Sulphate and methionine as sulphur sources for cysteine and cephalosporin C synthesis in Cephalosporium acremonium

Three prototrophic strains of Cephalosporium acremonium with different potentials for cephalosporin C production show pronounced differences in pools of intracellular sulphur amino acids. The superior strain exhibits the largest pool, particularly of cysteine (four times that of the non-producing strain). In fermentations with this strain methionine was found to be a much better sulphur source than sulphate for both cysteine and antibiotic synthesis. In the presence of methionine the utilization of sulphate is strongly depressed.