Figure 6

Taxonomic and functional breakdown of nitrogen cycling pathways. (a) Nitrogen cycling pathways and reactions assigned by PathoLogic. Arrow color indicates pathway, nitrate reduction I (denitrification) (brown), nitrate reduction IV (dissimilatory) (yellow), and intra-aerobic nitrite reduction (red). Grey numbers adjacent to arrows indicated number of reads assigned to the reaction in the DNA and RNA (RNA in parentheses). Overlapping circles indicate the distribution of reads across multiple pathways. (b) BLAST-based functional and taxonomic breakdown of reads assigned to reactions in given pathways as indicated by letters A-E. Function was determined by the top RefSeq BLAST hit, reported by the MetaPathways pipeline, and indicated by reaction arrows, with color corresponding to taxa or taxonomic group with known activity: taxa with nitrate and nitrite reducing activity (blue), nitrite oxidizing activity (green), and ammonia oxidizing activity (purple). Grey reactions indicate no reads for enzymatic activity were detected, only regulatory proteins that may be involved in gene expression regulation (*).