Methanol production from CO(2) by resting cells of the methanotrophic bacterium Methylosinus trichosporium IMV 3011.

Methanol production from carbon dioxide was successfully achieved using resting cells of Methylosinus trichosporium IMV 3011 as biocatalysts. Carbon dioxide was reduced to methanol and extracellular methanol accumulation has been found in the carbon dioxide incubations. However, resting cells of methanotrophs have a finite or intrinsic methanol production capacity due to a limiting supply of intracellular reducing equivalent. It has been found that the catabolism of stored Poly-beta -Hydroxybutyrate (PHB) can provide intracellular reducing equivalents to improve the intrinsic methanol production capacity. The initial nitrogen and copper concentration in the culture medium were studied for the accumulation of PHB by M. trichosporium IMV 3011, to expand its potential uses in methanol production from carbon dioxide reduction. It appeared that the total methanol production capacity was increased with increasing PHB content in cells. Resting cells containing 38.6% PHB exhibited the highest total methanol production capacity. But higher PHB accumulation adversely affected the total methanol production capacity. The effects of methanol production process on the survival and recovery of M. trichosporium IMV 3011 were examined. The results showed that the methanol production from carbon dioxide reduction was not detrimental to the viability of methanotrophs.