一株苯酚降解菌株的筛选鉴定及特性研究

Study on Screening, Identification and Characterization of A Phenol-degrading Bacterium Strain

为了从焦化废水活性污泥中筛选出高效降酚的细菌,以对废水中苯酚进行生物处理。以苯酚为唯一碳源,从太谷县某焦化厂活性污泥中筛选苯酚降解菌,同时通过Plackett-Burman试验设计,结合正交试验分析,确定该菌株降解苯酚的最佳条件,通过酶活性测定推测菌株降解途径。结果从活性污泥中分离得到1株苯酚降解菌株B10,经分析16S rDNA序列和构建系统进化树,初步鉴定该菌株为芽孢杆菌属细菌。通过利用Plackett-Burman试验设计,结合正交试验分析,确定该菌株降解苯酚的最佳条件为:酵母膏10 g·L^(-1),乙醇4 g·L^(-1),初始接菌量2.5%,培养温度30℃,硫酸镁1 g·L^(-1)。当以苯酚为唯一碳源时,菌株B10中仅有邻苯二酚1, 2-双加氧酶活性被检测到,因此推测,该菌株通过邻位途径降解苯酚。结果表明,B10菌具有降解苯酚能力,对于治理含酚废水具有应用潜力。

The purpose of this paper is to screen highly effective phenol-degrading bacteria from the activated sludge of coking wastewater for the treatment of phenol in wastewater. The paper took phenol as the sole carbon source, by utilizing phenol as sole carbon source, screening phenol-degrading bacteria from the active sludge of coking plant in Taigu county of Shanxi province, at the same time, the optimum conditions for degradation of phenol were determined by Plackett-Burman experimental design and orthogonal test analysis, and the degradation pathway of the strain was determined by enzyme activity detection. The results showed that a phenol-degrading bacterium strain B10 was isolated from the active sludge. Based on the analysis of the 16 S rDNA sequence and the construction of the phylogenetic tree, the strain was identified as Bacillus. Utilizing the Plackett-Burman design, together with orthogonal test analysis, it was confirmed that the optimum degradation conditions of the strain were yeast extract 10 g·L^（-1）, ethanol 4 g·L^（-1）,inoculation volume 2.5%, temperature 30 ℃, magnesium sulphate 1 g·L^（-1）. When phenol was the only carbon source, only catechol 1,2-dioxygenase activity in strain B10 was detected. Therefore, it was speculated that the strain might metabolize phenol via ortho-cleavage pathway. The results showed that B10 could degrade phenol and had potential application in the treatment of phenolic wastewater.