FACTORS AFFECTING THE VIABILITY OF AIR-BORNE BACTERIA: II. THE EFFECT OF CHEMICAL ADDITIVES ON THE BEHAVIOR OF AIR-BORNE CELLS

Abstract

The effect on air-borne cells of single chemical compounds added to a bacterial suspension prior to atomization has been studied. It has been found that some amino acids, long chain protein degredates, some sugars and polyhydroxycyclohexanes can enhance the survival of air-borne cells. The ability of a compound to preserve viability during periods of desiccation has been found to be connected with the presence of an amino and/or secondary alcohol group. For maximal protection these groups need to be substituted onto a six-membered ring nucleus. The hydroxyl group has been found toxic if present on a benzene ring, but protective on a pyrimidine ring. Inositol was found to afford a large measure of stability to the air-borne cells and its stabilizing ability could be destroyed by urea and guanidine. It is suggested that compounds enhance survival by replacing water molecules in protein structure during desiccation through hydrogen bonding and so preserve the natural structure of the cellular proteins. Peaks in death rates at intermediate relative humidity levels have been found to be due to the presence of the added compounds.