Fermentation processes, plant

Dlterpenes. Diterpenes contain 20 carbon atoms. The resin acids and Vitamin A are the most commercially important group of diterpenes. GibbereUic acid [77-06-5] (110), produced commercially by fermentation processes, is used as a growth promoter for plants, especially seedlings. 

Ephedrine and pseudoephediine are a vasodilator and decongestant respectively used widely in the treatment of asthma and the symptoms of colds and influenza. These pharmaceuticals were derived originally fi om the plant Ephedra sinica and used in traditional Chinese medicinal preparations. Although some are still produced fi om such sources, the major production is via a fermentation process followed by a chemical catalytic reaction. As shown in Figure 1, the intermediate / -phenylacetylcarbinol (PAC) is produced by decarboxylation of pyruvate followed by ligation to benzaldehyde. 

In the interdisciplinary field of biophysics and biotechnology, the bioeffects of electric field have received considerable interest for both fundamental studies on these interaction mechanisms and potential application. However, the effects of pulsed electric field (PEF) on secondary metabolism in plant cell cultures and fermentation processes have been unknown. Therefore, it would be very interesting to find out whether PEF could be used as a new tool for stimulating secondary metabolism in plant cell cultures for potential application to the value-added plant-specific secondary metabolite production. Furthermore, if the PEF permeabilization and elicitation are discovered in a cell culture system, the combination of... 

However, if the raw materials are contaminated or the composting process is incomplete, unfavorable effects must be expected. Heavy metals may be introduced into the compost with communal waste. To ensure that these do not enter the food chain, authorised limit values must be strictly adhered to. The same is true of organic contaminants (particularly polyaromatic or chlorinated hydrocarbons), the effect of which is extremely complex. If the fermentation process is not satisfactory, putrefaction will occur, the by-products of which (S02, NH3, N02, organic acids, cadaveric alkaloids, etc.) inhibit plant growth and attract pests. 

The alternative pathway is the biochemical route. It processes starches/sugars into ethanol, a standard technology with installations world-wide, but in a biorefinery the start is the whole-plant material or biomass residues containing hemicel-lulose, which is broken into sugars that then can be fermented to ethanol and/or other alcohols such as butanol. As mentioned before, there is the need to develop novel and/or improved biocatalysts for alternative organic fuels, such as biobutanol, by fermentation processes. 

Improvement of microbial strains for the overproduction of natural metabolites has been the hallmark of all commercial fermentation processes. Therefore, the aim of this chapter is to highlight several aspects of process improvement to yield natural products for industry at the laboratory, pilot plant and factory scales. 

Overproduction must be achieved in the laboratory before pilot plant scale-up is attempted. Thus, following the successfiil laboratory development of improved strains, a mastery of the fermentation process for each new strain, as well as sound engineering know-how for media optimization and the fine-tuning of process conditions are required to yield integrated and... 

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