稻田土壤微生物多样性对汞甲基化的影响  

Effects of microbial diversity on mercury methylation in paddy soils

作　　者：张谦朔 郝正东 张坤 蒲强 孟博[1] 冯新斌[1,2] ZHANG Qian-shuo;HAO Zheng-dong;ZHANG Kun;PU Qiang;MENG Bo;FENG Xin-bin(State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院地球化学研究所,环境地球化学国家重点实验室,贵阳550081 [2]中国科学院大学,北京100049

出　　处：《矿物岩石地球化学通报》2024年第5期1009-1017,共9页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：国家自然科学基金资助项目(41931297,42207164);贵州省科学技术基金资助项目(黔科合基础-ZK[2022]一般566)。

摘　　要：稻田土壤中的无机汞在微生物作用下可转化为高神经毒性的甲基汞,被富集至稻米中,从而威胁人体健康。探讨稻田土壤微生物多样性的改变对汞甲基化过程的影响,可拓宽我们对稻田生态系统微生物汞甲基化的认识。本研究利用梯度稀释法改变万山汞矿区稻田土壤微生物多样性,探讨微生物多样性的改变对稻田土壤汞甲基化的影响。结果表明,微生物多样性减少会降低甲基汞的生成潜力,可能是汞甲基化微生物在汞胁迫下适应性代价高导致其相对丰度降低,而潜在的去甲基化微生物因竞争力优势使其相对丰度升高造成的。本研究提供了微生物多样性影响汞甲基化过程的实验证据,强调了微生物群落定植对汞甲基化的重要性。Inorganic mercury(Hg)in paddy soil can be converted into highly neurotoxic methylmercury under the action of microorganisms.Methylmercury is often enriched in rice,posing a potential threat to human health.Due to the impact of climate change and human activities,the decline in soil microbial diversity has become an indisputable fact.Exploring how changes in paddy soil microbial diversity affect Hg methylation can broaden our understanding of biological Hg methylation in rice ecosystem.In this study,the gradient dilution method was used to change the microbial diversity of paddy soil in Wanshan Hg mining area,and explored the impact of microbial diversity change on Hg methylation in paddy soil.The results showed that reduced microbial diversity reduces methylmercury generation potential,which may be attributed to a decrease in the relative abundance of Hg-methylating microorganisms due to the high cost of adaptation to Hg stress and an increase in the relative abundance of potential demethylating microorganisms due to their competitive advantage.This study provides experimental evidence that microbial diversity affects Hg methylation and highlights the importance of microbial community colonization on Hg methylation.

关 键 词：水稻土 多样性降低 汞甲基化 

分 类 号：P456.7[天文地球—大气科学及气象学]