PH is the primary determinant of the bacterial community structure in agricultural soils impacted by polycyclic aromatic hydrocarbon pollution

Yucheng Wu,Yucheng Wu,Yucheng Wu,Zhenfa Zhang,Xiangui Lin,Xiangui Lin,Xiangui Lin,Jun Zeng,Jun Zeng,Jun Zeng,Qinghe Zhu,Qinghe Zhu

doi:10.1038/srep40093

Abstract

Acidification and pollution are two major threats to agricultural ecosystems; however, microbial community responses to co-existed soil acidification and pollution remain less explored. In this study, arable soils of broad pH (4.26–8.43) and polycyclic aromatic hydrocarbon (PAH) gradients (0.18–20.68 mg kg−1) were collected from vegetable farmlands. Bacterial community characteristics including abundance, diversity and composition were revealed by quantitative PCR and high-throughput sequencing. The bacterial 16S rRNA gene copies significantly correlated with soil carbon and nitrogen contents, suggesting the control of nutrients accessibility on bacterial abundance. The bacterial diversity was strongly related to soil pH, with higher diversity in neutral samples and lower in acidic samples. Soil pH was also identified by an ordination analysis as important factor shaping bacterial community composition. The relative abundances of some dominant phyla varied along the pH gradient, and the enrichment of a few phylotypes suggested their adaptation to low pH condition. In contrast, at the current pollution level, PAH showed marginal effects on soil bacterial community. Overall, these findings suggest pH was the primary determinant of bacterial community in these arable soils, indicative of a more substantial influence of acidification than PAH pollution on bacteria driven ecological processes.

Highlights

(0.18–20.68 mg kg−1) were collected from vegetable farmlands
At the current pollution level, polycyclic aromatic hydrocarbons (PAHs) showed marginal effects on soil bacterial community. These findings suggest pH was the primary determinant of bacterial community in these arable soils, indicative of a more substantial influence of acidification than PAH pollution on bacteria driven ecological processes
We examined the bacterial communities in agricultural soils impacted by both acidification and PAH pollution based on the Illumina MiSeq sequencing platform

Summary

Introduction

(0.18–20.68 mg kg−1) were collected from vegetable farmlands. Bacterial community characteristics including abundance, diversity and composition were revealed by quantitative PCR and highthroughput sequencing. The relative abundances of some dominant phyla varied along the pH gradient, and the enrichment of a few phylotypes suggested their adaptation to low pH condition Overall, these findings suggest pH was the primary determinant of bacterial community in these arable soils, indicative of a more substantial influence of acidification than PAH pollution on bacteria driven ecological processes. Considerable efforts have been invested to address how bacteria respond to the changing environment, since the terrestrial ecosystems are increasingly under the pressure of human activities Cropland is such a hotspot of anthropogenic disturbance due to the lasting input of agricultural chemicals and pollutants over recent decades, resulting in significant changes in soil characteristics as exemplified by acidification[2] and pollution[3], in some rapidly developed areas. Polycyclic aromatic hydrocarbons (PAHs) has been found to be widespread in terrestrial environments[12], posing

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