Studies on the Fermentative Production of 5′-Guanylic Acid by Microorganism Part 1. Derivation of XMP Aminase-Producing Mutants form Brevibacterium ammoniagenes

By the treatment of various mutagens, a number of 5'-guanylic acidproducing from 5'-xanthylic acid were obtained from Brevibacterium ammoniagenes ATCC 6871. The indispensable genetic characters of the mutants were adenine requirement, lack of GMP-reductase and mutation to adenosine resistance from adenosine sensitiveness. Main product of these mutants from 5'-xanthylic acid was 5'-guanylic acid. The substance was isolated in a crystalline form the culture broth of BA 17-2, and identified as 5'-guanylic acid by means of paper chromatography, ultra violet, absorption spectra, and infra red spectrum.