Microbial Metabolism of Amino Ketones: D-1-Aminopropan-2-ol and Aminoacetone Metabolism in Escherichia coli

SUMMARY Aminoacetone was formed from d- or l-i -aminopropan-2-ol, or both, by a variety of micro-organisms. An oxidoreductase capable of oxidizing d-i-aminopropan-2-ol to aminoacetone was purified 38-fold from Escherichia coli. It was inactive with l -i -aminopropan-2-ol, l-threonine and dl-glycerol-1-phosphate. It was highly active with a variety of diols and hydroxyketones and not narrowly specific as reported by other workers (Dekker & Swain, 1968). The effect of growth conditions on activity suggested involvement in mono- or di-hydroxyacetone metabolism. Although d-i-aminopropan-2-ol oxidation was demonstrated in crude extracts of a number of other bacteria, a relationship between l-threonine and d-i-aminopropan-2-ol dehydrogenases and vitamin B12 biosynthesis does not appear likely.