Biochemical, Biophysical and Physiological Characterization of an Ice-Active Substance Released by Sea Ice Diatoms

最近有研究表明，来自南极洲麦克默多湾的海冰片的硅藻会释放出一种富含蛋白质的冰活性物质，这种物质在自然浓度下会在正在生长的海冰片的基底表面产生密集的凹坑。目前，已知只有鱼、昆虫和细菌能产生冰活性物质。因此，与海冰藻类有关的冰活性物质是人们感兴趣的，因为它是第一个与藻类有关的物质，它可能为生物分子如何与冰相互作用提供新的见解。该项目的目的是生物化学，生物物理和生理特征的冰活性物质。在生物化学和生物物理水平上，目标是纯化冰活性物质，确定其化学成分和结构，并表征其对冰晶生长的影响。在生理层面上，目的是确定冰活性物质的藻类生产与环境之间的关系。更具体地说，麦克默多湾冰活性物质的时空分布是怎样的，它的产生是如何受到温度和光线的影响的，它存在于哪些物种和栖息地中？该项目的长期目标是了解冰活性物质在海冰藻类群落中的作用。＊＊＊

9316736 Raymond Recently it has been shown that diatoms from sea ice platelets in McMurdo Sound, Antarctica, release a proteinaceous, ice-active substance that, at natural concentrations, causes dense pitting on the basal surfaces of growing ice platelets. At present, only fish, insects and bacteria are known to produce an ice-active substance. Thus, the ice-active substances associated with sea- ice algae are of interest because it is the first to be associated with algae, and it may provide new insights on how biomolecules interact with ice. The objectives of this project are to biochemically, biophysically and physiologically characterize the ice-active substance. On a biochemical and biophysical level, the objectives are to purify the ice-active substance, to determine its chemical composition and structure, and to characterize its effect on the growth of ice crystals. On a physiological level, the objective is to determine the relationship between algal production of ice-active substance and the environment. More specifically, what is the temporal and spatial distribution of the ice-active substance in McMurdo Sound, how is its production influenced by temperature and light, and among which species and habitats is it found? The long-term goal of project is to understand what role ice-active substances play in the sea-ice algal community. ***