Improvement of amphotericin B production by a newly isolated Streptomyces nodosus mutant.

Amphotericin B is an effective antifungal antibiotic. However, its production in the wild-type strain of Streptomyces nodosus is relatively low. In this study, a strain of ZJB 20130827, capable of producing amphotericin B, was isolated and identified as S. nodosus based on its physiological and biochemical characteristics as well as its 16S rRNA gene sequence analysis. With N-methyl-N-nitroso-N'-nitroguanidine (NTG) and ultraviolet (UV) treatment, this wild-type strain was mutated for improving the yield of amphotericin B. After NTG and UV treatment, the best mutant N3 was obtained for optimization of fermentation conditions. The production of amphotericin B with N3 was 5,260 mg/L, while the wild-type strain ZJB 20130827 was about 580 mg/L, an increase of 906.9%. A genetically stable mutant strain with high yield of amphotericin B was obtained using NTG and UV. The mutant obtained in this work could potentially be utilized in industrial production of amphotericin B.