Studies on Histoplasma Capsulatum and Similar form-Species. III. Effect of Hydrogen Ion Concentration

Abstract

SUMMARYThe results of the studies of the effects of the hydrogen-ion concentration of the medium upon the growth and sporulation of Sepedonium chrysospermum and Histoplasma capsulatum may be summarized as follows: 1. The optimum H-ion concentration may vary with the medium. Essentially, however, the optimum point for Histoplasma capsulatum is approximately 6.5 to 7.5 and for Sepedonium chrysospermum is approximately 6.5 to 7.0.2. Sporulation, for the most part, is correlated with maximum growth, and consequently is also influenced by the H-ion concentration of the medium.3. It was found that with the media used in the experiments, when the carbohydrate-amino acid balance was changed, corresponding changes were produced in the acidity of the substratum. Thus, when the ratio of carbohydrates to amino acids was 15 to 1.8 the medium remained relatively constant, whereas when the ratio was 16 to 0.24, the medium became definitely more acid.