Effect of Bacterial Cellulose (BC) Formation on Various Substrate Variations and Combinations

Nata de coco is a fermented product made from coconut water. Acetobacter xylinum is used in coconut water fermentation to produce very fine cellulose fibers. This study aims to observe the bacterial cellulose (BC) formation with various carbon sources using the Real-Time Image Processing approach. Fermentation is stopped when the BC reaches a certain thickness. A set of tools have been modified to perform fermentation, such as using Raspberry Pi, Arduino sensors, USB Web Camera, and building a BC growth monitoring database that is integrated with PHP. The results showed the highest correlation between time and thickness for glucose, sucrose and mannitol mediums. Cluster analysis showed that glucose had three clusters, while sucrose and mannitol had two groups. The kinetic observations of BC growth on glucose, sucrose, and mannitol mediums follow the Gompertz model equation. The conclusions obtained are that glucose had the fastest adaptation phase, followed by sucrose, and mannitol. Mannitol was referred to as the carbon sources that had the longest BC formation.

Bacterial cellulose (BC) is high purity and several current potential uses in industries. Liquid byproduct of sweet corn canning process (SC) contains fermentable sugars which could be utilized to get higher economic benefits. Therefore, this research aimed to produce BC from SC by Gluconacetobacter xylinus under static condition and use it to improve mechanical properties of natural rubber. The ratio of SC to coconut juice for cellulose production was studied. The result revealed that production yield, water holding capacity and tensile strength of BC produced from the medium containing coconut juice to SC at a ratio of 75:25 (w/w) supplemented with 1% acetic acid, 1% ammonium sulfate and 5% sucrose (w/w) was not significant different from BC obtained from a coconut juice medium. The FTIR spectra of BC showed the characteristics of cellulose. The morphology of BC exhibited high fibril network. BC is showed reinforcement in natural rubber composites due to enhance the stress value, whereas reduce the strain value.

Effects of different hydrocolloids on the production of bacterial cellulose by Acetobacter xylinum using Hestrin–Schramm medium under anaerobic condition

MORPHOLOGICAL AND THERMAL PROPERTIES OF ALKALI TERATED BACTERIAL CELLULOSE FROM COCONUT WATER . Alkali treatment is one ofwide chemical treatment for removing non cellulosic materials and other impurities of bacterial cellulose (BC). Presently, BC produced by synthetic medium such as Schramm Hestrin or coconut water fermentation using pure culture of Acetobacter xylinum . In this research BC produced from coconut water fermentation using inoculums as suspension of mixture culture of bacteria A. xylinum in coconut water which commercialised inWest Java (Cianjur). Purpose of this research is to know the native and the effect of alkali treatment on the BC (heterofermentive) with evaluation of morphological, elemental analysis and thermal properties by Scanning ElectronMicroscope (SEM)-Energy Dispersive X-ray Spectroscopy (EDX) and Thermo-Gravimetry Analysis (TGA), respectively. Observation on morphological surface of native BC showes that there were noncellulosic materials entangled on the network of cellulose fibrils whichwere identified by EDX analysis as sodium(Na),magnesium(Mg), aluminium (Al), silica (Si) and potassium (K) in addition to carbon (C) and oxygen(O). On thermal analysis, stepwise of decomposition are observed on the native BC indicating the presence of non-cellulosic components which decomposed at different temperatures.While the alkali- treated BC sheet shows a single decomposition stage. The amount of residue formed after alkali treatment was relatively lower than native BC. Thermal degradation properties of the BC produced from coconut water was higher than that of BC belonging to synthetic medium. Based on this data, it is concluded that alkali treated cellulose can be used as a reasonable substitute for various non biodegradable synthetic polymers for large scale industrial in specific application

Bacterial cellulose is a remarkable fibrous structural component of biofilms, as it forms a mechanically strong hydrogel with high water adsorption capabilities. Additionally, bacterial cellulose is biocompatible and therefore of potential interest for skin regeneration and wound healing applications. However, bacterial cellulose produced through conventional production processes at water–air interfaces lack macroporosity control, which is crucial for regenerative tissue applications. Here we demonstrate a straightforward and efficient approach to form a macroporous bacterial cellulose foam by foaming a mannitol-based media with a bacterial suspension of Gluconoacetobacter xylinus. The bacterial suspension foam is stabilized with Cremodan as a surfactant and viscosified with Xanthan preventing water drainage. Further foam stabilization occurs through cellulose formation across the foam network. As bacterial cellulose formation is influenced by the viscosity of the growth media, we fine-tuned the concentration of Xanthan to allow for bacterial cellulose formation while avoiding water drainage caused by gravity. With this simple approach, we were able to design 3D bacterial cellulose foams without any additional processing steps. We argue that this templating approach can further be used to design foamy biofilms for biotechnological approaches, increasing the surface area and therefore the yield by improving the exchange of nutrients and metabolic products.

New biocomposites based on thermoplastic starch and bacterial cellulose

Bacterial cellulose (BC) has a basic cellulose structure that gives high purity, high crystalline ability, high mechanical strength, and high water holding capacity. During the last few decades, BC has gained as an important biomaterial because of these unique physical and chemical characteristics. BC is synthesized by Acetobacter xylinum extracellularly in a suitable substrate media. Researchers have produced BC using a synthetic media or using coconut water and inoculating with Acetobacter xylinum in a static fermentation system. In order to eliminate shortcomings in static fermentation and to achieve increased cellulose production, agitated and aerated fermentation systems were experimented. Rotating Biological Fermentor (RBF) is an is aerated and agitated system, which gives continuous oxygen flux to the fermentation medium thereby increasing the yield of biomass and cellulose synthesized. In this study, a mathematical model for the synthesis of BC in a RBF system was developed. The growth of cellulose is considered as a biofilm from a mono culture. Glucose depletion, cellulose production and microbial growth in the fermentation medium were explained using the developed models. It was shown that the simulated and experimental results were in close agreement. In addition, the model was successful in predicting yield of cellulose at different rotational speeds of the RBF unit.

Mannose constitutes a principal component in numerous biomass hemicelluloses; however, its utilization by the cellulose-producing bacterium Komagataeibacter xylinus is inefficient. Consequently, during biorefinery and the transformation of biomass rich in mannose for the production of the high-value biological product, bacterial cellulose (BC), the biomass components cannot be fully utilized, leading to resource wastage. Moreover, inappropriate discharge of the fermentation effluent may also result in environmental pollution. This study addressed the underutilization of mannose in spent coffee grounds (SCGs) by introducing a fusion vector expressing mannokinase and phosphomannose isomerase into K. xylinus ATCC 23770, thereby enhancing mannose utilization in this strain model. SCG was pretreated with concentrated sulfuric acid to disrupt crystalline structures, followed by enzymatic hydrolysis to extract saccharides. When culturing in SCG hydrolysate, BC pellicle-derived inoculum achieved 1.2-fold higher BC yield than broth inoculum, attributed to BC matrix protection. The engineered strain K. xylinus CGMCC 31806 demonstrated superior mannose assimilation, yielding 1.5-fold more BC than wild type in simulated SCG medium. In authentic SCG medium without extra nitrogen addition, BC production reached 3.80 g/L, a 1.2- to 2.5-fold increase. The obtained BC exhibited enhanced mechanical properties with 40-84% higher tensile strength and 20-75% increased Young's modulus. This study validates a dual strategy combining agro-waste valorization and targeted strain modification, establishing a collaborative optimization framework linking biomass feedstocks, microbial engineering, and bioprocessing for cost-effective BC production. Future research would utilize existing commercial high-yield strains to replicate the expression strategy of this fusion protein, in order to achieve truly efficient industrial production.IMPORTANCEThe inefficient utilization of mannose, a major hemicellulose component prevalent in biomass by Komagataeibacter xylinus represents a significant bottleneck in the sustainable, cost-effective bioproduction of bacterial cellulose (BC). This underutilization would lead to wasted resources and potential environmental pollution from fermentation effluents. The study directly addresses this critical challenge by pioneering a synergistic "Feedstock-Strain-Process" integration strategy in advancing BC industrialization. We demonstrate the significant impact of engineering K. xylinus for enhanced mannose assimilation coupled with optimized biorefinery of agro-industrial waste, taking mannose-rich spent coffee grounds, as the representative raw material. This integrated approach not only valorizes abundant agricultural waste streams significantly boosting BC yields under nutrient-limited conditions but also generates BC with superior mechanical properties. The study establishes an actionable blueprint for advancing BC industrialization through collaborative optimization of biomass feedstocks, targeted microbial engineering, and process innovation, aligning with the goals of the circular bioeconomy and sustainable material production.

New silver-containing hybrid materials based on bacterial cellulose were obtained by a technological approach that combines three techniques: the formation of bacterial cellulose under static conditions, the modification of its surface by plasma treatment, and the introduction of silver nanoparticles obtained by metal vapor synthesis. The plasma treatment is found to significantly change the morphology and composition of the polymer surface. The oxidation state of silver is shown to correspond to Ag0. The resulting systems exhibit antimicrobial activity.

Microcapsules made of synthetic polymers are used for the release of cargo in agriculture, food, and cosmetics but are often difficult to be degraded in the environment. To diminish the environmental impact of microcapsules, we use the biofilm-forming ability of bacteria to grow cellulose-based biodegradable microcapsules. The present work focuses on the design and optimization of self-grown bacterial cellulose capsules. In contrast to their conventionally attributed pathogenic role, bacteria and their self-secreted biofilms represent a multifunctional class of biomaterials. The bacterial strain used in this work, Gluconacetobacter xylinus, is able to survive and proliferate in various environmental conditions by forming biofilms as part of its lifecycle. Cellulose is one of the main components present in these self-secreted protective layers and is known for its outstanding mechanical properties. Provided enough nutrients and oxygen, these bacteria and the produced cellulose are able to self-assemble at the interface of any given three-dimensional template and could be used as a novel stabilization concept for water-in-oil emulsions. Using a microfluidic setup for controlled emulsification, we demonstrate that bacterial cellulose capsules can be produced with tunable size and monodispersity. Furthermore, we show that successful droplet stabilization and bacterial cellulose formation are functions of the bacteria concentration, droplet size, and surfactant type. The obtained results represent the first milestone in the production of self-assembled biodegradable cellulose capsules to be used in a vast range of applications such as flavor, fragrance, agrochemicals, nutrients, and drug encapsulation.

Bacterial cellulose has high strength and crystallinity, and as such has been suggested as a strategically-useful material that could form the reinforcement phase in composites. In addition to any property improvement, if a biodegradable matrix is reinforced with bacterial cellulose, the entire system should be biodegradable. However, bacterial cellulose is not easily dispersed and thus has not been widely used in such composites. Investigations into the production of bacterial cellulose composites where the cellulose reinforcement component is evenly dispersed is therefore of benefit. Bacterial cellulose can be produced in high quantities by the bacterium Gluconacetobacter xylinus in various media and under various reaction conditions, however altering the growth conditions has been shown to change the yield and properties of the resulting cellulose. Poly-3-hydroxybutyrate (PHB) is a bioplastic that has been hypothesised as a material that could replace traditional plastics, however it is very stiff and brittle. It is possible that its use in a composite with an effective reinforcing phase could improve these properties. Therefore this material was selected as a matrix material to be blended with bacterial cellulose. The examination of growth conditions in this work led to a methodology by which high amounts of cellulose with high crystallinity could be obtained. In addition, methods were determined by which to achieve modified cellulose fibrils. These modifications included cellulose fibrils produced with PHB physically attached to the surface. Solution blending and melt blending techniques were investigated as ways of producing PHB/bacterial cellulose composites. Solution blending was found to produce composites with well dispersed bacterial cellulose, however melt blending was found to degrade samples. It was found that solution blends using cellulose in a ground powder form did not achieve improved properties; however a composite with cellulose in its fibrillar form achieved improved tensile strength and modulus. PHB/bacterial cellulose composites with cellulose in its fibrillar form were produced by dispersing the cellulose fibrils by sonication. Sonication was investigated as a method of harvesting and dispersing bacterial cellulose fibrils in various solvents, including chloroform which could directly dissolve PHB, however only small weights of individual fibrils were obtained in this way. The composite with improved mechanical properties contained 2 wt% cellulose; however it was found that these improvements were observed only if the cellulose was retained in a hydrated never-dried state. Investigations into the biodegradability of PHB and a PHB/bacterial cellulose composite revealed that the composite degraded at a greater rate than neat PHB. This indicates that a bacterial cellulose reinforcement phase is able to assist a PHB matrix to degrade at a faster rate when submerged in compost. It is apparent that techniques can be developed to use bacterial cellulose successfully to confer strength to composites when used as a reinforcing material, as well as increasing the rate of biodegradation of a PHB matrix. Composites of these materials should therefore be considered in the design of biodegradable materials.

Bacterial cellulose (BC) is a non-toxic, high-purity, and biocompatible polymer that is abundant in various bacteria and does not contain lignin, hemicellulose and pectin found in plant cellulose. High concentrations of carbon sources can limit yields of BC. One potential solution to enhance BC production is the use of elicitors like plant extracts; however, the use of plant extracts such as Aloe vera leaf extract remains limited. Therefore, the current study aimed to investigate the effects of Aloe vera leaves on BC properties, glucose consumption, and synthesis rate by Komagataeibacter xylinus to increase BC volumetric production. Aloe vera extract was incorporated into the culture medium (given the conditions used), and BC was analyzed after 5 to 7 days of fermentation. The fermentation process at 30°C showed that increasing Aloe vera extract volume to 30% (v/v) improved glucose consumption, resulting in 3.35 g/L of BC accumulated in culture flasks. Adding different amounts of Aloe vera leaf extracts to the bacteria culture altered the morphology of the BC film and trapped Aloe vera extract inside the BC fibers. The treatment with 30% (v/v) Aloe vera leaf extract also resulted in a less homogeneous Aloe-BC morphological surface structure. The X-ray diffractometer (XRD) crystallinity index of control BC improved from 83.70% to 93.70% compared to the 30% Aloe-BC. According to the IR spectral analysis, the presence of amine groups in dried BC samples is confirmed by the detected absorption in the 1536-1635 cm⁻¹ range, which indicates N–H bending vibrations. In conclusion, including Aloe vera leaf increased glucose intake, enhanced BC biomass, and altered the shape of the BC.

Preparation and characterization of reinforced papers using nano bacterial cellulose

Bacterial cellulose and bacterial cellulose-vaccarin membranes for wound healing

Impregnation of silver nanoparticles into bacterial cellulose for antimicrobial wound dressing