FIG 4.

Coculture of Fructobacillus sp. with honey bee-associated microbes. When honey bee-associated microbes are grown with Fructobacillus or with spent medium from Fructobacillus, they exhibit a growth advantage compared to growth alone. (A) Phylogeny and heat map of isolates used in a coculture interaction assay. The change in optical density from expected values was plotted as a heat map (yellow = more growth than expected; blue = less growth than expected). Lactobacillus and Fructobacillus isolates significantly increased the growth of a Firm-5 isolate. (B) Optical density measurements suggest that Firm-5 grows more robustly in Fructobacillus spent medium (SM) than in MRS medium (t = 11.196, df = 4, P < 0.001). (C) Difference in optical density corresponding to a dramatic difference in colony numbers when Firm-5 is grown on MRS plates postincubation for 48 h in MRS or SM (10⁶ dilutions of cultures plated in triplicate).