Clostridium caminithermale sp. nov., a slightly halophilic and moderately thermophilic bacterium isolated from an Atlantic deep-sea hydrothermal chimney

Abstract

A strictly anaerobic, slightly halophilic and moderately thermophilic, sporulating rod designated strain DVird3 T was isolated from deep-sea hydrothermal vent samples collected at a depth of approximately 800 m on the Atlantic Ocean Ridge. Strain DVird3 T possessed a few laterally inserted flagella, had a DNA G+C content of 33?1 mol% and grew optimally at pH 6?6 and at 45˚C. Growth was observed at temperatures between 20 and 58˚C and at pH values between 5?8 and 8?2. The optimum NaCl concentration for growth was 3 % sea salt (30 g l "1 ); no growth was observed in the presence of 15 or 60 g sea salt l "1 . Strain DVird3 T is heterotrophic and utilizes some sugars and various single amino acids. Acetate was the main fatty acid detected from carbohydrate fermentation, together with H 2 and CO 2 . Gelatin was used as an energy source. It performed the Stickland reaction. Phylogenetically, strain DVird3 T branched with members of cluster XI of the order Clostridiales, with Clostridium halophilum as its closest relative (similarity of 94?6 %). On the basis of its phenotypic, genotypic and phylogenetic characteristics, strain DVird3 T (=DSM 15212 T =CIP 107654 T ) is proposed as the type strain of a novel species of the genus Clostridium, Clostridium caminithermale sp. nov.Deep-sea hydrothermal vents are inhabited by a wide range of microbial communities that comprise free-living microorganisms as well as micro-organisms living in association with invertebrates (Jeanthon, 2000). Among these freeliving micro-organisms are bacteria belonging to the e-subclass of the Proteobacteria, and the significance of their ecological role has been identified, mainly in molecular surveys (Haddad et al., 1995;Jeanthon, 2000;Reysenbach et al., 2000b;Corre et al., 2001). The recent isolation, from deep-sea hydrothermal vents, of moderately thermophilic and thermophilic members of the e-subclass of the Proteobacteria has demonstrated the ability of these microorganisms to grow autotrophically using elemental sulfur as a terminal electron acceptor (Campbell et al., 2001;Alain et al., 2002a). This trait of sulfur reduction has also been found to be a common physiological feature of the wellstudied, anaerobic, chemoautotrophic, thermophilic and hyperthermophilic micro-organisms (domain Archaea) isolated from these peculiar deep marine environments (Jeanthon, 2000). Besides chemoautotrophy and mixotrophy, chemoheterotrophy has also been recognized as a significant type of metabolism within the deep-sea hydrothermal vent anaerobic microbial community (Jeanthon, 2000). Among such trophic microbial groups inhabiting deep environments, little attention has been paid to anaerobic mesophiles and moderate thermophiles in comparison with thermophilic and hyperthermophilic micro-organisms from both domains (Bacteria and Archaea). Therefore, most microbiological studies performed so far have underlined the fact that thermophilic and hyperthermophilic archaea thrive in the hottest part of the ecosystem, with only a few thermophilic anaerobic members o...

Microbial Diversity in the Deep Marine Sediments from the Qiongdongnan Basin in South China Sea

“…C. caminithermale is strictly anaerobic and cannot use elemental sulfur, sulfate, thiosulfate, sulfite, nitrate or nitrite as electron acceptors (Brisbarre et al 2003).…”

Phylogenomic analysis of the family Peptostreptococcaceae (Clostridium cluster XI) and proposal for reclassification of Clostridium litorale (Fendrich et al. 1991) and Eubacterium acidaminophilum (Zindel et al. 1989) as Peptoclostridium litorale gen. nov. comb. nov. and Peptoclostridium acidaminophilum comb. nov.

“…DSM 2634=ATCC 13726). Subsequent analyses of 16S rRNA gene sequences showed that members of three proposed genera (listed as genera 6, 7 and 8 in Collins et al , 1994), namely ‘ C. aminobutyricum’ , Clostridium felsineum , Clostridium formicaceticum , and Clostridium halophilum , along with the more recently described Clostridium caminithermale , form a relatively compact separate group that also includes Clostridium aceticum and Anaerovirgula multivorans (Brisbarre et al , 2003; Chen et al , 2006; Pikuta et al , 2006; Gerritsen et al , 2014; Poehlein et al , 2015; Lawson et al , 2016). In the 2009 edition of Bergey’s, these species were assigned to Clostridiaceae 2, a sister group to Peptostreptococcaceae (Ludwig et al , 2009b), and are listed the same way in the SILVA database (Yilmaz et al , 2014).…”

Exiguobacterium profundum sp. nov., a moderately thermophilic, lactic acid-producing bacterium isolated from a deep-sea hydrothermal vent

“…Relatively few studies have investigated mesophiles and moderate thermophiles among the heterotrophic anaerobic microbial groups thriving in deep-sea environments (Campbell et al, 2001;Brisbarre et al, 2003) compared with thermophiles and hyperthermophiles belonging to the Bacteria and Archaea (Baross & Deming, 1995;Jeanthon et al, 1998;L'Haridon et al, 1998;Reysenbach et al, 2000a, b;Wery et al, 2001;Alain et al, 2002a, b;Götz et al, 2002). Here we report on the isolation from a deep-sea hydrothermal vent on the 13 u N East Pacific Rise of a novel, moderately thermophilic, anaerobic, homolactic fermentative bacterium (strain 10C T ) belonging to the genus Exiguobacterium, order Bacillales, family Bacillaceae.…”