Methanol excretion by methylomonas methanica is induced by the supernatant of a methanotrophic consortium

Abstract

Methanotrophs play an important role in mitigating methane (CH4) emissions in ecosystems. They closely interact with other microorganisms forming communities where the cross-feeding of metabolites, presumably methanol (MeOH), is essential for the growth and activity of non-methanotrophs. The experiments in this study were focused on investigating the effect of adding the supernatant from a methanotrophic consortium to pure cultures of Methylomonas methanica. RESULTS: Methanol dehydrogenase inhibition caused the accumulation of MeOH, which resulted in a significant production after 3 h, with 1.99 mmol L−1 CH3OH. The addition of the supernatant was associated with the excretion of MeOH by M. methanica and enhancement of the CH4 consumption rate, despite a reduction in growth. The maximum MeOH concentrations were between 0.7 and 1.5 mmol L−1 CH3OH. CONCLUSION: These findings indicate that MeOH excretion may indeed be linked to a metabolic imbalance, which could potentially be compensated through the cross-feeding of metabolites within the methanotrophic community.