【摘要】 从湖北省武汉市长期施加硒肥的土壤中筛选到一株耐硒、镉和铬特性的菌株XY24，经形态学和分子生物学鉴定为巨大芽孢杆菌(Bacillus megaterium)。亚硒酸钠、氯化镉和铬酸钾耐受实验表明，XY24对亚硒酸钠、氯化镉和铬酸钾具有较好的耐受性，亚硒酸钠的耐受浓度为200mmol/L，氯化镉的耐受浓度为0.4 mmol/L，铬酸钾的耐受浓度为0.04 mmol/L。XY24抗氧化实验显示，其次级代谢产物在2.5 mg/mL浓度下ABTS自由基的清除率为(95.54±2.34)%,DPPH自由基清除率为(55.20±3.76)%。生长特性研究表明，XY24在温度为37℃、p H值为6、转速为180 r/min、接种量为1%时生长状态较好。产酶初筛显示，菌株XY24还具有产蛋白酶和淀粉酶的生物特性。文章从多方面对XY24环境生物修复潜力进行评价，为更好地利用微生物降低土壤中重金属和硒污染、清除环境持久性自由基及土壤改良等方面提供理论指导。更多还原

【Abstract】 In this laboratory, a strain XY24 with cadmium, chromium and selenium resistance was screened from the soil with long-term application of selenium fertilizer in Wuhan, Hubei Province. It was identified as Bacillus megaterium by morphology and molecular biology. The tolerance experiments of sodium selenite, cadmium chloride and potassium chromate showed that XY24 had good tolerance to sodium selenite, cadmium chloride and potassium chromate. The tolerance concentration of sodium selenite was 200 mmol/L, the tolerance concentration of cadmium chloride was 0.4 mmol/L, and the tolerance concentration of potassium chromate was 0.04 mmol/L. The antioxidant experiment of XY24showed that the scavenging rate of ABTS free radical was(95.54±2.34)% and the scavenging rate of DPPH free radical was(55.20±3.76)% at the concentration of 2.5 mg/mL. The growth characteristics of XY24 showed that the growth state was better when the temperature was 37 ℃, the pH was 6, the rotation speed was 180 r/min, and the inoculation amount was 1%. Preliminary screening of enzyme production showed that strain XY24 also had the biological characteristics of producing protease and amylase. In this paper, the potential of XY24 environmental bioremediation was evaluated in many aspects, which provided theoretical guidance for better utilization of microorganisms to reduce heavy metal and selenium pollution in soil, scavenging environmental persistent free radicals and soil improvement.更多还原