Pyrococcus kukulkanii sp. nov., a hyperthermophilic, piezophilic archaeon isolated from a deep-sea hydrothermal vent

Abstract

A novel hyperthermophilic, piezophilic, anaerobic archaeon, designated NCB100 T , was isolated from a hydrothermal vent flange fragment collected in the Guaymas basin at the hydrothermal vent site named 'Rebecca's Roost' at a depth of 1997 m. Enrichment and isolation were performed at 100 C under atmospheric pressure. Cells of strain NCB100 T were highly motile, irregular cocci with a diameter of~1 µm. Growth was recorded at temperatures between 70 and 112 C (optimum 105 C) and hydrostatic pressures of 0.1-80 MPa (optimum 40-50 MPa). Growth was observed at pH 3.5-8.5 (optimum pH 7) and with 1.5-7 % NaCl (optimum at 2.5-3 %). Strain NCB100 T was a strictly anaerobic chemo-organoheterotroph and grew on complex proteinaceous substrates such as yeast extract, peptone and tryptone, as well as on glycogen and starch. Elemental sulfur was required for growth and was reduced to hydrogen sulfide. The fermentation products from complex proteinaceous substrates were CO 2 and H 2 . The G+C content of the genomic DNA was 41.3 %. Phylogenetic analysis of the 16S rRNA gene sequence revealed that strain NCB100 T belongs to the genus Pyrococcus, showing 99 % similarity with the other described species of the genus Pyrococcus. On the basis of physiological characteristics, DNA G+C content, similarity level between ribosomal proteins and an average nucleotide identity value of 79 %, strain NCB100 T represents a novel species for which the name Pyrococcus kukulkanii sp. nov. is proposed. The type strain is NCB100 T (=DSM 101590 T =Souchoth eque de Bretagne BG1337 T ). †Present address:

Microorganisms from deep-sea hydrothermal vents

“…Archaea of the order Thermococcales, distributed in three genera (i.e., Thermococcus, Pyrococcus, and Palaeococcus), have versatile physiologies to thrive in active hydrothermal vents, sediments, and even below the surface under hydrothermal vents (Teske et al 2009;Zeng et al 2013 (Birrien et al 2011;Zeng et al 2009), Pyrococcus kukulkanii (Callac et al 2016), Palaeococcus ferrophilus , and Palaeococcus pacificus (Zeng et al 2013). All Thermococcales species can ferment a variety of organic compounds, such as peptides, amino acids, organic acids, and diverse sugars, with S 0 as the electron acceptor.…”

Functionalized Membrane Domains: An Ancestral Feature of Archaea?

“…However, as aforementioned, extraction methods often lead to biased lipid compositions which may specifically overlook tetraether lipids. For instance, only diethers were identified during the first descriptions of T. barophilus, T. celer, and P. kukulkanii (De Rosa et al, 1987;Marteinsson et al, 1999;Callac et al, 2016). Thus, using the same parsimony approach we applied to estimate the diether synthesis ability of the few uncertain Proteoarchaeota species, we considered that if one or more species of a genus possesses the ability to synthesize tetraethers lipids, then all members of the genus share this ability.…”

Novel Intact Polar and Core Lipid Compositions in the Pyrococcus Model Species, P. furiosus and P. yayanosii, Reveal the Largest Lipid Diversity Amongst Thermococcales

“…Additionally, the core lipid compositions of P. furiosus and P. woesei differ greatly from that of other Pyrococcus members, such as P. abyssi, which synthesizes 15% of DGD and 85% of GDGT, including ca. 9% with two cyclopentane rings [23], P. horikoshii, which mostly produces tetraether lipids (>90%) with more than 15% in the GMGT monoalkyl form [24][25][26], and P. kukulkanii, which seemingly produces only diether lipids [27].…”