NMDS analysis of microbial community composition for the cross-feeding and desorption/cross-feed experiments. R and P values in each panel are results of ANOSIM of 16S rRNA gene amplicon dissimilarity. Results for reactors with different fluid sources are shown by the same symbol color because ANOSIM showed that fluid type did not significantly influence community composition (see Table 2). Different time points (days) are shown with the following symbols. For cross-feed 1: ○, 0; ♢, 14; △, 28; ▽, 35. For cross-feed 2: ○, 0; ♢, 7; △, 21; ▽, 35; □, 41. For desorption/cross-feed: ○, 0; ♢, 5; △, 19; ▽, 26.