Zhou Xiaoxuan, Liu Tao, Zhang Shengyi, Kang Bo, Duan Xu, Yan Yuanyuan, Feng Leiyu, Chen Yinguang
State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China.
Staff Education and Training Center Bohai, Drilling Engineering Co., Ltd, China National Petroleum Corporation, 8 Second Street, Economic and Technological Development Zone, Tianjin 300450, PR China.
Sci Total Environ. 2023 Mar 20;865:161122. doi: 10.1016/j.scitotenv.2022.161122. Epub 2022 Dec 29.
Fluorene (Flu) occurs widely in various environments and its toxicity to organisms is well-known. However, the impact of Flu on complicated biochemical processes involving functional microbial community has been reported rarely. In this study, the facilitation of Flu on the volatile fatty acids (VFAs) generation executed by acidogenic microbial population during sludge acidogenic fermentation (37 °C, SRT = 8 d, pH = 10.0) was investigated. The accumulation of VFAs (particularly acetic acid) increased initially and then declined with the increasing of Flu concentration (0-500 mg/kg dry sludge), which reached a maximum (3211.1 mg COD/L) as Flu content was 200 mg/kg dry sludge. The Flu-enhanced VFAs production was primarily attributed to the shift of hydrolysis/acidification, as well as the corresponding functional microbial community and the activity of enzymes. Based on the metagenomics analysis, the conversion of organic substrates, i.e. amino acid and monosaccharide, into VFAs embraced in hydrolysis/acidification shaped by Flu was constructed at the genetic level. The relative abundances of genes included in aminotransfer and deamination process of amino acid and glycolysis of monosaccharide into VFA-precursors (pyruvate, acetyl-CoA and propionyl-CoA), and the further formation of VFAs were improved due to the Flu presence. This study shed light on the Flu-affected microbial processes at the molecular biology level during acidogenic fermentation and was of great significance in resource recovery of sludge containing persistent organic pollutants.
