Nitrogen-cycling processes under long-term compound heavy metal(loids)pressure around a gold mine:Stimulation of nitrite reduction
简介：Mining and tailings deposition can cause serious heavy metal(loids)pollution to the sur-rounding soil environment.Soil microorganisms adapt their metabolism to such condi-tions,driving alterations in soil function.This study aims to elucidate the response patterns of nitrogen-cycling microorganisms under long-term heavy metal(loids)exposure.The re-sults showed that the diversity and abundance of nitrogen-cycling microorganisms showed negative feedback to heavy metal(loids)concentrations.Denitrifying microorganisms were shown to be the dominant microorganisms with over 60％of relative abundance and a com-plex community structure including 27 phyla.Further,the key bacterial species in the den-itrification process were calculated using a random forest model,where the top three key species(Pseudomonas stutzei,Sphingobium japonicum and Leifsonia rubra)were found to play a prominent role in nitrite reduction.Functional gene analysis and qPCR revealed that nirK,which is involved in nitrite reduction,significantly accumulated in the most metal-rich soil with the increase of absolute abundance of 63.86％.The experimental results confirmed that the activity of nitrite reductase(Nir)encoded by nirK in the soil was increased at high con-centrations of heavy metal(loids).Partial least squares-path model identified three poten-tial modes of nitrite reduction processes being stimulated by heavy metal(loids),the most prominent of which contributed to enhanced nirK abundance and soil Nir activity through positive stimulation of key species.The results provide new insights and preliminary evi-dence on the stimulation of nitrite reduction processes by heavy metal(loids).展开
学者：XuesongHUXiaoxiaLiuShuoZhangCaihongYu
关键词：N cycleNitrite reductionNitrite reductasemetagenomeKey species
在线出版日期：2025-01-22 （网站首发日期）
