GB745208A - Improvements relating to the production of an antibiotic substance by a cephalosporium species - Google Patents

Abstract

Cephalosporin N, a penicillinase sensitive antibiotic active against both gram negative and gram positive bacteria and produced by Cephalosporium I.M.I. 49137, is produced in increased yield by fermenting a Cephalosporin-producing-microorganism in a nutrient medium containing sucrose and/or lactose, ammonium acetate and a source of organic nitrogen under aerobic conditions of submerged or surface culture at 22 DEG to 33 DEG C., and preferably pH 6.5 to 7.4. Preferably, the nitrogen content is 400 to 1600 mg./litre, the ammonium acetate 2 to 9 g. per litre and the sucrose and/or lactose 1 to 4 per cent of the nutrient medium. The preferred nitrogen source is corn steep liquor. Cephalosporin N is isolated from the clarified broth by (a) adsorption on buffered carbon at pH 6 to 6.5, followed by elution with aqueous acetone or aqueous water-miscible alkanol after first wetting the carbon with a water-immiscible solvent such as benzyl alcohol; and then (b) adsorption on alumina at 0 DEG to 10 DEG C. and pH 4.2 to 6.5, followed by elution by means of aqueous alkali or acetone, methanol, ethanol, propanol or methyl acetate. Further purification may be obtained by (a) counter-current distribution using a solution of an alkali metal citrate, e.g. sodium or potassium citrate and ammonium sulphate in aqueous alkanol, especially ethanol; (b) adsorption at 0 DEG to 4 DEG C. on an anion exchange resin followed by elution with a dilute acid; or (c) extraction from aqueous solutions at pH 2.5 to 3.5 by means of saturated aqueous solutions of phenol or its homologues, preferably in the presence of an organic tertiary base such as dimethylaniline, pyridine, lutidine, collidine, and 2,4,6-trimethyl pyridine. It is preferred to remove all trace metals such as copper, tin, lead and mercury from the water and solvents before use.