Electron Transfer Pathways and Vanadium Isotope Fractionation During Microbially Mediated Vanadate Reduction  

作　　者：Wenyue Yan Baogang Zhang Yi’na Li Jianping Lu Yangmei Fei Shungui Zhou Hailiang Dong Fang Huang 

机构地区：[1]School of Water Resources and Environment,Minisitry of Education(MOE)Key Laboratory of Groundwater Circulation and Environmental Evolution,China University of Geosciences Beijing,Beijing 100083,China [2]Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation,College of Resources and Environment,Fujian Agriculture and Forestry University,Fuzhou 350002,China [3]Center for Geomicrobiology and Biogeochemistry Research,State Key Laboratory of Biogeology and Environmental Geology,School of Earth Sciences and Resources,China University of Geosciences Beijing,Beijing 100083,China [4]Chinese Academy of Sciences(CAS)Key Laboratory of Crust-Mantle Materials and Environments,School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,China

出　　处：《Engineering》2025年第3期257-266,共10页工程(英文)

基　　金：supported by the National Natural Science Foundation of China(U21A2033);the Fundamental Research Funds for the Central Universities(2652022103).

摘　　要：Microbial vanadate(V(V))reduction is a key process for environmental geochemistry and detoxification of vanadium(V).However,the electron transfer pathways and V isotope fractionation involved in this process are not yet fully understood.In this study,the V(V)reduction mechanisms with concomitant V isotope fractionation by the Gram-positive bacterium Bacillus subtilis(B.subtilis)and the Gramnegative bacterium Thauera humireducens(T.humireducens)were investigated.Both strains could effectively reduce V(V),removing(90.5%±1.6%)and(93.0%±1.8%)of V(V)respectively from an initial concentration of 50 mg L^(-1) during a 10-day incubation period.V(V)was bioreduced to insoluble vanadium(IV),which was distributed both inside and outside the cells.Electron transfer via cytochrome C,nicotinamide adenine dinucleotide,and glutathione played critical roles in V(V)reduction.Metabolomic analysis showed that differentially enriched metabolites(quinone,biotin,and riboflavin)mediated electron transfer in both strains.The aqueous V in the remaining solution became isotopically heavier as V(V)bioreduction proceeded.The obtained V isotope composition dynamics followed a Rayleigh fractionation model,and the isotope enrichment factor(e)was(–0.54‰±0.04‰)for B.subtilis and(–0.32‰±0.03‰)for T.humireducens,with an insignificant difference.This study provides molecular insights into electron transfer for V(V)bioreduction and reveals V isotope fractionation during this bioprocess,which is helpful for understanding V biogeochemistry and developing novel strategies for V remediation.

关 键 词：VANADATE BIOREDUCTION Vanadium isotope fractionation Electron transfer 

分 类 号：X172[环境科学与工程—环境科学]