Which gram-negative rod is known to not ferment carbohydrates and produces a green pigment?

Pseudomonas aeruginosa is recognized for its distinctive characteristics, which include the inability to ferment carbohydrates and the production of a characteristic green pigment. This organism is known for its metabolic versatility; it primarily utilizes oxidative respiration rather than fermentation for energy. When grown on certain media, particularly those supplemented with nutrients, Pseudomonas aeruginosa can produce a green pigment, often related to the compound pyocyanin, which is a key identifying feature of this bacterium.

In clinical settings, the role of Pseudomonas aeruginosa is significant, as it is an opportunistic pathogen commonly associated with infections in immunocompromised individuals and is known for its resistance to many antibiotics. The ability to produce this pigment is not only useful for identification in laboratory diagnostics but also is involved in its pathogenicity.

Other gram-negative rods listed, like Klebsiella pneumoniae, Serratia species, and Enterobacter species, are typically known for their carbohydrate fermentation capabilities. They produce different metabolic byproducts when fermenting carbohydrates and do not usually produce a green pigment characteristic of Pseudomonas aeruginosa. Thus, identifying Pseudomonas aeruginosa based on its non-fermentative nature and pigment production is crucial for microbiological