Liu Caiquin, Ruan Hui, Shen Huafeng, Chen Qihe, Zhou Bing, Li Yi, He Guoqing
Dept. of Food Science and Nutrition, Zhejiang Univ., Hangzhou, 310029, China.
J Food Sci. 2007 May;72(4):M120-5. doi: 10.1111/j.1750-3841.2007.00328.x.
The optimization of fermentation medium for alpha-galactosidase production by Aspergillus foetidus ZU-G1 was investigated in shaker flask fermentation. A one-factor-at-a-time experiment was used to screen the preferable nutriment (carbon sources, nitrogen sources, and essential elements) for alpha-galactosidase production. A fractional factorial design was used to screen the main 5 factors, soybean meal, wheat bran, KH2PO4, FeSO4 x 7 H2O, and the medium initial pH, that affected the production of alpha-galactosidase. The central composite experimental design was further adopted to derive a statistical model for optimizing the composition of the fermentation medium. The experimental results showed that the optimum fermentation medium for alpha-galactosidase production by Aspergillus foetidus ZU-G1 was composed of 3.2% soybean meal (w/v), 2% wheat bran (w/v), 0.1% KH2PO4 (w/v), and 0.05% FeSO4 x 7 H2O (w/v); initial medium pH was 6.31. The results further predicted that alpha-galactosidase activity reached 64.75 U/mL after 96-h incubation in this medium, which was approximately 7 times higher than that incubated in the nonoptimized medium. The time course of alpha-galactosidase production in the optimized medium composition was also carried out to validate the model.
在摇瓶发酵中研究了恶臭曲霉ZU-G1产α-半乳糖苷酶发酵培养基的优化。采用单因素实验筛选产α-半乳糖苷酶的最佳营养物质（碳源、氮源和必需元素）。采用分式析因设计筛选影响α-半乳糖苷酶产量的5个主要因素，即豆粕、麦麸、KH2PO4、FeSO4·7H2O和培养基初始pH。进一步采用中心复合实验设计推导用于优化发酵培养基组成的统计模型。实验结果表明，恶臭曲霉ZU-G1产α-半乳糖苷酶的最佳发酵培养基组成为3.2%豆粕（w/v）、2%麦麸（w/v）、0.1%KH2PO4（w/v）和0.05%FeSO4·7H2O（w/v）；培养基初始pH为6.31。结果进一步预测，在此培养基中培养96小时后，α-半乳糖苷酶活性达到64.75 U/mL，约为在未优化培养基中培养的7倍。还进行了优化培养基组成中产α-半乳糖苷酶的时间进程实验以验证该模型。
