Study On Separation And Purification Of Zwittermicin A And Its Stability

Research on the condition of Separation and Purification of Zwittermicin A , and establish a new way to get it. Zwittermicin A was purified from supernatants of Bacillus thuringiensis.subsp.kurstaki strain D1-23 cultivation. Zwittermicin A attenuation equation y=ke^bx is established through the temperature and pH stability experiments. Research on the Zwittermicin A protection matter and Synergy Between Zwittermicin A and Bt powder experiments are conducted.First Bacillus thuringiensis.subsp.kurstaki strain D1-23 cultivation is filtered to remove the microbiology.and get supernatants, then remove big molecule by filter membrane. Zwittermicin A is adsorbed by resin D113, then first washed by NH₄H₂PO₄ and next by different pH CH₃COONH₄. Then washed by NH₄OH , the liqiu is vaporized. 2.89mg pure Zwittermicin A was acquired by HPLC-MS. Results show that the optimized wash concentration of NH₄H₂PO₄ is 5mmol/L at first step.Next step CH₃COONH₄ concentration is 30 mmol/L, the gradient pH is 8.0～ 9.5 .Totally 93% Zwittermicin A can be reserved with ion exchange resin.The model Zwittermicin A attenuation equation y=ke^bx is established through temperature and pH stability experiments. The model is reliable (all R²>0.97), and application range is extensive. It include 20°C～100°C ,pH2.0～pH 12.0 extent. The temperature and pH stability experiments show that the temperature is more high the half life of Zwittermicin A is more short, prove that Zwittermicin A is sensitive to temperature. And pH stability experiments indicate that the lower pH can make Zwittermicin A more stability.The spraying dry results show that 160°C and 170°C have same effect on Zwittermicin A, but if exceed 170°C, Zwittermicin A lose fast.Because the high temperature can fast reduce water, and it is good to conserve the powder, so the proper temperature is 170°C.Zwittermicin A protection matter research show that Ca²⁺and Ba²+)can not protect supernatants , but can protect the fermentation.VC has negative result.The proper concentration of Ca²⁺ is 1%, the proper concentration of Ba²⁺ is 1.5%.Synergy Between Zwittermicin A and Bacillus thuringiensis subsp.kurstaki Against Laphygma exigua Hubner and Helicoverpa armigera results show that Zwittermicin A can enhance activity of Bt power against Laphygma exigua Hubner 4.88 fold. Can enhance activity of Bt power against Helicoverpa armigera 3.79 fold.The effect to Laphygma exigua Hubner is better than to Helicoverpa armigera.