The linear fused tetracyclic structure of the tetracycline
molecule is weakly lipophilic [12]. This may have provided
a fluidization effect on the cytoplasmic membrane in B.
cereus. The strong fluidizing effect of the 50jC temperature
was observed in cells grown both in the absence and
presence of 1 Ag/ml tetracycline. Therefore, the fluidizing
effect of temperature may have overridden the effect of the
tetracycline at higher temperatures.