一株高耐镉硫酸盐还原菌的分离及脱硫性能研究

本研究从镉污染稻田水稻根际土壤中分离、纯化出一株硫酸盐还原菌SRB1-1,并对该菌株的生理生态特征、镉和盐耐受性、16S rDNA、脱硫性能及影响因子进行了系列分析。结果表明,该菌为革兰氏阴性菌,菌体弧状,对镉离子的耐受浓度可达200 mg/L,在2%的氯化钠浓度下仍可生长。对其16S rDNA的序列分析表明该菌株属于脱硫弧菌属(Desulfovibrio)。单因子实验考察温度、pH及SO_4~(2-)浓度对该菌脱硫效率的影响,正交实验确定了该菌最佳脱硫工艺条件及影响因子顺序。结果表明最佳脱硫工艺条件为pH 7.5、温度40℃、SO_4~(2-)浓度为1 000 mg/L、培养时间56 h。

Separation and Desulfurization Characteristics Research of Sulfate Reducing Bacteria-Tolerant to Cadmium

A sulfate reducing bacterial strain named SRB1-1 was isolated and purified from the rice rhizosphere soil pol-luted by cadmium.The physiological characteristics,the tolerance to cadmium and salt,16S rDNA,desulfurization characteristics and its influence factors of SRB1-1 were studied.The results showed that SRB1-1 was a Gram-negative and arc-shaped strain,and could grow under the concentration of 200 mg/L cadmium or 2% salt.Analysis of 16S rDNA sequence of SRB1-1 showed it belonged to Desulfovibrio.The effects of temperature,pH and concentration of SO4 2-on desulfurized efficiency of SRB1-1 were studied,and the desulfurized condition was optimized by a L9 (3 4 )orthogonal de-sign.Results showed that the optimized conditions were pH 7.5,40 ℃,1 000 mg/L SO4 2-,and 56 h.