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 combination 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 hydrolyzed 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.