Arthrobacter livingstonensis sp. nov. and Arthrobacter cryotolerans sp. nov., salt-tolerant and psychrotolerant species from Antarctic soil

Abstract

Two novel cold-tolerant, Gram-stain-positive, motile, facultatively anaerobic bacterial strains, LI2 T and LI3 T , were isolated from moss-covered soil from Livingston Island, Antarctica, near the Bulgarian station St Kliment Ohridski. A rod-coccus cycle was observed for both strains. 16S rRNA gene sequence analysis revealed an affiliation to the genus Arthrobacter, with the highest similarity to Arthrobacter stackebrandtii and Arthrobacter psychrochitiniphilus for strain LI2 T (97.8and 97.7 % similarity to the respective type strains) and to Arthrobacter kerguelensis and Arthrobacter psychrophenolicus for strain LI3 T (97.4 and 97.3 % similarity to the respective type strains). The growth temperature range was "6 to 28 6C for LI2 T and "6 to 24 6C for LI3 T , with an optimum at 16 6C for both strains. Growth occurred at 0-10 % (w/v) NaCl, with optimum growth at 0-1 % (w/v) for LI2 T and 0.5-3 % (w/v) for LI3T . The pH range for growth was pH 4-9.5 with an optimum of pH 8 for LI2T and pH 6.5 for LI3T . The predominant fatty acids were anteiso-C 15 : 0 , C 18 : 0 and anteiso-C 17 : 0 for LI2 T and anteiso-C 15 : 0 and C 18 : 0 for LI3

Review of the taxonomy of the genus Arthrobacter, emendation of the genus Arthrobacter sensu lato, proposal to reclassify selected species of the genus Arthrobacter in the novel genera Glutamicibacter gen. nov., Paeniglutamicibacter gen. nov., Pseudoglutamicibacter gen. nov., Paenarthrobacter gen. nov. and Pseudarthrobacter gen. nov., and emended description of Arthrobacter roseus

“…Rather separate positions within the tree are occupied by A. woluwensis and A. sanguinis. The existence of these major sublines is also shown in other phylogenetic analyses, even though the complete set of species of the genus Arthrobacter was not always included in these calculations (Ganzert et al, 2011;Busse et al, 2012;Zhang et al, 2012).…”

“…This affiliation is in agreement with chemotaxonomic traits of this species, including its quinone system (ubiquinone Q-10 predominant), fatty acid profile (hydroxy fatty acids present, C 18 : 1 and C 19 : 0 cyclo predominant) and a polar lipid profile that suggests the presence of phosphatidylethanolamine (PE), monomethylethanolamine, phosphatidylglycerol (PG), diphosphatidylglycerol (DPG) and phosphatidylcholine (Collins, 1986). Phylogenetic analyses employing the neighbour-joining algorithm and embracing the vast majority of species of the genus Arthrobacter (Ding et al, 2009;Ganzert et al, 2011;Yassin et al, 2011b;Margesin et al, 2012) do not indicate a stable internal structure of the genus. This is indicated by the fact that many branching nodes are not supported by high bootstrap values (.70 %) and numerous nodes were not found with the maximumlikelihood or maximum-parsimony algorithm.…”

“…Hence, reanalyses of the polar lipid profiles of these three species would be desirable in order to confirm these unexpected traits. A. livingstonensis and Arthrobacter cryotolerans were reported to contain PG only (Ganzert et al, 2011), but a polar lipid profile with only a single lipid appears unlikely, because bacterial cytoplasmic membranes are generally composed of several different lipid components. However, in the corresponding paper, the polar lipid profiles of the latter two species were incomplete.…”

“…However, in phylogenetic trees, A. crystallopoietes is usually the sole species on a separate branch ( Fig. 1; Ding et al, 2009;Ganzert et al, 2011;Yassin et al, 2011b;Margesin et al, 2012;Busse et al, 2012). The peptidoglycan structure also does not assign this species clearly to the 'A.…”

Arthrobacter echini sp. nov., isolated from the gut of a purple sea urchin, Heliocidaris crassispina

“…At the time of writing, the genus Arthrobacter comprised 87 recognized species. Although most Arthrobacter species have been isolated from sediments (Chen et al, 2005;Pindi et al, 2010;Roh et al, 2008) or soils (Ganzert et al, 2011;Park et al, 2014;Zhang et al, 2010), several…”