摘要
分离筛选到1株能以氯苯为唯一碳源和能源的菌株LW26,根据菌株的形态、生理生化特征、16S rRNA序列分析以及Biolog鉴定,确定该菌株为戴尔福特菌(Delftia tsuruhatensis),其为新发现的具有氯苯降解能力的菌株,并且该菌株能降解BETX、正己烷和环己烷等常见的有机污染物.实验考察了温度、pH、氯苯初始浓度、Cl-浓度等因素对菌株生长和降解性能的影响.结果表明,该菌株较为适宜的生长和降解条件为:温度25℃、pH 7.0;底物耐受浓度高达500 mg·L^(-1);当Cl-浓度超过0.14 mol·L^(-1)时,菌株生长会受到抑制.利用Haldane模型对实验数据拟合得到菌株LW26的最大比生长速率μmax和最大比降解速率γmax分别为0.42 h^(-1)和2.53 h^(-1).利用GC-MS进行中间产物分析,结果表明菌株LW26降解氯苯的过程中产生邻氯苯酚,结合邻苯二酚双加氧酶活性分析,推测氯苯经历邻位开环、脱氯、氧化等过程,最终矿化为CO2或转化为生物质.
A bacterium strain LW26 which could utilize chlorobenzene （CB） as sole carbon and energy source was isolated from a biotrickling filter reactor treating CB-contaminated off-gas. Based on its morphological and physiological characteristics, as well as the analysis of 16S rRNA gene sequence and Biolog test, the strain LW26 was identified as Delftia tsuruhatensis. To our best knowledge, it is the first time that the strain Delftia tsuruhatensis was applied for CB purification. In this study, the effects of temperature, pH, initial CB concentration and Cl ^- concentration on the biodegradation were investigated. The results showed that the optimal temperature and pH for CB biodegradation were 25℃ and 7. 0,respectively; the maximum CB tolerated concentration for LW26 was as high as 500 mg·L ^- 1; when the concentration of Cl ^- was above 0. 14 mol·L ^- 1 , the CB degradation was significantly restrained. The degrading process of the strain LW26 followed the Haldane kinetic model and the maximum specific growth rate and the maximum specific degradation rate were 0. 42 h ^- 1 and 2. 53 h ^- 1 , respectively. GC-MS analysis of the metabolites revealed that CB was firstly converted to o-chlorophenol by strain LW26. Combined with the activity of catechol dioxygenase, it can be speculated that CB was finally mineralized to CO2 , or converted to cell biomass after processes of ortho cleavage,dechlorination and oxidation.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2017年第2期802-808,共7页
Environmental Science
基金
国家自然科学基金项目(21276239)
浙江省公益技术应用研究项目(2015C33037)
浙江省教育厅项目(Y201329224)
关键词
氯苯
戴尔福特菌
生物降解
动力学
产物分析
chlorobenzene
Delftia tsuruhatensis
biodegradation
kinetics
metabolites analysis
