Bacterial Racemization ofα-Amino-ε-caprolactam

Abstract

Several bacteria were isolated from soil which grew on D- and L-aminolactam and whose cells had an activity to racemize them. They were identified as Achromobacter obae, A. cycloclastes, Alcaligenes faecalis and Flavobacterium arborescens. Racemization of D- and L-aminolactam was investigated using lyophilized cells of A. obae. The optimum pH value of the reaction was about 8.0. The racemizing activity was completely inhibited by 10-4 M hydroxylamine, and the inhibition was removed by 10-4 M pyridoxal phosphate. Five percent D- and L-aminolactam solutions were completely racemized with a concomitant slight formation of L-lysine.