苯酚降解菌株GXY-1分离鉴定、降解及其粗酶特性研究

Research on isolation,identification of a phenol-degrading strain GXY-1 and characteristics of its degradation and crude enzyme

从处理石化废水的活性污泥样品中分离得到一株能以苯酚为唯一碳源生长的菌株GXY-1.通过形态特征、生理生化及16S rDNA序列分析,初步鉴定菌株GXY-1属于布鲁氏杆菌属(Brucella sp.).实验结果表明,菌株GXY-1对土霉素和四环素不敏感,其降解苯酚的最佳条件为温度30℃,pH7.0.在最佳条件下,GXY-1对600mg/L苯酚的降解率在60h时达99%以上.同时GXY-1还可以利用苯胺、萘、氯苯等芳香化合物为唯一碳源生长.测定了降解途径中相关酶的活性,表明菌株GXY-1是通过邻苯二酚1,2双加氧酶催化开环来降解苯酚.该菌株粗酶的最适反应pH为7.8,最适反应温度为40℃.

A strain which can utilize phenol as sole carbon source is isolated from activated sludge of petrochemical wastewater and identified as Brucella sp. GXY-1 according to morphological,physiological and biochemical characteristics and 16S rDNA sequence analysis. The experimental results suggest that the strain can tolerate oxytetracycline and tetracycline. The optimum conditions for the degradation of phenol are temperture 30 ℃,pH 7.0. Under the optimum conditions,GXY-1 can decompose over 99% of phenol （600 mg/L） within 60 h. GXY-1 is able to degrade other aromatic compounds,such as aniline,naphthalene and chlorobenzene. Determination of enzymes activities in the degradation process indicates that the degradation of phenol is catalyzed by catechol 1,2-dioxygenase. The optimum conditions for the enzymatic reaction are pH 7.8 and 40 ℃.