Culture Media for Large-scale Production of Micrococcin

Summary: A number of media have been developed for the production of micrococcin. A satisfactory medium consists of corn steep liquor to 1800 mg. N/1. with an aqueous extract of dried autolysed yeast to 1800 mg. N/1., which gives titres of the order of 40–60μg. micrococcin/ml. in 3 days. A soluble yeast extract such as Marmite may be used in place of the dried autolysed yeast. Moderate aeration is required for good titres but initial pH is relatively unimportant, any value in the range 6·0–7·0 being suitable. The main energy source in sugar-free media is probably the aerobic oxidative deamination of amino-acids. An inoculum that has been pre-incubated gives better results than an inoculum used immediately after it has been prepared. The addition of various inorganic ions to the medium was tried without any detectable influence on titre.