Thermostable and alkaline-tolerant cellulase-free xylanases produced from thermotolerant Streptomyces sp
Cellulase-free xylanase was produced by Streptomyces sp. Ab106 using cane bagasse as the substrate at 55°C. Its maximum activity was 13 IU without cellulase and mannanase activities. Its profiles were investigated. Its optimum temperature and pH were 60°C and 6.0, respectively. More than 70% of its activity was remained at 60°C at pH 9. This enzyme was quite stable and exhibited an active of more than 70% for 144 h at 60°C, and of more than 80% for 144 h at 40°C, pH 9. This thermo-tolerant and alkaline-tolerant xylanase can be used in the pulp bleaching process.