Selective evolution of methanogenic communities by β-lactam antibiotics promotes methane production.

Biomethane, a clean energy source, plays a crucial role in addressing global energy and environmental challenges. However, its production has long been limited by the complexity of methanogenic precursor synthesis and the involvement of diverse microbial strains, creating a bottleneck in methane conversion. To address this, the present study explores the potential of the β-lactam antibiotic amoxicillin (AMX) to enhance methanogenesis by selectively shaping microbial communities while preserving core methanogenic pathways. Results indicate that the addition of AMX significantly improves methanogenic performance. By day 25, methane yield increased by 3.89-fold, and carbon substrate utilization efficiency improved by 15.5% compared to the control group. This enhancement is linked to the selective effect of AMX on the methanogenic community, leading to a 61.51% increase in the relative abundance of methanogenic archaea. This approach optimizes the process by bypassing three stages of methane precursor synthesis, reducing interfering bacteria, and improving methanogenic efficiency and process controllability, all while showing no significant negative environmental impacts from the added antibiotics. IMPORTANCE: This study holds significant importance in advancing biomethane production, a clean and renewable energy source. By utilizing amoxicillin, the research promotes the selective growth of methane-producing microbes while suppressing harmful ones, resulting in faster and more efficient methane production with enhanced process control. In addition, amoxicillin degrades rapidly within the system, resulting in minimal negative environmental impact. This work provides a promising and eco-friendly approach to optimize biomethane production, offering a viable and sustainable solution for energy generation from waste.