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

Kuhn, Mckenzie Ann, Pasadena CA

Investigators

Abstract

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.