TABLE 3.
Biofilm formation by reference E. coli isolates in plant tissue extractsa
| Treatment | Avg ± variance density of crystal violet at OD590b
|
||||
|---|---|---|---|---|---|
| Sakai | ZAP1589 | JHI5025 | JHI5039 | MG1655 | |
| Sp. apoplast | 0.002 ± 0.001 (NS) | 0.011 ± 0.001 (NS) | 0.372 ± 0.007**** | 0.013 ± 0.000 (NS) | 0.001 ± 0.002 (NS) |
| Sp. leaf | 0.071 ± 0.000*** | 0.128 ± 0.001**** | 0.218 ± 0.034**** | 0.113 ± 0.001**** | 0.000 ± 0.000 (NS) |
| Sp. root | 0.173 ± 0.000**** | 0.148 ± 0.017**** | 0.179 ± 0.015**** | 0.126 ± 0.000**** | 0.013 ± 0.000 (NS) |
| Lt. apoplast | 0.000 ± 0.002 (NS) | 0.005 ± 0.000 (NS) | 0.125 ± 0.005**** | 0.001 ± 0.000 (NS) | 0.000 ± 0.000 (NS) |
| Lt. leaf | 0.000 ± 0.000 (NS) | 0.018 ± 0.001 (NS) | 0.151 ± 0.002**** | 0.007 ± 0.000 (NS) | 0.001 ± 0.000 (NS) |
| Lt. root | 0.008 ± 0.000 (NS) | 0.029 ± 0.001 (NS) | 0.066 ± 0.001 (NS) | 0.025 ± 0.000 (NS) | 0.000 ± 0.000 (NS) |
| RDMG | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.013 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
a
Biofilms were formed on polystyrene multiwall plates following incubation in spinach (Sp.) and lettuce (Lt.) extracts (apoplast, leaf, root) and rich defined MOPS medium with glycerol (RDMG) at 18°C for 48 h under static conditions.
b
P value summaries are provided per isolate for each extract type versus RDMG (NS, not significant [P > 0.05]; ***, P ≤ 0.001; ****, P ≤ 0.0001).