Microbial oxidation of hydrocarbons and related compounds by whole-cell suspensions of the methane-oxidizing bacterium H-2

Previously, a thermophilic obligate methane-oxidizing bacterium, H-2 (type I), was isolated in their laboratory. H-2 is a new type of methylotroph because of the G + C content of DNA; it uses both the ribulose monophosphate pathway and the serine pathway for carbon assimilation and possesses a new quinone. In addition, it was found that resting cell suspensions of H-2 had the ability to oxidize a variety of compounds different from the other methane-oxidizing bacteria as follows. (i) C/sub 1/ to C/sub 8/ n-alkanes are hydroxylated and further oxidized, yielding mixtures of the corresponding alcohols, aldehydes, acids, and ketones. Liquid alkanes are transformed through a different oxidative pathway from that of gaseous ones. (ii) Both gaseous (C/sub 2/ to C/sub 4/) and liquid (C/sub 5/, C/sub 6/) n-alkenes are oxidized to their corresponding 1,2-epoxides. (iii) Liquid monochloro and dichloro n-alkanes (C/sub 5/, C/sub 6/) are oxidized, yielding their corresponding acids or haloacids. (iv) Diethyl ether is oxidized to acetic acid; no ethanol and acetaldehyde are detected. (v) Cyclic and aromatic compounds are also oxidized. (vi) Secondary alcohols (C/sub 3/ to C/sub 10/) are oxidized to their corresponding methyl ketones.