The using of enzymes for degradation of cellulose substrate for the ...

37th International Conference of SSCHEMay 24–28, 2010, Tatranské Matliare, SlovakiaPo-Th-6, 116p.pdfFig. 3. Enzymatic hydrolysisExperiment No. 1 (E1)In the first series of experiments with compound of enzymes 5mg of enzymes were added into 200 mlof deionized water. The solution was stirred until dissolved enzymes. In the next step 3 g of cellulosesubstrate were added. The temperature was 37°C and mixture wasn’t stirred. Degradation of substrateto glucose was determined by glucose- oxidation test and by measurement of COD values.Experiment No. 2 (E2)In another series of experiments 50 mg of compound of enzymes were dissolved in 200 ml of deionizedwater. The solution was stirred until dissolved enzymes. In the next step 3 g of cellulose substrate wereadded. The temperature was 37°C and mixture wasn’t stirred. Degradation of substrate to glucose wasdetermined by glucose- oxidation test and by measurement of COD values.Experiment No. 3 (E3)In final series of experiments with compound of enzymes 450 mg of enzymes were dissolved in 200 mlof deionized water. The solution was stirred until dissolved enzymes. In the next step 3 g of cellulosesubstrate were added. The temperature was 37°C and mixture wasn’t stirred. Degradation of substrateto glucose was determined by glucose- oxidation test and measurement of COD values.3. Results and discussionEnzymatic hydrolysis decomposes cellulose to cellotetrose and cellobiose in first step. Subsequentlycellotetrose and cellobiose are degradated to glucose, lower aldehydes and ketones (Fig. 4). Products ofenzymatic hydrolysis depends on the type and composition of the substrate, the reaction time, the typeand quantity of the enzymes and the reaction temperature. Glucose itself can be enzymatic degraded toaldehydes and ketones.Compound of enzymes was used for the degradation of cellulosic substrate. Time dependence ofglucose production resulting from substrate degradation is shown in figure 5. From each experiment isappeared that the production of glucose is affected by the amount of enzymes used, quantity ofsubstrate, reaction temperature and time. The highest glucose yield was achieved in the experiments no.3. In experiment No. 2 and 3. a decrease in glucose concentration after 24 hrs. was observed, whichwas caused by the amount of used enzymes (Tab. 1, Fig. 4).1409