Fig. 1.

Quantification of bioluminescent L. plantarum 423 Fluc and E. mundtii ST4SA Fluc. a Bioluminescence measured in cultures of L. plantarum 423 Fluc and E. mundtii ST4SA Fluc distributed in black 96-well microtitre plates. Means from six independent cultures (4 × 10⁹ CFU per culture) are shown with standard deviations, and the background from each strain has been subtracted from each respective measurement. Correlation between bioluminescent signals and bacterial cell numbers of (b) L. plantarum 423 Fluc and (c) E. mundtii ST4SA Fluc. Cultures of each strain were serially diluted in black microplates and the bioluminescent signals quantified using the IVIS and then correlated with CFUs. Log₁₀ averages of three cultures are plotted, with error bars indicating standard deviations. The logarithmic trendline and the correlation of determination (R²) between bioluminescence measurements and bacterial numbers of each strain are shown