一株耐盐Cr(Ⅵ)还原菌的分离鉴定和还原特性研究

Isolation,identification and reduction characteristics of a salt-tolerant Cr(Ⅵ) reducing strain

为解决高无机盐废水中的铬(Chromium,Cr)的六价铬Cr(Ⅵ)污染问题,从高盐环境中分离得到一株Cr(Ⅵ)还原菌,命名为KL01,经分子鉴定为墓画大洋芽孢杆菌(Oceanobacillus picturae),通过对KL01的生理特征分析发现其为一株中度嗜盐菌.以SEM、TEM结合能谱对Cr(Ⅵ)胁迫下的菌体进行了检测,发现KL01对Cr仅有少量的胞内吸附,无胞外吸附,且高浓度的Cr(Ⅵ)可使菌体长度增加.通过KL01在不同环境条件还原Cr(Ⅵ)能力的影响研究,发现其在有氧条件下,30℃,pH 7.5,NaCl浓度6%时,具有较好的还原Cr(Ⅵ)的效果;当Cr(Ⅵ)浓度为20 mg/L时,对其的还原率可达96%以上.这表明KL01对高盐环境中的Cr(Ⅵ)具有良好的去除效果,可用于处理高盐含Cr(Ⅵ)废水.

In order to solve the problem of hexavalent chromium Cr(Ⅵ)pollution in high inorganic salt wastewater,a strain of Cr(Ⅵ)reducing bacteria,named KL01,was isolated from the hypersaline environment and molecularly identified as Oceanobacillus picturae.The physiological characteristics of KL01 revealed that it is a moderately halophilic strain.The cells under Cr(Ⅵ)stress were examined by SEM and TEM combined with EDS,and it was found that KL01 showed only a small amount of intracellular adsorption of chromium,but no extracellular adsorption and the high concentration of Cr(Ⅵ)caused an increase in the length of the bacteria.Single-factor experiments were conducted to investigate the ability of different environmental conditions on the reduction of Cr(Ⅵ)by KL01.It was found that KL01 had a better Cr(Ⅵ)reduction effect under aerobic conditions,30℃,pH 7.5 and 6%NaCl concentration,and the reduction rate for 20 mg/L Cr(Ⅵ)was above 96%.It was shown that KL01 has a good removal effect on Cr(Ⅵ)in hypersaline environment and can be used for the treatment of Cr(Ⅵ)in the hypersaline wastewater.