Acetobacter xylinum bacteria cellulose

Microbial cellulose (MC), also known as bacterial cellulose synthesized by Acetobacter xylinum bacteria, is a promising natural polymer which is chemically the same as plant cellulose, which has become a perfect matrix for wound healing system. Because of its unique physical and mechanical properties as well as its purity and... 

The bacterial cellulose synthase from Acetobacter xylinum can be solubilized with detergents, and the resulting enzyme generates characteristic 1.7 ran cellulose fibrils (Fig. 20-4) from UDP-glucose.125/127-129 These are similar, but not identical, to the fibrils of cellulose I produced by intact bacteria.125 130 Each native fibril appears as a left-handed helix which may contain about nine parallel chains in a crystalline array. Three of these helices appear to coil together (Fig. 20-4) to form a larger 3.7-nm left-handed helical fibril. Similar fibrils are formed by plants. In both... 

The kind of polysaccharides that are isolated from different bacteria are as follows Alginate, a linear copolymer with (l-4)-linked p-D-mannuronate and its a-L-guluronate residues that is produced by two bacterial genera Pseudomonas species and Azotobacter vinelandii [4]. Bacterial alginates are useful for the production of micro- or nanostructures suitable for medical applications. Cellulose, a p (1—>4) linked D-glucose unit obtained from Acetobacter xylinum. Cellulose of plant origin is usually impure as it contains... 

Romling U. (2002). Molecular biology of cellulose production in bacteria. Res Microbiol 153 205-212. Ross P, Aloni Y, Weinhouse H., Michaeli D., Weinberger-Ohana P., Mayer R., and Benziman M. 1986. Control of cellulose synthesis in Acetobacter xylinum a unique guanyl ologonucleotide is the immediate activator of the cellulose synthase. Carbohydrate Res 149 101-117. 

In the cellulose-producing bacterium Acetobacter xylinum, the phosphodiesterase A1 protein (AxPDEAl) functions to hydrolyze a potent allosteric activator of the bacterial cellulose synthase, the cyclic nucleotide [cyclic bis(3 —> 5 )diguanylic acid, or c-di-GMP] (17). xPDEAl was recently shown to contain an N-terminal regulatory heme-PAS domain that, when bound to O2, inhibits the C-terminal phosphodiesterase activity (10). Thus in cultures of this obligate aerobe, O2 is now thought to enhance the construction of a buoyant cellulose pellicle by the cells nearest to the media surface for possible use as a biofilm. The type of phosphodiesterase domain found in AxPDEAl, though not extensively studied, is widespread in Bacteria. 

Cellulose has been said to be the most abundant organic compound on the Earth. It is the major structural component of the cell wall of higher plants. We have already mentioned that it occurs in a very pure form in the cotton boll. It is also a major component of flax (80%), jute (60-70%), and wood (40-50%). Pure cellulose is also formed by some bacteria such as Acetobacter xylinum and related species... 

Some strains of acetic acid bacteria produce a gelatinous membrane called a pellicle at the surface of liquid cultures (Fig. 14.1a). The group of cellulose-producing acetic acid bacteria was previously known as Acetobacter xylinum (Yamada and Yukphan 2008) and was recently transferred to a newly proposed genus. 

Kojima Y, Tonouchi N, Tsuchida T, YoshinagaF, Yamada Y (1998) The characterization of acetic acid bacteria efficiently producing bacterial cellulose liom sucrose the proposal of Acetobacter xylinum subsp. nonacetoxidans subsp. nov. Biosd Biotechnol Biochem 62 185-187 Kose R, Sunagawa N, Yoshida M, Tajima K (2013) One step production of nanofibrillated bacterial cellulose (NFBC) from waste glycerol using Glulconacetobacter intermedius NED-01. Cellulose 20 2971-2979... 

The main sources of cellulose are issued to i) primitive organisms like bacteria ( Acetobacter xylinum), algae (ex Valonia, Cladophora, Microdictyon) ii) plants (ex wood, cotton, flax, ramie, jute, parenchyma of sugar beet pulp...) and iii) envelop of sea animals belonging to the Ascidians family (ex tunicate). 

Before going into detailed descriptions about the CSAS application to explore the cellulose self-assembly, let us first briefly describe some common features of the two synthetic routes. The artificial synthesis of cellulose to be discussed here, which was first reported by Kobayashi et involves the enzymatic polymerization of the special substrate monomer at a specific reaction site of the so-called cleft in cellulase used as a catalytic enzyme that will be detailed in Section 2.13.3. The biosynthesis of cellulose involves also the enzymatic polymerization of uridine diphosphate glucose (UDP-glucose) at the specific reaction sites of the so-called terminal complex (TC) on the outer membrane of cytoplasm of bacteria genera Acetobacter xylinum (AX)In both systems, the synthesized cellulose molecules are self-assembled in situ in the reaction medium. 

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