Proflavine in the post-aerosolization plating medium lowered by over 80% the number of viable Escherichia colib/r organisms recovered from aerosols of 55% relative humidity (RH) and above, but had no effect on the recovery of viable E. coliwp2s organisms. Oxygen enhanced the lethal action of semi-dehydration on E. coli strain b/r, held at 50% RH and below, but had less effect on the survival of E. coliwp2s. In addition, E. colib/r organisms displayed an increased rate of respiration, and discharged 260 mμ absorbing material, when held at intermediate values of RH. These phenomena were not observed with E. coliwp2s organisms. Thus E. colib/r seems to possess an energy consuming mechanism by which it is able to survive semi-dehydration above 55% RH by a discharge of damaged cell components. This mechanism is very slowly destroyed when the organisms are semi-dehydrated in nitrogen but, below 50% RH, it is rapidly inactivated by oxygen. It is suggested that the mechanism is a membrane-bound system, possibly involving the cytochrome chain.
CoxC. S.1967; The aerosol survival of Escherichia colijepp sprayed from protecting agents into nitrogen atmospheres under changing conditions of relative humidity. J. gen. Microbiol 49:109
HillR. F.1965; Ultraviolet-induced lethality and reversion to prototrophy in Escherichia coli strains with normal and reduced dark repair ability. Photochem. Photobiol 4:563
KelnerA.1949; Photoreactivation of ultraviolet irradiated E. coli with special reference to the dose reduction principle and to ultraviolet induced mutation. J. Bact 58:511
WebbS. J.1960; Factors affecting the viability of air-borne bacteria. III. The role of bonded water and protein structure in the death of air-borne cells. Can. J. Microbiol 6:89
WitkinE. M.1963; The effect of acriflavin on photoreversal of lethal and mutagenic damage produced in bacteria by ultraviolet light. Proc. natn. Acad. SciU.S.A50425