title: Recovery of symbiotic nitrogen fixing acacia rhizobia from Merzouga Desert sand dunes in South East Morocco--Identification of a probable new species of Ensifer adapted to stressed environments.
abstract: Bacteria capable of nodulating Acacia tortilis and A. gummifera could be recovered from sand dunes collected in the Moroccan Merzouga desert. The trapping approach enabled the recovery of 17 desert rhizobia that all clustered within the Ensifer (Sinorhizobium) genus. Four isolates of the dominant genotype comprising 15 strains as well as 2 divergent strains were further characterized by MLSA. Phylogenetic analyzes indicated that the dominant genetic type was belonging to a new and yet undefined species within the Ensifer genus. Interestingly, housekeeping gene phylogenies showed that this possibly new species is also present in another desert but in India. Phylogenetic analyses of nifH and nodC sequences showed high sequence conservation among the Moroccan strains belonging to the dominant genotype but high divergence with sequences from Indian isolates suggesting acquisition of symbiotic genes through Horizontal Gene Transfer. These desert rhizobia were capable of growing in media containing high salt concentrations, under high pH and most of the strains showed growth at 45°C. Only recovered from desert type of Biome, yet, this new taxon appears particularly adapted to such harsh environment.
authors: Laboratoire de Microbiologie et de Biologie Moléculaire, Faculté des Sciences, Université Mohammed V - Agdal, Rabat, Morocco.
authors: Ilham
authors: I
authors: Sakrouhi
authors: Laboratoire de Microbiologie et de Biologie Moléculaire, Faculté des Sciences, Université Mohammed V - Agdal, Rabat, Morocco; Institut de Recherche pour le Développement, Laboratoire des Symbioses Tropicales et Méditerranéennes, UMR113 IRD-CIRAD-SupAgro-UM-INRA, Campus International de Baillarguet, 34 398 Montpellier Cedex 5, France.
authors: Meryem
authors: M
authors: Belfquih
authors: Laboratoire de Microbiologie et de Biologie Moléculaire, Faculté des Sciences, Université Mohammed V - Agdal, Rabat, Morocco.
authors: Laïla
authors: L
authors: Sbabou
authors: Laboratoire de Microbiologie et de Biologie Moléculaire, Faculté des Sciences, Université Mohammed V - Agdal, Rabat, Morocco.
authors: Patricia
authors: P
authors: Moulin
authors: Laboratoire de Microbiologie et de Biologie Moléculaire, Faculté des Sciences, Université Mohammed V - Agdal, Rabat, Morocco.
authors: Gilles
authors: G
authors: Bena
authors: Laboratoire de Microbiologie et de Biologie Moléculaire, Faculté des Sciences, Université Mohammed V - Agdal, Rabat, Morocco.
authors: Abdelkarim
authors: A
authors: Filali-Maltouf
authors: Laboratoire de Microbiologie et de Biologie Moléculaire, Faculté des Sciences, Université Mohammed V - Agdal, Rabat, Morocco; Institut de Recherche pour le Développement, Laboratoire des Symbioses Tropicales et Méditerranéennes, UMR113 IRD-CIRAD-SupAgro-UM-INRA, Campus International de Baillarguet, 34 398 Montpellier Cedex 5, France. Electronic address: Antoine.le-quere@ird.fr.
authors: Antoine
authors: A
authors: Le Quéré
mesh_terms: D000045:Acacia / Q000382:microbiology*; D002244:Carbon / Q000737:chemistry; D003889:Desert Climate; D006863:Hydrogen-Ion Concentration; D058889:Molecular Typing; D009018:Morocco; D009584:Nitrogen / Q000737:chemistry; D009586:Nitrogen Fixation; D010641:Phenotype; D010710:Phosphates / Q000737:chemistry; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012231:Rhizobium / Q000145:classification* / Q000302:isolation & purification / Q000502:physiology*; D013312:Stress, Physiological
chemical_list: D010710:Phosphates; D012336:RNA, Ribosomal, 16S; D002244:Carbon; D009584:Nitrogen
keywords: Acacia rhizobia; Africa; Ensifer; Hot desert; Phylogeny; Symbiosis