초록
<P>Ferulic acid (4-hydroxy-3-methoxycinnamic acid, FA) is a lignin-derived phenolic compound abundant in plant biomass. The utilization of FA and its conversion to valuable compounds is desired. Protocatechuic acid (3,4-dihydroxybenzoic acid, PCA) is a precursor of polymers and plastics and a constituent of food. A microbial conversion system to produce PCA from FA was developed in this study using a PCA-producing strain of <I>Corynebacterium glutamicum</I> F (ATCC 21420). <I>C. glutamicum</I> strain F grown at 30 °C for 48 h utilized 2 mM each of FA and vanillic acid (4-hydroxy-3-methoxybenzoic acid, VA) to produce PCA, which was secreted into the medium. FA may be catabolized by <I>C. glutamicum</I> through proposed (I) non-β-oxidative, CoA-dependent or (II) β-oxidative, CoA-dependent phenylpropanoid pathways. The conversion of VA to PCA is the last step in each pathway. Therefore, the vanillate <I>O</I>-demethylase gene (<I>van</I>AB) from <I>Corynebacterium efficiens</I> NBRC 100395 was expressed in <I>C. glutamicum</I> F (designated strain FVan) cultured at 30 °C in AF medium containing FA. Strain <I>C. glutamicum</I> FVan converted 4.57 ± 0.07 mM of FA into 2.87 ± 0.01 mM PCA after 48 h with yields of 62.8% (mol/mol), and 6.91 mM (1064 mg/L) of PCA was produced from 16.0 mM of FA after 12 h of fed-batch biotransformation. Genomic analysis of <I>C. glutamicum</I> ATCC 21420 revealed that the PCA-utilization genes (<I>pca</I> cluster) were conserved in strain ATCC 21420 and that mutations were present in the PCA importer gene <I>pca</I>K.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1186/s13568-017-0427-9) contains supplementary material, which is available to authorized users.</P>