Ice recrystallization is one of the primary mechanisms of cell death in freezing temperatures. While the small ice crystals can exist at the surface of cells without causing cell death, large ice crystals cannot. Large ice crystals, formed when the adjacent small ice crystals join together and align themselves in the same direction, act as knives to the cells. The large ice crystals are powerful enough to force their way in between cells and puncture the cells’ protective outer layer. The insides of the cells, when exposed to freezing temperatures, die. The extracellular ice-binding proteins prevent the large ice crystals from forming, and are thus essential for the growth and survival of sea ice diatoms embedded in ice.
This summary was contributed by Jennifer Lawrence.
"We show that the IBPs have strong effects on inhibiting the recrystallization of ice and on retaining brine in ice. Both these properties help preserve a liquid environment in ice, which is considered essential for survival for microbes embedded in ice." (Raymond et al. 2009:130)
"Diatom IBPs resemble plant antifreezes in that they do not appreciably lower the freezing point, which suggests that they mainly function as cryoprotectants." (Janech et al. 2006:410)