Influence of kaolin on methane oxidation by Methylomonas methanica in gas phase bioreactors

Significant levels of methane are liberated from the coal face and subterranean pockets during coal mining. This methane poses an explosion hazard in mines and when released into the atmosphere, acts as a greenhouse gas which contributes to global warming. Methanotrophic bacteria in gas phase bioreactors (GPBs) offer the potential to convert this methane to less deleterious substances; however, it is critical that reaction rates be maximized. The effect of kaolin on rates of methane oxidation by Methylomonas methanica grown in GPBs was assessed. The amendment of GPBs with a 4% kaolin solution significantly increased methane removal by M. methanica versus non-kaolin-amended controls. The maximum velocities ( v max ) were 604.1 mg methane min −1 GPB −1 in the control compared to 1156.6 mg methane min −1 GPB −1 in the kaolin-amended bioreactors, while the Michaelis constants ( K m ) were 15.87 and 60.52 mg methane GPB −1, respectively.