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排序方式: 共有871条查询结果,搜索用时 31 毫秒
461.
Wei Zhang Bo Yue Qi Wang Zechun Huang Qifei Huang Zengqiang Zhang 《环境科学学报(英文版)》2011,23(11):1770-1777
Different municipal solid waste landfill methods and landfill ages had crucial impacts on bacterial abundance and composition in leachate. 相似文献
462.
Analysis of bacterial community in bulking sludge using culture-dependent and -independent approaches 总被引:1,自引:0,他引:1
Decai Jin Ping Wang Zhihui Bai Xinxin Wang Hong Peng Rong Qi Zhisheng Yu Guoqiang Zhuang 《环境科学学报(英文版)》2011,23(11):1880-1887
Combination of 16S rRNA gene clone library and cultivation for assessing of bacterial diversity of the microflora in bulking sludge was evaluated in the study. 相似文献
463.
Microorganisms, plants, and animals have successfully colonized cold environments, which represent the majority of the biosphere
on Earth. They have evolved special mechanisms to overcome the life-endangering influence of low temperature and to survive
freezing. Cold adaptation includes a complex range of structural and functional adaptations at the level of all cellular constituents,
such as membranes, proteins, metabolic activity, and mechanisms to avoid the destructive effect of intracellular ice formation.
These strategies offer multiple biotechnological applications of cold-adapted organisms and/or their products in various fields.
In this review, we describe the mechanisms of microorganisms, plants, and animals to cope with the cold and the resulting
biotechnological perspectives. 相似文献
464.
用外源H2O2处理拟南芥植株,亚硫酸氢盐修饰后测序法分析胁迫生理中NIT2基因启动子区甲基化特征变化,RT-PCR检测该基因的转录水平.结果显示:用100#mol·L-1的H2O2处理3 h后,NIT2启动子区胞嘧啶总甲基化水平与对照差异不大,但对照组CHG(H为C、A或T)和CG位点甲基化水平分别为35.0%和93.3%,H2O2处理组CHG和CG位点甲基化水平分别为50.0%和96.9%;H2O2处理组CHH位点则表现为甲基化水平升高、降低或去甲基化;H2O2胁迫组拟南芥地上组织中NIT2基因转录水平提高.研究结果表明:NIT2基因的转录应答和DNA甲基化修饰参与了植株的逆境生理过程;氧化胁迫与DNA甲基化改变、基因转录上调同时发生,说明胁迫诱发的活性氧增高可能参与胞嘧啶甲基化修饰和基因转录的调节. 相似文献
465.
碱性磷酸酶(APase)是最主要的有机磷水解酶,在无机磷匮乏的情况下,APase释放的无机磷供藻类利用,致使藻类大量繁殖,因此,对APase基因多样性的研究有利于揭示对水体富营养化有重要影响的微生物类群.基于此,本文以珠江水体为研究对象,构建了珠江广州段穗石、坦尾和南沙3个点细菌的pho D基因克隆文库.限制性酶切片段多态性(RFLP)分析结果表明,上述3个点的pho D基因分别含有15、17、13个操作分类单元(Operational Taxa Unit,OTU),穗石点的多样性(Shannon指数和Simpson指数)均高于其他两个点;pho D基因序列系统发育分析表明,珠江水体中pho D基因主要来源于Plesiocystis、Limnohabitans、Pirellula等属的细菌,而Limnohabitans属的pho D基因在文库中含量最高,占文库的44%~50%.研究表明,珠江水体中细菌的pho D基因具有较高的多样性,这些基因编码的碱性磷酸酶可能在珠江水体的富营养化过程中有重要的作用. 相似文献
466.
Zhenyu Wang Feng Pan Abd El-Latif Hesham Yingxin Gao Yu Zhang Min Yang 《环境科学学报(英文版)》2015,37(11):192-199
The purpose of this study was to reveal how activated sludge communities respond to influent quality and indigenous communities by treating two produced waters from different origins in a batch reactor in succession. The community shift and compositions were investigated using Polymerase Chain Reaction–denaturing gradient gel electrophoresis(PCR–DGGE) and further16 S ribosomal DNA(r DNA) clone library analysis. The abundance of targeted genes for polycyclic aromatic hydrocarbon(PAH) degradation, nah Ac/phn Ac and C12O/C23 O, was tracked to define the metabolic ability of the in situ microbial community by Most Probable Number(MPN) PCR. The biosystem performed almost the same for treatment of both produced waters in terms of removals of chemical oxygen demand(COD) and PAHs. Sludge communities were closely associated with the respective influent bacterial communities(similarity 60%), while one sludge clone library was dominated by the Betaproteobacteria(38%) and Bacteriodetes(30%)and the other was dominated by Gammaproteobacteria(52%). This suggested that different influent and water quality have an effect on sludge community compositions. In addition, the existence of catabolic genes in sludge was consistent with the potential for degradation of PAHs in the treatment of both produced waters. 相似文献
467.
Cloning and expression of the first gene for biodegrading microcystin LR by Sphingopyxis sp. USTB-05
Hai Yan Huasheng Wang Junfeng Wang Chunhua Yin Song M Xiaolu Liu Xueyao Yin 《环境科学学报(英文版)》2012,24(10):1816-1822
Harmful cyanobacterial blooms are a growing environmental problem worldwide in natural waters, the biodegradation is found to be the most efficient method for removing microcystins (MCs) produced by harmful cyanobacteria. Based on the isolation of a promising bacterial strain of Sphingopyxis sp. USTB-05 for biodegrading MCs, we for the first time cloned and expressed a gene USTB-05-A (HM245411) that is responsible for the first step in the biodegradation of microcystin LR (MC-LR) in E. coli DH5αup, with a cloning vector of pGEM-T easy and an expression vector of pGEX-4T-1, respectively. The cell-free extracts (CE) of recombinant E. coli DH5αup containing USTB-05-A had high activity for biodegrading MC-LR. The initial MC-LR concentration of 40 mg/L was completely biodegraded within 1 hr in the presence of CE with a protein concentration of 0.35 mg/mL. Based on an analysis of the liquid chromatogram-mass spectrum (LC-MS), the enzyme encoded by gene USTB-05-A was found to be active in cleaving the target peptide bond between 3-amino-9-methoxy-2,6, 8-trimethyl-10-phenyl-deca-4,6-dienoic acid (Adda) and arginine of MC-LR, and converting cyclic MC-LR to linear MC-LR as a first product that is much less toxic than parent MC-LR, which offered direct evidence for the first step on the pathway of MC-LR biodegradation by Sphingopyxis sp. USTB-05. 相似文献
468.
Strain JII screened out from different odor origins can efficiently degrade methyl mercaptan and ethanethiol whereas has no ability to remove dimethyl sulfide. The results indicated that the strain JII breaks only the C-SH bond. The optimum temperature and pH of JII are 20-30℃ and 6.0-8.3 respectively. A systematic identificatio nmethod-16S rDNA gene sequence comparison, for deodorizing bacteria was carried out. The 16S rDNA gene sequence analysis of strain JII showed the highest level of 97 % homology to Rape rhizosphere. 相似文献
469.
470.