Halotolerant Streptomyces albidoflavus INA 01478 as a Producer of Daidzein: Genome Annotation, purification and Antifungal Activity

The strain INA 01478 has been isolated from the soil of bottom sediments of Trondheim Fjord, Norwegian Sea. This halotolerant strain is capable of producing the isoflavone daidzein in the culture medium. The preliminary genome analysis has identified homologs of genes involved in the de novo biosynthesis of daidzein in the genome of the strain. Structural elucidation, performed using 2D NMR and HR-ESIMS data, has identified the compound as daidzein. The absolute configurations of these stereoisomers have been determined through conformational NMR analysis and circular dichroism spectroscopy. The antifungal activity of daidzein has been detected against Candida albicans ATCC 2091, Saccharomyces cerevisiae INA 01042, opportunistic filamentous fungi Aspergillus niger ATCC 16404, and Fusarium oxysporum VKPM F-148.