Chen H.,Ludwig Maximilians University of Munich |
Chen H.,Leibniz Institute DSMZ Deutsche Sammlung von Mikroorganismen und Zellkulturen Braunschweig GmbH |
Jogler M.,Ludwig Maximilians University of Munich |
Jogler M.,Leibniz Institute DSMZ Deutsche Sammlung von Mikroorganismen und Zellkulturen Braunschweig GmbH |
And 7 more authors.
International Journal of Systematic and Evolutionary Microbiology | Year: 2012
'Caulobacter leidyi' DSM 4733T has been shown to be affiliated with the family Sphingomonadaceae instead of the Caulobacteraceae, and due to its poor characterization has been omitted from the current edition of Bergey's Manual of Systematic Bacteriology and removed to limbo. We isolated a novel sphingoglycolipid-containing dimorphic prosthecate bacterium, designated strain 247, from a pre-alpine freshwater lake. Strain 247 and 'Caulobacter leidyi' DSM 4733T were characterized in detail. The rod-shaped cells were Gram-stain-negative, aerobic, catalase- and oxidase-positive, and formed a stalk or polar flagellum. Both strains grew optimally at 28-30 °C, and pH 6.0-8.0. The major fatty acids were C18: 1ω7c, C16: 0 and 11-methyl C18: 1ω7c. C14: 0 2-OH represents the major 2-hydroxy fatty acid. Q-10 was the major respiratory quinone and the major polar lipids were diphosphatidylglycerol, phosphatidyldimethylethanolamine, phosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, phosphatidylcholine, three glycolipids, two phosphoaminolipids and two unidentified sphingoglycolipids. The major polyamine was sym-homospermidine. The G+C content of genomic DNA of strains 247 and DSM 4733T was 67.6 mol% and 67.0 mol%, respectively. According to 16S rRNA gene sequence analysis and DNA-DNA hybridization, strains DSM 4733T and 247 were phylogenetically closely related (99.6 % 16S rRNA gene sequence similarity, 82.9 % DNA-DNA hybridization value) and affiliated to the genus Sphingomonas. The closest recognized species was Sphingomonas aquatilis DSM 15581T (98.1 % sequence similarity). In addition, the presence of cystine arylamidase, absence of β-galactosidase, and the inability to utilize l-arabinose, galactose and sucrose distinguished strains DSM 4733T and 247 from most other members of the family Sphingomonadaceae. So far, the dimorphic life cycle that involves a prosthecate and a flagellated stage is unique for strains DSM 4733T and 247 among all members of the family Sphingomonadaceae. Therefore, Caulobacter leidyi is reclassified as Sphingomonas leidyi, with the type strain DSM 4733T (= ATCC 15260T = CIP 106443T = VKM B-1368T) and strain 247 (DSM 25078 = LMG 26658) as an additional strain of this species. © 2012 IUMS.