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Pseudomonas guariconensis sp. nov., isolated from rhizospheric soil

2013; Microbiology Society; Volume: 63; Issue: Pt_12 Linguagem: Inglês

10.1099/ijs.0.051193-0

1466-5034

Marcia Toro, Martha-Helena Ramírez-Bahena, Marı́a José Domı́nguez Cuesta, Encarna Velázquez, Álvaro Péix,

Genomics and Phylogenetic Studies

We isolated a bacterial strain designated PCAVU11 T in the course of a study of phosphate-solubilizing bacteria occurring in rhizospheric soil of Vigna unguiculata (L.) Walp. in Guárico state, Venezuela. The 16S rRNA gene sequence had 99.2 % sequence similarity with respect to the most closely related species, Pseudomonas taiwanensis , and 99.1 % with respect to Pseudomonas entomophila , Pseudomonas plecoglossicida and Pseudomonas monteilii , on the basis of which PCAVU11 T was classified as representing a member of the genus Pseudomonas . Analysis of the housekeeping genes rpoB , rpoD and gyrB confirmed the phylogenetic affiliation and showed sequence similarities lower than 95 % in all cases with respect to the above-mentioned closest relatives. Strain PCAVU11 T showed two polar flagella. The respiratory quinone was Q9. The major fatty acids were 16 : 0 (25.7 %), 18 : 1ω7 c (20.4 %), 17 : 0 cyclo (11.5 %) and 16 : 1ω7 c /15 : 0 iso 2-OH in summed feature 3 (10.8 %). The strain was oxidase-, catalase- and urease-positive, the arginine dihydrolase system was present but nitrate reduction, β-galactosidase production and aesculin hydrolysis were negative. Strain PCAVU11 T grew at 44 °C and at pH 10. The DNA G+C content was 61.5 mol%. DNA–DNA hybridization results showed values lower than 56 % relatedness with respect to the type strains of the four most closely related species. Therefore, the results of genotypic, phenotypic and chemotaxonomic analyses support the classification of strain PCAVU11 T as representing a novel species of the genus Pseudomonas , which we propose to name Pseudomonas guariconensis sp. nov. The type strain is PCAVU11 T ( = LMG 27394 T = CECT 8262 T ).