Figure 6.

PCA scores plots comparing the ¹H NMR spectra of ptcu-1_1.5 grown on media containing BCS (samples 1–5; blue) and CuSO₄ (samples 6–10; red). (A) Scores plot calculated using the full NMR spectra. Sample segregation by treatment is observed along PC2 with the ptcu-1_1.5 (BCS) samples appearing at the top of the plot. (B) Scores plot for spectra with the regions containing the BCS resonances removed. Removal of the BCS resonances reduces the degree of segregation by treatment. (C) Scores plot calculated using only the spectral regions containing the BCS resonances. Performing the analysis using only the regions of the spectrum that contain the BCS peaks increases the segregation of the samples by treatment and indicates that the BCS peaks are primarily responsible for the sample segregation in (A), as confirmed by the loadings (data not shown).