Fig. 2

a Relative expression levels (normalized against C. thermocellum recA expression) of T. saccharolyticum pforA and ferredoxin. b, c Fermentation products of five C. thermocellum strains. Cultures were grown in 15 mL tubes with 5 mL of MTC-5 medium, with 60 ± 2 mM (~ 20 g/L) (b) or 151 ± 3 mM (~ 52 g/L) (c) initial cellobiose, for 72 h and 168 h, respectively, at 55 °C. Error bars represent one standard deviation (n = 3 for a and b, n = 5 for c)