Extracellular matrix cellulose

Zogaj, X., Nimtz, M., Rohde, M., Bokranz, W., and Romling, U. (2001). The multicellular morphotypes of Salmonella tpphimurium and Escherichia coli produce cellulose as the second component of the extracellular matrix. Mol. Microbiol. 39,1452-1463. 

In addition to their important roles as stored fuels (starch, glycogen, dextran) and as structural materials (cellulose, chitin, peptidoglycans), polysaccharides and oligosaccharides are information carriers they serve as destination labels for some proteins and as mediators of specific cell-cell interactions and interactions between cells and the extracellular matrix. Specific carbohydrate-containing molecules act in cell-cell recognition and... 

ECM, extracellular matrix is a complex network made up of polysaccharides, such as glycosaminoglycans or cellulose and proteins such as collagen, which are secreted by cells. 

Unlike animal cells, bacterial, fungal, and plant cells are surrounded by a rigid cell wall and lack the extracellular matrix found In animal tissues. The plasma membrane Is Intimately engaged In the assembly of cell walls, which in plants are built primarily of cellulose. The cell wall prevents the swelling or shrinking of a cell that would otherwise occur when It Is placed In a hypotonic or hyper-... 

Many natural hydrogels are known to be constituents of the extracellular matrix, mucin, glycocalix and so on. Jelly is a well-known example of the use of hydrogels in food. Hydrogels can be obtained from many hydrophilic polymers, either natural (e.g. cellulose, dextran, alginate, hyaltuonic acid, chitosan, pectin) or synthetic (e.g. poly(vinyl alcohol) (PVA), PEG, poly(vinyl pyrrolidone) (PVP), PHEMA, polyacrylamides). 

The susceptibility of cellulose to enzymatic hydrolysis is determined largely by its accessibility to extracellular enzymes secreted by or bound on the surface of cellulolytic microorganisms. Direct physical contact between these enzymes and the cellulosic substrate molecules is an essential prerequisite to hydrolysis. Since cellulose is an insoluble and structurally complex substrate, this contact can be achieved only by diffusion of the enzymes from the organism into the complex structural matrix of the cellulose. Any structural feature that limits the accessibility of the cellulose to enzymes by diffusion within the fiber will diminish the susceptibility of the cellulose of that fiber to enzymatic degradation. In this review, the influence of eight such structural features have been discussed in detail. 

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