β-glucoside production by thermophilic bacteria indigenous the bolivian altiplano culture

Abstract

The β-glucosidases possess hydrolytic and transferase activity or transglucosidase. They have various applications; such as biosynthesis of oligosaccharides, production of ethanol using agricultural residues and wine industry. However for industrial application, stability to high temperatures is needed. Therefore a great interesting in the thermophile microorganism study exist. The purpose of this research is to optimize the culture medium of thermophilic anaerobic bacteria to increase the production of β-glucosidase. This enzyme is produced by three isolate bacterial FT3, 2B and P5 which were isolated from the Andean region of Bolivia. FT3 isolate showed β-glucosidase activity of 0.35 (IU/mL). In regards to the optimization of culture medium variables such as nitrogen source, carbon source and pH were taken into account and also the combina- tion with free and encapsulated bacterial cells. Yeast extract was the selected source of nitrogen obtaining an activity of 0.52 (IU/ mL). The optimal pH was 5 obtaining an activity of 0.81 (IU/mL). The selected carbon source was the hydroly- zed wheat straw and quinoa straw obtaining activities of 1.27 and 1.34 (IU/mL), respectively. The cellular localization of β-glucosidase enzyme is extracellular and provides stability to temperature of 80 °C and stability at pH 7.