Studies on the biosynthesis of carbapenem antibiotics. I. Biosynthetic significance of the OA-6129 group of carbapenem compounds as the direct precursors for PS-5, epithienamycins A and C and MM 17880.

Based on the working hypothesis that the OA-6129 group of carbapenem compounds might be the direct precursors for PS-5, epithienamycins A and C and MM 17880, Streptomyces fulvoviridis A933 17M9, a producer of PS-5, PS-6, PS-7, PS-8, epithienamycins A, B, C and D, MM 17880, MM 13902 and MM 4550, was subjected to NTG-mutation to provide a blocked mutant numbered 1501 which was found to produce OA-6129 A, OA-6129B1, OA-6129B2 and OA-6129C instead of PS-5, epithienamycins A and C and MM 17880, respectively. In a cell-free system, the parent strain demonstrated an ability to convert OA-6129A to NS-5, whereas the mutant did not. The L- and D-amino acid acylases were also shown to depantothenylate the OA-6129 group of carbapenems.