its fluorescent emission at 428 nm. DPH is hydrophobic and
associates with the lipophilic tails of phospholipids in the
cytoplasmic membrane. Moreover, DPH does not disturb
the structure of the cytoplasmic membrane, is highly sensitive
and simple to use. The probe is excited with polarized
light and the emitted polarized light is measured in the same
plane as that of excitation, and also 90j to the plane of
excitation. The less freedom the probe has to rotate, the
more light it will emit in the same plane as the excited light,
and the less light will be emitted 90j to the plane of
excitation. Thus, a relationship between the amount of
polarized light emitted and the order or fluidity (membrane
polarization) of the membrane can be indirectly estimated
[6]. In previous research conducted in our laboratory, we
reported the cytoplasmic membrane polarization values of
Pseudomonas aeruginosa UG2 grown under randomized