Table 3.
Evaluation of K. oxytoca M5a1 biofilm formation in the presence of indigenous expressed QQ-proteins.
| QQ protein (plasmid) | Biofilm thickness [μm] | P-value | Volume [μm3/ μm2] | P-value | Biofilm structure |
|---|---|---|---|---|---|
| none (wild type) | 41 ± 5 | – | 22 ± 3 | – | Compact 3D-biofilm with wavy structures |
| MBP (pMAL-c2X) | 44 ± 4 | – | 23 ± 4 | – | Compact 3D-biofilm with wavy structures |
| QQ-2 (pRS611) | 10 ± 1 | <0.0001 | 3 ± 1 | <0.0001 | Reduced cell adhesion |
| QQ-3 (pRS612) | 22 ± 2 | <0.0001 | 16 ± 4 | <0.0127 | Compact monolayer without wavy structures |
| QQ-4 (pRS613) | 17 ± 2 | <0.0001 | 9 ± 2 | <0.0001 | Compact monolayer without wavy structures |
| QQ-5 (pRS614) | 19 ± 3 | <0.0001 | 11 ± 3 | <0.0002 | Compact monolayer without wavy structures |
| QQ-6 (pRS615) | 19 ± 2 | <0.0001 | 12 ± 2 | <0.0001 | Compact monolayer without wavy structures |
| QQ-7 (pRS616) | 19 ± 2 | <0.0001 | 13 ± 3 | <0.0006 | Compact monolayer with few but multi-layered cell aggregates |
| QQ-8 (pRS617) | 12 ± 1 | <0.0001 | 6 ± 2 | <0.0001 | Reduced cell adhesion |
| QQ-9 (pRS618) | 25 ± 3 | <0.0001 | 13 ± 2 | <0.0003 | Compact monolayer without wavy structures |
| QQ-12 (pRS621) | 22 ± 1 | <0.0001 | 17 ± 3 | <0.0148 | Several layers of cells with areas without cell adhesion |
Flow cells were inoculated with 1.35 × 108 cells of K. oxytoca M5a1 expressing MBP-QQ-ORFs from plasmids. After 1 h, flow cells were flowed for 72 h at 30°C with 20 mL/h GC medium containing 30 μM IPTG. Biofilms were analyzed after 72 h in at least three biological replicates, each with two technical replicates (see Materials and Methods). Average values are depicted with ± standard deviations. Average thickness and volume of MBP control and QQ biofilms are significantly different (p < 0.02, unpaired t-tests).