Samples collected on days 79 and 112 displayed relatively low dissimilarity when comparing samples from the same reactor positions. The values ranged from 0.16 to 0.35, as indicated by the lighter colors along the main diagonal of the heatmap. On the same day, the community composition remained relatively uniform across the top, middle, and bottom reactor positions, with dissimilarity values ranging from 0.11 to 0.33 on day 79 and from 0.15 to 0.37 on day 112. This suggests that the stable conditions in R1 may have supported a relatively homogenous microbial community structure. This relative spatial consistency indicates a robust microbial population well-suited for CO conversion.