A single cycle of strain improvement was performed in Saccharopolyspora erythraea mutB and 15 genotypes influencing erythromycin production were found. Genotypes generated by transposon mutagenesis appeared in the screen at a frequency of ~3%. Mutations affecting central metabolism and regulatory genes were found, as well as hydrolases, peptidases, glycosyl transferases and unknown genes. Only one mutant retained high erythromycin production when scaled-up from micro-agar plug fermentations to shake flasks. This mutant had a knockout of the cwh1 gene (SACE_1598), encoding a cell-wall-associated hydrolase. The cwh1 knockout produced visible growth and morphological defects on solid medium. This study demonstrated that random transposon mutagenesis uncovers strain improvement-related genes potentially useful for strain engineering.
Anti-Bacterial Agents/biosynthesis , Biosynthetic Pathways/genetics , DNA Transposable Elements , Erythromycin/biosynthesis , Mutagenesis, Insertional , Saccharopolyspora/genetics , Saccharopolyspora/metabolism , Genes, Bacterial , Genome, Bacterial , Metabolic Engineering/methods
