Use of agroindustrial residues in biotechnological process by beta-galactosidase production from Kluyveromyces marxianus CCT 7082

Use of agroindustrial residues in biotechnological process by beta-galactosidase production from Kluyveromyces marxianus CCT 7082. The objective of this work was to evaluate the composition of the culture medium for the production of the enzyme beta-galactosidase from Kluyveromyces marxianus OCT 7082 using an experimental design. Enzyme production was carried out in a medium consisting of cheese whey, corn steep liquor (CSL) and Prodex-lac (R) yeast hydrolyzate. A factorial fractional design (2(5-1)) was performed to determine the significant variables in the production of the enzyme. Different concentrations of lactose present in whey (10-70 g L(-1)), CSL (10-100 g L(-1)), Prodex-lac (40-20 g L(-1)), (NH(4))(2)SO(4) (0-10 g L(-1)) and pH (5-7) were tested. Lactose concentration, CSL and pH were the variables that showed a statistically significant effect on enzyme activity within the ranges studied, and these variables were used in a central composite rotatable design to optimize production of the enzyme. The ranges used were: lactose concentration 40-100 g L(-1), CSL 10-120 g L(-1), and pH 3.5-6.5. The conditions that resulted in higher enzyme activity (1400 U g(-1)) were 70 g L(-1) lactose, 65 g L(-1) CSL, 4 g L(-1) Prodex-lac and pH 5, yielding 61 U L(-1) h(-1).33215516