Abstract:

A uniform design involving 30 experiments of 6 variables at 10 levels was applied to optimize the fermentation medium composition of Arthrobacter sp.10138 for high activity of β-fructofuranosidase. The experimental data were analyzed by stepwise regression to obtain a quadratic polynomial regression model for predicting β-fructofuranosidase activity as a function of 6 variables. The optimal medium composition was as following: sucrose 5 g/L, beef extract 30 g/L, yeast extract 2 g/L, (NH4)2HPO4 10 g/L, KH2PO4 0.5 g/L and MgSO4·7H2O 0.2 g/L. Under these conditions, the predicted maximum β -fructofuranosidase activity was 382.92 U/ml, which was in close agreement with the actual experimental value of 365.85 U/ml.

Key words: β-fructofuranosidase, lactosucrose, uniform design method, medium optimization