Methanol Biosynthesis from Methane Using Methylosinus trichosporium OB3b Grown in Medium Containing High Copper Concentration

Methanol production from methane in a batch reactor using whole cells of Methylosinus trichosporium OB3b grown in medium containing 50 mu mol L-1 copper was examined. Methanol productivity of the biocatalyst was 9.56 mmol g-dry cell(-1) h(-1), about 3-fold higher than that of the bacteria grown in medium containing 1.25 mu mol L-1 copper, indicating that methanol productivity of the methane bioconversion is improved by higher copper concentration in the growth medium. Methanol production almost ceased after 60-h reaction due to product inhibition. Therefore, repeated batch reaction was performed, in which the bacterial cells were collected after 24-h reaction and re-used in the next cycle. In the fourth cycle, 83 % of the methanol productivity was retained. About 856 mmol g-dry cell(-1) of methanol was obtained after 4 cycles, which was 3.7-fold higher than the methanol obtained in a single batch reaction for 96 h.

Automated summary

Methanol productivity from methane bioconversion can be improved by higher copper concentration in the growth medium, and repeated batch reactions can increase the overall methanol yield.