中文摘要：

在1%接种量、初始铬（VI）浓度50 mg L^-1、pH 7、30℃及180 r/min条件下,从源自水样、土壤、植物、动物粪便、食品、昆虫及饲料的76个苏云金芽胞杆菌（Bacillus thuringiensis,简称Bt）菌株中筛选出2株具有高效铬（VI）还原能力的菌株BRC-HZM7和BRC-XQ15,在24 h之内可使50 mg L^-1铬（VI）低于0.5 mg L^-1,达到我国铬（VI）废水排放标准.另有34株菌株最少只需36～72 h（36 h时6株菌株、48 h时4株菌株、60 h时13株菌株、72 h时11株菌株）就可使50 mg L^-1铬（VI）达到我国铬（VI）废水排放标准.Bt具有对环境和人安全的优点,在快速净化含铬（VI）废水方面具有广阔的应用前景.

英文摘要：

Microbial treatment of industry wastewater containing chromium（VI） is a kind of solutions with low investment and without secondary pollutants.76 Bacillus thuringiensis（Bt） strains,isolated from water,soils,plants,animal feces,foods,insects and fodder,were screened for their chromium-reduction capacity under the condition of 1% inoculum concentration,50 mg L-1 initial chromium（VI）,pH 7,30 ℃ and 180 r/min.The results showed that Bt strains BRC-HZM7 and BRC-XQ15 could reduce chromium（VI） from 50 mg L-1 to 〈0.5 mg L^-1 in 24 h,which reached Chinese standards for wastewater emission.In addition,the least time,needed for reducing 50 mg L-1 Cr（VI） to a certain concentration satisfying the Chinese standards for wastewater emission by 6,4,13 and 11 Bt strains,was 36 h,48 h,60 h and 72 h,respectively.Bt is safe to environment and human and can be widely used in the treatment of wastewater containing chromium（VI） in the future.