Figure 3.

Metabolomics revealed the tryptophan metabolism ability of lactic acid bacteria (LAB). (A) LAB species metabolize a variety of indole derivatives. The proportion of strains within a species that produce metabolites is indicated by the size of the circle. Different colors represent different species. (B–F) The concentrations of all tryptophan metabolites detected in the fermentation broth of different strains are shown by box plots. All data were collected by repeating three experiments and taking the average of the results. Tukey’s honestly significant difference test was used to exclude discrete points.