Nitrogen fixation rates in a molybdenum-limited ferruginous meromictic lake

During the Archean and Proterozoic eras, diazotrophic organisms used the molybdenum-requiring nitrogenase enzyme to fix nitrogen to support early primary productivity, despite low availability of molybdenum prior to widespread oxygenation. Metagenomic analysis was done in Deming Lake, Minnesota, U.S.A., a ferruginous and meromictic lake with some chemical analogy to Archean oceans to determine nitrogen fixing organisms in a low molybdenum aquatic system. These data hope to resolve the apparent conundrum of molybdenum limitation on early Earth.