Effects of pimM and pimR on the increase of natamycin production in Streptomyces natalensis

To investigate the effects of PimM and PimR on the increase of natamycin production, exconjugants highly expressing pimM and pimR were constructed. Transcript amounts of pimM and pimR from the exconjugants for their over-expression were 2-fold higher than those of the control strain. Natamycin production of exconjugant for pimM also showed a 2.4-fold increase in liquid culture; however, no effect of pimR was observed. Therefore, promotion of pimM transcription only increases natamycin production.