Bacterial cellulose properties

Bacterial cellulose properties and suitability as a medical implant for cartilage tissue engineering... 

Bacterial Cellulose. Development of a new strain of Acetobacter may lead to economical production of another novel ceUulose. CeUulon fiber has a very fine fiber diameter and therefore a much larger surface area, which makes it physicaUy distinct from wood ceUulose. Its physical properties mote closely resemble those of the microcrystalline ceUuloses thus it feels smooth ia the mouth, has a high water-binding capacity, and provides viscous aqueous dispersions at low concentration. It iateracts synergisticaUy with xanthan and CMC for enhanced viscosity and stabUity. 

Reticulated bacterial cellulose may be used in place of a conventional gellant or in combination with conventional gellants to provide enhanced drilling muds [1837]. The addition of relatively small quantities of reticulated bacterial cellulose to wellbore drilling muds enhances their rheologic properties. 

Reticulated Bacterial Cellulose. A cellulose with an intertwined reticulated structure, produced from bacteria, has unique properties and functionalities unlike other conventional celluloses. When added to aqueous systems, reticulated bacterial cellulose improves the fluid rheology and the particle suspension over a wide range of conditions [1836]. Test results showed advantages in fluid performance and significant economic benefits by the addition of reticulated bacterial cellulose. 

Relatively small quantities of a bacterial cellulose (0.60 to 1.8 g/liter) in hydraulic fracturing fluids enhance their rheologic properties [1425]. Proppant suspension is enhanced and friction loss through well casings is reduced. 

Slezak A, Kucharzewski M, Jasik-Slezak J (2005) Polim Med 35 23 Medical properties of membrane dressings made from bacterial cellulose... 

Bacterial cellulose has several properties that have been identified as useful for PEM fuel cell development, including thermal stability and low hydrogen crossover characteristics. 

Different strategies to confer ion-exchange properties on bacterial cellulose were investigated. The s mthesis of a cellulose phosphate membrane was the most successful. 

Bacterial cellulose has several unique properties that potentially make it a valuable material for the development of PEM fuel cells (Reference 1) (1) it is an inexpensive and non-toxic natural resource (2) it has good chemical and mechanical stability (3) it is very hydrophilic and (4) it doesn t re-swell after drying. Additionally, its thermal stability and gas crossover characteristics are superior to Nation 117 , a material currently widely used as a proton conductive membrane in PEM fuel cells. 

Several different strategies were employed to modify bacterial cellulose with ion-exchange groups. Of the methods attempted, modification of native bacterial cellulose with phosphate groups was the most successful (Figure 2). The properties of the... 

Table 1. Comparison of the Properties of Cellulose Phosphate with Native Bacterial Cellulose and Nafion 117 ...

The strengths of the resulting dried sheets were tested by applying mechanical compression forces to determine the relative effects of the bacterial strains. As shown (Table 2), there were no significant differences between the textures of all bacterial cellulose strength levels derived from the three strains. Both coconut and pineapple juices yielded the same strength rating. The mechanical properties of bacterial cellulose, both air-dried and hot-pressed... 

This study showed that the bacterial cellulose derived fix)m coconut and pineapple juices can be converted efficiently to bacterial cellulose by the supplementation of yeast extract and ethanol under static fermentation conditions at 30 °C. Bacterial celluloses produced from all strains are growth associated products. Coconut juice seems to be a better substrate than pineapple juice. In view of energy consumption, the productivity of BC on this medium is high, which makes the production costs lower than expected. It is also clear that different A. xylinum strains produce different BC content levels under the same inoculation volumes and under static cultivation conditions. These results suggest that bacterial cellulose pellicles of all strains appear to be easily applied to use in many applications such as food, paper, and textile industries, without requiring additional steps of decolorization and purification. Furthermore, the properties of cellulose, in tenns of crystallinity, high water-absorption capacity, and mechanical strength of the reported strains, have additional applications in cosmetics and medicine. 

Native cellulose are commonly modified by physical, chemical, enzymic, or genetic means in order to obtain specific functional properties, and to improve some of the inherent properties that limit their utility in certain application. Physical/surface modification of cellulose are performed in order to clean the fiber surface, chemically modify the surface, stop the moisture absorption process, and increase the surface roughness. " Among the various pretreatment techniques, silylation, mercerization, peroxide, benzoylation, graft copolymerization, and bacterial cellulose treatment are the best methods for surface modification of natural fibers. 

Reinikainen, T. et al.. Comparison of the adsorption properties of a single-chain antibody fragment fused to a fungal or bacterial cellulose-binding domain. Enzyme Microb. Technol., 20, 143,1997. 

Backdahl, H., Helenius, G., Bodin, A., Nannmark, U., Johansson, B. R., Risberg, B., and Gatenholm, P. (2006). Mechanical properties of bacterial cellulose and interactions with smooth muscle cells,... 

Zhang, S., and Luo, J. (2011). Preparation and properties of bacterial cellulose/alginate blend bio-fibers,/. Eng. Fiber. Fabr., 6,69-72. 

Nge, T. T., Nogi, M., Yano, H., and Sugiyama, J. (2010). Microstructure and mechanical properties of bacterial cellulose/chitosan porous scaffold, QslMSS f 349-363. 

Cellulose, like the polysaccharides above, has certain drawbacks. These include poor solubility in common solvents, poor crease resistance, poor dimensional stability, lack of thermoplasticity, high hydrophilicity, and lack of antimicrobial properties. To overcome such drawbacks, the controlled physical and/or chemical modification of the cellulose structure is essential [160]. Introduction of functional groups into cellulose can alleviate these problems while maintaining the desirable intrinsic properties of cellulose. Apart from the conventional plant source, cellulose is also obtained from bacteria, termed bacterial cellulose. 

Nanocellulose, such as that produced by the bacteria Gluconacetobacter xylinus (bacterial cellulose, BC), is an emerging biomaterial with great potential in several applications. The performance of bacterial cellulose stems from its high purity, ultra-fine network structure and high mechanical properties in the dry state [114]. These features allow its applications in scaffold for tissue regeneration, medical applications and nanocomposites. A few researchers have used bacterial cellulose mats to reinforce polymeric matrices and scaffolds with wound healing properties [115-121]. BC is pure cellulose made by bacterial fabrication via biochemical... 

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