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International audience; The human gut is composed of a large diversity of microorganisms, which have been poorly described. Here, using culturomics, a new concept based on the variation in culture conditions and MALDI-TOF MS identification, we proceed to explore the microbial diversity of the complex ecosystem of the human gut. Using this approach, we isolated strain AT8(T) (=CSUR P2118 = DSM 101782) from stool specimens collected from a 51-year-old obese French woman. Strain AT8(T) is a strictly anaerobic, nonmotile, nonspore-forming gram-positive coccus that do not exhibit catalase and oxidase activities. 16S rDNA-based identification of strain AT8(T) demonstrated 92% gene sequence similarity with Eggerthella lenta DSM 2243, the phylogenetically closed validly named type species. Here, we present a set of features for the strain AT8(T) and the description of its complete genome sequence and annotation. The 2,091,845bp long genome has a G+C content of 63.46% and encodes1,849 predicted genes; 1,781 were protein-coding genes, and 68 were RNAs. On the basis of the characteristics reported here, we propose the creation of a new bacterial genus Hugonella gen. nov., belonging to the Eggerthellaceae family and including Hugonella massiliensis gen. nov., sp. nov., strain AT8(T) as the type strain.

International audience; Phosphate limitation is an important environmental stress that affects the metabolism of various organisms and, in particular, can trigger the virulence of numerous bacterial pathogens. Clostridium perfringens, a human pathogen, is one of the most common causes of enteritis necroticans, gas gangrene and food poisoning. Here, we focused on the high affinity phosphate-binding protein (PBP-1) of an ABC-type transporter, responsible for cellular phosphate uptake. We report the crystal structure (1.65 A ˚ resolution) of the protein in complex with phosphate. Interestingly, PBP-1 does not form the short, low-barrier hydrogen bond with phosphate that is typical of previously characterized phosphate-binding proteins, but rather a canonical hydrogen bond. In its unique binding configuration, PBP-1 forms an unusually high number of hydrogen bonds (14) with the phosphate anion. Discrimination experiments reveal that PBP-1 is the least selective PBP characterised so far and is able to discriminate phosphate from its close competing anion, arsenate, by ,150-fold. P hosphorus is essential for living organisms because it is involved in the composition of critical biomolecules (e.g., nucleic acids) and in key biological processes 1. Although phosphorus is relatively abundant on our planet, it is mostly trapped in rocks 2. Therefore, the bioavailability of phosphorus is limited, and living organisms have had to develop efficient mechanisms to extract phosphate from the environment 3. In prokaryotes, two main systems have been identified so far: (i) the Phosphate inorganic transport (Pit) and (ii) the Phosphate specific transport (Pst) systems. The Pit system is a single transmembrane component 4,5 , that is fueled by the proton-motive force and transports a divalent metal cation complexed with a phosphate anion 6. Pst, the predominant phosphate transporter 7 , is a classical ABC-transporter, composed of 5 proteins: 2 membrane permeases (PstA and PstC), 2 ATPases (PstB) and the high-affinity phosphate binding protein PstS (or phosphate-binding protein, PBP) 8. The Pst system is a high-affinity, high-specificity transporter that enables the extraction of phosphate from the environment 9,10