Use of Certain Growth-Inhibitors as Tools in Metabolic Investigations

CULTURES of Saccharomyces carlsbergensis grown in the presence of sub-optimal amounts of vitamin B6, biotin, or pantothenic acid, and containing in each case less than one tenth of the normal quantity per mgm. of the growth-factor, possessed reduced rates of fermentation, which could be increased within a few minutes at most by addition of the latter. A rapid and marked stimulation was produced also by the addition of sodium azide in suitable concentrations ; typical results are shown in the accompanying figure.