Effects of salt concentration on the production of cytotoxic geodin from marine-derived fungus Aspergillus sp.

Abstract

Microorganisms produce optically single bioactive natural products; the process is cheap as compared to chemical synthesis and environmentally friendly. Geodin 1 was isolated from the soft coral-derived fungus Aspergillus sp. It has a broad range of biological activities such as antiviral, antimicrobial, glucose stimulator for rat adipocytes, enhancement of fibrinolytic and cytotoxic activities, and is a subunit of the first nonpeptide and inhibitory active galanin receptor. In this work, we studied the effects of sodium chloride (NaCl) salt concentration on the production of geodin 1 and improved its yield to a multi-gram quantity through media optimization from a marine-derived fungus Aspergillus sp. The fungal strain was cultivated at various concentrations of NaCl salt in rice medium and extracted after different intervals of time. The yield of geodin 1 was 137.2 mg/L at optimal conditions. The optimal conditions for the high yield of geodin 1 were found as rice medium with 2.0% NaCl salt and 3 weeks incubation at room temperature. The concentration of NaCl salt greatly affects the yield of geodin and hence its biosynthetic pathway.