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

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.

Microbial Community Redundancy and Resilience Underpins High-Rate Anaerobic Treatment of Dairy-Processing Wastewater at Ambient Temperatures

“…Furthermore, a decrease of 95% of average specific methane yield and a corresponding decrease in the abundances of Methanosarcina and Methanothrix was observed at pH 8.5 in a two-phase anaerobic co-digestion of pig manure with maize Straw (Zhang et al, 2016b). Also, in other environments, such as soil, pH was reported to be one of the main factors responsible for shaping the microbial community (Bartram et al, 2014;Wu et al, 2017). Despite the microbial community changes, the pilot reactor performance was always able to recover, with efficient wastewater treatment performance (high methane content, good COD removal).…”

A communal catalogue reveals Earth’s multiscale microbial diversity

“…Microbial community richness has been found to correlate with environmental factors, including pH and temperature 3,33,35,36 . For example, richness has been shown to increase up to neutral pH 36 and often decrease above neutral pH 3,35 in soil communities.…”

“…Microbial community richness has been found to correlate with environmental factors, including pH and temperature 3,33,35,36 . For example, richness has been shown to increase up to neutral pH 36 and often decrease above neutral pH 3,35 in soil communities. Richness has been shown to increase with temperature up to a limit and then decrease beyond that limit in seawater (maximum at ~19 °C) 33 and to increase with temperature in soil (up to at least ~26 °C) 36 .…”

Plant species and soil type influence rhizosphere bacterial composition and seedling establishment on serpentine soils

“…On the other hand, soil physical 63 and chemical properties can also be strong drivers of rhizosphere and rhizoplane microbial 64 community composition, particularly on large scales or across soils that vary widely in 65 composition. For example, pH (Bartram et al 2014;Wu et al 2017), salinity (Sardinha et al 2003; 66 Dillon et al 2013), drought (Barnard, Osborne and Firestone 2013; Chodak et al 2015), and the 67 presence of heavy metals (Wood et al 2016) all influence soil and root-associated microbial 68 community structure. Still, the relative importance of plant identity and soil chemistry across soil 69 gradients remains difficult to predict in large part because plant species are often restricted to 70 particular soil types.…”