Bacterial Communities and Functional Genes Stimulated During Anaerobic Arsenite Oxidation and Nitrate Reduction in a Paddy Soil

Li, X; Qiao, J; Li, S; Häggblom, MM; Li, F; Hu, M

HERO ID

7483252

Reference Type

Journal Article

Year

2020

Language

English

PMID

31773946

HERO ID 7483252
In Press No
Year 2020
Title Bacterial Communities and Functional Genes Stimulated During Anaerobic Arsenite Oxidation and Nitrate Reduction in a Paddy Soil
Authors Li, X; Qiao, J; Li, S; Häggblom, MM; Li, F; Hu, M
Journal Environmental Science & Technology
Volume 54
Issue 4
Page Numbers 2172-2181
Abstract Microbial arsenite (As(III)) oxidation associated with nitrate (NO3-) reduction might be an important process in diminishing arsenic bioavailability and toxicity to rice when paddy soils are contaminated by arsenic. In a noncontaminated soil, however, the responses of bacterial communities and functional genes to As(III) under nitrate-reducing conditions are poorly understood. In this study, anaerobic paddy soil microcosms were established with As(III) and/or NO3- to investigate how the bacterial communities and their functional genes were stimulated during As(III) oxidation and nitrate reduction. Microbial oxidation of As(III) to As(V) was substantially accelerated by nitrate addition, while nitrate reduction was not affected by As(III) addition. Metagenomic analysis revealed that nitrate-reducing bacteria were principally affiliated with Pseudogulbenkiania, with narG, nirS, and norBC genes. Putative As(III)-oxidizing bacteria were dominated by an Azoarcus sp. with As(III) oxidase genes aioA and aioB detected in its draft genome, which also had complete sets of denitrification genes (mainly, napA, nirK, and nosZ). Quantitive PCR analysis confirmed that the abundance of Azoarcus spp., aioA, and nosZ genes was enhanced by As(III) addition. These findings suggest the importance of Azoarcus- and Pseudogulbenkiania-related spp., both of which showed various physio-ecological characteristics for arsenic and nitrogen biogeochemistry, in coupling As(III) oxidation and nitrate reduction in flooded paddy soil.
Doi 10.1021/acs.est.9b04308
Pmid 31773946
Wosid WOS:000514759000013
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English