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1.
Kinetics of styrene biodegradation by <Emphasis Type="Italic">Pseudomonas</Emphasis> sp. E-93486 总被引:1,自引:0,他引:1
The research into kinetics of styrene biodegradation by bacterial strain Pseudomonas sp. E-93486 coming from VTT Culture Collection (Finland) was presented in this work. Microbial growth tests in the presence
of styrene as the sole carbon and energy source were performed both in batch and continuous cultures. Batch experiments were
conducted for initial concentration of styrene in the liquid phase changed in the range of 5–90 g m−3. The Haldane model was found to be the best to fit the kinetic data, and the estimated constants of the equation were: μ
m = 0.1188 h−1, K
S = 5.984 mg l−1, and K
i = 156.6 mg l−1. The yield coefficient mean value
Y\textxs\textapp Y_{\text{xs}}^{\text{app}} for the batch culture was 0.72 gdry cells weight (gsubstrate)−1. The experiments conducted in a chemostat at various dilution rates (D = 0.035–0.1 h−1) made it possible to determine the value of the coefficient for maintenance metabolism m
d = 0.0165 h−1 and the maximum yield coefficient value
Y\textxs\textM = 0.913 Y_{\text{xs}}^{\text{M}} = 0.913 . Chemostat experiments confirmed the high value of yield coefficient
Y\textxs\textapp Y_{\text{xs}}^{\text{app}} observed in the batch culture. The conducted experiments showed high activity of the examined strain in the styrene biodegradation
process and a relatively low sensitivity to inhibition of its growth at higher concentrations of styrene in the solution.
Such exceptional features of Pseudomonas sp. E-93486 make this bacterial strain the perfect candidate for technical applications. 相似文献
2.
Eunsol Ahn Ki Young Choi Beom Sik Kang Gerben J. Zylstra Dockyu Kim Eungbin Kim 《Annals of microbiology》2017,67(6):417-424
Pseudomonas sp. strain MC1 was characterized as a cold-adapted, naphthalene-degrading bacterium that is able to grow in a broad temperature range of 5–30°C. MC1 harbors a catabolic plasmid, designated pYIC1, which is almost identical to the archetypal NAH7 plasmid from the mesophilic bacterium Pseudomonas putida G7. On pYIC1, the catabolic genes for naphthalene degradation are clustered in two operons: nahAa-Ab-Ac-Ad-B-F-C-Q-E-D encoding the conversion of naphthalene to salicylate, and nahG-T-H-I-N-L-O-M-K-J encoding the conversion of salicylate through meta-cleavage pathway to pyruvate and acetyl CoA. NahH, the bona fide extradiol dioxygenase in MC1 salicylate metabolism, is thermolabile and is a cold-adapted enzyme. The thermal profiles of the NahH enzyme activities expressed in different hosts indicate the presence of a factor(s) or mechanism(s) to protect the thermolabile NahH enzyme (100% aa identity with MC1 counterpart) in G7. Overall, the results reported in the present work suggest that the thermolabile NahH might be a product of the cold-adaptation process of MC1 and thus contribute to the survival and growth ability of MC1 on salicylate and naphthalene in cold environments. 相似文献
3.
Shashank Kumar Mishra Mohammad Haneef Khan Sankalp Misra Vijay Kant Dixit Praveen Khare Suchi Srivastava Puneet Singh Chauhan 《Antonie van Leeuwenhoek》2017,110(2):253-270
Soil bacteria may have properties of plant growth promotion but not be sufficiently beneficial for plants under stress conditions. This challenge has led researchers to extend their searches into extreme environments for potential soil bacteria with multiple plant beneficial traits as well as abiotic stress tolerance abilities. In the current study, an attempt was made to evaluate soil bacteria from an extreme environment, volcano soils, based on plant growth promoting and abiotic stress mitigating characteristics. The screening led to the isolation of eight (NBRISH4, NBRISH6, NBRISH10, NBRISH11, NBRISH13, NBRISH14, NBRISH16 and NBRISH26) bacterial isolates capable of withstanding stresses, namely temperature (up to 45 °C), salt (up to 2 M NaCl) and drought (up to 60% Poly Ethylene Glycol 6000) in vitro. Further, the selected isolates were notable for their in vitro temporal performance with regards to survival (in terms of colony count), phosphate solubilisation, biofilm formation, auxin, alginate and exo-polysaccharide production abilities under abiotic stresses i.e. 40 °C temperature; 500 mM NaCl salt and drought (PEG) conditions. In vivo seed treatments of individual selected bacteria to maize plants resulted into significant enhancement in root and shoot length, root and shoot fresh and dry weight and number of leaves per plant. Overall, the plant growth promoting and abiotic stress tolerance ability was most evident for bacterial isolate NBRISH6 which was identified as an Ochrobactrum sp. using 16S rRNA based phylogenetic analysis. 相似文献
4.
Notocactus scopa cv. Soonjung was subjected to in planta Agrobacterium tumefaciens-mediated transformation with vacuum infiltration, pin-pricking, and a combination of the two methods. The pin-pricking combined with vacuum infiltration (20-30 cmHg for 15 min) resulted in a transformation efficiency of 67-100%, and the expression of the uidA and nptII genes was detected in transformed cactus. The established in planta transformation technique generated a transgenic cactus with higher transformation efficiency, shortened selection process, and stable gene expression via asexual reproduction. All of the results showed that the in planta transformation method utilized in the current study provided an efficient and time-saving procedure for the delivery of genes into the cactus genome, and that this technique can be applied to other asexually reproducing succulent plant species. 相似文献
5.
Objectives
To improve the quality of diesel fuel via removal of aromatic compounds using Pseudomonas sp.Results
In the present study Pseudomonas sp. was able to remove 94% of fluorene, 59% of phenanthrene, 49% of anthracene, 52% of fluoranthene, 45% of pyrene and 75% carbazole present in diesel oil. Additionally, it also does not affect the aliphatic content of fuel thus maintaining the carbon backbone of the fuel.Conclusions
Pseudomonas sp. is a potential biocatalyst that can be used in the refining industry.6.
7.
Huan-Mei Li Lian-Tai Yan Cai-Fang Sun Jin-Jin Yuan-Gao Qing Hong Li Shun-Peng 《World journal of microbiology & biotechnology》2011,27(6):1323-1329
A bacterial strain K9 capable of degrading malachite green was isolated from the sludge of the wastewater treatment system
of a chemical plant. It was identified preliminarily as Pseudomonas sp. Strain K9 was also able to degrade other triphenylmethane dyes, such as Crystal Violet and Basic Fuchsin. The gene tmr2, encoding the triphenylmethane reductase, was cloned from strain K9, and functionally expressed in E. coli. A 5946-bp DNA fragment including the tmr2 gene was cloned from the genomic DNA of strain K9 by chromosome walking. Its sequence analysis showed that tmr2 was associated with a typical mobile element ISPpu12 consisting of tnpA (encoding a transposase), lspA (encoding a lipoprotein signal peptidase) and orf1 (encoding a putative MerR family regulator), orf2 (encoding a CDF family heavy metal/H+ antiporter). This association was also found in another malachite green-degrading strain Pseudomonas sp. MDB-1, which indicated that the tmr2 gene might be a horizontally transferable gene. 相似文献
8.
Kotaro Matsumoto Philippe Parola Jean-Marc Rolain Kathryn Jeffery Didier Raoult 《BMC microbiology》2007,7(1):74
Background
To date, 6 tick-borne rickettsiae pathogenic for humans are known to occur in Africa and 4 of them were first identified in ticks before being recognized as human pathogens. 相似文献9.
A genetic transformation system has been developed for callus cells of Crataegus
aronia using Agrobacterium
tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with
5 mg l−1 Indole-3-butyric acid (IBA) and 0.5 mg l−1 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different
types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red
colored callus was obtained on MS medium supplemented with 2 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l−1 kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli
were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l−1 hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this
is the first time to report an Agrobacterium-mediated transformation system in Crataegus
aronia. 相似文献
10.
Locally isolated strains of a thermoalkalotolerant Streptomyces sp. and Aspergillus
fumigatus were used for the in vitro biosynthesis of silver nanoparticles from AgNO3 solutions. An autolysed cell-free culture filtrate from each strain was used, indicating that the formation mechanism depends
on intra-cellular components for both organisms, since culture broths had no significant nanoparticle formation potential.
Nanoparticle formation was indicated by a change of the solution from colourless or light brown to dark brown after 24 h or
more, and UV–visible spectroscopy and x-ray diffraction analysis confirmed the formation by both organisms. The initial formation
kinetics were faster with Aspergillus, but formation continued for a longer period with Streptomyces, resulting in higher concentrations after 48 h. Transmission electron microscope images revealed well dispersed nanoparticles
with diameters ranging from 15 to 45 nm from A. fumigatus, while those from Streptomyces sp. had a narrower size distribution of 15–25 nm. The higher productivity and preferred narrower size distribution of Streptomyces, together with its well established industrial use, may make it the preferred choice for further optimization studies. 相似文献
11.
Koushik Mukherjee Prosun Tribedi Arup Chowdhury Tanusree Ray Archi Joardar Subhajit Giri Alok Kumar Sil 《Biodegradation》2011,22(2):377-388
Polyurethane diol (PUR-diol), a synthetic polymer, is widely used as a modifier for water-soluble resins and emulsions in
wood appliances and auto coatings. Non-biodegradability of polyurethanes (PUR) and PUR-based materials poses a threat to environment
that has led scientists to isolate microbes capable of degrading PUR. However, the bio-degradation of PUR-diol has not yet
been reported. In this study, we report isolation of a soil bacterium that can survive using PUR-diol as sole carbon source.
PUR-diol degradation by the organism was confirmed by thin layer chromatographic analysis of the conditioned medium obtained
after the growth wherein a significant reduction of PUR-diol was observed compared to non-inoculated medium. To quantify the
PUR-diol degradation, a sensitive assay based on High Performance Thin Layer Chromatography has been developed that showed
32% degradation of PUR-diol by the organism in 10 days. Degradation kinetics showed the maximal depletion of PUR-diol during
logarithmic growth of the organism indicating a direct relation between the growth and PUR-diol degradation. Mutagenic study
and GC-MS analysis revealed that esterase activity is involved in this degradation event. The ribotyping and metabolic fingerprinting
analysis showed that this organism is a strain of Pseudomonous aeruginosa (P. aeruginosa). It has also been observed that this strain is able to degrade Impranil DLN™, a variety of commercially available PUR. Therefore
this study identifies a new bacterium from soil that has the potential to reduce PUR-related waste burden and adds a new facet
to diverse functional activities of P. aeruginosa. 相似文献
12.
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
13.
Li Zheng Xiaojun Yan Jilin Xu Haimin Chen Wei Lin 《Applied Biochemistry and Microbiology》2005,41(1):29-33
Among marine bacteria isolated from the cytotoxic sponge Hymeniacidon perleve, one strain NJ6-3-1 classified as Pseudomonas sp. showed both cytotoxic and antimicrobial activities. Fatty acid analysis indicated that the bacterial strain consists mainly of C16:1, C16:0, C18:1, C18:0, C15:0, C14:0. One unusual 9,10-cyclopropane-C17:0 fatty acid and C26:0 also constitute major components, as well as the existence of squalene, the precursor of triterpenoids. The major metabolites in the culture broth were identified as alkaloids, including diketopiperazines and indole compounds, namely 3,6-diisopropylpiperazine-2,5-dione, 3-benzyl-3-isopropylpiperazine-2,5-dione, 3,6-bis-(2-methylpropyl)-piperazine-2,5-dione, indole-3-carboxaldehyde, indole-3-carboxylic acid methyl ester, indole-3-ethanol, and quinazoline-2,4-dione.From Prikladnaya Biokhimiya i Mikrobiologiya, Vol. 41, No. 1, 2005, pp. 35–39.Original English Text Copyright © 2005 by Li Zheng, Xiaojun Yan, Jilin Xu, Haimin Chen, Wei Lin.This article was submitted by the authors in English. 相似文献
14.
Lijuan Jiang Liuyan Yang Lin Xiao Xiaoli Shi Guang Gao Boqiang Qin 《Hydrobiologia》2007,581(1):161-165
Phosphorus release from Microcystis aeruginosa and attached bacterium (Pseudomonas sp.) isolated from Lake Taihu was examined using a phosphorus isotope tracer in order to investigate the phosphorus transference
between the two species. Our results reveal that the amount of phosphorus released form 32P-saturated M. aeruginosa is determined by its growth phase and most of phosphorus is assimilated by Pseudomonas finally while the amount of phosphorus released from 32P-saturated Pseudomonas is also determined by the growth phase of M. aeruginosa and most of them are assimilated by M. aeruginosa. The results suggest that phosphorus transference occurs between M. aeruginosa and its attached Pseudomonas . This process makes microenvironment of mucilage of M. aeruginosa attached bacteria maintain relative high amounts of phosphorus. Attached bacteria may be a temporary phosphorus bank to the
growth of M. aeruginosa, and assimilation of phosphorus by M. aeruginosa becomes easy when M. aeruginosa is in lag growth phase. Thus, the phosphorus exchange between M. aeruginosa and attached Pseudomonas in microenvironment may be important to microfood web and cyanobacteria bloom. 相似文献
15.
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
16.
Thomas P. West 《Antonie van Leeuwenhoek》2010,97(3):307-311
Control of pyrimidine formation was examined in Pseudomonas fulva ATCC 31418. Pyrimidine supplementation lowered pyrimidine biosynthetic pathway enzyme activities in cells grown on glucose
or succinate as a carbon source indicating possible repression of enzyme synthesis. Pyrimidine limitation experiments were
conducted using an orotidine 5′-monophosphate decarboxylase mutant strain isolated in this study. Compared to uracil-supplemented,
glucose-grown mutant cells, pyrimidine limitation of this strain caused aspartate transcarbamoylase, dihydroorotase, dihydroorotate
dehydrogenase and orotate phosphoribosyltransferase activities to increase about 6-, 13-, 3-, 15-fold, respectively, which
confirmed regulation of enzyme synthesis by pyrimidines. At the level of enzyme activity, transcarbamoylase activity in Ps. fulva was strongly inhibited by pyrophosphate, CTP, GTP and GDP under saturating substrate concentrations. 相似文献
17.
18.
A novel nicotine-degrading Pseudomonas sp. strain, HZN6, was isolated from a pesticide-wastewater treatment facility in Hangzhou. The strain could grow on nicotine
as its sole source of carbon, nitrogen, and energy. The strain’s main intermediate metabolites were determined to be pseudooxynicotine,
3-succinoyl-pyridine (SP), and 6-hydroxy-3-succinoyl-pyridine (HSP). A Tn5 transposon mutant was generated in which the degradation
pathway was blocked at the SP. A 4,583-bp DNA fragment flanking the transposon insertion site was obtained through self-formed
adaptor PCR and analyzed. The mutant gene orfC displays 89% deduced amino acid sequence identity with the sirA-like gene (sirA2, a sulfurtransferase homologue gene) of Pseudomonas stutzeri A1501. The orfC-disrupted strain lost the ability to degrade SP, and the complementation strains with the orfC from the Pseudomonas sp. HZN6 and the sirA2 (PP_1233) from Pseudomonas putida KT2440 recovered the degradation ability. Though the orfC-disrupted strain also lost the xanthine dehydrogenase activity, the effects of tungsten on the degradation of SP and hypoxanthine
revealed that the hydroxylation of SP to HSP was not a xanthine dehydrogenase type. These results demonstrated that the orfC gene was essential for the SP metabolism involved in the nicotine metabolic pathway in the Pseudomonas sp. HZN6 strain. This study might advance the understanding of the nicotine metabolic mechanism in Pseudomonas. 相似文献
19.
Pseudomonas
fluorescens-CS2 metabolized ethylbenzene as the sole source of carbon and energy. The involvement of catechol as the hydroxylated intermediate
during the biodegradation of ethylbenzene was established by TLC, HPLC and enzyme analysis. The specific activity of Catechol
2,3-dioxygenase in the cell free extracts of P.
fluorescens-CS2 was determined to be 0.428 μmoles min−1 mg−1 protein. An aqueous-organic, Two-Phase Batch Culture System (TPBCS) was developed to overcome inhibition due to higher substrate
concentrations. In TPBCS, P. fluorescens-CS2 demonstrated ethylbenzene utilization up to 50 mM without substrate inhibition on inclusion of n-decanol as the second phase. The rate of ethylbenzene metabolism in TPBCS was found enhance by fivefold in comparison with
single phase system. Alternatively the alginate, agar and polyacrylamide matrix immobilized P. fluorescens-CS2 cells efficiently degraded ethylebenzene with enhanced efficiency compared to free cell cultures in single and two-phase
systems. The cells entrapped in ployacrylamide and alginate were found to be stable and degradation efficient for a period
of 42 days where as agar-entrapped P. fluorescens was stable and efficient a period of 36 days. This demonstrates that alginate and polyacrylamide matrices are more promising
as compared to agar for cell immobilization. 相似文献
20.
Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes. 相似文献