Carboxymethyl Bacterial Cellulose Research Articles

Antibacterial Films Made of Bacterial Cellulose.

Bacterial cellulose (BC) is naturally degradable, highly biocompatible, hydrophilic, and essentially non-toxic, making it potentially useful as a base for creating more sophisticated bio-based materials. BC is similar to plant-derived cellulose in terms of chemical composition and structure but has a number of important differences in microstructure that could provide some unique opportunities for use as a scaffold for other functions. In this study, bacterial cellulose was alkylated and then esterified to produce a carboxymethyl bacterial cellulose (CMBC) that was then used to produce six different composite films with potential antibacterial properties. The films were assessed for antibacterial activity against Staphylococcus aureus and Escherichia coli, pyrolysis characteristics using thermogravimetric analysis (TGA), microstructure using scanning electron microscopy (SEM), and mechanical properties. The addition of nano-silver (nano-Ag) markedly improved the antimicrobial activity of the films while also enhancing the physical and mechanical properties. The results indicate that the three-dimensional reticulated structure of the bacterial cellulose provides an excellent substrate for scaffolding other bioactive materials. Thus, the nano-BC was added into the CMBC/nano-Ag composites furthermore, and then the antibacterial and mechanical properties were improved 44% for E. coli, 59% for S. aureus, and 20% for tensile strength, respectively.

The Improved Properties of Carboxymethyl Bacterial Cellulose Films with Thickening and Plasticizing

This study aims to improve the thermal stability and mechanical properties of carboxymethyl bacterial cellulose (CMBC) composite films. Experiments were conducted by preparing bacterial cellulose (BC) into CMBC, then parametrically mixing sodium alginate/starch/xanthan gum/gelatin and glycerin/sorbitol/PEG 400/PEG 6000 with CMBC to form the film. Scanning electron microscopy, X-ray diffractometry, infrared spectroscopy, mechanical tests, and thermogravimetric analysis showed that the composite films had better mechanical properties and thermal stability with the addition of 1.5% CMBC (% v/v), 1% sodium alginate, and 0.4% glycerin. Tensile strength was 38.13 MPa, the elongation at break was 13.4%, the kinematic viscosity of the film solution was 257.3 mm2/s, the opacity was 4.76 A/mm, the water vapor permeability was 11.85%, and the pyrolysis residue was 45%. The potential causes for the differences in the performance of the composite films were discussed and compared, leading to the conclusion that CMBC/Sodium alginate (SA)/glycerin (GL) had the best thermal stability and mechanical properties.

Dual-charge bacterial cellulose as a potential 3D printable material for soft tissue engineering

The surface charge of anionic carboxymethylated bacterial cellulose (CMBC) was tailored using chitosan. to ionically bond to the carboxyl groups on the surface of the CMBC. This cationic surface functionalization significantly affected the physical properties and overall net charge of the resulting material. Both the negatively and positively charged BC were characterized, then combined and formed into composites in three separate ratios, as well as extruded by a 3D printing system. The chitosan functionalized CMBC (CMBC (+)) demonstrated light refraction capabilities, larger particle size and positive charge, in contrast to the unfunctionalized negatively charged CMBC (CMBC (−)).

Scalable bacterial cellulose biofilms with improved ion transport for high osmotic power generation

The manufacture of large-sized material with tunable nanochannel size and high ion selectivity is always a challenge for osmotic power generation. Herein, we develop negatively charged carboxymethyl bacterial cellulose membranes (BC-CMC) and positively charged chitosan quaternary ammonium bacterial cellulose membranes (BC-HACC) with adjustable charge density and nanochannel size by in situ culture. The scalable membranes are suitable for rapidly ion selective transmission process. When applying the charged BC membranes for an osmotic energy harvesting device, an output power density of 2.25 W m −2 can be reached. Further connecting 15 units of the charged BC device, the output voltage can reach up to 2.53 V, which can directly power the electronic devices. This work highlights the advantage of large-scale preparation by the biosynthesis method, which can simultaneously tune the surface properties and nanochannel size of BC to regulate the ion transport behavior. We offer an easy and scalable method to obtain low-cost membranes for high osmotic energy conversion device, providing the feasibility for their large-scale application. • This paper offers a simple in situ biosynthetic modification to obtain charged BC membranes. • The scalable membranes are suitable for ion selective transmission process. • The BC-RED device can achieve an output power density of 2.25 W m −2 . • Our work develops low-cost, large-scale charged BC membranes potential in practical osmotic energy collection.

Effect of Monochloroacetic Acid on Properties of Carboxymethyl Bacterial Cellulose Powder and Film from Nata de Coco.

Nata de coco has been used as a raw material for food preparation. In this study, the production of carboxymethyl cellulose (CMC) film from nata de coco and the effect of monochloroacetic acid on carboxymethyl bacterial cellulose (CMCn) and its film were investigated. Bacterial cellulose from nata de coco was modified into CMC form via carboxymethylation using various concentrations of monochloroacetic acid (MCA) at 6, 12, 18, and 24 g per 15 g of cellulose. The results showed that different concentrations of MCA affected the degree of substitution (DS), chemical structure, viscosity, color, crystallinity, and morphology of CMCn. The optimum treatment for carboxymethylation was found using 24 g of MCA per 15 g of cellulose, which provided the highest DS at 0.83. The morphology of CMCn was related to DS value; a higher DS value showed denser and smoother surface than nata de coco cellulose. The various MCA concentrations increased the mechanical properties (tensile strength and percentage of elongation at break) and water vapor permeability of CMCn, which were related to the DS value.

Carboxymethyl Bacterial Cellulose from Nata de Coco: Effects of NaOH.

Bacterial cellulose from nata de coco was prepared from the fermentation of coconut juice with Acetobacter xylinum for 10 days at room temperature under sterile conditions. Carboxymethyl cellulose (CMC) was transformed from the bacterial cellulose from the nata de coco by carboxymethylation using different concentrations of sodium hydroxide (NaOH) and monochloroacetic acid (MCA) in an isopropyl (IPA) medium. The effects of various NaOH concentrations on the degree of substitution (DS), chemical structure, viscosity, color, crystallinity, morphology and the thermal properties of carboxymethyl bacterial cellulose powder from nata de coco (CMCn) were evaluated. In the carboxymethylation process, the optimal condition resulted from NaOH amount of 30 g/100 mL, as this provided the highest DS value (0.92). The crystallinity of CMCn declined after synthesis but seemed to be the same in each condition. The mechanical properties (tensile strength and percentage of elongation at break), water vapor permeability (WVP) and morphology of CMCn films obtained from CMCn synthesis using different NaOH concentrations were investigated. The tensile strength of CMCn film synthesized with a NaOH concentration of 30 g/100 mL increased, however it declined when the amount of NaOH concentration was too high. This result correlated with the DS value. The highest percent elongation at break was obtained from CMCn films synthesized with 50 g/100 mL NaOH, whereas the elongation at break decreased when NaOH concentration increased to 60 g/100 mL.

Carboxymethylated bacterial cellulose: An environmentally friendly adsorbent for lead removal from water

Carboxymethylated bacterial cellulose (CMBC) was synthesized under controlled reaction condition to provide a material with a degree of substitution (DS) that guarantees that the characteristic water insolubility of cellulose is retained (DS = 0.17). The CMBC synthesized was fully characterized by conductometric titration, infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, thermogravimetric analysis and solubility assays. The suitability of the produced CMBC for lead removal from water was evaluated. Experimental isotherm data were fitted to different models of sorption isotherms: Langmuir, Freundlich, Dubinin-Radushkevich, and Frumkin, with Langmuir equation resulting in the best fit. Kinetic data were also adjusted to pseudo-first-order and pseudo-second-order models and results undoubtedly showed that the pseudo-second-order kinetic equation was the one that most appropriately described the lead adsorption of CMBC, indicating that lead is adsorbed on CMBC predominantly by chemical interaction. The breakthrough curve was fitted to different models: Bohart-Adams, Clark and Modified Dose-Response, being the Bohart-Adams equation the one that gave the best fit. Desorption studies were carried out in order to know the technical feasibility of the reuse of CMBC. Almost 96% of the retained lead was eluted in just 20 mL, and the CMBC lifetime was over 50 adsorption/desorption cycles. Overall, results obtained suggest that the CMBC herein synthesized may result in an alternative economic and environmentally friendly lead adsorbent for water treatment.

Protein adsorption behaviors of carboxymethylated bacterial cellulose membranes

Carboxymethylated bacterial cellulose (CBC) membranes with different degrees of substitution (DS) were prepared by surface carboxymethylation of bacterial cellulose, which were characterized by FTIR, contact angles and zeta potential. Both the contact angels and zeta potentials increased with the increase of degrees of carboxymethylation. Protein adsorption behaviors of CBC membranes were investigated with bovine serum albumin (BSA) as model protein and the adsorption quantity increased gradually with the increase of the DS. The protein adsorption was not only governed by the chemical structure of CBC, but also by the electrostatic interaction between CBC and BSA. The protein was found to be adsorbed on CBC membrane at pH lower its isoelectric point (pI) while no protein was adsorbed at pH above its pI. The protein adsorption on the CBC membranes was also characterized by scanning electron microscopy (SEM).

Preparation and characteristic of a sodium alginate/carboxymethylated bacterial cellulose composite with a crosslinking semi‐interpenetrating network

ABSTRACTA novel ionic crosslinking sodium alginate (SA)/carboxymethylated bacterial cellulose (CM‐BC) composite with a semi‐interpenetrating polymer network (semi‐IPN) structure was developed in this study. The composite was prepared through the blending of an SA gel with CM‐BC then crosslinking by Ca2+ followed by a freeze‐drying process. Scanning electron microscopy showed the composite matrix organized in a three‐dimensional network of CM‐BC interpenetrated against SA molecular chains with a quantity of calcium alginate microspheres upon the surface. The swelling ratios of the composite were enhanced by 183, 198, and 212% with the supplementation of CM‐BC weight fractions of 25, 50, and 75%, respectively; the swelling ratios changed with changing pH. The tensile modulus, tensile strength, and elongation at break of SA were enhanced by 165, 152, and 188%, respectively, with the addition of 50 wt % CM‐BC. This study demonstrated that the semi‐IPN structure dramatically changed the swelling and mechanical properties of the composite, and the semi‐IPN will be a promising candidate for biomedical applications such as wound dressings and skin tissue engineering. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39848.

Biosynthesis of Carboxymethylated Bacterial Cellulose Composite for Wound Dressing

A novel bacterial cellulose (BC) composite (carboxymethylated-bacterial cellulose, CM-BC) was synthesized by Acetobacter xylinum by adding water-soluble carboxymethylated cellulose (CMC) in the culture medium. FTIR results showed that CM-BC is obtained by the incorporation of CMC in the network of BC. Water-holding capacity and water vapor transmission rates (WVTR) of CM-BC and BC are determined. The WVTR of CM-BC is comparable to that of BC, but the water-holding capacity of CM-BC is improved compared with BC. Tensile strengths measurement results showed that the fracture stress of CM-BC is higher than that of BC, indicating that CM-BC have more potential wound dressing applications than BC.

Fermentative Production and Characterization of Carboxymethyl Bacterial Cellulose Using Date Syrup

Fermentative Production and Characterization of Carboxymethyl Bacterial Cellulose Using Date Syrup

Carboxymethylated-bacterial cellulose for copper and lead ion removal

Carboxymethylated-bacterial cellulose (CM-BC) was synthesized by Acetobacter xylinum by adding water-soluble carboxymethylated cellulose (CMC) in the culture medium. The CM-BC was examined for the removal of copper and lead ions from aqueous solution compared with BC. The effects of performance parameters such as pH, adsorbent dose, contact time on copper and lead ion adsorption were analyzed. Both BC and CM-BC show good adsorption performance at optimized pH 4.5. Compared with BC, CM-BC performs better adsorption, with the value of 9.67 mg (copper)/g, 22.56 mg (lead)/g for BC and 12.63 mg (copper)/g, 60.42 mg (lead)/g for CM-BC, respectively. The adsorption rate closely follows pseudo-second-order rate model and the adsorption isotherm data well follows the Langmuir model.

Biosynthesis of hetero-polysaccharides by Acetobacter xylinum - Synthesis and characterization of metal-ion adsorptive properties of partially carboxymethylated cellulose

Biological reconstruction of water-soluble carboxymethylated cellulose (CMC; D.S. =0.47) has been achieved by culturing Acetobacter xylinum in medium containing CMC and d-glucose to give a novel hetero-polysaccharide having a carboxymethyl function. The novel extracellular polysaccharide, carboxymethylated-bacterial cellulose (CM-BC), had an ion exchange ability with enhanced specific adsorption for lead and uranyl ions compared to the original CMC and bacterial cellulose. The contribution of the hydroxy group at C-2 was confirmed by applying carboxymethylated chitin, which possesses acetamido group at C-2 of the glucose residue, as the carbon source of the incubation.