SYNTHESIS OF NITRIC-OXIDE FROM THE 2 EQUIVALENT GUANIDINO NITROGENS OF L-ARGININE BY LACTOBACILLUS-FERMENTUM

Ten strains of Lactobacillus fermentum that differed in origin convert ed metmyoglobin to nitrosylmyoglobin [a pentacoordinate nitric oxide ( NO) complex of Fe(II) myoglobin] in MRS broth at pH 4.3. Of the 10 str ains, L. fermentum IFO 3956 possessed the strongest capacity to conver t metmyoglobin to nitrosylmyoglobin. This strain synthesizes NO enzyma tically from the two equivalent guanidino nitrogens of L-arginine. To our knowledge, this demonstrates for the first time the production of NO synthesized from the guanidino nitrogens of L-arginine by lactic ac id bacteria. IFO 3956 may possess a bacterial NO synthase.