TABLE 1.
COMSTAT analysis of E. coli ATCC 33456 biofilm structurea
| Medium or compound | No. of samples | Total biomass (μm3/μm2) | Maximum thickness (μm) | Substratum coverage (%) | Roughness coefficient | Avg diffusion distance (μm) | Surface-to-biovolume ratio (μm2/μm3) |
|---|---|---|---|---|---|---|---|
| LB medium | 10 | 1.5 ± 0.9b | 46.2 ± 5.7 | 34 ± 19 | 1.7 ± 0.2 | 0.02 ± 0.02 | 4.1 ± 0.7 |
| Cinnamaldehyde | 20 | 1.6 ± 0.7f | 18.3 ± 1.8d,f | 16 ± 5d,f | 1.5 ± 0.2d,e | 0.05 ± 0.03c,f | 2.0 ± 0.2d,f |
| Eugenol | 19 | 4.1 ± 2.8c | 22.2 ± 6.1d | 57 ± 19c | 1.1 ± 0.5d | 0.18 ± 0.18c | 2.8 ± 1.0d |
| Citronellol | 10 | 4.8 ± 2.0c | 28.5 ± 10.0d | 52 ± 18c | 0.9 ± 0.3d | 0.12 ± 0.09c | 3.5 ± 0.5 |
a
Biofilms were grown for 18 h in flow cells. Essential oil components were added at concentrations that resulted in 60% inhibition of the planktonic growth rate.
b
All values are means ± standard deviations.
c
Significantly greater (P < 0.05) than the corresponding value for the LB medium control.
d
Significantly less (P < 0.05) than the corresponding value for the LB medium control.
e
Significantly greater (P < 0.05) than the corresponding value for citronellol.
f
Significantlly less (P < 0.05) than the corresponding value for citronellol.