Modification of artificial sea water for the mass production of (+)‐terrein by Aspergillus terreus strain PF26 derived from marine sponge Phakellia fusca

(+)‐Terrein shows multiple bioactivities, however, its mass production is a big challenge. Aspergillus terreus strain PF26 derived from South China Sea sponge Phakellia fusca has been cultured to produce (+)‐terrein successfully, but artificial sea water (ASW) of high salinity used in the fermentation medium may cause the corrosion risk of metal bioreactor, which limits the fermentation on a large scale. In this study, we modified the components of ASW by removing NaCl and CaCl₂ from the original formula, which reduced about 80% salinity of ASW. As a result, 7·56 g l⁻¹ (+)‐terrein production was achieved in shake flask, which was 78·72% higher than using the original ASW, and the cultivation time was decreased from 24 to 15 days. Then, the modified ASW was used for the fermentation of A. terreus strain PF26 in a 500 l stirred bioreactor, consequently 2·5 g l⁻¹ of (+)‐terrein production was achieved. SIGNIFICANCE AND IMPACT OF THE STUDY: The fermentation of marine micro‐organisms always needs to use sea water or artificial sea water (ASW), which limits the fermentation on a large scale, as the high‐salinity medium may cause the corrosion risk of bioreactor. In this study, the ASW formula is simplified to reduce the sea water salinity and improve the yield of (+)‐terrein, finally, the modified ASW was successfully used for the mass production of (+)‐terrein by A. terreus strain PF26 in a 500 l bioreactor.