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The aim of this study was to formulate bio-cellulose film incorporating Punica granatum (pomegranate) peel extract for application as anti-acne product. The dried pomegranate peels were extracted by water (PPEwater), 50% (PPE50E), 70% (PPE70E) or 95% (PPE95E) (v/v) ethanol. The extracts were total phenolic content (TPC) and free radical scavenging activity. PPE50E had highest TPC (55.95±1.44 gGAE/100g of dried peel extract), highest free radical scavenging activity with IC50 of 18.77±1.73 µg/ml and exerted the activity of bactericidal against Staphylococcus aureus, Staphylococcus epidermidis and Propionibacterium acne (P. acne). The PPE50E was selected for formulating anti-acne bio-cellulose (BC) film. The BC film prepared from bacteria Acetobacter xylinum. It showed a strong film with the tensile strength in range of 5 - 15 MPa and the elongation at break about 5%. The simple soaking method was used to combine BC with 5 or 10 mg/ml of PPE50E. By the SEM, the assemble nanofibrils and the layer structure of the BC combining with the PPE50E (BCP) was found. The BCP had higher tensile strength and lower elongation at break than the BC. The BCP at wet state showed a soft and flexible film. The anti-bacterial efficacy of the BCP against tested bacteria was observed, according to the disc diffusion assay. The P. acne inhibition zones of the BCP at the concentration of 5 and 10 mg/ml were 27.7 and 35.5 mm which closed to the clindamycin (45.5 mm) as positive control. From the remarkable results, the BCP is interestingly natural device for acne treatment. [ABSTRACT FROM AUTHOR]

The recent study aimed to isolates Acetobacter xylinum from local home vinegar samples processed of apple, dates and grape. From the total fifty; Twenty-one isolates observed on the surface of HS-agar medium, only four isolates showed transparent zone around the colony on GYC agar plates. The isolates (B1, B2, B3 and B4) were examined for bacterial cellulose production in HS broth medium. The dry weight of crude cellulose produced by each isolates was measured and ranged from 0.36 - 0.42 gm. The pH value of bacterial cellulose were (6.2 - 6.9), approximately equal and nearly to the neutral values with comparison with plant cellulose. The thickness of bacterial cellulose membrane is a key parameter in preparing film, the initial thickness of the wet BC membrane was measured as 32 micrometers and after drying the computed thickness of BC membrane decreased to 0.4 micrometers. The average tensile strength value and the average elongation at break value of the dried BC films were 34.5 MPa and 5.2% respectively. The micrograph of BC shows three dimensional porous network structure formed by ribbon fibrils, randomness of fiber distribution without any specific orientation. The SEM micrograph obtained for the purified Bacterial Cellulose (BC) shown a very similar structure with the commercial Plant Cellulose (PC). Furthermore, the fibrils were densely packed ; the aggregated BC showed flat and were smoother surface compared to the PC. X-ray diffraction analysis is used to study the physical properties of both BC and PC samples such as morphology, the degree of crystallinity, crystal size and to categorize cellulose as type Ior I. 2 range 5o to 40o is usually adequate to cover the most important area of the XRD pattern. The pattern for BC revealed four main peaks were at 2 = 14.53, 16.78, 22.79 and 34.67, corresponding to the crystallographic peak plane of (110), (110) (200) and (004), respectively. The X-ray diffractograms of purified BC sample showed their amorphous nature. The distinguishing broad peaks at 3452.58 cm-1 for BC and 3356.14 cm-1 for PC indicates OH is stretching intra molecular H-bond for cellulose1. Sharp peaks appeared CH stretching at 2924.09 cm-1 in BC and 2900.94 cm- 1 in The pattern for BC revealed four main peaks were at 2 = 14.53, 16.78, 22.79 and 34.67, corresponding to the crystallographic peak plane of (110), (110) (200) and (004), respectively. The X-ray diffracts grams of purified BC sample showed their amorphous nature. The FTIR spectrum shown the distinguishing broad peaks at 3452.58 cm-1 for BC and 3356.14 cm-1 for PC indicate OH is stretching intermolecular H-bond for cellulose 1. Sharp peaks appeared CH stretching at 2924.09 cm-1 in BC and 2900.94 cm-1 in PC. Overall, these data suggested that the BC and PC samples were the typical profile of the cellulose I crystalline structure and is typical of cellulose isolated from other fiber sources. The present results proved that BC and PC have a similar chemical bond and functional groups. [ABSTRACT FROM AUTHOR]

• A novel porogen was used for constructing porous bacterial cellulose. • The size of Ca-alginate microparticles was flexibly variable through electrostatic spinning and pulverization. • The porous bacterial cellulose exhibited a well uniform and spherical macropore cellulose network. In an attempt to obtain bacterial cellulose (BC) with controllable pores, Ca-alginate particles were introduced into BC fermentation medium. Ca-alginate particles with different diameters were prepared through electrostatic spinning and pulverization. After removing the particles, a continuous and homogeneous network of pores with diameters around 5 μm, 20 μm, and 400 μm were presented inside BC hydrogel. Compared to native BC, the crystallinity, the surface area and water holding capacity (WHC) were all increased when the pore sizes around 5 μm, 20 μm. However, the porous BC with diameters around 400 μm showed poor performance in WHC and mechanical strength. This novel approach described in this paper introduced a new approach for creating controllable porous BC with user-defined control over the physical dimensions of the network, and slightly changed its structure. [ABSTRACT FROM AUTHOR]

We discuss microbial cellulose (MC) produced by Acetobacter Xylinum and its metabolism related to the bacterium body structure on a basis of knowledges obtained by the small-angle scattering method with combining different spectrometers. MC is a supra-molecule system impregnated with a huge amount of water about 99% by weigh. In the previous literature [ Eur. Phys. J. E , 2008 and Macromol. Symp. 2009], we elucidated that 90% of total water is accumulated in non-crystalline bundle causing concentration fluctuations. In this paper, we develop our arguments by newly adding the knowledges on (i) the hierarchy in a bacterium body studied by SANS & USANS and (ii) the non-crystalline local structure in as-produced MC in a culture solution, confirmed by neutron diffraction with polarization analyses. As a control to emphasize the peculiarity of MC, we compare MC to a synthetic polymer gel of poly(N -isopropylacrylamide) (PNIPAAm) in a swollen state. Consequently, we conclude that a mechanism of excellent water absorption found for MC is attributed to capillarity related to hierarchically preserved non-crystalline domains, whereas tight hydration onto a monomer unit via a hydrogen bond is crucial to result in high water absorption for the PNIPAAm gel. Image 1 • In the previous literatures [ Eur. Phys. J. E , 2008 and Macromol. Symp. 2009], we elucidated that 90% of total water is accumulated in non-crystalline bundle in microbial cellulose (MC) produced by Acetobacter Xylinum. • In this paper, we developed our arguments by newly adding the knowledges on (i) the hierarchy in a bacterium body studied by SANS & USANS and (ii) the non-crystalline local structure in as-produced MC in a culture solution, confirmed by neutron diffraction with polarization analyses. • As a control, we studied a synthetic polymer gel of poly(N -isopropylacrylamide) (PNIPAAm) in a swollen state. • A mechanism of excellent water absorption of MC is attributed to capillarity related to hierarchically preserved non-crystalline domains, whereas tight hydration onto a monomer unit via a hydrogen bond is crucial for high water absorption for the PNIPAAm gel. [ABSTRACT FROM AUTHOR]

In this study, effective microorganism (EM) was added into fermentation medium in static culture to enhance bacterial cellulose (BC) production by Acetobacter xylinum 23769 strain. According to SEM micrographs, BC pellicles from BC-Baikal EM1 show a smaller diameter and a relatively narrow diameter distribution compared to BC pellicles from Hestrin–Schramm (HS) medium. The BC-HS absorbed 90.5 times its dry weight of water. The water holding capacity increased to 132.5 for BC-Baikal EM1 medium compared to BC-HS. From the FT-IR spectra, BC samples exhibited a similar pattern. The crystalline indices of Baikal EM1-altered BC (66%) were lower than Baikal EM1-free BC (71%). [ABSTRACT FROM AUTHOR]

The aim of this study was to assess whether modified bacterial cellulose can be used for an artificial auricle skeleton. Introduction: The auricle is a part of the external ear. It consists of skin, cartilage, muscles and adipose tissue. The cartilage gives shape to the structure. There are several indications for reconstruction, such as congenital anomalies, mechanical injuries and burns, and a range of methods have been proposed for complete reconstruction of the auricle. Material and methods: A bacterial cellulose membrane, at least 25 mm in thickness, was produced in vitro by Acetobacter xylinum culture. The entire artificial human auricle skeleton was made to scale to allow its implantation into an animal model - Wistar rats. Forty rats were divided into four groups of 10 animals. Each group was assigned a different resection time: 14 days, 30 days, 90 days or 720 days. After each resection, an examination of the artificial skeleton and the tissues surrounding it was conducted. The surgical procedure was based on the Nagata technique. Results: Resection after 14, 30, 90 and 720 days shows progression of the healing process and integration of the artificial skeleton into the animal body. There are no signs of change in the shape or structure of the skeleton. Discussion: Several surgical techniques and biotechnological methods have been developed over the past few years to improve the results of facial reconstruction. Other approaches can be used to create auricle cartilage, based on scaffolds and chondrocytes. Conclusion: My findings indicate that modified bacterial cellulose can be used to form an effective artificial auricle which appears to maintain its shape and elasticity, with no signs of degradation. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Acetobacter xylinum synthesized BC using tobacco waste extract. • Nicotine was found to be inhibitory for the synthesis of BC. • BC production increased after nicotine removal by steam distillation at pH 9.0. • BC production reached 5.2 g/L using two-stage fermentation by adjusting pH. • BC obtained from TWE medium has similar properties to that from HS medium. Abstract In this study, bacterial cellulose (BC) was synthesized by Acetobacter xylinum ATCC 23767 using tobacco waste extract (TWE) as a carbon source. Nicotine was found to be an inhibitory factor for BC synthesis, but it can be removed at pH 9.0 by steam distillation. After removing nicotine, the BC production was 2.27 g/L in TWE prepared with solid-liquid (S-L) ratio at 1:10. To further enhance the BC production, two fermentation stages were performed over 16 days by re-adjusting the pH to 6.5 at 7 days, after the first fermentation stage was completed. Using this two-stage fermentation, the BC production could reach 5.2 g/L. Structural and thermal analysis by FE-SEM, FT-IR, XRD and TGA showed the properties of BC obtained from TWE were similar to that from Hestrin-Schramm (HS) medium. Considering the huge disposal tobacco waste in China, the present study provides an alternative methodology to synthesize BC. [ABSTRACT FROM AUTHOR]

This paper focuses on treated date seed with two cellulolytic bacteria (Acetobacter xylinum and Thermonospora fusca) isolated from sheep and evaluated these species by Invitro gas production and metabolism trail. We evaluated the influence of many rations contain several percentage from date seed untreated and treated on In vitro traild for DM,OM, NDF, ADF, cellulose and hemicellulose disappeara (samples incubated for 24 hrs). the best ration used in metabolism trail . The experimental work was conducted in 2017, at the Department of Animal Production, faculty of agriculture, Ain Shams University, Cairo, Egypt and the experiment of the farm animals occurred in the Animal Production research institute. Our results in this revealed that the ration content 25% untreated and treated with bacteria had significant values on NDF, ADF and hemicellulose degradability after 24 hours, especially treatment 2 (Thermonospora fusca) of date seed. In the experimental ration with ascending level of untreated and treated date seed had not significant effect on pH value while more effect on total gas production (GP),ammonia, TVFA’s, MP, EMP and metabolizable energy ME (Mcal/ g). The differences were significant (P<0.05) between control ration and other experimental rations. Furthermore, ration content date seed treated (R3) had the highest values of DM, OM, CF and EE digestibility. It could be noticed that improving CP, CF and cell wall constituents (NDF, ADF, hemicellulose and cellulose) digestibility may be due to the increasing number of rumen cellulolytic bacteria. In conclusion, the bacterial treatment (Acetobacter xylinum and Thermonospora fusca) with date seed successfully to improve chemical compostion of date seed and Invitro digestiability specially ration contain 25% from total dry matter. It showed that the strain (Thermonospora fusca) was the best in In vitro fermentation . Digestibility indicated that ration contain treated date seed (R3) was high DM, OM, ADF and nitrogen than other rations. It was concluded that treated date seed can replace concentrate in rations and improve In vitro degradability, digestibility trail and no effect on rumen and blood parameters without adversely affecting on helthy animals. [ABSTRACT FROM AUTHOR]

Introduction: There is an increasing need for vascular prosthesis in dialysis medicine for the construction of arteriovenous (AV)-fistulas for dialysis access. The aims of this study were; a) to develop and validate a new experimental AV-fistula model for larger animals using grafts of bacterial cellulose (BC) between the common carotid artery and the external jugular vein; b) to observe the immediate and intermediate properties (macroscopic and angiographic patency and the macro- and micro thrombogenicity) of the grafts. Materials and Methods: As graftmaterial bacterial cellulose was used, produced around a preformed scaffold. Bacterial cellulose (BC) is a material produced by the bacteria acetobacter xylinum. A pilotstudy was conducted on 6 pigs to validate the animalmodel and the new graftmaterial. In the following survival study a BC-graft AV-fistula was constructed in 15 pigs. Results: In the pilot study, 5 out of 6 animals had a patent AV-fistula 4 hours after implantation. In the survival study, after 4 (n3) and 8 (n10) weeks an angiography was performed prior to explantation of the BC-graft. All grafts were occluded with a presumed platelet plug. We conducted an additional acute patch-test comparing the BC and expanded PolyTetraFluoro- Ethylene. A patch of BC and ePTFE was applied to the right and left common femoral artery respectively. At explantation three hours later, all BC-patches showed a thin gel like layer, most likely consisting of platelets, throughout the whole sur- face while the ePTFE-patch showed no, or minimal, signs of platelet adhesions. Conclusion: Theoretically the cellulose might be similar to autologous veins considering risk of infections and thrombo- genicity. The animal model and the graft material showed good potential in the pilot study. The survival study was discour- aging with the reason for occlusion still to be explained. Bacterial cellulose has a good potential but further development and studies need to be performed. [Arch Clin Exp Surg 2016; 5(2.000): 70-77]

Dusun Tegal Domban is one of the highest Salak Pondoh produce in Sleman District. However there is a problemfaced by salak farmers due to the overproduction and overripe which mightcause waste. Implementation of Biotechnology should be one of the alternativesolutions to overcome this problem. The aims of the program were to utilize the salak fruits wasteto produce Natade Salaccausing biological agents, such as Acetobacter xylinum, and to implement the education for sustainability development which subjected toa women organization PKK Dusun Tegal Domban who accompanyed by the team from Biotechnology Master Program UGM in order to learn how to produce Nata de Salacca. This program was initiated with the laboratory experiments to find the fine composotion of nata substrates to get the optimal nata product. The following action was to acompany the women who aplicate the nata production process. Results from the laboratory experiment showed that the best composition of substrat and water ratiowas 1:4, and the nata thickness was 0.62 cm, while the nata weight was 542.22 g. Those parameters were used for nata standard indicators.Results from the activities of nata production by women groups PKK Dusun Tegal Domban were showed the similar results with the nata standard for thickness, however nata weight was slightly lower than the nata standard.

Acetobacter xylinum adalah bakteri yang digunakan pada produksi selulosa bakteri, namun produktivitasnya masih rendah. Salah satu upaya untuk meningkatkan produktivitasnya adalah dengan melakukan strain improvement menggunakan Ethyl Methane Sulfonate (EMS). Tujuan dari penelitian ini adalah untuk mengetahui lama waktu kontak EMS optimum yang mampu menghasilkan Acetobacter xylinum mutan dan mengetahui peningkatan selulosa yang dihasilkan. Penelitian ini menggunakan metode deskriptif-kuantitatif dengan perlakuan EMS 5μl/ml dan lama waktu kontak 1, 2, 3, 4, 5 jam. Isolat mutan yang didapat diuji kemampuan produksi selulosanya dan dibandingkan dengan wildtype. Hasil penelitian menunjukkan bahwa perlakuan mutagenesis EMS 5μl/ml pada Acetobacter xylinum selama 5 jam menghasilkan rasio kematian sebesar 91.75% dan menghasilkan 8 isolat mutan. Isolat mutan M6 menghasilkan rendemen selulosa 67.19%, nilai ini 36.54% lebih tinggi dibandingkan wildtype. Hasil tersebut mengindikasikan bahwa penggunaan mutagenesis dengan EMS dapat dilakukan untuk meningkatkan kemampuan produksi selulosa dari Acetobacter xylinum.

Abstract: Cellulose nanofibrils are attractive as building blocks for advanced photonic, optoelectronic, microfluidic, and bio‐based devices ranging from transistors and solar cells to fluidic and biocompatible injectable devices. For the first time, an ultrastrong and ultratough cellulose film, which is composed of densely packed bacterial cellulose (BC) nanofibrils with hierarchical fibril alignments, is successfully demonstrated. The molecular level alignment stems from the intrinsic parallel orientation of crystalline cellulose molecules produced by Acetobacter xylinum. These aligned long‐chain cellulose molecules form subfibrils with a diameter of 2–4 nm, which are further aligned to form nanofibril bundles. The BC film yields a record‐high tensile strength (≈1.0 GPa) and toughness (≈25 MJ m−3). Being ultrastrong and ultratough, yet the BC film is also highly flexible and can be folded into desirable shapes. The BC film exhibits a controllable manner of alignment and is highly transparent with modulated optical properties, paving the way to enabling new functionalities in mechanical, electrical, fluidic, photonics, and biocompatible applications. [ABSTRACT FROM AUTHOR]

Abstract: To improve bacterial cellulose (BC) applications, researchers have expanded their efforts with BC productivity and its properties. The objectives of this study are to evaluate the possibility and efficacy of using extracted date syrup as a carbon source for Acetobacter xylinum 0416 in BC production in a static culture. The sugar content of extracted date syrup was identified by HPLC. Different concentrations of dates and different culturing times were tested. The produced BCs were characterized and their respective properties were compared with a BC produced from Hestrin and Schramm (HS) medium. The most effective BC amount was attained with 3% (w/v) date in the medium on day 8. The modified HS medium (DHS) increased production by 68% (P < 0.05). Morphological analysis by scanning electron microscopy revealed more disorganized arrangements in BC fiber obtained from DHS medium (BC‐DHS) than that from HS medium (BC‐HS). Thermogravimetric analysis revealed no significant changes in BC‐DHS thermostability compared to BC‐HS. However, the crystallinity of BC‐DHS improved (P < 0.05). The results of Fourier transform infrared spectroscopy demonstrated that the carbonyl group in BC‐DHS is more active than that of BC‐HS. Furthermore, the properties of BC‐DHS showed excellent potential for use in many applications. [ABSTRACT FROM AUTHOR]

Durian is one important tropical fruit with high nutritional value, but its shell is usually useless and considered as waste. To explore the efficient and high-value utilization of this agricultural and food waste, in this study, durian shell was simply hydrolyzed by dilute sulfuric acid, and the durian shell hydrolysate after detoxification was used for bacterial cellulose (BC) production by Gluconacetobacter xylinus for the first time. BC was synthesized in static culture for 10 days and the highest BC yield (2.67 g/L) was obtained at the 8th day. The typical carbon sources in the substrate including glucose, xylose, formic acid, acetic acid, etc. can be utilized by G. xylinus. The highest chemical oxygen demand (COD) removal (16.40%) was obtained at the 8th day. The highest BC yield on COD consumption and the highest BC yield on sugar consumption were 93.51% and 22.98% (w/w), respectively, suggesting this is one efficient bioconversion for BC production. Durian shell hydrolysate showed small influence on the BC structure by comparison with the structure of BC generated in traditional Hestrin-Schramm medium detected by FE-SEM, FTIR, and XRD. Overall, this technology can both solve the issue of waste durian shell and produce valuable bio-polymer (BC). [ABSTRACT FROM AUTHOR]

The gram-negative bacterium of Gluconacetobacter xylinum is widely used to produce high-quality cellulose in the form of complex strips in microfiber bundles on a commercial scale. In this study, the film-forming potential of bacterial cellulose in combination with polyvinyl alcohol (PVA, 5 % w / v) and Barhang seed gum (BSG, 0.5 % w/v) loaded with summer savory (Satureja hortensis L.) essential oil (SSEO) to prepare a new wound dressing was investigated. The X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FTIR), field emission-scanning electron microscopy (FE-SEM), and thermogravimetric analysis (TGA), and Brunauer-Emmett-Teller (BET) surface area, in-vitro antibacterial, and in-vivo wound healing activities were performed to assess the structure, morphology, stability, and bioactivity of biocomposite films. Results showed that the SSEO incorporation into the polymeric matrix yielded smooth and transparent composite film with excellent thermal resistance. A significantly robust antibacterial activity against gram-negative bacteria by the bio-film was found. The healing process on mice models revealed that the SSEO-loaded composite film had a promising potential for wound healing associated with improved collagen deposition and reduced inflammatory response. [ABSTRACT FROM AUTHOR]

[Display omitted] • Multifunctional BCN-based three-phase O/W CA-εPL PEs were constructed. • CA-εPL PEs into the structures of gelatin matrix to prepare GL-CA-εPL PE films. • GL-CA-εPL PE films showed excellent antioxidant, antibacterial properties, etc. • Cheese were packed in the GL-CA-εPL100 PE film extended shelf life. • GC-IMS showed samples no significant differences between packed film and unpacked. Owing to increasing plastic pollution and concerns about food safety, extensive research attention has been paid to biodegradable active packaging. Herein, we developed bacterial cellulose nanocrystal (BCN)-based three-phase Pickering nanoemulsion gelatin (GL) films. In detail, bacterial cellulose was obtained using Acetobacter xylinum , which was then hydrolyzed using sulfuric acid to prepare BCNs. Carnosic acid (CA) and ε-polylysine (εPL) were incorporated into the BCN matrix through electrostatic complexation and the matrix was ultrasonically triggered as an emulsification self-assembly strategy, forming the multifunctional BCN-based three-phase O/W Pickering nanoemulsions (CA-εPL PEs). Furthermore, a novel active packaging film (GL-CA-εPL PEs) was designed via intermolecular hydrogen bonding and dehydration condensation by introducing CA-εPL PEs into the 3D network structures of a GL matrix; both phases showed good interaction and compatibility, along with excellent antioxidant, antibacterial, UV-shielding, good mechanical, heat-sealing, sustainable release, and biodegradable properties. Additionally, fresh (acid-coagulated) and mozzarella cheese were packed in the GL-CA-εPL100 PE film, and their shelf life was extended due to delayed lipid peroxidation and inhibition of the growth of spoilage microorganisms. Sensorial and flavored (GC-IMS) analyses showed no significant differences between the samples packed in the GL-CA-εPL100 PE active film and the unpacked samples. This study provides scientific insights for designing BCN-based O/W multifunctional three-phase Pickering nanoemulsion delivery systems for active food packaging; the proposed method can be promising for reducing the environmental impact of plastic pollution. [ABSTRACT FROM AUTHOR]

Bacterial cellulose (BC) is a polysaccharide with tubular structure and can be produced by various species of bacteria particularly Acetobacter xylinum. It is a promising matrix for fabricating electrochemical devices as a mechanically strong, flexible, and biocompatible carbon-based material. In the present work, BC and graphene oxide (GO) composite was obtained simply via a mixing method. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images showed that the BC nanofibers were imbedded in the GO wrinkled sheets. Raman spectra showed the D and G bans of BC-GO shifted towards higher frequency. Fourier transform infrared (FT-IR) spectroscopy spectra confirmed a hybrid structure was successfully obtained. Cyclic voltammetry (CV) results showed the BC-GO modified electrode had the best electrochemical activity. Nitrite could be oxidized using the BC-GO modified electrode in a wide range of pHs. The amperometric response result indicated the BC-GO modified GCE can be used to determine nitrite concentration in a wide linear range of 0.5 to 4590 μM with detection limit and sensitivity of 0.2 μM and 527.35 μA μM cm, respectively. The BC-GO nitrite sensor also showed good anti-interference and real sample analysis performances. [ABSTRACT FROM AUTHOR]

Although bacterial cellulose (BC) and bacterial cellulose nanocrystals (BCNs) have considered to be edible, non-toxic, biocompatible and biodegradable, there is still the dearth of reports of BC and BCNs as the emulsifiers of Pickering emulsions with respect to the applications in foods, cosmetics and medicines. In this work, BC with ultrafine network architecture and 8–40 nm crystalline microfibrils in diameter was produced by Acetobacter xylinum , and then it was hydrolyzed by sulfuric acid followed by the oxidation of hydrogen peroxide to prepare BCNs. The physicochemical properties of BC and BCNs were contrastively evaluated by FT-IR, XRD, TGA and dynamic light scattering (DLS). The emulsifying performances of BC and BCNs in the stabilization of olive oil Pickering emulsion were further evaluated by optical microscope (OM) and fluorescent microscope (FM). Experimental results showed that the sulfuric acid hydrolysis of BC induced the removal of the amorphous components and the cleavage of the crystalline microfibrils, making BCNs possess the initiating decomposition temperature of 350 °C, the crystallinity index (CrI) of 89.6%, average size of 259.6 nm with PDI of 0.26 and zeta potential at about −34.8 mV, which exhibited high thermal stability and good emulsifying performance in comparison with BC. Furthermore, the effects of pH and ionic strength on emulsion stability were also investigated. In comparison to BC, BCNs were more sensitive in response to the change of pH and ionic strength. [ABSTRACT FROM AUTHOR]

Bacterial cellulose had been proven to be a very versatile natural polymer produced by bacteria. One of the major constraints in producing bacterial cellulose is the high cost of fermentation medium. This study examines the potential use of papaya juice as a lowcost fermentation medium for the production of bacterial cellulose. The fermentation of Acetobacter xylinum 0416 was carried out under static fermentation with an initial pH of 5.5, a temperature of 28±1°C and a fermentation period of 5 days using different juice extracted from ripe and unripe papaya. The highest production of bacterial cellulose was detected in ripe papaya pulp juice with a total weight of 35.37 g/l. Juice obtained from various parts of the fruit produced bacterial cellulose between 3.33 g/l and 16.10 g/l. By referring to the standard medium (Hestrin-Schramm (HS) medium), ripe papaya pulp juice shows the highest potential to be used as an alternative for the production of bacterial cellulose. This is due to its high glucose concentration that provide suitable conditions for A.xylinum 0416 to grow and produce bacterial cellulose. [ABSTRACT FROM AUTHOR]

Herein, bacterial cellulose (BC) was synthesized by acetobacter xylinum via organic acid pre-hydrolysis liquor of agricultural corn stalk used as carbon source. Acetic acid was applied to pretreat the corn stalk, then, the prehydrolysate was detoxified by sequential steps of activated carbon and ion exchange resin treatment prior to use as carbon source to cultivate acetobacter xylinum. Moreover, the recovery of acetic acid was achieved for facilitating the reduction of cost. The results revealed that the combination method of detoxification treatment was very effective for synthesis of BC, yield could be up to 2.86 g/L. SEM analysis showed that the diameter size of BC between 20 and 70 mm. In summary, the process that bacterial cellulose was biosynthesized via prehydrolysate from agricultural corn stalk used as carbon source is feasible, and the ability to recover organic acid make it economical, sustainable and green, which fits well into the biorefinery concept. [ABSTRACT FROM AUTHOR]

Bacterial cellulose/lotus root starch (BC/LRS) composites were prepared by cultivating Acetobacter xylinum in nutrient media containing gelatinized lotus root starch. Low concentrations of gelatinized LRS had increased BC production with the maximum value at 6.67 g/L when 5 g/L of LRS was added in the culture media and the composites had thicker and denser fibrils compared with those of BC with low concentrations of LRS (2.5 and 5 g/L). When the concentration of LRS was increased above 7.5 g/L, the morphology of the BC/LRS composites contained more fibril layers that were linked with LRS. The results from X-ray diffraction (XRD) demonstrated that there was no significant difference in structure between BC and BC/LRS composites except a slight increase in crystallinity for BC/LRS composites as the concentration of LRS was lifted up. The tensile tests were performed to display BC/LRS composites prepared with LRS concentration at 2.5 and 5 g/L in media had the tensile strength of 54 and 60 MPa, respectively, which indicated an improvement in mechanical property compared to the unmodified BC (45 MPa). Live/dead assay with chondrocytes seeded on BC/LRS composite revealed higher cell viability ranging from 85% to 90% than BC. Furthermore, cell morphology with typical spindle shape was observed on the surfaces of BC/LRS composite by confocal microscope. Through the overall results, it shows that this study has provided a guidance to prepare BC/LRS composites with better cell biocompatibility and higher mechanical strength than those of BC for the potential use in cartilage tissue engineering. [ABSTRACT FROM AUTHOR]

This study investigated cellulose production and microstructure variation from six Komagataeibacter strains (ATCC 53524, ATCC 10245, ATCC 23769, ATCC 700178, NBRC 13693 and KTH 5655). Strain KTH 5655 produced the highest cellulose yields (10.39 g/l) after 9 days cultivation. Nuclear magnetic resonance spectroscopy and X-ray diffraction revealed that strain ATCC 23769 synthesised cellulose with the lowest crystallinity and decreased ratio of Iα/Iβ allomorph, whilst strain KTH 5655 produced a relatively ordered cellulose structure. However, the average widths of cellulose ribbons were similar (30-50 nm) for all types of cellulose. Phylogenetic analysis of the 16S rRNA gene indicated that these strains shared a high level of genetic similarity (ranging from 88 to 98%). All strains were used to produce cellulose in the presence of arabinoxylan or xyloglucan as simplified cell wall analogues. Our results provide guidance for the selection of cellulose-producing strains for specific biotechnological and research applications. [ABSTRACT FROM AUTHOR]

Bacterial cellulose (BC) is a promising and renewable nanomaterial due to its unique structural features and appealing properties. Intensive study on BC preparation has been mainly focused on biosynthesis by certain bacteria, while the high economic costs of fermentation, especially the carbon sources, remain challenges to its application. In this study, bacterial cellulose was synthesized by Acetobacter xylinum with the acetic acid hydrolysate of bagasse used as carbon source. After the bagasse was pretreated by acetic acid, the components in hydrolysate and the removal rate was investigated, and the pretreatment conditions were optimized as follows: temperature of 160 °C, heating time of 60 min, addition of acetic acid of 2.0% (m/m), and solid-to-liquid ratio of 1/5. Prior to Acetobacter xylinum cultivation, the hydrolysate was detoxified by activated carbon. The detoxification process was very efficient for BC production, with a yield up to 2.13 g/L when the dosage of activated carbon was 5% (m/V). Furthermore, the obtained BC was characterized by scanning electron microscopy (SEM), which showed that the ribbons width of BC was between 30 and 80 nm. X-ray patterns showed the crystallinity value was 74.6 % and the crystallinity index (CI%) was 66.5 %, which also evidenced the presence of peaks characteristic of Cellulose I polymorph. In conclusion, it is feasible to produce BC from bagasse hydrolysate. This model of waste recycling could aid in the development of sustainable strategies. [ABSTRACT FROM AUTHOR]

The properties of a polymer synthesized by the Gluconacetobacter hansenii strain GH-1/2008 were investigated. The studied bacterial cellulose polymer films are characterized by a mesh nanostructure composed of micro- and macrofibrils, a high water absorption capacity 556 ± 16.8%, and high strength and elasticity. Analysis of the spectrum recorded by С CP/MAS NMR spectroscopy showed that the bacterial cellulose synthesized by G. hansenii GH-1/2008 is a pure compound composed of Iα (65-70%) and Iβ (30-35%) allomorphs without any other impurities. It was found that the bacterial cellulose films with adsorbed antibiotics such as amoxiclav and fluconazole can be used as antibacterial and antifungal wound healing materials. [ABSTRACT FROM AUTHOR]

Fiber growing inside the cotton bolls is a highly demandable product and its quality is key to the success of the textile industry. Despite the various efforts to improve cotton fiber staple length Pakistan has to import millions of bales to sustain its industrial needs. To improve cotton fiber quality Bacterial cellulose synthase (Bcs) genes (acsA, acsB) were expressed in a local cotton variety CEMB-00. In silico studies revealed a number of conserved domains both in the cotton-derived and bacterial cellulose synthases which are essential for the cellulose synthesis. Transformation efficiency of 1.27% was achieved by using Agrobacterium shoot apex cut method of transformation. The quantitative mRNA expression analysis of the Bcs genes in transgenic cotton fiber was found to be many folds higher during secondary cell wall synthesis stage (35 DPA) than the expression during elongation phase (10 DPA). Average fiber length of the transgenic cotton plant lines S-00–07, S-00–11, S-00–16 and S-00–23 was calculated to be 13.02% higher than that of the non-transgenic control plants. Likewise, the average fiber strength was found to be 20.92% higher with an enhanced cellulose content of 22.45%. The mutated indigenous cellulose synthase genes of cotton generated through application of CRISPR/Cas9 resulted in 6.03% and 12.10% decrease in fiber length and strength respectively. Furthermore, mature cotton fibers of transgenic cotton plants were found to have increased number of twists with smooth surface as compared to non-transgenic control when analyzed under scanning electron microscope. XRD analysis of cotton fibers revealed less cellulose crystallinity index in transgenic cotton fibers as compared to control fibers due to deposition of more amorphous cellulose in transgenic fibers as a result of Bcs gene expression. This study paved the way towards unraveling the fact that Bcs genes influence cellulose synthase activity and this enzyme helps in determining the fate of cotton fiber length and strength. • The present study revolves around interspecific gene transfer i.e. transformation of bacterial cellulose synthase (Bcs) genes from Acetobacter xylinum into a local cotton variety of Gossypium hirsutum through genetic engineering to attain the goal of improving cotton fiber quality. • In-silico analysis revealed compatibility of the substrate (UDP-Glc) with the bacterial cellulose synthase and formed basis for transformation of the transgenes in cotton fiber due to the fact that same substrate is also used by the cotton fiber cellulose synthases to synthesize cellulose. • Biochemical and fiber analyses of the transgenic cotton plants depicted a direct relationship between the fiber strength and cellulose contents. • The Scanning Electron Microscopic (SEM) analysis revealed a distinct topology of transgenic cotton fibers with increased number of twists and smoother surfaces as compared to the non-transgenic control plant fibers. • XRD analysis of cotton fibers revealed less cellulose crystallinity index in transgenic cotton fibers as compared to control fibers due to deposition of more amorphous cellulose in transgenic fibers as a result of Bcs gene expression • Significance of Bcs genes in improving cotton fiber quality was determined by CRISPR Cas9 technology by knocking out the indigenous cotton fiber cellulose synthase genes in advanced generation of transgenic cotton. [ABSTRACT FROM AUTHOR]

The aim of the study was to analyze the changes in the parameters of bacterial cultures and bacterial cellulose (BC) synthesized by four reference strains of Gluconacetobacter xylinus during 31-day cultivation in stationary conditions. The study showed that the most visible changes in the analyzed parameters of BC, regardless of the bacterial strain used for their synthesis, were observed in the fi rst 10-14 days of the experiment. It was also revealed, that among parameters showing dependence associated with the particular bacterial strain were the rate and period of BC synthesis, the growth rate of bacteria anchored to the cellulose fi brils, the capacity to absorb water and the water release rate. The results presented in this work may be useful in the selection of optimum culturing conditions and period from the point of view of good effi ciency of the cellulose synthesis process. [ABSTRACT FROM AUTHOR]

Aims To offset the negative effects of aeration on bacterial cellulose (BC) production by acetic acid bacteria using enmeshed cellulose microfibrils (CM) on luffa sponge matrices (LSM). Methods and Results The CM were enmeshed on LSM (LSM-CM). The optimal amount of LSM-CM was determined for BC production under aerated conditions. Without LSM-CM, no BC was produced in seven out of nine production cycles at the highest aeration rate (9 l min−1). However, with 0·5% LSM-CM and an aeration rate of 3 l min−1, a satisfactory oxygen transfer coefficient was achieved, and also a good yield of BC (5·24 g l−1). Moreover, the LSM-CM was able to be recycled through nine consecutive BC production cycles. The highest BC yields (from 5·8 ± 0·4 to 6·6 ± 0·4 g l−1) were associated with high bacterial biomass and this was confirmed by scanning electron microscopy. Conclusions We confirm that LSM-CM works well as a starter. Microenvironments low in dissolved oxygen within the matrices of LSM-CM are important for BC production under aeration conditions. Significance and Impact of the Study The LSM-CM provides a microenvironment which offsets the negative effects of aeration on BC production. A sustainable, economic process for mass BC production is described using recycled LSM-CM with aeration. [ABSTRACT FROM AUTHOR]

Bacterial nanocellulose (BNC) is a nanofibrilar polymer produced by strains such as Gluconacetobacter xylinus, one of the best bacterial species which given the highest efficiency in cellulose production. Bacterial cellulose is a biomaterial having unique properties such as: chemical purity, good mechanical strength, high flexibility, high absorbency, possibility of forming any shape and size and many others. Such a large number of advantages contributes to the widespread use of the BNC in food technology, paper, electronic industry, but also the architecture in use. However, the greatest hopes are using the BNC in medicine. This text contains information about bacterial nanocellulose, its specific mechanical and biological properties and current applications. [ABSTRACT FROM AUTHOR]

The research aimed to know the production of cellulose in tofu liquid waste, the effect of adding ammonium sulfate to the nata de soya, and the quality nata de soya produced from Tofu Liquid Waste. The parameters used are the determination of the thickness and weight, measure of water, and fiber test of nata de soya. By using variations of the addition of ammonium sulfate 10 g, 15 g, 20 g, and 25 g. 35 grams of sugar in 500 mL of tofu liquid waste, starter bacteria Acetobacter xylinum as much 100 mL, and fermented for 14 days at a temperature of 28-30oC. The quality nata de soya highest of the addition 15 grams of ammonium sulfate with a thickness of 1.7 cm, weight 231.0 grams, the lowest water content of 94.23% and the highest fiber content of 2.41%.

Bacterial cellulose membrane synthesized by Acetobacter xylinum in coconut water medium has potential application for Guided bone Regeneration. However, this membrane may not meet some application requirements due to its low biodegradation properties. In this paper, incorporation of gamma irradiation into the membrane is a developed strategy to increase its biodegradability properties. The in–vitro degradation study in synthetic body fluid (SBF) of the irradiated membrane has been analyzed during periods of 6 months by means of weight loss, mechanical properties and scanning electron microscopy observation compared to that the un-irradiated one. The result showed that weight loss of irradiated membrane with 25 kGy and 50 kGy and immersed in SBF solution for 6 months reached 18% and 25% respectively. While un-irradiated membrane did not give significant weight loss. Tensile strength of membranes decreases with increasing of irradiation dose and further decreases in tensile strength is observed when irradiated membrane was followed by immersion in SBF solution. Microscope electron image of cellulose membranes shows that un-irradiated bacterial cellulose membrane consists of dense ultrafine fibril network structures, while irradiation result in cleavage of fibrils network of cellulose. The fibrils network become loosely after irradiated membrane immersed in SBF solution due to released of small molecular weight carbohydrates formed during by irradiation from the structure