title: Genome and metabolic network of "Candidatus Phaeomarinobacter ectocarpi" Ec32, a new candidate genus of Alphaproteobacteria frequently associated with brown algae.
abstract: Rhizobiales and related orders of Alphaproteobacteria comprise several genera of nodule-inducing symbiotic bacteria associated with plant roots. Here we describe the genome and the metabolic network of "Candidatus Phaeomarinobacter ectocarpi" Ec32, a member of a new candidate genus closely related to Rhizobiales and found in association with cultures of the filamentous brown algal model Ectocarpus. The "Ca. P. ectocarpi" genome encodes numerous metabolic pathways that may be relevant for this bacterium to interact with algae. Notably, it possesses a large set of glycoside hydrolases and transporters, which may serve to process and assimilate algal metabolites. It also harbors several proteins likely to be involved in the synthesis of algal hormones such as auxins and cytokinins, as well as the vitamins pyridoxine, biotin, and thiamine. As of today, "Ca. P. ectocarpi" has not been successfully cultured, and identical 16S rDNA sequences have been found exclusively associated with Ectocarpus. However, related sequences (≥97% identity) have also been detected free-living and in a Fucus vesiculosus microbiome barcoding project, indicating that the candidate genus "Phaeomarinobacter" may comprise several species, which may colonize different niches.
authors.affiliation: Sorbonne Universités, UPMC Univ. Paris 06, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff Roscoff, France ; CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff Roscoff, France.
authors.forename: Simon M
authors.initials: SM
authors.lastname: Dittami
authors.affiliation: Sorbonne Universités, UPMC Univ. Paris 06, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff Roscoff, France ; CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff Roscoff, France.
authors.forename: Tristan
authors.initials: T
authors.lastname: Barbeyron
authors.affiliation: Sorbonne Universités, UPMC Univ. Paris 06, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff Roscoff, France ; CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff Roscoff, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Boyen
authors.affiliation: CNRS, IRISA UMR 6074 Rennes, France ; IRISA UMR 6074, Université de Rennes 1 Rennes, France ; INRIA, Centre Rennes-Bretagne-Atlantique, Projet Dyliss Rennes, France.
authors.forename: Jeanne
authors.initials: J
authors.lastname: Cambefort
authors.affiliation: CNRS, IRISA UMR 6074 Rennes, France ; IRISA UMR 6074, Université de Rennes 1 Rennes, France ; INRIA, Centre Rennes-Bretagne-Atlantique, Projet Dyliss Rennes, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Collet
authors.affiliation: Sorbonne Universités, UPMC Univ. Paris 06, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff Roscoff, France ; CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff Roscoff, France.
authors.forename: Ludovic
authors.initials: L
authors.lastname: Delage
authors.affiliation: Sorbonne Universités, UPMC Univ. Paris 06, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff Roscoff, France ; CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff Roscoff, France.
authors.forename: Angélique
authors.initials: A
authors.lastname: Gobet
authors.affiliation: Sorbonne Universités, UPMC Univ. Paris 06, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff Roscoff, France ; CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff Roscoff, France.
authors.forename: Agnès
authors.initials: A
authors.lastname: Groisillier
authors.affiliation: Sorbonne Universités, UPMC Univ. Paris 06, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff Roscoff, France ; CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff Roscoff, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Leblanc
authors.affiliation: Sorbonne Universités, UPMC Univ. Paris 06, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff Roscoff, France ; CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff Roscoff, France.
authors.forename: Gurvan
authors.initials: G
authors.lastname: Michel
authors.affiliation: Sorbonne Universités, UPMC Univ. Paris 06, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff Roscoff, France ; CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff Roscoff, France.
authors.forename: Delphine
authors.initials: D
authors.lastname: Scornet
authors.affiliation: CNRS, IRISA UMR 6074 Rennes, France ; IRISA UMR 6074, Université de Rennes 1 Rennes, France ; INRIA, Centre Rennes-Bretagne-Atlantique, Projet Dyliss Rennes, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Siegel
authors.affiliation: Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile Santiago, Chile.
authors.forename: Javier E
authors.initials: JE
authors.lastname: Tapia
authors.affiliation: Sorbonne Universités, UPMC Univ. Paris 06, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff Roscoff, France ; CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff Roscoff, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Tonon
keywords: algal-bacterial interactions; genome sequencing; holobiont; metabolic network; phytohormones; symbiosis; transporters; vitamins