
Full text loading...
SUMMARY: The production of penicillin by Penicillium notatum in surface culture on a number of chemically defined media is described. Good results were obtained with media containing lactose, glucose, acetic, citric and phenylacetic acids, ammonium sulphate and inorganic salts. The yield of penicillin was raised by further addition of starch and an aliphatic base such as ethylamine. In the latter instance the penicillin yield was about the same as that obtained with media containing corn-steep liquor.
A suitable addition of mineral salts should include magnesium, potassium, iron, zinc, copper, manganese, cobalt, phosphate and fluoride.
The addition of starch and ethylamine increased the growth of the mould and produced crinkled felts similar to those obtained with corn-steep liquor. These media have a composition which is in many ways comparable with that of media containing corn-steep liquor, and it seems likely that corn-steep liquor owes its effectiveness to the fortuitous presence in it of several types of substances rather than to one substance.