Effects of Alcohols on Micro-Organisms

TLDR: The chapter concludes that the basic actions of alcohols on both eukaryotic and prokaryotic organisms share the same general principles.

Abstract: Publisher Summary This chapter reviews the effects of alcohols on microorganisms. Alcohols are ubiquitous small molecules, which are produced both chemically and as products of microbial fermentation. Accumulation of alcohols in the microbial environment represents a form of environmental stress, analogous to extremes in pH value and temperature. The chapter discusses the action of ethanol and other alcohols on microorganisms, explains several important mechanisms of action. Alcohols have been employed for many years both as a disinfectant and as a preservative. Concentrations of ethanol above 15% result in immediate inactivation of most vegetative organisms, with spores being considerably more resistant. Low concentrations of ethanol also render bacteria more sensitive to inactivation by ionizing radiation and by lipophilic acids. The chapter concludes that the basic actions of alcohols on both eukaryotic and prokaryotic organisms share the same general principles. These effects appear to be dominated by the physicochemical properties of alcohols rather than involving specific receptors. All hydrophobic and electrostatic interactions in the cytosolic and envelope components of cells can potentially be affected. These include membranes, conformations of enzymes and macromolecules, activity coefficients of metabolites, permitivity, ionization potentials, pK values of functional groups, and pH value.