信号分子对活性污泥降解多环芳烃影响及群落解析OA

Signaling molecules are extensively employed in the environmental field.While traditional signaling molecules have been shown to promote the degradation of polycyclic aromatic hydrocarbons(PAHs)by single bacterial strains,their effects on complex communities remain unknown.The traditional signaling molecule acyl homoserine lactone(AHL)and the novel signaling molecule indole are separately added to activated sludge microcosms to explore the effects of signaling molecules on the degradation of PAHs by activated sludge.The results indicate that signaling molecules can enhance the degradation rate of PAHs.After stimulation by signaling molecules,the hydrophobicity of the cell surface of activated sludge,the content of extracellular polymeric substances(EPS),and the ratio of protein to polysaccharide in EPS all increase,while the downstream PAHs-degrading enzyme activities are simultaneously enhanced,all of which are conducive to improving the bioavailability of PAHs.High-throughput sequencing results reveal an increased abundance of bacteria capable of degrading PAHs within the community,particularly those regulated by signaling molecules,such as Alicycliphilus and Hydrogenophaga,which become predominant.The research results offer novel insights and theoretical guidance for the application of quorum sensing(QS)signaling molecules in regulating PAHs degradation.