Cellulase is an enzyme that hydrolyzes cellulose to produce glucose and cellobiose. Including C 1 enzyme, CX enzyme and cellobiase. C 1 enzyme makes natural cellulose crystal chain crack and become linear cellulose. CX enzyme can not hydrolyze natural cellulose, but can decompose β- 1 4 glycosidic bond of linear cellulose to produce cellobiose. Cellulose is converted into glucose by cellobiase. Sodium carboxymethyl cellulose (CMC) is used as the substrate of cellulase. However, it should be pointed out that CMC is different from natural cellulose in structure and performance. Natural cellulose is insoluble in water, while CMC is hydrophilic and easy to be decomposed by cellulase. Under the same conditions, the reducing sugar produced by the same cellulase decomposing CMC is much larger than that produced by natural cellulose hydrolysis.

operational approach

Citric acid with pH value of 4.6 buffers 26.7ml of citric acid solution with concentration of 0. 1 mol/L and 23.3ml of disodium hydrogen phosphate solution with concentration of 0.2 mol/L, and then adds water to dilute it to 1000ml.

Disodium hydrogen phosphate-citric acid buffer with pH value of 5.0 Take 25.7ml of disodium hydrogen phosphate solution with concentration of 0.2mol/L and 24.3m 1 citric acid solution with concentration of 0. 1mol/L, mix them and add water to dilute them to 1000ml.

Weigh CMC 1g into sodium carboxymethyl cellulose solution, add 1000ml of water, heat in water bath to dissolve, then add 20 ml of disodium hydrogen phosphate-citric acid buffer with pH value of 5.0 and 40ml of water, and mix well.

Determination of enzyme activity of the sample Take 5g cellulase powder, fully grind it, add 100ml distilled water, stir 3Omin in a water bath at 40℃ to fully dissolve the enzyme protein, filter it, centrifuge the supernatant and dilute it to an appropriate multiple. Absorb diluted enzyme solution lml, add 4ml CMC solution, mix well, and saccharify at 40℃ for 30min.