title: The symbiovar trifolii of Rhizobium bangladeshense and Rhizobium aegyptiacum sp. nov. nodulate Trifolium alexandrinum in Egypt.
abstract: In the present work we analyzed the taxonomic status of several Rhizobium strains isolated from Trifolium alexandrinum L. nodules in Egypt. The 16S rRNA genes of these strains were identical to those of Rhizobium bangladeshense BLR175(T) and Rhizobium binae BLR195(T). However, the analyses of recA and atpD genes split the strains into two clusters. Cluster II strains are identified as R. bangladeshense with >98% similarity values in both genes. The cluster I strains are phylogenetically related to Rhizobium etli CFN42(T) and R. bangladeshense BLR175(T), but with less than 94% similarity values in recA and atpD genes. DNA-DNA hybridization analysis showed 42% and 48% average relatedness between the strain 1010(T) from cluster I with respect to R. bangladeshense BLR175(T) and R. etli CFN42(T), respectively. Phenotypic characteristics of cluster I strains also differed from those of their closest related Rhizobium species. Analysis of the nodC gene showed that the strains belong to two groups within the symbiovar trifolii which was identified in Egypt linked to the species R. bangladeshense. Based on the genotypic and phenotypic characteristics, the group I strains belong to a new species for which the name Rhizobium aegyptiacum sp. nov. (sv. trifolii) is proposed, with strain 1010(T) being designated as the type strain (= USDA 7124(T)=LMG 29296(T)=CECT 9098(T)).
authors.affiliation: Genetic Engineering and Biotechnology Research Institute, City for Scientific Research and Technology Applications (SRTA-City), Alexandria, Egypt.
authors.forename: Abdelaal
authors.initials: A
authors.lastname: Shamseldin
authors.affiliation: Departamento de Microbiología y Genética, Universidad de Salamanca, Salamanca, Spain.
authors.forename: Lorena
authors.initials: L
authors.lastname: Carro
authors.affiliation: Instituto de Recursos Naturales y Agrobiología de Salamanca, Consejo Superior de Investigaciones Científicas (IRNASA-CSIC), Salamanca, Spain; Unidad Asociada Grupo de Interacción Planta-Microorganismo Universidad de Salamanca-IRNASA-CSIC, Spain.
authors.forename: Alvaro
authors.initials: A
authors.lastname: Peix
authors.affiliation: Departamento de Microbiología y Genética, Universidad de Salamanca, Salamanca, Spain; Unidad Asociada Grupo de Interacción Planta-Microorganismo Universidad de Salamanca-IRNASA-CSIC, Spain. Electronic address: evp@usal.es.
authors.forename: Encarna
authors.initials: E
authors.lastname: Velázquez
authors.affiliation: Genetic Engineering and Biotechnology Research Institute, City for Scientific Research and Technology Applications (SRTA-City), Alexandria, Egypt.
authors.forename: Hassan
authors.initials: H
authors.lastname: Moawad
authors.affiliation: BioTechnology Institute and Department of Soil, Water & Climate, University of Minnesota, St. Paul, USA. Electronic address: sadowsky@umn.edu.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Sadowsky
mesh_terms: D001482:Base Composition; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D004534:Egypt; D020043:Genes, Essential / Q000235:genetics; D009693:Nucleic Acid Hybridization; D010641:Phenotype; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D011938:Rec A Recombinases / Q000235:genetics; D012231:Rhizobium / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D053204:Root Nodules, Plant / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D013559:Symbiosis; D014157:Transcription Factors / Q000235:genetics; D029921:Trifolium / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D014157:Transcription Factors; D011938:Rec A Recombinases
keywords: Egypt; Rhizobium; Rhizobium aegyptiacum; Rhizobium blangladeshense; Symbiovar trifolii; Trifolium alexandrinum