Production of xylanase and CMCase on solid state fermentation in different residues by Thermoascus aurantiacus miehe

Abstract

The use of waste as raw material is important for government economy and natural balance. The purpose of this work was to study the production of CMCase and xylanase by a Brazilian strain of Thermoascus aurantiacus in solid state fermentation (SSF) using different agricultural residues (wheat bran, sugarcane bagasse, orange bagasse, corncob, green grass, dried grass, sawdust and corn straw) as substrates without enrichment of the medium and characterize the crude enzymes. The study of the extracellular cellulolytic and hemicellulolytic enzymes showed that T. arantiacus is more xylanolytic than cellulolytic. The highest levels of enzymes were produced in corncob, grasses and corn straw. All the enzymes were stable at room temperature by 24 h over a broad pH range (3.0-9.0) and also were stable at 60°C for 1 h. The optimum pH and temperature for xylanase and CMCase were 5.0-5.5 and 5.0 and 75°C, respectively. The microorganism grew quickly in stationary, simple and low cost medium. The secreted extracellular enzymes presented properties that match with those frequently required in industrial environment.