Subsystem matches in the nitrogen metabolism category. The proportional numbers of environmental gene tags that matched with level 2 sequences within the nitrogen metabolism subsystem category for the +NO3- (solid bars) and –N (open bars) metagenomes. No significant differences were found when these sequences were analyzed with Fisher exact tests in the Statistical Analysis of Metagenomic Profiles program.
Carrino-Kyker et al. BMC Microbiology 2013 13:78 doi:10.1186/1471-2180-13-78