Fig 2. Higher diversity of gut bacterial communities in wild-caught Drosophila melanogaster.

Bacterial OTUs present in the gut of laboratory (1–20) and wild-caught (21–40) flies before (Day 0) and after being exposed to the stability protocol (Day 10). Gut homogenates from flies represented in Fig 1B and 1E were plated in different culture media, and representative colonies of each morphological type were sequenced. Each column represents one individual gut. Bacterial levels are represented on a gray scale from 10⁰ to 10⁷ CFUs per gut. Colonies of different Lactobacillus, Acetobacteriaceae, or Enterobactereaceae were not possible to distinguish by morphological type and are grouped together. The presence of Lactobacillus species and Leuconostoc pseudomesenteroides in wild-caught flies is not independent (Pearson’s chi-squared test, p = 0.014). Frequencies of the different OTUs in these groups are represented on Fig 3B, 3D, 3F and 3H and S3B Fig. Supporting data can be found in S6 Data. CFU, colony-forming unit; OTU, operational taxonomic unit.