Pseudomonas yongnianensis sp. nov., Isolated from the Rhizosphere Soil of Wheat in a High-Yield Farmland

A novel Pseudomonas strain, designated S9268T, was isolated from the rhizosphere soil of wheat in Yongnian District, Handan City, Hebei Province, PR China. Cells were Gram-stain-negative, aerobic, rod-shaped, and motile by means of multiple polar flagella. Phylogenetic analyses based on 16S rRNA gene and multilocus sequence analysis (MLSA) of four housekeeping genes (16S rRNA gene, gyrB, rpoB, and rpoD) placed strain S9268T within the genus Pseudomonas but as a distinct lineage separated from its closest relatives, Pseudomonas asturiensis LMG 26898T, Pseudomonas avellanae LMG 21662T, and Pseudomonas lijiangensis JCM 35177T. The average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values between strain S9268T and three reference strains ranged from 83.1% to 83.5% and from 24.9% to 25.6%, respectively, which were below the recommended thresholds for prokaryotic species delineation. The strain can grow at 4–37 °C (optimum, 28 °C), at pH 6.0–9.0 (optimum, pH 7.0), and with 1–4% (w/v) NaCl (optimum, 1%). The major cellular fatty acids (>10% of the total) were C16:0, summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), summed feature 8 (C18:1 ω7c and/or C18:1 ω6c), and C17:0 cyclo. The polar lipid profile consisted of phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, three unidentified aminophospholipids, an unidentified phosphoglycolipid, and an unidentified polar lipid. The predominant respiratory quinone was ubiquinone Q-9. The draft genome of strain S9268T was 5,250,102 bp in length with a DNA G+C content of 61.2 mol%. Genome analysis revealed T3SS-related genes and a terpene biosynthetic gene cluster showing similarity to carotenoid biosynthetic clusters. Based on the polyphasic taxonomic evidence, strain S9268T represents a novel species within the genus Pseudomonas, for which the name Pseudomonas yongnianensis sp. nov. is proposed. The type strain is S9268T (=ACCC 64339T = JCM 38183T).