Beta-Galactosidase Activity in Psychrotrophic Microorganisms and their Potential Use in Food Industry

KARASOVA P., SPIWOK V., MALA S., KRALOVA B., RUSSELL N.J. (2002): Beta-galactosidase activity in psychrotrophic microorganisms and their potential use in food industry. Czech J. Food Sci., 20: 43–47. Twenty-one psychrotrophic resp. psychrophilic bacterial strains were screened for presence of β-galactosidase activity which showed 8 of them. β-Galactosidase activity of these strains was determined for 2 substrates – synthetic substrate (ONPG) and lactose – and also temperature profile of this enzyme was measured. β-Galactosidase from Arthrobacter sp. C2-2 not only proved the typical properties of cold-active enzyme, but it also preferred lactose as a substrate. Therefore, it was chosen for furthe r isolation and purification and was found that it contains two β-galactosidase isoenzymes. One of them had strong preference for lactose and was able to catalyse transglycosylation reactions at low temperature. It has, thus, potential use in food technolog y.