Effects of carbon ion beam-induced mutagenesis for the screening of RED production-deficient mutants of Streptomyces coelicolor JCM4020

<jats:p><jats:italic>Streptomyces lividans</jats:italic> TK23 interacts with mycolic acid-containing bacteria (MACB), such as <jats:italic>Tsukamurella pulmonis</jats:italic> TP-B0596, and this direct cell contact activates its secondary metabolism (e.g., the production of undecylprodigiosin: RED). Here, we employed carbon (<jats:sup>12</jats:sup>C<jats:sup>5+</jats:sup>) ion beam-induced mutagenesis to investigate the signature of induced point mutations and further identify the gene(s) responsible for the production of secondary metabolites induced by <jats:italic>T</jats:italic>. <jats:italic>pulmonis</jats:italic>. We irradiated spores of the <jats:italic>Streptomyces coelicolor</jats:italic> strain JCM4020 with carbon ions to generate a mutant library. We screened the RED production-deficient mutants of <jats:italic>S</jats:italic>. <jats:italic>coelicolor</jats:italic> by mixing them with <jats:italic>T</jats:italic>. <jats:italic>pulmonis</jats:italic> TP-B0596 on agar plates, identifying the red/white phenotype of the growing colonies. Through this process, we selected 59 RED-deficient mutants from around 152,000 tested spores. We resequenced the genomes of 16 mutants and identified 44 point mutations, which revealed the signatures induced by <jats:sup>12</jats:sup>C<jats:sup>5+</jats:sup>-irradiation. Via gene complementation experiments, we also revealed that two genes—glutamate synthase (<jats:italic>gltB</jats:italic>) and elongation factor G (<jats:italic>fusA</jats:italic>)—are responsible for the reduced production of RED.</jats:p>