Beyond methane consumption: exploring the potential of methanotrophic bacteria to produce secondary metabolites.

Microbial methane-consuming communities significantly impact biogeochemical processes and greenhouse gas emissions. In this study, we explored secondary metabolites produced by methane-oxidizing bacteria (MOB) and their ecological roles. We analyzed the volatile profiles of four MOB strains under controlled conditions and conducted a meta-analysis using high-quality genomes from 62 cultured MOB strains and 289 metagenome-assembled genomes to investigate their potential for producing secondary metabolites. Results show species-specific volatile production, such as germacrene by Methylobacter luteus, which may play a role in the regulation of environmental methane consumption. The meta-analysis revealed that biosynthetic gene clusters (BGCs) for terpenes and β-lactones were more prevalent in the Methylocystaceae and/or Beijerinckiaceae families, while aryl polyene BGCs were dominant in the Methylococcaceae family, reflecting habitat-specific adaptations. These findings advance our understanding of the metabolic capabilities of MOB and underscore the importance of integrating experimental data with genomic and metabolomic analyses to elucidate their ecology, environmental interactions, and contributions to methane cycling.