2.4.1.317 Characterization and targeted disruption of a glycosyltransferase gene in the tylosin producer, Streptomyces fradiae Streptomyces fradiae 2.4.1.317 Characterization and targeted disruption of a glycosyltransferase gene in the tylosin producer, Streptomyces fradiae Streptomyces fradiae T59235