Biomaterial Database

Distribution of lipopolysaccharide and the detection of a new subfraction in the cell envelope of a marine pseudomonad. 1977

J D Nelson, and R A Macleod

The three outer layers of the cell envelope of marine pseudomonad B-16, the loosely bound outer layer, the outer membrane, and the periplasmic space layer, are the only ones containing appreciable amounts of both lipid and carbohydrate. These layers and a fraction released into the medium during growth of the cells were examined for the presence of common antigens by double immunodiffusion using anti-whole serum. Each of the layers, the medium fraction, and lipopolysaccharide (LPS) isolated from the organism were shown to contain two or more diffusible components showing reactions of identity. Thus LPS is found in each of the three outer layers of the cell envelope of this gram-negative bacterium. The periplasmic space layer was found to contain a fraction accounting for 20% of the dry weight of the layer, which was sedimentable at 30,000 x g and contained lipid, protein, and carbohydrate. Double-immunodiffusion tests indicated that the fraction contained at least one of the two antigens present in isolated LPS. A particulate material was released by the cells during growth which gave a positive test for 2-keto-3-deoxyoctulosonic acid and cross-reacted serologically with LPS.

UI	MeSH Term	Description	Entries
D008070	Lipopolysaccharides	Lipid-containing polysaccharides which are endotoxins and important group-specific antigens. They are often derived from the cell wall of gram-negative bacteria and induce immunoglobulin secretion. The lipopolysaccharide molecule consists of three parts: LIPID A, core polysaccharide, and O-specific chains (O ANTIGENS). When derived from Escherichia coli, lipopolysaccharides serve as polyclonal B-cell mitogens commonly used in laboratory immunology. (From Dorland, 28th ed)	Lipopolysaccharide,Lipoglycans
D011135	Polysaccharides, Bacterial	Polysaccharides found in bacteria and in capsules thereof.	Bacterial Polysaccharides
D011549	Pseudomonas	A genus of gram-negative, aerobic, rod-shaped bacteria widely distributed in nature. Some species are pathogenic for humans, animals, and plants.	Chryseomonas,Pseudomona,Flavimonas
D002473	Cell Wall	The outermost layer of a cell in most PLANTS; BACTERIA; FUNGI; and ALGAE. The cell wall is usually a rigid structure that lies external to the CELL MEMBRANE, and provides a protective barrier against physical or chemical agents.	Cell Walls,Wall, Cell,Walls, Cell
D000942	Antigens, Bacterial	Substances elaborated by bacteria that have antigenic activity.	Bacterial Antigen,Bacterial Antigens,Antigen, Bacterial
D012623	Seawater	The salinated water of OCEANS AND SEAS that provides habitat for marine organisms.	Sea Water,Sea Waters,Seawaters,Water, Sea,Waters, Sea
D013347	Subcellular Fractions	Components of a cell produced by various separation techniques which, though they disrupt the delicate anatomy of a cell, preserve the structure and physiology of its functioning constituents for biochemical and ultrastructural analysis. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p163)	Fraction, Subcellular,Fractions, Subcellular,Subcellular Fraction
D014871	Water Microbiology	The presence of bacteria, viruses, and fungi in water. This term is not restricted to pathogenic organisms.	Microbiology, Water