Semicontinuous methanol biosynthesis by Methylosinus trichosporium OB3b

Methylosinus trichosporium OB3b is a methanotrophic bacterium containing me thane monooxygenase, catalyzing hydroxylation of methane to methanol. When methane is oxidized, the product is subsequently oxidized by methanol dehyd rogenase contained in the same bacterium. To prevent further oxidation of m ethanol, the cell suspension was treated by cyclopropanol, an irreversible inhibitor for methanol dehydrogenase, leading to extracellular methanol acc umulation. However, the batch type of methanol synthesis by M. trichosporiu m OB3b was terminated at ca. 6 mM of methanol, for MMO is inhibited by incr easing methanol concentration. For prolonged methanol accumulation, a semic ontinuous process was carried out. In this process, the reaction was repeat ed several times and the produced methanol was 36.1 mu mol for 6 h. (C) 199 9 Elsevier Science B.V. All rights reserved.