Insight into universality and characteristics of nitrate reduction coupled with arsenic oxidation in different paddy soils.
Sci Total Environ
; 866: 161342, 2023 Mar 25.
Article
em En
| MEDLINE
| ID: mdl-36603609
ABSTRACT
Nitrate reduction coupled with arsenic (As) oxidation strongly influences the bioavailability and toxicity of As in anaerobic environments. In the present study, five representative paddy soils developed from different parent materials were used to investigate the universality and characteristics of nitrate reduction coupled with As oxidation in paddy soils. Experimental results indicated that 99.8 % of highly toxic aqueous As(III) was transformed to dissolved As(V) and Fe-bound As(V) in the presence of nitrate within 2-8 d, suggesting that As was apt to be reserved in its low-toxic and nonlabile form after nitrate treatment. Furthermore, nitrate additions also significantly induced the higher abundance of 16S rRNA and As(III) oxidase (aioA) genes in the five paddy soils, especially in the soils developed from purple sand-earth rock and quaternary red clay, which increased by 10 and 3-5 times, respectively, after nitrate was added. Moreover, a variety of putative novel nitrate-dependent As(III)-oxidizing bacteria were identified based on metagenomic analysis, mainly including Aromatoleum, Paenibacillus, Microvirga, Herbaspirillum, Bradyrhizobium, Azospirillum. Overall, all these findings indicate that nitrate reduction coupled with As(III) oxidation is an important nitrogen-As coupling process prevalent in paddy environments and emphasize the significance of developing and popularizing nitrate-based biotechnology to control As pollution in paddy soils and reduce the risk of As compromising food security.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Arsênio
/
Oryza
/
Arsenitos
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Sci Total Environ
Ano de publicação:
2023
Tipo de documento:
Article