Abstract
A simple chemical mutagenesis technique was used to enhance the activity of alpha- and beta-galactosidases in Lactobacillus reuteri CF2-7F. Ethyl methanesulfonate (EMS), a classical chemical, was used for that purpose. The culture was treated with EMS for 2 hrs, and then was plated on either X-gal or X-alpha-gal to screen colonies with high alpha- or beta-galactosidase activity, respectively. We were not able to find mutagenized colonies for alpha-galactosidase activity. While, two mutagenized colonies for beta-galactosidase activity were selected and then were grown on an enhanced growth media and beta-galactosidase activity was assayed. Results showed that the chemical mutagenesis of L. reuteri CF2-7F led to 112.56 Gal U/ml activity of beta-galactosidase with 137.3% enhancement over our best previous results (82.01 Gal U/ml). This shows that chemical mutagenesis might be an effective method in enhancing enzymatic activity of L. reuteri CF2-7F, and this strain could be used in the food industry for its enhanced probiotic properties.