Structural features of dilute acid, steam exploded, and alkali pretreated mustard stalk and their impact on enzymatic hydrolysis

Alkaline Pretreatment of Banana Stems for Methane Generation: Effects of Temperature and Physicochemical Changes

“…Increasing amounts of hydrolysis of the glycosidic linkages under harsher NaOH catalyzed conditions in the accessible regions of the cellulose fibers resulted in an increase of CI, and it was also presumably related to the removal of amorphous substances, hence increasing the fraction of crystalline polymer. The same trend in CI with temperature has been observed previously, for example, with pretreatment of mustard with NaOH (Sindhu et al 2012;Yang et al 2014;Kapoor et al 2015). However, the opposite trend with temperature was observed with wheat plant (grain and straw) pretreated with NaOH (He et al 2008;Taherdanak and Zilouei 2014).…”

Deconstruction of corncob by steam explosion pretreatment: Correlations between sugar conversion and recalcitrant structures

“…Biomass CrI is defined as the mass fraction of crystalline cellulose in the biomass. Many studies analyzed biomass CrI from the XRD data and found it increased after steam explosion pretreatment due to removal of amorphous hemicellulose (Huang et al, 2015;Kapoor et al, 2015). However, cellulose CrI, obtained by dividing biomass crystallinity with cellulose content in the biomass, reflects real changes in cellulose crystalline structure during pretreatment .…”

“…Therefore, the final sugar conversion is determined by a balance between these two factors. It is generally believed that increased specific surface area leads to improved enzyme accessibility (Fernandes et al, 2015;Kapoor et al, 2015). It should be mentioned that higher affinity of the biomass for cellulases does not necessarily result in increased saccharification due to the changes in chemical structures of lignin (Monschein & Nidetzky, 2016) or cellulose crystalline structures (Gao, Chundawat, Sethi, Balan, Gnanakaran & Dale, 2013).…”

“…While no clear correlation between biomass crystallinity and sugar conversion has been found in many studies that involved steam explosion pretreatment (Huang et al, 2015;Kapoor et al, 2015;Liu, Qin, Li & Yuan, 2015), the overall degree of order in cellulose, measured by FTIR, has been shown to play a negative role in enzymatic hydrolysis of rice straw, cotton stalk and mustard stalk (Gaur et al, 2015). Specific surface area has been correlated positively with glucose conversion at 72h enzymatic hydrolysis of several agricultural residues pretreated by steam explosion, dilute acid, and alkali (Gaur et al, 2015;Kapoor et al, 2015). Yet, in another study of enzymatic hydrolysis of corn stover pretreated by dilute acid and steam explosion, it is reported that final glucose conversion at 168 h is affected by lignin content instead of the surface area (Liu, Qin, Li & Yuan, 2015).…”

Structural Characterization of Lignin Isolated from Wheat-Straw during the Alkali Cooking Process

“…Several methods have been developed to separate lignin from lignocellulosic biomass, including chemical (dilute acid or alkali, organosolv, and ionic liquid), physical (mechanical extrusion), physico-chemical (steam explosion), and biological (white and soft rot fungi) (Kapoor et al 2015). Alkaline treatment is the most widespread and costeffective method for isolating lignin (mainly alkali lignin).…”