Research On The Pesticide Activity And Antimicrobial Mechanism Of Tetrahydrofuran Compounds Produced By Marine Microorganisms

Marine microorganisms take an important role in the development of Marine drugs,and there are abundant resources of bioactive substances produced during its metabolic processes.It has important application prospect to find and discover new pesticide compounds.A system study of pesticide potential of marine microorganism was conducted in this experiment.The results were as follows:1150marine strains were screened,gaining12stains with high antimicrobial activity.The12strains fermentation extracts were used on plants living test as after screening. The results showed that the control effect of the strain RH-07to the cucumber powdery mildew and gray mold is more outstanding.Treated by RH-07bacteria and fungus20times crude extract liquid,the control effect to cucumber powdery mildew was63.7%and63.7%respectively,while the results of gray mold was85%. The strain RH-07was chosen as an inhibitory strain for the next experiment.2The method of ingle UV mutation、UV+LiCl mutation and nitrite mutation was applied to mutate the strain RH-07.The strain2L-5U-1with high inhibitory activity and stability was gained during the screening of Alternaria solani model. And its inhibitory activity is twice of the starting strain.3The control efficiency of2L-5U-1fermentation extract to cucumber powdery mildew on potted plant was researched.The results showed that the inhibitory effects of50times dilution of2L-5U-1thallus and microbial crude extract were80.17%and66.7%respectively,which is increased by29.24%and7.53%with the contrast chemical triadimeton.Field control efficacy of the strain2L-5U-1fermentation broth against tomato powdery mildew was tested.The results showed that its control efficacy was68.88%,which is increased by12.84%with the contrast chemical triadimeton.4Treated by RH-07fermentation extract,the conductivity and total protein content of Fulria fulva thallus increased,while the SDHase decreased.The results also showed that some protein bands increased according to the SDS-PAGE patten.These can be explained as the membrane permeability was damaged,the protein metabolic procedure was unbalanced,and the respiratory action was inhibited.