Phylogenetic trees of a) NanK and b) NanE. The trees were obtained using Bayesian analysis as implemented in MrBayes. 1,000,000 generations were used to build the consensus trees. Only confidence values below 85 are shown. Blue Operational Taxonomic Units (OTUs) indicate Gram-negative Bacteria; red OTUs, Gram-positive Bacteria; black OTUs, Eukaryotes. Blue branches indicate Gamma-proteobacteria; red branches, Firmicutes; Black branches; Eukaryotes.