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Sample records for bacteria degrade explosives

  1. Bacteria and lignin degradation

    Institute of Scientific and Technical Information of China (English)

    Jing LI; Hongli YUAN; Jinshui YANG

    2009-01-01

    Lignin is both the most abundant aromatic (phenolic) polymer and the second most abundant raw material.It is degraded and modified by bacteria in the natural world,and bacteria seem to play a leading role in decomposing lignin in aquatic ecosystems.Lignin-degrading bacteria approach the polymer by mechanisms such as tunneling,erosion,and cavitation.With the advantages of immense environmental adaptability and biochemical versatility,bacteria deserve to be studied for their ligninolytic potential.

  2. Chitin Degradation In Marine Bacteria

    DEFF Research Database (Denmark)

    Paulsen, Sara; Machado, Henrique; Gram, Lone

    2015-01-01

    Introduction: Chitin is the most abundant polymer in the marine environment and the second most abundant in nature. Chitin does not accumulate on the ocean floor, because of microbial breakdown. Chitin degrading bacteria could have potential in the utilization of chitin as a renewable carbon and...... nitrogen source in the fermentation industry.Methods: Here, whole genome sequenced marine bacteria were screened for chitin degradation using phenotypic and in silico analyses.Results: The in silico analyses revealed the presence of three to nine chitinases in each strain, however the number of chitinases...... chitin regulatory system.Conclusions: This study has provided insight into the ecology of chitin degradation in marine bacteria. It also served as a basis for choosing a more efficient chitin degrading production strain e.g. for the use of chitin waste for large-scale fermentations....

  3. Degradation of monomethylhydrazine by two soil bacteria

    International Nuclear Information System (INIS)

    It has been reported that three heterotrophic soil bacteria had the capacity to degrade hydrazine. One of these organisms, Achromobacter sp., degraded hydrazine to N2 gas. Furthermore, it was reported that monomethylhydrazine (MMH) in Arredondo fine sand was mineralized to CO2, and that such degradation is microbial. However, microorganisms that degrade MMH have not been reported. MMH and hydrazine are chemically similar to one another. Therefore, this study was initiated to test the capacity of the two hydrazine-degrading bacteria, Achromobacter sp. and Pseudomonas sp., to degrade MMH

  4. HYDROCARBON-DEGRADING BACTERIA AND SURFACTANT ACTIVITY

    Energy Technology Data Exchange (ETDEWEB)

    Brigmon, R; Topher Berry, T; Grazyna A. Plaza, G; jacek Wypych, j

    2006-08-15

    Fate of benzene ethylbenzene toluene xylenes (BTEX) compounds through biodegradation was investigated using two different bacteria, Ralstonia picketti (BP-20) and Alcaligenes piechaudii (CZOR L-1B). These bacteria were isolated from extremely polluted petroleum hydrocarbon contaminated soils. PCR and Fatty Acid Methyl Ester (FAME) were used to identify the isolates. Biodegradation was measured using each organism individually and in combination. Both bacteria were shown to degrade each of the BTEX compounds. Alcaligenes piechaudii biodegraded BTEXs more efficiently while mixed with BP-20 and individually. Biosurfactant production was observed by culture techniques. In addition 3-hydroxy fatty acids, important in biosurfactant production, was observed by FAME analysis. In the all experiments toluene and m+p- xylenes were better growth substrates for both bacteria than the other BTEX compounds. In addition, the test results indicate that the bacteria could contribute to bioremediation of aromatic hydrocarbons (BTEX) pollution increase biodegradation through the action by biosurfactants.

  5. Degradation of multiwall carbon nanotubes by bacteria

    International Nuclear Information System (INIS)

    Understanding the environmental transformation of multiwall carbon nanotubes (MWCNTs) is important to their life cycle assessment and potential environmental impacts. We report that a bacterial community is capable of degrading 14C-labeled MWCNTs into 14CO2 in the presence of an external carbon source via co-metabolism. Multiple intermediate products were detected, and genotypic characterization revealed three possible microbial degraders: Burkholderia kururiensis, Delftia acidovorans, and Stenotrophomonas maltophilia. This result suggests that microbe/MWCNTs interaction may impact the long-term fate of MWCNTs. Highlights: •Mineralization of MWCNTs by a bacterial community was observed. •The mineralization required an external carbon source. •Multiple intermediate products were identified in the MWCNT degrading culture. •Three bacterial species were found likely responsible for MWCNT degradation. -- The 14C-labeled multiwall carbon nanotubes can be degraded to 14CO2 and other byproducts by a bacteria community under natural conditions

  6. Halide salts accelerate degradation of high explosives by zerovalent iron

    International Nuclear Information System (INIS)

    Zerovalent iron (Fe0, ZVI) has drawn great interest as an inexpensive and effective material to promote the degradation of environmental contaminants. A focus of ZVI research is to increase degradation kinetics and overcome passivation for long-term remediation. Halide ions promote corrosion, which can increase and sustain ZVI reactivity. Adding chloride or bromide salts with Fe0 (1% w/v) greatly enhanced TNT, RDX, and HMX degradation rates in aqueous solution. Adding Cl or Br salts after 24 h also restored ZVI reactivity, resulting in complete degradation within 8 h. These observations may be attributed to removal of the passivating oxide layer and pitting corrosion of the iron. While the relative increase in degradation rate by Cl- and Br- was similar, TNT degraded faster than RDX and HMX. HMX was most difficult to remove using ZVI alone but ZVI remained effective after five HMX reseeding cycles when Br- was present in solution. - The addition of halide ions promotes the degradation of high explosives by zerovalent iron

  7. Interspecific interactions of heterotrophic bacteria during chitin degradation

    OpenAIRE

    Jagmann, Nina

    2012-01-01

    In their natural habitats, bacteria live in multi-species microbial communities and are, thus, constantly interacting with bacteria of other phylogenetic groups. In order to prevail in these interspecific interactions, such as the competition for nutrients, bacteria have developed numerous strategies. During the degradation of polymers such interspecific interactions are likely to occur, because degradation starts as an extracellular process. In one possible interaction scenario, investor bac...

  8. Nitrogen acquisition in Agave tequilana from degradation of endophytic bacteria.

    Science.gov (United States)

    Beltran-Garcia, Miguel J; White, James F; Prado, Fernanda M; Prieto, Katia R; Yamaguchi, Lydia F; Torres, Monica S; Kato, Massuo J; Medeiros, Marisa H G; Di Mascio, Paolo

    2014-01-01

    Plants form symbiotic associations with endophytic bacteria within tissues of leaves, stems, and roots. It is unclear whether or how plants obtain nitrogen from these endophytic bacteria. Here we present evidence showing nitrogen flow from endophytic bacteria to plants in a process that appears to involve oxidative degradation of bacteria. In our experiments we employed Agave tequilana and its seed-transmitted endophyte Bacillus tequilensis to elucidate organic nitrogen transfer from (15)N-labeled bacteria to plants. Bacillus tequilensis cells grown in a minimal medium with (15)NH4Cl as the nitrogen source were watered onto plants growing in sand. We traced incorporation of (15)N into tryptophan, deoxynucleosides and pheophytin derived from chlorophyll a. Probes for hydrogen peroxide show its presence during degradation of bacteria in plant tissues, supporting involvement of reactive oxygen in the degradation process. In another experiment to assess nitrogen absorbed as a result of endophytic colonization of plants we demonstrated that endophytic bacteria potentially transfer more nitrogen to plants and stimulate greater biomass in plants than heat-killed bacteria that do not colonize plants but instead degrade in the soil. Findings presented here support the hypothesis that some plants under nutrient limitation may degrade and obtain nitrogen from endophytic microbes. PMID:25374146

  9. ISOLATION AND IDENTIFICATION OF ACR YLAMIDE DEGRADING BACTERIA FROM SOIL

    OpenAIRE

    Nidhi Jain; John, P. J.; Kanti Prakash Sharma; Soni, I.

    2013-01-01

    Acrylamide is an aliphatic amide, which is produced by industrial processes and during heating of food. It is neurotoxic and a suspected carcinogen. In the present study an attempt was made to isolate acrylamide degrading bacteria from soil. The optimum growth conditions and physiological characteristics for the isolated acrylamide degrading bacteria were investigated. The isolated bacterium was identified as Bacillus clausii strain 1779 based on full 16S rRNA molecular phylogeny. The bacteri...

  10. ISOLATION AND IDENTIFICATION OF ACR YLAMIDE DEGRADING BACTERIA FROM SOIL

    Directory of Open Access Journals (Sweden)

    Nidhi Jain

    2013-02-01

    Full Text Available Acrylamide is an aliphatic amide, which is produced by industrial processes and during heating of food. It is neurotoxic and a suspected carcinogen. In the present study an attempt was made to isolate acrylamide degrading bacteria from soil. The optimum growth conditions and physiological characteristics for the isolated acrylamide degrading bacteria were investigated. The isolated bacterium was identified as Bacillus clausii strain 1779 based on full 16S rRNA molecular phylogeny. The bacteria can degrade 800 mg l-1acrylamide after eight days of incubation with concomitant cell growth. In addition to above, it also grows optimally at a concentration of acrylamide between 500-2000 mg l-1between pH 8-10 and temperature and 25 – 45 0C. Thus the isolate would be useful in the bioremediation of environment from acrylamide in alkali conditions.

  11. Degradation of PAHs in soil by indigenous and inoculated bacteria

    International Nuclear Information System (INIS)

    In soil heavily polluted by coal tar, the inherent mineralization of radio-labeled phenanthrene to 14CO2 was relatively slow, and a stimulation of degradation was observed by inoculation with a mixed population of PAH-degrading bacteria. A much faster inherent mineralization of phenanthrene was observed in soil slightly polluted by coal tar, and inoculation of this soil had no effect. Several phenanthrene-degrading bacteria were isolated from different soils. Two strains were further characterized as an Arthrobacter sp. and a Pseudomonas sp. In an organic medium without phenanthrene, growth rates of 0.52 h-1 and 0.71 h-1 were measured for the Arthrobacter sp. and the Pseudomonas sp., respectively. Most isolates grown in the phenanthrene-free medium, including the Arthrobacter sp., rapidly adapted to phenanthrene degradation following transfer to a phenanthrene-containing medium. In contrast, the phenanthrene-degrading capability of other strains, including the Pseudomonas sp., was lost during growth in the phenanthrene-free medium. Growth in an organic medium without phenanthrene of strains that retain the ability to degrade phenanthrene could prove to be a useful technique for production of PAH-degrading bacteria on a larger scale for soil inoculation

  12. Degradation of polymer waterproofing by alpha particles and soil bacteria

    International Nuclear Information System (INIS)

    This was a preparatory study aimed at addressing two issues: (i) Ageing and degradation of normal types of polymeric waterproofing materials during long-time exposure to radon and soil bacteria and (ii) Temperature dependence (0 deg C to 40 deg C) of the radon diffusion coefficient for common non-degraded insulating materials. Shore D hardness was measured for unexposed and exposed high-density and low-density polyethylene. Module of elasticity, elongation, and tensile strength were also measured. (orig)

  13. Isolation and identification of Profenofos degrading bacteria

    Directory of Open Access Journals (Sweden)

    Saadatullah Malghani

    2009-12-01

    Full Text Available An enrichment culture technique was used to isolate bacterial strains responsible for the biodegradation of profenofos in a soil from Hubei province of central China. Two pure bacterial cultures, named W and Y, were isolated and subsequently characterized by sequencing of 16S rRNA genes and biochemical tests. Isolate W showed 96% similarity to the 16S rRNA gene of a Pseudomonas putida unlike Y which showed 99% similarity to the 16S rRNA gene of Burkholderia gladioli. Both strains grew well at pH 5.5-7.2 with a broad temperature profile ranging from 28º to 36 ºC. Bioremediation of profenofos-contaminated soil was examined using soil treated with 200 ug g-1; profenofos resulted in a higher degradation rate than control soils without inoculation. In a mineral salt medium (FTW reduction in profenofos concentration was 90% within 96 hours of incubation. A literature survey revealed that no data is available regarding the role of Burkholderia gladioli on pesticide biodegradation as well as on profenofos.

  14. Biotransformations of 2-methylisoborneol by camphor-degrading bacteria.

    Science.gov (United States)

    Many camphor-degrading bacteria that are able to transform 2-methylisoborneol (MIB) have been identified. Three strains representative of these, have been examined in detail. Rhodococcus ruber T1 metabolizes camphor through 6-hydroxycamphor, but converts MIB to 2,3-dihydroxy-2-methylbornane. Pseu...

  15. Endophytic degrader bacteria for improving phytoremediation of organic xenobiotics

    DEFF Research Database (Denmark)

    Karlson, U.; Trapp, Stefan; Lelie, D, van der;

    2003-01-01

    This project represented a completely new approach towards improving the technology of phytoremediation of soil and groundwater contaminated with water soluble and volatile compounds. It endeavoured to tackle the problem of inefficient degradation of these compounds during phytoremediation...... bacteria, and the isolation of a large number of natural endophytic strains. The project delivered on this goal by providing a large collection of 150 novel characterized endophytic bacteria from poplar and willow, two plant species commonly used for phytoremediation, and from Flag Iris, a plant used...... for the novel technology of constructed wetlands. Several of these bacteria were engineered to degrade specific organic contaminants, including BTEX, TCE, 2,4-D and naphthalene. Central to the whole project was the goal to reveal the potential of endophytic inoculants for improving phytoremediation in terms...

  16. Distribution and activity of petroleum hydrocarbon degrading bacteria in the North Sea and Baltic Sea

    International Nuclear Information System (INIS)

    Data were collected in 1988 and 1989 on the distribution and activity of petroleum hydrocarbon degrading bacteria in the North Sea and Baltic Sea. Crude oil degrading bacteria and the number of bacteria which in particular degrade naphthalene were quantified using a modified dilution method (MPN). Crude oil degrading bacteria were present in all of about 100 water samples, with as many as 103 ml-1 in some samples. Numbers of naphthalene degrading bacteria were at least tenfold lower. There is obviously a greater connection between this bacteria group and petroleum hydrocarbon (PHC) contamination than between the more nonspecific group of crude oil degrading bacteria and PHC contamination. Data from the North Sea show an extremely high abundance of hydrocarbon degrading bacteria, even in winter, while in the southern Baltic Sea low numbers of bacteria were found and slower crude oil degradation was observed. (orig.)

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

    Science.gov (United States)

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

    2012-11-01

    To obtain efficient halotolerant petroleum-degrading bacteria, 39 bacteria strains were isolated from 30 petroleum contaminated saline soil samples in Yellow River Delta, an important base of petroleum production in China. One bacterium (strain BM38) was found to efficiently degrade crude oil in highly saline environments based on a series of liquid and soil incubation experiments. According to its morphology, physiochemical characteristics and 16S rDNA sequence analysis, this strain was identified as Pseudomonas putida. Moreover, a series of liquid incubation experiments were conducted to investigate its characteristics such as halotolerance, biosurfactants production and degrading efficiency for various hydrocarbons. The salt resistance test demonstrated that strain BM38 grew well at NaCl concentrations ranging from 0.5% to 6.0%. Petroleum degradation experiments showed that strain BM38 could degrade 73.5% crude oil after 7 days in a liquid culture medium containing 1.0% NaCl and remove more than 40% of total petroleum hydrocarbons after 40 days in the soil with 0.22% and 0.61% of salinity, these results proved that the strain was effective in removing petroleum hydrocarbons. Strain BM38 could produce a bioemulsifier in a liquid culture medium. The NaCl concentration had the significant effect on the EI24 of fermentation broth, which decreased sharply if the NaCl concentration was greater than 1.0%. However, the EI24 of BM38 was still quite high in the presence of 2.0% of NaCl, and the value was 61.0%. Furthermore, this strain was also able to grow in mineral liquid media amended with hexadecane, toluene, phenanthrene, isooctane and cyclohexane as the sole carbon sources. Among these hydracarbons, strain BM38 showed relatively high ability in degrading n-alkanes and aromatic hydracarbons. The results indicated that strain BM38 had potential for application in bioremediation of petroleum-contaminated saline soil. PMID:23323430

  18. Isolation of imidacloprid degrading bacteria from industrial sites

    International Nuclear Information System (INIS)

    Immidacloprid is a cyclodiene organochlorine used as an insecticide all over the world and possessing a serous environmental threat. It is mostly used for cotton insects (bollworm, aphid and white fly). For isolation of imidacloprid degrading bacteria, two soil samples were collected from industrial contaminated sites of Kala Shah Kahu district sheikupura, having ten year history of use. Soil samples were analyzed by measuring pH and electric conductivity. The isolation of imidacroprid degrading bacteria was performed by enrichment technique. Eight bacterial strains, S/sub 1-a/ S/2-2-b/ S/2-c/ S/2-d/ S/2-e/ S/sub 2-f/ and S/sub 2-g/ and S/sub e-a/ were isolated on the basis of their colony morphologies. The purified colonies were characterized morphologically, physiologically and biochemically. Gram staining was done and Gram negative strain were confirmed on MacConkey agar and Eosin Methylene Blue. Bacterial strains were also checked for different minimal media in which only carbon source was the imidcloprid. For this purpose. FTW, FTW without N/sub 2/ NSM, M/sub 9/ and MM/sub 2/ media were used and their optical densities were taken on spectrophotometer isolates were checked for resistance to antibiotics and heavy metals. On these characteristics, S/sub 2-d/ and S/sub c-a/ were assigned to Enterobacteriaceae, S/sub 2-b/ to Pseudomonad and rest of the bacterial isolates were affiliated to bacillaceae. (author)

  19. Different Abilities of Eight Mixed Cultures of Methane-oxidizing Bacteria to Degrade TCE

    DEFF Research Database (Denmark)

    Broholm, Kim; Christensen, Thomas Højlund; Jensen, Bjørn K.

    1993-01-01

    The ability of eight mixed cultures of methane-oxidizing bacteria to degrade trichloroethylene (TCE) was examined in laboratory batch experiments. This is one of the first reported works studying TCE degradation by mixed cultures of methane-oxidizing bacteria at 10°C, a common temperature for soils...... degradation of methane and TCE. During the first 10–15 days after the addition of methane a significant degradation of methane and a minor degradation of TCE were observed. This experiment revealed that the ability of mixed cultures of methane-oxidizing bacteria to degrade TCE varied significantly even though...

  20. Enumeration and phylogenetic analysis of polycyclic aromatic hydrocarbon-degrading marine bacteria from Puget sound sediments.

    OpenAIRE

    Geiselbrecht, A D; Herwig, R P; Deming, J. W.; Staley, J T

    1996-01-01

    Naphthalene- and phenanthrene-degrading bacteria in Puget Sound sediments were enumerated by most-probable-number enumeration procedures. Sediments from a creosote-contaminated Environmental Protection Agency Superfund Site (Eagle Harbor) contained from 10(4) to 10(7) polycyclic aromatic hydrocarbon (PAH)-degrading bacteria g (dry weight) of sediment-1, whereas the concentration at an uncontaminated site ranged from 10(3) to 10(4) g of sediment(-1). Isolates of PAH-degrading bacteria were obt...

  1. Isolation of imidacloprid degrading bacteria from cotton fields

    International Nuclear Information System (INIS)

    Imidacloprid is cyclodiene organochlorine, used as an insecticide all over the world an possess a serious environmental threat. It is mostly used for cotton insects (bollworm, aphid and white fly). For isolation of imidacloprid degrading bacteria three soil samples were collected from cotton fields of district Layyah having five years history of use. Soil samples were analyzed by measuring pH and electric conductivity. The isolation of imidacroprid degrading bacteria was performed by enrichment technique. Fourteen bacterial strains: S/sub i-a/, S/sub i-b/, S/sub i-c/, S/sub i-d/, S/sub i-e/, S/sub a-a/, S/a-b/, S/a-c/, S/a-d/, S/sub b-a/, S/sub b-b/, S/sub b-c/, S/sub b-d/ and S/b-e/ were isolated on the basis of their colony morphologies. The purified colonies were characterized morphologically physiologically and biochemically. Gram staining was done and Gram staining was done and Gram negative strains were confirmed on macConkey agar and Eosin methylene blue. Bacterial strains were also checked for different minimal media in which only carbon source was the imidacloprid. For this purpose FTW, FTW without N/sun 2/, NSM, M/sub 9/ and MM/sub 2/ media were used and their optical densities were taken on spectrophotometer, isolates were checked for resistance to antibiotics and heavy metals. On the basis of these characteristics. S/sub a-c/ and S/sub l-d/ were assigned to Enterobacteriaceae, S/sub a-b/ to Pseudomonadaceae and rest of the bacterial isolates were affiliated. (author)

  2. Toxicity of tetracyclines and tetracycline degradation products to environmentally relevant bacteria, including selected tetracycline-resistant bacteria

    DEFF Research Database (Denmark)

    Halling-Sørensen, B.; Sengeløv, G.; Tjørnelund, J.

    2002-01-01

    Tetracyclines used in veterinary therapy invariably will find their way as parent compound and degradation products to the agricultural field. Major degradation products formed due to the limited stability of parent tetracyclines (tetracycline, chlortetracycline, and oxytetracycline) in aqueous...... same concentration level as tetracycline, chlortetracycline, and oxytetracycline on both the sludge and the tetracycline-sensitive soil bacteria. Further, both 5a,6-anhydrotetracychne and 5a,6-anhydrochlortetracycline had potency on tetracycline-resistant bacteria supporting a mode of action different...

  3. [Isolation, screening and identification of prometryne-degrading bacteria and their degrading characteristics].

    Science.gov (United States)

    Zhou, Ji-Hai; Sun, Xiang-Wu; Hu, Feng; Li, Hui-Xin

    2013-07-01

    The purpose of this study was to develop some bacterial strains that could degrade prometryne effectively. Bacteria were screened and purified from sediments of a pesticide plant with the method of domestication with gradient concentrations. Two strains were isolated and named P-1 and P-2, respectively. According to their morphology, physiological, biochemical properties and the analysis of their 16S rRNA gene sequences, the strain P-1 is Gram negative and identified as Ochrobactrum; the strain P-2 is Gram positive and identified as Bacillus. GenBank Accession numbers are HM004554 and HM004555, respectively. Degradation rates of the strains P-1 and P-2 for prometryne concentration with 40 mg x L(-1) were 46.5% and 65.4% after 12 days in the liquid culture experiment, respectively. This study provides an essential material and theoretical foundation for the remediation of prometryne contaminated soils. PMID:24028029

  4. Enhanced degradation of textile effluent in constructed wetland system using Typha domingensis and textile effluent-degrading endophytic bacteria.

    Science.gov (United States)

    Shehzadi, Maryam; Afzal, Muhammad; Khan, Muhammad Umar; Islam, Ejazul; Mobin, Amina; Anwar, Samina; Khan, Qaiser Mahmood

    2014-07-01

    Textile effluent is one of the main contributors of water pollution and it adversely affects fauna and flora. Constructed wetland is a promising approach to remediate the industrial effluent. The detoxification of industrial effluent in a constructed wetland system may be enhanced by applying beneficial bacteria that are able to degrade contaminants present in industrial effluent. The aim of this study was to evaluate the influence of inoculation of textile effluent-degrading endophytic bacteria on the detoxification of textile effluent in a vertical flow constructed wetland reactor. A wetland plant, Typha domingensis, was vegetated in reactor and inoculated with two endophytic bacterial strains, Microbacterium arborescens TYSI04 and Bacillus pumilus PIRI30. These strains possessed textile effluent-degrading and plant growth-promoting activities. Results indicated that bacterial inoculation improved plant growth, textile effluent degradation and mutagenicity reduction and were correlated with the population of textile effluent-degrading bacteria in the rhizosphere and endosphere of T. domingensis. Bacterial inoculation enhanced textile effluent-degrading bacterial population in rhizosphere, root and shoot of T. domingensis. Significant reductions in COD (79%), BOD (77%) TDS (59%) and TSS (27%) were observed by the combined use of plants and bacteria within 72 h. The resultant effluent meets the wastewater discharge standards of Pakistan and can be discharged into the environment without any risks. This study revealed that the combined use of plant and endophytic bacteria is one of the approaches to enhance textile effluent degradation in a constructed wetland system. PMID:24755300

  5. Genetic and immunochemical characterization of thiocyanate-degrading bacteria in lake water.

    Science.gov (United States)

    Yamasaki, Manabu; Matsushita, Yasuhiko; Namura, Motonobu; Nyunoya, Hiroshi; Katayama, Yoko

    2002-02-01

    Natural aquatic and soil samples were screened for the presence of thiocyanate-degrading bacteria. Using thiocyanate supplementation, we established an enrichment culture containing such bacteria from lake water. The dominant bacteria had the scnC-LS5 gene encoding thiocyanate hydrolase, which was closely related to the enzyme found previously in Thiobacillus thioparus THI115 isolated from activated sludge. PMID:11823241

  6. Genetic and Immunochemical Characterization of Thiocyanate-Degrading Bacteria in Lake Water

    OpenAIRE

    Yamasaki, Manabu; Matsushita, Yasuhiko; Namura, Motonobu; Nyunoya, Hiroshi; Katayama, Yoko

    2002-01-01

    Natural aquatic and soil samples were screened for the presence of thiocyanate-degrading bacteria. Using thiocyanate supplementation, we established an enrichment culture containing such bacteria from lake water. The dominant bacteria had the scnC-LS5 gene encoding thiocyanate hydrolase, which was closely related to the enzyme found previously in Thiobacillus thioparus THI115 isolated from activated sludge.

  7. Aromatic Hydrocarbons: Degrading Bacteria in the Desert Soil of Kuwait

    International Nuclear Information System (INIS)

    Soil samples of different levels of oil pollutants were collected from Kuwait's Burgan Oil Field, near an oil lake. The samples represented, highly polluted (8.0% w/w), moderately polluted (2.1%-3.4%) and slightly polluted (2.1%-3.4%) and slightly polluted (0.5- 0.8%). The aromatic fractions of the collected samples were in the range of (0.21-2.57g/100g) soil. (GC) analysis of the aromatic fractions of the resolution of the different individual (PAHs) revealed the presence of (16) different (PAHs) resolved from the aromatic fraction of the highly polluted sample (S3). (15), (14) and (13) individual (PAHs) were identified soil samples (S5), (S2) and (S1, S4, S6) respectively. The most frequent (PAH) was indeno (1, 2, 3-c, d) pyrene (22.5%-45.11%) followed chrysene (13.6%-19.48%). Eight carcinogenic (PAHs) were resolved from the aromatic fractions of the polluted samples. Total carcinogenic (PAHs) recorded in this study were in this study were in the range of (11.53) (forS4) - (510.98) (for S3) ppm. The counts of (CFU) of aromatic degraders (AD) were in the range of (3x10) - (110x 10) (CFU/g) soil (with a percent of (2.2%-69.6%)). The results show that, higher counts of (AD) were recorded from a highly polluted sample (S3), followed by the moderately polluted samples; total of (51) bacteria, that gave presumptive positive biodegradation activities, were isolated and identified (45.1%) of them were isolated and identified. (45.1%) of them were isolated from the highly polluted sample (S3). Total of (13) different species were identified of which Micrococcus luteus was more frequent (23.5) followed by Bacillus licheniformis (19.6%) and Bacillus subtilis (11.8%). The three Pseudomonas species collectively were presented by (11.8%). Five different species proved to be of good activities, they are: Bacillus brevis, Bacillus lichenoformis, Pseudomonas aeruginosa, Pseudomonas stutzeri and Pseudomonas flourescens. The ability of five species and their mixture was

  8. Selection of the Bacteria Being Able to Degrade Kerosene and Study on the Growth Conditions of the Bacteria

    Institute of Scientific and Technical Information of China (English)

    LI; Ping; ZHUO; Feng-ping; GAO; Li-hong; CAI; Ming

    2012-01-01

    [Objective] The study aimed at selecting the predominant strains being able to degrade kerosene and studying its best growth conditions. [Method] Choosing kerosene as the only carbon source, we selected and separated the predominant strains being able to degrade kerosene from the contaminated soil near petrochemical plants, and then optimized the grow conditions of the bacteria. [Result] The best conditions for the bacteria growth were determined as follows, that is, temperature was 30 ℃, pH=7, salinity was 2.5%, and the rotational speed of the thermostatic shake was 190 r/min. Under the optimal conditions, the degradation rate of kerosene by the bacteria cultured for three days reached 42.6%. [Conclusion] The research could provide scientific references for the restoration of polluted soil by kerosene.

  9. Different Abilities of Eight Mixed Cultures of Methane-oxidizing Bacteria to Degrade TCE

    DEFF Research Database (Denmark)

    Broholm, Kim; Christensen, Thomas Højlund; Jensen, Bjørn K.

    1993-01-01

    The ability of eight mixed cultures of methane-oxidizing bacteria to degrade trichloroethylene (TCE) was examined in laboratory batch experiments. This is one of the first reported works studying TCE degradation by mixed cultures of methane-oxidizing bacteria at 10°C, a common temperature for soils...... and groundwaters. Only three of the eight mixed cultures were able to degrade TCE, or to degrade TCE fast enough to result in a significant removal of TCE within the experimental time, when the cultures used methane as growth substrate. The same three mixed cultures were able to degrade TCE when they...... oxidized methanol, but only for a limited time period of about 5 days. Several explanations for the discontinued degradation of TCE are given. An experiment carried out to re-activate the methane-oxidizing bacteria after 8 days of growth on methanol by adding methane did not immediately result in...

  10. Degradation of Bermuda and Orchard Grass by Species of Ruminal Bacteria

    OpenAIRE

    Akin, Danny E.; Rigsby, Luanne L.

    1985-01-01

    Fiber degradation in Bermuda grass and orchard grass was evaluated gravimetrically and by scanning and transmission electron microscopy after incubation with pure cultures of rumen bacteria. Lachnospira multiparus D-32 was unable to degrade plant cell wall components. Butyrivibrio fibrisolvens 49 degraded 6 and 14.9% of the fiber components in Bermuda grass and orchard grass, respectively, and Ruminococcus albus 7 degraded 11.4% orchard grass fiber but none in Bermuda grass. Both B. fibrisolv...

  11. Distribution of Digoxin-reducing, Oxalate-degrading, and Total Anaerobic Bacteria in the Human Colon

    OpenAIRE

    Weaver, G A; Krause, J A; Allison, M J; Lindenbaum, J.

    2011-01-01

    Samples of the mucosal surface of the caecum and sigmoid colon were obtained from 33 colonoscopy subjects for microbiol studies using a microbiology brush system. Faecal samples and caecal lumen aspirates were also obtained. Estimated numbers of digoxin-reducing, oxalate-degrading and total anaerobic bacteria from the caecal brush samples correlated significantly with the respective concentrations of these organisms from the sigmoid area. The concentrations of oxalate-degrading bacteria and t...

  12. Anaerobic degradation of naphthalene by the mixed bacteria under nitrate reducing conditions

    International Nuclear Information System (INIS)

    Mixed bacteria were enriched from soil samples contaminated with polycyclic aromatic hydrocarbons (PAHs). The anaerobic degradation characteristics by the enriched bacteria with different initial naphthalene concentrations were investigated under nitrate reducing conditions. The results showed that the mixed bacteria could degrade nearly all the naphthalene over the incubations of 25 days when the initial naphthalene concentration was below 30 mg/L. The degradation rates of naphthalene increased with increasing initial concentrations. A high naphthalene concentration of 30 mg/L did not inhibit neither on the bacterial growth nor on the naphthalene degradation ability. The accumulation of nitrite was occurred during the reduction of nitrate, and a nitrite concentration of 50 mg/L had no inhibition effect on the degradation of naphthalene. The calculation of electron balances revealed that most of the naphthalene was oxidized whereas a small proportion was used for cell synthesis.

  13. Crude oil degradation by phosphate-solubilizing bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    DeSouza, M.J.B.D.; Nair, S.; David, J.J.; Chandramohan, D.

    adherence to undecane and hexadecane. The degradation of crude oil by these two isolates was 62% and 85%. Mixed cultures of the two isolates showed 91% degradation. It was evident from the gas chromatographic analysis that all fractions of crude oil were...

  14. Isolation and characterization of endosulfan-degrading bacteria from contaminated agriculture soils

    Institute of Scientific and Technical Information of China (English)

    Mehdi Hassanshahian; Zahra Shahi

    2016-01-01

    Objective: To isolate and characterize endosulfan-degrading bacteria from Kerman pistachio orchards. Methods: Endosulfan-degrading bacteria were enriched in Bushnell-Hass medium. Identification and sequencing of prevalent degrading strains was performed by usingPCR based on amplifying16S rDNA. Results: The results showed that the soils of pistachio orchards have some degrading bacteria that are suitable for elimination of endosulfan from soils and the environment. Four endosulfan-degrading bacteria strains belong toAchromobacter xylosoxidans (strain EN3),Pseudomonas azotoformans (strain EN4),Pseudomonas brassicacearum (strain EN7) andPseudomonas thivervalensis (strain EN8), respectively. The best degrading strain (EN7), up to 100 mg/L, illustrated a good growth, whereas the growth was reduced in concentration higher than 100 mg/L. The results of gas chromatography confirmed the decomposition of organic pesticide by degrading-bacteria. Conclusions: By using these strains and other biological reclamation methods we can eliminate bio-environmental problems.

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

    Science.gov (United States)

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

    2015-12-15

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

  16. Ecodynamics of oil-degrading bacteria and significance of marine mixed populations in the degradation of petroleum compounds

    International Nuclear Information System (INIS)

    Ecological studies, screening of hydrocarbon-degrading bacteria, and studies of the potentials of various single and mixed bacterial populations in the utilization of petroleum compounds were carried out to understand the microbial hydrocarbon degradation process in marine ecosystems. Populations of hydrocarbon utilizers were larger in coastal regions than in pelagic environments. Ecological observations indicated that oil-degrading bacteria were ubiquitously distributed in both temperate and tropical environments, irrespective of oil-polluted and unpolluted ecosystem. Bacteria were grown with n-tet-radecane, pristane, propylbenzene, phenanthrene, and crude oil as the sole carbon source; and substrate specificities of the purified strains were characterized. Based on the assimilation characteristics of the isolated strains, an artificial mixed-culture system was constructed. Biodegradation of crude oil by the natural mixed population was found to be higher than by the artificial mixed population. However, when some of the substrate-specific degraders were artificially mixed with natural microflora, the degradation of hard-to-degrade aromatic hydrocarbon fractions of crude oil was enhanced

  17. Degradation of norgestrel by bacteria from activated sludge: comparison to progesterone.

    Science.gov (United States)

    Liu, Shan; Ying, Guang-Guo; Liu, You-Sheng; Peng, Fu-Qiang; He, Liang-Ying

    2013-09-17

    Natural and synthetic progestagens in the environment have become a concern due to their adverse effects on aquatic organisms. Laboratory studies were performed to investigate aerobic biodegradation of norgestrel by bacteria from activated sludge in comparison with progesterone, and to identify their degradation products and biotransformation pathways. The degradation of norgestrel followed first order reaction kinetics (T1/2 = 12.5 d), while progesterone followed zero order reaction kinetics (T1/2 = 4.3 h). Four and eight degradation products were identified for norgestrel and progesterone, respectively. Six norgestrel-degrading bacterial strains (Enterobacter ludwigii, Aeromonas hydrophila subsp. dhakensis, Pseudomonas monteilii, Comamonas testosteroni, Exiguobacterium acetylicum, and Chryseobacterium indologenes) and one progesterone-degrading bacterial strain (Comamonas testosteroni) were successfully isolated from the enrichment culture inoculated with aerobic activated sludge. To our best knowledge, this is the first report on the biodegradation products and degrading bacteria for norgestrel under aerobic conditions. PMID:23952780

  18. Impact of Inoculation Protocols, Salinity, and pH on the Degradation of Polycyclic Aromatic Hydrocarbons (PAHs) and Survival of PAH-Degrading Bacteria Introduced into Soil

    OpenAIRE

    Kästner, Matthias; Breuer-Jammali, Maren; Mahro, Bernd

    1998-01-01

    Degradation of polycyclic aromatic hydrocarbons (PAHs) and survival of bacteria in soil was investigated by applying different inoculation protocols. The soil was inoculated with Sphingomonas paucimobilis BA 2 and strain BP 9, which are able to degrade anthracene and pyrene, respectively. CFU of soil bacteria and of the introduced bacteria were monitored in native and sterilized soil at different pHs. Introduction with mineral medium inhibited PAH degradation by the autochthonous microflora a...

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

    Institute of Scientific and Technical Information of China (English)

    LU Si-jin; WANG Hong-qi; YAO Zhi-hua

    2006-01-01

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

  20. Biotransformations of 2-methylisoborneol by Terpene-Degrading Bacteria

    Science.gov (United States)

    2-Methylisoborneol (MIB) is produced by a variety of bacteria including actinomycetes and cyanobacteria. When it is present, it gives a camphoraceous earthy off-flavor and smell to farm-raised catfish or drinking water. One way to solve the problem of MIB in catfish ponds or reservoirs might be to...

  1. Degradation of alkenones by aerobic heterotrophic bacteria: Selective or not ?

    Digital Repository Service at National Institute of Oceanography (India)

    Rontani, J-F.; Harji, R.; Guasco, S.; Prahl, F.G.; Volkman, J.K.; Bhosle, N.B.; Bonin, P.

    Géochimie et d’Ecologie Marines (UMR 6117), Centre d'Océanologie de Marseille, F-13288 Marseille, France b National Institute of Oceanography (CSIR), Dona Paula – 403 004, Goa, India c College of Oceanic and Atmospheric Sciences, Oregon State University... with antibiotics. 2. Experimental 2.1. Substrate preparation for degradation studies Emiliania huxleyi strain TWP1 obtained from the Caen (France) Algobank were used as substrate for alkenone degradation. A 100 ml starter culture was transferred to flasks...

  2. Identification of soil bacteria able to degrade phenanthrene bound to a hydrophobic sorbent in situ

    International Nuclear Information System (INIS)

    Efficient bioremediation of PAH-contaminated sites is limited by the hydrophobic character and poor bioavailability of pollutants. In this study, stable isotope probing (SIP) was implemented to track bacteria that can degrade PAHs adsorbed on hydrophobic sorbents. Temperate and tropical soils were incubated with 13C-labeled phenanthrene, supplied by spiking or coated onto membranes. Phenanthrene mineralization was faster in microcosms with PAH-coated membranes than in microcosms containing spiked soil. Upon incubation with temperate soil, phenanthrene degraders found in the biofilms that formed on coated membranes were mainly identified as Sphingomonadaceae and Actinobacteria. In the tropical soil, uncultured Rhodocyclaceae dominated degraders bound to membranes. Accordingly, ring-hydroxylating dioxygenase sequences recovered from this soil matched PAH-specific dioxygenase genes recently found in Rhodocyclaceae. Hence, our SIP approach allowed the detection of novel degraders, mostly uncultured, which differ from those detected after soil spiking, but might play a key role in the bioremediation of PAH-polluted soils. -- Highlights: •Soil bacteria with the ability to degrade sorbent-bound PAHs were investigated. •In soil, membrane-bound phenanthrene was readily mineralized. •PAH degraders found in biofilms were different in temperate and tropical soils. •Uncultured Rhodocyclaceae were dominant phenanthrene degraders in the tropical soil. •PAH-specific ring-hydroxylating dioxygenase sequences were identified in soil DNA. -- Bacteria able to degrade PAHs bound to a hydrophobic sorbent were mainly identified as uncultured Rhodocyclaceae and Sphingomonadaceae in polluted soils from tropical and temperate area, respectively

  3. Isolation and characterization of Fenitrothion-degrading bacteria from pestachio gardens in Kerman Provinance

    Directory of Open Access Journals (Sweden)

    Mehrnosh Ghafari

    2014-07-01

    Full Text Available   Introduction : Pesticides with complex structure have high persistence in ecosystem and biosphere. Pesticides have harmful effects on farmlands, human and natural resources.   Materials and methods: In this study for isolation of pesticide-degrading bacteria (Fenitrothion soil samples were collected from pistachio gardens in Kerman province. Collected soil samples were enriched in Bushnell Hass medium with this pesticide as only carbon and energy source. Isolated bacteria were identified by amplification of 16S rDNA gene by PCR and sequencing .   Results : In this study three Fenitrothion -degrading bacterial strains were isolated. These isolated bacteria were identified as: Pseudomonas fluorescens strain F1 ، Bacillus cereus strain F3 and pseudomonas aeruginosa strain F4 . The effects of pesticides concentration on each dominant bacterial strain were investigated. For Fenitrothion degrading bacterium (F4 strain growth continue until 100 ppm and then decreased. The result of Gas Chromatography (GC analysis confirmed the biodegradation ability of selected bacterial strains .   Discussion and conclusion : The results of this study demonstrated that there is a diversity of pesticide-degrading bacteria (Fenitrothion in soil ecosystem farmlands of Kerman province. It is seemed by application of these pesticide-degrading bacteria in farmlands and using bioremediation technique the ecosystem contamination of pesticide can be decreased.

  4. Identification of Wastewater Bacteria Involved in the Degradation of Triclocarban and its Non-Chlorinated Congener

    OpenAIRE

    Miller, Todd R.; Colquhoun, David R.; Halden, Rolf U.

    2010-01-01

    Triclocarban (TCC) is an antimicrobial additive of personal care products that is only partially degraded during wastewater treatment. Bacteria responsible for its transformation are unknown. We obtained wastewater bacteria capable of using as the sole carbon source TCC or its non-chlorinated analog, carbanilide (NCC). Enrichments established using activated sludge amended with TCC and NCC, respectively, were maintained for one year through successive transfers. Enrichments displayed exponent...

  5. The Evolution of bird plumage colouration: a role for feather-degradation bacteria?

    OpenAIRE

    Grande, Juan Manuel; Negro, Juan J.; Torres, María José

    2004-01-01

    [ENG] Aims: To test the existence of differences in the effects in vitro of a feather-degrading bacteria on bird feat- hers containing different types of pigments, and thus, of different colours. Methods: Tubes containing feathers from nine bird species and containing three different pigments or no pig- ments were inoculated with bacteria (Bacillus licheniformis isolated from soil) and incubated at 37°C during eight days. Feather damage was monitored daily. Results and Conclusi...

  6. Acetylene degradation by new isolates of aerobic bacteria and comparison of acetylene hydratase enzymes

    OpenAIRE

    Rosner, Bettina M; Rainey, Frederick A.; Kroppenstedt, Reiner M.; Schink, Bernhard

    1997-01-01

    Aerobic acetylene-degrading bacteria were isolated from soil samples. Two isolates were assigned to the species Rhodococcus opacus, two others to Rhodococcus ruber and Gordona sp. They were compared with known strains of aerobic acetylene-, cyanide-, or nitrile-utilizing bacteria. The acetylene hydratases of R. opacus could be measured in cell-free extracts only in the presence of a strong reductant like titanium(III) citrate. Expression of these enzymes was molybdenum-dependent. Acetylene hy...

  7. Isolation and characterization of Fenitrothion-degrading bacteria from pestachio gardens in Kerman Provinance

    OpenAIRE

    Mehrnosh Ghafari; Mehdi Hassanshahian; Mohammad Mahani

    2014-01-01

      Introduction : Pesticides with complex structure have high persistence in ecosystem and biosphere. Pesticides have harmful effects on farmlands, human and natural resources.   Materials and methods: In this study for isolation of pesticide-degrading bacteria (Fenitrothion) soil samples were collected from pistachio gardens in Kerman province. Collected soil samples were enriched in Bushnell Hass medium with this pesticide as only carbon and energy source. Isolated bacteria were identified b...

  8. Impairment of cellulose- and cellobiose-degrading soil Bacteria by two acidic herbicides.

    Science.gov (United States)

    Schellenberger, Stefanie; Drake, Harold L; Kolb, Steffen

    2012-02-01

    Herbicides have the potential to impair the metabolism of soil microorganisms. The current study addressed the toxic effect of bentazon and 4-chloro-2-methylphenoxyacetic acid on aerobic and anaerobic Bacteria that are involved in cellulose and cellobiose degradation in an agricultural soil. Aerobic saccharide degradation was reduced at concentrations of herbicides above environmental values. Microbial processes (e.g. fermentations, ferric iron reduction) that were linked to anaerobic cellulose and cellobiose degradation were reduced in the presence of both herbicides at concentrations above and at those that occur in crop field soil. 16S rRNA gene transcript numbers of total Bacteria, and selected bacterial taxa (Clostridia [Group I], Planctomycetaceae, and two uncultivated taxa of Bacteroidetes) decreased more in anoxic than in oxic cellulose-supplemented soil microcosms in the presence of both herbicides. Collectively, the results suggested that the metabolism of anaerobic cellulose-degrading Bacteria was impaired by typical in situ herbicide concentrations, whereas in situ concentrations did not impair metabolism of aerobic cellulose- and cellobiose-degrading soil Bacteria. PMID:22098368

  9. Aromatic compound degradation by iron reducing bacteria isolated from irrigated tropical paddy soils

    Institute of Scientific and Technical Information of China (English)

    LU Wenjing; WANG Hongtao; HUANG Changyong; W. Reichardt

    2008-01-01

    Forty-six candidate phenol/benzoate degrading-iron reducing bacteria were isolated from long term irrigated tropical paddy soils by enrichment procedures. Pure cultures and some prepared mixed cultures were examined for ferric oxide reduction and phenol/benzoate degradation. All the isolates were iron reducers, but only 56.5% could couple iron reduction to phenol and/or benzoate degradation, as evidenced by depletion of phenol and benzoate after one week incubation. Analysis of degradative capability using Biolog MT plates revealed that most of them could degrade other aromatic compounds such as ferulic acid, vanillic acid, and hydroxybenzoate. Mixed-cultures and soft samples displayed greater capacity for aromatic degradation and iron reduction than pure bacterial isolates, suggesting that these reactions may be coupled via a consortia-based mechanism in paddy soils.

  10. SIP metagenomics identifies uncultivated Methylophilaceae as dimethylsulphide degrading bacteria in soil and lake sediment

    OpenAIRE

    Eyice, Özge; Namura, Motonobu; Chen, Yin; Mead, Andrew; Samavedam, Siva; Schäfer, Hendrik

    2015-01-01

    Dimethylsulphide (DMS) has an important role in the global sulphur cycle and atmospheric chemistry. Microorganisms using DMS as sole carbon, sulphur or energy source, contribute to the cycling of DMS in a wide variety of ecosystems. The diversity of microbial populations degrading DMS in terrestrial environments is poorly understood. Based on cultivation studies, a wide range of bacteria isolated from terrestrial ecosystems were shown to be able to degrade DMS, yet it remains unknown whether ...

  11. Comparison of factors influencing trichloroethylene degradation by toluene-oxidizing bacteria.

    OpenAIRE

    Leahy, J G; Byrne, A M; Olsen, R H

    1996-01-01

    The degradation of trichloroethylene (TCE) by toluene-oxidizing bacteria has been extensively studied, and yet the influence of environmental conditions and physiological characteristics of individual strains has received little attention. To consider these effects, the levels of TCE degradation by strains distinguishable on the basis of toluene and nitrate metabolism were compared under aerobic or hypoxic conditions in the presence and absence of nitrate and an exogenous electron donor, lact...

  12. Phytate Degradation by Fungi and Bacteria that Inhabit Sawdust and Coffee Residue Composts

    OpenAIRE

    Eida, Mohamed Fathallh; Nagaoka, Toshinori; Wasaki, Jun; Kouno, Kenji

    2012-01-01

    Phytate is the primary source of organic phosphorus, but it cannot be directly utilized by plants and is strongly adsorbed by the soil, reducing bioavailability. Composting is a process used to improve the bioavailability of phytate in organic wastes through degradation by microorganisms. In this study, we aimed to investigate the phytate-degrading ability of fungi and bacteria that inhabit sawdust compost and coffee residue compost, and their contribution to the composting process. In the pl...

  13. Exploring the microbiota dynamics related to vegetable biomasses degradation and study of lignocellulose-degrading bacteria for industrial biotechnological application

    Science.gov (United States)

    Ventorino, Valeria; Aliberti, Alberto; Faraco, Vincenza; Robertiello, Alessandro; Giacobbe, Simona; Ercolini, Danilo; Amore, Antonella; Fagnano, Massimo; Pepe, Olimpia

    2015-02-01

    The aims of this study were to evaluate the microbial diversity of different lignocellulosic biomasses during degradation under natural conditions and to isolate, select, characterise new well-adapted bacterial strains to detect potentially improved enzyme-producing bacteria. The microbiota of biomass piles of Arundo donax, Eucalyptus camaldulensis and Populus nigra were evaluated by high-throughput sequencing. A highly complex bacterial community was found, composed of ubiquitous bacteria, with the highest representation by the Actinobacteria, Proteobacteria, Bacteroidetes and Firmicutes phyla. The abundances of the major and minor taxa retrieved during the process were determined by the selective pressure produced by the lignocellulosic plant species and degradation conditions. Moreover, cellulolytic bacteria were isolated using differential substrates and screened for cellulase, cellobiase, xylanase, pectinase and ligninase activities. Forty strains that showed multienzymatic activity were selected and identified. The highest endo-cellulase activity was seen in Promicromonospora sukumoe CE86 and Isoptericola variabilis CA84, which were able to degrade cellulose, cellobiose and xylan. Sixty-two percent of bacterial strains tested exhibited high extracellular endo-1,4-ß-glucanase activity in liquid media. These approaches show that the microbiota of lignocellulosic biomasses can be considered an important source of bacterial strains to upgrade the feasibility of lignocellulose conversion for the `greener' technology of second-generation biofuels.

  14. POTENCY OF LIGNOCELLULOSE DEGRADING BACTERIA ISOLATED FROM BUFFALO AND HORSE GASTROINTESTINAL TRACT AND ELEPHANT DUNG FOR FEED FIBER DEGRADATION

    Directory of Open Access Journals (Sweden)

    A. Wahyudi

    2014-10-01

    Full Text Available Lignin is limiting factor for cellulose and hemicellulose degradation in rumen. Isolation andselection bacteria from buffalo and horse gastrointestinal tract and elephant dung could be foundbacteria that have superiority to degrade lignin, xylan, and cellulose. Those animals were chosenbecause they were herbivores that consume low quality crude fiber as their main energy sources.Lignocellulose degrading bacteria were isolated by Hungate selective media, by using lignin (tannicacid, xylan, and cellulose as selective substrates. The morphological identification used an enrichmentmedia by measuring color, colony size, diffusion zone, clear zone, and biochemical identification usingproduction of ligninase, xylanase, and cellulase enzymes. The best lignocellulose degrading bacteriathen was determined by the morphological and biochemical character. This study showed thatlignocellulose degrading bacteria could be found in gastrointestinal tract of buffalo and horse, andelephant dung. Highest number colony was found in samples from buffalo's colon (376, followed byhorse's cecum (203, elephant’s dung (46, buffalo’s cecum (23, buffalo's rumen (9 and horse’s colon(7. The highest isolates activity of lignolytic, xylanolytic, and cellulolytic were reached by buffalo’scecum (7.64, horse's cecum (6.27, and buffalo’s colon (2.48. Meanwhile the highest enzymesproductivities were: buffalo’s cecum (0.0400 µmol, horse’s cecum (1.3912 µmol and buffalo’s colon(0.1971 µmol. Based on morphologycal character and biochemical test, it could be concluded thatlignolytic from buffalo’s cecum, xylanolytic from horse’s cecum, and cellulolytic from buffalo’s colonwere the superior isolates and they were 99% analyzed as Enterococcus casseliflavus/gallinarumspecies.

  15. Indigenous oil-degrading bacteria in crude oil-contaminated seawater of the Yellow sea, China.

    Science.gov (United States)

    Wang, Wanpeng; Zhang, Rongqiu; Zhong, Rongqiu; Shan, Dapeng; Shao, Zongze

    2014-08-01

    Indigenous oil-degrading bacteria play an important role in efficient remediation of polluted marine environments. In this study, we investigated the diversity and abundance of indigenous oil-degrading bacteria and functional genes in crude oil-contaminated seawater of the Dalian coast. The gene copy number bacterial 16S rRNA in total were determined to be about 10(10) copies L(-1) in contaminated seawater and 10(9) copies L(-1) in uncontaminated seawater. Bacteria of Alcanivorax, Marinobacter, Novosphingobium, Rhodococcus, and Pseudoalteromonas were found to be predominant oil-degrading bacteria in the polluted seawater in situ. In addition, bacteria belonging to Algoriphagus, Aestuariibacter, Celeribacter, Fabibacter, Zobellia, Tenacibaculum, Citreicella, Roseivirga, Winogradskyella, Thioclava, Polaribacter, and Pelagibaca were confirmed to be the first time as an oil-degrading bacterium. The indigenous functional enzymes, including AlkB or polycyclic aromatic hydrocarbons ring-hydroxylating dioxygenases α (PAH-RHDα) coding genes from Gram-positive (GP) and Gram-negative bacteria (GN), were revealed and quite diverse. About 10(10) to 10(11) copies L(-1) for the expression of alkB genes were recovered and showed that the two-thirds of all the AlkB sequences were closely related to widely distributed Alcanivorax and Marinobacter isolates. About 10(9) copies L(-1) seawater for the expression of RHDαGN genes in contaminated seawater and showed that almost all RHDαGN sequences were closely related to an uncultured bacterium; however, RHDαGP genes represented only about 10(5) copies L(-1) seawater for the expression of genes in contaminated seawater, and the naphthalene dioxygenase sequences from Rhodococcus and Mycobacterium species were most abundant. Together, their data provide evidence that there exists an active aerobic microbial community indigenous to the coastal area of the Yellow sea that is capable of degrading petroleum hydrocarbons. PMID:24866944

  16. Abundance and activity of oil-degrading and indigenous bacteria in sediment microcosms

    International Nuclear Information System (INIS)

    The responses of bacterial community composition and degradation crude oil to applications of bioremediation products and plant detrital material were investigated in wetlands microcosms. The microcosms were constructed of sieved sediments and operated as tidal marshes. Products included nutrients, organisms, surfactants and combinations thereof; dried ground Spartina was the source of detrital material. Plate count and most probable-number techniques were used to enumerate microbial populations and GC/MS analysis of indicator petroleum hydrocarbons was used to assess oil degradation. Microbial communities were characterized by whole-genome hybridization and specific probes for bacterial groups, including Pseudomonas, Streptomycetes, Vibrio, and sulfate-reducing bacteria. Although the total microbial numbers were similar in all bioremediation treatments, the numbers of oil degraders increased two to three log units in the fertilizer and microbial-degrader-enriched treatments. Oil-degraders comprised the largest fraction of the total population in the treatment amended with microbial degraders, apparently at the expense of indigenous bacteria, as indicated by specific probes. Oil-degraders were also detected in the subsurface in all treatments except the controls. The extent of oil degradation was not consistent with bacterial numbers; only nutrient additions resulted in significantly enhanced degradation of oil. After 1 month of microcosm operation, oil-degraders had increased at least two orders of magnitude in sediment surface layers when oil was added alone or with Spartina detritus, although total bacterial numbers and the number of oil-degraders decreased to near initial levels by 2 months. The peak coincides with bacterial utilization of the alkane fraction of petroleum hydrocarbons

  17. 2,4-Dichlorophenoxyacetic acid-degrading bacteria contain mosaics of catabolic genes.

    OpenAIRE

    Fulthorpe, R R; McGowan, C; Maltseva, O V; Holben, W E; Tiedje, J M

    1995-01-01

    DNA from 32 2,4-dichlorophenoxyacetic acid (2,4-D)-degrading bacteria from diverse locations was probed with the first three genes of the well-known 2,4-D degradation pathway found in Alcaligenes eutrophus JMP134(pJP4). The majority of strains did not show high levels of homology to the first three genes of the 2,4-D degradation pathway, tfdA, -B, and -C. Most strains showed combinations of tfdA-, B-, and C-like elements that exhibited various degrees of homology to the gene probes. Strains h...

  18. Screening for and isolation and identification of malathion-degrading bacteria: cloning and sequencing a gene that potentially encodes the malathion-degrading enzyme, carboxylestrase in soil bacteria.

    Science.gov (United States)

    Goda, Sayed K; Elsayed, Iman E; Khodair, Taha A; El-Sayed, Walaa; Mohamed, Mervat E

    2010-11-01

    Five malathion-degrading bacterial strains were enriched and isolated from soil samples collected from different agricultural sites in Cairo, Egypt. Malathion was used as a sole source of carbon (50 mg/l) to enumerate malathion degraders, which were designated as IS1, IS2, IS3, IS4, and IS5. They were identified, based on their morphological and biochemical characteristics, as Pseudomonas sp., Pseudomonas putida, Micrococcus lylae, Pseudomonas aureofaciens, and Acetobacter liquefaciens, respectively. IS1 and IS2, which showed the highest degrading activity, were selected for further identification by partial sequence analysis of their 16S rRNA genes. The 16S rRNA gene of IS1 shared 99% similarity with that of Alphaprotoebacterium BAL284, while IS2 scored 100% similarity with that of Pseudomonas putida 32zhy. Malathion residues almost completely disappeared within 6 days of incubation in IS2 liquid cultures. LC/ESI-MS analysis confirmed the degradation of malathion to malathion monocarboxylic and dicarboxylic acids, which formed as a result of carboxylesterase activity. A carboxylesterase gene (CE) was amplified from the IS2 genome by using specifically designed PCR primers. The sequence analysis showed a significant similarity to a known CE gene in different Pseudomonas sp. We report here the isolation of a new malathion-degrading bacteria from soils in Egypt that may be very well adapted to the climatic and environmental conditions of the country. We also report the partial cloning of a new CE gene. Due to their high biodegradation activity, the bacteria isolated from this work merit further study as potential biological agents for the remediation of soil, water, or crops contaminated with the pesticide malathion. PMID:20401686

  19. Isolation and characterization of lignin-degrading bacteria from rainforest soils

    Science.gov (United States)

    The deconstruction of lignin to enhance the release of fermentable sugars from plant cell walls presents a challenge for biofuels production from lignocellulosic biomass. The discovery of novel lignin-degrading enzymes from bacteria could provide advantages over fungal enzymes in terms of their prod...

  20. SIP metagenomics identifies uncultivated Methylophilaceae as dimethylsulphide degrading bacteria in soil and lake sediment.

    Science.gov (United States)

    Eyice, Özge; Namura, Motonobu; Chen, Yin; Mead, Andrew; Samavedam, Siva; Schäfer, Hendrik

    2015-11-01

    Dimethylsulphide (DMS) has an important role in the global sulphur cycle and atmospheric chemistry. Microorganisms using DMS as sole carbon, sulphur or energy source, contribute to the cycling of DMS in a wide variety of ecosystems. The diversity of microbial populations degrading DMS in terrestrial environments is poorly understood. Based on cultivation studies, a wide range of bacteria isolated from terrestrial ecosystems were shown to be able to degrade DMS, yet it remains unknown whether any of these have important roles in situ. In this study, we identified bacteria using DMS as a carbon and energy source in terrestrial environments, an agricultural soil and a lake sediment, by DNA stable isotope probing (SIP). Microbial communities involved in DMS degradation were analysed by denaturing gradient gel electrophoresis, high-throughput sequencing of SIP gradient fractions and metagenomic sequencing of phi29-amplified community DNA. Labelling patterns of time course SIP experiments identified members of the Methylophilaceae family, not previously implicated in DMS degradation, as dominant DMS-degrading populations in soil and lake sediment. Thiobacillus spp. were also detected in (13)C-DNA from SIP incubations. Metagenomic sequencing also suggested involvement of Methylophilaceae in DMS degradation and further indicated shifts in the functional profile of the DMS-assimilating communities in line with methylotrophy and oxidation of inorganic sulphur compounds. Overall, these data suggest that unlike in the marine environment where gammaproteobacterial populations were identified by SIP as DMS degraders, betaproteobacterial Methylophilaceae may have a key role in DMS cycling in terrestrial environments. PMID:25822481

  1. Marine oil degrading bacteria related to oil inputs and surface currents in the western Caribbean Sea

    Energy Technology Data Exchange (ETDEWEB)

    Lizarraga-Partida, M.L.; Vicuna, F.B.I.; Chang, I.W. (Centro de Investigacion Cientifica y de Educacion Superior de Ensenada (CICESE), Ensenada (Mexico))

    1990-01-01

    The distribution of oil degrading bacteria (ODB) and its ratios to viable heterotrophic bacteria (CFU) and direct counts (AODC) were examined in relation to the surface currents of the western Caribbean Sea. High ODB/CFU and ODB/AODC ratios were found, suggesting that chronic sources of hydrocarbons in the region may have a larger impact than those in the southern Gulf of Mexico, where previous studies have been performed. It was concluded that, in western Caribbean waters, the distribution of oil degrading bacteria, or its ratios to CFU or AODC, could be useful indicators of chronic oil inputs originating at the east of the Caribbean Sea, as well as their motions afterwards. (author).

  2. Petroleum Hydrocarbon Degradation Potential of Soil Bacteria Native to the Yellow River Delta

    Institute of Scientific and Technical Information of China (English)

    WANG Zhen-Yu; GAO Dong-Mei; LI Feng-Min; ZHAO Jian; XIN Yuan-Zheng; S.SIMKINS; XING Bao-Shan

    2008-01-01

    The bioremediation potential of bacteria indigenous to soils of the Yellow River Delta in China was evaluated as a treatment option for soil remediation. Petroleum hydrocarbon degraders were isolated from contaminated soil samples from the Yellow River Delta. Four microbial communities and eight isolates were obtained. The optimal temperature, salinity, pH, and the ratios of C, N, and P (C:N:P) for the maximum biodegradation of diesel oil, crude oil, n-alkanes, and polyaromatic hydrocarbons by ndigenous bacteria were determined, and the kinetics changes in microbial communities were monitored. In general, the mixed microbial consortia demonstrated wider catabolic versatility and faster overall rate of hydrocarbon degradation than individual isolates. Our experimental results demonstrated the feasibility of biodegradation of petroleum hydrocarbon by indigenous bacteria for oil remediation in the Yellow River Delta.

  3. Capacity of Aromatic Compound Degradation by Bacteria from Amazon Dark Earth

    Directory of Open Access Journals (Sweden)

    Fernanda Mancini Nakamura

    2014-06-01

    Full Text Available Amazon dark earth (ADE is known for its high organic matter content, biochar concentration and microbial diversity. The biochar amount suggests the existence of microorganisms capable of degrading aromatic hydrocarbons (AHs. In an effort to investigate the influence of bacteria on the resilience and fertility of these soils, we enriched five ADE soils with naphthalene and phenanthrene, and biodegradation assays with phenanthrene and diesel oil were carried out, as well. After DNA extraction, amplification and sequencing of the 16S rRNA bacterial gene, we identified 148 isolates as the Proteobacteria, Firmicutes and Actinobacteria phyla comprising genera closely related to AHs biodegradation. We obtained 128 isolates that degrade diesel oil and 115 isolates that degrade phenanthrene. Some isolates were successful in degrading both substrates within 2 h. In conclusion, the obtained isolates from ADE have degrading aromatic compound activity, and perhaps, the biochar content has a high influence on this.

  4. Halotolerance and effect of salt on hydrophobicity in hydrocarbon-degrading bacteria.

    Science.gov (United States)

    Longang, Adégilns; Buck, Chris; Kirkwood, Kathlyn M

    2016-01-01

    Hydrocarbon-contaminated environments often also experience co-contamination with elevated levels of salt. This paper investigates the occurrence of halotolerance among several hydrocarbon-degrading bacteria, as an initial assessment of the importance of salt contamination to bioremediation strategies. Halotolerance was common, but not ubiquitous, among the 12 hydrocarbon-degrading bacteria tested, with many strains growing at up to 75 or 100 g NaCl L(-1) in rich medium. Greater sensitivity to elevated salt concentrations was observed among aromatics degraders compared to saturates degraders, and in defined medium compared to rich medium. Observed effects of high salt concentrations included increased lag times and decreased maximum growth. Many strains exhibited flocculation at elevated salt concentrations, but this did not correlate to any patterns in cell surface hydrophobicity, measured using the Bacterial Adhesion to Hydrocarbon assay. The occurrence of halotolerance in hydrocarbon-degrading bacteria suggests the potential for native microorganisms to contribute to the bioremediation of oil and salt co-contaminated sites, and indicates the need for a better understanding of the relationship between halotolerance and hydrocarbon biodegradation capabilities. PMID:26915518

  5. DETECTION OF PHENOL DEGRADING BACTERIA AND PSEUDOMONAS PUTIDA IN ACTIVATED SLUDGE BY POLYMERASE CHAIN REACTION

    Directory of Open Access Journals (Sweden)

    H. Movahedyan ، H. Khorsandi ، R. Salehi ، M. Nikaeen

    2009-04-01

    Full Text Available Phenol is one of the organic pollutants in various industrial wastewaters especially petrochemical and oil refining. Biological treatment is one of the considerable choices for removing of phenol present in these wastewaters. Identification of effective microbial species is considered as one of the important priorities for production of the biomass in order to achieve desirable kinetic of biological reactions. Basic purpose of this research is identification of phenol-degrading Pseudomonas Putida in activated sludge by polymerase chain reaction (PCR that has high speed and specificity. In this research, 10 various colonies of phenol-degrading bacteria were isolated from municipal activated sludge and the rate of phenol removal and growth rate of these bacteria were assessed in different concentrations of phenol (200 – 900 mg/L. Confirmation of the largest subunit of multicomponent phenol hydroxylase (LmPH gene and gene coding the N fragment in Pseudomonas Putida-derived methyl phenol operon (DmpN gene through PCR were used for general identification of phenol-degrading bacteria and Pseudomonas Putida, respectively. Presence of a 600 bp (base pairs bond in all of isolated strains indicated that they contain phenol hydroxylase gene. 6 of 10 isolated bacteria were Pseudomonas Putida because they produced a 199 bp PCR product by DmpN primers. According to PCR results in this study, the best phenol-degrading bacteria that can utilize 500 – 600 mg/L phenol completely after 48 hours incubation, belong to Pseudomonas Putida strains. It is clear that use of isolated bacteria can lead to considerable decrease of treatment time as well as promotion of phenol removal rate.

  6. Modelling TCE degradation by a mixed culture of methane-oxidizing bacteria

    DEFF Research Database (Denmark)

    Broholm, Kim; Christensen, Thomas Højlund; Jensen, Bjørn K.

    1992-01-01

    A model describing the growth of bacteria and the degradation of methane and trichloroethylene (TCE) based on the concept of competitive inhibition is proposed. The model has been applied to laboratory batch experiments representing different initial TCE concentrations (50–4300 μg/l) and initial...... methane concentrations (0.53–3.2 mg/l). The proposed model simulated successfully the data obtained for initial methane concentration (less than 1.8 mg/l), causing constant experimental growth conditions during the experiments. This indicates that the interactions between methane and TCE degradation can...... treatment processes and in situ bioremediation schemes for degradation of TCE by methane-oxidizing bacteria....

  7. Photo-assisted electrochemical detection (PAED) following HPLC-UV for the determination of nitro explosives and degradation products

    Science.gov (United States)

    Fedorowski, J.; LaCourse, William R.; Lorah, Michelle M.

    2012-06-01

    Continuous efforts implemented by government agencies such as the United States Geological Survey (USGS) aim to manage and protect the integrity of the environment's natural resources. RDX is one of the most frequently utilized nitramine explosives for mining, demolition and munitions purposes in the United States (US). The degradation of RDX in natural environments is of particular importance as a result of the accumulation of consequential degradation products in nature. Specifically, RDX has the potential to be degraded by microorganisms resulting in hazardous levels of harmful degradation products in soil and groundwater. The necessity for the detection of these particular degradation products is emphasized as a consequence of their toxicity as these products are recognized as potential mutagens. Photo-assisted electrochemical detection (PAED) following HPLC-UV is used to develop an analytical method qualified for the assessment of RDX and degradation products. The technique offers unique selectivity possessed by the photochemical reactor coupled to EC detection serving to eliminate the need for repetitive analysis using different column technologies. Furthermore, on-line sample pretreatment is developed and optimized specifically for the preparation of samples consisting of RDX and degradation products. Analytical figures of merit determined for all target analytes using on-line SPE-HPLC-UV-PAED revealed detection limits in the sub part per billion range for RDX and degradation product MEDINA. The effectiveness of the method is exemplified in collaborative studies with the USGS in monitoring the degradation of RDX and formation of degradation products once the nitro explosive is subject to anaerobic microorganisms WBC-2.

  8. Bacteria and fungi can contribute to nutrients bioavailability and aggregate formation in degraded soils.

    Science.gov (United States)

    Rashid, Muhammad Imtiaz; Mujawar, Liyakat Hamid; Shahzad, Tanvir; Almeelbi, Talal; Ismail, Iqbal M I; Oves, Mohammad

    2016-02-01

    Intensive agricultural practices and cultivation of exhaustive crops has deteriorated soil fertility and its quality in agroecosystems. According to an estimate, such practices will convert 30% of the total world cultivated soil into degraded land by 2020. Soil structure and fertility loss are one of the main causes of soil degradation. They are also considered as a major threat to crop production and food security for future generations. Implementing safe and environmental friendly technology would be viable solution for achieving sustainable restoration of degraded soils. Bacterial and fungal inocula have a potential to reinstate the fertility of degraded land through various processes. These microorganisms increase the nutrient bioavailability through nitrogen fixation and mobilization of key nutrients (phosphorus, potassium and iron) to the crop plants while remediate soil structure by improving its aggregation and stability. Success rate of such inocula under field conditions depends on their antagonistic or synergistic interaction with indigenous microbes or their inoculation with organic fertilizers. Co-inoculation of bacteria and fungi with or without organic fertilizer are more beneficial for reinstating the soil fertility and organic matter content than single inoculum. Such factors are of great importance when considering bacteria and fungi inocula for restoration of degraded soils. The overview of presented mechanisms and interactions will help agriculturists in planning sustainable management strategy for reinstating the fertility of degraded soil and assist them in reducing the negative impact of artificial fertilizers on our environment. PMID:26805616

  9. Glyphosate degradation by immobilized bacteria: laboratory studies showing feasibility for glyphosate removal from waste water.

    Science.gov (United States)

    Heitkamp, M A; Adams, W J; Hallas, L E

    1992-09-01

    To evaluate immobilized bacteria technology for the removal of low levels of glyphosate (N-phosphonomethylglycine) from aqueous industrial effluents, microorganisms with glyphosate-degrading activity obtained from a fill and draw enrichment reactor inoculated with activated sludge were first exposed to glyphosate production wastes containing 500-2000 mg glyphosate/L. The microorganisms were then immobilized by adsorption onto a diatomaceous earth biocarrier contained in upflow Plexiglas columns. The columns were aerated, maintained at pH 7.0-8.0, incubated at 25 degrees C, supplemented with NH4NO3 (50 mg/L), and exposed to glyphosate process wastes pumped upflow through the biocarrier. Glyphosate degradation to aminomethylphosphonic acid was initially > 96% for 21 days of operation at flows yielding hydraulic residence times (HRTs) as short as 42 min. Higher flow rate studies showed > 98% removal of 50 mg glyphosate/L from the waste stream could be achieved at a HRT of 23 min. Glyphosate removal of > 99% at a 37-min HRT was achieved under similar conditions with a column inoculated with a pure culture of Pseudomonas sp. strain LBr, a bacterium known to have high glyphosate-degrading activity. After acid shocking (pH 2.8 for 18 h) of a column of immobilized bacteria, glyphosate-degrading activity was regained within 4 days without reinoculation. Although microbial growth and glyphosate degradation were not maintained under low organic nutrient conditions in the laboratory, the low levels of degradable carbon (45-94 mg/L) in the industrial effluent were sufficient to support prolonged glyphosate-degrading activity. The results demonstrated that immobilized bacteria technology is effective in removing low levels of glyphosate in high-volume liquid waste streams. PMID:1464067

  10. Enhanced desorption of humin-bound phenanthrene by attached phenanthrene-degrading bacteria.

    Science.gov (United States)

    Zhang, Yinping; Wang, Fang; Bian, Yongrong; Kengara, Fredrick Orori; Gu, Chenggang; Zhao, Qiguo; Jiang, Xin

    2012-11-01

    The objective of the study was to test the hypothesis that the attachment of polycyclic aromatic hydrocarbons (PAHs)-degrading bacteria can promote desorption of PAHs from humin, thereby increasing their bioavailability. Biodegradation of humin-bound phenanthrene (PHE) - a model compound for PAHs - was investigated using two PHE-degrading bacteria, Sphingobium sp. PHE3 and Micrococcus sp. PHE9, respectively. Sorption data of PHE to humin fitted well into the modified Freundlich equation. Further, a new sorption band appeared at 1262cm(-1), demonstrating intermolecular interactions between PHE and humin. Interestingly, approximately 65.3% of humin-bound PHE was degraded by both strains, although only about 17.8% of PHE could be desorbed from humin by Tenax extraction. Furthermore, both strains grew well in mineral medium and also attached to humin surfaces for substrate uptake. It is proposed that the attached bacteria could possibly consume PHE on the humin via interactions between bacterial surfaces and humin, thereby overcoming the low PHE bioavailability and resulting in enhanced degradation. PMID:22940304

  11. Influence of Environmental Stressors on the Physiology of Pollutant Degrading Bacteria

    DEFF Research Database (Denmark)

    Svenningsen, Nanna Bygvraa

    compounds. However, soil environments frequently undergo changes, for instance in nutrient and water availability, and microbial cells residing in soils are continuously exposed to various abiotic and biotic insults. Thriving in soil is therefore difficult and conditions are rarely optimal for the microbial...... model degrader bacteria to nutrient- and oxidative stress, two highly relevant stress scenarios in natural environments, and at evaluating the impact of these environmental stress conditions on catabolic gene expression. The results suggest that environmental bacteria, here represented by the toluene...

  12. Infrared Cross-Sections of Nitro-Derivative Vapors: New Spectroscopic Signatures of Explosive Taggants and Degradation Products

    Science.gov (United States)

    Cuisset, Arnaud; Mouret, Gaël; Pirali, Olivier; Gruet, Sébastien; Piau, Gérard Pascal; Fournier, Gilles

    2015-06-01

    Classical explosives such as RDX or TNT exhibit a very low vapor pressure at room temperature and their detection in air requires very sensitive techniques with levels usually better than 1 ppb. To overcome this difficulty, it is not the explosive itself which is detected, but another compound more volatile present in the explosive. This volatile compound can exist naturally in the explosive due to the manufacturing process. For example, in the case of DiNitroToluene (DNT), the molecule is a degradation product of TNT and is required for its manufacture. Ortho-Mononitrotoluene (2-NT) and para-mononitrotoluene (4-NT) can be also used as detection taggants for explosive detection. In this study, using the exceptional properties of the SOLEIL synchrotron source, and adapted multipass-cells, gas phase Far-IR rovibrational spectra of different isomers of mononitrotoluene and dinitrotoluene have been investigated. Room temperature Far-IR cross-sections of the 3 isomer forms of mononitrotoluene have been determined for the lowest frequency vibrational bands located below 700 wn. Cross sections and their temperature dependences have been also measured in the Mid-IR using conventional FTIR spectroscopy probing the nitro-derivatives vapors in a heated multipass-cell. J. C. Oxley, J. L. Smith, W. Luo, J. Brady, Prop. Explos. Pyrotec. 34 (2009) 539-543 A. Cuisset, S. Gruet, O. Pirali, G. Mouret, Spectrochimica Acta Part A, 132 (2014) 838-845.

  13. Enrichment and identification of naphthalene-degrading bacteria from the Persian Gulf.

    Science.gov (United States)

    Hassanshahian, Mehdi; Boroujeni, Negar Amini

    2016-06-15

    Naphthalene is a ubiquitous pollutant of the marine environment, and naphthalene biodegradation has been receiving constant scientific consideration. For cleanup of aromatic contaminated sites, bioremediation methods are considered as economical and safe approaches for the marine environment. The aims of this research are isolation and characterization of naphthalene-degrading bacteria from some marine samples of the Persian Gulf. Fifty four naphthalene-degrading bacteria were isolated from marine samples (sediment and seawater) that are enriched in ONR7a medium with naphthalene as the only carbon source. Some screening tests such as growth at high concentration of naphthalene, bioemulsifier production and surface hydrophobicity were done to select the best and prevalent strains for naphthalene degradation. Determination of the nucleotide sequence of the gene encoding for 16S rRNA shows that these isolated strains belong to these genera: Shewanella, Salegentibacter, Halomonas, Marinobacter, Oceanicola, Idiomarina and Thalassospira. These strains can degrade half of the percentage of naphthalene in 10days of incubation. This research is the first report on isolation of these genera from the Persian Gulf as naphthalene-degrader. PMID:27114087

  14. Oxalate-Degrading Capacities of Gastrointestinal Lactic Acid Bacteria and Urinary Tract Stone Formation

    OpenAIRE

    Mohammad Kargar; Rouhi Afkari; Sadegh Ghorbani-Dalini

    2013-01-01

    Background: Calcium oxalate is one the most significant causes of human kidney stones. Increasing oxalate uptake results in increased urinary oxalate. Elevated urinary oxalate is one the most important causes of kidney stone formation. This study aims to evaluate oxalate-degrading capacity of lactic acid bacteria and its impact on incidence of kidney stone.Materials and Methods: This case-control study was conducted on serum, urinary, and fecal samples. The research population included a tota...

  15. Identification and characterisation of oil sludge degrading bacteria isolated from compost

    Directory of Open Access Journals (Sweden)

    Ubani Onyedikachi

    2016-06-01

    Full Text Available Compounds present in oil sludge such as polycyclic aromatic hydrocarbons (PAHs are known to be cytotoxic, mutagenic and potentially carcinogenic. Microorganisms including bacteria and fungi have been reported to degrade oil sludge components to innocuous compounds such as carbon dioxide, water and salts. In the present study, we isolated different bacteria with PAH-degrading capabilities from compost prepared from oil sludge and animal manures. These bacteria were isolated on a mineral base medium and mineral salt agar plates. A total of 31 morphologically distinct isolates were carefully selected from 5 different compost treatments for identification using polymerase chain reaction (PCR of the 16S rRNA gene with specific primers (universal forward 16S-P1 PCR and reverse 16S-P2 PCR. The amplicons were sequenced and sequences were compared with the known nucleotides from the GenBank. The phylogenetic analyses of the isolates showed that they belong to 3 different clades; Firmicutes, Proteobacteria and Actinobacteria. These bacteria identified were closely related to the genera Bacillus, Arthrobacter, Staphylococcus, Brevibacterium, Variovorax, Paenibacillus, Ralstonia and Geobacillus. The results showed that Bacillus species were predominant in all composts. Based on the results of the degradation of the PAHs in the composts and results of previous studies on bacterial degradation of hydrocarbons in oil, the characteristics of these bacterial isolates suggests that they may be responsible for the breakdown of PAHs of different molecular weights in the composts. Thus, they may be potentially useful for bioremediation of oil sludge during compost bioremediation.

  16. Pengaruh Penambahan Degradable Symbiosis Bacteria Terhadap Penurunan Kadar Sianida (CN-) Dalam Limbah Cair Pabrik Tapioka

    OpenAIRE

    Silitonga, Noaksen

    2014-01-01

    Research about the effect of adding Degra Simba (Degradable Bacteria Symbiosis) to decreased levels of cyanide (CN-) contained in wastewater of tapioca factory has been done. Determination of cyanide (CN-) concentration performed by spectrophotometric method. The principle of measurement is based on the reaction of cyanide (CN-) with kloramin-T and pyridine-barbituric acid that forms a bluish-red solution was measured at a wavelength (λ) = 576 nm. In this research, Degra Simba were added v...

  17. Ecological Dynamics of Toxic Microcystis spp. and Microcystin-Degrading Bacteria in Dianchi Lake, China

    OpenAIRE

    Zhu, Lin; Wu, Yanlong; Song, Lirong; Gan, Nanqin

    2014-01-01

    Toxic cyanobacterial blooms directly threaten both human safety and the ecosystem of surface waters. The widespread occurrence of these organisms, coupled with the tumor-promoting properties of the microcystin toxins that they produce, demands action to mitigate their potential impacts and, thus, a robust understanding of their ecological dynamics. In the present work, the abundance of toxic Microcystis spp. and microcystin (MC)-degrading bacteria in Dianchi Lake, located in Yunnan Province, ...

  18. Diversity of 4-Chloro-2-nitrophenol-Degrading Bacteria in a Waste Water Sample

    Directory of Open Access Journals (Sweden)

    Pankaj Kumar Arora

    2016-01-01

    Full Text Available Eighteen bacterial strains, isolated from a waste water sample collected from a chemically contaminated site, Patancheru (17°32′N 78°16′E/17.53°N 78.27°E, India, were able to decolorize 4-chloro-2-nitrophenol (4C2NP in the presence of an additional carbon source. These eighteen 4C2NP-decolorizing strains have been identified as members of four different genera, including Bacillus, Paenibacillus, Pseudomonas, and Leuconostoc based on the 16S rRNA gene sequencing and phylogenetic analysis. Most of the bacteria (10 belonged to the genus Bacillus and contributed 56% of the total 4C2NP-degrading bacteria, whereas the members of genera Paenibacillus and Pseudomonas represented 22% and 17%, respectively, of total 4C2NP-degrading isolates. There was only one species of Leuconostoc capable of degrading 4C2NP. This is the first report of the diversity of 4C2NP-decolorizing bacteria in a waste water sample. Furthermore, one bacterium, Bacillus aryabhattai strain PC-7, was able to decolorize 4C2NP up to a concentration of 2.0 mM. Gas chromatography-mass spectrometry analysis identified 5-chloro-2-methylbenzoxazole as the final product of 4C2NP decolorization in strain PC-7.

  19. Role of bacteria in the production and degradation of Microcystis cyanopeptides.

    Science.gov (United States)

    Briand, Enora; Humbert, Jean-François; Tambosco, Kevin; Bormans, Myriam; Gerwick, William H

    2016-06-01

    The freshwater cyanobacteria, Microcystis sp., commonly form large colonies with bacteria embedded in their mucilage. Positive and negative interactions between Microcystis species and their associated bacteria have been reported. However, the potential role of bacteria in the production and degradation of cyanobacterial secondary metabolites has not been investigated. In this study, a Microcystis-associated bacterial community was isolated and added to the axenic M. aeruginosaPCC7806 liquid culture. After 3 years of cocultivation, we studied the bacterial genetic diversity adapted to the PCC7806 strain and compared the intra- and extracellular concentration of major cyanopeptides produced by the cyanobacterial strain under xenic and axenic conditions. Mass spectrometric analyses showed that the intracellular concentration of peptides was not affected by the presence of bacteria. Interestingly, the produced peptides were detected in the axenic media but could not be found in the xenic media. This investigation revealed that a natural bacterial community, dominated by Alpha-proteobacteria, was able to degrade a wide panel of structurally varying cyclic cyanopeptides. PMID:26918405

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

    Science.gov (United States)

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

    2005-11-01

    The culturable bacteria colonizing the rhizosphere of plants growing in the area of discharge of a tannery effluent were characterized. Relative proportions of aerobic, denitrifying, and sulfate-reducing bacteria were determined in the rhizosphere of Typha latifolia, Canna indica, and Phragmites australis. Aerobic bacteria were observed to be the most abundant group in the rhizosphere, and plant type did not seem to influence the abundance of the bacterial types analyzed. To isolate bacteria able to degrade polyphenols used in the tannery industry, enrichments were conducted under different conditions. Bacterial cultures were enriched with individual polyphenols (tannins Tara, Quebracho, or Mimosa) or with an undefined mixture of tannins present in the tannery effluent as carbon source. Cultures enriched with the effluent or Tara tannin were able to degrade tannic acid. Six bacterial isolates purified from these mixed cultures were able to use tannic acid as a sole carbon source in axenic culture. On the basis of 16S ribosomal DNA sequence analysis, these isolates were closely related to organisms belonging to the taxa Serratia, Stenotrophomonas maltophilia, Klebsiella oxytoca, Herbaspirillum chlorophenolicum, and Pseudomonas putida. PMID:16341641

  1. Phylogenetic diversity of carbohydrate degrading culturable bacteria from Mandovi and Zuari estuaries, Goa, west coast of India

    Science.gov (United States)

    Khandeparker, Rakhee; Verma, Preeti; Meena, Ram M.; Deobagkar, Deepti D.

    2011-12-01

    Coastal and estuarine waters are highly productive and dynamic ecosystems. The complex carbohydrate composition of the ecosystem would lead to colonisation of microbial communities with abilities to produce an array of complex carbohydrate degrading enzymes. We have examined the abundance and phylogenetic diversity of culturable bacteria with abilities to produce complex carbohydrate degrading enzymes in the Mondovi and Zuari eustauri. It was interesting to note that 65% of isolated bacteria could produce complex carbohydrate degrading enzymes. A majority of these bacteria belonged to Bacillus genera followed by Vibrio, Marinobacter, Exiquinobacterium, Alteromonas, Enterobacter and Aeromonas. Most abundant bacterial genus to degrade hemicellulose and cellulose were Bacillus and Vibrio respectively. Most abundant bacterial genus to degrade hemicellulose and cellulose were Bacillus and Vibrio respectively. It was seen that 46% of Bacillus had ability to degrade both the substrate while only 14% of Vibrio had bifunctionality.

  2. Bacteria-based polythene degradation products: GC-MS analysis and toxicity testing.

    Science.gov (United States)

    Shahnawaz, Mohd; Sangale, Manisha K; Ade, Avinash B

    2016-06-01

    Polythene degradation leads to the production of various by-products depending upon the type of degradation process. The polythene degradation products (PEDP) in the culture supernatant of the two bacteria (Lysinibacillus fusiformis strain VASB14/WL and Bacillus cereus strain VASB1/TS) were analyzed with GC-MS technique. The major by-products in the PEDP in the culture supernatant of L. fusiformis strain VASB14/WL (1,2,3,4 tetra methyl benzene) and B. cereus strain VASB1/TS (1,2,3 trimethyl benzene, 1 ethyl 3,5-dimethyl benzene, 1,4 di methyl 2 ethyl benzene, and dibutyl phthalate) dissolved in diethyl ether were recorded. To assess the environmental applicability of polythene degradation using L. fusiformis strain VASB14/WL and B. cereus strain VASB1/TS at in vitro level. The effect of PEDP produced after 2 months of regular shaking at room temperature on both plants and animal system was studied. No significant decrease in the percent seed germination was recorded with the PEDP of both the bacteria. PEDP produced by L. fusiformis strain VASB14/WL did not report any significant change in germination index (GI) at 10 and 25 %, but least GI (39.66 ± 13.94) was documented at 50 % concentration of PEDP. Highest elongation inhibition rate (53.83 ± 15.71) of Sorghum was also recorded with L. fusiformis and at the same concentration. PMID:26888528

  3. The direct role of aerobic heterotrophic bacteria associated with cyanobacteria in the degradation of oil compounds

    Energy Technology Data Exchange (ETDEWEB)

    Abed, R.M.M. [Max-Planck Institute for Marine Microbiology, Bremen (Germany); Koester, J. [University of Oldenburg (Germany). Institute for Chemistry and Biology of the Marine Environment

    2005-01-01

    This study aimed at evaluating the role of cyanobacteria and their associated aerobic heterotrophic bacteria in biodegradation of petroleum compounds. We investigated the potential of ten non-axenic typical mat-forming cyanobacterial strains to degrade phenanthrene, pristane, n-octadecane, and dibenzothiophene. Five strains (Aphanothece halophyletica, Dactyolococcopsis salina, Halothece strain EPUS, Oscillatoria strain OSC, and Synechocystis strain UNIGA) were able to degrade n-alkanes. In case of the other five strains (Microcoleus chthonoplastes, Oscillatoria sp. MPI 95 OS 01, Halothece strain EPUG, Halomicronema exentricum, and Phormidium strain UNITF) alkanes were not significantly affected. Moderate changes in the concentration of the aromatic compounds were observed for three isolates only. In follow-up experiments with Oscillatoria strain OSC, we demonstrated that the cyanobacteria-associated aerobic heterotrophic bacteria were responsible for the observed biodegradation. The cyanobacteria themselves apparently do not degrade petroleum compounds, but more likely play a significant, indirect role in biodegradation by supporting the growth and activity of the actual degraders. (author)

  4. Ammonium-oxidizing bacteria facilitate aerobic degradation of sulfanilic acid in activated sludge.

    Science.gov (United States)

    Chen, Gang; Ginige, Maneesha P; Kaksonen, Anna H; Cheng, Ka Yu

    2014-01-01

    Sulfanilic acid (SA) is a toxic sulfonated aromatic amine commonly found in anaerobically treated azo dye contaminated effluents. Aerobic acclimatization of SA-degrading mixed microbial culture could lead to co-enrichment of ammonium-oxidizing bacteria (AOB) because of the concomitant release of ammonium from SA oxidation. To what extent the co-enriched AOB would affect SA oxidation at various ammonium concentrations was unclear. Here, a series of batch kinetic experiments were conducted to evaluate the effect of AOB on aerobic SA degradation in an acclimatized activated sludge culture capable of oxidizing SA and ammonium simultaneously. To account for the effect of AOB on SA degradation, allylthiourea was used to inhibit AOB activity in the culture. The results indicated that specific SA degradation rate of the mixed culture was negatively correlated with the initial ammonium concentration (0-93 mM, R²= 0.99). The presence of AOB accelerated SA degradation by reducing the inhibitory effect of ammonium (≥ 10 mM). The Haldane substrate inhibition model was used to correlate substrate concentration (SA and ammonium) and oxygen uptake rate. This study revealed, for the first time, that AOB could facilitate SA degradation at high concentration of ammonium (≥ 10 mM) in an enriched activated sludge culture. PMID:25259503

  5. Isolation and identification of crude oil degrading bacteria from gastropod Haustrum scobina collected from Persian Gulf (Bandar Abbas Shoreline provenance

    Directory of Open Access Journals (Sweden)

    Zinab Bayat

    2016-06-01

    Full Text Available Introduction: Biodegradation is a good alternative rather than chemical and physical methods for cleaning oil contaminated areas. Several factors like crude oil concentration, biosurfactant production, salinity and incubation time affect the biodegradation. Materials and methods: In this study, seawater sample and gastropod were collected from Persian Gulf. To isolate oil degrading bacteria from collected samples, ONR7a medium was used. The strains that had more growth and higher oil removal were selected and identified. The factors such as the effect of different concentrations of oil, incubation time, mixed cultures and salinity on the biodegradation were investigated. Results: Six crude oil degrading bacteria were isolated. Between these bacteria 2 strains were selected based on higher oil removal. These strains belonged to the genus Vibrio and Halomonas. Strains with higher Emulsification activity produce more biosurfactant and have higher oil biodegradation. Growth and oil degradation have increment pattern by prolonging the incubation time. Mixed culture of Vibrio and Halomonas strains have higher rates of degradation rather than culturing with one of them. Increase in crudeoil concentration to 2.5% caused reduction in growth of bacteria and degradation of oil. Discussion and conclusion: The results of this study show that crude oil degrading bacteria have high diversity in Persian Gulf. These bacteria have higher capability for oil degradation thus they can be used for remediation of oil contaminated areas.

  6. Isolation and identification of oil sludge degrading bacteria from production tank Number 9 Masjed Soleiman

    Directory of Open Access Journals (Sweden)

    Yalda Sheyni

    2014-07-01

    Full Text Available   Introduction: “Bioremediation” is one of the most effective methods to remove petroleum contaminants. The aim of the present study is to isolate the indigenous bacteria from the waste petroleum in the Masjed Soleiman No. 9 production tank and to examine the effect of their application on the elimination of petroleum heavy chain hydrocarbons and converting them into light compounds .   Materials and methods: Two percent of petroleum sludge was inoculated to the mineral basal medium and after proliferation of its indigenous bacteria, they were inoculated into the mixture of oil sludge and sand at level of 5%, and the amount of total hydrocarbons and residual oil were measured and compared. The isolates were identified based on biochemical tests and 16S rRNA gene sequencing. Optimization of nitrogen and phosphate sources was done based on growth curves of selected isolates. Gas chromatography was used to determine degradation of sludge hydrocarbons.   Results: In this study, 10 bacterial isolates were isolated from petroleum sludge . Measurement of petroleum total hydrocarbons, using Soxhlet-extraction method, showed that two isolates named MIS1 and MIS2 are able to decompose oil sludge hydrocarbons within 7 days, with the yields of 62% and 72%, respectively. Furthermore, the two isolates reach the end of the logarithmic phase at 48 and 120 hrs, respectively. The best source of nitrogen and phosphate for both isolates was ammonium nitrate and potassium di ­hydrogen phosphate, respectively. The isolates were identified as Arthrobacter aurescens and Pseudomonas aeruginosa , respectively. In gas chromatography analysis it was revealed that Pseudomonas aeruginosa was more potent in degradation of heavy chain hydrocarbons and their conversion to light chain compounds.   Discussion and conclusion: Resident bacteria are present in the oil sludge and are able to degrade the heavy petroleum compounds and convert them into light compounds. These

  7. Bacteria that degrade hazardous waste: The isolation of trichloroethylene-degrading methanotrophic bacteria and development of monoclonal antibodies specific to them

    International Nuclear Information System (INIS)

    Trichloroethylene (TCE), a suspected carcinogen, is one of the most frequently reported groundwater contaminants at hazardous waste sites in the US. An aerobic, methane-oxidizing bacterium was isolated that degrades TCE in pure culture at concentrations commonly observed in contaminated groundwater. Strain 46-1, a Type I methanotrophic bacterium, degraded TCE when growing on methane or methanol, producing CO2 and water-soluble products. Gas chromatography and 14C radiotracer techniques were used to determine the rate, methane dependence, and mechanism of TCE biodegradation. TCE biodegradation by strain 46-1 appears to be a co-metabolic process that occurs when the organism is actively metabolizing a suitable growth substrate such as methane or methanol. Five mouse monoclonal antibodies (MABS) that specifically bind strain 46-1 were prepared by conventional hybridoma technology. These MABS are apparently biochemically distinct and were used to develop enzyme-linked and fluorescent immunoassays to detect strain 46-1 cells in environmental samples. A fluorescent immunoassay utilizing four of these MABS easily distinguished laboratory-grown 46-1 cells from other methanotrophic and heterotrophic bacteria, but failed to detect 46-1 cells in groundwater samples and cultures

  8. Isolation and Identification of Carcinogen Acenaphthene-Degrading Endemic Bacteria from Crude Oil Contaminated Soils around Abadan Refinery

    OpenAIRE

    Farshid Kafilzadeh; Seyedeh Zeynab Hoseyni; Peyman Izedpanah; Houshang Jamali

    2012-01-01

    Background and Objective: PAHs are non-polar organic compounds consisting of two or more fused benzene multi-rings. Among these compounds, acenaphthene is a multi-ring hydrocarbon that occurs abundantly in nature. Use of microorganisms to clean the contaminations of soil can be cheap and effective. The most important acenaphthene-degrading bacteria are pseudomonas, micrococcus, and Bacillus. The goal of this study was to isolate and identify the bacteria which degrade acenaphthene in soils ar...

  9. Phylogenetic diversity of carbohydrate degrading culturable bacteria from Mandovi and Zuari estuaries, Goa, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Khandeparker, R.; Verma, P.; Meena, R.; Deobagkar, D.D.

    . Sequencing reaction products were analyzed with a model 373A automated DNA sequencer (Applied Biosystems). Databases (GenBank) were searched for sequences similarity analysis of the 16S rDNA sequence obtained. The sequences obtained were aligned... that almost 66% of total bacteria isolated from this area had carbohydrate degrading abilities (Fig. 3a). In order to investigate the influence of salinity with abundance of carbohydrate degrading bacteria regression analysis was carried out (Fig. 3b) which...

  10. Enhanced sulfamethoxazole degradation through ammonia oxidizing bacteria co-metabolism and fate of transformation products.

    Science.gov (United States)

    Kassotaki, Elissavet; Buttiglieri, Gianluigi; Ferrando-Climent, Laura; Rodriguez-Roda, Ignasi; Pijuan, Maite

    2016-05-01

    The occurrence of the widely-used antibiotic sulfamethoxazole (SFX) in wastewaters and surface waters has been reported in a large number of studies. However, the results obtained up-to-date have pointed out disparities in its removal. This manuscript explores the enhanced biodegradation potential of an enriched culture of Ammonia Oxidizing Bacteria (AOB) towards SFX. Several sets of batch tests were conducted to establish a link between SFX degradation and specific ammonia oxidation rate. The occurrence, degradation and generation of SFX and some of its transformation products (4-Nitro SFX, Desamino-SFX and N(4)-Acetyl-SFX) was also monitored. A clear link between the degradation of SFX and the nitrification rate was found, resulting in an increased SFX removal at higher specific ammonia oxidation rates. Moreover, experiments conducted under the presence of allylthiourea (ATU) did not present any removal of SFX, suggesting a connection between the AMO enzyme and SFX degradation. Long term experiments (up to 10 weeks) were also conducted adding two different concentrations (10 and 100 μg/L) of SFX in the influent of a partial nitrification sequencing batch reactor, resulting in up to 98% removal. Finally, the formation of transformation products during SFX degradation represented up to 32%, being 4-Nitro-SFX the most abundant. PMID:26938496

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

    Energy Technology Data Exchange (ETDEWEB)

    Bruheim, Per

    1998-12-31

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

  12. Rapid Isolation of Phenol Degrading Bacteria by Fourier Transform Infrared (FTIR) Spectroscopy.

    Science.gov (United States)

    Li, Fei; Song, Wen-jun; Wei, Ji-ping; Wang, Su-ying; Liu, Chong-ji

    2015-05-01

    Phenol is an important chemical engineering material and ubiquitous in industry wastewater, its existence has become a thorny issue in many developed and developing country. More and more stringent standards for effluent all over the world with human realizing the toxicity of phenol have been announced. Many advanced biological methods are applied to industrial wastewater treatment with low cost, high efficiency and no secondary pollution, but the screening of function microorganisms is certain cumbersome process. In our study a rapid procedure devised for screening bacteria on solid medium can degrade phenol coupled with attenuated total reflection fourier transform infrared (ATR-FTIR) which is a detection method has the characteristics of efficient, fast, high fingerprint were used. Principal component analysis (PCA) is a method in common use to extract fingerprint peaks effectively, it couples with partial least squares (PLS) statistical method could establish a credible model. The model we created using PCA-PLS can reach 99. 5% of coefficient determination and validation data get 99. 4%, which shows the promising fitness and forecasting of the model. The high fitting model is used for predicting the concentration of phenol at solid medium where the bacteria were grown. The highly consistent result of two screening methods, solid cultural with ATR-FTIR detected and traditional liquid cultural detected by GC methods, suggests the former can rapid isolate the bacteria which can degrade substrates as well as traditional cumbersome liquid cultural method. Many hazardous substrates widely existed in industry wastewater, most of them has specialize fingerprint peaks detected by ATR-FTIR, thereby this detected method could be used as a rapid detection for isolation of functional microorganisms those can degrade many other toxic substrates. PMID:26415432

  13. Isolation and Identification of Carcinogen Acenaphthene-Degrading Endemic Bacteria from Crude Oil Contaminated Soils around Abadan Refinery

    Directory of Open Access Journals (Sweden)

    Farshid Kafilzadeh

    2012-12-01

    Full Text Available Background and Objective: PAHs are non-polar organic compounds consisting of two or more fused benzene multi-rings. Among these compounds, acenaphthene is a multi-ring hydrocarbon that occurs abundantly in nature. Use of microorganisms to clean the contaminations of soil can be cheap and effective. The most important acenaphthene-degrading bacteria are pseudomonas, micrococcus, and Bacillus. The goal of this study was to isolate and identify the bacteria which degrade acenaphthene in soils around Abadan Refinery and to investigate the relation between the levels of environmental pollution with acenaphthene. Materials and Methods: Soil samples were collected from three areas around Abadan Refinery. The number of the bacteria was counted on the nutrient agar culture with and without acenaphthene. Isolation of the bacteria was done by culturing the samples on acenaphthene broth with a mineral-salt medium, and on an acenaphthene agar medium. Then, the bacteria were identified via biochemical diagnostic tests. Results: The logarithm average of the bacteria was 4.786 ± 0.073 at a medium with acenaphthene, which was 6.671 ± 0.073 less than that of the control medium. The maximum number of degrading bacteria was 7.089 ± 0.089 at Station C, and the minimum number of the degrading bacteria was 4.485 ± 0.089 at Station B. In this study, Bacillus sp, Micrococcus Luteus, Corynebacterium sp, Staphylococcus epidermidis, and Pseudomonas sp bacteria were isolated and identified in terms of frequency, respectively. Conclusion: The results of this study showed that the soil around Abadan Refinery contained a great number of acenaphthene degrading bacteria, especially Bacillus and Micrococcus.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-01

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

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

    Ghabbour, N.; Lamzira, Z.; Thonart, P.; Cidalia, P.; Markaoui, M.; Asehraou, A.

    2011-01-01

    A total of 177 strains of lactic acid bacteria (LAB) were isolated from early-stage Moroccan Picholine green olive fermentation, including Lactobacillus plantarum (44.63%), Lactobacillus pentosus (25.99%), Lactobacillus brevis (9.61%) and Pediococcus pentosaceus (19.77%). All the isolates were screened for their tolerance to olive leaf extract and oleuropein. Most of the isolates (85.3%) were found able to degrade ole...

  17. Isolation and Identification of Sodium Fluoroacetate Degrading Bacteria from Caprine Rumen in Brazil

    OpenAIRE

    Camboim, Expedito K. A.; Almeida, Arthur P.; Tadra-Sfeir, Michelle Z.; Junior, Felício G.; Andrade, Paulo P.; McSweeney, Chris S.; Melo, Marcia A; Franklin Riet-Correa

    2012-01-01

    The objective of this paper was to report the isolation of two fluoroacetate degrading bacteria from the rumen of goats. The animals were adult goats, males, crossbred, with rumen fistula, fed with hay, and native pasture. The rumen fluid was obtained through the rumen fistula and immediately was inoculated 100  μ L in mineral medium added with 20 mmol L−1 sodium fluoroacetate (SF), incubated at 39°C in an orbital shaker. Pseudomonas fluorescens (strain DSM 8341) was used as positive control ...

  18. Molecular identification of the isolated diesel degrading bacteria and optimization studies

    Directory of Open Access Journals (Sweden)

    Janani Prathiba G

    2014-08-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Diesel, a refinery product of crude oil constitutes a major source of pollution in our environment. Poor solubility in water and the higher content in sediments make diesel a potential water pollutant. Bioremediation of contaminated aquatic and soil environments has arisen as an effective technology, with a range of advantages compared to more traditional methods. A total of 9 bacteria were isolated from three petroleum contaminated soil samples and isolate 3 of sample 1 showed maximum degradation potential of diesel in both primary and secondary screening tests. Hence, it was subjected for 16srDNA study and sequence alignment by BLASTN identified the isolate as Pseudomonas aeruginosa strain KEB24. The reaction conditions for efficient diesel degradation by the isolate were optimized.

  19. Performance and dye-degrading bacteria isolation of a hybrid membrane process

    International Nuclear Information System (INIS)

    Textile dyeing wastewater contains harmful compounds, which are toxic to both marine organisms and human beings if it discharged into an aquatic environmental without suitable treatment. In this study, the wastewater containing the azo dye, Reactive Black 5 (RB5), was partially treated in an anaerobic sequencing batch reactor which was further treated either in an aerobic membrane bioreactors (AOMBR) or in combined aerobic membrane bioreactor/reverse osmosis (AOMBR/RO) process. The results showed that in the anaerobic sequencing batch reactor the RB5 dye was degraded to form aromatic amine intermediate metabolites, which were further mineralized in the AOMBR. It was also observed that although all effluents from the AOMBR and AOMBR/RO processes met the Taiwan EPA's effluent criteria, irrespective of which membranes were used in the aerobic tank, the effluent from the AOMBR/RO process met the criteria for reuse for toilet flushing, landscaping, irrigation, and cooling water purposes, where as the AOMBR effluent only met the criteria for cooling water due to incomplete color removal. Five anaerobic high dye-degrading bacteria were isolated, which were identified to be the same species of Lactococcus lactis by 16S rRNA sequencing. The L. lactis showed complete degradation of RB5 and further studies showed that it can also able to degrade Reactive Red 120 and Reactive Yellow 84 efficiently within 6 h.

  20. Oxalate-Degrading Capacities of Gastrointestinal Lactic Acid Bacteria and Urinary Tract Stone Formation

    Directory of Open Access Journals (Sweden)

    Mohammad Kargar

    2013-10-01

    Full Text Available Background: Calcium oxalate is one the most significant causes of human kidney stones. Increasing oxalate uptake results in increased urinary oxalate. Elevated urinary oxalate is one the most important causes of kidney stone formation. This study aims to evaluate oxalate-degrading capacity of lactic acid bacteria and its impact on incidence of kidney stone.Materials and Methods: This case-control study was conducted on serum, urinary, and fecal samples. The research population included a total of 200 subjects divided in two equal groups. They were selected from the patients with urinary tract stones, visiting urologist, and also normal people. The level of calcium, oxalate, and citrate in the urinary samples, parathyroid and calcium in the serum samples, and degrading activity of fecal lactobacillus strains of all the subjects were evaluated. Then, data analysis was carried out using SPSS-11.5, χ2 test, Fisher’s exact test, and analysis of variance. Results: The results revealed that the patients had higher urinary level of oxalate and calcium, as well as higher serum level of parathyroid hormone than normal people. In contrast, urinary level of citrate was higher in normal people. In addition, there was a significant difference between the oxalate-degrading capacities of lactobacillus isolated from the patients and their normal peers.Conclusion: Reduction of digestive lactobacillus-related oxalate-degrading capacity and increased serum level of parathyroid hormone can cause elevated urinary level of oxalate and calcium in people with kidney stone.

  1. [Bacteria that degrade low-molecular linear epsilon-caprolactam olygomers].

    Science.gov (United States)

    Esikova, T Z; Akatova, E V; Taran, S A

    2014-01-01

    Five bacterial strains with the unique ability to utilize low-molecular linear caprolactam olygomers (nylon olygomers) were isolated from soil samples contaminated with industrial wastes of epsilon-caprolactam. Based on the properties studied and also on the analysis of 16S rRNA gene nucleotide sequences, the strains BS2,BS3, BS9, BS38, and BS57 were classified to the general Arthrobacter, Brevibacterium, Microbacteriun, Gulosibacter, and Achromobacter, respectively. All of the strains also utilized 6-aminohexanoic and adipic acids, which are intermidiates of the epsilon-caprolactam catabolism. This indirectly points to the fact that degradation of olygomers in these bacteria occurs via the monomer degradation pathway. The BS9 and BS57 strains utilized only olygomers of the epsilon-caprolactam, while BS2, BS3, and BS38 also degraded epsilon-caprolactam and its homologs, enantolactam and caprylolactam, which differentiates the latter from the previously known degraders of olygomers and suggests the presence in these strains of enzymes with lactam hydrolase activity, in addition to 6-aminohexanoate-dimer hydrolase. PMID:25707105

  2. Isolation of Cellulose-Degrading Bacteria and Determination of Their Cellulolytic Potential

    Directory of Open Access Journals (Sweden)

    Pratima Gupta

    2012-01-01

    Full Text Available Eight isolates of cellulose-degrading bacteria (CDB were isolated from four different invertebrates (termite, snail, caterpillar, and bookworm by enriching the basal culture medium with filter paper as substrate for cellulose degradation. To indicate the cellulase activity of the organisms, diameter of clear zone around the colony and hydrolytic value on cellulose Congo Red agar media were measured. CDB 8 and CDB 10 exhibited the maximum zone of clearance around the colony with diameter of 45 and 50 mm and with the hydrolytic value of 9 and 9.8, respectively. The enzyme assays for two enzymes, filter paper cellulase (FPC, and cellulase (endoglucanase, were examined by methods recommended by the International Union of Pure and Applied Chemistry (IUPAC. The extracellular cellulase activities ranged from 0.012 to 0.196 IU/mL for FPC and 0.162 to 0.400 IU/mL for endoglucanase assay. All the cultures were also further tested for their capacity to degrade filter paper by gravimetric method. The maximum filter paper degradation percentage was estimated to be 65.7 for CDB 8. Selected bacterial isolates CDB 2, 7, 8, and 10 were co-cultured with Saccharomyces cerevisiae for simultaneous saccharification and fermentation. Ethanol production was positively tested after five days of incubation with acidified potassium dichromate.

  3. Isolation and Identification of Sodium Fluoroacetate Degrading Bacteria from Caprine Rumen in Brazil

    Directory of Open Access Journals (Sweden)

    Expedito K. A. Camboim

    2012-01-01

    Full Text Available The objective of this paper was to report the isolation of two fluoroacetate degrading bacteria from the rumen of goats. The animals were adult goats, males, crossbred, with rumen fistula, fed with hay, and native pasture. The rumen fluid was obtained through the rumen fistula and immediately was inoculated 100 μL in mineral medium added with 20 mmol L−1 sodium fluoroacetate (SF, incubated at 39°C in an orbital shaker. Pseudomonas fluorescens (strain DSM 8341 was used as positive control for fluoroacetate dehalogenase activity. Two isolates were identified by 16S rRNA gene sequencing as Pigmentiphaga kullae (ECPB08 and Ancylobacter dichloromethanicus (ECPB09. These bacteria degraded sodium fluoroacetate, releasing 20 mmol L−1 of fluoride ion after 32 hours of incubation in Brunner medium containing 20 mmol L−1 of SF. There are no previous reports of fluoroacetate dehalogenase activity for P. kullae and A. dichloromethanicus. Control measures to prevent plant intoxication, including use of fences, herbicides, or other methods of eliminating poisonous plants, have been unsuccessful to avoid poisoning by fluoroacetate containing plants in Brazil. In this way, P. kullae and A. dichloromethanicus may be used to colonize the rumen of susceptible animals to avoid intoxication by fluoroacetate containing plants.

  4. Phytic acid degrading lactic acid bacteria in tef-injera fermentation.

    Science.gov (United States)

    Fischer, Maren M; Egli, Ines M; Aeberli, Isabelle; Hurrell, Richard F; Meile, Leo

    2014-11-01

    Ethiopian injera, a soft pancake, baked from fermented batter, is preferentially prepared from tef (Eragrostis tef) flour. The phytic acid (PA) content of tef is high and is only partly degraded during the fermentation step. PA chelates with iron and zinc in the human digestive tract and strongly inhibits their absorption. With the aim to formulate a starter culture that would substantially degrade PA during injera preparation, we assessed the potential of microorganisms isolated from Ethiopian household-tef fermentations to degrade PA. Lactic acid bacteria (LAB) were found to be among the dominating microorganisms. Seventy-six isolates from thirteen different tef fermentations were analyzed for phytase activity and thirteen different isolates of seven different species were detected to be positive in a phytase screening assay. In 20-mL model tef fermentations, out of these thirteen isolates, the use of Lactobacillus (L.) buchneri strain MF58 and Pediococcus pentosaceus strain MF35 resulted in lowest PA contents in the fermented tef of 41% and 42%, respectively of its initial content. In comparison 59% of PA remained when spontaneously fermented. Full scale tef fermentation (0.6L) and injera production using L. buchneri MF58 as culture additive decreased PA in cooked injera from 1.05 to 0.34±0.02 g/100 g, representing a degradation of 68% compared to 42% in injera from non-inoculated traditional fermentation. The visual appearance of the pancakes was similar. The final molar ratios of PA to iron of 4 and to zinc of 12 achieved with L. buchneri MF58 were decreased by ca. 50% compared to the traditional fermentation. In conclusion, selected LAB strains in tef fermentations can degrade PA, with L. buchneri MF58 displaying the highest PA degrading potential. The 68% PA degradation achieved by the application of L. buchneri MF58 would be expected to improve human zinc absorption from tef-injera, but further PA degradation is probably necessary if iron absorption has to

  5. Aquatic Organisms and Petroleum Hydrocarbon Degrading Bacteria Associated with Their Digestive System

    Directory of Open Access Journals (Sweden)

    Janina Šyvokienė

    2014-01-01

    Full Text Available Laboratory investigation was carried out on the abundance and composition of bacteria in the digestive system of a total of 35 specimens, including bivalve molluscs, i.e. swan mussel Anodonta cygnea (Linnaeus, 1758 from Lake Spėra (Širvintos district and swollen river mussel Unio tumidus (Philipson, 1788 from the Curonian Lagoon near Juodkrantė, zebra mussel (Dreissena polymorpha from the Curonian Lagoon near Juodkrantė and an anostracan – Chirocephalus josephinae (Grube, 1853 from a pond in Ilčiukai village, Utena district, and in the water of related water bodies. Studies on bivalve molluscs (swan mussel and swollen river mussel, zebra mussel and an anostracan – Chirocephalus josephinae, as well as microbiological investigation of water demonstrated that the number of microorganisms in the digestive system of mollusc and anostracan species fluctuated and varied between different species and water bodies. The greatest percentage of HDB among total heterotrophic bacteria was found in the digestive system of swollen river mussels (21.53% and in zebra mussels (19.99% caught in the Curonian Lagoon and in the water of the lagoon (24%. A considerably smaller percentage of HDB was detected in the digestive system of swan mussels from Lake Spėra (17.6% and in the water of the lake (16.66%. The smallest percentage of HDB was found in the digestive system of Chirocephalus josephinae (6.63% and in the water of the Ilčiukai pond (2.72%. According to the values of abundance of petroleum hydrocarbon-degrading bacteria (HDB and total coliform bacteria (TCFB in the digestive system of aquatic organisms we can state that the water ecosystem of Ilčiukai pond was the least contaminated with petroleum, its products and sewage water, and the Curonian Lagoon water ecosystem was the most contaminated. Abundance of petroleum hydrocarbons degrading bacteria could be used as a bioindicator reflecting the level of ecosystem pollution petroleum and its

  6. Aquatic Organisms and Petroleum Hydrocarbon Degrading Bacteria Associated with Their Digestive System

    Directory of Open Access Journals (Sweden)

    Janina Šyvokienė

    2013-12-01

    Full Text Available Laboratory investigation was carried out on the abundance and composition of bacteria in the digestive system of a total of 35 specimens, including bivalve molluscs, i.e. swan mussel Anodonta cygnea (Linnaeus, 1758 from Lake Spėra (Širvintos district and swollen river mussel Unio tumidus (Philipson, 1788 from the Curonian Lagoon near Juodkrantė, zebra mussel (Dreissena polymorpha from the Curonian Lagoon near Juodkrantė and an anostracan – Chirocephalus josephinae (Grube, 1853 from a pond in Ilčiukai village, Utena district, and in the water of related water bodies. Studies on bivalve molluscs (swan mussel and swollen river mussel, zebra mussel and an anostracan – Chirocephalus josephinae, as well as microbiological investigation of water demonstrated that the number of microorganisms in the digestive system of mollusc and anostracan species fluctuated and varied between different species and water bodies. The greatest percentage of HDB among total heterotrophic bacteria was found in the digestive system of swollen river mussels (21.53% and in zebra mussels (19.99% caught in the Curonian Lagoon and in the water of the lagoon (24%. A considerably smaller percentage of HDB was detected in the digestive system of swan mussels from Lake Spėra (17.6% and in the water of the lake (16.66%. The smallest percentage of HDB was found in the digestive system of Chirocephalus josephinae (6.63% and in the water of the Ilčiukai pond (2.72%. According to the values of abundance of petroleum hydrocarbon-degrading bacteria (HDB and total coliform bacteria (TCFB in the digestive system of aquatic organisms we can state that the water ecosystem of Ilčiukai pond was the least contaminated with petroleum, its products and sewage water, and the Curonian Lagoon water ecosystem was the most contaminated. Abundance of petroleum hydrocarbons degrading bacteria could be used as a bioindicator reflecting the level of ecosystem pollution petroleum and its

  7. Sulfur Isotopic Fractionation of Carbonyl Sulfide during Degradation by Soil Bacteria.

    Science.gov (United States)

    Kamezaki, Kazuki; Hattori, Shohei; Ogawa, Takahiro; Toyoda, Sakae; Kato, Hiromi; Katayama, Yoko; Yoshida, Naohiro

    2016-04-01

    We performed laboratory incubation experiments on the degradation of gaseous phase carbonyl sulfide (OCS) by soil bacteria to determine its sulfur isotopic fractionation constants ((34)ε). Incubation experiments were conducted using strains belonging to the genera Mycobacterium, Williamsia, and Cupriavidus isolated from natural soil environments. The (34)ε values determined were -3.67 ± 0.33‰, -3.99 ± 0.19‰, -3.57 ± 0.22‰, and -3.56 ± 0.23‰ for Mycobacterium spp. strains THI401, THI402, THI404, and THI405; -3.74 ± 0.29‰ for Williamsia sp. strain THI410; and -2.09 ± 0.07‰ and -2.38 ± 0.35‰ for Cupriavidus spp. strains THI414 and THI415. Although OCS degradation rates divided by cell numbers (cell-specific activity) were different among strains of the same genus, the (34)ε values for same genus showed no significant differences. Even though the numbers of bacterial species examined were limited, our results suggest that (34)ε values for OCS bacterial degradation depend not on cell-specific activities, but on genus-level biological differences, suggesting that (34)ε values are dependent on enzymatic and/or membrane properties. Taking our (34)ε values as representative for bacterial OCS degradation, the expected atmospheric changes in δ(34)S values of OCS range from 0.5‰ to 0.9‰, based on previously reported decreases in OCS concentrations at Mt. Fuji, Japan. Consequently, tropospheric observation of δ(34)S values for OCS coupled with (34)ε values for OCS bacterial degradation can potentially be used to investigate soil as an OCS sink. PMID:26967120

  8. Production of rhamnolipids and diesel oil degradation by bacteria isolated from soil contaminated by petroleum.

    Science.gov (United States)

    Leite, Giuseppe G F; Figueirôa, Juciane V; Almeida, Thiago C M; Valões, Jaqueline L; Marques, Walber F; Duarte, Maria D D C; Gorlach-Lira, Krystyna

    2016-03-01

    Biosurfactants are microbial secondary metabolites. The most studied are rhamnolipids, which decrease the surface tension and have emulsifying capacity. In this study, the production of biosurfactants, with emphasis on rhamnolipids, and diesel oil degradation by 18 strains of bacteria isolated from waste landfill soil contaminated by petroleum was analyzed. Among the studied bacteria, gram-positive endospore forming rods (39%), gram positive rods without endospores (17%), and gram-negative rods (44%) were found. The following methods were used to test for biosurfactant production: oil spreading, emulsification, and hemolytic activity. All strains showed the ability to disperse the diesel oil, while 77% and 44% of the strains showed hemolysis and emulsification of diesel oil, respectively. Rhamnolipids production was observed in four strains that were classified on the basis of the 16S rRNA sequences as Pseudomonas aeruginosa. Only those strains showed the rhlAB gene involved in rhamnolipids synthesis, and antibacterial activity against Escherichia coli, P. aeruginosa, Staphylococcus aureus, Bacillus cereus, Erwinia carotovora, and Ralstonia solanacearum. The highest production of rhamnolipids was 565.7 mg/L observed in mineral medium containing olive oil (pH 8). With regard to the capacity to degrade diesel oil, it was observed that 7 strains were positive in reduction of the dye 2,6-dichlorophenolindophenol (2,6-DCPIP) while 16 had the gene alkane mono-oxygenase (alkB), and the producers of rhamnolipids were positive in both tests. Several bacterial strains have shown high potential to be explored further for bioremediation purposes due to their simultaneous ability to emulsify, disperse, and degrade diesel oil. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 32:262-270, 2016. PMID:26588432

  9. Rhizosphere of Avicennia marina (Forsk.) Vierh. as a landmark for polythene degrading bacteria.

    Science.gov (United States)

    Shahnawaz, Mohd; Sangale, Manisha K; Ade, Avinash B

    2016-07-01

    Due to high durability, cheap cost, and ease of manufacture, 311 million tons of plastic-based products are manufactured around the globe per annum. The slow/least rate of plastic degradation leads to generation of million tons of plastic waste per annum, which is of great environmental concern. Of the total plastic waste generated, polythene shared about 64 %. Various methods are available in the literature to tackle with the plastic waste, and biodegradation is considered as the most accepted, eco-friendly, and cost-effective method of polythene waste disposal. In the present study, an attempt has been made to isolate, screen, and characterize the most efficient polythene degrading bacteria by using rhizosphere soil of Avicennia marina as a landmark. From 12 localities along the west coast of India, a total of 123 bacterial isolates were recorded. Maximum percent weight loss (% WL; 21.87 ± 6.37 %) was recorded with VASB14 at pH 3.5 after 2 months of shaking at room temperature. Maximum percent weight gain (13.87 ± 3.6 %) was reported with MANGB5 at pH 7. Maximum percent loss in tensile strength (% loss in TS; 87.50 ± 4.8 %) was documented with VASB1 at pH 9.5. The results based on the % loss in TS were only reproducible. Further, the level of degradation was confirmed by scanning electron microscopic (SEM) and Fourier transform infrared spectroscopy (FTIR) analysis. In SEM analysis, scions/crakes were found on the surface of the degraded polythene, and mass of bacterial cell was also recorded on the weight-gained polythene strips. Maximum reduction in carbonyl index (4.14 %) was recorded in untreated polythene strip with Lysinibacillus fusiformis strain VASB14/WL. Based on 16S ribosomal RNA (rRNA) gene sequence homology, the most efficient polythene degrading bacteria were identified as L. fusiformis strainVASB14/WL and Bacillus cereus strain VASB1/TS. PMID:27072028

  10. Detection of Toluene Degradation in Bacteria Isolated from Oil Contaminated Soils

    International Nuclear Information System (INIS)

    Toluene (C7H8) a hydrocarbon in crude oil, is a common contaminant in soil and groundwater. In this study, the ability to degrade toluene was investigated from twelve bacteria isolates which were isolated from soil contaminated with oil. Out of 12 bacterial isolates tested, most of Pseudomonas sp. showed the capability to grow in 1 mM of toluene compared with other isolates on the third day of incubation. Based on enzyme assays towards toluene monooxygenase, Pseudomonas aeruginosa UKMP-14T and Bacillus cereus UKMP-6G were shown to have the highest ability to degrade toluene. The toluene monooxygenase activity was analysed by using two calorimetric methods, Horseradish peroxidase (HRP) and indole-indigo. Both of the methods measured the production of catechol by the enzymatic reaction of toluene monooxygenase. In the HRP assay, the highest enzyme activity was 0.274 U/ mL, exhibited by Pseudomonas aeruginosa UKMP-14T. However, for indole-indigo assay, Bacillus cereus UKMP-6G produced the highest enzyme activity of 0.291 U/ ml. Results from both experiments showed that Pseudomonas aeruginosa UKMP-14T and Bacillus cereus UKMP-6G were able to degrade toluene. (author)

  11. Insights into the genetic diversity of initial dioxygenases from PAH-degrading bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Moser, R.; Stahl, U. [Technische Univ. Berlin, Inst. fuer Biotechnologie, Mikrobiologie und Genetik, Berlin (Germany)

    2001-07-01

    Alpha subunit genes of initial polyaromatic hydrocarbon (PAH) dioxygenases were used as targets for the PCR detection of PAH-degrading strains of the genera Pseudomonas, Comamonas and Rhodococcus which were obtained from activated sludge or soil samples. Sequence analysis of PCR products from several Pseudomonas strains showed that alpha subunits (nahAc allele) of this genus are highly conserved. PCR primers for the specific detection of alpha subunit genes of initial PAH dioxygenases from Pseudomonas strains were not suitable for detecting the corresponding genes from the genera Comamonas and Rhodococcus. Southern analysis using a heterologous gene probe derived from the P. putida OUS82 PAH dioxygenase alpha subunit identified segments of the PAH-degradation gene cluster from C. testosteroni strain H. Parts of this gene cluster containing three subunits of the initial PAH dioxygenase were isolated. These three subunits [ferredoxin (pahAb), alpha (pahAc) and beta (pahAd) subunit] were amplified by PCR as one fragment and expressed in Escherichia coli DH5{alpha}, resulting in an active initial dioxygenase with the ability to transform indole and phenanthrene. The DNA sequence alignment of alpha subunits from C. testosteroni H and various PAH-degrading bacteria permitted the design of new primers and oligonucleotide probes which are useful for the detection of the initial PAH dioxygenases from strains of Pseudomonas, Comamonas and Rhodococcus. (orig.)

  12. Sequential Isolation of Saturated, Aromatic, Resinic and Asphaltic Fractions Degrading Bacteria from Oil Contaminated Soil in South Sumatera

    Directory of Open Access Journals (Sweden)

    Pingkan Aditiawati

    2012-04-01

    Full Text Available Sequential isolation has been conducted to obtain isolates of saturated, aromatic, resin, and asphaltene fractions degrading bacteria from oil contaminated sites. Five soil samples were collected from South Sumatera. These were analyzed using soil extract medium enriched with oil recovery or Remaining-Oil recovery Degradated (ROD as sole carbon and energy sources according to the isolation stage. ROD at the end of every isolation stage analyzed oil fractions by use of the SARA analysis method. Six isolates of bacteria have been selected, one isolate was fraction saturates degrading bacteria that are Mycobacterium sp. T1H2D4-7 at degradation rate 0.0199 mgs/h with density 8.4x106 cfu/g from stage I. The isolate T2H1D2-4, identified as Pseudomonas sp. was fraction aromatics degrading bacteria at accelerate 0.0141 mgs/h with density 5.1x106 cfu/g are obtained at stage II. Two isolates namely Micrococcus sp. T3H2D4-2 and Pseudomonas sp. T1H1D5-5 were fraction resins degrading bacteria by accelerate 0.0088 mgs/h at density 5.6x106 cfu/g and 0.0089 mgs/h at density 5.7x106 cfu/g are obtained at stage III. Isolation of stage IV has been obtained two isolates Pseudomonas sp. T4H1D3-1and Pseudomonas sp. T4H3D5-4 were fraction asphaltenes degrading bacteria by accelerate 0.0057 mgs/h at density 5.6x106 cfu/g and accelerate 0.0058 mgs/h at density 5.7x106 cfu/g.

  13. Harboring oil-degrading bacteria: a potential mechanism of adaptation and survival in corals inhabiting oil-contaminated reefs.

    Science.gov (United States)

    Al-Dahash, Lulwa M; Mahmoud, Huda M

    2013-07-30

    Certain coral reef systems north of the Arabian Gulf are characterized by corals with a unique ability to thrive and flourish despite the presence of crude oil continuously seeping from natural cracks in the seabed. Harboring oil-degrading bacteria as a part of the holobiont has been investigated as a potential mechanism of adaptation and survival for corals in such systems. The use of conventional and molecular techniques verified a predominance of bacteria affiliated with Gammaproteobacteria, Actinobacteria and Firmicutes in the mucus and tissues of Acropora clathrata and Porites compressa. These bacteria were capable of degrading a wide range of aliphatic (C9-C28) aromatic hydrocarbons (Phenanthrene, Biphenyl, Naphthalene) and crude oil. In addition, microcosms supplied with coral samples and various concentrations of crude oil shifted their bacterial population toward the more advantageous types of oil degraders as oil concentrations increased. PMID:23014479

  14. IDENTIFICATION, MOLECULAR CHARACTERIZATION AND EVALUATION OF SOME RUMINAL BACTERIA THAT CATALYZE AND DEGRADE PLANT CELLULOSIC MATERIALS

    Directory of Open Access Journals (Sweden)

    Ahmed A. Mansour

    2014-01-01

    Full Text Available In the last few years there was a growing economic awareness about plant wastes and use it in compost production or in feeding of farm animals, some of these wastes are useless and cause a lot of problems in Egyptian environment. This study was designed to isolate, identify and evaluate some ruminal bacterial isolates to facilitate the in vitro degradation of certain local agro-industrial wastes (rice straw and corn stalks. Two bacterial isolates were isolated from rumen fluid of some Egyptian cattle and identified as Fibrobacter succinogenes and Ruminococcus albus depending on morphological, biochemical identification and molecular characterization using 16S rRNA genes. Two degenerate primers were used to detect about 1.6 kb PCR fragment, a partial sequences (709 and 401 bp were sequenced for F. succinogenes and R. albus respectively. The highest similarity was detected for both isolates which were 57% with Streptomyces sp. for F. succinogenes and 77% with Enterobacter sp. for R. albus. The two isolates were subjected in-vitro to catalyze and degrade rice straw and corn stalks. After four weeks of fermentation, degradation was measured depending on the bacterial growth and changes in chemical components of the degraded materials. The degradation of corn stalks was highly significant comparing to rice straw which inoculated by F. succinogenes or R. albus. Analysis of the chemical composition showed a decrease in Organic Matter (OM, Crude Fiber (CF, Neutral Detergent Fiber (NDF, Acid Detergent Fiber (ADF, cellulose and hemicellulose content. The inoculum 7.5 mL/50 g of Ruminococcus albus is more efficient to degrade rice straw or corn stalks in four weeks fermentation period. Corn stalks are better than rice straw to enhance the cellulolytic bacteria to grow in all treatments.

  15. Influence of compost amendments on the diversity of alkane degrading bacteria in hydrocarbon contaminated soils

    Directory of Open Access Journals (Sweden)

    MichaelSchloter

    2014-03-01

    Full Text Available Alkane degrading microorganisms play an important role for bioremediation of petrogenic contaminated environments. In this study, we investigated the effects of compost addition on the diversity of alkane monooxygenase gene (alkB harboring bacteria in oil-contaminated soil originated from an industrial zone in Celje, Slovenia, to improve our understanding about the bacterial community involved in alkane degradation and the effects of amendments. Soil without any amendments (control soil and soil amended with compost of different maturation stages, i 1 year and ii 2 weeks, were incubated under controlled conditions in a microcosm experiment and sampled after 0, 6, 12 and 36 weeks of incubation. By using quantitative real-time PCR higher number of alkB genes could be detected in soil samples with compost compared to the control soil after 6, 12 and 36 weeks mainly if the less maturated compost was added. To get an insight into the composition of the alkB harboring microbial communities, we performed next generation sequencing of alkB gene fragment amplicons. Richness and diversity of alkB gene harboring prokaryotes was higher in soil mixed with compost compared to control soil after 6, 12 and 36 weeks again with stronger effects of the less maturated compost. Comparison of communities detected in different samples and time points based on principle component analysis revealed that the addition of compost in general stimulated the abundance of alkB harboring Actinobacteria during the experiment independent from the maturation stage of the compost compared to the control soils. In addition alkB harboring proteobacteria like Shewanella or Hydrocarboniphaga as well as proteobacteria of the genus Agrobacterium responded positively to the addition of compost to soil The amendment of the less maturated compost resulted in addition in a large increase of alkB harboring bacteria of the Cytophaga group (Microscilla mainly at the early sampling

  16. Phenolic acid degradation potential and growth behavior of lactic acid bacteria in sunflower substrates.

    Science.gov (United States)

    Fritsch, Caroline; Heinrich, Veronika; Vogel, Rudi F; Toelstede, Simone

    2016-08-01

    Sunflower flour provides a high content of protein with a well-balanced amino acid composition and is therefore regarded as an attractive source for protein. The use for human nutrition is hindered by phenolic compounds, mainly chlorogenic acid, which can lead under specific circumstances to undesirable discolorations. In this study, growth behavior and degradation ability of chlorogenic acid of four lactic acid bacteria were explored. Data suggested that significant higher fermentation performances on sunflower flour as compared to sunflower protein concentrate were reached by Lactobacillus plantarum, Pediococcus pentosaceus, Lactobacillus gasseri and Bifidobacterium animalis subsp. lactis. In fermentation with the latter two strains reduced amounts of chlorogenic acid were observed in sunflower flour (-11.4% and -19.8%, respectively), which were more pronounced in the protein concentrate (-50.7% and -95.6%, respectively). High tolerances against chlorogenic acid and the cleavage product quinic acid with a minimum inhibitory concentration (MIC) of ≥20.48 mg/ml after 48 h were recorded for all strains except Bifidobacterium animalis subsp. lactis, which was more sensitive. The second cleavage compound, caffeic acid revealed a higher antimicrobial potential with MIC values of 0.64-5.12 mg/ml. In this proof of concept study, degradation versus inhibitory effect suggest the existence of basic mechanisms of interaction between phenolic acids in sunflower and lactic acid bacteria and a feasible way to reduce the chlorogenic acid content, which may help to avoid undesired color changes. PMID:27052717

  17. Sequential Isolation of Saturated, Aromatic, Resinic and Asphaltic Fractions Degrading Bacteria from Oil Contaminated Soil in South Sumatera

    OpenAIRE

    Pingkan Aditiawati; Munawar; Dea Indriani Astuti

    2012-01-01

    Sequential isolation has been conducted to obtain isolates of saturated, aromatic, resin, and asphaltene fractions degrading bacteria from oil contaminated sites. Five soil samples were collected from South Sumatera. These were analyzed using soil extract medium enriched with oil recovery or Remaining-Oil recovery Degradated (ROD) as sole carbon and energy sources according to the isolation stage. ROD at the end of every isolation stage analyzed oil fractions by use of the SARA analysis metho...

  18. Apparent Contradiction: Psychrotolerant Bacteria from Hydrocarbon-Contaminated Arctic Tundra Soils That Degrade Diterpenoids Synthesized by Trees

    OpenAIRE

    Yu, Zhongtang; Stewart, Gordon R.; Mohn, William W.

    2000-01-01

    Resin acids are tricyclic terpenoids occurring naturally in trees. We investigated the occurrence of resin acid-degrading bacteria on the Arctic tundra near the northern coast of Ellesmere Island (82°N, 62°W). According to most-probable-number assays, resin acid degraders were abundant (103 to 104 propagules/g of soil) in hydrocarbon-contaminated soils, but they were undetectable (

  19. The effect of inoculation of an indigenous bacteria on the early growth of Acacia farnesiana in a degraded area

    OpenAIRE

    Eliane Ceccon; Anayeli Almazo-Rogel; Esperanza Martínez-Romero; Ivonne Toledo

    2012-01-01

    Restoration of native vegetation and fuelwood production are important environmental pending goals for Mexico, where years of wrong management practices resulted in ecosystemic degradation and fuelwood scarcity. In degraded areas, native rhizobial strains are often undetectable, therefore, the restoration of natural vegetation associated with an effective nodulation of the leguminous trees is mostly appropriate. Sinorhizobium americanum is a native nitrogen-fixing bacteria isolated from nodul...

  20. The cultivable surface microbiota of the brown alga Ascophyllum nodosum is enriched in macroalgal-polysaccharide-degrading bacteria

    Directory of Open Access Journals (Sweden)

    Marjolaine Martin

    2015-12-01

    Full Text Available Bacteria degrading algal polysaccharides are key players in the global carbon cycle and in algal biomass recycling. Yet the water column, which has been studied largely by metagenomic approaches, is poor in such bacteria and their algal-polysaccharide-degrading enzymes. Even more surprisingly, the few published studies on seaweed-associated microbiomes have revealed low abundances of such bacteria and their specific enzymes. However, as macroalgal cell-wall polysaccharides do not accumulate in nature, these bacteria and their unique polysaccharidases must not be that uncommon. We, therefore, looked at the polysaccharide-degrading activity of the cultivable bacterial subpopulation associated with Ascophyllum nodosum. From A. nodosum triplicates, 324 bacteria were isolated and taxonomically identified. Out of these isolates, 78 (~25% were found to act on at least one tested algal polysaccharide (agar, ι- or κ-carrageenan, or alginate. The isolates active on algal-polysaccharides belong to 11 genera: Cellulophaga, Maribacter, Algibacter, and Zobellia in the class Flavobacteriia (41 and Pseudoalteromonas, Vibrio, Cobetia, Shewanella, Colwellia, Marinomonas, and Paraglaceciola in the class Gammaproteobacteria (37. A major part represents likely novel species. Different proportions of bacterial phyla and classes were observed between the isolated cultivable subpopulation and the total microbial community previously identified on other brown algae. Here, Bacteroidetes and Gammaproteobacteria were found to be the most abundant and some phyla (as Planctomycetes and Cyanobacteria frequently encountered on brown algae weren’t identified. At a lower taxonomic level, twelve genera, well-known to be associated with algae (with the exception for Colwellia, were consistently found on all three A. nosodum samples. Even more interesting, 9 of the 11 above mentioned genera containing polysaccharolytic isolates were predominant in this common core. The

  1. Detection of the spectroscopic signatures of explosives and their degradation products

    Science.gov (United States)

    Florian, Vivian; Cabanzo, Andrea; Baez, Bibiana; Correa, Sandra; Irrazabal, Maik; Briano, Julio G.; Castro, Miguel E.; Hernandez-Rivera, Samuel P.

    2005-06-01

    Detection and removal of antipersonnel and antitank landmines is a great challenge and a worldwide enviromental and humanitarian problem. Sensors tuned on the spectroscopic signature of the chemicals released from mines are a potential solution. Enviromental factors (temperature, relative humidity, rainfall precipitation, wind, sun irradiation, pressure, etc.) as well as soil characteristics (water content, compaction, porosity, chemical composition, particle size distribution, topography, vegetation, etc), have a direct impact on the fate and transport of the chemicals released from landmines. Chemicals such as TNT, DNT and their degradation products, are semi-volatile, and somewhat soluble in water. Also, they may adsorb strongly to soil particles, and are susceptible to degradation by microorganisms, light, or chemical agents. Here we show an experimental procedure to quantify the effect of the above variables on the spectroscopic signature. A number of soil tanks under controlled conditions are used to study the effect of temperature, water content, relative humidity and light radiation.

  2. Molecular Identifi cation of Phenol-Degrading and Biofi lm-Forming Bacteria from Wastewater and Peat Soil

    Directory of Open Access Journals (Sweden)

    Arifah Khusnuryani

    2016-02-01

    Full Text Available Phenol is hazardous aromatic pollutant which needs to be treated to reduce its hazardous effects.Bioremediation using bacteria which can form biofi lm offer an alternative wastewater treatment that is cheaperand environmentally safe. Eighteen strains of phenol-degrading and biofi lm-forming bacteria were isolatedfrom peat soil, also hospital and textile wastewater. Screening for phenol degradation ability of isolates wereperformed using Folin-ciocalteau reagent, while for biofi lm formation ability were performed using microtiterplate and crystal violet dye. Based on the ability to degrade phenol and to form biofi lm, four isolates (HP3,DOK135, DL120, andATA6 were choosen as phenol-degrading bacteria as well as biofi lm-forming bacteria.Based on phenotypic and genotypic characterization, isolate HP3 was highly similar to Rhodococcus equi strainDSM20307T, while DOK135 was highly similar to Enterobacter mori strain R18-2.The results also suggested thatDL120 and ATA6 could be classifi ed to the genus of Micrococcus and Bacillus respectively

  3. Characterization of marine bacteria and the activity of their enzyme systems involved in degradation of the algal storage glucan laminarin

    NARCIS (Netherlands)

    Alderkamp, A-C.; van Rijssel, M.; Bolhuis, H.

    2007-01-01

    The algal storage glucan laminarin is one of the most abundant carbon sources for marine prokaryotes. Its degradation was investigated in bacteria isolated during and after a spring phytoplankton bloom in the coastal North Sea. On average, 13% of prokaryotes detected by epifluorescence counts were a

  4. Cultivation-dependent and cultivation-independent characterisation of hydrocarbon-degrading bacteria in Guaymas Basin sediments

    Directory of Open Access Journals (Sweden)

    Tony eGutierrez

    2015-07-01

    Full Text Available Marine hydrocarbon-degrading bacteria perform a fundamental role in the biodegradation of crude oil and its petrochemical derivatives in coastal and open ocean environments. However, there is a paucity of knowledge on the diversity and function of these organisms in deep-sea sediment. Here we used stable-isotope probing (SIP, a valuable tool to link the phylogeny and function of targeted microbial groups, to investigate polycyclic aromatic hydrocarbon (PAH-degrading bacteria under aerobic conditions in sediments from Guaymas Basin with uniformly labeled [13C]phenanthrene. The dominant sequences in clone libraries constructed from 13C-enriched bacterial DNA (from phenanthrene enrichments were identified to belong to the genus Cycloclasticus. We used quantitative PCR primers targeting the 16S rRNA gene of the SIP-identified Cycloclasticus to determine their abundance in sediment incubations amended with unlabeled phenanthrene and showed substantial increases in gene abundance during the experiments. We also isolated a strain, BG-2, representing the SIP-identified Cycloclasticus sequence (99.9% 16S rRNA gene sequence identity, and used this strain to provide direct evidence of phenanthrene degradation and mineralization. In addition, we isolated Halomonas, Thalassospira and Lutibacterium spp. with demonstrable phenanthrene-degrading capacity from Guaymas Basin sediment. This study demonstrates the value of coupling SIP with cultivation methods to identify and expand on the known diversity of PAH-degrading bacteria in the deep-sea.

  5. Cultivation-dependent and cultivation-independent characterization of hydrocarbon-degrading bacteria in Guaymas Basin sediments.

    Science.gov (United States)

    Gutierrez, Tony; Biddle, Jennifer F; Teske, Andreas; Aitken, Michael D

    2015-01-01

    Marine hydrocarbon-degrading bacteria perform a fundamental role in the biodegradation of crude oil and its petrochemical derivatives in coastal and open ocean environments. However, there is a paucity of knowledge on the diversity and function of these organisms in deep-sea sediment. Here we used stable-isotope probing (SIP), a valuable tool to link the phylogeny and function of targeted microbial groups, to investigate polycyclic aromatic hydrocarbon (PAH)-degrading bacteria under aerobic conditions in sediments from Guaymas Basin with uniformly labeled [(13)C]-phenanthrene (PHE). The dominant sequences in clone libraries constructed from (13)C-enriched bacterial DNA (from PHE enrichments) were identified to belong to the genus Cycloclasticus. We used quantitative PCR primers targeting the 16S rRNA gene of the SIP-identified Cycloclasticus to determine their abundance in sediment incubations amended with unlabeled PHE and showed substantial increases in gene abundance during the experiments. We also isolated a strain, BG-2, representing the SIP-identified Cycloclasticus sequence (99.9% 16S rRNA gene sequence identity), and used this strain to provide direct evidence of PHE degradation and mineralization. In addition, we isolated Halomonas, Thalassospira, and Lutibacterium sp. with demonstrable PHE-degrading capacity from Guaymas Basin sediment. This study demonstrates the value of coupling SIP with cultivation methods to identify and expand on the known diversity of PAH-degrading bacteria in the deep-sea. PMID:26217326

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

    Directory of Open Access Journals (Sweden)

    Ghabbour, N.

    2011-03-01

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

    Un total de 177 cepas de bacterias ácido lácticas (LAB fueron aisladas en las primeras etapas de la fermentación de aceitunas verdes marroquíes Picholine, incluyendo Lactobacillus plantarum (44.63%, Lactobacillus pentosus (25.99%, Lactobacillus brevis (9.61% y Pediococcus pentosaceus (19.77%. Todos los aislados fueron evaluados mediante su tolerancia a extractos de hojas de olivo y oleuropeína. La mayoría de los aislados (85,3% degradaron oleuropeína, cuando fueron evaluados usando oleuropeína o 5-Bromo-4-cloro- 3-indolil β-D-glucuronido (X-Gluc como sustrato. La capacidad de biodegradación de las cepas seleccionadas para cada especie fue confirmada mediante análisis por HPLC.

  7. Comparison of the degradation of 14C-labeled DHP and corn stalk lignins by micro- and macrofungi and bacteria

    International Nuclear Information System (INIS)

    To what extent and by which mode microfungi and bacteria from soil are able to degrade lignin have been investigated and their activity compared with those of white and brown rot Basidiomycetes. The experiments were made by means of specifically 14C-labeled DHPs prepared by polymerization of correspondingly labeled coniferyl alcohol. Also, a corn stalk material was used which was specifically labeled in the lignin part. This material was prepared by infusion of specifically labeled cinnamic acid compounds into growing maize plants. The potential of the organisms to degrade several specifically labeled phenols was determined and compared. White and brown rot fungi, as well as several microscopic fungi, were able to degrade phenolcarboxylic and cinnamic acids and even some phenolic compounds with completely alkylated phenolic hydroxl groups. They could also introduce hydroxl groups into benzoic and pi-hydroxybenzoic acids before ring cleavage. As compared to brown rot, the white rot fungi released higher amounts of CO2 from the aromatic and side chain carbons of DHP and plant lignins. Some brown rot fungi, however, had similar capacities in degrading DHP lignin as white rot fungi. They especially released more CO2 from methoxyl groups. This release was dependent upon the added carbohydrate source and could be either repressed or enhanced. Several bacteria, especially Nocardia spp. and Pseudomonas spp., were tested for their potential to degrade the labeled lignins or phenols. Most of these bacteria did not appreciably degrade lignins, although they were highly active in the metabolization of phenols. Some Nocardia spp., however, were found to have a noteworthy capacity in the degradation of lignins and phenols. Preliminary studies of the potentials of the organisms to attack labeled lignin sulfonates either in liquid or soil cultures are presented. (Refs. 100)

  8. Bacterial structure and characterization of plant growth promoting and oil degrading bacteria from the rhizospheres of mangrove plants.

    Science.gov (United States)

    do Carmo, Flávia Lima; dos Santos, Henrique Fragoso; Martins, Edir Ferreira; van Elsas, Jan Dirk; Rosado, Alexandre Soares; Peixoto, Raquel Silva

    2011-08-01

    Most oil from oceanic spills converges on coastal ecosystems, such as mangrove forests, which are threatened with worldwide disappearance. Particular bacteria that inhabit the rhizosphere of local plant species can stimulate plant development through various mechanisms; it would be advantageous if these would also be capable of degrading oil. Such bacteria may be important in the preservation or recuperation of mangrove forests impacted by oil spills. This study aimed to compare the bacterial structure, isolate and evaluate bacteria able to degrade oil and stimulate plant growth, from the rhizospheres of three mangrove plant species. These features are particularly important taking into account recent policies for mangrove bioreme-diation, implying that oil degradation as well as plant maintenance and health are key targets. Fifty-seven morphotypes were isolated from the mangrove rhizospheres on Bushneil-Haas (BH) medium supplemented with oil as the sole carbon source and tested for plant growth promotion. Of this strains, 60% potentially fixed nitrogen, 16% showed antimicrobial activity, 84% produced siderophores, 51% had the capacity to solubilize phosphate, and 33% produced the indole acetic acid hormone. Using gas chromatography, we evaluated the oil-degrading potential of ten selected strains that had different morphologies and showed Plant Growth Promoting Rhizobacteria (PGPR) features. The ten tested strains showed a promising degradation profile for at least one compound present in the oil. Among degrader strains, 46% had promising PGPR potential, having at least three of the above capacities. These strains might be used as a consortium, allowing the concomitant degradation of oil and stimulation of mangrove plant survival and maintenance. PMID:21887634

  9. Inoculation of tannin-degrading bacteria into novel hosts increases performance on tannin-rich diets.

    Science.gov (United States)

    Kohl, Kevin D; Stengel, Ashley; Dearing, M Denise

    2016-06-01

    It has been hypothesized that herbivores host tannin-degrading bacteria (TDB) to overcome the toxic challenges posed by plant tannins. While TDB have been isolated from the guts of numerous mammals, their functional significance to their hosts has never been explicitly tested. We introduced TDB into lab rats, which do not host TDB, and measured host performance on tannin-rich diets. We first isolated three species of TDB, Escherichia coli, Bacillus subtilis and Enterococcus faecalis, from the guts of the desert woodrat (Neotoma lepida), which regularly feeds on tannin-rich plants. Then, we inoculated isolated TDB, as well as full woodrat microbial communities into laboratory rats. A control group was inoculated with sterilized woodrat faeces. Recipient lab rats were fed increasing concentrations of tannic acid, and we monitored tannic acid intake, body mass and liver damage as measured by serum alanine aminotransferase activity. Lab rats given TDB as isolates or full communities exhibited increased tannic acid intake, higher maintenance of body mass and lower indicators of liver damage compared with control animals. These differences were maintained when the trial was repeated after 6 weeks of feeding on tannin-free diets. Our results are the first to demonstrate that TDB significantly increase host performance on tannin-rich diets. PMID:25753857

  10. Immobilization of degradative bacteria in polyurethane-based foams: embedding efficiency and effect on bacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Wilde, E.W. [Westinghouse Savannah River Company, Aiken, SC (United States); Radway, J.C.; Hazen, T.C.; Hermann, P. [Matrix R and D Corp., Dover, NH (United States)

    1996-09-03

    The immobilization of TCE-degrading bacterium Burkholderia cepacia was evaluated using hydrophilic polyurethane foam. The influence of several foam formulation parameters upon cell retention was examined. Surfactant type was a major determinant of retention, with a lecithin- based compound retaining more cells than pluronic or silicone based surfactants. Excessive amounts of surfactant led to increased washout of bacteria. Increasing the biomass concentration from 4.8% to 10.5% caused fewer cells to be washed out. Embedding at reduced temperature did not significantly affect retention, while the use of a silane binding agent gave inconsistent results. The optimal formulation retained all but 0.2% of total embedded cells during passage of 2 liters of water through columns containing 2 g of foam. All foam formulations tested reduced the culturability of embedded cells by several orders of magnitude. However, O{sub 2} and CO{sub 2} evolution rates of embedded cells were never less than 50% of unembedded cells. Nutrient amendments stimulated an increase in cell volume and ribosomal activity as indicated by hybridization studies using fluorescently labeled ribosomal probes. these results indicated that, although immobilized cells were nonculturable, they were metabolically active and thus could be used for biodegradation of toxic compounds.

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

    Science.gov (United States)

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

    2016-01-01

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

  12. Isolation and Identification of Pyrene-degrading Bacteria from Soils around Landfills in Shiraz and Their Growth Kinetic Assay

    Directory of Open Access Journals (Sweden)

    Farshid Kafilzadeh

    2011-12-01

    Full Text Available Background & Objectives: Pyrene is a kind of carcinogen hydrocarbon in environment and one of the top 129 pollutants as ranked by the U.S.Environmental Pretection Agency (USEPA. Today's commodious method that is considered by many researchers is the use of microorganisms to degrade these compounds from the environment. The goal of this research is separation and identification of the indigenous bacterias which are effective in decomposition of Pyrene hydrocarbon from soils around Shiraz Landfills. Isolated bacteria growth in the presence of different concentrations of the aforesaid organic pollutant was evaluated. Materials & Methods: Taking samples from Landfills were done after transportation them to the laboratory. The numbers of the bacterias were counted in a medium including Pyrene 0.6 g/l and in another medium without Pyrene. The isolated bacterias were separated by the enriched medium of hydrocarbon Pyrene and were recognized accordance with standards methods (specialty of colony, microscopic properties, fermentation of sugars and biochemical test.The kinetic growth of the separated bacterias was evaluated every 12 hours during 7 successive days. Results: It was reported that the numbers of the bacterias in the medium without Pyrene is more than those with Pyrene (cfu/g. The separated bacterias were included Bacillus spp., Pseudomonas spp., Micrococcus spp., Mycobacterium spp. These four isolated bacterias showed the best growth with Pyrene 0.6 g/l during third and fourth days. Conclusion: The separating bacterias, effecting in decomposition of PAH, make this possibility that the modern methods with more efficiency to be created for removing the carcinogen organic polluters from the environment. Moreover, the separated bacterias (relating to this research can be applied to develop the microbial population in the areas that polluted with Pyrene.

  13. Succession of hydrocarbon-degrading bacteria in the aftermath of the deepwater horizon oil spill in the gulf of Mexico.

    Science.gov (United States)

    Dubinsky, Eric A; Conrad, Mark E; Chakraborty, Romy; Bill, Markus; Borglin, Sharon E; Hollibaugh, James T; Mason, Olivia U; M Piceno, Yvette; Reid, Francine C; Stringfellow, William T; Tom, Lauren M; Hazen, Terry C; Andersen, Gary L

    2013-10-01

    The Deepwater Horizon oil spill produced large subsurface plumes of dispersed oil and gas in the Gulf of Mexico that stimulated growth of psychrophilic, hydrocarbon degrading bacteria. We tracked succession of plume bacteria before, during and after the 83-day spill to determine the microbial response and biodegradation potential throughout the incident. Dominant bacteria shifted substantially over time and were dependent on relative quantities of different hydrocarbon fractions. Unmitigated flow from the wellhead early in the spill resulted in the highest proportions of n-alkanes and cycloalkanes at depth and corresponded with dominance by Oceanospirillaceae and Pseudomonas. Once partial capture of oil and gas began 43 days into the spill, petroleum hydrocarbons decreased, the fraction of aromatic hydrocarbons increased, and Colwellia, Cycloclasticus, and Pseudoalteromonas increased in dominance. Enrichment of Methylomonas coincided with positive shifts in the δ(13)C values of methane in the plume and indicated significant methane oxidation occurred earlier than previously reported. Anomalous oxygen depressions persisted at plume depths for over six weeks after well shut-in and were likely caused by common marine heterotrophs associated with degradation of high-molecular-weight organic matter, including Methylophaga. Multiple hydrocarbon-degrading bacteria operated simultaneously throughout the spill, but their relative importance was controlled by changes in hydrocarbon supply. PMID:23937111

  14. Screening of SDS-degrading Bacteria from Carwash Wastewater and the Study of the Alkylsulfatase Enzyme Activity

    Directory of Open Access Journals (Sweden)

    Razieh Shahbazi

    2013-06-01

    Full Text Available Background and Objectives: Sodium dodecyl sulfate (SDS is one of the main surfactant components in detergents and cosmetics, used in high amounts as a detergent in products such as shampoos, car wash soap and toothpaste. Therefore, its bioremediation by suitable microorganisms is important. Alkylsulfatase is an enzyme that hydrolyses sulfate -ester bonds to give inorganic sulfate and alcohol. The purpose of this study was to isolate SDS–degrading bacteria from Tehran city car wash wastewater, study bacterial alkylsulfatase enzyme activity and identify the alkylsulfatase enzyme coding gene.Materials and Methods: Screening of SDS-degrading bacteria was carried out on basal salt medium containing SDS as the sole source of carbon. Amount of SDS degraded was assayed by methylene blue active substance (MBAS.Results and Conclusion: Identification of the sdsA gene was carried by PCR and subsequent sequencing of the 16S rDNA gene and biochemical tests identified Pseudomonas aeruginosa. This bacterium is able to degrade 84% of SDS after four days incubation. Bacteria isolated from car wash wastewater were shown to carry the sdsA gene (670bp and the alkylsulfatase enzyme specific activity expressed from this gene was determined to be 24.3 unit/mg . The results presented in this research indicate that Pseudomonas aeruginosa is a suitable candidate for SDS biodegradation.

  15. Study the Optimal Condition of Fenpropathrin Degradation by Ochrobactrum Anthropi Based on Bacteria Microscopic Image Detection Method

    Directory of Open Access Journals (Sweden)

    Ning Yang

    2013-06-01

    Full Text Available In order to study fenpropathrin degrading more accurate than turbidimetry. We proposed Live Bacteria Detection method (LBD based on high precision microscopic image processing and Support Vector Machine (SVM identification to analyze the optimal condition of fenpropathrin degradation by Ochrobactrum anthropic. The optimal fenpropathrin degradation condition measured by LBD is pH 7.0 and 34°C. On the other hand, the optimal condition measured by turbidimetry is pH 8.0 and 35°C. The correlation coefficient of fenpropathrin concentration and Ochrobactrum anthropic concentration measured by both methods in this study indicate that Ochrobactrum anthropic concentration measured by LBD shows better decreasing linear relationship with fenpropathrin degradation concentration than turbidimetry.

  16. Identification of a novel enzymatic activity from lactic acid bacteria able to degrade biogenic amines in wine.

    Science.gov (United States)

    Callejón, S; Sendra, R; Ferrer, S; Pardo, I

    2014-01-01

    The main objectives of this study were the search for enzymatic activities responsible for biogenic amine (BA) degradation in lactic acid bacteria (LAB) strains isolated from wine, their identification, and the evaluation of their applicability for reducing BAs in wine. Fifty-three percent of the 76 LAB cell extracts showed activity against a mixture of histamine, tyramine, and putrescine when analyzed in-gel. The quantification of the degrading ability for each individual amine was tested in a synthetic medium and wine. Most of the bacteria analyzed were able to degrade the three amines in both conditions. The highest percentages of degradation in wine were those of putrescine: up to 41% diminution in 1 week. Enzymes responsible for amine degradation were isolated and purified from Lactobacillus plantarum J16 and Pediococcus acidilactici CECT 5930 strains and were identified as multicopper oxidases. This is the first report of an efficient BA reduction in wine by LAB. Furthermore, the identity of the enzymes involved has been revealed. PMID:23515835

  17. Screening of phenol-degradation bacteria and study of its degradation characteristics%苯酚降解菌筛选及降解特性研究

    Institute of Scientific and Technical Information of China (English)

    李鲜珠; 沈玉冰; 马溪平; 王闻烨; 李万龙; 张宏亮; 徐成斌

    2015-01-01

    According to the characteristics that there are high content of bio-refractory organic matters in the coking wastewater and the changes of water quality and water quantity during actual production are great, the authors of this paper mainly studied the treatment of wastewater containing phenol by high efficient strains.four highly efficient degradation bacteria strains which take phenol as the sole carbon source were obtained by means of domestication, isolation and screening to the activated sludge in the aeration tank, a biological treatment device, of the water treatment plant in a coking factory.Those four highly efficient degradation bacteria strains were identified and its degradation characteristics were studied.The results show that the strain h32a2, b31B, h31A and b41a are identified as Pseudomonas sp;Phenol content was measured by brominating volumetric method.The best condition of strain degradation was determined as follows: the degradation temperature was 32℃, the pH value is 7.5 , the strain incubation time was 16h, the inoculation density was 1%, and the maximum phenol degradation rate of the strain h32 a2 reached 90.55%. We can know that the degradation effect of combined four highly efficient degradation bacteria strains is the best from the degradation characteristics of single and combined strain.The treatment of wastewater containing phenol by mixed high efficient phenol-degradation bacteria was feasible.%针对焦化废水生物难降解有机物含量高、实际生产过程中的水质和水量变化大的特点,开展了高效菌株处理含酚废水的试验研究。从某焦化厂水处理车间生物处理装置曝气池活性污泥中驯化、分离和筛选得到4株以苯酚为唯一碳源的高效降解菌,并对其进行鉴定及降解特性研究。结果表明:初步鉴定h32a2、b31B、h31A和b41a为假单胞菌属( Pseudomonas sp.);通过溴化容量法测定苯酚含量,确定了菌株的

  18. Effect of mercaptoethylamine on DNA degradation in thermophilic bacteria Bac. stearothermophilus exposed to γ-, UV-radiation or methylnitrosourea

    International Nuclear Information System (INIS)

    The effect of mercaptoethylamine (MEA) on degradation of DNA in thermophilic bacteria Bac. stear. exposed to γ-, UV-rays or methylnitrosourea (MNU) was studied. Using centrifugation on alkaline and neutral sucrose gradients, it was shown that MEA inhibits the accumulation of breaks in the DNA of Bac. stear. It also lowers the level of DNA degradation in toluene-treated cells of Bac. stear. under the action of the intrinsic nuclease, reduces the activity of the endonuclease specific for apurinic DNA, as well as that of S1-nuclease and DNase-I in vitro. The inhibition in the accumulation of DNA breaks is assumed to be due to a decrease of the endonuclease activity in the cells of thermophilic bacteria. (orig.)

  19. Microbial remediation of explosive waste.

    Science.gov (United States)

    Singh, Baljinder; Kaur, Jagdeep; Singh, Kashmir

    2012-05-01

    Explosives are synthesized globally mainly for military munitions. Nitrate esters, such as GTN and PETN, nitroaromatics like TNP and TNT and nitramines with RDX, HMX and CL20, are the main class of explosives used. Their use has resulted in severe contamination of environment and strategies are now being developed to clean these substances in an economical and eco-friendly manner. The incredible versatility inherited in microbes has rendered these explosives as a part of the biogeochemical cycle. Several microbes catalyze mineralization and/or nonspecific transformation of explosive waste either by aerobic or anaerobic processes. It is likely that ongoing genetic adaptation, with the recruitment of silent sequences into functional catabolic routes and evolution of substrate range by mutations in structural genes, will further enhance the catabolic potential of bacteria toward explosives and ultimately contribute to cleansing the environment of these toxic and recalcitrant chemicals. This review summarizes information on the biodegradation and biotransformation pathways of several important explosives. Isolation, characterization, utilization and manipulation of the major detoxifying enzymes and the molecular basis of degradation are also discussed. This may be useful in developing safer and economic microbiological methods for clean up of soil and water contaminated with such compounds. The necessity of further investigations concerning the microbial metabolism of these substances is also discussed. PMID:22497284

  20. Degradation of methyl bromide by methanotrophic bacteria in cell suspensions and soils

    Science.gov (United States)

    Oremland, R.S.; Miller, L.G.; Culbertson, C.W.; Connell, T.L.; Jahnke, L.

    1994-01-01

    Cell suspensions of Methylococcus capsulatus mineralized methyl bromide (MeBr), as evidenced by its removal from the gas phase, the quantitative recovery of Br- in the spent medium, and the production of 14CO2 from [14C]MeBr. Methyl fluoride (MeF) inhibited oxidation of methane as well as that of [14C]MeBr. The rate of MeBr consumption by cells varied inversely with the supply of methane, which suggested a competitive relationship between these two substrates. However, MeBr did not support growth of the methanotroph. In soils exposed to high levels (10,000 ppm) of MeBr, methane oxidation was completely inhibited. At this concentration, MeBr removal rates were equivalent in killed and live controls, which indicated a chemical rather than biological removal reaction. At lower concentrations (1,000 ppm) of MeBr, methanotrophs were active and MeBr consumption rates were 10-fold higher in live controls than in killed controls. Soils exposed to trace levels (10 ppm) of MeBr demonstrated complete consumption within 5 h of incubation, while controls inhibited with MeF or incubated without O2 had 50% lower removal rates. Aerobic soils oxidized [14C]MeBr to 14CO2, and MeF inhibited oxidation by 72%. Field experiments demonstrated slightly lower MeBr removal rates in chambers containing MeF than in chambers lacking MeF. Collectively, these results show that soil methanotrophic bacteria, as well as other microbes, can degrade MeBr present in the environment.

  1. Screening and Optimization of Bio surfactant Production by the Hydrocarbon-Degrading Bacteria

    International Nuclear Information System (INIS)

    Bio surfactants are amphiphilic compounds produced by microorganisms as secondary metabolite. The unique properties of bio surfactants make them possible to replace or to be added to synthetic surfactants which are mainly used in food, cosmetics and pharmaceutical industries and in environmental applications. In this study twenty hydrocarbon-degrading bacteria were screened for bio surfactant production. All of the bacterial isolates were grown in mineral salt medium (MSM) with addition of 1 % (v/v) Tapis crude oil as carbon source. The presence of bio surfactant was determined by the drop-collapse test, microplate analysis, oil spreading technique, emulsification index (%EI24) and surface tension measurement. Only one isolate, Pseudomonas aeruginosa UKMP14T, was found to be positive for all the qualitative tests and reducing the surface tension of the medium to 49.5 dynes/ with emulsification index of 25.29 %. This isolate produced bio surfactant optimally at pH 9.0 and incubation temperature of 37 degree Celsius. Furthermore, P. aeruginosa UKMP14T when grown in MSM with addition of 1 % (v/v) glycerol and 1.3 g/ L ammonium sulphate with C/N ratio 14:1 produced bio surfactant with percentage of surface tension reduction at 55 % or 30.6 dynes/ cm with %EI24 of 43 %. This percentage of surface tension reduction represents an increasing reduction in surface tension of medium by 39 % over the value before optimization. This study showed that P. aeruginosa UKMP14T has the ability to biodegrade hydrocarbon and concurrently produce bio surfactant. (author)

  2. Role of Methanogens and Other Bacteria in Degradation of Dimethyl Sulfide and Methanethiol in Anoxic Freshwater Sediments

    OpenAIRE

    Bart P. Lomans; Op den Camp, Huub J.M.; Pol, Arjan; van der Drift, Chris; Vogels, Godfried D.

    1999-01-01

    The roles of several trophic groups of organisms (methanogens and sulfate- and nitrate-reducing bacteria) in the microbial degradation of methanethiol (MT) and dimethyl sulfide (DMS) were studied in freshwater sediments. The incubation of DMS- and MT-amended slurries revealed that methanogens are the dominant DMS and MT utilizers in sulfate-poor freshwater systems. In sediment slurries, which were depleted of sulfate, 75 μmol of DMS was stoichiometrically converted into 112 μmol of methane. T...

  3. A PRELIMINARY STUDY AND FIRST REPORT ON CAFFEINE DEGRADING BACTERIA ISOLATED FROM THE SOILS OF CHITTOOR AND VELLORE

    OpenAIRE

    Sharan Siddharth; Joseph Renuka Elizabeth; A Abhiroop Anja; Nayak Rounaq S; Gambhir Vrinda; Mishra Bishwambhar; Vuppu Suneetha

    2012-01-01

    An attempt on basic study of the caffeine degrading organism and screening of potential ‘caffeinase’ producing bacteria has been studied and reported. Caffeine is present in soft drinks, coffee plants, tea leaves, and kola nuts and is used extensively in human consumption. Various health and environmental demerits makes it significant to reduce the levels of caffeine into a much less harmful compound, which can be done biologically using specific microorganisms. The enzyme responsible for caf...

  4. Microbial oil-degradation under mild hydrostatic pressure (10 MPa): which pathways are impacted in piezosensitive hydrocarbonoclastic bacteria?

    OpenAIRE

    Alberto Scoma; Marta Barbato; Emma Hernandez-Sanabria; Francesca Mapelli; Daniele Daffonchio; Sara Borin; Nico Boon

    2016-01-01

    Oil spills represent an overwhelming carbon input to the marine environment that immediately impacts the sea surface ecosystem. Microbial communities degrading the oil fraction that eventually sinks to the seafloor must also deal with hydrostatic pressure, which linearly increases with depth. Piezosensitive hydrocarbonoclastic bacteria are ideal candidates to elucidate impaired pathways following oil spills at low depth. In the present paper, we tested two strains of the ubiquitous Alcanivora...

  5. Screening of SDS-degrading bacteria from car wash wastewater and study of the alkylsulfatase enzyme activity

    OpenAIRE

    Shahbazi, Razieh; Kasra-Kermanshahi, Roha; Gharavi, Sara; Moosavi-Nejad, Zahra; Borzooee, Faezeh

    2013-01-01

    Background and Objectives Sodium dodecyl sulfate (SDS) is one of the main surfactant components in detergents and cosmetics, used in high amounts as a detergent in products such as shampoos, car wash soap and toothpaste. Therefore, its bioremediation by suitable microorganisms is important. Alkylsulfatase is an enzyme that hydrolyses sulfate -ester bonds to give inorganic sulfate and alcohol. The purpose of this study was to isolate SDS–degrading bacteria from Tehran city car wash wastewater,...

  6. Screening of SDS-degrading Bacteria from Carwash Wastewater and the Study of the Alkylsulfatase Enzyme Activity

    OpenAIRE

    Razieh Shahbazi; Roha Kasra-Kermanshahi; Sara Gharavi; Zahra Moosavi-Nejad; Faezeh Borzooee

    2013-01-01

    Background and Objectives: Sodium dodecyl sulfate (SDS) is one of the main surfactant components in detergents and cosmetics, used in high amounts as a detergent in products such as shampoos, car wash soap and toothpaste. Therefore, its bioremediation by suitable microorganisms is important. Alkylsulfatase is an enzyme that hydrolyses sulfate -ester bonds to give inorganic sulfate and alcohol. The purpose of this study was to isolate SDS–degrading bacteria from Tehran city car wash wastewater...

  7. Synergism in Degradation and Utilization of Intact Forage Cellulose, Hemicellulose, and Pectin by Three Pure Cultures of Ruminal Bacteria

    OpenAIRE

    Osborne, J. M.; Dehority, B. A.

    1989-01-01

    Pure cultures of ruminal bacteria characterized as using only a single forage polysaccharide (Fibrobacter succinogenes A3c, cellulolytic; Bacteroides ruminicola H2b, hemicellulolytic; Lachnospira multiparus D15d, pectinolytic) were inoculated separately and in all possible combinations into fermentation tubes containing orchard grass as the sole substrate. Fermentations were run to completion, and then cultures were analyzed for digestion of cellulose plus degradation and utilization of hemic...

  8. Self-bioremediation of cork-processing wastewaters by (chloro)phenol-degrading bacteria immobilised onto residual cork particles.

    Science.gov (United States)

    del Castillo, I; Hernández, P; Lafuente, A; Rodríguez-Llorente, I D; Caviedes, M A; Pajuelo, E

    2012-04-15

    Cork manufacturing is a traditional industry in Southern Europe, being the main application of this natural product in wine stoppers and insulation. Cork processing begins at boiling the raw material. As a consequence, great volumes of dark wastewaters, with elevated concentrations of chlorophenols, are generated, which must be depurated through costly physicochemical procedures before discarding them into public water courses. This work explores the potential of bacteria, isolated from cork-boiling waters storage ponds, in bioremediation of the same effluent. The bacterial population present in cork-processing wastewaters was analysed by DGGE; low bacterial biodiversity was found. Aerobic bacteria were isolated and investigated for their tolerance against phenol and two chlorophenols. The most tolerant strains were identified by sequencing 16S rDNA. The phenol-degrading capacity was investigated by determining enzyme activities of the phenol-degrading pathway. Moreover, the capacity to form biofilms was analysed in a microtitre plate assay. Finally, the capacity to form biofilms onto the surface of residual small cork particles was evaluated by acridine staining followed by epifluorescence microscopy and by SEM. A low-cost bioremediation system, using phenol-degrading bacteria immobilised onto residual cork particles (a by-product of the industry) is proposed for the remediation of this industrial effluent (self-bioremediation). PMID:22265252

  9. A PRELIMINARY STUDY AND FIRST REPORT ON CAFFEINE DEGRADING BACTERIA ISOLATED FROM THE SOILS OF CHITTOOR AND VELLORE

    Directory of Open Access Journals (Sweden)

    Sharan Siddharth

    2012-03-01

    Full Text Available An attempt on basic study of the caffeine degrading organism and screening of potential ‘caffeinase’ producing bacteria has been studied and reported. Caffeine is present in soft drinks, coffee plants, tea leaves, and kola nuts and is used extensively in human consumption. Various health and environmental demerits makes it significant to reduce the levels of caffeine into a much less harmful compound, which can be done biologically using specific microorganisms. The enzyme responsible for caffeine degradation plays a major role and hence needs to be studied for caffeinase isolation and improvement of available caffeine products. Isolation of such microorganisms and their study of extent of caffeine degradation would prove to be helpful in generating an economic and safer method of caffeine removal in food products and coffee left over which could be less harmful to human health and the environment.

  10. Culture-based Identification Of Microcystin-Degrading Bacteria In the Sandusky Bay and Maumee Bay of Lake Erie

    Science.gov (United States)

    Ormiston, A.; Mou, X.

    2012-12-01

    Harmful cyanobacteria blooms (cyanoHABs) are a serious issue that affects wildlife, human health, recreation and local economics worldwide. CyanoHABs produce cyanotoxins, such as microcystins (MCs) that lead to skin irritation, illness and liver tumors. Bacterially mediated degradation of MCs plays a key role to transform these toxic substrates to less harmful metabolites in natural environments. However, only a few Sphingomonos species have been isolated for degradation of MCs and many of which are from other habitats such as water plants. This project aims to isolate and identify bacteria that can degrade MC-LR and MC-RR, two major forms of MCs found during cyanoHABs in Lake Erie. Water samples were collected from the surface of Sandusky Bay and Maumee Bay of Lake Erie and immediately filtered through 3.0 -μm-pore-size membrane filters to obtain bacterioplankton fraction. The filtrates were amended with excessive inorganic nitrogen and phosphorus compounds and incubated in the dark for a week to purposely establish a carbon-limited condition. Afterwards, enrichment microcosms were established in flasks filled with pre-incubated bacterioplankton and single MC compounds (final concentration 10 μM). Once cell growth was confirmed by flow cytometry-based cell counting, bacterial cells in enriched microcosms were transferred onto solid surfaces, i.e., GFF filter and noble agar for colony isolation. Obtained single colonies were inoculated in defined liquid media with MCs as single carbon source. DNA was extracted from each purified isolate and analyzed by restriction fragment length polymorphism analysis (RFLP). A total of 18 different RFLP banding patterns were found, indicating MC-degrading bacteria may be heterogeneous in studied water samples. 16S rRNA genes of selected bacterial isolates were PCR amplified and sequenced for taxonomic identification. Our results demonstrated that MCs can be degraded by multiple bacterial species in Lake Erie. Future directions

  11. Biogenic amines degradation by malolactic bacteria: towards a potential application in wine

    OpenAIRE

    GiuseppeSpano; VittorioCapozzi; Alvarez, Miguel A.; DanielaFiocco; FrancescoGrieco

    2012-01-01

    Biogenic amines in wine represent a toxicological risk for the health of the consumer, with several trade implications. In this study 26 strains of Lactobacillus plantarum were analysed for their ability to degrade biogenic amines commonly found during wine fermentation. Two strains of L. plantarum were selected in reason of their ability to degrade putrescine and tyramine. The degradation was assessed in vitro, both in presence of the biogenic amines and in presence of the specific chemical ...

  12. Synergistic Degradation of Transferrin by Mutans Streptococci in Association with other Dental Plaque Bacteria

    OpenAIRE

    Homer, K A; Beighton, D.

    2011-01-01

    Streptococcus mutans strains Ingbritt and NCTC I0449 and S. sobrinus strains K1 and SL1 exhibited low, but measurable, ability to degrade human transferrin, a serum-derived glycoprotein. However, when incubated in the presence of other members of the supragingival dental plaque microflora, synergistic degradation of transferrin was observed. S. oralis and Fusobacterium nucleatum were most effective, giving rise to levels of degradation up to 3-fold above those observed with either bacterium s...

  13. Diversity of endophytic bacteria in Lolium perenne and their potential to degrade petroleum hydrocarbons and promote plant growth.

    Science.gov (United States)

    Kukla, M; Płociniczak, T; Piotrowska-Seget, Z

    2014-12-01

    The aim of this study was to assess the ability of twenty-nine endophytic bacteria isolated from the tissues of ryegrass (Lolium perenne L.) to promote plant growth and the degradation of hydrocarbon. Most of the isolates belonged to the genus Pseudomonas and showed multiple plant growth-promoting abilities. All of the bacteria that were tested exhibited the ability to produce indole-3-acetic acid and were sensitive to streptomycin. These strains were capable of phosphate solubilization (62%), cellulolytic enzyme production (62%), a capacity for motility (55%) as well as for the production of siderophore (45%), ammonium (41%) and hydrogen cyanide (38%). Only five endophytes had the emulsification ability that results from the production of biosurfactants. The 1-aminocyclopropane-1-carboxylate deaminase (ACCD) gene (acdS) was found in ten strains. These bacteria exhibited ACCD activities in the range from 1.8 to 56.6 μmol of α-ketobutyrate mg(-1)h(-1), which suggests that these strains may be able to modulate ethylene levels and enhance plant growth. The potential for hydrocarbon degradation was assessed by PCR amplification on the following genes: alkH, alkB, C23O, P450 and pah. The thirteen strains that were tested had the P450 gene but the alkH and pah genes were found only in the Rhodococcus fascians strain (L11). Four endophytic bacteria belonging to Microbacterium sp. and Rhodococcus sp. (L7, S12, S23, S25) showed positive results for the alkB gene. PMID:24954306

  14. Demonstration of Carbon Catabolite Repression in Naphthalene Degrading Soil Bacteria via Raman Spectroscopy Based Stable Isotope Probing.

    Science.gov (United States)

    Kumar B N, Vinay; Guo, Shuxia; Bocklitz, Thomas; Rösch, Petra; Popp, Jürgen

    2016-08-01

    Carbon catabolite repression (CCR) is a regulatory phenomenon occurring in both lower organisms like bacteria and higher organisms like yeast, which allows them to preferentially utilize a specific carbon source to achieve highest metabolic activity and cell growth. CCR has been intensely studied in the model organisms Escherichia coli and Bacillus subtilis by following diauxic growth curves, assays to estimate the utilization or depletion of carbon sources, enzyme assays, Western blotting and mass spectrometric analysis to monitor and quantify the involvement of specific enzymes and proteins involved in CCR. In this study, we have visualized this process in three species of naphthalene degrading soil bacteria at a single cell level via Raman spectroscopy based stable isotope probing (Raman-SIP) using a single and double labeling approach. This is achieved using a combination of (2)H and (13)C isotope labeled carbon sources like glucose, galactose, fructose, and naphthalene. Time dependent metabolic flux of (13)C and (2)H isotopes has been followed via semi quantification and 2D Raman correlation analysis. For this, the relative intensities of Raman marker bands corresponding to (2)H and (13)C incorporation in newly synthesized macromolecules like proteins and lipids have been utilized. The 2D correlation analysis of time dependent Raman spectra readily identified small sequential changes resulting from isotope incorporation. Overall, we show that Raman-SIP has the potential to be used to obtain information about regulatory processes like CCR in bacteria at a single cell level within a time span of 3 h in fast growing bacteria. We also demonstrate the potential of this approach in identifying the most efficient naphthalene degraders asserting its importance for use in bioremediation. PMID:27305464

  15. Draft Genome Sequences of Sphingobium sp. Strain TCM1 and Sphingomonas sp. Strain TDK1, Haloalkyl Phosphate Flame Retardant- and Plasticizer-Degrading Bacteria

    Science.gov (United States)

    Abe, Katsumasa; Kasai, Daisuke; Fukuda, Masao; Takahashi, Shouji

    2016-01-01

    Sphingobium sp. strain TCM1 and Sphingomonas sp. strain TDK1 are haloalkyl phosphate flame retardant- and plasticizer-degrading bacteria. We report here the draft genome sequences of these strains to provide insights into the molecular mechanism underlying their degradation ability. PMID:27417843

  16. The effect of inoculation of an indigenous bacteria on the early growth of Acacia farnesiana in a degraded area

    Directory of Open Access Journals (Sweden)

    Eliane Ceccon

    2012-03-01

    Full Text Available Restoration of native vegetation and fuelwood production are important environmental pending goals for Mexico, where years of wrong management practices resulted in ecosystemic degradation and fuelwood scarcity. In degraded areas, native rhizobial strains are often undetectable, therefore, the restoration of natural vegetation associated with an effective nodulation of the leguminous trees is mostly appropriate. Sinorhizobium americanum is a native nitrogen-fixing bacteria isolated from nodules of the native Acacia species in the region. Acacia farnesiana is a multipurpose leguminous shrub from Mexican seasonally dry tropical forests (SDTF. In this study we analyzed the effect of inoculation with S. americanum on A. farnesiana growth in a greenhouse and in a very degraded area and compared with non-inoculated seedlings. In a greenhouse, we measured the biomass dry weight of different parts of the plant, using destructive sampling after 15, 20, 30, 45 and 120 days of growth. We also calculated the relative growth rate (RGR and the resources allocation (root/shoot weight ratio and root length/root dry weight of seedlings. In a degraded area we measured the seedling length and survival and calculated the RGR. In the greenhouse and in the degraded area, the inoculation positively affected the growth of seedlings. However in the greenhouse, the inoculation did not have effect on resource allocation patterns. Therefore, the inoculation with Sinorhizobium americanum could improve the A. farnesiana growth and the re-establishment of important plant-soil interactions in degraded areas, being a recommendable technique for land restoration and the improvement of fuelwood production.

  17. Efficiency of the intestinal bacteria in the degradation of the toxic pesticide, chlorpyrifos

    OpenAIRE

    Harishankar, M. K.; C Sasikala; Ramya, M.

    2012-01-01

    Chlorpyrifos (CP) is the most commonly used pesticide throughout the world. Its widespread use in agriculture and its potential toxicity to humans from ingestion of CP contaminated food have raised concerns about its risk to health. Human intestinal microflora has the ability to degrade pesticides, but the exact mechanisms involved and the metabolite end-products formed are not well understood. The primary objective of this work was to analyse the in vitro degradation of CP by five model inte...

  18. Identification of triclosan-degrading bacteria in a triclosan enrichment culture using stable isotope probing.

    Science.gov (United States)

    Lee, Do Gyun; Cho, Kun-Ching; Chu, Kung-Hui

    2014-02-01

    Triclosan, a widely used antimicrobial agent, is an emerging contaminant in the environment. Despite its antimicrobial character, biodegradation of triclosan has been observed in pure cultures, soils and activated sludge. However, little is known about the microorganisms responsible for the degradation in mixed cultures. In this study, active triclosan degraders in a triclosan-degrading enrichment culture were identified using stable isotope probing (SIP) with universally (13)C-labeled triclosan. Eleven clones contributed from active microorganisms capable of uptake the (13)C in triclosan were identified. None of these clones were similar to known triclosan-degraders/utilizers. These clones distributed among α-, β-, or γ-Proteobacteria: one belonging to Defluvibacter (α-Proteobacteria), seven belonging to Alicycliphilus (β-Proteobacteria), and three belonging to Stenotrophomonas (γ-Proteobacteria). Successive additions of triclosan caused a significant shift in the microbial community structure of the enrichment culture, with dominant ribotypes belonging to the genera Alicycliphilus and Defluvibacter. Application of SIP has successfully identified diverse uncultivable triclosan-degrading microorganisms in an activated sludge enrichment culture. The results of this study not only contributed to our understanding of the microbial ecology of triclosan biodegradation in wastewater, but also suggested that triclosan degraders are more phylogenetically diverse than previously reported. PMID:23592331

  19. Inhibition of ethanol-producing yeast and bacteria by degradation products produced during pre-treatment of biomass.

    Science.gov (United States)

    Klinke, H B; Thomsen, A B; Ahring, B K

    2004-11-01

    An overview of the different inhibitors formed by pre-treatment of lignocellulosic materials and their inhibition of ethanol production in yeast and bacteria is given. Different high temperature physical pre-treatment methods are available to render the carbohydrates in lignocellulose accessible for ethanol fermentation. The resulting hydrolyzsates contain substances inhibitory to fermentation-depending on both the raw material (biomass) and the pre-treatment applied. An overview of the inhibitory effect on ethanol production by yeast and bacteria is presented. Apart from furans formed by sugar degradation, phenol monomers from lignin degradation are important co-factors in hydrolysate inhibition, and inhibitory effects of these aromatic compounds on different ethanol producing microorganisms is reviewed. The furans and phenols generally inhibited growth and ethanol production rate (Q(EtOH)) but not the ethanol yields (Y(EtOH)) in Saccharomyces cerevisiae. Within the same phenol functional group (aldehyde, ketone, and acid) the inhibition of volumetric ethanol productivity was found to depend on the amount of methoxyl substituents and hence hydrophobicity (log P). Many pentose-utilizing strains Escherichia coli, Pichia stipititis, and Zymomonas mobilis produce ethanol in concentrated hemicellulose liquors but detoxification by overliming is needed. Thermoanaerobacter mathranii A3M3 can grow on pentoses and produce ethanol in hydrolysate without any need for detoxification. PMID:15300416

  20. Use of bromodeoxyuridine immunocapture to identify psychrotolerant phenanthrene-degrading bacteria in phenanthrene-enriched polluted Baltic Sea sediments

    Energy Technology Data Exchange (ETDEWEB)

    Edlund, A.; Jansson, J.

    2008-05-01

    The aim of this study was to enrich and identify psychrotolerant phenanthrenedegrading bacteria from polluted Baltic Sea sediments. Polyaromatic hydrocarbon (PAH)-contaminated sediments were spiked with phenanthrene and incubated for 2 months in the presence of bromodeoxyuridine that is incorporated into the DNA of replicating cells. The bromodeoxyuridine-incorporated DNA was extracted by immunocapture and analyzed by terminal-restriction fragment length polymorphism and 16S rRNA gene cloning and sequencing to identify bacterial populations that were growing. In addition, degradation genes were quantified in the bromodeoxyuridine-incorporated DNA by real-time PCR. Phenanthrene concentrations decreased after 2 months of incubation in the phenanthrene-enriched sediments and this reduction correlated to increases in copy numbers of xylE and phnAc dioxygenase genes. Representatives of Exiguobacterium, Schewanella,Methylomonas, Pseudomonas, Bacteroides and an uncultured Deltaproteobacterium and a Gammaproteobacterium dominated the growing community in the phenanthrene spiked sediments. Isolates that were closely related to three of these bacteria (two pseudomonads and an Exiguobacterium sp.) could reduce phenanthrene concentrations in pure cultures and they all harbored phnAc dioxygenase genes. These results confirm that this combination of culture-based and molecular approaches was useful for identification of actively growing bacterial species with a high potential for phenanthrene degradation.

  1. Survey of microbial oxygenases: trichloroethylene degradation by propane-oxidizing bacteria.

    OpenAIRE

    Wackett, L P; Brusseau, G A; Householder, S R; Hanson, R S

    1989-01-01

    Microorganisms that biosynthesize broad-specificity oxygenases to initiate metabolism of linear and branched-chain alkanes, nitroalkanes, cyclic ketones, alkenoic acids, and chromenes were surveyed for the ability to biodegrade trichloroethylene (TCE). The results indicated that TCE oxidation is not a common property of broad-specificity microbial oxygenases. Bacteria that contained nitropropane dioxygenase, cyclohexanone monooxygenase, cytochrome P-450 monooxygenases, 4-methoxybenzoate monoo...

  2. Gene clusters involved in isethionate degradation by terrestrial and marine bacteria.

    KAUST Repository

    Weinitschke, Sonja

    2010-01-01

    Ubiquitous isethionate (2-hydroxyethanesulfonate) is dissimilated by diverse bacteria. Growth of Cupriavidus necator H16 with isethionate was observed, as was inducible membrane-bound isethionate dehydrogenase (IseJ) and inducible transcription of the genes predicted to encode IseJ and a transporter (IseU). Biodiversity in isethionate transport genes was observed and investigated by transcription experiments.

  3. Reconditioning of soils degraded through oil contamination using bacteria relating to thiosphaera

    International Nuclear Information System (INIS)

    Bio-preparations based on aerobic bacteria are conventionally used to decontaminate soils of oil. There is a problem of no effect in oil decomposing by using conventional bio-preparations in soils where the depth of oil penetration into the soil exceeds 60 cm in the case of oil outflow. At deep oil penetration into the soil, the efficiency of oil biodegradation with aerobic hydrocarbon oxidizing microorganisms is limited by the factor of oxygen accessibility (oxygen limit). We used Thiosphaera pantotropha as a mono-culture and together with a culture of Pseudomonas putida to solve this problem. Pseudomonas putida being aerobes decompose oil effectively at oil concentration up to 25 g of oil in 1 kg of soil and at the depth of oil penetration into the soil up to 25-30 cm. At a deeper level of soil, the activity of Pseudomonas putida falls because of oxygen limit. At the depth of 60 cm and deeper, Pseudomonas putida stop oxidize and decompose oil because of the limited oxygen accessibility. Bacteria of Thiosphaera pantotropha being elective anaerobes decompose oil both in the presence and in the absence of oxygen, and at low concentrations of oxygen insufficient for vital functions of obligate aerobic species of bacteria. Thus, bacteria of Thiosphaera pantotropha decompose hydrocarbons independently on the depth of oil penetration into the soil. Due to special features of their metabolism, bacteria of Thiosphaera pantotropha can realize their vital functions and decompose hydrocarbons at high oil concentrations in soils at which conventionally used bio-preparations can not be effective. We found out that Thiosphaera decompose sulfurous closed-ring and aromatic compounds in oil which are chemically and thermally stable and can be hardly decomposed, and possess extremely poisonous properties, as well. The use of microorganisms of Thiosphaera pantotropha allows to purify soils polluted with oil and oil products. The results obtained are applied to the cleaning of

  4. Isolation, screening, and characterization of surface-active agent-producing, oil-degrading marine bacteria of Mumbai Harbor.

    Science.gov (United States)

    Mohanram, Rajamani; Jagtap, Chandrakant; Kumar, Pradeep

    2016-04-15

    Diverse marine bacterial species predominantly found in oil-polluted seawater produce diverse surface-active agents. Surface-active agents produced by bacteria are classified into two groups based on their molecular weights, namely biosurfactants and bioemulsifiers. In this study, surface-active agent-producing, oil-degrading marine bacteria were isolated using a modified Bushnell-Haas medium with high-speed diesel as a carbon source from three oil-polluted sites of Mumbai Harbor. Surface-active agent-producing bacterial strains were screened using nine widely used methods. The nineteen bacterial strains showed positive results for more than four surface-active agent screening methods; further, these strains were characterized using biochemical and nucleic acid sequencing methods. Based on the results, the organisms belonged to the genera Acinetobacter, Alcanivorax, Bacillus, Comamonas, Chryseomicrobium, Halomonas, Marinobacter, Nesterenkonia, Pseudomonas, and Serratia. The present study confirmed the prevalence of surface-active agent-producing bacteria in the oil-polluted waters of Mumbai Harbor. PMID:26912197

  5. Anaerobic BTEX degradation in oil sands tailings ponds: Impact of labile organic carbon and sulfate-reducing bacteria.

    Science.gov (United States)

    Stasik, Sebastian; Wick, Lukas Y; Wendt-Potthoff, Katrin

    2015-11-01

    The extraction of bitumen from oil sands in Alberta (Canada) produces volumes of tailings that are pumped into large anaerobic settling-basins. Beside bitumen, tailings comprise fractions of benzene, toluene, ethylbenzene and xylenes (BTEX) that derive from the application of industrial solvents. Due to their toxicity and volatility, BTEX pose a strong concern for gas- and water-phase environments in the vicinity of the ponds. The examination of two pond profiles showed that concentrations of indigenous BTEX decreased with depth, pointing at BTEX transformation in situ. With depth, the relative contribution of ethylbenzene and xylenes to total BTEX significantly decreased, while benzene increased relatively from 44% to 69%, indicating preferential hydrocarbon degradation. To predict BTEX turnover and residence time, we determined BTEX degradation rates in tailings of different depths in a 180-days microcosm study. In addition, we evaluated the impact of labile organic substrates (e.g. acetate) generally considered to stimulate hydrocarbon degradation and the contribution of sulfate-reducing bacteria (SRB) to BTEX turnover. In all depths, BTEX concentrations significantly decreased due to microbial activity, with degradation rates ranging between 4 and 9 μg kg(-1) d(-1). BTEX biodegradation decreased linearly in correlation with initial concentrations, suggesting a concentration-dependent BTEX transformation. SRB were not significantly involved in BTEX consumption, indicating the importance of methanogenic degradation. BTEX removal decreased to 70-90% in presence of organic substrates presumptively due to an accumulation of acetate that lowered BTEX turnover due to product inhibition. In those assays SRB slightly stimulated BTEX transformation by reducing inhibitory acetate levels. PMID:26066083

  6. Identification of PCB degrading bacteria after direct isolation of DNA from contaminated soil

    Czech Academy of Sciences Publication Activity Database

    Beranová, K.; Mackova, M.; Ryšlavá, E.; Macek, Tomáš

    Chania: Technical University of Crete, 2005, s. 132. [European Bioremediation Conference /3./. Chania (GR), 04.07.2005-07.07.2005] Institutional research plan: CEZ:AV0Z40550506 Keywords : PCBs * degradation * DNA Subject RIV: DK - Soil Contamination ; De-contamination incl. Pesticides

  7. Degradative Plasmid and Heavy Metal Resistance Plasmid Naturally Coexist in Phenol and Cyanide Assimilating Bacteria

    OpenAIRE

    Bahig E.  Deeb; Abdullah D. Altalhi

    2009-01-01

    Problem statement: Heavy metals are known to be powerful inhibitors of xenobiotics biodegradation activities. Alleviation the inhibitory effect of these metals on the phenol biodegradation activities in presence of heavy metals resistant plasmid was investigated. Approach: Combination of genetic systems of degradation of xenobiotic compound and heavy metal resistance was one of the approaches to the creation of polyfunctional strains for bioremediation of s...

  8. Functionally redundant cellobiose-degrading soil bacteria respond differentially to oxygen.

    Science.gov (United States)

    Schellenberger, Stefanie; Drake, Harold L; Kolb, Steffen

    2011-09-01

    The availability of oxygen (O(2)) in aerated (i.e., water-unsaturated) soils affects the metabolic activities of aerobic and anaerobic soil prokaryotes that degrade plant-derived saccharides. Fluctuating availabilities of O(2) were imposed on agricultural soil slurries supplemented with cellobiose. Slurries were subjected to oxic conditions (48 h), followed by an anoxic period (120 h) and a final oxic period (24 h). Redox potential was stable at 500 mV during oxic periods but decreased rapidly (within 10 h) under anoxic conditions to -330 mV. The consumption of cellobiose occurred without apparent delay at all redox potentials. The metabolic activities of seven previously identified saccharolytic family-level taxa of the investigated soil were measured with newly designed quantitative PCR assays targeting the 16S rRNA. Four taxa responded to the experimental conditions. The amounts of rRNAs of Micrococcaceae and Cellulomonadaceae (Actinobacteria) increased under oxic conditions. In contrast, the RNA contents of Clostridiaceae (cluster I, Firmicutes) and two uncultured family-level-taxa, i.e., "Cellu" and "Sphingo" (both Bacteroidetes) increased under anoxic conditions. That the degradation of cellobiose was independent of the availability of O(2) and that redox potentials decreased in response to anaerobic activities indicated that the degradation of cellobiose was linked to functionally redundant cellobiose-degrading taxa capable of altering redox conditions. PMID:21742909

  9. Novel Phenanthrene-Degrading Bacteria Identified by DNA-Stable Isotope Probing.

    Directory of Open Access Journals (Sweden)

    Longfei Jiang

    Full Text Available Microorganisms responsible for the degradation of phenanthrene in a clean forest soil sample were identified by DNA-based stable isotope probing (SIP. The soil was artificially amended with either 12C- or 13C-labeled phenanthrene, and soil DNA was extracted on days 3, 6 and 9. Terminal restriction fragment length polymorphism (TRFLP results revealed that the fragments of 219- and 241-bp in HaeIII digests were distributed throughout the gradient profile at three different sampling time points, and both fragments were more dominant in the heavy fractions of the samples exposed to the 13C-labeled contaminant. 16S rRNA sequencing of the 13C-enriched fraction suggested that Acidobacterium spp. within the class Acidobacteria, and Collimonas spp. within the class Betaproteobacteria, were directly involved in the uptake and degradation of phenanthrene at different times. To our knowledge, this is the first report that the genus Collimonas has the ability to degrade PAHs. Two PAH-RHDα genes were identified in 13C-labeled DNA. However, isolation of pure cultures indicated that strains of Staphylococcus sp. PHE-3, Pseudomonas sp. PHE-1, and Pseudomonas sp. PHE-2 in the soil had high phenanthrene-degrading ability. This emphasizes the role of a culture-independent method in the functional understanding of microbial communities in situ.

  10. Effect of trichloroethylene on the competitive behavior of toluene-degrading bacteria

    NARCIS (Netherlands)

    Mars, Astrid E.; Prins, Gjalt T.; Wietzes, Pieter; Koning, Wim de; Janssen, Dick B.

    1998-01-01

    The influence of trichloroethylene (TCE) on a mixed culture of four different toluene-degrading bacterial strains (Pseudomonas putida mt-2, P. putida F1, P. putida GJ31, and Burkholderia cepacia G4) was studied with a fed-batch culture. The strains were competing for toluene, which was added at a ve

  11. Sterilization of Exopolysaccharides Produced by Deep-Sea Bacteria: Impact on Their Stability and Degradation

    OpenAIRE

    Sylvia Colliec-Jouault; Emilie Rederstorff; Corinne Sinquin; Jacqueline Ratiskol; Christophe Merceron; Claire Vinatier; Pierre Weiss; Ahmed Fatimi

    2011-01-01

    Polysaccharides are highly heat-sensitive macromolecules, so high temperature treatments are greatly destructive and cause considerable damage, such as a great decrease in both viscosity and molecular weight of the polymer. The technical feasibility of the production of exopolysaccharides by deep-sea bacteria Vibrio diabolicus and Alteromonas infernus was previously demonstrated using a bioproduct manufacturing process. The objective of this study was to determine which sterilization method, ...

  12. Isolation and identification of oil sludge degrading bacteria from production tank Number 9 Masjed Soleiman

    OpenAIRE

    Yalda Sheyni; Hossein Motamedi; Ahmadali Pourbabaei

    2014-01-01

      Introduction: “Bioremediation” is one of the most effective methods to remove petroleum contaminants. The aim of the present study is to isolate the indigenous bacteria from the waste petroleum in the Masjed Soleiman No. 9 production tank and to examine the effect of their application on the elimination of petroleum heavy chain hydrocarbons and converting them into light compounds .   Materials and methods: Two percent of petroleum sludge was inoculated to the mineral basal medium and after...

  13. Deep-sea oil plume enriches indigenous oil-degrading bacteria.

    Science.gov (United States)

    Hazen, Terry C; Dubinsky, Eric A; DeSantis, Todd Z; Andersen, Gary L; Piceno, Yvette M; Singh, Navjeet; Jansson, Janet K; Probst, Alexander; Borglin, Sharon E; Fortney, Julian L; Stringfellow, William T; Bill, Markus; Conrad, Mark E; Tom, Lauren M; Chavarria, Krystle L; Alusi, Thana R; Lamendella, Regina; Joyner, Dominique C; Spier, Chelsea; Baelum, Jacob; Auer, Manfred; Zemla, Marcin L; Chakraborty, Romy; Sonnenthal, Eric L; D'haeseleer, Patrik; Holman, Hoi-Ying N; Osman, Shariff; Lu, Zhenmei; Van Nostrand, Joy D; Deng, Ye; Zhou, Jizhong; Mason, Olivia U

    2010-10-01

    The biological effects and expected fate of the vast amount of oil in the Gulf of Mexico from the Deepwater Horizon blowout are unknown owing to the depth and magnitude of this event. Here, we report that the dispersed hydrocarbon plume stimulated deep-sea indigenous γ-Proteobacteria that are closely related to known petroleum degraders. Hydrocarbon-degrading genes coincided with the concentration of various oil contaminants. Changes in hydrocarbon composition with distance from the source and incubation experiments with environmental isolates demonstrated faster-than-expected hydrocarbon biodegradation rates at 5°C. Based on these results, the potential exists for intrinsic bioremediation of the oil plume in the deep-water column without substantial oxygen drawdown. PMID:20736401

  14. Deep-sea oil plume enriches psychrophilic oil-degrading bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Hazen, T.C.; Dubinsky, E.A.; DeSantis, T.Z.; Andersen, G.L.; Piceno, Y.M.; Singh, N.; Jansson, J.K.; Probst, A.; Borglin, S.E.; Fortney, J.L.; Stringfellow, W.T.; Bill, M.; Conrad, M.S.; Tom, L.M.; Chavarria, K.L.; Alusi, T.R.; Lamendella, R.; Joyner, D.C.; Spier, C.; Auer, M.; Zemla, M.L.; Chakraborty, R.; Sonnenthal, E.L.; D' haeseleer, P.; Holman, H.-Y. N.; Osman, S.; Lu, Z.; Van Nostrand, J.D.; Deng, Y.; Zhou, J.; Mason, O.U.

    2010-09-01

    The biological effects and expected fate of the vast amount of oil in the Gulf of Mexico from the Deepwater Horizon blowout are unknown owing to the depth and magnitude of this event. Here, we report that the dispersed hydrocarbon plume stimulated deep-sea indigenous {gamma}-Proteobacteria that are closely related to known petroleum degraders. Hydrocarbon-degrading genes coincided with the concentration of various oil contaminants. Changes in hydrocarbon composition with distance from the source and incubation experiments with environmental isolates demonstrated faster-than-expected hydrocarbon biodegradation rates at 5 C. Based on these results, the potential exists for intrinsic bioremediation of the oil plume in the deep-water column without substantial oxygen drawdown.

  15. Functionally Redundant Cellobiose-Degrading Soil Bacteria Respond Differentially to Oxygen ▿†

    OpenAIRE

    Schellenberger, Stefanie; Drake, Harold L.; Kolb, Steffen

    2011-01-01

    The availability of oxygen (O2) in aerated (i.e., water-unsaturated) soils affects the metabolic activities of aerobic and anaerobic soil prokaryotes that degrade plant-derived saccharides. Fluctuating availabilities of O2 were imposed on agricultural soil slurries supplemented with cellobiose. Slurries were subjected to oxic conditions (48 h), followed by an anoxic period (120 h) and a final oxic period (24 h). Redox potential was stable at 500 mV during oxic periods but decreased rapidly (w...

  16. Soil bacteria showing a potential of chlorpyrifos degradation and plant growth enhancement

    OpenAIRE

    Akbar, Shamsa; Sultan, Sikander

    2016-01-01

    Background Since 1960s, the organophosphate pesticide chlorpyrifos has been widely used for the purpose of pest control. However, given its persistence and toxicity towards life forms, the elimination of chlorpyrifos from contaminated sites has become an urgent issue. For this process bioremediation is the method of choice. Results Two bacterial strains, JCp4 and FCp1, exhibiting chlorpyrifos-degradation potential were isolated from pesticide contaminated agricultural fields. These isolates w...

  17. Isolation and Characterization of Polyacrylamide-Degrading Bacteria from Dewatered Sludge

    Directory of Open Access Journals (Sweden)

    Feng Yu

    2015-04-01

    Full Text Available Polyacrylamide (PAM is a water-soluble polymer that is widely used as a flocculant in sewage treatment. The accumulation of PAM affects the formation of dewatered sludge and potentially produces hazardous monomers. In the present study, the bacterial strain HI47 was isolated from dewatered sludge. This strain could metabolize PAM as its sole nutrient source and was subsequently identified as Pseudomonas putida. The efficiency of PAM degradation was 31.1% in 7 days and exceeded 45% under optimum culture condition (pH 7.2, 39 °C and 100 rpm. The addition of yeast extract and glucose improved the bacterial growth and PAM degradation. The degraded PAM samples were analyzed by gel-filtration chromatography, Fourier transform infrared and high-performance liquid chromatography. The results showed that high-molecular-weight PAM was partly cleaved to small molecular oligomer derivatives and part of the amide groups of PAM had been converted to carboxyl groups. The biodegradation did not accumulate acrylamide monomers. Based on the SDS-PAGE and N-terminal sequencing results, the PAM amide groups were converted into carboxyl groups by a PAM-induced extracellular enzyme from the aliphatic amidase family.

  18. Alkane and crude oil degrading bacteria from the petroliferous soil of India

    International Nuclear Information System (INIS)

    It has been estimated that approximately 0.5 percent of transported crude oil finds its way into seawater, largely through accidental spills and discharge of ballast and wash water from oil tankers. Some microorganisms are well known for their ability to degrade a variety of hydrocarbons present in crude oil. Oil spills at sea or on land have demonstrated the hydrocarbon-degrading potential of these organisms. Under laboratory conditions, nitrogen may be supplied in soluble form (inorganic salts of ammonia or nitrate of urea). Since most natural aquatic environments are deficient in utilizable forms of nitrogen, it is necessary to add the same exogeneously, but because of rapid dilution the added source of nitrogen does not remain effective. The need for nitrogen supplements may be overcome by appropriate choice of microbes with the genetic capacity to fix molecular nitrogen. In this paper the authors are reporting the isolation of a strain of Pseudomonas stutzeri from the petroliferous soil of India. This strain has the capacity to degrade alkane and crude oil and to fix nitrogen

  19. Identification of Rothia bacteria as gluten-degrading natural colonizers of the upper gastro-intestinal tract.

    Directory of Open Access Journals (Sweden)

    Maram Zamakhchari

    Full Text Available BACKGROUND: Gluten proteins, prominent constituents of barley, wheat and rye, cause celiac disease in genetically predisposed subjects. Gluten is notoriously difficult to digest by mammalian proteolytic enzymes and the protease-resistant domains contain multiple immunogenic epitopes. The aim of this study was to identify novel sources of gluten-digesting microbial enzymes from the upper gastro-intestinal tract with the potential to neutralize gluten epitopes. METHODOLOGY/PRINCIPAL FINDINGS: Oral microorganisms with gluten-degrading capacity were obtained by a selective plating strategy using gluten agar. Microbial speciations were carried out by 16S rDNA gene sequencing. Enzyme activities were assessed using gliadin-derived enzymatic substrates, gliadins in solution, gliadin zymography, and 33-mer α-gliadin and 26-mer γ-gliadin immunogenic peptides. Fragments of the gliadin peptides were separated by RP-HPLC and structurally characterized by mass spectrometry. Strains with high activity towards gluten were typed as Rothia mucilaginosa and Rothia aeria. Gliadins (250 µg/ml added to Rothia cell suspensions (OD(620 1.2 were degraded by 50% after ∼30 min of incubation. Importantly, the 33-mer and 26-mer immunogenic peptides were also cleaved, primarily C-terminal to Xaa-Pro-Gln (XPQ and Xaa-Pro-Tyr (XPY. The major gliadin-degrading enzymes produced by the Rothia strains were ∼70-75 kDa in size, and the enzyme expressed by Rothia aeria was active over a wide pH range (pH 3-10. CONCLUSION/SIGNIFICANCE: While the human digestive enzyme system lacks the capacity to cleave immunogenic gluten, such activities are naturally present in the oral microbial enzyme repertoire. The identified bacteria may be exploited for physiologic degradation of harmful gluten peptides.

  20. Characterization of poly(L-lactide)-degrading enzyme produced by thermophilic filamentous bacteria Laceyella sacchari LP175.

    Science.gov (United States)

    Hanphakphoom, Srisuda; Maneewong, Narisara; Sukkhum, Sukhumaporn; Tokuyama, Shinji; Kitpreechavanich, Vichien

    2014-01-01

    Eleven strains of poly(L-lactide) (PLLA)-degrading thermophilic bacteria were isolated from forest soils and selected based on clear zone formation on an emulsified PLLA agar plate at 50°C. Among the isolates, strain LP175 showed the highest PLLA-degrading ability. It was closely related to Laceyella sacchari, with 99.9% similarity based on the 16S rRNA gene sequence. The PLLA-degrading enzyme produced by the strain was purified to homogeneity by 48.1% yield and specific activity of 328 U·mg-protein-1 with a 15.3-fold purity increase. The purified enzyme was strongly active against specific substrates such as casein and gelatin and weakly active against Suc-(Ala)₃-pNA. Optimum enzyme activity was exhibited at a temperature of 60°C with thermal stability up to 50°C and a pH of 9.0 with pH stability in a range of 8.5-10.5. Molecular weight of the enzyme was approximately 28.0 kDa, as determined by gel filtration and SDS-PAGE. The inhibitors phenylmethylsulfonyl fluoride (PMSF), ethylenediaminetetraacetate (EDTA), and ethylene glycol-bis(2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA) strongly inhibited enzyme activity, but the activity was not inhibited by 1 mM 1,10-phenanthroline (1,10-phen). The N-terminal amino acid sequences had 100% homology with thermostable serine protease (thermitase) from Thermoactinomyces vulgaris. The results obtained suggest that the PLLA-degrading enzyme produced by L. sacchari strain LP175 is serine protease. PMID:24646757

  1. Bacteria capable of degrading anthracene, phenanthrene, and fluoranthene as revealed by DNA based stable-isotope probing in a forest soil.

    Science.gov (United States)

    Song, Mengke; Jiang, Longfei; Zhang, Dayi; Luo, Chunling; Wang, Yan; Yu, Zhiqiang; Yin, Hua; Zhang, Gan

    2016-05-01

    Information on microorganisms possessing the ability to metabolize different polycyclic aromatic hydrocarbons (PAHs) in complex environments helps in understanding PAHs behavior in natural environment and developing bioremediation strategies. In the present study, stable-isotope probing (SIP) was applied to investigate degraders of PAHs in a forest soil with the addition of individually (13)C-labeled phenanthrene, anthracene, and fluoranthene. Three distinct phylotypes were identified as the active phenanthrene-, anthracene- and fluoranthene-degrading bacteria. The putative phenanthrene degraders were classified as belonging to the genus Sphingomona. For anthracene, bacteria of the genus Rhodanobacter were the putative degraders, and in the microcosm amended with fluoranthene, the putative degraders were identified as belonging to the phylum Acidobacteria. Our results from DNA-SIP are the first to directly link Rhodanobacter- and Acidobacteria-related bacteria with anthracene and fluoranthene degradation, respectively. The results also illustrate the specificity and diversity of three- and four-ring PAHs degraders in forest soil, contributes to our understanding on natural PAHs biodegradation processes, and also proves the feasibility and practicality of DNA-based SIP for linking functions with identity especially uncultured microorganisms in complex microbial biota. PMID:26808242

  2. Degradative Plasmid and Heavy Metal Resistance Plasmid Naturally Coexist in Phenol and Cyanide Assimilating Bacteria

    Directory of Open Access Journals (Sweden)

    Bahig E.  Deeb

    2009-01-01

    Full Text Available Problem statement: Heavy metals are known to be powerful inhibitors of xenobiotics biodegradation activities. Alleviation the inhibitory effect of these metals on the phenol biodegradation activities in presence of heavy metals resistant plasmid was investigated. Approach: Combination of genetic systems of degradation of xenobiotic compound and heavy metal resistance was one of the approaches to the creation of polyfunctional strains for bioremediation of soil after co-contamination with organic pollutants and heavy metals. Results: A bacterial strain Pseudomonas putida PhCN (pPhCN1, pPhCN2 had been obtained. This bacterium contained two plasmids, a 120 Kb catabolic plasmid that encode for breakdown of phenol (pPhCN1 and pPhCN2 plasmid (100 Kb that code for cadmium and copper resistant. Cyanide assimilation by this bacterium was encoded by chromosomal genes. The inhibitory effect of cadmium (Cd2+ or copper (Cu2+ on the degradation of phenol and cyanide by P. putida strains PhCN and PhCN1 (contained pPhCN1 were investigated. The resistant strain PhCN showed high ability to degrade phenol and cyanide in presence of Cd2+ or Cu2+ comparing with the sensitive strain PhCN1. In addition, Cd2+ or Cu2+ was also found to exert a strong inhibitory effect on the C23O dioxygenase enzyme activity in the presence of cyanide as a nitrogen source. Conclusion: The presence of heavy metal resistance plasmid alleviated the inhibitory effect of metals on the phenol and cyanide assimilation by resistant strain.

  3. IDENTIFICATION, MOLECULAR CHARACTERIZATION AND EVALUATION OF SOME RUMINAL BACTERIA THAT CATALYZE AND DEGRADE PLANT CELLULOSIC MATERIALS

    OpenAIRE

    Ahmed A. Mansour; T.S El-Tayeb; N. E. El-Bordeny

    2014-01-01

    In the last few years there was a growing economic awareness about plant wastes and use it in compost production or in feeding of farm animals, some of these wastes are useless and cause a lot of problems in Egyptian environment. This study was designed to isolate, identify and evaluate some ruminal bacterial isolates to facilitate the in vitro degradation of certain local agro-industrial wastes (rice straw and corn stalks). Two bacterial isolates were isolated from rumen f...

  4. Effect of trichloroethylene on the competitive behavior of toluene-degrading bacteria

    OpenAIRE

    Mars, Astrid E; Prins, Gjalt T.; Wietzes, Pieter; de Koning, Wim; Janssen, Dick B.

    1998-01-01

    The influence of trichloroethylene (TCE) on a mixed culture of four different toluene-degrading bacterial strains (Pseudomonas putida mt-2, P. putida F1, P. putida GJ31, and Burkholderia cepacia G4) was studied with a fed-batch culture. The strains were competing for toluene, which was added at a very low rate (31 nmol mg of cells [dry weight](-1) h(-1)). All four strains were maintained in the mixed culture at comparable numbers when TCE was absent. After the start of the addition of TCE, th...

  5. Degradation Action of the Anaerobic Bacteria and Oxygen to the Polymer

    Institute of Scientific and Technical Information of China (English)

    LU Xiang-Guo; ZHANG Ke

    2008-01-01

    Oxygen could prohibit anaerobic bacterium in the produced water and degrade the polymer molecular chains.Aiming at problems making up aerobic polymer solution by the produced water in Daqing Oil Field, some evaluations were done on the viscosity characteristics of polymer solution and bactericide in anaerobic and aerobic environments. Reasonable aerobic concentration of the produced water was obtained. The experimental results indicate that the viscosity of polymer solution confected by the produced water in the aerobic environment is higher than that of the polymer solution confected by the produced water in the anaerobic environment, and the reasonable ments, but the sterilization effect is better in the aerobic environment.

  6. Stratification of anoxic BTEX-degrading bacteria at three petroleum-contaminated sites

    International Nuclear Information System (INIS)

    Among the most important considerations in evaluating the potential for in situ bioremediation of a hydrocarbon plume is the limitation imposed by the availability of an electron acceptor. The rates of benzene, toluene, ethylbenzene, and xylene(s) (BTEX) biodegradation, for example, have been shown in some laboratory studies to be greater with oxygen than with nitrate but other studies have shown similar hydrocarbon degradation rates under dentrifying and aerobic conditions. In most cases of bioremediation, oxygen availability is thought to limit hydrocarbon removal, even when oxygen (as H2O2 or in air) is directed to the plume. The use of nitrate is considered a viable alternative to oxygen because although degradation rates are slower, the water solubility of NO3- is much greater than that of oxygen. In addition to the availability of an electron acceptor, the stratification of microorganisms and the contaminants within aquifers, and perhaps within the plumes themselves, must also be considered. In this paper the authors demonstrate relationships among these parameters in samples from three contaminated aquifers

  7. Isolation of hydrocarbon-degrading and biosurfactant-producing bacteria and assessment their plant growth-promoting traits.

    Science.gov (United States)

    Pacwa-Płociniczak, Magdalena; Płociniczak, Tomasz; Iwan, Joanna; Żarska, Monika; Chorążewski, Mirosław; Dzida, Marzena; Piotrowska-Seget, Zofia

    2016-03-01

    Forty-two hydrocarbon-degrading bacterial strains were isolated from the soil heavily contaminated with petroleum hydrocarbons. Forty-one strains were identified based on their whole-cell fatty acid profiles using the MIDI-MIS method. Thirty-three of them belong to species Rhodococcus erythropolis, while the others to the genera Rahnella (4), Serratia (3) and Proteus (1). Isolates were screened for their ability to produce biosurfactants/bioemulsifiers. For all of them the activity of several mechanisms characteristic for plant growth-promoting bacteria was also determined. In order to investigate surface active and emulsifying abilities of isolates following methods: oil-spreading, blood agar, methylene blue agar and determination of emulsification index, were used. Among studied bacteria 12 strains (CD 112, CD 126, CD 131, CD 132, CD 135, CD 147, CD 154, CD 155, CD 158, CD 161, CD 166 and CD 167) have been chosen as promising candidates for the production of biosurfactants and/or bioemulsifiers. Among them 2 strains (R. erythropolis CD 126 and Rahnella aquatilis CD 132) had the highest potential to be used in the bioaugmentation of PH-contaminated soil. Moreover, 15 of tested strains (CD 105, CD 106, CD 108, CD 111, CD 116, CD 120, CD 124, CD 125, CD 130, CD 132, CD 134, CD 154, CD 156, CD 161 and CD 170) showed the activity of four mechanisms (ACC deaminase activity, IAA and siderophore production, phosphate solubilization) considered to be characteristic for plant growth-promoting bacteria. Two of them (R. erythropolis CD 106 and R. erythropolis CD 111) showed the highest activity of above-mentioned mechanisms and thus are considered as promising agents in microbe assisted phytoremediation. PMID:26708648

  8. The efficiency of different phenol-degrading bacteria and activated sludges in detoxification of phenolic leachates.

    Science.gov (United States)

    Kahru, A; Reiman, R; Rätsep, A

    1998-07-01

    Phenolic composition, toxicity and biodegradability of three different phenolic leachates/samples was studied. Samples A and C were the leachates from the oil-shale industry spent shale dumps at Kohtla-Järve, Estonia. Sample B was a laboratory-prepared synthetic mixture of 7 phenolic compounds mimmicking the phenolic composition of the leachate A. Toxicity of these 3 samples was analyzed using two photobacterial test (BioTox and Microtox), Daphnia test (DAPHTOXKIT F pulex) and rotifiers' test (ROTOXKIT F). All the LC50 values were in the range of 1-10%, leachate A being the most toxic. The growth and detoxifying potential (toxicity of the growth medium was measured using photobacterial tests) of 3 different phenol-utilizing bacteria and acclimated activated sludges was studied in shake-flask cultures. 30% leachate A (altogether 0.6 mM total phenolic compounds) was too toxic to rhodococci and they did not grow. Cell number of Kurthia sp. and Pseudomonas sp. in 30% leachate A increased by 2 orders of magnitude but despite of the growth of bacteria the toxicity of the leachate did not decrease even by 7 weeks of cultivation. However, if the activated sludge was used instead of pure bacterial cultures the toxicity of the 30% leachate A was eliminated already after 3 days of incubation. 30% samples B and C were detoxified by activated sludge even more rapidly, within 2 days. As the biodegradable part of samples A and B should be identical, the detoxification of leachate A compared to that of sample B was most probably inhibited by inorganic (e.g. sulphuric) compounds present in the leachate A. Also, the presence of toxic recalcitrant organic compounds in the leachate A (missed by chemical analysis) that were not readily biodegradable even by activated sludge consortium should not be excluded. PMID:9650267

  9. Molecular detection, isolation, and physiological characterization of functionally dominant phenol-degrading bacteria in activated sludge.

    Science.gov (United States)

    Watanabe, K; Teramoto, M; Futamata, H; Harayama, S

    1998-11-01

    DNA was isolated from phenol-digesting activated sludge, and partial fragments of the 16S ribosomal DNA (rDNA) and the gene encoding the largest subunit of multicomponent phenol hydroxylase (LmPH) were amplified by PCR. An analysis of the amplified fragments by temperature gradient gel electrophoresis (TGGE) demonstrated that two major 16S rDNA bands (bands R2 and R3) and two major LmPH gene bands (bands P2 and P3) appeared after the activated sludge became acclimated to phenol. The nucleotide sequences of these major bands were determined. In parallel, bacteria were isolated from the activated sludge by direct plating or by plating after enrichment either in batch cultures or in a chemostat culture. The bacteria isolated were classified into 27 distinct groups by a repetitive extragenic palindromic sequence PCR analysis. The partial nucleotide sequences of 16S rDNAs and LmPH genes of members of these 27 groups were then determined. A comparison of these nucleotide sequences with the sequences of the major TGGE bands indicated that the major bacterial populations, R2 and R3, possessed major LmPH genes P2 and P3, respectively. The dominant populations could be isolated either by direct plating or by chemostat culture enrichment but not by batch culture enrichment. One of the dominant strains (R3) which contained a novel type of LmPH (P3), was closely related to Valivorax paradoxus, and the result of a kinetic analysis of its phenol-oxygenating activity suggested that this strain was the principal phenol digester in the activated sludge. PMID:9797297

  10. High-throughput pyrosequencing analysis of bacteria relevant to cometabolic and metabolic degradation of ibuprofen in horizontal subsurface flow constructed wetlands.

    Science.gov (United States)

    Li, Yifei; Wu, Bing; Zhu, Guibing; Liu, Yu; Ng, Wun Jern; Appan, Adhityan; Tan, Soon Keat

    2016-08-15

    The potential toxicity of pharmaceutical residues including ibuprofen on the aquatic vertebrates and invertebrates has attracted growing attention to the pharmaceutical pollution control using constructed wetlands, but there lacks of an insight into the relevant microbial degradation mechanisms. This study investigated the bacteria associated with the cometabolic and metabolic degradation of ibuprofen in a horizontal subsurface flow constructed wetland system by high-throughput pyrosequencing analysis. The ibuprofen degradation dynamics, bacterial diversity and evenness, and bacterial community structure in a planted bed with Typha angustifolia and an unplanted bed (control) were compared. The results showed that the plants promoted the microbial degradation of ibuprofen, especially at the downstream zones of wetland. However, at the upstream one-third zone of wetland, the presence of plants did not significantly enhance ibuprofen degradation, probably due to the much greater contribution of cometabolic behaviors of certain non-ibuprofen-degrading microorganisms than that of the plants. By analyzing bacterial characteristics, we found that: (1) The aerobic species of family Flavobacteriaceae, family Methylococcaceae and genus Methylocystis, and the anaerobic species of family Spirochaetaceae and genus Clostridium_sensu_stricto were the most possible bacteria relevant to the cometabolic degradation of ibuprofen; (2) The family Rhodocyclaceae and the genus Ignavibacterium closely related to the plants appeared to be associated with the metabolic degradation of ibuprofen. PMID:27110975

  11. Physiological aspects of mangrove (Laguncularia racemosa) grown in microcosms with oil-degrading bacteria and oil contaminated sediment

    International Nuclear Information System (INIS)

    To assess the severity of oil spills on mangroves, diagnosis of the vegetation health is crucial. Some aspects of photosynthesis such as photochemical efficiency and leaf pigment composition together with the level of oxidative stress may constitute reliable indicators for vegetation health. To test this approach 14 month old Laguncularia racemosa were contaminated with 5 L m−2 of the marine fuel oil MF-380 and treated with an oil degrading bacterial consortium in microcosms. Contamination resulted in a 20% decrease in shoot dry weight after 128 days. Photochemical efficiency, pigment content, catalase and ascorbate peroxidase remained unchanged. Multivariate ordination of DGGE microbial community fingerprints revealed a pronounced separation between the oil contaminated and the non-contaminated samples. Further studies are necessary before physiological parameters can be recommended as indicators for plant's health in oil polluted mangroves. - Highlights: ► L. racemosa growth rate was reduced by 20% in response to a simulated oil spill of 5 L m−2 in a microcosm. ► Photochemistry was not directly affected by the oil contamination during the 128-day experiment. ► Oil contamination changed the rhizobacterial community. ► The oil degrading bacteria consortium did not affect plant growth. - Despite the need to establish methods to diagnose the health status of mangroves little is known about the impacts of petrochemicals on mangrove plants and associated rhizosphere microorganisms.

  12. Isolation and characterization of onion degrading bacteria from onion waste produced in South Buenos Aires province, Argentina.

    Science.gov (United States)

    Rinland, María Emilia; Gómez, Marisa Anahí

    2015-03-01

    Onion production in Argentina generates a significant amount of waste. Finding an effective method to recycle it is a matter of environmental concern. Among organic waste reuse techniques, anaerobic digestion could be a valuable alternative to current practices. Substrate inoculation with appropriate bacterial strains enhances the rate-limiting step (hydrolysis) of anaerobic digestion of biomass wastes. Selection of indigenous bacteria with the ability to degrade onion waste could be a good approach to find a suitable bioaugmentation or pretreatment agent. We isolated bacterial strains from onion waste in different degradation stages and from different localities. In order to characterize and select the best candidates, we analyzed the growth patterns of the isolates in a medium prepared with onion juice as the main source of nutrients and we evaluated carbon source utilization. Nine strains were selected to test their ability to grow using onion tissue and the five most remarkable ones were identified by 16S rRNA gene sequencing. Strains belonged to the genera Pseudoxanthomonas, Bacillus, Micrococcus and Pseudomonas. Two strains, Bacillus subtilis subsp. subtillis MB2-62 and Pseudomonas poae VE-74 have characteristics that make them promising candidates for bioaugmentation or pretreatment purposes. PMID:25586510

  13. Co-metabolic formation of substituted phenylacetic acids by styrene-degrading bacteria

    Directory of Open Access Journals (Sweden)

    Michel Oelschlägel

    2015-06-01

    The styrene-degrading strains Rhodococcus opacus 1CP, Pseudomonas fluorescens ST, and the novel isolates Sphingopyxis sp. Kp5.2 and Gordonia sp. CWB2 were investigated with respect to their applicability to co-metabolically produce substituted phenylacetic acids. Isolates were found to differ significantly in substrate tolerance and biotransformation yields. Especially, P. fluorescens ST was identified as a promising candidate for the production of several phenylacetic acids. The biotransformation of 4-chlorostyrene with cells of strain ST was shown to be stable over a period of more than 200 days and yielded about 38 mmolproduct gcelldryweight−1 after nearly 350 days. Moreover, 4-chloro-α-methylstyrene was predominantly converted to the (S-enantiomer of the acid with 40% enantiomeric excess.

  14. Identification of triclosan-degrading bacteria using stable isotope probing, fluorescence in situ hybridization and microautoradiography.

    Science.gov (United States)

    Lolas, Ihab Bishara; Chen, Xijuan; Bester, Kai; Nielsen, Jeppe Lund

    2012-11-01

    Triclosan is considered a ubiquitous pollutant and can be detected in a wide range of environmental samples. Triclosan removal by wastewater treatment plants has been largely attributed to biodegradation processes; however, very little is known about the micro-organisms involved. In this study, DNA-based stable isotope probing (DNA-SIP) combined with microautoradiography-fluorescence in situ hybridization (MAR-FISH) was applied to identify active triclosan degraders in an enrichment culture inoculated with activated sludge. Clone library sequences of 16S rRNA genes derived from the heavy DNA fractions of enrichment culture incubated with (13)C-labelled triclosan showed a predominant enrichment of a single bacterial clade most closely related to the betaproteobacterial genus Methylobacillus. To verify that members of the genus Methylobacillus were actively utilizing triclosan, a specific probe targeting the Methylobacillus group was designed and applied to the enrichment culture incubated with (14)C-labelled triclosan for MAR-FISH. The MAR-FISH results confirmed a positive uptake of carbon from (14)C-labelled triclosan by the Methylobacillus. The high representation of Methylobacillus in the (13)C-labelled DNA clone library and its observed utilization of (14)C-labelled triclosan by MAR-FISH reveal that these micro-organisms are the primary consumers of triclosan in the enrichment culture. The results from this study show that the combination of SIP and MAR-FISH can shed light on the networks of uncultured micro-organisms involved in degradation of organic micro-pollutants. PMID:22956759

  15. Distribution of PAHs and the PAH-degrading bacteria in the deep-sea sediments of the high-latitude Arctic Ocean

    Science.gov (United States)

    Dong, C.; Bai, X.; Sheng, H.; Jiao, L.; Zhou, H.; Shao, Z.

    2015-04-01

    Polycyclic aromatic hydrocarbons (PAHs) are common organic pollutants that can be transferred long distances and tend to accumulate in marine sediments. However, less is known regarding the distribution of PAHs and their natural bioattenuation in the open sea, especially the Arctic Ocean. In this report, sediment samples were collected at four sites from the Chukchi Plateau to the Makarov Basin in the summer of 2010. PAH compositions and total concentrations were examined with GC-MS. The concentrations of 16 EPA-priority PAHs varied from 2.0 to 41.6 ng g-1 dry weight and decreased with sediment depth and movement from the southern to the northern sites. Among the targeted PAHs, phenanthrene was relatively abundant in all sediments. The 16S rRNA gene of the total environmental DNA was analyzed with Illumina high-throughput sequencing (IHTS) to determine the diversity of bacteria involved in PAH degradation in situ. The potential degraders including Cycloclasticus, Pseudomonas, Halomonas, Pseudoalteromonas, Marinomonas, Bacillus, Dietzia, Colwellia, Acinetobacter, Alcanivorax, Salinisphaera and Shewanella, with Dietzia as the most abundant, occurred in all sediment samples. Meanwhile, enrichment with PAHs was initiated onboard and transferred to the laboratory for further enrichment and to obtain the degrading consortia. Most of the abovementioned bacteria in addition to Hahella, Oleispira, Oceanobacter and Hyphomonas occurred alternately as predominant members in the enrichment cultures from different sediments based on IHTS and PCR-DGGE analysis. To reconfirm their role in PAH degradation, 40 different bacteria were isolated and characterized, among which Cycloclasticus Pseudomonas showed the best degradation capability under low temperatures. Taken together, PAHs and PAH-degrading bacteria were widespread in the deep-sea sediments of the Arctic Ocean. We propose that bacteria of Cycloclasticus, Pseudomonas, Pseudoalteromonas, Halomonas, Marinomonas and Dietzia may

  16. Distribution of PAHs and the PAH-degrading bacteria in the deep-sea sediments of the high-latitude Arctic Ocean

    Directory of Open Access Journals (Sweden)

    C. Dong

    2014-09-01

    Full Text Available Polycyclic aromatic hydrocarbons (PAHs are persistent organic pollutants, which can be transferred to a long distance and tend to accumulation in marine sediment. However, PAHs distribution and natural bioattenuation is less known in open sea, especially in the Arctic Ocean. In this report, sediment samples were collected at four sites from the Chukchi Plateau to Makarov Basin in the summer of 2010. PAH composition and total concentrations were examined with GC-MS, we found that the concentrations of 16 EPA-priority PAHs varied from 2.0 to 41.6 ng g−1 dry weight in total and decreased with sediment depths and as well as from the southern to northern sites. Among the targeted PAHs, phenanthrene was relatively abundant in all sediments. To learn the diversity of bacteria involved in PAHs degradation in situ, the 16S rRNA gene of the total environmental DNA was analyzed with Illumina high throughput sequencing (IHTS. In all the sediments, occurred the potential degraders including Cycloclasticus, Pseudomonas, Halomonas, Pseudoalteromonas, Marinomonas, Bacillus, Dietzia, Colwellia, Acinetobacter, Alcanivorax, Salinisphaera and Shewanella, with Dietzia as the most abundant. Meanwhile on board, enrichment with PAHs was initiated and repeated transfer in laboratory to obtain the degrading consortia. Most above mentioned bacteria in addition to Hahella, Oleispira, Oceanobacter and Hyphomonas, occurred alternately as a predominant member in enrichment cultures from different sediments, as revealed with IHTS and PCR-DGGE. To reconfirm their role in PAH degradation, 40 different bacteria were isolated and characterized, among which Cycloclasticus and Pseudomonas showed the best degradation capability under low temperature. Taken together, PAHs and PAH-degrading bacteria were widespread in the deep-sea sediments of the Arctic Ocean. We propose that bacteria of Cycloclasticus, Pseudomonas, Pseudoalteromonas, Halomonas, Marinomonas and Dietzia may play the

  17. Distribution of PAHs and the PAH-degrading bacteria in the deep-sea sediments of the high-latitude Arctic Ocean

    Science.gov (United States)

    Dong, C.; Bai, X.; Sheng, H.; Jiao, L.; Zhou, H.; Shao, Z.

    2014-09-01

    Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants, which can be transferred to a long distance and tend to accumulation in marine sediment. However, PAHs distribution and natural bioattenuation is less known in open sea, especially in the Arctic Ocean. In this report, sediment samples were collected at four sites from the Chukchi Plateau to Makarov Basin in the summer of 2010. PAH composition and total concentrations were examined with GC-MS, we found that the concentrations of 16 EPA-priority PAHs varied from 2.0 to 41.6 ng g-1 dry weight in total and decreased with sediment depths and as well as from the southern to northern sites. Among the targeted PAHs, phenanthrene was relatively abundant in all sediments. To learn the diversity of bacteria involved in PAHs degradation in situ, the 16S rRNA gene of the total environmental DNA was analyzed with Illumina high throughput sequencing (IHTS). In all the sediments, occurred the potential degraders including Cycloclasticus, Pseudomonas, Halomonas, Pseudoalteromonas, Marinomonas, Bacillus, Dietzia, Colwellia, Acinetobacter, Alcanivorax, Salinisphaera and Shewanella, with Dietzia as the most abundant. Meanwhile on board, enrichment with PAHs was initiated and repeated transfer in laboratory to obtain the degrading consortia. Most above mentioned bacteria in addition to Hahella, Oleispira, Oceanobacter and Hyphomonas, occurred alternately as a predominant member in enrichment cultures from different sediments, as revealed with IHTS and PCR-DGGE. To reconfirm their role in PAH degradation, 40 different bacteria were isolated and characterized, among which Cycloclasticus and Pseudomonas showed the best degradation capability under low temperature. Taken together, PAHs and PAH-degrading bacteria were widespread in the deep-sea sediments of the Arctic Ocean. We propose that bacteria of Cycloclasticus, Pseudomonas, Pseudoalteromonas, Halomonas, Marinomonas and Dietzia may play the most important role

  18. Isolation and identification of α-Endosulfan degrading bacteria from insect microflora

    Directory of Open Access Journals (Sweden)

    Özlem Gür Özdal

    2016-04-01

    Full Text Available Increasing of industrialization and population has resulted in the accumulation of a wide variety of chemicals. Especially, widespread use of synthetic and toxic chemicals have led to an effort to improve new technologies to reduce or eliminate these contaminants from the environment. Chemical methods that used for the treatment of toxic materials are expensive, time-consuming and difficult, especially in extensive agricultural areas. Furthermore these methods led to formation of new chemical pollutants. Recent years, one promising alternative treatment method is to use of microorganisms for the biodegradation of these toxic chemicals. This method is effective, minimally hazardous, economical, versatile and environment friendly. In this study, we thought that microflora of insecticide resistant insects may be a potential reservoir for the isolation of new bacteria that can be used for the biodegradation of insecticides. In this research work, totally 24 bacterial isolates capable of biodegradation α-endosulsan were isolated from the body microflora of insects belong to Orthoptera, Dermaptera, Mantodea and Hymenoptera orders. Based on the some morphological, physiological and biochemical characteristics and fatty acid profiles they were identified as Stenotrophomonas, Pseudomonas, Acinetobacter, Bacillus, Brevibacillus, Flavimonas and Rhodococcus. As a result, these isolates can be used for the treatment of α-endosulfan residues at different environments.

  19. Sterilization of Exopolysaccharides Produced by Deep-Sea Bacteria: Impact on Their Stability and Degradation

    Directory of Open Access Journals (Sweden)

    Sylvia Colliec-Jouault

    2011-02-01

    Full Text Available Polysaccharides are highly heat-sensitive macromolecules, so high temperature treatments are greatly destructive and cause considerable damage, such as a great decrease in both viscosity and molecular weight of the polymer. The technical feasibility of the production of exopolysaccharides by deep-sea bacteria Vibrio diabolicus and Alteromonas infernus was previously demonstrated using a bioproduct manufacturing process. The objective of this study was to determine which sterilization method, other than heat sterilization, was the most appropriate for these marine exopolysaccharides and was in accordance with bioprocess engineering requirements. Chemical sterilization using low-temperature ethylene oxide and a mixture of ionized gases (plasmas was compared to the sterilization methods using gamma and beta radiations. The changes to both the physical and chemical properties of the sterilized exopolysaccharides were analyzed. The use of ethylene oxide can be recommended for the sterilization of polysaccharides as a weak effect on both rheological and structural properties was observed. This low-temperature gas sterilizing process is very efficient, giving a good Sterility Assurance Level (SAL, and is also well suited to large-scale compound manufacturing in the pharmaceutical industry.

  20. Adhesion and production of degrading enzymes by bacteria isolated from biofilms in raw milk cooling tanks

    Directory of Open Access Journals (Sweden)

    Juliana Flach

    2014-09-01

    Full Text Available Biofilms in milk cooling tanks compromise product quality even on farms. Due to the lack of studies of this topic, this study evaluated the microbiological conditions of raw milk cooling tanks on farms and characterized the microorganisms isolated from these tanks. Samples were wiped off with sterile swabs from seven milk cooling tanks in three different points in each tank. Mesophiles and psychrotrophic counts were performed in all samples. The isolation of Pseudomonas spp., Bacillus cereus and atypical colonies formed on selective media were also performed, totalizing 297 isolates. All isolates were tested for protease and lipase production and biofilm formation. Of the total isolates, 62.9% produced protease, 55.9% produced lipase, and 50.2% produced biofilm. The most widespread genus inside the milk cooling tank was Pseudomonas since it was not possible to associate this contamination with a single sampling point in the equipment. High counts of microorganisms were found in some cooling tanks, indicating poor cleaning of the equipment and providing strong evidences of microbial biofilm presence. Moreover, it is worth mentioning the milk potential contamination with both microbial cells and their degrading enzymes, which compromises milk quality.

  1. Identification and characterization of carbosulfan degrading bacteria from different areas of Punjab

    International Nuclear Information System (INIS)

    Eight different strains (BCTL 202-209) having specific ability to degrade and utilize carbofuran insecticide for their growth, were isolated from different areas of Punjab. The optical pH and temperature of the selected bacterial isolates were 6.9-7 and 30-40 deg. C, respectively. The growth patterns of these isolates were studied on LB and M9 + glucose (50 mg/100 ml), M9 + carbosulfan (5 mg/l) medium. Typical growths patterns were observed in LB medium, where as prolong log or stationary phase were noted in M9 medium. On the basis of biochemical analysis these strains were belong to genus Planococcus, Marinococcus, Sporosarcina, Bacillus, Enterococcus and Micrococcus. All these strains showed resistance against heavy metal like Hg/sup +2/, Co/sup +2/, Cr/sup +3/ and Cu/sup +2/. The antibiotic sensitivity of the isolates were also checked against nine different antibiotics. These isolates showed resistance against ampicillin, furazolidone, and fusidic acid. These isolated can be employed in the microbe based bioremediation of insecticide contaminated soil and waste water. (author)

  2. Synchrotron FT-FIR spectroscopy of nitro-derivatives vapors: New spectroscopic signatures of explosive taggants and degradation products

    Science.gov (United States)

    Cuisset, Arnaud; Gruet, Sébastien; Pirali, Olivier; Chamaillé, Thierry; Mouret, Gaël

    2014-11-01

    We report on the first successful rovibrational study of gas phase mononitrotoluene and dinitrotoluene in the TeraHertz/Far-Infrared (THz/FIR) spectral domain. Using the AILES beamline of the synchrotron SOLEIL and a Fourier Transform spectrometer connected to multipass cells, the low-energy vibrational cross-sections of the different isomers of mononitrotoluene have been measured and compared to calculated spectra with the density functional theory including the anharmonic contribution. The active FIR modes of 2,4 and 2,6 dinitrotoluene have been assigned to the vibrational bands measured by Fourier Transform FIR spectroscopy of the gas-phase molecular cloud produced in an evaporating/recondensating system. This study highlights the selectivity of gas phase THz/FIR spectroscopy allowing an unambiguous recognition and discrimination of nitro-aromatic compounds used as explosive taggants.

  3. Xylan utilization in human gut commensal bacteria is orchestrated by unique modular organization of polysaccharide-degrading enzymes

    KAUST Repository

    Zhang, Meiling

    2014-08-18

    Enzymes that degrade dietary and host-derived glycans represent the most abundant functional activities encoded by genes unique to the human gut microbiome. However, the biochemical activities of a vast majority of the glycan-degrading enzymes are poorly understood. Here, we use transcriptome sequencing to understand the diversity of genes expressed by the human gut bacteria Bacteroides intestinalis and Bacteroides ovatus grown in monoculture with the abundant dietary polysaccharide xylan. The most highly induced carbohydrate active genes encode a unique glycoside hydrolase (GH) family 10 endoxylanase (BiXyn10A or BACINT-04215 and BACOVA-04390) that is highly conserved in the Bacteroidetes xylan utilization system. The BiXyn10A modular architecture consists of a GH10 catalytic module disrupted by a 250 amino acid sequence of unknown function. Biochemical analysis of BiXyn10A demonstrated that such insertion sequences encode a new family of carbohydrate-binding modules (CBMs) that binds to xy-lose- configured oligosaccharide/polysaccharide ligands, the substrate of the BiXyn10A enzymatic activity. The crystal structures of CBM1 from BiXyn10A (1.8 Å), a cocomplex of BiXyn10A CBM1 with xylohexaose (1.14 Å), and the CBM fromits homolog in the Prevotella bryantii B 14 Xyn10C (1.68 Å) reveal an unanticipated mode for ligand binding. Aminimal enzyme mix, composed of the gene products of four of the most highly up-regulated genes during growth on wheat arabinoxylan, depolymerizes the polysaccharide into its component sugars. The combined biochemical and biophysical studies presented here provide a framework for understanding fiber metabolism by an important group within the commensal bacterial population known to influence human health.

  4. A Survey of Deepwater Horizon (DWH Oil-Degrading Bacteria from the Eastern Oyster Biome and its Surrounding Environment

    Directory of Open Access Journals (Sweden)

    Jesse eThomas

    2014-04-01

    Full Text Available The Deepwater Horizon (DWH accident led to the release of an estimated 794,936,474 liters of crude oil into the northern Gulf of Mexico over an 85 day period in 2010, resulting in the contamination of the Gulf of Mexico waters, sediments, permeable beach sands, coastal wetlands and marine life. This study examines the potential response of the Eastern oyster’s microbiome to hydrocarbon contamination and compares it with the bacterial community responses observed from the overlaying water column and the oyster bed sediments. For this purpose, microcosms seeded with DWH crude oil were established and inoculated separately with oyster tissue (OT, mantle fluid (MF, overlaying water column (WC and sediments (S collected from Apalachicola Bay, FL. Shifts in the microbial community structure in the amended microcosms was monitored over a 3-month period using automated ribosomal intergenic spacer region analysis (ARISA, which showed that the microbiome of the oyster tissue and mantle fluid were more similar to the sediment communities than those present in the overlaying water column. This pattern remained largely consistent, regardless of the concentration of crude oil or the enrichment period. Additionally, 72 oil-degrading bacteria were isolated from the microcosms containing OT, MF, WC and S and identified using 16S ribosomal RNA (rRNA gene sequencing and compared by principal component analysis (PCA which clearly showed that the water column isolates were different to those identified from the sediment. Conversely, the oyster tissue and mantle fluid isolates clustered together; a strong indication that the oyster microbiome is uniquely structured relative to its surrounding environment. When selected isolates from the OT, MF, WC and S were assessed for their oil-degrading potential, we found that the DWH oil was biodegraded between 12%-42%, under the existing conditions.

  5. Microbial oil-degradation under mild hydrostatic pressure (10 MPa): which pathways are impacted in piezosensitive hydrocarbonoclastic bacteria?

    Science.gov (United States)

    Scoma, Alberto; Barbato, Marta; Hernandez-Sanabria, Emma; Mapelli, Francesca; Daffonchio, Daniele; Borin, Sara; Boon, Nico

    2016-01-01

    Oil spills represent an overwhelming carbon input to the marine environment that immediately impacts the sea surface ecosystem. Microbial communities degrading the oil fraction that eventually sinks to the seafloor must also deal with hydrostatic pressure, which linearly increases with depth. Piezosensitive hydrocarbonoclastic bacteria are ideal candidates to elucidate impaired pathways following oil spills at low depth. In the present paper, we tested two strains of the ubiquitous Alcanivorax genus, namely A. jadensis KS_339 and A. dieselolei KS_293, which is known to rapidly grow after oil spills. Strains were subjected to atmospheric and mild pressure (0.1, 5 and 10 MPa, corresponding to a depth of 0, 500 and 1000 m, respectively) providing n-dodecane as sole carbon source. Pressures equal to 5 and 10 MPa significantly lowered growth yields of both strains. However, in strain KS_293 grown at 10 MPa CO2 production per cell was not affected, cell integrity was preserved and PO4(3-) uptake increased. Analysis of its transcriptome revealed that 95% of its genes were downregulated. Increased transcription involved protein synthesis, energy generation and respiration pathways. Interplay between these factors may play a key role in shaping the structure of microbial communities developed after oil spills at low depth and limit their bioremediation potential. PMID:27020120

  6. Microbial oil-degradation under mild hydrostatic pressure (10 MPa): which pathways are impacted in piezosensitive hydrocarbonoclastic bacteria?

    Science.gov (United States)

    Scoma, Alberto; Barbato, Marta; Hernandez-Sanabria, Emma; Mapelli, Francesca; Daffonchio, Daniele; Borin, Sara; Boon, Nico

    2016-03-01

    Oil spills represent an overwhelming carbon input to the marine environment that immediately impacts the sea surface ecosystem. Microbial communities degrading the oil fraction that eventually sinks to the seafloor must also deal with hydrostatic pressure, which linearly increases with depth. Piezosensitive hydrocarbonoclastic bacteria are ideal candidates to elucidate impaired pathways following oil spills at low depth. In the present paper, we tested two strains of the ubiquitous Alcanivorax genus, namely A. jadensis KS_339 and A. dieselolei KS_293, which is known to rapidly grow after oil spills. Strains were subjected to atmospheric and mild pressure (0.1, 5 and 10 MPa, corresponding to a depth of 0, 500 and 1000 m, respectively) providing n-dodecane as sole carbon source. Pressures equal to 5 and 10 MPa significantly lowered growth yields of both strains. However, in strain KS_293 grown at 10 MPa CO2 production per cell was not affected, cell integrity was preserved and PO43‑ uptake increased. Analysis of its transcriptome revealed that 95% of its genes were downregulated. Increased transcription involved protein synthesis, energy generation and respiration pathways. Interplay between these factors may play a key role in shaping the structure of microbial communities developed after oil spills at low depth and limit their bioremediation potential.

  7. Microbial oil-degradation under mild hydrostatic pressure (10 MPa): which pathways are impacted in piezosensitive hydrocarbonoclastic bacteria?

    KAUST Repository

    Scoma, Alberto

    2016-03-29

    Oil spills represent an overwhelming carbon input to the marine environment that immediately impacts the sea surface ecosystem. Microbial communities degrading the oil fraction that eventually sinks to the seafloor must also deal with hydrostatic pressure, which linearly increases with depth. Piezosensitive hydrocarbonoclastic bacteria are ideal candidates to elucidate impaired pathways following oil spills at low depth. In the present paper, we tested two strains of the ubiquitous Alcanivorax genus, namely A. jadensis KS_339 and A. dieselolei KS_293, which is known to rapidly grow after oil spills. Strains were subjected to atmospheric and mild pressure (0.1, 5 and 10 MPa, corresponding to a depth of 0, 500 and 1000 m, respectively) providing n-dodecane as sole carbon source. Pressures equal to 5 and 10 MPa significantly lowered growth yields of both strains. However, in strain KS_293 grown at 10 MPa CO2 production per cell was not affected, cell integrity was preserved and PO43− uptake increased. Analysis of its transcriptome revealed that 95% of its genes were downregulated. Increased transcription involved protein synthesis, energy generation and respiration pathways. Interplay between these factors may play a key role in shaping the structure of microbial communities developed after oil spills at low depth and limit their bioremediation potential.

  8. Microbial oil-degradation under mild hydrostatic pressure (10 MPa): which pathways are impacted in piezosensitive hydrocarbonoclastic bacteria?

    Science.gov (United States)

    Scoma, Alberto; Barbato, Marta; Hernandez-Sanabria, Emma; Mapelli, Francesca; Daffonchio, Daniele; Borin, Sara; Boon, Nico

    2016-01-01

    Oil spills represent an overwhelming carbon input to the marine environment that immediately impacts the sea surface ecosystem. Microbial communities degrading the oil fraction that eventually sinks to the seafloor must also deal with hydrostatic pressure, which linearly increases with depth. Piezosensitive hydrocarbonoclastic bacteria are ideal candidates to elucidate impaired pathways following oil spills at low depth. In the present paper, we tested two strains of the ubiquitous Alcanivorax genus, namely A. jadensis KS_339 and A. dieselolei KS_293, which is known to rapidly grow after oil spills. Strains were subjected to atmospheric and mild pressure (0.1, 5 and 10 MPa, corresponding to a depth of 0, 500 and 1000 m, respectively) providing n-dodecane as sole carbon source. Pressures equal to 5 and 10 MPa significantly lowered growth yields of both strains. However, in strain KS_293 grown at 10 MPa CO2 production per cell was not affected, cell integrity was preserved and PO43− uptake increased. Analysis of its transcriptome revealed that 95% of its genes were downregulated. Increased transcription involved protein synthesis, energy generation and respiration pathways. Interplay between these factors may play a key role in shaping the structure of microbial communities developed after oil spills at low depth and limit their bioremediation potential. PMID:27020120

  9. Microcalorimetric investigation of the toxic action of pyrene on the growth of PAH-degrading bacteria Acinetobacter junii.

    Science.gov (United States)

    Chen, Yanjiao; Yao, Jun; Chen, Ke; Wang, Fei; Zhou, Yong; Chen, Huilun; Gai, Nan; Ceccanti, Brunello; Trebse, Polonca; Zaray, Gyula; Choi, Martin M F; Wong, Ming Hong

    2010-01-01

    A multi-channel thermal activity microcalorimeter was used to determine the pyrene-induced toxic effect on two polycyclic aromatic hydrocarbon (PAH)-degrading bacteria Acinetobacter junii (A. junii) and Bacillus subtilis (B. subtilis). Power-time curves were analyzed and calorimetric parameters including growth rate constant (k), half inhibitory concentration (IC50) and total thermal effect (QT) were obtained. A. junii and B. subtilis were completely inhibited when the concentration of pyrene reached 400 and 160 microg mL(-1), respectively. The relationships between the calorimetric parameters and concentration of pyrene were studied. The growth rate of A. junii decreased with the increase in pyrene concentration at 50-200 microg mL(-1). The growth of biomass for A. junii at various concentrations of pyrene was determined. The count of A. junii after 8 day's incubation reached maximum irrespective of the initial pyrene concentrations ranging from 50 to 200 microg mL(-1) and the smallest stimulative action of pyrene was at 200 microg mL(-1). The variations of biomass during the growth of A. junii were consistent with the microcalorimetric data, indicating that microcalorimetry can be an effective technique to investigate the effect of pyrene on microorganisms. PMID:20390914

  10. Enzymes for Degradation of Energetic Materials and Demilitarization of Explosives Stockpiles - SERDP Annual (Interim) Report, 12/98

    Energy Technology Data Exchange (ETDEWEB)

    Shah, M.M.

    1999-01-18

    The current stockpile of energetic materials requiring disposal contains about half a million tons. Through 2001, over 2.1 million tons are expected to pass through the stockpile for disposal. Safe and environmentally acceptable methods for disposing of these materials are needed. This project is developing safe, economical, and environmentally sound processes using biocatalyst (enzymes) to degrade energetic materials and to convert them into economically valuable products. Alternative methods for destroying these materials are hazardous, environmentally unacceptable, and expensive. These methods include burning, detonation, land and sea burial, treatment at high temperature and pressure, and treatment with harsh chemicals. Enzyme treatment operates at room temperature and atmospheric pressure in a water solution.

  11. Exploring the Role of Nanoscale Zero Valent Iron and Bacteria on the Degradation of a Multi-component Chlorinated Solvent at the Field Scale

    Science.gov (United States)

    Kocur, C. M.; Lomheim, L.; Boparai, H.; Chowdhury, A. I.; Weber, K.; Austrins, L. M.; Sleep, B. E.; Edwards, E.; O'Carroll, D. M.

    2013-12-01

    Nanoscale zero valent iron (nZVI) has advanced as a technology for the remediation of priority source zone contaminants in response to early laboratory studies that showed rapid rates of compound degradation. The challenges associated with the delivery of nZVI particles (eg. rapid aggregation and settling) were partially resolved with the addition of a polyelectrolyte polymers, like Carboxymethyl cellulose, that significantly improves the colloidal stability of particles allowing for more controlled injection and transport in the subsurface. Following nZVI application and abiotic contaminant degradation nZVI oxidizes and yields reducing conditions. These reducing conditions are ideal for many dechlorinating bacteria. Given this, application of nZVI for abiotic contaminant degradation followed by bioremediation has become an area of active research interest. In this study nZVI was injected into a contaminated sandy subsurface area. Concentrations of a range of chlorinated compounds, including chlorinated ethenes, ethanes, and methanes were monitored in detail following nano-particle injection in order to access short term abiotic degradation. Monitoring continued over a 2 year period to evaluate the long term effects of nZVI injection on the bacterial communities and the biotic degradation of targeted chlorinated compounds. The study focusses on the degradation and evolution of intermediate compounds from reaction with targeted contaminant compounds along the nZVI flow path. Bacterial populations were quantified before injection to confirm that beneficial chloride reducing bacteria were present on site. The microbiological response to the injection of nZVI was studied and the performance of bacteria along the nZVI flow path and outside the nZVI affected area will be compared.

  12. Diversity and abundance of n-alkane degrading bacteria in the near surface soils of a Chinese onshore oil and gas field

    Directory of Open Access Journals (Sweden)

    K. Zhao

    2012-10-01

    Full Text Available Alkane degrading bacteria have long been used as an important biological indicator for oil and gas prospecting, but their ecological characteristics in hydrocarbon microseep habitats are still poorly understood. In this study, the diversity and abundance of n-alkane degrading bacterial community in the near surface soils of a Chinese onshore oil and gas field were investigated using molecular techniques. Terminal restriction fragment length polymorphism (T-RFLP analyses in combination with cloning and sequencing of alkB genes revealed that trace amount of volatile hydrocarbons migrated from oil and gas reservoirs caused a shift of the n-alkane degrading bacterial community from Gram-positive bacteria (Mycobacterium and Rhodococcus to Gram-negative genotypes (Alcanivorax and Acinetobacter. Real-time PCR results furthermore showed that the abundance of alkB genes increased substantially in the surface soils underlying oil and gas reservoirs even though only low or undetectable concentrations of hydrocarbons were measured in these soils due to efficient microbial degradation. Our findings broadened the knowledge on the ecological characteristics of alkane degrading community in hydrocarbon microseeps and may provide a new approach for microbial prospecting for oil and gas (MPOG.

  13. Diversity and abundance of n-alkane degrading bacteria in the near surface soils of a Chinese onshore oil and gas field

    Science.gov (United States)

    Xu, K.; Tang, Y.; Ren, C.; Zhao, K.; Sun, Y.

    2012-10-01

    Alkane degrading bacteria have long been used as an important biological indicator for oil and gas prospecting, but their ecological characteristics in hydrocarbon microseep habitats are still poorly understood. In this study, the diversity and abundance of n-alkane degrading bacterial community in the near surface soils of a Chinese onshore oil and gas field were investigated using molecular techniques. Terminal restriction fragment length polymorphism (T-RFLP) analyses in combination with cloning and sequencing of alkB genes revealed that trace amount of volatile hydrocarbons migrated from oil and gas reservoirs caused a shift of the n-alkane degrading bacterial community from Gram-positive bacteria (Mycobacterium and Rhodococcus) to Gram-negative genotypes (Alcanivorax and Acinetobacter). Real-time PCR results furthermore showed that the abundance of alkB genes increased substantially in the surface soils underlying oil and gas reservoirs even though only low or undetectable concentrations of hydrocarbons were measured in these soils due to efficient microbial degradation. Our findings broadened the knowledge on the ecological characteristics of alkane degrading community in hydrocarbon microseeps and may provide a new approach for microbial prospecting for oil and gas (MPOG).

  14. Oil-removal enhancement in media with keratinous or chitinous wastes by hydrocarbon-degrading bacteria isolated from oil-polluted soils.

    Science.gov (United States)

    Cervantes-González, E; Rojas-Avelizapa, N G; Cruz-Camarillo, R; García-Mena, J; Rojas-Avelizapa, L I

    2008-02-01

    The aim of this work was to isolate oil-degrading bacteria that use chitin or keratin as carbon sources from oil contaminated soils; and additionally to study if oil removal by these bacteria is enhanced when a chitinous or a keratinous waste is added to the culture media. To isolate the above-mentioned bacteria, 12 soil samples were collected close to an oil-well. Such soils showed unsuitable nutrients content, but their counts of heterotrophic bacteria ranged within 10(5)-10(8) CFU g(-1) soil, of which 0.1-77% corresponded to oil hydrocarbon-degrading ones. By sampling on plates, 109 oil-degrading bacterial isolates were obtained. Their keratinase and chitinase activities were then screened by plate assays and spectrophotometric methods, resulting in 13 isolates that were used to integrate two mixed cultures, one keratinolytic and the other chitinolytic. These mixed cultures were grown in media with oil, or oil supplemented with chicken-feathers or shrimp wastes. The oil-hydrocarbon removal was measured by gas chromatography. Results showed that keratinolytic bacteria were better enzyme producers than the chitinolytic ones, and that oil removal in the presence of chicken-feathers was 3.8 times greater than with shrimp wastes, and almost twice, in comparison with oil-only added cultures. Identification of microorganisms from the mixed cultures by 16S rDNA, indicated the presence of seven different bacterial genera; Stenotrophomonas, Pseudomonas, Brevibacillus, Bacillus, Micrococcus, Lysobacter and Nocardiodes. These findings suggest that the isolated microorganisms and the chicken-feather wastes could be applied to the cleaning of oil-contaminated environments, whether in soil or water. PMID:18613616

  15. Isolation of isoprene degrading bacteria from soils, development of isoA gene probes and identification of the active isoprene-degrading soil community using DNA-stable isotope probing.

    Science.gov (United States)

    El Khawand, Myriam; Crombie, Andrew T; Johnston, Antonia; Vavlline, Dmitrii V; McAuliffe, Joseph C; Latone, Jacob A; Primak, Yuliya A; Lee, Sang-Kyu; Whited, Gregg M; McGenity, Terry J; Murrell, J Colin

    2016-09-01

    Emissions of biogenic volatile organic compounds (bVOCs), are an important element in the global carbon cycle, accounting for a significant proportion of fixed carbon. They contribute directly and indirectly to global warming and climate change and have a major effect on atmospheric chemistry. Plants emit isoprene to the atmosphere in similar quantities to emissions of methane from all sources and each accounts for approximately one third of total VOCs. Although methanotrophs, capable of growth on methane, have been intensively studied, we know little of isoprene biodegradation. Here, we report the isolation of two isoprene-degrading strains from the terrestrial environment and describe the design and testing of polymerase chain reaction (PCR) primers targeting isoA, the gene encoding the active-site component of the conserved isoprene monooxygenase, which are capable of retrieving isoA sequences from isoprene-enriched environmental samples. Stable isotope probing experiments, using biosynthesized (13) C-labelled isoprene, identified the active isoprene-degrading bacteria in soil. This study identifies novel isoprene-degrading strains using both culture-dependent and, for the first time, culture-independent methods and provides the tools and foundations for continued investigation of the biogeography and molecular ecology of isoprene-degrading bacteria. PMID:27102583

  16. Prevalence of the gene trzN and biogeographic patterns among atrazine-degrading bacteria isolated from 13 Colombian agricultural soils.

    Science.gov (United States)

    Arbeli, Ziv; Fuentes, Cilia

    2010-09-01

    The following study evaluated the diversity and biogeography of 83 new atrazine-degrading bacteria and the composition of their atrazine degradation genes. These strains were isolated from 13 agricultural soils and grouped according to rep-PCR genomic fingerprinting into 11 major clusters, which showed biogeographic patterns. Three clusters (54 strains) belonged to the genus Arthrobacter, seven clusters (28 strains) were similar to the genus Nocardioides and only one strain was a gram-negative from the genus Ancylobacter. PCR assays for the detection of the genes atzA, B, C, D, E, F and trzN conducted with each of the 83 strains revealed that 82 strains (all gram positive) possessed trzN, 74 of them possessed the combination of trzN, atzB and atzC, while only the gram-negative strain had atzA. A similar PCR assay for the two analogous genes, atzA and trzN, responsible for the first step of atrazine degradation, was performed with DNA extracted directly from the enrichment cultures and microcosms spiked with atrazine. In these assays, the gene trzN was detected in each culture, while atzA was detected in only six out of 13 soils. These results raise an interesting hypothesis on the evolutionary ecology of the two atrazine chlorohydrolase genes (i.e. atzA and trzN) and about the biogeography of atrazine-degrading bacteria. PMID:20597985

  17. 一株纤维素降解菌的筛选与鉴定%Screening and Identification of Cellulose Degradation Bacteria

    Institute of Scientific and Technical Information of China (English)

    李艳红

    2012-01-01

    12 cellulose-degrading bacterias were enriched and isolated from the leaves of the humus layer covering the soil and a high-degrading bacteria ( X10 ) was selected from these. The optimal culture conditions of the bacteria were as follows : took the culture medium containing glucose+micrlte cellulose (1:1)as carbon sources, peptone+beef( 1:1 )as nitrogen sources, pH 7.5, under 30℃, with the culture time was 40 b, the cellulose-degrading enzyme activity was up to 57.44 U.Through its 16s rRNA sequencing,the homology of bacteria and Microbacterium oxydans were 99%.The selection of cellulose-degrading bacteria provided a new source of bacteria for the egiciem production of cellulase.%从落叶覆盖的腐殖层土壤中富集、分离得到12株纤维素降解菌,从中筛选出一株高效降解菌(X10),研究其最适宜的培养条件为:配制以葡萄糖+微晶纤维隶(1:1)为碳源、以蛋白胨+牛肉膏(1:1)为氮源的培养基,pH值7.5,30℃下培养40h,测得纤维素降解酶酶活可达到67.44U。通过对其16srRNA测序鉴定,该菌与氧化微杆菌(Microbacterium oxydans)有99%的同源性。纤维素降解菌的选育可为高效生产纤维素酶提供新的菌种来源。

  18. Bioremediation of coastal areas 5 years after the Nakhodka oil spill in the Sea of Japan: isolation and characterization of hydrocarbon-degrading bacteria

    International Nuclear Information System (INIS)

    Five years after the 1997 Nakhodka oil spill in the Sea of Japan, seven bacterial strains capable of utilizing the heavy oil spilled from the Nakhodka Russian oil tanker were isolated from three coastal areas (namely Katano Seashore of Fukui Prefecture, Osawa and Atake seashores of Ishikawa Prefecture) and the Nakhodka Russian oil tanker after a 5-year bioremediation process. All bacterial strains isolated could utilize long-chain-length alkanes efficiently, but not aromatic, and all of them were able to grow well on heavy oil. Using 16S rDNA sequencing, most of the strains were affiliated to Pseudomonas aeruginosa. Comparing between the year 1997 (at the beginning of bioremediation process) and the year 2001 (after 5 years of bioremediation), there was no significant change in morphology and size of hydrocarbon-degrading bacteria during the 5-year bioremediation. Scanning and transmission electron microscopic observations revealed that a large number of hydrocarbon- degrading bacteria still existed in the sites consisting of a variety of morphological forms of bacteria, such as coccus (Streptococcus and Staphylococcus) and bacillus (Streptobacillus). On the application of bioremediation processes on the laboratory-scale, laboratory microcosm experiments (containing seawater, beach sand, and heavy oil) under aerobic condition by two different treatments (i.e., placed inside the building and outside the building) were established for bioremediation of heavy oil to investigate the significance of the role of hydrocarbon-degrading bacteria on them. There was no significant bacterial activity differentiation in the two treatments, and removal of heavy oil by hydrocarbon degrading bacteria in the outside building was slightly greater than that in the inside building. The values of pH, Eh, EC, and dissolved oxygen (DO) in two treatments indicated that the bioremediation process took place under aerobic conditions (DO: 1-6 mg/l; Eh: 12-300 mV) and neutral

  19. Cultural condition regulations for three lignin degrading bacteria%3株细菌降解木质素的条件调控研究

    Institute of Scientific and Technical Information of China (English)

    张欢; 柴立元; 朱咏华; 陈跃辉; 靳冉

    2011-01-01

    采用苯胺蓝和RB亮蓝平板对从三国吴简腐蚀斑中分离得到的3株细菌Acinetobacter sp.B-2,Pandoraea sp.B-6和Novosphingobium sp.B-7进行脱色试验,考察这3株细菌在液体培养条件下的木质素降解性能,并对其木质素降解条件的调控进行研究,初步确定这3株菌适宜的降解条件.研究结果表明:这3株细菌具有使苯胺蓝和RB亮蓝染料脱色的能力,能够产木质素降解酶;这3株细菌的木质素降解速率较快,第5天木质素的降解基本趋于稳定;菌株适宜的降解条件如下:对Acinetobacter sp.B-2,氮源为硝酸铵,氮源浓度为0.01 mol/L,培养温度为30℃,初始pH=7.0,摇床转速为120 r/min;对Pandoraea sp.B-6,氮源为磷酸氢二铵,氮源浓度为0.03 mol/L,培养温度为30℃,初始pH=7.0,摇床转速为120 r/min;对Novosphingobium sp.B-7,氮源为硝酸铵,氮源浓度为0.01 mol/L,培养温度为30℃,初始pH为5.0,摇床转速为120 r/min.在适宜的降解条件下,这3株细菌第3天的木质素降解率均可达到30%~35%.%The decolorizing reactions of three bacteria were studied through Azure-B and Remazol Brilliant Blue dye plate, which were isolated from erosive bamboo slips of Kingdom Wu, identified as Acinetobacter sp. B-2, Pandoraea sp. B-6 and Novosphingobium sp. B-7, respectively. The lignin degrading characteristics of three bacteria were investigated in the liquid medium. The effects of culture conditions on lignin degrading ability of the three bacteria were also studied, and the appropriate culture conditions were determined. The results show that three bacteria can decolorize Azure-B and Remazol Brilliant Blue dye and produce ligninolytic enzyme. Three bacteria can degrade lignin very well with a relatively high degrading rate, and the plateau of degradation is observed after 5 d incubation. Appropriate culture conditions for Acinetobacter sp. B-2 are achieved as follows: NH4NO3 nitrogen source, 0.01 mol/L of nitrogen source

  20. Hydrocarbon-Degrading Bacteria and Paraffin from Polluted Seashores 9 Years after the Nakhodka Oil Spill in the Sea of Japan

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Pollution of petroleum hydrocarbons, in particular oil spills, has attracted much attention in the past and recent decades. Oil spills influence natural microbial community, and physical and chemical properties of the affected sites. The biodegradation of hydrocarbons by microorganisms is one of the primary ways by which oil spill is eliminated from contaminated sites. One such spill was that of the Russian tanker the Nakhodka that spilled heavy oil into the Sea of Japan on January 2, 1997. The impact of the Nakhodka oil spill resulted in a viscous sticky fluid fouling the shores and affected natural ecosystems. This paper describes the weathering of hydrocarbon-degrading bacteria (genus Pseudomonas) and crystallized organic compounds from the Nakhodka oil spill-polluted seashores after nine years. The Nakhodka oil has hardened and formed crust of crystalline paraffin wax as shown by XRD analysis (0.422, 0.377, and 0.250 nm d-spacing) in association with graphite and calcite after 9years of bioremediation. Anaerobic reverse side of the oil crust contained numerous coccus typed bacteria associated with halite. The finding of hydrocarbon-degrading bacteria and paraffin wax in the oil crust may have a significant effect on the weathering processes of the Nakhodka oil spill during the 9-year bioremediation.

  1. Optimal Cultivation Time for Yeast and Lactic Acid Bacteria in Fermented Milk and Effects of Fermented Soybean Meal on Rumen Degradability Using Nylon Bag Technique

    Science.gov (United States)

    Polyorach, S.; Poungchompu, O.; Wanapat, M.; Kang, S.; Cherdthong, A.

    2016-01-01

    The objectives of this study were to determine an optimal cultivation time for populations of yeast and lactic acid bacteria (LAB) co-cultured in fermented milk and effects of soybean meal fermented milk (SBMFM) supplementation on rumen degradability in beef cattle using nylon bag technique. The study on an optimal cultivation time for yeast and LAB growth in fermented milk was determined at 0, 4, 8, 24, 48, 72, and 96 h post-cultivation. After fermenting for 4 days, an optimal cultivation time of yeast and LAB in fermented milk was selected and used for making the SBMFM product to study nylon bag technique. Two ruminal fistulated beef cattle (410±10 kg) were used to study on the effect of SBMFM supplementation (0%, 3%, and 5% of total concentrate substrate) on rumen degradability using in situ method at incubation times of 0, 2, 4, 6, 12, 24, 48, and 72 h according to a Completely randomized design. The results revealed that the highest yeast and LAB population culture in fermented milk was found at 72 h-post cultivation. From in situ study, the soluble fractions at time zero (a), potential degradability (a+b) and effective degradability of dry matter (EDDM) linearly (pcultivation and supplementation of SBMFM at 5% of total concentrate substrate could improve rumen degradability of beef cattle. However, further research on effect of SBMFM on rumen ecology and production performance in meat and milk should be conducted using in vivo both digestion and feeding trials. PMID:26954119

  2. Diversity and abundance of n-alkane-degrading bacteria in the near-surface soils of a Chinese onshore oil and gas field

    Directory of Open Access Journals (Sweden)

    K. Xu

    2013-03-01

    Full Text Available Alkane-degrading bacteria have long been used as an important biological indicator for oil and gas prospecting, but their ecological characteristics in hydrocarbon microseep habitats are still poorly understood. In this study, the diversity and abundance of n-alkane-degrading bacterial community in the near-surface soils of a Chinese onshore oil and gas field were investigated using molecular techniques. Terminal restriction fragment length polymorphism (T-RFLP analyses in combination with cloning and sequencing of alkB genes revealed that Gram-negative genotypes (Alcanivorax and Acinetobacter dominated n-alkane-degrading bacterial communities in the near-surface soils of oil and gas reservoirs, while the dominant microbial communities were Gram-positive bacteria (Mycobacterium and Rhodococcus in background soil. Real-time quantitative polymerase chain reaction (PCR results furthermore showed that the abundance of alkB genes increased substantially in the surface soils above oil and gas reservoirs even though only low or undetectable concentrations of hydrocarbons were measured in these soils. The results of this study implicate that trace amounts of volatile hydrocarbons migrate from oil and gas reservoirs, and likely result in the changes of microbial communities in the near-surface soil.

  3. Diversity and abundance of n-alkane-degrading bacteria in the near-surface soils of a Chinese onshore oil and gas field

    Science.gov (United States)

    Xu, K.; Tang, Y.; Ren, C.; Zhao, K.; Sun, Y.

    2013-03-01

    Alkane-degrading bacteria have long been used as an important biological indicator for oil and gas prospecting, but their ecological characteristics in hydrocarbon microseep habitats are still poorly understood. In this study, the diversity and abundance of n-alkane-degrading bacterial community in the near-surface soils of a Chinese onshore oil and gas field were investigated using molecular techniques. Terminal restriction fragment length polymorphism (T-RFLP) analyses in combination with cloning and sequencing of alkB genes revealed that Gram-negative genotypes (Alcanivorax and Acinetobacter) dominated n-alkane-degrading bacterial communities in the near-surface soils of oil and gas reservoirs, while the dominant microbial communities were Gram-positive bacteria (Mycobacterium and Rhodococcus) in background soil. Real-time quantitative polymerase chain reaction (PCR) results furthermore showed that the abundance of alkB genes increased substantially in the surface soils above oil and gas reservoirs even though only low or undetectable concentrations of hydrocarbons were measured in these soils. The results of this study implicate that trace amounts of volatile hydrocarbons migrate from oil and gas reservoirs, and likely result in the changes of microbial communities in the near-surface soil.

  4. Primary explosives

    Energy Technology Data Exchange (ETDEWEB)

    Matyas, Robert; Pachman, Jiri [Pardubice Univ. (Czech Republic). Faculty of Chemical Technology

    2013-06-01

    The first chapter provides background such as the basics of initiation and differences between requirements on primary explosives used in detonators and igniters. The authors then clarify the influence of physical characteristics on explosive properties, focusing on those properties required for primary explosives. Furthermore, the issue of sensitivity is discussed. All the chapters on particular groups of primary explosives are structured in the same way, including introduction, physical and chemical properties, explosive properties, preparation and documented use.

  5. Microbial degradation of N-methyl-2-pyrrolidone in surface water and bacteria responsible for the process.

    Science.gov (United States)

    Růžička, Jan; Fusková, Jana; Křížek, Karel; Měrková, Markéta; Černotová, Alena; Smělík, Michal

    2016-01-01

    Due to widespread utilization in many industrial spheres and agrochemicals, N-methyl-2-pyrrolidone (NMP) is a potential contaminant of different surface water ecosystems. Hence, investigation was made into its aerobic microbial degradability in samples of water from a river, wetland area and spring. The results showed that the compound was degradable in all water types, and that the fastest NMP removal occurred in 4 days in river water, while in the wetland and spring samples the process was relatively slow, requiring several months to complete. Key bacterial degraders were successfully isolated in all cases, and their identification proved that pseudomonads played a major role in NMP degradation in river water, while the genera Rhodococcus and Patulibacter fulfilled a similar task in the wetland sample. Regarding spring water, degrading members of the Mesorhizobium and Rhizobium genera were found. PMID:26877048

  6. Lignin distribution in waterlogged archaeological Picea abies (L.) Karst degraded by erosion bacteria

    DEFF Research Database (Denmark)

    Pedersen, Nanna Bjerregaard; Schmitt, Uwe Schmitt; Koch, Gerald;

    2014-01-01

    The lignin distribution in poles of waterlogged archaeological Picea abies (L.) Karst, which was decayed by erosion bacteria (EB) under anoxic conditions for approximately 400 years, was topochemically identified by transmission electron microscopy (TEM) and high resolution UV-microspectrophotome......The lignin distribution in poles of waterlogged archaeological Picea abies (L.) Karst, which was decayed by erosion bacteria (EB) under anoxic conditions for approximately 400 years, was topochemically identified by transmission electron microscopy (TEM) and high resolution UV...

  7. Cr-resistant rhizo- and endophytic bacteria associated with Prosopis juliflora and their potential as phytoremediation enhancing agents in metal-degraded soils

    Directory of Open Access Journals (Sweden)

    Muhammad Umar Khan

    2015-01-01

    Full Text Available Prosopis juliflora is characterized by distinct and profuse growth even in nutritionally poor soil and environmentally stressed conditions and is believed to harbor some novel heavy metal-resistant bacteria in the rhizosphere and endosphere. This study was performed to isolate and characterize Cr-resistant bacteria from the rhizosphere and endosphere of P. juliflora growing on the tannery effluent contaminated soil. A total of 5 and 21 bacterial strains were isolated from the rhizosphere and endosphere, respectively, could tolerate Cr up to 3000 mg l-1. These isolates also exhibited tolerance to other toxic heavy metals such as, Cd, Cu, Pb and Zn, and high concentration (174 g l-1 of NaCl. Moreover, most of the isolated bacterial strains showed one or more plant growth-promoting activities. The phylogenetic analysis of the 16S rRNA gene indicated a higher and wider range of population of Cr-resistant bacteria in the endosphere than rhizosphere and the predominant species included Bacillus, Staphylococcus and Aerococcus. As far as we know, this is the first report detecting rhizo- and endophytic bacterial population associated with P. juliflora growing on the tannery effluent contaminated soil. The inoculation of three isolates to ryegrass (Lolium multiflorum L. improved plant growth and heavy metal removal from the tannery effluent contaminated soil suggesting that these bacteria could enhance the establishment of the plant in contaminated soil and also improve the efficiency of phytoremediation of heavy metal-degraded soils.

  8. Genetic and phenotypic diversity of 2,4-dichlorophenoxyacetic acid (2,4-D)-degrading bacteria isolated from 2,4-D-treated field soils.

    OpenAIRE

    Ka, J O; Holben, W E; Tiedje, J M

    1994-01-01

    Forty-seven numerically dominant 2,4-dichlorophenoxyacetic acid (2,4-D)-degrading bacteria were isolated at different times from 1989 through 1992 from eight agricultural plots (3.6 by 9.1 m) which were either not treated with 2,4-D or treated with 2,4-D at three different concentrations. Isolates were obtained from the most dilute positive most-probable-number tubes inoculated with soil samples from the different plots on seven sampling dates over the 3-year period. The isolates were compare...

  9. Enhanced Biological Trace Organic Contaminant Removal: A Lab-Scale Demonstration with Bisphenol A-Degrading Bacteria Sphingobium sp. BiD32.

    Science.gov (United States)

    Zhou, Nicolette A; Gough, Heidi L

    2016-08-01

    Discharge of trace organic contaminants (TOrCs) from wastewater treatment plants (WWTPs) may contribute to deleterious effects on aquatic life. Release to the environment occurs both through WWTP effluent discharge and runoff following land applications of biosolids. This study introduces Enhanced Biological TOrC Removal (EBTCR), which involves continuous bioaugmentation of TOrC-degrading bacteria for improved removal in WWTPs. Influence of bioaugmentation on enhanced degradation was investigated in two lab-scale sequencing batch reactors (SBRs), using bisphenol A (BPA) as the TOrC. The reactors were operated with 8 cycles per day and at two solids retention times (SRTs). Once each day, the test reactor was bioaugmented with Sphingobium sp. BiD32, a documented BPA-degrading culture. After bioaugmentation, BPA degradation (including both the dissolved and sorbed fractions) was 2-4 times higher in the test reactor than in a control reactor. Improved removal persisted for >5 cycles following bioaugmentation. By the last cycle of the day, enhanced BPA removal was lost, although it returned with the next bioaugmentation. A net loss of Sphingobium sp. BiD32 was observed in the reactors, supporting the original hypothesis that continuous bioaugmentation (rather than single-dose bioaugmentation) would be required to improve TOrCs removal during wastewater treatment. This study represents a first demonstration of a biologically based approach for enhanced TOrCs removal that both reduces concentrations in wastewater effluent and prevents transfer to biosolids. PMID:27338240

  10. Field observations on the variability of crude oil impact on indigenous hydrocarbon-degrading bacteria from sub-Antarctic intertidal sediments

    International Nuclear Information System (INIS)

    Oil pollution of the oceans has been a problem ever since man began to use fossil fuels. Biodegradation by naturally occurring populations of micro-organisms is a major mechanism for the removal of petroleum from the environment. To examine the effects of crude oil-pollution on intertidal bacteria, we repeated the same contamination experiments on nine different sub-Antarctic intertidal beaches using specifically built enclosures (PVC pipe, 15 cm in inner diameter and 30 cm in height). Despite the pristine environmental conditions, significant numbers of indigenous hydrocarbon-degrading bacteria were observed in all the studied beaches. Introduction of oil into these previously oil-free environments resulted in several orders of magnitude of increase in hydrocarbon-degrading micro-organisms within a few days in some of the studied sites but has no obvious effects on two others. The physical environment of the bacterial assemblage seems to play a major role in the biodegradation capacities. After 3 months of contamination, both remaining oil concentrations and biodegradation indexes differ strongly between the different stations. Thus, chemical and biological parameters reveal a strong heterogeneity of biodegradation capacities between the different sites. (Author)

  11. Resistance transferance of Amorimia septentrionalis poisoning in goats by ruminal transferance fluid from goats with induced resistance by the inoculation of sodium monofluoroacetate-degrading bacteria

    Directory of Open Access Journals (Sweden)

    Layze Cilmara Alves da Silva

    2015-12-01

    Full Text Available Amorimia septentrionalis is a sodium monofluoroacetate (MFA - containing plant that causes sudden death in ruminants. The aim of this study was to determine whether the resistance to A. septentrionalis poisoning in goats conferred by the intra-ruminal inoculation with the MFA-degrading bacteria Ancylobacter dichloromethanicus and Pigmentiphaga kullae can be transferred to susceptible goats by the transfaunation of rumen content. Two groups of 8 goats and 2 goats resistant to A. septentrionalis poisoning were used. Goats in Group 1 received four daily doses of 160ml of rumen content from resistant goats and subsequently ingested 8 daily doses of 5g kg-1 of A. septentrionalis. Goats from Group 2 (control received only the plant. In Group 1, only 2 goats showed mild tachycardia and mild jugular vein engorgement on the 4th and 5th day, but they subsequently returned to normal, even with the continuation of plant administration. All control goats showed severe signs of intoxication and the plant administration was suspended between the 3rd and 7th day. So, the transfer of ruminal fluid from goats previously inoculated with MFA-degrading bacteria induces resistance to poisoning by A. septentrionalis in susceptible goats.

  12. Inhibition of ethanol-producing yeast and bacteria by degradation products produced during pre-treatment of biomass

    DEFF Research Database (Denmark)

    Klinke, H.B.; Thomsen, A.B.; Ahring, Birgitte Kiær

    2004-01-01

    An overview of the different inhibitors formed by pre-treatment of lignocellulosic materials and their inhibition of ethanol production in yeast and bacteria is given. Different high temperature physical pre-treatment methods are available to render the carbohydrates in lignocellulose accessible ...

  13. Bacterial Structure and Characterization of Plant Growth Promoting and Oil Degrading Bacteria from the Rhizospheres of Mangrove Plants

    NARCIS (Netherlands)

    do Carmo, Flavia Lima; dos Santos, Henrique Fragoso; Martins, Edir Ferreira; van Elsas, Jan Dirk; Rosado, Alexandre Soares; Peixoto, Raquel Silva

    2011-01-01

    Most oil from oceanic spills converges on coastal ecosystems, such as mangrove forests, which are threatened with worldwide disappearance. Particular bacteria that inhabit the rhizosphere of local plant species can stimulate plant development through various mechanisms; it would be advantageous if t

  14. Screening and characterization of purine nucleoside degrading lactic acid bacteria isolated from Chinese sauerkraut and evaluation of the serum uric acid lowering effect in hyperuricemic rats.

    Directory of Open Access Journals (Sweden)

    Ming Li

    Full Text Available Hyperuricemia is well known as the cause of gout. In recent years, it has also been recognized as a risk factor for arteriosclerosis, cerebrovascular and cardiovascular diseases, and nephropathy in diabetic patients. Foods high in purine compounds are more potent in exacerbating hyperuricemia. Therefore, the development of probiotics that efficiently degrade purine compounds is a promising potential therapy for the prevention of hyperuricemia. In this study, fifty-five lactic acid bacteria isolated from Chinese sauerkraut were evaluated for the ability to degrade inosine and guanosine, the two key intermediates in purine metabolism. After a preliminary screening based on HPLC, three candidate strains with the highest nucleoside degrading rates were selected for further characterization. The tested biological characteristics of candidate strains included acid tolerance, bile tolerance, anti-pathogenic bacteria activity, cell adhesion ability, resistance to antibiotics and the ability to produce hydrogen peroxide. Among the selected strains, DM9218 showed the best probiotic potential compared with other strains despite its poor bile resistance. Analysis of 16S rRNA sequences showed that DM9218 has the highest similarity (99% to Lactobacillus plantarum WCFS1. The acclimated strain DM9218-A showed better resistance to 0.3% bile salt, and its survival in gastrointestinal tract of rats was proven by PCR-DGGE. Furthermore, the effects of DM9218-A in a hyperuricemia rat model were evaluated. The level of serum uric acid in hyperuricemic rat can be efficiently reduced by the intragastric administration of DM9218-A (P<0.05. The preventive treatment of DM9218-A caused a greater reduction in serum uric acid concentration in hyperuricemic rats than the later treatment (P<0.05. Our results suggest that DM9218-A may be a promising candidate as an adjunctive treatment in patients with hyperuricemia during the onset period of disease. DM9218-A also has potential

  15. Carbon-dot-decorated TiO₂ nanotube arrays used for photo/voltage-induced organic pollutant degradation and the inactivation of bacteria.

    Science.gov (United States)

    Feng, Lingyan; Sun, Hanjun; Ren, Jinsong; Qu, Xiaogang

    2016-03-18

    Photoluminescent carbon dots (c-dots) have recently attracted growing interest as a new member of the carbon-nanomaterial family. Here, we report for the first time that c-dot-decorated TiO2 nanotube arrays (c-dot/TiNTs) exhibit highly enhanced abilities regarding photo/voltage-induced organic pollutant degradation and bacterial inactivation. By applying UV irradiation (365 nm) or an electrochemical potential over 3 V (versus Ag/AgCl), an organic dye and a herbicide were efficiently degraded. Moreover, the inactivation of Gram-positive S. aureus and Gram-negative E. coli bacteria was realized on a c-dot/TiNT film. The c-dots were able to absorb light efficiently resulting in multiple exciton generation and also a reduction in the recombination of the e(-)/h(+) pair produced in c-dot/TiNT film during photo/voltage-induced degradation. It was also possible to readily regenerate the surface using ultraviolet light irradiation, leaving the whole film structure undamaged and with high reproducibility and stability. PMID:26870882

  16. Carbon-dot-decorated TiO2 nanotube arrays used for photo/voltage-induced organic pollutant degradation and the inactivation of bacteria

    Science.gov (United States)

    Feng, Lingyan; Sun, Hanjun; Ren, Jinsong; Qu, Xiaogang

    2016-03-01

    Photoluminescent carbon dots (c-dots) have recently attracted growing interest as a new member of the carbon-nanomaterial family. Here, we report for the first time that c-dot-decorated TiO2 nanotube arrays (c-dot/TiNTs) exhibit highly enhanced abilities regarding photo/voltage-induced organic pollutant degradation and bacterial inactivation. By applying UV irradiation (365 nm) or an electrochemical potential over 3 V (versus Ag/AgCl), an organic dye and a herbicide were efficiently degraded. Moreover, the inactivation of Gram-positive S. aureus and Gram-negative E. coli bacteria was realized on a c-dot/TiNT film. The c-dots were able to absorb light efficiently resulting in multiple exciton generation and also a reduction in the recombination of the e-/h+ pair produced in c-dot/TiNT film during photo/voltage-induced degradation. It was also possible to readily regenerate the surface using ultraviolet light irradiation, leaving the whole film structure undamaged and with high reproducibility and stability.

  17. Effect of micromineral and phenylpropionic acid on performances of coccus and rod-shaped cellulolytic bacteria degrading fibre of forage

    Directory of Open Access Journals (Sweden)

    Amlius Thalib

    2000-06-01

    Full Text Available Performances of coccus and rod-shaped cellulolytic bacteria as inoculum for fermentation of fibrous substrate treated with growth or stimulator factors have been conducted by in vitro. The bacteria were firstly separated and purified based on their morphological shape and followed by identification of their gram type. The treatments as follow : control, Cu (1,0 ppm, Zn (6,0 ppm, Se (0,02 ppm, Fe (16 ppm, Co (0,02 ppm, Mn (4,0 ppm, Mo (0,002 ppm, and phenylpropionic acid (PPA (30 ppm. These factors were added into fermentation media individually (F.P/S and as mixture (Mix F.P/S. Substrates used were cellulose and rice straw. Measurements were bacterial digestion of drymatter (DMD, bacterial count, volatile fatty acids (VFA and NH3-N contents. Gram test showed that inoculum cellulolytic cocci and rods are gram-positive and gram-negative consecutively. The results of treatments showed that Cu, Zn, Co, Mo and PPA improve digestibility of cellulose and rice straw substrates by cellulolytic cocci significantly (p<0.05, and beside Mn, these factors increased the total count of cellulolytic cocci in fermentation medium significantly (p<0.05. The growth or stimulator factors increasing digestibility values of the substrates by cellulolytic rods significantly (p<0.05 were Cu, Zn, Se, Fe, Co, Mn and Mo (except Mn for rice straw substrate. Only 4 elements of the growth and stimulator factors increasing the total count of cellulolytic rods during fermentation of cellulose and rice straw substrates significantly (p<0.05 that is Zn, Co, Mn and Mo. Digestibility of cellulose by cocci is higher than by rods (34.65% vs 29.87%, however, the digestibility of rice straw by both bacteria did not show difference. Digestibility of both cellulose and rice straw substrates was improved by cocci and rods combination and improved further when treated with Mix F.P/S. Parameters of fermentation media ecosystem measured (i.e. total count of bacteria, VFA and NH3-N were

  18. 氯嘧磺隆降解菌降解效果研究%Research on Degradation Effect of Chlorimuron ethyl Degradable Bacteria

    Institute of Scientific and Technical Information of China (English)

    王彦杰; 洪秀杰; 宋伟英; 王冬梅

    2012-01-01

    近年来除草剂在土壤中持续积累,对后茬敏感作物造成严重药害,导致作物减产甚至绝产,氯嘧磺隆就是其中一种广谱、超高效和残留期较长的磺酰脲类除草剂。该试验通过氯嘧磺隆降解菌的筛选并作用于受氯嘧磺隆药害的萌芽水稻种子,利用测定筛选出的氯嘧磺隆降解菌对氯嘧碘隆的降解作用来研究其对氟嘧磺隆的降解作用效果。结果表明:所筛选的氯嘧磺隆降解菌对氯嘧磺隆有一定的降解作用。在同一菌不同浓度下,氯嘧磺隆5μg·kg-1时降解效果最好。在同一氯嘧磺隆水平下,降解菌稀释倍数为100倍时降解效果最佳。%In recent years the herbicide is accumulated continually in the soil, bringing serious chemical damage to the stubble sensitive crop, which resuhed in the reduction of crop yield,even non-production. The chlorimuron ethyl is one of broad-spectrum,highly effective and sulphur ureide class weed killers. Through screening of the chlorimuron ethyl degradable bactieria and using it to affect the paddy rice seeds which were damaged by weed killer,the degeneration effect of the bactieria on the chlorimuron was studied. The result showed that the degeneration effect was the best when the dosage of chlorimuron ethyl was 5 μg·kg-1 , the best degradation effect was obtained when the bactieria was diluted 100 times at the same level of the chlorimuron ethyl dosage.

  19. Occurrence of diverse alkane hydroxylase alkB genes in indigenous oil-degrading bacteria of Baltic Sea surface water.

    Science.gov (United States)

    Viggor, Signe; Jõesaar, Merike; Vedler, Eve; Kiiker, Riinu; Pärnpuu, Liis; Heinaru, Ain

    2015-12-30

    Formation of specific oil degrading bacterial communities in diesel fuel, crude oil, heptane and hexadecane supplemented microcosms of the Baltic Sea surface water samples was revealed. The 475 sequences from constructed alkane hydroxylase alkB gene clone libraries were grouped into 30 OPFs. The two largest groups were most similar to Pedobacter sp. (245 from 475) and Limnobacter sp. (112 from 475) alkB gene sequences. From 56 alkane-degrading bacterial strains 41 belonged to the Pseudomonas spp. and 8 to the Rhodococcus spp. having redundant alkB genes. Together 68 alkB gene sequences were identified. These genes grouped into 20 OPFs, half of them being specific only to the isolated strains. Altogether 543 diverse alkB genes were characterized in the brackish Baltic Sea water; some of them representing novel lineages having very low sequence identities with corresponding genes of the reference strains. PMID:26541986

  20. Adaptation mechanisms of bacteria during the degradation of polychlorinated biphenyls in the presence of natural and synthetic terpenes as potential degradation inducers

    Energy Technology Data Exchange (ETDEWEB)

    Zoradova-Murinova, Slavomira; Dudasova, Hana; Lukacova, Lucia; Certik, Milan; Dercova, Katarina [Slovak Univ. of Technology, Bratislava (Slovakia). Inst. of Biotechnology and Food Science; Silharova, Katarina; Vrana, Branislav [Water Research Institute, Bratislava (Slovakia)

    2012-06-15

    In this study, we examined the effect of polychlorinated biphenyls (PCBs) in the presence of natural and synthetic terpenes and biphenyl on biomass production, lipid accumulation, and membrane adaptation mechanisms of two PCB-degrading bacterial strains Pseudomonas stutzeri and Burkholderia xenovorans LB400. According to the results obtained, it could be concluded that natural terpenes, mainly those contained in ivy leaves and pine needles, decreased adaptation responses induced by PCBs in these strains. The adaptation processes under investigation included growth inhibition, lipid accumulation, composition of fatty acids, cis/trans isomerization, and membrane saturation. Growth inhibition effect decreased upon addition of these natural compounds to the medium. The amount of unsaturated fatty acids that can lead to elevated membrane fluidity increased in both strains after the addition of the two natural terpene sources. The cells adaptation changes were more prominent in the presence of carvone, limonene, and biphenyl than in the presence of natural terpenes, as indicated by growth inhibition, lipid accumulation, and cis/trans isomerization. Addition of biphenyl and carvone simultaneously with PCBs increased the trans/cis ratio of fatty acids in membrane fractions probably as a result of fluidizing effects of PCBs. This stimulation is more pronounced in the presence of PCBs as a sole carbon source. This suggests that PCBs alone have a stronger effect on bacterial membrane adaptation mechanisms than when added together with biphenyl or natural or synthetic terpenes. (orig.)

  1. Degradation properties of various macromolecules of cultivable psychrophilic bacteria from the deep-sea water of the South Pacific Gyre.

    Science.gov (United States)

    Zhang, Li; Wang, Yan; Liang, Jing; Song, Qinghao; Zhang, Xiao-Hua

    2016-09-01

    The deep-sea water of the South Pacific Gyre (SPG, 20°S-45°S) is a cold and ultra-oligotrophic environment that is the source of cold-adapted enzymes. However, the characteristic features of psychrophilic enzymes derived from culturable microbes in the SPG remained largely unknown. In this study, the degradation properties of 174 cultures from the deep water of the SPG were used to determine the diversity of cold-adapted enzymes. Thus, the abilities to degrade polysaccharides, proteins, lipids, and DNA at 4, 16, and 28 °C were investigated. Most of the isolates showed one or more extracellular enzyme activities, including amylase, chitinase, cellulase, lipase, lecithinase, caseinase, gelatinase, and DNase at 4, 16, and 28 °C. Moreover, nearly 85.6 % of the isolates produced cold-adapted enzymes at 4 °C. The psychrophilic enzyme-producing isolates distributed primarily in Alteromonas and Pseudoalteromonas genera of the Gammaproteobacteria. Pseudoalteromonas degraded 9 types of macromolecules but not cellulose, Alteromonas secreted 8 enzymes except for cellulase and chitinase. Interestingly, the enzymatic activities of Gammaproteobacteria isolates at 4 °C were higher than those observed at 16 or 28 °C. In addition, we cloned and expressed a gene encoding an α-amylase (Amy2235) from Luteimonas abyssi XH031(T), and examined the properties of the recombinant protein. These cold-active enzymes may have huge potential for academic research and industrial applications. In addition, the capacity of the isolates to degrade various types of organic matter may indicate their unique ecological roles in the elemental biogeochemical cycling of the deep biosphere. PMID:27342115

  2. Natural Combination of Genetic Systems for Degradation of Phenol and Resistance to Heavy Metals in Phenol and Cyanide Assimilating Bacteria

    Directory of Open Access Journals (Sweden)

    El-Deeb, B.

    2009-01-01

    Full Text Available Combination of genetic systems of degradation of xenobiotic compound and heavy metal resistance is one of the approaches to the creation of polyfunctional strains for bioremediation of soil after co-contamination with organic pollutants and heavy metals. A bacterial strain Pseudomonas putida PhCN (pPhCN1, pPhCN2 has been obtained. This bacterium contains two plasmids, a 120-kb catabolic plasmid that encodes for breakdown of phenol (pPhCN1 and pPhCN2 plasmid that codes for cadmium and copper resistant. Cyanide assimilation by this bacterium is encoded by chromosomal genes. The inhibitory effect of cadmium (Cd2+ or copper (Cu2+ on the degradation of phenol by P. putida strains PhCN and PhCN1 (contained pPhCN1 were investigated in the presence of phenol and cyanide as a sole carbon and nitrogen source, respectively. The resistant strain PhCN showed high ability to degrade phenol and cyanide in presence of Cd2+ or Cu2+ as compared to the sensitive strain PhCN1. In addition, Cd2+ or Cu2+ was also found to exert a strong inhibitory effect on the C23O dioxygenase enzyme activity in the presence of cyanide as a nitrogen source. However, the presence of heavy metal resistance plasmid alleviated the inhibitory effect of metals on the enzyme activity in resistant strain.

  3. Cellulose degrading bacteria isolated from industrial samples and the gut of native insects from Northwest of Argentina.

    Science.gov (United States)

    Manfredi, Adriana P; Perotti, Nora I; Martínez, María A

    2015-12-01

    The raw materials used to produce bioethanol mostly are food crops, which has led to conflicts on food security. It is, therefore, recommended the gradual replacement for second generation substrates such as lignocellulosic materials. Herein, cellulolytic bacteria were isolated from the gut content of native larvae from Lepidoptera, Coleoptera, and adults of Isoptera. Few environmental samples from the pulp and paper feedstock were also assessed. A total of 233 isolates were obtained using enrichment cultures and classic criteria. Interestingly, several halo-forming colonies were found to be bacterial consortia that presented difficulties to take apart the microbial members. Those pure isolates which hydrolyzed cellulose in larger extend (45 strains) were selected and identified by means of 16S rRNA sequence analysis. Firmicutes was the prevalent phylum (62.2%) being Bacillus spp. the most frequent genus, while Paenibacillus, Brevibacillus, Cohnella, and Staphylococcus species were less frequent. The phylum Actinobacteria (6.7%) was represented by isolates related to Agromyces spp. and Microbacterium spp. Regarding Gram-negative bacteria (31.1%), the more depicted genus was Pseudomonas spp., and members of Achromobacter spp., Enterobacter spp., and Bacteroidetes phylum were also selected. These native bacterial strains are expected to enlarge the cellulolytic toolbox for efficient biomass deconstruction. PMID:26370071

  4. Molecular application for identification of polycyclic aromatic hydrocarbons degrading bacteria (PAHD) species isolated from oil polluted soil in Dammam, Saud Arabia.

    Science.gov (United States)

    Ibrahim, Mohamed M; Al-Turki, Ameena; Al-Sewedi, Dona; Arif, Ibrahim A; El-Gaaly, Gehan A

    2015-09-01

    Soil contamination with petroleum hydrocarbon products such as diesel and engine oil is becoming one of the major environmental problems. This study describes hydrocarbons degrading bacteria (PHAD) isolated from long-standing petrol polluted soil from the eastern region, Dammam, Saudi Arabia. The isolated strains were firstly categorized by accessible shape detection, physiological and biochemistry tests. Thereafter, a technique established on the sequence analysis of a 16S rDNA gene was used. Isolation of DNA from the bacterial strains was performed, on which the PCR reaction was carried out. Strains were identified based on 16S rDNA sequence analysis, As follows amplified samples were spontaneously sequenced automatically and the attained results were matched to open databases. Among the isolated bacterial strains, S1 was identified as Staphylococcus aureus and strain S1 as Corynebacterium amycolatum. PMID:26288572

  5. Natural Combination of Genetic Systems for Degradation of Phenol and Resistance to Heavy Metals in Phenol and Cyanide Assimilating Bacteria

    OpenAIRE

    El-Deeb, B.

    2009-01-01

    Combination of genetic systems of degradation of xenobiotic compound and heavy metal resistance is one of the approaches to the creation of polyfunctional strains for bioremediation of soil after co-contamination with organic pollutants and heavy metals. A bacterial strain Pseudomonas putida PhCN (pPhCN1, pPhCN2) has been obtained. This bacterium contains two plasmids, a 120-kb catabolic plasmid that encodes for breakdown of phenol (pPhCN1) and pPhCN2 plasmid that codes for cadmium and copp...

  6. Characterization of Carbofuran Degrading Bacteria Obtained from Potato Cultivated Soils with Different Pesticide Application Records / Caracterización de Bacterias Degradadoras de Carbofuran Obtenidas de Suelos Bajo Cultivo de Papa y con Diferente Histor

    Directory of Open Access Journals (Sweden)

    Castellanos Rozo José

    2013-08-01

    Full Text Available Abstract. Eighty-two bacterial isolates with potential Carbofurandegradation activity (Furadan®3SC were obtained from soilscultivated with the potato variety Unica (Solanum tuberosumin Silos, Norte de Santander (Colombia, with different recordsof pesticide application. The bacteria were selected for theirability to grow at 25 °C for 72 h in media containing 200 mgL-1 of analytical Carbofuran as the sole source of carbon and/or nitrogen. The results showed that ten isolates, 12% of those obtained, grew in the culture media. Eight of theses isolates were obtained from soils with a high pesticide exposure (eight years of application, and identified, by macroscopic, microscopic and biochemical characteristics, as Sphingomonas paucimobilis. The other two were obtained from soils with three years and one year of application and were identified as Pseudomonas aeruginosa and Yersinia pseudotuberculosis, respectively. Subsequently, these bacteria were tested for their ability of hydrolytic degradation of Carbofuran; the results show that the pesticide was degraded only by the isolates of Sphingomonas paucimobilis for 72 h. The results obtained in the in vitro tests show the bacterial metabolic capacity for the biodegradation of Carbofuran, highlighting the potential use of the bacteria for future field evaluation tests in places where residues of the pesticide may exist, as an alternative to control the impact that N-methyl carbamate pesticides have on the environment and human health. / Resumen. Ochenta y dos aislamientos bacterianos con actividad potencial de degradación de Carbofuran (Furadan®3SC, fueron obtenidos de suelos, cultivados con papa (Solanum tuberosum variedad Única, del municipio de Silos, Norte de Santander (Colombia con diferente historia de aplicación del plaguicida. Las bacterias fueron seleccionadas por su capacidad para crecer a 25 °C durante 72 h, en medios de cultivo conteniendo 200 mg L-1 de Carbofuran analítico como

  7. 蒸汽爆破预处理降解香蕉茎秆纤维素组分的研究%Effect of Pretreatment by Steam Explosion on Degradation of the Banana Stalk Component

    Institute of Scientific and Technical Information of China (English)

    郑丽丽; 韩冰莹; 盛占武; 陈娇; 李奕星; 赵立欣

    2014-01-01

    Total solids content (TS) and volatile solids content (VS) of banana stalk were tested, and the content of cellulose, hemicellulose and lignin. Pretreatment banana stalk by steam explosion with different pressures and different time of keeping pressure. Analysis of degradation law of banana stalk hemicellulose, cellulose and lignin content after pretreatment. The samples of the treated and untreated banana stalks were with drawn to determined cellulose, hemicelluloses and lignose contents in dry matter. The results showed that when the explosion pressure was 3.5MPa, the time of maintain steam explosion pressure was 4min, degradation rate of hemicellulose, cellulose and lignin was 67.29%, 18.99%, and 55.40%, degradation rate of the overall content was 34.41%, These results indicate that pretreatment by steam explosion can degrade cellulose of banana stalks, and hemicellulose、 lignin were degraded significantly. The method of steam explosion are further advantages such as environmentally friendly and high-efficiency.%分析测试香蕉茎秆总固体含量(TS)和挥发性固体含量(VS)及香蕉茎秆固体剩余物中纤维素、半纤维素、木质素含量;采用蒸汽爆破法对香蕉茎秆进行预处理,探讨不同压力及维压时间下对香蕉茎秆中半纤维素、纤维素、木质素组分的降解程度,分析蒸汽爆破预处理优缺点。试验结果表明,经过蒸汽爆破预处理后,香蕉茎秆的组分被不同程度破坏,当压力为3.5 MPa,维压时间为4 min 时,香蕉茎秆中半纤维素含量由预处理前13.33%降至4.36%,降解率高达67.29%,纤维素含量由48.33%降至39.15%,降解率为18.99%,木质素含量由14.62%降至6.52%,降解率为55.40%,总体含量由76.28%降至50.03%,降解率为34.41%。说明蒸汽爆破技术对香蕉茎秆固体剩余物的预处理效果比较显著,有一定的优越性。

  8. Isolation and Screening of Phenol Degrading Bacteria and its Degradation Rate in Petrochemical Industry Wastewater%石化工业污水中分离筛选苯酚降解菌及其降解率研究

    Institute of Scientific and Technical Information of China (English)

    丁海燕; 张国发; 武燕; 冯伟

    2015-01-01

    自然界中某些微生物具有较强的酚降解能力,利用微生物处理含酚废水的方法受到了越来越广泛的重视。该文通过梯度平板法从石化工业废水中分离筛选得到3株降解酚的细菌,苯酚降解率分别为90.9%、82.5%、74.9%。对其进一步深入研究,进而将其应用到工厂等污水处理方面,降低含苯酚的废水排出,具有一定的指导意义。%Some microorganisms in nature have a strong ability to degrade phenol. The method of treating phenol wastewater by microorganism has been paid more and more attention. In this article,three strains of bacteria were isolated and screened from the petrochemical industrial wastewater by gradient plate method. The degradation rate of phenol was 90.9%,82.5% and 74.9%. It has guiding significance for further study, and then appling to the plant and other wastewater treatment,reducing the wastewater containing phenol wastewater discharge.

  9. Metabolic versatility of toluene-degrading, iron-reducing bacteria in tidal flat sediment, characterized by stable isotope probing-based metagenomic analysis.

    Science.gov (United States)

    Kim, So-Jeong; Park, Soo-Je; Cha, In-Tae; Min, Deullae; Kim, Jin-Seog; Chung, Won-Hyung; Chae, Jong-Chan; Jeon, Che Ok; Rhee, Sung-Keun

    2014-01-01

    DNA stable isotope probing and metagenomic sequencing were used to assess the metabolic potential of iron-reducing bacteria involved in anaerobic aromatic hydrocarbon degradation in oil spill-affected tidal flats. In a microcosm experiment, (13) C-toluene was degraded with the simultaneous reduction of Fe(III)-NTA, which was also verified by quasi-stoichiometric (13) C-CO2 release. The metabolic potential of the dominant member affiliated with the genus Desulfuromonas in the heavy DNA fraction was inferred using assembled scaffolds (designated TF genome, 4.40 Mbp with 58.8 GC mol%), which were obtained by Illumina sequencing. The gene clusters with peripheral pathways for toluene and benzoate conversion possessed the features of strict and facultative anaerobes. In addition to the class II-type benzoyl-CoA reductase (Bam) of strict anaerobes, the class I-type (Bcr) of facultative anaerobes was encoded. Genes related to the utilization of various anaerobic electron acceptors, including iron, nitrate (to ammonia), sulfur and fumarate, were identified. Furthermore, genes encoding terminal oxidases (caa3 , cbb3 and bd) and a diverse array of genes for oxidative stress responses were detected in the TF genome. This metabolic versatility may be an adaptation to the fluctuating availability of electron acceptors and donors in tidal flats. PMID:24118987

  10. Potential probiotic lactic acid bacteria Lactobacillus rhamnosus (HN001), Lactobacillus acidophilus (HN017) and Bifidobacterium lactis (HN019) do not degrade gastric mucin in vitro.

    Science.gov (United States)

    Zhou, J S; Gopal, P K; Gill, H S

    2001-01-22

    The mucus layer (mucin) coating the surface of the gastrointestinal tract (GIT) plays an important role in the mucosal barrier system. Any damage or disturbance of this mucin layer will compromise the host's mucosal defence function. In the present study, the ability of three potential probiotic lactic acid bacteria (LAB) strains (Lactobacillus rhamnosus HN001, Lactobacillus acidophilus HN017, Bifidobacterium lactis HN019) to degrade mucin in vitro was evaluated, in order to assess their potential pathogenicity and local toxicity. The LAB strains were incubated in medium containing hog gastric mucin (HGM, 0.3%) at 37 degrees C for 48 h, following which any decrease in carbohydrate and protein concentration in the ethanol-precipitated portion of the culture medium was determined, using phenol-sulphuric acid and bicinchonic acid (BCA) protein assays, respectively. The change in molecular weight of mucin glycoproteins, following incubation with the test strains, was monitored by SDS-polyacrylamide gel electrophoresis (SDS-PAGE). In order to expose any ability of the test strains to degrade mucin visually and more directly, the test strains were also cultured on agarose containing 0.3% HGM and incubated anaerobically for 72 h at 37 degrees C. No significant change in the carbohydrate or protein concentration in mucin substrates was found following incubation with the test strains. No mucin fragments were derived from the mucin suspension incubated with test strains, and no mucinolysis zone was identified on agarose. These results demonstrate that the potential probiotic LAB strains tested here were unable to degrade gastrointestinal mucin in vitro, which suggests that these novel probiotic candidates are likely to be non-invasive and non-toxic at the mucosal interface. PMID:11205957

  11. Visible light photo catalytic inactivation of bacteria and photo degradation of methylene blue with Ag/TiO2 nanocomposite prepared by a novel method.

    Science.gov (United States)

    Tahir, Kamran; Ahmad, Aftab; Li, Baoshan; Nazir, Sadia; Khan, Arif Ullah; Nasir, Tabassum; Khan, Zia Ul Haq; Naz, Rubina; Raza, Muslim

    2016-09-01

    Water purification is one of the worldwide problem and most of the conventional methods are associated with a number of drawbacks. Therefore it is the need of the day to develop new methods and materials to overcome the problem of water purification. In this research work we present a simple and green approach to synthesize silver decorated titanium dioxide (Ag/TiO2) nanocomposite with an efficient photo catalytic activities. Phytochemicals of the Cestrum nocturnum leaf extract were used to synthesize silver nanoparticles (AgNPs), Titanium dioxide (TiO2) and Ag/TiO2 nanocomposite. To confirm the formation, crystal structure, particle size and shape of green synthesized nanoparticles and nanocomposite, they were characterized by UV-visible spectroscopy (UV-vis), X-ray diffraction spectroscopy (XRD), high resolution transmission electron microscopy (HRTEM), Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The AgNPs, TiO2 and Ag/TiO2 were evaluated for photo degradation of methylene blue (MB) and photo inhibition of Bacteria. The bio-synthesized Ag/TiO2 nanocomposite was observed to have strong catalytic activities for photo reduction of MB and photo inactivation of bacteria as compared to bare AgNPs and TiO2. In the presence of Ag/TiO2, 90% of MB was degraded only in 40min of irradiation. Alternatively the bare AgNPs and TiO2 degraded less than 30% and 80% respectively of MB even in more than 100min of irradiation. Similarly the Ag/TiO2 has very strong photo inhibition efficiency towards Escherichia coli and Pseudomonas aeruginosa. The zone of inhibition of irradiated Ag/TiO2 nanocomposites against E. coli and P. aeruginosa was 19mm and 17mm respectively which was two times higher than in dark. These promising photocatalytic activities of nanocomposite may be due to the highly decorated AgNPs over the surface of TiO2. PMID:27376463

  12. Stable carbon isotope fractionation of trans-1,2-dichloroethylene during co-metabolic degradation by methanotrophic bacteria

    Science.gov (United States)

    Brungard, K.L.; Munakata-Marr, J.; Johnson, C.A.; Mandernack, K.W.

    2003-01-01

    Changes in the carbon isotope ratio (??13C) of trans-1,2-dichloroethylene (t-DCE) were measured during its co-metabolic degradation by Methylomonas methanica, a type I methanotroph, and Methylosinus trichosporium OB3b, a type II methanotroph. In closed-vessel incubation experiments with each bacterium, the residual t-DCE became progressively enriched in 13C, indicating isotopic fractionation. From these experiments, the biological fractionation during t-DCE co-metabolism, expressed as ??, was measured to be -3.5??? for the type I culture and -6.7??? for the type II culture. This fractionation effect and subsequent enrichment in the ??13C of the residual t-DCE can thus be applied to determine the extent of biodegradation of DCE by these organisms. Based on these results, isotopic fractionation clearly warrants further study, as measured changes in the ??13C values of chlorinated solvents could ultimately be used to monitor the extent of biodegradation in laboratory or field settings where co-metabolism by methanotrophs occurs. ?? 2002 Elsevier Science B.V. All rights reserved.

  13. Protective effect of immobilized ammonia oxidizers and phenol-degrading bacteria on nitrification in ammonia- and phenol-containing wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Morita, M.; Watanabe, A. [Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI), Chiba (Japan); Kudo, N.; Shinozaki, H. [Materials Science Engineering, Tokyo Denki University, Tokyo (Japan); Uemoto, H.

    2007-12-15

    Phenol present in wastewaters from various industries has an inhibitory effect on nitrification even at low concentrations. Hence, the biological treatment of wastewater containing both phenol and ammonia involves a series of treatment steps. It is difficult to achieve nitrification capability in an activated sludge system that contains phenol at concentrations above the inhibitory level. Batch treatment of wastewater containing various concentrations of phenol showed that the ammonia oxidation capability of suspended Nitrosomonas europaea cells, an ammonia oxidizer, was completely inhibited in the presence of more than 5.0 mg/L phenol. To protect the ammonia oxidizer from the inhibitory effect of phenol and to achieve ammonia oxidation capability in the wastewater containing phenol at concentrations above the inhibitory level, a simple bacterial consortium composed of an ammonia oxidizer (N. europaea) and a phenol-degrading bacterial strain (Acinetobacter sp.) was used. Ammonia oxidation did not occur in the presence of phenol at concentrations above the inhibitory level when suspended or immobilized N. europaea and Acinetobacter sp. cells were used in batch treatment. Following the acclimatization of the immobilized cells, accumulation of nitrite was observed, even when the wastewater contained phenol at concentrations above the inhibitory level. These results showed that immobilization was effective in protecting N. europaea cells from the inhibitory effect of phenol present in the wastewater. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  14. Isolation, Identification and Characterization of Cellulose-Degradation Bacteria from Fresh Cow Dung and Fermentation Biogas Slurry

    Directory of Open Access Journals (Sweden)

    Zhou Hong-li

    2015-08-01

    Full Text Available Two new isolates designated strain MY6 and strains FY2 were isolated from the mixture of fresh cow dung and fermentation biogas slurry, which were found to be potential cellulase producers. On the basis of cellular morphology, physiological and chemotaxonomic characteristics and similarity of 16S rDNA gene sequences, the former was confirmed as Stenotrophomonas sp., while the latter was identified as Bacillus cereus sp. Key fermentation factors including culture time, initial pH and culture temperature for cellulase production were optimized using single factor experiments for the two strains. The endoglucanase (CMCase activity of MY6 was increased by 200.74% and reached 137.36 U/ml under the optimized conditions (cultured for 48 h at pH7.0 and 40°C with shaking at 160 rmp; while the activity of FY2 was enhanced by 150.61% and achieved 177.58 U/ml under the optimized conditions (cultured for 48 h at pH7.0 and 45°C with shaking at 160 rmp. The effects of four native lignocellulosic feed stocks on CMCase activities were compared. The results showed that cellulase from strains MY6 and FY2 were similar in cellulose degradation and the activity was strongest for filter paper, then for degreased cotton, straw powder and sawdust as substrates. These findings indicated that high cellulose concentration used as carbon sources could promote the generation of CMCase.

  15. The screening and identification of oil degradation bacteria producing surfactant%产表面活性剂石油降解菌株的筛选及鉴定

    Institute of Scientific and Technical Information of China (English)

    花莉; 洛晶晶; 胡阳阳; 彭香玉; 贾卫华

    2014-01-01

    7 strains degrading oil were isolated from long-term oil-contaminated soil and they were numbered as bacteria 2-1 ,bacteria 7-1 ,bacteria 1-2 ,bacteria5-2 ,bacteria 7-2 ,bacteria oil 3 ,bacteria oil 5 ,of which bacteria 2-1 and bacteria 7-1 were identified as Serratia marces-cens ,bacteria 1-2 as Raoultella planticola ,bacteria 5-2 ,bacteria oil 3 ,and bacteria oil 5 as Klebsiella genus ,bacteria 7-2 as Bacillus cereus by morphological observation ,Biolog identi-fication and 16S rDNA gene sequence analysis .Bacteria 1-2 ,bacteria 5-2 and bacteria 7-2 en-abled the surface tension of the fermentation liquid reduce from 36 .1 mN /m to 20 .2 mN /m ,20 .74 mN /m and 21 .78 mN/m ,indicating the surfactants produced by the bacteriums have a strong emulsification crude capacity and show great potential .%从长期受油污的土壤中分离得到了7株降解石油类菌株,其编号分别为菌2-1、菌7-1、菌1-2、菌5-2、菌7-2、菌油3及菌油5.经形态观察、Biolog鉴定和16S rDNA 基因序列分析,可鉴定菌2-1和菌7-1为粘质沙雷氏菌,菌1-2为居植物柔武氏菌,菌5-2、菌油3和菌油5都为克雷伯氏菌属,菌7-2为蜡状芽孢杆菌.其中,菌1-2、菌5-2和菌7-2能使发酵液的表面张力从36.10 m N/m降低至20.20 m N/m、20.74 m N/m、21.78 m N/m ,表明这些菌所产生的表面活性剂能具有较强的乳化原油的能力,展现了较大的应用前景.

  16. Effect of pH on biologic degradation of Microcystis aeruginosa by alga-lysing bacteria in sequencing batch biofilm reactors

    Institute of Scientific and Technical Information of China (English)

    Hongjing LI; Mengli HAO; Jingxian LIU; Chen CHEN1; Zhengqiu FAN; Xiangrong WANG

    2012-01-01

    In this paper, the effect of pH on biological degradation of Microcystis aeruginosa by alga-lysing bacteria in laboratory-scale sequencing batch biofilm reactors (SBBRs) was investigated. After 10 d filming with waste activated sludge, the biological film could be formed, and the bioreactors in which laid polyolefin resin filler were used to treat algal culture. By comparing the removal efficiency of chlorophyll a at different aerobic time, the optimum time was determined as 5 h. Under pH 6.5, 7.5, and 8.5 conditions, the removal rates of Microcystis aeruginosa were respectively 75.9%, 83.6%, and 78.3% (in term of chlorophyll a), and that of Chemical Oxygen Demand (CODMn) were 30.6%, 35.8%, and 33.5%. While the removal efficiencies of ammonia nitrogen (NH+ -N) were all 100%. It was observed that the sequence of the removal efficiencies of algae, NH+ -N and organic matter were pH 7.5 〉 pH 8.5 〉 pH 6.5. The results showed that the dominant alga-lysing bacteria in the SBBRs was strain HM-01, which was identified as Bacillus sp. by Polymerase Chain Reaction (PCR) amplification of the 16S rRNA gene, Basic Local Alignment Search Tool (BLAST) analysis, and compar- ison with sequences in the GenBank nucleotide database. The algicidal activated substance which HM-01 strain excreted could withstand high temperature and pressure, also had better hydrophily and stronger polarity.

  17. 纤维素降解细菌筛选及降解特性分析%Study on the screening of cellulose-degrading bacteria and the degradation characteristics

    Institute of Scientific and Technical Information of China (English)

    刘乐; 鞠美庭; 李维尊; 江洋

    2012-01-01

    In order to obtain high efficient cellulose degrading bacteria,LB medium and Congo red agar medium were used to culture and screening strains that isolated from cow dung compost. Results showed that the two obtained strains were identified as Bacillus subtilis and Bacillus licheniformis. In the filter paper decomposition experiment, the filter paper could be shaken into paste in 6 days, which indicated that the two strains had great capacity of filter paper decomposition. The sodium carboxy methyl cellulose enzyme activity of Bacillus licheniformis reached the peak value (237 U/g) at the fourth day of fermentation.%基于获得高教纤维素降解细菌的目的,通过LB培养基的培养以及刚果红培养基的筛选,从牛粪堆肥中筛选获得2株高效纤维素降解细菌.经鉴定,分别为枯草芽胞杆菌(Bacillus subtilis)和地衣芽胞杆菌(Bacillus licheniformis).所筛选得到的菌种具有很高的滤纸降解能力,可在6d内使滤纸剧烈崩溃,振摇成均匀糊状;其中,地衣芽胞杆菌的羧甲基纤维素钠酶活峰值在发酵第4天达到峰值(237 U/g).

  18. Bioreporter bacteria for landmine detection

    Energy Technology Data Exchange (ETDEWEB)

    Burlage, R.S. [Oak Ridge National Lab., TN (United States); Youngblood, T. [Frisby Technologies, Aiken, SC (United States); Lamothe, D. [American Technologies, Inc., Huntsville, AL (United States). Ordnance/Explosives Environmental Services Div.

    1998-04-01

    Landmines (and other UXO) gradually leak explosive chemicals into the soil at significant concentrations. Bacteria, which have adapted to scavenge low concentrations of nutrients, can detect these explosive chemicals. Uptake of these chemicals results in the triggering of specific bacterial genes. The authors have created genetically recombinant bioreporter bacteria that detect small concentrations of energetic chemicals. These bacteria are genetically engineered to produce a bioluminescent signal when they contact specific explosives. A gene for a brightly fluorescent compound can be substituted for increased sensitivity. By finding the fluorescent bacteria, you find the landmine. Detection might be accomplished using stand-off illumination of the minefield and GPS technology, which would result in greatly reduced risk to the deminers. Bioreporter technology has been proven at the laboratory scale, and will be tested under field conditions in the near future. They have created a bacterial strain that detects sub-micromolar concentrations of o- and p-nitrotoluene. Related bacterial strains were produced using standard laboratory protocols, and bioreporters of dinitrotoluene and trinitrotoluene were produced, screening for activity with the explosive compounds. Response time is dependent on the growth rate of the bacteria. Although frill signal production may require several hours, the bacteria can be applied over vast areas and scanned quickly, producing an equivalent detection speed that is very fast. This technology may be applicable to other needs, such as locating buried explosives at military and ordnance/explosive manufacturing facilities.

  19. Co-metabolic biodegradation of trichloroethylene by acclimated phenol degrading bacteria%三氯乙烯在苯酚菌中的共代谢降解性能研究

    Institute of Scientific and Technical Information of China (English)

    黄流雅; 胡娟; 张巍; 应维琪

    2012-01-01

    The batch experiments were carried out to investigate the co-metabolic degradation of trichloroethylene (TCE) by acclimated phenol degrading bacteria. The results showed that phenol was an essential co-substrate;the TCE degradation rate was dependent on the initial concentrations of phenol and TCE in co-metabolic degradation system. Active biodegradation of TCE followed after a short lag phase for building up a critical density of acclimated phenol degrading bacteria. A high initial TCE concentration of >9 mg/L inhibited its degradation;an initial phenol/TCE ratio of > 10-15 enhanced the final removal of TCE. The degradation curves of phenol and TCE were well represented by the Haldane inhibition model. The mixed culture bacteria had a higher affinity for phenol than TCE; phenol had competitive inhibition effect on TCE degradation;the inhibition effect of TCE to bacteria was observed in the high initial concentration runs.%通过生物降解实验考察三氯乙烯(TCE)在苯酚驯化微生物中的共代谢降解性能,并进行动力学分析.结果表明,苯酚是TCE苯酚共代谢过程必不可少的共代谢基质;TCE的共代谢降解与苯酚和TCE初始浓度有关.TCE在降解初期会出现一个短暂的迟滞期,TCE的大量降解要在苯酚被利用后才发生;高质量浓度TCE (>9 mg/L)对共代谢降解有抑制作用.苯酚/TCE(质量比)在10~15以上时,苯酚菌对TCE的去除率较大.Haldane模型能够很好地拟合苯酚和TCE的比降解速率.动力学分析表明,微生物对苯酚的亲和力要大于TCE,苯酚对TCE共降解具有竞争性抑制作用,TCE对微生物存在毒性抑制作用;结果证实了生物降解实验的结论.

  20. Explosive laser

    Science.gov (United States)

    Robinson, C.P.; Jensen, R.J.; Davis, W.C.; Sullivan, J.A.

    1975-09-01

    This patent relates to a laser system wherein reaction products from the detonation of a condensed explosive expand to form a gaseous medium with low translational temperature but high vibration population. Thermal pumping of the upper laser level and de-excitation of the lower laser level occur during the expansion, resulting in a population inversion. The expansion may be free or through a nozzle as in a gas-dynamic configuration. In one preferred embodiment, the explosive is such that its reaction products are CO$sub 2$ and other species that are beneficial or at least benign to CO$sub 2$ lasing. (auth)

  1. Explosive laser

    International Nuclear Information System (INIS)

    This patent relates to a laser system wherein reaction products from the detonation of a condensed explosive expand to form a gaseous medium with low translational temperature but high vibration population. Thermal pumping of the upper laser level and de-excitation of the lower laser level occur during the expansion, resulting in a population inversion. The expansion may be free or through a nozzle as in a gas-dynamic configuration. In one preferred embodiment, the explosive is such that its reaction products are CO2 and other species that are beneficial or at least benign to CO2 lasing

  2. LABELING OF BIURET DEGRADING BACTERIA WITH GFP AND COLONIZATION OF THE BACTERIA IN CROP RHIZOSPHERE%缩二脲降解菌在作物根际的GFP标记示踪

    Institute of Scientific and Technical Information of China (English)

    平泉瑞; 陆艳娜; 黄为一

    2012-01-01

    通过三亲结合对缩二脲降解菌GW-1菌株成功进行了绿色荧光蛋白(Green fluorescent protein,GFP)基因标记,标记菌株命名为GW-1-GFP.实验证明外源质粒对宿主菌的生长未带来不利的影响,且经高效液相色谱测定该标记菌株降解缩二脲的能力与出发菌株无显著差异(p<0.05).经抗生素抗性和荧光追踪证明标记菌株GW-1-GFP能够很好地在土壤中定殖,第25天时在不同处理的土壤中标记菌株对缩二脲的降解能力都超过50%,45 d后该标记菌株在土壤中已难以检测.经标记菌株GW-1-GFP菌悬液浸润的小麦种子发芽后,通过荧光观察显示降解缩二脲的标记菌株GW-1-GFP在小麦根部定殖良好,且该标记菌株能在一定程度上缓解缩二脲对小麦的毒害作用.该研究为验证、追踪土壤中功能微生物菌剂与作物根部的亲和性和生态有效性提供了简易、直观的检测方法.%Strains of biuret-degrading bacteria GW-1 were successfully isolated and labeled with green fluorescent protein with the triparental mating method and then the GFP-tagged strains were named GW-1-GFP. The expression of GFP in Strain GW-1-GFP was visualized under the fluorescent microscope and its dynamics was analyzed and stability tested. It was found that heterogenous plasmid did not bring any adverse effect to growth of the host strain GW-1-GFP and the strain was stable. HPLC analysis did not show any significant difference (p < 0. 05 ) between the origin stain GW-1 and the tagged strain GW-1-GFP in biuret-degrading ability. The tagged strain GW-1-GFP, proved by the antibiotics resistance screening and fluorescence tracing, could colonize well in the soil and was found to have degraded 50% of the biuret in soil in all the treatments on D25 after the application of Strain GW-1-GFP. It was also found in the experiment that the tagged strain was safe to the environment and vanished from the soil after 45 days. Good colonization of Strain

  3. Explosive complexes

    Science.gov (United States)

    Huynh, My Hang V.

    2009-09-22

    Lead-free primary explosives of the formula [M.sup.II(A).sub.R(B.sup.X).sub.S](C.sup.Y).sub.T, where A is 1,5-diaminotetrazole, and syntheses thereof are described. Substantially stoichiometric equivalents of the reactants lead to high yields of pure compositions thereby avoiding dangerous purification steps.

  4. Identification of two high-efficiency hexadecane-degrading bacteria and their degradation characteristics%两株高效石油烃氧化菌的正十六烷降解特性

    Institute of Scientific and Technical Information of China (English)

    张洁; 王卫卫; 郭欣; 王楠; 陶发琴

    2013-01-01

    研究从长庆、延长油田油泥中分离出的两株高效石油烃氧化菌PDA2(红球菌属)和PDB3(假单胞菌属)对正十六烷的降解特性和各降解特性之间进行关联分析.测定菌株在不同温度、pH、底物浓度、接种量、盐度和H2O2条件下菌株对正十六烷的降解率,并测定降解过程中表面活性剂、乳化剂、酸的产量和细胞表面疏水性变化.PDB3在30℃,pH7,初始正十六烷浓度1%,接种量5%,H2O2600 mg/L时可以降解98.5%的正十六烷,PDA2在30℃,pH7,初始十六烷浓度1%,接种量5%,H2O2400 mg/L时,可以降解89.4%的正十六烷,PDB3培养72 h产生3.8 cm的排油圈、336mg/L的酸、55%的乳化率,PDA2培养72 h产生1.5 cm的排油圈、362 mg/L的酸、35%的乳化率,PDB3和PDA2在十六烷培养液中的疏水性与在葡萄糖培养液中的疏水性没有发生明显改变.在温度为45℃,盐度为1%~3%时,两株菌对正十六烷降解率超过50%,添加适量H2 O2促进菌株对正十六烷的降解;细胞产生的表面活性剂和乳化剂协同作用促进菌株对正十六烷的降解,表面活性剂的产生并没有增加菌株细胞表面的疏水性,疏水性弱(低于10%)的细胞产生的表面活性剂多.这两株自身产表面活性剂的菌株对后续石油烃降解的理论及应用研究具有重要意义.%To Study the hexadecane degradation characteristics of two high performance hydrocarbon oxidation bacteria strains of PDB3 (Pseudomonas sp.) and PDA2 (Rhodococcs s-p.) isolated from oil contaminated soil in Changqing and YanChang oil fields,and analyse the relationships among the characteristics.The characteristics of the two strains were conducted including etabolized surfactant,emulsifier,acid,the change of cell surface hydrophobicity and the hexadecane degradation rates under different temperature,pH,the concentration of hexadecane,inoculum size,salinity and H2O2 content.The degradation ratio of 1% hexadecane could

  5. Explosive Joining

    Science.gov (United States)

    1989-01-01

    Laurence J. Bement of Langley Research Center invented a technique to permit metal joining operations under hazardous or inaccessible conditions. The process, which provides a joint with double the strength of the parent metal, involves the use of very small quantities of ribbon explosive to create hermetically sealed joints. When the metal plates are slammed together by the explosion's force, joining is accomplished. The collision causes a skin deep melt and ejection of oxide films on the surfaces, allowing a linkup of electrons that produce superstrong, uniform joints. The technique can be used to join metals that otherwise would not join and offers advantages over mechanical fasteners and adhesives. With Langley assistance, Demex International Ltd. refined and commercialized the technology. Applications include plugging leaking tubes in feedwater heaters. Demex produces the small plugs, associated sleeves and detonators. The technology allows faster plugging, reduces downtime, cuts plugging costs and increases reliability.

  6. Explosive simulants for testing explosive detection systems

    Science.gov (United States)

    Kury, John W.; Anderson, Brian L.

    1999-09-28

    Explosives simulants that include non-explosive components are disclosed that facilitate testing of equipment designed to remotely detect explosives. The simulants are non-explosive, non-hazardous materials that can be safely handled without any significant precautions. The simulants imitate real explosives in terms of mass density, effective atomic number, x-ray transmission properties, and physical form, including moldable plastics and emulsions/gels.

  7. Leidenfrost explosions

    CERN Document Server

    Moreau, F; Dorbolo, S

    2012-01-01

    We present a fluid dynamics video showing the behavior of Leidenfrost droplets composed by a mixture of water and surfactant (SDS, Sodium Dodecyl sulfate). When a droplet is released on a plate heated above a given temperature a thin layer of vapor isolates the droplet from the plate. The droplet levitates over the plate. This is called the Leidenfrost effect. In this work we study the influence of the addition of a surfactant on the Leidenfrost phenomenon. As the droplet evaporates the concentration of SDS rises up to two orders of magnitude over the Critical Micelle Concentration (CMC). An unexpected and violent explosive behavior is observed. The video presents several explosions taken with a high speed camera (IDT-N4 at 30000 fps). All the presented experiments were performed on a plate heated at 300{\\deg}C. On the other hand, the initial quantity of SDS was tuned in two ways: (i) by varying the initial concentration of SDS and (ii) by varying the initial size of the droplet. By measuring the volume of th...

  8. Chaotic Explosions

    CERN Document Server

    Altmann, Eduardo G; Tél, Tamás

    2015-01-01

    We investigate chaotic dynamical systems for which the intensity of trajectories might grow unlimited in time. We show that (i) the intensity grows exponentially in time and is distributed spatially according to a fractal measure with an information dimension smaller than that of the phase space,(ii) such exploding cases can be described by an operator formalism similar to the one applied to chaotic systems with absorption (decaying intensities), but (iii) the invariant quantities characterizing explosion and absorption are typically not directly related to each other, e.g., the decay rate and fractal dimensions of absorbing maps typically differ from the ones computed in the corresponding inverse (exploding) maps. We illustrate our general results through numerical simulation in the cardioid billiard mimicking a lasing optical cavity, and through analytical calculations in the baker map.

  9. Isolation and characterization of RDX-degrading Rhodococcus species from a contaminated aquifer.

    Science.gov (United States)

    Bernstein, Anat; Adar, Eilon; Nejidat, Ali; Ronen, Zeev

    2011-09-01

    Groundwater contamination by the explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a global problem. Israel's coastal aquifer was contaminated with RDX. This aquifer is mostly aerobic and we therefore sought aerobic bacteria that might be involved in natural attenuation of the compound in the aquifer. RDX-degrading bacteria were captured by passively sampling the indigenous bacteria onto sterile sediments placed within sampling boreholes. Aerobic RDX biodegradation potential was detected in the sediments sampled from different locations along the plume. RDX degradation with the native sampled consortium was accompanied by 4-nitro-2,4-diazabutanal formation. Two bacterial strains of the genus Rhodococcus were isolated from the sediments and identified as aerobic RDX degraders. The xplA gene encoding the cytochrome P450 enzyme was partially (~500 bp) sequenced from both isolates. The obtained DNA sequences had 99% identity with corresponding gene fragments of previously isolated RDX-degrading Rhodococcus strains. RDX degradation by both strains was prevented by 200 μM of the cytochrome P450 inhibitor metyrapone, suggesting that cytochrome P450 indeed mediates the initial step in RDX degradation. RDX biodegradation activity by the T7 isolate was inhibited in the presence of nitrate or ammonium concentrations above 1.6 and 5.5 mM, respectively (100 mg l(-1)) while the T9N isolate's activity was retarded only by ammonium concentrations above 5.5 mM. This study shows that bacteria from the genus Rhodococcus, potentially degrade RDX in the saturated zone as well, following the same aerobic degradation pathway defined for other Rhodococcus species. RDX-degrading activity by the Rhodococcus species isolate T9N may have important implications for the bioremediation of nitrate-rich RDX-contaminated aquifers. PMID:21327803

  10. Widespread occurrence of the tfd-II genes in soil bacteria revealed by nucleotide sequence analysis of 2,4-dichlorophenoxyacetic acid degradative plasmids pDB1 and p712.

    Science.gov (United States)

    Kim, Dong-Uk; Kim, Min-Sun; Lim, Jong-Sung; Ka, Jong-Ok

    2013-05-01

    Variovorax sp. strain DB1 and Pseudomonas pickettii strain 712 are 2,4-dicholorophenoxy-acetic acid (2,4-D)-degrading bacteria, which were isolated from agricultural soils in Republic of Korea and USA, respectively. Each strain harbors a 2,4-D degradative plasmid and is able to utilize 2,4-D as the sole source of carbon for its growth. The 2,4-D degradative plasmid pDB1 of strain DB1 consisted of a 65,269-bp circular molecule with a G+C content of 66.23% and had 68 ORFs. The 2,4-D degradative plasmid p712 of strain 712 was composed of a 62,798-bp circular molecule with a 62.11% G+C content and had 62 ORFs. The plasmids pDB1 and p712 share significantly homologous 2,4-D degradative genes with high similarity to the tfdR, tfdB-II, tfdC-II, tfdD-II, tfdE-II, tfdF-II, tfdK and tfdA genes of plasmid pJP4 of Alcaligenes eutrophus isolated from Australia. In a phylogenetic analysis with trfA, traL, and trbA genes, pDB1 belonged to IncP-1β with pJP4, while p712 belonged to IncP-1ε with pKJK5 and pEMT3. The results indicated that, in spite of the differences in their backbone regions, the 2,4-D catabolic genes of the two plasmids were closely related and also related to the well-known 2,4-D degradative plasmid pJP4 even though all were isolated from different geographic regions. Other similarities in the genetic organization and the presence of IS1071 suggested that these catabolic genes may be on a transposable element, leading to widespread occurrence in soil bacteria. PMID:23376020

  11. Isolation of Polymer-Degrading Bacteria and Characterization of the Hindgut Bacterial Community from the Detritus-Feeding Larvae of Tipula abdominalis (Diptera: Tipulidae)▿

    OpenAIRE

    Cook, Dana M.; DeCrescenzo Henriksen, Emily; Upchurch, Rima; Peterson, Joy B. Doran

    2007-01-01

    The Tipula abdominalis larval hindgut microbial community presumably facilitates digestion of the lignocellulosic diet. The microbial community was investigated through characterization of bacterial isolates and analysis of 16S rRNA gene clone libraries. This initial study revealed novel bacteria and provides a framework for future studies of this symbiosis.

  12. Enzymes involved in a degradation of explosives

    Czech Academy of Sciences Publication Activity Database

    Vaněk, Tomáš; Nepovím, Aleš

    Athens : Agricultural University of Athens, 2000, s. 88-91. [COST Action 837. Phytoremediation 2000 State of the Art in Europe. Scientific Workshop /1./. Hersonissos (GR), 06.04.2000-08.04.2000] Institutional research plan: CEZ:AV0Z4055905 Subject RIV: CE - Biochemistry

  13. Extrusion cast explosive

    Science.gov (United States)

    Scribner, Kenneth J.

    1985-01-01

    Improved, multiphase, high performance, high energy, extrusion cast explosive compositions, comprising, a crystalline explosive material; an energetic liquid plasticizer; a urethane prepolymer, comprising a blend of polyvinyl formal, and polycaprolactone; a polyfunctional isocyanate; and a catalyst are disclosed. These new explosive compositions exhibit higher explosive content, a smooth detonation front, excellent stability over long periods of storage, and lower sensitivity to mechanical stimulants.

  14. Characterization of N-acylhomoserine lactone-degrading bacteria associated with the Zingiber officinale (ginger rhizosphere: Co-existence of quorum quenching and quorum sensing in Acinetobacter and Burkholderia

    Directory of Open Access Journals (Sweden)

    Chhabra Siri

    2011-03-01

    Full Text Available Abstract Background Cell-to-cell communication (quorum sensing (QS co-ordinates bacterial behaviour at a population level. Consequently the behaviour of a natural multi-species community is likely to depend at least in part on co-existing QS and quorum quenching (QQ activities. Here we sought to discover novel N-acylhomoserine lactone (AHL-dependent QS and QQ strains by investigating a bacterial community associated with the rhizosphere of ginger (Zingiber officinale growing in the Malaysian rainforest. Results By using a basal growth medium containing N-(3-oxohexanoylhomoserine lactone (3-oxo-C6-HSL as the sole source of carbon and nitrogen, the ginger rhizosphere associated bacteria were enriched for strains with AHL-degrading capabilities. Three isolates belonging to the genera Acinetobacter (GG2, Burkholderia (GG4 and Klebsiella (Se14 were identified and selected for further study. Strains GG2 and Se14 exhibited the broadest spectrum of AHL-degrading activities via lactonolysis while GG4 reduced 3-oxo-AHLs to the corresponding 3-hydroxy compounds. In GG2 and GG4, QQ was found to co-exist with AHL-dependent QS and GG2 was shown to inactivate both self-generated and exogenously supplied AHLs. GG2, GG4 and Se14 were each able to attenuate virulence factor production in both human and plant pathogens. Conclusions Collectively our data show that ginger rhizosphere bacteria which make and degrade a wide range of AHLs are likely to play a collective role in determining the QS-dependent phenotype of a polymicrobial community.

  15. Increased populations of PCB-degrading bacteria in bulk soil beneath certain trees: the potential role of plant phenolics and root turnover

    Czech Academy of Sciences Publication Activity Database

    Leigh, M. B.; Fletcher, J. S.; Nagle, D. P.; Macková, Martina; Macek, Tomáš

    Neuherberg: GSF, 2005. s. 222. ISSN 0721-1694. [Rhizosphere 2004 - Perspectives and Challenges - A Tribute to Lorenz Hiltner. 12.09.2004-17.09.2004, Mnichov] Institutional research plan: CEZ:AV0Z4055905 Keywords : PCB degradation Subject RIV: DK - Soil Contamination ; De-contamination incl. Pesticides

  16. Draft Genome Sequences of Pseudomonas fluorescens BS2 and Pusillimonas noertemannii BS8, Soil Bacteria That Cooperate To Degrade the Poly- -D-Glutamic Acid Anthrax Capsule

    KAUST Repository

    Stabler, R. A.

    2013-01-24

    A mixed culture of Pseudomonas fluorescens BS2 and Pusillimonas noertemannii BS8 degraded poly-γ-d-glutamic acid; when the 2 strains were cultured separately, no hydrolytic activity was apparent. Here we report the draft genome sequences of both soil isolates.

  17. Key high molecular weight PAH-degrading bacteria in a soil consortium enriched using a sand-in-liquid microcosm system.

    Science.gov (United States)

    Tauler, Margalida; Vila, Joaquim; Nieto, José María; Grifoll, Magdalena

    2016-04-01

    A novel biphasic system containing mineral medium and sand coated with a biologically weathered creosote-PAH mixture was developed to specifically enrich the high molecular weight polycyclic aromatic hydrocarbon (HMW PAH)-degrading community from a creosote-polluted soil. This consortium (UBHP) removed 70 % of the total HMW PAHs and their alkyl-derivatives in 12 weeks. Based on a combined culture-dependent/independent approach, including clone library analysis, detection of catabolic genes, metabolomic profiles, and characterization of bacterial isolates, 10 phylotypes corresponding to five major genera (Sphingobium, Sphingomonas, Achromobacter, Pseudomonas, and Mycobacterium) were pointed out as key players within the community. In response to exposure to different single PAHs, members of sphingomonads were associated to the utilization of phenanthrene, fluoranthene, benzo[a]anthracene, and chrysene, while the degradation of pyrene was mainly associated to low-abundance mycobacteria. In addition to them, a number of uncultured phylotypes were detected, being of special relevance a group of Gammaproteobacteria closely related to a group previously associated with pyrene degradation that were here related to benzo(a)anthracene degradation. The overall environmental relevance of these phylotypes was confirmed by pyrosequencing analysis of the microbial community shift in the creosote-polluted soil during a lab-scale biostimulation. PMID:26637425

  18. The detrimental influence of bacteria (E. coli, Shigella and Salmonella) on the degradation of organic compounds (and vice versa) in TiO2 photocatalysis and near-neutral photo-Fenton processes under simulated solar light.

    Science.gov (United States)

    Moncayo-Lasso, Alejandro; Mora-Arismendi, Luis Enrique; Rengifo-Herrera, Julián Andrés; Sanabria, Janeth; Benítez, Norberto; Pulgarin, César

    2012-05-01

    TiO2 photocatalytic and near-neutral photo-Fenton processes were tested under simulated solar light to degrade two models of natural organic matter - resorcinol (R) (which should interact strongly with TiO2 surfaces) and hydroquinone (H) - separately or in the presence of bacteria. Under similar oxidative conditions, inactivation of Escherichia coli, Shigella sonnei and Salmonella typhimurium was carried out in the absence and in the presence of 10 mg L(-1) of R and H. The 100% abatement of R and H by using a TiO2 photocatalytic process in the absence of bacteria was observed in 90 min for R and in 120 min for H, while in the presence of microorganisms abatement was only of 55% and 35% for R and H, respectively. Photo-Fenton reagent at pH 5.0 completely removed R and H in 40 min, whereas in the presence of microorganisms their degradation was of 60% to 80%. On the other hand, 2 h of TiO2 photocatalytic process inactivated S. typhimurium and E. coli cells in three and six orders of magnitude, respectively, while S. sonnei was completely inactivated in 10 min. In the presence of R or H, the bacterial inactivation via TiO2 photocatalysis was significantly decreased. With photo-Fenton reagent at pH 5 all the microorganisms tested were completely inactivated in 40 min of simulated solar light irradiation in the absence of organics. When R and H were present, bacterial photo-Fenton inactivation was less affected. The obtained results suggest that in both TiO2 and iron photo-assisted processes, there is competition between organic substances and bacteria simultaneously present for generated reactive oxygen species (ROS). This competition is most important in heterogeneous systems, mainly when there are strong organic-TiO2 surface interactions, as in the resorcinol case, suggesting that bacteria-TiO2 interactions could play a key role in photocatalytic cell inactivation processes. PMID:22370626

  19. Degradation and mineralization of petroleum by two bacteria isolated from coastal waters. Degradation and mineralization of petroleum in sea water: limitation by nitrogen and phosphorus. Technical report No. 2, January-December 1971

    Energy Technology Data Exchange (ETDEWEB)

    Atlas, R.M.; Bartha, R.

    1971-12-31

    Within the framework of a study on the oil biodegradation potential of the sea the ability of a Flavobacterium sp. and Brevibacterium sp. to metabolize a paraffinic crude oil and a chemically defined hydrocarbon mixture was investigated. Major components of the crude oil were identified by combination gas chromatography and mass spectrometry. The rate and extent of total hydrocarbon biodegradation was measured. Degradation started after a 2 to 4 day lag period, and reached its maximum within two weeks. At this time up to 60% of the crude oil was degraded. n-Paraffins were preferentially degraded as compared to branched chain hydrocarbons. Biodegradation and mineralization of petroleum, added at 1% (v/v) to freshly collected sea water, were measured using gas-liquid chromatographic, residual weight, and CO/sub 2/-evolution techniques. Only 3% of the added petroleum was biodegraded and 1% was mineralized in unamended sea water after 18 days and incubation. Added nitrate, phosphate supplements in combination increased petroleum biodegradation and mineralization. Attempts to clean up oil spills with the aid of microorganisms should take into consideration the nutritional deficiencies of sea water.

  20. Understanding vented gas explosions

    Energy Technology Data Exchange (ETDEWEB)

    Lautkaski, R. [VTT Energy, Espoo (Finland). Energy Systems

    1997-12-31

    The report is an introduction to vented gas explosions for nonspecialists, particularly designers of plants for flammable gases and liquids. The phenomena leading to pressure generation in vented gas explosions in empty and congested rooms are reviewed. The four peak model of vented gas explosions is presented with simple methods to predict the values of the individual peaks. Experimental data on the external explosion of dust and gas explosions is discussed. The empirical equation relating the internal and external peak pressures in vented dust explosions is shown to be valid for gas explosion tests in 30 m{sup 3} and 550 m{sup 3} chambers. However, the difficulty of predicting the internal peak pressure in large chambers remains. Methods of explosion relief panel design and principles of vent and equipment layout to reduce explosion overpressures are reviewed. (orig.) 65 refs.

  1. Analysis of Soil Micro-environment in Nanyang Oil Field and Screening of Oil Degrading Bacteria%南阳油污土壤微环境分析及石油降解菌筛选

    Institute of Scientific and Technical Information of China (English)

    押辉远; 易力; 周胜利; 张祥胜

    2011-01-01

    Some physical and chemical properties of the polluted soil on Nanyang oil field were investigated, and the influence of the physical and chemical factors on the micro-organisms was analyzed. In addition, strains which had stronger degrading capacity were screened from oil polluted soil through the method of enrichment culture, using petroleum as the sole carbon source. The result indicated that the pH index and water content of the soil on Nanyang oil field was comparatively beneficial for the degradation of petroleum. The amount of bacteria in the polluted soil on Nanyang oil field was positively correlated with the degree of oil polution. Twenty kinds of hydrocarbon-degrading bacteria were isolated from the polluted soil.Among them, NY-2#, NY-7#, and the NY-17# strains had better degrading capacity, whose respective petroleumdegradation rate achieved 47.8%, 51.2% and 46.3% respectively.%测定了南阳油田石油污染土壤的一些理化性质,分析各种理化因子对其中的微生物的影响,并通过用以石油为单一碳源的培养基富集培养的方法从油污土壤中筛选降油菌株,还对它们的降油能力进行了评价.结果表明,南阳油田油污土壤的pH值、含水率等指标较有利于原油的降解,且南阳油田石油污染的土壤中的细菌数量与土壤的污染程度呈正相关.在这些油污土壤中共筛选到20株石油降解菌,其中NY-2、NY-7、和NY-17菌株的除油能力较强,它们的石油降解率分别达到47.8%、51.2%和463%.

  2. Comparison of TiO2 and ZnO nanoparticles for photocatalytic degradation of methylene blue and the correlated inactivation of gram-positive and gram-negative bacteria

    International Nuclear Information System (INIS)

    Titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles are important photocatalysts and as such have been extensively studied for the removal of organic compounds from contaminated air and water and for microbial disinfection. Despite much research on the effect of TiO2 and ZnO nanoparticles on different bacterial species, uncertainties remain about which bacteria are more sensitive to these compounds. Very few studies have directly compared the toxicity of ZnO to TiO2 under both light and dark conditions. In addition, authors investigating the photocatalytic inactivation of TiO2 and ZnO nanoparticles on bacteria have failed to investigate the reactive oxygen species (ROS) generation of the nanoparticles, making it difficult to correlate killing action with the generation of ROS. In this study, three types of metal nanoparticle (ZnO 2) have been characterised and ROS production assessed through the degradation of methylene blue (MB). The photocatalytic killing potential of three nanoparticle concentrations (0.01, 0.1 and 1 g/L) was then assessed on four representative bacteria: two gram-positive (S. aureus and B. subtilis) and two gram-negative (E. coli and P. aeruginosa). Results showed that out of the three nanoparticles tested, the TiO2 nanoparticles generated more ROS than the ZnO nanoparticles, corresponding to a greater photocatalytic inactivation of three of the four species of bacteria examined. The MB decomposition results correlated well with the bacterial inactivation results with higher TiO2 nanoparticle concentrations leading to greater ROS production and increased loss of cell viability. Although producing less ROS than the TiO2 nanoparticles under ultraviolet light, the ZnO nanoparticles were toxic to two of the bacterial species even under dark conditions. In this study, no correlation between cell wall type and bacterial inactivation was observed for any of the nanoparticles tested although both gram-positive bacteria were sensitive to ROS

  3. tfdA-Like Genes in 2,4-Dichlorophenoxyacetic Acid-Degrading Bacteria Belonging to the Bradyrhizobium-Agromonas-Nitrobacter-Afipia Cluster in α-Proteobacteria

    OpenAIRE

    Itoh, Kazuhito; Kanda, Rie; Sumita, Yoko; Kim, Hongik; Kamagata, Yoichi; Suyama, Kousuke; Yamamoto, Hiroki; Hausinger, Robert P.; Tiedje, James M.

    2002-01-01

    The 2,4-dichlorophenoxyacetate (2,4-D)/α-ketoglutarate dioxygenase gene (tfdA) homolog designated tfdAα was cloned and characterized from 2,4-D-degrading bacterial strain RD5-C2. This Japanese upland soil isolate belongs to the Bradyrhizobium-Agromonas-Nitrobacter-Afipia cluster in the α subdivision of the class Proteobacteria on the basis of its 16S ribosomal DNA sequence. Sequence analysis showed 56 to 60% identity of tfdAα to representative tfdA genes. A MalE-TfdAα fusion protein expressed...

  4. Fast Chromatographic Method for Explosive Profiling

    Directory of Open Access Journals (Sweden)

    Pierre-Hugues Stefanuto

    2015-05-01

    Full Text Available Security control is becoming a major global issue in strategic locations, such as airports, official buildings, and transit stations. The agencies responsible for public security need powerful and sensitive tools to detect warfare agents and explosives. Volatile signature detection is one of the fastest and easiest ways to achieve this task. However, explosive chemicals have low volatility making their detection challenging. In this research, we developed and evaluated fast chromatographic methods to improve the characterization of volatile signatures from explosives samples. The headspace of explosives was sampled with solid phase micro-extraction fiber (SPME. Following this step, classical gas chromatography (GC and comprehensive two-dimensional GC (GC×GC were used for analysis. A fast GC approach allows the elution temperature of each analyte to be decreased, resulting in decreased thermal degradation of sensitive compounds (e.g., nitro explosives. Using fast GC×GC, the limit of detection is further decreased based on the cryo-focusing effect of the modulator. Sampling of explosives and chromatographic separation were optimized, and the methods then applied to commercial explosives samples. Implementation of fast GC methods will be valuable in the future for defense and security forensics applications.

  5. Screening and Isolation of Bacteria Degrading Herbicide Glyphosate and Its Degradation Efficiency%草甘膦降解菌的分离及其降解效能研究

    Institute of Scientific and Technical Information of China (English)

    尚轶; 沈慧敏; 杨顺义; 汪春益; 吴永波

    2011-01-01

    从受草甘膦污染严重的土壤中富集、筛选并分离到1株降解菌G1,采用室内测定方法,对该菌株的生物学特性、对草甘膦的降解效能及对草甘膦的耐受性进行了初步研究.结果表明,菌株G1能以草甘膦作为惟一的碳源生长.在含有草甘膦的培养基上其降解率达71.76%,最适抗草甘膦浓度为300mmol/L,对草甘膦的抗性浓度在500mmol/L以下.%Glyphosate is commonly used as an organophosphate herbicide in the world. But the continuous usage of the herbicide will pollute environment seriously. Biodegradation is an effective way of bioremedying the polluted soil. One strain capable of degrading herbicide glyphosate was screened and isolated from the glyphosate polluted soil. The strain Gl was selected and primarily studied. The results showed that glyphosate could be used as the sole carbon source of G1 ,and the degradation rate of G1 were 71.76%. G1 could grow exuberantly in glyphosate solution of 300 mmol/L, but it would be restrict when the glyphosate solution was above 500 mmol/L.

  6. Evaluation of various organic fertilizer substrates and hydraulic retention times for enhancing anaerobic degradation of explosives-contaminated groundwater while using constructed wetlands at the Milan Army Ammunition Plant, Milan, Tennessee. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Behrends, L.L.; Almond, R.A.; Kelly, D.A.; Phillips, W.D.; Rogers, W.J.

    1998-05-01

    This document describes studies conducted at the Milan Army Ammunition Plant (MAAP) to improve the design, operation, and cost of gravel-based anaerobic cells when phytoremediating explosives-contaminated groundwater. To conduct this study, small-scale anaerobic test cells were used to determine: (1) If the hydraulic retention time of a large demonstration-scale anaerobic cell at MAAP could be reduced, and (2) if other carbon sources could be used as an anaerobic feedstock. The study results indicated that: (1) The existing anaerobic cell`s 7.5-day retention time should not be reduced since residual explosive by-products were present in the effluent of treatments with a 3.5-day retention time. (2) Daily application of a relatively soluble substrate, such as molasses syrup, will provide better explosives removal than periodic application of less soluble substrates like milk replacement starter and sewage sludge. (3) Molasses syrup could be, and should be, used as a substitute for milk replacement power. The recommendation to use molasses syrup was based on: (1) The lower cost of molasses syrup as compared to milk replacement starter, (2) molasses syrup`s higher solubility (which makes it easier to apply), and (3) molasses syrup`s ability to provide enhanced explosives removal.

  7. 新疆油污土壤中石油烃降解菌筛选及鉴定%Screen and identification of oH-degrading bacteria from oil polluted soil in Xingjiang

    Institute of Scientific and Technical Information of China (English)

    孙玉萍; 王红英; 刘素辉; 倪萍; 马海梅

    2011-01-01

    Objective To isolate and identify petroleum-degrading bacteria from oil-polluted soil in Karamay of Xinjiang Uyghur Autonomous Region. Methods By enriching the polluted soil with petroleum hydrocarbons as the only carbon source,the oil-degradation bacterium from oil-contaminated soil was screened and identified by its 16S rDNA sequencing. Then basic local alignment search tool( BLAST) was used to indicate the sequence of the isolates from the GenBank. Results Totally 18 bacteria strains were isolated and identified from oil-polluted soil. The sequence of its 16S rDNA indicated that there were 98% of homology to the representative strains. The main strain were Pseudomonas sp. , Planococcus sp. , Arthrobacter sp. ,Psychrobacter sp. ,Brevibacillus agri sp. ,and Brevundimonas sp.. The bacteria strains from different oil-polluted soil were different and there were more bacteria strains in heavy oil-polluted soil. Conclusion The main strain was Pseudomonas sp. In oil-polluted soid and the bacteria strains were different in different oil-polluted soil.%目的 从新疆克拉玛依油田油污土壤中筛选具有降解能力的菌株,为今后构建本源石油降解微生物菌群提供技术支持和菌种储备.方法通过以石油烃为唯一碳源的选择培养基的分离培养,获得能够利用石油烃为碳源的菌株,并通过16S rDNA序列测定方法对菌株进行鉴定.结果分离得到18株能以石油作为唯一碳源和能源的石油降解菌株,通过序列分析,初步鉴定为假单胞菌属(Pseudomonas sp.)、动性球菌属(Planococcus sp.)、节杆菌属(Arthrobacter sp.)、嗜冷杆菌(Psychrobacter sp.)、短杆菌属(Brevibacillus agri sp.)等5类.在不同土壤中分离出的降解菌株不同,含油量较高的土壤中种类较多.结论新疆克拉玛依油田油污土壤中的石油降解菌株以假单胞菌属为主,而且随着污染严重程度的不同降解菌株的种类也不同.

  8. 1株乙羧氟草醚降解菌的分离鉴定与降解特性研究%Isolation and Identification of a Strain of Fluoroglycofen Degradation Bacteria and Its Degradation Research

    Institute of Scientific and Technical Information of China (English)

    陈晓娟; 王青玲

    2011-01-01

    In this study, a bacterial strain using fluoroglycofen as sole carbon source was isolated from activated sludge of wastewater treatment tank in an insecticide factory. It was identified by physiological-biochemical identification and 16S rRNA gene sequences homology analysis, it belonged to Staphylococcus saprophyticus. The strain was named as YSC-1 and its growth was studied. The results showed that the optimum growth conditions for YSC-1 were 30℃ and pI-I 7. 0. The concentration of Nacl affected the growth significantly. The strain degraded fluoroglycofen at temperature of 20℃ -40℃ with the maximum fluoroglyoofen degrading rate at 30℃ and 7. 0, respectively. Increasing concentration of tluoroglycofen resulted in toxic effect on strain YSC-lto reduced the biodegradation rate. Increasing inoculums volume would speed up the degradation of tluoroglycofen. For industrial wastewater treated for seven days with final fluoroglycofen concentration of 100 mg/L, the removal rate reached 91.62%, which showed that the strain YSC-1 had a good application prospect for treatment of wastcwater.%本研究从某农药厂污水处理池的活性污泥中分离得到1株能以乙羧氟草醚为唯一碳源生长的菌株。经生理生化鉴定和16SrRNA基因序列同源性分析,将此菌株初步鉴定为腐生葡萄球茵(Staphylococcussaprophyticus),并命名为YSC.1。对菌株YSC.1的生长特性研究表明:茵株的最佳生长温度和pH分别为30℃、7.0;NaCI浓度对菌株YSC-1生长有较大的影响。菌株在20℃-40℃之间均能降解乙羧氟草醚,在30%1、pH7.0的条件下对乙羧氟草醚的降解率最高;增加乙羧氟草醚的浓度会对菌株产生毒害作用,降低其降解率;提高接种量可以加快乙羧氟草醚的降解。在乙羧氟草醚终浓度为100mg/L的工业废水经7d处理后,乙羧氟草醚的去除率达91.62%,说明菌株YSC-1在废水处理中具有很好的应用前景。

  9. Treatment of hydrocarbon-rich wastewater using oil degrading bacteria and phototrophic microorganisms in rotating biological contactor: Effect of N:P ratio

    International Nuclear Information System (INIS)

    Treatment of hydrocarbon-rich industrial wastewater in bioreactors using heterotrophic microorganisms is often associated with various operational problems. In this study, a consortium of phototrophic microorganisms and a bacterium is developed on the discs of a rotating biological contactor (RBC) for treatment of wastewater containing diesel oil. The reactor was fed with oil degrading bacterium, Burkholderia cepacia and oil tolerant phototrophic microorganisms. After biofilm formation and acclimatization to 0.6% (v/v) diesel, continuous-mode operation was initiated at 21 h hydraulic retention time (HRT). Residual diesel in the effluent was 0.003%. Advantages of this system include good total petroleum hydrocarbon (TPH) removal, no soluble carbon source requirement and good settleability of biosolids. Biofilm observations revealed the predominance of B. cepacia and cyanobacteria (Phormidium, Oscillatoria and Chroococcus). The N:P ratio affected the relative dominance of the phototrophic microorganisms and bacterial culture. This ratio was a critical factor in determining the performance efficiency of the reactor. At 21 h HRT and organic loading of 27.33 g TPH/m2 d, the N:P ratio 28.5:1 and 38:1 both yielded high and almost comparable TPH and COD removal efficiencies. This study presents a feasible technology for the treatment of hydrocarbon-rich wastewater from petrochemical industries and petroleum refineries

  10. Treatment of hydrocarbon-rich wastewater using oil degrading bacteria and phototrophic microorganisms in rotating biological contactor: Effect of N:P ratio

    Energy Technology Data Exchange (ETDEWEB)

    Chavan, Anal [Centre for Environmental Science and Engineering (CESE), Indian Institute of Technology (Bombay), Powai, Mumbai 400076 (India); Mukherji, Suparna [Centre for Environmental Science and Engineering (CESE), Indian Institute of Technology (Bombay), Powai, Mumbai 400076 (India)], E-mail: mitras@iitb.ac.in

    2008-06-15

    Treatment of hydrocarbon-rich industrial wastewater in bioreactors using heterotrophic microorganisms is often associated with various operational problems. In this study, a consortium of phototrophic microorganisms and a bacterium is developed on the discs of a rotating biological contactor (RBC) for treatment of wastewater containing diesel oil. The reactor was fed with oil degrading bacterium, Burkholderia cepacia and oil tolerant phototrophic microorganisms. After biofilm formation and acclimatization to 0.6% (v/v) diesel, continuous-mode operation was initiated at 21 h hydraulic retention time (HRT). Residual diesel in the effluent was 0.003%. Advantages of this system include good total petroleum hydrocarbon (TPH) removal, no soluble carbon source requirement and good settleability of biosolids. Biofilm observations revealed the predominance of B. cepacia and cyanobacteria (Phormidium, Oscillatoria and Chroococcus). The N:P ratio affected the relative dominance of the phototrophic microorganisms and bacterial culture. This ratio was a critical factor in determining the performance efficiency of the reactor. At 21 h HRT and organic loading of 27.33 g TPH/m{sup 2} d, the N:P ratio 28.5:1 and 38:1 both yielded high and almost comparable TPH and COD removal efficiencies. This study presents a feasible technology for the treatment of hydrocarbon-rich wastewater from petrochemical industries and petroleum refineries.

  11. H2O2-assisted photocatalysis on flower-like rutile TiO2 nanostructures: Rapid dye degradation and inactivation of bacteria

    Science.gov (United States)

    Kőrösi, László; Prato, Mirko; Scarpellini, Alice; Kovács, János; Dömötör, Dóra; Kovács, Tamás; Papp, Szilvia

    2016-03-01

    Hierarchically assembled flower-like rutile TiO2 (FLH-R-TiO2) nanostructures were successfully synthesized from TiCl4 at room temperature without the use of surfactants or templates. An initial sol-gel synthesis at room temperature allowed long-term hydrolysis and condensation of the precursors. The resulting FLH-R-TiO2 possessed relatively high crystallinity (85 wt%) and consisted of rod-shaped subunits assembling into cauliflower-like nanostructures. Hydrothermal evolution of FLH-R-TiO2 at different temperatures (150, 200 and 250 °C) was followed by means of X-ray diffraction, transmission and scanning electron microscopy. These FLH-R-TiO2 nanostructures were tested as photocatalysts under simulated daylight (full-spectrum lighting) in the degradation of methyl orange and in the inactivation of a multiresistant bacterium, Klebsiella pneumoniae. The effects of hydrothermal treatment on the structure, photocatalytic behavior and antibacterial activity of FLH-R-TiO2 are discussed.

  12. Construction of Straw Degradation Bacteria Group and Conditions Optimization of Their Highly Active Enzyme%高活性秸秆降解菌群的构建及产酶条件优化

    Institute of Scientific and Technical Information of China (English)

    昌艳萍; 耿超; 李春蕾; 武瑞兰; 薛柳青; 李红权

    2013-01-01

    The exploitation and use of cellulose should be placed before everything in this society with resource scarcity. Straw contains a lot of cellulose and lignin. It gradually becomes the focus of the renewable resources development from an agricultural waste. In order to make full use of straw resources, a mixture of cow muck, sheep droppings and soil which contains decayed leaves for material was used to set a flora with high cellulose degradation ability by limit culture method. Besides, the ability of this group of high efficiency degradation bacterium was decised by determining its activity of CMCase and filter paper activity. Then each strains of bacteria in this group was separated. What's more, physiology and biochemistry of each bacteria were analysed. The best enzyme production conditions the flora is optimized through orthogonal test. A flora with CMCase activity living up to 80 U/mL and filter paper activity is as high as 152 U/mL was achieved. The best enzyme production conditions which is using the PCS culture medium with filter paper cellulose culture medium for carbon sources, pH 5. 0,35 *C for stationary culture was achieved. It will become a new direction to screen high stable yield bacteria group for straw degradation.%纤维素的开发与利用在当今资源紧缺的社会下是当务之急,秸秆含有大量的纤维素,木质素.它从一个农业废弃物逐渐变为了再生资源开发的焦点.为了将秸秆资源充分利用起来,我们以牛粪,羊粪及含腐烂树叶土壤的混合物为材料,利用限制性培养技术,对其中能够降解纤维素的微生物进行驯化培养,并得到一组高效降解纤维素的菌群.利用CMC糖化力法和滤纸酶法测定该菌群的纤维素降解能力.对菌群进行菌种的分离,并进行生理生化试验分析各个菌株的特性.通过正交试验对该菌群的最佳产酶条件进行优化.得到的菌群CMCase酶活的高达80 U/mL,滤纸酶活高达152 U/mL.得到的最佳

  13. Explosives tester with heater

    Science.gov (United States)

    Del Eckels, Joel; Nunes, Peter J.; Simpson, Randall L.; Whipple, Richard E.; Carter, J. Chance; Reynolds, John G.

    2010-08-10

    An inspection tester system for testing for explosives. The tester includes a body and a swab unit adapted to be removeably connected to the body. At least one reagent holder and dispenser is operatively connected to the body. The reagent holder and dispenser contains an explosives detecting reagent and is positioned to deliver the explosives detecting reagent to the swab unit. A heater is operatively connected to the body and the swab unit is adapted to be operatively connected to the heater.

  14. Dynamics of explosive instability

    International Nuclear Information System (INIS)

    It was shown that in general case explosive instability dynamics should be described as four wave interaction. The main difference from three wave interaction is that this dynamics may not contain explosive instability. Besides it may by irregular. If the characteristics of one of the wave is closed to one of the interacting wave and they are connected linearly then explosive instability may be suppressed.

  15. Intermittent Explosive Disorder

    OpenAIRE

    Lut Tamam; Meliha Zengin Eroglu; Ozlem Paltaci

    2011-01-01

    Intermittent explosive disorder is an impulse control disorder characterized by the occurrence of discrete episodes of failure to resist aggressive impulses that result in violent assault or destruction of property. Though the prevalence intermittent explosive disorder has been reported to be relatively rare in frontier studies on the field, it is now common opinion that intermittent explosive disorder is far more common than previously thought especially in clinical psychiatry settings. Etio...

  16. Explosive Technology Group

    Data.gov (United States)

    Federal Laboratory Consortium — The Explosive Technology Group (ETG) provides diverse technical expertise and an agile, integrated approach to solve complex challenges for all classes of energetic...

  17. Explosive pulsed power

    CERN Document Server

    Altgilbers, Larry L; Freeman, Bruce L

    2010-01-01

    Explosive pulsed power generators are devices that either convert the chemical energy stored in explosives into electrical energy or use the shock waves generated by explosives to release energy stored in ferroelectric and ferromagnetic materials. The objective of this book is to acquaint the reader with the principles of operation of explosive generators and to provide details on how to design, build, and test three types of generators: flux compression, ferroelectric, and ferromagnetic generators, which are the most developed and the most near term for practical applications. Containing a co

  18. Steam explosion studies review

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Moon Kyu; Kim, Hee Dong

    1999-03-01

    When a cold liquid is brought into contact with a molten material with a temperature significantly higher than the liquid boiling point, an explosive interaction due to sudden fragmentation of the melt and rapid evaporation of the liquid may take place. This phenomenon is referred to as a steam explosion or vapor explosion. Depending upon the amount of the melt and the liquid involved, the mechanical energy released during a vapor explosion can be large enough to cause serious destruction. In hypothetical severe accidents which involve fuel melt down, subsequent interactions between the molten fuel and coolant may cause steam explosion. This process has been studied by many investigators in an effort to assess the likelihood of containment failure which leads to large scale release of radioactive materials to the environment. In an effort to understand the phenomenology of steam explosion, extensive studies has been performed so far. The report presents both experimental and analytical studies on steam explosion. As for the experimental studies, both small scale tests which involve usually less than 20 g of high temperature melt and medium/large scale tests which more than 1 kg of melt is used are reviewed. For the modelling part of steam explosions, mechanistic modelling as well as thermodynamic modelling is reviewed. (author)

  19. Explosions and static electricity

    DEFF Research Database (Denmark)

    Jonassen, Niels M

    1995-01-01

    The paper deals with the problem of electrostatic discharges as causes of ignition of vapor/gas and dust/gas mixtures. A series of examples of static-caused explosions will be discussed. The concepts of explosion limits, the incendiveness of various discharge types and safe voltages are explained...

  20. Steam explosion studies review

    International Nuclear Information System (INIS)

    When a cold liquid is brought into contact with a molten material with a temperature significantly higher than the liquid boiling point, an explosive interaction due to sudden fragmentation of the melt and rapid evaporation of the liquid may take place. This phenomenon is referred to as a steam explosion or vapor explosion. Depending upon the amount of the melt and the liquid involved, the mechanical energy released during a vapor explosion can be large enough to cause serious destruction. In hypothetical severe accidents which involve fuel melt down, subsequent interactions between the molten fuel and coolant may cause steam explosion. This process has been studied by many investigators in an effort to assess the likelihood of containment failure which leads to large scale release of radioactive materials to the environment. In an effort to understand the phenomenology of steam explosion, extensive studies has been performed so far. The report presents both experimental and analytical studies on steam explosion. As for the experimental studies, both small scale tests which involve usually less than 20 g of high temperature melt and medium/large scale tests which more than 1 kg of melt is used are reviewed. For the modelling part of steam explosions, mechanistic modelling as well as thermodynamic modelling is reviewed. (author)

  1. Methanotrophic bacteria.

    OpenAIRE

    Hanson, R S; Hanson, T. E.

    1996-01-01

    Methane-utilizing bacteria (methanotrophs) are a diverse group of gram-negative bacteria that are related to other members of the Proteobacteria. These bacteria are classified into three groups based on the pathways used for assimilation of formaldehyde, the major source of cell carbon, and other physiological and morphological features. The type I and type X methanotrophs are found within the gamma subdivision of the Proteobacteria and employ the ribulose monophosphate pathway for formaldehy...

  2. Research topics in explosives - a look at explosives behaviors

    International Nuclear Information System (INIS)

    The behaviors of explosives under many conditions - e.g., sensitivity to inadvertent reactions, explosion, detonation - are controlled by the chemical and physical properties of the explosive materials. Several properties are considered for a range of improvised and conventional explosives. Here I compare these properties across a wide range of explosives to develop an understanding of explosive behaviors. For improvised explosives, which are generally heterogeneous mixtures of ingredients, a range of studies is identified as needed to more fully understand their behavior and properties. For conventional explosives, which are generally comprised of crystalline explosive molecules held together with a binder, I identify key material properties that determine overall sensitivity, including the extremely safe behavior of Insensitive High Explosives, and discuss an approach to predicting the sensitivity or insensitivity of an explosive.

  3. Optically measured explosive impulse

    Science.gov (United States)

    Biss, Matthew M.; McNesby, Kevin L.

    2014-06-01

    An experimental technique is investigated to optically measure the explosive impulse produced by laboratory-scale spherical charges detonated in air. Explosive impulse has historically been calculated from temporal pressure measurements obtained via piezoelectric transducers. The presented technique instead combines schlieren flow visualization and high-speed digital imaging to optically measure explosive impulse. Prior to an explosive event, schlieren system calibration is performed using known light-ray refractions and resulting digital image intensities. Explosive charges are detonated in the test section of a schlieren system and imaged by a high-speed digital camera in pseudo-streak mode. Spatiotemporal schlieren intensity maps are converted using an Abel deconvolution, Rankine-Hugoniot jump equations, ideal gas law, triangular temperature decay profile, and Schardin's standard photometric technique to yield spatiotemporal pressure maps. Temporal integration of individual pixel pressure profiles over the positive pressure duration of the shock wave yields the explosive impulse generated for a given radial standoff. Calculated explosive impulses are shown to exhibit good agreement between optically derived values and pencil gage pressure transducers.

  4. Environmental activity of bacteria degrading pollutants

    OpenAIRE

    Moreno Forero S. C.

    2015-01-01

    Une des meilleures techniques pour décontaminer l'environnement d'éléments toxiques (comme par exemple le dibenzofuan, DBF et le 4-chlorophenol, 4CP) déposés par l'homme, à bas coûts et sans le perturber considérablement, est sans doute la biorémédiation, et particulièrement la bioaugmentation. Malheureusement, si plusieurs microorganismes ont démontré leur efficacité à dégrader les composés toxiques en conditions de laboratoire, plusieurs tentatives afin de les utiliser dans l'environnement ...

  5. Research on honeycomb structure explosives and double sided explosive cladding

    International Nuclear Information System (INIS)

    Highlights: • Honeycomb structure explosives are used to ensure the quality of charge. • Double sided explosive cladding can clad two composite plates simultaneously. • The critical thickness of explosives decreased significantly. • The energy efficiency of explosives has been significantly improved. • Experiment results can be better predicted by calculation. - Abstract: In order to resolve the current issues about the backward method of charge and low energy efficiency of explosives, honeycomb structure explosives and double sided explosive cladding were used in the present study. Honeycomb structure explosives are used to ensure the quality of charge. Double sided explosive cladding can clad two composite plates simultaneously. Honeycomb structure explosives and double sided explosive cladding, which significantly reduce the critical thickness of stable detonation of explosives, are used to increase the energy efficiency of explosives and save the amount of explosives. Emulsion explosives with the thickness of 5 mm can be stable detonation. In this paper, the experiment of double sided explosive cladding for two groups of steel of No. 45 with the thickness of 2 mm to steel of Q235 with the thickness of 16 mm and two groups of stainless steel with the thickness of 3 mm to steel of Q235 with the thickness of 16 mm were successfully investigated. Without constraints, the critical diameter of emulsion explosives is 14–16 mm. Compared to the existing explosive cladding method, the consumption of explosives for steel of No. 45 to steel of Q235 and stainless steel to steel of Q235 are reduced by 83% and 77% in the case of cladding the same number of composite plates. The explosive cladding windows and collision velocity of flyer plate were calculated before experiment. It shows that the calculation prefigures exactly the explosive cladding for steel of No. 45 to steel of Q235 and stainless steel to steel of Q235

  6. Liquid explosives detection

    Science.gov (United States)

    Burnett, Lowell J.

    1994-03-01

    A Liquid Explosives Screening System capable of scanning unopened bottles for liquid explosives has been developed. The system can be operated to detect specific explosives directly, or to verify the labeled or bar-coded contents of the container. In this system nuclear magnetic resonance (NMR) is used to interrogate the liquid. NMR produces an extremely rich data set and many parameters of the NMR response can be determined simultaneously. As a result, multiple NMR signatures may be defined for any given set of liquids, and the signature complexity then selected according to the level of threat.

  7. Use of the pre-pro part of Staphylococcus hyicus lipase as a carrier for secretion of Escherichia coli outer membrane protein A (OmpA) prevents proteolytic degradation of OmpA by cell-associated protease(s) in two different gram-positive bacteria.

    OpenAIRE

    Meens, J.; Herbort, M. (Mirco); Klein, M.; Freudl, R

    1997-01-01

    Heterologous protein secretion was studied in the gram-positive bacteria Bacillus subtilis and Staphylococcus carnosus by using the Escherichia coli outer membrane protein OmpA as a model protein. The OmpA protein was found to be translocated across the plasma membrane of both microorganisms. However, the majority of the translocated OmpA was similarly degraded in B. subtilis and S. carnosus despite the fact that the latter organism does not secrete soluble exoproteases into the culture mediu...

  8. Biodegradation of Complex Bacteria on Phenolic Derivatives in River Water

    Institute of Scientific and Technical Information of China (English)

    GUANG-HUA LU; CHAO WANG; ZHE SUN

    2009-01-01

    Objective To isolate, incubate, and identify 4-chlorophenol-degrading complex bacteria, determine the tolerance of these bacteria to phenolic derivatives and study their synergetic metabolism as well as the aboriginal microbes and co-metabolic degradation of mixed chlorophenols in river water. Methods Microbial community of complex bacteria was identified by plate culture observation techniques and Gram stain method. Bacterial growth inhibition test was used to determine the tolerance of complex bacteria to toxicants. Biodegradability of phenolic derivatives was determined by adding 4-chlorophenol-degrading bacteria in river water. Results The complex bacteria were identified as Mycopiana, Alcaligenes, Pseudvmonas, and Flavobacterium. The domesticated complex bacteria were more tolerant to phenolic derivatives than the aboriginal bacteria from Qinhuai River. The biodegradability of chlorophenols, dihydroxybenzenes and nitrophenols under various aquatic conditions was determined and compared. The complex bacteria exhibited a higher metabolic efficiency on chemicals than the aboriginal microbes, and the final removal rate of phenolic derivatives was increased at least by 55% when the complex bacteria were added into river water. The metabolic relationship between dominant mixed bacteria and river bacteria was studied. Conclusion The complex bacteria domesticated by 4-chlorophenol can grow and be metabolized to take other chlorophenols, dihydroxybenzenes and nitrophenols as the sole carbon and energy source. There is a synergetic metabolism of most compounds between the aboriginal microbes in river water and the domesticated complex bacteria. 4-chlorophenol-degrading bacteria can co-metabolize various chlorophenols in river water.

  9. Explosive Components Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The 98,000 square foot Explosive Components Facility (ECF) is a state-of-the-art facility that provides a full-range of chemical, material, and performance analysis...

  10. Parametric Explosion Spectral Model

    Energy Technology Data Exchange (ETDEWEB)

    Ford, S R; Walter, W R

    2012-01-19

    Small underground nuclear explosions need to be confidently detected, identified, and characterized in regions of the world where they have never before occurred. We develop a parametric model of the nuclear explosion seismic source spectrum derived from regional phases that is compatible with earthquake-based geometrical spreading and attenuation. Earthquake spectra are fit with a generalized version of the Brune spectrum, which is a three-parameter model that describes the long-period level, corner-frequency, and spectral slope at high-frequencies. Explosion spectra can be fit with similar spectral models whose parameters are then correlated with near-source geology and containment conditions. We observe a correlation of high gas-porosity (low-strength) with increased spectral slope. The relationship between the parametric equations and the geologic and containment conditions will assist in our physical understanding of the nuclear explosion source.

  11. Intermittent Explosive Disorder

    Directory of Open Access Journals (Sweden)

    Lut Tamam

    2011-09-01

    Full Text Available Intermittent explosive disorder is an impulse control disorder characterized by the occurrence of discrete episodes of failure to resist aggressive impulses that result in violent assault or destruction of property. Though the prevalence intermittent explosive disorder has been reported to be relatively rare in frontier studies on the field, it is now common opinion that intermittent explosive disorder is far more common than previously thought especially in clinical psychiatry settings. Etiological studies displayed the role of both psychosocial factors like childhood traumas and biological factors like dysfunctional neurotransmitter systems and genetics. In differential diagnosis of the disorder, disorders involving agression as a symptom such as alcohol and drug intoxication, antisocial and borderline personality disorders, personality changes due to general medical conditions and behavioral disorder should be considered. A combination of pharmacological and psychotherapeutic approaches are suggested in the treatment of the disorder. This article briefly reviews the historical background, diagnostic criteria, epidemiology, etiology and treatment of intermittent explosive disorder.

  12. Modeling nuclear explosion

    Science.gov (United States)

    Redd, Jeremy; Panin, Alexander

    2012-10-01

    As a result of the Nuclear Test Ban Treaty, no nuclear explosion tests have been performed by the US since 1992. This appreciably limits valuable experimental data needed for improvement of existing weapons and development of new ones, as well as for use of nuclear devices in non-military applications (such as making underground oil reservoirs or compressed air energy storages). This in turn increases the value of numerical modeling of nuclear explosions and of their effects on the environment. We develop numerical codes simulating fission chain reactions in a supercritical U and Pu core and the dynamics of the subsequent expansion of generated hot plasma in order to better understand the impact of such explosions on their surroundings. The results of our simulations (of both above ground and underground explosions) of various energy yields are presented.

  13. Shock waves & explosions

    CERN Document Server

    Sachdev, PL

    2004-01-01

    Understanding the causes and effects of explosions is important to experts in a broad range of disciplines, including the military, industrial and environmental research, aeronautic engineering, and applied mathematics. Offering an introductory review of historic research, Shock Waves and Explosions brings analytic and computational methods to a wide audience in a clear and thorough way. Beginning with an overview of the research on combustion and gas dynamics in the 1970s and 1980s, the author brings you up to date by covering modeling techniques and asymptotic and perturbative methods and ending with a chapter on computational methods.Most of the book deals with the mathematical analysis of explosions, but computational results are also included wherever they are available. Historical perspectives are provided on the advent of nonlinear science, as well as on the mathematical study of the blast wave phenomenon, both when visualized as a point explosion and when simulated as the expansion of a high-pressure ...

  14. Chemical Explosion Database

    Science.gov (United States)

    Johansson, Peder; Brachet, Nicolas

    2010-05-01

    A database containing information on chemical explosions, recorded and located by the International Data Center (IDC) of the CTBTO, should be established in the IDC prior to entry into force of the CTBT. Nearly all of the large chemical explosions occur in connection with mining activity. As a first step towards the establishment of this database, a survey of presumed mining areas where sufficiently large explosions are conducted has been done. This is dominated by the large coal mining areas like the Powder River (U.S.), Kuznetsk (Russia), Bowen (Australia) and Ekibastuz (Kazakhstan) basins. There are also several other smaller mining areas, in e.g. Scandinavia, Poland, Kazakhstan and Australia, with large enough explosions for detection. Events in the Reviewed Event Bulletin (REB) of the IDC that are located in or close to these mining areas, and which therefore are candidates for inclusion in the database, have been investigated. Comparison with a database of infrasound events has been done as many mining blasts generate strong infrasound signals and therefore also are included in the infrasound database. Currently there are 66 such REB events in 18 mining areas in the infrasound database. On a yearly basis several hundreds of events in mining areas have been recorded and included in the REB. Establishment of the database of chemical explosions requires confirmation and ground truth information from the States Parties regarding these events. For an explosion reported in the REB, the appropriate authority in whose country the explosion occurred is encouraged, on a voluntary basis, to seek out information on the explosion and communicate this information to the IDC.

  15. Modelling of gas explosions

    OpenAIRE

    Vågsæther, Knut

    2010-01-01

    The content of this thesis is a study of gas explosions in complex geometries and presentation and validation of a method for simulating flame acceleration and deflagration to detonation transition. The thesis includes a description of the mechanisms of flame acceleration and DDT that need to be modeled when simulating all stages of gas explosions. These mechanisms are flame acceleration due to instabilities that occur in fluid flow and reactive systems, shock propagation, deflagration to det...

  16. Big bacteria

    DEFF Research Database (Denmark)

    Schulz, HN; Jørgensen, BB

    2001-01-01

    A small number of prokaryotic species have a unique physiology or ecology related to their development of unusually large size. The biomass of bacteria varies over more than 10 orders of magnitude, from the 0.2 mum wide nanobacteria to the largest cells of the colorless sulfur bacteria......, Thiomargarita namibiensis, with a diameter of 750 mum. All bacteria, including those that swim around in the environment, obtain their food molecules by molecular diffusion. Only the fastest and largest swimmers known, Thiovulum majus, are able to significantly increase their food supply by motility and by...... actively creating an advective flow through the entire population. Diffusion limitation generally restricts the maximal size of prokaryotic cells and provides a selective advantage for mum-sized cells at the normally low substrate concentrations in the environment. The largest heterotrophic bacteria, the...

  17. Anaerobic bacteria

    Science.gov (United States)

    Brook I, Goldstein EJ. Diseases caused by non-spore forming anaerobic bacteria. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 297. Stedman's Online ...

  18. Keratinolytic activity of cutaneous and oral bacteria.

    OpenAIRE

    Mikx, F H; De Jong, M H

    1987-01-01

    A test was developed to measure the keratinolytic activity of cutaneous and oral bacteria. Keratin, labeled with fluorescein isothiocyanate, was used in a phosphate buffer (pH 7.2) with 1 mM dithiothreitol. The degradation of keratin was estimated by measuring the fluorescence of the degradation products in the supernatant of the reaction mixtures in a luminescence spectrometer. Several oral and cutaneous bacteria were investigated: Bacteroides gingivalis, Bacteroides intermedius, Treponema d...

  19. Peaceful nuclear explosions

    International Nuclear Information System (INIS)

    This paper reports on studies of the results of U.S. programs for the application of peaceful nuclear explosions which make it clear that they are not particularly attractive to the United States at this time, and that there is no significant indication that they will have commercial utilization by 1990. Although one must make allowances for different situations in other countries, there do not appear to be any obvious technical or economic reasons why this somewhat negative conclusion should not apply to virtually all other nations as well. This does not constitute an argument against R and D on possible peaceful uses, given the many technical unknowns and economic uncertainties. It does, however, strongly suggest that if continued testing of peaceful nuclear explosions represents a substantial interference to desirable arms control or disarmament objectives, the potential benefits from peaceful nuclear explosions would not appear to be sufficient to permit their testing to stand in the way. Specifically, it is hard to see why concern about peaceful nuclear explosions should interfere with negotiations toward a comprehensive test ban treaty. At the very minimum, a 10-year world moratorium on testing or use of peaceful nuclear explosions would seem to be a modest price to pay for the significant progress toward arms control and detente which a comprehensive test ban treaty could represent

  20. R-22 vapor explosions

    International Nuclear Information System (INIS)

    Previous experimental and theoretical studies of R-22 vapor explosions are reviewed. Results from two experimental investigations of vapor explosions in a medium scale R-22/water system are reported. Measurements following the drop of an unrestrained mass of R-22 into a water tank demonstrated the existence of two types of interaction behavior. Release of a constrained mass of R-22 beneath the surface of a water tank improved the visual resolution of the system thus allowing identification of two interaction mechansims: at low water temperatures, R-22/water contact would produce immediate violent boiling; at high water temperatures a vapor film formed around its R-22 as it was released, explosions were generated by a surface wave which initiated at a single location and propagated along the vapor film as a shock wave. A new vapor explosion model is proposed, it suggests explosions are the result of a sequence of three independent steps: an initial mixing phase, a trigger and growth phase, and a mature phase where a propagating shock wave accelerates the two liquids into a collapsing vapor layer causing a high velocity impact which finely fragments and intermixes the two liquids

  1. 78 FR 64246 - Commerce in Explosives; List of Explosives Materials

    Science.gov (United States)

    2013-10-28

    ... supersedes the List of Explosives Materials dated September 20, 2012 (Docket No. ATF 47N, 77 FR 58410.... Tetrazene [tetracene, tetrazine, 1(5-tetrazolyl)-4-guanyl tetrazene hydrate]. Tetrazole explosives....

  2. Bacterial degradation of bile salts

    OpenAIRE

    Philipp, Bodo

    2011-01-01

    Bile salts are surface-active steroid compounds. Their main physiological function is aiding the digestion of lipophilic nutrients in intestinal tracts of vertebrates. Many bacteria are capable of transforming and degrading bile salts in the digestive tract and in the environment. Bacterial bile salt transformation and degradation is of high ecological relevance and also essential for the biotechnological production of steroid drugs. While biotechnological aspects have been reviewed many time...

  3. Portable raman explosives detection

    Energy Technology Data Exchange (ETDEWEB)

    Moore, David Steven [Los Alamos National Laboratory; Scharff, Robert J [Los Alamos National Laboratory

    2008-01-01

    Recent advances in portable Raman instruments have dramatically increased their application to emergency response and forensics, as well as homeland defense. This paper reviews the relevant attributes and disadvantages of portable Raman spectroscopy, both essentially and instrumentally, to the task of explosives detection in the field.

  4. Propagation in thermal explosions

    International Nuclear Information System (INIS)

    In a number a small scale experiments the propagation phenomena in thermal explosions caused by contact of a molten metal with water were studied. To investigate the rapid vapor-blanket collapse a small amount of molten tin (800 deg C) was poured on to a crucible under water at decreased pressure. After pressurization to 1 bar the pressure rise in the vessel was measured and the occurring events were observed by cinephotography (8000ps-1). The experiment showed that explosion propagation by blanket collapse is energetically possible. Similar experiments were performed with a larger interacting surface in a through shaped and in a think tank shaped arrangement, which demonstrated that propagation actually occured; the propagation velocity could be estimated to about 5-103cm s-1. The findings favour the interpretation that the explosion is driven by fragmentation rather than by super heat. Fragmentation or mixing can occur through self-driven collapse and possibly by penetration of coolant jets formed by the collapse in the blanket. In a continuously propagation explosion, Taylor and Kelvin-Helmholtz instabilities may take part in the mixing process

  5. Bacteria in Crude Oil Survived Autoclaving and Stimulated Differentially by Exogenous Bacteria

    OpenAIRE

    Gong, Xiao-Cui; Liu, Ze-Shen; Guo, Peng; Chi, Chang-Qiao; Chen, Jian; Wang, Xing-Biao; Tang, Yue-Qin; Wu, Xiao-Lei; Liu, Chun-Zhong

    2012-01-01

    Autoclaving of crude oil is often used to evaluate the hydrocarbon-degrading abilities of bacteria. This may be potentially useful for bioaugmentation and microbial enhanced oil recovery (MEOR). However, it is not entirely clear if “endogenous” bacteria (e.g., spores) in/on crude oil survive the autoclaving process, or influence subsequent evaluation of the hydrocarbon-degradation abilities of the “exogenous” bacterial strains. To test this, we inoculated autoclaved crude oil medium with six ...

  6. Electromagnetic pulse from nuclear explosions

    International Nuclear Information System (INIS)

    The effect of the electromagnetic pulse (EMP) accompanying a nuclear explosion on electronic equipment is presented largely in the form of examples of damage to equipment during nuclear test explosions. The range of such effects is related to the height above the ground at which the explosion takes place. Electric fields and currents generated by EMP in a number of tests, as measured or estimated at various distances are cited. Underground explosions only give EMP over short distances, less than 30 km, while the EMP from conventional explosions is weak and has no significance for electronic equipment. (JIW)

  7. Explosive bulk charge

    Science.gov (United States)

    Miller, Jacob Lee

    2015-04-21

    An explosive bulk charge, including: a first contact surface configured to be selectively disposed substantially adjacent to a structure or material; a second end surface configured to selectively receive a detonator; and a curvilinear side surface joining the first contact surface and the second end surface. The first contact surface, the second end surface, and the curvilinear side surface form a bi-truncated hemispherical structure. The first contact surface, the second end surface, and the curvilinear side surface are formed from an explosive material. Optionally, the first contact surface and the second end surface each have a substantially circular shape. Optionally, the first contact surface and the second end surface consist of planar structures that are aligned substantially parallel or slightly tilted with respect to one another. The curvilinear side surface has one of a smooth curved geometry, an elliptical geometry, and a parabolic geometry.

  8. Pentaerythritol tetranitrate (PETN) profiling in post-explosion residues to constitute evidence of crime-scene presence.

    Science.gov (United States)

    Brust, Hanneke; van Asten, Arian; Koeberg, Mattijs; van der Heijden, Antoine; Kuijpers, Chris-Jan; Schoenmakers, Peter

    2013-07-10

    Pentaerythritol tetranitrate (PETN) and its degradation products are analyzed to discriminate between residues originating from PETN explosions and residues obtained under other circumstances, such as natural degradation on textile, or after handling intact PETN. The degradation products observed in post-explosion samples were identified using liquid chromatography-mass spectrometry as the less-nitrated analogues of PETN: pentaerythritol trinitrate (PETriN), pentaerythritol dinitrate (PEDiN) and pentaerythritol mononitrate (PEMN). Significant levels of these degradation products were observed in post-explosion samples, whereas only very low levels were detected in a variety of intact PETN samples and naturally degraded PETN. No significant degradation was observed after 12 weeks of storage at room temperature and the influence of high relative humidity (90%) was found to be small. Natural degradation was accelerated by storage of small amounts of PETN on different types of textile, resembling the clothing of a suspect, at elevated temperature (333K). This resulted in significant levels of PETN degradation products, but the relative amounts remained much lower than in post-explosion PETN. For PETriN the peak area relative to PETN was 0.014 (SD=0.0051) and 0.39 (SD=0.19) respectively. Based on the peak areas of PETriN, PEDiN and PEMN relative to PETN, it was possible to fully distinguish the post-explosion profiles from the profiles obtained from intact PETN or after (accelerated) natural degradation. Although more data are required to accurately assess the strength of the evidence, this work illustrates that PETN profiling may yield valuable evidence when investigating a possible link between a suspect and post-explosion PETN found on a crime scene. Due to the substantial variation in the degradation pattern between explosion experiments and even between sampling positions in one experiment, the method is not able to distinguish different PETN explosion events. PMID

  9. Phytoremediation of explosives

    Czech Academy of Sciences Publication Activity Database

    Vaněk, Tomáš; Podlipná, Radka; Hebner, A.; Vavříková, Zuzana; Gerth, A.; Thomas, H.; Smrček, S.

    Krakow : -, 2005, s. 55. [Advanced Research Workshop. Viable methods of soil and water pollution monitoring, protection and remediation: development and use. Krakow (PL), 26.06.2005-01.07.2005] R&D Projects: GA MŠk(CZ) 1P05OC042; GA MŠk(CZ) ME 493 Institutional research plan: CEZ:AV0Z40550506 Keywords : explosives * TNT * phytoremediation Subject RIV: DK - Soil Contamination ; De-contamination incl. Pesticides

  10. High explosive compound

    Science.gov (United States)

    Crawford, Theodore C.

    1976-01-01

    1. A low detonation velocity explosive consisting essentially of a particulate mixture of ortho-boric acid and trinitrotoluene, said mixture containing from about 25 percent to about 65 percent by weight of ortho-boric acid, said ortho-boric acid comprised of from 60 percent to 90 percent of spherical particles having a mean particle size of about 275 microns and 10 percent to 40 percent of spherical particles having a particle size less than about 44 microns.

  11. Explosions in November

    OpenAIRE

    Steinitz, Richard

    2011-01-01

    Explosions in November tells the story of one of Europe’s leading cultural institutions, Huddersfield Contemporary Music Festival (hcmf), through the eyes of its founder and former artistic director, Professor Richard Steinitz. From its modest beginnings in 1978, when winter fog nearly sabotaged the inaugural programme, to today’s internationally renowned event, hcmf has been a pioneering champion of the best in contemporary music. Commissioning new work, reappraising existing legacies an...

  12. Phytoremediation of explosives

    Czech Academy of Sciences Publication Activity Database

    Vaněk, Tomáš; Nepovím, Aleš; Hebner, A.; Soudek, Petr; Gerth, A.; Thomas, H.; Smrček, S.

    Pisa: CNR Research Campus, 2005, s. 137. [Phytotechnologies to promote sustainable land use and improve food safety . Scientific Workshop and Management Committee Meeting /1./. Pisa (IT), 14.06.2005-16.06.2005] R&D Projects: GA MŠk(CZ) 1P05OC042; GA MŠk(CZ) ME 493 Institutional research plan: CEZ:AV0Z40550506 Keywords : phytoremediation * explosives Subject RIV: DK - Soil Contamination ; De-contamination incl. Pesticides

  13. Explosives signatures and analysis

    Science.gov (United States)

    Fountain, Augustus Way, III; Oyler, Jonathan M.; Ostazeski, Stanley A.

    2008-04-01

    The challenge of sampling explosive materials for various high threat military and civilian operational scenarios requires the community to identify and exploit other chemical compounds within the mixtures that may be available to support stand-off detection techniques. While limited surface and vapor phase characterization of IEDs exist, they are insufficient to guide the future development and evaluation of field deployable explosives detection (proximity and standoff) capabilities. ECBC has conducted a limited investigation of three artillery ammunition types to determine what chemical vapors, if any, are available for sensing; the relative composition of the vapors which includes the more volatile compounds in munitions, i.e., plastersizers and binders; and the sensitivity needed detect these vapors at stand-off. Also in partnership with MIT-Lincoln Laboratory, we performed a background measurement campaign at the National Training Center to determine the baseline ambient amounts and variability of nitrates and nitro-ester compounds as vapors, particulates, and on surfaces; as well as other chemical compounds related to non-energetic explosive additives. Environmental persistence studies in contexts relevant to counter-IED sensing operations, such as surface residues, are still necessary.

  14. Characteristic Research on Evaporated Explosive Film

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The evaporation source of evaporated explosive was designed and improved based on the inherent specialties of explosive. The compatibility of explosives and addition agent with evaporation vessels was analyzed. The influence of substrate temperature on explosive was analyzed, the control method of substrate temperature was suggested. The influences of evaporation rate on formation of explosive film and mixed explosive film were confirmed. Optimum evaporation rate for evaporation explosive and the better method for evaporating mixed explosive were presented. The necessary characteristics of the evaporated explosive film were obtained by the research of the differences between the evaporated explosive and other materials.

  15. Bacteria and bioremediation of marine oil spills

    International Nuclear Information System (INIS)

    Virtually all marine ecosystems harbor indigenous hydrocarbon-degrading bacteria. These hydrocarbon degraders comprise less than one percent of the bacterial community in unpolluted environments, but generally increase to one to ten percent following petroleum contamination. Various hydrocarbons are degraded by these microorganisms at different rates, so there is an evolution in the residual hydrocarbon mixture, and some hydrocarbons and asphaltic petroleum hydrocarbons remain undegraded. Fortunately, these persistent petroleum pollutants are, for the most part, insoluble or are bound to solids; hence they are not biologically available and therefore not toxic to marine organisms. Carbon dioxide, water, and cellular biomass produced by the microorganisms from the degradable hydrocarbons may be consumed by detrital feeders and comprise the end products of the natural biological degradation process. Bioremediation attempts to accelerate the natural hydrocarbon degradation rates by overcoming factors that limit bacterial hydrocarbon degrading activities

  16. Rumen bacteria

    International Nuclear Information System (INIS)

    The rumen is the most extensively studied gut community and is characterized by its high population density, wide diversity and complexity of interactions. This complex, mixed microbial culture is comprised of prokaryote organisms including methane-producing archaebacteria, eukaryote organisms, such as ciliate and flagellate protozoa, anaerobic phycomycete fungi and bacteriophage. Bacteria are predominant (up to 1011 viable cells per g comprising 200 species) but a variety of ciliate protozoa occur widely (104-106/g distributed over 25 genera). The anaerobic fungi are also widely distributed (zoospore population densities of 102-104/g distributed over 5 genera). The occurrence of bacteriophage is well documented (107-109 particles/g). This section focuses primarily on the widely used methods for the cultivation and the enumeration of rumen microbes, especially bacteria, which grow under anaerobic conditions. Methods that can be used to measure hydrolytic enzymes (cellulases, xylanases, amylases and proteinases) are also described, along with cell harvesting and fractionation procedures. Brief reference is also made to fungi and protozoa, but detailed explanations for culturing and enumerating these microbes is presented in Chapters 2.4 and 2.5

  17. Bacteria Provide Cleanup of Oil Spills, Wastewater

    Science.gov (United States)

    2010-01-01

    Through Small Business Innovation Research (SBIR) contracts with Marshall Space Flight Center, Micro-Bac International Inc., of Round Rock, Texas, developed a phototrophic cell for water purification in space. Inside the cell: millions of photosynthetic bacteria. Micro-Bac proceeded to commercialize the bacterial formulation it developed for the SBIR project. The formulation is now used for the remediation of wastewater systems and waste from livestock farms and food manufacturers. Strains of the SBIR-derived bacteria also feature in microbial solutions that treat environmentally damaging oil spills, such as that resulting from the catastrophic 2010 Deepwater Horizon oil rig explosion in the Gulf of Mexico.

  18. Anaerobic Metabolism and Bioremediation of Explosives-Contaminated Soil

    Science.gov (United States)

    Boopathy, Raj

    Nitroaromatic compounds pollute soil, water, and food via use of pesticides, plastics, pharmaceuticals, landfill dumping of industrial wastes, and the military use of explosives. Biotransformation of trinitrotoluene and other nitroaromatics by aerobic bacteria in the laboratory has been frequently reported, but the anaerobic bacterial metabolism of nitroaromatics has not been studied as extensively perhaps due to the difficulty in working with anaerobic cultures and the slow growth of anaerobes. Sulfate-reducing and methanogenic bacteria can metabolize nitroaromatic compounds under anaerobic conditions if appropriate electron donors and electron acceptors are present in the environment.

  19. Degradation of Ochratoxin A by Brevibacterium Species

    OpenAIRE

    Rodriguez, Héctor; Reverón, Inés; Doria, Francesca; Costantini, Antonella; Rivas, Blanca de las; Muñoz, Rosario; García-Moruno, Emilia

    2011-01-01

    The ability to degrade ochratoxin A was studied in different bacteria with a well-known capacity to transform aromatic compounds. Strains belonging to Rhodococcus, Pseudomonas, and Brevibacterium genera were grown in liquid synthetic culture medium containing ochratoxin A. Brevibacterium spp. strains showed 100% degradation of ochratoxin A.Ochratoxin ¿ was detected and identified by high-performance liquid chromatographymass spectrometry (HPLC-MS) as a degradation product in the cellfree supe...

  20. Gas explosions in process pipes

    OpenAIRE

    Kristoffersen, Kjetil

    2004-01-01

    In this thesis, gas explosions inside pipes are considered. Laboratory experiments and numerical simulations are the basis of the thesis. The target of the work was to study gas explosions in pipes and to develop numer- ical models that could predict accidental gas explosions inside pipes. Experiments were performed in circular steel and plexiglass pipes. The steel pipes have an inner diameter of 22.3 mm and lengths of 1, 2, 5 and 11 m. The plexiglass pipe has an inner diame...

  1. The thermodynamics of thermal explosions

    International Nuclear Information System (INIS)

    Thermal explosions can occur when a hot liquid mixes with a cooler, volatile liquid. Measured explosion efficiencies do not exceed two or three percent, but simple thermodynamic analysis predicts twenty or thirty percent. The difference is crucial in some nuclear reactor safety problems. The mechanisms thought to operate in thermal explosions are considered, and an alternative thermodynamic approach proposed, which takes account of certain irreversibilities in the process, and predicts much lower efficiencies. (author)

  2. PROBABILISTIC MODELING OF EXPLOSIVE LOADING

    OpenAIRE

    Mkrtychev Oleg Vartanovich; Dorozhinskiy Vladimir Bogdanovich

    2012-01-01

    According to existing design standards, explosive loading represents a special type of loading. Explosive loading is, in most cases, local in nature, although it can exceed the loads for which buildings are designed by a dozen of times. The analysis of terrorist attacks with explosives employed demonstrates that charges have a great power and, consequently, a substantial shock wave pressure. Blast effects are predictable with a certain probability. Therefore, we cannot discuss ...

  3. Explosive hydrogen burning

    International Nuclear Information System (INIS)

    Although an impressive quantity of work has been devoted to understanding nucleosynthesis during explosive hydrogen burning, much work remain to be done. Reactions which occur in novae, x-ray bursts, and supernovae are discussed. Much attention is given to the reactions of hot CNO cycles and of reactions in the rp-process. The many reactions described in this review are not all of the reactions which may be of interest to nuclear physicists, although the rates of those reactions not discussed are essentially unknown. 123 refs., 9 figs

  4. Wire explosion in water

    Czech Academy of Sciences Publication Activity Database

    Prukner, Václav; Koláček, Karel; Schmidt, Jiří; Frolov, Oleksandr; Štraus, Jaroslav

    Praha, 2007 - (Schmidt, J.; Simek, M.; Pekarek, S.; Prukner, V.). s. 145-145 ISBN 978-80-87026-00-7. [XXVIII International conference on phenomena in ionized gases ICPIG’07/28th./. 15.7.2007-20.7.2007, Prague] R&D Projects: GA ČR GA202/06/1324; GA AV ČR KJB100430702; GA MŠk 1P04LA235 Institutional research plan: CEZ:AV0Z20430508 Keywords : Wire explosion * x-ray * laser * plasma Subject RIV: BL - Plasma and Gas Discharge Physics

  5. Wire explosion in water

    Czech Academy of Sciences Publication Activity Database

    Prukner, Václav; Koláček, Karel; Schmidt, Jiří; Frolov, Oleksandr; Štraus, Jaroslav

    Prague: Institute of Plasma Physics AS CR,v.v.i, 2008 - (Schmidt, J.; Šimek, M.; Pekárek, S.; Prukner, V.), s. 1279-1281. (ICPIG. 28). ISBN 978-80-87026-01-4. [XXVIII International conference on phenomena in ionized gases ICPIG’07. Prague (CZ), 15.07.2007-20.07.2007] R&D Projects: GA ČR GA202/06/1324; GA AV ČR KJB100430702; GA MŠk 1P04LA235 Institutional research plan: CEZ:AV0Z20430508 Keywords : Wire explosion * x-ray * laser * plasma Subject RIV: BL - Plasma and Gas Discharge Physics

  6. Spectral Anlysis on Explosive Percolation

    CERN Document Server

    Chung, Ning Ning; Lai, Choy Heng

    2013-01-01

    We study the spectral properties of the process of explosive percolation. In particular, we explore how the maximum eigenvalue of the adjacency matrix of a network which governs the spreading efficiency evolves as the density of connection increases. Interestingly, for networks with connectivity that grow in an explosive way, information spreading and mass transport are found to be carried out inefficiently. In the conventional explosive percolation models that we studied, the sudden emergences of large-scale connectivity are found to come with relatively lowered efficiency of spreading. Nevertheless, the spreading efficiency of the explosive model can be increased by introducing heterogeneous structures into the networks.

  7. How Bacteria Turn Fiber into Food

    OpenAIRE

    Martens, Eric C.; Lowe, Elisabeth C.; Chiang, Herbert; Nicholas A Pudlo; Wu, Meng; McNulty, Nathan P.; Abbott, D Wade; Henrissat, Bernard; Gilbert, Harry J.; Bolam, David N.; Jeffrey I Gordon

    2011-01-01

    Symbiotic bacteria inhabiting the human gut have evolved under intense pressure to utilize complex carbohydrates, primarily plant cell wall glycans in our diets. These polysaccharides are not digested by human enzymes, but are processed to absorbable short chain fatty acids by gut bacteria. The Bacteroidetes, one of two dominant bacterial phyla in the adult gut, possess broad glycan-degrading abilities. These species use a series of membrane protein complexes, termed Sus-like systems, for cat...

  8. Controlled by Distant Explosions

    Science.gov (United States)

    2007-03-01

    VLT Automatically Takes Detailed Spectra of Gamma-Ray Burst Afterglows Only Minutes After Discovery A time-series of high-resolution spectra in the optical and ultraviolet has twice been obtained just a few minutes after the detection of a gamma-ray bust explosion in a distant galaxy. The international team of astronomers responsible for these observations derived new conclusive evidence about the nature of the surroundings of these powerful explosions linked to the death of massive stars. At 11:08 pm on 17 April 2006, an alarm rang in the Control Room of ESO's Very Large Telescope on Paranal, Chile. Fortunately, it did not announce any catastrophe on the mountain, nor with one of the world's largest telescopes. Instead, it signalled the doom of a massive star, 9.3 billion light-years away, whose final scream of agony - a powerful burst of gamma rays - had been recorded by the Swift satellite only two minutes earlier. The alarm was triggered by the activation of the VLT Rapid Response Mode, a novel system that allows for robotic observations without any human intervention, except for the alignment of the spectrograph slit. ESO PR Photo 17a/07 ESO PR Photo 17a/07 Triggered by an Explosion Starting less than 10 minutes after the Swift detection, a series of spectra of increasing integration times (3, 5, 10, 20, 40 and 80 minutes) were taken with the Ultraviolet and Visual Echelle Spectrograph (UVES), mounted on Kueyen, the second Unit Telescope of the VLT. "With the Rapid Response Mode, the VLT is directly controlled by a distant explosion," said ESO astronomer Paul Vreeswijk, who requested the observations and is lead-author of the paper reporting the results. "All I really had to do, once I was informed of the gamma-ray burst detection, was to phone the staff astronomers at the Paranal Observatory, Stefano Bagnulo and Stan Stefl, to check that everything was fine." The first spectrum of this time series was the quickest ever taken of a gamma-ray burst afterglow

  9. Explosion proof device

    International Nuclear Information System (INIS)

    A chamber for carrying in/out equipments of a nuclear facility building has a shutter capable of stopping at a predetermined position and an air curtain disposed at an opening formed upon stopping of the shutter. An openable/closable partition comprises a glass door as a rupture disk. The shutter is closed as a partition for the first and the second chambers for carrying in/out equipments to divide a radiation area. The shutter is stopped near the upper end of the air curtain by a limit switch, and the air curtain is driven at the opening portion from the lower end of the shutter to the floor of the building. Since operators can freely pass the opening from the lower end of the shutter to the floor of the building, and the opening area is ensured, even if missiles are rushed from the outside breaking through the shutter to ignite loaded burnable materials, acceleration of flames is moderated to prevent explosion. Since the glass door is made of the rupture disk and broken, even if burnable materials loaded on the missiles from the outside are burnt, no explosion is caused. (N.H.)

  10. Tenderizing Meat with Explosives

    Science.gov (United States)

    Gustavson, Paul K.; Lee, Richard J.; Chambers, George P.; Solomon, Morse B.; Berry, Brad W.

    2001-06-01

    Investigators at the Food Technology and Safety Laboratory have had success tenderizing meat by explosively shock loading samples submerged in water. This technique, referred to as the Hydrodynamic Pressure (HDP) Process, is being developed to improve the efficiency and reproducibility of the beef tenderization processing over conventional aging techniques. Once optimized, the process should overcome variability in tenderization currently plaguing the beef industry. Additional benefits include marketing lower quality grades of meat, which have not been commercially viable due to a low propensity to tenderization. The simplest and most successful arrangement of these tests has meat samples (50 to 75 mm thick) placed on a steel plate at the bottom of a plastic water vessel. Reported here are tests which were instrumented by Indian Head investigators. Carbon-composite resistor-gauges were used to quantify the shock profile delivered to the surface of the meat. PVDF and resistor gauges (used later in lieu of PVDF) provided data on the pressure-time history at the meat/steel interface. Resulting changes in tenderization were correlated with increasing shock duration, which were provided by various explosives.

  11. Peaceful nuclear explosions

    International Nuclear Information System (INIS)

    Article V of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) specifies that the potential benefits of peaceful applications of nuclear explosions be made available to non-nuclear weapon states party to the Treaty 'under appropriate international observation and through appropriate international procedures'. The International Atomic Energy Agency's responsibility and technical competence in this respect have been recognized by its Board of Governors, the Agency's General Conference and the United Nations' General Assembly. Since 1968 when the United Nations Conference of Non-Nuclear Weapon States also recommended that the Agency initiate the necessary studies in the peaceful nuclear explosions (PNE) field, the Agency has taken the following steps: 1. The exchange of scientific and technical information has been facilitated by circulating information on the status of the technology and through the Agency's International Nuclear Information System. A bibliography of PNE-related literature was published in 1970. 2. In 1972, guidelines for 'the international observation of PNE under the provisions of NPT and analogous provisions in other international agreements' were developed and approved by the Board of Governors. These guidelines defined the basic purpose of international observation as being to verify that in the course of conducting a PNE project the intent and letter of Articles I and II of the NPT are not violated. 3. In 1974, an advisory group developed 'Procedures for the Agency to Use in Responding to Requests for PNE-Related Services'. These procedures have also been approved by the Board of Governors. 4. The Agency has convened a series of technical meetings which reviewed the 'state-of-the- art'. These meetings were convened in 1970, 1971, 1972 and in January 1975. The Fourth Technical Committee was held in Vienna from 20-24 January 1975 under the chairmanship of Dr. Allen Wilson of Australia with Experts from: Australia, France, Federal

  12. Reductive degradation of the new explosive material FOX-7

    Czech Academy of Sciences Publication Activity Database

    Šimková, Ludmila; Klíma, Jiří; Urban, Jiří; Ludvík, Jiří

    Herceg Novi: Materials Research Society of Serbia , 2012. s. 86. [Annual Conference YUCOMAT 2012 /14./. 03.09.2012-07.09.2012, Herceg Novi] R&D Projects: GA ČR GAP206/11/0727 Institutional support: RVO:61388955 Keywords : FOX-7 * electrochemistry

  13. 一株降解芘的苍白杆菌的分离、鉴定及性能表征%Isolation, identification and characteristics of pyrene degrading bacteria Ochrobactrum sp.

    Institute of Scientific and Technical Information of China (English)

    谢文娟; 林爱军; 杨晓进; 王凤花; SHIM Hojae

    2011-01-01

    A pyrene-degrading bacterium strain named PW was isolated from the soils contaminated with polycyclic aromatic hydrocarbons (PAHs) in Beijing Coking Plant using an enrichment culture. It was identified according to its morphology and molecular biology analysis. This bacterium belongs to the strain Ochrobactrum sp. This strain was domesticated for a period of time by a large dose method, and then shake flask experiments were used to study the influence of environmental conditions on the degradation extent of pyrene. The results showed that after domestication the degradation extent increased from 62. 3% to 92. 7% on the 5th day. The bacterium strain PW could degrade pyrene at temperatures ranging from 20 to 40 ℃, and the degradation extent at 30 ℃ was the highest. The degradation extents were above 45% in cultural mediums at a wide range of pH from 5 to 10. The results also indicated that the pyrene degradation could be affected by salt concentration and the degradation effects were better when the mass fraction of NaCl in the culture medium was less than 3%. Further study showed that the strain PW could was resistant to high concentrations of some heavy metal ions.%采用富集培养的方法从北京焦化厂多环芳烃(PAHs)污染土壤中筛选到一株高效降解芘的微生物,命名为PW,分子生物学等手段鉴定此菌株属于苍白杆菌属(Ochrobactrum sp.).经一次性大剂量方法对此菌株进行驯化后,考察了摇瓶条件下环境因素对此菌株降解芘效率的影响.结果表明,驯化培养使得菌株5d内对0.5mmol/L芘的降解率由62.3%提高到92.7%.此外,该菌株的环境耐受性好,在环境温度为20 ̄40℃下该菌株对芘均具有一定的降解能力,30℃培养时降解效果最好;在pH为5~10的培养基中,PW对芘的降解率均在45%以上;当盐度小于3%时,此菌株对芘降解率在60%以上;同时菌株PW还可耐受一定浓度的重金属.

  14. Kaliski's explosive driven fusion experiments

    International Nuclear Information System (INIS)

    An experiment performed by a group in Poland on the production of DD fusion neutrons by purely explosive means is discussed. A method for multiplying shock velocities ordinarily available from high explosives by a factor of ten is described, and its application to DD fusion experiments is discussed

  15. Lidar Detection of Explosives Traces

    OpenAIRE

    Bobrovnikov Sergei M.; Gorlov Evgeny V.; Zharkov Victor I.; Panchenko Yury N.

    2016-01-01

    The possibility of remote detection of traces of explosives using laser fragmentation/laser-induced fluorescence (LF/LIF) is studied. Experimental data on the remote visualization of traces of trinitrotoluene (TNT), hexogen (RDX), trotyl-hexogen (Comp B), octogen (HMX), and tetryl with a scanning lidar detector of traces of nitrogen-containing explosives at a distance of 5 m are presented.

  16. Chryseobacterium indologenes, novel mannanase-producing bacteria

    Directory of Open Access Journals (Sweden)

    Surachai Rattanasuk

    2009-10-01

    Full Text Available Mannanase is a mannan degrading enzyme which is produced by microorganisms, including bacteria. This enzyme can be used in many industrial processes as well as for improving the quality of animal feeds. The aim of the present study was toscreen and characterize the mannanase-producing bacteria. Two genera of bacteria were isolated from Thai soil samples,fermented coconut, and fertilizer. Screening was carried out on agar plates containing mannan stained with iodine solution.The bacteria were identified by partial 16S rRNA gene sequence, biochemical test and morphology, respectively. The mannanase activity was determined by zymogram and DNS method. Two strains of bacteria with mannanase activity were identified as Bacillus and Chryseobacterium. This is the first report of mannanase-producing Chryseobacterium.

  17. Nucleosynthesis in stellar explosions

    Energy Technology Data Exchange (ETDEWEB)

    Woosley, S.E.; Axelrod, T.S.; Weaver, T.A.

    1983-01-01

    The final evolution and explosion of stars from 10 M/sub solar/ to 10/sup 6/ M/sub solar/ are reviewed with emphasis on factors affecting the expected nucleosynthesis. We order our paper in a sequence of decreasing mass. If, as many suspect, the stellar birth function was peaked towards larger masses at earlier times (see e.g., Silk 1977; but also see Palla, Salpeter, and Stahler 1983), this sequence of masses might also be regarded as a temporal sequence. At each stage of Galactic chemical evolution stars form from the ashes of preceding generations which typically had greater mass. A wide variety of Type I supernova models, most based upon accreting white dwarf stars, are also explored using the expected light curves, spectra, and nucleosynthesis as diagnostics. No clearly favored Type I model emerges that is capable of simultaneously satisfying all three constraints.

  18. Mixing in explosions

    Energy Technology Data Exchange (ETDEWEB)

    Kuhl, A.L.

    1993-12-01

    Explosions always contain embedded turbulent mixing regions, for example: boundary layers, shear layers, wall jets, and unstable interfaces. Described here is one particular example of the latter, namely, the turbulent mixing occurring in the fireball of an HE-driven blast wave. The evolution of the turbulent mixing was studied via two-dimensional numerical simulations of the convective mixing processes on an adaptive mesh. Vorticity was generated on the fireball interface by baroclinic effects. The interface was unstable, and rapidly evolved into a turbulent mixing layer. Four phases of mixing were observed: (1) a strong blast wave phase; (2) and implosion phase; (3) a reshocking phase; and (4) an asymptotic mixing phase. The flowfield was azimuthally averaged to evaluate the mean and r.m.s. fluctuation profiles across the mixing layer. The vorticity decayed due to a cascade process. This caused the corresponding enstrophy parameter to increase linearly with time -- in agreement with homogeneous turbulence calculations of G.K. Batchelor.

  19. Nucleosynthesis in stellar explosions

    International Nuclear Information System (INIS)

    The final evolution and explosion of stars from 10 M/sub solar/ to 106 M/sub solar/ are reviewed with emphasis on factors affecting the expected nucleosynthesis. We order our paper in a sequence of decreasing mass. If, as many suspect, the stellar birth function was peaked towards larger masses at earlier times (see e.g., Silk 1977; but also see Palla, Salpeter, and Stahler 1983), this sequence of masses might also be regarded as a temporal sequence. At each stage of Galactic chemical evolution stars form from the ashes of preceding generations which typically had greater mass. A wide variety of Type I supernova models, most based upon accreting white dwarf stars, are also explored using the expected light curves, spectra, and nucleosynthesis as diagnostics. No clearly favored Type I model emerges that is capable of simultaneously satisfying all three constraints

  20. Direct imaging of explosives

    International Nuclear Information System (INIS)

    Any technique that can detect nitrogen concentrations can screen for concealed explosives. However, such a technique would have to be insensitive to metal, both encasing and incidental. If images of the nitrogen concentrations could be captured, then, since form follows function, a robust screening technology could be developed. However these images would have to be sensitive to the surface densities at or below that of the nitrogen contained in buried anti-personnel mines or of the SEMTEX that brought down Pan Am 103, ∼200 g. Although the ability to image in three-dimensions would somewhat reduce false positives, capturing collateral images of carbon and oxygen would virtually assure that nitrogenous non-explosive material like fertilizer, Melmac[reg] dinnerware, and salami could be eliminated. We are developing such an instrument, the Nitrogen Camera, which has met experimentally these criteria with the exception of providing oxygen images, which awaits the availability of a sufficiently energetic light source. Our Nitrogen Camera technique uses an electron accelerator to produce photonuclear reactions whose unique decays it registers. Clearly if our Nitrogen Camera is made mobile, it could be effective in detecting buried mines, either in an active battlefield situation or in the clearing of abandoned military munitions. Combat operations require that a swathe the width of an armored vehicle, 5 miles deep, be screened in an hour, which is within our camera's scanning speed. Detecting abandoned munitions is technically easier as it is free from the onerous speed requirement. We describe here our Nitrogen Camera and show its 180 pixel intensity images of elemental nitrogen in a 200 g mine simulant and in a 125 g stick of SEMTEX. We also report on our progress in creating a lorry transportable 70 MeV electron racetrack microtron, the principal enabling technology that will allow our Nitrogen Camera to be deployed in the field

  1. Literature review of the lifetime of DOE materials: Aging of plastic bonded explosives and the explosives and polymers contained therein

    Energy Technology Data Exchange (ETDEWEB)

    Burgess, C.E.; Woodyard, J.D. [West Texas A and M Univ., Canyon, TX (United States); Rainwater, K.A. [Texas Tech Univ., Lubbock, TX (United States); Lightfoot, J.M. [Pantex Plant, Amarillo, TX (United States); Richardson, B.R. [Engineered Carbons, Inc., Borger, TX (United States)

    1998-09-01

    There are concerns about the lifetime of the nation`s stockpile of high explosives (HEs) and their components. The DOE`s Core Surveillance and Enhanced Surveillance programs specifically target degradation of HE, binders, and plastic-bonded explosives (PBXs) for determination of component lifetimes and handling procedures. The principal goal of this project is to identify the decomposition mechanisms of HEs, plasticizers, and plastic polymer binders resulting from exposure to ionizing radiation, heat, and humidity. The primary HEs of concern are 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) and 1,3,5,7-tetranitro-1,3,5,7-tetraazocyclooctane (HMX). Hexahydro-1,3,5-triazine (RDX) is closely related to these two compounds and is also included in the literature review. Both Kel-F 800 and Estane are polymers of interest. A stabilizer, Irganox 1010, and an energetic plasticizer that is a blend of acetaldehyde 2,2-dinitropropyl acetal, are also of interest, but the focus of this report will be on the explosives and polymers. This presents a literature review that provides background on the synthesis, degradation, and techniques to analyze TATB, HMX, RDX, Kel-F 800, Estane, and the PBXs of these compounds. As there are many factors that can influence degradation of materials, the degradation discussion will be divided into sections based on each factor and how it might affect the degradation mechanism. The factors reviewed that influence the degradation of these materials are exposure to heat, UV- and {gamma}-irradiation, and the chemistry of these compounds. The report presents a recently compiled accounting of the available literature. 80 refs., 7 figs.

  2. Optical detection of explosives: spectral signatures for the explosive bouquet

    Science.gov (United States)

    Osborn, Tabetha; Kaimal, Sindhu; Causey, Jason; Burns, William; Reeve, Scott

    2009-05-01

    Research with canines suggests that sniffer dogs alert not on the odor from a pure explosive, but rather on a set of far more volatile species present in an explosive as impurities. Following the explosive trained canine example, we have begun examining the vapor signatures for many of these volatile impurities utilizing high resolution spectroscopic techniques in several molecular fingerprint regions. Here we will describe some of these high resolution measurements and discuss strategies for selecting useful spectral signature regions for individual molecular markers of interest.

  3. Back To Bacteria.

    Science.gov (United States)

    Flannery, Maura C.

    1997-01-01

    Explores new research about bacteria. Discusses bacterial genomes, archaea, unusual environments, evolution, pathogens, bacterial movement, biofilms, bacteria in the body, and a bacterial obsession. Contains 29 references. (JRH)

  4. He-Ne激光诱变选育高效石油烃降解菌的研究%Study on screening of a highly petroleum hydrocarbon-degrading bacteria by He-Ne laser induced mutation

    Institute of Scientific and Technical Information of China (English)

    张子间; 刘勇弟; 卢杰; 张立辉

    2012-01-01

    采用He-Ne激光器对绿针假单胞菌(Pseudomonas chlororaphis)进行激光诱变育种。在激光照射功率10 mW,时间10 min条件下,筛选到一株遗传性状稳定的高效石油烃降解菌PS 2。摇瓶实验发现当培养液中初始柴油含量为0.2%~0.5%(V/V)、温度为30℃左右、pH值为7~8的条件下,突变菌PS 2对石油烃的降解效果最好。在最适生长条件下,突变菌PS 2在120 h内将培养液中的石油烃完全降解且不存在延滞期,比出发菌株少用24 h。结果表明,He-Ne激光诱变育种技术是获得高效石油烃降解菌的有效途径之一。%The Pseudomonas chlororaphis was irradiated at 10 mW for 10 minutes using He-Ne laser.A mutant PS 2 with steady genetic characteristics and high degradation rate of petroleum hydrocarbon was obtained.The result showed that degradation efficiency is satisfactory when the content of petroleum hydrocarbon is 0.2%-0.5%(V/V),temperture is about 30℃,pH is 7-8 in the batch culture experiment.Under these conditions for optimum growth,petroleum hydrocarbon could be completely degraded by mutant PS 2 within 120 h without lag phase.The results showed that laser inducing was one of effective ways for screening excellent petroleum hydrocarbon-degrading strains.

  5. Discriminating between explosions and earthquakes

    Science.gov (United States)

    Cho, Kwang-Hyun

    2014-12-01

    Earthquake, explosion, and a nuclear test data are compared with forward modeling and band-pass filtered surface wave amplitude data for exploring methodologies to improve earthquake-explosion discrimination. The proposed discrimination method is based on the solutions of a double integral transformation in the wavenumber and frequency domains. Recorded explosion data on June 26, 2001 (39.212°N, 125.383°E) and October 30, 2001 (38.748°N, 125.267°E), a nuclear test on October 9, 2006 (41.275°N, 129.095°E), and two earthquakes on April 14, 2002 (39.207°N, 125.686°E) and June 7, 2002 (38.703°N, 125.638°E), all in North Korea, are used to discriminate between explosions and earthquakes by seismic wave analysis and numerical modeling. The explosion signal is characterized by first P waves with higher energy than that of S waves. Rg waves are clearly dominant at 0.05-0.5 Hz in the explosion data but not in the earthquake data. This feature is attributed to the dominant P waves in the explosion and their coupling with the SH components.

  6. Biodegradation of Asphalt Cement-20 by Aerobic Bacteria

    OpenAIRE

    Pendrys, John P.

    1989-01-01

    Seven gram-negative, aerobic bacteria were isolated from a mixed culture enriched for asphalt-degrading bacteria. The predominant genera of these isolates were Pseudomonas, Acinetobacter, Alcaligenes, Flavimonas, and Flavobacterium. The mixed culture preferentially degraded the saturate and naphthene aromatic fractions of asphalt cement-20. A residue remained on the surface which was resistant to biodegradation and protected the underlying asphalt from biodegradation. The most potent asphalt-...

  7. Explosive signatures: Pre & post blast

    Science.gov (United States)

    Bernier, Evan Thomas

    Manuscripts 1 and 2 of this dissertation both involve the pre-blast detection of trace explosive material. The first manuscript explores the analysis of human hair as an indicator of exposure to explosives. Field analysis of hair for trace explosives is quick and non-invasive, and could prove to be a powerful linkage to physical evidence in the form of bulk explosive material. Individuals tested were involved in studies which required handling or close proximity to bulk high explosives such as TNT, PETN, and RDX. The second manuscript reports the results of research in the design and application of canine training aids for non-traditional, peroxide-based explosives. Organic peroxides such as triacetonetriperoxide (TATP) and hexamethylenetriperoxidediamine (HMTD) can be synthesized relatively easily with store-bought ingredients and have become popular improvised explosives with many terrorist groups. Due to the hazards of handling such sensitive compounds, this research established methods for preparing training aids which contained safe quantities of TATP and HMTD for use in imprinting canines with their characteristic odor. Manuscripts 3 and 4 of this dissertation focus on research conducted to characterize pipe bombs during and after an explosion (post-blast). Pipe bombs represent a large percentage of domestic devices encountered by law enforcement. The current project has involved the preparation and controlled explosion of over 90 pipe bombs of different configurations in order to obtain data on fragmentation patterns, fragment velocity, blast overpressure, and fragmentation distance. Physical data recorded from the collected fragments, such as mass, size, and thickness, was correlated with the relative power of the initial device. Manuscript 4 explores the microstructural analysis of select pipe bomb fragments. Shock-loading of the pipe steel led to plastic deformation and work hardening in the steel grain structure as evidenced by optical microscopy and

  8. A method for detecting explosives

    International Nuclear Information System (INIS)

    Bombs concealed in luggage have threatened human life and property throughout the world's traffic. The plastic explosives could not be checked by the X-ray detecting device. A method has been tested in the present work for non-destructive detection of explosives. A neutron generator and relevant apparatus have been used as a tool to find explosives, regardless of the bomb's shape and the packing materials. It seems that this method is a promising one because of the strong transmission ability of both the incident and output specific radiations and low background. (author) 4 figs.; 4 tabs

  9. Noise From Shallow Underwater Explosions

    Science.gov (United States)

    Soloway, Alexander G.

    Naval activities such as ordnance disposal, demolition and requisite training, can involve detonation of small explosive charges in shallow water that have the potential to harm nearby marine life. Measurements of the underwater sound generated by sub-surface explosions were collected as part of a naval training exercise. In this thesis the noise levels from these explosions will be investigated using peak pressure, sound exposure level and energy spectral density. Measurements of very-low frequency Scholte interface waves will also be presented and used to investigate elastic parameters in the sediment.

  10. Degradation of TATP, TNT, and RDX using mechanically alloyed metals

    Science.gov (United States)

    Clausen, Christian (Inventor); Geiger, Cherie (Inventor); Sigman, Michael (Inventor); Fidler, Rebecca (Inventor)

    2012-01-01

    Bimetallic alloys prepared in a ball milling process, such as iron nickel (FeNi), iron palladium (FePd), and magnesium palladium (MgPd) provide in situ catalyst system for remediating and degrading nitro explosive compounds. Specifically, munitions, such as, 2,4,6-trinitrotoluene (TNT), cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX), nitrocellulose and nitroglycerine that have become contaminants in groundwater, soil, and other structures are treated on site to remediate explosive contamination.

  11. Novel methods for detecting buried explosive devices

    Energy Technology Data Exchange (ETDEWEB)

    Kercel, S.W.; Burlage, R.S.; Patek, D.R.; Smith, C.M. [Oak Ridge National Lab., TN (United States); Hibbs, A.D.; Rayner, T.J. [Quantum Magnetics, Inc., San Diego, CA (United States)

    1997-04-01

    Oak Ridge National Laboratory (ORNL) and Quantum Magnetics, Inc. (QM) are exploring novel landmine detection technologies. Technologies considered here include bioreporter bacteria, swept acoustic resonance, nuclear quadrupole resonance (NQR), and semiotic data fusion. Bioreporter bacteria look promising for third-world humanitarian applications; they are inexpensive, and deployment does not require high-tech methods. Swept acoustic resonance may be a useful adjunct to magnetometers in humanitarian demining. For military demining, NQR is a promising method for detecting explosive substances; of 50,000 substances that have been tested, none has an NQR signature that can be mistaken for RDX or TNT. For both military and commercial demining, sensor fusion entails two daunting tasks, identifying fusible features in both present-day and emerging technologies, and devising a fusion algorithm that runs in real-time on cheap hardware. Preliminary research in these areas is encouraging. A bioreporter bacterium for TNT detection is under development. Investigation has just started in swept acoustic resonance as an approach to a cheap mine detector for humanitarian use. Real-time wavelet processing appears to be a key to extending NQR bomb detection into mine detection, including TNT-based mines. Recent discoveries in semiotics may be the breakthrough that will lead to a robust fused detection scheme.

  12. Explosive actuated valves

    Science.gov (United States)

    Cobb, Jr., Lawrence L.

    1983-01-01

    1. A device of the character described comprising the combination of a generally tubular housing having an end portion forming a chamber to receive the sensitive portion of an explosive squib, a plunger within said housing having an end portion exposed to said chamber, squib retaining means for engaging said housing and a said squib to releasably maintain the squib in close proximity to said plunger end portion including a retaining ring of fusible material spaced outwardly from and encircling at least part of a said squib and part of its sensitive portion for reception of heat from an external source prior to appreciable reception thereof by the sensitive portion of the squib, an annular compression spring bearing at one end against said housing for urging at least a portion of the squib retaining means and a said squib away from said housing and from said plunger end portion upon subjection of the fusible material to heat sufficient to melt at least a portion thereof, and guide means for said spring to maintain even expansion thereof as a said squib is being urged away from said housing.

  13. Explosive actuated valve

    Science.gov (United States)

    Byrne, Kenneth G.

    1983-01-01

    1. A device of the character described comprising the combination of a housing having an elongate bore and including a shoulder extending inwardly into said bore, a single elongate movable plunger disposed in said bore including an outwardly extending flange adjacent one end thereof overlying said shoulder, normally open conduit means having an inlet and an outlet perpendicularly piercing said housing intermediate said shoulder and said flange and including an intermediate portion intersecting and normally openly communicating with said bore at said shoulder, normally closed conduit means piercing said housing and intersecting said bore at a location spaced from said normally open conduit means, said elongate plunger including a shearing edge adjacent the other end thereof normally disposed intermediate both of said conduit means and overlying a portion of said normally closed conduit means, a deformable member carried by said plunger intermediate said flange and said shoulder and normally spaced from and overlying the intermediate portion of said normally open conduit means, and means on the housing communicating with the bore to retain an explosive actuator for moving said plunger to force the deformable member against the shoulder and extrude a portion of the deformable member out of said bore into portions of the normally open conduit means for plugging the same and to effect the opening of said normally closed conduit means by the plunger shearing edge substantially concomitantly with the plugging of the normally open conduit means.

  14. Explosive Contagion in Networks

    Science.gov (United States)

    Gómez-Gardeñes, J.; Lotero, L.; Taraskin, S. N.; Pérez-Reche, F. J.

    2016-01-01

    The spread of social phenomena such as behaviors, ideas or products is an ubiquitous but remarkably complex phenomenon. A successful avenue to study the spread of social phenomena relies on epidemic models by establishing analogies between the transmission of social phenomena and infectious diseases. Such models typically assume simple social interactions restricted to pairs of individuals; effects of the context are often neglected. Here we show that local synergistic effects associated with acquaintances of pairs of individuals can have striking consequences on the spread of social phenomena at large scales. The most interesting predictions are found for a scenario in which the contagion ability of a spreader decreases with the number of ignorant individuals surrounding the target ignorant. This mechanism mimics ubiquitous situations in which the willingness of individuals to adopt a new product depends not only on the intrinsic value of the product but also on whether his acquaintances will adopt this product or not. In these situations, we show that the typically smooth (second order) transitions towards large social contagion become explosive (first order). The proposed synergistic mechanisms therefore explain why ideas, rumours or products can suddenly and sometimes unexpectedly catch on.

  15. Furball Explosive Breakout Test

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, Joshua David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-05

    For more than 30 years the Onionskin test has been the primary way to study the surface breakout of a detonation wave. Currently the Onionskin test allows for only a small, one dimensional, slice of the explosive in question to be observed. Asymmetrical features are not observable with the Onionskin test and its one dimensional view. As a result, in 2011, preliminary designs for the Hairball and Furball were developed then tested. The Hairball used shorting pins connected to an oscilloscope to determine the arrival time at 24 discrete points. This limited number of data points, caused by the limited number of oscilloscope channels, ultimately led to the Hairball’s demise. Following this, the Furball was developed to increase the number of data points collected. Instead of shorting pins the Furball uses fiber optics imaged by a streak camera to determine the detonation wave arrival time for each point. The original design was able to capture the detonation wave’s arrival time at 205 discrete points with the ability to increase the number of data points if necessary.

  16. Disaster management following explosion.

    Science.gov (United States)

    Sharma, B R

    2008-01-01

    Explosions and bombings remain the most common deliberate cause of disasters involving large numbers of casualties, especially as instruments of terrorism. These attacks are virtually always directed against the untrained and unsuspecting civilian population. Unlike the military, civilians are poorly equipped or prepared to handle the severe emotional, logistical, and medical burdens of a sudden large casualty load, and thus are completely vulnerable to terrorist aims. To address the problem to the maximum benefit of mass disaster victims, we must develop collective forethought and a broad-based consensus on triage and these decisions must reach beyond the hospital emergency department. It needs to be realized that physicians should never be placed in a position of individually deciding to deny treatment to patients without the guidance of a policy or protocol. Emergency physicians, however, may easily find themselves in a situation in which the demand for resources clearly exceeds supply and for this reason, emergency care providers, personnel, hospital administrators, religious leaders, and medical ethics committees need to engage in bioethical decision-making. PMID:18522253

  17. The Cambrian explosion.

    Science.gov (United States)

    Briggs, Derek E G

    2015-10-01

    The sudden appearance of fossils that marks the so-called 'Cambrian explosion' has intrigued and exercised biologists since Darwin's time. In On the Origin of Species, Darwin made it clear that he believed that ancestral forms 'lived long before' their first fossil representatives. While he considered such an invisible record necessary to explain the level of complexity already seen in the fossils of early trilobites, Darwin was at a loss to explain why there were no corresponding fossils of these earlier forms. In chapter 9 of the Origin, entitled 'On the imperfection of the geological record', he emphasized the 'poorness of our palaeontological collections' and stated categorically that 'no organism wholly soft can be preserved'. Fortunately much has been discovered in the last 150 years, not least multiple examples of Cambrian and Precambrian soft-bodied fossils. We now know that the sudden appearance of fossils in the Cambrian (541-485 million years ago) is real and not an artefact of an imperfect fossil record: rapid diversification of animals coincided with the evolution of biomineralized shells. And although fossils in earlier rocks are rare, they are not absent: their rarity reflects the low diversity of life at this time, as well as the low preservation potential of Precambrian organisms (see Primer by Butterfield, in this issue). PMID:26439348

  18. Suppression of stratified explosive interactions

    Energy Technology Data Exchange (ETDEWEB)

    Meeks, M.K.; Shamoun, B.I.; Bonazza, R.; Corradini, M.L. [Wisconsin Univ., Madison, WI (United States). Dept. of Nuclear Engineering and Engineering Physics

    1998-01-01

    Stratified Fuel-Coolant Interaction (FCI) experiments with Refrigerant-134a and water were performed in a large-scale system. Air was uniformly injected into the coolant pool to establish a pre-existing void which could suppress the explosion. Two competing effects due to the variation of the air flow rate seem to influence the intensity of the explosion in this geometrical configuration. At low flow rates, although the injected air increases the void fraction, the concurrent agitation and mixing increases the intensity of the interaction. At higher flow rates, the increase in void fraction tends to attenuate the propagated pressure wave generated by the explosion. Experimental results show a complete suppression of the vapor explosion at high rates of air injection, corresponding to an average void fraction of larger than 30%. (author)

  19. Explosive Blast Neuropathology and Seizures

    Directory of Open Access Journals (Sweden)

    S. Krisztian eKovacs

    2014-04-01

    Full Text Available Traumatic brain injury (TBI due to explosive blast exposure is a leading combat casualty. It is also implicated as a key contributor to war related mental health diseases. A clinically important consequence of all types of TBI is a high risk for development of seizures and epilepsy. Seizures have been reported in patients who have suffered blast injuries in the Global War on Terror but the exact prevalence is unknown. The occurrence of seizures supports the contention that explosive blast leads to both cellular and structural brain pathology. Unfortunately, the exact mechanism by which explosions cause brain injury is unclear, which complicates development of meaningful therapies and mitigation strategies. To help improve understanding, detailed neuropathological analysis is needed. For this, histopathological techniques are extremely valuable and indispensable. In the following we will review the pathological results, including those from immunohistochemical and special staining approaches, from recent preclinical explosive blast studies.

  20. Explosive plane-wave lens

    Science.gov (United States)

    Marsh, Stanley P.

    1988-01-01

    An explosive plane-wave air lens which enables a spherical wave form to be converted to a planar wave without the need to specially machine or shape explosive materials is described. A disc-shaped impactor having a greater thickness at its center than around its periphery is used to convert the spherical wave into a plane wave. When the wave reaches the impactor, the center of the impactor moves first because the spherical wave reaches the center of the impactor first. The wave strikes the impactor later in time as one moves radially along the impactor. Because the impactor is thinner as one moves radially outward, the velocity of the impactor is greater at the periphery than at the center. An acceptor explosive is positioned so that the impactor strikes the acceptor simultaneously. Consequently, a plane detonation wave is propagated through the acceptor explosive.

  1. Explosive Spot Joining of Metals

    Science.gov (United States)

    Bement, Laurence J. (Inventor); Perry, Ronnie B. (Inventor)

    1997-01-01

    The invention is an apparatus and method for wire splicing using an explosive joining process. The apparatus consists of a prebend, U-shaped strap of metal that slides over prepositioned wires. A standoff means separates the wires from the strap before joining. An adhesive means holds two ribbon explosives in position centered over the U-shaped strap. A detonating means connects to the ribbon explosives. The process involves spreading strands of each wire to be joined into a flat plane. The process then requires alternating each strand in alignment to form a mesh-like arrangement with an overlapped area. The strap slides over the strands of the wires. and the standoff means is positioned between the two surfaces. The detonating means then initiates the ribbon explosives that drive the strap to accomplish a high velocity. angular collision between the mating surfaces. This collision creates surface melts and collision bonding resulting in electron-sharing linkups.

  2. Phenomenological modelling of steam explosions

    International Nuclear Information System (INIS)

    During a hypothetical core meltdown accident, an important safety issue to be addressed is the potential for steam explosions. This paper presents analysis and modelling of experimental results. There are four observations that can be drawn from the analysis: (1) vapor explosions are suppressed by noncondensible gases generated by fuel oxidation, by high ambient pressure, and by high water temperatures; (2) these effects appear to be trigger-related in that an explosion can again be induced in some cases by increasing the trigger magnitude; (3) direct fuel liquid-coolant liquid contact can explain small scale fuel fragmentation; (4) heat transfer during the expansion phase of the explosion can reduce the work potential

  3. Nuclear explosions for peaceful purposes

    International Nuclear Information System (INIS)

    Theoretical and technological aspects as well as peaceful applications of nuclear explosions are discussed emphasizing on contained and cratering explosions. For both types of explosions phenomenology as well as the dimensions of cavity and chimney or of the crater and their predictability are described. As regards applications engineering applications, e.g., canal and harbour construction, industrial applications, e.g., oil reservoir stimulation, oil shale recovery, natural gas stimulation and storage, in-site mineral recovery, and scientific applications, e.g., in neutron physics and geophysics, are dealt with. Safety aspects are discussed considering air-blast effects, soil movement and radiological effects depending on the two types of explosions. Finally, several national programs are outlined

  4. Explosion modelling for complex geometries

    Science.gov (United States)

    Nehzat, Naser

    A literature review suggested that the combined effects of fuel reactivity, obstacle density, ignition strength, and confinement result in flame acceleration and subsequent pressure build-up during a vapour cloud explosion (VCE). Models for the prediction of propagating flames in hazardous areas, such as coal mines, oil platforms, storage and process chemical areas etc. fall into two classes. One class involves use of Computation Fluid Dynamics (CFD). This approach has been utilised by several researchers. The other approach relies upon a lumped parameter approach as developed by Baker (1983). The former approach is restricted by the appropriateness of sub-models and numerical stability requirements inherent in the computational solution. The latter approach raises significant questions regarding the validity of the simplification involved in representing the complexities of a propagating explosion. This study was conducted to investigate and improve the Computational Fluid Dynamic (CFD) code EXPLODE which has been developed by Green et al., (1993) for use on practical gas explosion hazard assessments. The code employs a numerical method for solving partial differential equations by using finite volume techniques. Verification exercises, involving comparison with analytical solutions for the classical shock-tube and with experimental (small-scale, medium and large-scale) results, demonstrate the accuracy of the code and the new combustion models but also identify differences between predictions and the experimental results. The project has resulted in a developed version of the code (EXPLODE2) with new combustion models for simulating gas explosions. Additional features of this program include the physical models necessary to simulate the combustion process using alternative combustion models, improvement to the numerical accuracy and robustness of the code, and special input for simulation of different gas explosions. The present code has the capability of

  5. Structural Biology of Pectin Degradation by Enterobacteriaceae

    OpenAIRE

    Abbott, D. Wade; Boraston, Alisdair B.

    2008-01-01

    Pectin is a structural polysaccharide that is integral for the stability of plant cell walls. During soft rot infection, secreted virulence factors from pectinolytic bacteria such as Erwinia spp. degrade pectin, resulting in characteristic plant cell necrosis and tissue maceration. Catabolism of pectin and its breakdown products by pectinolytic bacteria occurs within distinct cellular environments. This process initiates outside the cell, continues within the periplasmic space, and culminates...

  6. Simulation Analysis of Indoor Gas Explosion Damage

    Institute of Scientific and Technical Information of China (English)

    钱新明; 陈林顺; 冯长根

    2003-01-01

    The influence factors and process of indoor gas explosion are studied with AutoReaGas explosion simulator. The result shows that venting pressure has great influence on the indoor gas explosion damage. The higher the venting pressure is, the more serious the hazard consequence will be. The ignition location has also evident effect on the gas explosion damage. The explosion static overpressure would not cause major injury to person and serious damage to structure in the case of low venting pressure (lower than 2 kPa). The high temperature combustion after the explosion is the major factor to person injury in indoor gas explosion accidents.

  7. Tagging of Explosives for Detection

    Directory of Open Access Journals (Sweden)

    J. S. Gharia

    2000-01-01

    Full Text Available This paper gives the results of a study on estimation of shelf life of2,3-dimethyI2,3-dinitrobutane (DMNB-tagged RDX and PETN expiosives by monitoring DMNB depletion by high performanceliquid chromatography and simultaneously recording the detectability of the tagged explosive composition using explosive vapoUf detector Model-97 HS. DMNB was incorporated in the explosive using methanol as solvent for DMNB and the explosive compositions were stored at 35,55 and 75 °C over a long period. Methods developed for preparing the homogeneously tagged composition with DMNB at 0.5 per cent level and for the analysis ofDMNB for ensuring homogeneity of DMNB in the composition are described. The results show no change in compatibility and sensitivity on the incorporation of DMNB in the explosive. Estimation of shelf life of DMNB in the explosive was done for a period of storage of 202-304 days at different temperatures.

  8. Explosive Characteristics of Carbonaceous Nanoparticles

    Science.gov (United States)

    Turkevich, Leonid; Fernback, Joseph; Dastidar, Ashok

    2013-03-01

    Explosion testing has been performed on 20 codes of carbonaceous particles. These include SWCNTs (single-walled carbon nanotubes), MWCNTs (multi-walled carbon nanotubes), CNFs (carbon nanofibers), graphene, diamond, fullerene, carbon blacks and graphites. Explosion screening was performed in a 20 L explosion chamber (ASTM E1226-10 protocol), at a (dilute) concentration of 500 g/m3, using a 5 kJ ignition source. Time traces of overpressure were recorded. Samples exhibited overpressures of 5-7 bar, and deflagration index KSt = V1/3 (dp/pt)max ~ 10 - 80 bar-m/s, which places these materials in European Dust Explosion Class St-1 (similar to cotton and wood dust). There was minimal variation between these different materials. The explosive characteristics of these carbonaceous powders are uncorrelated with particle size (BET specific surface area). Additional tests were performed on selected materials to identify minimum explosive concentration [MEC]. These materials exhibit MEC ~ 101 -102 g/m3 (lower than the MEC for coals). The concentration scans confirm that the earlier screening was performed under fuel-rich conditions (i.e. the maximum over-pressure and deflagration index exceed the screening values); e.g. the true fullerene KSt ~ 200 bar-m/s, placing it borderline St-1/St-2. Work supported through the NIOSH Nanotechnology Research Center (NTRC)

  9. Hydrocarbon production with nuclear explosives

    International Nuclear Information System (INIS)

    The tremendous energy of nuclear explosives and the small dimensions of the explosive package make an ideal combination for drill-hole explosive emplacement in deep, thick hydrocarbon deposits. Potential applications exist in fracturing low permeability natural-gas and petroleum formations for stimulating production, fracturing oil shale to permit in situ retorting, and creating storage chimneys for natural gas, liquefied petroleum gas, petroleum, petroleum products, helium, and other fluids. Calculations show, for example, that less than 100 shots per year would be needed to stabilize the natural gas reserves to production ratio. Under the Government-industry Plowshare program, two experiments, Projects Gasbuggy and Rulison, were conducted to stimulate natural gas production from low-permeability formations. Incomplete information indicates that both were technically successful. Potential problems associated with the use of nuclear explosives for underground engineering applications are radioactive contamination, maximum yield limitations, high costs of detonating contained nuclear explosives, and adverse public opinion. Results at Project Gasbuggy and other considerations indicated that the problem of radioactive contamination was about as predicted and not an insurmountable one. Also, it was demonstrated that shots at adequate depths could be detonated without appreciable damage to existing surface and subsurface buildings, natural features, and equipment. However, costs must be reduced and the public must be better informed before these techniques can be widely used in field operations. On the basis of present knowledge, the potential of nuclear-explosive stimulation of hydrocarbon production appears good. Additional field experiments will be required to adequately explore that potential. (author)

  10. Genetically engineered microorganisms for the detection of explosives' residues

    Directory of Open Access Journals (Sweden)

    Benjamin eShemer

    2015-10-01

    Full Text Available The manufacture and use of explosives throughout the past century has resulted in the extensive pollution of soils and groundwater, and the widespread interment of landmines imposes a major humanitarian risk and prevents civil development of large areas. As most current landmine detection technologies require actual presence at the surveyed areas, thus posing a significant risk to personnel, diverse research efforts are aimed at the development of remote detection solutions. One possible means proposed to fulfill this objective is the use of microbial bioreporters: genetically engineered microorganisms tailored to generate an optical signal in the presence of explosives’ vapors. The use of such sensor bacteria will allow to pinpoint the locations of explosive devices in a minefield. While no study has yet resulted in a commercially operational system, significant progress has been made in the design and construction of explosives-sensing bacterial strains. In this article we review the attempts to construct microbial bioreporters for the detection of explosives, and analyze the steps that need to be undertaken for this strategy to be applicable for landmine detection.

  11. Evaluación de la diversidad de bacterias degradadoras de hidrocarburos aisladas de suelos de las cuencas de los ríos Otún y La Vieja / Evaluation of hydrocarbon degrading bacteria diversity isolated from soils of Otún and La Vieja river basins

    OpenAIRE

    Yanine Suárez, Habib Fernando

    2010-01-01

    Se evaluó el efecto del uso del suelo, sobre la densidad y diversidad de bacterias degradadoras de hidrocarburos (HC). Se seleccionaron los usos: bosque, pastizal y cafetal en la cuenca del río La Vieja (Valle del Cauca y Quindío), y bosque, cebollar y plantación forestal en la cuenca del río Otún (Risaralda) y se realizaron dos eventos de muestreo. La densidad se evaluó mediante la técnica de NMP en medio Bushnell-Hass, suplementado con diesel y usando XTT como indicador de actividad. Las ba...

  12. Bacteria in crude oil survived autoclaving and stimulated differentially by exogenous bacteria.

    Science.gov (United States)

    Gong, Xiao-Cui; Liu, Ze-Shen; Guo, Peng; Chi, Chang-Qiao; Chen, Jian; Wang, Xing-Biao; Tang, Yue-Qin; Wu, Xiao-Lei; Liu, Chun-Zhong

    2012-01-01

    Autoclaving of crude oil is often used to evaluate the hydrocarbon-degrading abilities of bacteria. This may be potentially useful for bioaugmentation and microbial enhanced oil recovery (MEOR). However, it is not entirely clear if "endogenous" bacteria (e.g., spores) in/on crude oil survive the autoclaving process, or influence subsequent evaluation of the hydrocarbon-degradation abilities of the "exogenous" bacterial strains. To test this, we inoculated autoclaved crude oil medium with six exogenous bacterial strains (three Dietzia strains, two Acinetobacter strains, and one Pseudomonas strain). The survival of the spore-forming Bacillus and Paenibacillus and the non-spore-forming mesophilic Pseudomonas, Dietzia, Alcaligenes, and Microbacterium was detected using a 16S rRNA gene clone library and terminal restriction fragment length polymorphism (T-RFLP) analysis. However, neither bacteria nor bacterial activity was detected in three controls consisting of non-inoculated autoclaved crude oil medium. These results suggest that detection of endogenous bacteria was stimulated by the six inoculated strains. In addition, inoculation with Acinetobacter spp. stimulated detection of Bacillus, while inoculation with Dietzia spp. and Pseudomonas sp. stimulated the detection of more Pseudomonas. In contrast, similar exogenous bacteria stimulated similar endogenous bacteria at the genus level. Based on these results, special emphasis should be applied to evaluate the influence of bacteria capable of surviving autoclaving on the hydrocarbon-degrading abilities of exogenous bacteria, in particular, with regard to bioaugmentation and MEOR. Bioaugmentation and MEOR technologies could then be developed to more accurately direct the growth of specific endogenous bacteria that may then improve the efficiency of treatment or recovery of crude oil. PMID:23028421

  13. Bacteria in crude oil survived autoclaving and stimulated differentially by exogenous bacteria.

    Directory of Open Access Journals (Sweden)

    Xiao-Cui Gong

    Full Text Available Autoclaving of crude oil is often used to evaluate the hydrocarbon-degrading abilities of bacteria. This may be potentially useful for bioaugmentation and microbial enhanced oil recovery (MEOR. However, it is not entirely clear if "endogenous" bacteria (e.g., spores in/on crude oil survive the autoclaving process, or influence subsequent evaluation of the hydrocarbon-degradation abilities of the "exogenous" bacterial strains. To test this, we inoculated autoclaved crude oil medium with six exogenous bacterial strains (three Dietzia strains, two Acinetobacter strains, and one Pseudomonas strain. The survival of the spore-forming Bacillus and Paenibacillus and the non-spore-forming mesophilic Pseudomonas, Dietzia, Alcaligenes, and Microbacterium was detected using a 16S rRNA gene clone library and terminal restriction fragment length polymorphism (T-RFLP analysis. However, neither bacteria nor bacterial activity was detected in three controls consisting of non-inoculated autoclaved crude oil medium. These results suggest that detection of endogenous bacteria was stimulated by the six inoculated strains. In addition, inoculation with Acinetobacter spp. stimulated detection of Bacillus, while inoculation with Dietzia spp. and Pseudomonas sp. stimulated the detection of more Pseudomonas. In contrast, similar exogenous bacteria stimulated similar endogenous bacteria at the genus level. Based on these results, special emphasis should be applied to evaluate the influence of bacteria capable of surviving autoclaving on the hydrocarbon-degrading abilities of exogenous bacteria, in particular, with regard to bioaugmentation and MEOR. Bioaugmentation and MEOR technologies could then be developed to more accurately direct the growth of specific endogenous bacteria that may then improve the efficiency of treatment or recovery of crude oil.

  14. Analysis of anionic post-blast residues of low explosives from soil samples of forensic interest

    International Nuclear Information System (INIS)

    The growing threats and terrorist activities in recent years have urged the need for rapid and accurate forensic investigation on post-blast samples. The analysis of explosives and their degradation products in soils are important to enable forensic scientist to identify the explosives used in the bombing and establish possible links to their likely origin. Anions of interest for post-blast identification of low explosives were detected and identified using ion chromatography (IC). IC separations of five anions (Cl-, NO2-, NO3-, SO42-, SCN-) employed a Metrosep Anion Dual 2 column with carbonate eluent. The anions were separated within 17 minutes. Sampling of post blast residues was carried out in Rompin, Pahang. The post-blast explosive residues were extracted from soil samples collected at the seat of three simulated explosion points. The homemade explosives comprised of black powder of various amounts (100 g, 150 g and 200 g) packed in small plastic sauce bottles. In black powder standard, three anions (Cl-, NO3-, SO42-) were identified. However, low amounts of nitrite (NO2-) were found present in post-blast soil samples. The amounts of anions were generally found to be decreased with decreasing amount of black powder explosive used. The anions analysis was indicative that nitrates were being used as one of the black powder explosive ingredients. (author)

  15. [Ligninolytic Activity of Bacteria of the Genera Azospirillum and Niveispirillum].

    Science.gov (United States)

    Kupryashina, M A; Petrov, S V; Ponomareva, E G; Nikitina, V E

    2015-01-01

    Capacity of associative soil bacteria of the genera Azospirillum and Niveispirillum for degradation of lignin model compounds was demonstrated. Lignin and Mn-peroxidases were detected in the culture liquid of the type strains of these genera. The data on involvement of nonspecific bacterial peroxidases in lignin degradation were obtained. PMID:26964358

  16. Effects of oral administration of metronidazole and doxycycline on olfactory capabilities of explosives detection dogs.

    Science.gov (United States)

    Jenkins, Eileen K; Lee-Fowler, Tekla M; Angle, T Craig; Behrend, Ellen N; Moore, George E

    2016-08-01

    OBJECTIVE To determine effects of oral administration of metronidazole or doxycycline on olfactory function in explosives detection (ED) dogs. ANIMALS 18 ED dogs. PROCEDURES Metronidazole was administered (25 mg/kg, PO, q 12 h for 10 days); the day prior to drug administration was designated day 0. Odor detection threshold was measured with a standard scent wheel and 3 explosives (ammonium nitrate, trinitrotoluene, and smokeless powder; weight, 1 to 500 mg) on days 0, 5, and 10. Lowest repeatable weight detected was recorded as the detection threshold. There was a 10-day washout period, and doxycycline was administered (5 mg/kg, PO, q 12 h for 10 days) and the testing protocol repeated. Degradation changes in the detection threshold for dogs were assessed. RESULTS Metronidazole administration resulted in degradation of the detection threshold for 2 of 3 explosives (ammonium nitrate and trinitrotoluene). Nine of 18 dogs had a degradation of performance in response to 1 or more explosives (5 dogs had degradation on day 5 or 10 and 4 dogs had degradation on both days 5 and 10). There was no significant degradation during doxycycline administration. CONCLUSIONS AND CLINICAL RELEVANCE Degradation in the ability to detect odors of explosives during metronidazole administration at 25 mg/kg, PO, every 12 hours, indicated a potential risk for use of this drug in ED dogs. Additional studies will be needed to determine whether lower doses would have the same effect. Doxycycline administered at the tested dose appeared to be safe for use in ED dogs. PMID:27463556

  17. Summary report on the aerobic degradation of diesel fuel and the degradation of toluene under aerobic, denitrifying and sulfate reducing conditions

    International Nuclear Information System (INIS)

    This report contains a number of studies that were performed to better understand the technology of the biodegradation of petroleum hydrocarbons. Topics of investigation include the following: diesel fuel degradation by Rhodococcus erythropolis; BTEX degradation by soil isolates; aerobic degradation of diesel fuel-respirometry; aerobic degradation of diesel fuel-shake culture; aerobic toluene degradation by A3; effect of HEPES, B1, and myo-inositol addition on the growth of A3; aerobic and anaerobic toluene degradation by contaminated soils; denitrifying bacteria MPNs; sulfate-reducing bacteria MPNs; and aerobic, DNB and SRB enrichments

  18. 76 FR 64974 - Commerce in Explosives; List of Explosive Materials (2011R-18T)

    Science.gov (United States)

    2011-10-19

    ... Explosive Materials dated November 17, 2010 (Docket No. ATF 42N, 75 FR 70291). Notice of List of Explosive... tetrazene hydrate]. Tetrazole explosives. Tetryl . Tetrytol. Thickened inorganic oxidizer salt...

  19. Managing water addition to a degraded core

    International Nuclear Information System (INIS)

    In this paper the authors present an approach to the development of an accident management plan for adding water to a degraded core. Under certain degraded core conditions, adding water may lead to enhanced hydrogen production, changes in core geometry that would complicate recovery, steam explosions, or recriticality of the reactor core if unborated water is used. Therefore, a primary requisite for the development of an accident management plan for adding water to a degraded core is to ensure that undesirable consequences of water addition are understood so that: (1) their effects can be minimized and an accident can be terminated at the earliest possible stage, and (2) plant personnel can be better prepared to deal with plant responses that appear contrary to desired outcomes when water is added during a core degradation transient. The approach presented here addresses these concerns in the development of an accident management plan

  20. Explosive cell lysis as a mechanism for the biogenesis of bacterial membrane vesicles and biofilms.

    Science.gov (United States)

    Turnbull, Lynne; Toyofuku, Masanori; Hynen, Amelia L; Kurosawa, Masaharu; Pessi, Gabriella; Petty, Nicola K; Osvath, Sarah R; Cárcamo-Oyarce, Gerardo; Gloag, Erin S; Shimoni, Raz; Omasits, Ulrich; Ito, Satoshi; Yap, Xinhui; Monahan, Leigh G; Cavaliere, Rosalia; Ahrens, Christian H; Charles, Ian G; Nomura, Nobuhiko; Eberl, Leo; Whitchurch, Cynthia B

    2016-01-01

    Many bacteria produce extracellular and surface-associated components such as membrane vesicles (MVs), extracellular DNA and moonlighting cytosolic proteins for which the biogenesis and export pathways are not fully understood. Here we show that the explosive cell lysis of a sub-population of cells accounts for the liberation of cytosolic content in Pseudomonas aeruginosa biofilms. Super-resolution microscopy reveals that explosive cell lysis also produces shattered membrane fragments that rapidly form MVs. A prophage endolysin encoded within the R- and F-pyocin gene cluster is essential for explosive cell lysis. Endolysin-deficient mutants are defective in MV production and biofilm development, consistent with a crucial role in the biogenesis of MVs and liberation of extracellular DNA and other biofilm matrix components. Our findings reveal that explosive cell lysis, mediated through the activity of a cryptic prophage endolysin, acts as a mechanism for the production of bacterial MVs. PMID:27075392

  1. Handcuffs for bacteria - NDP52 orchestrates xenophagy of intracellular Salmonella

    Directory of Open Access Journals (Sweden)

    Pauline Verlhac

    2015-05-01

    Full Text Available Eukaryotic cells can selectively target and degrade intracellular pathogens using autophagy, a process referred to as xenophagy. This selectivity is controlled by proteins called autophagy receptors, which can recognise pathogens and address them to the autophagy machinery. Among them, NDP52 can recognise Salmonella Typhimurium on the one hand and the ATG8 family member LC3C on the other hand, thus allowing the docking of the bacteria to a growing autophagosome. Additionally, we recently reported that NDP52 is involved in the maturation of the bacteria-containing autophagosome and hence necessary for the ultimate degradation of the bacteria. These two functions of NDP52 are independent as they rely on distinct binding domains and protein partners. Therefore, NDP52 plays a dual role during xenophagy, first by targeting the bacteria to the autophagy machinery and then by regulating its degradation.

  2. Bacteria isolated from amoebae/bacteria consortium

    Science.gov (United States)

    Tyndall, Richard L.

    1995-01-01

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

  3. Degradation and induction specificity in actinomycetes that degrade p-nitrophenol.

    OpenAIRE

    1993-01-01

    We have isolated two soil bacteria (identified as Arthrobacter aurescens TW17 and Nocardia sp. strain TW2) capable of degrading p-nitrophenol (PNP) and numerous other phenolic compounds. A. aurescens TW17 contains a large plasmid which correlated with the PNP degradation phenotype. Degradation of PNP by A. aurescens TW17 was induced by preexposure to PNP, 4-nitrocatechol, 3-methyl-4-nitrophenol, or m-nitrophenol, whereas PNP degradation by Nocardia sp. strain TW2 was induced by PNP, 4-nitroca...

  4. THE INFLUENCE OF BARRIERS ON FLAME AND EXPLOSION WAVE IN GAS EXPLOSION

    Institute of Scientific and Technical Information of China (English)

    林柏泉; 周世宁; 张仁贵

    1998-01-01

    This paper researches into the influence of barriers on flame and explosion wave in gasexplosion on the basis of experiment. The result shows that the barrier is very important to thetransmission of flame and explosion wave in gas explosion. When there are barriers, the speed oftransmission would be very fast and shock wave will appear in gas explosion, which would in-crease gas explosion power. The result of research is very important to prevent gas explosion anddecrease the power of it.

  5. Safe explosives for shaped charges

    International Nuclear Information System (INIS)

    It was demonstrated that high-performance shaped charges could be developed using as the explosive charge mixtures of ingredients that are not, by themselves, considered explosives. At least one of the ingredients needed to be a liquid, stored separately, that could be quickly injected into the shaped charge cavity to generate the active explosive. Precision copper shaped charge cones in diameters of 65.2, 83.8, and 100.2 mm (about 2.6, 3.3, and 4.0 in.) were obtained and appropriate hardware was fabricated. It was demonstrated that 4 cone diameters of penetration were obtained in 255 BHN armor plate steel if the explosive charge was nitromethane or a combination of fine crystalline ammonium nitrate at a density of 1.0 Mg/m3 with nitromethane. However, when prilled ammonium nitrate was used with nitromethane, the jet failed to form. The shaped charges would be used to destroy the high explosive in a nuclear warhead in case of imminent enemy threat to the weapon

  6. Shock Initiation of Heterogeneous Explosives

    International Nuclear Information System (INIS)

    The fundamental picture that shock initiation in heterogeneous explosives is caused by the linking of hot spots formed at inhomogeneities was put forward by several researchers in the 1950's and 1960's, and more recently. Our work uses the computer hardware and software developed in the Advanced Simulation and Computing (ASC) program of the U.S. Department of Energy to explicitly include heterogeneities at the scale of the explosive grains and to calculate the consequences of realistic although approximate models of explosive behavior. Our simulations are performed with ALE-3D, a three-dimensional, elastic-plastic-hydrodynamic Arbitrary Lagrange-Euler finite-difference program, which includes chemical kinetics and heat transfer, and which is under development at this laboratory. We developed the parameter values for a reactive-flow model to describe the non-ideal detonation behavior of an HMX-based explosive from the results of grain-scale simulations. In doing so, we reduced the number of free parameters that are inferred from comparison with experiment to a single one - the characteristic defect dimension. We also performed simulations of the run to detonation in small volumes of explosive. These simulations illustrate the development of the reaction zone and the acceleration of the shock front as the flame fronts start from hot spots, grow, and interact behind the shock front. In this way, our grain-scale simulations can also connect to continuum experiments directly

  7. Explosion limits for combustible gases

    Institute of Scientific and Technical Information of China (English)

    TONG Min-ming; WU Guo-qing; HAO Ji-fei; DAI Xin-lian

    2009-01-01

    Combustible gases in coal mines are composed of methane, hydrogen, some multi-carbon alkane gases and other gases. Based on a numerical calculation, the explosion limits of combustible gases were studied, showing that these limits are related to the concentrations of different components in the mixture. With an increase of C4H10 and C6H14, the Lower ExplosionLimit (LEL) and Upper Explosion-Limit (UEL) of a combustible gas mixture will decrease clearly. For every 0.1% increase in C4H10 and C6H14, the LEL decreases by about 0.19% and the UEL by about 0.3%. The results also prove that, by increasing the amount of H2, the UEL of a combustible gas mixture will increase considerably. If the level of H2 increases by 0.1%, the UEL will increase by about 0.3%. However, H2 has only a small effect on the LEL of the combustible gas mixture. Our study provides a theoretical foundation for judging the explosion risk of an explosive gas mixture in mines.

  8. The Quiet Explosion

    Science.gov (United States)

    2008-07-01

    A European-led team of astronomers are providing hints that a recent supernova may not be as normal as initially thought. Instead, the star that exploded is now understood to have collapsed into a black hole, producing a weak jet, typical of much more violent events, the so-called gamma-ray bursts. The object, SN 2008D, is thus probably among the weakest explosions that produce very fast moving jets. This discovery represents a crucial milestone in the understanding of the most violent phenomena observed in the Universe. Black Hole ESO PR Photo 23a/08 A Galaxy and two Supernovae These striking results, partly based on observations with ESO's Very Large Telescope, will appear tomorrow in Science Express, the online version of Science. Stars that were at birth more massive than about 8 times the mass of our Sun end their relatively short life in a cosmic, cataclysmic firework lighting up the Universe. The outcome is the formation of the densest objects that exist, neutron stars and black holes. When exploding, some of the most massive stars emit a short cry of agony, in the form of a burst of very energetic light, X- or gamma-rays. In the early afternoon (in Europe) of 9 January 2008, the NASA/STFC/ASI Swift telescope discovered serendipitously a 5-minute long burst of X-rays coming from within the spiral galaxy NGC 2770, located 90 million light-years away towards the Lynx constellation. The Swift satellite was studying a supernova that had exploded the previous year in the same galaxy, but the burst of X-rays came from another location, and was soon shown to arise from a different supernova, named SN 2008D. Researchers at the Italian National Institute for Astrophysics (INAF), the Max-Planck Institute for Astrophysics (MPA), ESO, and at various other institutions have observed the supernova at great length. The team is led by Paolo Mazzali of INAF's Padova Observatory and MPA. "What made this event very interesting," says Mazzali, "is that the X-ray signal was very

  9. Polysaccharide Degradation

    Science.gov (United States)

    Stone, Bruce A.; Svensson, Birte; Collins, Michelle E.; Rastall, Robert A.

    An overview of current and potential enzymes used to degrade polysaccharides is presented. Such depolymerases are comprised of glycoside hydrolases, glycosyl transferases, phosphorylases and lyases, and their classification, active sites and action patterns are discussed. Additionally, the mechanisms that these enzymes use to cleave glycosidic linkages is reviewed as are inhibitors of depolymerase activity; reagents which react with amino acid residues, glycoside derivatives, transition state inhibitors and proteinaceous inhibitors. The characterization of various enzymes of microbial, animal or plant origin has led to their widespread use in the production of important oligosaccharides which can be incorporated into food stuffs. Sources of polysaccharides of particular interest in this chapter are those from plants and include inulin, dextran, xylan and pectin, as their hydrolysis products are purported to be functional foods in the context of gastrointestinal health. An alternative use of degraded polysaccharides is in the treatment of disease. The possibility exists to treat bacterial exopolysaccharide with lyases from bacteriophage to produce oligosaccharides exhibiting bioactive sequences. Although this area is currently in its infancy the knowledge is available to investigate further.

  10. Soil bacteria for remediation of polluted soils

    Energy Technology Data Exchange (ETDEWEB)

    Springael, D.; Bastiaens, L.; Carpels, M.; Mergaey, M.; Diels, L.

    1996-09-18

    Soil bacteria, specifically adapted to contaminated soils, may be used for the remediation of polluted soils. The Flemish research institute VITO has established a collection of bacteria, which were isolated from contaminated areas. This collection includes microbacteria degrading mineral oils (Pseudomonas sp., Acinetobacter sp. and others), microbacteria degrading polycyclic aromatic hydrocarbons (genera Sphingomonas and Mycobacterium), microbacteria degrading polychlorobiphenyls (genus Ralstonia and strains related to beta-Proteobacteria), and metal resistant bacteria with plasmid borne resistances to Cd, Zn, Ni, Co, Cu, Hg, and Cr. Bench-scale reactors were developed to investigate the industrial feasibility of bioremediation. Batch Stirred Tank Reactors were used to evaluate the efficiency of oil degraders. Soils, contaminated with non-ferrous metals, were treated using a Bacterial Metal Slurry Reactor. It was found that the reduction of the Cd concentration may vary strongly from sample to sample: reduction factors vary from 95 to 50%. Is was shown that Cd contained in metallic sinter and biologically unavailable Cd could not be removed.

  11. Coulomb explosion of "hot spot"

    CERN Document Server

    Oreshkin, V I; Chaikovsky, S A; Artyomov, A P

    2016-01-01

    The study presented in this paper has shown that the generation of hard x rays and high-energy ions, which are detected in pinch implosion experiments, may be associated with the Coulomb explosion of the hot spot that is formed due to the outflow of the material from the pinch cross point. During the process of material outflow, the temperature of the hot spot plasma increases, and conditions arise for the plasma electrons to become continuously accelerated. The runaway of electrons from the hot spot region results in the buildup of positive space charge in this region followed by a Coulomb explosion. The conditions for the hot spot plasma electrons to become continuously accelerated have been revealed and estimates have been obtained for the kinetic energy of the ions generated by the Coulomb explosion.

  12. Evidence for Nearby Supernova Explosions

    CERN Document Server

    Benítez, N; Canelles, M; Benitez, Narciso; Maiz-Apellaniz, Jesus; Canelles, Matilde

    2002-01-01

    Supernova explosions are one of the most energetic--and potentially lethal--phenomena in the Universe. Scientists have speculated for decades about the possible consequences for life on Earth of a nearby supernova, but plausible candidates for such an event were lacking. Here we show that the Scorpius-Centaurus OB association, a group of young stars currently located at~130 parsecs from the Sun, has generated 20 SN explosions during the last 11 Myr, some of them probably as close as 40 pc to our planet. We find that the deposition on Earth of 60Fe atoms produced by these explosions can explain the recent measurements of an excess of this isotope in deep ocean crust samples. We propose that ~2 Myr ago, one of the SNe exploded close enough to Earth to seriously damage the ozone layer, provoking or contributing to the Pliocene-Pleistocene boundary marine extinction.

  13. Optimal dynamic detection of explosives

    Energy Technology Data Exchange (ETDEWEB)

    Moore, David Steven [Los Alamos National Laboratory; Mcgrane, Shawn D [Los Alamos National Laboratory; Greenfield, Margo T [Los Alamos National Laboratory; Scharff, R J [Los Alamos National Laboratory; Rabitz, Herschel A [PRINCETON UNIV; Roslund, J [PRINCETON UNIV

    2009-01-01

    The detection of explosives is a notoriously difficult problem, especially at stand-off distances, due to their (generally) low vapor pressure, environmental and matrix interferences, and packaging. We are exploring optimal dynamic detection to exploit the best capabilities of recent advances in laser technology and recent discoveries in optimal shaping of laser pulses for control of molecular processes to significantly enhance the standoff detection of explosives. The core of the ODD-Ex technique is the introduction of optimally shaped laser pulses to simultaneously enhance sensitivity of explosives signatures while reducing the influence of noise and the signals from background interferents in the field (increase selectivity). These goals are being addressed by operating in an optimal nonlinear fashion, typically with a single shaped laser pulse inherently containing within it coherently locked control and probe sub-pulses. With sufficient bandwidth, the technique is capable of intrinsically providing orthogonal broad spectral information for data fusion, all from a single optimal pulse.

  14. Explosive evaporation in solar flares

    Science.gov (United States)

    Fisher, George H.

    1987-01-01

    This paper develops a simple analytical model for the phenomenon of 'explosive evaporation' driven by nonthermal electron heating in solar flares. The model relates the electron energy flux and spectrum, plus details of the preflare atmosphere, to the time scale for explosive evaporation to occur, the maximum pressure and temperature to be reached, rough estimates for the UV pulse emission flux and duration, and the evolution of the blueshifted component of the soft X-ray lines. An expression is given for the time scale for buildup to maximum pressures and the onset of rapid motion of the explosively evaporating plasma. This evaporation can excite a rapid response of UV line and continuum emission. The emission lines formed in the plasma approach a given emissivity-weighted blueshift speed.

  15. Seismic coupling of nuclear explosions

    International Nuclear Information System (INIS)

    The new Giant Magnet Experimental Facility employing digital recording of explosion induced motion has been constructed and successfully tested. Particle velocity and piezoresistance gage responses can be measured simultaneously thus providing the capability for determining the multi-component stress-strain history in the test material. This capability provides the information necessary for validation of computer models used in simulation of nuclear underground testing, chemical explosion testing, dynamic structural response, earth penetration response, and etc. This report discusses fully coupled and cavity decoupled explosions of the same energy (0.622 kJ) were carried out as experiments to study wave propagation and attenuation in polymethylmethacrylate (PMMA). These experiments produced particle velocity time histories at strains from 2 x 10-3 to as low as 5.8 x 10-6. Other experiments in PMMA, reported recently by Stout and Larson8 provide additional particle velocity data to strains of 10-1

  16. Screening and identification of bacteria for organic pollutant degradation in sediment of marine cage fish farming area%网箱养殖沉积环境中有机污染物降解菌的筛选与鉴定

    Institute of Scientific and Technical Information of China (English)

    孟霞; 黄洪辉; 贾晓平; 古小莉

    2011-01-01

    This paper is aimed to present our study on the screening and identification of effective organic pollutant degrading bacteria in the sediment of a heavily organic polluted marine cage fish farm. As a matter of fact, the marine cage fish farming first began in Guangdong coastal waters of China at the end of 1970s, and it has grown dramatically during the last three decades and become one of the important marine aquaculture industries in China. However, marine cage fish farming generates high pollution loadings especially in the sea bottom, where the high sediment oxygen demand, anoxic sediments, production of toxic gases and decrease in benthic diversity may result. For bioremediation of polluted sediment environment in marine cage farm, six bacteria strains were isolated after 2 months of selective enrichment incubation under intermittent aeration condition from the sediment in the marine cage fish farm in Dapeng Ao Cove,east coast of Shenzhen City. Through the ability test for degradation to the liquid wild trash fish culture medium, four bacteria strains which were capable of degrading the organic trash fish pollutant rapidly and efficiently, were obtained. The 7 d incubation of biochemical oxygen demand (BOD7) were between 1 040- 1 140 mg/l, the 5 d incubation for the average CODMn removing rate ( 1 - COD5/COD0 ) were between 13.58% -46.9% and the biochemical degradation rate (BOD5/COD0) were between 81.56% -89.43%. The 5 d incubation for average CODMn degradation rate of pair-strain mixed bacteria was64.91% (6.51%, which was 2 times higher than that 30.60 (13.63% of single strain; and BOD5/COD0 were between 86.10% -89.13%. There were no obvious differences if compared with those of single strain. Sequence analysis based on partial 16S rDNA and performed by BLASTN and FASTA showed that 2 strains belonged to genus of Staphylococcus sp. and Halornonas sp. The other 2 strains maybe belonged to genus of Halomonas sp. and Pseudomonas sp

  17. Bleach vs. Bacteria

    Science.gov (United States)

    ... Articles | Inside Life Science Home Page Bleach vs. Bacteria By Sharon Reynolds Posted April 2, 2014 Your ... hypochlorous acid to help kill invading microbes, including bacteria. Researchers funded by the National Institutes of Health ...

  18. Evaluation of microbially-influenced degradation of massive concrete structures

    International Nuclear Information System (INIS)

    Many low level waste disposal vaults, both above and below ground, are constructed of concrete. One potential contributing agent to the destruction of concrete structures is microbially-influenced degradation (MID). Three groups of bacteria are known to create conditions that are conducive to destroying concrete integrity. They are sulfur oxidizing bacteria, nitrifying bacteria, and heterotrophic bacteria. Research is being conducted at the Idaho National Engineering Laboratory to assess the extent of naturally occurring microbially influenced degradation (MID) and its contribution to the deterioration of massive concrete structures. The preliminary steps to understanding the extent of MID, require assessing the microbial communities present on degrading concrete surfaces. Ultimately such information can be used to develop guidelines for preventive or corrective treatments for MID and aid in formulation of new materials to resist corrosion. An environmental study was conducted to determine the presence and activity of potential MID bacteria on degrading concrete surfaces of massive concrete structures. Scanning electron microscopy detected bacteria on the surfaces of concrete structures such as bridges and dams, where corrosion was evident. Enumeration of sulfur oxidizing thiobacilli and nitrogen oxidizing Nitrosomonas sp. and Nitrobacter sp. from surface samples was conducted. Bacterial community composition varied between sampling locations, and generally the presence of either sulfur oxidizers or nitrifiers dominated, although instances of both types of bacteria occurring together were encountered. No clear correlation between bacterial numbers and degree of degradation was exhibited

  19. Degradation of 2,4,6-trinitrotoluene by P. aeruginosa and characterization of some metabolites

    Directory of Open Access Journals (Sweden)

    Hatice Aysun Mercimek

    2015-03-01

    Full Text Available Degradation of 2,4,6-trinitrotoluene (TNT, a nitroaromatic explosive found in the soil and ground water, was investigated using Pseudomonas aeruginosa in in vitroexperiments. Biodegradable abilitiy of this bacteria was performed with 50 and 75 mg L−1 TNT concentrations in a defined liquid medium for 96 h time period. Treatment of TNT in supernatant samples taken at 0, 6, 12, 24, 48, 72 and 96 h from agitated vessels was followed by reverse-phase high-performance liquid chromatography (HPLC. In cultures supplemented with 50 and 75 mgL−1 TNT, after 96 h of incubation 46% and 59% reduction were detected respectively. Two metabolites as degradation intermediates with nitrite release into the medium, 2,4-dinitrotoluene (2,4-DNT and 4-aminodinitrotoluene (4-ADNT, were elucidated by thin layer chromatography (TLC and gas chromatography-mass spectrometry (GC-MS. These findings clearly indicate that Pseudomonas aeruginosa can be used in bioremediation of TNT contaminated sites.

  20. ICPP custom dissolver explosion recovery

    International Nuclear Information System (INIS)

    This report discusses the recovery from the February 9, 1991 small scale explosion in a custom processing dissolver at the Idaho Chemical Processing Plant. Custom processing is a small scale dissolution facility which processes nuclear material in an economical fashion. The material dissolved in this facility was uranium metal, uranium oxides, and uranium/fissium alloy in nitric acid. The paper explained the release of fission material, and the decontamination and recovery of the fuel material. The safety and protection procedures were also discussed. Also described was the chemical analysis which was used to speculate the most probable cause of the explosion. (MB)

  1. Explosive coalescence of magnetic islands

    Science.gov (United States)

    Tajima, T.; Sakai, J.-I.

    1986-01-01

    Simulation results from both the EM collisionless particle code and the MHD particle code reveal an explosive reconnection process associated with nonlinear evolution of the coalescence instability. The explosive coalescence is a self-similar process of magnetic collapse, and ensuing amplitude oscillations in the magnetic and electrostatic energies and temperatures are modeled by an equation of motion for the scale factor in the Sagdeev potential. This phenomenon may explain the rapid energy release of a certain class of solar flares during their impulsive phase.

  2. System for detecting nuclear explosions

    International Nuclear Information System (INIS)

    Apparatus for detecting underground nuclear explosions is described that is comprised of an antenna located in the dielectric substance of a deep waveguide in the earth and adapted to detect low frequency electromagnetic waves generated by a nuclear explosion, the deep waveguide comprising the high conductivity upper sedimentary layers of the earth, the dielectric basement rock, and a high conductivity layer of basement rock due to the increased temperature thereof at great depths, and means for receiving the electromagnetic waves detected by said antenna means

  3. Biodegradation of mixtures of pesticides by bacteria and white rot fungi

    OpenAIRE

    Gouma, Sofia

    2009-01-01

    The objective of this study was to examine the potential for degradation of mixtures of pesticides (chlorpyrifos, linuron, metribuzin) by a range of bacteria and fungi and to relate this capability to enzyme production and quantify the rates of degradation of the components of the mixture of xenobiotic compounds. Overall, although bacteria (19 Bacillus and 4 Pseudomonas species) exhibited tolerance to the individual and micture of pesticides actual degradation was not eviden...

  4. Protein degradation in bovine milk caused by Streptococcus agalactiae.

    Science.gov (United States)

    Åkerstedt, Maria; Wredle, Ewa; Lam, Vo; Johansson, Monika

    2012-08-01

    Streptococcus (Str.) agalactiae is a contagious mastitis bacterium, often associated with cases of subclinical mastitis. Different mastitis bacteria have been evaluated previously from a diagnostic point of view, but there is a lack of knowledge concerning their effect on milk composition. Protein composition is important in achieving optimal yield and texture when milk is processed to fermented products, such as cheese and yoghurt, and is thus of great economic value. The aim of this in vitro study was to evaluate protein degradation mainly caused by exogenous proteases originating from naturally occurring Str. agalactiae. The samples were incubated at 37°C to imitate degradation caused by the bacteria in the udder. Protein degradation caused by different strains of Str. agalactiae was also investigated. Protein degradation was observed to occur when Str. agalactiae was added to milk, but there were variations between strains of the bacteria. Caseins, the most economically important proteins in milk, were degraded up to 75% in milk inoculated with Str. agalactiae in relation to sterile ultra-high temperature (UHT) milk, used as control milk. The major whey proteins, α-lactalbumin and β-lactoglobulin, were degraded up to 21% in relation to the sterile control milk. These results suggest that different mastitis bacteria but also different strains of mastitis bacteria should be evaluated from a milk quality perspective to gain knowledge about their ability to degrade the economically important proteins in milk. PMID:22850579

  5. ENHANCED RHIZODEGRADATION OF MUNITIONS EXPLOSIVES TNT AND RDX BY SELECTED PLANT SPECIES

    Science.gov (United States)

    Soil and water contamination by the military munitions explosives TNT (2,4.6-trinitrotoluene)and RDX (1,3,5-hexahydro-1,3,5-trinitrotriazine)and their degradation products have raised many public health and environmental concerns. Phytoremediation techniques could provide a potential cost-effective...

  6. Suppression of Chemotactic Explosion by Mixing

    Science.gov (United States)

    Kiselev, Alexander; Xu, Xiaoqian

    2016-06-01

    Chemotaxis plays a crucial role in a variety of processes in biology and ecology. In many instances, processes involving chemical attraction take place in fluids. One of the most studied PDE models of chemotaxis is given by the Keller-Segel equation, which describes a population density of bacteria or mold which is attracted chemically to substance they secrete. Solutions of the Keller-Segel equation can exhibit dramatic collapsing behavior, where density concentrates positive mass in a measure zero region. A natural question is whether the presence of fluid flow can affect singularity formation by mixing the bacteria thus making concentration harder to achieve. In this paper, we consider the parabolic-elliptic Keller-Segel equation in two and three dimensions with an additional advection term modeling ambient fluid flow. We prove that for any initial data, there exist incompressible fluid flows such that the solution to the equation stays globally regular. On the other hand, it is well known that when the fluid flow is absent, there exists initial data leading to finite time blow up. Thus the presence of fluid flow can prevent the singularity formation. We discuss two classes of flows that have the explosion arresting property. Both classes are known as very efficient mixers. The first class are the relaxation enhancing (RE) flows of (Ann Math:643-674, 2008). These flows are stationary. The second class of flows are the Yao-Zlatos near-optimal mixing flows (Mixing and un-mixing by incompressible flows. arXiv:1407.4163, 2014), which are time dependent. The proof is based on the nonlinear version of the relaxation enhancement construction of (Ann Math:643-674, 2008), and on some variations of the global regularity estimate for the Keller-Segel model.

  7. Lead-free primary explosives

    Science.gov (United States)

    Huynh, My Hang V.

    2010-06-22

    Lead-free primary explosives of the formula (cat).sub.Y[M.sup.II(T).sub.X(H.sub.2O).sub.6-X].sub.Z, where T is 5-nitrotetrazolate, and syntheses thereof are described. Substantially stoichiometric equivalents of the reactants lead to high yields of pure compositions thereby avoiding dangerous purification steps.

  8. Explosion mitigation by water mist

    NARCIS (Netherlands)

    Wal, R. van der; Cargill, S.; Longbottom, A.; Rhijnsburger, M.P.M.; Erkel, A.G. van

    2010-01-01

    The internal explosion of an anti-ship missile or stored ammunition is a potentially catastrophic threat for a navy vessel. These events generally cause heavy blast loading and fragments to perforate the ship structure. As a solution to reduce the blast loading, the compartment can be filled with wa

  9. Explosion-proof scintillation counter

    International Nuclear Information System (INIS)

    It is noted that measuring devices used in the research works conducted with the help of radioactive isotopes on the chemical industry installations dangerous from the point of view of explosions, especially on the installations of the petrochemistry industry, must not limit the exploitation safety of these installations. The said especially concerns with the Geiger-Mueller type counters and scintillation detectors, located immediately in the places of measurements on the installations and supplied by high voltage power supply. It has been shown that electronic circuits for the detector's signals processing and obtaining working voltages can be located out of the explosive dangerous premices, for example, in the car trailer. Description is given of the device, with the help of which explosion safety is provided for the serially produced scintillation counter with forced ventilation (counter of the VA-S-50 type). Due to this device application, the exploitation parameters of the counter do not go down and there is no need for any changes in its design. Description is given of the device for external power supply and control of the counter which can swich off the power supply in the case of an accident, dangerous from the point of view of violation of the explosion safety conditions. The device is described for providing service to 10 measuring chanels, mounted on the car trailer

  10. Experimental approach to explosive nucleosynthesis

    International Nuclear Information System (INIS)

    Recent development of experimental studies on explosive nucleosynthesis, especially the rapid proton process and the primordial nucleosynthesis were discussed with a stress on unstable nuclei. New development in the experimental methods for the nuclear astrophysics is also discussed which use unstable nuclear beams. (author)

  11. Excavation research with chemical explosives

    International Nuclear Information System (INIS)

    The US Army Engineer Nuclear Cratering Group (NCG) is located at the Lawrence Radiation Laboratory in Livermore, California. NCG was established in 1962 and assigned responsibility for technical program direction of the Corps of Engineers Nuclear Excavation Research Program. The major part of the experimental program has been the execution of chemical explosive excavation experiments. In the past these experiments were preliminary to planned nuclear excavation experiments. The experience gained and technology developed in accomplishing these experiments has led to an expansion of NCG's research mission. The overall research and development mission now includes the development of chemical explosive excavation technology to enable the Corps of Engineers to more economically accomplish Civil Works Construction projects of intermediate size. The current and future chemical explosive excavation experiments conducted by NCG will be planned so as to provide data that can be used in the development of both chemical and nuclear excavation technology. In addition, whenever possible, the experiments will be conducted at the specific sites of authorized Civil Works Construction Projects and will be designed to provide a useful portion of the engineering structures planned in that project. Currently, the emphasis in the chemical explosive excavation program is on the development of design techniques for producing specific crater geometries in a variety of media. Preliminary results of two such experiments are described in this paper; Project Pre-GONDOLA III, Phase III, Reservoir Connection Experiment; and a Safety Calibration Series for Project TUGBOAT, a small boat harbor excavation experiment

  12. Turbulent Combustion in SDF Explosions

    Energy Technology Data Exchange (ETDEWEB)

    Kuhl, A L; Bell, J B; Beckner, V E

    2009-11-12

    A heterogeneous continuum model is proposed to describe the dispersion and combustion of an aluminum particle cloud in an explosion. It combines the gas-dynamic conservation laws for the gas phase with a continuum model for the dispersed phase, as formulated by Nigmatulin. Inter-phase mass, momentum and energy exchange are prescribed by phenomenological models. It incorporates a combustion model based on the mass conservation laws for fuel, air and products; source/sink terms are treated in the fast-chemistry limit appropriate for such gasdynamic fields, along with a model for mass transfer from the particle phase to the gas. The model takes into account both the afterburning of the detonation products of the C-4 booster with air, and the combustion of the Al particles with air. The model equations were integrated by high-order Godunov schemes for both the gas and particle phases. Numerical simulations of the explosion fields from 1.5-g Shock-Dispersed-Fuel (SDF) charge in a 6.6 liter calorimeter were used to validate the combustion model. Then the model was applied to 10-kg Al-SDF explosions in a an unconfined height-of-burst explosion. Computed pressure histories are compared with measured waveforms. Differences are caused by physical-chemical kinetic effects of particle combustion which induce ignition delays in the initial reactive blast wave and quenching of reactions at late times. Current simulations give initial insights into such modeling issues.

  13. Underground nuclear explosions and earthquakes

    International Nuclear Information System (INIS)

    The stages that have marked the ways towards the interdiction of nuclear tests are reviewed. Although seismographic equipments have been greatly improved, it is shown that a separate detection of underground nuclear explosions from natural seismic vibrations is still quite uneasy. The use of nuclear loads for civil engineering still makes it more complicate to apply a treatee of interdiction of nuclear tests

  14. Episodic Explosions in Interstellar Ices

    CERN Document Server

    Rawlings, J M C; Viti, S; Cecchi-Pestellini, C

    2013-01-01

    We present a model for the formation of large organic molecules in dark clouds. The molecules are produced in the high density gas-phase that exists immediately after ice mantles are explosively sublimated. The explosions are initiated by the catastrophic recombination of trapped atomic hydrogen. We propose that, in molecular clouds, the processes of freeze-out onto ice mantles, accumulation of radicals, explosion and then rapid (three-body) gas-phase chemistry occurs in a cyclic fashion. This can lead to a cumulative molecular enrichment of the interstellar medium. A model of the time-dependent chemistries, based on this hypothesis, shows that significant abundances of large molecular species can be formed, although the complexity of the species is limited by the short expansion timescale in the gas, immediately following mantle explosion. We find that this mechanism may be an important source of smaller organic species, such as methanol and formaldehyde, as well as precursors to bio-molecule formation. Most...

  15. Statistical estimation of loads from gas explosions

    OpenAIRE

    Høiset, Stian

    1998-01-01

    In the design of structures in the offshore and process industries, the possibility of a gas explosion must always be considered. This is usually incorporated by performing explosion simulations. However, estimations based on such calculations introduce uncertainties in the design process. The main uncertainties in explosion simulations are the assumption of the gas cloud,the location of the ignition point and the properties of the explosion simulator itself. In this thesis, we try to investi...

  16. Safe, in situ methodologies for the destruction of triacetone triperoxide and other explosive peroxides

    Science.gov (United States)

    Clausen, III, Christian (Inventor); Geiger, Cherie L. (Inventor); Sigman, Michael (Inventor); Fidler, Rebecca (Inventor)

    2011-01-01

    Triacetone triperoxide (TATP) and other explosives of the peroxide family are safely degraded in situ. Nano and micron size metal particles in an elemental state include pure iron and magnesium or iron and magnesium particles that are mechanically alloyed with palladium and nickel. The metal particles are used in both the elemental state and in emulsions that are made from water, a hydrophobic solvent, such as corn oil, and a food-grade nonionic surfactant. The neat metals and emulsified zero valent metals (EZVM) safely degrade TATP with the major degradation product being acetone. The EZVM system absorbs and dissolves the TATP into the emulsion droplets where TATP degradation occurs. EZVM systems are ideal for degrading dry TATP crystals that may be present on a carpet or door entrance. Both the neat metal system and the emulsion system (EZVM) degrade TATP in an aqueous slurry.

  17. 14 CFR 420.63 - Explosive siting.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Explosive siting. 420.63 Section 420.63... TRANSPORTATION LICENSING LICENSE TO OPERATE A LAUNCH SITE Responsibilities of a Licensee § 420.63 Explosive... the configuration of the launch site is in accordance with an explosive site plan, and that...

  18. 46 CFR 188.10-25 - Explosive.

    Science.gov (United States)

    2010-10-01

    ... release of gas and heat. Explosives are discussed in more detail in 49 CFR parts 171-179. ... 46 Shipping 7 2010-10-01 2010-10-01 false Explosive. 188.10-25 Section 188.10-25 Shipping COAST... Definition of Terms Used in This Subchapter § 188.10-25 Explosive. This term means a chemical compound...

  19. 33 CFR 401.67 - Explosive vessels.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Explosive vessels. 401.67 Section... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Dangerous Cargo § 401.67 Explosive vessels. A vessel carrying explosives, either Government or commercial, as defined in the Dangerous Cargo Act of the...

  20. Peptide conversations in Gram-positive bacteria.

    Science.gov (United States)

    Monnet, Véronique; Juillard, Vincent; Gardan, Rozenn

    2016-05-01

    Within Gram-positive bacteria, the expression of target genes is controlled at the population level via signaling peptides, also known as pheromones. Pheromones control a wide range of functions, including competence, virulence, and others that remain unknown. Until now, their role in bacterial gene regulation has probably been underestimated; indeed, bacteria are able to produce, by ribosomal synthesis or surface protein degradation, an extraordinary variety of peptides which are released outside bacteria and among which, some are pheromones that mediate cell-to-cell communication. The review aims at giving an updated overview of these peptide-dependant communication pathways. More specifically, it follows the whole peptide circuit from the peptide production and secretion in the extracellular medium to its interaction with sensors at bacterial surface or re-import into the bacteria where it plays its regulation role. In recent years, as we have accumulated more knowledge about these systems, it has become apparent that they are more complex than they first appeared. For this reason, more research on peptide-dependant pathways is needed to develop new strategies for controlling functions of interest in Gram-positive bacteria. In particular, such research could lead to alternatives to the use of antibiotics against pathogenic bacteria. In perspective, the review identifies new research questions that emerge in this field and that have to be addressed. PMID:25198780

  1. Effect of tourmaline on denitrification characteristics of hydrogenotrophic bacteria.

    Science.gov (United States)

    Wang, Wei; Jiang, Hongyan; Zhu, Guangquan; Song, Xueying; Liu, Xingyu; Qiao, Ya

    2016-03-01

    To improve the denitrification characteristics of anaerobic denitrifying bacteria and obviate the disadvantage of use of explosive hydrogen gas, tourmaline, a polar mineral, was added to the hydrogenotrophic denitrification system in this study. Microbial reduction of nitrate in the presence of tourmaline was evaluated to assess the promotion effect of tourmaline on nitrate biodegradation. The experiment results demonstrated that tourmaline speeded up the cultivation process of bacteria from 65 to 36 days. After domestication of the bacteria, nitrate (50 mg NO3 (-)-N L(-1)) was completely removed within 3 days in the combined tourmaline-bacteria system, and the generated nitrite was also removed within 8 days. The reduction rate in this system is higher relative to that in the bacteria system alone. Efficient removal of nitrate by tourmaline-supported anaerobic bacteria (without external hydrogen input) indicated that tourmaline might act as the sole hydrogen donor to sustain autotrophic denitrification. Besides the production of hydrogen, the promoted activity of anaerobic denitrifying bacteria might be caused by the change of water properties, e.g., the pH of aqueous solutions was altered to about 8.0 and the oxidation-reduction potential decreased by 62 % in the tourmaline system. The distinctive effects of tourmaline on bacteria were related to its electric properties. PMID:26545889

  2. Numerical computation algorithm of explosion equations and thermodynamics parameters of mine explosives

    Institute of Scientific and Technical Information of China (English)

    李守巨; 刘迎曦; 何翔; 周圆π

    2001-01-01

    A new numerical algorithm is presented to simulate the explosion reaction process of mine explosives based on the equation of state, the equation of mass conservation and thermodynamics balance equation of explosion products. With the affection of reversible reaction of explosion products to explosion reaction equations and thermodynamics parameters considered, the computer program has been developed. The computation values show that computer simulation results are identical with the testinq ones.

  3. Numerical computation algorithm of explosion equations and thermodynamics parameters of mine explosives

    Institute of Scientific and Technical Information of China (English)

    LI Shou-ju; LIU Ying-xi; HE Xiang; ZHOU Y uan-pai

    2001-01-01

    A new numerical algorithm is presented to simulate the explosion reacti on process of mine explosives based on the equation of state, the equation of ma ss conservation and thermodynamics balance equation of explosion products. With the affection of reversible reaction of explosion products to explosion reaction equations and thermodynamics parameters considered, the computer program has be en developed. The computation values show that computer simulation results are i dentical with the testing ones.

  4. 27 CFR 555.205 - Movement of explosive materials.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Movement of explosive..., FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage § 555.205 Movement of explosive materials. All explosive materials must be kept in locked magazines meeting...

  5. 27 CFR 555.32 - Special explosive devices.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Special explosive devices..., AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Administrative and Miscellaneous Provisions § 555.32 Special explosive devices. The Director may exempt certain explosive...

  6. Advanced Oxidation Degradation of Diclofenac

    International Nuclear Information System (INIS)

    Advanced oxidation/reduction processes (AO/RPs), utilize free radical reactions to directly degrade chemical contaminants as an alternative to traditional water treatment. This study reports the absolute rate constants for reaction of diclofenac sodium and the model compound (2, 6-dichloraniline) with the two major AO/RP radicals; the hydroxyl radical (•OH) and hydrated electron (e-aq). The bimolecular reaction rate constants (M-1 s-1) for diclofenac for •OH was (9.29 ± 0.11) x 109, and, for e- aq was (1.53 ± 0.03) x109. Preliminary degradation mechanisms are suggested based on product analysis using 60Co γ-irradiation and LC-MS for reaction by-product identification. The toxicity of products was evaluated using the Vibrio fischeri luminescent bacteria method. (author)

  7. Remediating explosive-contaminated groundwater by in situ redox manipulation (ISRM) of aquifer sediments.

    Science.gov (United States)

    Boparai, H K; Comfort, S D; Shea, P J; Szecsody, J E

    2008-03-01

    In situ chemical reduction of clays and iron oxides in subsurface environments is an emerging technology for treatment of contaminated groundwater. Our objective was to determine the efficacy of dithionite-reduced sediments from the perched Pantex Aquifer (Amarillo, TX) to abiotically degrade the explosives RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine), HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine), and TNT (2,4,6-trinitrotoluene). The effects of dithionite/buffer concentrations, sediments-solution ratios, and the contribution of Fe(II) were evaluated in batch experiments. Results showed that reduced Pantex sediments were highly effective in degrading all three high explosives. Degradation rates increased with increasing dithionite/buffer concentrations and soil to solution ratios (1:80-1:10 w/v). When Fe(II) was partially removed from the reduced sediments by washing (citrate-bicarbonate buffer), RDX degradation slowed, but degradation efficiency could be restored by adding Fe(II) back to the treated sediments and maintaining an alkaline pH. These data support in situ redox manipulation as a remedial option for treating explosive-contaminated groundwater at the Pantex site. PMID:18086486

  8. Fast neutron activation measurement of concealed explosives

    International Nuclear Information System (INIS)

    Spectra of 0.511 MeV γ-ray of nitrogen and 6.13 MeV γ-ray of oxygen and their ratio are measured by using two neutron sourses of different yield for explosive or non-explosive materials. Sensitivity and detecting speed are determined. A planar distribution of the explosive or non-explosive materials with different contents of nitrogen and oxygen is given. The whole design and security of detection method of fast neutron activation analysis system is discussed for concealed explosives

  9. Genomics of Probiotic Bacteria

    Science.gov (United States)

    O'Flaherty, Sarah; Goh, Yong Jun; Klaenhammer, Todd R.

    Probiotic bacteria from the Lactobacillus and Bifidobacterium species belong to the Firmicutes and the Actinobacteria phylum, respectively. Lactobacilli are members of the lactic acid bacteria (LAB) group, a broadly defined family of microorganisms that ferment various hexoses into primarily lactic acid. Lactobacilli are typically low G + C gram-positive species which are phylogenetically diverse, with over 100 species documented to date. Bifidobacteria are heterofermentative, high G + C content bacteria with about 30 species of bifidobacteria described to date.

  10. Learning Chemistry from Bacteria

    OpenAIRE

    Clardy, Jon

    2013-01-01

    Dr. Jon Clardy Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard University All animals, including humans, originated and evolved on a planet already teeming with bacteria, and the two kingdoms of life have been competing and cooperating through their joint history. Although bacteria are most familiar as pathogens, some bacteria produce small molecules that are essential for the biology of animals and other eukaryotes. This lecture explores some of...

  11. Spot test kit for explosives detection

    Energy Technology Data Exchange (ETDEWEB)

    Pagoria, Philip F; Whipple, Richard E; Nunes, Peter J; Eckels, Joel Del; Reynolds, John G; Miles, Robin R; Chiarappa-Zucca, Marina L

    2014-03-11

    An explosion tester system comprising a body, a lateral flow membrane swab unit adapted to be removeably connected to the body, a first explosives detecting reagent, a first reagent holder and dispenser operatively connected to the body, the first reagent holder and dispenser containing the first explosives detecting reagent and positioned to deliver the first explosives detecting reagent to the lateral flow membrane swab unit when the lateral flow membrane swab unit is connected to the body, a second explosives detecting reagent, and a second reagent holder and dispenser operatively connected to the body, the second reagent holder and dispenser containing the second explosives detecting reagent and positioned to deliver the second explosives detecting reagent to the lateral flow membrane swab unit when the lateral flow membrane swab unit is connected to the body.

  12. Hazards of explosives dusts: Particle size effects

    Energy Technology Data Exchange (ETDEWEB)

    Cashdollar, K L; Hertzberg, M; Green, G M

    1992-02-01

    At the request of the Department of Energy, the Bureau of Mines has investigated the hazards of military explosives dispersed as dust clouds in a 20-L test chamber. In this report, the effect of particle size for HMX, HNS, RDX, TATB, and TNT explosives dusts is studied in detail. The explosibility data for these dusts are also compared to those for pure fuel dusts. The data show that all of the sizes of the explosives dusts that were studied were capable of sustaining explosions as dust clouds dispersed in air. The finest sizes (<10 [mu]m) of explosives dusts were less reactive than the intermediate sizes (20 to 60 [mu]m); this is opposite to the particle size effect observed previously for the pure fuel dusts. At the largest sizes studied, the explosives dusts become somewhat less reactive as dispersed dust clouds. The six sizes of the HMX dust were also studied as dust clouds dispersed in nitrogen.

  13. Underwater explosions and cavitation phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Kamegai, M.

    1979-08-28

    Some aspects of underwater explosions and cavitation phenomena have been studied by using a thermodynamic equation of state for water and a one-dimensional Lagrangian hydrocode. The study showed that surface cavitation is caused by the main blast wave and a bubble pulse from rebound of a release wave moving toward the center of the exploding bubble. Gravity has little effect on the surface cavitation. In nuclear explosions the bubble is bounded by a two-phase region rather than a gas-water interface. The two-phase region cavitates as the bubble expands, changing the optical absorption coefficient by many orders of magnitude and significantly affecting the optical signature. In assessing cavitation damage, it is concluded that a water jet of unstable bubble collapse erodes solid walls. The study leads to suggestions for future research.

  14. Underwater explosions and cavitation phenomena

    International Nuclear Information System (INIS)

    Some aspects of underwater explosions and cavitation phenomena have been studied by using a thermodynamic equation of state for water and a one-dimensional Lagrangian hydrocode. The study showed that surface cavitation is caused by the main blast wave and a bubble pulse from rebound of a release wave moving toward the center of the exploding bubble. Gravity has little effect on the surface cavitation. In nuclear explosions the bubble is bounded by a two-phase region rather than a gas-water interface. The two-phase region cavitates as the bubble expands, changing the optical absorption coefficient by many orders of magnitude and significantly affecting the optical signature. In assessing cavitation damage, it is concluded that a water jet of unstable bubble collapse erodes solid walls. The study leads to suggestions for future research

  15. Waves from an underground explosion

    Science.gov (United States)

    Krymskii, A. V.; Lyakhov, G. M.

    1984-05-01

    The problem of the propagation of a spherical detonation wave in water-saturated soil was solved in [1, 2] by using a model of a liquid porous multicomponent medium with bulk viscosity. Experiments show that soils which are not water saturated are solid porous multicomponent media having a viscosity, nonlinear bulk compression limit diagrams, and irreversible deformations. Taking account of these properties, and using the model in [2], we have solved the problem of the propagation of a spherical detonation wave from an underground explosion. The solution was obtained by computer, using the finite difference method [3]. The basic wave parameters were determined at various distances from the site of the explosion. The values obtained are in good agreement with experiment. Models of soils as viscous media which take account of the dependence of deformations on the rate of loading were proposed in [4 7] also. In [8] a model was proposed corresponding to a liquid multicomponent medium with a variable viscosity.

  16. Explosive shielding by weak layers

    International Nuclear Information System (INIS)

    This paper presents the results of a series of computations which were carried out to determine the effect that a layer of extremely weak rock embedded in an otherwise strong rock matrix would have on the displacements and velocities which result from the detonation of a nearby explosive source. The motivation for the study was the apparently different measurements obtained on the Mission Cyber Nuclear Event when compared to results obtained from other events of equal yield in similar geologic media

  17. Nuclear explosions and their effects

    International Nuclear Information System (INIS)

    Nuclear weapons of all kinds and forms are a threat to mankind and earth due to the destruction, devastation and death resulting from them. The nuclear reactors and atomic power stations present in the world today will never be fully safe and secured, but it can be made safer in the future by constructing a new generation of nuclear reactors, relying on the auto security system. The article shows the different effects resulting from nuclear explosions. (author)

  18. Explosive Formulation Code Naming SOP

    Energy Technology Data Exchange (ETDEWEB)

    Martz, H. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-09-19

    The purpose of this SOP is to provide a procedure for giving individual HME formulations code names. A code name for an individual HME formulation consists of an explosive family code, given by the classified guide, followed by a dash, -, and a number. If the formulation requires preparation such as packing or aging, these add additional groups of symbols to the X-ray specimen name.

  19. Causes of the Cambrian Explosion.

    OpenAIRE

    Smith, M P; Harper, D.A.T.

    2013-01-01

    In the last decade, at least thirty individual hypotheses have been invoked to explain the Cambrian Explosion, ranging from starbursts in the Milky Way to intrinsic genomic reorganization and developmental patterning. It has been noted (1) that recent hypotheses fall into three categories: a) developmental/genetic, b) ecologic and c) abiotic environmental, with geochemical hypotheses forming an abundant and distinctive subset of the last. With a few notable exceptions, a significant majority ...

  20. Assessment of steam explosion impact on KNGR plant

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Moon Kyu; Park, Soo Yong; Park, Ik Kyu

    1999-03-01

    In present day light water reactors, if complete and prolonged failure of normal and emergency coolant flow occurs, fission product decay heat could cause melting of the reactor fuel. If the molten fuel mass accumulates it may relocate into reactor lower plenum and if the lower head fails it may eventually be brought into the reactor cavity. In such course of core melt relocation, the opportunity for fuel-coolant interactions (FCI) arises as the core melt relocates into water pool in reactor vessel as well as in reactor cavity and also, as a consequence of implementing accident management strategies involving water addition to a degraded or molten core. This report presents the methodologies and their results for assessment of steam explosion impact on KNGR plant integrity. Both in-vessel and ex-vessel phenomena are addressed. For in-vessel steam explosion, TRACER-II code is used for assessment of pressure load, while bounding calculations are applied for ex-vessel analysis. Analysis shows that the integrity of reactor pressure vessel lower head is preserved during the in-vessel event and the probability that the containment integrity is challenged is very low, even when ex-vessel steam explosion is allowed due to reactor vessel failure. (Author). 15 refs., 2 tabs., 4 figs.

  1. Nuclear Explosions 1945-1998

    International Nuclear Information System (INIS)

    The main part of this report is a list of nuclear explosions conducted by the United States, the Soviet Union, the United Kingdom, France, China, India and Pakistan in 1945-98. The list includes all known nuclear test explosions and is compiled from a variety of sources including officially published information from the USA, Russia and France. The details given for each explosion (date, origin time, location, yield, type, etc.) are often compiled from more than one source because the individual sources do not give complete information. The report includes a short background to nuclear testing and provides brief information on the Comprehensive Nuclear-Test-Ban Treaty and the verification regime now being established to verify compliance with the treaty. It also summarizes nuclear testing country by country. The list should be used with some caution because its compilation from a variety of sources means that some of the data could be incorrect. This report is the result of cooperation between the Defence Research Establishment (FOA) and the Stockholm International Peace Research Institute (SIPRI)

  2. Thermodynamic States in Explosion Fields

    Energy Technology Data Exchange (ETDEWEB)

    Kuhl, A L

    2010-03-12

    We investigate the thermodynamic states occurring in explosion fields from condensed explosive charges. These states are often modeled with a Jones-Wilkins-Lee (JWL) function. However, the JWL function is not a Fundamental Equation of Thermodynamics, and therefore cannot give a complete specification of such states. We use the Cheetah code of Fried to study the loci of states of the expanded detonation products gases from C-4 charges, and their combustion products air. In the Le Chatelier Plane of specific-internal-energy versus temperature, these loci are fit with a Quadratic Model function u(T), which has been shown to be valid for T < 3,000 K and p < 1k-bar. This model is used to derive a Fundamental Equation u(v,s) for C-4. Given u(v,s), one can use Maxwell's Relations to derive all other thermodynamic functions, such as temperature: T(v,s), pressure: p(v,s), enthalpy: h(v,s), Gibbs free energy: g(v,s) and Helmholz free energy: f(v,s); these loci are displayed in figures for C-4. Such complete equations of state are needed for numerical simulations of blast waves from explosive charges, and their reflections from surfaces.

  3. Nuclear Explosions 1945-1998

    Energy Technology Data Exchange (ETDEWEB)

    Bergkvist, Nils-Olov; Ferm, Ragnhild

    2000-07-01

    The main part of this report is a list of nuclear explosions conducted by the United States, the Soviet Union, the United Kingdom, France, China, India and Pakistan in 1945-98. The list includes all known nuclear test explosions and is compiled from a variety of sources including officially published information from the USA, Russia and France. The details given for each explosion (date, origin time, location, yield, type, etc.) are often compiled from more than one source because the individual sources do not give complete information. The report includes a short background to nuclear testing and provides brief information on the Comprehensive Nuclear-Test-Ban Treaty and the verification regime now being established to verify compliance with the treaty. It also summarizes nuclear testing country by country. The list should be used with some caution because its compilation from a variety of sources means that some of the data could be incorrect. This report is the result of cooperation between the Defence Research Establishment (FOA) and the Stockholm International Peace Research Institute (SIPRI)

  4. Seismic discrimination of nuclear explosions

    International Nuclear Information System (INIS)

    The monitoring of underground nuclear explosions has been discussed for over 30 years in connection with verification of test ban treaties, and monitoring is also one of the basic ways to learn about nuclear weapons development in different countries. Explosion monitoring is thus an important technical exercise, occasionally attracting attention for high-level policymakers and generating front page news. The underlying issues here are related to the uses of nuclear weapons, their cost, and the strategic capabilities and vulnerabilities of the superpowers and other countries. Because these are some of the largest and most contentious questions of our time, arguments sometimes spill over from the policy arena into the technical subject of monitoring capability itself. As a side effect of the debate, geophysics (especially seismology) continues to be shaped by significant funding for research and development in verification/monitoring technologies. New funds at the level of about $30 million came into seismic monitoring programs in the United States in 1989. In this paper, the authors review the history of nuclear testing and test ban negotiations, introduce some basic terminology, give examples of detection capability, describe characteristics of different seismic sources and methods of explosion identification, and briefly review different evasion scenarios. The authors conclude with a summary statement of identification capability and its implication for future possibilities in verifying new nuclear testing limitations

  5. Fish kill from underwater explosions

    Science.gov (United States)

    Stuart, David J.

    1962-01-01

    The U.S. Geological Survey has used 23 different shotpoints during two seasons of field work in our seismic study of crustal structure in western United States. Without exception, it has been found that under-water shotpoints result in a more efficient conversion of explosive energy into seismic energy than do drilled-hole shotpoints. This experience, together with elimination of drilling costs, has led to the use of underwater shotpoints wherever possible. Three of the 23 shotpoints were in the Pacific Ocean, and for these we have no detailed information on the fish kill. Another six shotpoints were located in inland bodies of water. These are: * Soda Lake near Fallon, Nevada * Mono Lake near Lee Vining, California * Lake Mead near Boulder City, Nevada * Shasta Lake near Redding, California * C.J. Strike Reservoir near Bruneau, Idaho * Lucky Peak Reservoir near Boise, Idaho The 22 high-explosive charges, weighing a total of 95,100 pounds, that were fired in lakes containing fish life resulted in the known death of 2,413 game fish with a total weight of 759 pounds. The average mortality was 110 game fish or 34.5 pounds of game fish killed per average shot of 4,325 pounds of high-explosives.

  6. Immobilization of Estrogen-degrading Bacteria to Remove the 17β-estradiol and Diethylstilbestrol from Polluted Water and Cow Dung%固定化菌剂对污水和牛粪中雌二醇和己烯雌酚的去除作用

    Institute of Scientific and Technical Information of China (English)

    李欣; 凌婉婷; 刘静娴; 孙敏霞; 高彦征; 刘娟

    2015-01-01

    针对雌二醇(E2)和己烯雌酚(DES)易在污水和牛粪富集的问题,制备了具有去除 E2和 DES 功能的固定化菌剂,并研究了其对污水和牛粪中 E2与 DES 的去除作用.以 E2降解菌 Rhodococcus sp. JX-2与 DES 降解菌 Serratia sp. S 为供试菌,主要通过正交试验确定了固定化菌剂包埋方法,比较了固定化菌剂﹑游离态菌剂﹑空白小球对 E2与 DES 的去除效能,并分析了菌剂用量﹑ pH﹑含水量﹑翻堆时间对菌剂去除污水和牛粪中 E2和 DES 的影响.结果表明,菌剂制备的最佳固定化条件为菌株 JX-2与菌株 S 菌悬液体积比为1:1,海藻酸钠质量分数5℅,菌胶比为1:2,CaCl2.2H2 O 质量分数4℅.固定化菌剂对溶液中初始浓度为2 mg.L -1 E2和 DES 的去除率分别达99.42℅和84.59℅.去除污水中 E2和 DES 的最佳固定化菌剂用量为300 g.L -1,pH 值为5.0~6.0,能完全去除 DES,E2去除率为95.85℅;去除牛粪中 E2和 DES 的最佳固定化菌剂用量为600 g.kg -1,牛粪含水量为70℅,翻堆时间间隔为12 h,能完全去除 E2,DES 去除率为97.41℅.%Estradiol (E2) and diethylstilbestrol (DES) can be enriched in sewage and cow dung, posing serious threats to human and ecological health. Strain Rhodococcus sp. JX-2 and strain Serratia sp. S, which could degrade 17β-estradiol and diethylstilbestrol, respectively, were immobilized by alginate and then added into sewage and cow dung to remove E2 and DES. The immobilization was determined by orthogonal experiment, and the removal of E2 and DES from sewage and cow dung was compared between treatments of immobilized bacteria, free bacteria and control without bacteria. The influencing factors including inoculation amount, pH value, moisture content, turning time on the removal of E2 and DES were investigated. The optimal conditions of JX-2 and S immobilization were as follows: Strain JX-2: strain S (V/ V) 1: 1, alginate concentration 5℅ , calcium chloride concentration 4

  7. Degradation of BTEX by anaerobic bacteria: physiology and application

    OpenAIRE

    Weelink, S.A.B.; Eekert, van, M.H.A.; Stams, A.J.M.

    2010-01-01

    Pollution of the environment with aromatic hydrocarbons, such as benzene, toluene, ethylbenzene and xylene (so-called BTEX) is often observed. The cleanup of these toxic compounds has gained much attention in the last decades. In situ bioremediation of aromatic hydrocarbons contaminated soils and groundwater by naturally occurring microorganisms or microorganisms that are introduced is possible. Anaerobic bioremediation is an attractive technology as these compounds are often present in the a...

  8. Degradation of BTEX by anaerobic bacteria: physiology and application

    NARCIS (Netherlands)

    Weelink, S.A.B.; Eekert, van M.H.A.; Stams, A.J.M.

    2010-01-01

    Pollution of the environment with aromatic hydrocarbons, such as benzene, toluene, ethylbenzene and xylene (so-called BTEX) is often observed. The cleanup of these toxic compounds has gained much attention in the last decades. In situ bioremediation of aromatic hydrocarbons contaminated soils and gr

  9. Degradation of benzene and other aromatic hydrocarbons by anaerobic bacteria

    OpenAIRE

    Weelink, S.A.B.

    2008-01-01

    Accidental spills, industrial discharges and gasoline leakage from underground storage tanks have resulted in serious pollution of the environment with monoaromatic hydrocarbons, such as benzene, toluene, ethylbenzene and xylene (so-called BTEX). High concentrations of BTEX have been detected in soils, sediments and groundwater. The mobility and toxicity of the BTEX compounds are of major concern. In situ bioremediation of BTEX by using naturally occurring microorganisms or introduced microor...

  10. Degradation of benzene and other aromatic hydrocarbons by anaerobic bacteria

    NARCIS (Netherlands)

    Weelink, S.A.B.

    2008-01-01

    Accidental spills, industrial discharges and gasoline leakage from underground storage tanks have resulted in serious pollution of the environment with monoaromatic hydrocarbons, such as benzene, toluene, ethylbenzene and xylene (so-called BTEX). High concentrations of BTEX have been detected in soi

  11. Screening and Isolation of Gasoline Degrading Bacteria by Enrichment Technique

    OpenAIRE

    G. Srinikethan; Madhumathi; Smitha Hegde

    2010-01-01

    Gasoline a, major petroleum hydrocarbon used frequently in automobiles is a complex mixture of aliphatic, aromatic and allicyclic hydrocarbons. The general population is exposed to gasoline or gasoline vapors during automobile refueling procedures, refueling of gasoline-powered equipment and using the gasoline-contaminated surface water or groundwater. Biodegradation of gasoline holds a promising approach for handling the problems due to gasoline pollution. In the present study the soil sampl...

  12. Degradation of juvenogens by termites and soil bacteria

    Czech Academy of Sciences Publication Activity Database

    Brabcová, Jana; Hanus, Robert; Tykva, Richard; Vlasáková, Věra; Černý, Bohuslav; Wimmer, Zdeněk; Zarevúcka, Marie

    2011-01-01

    Roč. 101, č. 2 (2011), s. 103-108. ISSN 0048-3575 R&D Projects: GA MŠk 2B06024 Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z50380511 Keywords : juvenogen * Reticulitermes flavipes * Bacillus sp Subject RIV: CC - Organic Chemistry Impact factor: 1.713, year: 2011

  13. Explosion risks linked to red oils in the spent fuels reprocessing plants

    International Nuclear Information System (INIS)

    This paper presents the risk of explosion associated with reactions between tributyl phosphate (TBP) and its degradation products and nitrates from nitric acid or associated with heavy metals (uranium and plutonium); These reactions may lead to the formation of unstable compounds known as 'red oils'. The feedback explosions linked to the formation of such compounds occurring in spent fuel reprocessing plants round the world, is briefly discussed. The main measures to control these risks, implemented in French factories concerned are also presented. (N.C.)

  14. Data base of chemical explosions in Kazakhstan

    Energy Technology Data Exchange (ETDEWEB)

    Demin, V.N. [National Nuclear Center of Republic of Kazakhstan Institute of Geophysical Researches (Kazakhstan); Malahova, M.N. [National Nuclear Center of Republic of Kazakhstan Institute of Geophysical Researches (Kazakhstan); Martysevich, P.N. [National Nuclear Center of Republic of Kazakhstan Institute of Geophysical Researches (Kazakhstan); Mihaylova, N.N. [National Nuclear Center of Republic of Kazakhstan Institute of Geophysical Researches (Kazakhstan); Nurmagambetov, A. [National Nuclear Center of Republic of Kazakhstan Institute of Geophysical Researches (Kazakhstan); Kopnichev, Yu.F. D. [National Nuclear Center of Republic of Kazakhstan Institute of Geophysical Researches (Kazakhstan); Edomin, V.I. [National Nuclear Center of Republic of Kazakhstan Institute of Geophysical Researches (Kazakhstan)

    1996-12-01

    Within the bounds of this report, the following works were done: (1) Information about explosion quarries, located in Southern, Eastern and Northern Kasakstan was summarized. (2) The general information about seismicity of areas of location of explosion quarries was adduced. (3) The system of observation and seismic apparatus, recording the local earthquakes and quarry explosions at the territory of Kazakstan were described. (4) Data base of quarry explosions, that were carried out in Southern, Eastern and Northern Kazakstan during 1995 and first half of 1996 year was adduced. (5) Upon the data of registration of explosions in Southern Kazakstan the correlative dependences between power class of explosions and summary weight of charge were constructed. (6) Seismic records of quarry explosions were adduced. It is necessary to note, that the collection of data about quarry explosions in Kazakstan in present time is very difficult task. Organizations, that makes these explosions, are always suffering reorganizations and sometimes it is actually impossible to receive all the necessary information. Some quarries are situated in remote, almost inaccessible regions, and within the bounds of supplier financing not the every quarry was in success to visit. So the present data base upon the chemical explosions for 1995 is not full and in further it`s expansion is possible.

  15. Aerobic Anoxygenic Phototrophic Bacteria

    OpenAIRE

    Yurkov, Vladimir V.; Beatty, J. Thomas

    1998-01-01

    The aerobic anoxygenic phototrophic bacteria are a relatively recently discovered bacterial group. Although taxonomically and phylogenetically heterogeneous, these bacteria share the following distinguishing features: the presence of bacteriochlorophyll a incorporated into reaction center and light-harvesting complexes, low levels of the photosynthetic unit in cells, an abundance of carotenoids, a strong inhibition by light of bacteriochlorophyll synthesis, and the inability to grow photosynt...

  16. Rapid Isolation of Phenol Degrading Bacteria by Fourier Transform Inf rared (FTIR) Spectroscopy%利用衰减全反射傅里叶红外光谱(ATR-FTIR)技术快速筛选可降解苯酚菌株

    Institute of Scientific and Technical Information of China (English)

    李霏; 宋文军; 魏纪平; 王素英; 刘崇基

    2015-01-01

    Phenol is an important chemical engineering material and ubiquitous in industry wastewater ,its ex-istence has become a thorny issue in many developed and developing country .More and more stringent stand-ards for effluent all over the world with human realizing the toxicity of phenol have been announced .Many ad-vanced biological methods are applied to industrial wastewater treatment with low cost ,high efficiency and no secondary pollution ,but the screening of function microorganisms is certain cumbersome process .In our study a rapid procedure devised for screening bacteria on solid medium can degrade phenol coupled with attenuated total reflection fourier transform infrared (ATR-FTIR) which is a detection method has the characteristics of efficient ,fast ,high fingerprint were used .Principal component analysis (PCA) is a method in common use to extract fingerprint peaks effectively ,it couples with partial least squares (PLS) statistical method could estab-lish a credible model .The model we created using PCA-PLS can reach 99.5% of coefficient determination and validation data get 99.4% ,which shows the promising fitness and forecasting of the model .The high fitting model is used for predicting the concentration of phenol at solid medium where the bacteria were grown .The highly consistent result of two screening methods ,solid cultural with ATR-FTIR detected and traditional liq-uid cultural detected by GC methods ,suggests the former can rapid isolate the bacteria which can degrade sub-strates as well as traditional cumbersome liquid cultural method .Many hazardous substrates widely existed in industry wastewater ,most of them has specialize fingerprint peaks detected by ATR-FTIR ,thereby this detec-ted method could be used as a rapid detection for isolation of functional microorganisms those can degrade many other toxic substrates .%苯酚是一种重要的化工原料并广泛存在于工业废水中,随着各国对苯酚生物毒性的认识,排放

  17. Bacterial degradation of monocyclic aromatic amines

    Directory of Open Access Journals (Sweden)

    Pankaj Kumar Arora

    2015-08-01

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

  18. Degradable Magnetic Composites for Minimally Invasive Interventions: Device Fabrication, Targeted Drug Delivery, and Cytotoxicity Tests.

    Science.gov (United States)

    Peters, Christian; Hoop, Marcus; Pané, Salvador; Nelson, Bradley J; Hierold, Christofer

    2016-01-20

    Superparamagnetic nanoparticles and a functional, degradable polymer matrix based on poly(ethylene glycol) are combined to enable fully degradable magnetic microdevices for minimally invasive biomedical applications. A bioinspired helical microrobot platform mimicking Escherichia coli bacteria is fabricated and actuated using weak rotating magnetic fields. Locomotion based on corkscrew propulsion, targeted drug delivery, and low-degradation-product cytotoxicity are demonstrated. PMID:26603856

  19. Evaluation of the sensitivity of freshwater organisms used in toxicity tests of wastewater from explosives company.

    Science.gov (United States)

    Ribeiro, Elaine Nolasco; da Silva, Flávio Teixeira; de Paiva, Teresa Cristina Brazil

    2012-10-01

    Explosives industries are a source of toxic discharge. The aim of this study was to compare organisms sensitivity (Daphnia similis, Danio rerio, Escherichia coli and Pseudomonas putida) in detecting acute toxicity in wastewater from two explosives, 2,4,6-TNT (TNT) and nitrocellulose. The samples were collected from an explosives company in the Paraiba Valley, São Paulo, Brazil. The effluents from TNT and nitrocellulose production were very toxic for tested organisms. Statistical tests indicated that D. similis and D. rerio were the most sensitive organisms for toxicity detection in effluents from 2,4,6-TNT and nitrocellulose production. The P. putida bacteria was the organism considered the least sensitive in indicating toxicity in effluents from nitrocellulose. PMID:22872378

  20. Metallization of bacteria cells

    Institute of Scientific and Technical Information of China (English)

    LI; Xiangfeng; (黎向锋); LI; Yaqin; (李雅芹); CAI; Jun; (蔡军); ZHANG; Deyuan; (张德远)

    2003-01-01

    Bacteria cells with different standard shapes are well suited for use as templates for the fabrication of magnetic and electrically conductive microstructures. In this paper, metallization of bacteria cells is demonstrated by an electroless deposition technique of nickel-phosphorus initiated by colloid palladium-tin catalyst on the surfaces of Citeromyces matritensis and Bacillus cereus. The activated and metallized bacteria cells have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction analysis (XRD). Results showed that both Citeromyces matritensis and Bacillus cereus had no deformation in shape after metallization; the metallized films deposited on the surfaces of bacteria cells are homogeneous in thickness and noncrystalline in phase structure. The kinetics of colloid palladium-tin solution and electroless plating on bacteria cells is discussed.

  1. Poplar Lignin Decomposition by Gram-Negative Aerobic Bacteria

    OpenAIRE

    Odier, E.; Janin, G.; Monties, B

    1981-01-01

    Eleven gram-negative aerobic bacteria (Pseudomonadaceae and Neisseriaceae) out of 122 soil isolates were selected for their ability to assimilate poplar dioxane lignin without a cosubstrate. Dioxane lignin and milled wood lignin degradation rates ranged between 20 and 40% of initial content after 7 days in mineral medium, as determined by a loss of absorbance at 280 nm; 10 strains could degrade in situ lignin, as evidenced by the decrease of the acetyl bromide lignin content of microtome wood...

  2. Evaluation by electron microscopy and anaerobic culture of types of rumen bacteria associated with digestion of forage cell walls.

    OpenAIRE

    Akin, D E

    1980-01-01

    Different morphological types of rumen bacteria which degraded cell walls of forage grasses with various in vitro digestibilities were evaluated with electron microscopy. The majority of these bacteria (i.e., about 70% or more) consisted of two distinct types: (i) encapsulated cocci and (ii) irregularly shaped bacteria, resembling major fiber digesters found in the rumen. Each type was capable of degrading structurally intact cell walls. Differences (P less than or equal to 0.02) in the perce...

  3. Explosives Detection: Exploitation of the Physical Signatures

    Science.gov (United States)

    Atkinson, David

    2010-10-01

    Explosives based terrorism is an ongoing threat that is evolving with respect to implementation, configuration and materials used. There are a variety of devices designed to detect explosive devices, however, each technology has limitations and operational constraints. A full understanding of the signatures available for detection coupled with the array of detection choices can be used to develop a conceptual model of an explosives screening operation. Physics based sensors provide a robust approach to explosives detection, typically through the identification of anomalies, and are currently used for screening in airports around the world. The next generation of detectors for explosives detection will need to be more sensitive and selective, as well as integrate seamlessly with devices focused on chemical signatures. An appreciation for the details of the physical signature exploitation in cluttered environments with time, space, and privacy constraints is necessary for effective explosives screening of people, luggage, cargo, and vehicles.

  4. Explosive Surface Hardening of Austenitic Stainless Steel

    Science.gov (United States)

    Kovacs-Coskun, T.

    2016-04-01

    In this study, the effects of explosion hardening on the microstructure and the hardness of austenitic stainless steel have been studied. The optimum explosion hardening technology of austenitic stainless steel was researched. In case of the explosive hardening used new idea mean indirect hardening setup. Austenitic stainless steels have high plasticity and can be easily cold formed. However, during cold processing the hardening phenomena always occurs. Upon the explosion impact, the deformation mechanism indicates a plastic deformation and this deformation induces a phase transformation (martensite). The explosion hardening enhances the mechanical properties of the material, includes the wear resistance and hardness. In case of indirect hardening as function of the setup parameters specifically the flayer plate position the hardening increased differently. It was find a relationship between the explosion hardening setup and the hardening level.

  5. Can soil bacteria solve PCB disposal problems with bioremediation

    International Nuclear Information System (INIS)

    A study headed by scientists at Laval University in Quebec City is designed to turn common soil bacteria into polychlorinated biphenyl (PCB) neutralizers. There are currently four natural enzymes that can give bacteria the power they need to break down 30 or 40 of the 209 compounds which make up PCBs. The objective of this research project is to explore the enzymatic mechanisms that enable bacteria to break down some PCB compounds but not others. The research team hopes to be able to modify the enzymes so that they will be able to degrade many other toxic PCB compounds, and other toxic materials such as polycyclic aromatic hydrocarbons, dioxins and furans. 1 fig

  6. Biodegradation of explosives mixture in soil under different water-content conditions.

    Science.gov (United States)

    Sagi-Ben Moshe, S; Dahan, O; Weisbrod, N; Bernstein, A; Adar, E; Ronen, Z

    2012-02-15

    Soil redox potential plays a key role in the rates and pathways of explosives degradation, and is highly influenced by water content and microbial activity. Soil redox potential can vary significantly both temporally and spatially in micro-sites. In this study, when soil water content increased, the redox potential decreased, and there was significant enhancement in the biodegradation of a mixture of three explosives. Whereas TNT degradation occurred under both aerobic and anaerobic conditions, RDX and HMX degradation occurred only when water content conditions resulted in a prolonged period of negative redox potential. Moreover, under unsaturated conditions, which are more representative of real environmental conditions, the low redox potential, even when measured for temporary periods, was sufficient to facilitate anaerobic degradation. Our results clearly indicate a negative influence of TNT on the biodegradation of RDX and HMX, but this effect was less pronounced than that found in previous slurry batch experiments: this can be explained by a masking effect of the soil in the canisters. Fully or partially saturated soils can promote the existence of micro-niches that differ considerably in their explosives concentration, microbial community and redox conditions. PMID:22226717

  7. Stellar Explosions: Hydrodynamics and Nucleosynthesis

    Science.gov (United States)

    José, Jordi

    2015-12-01

    Stars are the main factories of element production in the universe through a suite of complex and intertwined physical processes. Such stellar alchemy is driven by multiple nuclear interactions that through eons have transformed the pristine, metal-poor ashes leftover by the Big Bang into a cosmos with 100 distinct chemical species. The products of stellar nucleosynthesis frequently get mixed inside stars by convective transport or through hydrodynamic instabilities, and a fraction of them is eventually ejected into the interstellar medium, thus polluting the cosmos with gas and dust. The study of the physics of the stars and their role as nucleosynthesis factories owes much to cross-fertilization of different, somehow disconnected fields, ranging from observational astronomy, computational astrophysics, and cosmochemistry to experimental and theoretical nuclear physics. Few books have simultaneously addressed the multidisciplinary nature of this field in an engaging way suitable for students and young scientists. Providing the required multidisciplinary background in a coherent way has been the driving force for Stellar Explosions: Hydrodynamics and Nucleosynthesis. Written by a specialist in stellar astrophysics, this book presents a rigorous but accessible treatment of the physics of stellar explosions from a multidisciplinary perspective at the crossroads of computational astrophysics, observational astronomy, cosmochemistry, and nuclear physics. Basic concepts from all these different fields are applied to the study of classical and recurrent novae, type I and II supernovae, X-ray bursts and superbursts, and stellar mergers. The book shows how a multidisciplinary approach has been instrumental in our understanding of nucleosynthesis in stars, particularly during explosive events.

  8. Explosive site percolation and finite size hysteresis

    OpenAIRE

    Bastas, Nikolaos; Kosmidis, Kosmas; Argyrakis, Panos

    2011-01-01

    We report the critical point for site percolation for the "explosive" type for 2D square lattices using Monte Carlo simulations and compare it to the classical well known percolation. We use similar algorithms as have been recently reported for bond percolation and networks. We calculate the "explosive" site percolation threshold as $p_c=0.695$ and we find evidence that "explosive" site percolation surprisingly may belong to a different universality class than bond percolation on lattices, pr...

  9. New Dark Matter Detector using Nanoscale Explosives

    OpenAIRE

    Lopez, Alejandro; Drukier, Andrzej; Freese, Katherine; Kurdak, Cagliyan; Tarle, Gregory

    2014-01-01

    We present nanoscale explosives as a novel type of dark matter detector and study the ignition properties. When a Weakly Interacting Massive Particle WIMP from the Galactic Halo elastically scatters off of a nucleus in the detector, the small amount of energy deposited can trigger an explosion. For specificity, this paper focuses on a type of two-component explosive known as a nanothermite, consisting of a metal and an oxide in close proximity. When the two components interact they undergo a ...

  10. Analysis of TROI-13 Steam Explosion Experiment

    OpenAIRE

    Mitja Uršič; Matjaž Leskovar

    2008-01-01

    The prediction of steam explosion inducing loads in nuclear power plants must be based on results of experimental research programmes and on simulations using validated fuel-coolant interaction codes. In this work, the TROI-13 steam explosion experiment was analysed with the fuel-coolant interaction MC3D computer code. The TROI-13 experiment is one of several experiments performed in the TROI research program and resulted in a spontaneous steam explosion using corium melt. First, the TROI-13 ...

  11. Is a Cambrian Explosion Coming for Robotics?

    OpenAIRE

    Gill A. Pratt

    2015-01-01

    About half a billion years ago, life on earth experienced a short period of very rapid diversification called the "Cambrian Explosion." Many theories have been proposed for the cause of the Cambrian Explosion, one of the most provocative being the evolution of vision, allowing animals to dramatically increase their ability to hunt and find mates. Today, technological developments on several fronts are fomenting a similar explosion in the diversification and applicability of robotics. Many of ...

  12. The gas dynamics of explosions

    CERN Document Server

    Lee,\tJohn H S

    2016-01-01

    Explosions, and the non-steady shock propagation associated with them, continue to interest researchers working in different fields of physics and engineering (such as astrophysics and fusion). Based on the author's course in shock dynamics, this book describes the various analytical methods developed to determine non-steady shock propagation. These methods offer a simple alternative to the direct numerical integration of the Euler equations and offer a better insight into the physics of the problem. Professor Lee presents the subject systematically and in a style that is accessible to graduate students and researchers working in shock dynamics, combustion, high-speed aerodynamics, propulsion and related topics.

  13. Explosive demolition of activated concrete

    International Nuclear Information System (INIS)

    This paper describes the removal of a radiologically contaminated concrete pad. This pad was removed during 1979 by operating personnel under the direction of the Waste Management Program of EG and G Idaho, Inc. The concrete pad was the foundation for the Organic Moderated Reactor Experiment (OMRE) reactor vessel located at the Idaho National Engineering Laboratory (INEL). The pad consisted of a cylindrical concrete slab 15 ft in diameter, 2 ft thick, and reinforced with steel bar. It was poured directly onto basalt rocks approximately 20 ft below grade. The entire pad contained induced radioactivity and was therefore demolished, boxed, and buried rather than being decontaminated. The pad was demolished by explosive blasting

  14. 75 FR 1085 - Commerce in Explosives; List of Explosive Materials (2009R-18T)

    Science.gov (United States)

    2010-01-08

    ... 31, 2008 (Docket No. ATF 28N, 73 FR 80428). Notice of List of Explosive Materials Pursuant to 18 U.S... tetrazene hydrate]. Tetrazole explosives. Tetryl . Tetrytol. Thickened inorganic oxidizer salt...

  15. 75 FR 70291 - Commerce in Explosives; List of Explosive Materials (2010R-27T)

    Science.gov (United States)

    2010-11-17

    ..., 75 FR 1085). Notice of List of Explosive Materials Pursuant to 18 U.S.C. 841(d) and 27 CFR 555.23, I.... Tetrazene [tetracene, tetrazine, 1(5-tetrazolyl)-4-guanyl tetrazene hydrate]. Tetrazole explosives....

  16. 77 FR 58410 - Commerce in Explosives; List of Explosive Materials (2012R-10T)

    Science.gov (United States)

    2012-09-20

    ..., 76 FR 64974). Notice of List of Explosive Materials Pursuant to 18 U.S.C. 841(d) and 27 CFR 555.23, I.... Tetrazene [tetracene, tetrazine, 1(5-tetrazolyl)-4-guanyl tetrazene hydrate]. Tetrazole explosives....

  17. High Explosives Research and Development (HERD) Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The purpose is to provide high explosive formulation, chemical analysis, safety and performance testing, processing, X-ray, quality control and loading support for...

  18. Radiation techniques for detection of explosives

    International Nuclear Information System (INIS)

    The detection of explosive material in airport baggage requires a device that can quickly detect a small amount of explosives with a high success rate and a low positive false alarm rate. The device should be able to handle carry-on as well as checked baggage and should provide indications that are independent of the geometric configuration of the material. The mass density of an explosive compound is relatively high. Also, explosives have high nitrogen and oxygen densities. Most detection techniques exploit the nitrogen-rich nature of explosives. Although few materials have such a high nitrogen density, some plastics, clothing materials and narcotics have also high nitrogen content. In order to distinguish such innocuous materials from explosives, one needs to detect the presence of other elements, particularly oxygen. The measurement of high oxygen density in the inspected object, together with a high nitrogen density, provides a strong indication that the object contains an explosive material. This is the minimum requirement for unambiguous determination of the presence of explosives. An additional measurement will decrease the degree of ambiguity and increase the reliability of the system. A number of radiation based techniques have been developed, or are being considered for the detection of explosives. This paper reviews some of these techniques, based on the type and mode of interaction of the radiation employed

  19. Detonation Propagation Characteristics of Superposition Explosive Materials

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In order to investigate detonation propagation characteristics of different charge patterns,the detonation velocities of superposition strip-shaped charges made up of a detonating cord and explosives were measured by a detonation velocity measuring instrument under conditions of different ignition.The experimental results and theoretical analysis show that the maximum detonation propagation velocity depends on the explosive materials with the maximum velocity among all the explosive materials.Using detonating cord in a superposition charge can shorten detonation propagation time and improve the efficiency of explosive energy.The measurement method of detonation propagation velocity and experimental results are presented and investigated.

  20. Analysis of TROI-13 Steam Explosion Experiment

    Directory of Open Access Journals (Sweden)

    Mitja Uršič

    2008-01-01

    Full Text Available The prediction of steam explosion inducing loads in nuclear power plants must be based on results of experimental research programmes and on simulations using validated fuel-coolant interaction codes. In this work, the TROI-13 steam explosion experiment was analysed with the fuel-coolant interaction MC3D computer code. The TROI-13 experiment is one of several experiments performed in the TROI research program and resulted in a spontaneous steam explosion using corium melt. First, the TROI-13 premixing simulations were performed to determine the initial conditions for the steam explosion simulations and to evaluate the melt droplets hydrodynamic fragmentation model. Next, a number of steam explosion simulations were performed, varying the steam explosion triggering position and the melt droplets mass participating in the steam explosion. The simulation results revealed that there is an important influence of the participating melt droplets mass on the calculated pressure loads, whereas the influence of the steam explosion triggering position on the steam explosion development was less expressive.