RAPID: Meta-genomic and Transcriptomic Investigation of Complex Organic Matter Degradation in Antarctic Benthic Sediments

南极洲西部是地球上变暖最快的地区之一。气候变化将导致海平面上升，也会改变区域水温和化学成分。这些变化将直接改变栖息在生态系统中的微生物。微生物是地球上最小的生命形式，但也是数量最多的。它们推动必需营养物质的循环，例如海洋沉积物中的碳和氮。通过这种方式，它们构成了支持更大、更复杂生命的食物链的基础。然而，我们不太了解不同的微生物群落如何分解南极洲的沉积物，这将影响这些水域的化学成分。这项研究将利用遗传和化学数据确定南极洲沿海陆架上的微生物群落如何降解复杂的有机沉积物。这些数据将识别群落中的物种、它们产生什么酶以及它们驱动什么化学反应。这项研究将产生更广泛的影响，因为数据将用于创建课堂活动，提高学生的数据分析和批判性思维技能。这些数据将用于研究生、本科生和 K-12 课堂。这项研究将为了解南极洲沿海陆架底栖沉积物中的微生物群落如何降解复杂的有机物提供遗传和酶学见解。目前对南极洲底栖微生物群落如何响应并降解复杂有机物的理解是支离破碎的。最近的研究表明，底栖微生物群落是由有机物的可用性决定的。然而，这些研究是观察性的，并没有直接检查社区功能。对南极西部海洋沉积物宏基因组数据的初步研究表明有机物降解的遗传潜力，但尚未收集功能数据。其他研究已经检查了酶活性或宏基因组潜力，但很少有人能够直接将两者联系起来。为了解决这一知识差距，本研究将利用宏基因组学和宏转录组学，并结合微观实验、酶测定和地球化学数据。它将检查来自罗斯海、布兰斯菲尔德海峡和威德尔海的南极微生物群落，以记录群落的酶活性和用于降解复杂有机物的基因之间的关系如何与沉积物分解相关。这些数据将扩展我们目前对微生物遗传潜力的了解，并提供对酶功能的深入了解，因为它与海洋沉积物中复杂有机物的降解有关。从而，它将提高我们对南极海水化学温度变化的理解。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Western Antarctica is one of the fastest warming locations on Earth. Its changing climate will lead to an increase in sea-level and will also alter regional water temperature and chemistry. These changes will directly alter the microbes that inhabit the ecosystem. Microbes are the smallest forms of life on Earth, but they are also the most abundant. They drive cycling of essential nutrients, such as carbon and nitrogen that are found in ocean sediments. In this way they form the foundation of the food chain that supports larger and more complex life. However, we do not know much about how different communities of microbes break down sediments in Antarctica and this will influence the chemistry of those waters. This research will determine how communities of microbes on the coastal shelf of Antarctica degrade complex organic sediments using genetic and chemical data. This data will identify the species in the community, what enzymes they are producing and what chemical reactions they are driving. This research will create broader impacts as the data will be used to create in-class activities that improve a student’s data analysis and critical thinking skills. The data will be used in graduate, undergraduate and K-12 classrooms. This research will provide genetic and enzymatic insight into how microbial communities in benthic sediments on the coastal shelf of Antarctica degrade complex organic matter. The current understanding of how benthic microbial communities respond to and then degrade complex organic matter in Antarctica is fragmented. Recent work suggests benthic microbial communities are shaped by organic matter availability. However, those studies were observational and did not directly examine community function. A preliminary study of metagenomic data from western Antarctic marine sediments, indicates a genetic potential for organic matter degradation but functional data was not been collected. Other studies have examined either enzyme activity or metagenomic potential, but few have been able to directly connect the two. To address this gap in knowledge, this study will utilize metagenomics and metatranscriptomics, coupled with microcosm experiments, enzyme assays, and geochemical data. It will examine Antarctic microbial communities from the Ross Sea, the Bransfield Strait and Weddell Sea to document how the relationship between a communities’ enzymatic activity and the genes used to degrade complex organic matter is related to sediment breakdown. The data will expand our current knowledge of microbial genetic potential and provide a solid understanding of enzyme function as it relates to degradation of complex organic matter in those marine sediments. It will thereby improve our understanding of temperature change on the chemistry of Antarctic seawater.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.