Production and characterization of partially purified thermostable α-galactosidases from Streptomyces griseoloalbus for food industrial applications

Solid-state fermentation was carried out for the production of extracellular α-galactosidase by Streptomyces griseoloalbus. Soybean flour was the best solid substrate for α-galactosidase production. In flask-level optimization, the highest enzyme yield of 111 ± 0.2 U/gds was obtained under optimal conditions. The partially purified α-galactosidase preparation showed highest activity at pH 5.0 and 65 °C. The enzyme was completely stable at pH 5.0 to 7.0 and at 50 and 55 °C for 5 h. The t1/2 of the enzyme at 65 °C was 3.5 h. The information obtained from the present investigation is advantageous for food industrial applications of S. griseoloalbus α-galactosidases.