Rhizobium sullae sp. nov. (formerly "Rhizobium hedysari"), the root-nodule microsymbiont of Hedysarum coronarium L.

This work is the completion of a series of reports describing the nitrogen-fixing bacterial symbionts of sulla (Hedyzarum coronarium L., Leguminosae) and providing the grounds for their proposal as a new taxon. The introduction summarizes a large amount of previous evidence gathered on the physiology, genetics and ecology of such organisms, which have in the past been referred to provisionally as "Rhizobium hedysari". Upon adding 16S rRNA sequencing, amplified rDNA restriction analysis of the rrn operon, DNA-DNA hybridization homology and analysis of low-molecular-mass RNA species, it is concluded that the group of strains that specifically nodulate sulla consists of a coherent set of isolates that differ from previously described rhizobia to an extend that warrants the construction of the species boundary. The name Rhizobium sullae sp. nov. is proposed, with isolate IS123T (=USDA4950T = DSM 14623T) as the type strain.

Autor/Institut
Dipartimento di Biotecnologie Agrarie, Universita di Padova, Agripolis, Strada Romea16, 35020 Legnaro, Padova, Italy; Molecular Microbiology Group, Institute of Radiochemistry, Forschungszentrum Rossendorf, D-01314 Dresden, Germany; Departamento de Microbio-logia y Genetica, Universidad de Salamanca, Avda del Campo Charro s/n, 37007 Salamanca, Spain; Department of Microbiology, Michigan State University, East Lansing, MI 48824, USA; Dipartimento di Chimica e Biotecnologie Agrarie, Universita di Pisa, via del Borghetto 80, Pisa, Italy