Gentiobiose synthesis from glucose using recombinant β-glucosidase from Thermus caldophilus GK24

Recombinant beta-glucosidase from Thermus caldophilus GK24 was easily purified partially by a heat treatment procedure, resulting in 8-fold and recovery yield of 80% from crude enzyme. When the beta-glucosidase was incubated with a 80% glucose solution (w/w), gentiobiose (beta1,6-glucobiose) was the major product in the reaction mixture. The optimal conditions for producing gentiobiose (11% yields of total sugar) were pH 8-9 and 70degreesC for 72 h.