Optimization of the Culture Medium for the Production of β-Galactosidase from Kluyveromyces marxianus CCT 7082

Abstract

Seven strains of the genus Kluyveromyces were screened for β-galactosidase activity in a synthetic medium. Kluyveromyces marxianus CCT 7082 was selected as the best enzyme producer for optimization of the culture medium. A fractional factorial design 2^(4-1) was used to determine the most relevant variables of the culture medium composition for the enzyme production. The parameters studied were the concentrations of lactose, yeast extract and (NH4)2SO4 as well as pH, and all were shown to have significant effects on the production of the enzyme. Based on the results from the first factorial design, lactose, yeast extract and (NH4)2SO4 concentrations were selected to be utilized in a 2³ central composite rotatable design (CCRD). This led to a further optimization of the fermentation conditions to achieve higher enzyme activities, which reached 10.6 U/mL.

Keywords

• β-galactosidase
• Kluyveromyces marxianus
• optimization
• factorial design
• response surface methodology