Pseudomonas spirodelae, sp. nov., a bacterium isolated from the roots of the aquatic plant Spirodela polyrhiza

A polyphasic taxonomic study was carried out on strain T5W1^T, isolated from the roots of the aquatic plant <i>Spirodela polyrhiza</i>. This isolate is Gram-negative, rod-shaped, motile, aerobic and non-pigmented. Nearly complete 16S rRNA gene sequence homology related the strain to <i>Pseudomonas</i>, with 98.4% similarity to <i>P. guineae</i>, <i>P. peli</i> and <i>P. leptonychotis</i>. Average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) with the closest phylogenetic neighbour of T5W1^T showed differences at the species level, further confirmed by differences in several physiological characteristics. The main fatty acids are summed feature 3 (C_{16 : 1} <i> </i> _ω7c and/or C_{16 : 1} <i> </i> _ω6c), C_{18 : 1} <i> </i> _ω7c, and C_{16 : 0}. The DNA G+C content is 59.3 mol%. Q-9 is the primary ubiquinone found, and phosphatidylethanolamine is the dominant polar lipid, with lesser amounts of phosphatidylglycerol, diphosphatidylglycerol and phosphatidylserine. Based on the results obtained, this bacterium is assigned to the genus <i>Pseudomonas</i> as a new species with the name <i>Pseudomonas spirodelae</i> sp. nov., type strain T5W1^T (=NRRL B-65714^T =DSM 118085^T).