Microvirga ossetica sp. nov., a species of rhizobia isolated from root nodules of the legume species Vicia alpestris Steven

Abstract

Gram-stain-negative strains V5/3MT, V5/5K, V5/5M and V5/13 were isolated from root nodules of Vicia alpestris plants growing in the North Ossetia region (Caucasus). Sequencing of the partial 16S rRNA gene (rrs) and four housekeeping genes (dnaK, gyrB, recA and rpoB) showed that the isolates from V. alpestris were most closely related to the species Microvirga zambiensis (order Rhizobiales, family Methylobacteriaceae) which was described for the single isolate from root nodule of Listia angolensis growing in Zambia. Sequence similarities between the Microvirga-related isolates and M. zambiensis WSM3693T ranged from 98.5 to 98.7 % for rrs and from 79.7 to 95.8 % for housekeeping genes. Cellular fatty acids of the isolates V5/3MT, V5/5K, V5/5M and V5/13 included important amounts of C18 : 1ω7c (54.0-67.2 %), C16 : 0 (6.0-7.8 %), C19 : 0 cyclo ω8c (3.1-10.2 %), summed feature 2 (comprising one or more of iso-C16 : 1 I, C14 : 0 3-OH and unknown ECL 10.938, 5.8-22.5 %) and summed feature 3 (comprising C16 : 1ω7c and/or iso-C15 : 02-OH, 2.9-4.0 %). DNA-DNA hybridization between the isolate V5/3MT and M. zambiensis WSM3693T revealed DNA-DNA relatedness of 35.3 %. Analysis of morphological and physiological features of the novel isolates demonstrated their unique phenotypic profile in comparison with reference strains from closely related species of the genus Microvirga. On the basis of genotypic and phenotypic analysis, a novel species named Microvirga ossetica sp. nov. is proposed. The type strain is V5/3MT (=LMG 29787T=RCAM 02728T). Three additional strains of the species are V5/5K, V5/5M and V5/13.

Microvirga tunisiensis sp. nov., a root nodule symbiotic bacterium isolated from Lupinus micranthus and L. luteus grown in Northern Tunisia

“…zambiensis differed from the rest by having C20:0 ω6,9c, and also differed from LmiM8 by having C14:0 and C18:1 ω7c 11-methyl. The obtained patterns are consistent with previous reports for Microvirga strains [30,34] and observed differences may be due to the different cultivation conditions used.…”

“…The same authors obtained a collection of 43 isolates of L. luteus from the same region, out of which 41 belonged to the genus Bradyrhizobium and just two to Microvirga [26]. The genus Microvirga currently comprises eighteen species [1,4,11,13,20,21,27,30,33,34,[37][38][39], of which only four have been described as effective root nodule bacteria: M. lotononidis and M. zambiensis isolated from Listia angolensis nodules [4], M. lupini, from Lupinus texensis [4] and M. vignae from Vigna unguiculata [27]. Through in-depth analysis of genetic, genomic and phenotypic data, we show here that Microvirga strains isolated from the root nodules of Northern Tunisian L. micranthus and L. luteus plants are representatives of a new symbiotic species that we propose to designate as Microvirga tunisiensis.…”

Polyphasic characterization of forage legumes root nodule bacteria isolated from semiarid region in Brazil

“…Recently, β-Proteobacteria members were isolated from Stylosanthes nodules (Chaves et al, 2016), expanding the knowledge of the symbiotic capacity of Stylosanthes species. In the present study, we report the symbiotic capacity of S. capitata to form symbiosis with Microvirga, an α-Proteobacteria genus with members reported as legume-nodulating symbionts (Ardley et al, 2012;Radl et al, 2014;Msaddak et al, 2017a, b;Safronova et al, 2017).…”

Phylogeny and Phylogeography of Rhizobial Symbionts Nodulating Legumes of the Tribe Genisteae

“…other than lupins, however, aside from lupins, rhizobia belonging to this genus were also isolated from Listia angolensis in Zambia, Vigna sp. in Brazil, and from Vicia alpestris in the Caucasus, Russia [ 87 , 168 , 169 ].…”