Sinorhizobium arboris sp nov and Sinorhizobium kostiense sp nov., isolatedfrom leguminous trees in Sudan and Kenya

SDS-PAGE of total bacterial proteins was applied to the classification of 2 5 Sudanese and five Kenyan strains isolated from the root nodules of Acacia senegal and Prosopis chilensis. Twenty strains were also studied by multil ocus enzyme electrophoresis (MLEE) and the whole 16S rRNA gene was sequence d from two strains representing the two major clusters. These results, toge ther with the previously reported numerical taxonomy analysis, pulsed-field gel electrophoresis studies, DNA-DNA dot-blot hybridization, genomic finge rprinting using repetitive sequence-based PCR, DNA base composition analysi s, DNA-DNA reassociation analysis, partial sequencing of the 16S rRNA gene and RFLP analysis of the amplified 16S rRNA gene, showed that all 30 strain s belong to the genus Sinorhizobium. Two of the strains grouped with Sinorh izobium saheli and seven with Sinorhizobium terangae, while the rest did no t cluster with any of the established species. The majority of the strains formed two phenotypically and genotypically distinct groups and we therefor e propose that these strains should be classified as two new species. Sinor hizobium arboris sp. nov. and Sinorhizobium kostiense sp. nov.