59-05-032 Proceeding

53 Proceedings of the Princess Maha Chakri Sirindhorn Congress Next, the fraction NO. 13 sample was tested for hydrolysis of CMC substrates at different pH and temperature to find the optimal condition for CMCase. In this study, the pH was tested between pH 2 - 10 (Figure 3), and temperature was tested between 30 - 70°C (Figure 4). To test with different pH, in each reaction, 2% w/v of CMC substrate was mixed with 500 µl of each enzyme fraction and 500 µl of phosphate buffer that adjusted pH to tested condition. Then, each samples were incubated at 45°C for 2 h, then reactions were stopped, and subjected to DNS assay. Likewise, to test with different temperature, the same amounts of substrate, enzyme and buffer were mixed together and pHwas adjusted to 7.0. Each reactions were incubated in different temperature for 2 h, then reactions were stopped.The sugar contents were analyzed by DNS assay. The results showed that the optimal condition for CMCase activity is 55°C and pH 6.0 because the highest absorbance was observed compared to other conditions. Figure 2 SDS-PAGE (lane 1, stained with Coomassie Blue R-250) and CMC-zymogram (lane 2, stained with Congo Red) analysis of fraction No. 13 of MSL2-S2 cellulase. Figure 3 The CMCase activity of cellulase fraction No. 13 at different pH.