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

Abstract

Solid-state fermentation was carried out for the production of extracellular alpha-galactosidase by Streptomyces griseoloalbus. Soybean flour was the best solid substrate for alpha-galactosidase production. In flask-level optimization, the highest enzyme yield of 111 +/- 0.2 U/gds was obtained under optimal conditions. The partially purified a-galactosidase preparation showed highest activity at pH 5.0 and 65 degrees C. The enzyme was completely stable at pH 5.0 to 7.0 and at 50 and 55 degrees C for 5 h. The t(1/2) of the enzyme at 65 degrees C was 3.5 h. The information obtained from the present investigation is advantageous for food industrial applications of S. griseoloalbus alpha-galactosidases.