On May 26, 1987, vandals uprooted approximately 3,000 potato plants being studied with ice-minus bacterium on a half-acre site at a university field station near Tulelake, California.The uprooted plants were replanted and the test successfully continued.

Advanced Genetic Sciences, a pioneering agricultural biotechnology company headquartered in Oakland, California, sprayed Frostban on an acre of strawberry plants in Brentwood, CA, the previous April marking the first release of genetically altered bacteria in the U.S.

Ice-minus bacteria is a variant of the bacterium Pseudomonas syringae (P. syringae) that lacks the ability to produce a certain surface protein. The “ice-plus” nucleation-active protein (INA protein) found on the outer bacterial cell wall acts as the nucleating centers for ice crystals. The crystals facilitate ice formation, hence the designation “ice-plus”. The ice-minus variant of P. syringae is a mutant, lacking the gene responsible for ice-nucleating surface protein production, and protects the plants from below freezing temperatures.