Frankia coriariae sp. nov., an infective and effective microsymbiont isolated from Coriaria japonica.

ABSTRACT

The taxonomic description of a nitrogen-fixing actinobacterium, strain BMG5.1T, as a novel species within the genus Frankia was based on a polyphasic approach. The strain was isolated from the root nodules of Coriaria japonica, and it fulfilled Koch's postulates by inducing effective nodules on Coriaria spp. and Datisca spp. Based on phenotypic and chemotaxonomic features, strain BMG5.1T is distinguishable from all other species of the genus Frankia. It is characterized by the presence of phosphatidylinositol, diphosphatidylglycerol, phosphatidylglycerol and glycophospholipids in its polar lipids; galactose, glucose, mannose and a trace of ribose as cellular sugars; meso-diaminopimelic acid as cell-wall peptidoglycan; C18  1ω9c as major fatty acid (>30 %); and MK-9(H6) (44.7 %) as predominant isoprenolog (>30 %). The 16S rRNA gene sequence similarities and the digital DNA-DNA hybridization values between the described novel strain and strains of the other species of the genus Frankia correspond to a range of 97-98.4 % and 22.1-24 %, respectively. The DNA G+C content is 70.2  mol%. On the basis of these results, strain BMG5.1T (=CECT 9032T=DSM 100624T) is proposed as the type strain of a novel species of the genus Frankia, named Frankia coriariae sp. nov.