Microflora Danica - The Microbiome of Denmark

The complexity and diversity of the microbial world is awe-inspiring, but also largely unknown. Hitherto, even ”simple” estimations of the number of species in the world have been difficult due to method and cost limitations. However, the continued developments in both sequencing technology and nanoliter downscaling of protocols, means that uncovering our surrounding microbial communities is now becoming feasible. In the project ”The Microbiome of Denmark” (Microflora Danica) we aim to analyze the microbial diversity in representative natural, urban and agricultural habitats (both soil, sediment and water) of the entire country. Denmark is an idealplace to perform such deep analysis as it is a relatively small country (≈43,000 km2), with welldefined borders, 99% of which is comprised of coastline. Additionally, Denmark has a broad range of well-described and documented natural and man-made habitats. The overall goals of Microflora Danica are: 1) Drive method developments that enable large scale sequencing projects 2) collect and analyze 10,000 samples across Denmark by shotgun metagenomics, 3) retrieve metagenome assembled genomes (MAGs) in selected samples for further metabolic reconstruction and visualization by FISH and fluorescence microscopy and 4) generate a reference database of nearperfect full-length 16S and 18S rRNA gene sequences from 1,000 diverse samples. Here we present our sampling design and initial results from this massive endeavor and invite researchers to use the unique dataset to answer country-scale questions within microbial ecology.