Fig. 3. Cells in a biofilm increase the thickness of the cell wall.

a Scheme of the extra cytoplasmic cell wall synthesis pathway. Each step is performed by several genes represented in boxes. Colored squares inside boxes represent 24, 48, and 72 h sampling times, and the intensity of color shows the level of upregulation (green) or downregulation (red). Stars indicate confirmation of the behavior by iTRAQ results and cross indicate conflicting results. b Transmission electron micrographs of floating cells, biofilm cells and sporulating cells inside the biofilm structure. Measurements of the cell wall thickness was done with ImageJ Fiji software over 40 images and 300 measures around the edges of each cell, showing an increase of 33.4% in the thickness of biofilm and sporulating cells. Standard deviation SC < 0.01. Bars equal 200 nm.