2.4.4. Effect of hydrodynamic shear force on bacterial adhesion
To estimate the effect of the hydrodynamic shear force on the bacterial
adhesion, the pre-formed biofilm on themembrane surfacewas exposed
to the different stirring rates, and the detached bacteria were
measured. After biofilm pre-formation using the same protocol as described
in Section 2.4.1 at 1.50 MPa of the TMP and 100 rpm of the stirring
rate, we continuously supplied 5-fold diluted FABmediuminto the
cell at 1.50 MPa of the TMP and at various stirring rates from 100 to
300 rpm. The bacterial concentration in the condensatewaterwasmeasured
by a pour platemethod to evaluate the bacteria detached fromthe
membrane surface due to the shear force caused by stirring. Briefly,
1 mL of condensate water was added to 27 mL of warm FAB medium
containing 1.5 g/L agar. The mixed solution was poured onto plastic
plates, cooled at room temperature, and solidified. The prepared plates
were incubated for 24 h at 30 °C, and the bacterial colonies on the plates
were then counted.