Fermentation of ethanol

In a batch fermentation of ethanol, kinetic data were collected as product formed. The data are shown in Table E.5.1. The data will be used to design a continuous bioreactor (CSTR) with a 1001 working volume. 

Acetobacter bacteria oxidatively convert wine to vinegar through an aerobic fermentation of ethanol (a primary alcohol) into acetic acid (a carboxylic acid) ... 

The once-obscure field of exploring potential uses of bacteria and their enzyme systems that thrive in hot or boiling water (extremophiles)—from geysers and sea bed vents in tectonically active areas—is another instance of nature generating practically valuable resources. The use of hyperthermophilic enzymes to speed the fermentation of ethanol from starch is a case in point.33... 

The anaerobic fermentation of ethanol from sugar (Fig. 8.3) goes back to the Stone Age. In 1997, the fermentation of ethanol, mainly from sugar cane, molasses (Brazil) and corn (USA), amounted to 24 Mt worldwide, dwarfing the chemical production of 2.6 Mt a 1 [23]. Iogen (Canada) produces ethanol from... 

Raw materials for the fermentation of ethanol are sugar molasses (Brazil), com steep liquor and corn starch hydrolysate (USA). Industrial ethanol fermentation is highly developed and the stoichiometric yield can be as high as 1.9 mol mol-1 [25, 26]. The... 

The unfavorable energy balance notwithstanding, the fermentation of ethanol, as well as other chemicals, from lignocellulose hydrolysate is considered highly desirable by some to avoid competition with food production. We note, however, that the large scale processing of waste lignocellulose runs counter to sensible... 

For an extensive review of the industrial fermentation of ethanol see N. Kosaric, in Biotechnology Vol. 6. Products of Primary Metabolism, M. Roehr (Ed.), 2nd edn, Wiley-VCH, Weinheim, 1996,... 

Vinegar (acetic acid) by aerobic fermentation of ethanol Acetobacter... 

Figure 4. Dependence of biocatalytic activities for the batch fermentation of ethanol from glucose with immobilized yeast cells as a function of incubation time (time for cellgrowth in the carrier) for various initial cell loadings in epoxy carriers.

Vinegar, or acetic acic, can be made simply through the fermentation of ethanol — yes, fermenting what was fermented However, this process is relatively slow. Acetic acid can be produced much quicker using a rhodium complex that causes the carbonylation of methanol. This process, known as the Monsanto process (named cifter the Monsanto company), accounts for over a million tons of acetic acid a year. The catalytic cycle is a six-step process, as shown in Figure 16-5. 

Figure 10 shows the inherit advantage of lactic acid produced by the universal metabohc pathway shared by most living organisms from humans, to plants, to microbes. Through the anaerobic glycolysis pathway, two lactic acid molecules (A/ =90) are produced from one glucose (M =180) with a 100% theoretical yield (i.e., no loss at all). For the anaerobic fermentation of ethanol, the theoretical yield is around 51% with two CO M =AA) molecules lost per glucose. After ethanol has been dehydrated to ethylene and polymerized into bio-PE, the theoretical yield from glucose is only around 31% compared with 80% for PLA (Fig. 10). For PHBV-like biopolymer synthesized in microbial cells, the building block is typically acetyl-CoA with around 51% theoretical yield after the loss of CO (decarboxylation) from...

Asli, M.S. 2009. A study on some efficient parameters in batch fermentation of ethanol using Saccharomyces cerevisiae SCI extracted from fermented siahe sardasht pomace. African Journal of Biotechnology, 9 2906-2912. 

Udriot, H., Ampuero, S., Marison, I. W., Stockar, U. (1989). Extractive fermentation of ethanol using membrane distillation. Biotechnology Letters, 11, 509—514. 

Acetic acid became known to mankind when vinegar, an aqueous solution of acetic acid, was discovered around 5000 BC by the Babylonians. Today, the major process of production of table vinegar is still the age-old aerobic fermentation of ethanol ... 

Fermentation of ethanol is conducted as a top fermentation and increasingly as a submerged oxidative process. In top fermentation the bacteria are cultivated on spongy, porous laminated carriers (usually beechwood shavings) with the alcoholic solution trickling down over carrier surfaces while a plentiful supply of air is provided from below. The fermentation is stopped at a 0.3% by volume residual ethanol level to avoid overoxidation, i. e., oxidation of acetic acid to CO2 and water. 

The abovementioned difficulty of ethanol production from plant biomass is even more serious for the production of acetic acid, which is produced by the fermentation of ethanol. For instance, only 0.67 g of acetic acid can be produced from 1 g of glucose, because fhe Acetobacter, which produces acetic acid, ferments glucose first to ethanol and thereafter to acetic acid. As a result, there is a great loss of carbon in the form of carbon dioxide (Liu ef al., 2006). The production of acetic acid is of great interest due to its usefubiess in the production of acetic anhydride and vinyl acetate. 

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