一株硫酸盐还原菌的分离鉴定及生物学特性研究

从处理硫酸盐废水厌氧折流板反应器（Anaerobic battqe reactor，ABR）的污泥中分离到1株硫酸盐还原菌，对该菌株进行了形态、生理生化特性方面的研究，并对16S rDNA序列进行了分析。该菌株为杆状或弧状，大小为（0．5～0．7）μm×（1．4～1．9）μm，革兰染色阴性，芽胞染色阴性，能运动，具有硫酸盐还原功能。菌株最适生长pH为7．0～8．0，喜中性偏碱环境；初始SO4^2-]为2000mg／L，OD600nm。值为1．206，SO4^2-去除率达到71％；该菌株能分别利用乳酸、丙酮酸、丁酸、乙酸、乙醇、甲醇、葡萄糖作为电子供体，进行硫酸盐异化还原，乳酸最有利于该菌SO4^2-的去除，SO4^2-去除率为91．4％，其次为丙酮酸，达到51．2％。基于16SrDNA序列同源性构建了系统发育树，结果表明此株菌是属于脱硫弧菌属（Desulfovibrio）的硫酸盐还原菌，与Desulfovibrio具有96．0％的序列相似性。

Identification and Characterisation of a Sulfate-Reducing Bacterium

A strain of sulfate-reducing bacterium was isolated from the sewage of an anaerobic baffle reactor (ABR). The morphological and biochemical characteristics as well as 16S rDNA sequence of the strain was studied. The cells are vibrioid-shaped or rod shape with the size of (0.5 ～ 0.7) μm × (1.4 ～ 1.9) μm. The strain is gram negative, motile and doesn' t form spore. The best pH value for growth is 7.0 -8.0. When the initial SO_4~(2-)]is 2 000 mg/L, the highest OD_(600nm) is 1. 206 and the SO_4~(2-) removal efficiency is up to 71%. The strain can use lactic acid, pyruvatic acid, butyric acid, acetic acid, ethanol, methanol and glucose as electron donor respectively. Lactic acid is the most suitable electron donor to reduce SO_4~(2-) , the SO_4~(2-) removal efficiency is up to 91.4% when lactic acid is the sole car-bon source. The results of 16S rRNA sequence and phylogenetic analysis show that the strain is the closest relative to Desulfovibrio sp. With 96.0% sequence similarity.