A novel bacterial mannanase from Streptomyces tendae: purification, characterization and application to hydrolysis of spent coffee ground

β-Mannanase (1, 4-β-D-mannan mannanohydrolase, EC 3.2.1.78), catalyzes the random hydrolysis of β-1, 4-mannosidic linkages in mannans. Wide range of application has been explored in the food and pharmaceutical industry for the production of fruit juices and the degradation of plant materials. In this study, bacterial mannanase from Streptomyces tendae was purified for homogeneity from the culture supernatant. The extracellular mannanase was purified 9.6 fold with a 26.3% yield using Sepharose Cl-6B column. The characterization of the enzyme (MnSt) was performed and the results were as follow; molecular mass of 24 kDa with an optimum temperature and pH of 50 ºC and 12.0, respectively. MnSt had K_m and V_max values of 0.05±1 mg/mL and 439±0.5 mmol/min, respectively when using different concentrations (0.6 to 10 mg/mL) of substrate (locust bean gum galactomannan). Finally, the mananase was utilized in saccharification process of spent coffee grounds for the production of fermentable sugars (mannose). The hydrolysates have potential industrial applications such as biofuels and biochemicals production.