产柚苷酶黑曲霉SL2K发酵条件优化

Optimization of fermentation conditions for naringinase production by Aspergillus niger SL2K

该研究以黑曲霉(Aspergillus niger)SL2K为研究对象,对其产柚苷酶的液态发酵条件进行优化。通过单因素试验对碳源、氮源、诱导物、接种量、初始pH值和培养时间进行考查,在单因素基础上,选取麸皮粉添加量、蛋白胨添加量、接种量、初始pH值4个因素进行4水平正交试验优化。结果表明,优化后的产酶发酵条件为麸皮粉添加量3%,蛋白胨添加量5%,接种量8%,初始pH值为5.0,鼠李糖0.08%、KH_2PO_41 g/L,KCl 0.5 g/L,MgSO_4·7H_2O 0.5 g/L,FeSO_40.01 g/L,装液量为100 m L/250 m L,摇床转速180 r/min,培养温度28℃,培养时间96 h。在此优化条件下,柚苷酶活力为233.89 U/m L,是优化前的2.13倍。

Using Aspergillus niger SL2 K as research object, the fermentation conditions for naringinase production by A. niger SL2 K were optimized by single factor and orthogonal experiments. Firstly, the effects of carbon source, nitrogen source, inducer, inoculum, and initial pH value of medium and culture time on the naringinase yield were studied by single factor experiments. On that basis, four factors（bran addition, peptone addition, inoculum, initial pH value） of fermentation conditions were optimized through the orthogonal experiments with 4 levels. The optimal enzyme producing conditions were as follows： wheat bran powder 3%, peptone 5%, inoculum 8%, initial pH value 5.0, rhamnose 0.08%, KH2PO41 g/L, KCl0.5 g/L, MgSO4·7 H2O 0.5 g/L, FeSO40.01 g/L, liquid volume 100 ml/250 ml, rotation speed 180 r/min, culture temperature 28 ℃ and time 96 h. Under these conditions, the activity of naringinase was 233.89 U/ml, which was 2.13 times of before optimization.