Figure 2
From: The PAMPA datasets: a metagenomic survey of microbial communities in Argentinean pampean soils
Principal component analysis. (A) A total of 103 soil samples were analyzed by 16S rDNA/rRNA V4 amplicon sequencing. Sequences were clustered in OTUs at 90% similarity. Low abundance and infrequent OTUs were excluded from the analysis (see Additional file 1 for a detailed description of the filtering procedures). Datasets were normalized before PCA. (B) Differences among 16S rDNA and rRNA were evident in the first three axes of the PCA analysis. (C) A total of 30 soil samples were analyzed by metagenomic shotgun sequencing. Predicted peptides were annotated by BlastP against the NCBI database and the results assigned to categories in SEED Database. Low abundance and infrequent SEED categories were excluded from the analysis (see Additional file 1). Datasets were normalized before PCA. OTU, operational taxonomic unit; PCA, principal component analysis; rDNA, ribosomal DNA; rRNA, ribosomal RNA.