Bioprospecting for microbial products that affect ice crystal formation and growth

Abstract

At low temperatures, some organisms produce proteins that affect ice nucleation, ice crystal structure, and/or the process of recrystallization. Based on their ice-interacting properties, these proteins provide an advantage to species that commonly experience the phase change from water to ice or rarely experience temperatures above the melting point. Substances that bind, inhibit or enhance, and control the size, shape, and growth of ice crystals could offer new possibilities for a number of agricultural, biomedical, and industrial applications. Since their discovery more than 40 years ago, ice nucleating and structuring proteins have been used in cryopreservation, frozen food preparation, transgenic crops, and even weather modification. Ice-interacting proteins have demonstrated commercial value in industrial applications; however, the full biotechnological potential of these products has yet to be fully realized. The Earth's cold biosphere contains an almost endless diversity of microorganisms to bioprospect for microbial compounds with novel ice-interacting properties. Microorganisms are the most appropriate biochemical factories to cost effectively produce ice nucleating and structuring proteins on large commercial scales.

Microbial and Functional Diversity within the Phyllosphere of Espeletia Species in an Andean High-Mountain Ecosystem

“…however, if these bacterial communities are stable (51)(52)(53), and sampling at different months throughout the year could improve our capacity to discriminate between permanent and temporary phyllosphere residents. Despite this difficulty, the fact that the most abundant phyla and bacterial species are shared across plants suggests that there is a widespread "global" core community adapted to life in the phyllosphere.…”

Magnetic resonance diffusion and relaxation characterization of water in the unfrozen vein network in polycrystalline ice and its response to microbial metabolic products

“…In addition, NMR has untapped potential to provide unique data on the non-equilibrium thermodynamics [29] of interfacial freezing and crystal growth as a function of microscale concentration and thermal gradients during ice recrystallization [30], data of relevance to crystallization processes in chemistry and food sciences [31,32]. In biological applications such as cryopreservation, recrystallization is a significant problem to be overcome and there is interest in development of ice interacting proteins for inhibition of crystal growth [33].…”

Characterizing the internal structure of laboratory ice samples with nuclear magnetic resonance

“…Proteins with ice-interacting properties have been studied extensively in organisms such as fish, cold hardy plants and insects, with functions ranging from ice nucleation to antifreeze and recrystallization inhibition (Ewart and others, 1999;Zachariassen and Kristiansen, 2000). Less is known about microbial IBPs, but they are produced by sea-ice diatoms, snow mold and certain sea-ice bacteria, with potential implications for geophysical properties of icy systems (Christner, 2010).…”