Study on Biological Ice Nucleation and Its Applications ——Situation and Prospect

It have been proved that 4 genera 23 species or varieties bacteria,4 genera 11 species or varieties fungi and a virus have ice nucleation activity. Bacterial ice nuclei are proteins,named ice nucleating proteins, coded by ice nucleating genes.Ice nucleating genes of 11 species bacteria have been cloned, sequenced and expressed in Escherichia coli.Ice nucleation activity of ice protein is very weak,ice protein is decorated and assembled into powerful active ice nucleation by lipids and carbohydrates. Fungal ice nuclei are possibly protein, it differs from bacterial ice nuclei in some basic characteristics. Bacterial ice nucleation activity is influenced by some factors,such as cell consistence, growth medium composition,incubation temperature,culture age and pH value, et al.Biological ice nuclei are important factors causing and increasing plant frost and freezing injury, and inducing plant disease. Treatments that reduce the numbers or the ice nucleation activity (or both) of ice nucleation active microorganisms on plant are effective in decreasing plant frost and freezing injury, and controlling plant disease.Biological ice nuclei are significant natural resources,it have been used in man made snow, refrigeration and diagnostic. It will be also wide prospective taking advantage of biological ice nuclei in preventing insect pests by accelerating insect body freezing.