Optimisation of the medium composition for production of protease and soybean peptides by Bacillus subtilis SHZ using response surface methodology

Autor: Fengxia Lu, Bo Yu, Zhaoxin Lu, Xiaomei Bie, Xian-Qing Huang
Rok vydání: 2008
Předmět:
Zdroj: International Journal of Food Science & Technology. 43:1143-1151
ISSN: 1365-2621
0950-5423
DOI: 10.1111/j.1365-2621.2007.01580.x
Popis: Responses surface methodology was employed to enhance the production of protease and soybean peptides by Bacillus subtilis SHZ. For screening of medium composition significantly influencing protease and soybean peptides yield, the two-level Plackett-Burman design was used. Among thirteen variables tested; KH 2 PO 4 , glucose and defatted soybean flour (DSF) were selected based on their high significant effect on both protease activity and soybean peptides yield. Then, a three-level Box-Behnken design was employed to optimise the medium composition for the production of the protease and soybean peptides in submerged fermentation. Mathematical models were then developed to show the effect of each medium composition and their interactions on the production of protease and soybean peptides. The model estimated that, the maximal protease activity (320 ± 1 U mL -1 ) could be obtained when the concentrations of glucose, KH 2 PO 4 , DSF were set at 8-9 g L -1 , 2-3 g L -1 , 55-65 g L -1 $, respectively; while a maximal yield of soybean peptides (8.5 ± 0.1 g L -1 ) could be achieved when the concentrations of glucose, KH 2 PO 4 , DSF were set at 7-9 g L -1 , 3-4 g L -1 and 55-58 g L -1 , respectively. These predicted values were also verified by validation experiments.
Databáze: OpenAIRE
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