Pseudomonas gessardii sp nov and Pseudomonas migulae sp nov., two new species isolated from natural mineral waters

Twenty-five non-identified fluorescent Pseudomonas strains isolated from na tural mineral waters were previously clustered into three phenotypic subclu sters, XIIIb, XVa and XVc. These strains were characterized genotypically i n the present study. DNA-DNA hybridization results and DNA base composition analysis revealed that these strains were members of two new species, for which the names Pseudomonas gessardii sp, nov. (type strain CIP 105469(T)) and Pseudomonas migulae sp. nov. (type strain CIP 105470(T)) are proposed. P. gessardii included 13 strains from phenotypic subclusters XVa and XVc. P . migulae included 10 strains from phenotypic subcluster XIIIb. The levels of DNA-DNA relatedness ranged from 71 to 100% for P. gessardii and from 74 to 100% for P. migulae. The G+C content of the DNA of each type strain was 58 mol%. DNA similarity levels, measured with 67 reference strains of Pseud omonas species, were below 55%, with Delta T-m values of 13 degrees C or mo re. The two new species presented basic morphological characteristics commo n to all pseudomonads. Various phenotypic features were found to differenti ate them: P. gessardii strains utilized L-arabitol, myo-inositol, adonitol, xylitol and meso-erythritol as carbon sources, whereas P. migulae strains assimilated L-arabinose, D-xylose, D-saccharate, meso-tartrate, tricarbally late, D-glucuronate, D-galacturonate, phenylacetate and histamine. The comp lete 16S rRNA sequences of each type strain were determined and compared wi th those of the type strains of Pseudomonas species. Finally, a phylogeneti c tree was inferred from sequence analysis and demonstrated that the two ne w species fell into the 'Pseudomonas fluorescens intrageneric cluster'. To date, their clinical significance is unknown.