Fig. 3.

Efflorescence, desiccation and high pH drive the airborne loss of viability of GAS. GAS % viability was compared for (a) different RH over time with mean (standard deviation) of n≥3 CELEBS measurements at 30 % RH and 50 % RH in droplets of MEM 2 % FBS; (b) RH at 30 s of levitation with individual CELEBS measurements in droplets of 10 g l^–1 NaCl at varying RH; (c) varying droplet composition with CELEBS measurement in 10 g l^–1 NaCl, 10 g l^–1 NaCl with 1 g l^–1 glucose and 2 % FBS (organic), MEM 2 % FBS and artificial saliva after 30 s of levitation at 30 % RH; and (d) varying salt and pH composition after 20 min of suspension in non-aerosolized bulk solutions of THY broth, 10 g l^–1 NaCl (labelled low salt) or 350 g l^–1 NaCl pH 7 (labelled high salt) at pH 7 or pH 11, with T0 indicating the concentration of the culture diluted and spread onto agar with no 20 min incubation step. In (c) and (d) each datapoint shows the % viability from a single measurement and the mean is indicated by central line with standard deviation error bars. Significance determined by Student’s t-test, where **P≤0.01, ***P≤0.001.