Antibiotic producing organisms

Antibiotic Producing organism Yea/ Company or Institute Refs. 

Penicillins. Since the discovery of penicillin in 1928 as an antibacterial elaborated by a mold, Penicillium notatum the global search for better antibiotic-producing organism species, radiation-induced mutation, and culture-media modifications have been used to maximize production of the compound. These efforts have resulted in the discovery of a variety of natural penicillins differing in side chains from the basic molecule, 6-aminopenici11anic acid [551-16-6], These chemical variations have produced an assortment of dmgs having diverse pharmacokinetic and antibacterial characteristics (see Antibiotics, P-lactams). 

Antibiotic Producer organism Activity Site or mode of action... 

The clinical introduction of the penicillin group of antibiotics prompted an intensive search for novel antibiotic-producing organisms and Selman Waksman demonstrated the value of actinomycetes in this role, discovering the aminoglycoside streptomycin (81) from Streptomyces griseus in 1943 (126). Pharma-... 

Antibiotic Producer Organism Weight Extra or Intracellular ... 

Antibiotic Producing Organism Activity Structure Reference... 

Assume you have an antibiotic-producing organism. See if you can list some approaches that may enable you to use die same organism to produce a range of different, but related antibiotics. 

Antibiotic Producing organism Resistance gene(s) Mechanism of resistance Reference ... 

Cundliffe E. How antibiotic-producing organisms avoid suicide. Annu Rev Microbiol 1989 43 207-233. 

For the most part, the antibiotic industry uses batch-type processes. The reason for this stems from the fact that most efficient antibiotic-producing organisms are highly mutated and are readily replaced by fastgrowing, less efficient antibiotic producers in a continuous culture. In order to avoid substrate repression or inhibition, some batch processes are continuously fed concentrated substrate on demand during the course of the batch cycle. This is referred to as a batch-fed fermentation. The production of bakers yeast is an example of a batch-fed process. In some highly mycelial antibiotic fermentation, 20 to 40 percent draw-off followed by fresh media makeup is practiced. In the trade, this is referred to as a repeated draw-off process. Strict continuous processes are practiced only in processes for the production of biomass for feed or food and the treatment of wastes. 

A discussion of the detailed mechanism of polymyxin biosynthesis will have to await the isolation of enzyme systems that can mediate this process in vitro. However, the more general aspects of polymyxin synthesis, such as the relation of antibiotic synthesis to protein synthesis and the nature of the precursors of the peptide, can be discussed in the light of experiments carried out with growing cultures of the antibiotic producing organisms. 

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