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 Pseudomonasputida by morphological and physiological studies. The following metabolites were isolated from the culture fluid: methylamine, formaldehyde, methyl- benzoylcarbinol (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 dehydrogena- tion 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 Km value for (-)-ephedrine is 0.02 mM and for NAD+ 0.11 mм, 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.