Immobilisation of beta-D-galactosidase from Escherichia coli on cellulose beads and its use for the synthesis of disaccharide derivatives

Potential Applications of Immobilized β-Galactosidase in Food Processing Industries

The enzyme β-galactosidase can be obtained from a wide variety of sources such as microorganisms, plants, and animals. The use of β-galactosidase for the hydrolysis of lactose in milk and whey is one of the promising enzymatic applications in food and dairy processing industries. The enzyme can be used in either soluble or immobilized forms but the soluble enzyme can be used only for batch processes and the immobilized form has the advantage of being used in batch wise as well as in continuous operation. Immobilization has been found to be convenient method to make enzyme thermostable and to prevent the loss of enzyme activity. This review has been focused on the different types of techniques used for the immobilization of β-galactosidase and its potential applications in food industry.

Transglycosylation in a two-phase aqueous-organic system with catalysis by a lipid-coated beta-D-galactosidase

A lipid-coated beta-D-galactosidase was prepared in which the enzyme surface is covered with a lipid monolayer and two long alkyl lipophilic tails serve to solubilize the enzyme in organic solvents. In a two-phase aqueous-organic system, a lipid-coated enzyme exists in the organic (2-propyl ether) phase and acts as an efficient transgalactosylation catalyst for various hydrophobic alcohols with lactose in the aqueous buffer solution. When a native beta-D-galactosidase was employed in the two-phase system, neither the transgalactosylation nor the hydrolysis reaction proceeded due to denaturation of the enzyme at the interface. Effects of coating lipid molecules, origins of enzymes, reaction in organic solvents, and chemical structures of acceptor alcohols on the transgalactosylation catalyzed by the lipid-coated enzyme were studied. This system could also be applied in a large-scale synthesis on the 0.1-1 g scale.

Biochemical engineering of biocatalysts immobilized on cellulosic materials

Complete design of the optimum immobilized biocatalyst seems to still be a matter of the future. To be successful, it would require numerical determination of all significant parameters at each enzyme engineering phase, that is at the design of the carriers, immobilized biocatalysts and immobilized reactors. Future research trends should follow this strategy. For processing, cellulosic materials have been considered carriers that fulfill requests to an example model: they represent a unique family of carriers that cover a broad variety of physical and chemical properties, immobilizing techniques, and immobilized reactors as well. The reason for writing this review article was to test the reliability of such a processing and subsequently, to confront theoretical considerations with practical applications of biocatalysts immobilized on cellulose materials.