Chiang Mai Journal of Science

 Biotechnological processing uses enzymes and microorganisms to make a wide range of valuable products in many industrial sectors. This study investigated the culture conditions of the production of two enzymes, xylanase and cellulase, by Lentinus polychrous Lev. LP-PT-1, under solid state fermentation, using economical rice straw as a substrate. The optimum temperatures and pH of enzyme activities and stabilities were examined and it was shown that the optimal temperature was 35°C. The 75% and 80% moisture levels showed significantly higher cellulase production than other treatments (p < 0.05) and also significantly higher xylanase production than 50% and 55% moisture levels (p < 0.05). The inoculum level at 0.5 cm per disk for the four disks in 4g substrate culture was found to be the optimum for the production of xylanase and cellulase by L. polychrous Lev. LP-PT-1. The incubating temperature is one of the most significant factors that strongly affects the production of xylanase and cellulase. The relatively good thermo-stability of xylanase and cellulase was maintained at a high temperature of 60°C with 89% and 81% of the remaining activity. The xylanase appeared to be stable over a broad pH range of 4.0–7.0. The cellulase was stable at pH 4.0-5.0 with 94% remaining activity. High cellulase activity was achieved at temperatures between 30 and 60°C. The xylanase activity increased with high temperatures to 60°C. The optimum pH for cellulase and xylanase activity was found in the range of pH 4.0-6.0. The findings revealed that the high thermo-stability of xylanase and cellulase from L. polychrous Lev.LP-PT-1 was potentially beneficial in industrial biotechnological applications