降解芘的分枝杆菌M11的分离鉴定和降解特性

Isolation,Identification of a Pyrene-Degrading Strain Mycobacterium sp.M11 and Its Degrading Characteristics

从多环芳烃污染的土壤中分离到1株能高效降解四环芳烃芘的放线菌M11,经形态观察、生理生化和16S rDNA鉴定,属于分枝杆菌属（Mycobacteriumsp.）.菌株M11能以菲、蒽、荧蒽和芘为唯一碳源生长,在含芘50、100和200 mg/L的无机盐液体培养基中培养16 d降解率分别达到76.9%、91.8%和79.23%.菌株M11对芘的降解具有较广泛的pH范围,在芘浓度100 mg/L,pH为5-9的液体条件下,均可生长.根据已报道的芘降解菌的双加氧酶同源序列设计引物,PCR扩增出编码双加氧酶大亚基和小亚基的基因片段,序列分析表明与已知降解芘的分枝杆菌的双加氧酶基因具有高度同源性.

A bacterial strain Mll using phenanthrene, anthracene, fluorethene,pyrene as a sole carbon and energy sources was isolated from soils contaminated with polycyclic aromatic hydrocarbons. Strain Mll was identified as Mycobacterium sp. according to the results of morphology,physiology and the phylogenetical analyses of 16S rDNA sequence. The degradation rate of pyrene （at levels of 50 mg/L, 100 mg/L and 200 mg/L） by strain Mll was 76.9% ,91.8% and 79.23% within 16 d in broth assay. Mycobacterium sp. Mll showed a strong ability to grow from pH 5 to pH 9 in liquid minimal medium containing pyrene 100 mg/L. Mycobacterium sp. Mll possessed aromatic-ring dioxygenase genes, which are highly homologous to the known nidAB genes from pyrene-degrading Mycobacteria.