Effects of sliver nanoparticles on nitrogen removal by the heterotrophic nitrification-aerobic denitrification bacteria Zobellella sp. B307 and their toxicity mechanisms.
Mar Pollut Bull
; 203: 116381, 2024 Jun.
Article
em En
| MEDLINE
| ID: mdl-38692001
ABSTRACT
Due to the widespread use of sliver nanoparticles (AgNPs), a large amount of AgNPs has inevitably been released into the environment, and there is growing concern about the toxicity of AgNPs to nitrogen-functional bacteria. In addition to traditional anaerobic denitrifying bacteria, heterotrophic nitrification-aerobic denitrification (HNAD) bacteria are also important participants in the nitrogen cycle. However, the mechanisms by which AgNPs influence HNAD bacteria have yet to be explicitly demonstrated. In this study, the inhibitory effects of different concentrations of AgNPs on a HNAD bacteria Zobellella sp. B307 were investigated, and the underlying mechanism was explored by analyzing the antioxidant system and the activities of key denitrifying enzymes. Results showed that AgNPs could inhibit the growth and the HNAD ability of Zobellella sp. B307. AgNPs could accumulate on the surface of bacterial cells and significantly destroyed the cell membrane integrity. Further studies demonstrated that the presence of high concentration of AgNPs could result in the overproduction of reactive oxygen species (ROS) and related oxidative stress in the cells. Furthermore, the catalytic activities of key denitrifying enzymes (nitrate reductase (NAR), nitrite reductase (NIR), and nitrous oxide reductase (N2OR)) were significantly suppressed under exposure to a high concentration of AgNPs (20 mg·L-1), which might be responsible for the inhibited nitrogen removal performance of strain B307. This work could improve our understanding of the inhibitory effect and underlying mechanism of AgNPs on HNAD bacteria.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Nanopartículas Metálicas
/
Desnitrificação
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Nitrificação
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Nitrogênio
Idioma:
En
Revista:
Mar Pollut Bull
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
China