Fig. 5
From: The microbiome as a biosensor: functional profiles elucidate hidden stress in hosts
Meta- analysis of selected pH and oxygen responsive genes. Publicly available (by JGI) subset of 160 environmental metagenomes with pH measurements, were screened. Box plot of gene counts in acidic pH (< 7), neutral (7–8), or alkaline (> 8) pH for a nqr operon (6 subunits), b Na-H antiporter operon (7 subunits), and cgyrB as control. Detailed pattern for each subunit is available in Figure S6, S7. Outliers are not displayed (1.5 × 0.25–0.75 quantiles). Significant differences in gene counts, by Wilcoxon rank sum test (Bonfferoni correction, P < 0.05), are marked in letter report (a–c) Oxygen measurements were available for a subset of 257 environmental metagenomes. In these metagenomes, the abundance of napA (d), napB (e) norBC (f), and nosZ (g) was compared to oxygen levels. hgyrB was used as control. All gene counts are in proportion to rpoB gene