Novel bacterial cellulose membrane biosynthesized by a new and highly efficient producer Komagataeibacter rhaeticus TJPU03

Enhanced bacterial cellulose production by indigenous isolates: Insights from mutagenesis and evolutionary techniques

Bacterial cellulose, with mechanical strength, high water absorption, and crystallinity, is used in eco-friendly packaging, wound dressings, and drug delivery systems. Despite its potential, industrial-scale production is limited by inefficiency and high costs, requiring high-yield strains and optimized growth conditions. This study found that indigenous isolates produce superior bacterial cellulose compared to standard strains. Using UV mutagenesis and Adaptive Laboratory Evolution (ALE), production efficiency increased over sixfold. Strains isolated from vinegar were screened and genetically tested, revealing a strain closely related (99.85 %) to Komagataeibacter sucrofermentans (NCBI code AJ007698). This strain, designated PP177480, achieved a productivity of 9.3 g/L, surpassing the standard strain's (K. xylinus PTCC 1734) yield of 1.31 g/L. Scanning electron microscopy (SEM) showed larger nanopore sizes in the cellulose structure of the selected strain. X-ray Diffraction (XRD) analysis confirmed that bacterial cellulose from both strains is similar to cellulose I, with crystallite sizes of 25 nm for the selected strain and 12.9 nm for the standard strain. Crystallinity percentages were 62.45 % for the selected strain and 72.52 % for the standard strain, and Fourier-transform infrared spectroscopy (FTIR) showed only a slight increase in the amorphous region of the selected strain.

Characterization of nanosilver antibacterial bacterial cellulose composite membranes coated with montmorillonite and their potential application in food packaging

Bacterial cellulose (BC) is a natural, renewable polymer material with an ultrafine nanonetwork structure. However, BC has limited applications in food packaging and medical materials because of its lack of antibacterial properties. To expand the applications of BC, a new BC composite membrane was synthesized via an ex situ method. The BC membrane was first immersed in 100 mL of deionized water containing 3 mg of AgNO₃ for 24 h to incorporate silver nanoparticles (AgNPs). The BC-Ag composite was immersed in a 2 wt% montmorillonite (MMT) solution for 24 h to prepare the BC-Ag-MMT composite membrane. The structure and antibacterial properties of the composite were then examined. Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) confirmed the successful synthesis of the BC-Ag-MMT composite membrane. The results revealed that the addition of AgNPs and MMT resulted in a significant decrease in porosity (13.23 ± 1.12 %), water vapor transmission rate (735.12 ± 12.55 g/(m2·day)), and oxygen permeability (2.28 ± 0.29 g/(s·m2Pa)) while increasing the membrane thickness (0.89 ± 0.08 mm). The incorporation of MMT into BC notably improved the thermal stability of the membrane and further influenced its porosity. The antibacterial activity was evaluated via the inhibition zone method. The BC-Ag-MMT composite membrane exhibited antibacterial activity against Salmonella paratyphi A, Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Salmonella enterica. These findings demonstrated that the BC-Ag-MMT composite membrane possesses exceptional physical and chemical properties, mechanical strength, and antibacterial efficacy. The composite membrane holds significant potential for applications in food packaging.

Bacterial cellulose materials in sustainable energy devices: A review

This article provides a comprehensive review of the processing and applications of bacterial cellulose (BC) for energy conversion and storage devices. These emerging technologies enable the transformation of sustainable energy sources into electricity. Once converted, energy storage devices are vital for stable energy supply. To promote green manufacturing practices in this field, bio-based materials are explored as alternative materials for energy devices, addressing the growing demand for sustainable solutions. From a research and development perspective, the materials chosen for energy devices must exhibit exceptional mechanical, electrical, and thermal properties, along with the necessary chemical reactivity to unlock new applications. Furthermore, for successful commercialization and industrialization, these materials must be suitable for large-scale production within practical timeframes. BC fulfills all of these requirements. The review begins with an overview of BC growth, detailing the composition and operating parameters of the culture medium and the design of bioreactors for large-scale production. It then defines and summarizes both in-situ and ex-situ modifications and processing strategies, offering a comprehensive perspective on these techniques. Unique and interesting properties linking BC's structure to its properties are reviewed to demonstrate its potential as a substitute for benchmark materials. The exceptional performance and synergistic effects of BC-derived hybrid materials highlight their potential for state-of-the-art applications in energy devices, and are suitable for the next-generation energy devices. The papers reviewed in this work have gained significant attention and been widely cited over the past 10 years for their relevance to various practical applications, allowing readers to have a better understanding in development of BC based materials for energy conversion and conversion devices.

Enhanced bacterial cellulose production by Komagataeibacter species and Hibiscus sabdariffa herbal tea

This study proposed Hibiscus sabdariffa as a novel substrate for BC production with Komagataeibacter species and their consortia. K. intermedius is found as the most efficient producer (5.98 g/L BC, 3.56 × 10-2 g-1 h-1 productivity rate) following K. maltaceti (4.44 g/L BC, 2.64 × 10-2 g-1 h-1 productivity rate) and K. nataicola (3.67 g/L BC, 2.18 × 10-2 g-1 h-1 productivity rate). Whereas agitation increased BC production with K. nataicola (1.22-fold, 4.49 g/L BC), K. maltaceti (1.24-fold, 5.52 g/L BC) and K. intermedius (1.27-fold, 7.63 g/L BC), irregular shaped BC was obtained. This could be a novel result as Komagataeibacter consortia increased BC production by 1.17-2.01-fold compared to monocultures resulting as 8.11 g/L BC through the co-cultivation of K. maltaceti-K. intermedius. Maximum increase was found to be 1.75-fold (1.79-fold WHC), occurring with monoculture of K. maltaceti, while 1.94-fold (1.26-fold WHC) with K. maltaceti-K. intermedius consortium when H. sabdariffa-based media compared Hestrin-Schramm media. Based on these results, this could be a novel result as H. sabdariffa-based media may replace the use of HS media in BC production by means of a bioactive content-rich plant and obtaining 3-D ultrafine porous structure with high thermal resistant (∼460-500 °C) BC with mono and co-cultivation of Komagataeibacter species to be used in industrial area.

Balancing mechanical property and swelling behavior of bacterial cellulose film by in-situ adding chitosan oligosaccharide and covalent crosslinking with γ-PGA

Bacterial cellulose (BC) is an ideal candidate material for drug delivery, but the disbalance between the swelling behavior and mechanical properties limits its application. In this work, covalent crosslinking of γ-polyglutamic acid (γ-PGA) with the chitosan oligosaccharide (COS) embedded in BC was designed to remove the limitation. As a result, the dosage, time, and batch of COS addition significantly affected the mechanical properties and the yield of bacterial cellulose complex film (BCCF). The addition of 2.25 % COS at the incubation time of 0.5, 1.5, and 2 d increased the Young's modulus and the yield by 5.65 and 1.42 times, respectively, but decreased the swelling behavior to 1774 %, 46 % of that of native BC. Covalent γ-PGA transformed the dendritic structure of BCCF into a spider network, decreasing the porosity and increasing the swelling behavior by 3.46 times. The strategy balanced the swelling behavior and mechanical properties through tunning hydrogen bond, electrostatic interaction, and amido bond. The modified BCCF exhibited a desired behavior of benzalkonium chlorides transport, competent for drug delivery. Thereby, the strategy will be a competent candidate to modify BC for such potential applications as wound dressing, artificial skin, scar-inhibiting patch, and so on.

Effects of Synthesis Parameters on Structure and Antimicrobial Properties of Bacterial Cellulose/Hydroxyapatite/TiO2 Polymer-Ceramic Composite Material

Bacterial cellulose (BC) is a highly pure polysaccharide biopolymer that can be produced by various bacterial genera. Even though BC lacks functional properties, its porosity, three-dimensional network, and high specific surface area make it a suitable carrier for functional composite materials. In the present study, BC-producing bacteria were isolated from kombucha beverage and identified using a molecular method. Two sets of the BC hydrogels were produced in static conditions after four and seven days. Afterwards, two different synthesis pathways were applied for BC functionalization. The first method implied the incorporation of previously synthesized HAp/TiO2 nanocomposite using an immersion technique, while the second method included the functionalization of BC during the synthesis of HAp/TiO2 nanocomposite in the reaction mixture. The primary goal was to find the best method to obtain the functionalized material. Physicochemical and microstructural properties were analyzed by SEM, EDS, FTIR, and XRD methods. Further properties were examined by tensile test and thermogravimetric analysis, and antimicrobial activity was assessed by a total plate count assay. The results showed that HAp/TiO2 was successfully incorporated into the produced BC hydrogels using both methods. The applied methods of incorporation influenced the differences in morphology, phase distribution, mechanical and thermal properties, and antimicrobial activity against Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), Proteus mirabilis (ATCC 12453), and Candida albicans (ATCC 10231). Composite material can be recommended for further development and application in environments that are suitable for diseases spreading.

The biosynthesis of amidated bacterial cellulose derivatives via in-situ strategy

Bacterial cellulose, as a kind of natural biopolymer produced by bacterial fermentation, has attracted wide attention owing its unique physical and chemical properties. Nevertheless, the single functional group on the surface of BC greatly hinders its wider application. The functionalization of BC is of great significance to broaden the application of BC. In this work, N-acetylated bacterial cellulose (ABC) was successfully prepared using K. nataicola RZS01-based direct synthetic method. FT-IR, NMR and XPS confirmed the in-situ modification of BC by acetylation. The SEM and XRD results demonstrated that ABC has a lower crystallinity and higher fiber width compare with pristine 88 BCE % cell viability on NIH-3 T3 cell and near zero hemolysis ratio indicate its good biocompatibility. In addition, the as-prepared acetyl amine modified BC was further treated by nitrifying bacteria to enrich its functionalized diversity. This study provides a mild in-situ pathway to construct BC derivatives in an environmentally friendly way during its metabolism.

Improved production of bacterial cellulose by Komagataeibacter europaeus employing fruit extract as carbon source

Bacterial cellulose (BC) has attracted worldwide attention owing to its tremendous properties and versatile applications. BC has huge market demand, however; its production is still limited hence important to explore the economically and technically feasible bioprocess for its improved production. The current study is based on improving the bioprocess for BC production employing Komagataeibacter europeaus 14148. Physico-chemical parameters have been optimized e.g., initial pH, incubation temperature, incubation period, inoculum size, and carbon source for maximum BC production. The study employed crude and/or a defined carbon source in the production medium. Hestrin and Schramm (HS) medium was used for BC production with initial pH 5.5 at 30 °C after 7 days of incubation under static conditions. The yield of BC obtained from fruit juice extracted from orange, papaya, mango and banana were higher than other sugars employed. The maximum BC yield of 3.48 ± 0.16 g/L was obtained with papaya extract having 40 g/L reducing sugar concentration and 3.47 ± 0.05 g/L BC was obtained with orange extract having 40 g/L reducing sugar equivalent in the medium. BC yield was about three-fold higher than standard HS medium. Fruit extracts can be employed as sustainable and economic substrates for BC production to replace glucose and fructose.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05451-y.

Mycotoxin Production and the Relationship between Microbial Diversity and Mycotoxins in Pyrus bretschneideri Rehd cv. Huangguan Pear

Mycotoxins are generated by a series of fungal pathogens in postharvest fruit, resulting in serious health threat to consumers and great economic loss to the fruit storage industry. The microbial differences between rotten and healthy fruit during storage and their relationship with mycotoxin production have not been fully studied. In this study, differences in microbial diversity between rotten and healthy fruit after 30 days of storage at ambient temperature were investigated using high-throughput sequencing technology in 'Huangguan' pear (Pyrus bretschneideri Rehd cv. Huangguan) harvested from five different producing regions of Hebei province, China. The bacterial genus Gluconobacter was much more abundant in rotten fruit (76.24%) than that in healthy fruit (32.36%). In addition, Komagataeibacter and Acetobacter were also relatively higher in abundance in rotten fruit. In contrast, bacterial genera Pantoea, Alistipes, Muribaculaceae, Lactobacillus, and Ruminococcaceae_UCG were found to be more abundant in healthy fruit. Fungal genera including Botryosphaeria, Colletotrichum, Valsa, Alternaria, Rosellinia, Fusarium, and Trichothecium were found to be abundant in rotten fruit. The results of principal coordinate analysis (PCoA) showed that there were significant differences in the microbial diversity of different regions. PAT (patulin) was detected in all rotten fruit samples, while tenuazonic acid (TeA), alternariol (AOH), and alternariolmonomethyl ether (AME) were only detected in samples collected from one region (Weixian). Canonical correlation analysis (CCA) and Pearson correlation analysis showed that the abundance of Alistipes and Pantoea were negatively correlated with the contents of PAT, suggesting that bacterial genera Alistipes and Pantoea have potential in reducing mycotoxin production in 'Huangguan' pear.

Bacterial cellulose biopolymers: The sustainable solution to water-polluting microplastics

Microplastics (MPs) pollution has become one of our time's most consequential issue. These micropolymeric particles are ubiquitously distributed across all natural and urban ecosystems. Current filtration systems in wastewater treatment plants (WWTPs) rely on non-biodegradable fossil-based polymeric filters whose maintenance procedures are environmentally damaging and unsustainable. Following the need to develop sustainable filtration frameworks for MPs water removal, years of R&D lead to the conception of bacterial cellulose (BC) biopolymers. These bacterial-based naturally secreted polymers display unique features for biotechnological applications, such as straightforward production, large surface areas, nanoporous structures, biodegradability, and utilitarian circularity. Diligently, techniques such as flow cytometry, scanning electron microscopy and fluorescence microscopy were used to evaluate the feasibility and characterise the removal dynamics of highly concentrated MPs-polluted water by BC biopolymers. Results show that BC biopolymers display removal efficiencies of MPs of up to 99%, maintaining high performance for several continuous cycles. The polymer's characterisation showed that MPs were both adsorbed and incorporated in the 3D nanofibrillar network. The use of more economically- and logistics-favourable dried BC biopolymers preserves their physicochemical properties while maintaining high efficiency (93-96%). These polymers exhibited exceptional structural preservation, conserving a high water uptake capacity which drives microparticle retention. In sum, this study provides clear evidence that BC biopolymers are high performing, multifaceted and genuinely sustainable/circular alternatives to synthetic water treatment MPs-removal technologies.

Optimization and physicochemical characterization of bacterial cellulose by Komagataeibacter nataicola and Komagataeibacter maltaceti strains isolated from grape, thorn apple and apple vinegars

Bacterial cellulose (BC) is a valuable biopolymer that is increasingly used in medical, pharmaceutical and food industries with its excellent physicochemical properties as high water-holding capacity, nanofibrillar structure, large surface area, porosity, mechanical strength and biocompatibility. Accordingly, the isolation, identification and characterization of potent BC producers from grape, thorn apple and apple vinegars were performed in this study. The strains isolated from grape and apple vinegars were identified as Komagataeibacter maltaceti and the strain isolated from thorn apple vinegar was identified as Komagataeibacter nataicola with 16S rRNA analysis. Optimized conditions were found as 8% dextrin, 1.5% (peptone + yeast extract) and 10% inoculation amount at pH 6.0 with a productivity rate of 1.15 g/d/L, a yield of 8.06% and a dry weight of 6.45 g/L for K. maltaceti, and 10% maltose, 1% (peptone + yeast extract) and 10% inoculation amount at pH 6.0 with a productivity rate of 0.96 g/L/d, a yield of 5.35% and a dry weight of 5.35 g/L for K. nataicola. Obtained BC from K. maltaceti and K. nataicola strains was more than 2.56- and 1.86-fold when compared with BC obtained from HS media and exhibited 95.1% and 92.5% WHC, respectively. Based on the characterization results, BC pellicles show characteristic FT-IR bands and have ultrafine 3D structures with high thermal stability. By means of having ability to assimilate monosaccharides, disaccharides and polysaccharide used in this study, it is predicted that both isolated Komagataeibacter species can be used in the production of biopolymers from wastes containing complex carbon sources in the future.

Ecofriendly green biosynthesis and characterization of novel bacteriocin-loaded bacterial cellulose nanofiber from Gluconobacter cerinus HDX-1

A new strain of bacterial cellulose (BC)-producing Gluconobacter cerinus HDX-1 was isolated and identified, and a simple, low-cost complexation method was used to biosynthesis Lactobacillus paracasei 1∙7 bacteriocin BC (BC-B) nanofiber. The structure and antibacterial properties of the nanofibers were evaluated. Solid-state nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR) and x-ray diffraction (XRD) analysis showed that BC and BC-B nanofibers had typical crystalline form of the cellulose I. X-ray photoelectron spectrometer (XPS), scanning electron microscope (SEM) and atomic force microscopy (AFM) revealed that the bacteriocin and BC were successfully compounded, and the structure of BC-B nanofiber was tighter than BC nanofiber, with lower porosity, swelling ratio and water vapor transmission rate (WVTR). The tensile strength and Young's modulus of BC-B nanofibers were 13.28 ± 1.26 MPa and 132.10 ± 4.92 MPa, respectively, higher than that of BC nanofiber (6.12 ± 0.87 MPa and 101.59 ± 5.87 MPa), indicating that bacteriocin enhance the mechanical properties of BC nanofiber. Furthermore, the BC-B nanofibers exhibited significant thermal stability, antioxidant capacity and antibacterial activity than BC nanofiber. Therefore, bacteriocin-loaded BC nanofiber may be used as antimicrobial agents in active food packaging and medical material.

Structural changes of bacterial cellulose due to incubation in conditions simulating human plasma in the presence of selected pathogens

Bacterial nanocellulose (BNC) is a natural biomaterial with a wide range of medical applications. However, it cannot be used as a biological implant of the circulatory system without checking whether it is biodegradable under human plasma conditions. This work aimed to investigate the BNC biodegradation by selected pathogens under conditions simulating human plasma. The BNC was incubated in simulated biological fluids with or without Staphylococcus aureus, Candida albicans and Aspergillus fumigatus, and its physicochemical properties were studied. The results showed that the incubation of BNC in simulated body fluid with A. fumigatus contributes more to its degradation than that under other conditions tested. The rearrangement of the hydrogen-bond network in this case resulted in a more compact structure, with an increased crystallinity index, reduced thermal stability and looser cross-linking. Therefore, although BNC shows great potential as a cardiovascular implant material, before use for this purpose its biodegradability should be limited.

In Vitro Efficacy of Bacterial Cellulose Dressings Chemisorbed with Antiseptics against Biofilm Formed by Pathogens Isolated from Chronic Wounds

Local administration of antiseptics is required to prevent and fight against biofilm-based infections of chronic wounds. One of the methods used for delivering antiseptics to infected wounds is the application of dressings chemisorbed with antimicrobials. Dressings made of bacterial cellulose (BC) display several features, making them suitable for such a purpose. This work aimed to compare the activity of commonly used antiseptic molecules: octenidine, polyhexanide, povidone-iodine, chlorhexidine, ethacridine lactate, and hypochlorous solutions and to evaluate their usefulness as active substances of BC dressings against 48 bacterial strains (8 species) and 6 yeast strains (1 species). A silver dressing was applied as a control material of proven antimicrobial activity. The methodology applied included the assessment of minimal inhibitory concentrations (MIC) and minimal biofilm eradication concentration (MBEC), the modified disc-diffusion method, and the modified antibiofilm dressing activity measurement (A.D.A.M.) method. While in 96-well plate-based methods (MIC and MBEC assessment), the highest antimicrobial activity was recorded for chlorhexidine, in the modified disc-diffusion method and in the modified A.D.A.M test, povidone-iodine performed the best. In an in vitro setting simulating chronic wound conditions, BC dressings chemisorbed with polyhexanide, octenidine, or povidone-iodine displayed a similar or even higher antibiofilm activity than the control dressing containing silver molecules. If translated into clinical conditions, the obtained results suggest high applicability of BC dressings chemisorbed with antiseptics to eradicate biofilm from chronic wounds.