Terricaulis silvestris gen. nov., sp. nov., a novel prosthecate, budding member of the family Caulobacteraceae isolated from forest soil

The family Caulobacteraceae comprises prosthecate bacteria with a dimorphic cell cycle and also non-prosthecate bacteria. Cells of all described species divide by binary fission. Strain 0127_4(T) was isolated from forest soil in Baden Wurttemberg (Germany) and determined to be the first representative of the family Caulobacteraceae which divided by budding. Cells of strain 0127_4(T) were Gram-negative, rod-shaped, prosthecate, motile by means of a polar flagellum, non-spore-forming and non-capsulated. The strain formed small white colonies and grew aerobically and chemo-organotrophically utilizing organic acids, amino acids and proteinaceous substrates. 165 rRNA gene sequence analysis indicated that this bacterium was related to Aquidulcibacter paucihalophilus TH1-2(T) and Asprobacter aquaticus DRW22-8(T) with 91.3 and 89.7% sequence similarity, respectively. Four unidentified glycolipids were detected as the major polar lipids and, unlike all described members of the family Caulobacteraceae, phosphatidylglycerol was absent. The major fatty acids were summed feature 8 (C-18,omega 7c/C-18:1 omega 6c), summed feature 9 (iso-C-17.1 omega 9c/C-16:0 10-methyl), C-16:0 and summed feature 3 (C-16:1 omega 6c/C-16:1 omega 7c). The major respiratory quinone was Q-10. The G+C content of the genomic DNA was 63.5%. Based on the present taxonomic characterization, strain 0127_4(T) represents a novel species of a new genus, Terricaulis silvestris gen. nov., sp. nov. The type strain of Terricaulis silvestris is 0127_4(T) (=DSM 104635(T)=CECT 9243(T)).