Inducement And Production Of Antibacterial Substances In Spodostera Exigua Huber, Tenebrio Molitor, Enpolyphaga Sinensis Walker And Their Antibacterial Activity

Insecs had highly effective chemical defensense system. In this paper, antibacterial substances were acquired from Spodostera exigua Hubner , Tenebrio molitor and Enpolyphaga sinensis Walker. Two kinds of antibacterial substances were extracted from Spodostera exigua Hubner and Enpolyphaga sinensis Walker at the first time. Induction, isolation, antibacterial acticity and antibacterial mechanism of antibacterial substances of three insects were studied.Antibacterial activity of three insects treated by pricking with E.coli, pricking with pesticide, ultrasonic wave and starve were induced .The results show that the method of pricking with E.coli was the prima.Those antibacterial substances had high stability. Low temprature, ultraviolet radiation didn't affect the activity greatly. The activity didn't decreased in the -20℃ for 1 day. The activity first decreased, then increased and decreased with increase of exposure in ultraviolet radiation.Their activity were best in ultraviolet radiation for 15min-30min. Their activity canbe kept in pH5-9. The activity didn't decreased in the 25℃ for 72h. The concentration of ammonium acetate could affect the activity. The activity could decrease in 4mol.L^-1 of ammonium acetate.These three antibacterial substances all had wide spectrum and had strong inhitory activity against germs and fungi. They could inhibit two kinds of animal germs, two kinds of plant pathogemic germs and seven kinds of plant pathogenic fungi.The fungi couldn't grow after treated by antibacterial substances.The number of germs first decreased, then increased with the increase of time. It showed the mechanism of these antibacterial substances are bacterial action.After Tricine-SDS-PAGE, it showed these molecular weight of antibacterialsubstances were about 10 to 40KD. The results showed that these antibacterial substances are antibacterial peptides. In Tricine-SDS-PAGE, it also showed different induction methods could induce antibacterial peptides.The paper gives a foundation to further research on antibacterial peptides of Spodostera exigua Hubner ,Tenebrio molitorJLnpolyphaga sinensis Walker.