Study On Secondary Metabolites And Biological Activiities Of Two Marine Fungi

The problems of food safety and drug resistance or resistance caused by the extensive use of pesticides.All these problems seriously damaged the environmental quality and destroyed the ecological balance.Therefore,marine microbes are quickly become as the research object and were utilized them efficiently,in order to develop green,easy degradation and high-efficiency natural pesticides.In this paper,two strains were mainly subjected to fermentation,and the activity tracking technology was used for separation and purification for further study.Firstly,marine endophytic fungi were isolated and purified from marine organisms such as algae,crabs and oysters collected in Qingdao sea area,and 5 marine fungi strains were obtained.Then 4W optimized culture and activity screening,2 dominant strains D and E were obtained: the product content in RICE medium was the largest.The TLC plate assay found that the secondary metabolites in the MH1 and RICE media were abundant,and the metabolites of the E strain contained special substances showing red and yellow spots;the metabolites obtained from the MH1 medium have certain antibacterial activity against B.subtilis and S.aureus.Molecular biological identification of strains D and E were Trichoderma koningiopsis(abbreviated as TK)and Fusarium tricinctum(abbreviated as FT).The strains TK and FT were scaled and the activity tracking showed that the Fr3-Fr9 component of the strain TK and the Fr6-Fr7 component of the strain FT had strong antibacterial activity.The components were separated and purified by preparative plate thin layer chromatography(PTLC),recrystallization and various column chromatography methods,obtaining more than 30 monomeric compounds,and the antibacterial activity of some monomeric compounds was studied.The results showed that the compound FT-12 had a strong inhibitory effect on B.subtilis,and the diameter of the inhibition zone was 20 mm(34 mm for the positive control);FT-18 showed strong antibacterial activity against E.coli,the diameter of the inhibition zone was 19mm(33mm for the positive control);FT-26 showed strong antibacterial activity against 6 indicator bacteria(B.subtilis,B.thuringiensis,E.coli,S.aureus,P.aeruginosa,X.campestris),and the diameter of the inhibition zone was 14mm~ 30 mm,which is the main active substance component of Fr8.It is worthy of further study.