Please cite this article in press as: N.E. Kimes, et al., Pseudorhizobium pelagicum gen. nov., sp. nov. isolated from a pelagic Mediterranean zone, Syst. Appl. Microbiol. (2015), http://dx.doi.org/10.1016/j.syapm.2015.05.003 ARTICLE IN PRESS G Model SYAPM-25701; No. of Pages 7 Systematic and Applied Microbiology xxx (2015) xxx–xxx Contents lists available at ScienceDirect Systematic and Applied Microbiology j ourna l h omepage: www.elsevier.de/syapm Pseudorhizobium pelagicum gen. nov., sp. nov. isolated from a pelagic Mediterranean zone  Nikole E. Kimes a , Mario López-Pérez a , José David Flores-Félix b , Martha-Helena Ramírez-Bahena c,d , José M. Igual c,d , Alvaro Peix c,d , Francisco Rodriguez-Valera a , Encarna Velázquez b,d,∗ a Evolutionary Genomics Group, División de Microbiología, Universidad Miguel Hernández, Apartado 18, San Juan 03550, Alicante, Spain b Departamento de Microbiología y Genética. Universidad de Salamanca, Salamanca, Spain c Instituto de Recursos Naturales y Agrobiología de Salamanca, Consejo Superior de Investigaciones Científicas (IRNASA-CSIC), Salamanca, Spain d Unidad Asociada Grupo de Interacción Planta-Microorganismo Universidad de Salamanca-IRNASA-CSIC, Salamanca, Spain a r t i c l e i n f o Article history: Received 19 January 2015 Received in revised form 15 May 2015 Accepted 19 May 2015 Keywords: Rhizobiaceae Pseudorhizobium Taxonomy Sea Spain a b s t r a c t Two novel Alphaproteobacteria strains, R1-200B4 T and R2-400B4, were isolated from the Mediterranean Sea off the coast of Alicante in Spain. The phylogenetic analysis of the 16S rRNA gene showed that they are related to members of Family Rhizobiaceae. The 16S rRNA gene sequence of strain R1-200B4 T presents 97.0% and 95.6% similarity with respect to the type strains of the type species from genera Neorhizobium and Rhizobium, Neorhizobium galegae HAMBI 540 T and Rhizobium leguminosarum USDA 2370 T , respec- tively. The remaining genera of family Rhizobiaceae showed similarities lower than 95%. The recA and atpD gene sequences of strain R1-200B4 T showed, respectively, 90% and 88.6% similarity with respect to N. galegae HAMBI 540 T and 87% and 86% with respect to R. leguminosarum USDA 2370 T . The calculated ANI values between the genomes of the strain R1-200B4 T and those of N. galegae HAMBI 540 T and R. leguminosarum 3841 are 75.9% and 74.0%, respectively. The major fatty acids are those from summed feature 8 (C 18:1 6c/C 18:1 7c) and the C 16:0 . Catalase and oxidase were positive. Nitrate reduction and aesculin hydrolysis were positive. Production of -galactosidase and urease was positive. The production of indol, arginine dehydrolase or gelatinase was negative. Growth was observed in presence of 7% NaCl. Therefore, based on the phylogenetic, chemotaxonomic and phenotypic data obtained in this study, we propose to classify the strains isolated in this study in a new genus named Pseudorhizobium gen. nov. and a new species named Pseudorhizobium pelagicum sp. nov. with the type strain R1-200B4 T (= LMG 28314 T = CECT 8629 T ). © 2015 Published by Elsevier GmbH. The Family Rhizobiaceae from alpha Proteobacteria currently encompasses eight genera, namely Rhizobium [9,32], Ensifer [6], Shinella [2], Ciceribacter [10], Neorhizobium [16], Agrobacterium, Allorhizobium and Pararhizobium [17]. Some of these genera are phylogenetically close with 16S rRNA gene similarity around 97%, as occurs in the case of genera Ciceribacter and Ensifer [10]. Similar values are also commonly found among genera of other fam- ilies from the order Rhizobiales, such as Phyllobacteriaceae and Bradyrhizobiaceae, which are phylogenetically related to family  Whole genome shotgun sequence: JOKI01000001. ∗ Corresponding author at: Departamento de Microbiología y Genética, Edificio Departamental de Biología, Universidad de Salamanca, Lab 209, Doctores de la Reina s/n, Salamanca 37007, Spain. Tel.: +34 923 294532; fax: +34 923 224876. E-mail address: evp@usal.es (E. Velázquez). Rhizobiaceae. Within Phyllobacteriaceae more than 97% similarity in the 16S rRNA gene sequences is found between Aminobacter and Mesorhizobium and between Aquamicrobium and Defluvibac- ter. Within the family Bradyrhizobiaceae similarity values even higher than 97% are found among the genera Oligrotropha, Afipia, Nitrobacter, Metalliresistens, Rhodopseudomonas, Tardiphaga, and Bradyrhizobium (see Fig. 1). Hence, 16S rRNA similarity values around 97% is the current limit for delineation of genera in several families from the order Rhizobiales. Members of the family Rhizobiaceae are commonly involved in plant-microbe interactions; however, some of them have been isolated from other sources, although there are no marine isolates within this family [18]. Therefore, the taxon described in this work represents the first marine member of family Rhizobiaceae. The genetic and phenotypic characteristics support its classifi- cation into a new genus and a new species for which the names http://dx.doi.org/10.1016/j.syapm.2015.05.003 0723-2020/© 2015 Published by Elsevier GmbH.