Li Zhaoxia, Niu Xian, He Wenyi, Tong Yanyan, Jin Hui, Ding Cheng
School of Chemical and Biological Engineering, Yancheng Institute of Technology, Yancheng 224051, China.
Wei Sheng Wu Xue Bao. 2013 May 4;53(5):455-63.
We screened a bacterial strain capable of degrading chlorobenzene, and purified the corresponding degradation enzyme.
The strain was screened by gradient enrichment culture and sterile filter paper plate method, and identified by morphology and 16S rRNA gene sequence. Chlorobenzene concentration in the liquid culture was determined by gas chromatography. Degradation capability was assayed by the proportion of chlorobenzene degraded per cells. The purity quotient and molecular weight of the purified degradation enzyme were determined by gel per cell. electrophoresis.
The isolated bacterium, LW13, used chlorobenzene in activated sludge as sole carbon and energy source. Cells were 2.3 microm long and 0.8 microm wide, with several terminal flagella. Strain LW13 was 95.5% similar to Lysinibacillus fusiformis, and its degradation enzyme was a positively-charged exoenzyme (molecular weight about 57 kDa). The optimal temperature and pH of the purified enzyme were approximately 40 degrees C and 8.0, respectively.
Strain LW13 belongs to genus Lysinibacillus, and can degrade chlorobenzene (500-2000 mg/L).
筛选出一株能够降解氯苯的菌株，并纯化相应的降解酶。
通过梯度富集培养和无菌滤纸平板法筛选该菌株，并通过形态学和16S rRNA基因序列进行鉴定。采用气相色谱法测定液体培养物中的氯苯浓度。通过每细胞降解氯苯的比例来测定降解能力。采用凝胶电泳法测定纯化后降解酶的纯度系数和分子量。
分离得到的菌株LW13以活性污泥中的氯苯作为唯一碳源和能源。细胞长2.3微米，宽0.8微米，有几根端生鞭毛。菌株LW13与梭形赖氨酸芽孢杆菌的相似度为95.5%，其降解酶是一种带正电荷的胞外酶（分子量约57 kDa）。纯化后酶的最适温度和pH分别约为40℃和8.0。
菌株LW13属于赖氨酸芽孢杆菌属，能够降解氯苯（500 - 2000 mg/L）。
