Study of Chemical and Enzymatic Hydrolysis of Cellulosic Material to Obtain Fermentable Sugars

Abstract

The objective of this study was to evaluate the chemical and enzymatic hydrolysis using a factorial experimental design (2 3 ) in order to obtain fermentable sugars from cellulose-based material (CBM) usually used as pet litter. In assessing chemical hydrolysis, we studied the effect of temperature, in addition to H 2 SO 4 concentration and reaction time, on the production of total sugars, reducing sugars, soluble lignin, carbohydrate profile, furfural (F), and hydroxymethyl furfural (HMF). We performed a response surface analysis and found that, at 100 ∘ C, 1% acid concentration, and 60 min reaction time, the yields of 0.0033 g reducing sugar/g biomass and 0.0852 g total sugars/g biomass were obtained. Under the above conditions, F is not generated, while HMF is generated in such a concentration that does not inhibit fermentation. We pretreated the CBM with H 2 SO 4 , NaOH, CaO, or ozonolysis, in order to evaluate the effectiveness of the enzymatic hydrolysis from the pretreated biomass, using an enzymatic cocktail. Results showed that CBM with acid was susceptible to enzymatic attack, obtaining a concentration of 0.1570 g reducing sugars/g biomass and 0.3798 g total sugars/g biomass. We concluded that acid pretreatment was the best to obtain fermentable sugars from CBM.

Conversion of Lignin to Heat and Power, Chemicals or Fuels into the Transition Energy Strategy

“…A modern and integrated biorefinery will process low-value biomass into energy for selfconsumption and export excess to the grid. More valuable biomass may be used for the production of edible or nonedible oils, protein-rich flour for fish/shrimp farms and used to convert the lignocellulosics into fuels and chemicals [4]. We have identified four additional market niches for lignin derivatives: (1) conventional paper-related derivatives;…”

“…Biomass is mainly composed of three macromolecular biopolymers known as cellulose, hemicellulose, and lignin. Cellulose is composed of β-D-glucopyranose units linked by (1)(2)(3)(4) glucosidic bonds and different polymorphs has been described from high to amorphous crystallinities [22]. On the other hand, hemicellulose is mostly amorphous and generally classified into four groups: (1) xyloglycans (xylans), (2) mannoglycans (mannans), (3) xyloglucans and (4) mixed-linked β-glucans [12].…”

Heterologous expression and characterization of a cold-adapted endo-1,4−β−glucanase gene from Bellamya chinensis laeta

“…Delignification of wood samples promotes solubility as in the case of hemicellulose, but delignified cellulose remains insoluble [22]. To hydrolyze delignified cellulose using cellulase, pretreatment such as acid, NaOH, and oxidation are efficient [23]. In particular, cellulose pretreated with acid was well solubilized in water, and significantly increased the production of reducing sugars during the hydrolysis process using an enzymatic cocktail of cellulases and hemicellulases [23].…”

“…To hydrolyze delignified cellulose using cellulase, pretreatment such as acid, NaOH, and oxidation are efficient [23]. In particular, cellulose pretreated with acid was well solubilized in water, and significantly increased the production of reducing sugars during the hydrolysis process using an enzymatic cocktail of cellulases and hemicellulases [23]. The optimum operating temperature of the SSF process is around o C. We compared the specific activities toward soluble cellulose of rBC-EG70amature, as well as T. reesei and T. viride cellulases, at this temperature.…”

Enzymatic Hydrolysis of Two-way Pretreated Sawdust of <i>Eucalyptus globulus</i> and <i>Cupressus lusitanica</i>

“…But the lignin-hemicellulose matrix surrounding the cellulose microfibrils prevents the microbial enzymes' access to cellulose and inhibits its hydrolysis. This is usually solved by the removals or modifications of lignin and/or hemicelluloses (Amezcua-Allieri et al, 2017).…”