Isolation and molecular identification of new Kluyveromyces lactis strains producing high levels of lactase and invertase enzymes

Abstract

Six different new Kluyveromyces lactis strains were isolated from different dairy products from Bursa province, Turkey. Lactase and invertase enzyme activities of new K. lactis strains were determined under different growth conditions. Our results indicate that both lactase and invertase enzyme activities of new K. lactis strains are much higher than the standard K. lactis (ATCC8585). Lactase and invertase enzymes are expressed at high levels under glucose repressed growth conditions in some of these K. lactis strains. Invertase activities of new K. lactis strains are 10-fold higher than the standard K. lactis (ATCC8585) strain. Additionally, it was shown that the two of the new K. lactis strains have 25% shorter duplication times than the normal K. lactis (ATCC8585). Our results indicate that new K. lactis strains isolated from the local dairy products of the Bursa region of Turkey have distinct metabolic features with respect to the regulation of GAL/LAC regulon of K. lactis.