Anaerobic reduction of ferulic acid to dihydroferulic acid by Wolinella succinogenes from cow rumen

Summary Ferulic acid(FA)-modifying microflora from the rumen of cows were acclimated in an FA-containing medium, in which aromatic compounds (dihydroferulic acid, homovanillic acid, carboxymethylphenol and vanillic acid) and volatile fatty acids (acetic, butyric and isobutyric) were detected by gas chromatography and mass spectrometry. An anaerobic curved bacterium was isolated from the rumen microflora. This bacterium was characterized and identified as Wolinella succinogenes according to the method of Holdeman et al. (1977). It could only reduce FA to dihydroferulic acid in the absence of hydrogen acceptors such as nitrate or fumarate and under strictly anaerobic conditions. FA-reducing ability of the bacterium was inhibited to some extent at FA concentrations greater than 5 mM. The FA was reduced more effectively at pH values of 7.0–7.2 than at 6.8 and the reduction was enhanced by the addition of an Ruminococcus albus' culture supernatant.