Bacteria lipids

Lipopolysaccharides Human pathogenic and marine bacteria Lipid A + various attached oligosaccharide decorations Oxidative burst, and oxylipin production in L. digitata Kupper et al. 2006... 

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-... 

In some Gram-positive bacteria, lipid II may be further modified by attachment of 1-5 amino acid residues to the e-amino group of the lysine (or meso-DAP) residue. Frequently, these additional residues are... 

As the typical molecule in Gram-negative bacteria, lipid A can be used to detect the bacteria. Detection methods need to be rapid and sensitive therefore, a few rapid methods for lipid A micro-extraction from whole bacteria have been developed. 

The synthesis of microbial fat by bacteria is often ignored because the average fat concentration in dry biomass does not exceed 10%. However, there are strains of Arthrobacter sp., Mycobacterium, and Corynebacterium that are able to accumulate from 30 to 80% lipids in dry matter. Unfortunately, there are other problems related to low growth rates and yields of bacteria, lipid extraction, and the possible allergeiucity and toxicity of the resulting lipids. Microalgae (e.g., Botryococcus braunii and Chlorella pyrenoidosa) serve as attractive sources of PEFA. Dry biomass fat can amount to as much as 85% (Kay, 1991). Moreover, microalgae are a very... 

Keweloh, H. and H.J. Heipieper. Trans Unsaturated Fatty Acids in Bacteria. Lipids, 31 ,... 

Bacterial spores exhibit the most resistance to germicides followed by mycobacteria, nonlipid viruses, fungi, and vegetative bacteria. Lipid viruses exhibit the least resistance. Facilities should use FDA- or EPA-approved cleaning agents and should read and follow the manufacturer s instructions to ensure proper use. Their effectiveness depends on... 

Dionisi, F., Golay, P-A., EUi, M., and Fay, L.B. (1999) Stability of Cyclopropane and Conjugated Linoleic Acids During Fatty Acid Quantification in Lactic Acid Bacteria, Lipids 34, 1107-1115. 

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. 

Medium (many with potential for large) Amino Acids Fungus, Bacteria Lipids Proteins (specific) Purines, Pyrimidines, Nucleotides, Nucleic Acids scale... 

The progressive elongation of this acid leads to the formation of c -vaccenic acid (Cig), a precursor of lactobacillic acid (C19). In this last step, the double bond of the unsaturated acid (the precursor) is methylated to form the corresponding cyclopropanic acid. The fatty acid composition of the bacteria lipids varies during the physiological cycle and is also strongly influenced by several environmental factors. 

Rontani, J.-F., Christodoulou, S., and Koblizek, M. (2005) GC-MS Stmctural characterization of fatty acids from marine aerobic anoxygenic phototrophic bacteria. Lipids. 40,97-108. 

Some polymyxins are sold for second-line systemic therapy. Polymyxin B sulfate and colistimethate sodium can be used for intravenous, intramuscular, or intrathecal administration, especially for Pseudomonas aerupinosa mP QXiosis, but also for most other gram-negative organisms, such as those resistant to first-line antibiotics. Nephrotoxicity and various neurotoxicities are common in parenteral, but not in topical, use. Resistance to polymyxins develops slowly, involves mutation and, at least in some bacteria, adaptation, a poorly understood type of resistance that is rapidly lost on transfer to a medium free of polymyxin. Resistance can involve changes in the proteins, the lipopolysaccharides, and lipids of the outer membrane of the cell (52). Polymyxin and colistin show complete cross-resistance. 

Autotrophy A unique form of metabolism foimd only in bacteria. Inorganic compounds (e.g., NH3, N02-, S2, and Fe2+) are oxidized directly (without using sunlight) to yield energy. This metabolic mode also requires energy for C02 reduction, like photosynthesis, but no lipid-mediated processes are involved. This metabolic mode has also been called chemotrophy, chemoautotrophy, or chemolithotrophy. 

Glyoxylate cycle A modification of the Krebs cycle, which occurs in some bacteria. Acetyl coenzyme A is generated directly from oxidation of fatty acids or other lipid compounds. 

Mitochondria Mitochondria are organelles surrounded by two membranes that differ markedly in their protein and lipid composition. The inner membrane and its interior volume, the matrix, contain many important enzymes of energy metabolism. Mitochondria are about the size of bacteria, 1 fim. Cells contain hundreds of mitochondria, which collectively occupy about one-fifth of the cell volume. Mitochondria are the power plants of eukaryotic cells where carbohydrates, fats, and amino acids are oxidized to CO9 and H9O. The energy released is trapped as high-energy phosphate bonds in ATR... 

As shown in Figure 9.24, the outer membrane of Gram-negative bacteria is coated with a highly complex lipopolysaccharide, which consists of a lipid group (anchored in the outer membrane) joined to a polysaccharide made up of long chains with many different and characteristic repeating structures... 

FIGURE 9,24 Lipopolysaccharide (LPS) coats the outer membrane of Gram-uegative > bacteria. The lipid portion of the LPS is embedded iu the outer membrane and is linked to a complex polysaccharide. 

A lipopolysaccharide (LPS) is any compound consisting of covalently linked lipids and polysaccharides. The term is used more frequently to denote a cell wall component from Gram-negative bacteria. LPS has endotoxin activities and is a polyclonal stimulator of B-lymphocytes. 

This outcome was consistent with a hypothesis that structural deterioration could have been a byproduct of microorganism activity. The higher lipid content in the poorly preserved tissue suggests that those lipids are primarily extrinsic, that is, that they were produced by bacteria and/or fungi. As the food source for such microorganisms, the protein within the bone may have been substantially altered in concert with the microstructure deterioration. The quantification of the changes to the organic fraction became our next focus of research. 

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