Fermentative assimilation

Fermentation is the incorporation of a fermenting substance with a substance which is to be fermented. For even as a small modicum of ferment, or yeast, can leaven a large mass of flour, so does the chemical ferment assimilate itself to the thing that is to be fermented. Whatsoever be the nature of the ferment, of such is the fermented matter. By ferment the philosophers understand a true body and a true matter, which, united to its proper Mercury, convert it into the nature thereof. Some will have that the stone itself is the ferment of a perfect body. For when the stone is so subtle, as the philosophers term it, that when it is projected over an imperfect body it floats after the manner of an oil, without combining therewith, we need some other body, which still retains traces of its former affinity therewith, which shall receive and introduce it into other bodies. 

A suitable fermentation medium contains water and a source of assimilable carbon and nitrogen and essential mineral salts. A typical medium suitable for production of chlorodemethyltetracycline is as follows ... 

The Fermentation Process The process by which this antifungal substance is produced is an aerobic fermentation of an aquaous nutrient medium inoculated with a pimaricin-producing strain of Streptomycesgihrosporeus. The nutrient medium contains an assimilable source of carbon such as starch, molasses, or glycerol, an assimilable source of nitrogen such as corn steep liquor and Inorganic cations such as potassium, sodium or calcium, and anions such as sulfate, phosphate or chloride. Trace elements such as boron, molybdenum or copper are supplied as needed in the form of impurities by the other constituents of the medium. 

A variety of commercial kits and automated systems are available to test the abilities of bacteria to assimilate, ferment, decarboxylate, or cleave selected organic compounds.46 Their reliability for species identification is usually greater with cultures from clinical samples, where a limited number of bacteria are commonly encountered, and less with environmental soil and water samples, where a great many uncommon or previously unidentified species not in the database are likely to be present.29,45 Additional tests beyond those found in the commercial kits may be necessary for example, the hydrolysis of various nitriles and amides is useful for identifying Rhodococcus spp.47 Some commercial kits for clinical use feature antimicrobial susceptibility testing.21... 

Evenepoel P, Claus D, Geypens B, Maes B, Hiele M, Rutgeerts P, et al Evidence for impaired assimilation and increased colonic fermentation of protein, related to gastric acid suppression therapy. Aliment Pharmacol Ther 1998 12 1011-1019. 

Figure 6.3 shows the time course of ethanol production as a function of feed composition (Table 6.3). The best feed solution was feed D which permitted the bed to run for eight hours without quenching and resulted in a higher ethanol yield (0.46) than feed A (0.35) which contained only glucose. Potassium and magnesium ions are known to stimulate fermentation (Jones and Greenfield, 1984 Maynard, 1993). Feed C caused the bed to quench after only two hours because, under anaerobic conditions, the yeast extract supplied was unable to be assimilated sufficiently quickly and the remainder was therefore... 

Certain amino acids are good sources of nitrogen and are readily assimilated by yeasts during fermentation (88). Castor (89) reported that 11 amino acids were largely removed from musts during yeast fermentation. 

Lactose, when fermented by laclic bacteria, is the source of the lactic acid formed in sour milk and whey. Lactose is helpful in establishing a slightly acid reaction in the intestine, which assists in calcium assimilation. 

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