Pseudomonas edaphica sp. nov., isolated from rhizospheric soil of Cistus ladanifer L. in Spain.

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).

Bacillus terrae sp. nov. isolated from Cistus ladanifer rhizosphere soil.

A bacterial strain designated RA9T was isolated from a root of Cistus ladanifer in Spain. Phylogenetic analyses based on 16S rRNA gene sequences placed the isolate into the genus Bacillus with its closest relatives being Bacillus fortis R-6514T and Bacillus fordii R-7190T with 98.2 % similarity in both cases. DNA-DNA hybridization studies showed mean relatedness values of 29 and 30 %, respectively, between strain RA9T and the type strains of B. fortis and B. fordii. Cells of the isolate were Gram-stain-positive, motile, sporulating rods. Catalase and oxidase were positive. Gelatin, starch and casein were not hydrolysed. Menaquinone MK-7 was the only menaquinone detected and iso-C15 : 0 and anteiso-C15 : 0 were the major fatty acids. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminophospholipid, one unidentified phospholipid, one unidentifed glycolipid and one unidentified lipid. meso-Diaminopimelic acid was detected in the peptidoglycan. The DNA G+C content was 43.1 mol%. Phylogenetic, chemotaxonomic and phenotypic analyses showed that strain RA9T should be considered as representing a novel species of the genus Bacillus, for which the name Bacillus terrae sp. nov. is proposed. The type strain is RA9T (=LMG 29736T=CECT 9170T).