Caloranaerobacter azorensis gen. nov., sp. nov., an anaerobic thermophilic bacterium isolated from a deep-sea hydrothermal vent A thermophilic, anaerobic, chemo-organotrophic bacterium, designated MV1087 T , was isolated from a deep-sea hydrothermal chimney sample collected from the Mid-Atlantic Ridge. The cells were straight, motile and stained Gram-negative. Growth was observed from 45 to 65 SC, with an optimum around 65 SC. No growth was observed at 40 or 70 SC. Growth was observed from pH 55 to 90 and the optimum pH was around 7. The salinity range for growth was 10-100 g sea salt l N1 (corresponding to 65-65 g NaCl l N1 ) with an optimum at 30 g sea salt l N1 (20 g NaCl l N1 ). Strain MV1087 T was heterotrophic, able to ferment proteinaceous substrates, such as brain/heart infusion and gluten, and carbohydrates, such as glucose, xylan and starch. The DNA GMC content was 27 mol %. Phylogenetic analyses using 16S rDNA sequences indicated that strain MV1087 T belonged to cluster XII of the Clostridium subphylum. Due to its phenotypic and genotypic characteristics, isolate MV1087T is proposed as a novel species of a new genus, Caloranaerobacter azorensis gen. nov., sp. nov. The type strain is MV1087 T (l CNCM I-2543 T l DSM 13643 T ).

Aims: The objective of the present work was to describe an aerobic, mesophilic and heterotrophic marine bacterium, designated HYD657, able to produce an exopolysaccharide (EPS). It was isolated from a East Pacific Rise deep‐sea hydrothermal vent polychaete annelid. 
Methods and Results: This micro‐organism, on the basis of the phenotypical features and genotypic investigations, can be clearly assigned to the Alteromonas macleodii species and the name A. macleodii subsp. fijiensis biovar deepsane is proposed. Optimal growth occurs between 30 and 35°C, at pH between 6˙5 and 7˙5 and at ionic strengths between 20 and 40 g l−1 NaCl. The G + C content of DNA was 46˙5%. This bacterium excreted, under laboratory conditions, an EPS consisting of glucose, galactose, rhamnose, fucose and mannose as neutral sugars along with glucuronic and galacturonic acids and a diacidic hexose identified as a 3‐0‐(1 carboxyethyl)‐d‐glucuronic acid. Its average molecular mass was 1˙6 × 106 Da. 
Conclusions: The bacterium HYD657, for which the name A. macleodii subsp. fijiensis biovar deepsane is proposed, produces an unusual EPS in specific medium. 
Significance and Impact of the Study: Due to its interesting biological activities, applications have been found in cosmetics. Its probable contribution to the filamentous microbial mat in the Alvinella pompejana microenvironment can be also mentioned.