Gluconacetobacter xylinus

Gluconacetobacter xylinus to optimize cellulose formation on the laboratory-scale [12]. As a result of systematic and comprehensive research over the last 10-15 years, broad knowledge of the formation and structure of BC has been acquired. This work is an important part of the integration of biotechnological methods into polysaccharide chemistry and the development of cellulose products with new properties and application potential. 

Fig. 13 Scheme of BASYC tube formation by Gluconacetobacter xylinus (former Aceto-bacter xylinus) (DSM 14666) starting from glucose [65]... 

Keshk, S.M.A.S. Haija, M.A. A new method for produeing microcrystaUine eeUulose from Gluconacetobacter xylinus and kenaf. Carbohydr. Polym. 2011,84 (4), 1301-1305. 

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... 

Cellulose was defined as a chemical substance related to polysaccharides in 1838 thanks to the works of French chemist Anselme Payen, who isolated it from plant matter and determined its chemical formula (Payen, 1838). Cellulose is the most abundant organic matter on Earth. Total resources of cellulose in nature reach one trillion tons (Klemm et al., 2005). Moreover, being renewable in nature, a mass of this biopolymer increases by approximately 100 billion tons annually as a result of photobiosynthesis (Field et al., 1998). Cellulose is present in all plants and algae cellulose of the tunicin type forms the shells of certain marine creatures, and it is also synthesized by some microorganisms, for example, Gluconacetobacter xylinus. 

Keywords Bacterial nanocellulose, Gluconacetobacter xylinus, production conditions, applications... 

Synthecel Depuy Cellulose Biosynthesized by Gluconacetobacter xylinus Nonadhesive Biosynthesized cellulose and water... 

Gluconacetobacter xylinus) produces a three-dimensional network of bundles of cellulose fibrils. Pure sheets of bacterial cellulose (BC) can be used in composites without any further disintegration [25]. 

In G. xylinus, cellulose synthesis is tightly associated with catabolic processes of oxidation and consumes as much as 10% of energy derived from catabolic reactions. Production of BC does not interfere with other anabohc processes, including protein synthesis. Gluconacetobacter xylinus follows either pentose phosphate cycle or the Krebs cycle coupled with gluconeogenesis (Ross et al., 1991 Tonouchi et al., 1996). 

Table 10.1 Bacterial Cellulose (BC) productivity of six Gluconacetobacter xylinus strains in the HS, MO, and MOL Media...

Figure 10.6 X-ray pattern of cellulose from Avicel PH 101, Gluconacetobacter xylinus and kenaf.

Keshk, S.M.A.S., 2002. Gluconacetobacter xylinus a new resource for cellulose. Egyptian Journal of Biotechnology 11, 305. 

Wu, J.-M., Liu, R.-H., 2012. Thin stillage supplementation greatly enhances bacterial cellulose production by Gluconacetobacter xylinus. Carbohydrate Polymers 90 (1), 116-121. 

The authors developed a unique form of i-glucan association, nematic ordered cellulose (NOC) that is molecularly ordered, yet noncrystalline. NOC has unique characteristics in particular, its surface properties provide with a function of tracks or scaffolds for regulated movements and fiber production of Acetobacter xylinum (=Gluconacetobacter xylinus), which produces cellulose ribbon-like nanofibers with 40-60 nm in width and moves due to the inverse force of the secretion of the fibers (Kondo et al. 2002). This review attempts to reveal the exclusive superstructure-property relationship in order to extend the usage of this nematic-ordered cellulose film as a functional template. In addition, this describes the other carbohydrate polymers with a variety of hierarchical nematic-ordered states at various scales, the so-called nano/micro hierarchical structures, which would allow development of new functional-ordered scaffolds. 

C-NMR chemical shift data of cellulose 7a have been determined by Hesse-Ertelt et al by INADEQUATE and RAI techniques applied to uniformly C-labelled bacterial celluloses of different Gluconacetobacter xylinus strains. The robustness of the refocused INADEQUATE MAS NMR pulse sequence for probing through-bond connectivities has been demonstrated by Cadars et al in a large range of solid-state applications. The authors present a detailed account that combines product-operator analysis, numerical simulations and experiments of the behaviour of a three-spin system during the refocused INADEQUATE pulse sequence. 

Figure 2.1 Scanning electron microscopy (SEM) images of Gluconacetobacter xylinus and BC network of micro and nano fibrils and schematic description of the formation of bacterial cellulose. Reproduced with permission from [7].

A study by Matsuoka et al. [70] foimd that CSL was the most suitable nitrogen source for cellulose production in Gluconacetobacter xylinus subspecies sucrofermen-tans BPR2001, over yeast extract, soytone and peptone. Similar findings were reported by Nguyen et al. [57] who found that CSL at a concentration of 4% resulted in a higher cellulose yield than peptone, yeast extract, beef extract or malt extract. 

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