Fig. 6

The composition and structure of PCGs in seven habitats (deep sea, n = 6; eutrophic lake, n = 5; mangrove, n = 8; mariculture, n = 13; surface ocean, n = 6; permafrost, n = 9; WWTP, n = 8). Bar plots showed the abundance of total PCGs (a), alkaline and acid phosphatases (b), and phoA, phoD, phoX, and phnW (c). Pie chart showed the taxonomical distribution of PafA (d). NMD analysis showed the beta-diversity of PCGs in seven habitats (e). The two-tailed analysis of variance (ANOVA) was used to calculate the significant difference of PCG abundance among seven habitats, and P-values were corrected by Tukey’s multiple comparison tests. The enrichment of the PCGs within a habitat was tested by Fisher’ exact test, with the P-value further adjusted using the Bonferroni correction. The significant difference of PCG patterns among different habitats was performed using multi-response permutational procedure (MRPP) and analysis of similarity (ANOSIM) tests. Different letters (“a,” “b,” “c,” or “d”) and asterisk represent the significant difference among these seven habitats. *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001