A sparse mapping of structure to function in microbial communities

The metabolic function of microbial communities emerges through a complex hierarchy of genome-encoded processes, from gene expression to interactions between diverse taxa. Therefore, a central challenge for microbial ecology is deciphering how genomic structure determines metabolic function in communities. Here we show, for the process of denitrification, that community metabolism is quantitatively predicted from the genes each member of the community possesses. For each strain in a set of bacterial isolates, the dynamics of nitrate and nitrite reduction are quantitatively encoded in the presence or absence of denitrification genes. We correctly predict metabolite dynamics in communities using a consumer-resource model that sums the contribution of each strain. Our results enable predicting metabolite dynamics from metagenomes, designing denitrifying communities and discovering how genome evolution impacts metabolism.