title: A purL mutant of Sinorhizobium fredii HH103 is symbiotically defective and altered in its lipopolysaccharide.
abstract: The pleiotropic phenotype of an auxotrophic purL mutant (SVQ295) of Sinorhizobium fredii HH103 has been investigated. SVQ295 forms colonies that are translucent, produce more slime and absorb less Congo red than those of wild-type strain HH103. SVQ295 did not grow in minimal medium unless the culture was supplemented with thiamin and adenine or with thiamin and AICA-riboside (5-aminoimidazole-4-carboxamide 1-beta-D-ribofuranoside), an intermediate of purine biosynthesis. Bacterial cultures supplemented with AICA-riboside or adenine reached the same culture density, although the doubling time of SVQ295 cultures containing AICA-riboside was clearly longer. S. fredii SVQ295 induced pseudonodules on Glycine max and failed to nodulate six different legumes. On Glycyrrhiza uralensis, however, nodules showing nitrogenase activity and containing infected plant cells were formed. SVQ295 showed auto-agglutination when grown in liquid TY medium and its lipopolysaccharide (LPS) electrophoretic profile differed from that of its parental strain HH103-1. In addition, four monoclonal antibodies that recognize the LPS of S. fredii HH103 failed to recognize the LPS produced by SVQ295. In contrast, (1)H-NMR spectra of K-antigen capsular polysaccharides (KPS) produced by SVQ295 and the wild-type strain HH103 were similar. Co-inoculation of soybean plants with SVQ295 and SVQ116 (a nodA mutant derivative of HH103) produced nitrogen-fixing nodules that were only occupied by SVQ116.
authors.affiliation: Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Apdo 1095, 41080 Sevilla, Spain.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Buendía-Clavería
authors.affiliation: Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Apdo 1095, 41080 Sevilla, Spain.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Moussaid
authors.affiliation: Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Apdo 1095, 41080 Sevilla, Spain.
authors.forename: F Javier
authors.initials: FJ
authors.lastname: Ollero
authors.affiliation: Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Apdo 1095, 41080 Sevilla, Spain.
authors.forename: José M
authors.initials: JM
authors.lastname: Vinardell
authors.affiliation: Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Apdo 1095, 41080 Sevilla, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Torres
authors.affiliation: Departamento de Biología Celular, Facultad de Biología, Universidad de Sevilla, Av. Reina Mercedes s/n, 41012 Sevilla, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Moreno
authors.affiliation: Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla, Apdo 553, 41071 Sevilla, Spain.
authors.forename: Antonio M
authors.initials: AM
authors.lastname: Gil-Serrano
authors.affiliation: Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla, Apdo 553, 41071 Sevilla, Spain.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Rodríguez-Carvajal
authors.affiliation: Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla, Apdo 553, 41071 Sevilla, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Tejero-Mateo
authors.affiliation: Department of Molecular Microbiology, John Innes Centre, Norwich NR4 7UH, UK.
authors.forename: Jan L
authors.initials: JL
authors.lastname: Peart
authors.affiliation: Department of Molecular Microbiology, John Innes Centre, Norwich NR4 7UH, UK.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Brewin
authors.affiliation: Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Apdo 1095, 41080 Sevilla, Spain.
authors.forename: José E
authors.initials: JE
authors.lastname: Ruiz-Sainz
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D008070:Lipopolysaccharides / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D051381:Rats; D020579:Sinorhizobium / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D013025:Glycine max / Q000382:microbiology; D013559:Symbiosis / Q000235:genetics
chemical_list: D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D004269:DNA, Bacterial; D008070:Lipopolysaccharides