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Although the production of carboxymethylcellulose from different raw materials is commercial, its preparation from agro-industrial residues has still been poorly explored in terms of performance, cost-effectiveness, and sustainability. Here, sugarcane bagasse was used as raw material for the carboxymethylcellulose (CMCb) synthesis within the biorefinery context. Sequential treatments were used for the removal of hemicellulose and lignin and the isolation of cellulose, whose conversion into CMCb was carried out through treatments with NaOH and monochloroacetic acid (MCA). The chemical modifications led to a CMCb with a substitution degree of 0.44, purity of 71.3 %, and 32 % crystallinity. Our residue-based CMCb was adequate for microorganism encapsulation, a high-value application, promoting viable conidia after 5 months of storage in equivalent conditions of high-purity, commercial CMC. Our findings show a route for the preparation of valuable polysaccharides from waste in future biorefineries, which, depending on their characteristics, can be applied in different processes. Here we use them for the encapsulation of a bioagent, although they can easily be used in other applications such as packaging and coating., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The feasibility of integration of cellulosic ethanol production with the manufacture of cellulose nanofibers (CNF) and cellulose nanocrystals (CNC) was evaluated using eucalyptus cellulose pulp as feedstock and employing the biochemical route alone. For the enzymatic hydrolysis step, experimental central composite design (CCD) methodology was used as a tool to evaluate the effects of solids loading (SL) and enzymatic loading (EL) on glucose release and cellulose conversion. Glucose concentrations from 45 to 125 g/L were obtained after 24 h, with cellulose conversions from 35 to 96%. Validation of the statistical model was performed at SL of 20% and EL of 10 mg protein/g, which was defined by the desirability function as the optimum condition. The sugars released were used for the production of ethanol by Saccharomyces cerevisiae, resulting in 62.1 g/L ethanol after 8 h (yield of 95.5%). For all the CCD experimental conditions, the residual solids presented CNF characteristics. Moreover, the use of a new strategy with temperature reduction from 50 to 35°C after 24 h of enzymatic hydrolysis enabled CNC to be obtained after 144 h. The CNC showed a crystallinity index of 83%, length of 260 nm, diameter of 15 nm, and aspect ratio (L/D) of 15. These characteristics are suitable for many applications, such as reinforcement in polymeric materials and other lower volume higher value bio-based products. The findings indicate the viability of obtaining ethanol and CNC using the biochemical route exclusively, potentially contributing to the future implementation of forest biorefineries. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1085-1095, 2017., (© 2017 American Institute of Chemical Engineers.)

Cellulose nanostructures obtained from lignocellulosic biomass by the enzymatic route can offer advantages in terms of material properties and processing sustainability. However, most of the enzymatic cocktails commonly used in the saccharification of biomass are designed to promote the complete depolymerization of the cellulose structure into soluble sugars. Here, investigation was made of the way that the action of different commercially available cellulase enzyme cocktails can affect the production of nanocellulose. For this, enzymatic cocktails designed for complete or partial saccharification were compared, using eucalyptus cellulose pulp as a model feedstock. The results showed that all the enzymatic cocktails were effective in the formation of nanocellulose structures, with the complete saccharification enzymes being more efficient in promoting the coproduction of glucose (36.5 g/L, 87% cellulose conversion). The presence of auxiliary enzymes, especially xylanases, acted cooperatively to favor the production of nanostructures with higher crystallinity (up to 79%), higher surface charge (zeta potential up to −30.9 mV), and more uniform dimensions within the size range of cellulose nanocrystals (80 to 350 nm). Interestingly, for the enzymatic cocktails designed for partial saccharification, the xylanase activity was more important than the endoglucanase activity in the production of nanocellulose with improved properties. The findings showed that the composition of the enzymatic cocktails already used for complete biomass saccharification can be suitable for obtaining nanocellulose, together with the release of a glucose stream, in a format compatible with the biorefinery concept. • Cellulose nanostructures using enzymes can offer advantages in their properties. • The action of different enzyme cocktails affects nanocellulose production. • Xylanase was more important than endoglucanase in terms of nanocellulose properties. • Enzyme cocktails for complete saccharification are suitable to obtain nanocellulose. [ABSTRACT FROM AUTHOR]