Environmental context determines antifungal capacity of probiotics.
Tested temperatures (14, 19, 22°C) significantly affected the production of bacterial metabolites in liquid media that could inhibit B. dendrobatidis (Bd; GPL isolate VMV 813) zoospore growth in a dose-dependent fashion (a = full strength metabolites, b = 1∶10 dilution). * indicates that Bd growth differed among metabolite temperature treatments (ANOVA, Bonferroni-corrected P's<0.05). (c) Representative replicates are shown of two isolates of Serratia plymuthica isolated from egg clutches of common midwife toads, Alytes obstetricans, grown on solid media under different temperature conditions. Filtrate from isolate 27 always inhibited growth of Bd, but filtrate from isolate 28 inhibited Bd growth at 18°C, and enhanced Bd growth at 25°C. Filtrate from sterile media (R2A agar supplemented with 1% tryptone) caused enhanced growth of Bd. Note that colony color can be an indication of antifungal metabolites such as prodiginines from red Serratia spp. , , but are produced only under certain growth conditions.