[Dehydrogenases oxidizing ethanol and acetaldehide in Rhodococcus erythropolis EK-1]

Four types of alcohol- and acetaldehyde dehydrogenases were found in the cells of strain Rhodococcus erythropolis EK1 grown on ethanol. They are as follows: NAD-, NADP-, pyroquinoline quinone (PQQ)- and 4-nitroso-N,N-dimethyl aniline (NDMA)-dependent enzymes. Activity of NAD- and NADP+ -dependent alcohol dehydrogenases, as well as PQQ and NDMA-dependent acetaldehyde dehydrogenases was low and made up 3-11 nmol x min(-1) x mg(-1) of protein. Ethanol oxidation in the given strain is realized by NDMA-dependent alcohol dehydrogenase, which activity reached its maximum value (up to 15 nmol x min(-1) x mg(-1) of protein) in the early exponential growth phase. Acetaldehyde is oxidized with participation of NAD and NADP-dependent dehydrogenases with optimum pH 9.0-9.5. The results obtained are a basis for development of approaches to intensification of surfactants synthesis by Rhodococcus erythropolis EK-1 strain.