中文摘要：

目的对六价铬[Cr（VI）]还原菌Cr4-1进行鉴定,并给出细菌生长和Cr（VI）还原的较好条件。方法采用生理生化法和16s r DNA测序法,对细菌Cr4-1进行鉴定,并分别研究温度、p H、初始Cr（VI）浓度和摇床转速对细菌生长和Cr（VI）还原效果的影响,用质量平衡法分析还原反应终产物。结果从驯化后的活性污泥中筛选的Cr（VI）还原菌Cr4-1,经鉴定为蜡样芽孢杆菌。细菌生长的较好条件为：25℃,p H 7-8,摇床转速200 r/min;还原Cr（VI）的适宜温度为35℃,p H8-9。Cr（VI）初始浓度从20 mg/L增加至60 mg/L,还原效果呈下降趋势。在较好的还原条件下,Cr（VI）初始浓度为30 mg/L时,9 h的还原率可达100%,还原反应终产物为可溶性三价铬。结论细菌Cr4-1为高效Cr（VI）还原菌,还原终产物为可溶性三价铬。

英文摘要：

Objective To identify the hexavalent chromium reduction Cr4-1,and to study the better conditions of the bacterial growth and its Cr（ VI） reduction. Methods The physiological and biochemical methods and 16 s r DNA sequencing were used for identification of bacteria Cr4-1. The influence of temperature, p H, initial Cr（ VI）concentration and shaking speed on bacterial growth and Cr（ VI） reduction were studied.Mass balance analysis was used to analyze the end products of the reduction reaction.Results A Cr（ VI） reducing bacteria Cr4-1,screened from acclimated activated sludge,was identified as Bacillus cereus. The appropriate conditions of bacterial growth was 25 ℃,p H 7 to 8,shaking speed 150 r / min,while the suitable conditions for Cr（ VI） reduction was 35 ℃,p H 8 to 9. When the initial Cr（ VI） concentration increased from 20 mg / L to60 mg / L,the reduction rate decreased gradually. Under the suitable reducing conditions,when the initial concentration of Cr（ VI） was 30 mg / L,the reduction rate could up to100% in 9 h. The end product was soluble trivalent chromium. Conclusion Strain Cr4-1 had a good effect on Cr（ VI） reduction and the final product was soluble trivalent chromium.