一株丁草胺降解菌的分离鉴定及培养条件优化

Isolation and identification of a butachlor degrading bacterium and optimization of its growth conditions

利用富集培养技术从长期施用丁草胺的稻田土壤中分离得到1株能够降解丁草胺的细菌,标记为LYC-2.经形态特征、生理生化特征和16SrDNA序列分析,将该菌株鉴定为钩杆菌属(Ancylobacter sp.).同时,为探索菌株LYC-2的生长特性和最佳培养条件,利用正交试验设计法考察了接种量、温度、pH值3个因素对菌株LYC-2生长的影响.结果表明,菌株LYC-2的最适生长温度为35℃,最适pH值为7.5.当接种量为6%(体积分数,下同)时,该菌株在含100mg.L-1的丁草胺无机盐基础培养液中培养5d后,可使丁草胺降解率达90.85%以上.

A butachlor-degrading strain LYC-2 was isolated from a paddy soil sample by enrichment culture.According to morphologic and physiobiochemical characteristics as well as 16S rDNA sequence analysis,strain LYC-2 was identified as an Ancylobacter sp.Effects of inoculation rate （V/V）,temperature and pH on the growth of the butachlor-degrading strain were examined using an orthogonal experiment.The results showed that the optimal inoculation rate was 6% （V/V） in mineral medium containing 100 mg·L^-1 butachlor,at 35℃ and pH 7.5.Under these conditions,more than 90.85% butachlor was degraded by LYC-2 in 5 days.