抗铅真菌的筛选、鉴定及其对Pb^2+的吸附特性

Isolation and Identification of Lead-resistant Fungus and Its Adsorption Characteristics to Pb^2+

【目的】本文从重金属污染土壤中分离出具有耐Pb活性的菌株,为土壤重金属生物修复提供参考。【方法】采用Pb^2+浓度梯度培养法驯化筛选得到耐Pb真菌1株(命名为PbW),对其进行18S rRNA测序并构建系统发育树,在不同培养条件下研究该菌株的生长特性,设置不同的Pb^2+浓度梯度研究菌株的最大抗性水平(MRL)、去除率及吸附效率。【结果】该菌株(PbW)为茎点霉属(Phoma sp.),最适生长的环境条件分别为:温度25℃,pH 7,时间4~5 d,对Pb^2+的最大耐受浓度可达6000 mg·L^-1。该菌株在Pb^2+浓度为2000 mg·L^-1时去除和吸附效果最好,吸附率可达56.28%,去除率可达到98.42%,吸附量为61.87 mg·L^-1。【结论】菌株(PbW)对土壤中的Pb^2+具有较好的吸附和去除效果,这在Pb污染土壤的微生物修复方面具有良好的应用前景。

【Objective】This paper aimed to isolate lead-resistant strains from heavy metal contaminated soil to provide a reference for soil heavy metal bioremediation.【Method】The lead-resistant strains were isolated from heavy metal-contaminated soils,and one lead-resistant fungus(named PbW)was domesticated by Pb^2+concentration gradient culture.Its 18S rRNA was sequenced,and phylogenetic tree was constructed.The maximum resistance level(MRL),removal rate and adsorption efficiency of the strain were studied by Pb^2+concentration gradient.【Result】The strain(PbW)was Phoma sp.The optimum environmental conditions were:temperature 25℃,pH 7,time 4-5 days,the maximum tolerated concentration of Pb^2+reached 6000 mg·L^-1.The strain had the best removal and adsorption effect when the concentration of Pb2+was 2000 mg·L^-1,the adsorption rate reached 56.28%,the removal rate reached 98.42%,and the adsorption a-mount was 61.87 mg·L^-1.【Conclusion】This study showed that the strain(PbW)had a good adsorption and removal effects on Pb^2+in soil,which could have a good application prospect in microbial remediation of lead-contaminated soil.