南海深海沉积物烷烃降解菌的富集分离与多样性初步分析

The diversity of alkane degrading bacteria in the enrichments with deep sea sediment of the South China Sea

通过培养和非培养2种手段研究了南海沉积物中石油降解菌的多样性。通过烷烃富集培养,从2个站点不同深度的南海沉积物样品中富集筛选出48株深海细菌,其中27株对十六烷有降解能力。表面张力测定结果表明,4株降解菌同时具有较强的表面活性剂产生能力,2株Dietzia maris菌能使水的表面张力降至33mN/m左右,这是该种微生物产表面活性剂的首次报道。通过变性梯度凝胶电泳(DGGE)分析显示,南海沉积物富集物中的烷烃降解菌优势菌是芽孢杆菌,而且有多种。其中,Bacillus aquimaris在两个站点的7个样品的富集物中都是优势菌。此外,Sporosarcina,Halomona以及Brevibacterium属的细菌在不同样品中也表现为除Bacillus之外的优势菌。

Deep sea sediment samples of the South Sea of China were used for isolation and biodiversity examination of hydrocarbon degrading bacterium. 48 isolates were obtained from the enrichments with hexadecane as the sole carbon sources. Among them,27 isolates were capable of degrading alkane; and 4 could produce biosurfactant significantly as determined by the surface tension measurement. 2 isolates belonging to Dietzia maris lowered water surface tension to 33 mN/m. This is the first report about D. maris in biosurfactant production. The results of polymerase chain reaction （PCR） followed by Denaturing Gradient Gel Electrophoresis （DGGE） and DNA sequencing suggested that Bacillus was the dominant member in the hexadecane enriched communities. Isolates of Bacillus aquimaris were demonstrated to be the most predominant degraders in all 7 samples at 2 sampling sites. In addition, Sporosarcina, Halomonas and Brevibacterium were also found as one of the dominant members in some samples. Therefore,species of Bacillus might play an important role in alkane degradation in the sediments of the sampling sites.