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环境中污染物降解基因的水平转移(HGT)及其在生物修复中的作用 总被引:2,自引:0,他引:2
水平基因转移是不同于垂直基因转移的遗传物质的交流方式.在污染环境这一特异生态环境中,降解基因的水平转移有着独特的功能与作用.研究环境中污染物降解基因在微生物间的水平转移,更深入地了解微生物种群适应污染环境的机理,对于评价污染物的环境毒理、生物可降解性以及污染环境的可修复潜力具有重要参考价值.在污染物生物修复实践中,可以通过调控降解基因的水平转移,增强污染环境中微生物的降解能力,更有效地发挥生物修复作用.文章将对环境中细菌间基因交流的机制,污染物降解基因的水平转移对微生物适应污染环境的机理、水平基因转移对代谢途径的进化及其对污染物生物修复作用的影响等方面的研究进展做一综述. 相似文献
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产电和污染物降解是微生物燃料电池(Microbial Fuel Cells,MFCs)的两个基本功能,也是MFCs作为一种新型的环境治理和能源技术最具吸引力的优势。大量的研究已表明:相对于一般厌氧生物降解技术,MFCs具有更高效的废弃物、废水或污染物降解的能力。解析MFCs强化污染物降解的机理对于进一步优化MFCs的性能具有重要的指导意义,也可以为MFCs在实际环境中的原位应用提供理论支持。本文在综述MFCs强化污染物降解研究报道的基础上,从MFCs中微生物群落的代谢模式、生物膜的活性以及MFCs对局部氧化还原环境的影响等方面为MFCs强化污染物降解的功能提供可能的理论依据,并对MFCs在污染物降解方面的几个可能的发展方向进行展望,为不同学科背景的相关研究者提供参考。 相似文献
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可移动基因元件(mobile genetic elements,MGEs)在环境微生物群落中的水平转移是细菌基因组进化和适应特定环境压力的重要机制.在污染土壤和水体中接种携带具有降解基因MGEs的菌株后,随着MGEs的水平基因转移,可使降解基因转移至具有竞争性的土著微生物中并在其中表达,从而不必考虑供体菌在环境中是否能够长期存活.这种由可移动降解基因元件水平转移介导的生物修复为探索新的生物修复途径提供了可行性.本文重点综述了环境样品中携带降解基因MGEs的多样性及其在促进污染物降解过程中的重要作用,介绍了从环境样品中分离代谢MGEs的方法,并列举了在污染土壤、活性污泥、其他生物反应器等生态系统中MGEs水平转移的几个实例. 相似文献
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FISH技术在强化生物除磷中的应用 总被引:1,自引:0,他引:1
荧光原位杂交(FISH)是一种微生物生态学研究技术,在强化生物除磷(EBPR)过程中,用来鉴定系统中的优势微生物种群,直接观察其在污泥系统中的形态结构、分布状态,跟踪监测其各个阶段的动态变化,并将其量化。与DGGE/TGGE、SSCP、RFLP、DAPI染色等研究方法,可突破FISHj技术不能提供活性污泥内部种群多样性、检测"未知"微生物的研究局限,增加研究的准确性。发展探针检测水平、发现更有效的染色鉴定方法、与生理生化研究相结合将成为FISH技术在强化生物除磷过程中的发展方向。 相似文献
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石油污染土壤的生物刺激和生物强化修复 总被引:6,自引:0,他引:6
随着工业化的发展,土壤的石油污染问题日益严重,石油污染物的处理已成为各国亟待解决的环境问题。由于生物修复具有高效、安全、成本低、无二次污染等诸多优点而成为近些年来主要的石油污染处理方法。概述了生物刺激和生物强化处理方法的基本原理,以及近年来国内外相关的研究进展。生物刺激和生物强化是生物修复法中最常用的两类方法,而且生物强化通常比生物刺激的效率高,但两者处理效率的高低均与多方面的因素有关,因此在实际应用中应注意考虑多方面的效益,制定出较合理的处理方案。 相似文献
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Pseudomonas putida strain BNF1 was isolated to degrade aromatic hydrocarbons efficiently and use phenol as a main carbon and energy source to support its growth. Catechol 2,3-dioxygenase was found to be the responsible key enzyme for the biodegradation of aromatic hydrocarbons. Catechol 2,3-dioxygenase gene was cloned from plasmid DNA of P. putida strain BNF1. The nucleotide base sequence of a 924 bp segment encoding the catechol 2,3-dioxygenase (C23O) was determined. This segment showed an open reading frame, which encoded a polypeptide of 307 amino acids. C23O gene was inserted into NotI-cut transposon vector pUT/mini-Tn5 (Kmr) to get a novel transposon vector pUT/mini-Tn5-C23O. With the helper plasmid PRK2013, the transposon vector pUT/mini-Tn5-C23O was introduced into one alkanes degrading strain Acinetobacter sp. BS3 by triparental conjugation, and then the C23O gene was integrated into the chromosome of Acinetobacter sp. BS3. And the recombinant BS3-C23O, which could express catechol 2,3-dioxygenase protein, was obtained. The recombinant BS3-C23O was able to degrade various aromatic hydrocarbons and n-alkanes. Broad substrate specificity, high enzyme activity, and the favorable stability suggest that the BS3-C23O was a potential candidate used for the biodegradation of crude oil. 相似文献
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Gregg Bogosian Patricia J. L. Morris Michael D. Hale James F. Kane 《Journal of industrial microbiology & biotechnology》1992,9(1):27-36
Summary The fate in water ofEscherichia coli K-12 strain LBB269, both plasmid-free and carrying the recombinant plasmid pBGH1, was studied.E. coli K-12 strain LBB269 (pBGH1) is a nalidixic acid resistant derivative of W3110G (pBGH1), the microorganism used by Monsanto Company for the commercial production of bovine somatotropin. Water samples were obtained from the Missouri River and from the Monsanto Life Sciences Research Center aqueous waste basin. Strains LBB269 and LBB269 (pBGH1) were grown in fermentation vessel under bovine somatotropin (BST) production conditions, and inoculated into the water samples. The inoculated water samples were incubated, at 26°C, and the number of viableE. coli cells was determined as a function of time. In sterile water from both sources, the two strains remained, at a constant level for at least 28 days; LBB269 (pBGH1) remained at a constant level in sterile water for at least 300 days. In non-sterile water from both sources, the two strains declined from an initial concentration of about 3.0×106 cells per ml to less than 10 cells per ml in 147 h. The study conditions did not adversely affect the populations of indigenous microorganisms. The selective loss of strains LBB269 and LBB269 (pBGH1) demonstrates that theseE. coli strains do not survive in environmental sources of water. In addition, it was observed that the presence of pBGH1 had essentially no effect on the disappearance of strain LBB269 from either source of water. 相似文献
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Ruo-fei Jin Ji-ti Zhou Ai-li Zhang Jing Wang 《World journal of microbiology & biotechnology》2008,24(1):23-29
The study showed that the genetically engineered microorganism (GEM) bioaugment successfully the dye wastewater biotreatment
systems to enhance acid red GR (ARGR) removal. Escherichia coli JM109 (pGEX-AZR) was the GEM with higher azoreductase activity. The kinetics of the ARGR decolorization by the E. coli JM109 (pGEX-AZR) agreed with Andrews model. The kinetic parameters, r
dye,max, K
s
and K
i
, were found to be 42.45 mg g−1 h−1, 584.93 mg L−1 and 556.89 mg L−1, respectively. The E. coli JM109 (pGEX-AZR) was tested in anaerobic sequencing batch reactors (AnSBR) in order to enhance the ARGR decolorization. The
decolorization rate of ARGR was affected by the amount of E. coli JM109 (pGEX-AZR) inoculation and the best amount of inoculation was 10%. The continuous operations of the four bioreactors
with different E. coli JM109 (pGEX-AZR) immobilization supports showed that the E. coli JM109 (pGEX-AZR) could bioaugment decolorization in AnSBRs with suspended and immobilized on macroporous foam carriers. For
42 days continuous operation in the AnSBRs, both the tolerance to ARGR concentration shock and the decolorization rate in
these two bioaugmented AnSBRs are higher than those of the other two systems, control system and bioaugmented AnSBRs system
with the sodium-alginate immobilized cells, the decolorization rate reached 90%. Changes in microbial community were detected
by ribosomal intergenic spacer analysis (RISA) and amplified ribosomal DNA restriction analysis (ARDRA), which revealed that
the introduced E. coli JM109 (pGEX-AZR) was persistent in the augmented systems and maintained higher metabolic activity. 相似文献
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【目的】过表达酿酒酵母肌醇合成关键酶基因INO1,促进肌醇合成,构建能够分泌肌醇的基因工程菌株。【方法】构建r DNA介导的INO1基因多拷贝整合表达载体p URIH,电转化酿酒酵母Y01菌株,构建工程菌株YI2-1和YI2-2,荧光定量PCR方法分析INO1基因表达量。敲除Kan MX抗性基因,HPLC检测重组菌发酵液中肌醇含量。【结果】获得INO1基因过表达菌株YI2-1和YI2-2,YI2-1的INO1基因表达量是出发菌Y01的16.235倍。敲除Kan MX抗性基因的菌株命名为YI2-1△KP,初步检测YI2-1△KP产肌醇量为627 mg/L。【结论】r DNA介导的INO1基因多拷贝整合表达载体p URIH能够有效地过表达目的基因;过表达菌株合成的肌醇不仅能满足自身的需要,而且能够向胞外分泌,具有潜在的工业应用价值。 相似文献
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Jae Young Lee Yoo Jin Jang Ji Hyun Bae Yoon Hoo Lee Hee Sook Bae Seokjoong Kim Sin-Gi Park Ok Jae Koo Su Cheong Yeom 《Biochemistry and Biophysics Reports》2020
The Streptococcus pyogenes CRISPR/Cas9 (SpCas9) system is now widely utilized to generate genome engineered mice; however, some studies raised issues related to off-target mutations with this system. Herein, we utilized the Campylobacter jejuni Cas9 (CjCas9) system to generate knockout mice. We designed sgRNAs targeting mouse Tyr or Foxn1 and microinjected into zygotes along with CjCas9 mRNA. We obtained newborn mice from the microinjected embryos and confirmed that 50% (Tyr) and 38.5% (Foxn1) of the newborn mice have biallelic mutation on the intended target sequences, indicating efficient genome targeting by CjCas9. In addition, we analyzed off-target mutations in founder mutant mice by targeted deep sequencing and whole genome sequencing. Both analyses revealed no off-target mutations at potential off-target sites predicted in silico and no unexpected random mutations in analyzed founder animals. In conclusion, the CjCas9 system can be utilized to generate genome edited mice in a precise manner. 相似文献
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【目的】肌醇别名环己六醇,是一种具有生物活性的糖醇,在医药、食品和饲料等领域具有重要的应用价值。为获得生产肌醇的微生物细胞工厂,通过代谢工程改造,构建生产肌醇的酿酒酵母工程菌株。【方法】对酿酒酵母肌醇合成途径的正负调控同时改造,过表达肌醇-3-磷酸合成酶基因ino1,敲除肌醇生物合成的转录抑制子基因opi1和抗性基因kan MX,获得重组菌。利用气相色谱法检测重组菌发酵液中肌醇含量。【结果】构建了生物安全性的产肌醇基因工程菌株,摇瓶培养产量为1.021 g/L。【结论】通过过表达ino1和敲除opi1来改造酿酒酵母,能够有效提高重组菌的肌醇产量,为下一步的微生物发酵法产肌醇的工业应用奠定基础。 相似文献
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Studies were conducted using a 10-chamber Micro-Oxymax (Columbus, OH, USA) respirometer to determine the effect of bioaugmentation and biostimulation (by diverse ways of O2 supply) on enhancing biodegradation of oil hydrocarbons to reduce risk at a former military airport in Kluczewo, Poland. Indigenous or exogenous bacteria bioaugmentation was used to degrade hydrocarbons. Aerated water and/or aqueous solutions of H2O2 or KMnO4 were used to supply O2. The intrinsic and enhanced biodegradation was evaluated by the O2 uptake and CO2 production rates obtained using a linear regression of the cumulative O2 uptake and CO2 production curves. Generally, in all cases biodegradation rates enhanced by bioaugmentation were two to four times higher than the rates of intrinsic biodegradation. Moreover, application of indigenous bacteria was more efficient in comparison to the exogenous consortia. The highest CO2 production rates were achieved when aqueous solution of KMnO4 was applied, as the increase of CO2 production rates were about 71% to 97% higher compared to a control. The aqueous solution of H2O2 did not cause any significant improvement of the biodegradation rates. Compared to a control, the addition of aerated water resulted in a decrease of CO2 production rates. Most probably the excessive soil moisture could reduce the air-filled porosity and, consequently, the oxygen contents in soil. 相似文献