Abstract: To prolong shelf life of the microbial formulation and improve its survival rate in the environment to ensure its efficacy,a complex coacervation was used to prepare Paecilomyces lilacinus and Trichoderma harzianum microcapsule formulation separately.In this study,taking conidial spores of T.harzianum and P.lilacinu as the core materials,gelatin and arabic gum as the wall materials,the optimal investment conditions of microcapsule were determined by response surface method.The encapsulation conditions for P.lilacinus microcapsules were 2.5% of gelatin and arabic gum (40 mL),respectively,as the wall materials solution,1× 10⁹cfu/mL spores,curing pH 4,curing temperature of 40℃,stirring speed of 500 r/min,the final encapsulated rate of (85.44± 0.22)%,and the median size of the encapsulated particles of 23.62 μm.The spore survival rate was 95.23% after 720 days of storage at 4℃.The encapsulation conditions for T.harzianum microcapsules were 1.6% of gelatin and arabic gum (40 mL),respectively,as the wall materials,1× 10⁹cfu/mL spores,curing pH 4.2,curing temperature of 40℃,stirring speed of 500 r/min,the final encapsulated rate of 92.17%,and the median size of the encapsulated particles of 27.19 μm.The survival rate at 25℃ was 92.11%.After 720 days storage at 4℃,the survival rate of spores was 96.25%.A combined formulation with T.harzianum and P.lilacinus microcapsules at the ratio of 6:4 was applied to an indoor in-vitro test to inhibit Physalospora piricola Nose.The results showed that the inhibition activity of the formulation reached 60.0%.

Key words: microcapsule, Paecilomyces lilacinus, Trichoderma harzianum, Physalospora piricola Nose