Halomonas radicis sp. nov., isolated from Arthrocnemum macrostachyum growing in the Odiel marshes(Spain) and emended descriptions of Halomonas xinjiangensis and Halomonas zinciduran

21 páginas, 2 tablas, 1 figura

Strain EAR18T was isolated as an endophyte from the roots of a halophyte plant, Arthrocnemum macrostachyum, growing in the Odiel marshes (Huelva, Spain). Strain EAR18T was Gram staining-negative, motile, non-spore forming, and aerobic rods. It optimally grew on TSA medium supplemented with 2.5 % NaCl (w/v), at pH 7 and 30 ºC for 48 h. It tolerated NaCl from 0 % to 25 % (w/v). It presented Q9 as the major quinone and C19:0 cyclo ω8c, Summed feature 8 (C18:1 ω7c and/or C18:1 ω6c), and C16:0 as the predominant fatty acids. The polar lipids profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and four unindentified phospholipids. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain EAR18T formed a well-supported clade with species Halomonas zincidurans B6T and Halomonas xinjiangensis TRM 0175T (similarities of 98.3 % and 96.1 % respectively). Furthermore, dDDH resulted in values of 20.4 % with H. xinjiangensis TRM 0175T and 35.50 % with H. incidurans B6T, and ANIb/ANIm results in values of 73.8 %/84.2 % with H. xinjiangensis TRM 0175T and 86.8 %/89.4 % with H. zincidurans B6T. Based on phylogeny and differential phenotypic properties showed when compared with the closest related species, strain EAR18T is suggested to represent a new species in the genus Halomonas, for which the name Halomonas radicis sp. nov. is proposed. The type strain is EAR18T (=CECT 9077T=LMG 29859T). The whole genome was sequenced, and it has a total length of 4.6 Mbp and a G+C content of 64.9 mol%.

This work has been possible thanks to Junta de Andalucía (P11-RNM-7274MO project) and INIA (RTA 2012-0006-C03-03 project).

Peer reviewed