Immobilization of Beta-Galactosidase from Bacillus circulans on agarose supports and their use in the synthesis of Gal(B1-3)GlcNAc and Gal(B1-3)GalNAc.

GÓMEZ, SARA; NAVARRETE, SERGIO; BAYÓN, CARLOS; LEVIN, GUSTAVO J.; HERNÁIZ, MARÍA J.

Madrid

Congreso; ANQUE-ICCE-BIOTEC 2014; 2014

Sociedad Española de Biotecnología (SEBIOT)

Oligosaccharides present on the cell surface are involved in many biological processes. Specifically, Beta(1→3) linked galactosides such as GalB1-3GalNAc and GalB1-3GlcNAc are key carbohydrate structures involved in many biological processes. There is consequently much interest in the chemical or enzymatic synthesis of these galacto-glycosides. Recently we have reported the synthesis of GalB1-3GalNAc and GalB1-3GlcNAc by using the B-galactosidase from Bacillus circulans in the presence of different green solvents obtaining high conversions and excellent regioselectivity [1, 2] However, using soluble enzymes as biocatalysts has some drawbacks such as reduced stability under operational conditions, difficult recovery and hard multiple reusal of the enzyme in industrial processes. These drawbacks can often be overcome by enzyme immobilization. In this context, activated agarose supports are almost ideal matrices for performing very easy enzyme immobilization in laboratory and industrial scale. In this comunication B-galactosidase from Bacillus circulans was immobilized on different cross-linked agarose supports. Four types of glyoxyl supports were screened: glyoxyl-agarose, metal chelate, anionic and cationic glyoxyl-agarose. The best results were obtained with the glyoxyl-agarose support. This immobilized enzyme retains high catalytic activity, displays maximum activity at pH 6.00 and increased thermal stability compared with the free enzyme. Production of GalB1-3GlcNAc was performed in buffer and in presence of green solvents and we found that the immobilized derivative can be usefully applied as a recoverable and reusable enzyme in buffer and green solvents presence for the synthesis of GalB1-3GlcNAc with high yield and regioselectivity. Best results for GalB1-3GlcNAc production were obtained with Ionic Liquid BmimPF6 and N,N-dimethylacetamide as cosolvents.