Multi-scale analysis of the foaming mechanism in anaerobic digestion of food waste: From physicochemical parameter, microbial community to metabolite response. (30th June 2022)

• Record Type: Journal Article
• Authors: Yang, Pingjin; Peng, Yun; Liu, Hengyi; Wu, Di; Yuan, Ronghuan; Wang, Xiaoming; Li, Lei; Peng, Xuya
• Is Part Of: Water research. Volume 218(2022)
• Publication Date: 2022-06-30
• Subjects: Anaerobic digestion -- extracellular polymeric substances -- foaming -- metabolomics -- surface-active substance; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2022.118482
• Languages: English
• ISSNs: 0043-1354

Abstract

Highlights: Explored the foaming mechanism of anaerobic digestion under three disturbances. Monitored the responses of physicochemical parameters, microorganisms, and metabolites. EPS was significantly correlated with foam height under three disturbances. Microorganisms resisting VFA or FAN could secrete more EPS and promote foaming. The dynamics of metabolites promote EPS accumulation, contributing to foaming. Abstract: Foaming is a key issue that threatens the efficient and stable operation of the anaerobic digestion process. This study introduced three disturbances to induce foaming and explored the responses of physicochemical parameters, microbial communities, and metabolites to reveal the foaming mechanism. Under the three disturbance conditions, extracellular polymeric substances (EPS)-related parameters are significantly positively correlated with foam height, and EPS may cause foam by lowering the surface tension. Microorganisms that are more tolerant to high acid or high ammonia stress environments were identified after foaming, and they could resist the stress environment by producing more EPS. The up-regulated expression of sphingomyelin or ceramide was discovered after foaming, involved in the signal molecular transduction process of cell apoptosis or necrosis, which might be related to EPS production. Pantothenic acid involved in pantothenate and CoA biosynthesis pathways was down-regulated expression after foaming, which might be related to the hindered degradation of EPS. The response of multi-scale parameters in the foaming process shows that EPS is the key factor in foaming events. Graphical abstract: Image, graphical abstract