Oxidation of organic compounds by propane monooxygenase ofRhodococcus erythropolis 3/89
The ability of propane monooxygenase ofRhodococcus erythropolis 3/89 to catalyze oxidation of higher liquid alkenes and aromatic hydrocarbons was studied. Optimal conditions of tetradecene epoxidation and benzene hydroxylation were found. Under these conditions, oxidation was shown to be accompanied by a 100% conversion of benzene to phenol.
Production of 1,2-epoxyalkanes from 1-alkenes by Nocardia corallina B-276
SummaryA gaseous hydrocarbon-assimilating microorganism, Nocardia corallina, grew on 1-alkenes (C3, C4 and C13 to C18) and produced corresponding 1,2-epoxyalkanes. One of the products, 1,2-epoxytetradecane, had a positive rotation [α]D20=+8.6°. The concentration of propyleneoxide reached 0.6 g/l after 5 days of cultivation. Accumulation of 1,2-epoxytetradecane continued till the end of cultivation when the pH was not controlled, though production stopped in a 24 h cultivation when the pH was controlled at an optimum pH for growth. Propylene-grown cells produced 1,2-epoxytetradecane from 1-tetradecene and degraded tetradecane. In the presence of chloramphenicol, propylene-grown cells did not degraded tetradecane though 1,2-epoxytetradecane was produced from 1-tetradecene. A spontaneous mutant, which neither grew on propylene nor produced propyleneoxide, was isolated. This strain grew on tetradecane and 1-tetradecene but produced only a trace amount of 1,2-epoxytetradecane from 1-tetradecene.
Microbial Oxidation of Gaseous Hydrocarbons: Production of Methyl Ketones from Their Corresponding Secondary Alcohols by Methane- and Methanol-Grown Microbes
Cultures of methane- or methanol-utilizing microbes, including obligate (both types I and II) and facultative methylotrophic bacteria, obligate methanol utilizers, and methanol-grown yeasts were isolated from lake water of Warinanco Park, Linden, N.J., and lake and soil samples of Bayway Refinery, Linden, N.J. Resting-cell suspensions of these, and of other known C1-utilizing microbes, oxidized secondary alcohols to their corresponding methyl ketones. The product methyl ketones accumulated extracellularly. Succinate-grown cells of facultative methylotrophs did not oxidize secondary alcohols. Among the secondary alcohols, 2-butanol was oxidized at the highest rate. The optimal conditions for in vivo methyl ketone formation were compared among five different types of C1-utilizing microbes. Some enzymatic degradation of 2-butanone was observed. The product, 2-butanone, did not inhibit the oxidation of 2-butanol. The rate of the 2-butanone production was linear for the first 4 h of incubation for all five cultures tested. A yeast culture had the highest production rate. The optimum temperature for the production of 2-butanone was 35°C for all the bacteria tested. The yeast culture had a higher temperature optimum (40°C), and there was a reasonably high 2-butanone production rate even at 45°C. Metal-chelating agents inhibit the production of 2-butanone, suggesting the involvement of metal(s) in the oxidation of secondary alcohols. Secondary alcohol dehydrogenase activity was found in the cell-free soluble extract of sonically disrupted cells. The cell-free system requires a cofactor, specifically nicotinamide adenine dinucleotide, for its activity. This is the first report of a nicotinamide adenine dinucleotide-dependent, secondary alcohol-specific enzyme.