Chryseobacterium hispalense sp. nov., a plant-growth-promoting bacterium isolated from a rainwater pond in an olive plant nursery, and emended descriptions of Chryseobacterium defluvii, Chryseobacterium indologenes, Chryseobacterium wanjuense and Chryseobacterium gregarium

Abstract

A novel non-motile, Gram-staining-negative, yellow-pigmented bacterium, designated AG13(T), isolated from a rain water pond at a plant nursery in Spain and characterized as a plant-growth-promoting bacterium, was investigated to determine its taxonomic status. The isolate grew best over a temperature range of 15-40 °C, at pH 5.0-8.0 and with 0-4 % (w/v) NaCl. Chemotaxonomic and molecular characteristics of the isolate matched those described for members of the genus Chryseobacterium. The DNA G+C content of the novel strain was 37.2 mol%. The strain had a polyamine pattern with sym-homospermidine as the major compound and produced flexirubin-type pigments. MK-6 was the dominant menaquinone and the major cellular fatty acids were iso-C15 : 0, C17 : 1ω9c and iso-C17 : 0 3-OH. The main polar lipids were phosphatidylethanolamine, aminolipids and several unidentified lipids. The 16S rRNA gene showed 92.0-97.2 % sequence similarity with those of the members of the genus Chryseobacterium. Based on chemotaxonomic and phenotypic traits, and DNA-DNA hybridizations with the type strains of the most closely related species, the isolate is proposed to represent a novel species, Chryseobacterium hispalense, type strain AG13(T) ( = DSM 25574(T) = CCUG 63019(T)). Emended descriptions of the species Chryseobacterium defluvii, Chryseobacterium indologenes, Chryseobacterium wanjuense and Chryseobacterium gregarium are also provided.