具多氯联苯降解特性绦柳内生菌的分离筛选及其移除性能

Isolation and characterization of polychlorinated biphenyl-degrading endophytic bacterium from Salix matsudana f. pendula

从室外生长的绦柳和绦柳组培苗中共分离纯化出12株不同的内生菌。通过利用Aroclor 1242为唯一碳源生长试验筛选出生长良好的菌株CGL-1。经菌落形态学、细胞形态学和16S r DNA序列同源性分析,菌株CGL-1为肠杆菌属。通过改变菌株的移除条件(接菌量、p H、盐含量)可知,菌株CGL-1最适移除Aroclor 1242接菌量为10%,p H为7。在此条件下,利用气相色谱(GC-ECD)检测菌株CGL-1对Aroclor 1242的移除效果,发现菌株CGL-1对Aroclor 1242中的每个组分都有明显的移除作用,7 d总移除率为43.2%。

A total of 12 different endophytic bacterial strains were isolated from Salix matsudana f. pendula in garden and its tissue culture seedlings in this study. Endophytic bacterial strain CGL-1 was identified by using Aroclor 1242 as the only carbon source to grow well. The characteristics of 16 S ribosomal DNA sequences and morphology of colony and cell suggested that this isolate was most closely related to the genus Enterobacter. The optimal conditions of Aroclor 1242 degradation were obtained according to the changes of inoculation amount of the bacterium,p H and the concentration of Na Cl in liquid minimal media. The inoculation amount of 10% of CGL-1at p H 7.0 appeared to be the optimum conditions for removing Aroclor 1242. Under these conditions,GC-ECD was used to measure removal effects of Aroclor 1242 by domesticated strain CGL-1. The results indicated that Aroclor 1242 congeners were obviously removed by strain CGL-1,with a total removal rate of 43.2% after 7 d.