Efficient production of valinomycin by the soil bacterium, Streptomyces sp. ZJUT-IFE-354

Dong Zhang; Zhi Ma; Hanchi Chen; Weilin Ma; Jiawei Zhou; Qing Wang; Chan Min; Yuele Lu; Xiaolong Chen

doi:10.1007/s13205-021-03055-5

Efficient production of valinomycin by the soil bacterium, Streptomyces sp. ZJUT-IFE-354

3 Biotech. 2022 Jan;12(1):2. doi: 10.1007/s13205-021-03055-5. Epub 2021 Dec 2.

Authors

Dong Zhang^{1

2}, Zhi Ma^{1

2}, Hanchi Chen^{1

2}, Weilin Ma^{1

2}, Jiawei Zhou^{1

2}, Qing Wang^{1

2}, Chan Min^{1

2}, Yuele Lu^{1

2}, Xiaolong Chen^{1

2

3}

Affiliations

¹ Institute of Fermentation Engineering, Zhejiang University of Technology, Hangzhou, 310014 Zhejiang People's Republic of China.
² College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014 Zhejiang People's Republic of China.
³ Present Address: Zhejiang University of Technology, No. 18 Chaowang Road, Gongshu District, Hangzhou, 310014 Zhejiang People's Republic of China.

Abstract

A novel strain with antifungal activity against Sclerotinia sclerotiorum was isolated from soil, and identified as Streptomyces sp. ZJUT-IFE-354 using morphological and 16S rDNA sequence analysis. The bioactive metabolite produced by strain ZJUT-IFE-354 was identified and characterized as valinomycin by spectroscopic and chemical methods. The yield of valinomycin was 191.26 mg/L from the culture of Streptomyces sp. ZJUT-IFE-354, which was the highest yield to our knowledge. The in vitro antifungal activity of valinomycin against S. sclerotiorum was investigated as 0.056 ± 0.012 (EC₅₀) and 0.121 ± 0.023 μg/mL (EC₉₅), respectively, which was approximately 10.696- and 30.960-fold more active than that of carbendazim. The results from scanning electron microscopy, cell membrane permeability, and _D-sorbitol and ergosterol assay indicated that valinomycin exerted the antifungal activity probably by increasing permeability of fungal cell membrane, leading to mycelial electrolyte leakage, and eventually resulting in the death of S. sclerotiorum. Thus, valinomycin may be a promising antifungal agent to control S. sclerotiorum.

Supplementary information: The online version contains supplementary material available at 10.1007/s13205-021-03055-5.

Keywords: Antifungal activity; Antifungal mechanism; Sclerotinia sclerotiorum; Streptomyces; Valinomycin.