Revealing the taxonomy and functional potential of urban soil microbiomes

Urbanization is a leading cause of global biodiversity loss, but its impact on soil microorganisms and biogeochemistry remains uncertain. To address this gap, we investigate urban soil microbiome composition using metagenomic sequences from the Global Urban Soil Environment Ecology Network (GLUSEEN). We seek to reveal (1) changes in taxonomic composition and functional potential and (2) ubiquitous (core) taxa and metabolisms across the urban soil microbiome. We hypothesize that soil taxonomic and functional diversity are correlated due to the unique selective pressures of the urban ecosystem, and that the potential for carbon, nutrient, and pollutant cycling is a key feature of the urban soil microbiome. We find that Baltimore soil microbiomes are distinct from all other cities, displaying the highest taxonomic and lowest functional diversity. Only 66.3% of taxonomic and functional composition is correlated across all cities, highlighting differing functional potential within similar soil microbial taxa. Metabolic processes involving carbon and nitrogen cycling are abundant, as well as xenobiotic degradation. Core urban microbiota include many common soil bacteria and methane- and nitrogen-cycling archaea. Understanding the predominant characteristics of microbial taxonomy and functional potential in urban soils will aid in understanding feedback between growing metropolitan areas and processes driving climate change. Sentence summaryTaxonomic and functional potential of global urban soil microbiomes are partially decoupled and reveal ubiquitous potential for contaminant cycling. Feature image O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=140 SRC="FIGDIR/small/592449v1_ufig1.gif" ALT="Figure 1"> View larger version (52K): org.highwire.dtl.DTLVardef@133e122org.highwire.dtl.DTLVardef@1019556org.highwire.dtl.DTLVardef@f36fc7org.highwire.dtl.DTLVardef@2f952e_HPS_FORMAT_FIGEXP M_FIG C_FIG