Fig 1. Principle component analysis of S. aureus cytoplasmic amino acids following growth under the differing experimental regimes.

(a) PCA scores from the data were assessed for (A) control cultures grown under ideal conditions at pH7 and 37°C with no added NaCl; (B) centroid cultures grown at pH 7 and 37°C with 2.5% NaCl, and the four experimental groups: (C) 35°C and pH6 with no added NaCl; (D) 35°C and pH8 with no added NaCl; (E) 35°C and pH6 with 5% NaCl added; (F) 35°C and pH8 with 5% NaCl. (b) The PCA loadings p₁ and p₂ indicating the contributions of the amino acids to the cluster separations.