Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Endo-Exoglucanase Synergism for Cellulose Nanofibril Production Assessment and Characterization.

ABSTRACT: A study to produce cellulose nanofibrils (CNF) from kraft cellulose pulp was conducted using a centroid simplex mixture design. The enzyme blend contains 69% endoglucanase and 31% exoglucanase. The central composite rotational design (CCRD) optimized the CNF production process by achieving a higher crystallinity index. It thus corresponded to a solid loading of 15 g/L and an enzyme loading of 0.974. Using the Segal formula, the crystallinity index (CrI) of the CNF was determined by X-ray diffraction to be 80.87%. The average diameter of the CNF prepared by enzymatic hydrolysis was 550-600 nm, while the one produced by enzymatic hydrolysis and with ultrasonic dispersion was 250-300 nm. Finally, synergistic interactions between the enzymes involved in nanocellulose production were demonstrated, with Colby factor values greater than one.

SUBMITTER: Ramirez Brenes RG

PROVIDER: S-EPMC9921176 | biostudies-literature | 2023 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Endo-Exoglucanase Synergism for Cellulose Nanofibril Production Assessment and Characterization.

Ramírez Brenes Ricardo Gonzalo RG Chaves Lívia da Silva LDS Bojorge Ninoska N Pereira Nei N

Molecules (Basel, Switzerland) 20230118 3

A study to produce cellulose nanofibrils (CNF) from kraft cellulose pulp was conducted using a centroid simplex mixture design. The enzyme blend contains 69% endoglucanase and 31% exoglucanase. The central composite rotational design (CCRD) optimized the CNF production process by achieving a higher crystallinity index. It thus corresponded to a solid loading of 15 g/L and an enzyme loading of 0.974. Using the Segal formula, the crystallinity index (CrI) of the CNF was determined by X-ray diffrac ...[more]

PMID: 36770616

Similar Datasets

Endo-exo synergism in cellulose hydrolysis revisited.

Project description:Synergistic cooperation of different enzymes is a prerequisite for efficient degradation of cellulose. The conventional mechanistic interpretation of the synergism between randomly acting endoglucanases (EGs) and chain end-specific processive cellobiohydrolases (CBHs) is that EG-generated new chain ends on cellulose surface serve as starting points for CBHs. Here we studied the hydrolysis of bacterial cellulose (BC) by CBH TrCel7A and EG TrCel5A from Trichoderma reesei under both single-turnover and "steady state" conditions. Unaccountable by conventional interpretation, the presence of EG increased the rate constant of TrCel7A-catalyzed hydrolysis of BC in steady state. At optimal enzyme/substrate ratios, the "steady state" rate of synergistic hydrolysis became limited by the velocity of processive movement of TrCel7A on BC. A processivity value of 66 ± 7 cellobiose units measured for TrCel7A on (14)C-labeled BC was close to the leveling off degree of polymerization of BC, suggesting that TrCel7A cannot pass through the amorphous regions on BC and stalls. We propose a mechanism of endo-exo synergism whereby the degradation of amorphous regions by EG avoids the stalling of TrCel7A and leads to its accelerated recruitment. Hydrolysis of pretreated wheat straw suggested that this mechanism of synergism is operative also in the degradation of lignocellulose. Although both mechanisms of synergism are used in parallel, the contribution of conventional mechanism is significant only at high enzyme/substrate ratios.

| S-EPMC3436550 | biostudies-literature

Endo- and exoglucanase activities in bacteria from mangrove sediment.

Project description:The mangrove ecosystem is an unexplored source for biotechnological applications. In this unique environment, endemic bacteria have the ability to thrive in the harsh environmental conditions (salinity and anaerobiosis), and act in the degradation of organic matter, promoting nutrient cycles. Thus, this study aimed to assess the cellulolytic activities of bacterial groups present in the sediment from a mangrove located in Ilha do Cardoso (SP, Brazil). To optimize the isolation of cellulolytic bacteria, enrichments in two types of culture media (tryptone broth and minimum salt medium), both supplemented with 5% NaCl and 1% of cellulose, were performed. Tests conducted with the obtained colonies showed a higher occurrence of endoglycolytic activity (33 isolates) than exoglycolytic (19 isolates), and the degradation activity was shown to be modulated by the presence of NaCl. The isolated bacteria were clustered by BOX-PCR and further classified on the basis of partial 16S rRNA sequences as Alphaproteobacteria, Gammaproteobacteria, Actinobacteria, Firmicutes or Bacteroidetes. Therefore, this study highlights the importance of studies focusing on the endemic species found in mangroves to exploit them as novel biotechnological tools for the degradation of cellulose.

| S-EPMC3910219 | biostudies-literature

Response surface optimization of ionic liquid pretreatments for maximizing cellulose nanofibril production.

Project description:Pretreatments with aqueous protic ionic liquid (PIL)-ethanolamine bis(oxalate) ([MEA][(HOA)(H2OA)]), combined with ultrasonic disintegration, were employed in cellulose nanofibril (CNF) production from pulp fibers. The optimization of pretreatment parameters is crucial for obtaining the maximum CNF yield. The response surface methodology was used to design the pretreatment conditions for preparing CNFs. This method consists of four factors: pretreatment time (A, 2-4 h), pretreatment temperature (B, 100-120 °C), liquid-to-solid ratio (C, 60-80 g g-1), and PIL content (D, 20-40%). The predicted CNF yield (Y) followed a quadratic multinomial regression equation represented by Y = 84.43 + 3.59A + 8.22B + 2.22C - 2.13D - 0.85AB + 2.83AC + 5.95AD + 0.43BC - 2.98BD + 4.25CD - 6.04A2 - 18.23B2 - 4.98C2 - 7.39D2. The regression equation exhibited high model fit to the experimental CNF yields as evidenced by a determination coefficient of 0.9764. Results showed that a maximum CNF yield of 86.2% was obtained in the case with the following conditions: pretreatment temperature of 112 °C, pretreatment time of 3.2 h, liquid-to-solid ratio of 83 g g-1, and PIL content of 29%. CNFs with high crystalline index (64.0%) and thermal stability (Tmax = 348 °C) were prepared. This work favors the development of low cost PIL-based pretreatment systems for the clean production of CNFs.

| S-EPMC10698732 | biostudies-literature

Drying of Pigment-Cellulose Nanofibril Substrates.

Project description:A new substrate containing cellulose nanofibrils and inorganic pigment particles has been developed for printed electronics applications. The studied composite structure contains 80% fillers and is mechanically stable and flexible. Before drying, the solids content can be as low as 20% due to the high water binding capacity of the cellulose nanofibrils. We have studied several drying methods and their effects on the substrate properties. The aim is to achieve a tight, smooth surface keeping the drying efficiency simultaneously at a high level. The methods studied include: (1) drying on a hot metal surface; (2) air impingement drying; and (3) hot pressing. Somewhat surprisingly, drying rates measured for the pigment-cellulose nanofibril substrates were quite similar to those for the reference board sheets. Very high dewatering rates were observed for the hot pressing at high moisture contents. The drying method had significant effects on the final substrate properties, especially on short-range surface smoothness. The best smoothness was obtained with a combination of impingement and contact drying. The mechanical properties of the sheets were also affected by the drying method and associated temperature.

| S-EPMC5456013 | biostudies-other

Comparison of Deep Eutectic Solvents on Pretreatment of Raw Ramie Fibers for Cellulose Nanofibril Production.

Project description:Deep eutectic solvents (DESs), featured as promising green solvents, were applied to examine their effectiveness in pretreating raw ramie fibers (RFs) for cellulose nanofibril (CNF) production. The pretreatment performance of three DESs, i.e., choline chloride-urea (CU), choline chloride-oxalic acid dihydrate (CO), and choline chloride-glycerol (CG), was evaluated based on chemical composition analysis and structural and morphological changes. CO attained the most dramatic morphological changes of RFs, followed by CG and CU. Its high structural disruption of RFs during the pretreatment process, shown in the results from scanning electron microscopy and atomic force microscopy, could be due to an outstanding ability to remove amorphous cellulose and noncellulosic components from raw RFs, confirmed by the results of chemical composition analysis, Fourier transform infrared spectroscopy, and X-ray diffractometry. Overall, this study provided an innovative and effective pretreatment process for fractionating raw cellulosic fibers, so as to promote the subsequent preparation of CNFs.

| S-EPMC7081644 | biostudies-literature

Aligning cellulose nanofibril dispersions for tougher fibers.

Project description:Nanocomposite materials made from cellulose show a great potential as future high-performance and sustainable materials. We show how high aspect ratio cellulose nanofibrils can be efficiently aligned in extrusion to fibers, leading to increased modulus of toughness (area under the stress-strain curve), Young's modulus, and yield strength by increasing the extrusion capillary length, decreasing its diameter, and increasing the flow rate. The materials showed significant property combinations, manifesting as high modulus of toughness (~28-31 MJ/m3) vs. high stiffness (~19-20 GPa), and vs. high yield strength (~130-150 MPa). Wide angle X-ray scattering confirmed that the enhanced mechanical properties directly correlated with increased alignment. The achieved moduli of toughness are approximately double or more when compared to values reported in the literature for corresponding strength and stiffness. Our results highlight a possibly general pathway that can be integrated to gel-spinning process, suggesting the hypothesis that that high stiffness, strength and toughness can be achieved simultaneously, if the alignment is induced while the CNF are in the free-flowing state during the extrusion step by shear at relatively low concentration and in pure water, after which they can be coagulated.

| S-EPMC5605715 | biostudies-literature

Stable Cellulose Nanofibril Microcapsules from Pickering Emulsion Templates.

Project description:Electrostatic attractions are essential in any complex formation between the nanofibrils of the opposite charge for a specific application, such as microcapsule production. Here, we used cationized cellulose nanofibril (CCNF)-stabilized Pickering emulsions (PEs) as templates, and the electrostatic interactions were induced by adding oxidized cellulose nanofibrils (OCNFs) at the oil-water interface to form microcapsules (MCs). The oppositely charged cellulose nanofibrils enhanced the solidity of interfaces, allowing the encapsulation of Nile red (NR) in sunflower oil droplets. Microcapsules exhibited a low and controlled release of NR at room temperature. Furthermore, membrane emulsification was employed to scale up the preparation of microcapsules with sunflower oil (SFO) encapsulated by CCNF/OCNF complex networks.

| S-EPMC9007535 | biostudies-literature

Dewatering Behavior of a Wood-Cellulose Nanofibril Particulate System.

Project description:The novel use of aqueous suspensions of cellulose nanofibrils (CNF) as an adhesive/binder in lignocellulosic-based composite manufacture requires the removal of a considerable amount of water from the furnish during processing, necessitating thorough understanding of the dewatering behavior referred to as "contact dewatering". The dewatering behavior of a wood-CNF particulate system (wet furnish) was studied through pressure filtration tests, centrifugation, and characterization of hard-to-remove (HR) water, i.e. moisture content in the wet furnish at the transition between constant rate part and the falling rate part of evaporative change in mass from an isothermal thermogravimetric analysis (TGA). The effect of wood particle size thereby particle specific surface area on the dewatering performance of wet furnish was investigated. Permeability coefficients of wet furnish during pressure filtration experiments were also determined based on Darcy's law for volumetric flow through a porous medium. Results revealed that specific particle surface area has a significant effect on the dewatering of wet furnish where dewatering rate significantly increased at higher specific particle surface area levels. While the permeability of the systems decreased over time in almost all cases, the most significant portion of dewatering occurred at very early stages of dewatering (less than 200?seconds) leading to a considerable increase in instantaneous dewatering when CNF particles come in contact with wood particles.

| S-EPMC6787033 | biostudies-literature

Cellulose nanofibril matrix drives the dynamic formation of spheroids.

Project description:Multicellular spheroids, which mimic the natural organ counterparts, allow the prospect of drug screening and regenerative medicine. However, their application is hampered by low processing efficiency or limited scale. This study introduces an efficient method to drive rapid multicellular spheroid formation by a cellulose nanofibril matrix. This matrix enables the facilitated growth of spheroids (within 48 h) through multiple cell assembly into size-controllable aggregates with well-organized physiological microstructure. The efficiency, dimension, and conformation of the as-formed spheroids depend on the concentration of extracellular nanofibrils, the number of assembled cells, and the heterogeneity of cell types. The above strategy allows the robust formation mechanism of compacted tumoroids and hepatocyte spheroids.

| S-EPMC10522563 | biostudies-literature

Strength and Water Interactions of Cellulose I Filaments Wet-Spun from Cellulose Nanofibril Hydrogels.

Project description:Hydrogels comprising cellulose nanofibrils (CNF) were used in the synthesis of continuous filaments via wet-spinning. Hydrogel viscosity and spinnability, as well as orientation and strength of the spun filaments, were found to be strongly affected by the osmotic pressure as determined by CNF surface charge and solid fraction in the spinning dope. The tensile strength, Young's modulus and degree of orientation (wide-angle X-ray scattering, WAXS) of filaments produced without drawing were 297 MPa, 21 GPa and 83%, respectively, which are remarkable values. A thorough investigation of the interactions with water using dynamic vapour sorption (DVS) experiments revealed the role of sorption sites in the stability of the filaments in wet conditions. DVS analysis during cycles of relative humidity (RH) between 0 and 95% revealed major differences in water uptake by the filaments spun from hydrogels of different charge density (CNF and TEMPO-oxidised CNF). It is concluded that the mechanical performance of filaments in the presence of water deteriorates drastically by the same factors that facilitate fibril alignment and, consequently, enhance dry strength. For the most oriented filaments, the maximum water vapour sorption at 95% RH was 39% based on dry weight.

| S-EPMC4964603 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data