Pseudomonas flavocrustae sp. nov., an endophyte with plant growth promoting traits isolated from Passiflora incarnata

Abstract

A polyphasic approach was applied to characterize taxonomically a novel endophytic bacterial strain, designated as EP178T, which was previously isolated from Passiflora incarnata leaves and characterized as plant-growth promoter. The strain EP178T forms Gram stain-negative and rod-shaped cells, and circular and yellow-pigmented colonies. Its growth occurs at 10–37 °C, at pH 6.0–8.0, and tolerates up to 7% (w/v) NaCl. The major cellular fatty acids found were summed feature 8 (C18:1 ω7c), summed feature 3 (C16:1 ω6c /C16:1 ω7c), and C16:0, and the predominant ubiquinone was Q-9. The phylogenetic and nucleotide-similarity analysis with 16S rRNA gene sequences showed that strain EP178T belongs to Pseudomonas genus. The genomic-based G + C content was 65.5%. The average nucleotide identity and digital DNA-DNA hybridization values between strains EP178T and the closest type strain, P. oryzihabitans DSM 6835T, were 92.6% and 52.2%, respectively. Various genes associated with plant-growth promoting mechanisms were annotated from genome sequences. Based on the phenotypic, genomic, phylogeny and chemotaxonomic data, strain EP178T represents a new species of the genus Pseudomonas, for which the name Pseudomonas flavocrustae sp. nov. was proposed. The type strain is EP178T (= CBMAI 2609T = ICMP 24844T = MUM 23.01T).