Details for Pseudomonas

All organisms in this group are straight or slightly curved chemoorganotrophic and aerobic rods with polar flagella. Key identifying characteristics are the absence of gas formation from glucose, and the positive oxidase test, both of which help to distinguish pseudomonads from enteric bacteria.

The species of the genus Pseudomonas are defined on the basis of phylogeny and various physiological characteristics. Pseudomonads have very simple nutritional requirements and grow chemoorganotrophically at neutral pH and at temperatures in the mesophilic range. One of the striking properties of many species of pseudomonads is the wider variety of organic compounds used as carbon and energy sources. Some species utilize over 100 different compounds, and only a few species utilize fewer than 20. On the other hand, pseudomonads generally lack the hydrolytic enzymes necessary to break down polymers into their component monomers. Nutritionally versatile pseudomonads typically contain numerous inducible operons because the catabolism of unusual organic substrates often requires the activity of several different enzymes. The pseudomonads are ecologically important organisms in soil and water and are probably responsible for the degradation of many soluble compounds derived from the breakdown of plant and animal materials in oxic habitats.

Many pseudomonads, as well as a variety of other gram-negative Bacteria, metabolize glucose via the Entner-Doudoroff pathway. Two key enzymes of the Entner-Doudoroff pathway are 6-phosphogluconate dehydrase and 2-keto-3-deoxyglucosephosphate aldolase.

For more characteristics of pseudomonads click here.