Biofilm components significantly differ between strains and growth mode.
Using a previously established biofilm extraction protocol [46], we quantified the concentration of each biofilm component and compared it to the supernatant of planktonic grown bacteria. Microscopic analysis in Fig. 2 showed that different strains exported varying quantities of protein/eDNA/polysaccharides. In Fig. 3, we used BCA (protein), phenol-sulfuric acid (glucose/polysaccharide) and propidium iodide florescence (eDNA) to quantify the concentration of biofilm grown constituents compared to a planktonic grown culture. We observed that the amount of molecules exported was determined by growth method. Between all four strains, there was a significant difference in protein, eDNA or polysaccharide content if the cells were grown with agitation (planktonic) or statically (biofilm) (Supplemental data; Table S1-3). There is no significant difference in protein concentration between 1026b Δasd , Bp82 and E264, but all three significantly differed from JW270 (Supplemental data; Table S1-3). It was observed that JW270 and E264 biofilms are dominantly made up of eDNA unlike 1026bΔasd and Bp82 biofilms which showed higher polysaccharide and protein component. This finding was notable because 1026b Δasdand Bp82 produce CPS I, but JW270 and E264 do not [40, 47]. The results suggest that the inability of B. pseudomallei andB. thailandensis strains to produce CPS I for biofilm formation may be compensated by exporting more eDNA for biofilm biogenesis.