Thermococcus henrietii sp. nov., a novel extreme thermophilic and piezophilic sulfur-reducing archaeon isolated from a deep-sea hydrothermal chimney

Abstract

A novel extreme thermophilic and piezophilic chemoorganoheterotrophic archaeon, strain EXT12cT, was isolated from a hydrothermal chimney sample collected at a depth of 2496 m at the East Pacific Rise 9° N. Cells were strictly anaerobic, motile cocci. The strain grew at NaCl concentrations ranging from 1 to 5 % (w/v; optimum, 2.0%), from pH 6.0 to 7.5 (optimum, pH 6.5–7.0), at temperatures between 60 and 95 °C (optimum, 80–85 °C), and at pressures from 0.1 to at least 50 MPa (optimum, 30 MPa). Strain EXT12cT grew chemoorganoheterotrophically on complex proteinaceous substrates. Its growth was highly stimulated by the presence of elemental sulphur or l-cystine, which were reduced to hydrogen sulfide. The DNA G+C content was 54.58 mol%. Phylogenetic analyses based on 16S rRNA gene sequences and concatenated ribosomal protein sequences showed that strain EXT12cT falls into the genus Thermococcus and is most closely related to Thermococcus nautili strain 30-1T. Overall genome relatedness index analyses (average nucleotide identity scores and in silico DNA–DNA hybridizations) showed a sufficient genomic distance between the new genome and the ones of the Thermococcus type strains for the delineation of a new species. On the basis of genotypic and phenotypic data, strain EXT12cT is considered to represent a novel species, for which the name Thermococcus henrietii sp. nov. is proposed, with the type strain EXT12cT (=UBOCC M-2417T=DSM 111004T).

Depth wide distribution and metabolic potential of chemolithoautotrophic microorganisms reactivated from deep continental granitic crust underneath the Deccan Traps at Koyna, India

“…Samples from different subsurface settings have been previously used to investigate the abundance, nature, and substrate specific response of deep dwelling organisms via several cultivation-based methods and enrichment studies ( Kotelnikova and Pedersen, 1998 ; Hallbeck and Pedersen, 2008 , 2012 ; Fichtel et al, 2015 ; Rajala et al, 2015 ; Russell et al, 2016 ; Purkamo et al, 2017 , 2020 ; Rajala and Bomberg, 2017 ; Leandro et al, 2018 ; Imachi et al, 2019 ; Sanz et al, 2021 ; Nuppunen-Puputti et al, 2022 ). The outcome of these studies, resulted in the enrichment of microorganisms mostly belonging to bacterial phyla Proteobacteria, Firmicutes, Actinobacteria, Chloroflexi and Bacteroidetes ( Rastogi et al, 2009 , 2013 ; Fichtel et al, 2012 ; Fortunato and Huber, 2016 ; Rajala and Bomberg, 2017 ; Leandro et al, 2018 ) and archaeal members including Euryarchaeota, Thaumarchaeota and Crenarchaeota ( Zeng et al, 2009 ; Nuppunen-Puputti et al, 2018 ; Imachi et al, 2020 ; Alain et al, 2021 ; Courtine et al, 2021 ; Li et al, 2021 ). “In the last few years, metagenomic investigations of terrestrial subsurface microbiome” (crustal/vent, faults or fractures fluids, aquifer samples have shown considerable species diversity with potential for assimilation of C and inorganic resources for energy metabolism ( Nyyssönen et al, 2014 ; Purkamo et al, 2015 ; Hubalek et al, 2016 ; Lau et al, 2016 ; Magnabosco et al, 2016 ; Wu et al, 2016 ; Momper et al, 2017 ; Bell et al, 2020 ; Purkamo et al, 2020 ).…”

Thermococcus argininiproducens sp. nov., an arginine biosynthesis archaeal species isolated from the Central Indian Ocean ridge

“…Among hyperthermophilic archaea belonging to the order Thermococcales , many species of the genus Thermococcus have been isolated from various deep-sea hydrothermal vents. Recently, Thermococcus indicus IOH1 T [8], Thermococcus aciditolerans SY113 T [9], Thermococcus henrietii EXT12c T [10] and Thermococcus camini Iri35c T [11] were isolated from sediment collected from the Central Indian Ocean Ridge (Onnuri vent field), a deep-sea hydrothermal vent chimney on the Southwest Indian Ridge, a hydrothermal chimney on the East Pacific Rise, and a hydrothermal chimney rock sample from the Mid-Atlantic Ridge (Rainbow vent field), respectively.…”

Characterizing the Piezosphere: The Effects of Decompression on Microbial Growth Dynamics

“…Despite this, pressure seems to be one of the least explored parameters for microbial growth, as relatively few microorganisms from these deep environments have been isolated and/or grown under in situ pressures. To date, fewer than 100 species have been reported to be piezotolerant or piezophilic ( Picard and Daniel, 2013 ; Jebbar et al, 2015 ; Cario et al, 2019 ; Oliver et al, 2020 ; Alain et al, 2021 ; Courtine et al, 2021 ; Li et al, 2021 ; Yu et al, 2021 ; Zhang et al, 2022 ), and few obligate piezophiles have been identified ( Bartlett, 2002 ; Zeng et al, 2009 ). Therefore, our knowledge of active microbial species, their physiological and metabolic potential, and community diversity in these deep environments is limited.…”