Microorganisms products/secondary metabolite

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. 

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. 

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). 

Allelopathy is defined as biochemical interactions between one plant or microorganism (alga, bacteria, or virus) and another plant through the production of chemical compounds - secondary metabolites (allelochemicals), which influence, direct or indirect, harmful or beneficial, plant growth and development (Rice 1984). Allelochemicals are present in almost all plants and in many tissues, like leaves, stems, flowers, fruits, seeds, roots, or pollen and may be released from plants into the environment by volatilization, leaching, root exudation, and decomposition of plant residues (Chou 1990). 

Natural products with industrial applications can be produced by the metabolism of living organisms (plants, animals or microorganisms). The most economically natural compounds produced by microorganisms, other than enzymes and recombinant proteins, are the low molecular weight primary and secondary metabolites. ... 

Microorganisms are extremely versatile chemists. The wide variety of structures among the relatively few compounds discussed here is testimony to that. There are several theories to explain the evolutionary advantage conferred by the synthesis of secondary metabolites. (It often seems that they serve primarily to enrich pharmaceutical companies.) Until recently, the idea that they conferred a competitive advantage upon the producing organism seemed reasonable, since most of the products that had been detected had antibiotic activity. 

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