Please cite this article in press as: H. Ahnia, et al., Bradyrhizobium algeriense sp. nov., a novel species isolated from effective nodules of Retama sphaerocarpa from Northeastern Algeria, Syst. Appl. Microbiol. (2018), https://doi.org/10.1016/j.syapm.2018.03.004 ARTICLE IN PRESS G Model SYAPM-25905; No. of Pages 7 Systematic and Applied Microbiology xxx (2018) xxx–xxx Contents lists available at ScienceDirect Systematic and Applied Microbiology j ourna l h omepage: www.elsevier.de/syapm Bradyrhizobium algeriense sp. nov., a novel species isolated from effective nodules of Retama sphaerocarpa from Northeastern Algeria Hadjira Ahnia a , Yasmina Bourebaba a , David Durán b,c , Farida Boulila a,∗∗ , José M Palacios b,c , Luis Rey b,c , Tomás Ruiz-Argüeso b,c , Abdelghani Boulila a , Juan Imperial b,c,d,∗ a Laboratoire d’Ecologie Microbienne, Faculté des Sciences de la Nature et de la Vie, Université de Bejaia, 06000 Bejaia, Algeria b Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) – Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM, 28223 Pozuelo de Alarcón, Madrid, Spain c Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, UPM, 28040 Madrid, Spain d Instituto de Ciencias Agrarias, CSIC, 28006 Madrid, Spain a r t i c l e i n f o Article history: Received 30 December 2017 Received in revised form 14 March 2018 Accepted 22 March 2018 Keywords: Bradyrhizobium Retama sphaerocarpa Symbiovar retamae ANIm MALDI-TOF Phylogenetic analysis a b s t r a c t We have characterized genetic, phenotypic and symbiotic properties of bacterial strains previously iso- lated from nitrogen-fixing nodules of Retama sphaerocarpa from Northern Algeria. Phylogenetic analyses of 16S rRNA genes and three concatenated housekeeping genes, recA, atpD and glnII, placed them in a new divergent group that is proposed to form a new Bradyrhizobium species, Bradyrhizobium algeriense sp. nov. (type strain RST89 T , LMG 27618 and CECT 8363). Based on these phylogenetic markers and on genomic identity data derived from draft genomic sequences, Bradyrhizobium valentinum LmjM3 T , Bradyrhizobium lablabi CCBAU 23086 T , Bradyrhizobium retamae Ro19 T , and Bradyrhizobium jicamae PAC68 T are the closest relatives of B. algeriense RST89 T , with sequence identities of 92–94% and Average Nucleotide Identities (ANIm) under 90%, well below the 95–96% species circumscription threshold. Likewise, a comparison of whole-cell proteomic patterns, estimated by Matrix-Assisted Laser Desorption/Ionization-Time-of-Flight (MALDI-TOF) mass spectrometric analysis, yielded almost identical spectra between B. algeriense strains but significant differences with B. valentinum, Bradyrhizobium paxllaeri, Bradyrhizobium icense, B. lablabi, B. jicamae and B. retamae. A phylogenetic tree based on symbiotic gene nodC revealed that the B. algeriense sequences cluster with sequences from the Bradyrhizobium symbiovar retamae, previously defined with B. retamae strains isolated from Retama monosperma. B. algeriense strains were able to establish effective symbioses with Retama raetam, Lupinus micranthus, Lupinus albus and Genista numidica, but not with Lupinus angustifolius or Glycine max. © 2018 Elsevier GmbH. All rights reserved. Introduction Retama spp. (tribe Genisteae, family Fabaceae) are shrubs native to the Mediterranean basin and adapted to grow under arid con- ditions. They are able to produce N 2 -fixing root nodules, which makes them useful for restoration of arid or semiarid degraded ecosystems [30]. All endosymbiotic bacteria isolated from Retama ∗ Corresponding author at: Instituto de Ciencias Agrarias, CSIC, Serrano 115 bis, 28006 Madrid, Spain. ∗∗ Corresponding author at: Laboratoire d’Ecologie Microbienne, Faculté des Sci- ences de la Nature et de la Vie, Université Abderrahmane Mira, 06000 Béjaïa, Algeria. E-mail addresses: abadifarida@yahoo.fr (F. Boulila), juan.imperial@csic.es (J. Imperial). nodules belong to the genus Bradyrhizobium [2]. Isolates from Retama sphaerocarpa growing in central Spain have been classi- fied as Bradyrhizobium canariense [31]. Isolates from R. sphaerocarpa growing in Bouarfa (Morocco) and Ciudad Real (Spain), and iso- lates from Retama monosperma growing in Ras el Ma (Morocco) have been recently included in the Bradyrhizobium retamae species [14]. One hundred twenty-five isolates from root nodules of Retama raetam and R. sphaerocarpa, native of Northeastern Algeria, were described as Bradyrhizobium sp. [2]. Some of the R. sphaerocarpa isolates appeared to differ from the above-mentioned species, and have been characterized in this work by molecular, phenotypic and phylogenetic methods. These R. spaherocarpa strains are proposed to define the novel Bradyrhizobium algeriense sp. nov. https://doi.org/10.1016/j.syapm.2018.03.004 0723-2020/© 2018 Elsevier GmbH. All rights reserved.