摘要
采用添加有机磷农药的选择性培养基,在长期受有机磷农药污染的土壤中分离到7株有机磷农药降解菌,经生理生化鉴定和系统发育分析,菌株mp-1鉴定为Pseudaminobactersp.,菌株mp-2为Alcaligenessp.,菌株mp-7为Brucellasp.,其他菌株为Ochrobactrumsp.。16SrDNA序列同源性比较、系统发育分析和染色体ERIC-PCR指纹图谱扩增表明有机磷农药长期污染的土壤中有机磷农药降解菌具有丰富的多样性。
Seven organophosphate pesticide-degrading bacteria, namely mp-1 to mp-7, were isolated from a long-term organophosphate pesticide-contaminated soil using selective culture medium with organophosphate pesticide as the sole carbon and energy source. Comparative studies were performed on their morphological, physiological and biochemical characteristics. The genomic DNA of the seven bacteria was extracted by the method of high-salt-concentration precipitation and their 16S rDNA was amplified with the bacterial universal primers. The amplified products were purified and the 1.5 kb fragments were ligated into the pMD 18-T plasmid vector. Recombinant plasmids were transformed into competent E. coli DH5α cells, and the inserted fragments were sequenced. The 16S rDNA sequences were compared and the similarities between them were calculated, which ranged from 76.31% to 99.79%, displaying a wide diversity of organophosphate pesticide-degrading bacteria in this contaminated soil. 16S rDNA sequences were also compared with those from GenBank using Blast software package and phylogenetic tree was constructed using PHYLIP. Based on the phylogenetic analysis and physiological and biochemical characteristics, strains mp-1, mp-2 and mp-7 belonged to the genus of Pseudaminobacter sp., Alcaligenes sp., and Brucella sp., respectively while all other strains were members of Ochrobactrum sp. No organophosphate pesticide-degrading bacterium has been reported from these genera. The biodiversity of the seven organophosphate pesticide-degrading bacteria were also revealed by comparing their genomic ERIC-PCR (enterobacterial repetitive intergenic consensus) fingerprints. Each of them has distinctive ERIC-PCR fingerprint. This work furthers our understanding of the degrading ability of indigenous microorganisms in the contaminated soil environment, and provides the foundation to study the ecology of organophosphate pesticide-degrading bacteria and the disseminated mechanism of the organophosphate hydrolase gene.
出处
《生态学报》
CAS
CSCD
北大核心
2005年第6期1502-1508,共7页
Acta Ecologica Sinica
基金
国家"十五"攻关资助项目(2002BA516A01)
国家"863"资助项目(2003AA241150)
国家自然科学基金资助项目(30400014)~~
关键词
有机磷农药
降解菌
系统发育
ERIC-PCR指纹图谱
多样性
organophosphate pesticides
degrading bacteria
phylogenetic analysis
ERIC-PCR finger profiles
diversity
