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1.
Using laboratory and field experiments, the ability of Streptomyces aureus HP-S-01 to eliminate β-cypermethrin (β-CP) and its metabolite 3-phenoxybenzaldehyde (3-PBA) in soils was investigated. In
the laboratory, 80.5% and 73.1% of the initial dose of β-CP and 3-PBA (50 mg kg−1) was removed in sterilized soils within 10 days, respectively, while in the same period, disappearance rate of β-CP and 3-PBA
in non-sterilized soils was higher and reached 87.8% and 79.3%, respectively. Furthermore, the disappearance process followed
the first-order kinetics and the half-life (T
1/2) for β-CP and 3-PBA reduced by 20.3–52.9 and 133.7–186.8 days, respectively, as compared to the controls. The addition of
sucrose to the soils enhanced the ability of strain HP-S-01 to eliminate β-CP and 3-PBA. Similar results were observed in
the field experiments. The introduced strain HP-S-01 quickly adapted to the environment and rapidly removed β-CP and 3-PBA
without any lag phases in the field experiments. Compared with the controls, 47.9% and 67.0% of applied dose of β-CP and 3-PBA
was removed from the soils without extra carbon sources and 52.5% and 73.3% of β-CP and 3-PBA was eliminated in soils supplemented
with sucrose within 10 days, respectively. Analysis of β-CP degradation products in soil indicated that the tested strain
transform β-CP to 3-PBA and α-hydroxy-3-phenoxy-benzeneacetonitrile. However, both intermediates were transient and they disappeared
after 10 days. Therefore, the selected actinomyces strain HP-S-01 is suitable for the efficient and rapid bioremediation of
β-CP contaminated soils. 相似文献
2.
A bacterial strain ZS-S-01, newly isolated from activated sludge, could effectively degrade fenvalerate and its hydrolysis
product 3-phenoxybenzoic acid (3-PBA). Based on the morphology, physiological biochemical characteristics, and 16 S rDNA sequence,
strain ZS-S-01 was identified as Stenotrophomonas sp. Strain ZS-S-01 could also degrade and utilize deltamethrin, beta-cypermethrin, beta-cyfluthrin, and cyhalothrin as substrates
for growth. Strain ZS-S-01 was capable of degrading fenvalerate rapidly without a lag phase over a wide range of pH and temperature,
even in the presence of other carbon sources, and metabolized it to yield 3-PBA, then completely degraded it. No persistent
accumulative product was detected by HPLC and GC/MS analysis. Studies on biodegradation in various soils showed that strain
ZS-S-01 demonstrated efficient degradation of fenvalerate and 3-PBA (both 50 mg·kg−1) with a rate constant of 0.1418–0.3073 d−1, and half-lives ranged from 2.3 to 4.9 days. Compared with the controls, the half-lives for fenvalerate and 3-PBA reduced
by 16.9–156.3 days. These results highlight strain ZS-S-01 may have potential for use in bioremediation of pyrethroid-contaminated
environment. 相似文献
3.
Biodegradation of methyl parathion and p-nitrophenol by a newly isolated Agrobacterium sp. strain Yw12 总被引:1,自引:0,他引:1
Strain Yw12, isolated from activated sludge, could completely degrade and utilize methyl parathion as the sole carbon, phosphorus
and energy sources for growth in the basic salt media. It could also completely degrade and utilize p-nitrophenol as the sole carbon and energy sources for growth in the minimal salt media. Phenotypic features, physiological
and biochemical characteristics, and phylogenetic analysis of 16S rRNA sequence showed that this strain belongs to the genus
of Agrobacterium sp. Response surface methodology was used to optimize degradation conditions. Under its optimal degradation conditions, 50 mg l−1 MP was completely degraded within 2 h by strain Yw12 and the degradation product PNP was also completely degraded within
6 h. Furthermore, strain Yw12 could also degrade phoxim, methamidophos, chlorpyrifos, carbofuran, deltamethrin and atrazine
when provided as the sole carbon and energy sources. Enzymatic analysis revealed that the MP degrading enzyme of strain Yw12
is an intracellular enzyme and is expressed constitutively. These results indicated that strain Yw12 might be used as a potential
and effective organophosphate pesticides degrader for bioremediation of contaminated sites. 相似文献
4.
Peng Guo Baozhan Wang BaoJian Hang Lian Li Shinawar Waseem Ali Jian He Shunpeng Li 《International biodeterioration & biodegradation》2009,63(8):1107-1112
A pyrethroid-degrading bacterium strain JZ-2 was isolated from activated sludge treating pyrethroid-manufacturing wastewater. Based on the morphological, physiological and biochemical characterization, and phylogenetic analysis of the 16S rRNA gene sequence, the strain was identified as Sphingobium sp. Strain JZ-2 was capable of degrading fenpropathrin, cypermethrin, permethrin, cyhalothrin, deltamethrin, fenvalerate and bifenthrin. This strain degraded fenpropathrin by hydrolysis of the carboxylester linkage to yield 3-phenoxybenzaldehyde and 2,2,3,3-tetramethylcyclopropanecarboxylic acid. 3-Phenoxybenzaldehyde, 3-phenoxybenzoate, protocatechuate and catechol are the intermediates of fenpropathrin degradation. Protocatechuate and catechol were further oxidized by ortho-cleavage pathway. A novel pyrethroid hydrolase from cell-free extract was purified 108.5-fold to apparent homogeneity with a 10.2% overall recovery. It was a monomer with a molecular mass of 31 ± 1 kDa, a pI of 4.85. The optimal pH and temperature were 7.5 and 40 °C, respectively. No cofactors or coenzymes were required for the pyrethroid-hydrolysis activity. The enzyme was strongly inhibited by many irons (Ag+, Cu2+, Hg2+ and Zn2+), SDS, p-chloromercuribenzoic acid, phenylmethylsulfonyl fluoride and malathion. 相似文献
5.
Bao-zhan Wang Yun Ma Wei-you Zhou Jin-wei Zheng Jian-chun Zhu Jian He Shun-peng Li 《World journal of microbiology & biotechnology》2011,27(10):2315-2324
A synthetic pyrethroid (SP)-degrading bacterium, designated pyd-1, was isolated from SPcontaminated soil. Based on its phenotypic
and genotypic properties, the strain was identified as Ochrobactrum tritici. Strain pyd-1 was able to degrade a wide range of SPs, and its degradation efficiencies were dependent on the molecular structure
of the SP. Interestingly, the strain degraded cis- and trans-permethrin (cypermethrin) at nearly the same rate and possessed
approximately equal hydrolysis activities toward the two enantiomers of fenpropathrin. These results suggest that different
isomers of SPs are degraded with equal efficiency by strain pyd-1. We studied the metabolic pathway of fenpropathrin degradation
in strain pyd-1 by metabolite identification and enzymatic analysis. Fenpropathrin is degraded by hydrolysis of the carboxylester
linkage to yield 2,2,3,3-tetramethylcyclopropanecarboxylic acid and 3-phenoxybenzaldehyde, which is converted to 3-phenoxybenzoic
acid (PBA). PBA is further metabolized to 4-hydroxy-3-phenoxybenzoic acid (4-hydroxy-PBA). 4-Hydroxy-PBA is oxidized to protocatechuate
and p-hydroquinone. Protocatechuate is further oxidized through an ortho-cleavage pathway, and p-hydroquinone is degraded
via 1,2,4-benzenetriol. 相似文献
6.
SW Ali FB Yu LT Li XH Li LF Gu JD Jiang SP Li 《World journal of microbiology & biotechnology》2012,28(1):39-45
Burkholderia sp. GB-01 strain was used to study different factors affecting its growth for inoculum production and then evaluated for
abamectin degradation in soil for optimization under various conditions. The efficiency of abamectin degradation in soil by
strain GB-01 was seen to be dependent on soil pH, temperature, initial abamectin concentration, and inoculum size along with
inoculation frequency. Induction studies showed that abamectin depletion was faster when degrading cells were induced by pre-exposure
to abamectin. Experiments performed with varying concentrations (2–160 mg Kg−1) of abamectin-spiked soils showed that strain GB-01 could effectively degrade abamectin over the range of 2–40 mg Kg−1. The doses used were higher than the recommended dose for an agricultural application of abamectin, taking in account the
over-use or spill situations. A cell density of approximately 108 viable cells g−1 dry weight of soil was found to be suitable for bioremediation over a temperature range of 30–35°C and soil pH 7.5–8.5. This
is the first report on bacterial degradation of abamectin in soil by a Burkholderia species, and our results indicated that this bacterium may be useful for efficient removal of abamectin from contaminated
soils. 相似文献
7.
AE Abo-Amer 《World journal of microbiology & biotechnology》2012,28(3):805-814
Bacteria capable of degrading the pesticide, cadusafos, were isolated from agricultural soil using an enrichment method. In
this way, five distinct cadusafos-degrading strains of Pseudomonas putidia were isolated, and were characterized using morphological and biochemical analysis, as well as 16S rRNA sequencing. Strain
PC1 exhibited the greatest cadusafos degradation rate and was consequently selected for further investigation. Degradation
of cadusafos by strain PC1 was rapid at 20 and 37°C, but was greatly reduced (~1.5-fold) by the presence of carbon sources.
Strain PC1 was able to effectively degrade cadusafos in sterilized soil using low inoculum levels. The maximum degradation
rate of cadusafos (V
max
) was calculated as 1.1 mg l−1 day−1, and its saturation constant (K
s
) was determined as 2.5 mg l−1. Bacteria such as strain PC1, that use cadusafos as a carbon source, could be employed for the bioremediation of sites contaminated
with pesticides. 相似文献
8.
Triazophos is one of the most widely used organophosphorus insecticides usually detectable in the environment. A bacterial
strain, Diaphorobacter sp. TPD-1, capable of using triazophos and its intermediate, 1-phenyl-3-hydroxy-1,2,4-triazole (PHT), as its sole carbon
sources for growth was isolated from a triazophos-contaminated soil in China. This strain could completely degrade 50 mg l−1 triazophos and PHT to non-detectable level in 24 and 56 h, respectively. During PHT degradation, three metabolites were detected
and identified based on tandem mass spectrometry (MS/MS) analysis. Using this information, a biochemical degradation pathway
of triazophos by Diaphorobacter sp. TPD-1 was proposed. The first step involved in the degradation of triazophos is the hydrolysis of the P–O ester bond
of triazophos to form PHT and o,o-diethyl phosphorothioic acid, then the triazol ring of PHT is subsequently cleaved to form (E)-1-formyl-2-phenyldiazene.
Subsequently, (E)-1-formyl-2-phenyldiazene is transformed to 2-phenylhydrazinecarboxylic acid by adding one molecular of H2O. Finally, the carboxyl group of 2-phenylhydrazinecarboxylic acid is decarboxylated to form phenylhydrazine. 相似文献
9.
A bacterial strain able to degrade dichloromethane (DCM) as the sole carbon source was isolated from a wastewater treatment
plant receiving domestic and pharmaceutical effluent. 16S rDNA studies revealed the strain to be a Xanthobacter sp. (strain TM1). The new isolated strain when grown aerobically on DCM showed Luong type growth kinetics, with μmax of 0.094 h−1 and S
m of 1,435 mg l−1. Strain TM1 was able to degrade other aromatic and aliphatic halogenated compounds, such as halobenzoates, 2-chloroethanol
and dichloroethane. The gene for DCM dehalogenase, which is the key enzyme in DCM degradation, was amplified through PCR reactions.
Strain TM1 contains type A DCM dehalogenase (dcmAa), while no product could be obtained for type B dehalogense (dcmAb). The sequence was compared against 12 dcmAa from other DCM degrading strains and 98% or 99% similarity was observed with all other previously isolated DCM dehalogenase
genes. This is the first time a Xanthobacter sp. is reported to degrade DCM. 相似文献
10.
Saleha Husain 《World journal of microbiology & biotechnology》2008,24(11):2411-2419
The effect of surfactants on pyrene degradation in Pseudomonas fluorescens 29L was investigated. This strain produced 30.1 μM of rhamnolipid equivalents (RE) of biosurfactants on 50 mg of pyrene per
liter of medium. The production of biosurfactants was significantly correlated with the water solubility (S
w) of the substrate and the growth rate on it. When chrysene, with a S
w of 2.8 × 10−3 mg per liter of water, was the carbon source, 13.1 μM of RE of biosurfactants were produced compared to 10.3 μM of RE of
biosurfactants on acenaphthene with a S
w of 1.9 mg per liter of water. No biosurfactants were produced on salicylic acid, catechol, and citrate. All of the strain
29L mutants which grew on pyrene produced biosurfactants while among the mutants which grew on naphthalene, only 88.4% produced
biosurfactants. The rhamnolipid mixture, JBR425, inhibited the growth of Strain 29L wild type (WT) and all of its mutants
on pyrene. However, these mutants were able to grow in the presence of pyrene when the growth medium was supplemented with
10−6 mg of emulsan per milliliter of medium. This study implies biosurfactants are produced by Strain 29L as a physiological response
to the hydrophobicity of pyrene. The combined use of indigenous biosurfactants and the added biosurfactant, emulsan, is a
biotechnology to enhance pyrene degradation by Pseudomonas fluorescens 29L. 相似文献
11.
We report here the degradation of a pesticide, malathion, by Brevibacillus sp. strain KB2 and Bacillus cereus strain PU, isolated from soil samples collected from malathion contaminated field and an army firing range respectively.
Both the strains were cultured in the presence of malathion under aerobic and energy-limiting conditions. Both strains grew
well in the medium having malathion concentration up to 0.15%. Reverse phase HPLC–UV analysis indicated that Strain KB2 was
able to degrade 72.20% of malaoxon (an analogue of malathion) and 36.22% of malathion, while strain PU degraded 87.40% of
malaoxon and 49.31% of malathion, after 7 days of incubation. The metabolites mal-monocarboxylic acid and mal-dicarboxylic
acid were identified by Gas chromatography/mass spectrometry. The factors affecting biodegradation efficiency were investigated
and effect of malathion concentration on degradation rate was also determined. The strain was analyzed for carboxylesterase
activity and maximum activity 210 ± 2.5 U ml−1 and 270 U ± 2.7 ml−1 was observed for strains KB2 and PU, respectively. Cloning and sequencing of putative malathion degrading carboxylesterase
gene was done using primers based PCR approach. 相似文献
12.
研究不同接菌量、温度、pH、装液量和农药初始浓度对链霉菌HP-S-01降解高效氯氰菊酯的影响。结果表明,在接菌量为0.6 g/L、28°C、pH 7.5和装液量为50 mL/250 mL三角瓶条件下培养3 d,该链霉菌对100 mg/L高效氯氰菊酯降解率达到96%以上。链霉菌HP-S-01还能明显降解高效氟氯氰菊酯、高效氯氟氰菊酯、右旋苯醚菊酯和胺菊酯等拟除虫菊酯农药,且降解过程符合一级动力学模型,降解半衰期分别为0.78、0.88、1.08和1.24 d。采用Andrews方程对链霉菌HP-S-01降解高效氯氰菊酯的过程进行拟合,其动力学参数为qmax=1.826 3 d?1,Ks=58.951 3 mg/L,Ki=359.378 2 mg/L,该链霉菌降解高效氯氰菊酯最佳的初始浓度为145.553 5 mg/L,试验数据与该动力学方程拟合较好。 相似文献
13.
Isolation and characterization of a fungus <Emphasis Type="Italic">Aspergillus</Emphasis> sp. strain F-3 capable of degrading alkali lignin 总被引:1,自引:0,他引:1
A fungus strain F-3 was selected from fungal strains isolated from forest soil in Dalian of China. It was identified as one
Aspergillus sp. stain F-3 with its morphologic, cultural characteristics and high homology to the genus of rDNA sequence. The budges or thickened node-like structures are peculiar structures of hyphae of the strain. The fungus degraded 65% of
alkali lignin (2,000 mg l−1) after day 8 of incubation at 30°C at pH 7. The removal of colority was up to 100% at 8 days. The biodegradation of lignin
by Aspergillus sp. F-3 favored initial pH 7.0. Excess acid or alkali conditions were not propitious to lignin decomposing. Addition of ammonium
l-tartrate or glucose delayed or repressed biodegradation activities. During lignin degradation, manganese peroxidase (28.2
U l−1) and laccase (3.5 U l−1)activities were detected after day 7 of incubation. GC-MS analysis of biodegraded products showed strain F-3 could convert
alkali lignin into small molecules or other utilizable products. Strain F-3 may co-culture with white rot fungus and decompose
alkali lignin effectively. 相似文献
14.
Shungang Wan Guiying Li Taicheng An Bin Guo Lei Sun Lei Zu Ailing Ren 《Biodegradation》2010,21(6):1057-1066
In the present study, a new bacterial strain isolated from activated sludge has been identified as Lysinibacillus sphaericus based on its morphology, physiochemical properties, and the results of 16S ribosomal RNA (rRNA) gene sequence analysis. This
new bacterial strain uses ethanethiol as both carbon source and energy source. The key factors for controlling the degradation
efficiency of ethanethiol by this strain were found to be initial ethanethiol concentration, temperature, and pH value of
solutions. Under the optimized conditions, as well as 4 mg l−1 ethanethiol, 30°C, and pH = 7.0, almost 100% ethanethiol can be degraded within 96 h and sulfate as a final product was detected
in aqueous medium. The degradation reaction of ethanethiol over this newly isolated strain can be described by pseudo first-order
equation in which the maximum degradation rate constant K and the minimum half-life were respectively calculated to be 0.0308 h−1 and 22.5 h under the optimal conditions. 相似文献
15.
Intensive use of chlorpyrifos has resulted in its ubiquitous presence as a contaminant in surface streams and soils. It is thus critically essential to develop bioremediation methods to degrade and eliminate this pollutant from environments. We present here that a new fungal strain Hu-01 with high chlorpyrifos-degradation activity was isolated and identified as Cladosporium cladosporioides based on the morphology and 5.8S rDNA gene analysis. Strain Hu-01 utilized 50 mg·L−1 of chlorpyrifos as the sole carbon of source, and tolerated high concentration of chlorpyrifos up to 500 mg·L−1. The optimum degradation conditions were determined to be 26.8°C and pH 6.5 based on the response surface methodology (RSM). Under these conditions, strain Hu-01 completely metabolized the supplemented chlorpyrifos (50 mg·L−1) within 5 d. During the biodegradation process, transient accumulation of 3,5,6-trichloro-2-pyridinol (TCP) was observed. However, this intermediate product did not accumulate in the medium and disappeared quickly. No persistent accumulative metabolite was detected by gas chromatopraphy-mass spectrometry (GC-MS) analysis at the end of experiment. Furthermore, degradation kinetics of chlorpyrifos and TCP followed the first-order model. Compared to the non-inoculated controls, the half-lives (t
1/2) of chlorpyrifos and TCP significantly reduced by 688.0 and 986.9 h with the inoculum, respectively. The isolate harbors the metabolic pathway for the complete detoxification of chlorpyrifos and its hydrolysis product TCP, thus suggesting the fungus may be a promising candidate for bioremediation of chlorpyrifos-contaminated water, soil or crop. 相似文献
16.
Buprofezin is a widely used insecticide that has caused environmental pollution in many areas. However, biodegradation of
buprofezin by pure cultures has not been extensively studied, and the transformation pathway of buprofezin remains unclear.
In this paper, a buprofezin co-metabolizing strain of DFS35-4 was isolated from a buprofezin-polluted soil in China. Strain
DFS35-4 was preliminarily identified as Pseudomonas sp. based on its morphological, physiological, and biochemical properties, as well as 16S rRNA gene analysis. In the presence
of 2.0 g l−1 sodium citrate, strain DFS35-4 degraded over 70% of 50 mg l−1 buprofezin in 3 days. Strain DFS35-4 efficiently degraded buprofezin in the pH range of 5.0–10.0 and at temperatures between
20 and 30°C. Three metabolites, 2-imino-5-phenyl-3-(propan-2-yl)-1,3,5-thiadiazinan-4-one, 2-imino-5-phenyl-1,3,5-thiadiazinan-4-one,
and methyl(phenyl) carbamic acid, were identified during the degradation of buprofezin using gas chromatography–mass spectrometry
(GC–MS) and tandem mass spectrometry (MS/MS). A partial transformation pathway of buprofezin in Pseudomonas sp. DFS35-4 was proposed based on these metabolites. 相似文献
17.
Hong Lu Jiti Zhou Jing Wang Guangfei Liu Lihong Zhao 《World journal of microbiology & biotechnology》2008,24(7):1147-1152
Sphingomonas xenophaga QYY from sludge samples could effectively decolorize 1-aminoanthraquinone-2-sulfonic acid (ASA-2), one kind of anthraquinone
dye intermediate, under aerobic conditions. More than 98% of ASA-2 could be removed within 120 h at the dye concentration
from 200 mg l−1 to 1,000 mg l−1 due to oxidative degradation. The strain converted ASA-2 to 2-(2′-hydroxy-3′-amino-4′-sulfo-benzoyl)-benzoic acid, 2-(2′-amino-3′-sulfo-6′-hydroxy-benzoyl)-benzoic
acid, o-phthalic acid and 2-amino-3-hydroxy-benzenesulfonic acid, which were identified using HPLC-MS and NMR. A possible
initial decolorization pathway was proposed according to these metabolites. The decolorization of ASA-2 by cells in the basal
salt medium was induced by ASA-2, and was due to soluble cytosolic enzymes. Combined initial decolorization pathway and the
analysis of decolorization enzyme(s), the major enzyme responsible for ASA-2 decolorization was a NADH-dependent oxygenase. 相似文献
18.
Ya-Ping Xue Sai-Zhen Xu Zhi-Qiang Liu Yu-Guo Zheng Yin-Chu Shen 《Journal of industrial microbiology & biotechnology》2011,38(2):337-345
(R)-(−)-Mandelic acid (R-MA) is an important intermediate with broad uses. Recently, R-MA production using nitrilase has been gaining more and more attention due to its higher productivity and enantioselectivity.
In this work, a new bacterium WT10, which exhibited favorable nitrilase activity and excellent enantioselectivity for production
of R-MA by enantioselective biocatalytic hydrolysis of (R,S)-mandelonitrile, was isolated and identified as a strain of Alcaligenes faecalis. In order to improve its nitrilase activity for industrial application, the wild-type strain WT10 was further subjected to
mutagenesis using a combined LiCl–ultraviolet irradiation and low energy N+ ion beams implantation technique. A valuable mutant strain A. faecalis ZJUTB10 was obtained. The nitrilase specific activity of the mutant strain was greatly improved up to 350.8 U g−1, in comparison with wild-type strain WT10 of 53.09 U g−1. The reaction conditions for R-MA production by mutant strain A. faecalis ZJUTB10 were also optimized. Nitrilase activity in mutant strain showed a broad pH optimum at pH 7.7–8.5. The optimal temperature
was 35°C. The highest production rate reached 9.3 mmol h−1 g−1. The results showed that mutant strain A. faecalis ZJUTB10 was a new candidate for efficient R-MA production from (R,S)-mandelonitrile and could potentially be used in industrial production. 相似文献
19.
Hydrolytic Dechlorination of Chlorothalonil by Ochrobactrum sp. CTN-11 Isolated from a Chlorothalonil-Contaminated Soil 总被引:1,自引:0,他引:1
Bin Liang Rong Li Dong Jiang Jiquan Sun Jiguo Qiu Yanfu Zhao Shunpeng Li Jiandong Jiang 《Current microbiology》2010,61(3):226-233
A bacterial strain, designated as CTN-11, capable of degrading chlorothalonil (CTN), was isolated from a chlorothalonil-contaminated
soil in China. Based on the morphological, biochemical characteristics and comparative analysis of the 16S rRNA genes, strain
CTN-11 was identified as Ochrobactrum sp. Strain CTN-11 could degrade 50 mg l−1 CTN to a non-detectable level within 48 h, and efficiently degrade CTN in a relatively broad range of temperatures from 20
to 40°C and initial pH values from 6.0 to 9.0. The new isolate differed from those previously reported CTN co-metabolic degraders
by transforming CTN in the absence of other carbon sources. A glutathione S-transferase (GST) coding gene, which showed 88%
sequence similarity with that from Ochrobactrum anthropi SH35B, was cloned from strain CTN-11. However, the gene was not functionally expressed in the presence of glutathione, indicating
that CTN was not reductively dechlorinated by thiolytic substitution catalyzed by GST in strain CTN-11. The metabolite hydroxyl-trichloroisophthalonitrile
(CTN-OH) produced during CTN anaerobic degradation was identified based on tandem MS/MS, confirming that hydrolytic dechlorination
was involved in the CTN degradation. The removal of CTN by strain CTN-11 in sterile and non-sterile soils was also studied.
In both soil samples, 50 mg kg−1 CTN could be degraded to an undetectable level within 3 days. This study highlights an important potential use of strain
CTN-11 for the cleanup of CTN-contaminated sites and presents a hydrolytic dechlorination reaction of CTN by a pure culture. 相似文献
20.
Takashi Kamijo Akihiro Saito Sadaharu Ema Inchi Yoh Hiroko Hayashi Ryo Nagata Yoshiho Nagata Akikazu Ando 《Antonie van Leeuwenhoek》2011,99(2):179-187
An edible-oil degrading bacterial strain HH-01 was isolated from oil plant gummy matter and was classified as a member of
the genus Bacillus on the basis of the nucleotide sequence of the 16S rRNA gene. A putative lipase gene and its flanking regions were cloned
from the strain based on its similarity to lipase genes from other Bacillus spp. The deduced product was composed of 214 amino acids and the putative mature protein, consisting of 182 amino acids,
exhibited 82% amino acid sequence identity with the subfamily I.4 lipase LipA of Bacillus subtilis 168. The recombinant product was successfully overproduced as a soluble form in Escherichia coli and showed lipase activity. The gene was, therefore, designated as lipA of HH-01. HH-01 LipA was stable at pH 4–11 and up to 30°C, and its optimum pH and temperature were 8–9 and 30°C, respectively.
The enzyme showed preferential hydrolysis of the 1(3)-position ester bond in trilinolein. The activity was, interestingly,
enhanced by supplementing with 1 mM CoCl2, in contrast to other Bacillus lipases. The lipA gene seemed to be constitutively transcribed during the exponential growth phase, regardless of the presence of edible oil. 相似文献