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.