title: Production of guanosine-5'-monophosphate and inosine-5'-monophosphate by fermentation.
abstract: A biotin-requiring coryneform bacterium which produces glutamic acid was mutated to adenine dependency. The adenine-requiring strain, which excreted insoine-5'-monophosphate (IMP), was further mutated to xanthine dependency. As expected, IMP was also excreted by this mutant. The mutant strain was reverted to xanthine independence in an attempt to obtain a culture with an altered IMP dehydrogenase which would be less sensitive to feedback inhibition by guanosine-5'-monophosphate (GMP). A revertant was obtained which produced GMP and IMP, each at 0.5 g per liter. The reversion to xanthine independence had resulted in a concomitant requirement for isoleucine, leucine, and valine. Further mutation to increased nutritional requirements led to culture MB-1802, which accumulated 1 g per liter each of GMP and IMP. Both nucleotides were isolated in pure form. The concentrations of GMP and IMP produced by MB-1802 were four times that of cytidylate, uridylate, or adenylate, indicating that the mechanism of GMP and IMP production was direct and not via ribonucleic acid breakdown.
authors.affiliation: Merck Sharp & Dohme Research Laboratories, Division of Merck & Co., Inc., Rahway, New Jersey.
authors.forename: A L
authors.initials: AL
authors.lastname: Demain
authors.forename: M
authors.initials: M
authors.lastname: Jackson
authors.forename: R A
authors.initials: RA
authors.lastname: Vitali
authors.forename: D
authors.initials: D
authors.lastname: Hendlin
authors.forename: T A
authors.initials: TA
authors.lastname: Jacob