Bacillus polymyxa Polymyxins

Aspergillus sclerotiorum Huber Oxamniquina Bacillus lentus Dasoximatasona Diflucortolona valarata Bacillus polymyxa Polymyxin... 

The polymyxins are a group of antibiotics produced by Bacillus polymyxa. Polymyxin B (Aerosporin) and co-Ustin (polymyxin E, Coly-Mycin) are used in the treatment of bacterial diseases. 

A culture of Bacillus polymyxa in a tube with Trypticase soybean broth was incubated overnight at 25°C. 5 ml of this culture was transferred to 100 ml of the tank medium in a 500 ml Erlenmeyer flask which was incubated for 48 hours at room temperature. This 100 ml culture served as inoculum for one tank. During the course of fermentation the medium was aerated at the rate of 0.3 volume of air per volume of mash per minute. The temperature was maintained at about 27 C. Samples of mash were taken every 8 hours in order to determine pH and the presence of contaminants and spores. After 88 hours of fermentation the pH was about 6.3 and an assay using Escherichia coll showed the presence of 1,200 units of polymyxin per cubic centimeter. The polymyxin was extracted and purified by removing the mycelia, adsorbing the active principle on charcoal and eluting with acidic methanol. 

Polymyxin B Bacillus polymyxa Gram-negative bacteria Cell membrane... 

Polymyxines Polymyxines are a gronp of related polypeptide antibiotics that are produced by sporo-forming soil bacteria Bacillus polymyxa and B. circulans, and they differ in amino acid content. Five different polymyxines have been identified—polymyxines A, B, C, D, and E, which differ in the amino acid content and are differentiated by additional letter notations and names— polymyxine B (aerosporin) and polymyxine E (colistin). It is known that in the process of development, some strains of B. polymyxa only form polymyxines A and C, and others synthesize polymyxines B and D. Polymyxine M was later isolated, a snlfomethyl derivative of polymyxine E. 

Colistin (COL) is a multicomponent antibiotic (polymyxins E) that is produced by strains of inverse Bacillus polymyxa. It consists of a mixture of several closely related decapeptides with a general structure composed of a cyclic heptapeptide moiety and a side chain acetylated at the N-terminus by a fatty acid. Up to 13 different components have been identified. The two main components of colistin are polymyxins El and E2 they include the same amino acids but a different fatty acid (216). A selective and sensitive HPLC method was developed for the determination of COL residues in milk and four bovine tissues (muscle, liver, kidney, and fat). The sample pretreatment consists of protein precipitation with trichloracetic acid (TCA), solid-phase purification on Cl 8 SPE cartridges, and precolumn derivatization of colistin with o-phthalaldehyde and 2-mercaptoethanol in borate buffer (pH 10.5). The last step was performed automatically, and the resulting reaction mixture was injected into a switching HPLC system including a precolumn and the reversed-phase analytical column. Fluorescence detection was used. The structural study of El and E2 derivatives was carried out by HPLC coupled with an electrospray MS. Recoveries from the preseparation procedure were higher than 60%. 

Polymyxin B Bacillus polymyxa R-Dab-Thr-Dab-Dab-Dab-(D) Phe-Leu-Dab-Dab-Thr (Dab is diaminobutyric acid) Cyclic lipopeptide 1.8 26 (59-61)... 

Resistance to polymyxins. The polymyxins (A, B, C, D, E) are a group of antibiotics obtained from Bacillus polymyxa [145]. Polymyxin E is referred to as colistin. These antibiotics are extremely active against strains of Ps. aeruginosa but have the disadvantage of certain toxicity problems. The action of polymyxin is on the cytoplasmic membrane involving the phopholipid components [65,146]. 

The polymyxins are antibacterial agents that are produced from different strains of Bacillus polymyxa. Because of their poor tissue distribution and their substantial nephrotoxicity and neurotoxicity, they are mainly restricted to topical use. However, they can be considered for serious systemic infections caused by multidrug-resistant Gram-negative bacteria (1-4). 

Polymyxins are antibiotics produced by the bacterium Bacillus polymyxa. They are protein derivatives having one end that is hydrophobic because of an attached fatty add. The opposite end is hydrophilic. Because of these properties, the polymyxins bind to membranes with the hydrophobic end embedded within the membrane, while the hydrophihc end remains outside the cell. As a result, the integrity of the membrane is disrupted, and leakage of cellular constituents occurs, causing cell death. 

Polymyxin. Antibiotic complex produced by Bacillus polymyxa Brownlee, Jones, Biochem. J. 43, XXV... 

The polymyxins are a group of closely related antibiotics elaborated by various strains o/Bacillus polymyxa. Colistin is produced by Bacillus colistinus. These drugs, which are cationic detergents, are basic peptides of 1000 Da. 

Polymyxins, fatty acid-containing, branched cyclic peptides produced by Bacillus polymyxa possessing antibiotic activity against Gram-negative bacteria. The structure of polymyxin Bi is shown as a member of this peptide group. The basic sequence of polymyxins consists of... 

The polypeptides include bacitracin A, colistin (polymyxin E), novobiocin, and polymyxin B. Bacitracin is a complex mixture of branched, cyclic decapeptides produced by Bacillus subtilise, which was first isolated in 1945. The polymyxins, discovered in 1947, are synthesized by various strains of Bacillus polymyxa. Colistin (polymyxin E) comprises a family of polymyxins and was known as colimycin when first isolated from a broth of Bacillus polymyxa var. colistinus in 1951. The polymyxins are cationic detergents. Novobiocin, first reported in 1955 as streptonivicin, is produced by the actinomycete Streptomyces niveus. 

The polymyxins are a group of strongly cyclic polypeptide antibiotics which includes the colistins and circulins [129—131]. They are produced by Bacillus polymyxa and related organisms. Polymyxins are composed of a cyclic hepta-peptide moiety containing four molecules of diaminobutyric acid (DAB), one... 

Polymyxin B was first isolated from the bacterium Bacillus polymyxa in 1947. 

The discovery of antibiotic substances secreted by various strains of Bacillus polymyxa was simultaneously made in 1947 by Benedict and Langlykke (58) and by Stansly, Shepherd, and White (545). The latter workers, in particular, described the production and purification of a biologically active substance, which they named polymyxin. At almost the same time, Ainsworth, Brown, and Brownlee (16) announced the discovery of the production of a new antibiotic called aerosporin, by B. aerosporus, a species closely related to B. polymyxa. Later aerosporin was classified with the polymyxin group under the name polymyxin A. Actually, it appears that there are several polymyxins, each synthesized by different strains of B. polymyxa (326,327). A given strain, in general, synthesizes only one polymyxin (327). 

Paulus, H., and E. Gray The biosynthesis of polymyxin by growing cultures of Bacillus polymyxa. J. Biol. Chem. 239, 865 (1964). 

Bacillus polymyxa strain Pfizer 2459 was grown at 30° in shallow still cultures in the medium of Katznelson and Lochhead (1944) supplemented with 0.5 (xg per liter of biotin. Polymyxin was determined in the culture fluid after 36 hours (Paulus, unpublished). 

Cultures of Bacillus polymyxa ATCC 10401 were incubated with 29 xc of D- or L-leucine-i C, and the radioactivity in the 10,000 X g supernatant fraction of sonicated cells ( cell-free extract ), in polymyxin D from the culture fluid, and in the trichloroacetic acid insoluble fraction of cells ( protein ) was determined. (Calculated from data of Di Girolamo et al., 1964.)... 

Table 10. Polymyxin B production and sporulation in Bacillus polymyxa strain 612...

Brenner, M., E. Gray, and H. Paulus The relation of polymyxin B to the spore coat of Bacillus polymyxa. Biochim. et Biophys. Acta 90, 401 (1964). 

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