title: Optimization of the fermentation medium for alpha-galactosidase production from Aspergillus foetidus ZU-G1 using response surface methodology.
abstract: 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.
authors.affiliation: Dept. of Food Science and Nutrition, Zhejiang Univ., Hangzhou, 310029, China.
authors.forename: Caiquin
authors.initials: C
authors.lastname: Liu
authors.forename: Hui
authors.initials: H
authors.lastname: Ruan
authors.forename: Huafeng
authors.initials: H
authors.lastname: Shen
authors.forename: Qihe
authors.initials: Q
authors.lastname: Chen
authors.forename: Bing
authors.initials: B
authors.lastname: Zhou
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.forename: Guoqing
authors.initials: G
authors.lastname: He
mesh_terms: D001230:Aspergillus / Q000201:enzymology* / Q000254:growth & development*; D019149:Bioreactors; D002244:Carbon / Q000378:metabolism; D015169:Colony Count, Microbial; D003470:Culture Media / Q000737:chemistry*; D004043:Dietary Fiber / Q000378:metabolism; D004602:Elements; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology / Q000379:methods; D009584:Nitrogen / Q000378:metabolism; D013025:Glycine max / Q000378:metabolism; D013997:Time Factors; D000519:alpha-Galactosidase / Q000096:biosynthesis* / Q000737:chemistry
chemical_list: D003470:Culture Media; D004043:Dietary Fiber; D004602:Elements; D002244:Carbon; D000519:alpha-Galactosidase; D009584:Nitrogen