The effect of hydrostatic pressure on the nitrogen removal potential at the sediment water interface of reservoirs
The effects of different hydrostatic conditions(atmospheric pressure,0.2MPa,0.5MPa and 0.7MPa)on microbial community structure,nitrogen cycling function genes and metabolic pathways at the sediment-water interface of reservoir were studied through microcosmic simulation experiments and metagenomics.The results showed that the number of microbial species involved in nitrogen cycling increased first to 1227 and then decreased to 1199 with the increase of hydrostatic pressure.The relative abundances of archaea and fungi increased by 0.002％and 0.0006％with the increase of hydrostatic pressure,while the proportion of bacteria decreased.High hydrostatic pressure fostered closer ecological network connections,intricate interspecific interactions,and enhanced system stability compared to low pressure.Furthermore,increased hydrostatic pressure facilitated denitrification and repressed dissimilatory nitrate reduction by augmenting the abundance of functional genes such as nxrB and narH,alongside the participating microorganism abundance.Moreover,piezophilic taxa(e.g.,Proteobacteria,Chloroflexi,Bacteroidetes)and genes(e.g.,ompH,asd)were identified among nitrogen-cycling microorganisms,with a predominant presence in Proteobacteria.Their abundance initially grew and then declined with rising pressure.Hydrostatic pressure can improve the nitrogen removal potential of reservoir sediments by altering the microbial population structure,related functional gene abundance,and metabolic pathways involved in the nitrogen cycle at the sediment-water interface,thereby mitigating reservoir eutrophication.
metagenomicshydrostatic pressuremicrobial community structurenitrogen cyclereservoir sediment
万方数据
维普
