Fig 1.

PCA was performed on 2nd-derivative and vector-normalized spectra in the spectral range of 1,200 to 800 cm⁻¹ recorded from the Reynolds CP5 strain and its isogenic capsule mutants CP8 and CP− grown at the following conditions: (i) TSA at 30°C and 24 h (red), (ii) TSA at 37°C and 24 h (green), (iii) TSA and 2% NaCl at 37°C and 24 h (yellow), and (iv) Columbia base and 2% NaCl at 37°C and 24 h (blue). PC1 was plotted against PC2. PC1 shows a distinct separation of the different growth conditions, whereas PC2 discriminates the Reynolds CP5, CP8, and CP− strains.