Di Zhao, Chaoyang Li, Mengxi Zheng, Yunlin Zhao, Zhenggang Xu, Guiyan Yang
Hunan Research Center of Engineering Technology for Utilization of Environmental and Resources Plant, Central South University of Forestry and Technology, Changsha, China.
Central South Inventory and Planning Institute of National Forestry and Grassland Administration, Changsha, China.
Front Microbiol. 2022 Jan 27;12:816312. doi: 10.3389/fmicb.2021.816312. eCollection 2021.
Soil heavy metal pollution is a common problem in mining areas. The soil of the Xikuangshan located in Lengshuijiang, Hunan Province, China contains various excessive heavy metals, especially antimony and cadmium. Previous studies have shown that heavy metal-tolerant microorganisms screened from mining areas have the potential to adsorb heavy metals. In this study, we screened out a cadmium and antimony tolerant fungus named XK8 from the slags collected from the Xikuangshan. Then, we explored the single and binary biosorption characteristics of Cd(II) and Sb(III) on it. In our results, the fungus XK8 was identified as XK8 by ITS sequencing analysis. Under the optimal conditions, in binary biosorption of the XK8, the main effect of the initial cadmium concentration on the cadmium removal rate of XK8 is negative, while the main effect of the initial antimony concentration, biosorption time, and initial pH on the cadmium removal rate of XK8 is positive. The initial pH has the greatest impact on the biosorption of cadmium on XK8, followed by the biosorption time; moreover, the effects of both are stronger than the coexisting ions. SAS analysis shows that under the optimal conditions, the theoretical maximum cadmium removal rate of XK8 is 100%, and the actual removal rate is 67.57%. Compared to the single biosorption with binary biosorption, the maximum biosorption capacity of XK8 for cadmium in the composite biosorption system increased to 23.6 mg g. It shows that under the background of high antimony, Sb(III) has a promoting effect on the biosorption of Cd(II) on XK8. In summary, a cadmium and antimony tolerant fungus with strong cadmium biosorption ability under the background of high antimony was screened out. It provides a potential microbial material for the bioremediation of heavy metal pollution.
土壤重金属污染是矿区的常见问题。位于中国湖南省冷水江市的锡矿山土壤含有多种过量重金属，尤其是锑和镉。先前的研究表明，从矿区筛选出的耐重金属微生物具有吸附重金属的潜力。在本研究中，我们从锡矿山采集的矿渣中筛选出一种耐镉和锑的真菌，命名为XK8。然后，我们探究了Cd(II)和Sb(III)在其上的单吸附和双吸附特性。在我们的结果中，通过ITS测序分析将真菌XK8鉴定为XK8。在最佳条件下，XK8的双吸附中，初始镉浓度对XK8镉去除率的主要影响为负，而初始锑浓度、吸附时间和初始pH对XK8镉去除率的主要影响为正。初始pH对XK8吸附镉的影响最大，其次是吸附时间；此外，两者的影响都强于共存离子。SAS分析表明，在最佳条件下，XK8的理论最大镉去除率为100%，实际去除率为67.57%。与单吸附相比，复合吸附体系中XK8对镉的最大吸附容量增加到23.6 mg/g。这表明在高锑背景下，Sb(III)对XK8吸附Cd(II)有促进作用。综上所述，筛选出一种在高锑背景下具有较强镉吸附能力的耐镉和锑真菌。它为重金属污染的生物修复提供了一种潜在的微生物材料。
