Bacteria Cellulose Research Articles

Nanocellulose-based membranes with pH- and temperature-responsive pore size for selective separation

Smart gating membranes have drawn much attention due to the controllable pore structure. Herein, a smart gating membrane with dual responsiveness was prepared from bacteria cellulose (BC) grafted with pH- and temperature-responsive polymers. By external stimulation, the average pore size of the membrane can be controlled from 33.75 nm to 144.81 nm, and the pure water flux can be regulated from 342 to 2118 L·m−2·h−1 with remarkable variation in the pH range of 1–11 and temperature range of 20–60 °C. The adjustability of pore size is able to achieve the gradient selective separation of particles and polymers with different sizes. In addition, owing to the underwater superoleophobicity and the nanoscale pore structure, the membrane separation efficiencies of emulsified oils are higher than 99 %. Moreover, the controllable pore size endows the membrane with good self-cleaning performance. This nanocellulose-based smart gating membrane has potential applications in the fields of controllable permeation, selective separation, fluid transport, and drug/chemical controlled release systems.

Confinement of the Permittivity Enhancing Fillers in Bacterial Cellulose for Dielectric Elastomer Applications

The electromechanical performances of dielectric elastomers were investigated after the incorporation of the confined permittivity enhancing fillers in bacteria cellulose (BC) into polydimethylsiloxane (PDMS) films. The purpose of this study is to investigate the capability of BC as a confinement matrix for the permittivity enhancing fillers to overcome the low relative permittivity and at the same time to increase the softness of the PDMS films. The metal oxide and silicone oil were confined in BC before being physically mixed with PDMS at different percentages. The results showed that the confined TiO2-BC increased the relative permittivity and at the same time maintained the softness of the PDMS films to some extent. In addition to that, by adding confined silicone oil-BC into the PDMS films, this PDMS based dielectric elastomer (DE) becomes even softer.

Effect of Sucrose Amounts on the Bacterial Cellulose Membrane's Breathability Properties

This study aims to produce a bacteria cellulose (BC) membrane. The critical parameter controlled in this study was the amount of carbon source during the production. The effects of carbon source concentrations on BC membrane properties, such as yield, thickness, and breathability, were evaluated. The BCs' yields and thicknesses were increased with the higher concentration of sucrose utilised during the production process. By weighing and observing the BC membranes, sample BCS10.0 possessed the highest yield and thickness. Nonetheless, the lowest yield and thickness of BC membrane (1.374%, 0.07mm) produced a high mean pore diameter (16.909Å) and increased permeability of water vapour (4242.23g/m2/day).

Development of Fed-Batch Strategy to Produce Bacteria Cellulose

Bacteria Cellulose (BC) is a type of biopolymer widely used in areas such as biomedicine and paper manufacturing industries. The batch fermentation mode of BC is less cost-effective as the yield is low. This study aims to determine the best fed-batch cultivation strategy to produce BC of high yield and quality. First, batch fermentation mode was carried out to determine the glucose consumption profile of Gluconacetobacter xylinus using Yeast Extract Glucose Chloramphenicol Medium (YGC). By using the information, the fed-batch strategies with feeding frequencies of 1 time and 3 times per 14-day total fermentation period and varied feed composition (YGC medium and pure glucose solution) were set up. The yield, water holding capacity, morphology, and strength of BC were monitored. It is found that BC produced from fed-batch modes has a higher yield (3.75 g/L for low feed frequency and 4.79 g/L for high feed frequency) compared to batch mode (2.24 g/L). The BC produced with pure glucose solution has the highest water holding capacity (87.34 g water/g sample) among the different modes. The FE-SEM micrographs showed that BC produced in the high feeding frequency with YGC medium fed-batch mode has the highest microfibril density and, thus, the best mechanical strength from this mode. To conclude, the fed-batch mode with higher feeding frequency(3 days intervals for a total of 14 days) using YGC medium has the best BC yield and quality.

Fe-single-atom catalyst nanocages linked by bacterial cellulose-derived carbon nanofiber aerogel for Li-S batteries

Li-S battery (LSB) is promising for achieving high capacity. Still, its development is hindered by the complex redox process with sluggish kinetics and particularly the resulting lithium polysulfides (LiPS) shuttle effects. Single-atom catalysts (SACs), with their maximized atom utilization, could effectively chemisorb soluble LiPSs and expedite the sulfide conversion reaction kinetics. Here we report incorporating Fe single metal atom catalyst (Fe-SAC) in the sulfur cathode design and its electrocatalytic effects. Fe-doped ZIF-8 nanocages were introduced into a cheap biomass bacteria cellulose. A pyrolysis process converted them into an aerogel structure with Fe-SAC-functionalized N-doped carbon nanocages linked by a carbon nanofiber network (FeSA-NC@CBC), which was applied as a scaffold to fabricate freestanding and binder-free sulfur cathodes. We conducted electrochemical measurements to reveal Fe-SAC functions including lowering energy barriers for S8 reduction to liquid-phase LiPSs and further to solid-phase Li2S2/Li2S and accelerating Li2S2/Li2S nucleation and deposition, as corroborated by our theoretical calculation results. Benefiting from the synergistic effects of highly active Fe-SAC and three-dimensional conductive network, the sulfide reaction kinetics is improved, which can diminish LiPS shuttle effects and therefore improve LBS rate performance and cycling stability. Accordingly, the fabricated FeSA-NC@CBC composite cathode delivers an excellent rate capability at 2C with a reversible capacity of 840 mAh/g and a long-term cyclic stability of 800 mAh/g at 1C after 500 cycles.

Metal/bacteria cellulose nanofiber bilayer membranes for high-performance hydrovoltaic electric power generation

Hydrovoltaic devices that produce electricity from water represent a promising solution for green energy harvesting. Hydrovoltaic power generators based on various emerging nanostructured materials have shown great potential in water-enabled electricity generation. However, the development of high-performance and practical hydrovoltaic devices remains limited because of low electric power generation, high cost of precursor materials, and complicated fabrication processes. In this study, we developed a novel metal-coated bacteria cellulose nanofiber bilayer membrane (MBCBM) for high-performance hydrovoltaic power-generation devices. The top side of the MBCBM has metal-bacteria cellulose (BC) nanofibers that serve as a conducting electrode for fast charge carrier collection, whereas the bottom side has BC nanofibers that serve as hydrovoltaic materials for high efficient energy generation. A Schottky barrier was incorporated into the hydrovoltaic device, which enhanced the electric power output. Experiments revealed that the optimized single-MBCBM based hydrovoltaic device generated a maximum voltage of 0.935 V, current of 7.51 mA, and power output of 6.07 mW with a 50 μl electrolyte solution. The hybrid membrane and device design concept is expected to effectively utilize practical sustainable and clean energy sources for Internet of Things (IoT) devices and self-powered wearable devices in next-generation electronics.

Utilization of the sugar fraction from Arabica coffee pulp as a carbon source for bacteria producing cellulose and cytotoxicity with human keratinocyte

Coffee pulp (CP), a by-product of coffee production, is an underutilized resource with significant potential value. CP contains monosaccharides that can serve as an ideal carbon source for bacterial cultivation, enabling the production of value-added components such as medical-grade cellulose. Herein, we extracted the sugar fraction from Arabica CP and used it as a supplement in a growing media of a bacteria cellulose (BC), Komagataeibacter nataicola. The BC was then characterized and tested for cytotoxicity. The CP sugar fraction yielded approximately 7% (w/w) and contained glucose at 4.52 mg/g extract and fructose at 7.34 mg/g extract. Supplementing the sugar fraction at different concentrations (0.1, 0.3, 0.5, 0.7, and 1 g/10 mL) in sterilized glucose yeast extract broth, the highest yield of cellulose (0.0020 g) occurred at 0.3 g/10 mL. It possessed similar physicochemical attributes to the BC using glucose, with some notable improvements in fine structure and arrangement of the functional groups. In cytotoxicity assessments on HaCaT keratinocyte cells, bacterial cellulose concentrations of 2–1000 µg/mL exhibited viability of ≥ 80%. However, higher concentrations were toxic. This research innovatively uses coffee pulp for bacterial cellulose, aligning with the principles of a bio-circular economy that focuses on sustainable biomass utilization.

The Gram-positive bacterium Romboutsia ilealis harbors a polysaccharide synthase that can produce (1,3;1,4)-β-d-glucans

(1,3;1,4)-β-d-Glucans are widely distributed in the cell walls of grasses (family Poaceae) and closely related families, as well as some other vascular plants. Additionally, they have been found in other organisms, including fungi, lichens, brown algae, charophycean green algae, and the bacterium Sinorhizobium meliloti. Only three members of the Cellulose Synthase-Like (CSL) genes in the families CSLF, CSLH, and CSLJ are implicated in (1,3;1,4)-β-d-glucan biosynthesis in grasses. Little is known about the enzymes responsible for synthesizing (1,3;1,4)-β-d-glucans outside the grasses. In the present study, we report the presence of (1,3;1,4)-β-d-glucans in the exopolysaccharides of the Gram-positive bacterium Romboutsia ilealis CRIBT. We also report that RiGT2 is the candidate gene of R. ilealis that encodes (1,3;1,4)-β-d-glucan synthase. RiGT2 has conserved glycosyltransferase family 2 (GT2) motifs, including D, D, D, QXXRW, and a C-terminal PilZ domain that resembles the C-terminal domain of bacteria cellulose synthase, BcsA. Using a direct gain-of-function approach, we insert RiGT2 into Saccharomyces cerevisiae, and (1,3;1,4)-β-d-glucans are produced with structures similar to those of the (1,3;1,4)-β-d-glucans of the lichen Cetraria islandica. Phylogenetic analysis reveals that putative (1,3;1,4)-β-d-glucan synthase candidate genes in several other bacterial species support the finding of (1,3;1,4)-β-d-glucans in these species.

Bacterial cellulose: An eco-friendly low cost biomaterial for dye removal

Bacteria cellulose (BC) is a non-toxic, environmentally friendly, and biodegradable material. Additionally, it is a cheap, easily accessible, and renewable resource. It possesses exceptional properties and is widely used in a variety of industries, including textiles, paper manufacturing, food, pharmaceutical, and waste treatment. The purpose of this study was to assess the capacity for bioadsorption of pure BC in its wet and dry forms . After 210 minutes of incubation at 37°C, 120 rpm, wet and dry BC exhibit the maximum decolorization of Crystal violet (100 mg/L) at 62.72% and 71.32%, and Congo red (100 mg/L) at 44.28% and 35.23%, respectively. Additionally, the characterization and kinetic model of BC were investigated in parallel. In summary, the findings of this work imply that the application of BC in bioadsorption of dyes may be a potential and successful method for solving the concerns of environmental pollution in a way that is low-cost, simple, and environmentally friendly.

Accelerating the Li-ion transmission of free-standing thick electrodes by using CMC-Li as ion-conducting binder

The growing demand for high energy density lithium-ion batteries (LIBs) has made the development of thick electrodes crucial. However, thick electrodes generally show poor rate capability due to the slow ionic transmission, which restricts their application. Herein, this work employed bacteria cellulose (BC) to fabricate free-standing thick LiMn2O4 (LMO) electrodes via vacuum filtration method combined with freeze-drying. Bacteria cellulose endowed thick electrodes with excellent flexibility and good mechanical strength. Simultaneously, Li+-conducting binder, that is carboxymethyl cellulose lithium (CMC-Li), was added to provide thick electrodes with promoted Li+ transmission and improved dynamic performance. The properties of CMC-Li were demonstrated in detail. Then, the structure and electrochemical performance of prepared free-standing thick electrodes were characterized systematically. More importantly, the mechanism of enhanced dynamic performance by CMC-Li was clarified clearly. This work paves a new way to prepare free-standing thick electrodes with high energy density and superior rate capability.

Novel Probiotic/Bacterial Cellulose Biocatalyst for the Development of Functional Dairy Beverage.

The development of innovative functional products with potential health benefits, under the concept of bio-economy, is flourishing. This study undertook an evaluation of non-dairy lactobacilli Lactiplantibacillus pentosus B329 and Lactiplantibacillus plantarum 820 as “ready to use” starter cultures. Lactic acid bacteria (LAB) cultures were evaluated for their fermentation efficiency, before and after freeze-drying, using cheese whey (CW) as a fermentation substrate and subsequent immobilization on bacteria cellulose (BC) to produce a novel biocatalyst. The biocatalyst was applied in functional sour milk production and compared with free cells via the assessment of physicochemical and microbiological properties and sensory evaluation. Evidently, LAB strains exhibited high fermentative activity before and after freeze-drying. Results of a 5-month storage stability test showed that viability was 19% enhanced by immobilization on BC, supporting the concept of “ready to use” cultures for the production of fermented beverages. Likewise, sour milk produced by the BC biocatalyst presented higher organoleptic scores, compared to the free cells case, whereas immobilization on BC enhanced probiotic viability during post-fermentation storage (4 °C, 28 days). The obtained high viability (>107 log cfu/g) demonstrated the efficacy of the proposed bioprocess for the production of functional/probiotic-rich beverages. Ultimately, this work presents a consolidated scheme that includes the advantages and the cooperative effect of probiotic LAB strains combined with a functional biopolymer (BC) towards the formulation of novel functional products that coincide with the pillars of food systems sustainability.

Energy absorption of densified veneer-aramid hybrid composites subjected to ballistic impact

Densified wood technology improves the wood properties such as strength, surface hardness, dimensional stability, and durability. However, the utilization of laminated veneer as densified wood which is used as an armor material, and its ability to absorb ballistic energy has not been researched. The strengthening of the Teak Platinum veneer, which was densified with a hot press, used pre-treatment methods such as partial delignification and self-assembly of bacteria cellulose using Acetobacter xylinum. This research used hybrid and non-hybrid panels. The hybrid panel used epoxy adhesive to combine the laminated aramid fabric and 2 types of densified veneer laminated. Two types of densified veneers consist of the densified veneer with and without stabilizing resin. A ballistic test was carried out on each sample at a distance of 5 m using 9 mm Luger ammunition according to NIJ 0108.01. The ballistic energy absorption was analyzed based on the difference between the initial velocity and the residual velocity of the projectile. The initial velocity and the residual velocity were measured by the chronograph. This result showed that the performance of the hybrid panels was lower than the non-hybrid panels at the same thickness. However, the hybrid panels using aramid and veneer ratio of 2:1 (by volume) and the configuring of fully aramid fabric on the inside was the best combination with a ballistic energy absorption of 78.64% at 354.70 J.

Wood Veneer Reinforced with Bacterial Cellulose: Tensile Strength and Dynamic Mechanical Analysis

Cellulose from plants is a natural polymer that is very abundant, cheap and easy to process. In addition, there is bacterial cellulose produced from bacterial fermentation of acetic acid with limited production but has high purity, crystallinity, and tensile strength. In this research, the process of wood-veneer delignification was carried out to self-assembly bacterial cellulose into wood cavities on bacterial culture media. Wood veneer reinforced bacteria cellulose was given heat pressure to increase the density and it was expected to form hydrogen bonds between their cellulose molecular chains. This study observed the duration of fermentation in bacterial media culture on the tensile strength of hybrid veneers, microscopic observations, the effect of water on set-recovery, and the characteristics of solid veneers on cyclic loading and temperature using dynamic mechanical analysis (DMA) testing. The microscopic observations prove that Acetobacter xylinum can penetrate the veneer and assemble bacterial cellulose in the cavity. A higher tensile strength ratio of 81.38% was observed in densified veneers with a five-day fermentation period with a modulus of elasticity 156.63% higher than natural veneers. The minimum set-recovery after boiling the hybrid veneer was 29.32%. DMA showed that by reinforcing wood veneer with bacterial cellulose and compacting, it increased cyclic energy storage ability, reduced energy loss, and increased stability under increasing temperatures. Strengthening wood with bacterial cellulose in this method opens new potential for developing more environmentally friendly forest products in the future.

Bacteria Cellulose and Resin Stabilization in Densified Veneer

Cellulose produced by fermentation of acetic acid bacteria has high tensile strength. Meanwhile, cellulose derived from wood, which is abundant in nature, has a limit in strength. In this work, delignified wood veneer was immersed in Acetobacter xylinum culture medium to self-assemble bacterial cellulose into wood pores. Then the process was continued with a heating press. It makes the material denser and causes hydrogen bonds to form between the cellulose fibers. This study observed the densified hybrid veneer for the period of bacterial fermentation and impregnation of resin stabilization in tensile strength and dynamic mechanical analysis (DMA). The densified hybrid veneer of bacterial cellulose with resin impregnation had the maximum tensile strength after 7 days of fermentation. The DMA test showed that a densified hybrid veneer of bacterial cellulose stabilized with resin has a good ability to store cyclic energy and a damping factor that increases with temperature. HIGHLIGHTS A heating press compacted densified wood veneer with bacterial cellulose (BC), forming in hybrid veneers Hybrid veneer improves the mechanical strength Densified veneer-BC-stabilized by fermentation for 7 days had the maximum tensile strength The densified veneer that is reinforced with BC and stabilized with resin has a good ability to store cyclic energy GRAPHICAL ABSTRACT

Calculate The Conductivity of Some Composites of Cellulose Bacteria Mixed with Polypyrol

The manufacture of composites that have good electrical properties is to use a conductive polymer matrix. A conductive polymer is a polymer compound that has a stable bond that allows the polymer to act as a good conductor of electricity. This study aims to determine the highest conductivity value of composite materials that have been coated with polypyrrole, namely bacterial cellulose with polypyrrole (bio composite 1), tempo bacteria cellulose with polypyrrole (bio composite 2), and Gambier bacteria cellulose with polypyrrole (bio composite 3). In this study, there were four samples consisting of nata de coco (cellulosic bacteria), 2, 2, 6, 6-tetramethylpiperidine 1-oxyl (TEMPO), Gambier extract, and polypyrrole. Measurement of resistance value using the two point probe method. The results of this study obtained that the resistance and conductivity values of bio composite 1, bio composite 2, and bio composite 3 were 29.742 k? and 1.17810-3 S/cm, 20.338 k? and 1.69210-3 S/cm, 34,572 k? and 0.980710-3 S/cm. The measurement results show that the highest conductivity value is bio composite 2.

Bacterial cellulose nanofiber triboelectric nanogenerator based on dielectric particles hybridized system

Triboelectric nanogenerators (TENGs) is an emerging method to convert mechanical energy into electricity, however, the complicated methods to improve the output performance greatly limited their potential applications. In this work, a simple and effective method was used to improve bacteria cellulose (BC) based TENG. The BC composite film friction material with a hybridized system of silver nanowires and BaTiO3 (BTO) particles was prepared by filtration method. One-dimensional silver nanowires particles and tetragonal phase BTO particles played an important role in improving the dielectric constant and surface roughness of the material respectively. With the combination of the enhancement of dielectric constant and the improvement of surface structure of the BC composite film, the short-circuit current of BC/AgNWs/BTO-based TENG was 7.1 μA, the open-circuit voltage was 87 V, and the transfer charge was 35 nC at a frequency of 3 Hz. In addition, when an external resistor was connected, the peak power density can reach 75 μW/cm2, and the overall TENG had good output stability. Moreover, the BC/AgNWs/BTO-based TENG can collect mechanical energy through human–machine movement when combined with a portable electronic device. This work demonstrates the great potential of cellulose-based materials in TENG and other electronic applications.

The Effect of Bacterial Cellulose on The Thermo Hydro-Mechanical Treatment of Wood Veneer

Wood is the largest source of cellulose in the nature however it has a low strength. In other hand, bacteria cellulose as a pure cellulose has a higher tensile strength than wood. Wood reinforced with bacterial cellulose was produced by self-assembly approach with veneer soak into the fermentation medium. The product of this research is hybrid veneer processed thermos-hydro-mechanical treatment. It has been used to give a change in its mechanical properties. This research analyzed mechanical tensile test, Fourier transform infrared spectroscopy, and field emission scanning electron microscopy. The result showed that bacteria cellulose had impact to increase tensile strength of veneer and improve the molecular strength between cellulose fibers. Hydrogen bonds were formed between veneer fibers and bacterial cellulose then those bonds stick together and resulted in strong adhesion.

Highly sensitive, flexible, green synthesized graphene/biomass aerogels for pressure sensing application

With the advent of the Internet-of-Things (IoT) age, flexible sensors are highly desired in various intelligent systems. However, most of them are based on petrochemical materials and the inevitable use of toxic chemicals during their manufacturing, which may lead to potential damage to human health. Herein, we report a green and facile strategy to fabricate pressure sensors based on bacteria cellulose and caffeic acid-reduced graphene oxide (rGO) composite aerogel. Benefiting from the three-dimensional (3D) hierarchical porous structure (a porosity of ~98.9%), the pressure aerogel sensor exhibits integrated performance of high sensitivity (13.89 kPa−1), ultralow limit of detection (47.2 Pa), and fast response (120 ms), thus clearly detecting subtle strain and monitoring human physical motions. Remarkably, the aerogel possesses excellent reproducibility in 1000 cycles of pressure loading-unloading. Hence, the strategy of using natural resources to fabricate flexible functional materials is highly possible to apply in flexible electronics field.

Macroscopic Poly Schiff Base-Coated Bacteria Cellulose with High Adsorption Performance.

Here, a nanofiber-exfoliated bacteria cellulose aerogel with improved water affinity and high mass transfer was synthesized. Consequently, poly Schiff base can be uniformly coated within the body of bacteria cellulose aerogel without the traditional dispersion treatment. The composite aerogel has adequate mechanical and thermal stability and high mass transfer efficiency. Such an aerogel can serve as a superior adsorbent for flow through adsorption of pollution. Typically, the adsorption capacity towards Cr(VI), Cu(II), Re(VII), Conga red, and Orange G reaches as high as 321.5, 256.4, 153.8, 333.3, and 370.3 mg g−1, respectively. Moreover, the adsorption by this composite aerogel is very fast, such that, for example, at just 2 s, the adsorption is almost finished with Cr(VI) adsorption. Moreover, the composite aerogel exhibits a good adsorption-desorption capability. This research will hopefully shed light on the preparation of bacteria cellulose-derived macroscopic materials powerful in not only environmental areas, but also other related applications.

The effect of sodium hydroxide concentration on yield and properties of Bacterial Cellulose membranes

Bacteria cellulose (BC) derived from Acetobacter xylinum strain possess several advantages such as elevated water holding capacity, high porosity and excellent mechanical strength. BC is useful to replace vegetal plant and applied into various industrial field such as papermaking, packaging and textile. In this study, BC membranes were produced from coconut water based consists of 8.0% sugar, 0.5% ammonium sulphate and 1.0% acetic acid at pH 4.5, followed with the addition of 10.0% inoculum before subjected to static incubation for 7 days. This study evaluated the changes of BC membrane properties using different concentration of sodium hydroxide (NaOH) under room temperature within 24 hours. The morphological, physical, chemical structure and water vapour permeability (WVP) of BC were analysed using FESEM, XRD, FTIR and WVP analysis, respectively. Results show that BC is mainly consist of cellulose I± with high crystallinity and smaller crystallite sizes. The differences in NaOH concentrations varied the fibrils diameter of cellulose, in accordance to FESEM images. The use of higher concentration of NaOH (≥ 2.0%) gave a smooth cellulose structure with less porosity, thus reducing the WVP properties of BC.