Process optimization and performance evaluation of B.t.microcapsule prepared by spray drying
[Aims]To ensure the storage stability and stress resistance of Bacillus thuringiensis(B.t.)formulations,fully utilize their insecticidal effect,and extend their field survival capacity,B.t.microcapsules were prepared.[Methods]B.t.(B-Y7-1)microcapsules were prepared by using spray drying technology.Through single factor screening and orthogonal optimization tests,the best preparation process of spray drying method was determined,and its performance and activity were characterized and evaluated.[Results]The best process of spray drying was:3％of sodium alginate as wall material,inlet temperature of 180 ℃,material flow rate of 14 mL/min,with the microcapsule yield of 76.45％±1.35％and the viable rate of 93.11％±2.03％.After 14 d of thermal storage at 54 ℃,the survival rate of spores in the microcapsules prepared by spray drying method was 71.23％,which was much higher than that of B.t.powder(8.08％).The release of B.t.microcapsules in water followed a first-order kinetic model,while in soil it followed the Ritger-Peppas model and belongs to Fick diffusion.The biological activity test showed that the sustained insecticidal effect of B.t.microcapsules on white grubs was higher than that of non-embedded B.t.bacterial solution.[Conclusions]The results indicated that B.t.microcapsule can improve its stability and has sustained-release properties.
NETL
NSTL
万方数据
