Figure Legends
Figure 1. Effect of temperature on biofilm formation in differentBurkholderia strains (B. pseudomallei 1026b Δasd ,
Bp82, JW270 and B. thailandensis E264). a. Biofilm formation life
cycle in B. pseudomallei JW270 b. Pellicle images ofBurkholderia strains. c. Image of a B. pseudomallei JW270
pellicle post processing vs micrograph image of the pellicle. Red lines
lead to an SEM image which shows that the pellicles are made up the
extracellular materials (eDNA, proteins and polysaccharides) and
bacterial cells. There was no difference in pellicle morphology on the
SEM. Bar 2µM. d. Crystal violet quantification of Burkholderiabiofilms under different temperatures shows that there is no significant
difference in biofilm formation at the end of the experiment -72 hours
(P > 0.05). e. Biofilm formation of all 4 strains at 37°C
after 72 hours shows that there is no significant difference between the
biofilms formed by B. pseudomallei strains or by B.
thailandensis , (P >0.05 for each comparison).
Figure 2. Microscopic images of Burkholderia biofilm. a. 10x
Microscopic images of 72 hours Burkholderia biofilms which shows
the biofilms are composed of eDNA (Dapi), proteins (Sypro ruby) and
polysaccharides (WGA) White bar - 200µm. Inserts are 100x Microscopic
images showing the cells within a biofilm. Red bar - 100µm. b. Live/dead
image of cells 0-48 hours showing that the cells are viable throughout
the biofilm process (Bar- 10µm).
Figure 3 shows that there is a significant difference between the
amounts exported when comparing between growth modes (p ˂ 0.05). As
expected, biofilm cells export higher amount of all constituents
compared to planktonic cells. In figures 3a -3c, we observe that 1026bΔasd and Bp82 export high levels of (a) protein and (b)
polysaccharide and low levels of (c) eDNA. JW270 biofilm on the other
hand show higher levels of eDNA and minimal protein and polysaccharide
export while B . thailandensis exports high protein and
eDNA and lower polysaccharide levels when compared with B.
pseudomallei 1026b Δasd and Bp82.
Figure 4. Effects of enzymatic treatments on 72 hoursBurkholderia biofilms. Data shows that there is a significant
difference between untreated biofilms and enzyme treated biofilm. (* = p
˂0.05, ** = p = 0.01-0.05, *** = p =0.01- 0.007).
Figure 5. Morphology and composition of Burkholderia pellicles.
a. Fluorescent images of a Burkholderia pellicles showing eDNA
(blue), Polysaccharides (green), Sypro ruby (red). b. Polysaccharide
(black bars) and protein (red line) compositions extracted from 72 hour
pellicles. c. Quantification of eDNA extracted from a 72 hour pellicle
and read using propidium iodide and a spectrophotometer. Bars represent
average of three independent experiment and Error bars represent SEM.
Figure 6. Comparison between 1026b, DD503, and JW270 biofilms. Graphs
a-c show concentrations of protein and glucose and eDNA levels
respectively. There is no significant difference between the protein and
eDNA of 1026b and DD503 at the end of the experiment, 72 hours (p
> 0.05) whereas DD503 and JW270 differed significantly at
each time point except the 48 hours eDNA concentration (p <
0.05). There is also a significant difference between the glucose
concentrations for all three strains.