Carbon dioxide, cocarboxylase, citrovorum factor, and coenzyme A as essential growth factors for a saprophytic treponeme (S-69).

A chemically defined medium was described in a previous paper (1) which, when supplemented with crystallized serum albumin, permitted sustained growth of the Reiter treponeme. When an attempt was made to cultivate other saprophytic strains of Treponema pallidurn on this medium, a number failed to grow. One of these strains, S-69,’ could be cultivated if the synthetic medium were supplemented with small amounts of brewers’ thioglycolate medium and whole blood. As will be here shown, the whole blood supplement was replaceable by CO2 and cocarboxylase, and the thioglycolate mixture by sodium pyruvate, citrovorum factor, and coenzyme A. These five substances, added to the chemically defined Reiter medium, support the growth of the S-69 treponeme.