Bt杀虫晶体蛋白—肠溶性微囊制备方法的初步研究

Elementary studies on the preparation technology of enteric microcapsule of insecticidal crystal proteins from Bacillus thuringensis by orthogonal matrix method

【目的】研究Bt(Bacillus thuringensis)晶体蛋白肠溶性微囊的制备方法,为进一步研究它对防止紫外线损伤晶体蛋白及促进晶体蛋白在害虫中肠快速释放等方面的作用奠定基础;【方法】用复相乳液法制备肠溶性微囊,并应用L16(45)正交试验设计研究相关因子对微胶囊包封率的影响;【结论】采用复相乳液法可以制备Bt晶体蛋白的肠溶性微囊。5个因子对包封率有显著影响,影响大小依次为乳化转速>HPMCP浓度(壁材)>Bt晶体蛋白含量(芯材)>蓖麻油含量(助剂)>甲基纤维素浓度(亲水胶体)。以500ml分散系为条件,筛选出的肠溶性微胶囊较佳工艺为:8.6mg/mLBt晶体蛋白溶液1ml,20mg/mL HPMCP溶液50ml及蓖麻油2ml,三者混合并在匀化器转速6000r/min下乳化,而后分散于2.1%或3.3%甲基纤维素钠溶液中成囊。

[OBJECTIVE]The paper aimed to research the preparation technology of enteric microcapsules of insecticidal crystal proteins （ICP） of Bacillus thuringensis （Bt）. [Method] Double emulsion method was used for the effort to prepare enteric mieroeapsules with ICP as core material and hydroxypropyl methylcellulose phthalate （HPMCP） as shell material. Experiment in orthogonal matrix design [L16（4^5）] was used to value the influence of the relevant elements.[Results]Enterie microcapsules wrapping ICP could be prepared by double emulsion method. The encapsulation of ICP was influenced by factors such as emulsification rotation speed, concentration of shell and core materials, emulsification agent and hydrocolloids, which were listed in a pattern of decreasing importance. In 500 ml aqueous medium for formation of the microcapsules, the opti- mal technology was to emulsify 1 ml 8.6mg/mL IPC, 50ml 20mg/mL HPMCP and 2 ml castor oil at emulsification rotation speed of 6000 r/min, then disperse the emulsion in 2.1% or 3.3% carboxymethyl cellulose （CMC-Na）.