SG: Microbes promote ice formation in inland waters

最近的研究结果表明，在季节性冰盖形成的北部湖泊中，丝状硅藻（微小浮游生物）的存在可能有助于冰的形成。这个项目将探索这样一个想法，即这种生物冰核实际上促进了这些不能游泳的硅藻的招募，从它们夏天生活的湖泊沉积物到它们冬天生活的上面的冰。冰表面的底部对它们来说是一个有利的区域，因为穿过冰的光线照亮了硅藻；光线照射不到湖底。为了验证这一想法，硅藻在夏季和冬季的分布将在一系列湖泊中进行检查。谁或什么对冰成核负责，将通过常规显微镜和现代基因组测序来确定。目前还不清楚是硅藻本身造成了冰核，还是硅藻上生长的细菌造成了冰核。这也将被调查。最后，将调查这种冰成核活动的影响，看看是否可以开发出一种普遍适用于世界各地湖泊冰形成的模型。这是第一批研究微生物在淡水生态系统中冰盖形成中的作用的研究之一，之前的大部分工作都是在高纬度的海洋中进行的。该项目可以揭示浮游植物生命周期的一个新阶段，并有助于解释为什么它们有时会在冬季在湖泊中开花。硅藻上的相关细菌也可能从它们与浮游植物的联系中受益。这项研究的结果可能会改变关于冰对湖泊生物学的重要性的传统观念。拟议研究的更广泛影响将包括与美国国家科学基金会（NSF）项目的合作，该项目名为“与STEM一起演进”。冰雪覆盖的湖泊、溪流和河流对俄亥俄州西北部的学生来说是独一无二的熟悉，尽管大多数学生可能没有意识到，即使在冬天，它们也很活跃。evolve的一个主要特点是将学生整合到一个公民科学项目中，该项目涵盖了两个当地学区的课程。通过该协会，该项目将包括中学教师作为合格数据收集者，作为俄亥俄州可信数据计划的一部分。在老师的指导下，学生们将通过季节采集样本进行水质分析，并在冬季直接接触湖泊的活力。

Recent results suggest that ice formation in northern lakes, where ice cover forms seasonally, may be assisted by the presence of filamentous diatoms (microscopic plankton). This project will explore the idea that such biological ice nucleation actually facilitates recruitment of these diatoms, which cannot swim, from lake sediments where they live through summer up to the overlying ice where they live in winter. The bottom of the ice surface is a favorable zone for them because of the light that penetrates the ice and illuminates the diatoms; that light doesn't reach the lake bottom. To test this idea, the distribution of diatoms in summer and winter will be examined across a range of lake sizes. Who, or what, is responsible for ice nucleation will be determined using both regular microscopes and modern genome sequencing. It is unclear whether the diatoms themselves are responsible for ice nucleation, or if it might rather be the result of bacteria growing on the diatoms. This will also be investigated. Finally, the implications of this ice nucleation activity will be investigated to see if a model can be developed that is generally applicable to ice formation in lakes around the world. This is one of the first studies of the role of microbes in the formation of ice cover in freshwater ecosystems, with most previous work done in high latitude oceans. The project could uncover a new stage of the life cycle of phytoplankton and help explain why sometimes they bloom in lakes during winter. The associated bacteria on the diatoms may also benefit from their association with the phytoplankton. Results of this study may change classical thinking about ice as important to lake biology. The broader impacts of the proposed research will include a partnership with the NSF program called iEvolve with STEM. Ice covered lakes, streams and rivers are uniquely familiar to students in northwestern Ohio, although most students probably do not realize that they are lively, even in winter. A central feature of iEvolve is the integration of students in a citizen science program that reaches across the curricula of two local school districts. Through this association, the project will involve middle school teachers as Qualified Data Collectors as part of the Ohio Credible Data Program. Under teacher supervision, students will collect samples for water quality analysis through the seasons and be directly exposed to the vitality of lakes in winter.