硫杆菌(Thiobacillus denitrificans)的分离、生长特性及脱氮特征研究%Isolation and Culture of Thiobacillus denitrificans from Different Area of the Intensive Pond System and Their Capacities of Removing Nitrate

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    范立民; 裘丽萍; 陈家长; 宋超; 胡庚东; 瞿建宏; 孟顺龙; 吴伟

    2013-01-01

    分别采集集约化养殖吉富罗非鱼(Oreochromis niloticus)的池塘底泥、表层水、塘边裸露土壤样品,采用脱氮硫杆菌选择培养基富集培养、分离得到3株细菌,通过菌落特征、形态学特征、生理生化检验和16S rDNA序列分析等手段,鉴定为脱氮硫杆菌(Thiobacillus denitrificans),命名为TD1、TD2和TD3.在30℃下,采用静置、厌氧培养实验研究这3株脱氮硫杆菌的生长繁殖特征、对硝酸盐氮的去除速率特征、硫酸根产生状况、亚硝酸盐产生情况、培养液pH值和氧化还原电位变化特征等方面的差异进行研究,探索养殖环境修复中应用的可能性.结果表明:在一定的时间内菌株生长速率、介质pH降低速率和氧化还原电位上升幅度均表现为TD1>TD2>TD3;菌株硝态氮脱除效率和硫酸根浓度升高速率均表现为TD1>TD2>TD3,亚硝酸盐产生情况则表现为TD1<TD2<TD3;TD1更适合异位修复,TD2更适合原位修复.%In this study, an intensive pond in which GIFT tilapia( Oreochromis niloticus ) were cultured was used. And sampling were done in different areas of the pond system, including sediments of the pond, the waters 50 centimeters below the surface and the bare soil at the edge of the pond. After that, enrichment and elective cultures were prepared anaerobically on these samples in 30 centigrade by incubating glass-stoppered bottles with the medium for Thiobacillus denitrificans full filled. After the culture, by using the spread-plate method, three strains were got. Through the appearance of the colonies, the shape of the strains, the detection of physiological and biochemical indicators, and the analysis of the sequences of 16S rDNA, the strains was identified as Thiobacillus denitrificans, and they were named as TD1, TD2 and TD3. Through the studies on the characteristics of growth and reproduction, of the removing rates of the nitrate, of the production of the sulfate and nitrite, and of

  11. 脱氮硫杆菌生长特性及其对SRB生长的影响%CHARACTERISTICS OF THIOBACILLUS DENITRIFICANS AND THE EFFECT ON THE GROWTH OF SRB

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    刘宏芳; 汪梅芳; 许立铭

    2003-01-01

    由土壤中分离得到一株自养型的脱氮硫杆菌(Thiobacillus denitrificans,硫杆菌属,硫杆菌科,革兰氏阴性化能自养细菌),该菌株的最佳生长pH为7.0.将此菌株与硫酸盐还原菌(Sulfate Reducing Bacteria, SRB,脱硫弧菌属,革兰氏阴性厌氧细菌)混合培养,测定SRB的菌量变化,结果表明,脱氮硫杆菌的生长抑制了硫酸盐还原菌的生长,降低了SRB的腐蚀性的代谢产物硫化物的浓度,腐蚀速率降低,有利于防治SRB引起的微生物腐蚀.

  12. 脱氮硫杆菌利用不同硫源去除地下水硝酸盐的实验研究%The Thiobacillus Denitrificans Use of Different Sulfur Source to Remove the Nitrate of Groundwater

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    孙莹

    2012-01-01

    从斛兵塘底土壤中分离得到一株自养反硝化菌。该菌株经过生理生化实验,初步判定为脱氮硫杆菌。该菌株可以分别利用黄铁矿、硫代硫酸钠、硫单质作电子供体,进行反硝化代谢。实验表明,在黄铁矿存在下该菌种对硝酸盐氮去除率最高,同时也有较商的硫酸根生成率。为了去除硫酸根新污染,尝试在培养基中加入石灰石。经实验证明.在培养基中加入石灰石几乎不影响反硝化代谢,并且有效的去除硫酸根离子,达到去除硝酸盐的目的。%A strain of Thiobacillus was isolated from the soil of the bottom of the Hubing Pool. Based on the analysis of physiological and biochemical measurements, this stain was identified with Thiobacillus denitrificans. The stain was employed to reduce Nitrate nitrogen by using of pyrite, thiosulfate and brimstone as electron donor. Experiments show that, the T.D get the highest nitrate nitrogen removal rate by using of pyrite, and also higher sulfate formation rate. In order to remove the sulfate pollution, try to add limestone in the pyrite medium, The pyrite medium by adding limestone make the nitrate nitrogen removal rate Almost no decreased, and effective removal of sulfate produced from denitrification, and ultimately achieve the purpose of remove the nitrate.

  13. Effects of ionic strength on the coordination of Eu(III) and Cm(III) to a Gram-negative bacterium, Paracoccus denitrificans

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    Ozaki, T.; Ohnuki, T. [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki (Japan); Kimura, T. [Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency, Tokai, Ibaraki (Japan); Francis, A.J. [Environmental Sciences Dept., Brookhaven National Lab., Upton, NY (United States)

    2006-07-01

    We studied the effect of ionic strength on the interactions of Europium(III) and Curium(III) with a Gram-negative bacterium Paracoccus denitrificans. Bacterial cells grown in 0.5-, 3.5-, and 5.0% NaCl were used in adsorption experiments and laser experiments that were performed at the same ionic strengths as those in the original growth media. The distribution ratio (log K{sub d}) for Eu(III) and Cm(III) was determined at pHs 3-5. To elucidate the coordination environment of Eu(III) adsorbed on P. denitrificans, we estimated the number of water molecules in the inner sphere and strength of the ligand field by time-resolved laser-induced fluorescence spectroscopy (TRLFS) at pHs 4-6. The log K{sub d} of Eu(III) and Cm(III) increased with an increase of pH at all ionic strengths because there was less competition for ligands in cells with H{sup +} at higher pHs, wherein less H{sup +} was present in solution: cation adsorption generally occurs through an exchange with H{sup +} on the functional groups of coordination sites. No significant differences were observed in the log K{sub d} of Eu(III) and Cm(III) at each pH in 0.5-, 3.5-, and 5.0% NaCl solutions, though competition for ligands with Na{sup +} would be expected to increase at higher NaCl concentrations. The log K{sub d} of Eu(III) was almost equivalent to that of Cm(III) under all the experimental conditions. TRLFS showed that the coordination environments of Eu(III) did not differ from each other at 0.5-, 3.5-, and 5.0% NaCl at pHs 4-6. TRLFS also showed that the characteristic of the coordination environment of Eu(III) on P. denitrificans was similar to that on a halophile, Nesterenkonia halobia, while it significantly differed from that on a non-halophile, Pseudomonas putida. These findings indicate that the number of coordination sites for Eu(III) on P. denitrificans, whose cell surface may have similar structures to that of halophiles, increased with increasing ionic strength, though their structure

  14. Identify biosorption effects of Thiobacillus towards perfluorooctanoic acid (PFOA): Pilot study from field to laboratory.

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    Li, Lei; Wang, Tieyu; Sun, Yajun; Wang, Pei; Yvette, Baninla; Meng, Jing; Li, Qifeng; Zhou, Yunqiao

    2017-03-01

    The concentration of Perfluoroalkyl acids (PFAAs) and the bacterial community composition along the Xiaoqing River were explored with HPLC-MS/MS and Illumina high-throughput sequencing in present study. The results showed that perfluorooctanoic acid (PFOA) was the predominant PFAAs in all sediment samples, and high level of PFOA could lead to an evident increase in the abundance of Thiobacillus. Thiobacillus was identified with the survival ability in high concentrations of PFOA accordingly. Therefore, Thiobacillus thioparus and Thiobacillus denitrificans were selected as receptors to design indoor biosorption experiment. The growth curves under different PFOA concentrations and residual rates of PFOA in the processes of cultivation were analyzed. The results showed that upwards concentrations of PFOA below 5000 ng/L led to an obvious increase in the growth rate of T. thioparus. Whereas PFOA promoted the growth of T. denitrificans in a relatively limited range of concentration, and the effect was not obvious. The addition of different concentrations of PFOA had no apparent effects on pH values in the media of both T. thioparus and T. denitrificans. The concentrations of PFOA in liquid media reduced after the process of bacteria culturing. The removal rates of T. thioparus and T. denitrificans to PFOA were 21.1-26.8% and 13.5-18.4%, respectively. The current findings indicated that T. thioparus could play a significant role as potential biosorbent with the ability to eliminate PFOA effectively in aquatic environment, which would provide novel information for PFOA ecological decontamination and remediation.

  15. Acidostability of speroplasts prepared from Thiobacillus thiooxidans.

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    Noguchi, A; Takama, M; Sekiguchi, T; Koyama, N; Nosoh, Y

    1977-03-01

    Thiobacillus thiooxidans was acidostable even in the absence of its respiratory substrate, elementary sulfur. This suggests that the acidostability of the bacterium was enery-independent. The organism was subjected to osmotic shock with 0.75 M sucrose at 0 degrees C and then treated with snail intestinal juice in the presence of 0.3 M sucrose. The decrease in the optical density of the sample thus prepared on dilution with deionized water and electron microscopic observation of the sample showed that spheroplasts were formed from the bacterium by this procedure. Spheroplasts were able to respire sulfur and their respiratory activity was acidostable. Spheroplasts, when treated with Nagase, proteolytic enzyme, lost their acidostability, and some protein components disappeared from the membrane fraction. This suggests that the acidostability of the bacterium may be related to protein conponents of the membrane.

  16. Carbohydrate metabolism and carbon fixation in Roseobacter denitrificans OCh114.

    Directory of Open Access Journals (Sweden)

    Kuo-Hsiang Tang

    Full Text Available The Roseobacter clade of aerobic marine proteobacteria, which compose 10-25% of the total marine bacterial community, has been reported to fix CO(2, although it has not been determined what pathway is involved. In this study, we report the first metabolic studies on carbohydrate utilization, CO(2 assimilation, and amino acid biosynthesis in the phototrophic Roseobacter clade bacterium Roseobacter denitrificans OCh114. We develop a new minimal medium containing defined carbon source(s, in which the requirements of yeast extract reported previously for the growth of R. denitrificans can be replaced by vitamin B(12 (cyanocobalamin. Tracer experiments were carried out in R. denitrificans grown in a newly developed minimal medium containing isotopically labeled pyruvate, glucose or bicarbonate as a single carbon source or in combination. Through measurements of (13C-isotopomer labeling patterns in protein-derived amino acids, gene expression profiles, and enzymatic activity assays, we report that: (1 R. denitrificans uses the anaplerotic pathways mainly via the malic enzyme to fix 10-15% of protein carbon from CO(2; (2 R. denitrificans employs the Entner-Doudoroff (ED pathway for carbohydrate metabolism and the non-oxidative pentose phosphate pathway for the biosynthesis of histidine, ATP, and coenzymes; (3 the Embden-Meyerhof-Parnas (EMP, glycolysis pathway is not active and the enzymatic activity of 6-phosphofructokinase (PFK cannot be detected in R. denitrificans; and (4 isoleucine can be synthesized from both threonine-dependent (20% total flux and citramalate-dependent (80% total flux pathways using pyruvate as the sole carbon source.

  17. Novel cyanide-hydrolyzing enzyme from Alcaligenes xylosoxidans subsp. denitrificans

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    Ingvorsen, K.; Hojer-Pederson, B.; Godtfredsen, S.E. (Novo Nordisk A/S, Bagsvaerd (Denmark))

    1991-06-01

    A cyanide-metabolizing bacterium, strain DF3, isolated from soil was identified as Alcaligenes xylosoxidans subsp. denitrificans. Whole cells and cell extracts of strain DF3 catalyzed hydrolysis of cyanide to formate and ammonia (HCN + 2H{sub 2}O {r arrow} HCOOH + NH{sub 3}) without forming formamide as a free intermediate. The cyanide-hydrolyzing activity was inducibly produced in cells during growth in cyanide-containing media. Cyanate (OCN{sup {minus}}) and a wide range of aliphatic and aromatic nitriles were not hydrolyzed by intact cells of A. xylosoxidans subsp. denitrificans DF3. Strain DF3 hydrolyzed cyanide with great efficacy. Thus, by using resting induced cells at a concentration of 11.3 mg (dry weight) per ml, the cyanide concentration could be reduced from 0.97 M (approximately 25,220 ppm) to less than 77 nM (approximately 0.002 ppm) in 55 h. Enzyme purification established that cyanide hydrolysis by A. xylosoxidans subsp. denitrificans DF3 was due to a single intracellular enzyme. The molecular mass of the active enzyme (purity, {gt}97% as determined by amino acid sequencing) was estimated to be {gt}300,000 Da. The cyanide-hydrolyzing enzyme of A. xylosoxidans subsp. denitrificans DF3 was tentatively named cyanidase to distinguish it from known nitrilases (EC 3.5.5.1) which act on organic nitriles.

  18. Microbial desulfurization of coal by Thiobacillus ferrooxidans and thermophilic archaea

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    Olsson, G.; Pott, B.-M.; Larsson, L.; Holst, O.; Karlsson, H.T. (Univ. of Lund, Lund (Sweden). Dept. of Chemical Engineering II, Chemical Center)

    1994-11-01

    Several different microorganisms have been suggested for desulfurization. In the present investigation, the thermophilic archaea [ital Acidianus brierleyi] (DSM 1651), [ital Sulfolobus acidocaldarius] (DSM 639) and [ital Sulfolobus solfataricus] (DSM 1616) were compared with the mesophyilic bacterium [ital Thiobacillus ferrooxidans] (DSM 583) concerning their capability of removing sulfur from coal. The desulfurization rate as well as the amount of sulfur removed by the microorganisms was studied. Two of the investigated microorganisms [ital Thiobacillus ferrooxidans] and [ital Acidianus brierleyi], were capable of oxidizing pure pyrite as well as oxidizing sulfur in coal. A kinetic analysis was performed assuming first order reactions. The rate constant for oxidation of pure pyrite by [ital A. brierleyi] was observed to be higher than for [ital T. ferrooxidans]. The values of the rate constants for sulfur removal from coal were comparable for the two microorganisms, but were higher than for oxidation of pure pyrite. 18 refs., 2 figs., 1 tab.

  19. SULFIDE OXIDATION UNDER OXYGEN LIMITATION BY A THIOBACILLUS-THIOPARUS ISOLATED FROM A MARINE MICROBIAL MAT

    NARCIS (Netherlands)

    VANDENENDE, FP; VANGEMERDEN, H

    1993-01-01

    The colorless sulfur bacterium Thiobacillus thioparus T5, isolated from a marine microbial mat, was grown in continuous culture under conditions ranging from sulfide limitation to oxygen limitation. Under sulfide-limiting conditions, sulfide was virtually completely oxidized to sulfate. Under oxygen

  20. Thiobacillus ferrooxidans detection using immunoelectron microscopy.

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    Coto, O; Fernández, A I; León, T; Rodríguez, D

    1992-11-01

    A specific, fast and very sensitive immunoelectron microscopy method was developed to morphologically and serologically distinguish different cultures of iron oxidizers. Bacteria isolated from the acidic waters of "Matahambre" and "Mina Delita" mines (Cuba) were characterized. An antiserum specific to Thiobacillus ferrooxidans did not react with other bacteria also present in the acidic waters of mine drainage. Our results suggest the occurrence of some strains of Thiobacillus ferrooxidans, Thiobacillus thiooxidans and Leptospirillum ferrooxidans in these waters.

  1. Fatty acids of Thiobacillus thiooxidans.

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    Levin, R A

    1971-12-01

    Fatty acid spectra were made on Thiobacillus thiooxidans cultures both in the presence and absence of organic compounds. Small additions of glucose or acetate had no significant effect either on growth or fatty acid content. The addition of biotin had no stimulatory effect but did result in slight quantitative changes in the fatty acid spectrum. The predominant fatty acid was a C(19) cyclopropane acid.

  2. The metabolic impact of extracellular nitrite on aerobic metabolism of Paracoccus denitrificans.

    Science.gov (United States)

    Hartop, K R; Sullivan, M J; Giannopoulos, G; Gates, A J; Bond, P L; Yuan, Z; Clarke, T A; Rowley, G; Richardson, D J

    2017-02-07

    Nitrite, in equilibrium with free nitrous acid (FNA), can inhibit both aerobic and anaerobic growth of microbial communities through bactericidal activities that have considerable potential for control of microbial growth in a range of water systems. There has been much focus on the effect of nitrite/FNA on anaerobic metabolism and so, to enhance understanding of the metabolic impact of nitrite/FNA on aerobic metabolism, a study was undertaken with a model denitrifying bacterium Paracoccus denitrificans PD1222. Extracellular nitrite inhibits aerobic growth of P. denitrificans in a pH-dependent manner that is likely to be a result of both nitrite and free nitrous acid (pKa = 3.25) and subsequent reactive nitrogen oxides generated from the intracellular passage of FNA into P. denitrificans. Increased expression of a gene encoding a flavohemoglobin protein (Fhp) (Pden_1689) was observed in response to extracellular nitrite. Construction and analysis of a deletion mutant established Fhp to be involved in endowing nitrite/FNA resistance at high extracellular nitrite concentrations. Global transcriptional analysis confirmed nitrite-dependent expression of fhp and indicated that P. denitrificans expressed a number of stress response systems associated with protein, DNA and lipid repair. It is therefore suggested that nitrite causes a pH-dependent stress response that is due to the production of associated reactive nitrogen species, such as nitric oxide from the internalisation of FNA.

  3. Preservation of Thiobacillus ferrooxidans and Thiobacillus thiooxidans with activity check.

    Science.gov (United States)

    Gupta, S G; Agate, A D

    1986-01-01

    Cultures of Thiobacillus ferrooxidans and Thiobacillus thiooxidans, used in biohydrometallurgical processes of economic importance, are very difficult to preserve by conventional methods. Hence, to preserve the cultures with their activity intact, various techniques were tried, after determining their respective activity in terms of Iron Oxidation Rate (IOR) and Sulfur Oxidation Rate (SOR). Among the methods tested, along with the recommended method of serial transfer in a liquid medium, were methods such as lyophilization, storage in a liquid nitrogen and mixing with sterile, inert carriers like lignite or chalcopyrite ores. After a period check-up at 4 months and 8 months storage, it was found that out of these methods, mixing with sterile ore followed by storage at 8 degrees C, kept both types of activities intact. The temperature of storage was observed to have a definite effect on activity, in that when the preserved cultures were stored at 8 degrees C, the activity was retained, whereas at 28-30 degrees C (RT) storage, the activity of all the cultures preserved by various techniques, dropped significantly.

  4. Absorption and utilization of organic matter by the strict autotroph, Thiobacillus thiooxidans, with special reference to aspartic acid.

    Science.gov (United States)

    Butler, R G; Umbreit, W W

    1966-02-01

    Butler, Richard G. (Rutgers, The State University, New Brunswick, N.J.), and Wayne W. Umbreit. Absorption and utilization of organic matter by the strict autotroph, Thiobacillus thiooxidans, with special reference to aspartic acid. J. Bacteriol. 91:661-666. 1966.-The strictly autotrophic bacterium, Thiobacillus thiooxidans, can be shown to assimilate a variety of organic materials. Aspartic acid can be assimilated into protein and can be converted into CO(2), but even in the presence of sulfur it cannot serve as the sole source of carbon for growth. The reason appears to be that aspartic acid is converted into inhibitory materials.

  5. Attachment of Thiobacillus thiooxidans to sulfur crystals.

    Science.gov (United States)

    SCHAEFFER, W I; HOLBERT, P E; UMBREIT, W W

    1963-01-01

    Schaeffer, W. I. (Rutgers, The State University, New Brunswick, N.J.), P. E. Holbert, and W. W. Umbreit. Attachment of Thiobacillus thiooxidans to sulfur crystals. J. Bacteriol. 85:137-140. 1963.-Electron micrographs of replicas of sulfur crystals before and after attack by Thiobacillus thiooxidans show that the microorganisms erode the crystal in the area immediately adjacent to the cell. When there are many cells, the entire crystal surface appears eroded.

  6. THE DEPRESSION OF PYRITE FLOTATION BY THIOBACILLUS FERROOXIDANS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The experimental studies on the microbial flotation of a pure pyrite sample using Thiobacillus ferrooxidans was conducted in the laboratory. The results indicate that Thiobacillus ferrooaidans has strong depression effect on the flotation of pyrite. Thiobacillus f errooxidans can adsorb on the surface of pyrite in a very short time (a few min. ), changing the surface from hydrophobic into hydrophilic and making the pyrite particles to lose their floatability. Therefore, Thiobacillus ferrooxidans is an effective microbial depressant of pyrite. It has also been pointed out that the depression of pyrite by Thiobacillus ferrooxidans is caused by the adsorption of the microbial colloids, but not by the oxidation effect.

  7. Bioflotation of pyrite with Thiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    Shaoxian Song; Yimin Zhang; Shouci Lu

    2004-01-01

    Bioflotation of pyrite with bacteria Thiobacillus ferrooxidans in the presence or absence of potassium ethyl xanthate was studied on a pure pyrite through microflotation and electrophoretic light scattering measurements. The experimental results showed that in the absence of xanthate, pyrite flotation is slightly enhanced by Thiobacillus ferrooxidans. However, with xanthate as a collector, pyrite flotation is strongly depressed after being exposed to the bacteria. The longer is the time when the pyrite is exposed to the bacteria, the stronger the depression is. The mechanism of the depression might be due to the formation of the biofilms of Thiobacillus ferrooxidans on pyrite surfaces, preventing the adsorption of xanthate on pyrite surfaces in the form of dixanthogen or xanthate ions.

  8. GROWTH OF THIOBACILLUS THIOOXIDANS IN SHAKEN CULTURE.

    Science.gov (United States)

    COOK, T M

    1964-09-01

    Cook, Thomas M. (Rutgers, The State University, New Brunswick, N.J.). Growth of Thiobacillus thiooxidans in shaken culture. J. Bacteriol. 88:620-623. 1964.-When flasks of sulfur-containing medium were inoculated with Thiobacillus thiooxidans and placed on a shaking machine immediately after inoculation, growth was markedly inhibited. If various wetting agents were provided, or if the ratio of inoculum to sulfur was increased, growth under shaking conditions was possible. Evidence cited shows that the natural wetting agent (or other externally supplied surfactants) is necessary to effect a bacteria-sulfur contact which is stable to shaking conditions.

  9. Effect of various ions, pH, and osmotic pressure on oxidation of elemental sulfur by Thiobacillus thiooxidans

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, I.; Lee, D.; Mackay, B.; Harahuc, L.; Oh, J.K.

    1999-11-01

    The oxidation of elemental sulfur by Thiobacillus thiooxidans was studied at pH 2.3, 4.5, and 7.0 in the presence of different concentrations of various anions (sulfate, phosphate, chloride, nitrate, and fluoride) and cations (potassium, sodium, lithium, rubidium, and cesium). The results agree with the expected response of this acidophilic bacterium to charge neutralization of colloids by ions, pH-dependent membrane permeability of ions, and osmotic pressure.

  10. Effect of various ions, pH, and osmotic pressure on oxidation of elemental sulfur by Thiobacillus thiooxidans.

    Science.gov (United States)

    Suzuki, I; Lee, D; Mackay, B; Harahuc, L; Oh, J K

    1999-11-01

    The oxidation of elemental sulfur by Thiobacillus thiooxidans was studied at pH 2.3, 4.5, and 7.0 in the presence of different concentrations of various anions (sulfate, phosphate, chloride, nitrate, and fluoride) and cations (potassium, sodium, lithium, rubidium, and cesium). The results agree with the expected response of this acidophilic bacterium to charge neutralization of colloids by ions, pH-dependent membrane permeability of ions, and osmotic pressure.

  11. The terminal oxidases of Paracoccus denitrificans

    OpenAIRE

    de Gier, Jan-Willem L.; Lübben, Mathias; Reijnders, Willem N.M.; Tipker, Corinne A.; Slotboom, Dirk-Jan; Van Spanning, Rob J. M.; Stouthamer, Adriaan H.; van der Oost, John

    1994-01-01

    Three distinct types of terminal oxidases participate in the aerobic respiratory pathways of Paracoccus denitrificans. Two alternative genes encoding subunit I of the aa3-type cytochrome c oxidase have been isolated before, namely ctaDI and ctaDII. Each of these genes can be expressed separately to complement a double mutant (ΔctaDI, ΔctaDII), indicating that they are isoforms of subunit I of the aa3-type oxidase. The genomic locus of a quinol oxidase has been isolated: cyoABC. This protohaem...

  12. PROGRESS OF THE STUDIES ON GENE TRANSFER SYSTEM OF THIOBACILLUS FERROOXIDANS%氧化亚铁硫杆菌基因转移系统研究进展

    Institute of Scientific and Technical Information of China (English)

    林建群; 彭基斌; 颜望明

    2001-01-01

    Thiobacillus ferrooxidans is a extremely acidophilic and obligately chemlithotrophic bacterium. It is the most important work for gene engineering of T.ferrooxidans to develop an efficient gene transfer systems. This paper summarized the genetics background of T.ferrooxidans, the process of establishing such a kind of gene transfer system, and its application in constructing arsenic resistance genetically engineered bacteria. Ref 22

  13. [Comparative susceptibility of Ochrobactrum anthropi, Agrobacterium tumefaciens, Alcaligenes faecalis, Alcaligenes denitrificans subsp. denitrificans, Alcaligenes denitrificans subsp. xylosidans and Bordetella bronchiseptica against 35 antibiotics including 17 beta-lactams].

    Science.gov (United States)

    Bizet, C; Bizet, J

    1995-04-01

    Ochrobactrum anthropi, formerly known as "Achromobacter sp." or CDC group Vd has been isolated from water, hospital environment (antiseptic solutions, dialysis fluids ... ). O. anthropi is a Gram negative, motile, strictly aerobic, oxydase positive and non-fermentative bacteria with a strong urease activity. The susceptibility of 13 strains of O. anthropi was determined by agar diffusion method and compared to those of type strains of Agrobacterium tumefaciens, Alcaligenes faecalis, Alcaligenes denitrificans subsp. denitrificans, Alcaligenes denitrificans subsp. xylosoxydans and Bordetella bronchiseptica. The MICs of 20 antimicrobial agents confirmed the distinct phenotype susceptibility of O. anthropi. All the strains of O. anthropi are sensitive to imipenem, amikacin, gentamicin, netilmicin, nalidixic acid, pefloxacin, ciprofloxacin, tetracyclin, colistin, sulphonamides and rifampicin and resistant to ampicillin, amoxycillin + clavulanic acid, ticarcillin, mezlocillin, cefuroxime, cefamandol, cefoxitin, cefotaxime, cefoperazon, ceftazidime, cefsulodin, aztreonam, streptomycin, kanamycin, pipemidic acid, chloramphenicol, erythromicin, pristinamycin, trimethoprim and fosfomycin. O. anthropi is implicated in nosocomial infections. O. anthropi was the species with the greatest resistance to beta-lactamins.

  14. Basis of pyruvate inhibition in Thiobacillus thiooxidans.

    Science.gov (United States)

    Rao, G S; Berger, L R

    1970-05-01

    Addition of 10(-3)m pyruvic acid to cultures of Thiobacillus thiooxidans, at pH 2.3, results in its rapid intracellular accumulation and in the cessation of sulfur oxidation, CO(2) fixation, and oxygen consumption; at pH 7.0, pyruvate neither inhibits oxygen uptake nor accumulates appreciably intracellularly. Pyruvate does not affect CO(2) fixation in cell-free extracts. The data suggest that the cells of T. thiooxidans are passively permeable to pyruvic acid at low pH. Thus entry of pyruvic acid causes accumulation of pyruvate with a concomitant decrease in intracellular pH.

  15. Biocorrosion produced by Thiobacillus-like microorganisms.

    Science.gov (United States)

    López, A I; Marín, I; Amils, R

    1994-01-01

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

  16. Oxidation of Elemental Sulfur to Sulfite by Thiobacillus thiooxidans Cells

    OpenAIRE

    Suzuki, Isamu; Chan, C. W.; Takeuchi, T. L.

    1992-01-01

    Thiobacillus thiooxidans cells oxidized elemental sulfur to sulfite, with 1 mol of O2 consumption per mol of sulfur oxidized to sulfite, when the oxidation of sulfite was inhibited with 2-n-heptyl-4-hydroxyquinoline N-oxide.

  17. Permanent draft genome of Thiobacillus thioparus DSM 505(T), an obligately chemolithoautotrophic member of the Betaproteobacteria.

    Science.gov (United States)

    Hutt, Lee P; Huntemann, Marcel; Clum, Alicia; Pillay, Manoj; Palaniappan, Krishnaveni; Varghese, Neha; Mikhailova, Natalia; Stamatis, Dimitrios; Reddy, Tatiparthi; Daum, Chris; Shapiro, Nicole; Ivanova, Natalia; Kyrpides, Nikos; Woyke, Tanja; Boden, Rich

    2017-01-01

    Thiobacillus thioparus DSM 505(T) is one of first two isolated strains of inorganic sulfur-oxidising Bacteria. The original strain of T. thioparus was lost almost 100 years ago and the working type strain is Culture C(T) (=DSM 505(T) = ATCC 8158(T)) isolated by Starkey in 1934 from agricultural soil at Rutgers University, New Jersey, USA. It is an obligate chemolithoautotroph that conserves energy from the oxidation of reduced inorganic sulfur compounds using the Kelly-Trudinger pathway and uses it to fix carbon dioxide It is not capable of heterotrophic or mixotrophic growth. The strain has a genome size of 3,201,518 bp. Here we report the genome sequence, annotation and characteristics. The genome contains 3,135 protein coding and 62 RNA coding genes. Genes encoding the transaldolase variant of the Calvin-Benson-Bassham cycle were also identified and an operon encoding carboxysomes, along with Smith's biosynthetic horseshoe in lieu of Krebs' cycle sensu stricto. Terminal oxidases were identified, viz. cytochrome c oxidase (cbb3, EC 1.9.3.1) and ubiquinol oxidase (bd, EC 1.10.3.10). There is a partial sox operon of the Kelly-Friedrich pathway of inorganic sulfur-oxidation that contains soxXYZAB genes but lacking soxCDEF, there is also a lack of the DUF302 gene previously noted in the sox operon of other members of the 'Proteobacteria' that can use trithionate as an energy source. In spite of apparently not growing anaerobically with denitrification, the nar, nir, nor and nos operons encoding enzymes of denitrification are found in the T. thioparus genome, in the same arrangements as in the true denitrifier T. denitrificans.

  18. Growth kinetics of Thiobacillus ferrooxidans in bioelectrochemical cell

    Institute of Scientific and Technical Information of China (English)

    李宏煦; 王淀佐; 邱冠周; 胡岳华

    2004-01-01

    Thiobacillus ferrooxidans might be the most important bacteria used in biometallurgy. The foundation way of its growth process is oxidizing ferrous in order to obtain energy needed for metabolism, but the variation of ferrous concentration and mixed potential of the culture media would have crucial effect on the bacteria growth.Based on the characteristics of Thiobacillus ferrooxidans growth and redox potential of ferric and ferrous, an electrochemical cell was designed conventionally to study growth rule and the relationship between redox potential and bacteria growth was built up, and some growth kinetics of Thiobacillus ferrooxidans were elucidated. It demonstrates that the variation of open potential of electrochemical cell △E shows the growth tendency of Thiobacillus ferrooxidans, at the initial growth stage, the value of △E increases slowly, when at logistic growth stage, it increases drastically, and the growth rate of bacteria is linear with the oxidation rate of ferrous. The bacteria growth kinetics model is proposed using Monod and Michealis-Menten equation, and the kinetics parameters are got. The consistence of the measured and the calculated results proves that it is proper to use the proposed kinetics model and the electrochemical cell method to describe the growth rule of Thiobacillus ferrooxidans.

  19. Respiratory Complex I in Bos taurus and Paracoccus denitrificans Pumps Four Protons across the Membrane for Every NADH Oxidized.

    Science.gov (United States)

    Jones, Andrew J Y; Blaza, James N; Varghese, Febin; Hirst, Judy

    2017-03-24

    Respiratory complex I couples electron transfer between NADH and ubiquinone to proton translocation across an energy-transducing membrane to support the proton-motive force that drives ATP synthesis. The proton-pumping stoichiometry of complex I (i.e. the number of protons pumped for each two electrons transferred) underpins all mechanistic proposals. However, it remains controversial and has not been determined for any of the bacterial enzymes that are exploited as model systems for the mammalian enzyme. Here, we describe a simple method for determining the proton-pumping stoichiometry of complex I in inverted membrane vesicles under steady-state ADP-phosphorylating conditions. Our method exploits the rate of ATP synthesis, driven by oxidation of NADH or succinate with different sections of the respiratory chain engaged in catalysis as a proxy for the rate of proton translocation and determines the stoichiometry of complex I by reference to the known stoichiometries of complexes III and IV. Using vesicles prepared from mammalian mitochondria (from Bos taurus) and from the bacterium Paracoccus denitrificans, we show that four protons are pumped for every two electrons transferred in both cases. By confirming the four-proton stoichiometry for mammalian complex I and, for the first time, demonstrating the same value for a bacterial complex, we establish the utility of P. denitrificans complex I as a model system for the mammalian enzyme. P. denitrificans is the first system described in which mutagenesis in any complex I core subunit may be combined with quantitative proton-pumping measurements for mechanistic studies.

  20. Bacterial leaching of a sulfide ore by Thiobacillus ferrooxidans and Thiobacillus thiooxidans: I. Shake flask studies.

    Science.gov (United States)

    Lizama, H M; Suzuki, I

    1988-06-20

    Bacterial leaching of a sulfide ore containing pyrite, chalcopyrite, and sphalerite was studied in shake flask experiments using Thiobacillus ferrooxidans and Thiobacillus thiooxidans strains isolated from mine sites. The Fe(2+)grown T. ferrooxidans isolates solubilized sphalerite preferentially over chalcopyrite leaching 7-10% Cu, 68-76% Zn, and 10-22% Fe from the ore in 18 days. The sulfur grown T. thiooxidans isolates leached Zn much more slowly and very little Fe, with a Cu-Zn extraction ratio twice the value obtained with T. ferrooxidans. The ore adapted T. ferrooxidans started solubilizing Cu and Zn without a lag period. The ore-adapted T. thiooxidans extracted Cu as well as T. ferrooxidans, but the extraction of Zn or Fe was still much slower in the low-phosphate medium, while in the high-phosphate medium it approached the value obtained with T. ferrooxidans. A high Cu-Zn extraction ratio of 0.34 was obtained with T. thiooxidans in the low phosphate medium. In the mixed-culture experiments with T. ferrooxidans and T. thiooxidans, the culture behaved as T. thiooxidans in the low-phosphate medium with a higher Cu-Zn extraction ratio and as T. ferrooxidans in the high-phosphate medium with a lower Cu-Zn extraction ratio. It is concluded that T. ferrooxidans and T. thiooxidans solubilize sulfide minerals by different mechanisms.

  1. Purification and characterization of 3-isopropylmalate dehydrogenase from Thiobacillus thiooxidans.

    Science.gov (United States)

    Kawaguchi, H; Inagaki, K; Matsunami, H; Nakayama, Y; Tano, T; Tanaka, H

    2000-01-01

    3-Isopropylmalate dehydrogenase was purified to homogeneity from the acidophilic autotroph Thiobacillus thiooxidans. The native enzyme was a dimer of molecular weight 40,000. The apparent K(m) values for 3-isopropylmalate and NAD+ were estimated to be 0.13 mM and 8.7 mM, respectively. The optimum pH for activity was 9.0 and the optimum temperature was 65 degrees C. The properties of the enzyme were similar to those of the Thiobacillus ferrooxidans enzyme, expect for substrate specificity. T. thiooxidans 3-isopropylmalate dehydrogenase could not utilize malate as a substrate.

  2. Pyrite Surface after Thiobacillus ferrooxidans Leaching at 30℃

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In order to investigate the effect of Thiobacillus ferrooxidans on the oxidation of pyrite, two parallel experiments, which employed H2SO4 solutions and acidic solutions inoculated with Thiobacillus ferrooxidans, were designed and carried out at 30℃. The initial pH of the two solutions was adjusted to 2.5 by dropwise addition of concentrated sulphuric acid. The surfaces of pyrite before exposure to leaching solutions and after exposure to the H2SO4 solutions and acidic solutions inoculated with Thiobacillus ferrooxidans were observed by scanning electron microscopy (SEM). There were a variety of erosion patterns by Thiobacillusferrooxidans on the bio-leached pyrite surfaces. A conclusion can be drawn that the oxidation of pyrite might have been caused by erosion of the surfaces.Attachment of the bacteria to pyrite surfaces resulted in erosion pits, leading to the oxidation of pyrite.It is possible that the direct mechanism plays the most important role in the oxidation of pyrite. The changes in iron ion concentrations of both the experimental solutions with time suggest that Thiobacillus ferrooxidans can enhance greatly the oxidation of pyrite.

  3. Application of Thiobacillus ferroxidans to the bacterial desulfurization of coal; Application du Thiobacillus ferroxidans a la desulfuration bacterienne du charbon

    Energy Technology Data Exchange (ETDEWEB)

    Fecko, P. [Ostrava Universite Technique (Czech Republic); Sedlackova, V. [MUS Republique Tcheque (Czech Republic)

    2001-03-01

    The applicability of bacterial lixiviation of coal is tested on a sample from the Merkur basin (Northern Bohemia, Czech republic). Clean cultures of Thiobacillus ferroxidans can totally remove the pyrite sulfur after one month of treatment. With this process, the desulfurization can reach 48%. Abstract only. (J.S.)

  4. Genome analysis and physiological comparison of Alicycliphilus denitrificans strains BC and K601T

    Energy Technology Data Exchange (ETDEWEB)

    Oosterkamp, Margreet J. [Wageningen University and Research Centre, The Netherlands; Veuskens, Teun [Wageningen University and Research Centre, The Netherlands; Saia, Flavia Talarico [Wageningen University and Research Centre, The Netherlands; Weelink, Sander A.B. [Wageningen University and Research Centre, The Netherlands; Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Daligault, Hajnalka E. [Los Alamos National Laboratory (LANL); Bruce, David [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); Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Langenhoff, A. M. [Deltares, The Netherlands; Gerritse, Jan [Deltares, The Netherlands; Van Berkel, Willem J. H. [Wageningen University and Research Centre, The Netherlands; Pieper, Dietmar [HZI - Helmholtz Centre for Infection Research, Braunschweig, Germany; Junca, Howard [CorpoGen, Bogota Colombia; Smidt, Hauke [Wageningen University and Research Centre, The Netherlands; Schraa, Gosse [Wageningen University and Research Centre, The Netherlands; Davids, Mark [Wageningen University and Research Centre, The Netherlands; Schaap, Peter J [Wageningen University and Research Centre, The Netherlands; Plugge, Caroline M. [Wageningen University and Research Centre, The Netherlands; Stams, Alfons J. M. [Wageningen University and Research Centre, The Netherlands

    2013-01-01

    The genomes of the Betaproteobacteria Alicycliphilus denitrificans strains BC and K601T have been sequenced to get insight into the physiology of the two strains. Strain BC degrades benzene with chlorate as electron acceptor. The cyclohexanol-degrading denitrifying strain K601T is not able to use chlorate as electron acceptor, while strain BC cannot degrade cyclohexanol. The 16S rRNA sequences of strains BC and K601T are identical and the fatty acid methyl ester patterns of the strains are similar. Basic Local Alignment Search Tool (BLAST) analysis of predicted open reading frames of both strains showed most hits with Acidovorax sp. JS42, a bacterium that degrades nitro-aromatics. The genomes include strain-specific plasmids (pAlide201 in strain K601T and pAlide01 and pAlide02 in strain BC). Key genes of chlorate reduction in strain BC were located on a 120 kb megaplasmid (pAlide01), which was absent in strain K601T. Genes involved in cyclohexanol degradation were only found in strain K601T. Benzene and toluene are degraded via oxygenase-mediated pathways in both strains. Genes involved in the meta-cleavage pathway of catechol are present in the genomes of both strains. Strain BC also contains all genes of the ortho-cleavage pathway. The large number of mono- and dioxygenase genes in the genomes suggests that the two strains have a broader substrate range than known thus far.

  5. Genome sequences of Alicycliphilus denitrificans strains BC and K601T

    NARCIS (Netherlands)

    Oosterkamp, M.J.; Veuskens, T.; Plugge, C.M.; Langenhoff, A.A.M.; Gerritsen, J.; Berkel, van W.J.H.; Junca, H.; Smidt, H.; Stams, A.J.M.

    2011-01-01

    Alicycliphilus denitrificans strain BC and A. denitrificans strain K601(T) degrade cyclic hydrocarbons. These strains have been isolated from a mixture of wastewater treatment plant material and benzene-polluted soil and from a wastewater treatment plant, respectively, suggesting their role in biore

  6. 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

  7. Peroxidase activity and involvement in the oxidative stress response of roseobacter denitrificans truncated hemoglobin.

    Directory of Open Access Journals (Sweden)

    Yaya Wang

    Full Text Available Roseobacter denitrificans is a member of the widespread marine Roseobacter genus. We report the first characterization of a truncated hemoglobin from R. denitrificans (Rd. trHb that was purified in the heme-bound form from heterologous expression of the protein in Escherichia coli. Rd. trHb exhibits predominantly alpha-helical secondary structure and absorbs light at 412, 538 and 572 nm. The phylogenetic classification suggests that Rd. trHb falls into group II trHbs, whereas sequence alignments indicate that it shares certain important heme pocket residues with group I trHbs in addition to those of group II trHbs. The resonance Raman spectra indicate that the isolated Rd. trHb contains a ferric heme that is mostly 6-coordinate low-spin and that the heme of the ferrous form displays a mixture of 5- and 6-coordinate states. Two Fe-His stretching modes were detected, notably one at 248 cm-1, which has been reported in peroxidases and some flavohemoglobins that contain an Fe-His-Asp (or Glu catalytic triad, but was never reported before in a trHb. We show that Rd. trHb exhibits a significant peroxidase activity with a (kcat/Km value three orders of magnitude higher than that of bovine Hb and only one order lower than that of horseradish peroxidase. This enzymatic activity is pH-dependent with a pKa value ~6.8. Homology modeling suggests that residues known to be important for interactions with heme-bound ligands in group II trHbs from Mycobacterium tuberculosis and Bacillus subtilis are pointing toward to heme in Rd. trHb. Genomic organization and gene expression profiles imply possible functions for detoxification of reactive oxygen and nitrogen species in vivo. Altogether, Rd. trHb exhibits some distinctive features and appears equipped to help the bacterium to cope with reactive oxygen/nitrogen species and/or to operate redox biochemistry.

  8. [Function of surface membrane structures in Thiobacillus thiooxidans].

    Science.gov (United States)

    Pivovarova, T A; Karavaĭko, G I

    1975-01-01

    The function of the surface membrane structures was studied with cytochemical techniques on ultrathin sections of Thiobacillus thiooxidans. The transport of elementary sulphur inside the cell involves the surface membrane structures, while oxidation of the sulphur to sulphuric acid takes place on the outer surface of the cytoplasmic membrane. The surface membrane structures are supposed also to participate in the primary dissolution of elementary sulphur at the site of contact of the cells with the mineral.

  9. The Impact of Nitrite on Aerobic Growth of Paracoccus denitrificans PD1222

    OpenAIRE

    Hartop, Katherine

    2014-01-01

    The effect of nitrite stress induced in Paracoccus denitrificans PD1222 was examined using additions of sodium nitrite to an aerobic bacterial culture. Nitrite generates a strong stress response in P. denitrificans, causing growth inhibition. This is dependent on both the concentration of nitrite present and the pH. The pH dependent effect of nitrite growth inhibition is likely a result of nitrite and free nitrous acid (FNA; pKa = 3.16) and subsequent reactive nitrogen oxides, ...

  10. Substrate uptake and subcellular compartmentation of anoxic cholesterol catabolism in Sterolibacterium denitrificans.

    Science.gov (United States)

    Lin, Ching-Wen; Wang, Po-Hsiang; Ismail, Wael; Tsai, Yu-Wen; El Nayal, Ashraf; Yang, Chia-Ying; Yang, Fu-Chun; Wang, Chia-Hsiang; Chiang, Yin-Ru

    2015-01-09

    Cholesterol catabolism by actinobacteria has been extensively studied. In contrast, the uptake and catabolism of cholesterol by Gram-negative species are poorly understood. Here, we investigated microbial cholesterol catabolism at the subcellular level. (13)C metabolomic analysis revealed that anaerobically grown Sterolibacterium denitrificans, a β-proteobacterium, adopts an oxygenase-independent pathway to degrade cholesterol. S. denitrificans cells did not produce biosurfactants upon growth on cholesterol and exhibited high cell surface hydrophobicity. Moreover, S. denitrificans did not produce extracellular catabolic enzymes to transform cholesterol. Accordingly, S. denitrificans accessed cholesterol by direction adhesion. Cholesterol is imported through the outer membrane via a putative FadL-like transport system, which is induced by neutral sterols. The outer membrane steroid transporter is able to selectively import various C27 sterols into the periplasm. S. denitrificans spheroplasts exhibited a significantly higher efficiency in cholest-4-en-3-one-26-oic acid uptake than in cholesterol uptake. We separated S. denitrificans proteins into four fractions, namely the outer membrane, periplasm, inner membrane, and cytoplasm, and we observed the individual catabolic reactions within them. Our data indicated that, in the periplasm, various periplasmic and peripheral membrane enzymes transform cholesterol into cholest-4-en-3-one-26-oic acid. The C27 acidic steroid is then transported into the cytoplasm, in which side-chain degradation and the subsequent sterane cleavage occur. This study sheds light into microbial cholesterol metabolism under anoxic conditions.

  11. Electrochemical behavior of chalcopyrite in presence of Thiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    LI Hong-xu; QIU Guan-zhou; HU Yue-hua; CANG Da-qiang; WANG Dian-zuo

    2006-01-01

    The chalcopyrite anode dissolution behavior in the presence or absence of bacteria in 9 K media using bacteria modified powder microelectrode at 30 ℃ was studied. It is found that during the anode dissolution, many intermediate transient reactions occur accompanying with the production of chalcocite and covellite at potential between -0.075 V and -0.025 V (vs SCE). At low scanning potential between -0.1 and -0.250 V, the iron ion is released in ferrous form, but at the relative high potential up to 0.7 V, it is the ferric one. The presence of Thiobacillus ferrooxidans makes peak current increase and the initial peak potential negatively move, hinting the decomposed oxidation reaction easily occurred and especially the iron ion released and ferrous oxidation reaction enhanced. The characteristic at potential between -0.75 and -0.5 V demonstrates the Thiobacillus ferrooxidans also contributes to the element sulfur formed on the oxidation surface and removed during anode process. The added ferric in the cell could enhance the dissolution reaction, while the increased acid under pH=2 might slightly hamper the process. The anode dissolution kinetics studies show that the presence of bacteria could decease corrosion potential from 0.238 V to 0.184 V and increase the corrosion current density from 1.632 14×10-8 A/cm2 to 2.374 11×10-7A/cm2.

  12. Microbiological Denitrification and Denitrifying Activity of Paracoccus Denitrificans

    Institute of Scientific and Technical Information of China (English)

    万曦; 万国江; 等

    2000-01-01

    With rapidly industrial and agricultural development,more and more fertilizers,chemicals and heavy ions will be discharged into lakes and rivers,which would cause lake eutrophication and quality deterioration in drinking water sources.Therefore,denitrification is essential for controlling the amounts of nitrogen,During the transformation process from nitrate to the end products-nitrogen and several intermediated[e.g.nitrite(NO2-),nitrous oxide(N2O) and nitric oxide(NO)]may be accumulated,which have more toxic influences on the environment.in This study,the denitrification effect of Paracoccus Denitrificans was examined on the changes between oxic and anoxic conditions at varying pH.At pH=7.5,denitrification proceeded well after 3 switches from oxic to anoxic conditions and vice versa,Production of N2 was constant and the amounts of NO2-,N2O and NO were extremely low.How ever,at pH=6.8,denitrification activity was inhitied and there large amounts of the intermaediates.The denitrifying bacteria decreased violently in dry weight and were washed out.

  13. Ferrous ion oxidation by Thiobacillus ferrooxidans immobilized on activated carbon

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ji-kui; QIN Wen-qing; NIU Yin-jian; LI Hua-xia

    2006-01-01

    The immobilization of Thiobacillus ferrooxidans on the activated carbon particles as support matrix was investigated. Cycling batch operation results in the complete oxidation of ferrous iron in 8 d when the modified 9 K medium is set to flow through the mini-bioreactor at a rate of 0.104 L/h at 25 ℃. The oxidation rate of ferrous iron with immobilized T. ferrooxidans is 9.38 g/(L·h). The results show that the immobilization of T. ferrooxidans on activated carbon can improve the rate of oxidation of ferrous iron. The SEM images show that a build-up of cells of T. ferrooxidans and iron precipitates is formed on the surface of activated carbon particles.

  14. Purificantion and characterization of inorganic pyrophosphatase from Thiobacillus thiooxidans.

    Science.gov (United States)

    Tominaga, N; Mori, T

    1977-02-01

    An inorganic pyrophosphatase [EC 3.6.1.1] was isolated from Thiobacillus thiooxidans and purified 975-fold to a state of apparent homogeneity. The enzyme catalyzed the hydrolysis of inorganic pyrophosphate and no activity was found with a variety of other phosphate esters. The cation Mg2+ was required for maximum activity; Co2+ and Mn2+ supported 25 per cent and 10.6 per cent of the activity with Mg2+, respectively. The pH optimum was 8.8. The molecular weight was estimated to be 88,000 by gel filtration and SDS gel electrophoresis, and the enzyme consisted of four identical subunits. The isoelectric point was found to be 5.05. The enzyme was exceptionally heat-stable in the presence of 0.01 M Mg2+.

  15. Biosorption of Zn(II) by Thiobacillus ferrooxidans

    Energy Technology Data Exchange (ETDEWEB)

    Celaya, R.J.; Noriega, J.A.; Yeomans, J.H.; Ruiz-Manriquez, A. [Dept. de Ingenieria Quimica y Metalurgia, Universidad de Sonora, Hermosillo (Mexico); Ortega, L.J. [Dept. de Biotecnologia y Bioingenieria, Centro de Investigacion y Estudios Avanzados (Mexico)

    2000-06-01

    There have been a number of studies considering the possibility of removing and recovering heavy metals from diluted solutions. These are due, principally, because of the commercial value of some metals as well as in the environmental impact caused by them. The traditional methods for removing have several disadvantages when metals are present in concentrations lower than 100 mg/l. Biosorption, which uses biological materials as adsorbents, has been considered as an alternative method. In this work, variables like pH and biomass chemical pretreatment have been studied for its effect on the capacity for zinc biosorption by Thiobacillus ferrooxidans. Also, studies to determinate the time for zinc adsorption were carried out. Results indicate that a capacity as high as 82.61 mg of Zn(II)/g of dry biomass can be obtained at a temperature of 25 C and that the biosorption process occurs in a time of 30 min. (orig.)

  16. The role of "blebbing" in overcoming the hydrophobic barrier during biooxidation of elemental sulfur by Thiobacillus thiooxidans

    Science.gov (United States)

    Knickerbocker, C.; Nordstrom, D.K.; Southam, G.

    2000-01-01

    Brimstone Basin, in southeastern Yellowstone National Park, Wyoming is an ancient hydrothermal area containing solfataric alteration. Drainage waters flowing from Brimstone Basin had pH values as low as 1.23 and contained up to 1.7×106 MPN/ml acidophilic sulfur-oxidizing bacteria. Thiobacillus thiooxidans was the dominant sulfur-oxidizing bacterium recovered from an enrichment culture and was used in a structural examination of bacterial sulfur oxidation. Growth in these sulfur cultures occurred in two phases with cells in association with the macroscopic sulfur grains and in suspension above these grains. Colonization of sulfur grains by individual cells and microcolonies was facilitated by organic material that appeared to be responsible for bacterial adhesion. Transmission electron microscopy of negatively stained (2% [wt./vol.] uranyl acetate), sulfur-grown T. thiooxidans revealed extensive membrane blebbing (sloughing of outer membrane vesicles) and the presence of approximately 100 nm sized sulfur particles adsorbed to membrane material surrounding individual bacteria. Sulfite-grown bacteria did not possess membrane blebs. The amphipathic nature of these outer membrane vesicles appear to be responsible for overcoming the hydrophobic barrier necessary for the growth of T. thiooxidans on elemental sulfur.

  17. Differentiation of Kingella denitrificans from Neisseria gonorrhoeae by growth on a semisolid medium and sensitivity to amylase.

    Science.gov (United States)

    Odugbemi, T; Arko, R J

    1983-01-01

    All 239 strains of Neisseria gonorrhoeae tested for sensitivity to amylase-impregnated disks showed zones of growth inhibition ranging from 15 to 30 mm in diameter. None of 52 strains of Kingella denitrificans were inhibited by the same amylase test. In addition, all N. gonorrhoeae strains grew well on a gonococcal base medium supplemented with either IsoVitaleX (BBL Microbiology Systems) or Supplement B (Difco Laboratories), whereas K. denitrificans grew adequately only on the medium with IsoVitaleX. The addition of L-cysteine or cystine to the medium with Supplement B enhanced the growth of K. denitrificans. Images PMID:6187768

  18. Research on optimal domestication of thiobacillus ferooxidans and desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Gong, G.; Tao, X.; Zhang, X.; ??? Luo, Z. [China University of Mining and Technology, Xuzhou (China)

    2006-07-15

    In order to increase the efficiency of biodesulfurization and reduce the reaction time, based on the high selectivity adsorption and oxidation characteristic of thiobacillus ferooxidans (T.f.) for pyrite (FeS{sub 2}) in coal, the strain of T.f. was acclimatized by changing concentration of Fe{sup 2+}, H{sup +} and NH{sub 4}{sup +} and adding FeS{sub 2} and glucose in the 9 K medium. The optimal conditions of growth were investigated and used in the biodesulfurization experiments. The results show that the normal growth of T.f. was achieved after two turns of acclimatization. The desulfurization efficiency is the best under the conditions of 10% inoculation, 1.85 pH value and 27{sup o}C. The smaller the size of coal particle is, the effective the biodesulfurization is. The maximum sulphur removal from coal of 76.2% was obtained after reaction time of 7 days. The mechanisms of desulfurization with T.f. can be explained by the cooperation reaction of dissolved oxygen, bacteria and Fe{sup 3+}. 9 refs., 6 figs.

  19. Mechanism of bioleaching of coal fly ash by Thiobacillus thiooxidans

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, A.; Zimmels, Y.; Armon, R. [Technion Israel Institute of Technology, Haifa (Israel). Faculty of Civil Engineering

    2001-06-15

    Bioleaching of aluminum and iron from coal fly ash (CFA) by Thiobacillus thiooxidans (T thiooxidans) bacteria is considered. The interactions between bacteria, metabolic products, CFA particles, and leaching products were studied. It is demonstrated that bacterial growth and the amount of metals leached from the CFA are coupled through biological and chemical interactions, which involve the various components in this system. Bioleaching experiments were performed batch wise by suspending up to 10% (w/v) CFA in T thiooxidans growth medium containing cell inoculum for a typical 3 week period of time. The results show that under the same conditions, similar leaching levels are obtained by sulfuric acid and bioleaching of CFA, and the contribution of other metabolites is insignificant. CFA inhibits the growth rate through two major effects. The first is due to the alkaline components released by the CFA that cause a rise in the pH, and a corresponding delay in growth. The second is attributed to the random attachment of the bacteria to both the sulfur particles (the energy source) and the barren CFA particles, resulting in a so-called 'dilution effect' of the sulfur particles, and an inhibition of the initial growth rate. However, after an adaptation period of the bacteria the subsequent growth rate, the maximal cell concentration and minimal pH were similar to those obtained in the control experiment, irrespective of CFA content.

  20. Corrosion Behaviors of Steel A3 Exposed to Thiobacillus Ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    Jianhua LIU; Xin LIANG; Songmei LI

    2008-01-01

    The corrosion behaviors of steel A3 in synergistic action of Thiobacillus ferrooxidans (T.f) and electrochemically accelerated corrosion were studied by electrochemical, microbiology and surface analysis methods. The open circuit potential (Eocp) and electrochemical impedance spectroscopy (EIS) of the steel A3 electrodes were measured in leathen culture medium without and with T.f (simply called T.f solution in the following paper)in immersion electrode way at the time of the 2nd, 5th, 10th, 20th and 30th days, respectively. It was found that Eocp of the electrode for immersion in leathen culture medium shifted negatively with the immersion time while that for immersion in T.f solutions shifted negatively, then positively and finally negatively. On the 20th day, the corrosion of steel A3 for immersion in culture medium was in pitting initiation stage while that for immersion in T.f solutions was in pitting growth stage. It was found that the corrosion of steel A3 was accelerated by T.f. The morphology of corrosion product of steel A3 immersion in T.f solutions observed through scanning electron microscopy (SEM) transformed from solid globules to tabular plates and to spongy globules and plates.

  1. Reduction of chromium (VI by the indirect action of Thiobacillus thioparus

    Directory of Open Access Journals (Sweden)

    E. Donati

    2003-03-01

    Full Text Available The microbial reduction of chromium(VI to chromium(III has been one of the most widely studied forms of metal bioremediation. Recently, we have found that Thiobacillus ferrooxidans and Thiobacillus thiooxidans, growing on elemental sulphur, can indirectly promote chromium(VI reduction by producing reducing agents such as sulphite and thiosulphate, which abiotically reduce chromium(VI. Those species of Thiobacillus are acidophilic bacteria which grow optimally at pH values lower than 4. However, most of those reducing agents are stabilised at higher pH values. Thus, the present paper reports on the ability to reduce chromium(VI using another specie of Thiobacilli, Thiobacillus thioparus, which is able to grow at pH close to 7.0. T. thioparus cultures were carried out in a fermentation vessel containing medium and sulphur as the sole energy source and maintained at 30ºC and 400 rpm. The pH was adjusted to 6.0, 7.0 or 8.0 and maintained with the automatic addition of KOH. Our results show high chromium (VI reduction values (close to 100% at the end of bacterial growth at the three pH values. The results of these experiments are very promising for development of a microbiological process to be used in the detoxification of chromium(VI-polluted effluents.

  2. Dynamic Water Networks in Cytochrome c Oxidase from Paracoccus denitrificans Investigated by Molecular Dynamics Simulations

    OpenAIRE

    Olkhova, Elena; Hutter, Michael C; Lill, Markus A.; Helms, Volkhard; Michel, Hartmut

    2004-01-01

    We present a molecular dynamics study of cytochrome c oxidase from Paracoccus denitrificans in the fully oxidized state, embedded in a fully hydrated dimyristoylphosphatidylcholine lipid bilayer membrane. Parallel simulations with different levels of protein hydration, 1.125 ns each in length, were carried out under conditions of constant temperature and pressure using three-dimensional periodic boundary conditions and full electrostatics to investigate the distribution and dynamics of water ...

  3. Biodegradation of isopropanol by a solvent-tolerant Paracoccus denitrificans strain.

    Science.gov (United States)

    Geng, Yucong; Deng, Yuanjie; Chen, Feilong; Jin, Hong; Tao, Ke; Hou, Taiping

    2015-01-01

    The biodegradation of high concentration isopropanol (2-propanol, IPA) at 16 g/L was investigated by a solvent-tolerant strain of bacteria identified as Paracoccus denitrificans for the first time by 16S rDNA gene sequencing. The strain P. denitrificans GH3 was able to utilize the high concentration of IPA as the sole carbon source within a minimal salts medium with a cell density of 1.5×10(8) cells/mL. The optimal conditions were found as follows: initial pH 7.0, incubation temperature 30°C, with IPA concentration 8 g/L. Under the optimal conditions, strain GH3 utilized 90.3% of IPA in 7 days. Acetone, the major intermediate of aerobic IPA biodegradation, was also monitored as an indicator of microbial IPA utilization. Both IPA and acetone were completely removed from the medium following 216 hr and 240 hr, respectively. The growth of strain GH3 on IPA as a sole carbon and energy source was well described by the Andrews model with a maximum growth rate (μmax)=0.0277/hr, a saturation constant (KS)=0.7333 g/L, and an inhibition concentration (Ki)=8.9887 g/L. Paracoccus denitrificans GH3 is considered to be well used in degrading IPA in wastewater.

  4. Novel Castellaniella denitrificans SA13P as a Potent Malachite Green Decolorizing Strain

    Directory of Open Access Journals (Sweden)

    Ankita Chawla

    2014-01-01

    Full Text Available Triphenylmethane dyes represent a major group of dyes causing serious environmental hazards. Malachite Green is one of the commonly and extensively used triphenylmethane dyes although it is carcinogenic and mutagenic in nature. Various physicochemical methods have been employed for its elimination but are highly expensive, coupled with the formation of huge amount of sludge. Hence, biological methods being ecofriendly are good alternatives. In the present study, the novel bacterial isolate SA13P was isolated from UASB tank of tannery effluent treatment plant. Phylogenetic characterization of 1470 bp fragment of SA13P has revealed its similarity with Castellaniella denitrificans. This strain has been found to decolorize the dye (malachite green at a concentration of 100 mg L−1 (80.29%. Decolorization was done by living bacterial cells rather than adsorption. Growth conditions have also been optimized for the decolorization. Maximum decolorization was observed at a temperature of 37°C and pH 8.0. Also, it has been found that bacterization of seeds of Vigna radiata with Castellaniella denitrificans SA13P increases germination rate. We have reported for the first time that Castellaniella denitrificans SA13P may be used as a novel strain for dye decolorization (malachite green and biological treatment of tannery effluent.

  5. Interactive performances of betaine on the metabolic processes of Pseudomonas denitrificans.

    Science.gov (United States)

    Xia, Wei; Peng, Wei-fu; Chen, Wei; Li, Kun-tai

    2015-02-01

    The performances of betaine on the metabolic processes of vitamin B12-producing Pseudomonas denitrificans were investigated in this paper. The results showed that betaine was an indispensable methyl-group donor for vitamin B12 biosynthesis, but large amounts of the extracellular glycine accompanied by betaine metabolism would impose a severe restriction on the cell growth of P. denitrificans. By further using a comparative metabolomics approach coupled with intracellular free amino acids analysis for the fermentation processes with betaine addition (10 g/l) or not, it was found that betaine could highly strengthen the formation of some key precursors and intermediates facilitating vitamin B12 biosynthesis, such as δ-aminolevulinic acid (ALA, the first precursor of vitamin B12), glutamate (an intermediate of ALA via C5 pathway), glycine (an intermediate of ALA via C4 pathway), and methionine (directly participating in the methylation reaction involved in vitamin B12 biosynthetic pathway). Therefore, the performances of betaine on P. denitrificans metabolic processes were not only serving as a decisive methyl-group donor for vitamin B12 biosynthesis, but also playing a powerfully promoting role in the generation of vitamin B12 precursors and intermediates.

  6. Aplicação de técnicas eletroquímicas no estudo da dissolução oxidativa da covelita (CuS por Thiobacillus ferrooxidans Electrochemical techniques applied to study the oxidative dissolution of the covellite: CuS by Thiobacillus ferrooxidans

    Directory of Open Access Journals (Sweden)

    Christiane Medina Teixeira

    2002-02-01

    Full Text Available Among the copper sulphides, chalcopyrite (CuFeS2, covellite (CuS and chalcocite (Cu2S are the most important source of minerals for copper mining industry. The acknowledge of behaviour of these sulphides related with bacterial leaching process are essential for optimization procedures. Despite of its importance, covellite has not deserved much interest of researchers regarding this matter. In this work it was studied the oxidation of covellite by the chemolithotrophic bacterium Thiobacillus ferrooxidans by using electrochemical techniques, such as open circuit potentials with the time and cyclic voltammetry. The experiments were carried out in acid medium (pH 1.8, containing or not Fe2+ as additional energy source, and in different periods of incubation; chemical controls were run in parallel. The results showed that a sulphur layer is formed spontaneously due the acid attack, covering the sulphide in the initial phase of incubation, blocking the sulphide oxidation. However, the bacterium was capable to oxidize this sulphur layer. In the presence of Fe2+ as supplemental energy source, the corrosion process was facilitated, because ocurred an indirect oxidation of covellite by Fe3+, which was produced by T. ferrooxidans oxidation of the Fe2+ added in the medium.

  7. Molecular biological enhancement of coal biodesulfurization. [Rhodococcus, thiobacillus

    Energy Technology Data Exchange (ETDEWEB)

    Litchfield, J.H.; Fry, I.; Wyza, R.E.; Palmer, D.T.; Zupancic, T.J.; Conkle, H.N.

    1990-06-14

    The objective of this project is to produce one or more microorganisms capable of removing the organic and inorganic sulfur in coal. The original specific technical objectives of the project were to: clone and characterize the genes encoding the enzymes of the 4S'' pathway (sulfoxide/sulfone/sulfonate/sulfate) for release of organic sulfur from coal; return multiple copies of genes to the original host to enhance the biodesulfurization activity of that organism; transfer this pathway into a fast-growing chemolithotropic bacterium; conduct a batch-mode optimization/analysis of scale-up variables.

  8. Molecular biological enhancement of coal biodesulfurization. [Thiobacillus cuprinus

    Energy Technology Data Exchange (ETDEWEB)

    Litchfield, J.H.; Zupancic, T.J.; Baker, B.; Palmer, D.T.; Fry, I.J.; Tranuero, C.G.; Wyza, R.E.; Schweitzer, A.; Conkle, H.N. (Battelle, Columbus, OH (United States)); Chakravanty, L.; Tuovinen, O.H. (Ohio State Univ., Columbus, OH (United States))

    1991-09-13

    The objective of this project is to produce one or more microorganisms capable of removing the organic and inorganic sulfur in coal. The original specific technical objectives of the project were to: clone and characterize the genes encoding the enzymes of the 4S'' pathway (sulfoxide/sulfone/sulfonate/sulfate) for release of organic sulfur from coal; return multiple copies of genes to the original host to enhance the biodesulfurization activity of that organism; transfer this pathway into a fast-growing chemolithotropic bacterium; conduct a batch-mode optimization/analysis of scale-up variables.

  9. The role of sulfur-oxidizing bacteria Thiobacillus thiooxidans in pyrite weathering

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, K.; Tsunekawa, M.; Ohtsuka, T.; Konno, H. [Hokkaido University, Sapporo (Japan). Graduate School of Engineering

    1998-02-28

    The paper investigates the role of the sulfur-oxidizing bacteria Thiobacillus thiooxidans in pyrite weathering in order to clarify the effects of the bacteria on the dissolution behavior of pyrite and the formation of secondary minerals using Raman spectroscopy and powder X-ray diffraction (XRD) in addition to solution analysis. It was found that T. thiooxidans, when present with the iron-oxidizing bacteria Thiobacillus ferrooxidans, enhanced the dissolution of Fe and S species for pyrite, whereas T. thiooxidans alone did not oxidize pyrite. Enhancement of the consumption of elemental sulfur and regeneration of Fe(II) ions were also observed with T. thiooxidans together with T. ferrooxidans, while this did not occur with T. ferrooxidans alone.

  10. Heavy metal resistance of Thiobacillus spp. isolated from tin mining area in Bestari Jaya, Selangor

    Science.gov (United States)

    Prabhakaran, Pranesha; Ashraf, Muhammad Aqeel; Aqma, Wan Syaidatul

    2016-11-01

    Increased anthropogenic activities such as mining have contributed to accumulation of heavy metals in the environment. Microorganisms that are found in the contaminated area develop resistance toward the heavy metals after a prolonged exposure. Screenings for bacterial resistance to metal tin were conducted using isolated Thiobacillus spp. from a tin mining area at Bestari Jaya, Selangor. Two isolated Thiobacillus spp. able to show growth without inhibition up to 300 ppm. IC50 that indicate 50% inhibition of the bacterial growth for both isolates, TB1 and TB2 are 496.03 ppm and 514.27 ppm respectively under tin-stressed condition. Adaptation of these microorganisms toward heavy metal could be exploited for bioremediation of heavy metals at contaminated sites.

  11. [Research on anti-corrosion of Thiobacillus for the geopolymer solidification MSWI fly ash].

    Science.gov (United States)

    Jin, Man-Tong; Sun, Xin; Dong, Hai-Li; Jin, Zan-Fang

    2012-09-01

    In order to discuss the anti-Thiobacillus corrosion performance of geopolymer solidification MSWI fly ash, the research simulated the Thiobacillus corrosion process by experiment, investigated the change of mass, compressive strength, leaching concentration. The results showed that geopolymer had a good anti-corrosion ability: weight loss within 1%, the compressive strength still reached 21.88 MPa after 28 days, the corrosion resistance coefficient was above 0.9. The maximum leaching concentration of Cr, Cu, Zn, Cd, Hg, Pb were 107.7 microg x L(-1), 22.71 microg x L(-1), 39.18 microg x L(-1), 0.56 microg x L(-1), 34.84 microg x L(-1) and 3.03 microg x L(-1), respectively. And the leaching concentration of geopolymer reduced with the immersion time, showed a good anti-Thiobacillus corrosion performance. Through the X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscope spectra of geopolymer, we investigated the microstructure and mechanism of geopolymer anti-corrosion.

  12. PERFORMANCE OF A BIOTRICKLING FILTER EMPLOYING THIOBACILLUS THIOPARUS IMMOBILIZED ON POLYURETHANE FOAM FOR HYDROGEN SULFIDE REMOVAL

    Directory of Open Access Journals (Sweden)

    N. Abdehagh

    2011-09-01

    Full Text Available The removal of hydrogen sulfide (H2S from contaminated airstream was studied in a biotrickling filter (BTF packed with open-pore polyurethane foam as a carrier of Thiobacillus thioparus (DSMZ5368 with counter current gas/liquid flows. The effect of operating parameters on BTF performance was studied. Experiments were performed at different Empty Bed Residence Times (EBRT from 9 to 45 seconds, and different initial H2S concentration from 25 to 85 ppm. The results showed reasonable performance of the BTF, in H2S removal from the synthetic gas stream. However, the performance was somewhat lower than other studies in BTF in which either Thiobacillus thioparus with other packings or polyurethane foam with other microbial cultures were used. The effect of liquid recirculation rate (LRR in the range of 175-525 ml/min (0.46-1.34 m/h on BTF performance was also studied. Results showed that increasing LRR from 175 to 350 mL/min resulted in significant enhancement of H2S removal efficiency, but further increase in LRR up to 525 mL/min had an insignificant effect. H2S elimination at different heights of the bed was studied and it was found that decrease in EBRT results in more homogeneous removal of the pollutant in BTF. Determination of microbial species in the BTF after 100 days performance showed that during BTF operation the only H2S degrading specie was Thiobacillus thioparus.

  13. Linking TFT-LCD wastewater treatment performance to microbial population abundance of Hyphomicrobium and Thiobacillus spp.

    Science.gov (United States)

    Fukushima, Toshikazu; Whang, Liang-Ming; Chen, Po-Chun; Putri, Dyah Wulandari; Chang, Ming-Yu; Wu, Yi-Ju; Lee, Ya-Ching

    2013-08-01

    This study investigated the linkage between performance of two full-scale membrane bioreactor (MBR) systems treating thin-film transistor liquid crystal display (TFT-LCD) wastewater and the population dynamics of dimethylsulfoxide (DMSO)/dimethylsulfide (DMS) degrading bacteria. High DMSO degradation efficiencies were achieved in both MBRs, while the levels of nitrification inhibition due to DMS production from DMSO degradation were different in the two MBRs. The results of real-time PCR targeting on DMSO/DMS degrading populations, including Hyphomicrobium and Thiobacillus spp., indicated that a higher DMSO oxidation efficiency occurred at a higher Hyphomicrobium spp. abundance in the systems, suggesting that Hyphomicrobium spp. may be more important for complete DMSO oxidation to sulfate compared with Thiobacillus spp. Furthermore, Thiobacillus spp. was more abundant during poor nitrification, while Hyphomicrobium spp. was more abundant during good nitrification. It is suggested that microbial population of DMSO/DMS degrading bacteria is closely linking to both DMSO/DMS degradation efficiency and nitrification performance.

  14. Isolation and analysis of the genes for cytochrome c oxidase in Paracoccus denitrificans

    OpenAIRE

    Raitio, Mirja; Jalli, Tuulikki; Saraste, Matti

    1987-01-01

    Synthetic oligonucleotide probes were used to clone two loci from the chromosomal DNA of Paracoccus denitrificans that contain the genes for cytochrome c oxidase (cytochrome aa3). One locus seems to contain four or five genes probably forming an operon. Two of these code for the oxidase subunits II and III. Three open reading frames are found between the COII and COIII genes. The other locus codes for the subunit I. A short open reading frame is found upstream of this gene. All three subunits...

  15. Efficacy of chalcopyrite bioleaching using a pure and a mixed bacterium

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    To determine the efficacy of chalcopyrite bioleaching using pure cultures of Thiobacillus ferrooxidans or Thiobacillus thiooxidans and a mixed culture composed of Thiobacillus ferrooxidans and Thiobacillus thiooxidans, experiments were carried out mixed culture composed of Thiobacillusferrooxidans and Thiobacillus thiooxidans is higher than that in a pure culture. On the other hand, an important potential of Thiobacillus thiooxidans to leaching chalcopyrite was indicated. Thiobacillus thiooxidans can prevent jarosites accumulating on the substrate and allow further copper to dissolute through the action of ferric ion. The selection of the suitable pH in a leaching solution would be significant. Thiobacillus thiooxidans and Thiobacillus ferrooxidans play an important role in the bioleaching process. Finally, the mechanism and the reason for iron precipitation were also discussed in detail.

  16. Achromobactor denitrificans SP1 produces pharmaceutically active 25C prodigiosin upon utilizing hazardous di(2-ethylhexyl)phthalate

    Science.gov (United States)

    Achromobacter denitrificans SP1 isolated from soil sludge heavily contaminated with plastic waste produced a novel pharmaceutically-active 25C prodigiosin analog during growth in a simple mineral salt medium supplemented with hazardous di(2-ethylhexyl)phthalate (DEHP) blended PVC plastics (in situ) ...

  17. Co-Cultures of Pseudomonas aeruginosa and Roseobacter denitrificans Reveal Shifts in Gene Expression Levels Compared to Solo Cultures

    Directory of Open Access Journals (Sweden)

    Crystal A. Conway

    2012-01-01

    Full Text Available Consistent biosynthesis of desired secondary metabolites (SMs from pure microbial cultures is often unreliable. In a proof-of-principle study to induce SM gene expression and production, we describe mixed “co-culturing” conditions and monitoring of messages via quantitative real-time PCR (qPCR. Gene expression of model bacterial strains (Pseudomonas aeruginosa PAO1 and Roseobacter denitrificans Och114 was analyzed in pure solo and mixed cocultures to infer the effects of interspecies interactions on gene expression in vitro, Two P. aeruginosa genes (PhzH coding for portions of the phenazine antibiotic pathway leading to pyocyanin (PCN and the RhdA gene for thiosulfate: cyanide sulfurtransferase (Rhodanese and two R. denitrificans genes (BetaLact for metallo-beta-lactamase and the DMSP gene for dimethylpropiothetin dethiomethylase were assessed for differential expression. Results showed that R. denitrificans DMSP and BetaLact gene expression became elevated in a mixed culture. In contrast, P. aeruginosa co-cultures with R. denitrificans or a third species did not increase target gene expression above control levels. This paper provides insight for better control of target SM gene expression in vitro and bypass complex genetic engineering manipulations.

  18. Paracoccus denitrificans possesses two BioR homologs having a role in regulation of biotin metabolism.

    Science.gov (United States)

    Feng, Youjun; Kumar, Ritesh; Ravcheev, Dmitry A; Zhang, Huimin

    2015-08-01

    Recently, we determined that BioR, the GntR family of transcription factor, acts as a repressor for biotin metabolism exclusively distributed in certain species of α-proteobacteria, including the zoonotic agent Brucella melitensis and the plant pathogen Agrobacterium tumefaciens. However, the scenario is unusual in Paracoccus denitrificans, another closely related member of the same phylum α-proteobacteria featuring with denitrification. Not only does it encode two BioR homologs Pden_1431 and Pden_2922 (designated as BioR1 and BioR2, respectively), but also has six predictive BioR-recognizable sites (the two bioR homolog each has one site, whereas the two bio operons (bioBFDAGC and bioYB) each contains two tandem BioR boxes). It raised the possibility that unexpected complexity is present in BioR-mediated biotin regulation. Here we report that this is the case. The identity of the purified BioR proteins (BioR1 and BioR2) was confirmed with LC-QToF-MS. Phylogenetic analyses combined with GC percentage raised a possibility that the bioR2 gene might be acquired by horizontal gene transfer. Gel shift assays revealed that the predicted BioR-binding sites are functional for the two BioR homologs, in much similarity to the scenario seen with the BioR site of A. tumefaciens bioBFDAZ. Using the A. tumefaciens reporter system carrying a plasmid-borne LacZ fusion, we revealed that the two homologs of P. denitrificans BioR are functional repressors for biotin metabolism. As anticipated, not only does the addition of exogenous biotin stimulate efficiently the expression of bioYB operon encoding biotin transport/uptake system BioY, but also inhibits the transcription of the bioBFDAGC operon resembling the de novo biotin synthetic pathway. EMSA-based screening failed to demonstrate that the biotin-related metabolite is involved in BioR-DNA interplay, which is consistent with our former observation with Brucella BioR. Our finding defined a complex regulatory network for biotin

  19. Transfer of IncP Plasmids to Extremely Acidophilic Thiobacillus thiooxidans

    OpenAIRE

    Jin, S. M.; Yan, W. M.; Wang, Z. N.

    1992-01-01

    The broad-host-range IncP plasmids RP4, R68.45, RP1::Tn501, and and pUB307 were transferred directly to extremely acidophilic Thiobacillus thiooxidans from Escherichia coli by conjugation at frequencies of 10-5 to 10-7 per recipient. The ability of T. thiooxidans to receive and express the antibiotic resistance markers was examined. The plasmid RP4 was transferred back to E. coli from T. thiooxidans at a frequency of 1.0 × 10-3 per recipient.

  20. Transfer of IncP Plasmids to Extremely Acidophilic Thiobacillus thiooxidans.

    Science.gov (United States)

    Jin, S M; Yan, W M; Wang, Z N

    1992-01-01

    The broad-host-range IncP plasmids RP4, R68.45, RP1::Tn501, and and pUB307 were transferred directly to extremely acidophilic Thiobacillus thiooxidans from Escherichia coli by conjugation at frequencies of 10 to 10 per recipient. The ability of T. thiooxidans to receive and express the antibiotic resistance markers was examined. The plasmid RP4 was transferred back to E. coli from T. thiooxidans at a frequency of 1.0 x 10 per recipient.

  1. Occurrences at mineral-bacteria interface during oxidation of arsenopyrite by Thiobacillus ferrooxidans

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, M.G.M. [Univ. Autonoma de San Luis Potosi (Mexico). Inst. de Metalurgia; Mustin, C.; Berthelin, J. [Univ. Henri Poincare, Vandoeuvre-les-Nancy (France). Centre de Pedologie Biologique; Donato, P. de; Barres, O.; Marion, P. [I.N.P.L.-E.N.S.G., Vandoeuvre-les-Nancy (France)

    1995-04-05

    The combination of an improved bacterial desorption method, scanning electron microscopy (SEM), diffuse reflectance and transmission infrared Fourier transform spectroscopy, and a desorption-leaching device like high-pressure liquid chromatography (HPLC) was used to analyze bacterial populations and surface-oxidized phases during the arsenopyrite biooxidation by Thiobacillus ferrooxidans. The bacterial distribution, the physicochemical composition of the leachate, the evolution of corrosion patterns, and the nature and amount of the surface-oxidized chemical species characterized different behavior for each step of arsenopyrite bioleaching.

  2. A simple medium modification for isolation, growth and enumeration of Acidithiobacillus thiooxidans (syn. Thiobacillus thiooxidans) from water samples.

    Science.gov (United States)

    Starosvetsky, Janeta; Zukerman, Udy; Armon, Robert H

    2013-02-15

    High concentrations of H(2)S in groundwater are commonly removed using Biological Trickling Filter (BTF) that contains high numbers of biofilm immobilized sulfur oxidizing bacteria (mainly Thiobacillus thiooxidans). BTF performance requires continuous monitoring of these bacteria at several sampling points. The Most Probable Number (MPN) technique is at the moment the method of choice to enumerate viable T. thiooxidan cells under the above conditions. However, this method is extremely time-consuming (7-10days) and not always suitable for environmental monitoring. In the present study, Thiobacillus agar recommended for isolation and cultivation of Thiobacillus species by Spread plate method was modified by addition of bromocresol green (BCG) in order obtain a clear-cut resolution of the growing colonies resulting in similar or higher numbers compared to other methods. Visual emergence of bacterial colonies on the 3rd and 4th days, from the initial plating, was associated with sulfuric acid production, resulting in an unambiguous color change from blue to yellow, around each colony. This study revealed that BCG modified Thiobacillus agar is substantially time saving and much easier to infer compared to MPN technique.

  3. Removal of methanethiol, dimethyl sulfide, dimethyl disulfide, and hydrogen sulfide from contaminated air by Thiobacillus thioparus TK-m.

    OpenAIRE

    Kanagawa, T; Mikami, E.

    1989-01-01

    Methanethiol, dimethyl sulfide, dimethyl disulfide, and hydrogen sulfide were efficiently removed from contaminated air by Thiobacillus thioparus TK-m and oxidized to sulfate stoichiometrically. More than 99.99% of dimethyl sulfide was removed when the load was less than 4.0 g of dimethyl sulfide per g (dry cell weight) per day.

  4. Electronic and vibrational spectroscopy of the cytochrome c:cytochrome c oxidase complexes from bovine and Paracoccus denitrificans.

    OpenAIRE

    Lynch, S. R.; Copeland, R. A.

    1992-01-01

    The 1:1 complex between horse heart cytochrome c and bovine cytochrome c oxidase, and between yeast cytochrome c and Paracoccus denitrificans cytochrome c oxidase have been studied by a combination of second derivative absorption, circular dichroism (CD), and resonance Raman spectroscopy. The second derivative absorption and CD spectra reveal changes in the electronic transitions of cytochrome a upon complex formation. These results could reflect changes in ground state heme structure or chan...

  5. Isolation of a Sulfur-oxidizing Bacterium That can Grow under Alkaline pH, from Corroded Concrete.

    Science.gov (United States)

    Maeda, T; Negishi, A; Oshima, Y; Nogami, Y; Kamimura, K; Sugio, T

    1998-01-01

    To study the early stages of concrete corrosion by bacteria, sulfur-oxidizing bacterium strain RO-1, which grows in an alkaline thiosulfate medium (pH 10.0) was isolated from corroded concreate and characterized. Strain RO-1 was a Gram negative, rod-shaped bacterium (0.5-0.6×0.9-1.5 μm). The mean G+C content of the DNA of strain RO-1 was 65.0 mol%. Optimum pH and temperature for growth were 8.0. and 30-37°C, respectively. When grown in thiosulfate medium with pH 10.0, growth rate of the strain was 48% of that observed at the optimum pH for growth. Strain RO-1 used sulfide, thiosulfate, and glucose, but not elemental sulfur or tetrathionate, as a sole energy source. Strain RO-1 grew under anaerobic conditions in pepton-NO3 (-) medium containing sodium nitrate as an electron acceptor, and had enzyme activities that oxidized sulfide, elemental sulfur, thiosulfate, sulfite, and glucose, but not tetrathionate. The bacterium had an activity to assimilate (14)CO2 into the cells when thiosulfate was used as an energy source. These results suggest that strain RO-1 is Thiobacillus versutus. Strain RO-1 exuded Ca(2+) from concrete blocks added to thiosulfate medium with pH 9.0 and the pH of the medium decreased from 9.0 to 5.5 after 22 days of cultivation. In contrast, Thiobacillus thiooxidans strain NB1-3 could not exude Ca(2+) in the same thiosulfate medium, suggesting that strain RO-1, but not T. thiooxidans NB1-3, is involved in the early stage of concrete corrosion because concrete structures just after construction contain calcium hydroxide and have a pH of 12-13.

  6. The Investigation of the Colony Isolation of Thiobacillus Ferrooxidans%氧化亚铁硫杆菌的菌落分离研究

    Institute of Scientific and Technical Information of China (English)

    张在海; 邱冠周; 胡岳华; 柳建设

    2001-01-01

    以琼脂为凝固剂,研究了亚铁含量、磷酸盐含量、pH值 、添加硫氰酸钾对氧化亚铁硫杆菌菌落产生的影响和细菌的再培养。结果表明培养基能否有 效供给酸耗用酸,使凝固剂不被酸降解(胨化),使细菌能够稳定固着生长、繁殖是菌落产生 的关键条件。控制好这些条件,可以使菌落数量比9K固体培养基提高近两个数量级。%The effect of contents of ferrous ion and phosphate salt,pH,and potassium thiocyanate on the colony formation of Thiobacillus ferrooxidans and the subculture of the bacterrium in the presence of agar as solidifying agent have been investigated.The results have showed that the critical condition for the colony formation is whether the culture medium can steadly supply the acid for baterial oxidation to prevent agar from peptoned and keep invariable pH for the inoculum,in which the bacterium can stably anchorage on the medium for growth and multiplication;and controlling these conditions,the number of colonies can be two orders of magnitude larger than 9K solid medium.

  7. The Effect of Inoculants of Thiobacillus and Aspergillus on Corn Growth

    Directory of Open Access Journals (Sweden)

    M. Mohammdi Aria

    2011-01-01

    Full Text Available Abstract Phosphorus (P is one of the essential macronutrients for growth and development of plant. Phosphorus is added to soil in the form of phosphatic fertilizers, part of which is utilized by plants and the remainder converted into insoluble fixed forms. Increasingly high cost of chemical fertilizers has been the major stimulus to search for an alternative, naturally-occurring, phosphate source. The researchers offered phosphorus rocks as a valuable alternative source for P. fertilizer. Unfortunately, rock phosphate is not plant available in soils with a pH greater than 6. One method to increase soluble form inorganic P is application of phosphate solublizing microorganisms and sulfur oxidizing bacteria (Thiobacillus with rock phosphate. A greenhouse experiment was carried out with two bio fertilizers (bio fertilizers santes in incubation condition in a soil with low available P on corn growth. The bio fertilizers were: rock phosphate with 20% sulfur, 15% vermicompost, Thiobacillus bacteria and Aspergillus fungi (BFS20V15 at three rates: 440 kg/ha (BF1 , 880 kg/ha (BF2, 1320kg/ha (BF3, rock phosphate with 20% sulfur, 15% vermicompost, Thiobacillus bacteria (BFS20V15 at three rates: 440 kg/ha (B1 , 880 kg/ha (B2, 1320kg/ha (B3, triple super phosphate (TSP, and control without phosphorus. In the greenhouse experiment, shoot dry matter, p uptake in plant and available p in soil were determined. The results showed that maximum yield obtained from BF3 with the shoot dry weight 7.2 g per plant and with no significant difference in relation to the triple super phosphate (7.5g at 5% level. Also highest rate p-uptake resulted from BF3. There was significant difference between treatment BF3 and TSP on p-uptake. Results indicated that it could be possible to substitute rock phosphate inoculated with sulfur-oxidizing bacteria and phosphorous-solublizing fungus for super phosphate. Keywords: Uptake-p, pH Rock phosphate, Solfur, Vermicompost

  8. Biofilm forming and leaching mechanism during bioleaching chalcopyrite by Thiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    傅建华; 胡岳华; 邱冠周; 柳建设; 徐竞

    2004-01-01

    The mechanism of attachment and leaching of thiobacillus ferrooxcidans (T. f. ) on chalcopyrite were studied. The shaking flasks with bacteria were observed by SEM. The process of T. f attached to the surface of the mineral sample and the biofilm forming were described. The promoting role of the biofilm for bioleaching was discussed. The existence of Fe2+ in the exopolysaccharide layer of T. f was demonstrated by EM(electronic microscope)cell-chemistry analysis. These results show that under the proper growth condition of bacteria, bioleaching of chalcopyrite results in the formation of complete biofilm after 2 - 3 weeks. There are iron ions in the outer layer polymer of T. f. , which provides the micro-environment for themselves, and can guaruntee the energy needed for the bacteria growth in the biofilm. At the same time, Fe3+ ions produced oxidize sulfide which brings about the increase of both growth rate of the bacterial and leaching rate of sulfide minerals.

  9. The interpretation of the mass spectrum of an ornithine-containing lipid from Thiobacillus thiooxidans.

    Science.gov (United States)

    Hilker, D R; Gross, M L; Knocke, H W; Shively, J M

    1978-01-01

    The electron impact mass spectrum of a previously identified ornithine-containing lipid from Thiobacillus thiooxidans has been interpreted using exact mass measurements, low and high energy ionization, and defocused metastable studies. The spectrum, which did not contain a molecular ion for the intact lipid, was consistent with cyclization of the ornithine zwitterionic moiety with elimination of water to give 3[3'-(11,12-methylene-2-hydroxyoctadecanoxy)hexadecanylamine]-2-piperidone. Production of this sufficiently volatile species for mass spectral analysis was accomplished by gentle pyrolysis in the mass spectrometer source. The spectrum can be understood to arise by three primary decompositions which serve to separate the two fatty acid constituents. The remainder of the spectrum is consistent with the expected fragmentations of these constituents.

  10. Pyruvate inhibition of the carbon dioxide fixation of the strict chemolithotroph Thiobacillus thiooxidans.

    Science.gov (United States)

    Butler, R G

    1975-12-01

    A flow-through dialysis system used to decrease the concentrations of toxic organic materials excreted by Thiobacillus thiooxidans permitted an improved efficiency of carbon dioxide fixation when compared with cells taken from the usual shaken culture. The additions of various concentrations of pyruvic acid and succinic acid inhibited growth significantly. Pyruvate at a concentration of 5 X 10(-3) M completely inhibited the respiration of resting cells oxidizing sulfur. The toxicity of pyruvic acid was found to be permanent as evidenced by the inability to obtain satisfactory oxidation rates after washing the exposed cells twice in buffer. Both pyruvate (10(-3) M) and succinate (10(-3) M) inhibited carbon dioxide fixation by 84%.

  11. SEM and AFM images of pyrite surfaces after bioleaching by the indigenous Thiobacillus thiooxidans.

    Science.gov (United States)

    Liu, H-L; Chen, B-Y; Lan, Y-W; Cheng, Y-C

    2003-09-01

    The bioleaching mechanism of pyrite by the indigenous Thiobacillus thiooxidans was examined with the aid of scanning electron microscopy (SEM) and atomic force microscopy (AFM) images of the pyrite surface. The presence of pyrite eliminated the lag phase during growth of this microorganism. This was due to the stimulatory effect on cell growth of the slight amount of Cu2+ that had leached from the pyrite. Zn2+ was found to be much more readily solubilized than Cu2+. The efficiency of bioleaching was four times higher than that of chemical leaching. SEM images provided evidence of direct cell attachment onto the pyrite surface, thereby enhancing the bioleaching rate. Furthermore, extracellular polymeric substances (EPSs) were found on the pyrite surface after 4 days of oxidation. AFM images showed that the pyrite surface area positively correlated with the oxidation rate. A combination of direct and indirect mechanism is probably responsible for the oxidation of pyrite by T. thiooxidans.

  12. Studies on the Glutathione-Dependent Formaldehyde-Activating Enzyme from Paracoccus denitrificans

    Science.gov (United States)

    Hopkinson, Richard J.; Leung, Ivanhoe K. H.; Smart, Tristan J.; Rose, Nathan R.; Henry, Luc; Claridge, Timothy D. W.; Schofield, Christopher J.

    2015-01-01

    Formaldehyde is a toxin and carcinogen that is both an environmental pollutant and an endogenous metabolite. Formaldehyde metabolism, which is probably essential for all aerobic cells, likely proceeds via multiple mechanisms, including via a glutathione-dependent pathway that is widely conserved in bacteria, plants and animals. However, it is unclear whether the first step in the glutathione-dependent pathway (i.e. formation of S-hydroxymethylglutathione (HMG)) is enzyme-catalysed. We report studies on glutathione-dependent formaldehyde-activating enzyme (GFA) from Paracoccus denitrificans, which has been proposed to catalyse HMG formation from glutathione and formaldehyde on the basis of studies using NMR exchange spectroscopy (EXSY). Although we were able to replicate the EXSY results, time course experiments unexpectedly imply that GFA does not catalyse HMG formation under standard conditions. However, GFA was observed to bind glutathione using NMR and mass spectrometry. Overall, the results reveal that GFA binds glutathione but does not directly catalyse HMG formation under standard conditions. Thus, it is possible that GFA acts as a glutathione carrier that acts to co-localise glutathione and formaldehyde in a cellular context. PMID:26675168

  13. Studies on the Glutathione-Dependent Formaldehyde-Activating Enzyme from Paracoccus denitrificans.

    Directory of Open Access Journals (Sweden)

    Richard J Hopkinson

    Full Text Available Formaldehyde is a toxin and carcinogen that is both an environmental pollutant and an endogenous metabolite. Formaldehyde metabolism, which is probably essential for all aerobic cells, likely proceeds via multiple mechanisms, including via a glutathione-dependent pathway that is widely conserved in bacteria, plants and animals. However, it is unclear whether the first step in the glutathione-dependent pathway (i.e. formation of S-hydroxymethylglutathione (HMG is enzyme-catalysed. We report studies on glutathione-dependent formaldehyde-activating enzyme (GFA from Paracoccus denitrificans, which has been proposed to catalyse HMG formation from glutathione and formaldehyde on the basis of studies using NMR exchange spectroscopy (EXSY. Although we were able to replicate the EXSY results, time course experiments unexpectedly imply that GFA does not catalyse HMG formation under standard conditions. However, GFA was observed to bind glutathione using NMR and mass spectrometry. Overall, the results reveal that GFA binds glutathione but does not directly catalyse HMG formation under standard conditions. Thus, it is possible that GFA acts as a glutathione carrier that acts to co-localise glutathione and formaldehyde in a cellular context.

  14. Phospholipid Fatty Acids as Physiological Indicators of Paracoccus denitrificans Encapsulated in Silica Sol-Gel Hydrogels

    Directory of Open Access Journals (Sweden)

    Josef Trögl

    2015-02-01

    Full Text Available The phospholipid fatty acid (PLFA content was determined in samples of Paracoccus denitrificans encapsulated in silica hydrogel films prepared from prepolymerized tetramethoxysilane (TMOS. Immediately after encapsulation the total PLFA concentration was linearly proportional to the optical density (600 nm of the input microbial suspension (R2 = 0.99. After 7 days this relationship remained linear, but with significantly decreased slope, indicating a higher extinction of bacteria in suspensions of input concentration 108 cells/mL and higher. trans-Fatty acids, indicators of cytoplasmatic membrane disturbances, were below the detection limit. The cy/pre ratio (i.e., ratio of cyclopropylated fatty acids (cy17:0 + cy19:0 to their metabolic precursors (16:1ω7 + 18:1ω7, an indicator of the transition of the culture to a stationary growth-phase, decreased depending on co-immobilization of nutrients in the order phosphate buffer > mineral medium > Luria Broth rich medium. The ratio, too, was logarithmically proportional to cell concentration. These results confirm the applicability of total PLFA as an indicator for the determination of living biomass and cy/pre ratio for determination of nutrient limitation of microorganisms encapsulated in sol-gel matrices. This may be of interest for monitoring of sol-gel encapsulated bacteria proposed as optical recognition elements in biosensor construction, as well as other biotechnological applications.

  15. Investigating the nitrification and denitrification kinetics under aerobic and anaerobic conditions by Paracoccus denitrificans ISTOD1.

    Science.gov (United States)

    Medhi, Kristina; Singhal, Anjali; Chauhan, D K; Thakur, Indu Shekhar

    2017-03-16

    Municipal wastewater contains multiple nitrogen contaminants such as ammonia, nitrate and nitrite. Two heterotrophic nitrifier and aerobic denitrifiers, bacterial isolates ISTOD1 and ISTVD1 were isolated from domestic wastewater. On the basis of removal efficiency of ammonia, nitrate and nitrite under both aerobic and anaerobic conditions, ISTOD1 was selected and identified as Paracoccus denitrificans. Aerobically, NH4(+)-N had maximum specific nitrogen removal rate (Rxi) of 7.6g/gDCW/h and anaerobically, NO3(-)N showed Rxi of 2.5*10(-1)g/g DCW/h. Monod equation described the bioprocess kinetic coefficients, µmax and Ks, obtained by regression. Error functions were calculated to validate the Monod equation experimental data. Aerobic NO3(-)N showed the highest YW of 0.372mg DCW/mg NO3(-)N among the five conditions. ISTOD1 serves as a potential candidate for treating nitrogen rich wastewater using simultaneous nitrification and aerobic denitrification. It can be used in bioaugmentation studies under varied condition.

  16. Submicro-battery effect and selective bio-oxidation model of gold-bearing arsenopyrite by Thiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    杨洪英; 杨立; 赵玉山; 陈刚; 吕久吉; 范有静

    2002-01-01

    Through the study by electronic probe it was found that many new cracks and holes appear on the surface of gold-bearing arsenopyrite crystal oxidized by Thiobacillus ferrooxidans, which are along with some directions. Then the selective bio-oxidation model of gold-bearing arsenopyrite was set up. The selective bio-oxidation resulting from the submicro-battery effect of gold/ arsenopyrite mineral pairs naturally forms in the gold-bearing arsenopyrite crystal. Thiobacillus ferrooxidans has priority to oxidize the place of gold-rich and oxidizes selectedly along with the crystal border, crystal face and crack. The bacteria oxidation process of gold-bearing arsenopyrite is divided into three stages: the first stage is the surface oxidation, the second stage is restraining oxidation and the third stage is the filament oxidation, bacteria oxidize along with cracks of arsenopyrite.

  17. Effect of mycorrhizae, Thiobacillus and sulfur nutrition on the chemical composition of soybean [Glycine max (L.)] Merr. seed.

    Science.gov (United States)

    Mostafavian, S R; Pirdashti, H; Ramzanpour, M R; Andarkhor, A A; Shahsavari, A

    2008-03-15

    A field experiment carried out in a calcareous soil with a low available phosphorus to evaluate effectiveness of biofertilizers, mycorrhizae (Glomus intraradices) and Thiobacillus sp. inoculation individually or in combination on seed yield, oil, protein and some elements (P, Fe, Mn, Zn) concentration in two soybean [Glycine max (L.) Merr.] cultivars. The applied treatments were different fertilizers with 6 levels (including: NP (control, 12 kg N ha(-1) as urea, 46 kg P2O5 ha(-1) as triple super phosphate); NPK (NP + 75 kg K2O ha(-1) as potassium sulphate); NPKS [NPK+ S (100 kg S ha(-1))]; NPKST (NPKS + seed inoculation with Thiobacillus bacteria); NPKM (NPK + Seed inoculation with mycorrhizae fungi) and NPKSTM (NPKS + seed inoculation with Thiobacillus and mycorrhizae) and two cultivars (JK and 032). Before planting, soybean seeds were inoculated by Bradyrhizobium japonicum in all treatments. Results showed that combined inoculation of biofertilizers increased yield, however the highest yield was observed in treatment NPKST. Increasing oil content (percentage) was more pronounced in treatments NPKM, while most protein content (percentage) increasing was observed in NPKS and NPKM. Fe and Zn concentrations were unaffected significantly by fertilizer treatments, but NPKSTM showed significantly higher value of seed's Mn concentration compared to treatments NP and NPK. Although no significant difference was observed in terms ofP concentration of 032 line among fertilizer treatments, JK cultivar and NPKSTM caused a significant increasing in P concentration compared to NP, NPKS and NPKM. Present results suggested that applying biofertilizers i.e., mycorrhizae and Thiobacillus increased soybean yield compared to control (NP). Overall, this study demonstrated that soybean seed yield and its chemical composition could be affected by biofertilizer inoculation.

  18. The Inhibitory Mechanism of the ζ Subunit of the F1FO-ATPase Nanomotor of Paracoccus denitrificans and Related α-Proteobacteria*

    OpenAIRE

    García-Trejo, José J.; Zarco-Zavala, Mariel; Mendoza-Hoffmann, Francisco; Hernández-Luna, Eduardo; Ortega, Raquel; Mendoza-Hernández, Guillermo

    2015-01-01

    The ζ subunit is a novel inhibitor of the F1FO-ATPase of Paracoccus denitrificans and related α-proteobacteria. It is different from the bacterial (ϵ) and mitochondrial (IF1) inhibitors. The N terminus of ζ blocks rotation of the γ subunit of the F1-ATPase of P. denitrificans (Zarco-Zavala, M., Morales-Ríos, E., Mendoza-Hernández, G., Ramírez-Silva, L., Pérez-Hernández, G., and García-Trejo, J. J. (2014) FASEB J. 24, 599–608) by a hitherto unknown quaternary structure that was first modeled h...

  19. The nitric-oxide reductase from Paracoccus denitrificans uses a single specific proton pathway.

    Science.gov (United States)

    ter Beek, Josy; Krause, Nils; Reimann, Joachim; Lachmann, Peter; Ädelroth, Pia

    2013-10-18

    The NO reductase from Paracoccus denitrificans reduces NO to N2O (2NO + 2H(+) + 2e(-) → N2O + H2O) with electrons donated by periplasmic cytochrome c (cytochrome c-dependent NO reductase; cNOR). cNORs are members of the heme-copper oxidase superfamily of integral membrane proteins, comprising the O2-reducing, proton-pumping respiratory enzymes. In contrast, although NO reduction is as exergonic as O2 reduction, there are no protons pumped in cNOR, and in addition, protons needed for NO reduction are derived from the periplasmic solution (no contribution to the electrochemical gradient is made). cNOR thus only needs to transport protons from the periplasm into the active site without the requirement to control the timing of opening and closing (gating) of proton pathways as is needed in a proton pump. Based on the crystal structure of a closely related cNOR and molecular dynamics simulations, several proton transfer pathways were suggested, and in principle, these could all be functional. In this work, we show that residues in one of the suggested pathways (denoted pathway 1) are sensitive to site-directed mutation, whereas residues in the other proposed pathways (pathways 2 and 3) could be exchanged without severe effects on turnover activity with either NO or O2. We further show that electron transfer during single-turnover reduction of O2 is limited by proton transfer and can thus be used to study alterations in proton transfer rates. The exchange of residues along pathway 1 showed specific slowing of this proton-coupled electron transfer as well as changes in its pH dependence. Our results indicate that only pathway 1 is used to transfer protons in cNOR.

  20. Cloning, expression and characterization of D-aminoacylase from Achromobacter xylosoxidans subsp. denitrificans ATCC 15173.

    Science.gov (United States)

    Wang, Wei; Xi, Huange; Bi, Qirui; Hu, Ying; Zhang, Yang; Ni, Mengxiang

    2013-07-19

    D-Aminoacylase catalyzes the conversion of N-acyl-D-amino acids to d-amino acids and fatty acids. The aim of this study was to identify the D-aminoacylase gene from Achromobacter xylosoxidans subsp. denitrificans ATCC 15173 and investigate the biochemical characterization of the enzyme. A previously uncharacterized D-aminoacylase gene (ADdan) from this organism was cloned and sequenced. The open reading frame (ORF) of ADdan was 1467 bp in size encoding a 488-amino acid polypeptide. ADdan, with a high amino acid similarity to N-acyl-D-aspartate amidohydrolase from Alcaligenes A6, showed relatively low sequence similarities to other characterized D-aminoacylases. The recombinant ADdan protein was expressed in Escherichia coli BL21 (DE3) using pET-28a with a T7 promoter. The enzyme was purified in a single chromatographic step using nickel affinity gel column. The molecular mass of the expressed protein, calculated by SDS-PAGE, was about 52 kDa. The purified ADdan showed optimal activity at pH 8.0 and 50°C, and was stable at pH 6.0-8.0 and up to 45°C. Its activity was inhibited by Cu(2+), Fe(2+), Ca(2+), Mn(2+), Ni(2+), Zn(2+) and Hg(2+), whereas Mg(2+) had no significant influence on this recombinant D-aminoacylase. This is the first report on the characterization of D-aminoacylase with activity towards both N-acyl derivatives of neutral D-amino acids and N-acyl-D-aspartate. The characteristics of ADdan could prove to be of interest in industrial production of D-amino acids.

  1. Tightly bound nucleotides of the energy-transducing ATPase, and their role in oxidative phosphorylation. I. The Paracoccus denitrificans system.

    Science.gov (United States)

    Harris, D A; John, P; Radda, G K

    1977-03-11

    1. The coupling ATPase of Paracoccus denitrificans can be removed from the membrane by washing coupled membrane fragments at low salt concentrations. 2. This ATPase resembles coupling ATPases of mitochondria, chloroplasts and other bacteria. It is a negatively charged protein of molecular weight about 300,000. An inhibitor protein in bound tightly to the ATPase in vivo, and can be destroyed by trypsin treatment. 3. ATP and ADP are found tightly bound to the coupling ATPase of P. denitrificans, both in its membrane-bound and isolated state. The ATP/ADP ratio on the enzyme is greater than one. 4. Under de-energised condtions, the bound nucleotides are not available to the suspending medium. When the membrane is energised however, the bound nucleotides can exchange with added nucleotides and incorporate 32Pi. 32Ppi is incorporated into the beta and gamma positions of the bound nucleotides, but beta-labelling probably does not occur on the coupling ATPase. 5. Uncouplers inhibit the exchange of the free nucleotides or 32Pi into the bound nucleotides, while venturicidin (an energy transfer inhibitor) and aurovertin stimulate the exchange. 6. The response of the bound nucleotides to energisation is consistent with their being involved directly in the mechanism of oxidative phosphorylation.

  2. Assembly of respiratory complexes I, III, and IV into NADH oxidase supercomplex stabilizes complex I in Paracoccus denitrificans.

    Science.gov (United States)

    Stroh, Anke; Anderka, Oliver; Pfeiffer, Kathy; Yagi, Takao; Finel, Moshe; Ludwig, Bernd; Schägger, Hermann

    2004-02-01

    Stable supercomplexes of bacterial respiratory chain complexes III (ubiquinol:cytochrome c oxidoreductase) and IV (cytochrome c oxidase) have been isolated as early as 1985 (Berry, E. A., and Trumpower, B. L. (1985) J. Biol. Chem. 260, 2458-2467). However, these assemblies did not comprise complex I (NADH:ubiquinone oxidoreductase). Using the mild detergent digitonin for solubilization of Paracoccus denitrificans membranes we could isolate NADH oxidase, assembled from complexes I, III, and IV in a 1:4:4 stoichiometry. This is the first chromatographic isolation of a complete "respirasome." Inactivation of the gene for tightly bound cytochrome c552 did not prevent formation of this supercomplex, indicating that this electron carrier protein is not essential for structurally linking complexes III and IV. Complex I activity was also found in the membranes of mutant strains lacking complexes III or IV. However, no assembled complex I but only dissociated subunits were observed following the same protocols used for electrophoretic separation or chromatographic isolation of the supercomplex from the wild-type strain. This indicates that the P. denitrificans complex I is stabilized by assembly into the NADH oxidase supercomplex. In addition to substrate channeling, structural stabilization of a membrane protein complex thus appears as one of the major functions of respiratory chain supercomplexes.

  3. NCBI nr-aa BLAST: CBRC-LAFR-01-0953 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-LAFR-01-0953 ref|YP_316208.1| possible transmembrane protein [Thiobacillus den...itrificans ATCC 25259] gb|AAZ98403.1| possible transmembrane protein [Thiobacillus denitrificans ATCC 25259] YP_316208.1 0.005 24% ...

  4. Occurrence of Thiobacillus ferroxidans and Thiobacillus thio-oxidans in effluent, basin of reject and boot-rejections of uranium extraction mine: mill industrial complex of Pocos de Caldas, MG, Brazil; Ocorrencia de Thiobacillus ferrooxidans e Thiobacillus thiooxidans em efluentes, bacia de rejeito e bota-foras de mina de extracao de uranio - complexo minero-industrial de Pocos de Caldas, MG

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Helena de Azevedo [Comissao Nacional de Energia Nuclear, Pocos de Caldas, MG (Brazil). Laboratorio; Garcia Junior, Oswaldo [UNESP, Araraquara, SP (Brazil). Inst. de Quimica. Dept. de Bioquimica e Tecnologia Quimica

    2000-07-01

    The sulfated minerals present in mining areas may cause serious environmental problems, because of the chemolithotrophic bacteria action of the gender Thiobacillus, mainly the T. ferroxidans and T. thio-oxidans. These microorganisms are able to oxidize mineral sulfates, elementary sulfur and the ferrous ion (T. ferroxidans), being capable of mobilizing radionuclides as the uranium for the environment. In this context, this study had the aim of investigating the occurrence and the fluctuations in the T. ferroxidans and T. thio-oxidans populations, in mine, effluent, tailing dam and waste rock of the Mine and Mill Industrial Complex of Pocos de Caldas-MG (ICPC). The relative seasonal behavior of some variables, when evaluated simultaneously indicated that the high values of oxidation-reduction potential, the low values of pH, the detection of the largest percentages of incidence and highest values of T. ferroxidans and T. thio-oxidans counting, observed in the sites 075, BIA, CM, BF4, BF8 and BE, indicated that these are the principal places of mine acid drainage occurrence and bio-leaching bacteria action in the ICPC and be considered critical sites, faced to a possible decommission measure. (author)

  5. A microbial method using whole cells of Thiobacillus thiooxidans for measuring sulphate in waters

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, K.; Yudiarto, M.A.; Kaneko, N.; Kurosawa, H.; Amano, Y. [Dept. of Applied Chemistry and Biotechnology, Faculty of Engineering, Yamanashi Univ. (Japan)

    1997-12-31

    A microbial method to determine sulphate concentration in water was developed on the basis of sulphate-dependent acid phosphatase (APase) in whole cells of Thiobacillus thiooxidans. The activity of the APase was determined colorimetrically by using p-nitrophenylphosphate as substrate. The APase was activated by sulphate. A linear relationship was obtained between the activity of the APase and the concentration of sulphate in the range 0-0.06 mM. Therefore, the sulphate concentration was estimated from the APase activity, represented by the absorbance (A{sub 400}). The microbial method was applied to the determination sulphate in water. The lower limit of detection was 0.02 mM, the relative standard deviation being 2% for 10 measurements on a standard sample. As for practical samples, which were taken from rain, river and tap water, good agreement was obtained between the values measured by the microbial method and those given by a conventional barium chloranilate method. The relative standard deviation was 2.1% for 12 measurements of tap water. The activity of the APase was stable over a period of more than 100 days when the cells were stored in 0.1 M sodium acetate/acetic acid buffer (pH 5.0) at 4 C. (orig.)

  6. Purification and Some Properties of a Tetrathionate Decomposing Enzyme from Thiobacillus thiooxidans.

    Science.gov (United States)

    Tano, T; Kitaguchi, H; Harada, M; Nagasawa, T; Sugio, T

    1996-01-01

    A tetrathionate-decomposing enzyme that catalyzes the decomposition of tetrathionate into thiosulfate and sulfate was purified to homogeneity from tetrathionate-grown Thiobacillus thiooxidans. The enzyme had an apparent molecular weight of 104,000, and was composed of two identical subunits (MW = 58,000) as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme had an isoelectric point at 9.6 and was most active at pH 3.0-3.5 and 40°C. Enzyme activity was increased approximately 100-fold in the presence of 400 mm sulfate ion. The Michaelis constant of this enzyme for tetrathionate in the presence of 20, 50, and 200 mm of sulfate ion was 2.4 mm. Mercuric and ferric ions completely inhibited the enzyme activity at 1 mm. Though cupric ion up to 0.01 mm markedly stimulated the activity in the presence of 20 mm sulfate ion, a higher concentration (1 mm) rather strongly inhibited the activity. Ethylenediaminetetraacetic acid (EDTA) strongly inhibited the activity, but this inhibiton was completely restored by cupric ion.

  7. Removal of hydrogen sulfide by immobilized Thiobacillus thioparus in a biotrickling filter packed with polyurethane foam.

    Science.gov (United States)

    Ramírez, Martín; Gómez, José Manuel; Aroca, Germán; Cantero, Domingo

    2009-11-01

    In the work described here, a biotrickling filter with Thiobacillus thioparus (ATCC 23645) immobilized on polyurethane foam is proposed for the removal of hydrogen sulfide contained in air. The effect of surface velocity of the recirculation medium (5.9-1.2 m/h), sulfate concentration inhibition (3.0-10.7 g/L), pH (6.0-8.2), empty bed residence time (EBRT) (150-11 s) for constant loads of 11.5 and 2.9 g S/m(3)/h, and pressure drop of the system were investigated. The total amount of biomass immobilized on the carrier was 8.2+/-1.3x10(10) cells/g. The optimal values of the operating variables were: pH between 7.0 and 7.5, surface velocity of 5.9 m/h and sulfate concentration below 5 g/L. The critical EC value was 14.9 g S/m(3)/h (removal efficiency of 99.8%) and the EC(max) was 55.0 g S/m(3)/h (removal efficiency of 79.8%) for an EBRT of 150 s. For loads of 2.89+/-0.05 and 11.5+/-0.1 g S/m(3)/h, the removal efficiency was higher than 99% for an EBRT over 90 s.

  8. Effect of Thiobacillus, sulfur, and vermicompost on the water-soluble phosphorus of hard rock phosphate.

    Science.gov (United States)

    Aria, Marzieh Mohammady; Lakzian, Amir; Haghnia, Gholam Hosain; Berenji, Ali Reza; Besharati, Hosein; Fotovat, Amir

    2010-01-01

    Sulfur, organic matter, and inoculation with sulfur-oxidizing bacteria are considered as amendments to increase the availability of phosphorus from rock phosphate. The present study was conducted to evaluate the best combination of sulfur, vermicompost, and Thiobacillus thiooxidans inoculation with rock phosphate from Yazd province for direct application to agricultural lands in Iran. For such study, an experiment was carried out in a completely randomized design with factorial arrangement: Elemental sulfur originated from Sarakhs mine at three rates, 0% (S1), 10% (S2), 20% (S3), vermicompost at two rates, 0% (V1), 15% (V2), and inoculation without (B1) and with (B2) T. thiooxidans, in three replications. The results showed that water-soluble phosphorus (WSP) content was significantly higher in inoculated treatments compared to non-inoculated treatments. Sulfur had a significant effect on WSP. The highest solubility rate of rock phosphate was obtained in 20% of sulfur (S3) treatments and it was 2.4 times more than S1 treatments. Vermicompost also had a significant and positive effect on WSP of rock phosphate dissolution. The results also revealed that the highest concentration of WSP, sulfate and the lowest pH were obtained in treatments with 20% sulfur, 15% vermicompost inoculated with T. thiooxidans (B2S3V2).

  9. Structure of apo-azurin from Alcaligenes denitrificans at 1.8 A resolution.

    Science.gov (United States)

    Shepard, W E; Kingston, R L; Anderson, B F; Baker, E N

    1993-05-01

    The structure of apo-azurin from Alcaligenes denitrificans has been determined at high resolution by X-ray crystallography. Two separate structure analyses have been carried out, (i) on crystals obtained from solutions of apo-azurin and (ii) on crystals obtained by removal of copper from previously formed crystals of holo-azurin. Data to 1.8 A resolution were collected from the apo-azurin crystals, by Weissenberg photography (with image plates) using synchrotron radiation and by diffractometry, and the structure was refined by restrained least-squares methods to a final R value of 0.160 for all data in the range 10.0-1.8 A. The final model of 1954 protein atoms, 246 water molecules (66 half-weighted), four SO(4)(2-) ions, and two low-occupancy (0.13 and 0.15) Cu atoms has r.m.s. deviations of 0.012, 0.045 and 0.013 A from standard bond lengths, angle distances and planar groups. For copper-removed azurin, data to 2.2 A were collected by diffractometry and the structure refined by restrained least squares to a final R value of 0.158 for all data in the range 10.0-2.2 A. The final model of 1954 protein atoms, 264 water molecules, two SO(4)(2-) ions, two low occupancy (0.18 and 0.22) metal atoms and one unidentified atom (modelled as S) has r.m.s. deviations of 0.013, 0.047 and 0.012 A from standard bond lengths, angle distances and planar groups. The two structures are essentially identical to each other and show no significant differences from the oxidized and reduced holo-azurin structures. The ligand side chains move slightly closer together following the removal of copper, with the radius of the cavity between the three strongly binding ligands, His 46, His 117 and Cys 112, shrinking from 1.31 A in reduced azurin to 1.24 A in oxidized azurin and 1.16 A in apo-azurin. There is a suggestion of increased flexibility in one of the copper-binding loops but the structure supports the view that the copper site found in holo-azurin is a stable structure, defined by the

  10. Biological deodorization of hydrogen sulfide using porous lava as a carrier of Thiobacillus thiooxidans.

    Science.gov (United States)

    Cho, K S; Ryu, H W; Lee, N Y

    2000-01-01

    Biological deodorization of hydrogen sulfide (H2S) was studied using porous lava as a carrier of Thiobacillus thiooxidans in a laboratory-scale biofilter. Three different samples of porous lava, A, B, and C, which were obtained from Cheju Island in Korea, were used. The water-holding capacities of samples A, B and C were 0.38, 0.25, and 0.47 g-H2O/g-lava, respectively. The pHs and densities of the lava samples ranged from 8.25-9.24 and 920-1190 kg/m3, respectively. The buffering capacities, expressed as the amount of sulfate added to lower the pH to 4, were 60 g-SO4(2-)/kg-lava for sample A, 50 g-SO4(2-)/kg-lava for B, and 90 g-SO4(2-)/kg-lava for C. To investigate the removal characteristics of H2S by the lava biofilters, T. thiooxidans was immobilized on the lava samples. Biofilters A and C showed a removal capacity of 428 g-S.m(-3).h(-1) when H2S was supplied with 428 g-S.m(-3).h(-1) of inlet load at a space velocity (SV) of 300 h(-1). At the same inlet load and SV, the removal capacity of biofilter B was 396 g-S.m(-3).h(-1). The H2S critical loads of biofilters A, B and C at a SV of 400 h(-1) were 396, 157 and 342 g-S.m(-3).h(-1), respectively. It is suggested that natural, porous lava is a promising candidate as a carrier of microorganisms in biofiltration.

  11. Mechanism of oxidation of inorganic sulfur compounds by thiosulfate-grown Thiobacillus thiooxidans.

    Science.gov (United States)

    Masau, R J; Oh, J K; Suzuki, I

    2001-04-01

    Thiobacillus thiooxidans was grown at pH 5 on thiosulfate as an energy source, and the mechanism of oxidation of inorganic sulfur compounds was studied by the effect of inhibitors, stoichiometries of oxygen consumption and sulfur, sulfite, or tetrathionate accumulation, and cytochrome reduction by substrates. Both intact cells and cell-free extracts were used in the study. The results are consistent with the pathway with sulfur and sulfite as the key intermediates. Thiosulfate was oxidized after cleavage to sulfur and sulfite as intermediates at pH 5, the optimal growth pH on thiosulfate, but after initial condensation to tetrathionate at pH 2.3 where the organism failed to grow. N-Ethylmaleimide (NEM) inhibited sulfur oxidation directly and the oxidation of thiosulfate or tetrathionate indirectly. It did not inhibit the sulfite oxidation by cells, but inhibited any reduction of cell cytochromes by sulfur, thiosulfate, tetrathionate, and sulfite. NEM probably binds sulfhydryl groups, which are possibly essential in supplying electrons to initiate sulfur oxidation. 2-Heptyl-4-hydroxy-quinoline N-oxide (HQNO) inhibited the oxidation of sulfite directly and that of sulfur, thiosulfate, and tetrathionate indirectly. Uncouplers, carbonyl cyanide-m-chlorophenylhydrazone (CCCP) and 2,4-dinitrophenol (DNP), inhibited sulfite oxidation by cells, but not the oxidation by extracts, while HQNO inhibited both. It is proposed that HQNO inhibits the oxidation of sulfite at the cytochrome b site both in cells and extracts, but uncouplers inhibit the oxidation in cells only by collapsing the energized state of cells, delta muH+, required either for electron transfer from cytochrome c to b or for sulfite binding.

  12. Electrochemistry suggests proton access from the exit site to the binuclear center in Paracoccus denitrificans cytochrome c oxidase pathway variants.

    Science.gov (United States)

    Meyer, Thomas; Melin, Frédéric; Richter, Oliver-M H; Ludwig, Bernd; Kannt, Aimo; Müller, Hanne; Michel, Hartmut; Hellwig, Petra

    2015-02-27

    Two different pathways through which protons access cytochrome c oxidase operate during oxygen reduction from the mitochondrial matrix, or the bacterial cytoplasm. Here, we use electrocatalytic current measurements to follow oxygen reduction coupled to proton uptake in cytochrome c oxidase isolated from Paracoccus denitrificans. Wild type enzyme and site-specific variants with defects in both proton uptake pathways (K354M, D124N and K354M/D124N) were immobilized on gold nanoparticles, and oxygen reduction was probed electrochemically in the presence of varying concentrations of Zn(2+) ions, which are known to inhibit both the entry and the exit proton pathways in the enzyme. Our data suggest that under these conditions substrate protons gain access to the oxygen reduction site via the exit pathway.

  13. Protoplast fusion technology for improved production of coenzyme Q10 using Paracoccus denitrificans ATCC 19367 mutant strains

    Directory of Open Access Journals (Sweden)

    Pradipta Tokdar

    2014-01-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Induced mutants generated from Paracoccus denitrificans ATCC 19367 having antibiotic resistant markers, were used as parent strains to carry out protoplast fusion. The generated fusants were screened using standardized protocol for CoQ10 production. Among the generated fusants, one fusant namely PF-P1 showed 1.73 folds enhancements in specific CoQ10 content than wild type strain. Fusant PF-P1 was characterized by biochemical and molecular approaches where it showed differences than wild type strain. The fusant was further identified by 16S rRNA gene sequence analysis that showed eight nucleotide base pair mutation on conserved region and 99% homology with Paracoccus denitrificans strains. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

  14. CLONING, SEQUENCING AND EXPRESSION STUDIES OF THE GENES ENCODING AMICYANIN AND THE BETA-SUBUNIT OF METHYLAMINE DEHYDROGENASE FROM THIOBACILLUS-VERSUTUS

    NARCIS (Netherlands)

    UBBINK, M; VANKLEEF, MAG; KLEINJAN, DJ; HOITINK, CWG; HUITEMA, F; BEINTEMA, JJ; DUINE, JA; CANTERS, GW

    1991-01-01

    The genes encoding amicyanin and the beta-subunit of methylamine dehydrogenase (MADH) from Thiobacillus versutus have been cloned and sequenced. The organization of these genes makes it likely that they are coordinately expressed and it supports earlier findings that the blue copper protein amicyani

  15. Single Bacterium Detection Using Sers

    Science.gov (United States)

    Gonchukov, S. A.; Baikova, T. V.; Alushin, M. V.; Svistunova, T. S.; Minaeva, S. A.; Ionin, A. A.; Kudryashov, S. I.; Saraeva, I. N.; Zayarny, D. A.

    2016-02-01

    This work is devoted to the study of a single Staphylococcus aureus bacterium detection using surface-enhanced Raman spectroscopy (SERS) and resonant Raman spectroscopy (RS). It was shown that SERS allows increasing sensitivity of predominantly low frequency lines connected with the vibrations of Amide, Proteins and DNA. At the same time the lines of carotenoids inherent to this kind of bacterium are well-detected due to the resonance Raman scattering mechanism. The reproducibility and stability of Raman spectra strongly depend on the characteristics of nanostructured substrate, and molecular structure and size of the tested biological object.

  16. Growth Kinetics of Thiobacillus thiooxidans on the Surface of Elemental Sulfur.

    Science.gov (United States)

    Konishi, Y; Asai, S; Yoshida, N

    1995-10-01

    The growth kinetics of Thiobacillus thiooxidans on elemental sulfur in batch cultures at 30(deg)C and pH 1.5 was studied by measuring the time courses of the concentration of adsorbed cells on sulfur, the concentration of free cells suspended in liquid medium, and the amount of sulfur oxidized. As the elemental sulfur was oxidized to sulfate ions, the surface concentration of adsorbed cells per unit mass of sulfur approached a maximum value (maximum adsorption capacity of sulfur particles) whereas the concentration of free cells continued to increase with time. There was a close relationship between the concentrations of free and adsorbed cells during the microbial sulfur oxidation, and the two cell concentrations were well correlated by the Langmuir isotherm with adsorption equilibrium constant K(infA) and maximum adsorption capacity X(infAm) of 2.10 x 10(sup-9) ml per cell and 4.57 x 10(sup10) cells per g, respectively. The total concentration of free and adsorbed cells increased in parallel with the amount of sulfate formed. The total growth on elemental sulfur gave a characteristic growth curve in which a linear-growth phase followed the period of an initial exponential phase. The batch rate data collected under a wide variety of inoculum levels (about 10(sup5) to 10(sup8) cells per ml) were consistent with a kinetic model assuming that the growth rate of adsorbed bacteria is proportional to the product of the concentration, X(infA), of adsorbed cells and the fraction, (theta)(infV), of adsorption sites unoccupied by cells. The kinetic and stoichiometric parameters appearing in the model were estimated from the experimental data, and the specific growth rate, (mu)(infA), and growth yield, Y(infA), were 2.58 day(sup-1) and 2.05 x 10(sup11) cells per g, respectively. The proposed model and the parameter values allowed us to predict quantitatively the surface attachment of T. thiooxidans cells on elemental sulfur and the bacterial growth in both initial

  17. Structural and functional analysis of aa3-type and cbb3-type cytochrome c oxidases of Paracoccus denitrificans reveals significant differences in proton-pump design

    OpenAIRE

    de Gier, Jan-Willem L.; Schepper, Mike; Reijnders, Willem N.M.; Dyck, Stef J. van; Slotboom, Dirk Jan; Warne, Antony; Saraste, Matti; Krab, Klaas; Finel, Moshe; Stouthamer, Adriaan H.; Van Spanning, Rob J. M.; van der Oost, John

    1996-01-01

    In Paracoccus denitrificans the aa3-type cytochrome c oxidase and the bb3-type quinol oxidase have previously been characterized in detail, both biochemically and genetically. Here we report on the isolation of a genomic locus that harbours the gene cluster ccoNOQP, and demonstrate that it encodes an alternative cbb3-type cytochrome c oxidase. This oxidase has previously been shown to be specifically induced at low oxygen tensions, suggesting that its expression is controlled by an oxygen-sen...

  18. Cytochromes c550, c552, and c1 in the Electron Transport Network of Paracoccus denitrificans: Redundant or Subtly Different in Function?

    OpenAIRE

    Otten, M.F.; Oost, van der, J.; Reijnders, W. N. M.; Westerhoff, H.V.; Ludwig, B.; Spanning, van, R.J.M.

    2001-01-01

    Paracoccus denitrificans strains with mutations in the genes encoding the cytochrome c550, c552, or c1 and in combinations of these genes were constructed, and their growth characteristics were determined. Each mutant was able to grow heterotrophically with succinate as the carbon and free-energy source, although their specific growth rates and maximum cell numbers fell variably behind those of the wild type. Maximum cell numbers and rates of growth were also reduced when these strains were g...

  19. Structure of a catalytic dimer of the α- and β-subunits of the F-ATPase from Paracoccus denitrificans at 2.3 Å resolution

    Energy Technology Data Exchange (ETDEWEB)

    Morales-Ríos, Edgar; Montgomery, Martin G. [The Medical Research Council Mitochondrial Biology Unit, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY (United Kingdom); Leslie, Andrew G. W. [The Medical Research Council Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH (United Kingdom); García-Trejo, José J. [Universidad Nacional Autónoma de México, Mexico City (Mexico); Walker, John E., E-mail: walker@mrc-mbu.cam.ac.uk [The Medical Research Council Mitochondrial Biology Unit, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY (United Kingdom)

    2015-09-23

    The structure of the αβ heterodimer of the F-ATPase from the α-proteobacterium P. denitrificans has been determined at 2.3 Å resolution. It corresponds to the ‘open’ or ‘empty’ catalytic interface found in other F-ATPases. The structures of F-ATPases have predominantly been determined from mitochondrial enzymes, and those of the enzymes in eubacteria have been less studied. Paracoccus denitrificans is a member of the α-proteobacteria and is related to the extinct protomitochondrion that became engulfed by the ancestor of eukaryotic cells. The P. denitrificans F-ATPase is an example of a eubacterial F-ATPase that can carry out ATP synthesis only, whereas many others can catalyse both the synthesis and the hydrolysis of ATP. Inhibition of the ATP hydrolytic activity of the P. denitrificans F-ATPase involves the ζ inhibitor protein, an α-helical protein that binds to the catalytic F{sub 1} domain of the enzyme. This domain is a complex of three α-subunits and three β-subunits, and one copy of each of the γ-, δ- and ∊-subunits. Attempts to crystallize the F{sub 1}–ζ inhibitor complex yielded crystals of a subcomplex of the catalytic domain containing the α- and β-subunits only. Its structure was determined to 2.3 Å resolution and consists of a heterodimer of one α-subunit and one β-subunit. It has no bound nucleotides, and it corresponds to the ‘open’ or ‘empty’ catalytic interface found in other F-ATPases. The main significance of this structure is that it aids in the determination of the structure of the intact membrane-bound F-ATPase, which has been crystallized.

  20. 两种硫杆菌对河涌底泥重金属的生物沥滤%Bioleaching of heavy metals from brooklet sediment by Thiobacillus ferrooxidans and Thiobacillus thiooxidans

    Institute of Scientific and Technical Information of China (English)

    张再利; 贾晓珊

    2008-01-01

    自矿山酸性废水中分离纯化得到氧化亚铁硫杆菌(Thiobacillus ferrooxidans,T.f)与氧化硫硫杆菌(Thiobacillus thiooxidans,T.t),利用这2种硫杆菌对广州郭村河涌底泥中Cd、Cr、Pb、Ni、Cu和Zn 6种重金属进行序批式生物沥滤试验.结果表明,T.f菌对重金属的浸出能力高于T.t菌.对Cd、Cr、Ni、Cu和Zn的浸出率Y.f菌最高可达60%、45%、70%、90%和75%,T.t菌则分别为45%、34%、50%、65%和55%.二者对Pb的去除率相当,均在25%左右.向T.f菌分别提供S粉与Fe2+,2种底物对Cd、Ni、Cu和Zn的浸出效果无明显影响,而对Cr和Pb的浸出,投加S粉的浸出效果更好.同时向T.f菌投加S粉与Fe2+2种底物,其浸出效果反而下降.可能是T.f菌代谢生成的SO42与Fe3+易生成黄铁矾等沉淀物质,与溶出的重金属发生共沉淀,从而降低其浸出效果.

  1. Effects of {sup 60}Co gamma-rays, ultraviolet light, and mitomycin C on halobacterium salinarium and thiobacillus intermedius

    Energy Technology Data Exchange (ETDEWEB)

    Shahmohammadi, H.R.; Asgarani, E.; Terato, Hiroaki; Ide, Hiroshi; Yamamoto, Osamu [Hiroshima Univ. (Japan)

    1997-03-01

    Lethal effects of {sup 60}Co {gamma}-rays, UV light, and mitomycin C on two kinds of bacteria, Halobacterium salinarium which grows in highly concentrated salt media and Thiobacillus intermedius which requires reduced sulfur compounds, were studied and compared with those on Escherichia coli B/r. D{sub 37} values for H. salinarium, T. intermedius and E. coli B/r were 393, 150, and 92 Gy, respectively, by exposure to {sup 60}Co {gamma}-rays. They were 212, 38, and 10 J/m{sup 2}, respectively, by exposure to UV light and 2.36, 0.25, and 0.53 {mu}g/ml/h, respectively, by exposure to mitomycin C. Against these agents, H salinarium was much more resistant than T. intermedius and E. coli B/r. (author)

  2. Effects of 60Co gamma-rays, ultraviolet light, and mitomycin C on Halobacterium salinarium and Thiobacillus intermedius.

    Science.gov (United States)

    Shahmohammadi, H R; Asgarani, E; Terato, H; Ide, H; Yamamoto, O

    1997-03-01

    Lethal effects of 60Co gamma-rays, UV light, and mitomycin C on two kinds of bacteria, Halobacterium salinarium which grows in highly concentrated salt media and Thiobacillus intermedius which requires reduced sulfur compounds, were studied and compared with those on Escherichia coli B/r. D37 values for H. salinarium, T. intermedius and E. coli B/r were 393, 150, and 92 Gy, respectively, by exposure to 60Co gamma-rays. They were 212, 38, and 10 J/m2, respectively, by exposure to UV light and 2.36, 0.25, and 0.53 microgram/ml/h, respectively, by exposure to mitomycin C. Against these agents, H. salinarium was much more resistant than T. intermedius and E. coli B/r.

  3. AztD, a Periplasmic Zinc Metallochaperone to an ATP-binding Cassette (ABC) Transporter System in Paracoccus denitrificans.

    Science.gov (United States)

    Handali, Melody; Roychowdhury, Hridindu; Neupane, Durga P; Yukl, Erik T

    2015-12-11

    Bacterial ATP-binding cassette (ABC) transporters of transition metals are essential for acquisition of necessary elements from the environment. A large number of Gram-negative bacteria, including human pathogens, have a fourth conserved gene of unknown function adjacent to the canonical permease, ATPase, and solute-binding protein (SBP) genes of the AztABC zinc transporter system. To assess the function of this putative accessory factor (AztD) from Paracoccus denitrificans, we have analyzed its transcriptional regulation, metal binding properties, and interaction with the SBP (AztC). Transcription of the aztD gene is significantly up-regulated under conditions of zinc starvation. Recombinantly expressed AztD purifies with slightly substoichiometric zinc from the periplasm of Escherichia coli and is capable of binding up to three zinc ions with high affinity. Size exclusion chromatography and a simple intrinsic fluorescence assay were used to determine that AztD as isolated is able to transfer bound zinc nearly quantitatively to apo-AztC. Transfer occurs through a direct, associative mechanism that prevents loss of metal to the solvent. These results indicate that AztD is a zinc chaperone to AztC and likely functions to maintain zinc homeostasis through interaction with the AztABC system. This work extends our understanding of periplasmic zinc trafficking and the function of chaperones in this process.

  4. Development and application of small-subunit rRNA probes for assessment of selected Thiobacillus species and members of the genus Acidiphilium.

    Science.gov (United States)

    Peccia, J; Marchand, E A; Silverstein, J; Hernandez, M

    2000-07-01

    Culture-dependent studies have implicated sulfur-oxidizing bacteria as the causative agents of acid mine drainage and concrete corrosion in sewers. Thiobacillus species are considered the major representatives of the acid-producing bacteria in these environments. Small-subunit rRNA genes from all of the Thiobacillus and Acidiphilium species catalogued by the Ribosomal Database Project were identified and used to design oligonucleotide DNA probes. Two oligonucleotide probes were synthesized to complement variable regions of 16S rRNA in the following acidophilic bacteria: Thiobacillus ferrooxidans and T. thiooxidans (probe Thio820) and members of the genus Acidiphilium (probe Acdp821). Using (32)P radiolabels, probe specificity was characterized by hybridization dissociation temperature (T(d)) with membrane-immobilized RNA extracted from a suite of 21 strains representing three groups of bacteria. Fluorochrome-conjugated probes were evaluated for use with fluorescent in situ hybridization (FISH) at the experimentally determined T(d)s. FISH was used to identify and enumerate bacteria in laboratory reactors and environmental samples. Probing of laboratory reactors inoculated with a mixed culture of acidophilic bacteria validated the ability of the oligonucleotide probes to track specific cell numbers with time. Additionally, probing of sediments from an active acid mine drainage site in Colorado demonstrated the ability to identify numbers of active bacteria in natural environments that contain high concentrations of metals, associated precipitates, and other mineral debris.

  5. ω-Amino Acid:Pyruvate Transaminase from Alcaligenes denitrificans Y2k-2: a New Catalyst for Kinetic Resolution of β-Amino Acids and Amines

    OpenAIRE

    Yun, Hyungdon; Lim, Seongyop; Cho, Byung-Kwan; Kim, Byung-Gee

    2004-01-01

    Alcaligenes denitrificans Y2k-2 was obtained by selective enrichment followed by screening from soil samples, which showed ω-amino acid:pyruvate transaminase activity, to kinetically resolve aliphatic β-amino acid, and the corresponding structural gene (aptA) was cloned. The gene was functionally expressed in Escherichia coli BL21 by using an isopropyl-β-d-thiogalactopyranoside (IPTG)-inducible pET expression system (9.6 U/mg), and the recombinant AptA was purified to show a specific activity...

  6. The structural and functional basis of catalysis mediated by NAD(PH:acceptor Oxidoreductase (FerB of Paracoccus denitrificans.

    Directory of Open Access Journals (Sweden)

    Vojtěch Sedláček

    Full Text Available FerB from Paracoccus denitrificans is a soluble cytoplasmic flavoprotein that accepts redox equivalents from NADH or NADPH and transfers them to various acceptors such as quinones, ferric complexes and chromate. The crystal structure and small-angle X-ray scattering measurements in solution reported here reveal a head-to-tail dimer with two flavin mononucleotide groups bound at the opposite sides of the subunit interface. The dimers tend to self-associate to a tetrameric form at higher protein concentrations. Amino acid residues important for the binding of FMN and NADH and for the catalytic activity are identified and verified by site-directed mutagenesis. In particular, we show that Glu77 anchors a conserved water molecule in close proximity to the O2 of FMN, with the probable role of facilitating flavin reduction. Hydride transfer is shown to occur from the 4-pro-S position of NADH to the solvent-accessible si side of the flavin ring. When using deuterated NADH, this process exhibits a kinetic isotope effect of about 6 just as does the NADH-dependent quinone reductase activity of FerB; the first, reductive half-reaction of flavin cofactor is thus rate-limiting. Replacing the bulky Arg95 in the vicinity of the active site with alanine substantially enhances the activity towards external flavins that obeys the standard bi-bi ping-pong reaction mechanism. The new evidence for a cryptic flavin reductase activity of FerB justifies the previous inclusion of this enzyme in the protein family of NADPH-dependent FMN reductases.

  7. Structure/function relationship of the rusticyanin among thiobacillus ferroxidans: from the fermenter to the crystal; Relations structure/fonction de la rusticyanine chez thiobacillus ferrooxidans: du fermenteur au cristal

    Energy Technology Data Exchange (ETDEWEB)

    Nunzi, F.

    1996-09-23

    The commercial extraction of copper and uranium from ores by microbial leaching turns to account the iron oxidation capacity of Thiobacillus ferroxidans. The iron oxidation involves an electron transport chain localized in the peri-plasmic space of the cell. The aim of our work is to study the structure-function relationships of rusticyanin, the most important component of this respiratory chain. Rusticyanin is a blue copper protein and has been characterized from a new strain of Thilbacillus ferrooxidans. A preliminary electrochemical study has been made with a new modified-gold electrode and we have examined, in particular, the pH dependence of the high redox potential of rusticyanin. Its amino acid sequence has been determined and a comparison with two other rusticyanin sequences, isolated from different strains, shows a high degree of homology. A structural alignment with six other blue copper proteins allows to propose four residues as copper ligands, His 84, Cys 138, His 143 and Met 148. The supposed factors responsible for the high redox potential of rusticyanin are discussed. (author)

  8. Thiocyanate hydrolase, the primary enzyme initiating thiocyanate degradation in the novel obligately chemolithoautotrophic halophilic sulfur-oxidizing bacterium Thiohalophilus thiocyanoxidans.

    Science.gov (United States)

    Bezsudnova, Ekaterina Yu; Sorokin, Dimitry Yu; Tikhonova, Tamara V; Popov, Vladimir O

    2007-12-01

    Thiohalophilus thiocyanoxidans is a first halophilic sulfur-oxidizing chemolithoautotrophic bacterium capable of growth with thiocyanate as an electron donor at salinity up to 4 M NaCl. The cells, grown with thiocyanate, but not with thiosulfate, contained an enzyme complex hydrolyzing thiocyanate to sulfide and ammonia under anaerobic conditions with carbonyl sulfide as an intermediate. Despite the fact of utilization of the , high cyanase activity was also detected in thiocyanate-induced cells. Three-stage column chromotography resulted in a highly purified thiocyanate-hydrolyzing protein with an apparent molecular mass of 140 kDa that consists of three subunits with masses 17, 19 and 29 kDa. The enzyme is a Co,Fe-containing protein resembling on its function and subunit composition the enzyme thiocyanate hydrolase from the Betaproteobacterium Thiobacillus thioparus. Cyanase, copurified with thiocyanate hydrolase, is a bisubstrate multisubunit enzyme with an apparent subunit molecular mass of 14 kDa. A possible role of cyanase in thiocyanate degradation by T. thiocyanoxidans is discussed.

  9. Heterotrophic nature of the cell-free protein-synthesizing system from the strict chemolithotroph, Thiobacillus thiooxidans.

    Science.gov (United States)

    Amemiya, K; Umbreit, W W

    1974-02-01

    A cell-free protein-synthesizing system prepared from the strict chemolithotroph, Thiobacillus thiooxidans, was similar to that of heterotrophs. The poly-U directed system had a temperature optimum of 37 C, but in the presence of spermidine (3 mM) the optimum shifted to 45 C. Although growth of the chemolithotroph occurs only in acid conditions, the pH optimum for the cell-free system was pH 7.2. The endogenous-directed activity in the presence or absence of spermidine was maximal at pH 7.8. Spermidine had a stimulatory effect; however, this effect was dependent on the magnesium and tris(hydroxymethyl)aminomethane (Tris) concentrations. At low Tris concentrations (10 mM), spermidine (3 to 5 mM) could completely replace magnesium. When the Tris concentration was increased (50 mM), spermidine could not replace magnesium. Supernatant and ribosomal fractions from T. thiooxidans were exchanged with those of Bacillus thuringiensis and Escherichia coli, and the ribosomal fraction from the chemolithotroph gave good to moderate stimulation when exchanged with the supernatant from the heterotrophs. On the other hand, the supernatant from T. thiooxidans gave good stimulation when mixed with ribosomes from B. thuringiensis but poor activity with ribosomes from E. coli. Both supernatant and ribosomal fractions prepared from stationary phase extracts of T. thiooxidans were inactive in the cell-free system.

  10. Hydrogen sulfide oxidation in novel Horizontal-Flow Biofilm Reactors dominated by an Acidithiobacillus and a Thiobacillus species.

    Science.gov (United States)

    Gerrity, S; Kennelly, C; Clifford, E; Collins, G

    2016-09-01

    Hydrogen Sulfide (H2S) is an odourous, highly toxic gas commonly encountered in various commercial and municipal sectors. Three novel, laboratory-scale, Horizontal-Flow Biofilm Reactors (HFBRs) were tested for the removal of H2S gas from air streams over a 178-day trial at 10°C. Removal rates of up to 15.1 g [H2S] m(-3) h(-1) were achieved, demonstrating the HFBRs as a feasible technology for the treatment of H2S-contaminated airstreams at low temperatures. Bio-oxidation of H2S in the reactors led to the production of H(+) and sulfate (SO(2-)4) ions, resulting in the acidification of the liquid phase. Reduced removal efficiency was observed at loading rates of 15.1 g [H2S] m(-3) h(-1). NaHCO3 addition to the liquid nutrient feed (synthetic wastewater (SWW)) resulted in improved H2S removal. Bacterial diversity, which was investigated by sequencing and fingerprinting 16S rRNA genes, was low, likely due to the harsh conditions prevailing in the systems. The HFBRs were dominated by two species from the genus Acidithiobacillus and Thiobacillus. Nonetheless, there were significant differences in microbial community structure between distinct HFBR zones due to the influence of alkalinity, pH and SO4 concentrations. Despite the low temperature, this study indicates HFBRs have an excellent potential to biologically treat H2S-contaminated airstreams.

  11. 氧化亚铁硫杆菌对金属铜的加工%BIOMACHINING OF METAL COPPEY BY THIOBACILLUS FERROOXIDANS

    Institute of Scientific and Technical Information of China (English)

    李雅芹; 张德远; 吴依陶

    2000-01-01

    Thiobacillus ferrooxidans was employed in the biomachining process of metal copper(Cuo). The bacteria growth and the changes of Fe3+ concentration during machining processes have been studied. Biomachining and chemical machining have been compared.The results showed that the concentrations of bacteria and Fe3+ determine the speed of machining copper. The biomachining is more fast that chemical maching because bacteria are able to regenerate Fe3+ oxidizing copper. It was also found that the Cu2 + produced from the machining processes inhibit the growth of bacteria. Cu2+ has to be removed.

  12. Effect of pH on sulfite oxidation by Thiobacillus thiooxidans cells with sulfurous acid or sulfur dioxide as a possible substrate.

    Science.gov (United States)

    Takeuchi, T L; Suzuki, I

    1994-02-01

    The oxidation of sulfite by Thiobacillus thiooxidans was studied at various pH values with changing concentrations of potassium sulfite. The optimal pH for sulfite oxidation by cells was a function of sulfite concentrations, rising with increasing substrate concentrations, while that by the cell extracts was unaffected. The sulfite oxidation by cells was inhibited at high sulfite concentrations, particularly at low pH values. The results from kinetic studies show that the fully protonated form of sulfite, sulfurous acid or sulfur dioxide, is the form which penetrates the cells for the oxidation.

  13. EXAFS analysis of the pH dependence of the blue-copper site in amicyanin from Thiobacillus versutus.

    Science.gov (United States)

    Lommen, A; Pandya, K I; Koningsberger, D C; Canters, G W

    1991-02-15

    The room temperature Cu K-edge EXAFS (extended X-ray absorption fine structure) spectrum of reduced and oxidized amicyanin, the blue copper protein from Thiobacillus versutus, was measured at low and high pH. The data interpretation was partly based on independent NMR evidence for the occurrence of a ligand histidine protonation at low pH (pKa = 6.9) in the reduced protein. In the oxidized protein two nitrogen-donors (from two histidines; Cu-N distances 1.95-2.01 A and 1.86-1.89 A) and a sulfur-donor (from a cysteine; Cu-S distance 2.11-2.13 A) were identified and the coordination appears independent of pH. Upon reduction at high pH the Cu-S bond and one of the Cu-N bonds lengthen slightly (from 2.11 to 2.19 A and from 2.01 to 2.18 A, respectively). Upon lowering of the pH one of the N-donors of the Cu in reduced amicyanin disappears from the Cu EXAFS and a second S-donor (from a methionine) becomes visible at 2.41 A from the Cu. The Debye-Waller factors are compatible with a Cu-N vibrational stretch frequency in the range of 150-250 cm-1 and one greater than 285 cm-1, and a Cu-S vibrational stretch frequency of about 150 cm-1 (Cu-Smet; reduced amicyanin at low pH) and one in the range of 230-800 cm-1 (Cu-Scys).

  14. The Effects of Amino Acid Nutrition of Lag Phase in Growth of Thiobacillus ferrooxidans%氨基酸营养对At.f菌生长迟缓期的影响

    Institute of Scientific and Technical Information of China (English)

    张一

    2011-01-01

    [Objective] The effects of amino acid nutrition of lag phase in growth of thiobacillus ferrooxidans were researched. [Methods] The thiobacillus ferrooxidans were cultured in 20 different amino acids culture mediums. Use potassium dichromate titration to determination the u-tilization of Fe2+ all time, and the pH change of culture medium after added amino acids were studied. [ Results ] Non-polar amino acids have better effect to reduce the Lag phase of thiobacillus ferrooxidans, phenylalanine, tyrosine, proline and tryptophan also have similar effects. Ser-ine, glutamine and histidine are inhibited to reduced lag phase of thiobacillus ferrooxidans. [ Conclusion ] Non-polar amino acids can shorten the lag phase of thiobacillus ferrooxidans effectively, and several polar amino acids have the opposite effects.%[目的]研究氨基酸营养对At.f菌生长迟缓期的影响.[方法]将At.f在分别加入20种氨基酸的培养基中培养,利用重铬酸钾滴定法测定各时段Fe2+利用情况,并检测添加氨基酸后培养基pH的变化.[结果]非极性氨基酸对缩短At.f菌的迟缓期的效果较明显;苯丙氨酸、酪氨酸、脯氨酸、色氨酸四种成环氨基酸有较好的效果;丝氨酸、谷氨酰胺、组氨酸有明显的抑制作用.[结论]非极性氨基酸能有效缩短At.f菌生长迟缓期,部分极性氨基酸则起到相反效果.

  15. IDENTIFICATION OF THE BACTERIUM TOMATO STEM CANKER

    Directory of Open Access Journals (Sweden)

    Goner A. Shaker

    2014-01-01

    Full Text Available Diseased tomato samples were collected from green house was evaluated for isolation, pathogenicity and biochemical tests. The symptoms of the infected tomato plants were as sudden wilting after curled on leaves and necrotic streak regions developed at the crown and base of the stem and the cavities deepen and expand up and down, brown discoloration and necrosis occurring on xylem and phloem vasculer. All of ages of tomato plant were susceptible to bacteria when the weather condition favorable and immediately, seen collapse symptom on tomato plant at once fail and die. The bacterium was isolated from diseased plant in all regions on nutrient Agar; a yellow bacterium was isolated from infected tomato plant in green houses and fields in Abu-Ghraib, Rashiedia and Qanat Al-Geiaysh nurseries in Baghdad provinces of Iraq. The bacterium was found gram positive, rod-shaped, non-motile and capable an aerobic growth and based on the morphological and biochemical characteristics revealed that this bacterium belongs to: Clavibacter michiganensis subsp. michiganensis. (smith pathogenicity and hypersensitivity of the bacterium Cmm showed the disease index were 18.33, 6.66, 16.66, 5, 0% for tomato seedlings were inoculated treatments as the wounding roots, without wounding roots, crown of the stem, petiole and control respectively.

  16. 复合硫杆菌生物淋滤对Mn去除的研究%Study on Mn Removal by Composite Thiobacillus Bioleaching

    Institute of Scientific and Technical Information of China (English)

    霍金枝; 张弛; 王增长

    2012-01-01

    By use of composite Thiobacillus (Thiobacillus ferrooxidans and Thiobacillus thiooxidans) at different inoculum quantity (5%,10%,20%) for municipal sludge bioleaching experiments, it investigated the changes of pH and redox potential (ORP) 、 leaching effects on Mn and Mn form variation during the process.The results showed that: the method could leach Mn out of the sludge effectively .After 12 days, the leaching out rate of Mn in reactor reached 100% under 10% inoculation rate. Leaching out rate of Mn was affected by pH and ORP, and the relationship was that the leaching out rate was 2.439-0.452pH-0.002ORP, changes of the exchangeable form and the residual form of Mn were great, the morphological changes indicated that Mn was leaching out effectively; the leaching abilities of various forms of Mn were as follow: carbonate bound> Fe-Mn oxides bound > residual fraction> organic bound.%通过利用复合硫杆菌(氧化亚铁硫杆菌和氧化硫硫杆菌)在不同接种量(5%,10%,20%)对市政污泥进行生物淋滤实验,探讨了淋滤过程中pH和氧化还原电位( ORP)、Mn的淋滤效果及淋滤过程中其形态的变化.结果表明:该方法能有效淋出污泥中的Mn,生物淋滤12d后,10%接种量反应器Mn的淋出率达到100%; Mn的淋出率受pH和ORP的双重影响,与pH和ORP的关系为:淋出率等于2.439-0.452pH-0.0020RP;各形态中Mn的可交换态和残渣态变化幅度大,从形态变化上表明该淋滤反应对Mn具有有效的淋出;Mn各形态的淋滤能力是:碳酸盐结合态>铁锰氧化物结合态>残渣态>有机物结合态.

  17. Study on Bioleaching Technique of Collophanite by Thiobacillus Thiooxidans%嗜酸硫杆菌浸出胶磷矿的工艺研究

    Institute of Scientific and Technical Information of China (English)

    吴敏; 李凌凌; 关海燕

    2010-01-01

    从湖北某酸性矿土中富集、分离和纯化获得了一株氧化硫硫杆菌(Thiobacillus thiooxidans, T t ),并对驯化4次的该菌浸出胶磷矿中磷的工艺条件进行了初步探索.结果显示,在接种量为30%,初始pH为2.0,磷矿浓度为10 g/L,颗粒度-0.074 mm粒级占68%,黄铁矿加入量为10 g/L,浸矿10 d后浸磷率可达到90.71%.

  18. Zymomonas mobilis: a bacterium for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Baratti, J.C.; Bu' Lock, J.D.

    1986-01-01

    Zymomonas mobilis is a facultative anaerobic gram negative bacterium first isolated in tropical countries from alcoholic beverages like the African palm wine, the Mexican pulque and also as a contaminant of cider (cider sickness) or beer in the European countries. It is one of the few facultative anaerobic bacteria degrading glucose by the Entner-Doudoroff pathway usually found in strictly aerobic microorganisms. Some work was devoted to this bacterium in the 50s and 60s and was reviewed by Swings and De Ley in their classical paper published in 1977. During the 70s there was very little work on the bacterium until 1979 and the first report by the Australian group of P.L. Rogers on the great potentialities of Z. mobilis for ethanol production. At that time the petroleum crisis had led the developed countries to search for alternative fuel from renewable resources. The Australian group clearly demonstrated the advantages of the bacterium compared to the yeasts traditionally used for the alcoholic fermentation. As a result, there was a considerable burst in the Zymomonas literature which started from nearly zero in the late 70s to attain 70 papers published in the field in 1984. In this article, papers published from 1982 to 1986 are reviewed.

  19. Novel Waddlia Intracellular Bacterium in Artibeus intermedius Fruit Bats, Mexico.

    Science.gov (United States)

    Pierlé, Sebastián Aguilar; Morales, Cirani Obregón; Martínez, Leonardo Perea; Ceballos, Nidia Aréchiga; Rivero, Juan José Pérez; Díaz, Osvaldo López; Brayton, Kelly A; Setién, Alvaro Aguilar

    2015-12-01

    An intracellular bacterium was isolated from fruit bats (Artibeus intermedius) in Cocoyoc, Mexico. The bacterium caused severe lesions in the lungs and spleens of bats and intracytoplasmic vacuoles in cell cultures. Sequence analyses showed it is related to Waddlia spp. (order Chlamydiales). We propose to call this bacterium Waddlia cocoyoc.

  20. GC-MS分析氧化硫硫杆菌培养液的挥发性成份%Volatility Ingredients in the inoculum of Thiobacillus thiooxidans Analyzed by GC-MS

    Institute of Scientific and Technical Information of China (English)

    乐长高; 谢宗波; 姜国芳; 廖夫生

    2004-01-01

      In this paper, Gas chromatography/mass spectrometry was used to study the metabolites of strong radiation resistant thiobacillus thiooxidans (T.t), 32 compounds were isolated from the inoculum of T.t, and 26 compounds were elucidated based upon the results of GC-MS and standard figures.%  采用GC-MS联用技术对耐强辐射微生物氧化硫硫杆菌(Thiobacillus thiooxidans,简称T.t菌)的代谢产物进行了初步研究,从氧化硫硫杆菌的培养液中发现了32种代谢物,通过GC-MS和标准谱图鉴定了其中的26种化合物.

  1. The structure of RdDddP from Roseobacter denitrificans reveals that DMSP lyases in the DddP-family are metalloenzymes.

    Directory of Open Access Journals (Sweden)

    Jan-Hendrik Hehemann

    Full Text Available Marine microbes degrade dimethylsulfoniopropionate (DMSP, which is produced in large quantities by marine algae and plants, with DMSP lyases into acrylate and the gas dimethyl sulfide (DMS. Approximately 10% of the DMS vents from the sea into the atmosphere and this emission returns sulfur, which arrives in the sea through rivers and runoff, back to terrestrial systems via clouds and rain. Despite their key role in this sulfur cycle DMSP lyases are poorly understood at the molecular level. Here we report the first X-ray crystal structure of the putative DMSP lyase RdDddP from Roseobacter denitrificans, which belongs to the abundant DddP family. This structure, determined to 2.15 Å resolution, shows that RdDddP is a homodimeric metalloprotein with a binuclear center of two metal ions located 2.7 Å apart in the active site of the enzyme. Consistent with the crystallographic data, inductively coupled plasma mass spectrometry (ICP-MS and total reflection X-ray fluorescence (TRXF revealed the bound metal species to be primarily iron. A 3D structure guided analysis of environmental DddP lyase sequences elucidated the critical residues for metal binding are invariant, suggesting all proteins in the DddP family are metalloenzymes.

  2. The Online Morphology Control and Dynamic Studies on Improving Vitamin B12 Production by Pseudomonas denitrificans with Online Capacitance and Specific Oxygen Consumption Rate.

    Science.gov (United States)

    Wang, Ze-Jian; Shi, Hui-Lin; Wang, Ping

    2016-07-01

    The relationship between the morphological character of Pseudomonas denitrificans and vitamin B12 synthesis based on real-time capacitance measurement and online specific oxygen consumption rate (Q O2) control was established for enhancing vitamin B12 production. Results demonstrated that the threshold Q O2 value lower than 2.0 mmol/gDCW/l would greatly stimulate the state transfer from the cell number growth phase to the cell elongation phase and promote rapid vitamin B12 biosynthesis, while the vitamin B12 biosynthesis rate could also be inhibited when the rate of cell's length-to-width ratio (ratio-LW) was higher than 10:1. Furthermore, the optimal morphology controlling strategy was achieved based on online Q O2 control, which increases the appropriate active cell numbers at the former phase, and then control the elongation of ratio-LW no more than 10:1 at the vitamin B12 biosynthesis phase. The maximal vitamin B12 production reached 239.7 mg/l at 168 h, which was improved by 14.7 % compared with the control (208 mg/l). This online controlling strategy would be effectively applied for improving industrial vitamin B12 fermentation.

  3. Structural Stability, Transitions, and Interactions within SoxYZCD-Thiosulphate from Sulfurimonas denitrificans: An In Silico Molecular Outlook for Maintaining Environmental Sulphur Cycle

    Science.gov (United States)

    Banerjee, Arundhati

    2016-01-01

    Thiosulphate oxidation (an essential mechanism) serves to maintain the global sulphur cycle. Earlier experimental and computational studies dealt with environmental thiosulphate oxidation but none dealt with thiosulphate oxidation from deep ocean belts. Wet-laboratory experimental research shows that epsilon-proteobacteria Sulfurimonas denitrificans possess sox (sulphur-oxidizing) operon and perform thiosulphate oxidation efficiently underneath the oceans. From this specific sox operon, SoxCD complex recycles the thiosulphate-bound SoxY from SoxYZ complex to balance the environmental sulphur cycle. So, four chief proteins were variedly modeled and relevant simulated interactive structures were obtained. The final simulated tetraprotein complex (SoxYZCD) from docked SoxYZ and SoxCD complexes was disclosed to be a highly interactive one with predominant ionic residues. Free energy of folding, solvent accessibility, and conformational shifts (coil-like conformation to helices and sheets) were observed in SoxYZ complex after interacting with SoxCD. The stability of the complex (SoxYZCD) after simulation was also observed through the electrostatic surface potential values. These evaluations were rationalized via biostatistics. This aids SoxCD for recycling SoxY along with thiosulphate, which remains interconnected by four H-bonds with SoxY. Therefore, this novel exploration is endowed with the detailed molecular viewpoint for maintaining the sulphur cycle (globally) including the ocean belts. PMID:27777586

  4. Experimental Study of the Rhizobium and Iron Oxide Thiobacillus for Heap Leaching of Zinc Leaching Slag%根瘤菌与氧化铁硫杆菌堆浸锌浸出渣的试验研究

    Institute of Scientific and Technical Information of China (English)

    李勇; 邓兴; 金开胜; 杨光棣

    2012-01-01

    This paper adopts the rhizobium and thiobaeillus ferrooxidans respectively for heap leaching processing of hydrometallurgy of zinc leaching residue. Through the treatment of rhizobium with thiobacillus ferrooxidans, zinc leaching residue of zinc leaching rate is compared. The test results indicate that rhizobium treatment of zinc leaching residue of zinc leaching rate reaches 24.12 % and thiobacillus ferrooxidans treatment of zinc leaching residue of zinc leaching rate reaches 33.86 %. Treatment rate by thiobacillus ferrooxidans was significantly higher than that of rhizobium.%本文采用根瘤菌与氧化铁硫杆菌分别堆浸处理湿法冶金的锌浸出渣,通过比较根瘤菌与氧化铁硫杆菌处理的锌浸出渣的锌浸出率。试验结果表明,根瘤菌处理锌浸出渣锌浸出率达到了24.12%,而氧化铁硫杆菌处理的锌浸出渣锌浸出率达到了33.86%,氧化铁硫杆菌处理锌浸出渣的锌浸出率明显高于根瘤菌。

  5. 利用硫杆菌淋滤电镀污泥中的重金属%Bio-leaching of heavy metals from electroplating sludge by Thiobacillus

    Institute of Scientific and Technical Information of China (English)

    施燕; 张太平; 李木桂; 南燕; 曹利明

    2008-01-01

    从广东云浮硫铁矿矿山酸性废水中分离得一株氧化亚铁硫杆菌(Thiobacillus ferrooxdans),从新兴县含硫化氢温泉中分离得一株氧化硫硫杆菌 (Thiobacillus thiooxidans), 并将其应用于电镀污泥的生物淋滤的研究,该污泥含铬、镍及铜分别为80.74 g/kg自然风干污泥、37.34g/kg自然风干污泥和13.42 g/kg自然风干污泥.利用未经驯化的氧化亚铁硫杆菌和氧化硫硫杆菌,以底物类型、菌液比、初始pH值和污泥浓度为四个因素,设置3个水平进行L9(34)正交实验,得出电镀污泥的最适淋滤条件:污泥浓度0.1%、硫酸亚铁和硫代硫酸钠作底物、菌液比T.f:T.t=:1:1、初始pH值2.0.为了将分离得的两种硫杆菌应用于更高浓度的电镀污泥,对所得菌进行驯化,以提高该菌种的重金属耐性,并应用于高浓度污泥的生物淋滤.经过驯化后的细菌,成功地适应了电镀污泥环境.结合上述最适条件,加入了合适的营养底物及还原剂之后,电镀污泥中的重金属,如铜、镍等,在30℃酸性好氧的环境中,能够在7天内被有效地淋滤出来,混合菌对污泥浓度为0.5%的污泥中铜的滤出率达90%以上,镍的滤出率40%以上;对1%的污泥的淋滤效果较差;对铬的淋滤效果不明显.本文还讨论了两株硫杆菌对高毒性电镀污泥的适应性.即在一定的污泥浓度范围内,氧化亚铁硫杆菌和氧化硫硫杆菌能够氧化底物,并产生硫酸将污泥中的重金属溶解,两株硫杆菌能够加快镍和铜的滤出效率.%The removal of heavy metals from electroplating sludge is important for its safe disposal and recycling.Two bacteria strains were separated to investigate the bio-leaching characteristics of heavy metals from electroplating sludge:Thiobacillus fer-rooxidans separated from acidic wastewater of a pyrite mine in Yunfu,Guangdong province,China,and Thiobacillus thiooxidans separated from hot springs containing H2S in Xinxing

  6. Feasibility of an innovative integrated process of simultaneous desulfurization and denitrification for high strength wastewater

    Institute of Scientific and Technical Information of China (English)

    WANG Ai-jie; LIU Chun-shuang; REN Nan-qi; DENG Xu-liang; WAN Chun-li; YU Zhen-guo; XU Xin

    2008-01-01

    An anaerobic expanding-bed reactor was adopted to investigate the feasibility of an innovative inte-grated process of simultaneous desulfurization and denitrification (SDD) for high strength wastewater. In the re-actor, beterotrophic bacteria (including sulfate reducing bacterium and denitrifying bacteria) and autotrophic bacteria (including Thiobacillus denitrificans) cooperated together by incubating and enriching functional bac-teria on different carriers in the anaerobic activated sludge. Synthetic wastewater with high concentrations of sul-fate and nitrate was employed. The experimental results showed that the removal efficiency of sulfate and nitrate was above 85%, elemental sulfur was observed while nitrate was absent in effluent. The balance of sulfur, ni-trogen and electron was discussed respectively, which indicated that the integrated SDD process could be actual-ized. These results might provide a guidance to further investigate the key factors affecting the integrated SDD process and to improve the efficiency of desulfurization and denitrification in wastewater treatment.

  7. Final Report: Molecular mechanisms and kinetics of microbial anaerobic nitrate-dependent U(IV) and Fe(II) oxidation

    Energy Technology Data Exchange (ETDEWEB)

    O' Day, Peggy A. [Univ. of California, Merced, CA (United States); Asta, Maria P. [Univ. of California, Merced, CA (United States); Kanematsu, Masakazu [Univ. of California, Merced, CA (United States); Beller, Harry [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Zhou, Peng [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Steefel, Carl [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-02-27

    In this project, we combined molecular genetic, spectroscopic, and microscopic techniques with kinetic and reactive transport studies to describe and quantify biotic and abiotic mechanisms underlying anaerobic, nitrate-dependent U(IV) and Fe(II) oxidation, which influences the long-term efficacy of in situ reductive immobilization of uranium at DOE sites. In these studies, Thiobacillus denitrificans, an autotrophic bacterium that catalyzes anaerobic U(IV) and Fe(II) oxidation, was used to examine coupled oxidation-reduction processes under either biotic (enzymatic) or abiotic conditions in batch and column experiments with biogenically produced UIVO2(s). Synthesis and quantitative analysis of coupled chemical and transport processes were done with the reactive transport modeling code Crunchflow. Research focused on identifying the primary redox proteins that catalyze metal oxidation, environmental factors that influence protein expression, and molecular-scale geochemical factors that control the rates of biotic and abiotic oxidation.

  8. Optimum condition in Cr3+ bioleaching of tannery sludge with Thiobacillus ferrooxidans LX5, Thiobacillus thiooxidans TS6 and Rhodotorula sp. R30%酵母菌与两种硫杆菌复合对污泥中三价铬的去除

    Institute of Scientific and Technical Information of China (English)

    王世梅; 周立祥; 黄峰源

    2006-01-01

    研究了氧化亚铁硫杆菌LX5(Thiobacillus ferrooxidans LX5)、氧化硫硫杆菌TS6(Thiobacillus thiooxidans TS6)和耐酸性酵母菌R30(Rhodotorula sp.R30)对重金属铬(Cr3+)的耐受性.结果表明,700mg/L的Cr3+对硫杆菌LX5、TS6的生长和氧化活性影响不大,但Cr3+浓度大于500mg/L时明显抑制酵母菌R30的生长.酵母菌R30与硫杆菌LX5和TS6复合能明显加速污泥淋滤的进程,最佳复合比为酵母菌R30接种量2.0%,硫杆菌LX5和TS6接种量10%.分别用含酵母菌R30数量为104个/mL和102个/mL的酸化污泥作接种物进行污泥淋滤,发现淋滤过程中pH值下降的速度没有明显差异,而在淋滤起始时添加2.0%的酵母菌R30,则淋滤反应提前36h结束.由此可见,在其它条件相同的污泥淋滤中,污泥中所含耐酸性酵母菌的数量是加快淋滤的关键.

  9. 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...

  10. Swimming Efficiency of Bacterium Escherichia Coli

    CERN Document Server

    Chattopadhyay, S; Wu, X L; Yeung, C; Chattopadhyay, Suddhashil; Moldovan, Radu; Yeung, Chuck

    2005-01-01

    We use in vivo measurements of swimming bacteria in an optical trap to determine fundamental properties of bacterial propulsion. In particular, we determine the propulsion matrix, which relates the angular velocity of the flagellum to the torques and forces propelling the bacterium. From the propulsion matrix dynamical properties such as forces, torques, swimming speed and power can be obtained from measurements of the angular velocity of the motor. We find significant heterogeneities among different individuals even though all bacteria started from a single colony. The propulsive efficiency, defined as the ratio of the propulsive power output to the rotary power input provided by the motors, is found to be 0.2%.

  11. Evidence of biogenic corrosion of titanium after exposure to a continuous culture of thiobacillus ferrooxidans grown in thiosulfate medium

    Energy Technology Data Exchange (ETDEWEB)

    Horn, J M; Martin, S I; Masterson, B

    2000-12-07

    Experiments were undertaken to evaluate extreme conditions under which candidate materials intended for use in a proposed nuclear waste repository might be susceptible to corrosion by endogenous microorganisms. Thiobucillus ferrooxidans, a sulfur-oxidizing bacterium, was grown in continuous culture using thiosulfate as an energy source; thiosulfate is oxidized to sulfate as a metabolic endproduct by this organism. Culture conditions were optimized to produce a high-density, metabolically active culture throughout a period of long term incubation in the presence of Alloy 22 (a high nickel-based alloy) and Titanium grade 7 (Tigr7) material coupons. After seven months incubation under these conditions, material coupons were withdrawn and analyzed by high resolution microscopy and energy dispersive x-ray analyses. Alloy 22 coupons showed no detectable signs of corrosion. Tigr7, however, demonstrated distinct roughening of the coupon surface, and [presumably solubilized and precipitated] titanium was detected on Alloy 22 coupons incubated in the same T. ferrooxiduns culture vessel. Control coupons of these materials incubated in sterile thiosulfate medium did not demonstrate any signs of corrosion, thus showing that observed corrosive effects were due to the T. ferrooxidans metabolic activities. T. ferrooxidans intermediates of thiosulfate oxidation or sulfate may have caused the corrosive effects observed on Tigr7.

  12. Biological leaching of Mn, Al, Zn, Cu and Ti in an anaerobic sewage sludge effectuated by Thiobacillus ferrooxidans and its effect on metal partitioning.

    Science.gov (United States)

    Lombardi, Ana T; Garcia, Oswaldo

    2002-07-01

    The chemical fractionation and bioleaching of Mn, Al, Zn, Cu and Ti in municipal sewage sludge were investigated using Thiobacillus ferrooxidans as leaching microorganism. As a result of the bacterial activity, ORP increase and pH reduction were observed. Metal solubilization was accomplished only in experimental systems supplemented with energy source (Fe(II)). The solubilization efficiency approached approximately 80% for Mn and Zn, 24% for Cu, 10% for Al and 0.2% for Ti. The chemical fractionation of Mn, Al, Zn, Cu and Ti was investigated using a five-step sequential extraction procedure employing KNO3, KF, Na4P2O7, EDTA and HNO3. The results show that the bioleaching process affected the partitioning of Mn and Zn, increasing its percentage of elution in the KNO3 fraction while reducing it in the KF, Na4P2O7 and EDTA fractions. No significant effect was detected on the partitioning of Cu and Al. However, quantitatively the metals Mn, Zn, Cu and Al were extracted with higher efficiency after the bacterial activity. Titanium was unaffected by the bioleaching process in both qualitative and quantitative aspects.

  13. Urease Activity in an Autotrophic Bacteria Thiobacillus thiooxidan%氧化硫硫杆菌产脲酶的研究

    Institute of Scientific and Technical Information of China (English)

    刘晓娟

    2011-01-01

    Urease activity was found in the fermentation of Thiobacillus thiooxidans. The initial concentration of sulfur and urea, and initial pH in the medium influenced urease activity, maximum urease activity crude enzyme being noted after 96h of fermentation with 24g/L initial concentration of sulfur and 0.1g/L of urea, and on nature pH 5.82. There was no relevant paper reported.%本文通过对氧化硫硫杆菌培养条件的研究,在氧化硫硫杆菌的发酵液中,发现了脲酶酶活.培养液中的初始尿素浓度、硫粉浓度以及初始pH影响脲酶活力,当培养液初始尿素浓度为0.1g/L、硫粉浓度为24g/L、初始pH为5.82,培养96小时后,可以在发酵液中测得最大脲酶酶活.本文的研究内容国内外尚未见报道.

  14. Biodegradation of heavy oils by halophilic bacterium

    Institute of Scientific and Technical Information of China (English)

    Ruixia Hao; Anhuai Lu

    2009-01-01

    A halophilic bacterial strain TM-1 was isolated from the reservoir of the Shengli oil field in East China. Strain TM-1, which was found to be able to degrade crude oils, is a gram-positive non-motile bacterium with a coccus shape that can grow at temperatures of up to 58 ℃ and in 18% NaCl solution. Depending on the culture conditions, the organism may occur in tetrads. In addition, strain TM-1 pro-duced acid from glucose without gas formation and was catalase-negative. Furthermore, strain TM-I was found to be a facultative aer-obe capable of growth under anaerobic conditions. Moreover, it produced butylated hydroxytoluene, 1,2-benzenedicarboxylic acid-bis ester and dibutyl phthalate and could use different organic substrates. Laboratory studies indicated that strain TM-1 affected different heavy oils by degrading various components and by changing the chemical properties of the oils. In addition, growth of the bacterium in heavy oils resulted in the loss of aromatic hydrocarbons, resins and asphaltenes, and enrichment with light hydrocarbons and an overall redistribution of these hydrocarbons.

  15. Diffusion of magnetotactic bacterium in rotating magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Cebers, A., E-mail: aceb@tesla.sal.l [Department of Physics, University of Latvia, Zellu 8, Ri-bar ga, LV-1002 (Latvia)

    2011-02-15

    Swimming trajectory of a magnetotactic bacterium in a rotating magnetic field is a circle. Random reversals of the direction of the bacterium motion induces a random walk of the curvature center of the trajectory. In assumption of the distribution of the switching events according to the Poisson process the diffusion coefficient is calculated in dependence on the frequency of the rotating field and the characteristic time between the switching events. It is confirmed by the numerical simulation of the random walk of the bacterium in the rotating magnetic field. - Research highlights: Random switching of the flagella leads to diffusion of a bacterium in the field. Mean square displacement of the curvature center is proportional to time. Diffusion coefficient depends on the period of a rotating field. At zero frequency diffusion coefficient is the same as for a tumbling bacterium.

  16. Fluctuation-Enhanced Sensing of Bacterium Odors

    CERN Document Server

    Chang, Hung-Chih; King, Maria D; Kwan, Chiman

    2009-01-01

    The goal of this paper is to explore the possibility to detect and identify bacteria by sensing their odor via fluctuation-enhanced sensing with commercial Taguchi sensors. The fluctuations of the electrical resistance during exposure to different bacterial odors, Escherichia coli and anthrax-surrogate Bacillus subtilis, have been measured and analyzed. In the present study, the simplest method, the measurement and analysis of power density spectra was used. The sensors were run in the normal heated and the sampling-and-hold working modes, respectively. The results indicate that Taguchi sensors used in these fluctuation-enhanced modes are effective tools of bacterium detection and identification even when they are utilizing only the power density spectrum of the stochastic sensor signal.

  17. The chemical formula of a magnetotactic bacterium.

    Science.gov (United States)

    Naresh, Mohit; Das, Sayoni; Mishra, Prashant; Mittal, Aditya

    2012-05-01

    Elucidation of the chemical logic of life is one of the grand challenges in biology, and essential to the progress of the upcoming field of synthetic biology. Treatment of microbial cells explicitly as a "chemical" species in controlled reaction (growth) environments has allowed fascinating discoveries of elemental formulae of a few species that have guided the modern views on compositions of a living cell. Application of mass and energy balances on living cells has proved to be useful in modeling of bioengineering systems, particularly in deriving optimized media compositions for growing microorganisms to maximize yields of desired bio-derived products by regulating intra-cellular metabolic networks. In this work, application of elemental mass balance during growth of Magnetospirillum gryphiswaldense in bioreactors has resulted in the discovery of the chemical formula of the magnetotactic bacterium. By developing a stoichiometric equation characterizing the formation of a magnetotactic bacterial cell, coupled with rigorous experimental measurements and robust calculations, we report the elemental formula of M. gryphiswaldense cell as CH(2.06)O(0.13)N(0.28)Fe(1.74×10(-3)). Remarkably, we find that iron metabolism during growth of this magnetotactic bacterium is much more correlated individually with carbon and nitrogen, compared to carbon and nitrogen with each other, indicating that iron serves more as a nutrient during bacterial growth rather than just a mineral. Magnetotactic bacteria have not only invoked some interest in the field of astrobiology for the last two decades, but are also prokaryotes having the unique ability of synthesizing membrane bound intracellular organelles. Our findings on these unique prokaryotes are a strong addition to the limited repertoire, of elemental compositions of living cells, aimed at exploring the chemical logic of life.

  18. A influência do Thiobacillus Thiooxidans na corrosão do aço inoxidável 430 em H2SO4 1 mol L-1 The influence of Thiobacillus Thiooxidans in the corrosios of stainless steel 430 in H2SO4 1 mol L-1

    Directory of Open Access Journals (Sweden)

    Priscila Anunziato

    2010-03-01

    Full Text Available A corrosão microbiológica é um dos grandes problemas industriais da atualidade. O objetivo desse trabalho é estudar a influência da Thiobacillus Thiooxidans (TT na corrosão do aço inoxidável 430 em H2SO4 1mol L-1. Nesse trabalho, foram empregadas as técnicas de: medidas gravimétricas, polarização anódica potenciostática (PA e potenciodinâmica cíclica (PC, espectroscopia de impedância eletroquímica (EIE, microscopia óptica e eletrônica de varredura (MEV. Os resultados gravimétricos mostraram que, em 180 minutos de imersão do aço no meio contendo TT, há a formação de biofilme, o qual, inicialmente, bloqueia a corrosão do metal. A PA mostrou que o TT atua catalisando a reação de oxidação do aço 430 nesse meio, sendo que resultados semelhantes foram obtidos pela EIE. A aplicação da PC, na região passiva do aço 430, nesse meio, gera a inibição da geração de biofilmes em sua superfície, resultado este comprovado pela MEV.Microbiological corrosion is a big problem in today's industry. The objective of this study is to understand the influence of Thiobacillus Thiooxidans (TT in the corrosion of 430 stainless steel (SS in H2SO4 1 mol L-1. The techniques employed were: measures of mass loss, cyclic potentiodynamic polarization (CPP and potentiostatic anodic polarization (PAP, electrochemical impedance spectroscopy (EIS, optical (OM and scanning electron microscopy (SEM. The gravimetric results showed that with the steel immersed for 180 minutes in a solution containing TT, biofilm formation occurs, which initially blocks the corrosion of the metal. The PAP has shown that the TT works as a catalizer for the oxidating reaction of 430 SS, similar results were obtained by EIS. The implementation of CPP in the passive region of the 430 steel, in this solution, inhibits biofilm generation on the surface, which was confirmed by SEM.

  19. Tentative Study on a New Way of Simultaneous Desulfurization and Denitrification%一种利用脱氮硫杆菌的同步脱硫反硝化新工艺研究

    Institute of Scientific and Technical Information of China (English)

    王爱杰; 杜大仲; 任南琪; 程翔; 刘春爽

    2005-01-01

    Thiobacillus denitrificans, a kind of autotrophic facultative bacteria, can oxidize sulfide into elemental sulfur or sulfate when nitrate was adopted as its electron accepter and carbon dioxide as its carbon resource under anoxic or anaerobic environment. In this way, nitrate is converted into nitrogen. In addition, Thiobacillus denitrificans can accumulate sulfur extracellularly. In this study, in a process of simultaneous desulfurization and denitrification, a strain of Thiobacillus denitrificans is employed as sulfur-producer in the treatment of wastewater containing sulfide and nitrate. The key factors affecting this process are investigated through batch tests. The experimental results indicate that the sulfide concentration and the ratio of sulfide to nitrate (S2-/NO-3) in the respectively, in order to achieve high conversion of sulfur.

  20. Tentative Study on a New Way of Simultaneous Desulfurization and Denitrification

    Institute of Scientific and Technical Information of China (English)

    王爱杰; 杜大仲; 任南琪; 程翔; 刘春爽

    2005-01-01

    Thiobacillus denitrificans, a kind of autotrophic facultative bacteria, can oxidize sulfide into elemental sulfur or sulfate when nitrate was adopted as its electron accepter and carbon dioxide as its carbon resource under anoxic or anaerobic environment. In this way, nitrate is converted into nitrogen. In addition, Thiobacillus denitrificans can accumulate sulfur extracellularly. In this study, in a process of simultaneous desulfurization and denitrification, a strain of Thiobacillus denitrificans is employed as sulfur-producer in the treatment of wastewater containing sulfide and nitrate. The key factors affecting this process are investigated through batch tests. The experimental results indicate that the sulfide concentration and the ratio of sulfide to nitrate (S2-/NO3-) in the influent are the key factors, and their suitable values are suggested to be 5/3 and no more than 300mg·L-1, respectively, in order to achieve high conversion of sulfur.

  1. Experimental evolution of aging in a bacterium

    Directory of Open Access Journals (Sweden)

    Stearns Stephen C

    2007-07-01

    Full Text Available Abstract Background Aging refers to a decline in reproduction and survival with increasing age. According to evolutionary theory, aging evolves because selection late in life is weak and mutations exist whose deleterious effects manifest only late in life. Whether the assumptions behind this theory are fulfilled in all organisms, and whether all organisms age, has not been clear. We tested the generality of this theory by experimental evolution with Caulobacter crescentus, a bacterium whose asymmetric division allows mother and daughter to be distinguished. Results We evolved three populations for 2000 generations in the laboratory under conditions where selection was strong early in life, but very weak later in life. All populations evolved faster growth rates, mostly by decreasing the age at first division. Evolutionary changes in aging were inconsistent. The predominant response was the unexpected evolution of slower aging, revealing the limits of theoretical predictions if mutations have unanticipated phenotypic effects. However, we also observed the spread of a mutation causing earlier aging of mothers whose negative effect was reset in the daughters. Conclusion Our results confirm that late-acting deleterious mutations do occur in bacteria and that they can invade populations when selection late in life is weak. They suggest that very few organisms – perhaps none- can avoid the accumulation of such mutations over evolutionary time, and thus that aging is probably a fundamental property of all cellular organisms.

  2. Proteome-wide dataset generated by iTRAQ-3DLCMS/MS technique for studying the role of FerB protein in oxidative stress in Paracoccus denitrificans

    Directory of Open Access Journals (Sweden)

    Vendula Pernikářová

    2015-09-01

    Full Text Available 3DLC protein- and peptide-fractionation technique combined with iTRAQ-peptide labeling and Orbitrap mass spectrometry was employed to quantitate Paracoccus dentirificans total proteome with maximal coverage. This resulted in identification of 24,948 peptides representing 2627 proteins (FDR<0.01 in P. dentirificans wild type and ferB mutant strains grown in the presence or absence of methyl viologen as an oxidative stressor. The data were generated for assessment of FerB protein role in oxidative stress as published by Pernikářová et al.; proteomic responses to a methyl viologen-induced oxidative stress in the wild type and FerB mutant strains of P. denitrificans, J. Proteomics 2015;125:68–75. Dataset is supplied in the article.

  3. Taxonomic characterization of the cellulose-degrading bacterium NCIB 10462

    Energy Technology Data Exchange (ETDEWEB)

    Dees, C.; Ringleberg, D.; Scott, T.C. [Oak Ridge National Lab., TN (United States); Phelps, T. [Univ. of Tennessee, Knoxville, TN (United States)

    1994-06-01

    The gram negative cellulase-producing bacterium NCIB 10462 has been previously named Pseudomonas fluorescens subsp. or var. cellulosa. Since there is renewed interest in cellulose-degrading bacteria for use in bioconversion of cellulose to chemical feed stocks and fuels, we re-examined the characteristics of this microorganism to determine its proper taxonomic characterization and to further define it`s true metabolic potential. Metabolic and physical characterization of NCIB 10462 revealed that this was an alkalophilic, non-fermentative, gram negative, oxidase positive, motile, cellulose-degrading bacterium. The aerobic substrate utilization profile of this bacterium was found to have few characteristics consistent with a classification of P. fluorescens with a very low probability match with the genus Sphingomonas. Total lipid analysis did not reveal that any sphingolipid bases are produced by this bacterium. NCIB 10462 was found to grow best aerobically but also grows well in complex media under reducing conditions. NCIB 10462 grew slowly under full anaerobic conditions on complex media but growth on cellulosic media was found only under aerobic conditions. Total fatty acid analysis (MIDI) of NCIB 10462 failed to group this bacterium with a known pseudomonas species. However, fatty acid analysis of the bacteria when grown at temperatures below 37{degrees}C suggest that the organism is a pseudomonad. Since a predominant characteristic of this bacterium is it`s ability to degrade cellulose, we suggest it be called Pseudomonas cellulosa.

  4. Pangenome Evolution in the Marine Bacterium Alteromonas.

    Science.gov (United States)

    López-Pérez, Mario; Rodriguez-Valera, Francisco

    2016-06-03

    We have examined a collection of the free-living marine bacterium Alteromonas genomes with cores diverging in average nucleotide identities ranging from 99.98% to 73.35%, i.e., from microbes that can be considered members of a natural clone (like in a clinical epidemiological outbreak) to borderline genus level. The genomes were largely syntenic allowing a precise delimitation of the core and flexible regions in each. The core was 1.4 Mb (ca. 30% of the typical strain genome size). Recombination rates along the core were high among strains belonging to the same species (37.7-83.7% of all nucleotide polymorphisms) but they decreased sharply between species (18.9-5.1%). Regarding the flexible genome, its main expansion occurred within the boundaries of the species, i.e., strains of the same species already have a large and diverse flexible genome. Flexible regions occupy mostly fixed genomic locations. Four large genomic islands are involved in the synthesis of strain-specific glycosydic receptors that we have called glycotypes. These genomic regions are exchanged by homologous recombination within and between species and there is evidence for their import from distant taxonomic units (other genera within the family). In addition, several hotspots for integration of gene cassettes by illegitimate recombination are distributed throughout the genome. They code for features that give each clone specific properties to interact with their ecological niche and must flow fast throughout the whole genus as they are found, with nearly identical sequences, in different species. Models for the generation of this genomic diversity involving phage predation are discussed.

  5. DO对硫杆菌污泥调理系统脱水效能的影响%Effect of DO on Dewatering Efficiency of Sludge Conditioning System with Thiobacillus Thiooxidans

    Institute of Scientific and Technical Information of China (English)

    刘杰; 周健; 陈浬; 李彦澄; 杨志

    2013-01-01

    The existing sludge conditioning technology has low improvement efficiency of sludge dewatering and cannot meet the requirements of moisture content in sludge disposal.The conditioning of excess sludge with Thiobacillus Thiooxidans was proposed.The effect of DO on the dewatering efficiency of the excess sludge conditioning system with Thiobacillus Thiooxidans was investigated.When DO was 6 mg/L,the moisture content of dewatered sludge decreased from 75.5% to 63.6%.The contents of protein,humic substance,polysaccharides in EPS decreased to 3.67 mg/gVSS,3.15 mg/gVSS and 16.17mg/gVSS respectively.The bound water decreased from 2.63 g/gDS to 1.48 g/gDS.The Zeta potential decreased from-14.9 mV to 0.27 mV.The average particle size of dewatered sludge increased from 20.19 μm to 34.51 μm.The conditioning system of excess sludge with Thiobacillus Thiooxidans had significant improvements on sludge dewatering performance.%针对现有污泥调理技术对污泥脱水性能改善效能低,难以达到现行污泥处置标准对含水率要求的问题,提出了剩余污泥氧化硫硫杆菌生物调理技术,考察了DO对剩余污泥硫杆菌生物调理系统深度脱水效能的影响.在DO为6 mg/L条件下,氧化硫硫杆菌生物调理系统调理污泥脱水后的含水率由75.5%降至63.6%;EPS中蛋白质、腐殖质、多糖分别减少为3.67、3.15、16.17mg/gVSS,污泥结合水含量从2.63 g/gDS降低至1.48 g/gDS;污泥Zeta电位从-14.9 mV降低至0.27 mV,污泥絮体颗粒平均粒径由20.19 μm增大到34.51 μm,硫杆菌生物调理系统对污泥脱水性能改善显著.

  6. Bioleaching of heavy metal from sewage sludge by isolated Thiobacillus thiooxidan%污泥中氧化硫硫杆菌的分离及其应用效果

    Institute of Scientific and Technical Information of China (English)

    温烨明; 王清萍; 林鸿雁; 陈祖亮

    2009-01-01

    以硫粉为能源物质,采用Waksman液体培养基培养,然后以Waksman固体培养基平板接种法直接从污泥中分离出1株高度嗜酸的氧化硫硫杆菌(Thiobacillus thiooxidan).该菌株适应环境速度快,易于驯化.序批式试验法研究表明,接种该菌株进行污泥生物淋滤可有效溶出污泥中的重金属.经过14 d的生物淋滤,Zn、Cu、Pb、Cr的最高去除率分别达到97%、96%、43%、44%.

  7. Microbial reduction of SO{sub 2} and NO{sub x} as a means of by-product recovery/disposal from regenerable processes for the desulfurization of flue gas. Technical progress report, September 11, 1992--December 11, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Sublette, K.L.

    1992-12-31

    With the continual increase in the utilization of high sulfur and high nitrogen containing fossil fuels, the release of airborne pollutants into the environment has become a critical problem. The fuel sulfur is converted to SO{sub 2} during combustion. Fuel nitrogen and a fraction of the nitrogen from the combustion air are converted to nitric oxide and nitrogen dioxide, NO{sub x}. For the past five years Combustion Engineering (now Asea Brown Boveri or ABB) and, since 1986, the University of Tulsa (TU) have been investigating the oxidation of H{sub 2}S by the facultatively anaerobic and autotrophic bacterium Thiobacillus denitrificans and have developed a process, concept for the microbial removal of H{sub 2}S from a gas stream the simultaneous removal of SO{sub 2} and NO by D. desulfuricans and T. denitrificans co-cultures and cultures-in-series was demonstrated. These systems could not be sustained due to NO inhibition of D. desulfuricans. However, a preliminary economic analysis has shown that microbial reduction of SO{sub 2} to H{sub 2}S with subsequent conversion to elemental sulfur by the Claus process is both technically and economically feasible if a less expensive carbon and/or energy source can be found. It has also been demonstrated that T. denitrificans can be grown anaerobically on NO(g) as a terminal electron acceptor with reduction to elemental nitrogen. Microbial reduction of NO{sub x} is a viable process concept for the disposal of concentrated streams of NO{sub x} as may be produced by certain regenerable processes for the removal of SO{sub 2} and NO{sub x} from flue gas.

  8. Genome of a mosquito-killing bacterium decoded

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Researchers with the CAS Wuhan Institute of Virology (WHIOV) recently completed the genome sequencing of a mosquitocidal bacterium Bacillus shaericus C3-41. The feat, first of its kind in China, is expected to further promote the bio-control studies of mosquitoes.

  9. The physiology of the filamentous bacterium Microthrix parvicella

    NARCIS (Netherlands)

    Slijkhuis, H.

    1983-01-01

    A study has been made of the physiology of Microthrix parvicella. This filamentous bacterium often causes poor settleability of activated sludge in oxidation ditches supplied with domestic sewage. The organism was found to utilize only long chain fatty acids (preferably in esterified form) as carbon

  10. CRYSTAL-STRUCTURE OF AN ELECTRON-TRANSFER COMPLEX BETWEEN METHYLAMINE DEHYDROGENASE AND AMICYANIN

    NARCIS (Netherlands)

    CHEN, LY; DURLEY, R; POLIKS, BJ; HAMADA, K; CHEN, ZW; MATHEWS, FS; DAVIDSON, VL; SATOW, Y; HUIZINGA, E; VELLIEUX, FMD; HOL, WGJ

    1992-01-01

    The crystal structure of the complex between the quinoprotein methylamine dehydrogenase (MADH) and the type I blue copper protein amicyanin, both from Paracoccus denitrificans, has been determined at 2.5-angstrom resolution using molecular replacement. The search model was MADH from Thiobacillus ver

  11. Rock Phosphate Solubilization Mechanisms of One Fungus and One Bacterium

    Institute of Scientific and Technical Information of China (English)

    LIN Qi-mei; ZHAO Xiao-rong; ZHAO Zi-juan; LI Bao-guo

    2002-01-01

    Many microorganisms can dissolve the insoluble phosphates like apatite. However, the mechanisms are still not clear. This study was an attempt to investigate the mechanisms of rock phosphate solubilization by an Aspergillus 2TCiF2 and an Arthrobacter1TCRi7. The results indicated that the fungus produced a large amount of organic acids, mainly oxalic acid. The total quantity of the organic acids produced by the fungus was 550 times higher than that by the bacterium. Different organic acids had completely different capacities to solubilize the rock. Oxalic acid and citric acid had stronger capacity to dissolve the rock than malic acid, tartaric acid, lactic acid, acetic acid, malonic acid and succinic acid. The fungus solubilized the rock through excreting both proton and organic acids. The rock solubilization of the bacterium depended on only proton.

  12. A Streamlined Strategy for Biohydrogen Production with an Alkaliphilic Bacterium

    Energy Technology Data Exchange (ETDEWEB)

    Elias, Dwayne A [ORNL; Wall, Judy D. [University of Missouri; Mormile, Dr. Melanie R. [Missouri University of Science and Technology; Begemann, Matthew B [University of Wisconsin, Madison

    2012-01-01

    Biofuels are anticipated to enable a shift from fossil fuels for renewable transportation and manufacturing fuels, with biohydrogen considered attractive since it could offer the largest reduction of global carbon budgets. Currently, biohydrogen production remains inefficient and heavily fossil fuel-dependent. However, bacteria using alkali-treated biomass could streamline biofuel production while reducing costs and fossil fuel needs. An alkaliphilic bacterium, Halanaerobium strain sapolanicus, is described that is capable of biohydrogen production at levels rivaling neutrophilic strains, but at pH 11 and hypersaline conditions. H. sapolanicus ferments a variety of 5- and 6- carbon sugars derived from hemicellulose and cellulose including cellobiose, and forms the end products hydrogen and acetate. Further, it can also produce biohydrogen from switchgrass and straw pretreated at temperatures far lower than any previously reported and in solutions compatible with growth. Hence, this bacterium can potentially increase the efficiency and efficacy of biohydrogen production from renewable biomass resources.

  13. Initiation of chromosomal replication in predatory bacterium Bdellovibrio bacteriovorus

    Directory of Open Access Journals (Sweden)

    Lukasz Makowski

    2016-11-01

    Full Text Available Bdellovibrio bacteriovorus is a small Gram-negative predatory bacterium that attacks other Gram-negative bacteria, including many animal, human, and plant pathogens. This bacterium exhibits a peculiar biphasic life cycle during which two different types of cells are produced: non-replicating highly motile cells (the free-living phase and replicating cells (the intracellular-growth phase. The process of chromosomal replication in B. bacteriovorus must therefore be temporally and spatially regulated to ensure that it is coordinated with cell differentiation and cell cycle progression. Recently, B. bacteriovorus has received considerable research interest due to its intriguing life cycle and great potential as a prospective antimicrobial agent. Although we know that chromosomal replication in bacteria is mainly regulated at the initiation step, no data exists about this process in B. bacteriovorus. We report the first characterization of key elements of initiation of chromosomal replication – DnaA protein and oriC region from the predatory bacterium, B. bacteriovorus. In vitro studies using different approaches demonstrate that the B. bacteriovorus oriC (BdoriC is specifically bound and unwound by the DnaA protein. Sequence comparison of the DnaA-binding sites enabled us to propose a consensus sequence for the B. bacteriovorus DnaA box (5’-NN(A/TTCCACA-3’. Surprisingly, in vitro analysis revealed that BdoriC is also bound and unwound by the host DnaA proteins (relatively distantly related from B. bacteriovorus. We compared the architecture of the DnaA–oriC complexes (orisomes in homologous (oriC and DnaA from B. bacteriovorus and heterologous (BdoriC and DnaA from prey, E. coli or P. aeruginosa systems. This work provides important new entry points toward improving our understanding of the initiation of chromosomal replication in this predatory bacterium.

  14. Biosorption of heavy metals by a marine bacterium

    Energy Technology Data Exchange (ETDEWEB)

    Iyer, Anita [Central Salt and Marine Chemicals Research Institute, Bhavnagar 364002, Gujarat (India); Mody, Kalpana [Central Salt and Marine Chemicals Research Institute, Bhavnagar 364002, Gujarat (India)]. E-mail: khmody@csmcri.org; Jha, Bhavanath [Central Salt and Marine Chemicals Research Institute, Bhavnagar 364002, Gujarat (India)

    2005-03-01

    Heavy metal chelation property of exopolysaccharide produced by Enterobacter cloaceae, a marine bacterium, isolated from the West Coast of India, is reported in this paper. The exopolysaccharide demonstrated excellent chelating properties with respect to cadmium (65%) followed by copper (20%) and cobalt (8%) at 100 mg/l heavy metal concentration. However, it could not chelate mercury. A comparative study of the percentage biosorption of the above mentioned metals is presented here.

  15. Growth of a Strictly Anaerobic Bacterium on Furfural (2-Furaldehyde)

    OpenAIRE

    Brune, Gerhard; Schoberth, Siegfried M.; Sahm, Hermann

    1983-01-01

    A strictly anaerobic bacterium was isolated from a continuous fermentor culture which converted the organic constituents of sulfite evaporator condensate to methane and carbon dioxide. Furfural is one of the major components of this condensate. This furfural isolate could degrade furfural as the sole source of carbon and energy in a defined mineral-vitamin-sulfate medium. Acetic acid was the major fermentation product. This organism could also use ethanol, lactate, pyruvate, or fumarate and c...

  16. Biotransformation of citrinin to decarboxycitrinin using an organic solvent-tolerant marine bacterium, Moraxella sp. (MB1)

    Digital Repository Service at National Institute of Oceanography (India)

    PrabhaDevi; Naik, C.G.; Rodrigues, C.

    . In the present study, we used an organic solvent-tolerant marine bacterium, Moraxella sp. MB1. 16S rRNA sequencing revealed that the bacterium shows 98% similarity with an uncultured marine bacterium with gene bank accession number AY936933. This bacterium...

  17. Isolation and characterization of the moxJ, moxG, moxI, and moxR genes of Paracoccus denitrificans: inactivation of moxJ, moxG, and moxR and the resultant effect on methylotrophic growth.

    OpenAIRE

    Van Spanning, R J; Wansell, C W; de Boer, T.; Hazelaar, M J; Anazawa, H; Harms, N.; Oltmann, L F; Stouthamer, A H

    1991-01-01

    By using the moxF gene encoding the large fragment of methanol dehydrogenase as a probe, a downstream linked chromosomal fragment was isolated from a genomic bank of Paracoccus denitrificans. The nucleotide sequence of the fragment was determined and revealed the 3' part of moxF, four additional open reading frames, and the 5' part of a sixth one. The organization and deduced amino acid sequences of the first three frames downstream from moxF were found to be largely homologous to the moxJ, m...

  18. Salt-inducible promoter derivable from a lactic acid bacterium, and its use in a lactic acid bacterium for production of a desired protein

    NARCIS (Netherlands)

    Sanders, Jan Willem; Kok, Jan; Venema, Gerard; Ledeboer, Adrianus Marinus

    1998-01-01

    The invention provides a salt-inducible promoter present in SEQ ID NO: 10 and derivable from a lactic acid bacterium in isolation from the coding sequence normally controlled by said promoter in a wild-type lactic acid bacterium, with modifications and important parts thereof. Also provided are a re

  19. 氧化硫硫杆菌和芽孢杆菌协作下Q235钢腐蚀行为%Corrosion behavior of steel Q235 co-influenced by Thiobacillus thiooxidans and Bacillus

    Institute of Scientific and Technical Information of China (English)

    杜娟; 李松梅; 刘建华; 于美

    2014-01-01

    采用表面分析技术、失重法和电化学测试技术研究了Q235钢在氧化硫硫杆菌(T.t,Thiobacillus thiooxidans)和芽孢杆菌(Bacillus)协同作用下的腐蚀行为.扫描电镜结果表明,与单菌体系相比,混菌体系会形成最为致密的生物膜;混菌体系中浸泡的试样表面会出现不同于单菌体系的圆形蚀坑.腐蚀失重结果表明,混菌中试样的腐蚀速率介于2个单菌体系之间.交流阻抗结果表明,混菌体系浸泡2天后试样表面出现2个时间常数,表面膜层电阻经历了先增大后减小的过程.

  20. Influence of plaque-forming bacterium, Rhodobacteraceae sp. on the growth of Chlorella vulgaris.

    Science.gov (United States)

    Chen, Zhangran; Zhang, Jingyan; Lei, Xueqian; Zhang, Bangzhou; Cai, Guanjing; Zhang, Huajun; Li, Yi; Zheng, Wei; Tian, Yun; Xu, Hong; Zheng, Tianling

    2014-10-01

    Experiments were conducted to find out the molecular features, infection process of a special alga plaque-forming microorganism and its potential influence on the biomass of Chlorella vulgaris during the infection process. Direct contact between the algal cell and the bacterium may be the primary steps needed for the bacterium to lyse the alga. Addition of C. vulgaris cells into f/2 medium allowed us obtain the object bacterium. The 16S rRNA gene sequence comparisons results showed that the plaque-forming bacterium kept the closest relationship with Labrenzia aggregata IAM 12614(T) at 98.90%. The existence of the bacterium could influence both the dry weight and lipid content of C. vulgaris. This study demonstrated that direct cell wall disruption of C. vulgaris by the bacterium would be a potentially effective method to utilize the biomass of microalgae.

  1. Research Progress and Perspectives of Nitrogen Fixing Bacterium, Gluconacetobacter diazotrophicus, in Monocot Plants

    Directory of Open Access Journals (Sweden)

    N. Eskin

    2014-01-01

    Full Text Available Gluconacetobacter diazotrophicus is a nitrogen fixing bacterium originally found in monocotyledon sugarcane plants in which the bacterium actively fixes atmosphere nitrogen and provides significant amounts of nitrogen to plants. This bacterium mainly colonizes intercellular spaces within the roots and stems of plants and does not require the formation of the complex root organ like nodule. The bacterium is less plant/crop specific and indeed G. diazotrophicus has been found in a number of unrelated plant species. Importantly, as the bacterium was of monocot plant origin, there exists a possibility that the nitrogen fixation feature of the bacterium may be used in many other monocot crops. This paper reviews and updates the research progress of G. diazotrophicus for the past 25 years but focuses on the recent research development.

  2. Factors Affecting Zebra Mussel Kill by the Bacterium Pseudomonas fluorescens

    Energy Technology Data Exchange (ETDEWEB)

    Daniel P. Molloy

    2004-02-24

    The specific purpose of this research project was to identify factors that affect zebra mussel kill by the bacterium Pseudomonas fluorescens. Test results obtained during this three-year project identified the following key variables as affecting mussel kill: treatment concentration, treatment duration, mussel siphoning activity, dissolved oxygen concentration, water temperature, and naturally suspended particle load. Using this latter information, the project culminated in a series of pipe tests which achieved high mussel kill inside power plants under once-through conditions using service water in artificial pipes.

  3. Liver abscess associated with an oral flora bacterium Streptococcus anginosus

    Directory of Open Access Journals (Sweden)

    Hava Yılmaz

    2012-03-01

    Full Text Available Viridans group Streptococcus, a bacterium of the oral flora has a low-virulence and rarely causes liver abscess. A 40-yearoldmale patient was admitted to the hospital complaining of high fever and malaise. A physical examination revealedpoor oral hygiene; there were caries on many teeth, and he had hepatomegaly. A hepatic abscess was identified inhis abdominal tomography. Streptococcus anginosus was isolated from the drainage material, and the bile ducts werenormal in his MRI cholangiography. An immunocompetent case of liver abscess caused by Streptococcus anginosusoriginated most probably from oral flora is presented here. J Microbiol Infect Dis 2012; 2(1:33-35

  4. Structure of a new azurin from the denitrifying bacterium Alcaligenes xylosoxidans at high resolution.

    Science.gov (United States)

    Dodd, F E; Hasnain, S S; Abraham, Z H; Eady, R R; Smith, B E

    1995-11-01

    It has been reported previously that Alcaligenes xylosoxidans (NC1MB 11015) grown under denitrifying conditions produces two azurins instead of the single previously identified azurin [Dodd, Hasnain, Hunter, Abraham, Debenham, Kanzler, Eldridge, Eady, Ambler & Smith (1995). Biochemistry. In the press]. The new azurin, called azurin II, has been crystallized as blue elongated rectangular prisms with the tetragonal space group P4(1)22 and unit-cell parameters a = b = 52.65, c = 100.63 A. X-ray crystallographic data extending to 1.9 A resolution were collected by the Weissenberg method using 200 x 400 mm image plates and synchrotron X-rays of wavelength 0.97 A. The three-dimensional structure of azurin II has been solved by the molecular-replacement method using the structure of azurin from Alcaligenes denitrificans NCTC 8582 with which this new azurin shows a close homology. The quality of the initial map was sufficient to predict a number of sequence differences. The model is currently refined to an R-factor of 18.8% with X-ray data between 8.5 and 1.9 A. The final model of 961 protein atoms, one Cu atom and 50 water molecules has r.m.s. deviations from ideality of 0.009 A for bond lengths and 1.7 degrees for bond angles. The overall structure is similar to that of the azurin from A. denitrificans NCTC 8582. It has a beta-barrel structure with the Cu atom located near the top end of the molecule. The Cu atom is coordinated to Ndelta of His46 and His117 at 2.02 A and to Sgamma of Cys112 at 2.12 A, while the carbonyl O atom of Gly45 and Sdelta atom of Met121 provide the additional interactions at 2.75 and 3.26 A, respectively.

  5. Biological Control of Meloidogyne hapla Using an Antagonistic Bacterium

    Directory of Open Access Journals (Sweden)

    Jiyeong Park

    2014-09-01

    Full Text Available We examined the efficacy of a bacterium for biocontrol of the root-knot nematode (RKN Meloidogyne hapla in carrot (Daucus carota subsp. sativus and tomato (Solanum lycopersicum. Among 542 bacterial isolates from various soils and plants, the highest nematode mortality was observed for treatments with isolate C1-7, which was identified as Bacillus cereus based on cultural and morphological characteristics, the Biolog program, and 16S rRNA sequencing analyses. The population density and the nematicidal activity of B. cereus C1-7 remained high until the end of culture in brain heart infusion broth, suggesting that it may have sustainable biocontrol potential. In pot experiments, the biocontrol efficacy of B. cereus C1-7 was high, showing complete inhibition of root gall or egg mass formation by RKN in carrot and tomato plants, and subsequently reducing RKN damage and suppressing nematode population growth, respectively. Light microscopy of RKN-infected carrot root tissues treated with C1-7 showed reduced formation of gall cells and fully developed giant cells, while extensive gall cells and fully mature giant cells with prominent cell wall ingrowths formed in the untreated control plants infected with RKNs. These histopathological characteristics may be the result of residual or systemic biocontrol activity of the bacterium, which may coincide with the biocontrol efficacies of nematodes in pots. These results suggest that B. cereus C1-7 can be used as a biocontrol agent for M. hapla.

  6. Molybdate Reduction to Molybdenum Blue by an Antarctic Bacterium

    Directory of Open Access Journals (Sweden)

    S. A. Ahmad

    2013-01-01

    Full Text Available A molybdenum-reducing bacterium from Antarctica has been isolated. The bacterium converts sodium molybdate or Mo6+ to molybdenum blue (Mo-blue. Electron donors such as glucose, sucrose, fructose, and lactose supported molybdate reduction. Ammonium sulphate was the best nitrogen source for molybdate reduction. Optimal conditions for molybdate reduction were between 30 and 50 mM molybdate, between 15 and 20°C, and initial pH between 6.5 and 7.5. The Mo-blue produced had a unique absorption spectrum with a peak maximum at 865 nm and a shoulder at 710 nm. Respiratory inhibitors such as antimycin A, sodium azide, potassium cyanide, and rotenone failed to inhibit the reducing activity. The Mo-reducing enzyme was partially purified using ion exchange and gel filtration chromatography. The partially purified enzyme showed optimal pH and temperature for activity at 6.0 and 20°C, respectively. Metal ions such as cadmium, chromium, copper, silver, lead, and mercury caused more than 95% inhibition of the molybdenum-reducing activity at 0.1 mM. The isolate was tentatively identified as Pseudomonas sp. strain DRY1 based on partial 16s rDNA molecular phylogenetic assessment and the Biolog microbial identification system. The characteristics of this strain would make it very useful in bioremediation works in the polar and temperate countries.

  7. Molybdate reduction to molybdenum blue by an Antarctic bacterium.

    Science.gov (United States)

    Ahmad, S A; Shukor, M Y; Shamaan, N A; Mac Cormack, W P; Syed, M A

    2013-01-01

    A molybdenum-reducing bacterium from Antarctica has been isolated. The bacterium converts sodium molybdate or Mo⁶⁺ to molybdenum blue (Mo-blue). Electron donors such as glucose, sucrose, fructose, and lactose supported molybdate reduction. Ammonium sulphate was the best nitrogen source for molybdate reduction. Optimal conditions for molybdate reduction were between 30 and 50 mM molybdate, between 15 and 20°C, and initial pH between 6.5 and 7.5. The Mo-blue produced had a unique absorption spectrum with a peak maximum at 865 nm and a shoulder at 710 nm. Respiratory inhibitors such as antimycin A, sodium azide, potassium cyanide, and rotenone failed to inhibit the reducing activity. The Mo-reducing enzyme was partially purified using ion exchange and gel filtration chromatography. The partially purified enzyme showed optimal pH and temperature for activity at 6.0 and 20°C, respectively. Metal ions such as cadmium, chromium, copper, silver, lead, and mercury caused more than 95% inhibition of the molybdenum-reducing activity at 0.1 mM. The isolate was tentatively identified as Pseudomonas sp. strain DRY1 based on partial 16s rDNA molecular phylogenetic assessment and the Biolog microbial identification system. The characteristics of this strain would make it very useful in bioremediation works in the polar and temperate countries.

  8. Pathogenesis of helicobacter pylori infection: Bacterium and host relationship

    Directory of Open Access Journals (Sweden)

    Sokić-Milutinović Aleksandra

    2004-01-01

    Full Text Available Helicobacter pylori (H. pylori colonizes the gastric mucosa of a half of the mankind. Duodenal ulcer is found in 15-25%, t gastric ulcer in 13%, while gastric adenocarcinoma develops in 1% of all infected individuals. Pathogenesis of H. pylori infection is related to the virulence factors of the bacterium, environmental (dietary habits, hygiene, stress and host factors (age, sex, blood type. Colonization of the gastric mucosa is related to the motility of the bacterium, presence of lipopolysacharide (LPS and various bacterial enzymes. Gastric mucosal injury is the result of H. pylori LPS, vacuolization cytotoxin (vacA, cytotoxin associated protein (cagA, heat shock proteins and factors responsible for neutrophil chemotaxis and activity. H. pylori colonizes the gastric mucosa and zones of ectopic gastric epithelium. H. pylori infection is transmitted via oral-oral, fecal-oral and iatrogenic way (during endoscopy. Higher prevalence of the infection is associated with lower socioeconomic level, lack of drinking water, and living in a community. Acute H. pylori gastritis is superficial pangastritis progressing into the chronic phase after 7-10 days. Gastric mucosal atrophy and intestinal metaplasia can develop during the course of H. pylori infection. Clearly defined factors that influence the outcome of H. pylori infection include bacterial strain, distribution of gastritis, acid secretion and gastric mucosal atrophy.

  9. Structure and morphology of magnetite anaerobically-produced by a marine magnetotactic bacterium and a dissimilatory iron-reducing bacterium

    Science.gov (United States)

    Sparks, N. H. C.; Mann, S.; Bazylinski, D. A.; Lovley, D. R.; Jannasch, H. W.; Frankel, R. B.

    1990-04-01

    Intracellular crystals of magnetite synthesized by cells of the magnetotactic vibroid organism, MV-1, and extracellular crystals of magnetite produced by the non-magnetotactic dissimilatory iron-reducing bacterium strain GS-15, were examined using high-resolution transmission electron microscopy, electron diffraction and 57Fe Mo¨ssbauer spectroscopy. The magnetotactic bacterium contained a single chain of approximately 10 crystals aligned along the long axis of the cell. The crystals were essentially pure stoichiometric magnetite. When viewed along the crystal long axis the particles had a hexagonal cross-section whereas side-on they appeared as rectangules or truncated rectangles of average dimension, 53 × 35 nm. These findings are explained in terms of a three-dimensional morphology comprising a hexagonal prism of 110 faces which are capped and truncated by 111 end faces. Electron diffraction and lattice imaging studies indicated that the particles were structurally well-defined single crystals. In contrast, magnetite particles produced by the strain, GS-15 were irregular in shape and had smaller mean dimensions (14 nm). Single crystals were imaged but these were not of high structural perfection. These results highlight the influence of intracellular control on the crystallochemical specificity of bacterial magnetites. The characterization of these crystals is important in aiding the identification of biogenic magnetic materials in paleomagnetism and in studies of sediment magnetization.

  10. Dense populations of a giant sulfur bacterium in Namibian shelf sediments

    DEFF Research Database (Denmark)

    Schulz, HN; Brinkhoff, T.; Ferdelman, TG

    1999-01-01

    A previously unknown giant sulfur bacterium is abundant in sediments underlying the oxygen minimum zone of the Benguela Current upwelling system. The bacterium has a spherical cell that exceeds by up to 100-fold the biovolume of the largest known prokaryotes. On the basis of 16S ribosomal DNA seq...

  11. Hydrogen production by co-cultures of Lactobacillus and a photosynthetic bacterium, Rhodobacter sphaeroides RV

    Energy Technology Data Exchange (ETDEWEB)

    Asada, Yasuo; Ishimi, Katsuhiro [Department of General Education, College of Science and Technology, Nihon University, Narashinodai, Chiba 274-8501 (Japan); Tokumoto, Masaru; Aihara, Yasuyuki; Oku, Masayo; Kohno, Hideki [Department of Applied Molecular Chemistry, College of Industrial Technology, Nihon University, Izumi-cho, Chiba 275-8575 (Japan); Wakayama, Tatsuki; Miyake, Jun [Research Institute for Cell Engineering, National Institute of Advanced Industrial Science and Technology, Nakoji, Amagasaki, Hyogo 661-0974 (Japan); Tomiyama, Masamitsu [Genetic Diversity Department, National Institute of Agrobiological Science, Tsukuba, Ibaraki 305-8602 (Japan)

    2006-09-15

    Hydrogen production with glucose by using co-immobilized cultures of a lactic acid bacterium, Lactobacillus delbrueckii NBRC13953, and a photosynthetic bacterium, Rhodobacter sphaeroides RV, in agar gels was studied. Glucose was converted to hydrogen gas in a yield of 7.1mol of hydrogen per mole of glucose at a maximum under illuminated conditions. (author)

  12. Roseomonas gilardii subsp rosea, a pink bacterium associated with bacteremia: the first case in Thailand.

    Science.gov (United States)

    Srifuengfung, Somporn; Tharavichitkul, Prasit; Pumprueg, Satchana; Tribuddharat, Chanwit

    2007-09-01

    Roseomonas is a pink-pigmented, non-fermentative, gram-negative coccobacillus bacterium. Human infections caused by Roseomonas are very rare. We report the first case of bacteremia associated with Roseomonas gilardii subsp rosea in Thailand. The bacterium was isolated from blood culture and identified by cellular morphology, characteristics of colonies on blood agar, extensive biochemical tests and 16S ribosomal DNA sequencing.

  13. Genome Sequence of the Mycorrhizal Helper Bacterium Pseudomonas fluorescens BBc6R8

    OpenAIRE

    2014-01-01

    We report the draft genome sequence of the mycorrhizal helper bacterium Pseudomonas fluorescens strain BBc6R8. This is the first genome of a mycorrhizal helper bacterium. The draft genome contains 6,952,353 bp and is predicted to encode 6,317 open reading frames. Comparative genomic analyses will help to identify helper traits.

  14. Genome Sequence of the Mycorrhizal Helper Bacterium Pseudomonas fluorescens BBc6R8.

    Science.gov (United States)

    Deveau, A; Gross, H; Morin, E; Karpinets, T; Utturkar, S; Mehnaz, S; Martin, F; Frey-Klett, P; Labbé, J

    2014-01-09

    We report the draft genome sequence of the mycorrhizal helper bacterium Pseudomonas fluorescens strain BBc6R8. This is the first genome of a mycorrhizal helper bacterium. The draft genome contains 6,952,353 bp and is predicted to encode 6,317 open reading frames. Comparative genomic analyses will help to identify helper traits.

  15. The domestication of the probiotic bacterium Lactobacillus acidophilus.

    Science.gov (United States)

    Bull, Matthew J; Jolley, Keith A; Bray, James E; Aerts, Maarten; Vandamme, Peter; Maiden, Martin C J; Marchesi, Julian R; Mahenthiralingam, Eshwar

    2014-11-26

    Lactobacillus acidophilus is a Gram-positive lactic acid bacterium that has had widespread historical use in the dairy industry and more recently as a probiotic. Although L. acidophilus has been designated as safe for human consumption, increasing commercial regulation and clinical demands for probiotic validation has resulted in a need to understand its genetic diversity. By drawing on large, well-characterised collections of lactic acid bacteria, we examined L. acidophilus isolates spanning 92 years and including multiple strains in current commercial use. Analysis of the whole genome sequence data set (34 isolate genomes) demonstrated L. acidophilus was a low diversity, monophyletic species with commercial isolates essentially identical at the sequence level. Our results indicate that commercial use has domesticated L. acidophilus with genetically stable, invariant strains being consumed globally by the human population.

  16. Characterisation of an unusual bacterium isolated from genital ulcers.

    Science.gov (United States)

    Ursi, J P; van Dyck, E; Ballard, R C; Jacob, W; Piot, P; Meheus, A Z

    1982-02-01

    The preliminary characterisation of an unusual gram-negative bacillus isolated from genital ulcers in Swaziland is reported. Like Haemophilus ducreyi, it is an oxidase positive, nitrate-reductase-positive gram-negative rod that forms streptobacillary chains in some circumstances; it was therefore called the "ducreyi-like bacterium" (DLB). Distinguishing features of DLB are production of alpha-haemolysis on horse-blood agar, stimulation of growth by a microaerophilic atmosphere and by a factor produced by Staphylococcus aureus, a strongly positive porphyrin test, and a remarkable ability to undergo autolysis. DLB had a guanine + cytosine value of c. 50 mole% but it cannot be classified, even at the genus level, until more taxonomic data are obtained.

  17. A bacterium that degrades and assimilates poly(ethylene terephthalate).

    Science.gov (United States)

    Yoshida, Shosuke; Hiraga, Kazumi; Takehana, Toshihiko; Taniguchi, Ikuo; Yamaji, Hironao; Maeda, Yasuhito; Toyohara, Kiyotsuna; Miyamoto, Kenji; Kimura, Yoshiharu; Oda, Kohei

    2016-03-11

    Poly(ethylene terephthalate) (PET) is used extensively worldwide in plastic products, and its accumulation in the environment has become a global concern. Because the ability to enzymatically degrade PET has been thought to be limited to a few fungal species, biodegradation is not yet a viable remediation or recycling strategy. By screening natural microbial communities exposed to PET in the environment, we isolated a novel bacterium, Ideonella sakaiensis 201-F6, that is able to use PET as its major energy and carbon source. When grown on PET, this strain produces two enzymes capable of hydrolyzing PET and the reaction intermediate, mono(2-hydroxyethyl) terephthalic acid. Both enzymes are required to enzymatically convert PET efficiently into its two environmentally benign monomers, terephthalic acid and ethylene glycol.

  18. Genome analysis of the Anerobic Thermohalophilic bacterium Halothermothrix orenii

    Energy Technology Data Exchange (ETDEWEB)

    Mavromatis, Konstantinos; Ivanova, Natalia; Anderson, Iain; Lykidis, Athanasios; Hooper, Sean D.; Sun, Hui; Kunin, Victor; Lapidus, Alla; Hugenholtz, Philip; Patel, Bharat; Kyrpides, Nikos C.

    2008-11-03

    Halothermothirx orenii is a strictly anaerobic thermohalophilic bacterium isolated from sediment of a Tunisian salt lake. It belongs to the order Halanaerobiales in the phylum Firmicutes. The complete sequence revealed that the genome consists of one circular chromosome of 2578146 bps encoding 2451 predicted genes. This is the first genome sequence of an organism belonging to the Haloanaerobiales. Features of both Gram positive and Gram negative bacteria were identified with the presence of both a sporulating mechanism typical of Firmicutes and a characteristic Gram negative lipopolysaccharide being the most prominent. Protein sequence analyses and metabolic reconstruction reveal a unique combination of strategies for thermophilic and halophilic adaptation. H. orenii can serve as a model organism for the study of the evolution of the Gram negative phenotype as well as the adaptation under thermohalophilic conditions and the development of biotechnological applications under conditions that require high temperatures and high salt concentrations.

  19. Isolation of a bacterium that reductively dechlorinates tetrachloroethene to ethene

    Energy Technology Data Exchange (ETDEWEB)

    Maymo-Gatell, X.; Chien, Yueh-tyng; Zinder, S.H. [Cornell Univ., Ithaca, NY (United States)] [and others

    1997-06-06

    Tetrachloroethene is a prominent groundwater pollutant that can be reductively dechlorinated by mixed anaerobic microbial populations to the nontoxic product ethene. Strain 195, a coccoid bacterium that dechlorinates tetrachlorethene to ethene, was isolated and characterized. Growth of strain 195 with H{sub 2} and tetrachloroethene as the electron donor and acceptor pair required extracts from mixed microbial cultures. Growth of strain 195 was resistant to ampicillin and vancomycin; its cell wall did not react with a peptidoglycan-specific lectin and its ultrastructure resembled S-layers of Archaea. Analysis of the 16S ribosomal DNA sequence of strain 195 indicated that it is a eubacterium without close affiliation to any known groups. 24 refs., 4 figs., 1 tab.

  20. The lipopolysaccharide of a chloridazon-degrading bacterium.

    Science.gov (United States)

    Weisshaar, R; Lingens, F

    1983-12-01

    Lipopolysaccharide of a chloridazon-degrading bacterium was obtained by a two-stage extraction procedure with phenol/EDTA in a yield of 0.3% of dried bacteria. The carbohydrate moiety consisted of heptose, 3-deoxyoctulosonic acid and D-glucose in a molar ratio of 1:2:2 X 3. Lipid A was composed of 1 mol 2,3-diamino-2,3-dideoxy-D-glucose, 2 mol amide-bound and 2.6 mol ester-bound fatty acids/mol. Amide-bound fatty acids were 3-hydroxydodecanoic acid and 3-hydroxyhexadecanoic acid; dodecanoic acid and R-(-)-3-hydroxydodec-5-cis-enoic acid were found to be present in ester linkage. Under conditions of acidic hydrolysis, the latter was converted into the cis and trans isomers of 5-hexyltetrahydrofuran-2-acetic acid. Dodecanoic acid was demonstrated to be linked with the hydroxy groups of the amide-bound fatty acids. The taxonomic significance of these results, especially the demonstration of 2,3-diamino-2, 3-dideoxy-D-glucose, is discussed.

  1. Presence of an unusual methanogenic bacterium in coal gasification waste.

    Science.gov (United States)

    Tomei, F A; Rouse, D; Maki, J S; Mitchell, R

    1988-12-01

    Methanogenic bacteria growing on a pilot-scale, anaerobic filter processing coal gasification waste were enriched in a mineral salts medium containing hydrogen and acetate as potential energy sources. Transfer of the enrichments to methanol medium resulted in the initial growth of a strain of Methanosarcina barkeri, but eventually small cocci became dominant. The cocci growing on methanol produced methane and exhibited the typical fluorescence of methanogenic bacteria. They grew in the presence of the cell wall synthesis-inhibiting antibiotics d-cycloserine, fosfomycin, penicillin G, and vancomycin as well as in the presence of kanamycin, an inhibitor of protein synthesis in eubacteria. The optimal growth temperature was 37 degrees C, and the doubling time was 7.5 h. The strain lysed after reaching stationary phase. The bacterium grew poorly with hydrogen as the energy source and failed to grow on acetate. Morphologically, the coccus shared similarities with Methanosarcina sp. Cells were 1 mum wide, exhibited the typical thick cell wall and cross-wall formation, and formed tetrads. Packets and cysts were not formed.

  2. Tracing the run-flip motion of an individual bacterium

    Science.gov (United States)

    Liu, Bin; Morse, Michael; Tang, Jay; Powers, Thomas; Breuer, Kenneth S.

    2012-11-01

    We have developed a digital 3D tracking microscope in which the microscope stage follows the motion of an individual motile microorganism so that the target remains focused at the center of the view-field. The tracking mechanism is achieved by a high-speed feedback control through real-time image analysis and the trace of the microorganism is recorded with submicron accuracy. We apply this tracking microscope to a study of the motion of an individual Caulobacter crescentus, a bacterium that moves up to 100 microns (or 50 body lengths) per second and reverses its direction of motion occasionally by switching the rotation direction of its single helical flagellum. By tracking the motion of a single cell over many seconds, we show how a flip event occurs with submicron resolution and how the speed of a single cell varies over time and with the rotational rate of the flagellum. We also present statistics for the run-reverse dynamics of an ensemble of cells.

  3. Novel Trypanosomatid-Bacterium Association: Evolution of Endosymbiosis in Action

    Directory of Open Access Journals (Sweden)

    Alexei Y. Kostygov

    2016-03-01

    Full Text Available We describe a novel symbiotic association between a kinetoplastid protist, Novymonas esmeraldas gen. nov., sp. nov., and an intracytoplasmic bacterium, “Candidatus Pandoraea novymonadis” sp. nov., discovered as a result of a broad-scale survey of insect trypanosomatid biodiversity in Ecuador. We characterize this association by describing the morphology of both organisms, as well as their interactions, and by establishing their phylogenetic affinities. Importantly, neither partner is closely related to other known organisms previously implicated in eukaryote-bacterial symbiosis. This symbiotic association seems to be relatively recent, as the host does not exert a stringent control over the number of bacteria harbored in its cytoplasm. We argue that this unique relationship may represent a suitable model for studying the initial stages of establishment of endosymbiosis between a single-cellular eukaryote and a prokaryote. Based on phylogenetic analyses, Novymonas could be considered a proxy for the insect-only ancestor of the dixenous genus Leishmania and shed light on the origin of the two-host life cycle within the subfamily Leishmaniinae.

  4. Electromicrobiology of Dissimilatory Sulfur Reducing Bacterium Desulfuromonas acetexigens

    KAUST Repository

    Bin Bandar, Khaled

    2014-12-01

    Bioelectrochmical systems (BES) are engineered electrochemical devices that harness hidden chemical energy of the wastewater in to the form of electricity or hydrogen. Unique microbial communities enrich in these systems for oxidation of organic matter as well as transfer of resulted electron to anode, known them as “electricigens” communities. Exploring novel electricigenesis microbial communities in the nature and understanding their electromicrobiology is one the important aspect for BES systems scale up. Herein, we report first time the electricigenesis property of an anaerobic, fresh water sediment, sulfur reducing bacterium Desulfuromona acetexigens. The electrochemical behavior of D. acetexigens biofilms grown on graphite-rod electrodes in batch-fed mode under an applied potential was investigated with traditional electroanalytical tools, and correlate the electron transfer from biofilms to electrode with a model electricigen Geobacter sulfurreducens electrochemical behavior. Research findings suggest that D. acetexigens has the ability to use electrode as electron acceptor in BES systems through establishing the direct contact with anode by expressing the membrane bound redox proteins, but not due to the secretion of soluble redox mediators. Preliminary results revealed that D. acetexigens express three distinct redox proteins in their membranes for turnover of the electrons from biofilm to electrode, and the 4 whole electricigenesis process observed to be unique in the D. acetexigens compared to that of well-studied model organism G. sulfurreducens.

  5. Denitrification characteristics of a marine origin psychrophilic aerobic denitrifying bacterium

    Institute of Scientific and Technical Information of China (English)

    Haiyan Zheng; Ying Liu; Guangdong Sun; Xiyan Gao; Qingling Zhang; Zhipei Liu

    2011-01-01

    A psychrophilic aerobic denitrifying bacterium,strain S1-1,was isolated from a biological aerated filter conducted for treatment of recirculating water in a marine aquaculture system.Strain S1-1 was preliminarily identified as Psychrobacter sp.based on the analysis of its 16S rRNA gene sequence,which showed 100% sequence similarity to that of Psychrobacter sp.TSBY-70.Strain S 1-1 grew well either in high nitrate or high nitrite conditions with a removal of 100% nitrate or 63.50% nitrite,and the total nitrogen removal rates could reach to 46.48% and 31.89%,respectively.The results indicated that nitrate was mainly reduced in its logarithmic growth phase with a very low leve 1 accumulation of nitrite,suggesting that the aerobic denitrification process of strain S l-1 occurred mainly in this phase.The GC-MS results showed that N2O was formed as the major intermediate during the aerobic denitrifying process of strain S1-1.Finally,factors affecting the growth of strain Sl-1 and its aerobic denitrifying ability were also investigated.Results showed that the optimum aerobic denitrification conditions for strain S1-1 were sodium succinate as carbon source,C/N ratio15,salinity 10 g/L NaCl,incubation temperature 20℃ and initial pH 6.5.

  6. Pandoraea sp. RB-44, A Novel Quorum Sensing Soil Bacterium

    Directory of Open Access Journals (Sweden)

    Robson Ee Han-Jen

    2013-10-01

    Full Text Available Proteobacteria are known to communicate via signaling molecules and this process is known as quorum sensing. The most commonly studied quorum sensing molecules are N-acylhomoserine lactones (AHLs that consists of a homoserine lactone moiety and an N-acyl side chain with various chain lengths and degrees of saturation at the C-3 position. We have isolated a bacterium, RB-44, from a site which was formally a landfill dumping ground. Using matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF mass spectrometry analysis, this isolate was identified as a Pandoraea sp.which was then screened for AHL production using biosensors which indicated its quorum sensing properties. To identify the AHL profile of Pandoraea sp. RB-44, we used high resolution tandem mass spectrometry confirming that this isolate produced N-octanoylhomoserine lactone (C8-HSL. To the best of our knowledge, this is the first report that showed quorum sensing activity exhibited by Pandoraea sp. Our data add Pandoraea sp. to the growing number of bacteria that possess QS systems.

  7. IN SITU RT-PCR WITH A SULFATE-REDUCING BACTERIUM ISOLATED FROM SEAGRASS ROOTS

    Science.gov (United States)

    Bacteria considered to be obligate anaerobes internally colonize roots of the submerged macrophyte Halodule wrightii. A sulfate reducing bacterium, Summer lac 1, was isolated on lactate from H. wrightii roots. The isolate has physiological characteristics typical of Desulfovibri...

  8. Effect of alginic acid decomposing bacterium on the growth of Laminaria japonica (Phaeophyceae)

    Institute of Scientific and Technical Information of China (English)

    WANG You; TANG Xue-xi; YANG Zhen; YU Zhi-ming

    2006-01-01

    We collected the diseased blades of Laminaria japonica from Yantai Sea Farm from October to December 2002, and the alginic acid decomposing bacterium on the diseased blade was isolated and purified, and was identified as Alteromonas espejiana. This bacterium was applied as the causative pathogen to infect the blades of L. japonica under laboratory conditions. The aim of the present study was to identify the effects of the bacterium on the growth of L. japonica, and to find the possibly effective mechanism. Results showed that: (1)The blades of L.japonica exhibited symptoms of lesion,bleaching and deterioration when infected by the bacterium,and their growth and photosynthesis were dramatically suppressed. At the same time, the reactive oxygen species (ROS) generation enhanced obviously, and the relative membrane permeability increased significantly. The contents of malonaldehyde (MDA) and free fatty acid in the microsomol membrane greatly elevated, but the phospholipid content decreased. Result suggested an obvious peroxidation and deesterrification in the blades of L. japonica when infected by the bacterium. (2) The simultaneous assay on the antioxidant enzyme activities demonstrated that superoxide dismutase (SOD) and catalase (CAT) increased greatly when infected by the bacterium, but glutathione peroxidase (Gpx) and ascorbate peroxidase (APX) did not exhibit active responses to the bacterium throughout the experiment. (3) The histomorphological observations gave a distinctive evidence of the severity of the lesions as well as the relative abundance in the bacterial population on the blades after infection. The bacterium firstly invaded into the endodermis of L. japonica and gathered around there, and then resulted in the membrane damage, cells corruption and ultimately, the death of L.japonica.

  9. Endohyphal bacterium enhances production of indole-3-acetic acid by a foliar fungal endophyte.

    Science.gov (United States)

    Hoffman, Michele T; Gunatilaka, Malkanthi K; Wijeratne, Kithsiri; Gunatilaka, Leslie; Arnold, A Elizabeth

    2013-01-01

    Numerous plant pathogens, rhizosphere symbionts, and endophytic bacteria and yeasts produce the important phytohormone indole-3-acetic acid (IAA), often with profound effects on host plants. However, to date IAA production has not been documented among foliar endophytes -- the diverse guild of primarily filamentous Ascomycota that live within healthy, above-ground tissues of all plant species studied thus far. Recently bacteria that live within hyphae of endophytes (endohyphal bacteria) have been detected, but their effects have not been studied previously. Here we show not only that IAA is produced in vitro by a foliar endophyte (here identified as Pestalotiopsis aff. neglecta, Xylariales), but that IAA production is enhanced significantly when the endophyte hosts an endohyphal bacterium (here identified as Luteibacter sp., Xanthomonadales). Both the endophyte and the endophyte/bacterium complex appear to rely on an L-tryptophan dependent pathway for IAA synthesis. The bacterium can be isolated from the fungus when the symbiotic complex is cultivated at 36°C. In pure culture the bacterium does not produce IAA. Culture filtrate from the endophyte-bacterium complex significantly enhances growth of tomato in vitro relative to controls and to filtrate from the endophyte alone. Together these results speak to a facultative symbiosis between an endophyte and endohyphal bacterium that strongly influences IAA production, providing a new framework in which to explore endophyte-plant interactions.

  10. Metabolic evolution of a deep-branching hyperthermophilic chemoautotrophic bacterium.

    Directory of Open Access Journals (Sweden)

    Rogier Braakman

    Full Text Available Aquifex aeolicus is a deep-branching hyperthermophilic chemoautotrophic bacterium restricted to hydrothermal vents and hot springs. These characteristics make it an excellent model system for studying the early evolution of metabolism. Here we present the whole-genome metabolic network of this organism and examine in detail the driving forces that have shaped it. We make extensive use of phylometabolic analysis, a method we recently introduced that generates trees of metabolic phenotypes by integrating phylogenetic and metabolic constraints. We reconstruct the evolution of a range of metabolic sub-systems, including the reductive citric acid (rTCA cycle, as well as the biosynthesis and functional roles of several amino acids and cofactors. We show that A. aeolicus uses the reconstructed ancestral pathways within many of these sub-systems, and highlight how the evolutionary interconnections between sub-systems facilitated several key innovations. Our analyses further highlight three general classes of driving forces in metabolic evolution. One is the duplication and divergence of genes for enzymes as these progress from lower to higher substrate specificity, improving the kinetics of certain sub-systems. A second is the kinetic optimization of established pathways through fusion of enzymes, or their organization into larger complexes. The third is the minimization of the ATP unit cost to synthesize biomass, improving thermodynamic efficiency. Quantifying the distribution of these classes of innovations across metabolic sub-systems and across the tree of life will allow us to assess how a tradeoff between maximizing growth rate and growth efficiency has shaped the long-term metabolic evolution of the biosphere.

  11. Phenotypic variation in the plant pathogenic bacterium Acidovorax citrulli.

    Directory of Open Access Journals (Sweden)

    Ram Kumar Shrestha

    Full Text Available Acidovorax citrulli causes bacterial fruit blotch (BFB of cucurbits, a disease that threatens the cucurbit industry worldwide. Despite the economic importance of BFB, little is known about pathogenicity and fitness strategies of the bacterium. We have observed the phenomenon of phenotypic variation in A. citrulli. Here we report the characterization of phenotypic variants (PVs of two strains, M6 and 7a1, isolated from melon and watermelon, respectively. Phenotypic variation was observed following growth in rich medium, as well as upon isolation of bacteria from inoculated plants or exposure to several stresses, including heat, salt and acidic conditions. When grown on nutrient agar, all PV colonies possessed a translucent appearance, in contrast to parental strain colonies that were opaque. After 72 h, PV colonies were bigger than parental colonies, and had a fuzzy appearance relative to parental strain colonies that are relatively smooth. A. citrulli colonies are generally surrounded by haloes detectable by the naked eye. These haloes are formed by type IV pilus (T4P-mediated twitching motility that occurs at the edge of the colony. No twitching haloes could be detected around colonies of both M6 and 7a1 PVs, and microscopy observations confirmed that indeed the PVs did not perform twitching motility. In agreement with these results, transmission electron microscopy revealed that M6 and 7a1 PVs do not produce T4P under tested conditions. PVs also differed from their parental strain in swimming motility and biofilm formation, and interestingly, all assessed variants were less virulent than their corresponding parental strains in seed transmission assays. Slight alterations could be detected in some DNA fingerprinting profiles of 7a1 variants relative to the parental strain, while no differences at all could be seen among M6 variants and parental strain, suggesting that, at least in the latter, phenotypic variation is mediated by slight genetic

  12. Corrosion Behavior of Steel A3 Influenced by Thiobacillus Thiooxidans%A3钢在氧化硫硫杆菌作用下的腐蚀行为

    Institute of Scientific and Technical Information of China (English)

    李松梅; 杜娟; 刘建华; 于美

    2009-01-01

    Surface analysis method, mass loss method, and electrochemical test were employed to investigate the corrosion behavior of steel A3 under the effect of Thiobacillus thiooxidans (T.t). Scanning electronic microscopy (SEM) results indicated that the presence of T.t resulted in a more compact biofilm and product film. Pitting occurred on the steel A3 coupon immersed into a sterile system while the one in the T.t system showed general corrosion. The average corrosion rate in the sterile system was greater than that in the T.t system after 3 weeks. Electrochemical impedance spectroscopy (EIS) showed that there were only two time constants for the sample immersed in the T.t system after 10 days. This demonstrates that a compact and strongly inserted product film was formed on the surface of coupon in the presence of T.t which effectively obstructed the erosion of caustic ions. Polarization curve results showed that the corrosion current density of the metal decreased after 20 days of exposure to the T. t solution.%采用表面分析技术、失重法和电化学测试研究了A3钢在氧化硫硫杆菌(T.t)作用下的腐蚀行为.扫描电子显微镜(SEM)分析结果表明,与无菌体系相比,氧化硫硫杆菌会在A3钢表面形成敛密的生物膜和腐蚀产物膜.去除膜层后,无菌体系中的试样出现点蚀,氧化硫硫杆菌体系中试样呈现为均匀腐蚀.浸泡三周后,氧化硫硫杆菌体系中A3钢的腐蚀失重远小于无菌体系.电化学交流阻抗谱(EIS)测试结果显示,在浸泡10 d后,氧化硫硫杆菌中的电极表面只存在两个时间常数,这表明氧化硫硫杆菌会在试样表面形成致密且附着力非常强的产物膜层,有效地阻碍了腐蚀介质对基体的侵蚀.极化曲线结果表明,浸泡20 d后,氧化硫硫杆菌的存在使得金属具有较小的自腐蚀电流密度.

  13. Characterization of an Endophytic Bacterium G062 Isolate with Beneficial Traits

    Directory of Open Access Journals (Sweden)

    ALINA AKHDIYA

    2014-12-01

    Full Text Available An endophytic bacterium isolate G062 was characterized base on its molecular genetic potents, morphology, physiology, and biochemistry reactions. Analysis of 16S rDNA sequences of G062 showed the highest similarity to Paracoccus halophilus (98%. Detection of the phlD and prnC genes occurrence indicated that the bacterium had this antibiotic-like genes of Diacethylphloroglucinol (DAPG and pyrrolnitrin. The cells are rod shaped (0.59-0.89 x 1.85-3.3 µm, aerobic, Gram negative, non motile, non spore forming, positive catalase, positive oxydase, could reduce NO3 to N2, nitrogen fixing, producing siderophore and plant growth hormones-like compounds (IAA, Gibberellin, and zeatin, and solubilizing phosphate. The G062 isolate could grow on media containing 2.5% NaCl. Range of the temperature and pH growth were 15-40 and 5.0-9.5 oC, respectively. The bacterium did not cause red blood cells lysis. There was no hypersensitive response when it was injected into tobacco leaves, and it was not pathogenic against potato plantlets. Moreover, the bacterium promoted the growth of the potato plant and had high colonization ability. These results suggested that the bacterium had beneficial and good traits as biological agent candidate to promote potato plant growth.

  14. The atherogenic bacterium Porphyromonas gingivalis evades circulating phagocytes by adhering to erythrocytes

    DEFF Research Database (Denmark)

    Belstrøm, Daniel; Holmstrup, Palle; Damgaard, Christian

    2011-01-01

    A relationship between periodontitis and coronary heart disease has been investigated intensively. A pathogenic role for the oral bacterium Porphyromonas gingivalis has been suggested for both diseases. We examined whether complement activation by P. gingivalis strain ATCC 33277 allows the bacter......A relationship between periodontitis and coronary heart disease has been investigated intensively. A pathogenic role for the oral bacterium Porphyromonas gingivalis has been suggested for both diseases. We examined whether complement activation by P. gingivalis strain ATCC 33277 allows...... the bacterium to adhere to human red blood cells (RBCs) and thereby evade attack by circulating phagocytes. On incubation with normal human serum, the P. gingivalis strain efficiently fixed complement component 3 (C3). Incubation of bacteria with washed whole blood cells suspended in autologous serum resulted....... gingivalis exploits RBCs as a transport vehicle, rendering it inaccessible to attack by phagocytes, and by doing so plays a role in the development of systemic diseases....

  15. Action of the Selenomorpholine Compounds on the Bacterium Growth by Microcalorimetry

    Institute of Scientific and Technical Information of China (English)

    李曦; 刘义; 等

    2002-01-01

    The action of β-(N-selenomorpholine) ethyl phenyl ketone hydrochloride and 4-(N-selenomorpholine)-2-butanone hydro-chloride on Escherichia coli and Staphylococcus aureus was studied by microcalorimetry,Differences in their capacities to affect the metabolism of this bacterium were observed.The kinetics shows that the selenomorpholine compounds had action on the metabolism process of Escherichia coli and Staphylococcus aureus.The rate constant (k) of the studied bacterium in the presence of the drugs are concentration-dependant.The growth rate constants decrease with an increase in the mass of the selenomorpholine compounds ,but their relationship is different.As deduced from the rate constant(k) of the studied bacterium(in log phase )and the half inhibitory concentration (IC50),the experimental results reveal that the studied selenomorpholine compounds all have good antibiotic activity and better antibacterial activity on Staphylcoccus aureus than on Escherichia coli.

  16. Action of the Selenomorpholine Compounds on the Bacterium Growth by Microcalorimetry

    Institute of Scientific and Technical Information of China (English)

    LI,Xi(李曦); LIU,Yi(刘义); WU,Jun(吴军); QU,Song-Sheng(屈松生)

    2002-01-01

    The action of β-(N-selenomorpholine) ethyl phenyl ketone hy drochloride and 4-(N-selenomorpholine)-2-butanone hydrochloride on Escherichia coli and Staphylococcus aureus was studied by microcalorimetry. Differences in their capacities to affect the metabolism of this bacterium were observed. The kinetics shows that the selenomorphline compounds had action on the metabolism process of Escherichia coli and Staphylococcus aureus. The rate constant (k) of the studied bacterium in the presence of the drugs are concentration-dependant. The growth rate constants decrease with an increase in the mass of the selenomorpholine compounds, but their relationship is different. As deduced from the rate constant (k) of the studied bacterium (in log phase) and the half inhibitory concentration (IC50), the experimental results reveal that the studied selenomorphline compounds all have good antibiotic activity and better antibacterial activity on Staphylococcus aureus than on Escherichia coli.

  17. Complete Genome Sequence of a thermotolerant sporogenic lactic acid bacterium, Bacillus coagulans strain 36D1

    Energy Technology Data Exchange (ETDEWEB)

    Rhee, Mun Su [University of Florida, Gainesville; Moritz, Brelan E. [University of Florida, Gainesville; Xie, Gary [Los Alamos National Laboratory (LANL); Glavina Del Rio, Tijana [U.S. Department of Energy, Joint Genome Institute; Dalin, Eileen [U.S. Department of Energy, Joint Genome Institute; Tice, Hope [U.S. Department of Energy, Joint Genome Institute; Bruce, David [Los Alamos National Laboratory (LANL); Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Chertkov, Olga [Los Alamos National Laboratory (LANL); Brettin, Thomas S [ORNL; Han, Cliff [Los Alamos National Laboratory (LANL); Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Patel, Milind [University of Florida, Gainesville; Ou, Mark [University of Florida, Gainesville; Harbrucker, Roberta [University of Florida, Gainesville; Ingram, Lonnie O. [University of Florida; Shanmugam, Keelnathan T. [University of Florida

    2011-01-01

    Bacillus coagulans is a ubiquitous soil bacterium that grows at 50-55 C and pH 5.0 and fer- ments various sugars that constitute plant biomass to L (+)-lactic acid. The ability of this spo- rogenic lactic acid bacterium to grow at 50-55 C and pH 5.0 makes this organism an attrac- tive microbial biocatalyst for production of optically pure lactic acid at industrial scale not only from glucose derived from cellulose but also from xylose, a major constituent of hemi- cellulose. This bacterium is also considered as a potential probiotic. Complete genome se- quence of a representative strain, B. coagulans strain 36D1, is presented and discussed.

  18. Complete Genome Sequence of a thermotolerant sporogenic lactic acid bacterium, Bacillus coagulans strain 36D1

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Gary [Los Alamos National Laboratory (LANL); Dalin, Eileen [U.S. Department of Energy, Joint Genome Institute; Tice, Hope [U.S. Department of Energy, Joint Genome Institute; Chertkov, Olga [Los Alamos National Laboratory (LANL); Land, Miriam L [ORNL

    2011-01-01

    Bacillus coagulans is a ubiquitous soil bacterium that grows at 50-55 C and pH 5.0 and fer-ments various sugars that constitute plant biomass to L (+)-lactic acid. The ability of this sporogenic lactic acid bacterium to grow at 50-55 C and pH 5.0 makes this organism an attractive microbial biocatalyst for production of optically pure lactic acid at industrial scale not only from glucose derived from cellulose but also from xylose, a major constituent of hemi-cellulose. This bacterium is also considered as a potential probiotic. Complete genome squence of a representative strain, B. coagulans strain 36D1, is presented and discussed.

  19. Atopobacter phocae gen. nov., sp. nov., a novel bacterium isolated from common seals.

    Science.gov (United States)

    Lawson, P A; Foster, G; Falsen, E; Ohlén, M; Collins, M D

    2000-09-01

    Two strains of a Gram-positive, catalase-negative, facultatively anaerobic, rod-shaped bacterium isolated from common seals were characterized using phenotypic and molecular taxonomic methods. The two strains closely resembled each other based on their biochemical characteristics, and PAGE analysis of whole-cell protein patterns confirmed their close phenotypic affinity. 16S rRNA gene sequencing showed that the two strains were genetically highly related (99.8% sequence similarity) and that they constitute a new line of descent within the lactic acid group of bacteria. The nearest phylogenetic neighbours of the unknown bacterium were Granulicatella spp., with related taxa such as enterococci, carnobacteria, Desemzia incerta, Lactosphaera pasteurii, Melissococcus plutonius, tetragenococci and vagococci more distantly related. Based on phylogenetic and phenotypic evidence it is proposed that the unknown bacterium from seals be classified in a new genus as Atopobacter phocae gen. nov., sp. nov. The type strain of Atopobacter phocae is CCUG 42358T (= CIP 106392T).

  20. Studies on the pathogenic bacterium of ulcer disease in Epinephelus awoara

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Studies were conducted to determine the cause of the acute mortality of cage-cultured Epinephelus awoara in the Tong'an Bay of Xiamen, China during the summer of 2002. Predominant bacteria strain TS-628 was isolated from the diseased grouper. The virulence test confirmed that TS-628 was the pathogenic bacterium. Biochemical characteristics of the isolates were determined using the automatic bacterial identification system and standard tube tests. To further confirm the identification, a 1 121 bp 16S rRNA gene sequence of the isolate was amplified by PCR, which had been deposited into Genbank (accession number: AY747308). According to the biochemical characteristics and by comparing the 16S rRNA gene homology of the isolate, the pathogenic bacterium was identified as Vibrio harveyi. Drug sensitivity tests showed that this pathogenic bacterium was sensitive to 16 antibacterials, especially to chloramphenicol and actinospectacin, but completely resistant to antibacterials likes vancomycin, penicillin, lincomycin, and so on.

  1. Phosphate enhances levan production in the endophytic bacterium Gluconacetobacter diazotrophicus Pal5.

    Science.gov (United States)

    Idogawa, Nao; Amamoto, Ryuta; Murata, Kousaku; Kawai, Shigeyuki

    2014-01-01

    Gluconacetobacter diazotrophicus is a gram-negative and endophytic nitrogen-fixing bacterium that has several beneficial effects in host plants; thus, utilization of this bacterium as a biofertilizer in agriculture may be possible. G. diazotrophicus synthesizes levan, a D-fructofuranosyl polymer with β-(2→6) linkages, as an exopolysaccharide and the synthesized levan improves the stress tolerance of the bacterium. In this study, we found that phosphate enhances levan production by G. diazotrophicus Pal5, a wild type strain that showed a stronger mucous phenotype on solid medium containing 28 mM phosphate than on solid medium containing 7 mM phosphate. A G. diazotrophicus Pal5 levansucrase disruptant showed only a weak mucous phenotype regardless of the phosphate concentration, indicating that the mucous phenotype observed on 28 mM phosphate medium was caused by levan. To our knowledge, this is the first report of the effect of a high concentration of phosphate on exopolysaccharide production.

  2. Biosorption of Cu by Thiobacillus ferrooxidans

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Manriquez, A. [Departamento de Ingenieria Quimica y Metalurgia, Universidad de Sonora, Hermosillo (Mexico); Magana, P.I. [Departamento de Biotecnologia y Bioingenieria, Centro de Investigacion y Estudios Avanzados (Mexico); Lopez, V. [Departamento de Biotecnologia y Bioingenieria, Centro de Investigacion y Estudios Avanzados (Mexico); Guzman, R. [Department of Chemical and Environmental Engineering, University of Arizona, Tucson (United States)

    1998-02-01

    Current technologies for removal and recovery of both toxic and industrial interest metals usually produce wastes with high concentrations of those substances. They are an important source of environmental pollution, specially when they contain heavy metals. This is one of the most important environmental problems, and of the most difficult to solve. So far, there have been a number of studies considering the possibility of removing and recovering heavy metals from diluted solutions. These are due, principally, because of the commercial value of some metals as well as the environmental impact caused by them. The traditional methods for removing have several disadvantages when metals are present in concentrations lower than 100 mg/l. Biosorption, which uses biological materials as adsorbents, has been considered as an alternative method. In this work, several variables that affect the capacity for copper biosorption by T. ferrooxidans have been studied. Particularly, the effect of pH, chemical pretreatment, biomass concentration and temperature have been considered. Results indicate that a capacity as high as 119 mg of Cu/g of dry biomass can be obtained at a temperature of 25 C. (orig.) With 6 figs., 1 tab., 13 refs.

  3. Expression of the Bacillus thuringiensis mosquitocidal toxin Cry11Aa in the aquatic bacterium Asticcacaulis excentricus.

    Science.gov (United States)

    Armengol, Gemma; Guevara, Oscar Enrique; Orduz, Sergio; Crickmore, Neil

    2005-12-01

    A mosquitocidal aquatic bacterium has been developed by introducing an operon containing the cry11Aa, and p20 genes from Bacillus thuringiensis subsp. israelensis (Bti) into the gram-negative aquatic bacterium Asticcacaulis excentricus. After transformation, the cry11Aa gene was successfully expressed in recombinant A. excentricus under the tac promoter, at the level of 0.04 pg/cell. The recombinant bacteria were toxic to Aedes aegypti larvae with an LC(50) of 6.83 x 10(5) cells/mL. We believe that these bacteria may have potential as genetically engineered microorganisms for the control of mosquito larvae.

  4. Isolation and characterization of Caldicellulosiruptor lactoaceticus sp. nov., an extremely thermophilic, cellulolytic, anaerobic bacterium

    DEFF Research Database (Denmark)

    Mladenovska, Zuzana; Mathrani, Indra M.; Ahring, Birgitte Kiær

    1995-01-01

    activity. The G + C content of the cellular DNA of strain 6A was 35.2 +/- 0.8 mol%. Complete 16S rDNA sequence analysis showed that strain 6A was phylogenetically related to Caldicellulosiruptor saccharolyticus. It is proposed that the isolated bacterium be named Caldicellulosiruptor lactoaceticus sp. nov....... and ethanol occurred as minor fermentation products. Only a restricted number of carbon sources (cellulose, xylan, starch, pectin, cellobiose, xylose, maltose and lactose) were used as substrates. During growth on Avicel, the bacterium produced free cellulases with carboxymethylcellulase and avicelase...

  5. Draft Genome Sequence of an Anaerobic and Extremophilic Bacterium, Caldanaerobacter yonseiensis, Isolated from a Geothermal Hot Stream

    OpenAIRE

    2013-01-01

    Caldanaerobacter yonseiensis is a strictly anaerobic, thermophilic, spore-forming bacterium, which was isolated from a geothermal hot stream in Indonesia. This bacterium utilizes xylose and produces a variety of proteases. Here, we report the draft genome sequence of C. yonseiensis, which reveals insights into the pentose phosphate pathway and protein degradation metabolism in thermophilic microorganisms.

  6. Isolation from the Sorghum bicolor Mycorrhizosphere of a Bacterium Compatible with Arbuscular Mycorrhiza Development and Antagonistic towards Soilborne Fungal Pathogens

    Science.gov (United States)

    Budi, S. W.; van Tuinen, D.; Martinotti, G.; Gianinazzi, S.

    1999-01-01

    A gram-positive bacterium with antagonistic activity towards soilborne fungal pathogens has been isolated from the mycorrhizosphere of Sorghum bicolor inoculated with Glomus mosseae. It has been identified as Paenibacillus sp. strain B2 based on its analytical profile index and on 16S ribosomal DNA analysis. Besides having antagonistic activity, this bacterium stimulates mycorrhization. PMID:10543835

  7. Draft Genome Sequence of Bacillus licheniformis Strain GB2, a Hydrocarbon-Degrading and Plant Growth-Promoting Soil Bacterium.

    Science.gov (United States)

    Gkorezis, Panagiotis; Van Hamme, Jonathan; Bottos, Eric; Thijs, Sofie; Balseiro-Romero, Maria; Monterroso, Carmela; Kidd, Petra Suzan; Rineau, Francois; Weyens, Nele; Sillen, Wouter; Vangronsveld, Jaco

    2016-06-23

    We report the 4.39 Mb draft genome of Bacillus licheniformis GB2, a hydrocarbonoclastic Gram-positive bacterium of the family Bacillaceae, isolated from diesel-contaminated soil at the Ford Motor Company site in Genk, Belgium. Strain GB2 is an effective plant-growth promoter useful for diesel fuel remediation applications based on plant-bacterium associations.

  8. Isolation of Achromobacter xylosoxidans subsp. denitrificans and it's degradation of phenanthrene%木糖氧化无色杆菌反硝化亚种细菌的分离鉴定及其菲降解特性研究

    Institute of Scientific and Technical Information of China (English)

    武凤霞; 范丙全; 刘建玲

    2007-01-01

    利用选择性富集培养及升华法,从石油污染的土壤中分离到2株菲降解细菌,它们在以菲为唯一碳源的培养基上生长良好.应用B10LOG细菌鉴定系统和分子生物学方法对两株细菌进行鉴定,两株菌分别为坚强芽孢杆菌(Bacillus firmus)和木糖氧化无色杆菌反硝化亚种(Achromobacter xylosoxidans subsp.denitrificans),两株菌均具有邻苯二酚氧化酶活性.两株细菌在液体培养条件下都表现较强降解菲的能力,液体培养60 h约90%的加入菲被降解.通过测定液体培养基中菲浓度和菌体密度变化发现,菌株降解菲的量与其生长密度相关;随着菌体浓度(吸光度)的增加,代谢底物菲的浓度明显降低,两株菌混合使用能够大幅度提高降解菲的能力.

  9. Complete genome sequence of the xylan-degrading subseafloor bacterium Microcella alkaliphila JAM-AC0309.

    Science.gov (United States)

    Kurata, Atsushi; Hirose, Yuu; Misawa, Naomi; Wakazuki, Sachiko; Kishimoto, Noriaki; Kobayashi, Tohru

    2016-03-10

    Here we report the complete genome sequence of Microcella alkaliphila JAM-AC0309, which was newly isolated from the deep subseafloor core sediment from offshore of the Shimokita Peninsula of Japan. An array of genes related to utilization of xylan in this bacterium was identified by whole genome analysis.

  10. Comment on "A bacterium that degrades and assimilates poly(ethylene terephthalate)".

    Science.gov (United States)

    Yang, Yu; Yang, Jun; Jiang, Lei

    2016-08-19

    Yoshida et al (Report, 11 March 2016, p. 1196) reported that the bacterium Ideonella sakaiensis 201-F6 can degrade and assimilate poly(ethylene terephthalate) (PET). However, the authors exaggerated degradation efficiency using a low-crystallinity PET and presented no straightforward experiments to verify depolymerization and assimilation of PET. Thus, the authors' conclusions are rather misleading.

  11. Isolation and algae-lysing characteristics of the algicidal bacterium B5

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Water blooms have become a worldwide environmental problem. Recently, algicidal bacteria have attracted wide attention as possible agents for inhibiting algal water blooms. In this study, one strain of algicidal bacterium B5 was isolated from activated sludge. On the basis of analysis of its physiological characteristics and 16S rDNA gene sequence, it was identified as Bacillus fusiformis. Its algae-lysing characteristics on Microcystis aeruginosa, Chlorella and Scenedesmus were tested. The results showed that: (1) the algicidal bacterium B5 is a Gram-negative bacterium. The 16S rDNA nucleotide sequence homology of strain B5 with 2 strains of B. fusiformis reached 99.86%, so B5 was identified as B. fusiformis; (2) the algal-lysing effects of the algicidal bacterium B5 on M. aeruginosa, Chlorella and Scenedesmus were pronounced. The initial bacterial and algal cell densities strongly influence the removal rates of chlorophyll-a. The greater the initial bacterial cell density, the faster the degradation of chlorophyll-a. The greater the initial algal cell density, the slower the degradation of chlorophyll-a. When the bacterial cell density was 3.6 × 107 cells/ml, nearly 90% of chlorophyll-a was removed. When the chlorophyll-a concentration was less than 550 μg/L, about 70 % was removed; (3) the strain B5 lysed algae not directly but by secreting metabolites and these metabolites could bear heat treatment.

  12. Inactivation of Glutamine Synthetase by Ammonia Shock in the Gram-Positive Bacterium Streptomyces cattleya

    OpenAIRE

    Wax, Richard; Synder, Linda; Kaplan, Louis

    1982-01-01

    In cultures of the gram-positive bacterium Streptomyces cattleya, a rapid inactivation of glutamine synthetase was seen after ammonia shock. pH activity curves for ammonia-shocked and control cultures are shown. A peak of glutamine synthetase activity was seen during fermentation for production of the antibiotic thienamycin.

  13. Draft Genome Sequence of Desulfuromonas acetexigens Strain 2873, a Novel Anode-Respiring Bacterium

    KAUST Repository

    Katuri, Krishna

    2017-03-03

    Here, we report the draft genome sequence of Desulfuromonas acetexigens strain 2873, which was originally isolated from digester sludge from a sewage treatment plant in Germany. This bacterium is capable of anode respiration with high electrochemical activity in microbial electrochemical systems. The draft genome contains 3,376 predicted protein-coding genes and putative multiheme c-type cytochromes.

  14. Modeling of Cd Uptake and Efflux Kinetics in Metal-Resistant Bacterium Cupriavidus metallidurans

    NARCIS (Netherlands)

    Hajdu, R.; Pinheiro, J.P.; Galceran, J.; Slaveykova, V.I.

    2010-01-01

    The Model of Uptake with Instantaneous Adsorption and Efflux, MUIAE, describing and predicting the overall Cd uptake by the metal-resistant bacterium Cupriavidus metallidurans CH34, is presented. MUIAE takes into account different processes at the bacteria-medium interface with specific emphasis on

  15. Photobacterium marinum sp. nov., a marine bacterium isolated from a sediment sample from Palk Bay, India

    Digital Repository Service at National Institute of Oceanography (India)

    Srinivas, T.N.R.; VijayaBhaskar, Y.; Bhumika, V.; AnilKumar, P.

    histaminum sp. nov., a histamine-producing marine bacterium. Int. J. Syst. Bacteriol. 44, 631-636. [20] Ostle, A.G., Holt, J.G. (1982) Nile blue A as fluorescent stain for poly-b-hydroxybutyrate. Appl. Environ. Microbiol. 44, 238-241. [21] Park, Y...

  16. Fluoroacetate biosynthesis from the marine-derived bacterium Streptomyces xinghaiensis NRRL B-24674.

    Science.gov (United States)

    Huang, Sheng; Ma, Long; Tong, Ming Him; Yu, Yi; O'Hagan, David; Deng, Hai

    2014-07-21

    Genome sequencing identified a fluorinase gene in the marine bacterium Streptomyces xinghaiensis NRRL B-24674. Fermentation of the organism with inorganic fluoride (2 mM) demonstrated that the organism could biosynthesise fluoroacetate and that fluoroacetate production is sea-salt dependent. This is the first fluorometabolite producing microorganism identified from the marine environment.

  17. Biohydrogen Production by the Thermophilic Bacterium Caldicellulosiruptor saccharolyticus: Current Status and Perspectives

    NARCIS (Netherlands)

    Bielen, A.A.M.; Verhaart, M.R.A.; Oost, van der J.; Kengen, S.W.M.

    2013-01-01

    Caldicellulosiruptor saccharolyticus is one of the most thermophilic cellulolytic organisms known to date. This Gram-positive anaerobic bacterium ferments a broad spectrum of mono-, di- and polysaccharides to mainly acetate, CO2 and hydrogen. With hydrogen yields approaching the theoretical limit fo

  18. Genome sequence of the mycorrhizal helper bacterium Pseudomonas fluorescens BBc6R8

    Energy Technology Data Exchange (ETDEWEB)

    Deveau, Aurelie [French National Insitute for Agricultural Research (INRA); Grob, Harald [University of Bonn, Germany; Morin, Emmanuelle [INRA, Nancy, France; Karpinets, Tatiana V [ORNL; Utturkar, Sagar M [ORNL; Mehnaz, Samina [University of the Punjab, Pakistan; Kurz, Sven [University of Bonn, Germany; Martin, Francis [INRA, Nancy, France; Frey-Klett, Pascale [INRA, Nancy, France; Labbe, Jessy L [ORNL

    2014-01-01

    We report the draft genome sequence of the mycorrhiza helper bacterium Pseudomonas fluorescens strain BBc6R8 . Several traits which could be involved in the mycorrhiza helper ability of the bacterial strain such as multiple secretion systems, auxin metabolism and phosphate mobilization were evidenced in the genome.

  19. Robinsoniella peoriensis: A model anaerobic commensal bacterium for acquisition of antibiotic resistance?

    Science.gov (United States)

    Background: R. peoriensis was characterized in our laboratories from swine manure and feces as a Gram-positive, anaerobic bacterium. Since then strains of this species have been identified from a variety of mammalian and other gastrointestinal (GI) tracts, suggesting it is a member of the commensal ...

  20. Flavobacterium nitratireducens sp. nov., an amylolytic bacterium of the family Flavobacteriaceae isolated from coastal surface seawater

    Digital Repository Service at National Institute of Oceanography (India)

    Nupur; Bhumika, V.; Srinivas, T.N.R.; AnilKumar, P.

    A novel Gram-negative, rod-shaped, non-motile bacterium, designated strain N1 sup(T), was isolated from a marine water sample collected from the sea shore, Bay of Bengal, Visakhapatnam, India. The strain was positive for starch hydrolysis, nitrate...

  1. Marinilabilia nitratireducens sp. nov., a lipolytic bacterium of the family Marinilabiliaceae isolated from marine solar saltern

    Digital Repository Service at National Institute of Oceanography (India)

    Shalley, S.; PradipKumar; Srinivas, T.N.R.; Suresh, K.; AnilKumar, P.

    A Gram-negative, rod shaped, motile bacterium, was isolated from a marine solar saltern sample collected from Kakinada, India. Strain AK2 sup(T) was determined to be positive for nitrate reduction, catalase, Ala-Phe-Pro-arylamidase, beta...

  2. Draft Genome Sequence of the Moderately Thermophilic Bacterium Schleiferia thermophila Strain Yellowstone (Bacteroidetes).

    Science.gov (United States)

    Thiel, Vera; Hamilton, Trinity L; Tomsho, Lynn P; Burhans, Richard; Gay, Scott E; Ramaley, Robert F; Schuster, Stephan C; Steinke, Laurey; Bryant, Donald A

    2014-08-28

    The draft genome sequence of the moderately thermophilic bacterium Schleiferia thermophila strain Yellowstone (Bacteroidetes), isolated from Octopus Spring (Yellowstone National Park, WY, USA) was sequenced and comprises 2,617,694 bp in 35 contigs. The draft genome is predicted to encode 2,457 protein coding genes and 37 tRNA encoding genes and two rRNA operons.

  3. Transcriptome analysis of the rhizosphere bacterium Azospirillum brasilense reveals an extensive auxin response.

    Science.gov (United States)

    Van Puyvelde, Sandra; Cloots, Lore; Engelen, Kristof; Das, Frederik; Marchal, Kathleen; Vanderleyden, Jos; Spaepen, Stijn

    2011-05-01

    The rhizosphere bacterium Azospirillum brasilense produces the auxin indole-3-acetic acid (IAA) through the indole-3-pyruvate pathway. As we previously demonstrated that transcription of the indole-3-pyruvate decarboxylase (ipdC) gene is positively regulated by IAA, produced by A. brasilense itself or added exogenously, we performed a microarray analysis to study the overall effects of IAA on the transcriptome of A. brasilense. The transcriptomes of A. brasilense wild-type and the ipdC knockout mutant, both cultured in the absence and presence of exogenously added IAA, were compared.Interfering with the IAA biosynthesis/homeostasis in A. brasilense through inactivation of the ipdC gene or IAA addition results in much broader transcriptional changes than anticipated. Based on the multitude of changes observed by comparing the different transcriptomes, we can conclude that IAA is a signaling molecule in A. brasilense. It appears that the bacterium, when exposed to IAA, adapts itself to the plant rhizosphere, by changing its arsenal of transport proteins and cell surface proteins. A striking example of adaptation to IAA exposure, as happens in the rhizosphere, is the upregulation of a type VI secretion system (T6SS) in the presence of IAA. The T6SS is described as specifically involved in bacterium-eukaryotic host interactions. Additionally, many transcription factors show an altered regulation as well, indicating that the regulatory machinery of the bacterium is changing.

  4. Draft Genome Sequence of a Thermophilic Desulfurization Bacterium, Geobacillus thermoglucosidasius Strain W-2

    Science.gov (United States)

    Zhu, Lin; Li, Mingchang; Guo, Shuyi

    2016-01-01

    Geobacillus thermoglucosidasius strain W-2 is a thermophilic bacterium isolated from a deep-subsurface oil reservoir in northern China, which is capable of degrading organosulfur compounds. Here, we report the draft genome sequence of G. thermoglucosidasius strain W-2, which may help to elucidate the genetic basis of biodegradation of organosulfur pollutants under heated conditions. PMID:27491977

  5. Genome Sequence of the Acetogenic Bacterium Moorella mulderi DSM 14980T

    Science.gov (United States)

    Castillo Villamizar, Genis Andrés

    2016-01-01

    Here, we report the draft genome sequence of Moorella mulderi DSM 14980T, a thermophilic acetogenic bacterium, which is able to grow autotrophically on H2 plus CO2 using the Wood-Ljungdahl pathway. The genome consists of a circular chromosome (2.99 Mb). PMID:27231372

  6. Bacterium induces cryptic meroterpenoid pathway in the pathogenic fungus Aspergillus fumigatus.

    Science.gov (United States)

    König, Claudia C; Scherlach, Kirstin; Schroeckh, Volker; Horn, Fabian; Nietzsche, Sandor; Brakhage, Axel A; Hertweck, Christian

    2013-05-27

    Stimulating encounter: The intimate, physical interaction between the soil-derived bacterium Streptomyces rapamycinicus and the human pathogenic fungus Aspergillus fumigatus led to the activation of an otherwise silent polyketide synthase (PKS) gene cluster coding for an unusual prenylated polyphenol (fumicycline A). The meroterpenoid pathway is regulated by a pathway-specific activator gene as well as by epigenetic factors.

  7. Moritella viscosa, a pathogenic bacterium affecting the fillet quality in fish

    DEFF Research Database (Denmark)

    Ingerslev, Hans-Christian; Nielsen, Michael Engelbrecht

    2011-01-01

    ’ which affects various fish species in seawater during cold periods (Lunder et al. 1995). The bacterium is mainly a problem for farmed salmonid species, such as Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss), but has also been isolated from other fish species, including Atlantic...

  8. 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.

  9. The construction of an engineered bacterium to remove cadmium from wastewater.

    Science.gov (United States)

    Chang, S; Shu, H

    2014-01-01

    The removal of cadmium (Cd) from wastewater before it is released from factories is important for protecting human health. Although some researchers have developed engineered bacteria, the resistance of these engineered bacteria to Cd have not been improved. In this study, two key genes involved in glutathione synthesis (gshA and gshB), a serine acetyltransferase gene (cysE), a Thlaspi caerulescens phytochelatin synthase gene (TcPCS1), and a heavy metal ATPase gene (TcHMA3) were transformed into Escherichia coli BL21. The resistance of the engineered bacterium to Cd was significantly greater than that of the initial bacterium and the Cd accumulation in the engineered bacterium was much higher than in the initial bacterium. In addition, the Cd resistance of the bacteria harboring gshB, gshA, cysE, and TcPCS1 was higher than that of the bacteria harboring gshA, cysE, and TcPCS1. This finding demonstrated that gshB played an important role in glutathione synthesis and that the reaction catalyzed by glutathione synthase was the limiting step for producing phytochelatins. Furthermore, TcPCS1 had a greater specificity and a higher capacity for removing Cd than SpPCS1, and TcHMA3 not only played a role in T. caerulescens but also functioned in E. coli.

  10. Complete genome of Nitrosospira briensis C-128, an ammonia-oxidizing bacterium from agricultural soil

    NARCIS (Netherlands)

    Rice, Marlen C.; Norton, Jeanette M.; Valois, Frederica; Bollmann, Annette; Bottomley, Peter J.; Klotz, Martin G.; Laanbroek, Hendrikus J.; Suwa, Yuichi; Stein, Lisa Y.; Sayavedra-Soto, Luis; Woyke, Tanja; Shapiro, Nicole; Goodwin, Lynne A.; Huntemann, Marcel; Clum, Alicia; Pillay, Manoj; Kyrpides, Nikos; Varghese, Neha; Mikhailova, Natalia; Markowitz, Victor; Palaniappan, Krishna; Ivanova, Natalia; Stamatis, Dimitrios; Reddy, T. B. K.; Ngan, Chew Yee; Daum, Chris

    2016-01-01

    Nitrosospira briensis C-128 is an ammonia-oxidizing bacterium isolated from an acid agricultural soil. N. briensis C-128 was sequenced with PacBio RS technologies at the DOE-Joint Genome Institute through their Community Science Program (2010). The high-quality finished genome contains one chromosom

  11. Marinobacter nitratireducens sp. nov., a halophilic and lipolytic bacterium isolated from coastal surface sea water

    Digital Repository Service at National Institute of Oceanography (India)

    Bhumika, V.; Ravinder, K.; Korpole, S.; Srinivas, T.N.R.; AnilKumar, P.

    A novel Gram-stain-negative, rod-shaped, motile bacterium, designated strain AK21T , was isolated from coastal surface sea water at Visakhapatnam, India. The strain was positive for oxidase, catalase, lipase, L-proline arylamidase...

  12. Draft Genome Sequence of Photorhabdus luminescens subsp. laumondii HP88, an Entomopathogenic Bacterium Isolated from Nematodes

    OpenAIRE

    Ghazal, Shimaa; Oshone, Rediet; Simpson, Stephen,; Morris, Krystalynne; Abebe-Akele, Feseha; Thomas, W. Kelley; Khalil, Kamal M.; Tisa, Louis S.

    2016-01-01

    Photorhabdus luminescens subsp. laumondii HP88 is an entomopathogenic bacterium that forms a symbiotic association with Heterorhabditis nematodes. We report here a 5.27-Mbp draft genome sequence for P. luminescens subsp. laumondii HP88, with a G+C content of 42.4% and containing 4,243 candidate protein-coding genes.

  13. Purification and reconstitution of the glutamate carrier GltT of the thermophilic bacterium Bacillus stearothermophilus

    NARCIS (Netherlands)

    Gaillard, Isabelle; Slotboom, Dirk-Jan; Knol, Jan; Lolkema, Juke S.; Konings, Wil N.

    1996-01-01

    An affinity tag consisting of six adjacent histidine residues followed by an enterokinase cleavage site was genetically engineered at the N-terminus of the glutamate transport protein GltT of the thermophilic bacterium Bacillus stearothermophilus. The fusion protein was expressed in Escherichia coli

  14. Active efflux systems in the solvent-tolerant bacterium Pseudomonas putida S12

    NARCIS (Netherlands)

    Kieboom, J.

    2002-01-01

    The aim of the research presented in this thesis was to study the molecular mechanisms of organic solvent tolerance in Pseudomonas putida S12. This bacterium is capable of growth at saturated solvent concentrations, which are lethal to normal bacteria. Organic solve

  15. Draft Genome Sequence of Burkholderia cenocepacia Strain 869T2, a Plant-Beneficial Endophytic Bacterium.

    Science.gov (United States)

    Ho, Ying-Ning; Huang, Chieh-Chen

    2015-11-12

    An endophytic bacterium, Burkholderia cenocepacia 869T2, isolated from vetiver grass, has shown its abilities for both in planta biocontrol and plant growth promotion. Its draft genome sequence was determined to provide insights into those metabolic pathways involved in plant-beneficial activity. This is the first genome report for endophytic B. cenocepacia.

  16. Hydrogen Production by Co-cultures of Rhizopus oryzae and a Photosynthetic Bacterium, Rhodobacter sphaeroides RV

    Science.gov (United States)

    Asada, Yasuo; Ishimi, Katsuhiro; Nagata, Yoko; Wakayama, Tatsuki; Miyake, Jun; Kohno, Hideki

    Hydrogen production with glucose by using co-immobilized cultures of a fungus, Rhizopus oryzae NBRC5384, and a photosynthetic bacterium, Rhodobacter sphaeroides RV, in agar gels was studied. The co-immobilized cultures converted glucose to hydrogen via lactate in a high molar yield of about 8moles of hydrogen per glucose at a maximum under illuminated conditions.

  17. Inactivation of Glutamine Synthetase by Ammonia Shock in the Gram-Positive Bacterium Streptomyces cattleya.

    Science.gov (United States)

    Wax, R; Synder, L; Kaplan, L

    1982-10-01

    In cultures of the gram-positive bacterium Streptomyces cattleya, a rapid inactivation of glutamine synthetase was seen after ammonia shock. pH activity curves for ammonia-shocked and control cultures are shown. A peak of glutamine synthetase activity was seen during fermentation for production of the antibiotic thienamycin.

  18. Draft Genome Sequence of the Moderately Halophilic Bacterium Pseudoalteromonas ruthenica Strain CP76.

    Science.gov (United States)

    de la Haba, Rafael R; Sánchez-Porro, Cristina; León, María José; Papke, R Thane; Ventosa, Antonio

    2013-05-23

    Pseudoalteromonas ruthenica strain CP76, isolated from a saltern in Spain, is a moderately halophilic bacterium belonging to the Gammaproteobacteria. Here we report the draft genome sequence, which consists of a 4.0-Mb chromosome, of this strain, which is able to produce the extracellular enzyme haloprotease CPI.

  19. Engineering a predatory bacterium as a proficient killer agent for intracellular bio-products recovery

    DEFF Research Database (Denmark)

    Martinez, Virginia; Herencias, Cristina; Jurkevitch, Edouard;

    2016-01-01

    This work examines the potential of the predatory bacterium Bdellovibrio bacteriovorus HD100, an obligate predator of other Gram-negative bacteria, as an external cell-lytic agent for recovering valuable intracellular bio-products produced by prey cultures. The bio-product targets to be recovered...

  20. A commensal symbiotic interrelationship for the growth of Symbiobacterium toebii with its partner bacterium, Geobacillus toebii

    Directory of Open Access Journals (Sweden)

    Masui Ryoji

    2011-10-01

    Full Text Available Abstract Background Symbiobacterium toebii is a commensal symbiotic thermophile that absolutely requires its partner bacterium Geobacillus toebii for growth. Despite development of an independent cultivation method using cell-free extracts, the growth of Symbiobacterium remains unknown due to our poor understanding of the symbiotic relationship with its partner bacterium. Here, we investigated the interrelationship between these two bacteria for growth of S. toebii using different cell-free extracts of G. toebii. Results Symbiobacterium toebii growth-supporting factors were constitutively produced through almost all growth phases and under different oxygen tensions in G. toebii, indicating that the factor may be essential components for growth of G. toebii as well as S. toebii. The growing conditions of G. toebii under different oxygen tension dramatically affected to the initial growth of S. toebii and the retarded lag phase was completely shortened by reducing agent, L-cysteine indicating an evidence of commensal interaction of microaerobic and anaerobic bacterium S. toebii with a facultative aerobic bacterium G. toebii. In addition, the growth curve of S. toebii showed a dependency on the protein concentration of cell-free extracts of G. toebii, demonstrating that the G. toebii-derived factors have nutrient-like characters but not quorum-sensing characters. Conclusions Not only the consistent existence of the factor in G. toebii during all growth stages and under different oxygen tensions but also the concentration dependency of the factor for proliferation and optimal growth of S. toebii, suggests that an important biosynthetic machinery lacks in S. toebii during evolution. The commensal symbiotic bacterium, S. toebii uptakes certain ubiquitous and essential compound for its growth from environment or neighboring bacteria that shares the equivalent compounds. Moreover, G. toebii grown under aerobic condition shortened the lag phase of S

  1. Draft genome of an Aerophobetes bacterium reveals a facultative lifestyle in deep-sea anaerobic sediments

    KAUST Repository

    Wang, Yong

    2016-07-01

    Aerophobetes (or CD12) is a recently defined bacterial phylum, of which the metabolic processes and ecological importance remain unclear. In the present study, we obtained the draft genome of an Aerophobetes bacterium TCS1 from saline sediment near the Thuwal cold seep in the Red Sea using a genome binning method. Analysis of 16S rRNA genes of TCS1 and close relatives revealed wide distribution of Aerophobetes in deep-sea sediments. Phylogenetic relationships showed affinity between Aerophobetes TCS1 and some thermophilic bacterial phyla. The genome of TCS1 (at least 1.27 Mbp) contains a full set of genes encoding core metabolic pathways, including glycolysis and pyruvate fermentation to produce acetyl-CoA and acetate. The identification of cross-membrane sugar transporter genes further indicates its potential ability to consume carbohydrates preserved in the sediment under the microbial mat. Aerophobetes bacterium TCS1 therefore probably carried out saccharolytic and fermentative metabolism. The genes responsible for autotrophic synthesis of acetyl-CoA via the Wood–Ljungdahl pathway were also found in the genome. Phylogenetic study of the essential genes for the Wood–Ljungdahl pathway implied relative independence of Aerophobetes bacterium from the known acetogens and methanogens. Compared with genomes of acetogenic bacteria, Aerophobetes bacterium TCS1 genome lacks the genes involved in nitrogen metabolism, sulfur metabolism, signal transduction and cell motility. The metabolic activities of TCS1 might depend on geochemical conditions such as supplies of CO2, hydrogen and sugars, and therefore the TCS1 might be a facultative bacterium in anaerobic saline sediments near cold seeps. © 2016, Science China Press and Springer-Verlag Berlin Heidelberg.

  2. A fragile metabolic network adapted for cooperation in the symbiotic bacterium Buchnera aphidicola

    Directory of Open Access Journals (Sweden)

    Goryanin Igor

    2009-02-01

    Full Text Available Abstract Background In silico analyses provide valuable insight into the biology of obligately intracellular pathogens and symbionts with small genomes. There is a particular opportunity to apply systems-level tools developed for the model bacterium Escherichia coli to study the evolution and function of symbiotic bacteria which are metabolically specialised to overproduce specific nutrients for their host and, remarkably, have a gene complement that is a subset of the E. coli genome. Results We have reconstructed and analysed the metabolic network of the γ-proteobacterium Buchnera aphidicola (symbiont of the pea aphid as a model for using systems-level approaches to discover key traits of symbionts with small genomes. The metabolic network is extremely fragile with > 90% of the reactions essential for viability in silico; and it is structured so that the bacterium cannot grow without producing the essential amino acid, histidine, which is released to the insect host. Further, the amount of essential amino acid produced by the bacterium in silico can be controlled by host supply of carbon and nitrogen substrates. Conclusion This systems-level analysis predicts that the fragility of the bacterial metabolic network renders the symbiotic bacterium intolerant of drastic environmental fluctuations, whilst the coupling of histidine production to growth prevents the bacterium from exploiting host nutrients without reciprocating. These metabolic traits underpin the sustained nutritional contribution of B. aphidicola to the host and, together with the impact of host-derived substrates on the profile of nutrients released from the bacteria, point to a dominant role of the host in controlling the symbiosis.

  3. Draft genome of an Aerophobetes bacterium reveals a facultative lifestyle in deep-sea anaerobic sediments

    Institute of Scientific and Technical Information of China (English)

    Yong Wang; Zhao-Ming Gao; Jiang-Tao Li; Salim Bougouffa; Ren Mao Tian; Vladimir B.Bajic; Pei-Yuan Qian

    2016-01-01

    Aerophobetes (or CD12) is a recently defined bacterial phylum,of which the metabolic processes and ecological importance remain unclear.In the present study,we obtained the draft genome of an Aerophobetes bacterium TCS1 from saline sediment near the Thuwal cold seep in the Red Sea using a genome binning method.Analysis of 16S rRNA genes of TCS1 and close relatives revealed wide distribution of Aerophobetes in deep-sea sediments.Phylogenetic relationships showed affinity between Aerophobetes TCS1 and some thermophilic bacterial phyla.The genome of TCS1 (at least 1.27 Mbp)contains a full set of genes encoding core metabolic pathways,including glycolysis and pyruvate fermentation to produce acetyl-CoA and acetate.The identification of cross-membrane sugar transporter genes further indicates its potential ability to consume carbohydrates preserved in the sediment under the microbial mat.Aerophobetes bacterium TCS1 therefore probably carried out saccharolytic and fermentative metabolism.The genes responsible for autotrophic synthesis of acetyl-CoA via the Wood-Ljungdahl pathway were also found in the genome.Phylogenetic study of the essential genes for the Wood-Ljungdahl pathway implied relative independence of Aerophobetes bacterium from the known acetogens and methanogens.Compared with genomes of acetogenic bacteria,Aerophobetes bacterium TCS 1 genome lacks the genes involved in nitrogen metabolism,sulfur metabolism,signal transduction and cell motility.The metabolic activities of TCS1 might depend on geochemical conditions such as supplies of CO2,hydrogen and sugars,and therefore the TCS1 might be a facultative bacterium in anaerobic saline sediments near cold seeps.

  4. Research on Anti-Corrosion of Thiobacillus for the Geopolymer Solidification MSWI Fly Ash%地聚物固化生活垃圾焚烧飞灰固化体抗氧化硫杆菌腐蚀性能的研究

    Institute of Scientific and Technical Information of China (English)

    金漫彤; 孙鑫; 董海丽; 金赞芳

    2012-01-01

    In order to discuss the anti-Thiobacillus corrosion performance of geopolymer solidification MSWI fly ash,the research simulated the Thiobacillus corrosion process by experiment,investigated the change of mass,compressive strength,leaching concentration.The results showed that geopolymer had a good anti-corrosion ability: weight loss within 1%,the compressive strength still reached 21.88 MPa after 28 days,the corrosion resistance coefficient was above 0.9.The maximum leaching concentration of Cr,Cu,Zn,Cd,Hg,Pb were 107.7 μg·L^-1,22.71 μg·L^-1,39.18 μg·L^-1,0.56 μg·L^-1,34.84 μg·L^-1and 3.03 μg·L^-1,respectively.And the leaching concentration of geopolymer reduced with the immersion time,showed a good anti-Thiobacillus corrosion performance.Through the X-ray diffraction,Fourier transform infrared spectroscopy,scanning electron microscope spectra of geopolymer,we investigated the microstructure and mechanism of geopolymer anti-corrosion.%为了探讨地聚合物固化生活垃圾焚烧飞灰后形成的固化体抗强酸性微生物的侵蚀性能,模拟氧化硫杆菌的腐蚀过程,考察经氧化硫杆菌浸泡前后地聚物固化体质量、抗压强度、浸出浓度的变化.结果表明,地聚物固化体具有良好的抗氧化硫杆菌侵蚀能力:浸泡28 d后,质量损失〈1%;抗压强度仍达到了21.88MPa,抗蚀系数在0.9以上;重金属Cr、Cu、Zn、Cd、Hg、Pb的最大浸出浓度仅为:107.7、22.71、39.18、0.56、34.84和3.03μg.L^-1.并且重金属的浸出浓度随浸泡时间而降低,表明了地聚物具有良好的抗氧化硫杆菌腐蚀的性能.实验通过X-ray衍射(XRD)、傅立叶红外光谱(FTIR)、扫描电镜(SEM)的分析对地聚物固化体的微观结构进行了表征,并探讨了地聚物固化体抗酸腐蚀性能的机制.

  5. Effect of Sulfate Reduced Bacterium on Corrosion Behavior of 10CrMoAl Steel

    Institute of Scientific and Technical Information of China (English)

    WANG Hua; LIANG Cheng-hao

    2007-01-01

    The effects of sulfate reduced bacterium (SRB) on the corrosion behavior of 10CrMoAl steel in seawater were studied by chemical immersion, potentiodynamic polarization, electrochemical impedance spectroscopy measurement, and scanning electron microscope techniques. The results show that the content of element sulfur in the corrosion product of 10CrMoAl steel in seawater with SRB is up to 9.23%, which is higher than that of the same in sterile seawater. X-ray diffraction demonstrates that the main corrosion product is FeS. SRB increases the corrosion rate by anodic depolarization of the metabolized sulfide product. SEM observation indicates that the corrosion product is not distributed continuously; in addition, bacilliform sulfate-reduced bacterium accumulates on the local surface of 10CrMoAl steel. Hence, SRB enhances sensitivity to the localized corrosion of 10CrMoAl steel in seawater.

  6. Melanin from the nitrogen-fixing bacterium Azotobacter chroococcum: a spectroscopic characterization.

    Science.gov (United States)

    Banerjee, Aulie; Supakar, Subhrangshu; Banerjee, Raja

    2014-01-01

    Melanins, the ubiquitous hetero-polymer pigments found widely dispersed among various life forms, are usually dark brown/black in colour. Although melanins have variety of biological functions, including protection against ultraviolet radiation of sunlight and are used in medicine, cosmetics, extraction of melanin from the animal and plant kingdoms is not an easy task. Using complementary physicochemical techniques (i.e. MALDI-TOF, FTIR absorption and cross-polarization magic angle spinning solid-state (13)C NMR), we report here the characterization of melanins extracted from the nitrogen-fixing non-virulent bacterium Azotobacter chroococcum, a safe viable source. Moreover, considering dihydroxyindole moiety as the main constituent, an effort is made to propose the putative molecular structure of the melanin hetero-polymer extracted from the bacterium. Characterization of the melanin obtained from Azotobacter chroococcum would provide an inspiration in extending research activities on these hetero-polymers and their use as protective agent against UV radiation.

  7. Economic Game Theory to Model the Attenuation of Virulence of an Obligate Intracellular Bacterium.

    Science.gov (United States)

    Tago, Damian; Meyer, Damien F

    2016-01-01

    Diseases induced by obligate intracellular pathogens have a large burden on global human and animal health. Understanding the factors involved in the virulence and fitness of these pathogens contributes to the development of control strategies against these diseases. Based on biological observations, a theoretical model using game theory is proposed to explain how obligate intracellular bacteria interact with their host. The equilibrium in such a game shows that the virulence and fitness of the bacterium is host-triggered and by changing the host's defense system to which the bacterium is confronted, an evolutionary process leads to an attenuated strain. Although, the attenuation procedure has already been conducted in practice in order to develop an attenuated vaccine (e.g., with Ehrlichia ruminantium), there was a lack of understanding of the theoretical basis behind this process. Our work provides a model to better comprehend the existence of different phenotypes and some underlying evolutionary mechanisms for the virulence of obligate intracellular bacteria.

  8. Isolation and biological characteristics of aerobic marine magnetotactic bacterium YSC-1

    Institute of Scientific and Technical Information of China (English)

    GAO Jun; PAN Hongmiao; YUE Haidong; SONG Tao; ZHAO Yong; CHEN Guanjun; Wu Longfei; XIAO Tian

    2006-01-01

    Magnetotactic bacteria have become a hot spot of research in microbiology attracting intensive interest of researchers in multiple disciplinary fields. However, the studies were limited in few fastidious bacteria. The objective of this study aims at isolating new marine magnetic bacteria and better comprehension of magnetotactic bacteria. In this study, an aerobic magnetotactic bacterium YSC-1 was isolated from sediments in the Yellow Sea Cold Water Mass (YSCWM). In TEM, magnetic cells have one or several circular magnetosomes in dimeter of 100nm, and consist of Fe and Co shown on energy dispersive X-ray spectrum. The biological and physiological characteristics of this bacterium were also described. The colour of YSC-1 colony is white in small rod. The gran stain is negative. Results showed that Strain YSC-1 differs from microaerophile magnetotactic bacteria MS-1 and WD-1 in biology.

  9. The bacterium Xenorhabdus nematophila inhibits phospholipases A2 from insect, prokaryote, and vertebrate sources

    Science.gov (United States)

    Park, Youngjin; Kim, Yonggyun; Stanley, David

    The bacterium, Xenorhabdus nematophila, is a virulent insect pathogen. Part of its pathogenicity is due to impairing cellular immunity by blocking biosynthesis of eicosanoids, the major recognized signal transduction system in insect cellular immunity. X. nematophila inhibits the first step in eicosanoid biosynthesis, phospholipase A2 (PLA2). Here we report that the bacterium inhibits PLA2 from two insect immune tissues, hemocytes and fat body, as well as PLA2s selected to represent a wide range of organisms, including prokaryotes, insects, reptiles, and mammals. Our finding on a bacterial inhibitor of PLA2 activity contributes new insight into the chemical ecology of microbe-host interactions, which usually involve actions rather than inhibitors of PLA2s.

  10. Inflammasomes Coordinate Pyroptosis and Natural Killer Cell Cytotoxicity to Clear Infection by a Ubiquitous Environmental Bacterium.

    Science.gov (United States)

    Maltez, Vivien I; Tubbs, Alan L; Cook, Kevin D; Aachoui, Youssef; Falcone, E Liana; Holland, Steven M; Whitmire, Jason K; Miao, Edward A

    2015-11-17

    Defective neutrophils in patients with chronic granulomatous disease (CGD) cause susceptibility to extracellular and intracellular infections. Microbes must first be ejected from intracellular niches to expose them to neutrophil attack, so we hypothesized that inflammasomes detect certain CGD pathogens upstream of neutrophil killing. Here, we identified one such ubiquitous environmental bacterium, Chromobacterium violaceum, whose extreme virulence was fully counteracted by the NLRC4 inflammasome. Caspase-1 protected via two parallel pathways that eliminated intracellular replication niches. Pyroptosis was the primary bacterial clearance mechanism in the spleen, but both pyroptosis and interleukin-18 (IL-18)-driven natural killer (NK) cell responses were required for liver defense. NK cells cleared hepatocyte replication niches via perforin-dependent cytotoxicity, whereas interferon-γ was not required. These insights suggested a therapeutic approach: exogenous IL-18 restored perforin-dependent cytotoxicity during infection by the inflammasome-evasive bacterium Listeria monocytogenes. Therefore, inflammasomes can trigger complementary programmed cell death mechanisms, directing sterilizing immunity against intracellular bacterial pathogens.

  11. Economic Game Theory to Model the Attenuation of Virulence of an Obligate Intracellular Bacterium

    Science.gov (United States)

    Tago, Damian; Meyer, Damien F.

    2016-01-01

    Diseases induced by obligate intracellular pathogens have a large burden on global human and animal health. Understanding the factors involved in the virulence and fitness of these pathogens contributes to the development of control strategies against these diseases. Based on biological observations, a theoretical model using game theory is proposed to explain how obligate intracellular bacteria interact with their host. The equilibrium in such a game shows that the virulence and fitness of the bacterium is host-triggered and by changing the host's defense system to which the bacterium is confronted, an evolutionary process leads to an attenuated strain. Although, the attenuation procedure has already been conducted in practice in order to develop an attenuated vaccine (e.g., with Ehrlichia ruminantium), there was a lack of understanding of the theoretical basis behind this process. Our work provides a model to better comprehend the existence of different phenotypes and some underlying evolutionary mechanisms for the virulence of obligate intracellular bacteria. PMID:27610355

  12. Regulation of glutamine synthetase activity by adenylylation in the Gram-positive bacterium Streptomyces cattleya.

    Science.gov (United States)

    Streicher, S L; Tyler, B

    1981-01-01

    The enzymatic activity of glutamine synthetase [GS; L-glutamate:ammonia ligase (ADP-forming), EC 6.3.1.2] from the Gram-positive bacterium Streptomyces cattleya is regulated by covalent modification. In whole cells containing high levels of GS the addition of ammonium chloride leads to a rapid decline in GS activity. Crude extracts prepared from such ammonia-shocked cells had very low levels of GS activity as measured by biosynthetic and gamma-glutamyltransferase assays. Incubation of the crude extracts with snake venom phosphodiesterase restored GS activity. In cell extracts, GS was also inactivated by an ATP- and glutamine-dependent reaction. Radioactive labeling studies demonstrated the incorporation of an AmP moiety into GS protein upon modification. Our results suggest a covalent modification of GS in a Gram-positive bacterium. This modification appears to be adenylylation of the GS subunit similar to that found in the Gram-negative bacteria.

  13. A Streamlined Strategy for Biohydrogen Production with Halanaerobium hydrogeniformans, an Alkaliphilic Bacterium.

    Science.gov (United States)

    Begemann, Matthew B; Mormile, Melanie R; Sitton, Oliver C; Wall, Judy D; Elias, Dwayne A

    2012-01-01

    Biofuels are anticipated to enable a shift from fossil fuels for renewable transportation and manufacturing fuels, with biohydrogen considered attractive since it could offer the largest reduction of global carbon budgets. Currently, lignocellulosic biohydrogen production remains inefficient with pretreatments that are heavily fossil fuel-dependent. However, bacteria using alkali-treated biomass could streamline biofuel production while reducing costs and fossil fuel needs. An alkaliphilic bacterium, Halanaerobiumhydrogeniformans, is described that is capable of biohydrogen production at levels rivaling neutrophilic strains, but at pH 11 and hypersaline conditions. H. hydrogeniformans ferments a variety of 5- and 6-carbon sugars derived from hemicellulose and cellulose including cellobiose, and forms the end products hydrogen, acetate, and formate. Further, it can also produce biohydrogen from switchgrass and straw pretreated at temperatures far lower than any previously reported and in solutions compatible with growth. Hence, this bacterium can potentially increase the efficiency and efficacy of biohydrogen production from renewable biomass resources.

  14. A Streamlined Strategy for Biohydrogen Production with Halanaerobium hydrogeniformans, an Alkaliphilic Bacterium

    Directory of Open Access Journals (Sweden)

    Matthew eBegemann

    2012-03-01

    Full Text Available Biofuels are anticipated to enable a shift from fossil fuels for renewable transportation and manufacturing fuels, with biohydrogen considered attractive since it could offer the largest reduction of global carbon budgets. Currently, lignocellulosic biohydrogen production remains inefficient with pretreatments that are heavily fossil fuel-dependent. However, bacteria using alkali-treated biomass could streamline biofuel production while reducing costs and fossil fuel needs. An alkaliphilic bacterium, Halanaerobium hydrogeniformans, is described that is capable of biohydrogen production at levels rivaling neutrophilic strains, but at pH 11 and hypersaline conditions. H. hydrogeniformans ferments a variety of 5- and 6- carbon sugars derived from hemicellulose and cellulose including cellobiose, and forms the end products hydrogen, acetate and formate. Further, it can also produce biohydrogen from switchgrass and straw pretreated at temperatures far lower than any previously reported and in solutions compatible with growth. Hence, this bacterium can potentially increase the efficiency and efficacy of biohydrogen production from renewable biomass resources.

  15. Draft Genome Sequence of Uncultured SAR324 Bacterium lautmerah10, Binned from a Red Sea Metagenome

    KAUST Repository

    Haroon, Mohamed

    2016-02-11

    A draft genome of SAR324 bacterium lautmerah10 was assembled from a metagenome of a surface water sample from the Red Sea, Saudi Arabia. The genome is more complete and has a higher G+C content than that of previously sequenced SAR324 representatives. Its genomic information shows a versatile metabolism that confers an advantage to SAR324, which is reflected in its distribution throughout different depths of the marine water column.

  16. Draft Genome Sequence of the Antitrypanosomally Active Sponge-Associated Bacterium Actinokineospora sp. Strain EG49

    KAUST Repository

    Harjes, Janno

    2014-03-06

    The marine sponge-associated bacterium Actinokineospora sp. strain EG49 produces the antitrypanosomal angucycline-like compound actinosporin A. The draft genome of Actinokineospora sp. EG49 has a size of 7.5 megabases and a GC content of 72.8% and contains 6,629 protein-coding sequences (CDS). antiSMASH predicted 996 genes residing in 36 secondary metabolite gene clusters.

  17. Sexual transmission of a plant pathogenic bacterium, Candidatus Liberibacter asiaticus, between conspecific insect vectors during mating.

    Directory of Open Access Journals (Sweden)

    Rajinder S Mann

    Full Text Available Candidatus Liberibacter asiaticus is a fastidious, phloem-inhabiting, gram-negative bacterium transmitted by Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae. The bacterium is the presumed causal agent of huanglongbing (HLB, one of the most destructive and economically important diseases of citrus. We investigated whether Las is transmitted between infected and uninfected D. citri adults during courtship. Our results indicate that Las was sexually transmitted from Las-infected male D. citri to uninfected females at a low rate (<4% during mating. Sexual transmission was not observed following mating of infected females and uninfected males or among adult pairs of the same sex. Las was detected in genitalia of both sexes and also in eggs of infected females. A latent period of 7 days or more was required to detect the bacterium in recipient females. Rod shaped as well as spherical structures resembling Las were observed in ovaries of Las-infected females with transmission electron microscopy, but were absent in ovaries from uninfected D. citri females. The size of the rod shaped structures varied from 0.39 to 0.67 µm in length and 0.19 to 0.39 µm in width. The spherical structures measured from 0.61 to 0.80 µm in diameter. This investigation provides convincing evidence that a plant pathogenic bacterium is sexually transmitted from male to female insects during courtship and established evidence that bacteria persist in reproductive organs. Moreover, these findings provide an alternative sexually horizontal mechanism for the spread of Las within populations of D. citri, even in the absence of infected host trees.

  18. Five new amicoumacins isolated from a marine-derived Bacterium bacillus subtilis

    KAUST Repository

    Li, Yongxin

    2012-02-03

    Four novel amicoumacins, namely lipoamicoumacins A-D (1-4), and one new bacilosarcin analog (5) were isolated from culture broth of a marine-derived bacterium Bacillus subtilis, together with six known amicoumacins. Their structures were elucidated on the basis of extensive spectroscopic (2D NNR, IR, CD and MS) analysis and in comparison with data in literature. 2012 by the authors; licensee MDPI.

  19. Insights in Nanoparticle-Bacterium Interactions: New Frontiers to Bypass Bacterial Resistance to Antibiotics.

    Science.gov (United States)

    Diab, Roudayna; Khameneh, Bahman; Joubert, Olivier; Duval, Raphael

    2015-01-01

    Nanotechnology has been revealed as a fundamental approach for antibiotics delivery. In this paper, recent findings demonstrating the superiority of nanocarried-antibiotics over "naked" ones and the ways by which nanoparticles can help to overwhelm bacterial drug resistance are reviewed. The second part of this paper sheds light on nanoparticle-bacterium interaction patterns. Finally, key factors affecting the effectiveness of nanoparticles interactions with bacteria are discussed.

  20. Two New Cholic Acid Derivatives from the Marine Ascidian-Associated Bacterium Hasllibacter halocynthiae

    Directory of Open Access Journals (Sweden)

    Sung Hun Kim

    2012-10-01

    Full Text Available The investigation of secondary metabolites in liquid cultures of a recently discovered marine bacterium, Hasllibacter halocynthiae strain KME 002T, led to the isolation of two new cholic acid derivatives. The structures of these compounds were determined to be 3,3,12-trihydroxy-7-ketocholanic acid (1 and 3,3,12-trihydroxy-7-deoxycholanic acid (2 through HRFABMS and NMR data analyses.

  1. Degradation of p-nitrophenol by the phototrophic bacterium Rhodobacter capsulatus.

    Science.gov (United States)

    Roldán, M D; Blasco, R; Caballero, F J; Castillo, F

    1998-01-01

    The phototrophic bacterium Rhodobacter capsulatus detoxified p-nitrophenol and 4-nitrocatechol. The bacterium tolerated moderate concentrations of p-nitrophenol (up to 0.5 mM) and degraded it under light at an optimal O2 pressure of 20 kPa. The bacterium did not metabolize the xenobiotic in the dark or under strictly anoxic conditions or high O2 pressure. Bacterial growth with acetate in the presence of p-nitrophenol took place with the simultaneous release of nonstoichiometric amounts of 4-nitrocatechol, which can also be degraded by the bacterium. Crude extracts from R. capsulatus produced 4-nitrocatechol from p-nitrophenol upon the addition of NAD(P)H, although at a very low rate. A constitutive catechol 1, 2-dioxygenase activity yielding cis,cis-muconate was also detected in crude extracts of R. capsulatus. Further degradation of 4-nitrocatechol included both nitrite- and CO2-releasing steps since: (1) a strain of R. capsulatus (B10) unable to assimilate nitrate and nitrite released nitrite into the medium when grown with p-nitrophenol or 4-nitrocatechol, and the nitrite concentration was stoichiometric with the 4-nitrocatechol degraded, and (2) cultures of R. capsulatus growing microaerobically produced low amounts of 14CO2 from radiolabeled p-nitrophenol. The radioactivity was also incorporated into cellular compounds from cells grown with uniformly labeled 14C-p-nitrophenol. From these results we concluded that the xenobiotic is used as a carbon source by R. capsulatus, but that only the strain able to assimilate nitrite (E1F1) can use p-nitrophenol as a nitrogen source.

  2. Identifying the assembly pathway of cyanophage inside the marine bacterium using electron cryo-tomography

    Directory of Open Access Journals (Sweden)

    Wei Dai

    2014-01-01

    Full Text Available Advances in electron cryo-tomography open up a new avenue to visualize the 3-D internal structure of a single bacterium before and after its infection by bacteriophages in its native environment, without using chemical fixatives, fluorescent dyes or negative stains. Such direct observation reveals the presence of assembly intermediates of the bacteriophage and thus allows us to map out the maturation pathway of the bacteriophage inside its host.

  3. Identifying the assembly pathway of cyanophage inside the marine bacterium using electron cryo-tomography.

    Science.gov (United States)

    Dai, Wei; Schmid, Michael F; King, Jonathan A; Chiu, Wah

    2014-06-01

    Advances in electron cryo-tomography open up a new avenue to visualize the 3-D internal structure of a single bacterium before and after its infection by bacteriophages in its native environment, without using chemical fixatives, fluorescent dyes or negative stains. Such direct observation reveals the presence of assembly intermediates of the bacteriophage and thus allows us to map out the maturation pathway of the bacteriophage inside its host.

  4. Identifying the assembly pathway of cyanophage inside the marine bacterium using electron cryo-tomography

    OpenAIRE

    Wei Dai; Schmid, Michael F.; King, Jonathan A.; Wah Chiu

    2014-01-01

    Advances in electron cryo-tomography open up a new avenue to visualize the 3-D internal structure of a single bacterium before and after its infection by bacteriophages in its native environment, without using chemical fixatives, fluorescent dyes or negative stains. Such direct observation reveals the presence of assembly intermediates of the bacteriophage and thus allows us to map out the maturation pathway of the bacteriophage inside its host.

  5. Draft Genome Sequence of Agarivorans albus Strain MKT 106T, an Agarolytic Marine Bacterium.

    Science.gov (United States)

    Yasuike, Motoshige; Nakamura, Yoji; Kai, Wataru; Fujiwara, Atushi; Fukui, Youhei; Satomi, Masataka; Sano, Motohiko

    2013-07-18

    Agarivorans albus is a Gram-negative, strictly aerobic, and agar-hydrolyzing marine bacterium. We present the draft genome sequence of the A. albus strain MKT 106(T), which is composed of 67 contigs (>500 bp) totaling 4,734,285 bp and containing 4,397 coding DNA sequences (CDSs), four rRNAs, and 64 tRNA sequences.

  6. Genome Sequence of Marine Bacterium Idiomarina sp. Strain 28-8, Isolated from Korean Ark Shells.

    Science.gov (United States)

    Kim, Woo-Jin; Kim, Young-Ok; Kim, Dong-Gyun; Nam, Bo-Hye; Kong, Hee Jeong; Jung, Hyungtaek; Lee, Sang-Jun; Kim, Dong-Wook; Kim, Dae-Soo; Chae, Sung-Hwa

    2013-10-03

    Idiomarina sp. strain 28-8 is an aerobic, Gram-negative, flagellar bacterium isolated from the bodies of ark shells (Scapharca broughtonii) collected from underwater sediments in Gangjin Bay, South Korea. Here, we present the draft genome sequence of Idiomarina sp. 28-8 (2,971,606 bp, with a G+C content of 46.9%), containing 2,795 putative coding sequences.

  7. Cadmium resistance and uptake by bacterium, Salmonella enterica 43C, isolated from industrial effluent.

    Science.gov (United States)

    Khan, Zaman; Rehman, Abdul; Hussain, Syed Z; Nisar, Muhammad A; Zulfiqar, Soumble; Shakoori, Abdul R

    2016-12-01

    Cadmium resistant bacterium, isolated from industrial wastewater, was characterized as Salmonella enterica 43C on the basis of biochemical and 16S rRNA ribotyping. It is first ever reported S. enterica 43C bared extreme resistance against heavy metal consortia in order of Pb(2+)>Cd(2+)>As(3+)>Zn(2+)>Cr(6+)>Cu(2+)>Hg(2+). Cd(2+) stress altered growth pattern of the bacterium in time dependent manner. It could remove nearly 57 % Cd(2+) from the medium over a period of 8 days. Kinetic and thermodynamic studies based on various adsorption isotherm models (Langmuir and Freundlich) depicted the Cd(2+) biosorption as spontaneous, feasible and endothermic in nature. Interestingly, the bacterium followed pseudo first order kinetics, making it a good biosorbent for heavy metal ions. The S. enterica 43C Cd(2+) processivity was significantly influenced by temperature, pH, initial Cd(2+) concentration, biomass dosage and co-metal ions. FTIR analysis of the bacterium revealed the active participation of amide and carbonyl moieties in Cd(2+) adsorption confirmed by EDX analysis. Electron micrographs beckoned further surface adsorption and increased bacterial size due to intracellular Cd(2+) accumulation. An overwhelming increase in glutathione and other non-protein thiols levels played a significant role in thriving oxidative stress generated by metal cations. Presence of metallothionein clearly depicted the role of such proteins in bacterial metal resistance mechanism. The present study results clearly declare S. enterica 43C a suitable candidate for green chemistry to bioremediate environmental Cd(2+).

  8. Biological control and endophytism of the olive root bacterium Pseudomonas fluorescens PICF7

    OpenAIRE

    Maldonado González, Mercedes

    2015-01-01

    Olive (Olea europaea L.) has always been a fundamental crop in the Mediterranean Basin. Driven by the fact, among others, that an increasing number of scientific reports highlight the benefits that olive oil consumption has for human health, olive tree cultivation has spread worldwide to other regions with Mediterranean-type climate. Two relevant pathogens affecting olive trees are the hemibiotrophic soil-borne fungus Verticillium dahliae and the bacterium Pseudomonas savastano...

  9. Draft Genome Sequence of the Cyanide-Utilizing Bacterium Pseudomonas fluorescens Strain NCIMB 11764

    OpenAIRE

    2012-01-01

    We report here the 6.97-Mb draft genome sequence of Pseudomonas fluorescens strain NCIMB 11764, which is capable of growth on cyanide as the sole nitrogen source. The draft genome sequence allowed the discovery of several genes implicated in enzymatic cyanide turnover and provided additional information contributing to a better understanding of this organism's unique cyanotrophic ability. This is the first sequenced genome of a cyanide-assimilating bacterium.

  10. Draft genome sequence of the cyanide-utilizing bacterium Pseudomonas fluorescens strain NCIMB 11764.

    Science.gov (United States)

    Vilo, Claudia A; Benedik, Michael J; Kunz, Daniel A; Dong, Qunfeng

    2012-12-01

    We report here the 6.97-Mb draft genome sequence of Pseudomonas fluorescens strain NCIMB 11764, which is capable of growth on cyanide as the sole nitrogen source. The draft genome sequence allowed the discovery of several genes implicated in enzymatic cyanide turnover and provided additional information contributing to a better understanding of this organism's unique cyanotrophic ability. This is the first sequenced genome of a cyanide-assimilating bacterium.

  11. Permanent draft genome of the malachite-green-tolerant bacterium Rhizobium sp. MGL06.

    Science.gov (United States)

    Liu, Yang; Wang, Runping; Zeng, Runying

    2014-12-01

    Rhizobium sp. MGL06, the first Rhizobium isolate from a marine environment, is a malachite-green-tolerant bacterium with a broader salinity tolerance (range: 0.5% to 9%) than other rhizobia. This study sequences and annotates the draft genome sequence of this strain. Genome sequence information provides a basis for analyzing the malachite green tolerance, broad salinity adaptation, nitrogen fixation properties, and taxonomic classification of the isolate.

  12. Complete genome sequence of Rufibacter tibetensis strain 1351, a radiation-resistant bacterium from Tibet plateau.

    Science.gov (United States)

    Zhang, Yi; Yu, Can; Zhou, Mengzhou; Tang, Jingfeng; Li, Xin; Wang, Zhi; Li, Zhijun; Yao, Juan; Li, Pei; Zheng, Guobin; Chen, Xiong; Dai, Jun

    2015-12-20

    Rufibacter tibetensis strain 1351, isolated from the soil of the Tibet plateau of China, belongs to the family of Cytophagaceae. It is a red-pigmented, gram-negative, strictly aerobic and rod-shaped bacterium and shows resistance to UV radiation. Here, we report its complete genome sequence, which can help us find the key genes of the carotenoid biosynthesis and resistance to UV radiation.

  13. Fourier transform infrared spectroscopic study of intact cells of the nitrogen-fixing bacterium Azospirillum brasilense

    Science.gov (United States)

    Kamnev, A. A.; Ristić, M.; Antonyuk, L. P.; Chernyshev, A. V.; Ignatov, V. V.

    1997-06-01

    The data of Fourier transform infrared (FTIR) spectroscopic measurements performed on intact cells of the soil nitrogen-fixing bacterium Azospirillum brasilense grown in a standard medium and under the conditions of an increased metal uptake are compared and discussed. The structural FTIR information obtained is considered together with atomic absorption spectrometry (AAS) data on the content of metal cations in the bacterial cells. Some methodological aspects concerning preparation of bacterial cell samples for FTIR measurements are also discussed.

  14. 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.

  15. Bacillus marcorestinctum sp. nov., a Novel Soil Acylhomoserine Lactone Quorum-Sensing Signal Quenching Bacterium

    OpenAIRE

    Xianzhen Li; Bo Zhu; Nuo Li; Fang Chen; Yan Han

    2010-01-01

    A Gram-positive, facultatively anaerobic, endospore-forming and rod-shaped bacterium was isolated from soil samples and designated strain LQQ. This organism strongly quenches the acylhomoserine lactone quorum-sensing signal. The LQQ strain exhibits phenotypic characteristics consistent with its classification in the genus Bacillus. It is positive in catalase and no special growth factor is needed. It uses glucose as sole carbon source. The DNA G + C content is 39.8 mol %. The closest relative...

  16. Genetic Engineering of a Radiation-Resistant Bacterium for Biodegradation of Mixed Wastes--Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Mary E. Lidstrom

    2003-12-26

    Aqueous mixed low level wastes (MLLW) containing radionuclides, solvents, and/or heavy metals represent a serious current and future problem for DOE environmental management and cleanup. In order to provide low-cost treatment alternatives under mild conditions for such contained wastes, we have proposed to use the radiation-resistant bacterium, Deinococcus radiodurans. This project has focused on developing D. radiodurans strains for dual purpose processes: cometabolic treatment of haloorganics and other solvents and removal of heavy metals from waste streams in an above-ground reactor system. The characteristics of effective treatment strains that must be attained are: (a) high biodegradative and metal binding activity; (b) stable treatment characteristics in the absence of selection and in the presence of physiological stress; (c) survival and activity under harsh chemical conditions, including radiation. The result of this project has been a suite of strains with high biodegradative capabilities that are candidates for pilot stage treatment systems. In addition, we have determined how to create conditions to precipitate heavy metals on the surface of the bacterium, as the first step towards creating dual-use treatment strains for contained mixed wastes of importance to the DOE. Finally, we have analyzed stress response in this bacterium, to create the foundation for developing treatment processes that maximize degradation while optimizing survival under high stress conditions.

  17. Antimicrobial activity and biosynthesis of nanoparticles by endophytic bacterium inhabiting Coffee arabica L.

    Directory of Open Access Journals (Sweden)

    Syed Baker

    2012-12-01

    Full Text Available The interface between endophytes and nanomaterials is a relatively new and unexplored area the present study evaluates screening of bacterial endophytes from surfaced sterilized leaf and stem segments of agro economical plant Coffee arabica L. towards synthesis of silver nanoparticles and antimicrobial metabolites. Among thirty two endophytes isolated nine isolates exhibited antimicrobial activity among which one bacterium was capable of extracellular synthesis of silver nanoparticles upon evaluation of supernatant with 1 mM of silver nitrate, biosynthesis of silver nanoparticles were assessed by UV-Visible Spectroscopy and the bacterium was capable of secreting antimicrobial secondary metabolites upon crude ethyl acetate extract evaluated for antimicrobial activity against panel of both gram positive and gram negative as well as phytopathogenic fungi. Partial characterization was carried out via bioautographic technique with Rf value 0.3 and 0.6 exhibiting antimicrobial activity against MRSA strain. Further studies in this area will be promising enough for molecular characterization of endophytic bacterium and chemical profiling of antimicrobial metabolites at the same time physiochemical characterization of nanoparticles will be valuable to reveal the size and shape. 

  18. Antagonism and Molecular Identification of an Antibiotic Bacterium BS04 Against Phytopathogenic Fungi and Bacteria

    Institute of Scientific and Technical Information of China (English)

    Xie Jing(谢晶); Ge Shaorong; Tao Yong; Gao Ping; Liu Kun; Liu Shigui

    2004-01-01

    Through a modified agar well diffusion assay, antagonism of bacterium BS04 is tested. The data show that BS04 has antibiotic activity against phytopathogenic fungi and bacteria, including Phoma wasabiae Yokogi, Cochlibolus Heterostrophu, Exserohilum Turcicum, Curuvularia Lunata (Walk) Boed, Thantephorus cucumris, Fusarium graminearum, Xanthomonas axonopodis pv. Citri (Hasse) Dye and Xanthomonas zingiberi (Uyeda) Savulescu. The products of bacterium BS04 can endure the treatment of a wide range of pH, and maintain the antibiotic activity after treatment of 100℃ for 30 min. The result suggests that bacterium BS04 has the potential as a promising biocontrol agent. In order to determine the taxonomic placement, the molecular identification of BS04 is performed. The comparative analysis of 16s rDNA sequences indicates that the 16s rDNA sequence of BS04 is highly homologous with sequences of typical Paenibacillus bacteria from the RPD library (from 92% to 99%). And the constructed phylogenetic tree by using maximum-likelihood method with Bootstrap Trial 1000 proves that BS04 is subjected to Paenibacillus polymyxa.

  19. Widespread association of a Rickettsiales-like bacterium with reef-building corals.

    Science.gov (United States)

    Casas, Veronica; Kline, David I; Wegley, Linda; Yu, Yanan; Breitbart, Mya; Rohwer, Forest

    2004-11-01

    White band disease type I (WBD I) has been a major cause of the dramatic decline of Acroporid coral populations throughout the Caribbean during the last two decades, yet the aetiological agent of this disease is unknown. In this study, the bacterial communities associated with both healthy and diseased Acropora species were compared by 16S rDNA analyses. The bacterial communities of both healthy and diseased Acropora spp. were dominated by a single ribotype with 90% identity to a bacterium in the order Rickettsiales. Screening by nested PCR specific to the coral-associated Rickettsiales 1 (CAR1) bacterium showed that this microbe was widespread in both healthy and diseased A. cervicornis and A. palmata corals from 'healthy' (i.e. low WBD I incidence) and 'stressed' reefs (i.e. high WBD I incidence). These results indicate that there were no dramatic changes in the composition of the microbial community associated with WBD I. CAR1 was also associated with non-Acroporid corals of the Caribbean, as well as with two Acroporid corals native to the Pacific. CAR1 was not present in the water column. This bacterium was also absent from preserved Caribbean Acroporid samples collected between 1937 and 1980 before the outbreak of WBD I. These results suggest CAR1 is a relatively new bacterial associate of Acroporids and that a non-bacterial pathogen might be the cause of WBD I.

  20. Rhodococcus sp. Q5, a novel agarolytic bacterium isolated from printing and dyeing wastewater.

    Science.gov (United States)

    Feng, Zehua; Peng, Lin; Chen, Mei; Li, Mengying

    2012-09-01

    An agar-degrading bacterium, Rhodococcus sp. Q5, was isolated from printing and dyeing wastewater using a mineral salts agar plate containing agar as the sole carbon source. The bacterium grew from pH 4.0 to 9.0, from 15 to 35°C, and in NaCl concentrations of 0-5 %; optimal values were pH 6.0, 30°C, and 1 % NaCl. Maximal agarase production was observed at pH 6.0 and 30°C. The bacterium did not require NaCl for growth or agarase production. The agarase secreted by Q5 was inducible by agar and was repressed by all simple sugars tested except lactose. Strain Q5 could hydrolyze starch but not cellulose or carboxymethyl cellulose. Agarase activity could also be detected in the medium when lactose or starch was the sole source of carbon and energy. Strain Q5 could grow in nitrogen-free mineral media; an organic nitrogen source was more effective than inorganic carbon sources for growth and agarase production. Addition of more organic nitrogen (peptone) to the medium corresponded with reduced agarase activity.

  1. Enhancement of survival and electricity production in an engineered bacterium by light-driven proton pumping.

    Science.gov (United States)

    Johnson, Ethan T; Baron, Daniel B; Naranjo, Belén; Bond, Daniel R; Schmidt-Dannert, Claudia; Gralnick, Jeffrey A

    2010-07-01

    Microorganisms can use complex photosystems or light-dependent proton pumps to generate membrane potential and/or reduce electron carriers to support growth. The discovery that proteorhodopsin is a light-dependent proton pump that can be expressed readily in recombinant bacteria enables development of new strategies to probe microbial physiology and to engineer microbes with new light-driven properties. Here, we describe functional expression of proteorhodopsin and light-induced changes in membrane potential in the bacterium Shewanella oneidensis strain MR-1. We report that there were significant increases in electrical current generation during illumination of electrochemical chambers containing S. oneidensis expressing proteorhodopsin. We present evidence that an engineered strain is able to consume lactate at an increased rate when it is illuminated, which is consistent with the hypothesis that proteorhodopsin activity enhances lactate uptake by increasing the proton motive force. Our results demonstrate that there is coupling of a light-driven process to electricity generation in a nonphotosynthetic engineered bacterium. Expression of proteorhodopsin also preserved the viability of the bacterium under nutrient-limited conditions, providing evidence that fulfillment of basic energy needs of organisms may explain the widespread distribution of proteorhodopsin in marine environments.

  2. Epidemiological analysis of acute diarrhea in children and inspection of pathogenic bacterium, viruses and other microorganisms

    Institute of Scientific and Technical Information of China (English)

    Li Hu; Yan Wang

    2016-01-01

    Objective:To investigate of epidemiological analysis of acute diarrhea in children, and to discuss the inspection of pathogenic bacterium, viruses and other microorganisms, in order to provide theoretical basis for the prevention and treatment of the disease.Methods: Five hundred and sixty-two cases of children with acute diarrhea treated in our center were selected as the research subjects, whose epidemiological data were analyzed. The fecal samples were collected for bacterial culture and identification, and the distribution characteristics of pathogenic bacteria were collected, then their relative characteristics were analyzed.Results:Children with acute diarrhea were more common in men aged 1-2 years old,and the incidence of time was more concentrated in June-August. There were four hundred and eighty-nine strains in the five hundred and sixty-two cases of children, among which the rate of viruses was the most, and the human rotavirus accounted for 30.67%, and the Shigella bacterium accounted for 20.65% in the total microorganisms, which was the highest detection rate of pathogenic bacterium. Rotavirus infection occured mainly in Winter, but the bacterial and goblet viral diarrhea was prevalent in summer.Conclusions:Children with acute diarrhea were more common in men aged 1-2 years old , and the rate of viruses in the detection of microorganisms is the highest, so targeted treatment should be taken according to the type of infection.

  3. Development of a markerless deletion system for the fish-pathogenic bacterium Flavobacterium psychrophilum.

    Science.gov (United States)

    Gómez, Esther; Álvarez, Beatriz; Duchaud, Eric; Guijarro, José A

    2015-01-01

    Flavobacterium psychrophilum is a Gram-negative fish pathogen that causes important economic losses in aquaculture worldwide. Although the genome of this bacterium has been determined, the function and relative importance of genes in relation to virulence remain to be established. To investigate their respective contribution to the bacterial pathogenesis, effective tools for gene inactivation are required. In the present study, a markerless gene deletion system has been successfully developed for the first time in this bacterium. Using this method, the F. psychrophilum fcpB gene, encoding a predicted cysteine protease homologous to Streptococcus pyogenes streptopain, was deleted. The developed system involved the construction of a conjugative plasmid that harbors the flanking sequences of the fcpB gene and an I-SceI meganuclease restriction site. Once this plasmid was integrated in the genome by homologous recombination, the merodiploid was resolved by the introduction of a plasmid expressing I-SceI under the control of the fpp2 F. psychrophilum inducible promoter. The resulting deleted fcpB mutant presented a decrease in extracellular proteolytic activity compared to the parental strain. However, there were not significant differences between their LD50 in an intramuscularly challenged rainbow trout infection model. The mutagenesis approach developed in this work represents an improvement over the gene inactivation tools existing hitherto for this "fastidious" bacterium. Unlike transposon mutagenesis and gene disruption, gene markerless deletion has less potential for polar effects and allows the mutation of virtually any non-essential gene or gene clusters.

  4. Development of a markerless deletion system for the fish-pathogenic bacterium Flavobacterium psychrophilum.

    Directory of Open Access Journals (Sweden)

    Esther Gómez

    Full Text Available Flavobacterium psychrophilum is a Gram-negative fish pathogen that causes important economic losses in aquaculture worldwide. Although the genome of this bacterium has been determined, the function and relative importance of genes in relation to virulence remain to be established. To investigate their respective contribution to the bacterial pathogenesis, effective tools for gene inactivation are required. In the present study, a markerless gene deletion system has been successfully developed for the first time in this bacterium. Using this method, the F. psychrophilum fcpB gene, encoding a predicted cysteine protease homologous to Streptococcus pyogenes streptopain, was deleted. The developed system involved the construction of a conjugative plasmid that harbors the flanking sequences of the fcpB gene and an I-SceI meganuclease restriction site. Once this plasmid was integrated in the genome by homologous recombination, the merodiploid was resolved by the introduction of a plasmid expressing I-SceI under the control of the fpp2 F. psychrophilum inducible promoter. The resulting deleted fcpB mutant presented a decrease in extracellular proteolytic activity compared to the parental strain. However, there were not significant differences between their LD50 in an intramuscularly challenged rainbow trout infection model. The mutagenesis approach developed in this work represents an improvement over the gene inactivation tools existing hitherto for this "fastidious" bacterium. Unlike transposon mutagenesis and gene disruption, gene markerless deletion has less potential for polar effects and allows the mutation of virtually any non-essential gene or gene clusters.

  5. Programmed cell death in Laminaria japonica (Phaeophyta) tissues infected with alginic acid decomposing bacterium

    Institute of Scientific and Technical Information of China (English)

    WANG Gaoge; LIN Wei; ZHANG Lijing; YAN Xiaojun; DUAN Delin

    2004-01-01

    TdT-mediated dUTP-biotin nick end labeling (TUNEL) is a sensitive and valid method for detecting DNA cleavage in programmed cell death (PCD). Using this method, DNA cleavage was observed in Laminaria japonica sporophytic tissues, which were infected with alginic acid decomposing bacterium. It was found that DNA cleavage occurred 5 min after the infection, the fragments with 3′-OH groups of cleaved nuclear DNA increased with time of infection and spread from the infection site. Although no typical DNA ladder (200 bp/180 bp) was detected by routine agarose gel electrophoresis, the cleavage of nuclear DNA fragments of 97~48.5 kb could be detected by pulsed field gel electrophoresis (PFGE). By using CaspGLOWTM fluorescein active caspase-3 staining method, caspase-3 activity has been detected in response to the infection of alginic acid decomposing bacterium. Our results are similar to the observations in hypersensitive response (HR) of higher plant, suggesting that the rapid cell death of L. Japonica infected by alginic acid decomposing bacterium might be involved in PCD, and indicating that the occurrence of PCD is an active defense process against the pathogen's infection.

  6. Phosphate enhances levan production in the endophytic bacterium Gluconacetobacter diazotrophicus Pal5

    Science.gov (United States)

    Idogawa, Nao; Amamoto, Ryuta; Murata, Kousaku; Kawai, Shigeyuki

    2014-01-01

    Gluconacetobacter diazotrophicus is a gram-negative and endophytic nitrogen-fixing bacterium that has several beneficial effects in host plants; thus, utilization of this bacterium as a biofertilizer in agriculture may be possible. G. diazotrophicus synthesizes levan, a D-fructofuranosyl polymer with β-(2→6) linkages, as an exopolysaccharide and the synthesized levan improves the stress tolerance of the bacterium. In this study, we found that phosphate enhances levan production by G. diazotrophicus Pal5, a wild type strain that showed a stronger mucous phenotype on solid medium containing 28 mM phosphate than on solid medium containing 7 mM phosphate. A G. diazotrophicus Pal5 levansucrase disruptant showed only a weak mucous phenotype regardless of the phosphate concentration, indicating that the mucous phenotype observed on 28 mM phosphate medium was caused by levan. To our knowledge, this is the first report of the effect of a high concentration of phosphate on exopolysaccharide production. PMID:24717418

  7. Anomalous magnetic orientations of magnetosome chains in a magnetotactic bacterium: Magnetovibrio blakemorei strain MV-1.

    Directory of Open Access Journals (Sweden)

    Samanbir S Kalirai

    Full Text Available There is a good deal of published evidence that indicates that all magnetosomes within a single cell of a magnetotactic bacterium are magnetically oriented in the same direction so that they form a single magnetic dipole believed to assist navigation of the cell to optimal environments for their growth and survival. Some cells of the cultured magnetotactic bacterium Magnetovibrio blakemorei strain MV-1 are known to have relatively wide gaps between groups of magnetosomes that do not seem to interfere with the larger, overall linear arrangement of the magnetosomes along the long axis of the cell. We determined the magnetic orientation of the magnetosomes in individual cells of this bacterium using Fe 2p X-ray magnetic circular dichroism (XMCD spectra measured with scanning transmission X-ray microscopy (STXM. We observed a significant number of cases in which there are sub-chains in a single cell, with spatial gaps between them, in which one or more sub-chains are magnetically polarized opposite to other sub-chains in the same cell. These occur with an estimated frequency of 4.0±0.2%, based on a sample size of 150 cells. We propose possible explanations for these anomalous cases which shed insight into the mechanisms of chain formation and magnetic alignment.

  8. An oleaginous bacterium that intrinsically accumulates long-chain free Fatty acids in its cytoplasm.

    Science.gov (United States)

    Katayama, Taiki; Kanno, Manabu; Morita, Naoki; Hori, Tomoyuki; Narihiro, Takashi; Mitani, Yasuo; Kamagata, Yoichi

    2014-02-01

    Medium- and long-chain fatty acids are present in organisms in esterified forms that serve as cell membrane constituents and storage compounds. A large number of organisms are known to accumulate lipophilic materials as a source of energy and carbon. We found a bacterium, designated GK12, that intrinsically accumulates free fatty acids (FFAs) as intracellular droplets without exhibiting cytotoxicity. GK12 is an obligatory anaerobic, mesophilic lactic acid bacterium that was isolated from a methanogenic reactor. Phylogenetic analysis based on 16S rRNA gene sequences showed that GK12 is affiliated with the family Erysipelotrichaceae in the phylum Firmicutes but is distantly related to type species in this family (less than 92% similarity in 16S rRNA gene sequence). Saturated fatty acids with carbon chain lengths of 14, 16, 18, and 20 were produced from glucose under stress conditions, including higher-than-optimum temperatures and the presence of organic solvents that affect cell membrane integrity. FFAs were produced at levels corresponding to up to 25% (wt/wt) of the dry cell mass. Our data suggest that FFA accumulation is a result of an imbalance between excess membrane fatty acid biosynthesis due to homeoviscous adaptation and limited β-oxidation activity due to anaerobic growth involving lactic acid fermentation. FFA droplets were not further utilized as an energy and carbon source, even under conditions of starvation. A naturally occurring bacterium that accumulates significant amounts of long-chain FFAs with noncytotoxicity would provide useful strategies for microbial biodiesel production.

  9. Comparative proteomics and activity of a green sulfur bacterium across the water column of Lake Cadagno, Switzerland

    DEFF Research Database (Denmark)

    Habicht, Kirsten Silvia; Miller, Mette; Cox, Raymond Pickett

    2011-01-01

    Primary production in the meromictic Lake Cadagno, Switzerland, is dominated by anoxygenic photosynthesis. The green sulfur bacterium Chlorobium clathratiforme is the dominant phototrophic organism in the lake, comprising more than half of the bacterial population, and its biomass increases 3...

  10. Genome Sequence of the Endophytic Bacterium Bacillus thuringiensis Strain KB1, a Potential Biocontrol Agent against Phytopathogens

    OpenAIRE

    Jeong, Haeyoung; Jo, Sung Hee; Hong, Chi Eun; Park, Jeong Mee

    2016-01-01

    Bacillus thuringiensis is the most widely known microbial pesticide used in agricultural applications. Herein, we report a draft genome sequence of the endophytic bacterium Bacillus thuringiensis strain KB1, which exhibits antagonism against phytopathogens.

  11. Genome Sequence of the Endophytic Bacterium Bacillus thuringiensis Strain KB1, a Potential Biocontrol Agent against Phytopathogens.

    Science.gov (United States)

    Jeong, Haeyoung; Jo, Sung Hee; Hong, Chi Eun; Park, Jeong Mee

    2016-04-21

    ITALIC! Bacillus thuringiensisis the most widely known microbial pesticide used in agricultural applications. Herein, we report a draft genome sequence of the endophytic bacterium ITALIC! Bacillus thuringiensisstrain KB1, which exhibits antagonism against phytopathogens.

  12. Regulatory effect of the typical methyl-group donors on the oxygen metabolism in Pseudomonas denitrificans%典型性甲基供体对脱氮假单胞杆菌代谢过程的氧调控作用

    Institute of Scientific and Technical Information of China (English)

    周佳; 程新; 彭志远; 彭卫福; 李昆太

    2013-01-01

    In this paper,the fermentation processes of Pseudomonas denitrificans were investigated in 7L fermenter by using betaine and choline chloride as the typical methyl - group donors for vitamin B12 biosynthesis, respectively. When using choline chloride as the methyl - group donor, the dissolved oxygen ( DO) and pH respectively presented an obviously zooming and dropping phenomena, resulting in a slow cell growth and low vitamin B12 biosynthesis.However,the metabolism capability under betaine as methyl-group donor was significantly better than that of choline chloride, and the pH and DO could be maintained at a stable and appropriate level during the whole fermentation processes. As a result, the final cell growth and vitamin B12 production were significantly higher than those obtained in choline chloride.%本文在7L发酵罐中分别以甜菜碱和氯化胆碱作为合成维生素B12的甲基供体,分别考察了二者对脱氮假单胞杆菌代谢过程的影响.结果表明:使用氯化胆碱的罐批出现了溶氧过早回升、pH剧烈下降等异常的代谢现象,致使发酵过程的菌体生长缓慢且维生素B12合成量低;而使用甜菜碱作为甲基供体时,其菌体代谢活力要明显优于使用氯化胆碱的罐批,整个发酵过程的pH和溶氧均能保持在稳定且合适的水平,最终的菌体量和维生素B12产量也更高.

  13. Photoproduction of hydrogen by a non-sulphur bacterium isolated from root zones of water fern Azolla pinnata

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S.P.; Srivastava, S.C.; Pandey, K.D. (Banaras Hindu Univ., Varanasi (IN). Centre of Advanced Study in Botany)

    1990-01-01

    A photosynthetic bacterium Rhodopseudomonas sp. BHU strain 1 was isolated from the root zone of water fern Azolla pinnata. The bacterium was found to produce hydrogen with potato starch under phototrophic conditions. The immobilized bacterial cells showed sustained hydrogen production with a more than 4-fold difference over free cell suspensions. The data have been discussed in the light of possible utilization of relatively cheaper raw materials by non-sulphur bacteria to evolve hydrogen. (author).

  14. Features of a Clostridium, strain CV-AA1, an obligatory anaerobic bacterium producing acetic acid from methanol.

    Science.gov (United States)

    Adamse, A D; Velzeboer, C T

    1982-01-01

    Isolation and characterization of a new, obligatory, anaerobic, methylotrophic, homoacetogenic bacterium is described. This bacterium is a mesophilic, motile, slightly curved rod that demonstrated a negative Gram reaction, formed spherical, (sub)terminal spores and performed a homoacetic fermentation with methanol, a CO2-2H2-gas mixture, glucose or fructose, respectively, as the substrate. The methanol fermentation proceeded only when a suitable amount of NaHCO3 was available in the nutrient solution supplied.

  15. Alcanivorax dieselolei, an alkane-degrading bacterium associated with the mucus of the zoanthid Palythoa caribaeorum (Cnidaria, Anthozoa

    Directory of Open Access Journals (Sweden)

    FF. Campos

    Full Text Available Analyses of 16S rDNA genes were used to identify the microbiota isolated from the mucus of the zoanthid Palythoa caribaeorum at Porto de Galinhas on the coast of Pernambuco State, Brazil. This study is important as the first report of this association, because of the potential biotechnological applications of the bacterium Alcanivorax dieselolei, and as evidence for the presence of a hydrocarbon degrading bacterium in a reef ecosystem such as Porto de Galinhas.

  16. A Literature Review of the Bacterium Klebsiella spp.: Grays Harbor and Chehalis River Improvements to Navigation Environmental Studies,

    Science.gov (United States)

    1981-04-01

    Taxonomy of Klebsiella pneumoniae isolated from pulp/paper mill wastewater . Environmental Protection Agency, 660/2-75-024. Knittel, M. D. 1975...AD-AI 263 CORPS OF ENGINEERS SEATTLE WASH SEATTLE DISTRICT F/6 13/2 L.ITERATURE REVIEW OF THE BACTERIUM KLEBSIELLA SPP.I BRAYS HAR--ETC(Ul...UNCLASSIFIED N Ehhmmmhhh TA GRAYS HARBOR AND CHEHALIS RIVER IMPROVEMENTS TO NAVIGATIO ENVIRONMENTAL STUDIES A LITERATURE REVIEW OF THE BACTERIUM KLEBSIELLA SPP

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

    Science.gov (United States)

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

    2015-10-01

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

  18. Comparative genome analysis of Pseudomonas knackmussii B13, the first bacterium known to degrade chloroaromatic compounds.

    Science.gov (United States)

    Miyazaki, Ryo; Bertelli, Claire; Benaglio, Paola; Canton, Jonas; De Coi, Nicoló; Gharib, Walid H; Gjoksi, Bebeka; Goesmann, Alexander; Greub, Gilbert; Harshman, Keith; Linke, Burkhard; Mikulic, Josip; Mueller, Linda; Nicolas, Damien; Robinson-Rechavi, Marc; Rivolta, Carlo; Roggo, Clémence; Roy, Shantanu; Sentchilo, Vladimir; Siebenthal, Alexandra Von; Falquet, Laurent; van der Meer, Jan Roelof

    2015-01-01

    Pseudomonas knackmussii B13 was the first strain to be isolated in 1974 that could degrade chlorinated aromatic hydrocarbons. This discovery was the prologue for subsequent characterization of numerous bacterial metabolic pathways, for genetic and biochemical studies, and which spurred ideas for pollutant bioremediation. In this study, we determined the complete genome sequence of B13 using next generation sequencing technologies and optical mapping. Genome annotation indicated that B13 has a variety of metabolic pathways for degrading monoaromatic hydrocarbons including chlorobenzoate, aminophenol, anthranilate and hydroxyquinol, but not polyaromatic compounds. Comparative genome analysis revealed that B13 is closest to Pseudomonas denitrificans and Pseudomonas aeruginosa. The B13 genome contains at least eight genomic islands [prophages and integrative conjugative elements (ICEs)], which were absent in closely related pseudomonads. We confirm that two ICEs are identical copies of the 103 kb self-transmissible element ICEclc that carries the genes for chlorocatechol metabolism. Comparison of ICEclc showed that it is composed of a variable and a 'core' region, which is very conserved among proteobacterial genomes, suggesting a widely distributed family of so far uncharacterized ICE. Resequencing of two spontaneous B13 mutants revealed a number of single nucleotide substitutions, as well as excision of a large 220 kb region and a prophage that drastically change the host metabolic capacity and survivability.

  19. High Prevalence of Antibodies against the Bacterium Treponema pallidum in Senegalese Guinea Baboons (Papio papio).

    Science.gov (United States)

    Knauf, Sascha; Barnett, Ulrike; Maciej, Peter; Klapproth, Matthias; Ndao, Ibrahima; Frischmann, Sieghard; Fischer, Julia; Zinner, Dietmar; Liu, Hsi

    2015-01-01

    The bacterium Treponema pallidum is known to cause syphilis (ssp. pallidum), yaws (ssp. pertenue), and endemic syphilis (ssp. endemicum) in humans. Nonhuman primates have also been reported to be infected with the bacterium with equally versatile clinical manifestations, from severe skin ulcerations to asymptomatic. At present all simian strains are closely related to human yaws-causing strains, an important consideration for yaws eradication. We tested clinically healthy Guinea baboons (Papio papio) at Parc National Niokolo Koba in south eastern Senegal for the presence of anti-T. pallidum antibodies. Since T. pallidum infection in this species was identified 50 years ago, and there has been no attempt to treat non-human primates for infection, it was hypothesized that a large number of West African baboons are still infected with simian strains of the yaws-bacterium. All animals were without clinical signs of treponematoses, but 18 of 20 (90%) baboons tested positive for antibodies against T. pallidum based on treponemal tests. Yet, Guinea baboons seem to develop no clinical symptoms, though it must be assumed that infection is chronic or comparable to the latent stage in human yaws infection. The non-active character is supported by the low anti-T. pallidum serum titers in Guinea baboons (median = 1:2,560) versus serum titers that are found in genital-ulcerated olive baboons with active infection in Tanzania (range of medians among the groups of initial, moderate, and severe infected animals = 1:15,360 to 1:2.097e+7). Our findings provide evidence for simian infection with T. pallidum in wild Senegalese baboons. Potentially, Guinea baboons in West Africa serve as a natural reservoir for human infection, as the West African simian strain has been shown to cause sustainable yaws infection when inoculated into humans. The present study pinpoints an area where further research is needed to support the currently on-going second WHO led yaws eradication campaign with

  20. Cloning and characterization of nif structural and regulatory genes in the purple sulfur bacterium, Halorhodospira halophila.

    Science.gov (United States)

    Tsuihiji, Hisayoshi; Yamazaki, Yoichi; Kamikubo, Hironari; Imamoto, Yasushi; Kataoka, Mikio

    2006-03-01

    Halorhodospira halophila is a halophilic photosynthetic bacterium classified as a purple sulfur bacterium. We found that H. halophila generates hydrogen gas during photoautotrophic growth as a byproduct of a nitrogenase reaction. In order to consider the applied possibilities of this photobiological hydrogen generation, we cloned and characterized the structural and regulatory genes encoding the nitrogenase, nifH, nifD and nifA, from H. halophila. This is the first description of the nif genes for a purple sulfur bacterium. The amino-acid sequences of NifH and NifD indicated that these proteins are an Fe protein and a part of a MoFe protein, respectively. The important residues are conserved completely. The sequence upstream from the nifH region and sequence similarities of nifH and nifD with those of the other organisms suggest that the regulatory system might be a NifL-NifA system; however, H. halophila lacks nifL. The amino-acid sequence of H. halophila NifA is closer to that of the NifA of the NifL-NifA system than to that of NifA without NifL. H. halophila NifA does not conserve either the residue that interacts with NifL or the important residues involved in NifL-independent regulation. These results suggest the existence of yet another regulatory system, and that the development of functional systems and their molecular counterparts are not necessarily correlated throughout evolution. All of these Nif proteins of H. halophila possess an excess of acidic residues, which acts as a salt-resistant mechanism.

  1. Whole genome shotgun sequence of Bacillus amyloliquefaciens TF28, a biocontrol entophytic bacterium.

    Science.gov (United States)

    Zhang, Shumei; Jiang, Wei; Li, Jing; Meng, Liqiang; Cao, Xu; Hu, Jihua; Liu, Yushuai; Chen, Jingyu; Sha, Changqing

    2016-01-01

    Bacillus amyloliquefaciens TF28 is a biocontrol endophytic bacterium that is capable of inhibition of a broad range of plant pathogenic fungi. The strain has the potential to be developed into a biocontrol agent for use in agriculture. Here we report the whole-genome shotgun sequence of the strain. The genome size of B. amyloliquefaciens TF28 is 3,987,635 bp which consists of 3754 protein-coding genes, 65 tandem repeat sequences, 47 minisatellite DNA, 2 microsatellite DNA, 63 tRNA, 7rRNA, 6 sRNA, 3 prophage and CRISPR domains.

  2. Asticcacaulis benevestitus sp. nov., a psychrotolerant, dimorphic, prosthecate bacterium from tundra wetland soil.

    OpenAIRE

    Vasilyeva, Lina V; Omelchenko, Marina V.; Berestovskaya, Yulia Y; Lysenko, Anatolii M; Abraham, Wolf-Rainer; Dedysh, Svetlana N.; Zavarzin, George A

    2006-01-01

    A Gram-negative, aerobic, heterotrophic, non-pigmented, dimorphic prosthecate bacterium was isolated from tundra wetland soil and designated strain Z-0023(T). Cells of this strain had a dimorphic life cycle and developed a non-adhesive stalk at a site not coincident with the centre of the cell pole, a characteristic typical of representatives of the genus Asticcacaulis. A highly distinctive feature of cells of strain Z-0023(T) was the presence of a conical, bell-shaped sheath when grown at lo...

  3. Exoelectrogenic bacterium phylogenetically related to Citrobacter freundii, isolated from anodic biofilm of a microbial fuel cell.

    Science.gov (United States)

    Huang, Jianjian; Zhu, Nengwu; Cao, Yanlan; Peng, Yue; Wu, Pingxiao; Dong, Wenhao

    2015-02-01

    An electrogenic bacterium, named Citrobacter freundii Z7, was isolated from the anodic biofilm of microbial fuel cell (MFC) inoculated with aerobic sewage sludge. Cyclic voltammetry (CV) analysis exhibited that the strain Z7 had relatively high electrochemical activity. When the strain Z7 was inoculated into MFC, the maximum power density can reach 204.5 mW/m(2) using citrate as electron donor. Series of substrates including glucose, glycerol, lactose, sucrose, and rhammose could be utilized to generate power. CV tests and the addition of anode solution as well as AQDS experiments indicated that the strain Z7 might transfer electrons indirectly via secreted mediators.

  4. A high-performance metal-free hydrogen-evolution reaction electrocatalyst from bacterium derived carbon

    OpenAIRE

    2015-01-01

    We report a sustainable approach to obtain carbon materials with nitrogen and phosphorus dual functionalities from a common bacterium strain (S. aureus) as a highly efficient hydrogen-evolution reaction (HER) catalyst. With mesoporous structure introduced by ZnCl2 salt and cathodic activation, it demonstrates an onset overpotential as low as 76 mV, a Tafel slope of 58.4 mV dec(-1) and a large normalized exchange current density of 1.72 x 10(-2) mA cm(-2), which are comparable to those of hith...

  5. Cloning, sequencing, and sequence analysis of two novel plasmids from the thermophilic anaerobic bacterium Anaerocellum thermophilum

    DEFF Research Database (Denmark)

    Clausen, Anders; Mikkelsen, Marie Just; Schrøder, I.

    2004-01-01

    The nucleotide sequence of two novel plasmids isolated from the extreme thermophilic anaerobic bacterium Anaerocellum thermophilum DSM6725 (A. thermophilum), growing optimally at 70degreesC, has been determined. pBAS2 was found to be a 3653 bp plasmid with a GC content of 43%, and the sequence...... was found, but no single stranded intermediates, characteristic of rolling circle replication, were found on Southern blots. The larger plasmid, pBAL, was found to be a 8294 bp plasmid with a GC content of 39%. It revealed 17 ORFs, of which three showed similarity at the amino acid (aa) level to known...

  6. Co-metabolism of DDT by the newly isolated bacterium, Pseudoxanthomonas sp. wax

    OpenAIRE

    2010-01-01

    Microbial degradation of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) is the most promising way to clean up DDT residues found in the environment. In this paper, a bacterium designated as wax, which was capable of co-metabolizing DDT with other carbon sources, was isolated from a long-term DDT-contaminated soil sample by an enrichment culture technique. The new isolate was identified as a member of the Pseudoxanthomonas sp., based on its morphological, physiological and biochemical pro...

  7. Uncoupling effect of fatty acids in halo- and alkalotolerant bacterium Bacillus pseudofirmus FTU.

    Science.gov (United States)

    Popova, I V; Bodrova, M E; Mokhova, E N; Muntyan, M S

    2004-10-01

    Natural uncouplers of oxidative phosphorylation, long-chain non-esterified fatty acids, cause uncoupling in the alkalo- and halotolerant bacterium Bacillus pseudofirmus FTU. The uncoupling effect in the bacterial cells was manifested as decrease of membrane potential and increase of respiratory activity. The membrane potential decrease was detected only in bacterial cells exhausted by their endogenous substrates. In proteoliposomes containing reconstituted bacterial cytochrome c oxidase, fatty acids caused a "mild" uncoupling effect by reducing membrane potential only at low rate of membrane potential generation. "Free respiration" induced by the "mild" uncouplers, the fatty acids, can be considered as possible mechanism responsible for adaptation of the bacteria to a constantly changed environment.

  8. Response to Comments on "A Bacterium That Can Grow Using Arsenic Instead of Phosphorus"

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe-Simon, F; Blum, J S; Kulp, T R; Gordon, G W; Hoeft, S E; Pett-Ridge, J; Stolz, J F; Webb, S M; Weber, P K; Davies, P W; Anbar, A D; Oremland, R S

    2011-03-07

    Concerns have been raised about our recent study describing a bacterium that can grow using arsenic (As) instead of phosphorus (P). Our data suggested that As could act as a substitute for P in major biomolecules in this organism. Although the issues raised are of investigative interest, we contend that they do not invalidate our conclusions. We argue that while no single line of evidence we presented was sufficient to support our interpretation of the data, taken as an entire dataset we find no plausible alternative to our conclusions. Here we reply to the critiques and provide additional arguments supporting the assessment of the data we reported.

  9. Dynamic detection of a single bacterium: nonlinear rotation rate shifts of driven magnetic microsphere stages

    CERN Document Server

    McNaughton, B H; Kopelman, R; Agayan, Rodney R.; Kopelman, Raoul; Naughton, Brandon H. Mc

    2006-01-01

    We report on a new technique which was used to detect single Escherichia coli that is based on the changes in the nonlinear rotation of a magnetic microsphere driven by an external magnetic field. The presence of one Escherichia Coli bacterium on the surface of a 2.0 micron magnetic microsphere caused an easily measurable change in the drag of the system and, therefore, in the nonlinear rotation rate. The straight-forward measurement uses standard microscopy techniques and the observed average shift in the nonlinear rotation rate changed by a factor of ~3.8.

  10. Isolation and identification of a novel alginate-degrading bacterium, Ochrobactrum sp.

    Directory of Open Access Journals (Sweden)

    Xiao-wei Zhao

    2008-03-01

    Full Text Available An alginate-degrading bacterium, identified as Ochrobactrum sp. on the basis of 16S rDNA gene sequencing, was isolated from brown algal samples collected from the waters in close vicinity to the Dongtou Isles in the East China Sea. The strain, designated WZUH09-1, is a short rod, gram-negative, obligatory aerobic, grows under the following conditions: 5-40oC, pH 3-9, and 0-2 times of the seawater concentration, and is able to depolymerize alginates with higher enzyme activity than that of others reported so far.

  11. FACTORS LIMITING BACTERIAL GROWTH : III. CELL SIZE AND "PHYSIOLOGIC YOUTH" IN BACTERIUM COLI CULTURES.

    Science.gov (United States)

    Hershey, A D; Bronfenbrenner, J

    1938-07-20

    1. Measurements of the rate of oxygen uptake per cell in transplants of Bacterium coli from cultures of this organism in different phases of growth have given results in essential agreement with the observations of others. 2. Correlations of viable count, centrifugable nitrogen, and turbidity, with oxygen consumption, indicate that the increased metabolism during the early portion of the growth period is quantitatively referable to increased average size of cells. 3. Indirect evidence has suggested that the initial rate of growth of transplants is not related to the phase of growth of the parent culture.

  12. Complete genome sequence of Enterobacter cloacae GGT036: a furfural tolerant soil bacterium.

    Science.gov (United States)

    Gong, Gyeongtaek; Um, Youngsoon; Park, Tai Hyun; Woo, Han Min

    2015-01-10

    Enterobacter cloacae is a facultative anaerobic bacterium to be an important cause of nosocomial infection. However, the isolated E. cloacae GGT036 showed higher furfural-tolerant cellular growth, compared to industrial relevant strains such as Escherichia coli and Corynebacterium glutamicum. Here, we report the complete genome sequence of E. cloacae GGT036 isolated from Mt. Gwanak, Seoul, Republic of Korea. The genomic DNA sequence of E. cloacae GGT036 will provide valuable genetic resources for engineering of industrially relevant strains being tolerant to cellular inhibitors present in lignocellulosic hydrolysates.

  13. Aggregation of the rhizospheric bacterium Azospirillum brasilense in response to oxygen

    Science.gov (United States)

    Abdoun, Hamid; McMillan, Mary; Pereg, Lily

    2016-04-01

    Azospirillum brasilense spp. have ecological, scientific and agricultural importance. As model plant growth promoting rhizobacteria they interact with a large variety of plants, including important food and cash crops. Azospirillum strains are known for their production of plant growth hormones that enhance root systems and for their ability to fix nitrogen. Azospirillum cells transform in response to environmental cues. The production of exopolysaccharides and cell aggregation during cellular transformation are important steps in the attachment of Azospirillum to roots. We investigate signals that induce cellular transformation and aggregation in the Azospirillum and report on the importance of oxygen to the process of aggregation in this rhizospheric bacterium.

  14. A bacterium that can grow by using arsenic instead of phosphorus

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe-Simon, F; Blum, J S; Kulp, T R; Gordon, G W; Hoeft, S E; Pett-Ridge, J; Stolz, J F; Webb, S M; Weber, P K; Davies, P W; Anbar, A D; Oremland, R S

    2010-11-01

    Life is mostly composed of the elements carbon, hydrogen, nitrogen, oxygen, sulfur and phosphorus. Although these six elements make up nucleic acids, proteins and lipids and thus the bulk of living matter, it is theoretically possible that some other elements in the periodic table could serve the same functions. Here we describe a bacterium, strain GFAJ-1 of the Halomonadaceae, isolated from Mono Lake, CA, which substitutes arsenic for phosphorus to sustain its growth. Our data show evidence for arsenate in macromolecules that normally contain phosphate, most notably nucleic acids and proteins. Exchange of one of the major bio-elements may have profound evolutionary and geochemical significance.

  15. A bacterium that can grow by using arsenic instead of phosphorus.

    Science.gov (United States)

    Wolfe-Simon, Felisa; Switzer Blum, Jodi; Kulp, Thomas R; Gordon, Gwyneth W; Hoeft, Shelley E; Pett-Ridge, Jennifer; Stolz, John F; Webb, Samuel M; Weber, Peter K; Davies, Paul C W; Anbar, Ariel D; Oremland, Ronald S

    2011-06-03

    Life is mostly composed of the elements carbon, hydrogen, nitrogen, oxygen, sulfur, and phosphorus. Although these six elements make up nucleic acids, proteins, and lipids and thus the bulk of living matter, it is theoretically possible that some other elements in the periodic table could serve the same functions. Here, we describe a bacterium, strain GFAJ-1 of the Halomonadaceae, isolated from Mono Lake, California, that is able to substitute arsenic for phosphorus to sustain its growth. Our data show evidence for arsenate in macromolecules that normally contain phosphate, most notably nucleic acids and proteins. Exchange of one of the major bio-elements may have profound evolutionary and geochemical importance.

  16. Draft Genome Sequence of the Endophytic Strain Rhodococcus kyotonensis KB10, a Potential Biodegrading and Antibacterial Bacterium Isolated from Arabidopsis thaliana

    Science.gov (United States)

    Hong, Chi Eun; Jo, Sung Hee

    2016-01-01

    Rhodococcus kyotonensis KB10 is an endophytic bacterium isolated from Arabidopsis thaliana. The organism showed mild antibacterial activity against the phytopathogen Pseudomonas syringae pv. tomato DC3000. This study reports the genome sequence of R. kyotonensis KB10. This bacterium contains an ectoine biosynthesis gene cluster and has the potential to degrade nitroaromatic compounds. The identified bacterium may be a suitable biocontrol agent and degrader of environmental pollutants. PMID:27389269

  17. Non-specific immune response of bullfrog Rana catesbeiana to intraperitoneal injection of bacterium Aeromonas hydrophila

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Non-specific immune response of bullfrog Rana catesbeiana to pathogenic Aeromonas hydrophila was studied to 60 individuals in two groups. Each bullfrog in bacterium-injected group was injected intraperitoneally (i.p.) with 0.2 ml bacterial suspension at a density of 5.2 × 106 CFU/ml, while each one in control group injected i.p. with 0.2 ml sterile saline solution (0.85%, w/v). Three bullfrogs in both groups were sampled at 0, 1, 3, 7, 11, 15 and 20 days post-injection (dpi) for the evaluation of non-specific immune parameters. It was observed that intraperitoneal injection of A. hydrophila significantly increased the number of leucocytes and that of NBT-positive cells in peripheral blood. Significant increases in serum bactericidal activity and serum acid phosphatase activity were also observed in the bacterium-injected frogs when compared with those in the control group. However, a significant reduction was detected in vitro in phagocytosis activity of peripheral blood phagocytes. No significant difference in changes in the number of peripheral erythrocytes, serum superoxide dismutase (SOD) activity, and lysozyme activity was detected between the two groups. It is suggested that bullfrogs may produce a series of non-specific immune reactions in response to the A. hydrophila infection.

  18. Production and characterization of bioemulsifier from a marine bacterium, Acinetobacter calcoaceticus subsp. anitratus SM7

    Directory of Open Access Journals (Sweden)

    Kulnaree Phetrong

    2008-05-01

    Full Text Available Marine bacterium strain SM7 was isolated as a bioemulsifier-producing bacterium from oil-spilled seawater in Songkhla lagoon, Thailand. It was identified as Acinetobacter calcoaceticus subsp. anitratus based on morphology, biochemicalcharacteristics and 16S rRNA sequence. A. calcoaceticus subsp. anitratus SM7 produced an extracellular emulsifying agent when grown in a minimal salt medium (pH 7.0 containing 0.3% (v/v n-heptadecane and 0.1% (w/v ammoniumhydrogen carbonate as carbon source and nitrogen source, respectively, at 30oC with agitation rate of 200 rpm. Crude bioemulsifier was recovered from the culture supernatant by ethanol precipitation with a yield of 2.94 g/l and had a criticalemulsifier concentration of 0.04 g/ml. The crude bioemulsifier was capable of emulsifying n-hexadecane in a broad pH range (6-12, temperatures (30-121oC and in the presence of NaCl up to 12% (w/v. The bioemulsifier was stable in saltsolution ranging from 0 to 0.1% (w/v of MgCl2 and CaCl2. The broad range of pH stability, thermostability and salt tolerance suggested that the bioemulsifier from A. calcoaceticus subsp. anitratus SM7 could be useful in environmentalapplication, especially bioremediation of oil-polluted seawater.

  19. The Symbiotic Bacterium Fuels the Energy Metabolism of the Host Trypanosomatid Strigomonas culicis.

    Science.gov (United States)

    Loyola-Machado, Ana Carolina; Azevedo-Martins, Allan Cézar; Catta-Preta, Carolina Moura Costa; de Souza, Wanderley; Galina, Antonio; Motta, Maria Cristina M

    2017-02-28

    The mutualistic relationship between trypanosomatids and their respective endosymbiotic bacteria represents an excellent model for studying metabolic co-evolution since the symbiont completes essential biosynthetic routes of the host cell. In this work, we investigated the influence of the endosymbiont on the energy metabolism of Strigomonas culicis by comparing the wild strain with aposymbiotic protists. The bacterium maintains a frequent and close association with glycosomes, which are distributed around the prokaryote. Furthermore, 3D reconstructions revealed that the shape and distribution of glycosomes are different in symbiont-bearing protists compared to symbiont-free cells. Results of bioenergetic assays showed that the presence of the symbiont enhances the O2 consumption of the host cell. When the quantity of intracellular or released glycerol was evaluated, the aposymbiotic strain presented higher values when compared to symbiont-containing cells. Furthermore, inhibition of oxidative phosphorylation by potassium cyanide increased the rate of glycerol release and slightly diminished the ATP content in cells without the symbiont, indicating that the host trypanosomatid enhances its fermentative activity when the bacterium is lost.

  20. (Per)chlorate reduction by an acetogenic bacterium, Sporomusa sp., isolated from an underground gas storage.

    KAUST Repository

    Balk, Melike

    2010-08-03

    A mesophilic bacterium, strain An4, was isolated from an underground gas storage reservoir with methanol as substrate and perchlorate as electron acceptor. Cells were Gram-negative, spore-forming, straight to curved rods, 0.5-0.8 microm in diameter, and 2-8 microm in length, growing as single cells or in pairs. The cells grew optimally at 37 degrees C, and the pH optimum was around 7. Strain An4 converted various alcohols, organic acids, fructose, acetoin, and H(2)/CO(2) to acetate, usually as the only product. Succinate was decarboxylated to propionate. The isolate was able to respire with (per)chlorate, nitrate, and CO(2). The G+C content of the DNA was 42.6 mol%. Based on the 16S rRNA gene sequence analysis, strain An4 was most closely related to Sporomusa ovata (98% similarity). The bacterium reduced perchlorate and chlorate completely to chloride. Key enzymes, perchlorate reductase and chlorite dismutase, were detected in cell-free extracts.

  1. Asticcacaulis benevestitus sp. nov., a psychrotolerant, dimorphic, prosthecate bacterium from tundra wetland soil.

    Science.gov (United States)

    Vasilyeva, Lina V; Omelchenko, Marina V; Berestovskaya, Yulia Y; Lysenko, Anatolii M; Abraham, Wolf-Rainer; Dedysh, Svetlana N; Zavarzin, George A

    2006-09-01

    A Gram-negative, aerobic, heterotrophic, non-pigmented, dimorphic prosthecate bacterium was isolated from tundra wetland soil and designated strain Z-0023(T). Cells of this strain had a dimorphic life cycle and developed a non-adhesive stalk at a site not coincident with the centre of the cell pole, a characteristic typical of representatives of the genus Asticcacaulis. A highly distinctive feature of cells of strain Z-0023(T) was the presence of a conical, bell-shaped sheath when grown at low temperature. This prosthecate bacterium was a psychrotolerant, moderately acidophilic organism capable of growth between 4 and 28 degrees Celsius (optimum 15-20 degrees Celsius) and between pH 4.5 and 8.0 (optimum 5.6-6.0). The major phospholipid fatty acid was 18 : 1omega7c and the major phospholipids were phosphatidylglycerols. The G+C content of the DNA was 60.4 mol%. On the basis of 16S rRNA gene sequence similarity, strain Z-0023(T) was most closely related to Asticcacaulis biprosthecium (98 % similarity), Asticcacaulis taihuensis (98 %) and Asticcacaulis excentricus (95 %). However, low levels of DNA-DNA relatedness to these organisms and a number of distinctive features of the tundra wetland isolate indicated that it represented a novel species of the genus Asticcacaulis, for which the name Asticcacaulis benevestitus sp. nov. is proposed. The type strain is Z-0023(T) (=DSM 16100(T)=ATCC BAA-896(T)).

  2. Biogenesis of antibacterial silver nanoparticles using the endophytic bacterium Bacillus cereus isolated from Garcinia xanthochymus

    Institute of Scientific and Technical Information of China (English)

    Swetha Sunkar; C Valli Nachiyar

    2012-01-01

    Objective:To synthesize the ecofriendly nanoparticles, which is viewed as an alternative to the chemical method which initiated the use of microbes like bacteria and fungi in their synthesis. Methods: The current study uses the endophytic bacterium Bacillus cereus isolated from the Garcinia xanthochymus to synthesize the silver nanoparticles (AgNPs). The AgNPs were synthesized by reduction of silver nitrate solution by the endophytic bacterium after incubation for 3-5 d at room temperature. The synthesis was initially observed by colour change from pale white to brown which was confirmed by UV-Vis spectroscopy. The AgNPs were further characterized using FTIR, SEM-EDX and TEM analyses. Results:The synthesized nanoparticles were found to be spherical with the size in the range of 20-40 nm which showed a slight aggregation. The energy-dispersive spectra of the nanoparticle dispersion confirmed the presence of elemental silver. The AgNPs were found to have antibacterial activity against a few pathogenic bacteria like Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi and Klebsiella pneumoniae. Conclusions:The endophytic bacteria identified as Bacillus cereus was able to synthesize silver nanoparticles with potential antibacterial activity.

  3. Quorum sensing activity of Citrobacter amalonaticus L8A, a bacterium isolated from dental plaque.

    Science.gov (United States)

    Goh, Share-Yuan; Khan, Saad Ahmed; Tee, Kok Keng; Abu Kasim, Noor Hayaty; Yin, Wai-Fong; Chan, Kok-Gan

    2016-02-10

    Cell-cell communication is also known as quorum sensing (QS) that happens in the bacterial cells with the aim to regulate their genes expression in response to increased cell density. In this study, a bacterium (L8A) isolated from dental plaque biofilm was identified as Citrobacter amalonaticus by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). Its N-acylhomoserine-lactone (AHL) production was screened by using two types of AHL biosensors namely Chromobacterium violaceum CV026 and Escherichia coli [pSB401]. Citrobacter amalonaticus strain L8A was identified and confirmed producing numerous types of AHL namely N-butyryl-L-homoserine lactone (C4-HSL), N-hexanoyl-L-homoserine lactone (C6-HSL), N-octanoyl-L-homoserine lactone (C8-HSL) and N-hexadecanoyl-L-homoserine lactone (C16-HSL). We performed the whole genome sequence analysis of this oral isolate where its genome sequence reveals the presence of QS signal synthase gene and our work will pave the ways to study the function of the related QS genes in this bacterium.

  4. Nitrite-Oxidizing Bacterium Nitrobacter winogradskyi Produces N-Acyl-Homoserine Lactone Autoinducers.

    Science.gov (United States)

    Mellbye, Brett L; Bottomley, Peter J; Sayavedra-Soto, Luis A

    2015-09-01

    Nitrobacter winogradskyi is a chemolithotrophic bacterium that plays a role in the nitrogen cycle by oxidizing nitrite to nitrate. Here, we demonstrate a functional N-acyl-homoserine lactone (acyl-HSL) synthase in this bacterium. The N. winogradskyi genome contains genes encoding a putative acyl-HSL autoinducer synthase (nwi0626, nwiI) and a putative acyl-HSL autoinducer receptor (nwi0627, nwiR) with amino acid sequences 38 to 78% identical to those in Rhodopseudomonas palustris and other Rhizobiales. Expression of nwiI and nwiR correlated with acyl-HSL production during culture. N. winogradskyi produces two distinct acyl-HSLs, N-decanoyl-l-homoserine lactone (C10-HSL) and a monounsaturated acyl-HSL (C10:1-HSL), in a cell-density- and growth phase-dependent manner, during batch and chemostat culture. The acyl-HSLs were detected by bioassay and identified by ultraperformance liquid chromatography with information-dependent acquisition mass spectrometry (UPLC-IDA-MS). The C=C bond in C10:1-HSL was confirmed by conversion into bromohydrin and detection by UPLC-IDA-MS.

  5. Enzymatic properties of chitinase-producing antagonistic bacterium Paenibacillus chitinolyticus with various substrates.

    Science.gov (United States)

    Song, Yong-Su; Seo, Dong-Jun; Ju, Wan-Taek; Lee, Yong-Seong; Jung, Woo-Jin

    2015-12-01

    Various chitin substrates were used to investigate the properties of enzymes produced from the chitinase-producing bacterium Paenibacillus chitinolyticus MP-306 against phytopathogens. The MP-306 bacterium was incubated in nine culture media [crab shell powder chitin (CRS), chitin-protein complex powder (CPC), carboxymethyl-chitin powder (CMC), yeast extract only (YE), LB (Trypton, NaCl, and yeast extract), GT (Trypton, NaCl, and glucose), crab shell colloidal chitin (CSC), squid pen powder chitin (SPC), and cicada slough powder chitin (CSP)] at 30 °C for 3 days. Chitinase isozymes in CPC medium were expressed strongly as CN1, CN2, CN3, CN4, CN5, and CN6 bands on native-PAGE gels. Chitinase isozymes in CPC and CMC medium were expressed as 13 bands (CS1-CS13) on SDS-PAGE gels. Chitinase isozymes were expressed strongly on SDS-PAGE gels as two bands (CS6 and CS8) on YE and LB medium and 13 bands (CS1-CS13) on SPC medium. In crude enzyme, chitinase isozymes at pH 7 and pH 9 in chitin media appeared strongly on SDS-PAGE gels. Partial purified enzyme indicated high stability of enzyme activity at various temperatures and pHs in chitin medium, while these enzymes indicated low activity staining of enzyme on electrophoresis gels at various temperatures and pHs condition of chitin medium.

  6. Economic game theory to model the attenuation of virulence of an obligate intracellular bacterium

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    Damian Tago

    2016-08-01

    Full Text Available Diseases induced by obligate intracellular pathogens have a large burden on global human and animal health. Understanding the factors involved in the virulence and fitness of these pathogens contributes to the development of control strategies against these diseases. Based on biological observations, a theoretical model using game theory is proposed to explain how obligate intracellular bacteria interact with their host. The equilibrium in such a game shows that the virulence and fitness of the bacterium is host-triggered and by changing the host’s defense system to which the bacterium is confronted, an evolutionary process leads to an attenuated strain. Although, the attenuation procedure has already been conducted in practice in order to develop an attenuated vaccine (e.g. with Ehrlichia ruminantium, there was a lack of understanding of the theoretical basis behind this process. Our work provides a model to better comprehend the existence of different phenotypes and some underlying evolutionary mechanisms for the virulence of obligate intracellular bacteria.

  7. Non-specific immune response of bullfrog Rana catesbeiana to intraperitoneal injection of bacterium Aeromonas hydrophila

    Science.gov (United States)

    Zhang, Junjie; Zou, Wenzheng; Yan, Qingpi

    2008-08-01

    Non-specific immune response of bullfrog Rana catesbeiana to pathogenic Aeromonas hydrophila was studied to 60 individuals in two groups. Each bullfrog in bacterium-injected group was injected intraperitoneally (i.p.) with 0.2 ml bacterial suspension at a density of 5.2 × 106 CFU/ml, while each one in control group injected i.p. with 0.2 ml sterile saline solution (0.85%, w/v). Three bullfrogs in both groups were sampled at 0, 1, 3, 7, 11, 15 and 20 days post-injection (dpi) for the evaluation of non-specific immune parameters. It was observed that intraperitoneal injection of A. hydrophila significantly increased the number of leucocytes and that of NBT-positive cells in peripheral blood. Significant increases in serum bactericidal activity and serum acid phosphatase activity were also observed in the bacterium-injected frogs when compared with those in the control group. However, a significant reduction was detected in vitro in phagocytosis activity of peripheral blood phagocytes. No significant difference in changes in the number of peripheral erythrocytes, serum superoxide dismutase (SOD) activity, and lysozyme activity was detected between the two groups. It is suggested that bullfrogs may produce a series of non-specific immune reactions in response to the A. hydrophila infection.

  8. Isolation, identification and characteristics of an endophytic quinclorac degrading bacterium Bacillus megaterium Q3.

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    Min Liu

    Full Text Available In this study, we isolated an endophytic quinclorac-degrading bacterium strain Q3 from the root of tobacco grown in quinclorac contaminated soil. Based on morphological characteristics, Biolog identification, and 16S rDNA sequence analysis, we identified strain Q3 as Bacillus megaterium. We investigated the effects of temperature, pH, inoculation size, and initial quinclorac concentration on growth and degrading efficiency of Q3. Under the optimal degrading condition, Q3 could degrade 93% of quinclorac from the initial concentration of 20 mg/L in seven days. We analyzed the degradation products of quinclorac using liquid chromatography-tandem mass spectrometry (LC-MS/MS. The major degradation products by Q3 were different from those of previously identified quinclorac degrading strains, which suggests that Q3 may employ new pathways for quinclorac degradation. Our indoor pot experiments demonstrated that Q3 can effectively alleviate the quinclorac phytotoxicity in tobacco. As the first endophytic microbial that is capable of degrading quinclorac, Q3 can be a good bioremediation bacterium for quinclorac phytotoxicity.

  9. Melanin from the nitrogen-fixing bacterium Azotobacter chroococcum: a spectroscopic characterization.

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    Aulie Banerjee

    Full Text Available Melanins, the ubiquitous hetero-polymer pigments found widely dispersed among various life forms, are usually dark brown/black in colour. Although melanins have variety of biological functions, including protection against ultraviolet radiation of sunlight and are used in medicine, cosmetics, extraction of melanin from the animal and plant kingdoms is not an easy task. Using complementary physicochemical techniques (i.e. MALDI-TOF, FTIR absorption and cross-polarization magic angle spinning solid-state (13C NMR, we report here the characterization of melanins extracted from the nitrogen-fixing non-virulent bacterium Azotobacter chroococcum, a safe viable source. Moreover, considering dihydroxyindole moiety as the main constituent, an effort is made to propose the putative molecular structure of the melanin hetero-polymer extracted from the bacterium. Characterization of the melanin obtained from Azotobacter chroococcum would provide an inspiration in extending research activities on these hetero-polymers and their use as protective agent against UV radiation.

  10. Isolation and characterization of a prokaryotic cell organelle from the anammox bacterium Kuenenia stuttgartiensis.

    Science.gov (United States)

    Neumann, Sarah; Wessels, Hans J C T; Rijpstra, W Irene C; Sinninghe Damsté, Jaap S; Kartal, Boran; Jetten, Mike S M; van Niftrik, Laura

    2014-11-01

    Anaerobic ammonium oxidizing (anammox) bacteria oxidize ammonium with nitrite to nitrogen gas in the absence of oxygen. These microorganisms form a significant sink for fixed nitrogen in the oceans and the anammox process is applied as a cost-effective and environment-friendly nitrogen removal system from wastewater. Anammox bacteria have a compartmentalized cell plan that consists of three separate compartments. Here we report the fractionation of the anammox bacterium Kuenenia stuttgartiensis in order to isolate and analyze the innermost cell compartment called the anammoxosome. The subcellular fractions were microscopically characterized and all membranes in the anammox cell were shown to contain ladderane lipids which are unique for anammox bacteria. Proteome analyses and activity assays with the isolated anammoxosomes showed that these organelles harbor the energy metabolism in anammox cells. Together the experimental data provide the first thorough characterization of a respiratory cell organelle from a bacterium and demonstrate the essential role of the anammoxosome in the production of a major portion of the nitrogen gas in our atmosphere.

  11. The fate of a nitrobenzene-degrading bacterium in pharmaceutical wastewater treatment sludge.

    Science.gov (United States)

    Ren, Yuan; Yang, Juan; Chen, Shaoyi

    2015-12-01

    This paper describes the fate of a nitrobenzene-degrading bacterium, Klebsiella oxytoca NBA-1, which was isolated from a pharmaceutical wastewater treatment facility. The 90-day survivability of strain NBA-1 after exposure to sludge under anaerobic and aerobic conditions was investigated. The bacterium was inoculated into sludge amended with glucose and p-chloronitrobenzene (p-CNB) to compare the bacterial community variations between the modified sludge and nitrobenzene amendment. The results showed that glucose had no obvious effect on nitrobenzene biodegradation in the co-metabolism process, regardless of the presence/absence of oxygen. When p-CNB was added under anaerobic conditions, the biodegradation rate of nitrobenzene remained unchanged although p-CNB inhibited the production of aniline. The diversity of the microbial community increased and NBA-1 continued to be one of the dominant strains. Under aerobic conditions, the degradation rate of both nitrobenzene and p-CNB was only 20% of that under anaerobic conditions. p-CNB had a toxic effect on the microorganisms in the sludge so that most of the DGGE (denaturing gradient gel electrophoresis) bands, including that of NBA-1, began to disappear under aerobic conditions after 90days of exposure. These data show that the bacterial community was stable under anaerobic conditions and the microorganisms, including NBA-1, were more resistant to the adverse environment.

  12. 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.

  13. Engineering of a psychrophilic bacterium for the bioremediation of aromatic compounds.

    Science.gov (United States)

    Parrilli, Ermengilda; Papa, Rosanna; Tutino, Maria Luisa; Sannia, Giovanni

    2010-01-01

    Microbial degradation of aromatic hydrocarbons has been studied with the aim of developing applications for the removal of toxic compounds. Efforts have been directed toward the genetic manipulation of mesophilic bacteria to improve their ability to degrade pollutants, even though many pollution problems occur in sea waters and in effluents of industrial processes which are characterized by low temperatures. From these considerations the idea of engineering a psychrophilic microorganism for the oxidation of aromatic compounds was developed.In a previous paper it was demonstrated that the recombinant Antarctic Pseudoalteromonas haloplanktis TAC125 (PhTAC/tou) expressing a toluene-o-xylene monooxygenase (ToMO) is able to convert several aromatic compounds into corresponding catechols. In our work we improved the metabolic capability of PhTAC/tou cells by combining action of recombinant ToMO enzyme with that of the endogenous P. haloplanktis TAC125 laccase-like protein. This strategy allowed conferring new and specific degradative capabilities to a bacterium isolated from an unpolluted environment; indeed engineered PhTAC/tou cells are able to grow on aromatic compounds as sole carbon and energy sources. Our approach demonstrates the possibility to use the engineered psychrophilic bacterium for the bioremediation of chemically contaminated marine environments and/or cold effluents.

  14. Isolation and characterization of the dcw cluster from the piezophilic deep-sea bacterium Shewanella violacea.

    Science.gov (United States)

    Ishii, Akihiro; Nakasone, Kaoru; Sato, Takako; Wachi, Masaaki; Sugai, Motoyuki; Nagai, Kazuo; Kato, Chiaki

    2002-08-01

    The dcw cluster of genes involved in cell division and cell wall synthesis from the piezophilic deep-sea bacterium Shewanella violacea was isolated and characterized. It comprises 15 open reading frames, of which the organization is mraZ-mraW-ftsL-ftsI-murE-murF-mraY-murD-ftsW-murG-murC-ftsQ-ftsA-ftsZ-envA, in that order. To analyze transcription upstream from the ftsZ gene, Northern blot and primer extension analyses were performed. The results showed that gene expression is not pressure dependent. Western blot analysis showed that the FtsZ protein is equally expressed under several pressure conditions in the range of atmospheric (0.1 MPa) to high (50 MPa) pressures. Using immunofluorescence microscopy, the FtsZ ring was observed in the center of cells at pressure conditions of 0.1 to 50 MPa. These results imply that the FtsZ protein function is not affected by elevated pressure in this piezophilic bacterium.

  15. Functional diversity of carbohydrate-active enzymes enabling a bacterium to ferment plant biomass.

    Science.gov (United States)

    Boutard, Magali; Cerisy, Tristan; Nogue, Pierre-Yves; Alberti, Adriana; Weissenbach, Jean; Salanoubat, Marcel; Tolonen, Andrew C

    2014-11-01

    Microbial metabolism of plant polysaccharides is an important part of environmental carbon cycling, human nutrition, and industrial processes based on cellulosic bioconversion. Here we demonstrate a broadly applicable method to analyze how microbes catabolize plant polysaccharides that integrates carbohydrate-active enzyme (CAZyme) assays, RNA sequencing (RNA-seq), and anaerobic growth screening. We apply this method to study how the bacterium Clostridium phytofermentans ferments plant biomass components including glucans, mannans, xylans, galactans, pectins, and arabinans. These polysaccharides are fermented with variable efficiencies, and diauxies prioritize metabolism of preferred substrates. Strand-specific RNA-seq reveals how this bacterium responds to polysaccharides by up-regulating specific groups of CAZymes, transporters, and enzymes to metabolize the constituent sugars. Fifty-six up-regulated CAZymes were purified, and their activities show most polysaccharides are degraded by multiple enzymes, often from the same family, but with divergent rates, specificities, and cellular localizations. CAZymes were then tested in combination to identify synergies between enzymes acting on the same substrate with different catalytic mechanisms. We discuss how these results advance our understanding of how microbes degrade and metabolize plant biomass.

  16. Extreme furfural tolerance of a soil bacterium Enterobacter cloacae GGT036.

    Science.gov (United States)

    Choi, Sun Young; Gong, Gyeongtaek; Park, Hong-Sil; Um, Youngsoon; Sim, Sang Jun; Woo, Han Min

    2015-01-10

    Detoxification process of cellular inhibitors including furfural is essential for production of bio-based chemicals from lignocellulosic biomass. Here we isolated an extreme furfural-tolerant bacterium Enterobacter cloacae GGT036 from soil sample collected in Mt. Gwanak, Republic of Korea. Among isolated bacteria, only E. cloacae GGT036 showed cell growth with 35 mM furfural under aerobic culture. Compared to the maximal half inhibitory concentration (IC50) of well-known industrial strains Escherichia coli (24.9 mM furfural) and Corynebacterium glutamicum (10 mM furfural) based on the cell density, IC50 of E. cloacae GGT036 (47.7 mM) was significantly higher after 24 h, compared to E. coli and C. glutamicum. Since bacterial cell growth was exponentially inhibited depending on linearly increased furfural concentrations in the medium, we concluded that E. cloacae GGT036 is an extreme furfural-tolerant bacterium. Recently, the complete genome sequence of E. cloacae GGT036 was announced and this could provide an insight for engineering of E. cloacae GGT036 itself or other industrially relevant bacteria.

  17. Enhanced Cadmium (Cd Phytoextraction from Contaminated Soil using Cd-Resistant Bacterium

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    Kunchaya Setkit

    2014-01-01

    Full Text Available A cadmium (Cd-resistant bacterium, Micrococcus sp. MU1, is able to produce indole-3-acetic acid and promotes root elongation and plant growth. The potential of this bacterium on enhancement of Cd uptake and bioaccumulation of Cd in Helianthus annuus L. planted in Cd-contaminated soil was evaluated in greenhouse condition. The results showed that Micrococcus sp. MU1promoted the growth of H. annuus L. by increasing the root length, stem height, dry biomass, root to shoot ratio and also significantly increased Cd accumulation in the root and above-ground tissues of H. annuus L. compared to uninoculated control. Re-inoculation with Micrococcus sp. MU1in contaminated soil helped in promoting plant growth and Cd phytoextraction throughout the cultivation period. In addition, phytoextraction coefficient and translocation factor (TF of H. annuus L. inoculated with Micrococcus sp. MU1were higher than that of uninoculated control and TF continuously increased with time. Our results suggested that Micrococcus sp. MU1 has an ability to enhance plant growth and Cd uptake in H. annuus L. Synergistic interaction between Micrococcus sp. MU1 and H. annuus L. could be further applied for Cd phytoextraction in polluted areas.

  18. Data supporting functional diversity of the marine bacterium Cobetia amphilecti KMM 296

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    Larissa Balabanova

    2016-09-01

    Full Text Available Data is presented in support of functionality of hyper-diverse protein families encoded by the Cobetia amphilecti KMM 296 (formerly Cobetia marina KMM 296 genome (“The genome of the marine bacterium Cobetia marina KMM 296 isolated from the mussel Crenomytilus grayanus (Dunker, 1853” [1] providing its nutritional versatility, adaptability and biocontrol that could be the basis of the marine bacterium evolutionary and application potential. Presented data include the information of growth and biofilm-forming properties of the food-associated isolates of Pseudomonas, Bacillus, Listeria, Salmonella and Staphylococcus under the conditions of their co-culturing with C. amphilecti KMM 296 to confirm its high inter-species communication and anti-microbial activity. Also included are the experiments on the crude petroleum consumption by C. amphilecti KMM 296 as the sole source of carbon in the presence of sulfate or nitrate to ensure its bioremediation capacity. The multifunctional C. amphilecti KMM 296 genome is a promising source for the beneficial psychrophilic enzymes and essential secondary metabolites.

  19. Improvement of the production of vitamin B12 by Pseudomonas denitrifican through increasing the fermenter pressure%增大罐压提高脱氮假单胞菌发酵生产维生素B12的产量

    Institute of Scientific and Technical Information of China (English)

    刘玉伟; 王建; 王泽建; 黄明志

    2012-01-01

    [Objective] The pressure of fermenter was enhanced in order to increase the concentration of vitamin B12. [Methods] Metabolic flux analysis (MFA) was used to analyse the fermentation process of vitamin B12 production by Pseudomonas denitrifwan. [Results] The results indicated that the metabolic flux of oxaloacetic acid from phosphoenolpyruvate car-boxylation was increased when the synthesis rate of vitamin B12 increased, in order to meet the demand for precursor supply to vitamin B12 production. A novel control strategy was designedas following. The pressure of fermenter was enhanced in order to increase the solubility of carbon dioxide in aqueous solution at steady phase of fermentation, so more carbon dioxide was carboxylated to oxaloacetic acid. The result showed that the concentration of vitamin B12 was 176 mg/L, 19.7% higher than the control batch (147 mg/L) at 160 hours. [Conclusion] the production of vitamin B12 by Pseudomonas denitrifican was improved by increasing the fermenter pressure.%[目的]提高发酵罐的罐压,增加维生素B12的产率.[方法]利用常规代谢通量分析(MFA)方法,对脱氮假单胞菌生产维生素B12的发酵过程进行研究.[结果]发现随着VB12合成速率的加快,磷酸烯醇式丙酮酸(PEP)羧化生成草酰乙酸(OAA)的通量明显加大,以满足维生素B12合成对前体的需求.根据该分析结果,对发酵工艺进行了改进,即在脱氮假单胞菌进入合成维生素B12阶段时,提高发酵罐的罐压,增加发酵液中二氧化碳的溶解度,从而强化了羧化回补途径.维生素B12的产率明显增加,发酵160 h的产物浓度为176 mg/L,比对照批次终浓度147 mg/L高出了19.7%.[结论]通过增大罐压提高了脱氮假单胞菌进入合成维生素B12的产量.

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

    Institute of Scientific and Technical Information of China (English)

    SHI Shunyu; LIU Yongding; SHEN Yinwu; LI Genbao

    2005-01-01

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

  1. Bacterium-like Particles for efficient immune stimulation of existing vaccines and new subunit vaccines in mucosal applications

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    Natalija eVan Braeckel-Budimir

    2013-09-01

    Full Text Available The successful development of a mucosal vaccine critically depends on the use of a safe and effective immunostimulant and/or carrier system. This review describes the effectiveness and mode of action of an immunostimulating particle derived from bacteria in mucosal subunit vaccines. The non-living particles, designated Bacterium-like Particles (BLPs are based on the food-grade bacterium Lactococcus lactis. The focus of the overview is on the development of intranasal BLP-based vaccines to prevent diseases caused by influenza and respiratory syncytial virus, and includes a selection of Phase I clinical data for the intranasal FluGEM vaccine.

  2. Draft Genome Sequence of the Endophytic Bacterium Enterobacter spp. MR1, Isolated from Drought Tolerant Plant (Butea monosperma).

    Science.gov (United States)

    Parakhia, Manoj V; Tomar, Rukam S; Malaviya, Bipin J; Dhingani, Rashmin M; Rathod, Visha M; Thakkar, Jalpa R; Golakiya, B A

    2014-03-01

    Enterobacter sp. MR1 an endophytic plant growth promoting bacterium was isolated from the roots of Butea monosperma, a drought tolerant plant. Genome sequencing of Enterobacter spp. MR1 was carried out in Ion Torrent (PGM), Next Generation Sequencer. The data obtained revealed 640 contigs with genome size of 4.58 Mb and G+C content of 52.8 %. This bacterium may contain genes responsible for inducing drought tolerance in plant, including genes for phosphate solubilization, growth hormones and other useful genes for plant growth.

  3. High Prevalence of Antibodies against the Bacterium Treponema pallidum in Senegalese Guinea Baboons (Papio papio.

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    Sascha Knauf

    Full Text Available The bacterium Treponema pallidum is known to cause syphilis (ssp. pallidum, yaws (ssp. pertenue, and endemic syphilis (ssp. endemicum in humans. Nonhuman primates have also been reported to be infected with the bacterium with equally versatile clinical manifestations, from severe skin ulcerations to asymptomatic. At present all simian strains are closely related to human yaws-causing strains, an important consideration for yaws eradication. We tested clinically healthy Guinea baboons (Papio papio at Parc National Niokolo Koba in south eastern Senegal for the presence of anti-T. pallidum antibodies. Since T. pallidum infection in this species was identified 50 years ago, and there has been no attempt to treat non-human primates for infection, it was hypothesized that a large number of West African baboons are still infected with simian strains of the yaws-bacterium. All animals were without clinical signs of treponematoses, but 18 of 20 (90% baboons tested positive for antibodies against T. pallidum based on treponemal tests. Yet, Guinea baboons seem to develop no clinical symptoms, though it must be assumed that infection is chronic or comparable to the latent stage in human yaws infection. The non-active character is supported by the low anti-T. pallidum serum titers in Guinea baboons (median = 1:2,560 versus serum titers that are found in genital-ulcerated olive baboons with active infection in Tanzania (range of medians among the groups of initial, moderate, and severe infected animals = 1:15,360 to 1:2.097e+7. Our findings provide evidence for simian infection with T. pallidum in wild Senegalese baboons. Potentially, Guinea baboons in West Africa serve as a natural reservoir for human infection, as the West African simian strain has been shown to cause sustainable yaws infection when inoculated into humans. The present study pinpoints an area where further research is needed to support the currently on-going second WHO led yaws eradication

  4. Metabolism of 4-chloro-2-nitrophenol in a Gram-positive bacterium, Exiguobacterium sp. PMA

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    Arora Pankaj

    2012-11-01

    Full Text Available Abstract Background Chloronitrophenols (CNPs are widely used in the synthesis of dyes, drugs and pesticides, and constitute a major group of environmental pollutants. 4-Chloro-2-nitrophenol (4C2NP is an isomer of CNPs that has been detected in various industrial effluents. A number of physicochemical methods have been used for treatment of wastewater containing 4C2NP. These methods are not as effective as microbial degradation, however. Results A 4C2NP-degrading bacterium, Exiguobacterium sp. PMA, which uses 4C2NP as the sole carbon and energy source was isolated from a chemically-contaminated site in India. Exiguobacterium sp. PMA degraded 4C2NP with the release of stoichiometeric amounts of chloride and ammonium ions. The effects of different substrate concentrations and various inoculum sizes on degradation of 4C2NP were investigated. Exiguobacterium sp. PMA degraded 4C2NP up to a concentration of 0.6 mM. High performance liquid chromatography and gas chromatography–mass spectrometry identified 4-chloro-2-aminophenol (4C2AP and 2-aminophenol (2AP as possible metabolites of the 4C2NP degradation pathway. The crude extract of 4C2NP-induced PMA cells contained enzymatic activity for 4C2NP reductase and 4C2AP dehalogenase, suggesting the involvement of these enzymes in the degradation of 4C2NP. Microcosm studies using sterile and non-sterile soils spiked with 4C2NP were carried out to monitor the bioremediation potential of Exiguobacterium sp. PMA. The bioremediation of 4C2NP by Exiguobacterium sp. PMA was faster in non-sterilized soil than sterilized soil. Conclusions Our studies indicate that Exiguobacterium sp. PMA may be useful for the bioremediation of 4C2NP-contaminated sites. This is the first report of (i the formation of 2AP in the 4C2NP degradation pathway by any bacterium and (iii the bioremediation of 4C2NP by any bacterium.

  5. Complete Genome Sequence of the Unclassified Iron-Oxidizing, Chemolithoautotrophic Burkholderiales Bacterium GJ-E10, Isolated from an Acidic River.

    Science.gov (United States)

    Fukushima, Jun; Tojo, Fuyumi; Asano, Ryoki; Kobayashi, Yayoi; Shimura, Yoichiro; Okano, Kunihiro; Miyata, Naoyuki

    2015-02-05

    Burkholderiales bacterium GJ-E10, isolated from the Tamagawa River in Akita Prefecture, Japan, is an unclassified, iron-oxidizing chemolithoautotrophic bacterium. Its single circular genome, consisting of 3,276,549 bp, was sequenced by using three types of next-generation sequencers and the sequences were then confirmed by PCR-based Sanger sequencing.

  6. Mathematical model of the Lux luminescence system in the terrestrial bacterium Photorhabdus luminescens.

    Science.gov (United States)

    Welham, Patricia A; Stekel, Dov J

    2009-01-01

    A mathematical model of the Lux luminescence system, governed by the operon luxCDABE in the terrestrial bacterium Photorhabdus luminescens, was constructed using a set of coupled ordinary differential equations. This model will have value in the interpretation of Lux data when used as a reporter in time-course gene expression experiments. The system was tested on time series and stationary data from published papers and the model is in good agreement with the published data. Metabolic control analysis demonstrates that control of the system lies mainly with the aldehyde recycling pathway (LuxE and LuxC). The rate at which light is produced in the steady state model shows a low sensitivity to changes in kinetic parameter values to those measured in other species of luminescent bacteria, demonstrating the robustness of the Lux system.

  7. Chemical compounds effective against the citrus Huanglongbing bacterium 'Candidatus Liberibacter asiaticus' in planta.

    Science.gov (United States)

    Zhang, Muqing; Powell, Charles A; Zhou, Lijuan; He, Zhenli; Stover, Ed; Duan, Yongping

    2011-09-01

    Citrus Huanglongbing (HLB) is one of the most destructive diseases of citrus worldwide and is threatening the survival of the Floridian citrus industry. Currently, there is no established cure for this century-old and emerging disease. As a possible control strategy for citrus HLB, therapeutic compounds were screened using a propagation test system with 'Candidatus Liberibacter asiaticus'-infected periwinkle and citrus plants. The results demonstrated that the combination of penicillin and streptomycin (PS) was effective in eliminating or suppressing the 'Ca. L. asiaticus' bacterium and provided a therapeutically effective level of control for a much longer period of time than when administering either antibiotic separately. When treated with the PS, 'Ca. L. asiaticus'-infected periwinkle cuttings achieved 70% of regeneration rates versus citrus plants. This may provide a useful tool for the management of citrus HLB and other Liberibacter-associated diseases.

  8. Biosynthesis and characterization of polyhydroxyalkanoates in the polysaccharide-degrading marine bacterium Saccharophagus degradans ATCC 43961.

    Science.gov (United States)

    González-García, Yolanda; Nungaray, Jesús; Córdova, Jesús; González-Reynoso, Orfil; Koller, Martin; Atlic, Aid; Braunegg, Gerhart

    2008-06-01

    The marine bacterium Saccharophagus degradans was investigated for the synthesis of polyhydroxyalkanoates (PHAs), using glucose as the sole source of carbon in a two-step batch culture. In the first step the microorganism grew under nutrient balanced conditions; in the second step the cells were cultivated under limitation of nitrogen source. The biopolymer accumulated in S. degradans cells was detected by Nile red staining and FT-IR analysis. From GC-MS analysis, it was found that this strain produced a homopolymer of 3-hydroxybutyric acid. The cellular polymer concentration, its molecular mass, glass transition temperature, melting point and heat of fusion were 17.2+/-2.7% of dry cell weight, 54.2+/-0.6 kDa, 37.4+/-6.0 degrees C, 165.6+/-5.5 degrees C and 59.6+/-2.2 J g(-1), respectively. This work is the first report determining the capacity of S. degradans to synthesize PHAs.

  9. Bioethanol production from mannitol by a newly isolated bacterium, Enterobacter sp. JMP3.

    Science.gov (United States)

    Wang, Jing; Kim, Young Mi; Rhee, Hong Soon; Lee, Min Woo; Park, Jong Moon

    2013-05-01

    In this study a new bacterium capable of growing on brown seaweed Laminaria japonica, Enterobacter sp. JMP3 was isolated from the gut of turban shell, Batillus cornutus. In anaerobic condition, it produced high yields of ethanol (1.15 mol-EtOH mol-mannitol(-1)) as well as organic acids from mannitol, the major carbohydrate component of L. japonica. Based on carbon distribution and metabolic flux analysis, it was revealed that mannitol was more favorable than glucose for ethanol production due to their different redox states. This indicates that L. japonica is one of the promising feedstock for bioethanol production. Additionally, the mannitol dehydrogenation pathway in Enterobacter sp. JMP3 was examined and verified. Finally, an attempt was made to explore the possibility of controlling ethanol production by altering the redox potential via addition of external NADH in mannitol fermentation.

  10. Isolation of Aureimonas altamirensis, a Brucella canis-like bacterium, from an edematous canine testicle.

    Science.gov (United States)

    Reilly, Thomas J; Calcutt, Michael J; Wennerdahl, Laura A; Williams, Fred; Evans, Tim J; Ganjam, Irene K; Bowman, Jesse W; Fales, William H

    2014-11-01

    Microbiological and histological analysis of a sample from a swollen testicle of a 2-year-old Border Collie dog revealed a mixed infection of the fungus Blastomyces dermatitidis and the Gram-negative bacterium Aureimonas altamirensis. When subjected to an automated microbial identification system, the latter isolate was provisionally identified as Psychrobacter phenylpyruvicus, but the organism shared several biochemical features with Brucella canis and exhibited agglutination, albeit weakly, with anti-B. canis antiserum. Unequivocal identification of the organism was only achieved by 16S ribosomal RNA gene sequencing, ultimately establishing the identity as A. altamirensis. Since its first description in 2006, this organism has been isolated infrequently from human clinical samples, but, to the authors' knowledge, has not been reported from a veterinary clinical sample. While of unknown clinical significance with respect to the pathology observed for the polymicrobial infection described herein, it highlights the critical importance to unambiguously identify the microbe for diagnostic, epidemiological, infection control, and public health purposes.

  11. A Marine Sulfate-Reducing Bacterium Producing Multiple Antibiotics: Biological and Chemical Investigation

    Directory of Open Access Journals (Sweden)

    Xiaoliang Wang

    2009-07-01

    Full Text Available A marine sulfate-reducing bacterium SRB-22 was isolated by means of the agar shake dilution method and identified as Desulfovibrio desulfuricans by morphological, physiological and biochemical characteristics and 16S rDNA analysis. In the bioassay, its extract showed broad-spectrum antimicrobial activity using the paper disc agar diffusion method. This isolate showed a different antimicrobial profile than either ampicillin or nystatin and was found to produce at least eight antimicrobial components by bioautography. Suitable fermentation conditions for production of the active constituents were determined to be 28 day cultivation at 25 °C to 30 °C with a 10% inoculation ratio. Under these conditions, the SRB-22 was fermented, extracted and chemically investigated. So far an antimicrobial compound, mono-n-butyl phthalate, and an inactive compound, thymine, have been isolated and characterized.

  12. Heterotrophic ammonium removal characteristics of an aerobic heterotrophic nitrifying-denitrifying bacterium, Providencia rettgeri YL

    Institute of Scientific and Technical Information of China (English)

    TAYLOR Shauna M; HE Yiliang; ZHAO Bin; HUANG Jue

    2009-01-01

    Bacterium Providencia rettgeri YL was found to exhibit an unusual ability to heterotrophically nitrify and aerobically denitrify various concentrations of ammonium (NH4+-N). In order to further analyze its removal ability, several experiments were conducted to identify the growth and ammonium removal response in different carbon to nitrogen (C/N) mass ratios, shaking speeds, temperatures, ammonium concentrations and to qualitatively verify the production of nitrogen gas using gas chromatography techniques. Results showed that under optimum conditions (C/N 10, 30℃, 120 r/min), YL can significantly remove low and high concentrations of ammonium within 12 to 48 h of growth. The nitrification products hydroxylamine (NH2OH), nitrite (NO2-) and nitrate (NO3-) as well as the denitrification product, nitrogen gas (N2), were detected under completely aerobic conditions.

  13. Identification of a denitrifying bacterium and verification of its anaerobic ammonium oxidation ability

    Institute of Scientific and Technical Information of China (English)

    HU; Baolan; ZHENG; Ping; LI; Jinye; XU; Xiangyang; JIN; Rencun

    2006-01-01

    A strain D3 of denitrifying bacterium was isolated from an anammox reactor, and identified as Pseudomonas mendocina based on the morphological and physiological assay, Vitek test,Biolog test, (G+C) mol% content, and 16S rDNA phylogenetic analysis. As a typical denitrifying bactration of 88.5 mg N/L. The optimal pH and growth temperature were 7.84 and 34.9℃, respectively.Strain D3 was able to oxidize ammonia under anaerobic condition. The maximum nitrate and ammoof ammonia to nitrate was 1:1.91. Electron microscopic observation revealed peculiar cell inclusions in strain D3. Because of its relation to anammox activity, strain D3 was presumed to be anammoxosome.The present investigation proved that denitrifying bacteria have the anammox ability, and the results have engorged the range of anammox populations.

  14. Continuous synthesis and excretion of the compatible solute ectoine by a transgenic, nonhalophilic bacterium.

    Science.gov (United States)

    Schubert, Torsten; Maskow, Thomas; Benndorf, Dirk; Harms, Hauke; Breuer, Uta

    2007-05-01

    The compatible solute 1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid (ectoine) acts in microorganisms as an osmotic counterweight against halostress and has attracted commercial attention as a protecting agent. Its production and application are restricted by the drawbacks of the discontinuous harvesting procedure involving salt shocks, which reduces volumetric yield, increases reactor corrosion, and complicates downstream processing. In order to synthesize ectoine continuously in less-aggressive media, we introduced the ectoine genes ectABC of the halophilic bacterium Chromohalobacter salexigens into an Escherichia coli strain using the expression vector pASK-IBA7. Under the control of a tet promoter, the transgenic E. coli synthesized 6 g liter-1 ectoine with a space-time yield of 40 mg liter-1 h-1, with the vast majority of the ectoine being excreted.

  15. [Isolation and characteristic of a moderately halophilic bacterium accumulated ectoine as main compatible solute].

    Science.gov (United States)

    He, Jian; Wang, Ting; Sun, Ji-Quan; Gu, Li-Feng; Li, Shun-Peng

    2005-12-01

    A moderately halophilic bacterium(designated strain I15) was isolated from lawn soil. Based on the analysis of 16S rDNA (GenBank accession number DQ010162), morphology, physiological and biochemical characteristics, strain I15 was identified as Virgibacillus marismortuii. This strain was capable of growing under 0% approximately 25% NaCl, and exhibited an optimum NaCl concentration of 10% and an optimum temperature of 30 degrees C and an optimum pH of 7.5 - 8.0 for its growth, respectively. Under hyperosmotic stress, strain 115 accumulated ectoine as the main compatible solute. Under 15% NaCl conditions the intracellar ectoine can reach to 1.608 mmol/(g x cdw), accounted for 89.6% of the total compatible solutes. The biosynthesis of ectoine was under the control of osmotic, and the accumulated ectoine synthesized intraceilularly can released under hypoosmotic shocks and resynthesis under hyperosmotic shock rapidly.

  16. A Mutant Strain of a Surfactant-Producing Bacterium with Increased Emulsification Activity

    Institute of Scientific and Technical Information of China (English)

    Liu Qingmei; Yao Jianming; Pan Renrui; Yu Zengliang

    2005-01-01

    As reported in this paper, a strain of oil-degrading bacterium Sp- 5- 3 was determined to belong to Enterobacteriaceae, which would be useful for microbial enhanced oil recovery(MEOR). The aim of our study was to generate a mutant using low energy N+ beam implantation. With 10 keV of energy and 5.2 × 10TM N+/cm2 of dose - the optimum condition, a mutant,S - 34, was obtained, which had nearly a 5-fold higher surface and a 13-fold higher of emulsification activity than the wild type. The surface activity was measured by two methods, namely, a surface tension measuring instrument and a recording of the repulsive circle of the oil film; the emulsification activity was scaled through measuring the separating time of the oil-fermentation mixture. The metabolic acid was determined as methane by means of gas chromatography.

  17. Draft whole genome sequence of the cyanide-degrading bacterium Pseudomonas pseudoalcaligenes CECT5344.

    Science.gov (United States)

    Luque-Almagro, Víctor M; Acera, Felipe; Igeño, Ma Isabel; Wibberg, Daniel; Roldán, Ma Dolores; Sáez, Lara P; Hennig, Magdalena; Quesada, Alberto; Huertas, Ma José; Blom, Jochen; Merchán, Faustino; Escribano, Ma Paz; Jaenicke, Sebastian; Estepa, Jessica; Guijo, Ma Isabel; Martínez-Luque, Manuel; Macías, Daniel; Szczepanowski, Rafael; Becerra, Gracia; Ramirez, Silvia; Carmona, Ma Isabel; Gutiérrez, Oscar; Manso, Isabel; Pühler, Alfred; Castillo, Francisco; Moreno-Vivián, Conrado; Schlüter, Andreas; Blasco, Rafael

    2013-01-01

    Pseudomonas pseudoalcaligenes CECT5344 is a Gram-negative bacterium able to tolerate cyanide and to use it as the sole nitrogen source. We report here the first draft of the whole genome sequence of a P. pseudoalcaligenes strain that assimilates cyanide. Three aspects are specially emphasized in this manuscript. First, some generalities of the genome are shown and discussed in the context of other Pseudomonadaceae genomes, including genome size, G + C content, core genome and singletons among other features. Second, the genome is analysed in the context of cyanide metabolism, describing genes probably involved in cyanide assimilation, like those encoding nitrilases, and genes related to cyanide resistance, like the cio genes encoding the cyanide insensitive oxidases. Finally, the presence of genes probably involved in other processes with a great biotechnological potential like production of bioplastics and biodegradation of pollutants also is discussed.

  18. Structure of ribose 5-phosphate isomerase from the probiotic bacterium Lactobacillus salivarius UCC118.

    Science.gov (United States)

    Lobley, Carina M C; Aller, Pierre; Douangamath, Alice; Reddivari, Yamini; Bumann, Mario; Bird, Louise E; Nettleship, Joanne E; Brandao-Neto, Jose; Owens, Raymond J; O'Toole, Paul W; Walsh, Martin A

    2012-12-01

    The structure of ribose 5-phosphate isomerase from the probiotic bacterium Lactobacillus salivarius UCC188 has been determined at 1.72 Å resolution. The structure was solved by molecular replacement, which identified the functional homodimer in the asymmetric unit. Despite only showing 57% sequence identity to its closest homologue, the structure adopted the typical α and β D-ribose 5-phosphate isomerase fold. Comparison to other related structures revealed high homology in the active site, allowing a model of the substrate-bound protein to be proposed. The determination of the structure was expedited by the use of in situ crystallization-plate screening on beamline I04-1 at Diamond Light Source to identify well diffracting protein crystals prior to routine cryocrystallography.

  19. Two-dimensional gel-based alkaline proteome of the probiotic bacterium Lactobacillus acidophilus NCFM

    DEFF Research Database (Denmark)

    Majumder, Avishek; Cai, Liyang; Ejby, Morten

    2012-01-01

    gel using MALDI‐TOF‐MS. The 102 unique gene products among the 150 protein identifications were assigned to different functional categories, and evaluated by considering a calculated distribution of abundance as well as grand average of hydrophobicity values. None of the very few available lactic acid......Lactobacillus acidophilus NCFM (NCFM) is a well‐documented probiotic bacterium isolated from human gut. Detailed 2D gel‐based NCFM proteomics addressed the so‐called alkaline range, i.e., pH 6–11. Proteins were identified in 150 of the 202 spots picked from the Coomassie Brilliant Blue stained 2D...... bacteria proteome reference maps included the range of pI >7.0. The present report of such data on the proteome of NCFM fundamentally complements current knowledge on protein profiles limited to the acid and neutral pH range....

  20. Genome sequence of the bioplastic-producing "Knallgas" bacterium Ralstonia eutropha H16.

    Science.gov (United States)

    Pohlmann, Anne; Fricke, Wolfgang Florian; Reinecke, Frank; Kusian, Bernhard; Liesegang, Heiko; Cramm, Rainer; Eitinger, Thomas; Ewering, Christian; Pötter, Markus; Schwartz, Edward; Strittmatter, Axel; Voss, Ingo; Gottschalk, Gerhard; Steinbüchel, Alexander; Friedrich, Bärbel; Bowien, Botho

    2006-10-01

    The H(2)-oxidizing lithoautotrophic bacterium Ralstonia eutropha H16 is a metabolically versatile organism capable of subsisting, in the absence of organic growth substrates, on H(2) and CO(2) as its sole sources of energy and carbon. R. eutropha H16 first attracted biotechnological interest nearly 50 years ago with the realization that the organism's ability to produce and store large amounts of poly[R-(-)-3-hydroxybutyrate] and other polyesters could be harnessed to make biodegradable plastics. Here we report the complete genome sequence of the two chromosomes of R. eutropha H16. Together, chromosome 1 (4,052,032 base pairs (bp)) and chromosome 2 (2,912,490 bp) encode 6,116 putative genes. Analysis of the genome sequence offers the genetic basis for exploiting the biotechnological potential of this organism and provides insights into its remarkable metabolic versatility.

  1. Characterization of a halotolerant-psychroloterant bacterium from dry valley Antarctic soil.

    Science.gov (United States)

    Miller, K J; Leschine, S B; Huguenin, R L

    1983-01-01

    The saline soils of the ice free dry valleys of Victoria Land, Antarctica may provide the closest analog on Earth to Martian conditions. We have initiated a study aimed at examining microbial adaptations to the harsh environment of these dry valley soils. In this report we describe the characterization of one bacterium, strain A4a, isolated from Taylor Valley soil. Strain A4a was an obligately aerobic, orange-pigmented, Gram-positive coccus that grew over wide ranges of both temperature (0 degrees C-40 degrees C) and sodium chloride concentration (0-2.0M). The optimal temperature for growth at all NaCl concentrations was 25 degrees C. Phospholipid composition and guanine plus cytosine content of the DNA of the isolate indicate a close relation to the genus Planococcus.

  2. The structure of ferricytochrome c552 from the psychrophilic marine bacterium Colwellia psychrerythraea 34H

    Science.gov (United States)

    Harvilla, Paul B.; Wolcott, Holly N.

    2014-01-01

    Approximately 40% of all proteins are metalloproteins, and approximately 80% of Earth’s ecosystems are at temperatures ≤ 5 °C, including 90% of the global ocean. Thus, an essential aspect of marine metallobiochemistry is an understanding of the structure, dynamics, and mechanisms of cold adaptation of metalloproteins from marine microorganisms. Here, the molecular structure of the electron-transfer protein cytochrome c552 from the psychrophilic marine bacterium Colwellia psychrerythraea 34H has been determined by X-ray crystallography (PDB: 4O1W). The structure is highly superimposable with that of the homologous cytochrome from the mesophile Marinobacter hydrocarbonoclasticus. Based on structural analysis and comparison of psychrophilic, psychrotolerant, and mesophilic sequences, a methionine-based ligand-substitution mechanism for psychrophilic protein stabilization is proposed. PMID:24727932

  3. [Expression of phosphofructokinase gene from Escherichia coli K-12 in obligately autotrophic bacterium Acidithiobacillus thiooxidans].

    Science.gov (United States)

    Tian, Keli; Lin, Jianqun; Liu, Xiangmei; Liu, Ying; Zhang, Changkai

    2003-10-01

    A plasmid pSDK-1 containing the Escherichia coli phosphofructokinase-1 (EC 2.7.1. 11) gene (pfkA) was constructed and transferred into Acidithiobacillus thiooxidans Tt-Z2 by conjugation. The transfer frequency of plasmid from E. coli to Tt-Z2 was 2.6 x 10(-6). More than 68% of Tt-Z2 cells carried the recombinant plasmids after being cultured for 50 generations without selective pressure, which showed that pSDK-1 was maintained consistently in Tt-Z2. The pfkA gene from E. coli could be expressed in this obligately autotrophic bacterium but the enzyme activity (14 U/g was lower than that in E. coli (K-12: 86 U/g; DF1010 carrying plasmid pSDK-1: 97 U/g). In th presence of glucose, the Tt-Z2 transconjugant consumed glucose leading to a better growth yield.

  4. Complete genome of Nitrosospira briensis C-128, an ammonia-oxidizing bacterium from agricultural soil.

    Science.gov (United States)

    Rice, Marlen C; Norton, Jeanette M; Valois, Frederica; Bollmann, Annette; Bottomley, Peter J; Klotz, Martin G; Laanbroek, Hendrikus J; Suwa, Yuichi; Stein, Lisa Y; Sayavedra-Soto, Luis; Woyke, Tanja; Shapiro, Nicole; Goodwin, Lynne A; Huntemann, Marcel; Clum, Alicia; Pillay, Manoj; Kyrpides, Nikos; Varghese, Neha; Mikhailova, Natalia; Markowitz, Victor; Palaniappan, Krishna; Ivanova, Natalia; Stamatis, Dimitrios; Reddy, T B K; Ngan, Chew Yee; Daum, Chris

    2016-01-01

    Nitrosospira briensis C-128 is an ammonia-oxidizing bacterium isolated from an acid agricultural soil. N. briensis C-128 was sequenced with PacBio RS technologies at the DOE-Joint Genome Institute through their Community Science Program (2010). The high-quality finished genome contains one chromosome of 3.21 Mb and no plasmids. We identified 3073 gene models, 3018 of which are protein coding. The two-way average nucleotide identity between the chromosomes of Nitrosospira multiformis ATCC 25196 and Nitrosospira briensis C-128 was found to be 77.2 %. Multiple copies of modules encoding chemolithotrophic metabolism were identified in their genomic context. The gene inventory supports chemolithotrophic metabolism with implications for function in soil environments.

  5. Strain IMB-1, a novel bacterium for the removal of methyl bromide in fumigated agricultural soils

    Science.gov (United States)

    Connell, Hancock T.L.; Costello, A.M.; Lidstrom, M.E.; Oremland, R.S.

    1998-01-01

    A facultatively methylotrophic bacterium, strain IMB-1, that has been isolated from agricultural soil grows on methyl bromide (MeBr), methyl iodide, methyl chloride, and methylated amines, as well as on glucose, pyruvate, or acetate. Phylogenetic analysis of its 16S rRNA gene sequence indicates that strain IMB-1 classes in the alpha subgroup of the class Proteobacteria and is closely related to members of the genus Rhizobium. The ability of strain IMB-1 to oxidize MeBr to CO2 is constitutive in cells regardless of the growth substrate. Addition of cell suspensions of strain IMB-1 to soils greatly accelerates the oxidation of MeBr, as does pretreatment of soils with low concentrations of methyl iodide. These results suggest that soil treatment strategies can be devised whereby bacteria can effectively consume MeBr during field fumigations, which would diminish or eliminate the outward flux of MeBr to the atmosphere.

  6. Genetic manipulation of carotenoid biosynthesis in the green sulfur bacterium Chlorobium tepidum

    DEFF Research Database (Denmark)

    Frigaard, Niels-Ulrik; Maresca, Julia A; Yunker, Colleen E

    2004-01-01

    The green sulfur bacterium Chlorobium tepidum is a strict anaerobe and an obligate photoautotroph. On the basis of sequence similarity with known enzymes or sequence motifs, nine open reading frames encoding putative enzymes of carotenoid biosynthesis were identified in the genome sequence of C....... tepidum, and all nine genes were inactivated. Analysis of the carotenoid composition in the resulting mutants allowed the genes encoding the following six enzymes to be identified: phytoene synthase (crtB/CT1386), phytoene desaturase (crtP/CT0807), zeta-carotene desaturase (crtQ/CT1414), gamma......-carotene desaturase (crtU/CT0323), carotenoid 1',2'-hydratase (crtC/CT0301), and carotenoid cis-trans isomerase (crtH/CT0649). Three mutants (CT0180, CT1357, and CT1416 mutants) did not exhibit a discernible phenotype. The carotenoid biosynthetic pathway in C. tepidum is similar to that in cyanobacteria and plants...

  7. Extraction and physicochemical characteristics of a red pigment produced by marine bacterium strain S-9801

    Institute of Scientific and Technical Information of China (English)

    田黎; 何培青; 刘晨临; 边际; 苗金来

    2002-01-01

    -- A red pigment that has better biological properties is produced by marine bacterium strain S- 9801. The extraction methods, physicochemical and toxicity of the pigment have been studied.Dissolubility of pigment in the five organic solvent has been tested, and ethanol is optimally chosen for extraction. Physicochemical characteristics of this pigment was stable. The absorbance of the pigment solution was no losing when put under natural light for 10 days or treated by UV for 30 minutes, color of the pigment unchanged after 100 ℃ hythere for 1 h or 80 ℃ xerother for 2 h. The median lethal dose (LD50) of the rat by celiac injection was 670.04 mg/kg and minimum lethal dose of oral was greater than 2 000 mg/kg.

  8. Solubilization of zinc compounds by the diazotrophic, plant growth promoting bacterium Gluconacetobacter diazotrophicus.

    Science.gov (United States)

    Saravanan, V S; Madhaiyan, M; Thangaraju, M

    2007-01-01

    Gluconacetobacter diazotrophicus an endophytic diazotroph also encountered as rhizosphere bacterium is reported to possess different plant growth promoting characteristics. In this study, we assessed the zinc solubilizing potential of G. diazotrophicus under in vitro conditions with different Zn compounds using glucose or sucrose as carbon sources. G. diazotrophicus showed variations in their solubilization potential with the strains used and the Zn compounds tested. G. diazotrophicus PAl5 efficiently solubilized the Zn compounds tested and ZnO was effectively solubilized than ZnCO(3) or Zn(3)(PO(4))(2). The soluble Zn concentration was determined in the culture supernatant through Atomic Absorption Spectrophotometer. Gas chromatography coupled Mass Spectrometry analysis revealed 5-ketogluconic acid, a derivative of gluconic acid as the major organic acid produced by G. diazotrophicus PAl5 cultured with glucose as carbon source. This organic anion may be an important agent that helped in the solubilization of insoluble Zn compounds.

  9. Molecular Mechanisms of Adaptation of the Moderately Halophilic Bacterium Halobacillis halophilus to Its Environment

    Science.gov (United States)

    Hänelt, Inga; Müller, Volker

    2013-01-01

    The capability of osmoadaptation is a prerequisite of organisms that live in an environment with changing salinities. Halobacillus halophilus is a moderately halophilic bacterium that grows between 0.4 and 3 M NaCl by accumulating both chloride and compatible solutes as osmolytes. Chloride is absolutely essential for growth and, moreover, was shown to modulate gene expression and activity of enzymes involved in osmoadaptation. The synthesis of different compatible solutes is strictly salinity- and growth phase-dependent. This unique hybrid strategy of H. halophilus will be reviewed here taking into account the recently published genome sequence. Based on identified genes we will speculate about possible scenarios of the synthesis of compatible solutes and the uptake of potassium ion which would complete our knowledge of the fine-tuned osmoregulation and intracellular osmolyte balance in H. halophilus. PMID:25371341

  10. [Electrooptical properties of soil nitrogen-fixing bacterium Azospirillum brasilense: effect of copper ions].

    Science.gov (United States)

    Ignatov, O V; Kamnev, A A; Markina, L N; Antoniuk, L P; Kolina, M; Ignatov, V V

    2001-01-01

    The effects of copper ions on the uptake of some essential metals in the biomass and the electrooptical properties of cell suspensions of the nitrogen-fixing soil bacterium Azospirillum brasilense sp. 245 were studied. Copper cations were shown to be effectively taken up by the cell biomass from the culture medium. The addition of copper ions increased the rate of uptake of some other metals present in the culture medium. This was accompanied by changes in the electrooptical characteristics of cell suspension as measured within the orienting electric field frequency range of 10 to 10,000 kHz. The effects observed during short-term incubation of A. brasilense in the presence of copper cations were less significant than during long-term incubation. These results can be used for rapid screening of microbial cultures for enhanced efficiency of sorption and uptake of metals.

  11. Geobacter luticola sp. nov., an Fe(III)-reducing bacterium isolated from lotus field mud.

    Science.gov (United States)

    Viulu, Samson; Nakamura, Kohei; Okada, Yurina; Saitou, Sakiko; Takamizawa, Kazuhiro

    2013-02-01

    A novel species of Fe(III)-reducing bacterium, designated strain OSK6(T), belonging to the genus Geobacter, was isolated from lotus field mud in Japan. Strain OSK6(T) was isolated using a solid medium containing acetate, Fe(III)-nitrilotriacetate (NTA) and gellan gum. The isolate is a strictly anaerobic, gram-negative, motile, straight rod-shaped bacterium, 0.6-1.9 µm long and 0.2-0.4 µm wide. The growth of the isolate occurred at 20-40 °C with optima of 30-37 °C and pH 6.5-7.5 in the presence of up to 0.5 g NaCl l(-1). The G+C content of the genomic DNA was determined by HPLC to be 59.7 mol%. The major respiratory quinone was MK-8. The major fatty acids were 16 : 1ω7c and 16 : 0. Strain OSK6(T) was able to grow with Fe(III)-NTA, ferric citrate, amorphous iron (III) hydroxide and nitrate, but not with fumarate, malate or sulfate as electron acceptors. Among examined substrates grown with Fe(III)-NTA, the isolate grew on acetate, lactate, pyruvate and succinate. Analysis of the near full-length 16S rRNA gene sequence revealed that strain OSK6(T) is closely related to Geobacter daltonii and Geobacter toluenoxydans with 95.6 % similarity to the type strains of these species. On the basis of phylogenetic analysis and physiological tests, strain OSK6(T) is described as a representative of a novel species, Geobacter luticola sp. nov.; the type strain is OSK6(T) ( = DSM 24905(T) = JCM 17780(T)).

  12. Co-metabolism of DDT by the newly isolated bacterium, Pseudoxanthomonas sp. wax

    Directory of Open Access Journals (Sweden)

    Guangli Wang

    2010-06-01

    Full Text Available Microbial degradation of 1,1,1-trichloro-2,2-bis(p-chlorophenylethane (DDT is the most promising way to clean up DDT residues found in the environment. In this paper, a bacterium designated as wax, which was capable of co-metabolizing DDT with other carbon sources, was isolated from a long-term DDT-contaminated soil sample by an enrichment culture technique. The new isolate was identified as a member of the Pseudoxanthomonas sp., based on its morphological, physiological and biochemical properties, as well as by 16S rRNA gene analysis. In the presence of 100 mg l-1 glucose, the wax strain could degrade over 95% of the total DDT, at a concentration of 20 mg l-1, in 72 hours, and could degrade over 60% of the total DDT, at a concentration of 100 mg l-1, in 144 hours. The wax strain had the highest degradation efficiency among all of the documented DDT-degrading bacteria. The wax strain could efficiently degrade DDT at temperatures ranging from 20 to 37ºC, and with initial pH values ranging from 7 to 9. The bacterium could also simultaneously co-metabolize 1,1-dichloro-2,2-bis(p-chlorophenylethane (DDD, 2,2-bis(p-chlorophenyl-1,1-dichlorethylene (DDE, and other organochlorine compounds. The wax strain could also completely remove 20 mg kg-1 of DDT from both sterile and non-sterile soils in 20 days. This study demonstrates the significant potential use of Pseudoxanthomonas sp. wax for the bioremediation of DDT in the environment.

  13. Genome Analysis of Thermosulfurimonas dismutans, the First Thermophilic Sulfur-Disproportionating Bacterium of the Phylum Thermodesulfobacteria

    Science.gov (United States)

    Mardanov, Andrey V.; Beletsky, Alexey V.; Kadnikov, Vitaly V.; Slobodkin, Alexander I.; Ravin, Nikolai V.

    2016-01-01

    Thermosulfurimonas dismutans S95T, isolated from a deep-sea hydrothermal vent is the first bacterium of the phylum Thermodesulfobacteria reported to grow by the disproportionation of elemental sulfur, sulfite, or thiosulfate with carbon dioxide as the sole carbon source. In contrast to its phylogenetically close relatives, which are dissimilatory sulfate-reducers, T. dismutans is unable to grow by sulfate respiration. The features of this organism and its 2,1 Mb draft genome sequence are described in this report. Genome analysis revealed that the T. dismutans genome contains the set of genes for dissimilatory sulfate reduction including ATP sulfurylase, the AprA and B subunits of adenosine-5′-phosphosulfate reductase, and dissimilatory sulfite reductase. The oxidation of elemental sulfur to sulfite could be enabled by APS reductase-associated electron transfer complex QmoABC and heterodisulfide reductase. The genome also contains several membrane-linked molybdopterin oxidoreductases that are thought to be involved in sulfur metabolism as subunits of thiosulfate, polysulfide, or tetrathionate reductases. Nitrate could be used as an electron acceptor and reduced to ammonium, as indicated by the presence of periplasmic nitrate and nitrite reductases. Autotrophic carbon fixation is enabled by the Wood–Ljungdahl pathway, and the complete set of genes that is required for nitrogen fixation is also present in T. dismutans. Overall, our results provide genomic insights into energy and carbon metabolism of chemolithoautotrophic sulfur-disproportionating bacterium that could be important primary producer in microbial communities of deep-sea hydrothermal vents. PMID:27379079

  14. Bacillus flexus strain As-12, a new arsenic transformer bacterium isolated from contaminated water resources.

    Science.gov (United States)

    Jebeli, Mohammad Ahmadi; Maleki, Afshin; Amoozegar, Mohammad Ali; Kalantar, Enayatollah; Izanloo, Hassan; Gharibi, Fardin

    2017-02-01

    A total of 14 arsenic-resistant bacteria were isolated from an arsenic-contaminated travertine spring water in the central district of Qorveh county, Kurdistan Province, Iran. One of strains designated As-12 was selected for further investigation because of its ability to transform arsenic. The strain was identified by cultural, morphological and biochemical tests, and 16S rRNA gene sequencing. Finally, the growth characteristics of the isolate were investigated in a chemically defined medium which included varied ranges of environmental factors such as pH, temperature and salinity. Moreover, the resistance of this strain to some heavy metals was evaluated. The bacterium was a Gram-positive, endospore-forming with all other characteristics of the genus Bacillus. It revealed maximum similarity at the 16S rRNA gene level with Bacillus flexus. The optimum growth of the strain was observed at 38 °C, pH 9 and 2% salinity. This strain was resistant to heavy metals such as zinc, chromium, lead, nickel, copper, mercuric and cadmium at concentrations of 15 mM, 15.5 mM, 11.5 mM, 12 mM, 11 mM, 5.5 mM, and 1 mM, respectively. The isolated bacterium was able to reduce As (V) to As (III) (about 28%) and oxidize As (III) to As (V) (about 45%) after 48 h of incubation at 37 °C. In conclusion, Bacillus flexus strain As-12, was identified as an arsenic transformer, for the first time.

  15. Enhanced carboxymethylcellulase production by a newly isolated marine bacterium, Cellulophaga lytica LBH-14, using rice bran.

    Science.gov (United States)

    Gao, Wa; Lee, Eun-Jung; Lee, Sang-Un; Li, Jianhong; Chung, Chung-Han; Lee, Jin-Woo

    2012-10-01

    The aim of this work was to establish the optimal conditions for production of carboxymethylcellulase (CMCase) by a newly isolated marine bacterium using response surface methodology (RSM). A microorganism producing CMCase, isolated from seawater, was identified as Cellulophaga lytica based 16S rDNA sequencing and the neighborjoining method. The optimal conditions of rice bran, ammonium chloride, and initial pH of the medium for cell growth were 100.0 g/l, 5.00 g/l, and 7.0, respectively, whereas those for production of CMCase were 79.9 g/l, 8.52 g/l, and 6.1. The optimal concentrations of K2HPO4, NaCl, MgSO4·7H2O, and (NH4)2SO4 for cell growth were 6.25, 0.62, 0.28, and 0.42 g/l, respectively, whereas those for production of CMCase were 3.72, 0.54, 0.70, and 0.34 g/l. The optimal temperature for cell growth and the CMCase production by C. lytica LBH-14 were 35 degrees C and 25 degrees C, respectively. The maximal production of CMCase under optimized condition for 3 days was 110.8 U/ml, which was 5.3 times higher than that before optimization. In this study, rice bran and ammonium chloride were developed as carbon and nitrogen sources for the production of CMCase by C. lytica LBH-14. The time for production of CMCase by a newly isolated marine bacterium with submerged fermentations reduced to 3 days, which resulted in enhanced productivity of CMCase and a decrease in its production cost.

  16. Survival Strategies of the Plant-Associated Bacterium Enterobacter sp. Strain EG16 under Cadmium Stress.

    Science.gov (United States)

    Chen, Yanmei; Chao, Yuanqing; Li, Yaying; Lin, Qingqi; Bai, Jun; Tang, Lu; Wang, Shizhong; Ying, Rongrong; Qiu, Rongliang

    2016-01-04

    Plant-associated bacteria are of great interest because of their potential use in phytoremediation. However, their ability to survive and promote plant growth in metal-polluted soils remains unclear. In this study, a soilborne Cd-resistant bacterium was isolated and identified as Enterobacter sp. strain EG16. It tolerates high external Cd concentrations (Cd(2+) MIC, >250 mg liter(-1)) and is able to produce siderophores and the plant hormone indole-3-acetic acid (IAA), both of which contribute to plant growth promotion. Surface biosorption in this strain accounted for 31% of the total Cd accumulated. The potential presence of cadmium sulfide, shown by energy-dispersive X-ray (EDX) analysis, suggested intracellular Cd binding as a Cd response mechanism of the isolate. Cd exposure resulted in global regulation at the transcriptomic level, with the bacterium switching to an energy-conserving mode by inhibiting energy-consuming processes while increasing the production of stress-related proteins. The stress response system included increased import of sulfur and iron, which become deficient under Cd stress, and the redirection of sulfur metabolism to the maintenance of intracellular glutathione levels in response to Cd toxicity. Increased production of siderophores, responding to Cd-induced Fe deficiency, not only is involved in the Cd stress response systems of EG16 but may also play an important role in promoting plant growth as well as alleviating the Cd-induced inhibition of IAA production. The newly isolated strain EG16 may be a suitable candidate for microbially assisted phytoremediation due to its high resistance to Cd and its Cd-induced siderophore production, which is likely to contribute to plant growth promotion.

  17. Virus-bacterium coupling driven by both turbidity and hydrodynamics in an Amazonian floodplain lake.

    Science.gov (United States)

    Barros, Nathan; Farjalla, Vinicius F; Soares, Maria C; Melo, Rossana C N; Roland, Fábio

    2010-11-01

    The importance of viruses in aquatic ecosystem functioning has been widely described. However, few studies have examined tropical aquatic ecosystems. Here, we evaluated for the first time viruses and their relationship with other planktonic communities in an Amazonian freshwater ecosystem. Coupling between viruses and bacteria was studied, focusing both on hydrologic dynamics and anthropogenic forced turbidity in the system (Lake Batata). Samples were taken during four hydrologic seasons at both natural and impacted sites to count virus-like particles (VLP) and bacteria. In parallel, virus-infected bacteria were identified and quantified by transmission electron microscopy (TEM). Viral abundance ranged from 0.5 × 10⁷ ± 0.2 × 10⁷ VLP ml⁻¹ (high-water season, impacted site) to 1.7 × 10⁷ ± 0.4 × 10⁷ VLP ml⁻¹ (low-water season, natural site). These data were strongly correlated with the bacterial abundance (r² = 0.84; P < 0.05), which ranged from 1.0 × 10⁶ ± 0.5 × 10⁶ cells ml⁻¹ (high water, impacted site) to 3.4 × 10⁶ ± 0.7 × 10⁶ cells ml⁻¹ (low water, natural site). Moreover, the viral abundance was weakly correlated with chlorophyll a, suggesting that most viruses were bacteriophages. TEM quantitative analyses revealed that the frequency of visibly infected cells was 20%, with 10 ± 3 phages per cell section. In general, we found a low virus-bacterium ratio (<7). Both the close coupling between the viral and bacterial abundances and the low virus-bacterium ratio suggest that viral abundance tends to be driven by the reduction of hosts for viral infection. Our results demonstrate that viruses are controlled by biological substrates, whereas in addition to grazing, bacteria are regulated by physical processes caused by turbidity, which affect underwater light distribution and dissolved organic carbon availability.

  18. A central regulator of morphological differentiation in the multicellular bacterium Streptomyces coelicolor.

    Science.gov (United States)

    Nguyen, Kien T; Willey, Joanne M; Nguyen, Liem D; Nguyen, Lieu T; Viollier, Patrick H; Thompson, Charles J

    2002-12-01

    In the multicellular bacterium Streptomyces coelicolor, functions of developmental (bald) genes are required for the biosynthesis of SapB, a hydrophobic peptidic morphogen that facilitates aerial hyphae formation. Here, we show that aerial hyphal growth and SapB biosynthesis could be activated independently from the normal developmental cascade by providing unprogrammed expression of functionally interactive genes within the ram cluster. ramC, ramS and ramR were essential for normal growth of aerial hyphae, and ramR, a response regulator gene, was a key activator of development. The ramR gene restored growth of aerial hyphae and SapB formation in all bald strains tested (albeit only weakly in the bldC mutant), many of which are characterized by physiological defects. Disruption of the ramR gene abolished SapB biosynthesis and severely delayed growth of aerial hyphae. Transcription of ramR was developmentally controlled, and RamR function in vivo depended on its putative phosphorylation site (D53). We identified and mapped RamR targets immediately upstream of the region encoding ramC and ramS, a putative operon. Overexpression of ramR in the wild-type strain increased SapB levels and caused a distinctive wrinkled surface topology. Based on these results, we propose that phenotypes of bald mutations reflect an early stage in the Streptomyces developmental programme similar to the spo0 mutations in the unicellular bacterium Bacillus subtilis, and that RamR has analogies to Spo0A, the Bacillus response regulator that integrates physiological signals before triggering endospore formation.

  19. Genome sequence of the plant growth promoting endophytic bacterium Enterobacter sp. 638.

    Directory of Open Access Journals (Sweden)

    Safiyh Taghavi

    2010-05-01

    Full Text Available Enterobacter sp. 638 is an endophytic plant growth promoting gamma-proteobacterium that was isolated from the stem of poplar (Populus trichocarpaxdeltoides cv. H11-11, a potentially important biofuel feed stock plant. The Enterobacter sp. 638 genome sequence reveals the presence of a 4,518,712 bp chromosome and a 157,749 bp plasmid (pENT638-1. Genome annotation and comparative genomics allowed the identification of an extended set of genes specific to the plant niche adaptation of this bacterium. This includes genes that code for putative proteins involved in survival in the rhizosphere (to cope with oxidative stress or uptake of nutrients released by plant roots, root adhesion (pili, adhesion, hemagglutinin, cellulose biosynthesis, colonization/establishment inside the plant (chemiotaxis, flagella, cellobiose phosphorylase, plant protection against fungal and bacterial infections (siderophore production and synthesis of the antimicrobial compounds 4-hydroxybenzoate and 2-phenylethanol, and improved poplar growth and development through the production of the phytohormones indole acetic acid, acetoin, and 2,3-butanediol. Metabolite analysis confirmed by quantitative RT-PCR showed that, the production of acetoin and 2,3-butanediol is induced by the presence of sucrose in the growth medium. Interestingly, both the genetic determinants required for sucrose metabolism and the synthesis of acetoin and 2,3-butanediol are clustered on a genomic island. These findings point to a close interaction between Enterobacter sp. 638 and its poplar host, where the availability of sucrose, a major plant sugar, affects the synthesis of plant growth promoting phytohormones by the endophytic bacterium. The availability of the genome sequence, combined with metabolome and transcriptome analysis, will provide a better understanding of the synergistic interactions between poplar and its growth promoting endophyte Enterobacter sp. 638. This information can be further

  20. Reduction of chalcogen oxyanions and generation of nanoprecipitates by the photosynthetic bacterium Rhodobacter capsulatus

    Energy Technology Data Exchange (ETDEWEB)

    Borghese, Roberto, E-mail: roberto.borghese@unibo.it [Department of Pharmacy and Biotechnology, University of Bologna (Italy); Baccolini, Chiara; Francia, Francesco [Department of Pharmacy and Biotechnology, University of Bologna (Italy); Sabatino, Piera [Department of Chemistry G. Ciamician, University of Bologna (Italy); Turner, Raymond J. [Department of Biological Sciences, University of Calgary, Calgary, Alberta (Canada); Zannoni, Davide, E-mail: davide.zannoni@unibo.it [Department of Pharmacy and Biotechnology, University of Bologna (Italy)

    2014-03-01

    Graphical abstract: - Highlights: • R. capsulatus cells produce extracellular chalcogens nanoprecipitates when lawsone is present. • Lawsone acts as a redox mediator from reducing equivalents to tellurite and selenite. • Nanoprecipitates production depends on carbon source and requires metabolically active cells. • Te{sup 0} and Se{sup 0} nanoprecipitates are identified by X-ray diffraction (XRD) spectroscopy. - Abstract: The facultative photosynthetic bacterium Rhodobacter capsulatus is characterized in its interaction with the toxic oxyanions tellurite (Te{sup IV}) and selenite (Se{sup IV}) by a highly variable level of resistance that is dependent on the growth mode making this bacterium an ideal organism for the study of the microbial interaction with chalcogens. As we have reported in the past, while the oxyanion tellurite is taken up by R. capsulatus cells via acetate permease and it is reduced to Te{sup 0} in the cytoplasm in the form of splinter-like black intracellular deposits no clear mechanism was described for Se{sup 0} precipitation. Here, we present the first report on the biotransformation of tellurium and selenium oxyanions into extracellular Te{sup 0} and Se{sup 0}nanoprecipitates (NPs) by anaerobic photosynthetically growing cultures of R. capsulatus as a function of exogenously added redox-mediator lawsone, i.e. 2-hydroxy-1,4-naphthoquinone. The NPs formation was dependent on the carbon source used for the bacterial growth and the rate of chalcogen reduction was constant at different lawsone concentrations, in line with a catalytic role for the redox mediator. X-ray diffraction (XRD) analysis demonstrated the Te{sup 0} and Se{sup 0} nature of the nanoparticles.

  1. Draft Genome Sequence of the Soil Bacterium Burkholderia terrae Strain BS001, Which Interacts with Fungal Surface Structures

    DEFF Research Database (Denmark)

    Nazir, Rashid; Hansen, Martin A.; Sorensen, Soren

    2012-01-01

    Burkholderia terrae BS001 is a soil bacterium which was originally isolated from the mycosphere of the ectomycorrhizal fungus Laccaria proxima. It exhibits a range of fungus-interacting traits which reveal its propensity to actively interact at fungal interfaces. Here, we present the approximatel...

  2. Draft Genome Sequence of Lactobacillus delbrueckii subsp. bulgaricus CFL1, a Lactic Acid Bacterium Isolated from French Handcrafted Fermented Milk.

    Science.gov (United States)

    Meneghel, Julie; Dugat-Bony, Eric; Irlinger, Françoise; Loux, Valentin; Vidal, Marie; Passot, Stéphanie; Béal, Catherine; Layec, Séverine; Fonseca, Fernanda

    2016-03-03

    Lactobacillus delbrueckii subsp. bulgaricus (L. bulgaricus) is a lactic acid bacterium widely used for the production of yogurt and cheeses. Here, we report the genome sequence of L. bulgaricus CFL1 to improve our knowledge on its stress-induced damages following production and end-use processes.

  3. Differential proteome and cellular adhesion analyses of the probiotic bacterium Lactobacillus acidophilus NCFM grown on raffinose - an emerging prebiotic

    DEFF Research Database (Denmark)

    Celebioglu, Hasan Ufuk; Hansen, Morten Ejby; Majumder, Avishek

    2016-01-01

    Whole cell and surface proteomes were analyzed together with adhesive properties of the probiotic bacterium Lactobacillus acidophilus NCFM (NCFM) grown on the emerging prebiotic raffinose, exemplifying a synbiotic. Adhesion of NCFM to mucin and intestinal HT-29 cells increased three-fold after...

  4. Draft Genome Sequence of Enterobacter sp. Sa187, an Endophytic Bacterium Isolated from the Desert Plant Indigofera argentea

    Science.gov (United States)

    Lafi, Feras F.; Alam, Intikhab; Geurts, Rene; Bisseling, Ton; Bajic, Vladimir B.

    2017-01-01

    ABSTRACT Enterobacter sp. Sa187 is a plant endophytic bacterium, isolated from root nodules of the desert plant Indigofera argentea, collected from the Jizan region of Saudi Arabia. Here, we report the genome sequence of Sa187, highlighting several genes involved in plant growth–promoting activity and environmental adaption. PMID:28209831

  5. Complete Genome Sequence of Streptococcus salivarius HSISS4, a Human Commensal Bacterium Highly Prevalent in the Digestive Tract

    Science.gov (United States)

    Fontaine, Laetitia; Kleerebezem, Michiel

    2016-01-01

    The human commensal bacterium Streptococcus salivarius plays a major role in the equilibrium of microbial communities of the digestive tract. Here, we report the first complete genome sequence of a Streptococcus salivarius strain isolated from the small intestine, namely, HSISS4. Its circular chromosome comprises 1,903 coding sequences and 2,100,988 nucleotides. PMID:26847886

  6. Life in the cold: a proteomic study of cold-repressed proteins in the antarctic bacterium pseudoalteromonas haloplanktis TAC125.

    Science.gov (United States)

    Piette, Florence; D'Amico, Salvino; Mazzucchelli, Gabriel; Danchin, Antoine; Leprince, Pierre; Feller, Georges

    2011-06-01

    The proteomes expressed at 4°C and 18°C by the psychrophilic Antarctic bacterium Pseudoalteromonas haloplanktis were compared using two-dimensional differential in-gel electrophoresis with special reference to proteins repressed by low temperatures. Remarkably, the major cold-repressed proteins, almost undetectable at 4°C, were heat shock proteins involved in folding assistance.

  7. Genome Sequence of Klebsiella pneumoniae YZUSK-4, a Bacterium Proposed as a Starter Culture for Fermented Meat Products.

    Science.gov (United States)

    Yu, Hai; Yin, Yongqi; Xu, Lin; Yan, Ming; Fang, Weiming; Ge, Qingfeng

    2015-07-23

    Klebsiella pneumoniae strain YZUSK-4, isolated from Chinese RuGao ham, is an efficient branched-chain aminotransferase-producing bacterium that can be used widely in fermented meat products to enhance flavor. The draft genome sequence of strain YZUSK-4 may provide useful genetic information on branched-chain amino acid aminotransferase production and branched-chain amino acid metabolism.

  8. Thermoregulation of N-acyl homoserine lactone-based quorum sensing in the soft rot bacterium Pectobacterium atrosepticum.

    Science.gov (United States)

    Latour, Xavier; Diallo, Stéphanie; Chevalier, Sylvie; Morin, Danièle; Smadja, Bruno; Burini, Jean-François; Haras, Dominique; Orange, Nicole

    2007-06-01

    The psychrotolerant bacterium Pectobacterium atrosepticum produces four N-acyl homoserine lactones under a wide range of temperatures. Their thermoregulation differs from that of the exoenzyme production, described as being under quorum-sensing control. A mechanism involved in this thermoregulation consists of controlling N-acyl homoserine lactones synthase production at a transcriptional level.

  9. Draft Genome Sequence of Limnobacter sp. Strain CACIAM 66H1, a Heterotrophic Bacterium Associated with Cyanobacteria.

    Science.gov (United States)

    da Silva, Fábio Daniel Florêncio; Lima, Alex Ranieri Jerônimo; Moraes, Pablo Henrique Gonçalves; Siqueira, Andrei Santos; Dall'Agnol, Leonardo Teixeira; Baraúna, Anna Rafaella Ferreira; Martins, Luisa Carício; Oliveira, Karol Guimarães; de Lima, Clayton Pereira Silva; Nunes, Márcio Roberto Teixeira; Vianez-Júnior, João Lídio Silva Gonçalves; Gonçalves, Evonnildo Costa

    2016-05-19

    Ecological interactions between cyanobacteria and heterotrophic prokaryotes are poorly known. To improve the genomic studies of heterotrophic bacterium-cyanobacterium associations, the draft genome sequence (3.2 Mbp) of Limnobacter sp. strain CACIAM 66H1, found in a nonaxenic culture of Synechococcus sp. (cyanobacteria), is presented here.

  10. Desulfotomaculum carboxydivorans sp.nov., a novel sulfate-reducing bacterium capable of growth at 100% CO

    NARCIS (Netherlands)

    Parshina, S.N.; Sipma, J.; Nakashimada, Y.; Henstra, A.M.; Smidt, H.; Lysenko, A.M.; Lens, P.N.L.; Lettinga, G.; Stams, A.J.M.

    2005-01-01

    A moderately thermophilic, anaerobic, chemolithoheterotrophic, sulfate-reducing bacterium, strain CO-1-SRBT, was isolated from sludge from an anaerobic bioreactor treating paper mill wastewater. Cells were Gram-positive, motile, spore-forming rods. The temperature range for growth was 30¿68 °C, with

  11. Microbacter margulisiae gen. nov., sp. nov., a novel propionigenic bacterium isolated from sediments of an acid rock drainage pond

    NARCIS (Netherlands)

    Sanchez Andrea, I.; Luis Sanz, J.; Stams, A.J.M.

    2014-01-01

    A novel anaerobic propionigenic bacterium, strain ADRIT, was isolated from sediment of an acid rock drainage environment (Tinto River, Spain). Cells were small (0.4-0.6 x 1-1.7 µm), non-motile and non-spore forming rods. Cells possessed a Gram-negative cell wall structure and were vancomycin resista

  12. Desulfurella amilsii sp. nov., a novel acidotolerant sulfur-respiring bacterium isolated from sediments of the Tinto River

    NARCIS (Netherlands)

    Florentino de Souza Silva, Anna; Brienza, C.; Stams, A.J.M.; Sanchez Andrea, I.

    2016-01-01

    A novel acidotolerant and moderately thermophilic sulfur-reducing bacterium was isolated from sediments of the Tinto River (Spain), an extremely acidic environment. Strain TR1T stains Gram-negative, is obligately anaerobic, non-spore forming and motile. Cells are short rods (1.5-2 by 0.5-0.7 µm),app

  13. 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.

  14. Antioxidants keep the potentially probiotic but highly oxygen-sensitive human gut bacterium Faecalibacterium prausnitzii alive at ambient air

    NARCIS (Netherlands)

    Khan, M. Tanweer; van Dijl, Jan Maarten; Harmsen, Hermie J M

    2014-01-01

    The beneficial human gut microbe Faecalibacterium prausnitzii is a 'probiotic of the future' since it produces high amounts of butyrate and anti-inflammatory compounds. However, this bacterium is highly oxygen-senstive, making it notoriously difficult to cultivate and preserve. This has so far precl

  15. Extraction of DNA from orange juice and detection of bacterium Candidatus Liberibacter asiaticus by real-time PCR

    Science.gov (United States)

    Orange juice processed from Huanglongbing (HLB) affected fruit is often associated with bitter taste and/or off-flavor. HLB disease in Florida is associated with Candidatus Liberibacter asiaticus (CLas), a phloem limited bacterium. The current standard to confirm CLas for citrus trees is to take sam...

  16. Multiple, stochastic factors can determine acquisition success of the foregut-borne bacterium, Xylella fastidiosa, by a sharpshooter vector

    Science.gov (United States)

    Xylella fastidiosa is a phytopathogenic foregut-borne bacterium whose vectors are sharpshooter leafhoppers. Despite several decades of study, the mechanisms of transmission (acquisition and inoculation) of X. fastidiosa still are not fully understood. Studies of the inoculation mechanism depend upon...

  17. Complete Genome of Enterobacteriaceae Bacterium Strain FGI 57, a Strain Associated with Leaf-Cutter Ant Fungus Gardens.

    Science.gov (United States)

    Aylward, Frank O; Tremmel, Daniel M; Bruce, David C; Chain, Patrick; Chen, Amy; Walston Davenport, Karen; Detter, Chris; Han, Cliff S; Han, James; Huntemann, Marcel; Ivanova, Natalia N; Kyrpides, Nikos C; Markowitz, Victor; Mavrommatis, Kostas; Nolan, Matt; Pagani, Ioanna; Pati, Amrita; Pitluck, Sam; Deshpande, Shweta; Goodwin, Lynne; Woyke, Tanja; Currie, Cameron R

    2013-01-01

    The Enterobacteriaceae bacterium strain FGI 57 was isolated from a fungus garden of the leaf-cutter ant Atta colombica. Analysis of its single 4.76-Mbp chromosome will shed light on community dynamics and plant biomass degradation in ant fungus gardens.

  18. Characterization of cytochrome P450 monooxygenase CYP154H1 from the thermophilic soil bacterium Thermobifida fusca

    NARCIS (Netherlands)

    Schallmey, Anett; den Besten, Gijs; Teune, Ite G. P.; Kembaren, Roga F.; Janssen, Dick B.

    2011-01-01

    Cytochrome P450 monooxygenases are valuable biocatalysts due to their ability to hydroxylate unactivated carbon atoms using molecular oxygen. We have cloned the gene for a new cytochrome P450 monooxygenase, named CYP154H1, from the moderately thermophilic soil bacterium Thermobifida fusca. The enzym

  19. Towards the entire proteome of the model bacterium Bacillus subtilis by gel-based and gel-free approaches

    NARCIS (Netherlands)

    Wolff, Susanne; Antelmann, Haike; Albrecht, Dirk; Becher, Doerte; Bernhardt, Joerg; Bron, Sierd; Buettner, Knut; van Dijl, Jan Maarten; Eymann, Christine; Otto, Andreas; Tam, Le Thi; Hecker, Michael

    2007-01-01

    With the emergence of mass spectrometry in protein science and the availability of complete genome sequences, proteomics has gone through a rapid development. The soil bacterium Bacillus subtilis, as one of the first DNA sequenced species, represents a model for Gram-positive bacteria and its proteo

  20. Complete Genome Sequence of Nitrosomonas cryotolerans ATCC 49181, a Phylogenetically Distinct Ammonia-Oxidizing Bacterium Isolated from Arctic Waters.

    Science.gov (United States)

    Rice, Marlen C; Norton, Jeanette M; Stein, Lisa Y; Kozlowski, Jessica; Bollmann, Annette; Klotz, Martin G; Sayavedra-Soto, Luis; Shapiro, Nicole; Goodwin, Lynne A; Huntemann, Marcel; Clum, Alicia; Pillay, Manoj; Varghese, Neha; Mikhailova, Natalia; Palaniappan, Krishna; Ivanova, Natalia; Mukherjee, Supratim; Reddy, T B K; Yee Ngan, Chew; Daum, Chris; Kyrpides, Nikos; Woyke, Tanja

    2017-03-16

    Nitrosomonas cryotolerans ATCC 49181 is a cold-tolerant marine ammonia-oxidizing bacterium isolated from seawater collected in the Gulf of Alaska. The high-quality complete genome contains a 2.87-Mbp chromosome and a 56.6-kbp plasmid. Chemolithoautotrophic modules encoding ammonia oxidation and CO2 fixation were identified.

  1. Complete genome sequence of Nitrosomonas sp. Is79, an ammonia oxidizing bacterium adapted to low ammonium concentrations

    NARCIS (Netherlands)

    Bollmann, A.; Sedlacek, C.J.; Norton, J.; Laanbroek, H.J.; Suwa, Y.; Stein, L.Y.; Klotz, M.G.; Arp, D.; Sayavedra-Soto, L.; Lu, M.; Bruce, D.; Detter, C.; Tapia, R.; Han, J.; Woyke, T.; Lucas, S.; Pitluck, S.; Pennacchio, L.; Nolan, M.; Land, M.L.; Huntemann, M.; Deshpande, S.; Han, C.; Chen, A.; Kyrpides, N.; Mavromatis, K.; Markowitz, V.; Szeto, E.; Ivanova, N.; Mikhailova, N.; Pagani, I.; Pati, A.; Peters, L.; Ovchinnikova, G.; Goodwin, L.

    2013-01-01

    Nitrosomonas sp. Is79 is a chemolithoautotrophic ammonia-oxidizing bacterium that belongs to the family Nitrosomonadaceae within the phylum Proteobacteria. Ammonia oxidation is the first step of nitrification, an important process in the global nitrogen cycle ultimately resulting in the production o

  2. Growth and survival of the fish pathogenic bacterium, Flavobacterium columnare, in tilapia mucus and porcine gastric mucin

    Science.gov (United States)

    Flavobacterium columnare is an economically important gram negative bacterium that infects most freshwater farmed fish worldwide. Flavobacterium columnare colonizes the skin and gills of fish in the initial steps of pathogenesis. The fish’s surface is coated with mucus made up of high molecular we...

  3. Marinimicrobium haloxylanilyticum sp. nov., a new moderately halophilic, polysaccharide-degrading bacterium isolated from Great Salt Lake, Utah

    DEFF Research Database (Denmark)

    Fogh Møller, Mette; Kjeldsen, Kasper Urup; Ingvorsen, Kjeld

    2010-01-01

    A new moderately halophilic, strictly aerobic, Gram-negative bacterium, strain SX15T, was isolated from hypersaline surface sediment of the southern arm of Great Salt Lake (Utah, USA). The strain grew on a number of carbohydrates and carbohydrate polymers such as xylan, starch, carboxymethyl...

  4. Draft Genome Sequence of Enterobacter sp. Sa187, an Endophytic Bacterium Isolated from the Desert Plant Indigofera argentea

    KAUST Repository

    Lafi, Feras Fawzi

    2017-02-17

    Enterobacter sp. Sa187 is a plant endophytic bacterium, isolated from root nodules of the desert plant Indigofera argentea, collected from the Jizan region of Saudi Arabia. Here, we report the genome sequence of Sa187, highlighting several genes involved in plant growth–promoting activity and environmental adaption.

  5. Methanol coneversion by a novel thermophilic homoacetogenic bacterium Moorella mulderi sp.nov. isolated from a bioreactor

    NARCIS (Netherlands)

    Balk, M.; Weijma, J.; Friedrich, M.W.; Stams, A.J.M.

    2003-01-01

    A thermophilic, anaerobic, spore-forming bacterium (strain TMS) was isolated from a thermophilic bioreactor operated at 65 degreesC with methanol as the energy source. Cells were gram-positive straight rods, 0.4-0.6 mum x 2-8 mum, growing as single cells or in pairs. The temperature range for growth

  6. Draft Genome Sequence of Bacillus pseudalcaliphilus PN-137T (DSM 8725), an Alkaliphilic Halotolerant Bacterium Isolated from Garden Soils.

    Science.gov (United States)

    Wang, Jie-Ping; Liu, Bo; Liu, Guo-Hong; Xiao, Rong-Feng; Zheng, Xue-Fang; Shi, Huai; Ge, Ci-Bin

    2015-01-01

    Bacillus pseudalcaliphilus PN-137(T) (DSM 8725) is a Gram-positive, spore-forming, alkaliphilic, and halotolerant bacterium. Here, we report the 4.49-Mb genome sequence of B. pseudalcaliphilus PN-137(T), which will accelerate the application of this alkaliphile and provide useful information for genomic taxonomy and phylogenomics of Bacillus-like bacteria.

  7. Complete Genome Sequence of the Bacterium Aalborg_AAW-1, Representing a Novel Family within the Candidate Phylum SR1

    DEFF Research Database (Denmark)

    Dueholm, Morten Simonsen; Albertsen, Mads; Stokholm-Bjerregaard, Mikkel;

    2015-01-01

    Here, we present the complete genome sequence of the candidate phylum SR1 bacterium Aalborg_AAW-1. Its 16S rRNA gene is only 85.5% similar to that of the closest relative, RAAC1_SR1, and the genome of Aalborg_AAW-1 consequently represents the first of a novel family within the candidate phylum SR1....

  8. Quantitative analysis of growth and volatile fatty acid production by the anaerobic ruminal bacterium Megasphaera elsdenii T81

    Science.gov (United States)

    Megaspheara elsdenii T81 grew on either DL-lactate or D-glucose at similar rates (0.85 per h), but displayed major differences in the fermentation of these substrates. Lactate was fermented at up to 210-mM concentration to yield acetic, propionic, butyric, and valeric acids. The bacterium was able t...

  9. Evidence of carbon fixation pathway in a bacterium from candidate phylum SBR1093 revealed with genomic analysis.

    Science.gov (United States)

    Wang, Zhiping; Guo, Feng; Liu, Lili; Zhang, Tong

    2014-01-01

    Autotrophic CO2 fixation is the most important biotransformation process in the biosphere. Research focusing on the diversity and distribution of relevant autotrophs is significant to our comprehension of the biosphere. In this study, a draft genome of a bacterium from candidate phylum SBR1093 was reconstructed with the metagenome of an industrial activated sludge. Based on comparative genomics, this autotrophy may occur via a newly discovered carbon fixation path, the hydroxypropionate-hydroxybutyrate (HPHB) cycle, which was demonstrated in a previous work to be uniquely possessed by some genera from Archaea. This bacterium possesses all of the thirteen enzymes required for the HPHB cycle; these enzymes share 30∼50% identity with those in the autotrophic species of Archaea that undergo the HPHB cycle and 30∼80% identity with the corresponding enzymes of the mixotrophic species within Bradyrhizobiaceae. Thus, this bacterium might have an autotrophic growth mode in certain conditions. A phylogenetic analysis based on the 16S rRNA gene reveals that the phylotypes within candidate phylum SBR1093 are primarily clustered into 5 clades with a shallow branching pattern. This bacterium is clustered with phylotypes from organically contaminated environments, implying a demand for organics in heterotrophic metabolism. Considering the types of regulators, such as FnR, Fur, and ArsR, this bacterium might be a facultative aerobic mixotroph with potential multi-antibiotic and heavy metal resistances. This is the first report on Bacteria that may perform potential carbon fixation via the HPHB cycle, thus may expand our knowledge of the distribution and importance of the HPHB cycle in the biosphere.

  10. Genome Sequence of the Plant Growth Promoting Endophytic Bacterium Enterobacter sp. 638

    Energy Technology Data Exchange (ETDEWEB)

    Taghavi, S.; van der Lelie, D.; Hoffman, A.; Zhang, Y.-B.; Walla, M. D.; Vangronsveld, J.; Newman, L.; Monchy, S.

    2010-05-13

    Enterobacter sp. 638 is an endophytic plant growth promoting gamma-proteobacterium that was isolated from the stem of poplar (Populus trichocarpa x deltoides cv. H11-11), a potentially important biofuel feed stock plant. The Enterobacter sp. 638 genome sequence reveals the presence of a 4,518,712 bp chromosome and a 157,749 bp plasmid (pENT638-1). Genome annotation and comparative genomics allowed the identification of an extended set of genes specific to the plant niche adaptation of this bacterium. This includes genes that code for putative proteins involved in survival in the rhizosphere (to cope with oxidative stress or uptake of nutrients released by plant roots), root adhesion (pili, adhesion, hemagglutinin, cellulose biosynthesis), colonization/establishment inside the plant (chemiotaxis, flagella, cellobiose phosphorylase), plant protection against fungal and bacterial infections (siderophore production and synthesis of the antimicrobial compounds 4-hydroxybenzoate and 2-phenylethanol), and improved poplar growth and development through the production of the phytohormones indole acetic acid, acetoin, and 2,3-butanediol. Metabolite analysis confirmed by quantitative RT-PCR showed that, the production of acetoin and 2,3-butanediol is induced by the presence of sucrose in the growth medium. Interestingly, both the genetic determinants required for sucrose metabolism and the synthesis of acetoin and 2,3-butanediol are clustered on a genomic island. These findings point to a close interaction between Enterobacter sp. 638 and its poplar host, where the availability of sucrose, a major plant sugar, affects the synthesis of plant growth promoting phytohormones by the endophytic bacterium. The availability of the genome sequence, combined with metabolome and transcriptome analysis, will provide a better understanding of the synergistic interactions between poplar and its growth promoting endophyte Enterobacter sp. 638. This information can be further exploited to

  11. Enhanced bactericidal potency of nanoliposomes by modification of the fusion activity between liposomes and bacterium

    Directory of Open Access Journals (Sweden)

    Ma YF

    2013-06-01

    Full Text Available Yufan Ma,1 Zhao Wang,1,2 Wen Zhao,1 Tingli Lu,1 Rutao Wang,1,2 Qibing Mei,1 Tao Chen1–3 1Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, People's Republic of China; 2Shaanxi Liposome Research Center, Xi'an, Shaanxi, People's Republic of China; 3Xi'an Libang Pharmaceuticals Co, Ltd, Xi'an, People's Republic of China Background: Pseudomonas aeruginosa represents a good model of antibiotic resistance. These organisms have an outer membrane with a low level of permeability to drugs that is often combined with multidrug efflux pumps, enzymatic inactivation of the drug, or alteration of its molecular target. The acute and growing problem of antibiotic resistance of Pseudomonas to conventional antibiotics made it imperative to develop new liposome formulations to overcome these mechanisms, and investigate the fusion between liposome and bacterium. Methods: The rigidity, stability and charge properties of phospholipid vesicles were modified by varying the cholesterol, 1,2-dioleoyl-sn-glycero-3-phosphatidylethanolamine (DOPE, and negatively charged lipids 1,2-dimyristoyl-sn-glycero-3-phosphoglycerol sodium salt (DMPG, 1,2-dimyristoyl-sn-glycero-3-phopho-L-serine sodium salt (DMPS, 1,2-dimyristoyl-sn-glycero-3-phosphate monosodium salt (DMPA, nature phosphatidylserine sodium salt from brain and nature phosphatidylinositol sodium salt from soybean concentrations in liposomes. Liposomal fusion with intact bacteria was monitored using a lipid-mixing assay. Results: It was discovered that the fluid liposomes-bacterium fusion is not dependent on liposomal size and lamellarity. A similar degree of fusion was observed for liposomes with a particle size from 100 to 800 nm. The fluidity of liposomes is an essential pre-request for liposomes fusion with bacteria. Fusion was almost completely inhibited by incorporation of cholesterol into fluid liposomes. The increase in the

  12. Production of polyhydroxybutyrate by the marine photosynthetic bacterium Rhodovulum sulfidophilum P5

    Institute of Scientific and Technical Information of China (English)

    CAI Jinling; WEI Ying; ZHAO Yupeng; PAN Guanghua; WANG Guangce

    2012-01-01

    The effects of different NaCl concentrations,nitrogen sources,carbon sources,and carbon to nitrogen molar ratios on biomass accumulation and polyhydroxybutyrate (PHB) production were studied in batch cultures of the marine photosynthetic bacterium Rhodovulum sulfidophilum P5 under aerobic-dark conditions.The results show that the accumulation of PHB in strain P5 is a growth-associated process.Strain P5 had maximum biomass and PHB accumulation at 2%-3% NaCl,suggesting that the bacterium can maintain growth and potentially produce PHB at natural seawater salinity.In the nitrogen source test,the maximum biomass accumulation (8.10±0.09 g/L) and PHB production (1.11±0.13 g/L and 14.62%±2.25%of the cell dry weight) were observed when peptone and ammonium chloride were used as the sole nitrogen source.NH+4-N was better for PHB production than other nitrogen sources.In the carbon source test,the maximum biomass concentration (7.65±0.05 g/L) was obtained with malic acid as the sole carbon source,whereas the maximum yield of PHB (5.03±0.18 g/L and 66.93%±1.69% of the cell dry weight) was obtained with sodium pyruvate as the sole carbon source.In the carbon to nitrogen ratios test,sodium pyruvate and ammonium chloride were selected as the carbon and nitrogen sources,respectively.The best carbon to nitrogen molar ratio for biomass accumulation (8.77±0.58 g/L) and PHB production (6.07±0.25 g/L and 69.25%±2.05% of the cell dry weight) was 25.The results provide valuable data on the production of PHB by R.sulfidophilum P5 and further studies are on-going for best cell growth and PHB yield.

  13. Complete genome sequence of the filamentous anoxygenic phototrophic bacterium Chloroflexus aurantiacus

    Directory of Open Access Journals (Sweden)

    Larimer Frank W

    2011-06-01

    Full Text Available Abstract Background Chloroflexus aurantiacus is a thermophilic filamentous anoxygenic phototrophic (FAP bacterium, and can grow phototrophically under anaerobic conditions or chemotrophically under aerobic and dark conditions. According to 16S rRNA analysis, Chloroflexi species are the earliest branching bacteria capable of photosynthesis, and Cfl. aurantiacus has been long regarded as a key organism to resolve the obscurity of the origin and early evolution of photosynthesis. Cfl. aurantiacus contains a chimeric photosystem that comprises some characters of green sulfur bacteria and purple photosynthetic bacteria, and also has some unique electron transport proteins compared to other photosynthetic bacteria. Methods The complete genomic sequence of Cfl. aurantiacus has been determined, analyzed and compared to the genomes of other photosynthetic bacteria. Results Abundant genomic evidence suggests that there have been numerous gene adaptations/replacements in Cfl. aurantiacus to facilitate life under both anaerobic and aerobic conditions, including duplicate genes and gene clusters for the alternative complex III (ACIII, auracyanin and NADH:quinone oxidoreductase; and several aerobic/anaerobic enzyme pairs in central carbon metabolism and tetrapyrroles and nucleic acids biosynthesis. Overall, genomic information is consistent with a high tolerance for oxygen that has been reported in the growth of Cfl. aurantiacus. Genes for the chimeric photosystem, photosynthetic electron transport chain, the 3-hydroxypropionate autotrophic carbon fixation cycle, CO2-anaplerotic pathways, glyoxylate cycle, and sulfur reduction pathway are present. The central carbon metabolism and sulfur assimilation pathways in Cfl. aurantiacus are discussed. Some features of the Cfl. aurantiacus genome are compared with those of the Roseiflexus castenholzii genome. Roseiflexus castenholzii is a recently characterized FAP bacterium and phylogenetically closely related to Cfl

  14. Bacillus halosaccharovorans sp. nov., a moderately halophilic bacterium from a hypersaline lake.

    Science.gov (United States)

    Mehrshad, Maliheh; Amoozegar, Mohammad Ali; Didari, Maryam; Bagheri, Maryam; Fazeli, Seyed Abolhassan Shahzadeh; Schumann, Peter; Spröer, Cathrin; Sánchez-Porro, Cristina; Ventosa, Antonio

    2013-08-01

    A novel Gram-stain-positive, moderately halophilic bacterium, designated strain E33(T), was isolated from water of the hypersaline lake Aran-Bidgol in Iran and characterized taxonomically using a polyphasic approach. Cells of strain E33(T) were motile rods and produced ellipsoidal endospores at a central or subterminal position in swollen sporangia. Strain E33(T) was a strictly aerobic bacterium, catalase- and oxidase-positive. The strain was able to grow at NaCl concentrations of 0.5-25 % (w/v), with optimum growth occurring at 5-15 % (w/v) NaCl. The optimum temperature and pH for growth were 40 °C and pH 7.5-8.0, respectively. On the basis of 16S rRNA gene sequence analysis, strain E33(T) was shown to belong to the genus Bacillus within the phylum Firmicutes and showed the closest phylogenetic similarity with the species Bacillus niabensis 4T19(T) (99.2 %), Bacillus herbersteinensis D-1-5a(T) (97.3 %) and Bacillus litoralis SW-211(T) (97.2 %). The DNA G+C content of the type strain of the novel species was 42.6 mol%. The major cellular fatty acids of strain E33(T) were anteiso-C15 : 0 and iso-C15 : 0, and the polar lipid pattern consisted of diphosphatidylglycerol, phosphatidylglycerol, two unknown glycolipids, an unknown lipid and an unknown phospholipid. The isoprenoid quinones were MK-7 (97 %), MK-6 (2 %) and MK-8 (0.5 %). The peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. All these features confirm the placement of isolate E33(T) within the genus Bacillus. DNA-DNA hybridization experiments revealed low levels of relatedness between strain E33(T) and Bacillus niabensis IBRC-M 10590(T) (22 %), Bacillus herbersteinensis CCM 7228(T) (38 %) and Bacillus litoralis DSM 16303(T) (19 %). On the basis of polyphasic evidence from this study, a novel species of the genus Bacillus, Bacillus halosaccharovorans sp. nov. is proposed, with strain E33(T) (= IBRC-M 10095(T) = DSM 25387(T)) as the type strain.

  15. Bacillus persicus sp. nov., a halophilic bacterium from a hypersaline lake.

    Science.gov (United States)

    Didari, Maryam; Amoozegar, Mohammad Ali; Bagheri, Maryam; Mehrshad, Maliheh; Schumann, Peter; Spröer, Cathrin; Sánchez-Porro, Cristina; Ventosa, Antonio

    2013-04-01

    A novel gram-positive, slightly halophilic bacterium, designated strain B48(T), was isolated from soil around the hypersaline lake Aran-Bidgol in Iran and characterized taxonomically using a polyphasic approach. Cells of strain B48(T) were non-motile rods and produced ellipsoidal endospores at a central or subterminal position in swollen sporangia. Strain B48(T) was a strictly aerobic bacterium, catalase- and oxidase-positive. The strain was able to grow at NaCl concentrations of 0.5-10.0 % (w/v), with optimum growth occurring at 2.5 % (w/v) NaCl. The optimum temperature and pH for growth were 35 °C and pH 7.5-8.0, respectively. On the basis of 16S rRNA gene sequence analysis, strain B48(T) was shown to belong to the genus Bacillus within the phylum Firmicutes and showed the closest phylogenetic similarity to the species Bacillus foraminis CV53(T) (97.4 %) and Bacillus purgationiresistens DS22(T) (96.9 %). The DNA G+C content of this new isolate was 40.1 mol%. The major cellular fatty acids of strain B48(T) were iso-C15 : 0 and anteiso-C15 : 0, and its polar lipid pattern consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an aminophospholipid and two unknown phospholipids. The only quinone present was menaquinone 7 (MK-7). The peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. All these features confirm the placement of isolate B48(T) within the genus Bacillus. DNA-DNA hybridization experiments revealed a low level of relatedness between strain B48(T) and Bacillus foraminis IBRC-M 10625(T) (8.1 %). On the basis of polyphasic evidence from this study, a new species of the genus Bacillus, Bacillus persicus sp. nov., is proposed, with strain B48(T) ( = IBRC-M 10115(T) = DSM 25386(T) = CECT 8001(T)) as the type strain.

  16. Computational prediction of essential genes in an unculturable endosymbiotic bacterium, Wolbachia of Brugia malayi

    Directory of Open Access Journals (Sweden)

    Carlow Clotilde KS

    2009-11-01

    Full Text Available Abstract Background Wolbachia (wBm is an obligate endosymbiotic bacterium of Brugia malayi, a parasitic filarial nematode of humans and one of the causative agents of lymphatic filariasis. There is a pressing need for new drugs against filarial parasites, such as B. malayi. As wBm is required for B. malayi development and fertility, targeting wBm is a promising approach. However, the lifecycle of neither B. malayi nor wBm can be maintained in vitro. To facilitate selection of potential drug targets we computationally ranked the wBm genome based on confidence that a particular gene is essential for the survival of the bacterium. Results wBm protein sequences were aligned using BLAST to the Database of Essential Genes (DEG version 5.2, a collection of 5,260 experimentally identified essential genes in 15 bacterial strains. A confidence score, the Multiple Hit Score (MHS, was developed to predict each wBm gene's essentiality based on the top alignments to essential genes in each bacterial strain. This method was validated using a jackknife methodology to test the ability to recover known essential genes in a control genome. A second estimation of essentiality, the Gene Conservation Score (GCS, was calculated on the basis of phyletic conservation of genes across Wolbachia's parent order Rickettsiales. Clusters of orthologous genes were predicted within the 27 currently available complete genomes. Druggability of wBm proteins was predicted by alignment to a database of protein targets of known compounds. Conclusion Ranking wBm genes by either MHS or GCS predicts and prioritizes potentially essential genes. Comparison of the MHS to GCS produces quadrants representing four types of predictions: those with high confidence of essentiality by both methods (245 genes, those highly conserved across Rickettsiales (299 genes, those similar to distant essential genes (8 genes, and those with low confidence of essentiality (253 genes. These data facilitate

  17. A Novel Treatment Protects Chlorella at Commercial Scale from the Predatory Bacterium Vampirovibrio chlorellavorus

    Science.gov (United States)

    Ganuza, Eneko; Sellers, Charles E.; Bennett, Braden W.; Lyons, Eric M.; Carney, Laura T.

    2016-01-01

    The predatory bacterium, Vampirovibrio chlorellavorus, can destroy a Chlorella culture in just a few days, rendering an otherwise robust algal crop into a discolored suspension of empty cell walls. Chlorella is used as a benchmark for open pond cultivation due to its fast growth. In nature, V. chlorellavorus plays an ecological role by controlling this widespread terrestrial and freshwater microalga, but it can have a devastating effect when it attacks large commercial ponds. We discovered that V. chlorellavorus was associated with the collapse of four pilot commercial-scale (130,000 L volume) open-pond reactors. Routine microscopy revealed the distinctive pattern of V. chlorellavorus attachment to the algal cells, followed by algal cell clumping, culture discoloration and ultimately, growth decline. The “crash” of the algal culture coincided with increasing proportions of 16s rRNA sequencing reads assigned to V. chlorellavorus. We designed a qPCR assay to predict an impending culture crash and developed a novel treatment to control the bacterium. We found that (1) Chlorella growth was not affected by a 15 min exposure to pH 3.5 in the presence of 0.5 g/L acetate, when titrated with hydrochloric acid and (2) this treatment had a bactericidal effect on the culture (2-log decrease in aerobic counts). Therefore, when qPCR results indicated a rise in V. chlorellavorus amplicons, we found that the pH-shock treatment prevented the culture crash and doubled the productive longevity of the culture. Furthermore, the treatment could be repeatedly applied to the same culture, at the beginning of at least two sequential batch cycles. In this case, the treatment was applied preventively, further increasing the longevity of the open pond culture. In summary, the treatment reversed the infection of V. chlorellavorus as confirmed by observations of bacterial attachment to Chlorella cells and by detection of V. chlorellavorus by 16s rRNA sequencing and qPCR assay. The p

  18. Microbial control of the production of hydrogen sulfide by sulfate-reducing bacteria.

    Science.gov (United States)

    Montgomery, A D; McLnerney, M J; Sublette, K L

    1990-03-01

    A sulfide-resistant ctrain of Thiobacillus denitrificans, strain F, prevented the accumulation of sulfide by Desulfovibrio desulfuricans when both organisms were grown in liquid medium or in Berea sandstone cores. The wild-type strain of T. denitrificans did not prevent the accumulation of sulfide produced by D. desulfuricans. Strain F also prevented the accumulation of sulfide by a mixed population of sulfate-reducing bacteria enriched from an oil field brine. Fermentation balances showed that strain F stoichiometrically oxidized the sulfide produced by D. desulfuricans and the oil field brine enrichment to sulfate. These data suggest that strain F would be effective in controlling sulfide production in oil reservoirs and other environments.

  19. Two genes encoding new carotenoid-modifying enzymes in the green sulfur bacterium Chlorobium tepidum.

    Science.gov (United States)

    Maresca, Julia A; Bryant, Donald A

    2006-09-01

    The green sulfur bacterium Chlorobium tepidum produces chlorobactene as its primary carotenoid. Small amounts of chlorobactene are hydroxylated by the enzyme CrtC and then glucosylated and acylated to produce chlorobactene glucoside laurate. The genes encoding the enzymes responsible for these modifications of chlorobactene, CT1987, and CT0967, have been identified by comparative genomics, and these genes were insertionally inactivated in C. tepidum to verify their predicted function. The gene encoding chlorobactene glucosyltransferase (CT1987) has been named cruC, and the gene encoding chlorobactene lauroyltransferase (CT0967) has been named cruD. Homologs of these genes are found in the genomes of all sequenced green sulfur bacteria and filamentous anoxygenic phototrophs as well as in the genomes of several nonphotosynthetic bacteria that produce similarly modified carotenoids. The other bacteria in which these genes are found are not closely related to green sulfur bacteria or to one another. This suggests that the ability to synthesize modified carotenoids has been a frequently transferred trait.

  20. Genes involved in the biosynthesis of photosynthetic pigments in the purple sulfur photosynthetic bacterium Thiocapsa roseopersicina.

    Science.gov (United States)

    Kovács, Akos T; Rákhely, Gábor; Kovács, Kornél L

    2003-06-01

    A pigment mutant strain of the purple sulfur photosynthetic bacterium Thiocapsa roseopersicina BBS was isolated by plasposon mutagenesis. Nineteen open reading frame, most of which are thought to be genes involved in the biosynthesis of carotenoids, bacteriochlorophyll, and the photosynthetic reaction center, were identified surrounding the plasposon in a 22-kb-long chromosomal locus. The general arrangement of the photosynthetic genes was similar to that in other purple photosynthetic bacteria; however, the locations of a few genes occurring in this region were unusual. Most of the gene products showed the highest similarity to the corresponding proteins in Rubrivivax gelatinosus. The plasposon was inserted into the crtD gene, likely inactivating crtC as well, and the carotenoid composition of the mutant strain corresponded to the aborted spirilloxanthin pathway. Homologous and heterologous complementation experiments indicated a conserved function of CrtC and CrtD in the purple photosynthetic bacteria. The crtDC and crtE genes were shown to be regulated by oxygen, and a role of CrtJ in aerobic repression was suggested.

  1. Inhella inkyongensis gen. nov., sp. nov., a new freshwater bacterium in the order Burkholderiales.

    Science.gov (United States)

    Song, Jaeho; Oh, Hyun-Myung; Lee, Jung-Sook; Woo, Seung-Buhm; Cho, Jang-Cheon

    2009-01-01

    A freshwater bacterium, designated IMCC1713(T), was isolated from a highly eutrophic artificial pond. Cells of the strain were Gram-negative, chemoheterotrophic, polybeat and obligately aerobic short rods that were motile with a single polar flagellum. The 16S rRNA gene sequence similarity analysis showed that the novel strain was most closely related to the species Roseateles depolymerans (96.3%), Mitsuaria chitosanitabida (96.2%), Ideonella dechloratans (96.2%), and Pelomonas saccharophila (96.1%) in the Sphaerotilus-Leptothrix group within the order Burkholderiales. Phylogenetic trees based on 16S rRNA gene sequences indicated that the isolate formed an independent monophyletic clade within the order Burkholderiales. The relatively low DNA G+C content (57.4 mol%), together with several phenotypic characteristics, differentiated the novel strain from other members of the Sphaerotilus-Leptothrix group. From the taxonomic data, therefore, the strain should be classified as a novel genus and species, for which the name Inhella inkyongensis gen. nov., sp. nov. is proposed. The type strain of the proposed species is strain IMCC1713(T) (=KCTC 12791(T)=NBRC 103252(T)=CCUG 54308(T)).

  2. The structures of glycolipids isolated from the highly thermophilic bacterium Thermus thermophilus Samu-SA1.

    Science.gov (United States)

    Leone, Serena; Molinaro, Antonio; Lindner, Buko; Romano, Ida; Nicolaus, Barbara; Parrilli, Michelangelo; Lanzetta, Rosa; Holst, Otto

    2006-08-01

    Thermophiles constitute a class of microorganisms able to grow at extremely elevated temperatures. Some of these species are classified as Gram-negative bacteria, because of the presence of an outer membrane in the cell envelope, which is located on the top of a thick murein layer. Unlike typical Gram-negative bacteria, the outer membranes of Thermus species are not composed of lipopolysaccharides but of peculiar glycolipids (GL), whose structures seem to be strictly involved in the adaptation to high temperatures. In this work, the complete structures of the major GL components from the cell envelope of the thermophilic bacterium Thermus thermophilus Samu-SA1 are presented. Protocols conventionally adopted for Gram-negative bacteria were used, and, for the first time, GL from Thermus were analyzed in their native form. Two GL and one phosphoglycolipid (PGL) were detected and characterized. The two GL, analyzed by nuclear magnetic resonance (NMR) spectroscopy and electrospray ionization Fourier transform ion cyclotron resonance (ESI FT-ICR) mass spectrometry, possessed the same tetrasaccharide structure linked to a glycerol unit or, alternatively, to a long-chain diol. Moreover, a PGL from Thermus was characterized for the first time, in which N-glyceroyl-heptadecaneamine was present. These molecules are chemically related to other GL from thermophile bacteria, in which they play a crucial role in the adaptation of cell membranes to heat.

  3. Construction of the astaxanthin biosynthetic pathway in a methanotrophic bacterium Methylomonas sp. strain 16a.

    Science.gov (United States)

    Ye, Rick W; Yao, Henry; Stead, Kristen; Wang, Tao; Tao, Luan; Cheng, Qiong; Sharpe, Pamela L; Suh, Wonchul; Nagel, Eva; Arcilla, Dennis; Dragotta, Dominic; Miller, Edward S

    2007-04-01

    Methylomonas sp. strain 16a is an obligate methanotrophic bacterium that uses methane or methanol as the sole carbon source. An effort was made to engineer this organism for astaxanthin production. Upon expressing the canthaxanthin gene cluster under the control of the native hps promoter in the chromosome, canthaxanthin was produced as the main carotenoid. Further conversion to astaxanthin was carried out by expressing different combinations of crtW and crtZ genes encoding the beta-carotenoid ketolase and hydroxylase. The carotenoid intermediate profile was influenced by the copy number of these two genes under the control of the hps promoter. Expression of two copies of crtZ and one copy of crtW led to the accumulation of a large amount of the mono-ketolated product adonixanthin. On the other hand, expression of two copies of crtW and one copy of crtZ resulted in the presence of non-hydroxylated carotenoid canthaxanthin and the mono-hydroxylated adonirubin. Production of astaxanthin as the predominant carotenoid was obtained in a strain containing two complete sets of carotenoid biosynthetic genes. This strain had an astaxanthin titer ranging from 1 to 2.4 mg g(-1) of dry cell biomass depending on the growth conditions. More than 90% of the total carotenoid was astaxanthin, of which the majority was in the form of E-isomer. This result indicates that it is possible to produce astaxanthin with desirable properties in methanotrophs through genetic engineering.

  4. Role of extracellular compounds in Cd-sequestration relative to Cd uptake by bacterium Sinorhizobium meliloti

    Energy Technology Data Exchange (ETDEWEB)

    Slaveykova, Vera I., E-mail: vera.slaveykova@epfl.c [Environmental Biophysical Chemistry, IIE-ENAC, Ecole Polytechnique Federale de Lausanne (EPFL), Station 2, CH-1015 Lausanne (Switzerland); Parthasarathy, Nalini [Department of Inorganic, Analytic and Applied Chemistry, University of Geneva, Sciences II, 30 Quai Ernest Ansermet, 1211 Geneva 4 (Switzerland); Dedieu, Karine; Toescher, Denis [Environmental Biophysical Chemistry, IIE-ENAC, Ecole Polytechnique Federale de Lausanne (EPFL), Station 2, CH-1015 Lausanne (Switzerland)

    2010-08-15

    The role of bacterially derived compounds in Cd(II) complexation and uptake by bacterium Sinorhizobium meliloti wild type (WT) and genetically modified ExoY-mutant, deficient in exopolysaccharide production, was explored combining chemical speciation measurements and assays with living bacteria. Obtained results demonstrated that WT- and ExoY-strains excreted siderophores in comparable amounts, while WT-strain produced much higher amount of exopolysaccharides and less exoproteins. An evaluation of Cd(II) distribution in bacterial suspensions under short term exposure conditions, showed that most of the Cd is bound to bacterial surface envelope, including Cd bound to the cell wall and to the attached extracellular polymeric substances. However, the amount of Cd bound to the dissolved extracellular compounds increases at high Cd(II) concentrations. The implications of these findings to more general understanding of the Cd(II) fate and cycling in the environment is discussed. - Bacterial excreted extracellular compounds play minor role in Cd(II) sequestration relative to bacteria.

  5. Expression and Characterization of Recombinant Thermostable Alkaline Phosphatase from a Novel Thermophilic Bacterium Thermus thermophilus XM

    Institute of Scientific and Technical Information of China (English)

    Jianbo LI; Limei XU; Feng YANG

    2007-01-01

    A gene (tap) encoding a thermostable alkaline phosphatase from the thermophilic bacterium Thermus thermophilus XM was cloned and sequenced. It is 1506 bp long and encodes a protein of 501 amino acid residues with a calculated molecular mass of 54.7 kDa. Comparison of the deduced amino acid sequence with other alkaline phosphatases showed that the regions in the vicinity of the phosphorylation site and metal binding sites are highly conserved. The recombinant thermostable alkaline phosphatase was expressed as a His6-tagged fusion protein in Escherichia coli and its enzymatic properties were characterized after purification. The pH and temperature optima for the recombinant thermostable alkaline phosphatases activity were pH 12 and 75 ℃. As expected, the enzyme displayed high thermostability, retaining more than 50% activity after incubating for 6 h at 80 ℃. Its catalytic function was accelerated in the presence of 0.1 mM Co2+, Fe2+, Mg2+, or Mn2+ but was strongly inhibited by 2.0 mM Fe2+. Under optimal conditions, the Michaelis constant (Km) for cleavage of p-nitrophenyl-phosphate was 0.034 mM. Although it has much in common with other alkaline phosphatases, the recombinant thermostable alkaline phosphatase possesses some unique features, such as high optimal pH and good thermostability.

  6. Isolation and identification of moderately thermophilic acidophilic iron-oxidizing bacterium and its bioleaching characterization

    Institute of Scientific and Technical Information of China (English)

    ZENG Wei-min; WU Chang-bin; ZHANG Ru-bing; HU Pei-lei; QIU Guan-zhou; GU Guo-hua; ZHOU Hong-bo

    2009-01-01

    A moderately thermophilic acidophilic iron-oxidizing bacterium ZW-1 was isolated from Dexing mine, Jiangxi Province, China. The morphological, biochemical and physiological characteristics, 16S rRNA sequence and bioleaching characterization of strain ZW-1 were studied. The optimum growth temperature is 48 ℃, and the optimum initial pH is 1.9. The strain can grow autotrophically by using ferrous iron or elemental sulfur as sole energy sources. The strain is also able to grow heterotrophically by using peptone and yeast extract powder, but not glucose. The cell density of strain ZW-1 can reach up to 1.02×108 /mL with addition of 0.4 g/L peptone. A phylogenetic tree was constructed by comparing with the published 16S rRNA sequences of the relative bacteria species. In the phylogenetic tree, strain ZW-1 is closely relative to Sulfobacilus acidophilus with more than 99% sequence similarity. The results of bioleaching experiments indicate that the strain could oxidize Fe2+ efficiently, and the maximum oxidizing rate is 0.295 g/(L·h). It could tolerate high concentration of Fe3+ and Cu2+ (35 g/L and 25 g/L, respectively). After 20 d, 44.6% of copper is extracted from chalcopyrite by using strain ZW-1 as inocula.

  7. Exopolysaccharides play a role in the swarming of the benthic bacterium Pseudoalteromonas sp. SM9913

    Directory of Open Access Journals (Sweden)

    Ang eLiu

    2016-04-01

    Full Text Available Most marine bacteria secrete exopolysaccharide (EPS, which is important for bacterial survival in the marine environment. However, it is still unclear whether the self-secreted EPS is involved in marine bacterial motility. Here we studied the role of EPS in the lateral flagella-driven swarming motility of benthic bacterium Pseudoalteromonas sp. SM9913 (SM9913 by a comparison of wild SM9913 and ΔepsT, an EPS synthesis defective mutant. Reduction of EPS production in ΔepsT did not affect the growth rate or the swimming motility, but significantly decreased the swarming motility on a swarming plate, suggesting that the EPS may play a role in SM9913 swarming. However, the expression and assembly of lateral flagella in ΔepsT were not affected. Instead, ΔepsT had a different swarming behavior from wild SM9913. The swarming of ΔepsT did not have an obvious rapid swarming period, and its rate became much lower than that of wild SM9913 after 35 h incubation. An addition of surfactin or SM9913 EPS on the surface of the swarming plate could rescue the swarming level. These results indicate that the self-secreted EPS is required for the swarming of SM9913. This study widens our understanding of the function of the EPS of benthic bacteria.

  8. The complete genome sequence of the plant growth-promoting bacterium Pseudomonas sp. UW4.

    Science.gov (United States)

    Duan, Jin; Jiang, Wei; Cheng, Zhenyu; Heikkila, John J; Glick, Bernard R

    2013-01-01

    The plant growth-promoting bacterium (PGPB) Pseudomonas sp. UW4, previously isolated from the rhizosphere of common reeds growing on the campus of the University of Waterloo, promotes plant growth in the presence of different environmental stresses, such as flooding, high concentrations of salt, cold, heavy metals, drought and phytopathogens. In this work, the genome sequence of UW4 was obtained by pyrosequencing and the gaps between the contigs were closed by directed PCR. The P. sp. UW4 genome contains a single circular chromosome that is 6,183,388 bp with a 60.05% G+C content. The bacterial genome contains 5,423 predicted protein-coding sequences that occupy 87.2% of the genome. Nineteen genomic islands (GIs) were predicted and thirty one complete putative insertion sequences were identified. Genes potentially involved in plant growth promotion such as indole-3-acetic acid (IAA) biosynthesis, trehalose production, siderophore production, acetoin synthesis, and phosphate solubilization were determined. Moreover, genes that contribute to the environmental fitness of UW4 were also observed including genes responsible for heavy metal resistance such as nickel, copper, cadmium, zinc, molybdate, cobalt, arsenate, and chromate. Whole-genome comparison with other completely sequenced Pseudomonas strains and phylogeny of four concatenated "housekeeping" genes (16S rRNA, gyrB, rpoB and rpoD) of 128 Pseudomonas strains revealed that UW4 belongs to the fluorescens group, jessenii subgroup.

  9. Asticcacaulis taihuensis sp. nov., a novel stalked bacterium isolated from Taihu Lake, China.

    Science.gov (United States)

    Liu, Zhi-Pei; Wang, Bao-Jun; Liu, Shuang-Jiang; Liu, Ying-Hao

    2005-05-01

    A novel stalked bacterium, designated strain T3-B7(T), was isolated from sediment of Taihu Lake, Jiangsu Province, China, and its taxonomy was studied by using a polyphasic approach. Cell morphology, physiological and biochemical properties, and polar lipids indicated that strain T3-B7(T) represented a member of the genus Asticcacaulis. Based on 16S rRNA gene sequence similarity analysis, strain T3-B7(T) was found to be phylogenetically related to Asticcacaulis biprosthecium DSM 4723(T) (98.5 %) and Asticcacaulis excentricus DSM 4724(T) (95.0 %), but could be differentiated from these two species on the basis of the number and position of prosthecae, assimilation of sugars, nitrate reduction and tolerance to NaCl. Levels of DNA-DNA relatedness of strain T3-B7(T) to A. biprosthecium DSM 4723(T) and A. excentricus DSM 4724(T) were 37.1 and 18.0 %, respectively. The G + C content of strain T3-B7(T) was 59 mol% (T(m)). It is concluded that strain T3-B7(T) represents a novel species of the genus Asticcacaulis, for which the name of Asticcacaulis taihuensis sp. nov. is proposed. The type strain is T3-B7(T) (=AS 1.3431(T) = JCM 12463(T)).

  10. A novel multienzyme complex from a newly isolated facultative anaerobic bacterium, Paenibacillus sp. TW1.

    Science.gov (United States)

    Tachaapaikoon, C; Kyu, K L; Pason, P; Ratanakhanockchai, K

    2012-06-01

    A multienzyme complex from newly isolated Paenibacillus sp. TW1 was purified from pellet-bound enzyme preparations by elution with 0.25% sucrose and 1.0% triethylamine (TEA), ultrafiltration and Sephacryl S-400 gel filtration chromatography. The purified multienzyme complex showed a single protein band on non-denaturing polyacrylamide gel electrophoresis (native-PAGE). The high molecular mass of the purified multienzyme complex was approximately 1,950 kDa. The complex consisted of xylanase and cellulase activities as the major and minor enzyme subunits, respectively. The complex appeared as at least 18 protein bands on sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and as 15 xylanases and 6 cellulases on zymograms. The purified multienzyme complex contained xylanase, α-L-arabinofuranosidase, carboxymethyl cellulase (CMCase), avicelase and cellobiohydrolase. The complex could effectively hydrolyze corn hulls, corncobs and sugarcane bagasse. These results indicate that the multienzyme complex that is produced by this bacterium is a large, novel xylanolytic-cellulolytic enzyme complex.

  11. Devosia lucknowensis sp. nov., a bacterium isolated from hexachlorocyclohexane (HCH) contaminated pond soil.

    Science.gov (United States)

    Dua, Ankita; Malhotra, Jaya; Saxena, Anjali; Khan, Fazlurrahman; Lal, Rup

    2013-10-01

    Strain L15(T), a Gram-negative, motile, orange colored bacterium was isolated from pond soil in the surrounding area of a hexachlorocyclohexane (HCH) dump site at Ummari village in Lucknow, India. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain L15(T) belongs to the family Hyphomicrobiaceae in the order Rhizobiales. Strain L15(T) showed highest 16S rRNA gene sequence similarity to Devosia chinhatensis IPL18(T) (98.0%). Chemotaxonomic data revealed that the major fatty acids were summed feature 8 (C18:1 ω7c and/or C18:1 ω6c), C18:1 ω7c 11-methyl, C16:0 and C18:0. The major polar lipids of strain L15(T) were diphosphatidylglycerol and phosphatidylglycerol. The genomic DNA G+C content of strain L15(T) was 59.8%. Polyamine profile showed the presence of sym-homospermidine with traces of putrescine. Ubiquinone Q-10 was the major respiratory quinone present. Based on these data, strain L15(T) (=CCM 7977(T) =DSM 25398(T)) was classified as a type strain of a novel species, for which the name Devosia lucknowensis sp. nov. is proposed.

  12. In vitro effects on intestinal bacterium of physalins from Physalis alkekengi var. Francheti.

    Science.gov (United States)

    Li, Xinli; Zhang, Cuili; Wu, Dachang; Tang, Li; Cao, Xuejiao; Xin, Yi

    2012-12-01

    Intestinal probiotic bacterium stimulative activity-guided fractionation of Physalis alkekengi var. Francheti calyces extract resulted in the isolation of four new physalins (1-4). Their structures were elucidated as 5α, 6β-dihydroxy-25, 27-dihydro-7-deoxyphysalin A (1), 5α, 6β-dihydroxyphysalin R (2), 3β-hydroxy-2-hydrophysalin A (3) and 5α-hydroxy-7-dehydro-25, 27-dihydro-7-deoxyneophysalin A (4) by UV, MS, 1D and 2D NMR spectroscopy. Growth curves of Lactobacillus delbrueckii and Escherichia coli for different total physalins extract (TPE) concentrations were tested in vitro. Middle concentrations (0.78mg/mL-1.56mg/mL) of TPE promoted the growth of L. delbrueckii, but all inhibited the growth of E. coli, in which the bacteriostatic activity increased while TPE concentration increases. Physalins showed stimulative effects on the growth of probiotic bacteria but inhibitory effects on the growth of pathogenic bacteria.

  13. Sulfonamide inhibition studies of the β-carbonic anhydrase from the pathogenic bacterium Vibrio cholerae.

    Science.gov (United States)

    Del Prete, Sonia; Vullo, Daniela; De Luca, Viviana; Carginale, Vincenzo; Ferraroni, Marta; Osman, Sameh M; AlOthman, Zeid; Supuran, Claudiu T; Capasso, Clemente

    2016-03-01

    The genome of the pathogenic bacterium Vibrio cholerae encodes for three carbonic anhydrases (CAs, EC 4.2.1.1) belonging to the α-, β- and γ-classes. VchCA, the α-CA from this species was investigated earlier, whereas the β-class enzyme, VchCAβ was recently cloned, characterized kinetically and its X-ray crystal structure reported by this group. Here we report an inhibition study with sulfonamides and one sulfamate of this enzyme. The best VchCAβ inhibitors were deacetylated acetazolamide and methazolamide and hydrochlorothiazide, which showed inhibition constants of 68.2-87.0nM. Other compounds, with medium potency against VchCAβ, (KIs in the range of 275-463nM), were sulfanilamide, metanilamide, sulthiame and saccharin whereas the clinically used agents such as acetazolamide, methazolamide, ethoxzolamide, dorzolamide, zonisamide and celecoxib were micromolar inhibitors (KIs in the range of 4.51-8.57μM). Identification of potent and possibly selective inhibitors of VchCA and VchCAβ over the human CA isoforms, may lead to pharmacological tools useful for understanding the physiological role(s) of this under-investigated enzymes.

  14. Bacillus nitroreducens sp. nov., a humus-reducing bacterium isolated from a compost.

    Science.gov (United States)

    Guo, Junhui; Wang, Yue Qiang; Yang, Guiqin; Chen, Yunqi; Zhou, Shungui; Zhao, Yong; Zhuang, Li

    2016-05-01

    A Gram-staining-positive, facultative anaerobic, motile and rod-shaped bacterium, designated GSS08(T), was isolated from a windrow compost pile and characterized by means of a polyphasic approach. Growth occurred with 0-4 % (w/v) NaCl (optimum 1 %), at pH 6.5-9.5 (optimum pH 7.5) and at 20-45 °C (optimum 37 °C). Anaerobic growth occurred with anthraquinone-2,6-disulphonate, fumarate and NO3 (-) as electron acceptor. The main respiratory quinone was MK-7. The predominant polar lipids were diphosphatidylglycerol and phosphatidylethanolamine. The major fatty acids (>5 %) were iso-C15:0 (43.1 %), anteiso-C15:0 (27.4 %) and iso-C16:0 (8.3 %). The DNA G + C content was 39.6 mol%. The phylogenetic analysis based on 16S rRNA gene sequences revealed that strain GSS08(T) formed a phyletic lineage with the type strain of Bacillus humi DSM 16318(T) with a high sequence similarity of 97.5 %, but it displayed low sequence similarity with other valid species in the genus Bacillus (Bacillus nitroreducens sp. nov. is proposed. The type strain is GSS08(T) (=KCTC 33699(T) = MCCC 1K01091(T)).

  15. Two New Xylanases with Different Substrate Specificities from the Human Gut Bacterium Bacteroides intestinalis DSM 17393

    KAUST Repository

    Hong, Pei-Ying

    2014-01-24

    Xylan is an abundant plant cell wall polysaccharide and is a dominant component of dietary fiber. Bacteria in the distal human gastrointestinal tract produce xylanase enzymes to initiate the degradation of this complex heteropolymer. These xylanases typically derive from glycoside hydrolase (GH) families 10 and 11; however, analysis of the genome sequence of the xylan-degrading human gut bacterium Bacteroides intestinalis DSM 17393 revealed the presence of two putative GH8 xylanases. In the current study, we demonstrate that the two genes encode enzymes that differ in activity. The xyn8A gene encodes an endoxylanase (Xyn8A), and rex8A encodes a reducing-end xylose-releasing exo-oligoxylanase (Rex8A). Xyn8A hydrolyzed both xylopentaose (X5) and xylohexaose (X6) to a mixture of xylobiose (X2) and xylotriose (X3), while Rex8A hydrolyzed X3 through X6 to a mixture of xylose (X1) and X2. Moreover, rex8A is located downstream of a GH3 gene (xyl3A) that was demonstrated to exhibit β-xylosidase activity and would be able to further hydrolyze X2 to X1. Mutational analyses of putative active site residues of both Xyn8A and Rex8A confirm their importance in catalysis by these enzymes. Recent genome sequences of gut bacteria reveal an increase in GH8 Rex enzymes, especially among the Bacteroidetes, indicating that these genes contribute to xylan utilization in the human gut.

  16. Isolation and characterization of a marine bacterium producing protease from Chukchi Sea, Arctic

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A Gram negative bacterium Ar/W/b/75°25'N/1 producing extracellular alkaline protease was isolated from surface water of latitude 75°25'N, and longitude 162°25'W in Chukchi sea, Arctic. The strain can grow at the temperature range from 7℃ to 30℃, and grow better at 30(℃. It can not grow at 40℃. Keeping certain salinity concentration in medium is necessary for cell growth. It grows well in medium containing salinity concentration from 0. 5 % to 10 % sodium chloride. Glucose, sucrose and soluble starch can be utilized by the strain, among which glucose is the optimal carbon source. Peptone is the optimal organic nitrogen source for cell growth and protease producing, and ammonium nitrate is the optimal inorganic nitrogen source.About 75.7% of total protease of the strain are extracellular enzyme. Optimal temperature for proteolytic activity is at 40℃. Protease of the strain keeps stable below 40℃, and shows high proteolytic activity within the pH range from 7 to 11.

  17. Genome shuffling of marine derived bacterium Nocardia sp. ALAA 2000 for improved ayamycin production.

    Science.gov (United States)

    El-Gendy, Mervat M A; El-Bondkly, Ahmed M A

    2011-05-01

    Genome shuffling is a recent development in microbiology. The advantage of this technique is that genetic changes can be made in a microorganism without knowing its genetic background. Genome shuffling was applied to the marine derived bacterium Nocardia sp. ALAA 2000 to achieve rapid improvement of ayamycin production. The initial mutant population was generated by treatment with ethyl methane sulfonate (EMS) combined with UV irradiation of the spores, resulting in an improved population (AL/11, AL/136, AL/213 and AL/277) producing tenfold (150 μg/ml) more ayamycin than the original strain. These mutants were used as the starting strains for three rounds of genome shuffling and after each round improved strains were screened and selected based on their ayamycin productivity. The population after three rounds of genome shuffling exhibited an improved ayamycin yield. Strain F3/22 yielded 285 μg/ml of ayamycin, which was 19-fold higher than that of the initial strain and 1.9-fold higher than the mutants used as the starting point for genome shuffling. We evaluated the genetic effect of UV + EMS-mutagenesis and three rounds of genome shuffling on the nucleotide sequence by random amplified polymorphic DNA (RAPD) analysis. Many differences were noticed in mutant and recombinant strains compared to the wild type strain. These differences in RAPD profiles confirmed the presence of genetic variations in the Nocardia genome after mutagenesis and genome shuffling.

  18. Characterisation of the LH2 spectral variants produced by the photosynthetic purple sulphur bacterium Allochromatium vinosum.

    Science.gov (United States)

    Carey, Anne-Marie; Hacking, Kirsty; Picken, Nichola; Honkanen, Suvi; Kelly, Sharon; Niedzwiedzki, Dariusz M; Blankenship, Robert E; Shimizu, Yuuki; Wang-Otomo, Zheng-Yu; Cogdell, Richard J

    2014-11-01

    This study systematically investigated the different types of LH2 produced by Allochromatium (Alc.) vinosum, a photosynthetic purple sulphur bacterium, in response to variations in growth conditions. Three different spectral forms of LH2 were isolated and purified, the B800-820, B800-840 and B800-850 LH2 types, all of which exhibit an unusual split 800 peak in their low temperature absorption spectra. However, it is likely that more forms are also present. Relatively more B800-820 and B800-840 are produced under low light conditions, while relatively more B800-850 is produced under high light conditions. Polypeptide compositions of the three different LH2 types were determined by a combination of HPLC and TOF/MS. The B800-820, B800-840 and B800-850 LH2 types all have a heterogeneous polypeptide composition, containing multiple types of both α and β polypeptides, and differ in their precise polypeptide composition. They all have a mixed carotenoid composition, containing carotenoids of the spirilloxanthin series. In all cases the most abundant carotenoid is rhodopin; however, there is a shift towards carotenoids with a higher conjugation number in LH2 complexes produced under low light conditions. CD spectroscopy, together with the polypeptide analysis, demonstrates that these Alc. vinosum LH2 complexes are more closely related to the LH2 complex from Phs. molischianum than they are to the LH2 complexes from Rps. acidophila.

  19. Biohydrogen Production by the Thermophilic Bacterium Caldicellulosiruptor saccharolyticus: Current Status and Perspectives.

    Science.gov (United States)

    Bielen, Abraham A M; Verhaart, Marcel R A; van der Oost, John; Kengen, Servé W M

    2013-01-17

    Caldicellulosiruptor saccharolyticus is one of the most thermophilic cellulolytic organisms known to date. This Gram-positive anaerobic bacterium ferments a broad spectrum of mono-, di- and polysaccharides to mainly acetate, CO2 and hydrogen. With hydrogen yields approaching the theoretical limit for dark fermentation of 4 mol hydrogen per mol hexose, this organism has proven itself to be an excellent candidate for biological hydrogen production. This review provides an overview of the research on C. saccharolyticus with respect to the hydrolytic capability, sugar metabolism, hydrogen formation, mechanisms involved in hydrogen inhibition, and the regulation of the redox and carbon metabolism. Analysis of currently available fermentation data reveal decreased hydrogen yields under non-ideal cultivation conditions, which are mainly associated with the accumulation of hydrogen in the liquid phase. Thermodynamic considerations concerning the reactions involved in hydrogen formation are discussed with respect to the dissolved hydrogen concentration. Novel cultivation data demonstrate the sensitivity of C. saccharolyticus to increased hydrogen levels regarding substrate load and nitrogen limitation. In addition, special attention is given to the rhamnose metabolism, which represents an unusual type of redox balancing. Finally, several approaches are suggested to improve biohydrogen production by C. saccharolyticus.

  20. Identification and characterization of Clostridium paraputrificum M-21, a chitinolytic, mesophilic and hydrogen-producing bacterium.

    Science.gov (United States)

    Evvyernie, D; Yamazaki, S; Morimoto, K; Karita, S; Kimura, T; Sakka, K; Ohmiya, K

    2000-01-01

    A strictly anaerobic, mesophilic and chitinolytic bacterial strain, M-21, was isolated from a soil sample collected from Mie University campus and identified as Clostridium paraputrificum based on morphological and physiological characteristics, and 16S rRNA sequence analysis. C. paraputrificum M-21 utilized chitin and N-acetyl-D-glucosamine (GlcNAc), a constituent monosaccharide of chitin, to produce a large amount of gas along with acetic acid and propionic acid as major fermentation products. Hydrogen and carbon dioxide accounted for 65% and 35% of the gas evolved, respectively. The conditions for 1 l batch culture of C. paraputrificum, including pH of the medium, incubation temperature and agitation speed, were optimized for hydrogen production with GlcNAc as the carbon source. The bacterium grew rapidly on GlcNAc with a doubling time of around 30 min, and produced hydrogen gas with a yield of 1.9 mol H2/mol GlcNAc under the following cultivation conditions: initial medium pH of 6.5, incubation temperature of 45 degrees C, agitation speed of 250 rpm, and working volume of 50% of the fermentor. The dry cell weight harvested from this culture was 2.0 g/l.

  1. Enterobacter siamensis sp. nov., a transglutaminase-producing bacterium isolated from seafood processing wastewater in Thailand.

    Science.gov (United States)

    Khunthongpan, Suwannee; Bourneow, Chaiwut; H-Kittikun, Aran; Tanasupawat, Somboon; Benjakul, Soottawat; Sumpavapol, Punnanee

    2013-01-01

    A novel strain of Enterobacter, C2361(T), a Gram-negative, non-spore-forming, rod-shaped and facultative anaerobic bacterium with the capability to produce transglutaminase, was isolated from seafood processing wastewater collected from a treatment pond of a seafood factory in Songkhla Province, Thailand. Phylogenetic analyses and phenotypic characteristics, including chemotaxonomic characteristics, showed that the strain was a member of the genus Enterobacter. The 16S rRNA gene sequence similarities between strain C2361(T) and Enterobacter cloacae subsp. cloacae ATCC 13047(T) and Enterobacter cloacae subsp. dissolvens LMG 2683(T) were 97.5 and 97.5%, respectively. Strain C2361(T) showed a low DNA-DNA relatedness with the above-mentioned species. The major fatty acids were C16:0, C17:0cyclo and C14:0. The DNA G+C content was 53.0 mol%. On the basis of the polyphasic evidence gathered in this study, it should be classified as a novel species of the genus Enterobacter for which the name Enterobacter siamensis sp. nov. is proposed. The type strain is C2361(T) (= KCTC 23282(T) = NBRC 107138(T)).

  2. Degradation of Reactive Black 5 dye by a newly isolated bacterium Pseudomonas entomophila BS1.

    Science.gov (United States)

    Khan, Sana; Malik, Abdul

    2016-03-01

    The textile and dye industries are considered as one of the major sources of environmental pollution. The present study was conducted to investigate the degradation of the azo dye Reactive Black 5 (RB 5) using a bacterium isolated from soil samples collected around a textile industry. The bacterial strain BS1 capable of degrading RB 5 was isolated and identified as Pseudomonas entomophila on the basis of 16S rDNA sequencing. The effects of different parameters on the degradation of RB 5 were studied to find out the optimal conditions required for maximum degradation, which was 93% after 120 h of incubation. Static conditions with pH in the range of 5-9 and a temperature of 37 °C were found to be optimum for degrading RB 5. Enzyme assays demonstrated that P. entomophila possessed azoreductase, which played an important role in degradation. The enzyme was dependent on flavin mononucleotide and NADH for its activity. Furthermore, a possible degradation pathway of the dye was proposed through gas chromatography - mass spectrometry analysis, which revealed that the metabolic products were naphthalene-1,2-diamine and 4-(methylsulfonyl) aniline. Thus the ability of this indigenous bacterial isolate for simultaneous decolorization and degradation of the azo dye signifies its potential application for treatment of industrial wastewaters containing azo dyes.

  3. The endosymbiotic bacterium Wolbachia induces resistance to dengue virus in Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    Guowu Bian

    2010-04-01

    Full Text Available Genetic strategies that reduce or block pathogen transmission by mosquitoes have been proposed as a means of augmenting current control measures to reduce the growing burden of vector-borne diseases. The endosymbiotic bacterium Wolbachia has long been promoted as a potential vehicle for introducing disease-resistance genes into mosquitoes, thereby making them refractory to the human pathogens they transmit. Given the large overlap in tissue distribution and intracellular localization between Wolbachia and dengue virus in mosquitoes, we conducted experiments to characterize their interactions. Our results show that Wolbachia inhibits viral replication and dissemination in the main dengue vector, Aedes aegypti. Moreover, the virus transmission potential of Wolbachia-infected Ae. aegypti was significantly diminished when compared to wild-type mosquitoes that did not harbor Wolbachia. At 14 days post-infection, Wolbachia completely blocked dengue transmission in at least 37.5% of Ae. aegypti mosquitoes. We also observed that this Wolbachia-mediated viral interference was associated with an elevated basal immunity and increased longevity in the mosquitoes. These results underscore the potential usefulness of Wolbachia-based control strategies for population replacement.

  4. Identification a Novel Raw-Starch-Degrading-α-Amylase from a Tropical Marine Bacterium

    Directory of Open Access Journals (Sweden)

    Zeily Nurachman

    2010-01-01

    Full Text Available Problem statement: Bacteria from the surface of the tropical marine hard coral Acropora sp. were screened for producing raw-starch-degrading-á-amylase. Approach: Based on its 16s rDNA sequence, a bacterium that produced the highest amylolitic activity was identified as Bacillus amyloliquifaciens ABBD. The bacterial isolate secreted a á-amylase extracellularly and then the enzyme was partially purified by ammonium sulfate precipitation followed by anion exchange chromatography. Results: Electrophoresis results both SDS-PAGE and native PAGE suggested that the enzyme was a heterodimeric protein (97 kDa consisting of 45 and 55 kDa subunits. The á-amylase had an optimum pH of 7.0 and temperature of 60°C. More than 80% activity of the enzyme was retained under high salt conditions (up to 20% NaCl. The enzyme remained stable at 50°C for 1 h. Starch hydrolysis by the enzyme at 70°C yielded oligosaccharides (G2-G4 and at room temperature yielded glucose/maltose (G1 and G2. Conclusion: The B. amyloliquifaciens ABBD á-amylase was capable of degrading various raw starch granules from corn, rice, cassava and sago at room temperature.

  5. A mycorrhiza helper bacterium enhances ectomycorrhizal and endomycorrhizal symbiosis of Australian Acacia species.

    Science.gov (United States)

    Duponnois, R; Plenchette, C

    2003-04-01

    The aims of this study were to test the effects of a mycorrhiza helper bacterium (MHB), Pseudomonas monteilii strain HR13 on the mycorrhization of (1) an Australian Acacia, A. holosericea, by several ectomycorrhizal fungi or one endomycorrhizal fungus Glomus intraradices, and (2) several Australian Acacia species by Pisolithus alba strain IR100 under glasshouse conditions. Bacterial inoculant HR13 significantly promoted ectomycorrhizal colonization for all the Acacia species, from 45.8% ( A. mangium) to 70.3% ( A. auriculiformis). A stimulating effect of HR13 on the ectomycorrhizal establishment was recorded with all the fungal isolates (strains of Pisolithus and Scleroderma). The same effect of bacteria on the frequency of endomycorrhizal colonization of A. holosericea seedlings by G. intraradices with vesicles and hyphae frequencies was recorded. The stimulation of saprophytic fungal growth by MHB is usually the main mechanism that could explain this bacterial effect on mycorrhizal establishment. MHB could stimulate the production of phenolic compounds such as hypaphorine and increase the aggressiveness of the fungal symbiont. However, no significant effect of MHB on fungal growth was recorded with Scleroderma isolates under axenic conditions but positive bacterial effects were observed with Pisolithus strains. From a practical viewpoint, it appears that MHB could stimulate the mycorrhizal colonization of Australian Acacia species with ectomycorrhizal or endomycorrhizal fungi, and could also facilitate controlled mycorrhization in nursery practices where Acacia species are grown for forestation purposes.

  6. Efficiency of Conditionally Attenuated Salmonella enterica Serovar Typhimurium in Bacterium-Mediated Tumor Therapy

    Science.gov (United States)

    Frahm, Michael; Kocijancic, Dino; Rohde, Manfred; Hensel, Michael; Curtiss, Roy; Erhardt, Marc; Weiss, Siegfried

    2015-01-01

    ABSTRACT Increasing numbers of cancer cases generate a great urge for new treatment options. Applying bacteria like Salmonella enterica serovar Typhimurium for cancer therapy represents an intensively explored option. These bacteria have been shown not only to colonize solid tumors but also to exhibit an intrinsic antitumor effect. In addition, they could serve as tumor-targeting vectors for therapeutic molecules. However, the pathogenic S. Typhimurium strains used for tumor therapy need to be attenuated for safe application. Here, lipopolysaccharide (LPS) deletion mutants (ΔrfaL, ΔrfaG, ΔrfaH, ΔrfaD, ΔrfaP, and ΔmsbB mutants) of Salmonella were investigated for efficiency in tumor therapy. Of such variants, the ΔrfaD and ΔrfaG deep rough mutants exhibited the best tumor specificity and lowest pathogenicity. However, the intrinsic antitumor effect was found to be weak. To overcome this limitation, conditional attenuation was tested by complementing the mutants with an inducible arabinose promoter. The chromosomal integration of the respective LPS biosynthesis genes into the araBAD locus exhibited the best balance of attenuation and therapeutic benefit. Thus, the present study establishes a basis for the development of an applicably cancer therapeutic bacterium. PMID:25873375

  7. Streptococcus danieliae sp. nov., a novel bacterium isolated from the caecum of a mouse.

    Science.gov (United States)

    Clavel, Thomas; Charrier, Cédric; Haller, Dirk

    2013-01-01

    We report the characterization of one novel bacterium, strain ERD01G(T), isolated from the cecum of a TNF(deltaARE) mouse. The strain was found to belong to the genus Streptococcus based on phylogenetic analysis of partial 16S rRNA gene sequences. The bacterial species with standing name in nomenclature that was most closely related to our isolate was Streptococcus alactolyticus (97 %). The two bacteria were characterized by a DNA-DNA hybridization similarity value of 35 %, demonstrating that they belong to different species. The new isolate was negative for acetoin production, esculin hydrolysis, urease, α-galactosidase and β-glucosidase, was able to produce acid from starch and trehalose, grew as beta-hemolytic coccobacilli on blood agar, did not grow at >40 °C, did not survive heat treatment at 60 °C for 20 min and showed negative agglutination in Lancefield tests. On the basis of these characteristics, strain ERD01G(T) differed from the most closely related species S. alactolyticus, Streptococcus gordonii, Streptococcus intermedius and Streptococcus sanguinis. Thus, based on genotypic and phenotypic evidence, we propose that the isolate belongs to a novel bacterial taxon within the genus Streptococcus, for which the name Streptococcus danieliae is proposed. The type strain is ERD01G(T) (= DSM 22233(T) = CCUG 57647(T)).

  8. Bacillus subtilis: from soil bacterium to super-secreting cell factory

    Directory of Open Access Journals (Sweden)

    van Dijl Jan Maarten

    2013-01-01

    Full Text Available Abstract The biotechnology industry has become a key element in modern societies. Within this industry, the production of recombinant enzymes and biopharmaceutical proteins is of major importance. The global markets for such recombinant proteins are growing rapidly and, accordingly, there is a continuous need for new production platforms that can deliver protein products in greater yields, with higher quality and at lower costs. This calls for the development of next-generation super-secreting cell factories. One of the microbial cell factories that can meet these challenges is the Gram-positive bacterium Bacillus subtilis, an inhabitant of the upper layers of the soil that has the capacity to secrete proteins in the gram per litre range. The engineering of B. subtilis into a next-generation super-secreting cell factory requires combined Systems and Synthetic Biology approaches. In this way, the bacterial protein secretion machinery can be optimized from the single molecule to the network level while, at the same time, taking into account the balanced use of cellular resources. Although highly ambitious, this is an achievable objective due to recent advances in functional genomics and Systems- and Synthetic Biological analyses of B. subtilis cells.

  9. Biohydrogen Production by the Thermophilic Bacterium Caldicellulosiruptor saccharolyticus: Current Status and Perspectives

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    Servé W. M. Kengen

    2013-01-01

    Full Text Available Caldicellulosiruptor saccharolyticus is one of the most thermophilic cellulolytic organisms known to date. This Gram-positive anaerobic bacterium ferments a broad spectrum of mono-, di- and polysaccharides to mainly acetate, CO2 and hydrogen. With hydrogen yields approaching the theoretical limit for dark fermentation of 4 mol hydrogen per mol hexose, this organism has proven itself to be an excellent candidate for biological hydrogen production. This review provides an overview of the research on C. saccharolyticus with respect to the hydrolytic capability, sugar metabolism, hydrogen formation, mechanisms involved in hydrogen inhibition, and the regulation of the redox and carbon metabolism. Analysis of currently available fermentation data reveal decreased hydrogen yields under non-ideal cultivation conditions, which are mainly associated with the accumulation of hydrogen in the liquid phase. Thermodynamic considerations concerning the reactions involved in hydrogen formation are discussed with respect to the dissolved hydrogen concentration. Novel cultivation data demonstrate the sensitivity of C. saccharolyticus to increased hydrogen levels regarding substrate load and nitrogen limitation. In addition, special attention is given to the rhamnose metabolism, which represents an unusual type of redox balancing. Finally, several approaches are suggested to improve biohydrogen production by C. saccharolyticus.

  10. Genomic analysis reveals versatile heterotrophic capacity of a potentially symbiotic sulfur-oxidizing bacterium in sponge

    KAUST Repository

    Tian, Renmao

    2014-08-29

    Sulfur-reducing bacteria (SRB) and sulfur-oxidizing bacteria (SOB) play essential roles in marine sponges. However, the detailed characteristics and physiology of the bacteria are largely unknown. Here, we present and analyse the first genome of sponge-associated SOB using a recently developed metagenomic binning strategy. The loss of transposase and virulence-associated genes and the maintenance of the ancient polyphosphate glucokinase gene suggested a stabilized SOB genome that might have coevolved with the ancient host during establishment of their association. Exclusive distribution in sponge, bacterial detoxification for the host (sulfide oxidation) and the enrichment for symbiotic characteristics (genes-encoding ankyrin) in the SOB genome supported the bacterial role as an intercellular symbiont. Despite possessing complete autotrophic sulfur oxidation pathways, the bacterium developed a much more versatile capacity for carbohydrate uptake and metabolism, in comparison with its closest relatives (Thioalkalivibrio) and to other representative autotrophs from the same order (Chromatiales). The ability to perform both autotrophic and heterotrophic metabolism likely results from the unstable supply of reduced sulfur in the sponge and is considered critical for the sponge-SOB consortium. Our study provides insights into SOB of sponge-specific clade with thioautotrophic and versatile heterotrophic metabolism relevant to its roles in the micro-environment of the sponge body. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  11. Antibiotic stress selects against cooperation in the pathogenic bacterium Pseudomonas aeruginosa

    Science.gov (United States)

    Vasse, Marie; Noble, Robert J.; Akhmetzhanov, Andrei R.; Torres-Barceló, Clara; Gurney, James; Benateau, Simon; Gougat-Barbera, Claire; Kaltz, Oliver; Hochberg, Michael E.

    2017-01-01

    Cheats are a pervasive threat to public goods production in natural and human communities, as they benefit from the commons without contributing to it. Although ecological antagonisms such as predation, parasitism, competition, and abiotic environmental stress play key roles in shaping population biology, it is unknown how such stresses generally affect the ability of cheats to undermine cooperation. We used theory and experiments to address this question in the pathogenic bacterium, Pseudomonas aeruginosa. Although public goods producers were selected against in all populations, our competition experiments showed that antibiotics significantly increased the advantage of nonproducers. Moreover, the dominance of nonproducers in mixed cultures was associated with higher resistance to antibiotics than in either monoculture. Mathematical modeling indicates that accentuated costs to producer phenotypes underlie the observed patterns. Mathematical analysis further shows how these patterns should generalize to other taxa with public goods behaviors. Our findings suggest that explaining the maintenance of cooperative public goods behaviors in certain natural systems will be more challenging than previously thought. Our results also have specific implications for the control of pathogenic bacteria using antibiotics and for understanding natural bacterial ecosystems, where subinhibitory concentrations of antimicrobials frequently occur. PMID:28049833

  12. Discovery of putative small non-coding RNAs from the obligate intracellular bacterium Wolbachia pipientis.

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    Megan Woolfit

    Full Text Available Wolbachia pipientis is an endosymbiotic bacterium that induces a wide range of effects in its insect hosts, including manipulation of reproduction and protection against pathogens. Little is known of the molecular mechanisms underlying the insect-Wolbachia interaction, though it is likely to be mediated via the secretion of proteins or other factors. There is an increasing amount of evidence that bacteria regulate many cellular processes, including secretion of virulence factors, using small non-coding RNAs (sRNAs, but sRNAs have not previously been described from Wolbachia. We have used two independent approaches, one based on comparative genomics and the other using RNA-Seq data generated for gene expression studies, to identify candidate sRNAs in Wolbachia. We experimentally characterized the expression of one of these candidates in four Wolbachia strains, and showed that it is differentially regulated in different host tissues and sexes. Given the roles played by sRNAs in other host-associated bacteria, the conservation of the candidate sRNAs between different Wolbachia strains, and the sex- and tissue-specific differential regulation we have identified, we hypothesise that sRNAs may play a significant role in the biology of Wolbachia, and in particular in its interactions with its host.

  13. Host-extract induced changes in the secretome of the plant pathogenic bacterium Pectobacterium atrosepticum.

    Science.gov (United States)

    Mattinen, Laura; Nissinen, Riitta; Riipi, Tero; Kalkkinen, Nisse; Pirhonen, Minna

    2007-10-01

    Pectobacterium atrosepticum is a Gram-negative plant pathogenic bacterium that causes rotting in potato stems and tubers. The secreted proteins of this pathogen were analyzed with proteomics from culture supernatant of cells grown in minimal medium supplemented with host extracts. More than 40 proteins were identified, among them known virulence determinants, such as pectic enzymes, metalloprotease, and virulence protein Svx, along with flagella proteins, GroEL and cyclophilin-type chaperones and several hypothetical proteins or proteins with unknown function. Some of the identified proteins may be involved in utilization of nutrients or transport of minerals. Northern and real-time RT-PCR analyses suggested that most of the proteins upregulated by plant extract were transcriptionally regulated. Among the identified proteins were VgrG and four homologs of hemolysin-coregulated proteins (Hcps). A mutant strain lacking one of the hcp genes was not affected in virulence, while a bacterial strain overexpressing the same gene was shown to have increased virulence, which suggests that these proteins may be new virulence determinants of P. atrosepticum. Comparison of the secretomes of wild type cells and hrcC mutant defective in Type III secretion suggested that the production of the identified proteins was independent of functional Type III secretion system.

  14. Thorsellia anophelis is the dominant bacterium in a Kenyan population of adult Anopheles gambiae mosquitoes.

    Science.gov (United States)

    Briones, Aurelio M; Shililu, Josephat; Githure, John; Novak, Robert; Raskin, Lutgarde

    2008-01-01

    Anopheles gambiae mosquitoes are not known to harbor endosymbiotic bacteria. Here we show, using nucleic acid-based methods, that 16S rRNA gene sequences specific to a recently described mosquito midgut bacterium, Thorsellia anophelis, is predominant in the midgut of adult An. gambiae s.l. mosquitoes captured in residences in central Kenya, and also occurs in the aquatic rice paddy environment nearby. PCR consistently detected T. anophelis in the surface microlayer of rice paddies, which is also consistent with the surface-feeding behavior of A. gambiae s.l. larvae. Phylogenetic analysis of cloned environmental 16S rRNA genes identified four major Thorsellia lineages, which are closely affiliated to an insect endosymbiont of the genus Arsenophonus. Physiological characterizations support the hypothesis that T. anophelis is well adapted to the female anopheline midgut by utilizing blood and tolerating the alkaline conditions in this environment. The results suggest that aquatically derived bacteria such as T. anophelis can persist through mosquito metamorphosis and become well-established in the adult mosquito midgut.

  15. Global Microarray Analysis of Alkaliphilic Halotolerant Bacterium Bacillus sp. N16-5 Salt Stress Adaptation.

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    Liang Yin

    Full Text Available The alkaliphilic halotolerant bacterium Bacillus sp. N16-5 is often exposed to salt stress in its natural habitats. In this study, we used one-colour microarrays to investigate adaptive responses of Bacillus sp. N16-5 transcriptome to long-term growth at different salinity levels (0%, 2%, 8%, and 15% NaCl and to a sudden salt increase from 0% to 8% NaCl. The common strategies used by bacteria to survive and grow at high salt conditions, such as K+ uptake, Na+ efflux, and the accumulation of organic compatible solutes (glycine betaine and ectoine, were observed in Bacillus sp. N16-5. The genes of SigB regulon involved in general stress responses and chaperone-encoding genes were also induced by high salt concentration. Moreover, the genes regulating swarming ability and the composition of the cytoplasmic membrane and cell wall were also differentially expressed. The genes involved in iron uptake were down-regulated, whereas the iron homeostasis regulator Fur was up-regulated, suggesting that Fur may play a role in the salt adaption of Bacillus sp. N16-5. In summary, we present a comprehensive gene expression profiling of alkaliphilic Bacillus sp. N16-5 cells exposed to high salt stress, which would help elucidate the mechanisms underlying alkaliphilic Bacillus spp. survival in and adaptation to salt stress.

  16. Bioremediation of polluted beaches with PAHs by using biosurfactant produced by bacterium isolated from Persian Gulf

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    Sahand Jorfi

    2016-07-01

    Full Text Available Background: PAHs was producted from incomplete combustion of fossil fuels and due to nature of publishing, it was categorized as the soil and beaches pollutant. These compounds are considered in pollutants which have priority, carcinogenic and certain mutagenic. The main difficulty of clearing contaminated areas to PAHs is the nature of highly water repellent of these pollutants and a strong attraction to the soil texture. The main objective of this current study was to determine the efficiency of phenanthrene removal from contaminated soil and beaches by using biosurfactant produced by a bacterium isolated from Persian Gulf. Materials & Methods: with primary screening, a Bacillus sp strain with surfactin production capability was isolated and purified in laboratory. A mixed bacterial consortium isolated which was consists of three bacterial species with of capable of metabolism of phenanthrene from Khark contaminated beaches and was used as a microbial seed. The synthetic soil samples with initial phenanthrene concentration of 100 mg/kg and also natural contaminated samples were subjected to bioremediation during 9 weeks. Results: The phenanthrene removal efficiency in the samples containing biosurfactants and with artificial and natural pollution were 82% and 39% respectively. The removal efficiency for samples without biosurfactant was 11%. Conclusion: The bioremediation process is considered an efficient, eco-friendly and operational for remediation of beache and soil polluted by petroleum hydrocarbons by using bacterial biosurfactant.

  17. Enhancement of the Antibacterial Activity of Silver Nanoparticles against Phytopathogenic Bacterium Ralstonia solanacearum by Stabilization

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    Juanni Chen

    2016-01-01

    Full Text Available In this paper, the enhanced antibacterial activity of silver nanoparticles (AgNPs against the phytopathogenic bacterium Ralstonia solanacearum after stabilization using selected surfactants (SDS, SDBS, TX-100, and Tween 80 was examined, in comparison with silver ion. Tween 80 was found to be the most preferable stabilizer of AgNPs due to the beneficial synergistic effects of the AgNPs and surfactant. However, all the surfactants nearly had no effects on the antibacterial activity of Ag+. In vitro, Tween 80-stabilized AgNPs showed the highest bactericidal activity against R. solanacearum. Further measurements using TEM, fluorescence microscopy, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE revealed that though Ag+ and Tween 80-Ag+ induced high toxicity, Tween 80-stabilized AgNPs displayed most severe damage when in direct contact with cells, causing mechanistic injury to the cell membrane and strongly modifying and destructing the cellular proteins. Meanwhile, in vivo, the pot experiments data indicated that the control efficiency of Tween 80-stabilized AgNPs on tobacco bacterial wilt was 96.71%, 90.11%, and 84.21%, at 7 days, 14 days, and 21 days, respectively. Based on the results evidencing their advantageous low dosage requirements and strong antimicrobial activity, Tween 80-stabilized AgNPs are a promising antibacterial agent for use in alternative crop disease control approaches.

  18. A vaccine and diagnostic target for Clostridium bolteae, an autism-associated bacterium.

    Science.gov (United States)

    Pequegnat, Brittany; Sagermann, Martin; Valliani, Moez; Toh, Michael; Chow, Herbert; Allen-Vercoe, Emma; Monteiro, Mario A

    2013-06-10

    Constipation and diarrhea are common in autistic patients. Treatment with antibiotics against bacteria appears to partially alleviate autistic-related symptoms. Clostridium bolteae is a bacterium that has been shown to be overabundant in the intestinal tract of autistic children suffering from gastric intestinal ailments, and as such is an organism that could potentially aggravate gastrointestinal symptoms. We set out to investigate the cell-wall polysaccharides of C. bolteae in order to evaluate their structure and immunogenicity. Our explorations revealed that C. bolteae produces a conserved specific capsular polysaccharide comprised of rhamnose and mannose units: [→3)-α-D-Manp-(1→4)-β-d-Rhap-(1→], which is immunogenic in rabbits. These findings are the first description of a C. bolteae immunogen and indicate the prospect of using this polysaccharide as a vaccine to reduce or prevent C. bolteae colonization of the intestinal tract in autistic patients, and as a diagnostic marker for the rapid detection of C. bolteae in a clinical setting.

  19. The complete genome sequence of the plant growth-promoting bacterium Pseudomonas sp. UW4.

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    Jin Duan

    Full Text Available The plant growth-promoting bacterium (PGPB Pseudomonas sp. UW4, previously isolated from the rhizosphere of common reeds growing on the campus of the University of Waterloo, promotes plant growth in the presence of different environmental stresses, such as flooding, high concentrations of salt, cold, heavy metals, drought and phytopathogens. In this work, the genome sequence of UW4 was obtained by pyrosequencing and the gaps between the contigs were closed by directed PCR. The P. sp. UW4 genome contains a single circular chromosome that is 6,183,388 bp with a 60.05% G+C content. The bacterial genome contains 5,423 predicted protein-coding sequences that occupy 87.2% of the genome. Nineteen genomic islands (GIs were predicted and thirty one complete putative insertion sequences were identified. Genes potentially involved in plant growth promotion such as indole-3-acetic acid (IAA biosynthesis, trehalose production, siderophore production, acetoin synthesis, and phosphate solubilization were determined. Moreover, genes that contribute to the environmental fitness of UW4 were also observed including genes responsible for heavy metal resistance such as nickel, copper, cadmium, zinc, molybdate, cobalt, arsenate, and chromate. Whole-genome comparison with other completely sequenced Pseudomonas strains and phylogeny of four concatenated "housekeeping" genes (16S rRNA, gyrB, rpoB and rpoD of 128 Pseudomonas strains revealed that UW4 belongs to the fluorescens group, jessenii subgroup.

  20. The Lipid A from the Haloalkaliphilic Bacterium Salinivibrio sharmensis Strain BAGT

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    Maria Michela Corsaro

    2013-01-01

    Full Text Available Lipid A is a major constituent of the lipopolysaccharides (or endotoxins, which are complex amphiphilic macromolecules anchored in the outer membrane of Gram-negative bacteria. The glycolipid lipid A is known to possess the minimal chemical structure for LPSs endotoxic activity, able to cause septic shock. Lipid A isolated from extremophiles is interesting, since very few cases of pathogenic bacteria have been found among these microorganisms. In some cases their lipid A has shown to have an antagonist activity, i.e., it is able to interact with the immune system of the host without triggering a proinflammatory response by blocking binding of substances that could elicit such a response. However, the relationship between the structure and the activity of these molecules is far from being completely clear. A deeper knowledge of the lipid A chemical structure can help the understanding of these mechanisms. In this manuscript, we present our work on the complete structural characterization of the lipid A obtained from the lipopolysaccharides (LPS of the haloalkaliphilic bacterium Salinivibrio sharmensis. Lipid A was obtained from the purified LPS by mild acid hydrolysis. The lipid A, which contains different number of fatty acids residues, and its partially deacylated derivatives were completely characterized by means of electrospray ionization Fourier transform ion cyclotron (ESI FT-ICR mass spectrometry and chemical analysis.

  1. A novel radio-tolerant astaxanthin-producing bacterium reveals a new astaxanthin derivative: astaxanthin dirhamnoside.

    Science.gov (United States)

    Asker, Dalal; Awad, Tarek S; Beppu, Teruhiko; Ueda, Kenji

    2012-01-01

    Astaxanthin is a red ketocarotenoid that exhibits extraordinary health-promoting activities such as antioxidant, anti-inflammatory, antitumor, and immune booster. The recent discovery of the beneficial roles of astaxanthin against many degenerative diseases such as cancers, heart diseases, and exercise-induced fatigue has raised its market demand as a nutraceutical and medicinal ingredient in aquaculture, food, and pharmaceutical industries. To satisfy the growing demand for this high-value nutraceuticals ingredient and consumer interest in natural products, many research efforts are being made to discover novel microbial producers with effective biotechnological production of astaxanthin. Using a rapid screening method based on 16S rRNA gene, and effective HPLC-Diodearray-MS methods for carotenoids analysis, we succeeded to isolate a unique astaxanthin-producing bacterium (strain TDMA-17(T)) that belongs to the family Sphingomonadaceae (Asker et al., Appl Microbiol Biotechnol 77: 383-392, 2007). In this chapter, we provide a detailed description of effective HPLC-Diodearray-MS methods for rapid analysis and identification of the carotenoids produced by strain TDMA-17(T). We also describe the methods of isolation and identification for a novel bacterial carotenoid (astaxanthin derivative), a major carotenoid that is produced by strain TDMA-17(T). Finally, we describe the polyphasic taxonomic analysis of strain TDMA-17(T) and the description of a novel species belonging to genus Sphingomonas.

  2. Lysinibacillus tabacifolii sp. nov., a novel endophytic bacterium isolated from Nicotiana tabacum leaves.

    Science.gov (United States)

    Duan, Yan-Qing; He, Song-Tao; Li, Qing-Qing; Wang, Ming-Feng; Wang, Wen-Yuan; Zhe, Wei; Cao, Yong-Hong; Mo, Ming-He; Zhai, Yu-Long; Li, Wen-Jun

    2013-06-01

    A Gram-positive, catalase- and oxidase-positive, strictly aerobic, endospore-forming rod bacterium, designated K3514(T), was isolated from the leaves of Nicotiana tabacum. The strain was able to grow at temperatures of 8-40°C, pH 5.0-10.0 and NaCl concentrations of 0-7%. The predominant quinones (>30%) of this strain were MK-7(H2) and MK-7. Phylogenetic analysis of 16S rRNA gene sequence showed that strain K3514(T) was affiliated to the genus Lysinibacillus, with its closest relatives being Lysinibacillus mangiferihumi (98.3% sequence similarity), Lysinibacillus sphaericus (97.9% sequence similarity), Lysinibacillus fusiformis (97.4% sequence similarity), and Lysinibacillus xylanilyticus (97.3% sequence similarity). However, low levels of DNA-DNA relatedness values suggested that the isolate was distinct from the other closest Lysinibacillus species. Additionally, based on analysis of morphological, physiological, and biochemical characteristics, the isolate could be differentiated from the closest known relatives. Therefore, based on polyphasic taxonomic data, the novel isolate likely represents a novel species, for which the name Lysinibacillus tabacifolii sp. nov. and the type strain K3514(T) (=KCTC 33042(T) =CCTCC AB 2012050(T)) are proposed.

  3. Genomic analysis reveals versatile heterotrophic capacity of a potentially symbiotic sulfur-oxidizing bacterium in sponge.

    Science.gov (United States)

    Tian, Ren-Mao; Wang, Yong; Bougouffa, Salim; Gao, Zhao-Ming; Cai, Lin; Bajic, Vladimir; Qian, Pei-Yuan

    2014-11-01

    Sulfur-reducing bacteria (SRB) and sulfur-oxidizing bacteria (SOB) play essential roles in marine sponges. However, the detailed characteristics and physiology of the bacteria are largely unknown. Here, we present and analyse the first genome of sponge-associated SOB using a recently developed metagenomic binning strategy. The loss of transposase and virulence-associated genes and the maintenance of the ancient polyphosphate glucokinase gene suggested a stabilized SOB genome that might have coevolved with the ancient host during establishment of their association. Exclusive distribution in sponge, bacterial detoxification for the host (sulfide oxidation) and the enrichment for symbiotic characteristics (genes-encoding ankyrin) in the SOB genome supported the bacterial role as an intercellular symbiont. Despite possessing complete autotrophic sulfur oxidation pathways, the bacterium developed a much more versatile capacity for carbohydrate uptake and metabolism, in comparison with its closest relatives (Thioalkalivibrio) and to other representative autotrophs from the same order (Chromatiales). The ability to perform both autotrophic and heterotrophic metabolism likely results from the unstable supply of reduced sulfur in the sponge and is considered critical for the sponge-SOB consortium. Our study provides insights into SOB of sponge-specific clade with thioautotrophic and versatile heterotrophic metabolism relevant to its roles in the micro-environment of the sponge body.

  4. Toxicity of herbicides used in the sugarcane crop to diazotrophic bacterium Herbaspirillum seropedicae

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    Sergio de Oliveira Procópio

    2014-10-01

    Full Text Available The objective of this work was to identify herbicides used in the sugarcane crop that affects neither the growth, the development, of nor the process of biological nitrogen fixation (BNF by the diazotrophic bacterium Herbaspirillum seropedicae. Eighteen herbicides (paraquat, ametryne, tebuthiuron, amicarbazone, diuron, metribuzin, [hexazinone + diuron], [hexazinone + clomazone], clomazone, isoxaflutole, sulfentrazone, oxyfluorfen, imazapic, imazapyr, [trifloxysulfuron sodium + ametryne], glyphosate, MSMA e 2,4-D were tested in their respective commercial doses regarding their impact on the growth of the bacteria in liquid medium DIGs. For this, we determined the duration of lag phase, generation time and maximum cell density of H. seropedicae, calculated from optical density data obtained at regular intervals during the incubation of cultures for 33 h at 32oC. We also evaluated the impact of herbicides on nitrogenase activity of H. seropedicae grown in semi-solid N-free JNFb medium. The effects of herbicides on the growth variables and the ARA were compared with the untreated control by Dunnett test. A completely randomized design was used. The herbicides paraquat, imazapyr, ametryne, glyphosate and oxyfluorfen inhibited the growth of H. seropedicae in vitro. Ametryne, oxyfluorfen and glyphosate caused a small reduction in the duration of the lag phase of diazotrophic bacteria H. seropedicae. Oxyfluorfen, ametryne and imazapyr resulted in increased the generation time by H. seropedicae. Glyphosate promoted drastic reduction in biological nitrogen fixation in vitro by H. seropedicae. The other tested herbicides did not affect the growth or the same BNF by H. seropedicae.

  5. Landscape changes influence the occurrence of the melioidosis bacterium Burkholderia pseudomallei in soil in northern Australia.

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    Mirjam Kaestli

    Full Text Available BACKGROUND: The soil-dwelling saprophyte bacterium Burkholderia pseudomallei is the cause of melioidosis, a severe disease of humans and animals in southeast Asia and northern Australia. Despite the detection of B. pseudomallei in various soil and water samples from endemic areas, the environmental habitat of B. pseudomallei remains unclear. METHODOLOGY/PRINCIPAL FINDINGS: We performed a large survey in the Darwin area in tropical Australia and screened 809 soil samples for the presence of these bacteria. B. pseudomallei were detected by using a recently developed and validated protocol involving soil DNA extraction and real-time PCR targeting the B. pseudomallei-specific Type III Secretion System TTS1 gene cluster. Statistical analyses such as multivariable cluster logistic regression and principal component analysis were performed to assess the association of B. pseudomallei with environmental factors. The combination of factors describing the habitat of B. pseudomallei differed between undisturbed sites and environmentally manipulated areas. At undisturbed sites, the occurrence of B. pseudomallei was found to be significantly associated with areas rich in grasses, whereas at environmentally disturbed sites, B. pseudomallei was associated with the presence of livestock animals, lower soil pH and different combinations of soil texture and colour. CONCLUSIONS/SIGNIFICANCE: This study contributes to the elucidation of environmental factors influencing the occurrence of B. pseudomallei and raises concerns that B. pseudomallei may spread due to changes in land use.

  6. Roles of Thioredoxins in the Obligate Anaerobic Green Sulfur Photosynthetic Bacterium Chlorobaculum tepidum

    Institute of Scientific and Technical Information of China (English)

    Naomi Hosoya-Matsuda; Kazuhito Inoue; Toru Hisabori

    2009-01-01

    Thioredoxin is a small ubiquitous protein that is involved in the dithiol-disulfide exchange reaction, by way of two cysteine residues located on the molecule surface. In order to elucidate the role of thioredoxin in Chlorobaculum tepidum, an anaerobic green sulfur bacterium that uses various inorganic sulfur compounds and H2S as electron donors under strict anaerobic conditions for growth, we applied the thioredoxin affinity chromatography method (Motohashi et al., 2001). In this study, 37 cytoplasmic proteins were captured as thioredoxin target candidates, including proteins involved in sulfur assimilation. Furthermore, six of the candidate proteins were members of the reductive tricarboxylic acid cycle (pyruvate orthophosphate dikinase, pyruvate flavodoxin/ferredoxin oxidoreductase, α-oxoglutarate synthase, citrate lyase, citrate synthase, malate dehydrogenase). The redox sensitivity of three enzymes was then examined: citrate lyase, citrate synthase, and malate dehydrogenase, using their recombinant proteins. Based on the information relating to the target proteins, the significance of thioredoxin as a reductant for the metabolic pathway in the anaerobic photosyn-thetic bacteria is discussed.

  7. A Polysaccharide-Degrading Marine Bacterium Flammeovirga sp.MY04 and Its Extracellular Agarase System

    Institute of Scientific and Technical Information of China (English)

    HAN Wenjun; GU Jingyan; YAN Qiujie; LI Jungang; WU Zhihong; GU Qianqun; LI Yuezhong

    2012-01-01

    Bacteria of the genus Flammeovirga can digest complex polysaccharides(CPs),but no details have been reported regarding the CP depolymerases of these bacteria.MY04,an agarolytic marine bacterium isolated from coastal sediments,has been identified as a new member of the genus Flammeovirga.The MY04 strain is able to utilize multiple CPs as a sole carbon source and grows well on agarose,mannan,or xylan.This strain produces high concentrations of extracellular proteins (490mgL-1± 18.2 mgL-1liquid culture)that exhibit efficient and extensive degradation activities on various polysaccharides,especially agarose.These proteins have an activity of 310 U mg-1± 9.6 Umg-1 proteins.The extracellular agarase system(EAS)in the crude extracellular enzymes contains at least four agarose depolymerases,which are with molecular masses of approximately 30-70 kDa.The EAS is stable at a wide range of pH values(6.0-11.0),temperatures(0-50℃),and sodium chloride(NaCl)concentrations(0-0.9mol L-1).Two major degradation products generated from agarose by the EAS are identified to be neoagarotetraose and neoagarohexaose,suggesting that β-agarases are the major constituents of the MY04 EAS.These results suggest that the Flammeovirga strain MY04 and its polysaccharide-degradation system hold great promise in industrial applications.

  8. Applicability of recombinant β-xylosidase from the extremely thermophilic bacterium Geobacillus thermodenitrificans in synthesizing alkylxylosides.

    Science.gov (United States)

    Jain, Ira; Kumar, Vikash; Satyanarayana, T

    2014-10-01

    The β-xylosidase encoding gene (XsidB) of the extremely thermophilic bacterium Geobacillus thermodenitrificans has been cloned and expressed in Escherichia coli. The homotrimeric recombinant XsidB is of 204.0kDa, which is optimally active at 60°C and pH 7.0 with T1/2 of 58min at 70°C. The β-xylosidase remains unaffected in the presence of most metal ions and organic solvents. The Km [p-nitrophenyl β-xyloside (pNPX)], Vmax and kcat values of the enzyme are 2×10(-3)M, 1250μmolesmg(-1)min(-1) and 13.20×10(5)min(-1), respectively. The enzyme catalyzes transxylosylation reactions in the presence of alcohols as acceptors. The pharmaceutically important β-methyl-d-xylosides could be produced using pNPX as the donor and methanol as acceptor. The products of transxylosylation were identified by TLC and HPLC, and the structure was confirmed by (1)H NMR analysis. The enzyme is also useful in synthesizing transxylosylation products from the wheat bran hydrolysate.

  9. Oceanotoga teriensis gen. nov., sp. nov., a thermophilic bacterium isolated from offshore oil-producing wells.

    Science.gov (United States)

    Jayasinghearachchi, Himali S; Lal, Banwari

    2011-03-01

    A novel, moderately thermophilic, chemo-organotrophic bacterium was isolated from formation fluid samples from an offshore oil-production well head at Bombay High (Western India). Cells were rod-shaped with a sheath-like outer structure ('toga'); the cells appeared singly, in pairs or in short chains. Cells grew at 25-70 °C (optimum 55-58 °C), pH 5.5-9.0 (optimum pH 7.3-7.8) and 0-12  % (w/v) NaCl (optimum 4.0-4.5  %). The isolate was able to grow on various carbohydrates or complex proteinaceous substances. The isolate reduced thiosulfate and elemental sulfur. The major end products of glucose fermentation were acetate, H₂ and CO₂. The DNA G+C content of the genomic DNA was 26.8 mol%. Phylogenetic analysis of the 16S rRNA gene placed the strain within the order Thermotogales in the bacterial domain. On the basis of 16S rRNA gene sequence comparisons and in combination with morphological and physiological characteristics, the isolate represents a novel species of new genus, for which the name Oceanotoga teriensis gen. nov., sp. nov. is proposed. The type strain of the type species is OCT74(T) (=JCM 15580(T)=LMG 24865(T)).

  10. Regulation of iron transport related genes by boron in the marine bacterium Marinobacter algicola DG893.

    Science.gov (United States)

    Romano, Ariel; Trimble, Lyndsay; Hobusch, Ashtian R; Schroeder, Kristine J; Amin, Shady A; Hartnett, Andrej D; Barker, Ryan A; Crumbliss, Alvin L; Carrano, Carl J

    2013-08-01

    While there has been extensive interest in the use of boron isotope ratios as a surrogate of pH in paleoclimate studies in the context of climate change-related questions, the high (0.4 mM) concentration and the depth-independent (conservative or non-nutrient-like) concentration profile of this element have led to boron being neglected as a potentially biologically relevant element in the modern ocean. Here we report that boron affects the expression of a number of protein and genes in the "algal-associated" Gram-negative marine bacterium Marinobacter algicola DG893. Most intriguingly, a number of these proteins and genes are related to iron uptake. In a recent separate publication we have shown that boron regulates one such iron transport related protein, i.e. the periplasmic iron binding protein FbpA via a direct interaction of the metalloid with this protein. Here we show that a number of other iron uptake related genes are also affected by boron but in the opposite way i.e. they are up-regulated. We propose that the differential effect of boron on FbpA expression relative to other iron transport related genes is a result of an interaction between boron and the global iron regulatory protein Fur.

  11. What drives the occurrence of the melioidosis bacterium Burkholderia pseudomallei in domestic gardens?

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    Mirjam Kaestli

    2015-03-01

    Full Text Available Melioidosis is an often fatal infectious disease affecting humans and animals in tropical regions and is caused by the saprophytic environmental bacterium Burkholderia pseudomallei. Domestic gardens are not only a common source of exposure to soil and thus to B. pseudomallei, but they also have been found to contain more B. pseudomallei than other environments. In this study we addressed whether anthropogenic manipulations common to gardens such as irrigation or fertilizers change the occurrence of B. pseudomallei. We conducted a soil microcosm experiment with a range of fertilizers and soil types as well as a longitudinal interventional study over three years on an experimental fertilized field site in an area naturally positive for B. pseudomallei. Irrigation was the only consistent treatment to increase B. pseudomallei occurrence over time. The effects of fertilizers upon these bacteria depended on soil texture, physicochemical soil properties and biotic factors. Nitrates and urea increased B. pseudomallei load in sand while phosphates had a positive effect in clay. The high buffering and cation exchange capacities of organic material found in a commercial potting mix led to a marked increase in soil salinity with no survival of B. pseudomallei after four weeks in the potting mix sampled. Imported grasses were also associated with B. pseudomallei occurrence in a multivariate model. With increasing population density in endemic areas these findings inform the identification of areas in the anthropogenic environment with increased risk of exposure to B. pseudomallei.

  12. What drives the occurrence of the melioidosis bacterium Burkholderia pseudomallei in domestic gardens?

    Science.gov (United States)

    Kaestli, Mirjam; Harrington, Glenda; Mayo, Mark; Chatfield, Mark D; Harrington, Ian; Hill, Audrey; Munksgaard, Niels; Gibb, Karen; Currie, Bart J

    2015-03-01

    Melioidosis is an often fatal infectious disease affecting humans and animals in tropical regions and is caused by the saprophytic environmental bacterium Burkholderia pseudomallei. Domestic gardens are not only a common source of exposure to soil and thus to B. pseudomallei, but they also have been found to contain more B. pseudomallei than other environments. In this study we addressed whether anthropogenic manipulations common to gardens such as irrigation or fertilizers change the occurrence of B. pseudomallei. We conducted a soil microcosm experiment with a range of fertilizers and soil types as well as a longitudinal interventional study over three years on an experimental fertilized field site in an area naturally positive for B. pseudomallei. Irrigation was the only consistent treatment to increase B. pseudomallei occurrence over time. The effects of fertilizers upon these bacteria depended on soil texture, physicochemical soil properties and biotic factors. Nitrates and urea increased B. pseudomallei load in sand while phosphates had a positive effect in clay. The high buffering and cation exchange capacities of organic material found in a commercial potting mix led to a marked increase in soil salinity with no survival of B. pseudomallei after four weeks in the potting mix sampled. Imported grasses were also associated with B. pseudomallei occurrence in a multivariate model. With increasing population density in endemic areas these findings inform the identification of areas in the anthropogenic environment with increased risk of exposure to B. pseudomallei.

  13. A pseudokinase couples signaling pathways to enable asymmetric cell division in a bacterium

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    W. Seth Childers

    2014-12-01

    Full Text Available Bacteria face complex decisions when initiating developmental events such as sporulation, nodulation, virulence, and asymmetric cell division. These developmental decisions require global changes in genomic readout, and bacteria typically employ intricate (yet poorly understood signaling networks that enable changes in cell function. The bacterium Caulobacter crescentus divides asymmetrically to yield two functionally distinct cells: a motile, chemotactic swarmer cell, and a sessile stalked cell with replication and division capabilities. Work from several Caulobacter labs has revealed that differentiation requires concerted regulation by several two-component system (TCS signaling pathways that are differentially positioned at the poles of the predivisional cell (Figure 1. The strict unidirectional flow from histidine kinase (HK to the response regulator (RR, observed in most studied TCS, is difficult to reconcile with the notion that information can be transmitted between two or more TCS signaling pathways. In this study, we uncovered a mechanism by which daughter cell fate, which is specified by the DivJ-DivK-PleC system and effectively encoded in the phosphorylation state of the single-domain RR DivK, is communicated to the CckA-ChpT-CtrA signaling pathway that regulates more than 100 genes for polar differentiation, replication initiation and cell division. Using structural biology and biochemical findings we proposed a mechanistic basis for TCS pathway coupling in which the DivL pseudokinase is repurposed as a sensor rather than participant in phosphotransduction.

  14. Isolation and Characterization of a Novel Electrogenic Bacterium, Dietzia sp. RNV-4

    Science.gov (United States)

    Sacco, Natalia J.; Bonetto, M. Celina; Cortón, Eduardo

    2017-01-01

    Electrogenic bacteria are organisms that can transfer electrons to extracellular electron acceptors and have the potential to be used in devices such as bioelectrochemical systems (BES). In this study, Dietzia sp. RNV-4 bacterium has been isolated and identified based on its biochemical, physiological and morphological characteristics, as well as by its 16S rRNA sequence analysis. Furthermore, the current density production and electron transfer mechanisms were investigated using bioelectrochemical methods. The chronoamperometric data showed that the biofilm of Dietzia sp. RNV-4 grew as the current increased with time, reaching a maximum of 176.6 ± 66.1 mA/m2 at the end of the experiment (7 d); this highly suggests that the current was generated by the biofilm. The main electron transfer mechanism, indicated by the cyclic voltammograms, was due to secreted redox mediators. By high performance liquid chromatography, canthaxanthin was identified as the main compound involved in charge transfer between the bacteria and the solid electrodes. Dietzia sp. RNV-4 was used as biological material in a microbial fuel cell (MFC) and the current density production was 299.4 ± 40.2 mA/m2. This is the first time that Dietzia sp. RNV-4 has been electrochemically characterized and identified as a new electrogenic strain. PMID:28192491

  15. Roseomonas musae sp. nov., a new bacterium isolated from a banana phyllosphere.

    Science.gov (United States)

    Nutaratat, Pumin; Srisuk, Nantana; Duangmal, Kannika; Yurimoto, Hiroya; Sakai, Yasuyoshi; Muramatsu, Yuki; Nakagawa, Yasuyoshi

    2013-03-01

    A Gram-negative, coccobacilli, non-spore forming and non-motile bacterium, designated PN1(T), was isolated from a banana leaf collected in Mattra island, Thailand. This isolate was observed to grow optimally at 30 °C and pH 7.0, and to grow with 0-3 % NaCl. Comparative 16S rRNA gene sequence analysis showed that strain PN1(T) is closely related to members of the genus Roseomonas, exhibiting the highest 16S rRNA gene sequence similarity to Roseomonas aestuarii JC17(T) (96.5 %). The DNA G + C content of strain PN1(T) was determined to be 69.7 mol %. Based on physiological and biochemical tests, and genotypic differences between strain PN1(T) and the validly named species of the genus Roseomonas, it is proposed that the strain be classified as a new species of Roseomonas for which the name Roseomonas musae sp. nov. is proposed. The type strain is PN1(T) (= BCC 44863(T) = NBRC 107870(T)).

  16. 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.

  17. Identification of salt-inducible peptide with putative kinase activity in halophilic bacterium Virgibacillus halodenitrificans.

    Science.gov (United States)

    Rafiee, Mahmoud-Reza; Sokhansanj, Ashrafaddin; Yoosefi, Mitra; Naghizadeh, Mohammad-Ali

    2007-09-01

    Strain XII, a moderately halophilic bacterium, expressed a peptide in response to saline media. This peptide was designated as salt-inducible factor (Sif-A). The purpose of this study is to describe Sif-A, which might be involved in the osmoresistance mechanism of strain XII. The complete sequence of sif-A was determined using PCR. sif-A codes for a polypeptide of 20.518 kDa. The polypeptide has a putative signal peptide of 27 amino acids (2.667 kDa) preceding the mature protein (17.869 kDa). Motif analysis of the deduced amino acid sequence indicated that there is a p-loop NTPase domain on the C-terminal of the peptide, which might correlate with its function. The sequence of the 16S rRNA gene was analyzed phylogenetically to classify strain XII. This organism was found to have the closest association with Virgibacillus halodenitrificans, which was proven by its phenotypic characteristics.

  18. Purification and Characterization of Catalase from Marine Bacterium Acinetobacter sp. YS0810

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    Xinhua Fu

    2014-01-01

    Full Text Available The catalase from marine bacterium Acinetobacter sp. YS0810 (YS0810CAT was purified and characterized. Consecutive steps were used to achieve the purified enzyme as follows: ethanol precipitation, DEAE Sepharose ion exchange, Superdex 200 gel filtration, and Resource Q ion exchange. The active enzyme consisted of four identical subunits of 57.256 kDa. It showed a Soret peak at 405 nm, indicating the presence of iron protoporphyrin IX. The catalase was not apparently reduced by sodium dithionite but was inhibited by 3-amino-1,2,4-triazole, hydroxylamine hydrochloride, and sodium azide. Peroxidase-like activity was not found with the substrate o-phenylenediamine. So the catalase was determined to be a monofunctional catalase. N-terminal amino acid of the catalase analysis gave the sequence SQDPKKCPVTHLTTE, which showed high degree of homology with those of known catalases from bacteria. The analysis of amino acid sequence of the purified catalase by matrix-assisted laser desorption ionization time-of-flight mass spectrometry showed that it was a new catalase, in spite of its high homology with those of known catalases from other bacteria. The catalase showed high alkali stability and thermostability.

  19. Flow cytometric evaluation of the intracellular bacterium, Wolbachia pipientis, in mosquito cells

    Science.gov (United States)

    Fallon, Ann M

    2014-01-01

    Wolbachia is an obligate intracellular bacterium (Anaplasmataceae, Rickettisales) that occurs in arthropods and filarial worms, and spreads by vertical transmission in the oocyte cytoplasm. In insects, reproductive distortions associated with Wolbachia, such as cytoplasmic incompatibility in mosquitoes, have potential value for controlling pests, including species that transmit human, animal and plant diseases. Wolbachia strains that propagate as a persistent infection in insect cell lines provide an important resource for developing the genetic tools that will facilitate these applications. Here I describe conditions for flow cytometric evaluation of Wolbachia growth in persistently infected mosquito cells. Cytometry parameters were established using uninfected mosquito cells and Escherichia coli as a surrogate for Wolbachia, and quantitation was correlated with cell counts determined with a Coulter electronic cell counter and bacterial counts based on optical density. The protocol was validated by showing depletion of Wolbachia in medium containing tetracycline and rifampicin, and sensitivity of Wolbachia to treatment of host cells with paraquat, an oxidizing agent, and lumiflavin, an inhibitor of riboflavin uptake. The Wolbachia peak on the flow cytometry histogram was shown to contain Wolbachia by DNA analysis using the polymerase chain reaction, and by infection of naive recipient cells. This approach will streamline investigation of Wolbachia growth in insect cell lines and facilitate identification of culture conditions that select for Wolbachia-infected cells. PMID:25300665

  20. Iron and carbon metabolism by a mineral-oxidizing Alicyclobacillus-like bacterium.

    Science.gov (United States)

    Yahya, Adibah; Hallberg, Kevin B; Johnson, D Barrie

    2008-04-01

    A novel iron-oxidizing, moderately thermophilic, acidophilic bacterium (strain "GSM") was isolated from mineral spoil taken from a gold mine in Montana. Biomolecular analysis showed that it was most closely related to Alicyclobacillus tolerans, although the two bacteria differed in some key respects, including the absence (in strain GSM) of varpi-alicyclic fatty acids and in their chromosomal base compositions. Isolate GSM was able to grow in oxygen-free media using ferric iron as terminal electron acceptor confirming that it was a facultative anaerobe, a trait not previously described in Alicyclobacillus spp.. The acidophile used both organic and inorganic sources of energy and carbon, although growth and iron oxidation by isolate GSM was uncoupled in media that contained both fructose and ferrous iron. Fructose utilization suppressed iron oxidation, and oxidation of ferrous iron occurred only when fructose was depleted. In contrast, fructose catabolism was suppressed when bacteria were harvested while actively oxidizing iron, suggesting that both ferrous iron- and fructose-oxidation are inducible in this acidophile. Isolate GSM accelerated the oxidative dissolution of pyrite in liquid media either free of, or amended with, organic carbon, although redox potentials were significantly different in these media. The potential of this isolate for commercial mineral processing is discussed.