SPLITTING OF {varepsilon}-CAPROLACTAM AND OTHER LACTAMS BY BACTERIA

-Caprolactam-utilizing bacteria split -caprolactam, -valerolactamand -butyrolactam, and produce the -amino acids correspondingto them. This activity is lost when cells are grown on 6-amino-caproicacid or ammonium adipate, and reappears when cells are incubatedwith either -caprolactam or -valerolactam as the sole majororganic nutrient. Chloramphenicol inhibits this adaptation.The enzyme splitting those lactams is one and the same. It maybe called "lactam-splitting enzyme". But attempts to demonstratethe enzymic activity in a cell-free system has not yet beensuccessful. (Received September 9, 1965; )     

BACTERIAL BREAKDOWN OF {varepsilon}-CAPROLACTAM AND ITS CYCLIC OLIGOMERS

Eleven different types of bacteria were isolated which werecapable of growing on -caprolactam, the monomeric material fornylon 6 polyamide, as the sole source of both carbon and nitrogen. The optimal concentration of -caprolactam for the bacterialgrowth was about 0.6% in a synthetic liquid medium enrichedwith a small amount of yeast extract. The bacterial strains grew also on -butyrolactam, -valerolactamand the -amino acids corresponding to these lactams and -caprolactam.Ammonium adipate was a good substrate for the growth of allthe strains. One strain of Corynebacterium aurantiacum was found to be capableof utilizing cyclic and linear oligomers of 6-aminocaproic acidwith an exception of cyclic dimer. The strains of corynebacteria required vitamin B₁ for growth. Metabolism of -caprolactam and related compounds is discussedbriefly. (Received September 9, 1965; )