초록
<P><B>Abstract</B></P><P><B>Aim</B></P><P>To isolate a bacterial strain capable of biotransforming ferulic acid, a major component of lignin, into vanillin and vanillic acid by a rapid colorimetric screening method.</P><P><B>Methods and Results</B></P><P>For the production of vanillin, a natural aroma compound, we attempted to isolate a potential strain using a simple screening method based on pH change resulting from the degradation of ferulic acid. The strain <I>Pseudomonas</I> sp. AZ<SUB>10</SUB> UPM exhibited a significant result because of colour changes observed on the assay plate on day 1 with a high intensity of yellow colour. The biotransformation of ferulic acid into vanillic acid by the AZ10 strain provided the yield (<I>Y</I><SUB><I>p</I>/<I>s</I></SUB>) and productivity (<I>P</I><SUB>r</SUB>) of 1·08？mg？mg<SUP>−1</SUP> and 53·1？mg？L<SUP>−1</SUP>？h<SUP>−1</SUP>, respectively. In fact, new investigations regarding lignin degradation revealed that the strain was not able to produce vanillin and vanillic acid directly from lignin; however, partially digested lignin by mixed enzymatic treatment allowed the strain to produce 30·7？mg？l<SUP>−1</SUP> and 1·94？mg？l<SUP>−1</SUP> of vanillic acid and biovanillin, respectively.</P><P><B>Conclusions</B></P><P>(i) The rapid colorimetric screening method allowed the isolation of a biovanillin producer using ferulic acid as the sole carbon source. (ii) Enzymatic treatment partially digested lignin, which could then be utilized by the strain to produce biovanillin and vanillic acid.</P><P><B>Significance and Impact of the Study</B></P><P>To the best of our knowledge, this is the first study reporting the use of a rapid colorimetric screening method for bacterial strains producing vanillin and vanillic acid from ferulic acid.</P>