Phthalate metabolism in Pseudomonas testosteroni: accumulation of 4,5-dihydroxyphthalate by a mutant strain

J Bacteriol. 1977 Jul;131(1):42-8. doi: 10.1128/jb.131.1.42-48.1977.


A mutant strain of Pseudomonas testosteroni blocked in phthalate catabolism converted phthalate into 4,5-dihydroxyphthalate. The latter compound was isolated, and its physical properties were determined. A stoichiometric conversion of the compound to protocatechuate was demonstrated spectrophotometrically with crude extracts of a protocatechuate 4,5-dioxygenase-deficient mutant. Therefore, phthalate is metabolized through 4,5-dihydroxyphthalate and protocatechuate, which is further degraded by protocatechuate 4,5-dioxygenase in P. testosteroni. By using several mutants blocked in phthalate catabolism, 4,5-dihydroxyphthalate decarboxylase was shown to be induced by phthalate. A simple spectrophotometric assay for the enzyme is also reported.

MeSH terms

  • Carboxy-Lyases / biosynthesis
  • Carboxy-Lyases / metabolism
  • Enzyme Induction
  • Mutation
  • Phthalic Acids / metabolism*
  • Protocatechuate-3,4-Dioxygenase / biosynthesis
  • Pseudomonas / enzymology
  • Pseudomonas / metabolism*
  • Spectrophotometry
  • Spectrophotometry, Ultraviolet


  • Phthalic Acids
  • Protocatechuate-3,4-Dioxygenase
  • Carboxy-Lyases