Catabolism of 4-hydroxybenzoate in Candida parapsilosis proceeds through initial oxidative decarboxylation by a FAD-dependent 4-hydroxybenzoate 1-hydroxylase

FEMS Microbiol Lett. 1994 Aug 15;121(2):207-15. doi: 10.1111/j.1574-6968.1994.tb07100.x.


The first two steps in the catabolism of 4-hydroxybenzoate by the ascomycetous yeast Candida parapsilosis CBS604 were investigated. In contrast to the well-known bacterial pathways and to what was previously assumed, metabolism of 4-hydroxybenzoate in C. parapsilosis proceeds through initial oxidative decarboxylation to give 1,4-dihydroxybenzene. This reaction is catalyzed by a NAD(P)H and FAD-dependent 4-hydroxybenzoate 1-hydroxylase. Further metabolism of 1,4-dihydroxybenzene to the ring-fission substrate 1,2,4-trihydroxybenzene is catalyzed by a NADPH-specific FAD-dependent aromatic hydroxylase acting on phenolic compounds. 19F-NMR experiments with cell extracts and 2-fluoro-4-hydroxybenzoate as the model compound confirm this metabolic pathway and exclude the alternative pathway proceeding through initial 3-hydroxylation followed by oxidative decarboxylation in the second step.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 4-Hydroxybenzoate-3-Monooxygenase / metabolism*
  • Candida / enzymology*
  • Candida / metabolism
  • Decarboxylation
  • Flavin-Adenine Dinucleotide / metabolism*
  • Parabens / metabolism*


  • Parabens
  • Flavin-Adenine Dinucleotide
  • 4-Hydroxybenzoate-3-Monooxygenase
  • 4-hydroxybenzoic acid