Discussion
A comparison of the effects of four phenolic compounds
commonly found in lignocellulosic hydrolysates showed
that coniferyl aldehyde was most toxic for G. xylinus.
The main bioconversion product of coniferyl aldehyde
was ferulic acid, which is formed by oxidation of the
aldehyde group to a carboxylic acid group. As ferulic acid
was found to be less toxic than coniferyl aldehyde, this
biotransformation will serve as a detoxification reaction.
In a study with the bacterium Pseudomonas sp strain HR
199, coniferyl aldehyde dehydrogenase was found to be
responsible for intracellular conversion of coniferyl aldehyde
to ferulic acid [25]. The bacterium Acetobacter aceti
MIM2000/28 has also been reported to have the ability
to oxidize aldehydes into corresponding carboxylic