Influence of para-substituents on the oxidative metabolism of o-nitrophenols by Pseudomonas putida B2

Appl Environ Microbiol. 1986 Aug;52(2):334-9. doi: 10.1128/aem.52.2.334-339.1986.


Pseudomonas putida B2 is able to grow on o-nitrophenol (ONP) as the sole source of carbon and nitrogen. ONP was converted by a nitrophenol oxygenase to nitrite and catechol. Catechol was then attacked by a catechol 1,2-dioxygenase and further degraded through an ortho-cleavage pathway. ONP derivatives which were para-substituted with a methyl-, chloro-, carboxy-, formyl- or nitro-group failed to support growth of strain B2. Relevant catabolic enzymes were characterized to analyze why these derivatives were not mineralized. Nitrophenol oxygenase of strain B2 is a soluble, NADPH-dependent enzyme that is stimulated by magnesium, manganese, and calcium ions. It is active toward ONP, 4-methyl-, 4-chloro-, and to a lesser extent, 4-formyl-ONP but not toward 4-carboxy- or 4-nitro-ONP. In addition, 4-formyl-, 4-carboxy-, and 4-nitro-ONP failed to induce the formation of nitrophenol oxygenase. Catechol 1,2-dioxygenase of strain B2 is active toward catechol and 4-methyl-catechol but only poorly active toward chlorinated catechols. 4-Methyl-catechol is likely to be degraded to methyl-lactones, which are often dead-end metabolites in bacteria. Thus, of the compounds tested, only unsubstituted ONP acts as an inducer and substrate for all of the enzymes of a productive catabolic pathway.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catechol 1,2-Dioxygenase
  • Dioxygenases*
  • Kinetics
  • Mixed Function Oxygenases / metabolism*
  • Nitrophenols / metabolism*
  • Nitrophenols / pharmacology
  • Oxidation-Reduction
  • Oxygenases / metabolism*
  • Pseudomonas / drug effects
  • Pseudomonas / growth & development
  • Pseudomonas / metabolism*
  • Structure-Activity Relationship


  • Nitrophenols
  • Mixed Function Oxygenases
  • Oxygenases
  • Dioxygenases
  • Catechol 1,2-Dioxygenase
  • 2-nitrophenol oxygenase