title: Phaseolus vulgaris seed-borne endophytic community with novel bacterial species such as Rhizobium endophyticum sp. nov.
abstract: The bacterial endophytic community present in different Phaseolus vulgaris (bean) cultivars was analyzed by 16S ribosomal RNA gene sequences of cultured isolates derived from surface disinfected roots and immature seeds. Isolated endophytes from tissue-macerates belonged to over 50 species in 24 different genera and some isolates from Acinetobacter, Bacillus, Enterococcus, Nocardioides, Paracoccus, Phyllobacterium, and Sphingomonas seem to correspond to new lineages. Phytate solubilizing bacteria were identified among Acinetobacter, Bacillus and Streptomyces bean isolates, phytate is the most abundant reserve of phosphorus in bean and in other seeds. Endophytic rhizobia were not capable of forming nodules. A novel rhizobial species Rhizobium endophyticum was recognized on the basis of DNA-DNA hybridization, sequence of 16S rRNA, recA, rpoB, atpD, dnaK genes, plasmid profiles, and phenotypic characteristics. R. endophyticum is capable of solubilizing phytate, the type strain is CCGE2052 (ATCC BAA-2116; HAMBI 3153) that became fully symbiotic by acquiring the R. tropici CFN299 symbiotic plasmid.
authors.affiliation: Centro de Ciencias Genómicas, UNAM, Cuernavaca, Morelos, Mexico.
authors.forename: Aline
authors.initials: A
authors.lastname: López-López
authors.forename: Marco A
authors.initials: MA
authors.lastname: Rogel
authors.forename: Ernesto
authors.initials: E
authors.lastname: Ormeño-Orrillo
authors.forename: Julio
authors.initials: J
authors.lastname: Martínez-Romero
authors.forename: Esperanza
authors.initials: E
authors.lastname: Martínez-Romero
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D001426:Bacterial Proteins / Q000235:genetics; D044822:Biodiversity; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D027805:Phaseolus / Q000382:microbiology*; D010802:Phylogeny; D010833:Phytic Acid / Q000378:metabolism; D018517:Plant Roots / Q000382:microbiology; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012639:Seeds / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D013559:Symbiosis
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D010833:Phytic Acid