Fig. 6

Redundancy analysis of microbial community and fermentation reactor performance. The percent variance explained by each axis is indicated in parentheses. The numbers within the plot indicate the day of sampling. Red numbers indicate time points in which stillage batch 1 was fed to the reactor, and green numbers indicate time points in which stillage batch 2 was fed to the reactor. Arrows indicate environmental factors related to community composition and the sum of individual genera within the bacterial community. These include the sum of propionic, valeric, and heptanoic acids (OCFA; p = 0.001), the sum of hexanoic, heptanoic, and octanoic acids (MCFAs; p = 0.001), and the total percentage of carbohydrates converted to fermentation products (carbohydrate conversion; p = 0.001)