Figure 2. Relative abundance at phylum level for each sample incubated under six different storage conditions.

Storage conditions that differed significantly from the control (−80 °C) are indicated with respective phylum abbreviation and asterisks. The respective phyla were abbreviated as follow: Actinobacteria (A), Bacteroidetes (B), Firmicutes (F), Proteobacteria (P) and Verrucomicrobia (V). Statistical significance was assessed by Mann-Whitney U-test and indicated by asterisks; single asterisk (*) represents p ≤ 0.05, double asterisk (**) represents p ≤ 0.01, and triple asterisk (***) represents p ≤ 0.001.