Extractive fermentation, chemicals

Extractive fermentations and biotransformations could be a good example of these. Also, combinations of chemical reaction(s) with separation could have a synergy effect for the production part of technology enhancing its rate and yield. 

Kondo, K., Otono, T. and Matsumoto, M. (2004) Preparation of microcapsules containing extractants and the application of the microcapsules to the extractive fermentation of lactic acid. Journal of Chemical Engineering of Japan, 37, 1. 

Chemical synthesis Natural product extraction Fermentation... 

Production of bulk chemicals. The production of solvents is normally characterized by a general inhibition phenomenon which has been mainly attributed to the changes in membrane permeability, or to the toxic effects on the metabolic pathway. Aqueous two-phase systems have been shown to be effective as media for the extractive fermentation of a number of solvents which include ethanol, acetone-butanol and acetic acid (3). Improved productivity has been achieved in most of the cases as compared to the conventional fermentations, which is significantly due to the elimination of product inhibition. However, there is an indication that changes in the microenvironment of the microbial cells due to the presence of non-metabolizable polymers could also contribute, in the initial phases, to the increased production. The addition of PEG and dextran to a growth medium, for instance, was shown to give increased initial ethanol yields, as a result of decrease in the chemical potential of water (8). 

Vinegar as it usually comes on the market contains 3 to 6 per cent acetic acid, 2.5 per cent total solids and. 3 per cent ash (mainly potassium salts). In addition there are other important chemical substances which give to vinegar its desirable flavor and aroma. These substances differ according to the methods and care of manufacture, also according to the source of the sugary extract which has been fermented, Chemically, acetic acid is the oxidation product of ethyl alcohol and is the second member of the fatty acid series. 

Anbarasan P, Baer ZC, Sreeknmar S, Gross E, Binder JB, Blanch HW, Clark DS, Toste ED (2012) Integration of chemical catalysis with extractive fermentation to produce fuels. Nature 491(7423) 235-239... 

Acetone and butanol, two important organic chemicals, are nowadays exclusively made by chemical synthesis. During the Second World War, however, a fermentation process was used in many countries for the production of a mixture of both. Some members of the Clostridium genus are able to transfer commeal and molasses into the desired mixture of these chemicals, the ratio of which is determined by the kind of raw material and the bacteria species used. The maximum overall concentration obtainable is 2%. The process was abandoned after the war in most countries but returned into discussion when oil prices increased in the 1970 s. It is not very likely that this process will be used again unless the technology is improved (immobilized biocatalysts, extractive fermentation) and raw material prices are favorable. 

There are thousands of breweries worldwide. However, the number of companies using fermentation to produce therapeutic substances and/or fine chemicals number well over 150, and those that grow microorganisms for food and feed number nearly 100. Lists of representative fermentation products produced commercially and the corresponding companies are available (1). Numerous other companies practice fermentation in some small capacity because it is often the only route to synthesize biochemical intermediates, enzymes, and many fine chemicals used in minor quantities. The large volume of L-phenylalanine is mainly used in the manufacture of the artificial dipeptide sweetener known as aspartame [22389-47-0]. Prior to the early 1980s there was httle demand for L-phenyl alanine, most of which was obtained by extraction from human hair and other nonmicrobiological sources. 

The therapeutically active dmg can be extracted from plant or animal tissue, or be a product of fermentation (qv), as in the case of antibiotics. Frequentiy, it is synthesized and designed to correlate stmcture with therapeutic activity. Pharmacologic activity is first tested on laboratory animals. When the results ate encouraging, physical and chemical properties are determined in the so-called preformulation stage, and analytical procedures are developed for quahty control (see Qualityassurance/qualitycontrol). 

C, chemical synthesis Enz, enzymatic synthesis Ext, extraction E, fermentation. Ref. 219. 

In 1878 the term enzyme, Greek for "in yeast," was proposed (8). It was reasoned that chemical compounds capable of catalysis, ie, ptyalin (amylase from sahva), pepsin, and others, should not be called ferments, as this term was already in use for yeast cells and other organisms. However, proof was not given for the actual existence of enzymes. EinaHy, in 1897, it was demonstrated that ceU-free yeast extract ("zymase") could convert glucose into ethanol and carbon dioxide in exactiy the same way as viable yeast cells. It took some time before these experiments and deductions were completely understood and accepted by the scientific community. 

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... 

The reliance of fossil fuels has been challenged by lower cost and renewable sources that are more environmentally friendly. The traditional chemical plant has met serious competition from green plants. Many monomers are now made via fermentation, using low-cost sugars as feedstock. Some of the commodity monomers are under siege by chemicals extracted from biomass. Monomer production has been expanded to include many more monomers from nature. 

Marigold petals are rich sources of xanthophyUs, mainly lutein esters. To increase the coloring power, chemical extraction of the colorant from flower meal is performed or a new enzymatic procedure is applied. It was shown that treatment with cellulases or mixed saprophyte microorganisms or solid state fermentation improved the xanthophyll extraction yield. ... 

The same methods (chemicals, enzymes, physical treatments) can be also applied on the cell wall materials not with the aim of extracting polysaccharides but with the aim of obtaining modified fibres. New properties concerning for exemple fermentability, ratio soluble/insoluble dietary fibre, hydration., can be obtained (1). 

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