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B. askiewicz 《应用聚合物科学杂志》1998,67(11):1871-1876
Based on experiments conducted, it has been found that bacterial cellulose, like spruce cellulose, is soluble in an aqueous NaOH solution with the concentration of 8.5% at a temperature of −5°C if the polymerization degree of the cellulose does not exceed 400. When 1% of urea is added to the NaOH solution, the solubility of cellulose increases; and, in this solvent, bacterial cellulose may be dissolved so long as its polymerization degree is below 560. The results of these experiments are of great practical importance since they point to the possibility of the preparation of cellulose spinning solutions suitable for fiber formation. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:1871–1876, 1998 相似文献
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Silvia A. Villarreal-Soto Jalloul Bouajila Sandra Beaufort Denis Bonneaud Jean-Pierre Souchard Patricia Taillandier 《乙烯基与添加剂工艺杂志》2021,27(1):183-190
The production of bacterial cellulose has been limited due to its high cost and low productivity. Alternative low-cost sources of this biopolymer of high purity and biocompatibility are needed in order to benefit from its enormous potential. Kombucha tea is a trend functional beverage whose production is growing exponentially worldwide, and the bacteria present in this fermented beverage belonging to the genus Komagataeibacter are capable of producing a crystalline biofilm with interesting properties. Obtaining bacterial cellulose from Kombucha tea has already been studied, however several fermentation conditions are being optimized in order to scale-up its production. In this study, we characterized the bacterial cellulose produced from three different Kombucha fermentation conditions. The scanning electron microscopy images revealed the crystalline structure of the biofilms. The energy-dispersive x-ray analysis exhibited the chemical composition of the crystals. The thermogravimetric analysis showed a rate of degradation between 490 and 560°C and the differential scanning calorimetry confirmed the presence of crystalline and amorphous regions in the bacterial cellulose samples. The results suggested that crystalline cellulose could be obtained by varying the fermentation conditions of Kombucha tea. 相似文献
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Chia‐Hung Kuo Po‐Ju Lin Cheng‐Kang Lee 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2010,85(10):1346-1352
BACKGROUND: Waste textiles, such as dyed cellulosic and/or polyester blended fabrics have the potential to serve as an alternative feedstock for the production of biological products via microbial fermentation. Dissolution pretreatment was employed to enhance the enzymatic saccharification of dyed and synthetic fiber blended cellulosic fabrics. The fermentable reducing sugars obtained from waste cellulosic fabrics were used to culture Gluconobacter xylinus for value‐added bacterial cellulose (BC) production. RESULTS: Concentrated phosphoric acid was the ultimate cellulose solvent for dissolution pretreatment since 5% w/w cellulosic fabric can be completed dissolved at 50 °C. After regeneration in water, the cellulosic precipitate was subjected to cellulase hydrolysis, resulting in at least 4‐fold enhancement of saccharification rate and reducing sugars yield. The colored saccharification products can be utilized by G. xylinus to produce BC, approximately 1.8 g L?1 BC pellicle was obtained after 7 days static cultivation. CONCLUSION: Dyed and blended waste fabric can be pretreated effectively by dissolution to produce fermentable sugars by cellulase hydrolysis. Dissolution pretreatment can expose the dyed or polyester fiber covered digestible cellulosic fibers to cellulase and leads to a significant enhancement of saccharification yield. The colored saccharification products have no significant inhibiting effect on the fermentation activity of G. xylinus for BC production. Copyright © 2010 Society of Chemical Industry 相似文献
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Feng Hong Ying Xue Zhu Guang Yang Xue Xia Yang 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2011,86(5):675-680
BACKGROUND: Bacterial cellulose (BC) is an extracellular biopolymer product of vinegar bacteria, which is widely used in many areas. However, problems of high production cost have prevented widescale extension of BC applications. In this work, BC was produced using wheat straw hydrolysates prepared by dilute acid hydrolysis instead of the usual carbon sources, with the aim of decreasing the production costs of BC. RESULTS: In order to remove microbial growth inhibitors, wheat straw hydrolysates were detoxified by treatment with various alkalis including calcium hydroxide, sodium hydroxide and ammonia, and their combination with activated charcoal or laccase. Results showed that the detoxification effect using calcium hydroxide was much better than that with the other alkalis. The BC yield using hydrolysate treated with Ca(OH)2 and activated charcoal was at least 50% higher than that using routine carbon sources. Additionally, the ions of Ca2+ and Na+ in the hydrolysates had important and positive effects on BC production while Cl? exhibited negative effects. CONCLUSION: Wheat straw was shown to be a suitable feedstock for BC production, and a process was established for BC production from lignocellulosic feedstocks using a detoxification treatment. Copyright © 2011 Society of Chemical Industry 相似文献
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细菌纤维素(BC)因其独特性能被广泛应用于医药、食品等领域,目前其高产量菌株筛选、合成成本降低及合成途径改良等成为研究热点。本文依据国内外文献并结合团队研究成果对BC合成与鉴定的相关研究进行综述。首先对BC合成菌筛选及碳源利用的研究进行了分析,总结了降低BC合成成本的研究思路。其次对鉴定菌株合成产物的方法进行了归纳,总结了不同方法的特点。然后结合本团队筛选出的BC生产菌XJL-06-4 BC合成酶基因分析结果,综述了BC合成途径、合成酶存在形式以及基因水平调控作用,为BC在分子水平上通过改变合成途径提高产量提供新思路。最后,总结BC微生物发酵生产存在的问题,多角度提出解决方案。 相似文献
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Leticia Romero‐Cedillo Hector M Poggi‐Varaldo Teresa Ponce‐Noyola Elvira Ríos‐Leal Ana C Ramos‐Valdivia Carlos M Cerda‐García Rojas José Tapia‐Ramírez 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2017,92(5):937-958
The organic fraction of municipal solid waste (OFMSW), mainly composed of lignocellulosic polymers, is extremely complex. Therefore, it is necessary to apply pretreatments to remove the lignin content and decrease the cellulose crystallinity in order to use the OFMSW for gas biofuels production in the context of biorefineries from waste. This work focused on critically reviewing the conventional pretreatments applied to OFMSW, with the goal of improving the H2 production, as well as other biofuels in modern biorefineries. There are a wide variety of pretreatments that have successfully been used, mainly alkaline, milling and dilute acid. In addition, some research has focused on the recovery and reutilization of the alkali, acid or solvents after the pretreatment, to be incorporated into new cycles of production, minimizing the environmental impacts. Moreover, it would be necessary to incorporate analytical tools, in order to determine the sustainability of the biorefinery project. It is concluded that waste pretreatments could significantly contribute to increased yields of biogas fuels in organic waste‐based biorefineries. Therefore, establishing preliminary stages for conditioning biomass or wastes is essential to improve the degradation of wastes and bio‐product generation. © 2016 Society of Chemical Industry 相似文献
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The treatment of various types of oily wastewater is paramount for environmental protection. Bacterial cellulose (BC) stands out as a highly promising material for oil/water separation, owing to its exceptional mechanical properties and three-dimensional porous structures. However, excessive hydroxyl groups on BC make it highly hydrophilic, reducing oil absorption and promoting bacterial growth, affecting its stability. To address these challenges, we developed a straightforward in situ polymerization method for the preparation of BC-DMC composites. The innovation lies in the concurrent enhancement of BC's hydrophobicity and antimicrobial properties only through the addition of 2-(Methacryloyloxy)ethyltrimethylammonium chloride (DMC), considerably simplifying the synthesis of materials possessing oil-absorbing and antimicrobial properties. Morphological and structural characterization results confirmed the successful combination of DMC onto BC while maintaining its porous structure. After process parameter optimization, the BC-DMC composites exhibited a remarkable increase in contact angle (117.7° compared with pure BC's 19.5°). It also demonstrated excellent oil absorption performance, with maximum capacities exceeding 30 g/g for different oils, maintaining values above 20 g/g even after eight cycles. In addition, the BC-DMC composites exhibited strong antibacterial activity, with rates of 82.4% against Escherichia coli and 97.5% against Staphylococcus aureus. The antibacterial mechanism of the BC-DMC composites was also discussed. Our novel BC-DMC composites provides excellent oil absorption and antibacterial properties, making it highly applicable in the field of oily wastewater treatment and serving as a valuable reference for other researchers. 相似文献
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利用木糖驹形氏杆菌发酵生产细菌纤维素(Bacterial Cellulose,BC),利用红外光谱仪、X-射线衍射分析仪、扫描电镜等对BC膜进行表征,并对BC膜作为面膜基材方面的各项性能进行全面评价。结果表明,BC膜具有超细的三维网状结构,平均直径小于100 nm,结晶度83.46%,属于典型的Ⅰ型纤维素。相较于无纺布与蚕丝面膜,BC膜具有更优越的持水性能、水蒸气透过性能(2263.54 g/m2?24 h)以及力学性能。相同面积的BC膜在24 h内对负载维生素C(Vc)Pickering乳液中Vc的吸收量(42.36 ?g/cm2)约为无纺布面膜(19.13 ?g/cm2)的2.21倍,为蚕丝面膜(27.36 ?g/cm2)的1.54倍;在90 min内能向皮肤输送10.96 ?g/cm2的营养物质,约为无纺布面膜(6.08 ?g/cm2)的1.8倍,为蚕丝面膜(5.35 ?g/cm2)的2倍。 相似文献
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As a new advanced oxidation technology, photocatalytic technology has broad application prospects in the field of wastewater treatment. However, in the actual use process, there will be difficulties in catalyst recovery and reuse. This article successfully prepared bacterial cellulose (BC) loaded silver and titanium dioxide nanoparticles (Ag-plated TiO2/BC composite pellicle) by in situ embedding method. BC not only works as the carrier to load TiO2 and Ag NPs but also adsorbs dyes to promote the reaction. As a reusable photocatalytic film, it is convenient to use and recycle in terms of testing and characterization compared with powders. The results show that Ag and TiO2 nanoparticles were closely embedded in BC. We evaluated the photocatalytic degradation performance of the catalyst on methylene blue (MB), active red X-3B, and Rhodamine B. When the reaction time was 2 h, the dye removal rates were 71%, 68%, and 82.6%. At the same time, through the inhibition zone experiment, it was found that the material has a certain inhibitory effect on both Escherichia coli and Staphylococcus aureus. Therefore, the supported catalyst prepared by this method has the advantages of high catalytic activity, relatively stable property, easy recovery, and tailorability, making it potentially applicable in sewage post-treatment links. 相似文献
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Tong‐Qi Yuan Feng Xu Run‐Cang Sun 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2013,88(3):346-352
Lignin, a major component of the cell wall of vascular plants, has long been recognized for its negative impact and treated as a by‐product in a biorefinery. This highly abundant by‐product of the biorefinery is undervalued and underdeveloped due to its complex nature. The development of value‐added products from lignin would greatly improve the economics of the biorefinery. The inherent properties of lignin significantly affect the productivity of the biorefinery processes and its potential applications. Although the structure and biosynthetic pathway of lignin have been studied for more than a century, they have not yet been completely elucidated. In this mini‐review, the primary obstacles to elucidating the structure of native lignin, including separation and characterization, are highlighted. Several classical methods for separation and various NMR techniques, especially 2D HSQC NMR, for characterization of lignin are reviewed. Some potential applications of lignin are introduced. It is believed that a knowledge of the method to separate lignin from the cell wall and structural features of the lignin polymer from lignocellulosic materials will help to maximize the exploitation of lignocelluloses for the biorefinery as well as the utilization of lignin for novel materials and chemicals. © 2012 Society of Chemical Industry 相似文献
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Kinetic and thermodynamic studies of adsorption of Cu2+ and Pb2+ onto amidoximated bacterial cellulose 总被引:1,自引:0,他引:1
Removal of Cu2+ and Pb2+ from aqueous solutions by adsorption onto amidoximated bacterial cellulose (Am-BC) was investigated. The effects of pH, initial
concentration, contact time and temperature were studied in batch experiments. The pseudo-first and pseudo-second orders and
intraparticle diffusion equation were used to evaluate the kinetic data and the constants were determined. The experimental
data fits well to the pseudo-second order kinetic model, which indicates that the chemical adsorption is the rate-determining
step, instead of mass transfer. The equilibrium adsorption data were described by the Langmuir, Freundlich, and Temkin isotherms.
The Am-BC showed a better fit to the Langmuir isotherm. The separation factor (R
L
) revealed the favorable nature of the isotherm. The thermodynamic parameters (ΔH
ads0, ΔS
ads0, ΔG
ads0) for Cu2+ and Pb2+ adsorption onto Am-BC were also determined from the temperature dependence. The values of enthalpy and entropy indicated
that this process was spontaneous and exothermic. The experimental studies indicate that Am-BC would be a potential effective
adsorbent to remove the metal ions from wastewater. 相似文献
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Pineapple agroindustrial residues for the production of high value bacterial cellulose with different morphologies 下载免费PDF全文
Itxaso Algar Susana C. M. Fernandes Gurutz Mondragon Cristina Castro Clara Garcia‐Astrain Nagore Gabilondo Aloña Retegi Arantxa Eceiza 《应用聚合物科学杂志》2015,132(1)
Bacterial cellulose (BC) with different morphologies was biosynthesized by Gluconacetobacter medellinensis strain under static and dynamic culture conditions using sugar cane juice and pineapple residues as sources of carbon and other nutrients. Hestrin and Schramm's standard culture medium was used as reference. The fermentation condition and resulting yield, physico‐chemical properties, and morphology relationships of obtained cellulose were analyzed. Pineapple agroindustrial residues can be envisaged as an inexpensive and sustainable alternative resource for the production of different BC morphologies. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41237. 相似文献
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Amidoximated bacterial cellulose (Am‐BC) was prepared through successive polymer analogous reactions of bacterial cellulose with acrylonitrile in an alkaline medium followed by reaction with aqueous hydroxylamine. It was used as an adsorbent to remove Cu2+ and Pb2+ from aqueous solutions. The adsorption behaviors of Cu2+ and Pb2+ onto Am‐BC were observed to be pH‐dependent. The maximum adsorption capacity of 84 and 67 mg g–1 was observed, respectively, for Cu2+ and Pb2+ at pH 5. Scanning electronic microscopy (SEM) indicated that the microporous network structure of Am‐BC was maintained even after the modifacation. The adsorption mechanisms for Cu2+ and Pb2+ onto Am‐BC were investigated by fourier transform infrared spectroscopy (FTIR), ζ potential measurement and X‐ray photoelectron spectroscopy (XPS). The results revealed that the mechanism for the adsorption of Cu2+ onto Am‐BC could be mainly described as between metal ions and nitrogen atom in the amidoxime groups or oxygen atom in the hydroxyl groups. However, in the adsorption process for Pb2+, precipitation played the important role along with electrostatic interactions, although chelation action also existed in the process accounted for the adsorption process. The regeneration of Am‐BC was studied by treatment with a strong complexing agent, ethylenediaminetetracetic acid (EDTA). © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
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以细菌纤维素为原料,N-甲基吗啉-N-氧化物为溶剂制得纺丝原液,在不同的凝固浴温度条件下,制备再生细菌纤维素纤维,对其形貌、结晶度、取向度、力学性能、吸湿保湿性等进行了研究.结果表明:随着凝固浴温度的提高,再生细菌纤维素纤维表面逐渐趋于光滑,且结晶度提高、取向度和断裂强度降低;凝固浴温度为0~45℃,再生细菌纤维素纤维... 相似文献
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This work demonstrates the synthesis of lactic acid oligomer-grafted-untreated bacterial cellulose (OLLA-g-BC) by in situ condensation polymerization which increased compatibilization between hydrophobic poly(lactic acid) (PLA) and hydrophilic BC, thus enhancing various properties of PLA-based bionanocomposites, indispensable for stringent food-packaging applications. During the synthesis of OLLA-g-BC, hydrophilic BC is converted into hydrophobic due to structural grafting of OLLA chains with BC molecules. Subsequently, bionanocomposites films are fabricated using solution casting technique and characterized for structural, thermal, mechanical, optical, and gas-barrier properties. Morphological images showed uniform dispersion of BC nanospheres in the PLA matrix, which shows strong filler–matrix interaction. The degradation temperatures for bionanocomposites films were above PLA processing temperature indicating that bionanocomposite processing can be industrially viable. Bionanocomposites films displayed decrease in glass transition (Tg) and ~20% improvement in elongation with 10 wt % fillers indicating towards plasticization of PLA. PLA/OLLA-g-BC films showed a slight reduction in optical transparency but had excellent UV-blocking characteristics. Moreover, dispersed BC act as blocking agents within PLA matrix, reducing the diffusion through the bionanocomposite films which showed ~40% improvement in water-vapor barrier by 5 wt % filler addition, which is significant. The reduced Tg, improved elongation combined with improved hydrophobicity and water-vapor barrier make them suitable candidate for flexible food-packaging applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47903. 相似文献
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Berhane H. Gebreslassie Randall Waymire Fengqi You 《American Institute of Chemical Engineers》2013,59(5):1599-1621
The superstructure optimization of algae‐based hydrocarbon biorefinery with sequestration of CO2 from power plant flue gas is proposed. The major processing steps include carbon capture, algae growth, dewatering, lipid extraction and power generation, and algal biorefinery. We propose a multiobjective mixed‐integer nonlinear programming (MINLP) model that simultaneously maximizes the net present value (NPV) and minimizes the global warming potential (GWP) subject to technology selection constraints, mass balance constraints, energy balance constraints, technoeconomic analysis constraints, and environmental impact constraints. The model simultaneously determines the optimal decisions that include production capacity, size of each processing unit, mass flow rates at each stage of the process, utility consumption, economic, and environmental performances. We propose a two‐stage heuristic solution algorithm to solve the nonconvex MINLP model. Finally, the bicriteria optimization problem is solved with ε‐constraint method, and the resulting Pareto‐optimal curve reveals the trade‐off between the economic and environmental criteria. The results show that for maximum NPV, the optimal process design uses direct flue gas, a tubular photobioreactor for algae growth, a filtration dewatering unit, and a hydroprocessing pathway leading to 47.1 MM gallons of green diesel production per year at $6.33/gal corresponding to GWP of 108.7 kg CO2‐eq per gallon. © 2013 American Institute of Chemical Engineers AIChE J, 59: 1599–1621, 2013 相似文献