Fermentation, of carbohydrates

Prepare yeast extract broth by dissolving 0.5% w/v yeast extract in distilled water. 

For sugars that can be autoclaved (e.g., glucose and galactose), prepare as 2% w/v solutions in the yeast extract broth and transfer 10mL to capped 18 X 150 mm test tubes. Insert a Durham tube open-side down into each tube, loosely replace the cap, and autoclave at 121 C/250 F for 15 min. 

Because many sugars should not be autoclaved, prepare as 2% w/v solutions in the yeast extract broth and individually filter sterilize the solutions through 0.45 im membranes. For raffinose, prepare a 4% w/v solution because some strains only use part of the molecule (Yarrow, 1998). Transfer 10 mL aliquots of yeast extract broth to sterile 18 x 

150 mm test tubes, aseptically insert sterile Durham tubes open-side down into the test tubes, and cap. Note the volume of the air bubble prior to inoculation. 

Inoculate each tube with yeast to yield a slightly turbid suspension and incubate at 25 C/77°F, examining for gas formation at intervals of 2 to 3 days for up to one week. 

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Until World War 1 acetone was manufactured commercially by the dry distillation of calcium acetate from lime and pyroligneous acid (wood distillate) (9). During the war processes for acetic acid from acetylene and by fermentation supplanted the pyroligneous acid (10). In turn these methods were displaced by the process developed for the bacterial fermentation of carbohydrates (cornstarch and molasses) to acetone and alcohols (11). At one time Pubhcker Industries, Commercial Solvents, and National Distillers had combined biofermentation capacity of 22,700 metric tons of acetone per year. Biofermentation became noncompetitive around 1960 because of the economics of scale of the isopropyl alcohol dehydrogenation and cumene hydroperoxide processes. 

Itaconic 2Lcid[97-65-4] (methylenebutanedioic acid, methylenesuccinic acid) is a crystaUine, high, melting acid (mp = 167-168) produced commercially by fermentation of carbohydrates (1 4). Itaconic acid is produced in the broth from citric acid (qv). Isolated from the pyrolysis products of citric acid in 1836, this a-substituted acryUc acid received its name by rearrangement of aconitic, the acid from which it is formed by decarboxylation. 

In summary the majority of the world dtric add production is still via microbial fermentation of carbohydrate substrates (derived from plants) using Aspergillus niger. 

The catalyst is a mixture of copper, zinc oxide, and chromium(lll) oxide. Ethanol is produced in large quantities throughout the world by the fermentation of carbohydrates. It is also prepared by the hydration of ethene in an addition reaction ... 

Choi and Won (1999) have reported a very u.seful strategy of recovering relatively nonvolatile lactic acid (e.g. from fermentation of carbohydrates) as volatile methyl lactate using a cationic ion-exchange resin as the catalyst. In another column reactor the methyl lactate is hydrolysed, using a cationic ion-exchange resin as the catalyst, to lactic acid and methanol, and the latter is recycled. 

Molecular hydrogen is an important intermediate in the degradation of organic matter by microorganisms in anoxic habitats such as freshwater and marine sediments, wet land soils, and the gastrointestinal tract of animals. In these particular conditions H2 is produced during fermentation of carbohydrates, lipids, nucleic acids, and proteins by anaerobic bacteria and,... 

Rao SS, Edwards CA, Austen CJ, Bruce C, Read NW Impaired colonic fermentation of carbohydrate after ampicillin. Gastroenterology 1988 94 928-932. 

Weizmann A process for producing acetone and //-butanol by the fermentation of carbohydrates by bacteria isolated from soil or cereals. Later work has shown that effective bacteria are Clostridium acetobutylicum and Bacillus granulobacter pectinorum. Used in Britain in World War I for the manufacture of acetone, needed for the production of cordite. Subsequently operated by Commercial Solvents Corporation in Terre Haute, IN, and in two plants in Canada. Later abandoned in favor of synthetic processes. Invented by C. Weizmann in the University of Manchester in 1915, based on earlier work at the Pastern Institute by A. Fembach and E. H. Strange (hence the alternative name Fembach-Strange-Weizmann). The money that Weizmann obtained from royalties on this process was used in founding the State of Israel, of which he was the first president. 

Carboxylic Acids Obtained by Fermentation of Carbohydrates Lactic (2-hydroxy-propionic) acid obtained by fermentation of glucose and polysaccharides is used by NatureWorks (Cargill/Dow LLC) to prepare polylactide (PLA), a biodegradable or recyclable polymer with a potential production of 140000 t a-1 (Scheme 3.4) [23], This and other potential useful reactions from lactic acid have been reviewed by Datta and Henry [24],... 

These short-chain fatty acids are acetic, butyric, lactic and propionic acids, also known as volatile fatty acids, VFA. They are produced from fermentation of carbohydrate by microorganisms in the colon and oxidised by colonocytes or hepatocytes (see above and Chapter 4). Butyric acid is activated to produce butyryl-CoA, which is then degraded to acetyl-CoA by P-oxidation acetic acid is converted to acetyl-CoA for complete oxidation. Propionic acid is activated to form propionyl-CoA, which is then converted to succinate (Chapter 8). The fate of the latter is either oxidation or, conversion to glucose, via glu-coneogenesis in the liver. 

In 1904, Schardinger discovered the bacteriological formation of acetone from carbohydrates, and Pringsheim, in the years 1905-1909, described the reduction of carbohydrates to isopropyl alcohol and n-butyl alcohol. The subsequent work of Fernbach and Weizmann led to the development of an industry for the production of these substances by the fermentation of carbohydrates. ... 

Butanol, which at one time was an unwanted by-product in the preparation of acetone, is now the most important product of the fermentation. The building of a large new factory in Puerto Rico using 10,000 tons of molasses per annum for its production is an indication of this importance. Butanol is probably still the best solvent for cellulose nitrate lacquers. Dibutyl phthalate is certainly the most widely used plasticizer for synthetic resins, and butyl oleate, tributyl citrate and dibutyl tartrate have also been described as plasticizers. Another important use of butanol is as a source of butadiene, which serves as an intermediate in the conversion of sucrose into a synthetic rubber. Although in recent years other methods have been described for the preparation of butanol (for example, from ethyl alcohol and from acetylene), yet the fermentation of carbohydrates is still the cheapest process. 

Carbon dioxide also is produced along with ethanol from fermentation of carbohydrates by yeast ... 

Fig. 10.1 Precursors, intermediates, and metabolites of the main groups of flavour compounds produced during alcoholic fermentation of carbohydrates by Saccharomyces cerevisiae yeast... 

Although most naturally occurring lipids contain fatty acids with an even number of carbon atoms, fatty acids with an odd number of carbons are common in the lipids of many plants and some marine organisms. Cattle and other ruminant animals form large amounts of the three-carbon propionate (CH3—CH2—COO ) during fermentation of carbohydrates in the rumen. The propionate is absorbed into the blood and oxidized by the liver and other tissues. And small quantities of propionate are added as a mold inhibitor to some breads and cereals, thus entering the human diet. 

Ethanol, ethyl alcohol (mp, -114°C bp, 78°C), is a clear, colorless liquid widely used as a beverage ingredient, synthetic chemical, solvent, germicide, antifreeze, and gasoline additive. It is produced by the fermentation of carbohydrates or by the hydration of ethylene, as shown by the... 

L-Glutamic acid can be obtained directly from fermentation of carbohydrates with Micrococcus glutamicus or Brevihacterium divaricatum. 

Another biofuel candidate that can be derived from LA is 2-methyl tetrahydro-furan (2-MTHF), which is obtained via the intermediate yVl in a reaction pathway that includes both dehydration and hydrogenation steps [99, 100]. In a comparable reaction, itaconic acid, a platform chemical produced industrially by fermentation of carbohydrates such as glucose, can be converted into 3-methyl tetrahydrofuran [100]. The hydrogen required to produce yVl may be obtained from formic acid, via transfer... 

Wood, W. A. 1961. Fermentation of carbohydrates and related compounds. The Bacteria. II. New York Academic Press. 

Since the twenties and thirties butanol together with acetone was produced by fermentation of carbohydrates (corn). In the sixties the process was replaced by the hydroformylation of propene. In the OXO process alkenes react with synthesis gas in the presence of a homogeneous catalyst to give a mixture of branched and linear aldehydes ... 

Acarbose is an inhibitor of a-glucosidase (localized in the brush border of intestinal epithelium), which liberates glucose from disaccharides. It retards breakdown of carbohydrates, and hence absorption of glucose. Owing to increased fermentation of carbohydrates by gut bacteria, flatulence and diarrhea may develop. Miglitol has a similar effect but is absorbed from the intestine. 

Butanediol is a constituent of wine and an important neutral compound formed by yeast fermentation of carbohydrates. Saccharomyces cerevisiae produces mainly D(-)-2,3-butanediol and small amount of the meso form. Wines that had undergone malolactic fermentation contained traces of L(+)-2,3-butanediol which was absent from wines that had not undergone malolactic fermentation (Herold et al. 1995). 

Brevetoxin, a polyether neurotoxin produced by a single-celled organism that occurs in red tides (Opener, Section 9.5) Ethanol, a gasoline additive that can be produced from the fermentation of carbohydrates in grains (Section 9.5) The design of asthma drugs that block the synthesis of leukotriene, highly potent molecules that contribute to the asthmatic response (Section 9.16)... 

The fermentation of carbohydrates and protein are each no doubt mediated by more than one species of bacteria, and so the assumption that this occurs in a single step is a significant simplification. However, the fermentation of hydrogen and the various fatty acids by independent species of methane producing bacteria appears to be quite realistic. 

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