Comparison of bacterial cellulose production by Gluconacetobacter xylinus on bagasse acid and enzymatic hydrolysates

Effect of in-situ biochemical modification on the synthesis, structure, and function of xanthan gum based bacterial cellulose generated from Tieguanyin oolong tea residue hydrolysate

The effect of in-situ biochemical modification on the synthesis, structure, and function of xanthan gum based bacterial cellulose generated from Tieguanyin oolong tea residue hydrolysate was evaluated for the first time. This modification could overcome the inhibitory effect of the hydrolysate and the bacterial cellulose yield with 0.6% xanthan gum addition increased by 260.8% compared with that without xanthan gum addition. Bacterial cellulose and xanthan gum were combined by the in-situ modification and the alteration of fermentation medium rheological properties by xanthan gum addition might be beneficial for their combination. The average diameter of the bacterial cellulose microfibrils was increased by the modification, and it had a great influence on the crystalline structure of the bacterial cellulose. Additionally, both the water absorption and texture properties of the bacterial cellulose was strengthened by the modification. Overall, this modification showed great potential for efficient and effective xanthan gum based bacterial cellulose production.

Bacterial nanocellulose production using Cantaloupe juice, statistical optimization and characterization

The bacterial nanocellulose has been used in a wide range of biomedical applications including carriers for drug delivery, blood vessels, artificial skin and wound dressing. The total of ten morphologically different bacterial strains were screened for their potential to produce bacterial nanocellulose (BNC). Among these isolates, Bacillus sp. strain SEE-3 exhibited potent ability to produce the bacterial nanocellulose. The crystallinity, particle size and morphology of the purified biosynthesized nanocellulose were characterized. The cellulose nanofibers possess a negatively charged surface of - 14.7 mV. The SEM images of the bacterial nanocellulose confirms the formation of fiber-shaped particles with diameters of 20.12‒47.36 nm. The TEM images show needle-shaped particles with diameters of 30‒40 nm and lengths of 560‒1400 nm. X-ray diffraction show that the obtained bacterial nanocellulose has crystallinity degree value of 79.58%. FTIR spectra revealed the characteristic bands of the cellulose crystalline structure. The thermogravimetric analysis revealed high thermal stability. Optimization of the bacterial nanocellulose production was achieved using Plackett-Burman and face centered central composite designs. Using the desirability function, the optimum conditions for maximum bacterial nanocellulose production was determined theoretically and verified experimentally. Maximum BNC production (20.31 g/L) by Bacillus sp. strain SEE-3 was obtained using medium volume; 100 mL/250 mL conical flask, inoculum size; 5%, v/v, citric acid; 1.5 g/L, yeast extract; 5 g/L, temperature; 37 °C, Na₂HPO₄; 3 g/L, an initial pH level of 5, Cantaloupe juice concentration of 81.27 percent and peptone 11.22 g/L.

Exploration of a novel and efficient source for production of bacterial nanocellulose, bioprocess optimization and characterization

The demand for bacterial nanocellulose is expected to rise in the coming years due to its wide usability in many applications. Hence, there is a continuing need to screen soil samples from various sources to isolate a strain with a high capacity for bacterial nanocellulose production. Bacillus sp. strain SEE-12, which was isolated from a soil sample collected from Barhiem, Menoufia governorate, Egypt, displayed high BNC production under submerged fermentation. Bacillus sp. strain SEE-12 was identified as Bacillus tequilensis strain SEE-12. In static cultures, BNC was obtained as a layer grown in the air liquid interface of the fermentation medium. The response surface methodology was used to optimise the process parameters. The highest BNC production (22.8 g/L) was obtained using 5 g/L peptone, 5 g/L yeast extract, 50%, v/v Cantaloupe juice, 5 g/L Na₂HPO₄, 1.5 g/L citric acid, pH 5, medium volume of 100 mL/250 mL conical flask, inoculum size 5%, v/v, temperature 37 °C and incubation time 6 days. The BNC was purified and characterized by scanning electron microscopy (SEM), Energy-dispersive X-ray (EDX) spectroscopy, differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and transmission electron microscopy (TEM).

Bacterial Cellulose Production from agricultural Residues by two Komagataeibacter sp. Strains

Agricultural residues are constantly increasing with increased farming processes, and improper disposal is detrimental to the environment. Majority of these waste residues are rich in lignocellulose, which makes them suitable substrate for bacterial fermentation in the production of value-added products. In this study, bacterial cellulose (BC), a purer and better form of cellulose, was produced by two Komagataeibacter sp. isolated from rotten banana and kombucha drink using corncob (CC) and sugarcane bagasse (SCB) enzymatic hydrolyzate, under different fermentation conditions, that is, static, continuous, and intermittent agitation. The physicochemical and mechanical properties of the BC films were then investigated by Fourier Transformed Infrared Spectroscopy (FTIR), Thermogravimetry analysis, Field Emission Scanning Electron Microscopy (FE-SEM), and Dynamic mechanical analysis. Agitation gave a higher BC yield, with Komagataeibacter sp. CCUG73629 producing BC from CC with a dry weight of 1.6 g/L and 1.4 g/L under continuous and intermittent agitation, respectively, compared with that of 0.9 g/L in HS medium. While BC yield of dry weight up to 1.2 g/L was obtained from SCB by Komagataeibacter sp. CCUG73630 under continuous agitation compared to that of 0.3 g/L in HS medium. FTIR analysis showed BC bands associated with cellulose I, with high thermal stability. The FE-SEM analysis showed that BC fibers were highly ordered and densely packed. Although the BC produced by both strains showed similar physicochemical and morphological properties, the BC produced by the Komagataeibacter sp. CCUG73630 in CC under intermittent agitation had the best modulus of elasticity, 10.8 GPa and tensile strength, 70.9 MPa.

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: From production optimization to new applications

Bacterial cellulose (BC) is a biopolymer of great significance to the medical, pharmaceutical, and food industries. However, a high concentration of carbon sources (mainly glucose) and other culture media components is usually required to promote a significant yield of BC, which increases the bioprocess cost. Thus, optimization strategies (conventional or statistical) have become relevant for the cost-effective production of bacterial cellulose. Additionally, this biopolymer may present new properties through modifications with exogenous compounds. The present review, explores and discusses recent studies (last five years) that report the optimization of BC production and its yield as well as in situ and ex situ modifications, resulting in improved mechanical, antioxidant, and antimicrobial properties of BC for new applications.

Cellulose from sources to nanocellulose and an overview of synthesis and properties of nanocellulose/zinc oxide nanocomposite materials

Recently, environmental and ecological concerns are increasing due to the usage of petroleum-based products so the synthesis of ultra-fine chemicals and functional materials from natural resources is drawing a tremendous level of attention. Nanocellulose, a unique and promising natural material extracted from native cellulose, may prove to be most ecofriendly materials that are technically and economically feasible in modern times, minimizing the pollution generation. Nanocellulose has gained tremendous attention for its use in various applications, due to its excellent special surface chemistry, physical properties, and remarkable biological properties (biodegradability, biocompatibility, and non-toxicity). Various types of nanocellulose, viz. cellulose nanofibrils (CNFs), cellulose nanocrystals (CNCs), and bacterial nanocellulose (BNC), are deeply introduced and compared in this work in terms of sources, production, structures and properties. The metal and metal oxides especially zinc oxide nanoparticles (ZnO-NPs) are broadly used in various fields due to the diversity of functional properties such as antimicrobial and ultraviolet (UV) properties. Thus, the advancement of nanocellulose and zinc oxide nanoparticles (ZnO-NPs)-based composites materials are summarized in this article in terms of the preparation methods and remarkable properties with the help of recent knowledge and significant findings (especially from the past six years reports). The nanocellulose materials complement zinc oxide nanoparticles, where they impart their functional properties to the nanoparticle composites. As a result hybrid nanocomposite containing nanocellulose/zinc oxide composite has shown excellent mechanical, UV barrier, and antibacterial properties. The nanocellulose based hybrid nanomaterials have huge potential applications in the area of food packaging, biopharmaceuticals, biomedical, and cosmetics. Thus the functional composite materials containing nanocellulose and zinc oxide will determine the potential biomedical application for nanocellulose.

Calcium Phosphate Incorporated Bacterial Cellulose-Polyvinylpyrrolidone Based Hydrogel Scaffold: Structural Property and Cell Viability Study for Bone Regeneration Application

This work focuses on the analysis of structural and functional properties of calcium phosphate (CaP) incorporated bacterial cellulose (BC)-polyvinylpyrrolidone (PVP) based hydrogel scaffolds referred to as “CaP/BC-PVP”. CaP is incorporated in the scaffolds in the form of hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) in different concentrations (β-TCP: HA (w/w) = 20:80, 40:60, and 50:50). The scaffolds were characterized on the basis of porosity, thermal, biodegradation, mechanical, and cell viability/cytocompatibility properties. The structural properties of all the hydrogel scaffolds show significant porosity. The biodegradation of “CaP/BC-PVP” scaffold was evaluated following hydrolytic degradation. Weight loss profile, pH change, scanning electron microscopy (SEM), and Fourier Transform Infrared Spectroscopy (FTIR) study confirm the significant degradability of the scaffolds. It is observed that a 50:50_CaP/BC-PVP scaffold has the highest degree of degradation. On the other hand, the compressive strengths of CaP/BC-PVP hydrogel scaffolds are found between 0.21 to 0.31 MPa, which is comparable with the human trabecular bone. The cell viability study is performed with a human osteosarcoma Saos-2 cell line, where significant cell viability is observed in all the hydrogel scaffolds. This indicated their ability to facilitate cell growth and cell proliferation. Considering all these substantial properties, CaP/BC-PVP hydrogel scaffolds can be suggested for detailed investigation in the context of bone regeneration application.

Isothermal Crystallization and Rheology Properties of Isotactic Polypropylene/Bacterial Cellulose Composite

Bacterial cellulose (BC) is a new kind of cellulose with great potential in enhancing preparation of isotactic Polypropylene (iPP) composites, which have been found with excellent performance. However, the interface compatibility between BC and iPP is poor. In this study, iPP/BC composites were prepared by solution mixing. Esterification modified BC (CO) and Maleic anhydride grafted polypropylene (MAPP) added as a compatibilizer was both used to improve the interfacial compatibility of the iPP/BC composites. The rheology and isothermal crystallization behavior of the composites was tested and discussed. The result shows that the complex viscosity and storage modulus of the composite significantly increase in the rule iPP, iPP/BC2, iPP/CO2, and M-iPP/BC3, which indicates that the compatibility of the composite increases as this rule. According to the isothermal crystallization kinetics result, the crystal growth mode of iPP was not affected by the addition of BC and the interfacial compatibility. The spherulite growth rate of the iPP/BC composite increases with increasing crystallization temperature. Especially, the value decreases as the same rule with the complex viscosity and storage modulus of the composite at the same isothermal crystallization temperature. These results suggest that the interface compatibility of iPP/BC composites is greatly improved and the interface compatibility of the M-iPP/BC3 is better than the iPP/CO2.