Abstract: Methylosinus trichosporium IMV 3011 was cultivated on methanol vapor as carbon source. The methanol vapor-grown culture was adapted to grow on liquid methanol with its gradually increasing concentrations from 0.01% to 1%(volume fraction). After adaptation to high methanol levels, M. trichosporium IMV 3011 was cultured on methanol-methane to obtain a large quantity of cells with methane monooxygenase (MMO) activity. The effect of methanol on the growth of M. trichosporium IMV 3011 and MMO activity was studied. The growth of methanotrophic bacteria was significantly enhanced in comparison to the absence of methanol. In the batchwise epoxidation, the epoxidation capacity of M. trichosporium IMV 3011 was enhanced when methanol was provided, indicating that the methanol could act as an electron donator to drive the synthesis of epoxypropane. Also, the possibility of methanol-driven continuous synthesis of epoxypropane by M. trichosporium IMV 3011 was explored in a membrane reactor. At the most suitable liquid flow velocity of6 ml/h, the epoxypropane concentration in eluate was 2.19 mmol/L and the residual methanol concentration was 1.08 mmol/L. The product inhibition was overcome owing to the continuous removal of epoxypropane. In this process, the reactor was operated continuously for 192 h, and the epoxypropane concentration in eluate was kept to about 1.35 mmol/L. Direct counts and plate counts for M. trichosporium IMV 3011 showed that the bacteria could survive in the process of methanol-driven epoxypropane synthesis.

Key words: methanol-driving, methanotrophic bacteria, coenzyme, nicotinamide adenine dinucleotide (NADH), biosynthesis, propene, epoxypropane