Unveiling the mechanism of hunger stress enhancing methane production from low-strength wastewater: Insight from organic conversion and microbial metabolism perspective

Abstract

Domestic wastewater, rich in biodegradable substances, presents a potential resource for methane production through anaerobic digestion. However, low organic concentrations in low-strength wastewater hinder microbial activity and degrade treatment efficiency. This study explored the regulatory effects of short-term hunger stress on microbial communities in an anaerobic fluidized bed membrane bioreactor (AFMBR) treating low-strength wastewater, aiming to enhance methane production and overall treatment performance. The results demonstrated that hunger stress had a significant impact on the adaptability of microbial communities, resulting in a 9.1% increase in COD removal efficiency and a 31.5 % increase in methane production. Notably, the relative abundance of key genera such as Methanosaetaceae and Bacteroidetes increased after hunger treatment, indicating a shift towards more efficient methanogenic pathways. Additionally, functional gene analysis revealed increased transcriptional activity, suggesting that hunger stress promoted metabolic processes essential for methane generation. This study highlights the innovative approach of using hunger stress to regulate microbial community dynamics in anaerobic systems, offering valuable insights into optimizing methane production from low-strength wastewater. The findings contribute to advancing anaerobic digestion technologies and improving the sustainability of wastewater treatment processes.