Linking microbial community composition to farming pattern in selenium-enriched region: Potential role of microorganisms on Se geochemistry

Selenium (Se) is an essential micronutrient for lives. Indigenous microbial communities play an important role on Se geochemistry in soils. In this study, the microbial community composition and functions of 53 soil samples were investigated using high-throughput sequencing. Samples were divided into 3 groups with different farming types based on the measured geochemical parameters and microbial functional structures. Results indicated that putative Se related bacteria Bacillus, Dyella, Paenibacillus, Burkholderia and Brevibacillus were dominant in dryland plantation soils which were characterized with higher available Se and low contents of H 2 O, total organic carbon (TOC), NH 4 + and NO 2 -. In contrast, the putative denitrifier Pseudomonas dominated in flooded paddy soils with higher TOC, NO 3 - and organic Se, whereas genera Rhizobium, Nitrosospira , and Geobacter preferred woodland soils with higher oxidation-reduction potential (ORP), pH, NH 4 + and Fe. Farming patterns resulted in distinct geochemical parameters including moisture, pH, ORP, TOC, and contents of soluble Fe, NO 2 - and NH 4 + , shaping the microbial communities, which in turn affected Se forms in soils. This study provides a valuable insight into understanding of Se biogeochemistry in soils and prospective strategy for Se-rich agriculture production. (c) 2021 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.

Automated summary

This study investigated the microbial community composition and functions in different farming soils and found that the farming patterns influenced the geochemical parameters and microbial communities, subsequently affecting the forms of selenium in soils.