摘要
为了能够得到高效降解二甲基二硫醚(Dimethyl disulfide,DMDS)的菌种资源,降低其残留在环境中带来的不利影响,从苏州某废弃农药厂附近的土壤中分离、纯化出一株能够降解DMDS的细菌,并对该细菌进行分子生物学和生理生化鉴定,研究其在不同的初始浓度、转速、pH、温度及外加碳氮源条件下的降解性能。结果表明:将分离纯化得到的DMDS降解菌命名为SZT-1,经过表型分析及16S rDNA基因序列同源性比对鉴定,该菌株序列与芽孢杆菌属(Bacillus Cohn)有98%以上的同源性。SZT-1菌株可以在以DMDS为唯一碳源的无机盐培养基中生长,56 h后进入生长稳定期。经摇床接种培养和一级动力学分析,接种SZT-1可以有效提高DMDS的降解速率,使其半衰期由346.5 h缩短至86.6 h^(-1)通过单因素环境条件分析,该菌株在DMDS初始浓度为250mg·L^(-1),转速为130 r·min^(-1),pH为5,温度为30℃,外加碳源为淀粉,外加氮源为蛋白胨时,对DMDS的降解效果最佳,降解率达50%。试验首次提出了SZT-1对DMDS具有一定的降解效果,在进行相关技术完善后,有望用于治理土壤、地下水中DMDS带来的危害。
To obtain dimethyl disulfide(DMDS) strain resources efficiently and reduce the adverse effects of its residues in the environment, this study isolated and purified a bacterium capable of degrading DMDS in the soil near an abandoned agricultural pharmaceutical factory in Suzhou. The molecular biology, physiological, and biochemical identification of bacteria were performed to study their degradation performance under different initial concentrations, rotational speeds, pH, temperature, and added carbon and nitrogen sources. The bacterium was named SZT-1, and the bacterial gene sequence had a 98% homology with Bacillus sp. based on phenotypic analysis and homology comparison using BLAST and 16S rDNA identification. The SZT-1 strain grew on a mineral medium with a sole carbon source of DMDS and reached a stable growth stage after 56 h. The strain effectively degraded DMDS based on flask-shaking culture and order 1 dynamic analysis where the halftime of DMDS degradation was decreased from 346.5 h to 86.6 h. The maximal DMDS degrading rate(approximately 50%)was measured using environmental condition single factor analysis at an initial concentration of 250mg·L^(-1) DMDS, rotation speed of 130 r·min^(-1), pH of 5, temperature of 30 ℃, exogenously addition of starch as the carbon source and peptone. To date, little is known regarding DMDS biodegradation, with the findings from this study of SZT-1 degrading DMDS the first reported. This study provides a reference for the biodegradation of VOC odor pollutants that could be used to control and decrease the harm by DMDS in the soil and groundwater environment in the future.
作者
丁军
吴洪生
孙倩
王娜
程诚
石陶然
MuhammadFaheem
倪妮
田伟
吴云成
单正军
DING Jun;WU Hongsheng;SUN Qian;WANG Na;CHENG Cheng;SHI Taoran;MuhammadFaheem;NI Ni;TIAN Wei;WU Yuncheng;SHAN Zhengjun(Department of Agricultural Resources and Environment,College of Applied Meteorology,Nanjing University of Information Science and Technology,Nanjing 210044,China;Nanjing Institute of Environmental Sciences,Ministry of National Ecology and Environment of China,Nanjing 210012,China)
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2022年第3期622-630,共9页
Journal of Agro-Environment Science
基金
国家重点研发计划项目(2019YFC1806100)。
关键词
二甲基二硫醚
降解菌
16S
rDNA
分离
鉴定
降解特性
dimethyl disulfide(DMDS)
degrading microbe
16S rDNA
isolation
identification
degrading characters