一株硫酸盐还原菌DSRBa的分离鉴定及特性分析

从内循环厌氧反应器颗粒污泥中分离、纯化得到一株硫酸盐还原菌命名为DSRBa,经形态和基于16SrDNA序列分析,该菌株归属于脱硫弧菌属（Desulfovibrio）。分别以甲酸钠、乙醇、乳酸钠、葡萄糖等为碳源,以硫酸盐、硫代硫酸盐、亚硫酸盐、单质硫为硫源,研究了不同温度、pH及不同硫酸根浓度对该菌株的影响。结果表明,菌株最适宜生长温度为30～35℃,最佳生长pH为7.0,无需绝对严格厌氧,当溶液中氧化还原电位（ORP）≤-40mV时,该菌株能较好生长,且生长4d后使溶液内氧化还原电位值达到-380mV,随后溶液内氧化还原电位基本保持不变。当系统内乳酸钠和酵母提取物浓度分别为3.5g·L-1和1g·L-1时,硫酸根浓度在1～4.5g·L-1范围对菌株生长无明显影响,且当SO24-浓度≤3g·L-1时,菌株生长4d对硫酸根的去除率达到90%以上。

Isolation and Identification of a Sulfate-reducing Bacteria DSRBa and Its Characterization

A sulfate-reducing bacteria named DSRBa was isolated from the granular sludge in a internal cycle（IC） anaerobic reactor.It was identified as Desulfovibrio based on the phenotypic-characteristics and the analysis of the sequence of 16S rDNA.Strain DSRBa could use sodium formate,ethanol,sodium lactate and glucose as carbon source and use sulfate,thiosulfate,sulfite and sulfur as sulfur sources,respectively.The influences of temperature,pH value,various sulfate concentration on its living activity were studied.The results showed that the optimum growth temperature and pH values for strain DSRBa were 30～35 ℃ and 7.0,respectively.Strain DSRBa could grow well when the initial oxidation-reduction potential（ORP） in solution was below-40 mV,and the ORP could reach to-380 mV for 4 d incubation,while further increase of incubation time did not have significant effect on ORP.When the concentrations of lactate and yeast in the incubation medium were 3.5 g·L-1 and 1 g·L-1,respectively,the growth of strain DSRBa hadn＇t been significantly restrained when the concentrations of sulfate were between 1～4.5 g·L-1.The removal rate of SO2-4 was above 90% in 4 d when its concentration was below 3 g·L-1.