Oxidation of metadihydroxyphenols by enzymes of Piricularia oryzae.

Chem. 166:397, 1946), which requires biotin, pantothenate (or ,B-alanine), and NA for optimal growth; thiamine is only stimulatory. Pantothenate (or $-alanine) stimulates but is not essential for the growth of CCRF no. 60705. m-Inositol (2.0 ,g/ml) and pyridoxine (2.0 ,g/ml) are only stimulatory, as was the case with T. cremoris ATCC no. 2512. Other vitamins, purines, pyrimidines, etc., had no significant effect upon the growth of CCRF no. 60705. Comparative studies with nonrequiring strains of the same species indicate that the NA requirement of CCRF no. 60705 probably results from genetic blocks similar to those described in Neurospora (Mitchell and Nye, Proc. Natl. Acad. Sci. U. S. 34:1, 1948; Bonner and Beadle, Arch. Biochem. 11:314, 1946), as judged by inability to utilize L-tryptophan, L-kynurenine, or 3-hydroxyanthranilic acid as precursors of NA. Bio-assay and mechanism of action studies with a series of 1, 2-dihydro-s-triazines (Foley, Modest, Cataldo, and Riley, Biochem. Pharmacol., 3:18, 1959) with CCRF no. 60705 in inorganic media, supplemented with NA, biotin, and thiamine, indicates good agreement with data obtained in the usual Lactobacillus arabinosus and NA assay system.