Fundamentals of Microbiology
Jeffrey C. PommervilleSözler ve Alıntılar
lumps of marble (CaCO3) are sometimes added to cultures containing fermentable substances like glucose, sucrose or lactose, to maintain the pH unchanged, that is, to neutralize the acid produced by fermentation. otherwise the organisms in the culture would quickly cease growth or die. colloidal substances such as charcoal, precipitates of phosphates, kaolin, etc., which adsorb hydrogen or hydroxyl ions directly, are also active buffers and are used in biological systems.
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lewis carroll, tşk reis herkes kullanıyo bunu
we find, as did Alice when she passed "Through the Looking Glass," many more strange and beautiful creatures.
family mycobacteriaceae
the family consists of only the genus Mycobacterium. these are gram- positive, noncmotile, aerobic, non-sporeforming rods. the Ziehl-Neelsen stain is of special value in the identification of mycobacteria, since they are unique in being strongly acid-fast. morphologically, they are much like ordinary bacteria except for being somewhat curved and spindle-shaped, and showing beaded or granular cells. the granules are often called Much granules after the first writer to describe them. they have been regarded as forms in a life cycle of tubercle bacillus or nuclear apparatus. the most acceptable view at present is that they are artifacts resulting from staining processes. the mycobacteria branch only slightly, so that X, Y, L and similar forms are sometimes seen. filament formation is minimal and transitory. most of them are harmless saprophytes living in the soil and decaying organic matter. none of them forms conidia or aerial hyphae.
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as pointed out by Skerman, "recognition of them as species has come through the gradual recognition of the constancy of certain characteristics which they display...” “variants have been recognized only because certain characters were selected as representative of a species."
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antibody formation and adaptive enzyme formation are remarkably similar phenomena. in each type of response the cells react to a chemical stimulus by forming a complex, protein substance, the molecules of which are so constructed as to combine and interact specifically with the chemical agent which stimulated their production. when the stimulus is not poisonous, and/or is nutrient in character, we say that an adaptive enzyme has been produced. antibodies are not all enzymes, but they are very enzyme-like, especially if we regard complement as a sort of kinase or enzyme-activator.
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