Enhanced production of nikkomycin X by over-expression of SanO, a non-ribosomal peptide synthetase in Streptomyces ansochromogenes.

A recombinant strain was constructed by introducing pWO6 which contains the sanO gene encoding a non-ribosomal peptide synthetase (NRPS) into Streptomyces ansochromogenes 7100 (wild-type strain). The bioassay of nikkomycin indicated that the anti-fungal activity was enhanced in the recombinant strain in comparison with the wild-type strain. HPLC analysis revealed that 1200 mg nikkomycin X l(-1) was produced in the recombinant strain after growth for 6 d, which was about twice that of the wild-type strain. RT-PCR also indicated that higher transcription of the sanO gene was observed in the recombinant strain in contrast with wild-type strain.