STM Article Repository

Enzymatic hydrolysis of a large number of not-treated and pretreated plant materials containing different amounts of cellulose with various crystallinity and amorphous ligno-hemicellulose complex has been studied. The effect of constituents and crystallinity degree of cellulose on yield of glucose was found, and correlation analysis was carried out. This analysis showed that lignin-hemicellulose complex (LHC) affected negatively on enzymatic cleavage of cellulose, and namely an inversely proportional regression between content of LHC in the samples and yield of glucose was observed. Conversely, increased content of cellulose with decreased crystallinity degree promotes enzymatic hydrolysis and affects positively on yield of glucose. The best correlation was discovered for the dependence of glucose yield (Y) on the combined parameter P, which includes the content and crystallinity of cellulose, as well as the content of LHC in the investigated biomass samples. As follows from the regression equation Y=f(P), an increased content of cellulose, its reduced crystallinity, as well as decreased content of LHC in the samples, promote enzymatic cleavage of the cellulosic component. The discovered correlation Y=f(P) permits prediction the saccharification degree of pretreated biomass, which can be used for choice the best pretreatment method. In particular, a nitric acid/alkaline pretreatment of herbaceous plants provides the delignified biomass containing the low-crystalline cellulose having an enhanced enzymatic digestibility and maximum glucose yield.