Effects of trace PFOA on microbial community and metabolisms: Microbial selectivity, regulations and risks. (1st November 2022)

• Record Type: Journal Article
• Authors: Chen, Congli; Fang, Yuanping; Cui, Xiaochun; Zhou, Dandan
• Is Part Of: Water research. Volume 226(2022)
• Publication Date: 2022-11-01
• Subjects: Perfluorooctanoic acid (PFOA) -- Porous media -- Microbial community -- Antibiotic resistant genes (ARGS) -- Human bacterial pathogens (HBPs) -- Biological risks; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2022.119273
• Languages: English
• ISSNs: 0043-1354

Abstract

Highlights: PFOA promoted biofilm formation in porous media by stimulating EPS production. Glutathione-based antioxidant system defended against oxidative damage of PFOA. Microbes achieved cell membrane repair by regulating metabolic and biosynthetic pathways. Enrichment and generation of efflux ARGs enhanced microbial tolerance to PFOA. An increase in human bacterial pathogens exacerbated the vertical transmission risk of ARGs. Abstract: Perfluorooctanoic acid (PFOA), a "forever chemical", is continuously discharged and mitigated in the environment despite its production and use being severely restricted globally. Due to the transformation, attachment, and adsorption of PFOA in aquatic environments, PFOA accumulates in the porous media of sediments, soils, and vadose regions. However, the impact of trace PFOA in the porous media on interstitial water and water safety is not clear. In this work, we simulated a porous media layer using a sand column and explored the effects of µg-level PFOA migration on microbial community alternation, microbial function regulation, and the generation and spread of microbial risks. After 60 days of PFOA stimulation, Proteobacteria became the dominant phylum with an abundance of 91.8%, since it carried 71% of the antibiotic resistance genes (ARGs). Meanwhile, the halogen-related Dechloromonas abundance increased from 0.4% to 10.6%. In addition, PFOA significantly stimulated protein (more than 1288%) and polysaccharides (more than 4417%) production by up-regulating amino acid metabolism ( p < 0.001) and membrane transport ( p < 0.001) to accelerate the microbial aggregation. More importantly, the rapidly forming biofilm immobilized and blocked PFOA. The more active antioxidant system repaired the damaged cell membrane by significantly up-regulating glycerophospholipid metabolism and peptidoglycan biosynthesis. It is worth noting that PFOA increased the abundance of antibiotic resistance genes (ARGs) and human bacterial pathogens (HBPs) in porous media by 30% and 106%. PFOA increased the proportion of vertical transmission ARGs (vARGs), and co-occurrence network analysis ( r ≥ 0.8, p ≤ 0.01) verified that vARGs were mainly mediated by HBPs. A comprehensive understanding of PFOA interactions with its microecological environment is provided. Graphical abstract: Image, graphical abstract