Fig. 4

Metabolite profiles of the AWRP strain grown in various culture media with no buffering agent (top) or with the addition of 10 g L⁻¹ MES (bottom). Each culture was performed in triplicate using 125-mL serum bottles, and the headspace was charged at 150 kPa with a synthetic gas mixture (50% CO, 30% N₂, 10% CO₂, and 10% H₂). When MES was supplemented to the medium, final pH was adjusted to 6.0 by the addition of 1 N NaOH before sterilization