Which tests are most appropriate to differentiate between Pseudomonas aeruginosa and Pseudomonas putida?

The most appropriate tests to differentiate between Pseudomonas aeruginosa and Pseudomonas putida involve assessing their biochemical capabilities, which can highlight significant differences in their metabolic characteristics.

Pseudomonas aeruginosa and Pseudomonas putida can both be oxidase-positive, which means that the oxidase test is not sufficient to differentiate them. However, Pseudomonas aeruginosa is known for its ability to grow at 42°C and can often reduce nitrate, while Pseudomonas putida does not typically possess these abilities to the same extent.

Therefore, utilizing mannitol fermentation, nitrate reduction tests, and growth at elevated temperatures effectively identifies Pseudomonas aeruginosa since this species can utilize these conditions as part of its metabolic profile. This combination of tests offers a reliable differentiation between the two species, making them a compelling choice.

Other tests listed in alternative options may not provide sufficient specificity or relevance for distinguishing these particular species. For instance, the oxidase test appears in multiple options, which lacks the necessary discriminative capability in this context.