Hydrolysis of Lactose from Cheese Whey Using a Reactor with β-Galactosidase Enzyme Immobilised on a Commercial UF Membrane

Abstract

In this study, β-galactosidase enzyme from Kluyveromyces fragilis was immobilised on a commercial polyethersulfone membrane surface, 10 kDa cut-off. An integrated process, concerning the simultaneous hydrolysis-ultrafiltration of whey lactose was studied and working conditions have been fixed at 55°C and pH 6.9, the same conditions that are used for the industrial process of protein concentration. For the immobilisation, best results were obtained using 5% (v/v) of glutaraldehyde solution and 0.03 M galactose; the total activity recovery coefficient (TARC) was 44.2%. The amount of immobilised enzyme was 12.49 mg with a total activity of 86.3 LAU at 37°C, using 5% (w/v) lactose solution in phosphate buffer (100 mM pH 6.9).The stability of the immobilised enzyme was approximately 585 fold higher in comparison with the stability of free enzyme. Multipoint covalent immobilisation improves the stability of the enzyme, thereby enhancing the decision to use the membrane as a filtering element and support for the enzyme immobilisation.

Immobilization of Enzymes in/on Membranes and their Applications

“…Regenhardt et al. also developed a β‐galactosidase REIM system . The Kluyveromyces fragilis β‐galactosidase was immobilized on a commercial polyether‐sulfone membrane by covalent linking.…”

Enzymes for food waste remediation and valorisation

“…This was the rationale behind the work of Regenhardt et al (2013), who immobilised the widely used bG from Kluyveromyces fragilis onto a polyethersulfone ultrafiltration membrane via multi-point covalent attachment with glutaraldehyde. Such systems achieve simultaneous lactose hydrolysis and ultrafiltration of proteins in a single process.…”

Beta galactosidases in Arabidopsis and tomato–a mini review

“…stearothermophilus [10,11] and are used in industry for producing lactose-free milk [12]. Thermostable BGALs are also used in dairy industry to remove lactose contaminations from whey, a major by-product from cheese [13][14][15][16]. In addition to hydrolytic activities, some microbial BGALs also have transgalactosylation activity.…”