During a study on biodiversity of bacteria inhabiting rhizospheric soil of rockrose (Cistus ladanifer L.), we isolated a strain coded RD25T in a soil from Northern Spain. The 16S rRNA gene sequence showed 99.5 % identity with respect to the closest related species Pseudomonas brenneri DSM15294T, and 99.4 % with respect to P. paralactis WS4672T. The following related Pseudomonas species showed 99.3 % or less identity, and therefore RD25T was classified within genus Pseudomonas. The phylogenetic analysis of 16S rRNA and the housekeeping genes rpoB, rpoD and gyrB suggested that this strain could be a novel species. The strain RD25T has several polar-subpolar flagella. It can grow at 36 °C, at 0-6 % NaCl concentration and a range of pH 5-9. Positive for arginine dihydrolase and urease production, and negative for reduction of nitrate. The strain is catalase and oxidase positive. Major fatty acids are C16 : 1 ω7c / C16 : 1 ω6c in summed feature 3, C16 : 0, and C18 : 1 ω7c / C18 : 1 ω6c in summed feature 8. The respiratory ubiquinone is Q9. The DNA G+C content was 59.9 mol%. The digital DNA-DNA hybridisation average values (dDDH) ranged between 30-61.2 % relatedness and the ANIb values ranged between 93.9-80.5 % with respect to the type strains of the closely related species. Therefore, the genotypic, genomic, phenotypic and chemotaxonomic data support the classification of strain RD25 as a novel species of genus Pseudomonas, for which the name P. edaphica sp. nov. is proposed. The type strain is RD25T (=LMG 30152T=CECT 9373T).
Keywords: Cistus ladanifer L. PGPR; Pseudomonas; rhizospheric soil; taxonomy.