Fe(II) Oxidation Shaped Functional Genes and Bacteria Involved in Denitrification and Dissimilatory Nitrate Reduction to Ammonium from Different Paddy Soils

作者：Dandan Pan, Pengcheng Chen, Guang Yang, Rumiao Niu, Yan Bai, Kuan Cheng, Guoyong Huang, Tongxu Liu, Xiaomin Li, Fangbai Li · 发表于：Environmental Science & Technology · 年份：2023 · DOI：10.1021/acs.est.3c06337 · 被引用次数：65 · 研究领域：Wastewater Treatment and Nitrogen Removal、Microbial Community Ecology and Physiology、Microbial Fuel Cells and Bioremediation

Microbial nitrate reduction can drive Fe(II) oxidation in anoxic environments, affecting the nitrous oxide emission and ammonium availability. The nitrate-reducing Fe(II) oxidation usually causes severe cell encrustation via chemodenitrification and potentially inhibits bacterial activity due to the blocking effect of secondary minerals. However, it remains unclear how Fe(II) oxidation and subsequent cell encrustation affect the functional genes and bacteria for denitrification and dissimilatory nitrate reduction to ammonium (DNRA). Here, bacteria were enriched from different paddy soils with and without Fe(II) under nitrate-reducing conditions. Fe(II) addition decelerated nitrate reduction and increased NO 2 – accumulation, due to the rapid Fe(II) oxidation and cell encrustation in the periplasm and on the cell surface. The N 2 O accumulation was lower in the treatment with Fe(II) and nitrate than that in the treatment with nitrate only, although the proportions of N 2 O and NH 4 + to the reduced NO 3 – were low (3.25% ∼ 6.51%) at the end of incubation regardless of Fe(II) addition. The dominant bacteria varied from soils under nitrate-reducing conditions, while Fe(II) addition shaped a similar microbial community, including Dechloromonas, Azospira, and Pseudomonas . Fe(II) addition increased the relative abundance of napAB, nirS, norBC, nosZ, and nirBD genes but decreased that of narG and nrfA, suggesting that Fe(II) oxidation favored denitrification in the periplasm and NO...