Immobilization of β‐Galactosidase on Fibrous Matrix by Polyethyleneimine for Production of Galacto‐Oligosaccharides from Lactose

摘要: The production of galacto-oligosaccharides (GOS) from lactose by Aspergillus oryzae ‚-galactosidase immobilized on cotton cloth was studied. A novel method enzyme immobilization involving PEI-enzyme aggregate formation and growth aggregates individual fibrils leading to multilayer the developed. large amount (250 mg/g support) with about 90-95% efficiency. maximum GOS 25-26% (w/w) achieved at near 50% conversion 400 g/L pH 4.5 40 °C. Tri- tetrasaccharides were major types formed, accounting for 70% 25% total produced in reactions, respectively. Temperature affected not only reaction rate but also yield some extend. 6.0 increased as much 10% compared that while decreased enzyme. support matrix did affect characteristics under same conditions, suggesting diffusion limitation negligible packed bed reactor carrier. Increase thermal stability PEI-immobilized observed. half-life close 1 year °C 21 days 50 Stable, continuous operation a plug-flow demonstrated 3 without any apparent problem. 26% sugars attained feed containing corresponding productivity 6 kg/L/h, which is several-hundred-fold higher than those previously reported.