Cell Disruption Optimization and Covalent Immobilization of β-D-Galactosidase from Kluyveromyces marxianus YW-1 for Lactose Hydrolysis in Milk

Abstract

beta-D-galactosidase (EC 3.2.1.23) from Kluyveromyces marxianus YW-1, an isolate from whey, has been studied in terms of cell disruption to liberate the useful enzyme. The enzyme produced in a bioreactor on a wheat bran medium has been successfully immobilized with a view to developing a commercially usable technology for lactose hydrolysis in the food industry. Three chemical and three physical methods of cell disruption were tested and a method of grinding with river sand was found to give highest enzyme activity (720 U). The enzyme was covalently immobilized on gelatin. Immobilized enzyme had optimum pH and temperature of 7.0 and 40 degrees C, respectively and was found to give 49% hydrolysis of lactose in milk after 4 h of incubation. The immobilized enzyme was used for eight hydrolysis batches without appreciable loss in activity. The retention of high catalytic activity compared with the losses experienced with several previously reported immobilized versions of the enzyme is significant. The method of immobilization is simple, effective, and can be used for the immobilization of other enzymes.

Immobilization of β-d-galactosidase from Kluyveromyces lactis on functionalized silicon dioxide nanoparticles: Characterization and lactose hydrolysis

“…This may be due to higher thermal stability of nanoparticle bound BGAL than free enzyme. Lactose hydrolysis by immobilized BGAL was achieved in 3 h [35] and 4 h [1], respectively by other investigators. This immobilized enzyme preparation will be suitable for obtaining fermentable sugars from dairy whey.…”

“…Beta-d-galactosidase (␤-d-galactoside galactohydrolase, EC.3.2.1.23), most commonly known as lactase, is a hydrolytic enzyme that catalyses the breakdown of lactose into glucose and galactose [1,2]. The enzyme can be obtained from a variety of sources like microorganisms, plants, and animals.…”

Immobilization of Aspergillus oryzae β galactosidase on zinc oxide nanoparticles via simple adsorption mechanism

“…High costs of enzymes used for industrial purposes and the time necessary for their immobilization for subsequent use have led to increase the possibility of reusing immobilized enzyme [30,31]. ZnO-NP adsorbed ␤ galactosidase retained nearly 89% activity after its fourth repeated use (Fig.…”

Applications of β-gal-III isozyme from Bacillus coagulans RCS3, in lactose hydrolysis

“…At 10% lactose only 48% hydrolysis took place with 50 U of enzyme concentration. Lactose (4.8%) hydrolysis of 95% using 150 U of immobilized ␤-galactosidase was observed by Puri et al [43]. However, further increase in enzyme concentration does not lead to increase degree of hydrolysis.…”