The microorganism (KFCC 10740) producing 5'-xanthylic acid is claimed. This microorganism which belongs to a variant of Brevibacterium ammoniagenes 10352 is leaky auxotrophic to adenine and guanine in the growth, contains an inactivated 5'-xanthylic acid aminase and has the high susceptibility to lysozyme, an cell-wall hydrolysing enzyme.
