title: Microvirga lupini sp. nov., Microvirga lotononidis sp. nov. and Microvirga zambiensis sp. nov. are alphaproteobacterial root-nodule bacteria that specifically nodulate and fix nitrogen with geographically and taxonomically separate legume hosts.
abstract: Strains of Gram-negative, rod-shaped, non-spore-forming bacteria were isolated from nitrogen-fixing nodules of the native legumes Listia angolensis (from Zambia) and Lupinus texensis (from Texas, USA). Phylogenetic analysis of the 16S rRNA gene showed that the novel strains belong to the genus Microvirga, with ≥ 96.1% sequence similarity with type strains of this genus. The closest relative of the representative strains Lut6(T) and WSM3557(T) was Microvirga flocculans TFB(T), with 97.6-98.0% similarity, while WSM3693(T) was most closely related to Microvirga aerilata 5420S-16(T), with 98.8% similarity. Analysis of the concatenated sequences of four housekeeping gene loci (dnaK, gyrB, recA and rpoB) and cellular fatty acid profiles confirmed the placement of Lut6(T), WSM3557(T) and WSM3693(T) within the genus Microvirga. DNA-DNA relatedness values, and physiological and biochemical tests allowed genotypic and phenotypic differentiation of Lut6(T), WSM3557(T) and WSM3693(T) from each other and from other Microvirga species with validly published names. The nodA sequence of Lut6(T) was placed in a clade that contained strains of Rhizobium, Mesorhizobium and Sinorhizobium, while the 100% identical nodA sequences of WSM3557(T) and WSM3693(T) clustered with Bradyrhizobium, Burkholderia and Methylobacterium strains. Concatenated sequences for nifD and nifH show that the sequences of Lut6(T), WSM3557(T) and WSM3693(T) were most closely related to that of Rhizobium etli CFN42(T) nifDH. On the basis of genotypic, phenotypic and DNA relatedness data, three novel species of Microvirga are proposed: Microvirga lupini sp. nov. (type strain Lut6(T) =LMG 26460(T) =HAMBI 3236(T)), Microvirga lotononidis sp. nov. (type strain WSM3557(T) =LMG 26455(T) =HAMBI 3237(T)) and Microvirga zambiensis sp. nov. (type strain WSM3693(T) =LMG 26454(T) =HAMBI 3238(T)).
authors.affiliation: Centre for Rhizobium Studies, Murdoch University, 90 South Street, Murdoch, WA 6150, Australia.
authors.forename: Julie K
authors.initials: JK
authors.lastname: Ardley
authors.affiliation: Department of Biological Sciences, State University of New York, Binghamton, 4400 Vestal Parkway, Vestal, NY 13850, USA.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Parker
authors.affiliation: Microbiology Laboratory, University of Gent, Sint-Pietersnieuwstraat 25, B-9000 Ghent, Belgium.
authors.forename: Sofie E
authors.initials: SE
authors.lastname: De Meyer
authors.affiliation: Separation Science and Metabolomics Laboratory, Murdoch University, 90 South Street, Murdoch, WA 6150, Australia.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Trengove
authors.affiliation: Centre for Rhizobium Studies, Murdoch University, 90 South Street, Murdoch, WA 6150, Australia.
authors.forename: Graham W
authors.initials: GW
authors.lastname: O'Hara
authors.affiliation: Centre for Rhizobium Studies, Murdoch University, 90 South Street, Murdoch, WA 6150, Australia.
authors.forename: Wayne G
authors.initials: WG
authors.lastname: Reeve
authors.affiliation: Department of Agriculture Western Australia, 3 Baron Hay Court, South Perth, WA 6151, Australia.|Centre for Rhizobium Studies, Murdoch University, 90 South Street, Murdoch, WA 6150, Australia.
authors.forename: Ron J
authors.initials: RJ
authors.lastname: Yates
authors.affiliation: Centre for Rhizobium Studies, Murdoch University, 90 South Street, Murdoch, WA 6150, Australia.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Dilworth
authors.affiliation: Microbiology Laboratory, University of Gent, Sint-Pietersnieuwstraat 25, B-9000 Ghent, Belgium.
authors.forename: Anne
authors.initials: A
authors.lastname: Willems
authors.affiliation: Centre for Rhizobium Studies, Murdoch University, 90 South Street, Murdoch, WA 6150, Australia.
authors.forename: John G
authors.initials: JG
authors.lastname: Howieson
mesh_terms: D015373:Bacterial Typing Techniques; D004269:DNA, Bacterial / Q000235:genetics; D007887:Fabaceae / Q000382:microbiology*; D005227:Fatty Acids / Q000032:analysis; D042082:Methylobacteriaceae / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D008969:Molecular Sequence Data; D009586:Nitrogen Fixation; D010802:Phylogeny; D055170:Plant Root Nodulation; D018517:Plant Roots / Q000382:microbiology; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013781:Texas; D015024:Zambia
chemical_list: D004269:DNA, Bacterial; D005227:Fatty Acids; D012336:RNA, Ribosomal, 16S