Effects of temperature and nutrient concentration on the structural characteristics and removal of vegetable-associated Pseudomonas biofilm

The development of vegetable-associated Pseudomonas biofilms on polystyrene surfaces with different nutrient concentrations (trypticase soy broth; TSB, and 1:20 diluted TSB) was evaluated at 5 and 30 °C for up to 5 days. Biofilm structural characteristics were observed by confocal scanning laser microscopy (CSLM) before and after water-removal treatment. Before removal treatment, the bacterial counts of biofilm at 30 °C were 0.5-1 logs greater than that at 5 °C throughout incubation. However, the detected cell counts of biofilm developed with diluted TSB were greater than that with TSB at both 5 and 30 °C. Although the difference in the structure of developed biofilm between TSB and diluted TSB was observed at 30 °C, it was not clear that the removal treatment affected Pseudomonas biofilm structure.

► Pseudomonas biofilms on polystyrene surface with diluted/fresh TSBs were evaluated. ► The biofilms developed under rich TSB were easy to be removed by water flow. ► The structure of developed biofilm was varied under different TSB at 30 °C. ► No obvious differences in the water removal efficiency were obtained.