稳定混合菌协同降解咔唑研究

Synergetic Degradation of Carbazole by a Stable Microbial Consortium

以咔唑(Carbazole,CAR)作为唯一碳源和氮源,从某炼油厂废水中筛选获得稳定的咔唑降解混合菌株.对该混合菌株进行分离和纯化,获得两株细菌,经生物化学和分子进化特征分析后,初步鉴定为Chryseobacterium sp.NCY和Achromobacter sp.NCW.扫描电镜显示,两株菌在含咔唑的无机盐培养基和肉膏培养基上生长时,细胞形态发生显著的变化.这两株细菌形成的稳定复合体在24h内对咔唑(500mgL-1)的降解率为80%,64h内降解率可达到99%以上,并释放出氨氮22.69mgL-1.纯化后的两株细菌单独以咔唑为唯一碳源和氮源,均不能生长,推测两株菌通过协同代谢作用降解咔唑.

A stable microbial consortium mainly consisting of two kinds of bacteria, was screened with a selective medium of earbazole from refinery wastewater sample. The microbial consortium could grow on the medium with carbazole （CRA） as sole carbon source, nitrogen source and energy, and liberated ammonia from excess nitrogen. Based on the 16S rDNA sequences analysis, the bacteria were identified as Chryseobacterium sp. NCY and Achromobacter sp. NCW. Scanning electron microscope micrograph showed the cells of the bacteria grown on different mediums varied morphologically. The stable microbial consortium could degrade 80% of 500 mg L^-1 carbazole and released 22.69 mg L^-1 NH4^＋ in 24 h. However, the pure culture of two strains isolated from nutrient agar plate could not degrade carbazole after some experiments. It is suggested that the stable microbial consortium formed by the two bacteria could degrade carbazole through synergetic metabolism.