Nouvel antibiotique

A new antibiotic designated aspartocin is produced by cultivating an antibiotic aspartocin-producing strain of the micro-organism streptomyces griseus var. spiralis especially S. griseus var. spiralis A.T.C.C. 13733 or of the microorganism streptomyces violaceus especially S. violaceus A.T.C.C. 13734 in an aqueous nutrient medium containing assimilable sources of carbon, nitrogen and inorganic salts under submerged aerobic conditions. Specified carbon sources are starch, sugar, molasses and glycerol. Specified nitrogen sources are proteins, protein hydrolysates, polypeptides, soybeanmeal, bactopeptone, amino-acids or corn steep liquor. Specified inorganic salts are those containing the cations and anions potassium, sodium, calcium, sulphate, phosphate, chloride or carbonate. Trace elements such as boron, molybdenum, and copper may be present. Cultivation at a temperature from 20 DEG C.-35 DEG C. for 24 to 240 hours is preferred. The antibiotic is isolated by filtering the broth and then extracting the residual mycelial cake with an aqueous solvent at pH 1-2 and/or 9-10 and precipitating or back extracting the aqueous extract into a water-immiscible or partially miscible organic solvent, e.g. butanol at pH 1-3. The butanol solution is concentrated, the antibiotic precipitated and the precipitate mixture stirred with acetone or petroleum ether and the precipitate removed by centrifugation. Calcium chloride or other alkaline earth metal salts may be added to the culture medium to produce the corresponding salt of aspartocin or to the butanol extract to act as a salting out agent. Aspartocin has the analysis C=53.58%; H= 7.58%, N=13.58%; S=0.36% and O=24.90;; [a ]25 DEG D=226.4 (c, 2.1% solution in methanol); no U.V. spectrum and an I.R. spectrum as shown in Figure with maxima at : 3.07, 3.45, 6.03, 6.53, 6.89, 7.15, 8.10 and 9.82 microns. On acid hydrolysis it gives D or L-aspartic acid, L-proline, L-valine, glycine and glutamic acid and it forms salts with acids and bases. The picrate, sodium, potassium and calcium salts are specified. It is a growth stimulant and may be used in poultry feeds (see Group I) and may be added to clothes as a bacteriostat (see Group VIII). Aspartocin is active against many micro-organisms including gram-positive bacteria, streptococcus C203, diplococcus pneumoniae SVI and staphylococcus aureus.ALSO:The new antibiotic arpartocin (see Group IV(b)) is added as a growth promoter to purified chick diets contai