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Bacteria physical appearance

In 1954, Jeanes et al.5 reported the formation of glucan(s) by 96 strains of bacteria that were primarily Leuconostoc strains. (There is a question here as to whether they are strains or species, particularly with regard to the formation of different kinds of polysaccharides. The classification of the time was to place them into one species, mesenteroides, that had several different strains. This classification stands today.) The polysaccharides were characterized by various properties such as optical rotation, viscosity, periodate oxidation profile, and physical appearance after alcohol precipitation. The latter were observed to have different appearances, which were described by Jeanes et al.5 in various qualitative terms such as pasty, fluid, stringy, tough, long, short, flocculent, and so on. These differences in appearance provided an early suggestion of differences in structure (see Table I). Both water-soluble and water-insoluble polysaccharides were formed, and some strains seemed to form more than one kind of polysaccharide, as judged by their water solubility and by differences in the amount of alcohol needed to precipitate them. [Pg.135]

The breakdown of matter by bacteria and fungi. It changes the chemical makeup and physical appearance of materials, deep water... [Pg.176]

Both the Institute of Petroleum and the ASTM acknowledge the lack of generally accepted criteria for what would be considered significant microbial contamination. The Institute of Petroleum indicates that microbial counts in the water bottom of 10 -10 CFU/L bacteria, 10 -10 CFU/L yeasts, 10 CFU/L molds and 10 CFU/L SRB, either alone or in combination, are considered to represent microbial contamination (Institute of Petroleum, 1996). The ASTM suggests that counts of 10 CFU/ml can be, in many cases, accepted in the water bottom but any microorganisms detected in the fuel should suggest the need for corrective measures (ASTM, 2001). The ASTM also cautions that microbial counts should be routinely monitored and if problems with fuel chemistry, performance or physical appearance are also noted then corrective action should be considered. [Pg.188]

The flow cytometer, fitted with both forward and side scatter detectors, generates a 2D plot indicating the distribution of light intensity, forward scatter (FS) versus side scatter (SS), and showing the physical profile of the particle responsible for the scatter. Figure 5.3 is such a plot for a mixture of five rod-shaped bacteria from our laboratory. The different strains appear in partly separated clusters (indicated by square boxes and dot color) along the side-scatter axis in the lower part of the plot. [Pg.99]

Let us consider the possible physical/chemical connections between eukaryotes (Table 7.2) and different prokaryotes (see Table 6.10), which might explain their origin and that of their compartments (Figure 7.2). We know from DNA/RNA/protcin sequences that there is some connectivity to both archaea and bacteria, but it appears... [Pg.283]

Resistance occurs as the result of one or more alterations in the cellular metabolism of the bacteria both mutation and plasmid-mediated resistance occurs. These changes, which can be irreversible, include alterations in the physical or enzymatic characteristics of the enzyme or enzymes that metabolize PABA and participate in the cellular synthesis of tetrahydrofolic acid. The appearance of alternative pathways for PABA synthesis within the bacteria or the development of an increased capacity to inactivate or eliminate the sulfonamide also may contribute to bacterial cell resistance. Bacteria that can use preformed folate are not inhibited by sulfonamides. [Pg.516]

Remark. The distinction between linear and nonlinear one-step processes has more physical significance than appears from the mathematical distinction between linear and nonlinear functions r(n) and g(n). In many cases n stands for a number of individuals, such as electrons, quanta, or bacteria. The master equation for pn is linear in n when these individuals do not interact, but follow their own individual random history regardless of the others. A nonlinear term in the equation means that the fate of each individual is affected by the total number of others present, as is particularly clear in example (iv) above. Thus linear master equations play a role similar to the ideal gas in gas theory. This state of affairs is described more formally in VII.6. [Pg.165]

THE NATURE AND MECHANISM OF INFLAMMATION Inflammation may be defined as a series of localized tissue responses to foreign stimuli, which may be biological (e.g. bacteria, fungi, viruses), chemical (e.g. croton oil) or physical (e.g. X-rays, ultra-violet light). Apart from external stimuli, it now appears than an endogenous factor, the autoimmune reaction, may initiate an inflammatory response. [Pg.59]

It is well known that the evolutionary process is subject to significant alterations under the influence of chemical and physical factors, which may result in the appearance of new fonns of organisms. Thus, as a response to the exposure to some toxins, toxin-resistant forms of insects have appeared. Similarly, widespread use of antibiotics resulted in new forms of bacteria which are antibiotic resistant. [Pg.263]


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