Growth-promoting effect of cyanocobalamin on Methylosinus trichosporium OB3b culture under high copper concentration for methanol synthesis from methane

Abstract

Depleting fuel resources have accelerated the requirement for more sustainable methanol production from methane. This study examined the effects of cyanocobalamin on the growth of methane-oxidizing bacteria, Methylosinus trichosporium OB3b under high copper concentration, which is the promising biocatalyst for the energy-efficient methanol synthesis from methane. M. trichosporium OB3b was cultured in medium containing 50 μM copper ions with cyanocobalamin. Its growth patterns, and the quantities of intracellular enzymes involved in methane metabolism were investigated. Cyanocobalamin affected the bacteria culture growth during the initial period; the lag phase usually seen in M. trichosporium OB3b culture was not observed. However, cyanocobalamin suppressed the growth of M. trichosporium OB3b in the late period, where particulate methane monooxygenase (pMMO) expression decreased. These results support the use of cyanocobalamin for preparing bacterial inoculum with M. trichosporium OB3b culture as a biocatalyst for the large-scale bioprocess of synthesizing methanol from methane.