Sphingomonas cynarae sp. nov., a proteobacterium that produces an unusual type of sphingan.
Strain SPC-1(T) was isolated from the phyllosphere of Cynara cardunculus L. var. sylvestris (Lamk) Fiori (wild cardoon), a Mediterranean native plant considered to be the wild ancestor of the globe artichoke and cultivated cardoon. This Gram-stain-negative, catalase-positive, oxidase-negative, non-spore-forming, rod-shaped and non-motile strain secreted copious amounts of an exopolysaccharide, 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-1(T) clustered together with species of the genus Sphingomonas sensu stricto. 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, 2-hydroxymyristic acid (C(14 : 0) 2-OH) as the major hydroxylated fatty acid, the absence of 3-hydroxy fatty acids and the presence of sphingoglycolipid supported this taxonomic position. 16S rRNA gene sequence analysis showed that SPC-1(T) was most closely related to Sphingomonas hankookensis ODN7(T), Sphingomonas insulae DS-28(T) and Sphingomonas panni C52(T) (98.19, 97.91 and 97.11 % sequence similarities, 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-1(T) represents a novel species of the genus Sphingomonas, for which the name Sphingomonas cynarae sp. nov. is proposed; the type strain is SPC-1(T) ( = JCM 17498(T) = ITEM 13494(T)). A component analysis of the exopolysaccharide 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.
Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, Via Monteroni, 73100 Lecce, Italy.
Adelfia
A
Talà
Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, Via Monteroni, 73100 Lecce, Italy.
Marcello
M
Lenucci
CNR - Institute of Biomembranes and Bioenergetics (IBBE), Via G. Amendola, 165/A, 70126 Bari, Italy.
Antonio
A
Gaballo
CNR - Institute of Sciences of Food Production (ISPA), Operative Unit of Lecce, via Provinciale Lecce-Monteroni, 73100 Lecce, Italy.
Miriana
M
Durante
Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, Via Monteroni, 73100 Lecce, Italy.
Salvatore M
SM
Tredici
Department of Botany and Plant Pathology, Purdue University, 915 West State Street, West Lafayette, IN 47907-2054, USA.
Danisha A
DA
Debowles
Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, Via Monteroni, 73100 Lecce, Italy.
Graziano
G
Pizzolante
Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, Via Monteroni, 73100 Lecce, Italy.
Carlo
C
Marcuccio
Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, Via Monteroni, 73100 Lecce, Italy.
Elisabetta
E
Carata
Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, Via Monteroni, 73100 Lecce, Italy.
Gabriella
G
Piro
Department of Botany and Plant Pathology, Purdue University, 915 West State Street, West Lafayette, IN 47907-2054, USA.
Nicholas C
NC
Carpita
CNR - Institute of Sciences of Food Production (ISPA), Operative Unit of Lecce, via Provinciale Lecce-Monteroni, 73100 Lecce, Italy.
Giovanni
G
Mita
Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, Via Monteroni, 73100 Lecce, Italy.
Pietro
P
Alifano
D015373:Bacterial Typing Techniques; D001482:Base Composition; D031942:Cynara / Q000382:microbiology*; D004269:DNA, Bacterial / Q000235:genetics; D005227:Fatty Acids / Q000032:analysis; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010802:Phylogeny; D011073:Polyamines / Q000032:analysis; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D020578:Sphingomonas / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D014451:Ubiquinone / Q000032:analysis
D004269:DNA, Bacterial; D005227:Fatty Acids; D011073:Polyamines; D011135:Polysaccharides, Bacterial; D012336:RNA, Ribosomal, 16S; C430406:sphingan; D014451:Ubiquinone