【摘要】 由于近年来工业的发展，环境重金属污染已成为亟待解决的问题，而生物法治理土壤砷污染目前已是该领域的研究热点.本研究旨在筛选出高耐砷促生菌株，并初步探究菌株对砷的去除能力.从实验室保藏及分离自铁尾矿土壤的菌株中筛选出对As³⁺和As⁵⁺均有高耐受活性的两株菌.其中LSM1可分别耐受3 200 mg·L^-1的As³⁺和5 500 mg·L^-1的As⁵⁺,LYT1可分别耐受3 200 mg·L^-1的As³⁺和6 000 mg·L^-1的As⁵⁺,两株菌分别被鉴定为萎缩芽孢杆菌（Bacillus atrophaeus）和鲍曼不动杆菌（Acinetobacterbaumannii）.进一步探究筛得菌株的促生作用，结果表明，LSM1具有产IAA能力，LYT1兼具解磷、固氮和产IAA能力.菌株的最适生长条件及复合菌剂的As⁵⁺去除能力研究结果表明，LSM1和LYT1的最适生长pH和温度均为pH=7,30℃,LSM1在As⁵⁺50 mg·L^-1、LYT1在As⁵⁺100 mg·L^-1下的生长情况最好.两株菌在培养48 h时对砷的去除率均大于24 h,两株菌在培养液As⁵⁺为50 mg·L^-1条件下对砷的去除率均大于100 mg·L^-1,研究表明，复合菌剂的砷去除率均大于单个菌株，复合菌剂在48 h、培养液As⁵⁺浓度为50 mg·L^-1时的砷去除率达到最大值，为67.40%.研究结果表明，两株菌对As³⁺和As⁵⁺均有高耐受性和去除能力，并具有促生作用，为后续开展植物-微生物联合修复砷污染土壤研究提供菌种资源和技术支撑.更多还原

【Abstract】 With the development of industry in recent years, environmental heavy metal pollution has become an urgent problem to be solved.The use of biological methods to control soil arsenic pollution has become a research hotspot in this field.This research aims to screen out high arsenic-tolerant growth-promoting strains, provide strain resources for soil bioremediation, and initially explore the strain’s ability to remove arsenic.Two strains with high tolerance to As³⁺ and As⁵⁺ were selected from the strains preserved in the laboratory and isolated from the soil of iron tailings.Among them, LSM1 can tolerate As³⁺ of 3 200 mg·L^-1 and As⁵⁺ of 5 500 mg·L^-1 respectively, and LYT1 can tolerate As³⁺ of 3 200 mg·L^-1 and As⁵⁺ of 6 000 mg·L^-1 respectively.The two strains were identified as Bacillus atrophaeus and Acinetobacterbaumannii.The growth-promoting effect of the two strains was studied, and the results showed that LSM1 has the ability to produce IAA,and LYT1 has both the ability to solubilize phosphorus, fix nitrogen and produce IAA.The optimal growth conditions of the strains and the As⁵⁺ removal ability of the compound inoculants showed that the optimal growth conditions of LSM1 were medium pH=7,temperature 30 ℃,medium As⁵⁺ 50 mg·L^-1,and the optimal growth conditions for LYT1 were medium pH=7,the temperature 30 ℃,and the culture medium As⁵⁺ 100 mg·L^-1.The removal rate of arsenic by the two strains is greater than 24 h when cultured for 48 h, and the removal rate of arsenic by the two strains is greater than 100 mg·L^-1 under the condition of 50 mg·L^-1 in the culture medium.The removal rate of arsenic was higher than that of a single strain, and the removal rate of arsenic reached the maximum value of 67.40% when the compound bacterial agent was 48 h and the concentration of As⁵⁺ in the culture solution was 50 mg·L^-1.The research results show that the two strains have high tolerance and removal ability to As³⁺ and As⁵⁺,and have obvious growth-promoting effects on plants, which provide bacteria resources and technologies for further research on the joint remediation of arsenic contaminated soil by plants and microorganisms.更多还原