NSF Postdoctoral Fellowship in Biology FY 2021: Integrating microbial dynamics into methane models for northern peatland and post-glacial lakes

该行动资助2021财年NSF生物学博士后研究奖学金，研究基因组，环境和表型之间相互作用的生命规则的综合研究。该奖学金支持将以创新方式对生活规则领域作出贡献的研究员的研究和培训。北部湖泊是大气中温室气体甲烷（CH4）的重要来源。随着北极变暖，湖泊的甲烷排放量预计会增加，导致冻结了数百年至数千年的土地（永久冻土）解冻，并将有机物质释放到湖泊中，这些有机物质可以被微生物消耗并转化为甲烷。微生物是湖泊甲烷排放的主要驱动因素。不同的微生物会在甲烷上留下不同的“指纹”（同位素特征）。这些指纹是全球甲烷模型的关键组成部分，用于追踪大气中甲烷的来源。然而，对于哪些微生物生活在北部湖泊沉积物中，以及微生物活动（甲烷产生）和相关的甲烷排放和指纹将如何随着变暖和永久冻土融化而变化，人们知之甚少。该项目将识别瑞典北部湖泊沉积物中存在的微生物，并测量微生物在不同解冻和温度条件下产生甲烷的活跃程度。这项研究代表着朝着改进全球甲烷模型迈出的关键一步，该模型可以预测年排放量并帮助为政策决策提供信息。该研究员还将通过指导该领域的本科生，并参与新罕布什尔州和瑞典北部的K-12教育活动，努力增加STEM的多样性。该研究员将测量CH4排放/特征、非生物条件，并从瑞典北部的两个湖泊中取样沉积物，对比永久冻土条件和可能产生不同CH4的微生物（产甲烷菌）。该研究员将使用16S rRNA基因扩增子测序分析沉积物的微生物组成（基因）和丰度。通过沉淀物孵育，研究员将利用元转录组测序技术评估产甲烷菌在温暖条件下的代谢活性（表型表达）。该研究员将利用来自瑞典北部环境的宏基因组组装基因组库来绘制代谢途径活性，并针对产甲烷菌中的特定代谢基因。最终，该研究员将建立一个统计CH4模型，将微生物动力学与CH4排放和相关同位素特征联系起来。该研究员将通过NSF BII涌现项目夏季研究所为早期职业研究人员培养指导、专业和研究技能，并将指导本科生涌现研究经验项目的学生。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2021, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment and Phenotypes. The fellowship supports research and training of the fellow that will contribute to the area of Rules of Life in innovative ways. Northern lakes are important sources of the greenhouse gas, methane (CH4) into the atmosphere. Methane emissions from lakes are expected to increase as the Arctic warms, leading to the thaw of ground that has been frozen for hundreds to thousands of years (permafrost) and releasing organic material into lakes, where it can be consumed by microbes and transformed into methane. Microbes are the key drivers of methane emissions from lakes. Different microbes leave distinct “fingerprints,” (isotopic signatures) on methane. These fingerprints are crucial components of global methane models and are used to trace methane in the atmosphere back to its source. However, little is known about which microbes live in northern lake sediments or how microbial activity (methane production) and related methane emissions and fingerprints will change with warming and permafrost thaw. This project will identify microbes present in lake sediments in northern Sweden and measure how actively microbes produce methane under different thaw and temperature conditions. This research represents a crucial step towards improving global methane models, which predict annual emissions and help inform policy decisions. The fellow will also strive to increase diversity in STEM by mentoring undergraduate students in the field and engaging in K-12 educational activities in New Hampshire and northern Sweden. The fellow will measure CH4 emissions/signatures, abiotic conditions, and sample sediment from two lakes in northern Sweden with contrasting permafrost conditions and potentially different CH4-producing microbes (methanogens). The fellow will analyze sediments for microbial composition (genes) and abundance using 16S rRNA gene amplicon sequencing. With sediment incubations, the fellow will assess the metabolic activity (phenotype expression) of methanogens under warming conditions using metatranscriptome sequencing. The fellow will leverage a library of metagenome-assembled genomes from environments in northern Sweden to map metabolic pathway activity and target specific metabolic genes in methanogens. Ultimately, the fellow will build a statistical CH4 model that links microbial dynamics to CH4 emissions and associated isotopic signatures. The fellow will develop mentoring, professional, and research skills through the NSF BII EMERGE project summer institute for early career researchers and will mentor students in the EMERGE Research Experience for Undergraduates program.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.