Partially purified α-galactosidase from Bacillus sp. LX-1 was non-covalently immobilized on a reversibly soluble-insoluble polymer, Eudragit L-100, and an immobilization efficiency of 0.93 was obtained. The optimum pH of the free and immobilized enzyme was 6.5 to 7.0 and 7.0, respectively, while there was no change in optimum temperature between the free and immobilized α-galactosidase. The immobilized α-galactosidase was reutilized six times without significant loss in activity. The immobilized enzyme showed good storage stability at 37°C, retaining about 50% of its initial activity even after 18 d at this temperature, while the free enzyme was completely inactivated. The immobilization of α-galactosidase from Bacillus sp. LX-1 on Eudragit L-100 may be a promising strategy for removal of α-galacto-oligosaccharides such as raffinose and stachyose from soybean meal and other legume in feed industry.
