Description of Pseudomonas gorinensis sp. nov., a plant growth-promoting bacterium that modulates stomatal aperture

GONZALEZ, MARÍA ELISA; CASTAGNO, LUIS NAZARENO; SANNAZZARO, ANALÍA INÉS; RIOS, CAMILA; GUDESBLAT, GUSTAVO EDUARDO; ALTABE, SILVIA GRACIELA; BEDOYA-CASTAÑEDA, DIANA CAROLINA; ESTRELLA, MARÍA JULIA; PIECKENSTAIN, FERNANDO LUIS

INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY.

SOC GENERAL MICROBIOLOGY

Año: 2025 vol. 75

1466-5026

A polyphasic taxonomic approach was used to characterize a previously isolated plant growth-promoting Pseudomonasstrain designated as NT2T and a Pseudomonas strain designated as TKP (JCM 19688), both of which were found to manipulate plant stomatal immunity. Both strains shared 100% 16S rRNA gene sequence identity. Phylogenetic trees based on single and concatenated sequences of the housekeeping genes gyrB, rpoB, rpoD and 16S rRNA, as well as whole-genome sequences, clustered NT2T and TKP together, clearly separated from the closest Pseudomonas spp., which belonged to the Pseudomonas fluorescens complex. NT2T showed average nucleotide identities (ANIs) of 87.8% (ANIb) and 89.9% (ANIm) and a 37.4% digital DNA–DNA hybridization score with Pseudomonas grimontii DSM 17515T, the species with the highest genome sequence similarity. On the contrary, the comparison between NT2T and TKP showed very high ANI (ANIb=99.67, ANIm=99.93) and digital DNA–DNA hybridization scores (98.90%). NT2T and TKP differed from closely related species in relation to arginine dihydrolase activity, aesculin and gelatin hydrolysis, N-acetyl-d-glucosamine, maltose, adipate, phenylacetate, p-hydroxy-phenylacetic acid, Tween 40, glycyl-l-proline, d-maltose, d-galactonic acid lactone, α-hydroxy butyric acid, myo-inositol, sucrose, l-histidine, d-malic acid, l-rhamnose and acetic acid assimilation, NaCl-tolerance range and pyocyanin production (fluorescence on King A medium). The major fatty acids in NT2T and TKP were C16:0, C16:1ω7t and C18:1ω7c. The results of this polyphasic study allowed the genotypic and phenotypic differentiation of NT2T and TKP from the closest Pseudomonas and confirmed that these strains represent a novel species, for which the name Pseudomonas gorinensis sp. nov. is proposed with NT2T (DSM 114757T=LMG 32751T) as the type strain.