Fermentation defined

Modern methods of amino-acid and peptide analysis, have enabled the complete amino-acid sequence of a number of proteins to be worked out. The grosser structure can be determined by X-ray diffraction procedures. Proteins have molecular weights ranging from about 6 000 000 to 5 000 (although the dividing line between a protein and a peptide is ill defined). Edible proteins can be produced from petroleum and nutrients under fermentation. 

Among the vitally necessary elements the most important are Fe, Zn, K, Ca, S. Some of them are imbedded in the stmcture of many ferments, amino acids, intracellular liquid, the other define transmembrane electrical potential. In the paper the contents of elements in whole blood and semm by X-ray fluorescence spectrometry is studied. 

Productivity is an important parameter in evaluating the cost-effectiveness of a fermentation. It is defined as ... 

There are several stages common to most fermentation processes but before identifying these it is appropriate to define some terms which will appear during this Chapter. Let us first distinguish between primary and secondary metabolites. 

The term fermentation was obtained from the Latin verb fervere which describes the action of yeast or malt on sugar or fruit extracts and grain. The boiling is due to the production of carbon dioxide bubbles from the aqueous phase under the anaerobic catabolism of carbohydrates in the fermentation media. The art of fermentation is defined as the chemical transformation of organic compounds with the aid of enzymes. The ability of yeast to make alcohol was known to the Babylonians and Sumerians before 6000 bc. The Egyptians discovered the generation of carbon dioxide by brewer s yeast in the preparation... 

Mass transfer is calculated by the empirical correlation defined for non-Newtonian filamentous fermentation ... 

Before energy balance is calculated, we need to make mass balance. Figure 9.1 shows the material balance for ethanol and glycerol fermentation. Put simply, mass into the system is equal to mass out of die system. The mass of carbon dioxide is calculated by adding mass of dry cell, mass of glycerol, mass of edianol and mass of water at product stream and then subtracting die sum from die feed stream. As a result, die mass of carbon dioxide is defined. The heat of the reaction is calculated by the following equation ... 

All of the above processes are operated as batch fermentations, in which a volume of sterile medium in a vessel is inoculated. The broth is fermented for a defined period. The tank is then emptied and the products are separated to obtain the antibiotic. The vessel is then recharged for batch operation with medium and the sequence repeated, as often as required. Continuous fermentation is not common practice in the antibiotics industry. The antibiotic concentration will rarely exceed 20gT 1 and may be as low as 0.5g-l 1. 

The mass transfer coefficient for non-coalescing air bubbled in the fermentation broth in turbulent regime is frequently discussed in the literature.6 The volumetric mass transfer coefficient is defined by the following correlation ... 

Microbial insecticides are very complex materials in their final formulation, because they are produced by fermentation of a variety of natural products. For growth, the bacteria must be provided with a source of carbon, nitrogen, and mineral salts. Sufficient nutrient is provided to take the strain of choice through its life cycle to complete sporulation with concomitant parasporal body formation. Certain crystalliferous bacilli require sources of preformed vitamins and/or amino acids for growth. Media for growing these bacilli may vary from completely soluble, defined formulations, usable for bench scale work, to rich media containing insoluble constituents for production situations (10,27). Complex natural materials such as cottonseed, soybean, and fish meal are commonly used. In fact, one such commercial production method (25) is based on use of a semisolid medium, a bran, which becomes part of the final product. 

Fermentation occurs naturally in various microorganisms such as bacteria, yeasts, fungi and in mammalian muscle. Yeasts were discovered to have connection with fermentation as observed by Louis Pasteur and originally defined as respiration without air. However, it does not have to always occur in anaerobic condition. For example, starch when fermented under... 

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