Ice crystallization induced by silver iodide and bacteria in microsize droplets dispersed within emulsions
Water dispersed within a suitable oil medium shows 4OoC undercooling. Specific ice nucleating agents such as silver iodide or less known bacteria such as Pseudomonas syringae, have been found to reduce undercooling to a value depending on different parameters relevant to the emulsification process or to the pretreatment of the aqueous phase to be dispersed. Furthermore, it appears that when there is activity, it is lower than that observed for bulk samples. Sonication, filtration and ultrafiltration tests performed on bulk water bacterial samples show that the size of the active fragments ranges 0.006 pm to 0.2pm.