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

BACKGROUND Methanotrophs play an important role in mitigating methane (CH 4 ) 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 CH 3 OH. The addition of the supernatant was associated with the excretion of MeOH by M. methanica and enhancement of the CH 4 consumption rate, despite a reduction in growth. The maximum MeOH concentrations were between 0.7 and 1.5 mmol L −1 CH 3 OH. 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.