Fig. 1
From: Continuous sulfide supply enhanced autotrophic production of alcohols with Clostridium ragsdalei
Variation of pH profiles in autotrophic batch processes with C. ragsdalei in a continuously gassed STR. Cell dry weight (A CDW) and product concentrations (B acetate; D ethanol; E 2,3-butanediol), pH (C) and CO uptake rates (F rCO): final pH 6 (black diamonds, black lines), pH 5.5 (white circles, dashed lines), pH 5.0 (red triangles, red lines), and uncontrolled pH (blue squares, blue lines). The batch processes were operated at a temperature of 37 °C, working volume of 1 L, volumetric power input of 3.5 W L−1, initial pH of pH 6.0, and a gas flow rate of 5 NL h−1 with inlet partial pressure of 0.2 bar H2, 0.2 bar CO2, and 0.6 bar CO. Standard deviations are shown for the processes at pH 6.0, which were conducted in triplicate; CO uptake rates are shown without standard deviations