Secondary metabolites production microorganisms

Biotechnological processes may be divided into fermentation processes and biotransformations. In a fermentation process, products are formed from components in the fermentation broth, as primary or secondary metabolites, by microorganisms or higher cells. Product examples are amino acids, vitamins, or antibiotics such as penicillin or cephalosporin. In these cases, co-solvents are sometimes used for in situ product extraction. 

To date, progress achieved clearly demonstrates the potential of cultured plant cells for secondary metabolite production. Use of concurrent immobilization/permeabilization procedures, as well as precursor and elicitor treatments, may open new avenues of increasing product yields and will consequently affect the economic aspects of plant cell culture in a positive manner. However, our understanding of the many biosynthetic pathways of desired secondary metabolites is incomplete and successful industrial scale plant cell culture processes are still limited. Results of research in the area of plant cell culture will increase our understanding of the biosynthesis of plant metabolites, enhance our knowledge of plant-microorganism or plant-plant interactions and can lead to entirely new products or product lines of desirable compounds currently not available to use. Such work can also lead to development of industrial scale production processes for products now produced and recovered by conventional methods. Also, the genetic variety of the 250,000 to 750,000 plant species available remains to be explored. Presently only 5 to 15% of these species have been subject to even... 

The enormous diversity of microorganisms is a factor that must be kept in mind for future drug development. Only a minor proportion of bacteria and fungi have been cultured or examined for secondary metabolite production. For example, only 5% of the total number of fungal species have been described. Of those described (69,000), only 16% (11,500) have been cultured. It has been estimated that 1 gram of soil contains 1000 to 10,000 species of undiscovered prokaryotes The extensively used concept of isolation of microbial strains fixim different geographical and climatic locations around the world still gathers support. ... 

Microorganisms that produce secondary metabolites generally undergo a period of logarithmic growth in which the synthesis of the secondary metabolite is negligible. When the culture enters the stationary phase, secondary metabolite production is often triggered. 

The widespread nature of secondary metabolite production and the preservation of their multigenic biosynthetic pathways in nature indicate that secondary metabolites serve survival functions in organisms that produce them. There are a multiplicity of such functions, some dependent on antibiotic activity and others independent of such activity. Indeed in the latter case, the molecule may possess antibiotic activity but may be employed by a producing microorganism for an entirely different purpose. Some useful reviews on secondary metabolism have appeared in recent years [23,47 -49]. Examples of marine secondary metabolites playing a role in marine ecology have been given by Jensen and Fenical [50]. 

Potentially, antibiotics should be produced in circumstances that permit growth of their producers. Such circumstances may be found in the soil, plants and plant materials (e.g., fruits), etc. Brian [17] advocated the competitive role of antibiotics against other species susceptible to their effects, and accumulated experimental data concerning the production of antibiotics and other secondary metabolites of microorganisms in natural environments. 

Secondary metabolites of microorganisms include antibacterial, antifungal, antiviral and antitumor agents, insecticides, pigments, inmunomodulators (including potent inmunosupressors) and a variety of other bioactive products (Davies 2007 Yim et al. 2007 Demain 2009). 

The held of marine natural products chemistry, which encompasses the study of the chemical structures and biological activities of secondary metabolites produced by marine plants, animals, and microorganisms, began in earnest in the early 1960s. " This is in stark contrast to the study of terrestrial plant natural... 

The underlying assumption driving marine natural products chemistry research is that secondary metabolites produced by marine plants, animals, and microorganisms will be substantially different from those found in traditional terrestrial sources simply because marine life forms are very different from terrestrial life forms and the habitats which they occupy present very different physiological and ecological challenges. The expectation is that marine organisms will utilize completely unique biosynthetic pathways or exploit unique variations on well established pathways. The marine natural products chemistry research conducted to date has provided many examples that support these expectations. 

Microorganisms have been identified and exploited for more than a century. The Babylonians and Sumerians used yeast to prepare alcohol. There is a great history beyond fermentation processes, which explains the applications of microbial processes that resulted in the production of food and beverages. In the mid-nineteenth century, Louis Pasteur understood the role of microorganisms in fermented food, wine, alcohols, beverages, cheese, milk, yoghurt and other dairy products, fuels, and fine chemical industries. He identified many microbial processes and discovered the first principal role of fermentation, which was that microbes required substrate to produce primary and secondary metabolites, and end products. 

I. PRODUCTION OF ANTIBIOTICS. The production of secondary metabolites with antimicrobial properties has long been recognized as an important factor in disease suppression (see Chap. 7). Metabolites with biocontrol properties have been isolated from a large number of rhizosphere microorganisms, including the fluorescent pseudomonads (Table 2). Further discussion is not given here since this is the subject of recent reviews (122,123). 

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