Abstract:

The purpose of this research was to control Tobacco wildfire disease by biological ways. It was determined the fermented liquid and sterile filtrate of Tpb55 strains to the inhibitory effect of tobacco wildfire germs by Filter method and Oxford cup method. It was determined the physical and chemical properties of the antibacterial material produced by Tpb55, such as thermal stability, acid-base stability and light stability by water bath heating, adjust pH, ultraviolet and sunlight sterile filtrate. The results showed that the bioactive metabolite had good inhibition ability to P. syringae pv. Tabaci. Filter paper determination method of the antibacterial circle diameter is 6.04 cm, and the agar diffusion determination method for it is 2.52 cm; Fermentation liquid on pH 3 to 8 keep higher activity, taking the neutral pH condition is the best and most stable; Light stability test result indicates that antimicrobial substances of Tpb55 strains produced against ultraviolet light has good stability, which continuous UV illumination 9 hours, and the bacteriostatic activity decreased not more than 16%. Therefore, Tpb55 is a bio-controlling strain with high potential value .This study provides effective component for further separation, purification of the fermentation liquor, and a research foundation for its further development.