Growth and pH manipulation correlate with ammonia release. Wild type Candida albicans SC5314, ssy1Δ/Δ (CaPM07), ssy1Δ/Δ + SSY1 (CaPM25) and ssy1Δ/Δ + STP2* (CaPM36) strains were grown at 37°C on yeast nitrogen base allantoin (allantoin present as nitrogen source) with 1% casamino acids at an initial pH of 4.0. The stp2Δ/Δ (SVC17) strain was included for comparison purposes.
A. Growth was determined by measuring the OD600 at indicated time points.
B. Aliquots of the cultures were used to measure the pH of the medium at the same time points.
C. Ammonia excreted as byproduct of amino acid catabolism was collected in an acid trap and quantified with the Nessler’s reagent. Graphs show mean and standard deviation from three independent replicates.