A Spot Test for Catechol 2:3‐Oxygenase in Bacteria

Abstract

A simple and quickly performed colour test is described, in which organisms containing catechol 2:3‐oxygenase (meta‐pyrocatechase) produce from catechol a yellow coloured intermediate, α‐hydroxymuconic semialdehyde. The yellow colour is produced most consistently, rapidly and intensely by 2–4 day old cultures from 2·7–27 mM solutions of catechol. The purple‐brown colour produced by some organisms is discussed. Using growth from nutrient agar plates, the test was applied to cultures of 239 Gram negative bacteria; all of the 64 cultures which gave a positive result had been in contact previously with aromatic substrates and many of them could oxidize phenol. The significance of a positive reaction is discussed briefly.