Fig. 1

Schematic illustration of the experimental design. The microcosms were destructively sampled 34 days (a and b) or 35 days (c) after phage suspension inoculation. Soil suspensions from soil 1 (S1) and 2 (S2) were filtered to separate the phage fraction (PS1 and PS2) and bacterial fraction (BS1 and BS2). An outgroup with phage isolates named phage cocktail (PC) was also included. The different conditions were compared against a control made with autoclaved phage suspension (red cross) (PS1a, PS2a, and PCa). a During colonization experiment: both phage and bacterial suspensions were inoculated in microcosms made with sterile soil at the same time. b After colonization experiment: the bacterial fraction was inoculated first in the microcosms made with sterile soil, and the phage fraction was inoculated 28 days later. c Natural soils experiment: the phage fraction was inoculated in the microcosms made with the natural soils, 28 days after assembling the pots