珠江沉积物中硫酸盐还原菌的分离筛选及其性质鉴定

Isolation and Identification of Sulfate-reducing Bacteria from Pearl River Sediment

摘要:

由于能够形成可以与重金属反应形成沉淀的硫化物，硫酸盐还原菌对于改善水体质量、确保食品和饮水安全上有着重要意义。从珠江沉积物中分离出一株硫酸盐还原菌SCUT-3，该细菌呈杆状、革兰氏染色为阴性，能够以乳酸、乙酸、丙酸作为唯一碳源，以硫酸盐作为电子受体进行生长，不能以葡萄糖、乙醇等作为唯一碳源，硫代硫酸盐和亚硫酸盐为电子受体进行生长。对该细菌的16S rRNA基因和aprA基因序列进行分析，发现其16S rRNA基因与Desulfovibrio acrylicus的16S rRNA基因的一致性最高，达到87%，其aprA基因与Desulfovibrio vulgaris str. Hildenborough的aprA基因一致性最高（通过blastx比对），达到90%。因此可判断其属于脱硫弧菌属（Desulfovibrio），但两基因的序列与已知序列同源性均不超过91%，判断该细菌属于脱硫弧菌属中的一个新种。

Abstract:

Sulfate-reducing bacteria (SRB) have great significance in improving the quality of water resources and ensuring the safety of food and drinking water , due to their ability in producing sulfides which could precipitate heavy metal ions in the form of metal sulfides. SCUT-3, a rod shaped gram negative sulfate reducing bacterium, was isolated from the Pearl River sediment sample. SCUT-3 can utilize lactate, acetate and propionate as sole carbon source and sulfate as the terminal electron acceptor. Glucose and ethanol could not be utilized as carbon sources. Thiosulfate and sulfite could not be utilized as terminal electron acceptor. Phylogenetic analysis based on aprA and 16S rRNA genes slightly differed between each other. SCUT-3 showed the highest similarity on the 16S rRNA genes (87%) to Desulfovibrio acrylicus, andthe highest similarity on the aprA genes (90%, by blastx) to Desulfovibrio vulgaris str. Hildenborough, indicating that SCUT-3 belonged to the genus Desulfovibrio. But the relative low similarity (91% utmost) indicates that the new isolated strain might belong to a new species of this genus.