嗪草酮降解菌Rhodococcus sp.MA的降解特性及固定化应用  

Degradation characteristics and immobilization application of metribuzin-degrading strain Rhodococcus sp.MA

作　　者：张浩 滑紫微 牛秋红[1] 惠丰立[1] 董维亮 周杰 陈兆进 李娜 ZHANG Hao;HUA Ziwei;NIU Qiuhong;HUI Fengli;DONG Weiliang;ZHOU Jie;CHEN Zhaojin;LI Na(School of Life Science and Technology,Nanyang Normal University,Nanyang 473061;College of Biotechnology and Pharmaceutical Engineering,Nanjing Tech University,Nanjing 211816;School of Agricultural Engineering,Nanyang Normal University,Nanyang 473061)

机构地区：[1]南阳师范学院生命科学与技术学院,南阳473061 [2]南京工业大学生物与制药工程学院,南京211816 [3]南阳师范学院农业工程学院,南阳473061

出　　处：《环境科学学报》2020年第6期2101-2110,共10页Acta Scientiae Circumstantiae

基　　金：河南省能源微生物资源可持续利用创新型科技团队项目;河南省高等学校重点科研项目(No.20A180020);南阳师范学院高层次人才科研启动费资助项目(No.2019ZX015,2019ZX013)。

摘　　要：从农田土壤中分离得到1株嗪草酮高效降解菌株,命名为MA,该菌5 d对50 mg·L^-1嗪草酮的降解率达到74.8%,最适反应温度和pH分别为30℃和7.0.根据表型与生理生化特征及16S rRNA序列分析,将其鉴定为Rhodococcus sp.MA.利用气相色谱-质谱联用(GC-MS)鉴定菌株MA降解嗪草酮的中间产物为脱氨基嗪草酮.以海藻酸钠为包埋剂,经正交试验表明,3%海藻酸钠、2%CaCl2、包埋比8∶1和固定时间6 h条件下,菌株对嗪草酮的降解效率最高,为71.2%.将固定化菌体细胞用于修复实验,结果表明,未固定化处理的菌液对湖水及池塘水中嗪草酮(15 mg·L^-1)的去除率分别为72.1%和69.9%;固定化处理后可提高对嗪草酮的去除率,分别达到87.3%和82.6%,具有良好的应用前景.Strain MA was isolated from farmland soil,which was capable of degrading 74.8%of 50 mg·L^-1 within 5 d.The optimum degradation temperature and pH were 30℃and 7.0,respectively.Strain MA was identified as Rhodococcus sp.MA based on morphological observation,physiological characteristics and its 16 S rRNA gene sequence.The degradation product of metribuzin was identified as deamino-metribuzin by GC-MS.The orthogonal test results showed that the degradation efficiency of metribuzin was the highest(71.2%)when using 3%sodium alginate as the embedding agent,2%CaCl2,embedding ratio of 8:1 and fixed time of 6 h.When unimmobilized bacteria were used in the bioremediation experiment,the removal rates of metribuzin in lake and pond water(15 mg·L^-1)were 72.1%and 69.9%,respectively.The removal rates were increased to 87.3%and 82.6%,respectively with immobilized bacteria,suggesting promising application prospect in bioremediation area.

关 键 词：嗪草酮 Rhodococcus sp.MA 代谢途径 固定化细胞 水体修复 

分 类 号：X172[环境科学与工程—环境科学] X524