False-negative oxidase reaction as a result of medium acidification.
Acidification of the culture medium may lead to a false-negative result of the oxidase reaction. Hence, if the medium contained a carbon source or another component that is convertible to acid, a negative oxidase reaction should be considered inconclusive. In order to eliminate false-negative reactions, a reagent freshly adjusted to pH 5-7 might be used; this reagent should be checked on known oxidase-negative strains. However, we recommend that the oxidase test be performed with the normal reagent after (sub)culturing on a non-acidogenic medium.
D000333:Aeromonas / Q000201:enzymology*; D000362:Agar; D002241:Carbohydrates / Q000494:pharmacology; D005188:False Negative Reactions; D006863:Hydrogen-Ion Concentration; D010088:Oxidoreductases / Q000378:metabolism*; D011549:Pseudomonas / Q000201:enzymology*; D013045:Species Specificity; D014733:Vibrio / Q000201:enzymology*
D002241:Carbohydrates; D000362:Agar; D010088:Oxidoreductases