Specific features of enzymatic hydrolysis of cellulose

In this article, the features of enzymatic hydrolysis of cellulose samples with different structural characteristics were studied. It was discovered that outer paracrystalline layers of crystallites are accessible and susceptible to hydrolysis along with the poorly ordered amorphous domains of cellulose. The thermodynamic analysis showed that the hydrolysis process of cellulose samples at 298 K is exothermic. Since reaction enthalpy is negative and the temperature-entropy factor is positive, the Gibbs potential of this process becomes negative, which contributes to the implementation of enzymatic hydrolysis of cellulose. Moderate enhancement in temperature to optimal value, 323 K, increases the negative value of Gibbs potential and thereby promotes the hydrolysis of cellulose substrates. The most negative Gibbs potential was observed for the hydrolysis of the most accessible amorphous cellulose. Thus, amorphization of cellulose substrates facilitates enzymatic hydrolysis. On the other hand, the enzymatic hydrolysis of high-ordered crystalline domains of cellulose cannot be performed even at optimal temperature since the Gibbs potential of this process is close to zero.