Fig. 7
From: Application of electric potential improves ethanol production from xylose by active sludge
NMDS and relative abundances analysis of OTU in different reactors. (a) Comparison of the bacterial community structures using NMDS plots based on the Bray–Curtis dissimilarity. The NMDS plots display two time points (0 and 150 h) and four potentials (− 0.058, + 0.242, + 0.542, and + 0.842 V vs. the standard hydrogen electrode). The different symbols and colors indicate different reactors and applied potentials. (b) Relative abundances of the classified bacterial families. The relative abundance was based on the proportional frequencies of sequences that could be classified at a 97% similarity level. The relative abundances of different families were obtained by triplicate DNA extraction from each sample