Temperature as a conditional regulator of methanogenesis in biogas production: A systematic review

The growing global concern for renewable energy production and sustainable waste management has highlighted anaerobic digestion (AD) as a crucial technology to address energy insecurity and the issues of solid waste pollution, greenhouse gas and carbon footprint. For this purpose, a systematic literature review was presented, whose objective is to assess whether temperature functions as a primary accelerator or a conditional modulator of methanogenesis in biogas production, based on a cross-study comparative synthesis of anaerobic digestion strategies. In this research, temperature emerges as a critical parameter, along with substrate types, other process parameters and the application of various methanogenesis optimization techniques, as the last stage of AD, to deepen the understanding of efficient biogas production. Using PRISMA2020 guidelines and databases of Scopus, and Web of Science (WoS), 51 articles were selected; 31 articles (60.7%) examined temperature’s role, with distributions of 16.1%, 83.8%, and 64.5% for psychrophilic, mesophilic, and thermophilic ranges, respectively, highlighting mesophilic as the most prevalent and operationally robust condition. The reviewed evidence demonstrates that temperature acts primarily as a conditional modulator of methanogenic activity, influencing microbial community structure, metabolic pathway selection, and process stability rather than serving as a universal accelerator of methane production.