Fig. 4

Growth rate experiments. Bacterial colony sizes after 5 days at 30 °C. Boxplots indicate medians ± one quartile. The white section shows the growth rates on control media, and the coloured section shows the growth rates on the Pseudonocardia-infused media. Red boxes represent non-antibiotic-producer strains, and blue boxes represent antibiotic-producing Streptomyces strains. A linear mixed-effects model [100], including 17 Pseudonocardia strains and 20 inoculated bacterial species as random intercepts, was used to test for interaction and main effects of growth media (control vs. Ps1-infused vs. Ps2-infused) and antibiotic production (non-producers vs. producers): lme4::lmer(Growth score ~ Growth media × Antibiotic production + (1|Ps strain/Plate) + (1|In strain)). One non-producer strain (Staphylococcus epidermidis) grew more rapidly than all other strains (open triangle points), demonstrating the need to control for correlated residuals