Degradation of (—)-Ephedrine by Pseudomonas putida Detection of (—)-Ephedrine: NAD+-oxidoreductase from Arthrobacter globiformis

Abstract

A bacterium utilizing the alkaloid (—)-ephedrine as its sole source of carbon was isolated by an enrichment-culture technique from soil supplemented with 4-benzoyl-1, 3-oxazolidinon-(2). The bacterium was identified as Pseudomonas putida by morphological and physiological studies. The following metabolites were isolated from the culture fluid: methylamine, formaldehyde, methylbenzoylcarbinol (2-hydroxy-1-oxo-1-phenylpropane), benzoid acid, pyrocatechol and cis, cis-muconic acid. A pathway for the degradation of (—)-ephedrine by Pseudomonas putida is proposed and compared with the degradative pathway in Arthrobacter globiformis. The enzyme, which is responsible for the first step in the catabolism of (—)-ephedrine could be demonstrated in extracts from Arthrobacter globiformis. This enzyme catalyses the dehydrogenation of (—)-ephedrine yielding phenylacetylcarbinol/methylbenzoylcarbinol and methylamine. It requires NAD+ as cofactor and exhibits optimal activity at pH 11 in 0.1 M glycine/NaOH buffer. The Kmvalue for (—)-ephedrine is 0.02 mM and for NAD+ 0.11 mM, respectively. No remarkable loss of activity is observed following treatment with EDTA. The enzyme has been shown to react with a wide range of ethanolamines. A slight enrichment was obtained by ammonium sulphate precipitation. The name (—)-ephedrine: NAD+-oxidoreductase (deaminating) is proposed. © 1980, Walter de Gruyter. All rights reserved.