南极假丝酵母脂肪酶发酵条件优化及酶学性质

分别用摇瓶和15L发酵罐,对南极假丝酵母产胞外脂肪酶的培养基成分和操作条件进行了实验研究。得到最优的培养基组成为:豆粉40g／L,淀粉15g／L,豆油5mL／L,K2HPO4g／L,MgsO4·7H2O1g／L,Tween-800.1％,酵母膏5g／L;操作条件为:温度24℃,初始pH值为6.0,通气量为10.0L／min。在此培养条件下,发酵周期缩短至54h。由15L发酵罐生产的酶液酶活达到19.2U／mL。酶液在pH值为4.0～6.0和7.5～9.0范围内较稳定,其最适宜pH值范围为6～8.5;70℃时酶的催化活性最大.在40～70℃的温度范围内保持1h后残留酶活为60％。

Fermentation process optimization and enzymology properties research for lipase production by Candida Antarctica

The nutrient medium composition and operation conditions for producing extracellular lipase from Candida Antarctica are studied in both shake-flask and 15 L fermenter. The optimal nutrient medium contains soybean meal 40 g/L, starch 15 g/L, soybean oil 5 mL/L, K2HPO4 4 g/L, MgSO4 .7H2() 1 g/L, Tween-80 0. 1%, yeast extract 5 g/L. The optimal operation conditions are as follows; temperature 24 C , initial pH 6. 0, airflow rate 10. 0 L/min. Under the optimal conditions, the period of fermentation reduces to 54 h. The maximum lipase activity of 19. 6 U/mL is achieved in 15 L fermenter. The lipase is stable in pH ranges of 4. 0-6. 0 and 7. 5-9. 0 and has an optimal activity at pH range of 6-8. 5. The lipase has the highest activity at 70℃ and is stable in range of 40-70℃ with more than 60% activity remaining after exposure of 1 h.