Biofilms formed by each Burkholderia strain is made up of eDNA, protein and polysaccharides and all components are exported by live cells.
From Fig. 1d, at the end of 72 hours, there was no significant difference between biofilms formed by cells at RT or 37°C hence all experiments were carried out at 37°C. We determined the constituents of biofilms formed by all four strains using fluorescent microscopy. In Fig. 2a, we observed that all four strains exported varying amounts of eDNA, protein, and polysaccharides contents to support its biofilm structure. Closer magnifications are inserted to show molecular distribution around cell aggregates.
Previous publications have shown that in some Gram-negative organisms, eDNA is generated through cell lysis [45]. However, as indicated in Fig. 2b, live/dead images of B. pseudomallei and B. thailandensis indicate that at 48 hours, a time point by which a mature biofilm has been formed, the cells within the biofilm are predominantly viable.