Abstract:
Methane (CH4) is the most abundant component in natural gas. To reduce its harmful
environmental effect as a greenhouse gas, CH4 can be utilized as a low-cost feed for the
synthesis of methanol by methanotrophs. In this study, several methanotrophs were examined
for their ability to produce methanol from CH4; including Methylocella silvestris, Methylocystis
bryophila, Methyloferula stellata, and Methylomonas methanica. Among these methanotrophs,
M. bryophila exhibited the highest methanol production. The optimum process parameters
aided in significant enhancement of methanol production up to 4.63 mM. Maximum methanol
production was observed at pH 6.8, 30°C, 175 rpm, 100 mM phosphate buffer, 50 mM MgCl2 as
a methanol dehydrogenase inhibitor, 50% CH4 concentration, 24 h of incubation, and 9 mg of
dry cell mass ml-1 inoculum load, respectively. Optimization of the process parameters,
screening of methanol dehydrogenase inhibitors, and supplementation with formate resulted
in significant improvements in methanol production using M. bryophila. This report suggests,
for the first time, the potential of using M. bryophila for industrial methanol production from
CH4.
