产共轭亚油酸瑞士乳杆菌L7固定化条件的研究.pdf

※生物工程 食品科学 2012, Vol.33, No.21 231 L7 朱义松，刘晓华，曹郁生* (南昌大学中德联合研究院，江西 南昌 330047) 摘 要： Lactobacillus helveticus c t 对瑞士乳杆菌( ) L7发酵生产 9, 11-CLA的固定化条件进行研究。应用响应面法对细 菌固定化的条件进行优化，得到的优化条件为：海藻酸钠质量浓度1.78g/100mL、氯化钙质量浓度3.13g/100mL、固 c t μ 定化时间60.30min，利用在此条件下制备所得的固定化胶珠发酵， 9, 11-CLA的产量达到561 g/mL 。固定化细胞重 c t μ 复利用5次后活力没有明显变化， 9, 11-CLA产量保持在549 g/mL 。电镜观察发现，固定化胶珠表面及内部为错综 复杂的网状通道结构，能够很好的满足物质的传递。结果表明菌体细胞经海藻酸钠固定，可以有效提高菌体的重复 c t 利用率，从而降低 9, 11-CLA的生产成本。 瑞士乳杆菌L7 ；固定化；生物转化；共轭亚油酸；响应面分析 Immobilization of Conjuated Linoeic Acid-Producing Lactobacillus helveticus L7 * ZHU Yi-song ，LIU Xiao-hua ，CAO Yu-sheng (Sino-German Joint Research Institute, Nanchang University, Nanchang 330047, China) Abstract ：Immobilized Lactobacillus helveticus L7 was used for biosynthesizing c9,t 11-CLA from linoleic acid. The immobilization conditions were optimized by response surface methodology. The optimal conditions for the preparation of immobilized cells required 1.78 g/100 mL sodium alginate, 3.13 g/100 mL calcium chloride and 30 min immobilization time. The fermentation of immobilized cells under the optimal conditions could result in the highest accumulation of c9,t11- CLA up to 561 μg/mL. Meanwhile, the immobilized strain displayed good transformation properties. No obvious change in the activity of the immobilized strain was observed after reuse for fi ve times, and the yield o