The Water Relations of Growth and Respiration of Salmonella Oranienburg At 30°C

Abstract

The influence of water activity (aw ) on growth, respiration, and Na and K content of cells during respiration has been studied for Salmonella oranienburg. Sucrose, glucose, glycerol, NaCI, and KCI were added to control aw' The organism grew in a glucose-inorganic salts medium at 0·97 a", when any of these solutes was used to adjust a,v, but at 0·96 aw only when glycerol was employed. Respiration was not inhibited in glycerol-adjusted solutions at am's at which the rate was very low in other solutes. When a", was controlled by sucrose or glucose, cells oxidizing glucose accumulated K but not Na. Accumulation of K was greatest at 0·975 aw In solutions of NaCI, accumulation of K was small and in glycerol solutions it was absent. The differences between glycerol and the other solutes tested are discussed.