Fig. 6. Strong pulcherrimin producers and cells with significantly elevated DNA damage response in the biofilm appear to anticorrelate.

a Wild-type B. subtilis carrying the dual reporter P_recA-gfp and P_yvmC-mkate2 (LA233) was cultured in LBGM for pellicle biofilm development and fluorescence imaging was performed on samples collected after 48 h of development. A representative image for each fluorescence channel is displayed, as well as an overlay image of both GFP and mKate2. Arrows in cyan represent cells with high GFP and low mKate2 expression, while arrows in orange represent those with high mKate2 and low GFP expression. Scale bar, 10 μm. b Dot plot representing the distribution of cells according to their fluorescence levels for both reporters. Each dot represents a single cell. The green circle highlights the subpopulation of cells that display high fluorescence for the P_recA-gfp reporter and low fluorescence for the P_yvmC-mkate2 reporter. The magenta circle highlights the subpopulation with high P_yvmC-mkate2 and low P_recA-gfp activities.