The cultural conditions for the growth of the specific microorganism must be such that the capsular polysaccharide is completely decomposed before any appreciable amount of free enzyme is released into the medium. This reduces to a minimum the decomposition of the specific substrate by the free enzyme. As a result, a larger part of the specific substance remains as a source of energy for the growing microorganism and less enzyme is lost through inactivation during the course of decomposition of the specific substrate.

A marked stimulation of growth and of enzyme production occurs when small amounts of yeast extract are added to the medium and when the cultures are incubated under conditions of increased aeration.

Special emphasis is placed upon the fact that, thus far, appreciable amounts of the specific enzyme have been obtained only when the capsular polysaccharide itself, or the aldobionic acid derived from it, was present in the culture medium.