Optimization of fermentation technology for production of fructosyltransferase with Aspergillus oryzae using CCD response surface methods

In order to produce fructosyltransferase in large scale,it is necessary to study and optimize the process conditions of Aspergillus oryzae strains fermentation. Using sucrose,soybean meal powder and corn flour as the basic medium for fructosyltransferase synthesis in the cells,three significant factors that affect the fermentation course were selected through the Plackett- Burman optimization experiment.With analysis of the central composite design( CCD) response surface methods,the fermentation process has been further optimized and the results showed that: there were interactions between the concentration of sucrose,soybean meal powder and the rotation speed.The interaction between the concentration of soybean meal powder and the rotation speed was mainly significant.The best technical parameters were obtained as followed: the concentration of sucrose was 5.95%,the concentration of soybean meal powder was 1.60%,and the rotation speed was 165 r / min. Under the optimal condition of fermentation,the enzyme activity of fructosyltransferase produced by fusion strain Aspergillus oryzae RIII-7 reached 870.21 U / g.It is close to the predictive value of 895.68 U / g,with an error of 0.028.