Fig. 4
From: Continuous sulfide supply enhanced autotrophic production of alcohols with Clostridium ragsdalei
Variation of sulfide feeding in autotrophic fed-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) and CO uptake rates (F rCO): no feed (C black diamonds, black lines), 0.1 mmol S L−1 h−1 (C blue squares, blue lines) and 0.05 mmol S L−1 h−1 (C red triangles, red lines). The fed-batch processes were operated at a temperature of 37 °C, working volume of 1 L, volumetric power input of 3.5 W L−1, pH 6.0, and a gas flow rate of 5 NL h−1 with an 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