EFFECT OF BENZYL ALCOHOL AND ETHANOL ON COLD-SHOCK RESPONSE OF BACILLUS-SUBTILIS

Benzyl alcohol and ethanol were found to exhibit an opposite effect on cold adaptation of Bacillus subtilis. The growth lag induced in bacte ria by temperature shift-down was reduced in the presence of benzyl al cohol from 80 to 58 min, whereas ethanol prolonged this interval up to 102 min. In parallel, the physical state of the cytoplasmic membrane in intact bacteria was examined with the help of steady-state fluoresc ence anisotropy of diphenylhexatriene. Benzyl alcohol decreased the an isotropy as a consequence of membrane fluidization whereas ethanol inc reased its value, suggesting membrane rigidization. The correlation of growth and fluorescence data indicates that the control of membrane s tructure represents an important part of bacterial adaptation to cold.