Increase in an Intracellular β-Galactosidase Biosynthesis Using L. reuteri NRRL B-14171, Inducers and Alternative Low-Cost Nitrogen Sources under Submerged Cultivation

Abstract

AbstractThe aim of this study was to select among lactic acid bacteria (LAB) and yeast a potential β-galactosidase producer, based on bioprocess parameters. From the selected microorganism,  different organic cheaper nitrogen sources (single and combined) with low cost for β-galactosidase production were evaluated. Lactobacillus reuteri B-14171 showed the highest enzymatic activity (1,286 U L−1), high productivity (28.78 U L h−1) and yield factor (82.32 U g−1), evidencing its potential for β-galactosidase production. All organic nitrogen sources tested were viable for the enzymatic production using L. reuteri B-14171. The MMRS casein (3.0 g L−1) + inactive beer yeast (3.0 g L−1) as nitrogen source increased the enzymatic activity (1269 U L−1) with 1.83 times lower production costs of culture medium when compared to MMRS-yeast extract B. The MMRS casein + inactive beer yeast has proved to be an innovative and cheaper nitrogen source for β-galactosidase production by L. reuteri B-14171.