Spatial Pattern of Bacterial Community Diversity Formed in Different Groundwater Field Corresponding to Electron Donors and Acceptors Distributions at a Petroleum-Contaminated Site

Abstract

Abstract:The benefits of an electron-transfer mechanism for petroleum biodegrading have been widely acknowledged, but few have studied the spatial pattern of microbial community diversity in groundwater fields, and few discuss the bacterial community's diversity in relation to electron donors-acceptors distribution, which is largely determined by groundwater flow. Eleven samples in different groundwater fields are collected at a petroleum-contaminated site, and the microbial communities are investigated using 16S rRNA gene sequences with multivariate statistics. These are mainly linked to the chemical composition analysis of electron donor indexes COD, BTEX and electron acceptor indexes DO, NO 3 − , Fe 2+ , Mn 2+ , and SO 4 2− , HCO 3 − . The spatial pattern of the bacterial community's diversity is characterized and the effect of the electron redox reaction on bacterial community formation in different groundwater field zones is elucidated. It is found that a considerable percentage (>65%) of the bacterial communities related to petroleum degrading suggest that petroleum biodegrading is occurring in groundwater. The communities are subject to the redox reaction in different groundwater field zones: The side plume zone and the upstream of the source zone are under aerobic redox or denitrification redox, and the corresponding bacteria are Rhodoferax, Novosphingobium, Hydrogenophaga, and Comamonas; the source zone and downstream of the source zone are under Fe 3+ , Mn 4+ , and SO 4 2− reduction redox, and the corresponding bacteria are Rhodoferax, Treponema, Desulfosporosinus, Hydrogenophaga, and Acidovorax. These results imply that groundwater flow plays a definitive role in the bacterial community's diversity spatial pattern formation by influencing the distribution of electron donor and acceptor.

The Spatial Distribution of the Microbial Community in a Contaminated Aquitard below an Industrial Zone

“…However, as in our study, the relationship between contaminates load (uranium) and functional genes richness was insignificant. In another study however, diversity in groundwater polluted with hydrocarbons in China, was lower than the downstream groundwater, likely due to the dominance of degrading bacteria [48].…”

Response of soil bacterial community and geochemical parameters to cyclic groundwater‐level oscillations in laboratory columns

“…The number of OTUs unique to RIC_S (713) was much higher than those in QSC_S and NFC_S (309 and 292). Other researchers have demonstrated that soil bacterial community diversity can gradually decrease with significant removal of soil organic C by leaching, dissolution, and aerobic transformation (Ning et al., 2018). This could explain the diversity differences between the vadose zone communities, but not the similar diversity in the oscillated zone communities or that the highest diversity in the saturated zone was exhibited by RIC.…”

Groundwater Contamination, Subsurface Processes, and Remediation Methods: Overview of the Special Issue of Water on Groundwater Contamination and Remediation

“…Most of the studies considered anthropogenic sources, with Beretta et al [7] and Haluska et al [6] addressing the industrial additive and known carcinogen hexavalent chromium, Plymale et al [8] focusing on the toxic salt ferrocyanide, Haluska et al [6] measuring the organic contaminants 1,4-dioxane and hexahydro-1,3,5-trinitro-s-triazine (RDX), Prieto-Amparán et al [9] studying sewage effluent, and Wells et al [10] tracking the fertilizer-derived anion nitrate. As a particular subset of anthropogenic contaminants, two studies discuss emerging contaminants, particularly related to hydrocarbon resources, as Hu et al [11] study oil shale development, while Ning et al [12] focus on petroleum contamination.…”

“…In parallel, Hu et al [11] discuss the potential impacts from emerging contaminants related to oil shale development. Three studies explore the central role of biology in groundwater remediation, reflecting our new understanding of subsurface processes through the interdisciplinary lens of biogeochemistry: Ning et al [12] study the spatial pattern of bacterial communities at a petroleum-contaminated site; Plymale et al [8] study bacterial communities at a nuclear waste-contaminated site; and Moradi et al [14] contribute a model describing thermally-enhanced bioremediation. Taken together, these studies demonstrate that our ability to remediate groundwater depends on knowing the contaminants, understanding the fluid mechanics, and interpreting processes in the context of hydrology, geochemistry, and microbiology.…”