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1
Istirokhatun, Titik, Ulva Yuni, Pertiwi Andarani, and Heru Susanto. "Do ZnO and Al2O3 Nanoparticles Improve the Anti-Bacterial Properties of Cellulose Acetate-Chitosan Membrane?" MATEC Web of Conferences 156 (2018): 08009. http://dx.doi.org/10.1051/matecconf/201815608009.
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Biofouling, due to the existence of bacteria in water, becomes one of the barriers in cellulose acetate (CA) membrane applications. Although chitosan has been incorporated into CA membranes, its antimicrobial activity has not been improved significantly yet. In this study, cellulose acetate-chitosan membranes were prepared by modification using ZnO and Al2O3 nanoparticles during phase separation method. The membranes were then characterized in term of water permeability, and surface morphology. The anti-bacteria property was examined by using gram-negative bacteria. Modification of cellulose acetate-chitosan membranes with ZnO and Al2O3 nanoparticles have not shown optimal results where no clear zones around the membrane are visible.
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Nichita, Ileana, Lavinia Lupa, Radu Valentin Gros, Aurelia Visa, Adriana Popa, Iulia Bucur, and Emil Tirziu. "The Effect of Cellulose Acetate in the Inhibition of Bacteria: an Alternative for Antimicrobial Resistance." Revista de Chimie 71, no. 9 (September 5, 2020): 23–31. http://dx.doi.org/10.37358/rc.20.9.8313.
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Cellulose acetate (CA) is one of the most important esters of cellulose and it was analyzed by means of Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and EDX spectra. The FT-IR spectrum presented both the C=O and C�O stretching bands for acetyl groups. The EDX spectrum confirms the presence of C and O elements. The SEM image presented a spongy structure that is important for many applications. The antimicrobial properties of cellulose acetate solutions in acetic acid were determined in tests on two gram-negative species (Pseudomonas aeruginosa - ATCC 27853 and Escherichia coli - ATCC 25822), two gram-positive species (Staphylococus aureus - ATCC 29213 and Streptococcus pyogenes - ATCC 19615) and yeast species (Candida albicans - ATCC 10231). We have shown that samples of cellulose acetate solutions in acetic acid can be used to fight microbial and fungal infections. Of the gram-positive species tested, the strongest antimicrobial effect was observed against S. aureus. The diameter of inhibition zones of cellulose acetate solutions in acetic acid (P1 and P2) for S. aureus far exceeded inhibition zone both of reference substance (gentamicin) and of acetic acid solutions (M1 and M2), given values between 3.15 cm (P1) and 3.55 cm (P2). Also, the results suggested that the studied solutions (P1 and P2) had an antimicrobial effect pronounced for gram-negative species as P. aeruginosa, in which the P1 sample gave an inhibition zone of 2.95 cm, and the P2 sample achieved an inhibition of 3.15 cm. So, the antimicrobial activity of cellulose acetate solutions tested in vitro had a good antimicrobial effect, proportional to the concentration of the active substance.
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Milovanovic, Stoja, Tijana Adamovic, Ksenija Aksentijevic, Dusan Misic, Jasna Ivanovic, and Irena Zizovic. "Cellulose Acetate Based Material with Antibacterial Properties Created by Supercritical Solvent Impregnation." International Journal of Polymer Science 2017 (2017): 1–9. http://dx.doi.org/10.1155/2017/8762649.
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Supercritical CO2 was used as a green solvent and impregnation medium for loading cellulose acetate beads with carvacrol in order to obtain a biomaterial with antibacterial properties. Supercritical solvent impregnation was performed in a high-pressure view cell at temperature of 50°C and pressures of 10, 21, and 30 MPa with the processing time ranging from 2 to 18 h. The rate of impregnation increased with the pressure increase. However, maximum impregnation yield (round 60%) was not affected by the pressure applied. Selected samples of the impregnated cellulose acetate containing 6–60% of carvacrol were proven to have considerable antibacterial effect against Gram-positive and Gram-negative bacterial strains including methicillin-resistant Staphylococcus aureus which causes severe infections in humans and animals. In addition, cellulose acetate beads containing 6.0–33.6% of carvacrol were shown to have a porous structure with submicron pores which is of interest for the controlled delivery applications.
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Zannagui, Chahid, Hassan Amhamdi, Soufian El Barkany, Issam Jilal, Ola Sundman, Amin Salhi, Mohamed Abou-Salama, and Abderahmane El Idrissi. "Homogeneous succinylation of cellulose acetate: Design, characterization and adsorption study of Pb(II), Cu(II), Cd(II) and Zn(II) ions." E3S Web of Conferences 240 (2021): 02003. http://dx.doi.org/10.1051/e3sconf/202124002003.
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In this study, the removal of Pb(II), Cu(II), Cd(II), and Zn(II) ions from aqueous solutions was investigated using succinic anhydride modified cellulose monoacetate. In the first part, the cellulose acetate was successfully succinylated in a homogenous medium of DMF using 4-dimethylaminopyridine (DMAP) as a catalyst. The obtained material (AcS) was analyzed by FTIR and CP/MAS 13C NMR Spectroscopy, thermogravimetry analysis and DRX patterns. The titration method was used to determinate the degree of hydroxyl group substituted by carboxyl group (DS) and was found to be 1.36. In the second part, the Bach technique was used to study the effects of pH, contact time, concentration of metals, ionic selectivity and regeneration. Maximum sorption capacities of AcS for Pb(II), Cu(II), Cd(II), and Zn(II) were 241.81, 133.76, 156.61 and 73,58 mg.g-1, respectively. The Langmuir isotherm and the pseudo second order kinetic models provided best fit to the experimental data of metal ion sorption. The nature of the adsorption process was exothermic and spontaneous in nature with negative values of ΔG° and ΔH°. Regeneration of the modified cellulose acetate was accomplished using nitric solution and showed high stability and good recyclability.
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Wibisono, Yusuf, Shari Amalia Rachmawati, Vera Septyaningrum Mylani, Nimatul Izza, Angky Wahyu Putranto, and Shinta Rosalia Dewi. "Synthesis of Anti-biofoulant Green Nanoparticles Embedded Cellulose Acetate Membranes." Proceedings 69, no. 1 (November 4, 2020): 41. http://dx.doi.org/10.3390/cgpm2020-07199.
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Membranes were used in many aqueous applications, including in food processing, e.g., clarification of fruit juices. Typical drawbacks of membrane processes are membrane fouling, which promotes deterioration of processed products. During application of membranes for fruit juice clarification, biofouling occurred as the process deals with food substances. Biofouling is commonly dominated by bacterial attachment and growth on membrane surface, following the deposition of organic molecules from food substances. Natural antibiotics such as Olea europaea leaves extract might be used to improve the antibiofouling properties of membranes due to its phenolic contents. In this work, Olea europaea substances were obtained by extraction to get the green active solid nanoparticles. Phenolic green nanoparticles then filled into cellulose acetate as membrane matrix. The mixed matrix membrane, therefore, has a safe antibiofouling properties and is suitable for food application. The anti-biofoulant effect has been proven by decreasing bacterial attachment down to 23% from initial condition, especially for Gram-negative bacteria such as Eschericia coli.
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Xu, Fenghua, Baicheng Weng, Luis A. Materon, Anxiu Kuang, Jorge A. Trujillo, and Karen Lozano. "Fabrication of cellulose fine fiber based membranes embedded with silver nanoparticles via Forcespinning." Journal of Polymer Engineering 36, no. 3 (April 1, 2016): 269–78. http://dx.doi.org/10.1515/polyeng-2015-0092.
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Abstract This study presents the successful development of cellulose fiber based membranes embedded with silver nanoparticles. These fine fiber membranes were developed utilizing the Forcespinning (FS) technique followed by alkaline hydrolysis treatment. The fiber morphology, homogeneity and yield were optimized by varying spinning parameters such as polymer concentration and angular velocity of the spinnerets. The structure, thermal and mechanical properties, and water absorption capability of the developed membranes were investigated. The cellulose acetate (CA) present in the membrane was converted to cellulose in the presence of embedded silver nanoparticles by alkaline hydrolysis. The silver nanoparticles embedded cellulose membrane exhibits outstanding water absorption capacity with fast uptake rate. Its high porosity, three-dimensional network structure with well-interconnected pores, as well as the intrinsically highly hydrophilic nature of cellulose material greatly favor its potential application as wound dressings. The antimicrobial activity was evaluated by the disk diffusion method. The composite membranes exhibit excellent antimicrobial activity against Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa, and Gram-positive Staphylococcus aureus, owing to the slow and sustained release of embedded silver nanoparticles.
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Pang, Jin-Hui, Xin Liu, Miao Wu, Yu-Ying Wu, Xue-Ming Zhang, and Run-Cang Sun. "Fabrication and Characterization of Regenerated Cellulose Films Using Different Ionic Liquids." Journal of Spectroscopy 2014 (2014): 1–8. http://dx.doi.org/10.1155/2014/214057.
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The demand for substitution of fossil-based materials by renewable bio-based materials is increasing with the fossil resources reduction and its negative impacts on the environment. In this study, environmentally friendly regenerated cellulose films were successfully prepared using 1-allyl-3-methylimidazolium chloride (AmimCl), 1-butyl-3-methylimidazolium chloride (BmimCl), 1-ethyl-3-methylimidazolium chloride (EmimCl), and 1-ethyl-3-methylimidazolium acetate (EmimAc) as solvents, respectively. The results of morphology from scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed that all the cellulose films possessed smooth, highly uniform, and dense surface. The solid-state cross-polarization/magic angle spinning (CP/MAS)13C NMR spectra and X-ray diffraction (XRD) corroborated that the transition from cellulose I to II had occurred after preparation. Moreover, it was shown that the ionic liquid EmimAc possessed much stronger dissolubility for cellulose as compared with other ionic liquids and the cellulose film regenerated from EmimCl exhibited the most excellent tensile strength (119 Mpa). The notable properties of regenerated cellulose films are promising for applications in transparent biodegradable packaging and agricultural purpose as a substitute for PP and PE.
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Ariyanti, Dhita, Nurul Widiastuti, and Nourma Safarina. "Kinerja Membran Plat Berpori Berbasis Selulosa Asetat yang Disintesis Secara Inversi Fasa untuk Ultrafiltrasi Bakteri E.coli di PDAM Surabaya." Jurnal Teknologi Lingkungan 21, no. 2 (July 30, 2020): 165–73. http://dx.doi.org/10.29122/jtl.v21i2.3945.
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ABSTRACTThe lack of consumable water in urban and industrial-dense areas encourages research on clean water treatment methods. Some current treatment methods, such as precipitation, adsorption, and UV light irradiation are ineffective for water with high levels of suspended solids, organic matter, and turbidity. Therefore, alternative approaches are required to support the availability of clean and consumable water. The membrane technology is an alternative filtration method proposed in the East Surabaya's municipal waterworks area. The membrane filtration method is quite simple and easy to operate. This study aimed to determine the performance of cellulose acetate-based porous plate membranes synthesized by phase inversion for E. coli bacteria's ultrafiltration. As a raw material, cellulose acetate is preferred because of its high hydrophilicity and good biocompatibility. Membrane synthesis was carried out through the phase inversion method with acetone solvents and non-solvent water in the coagulation bath. The positive test for E. coli bacteria was carried out through the MPN (Most Probable Number) method on the municipal waterworks water samples before and after filtering with membranes. The results showed that the synthesis of cellulose acetate membrane had good homogeneity. This result was supported by the results of ANOVA single factor statistical data analysis. Also, cellulose acetate membrane had good permeability and flux performance as ultrafiltration of E. coli bacteria with a flux of 37.25 L/m2.hour.bar at a sufficient pressure of 5 bar. Test results for the presence of E. coli bacteria in PDAM water samples using the MPN method gave an initial indication that the water sample after filtration with cellulose acetate membrane was negative. Keywords: membrane, cellulose acetate, permeability, water fluxABSTRAKMinimnya air bersih yang layak konsumsi di daerah perkotaan dan padat industri mendorong penelitian tentang metode pengolahan air bersih. Kurangnya efektivitas metode pengolahan sebelumnya seperti pengendapan, adsorbsi, dan penyinaran dengan sinar UV untuk air dengan kadar suspended solids, zat organik, dan kekeruhan yang tinggi, diperlukan metode alternatif untuk mendukung ketersediaan air bersih layak konsumsi. Metode filtrasi alternatif yang ditawarkan di PDAM di kawasan Surabaya Timur. Metode filtrasi dengan membran sangat sederhana dan mudah dalam operasionalnya. Penelitian ini bertujuan untuk mengetahui kinerja membran plat berpori berbasis selulosa asetat yang disintesis secara inversi fasa untuk ultrafiltrasi bakteri E.coli. Selulosa asetat dipilih sebagai bahan baku membran karena selulosa asetat merupakan bahan polimer yang memiliki hidrofilitas tinggi dan biokompatibilitas yang baik. Sintesis membran dilakukan melalui metode inversi fasa dengan pelarut aseton dan nonpelarut air dalam bak koagulasi. Uji positif bakteri E.coli dilakukan melalui metode MPN (Most Probable Number) pada sampel air PDAM sebelum dan sesudah difiltrasi dengan membran. Hasil penelitian menunjukkan bahwa sintesis membran selulosa asetat memiliki homogenitas baik yang ditunjukkan oleh hasil analisis data statistika ANOVA single factor. Selain itu, membran selulosa asetat memiliki kinerja permeabilitas dan fluks yang baik sebagai ultrafiltrasi bakteri E.coli dengan ketercapaian fluks sebesar 37,25 L/m2.jam.bar pada tekanan efektif sebesar 5 bar. Hasil uji keberadaan bakteri E.coli pada sampel air PDAM dengan metode MPN memberikan indikasi awal bahwa sampel air setelah filtrasi dengan membran selulosa asetat adalah negatif.Kata kunci: membran, selulosa asetat, permeabilitas, fluks air
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Colburn, Andrew, Ronald J. Vogler, Aum Patel, Mariah Bezold, John Craven, Chunqing Liu, and Dibakar Bhattacharyya. "Composite Membranes Derived from Cellulose and Lignin Sulfonate for Selective Separations and Antifouling Aspects." Nanomaterials 9, no. 6 (June 7, 2019): 867. http://dx.doi.org/10.3390/nano9060867.
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Cellulose-based membrane materials allow for separations in both aqueous solutions and organic solvents. The addition of nanocomposites into cellulose structure is facilitated through steric interaction and strong hydrogen bonding with the hydroxy groups present within cellulose. An ionic liquid, 1-ethyl-3-methylimidazolium acetate, was used as a solvent for microcrystalline cellulose to incorporate graphene oxide quantum dots into cellulose membranes. In this work, other composite materials such as, iron oxide nanoparticles, polyacrylic acid, and lignin sulfonate have all been uniformly incorporated into cellulose membranes utilizing ionic liquid cosolvents. Integration of iron into cellulose membranes resulted in high selectivity (>99%) of neutral red and methylene blue model dyes separation over salts with a high permeability of 17 LMH/bar. With non-aqueous (alcohol) solvent, iron–cellulose composite membranes become less selective and more permeable, suggesting the interaction of iron ions cellulose OH groups plays a major role in pore structure. Polyacrylic acid was integrated into cellulose membranes to add pH responsive behavior and capacity for metal ion capture. Calcium capture of 55 mg Ca2+/g membrane was observed for PAA-cellulose membranes. Lignin sulfonate was also incorporated into cellulose membranes to add strong negative charge and a steric barrier to enhance antifouling behavior. Lignin sulfonate was also functionalized on the commercial DOW NF270 nanofiltration membranes via esterification of hydroxy groups with carboxyl group present on the membrane surface. Antifouling behavior was observed for both lignin-cellulose composite and commercial membranes functionalized with lignin. Up to 90% recovery of water flux after repeated cycles of fouling was observed for both types of lignin functionalized membranes while flux recovery of up to 60% was observed for unmodified membranes.
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Roberts, E. M., I. M. Saxena, and R. M. Brown. "Does cellulose II occur in nature?" Proceedings, annual meeting, Electron Microscopy Society of America 47 (August 6, 1989): 780–81. http://dx.doi.org/10.1017/s0424820100155876.
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Cellulose, a carbohydrate polymer of :ß-D-glucose, occurs in several different crystalline forms called allomorphs. “Cellulose II” is by far the most abundant allomorph found in nature, but a few organisms have been suggested to synthesize another crystalline form called “cellulose II” (summarized in). Some of these reports are now considered uncertain due to the presence of clay contaminants or because extractions requiring high concentrations of alkali can convert cellulose I to cellulose II. Because identification of organisms that synthesize native cellulose II could help further understanding of how cellulose crystallization occurs, we have reexamined several of the organisms suggested to produce this allomorph. Care was taken to minimize the atrifacts mentioned above. Included in this study were the algae HalicystisandEnteromorpha, and the slime mold Dictyostelium.In the course of our studies, we have also found that certain mutants of the bacterium Acetobacter xylinum synthesize cellulose II instead of the cellulose I allomorph produced by the wild type.Bacterial cellulose was purified from mutants of Acetobacter xylinum as previously described. After extraction in organic solvents, cellulose was purified from Halicystis (UTEX strain 1260) by brief treatment with 15-20% HCl at 100°C and extraction with 1N NaOH and 0.25M NaBH4 (2 x 30 minutes, 100°C). The ultrastructure of these samples were examined by negative staining with uranyl acetate. Cellulose from Enteromorpha (UTEX strain 739) was purified as described above or extracted by soaking overnight in 24% KOH at room temperature. X-ray diffraction powder patterns were recorded with a Debye-Scherrer camera and Cu k-alpha radiation. The crystalline form of cellulose from stalks of Dictyostelium discoidium was studied by electron diffraction. Individual stalks were harvested and cleaned in dilute HCl. Electron diffraction patterns produced at 120 kV were recorded on Kodak 35 mm Tri-X film.
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Ravikumar, Preethi, and Suresh Sagadevan. "Influence of the addition of chitin nanocrystals on the characteristics of cellulose acetate films." Polimery 66, no. 2 (February 17, 2021): 98–104. http://dx.doi.org/10.14314/polimery.2021.2.2.
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The present study deals with chitin nanocrystal (CHNC)-reinforced cellulose acetate (CA) films formed by the solvent casting method that makes use of poly(ethylene glycol) (PEG) as a plasticizing agent. Three different films containing various mass ratios of CHNCs (0.5, 1, and 2 wt %) in CA were investigated for hydrophilicity, mechanical properties, soil degradation, strength, water solubility, light transmittance, and antifungal activity. From the FT-IR analysis, no detectable shifts to the cellulose acetate bands with the loading of small amounts of CHNCs were observed. However, the light transmittance capacity of CA films decreased due to chitin addition. The chitosan incorporation enhanced the hydrophilic character of CA films, and also, the mechanical properties of the lower percentage of CHNCs in CA, like Young’s modulus, had a slight positive effect, while the tensile strength and elongation at breaks – had a negative influence. Finally, an increasing trend of antifungal activity with that of increased CHNC content was observed, i.e., the 2 wt % CHNCs containing CA film showed an inhibition rate (FGI) of 35%, 1 wt % CHNCs had a 15% inhibition rate, which is higher than that of 0.5 wt % CHNCs and pure CA, thereby indicating the potential role of CHNCs-reinforced CA films for packaging applications.
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Yamada, Shunji, Eisuke Chikayama, and Jun Kikuchi. "Signal Deconvolution and Generative Topographic Mapping Regression for Solid-State NMR of Multi-Component Materials." International Journal of Molecular Sciences 22, no. 3 (January 22, 2021): 1086. http://dx.doi.org/10.3390/ijms22031086.
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Solid-state nuclear magnetic resonance (ssNMR) spectroscopy provides information on native structures and the dynamics for predicting and designing the physical properties of multi-component solid materials. However, such an analysis is difficult because of the broad and overlapping spectra of these materials. Therefore, signal deconvolution and prediction are great challenges for their ssNMR analysis. We examined signal deconvolution methods using a short-time Fourier transform (STFT) and a non-negative tensor/matrix factorization (NTF, NMF), and methods for predicting NMR signals and physical properties using generative topographic mapping regression (GTMR). We demonstrated the applications for macromolecular samples involved in cellulose degradation, plastics, and microalgae such as Euglena gracilis. During cellulose degradation, 13C cross-polarization (CP)–magic angle spinning spectra were separated into signals of cellulose, proteins, and lipids by STFT and NTF. GTMR accurately predicted cellulose degradation for catabolic products such as acetate and CO2. Using these methods, the 1H anisotropic spectrum of poly-ε-caprolactone was separated into the signals of crystalline and amorphous solids. Forward prediction and inverse prediction of GTMR were used to compute STFT-processed NMR signals from the physical properties of polylactic acid. These signal deconvolution and prediction methods for ssNMR spectra of macromolecules can resolve the problem of overlapping spectra and support macromolecular characterization and material design.
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Kato, Souichiro, Shin Haruta, Zong Jun Cui, Masaharu Ishii, and Yasuo Igarashi. "Stable Coexistence of Five Bacterial Strains as a Cellulose-Degrading Community." Applied and Environmental Microbiology 71, no. 11 (November 2005): 7099–106. http://dx.doi.org/10.1128/aem.71.11.7099-7106.2005.
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ABSTRACT A cellulose-degrading defined mixed culture (designated SF356) consisting of five bacterial strains (Clostridium straminisolvens CSK1, Clostridium sp. strain FG4, Pseudoxanthomonas sp. strain M1-3, Brevibacillus sp. strain M1-5, and Bordetella sp. strain M1-6) exhibited both functional and structural stability; namely, no change in cellulose-degrading efficiency was observed, and all members stably coexisted through 20 subcultures. In order to investigate the mechanisms responsible for the observed stability, “knockout communities” in which one of the members was eliminated from SF356 were constructed. The dynamics of the community structure and the cellulose degradation profiles of these mixed cultures were determined in order to evaluate the roles played by each eliminated member in situ and its impact on the other members of the community. Integration of each result gave the following estimates of the bacterial relationships. Synergistic relationships between an anaerobic cellulolytic bacterium (C. straminisolvens CSK1) and two strains of aerobic bacteria (Pseudoxanthomonas sp. strain M1-3 and Brevibacillus sp. strain M1-5) were observed; the aerobes introduced anaerobic conditions, and C. straminisolvens CSK1 supplied metabolites (acetate and glucose). In addition, there were negative relationships, such as the inhibition of cellulose degradation by producing excess amounts of acetic acid by Clostridium sp. strain FG4, and growth suppression of Bordetella sp. strain M1-6 by Brevibacillus sp. strain M1-5. The balance of the various types of relationships (both positive and negative) is thus considered to be essential for the stable coexistence of the members of this mixed culture.
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Robert, Céline, Christophe Chassard, Paul A. Lawson, and Annick Bernalier-Donadille. "Bacteroides cellulosilyticus sp. nov., a cellulolytic bacterium from the human gut microbial community." International Journal of Systematic and Evolutionary Microbiology 57, no. 7 (July 1, 2007): 1516–20. http://dx.doi.org/10.1099/ijs.0.64998-0.
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A strictly anaerobic cellulolytic bacterium, strain CRE21T, was isolated from a human faecal sample. Cells were Gram-negative non-motile rods that were about 1.7 μm in length and 0.9 μm in width. Strain CRE21T degraded different types of cellulose and was able to grow on a variety of carbohydrates. Cellulose and sugars were mainly converted to acetate, propionate and succinate. The G+C content of the DNA was 41.1 mol%. 16S rRNA gene sequence analysis revealed that the isolate belonged to the genus Bacteroides with highest sequence similarity to the type strain of Bacteroides intestinalis (98 %). DNA–DNA hybridization results revealed that strain CRE21T was distinct from B. intestinalis (40 % DNA–DNA relatedness). Strain CRE21T also showed several characteristics distinct from B. intestinalis. In particular, it exhibited different capacity to degrade polysaccharides such as cellulose. On the basis of phylogenetic analysis and the morphological, physiological and biochemical data presented in this study, strain CRE21T can be readily differentiated from recognized species of the genus Bacteroides. The name Bacteroides cellulosilyticus sp. nov. is proposed to accommodate this organism. The type strain is CRE21T (=DSM 14838T=CCUG 44979T).
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Koeck, Daniela E., Wolfgang Ludwig, Gerhard Wanner, Vladimir V. Zverlov, Wolfgang Liebl, and Wolfgang H. Schwarz. "Herbinix hemicellulosilytica gen. nov., sp. nov., a thermophilic cellulose-degrading bacterium isolated from a thermophilic biogas reactor." International Journal of Systematic and Evolutionary Microbiology 65, Pt_8 (August 1, 2015): 2365–71. http://dx.doi.org/10.1099/ijs.0.000264.
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Phenotypic and phylogenetic studies were performed on new isolates of a novel Gram-stain-positive, anaerobic, non-sporulating, rod-shaped bacterium isolated from a thermophilic biogas plant. The novel organisms were able to degrade crystalline cellulose. 16S rRNA gene comparative sequence analysis demonstrated that the isolates formed a hitherto unknown subline within the family Lachnospiraceae. As a representative of the whole group of isolates, strain T3/55T was further characterized. The closest relative of T3/55T among the taxa with validly published names is Mobilitalea sibirica, sharing 93.9 % 16S rRNA gene sequence similarity. Strain T3/55T was catalase-negative, indole-negative, and produced acetate, ethanol and propionic acid as major end products from cellulose metabolism. The major cellular fatty acids (>1 %) were 16 : 0 dimethyl acetal, 16 : 0 fatty acid methyl ester and 16 : 0 aldehyde. The DNA G+C content was 36.6 mol%. A novel genus and species, Herbinix hemicellulosilytica gen. nov., sp. nov., is proposed based on phylogenetic analysis and physiological properties of the novel isolate. Strain T3/55T ( = DSM 29228T = CECT 8801T), represents the type strain of Herbinix hemicellulosilytica gen. nov., sp. nov.
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Hurtuková, Klaudia, Klára Fajstavrová, Silvie Rimpelová, Barbora Vokatá, Dominik Fajstavr, Nikola Slepičková Kasálková, Jakub Siegel, Václav Švorčík, and Petr Slepička. "Antibacterial Properties of a Honeycomb-like Pattern with Cellulose Acetate and Silver Nanoparticles." Materials 14, no. 14 (July 20, 2021): 4051. http://dx.doi.org/10.3390/ma14144051.
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This study involved the preparation and characterization of structures with a honeycomb-like pattern (HCP) formed using the phase separation method using a solution mixture of chloroform and methanol together with cellulose acetate. Fluorinated ethylene propylene modified by plasma treatment was used as a suitable substrate for the formation of the HCP structures. Further, we modified the HCP structures using silver sputtering (discontinuous Ag nanoparticles) or by adding Ag nanoparticles in PEG into the cellulose acetate solution. The material morphology was then determined using atomic force microscopy (AFM) and scanning electron microscopy (SEM), while the material surface chemistry was studied using energy dispersive spectroscopy (EDS) and wettability was analyzed with goniometry. The AFM and SEM results revealed that the surface morphology of pristine HCP with hexagonal pores changed after additional sample modification with Ag, both via the addition of nanoparticles and sputtering, accompanied with an increase in the roughness of the PEG-doped samples, which was caused by the high molecular weight of PEG and its gel-like structure. The highest amount (approx. 25 at %) of fluorine was detected using the EDS method on the sample with an HCP-like structure, while the lowest amount (0.08%) was measured on the PEG + Ag sample, which revealed the covering of the substrate with biopolymer (the greater fluorine extent means more of the fluorinated substrate is exposed). As expected, the thickness of the Ag layer on the HCP surface depended on the length of sputtering (either 150 s or 500 s). The sputtering times for Ag (150 s and 500 s) corresponded to layers with heights of about 8 nm (3.9 at % of Ag) and 22 nm (10.8 at % of Ag), respectively. In addition, we evaluated the antibacterial potential of the prepared substrate using two bacterial strains, one Gram-positive of S. epidermidis and one Gram-negative of E. coli. The most effective method for the construction of antibacterial surfaces was determined to be sputtering (150 s) of a silver nanolayer onto a HCP-like cellulose structure, which proved to have excellent antibacterial properties against both G+ and G− bacterial strains.
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Yakubu, Azeh, Gabriel Ademola Olatunji, and Folahan Amoo Adekola. "Modified/Unmodified Nanoparticle Adsorbents of Cellulose Origin With High Adsorptive Potential for Removal of Pb(II) From Aqueous Solution." European Scientific Journal, ESJ 13, no. 27 (September 30, 2017): 425. http://dx.doi.org/10.19044/esj.2017.v13n27p425.
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This investigation was conducted to evaluate the adsorption capacity of nanoparticles of cellulose origin. Nanoparticles were synthesized by acid hydrolysis of microcrystalline cellulose/cellulose acetate using 64% H3PO4 and characterized using FTIR, XRD, TGA-DTGA, BET and SEM analysis. Adsorption kinetics of Pb (II) ions in aqueous solution was investigated and the effect of initial concentration, pH, time, adsorbent dosage and solution temperature. The results showed that adsorption increased with increasing concentration with removal efficiencies of 60% and 92.99% for Azeh2 and Azeh10 respectively for initial lead concentration of 3 mg/g. The effects of contact time showed that adsorption maximum was attained within 24h of contact time. The maximum adsorption capacity and removal efficiency were achieved at pH6. Small dose of adsorbent had better performance. The kinetics of adsorption was best described by the pseudo-second-Order model while the adsorption mechanism was chemisorption and pore diffusion based on intra-particle diffusion model. The isotherm model was Freundlich. Though, all tested isotherm models relatively showed good correlation coefficients ranging from 0.969-1.000. The adsorption process was exothermic for Azeh-TDI, with a negative value of -12.812 X 103 KJ/mol. This indicates that the adsorption process for Pb by Azeh-TDI was spontaneous. Adsorption by Azeh2 was endothermic in nature.
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Costa, E. C. B., G. G. L. Araújo, J. S. Oliveira, E. M. Santos, A. F. Perazzo, G. A. Pereira, F. N. S. Santos, and A. M. Zanine. "Effect of various salt concentrations on the ruminal parameters of goats." South African Journal of Animal Science 50, no. 4 (October 29, 2020): 635–42. http://dx.doi.org/10.4314/sajas.v50i4.15.
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The objective of this study was to evaluate the effects of various concentrations of sodium chloride (NaCl), magnesium chloride (MgCl2), and calcium chloride (CaCl2) on the growth and in vitro fermentation of cellulolytic, glycolytic, and amylolytic microorganisms from the rumen of a goat. Six concentrations of each salt were tested separately, namely 0 mg/dL, 100 mg/dL, 200 mg/dL, 400 mg/dL, 800 mg/dL, and 1600 mg/dL in the culture medium. The experiments were conducted in a completely randomized design, in a 6 x 3 factorial arrangement of salt concentration and substrate (starch, cellulose, and glucose) with three replications of each treatment combination. Concentrations of microbial protein, ammonia (NH3-N), and volatile fatty acids (acetate, propionate, and butyrate) were measured. A quadratic effect of CaCl2 concentration on the production of microbial protein was observed in the cellulose medium. The effect of MgCl2 on NH3-N production in the cellulose medium decreased linearly. Propionate concentration decreased linearly with increasing levels of NaCl and MgCl2 in the media containing starch. There was a decreasing linear effect of MgCl2 on the concentration of butyrate in the media containing glucose. In conclusion, concentrations of NaCl and CaCl2 up to 1,600 mg/dL did not affect the microbial activity of starch, cellulose, and glucose-fermenting organisms. However, the microbial activity of starch-fermenting microbes was inhibited at salt concentrations above 800 mg/dL. Thus, brackish water could be used by goats in semiarid regions, but its use should be managed carefully so that it does not have a negative impact on rumen microbial populations.Keywords: cellulose, glucose, saline water, starch, ruminants
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Bai, Yu, Xingjian Zhou, Na Li, Jinbiao Zhao, Hao Ye, Shiyi Zhang, Hongjian Yang, et al. "In Vitro Fermentation Characteristics and Fiber-Degrading Enzyme Kinetics of Cellulose, Arabinoxylan, β-Glucan and Glucomannan by Pig Fecal Microbiota." Microorganisms 9, no. 5 (May 16, 2021): 1071. http://dx.doi.org/10.3390/microorganisms9051071.
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Non-digestible polysaccharides are of great significance to human and animal intestinal health. Cellulose, arabinoxylan, β−glucan and glucomannan were selected in the present study to investigate the fermentation characteristics and fiber-degrading enzyme kinetics by inoculating pig fecal microbiota in vitro. Our results showed that fermentation of arabinoxylan and β-glucan produced the highest amount of acetate and lactate, respectively. The abundance of Prevotella_9 was the highest in β-glucan group and positively correlated with lactate and acetate. Glucomannan fermentation produced the highest amount of butyrate, and the abundance of Lachnospiraceae_XPB_1014_group and Bacteroides were the lowest. A significant negative correlation was found between Lachnospiraceae_XPB_1014_group, Bacteroides and butyrate. Exo-β-1,4-xylanase had the highest activity at 24 h during arabinoxylan fermentation. The activity of β-glucosidase and β-mannosidase at 36 h were higher than those at 15 h in the glucomannan group. The abundance of Prevotella_9 was positively correlated with β-glucosidase while Lachnospiraceae_XPB_1014_group and Bacteroides were negatively correlated with β-xylosidase. Our findings demonstrated the β-glucan and arabinoxylan promote proliferation of Prevotella_9, with the preference to secret β-glucosidase, β-mannosidase and the potential to produce lactate and acetate. Butyrate production can be improved by inhibiting the proliferation of Lachnospiraceae_XPB_1014_group and Bacteroides, which have the lack of potential to secret β-xylosidase.
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Sugiu, Kenji, Toshinari Meguro, Hiroyuki Nakashiama, and Takashi Ohmoto. "Successful Embolization of a Spinal Perimedullary Arteriovenous Fistula with Cellulose Acetate Polymer Solution: Technical Case Report." Neurosurgery 49, no. 5 (November 1, 2001): 1257–61. http://dx.doi.org/10.1097/00006123-200111000-00046.
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ABSTRACT OBJECTIVE AND IMPORTANCE Spinal perimedullary arteriovenous fistulae are rarely reported in the literature and can be treated via both endovascular and direct surgical approaches. Coils, glues, and balloons have all been used to embolize these fistulae. Cellulose acetate polymer (CAP) solution is a liquid embolic material that was originally developed for thrombosis of cerebral aneurysms. This is the first report of CAP solution being used to treat a spinal perimedullary arteriovenous fistula, with changes in the viscosity of the solution. CLINICAL PRESENTATION A 15-year-old boy experienced spinal subarachnoid hemorrhage without any neurological deficits. A radiological examination revealed a spinal perimedullary arteriovenous fistula (Type 2) at the L1 level. INTERVENTION Transarterial embolization was performed with local anesthesia. The microcatheter was navigated through the anterior spinal artery to a site just proximal to the fistula. After provocative testing demonstrated negative results, CAP solution was injected and the fistula was completely closed, without complications. The patient experienced an uneventful postoperative course. CONCLUSION We describe the usefulness of CAP solution in the treatment of a spinal perimedullary arteriovenous fistula. This procedure must be performed for a larger series of patients for assessment of its long-term results.
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Gabryś, Tobiasz Maksymilian, Beata Fryczkowska, Alicja Machnicka, and Tadeusz Graczyk. "Nanocomposite Cellulose Fibres Doped with Graphene Oxide and Their Biocidal Properties." Polymers 13, no. 2 (January 8, 2021): 204. http://dx.doi.org/10.3390/polym13020204.
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The paper presents a method of obtaining composite cellulose fibres (CEL) doped with graphene oxide (GO) and the influence of GO nanoparticles on the structure and properties of the obtained fibres. Composite fibres (GO/CEL) were prepared using wet method from 5% CEL solutions in 1-ethyl-3-methylimidazolium acetate (EMIMAc) containing GO (0; 0.21; 0.50; 0.98; 1.97% w/w) dispersion in N,N-dimethylformamide (DMF). The fibres were coagulated in distilled water and methanol. Optical microscopy allowed us to demonstrate a good degree of GO additive dispersion in the CEL matrix. Surface morphology was examined by scanning electron microscopy (SEM) and infrared spectroscopy (FTIR), which indicated interactions between the matrix and the additive. Strength tests have shown that GO/CEL fibres are characterised by high values of elongation at break (7.7–19.5%) and tenacity (~133–287 [MPa]). The obtained composite fibres are characterized by good biocidal properties against Gram-negative bacteria (Escherichia coli), Gram-positive bacteria (Staphilococcus aureus), and fungi Candida albicans, and the resistance to microorganisms depends on the surface zeta potential value and the isoelectric point (IEP) of GO/CEL fibres.
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Gabryś, Tobiasz Maksymilian, Beata Fryczkowska, Alicja Machnicka, and Tadeusz Graczyk. "Nanocomposite Cellulose Fibres Doped with Graphene Oxide and Their Biocidal Properties." Polymers 13, no. 2 (January 8, 2021): 204. http://dx.doi.org/10.3390/polym13020204.
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The paper presents a method of obtaining composite cellulose fibres (CEL) doped with graphene oxide (GO) and the influence of GO nanoparticles on the structure and properties of the obtained fibres. Composite fibres (GO/CEL) were prepared using wet method from 5% CEL solutions in 1-ethyl-3-methylimidazolium acetate (EMIMAc) containing GO (0; 0.21; 0.50; 0.98; 1.97% w/w) dispersion in N,N-dimethylformamide (DMF). The fibres were coagulated in distilled water and methanol. Optical microscopy allowed us to demonstrate a good degree of GO additive dispersion in the CEL matrix. Surface morphology was examined by scanning electron microscopy (SEM) and infrared spectroscopy (FTIR), which indicated interactions between the matrix and the additive. Strength tests have shown that GO/CEL fibres are characterised by high values of elongation at break (7.7–19.5%) and tenacity (~133–287 [MPa]). The obtained composite fibres are characterized by good biocidal properties against Gram-negative bacteria (Escherichia coli), Gram-positive bacteria (Staphilococcus aureus), and fungi Candida albicans, and the resistance to microorganisms depends on the surface zeta potential value and the isoelectric point (IEP) of GO/CEL fibres.
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Liss, S. N., D. Brewer, A. Taylor, and G. A. Jones. "Antibiotic activity of an isocyanide metabolite of Trichoderma hamatum against rumen bacteria." Canadian Journal of Microbiology 31, no. 9 (September 1, 1985): 767–72. http://dx.doi.org/10.1139/m85-144.
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A metabolite of Trichoderma hamatum, 3-(3-isocyanocyclopent-2-enylidene)propionic acid, was tested for its effects on growth of and carbohydrate metabolism in 11 strains of functionally important rumen bacteria. To standardize the biological activity of this unstable metabolite, a rapid, aerobic disc diffusion assay was developed using Escherichia coli ATCC 11775. In an anaerobic broth dilution assay using a medium lacking rumen fluid and containing a soluble carbohydrate, the minimum inhibitory concentration of the metabolite which completely inhibited growth of the rumen bacteria for 18 h at 39 °C was generally < 10 μg∙mL−1; however, the minimum inhibitory concentrations for Megasphaera elsdenii B159 and Streptococcus bovis Pe18 were 10–25 and 25–64 μg∙mL−1, respectively. In general, the Gram-negative strains were more sensitive than the Gram positive. The minimum inhibitory concentration for Bacteroides ruminicola 23 grown with glucose was 1 μg∙mL−1; for B. ruminicola GA33 (glucose), B. succinogenes S85 (cellobiose), and Succinivibrio dextrinosolvens 24 (maltose), it was 2 μg∙mL−1. When added to a cellulose-containing rumen fluid medium, 1–4 μg∙mL−1 of the metabolite delayed cellulose hydrolysis by B. succinogenes S85, Ruminococcus albus 7, and R. flavefaciens FD1 for up to 4 days, and 6–7 μg∙mL−1 prevented hydrolysis for at least 1 month. In the presence of the metabolite, the proportion of acetate produced from soluble carbohydrate by the majority of strains increased, but with some strains net production of acetate decreased relative to production of other acidic fermentation products. If the metabolite gained entrance to the rumen, a concentration of as little as 1 μg∙mL−1 would probably cause a significant depression of the fermentation and result in nutritional deprivation of the animal.
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Rezakazemi, Mashallah, Alireza Hemmati, and Saeed Shirazian. "Cellulose Acetate Polymeric Membrane Fabrication by Nonsolvent-Induced Phase Separation Process: Determination of Velocities of Individual Components." Journal of Non-Equilibrium Thermodynamics 44, no. 1 (January 28, 2019): 71–80. http://dx.doi.org/10.1515/jnet-2018-0042.
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Abstract In this work, the velocities of individual components during the immersion process using mathematical modeling of a nonsolvent-induced phase separation process are investigated. For this purpose, a mass average velocity correction factor was defined as the ratio of mass average velocity in the absence of a zero polymer velocity assumption to the mass average velocity with zero polymer velocity assumption. The velocities were computed and the result was coherent with observations of a considered case study. It was concluded that the polymer moves towards the interface, as the sign of the polymer velocity at early moments of immersion was positive, which is in accord with accumulation and vitrification of the polymer at the interface. The positive sign of the solvent and the negative sign of nonsolvent are in accord with the observations as solvent leaves the cast film and nonsolvent penetrates into the film. The reduction of velocity values to the order of magnitude of diffusivities is in accord with the limiting role of the rigid skin layer for mass exchanges. Relatively large velocity values of the solvent rather than the nonsolvent imply that much more solvent is probably left in the cast film rather than the nonsolvent enters into it as observed by densification of the cast film.
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Panteghini, M., and F. Pagani. "Diagnostic value of measuring pancreatic lipase and the P3 isoform of the pancreatic amylase isoenzyme in serum of hospitalized hyperamylasemic patients." Clinical Chemistry 35, no. 3 (March 1, 1989): 417–21. http://dx.doi.org/10.1093/clinchem/35.3.417.
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Abstract We assayed amylase (AMY) isoenzymes by cellulose acetate electrophoresis and determined pancreatic lipase (LPS) activity by a turbidimetric colipase-supplemented method in 54 hospitalized hyperamylasemic patients (32 men and 22 women; mean age 61.5, SD 16, years). In AMY isoenzyme analysis, use of a value for P3 isoform greater than 14 U/L as a positive test for acute pancreatitis gave a diagnostic efficiency of 92.6%, a predictive value of a positive test result of 90.5%, and a predictive value of a negative test of 100%. Four of 12 patients with other, nonpancreatic abdominal diseases had false-positive test results. LPS activity (cutoff limit, 700 U/L) was as effective as P3 isoform in distinguishing patients with acute pancreatitis (sensitivity, 100%) from those without acute pancreatitis (specificity, 81.3%). Thus, P3 isoform and LPS appear to be interchangeable markers of pathological release of pancreatic enzymes into the bloodstream during acute pancreatitis. This finding decreases the need for the expensive radiological procedures currently required to confirm this diagnosis. In particular, negative results virtually exclude acute pancreatitis.
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O'Malley, Paula, and Ciaran McDonnell. "Negative pressure wound therapy—two novel approaches to healing dehisced vascular bypass wounds." Journal of Wound Care 30, no. 6 (June 2, 2021): 449–53. http://dx.doi.org/10.12968/jowc.2021.30.6.449.
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The use of negative pressure wound therapy (NPWT) in surgical wound healing by secondary intention is well known. Its use in healing dehisced vascular bypass wounds is contraindicated by manufacturers due to exposed vasculature and risk of bleeding. There is an increasing body of knowledge to support the use of NPWT in vascular wounds in order to prevent graft excision and the need for flap closure. This paper reports the use of two different approaches using NPWT to heal dehisced, infected vascular groin bypass wounds in two patients. Both patients had lower limb bypass using Dacron (Vascutek Ltd., UK) grafts and subsequently became infected, dehisced and required debridement. Following debridement, graft was visible in the wound bed and NPWT was applied to facilitate healing. Case one had polyurethane (black) foam and a layer of petroleum-impregnated cellulose acetate mesh to prevent adherence to the graft. Case two had polyvinyl alcohol (white) (PVA) foam applied to the wound. The PVA foam was used in Case two due to pain at dressing changes. Negative pressure was initially –25mmHg but increased gradually to –125mmHg and –150mmHg, respectively, the therapeutic pressure for the respective foams. Dressings were changed every 48–72 hours and infection treated with antibiotics as appropriate. After eight days and 28 days of NPWT, respectively, graft was no longer visible. No significant bleeding was noted. These two case studies would suggest that, with precautions taken to protect the vasculature, the use of NPWT in healing dehisced vascular groin wounds is an appropriate treatment.
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Kodama, Yumiko, and Kazuya Watanabe. "Rhizomicrobium electricum sp. nov., a facultatively anaerobic, fermentative, prosthecate bacterium isolated from a cellulose-fed microbial fuel cell." International Journal of Systematic and Evolutionary Microbiology 61, no. 8 (August 1, 2011): 1781–85. http://dx.doi.org/10.1099/ijs.0.023580-0.
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A facultatively anaerobic, prosthecate bacterium, strain Mfc52T, was isolated from a microbial fuel cell inoculated with soil and fed with cellulose as the sole fuel. Cells were Gram-negative, non-spore-forming, straight or slightly curved rods, and some of them had one or two polar prosthecae (stalks). Cells reproduced by binary fission or by budding from mother cells having prosthecae. Strain Mfc52T fermented various sugars and produced lactate, acetate and fumarate. Ferric iron, nitrate, oxygen and fumarate served as electron acceptors, while sulfate and malate did not. Nitrate was reduced to nitrite. The DNA G+C content was 64.7 mol%. On the basis of 16S rRNA gene sequence phylogeny, strain Mfc52T was affiliated with the genus Rhizomicrobium in the class Alphaproteobacteria and most closely related to Rhizomicrobium palustre with a sequence similarity of 97 %. Based on these physiological and phylogenetic characteristics, the name Rhizomicrobium electricum sp. nov. is proposed; the type strain is Mfc52T ( = JCM 15089T = KCTC 5806T).
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Tripathi, Shital A., Daniel G. Olson, D. Aaron Argyros, Bethany B. Miller, Trisha F. Barrett, Daniel M. Murphy, Jesse D. McCool, et al. "Development of pyrF-Based Genetic System for Targeted Gene Deletion in Clostridium thermocellum and Creation of a pta Mutant." Applied and Environmental Microbiology 76, no. 19 (August 6, 2010): 6591–99. http://dx.doi.org/10.1128/aem.01484-10.
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ABSTRACT We report development of a genetic system for making targeted gene knockouts in Clostridium thermocellum, a thermophilic anaerobic bacterium that rapidly solubilizes cellulose. A toxic uracil analog, 5-fluoroorotic acid (5-FOA), was used to select for deletion of the pyrF gene. The ΔpyrF strain is a uracil auxotroph that could be restored to a prototroph via ectopic expression of pyrF from a plasmid, providing a positive genetic selection. Furthermore, 5-FOA was used to select against plasmid-expressed pyrF, creating a negative selection for plasmid loss. This technology was used to delete a gene involved in organic acid production, namely pta, which encodes the enzyme phosphotransacetylase. The C. thermocellum Δpta strain did not produce acetate. These results are the first examples of targeted homologous recombination and metabolic engineering in C. thermocellum, a microbe that holds an exciting and promising future in the biofuel industry and development of sustainable energy resources.
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Panpanit, S., C. Visvanathan, and S. Muttamara. "Separation of oil–water emulsion from car washes." Water Science and Technology 41, no. 10-11 (May 1, 2000): 109–16. http://dx.doi.org/10.2166/wst.2000.0620.
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The potentials of UF and NF membrane processes have been evaluated for separation of oil water emulsion generated from car washing operations. Using membranes, wastewater can be effectively recycled and fresh water usage could be reduced. The parameters studied were membrane type, emulsifier types, pressure and competing compounds. Both an-ionic and non-ionic emulsifiers were used for the experimental runs. The Ca2+ and Mg2+ were used as the main competitive ions. Results indicate that a polysulfone membrane caused more flux reduction than the cellulose acetate and thin film polyamide membranes. Higher concentrations of emulsifier presented negative flux decline in both UF and NF membranes. However, the presence of nonionic emulsifier in oil emulsion caused more significant flux reduction than an anionic emulsifier. The NF membrane produced higher TOC removal and less fouling than UF. The results indicate that increased competitive Ca2+ and Mg2+ ions resulted in significant positive NF flux and TOC removal.
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CUI, J. H., H. J. YANG, C. Q. YU, S. BAI, S. S. SONG, T. T. WU, W. SUN, X. M. SHAO, and L. S. JIANG. "Effect of urea fertilization on biomass yield, chemical composition,in vitrorumen digestibility and fermentation characteristics of forage oat straw in Tibet of China." Journal of Agricultural Science 154, no. 5 (March 18, 2016): 914–27. http://dx.doi.org/10.1017/s0021859616000198.
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SUMMARYThe present study investigated the effects of different levels of urea nitrogen (N) fertilizer on nutrient accumulation,in vitrorumen gas production and fermentation characteristics of forage oat straw (FOS) from oats (Avena sativaL. ‘Qinghai 444’) grown in the Tibet region of China. Fertilizer, applied at seeding (day 1), stem elongation (days 52–54) and heading (days 63–67), increased plant height and prolonged the maturity stage of the plant by 4–11 days compared with the non-fertilized control. Oat plants were harvested at maturity at the node 3–4 cm above ground, and then separated into grains and FOS. Both FOS and grain yields increased quadratically with increasing N fertilization, and their theoretical maximums occurred at the N fertilizing rates of 439 and 385 kg/ha, respectively. Increases in N fertilization did not affect the hemicellulose content of FOS, but substantially promoted the accumulation of crude protein, cellulose and lignin, resulting in a decrease in the energy content available for metabolism. A 72-h incubation of FOS with rumen fluids from lactating cows showed that increasing N resulted in FOS that showed a slower fermentation rate, decreasedin vitrodry matter disappearance and lower cumulative gas production, but unchanged fermentation gas composition. Nitrogen fertilization increased the final pH in culture fluids and decreased the microbial volatile fatty acid (VFA) production. The molar proportions of acetate and propionate were not affected, but molar propionate proportion decreased linearly with increasing urea fertilization, and consequently, the ratio of lipogenic (e.g., acetate and butyrate)-to-glucogenic acids (propionate) tended to increase. In brief, increasing urea N fertilization promoted the growth of forage oats and increased the biomass yield as well as the crude protein and cellulose content of FOS. Considering the negative effect of increased lignin content on nutrient digestibility and total VFA production, the suggested range of urea N fertilization is 156–363 kg N/ha for forage oats planted in Tibet to retain the nutritive value of FOS in the rumen.
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Felgueiras, Helena P., Natália C. Homem, Ana R. M. Ribeiro, Marta O. Teixeira, Marta A. Teixeira, Joana C. Antunes, and Maria Teresa P. Amorim. "Activity of Wet-Spun Fibers Chemically Modified with Active Biomolecules against Gram-Positive and Gram-Negative Bacteria." Materials Proceedings 4, no. 1 (November 11, 2020): 85. http://dx.doi.org/10.3390/iocn2020-07935.
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Essential oils (EOs), which are complex biomolecules composed of volatile compounds, have emerged as a new strategy to deal with bacterial infections and as a valid alternative to synthetic drugs. Here, we report the production and modification of wet-spun microfibers made of cellulose acetate (CA) and polycaprolactone (PCL) with the EOs cinnamon leaf oil (CLO), cajeput oil (CJO), and clove oil (CO). These were selected from a group of 20 EOs according to their minimal inhibitory concentration (MIC) against Staphylococcus aureus (<22.4 mg/mL) and Escherichia coli (<11.2 mg/mL) bacteria. Microfibers were produced by wet-spinning at an extrusion rate of 0.5 mL/h directly into an ethanol coagulation bath. EOs loading was accomplished by immersion in ethanol solutions containing the EOs at 2xMIC. Incorporation was confirmed by UV-Visible spectroscopy and Fourier-transformed infrared spectroscopy. After 72 h of incubation, microfibers contained 14%, 66% and 76% of the MIC values of CLO, CO and CJO, respectively. Unloaded and loaded microfibers were characterized as uniform and homogeneous; no significant differences were detected. EO-modified microfibers were effective against the tested bacteria. Considering the amount immobilized, CLO-containing fibers were deemed the most effective from the group, suggesting a superior affinity of the EOs active groups towards the CA/PCL matrix. These results indicate that CA/PCL microfibers loaded with EOs have potential for biomedical application in which infection control is the target.
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Segala, Karen, Silvia Vaz Guerra Nista, Lívia Cordi, Maria Trindade Marques Bizarria, José de Ávila Júnior, Sirlene Adriana Kleinubing, Deborah Cristina Cruz, et al. "Silver nanoparticles incorporated into nanostructured biopolymer membranes produced by electrospinning: a study of antimicrobial activity." Brazilian Journal of Pharmaceutical Sciences 51, no. 4 (December 2015): 911–21. http://dx.doi.org/10.1590/s1984-82502015000400017.
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abstract This study examines the antimicrobial activity of silver nanoparticles incorporated into nanostructured membranes made of cellulose acetate (CA) and blends of chitosan/poly-(ethylene oxide, CTS/PEO) and prepared by electrospinning. The formation of chemically synthesized Ag nanoparticles (AgNPs) was monitored by UV-visible spectroscopy (UV-Vis) and characterized by transmission electron microscopy (TEM). The size distribution of the AgNPs was measured by dynamic light scattering (DLS), with an average size of approximately 20 nm. The presence of AgNPs on the surface of electrospun nanofibers was observed by field emission electron microscopy (FEG) and confirmed by TEM. The antimicrobial activity of AgNPs incorporated into nanostructured membranes made of CA and CTS/PEO electrospun nanofibers was evaluated in the presence of both Gram-positive bacteria, such as Staphylococcus aureus ATCC 29213 and Propionibacterium acnes ATCC 6919, and Gram-negative bacteria, such as Escherichia coli ATCC 25992 and Pseudomonas aeruginosa ATCC 17933. Microbiological results showed that the presence of AgNPs in CA and CTS/PEO nanostructured membranes has significant antimicrobial activity for the Gram-positive bacteria Escherichia coli and Propionibacterium acnes.
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Batt, Kathryn J., and Lois A. Kotkoskie. "An Evaluation of Genotoxicity Tests With Aquateric® Aqueous Enteric Coating." International Journal of Toxicology 18, no. 2 (March 1999): 117–22. http://dx.doi.org/10.1080/109158199225684.
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The genotoxic potential of Aquateric® Aqueous Enteric Coating was evaluated in the Ames test, the mouse lymphoma mutation assay, and the mouse micronucleus test. Aquateric was not mu-tagenic when tested in Salmonella typhimurium cell strains TA98, TA100, TA1535, TA1537, TA1538, with or without metabolic activation. A mouse lymphoma assay was conducted at concentrations ranging from 116 to 2000 μg/ml and 116 to 1250 μg/ml in the absence and presence of metabolic activation, respectively. No increased mutant frequencies were noted for any concentration tested. Aquateric was tested in the mouse micronucleus assay at a single oral dose of 7200 mg/kg Aquateric (equivalent to 5000 mg/kg cellulose acetate phthalate, the major ingredient) and bone marrow was harvested at 24, 48, and 72 hours after treatment. There was no significant increase in the number of mouse bone marrow mi-cronucleated polychromatic erythrocytes in Aquateric-treated animals at any of the harvest times. Based on the negative results in the Ames test, the mouse lymphoma mutation assay, and the mouse micronucleus test, it was concluded that Aquateric is not genotoxic.
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Abdl-Rahman, M. A., F. A. R. Sawiress, and A. M. Abd El-Aty. "Effect of Sodium Lauryl Sulfate-Fumaric Acid Coupled Addition on theIn VitroRumen Fermentation with Special Regard to Methanogenesis." Veterinary Medicine International 2010 (2010): 1–7. http://dx.doi.org/10.4061/2010/858474.
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The aim of the current study was to evaluate the effect of sodium lauryl sulfate-fumaric acid coupled addition onin vitromethangenesis and rumen fermentation. Evaluation was carried out usingin vitrogas production technique. Ruminal contents were collected from five steers immediately after slaughtering and used for preparation of inoculums of mixed rumen microorganisms. Rumen fluid was then mixed with the basal diet of steers and used to generate four treatments, negative control (no additives), sodium lauryl sulfate (SLS) treated, fumaric acid treated, and SLS-fumaric acid coupled addition treated. The results revealed that, relative to control, efficiency in reduction of methanogenesis was as follows: coupled addition > SLS-addition > fumaric acid addition. Both SLS-addition and SLS-fumaric acid coupled addition demonstrated a decremental effect on ammonia nitrogen (–), total short chain volatile fatty acids (SCVFAs) concentrations and the amount of substrate degraded, and an increment effect on microbial mass and microbial yield (). Nevertheless, fumaric acid did not alter any of the previously mentioned parameters but induced a decremental effect on –. Furthermore, both fumaric acid and SLS-fumaric acid coupled addition increased propionate at the expense of acetate and butyrate, while, defaunation increased acetate at the expense of propionate and butyrate. The pH value was decreased by all treatments relative to control, while, cellulase activity did not differ by different treatments. The current study can be promising strategies for suppressing ruminal methane emissions and improving ruminants feed efficiency.
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Reynolds, Robert A., Chad A. Mirkin, and Robert L. Letsinger. "A gold nanoparticle/latex microsphere-based colorimetric oligonucleotide detection method." Pure and Applied Chemistry 72, no. 1-2 (January 1, 2000): 229–35. http://dx.doi.org/10.1351/pac200072010229.
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An exceptionally simple and effective DNA detection methodology based on latex microsphere and gold nanoparticle probes has been developed. The latex and gold particle probes, which were functionalized with separate oligonucleotide sequences, undergo hybridization in the presence of target strands that are complementary to both of the probes. Duplex formation thus results in linking of gold nanoparticles to the latex microspheres and a corresponding white-to-red color change, which, because of the particularly large extinction coefficient of the gold nanoparticles, is clearly visible to the naked eye. Background signal caused by unbound gold nanoparticles is significantly reduced by filtering the solution containing the sample and probes through a size-selective cellulose acetate membrane. The unbound gold probes move freely through this membrane while the larger latex particles are trapped. Therefore, if the latex and gold nanoparticles are joined together via the target oligonucleotides, the membrane appears red, indicating a positive test result. If no hybridization takes place, the membrane appears white, indicating a negative result. The lower detection limits for this system are 500 pM for a 24 base single-stranded target and 2.5 nM for a duplex target oligonucleotide.
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Jackson, John, Claudia Dietrich, Ali Shademani, and Adriana Manso. "The Manufacture and Characterization of Silver Diammine Fluoride and Silver Salt Crosslinked Nanocrystalline Cellulose Films as Novel Antibacterial Materials." Gels 7, no. 3 (July 27, 2021): 104. http://dx.doi.org/10.3390/gels7030104.
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There is an unmet need for biocompatible, anti-infective, and mechanically strong hydrogels. This study investigated the use of poly vinyl alcohol (PVA), polysaccharides, and nanocrystalline cellulose (CNC) to deliver silver in a controlled manner for possible use against oral or wound bacteria. Silver was included in solvent cast films as silver diammine fluoride (SDF) or as nitrate, sulphate, or acetate salts. Hydrogel formation was assessed by swelling determinations and silver release was measured using inductively coupled plasma methods. Antibacterial studies were performed using Gram-positive and negative bacteria turbidity assays. PVA formed homogenous, strong films with SDF and swelled gently (99% hydrolyzed) or vigorously with dissolution (88% hydrolyzed) and released silver slowly or quickly, respectively. CNC-SDF films swelled over a week and formed robust hydrogels whereas CNC alone (no silver) disintegrated after two days. SDF loaded CNC films released silver slowly over 9 days whereas films crosslinked with silver salts were less robust and swelled and released silver more quickly. All silver loaded films showed good antibacterial activity. CNC may be crosslinked with silver in the form of SDF (or any soluble silver salt) to form a robust hydrogel suitable for dental use such as for exposed periodontal debridement areas.
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Cole, Jessica K., Brandon A. Gieler, Devon L. Heisler, Maryknoll M. Palisoc, Amanda J. Williams, Alice C. Dohnalkova, Hong Ming, et al. "Kallotenue papyrolyticum gen. nov., sp. nov., a cellulolytic and filamentous thermophile that represents a novel lineage (Kallotenuales ord. nov., Kallotenuaceae fam. nov.) within the class Chloroflexia." International Journal of Systematic and Evolutionary Microbiology 63, Pt_12 (December 1, 2013): 4675–82. http://dx.doi.org/10.1099/ijs.0.053348-0.
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Several closely related, thermophilic and cellulolytic bacterial strains, designated JKG1T, JKG2, JKG3, JKG4 and JKG5, were isolated from a cellulolytic enrichment (corn stover) incubated in the water column of Great Boiling Spring, NV. Strain JKG1T had cells of diameter 0.7–0.9 µm and length ~2.0 µm that formed non-branched, multicellular filaments reaching >300 µm. Spores were not formed and dense liquid cultures were red. The temperature range for growth was 45–65 °C, with an optimum of 55 °C. The pH range for growth was pH 5.6–9.0, with an optimum of pH 7.5. JKG1T grew as an aerobic heterotroph, utilizing glucose, sucrose, xylose, arabinose, cellobiose, CM-cellulose, filter paper, microcrystalline cellulose, xylan, starch, Casamino acids, tryptone, peptone, yeast extract, acetate, citrate, lactate, pyruvate and glycerol as sole carbon sources, and was not observed to photosynthesize. The cells stained Gram-negative. Phylogenetic analysis using 16S rRNA gene sequences placed the new isolates in the class Chloroflexia , but distant from other cultivated members, with the highest sequence identity of 82.5 % to Roseiflexus castenholzii . The major quinone was menaquinone-9; no ubiquinones were detected. The major cellular fatty acids (>5 %) were C18 : 0, anteiso-C17 : 0, iso-C18 : 0, iso-C17 : 0, C16 : 0, iso-C16 : 0 and C17 : 0. The peptidoglycan amino acids were alanine, ornithine, glutamic acid, serine and asparagine. Whole-cell sugars included mannose, rhamnose, glucose, galactose, ribose, arabinose and xylose. Morphological, phylogenetic and chemotaxonomic results suggest that JKG1T is representative of a new lineage within the class Chloroflexia , which we propose to designate Kallotenue papyrolyticum gen. nov., sp. nov., Kallotenuaceae fam. nov., Kallotenuales ord. nov. The type strain of Kallotenue papyrolyticum gen. nov., sp. nov. is JKG1T ( = DSM 26889T = JCM 19132T).
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Yokoyama, Hiroshi, Isaac D. Wagner, and Juergen Wiegel. "Caldicoprobacter oshimai gen. nov., sp. nov., an anaerobic, xylanolytic, extremely thermophilic bacterium isolated from sheep faeces, and proposal of Caldicoprobacteraceae fam. nov." International Journal of Systematic and Evolutionary Microbiology 60, no. 1 (January 1, 2010): 67–71. http://dx.doi.org/10.1099/ijs.0.011379-0.
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An obligately anaerobic, xylanolytic, extremely thermophilic bacterium, strain JW/HY-331T, was isolated from sheep faeces collected from a farm at the University of Georgia, USA. Cells of strain JW/HY-331T stained Gram-positive and were catalase-negative, non-motile rods. Single terminal endospores (0.4–0.6 μm in diameter) swelled the mother cell. Growth ranges were 44–77 °C (optimum 70 °C at pH70 °C 7.2) and pH70 °C 5.9–8.6 (optimum 7.2 at 70 °C). Salt tolerance was 0–2.0 % (w/v) NaCl. No growth was observed at or below 42 °C or at or above 79 °C or at pH70 °C 5.7 and below or 8.9 and above. In the presence of 0.3 % yeast extract and 0.1 % tryptone, strain JW/HY-331T utilized xylose, glucose, galactose, cellobiose, raffinose and xylan as carbon and energy sources, but not dextran, soluble potato starch, CM-cellulose, cellulose powder, casein or Casamino acids. Fermentation products from glucose were lactate, acetate, ethanol, CO2 and H2. The G+C content of the genomic DNA was 45.4 mol% (HPLC). Major cellular fatty acids were iso-C17 : 0, iso-C15 : 0 and anteiso-C17 : 0. No respiratory quinones were detected. The cell-wall structure was a single layer (Gram-type positive) of the peptidoglycan type A1γ; the cell-wall sugars were galactose and mannose. Based on 16S rRNA gene sequence analysis, ‘Catabacter hongkongensis’ HKU16 (85.4 % similarity), Caloramator fervidus ATCC 43204T (84.2 %) and Caloranaerobacter azorensis MV1087T (83.4 %) were the closest relatives, but they were only distantly related to strain JW/HY-331T. On the basis of physiological, chemotaxonomic and phylogenetic data, isolate JW/HY-331T (=DSM 21659T =ATCC BAA-1711T) is proposed as the type strain of Caldicoprobacter oshimai gen. nov., sp. nov., placed in Caldicoprobacteraceae fam. nov. within the order Clostridiales of the phylum Firmicutes.
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Felgueiras, Helena P., Natália C. Homem, Marta A. Teixeira, Ana R. M. Ribeiro, Joana C. Antunes, and Maria Teresa P. Amorim. "Physical, Thermal, and Antibacterial Effects of Active Essential Oils with Potential for Biomedical Applications Loaded onto Cellulose Acetate/Polycaprolactone Wet-Spun Microfibers." Biomolecules 10, no. 8 (July 31, 2020): 1129. http://dx.doi.org/10.3390/biom10081129.
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New approaches to deal with the growing concern associated with antibiotic-resistant bacteria are emerging daily. Essential oils (EOs) are natural antimicrobial substances with great potential to mitigate this situation. However, their volatile nature, in their liquid-free form, has restricted their generalized application in biomedicine. Here, we propose the use of cellulose acetate (CA)/polycaprolactone (PCL) wet-spun fibers as potential delivery platforms of selected EOs to fight infections caused by Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Twenty EOs were selected and screened for their minimal inhibitory concentration (MIC), using the antibiotic ampicillin as positive control. The cinnamon leaf oil (CLO), cajeput oil (CJO), and the clove oil (CO) were the most effective EOs, against the Gram-positive (MIC < 22.38 mg/mL) and the Gram-negative (MIC < 11.19 mg/mL) bacteria. Uniform microfibers were successfully wet-spun from CA/PCL with an averaged diameter of 53.9 ± 4.5 µm, and then modified by immersion with CLO, CJO and CO at 2 × MIC value. EOs incorporation was confirmed by UV-visible spectroscopy, Fourier-transformed infrared spectroscopy, and thermal gravimetric analysis. However, while microfibers contained ampicillin at MIC (control) after the 72 h modification, the CLO, CO and CJO-loaded fibers registered ≈ 14%, 66%, and 76% of their MIC value, respectively. Data showed that even at small amounts the EO-modified microfibers were effective against the tested bacteria, both by killing bacteria more quickly or by disrupting more easily their cytoplasmic membrane than ampicillin. Considering the amount immobilized, CLO-modified fibers were deemed the most effective from the EOs group. These results indicate that CA/PCL microfibers loaded with EOs can be easily produced with increased antibacterial action, envisioning their use as scaffolding materials for the treatment of infections.
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Vaziri, N. D., J. Wang, T. Cesario, S. Yousefi, R. Valenzuela, and G. Carandang. "Induction, transcription, synthesis, and adsorption of interleukin-1 by dialyzer membranes." Journal of the American Society of Nephrology 4, no. 11 (May 1994): 1884–89. http://dx.doi.org/10.1681/asn.v4111884.
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This study was designed to dissect the direct effect of dialyzer membrane on interleukin-1 (IL-1) induction from those of complement activation, mechanical stimulation, acetate/bicarbonate and endotoxin diffusion, and cell type interactions. To this end, a suspension of P388D1 murine macrophages in a complement-free culture medium containing 10% heat-inactivated serum, a closed-loop system consisting of tubing alone or with a hollow-fiber cuprammonium cellulose (CU) or polyacrylonitrile (PAN) dialyzer, and a roller pump were used. The dialysate compartment was filled with the same medium and capped. Cell suspension was recirculated at 300 mL/min for 3 h. Cells and supernates were separated, and adhering proteins were eluted. All samples tested negative for endotoxin. IL-1 mRNA was greatest with CU, followed by PAN and tubing alone. IL-1 in the supernate was greater with CU than with either tubing alone or PAN (P < 0.005; analysis of variance), which showed comparable values. IL-1 eluted from loops was greatest with PAN dialyzers, followed by sets with CU dialyzers and tubing alone (P < 0.001; analysis of variance). Thus, both CU and PAN membranes directly induce IL-1. However, avid adsorption by PAN attenuates the rise in circulating IL-1.
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Farouk, Asmaa, Shaaban Moussa, Mathias Ulbricht, and Torsten Textor. "ZnO Nanoparticles-Chitosan Composite as Antibacterial Finish for Textiles." International Journal of Carbohydrate Chemistry 2012 (December 12, 2012): 1–8. http://dx.doi.org/10.1155/2012/693629.
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The antibacterial performance of sol-gel-derived inorganic-organic hybrid polymers filled with ZnO nanoparticles-chitosan against a gram-negative bacterium Escherichia coli and a gram-positive Micrococcus luteus has been investigated. Three different molecular weights (MW) of chitosan (CTS) 1.36 · 105, 2.2 · 105, and 3.0 · 105 Da with equal degree of deacetylation (DD, 85%) (coded as S 85-60, He 85-250, and He 85-500) with equal degree of deacetylation (DD, 85%) were examined. ZnO was prepared by the base hydrolysis of zinc acetate in isopropanol using lithium hydroxide (LiOH · H2O) to hydrolyze the precursor. Sol-gel-based inorganic-organic hybrid polymers were modified with these oxides and were applied to cellulosic cotton (100%) and cotton/polyester (65/35%) fabrics. Inorganic-organic hybrids polymers were based on 3-glycidyloxypropyltrimethoxysilane (GPTMS). Bacteriological tests were performed in nutrient agar media on solid agar plates and in liquid broth systems using ZnO nanoparticles with average particle size of (40 nm). Our study showed the enhanced antibacterial activity of ZnO nanoparticles chitosan (different MW) of against a gram-negative bacterium Escherichia coli DSMZ 498 and a gram-positive Micrococcus luteus ATCC 9341 in repeated experiments. The antibacterial activity of textile treated with ZnO nanoparticles chitosan increases with decreasing the molecular weight of chitosan.
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Zhang, Kegui, Lei Song, and Xiuzhu Dong. "Proteiniclasticum ruminis gen. nov., sp. nov., a strictly anaerobic proteolytic bacterium isolated from yak rumen." International Journal of Systematic and Evolutionary Microbiology 60, no. 9 (September 1, 2010): 2221–25. http://dx.doi.org/10.1099/ijs.0.011759-0.
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Two strictly anaerobic, proteolytic bacterial strains, designated strain D3RC-2T and D3RC-3r, were isolated from a cellulose-degrading mixed culture enriched from yak rumen content. The strains were Gram-stain negative and non-spore-forming with cell sizes of 0.5–0.8×0.6–2.0 μm. The temperature range for growth was 24–46 °C (optimum 38–39 °C) and the pH range was between 5.6 and 8.7 (optimum 7.0–7.3). Both strains used soya peptone, tryptone, l-phenylalanine, l-leucine, l-methionine, l-serine, l-valine, l-threonine and l-histidine as carbon and nitrogen sources, but did not use any of the saccharides tested. The major fermentation products from PY medium were acetate, propionate and iso-butyrate. The DNA G+C contents of strains D3RC-2T and D3RC-3r were 41.0±0.1 mol% and 41.3±0.1 mol% (HPLC), respectively. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the two strains represented a new phyletic sublineage within the family Clostridiaceae, with <93.8 % 16S rRNA gene sequence similarity to recognized species. On the basis of the phenotypic, genotypic and physiological evidence, strains D3RC-2T and D3RC-3r are proposed as representing a novel species of a new genus, for which the name Proteiniclasticum ruminis gen. nov., sp. nov. is proposed. The type strain of the type species is D3RC-2T (=AS 1.5057T=JCM 14817T).
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Olatunya, Oladele S., Dulcinea M. Albuquerque, Adeniyi F. Fagbamigbe, Opeyemi A. Faboya, Ayotunde E. Ajibola, Oluwatoyin A. Babalola, Adewale O. Adebisi, Adeyinka G. Falusi, Adekunle Adekile, and Fernando F. Costa. "Diagnostic Accuracy of HemotypeSC as a Point-of-Care Testing Device for Sickle Cell Disease: Findings from a Southwestern State in Nigeria and Implications for Patient Care in Resource-Poor Settings of sub-Saharan Africa." Global Pediatric Health 8 (January 2021): 2333794X2110167. http://dx.doi.org/10.1177/2333794x211016789.
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This study aimed to determine the performance of a rapid, point-of-care testing device (HemotypeSC)™ for diagnosing sickle cell disease (SCD) relative to 2 commonly-used methods compared to DNA polymerase chain reaction (PCR) as the reference standard. The diagnostic performance of (HemotypeSC)™ in diagnosing SCD and determining various other Hb genotypes relative to high performance liquid chromatography (HPLC) and cellulose acetate Hb electrophoresis in alkaline buffer (CAE) was investigated among 156 participants aged 4 to 23 years in Ekiti, Southwest Nigeria. PCR was considered as the reference method/gold standard. The sensitivity and specificity for SS, SC, AS, AC, and AA genotypes by HemotypeSC and HPLC when compared with PCR, were each 100%. Similarly, their positive and negative predictive values were each 100%. However, sensitivity and specificity for identifying these Hb genotypes by CAE were 100, 100, 96.5, 0, 99.2%, and 99, 100, 92.9, 0, 91.7%. Also, CAE did not identify any of the 2 HbAC individuals that were correctly identified by PCR and both HemotypeSC, and HPLC, thus representing 100% HbAC misdiagnosis. In conclusion, this study shows that HemotypeSC has perfect concordance with PCR and 100% accuracy in diagnosing SCD in the population tested. Its ease of use, accuracy and other attributes make it suitable for use in sub-Saharan Africa for rapid determination of Hb genotypes.
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Tomás, Ana Faria, Dimitar Karakashev, and Irini Angelidaki. "Thermoanaerobacter pentosaceus sp. nov., an anaerobic, extremely thermophilic, high ethanol-yielding bacterium isolated from household waste." International Journal of Systematic and Evolutionary Microbiology 63, Pt_7 (July 1, 2013): 2396–404. http://dx.doi.org/10.1099/ijs.0.045211-0.
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An extremely thermophilic, xylanolytic, spore-forming and strictly anaerobic bacterium, strain DTU01T, was isolated from a continuously stirred tank reactor fed with xylose and household waste. Cells stained Gram-negative and were rod-shaped (0.5–2 µm in length). Spores were terminal with a diameter of approximately 0.5 µm. Optimal growth occurred at 70 °C and pH 7, with a maximum growth rate of 0.1 h−1. DNA G+C content was 34.2 mol%. Strain DTU01T could ferment arabinose, cellobiose, fructose, galactose, glucose, lactose, mannitol, mannose, melibiose, pectin, starch, sucrose, xylan, yeast extract and xylose, but not cellulose, Avicel, inositol, inulin, glycerol, rhamnose, acetate, lactate, ethanol, butanol or peptone. Ethanol was the major fermentation product and a maximum yield of 1.39 mol ethanol per mol xylose was achieved when sulfite was added to the cultivation medium. Thiosulfate, but not sulfate, nitrate or nitrite, could be used as electron acceptor. On the basis of 16S rRNA gene sequence similarity, strain DTU01T was shown to be closely related to Thermoanaerobacter mathranii A3T, Thermoanaerobacter italicus Ab9T and Thermoanaerobacter thermocopriae JT3-3T, with 98–99 % similarity. Despite this, the physiological and phylogenetic differences (DNA G+C content, substrate utilization, electron acceptors, phylogenetic distance and isolation site) allow for the proposal of strain DTU01T as a representative of a novel species within the genus Thermoanaerobacter , for which the name Thermoanaerobacter pentosaceus sp. nov. is proposed, with the type strain DTU01T ( = DSM 25963T = KCTC 4529T = VKM B-2752T = CECT 8142T).
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Nakano, Takuo, and Mirko Betti. "Production of sialic acid rich glycopeptide from bovine κ-casein glycomacropeptide by hydrolyzing with papain." Journal of Dairy Research 87, no. 3 (August 2020): 364–67. http://dx.doi.org/10.1017/s0022029920000783.
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AbstractBovine κ-casein glycomacropeptide (GMP) is a sialic acid containing glycopeptide having many biological activities. The study described in this research communication was undertaken to determine whether sialic acid rich glycopeptide can be produced from GMP by proteinase treatment. A sample of GMP was hydrolyzed with papain, and the obtained hydrolysate was chromatographed on a column of diethylaminoethyl-Sephacel to obtain a glycopeptide fraction (GPF). This product accounted for average 48.1% dry weight of GMP or 81.1% total recovered sialic acid from GMP. The content of sialic acid (expressed as % dry weight) was 1.7 times higher in GPF (22.6) than in unhydrolyzed GMP (13.4). Major differences in amino acid composition between GPF and GMP were found in the contents (mol%) of: lysine (<1 and 4.5, respectively), serine (20.3 and 10.3, approximately twice higher in GPF), asparagine/aspartic acid and isoleucine. The contents of the last two amino acids were approximately twice lower in GPF. On gel filtration chromatography with Sephacryl S-100, GMP was eluted as a single peak with elution volume similar to that of dimeric β-lactoglobulin (36.6 kDa) whereas GPF was eluted in two peaks both with elution volumes greater than that of α-lactalbumin (14.2 kDa). These peak fractions containing high (fraction I) and low (fraction II) molecular size glycopeptides gave different sialic acid to peptide ratio, which was 1.7 times higher in fraction I than in fraction II. Results of size exclusion HPLC on Superdex-75 were consistent with those of gel filtlation chromatography. On cellulose acetate electrophoresis, the mobility of GPF relative to that of GMP as 1.0 was found to average 1.2, suggesting a higher negative charge density in GPF than in GMP. It was concluded that papain digestion of GMP is an efficient method to produce glycopeptide with high sialic acid content.
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Bi, Changhao, John D. Rice, and James F. Preston. "Complete Fermentation of Xylose and Methylglucuronoxylose Derived from Methylglucuronoxylan by Enterobacter asburiae Strain JDR-1." Applied and Environmental Microbiology 75, no. 2 (November 14, 2008): 395–404. http://dx.doi.org/10.1128/aem.01941-08.
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ABSTRACT Acid pretreatment is commonly used to release pentoses from the hemicellulose fraction of cellulosic biomass for bioconversion. The predominant pentose in the hemicellulose fraction of hardwoods and crop residues is xylose in the polysaccharide methylglucuronoxylan, in which as many as one in six of the β-1,4-linked xylopyranose residues is substituted with α-1,2-linked 4-O-methylglucuronopyranose. Resistance of the α-1,2-methylglucuronosyl linkages to acid hydrolysis results in release of the aldobiuronate 4-O-methylglucuronoxylose, which is not fermented by bacterial biocatalysts currently used for bioconversion of hemicellulose. Enterobacter asburiae strain JDR-1, isolated from colonized hardwood (sweetgum), efficiently ferments both methylglucuronoxylose and xylose, producing predominantly ethanol and acetate. 13C-nuclear magnetic resonance studies defined the Embden-Meyerhof pathway for metabolism of glucose and the pentose phosphate pathway for xylose metabolism. Rates of substrate utilization, product formation, and molar growth yields indicated methylglucuronoxylose is transported into the cell and hydrolyzed to release methanol, xylose, and hexauronate. Enterobacter asburiae strain JDR-1 is the first microorganism described that ferments methylglucuronoxylose generated along with xylose during the acid-mediated saccharification of hemicellulose. Genetic definition of the methylglucuronoxylose utilization pathway may allow metabolic engineering of established gram-negative bacterial biocatalysts for complete bioconversion of acid hydrolysates of methylglucuronoxylan. Alternatively, Enterobacter asburiae strain JDR-1 may be engineered for the efficient conversion of acid hydrolysates of hemicellulose to biofuels and chemical feedstocks.
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Premraj, N., R. Valcheva, and L. A. Dieleman. "A230 ISOMALTODEXTRIN DOSE-DEPENDENTLY REDUCES COLITIS DEVELOPMENT IN HLA-B27 RAT COLITIS MODEL WITH ASSOCIATED CHANGES TO GUT MICROBIOME COMPOSITION AND SHORT CHAIN FATTY ACID PRODUCTION." Journal of the Canadian Association of Gastroenterology 4, Supplement_1 (March 1, 2021): 275–76. http://dx.doi.org/10.1093/jcag/gwab002.228.
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Abstract Background Inflammatory bowel disease (IBD) is characterized by altered intestinal microbiome (i.e. dysbiosis), described by reduced strict butyrate-producing anaerobes versus increased facultative anaerobes. Data from preclinical studies and clinical trials show prebiotic inulin-type fibers can prevent and reduce colitis. However, other dietary fibers (e.g. resistant starches, RS) are understudied and it is unknown if RS-induced microbial shifts are protective in experimental colitis. Aims Assess efficacy of isomaltodextrin (IMD), a novel RS, to reduce intestinal inflammation in HLA-B27 transgenic (TG) rat colitis model and identify protective mechanisms associated with gut microbial composition and function. Methods 4 week old HLA-B27 TG rats were fed standard chow supplemented with: 7.5% IMD (low dose, LD), 15% IMD (high dose, HD), negative control (15% cellulose, NC), or positive control (15% fructooligosaccharides, PC) for 12 weeks. Body weight and food intake were measured. Cecal and colonic inflammation assessed by weight/length ratio, macroscopic scoring and mucosal IL-1β secretion. Changes in microbial energy metabolism evaluated by measuring short chain fatty acid (SCFA) production in stool and cecal contents. Endpoint fecal and cecal microbiota composition differences assessed by 16S rRNA gene sequencing (Illumina MiSeq platform). Results IMD showed dose-dependent effect on cecal inflammation, measured by macroscopic tissue scoring, weight/length ratio and IL-1β secretion. HD rats had significantly lower cecum IL-1β concentration compared to NC (q=0.01), while LD showed only a trend (q=0.09). HD had significantly higher cecal amounts of Bacteroidaceae and Allobaculum spp. and lower amounts of Peptostreptococcaceae, Eubacterium and Barnesiella spp. versus the LD and NC. HD was associated with significantly higher total SCFA compared to NC (q<0.01) and showed a trend of higher total SCFA than LD (q=0.06). Analysis of SCFAs revealed propionate, isobutyrate and valerate ratios were significantly lower in HD than LD and NC. HD showed a trend of higher ratio of butyrate + acetate compared to NC. This suggests increased carbohydrate fermentation by acetate-producing and -converting microbial groups. Correlation analysis confirmed IL-1β concentrations were positively associated with isobutyrate (r=0.52, q<0.01), valerate (r=0.54, q<0.01), and propionate (r=0.48, q<0.01), suggesting their use as chronic inflammation markers in HLA-B27 models. Conclusions IMD was dose-dependently effective in reducing chronic cecal inflammation in experimental colitis. Benefits were associated with specific shifts in gut microbiome composition and SCFA production. Results from this preclinical study warrant future microbiota-altering intervention trials using IMD in clinical IBD. Funding Agencies Hayashibara Co., Ltd.
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O’Meara, D., Q. Tufail, F. Lim, C. Richards, and A. A. Thi. "P852 Introduction of Entamoeba histolytica serology testing in the management of inflammatory bowel disease patients at University Hospitals of Leicester, UK." Journal of Crohn's and Colitis 14, Supplement_1 (January 2020): S655—S656. http://dx.doi.org/10.1093/ecco-jcc/jjz203.980.
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Abstract Background Amoebic colitis can mimic inflammatory bowel disease (IBD) in clinical presentation, endoscopic and (to some extent) histological findings. Four patients with amoebic colitis were misdiagnosed with IBD or an IBD flare at University Hospitals of Leicester (UHL), UK in 2018. This prompted a change in practise in our department and we began screening for Entamoeba histolytica in patients with newly-diagnosed IBD, a flare or those being considered for biologics. We analysed cases of possible amoebic colitis after this change by reviewing IBD patients with a positive E. histolytica immunofluorescence antibody test (IFAT). Methods We conducted a retrospective electronic and case note review of patients with IBD and positive amoeba IFAT serology >1:80 from April 2019 through September 2019. We collected information including Crohn’s disease (CD), ulcerative colitis (UC), IBD treatment, histological findings, travel history, stool E. histolytica DNA polymerase chain reaction (PCR) and amoebic serology including IFAT and Cellulose Acetate Precipitin test (CAP). The histology of endoscopic biopsies for 16 of the IFAT positive patients was reviewed specifically for amoebic trophozoites. Results During the study period we identified 26 IFAT positive patients, excluded 3 patients that were felt to be non-IBD; 23 were included in the study. The median age was 37.8 (range 16–86); 43.5% were male. Four had a diagnosis of UC; 19 had CD. 12 were new IBD presentations. Seven patients had a relevant travel history (Jamaica, Thailand, Turkey, Italy, Greece, and Spain). Four did not have a travel history. Travel history was unknown for 12. Three patients were on biologics, one on biologics and thiopurines. Five were on thiopurines, three on thiopurines and steroids. Four were on steroids only, four on 5-ASAs. Three were on no treatment. Two out of 16 patients reviewed had amoebic trophozoites on endoscopic biopsy, unfortunately stool PCR was not sent on these two patients. Stool E. histolytica DNA PCR, was sent for 19 patients and was negative in those cases. All 24 patients were negative for CAP. Conclusion While IFAT is helpful in detecting past exposure it is only 75% sensitive for amoebic colitis. Even if IFAT and CAP are combined it is difficult to differentiate amoebic colitis from IBD. It is not clear if these cases represent past infections, early infections that precipitated an IBD flare, early infections that arose in the setting of immunosuppression, or false positive IFATs. The risk of infection in the immunosuppressed patient is high and the consequences of misdiagnosis are significant therefore a comprehensive screening method is merited; this may encompass IFAT ± CAP, stool E. histolytica DNA PCR, and possibly histological review.
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Boricha, Alka G., and Zagabathuni Venkata Panchakshari Murthy. "Dilute solution viscometry study on the miscibility of N,O-carboxymethyl chitosan-cellulose acetate blends." Journal of Polymer Engineering 31, no. 4 (August 1, 2011). http://dx.doi.org/10.1515/polyeng.2011.070.
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Abstract Dilute solution viscometry method is used for studying viscosity behavior of newly prepared N,O-carboxymethyl chitosan (NOCC), cellulose acetate (CA), and their blends at different compositions (0/10, 2/8, 4/6, 5/5, 6/4, 8/2, 10/0). In this method, reduced viscosity (η sp/c) and inherent viscosity (ln η rel/c) of the given polymer sample have been determined by measuring the flow time of the polymer sample in acetone solvent. Huggins (k) and Kraemer coefficients (k′) for given polymer-solvent system are calculated from the extrapolation of plots (η sp/c) versus(c) and (ln η rel/c) versus(c). The miscibility of this polymer system is determined using different criteria such as Δb, Δb′, , interaction parameter Δ[η], thermodynamic parameter α, and modified thermodynamic parameter β. Based on the positive or negative sign of this criteria, miscibility of the polymer system is investigated. The results of the dilute solution viscometry method suggested that the NOCC/CA blends are miscible at the compositions range of 4/6, 5/5, 6/4, and 8/2 and completely immiscible at the 2/8 composition. The results are also supported by Fourier transform infrared analyses of all the compositions.
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Azmi, N. A., Q. H. Ng, A. L. Ahmad, and S. C. Low. "Development of Magnetite Nano–composite Membrane for Membrane Defouling." Journal of Applied Membrane Science & Technology 15, no. 1 (November 22, 2017). http://dx.doi.org/10.11113/amst.v15i1.99.
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This research proposes to untangle the membrane fouling by introducing nanostructured magnetite (Fe3O4) colloids into the polymeric membrane. In present study, nanostructure magnetite nanoparticles (MNPs) were synthesized via co–precipitation method with ammonium hydroxide and sodium hydroxide as the precipitation agents at different pH condition. The synthesized MNPs were functionalized with poly(diallyldimethylammonium chloride) (PDDA) and then spin coated on the surface of the ultrafiltration cellulose acetate (CA) membrane. Intrinsic properties for this nano–composite membrane, in regards to the physical structures, surface negative charge density and the membrane filtration performance, on surface fouling by humic acid solutions were investigated. Experimental results demonstrated that, the nano–composite membrane has significantly reduced the humic acid fouling on the membrane surface. This could be explained by the electrostatic interactions between negatively charged humic acid molecules and the nano–composite membrane. Throughout the study, the results provide some fundamental insights into the physical interactions that governing the membrane fouling during filtration.