This paper describes the establishment of a new bacterial genus, Deleya, created to reclassify five marine species previously assigned to Alcaligenes and Pseudomonas. The authors, based on ribosomal RNA homology studies and other evolutionary analyses, demonstrated that four marine Alcaligenes species (A. aestus, A. pacificus, A. cupidus, A. venustus) and Pseudomonas marina form a distinct evolutionary lineage separate from their previously assigned genera. The new genus Deleya contains gram-negative, aerobic rods that accumulate poly-β-hydroxybutyrate, require sodium for growth, and are found in marine environments. Most species are motile via peritrichous flagella, except D. marina, which has polar flagella. The five species differ in flagellation patterns, substrate utilization profiles, DNA G+C content (52-68 mol%), and growth characteristics. All species utilize glucose, acetate, and several other compounds through the Entner-Doudoroff pathway. The authors provide detailed phenotypic characterizations and distinguish Deleya species from phenotypically similar genera like Pseudomonas and Alteromonas based on flagellation type, substrate utilization patterns, and sodium requirements.

Key findings

• Five marine bacterial species previously classified as Alcaligenes or Pseudomonas were reclassified into a new genus Deleya based on ribosomal RNA homology analysis revealing a distinct evolutionary lineage.
• Deleya species are gram-negative, aerobic marine bacteria requiring sodium (75-200 mM) for optimal growth, accumulating poly-β-hydroxybutyrate, with DNA G+C content ranging from 52-68 mol%.
• Most Deleya species possess peritrichous flagella, while D. marina uniquely has 2-5 polar flagella, and they can utilize 35-85 different organic compounds including sugars, fatty acids, and aromatic compounds.
• Deleya species metabolize glucose and fructose via the Entner-Doudorff pathway and can be distinguished from related marine genera by their unique combination of substrate utilization patterns and lack of extracellular enzymes like gelatinase and lipase.