Bacteria lipids, function

Particulates can either cross into the lymphatics at the spaces in the tracheobronchial wall where epithelial cells directly overlay lymphoid tissue or pass through the endothelium of thin capillary walls in the air spaces. The transfer is a portion of a clearance mechanism that assists the lung in maintaining its normal function of gas exchange. Absorbtion and transport mechanisms of a variety of materials that enter the lymphatics continue to be studied. It was shown early in this century that water, dyes, proteins, bacteria, lipids, and particulates enter the lymphatic system relatively easily. The rates of transport and quantity vary with the size and chemistry of the material. Classic studies by Kihara (1924 1950) and Nishikawa (1941) dem-... 

Delong, E.F. and Yayanos, A.A. (1986) Biochemical function and ecological significance of novel bacteria lipids in deep-sea prokaryotes. Appl. Environ. Microbiol. 51, 730-737. 

Rice bran fiber has fructo-oligosaccharides - a pre-biotic that helps friendly bacteria to proliferate in the gastrointestinal environment and improves intestinal and colon health (Tomlin and Read, 1988). Recent studies in humans (Kahlon and Chow, 1997) have revealed that rice bran fiber not only normalizes bowel function, but also helps in conditions such as irritable bowel syndrome (IBS), inflammatory bowel disease (IBD) and Crohn s disease, and lowers the lipid levels. Rice bran fiber has been shown to significantly reduce renal stones (Jahnen et al., 1992). It is a good source of fiber in weight loss programs and therapeutic fiber diets for diabetics and heart patients. Fiber diets prevent cancer of the colon and large bowel, control obesity and improve bowel function. 

In Gram-negative bacteria which are characterised by a rather complex cell envelope, the CM is also referred to as inner membrane to distinguish it from a second lipid bilayer, termed outer membrane (OM). The space between these two layers is called the periplasm (PP). In the periplasmic space, many proteins are found with a variety of functions. Some are involved in biosynthesis and/or export of cell wall components and surface structures (e.g. pili, flagellae,... 

Recent results indicate that not only topogenic signals and membrane composition contribute to the proper topology of a membrane protein. The antimicrobial peptide nisin, produced by Lactococcus lactis, kills Gram-positive bacteria via pore formation, thus leading to the permeabilisation of the membrane. Nisin depends on the cell-wall precursor Lipid II, which functions as a docking molecule to support a perpendicular stable transmembrane orientation [43]. 

Lipid A constitutes the covalently bound lipid component and the least variable component of LPS (25). It anchors LPS to the bacterial cell by hydrophobic and electrostatic forces and mediates or contributes to many of the functions and activities that LPS exerts in prokaryotic and eukaryotic organisms. In the following sections, the primary structure of lipid A of different Gram-negative bacteria is described, together with some of its characteristic biological properties. Furthermore, this article describes some of the principal methods that have been used for the structural analysis of lipid A and discusses their merits and limitations. 

Mechanisms by which ozone might interfere with bactericidal function include an alteration in cell-membrane function that produces a loss in phagocytic ability and is perhaps mediated by lipid peroxides and a decrease in the ability of veolar macrophages to kill phagocytized bacteria. Leukocytes in general appear to have a multiplicity of mechanisms for destroying ingested bacteria. 

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