Chlorophyllide, the Probable Precursor of a Growth Inhibitor

Abstract

WHEN investigating the production of growth substances by Chlorella vulgaris var. viridis, difficulties were met which were ascribed to a growth-inhibiting substance, possibly Pratt's ‘chlorelline’¹. Staphylococcus aureus proved to be a suitable test object for the growth inhibition. Small pieces of filter paper or agar slices containing concentrated and dried crude ether extracts of Chlorella were placed on agar plates seeded with bacteria. After 2–5 hr. of diffusion of the extract, and incubation of the bacteria at 37° C., clear inhibition zones were visible around the filter paper or agar slices.