Ice crystallization by Pseudomonas syringae

Several bacterial species can serve as biological ice nuclei. The best char acterized of these is Pseudomonas syringae, a widely distributed bacterial epiphyte of plants. These biological ice nuclei find various applications i n different fields, but an optimized production method was required in orde r to obtain the highly active cells which may be exploited as ice nucleator s. The results presented here show that P. syringae cells reduce supercooli ng of liquid or solid media and enhance ice crystal formation at sub-zero t emperatures, thus leading to a remarkable control of the crystallization ph enomenon and a potential for energy savings. Our discussion focuses on rece nt and future applications of these ice nucleators in freezing operations, spray-ice technology and biotechnological processes.