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1.
Shinawar Waseem Ali Rong Li Wei-you Zhou Ji-quan Sun Peng Guo Ji-ping Ma Shun-peng Li 《Biodegradation》2010,21(3):441-452
Abamectin is widely used in agriculture as an insecticide and in veterinary as an anti-parasitic agent, and has caused great
environmental pollution by posing potential risk to non-target soil invertebrates and nearby aquatic systems. A bacterium
designated GB-01, which was capable of degrading abamectin, was isolated from soil by enrichment culture method. On the basis
of morphological, physiological and biochemical characteristics, combined with phylogenetic analysis of 16S rRNA gene, the
bacterium GB-01 was identified as Burkholderia cepacia-like species. The bacterium GB-01 was able to utilize abamectin as its sole carbon source for growth, and could degrade more
than 90% of abamectin at initial concentrations of 50 and 100 mg l−1 in mineral salt medium in 30 and 36 h, respectively. The longer degradation cycle was observed with abamectin concentrations
higher than 100 mg l−1. Optimal growth temperatures and pH values with highest degradation rate were 30–35°C and 7–8, respectively. Two new degradation
products were identified and characterized by high performance liquid chromatography-tandem mass spectrometry (HPLC–MS/MS)
based mass spectral data and a plausible partial degradation pathway of abamectin was proposed. This is the first report in
which an abamectin-degrading Burkholderia species isolated from soil was identified and characterized. 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.
《International biodeterioration & biodegradation》2007,59(1):55-61
Fenitrothion, a toxic organophosphorus pesticide, can build up the concentration of nitrophenolic compound in soils and hence needs to be removed. Burkholderia sp. FDS-1, a fenitrothion-degrading strain, was used in this work to study factors affecting its growth, and then evaluated for its capacity to degrade fenitrothion in soil microcosms. Minimal salt medium containing 1% (w/v) glucose was found to be a suitable carbon source for inoculum preparation. Various factors, including soil pH, temperature, initial fenitrothion concentration, and inoculum size influenced the degradation of fenitrothion. Microcosm studies performed with varying concentrations (1–200 mg kg−1) of fenitrothion-spiked soils showed that strain FDS-1 could effectively degrade fenitrothion in the range of 1–50 mg kg−1 soil. The addition of Burkholderia sp. FDS-1 at 2×106 colony forming units g−1 soil was found to be suitable for fenitrothion degradation over a temperature range of 20–40 °C and at a slight alkaline pH (7.5). The results indicate that strain FDS-1 has potential for use in bioremediation of fenitrothion and its metabolite-contaminated sites. This is a model study that could be used for decontamination of sites contaminated with other compounds. 相似文献
4.
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
5.
A phenanthrene-degrading Mycobacterium sp. strain 6PY1 was grown in an aqueous/organic biphasic culture system with phenanthrene as sole carbon source. Its capacity
of degradation was studied during sequential inoculum enrichments, reaching complete phenanthrene degradation at a maximim
rate of 7 mg l−1 h−1. Water–oil emulsions and biofilm formation were observed in biphasic cultures after four successive enrichments. The factors
influencing interfacial area in the emulsions were: the initial phenanthrene concentration, the initial inoculum size, and
the silicone oil volume fraction. The results showed that the interfacial area was mainly dependent on the silicone oil/mineral
salts medium ratio and the inoculum size. 相似文献
6.
Experiments were conducted both under in vitro and in situ conditions to determine the biodegradation potential of button
mushroom spent substrate (SMS) and its dominating microbes (fungi and bacteria) for carbendazim and mancozeb, the commonly
used agricultural fungicides. During 6 days of incubation at 30 ± 2°C under broth culture conditions, highest degradation
of carbendazim (17.45%) was recorded with B-1 bacterial isolate, while highest degradation of mancozeb (18.05%) was recorded
with Trichoderma sp. In fungicide pre-mixed sterilized SMS, highest degradation of carbendazim (100.00–66.50 μg g−1) was recorded with mixed inoculum of Trichoderma sp. and Aspergillus sp., whereas highest degradation of mancozeb (100.00–50.50 μg g−1) was with mixed inoculum of Trichoderma sp., Aspergillus sp. and B–I bacterial isolate in 15 days of incubation at 30 ± 2°C. All these microbes both individually as well as in different
combinations grew well and produced extracellular lignolytic enzymes on SMS, which helped in fungicides degradation. Under
in situ conditions, among three different proportions of SMS (10, 20 and 30%, w/w) mixed with fungicide pre-mixed soil (100 μg g−1 of soil), the degradation of carbendazim was highest in 30% SMS treatment, while for mancozeb it was in 20% SMS treatment.
The residue levels of both fungicides decreased to half of their initial concentration after 1 month of SMS mixing. 相似文献
7.
Yong Hua He Dong Sheng Shen Cheng Ran Fang Yin Mei Zhu 《World journal of microbiology & biotechnology》2006,22(10):1095-1104
Summary Four strains of bacteria, 9 strains of fungi and 20 strains of actinomycetes capable of utilizing metsulfuron-methyl as sole carbon and energy source were isolated from a metsulfuron-methyl-treated soil by the enrichment culture method. A fungus named DS11F was selected as the most highly effective one according to the maximum tolerance concentration of 1,200 mg l−1 and metsulfuron-methyl-degrading rate of 0.0716 g g−1 cells h−1, and was identified as an unknown strain of Penicillium sp. on the basis of colony growth, morphology and biochemical characteristics.␣Through liquid pure culture, the optimal metsulfuron-methyl-degrading conditions of DS11F were determined to be metsulfuron-methyl concentration 22.6 mg l−1, inoculum concentration 12.25 mg l−1, pH 7.0 and temperature 30°C. As additional C sources, supernatant of soaked compost could increase metsulfuron-methyl degradation by 8%, but glucose was ineffective. DS11F inoculation was found to significantly enhance the degradation of metsulfuron-methyl in soil, with the reduction of the concentration reaching 50% in 6 days. Admixture of compost could promote metsulfuron-methyl degradation to some extent. The growth of the inocula in the soils remained dominant and degradation resumed immediately when metsulfuron-methyl was applied again. The results show that addition of the isolated Penicillium sp. enhances the degradation of metsulfuron-methyl in water and soil. 相似文献
8.
Shannon KE Saleh-Lakha S Burton DL Zebarth BJ Goyer C Trevors JT 《Antonie van Leeuwenhoek》2011,100(2):183-195
The effect of glucose addition (0 and 500 μg C g−1 soil) and nitrate (NO3) addition (0, 10, 50 and 500 μg NO3–N g−1 soil) on nitric oxide reductase (cnorB) gene abundance and mRNA levels, and cumulative denitrification were quantified over 48 h in anoxic soils inoculated with
Pseudomonas mandelii. Addition of glucose-C significantly increased cnorB
p
(P. mandelii and related species) mRNA levels and abundance compared with soil with no glucose added, averaged over time and NO3 addition treatments. Without glucose addition, cnorB
p
mRNA levels were higher when 500 μg NO3–N g−1 soil was added compared with other NO3 additions. In treatments with glucose added, addition of 50 μg NO3–N g−1 soil resulted in higher cnorB
p
mRNA levels than soil without NO3 but was not different from the 10 and 500 μg NO3–N g−1 treatments. cnorB
p
abundance in soils without glucose addition was significantly higher in soils with 500 μg NO3–N g−1 soil compared to lower N-treated soils. Conversely, addition of 500 μg NO3–N g−1 soil resulted in lower cnorB
p
abundance compared with soil without N-addition. Over 48 h, cumulative denitrification in soils with 500 μg glucose-C g−1 soil, and 50 or 500 μg NO3–N g−1 was higher than all other treatments. There was a positive correlation between cnorB
p
abundance and cumulative denitrification, but only in soils without glucose addition. Glucose-treated soils generally had
higher cnorB
p
abundance and mRNA levels than soils without glucose added, however response of cnorB
p
abundance and mRNA levels to NO3 supply depended on carbon availability. 相似文献
9.
Fernández-López CL Torrestiana-Sánchez B Salgado-Cervantes MA García PG Aguilar-Uscanga MG 《Bioprocess and biosystems engineering》2012,35(4):605-614
Molasses “B” is a rich co-product of the sugarcane process. It is obtained from the second step of crystallization and is
richer in fermentable sugars (50–65%) than the final molasses, with a lower non-sugar solid content (18–33%); this co-product
also contains good vitamin and mineral levels. The use of molasses “B” for ethanol production could be a good option for the
sugarcane industry when cane sugar prices diminish in the market. In a complex medium like molasses, osmotolerance is a desirable
characteristic for ethanol producing strains. The aim of this work was to evaluate the use of molasses “B” for ethanol production
using Saccharomyces cerevisiae ITV-01 (a wild-type yeast isolated from sugarcane molasses) using different initial sugar concentrations (70–291 g L−1), two inoculum sizes and the addition of nutrients such as yeast extract, urea, and ammonium sulphate to the culture medium.
The results obtained showed that the strain was able to grow at 291 g L−1 total sugars in molasses “B” medium; the addition of nutrients to the culture medium did not produce a statistically significant
difference. This yeast exhibits high osmotolerance in this medium, producing high ethanol yields (0.41 g g−1). The best conditions for ethanol production were 220 g L−1 initial total sugars in molasses “B” medium, pH 5.5, using an inoculum size of 6 × 106 cell mL−1; ethanol production was 85 g L−1, productivity 3.8 g L−1 h−1 with 90% preserved cell viability. 相似文献
10.
Banana plantlets (Musa acuminata cv Grande Naine) cultivated in hydroponics take up silicon proportionally to the concentration of Si in the nutrient solution
(0–1.66 mM Si). Here we study the Si status of banana plantlets grown under controlled greenhouse conditions on five soils
developed from andesitic volcanic ash, but differing in weathering stage. The mineralogical composition of soils was inferred
from X-ray diffraction, elemental analysis and selective chemical/mineralogical extractions. With increasing weathering, the
content of weatherable primary minerals decreased. Conversely, clay content increased and stable secondary minerals were increasingly
dominant: gibbsite, Fe oxides, allophane, halloysite and kaolinite. The contents of biogenic Si in plant and soil were governed
by the reserve of weatherable primary minerals. The largest concentrations of biogenic Si in plant (6.9–7 g kg−1) and soil (50–58 g kg−1) occurred in the least weathered soils, where total Si content was above 225 g kg−1. The lowest contents of biogenic Si in plant (2.8–4.3 g kg−1) and soil (8–31 g kg−1) occurred in the most weathered desilicated soils enriched with secondary oxides and clay minerals. Our data imply that soil
weathering stage directly impacted the soil-to-plant transfer of silicon, and thereby the stock of biogenic Si in a soil–plant
system involving a Si-accumulating plant. They further imply that soil type can influence the silicon soil–plant cycle and
its hydrological output. 相似文献
11.
Elzbieta Krolak Jerzy Kwapulinski Agnieszka Fischer 《Radiation and environmental biophysics》2010,49(2):229-237
The vertical 137Cs profile of forest and wasteland soils was analyzed in the south of the Podlasie Lowland area (Eastern Poland) about 20 years
after the Chernobyl accident. In addition, the concentration of 40K in soils of the investigated area was measured. Below the litter layer (mean thickness 3 cm), the soil samples were collected
up to a depth of 12 cm and then divided into three layers: 0–3, 3–7, 7–12 cm. The behavior of 137Cs and 40K isotopes in soils was analyzed depending on the depth from which the soil samples were collected, as well as on the content
of organic carbon, pH of soil and its granulometric composition. It was established that the density of 137Cs in the litter layer equals 2.17 kBq m−2; it is the highest in layer 0–3 cm where it equals 3.44 kBq m−2, and it decreases with the depth to the value of 0.76 kBq m−2 in layer 7–12 cm. No similar pattern was observed in wasteland soils. The concentrations of 40K in forest and wasteland soils did not change significantly with depth. 相似文献
12.
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
13.
P. Olguín-Lora S. Le Borgne G. Castorena-Cortés T. Roldán-Carrillo I. Zapata-Peñasco J. Reyes-Avila S. Alcántara-Pérez 《Biodegradation》2011,22(1):83-93
Haloalkaliphilic sulfur-oxidizing mixed cultures for the treatment of alkaline–saline effluents containing sulfide were characterized
and evaluated. The mixed cultures (IMP-PB, IMP-XO and IMP-TL) were obtained from Mexican alkaline soils collected in Puebla
(PB), Xochimilco (XO) and Tlahuac (TL), respectively. The Ribosomal Intergenic Spacer Analysis (RISA) revealed bacteria related
to Thioalkalibacterium and Thioalkalivibrio in IMP-XO and IMP-PB mixed cultures. Halomonas strains were detected in IMP-XO and IMP-TL. In addition, an uncultured Bacteroides bacterium was present in IMP-TL. Mixed cultures were evaluated at different pH and NaCl concentrations at 30°C. IMP-PB and
IMP-TL expressed thiosulfate-oxidizing activity in the 7.5–10.5 pH range, whereas IMP-XO presented its maximal activity with
19.0 mg O2 gprotein−1 min−1, at pH 10.6; it was not affected by NaCl concentrations up to 1.7 M. In continuous culture, IMP-XO showed a growth rate of
15 day−1, productivity of 433.4 mgprotein l−1 day−1 and haloalkaliphilic sulfur-oxidizing activity was also detected up to 170 mM by means of N-methyl-diethanolamine (MDEA). Saline–alkaline soil samples are potential sources of haloalkaliphilic sulfur-oxidizing bacteria
and the mixed cultures could be applied in the treatment of inorganic sulfur compounds in petroleum industry effluents under
alkaline–saline conditions. 相似文献
14.
A short rod shaped, gram-negative bacterium strain Burkholderia sp. FDS-1 was isolated from the sludge of the wastewater treating system of an organophosphorus pesticides manufacturer.
The isolate was capable of using fenitrothion as the sole carbon source for its growth. FDS-1 first hydrolyzed fenitrothion
to 3-methyl-4-nitrophenol, which was further metabolized to nitrite and methylhydroquinone. The addition of other carbon source
and omitting phosphorus source had little effect on the hydrolysis of fenitrothion. The gene encoding the organophosphorus
hydrolytic enzyme was cloned and sequenced. The sequence was similar to mpd, a gene previously shown to encode a parathion-methyl-hydrolyzing enzyme in Plesiomonas sp. M6. The inoculation of strain FDS-1 (106 cells g−1) to soil treated with 100 mg fenitrothion emulsion kg−1 resulted in a higher degradation rate than in noninoculated soils regardless of the soil sterilized or nonsterilized. These
results highlight the potential of this bacterium to be used in the cleanup of contaminated pesticide waste in the environment.
Zhonghui Zhang, Qing Hong: Both authors contributed equally to this work 相似文献
15.
Bioremediation of polychlorinated biphenyl-contaminated soil using carvone and surfactant-grown bacteria 总被引:4,自引:0,他引:4
Singer AC Gilbert ES Luepromchai E Crowley DE 《Applied microbiology and biotechnology》2000,54(6):838-843
Partial bioremediation of polychlorinated biphenyl (PCB)-contaminated soil was achieved by repeated applications of PCB-degrading
bacteria and a surfactant applied 34 times over an 18-week period. Two bacterial species, Arthrobacter sp. strain B1B and Ralstonia eutrophus H850, were induced for PCB degradation by carvone and salicylic acid, respectively, and were complementary for the removal
of different PCB congeners. A variety of application strategies was examined utilizing a surfactant, sorbitan trioleate, which
served both as a carbon substrate for the inoculum and as a detergent for the mobilization of PCBs. In soil containing 100 μg
Aroclor 1242 g−1 soil, bioaugmentation resulted in 55–59% PCB removal after 34 applications. However, most PCB removal occurred within the
first 9 weeks. In contrast, repeated addition of surfactant and carvone to non-inoculated soil resulted in 30–36% PCB removal
by the indigenous soil bacteria. The results suggest that bioaugmentation with surfactant-grown, carvone-induced, PCB-degrading
bacteria may provide an effective treatment for partial decontamination of PCB-contaminated soils.
Received: 9 March 2000 / Received revision: 27 June 2000 / Accepted: 16 July 2000 相似文献
16.
This study was designed to identify rhizobial strains specific to greengram expressing higher tolerance against insecticides,
fipronil and pyriproxyfen, and synthesizing plant growth regulators even amid insecticide-stress. Of the 50 bradyrhizobial
isolates, the Bradyrhizobium sp. strain MRM6 showed tolerance up to 1,600 μg mL−1 against each of fipronil and pyriproxyfen. The tolerant Bradyrhizobium sp. (vigna) produced plant growth promoting substances in substantial amounts, both in the presence and absence of insecticides. The
strain MRM6 was further used to investigate its impact on greengram grown in soils treated with 200 (the recommended dose),
400 and 600 μg kg−1 soil of fipronil and 1,300 (the recommended dose), 2,600 and 3,900 μg kg−1 soil of pyriproxyfen. Fipronil at 600 μg kg−1 soils and pyriproxyfen at 3,900 μg kg−1 soils had greatest toxic effects and decreased plant biomass, symbiotic efficiency, nutrient uptake and seed yield of greengram
plants. The Bradyrhizobium sp. (vigna) inoculant when used with fipronil and pyriproxyfen significantly increased the measured parameters compared to the plants
grown in soils treated solely with the same concentration of each insecticide. This study inferred that the Bradyrhizobium sp. (vigna) strain MRM6 may be exploited as bio-inoculant to increase the productivity of greengram exposed to insecticide-stressed
soils. 相似文献
17.
Bioremediation of atrazine-contaminated soil by repeated applications of atrazine-degrading bacteria 总被引:5,自引:0,他引:5
Bioaugmentation has previously been unreliable for the in situ clean-up of contaminated soils because of problems with poor
survival and the rapid decline in activity of the bacterial inoculum. In an attempt to solve these problems, a 500-l batch
fermenter was investigated for its ability to deliver inoculum repeatedly to contaminated soils via irrigation lines. In a
field experiment, mesocosms were filled with 350 kg soil containing 100 mg kg−1 atrazine, and inoculated one, four or eight times with an atrazine-degrading bacterial consortium that was produced in the
fermenter. After 12 weeks, no significant degradation of atrazine had occurred in soil that was inoculated only once; whereas,
mesocosms inoculated four and eight times mineralized 38% and 72% of the atrazine respectively. Similar results were obtained
in a laboratory experiment using soil contaminated with 100 mg kg−1 [14C]atrazine. After 35 days, soil that was inoculated once with 108 cfu ml−1 of the consortium or with the atrazine-degrading bacterium, Pseudomonas sp. strain ADP, mineralized 17% and 35% of the atrazine respectively. In comparison, microcosms inoculated every 3 days with
the consortium or with Pseudomonas sp. (ADP) mineralized 64% or 90% of the atrazine over this same period. Results of these experiments suggest that repeated
inoculation from an automated fermenter may provide a strategy for bioaugmentation of contaminated soil with xenobiotic-degrading
bacteria.
Received: 20 November 1998 / Received revision: 8 February 1999 / Accepted: 12 February 1999 相似文献
18.
Barua S Tripathi S Chakraborty A Ghosh S Chakrabarti K 《Indian journal of microbiology》2011,51(3):369-376
The effect of fluctuations of salinity in three different seasons on diazotrophic populations and N2 fixation in six mono cropped rice field soils of the coastal region of the Gangetic delta of West Bengal, India, was studied.
The average pH, ECe, organic carbon and total nitrogen of the soils ranged from 4.99–7.08, 2.02–19.58 dSm−1, 4.68–12.03 g kg−1 and 0.44–1.70 g kg −1, respectively. The average log colony forming units of the bacterial populations and N2-fixation in the soils varied from 4.61 to 5.86 and 2.74 to 4.52 mg N2 fixed 50 ml −1 culture media respectively, with the lowest value recorded in summer. Recovery of microorganisms and N2- fixation gradually decreased with extraneous addition of NaCl in the culture media. All the eight isolates were Gram positive,
spore and capsule formers. They could utilize glucose, sucrose, mannitol, starch, citrate and nitrate, and were catalase and
gelatinase positive, but indole, methyl red and Vogues Proskauer reaction negative. The organisms produced alkaline reaction
on TSI agar slant. The acetylene reduction assay of the isolates at 0 and 1% NaCl in the culture media were 4.51–164.52 and
1.72–100.6 nmole C2H4 ml−1 culture media in 72 h, respectively. The isolates could fix 2.42–4.45 and 2.04–4.08 mg N2 fixed 50 ml−1 culture media at 0 and 1% NaCl in the culture media respectively. 16S rDNA sequences of the isolates were similar to the
species: Bacillus sp. isolate 28A, Bacillus sp. MOLA 87, Bacillus sp. By113 (B)Ydz-dh, Bacillus sp. PN13, Bacillus licheniformis strain RH101, Bacterium Antarctica 14, Bacillus sp. PN13 and Bacillus megaterium. 相似文献
19.
A Bacillus sp., capable of degrading chloroform, was immobilized in calcium alginate. The beads in 20 g alginate l−1 (about 2 × 108 cells/bead) could be re-used nine times for degradation of chloroform at 40 μM. The immobilized cells had a higher range
of tolerance (pH 6.5–9 and 20–41°C) than free cells (pH 7–8.5 and 28–32°C). At 5 g alginate l−1, leakage of the cells from the beads was 0.51 mg dry wt ml−1. This species is the first reported Bacillus that can degrade chloroform as the sole carbon source. 相似文献
20.
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