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This study evaluated the inhibitory effect and mitigation strategy of dodecyl dimethyl benzyl ammonium chloride (DDBAC) suppression on anaerobic digestion. With the 12 h-suppression, only 16.64% of anaerobes were alive, and acetotrophic methanogens were significantly inhibited. As for batch test, DDBAC suppression significantly prolonged the start-up of systems and decreased the biogas production. In cellulose semi-continuous digestion process, the DDBAC suppression induced volatile fatty acids accumulation and pH decrease. However, the biochar amended reactor effectively mitigated the DDBAC suppression and achieved 370.5 mL/d·g-chemical-oxygen-demand biogas production. Moreover, 17.8% more protein in extracellular polymeric substances was secreted as the bio-barrier to defense the DDBAC suppression. Furthermore, microbial analysis showed that biochar addition selectively enriched directed interspecies electron transfer (DIET) participant bacteria (Anaerolineaceae and Syntrophomonas) and methanogens (Methanosaeta and Methanobacterium). Meanwhile, the potential metabolic pathway analysis showed that the abundance of amino acids and energy metabolism were increased 28% and 8%, respectively. The abundance of encoding enzyme related to hydrogenotrophic and acetotrophic methanogenesis enriched 1.88 times and 1.48 times, respectively. These results showed the performance and mechanisms involved in DIET establishment with ethanol stimulation biochar addition., (Copyright © 2022. Published by Elsevier Ltd.)

O/W Pickering emulsions containing oil phase with different volume fractions (50-75 v%) were facilely prepared by using bacterial cellulose nanofibrils (BCNFs) alone. The effect of oil phase volume, storage time on the surface coverage, and coalescence rate of the Pickering-MIPEs and HIPEs (medium internal phase emulsions/high internal phase emulsions) were investigated. The Pickering-MIPEs/HIPEs exhibited excellent physical stability and low coalescence rate with droplet size varying from 32 to 91 μm. The increasing of particle contents could obviously decrease the droplet size and enhance the stability of the emulsions by strengthening the network structure and increasing the steric hindrance. The result of rheology analysis confirmed the formation of a three-dimensional network, endowing the exceptional stability of the emulsions. The emulsions revealed superb stability against a wide temperature (4-50 °C) range and salt condition (0-100 mM). This novel eco-friendly Pickering-MIPEs and HIPEs would provide great opportunities for their effective utilization in green-labelled food industry., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The antimicrobial nisin peptide was grafted to the 2,3-dialdehyde cellulose through Schiff's base reaction. The obtained peptidopolysaccharide films had the denser microstructure, lower water holding capacity, and increased mechanical properties than the pristine cellulose film. The peptidopolysaccharide films exhibited promising antibacterial activity toward Gram-positive and Gram-negative bacteria, and the ability to induce bacteriostasis of the N-3 peptidopolysaccharide film was four orders of magnitude higher than that of pure cellulose film. In an extended application, the peptidopolysaccharide antibacterial films were used as packaging materials for fresh pork, the results indicated that the peptidopolysaccharide films readily killed the adhered bacteria upon contact, and the N-3 peptidopolysaccharide film extended the shelf-life of the fresh pork at least for six days as compared with polyethylene wrap. Therefore, these peptidopolysaccharides films represent good potential as a green food packaging material., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In order to obtain a safe and biodegradable material with antimicrobial properties from cellulose for food packaging, we presented a facile way to graft chitosan onto the oxidized cellulose films. The obtained films had a high transparent property of above 80% transmittance, excellent barrier properties against oxygen and antimicrobial properties against Escherichia coli and Staphylococcus aureus. The antimicrobial properties, mechanical properties, and water vapor permeability of composites are essential characteristics in determining their applicability as food-packaging materials. Moreover, using a sausage model, it was shown that the composites exhibited better performance than traditional polyethylene packaging material and demonstrated good potential as food packaging materials. The results presented a new insight into the development of green materials for food packaging., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

A facile method had been applied to introduce hydrophobic properties to cellulose materials by incorporation of polyurethane acrylate (PUA) prepolymers into the porous structured cellulose matrix through dip-coating; then, PUA prepolymers were cured around interconnected cellulose fibers under UV light, encapsulating a cellulose matrix with a hydrophobic polymer shell. The characterization of the composite films confirmed the success of the heterogeneous modification, and the chemical structure of the cellulose matrix was preserved. The composite films integrated the merits of cellulose and PUA resin, but the highly hydrophilic behavior of cellulose has been reduced. Contact angle measurements with water demonstrated that the composite films had obvious hydrophobic properties and an obvious reduction in the water uptake and the permeability toward water vapor gas at different relative humidity was also observed. The transmittance of the composite films at 550 nm was about 85%. The thermal and mechanical properties of the composite films were improved when compared with that of PUA resin. The obtained composite based on cellulose and UV curing technology was a good choice for the development of biomass materials with modified surface properties.

Graphene oxide, flat carbon nanosheets, has generated extensive interests in many areas of science and engineering due to its unprecedented physical and chemical properties. With the development of wide-scale applicability including facile synthesis and high yield, this exciting material is ready for practical applications. In this work, fully exfoliated graphene oxide nanosheets were introduced into cellulose matrix through a facial pathway. A significant increase in the elongation at break of the composites was observed; that was, a 120% improvement in the tensile strength and a nearly 3 times increase in elongation at break were achieved for the composite films with GO content of 0.27 vol%. The microstructures of the regenerated cellulose films before and after loading of GO nanosheets were characterized by using SEM and TEM. Furthermore, the theoretical simulation from Young’s modulus of the composite films indicated that the GO nanosheets had unidirectional arrangement tendency rather than random dispersion in cellulose matrix, which contributed to the improvement in the elongation of the composites, which was supported by the SEM results of the cross-section of the broken composite. [ABSTRACT FROM AUTHOR]

Abstract In this work, high pressure homogenization (HPH) was applied to alter the physical size of bacterial cellulose, and the obtained bacterial cellulose nanofibrils (BCNFs) with different size were used as stabilizers for O/W Pickering emulsions. The average width of the BCNFs was decreased from 127 to 97 nm with the increasing the homogenized times from 10 to 80 times at 750 Bar, and the obtained BCNFs suspensions was pseudoplastic fluid and exhibited a typical shear thinning behavior. The physical size of the BCNFs had an obvious influence on their emulsifying capacity, and the surface coverage ratio of the emulsion droplets was increased from 0.63 to 9.77 with the changing the volume of oil and solid content of BCNFs. Moreover, the temperature, ionic strength and pH had insignificant influence on the stability of the emulsion. It suggested that the flexible BCNFs played an important role in the stabilization of the emulsions, and the higher content of BCNFs increased the intermolecular noncovalent "physical" cross-links. Moreover, stable medium-internal-phase-emulsions (MIPEs) could also be fabricated by using BCNFs as stabilizers. Graphical abstract Image Highlights • HPH process was used to change the physical sizes of bacterial nanocellulose. • The effect of the physical sizes of bacterial nanocellulose on the performance of the emulsions had been clarified. • Stable medium-internal-phase-emulsionscould could be prepared by using bacterial nanocellulose. [ABSTRACT FROM AUTHOR]

In this study, the effect of bacterial cellulose nanofibrils (BCNF) surface charge density on the emulsification capacity of gelatin (GLT)/BCNF mixtures was investigated. Emulsions with 50 v% oil phase were co-stabilized by GLT and BCNFs (surface charge densities varied from 0.34 to 1.16 mmol/g) at pH 7.0 (GLT and BCNFs were negatively charged) and pH 4.7 (electrostatic equilibrium point for all GLT/BCNF mixtures). At pH 7.0, as BCNF surface charge density increased, the oil-water interfacial tension was decreased. Thus, the emulsion droplet size was reduced from 14.24 to 13.51 μm when the BCNF surface charge density was improved from 0.34 to 1.16 mmol/g. Additionally, the emulsion stability was significantly improved by the addition of highly-charged BCNF due to the increased electrostatic repulsion between dispersed droplets. At pH 4.7, the highest level of attractive electrostatic interaction was observed for GLT and BCNF with a surface charge density of 1.16 mmol/g (BCNF 1.16). Thus, the GLT/BCNF 1.16 suspension exhibited the highest viscoelastic modulus. At pH 4.7, the stability of GLT/BCNFs co-stabilized emulsions was improved by increasing BCNF surface charge density due to the enhanced viscosity. The emulsions prepared with GLT and BCNFs with surface charge density higher than 0.66 mmol/g at pH 4.7 could keep stable without creaming for 30 d. Furthermore, the GLT/BCNF 1.16, with the most remarkable emulsion stabilizing capacity, was successfully applied to prepare high internal phase emulsions with a more stable and higher viscoelastic behavior. This study was meaningful for the regulation of emulsion stability and rheological property. [Display omitted] • BCNFs with different surface charge densities were prepared by TEMPO oxidation. • Emulsions were prepared with GLT/BCNF mixtures at pH 7.0 and 4.7. • The interfacial adsorption of GLT/BCNF was influenced by BCNF surface charge density. • Emulsion stability was improved by the enhancement of BCNF surface charge density. [ABSTRACT FROM AUTHOR]

A new strategy to fabricate edible oleogels had been developed in this work, using natural cellulose particles as gelator and water as secondary fluid. Effect of the content of cellulose particles and second fluid on the formation of oleogels were investigated, and a qualitative phase diagram was constructed. Consideration has also focused on the influence of second fluid (ionic strength, pH and sucrose). Results showed that the cellulose particles could form a network in oil phase through the capillary force originated from the secondary fluid. A denser and more uniform network provided the oleogels higher centrifugal stability against oil loss. The viscoelastic properties of oleogels could be enhanced by increasing the ionic strength (10–100 mM), sucrose concentration (10–20 wt%) and pH value (2.0–5.0) of the second fluid. These results suggested that the capillary force of the gel network could be modulated by the composition and pH of secondary fluid. The considerable gel strength and economical manufacturing process give the oleogels great application potential. [Display omitted] • Edible oleogels were prepared using a simple and economical process. • Using natural cellulose particles as gelator and water as the second fluid. • Cellulose particles could form a network in oil phase through the capillary force. • Strength of the oleogels could be modulated by the water phase. [ABSTRACT FROM AUTHOR]