固定化柱状假丝酵母产酶条件优化

Conditions Optimization of a Candida Cylindracea Immobilized in PUF for Lipase Production

以市售聚氨酯泡沫为载体,考察载体预处理方式、载体尺寸、载体投放量、摇床转速对柱状假丝酵母细胞固定及产酶的影响,确定固定化的最优条件,并考察酵母细胞固着稳定性。在相同条件下与游离发酵进行对比。研究结果表明最有效的处理方式为先用1%(质量分数)NaOH溶液处理24h,再用1%(质量分数)HCl溶液处理24h;载体的最佳尺寸为2.0cm×2.0cm×0.5cm;在150r/min下获得的固着态细胞多,发酵液酶活高;从发酵液酶活和试验成本两方面考虑,确定向150mL培养基中投放12块尺寸为2.0cm×2.0cm×0.5cm的载体为最佳。固定化细胞经水洗6次后,载体内的固着态细胞干重为水洗前的42.1%;固定化细胞发酵的细胞干重和发酵液酶活均比游离细胞发酵高,其中,前者总细胞干重是后者的2倍多,酶活是后者的1.6倍,达到19.67U/mL。固定化细胞发酵无论是在总生物量上,还是在发酵液酶活上,均保持一定的优势。

With commercial polyurethane foam as a carrier, the impact of its pre-treatment, sizes, quantity as well as the rotation speed on cell immobilization and lipase production were investigated. Look for the Optimal conditions of Immobilized and investigate its stability, compared to the free cell fermentation under the the same conditions The results indicated that the most effective treatment was first with 1% Mass fraction NaOH solution treatment for 24 h, and then 1% Mass fraction HC1 treatment for 24 h; the best carrier size was 2.0 cm×2.0 cm×0.5 cm; We obtained more immobilized cells and higher lipase activity under 150 r/min in this trial; Considering the cost of test and fermentation activity, We decided to put 12 carriers which size is 2.0 cm×2.0 cm×0.5 cm in 150 mL. after Immobilized cells were washed 6 times, the dry cell weight in the carrier was 42.1% of the pre-washed state. Compared with free cell fermentation, Immobilized cell fermentation achieves the higher total biomass and lipase activity,the former total biomass is twice than the latter and the lipase activity is 1.6 times, achieving 19.67 U/mL. Immobilized cell fermentation maintains a certain advantage either in total biomass, or in the lipase activity of the fermentation broth.