壳聚糖/海藻酸钙微胶囊制备工艺对地衣芽胞杆菌生长的影响

Effects of Preparation Conditions of Alginate/Chitosan Microcapsule on Viability Characteristics of Bacillus licheniformis

针对地衣芽孢杆菌微囊化发酵生产生物药物杆菌肽的研究背景,以壳聚糖、海藻酸钠为微载体制备材料,地衣芽孢杆菌为细胞模型,采用脉冲电场液滴工艺制备载细胞壳聚糖/海藻酸钙微胶囊(AC微胶囊),系统考察了壳聚糖分子量与浓度、固定化载体类型、微胶囊粒径和接种密度等工艺条件对微囊化地衣芽孢杆菌培养特性的影响。结果表明:与海藻酸钙凝胶珠相比,AC微胶囊表面囊膜具有良好的物质选择性透过作用,地衣芽孢杆菌在微胶囊内正常生长且未从囊中泄漏,在72h培养过程中微胶囊形态完整;培养系统组分在微胶囊中传递速率与微胶囊粒径成反比,固定化细胞的相对生长量随微胶囊粒径减小而增大;在2.1×106个/mL的初始接种密度条件下,培养过程中微胶囊形态最佳;固定化细胞达到最大生长量所需时间与壳聚糖分子量成反比,其中,10万分子量壳聚糖样品所需时间为9 h,并在随后72 h培养过程中保持稳定生长。

Using chitosan and sodium alginate as the micro-carrier preparation materials, the calcium-alginate- chitosan（AC） microcapsule were prepared by the impulsive electrostatic preparation process. In this paper, viability characteristics of B. licheniformis immobilized in calcium alginate-chitosan microcapsule under different preparation conditions are investigated. with alginate-Ca gel beads, produced immobilized cells The results showed that B. AC microcapsule was more a steady microenvironment licheniformis grown well in the AC microcapsule. Compared suitable for cell cultivation owing to the chitosan membrane Large diameter microcapsule could inhibit the diffusion of nutrition thereby the concentration of cells immobilized would be decreased. One time initial inoculation amounts should be optimum amount in microcapsule preparation process. Molecular weight of chitosan brought an evident effect on log phase of growth curvature. The longest phase was produced by 20 thousand Dalton molecular weight of chitosan, followed by 50 thousand, and 100 thousand obtained the shortest log phase, which is only about 9 hours. Generally speaking, AC microcapsule maintained its shape in a good condition and fine stability during the entire cultivation.