Optimization of a whey containing medium for β-galactosidase production by Lactobacillus reuteri

Abstract

Lactobacillus reuteri MF2-2 was screened out for producing a high level of β-galactosidase from chicken fecal samples and identified with 16S rRNA gene sequence analysis. To reduce production cost, a new whey containing medium was formulated on the basis of MRS medium and optimized. Nutrients including whey, yeast extract, NH4H2PO4, and vitamin B1 were investigated at the individual and interactive level by the Taguchi orthogonal tests. The production of β-galactosidase was improved from 490.0 U/g in lactose-based MRS (L-MRS) medium to 814.6 U/g in the optimized whey-based MRS (W-MRS) medium. W-MRS medium did not comprise of lactose, peptone, and beef extract and was expected to cut the raw material cost approximately in half compared to L-MRS medium.