Effect of salinity on the growth, biological activity and secondary metabolites of some marine fungi

The study investigated the effects of salinity on growth, antimicrobial activities and secondary metabolites of 47 marine filamentous fungi isolated from the East China Sea near the western shore of the Taiwan Straits. The results indicate that NaCl promoted the growth up to 91.5% of test strains. However, only 14.9% of them showed a significant increase of antimicrobial activity against Candida albicans. When incubated in different concentrations of NaCl, the colony growth, antimicrobial activities and composition of secondary metabolites of the strain Ty01b-8 of Penicillium sp. varied. Treatment with KCl also showed a similar effect. An alkaloid isolated from the fermentation broth of Ty01b-8 was identified as chrysogine, inhibition activity of which against Hela cells was 15.05% at 20 µg/ml, and yield was 4.4 and 4.9 times higher in 3 percent and 6 percent NaCl treatments, respectively, compared with the non-salt culture condition. These findings prove that salinity is an important factor influencing growth and secondary metabolites of some marine fungi, which can be used to screen for new metabolites from marine fungi, and to enhance their metabolites production in industrial fermentation.