Abstract: Strain SPC-1T was isolated from the phyllosphere of Cynara cardunculus L. var. sylvestris (Lamk) Fiori (wild cardoon), a Mediterranean native plant considered the wild ancestor of the globe artichoke and cultivated cardoon. This Gram-negative, catalase-positive, oxidase-negative, non-spore-forming, rod-shaped and non-motile strain secreted copious amounts of an exopolysaccharide and formed slimy, viscous, orange-pigmented colonies and grew optimally at around pH 6.0-6.5 and 26-30°C in the presence of 0-0.5% NaCl. Phylogenetic analysis based on comparisons of 16S rRNA gene sequences demonstrated that SPC-1T clustered together with species of the genus Sphingomonas sensu strictu. The G+C content of the DNA (66.1 mol%), the presence of Q-10 as the predominant ubiquinone, sym-homospermidine as the predominant polyamine, and 2-hydroxymiristic acid (C14:0 2-OH) as the major hydroxylated fatty acid, the absence of 3-hydroxy fatty acids and the presence of sphingoglycolipid supported this taxonomical position. 16S rRNA gene sequence analysis showed that SPC-1 was most closely related to Sphingomonas hankookensis ODN7T, Sphingomonas insulae DS-28T and Sphingomonas panni C52T (98.19%, 97.91% and 97.11% similarity, respectively). However, DNA-DNA hybridization analysis did not reveal any relatedness at the species level. Further differences were apparent in biochemical traits, and fatty acid, quinone and polyamine profiles leading us to conclude that strain SPC-1T (JCM 17498; ITEM 13494) represents a new species of Sphingomonas, for which the name Sphingomonas cynarae sp. nov. is proposed. A component analysis of the exopolysaccharide (named SPC-1T EPS) suggested that it represents a novel type of sphingan containing glucose, rhamnose, mannose and galactose, while glucuronic acid, which is commonly found in sphingans, was not detected.
Sphingomonas cynarae sp. nov., a proteobacterium that produces an unusual type of sphingan
TALA', ADELFIA;LENUCCI, Marcello Salvatore;CARATA, ELISABETTA;PIRO, Gabriella;ALIFANO, Pietro
2013-01-01
Abstract
Abstract: Strain SPC-1T was isolated from the phyllosphere of Cynara cardunculus L. var. sylvestris (Lamk) Fiori (wild cardoon), a Mediterranean native plant considered the wild ancestor of the globe artichoke and cultivated cardoon. This Gram-negative, catalase-positive, oxidase-negative, non-spore-forming, rod-shaped and non-motile strain secreted copious amounts of an exopolysaccharide and formed slimy, viscous, orange-pigmented colonies and grew optimally at around pH 6.0-6.5 and 26-30°C in the presence of 0-0.5% NaCl. Phylogenetic analysis based on comparisons of 16S rRNA gene sequences demonstrated that SPC-1T clustered together with species of the genus Sphingomonas sensu strictu. The G+C content of the DNA (66.1 mol%), the presence of Q-10 as the predominant ubiquinone, sym-homospermidine as the predominant polyamine, and 2-hydroxymiristic acid (C14:0 2-OH) as the major hydroxylated fatty acid, the absence of 3-hydroxy fatty acids and the presence of sphingoglycolipid supported this taxonomical position. 16S rRNA gene sequence analysis showed that SPC-1 was most closely related to Sphingomonas hankookensis ODN7T, Sphingomonas insulae DS-28T and Sphingomonas panni C52T (98.19%, 97.91% and 97.11% similarity, respectively). However, DNA-DNA hybridization analysis did not reveal any relatedness at the species level. Further differences were apparent in biochemical traits, and fatty acid, quinone and polyamine profiles leading us to conclude that strain SPC-1T (JCM 17498; ITEM 13494) represents a new species of Sphingomonas, for which the name Sphingomonas cynarae sp. nov. is proposed. A component analysis of the exopolysaccharide (named SPC-1T EPS) suggested that it represents a novel type of sphingan containing glucose, rhamnose, mannose and galactose, while glucuronic acid, which is commonly found in sphingans, was not detected.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
