Study On The Bio-Active Substances Of Endophytic Fungi CCH-1 In Seaweed

In order to increase crop yields,both at home and abroad a large number of efficient use of pesticides to control pests and diseases.However,followed by environmental pollution,ecological imbalance,food safety and other issues,in the long-term extensive use of pesticides in the process,many agricultural diseases and insect pests gradually produce different degrees of resistance and drug resistance.The environment-friendly pesticide developed with natural products as the lead compound has the advantages of easy degradation,high selectivity and environmental friendliness,and has gradually become one of the main ways of new green pesticide research and development.New research on the metabolites of marine fungi is of great significance to the discovery of novel structures and environmentally friendly agricultural antimicrobial substances.The results showed that the strain CCH-1 was a "peculiar" strain in terms of the growth morphology,the quality of the secondary metabolites,the richness and the antibacterial activity of the four strains.In addition to CCH-1,the amount of secondary metabolites of the other three strains was relatively large,especially RICE solid culture medium.The different medium of the same fermentation time of strain CCH-1 was RICE solid medium Secondary metabolites were larger,MH1 times.The secondary metabolites of CCH-1,CCH-2 and 27-A were found to be abundant by TLC,but the crude extract of CCH-1 MH1 medium had the characteristics of color Spots,growth looks strange.In the antibacterial activity screening,it was found that the antibacterial activity of the strain CCH-1 was the best,the maximum inhibition zone was 23mm(positive control was 23mm);the CCH-2 and 24-A strains had better antibacterial activity against BS The positive inhibitory activity was 22 mm and 26mm(24mm positive control),27-A had good antibacterial activity against BT,and the maximum inhibitory activity was 24mm(positive control was 22mm).The final determination of CCH-1 as a research object,take 4w of standing fermentation.The MH1 medium of strain CCH-1 was fermented three times,At the same time,in order to investigate the interaction between homologous microorganisms,CCH-1 and CCH-3 from Brassica campestris were mixed and fermented.The resulting extract was subjected to VLC gradient elution and activity was tracked.It was found that the petroleum ether: Ethyl acetate was 10: 1(V: V)to dichloromethane: methanol was 5: 1(V: V)Strong activity,the product is more abundant,the components were separated and purified using recrystallization and various column chromatography such as silica gel column,gel column,reverse phase column and preparative plate thin layer chromatography,and finally more than 20 compounds were obtained.Five compounds were identified by modern spectroscopy NMR and literature comparison.The results showed that the monomeric compounds FT-32 and FT-33 had strong antibacterial activity against BS,the diameter of inhibition zone was 40 mm and 44 mm,respectively(positive control was 32mm).