New insights to the difference in microbial composition and interspecies interactions between fouling layer and mixed liquor in a membrane bioreactor

This work examined fouling-associated microbial community in a carefully controlled laboratory-scale membrane bioreactor (MBR) at different fouling stages. In agreement with the literature, severity was positively correlated bound polysaccharide and protein content (indicators) mixed liquor. UPGMA clustering analysis indices indicated that although biofouling layer (biofilm) liquor possessed highly similar identity, important differences between two communities' structures were also observed. appears to be first comprehensive study apply differential abundance (ANCOM) identify taxa driven divergence structure including Victivallales, Coxiellales, unassigned Microgenomatia Blastocatellia 11–24 (all presented <1% abundance). Network identified Victivallales among few key players biofilm community, respectively. Despite their low abundances, both communities (Pearson's correlation coefficient >0.6) indicators, confirming contributions propensity. The exhibited more complex higher level of inter-species interaction prevalence positive connections (74.6%) compared (42.2%), reflecting stability synergy biofilm. Results from this investigation can support development new control strategies.