GB765886A - A new antibiotic ristocetin and a method of producing same - Google Patents

Abstract

An antibiotic, ristocetin, is produced by growing Nocardia lurida NRRL 2430, or a mutant thereof, in an aqueous nutrient-containing medium under submerged aerobic conditions until substantial antibacterial activity is imparted to said solution and thereafter recovering the antibiotic from the fermentation broth. A temperature of cultivation of 22-32 DEG C. and preferably 24-28 DEG C. is employed. The medium contains a source of (a) carbon, e.g. sugars such as glucose, dextrose, fructose and cellobiose, sugar alcohols, e.g. mannitol, glycerol and animal and vegetable fats and oils such as lard oil (b) nitrogen, e.g. animal and vegetable meals, e.g. rolled oats and soybean meal; corn steep liquor, molasses, peptone, meat extracts and ammonium nitrate; (c) trace minerals, e.g. sodium chloride, potassium dihydrogen phosphate and calcium carbonate. An antifoaming agent may also be present. The antibiotic is recovered by treating the filtered fermentation broth with activated carbon, eluting with acidified aqueous organic solvent especially aqueous acetone at pH 3.0, removing the organic solvent, concentrating, adding methanol to precipitate impurities, evaporating to dryness, extracting first with hot absolute methanol and then with 50 per cent glycerol in methanol, and finally precipitating the antibiotic by the addition of methanol to the glycerol-methanol extract. The antibiotic is effective against many gram positive pathogenic micro-organisms which are resistant to such wide spectrum antibiotics as oxytetracycline; it contains carbon, hydrogen, nitrogen and oxygen; the sulphate has analysis of 50 to 53 per cent carbon, 5-6 per cent hydrogen, 3.5 to 5.0 per cent nitrogen, 0.8 to 2.0 per cent sulphur and 30-40 per cent oxygen; it is soluble in water, dilute acids and dilute alkalis; insoluble in methyl alcohol, ethyl alcohol, ether, dioxane, chloroform and glacial acetic acid; and, when subjected to standard paper chromagraphy tests, comprises a major fraction which fails to exhibit a significant rate of flow with solvent systems comprising (a) n-butanol saturated with deionized water; (b) n-butanol saturated with deionized water with 2.0 per cent p-toluene sulphonic acid added to a-butanol layer; (c) n-butanol saturated with deionized water and 2.0 per cent p-toluene sulphonic acid and 2.0 per cent piperidine added to butanol rich layer; (d) methylisobutyl ketone satured with deionized water; (e) methylisobutyl ketone saturated with deionized water containing 2.0 per cent p-toluene sulphonic acid; and others; it gives a strongly positive test for carbohydrate with anthrone reagent and a strongly positive test for reducing sugars after hydrolysis; is inactivated by treatment with 0.1N sodium hydroxide at a temperature of 100 DEG C. for four minutes followed by cooling and acidifying to approximately pH 2.0 with 0.1 N sulphuric acid.