Pure Bacterial Cellulose Research Articles

The Biosynthesis of Bacterial Cellulose Composites Accompanied by Spray Feeding of Biomasses.

Bacterial cellulose (BC) is a broadly utilized natural nanofiber produced by microbial fermentation, but its high-cost and low-yield production and limited function still hinder its application. Here, we used the spraying-assisted biosynthesis method to introduce biomass nanofibers along with the nutrient media to the fermenting BC. Biomass nanofibers could be cellulose, chitosan, and others. They entangled with BC nanofibers via intermolecular interactions, including hydrogen binding and electrostatic adsorption, to form uniform BC composites. The BC composites achieved an enhanced yield of ~140 wt% compared with pure BC and displayed similar excellent mechanical properties (Young's moduli = 0.9-1.4 MPa for wet films and =~6500 MPa for dried films). BC composites also had similar high crystallinity and thermal stability to pure BC. The functional groups of biomasses endowed BC composite additional functions such as antibacterial and dye-adsorption capabilities. Moreover, a high yield and functionalization could be realized simultaneously by feeding functional cellulose nanofibers. This method provides a facile way to produce BC composites with low cost, high yield, and multiple functions.

Supercritical carbon dioxide–activated copper/bacterial cellulose aerogels for the capture of hydrophobic organic liquids

In this study, bacterial cellulose was derived from coconut water via fermentative production of nata de coco, a common food in Southeast Asia. Bacterial cellulose offers distinct advantages over plant cellulose resources, including three-dimensional structure, high porosity, high cellulose purity, and the absence of required polluting treatments, making it an ideal candidate for the facile preparation of various functional aerogel materials. Surface modification of nata de coco-derived cellulose fibers was obtained by incorporating Cu species (approximately 15 wt%) through an aqueous reaction of Cu(CH3COO)2 with N2H4 at room temperature. The Cu-coated bacterial cellulose aerogels were fabricated via supercritical carbon dioxide drying to maintain the natural three-dimensional matrix and subsequently characterized by various techniques confirming high porosity and crystallinity and successful Cu coating onto the cellulose fiber surface. The Cu-containing aerogel showed a significantly improved adsorption uptake for n-hexane (12.6 g g−1) in comparison with pure bacterial cellulose–based aerogel (3.2 g g−1). Furthermore, notable adsorption performances of 13.6–19.9 g g−1 were found for cyclohexane, ethyl acetate, and soybean oil, indicating the high efficiency of the supercritical carbon dioxide–activated bacterial cellulose aerogel containing Cu species in the adsorption of water-insoluble liquids. Notably, applying supercritical carbon dioxide drying afforded the stable aerogel structure for reusing over several cycles with almost unchanged trapping capacity.

Development of silanized bacterial cellulose aerogels for the incorporation of natural oils with healing properties: Copaiba (Copaifera officinalis), bourbon geranium (Pelargonium X ssp.) essential oils and buriti (Mauritia flexuosa) vegetable oil

Bacterial cellulose (BC) represents a promising biomaterial, due to its unique and versatile properties. We report, herein, on purposely-designed structural modifications of BC that enhance its application as a wound dressing material. Chemical modification of the functional groups of BC was performed initially to introduce a hydrophobic/oleophilic character to its surface. Specifically, silanization was carried out in an aqueous medium using methyltrimethoxisilane (MTMS) as the silanizing agent, and aerogels were subsequently prepared by freeze-drying. The BC-MTMS aerogel obtained displayed a highly porous (99 %) and lightweight structure with an oil absorption capacity of up to 52 times its dry weight. The XRD pattern indicated that the characteristic crystallographic planes of the native BC were maintained after the silanization process. Thermal analysis showed that the thermal stability of the BC-MTMS aerogel increased, as compared to the pure BC aerogel (pBC). Moreover, the BC-MTMS aerogel was not cytotoxic to fibroblasts and keratinocytes. In the second step of the study, the incorporation of natural oils into the aerogel's matrix was found to endow antimicrobial and/or healing properties to BC-MTMS. Bourbon geranium (Pelargonium X ssp.) essential oil (GEO) was the only oil that exhibited antimicrobial activity against the tested microorganisms, whereas buriti (Mauritia flexuosa) vegetable oil (BVO) was non-cytotoxic to the cells. This study demonstrates that the characteristics of the BC structure can be modified, while preserving its intrinsic features, offering new possibilities for the development of BC-derived materials for specific applications in the biomedical field.

Covalently grafting polycation to bacterial cellulose for antibacterial and anti-cell adhesive wound dressings

Hydrogel-based wound dressings are becoming increasingly important for wound healing. Bacterial cellulose (BC) has been commonly used as wound dressings due to its good in vitro and in vivo biocompatibility. However, pure BC does not possess antibacterial properties. In this regard, polycation gel was grafted onto the BC using a surface-initiated activator regenerated by electron transfer atom transfer radical polymerization (SI-ARGET ATRP) with subsequent quaternization for antibacterial wound dressing. Dimethylethyl methacrylate (DMAEMA) was successfully polymerized on the BC surface which was confirmed by Fourier transform infrared spectroscopy and elemental analysis. The morphology structure, specific surface area, pore size, and mechanical properties were also characterized. The quaternized PDMAEMA grafted on the BC endowed it with excellent antibacterial activity against E. coli (Gram-negative) and S. aureus (Gram-positive) with a killing rate of 89.2 % and 93.4 %, respectively. The number of cells was significantly reduced on QPD/BC hydrogel, demonstrating its good anti-adhesion ability. In vitro cellular evaluation revealed that the antibacterial wound dressing exhibited good biocompatibility. Overall, this study provides a feasible method to develop antibacterial and anti-cell adhesive hydrogel, which has a promising potential for wound healing.

Characterisation of Bio composites for Bio-Manufacturing: Jute-reinforced Bacterial Cellulose for Construction

This research investigates the biological, mechanical and thermal characterisation of the jute-reinforced bacterial cellulose biocomposites to forecast their potential and performance in bio-manufacturing for architectural construction. The experimental trial-and-error-based methodology involves seven stages: Material formulation, manufacturing of biocomposite samples, mechanical testing, scanning electron microscopy analysis, thermogravimetric analysis, and biodegradation assessment. The results indicated that the use of biobased construction materials has a potential to reduce carbon footprint, while the addition of jute fibres resulted in enhanced mechanical properties such as higher elasticity and desirable stiffness compared to pure bacterial cellulose. Moreover, slight distinctions in thermal property analysis and biodegradation assessments across the specimens are observed. The findings contribute valuable data for material selection, design optimization, and structural considerations in the integration of these biopolymers into construction practices. Overall, this research aligns with the broader objective of advancing ecological construction starting from the material formulations, thus addressing the scalability of these materials, considering their potential for large-scale adoption in the construction industry.

Synthesis of Extract-Bacterial Cellulose Composite Using Ageratum conyzoides L. and Chromolaena odorata L., Its Antibacterial Activities, and Biodegradability Properties.

Bacterial cellulose is a natural polymer produced by fermentation of coconut water using Acetobacter xylinum bacteria. This study aimed to synthesize a novel composite of bacterial cellulose impregnated with plant extracts that had an antibacterial activity that have the potential to be used as a food packaging material to maintain food quality. Pure bacterial cellulose (pure BC) was impregnated using Ageratum conyzoides L. leaf extract (AC-BC) and Chromolaena odorata L. leaf extract (CO-BC), which contain secondary metabolites with potential as antibacterial. The study began with the synthesis of pure BC, AC-BC, and CO-BC composites then characterized by SEM-EDX and FTIR, continued with antibacterial activity tests against S. aureus, S. typhimurium, E. coli, and their biodegradability tests. The results of SEM and FTIR characterization showed the success of the impregnation process for antibacterial compounds. The results of the antibacterial activity of AC-BC disc diffusion against S. typhimurium and E. coli showed good antibacterial activity of 9.82 mm and 8.41 mm, respectively. The similar result showed with the antibacterial activity of CO-BC disc diffusion against S. typhimurium and E. coli that showed good activity of 9.73 mm and 6.82 mm, respectively. On the other hand, the biodegradability test showed that the impregnation of bacterial cellulose slowed down the degradation process in the soil. This study confirmed the potential application of bacterial cellulose-plant extracts as an active and biodegradable food packaging.

Preparation and characterization of quaternary bacterial cellulose composites for antimicrobial oil‐absorbing materials

AbstractThe treatment of various types of oily wastewater is paramount for environmental protection. Bacterial cellulose (BC) stands out as a highly promising material for oil/water separation, owing to its exceptional mechanical properties and three‐dimensional porous structures. However, excessive hydroxyl groups on BC make it highly hydrophilic, reducing oil absorption and promoting bacterial growth, affecting its stability. To address these challenges, we developed a straightforward in situ polymerization method for the preparation of BC‐DMC composites. The innovation lies in the concurrent enhancement of BC's hydrophobicity and antimicrobial properties only through the addition of 2‐(Methacryloyloxy)ethyltrimethylammonium chloride (DMC), considerably simplifying the synthesis of materials possessing oil‐absorbing and antimicrobial properties. Morphological and structural characterization results confirmed the successful combination of DMC onto BC while maintaining its porous structure. After process parameter optimization, the BC‐DMC composites exhibited a remarkable increase in contact angle (117.7° compared with pure BC's 19.5°). It also demonstrated excellent oil absorption performance, with maximum capacities exceeding 30 g/g for different oils, maintaining values above 20 g/g even after eight cycles. In addition, the BC‐DMC composites exhibited strong antibacterial activity, with rates of 82.4% against Escherichia coli and 97.5% against Staphylococcus aureus. The antibacterial mechanism of the BC‐DMC composites was also discussed. Our novel BC‐DMC composites provides excellent oil absorption and antibacterial properties, making it highly applicable in the field of oily wastewater treatment and serving as a valuable reference for other researchers.

Optimising the Production Process of Bacterial Nanocellulose: Impact on Growth and Bioactive Compounds.

Research into bacterial cellulose production has been growing rapidly in recent years, as it has a potential use in various applications, such as in the medical and food industries. Previous studies have focused on optimising the production process through various methods, such as using different carbon sources and manipulating environmental conditions. However, further research is still needed to optimise the production process and understand the underlying mechanisms of bacterial cellulose synthesis. We used Plackett-Burman and Box-Behnken experimental designs to analyse the effect of different factors on bacterial cellulose production. The fermentation kinetics of the optimised medium was analysed, and the produced cellulose was characterised. This approach was used because it allows the identification of significant factors influencing bacterial cellulose growth, the optimisation of the culture medium and the characterisation of the produced cellulose. The results showed that higher sucrose concentrations, higher kombucha volume fractions and a smaller size of the symbiotic culture of bacteria and yeast were the most important factors for the improvement of bacterial cellulose production, while the other factors had no relevant influence. The optimised medium showed an increase in the concentrations of total phenolic compounds and total flavonoids as well as significant antioxidant activity. The produced pure bacterial cellulose had a high water absorption capacity as well as high crystallinity and thermal stability. The study makes an important scientific contribution by optimising the culture medium to produce bacterial cellulose more productively and efficiently. The optimised medium can be used for the production of a kombucha-like beverage with a high content of bioactive compounds and for the production of bacterial cellulose with high crystallinity and thermal stability. Additionally, the study highlights the potential of bacterial cellulose as a highly water-absorbent material with applications in areas such as packaging and biomedical engineering.

Composite of bacterial cellulose and gelatin: A versatile biocompatible scaffold for tissue engineering

Synthesis of 0.4 ± 0.03 g/L per day of pure and porous bacterial cellulose (BC) scaffolds (scaffBC) and BC scaffolds modified with gelatin (scaffBC/Gel) was carried out using the Medusomyces gisevii Sa-28 bacterial strain. FT-IR spectroscopy and X-ray diffraction analysis showed that the scaffolds largely consist of crystalline cellulose I (Iα, Iß). Heating of BC with gelatin to 60 °C with subsequent lyophilization led to its modification by adsorption and binding of low-molecular fractions of gelatin and the formation of small pores between the fibers, which increased the biocompatibility and solubility of BC. The solubility of scaffBC and scaffBC/Gel was 20.8 % and 44.4 %, respectively, which enhances degradation in vivo. Light microscopy, scanning electron microscopy, and microcomputed tomography showed a uniform distribution of pores with a diameter of 100–500 μm. The chicken chorioallantoic membrane (CAM) model and subcutaneous implantation in rats confirmed low immunogenicity and intense formation of collagen fibers in both scaffolds and active germination of new blood vessels in scaffBC and scaffBC/Gel. The proliferative cellular activity of fibroblasts confirmed the safety of scaffolds. Taken together, the results obtained show that scaffBC/Gel can be used for the engineering of hard and soft tissues, which opens opportunities for further research.

Green Synthesized Magnesium Oxide Nanoparticles Reinforce Osteogenesis Properties of Bacterial Cellulose Scaffolds for Bone Tissue Engineering Applications: An In Vitro Assessment.

The use of biocompatible scaffolds with appropriate characteristics to treat large bone defects has attracted significant attention. The main objective of the current study is to fabricate a 3D nanocomposite structure that contains green synthesized magnesium oxide nanoparticles (MgONPs) and bacterial cellulose (BC) nanofibres, as a bioscaffold for bone regeneration. In this experimental study, Camellia sinensis extract was used as the green method to synthesize MgONPs. The synthesized hydrogels were evaluated for their porosity, morphology, degradation rate, mechanical features, cell attachment, and cytocompatibility. Osteogenic differentiation was assessed by alkaline phosphatase (ALP) activity, real-time reverse transcription-polymerase chain reaction (RT-PCR), and alizarin red staining. MgONPs significantly increased both mechanical strength (P=0.009) and porosity (P=0.01) of the BC hydrogels. Human MG-63 osteoblast proliferation significantly increased in the MgONP-BC group compared to the pure BC group (P=0.003). Expression rates of both the ALP (P=0.001) and osteocalcin (OCN) genes were significantly enhanced in cells seeded on the MgONP-incorporated BC. MG-63 cells had significantly greater calcium deposition and ALP activity (P=0.002) on the MgONP-BC scaffold compared to the BC at day 21. The MgONP-BC scaffold can promote the osteogenic activity of osteoblast-like cells, which indicates its therapeutic potential for bone tissue regeneration.

ANTIMICROBIAL ACTIVITY OF BACTERIAL CELLULOSE MODIFIED WITH PLANT EXTRACTS

Bacterial cellulose (BC) is utilized in numerous industries, including the cosmetic, biomedical, and packaging industries. Nonetheless, BC lacks antibacterial activity and must be combined with antimicrobial agents, including plant extracts. This review aims to give information on the antibacterial activity of BC that has been modified by the addition of plant extracts. The method used in this study is article review. Articles were selected from Q1-Q3 category international journals published within the recent decade. Based on the results, extracts of rhizomes, ethanol extracts of gwarri stems and leaves, oregano leaves, rosemary leaves, lovage leaves, parsley leaves, green tea leaves, rosella petals, and red and pink variants of hibiscus flowers, bitter melon seeds, gletang leaves, arabica coffee, and andaliman fruit, temu Kunci dimethyl sulfoxide extract, mulberry leaf NaOH extract, pomegranate skin water extract, and rosemary leaves have been used to modify BC. Antimicrobial activity showed the most significant increase in BC-modified ethanol extract of rosella petals at a concentration of 500 ppm with an OD600 of 0% against Pseudomonas aeruginosa. FTIR and SEM investigations of pure BC and BC modified with plant extracts revealed variations in functional group content and three-dimensional fibrillar network structure.

An Eco-Friendly Adsorbent Based on Bacterial Cellulose and Vermiculite Composite for Efficient Removal of Methylene Blue and Sulfanilamide.

In this work, a novel composite of bacterial cellulose (BC) and expanded vermiculite (EVMT) composite was used to adsorb dyes and antibiotics. The pure BC and BC/EVMT composite were characterized using SEM, FTIR, XRD, XPS and TGA. The BC/EVMT composite exhibited a microporous structure, providing abundant adsorption sites for target pollutants. The adsorption performance of the BC/EVMT composite was investigated for the removal of methylene blue (MB) and sulfanilamide (SA) from an aqueous solution. The adsorption capacity of BC/ENVMT for MB increased with increasing pH, while the adsorption capacity for SA decreased with increasing pH. The equilibrium data were analyzed using the Langmuir and Freundlich isotherms. As a result, the adsorption of MB and SA by the BC/EVMT composite was found to follow the Langmuir isotherm well, indicating a monolayer adsorption process on a homogeneous surface. The maximum adsorption capacity of the BC/EVMT composite was found to be 92.16 mg/g for MB and 71.53 mg/g for SA, respectively. The adsorption kinetics of both MB and SA on the BC/EVMT composite showed significant characteristics of a pseudo-second-order model. Considering the low cost and high efficiency of BC/EVMT, it is expected to be a promising adsorbent for the removal of dyes and antibiotics from wastewater. Thus, it can serve as a valuable tool in sewage treatment to improve water quality and reduce environmental pollution.

Preparation and antibacterial property of silver nanoparticles loaded into bacterial cellulose

Composite nanomaterials based on silver nanoparticles (AgNPs) are considered promising antimicrobial agents due to their excellent antimicrobial activity. The aim of this work is to develop bacterial cellulose (BC) composites that act synergistically with AgNPs. BC@AgNPs composites were developed using an ex-situ composite development strategy and evaluated for their structural characteristics and antimicrobial activities. Field emission scanning electron microscopy (FESEM) showed impregnation of AgNPs into the porous BC network. The composite formulation was also confirmed by x-ray diffraction (XRD) analysis, which showed the presence of additional crystalline peaks along with those of the pure BC. Bactericidal tests of BC@AgNPs nanocomposites against common pathogens, including Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus, showed a significant reduction in their growth compared to pure BC. These results suggest that the synthesized BC@AgNPs composites could be promising antibacterial materials for potential applications in a wide range of medical and environmental applications.

GO-Enabled Bacterial Cellulose Membranes by Multistep, In Situ Loading: Effect of Bacterial Strain and Loading Pattern on Nanocomposite Properties.

This paper presents the results of research on the preparation and properties of GO/BC nanocomposite from bacterial cellulose (BC) modified with graphene oxide (GO) using the in situ method. Two bacterial strains were used for the biosynthesis of the BC: Komagataeibacter intermedius LMG 18909 and Komagataeibacter sucrofermentans LMG 18788. A simple biosynthesis method was developed, where GO water dispersion was added to reinforced acetic acid-ethanol (RAE) medium at concentrations of 10 ppm, 25 ppm, and 50 ppm at 24 h and 48 h intervals. As a result, a GO/BC nanocomposite membrane was obtained, characterized by tensile strength greater by 150% as compared with the pure BC (̴ 50 MPa) and lower volume resistivity of ~4 ∙ 109 Ω × cm. Moreover, GO addition increases membrane thickness up to ~10% and affects higher mass production, especially with low GO concentration. All of this may indicate the possibility of using GO/BC membranes in fuel cell applications.

One-step in situ biosynthesis fabrication of double-network hydrogel electrolytes with satisfactory water retention capacity and excellent electrical conductivity for Zn-air batteries

• The BC-PVA composite hydrogel was successfully prepared by a one-step in situ biosynthesis method. • Benefiting from the double-network, the BC-PVA hydrogel had excellent water retention and electrical conductivity capacity. • The sandwich-type ZABs based on BC-PVA exhibited excellent electrochemical performance. In the semi-open environment of flexible Zn-air batteries, water in the electrolyte inevitably evaporates continuously leading to a drastic decrease in ionic conductivity. The development of novel electrolytes with excellent water retention capacity and superior electrochemical performance for long-term stability is the key to improve the life of Zn-Air batteries. In this paper, BC-PVA composite hydrogel was successfully prepared by adding polyvinyl alcohol (PVA) suspension to bacterial cellulose (BC) medium using a one-step in situ biosynthesis method. Benefiting from the double network structure, the hydrogel exhibited excellent performance. The experimental results showed that the BC-PVA-2 composite hydrogel had an excellent water retention rate of 97.90%. Compared with pure BC, the breaking strength and ionic conductivity of BC-PVA-2 containing 2 wt.% PVA were improved by about 42% and 600%, respectively. After assembling the sandwich-type Zn-air batteries (ZABs), the open circuit voltage was 1.32 V, the peak charge current density was 110 mA·cm -2 .

РЕЗУЛЬТАТЫ ЗАЖИВЛЕНИЯ ОЖОГОВЫХ РАН С ПОМОЩЬЮ РАНЕВЫХ ПОКРЫТИЙ НА ОСНОВЕ БАКТЕРИАЛЬНОЙ ЦЕЛЛЮЛОЗЫ В ЭКСПЕРИМЕНТЕ

Purpose of the study: in experimental studies to evaluate the effectiveness of healing and changes in the microbial spectrum of deep burn wounds during their treatment using wound dressings based on bacterial cellulose. Materials and methods. The object of the experimental studies was 60 Wistar rats, which formed a deep skin burn. All animals were divided into 3 groups, of which in group 1 (n=20) burn wounds were treated with pure wet bacterial cellulose (BC) wound dressings, in group 2 (n=20) BC was used with exposure to a 1% chlorhexidine and in group 3 (n=20) traditional treatment was performed with Levomekol ointment. On days 5, 10, 15, 20, 28 in the groups, the area of the wound surfaces, the dynamics of their decrease, and the microbial spectrum were studied. Results and conclusions. We registered that wound dressings based on wet bacterial cellulose, applied in pure form and with exposure to an antiseptic (1% chlorhexidine solution) for 28 days, increase the healing rate of burn wounds by an average of 18% compared to the traditional treatment group. The formed scab over the wound, when BC dries, provides the wound surface with a mechanical protective barrier that prevents injury to emerging dermal cells, microbial contamination and thereby increases the rate of epithelialization in a closed environment.

Optimization of bacterial cellulose production from prickly pear peels and its ex situ impregnation with fruit byproducts for antimicrobial and strawberry packaging applications

Bacterial cellulose (BC) is currently among the most promising natural polymers. However, the production costs and biological inactivity are still challenges. The current study exploited the enzymatically hydrolyzed prickly pear peels (PPP) for BC production, which supported about 2.94 g/L as the sole production medium. The BC production was further optimized through a central composite design, where the maximum BC production was 6.01 g/L at 68 % PPPE at pH 4 after 11 days of incubation at 20 °C. The produced BC was characterized by FT-IR spectroscopy, XRD, and SEM analysis, and the results showed that PPPE is a promising carbon source for pure BC production. The BC membrane was separately loaded with several fruit byproduct extracts to enhance its biological activity for multiple applications. BC loaded with pomegranate peel extract (BC/PPE) revealed significant broad-spectrum antimicrobial activity, followed by BC loaded with pomegranate molasses (BC/PM). The BC/PPE membrane enhanced the shelf-life storage of strawberry fruits by about 5 days, with a reduction in the fruits' weight loss of 15 % compared to the uncovered group. The current study revealed the successful application of PPE for sustainable BC production with its packaging potential for enhancing strawberry shelf-life when loaded with PPE or PM.

Preparation of 3D Printed Polylactic Acid/Bacterial Cellulose Composite Scaffold for Tissue Engineering Applications.

Bacterial cellulose (BC) has become a universal biomaterial owing to its intrinsic properties. BC fibers are composed of microfibers with a diameter of 3-4 nm into fiber bundles with a thickness of 40-60 nm, and interweave with each other to form a well-developed ultra-fine network structure. Polylactic acid (PLA) has good mechanical properties and excellent biocompatibility and biodegradability. Therefore, PLA has been widely applied in tissue engineering. Addressed herein is a novel type of PLA/BC (PLA/BC) composite scaffold prepared by 3D printing (3D), 3D modeling of the required porous membrane material support established in the computer, and decomposition of the model into 5 layer 20 μM sheets. The range of PLA loadings assessed in this work was 1.0 wt.%, 1.5 wt.%, and 2.0 wt.%, and its physicochemical properties and biological properties were characterized and evaluated. Tensile strength of PLA/BC composite scaffolds increased to 66.49 MPa compared to that of a pure BC film (25.61 MPa). Hydrophilicity was tunable with the amount of added PLA. In this paper, the effects of 3D round hole and stripe surface topology on cell growth behavior were characterized. Schwann cells (SCs) adhered to the surface of the 3D composite membrane successfully, and their proliferation rate on the surface of the regular circular pore and stripe structure was better than that of the smooth surface. Erythrocyte fixation and platelet adhesion experiments showed that the 3D composite scaffold had excellent blood compatibility. Further degradation studies showed that loose structures appeared after 1 week, and structural defects began after 3 weeks. The in vitro degradation results showed that the degradation rate of the BC membrane in simulated body fluid after 6 weeks was 14.38%, while the degradation rate of the PLA/BC composite scaffold was 18.75%.

Development of plant extract impregnated bacterial cellulose as a green antimicrobial composite for potential biomedical applications

The current study was designed to develop cost effective antibacterial bacterial cellulose (BC) composites without following the traditional method of metal nanoparticles or drug incorporation. Briefly, the waste of tomato was employed as the main carbon source instead of commonly used commercial glucose for BC synthesis by Gluconacetobacter hansenii . Further the bioactive extract of Dracaena serrulata (D. serrulata ) plant was impregnated into BC and the resulting BC- D. serrulata (BC-D) composites were investigated for their physicochemical and biological features. Field emission scanning electron microscopy (FE-SEM) micrographs illustrated the successful impregnation of plant extracts in between the BC fibers. Fourier Transform Infrared Spectroscopy (FTIR) and X-ray diffraction (XRD) analysis further confirmed the BC-D fabrication. Synthesized BC-D composites were able to withhold 115 % water of its dry weight. The antibacterial activities of BC-D composite were investigated against Escherichia coli and Staphylococcus aureus pathogens. A moderate level of activity was displayed at the extract level in MIC assays. BC-D composite displayed an inhibition zone of 0.7 mm and 0.5 mm against S. aureus and against E. coli, respectively . Besides moderate level of activity at extract level, BC-D composites exhibited impressive antibacterial activity where BC-D reduced the growth of S. aureus and E. coli from 70 % to 75 % in their live cell density while observed through optical density method. Moreover, this is the first study of exploring the antibacterial characteristics of D. serrulata plant extract and their composite with BC, which could be of vital significance for researchers to develop green biomedical materials . Furthermore, utilization of such wastes for bioproduct development can highly reduce the environmental risks associated with waste management and disposal. • Bacterial cellulose was produced from tomatoes waste. • The Dracaena serrulata leaves extract and bacterial cellulose were mixed to form composite. • Improved physical properties of BC composite were observed as compared to pure BC. • Adequate antibacterial characteristic was achieved with the use of Dracaena serrulata extract with MIC of 12.5 mg/mL.

Fast-growing cyanobacteria bio-embedded into bacterial cellulose for toxic metal bioremediation

Cyanobacterial biomass and cellulose-based materials have been used separately as green bio-adsorbents for the removal of toxic metals from water. Hybrid materials made of living microbial cells encased in a solid matrix have shown good potential for bioremediation. Here, the fast-growing cyanobacterium Synechococcus elongatus UTEX 2973 was embedded in situ into bacterial cellulose (BC), a robust biopolymer rich in hydroxyl groups with excellent water holding capacity. The living material was obtained by injecting S. elongatus into a Komagataeibacter sucrofermentans culture producing BC. Several types of BC/S. elongatus (BC/SE) materials were developed including small spheroids and flat films with different cyanobacteria loads via simple adjustments of the biosynthesis process parameters. BC/SE spheroids were evaluated for toxic copper removal and exhibited excellent adsorption properties compared to pure BC with a maximum capacity of 156.25 mg g−1. Thus, this simple bio-embedding approach holds promises in the development of living materials for environmental applications.