[Secondary metabolites of the co-culture of Aspergillus sp. SCSGAF 0076 and Bacillus sp. MNMCCE 001].

OBJECTIVE

To elucidate the chemical structures of the main antibacterial compound and red pigment produced by the co-culture of marine-derived fungus Aspergillus sp. SCSGAF 0076 and bacterium Bacillus sp. MNMCCE 001.

METHODS

The monoculture of strain SCSGAF 0076 and co-culture of strains SCSGAF 0076 and MNMCCE 001 were done on amylum solid medium for three days, then the crude extracts of the cultures were obtained, and subsequently, the chemical profiles of the extracts of monoculture and co-culture were analyzed by HPLC. Using antibacterial bioassay-guided fractionation, we isolated the crude extract of the co-culture by silica gel column chromatogram, Sephadex LH-20, and semi-preparative HPLC to obtain the main antibacterial compound and red pigment. The compounds' structures were determined by spectroscopic analysis.

RESULTS

We found that the main secondary metabolites produced by the monoculture of strain SCSGAF 0076 and co-culture of strains SCSGAF 0076 and MNMCCE 001 were almost the same, however, the contents of the main antibacterial compound and red pigment were obviously different. Totally, four compounds including the antibacterial compound penicillic acid, 5 (6) -dihydropenicillic acid, 9-chloro-8-hydroxy-8,9-deoxyasperlactone and red pigment viopurpurin were isolated from the crude extract of the co-culture medium.

CONCLUSION

The main antibacterial compound of the co-culture of strains SCSGAF 0076 and MNMCCE 001 was penicillic acid, the main red pigment was viopurpurin, and the yields of the two compounds were proved by the co-culture.