Synthesis Of Bacterial Cellulose Research Articles

Next-generation photodynamic antimicrobial materials made by direct synthesis of functional bacterial cellulose

Bacterial cellulose (BC) regularly uses chemical or physical modifications to produce antimicrobial wound dressings. However, there is a risk of loss of functional components during application. Moreover, a significant hurdle lies in successfully integrating durable and highly effective bactericidal entities with BC. Herein, we successfully synthesized a photodynamic antibacterial cellulose through direct in situ microbial fermentation, incorporating the photosensitizer protoporphyrin IX-modified glucosamine (PPIX-GlcN) into cellulose to form PIXX-BC biopolymers. Excitingly, the PPIX-BC membrane exhibited robust and uniform red fluorescence, which is crucial for monitoring the bacterial fermentation process. Our results demonstrated that the biocompatibility PPIX-BC membrane possessed potent light-triggered photodynamic bactericidal activity, effectively suppressing the growth of E. coli and S. aureus while also promoting skin wounds repair. Consequently, this research validated the possibility of leveraging microorganisms to bio-functionalize BC, conferring it with photocatalytic antibacterial properties. Furthermore, successfully modification of the microorganisms' glucose carbon source offers valuable insights into biosynthesis of other living materials through microbial metabolism.

Creating sustainable and flexible architectural skin with microbial cellulose-based material: synthesis and mechanical characterization

AbstractAttaining sustainability by developing efficient architectural materials will be a suitable remedy for various environmental problems. Incorporating clean biotechnology, particularly Bacterial Cellulose (BC), into the field of Architecture Design offers a novel strategy with the objective of creating environmentally-friendly architectural materials. The key goal of this research is to investigate the synthesis of BC by cultivating kombucha SCOBY in a culture medium that has been supplemented with sugar and tea extract. The linear density, tensile strength and strain of the BC bio-film and BC composites were assessed in order to determine the material’s degree of fitness in potential applications. The tensile test showed that BC bio-film and its jute composite had tensile strengths of 5 MPa and 10 MPa respectively, indicating notable resilience and durability as a feasible substitute for conventional construction materials. The study delves deeper into the sustainability, biodegradability, and economic feasibility of BC, emphasising its potential as an independent foundational material. The incorporation of jute fibres into BC enhances its capabilities, resulting in the development of a novel composite material known as BC + jute. This composite exhibits superior mechanical and psychochemical characteristics, making it suitable for the creation of sophisticated architectural prototypes. The results of this research establish a strong foundation for the advancement of ecologically conscious architectural solutions, demonstrating the feasibility and capacity of BC in promoting sustainability within the construction sector.Keywords: Microbial Cellulose, Scopy, Architecture, Environmental-friendly, sustainability, interior design, jute fiber, biomaterials.

Synthesis and Characterization of Antimicrobial Bacterial Cellulose Crosslinked with Branched Polyethylenimine

This study examines the development of composite bacterial cellulose (BC) sheets with antimicrobial properties for potential application in face masks. Branched polyethylenimine (PEI) is employed as the antimicrobial agent, effective against both gram-positive and gram-negative bacteria. Various concentrations of PEI are crosslinked into BC via epichlorohydrin under moderate conditions. The thermal and morphological properties of dried BC-PEI samples are comprehensively characterized. Results reveal that introducing PEI via crosslinking minimally impacts the thermal stability of BC, without any discernible physical disruption. Nevertheless, BC-PEI matrices present lower water evaporation enthalpies than BC, based on dynamic scanning calorimetry, caused by alteration of hydrogen bonding interactions (amine groups versus hydroxyl groups). Moreover, dried BC-PEI samples exhibit an improved efficacy against gram-positive bacteria as compared to gram-negative bacteria; S. aureus and P. aeruginosa, respectively. Indeed, a 2.5% (wt/v% of Milli-Q water) PEI concentration completely inhibits the growth of S. aureus after 6 h, while a 7.5% PEI concentration achieves similar effects on P. aeruginosa. Despite the notable antibacterial efficacy of BC-PEI matrices, their antiviral efficacy is less pronounced. This difference in antibacterial and antiviral efficacies could be attributed to variations in microorganism characteristics, mechanisms of action, and structures of PEI.

Synthesis of bacterial cellulose nanofibers/Ag nanoparticles: Structure, characterization and antibacterial activity

The aim of this study was to compare the characterization of bacterial cellulose nanofibers/Ag nanoparticles (BCNs/Ag nanoparticles) obtained by three different pretreatment methods of BCNs (no pretreatment, sodium hydroxide activation pretreatment and TEMPO-mediated oxidation pretreatment), which were recoded as N-BCNs/Ag nanoparticles, A-BCNs/Ag nanoparticles and O-BCNs/Ag nanoparticles, respectively. The results of scanning electron microscopy and transmission electron microscopy showed the prepared Ag nanoparticles by three different pretreatment methods were spherical and dispersed on the surface of BCNs, while the Ag nanoparticles in O-BCNs/Ag nanoparticles displayed the smallest diameter with a value of 20.25 nm and showed the most uniform dispersion on the surface of BCNs. The ICP-MS result showed O-BCNs/Ag nanoparticles had the highest content of Ag nanoparticles with a value of 2.98 wt%, followed by A-BCNs/Ag nanoparticles (1.53 wt%) and N-BCNs/Ag nanoparticles (0.84 wt%). The cytotoxicity assessment showed that the prepared BCNs/Ag nanoparticles were relatively safe. Furthermore, the O-BCNs/Ag nanoparticles had the best antioxidant and antibacterial activities as compared with the other two types of BCNs/Ag nanoparticles, where O-BCNs/Ag nanoparticles destroyed the structure of bacterial cell membranes to lead the leakage of intracellular components. This study showed that O-BCNs/Ag nanoparticles as antibacterial agents have great potential in food packaging.

Simultaneous Production of Cellulose Nitrates and Bacterial Cellulose from Lignocellulose of Energy Crop.

This study is focused on exploring the feasibility of simultaneously producing the two products, cellulose nitrates (CNs) and bacterial cellulose (BC), from Miscanthus × giganteus. The starting cellulose for them was isolated by successive treatments of the feedstock with HNO3 and NaOH solutions. The cellulose was subjected to enzymatic hydrolysis for 2, 8, and 24 h. The cellulose samples after the hydrolysis were distinct in structure from the starting sample (degree of polymerization (DP) 1770, degree of crystallinity (DC) 64%) and between each other (DP 1510-1760, DC 72-75%). The nitration showed that these samples and the starting cellulose could successfully be nitrated to furnish acetone-soluble CNs. Extending the hydrolysis time from 2 h to 24 h led to an enhanced yield of CNs from 116 to 131%, with the nitrogen content and the viscosity of the CN samples increasing from 11.35 to 11.83% and from 94 to 119 mPa·s, respectively. The SEM analysis demonstrated that CNs retained the fiber shape. The IR spectroscopy confirmed that the synthesized material was specifically CNs, as evidenced by the characteristic frequencies of 1657-1659, 1277, 832-833, 747, and 688-690 cm-1. Nutrient media derived from the hydrolyzates obtained in 8 h and 24 h were of good quality for the synthesis of BC, with yields of 11.1% and 9.6%, respectively. The BC samples had a reticulate structure made of interlaced microfibrils with 65 and 81 nm widths and DPs of 2100 and 2300, respectively. It is for the first time that such an approach for the simultaneous production of CNs and BC has been employed.

Symbiosis of acetic acid bacteria and yeast isolated from black tea fungus mimicking the kombucha environment in bacterial cellulose synthesis

The symbiotic effect of acetic acid bacteria and yeast on bacterial cellulose (BC) synthesis in kombucha was explored. Firstly, the optimal culture ratio of acetic acid bacteria and yeast was optimised through single factor and orthogonal test. The results showed that when Komagataeibacter intermedius:Brettanomyces bruxellensis:Zygosaccharomyces bisporus ratio was 1:10:10, and the inoculation amounts of K. intermedius, B. bruxellensis, and Z. bisporus were 104, 105, and 105 CFU/mL, respectively, the yield of BC was the highest, and the dry basis was 5.51 g/L. It was determined that the metabolites of B. bruxellensis and Z. bisporus could promote the synthesis of BC by K. intermedius. In addition, the composition of yeast filtrate was analysed by amino acid analyser, gas chromatography-mass spectrometry (GC-MS), and high performance liquid chromatograph (HPLC). Results showed that 16 amino acids were detected in yeast filtrate, and cysteine was only detected in yeast filtrate. The increase in isoleucine before and after fermentation was the highest, which was 11.64 times that of the control group. The increase in aspartic acid and glycine were second and third, accounting for 60.00 and 41.67%, respectively. The main volatile substances were alcohols, accounting for 84.89%, of which the relative content of ethanol was the highest at 77.35%. The relative contents of 3-methyl-1-butanol and phenylethanol were also high, accounting for 4.13 and 3.14%, respectively. Tartaric, citric, and succinic acids were detected in the yeast filtrate. The chemical species did not change before and after fermentation, but the content decreased. Vitamins B2 and B6 were detected in yeast filtrate, and the species and content did not change significantly before and after fermentation. A theoretical basis for kombucha fermentation and BC synthesis was provided.

Whole-Genome Analysis of Novacetimonas cocois and the Effects of Carbon Sources on Synthesis of Bacterial Cellulose

Novacetimonas cocois WE7 (formally named Komagataeibacter cocois WE7) is a strain isolated from contaminated coconut milk, capable of producing bacterial cellulose (BC). We sequenced its genome to investigate why WE7 cannot synthesize BC from glucose efficiently. It contains about 3.5 Mb and six plasmid DNAs. N. cocois WE7 contains two bcs operons (bacterial cellulose operon, bcs I and bcs II); the absence of bcs III operons may lead to reduced BC production. From genome predictions, glucose, sucrose, fructose, maltose, and glycerol can be utilized to generate BC, with WE7 unable to metabolize carbohydrate carbon sources through the Embden–Meyerhof–Parnas (EMP) pathway, but rather through the Hexose Monophosphate Pathway (HMP) and tricarboxylic acid (TCA) pathways. It has a complete gluconic acid production pathway, suggesting that BC yield might be very low when glucose, maltose, and trehalose are used as carbon sources. This study represents the first genome analysis of N. cocois. This information is crucial for understanding BC production and regulation mechanisms in N. cocois and lays a foundation for constructing engineered strains tailored for diverse BC application purposes.

Synthesis of Novel Bacterial Cellulose Based Silver-Metal Organic Frameworks (BC@Ag-MOF) as Antibacterial Wound Healing

Bacterial Cellulose (BC) is a polymer derived from the bacterium Komagataeibacter xylinus with great potential for biomedical applications due to its high biocompatibility and biodegradability. In addition, the polymer is naturally biosynthesized by bacteria as hydrogels which can be used as optimal substrates for wound healing. However, the drawback of BC is the absence of antibacterial properties. Nowadays, some infections become more prevalent and harder to treat because of antimicrobial resistance, therefore, it is necessary to develop a strategy for modifying BC as wound healing that provides protection against bacterial contamination. In this work, silver-based Metal Organic Frameworks (MOFs) were immobilized into Bacterial Cellulose (BC). MOFs are porous coordination materials consisting of metal ions and multidentate organic ligands that have the potential as a matrix for metal ions due to their ability to gradually release metal ions. The structure and morphology of BC@Ag-MOF were successfully confirmed by Fourier-Transform Infrared spectroscopy (FTIR) and Scanning Electron Microscope (SEM). Evidently, BC@Ag-MOF exhibited a higher silver content (63.19%) than BC@Ag without immobilization into MOF (48.46%). Therefore, it indicated that MOF has large pores for enhancing the capacity for silver ion absorption in BC. The modified BC has never been reported and achieved the highest antibacterial activity of 99.99% against Gram-negative bacteria Escherichia coli. Moreover, BC@Ag-MOF has a higher antibacterial efficiency of 97% compared to BC@Ag without matrix. This study expands the potential application of BC modification in the field of biological antibacterial. has never been reported and achieved the highest antibacterial activity of 99.99% against Gram-negative bacteria Escherichia coli. Moreover, BC@Ag-MOF has a higher antibacterial efficiency of 97% compared to BC@Ag without matrix. This study expands the potential application of BC modification in the field of biological antibacterial.

Bacterial Cellulose: An Ecological Alternative as A Biotextile

Bacterial cellulose has come forth as a novel nano-material with an extensive range of distinct properties, making it an excellent industrial alternative to conventional plant cellulose, as the world moves toward a sustainable and cleaner phase. Bacterial cellulose is a biomaterial that breaks down naturally in the environment and is produced by natural mechanism in bacterial cells. It has been considered as a substitute to traditional biomaterials in numerous sectors, namely, textile, pharmaceutical, food industry, biotechnology, for its features enabling to achieve sustainable development goals. The present focus is on looking at developing an inexpensive substrate for the synthesis of bacterial cellulose from industrial waste as its commercialization is restricted due to social, economic, and environmental considerations. Upcoming research in biotechnological area of biotextiles and biocomposites aims to integrate basic knowledge of textiles with biological sciences thereby facilitating production of goods which are commercially more viable and also less harmful to the environment. The review discusses the data regarding the use of bacterial cellulose and its production over the years, notably in the textile sector, with an emphasis on advancement of research to enable its extensive production and in various other areas like cosmetology, food industry, biomedical and paper industry. In addition, potential benefits of bacterial cellulose development addressing many of the global sustainable development goals along with suggestions for its scale-up have also been discussed.

Synthesis and Characterization of Composites-Based Bacterial Cellulose by Ex-Situ Method as Separator Battery

Many studies have been conducted and developed on cellulose-based battery separator materials, including bacterial cellulose, which has characteristics like plant cellulose. This research aims to synthesize BC/Al2O3 composite and analyze its potential as a battery separator. The synthesis of the composite with the ex-situ method is to immerse BC from tofu liquid waste (fermentation time variation of 6, 7, and 8 days) into Al2O3 suspension. The characterization results showed that the immersion of Al2O3 in BC can increase porosity, electrolyte absorption, and conductivity, indicating that the composite has the potential to be used as a battery separator.

Synthesis of bacterial cellulose by Komagataeibacter rhaeticus MSCL 1463 on whey.

Production costs of bacterial cellulose (BC) can be reduced using alternative fermentation media, e. g., various agricultural by-products including whey. This study focuses on whey as an alternative growth medium for BC production by Komagataeibacter rhaeticus MSCL 1463. It was shown that the highest BC production on whey was 1.95 ± 0.15g/L, which is approximately 40-50% lower that BC production on standard HS media with glucose. It was also confirmed that K.rhaeticus MSCL 1463 can utilise both lactose and galactose as the sole C source in the modified HS medium. Different whey pre-treatment methods showed that the highest BC synthesis with K.rhaeticus MSCL 1463 was achieved in undiluted whey after standard pre-treatment procedure. Moreover, BC yield from substrate on whey was significantly higher (34.33 ± 1.21%) compared to the HS medium (16.56 ± 0.64%), which shows that whey can be used as a potential fermentation medium for BC production.

Cost-Effective Synthesis of Bacterial Cellulose and Its Applications in the Food and Environmental Sectors.

Bacterial cellulose (BC), also termed bio-cellulose, has been recognized as a biomaterial of vital importance, thanks to its impressive structural features, diverse synthesis routes, high thermomechanical properties, and its ability to combine with multiple additives to form composites for a wide range of applications in diversified areas. Its purity, nontoxicity, and better physico-mechanical features than plant cellulose (PC) make it a better choice for biological applications. However, a major issue with the use of BC instead of PC for various applications is its high production costs, mainly caused by the use of expensive components in the chemically defined media, such as Hestrin–Schramm (HS) medium. Furthermore, the low yield of BC-producing bacteria indirectly accounts for the high cost of BC-based products. Over the last couple of decades, extensive efforts have been devoted to the exploration of low-cost carbon sources for BC production, besides identifying efficient bacterial strains as well as developing engineered strains, developing advanced reactors, and optimizing the culturing conditions for the high yield and productivity of BC, with the aim to minimize its production cost. Considering the applications, BC has attracted attention in highly diversified areas, such as medical, pharmaceutics, textile, cosmetics, food, environmental, and industrial sectors. This review is focused on overviewing the cost-effective synthesis routes for BC production, along with its noteworthy applications in the food and environmental sectors. We have made a comprehensive review of recent papers regarding the cost-effective production and applications of BC in the food and environmental sectors. This review provides the basic knowledge and understanding for cost-effective and scaleup of BC production by discussing the techno-economic analysis of BC production, BC market, and commercialization of BC products. It explores BC applications as food additives as its functionalization to minimize different environmental hazards, such as air contaminants and water pollutants.

Growing Bacterial Cellulose-Based Sustainable Functional Bulk Nanocomposites by Biosynthesis: Recent Advances and Perspectives

ConspectusIn recent years, with the continuous development of nanomaterials and composite preparation methods, nanocomposites are playing an increasingly important role as structural materials or functional materials due to their outstanding properties. As an important part of nanocomposites, polymer-based nanocomposites have attracted the interest of researchers, whose preparation methods have been significantly expanded with the rapid development of polymer chemistry and physics. At present, nanomaterials can be combined with the polymer matrix to form various nanocomposite materials in multiple ways, ranging from simple blending to complex processes combining surface modification and in situ polymerization. However, these polymer-based nanocomposites are still limited by their incompatibility of structural strength and functionality and unsustainability of the preparation processes.As a new type of polymer-based materials, the polymers synthesized by microorganisms, especially bacterial cellulose (BC) produced by bacteria such as Gluconacetobacter xylinus, have great potential to overcome the above-mentioned problems. On the one hand, BC has a fine nanoscale three-dimensional (3D) network with extremely high strength. The continuous nanoscale 3D network means that the nanomaterials composited with BC can be interspersed in a 3D network, effectively exerting their functionality without compromising the strength of the composites. On the other hand, the process of microbial production of BC is completed under normal pressure and temperature without using toxic reagents and solvents, which gives it a huge advantage in terms of sustainability over traditional polymer synthesis. Unfortunately, the high-density 3D nanoscale network of BC is too tight to allow the entry of nanomaterials in a homogeneous way, which brings great difficulties to the composite process of BC and nanomaterials.Challenging this problem, a new in situ composite preparation strategy called aerosol-assisted biosynthesis (AABS) strategy has been proposed as a solution. This strategy cleverly combines the deposition of nanomaterial-contained aerosol and microbial synthesis of BC, leading to uniform dispersion of various nanomaterials in the BC network and the formation of nanocomposites. In this Account, we review the development history of composite preparation methods and discuss its trend from the perspective of matching of its critical factors in dimensions of space and time. From the view of the spatiotemporal overlap of the factors, we analyze how this AABS strategy combines the BC synthesis process and the composite formation in the dimensions of space and time, resulting in the universality, tunability, designability, scalability, sustainability, and other advantages of the AABS strategy. Furthermore, we look forward to the future where AABS-based composite preparation systems can be combined with artificial intelligence and automation systems to realize fully automatic and sustainable biointelligent fabrication.

Acetylation of Bacterial Cellulose from a Mixture of Palm Flour Liquid Waste and Coconut Water: The Effect of Acetylation Time on Yield and Identification of Cellulose Acetate

Cellulose acetate is a promising thermoplastic polymer to be developed since it has some characteristics, among others are easy to be formed, non-toxic, high stability, and its raw materials are renewable. The most used source of cellulose acetate raw material is bacterial cellulose because bacterial cellulose has the higher purity and the process cost is lower rather than plant cellulose. Nowadays, the production of bacterial cellulose is highly developed using coconut water media. Nevertheless, coconut water costs expensive and the supply is rare. Materials that are being potential to be developed as raw materials of bacterial cellulose through fermentation process is palm flour liquid wasted since it contains high amounts of carbon and nitrogen. This study began with the synthesis of bacterial cellulose from palm flour oil liquid waste and coconut water using Acetobacter xylinum bacteria and then cellulose acetate is synthesized through an acetylation reaction. This study aims to determine the optimum acetylation time on its performance as a reinforcement filler to be applied as a packaging material. Based on the results of Scanning Electron Microscopy and Fourier Transform Infra-Red analysis on predetermined variables, it resulted particles in the form of bacterial cellulose and cellulose acetate with the highest yield of cellulose acetate at 3 hours of acetylation was 94.74%.

Efficient fabrication, antibacterial and catalytic performance of Ag-NiO loaded bacterial cellulose paper

This study reports the synthesis of bacterial cellulose (BC) hydrogel sheets and their utilization as a support for silver‑nickel oxide nanocomposites (Ag/NiO). A two-step facile hydrothermal method was employed for the preparation of Ag/NiO, followed by impregnation into BC hydrogel sheets. A 20% Ag/NiO composition was revealed by dry weight analysis. The stability of nanocomposites-Hydrogel was confirmed by Ag+ and Ni2+ ion release study. The catalytic activity of the BC-Ag/NiO was evaluated against chemical reduction of congo red, methyl orange and methylene blue. The reduction reaction followed pseudo first order kinetics and kapp values of 0.1147 min−1, 0.1323 min−1 and 0.12989 min−1 were obtained for CR, MO, and MB dyes, respectively. The BC-Ag/NiO catalyst could be easily recovered and re-used in another reaction without centrifugation. The synthesized nanocomposites hydrogel was also tested for its antibacterial activity against Gram-negative bacteria, Escherichia coli (E.coli) and Gram-positive bacteria, Staphylococcus aureus (S.aureus).

Biochemistry, Synthesis, and Applications of Bacterial Cellulose: A Review.

The potential of cellulose nanocomposites in the new-generation super-performing nanomaterials is huge, primarily in medical and environment sectors, and secondarily in food, paper, and cosmetic sectors. Despite substantial illumination on the molecular aspects of cellulose synthesis, various process features, namely, cellular export of the nascent polysaccharide chain and arrangement of cellulose fibrils into a quasi-crystalline configuration, remain obscure. To unleash its full potential, current knowledge on nanocellulose dispersion and disintegration of the fibrillar network and the organic/polymer chemistry needs expansion. Bacterial cellulose biosynthesis mechanism for scaled-up production, namely, the kinetics, pathogenicity, production cost, and product quality/consistency remain poorly understood. The bottom-up bacterial cellulose synthesis approach makes it an interesting area for still wider and promising high-end applications, primarily due to the nanosynthesis mechanism involved and the purity of the cellulose. This study attempts to identify the knowledge gap and potential wider applications of bacterial cellulose and bacterial nanocellulose. This review also highlights the manufacture of bacterial cellulose through low-cost substrates, that is, mainly waste from brewing, agriculture, food, and sugar industries as well as textile, lignocellulosic biorefineries, and pulp mills.

Direct Synthesis of Photosensitizable Bacterial Cellulose as Engineered Living Material for Skin Wound Repair.

Living materials based on bacterial cellulose (BC) represent a natural and promising candidate for wound dressing. Both physical adsorption and chemical methods have been applied to BC for realizing antibacterial function. However, effective and long-lasting incorporation of bactericidal moieties to BC remains challenging. Herein, a Komagataeibacter sucrofermentans-based direct synthetic method to fabricate photosensitizer-grafted BC throughin situbacterial metabolism in the presence of TPEPy-modified glucose is explored. The results verify that the direct biosynthesis method is efficient and convenient to endow BC with outstanding fluorescence and light-triggered photodynamic bactericidal activity for skin wound repair. This work presents a new approach to fabricate eco-friendly and active wound dressing with light-controlled bactericidal activity by microbial metabolism. The successful modification of the glucose carbon source of microorganisms also offers insights for biosyntheses of other living materials through microbial metabolism.

Sustainable Production of Stiff and Crystalline Bacterial Cellulose from Orange Peel Extract

In this work, a potentially economic and environmentally friendly method for the synthesis of bacterial cellulose (BC) by Gluconacetobacter xylinus from a biomass containing orange peel extract was evaluated. Orange peel extract was used as a culture medium without any hydrolysis treatment, thus speeding up the synthesis procedure. The efficacy of orange peel as a carbon source was compared with that of sucrose. The orange peel extract formed thicker cellulose gels than those formed using sucrose. X-ray diffraction (XRD) revealed both a high crystallinity index and crystallite size of BC nanofibers in samples obtained from orange peel (BC_Orange). Field emission scanning electron microscopy (FE-SEM) revealed a highly densely packed nanofibrous structure (50 nm in diameter). BC_Orange presented a two-fold increase in water holding capacity (WHC), and dynamic mechanical analysis (DMA) showed a 44% increase in storage modulus compared to sucrose derived BC. These results showed that the naturally available carbon sources derived from orange peel extract can be effectively used for BC production. The orange-based culture medium can be considered a profitable alternative to the generation of high-value products in a virtuous circular economy model.

Bacterial Cellulose (BC) and BC Composites: Production and Properties.

The synthesis of bacterial cellulose (BC) by Komagataeibacter xylinus strain B-12068 was investigated on various C-substrates, under submerged conditions with stirring and in static surface cultures. We implemented the synthesis of BC on glycerol, glucose, beet molasses, sprat oil, and a mixture of glucose with sunflower oil. The most productive process was obtained during the production of inoculum in submerged culture and subsequent growth of large BC films (up to 0.2 m2 and more) in a static surface culture. The highest productivity of the BC synthesis process was obtained with the growth of bacteria on molasses and glycerol, 1.20 and 1.45 g/L per day, respectively. We obtained BC composites with silver nanoparticles (BC/AgNPs) and antibacterial drugs (chlorhexidine, baneocin, cefotaxime, and doripenem), and investigated the structure, physicochemical, and mechanical properties of composites. The disc-diffusion method showed pronounced antibacterial activity of BC composites against E. coli ATCC 25922 and S. aureus ATCC 25923.

Nitric acid solution after treating miscanthus as a growth regulator of seed peas (Pisum sativum L.)

Abstract: All over the world, miscanthus is positioned as an extremely promising and rapidly renewable cellulose- containing raw material for the production of a large number of substances of chemical and biotechnological synthesis. The Institute for Problems of Chemical and Energetic Technologies of the Siberian Branch оf the Russian Academy of Sciences has been developing its own methods of treating miscanthus using diluted solutions of nitric acid. While the amount of a waste solution (liquid phase) is 20 times greater than the target product — a solid phase -- intended for enzymatic hydrolysis and further microbiological synthesis of bioethanol, bacterial cellulose and other valuable products. The hypothesis states that a nitric acid solution after treatment with miscanthus, which was neutralized with ammonium hydrate (hereinafter referred to as the preparation), is a combined lignohumic fertilizer. Testing this hypothesis has required studying the growth-regulating activity of the preparation using the example of sowing pea seeds. The results show that, depending on the degree of dilution and the exposure time, the preparation acts in two ways: either as a stimulant or as a growth inhibitor. Thus, at a dilution rate of 1:10, the preparation acts as an inhibitor, and at a dilution rate of 1:1,000,000, its effect ceases. The working range includes the dilution rate between 1:100 and 1:10,000, when an increase in germination energy and rate is observed by 2–6% compared to the control and root growth is stimulated by 21–29%, i.e. an auxin-like growth-stimulating effect is observed. With prolonged endurance during the 4th day, the preparation showed a growth-inhibiting effect, indicated by the decrease in the germination energy and rate, the length of the stems and roots of the sowing pea. The new preparation showing growth-stimulating activity under certain conditions, supposedly confirms the hypothesis that it is a combined lignohumic fertilizer.