Fig. 1
Analysis of fermentation products and CoA-ester intermediates in C. kluyveri. A GC–MS analysis of fermentation broth from a culture of C. kluyveri revealed the presence of butyrate, caproate, and traces of butanol and hexanol. Ethanol and acetate were derived from the medium and 1,3-propanediol served as the internal standard. B A volume of 50 mL of a logarithmically grown C. kluyveri culture (OD600nm = 0.9) was collected by centrifugation and re-suspended in 500 µL of a quenching solution. The cell debris was removed by centrifugation and sterile filtration. CoA-esters (acetyl-CoA, butyryl-CoA, 3-hydroxybutyryl-CoA, hexenoyl-CoA, hexanoyl-CoA and 3-hydroxylhexanoyl-CoA) were measured by LC–MS/MS with octanoyl-CoA as the internal standard