Airborne microorganisms exacerbate the formation of atmospheric ammonium and sulfate. (August 2020)

• Record Type: Journal Article
• Authors: Liu, Huan; Hu, Zhichao; Zhou, Meng; Zhang, Huihui; Li, Zheng; Zhang, Hao; Hu, Jiajie; Yao, Xiangwu; Lou, Liping; Xi, Chuanwu; Zhu, Lizhong; Xu, Xiangyang; Zheng, Ping; Hu, Baolan
• Is Part Of: Environmental pollution. Volume 263(2020)Supplement Part A
• Publication Date: 2020-08
• Subjects: Airborne microorganism -- Nitrogen metabolism -- Sulfur metabolism -- Air pollution -- Haze formation; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2020.114293
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Haze pollution is inseparable from the transformation of air pollutants especially the ammonium and sulfate. Chemical and physical processes play important roles in this transformation. However, the role of microbial processes has rarely been studied. In this report, we applied the cultivation-independent metagenomic approach to study airborne microorganisms, investigating the potential microbial-catalyzed transformation of ammonium and sulfate in PM2.5 samples. Functional genes predict that airborne microorganisms have the potential to catalyze ammonium formation but not ammonium oxidation since no ammoxidation genes were identified. We also found that the frequency of sulfate-forming genes was 1.56 times of those for sulfate-reducing genes. It was speculated that microbial metabolisms in the atmosphere could contribute to the accumulation of ammonium and sulfate. With the increase of PM2.5 concentration, the frequency of functional genes and the relative abundance of genera which involved in nitrogen and sulfur metabolisms increased. That suggested air pollution was conducive to the microbial-mediated formation of ammonium and sulfate. Overall, our results provided evidence for the possible role of microbial processes in the air pollutant transformation and brought a new perspective for studying the formation of secondary air pollutants. Graphical abstract: Image 1 Highlights: Bioaerosols potentially catalyzed ammonium formation but not ammonium oxidation. Bioaerosols preferred to mediate sulfate formation rather than sulfate oxidation. PM2.5 was correlated to the microbial-mediated formation of ammonium sulfate. Abstract : Bioaerosols potentially mediated the haze pollution via the accumulation of ammonium and sulfate, which was the most severe in the heavily polluted air.