Fermenters closed

Fermenter Closed apparatus in which a batch fermentation process is carried out. 

Figure 6.6. Growth of P. parvulus strains WS-9 and C5 in Merlot wines that did not have MLF (open squares) and wines that completed the secondary fermentation (closed squares). Adapted from Edwards et al. (1994) with the kind permission of the American Journal of Enology and Viticulture.

Starch polymers EPS - Current MSW management practice (landfill, incineration) - Average MSW incineration plant - Separate collection 8c optimised MSWI plant - Composting - DSD collection system and blast furnace - Fermentation - Closed-loop mechanical recycling - DSD collection, - Open-loop mechanical recycling blast furnace... 

In 1984,150 million gallons of ethanol were produced synthetically in the United States, and around 500 million gallons of ethanol were produced by fermentation. Close to 1.1 billion gallons of fermentation alcohol will be produced in 1992. Synthetic ethanol is produced from ethylene via catalytic hydration. Its major U.S. producers include Shell Chemical, Union Carbide, National Distillers and... 

Process Va.ria.tlons. The conventional techniques for tea manufacture have been replaced in part by newer processing methods adopted for a greater degree of automation and control. These newer methods include withering modification (78), different types of maceration equipment (79), closed systems for fermentation (80), and fluid-bed dryers (81). A thermal process has been described which utilizes decreased time periods for enzymatic reactions but depends on heat treatment at 50—65°C to develop black tea character (82). It is claimed that tannin—protein complex formation is decreased and, therefore, greater tannin extractabiUty is achieved. Tea value is beheved to be increased through use of this process. 

As you might have already gathered, the majority of industrial fermentations are batch processes. In closed batch systems, the growth medium is inoculated with cells and growth and product formation is allowed to proceed until the required amount of conversion has taken place. After harvesting the culture the vessel is cleaned, sterilised and filled with fresh medium prior to inoculation. For some processes, addition of all the feedstock prior to inoculation, as is done in closed batch fermentations, is undesirable and it is preferable to incrementally add the carbon source as the fermentation proceeds. Such a process is known as fed-batch culture and the approach is often used to extend the lifetime of batch cultures and thus product yields fed-batch cultures are considered further in Section 2.7.4. 

Special mention must be made of poly(lactic acid), a biodegradable/bio-resorbable polyester, obtained from renewable resources through fermentation of com starch sugar. This polymer can compete with conventional thermoplastics such as PET for conventional textile fibers or engineering plastics applications. Hie first Dow-Cargill PLA manufacturing facility is scheduled to produce up to 140,000 tons of Nature Works PLA per year beginning in 200245 at an estimated price close to that of other thermoplastic resins U.S. l/kg.46 Other plants are planned to be built in the near future.45... 

A typical fermenter is a closed, vertical, cylindrical, stainless steel vessel with eonvexly dished ends and of 25-250 capacity. Its height is usually two to three times its diameter. Figure 7.2 shows such a vessel diagramatically, and Fig. 7.3 gives a view inside an actual vessel. 

Mutans streptococci are the major pathogenic organisms of dental caries in humans. The pathogenicity is closely related to production of extracellular, water-insoluble glucans from sucrose by glucosyltransferase and acid release from various fermentable sugars. Poly(catechin) obtained by HRP catalyst in a phosphate buffer (pH 6) markedly inhibited glucosyltransferase from Streptococcus sorbrinus 6715, whereas the inhibitory effect of catechin for this enzyme was very low. 

The microorganism Streptomyces halstedii elaborates an antibiotic substance, called carbomycin32 or Magnamycin,33 which has been isolated from the fermentation broth by simple, solvent extraction, and then purified by recrystallization. (Examination of the resulting mother liquors has led to the isolation of a closely similar compound designated as Magnamycin B. 34) Carbomycin has low toxicity,85 and appears to be an effective and satis-... 

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