一株耐酸SRB的分离及其脱硫除镉性能

为减轻酸性矿山废水引起的环境污染，为矿山废水处理提供潜在的菌种资源，从土壤中分离出一株耐酸的硫酸盐还原菌SRB1并探讨了该菌株的还原硫酸盐和除镉特性.结果表明该菌株具有较强的脱硫除镉能力，其最低耐受pH值，最适温度，最大耐Cd²⁺浓度分别为3.7，35℃和40mg/L.在COD/SO₄^2-≥2，Cd²⁺浓度≤30mg/L条件下，除镉率可达99%以上.在高浓度Cd²⁺和SO₄^2-的体系中，该菌对Cd²⁺有较强的吸附作用，能将Cd²⁺从50mg/L降至15.5mg/L，吸附率达58%，采用二次培养能将SO₄^2-从1.5g/L降至0.04g/L，脱硫率达97.3%，Cd²⁺浓度几乎降为零.TEM、FTIR、SEM表征显示，在镉胁迫下，该菌株的细胞形态发生改变，吸附前后，红外吸收峰改变明显，沉淀颗粒含有结晶CdS.

Isolation and characterization of an acid-resistance SRB strain with the efficient of desulfurization and cadmium-removal

In order to reduce the environmental pollution caused by acid mine drainage,and provide potential microbiology resources for mine drainage treatment, an acid tolerant sulfate educing bacteria strain SRB1was isolated from soil,and its characterization of reducing sulfate and cadmium removal were discussed. The results showed that the strain had high desulfurization and cadmium removal potential, and its lowest tolerant pH value, optimum temperature and maximum Cd²⁺ concentration were 3.7, 35℃ and 40mg/L, respectively. Under the condition of COD/SO₄^2- ≥ 2, Cd²⁺ concentration ≤ 30mg/L, the cadmium removal rate can reach more than 99%. In the high concentration of Cd²⁺ and SO₄^2- system, the strain had strong adsorption on Cd²⁺, Cd²⁺ can be decreased from 50mg/L to 15.5mg/L, the adsorption rate reached 58%. Using secondary culturing SO₄^2- might be reduced from 1.5g/L to 0.04g/L, the desulfurization rate reached 97.3%, and the Cd²⁺ concentration almost decreased to 0. TEM, FTIR, SEM characterization showed that the cell morphology of the strain was changed under cadmium stress, the infrared absorption peak was changed obviously before and after adsorption, and the precipitated particles contained crystalline CdS.