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1.
Enrichment, isolation, and characterization of 4-chlorophenol-degrading bacterium Rhizobium sp. 4-CP-20 总被引:2,自引:0,他引:2
The objectives of this research were to monitor the variations of species in mixed cultures during the enrichment period,
isolate species and identify and characterize the pure 4-chlorophenol (4-CP) degrading strains from enriched mixed cultures.
Strain Rhizobium sp. 4-CP-20 was isolated from the acclimated mixed culture. The DGGE result indicated that strain Rhizobium sp. 4-CP-20 was undetectable at the beginning but detectable after 2 weeks of enrichment. The optimum growth temperatures
for Rhizobium sp. 4-CP-20 were both 36°C using 350 mg l−1 glucose or sodium acetate as the substrate. The optimum pH range for degrading 100 mg l−1 4-CP was between 6.89 and 8.20. Strain Rhizobium sp. 4-CP-20 could degrade 4-CP completely within 3.95 days, as the initial 4-CP concentration was 100 mg l−1. If the initial 4-CP concentration was higher than 240 mg l−1, the growth of bacterial cells and the activity of degrading 4-CP were both inhibited. 相似文献
2.
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
3.
SA Ahmad NA Shamaan NM Arif GB Koon MY Shukor MA Syed 《World journal of microbiology & biotechnology》2012,28(1):347-352
A locally isolated Acinetobacter sp. Strain AQ5NOL 1 was encapsulated in gellan gum and its ability to degrade phenol was compared with the free cells. Optimal
phenol degradation was achieved at gellan gum concentration of 0.75% (w/v), bead size of 3 mm diameter (estimated surface
area of 28.26 mm2) and bead number of 300 per 100 ml medium. At phenol concentration of 100 mg l−1, both free and immobilized bacteria exhibited similar rates of phenol degradation but at higher phenol concentrations, the
immobilized bacteria exhibited a higher rate of degradation of phenol. The immobilized cells completely degrade phenol within
108, 216 and 240 h at 1,100, 1,500 and 1,900 mg l−1 phenol, respectively, whereas free cells took 240 h to completely degrade phenol at 1,100 mg l−1. However, the free cells were unable to completely degrade phenol at higher concentrations. Overall, the rates of phenol
degradation by both immobilized and free bacteria decreased gradually as the phenol concentration was increased. The immobilized
cells showed no loss in phenol degrading activity after being used repeatedly for 45 cycles of 18 h cycle. However, phenol
degrading activity of the immobilized bacteria experienced 10 and 38% losses after the 46 and 47th cycles, respectively. The
study has shown an increased efficiency of phenol degradation when the cells are encapsulated in gellan gum. 相似文献
4.
Nicolette A. Zhou April C. Lutovsky Greta L. Andaker Heidi L. Gough John F. Ferguson 《Biodegradation》2013,24(6):813-827
Pharmaceutical and personal care products (PPCPs) discharged with wastewater treatment plant (WWTP) effluents are an emerging surface water quality concern. Biological transformation has been identified as an important removal mechanism during wastewater treatment. The aim of this research was the identification of bacteria with characteristics for potential bioaugmentation to enhance PPCP removal. We report here the cultivation and characterization of bacteria capable of degrading PPCPs to ng/L concentrations. An isolation approach was developed using serial enrichment in mineral medium containing 1 mg/L of an individual PPCP as the sole organic carbon source available to heterotrophs until the original activated sludge inocula was diluted to ~10?8 of its initial concentration, followed by colony growth on solid R2A agar. Eleven bacteria were isolated, eight that could remove triclosan, bisphenol A, ibuprofen, or 17β-estradiol to below 10 ng/L, one that could remove gemfibrozil to below 60 ng/L, and two that could remove triclosan or E2, but not to ng/L concentrations. Most bacterial isolates degraded contaminants during early growth when grown utilizing rich carbon sources and were only able to degrade the PPCPs on which they were isolated. Seven of the bacterial isolates were sphingomonads, including all the triclosan and bisphenol A degraders and the ibuprofen degrader. The study results indicate that the isolated bacteria may have a positive influence on removal in WWTPs if present at sufficient concentrations and may be useful for bioaugmentation. 相似文献
5.
Aerobic bacteria degrading o-nitrobenzaldehyde (ONBA) were isolated from activated sludges. One of the isolates, ONBA-17, was identified as Pseudomonas sp. The isolate could grow on ONBA as its sole source of carbon and nitrogen. Further studies demonstrated that the strain
was a moderately halophilic bacterium and capable of degrading benzoic acid, 2-nitrophenol, 2-aminophenol, 4-hydroxybenzoic
acid, and 4-dimetylaminobenzaldehyde. It could completely degrade 100 mg L−1 ONBA at a range of pH 6–8 in 48 h at 30°C, and up to 400 mg L−1 after 288 h. The strain showed potential to be a good candidate for biotreatment of industrial wastewaters containing ONBA
due to its salt-tolerance ability, multiresistance to some heavy metals and antibiotics, and the abilities of degradation
of aromatic compounds. These findings may help in developing a process for ONBA-containing industrial wastewater treatment. 相似文献
6.
A phenanthrene (PHE) degrading bacterium strain BZ-3 was isolated from the crude oil contaminated soil in Binzhou, China. The isolate was identified as Pseudomonas sp. BZ-3 on the basis of 16S rRNA gene sequence. Various experiments were conducted to investigate the effect of pH, salinity and PHE concentration on the degradation efficiency of PHE. The degradation efficiency and degradation metabolites of PHE were detected by using GC–MS and HPLC-MS analyses. The strain BZ-3 could degrade 75% of PHE at an initial concentration of 50 mg/L under 20 g/L salinity in 7 days. PHE degradation kinetics was estimated in a first-order degradation rate model and the rate coefficient was calculated as 0.108 d−1. On the basis of the identified degradation metabolites, the strain BZ-3 could degrade PHE in the salicylate metabolic pathway. In a mixture system consisting of PHE and other PAHs including naphthalene (NA), anthracene (ANTH), and pyrene (PYR), the strain BZ-3 showed an efficiently degradation capability. Further study showed that the strain BZ-3 could also use NA, ANTH, PYR, xylene, 1-hydroxy-2-naphthoic acid, and hexane as the sole carbon and energy source, but did not grow on nitrobenzene-containing medium. 相似文献
7.
8.
Rocha LL de Aguiar Cordeiro R Cavalcante RM do Nascimento RF Martins SC Santaella ST Melo VM 《Mycopathologia》2007,164(4):183-188
This study investigated the aerobic degradation of phenol by yeast strains isolated from an oil refinery wastewater from the
Northeast of Brazil. The samples displayed low fungal diversity, as only yeast colonies were detected on Sabouraud dextrose
agar containing chloramphenicol 0.05% (w/v). Among the isolates, three yeast strains were selected to be evaluated for their
potential for degrading high phenol concentrations. These species were identified through morphological and biochemical characteristics
as Candida tropicalis, C. rugosa, and Pichia membranaefaciens. Although the strains were able to degrade the phenol concentration present in the wastewater, which was 7 mg l−1, only C. tropicalis was capable of growing at high concentrations of phenol such as 500 mg l−1 and 1,000 mg l−1 in a mineral medium containing this pollutant as the only carbon source. C. rugosa and P. membranaefaciens were inhibited in the presence of 500 mg l−1 of phenol. However, a longer incubation time was needed for C. tropicalis strain to degrade 1,000 mg l−1 of phenol compared to the time required to degrade 500 mg l−1. Moreover, the strain released a significant amount of polysaccharide biosurfactant in the medium probably to minimize the
toxic effect of the high phenol concentration. When challenged with 1,500 and 2,000 mg l−1 of phenol, C. tropicalis was unable to grow at the tested conditions. The results indicate that this strain of C. tropicalis can be considered both a good phenol-degrader and biosurfactant-producer. Application of this strain might be useful in bioremediation
activities or treatment of phenol-polluted wastewater. 相似文献
9.
Pseudomonas fluorescence KNU417 was able to degrade up to 700 mg/L of phenol in 65 h but could not degrade 1,000 mg/L of phenol. Phenol degradation
rate was noticeably enhanced by pre-adaptation. In addition, the cell was able to degrade up to 1,300 mg/L of phenol by pre-adapting
to 700 mg/L of phenol. Repeated adaptations to the same concentration of phenol showed negligible increase in degradation
rate. Also, relatively low concentration of phenol (100–700 mg/L) required only one pre-adaptation while high concentration
(1,000 mg/L) did two consecutive stepwise pre-adaptations for rapid degradation. Optimal adaptation routes were suggested
for the fast phenol degradation. For example, 1,000 mg/L of phenol was degraded as fast as in 48 h when the cell was pre-adapted
to 100 and 300 mg/L of phenol sequentially. The mechanism of adaptation was explained in terms of catechol 1,2-dioxygenase
induction, related to aromatic ring cleavage. 相似文献
10.
Daisuke Sugimori 《Applied microbiology and biotechnology》2009,82(2):351-357
To develop a microbial treatment of edible oil-contaminated wastewater, microorganisms capable of rapidly degrading edible
oil were screened. The screening study yielded a yeast coculture comprising Rhodotorula pacifica strain ST3411 and Cryptococcus laurentii strain ST3412. The coculture was able to degrade efficiently even at low contents of nitrogen ([NH4–N] = 240 mg/L) and phosphorus sources ([PO4–P] = 90 mg/L). The 24-h degradation rate of 3,000 ppm mixed oils (salad oil/lard/beef tallow, 1:1 w/w) at 20°C was 39.8% ± 9.9% (means ± standard deviations of eight replicates). The highest degradation rate was observed at
20°C and pH 8. In a scaled-up experiment, the salad oil was rapidly degraded by the coculture from 671 ± 52.0 to 143 ± 96.7 ppm
in 24 h, and the degradation rate was 79.4% ± 13.8% (means ± standard deviations of three replicates). In addition, a repetitive
degradation was observed with the cell growth by only pH adjustment without addition of the cells. 相似文献
11.
Aims: To isolate and characterize bacteria capable of degrading nicotine from the rhizospheric soil of a tobacco plant and to use them to degrade the nicotine in tobacco solid waste. Methods and Results: A bacterium, strain S33, was newly isolated from the rhizospheric soil of a tobacco plant, and identified as Agrobacterium sp. based on morphology, physiological tests, Biolog MicroLog3 4·20 system and 16S rRNA gene sequence. Using nicotine as the sole source of carbon and nitrogen in the medium, it grew optimally with 1·0 g l?1 of nicotine at 30°C and pH 7·0, and nicotine was completely degraded within 6 h. The resting cells prepared from the glucose‐ammonium medium or LB medium could not degrade nicotine within 10 h, while those prepared from the nicotine medium could completely degrade 3 g l?1 of nicotine in 1·5 h at a maximal rate of 1·23 g nicotine h?1 g?1 dry cell. Using the medium containing nicotine, glucose and ammonium simultaneously to cultivate strain S33, the resting cells could degrade 98·87% of nicotine in tobacco solid waste with the concentration as 30 mg nicotine g?1 dry weight tobacco solid waste within 7 h at a maximal rate of 0·46 g nicotine h?1 g?1 dry cell. Conclusions: This is the first report that Agrobacterium sp. has the ability to degrade nicotine. Agrobacterium sp. S33 could use nicotine as the sole source of carbon and nitrogen. The use of resting cells of the strain S33 prepared from the nicotine–glucose–ammonium medium was an effective method to degrade nicotine and detoxify tobacco solid waste. Significance and Impact of the Study: Nicotine in tobacco wastes is both toxic and harmful to human health and the environment. This study showed that Agrobacterium sp. S33 may be suitable for the disposal of tobacco wastes and reducing the nicotine content in tobacco leaves. 相似文献
12.
Jian-Dong Zhang Ai-Tao Li Hui-Lei Yu Tadayuki Imanaka Jian-He Xu 《Journal of industrial microbiology & biotechnology》2011,38(5):633-641
A cytochrome P450 monooxygenase (P450SMO) from Rhodococcus sp. can catalyze asymmetric oxygenation of sulfides to S-sulfoxides. However, P450SMO-catalyzed biotransformations require a constant supply of NAD(P)H, the expense of which constitutes
a great hindrance for this enzyme application. In this study, we investigated the asymmetric oxygenation of sulfide to S-sulfoxide using E. coli cells, which co-express both the P450SMO gene from Rhodococcus sp. and the glucose dehydrogenase (GDH) gene from Bacillus subtilis, as a catalyst. The results showed that the catalytic performance of co-expression systems was markedly improved compared
to the system lacking GDH. When using recombinant E. coli BL21 (pET28a-P450-GDH) whole cell as a biocatalyst, NADPH was efficiently regenerated when glucose was supplemented in the
reaction system. A total conversion of 100% was achieved within 12 h with 2 mM p-chlorothioanisole substrate, affording 317.3 mg/L S-sulfoxide obtained. When the initial sulfide concentration was increased to 5 mM, the substrate conversion was also increased
nearly fivefold: S-sulfoxide amounted to 2.5 mM (396.6 mg/L) and the ee value of sulfoxide product exceeded 98%. In this system, the effects of glucose concentration and substrate concentration
were further investigated for efficient biotransformation. This system is highly advantageous for the synthesis of optically
pure S-sulfoxide. 相似文献
13.
《Genomics》2022,114(2):110266
The soil bacteria isolated in this study, including three strains of actinobacteria and one Paraburkholderia sp., showed decolorization activity of azo dyes in the resting cell assay and were shown to use methyl red as the sole carbon source to proliferate. Therefore, their ability to degrade, bioabsorb, or a combination of both mechanism was investigated using the substrate brilliant black. The strains DP-A9 and DP-L11, within 24 h of incubation, showed complete biodegradation of 173.54 mg/L brilliant black and the strains DP-D10 and DP-P12 showed partial decolorization of 83.3 mg/L and 36.4 mg/L, respectively, by both biosorption and biodegradation. In addition, the shotgun assembled genome of these strains showed a highly diverse set of genes encoding for candidate dye degrading enzymes, providing avenues to study azo dye metabolism in more detail. 相似文献
14.
Three pentachlorophenol (PCP) degrading bacterial strains were isolated from sediment core of pulp and paper mill effluent
discharge site. The strains were continuously enriched in mineral salts medium supplemented with PCP as sole source of carbon
and energy. One of the acclimated strains with relatively high PCP degradation capability was selected and characterized in
this study. Based on morphology, biochemical tests, 16S rDNA sequence analysis and phylogenetic characteristics, the strains
showed greatest similarity with Acinetobacter spp. The strain was identified as Acinetobacter sp. ISTPCP-3. The physiological characteristics and optimum growth conditions of the bacterial strain were investigated.
The results of optimum growth temperature revealed that it was a mesophile. The optimum growth temperature for the strain
was 30°C. The preferential initial pH for the strain was ranging at 6.5–7.5, the optimum pH was 7. The bacterium was able
to tolerate and degrade PCP up to a concentration of 200 mg/l. Increase in PCP concentration had a negative effect on biodegradation
rate and PCP concentration above 250 mg/l was inhibitory to its growth. Acinetobacter sp. ISTPCP-3 was able to utilize PCP through an oxidative route with ortho ring-cleavage with the formation of 2,3,5,6-tetrachlorohydroquinone and 2-chloro-1,4-benzenediol, identified using gas chromatograph–mass
spectrometric (GC–MS) analysis. The degradation pathway followed by isolated bacterium is different from previously characterized
pathway. 相似文献
15.
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
16.
磷酸三(1-氯-2-丙基)酯降解菌筛选及其降解特性 总被引:1,自引:1,他引:0
【背景】磷酸三(1-氯-2-丙基)酯[tris-(1-chloro-2-propyl)phosphate,TCIPP]作为全球广泛关注的新兴有机污染物,具有环境赋存含量高、不易生物降解等特点,亟须开发TCIPP的高效去除技术。【目的】获得具有较高TCIPP降解效率并可用于TCIPP污染修复的新菌株。【方法】利用梯度提高无机盐培养基中TCIPP浓度的方法,从TCIPP污染土壤中筛选出1株能够降解液体中高浓度TCIPP (100 mg/L)的菌株,根据16S rRNA基因序列分析对其进行鉴定,并首次对其降解液体中TCIPP的特性进行研究。【结果】所筛选的TCIPP降解菌株DT-6为苍白杆菌(Ochrobactrum sp.),它能够利用TCIPP作为唯一碳源和能源;当TCIPP初始浓度为50 mg/L、培养时间为7 d时DT-6的生物量最大,对TCIPP的降解率也达到最高,为34.6%;蔗糖的加入能够显著促进DT-6的生长,但却抑制了其对TCIPP的降解。【结论】本研究报道了一株TCIPP高效降解菌Ochrobactrum sp. DT-6,能够为环境中TCIPP污染的生物修复提供新的种质... 相似文献
17.
A genetically engineered microorganism (GEM) capable of simultaneous degrading methyl parathion (MP) and carbofuran was successfully
constructed by random insertion of a methyl parathion hydrolase gene (mpd) into the chromosome of a carbofuran degrading Sphingomonas sp. CDS-1 with the mini-transposon system. The GEM constructed was relatively stable and cell viability and original degrading
characteristic was not affected compared with the original recipient CDS-1. The effects of temperature, initial pH value,
inoculum size and alternative carbon source on the biodegradation of MP and carbofuran were investigated. GEM cells could
degrade MP and carbofuran efficiently in a relatively broad range of temperatures from 20 to 30°C, initial pH values from
6.0 to 9.0, and with all initial inoculation cell densities (105–107 CFU ml−1), even if alternative glucose existed. The optimal temperature and initial pH value for GEM cells to simultaneously degrade
MP and carbofuran was at 30°C and at pH 7.0. The removal of MP and carbofuran by GEM cells in sterile and non-sterile soil
were also studied. In both soil samples, 50 mg kg−1 MP and 25 mg kg−1 carbofuran could be degraded to an undetectable level within 25 days even if there were indigenous microbial competition
and carbon sources effect. In sterile soil, the biodegradation rates of MP and carbofuran were faster, and the decline of
the inoculated GEM cells was slower compared with that in non-sterile soil. The GEM constructed in this study was potential
useful for pesticides bioremediation in natural environment. 相似文献
18.
Biodegradation of Chlorpyrifos in Soil by Enriched Cultures 总被引:3,自引:0,他引:3
Three aerobic bacterial consortia, AC, BC, and DC, developed from pesticide-contaminated soils of Punjab were able to degrade
chlorpyrifos after 21 days of incubation in basal medium by 54, 46, and 61% and chlorpyrifos (50 mg/L) in soil after 30 days
by 50, 56, and 64%. Pseudomonas aeruginosa, Bacillus cereus, Klebsiella sp., and Serratia marscecens obtained from these consortia showed 84, 84, 81, and 80% degradation of chlorpyrifos (50 mg/L) in liquid medium after 20 days
and 92, 60, 56, and 37% degradation of chlorpyrifos (50 mg/L) in soil after 30 days. Populations of Bacillus cereus, Klebsiella sp., and Serratia marscecens remained steady in soil experiments except for P. aeruginosa, where the population showed a substantial increase. Formation of 3,5,6-trichloro-2-pyridinol, the major metabolite of chlorpyrifos
degradation, was observed during the degradation of chlorpyrifos by P. aeruginosa, which disappeared to negligible amounts. 相似文献
19.
A pentachlorophenol (PCP) degrading bacterium was isolated and characterized from sludge of pulp and paper mill. This isolate
used PCP as its sole source of carbon and energy and was capable of degrading this compound, as indicated by stoichiometric
release of chloride and biomass formation. Based on morphology, biochemical tests, and 16S rRNA gene sequence analysis this
strain was identified as Kocuria sp. CL2. High Performance Liquid Chromatography (HPLC) analysis revealed that this strain was able to degrade PCP up to a
concentration of 600 mg/l. This is first time we are reporting the degradation of PCP by the Kocuria species. This isolate was also able to remove 58.64% of PCP from the sludge within two weeks. This study showed that the
removal efficiency of PCP by CL2 was found to be very effective and can be used in degradation of PCP containing pulp paper
mill waste in the environment. 相似文献
20.
S. B. Nandeshwar Sandhya Moghe P. K. Chakrabarty M. K. Deshattiwar Keshav Kranthi P. Anandkumar C. D. Mayee B. M. Khadi 《Plant Molecular Biology Reporter》2009,27(4):549-557
An Agrobacterium-mediated gene transfer protocol was developed for the diploid cotton Gossypium arboreum using meristematic cells of shoot tips, followed by direct shoot organogenesis or multiple shoot induction of putative transformants.
Seven-day- old shoot tips of in vitro-germinated seedlings of G. arboreum cv. RG8 were excised by removing cotyledonary leaves and providing “V”-shaped oblique cuts on either side of explants. Excised
explants were inoculated with an overnight-grown culture of Agrobacterium tumefaciens carrying a plant cloning vector harboring the cry1Ac gene. The explants were co-cultivated in Murashige and Skoog (MS) medium supplemented with 30 mg/L acetosyringone, 100 mg/L
myoinositol, 10 mg/L thiamine, and 30 g/L glucose for three days in the dark. Following co-cultivation, explants were incubated
on the same medium supplemented with 20 mg/L kanamycin, for first three passages of 10–12 days each and subsequently on 50 mg/L
kanamycin to facilitate stable expression of transgene. Explants were then transferred to a fresh MS medium supplemented with
either kinetin (0.1 mg/L), myoinositol (100 mg/L), thiamine (10 mg/L) and glucose (30 g/L) or benzyl adenine, BA (2 mg/L),
kinetin (1 mg/L), myoinositol (100 mg/L), thiamine (10 mg/L), and glucose (30 g/L) to induce either single or multiple putative
transformant shoots, respectively. Following 6 weeks, shoots were transferred to a rooting medium consisting of liquid MS
supplemented with 0.05–0.1 mg/L NAA and glucose (15 g/L). Rooted plantlets were first acclimatized in liquid MS with 0.05 mg/L
NAA and 15 g/L glucose, transferred to plastic pots containing soilrite Mix-TC (a mixture of Irish peat moss and horticultural
grade expanded perlite, 75:25), and grown under controlled temperature and humidity conditions in a growth chamber. Acclimatized
plants were then transferred to clay pots and grown in the greenhouse. These plants were confirmed as transgenic for cry1Ac gene using polymerase chain reaction, enzyme linked imunosorbent assay, and Southern blot analyses. 相似文献