海洋沉积物中六溴环十二烷的微生物降解特性及降解菌的分离鉴定

Characteristics of hexabromocyclododecane (HBCDs) degradation by marine sediment microbes and the isolation and identiediment of degradation bacteria

为了解六溴环十二烷(HBCDs)在海洋沉积物中的好氧微生物降解特性,在以HBCDs为唯一碳源的无机培养基中添加海洋沉积物悬浮液,利用HPLC-MS/MS测定HBCDs降解率,并驯化分离得到HBCDs降解菌株,进行菌种鉴定.结果显示:海洋沉积物好氧微生物对HBCDs的降解半衰期为38-61 d;在120 d中HBCDs共降解了72%;从海洋沉积物中富集、分离得到5株能够以HBCDs为唯一碳源的降解菌株,分别命名为CTF711-A、CTF711-C、CTF711-D、CTF711-E和CTF711-X,结合形态学观察、生理生化试验和16S r DNA序列分析,将其依次鉴别为假单胞菌属、红球菌属、不动杆菌属、微杆菌属和盐单胞菌属,除假单胞菌属外,其余菌株对HBCDs的降解能力还尚未见报道.同时将这5株菌分别培养与混合培养,混合菌株对HBCDs降解率最高.本研究报道了5株不同属的HBCDs好氧降解菌株,且混合菌株对HBCDs降解效果较好,结果可为HBCDs的生物修复提供理论和应用依据.

In order to study the characteristics of aerobic microbial degradation of hexabromocyclododecane （HBCDs） in marine sediments, the degradation rate of HBCDs was investigated using HPLC-MS/MS. The suspension of marine sediment was added to inorganic mediums with HBCDs as the sole carbon source. The HBCDs degradation strains were isolated after domestication, then molecular identification was performed. The results showed the half-life of HBCDs degradation by aerobic microorganisms in marine sediment as 31-62 days. Five strains of bacteria were isolated and named CTF711-A, CTF711-C, CTF711-D, CTF711-E, and CTF711-X, respectively. Based on morphology, biochemical tests and 16S rDNA sequence analysis, the five strains were classified as Pseudomonas, Rhodococcus, Acinetobacter, Microbacterium and Halomonas. The degrading rate of mixed bacteria strains was higher than that of single strains. The results provided supporting data for HBCDs bioremediation of contaminated environment.