2.7. Disruption of pre-formed biofilms
Biofilm formation by L. monocytogenes, S. aureus and Salmonella
Enteritidis was performed as individual cultures and mixed
cultures. The 96 well polystyrene microplate was filled with 180 ml
of TSYE broth, inoculated with 20 ml of individual or mixed bacterial
suspension and incubated at 35 C for 24 h. Cell suspension was
removed and 180 ml of fresh TSYE broth and inoculum were added
and incubated for more 24 h. After 48 h of growth the cell
suspension was removed and the formed biofilm were added of
200 ml of surfactin (0.1% and 0.5% concentrations) or rhamnolipids(
0.25% and 1.0% concentrations) solutions. The effectiveness of
biosurfactants was verified after 2 h, 6 h and 12 h of contact with
the biofilms. The wells were washed three times with 200 ml of
distillated water and the adhered cells were quantified as described
above.