In Vivo Modification of Microporous Structure in Bacterial Cellulose by Exposing Komagataeibacter xylinus Culture to Physical and Chemical Stimuli

Bacterial cellulose (BC) samples were obtained in a static culture of K. xylinus under the effect of a low-intensity magnetic field, UV light, NaCl, and chloramphenicol. The effect of such stimuli on the amount of BC produced and its production rate, specific area, pore volume, and pore diameter were evaluated. The polysaccharide production was enhanced 2.28-fold by exposing K. xylinus culture to UV light (366 nm) and 1.7-fold by adding chloramphenicol (0.25 mM) to the medium in comparison to BC control. All the stimuli triggered a decrease in the rate of BC biosynthesis. BC membranes were found to be mesoporous materials with an average pore diameter from 21.37 to 25.73 nm. BC produced under a magnetic field showed the lowest values of specific area and pore volume (2.55 m² g⁻¹ and 0.024 cm³ g⁻¹), while the BC synthesized in the presence of NaCl showed the highest (15.72 m² g⁻¹ and 0.11 cm³ g⁻¹). FTIR spectra of the BC samples also demonstrated changes related to structural order. The rehydration property in these BC samples is not mainly mediated by the crystallinity level or porosity. In summary, these results support that BC production, surface, and structural properties could be modified by manipulating the physical and chemical stimuli investigated.

Preparation of Komagataeibacter xylinus Inoculum for Bacterial Cellulose Biosynthesis Using Magnetically Assisted External-Loop Airlift Bioreactor

The aim of this study was to demonstrate the applicability of a novel magnetically assisted external-loop airlift bioreactor (EL-ALB), equipped with rotating magnetic field (RMF) generators for the preparation of Komagataeibacterxylinus inoculum during three-cycle repeated fed-batch cultures, further used for bacterial cellulose (BC) production. The fermentation carried out in the RMF-assisted EL-ALB allowed to obtain an inoculum of more than 200× higher cellular density compared to classical methods of inoculum preparation. The inoculum obtained in the RMF-assisted EL-ALB was characterized by a high and stable metabolic activity during repeated batch fermentation process. The application of the RMF-assisted EL-ALB for K. xylinus inoculum production did not induce the formation of cellulose-deficient mutants. It was also confirmed that the ability of K. xylinus to produce BC was at the same level (7.26 g/L of dry mass), regardless of inoculum age. Additionally, the BC obtained from the inoculum produced in the RMF-assisted EL-ALB was characterized by reproducible water-related properties, mechanical strength, nano-fibrillar structure and total crystallinity index. The lack of any negative impact of inoculum preparation method using RMF-assisted EL-ALB on BC properties is of paramount value for its future applications, including use as a biomaterial in tissue engineering, wound healing, and drug delivery, where especially BC liquid capacity, nanostructure, crystallinity, and mechanical properties play essential roles.

Bacterial Cellulose as a Potential Bio-Scaffold for Effective Re-Epithelialization Therapy

Currently, there are several therapeutic approaches available for wound injury management. However, a better understanding of the underlying mechanisms of how biomaterials affect cell behavior is needed to develop potential repair strategies. Bacterial cellulose (BC) is a bacteria-produced biopolymer with several advantageous qualities for skin tissue engineering. The aim here was to investigate BC-based scaffold on epithelial regeneration and wound healing by examining its effects on the expression of scavenger receptor-A (SR-A) and underlying macrophage behavior. Full-thickness skin wounds were generated on Sprague-Dawley rats and the healing of these wounds, with and without BC scaffolds, was examined over 14 days using Masson’s trichome staining. BC scaffolds displayed excellent in vitro biocompatibility, maintained the stemness function of cells and promoted keratinocyte differentiation of cells, which are vital in maintaining and restoring the injured epidermis. BC scaffolds also exhibited positive in vivo effects on the wound microenvironment, including improved skin extracellular matrix deposition and controlled excessive inflammation by reduction of SR-A expression. Furthermore, BC scaffold significantly enhanced epithelialization by stimulating the balance of M1/M2 macrophage re-programming for beneficial tissue repair relative to that of collagen material. These findings suggest that BC-based materials are promising products for skin injury repair.

Use of Industrial Wastes as Sustainable Nutrient Sources for Bacterial Cellulose (BC) Production: Mechanism, Advances, and Future Perspectives

A novel nanomaterial, bacterial cellulose (BC), has become noteworthy recently due to its better physicochemical properties and biodegradability, which are desirable for various applications. Since cost is a significant limitation in the production of cellulose, current efforts are focused on the use of industrial waste as a cost-effective substrate for the synthesis of BC or microbial cellulose. The utilization of industrial wastes and byproduct streams as fermentation media could improve the cost-competitiveness of BC production. This paper examines the feasibility of using typical wastes generated by industry sectors as sources of nutrients (carbon and nitrogen) for the commercial-scale production of BC. Numerous preliminary findings in the literature data have revealed the potential to yield a high concentration of BC from various industrial wastes. These findings indicated the need to optimize culture conditions, aiming for improved large-scale production of BC from waste streams.

Bacterial cellulose production, properties and applications with different culture methods - A review

Bacterial cellulose (BC) is an organic compound produced by certain types of bacteria. In natural habitats, the majority of bacteria synthesize extracellular polysaccharides, such as cellulose, which form protective envelopes around the cells. Many methods are currently being investigated to enhance cellulose growth. The various celluloses produced by different bacteria possess different morphologies, structures, properties, and applications. However, the literature lacks a comprehensive review of the different methods of BC production, which are critical to BC properties and their final applications. The aims of this review are to provide an overview of the production of BC from different culture methods, to analyze the characteristics of particular BC productions, to indicate existing problems associated with different methods, and to choose suitable culture approaches for BC applications in different fields. The main goals for future studies have also been discussed here.