Bacterial Cellulose Materials Research Articles

Biosynthesis and characterization of antibacterial bacterial cellulose composite membrane composed of montmorillonite and exopolysaccharides

Bacterial cellulose (BC), as a natural renewable polymer material, has the advantages of porous nanonetwork structure, high degree of polymerization, high purity, high crystallinity, excellent mechanical properties and biocompatibility. However, BC lacks antibacterial properties, which leads to the limitation of BC material in food packaging and medical materials. In this study, a new antibacterial material using the combination of montmorillonite (MMT), BC and exopolysaccharides (EPS) produced by Weissella confusa H2 was synthesized. Fourier infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) analysis showed that BC-EPS, BC-MMT and BC-EPS-MMT composite membranes conformed to the typical type I cellulose structure. Compared to BC membrane, scanning electron microscopy (SEM) showed that the porosity of BC-EPS, BC-MMT and BC-EPS-MMT composite membranes was low and compact. The physical properties of BC-EPS, BC-MTT and BC-EPS-MTT composite membranes showed lower water vapor transmittance. The BC-MTT and BC-EPS-MTT composite membranes exhibit a lower swelling ratio in 120 min. The thermal properties show that BC-EPS, BC-MTT and BC-EPS-MTT composite membranes have higher thermal stability (352 °C, 310 °C, 314 °C). Additionally, both BC-MMT and BC-EPS-MMT demonstrated strong inhibitory effects against various bacterial strains, including Staphylococcus aureus, Escherichia coli, Salmonella paratyphi A, and Bacillus subtilis. The exceptional properties exhibited by composite membranes establishes them as a highly promising option in the field of food packaging and medical material applications.

Evaluation of the antibacterial activity of nano berberine adsorbed bacterial cellulose material

Berberine can be considered a natural antibiotic plant with strong antibacterial and antifungal activities. The pr oblem of bioavailability and poor solubility can be overcome by formulating berberine at nanoparticles, which opens up a vast range of applications. In this study, berberine nanoparticles (BerNPs) were adsorbed on bacterial cellulose forming a composite with the potential for antibacterial material. The pr operties of BerNPs and before and after BerNPs adsorption were analysed by FE-SEM, XRD, and FT-IR methods. The antibacterial activity of BerNPs and its composite was examined invitro by the co-culture method with Escherichiacoli and Streptococcus pyogenes. The results indicated that BerNPs exhibited gr eat antibacterial pr operties against E. coliand S. pyogenes. The optimum capacity of loading BerNPs (50-60 nm) above the biological cellulose was after 2 hours of soaking. The against E. coli and S. pyogenes was over 80%.

Characterization of carbon quantum dots obtained through citric acid pyrolysis

Carbon quantum dots (CQDs) were produced through citric acid (CA) pyrolysis. For the first time, we searched for the optimum CA pyrolysis duration and temperature. As a basic quality criterion of quantum dots, photoluminescence quantum yield (QY) was chosen. For this purpose, the pyrolysis products were analysed with UV–Vis spectroscopy and fluorescence (FL) spectroscopy. The optimum pyrolysis time was accepted to be 240 min, whereas the optimum pyrolysis temperature was approved as 200 °C. The pyrolysis products obtained at the optimum conditions were further subjected to dialysis. Finally, the purified CQDs were characterised with FL spectroscopy, transmission electron microscopy, dynamic light scattering, Raman spectroscopy, and Fourier transform infra-red spectroscopy. The produced CQDs were shown to be stable in water solution. Their PL QY (6.1%) was decreased to 1.2% after CQDs exposure to daylight for 90 days. Luminescent polymer composites were produced when CQDs were embedded in the poly(vinyl alcohol) and bacterial cellulose matrices. The prepared composites can be used for fabrication of transparent, flexible, and luminescent films and for production of anti-counterfeiting paper for confidential documents, labels, and banknotes.

Polyphenyltriazoles on Kombucha‐Derived Bacterial Cellulose: Synthesis, Structural Evaluation and Hydrophobicity

AbstractBacterial cellulose‐based materials have diverse applications as leather‐like materials, wound‐healing materials, and optoelectronic materials etc. Particularly, functionalization by polymer or organic compounds can help improve specific properties to diversify application areas. In this work, we reported a facile approach to functionalize Kombucha‐derived bacterial cellulose (BC) by AB‐type “Graft Through” click polymerization reaction. Since by this technique, the polymer was anchored on the surfaces as well as was produced in solution, and it provided the flexibility of detailed characterization on the surface as well as in a solution. Apart from standard spectroscopic characterization techniques, multinuclear solid‐state 13C, 29Si, and 15N NMR spectroscopic studies were undertaken extensively for finding the detailed structural information unambiguously. Thermal analysis, X‐Ray Diffraction analysis, and Small Angle Scattering (SAXS) was undertaken to understand the crystallinity and fibrous properties of the bacterial cellulose materials, while various microscopic analyses were undertaken for morphological studies. Those are particularly helpful in understanding the hydrophobicity of the materials an essential parameter for diversifying the application areas of the materials.

In-situ CBM3-modified bacterial cellulose film with improved mechanical properties

Cellulose materials have poor wet strength and are susceptible to acidic or basic environments. Herein, we developed a facile strategy to modify bacterial cellulose (BC) with a genetically engineered Family 3 Carbohydrate-Binding Module (CBM3). To assess the effect of BC films, water adsorption rate (WAR), water holding capacity (WHC), water contact angle (WCA), and mechanical and barrier properties were determined. The results showed that CBM3-modified BC film exhibited significant strength and ductility improvement, reflecting improved mechanical properties of the film. The excellent wet strength (both in the acidic and basic environment), bursting strength, and folding endurance of CBM3-BC films were due to the strong interaction between CBM3 and fiber. The toughness of CBM3-BC films reached 7.9, 28.0, 13.3, and 13.6 MJ/m3, which were 6.1, 1.3, 1.4, and 3.0 folds over the control for conditions of dry, wet, acidic, and basic, respectively. In addition, its gas permeability was reduced by 74.3 %, and folding times increased by 56.8 % compared with the control. The synthesized CBM3-BC films may hold promise for future applications in food packaging, paper straw, battery separator, and other fields. Finally, the in situ modification strategy used to BC can be successfully applied in other functional modifications for BC materials.

Developing a holistic sensory evaluation three-part method for textiles and apparel: a practical application for novel materials and products

Purpose This study aims to propose and demonstrate a practical application of a new three-part holistic sensory evaluation (HSE) method for textiles and apparel based on the senses of sight, touch, hearing and smell. HSE method development was carefully documented, described and successfully applied to evaluate sensory characteristics and consumer perceptions and acceptance of bacterial cellulose (BC), a novel sustainable material for apparel. Design/methodology/approach In Part One of the HSE method, research participants described the material in their own words based on the senses of sight, touch, hearing and smell. In Part Two, they rated the intensities and their linking for 25 predetermined attributes describing BC. Part Three measured participants’ overall liking of BC and its perceived suitability for apparel and accessories. Findings Application of the HSE method resulted in an in-depth understanding of BC material. Areas for material improvements and positive characteristics were identified, providing direction for further development. Consumers found BC suitable for accessories and outer-layer garments but not for apparel. Originality/value Sensory evaluation of textiles and apparel has traditionally focused on the senses of touch and sight. The new HSE method allows evaluating the full range of sensory characteristics of materials/products and holistically assessing consumer perceptions. The method is especially useful for novel materials and wearable technology. BC has gained increased interests as a novel sustainable material, yet consumer studies have been lacking. This study reports a comprehensive evaluation of BC material from consumer perspective.

Structural properties of optically clear bacterial cellulose produced by Komagataeibacter hansenii using arabitol.

Bacterial cellulose (BC) exhibits beneficial properties for use in biomedical applications but is limited by its lack of tunable transparency capabilities. To overcome this deficiency, a novel method to synthesize transparent BC materials using an alternative carbon source, namely arabitol, was developed. Characterization of the BC pellicles was performed for yield, transparency, surface morphology, and molecular assembly. Transparent BC was produced using mixtures of glucose and arabitol. Zero percent arabitol pellicles exhibited 25% light transmittance, which increased with increasing arabitol concentration through to 75% light transmittance. While transparency increased, overall BC yield was maintained indicating that the altered transparency may be induced on a micro-scale rather than a macro-scale. Significant differences in fiber diameter and the presence of aromatic signatures were observed. Overall, this research outlines methods for producing BC with tunable optical transparency, while also bringing new insight to insoluble components of exopolymers produced by Komagataeibacter hansenii.

Biosorption of bioactive compounds in bacterial nanocellulose: Mechanisms and physical-chemical properties

Bacterial cellulose (BC) is a biomaterial produced by Gluconacetobacter xylinus, with wide applicability in different areas, such as biomedical, pharmaceutical, and food. BC production is usually carried out in a medium containing phenolic compounds (PC), such as teas, however, the purification process leads to the loss of such bioactive. Thus, the innovation of this research consists of the reincorporation of PC after the purification of the BC matrices through the biosorption process. In this context, the effects of the biosorption process in BC were evaluated to maximize the incorporation of phenolic compounds from a ternary mixture of hibiscus (Hibiscus sabdariffa), white tea (Camellia sinensis), and grape pomace (Vitis labrusca). The biosorbed membrane (BC-Bio) showed a great concentration of total phenolic compounds (TPC = 64.89 mg L−1) and high antioxidant capacity through different assays (FRAP: 130.7 mg L−1, DPPH: 83.4 mg L−1, ABTS: 158.6 mg L−1, TBARS: 234.2 mg L−1). The physical tests also indicated that the biosorbed membrane presented high water absorption capacity, thermal stability, low permeability to water vapor and improved mechanical properties compared to BC-control. These results indicated that the biosorption of phenolic compounds in BC efficiently increases bioactive content and improves physical membrane characteristics. Also, PC release in a buffered solution suggests that BC-Bio can be used as a polyphenol delivery system. Therefore, BC-Bio is a polymer with wide application in different industrial segments.

MnO2 nanoflowers loaded on three-dimensional interconnected bacterial cellulose-derived honeycomb-like carbon for high-performance supercapacitors

Bacterial cellulose (BC) has been considered to be an ideal substrate for electrode materials due to its characteristics of natural abundance and wide range of sources. Controlling the microscopic morphology of electrode materials can enhance the capacity of BC materials effectively. However, most of the remaining BC derived carbon exhibit morphology of fibers, and the effective method for porous morphology need further studies, let alone the electrochemical properties of the materials used as electrode active material. Here, we prepared 3D interconnected mesoporous honeycomb-like carbon by pyrolysis of purified bacterial cellulose (3DIHBC). Then MnO2 with flower-like morphology was then grown on the 3D carbon with a simple hydrothermal method. The prepared 3DIHBC/MnO2 electrode delivers a reversible specific capacitance of 170F g−1 at 1 A g−1, and also retains 76% impressive long-term cycling stability after 5000 cycles at 10 A g−1 in an aqueous electrolyte. This is a highly cost-effective method for the preparation of 3DIHBC/MnO2 composites, and the rational use of cheap biomass carbon can improve the drawback of poor cyclic stability of metal oxides, which is important for environmental protection and mass-producible energy storage.

Bacterial cellulose: A highly versatile nanomaterial.

Bacterial cellulose: A highly versatile nanomaterial.

Insights into Hierarchical Structure–Property–Application Relationships of Advanced Bacterial Cellulose Materials

AbstractBacterial cellulose (BC) is an environmentally friendly biomaterial that is widely investigated because it possesses a unique hierarchical nanofiber network structure as well as extraordinary performance. In this review, the formation of the BC hierarchical nanofiber network structure from the perspective of biosynthesis is illustrated based on its basic chemical and crystal structure. Moreover, the design and processing of BC‐based advanced materials through biosynthesis, physical, and/or chemical modification are also reviewed. The intrinsic characteristics of BC, derived from its hierarchical structure, are analyzed to understand its structure–property–application relationships. The applications of advanced BC‐based materials are reviewed, such as high‐strength structural materials utilizing the properties of nanofibers, energy conversion and storage, bioelectronic interfaces, environmental remediation, and thermal management applications utilizing the ion transport properties and 3D network structures of these materials. In addition, the authors also offer their opinions and potential future research directions for sustainably developing BC‐based materials.

Biofilm inspired fabrication of functional bacterial cellulose through ex-situ and in-situ approaches

Bacterial cellulose (BC) has been explored for use in a range of applications including tissue engineering and textiles. BC can be produced from waste streams, but sustainable approaches are needed for functionalisation. To this end, BslA, a B. subtilis biofilm protein was produced recombinantly with and without a cellulose binding module (CBM) and the cell free extract was used to treat BC either ex-situ, through drip coating or in-situ, by incorporating during fermentation. The results showed that ex-situ modified BC increased the hydrophobicity and water contact angle reached 120°. In-situ experiments led to a BC film morphological change and mechanical testing demonstrated that addition of BslA with CBM resulted in a stronger, more elastic material. This study presents a nature inspired approach to functionalise BC using a biofilm hydrophobin, and we demonstrate that recombinant proteins could be effective and sustainable molecules for functionalisation of BC materials.

Bacterial Cellulose Production by Komagateibacter xylinus with the Use of Enzyme-Degraded Oligo- and Polysaccharides as the Substrates

Bacterial cellulose (BC) is a unique biopolymer synthesised by many bacteria as a critical element of their biofilm matrix. The most known and efficient producers of BC are bacteria from the genus of Komagataeibacter. Bacterial cellulose, with its unique properties, high crystallinity, mechanical strength, and unprecedented ability to hold water, is an object of interest in many industries. Despite the enormous efforts that have been made to develop an effective process, the economic aspect of BC production is still a limiting factor for broadening applications, and new “breaking point” solutions are highly anticipated. In this study, the possibility of using sucrose, lactose, and starch as alternative carbon sources converted to simple sugars directly in the culture medium by microbial glycohydrolases, β-D-fructofuranosidase, β-galactosidase, and glucoamylase in the process of BC synthesis was analysed. The results showed the high potential of the enzyme-assisted fermentation process that, for most used raw carbons sources, was highly efficient, with a yield higher (i.e., lactose 40% more) or comparable to the cultures maintained on standard Hestrin-Schramm media with glucose as a sole carbon source. The X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscope analyses did not reveal any negative influence of enzyme-assisted cultivation on the BC material properties, such as crystallinity, swelling ratio, and moisture content. Applying specific enzymes for converting inaccessible, raw-form carbon sources to the culture medium of Komagateibacter xylinus opens a simple way to use various oligo- and polysaccharides acquired from many kinds of biomass sources in the BC production process.

Spherical nanoparticle-modified bacterial cellulose drives SH−SY5Y cell differentiation and inhibits bacterial proliferation

Bacterial cellulose (BC) possesses good physical and mechanical properties for tissue engineering, but its negatively charged surface hinders cell adhesion. Here, the surface charge of BC was modulated with 2 −bromoethylamine hydrobromide (2 −BrEA) via a one-step synthesis method performed in alkaline aqueous solutions at room temperature. Positively charged spherical nanoparticles were thus formed in situ on BC. The amination degree of ethylamine-modified BC materials (BC−EAs) reached 2.80 mmol/g; whereas the crystallinity, fiber diameter, and water contact angle were 55.5 − 65.5%, 30 − 45 nm, and 32.5 − 44.9°, respectively. BC−EAs possess good antibacterial effectiveness against Escherichia coli and Staphylococcus aureus. The CCK− 8 and live/dead assays suggest that BC modified with 0.09 g/mL 2 −BrEA (BC−EA3) is biocompatible and possesses a high efficiency for promoting human neuroblastoma SH−SY5Y cell proliferation and differentiation. Its antibacterial ability is beneficial for preventing the formation of biofilms in the extracellular matrix during tissue and organoid formation, while the properties promoting SH−SY5Y cell proliferation and differentiation make BC−EA3 a good candidate for nerve- or other tissue engineering.

The cross-linked bacterial cellulose impregnated with octenidine dihydrochloride-based antiseptic as an antibacterial dressing material for highly-exuding, infected wounds

The highly absorbent, antibacterial dressings with a sustained release of the antimicrobial are considered necessary measures to counteract chronic wound biofilm-based infections. This study aimed to analyze wet and dry bacterial cellulose (BC) materials, modified by chemical cross-linking, and impregnated with an antiseptic based on octenidine dihydrochloride (OCT) in the context of its antibiofilm/antibacterial activity, exudate absorption, and cytotoxicity. The native BC was obtained from cost-effective, ecological-friendly potato juice (leftover from the starch industry). The ability to absorb and retain OCT, exudate absorption capacity, the kinetics of OCT release as well as antibiofilm/antibacterial activity of modified BC materials against biofilm-forming and planktonic bacteria (Staphylococcus aureus and Pseudomonas aeruginosa) were investigated. The performed analyses revealed that modified BC materials, thanks to their layered structure with numerous air spaces, were characterized by sustained exudate absorption and OCT release profile, which allowed them to exhibit high antimicrobial activity for up to 7 days, with a reduction of planktonic and biofilm cells of 84–100% and 69–93%, respectively. The modified BC materials showed also no cytotoxicity against fibroblast cell line L929 in vitro and were characterized by firm adhesion to the curved surfaces. These results indicate that cross-linked BC impregnated with OCT may be a particularly promising dressing material (obtained using sustainable processes), especially in the treatment of biofilm-infected, highly-exuding wounds.

The effects of temperature, pressure, and time on lignin incorporation in bacterial cellulose materials

The effects of temperature, pressure, and time on lignin incorporation in bacterial cellulose materials

Quickly and efficiently remove multiple pesticides in tea infusions by low-cost carbonized bacterial cellulose

Soaking tea leaves make tea consumers exposure to pesticide residues more easily. However, there are few studies on the removal of pesticides in tea infusions. Therefore, a low-cost carbonized bacterial cellulose material was prepared by direct calcination method, and used to remove multiple pesticides in tea infusions quickly and efficiently. CBC-350 has the best removal efficiency for 9 pesticides and then screened the best adsorption conditions. The adsorption isotherm experiment was carried out and indicated that the adsorption process was in consist with the Freundlich model. The thermodynamic parameters are also calculated. Moreover, the adsorption mechanism was discussed, which suggests that π-π interaction and hydrophobic action are the driving force during the adsorption process. Exhilaratingly, the CBC-350 also has excellent adsorption capacity compared to other adsorbents and can be reused at least five times.

Bacterial cellulose spheroids as building blocks for 3D and patterned living materials and for regeneration

Engineered living materials (ELMs) based on bacterial cellulose (BC) offer a promising avenue for cheap-to-produce materials that can be programmed with genetically encoded functionalities. Here we explore how ELMs can be fabricated in a modular fashion from millimetre-scale biofilm spheroids grown from shaking cultures of Komagataeibacter rhaeticus. Here we define a reproducible protocol to produce BC spheroids with the high yield bacterial cellulose producer K. rhaeticus and demonstrate for the first time their potential for their use as building blocks to grow ELMs in 3D shapes. Using genetically engineered K. rhaeticus, we produce functionalized BC spheroids and use these to make and grow patterned BC-based ELMs that signal within a material and can sense and report on chemical inputs. We also investigate the use of BC spheroids as a method to regenerate damaged BC materials and as a way to fuse together smaller material sections of cellulose and synthetic materials into a larger piece. This work improves our understanding of BC spheroid formation and showcases their great potential for fabricating, patterning and repairing ELMs based on the promising biomaterial of bacterial cellulose.

The Mould War: Developing an Armamentarium against Fungal Pathogens Utilising Thymoquinone, Ocimene, and Miramistin within Bacterial Cellulose Matrices.

An increase in antifungal resistance has seen a surge in fungal wound infections in patients who are immunocompromised resulting from chemotherapy, disease, and burns. Human pathogenic fungi are increasingly becoming resistant to a sparse repertoire of existing antifungal drugs, which has given rise to the need to develop novel treatments for potentially lethal infections. Bacterial cellulose (BC) produced by Gluconacetobacter xylinus has been shown to possess many properties that make it innately useful as a next-generation biopolymer to be utilised as a wound dressing. The current study demonstrates the creation of a pharmacologically active wound dressing by loading antifungal agents into a biopolymer hydrogel to produce a novel wound dressing. Amphotericin B is known to be highly hepatotoxic, which reduces its appeal as an antifungal drug, especially in patients who are immunocompromised. This, coupled with an increase in antifungal resistance, has seen a surge in fungal wound infections in patients who are immunodeficient due to chemotherapy, disease, or injury. Antifungal activity was conducted via Clinical & Laboratory Standards Institute (CLSI) M27, M38, M44, and M51 against Candida auris, Candida albicans, Aspergillus fumigatus, and Aspergillus niger. This study showed that thymoquinone has a comparable antifungal activity to amphotericin B with mean zones of inhibition of 21.425 ± 0.925 mm and 22.53 ± 0.969 mm, respectively. However, the mean survival rate of HEp-2 cells when treated with 50 mg/L amphotericin B was 29.25 ± 0.854% compared to 71.25 ± 1.797% when treated with 50 mg/L thymoquinone. Following cytotoxicity assays against HEp-2 cells, thymoquinone showed a 71.25 ± 3.594% cell survival, whereas amphotericin B had a mean cell survival rate of 29.25 ± 1.708%. The purpose of this study was to compare the efficacy of thymoquinone, ocimene, and miramistin against amphotericin B in the application of novel antifungal dressings.

Hybrid Living Capsules Autonomously Produced by Engineered Bacteria.

Bacterial cellulose (BC) has excellent material properties and can be produced sustainably through simple bacterial culture, but BC‐producing bacteria lack the extensive genetic toolkits of model organisms such as Escherichia coli (E. coli). Here, a simple approach is reported for producing highly programmable BC materials through incorporation of engineered E. coli. The acetic acid bacterium Gluconacetobacter hansenii is cocultured with engineered E. coli in droplets of glucose‐rich media to produce robust cellulose capsules, which are then colonized by the E. coli upon transfer to selective lysogeny broth media. It is shown that the encapsulated E. coli can produce engineered protein nanofibers within the cellulose matrix, yielding hybrid capsules capable of sequestering specific biomolecules from the environment and enzymatic catalysis. Furthermore, capsules are produced which can alter their own bulk physical properties through enzyme‐induced biomineralization. This novel system uses a simple fabrication process, based on the autonomous activity of two bacteria, to significantly expand the functionality of BC‐based living materials.