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J B BATEMAN

Publications and source records attributed to J B BATEMAN.

18 recordsLinked to original sources
PubMed1963

RELATIVE HUMIDITY AND THE KILLING OF BACTERIA: THE SURVIVAL OF SERRATIA MARCESCENS DEHYDRATED BY CONCENTRATED GLYCEROL AND SUCROSE SOLUTIONS.

Bateman, J. B. (U.S. Army Biological Laboratories, Fort Detrick, Frederick, Md.) and F. Elizabeth White. Effect of relative humidity on the survival of Serratia marcescens in concentrated glycerol and sucrose solutions. J. Bacteriol. 85:918-926. 1963.-The effects of sucrose and glycerol upon the ability of Serratia marcescens to grow when restored to a normal medium after exposure to solutions of these substances were examined, with special attention to the prevailing thermodynamic activity of water in these solutions as a factor of supposed primary importance in influencing survival or death of cells. The data were notable for the absence of any zones of instability such as those found when the water activity is changed by exposure of washed cells to water vapor at controlled relative humidities (RH). The cells survived indefinitely at room temperature in concentrated sucrose solutions; in glycerol solutions of equilibrium RH values from 20 to 90, the first-order decay constants were about 0.03 to 0.1 hr(-1). These results, considered together with the contrasting phenomenon of narrow lethal humidity zones found in vapor-phrase equilibration experiments, were explained generally in terms of competitive interactions involving concentrated intrinsic and adventitious solutes, the cell water, and the organized structures of the cell, whose integrity was considered to depend ultimately upon the net effect of these various interactions.

Dehydration↗
PubMed1961

Relative humidity and the killing of bacteria. The survival of damp Serratia marcescens in air.

The viability of washed moist cells of Serratia marcescens after storage has been measured in relation to variations in the prior treatment of the cells and in conditions of storage. The factors considered were: (i) water content during storage; (ii) method of arriving at water content (partial drying in vacuum or freeze-drying and addition of water); (iii) presence or absence of air during storage. Increasingly rapid decay occurs as the water content at which the cells are stored is diminished from above 90% to 20 or 30% ("critical" water content). It occurs in presence or absence of air and it occurs whether the final water content is approached by removal of water from wet cells or by addition of water to freeze-dried cells. The rate of decay during storage at 20 to 30% water is somewhat diminished by the presence of air ("protective" effect of air). As the water content is further reduced to less than 10%, the stability of cells stored in a vacuum approaches that of wet cells. In presence of air the reverse is true: the stability decreases until at less than 1% water, the decay rate is about as great as at the "critical" water content ("toxic" effect of air). Particularly rapid decay of S. marcescens at the "critical" water content has escaped attention in aerosol studies because accurate control of relative humidity (RH) in this region, RH 94 to 99%, is virtually impossible in such studies. On the other hand, values of decay rates referred to measured water contents are quite unreliable in the 20 to 80% RH zone because the corresponding variation of water content is too small to measure reliably. Thus data of the kind reported in this paper cannot be directly compared to the published results of studies of air-borne bacteria, although they are relevant to the practical question of air-borne infection in humid atmospheres.

Aerosols↗