Thermococcus hydrothermalis sp. nov., a New Hyperthermophilic Archaeon Isolated from a Deep-Sea Hydrothermal Vent

Abstract

An extremely thermophilic archaeon, strain AL662T, was isolated from a deep-sea hydrothermal vent located on the East Pacific Rise at a latitude of 21"N. This strain is a strictly anaerobic coccus, and its cells range from 0.8 to 2 pm in diameter. The optimum temperature, pH, and Sea Salt concentration for growth are 85"C, 6, and 20 to 40 g/liter, respectively. Strain AL662T grows preferentially on proteolysis products, on a mixture of 20 amino acids, and on maltose in the presence of elemental sulfur. The membrane lipids consist of di-and tetraether glycerol lipids. The DNA G+C content is 58 mol%. Sequencing of the 16s rRNA gene showed that strain AL662T belongs to the genus Thermococcus. On the basis of hybridization results, we propose that this strain should be placed in a new species, Thermococcus hydrothermalis.Since the discovery of hyperthermophilic archaea, strains belonging to the order Thermococcales have been isolated from both terrestrial and marine hot environments and described. Species belonging to the genus Thermococcus have been isolated from various deep-sea and shallow marine hydrothermal areas and described. All of the strains have quite similar physiological characteristics and can be divided into the following two groups on the basis of their G + C contents: (i) a group of strains with high G + C contents (50 to 58 mol%), including strains belonging to two species from shallow marine environments, Therrnococcus celer (34) and Thermococcus stetteri (20), and three species from deep-sea environments, Thermococcus profundus (14), "Thermococcus peptonophilus" (S), and Thermococcusfumicolans (7); and (ii) a group of strains with low G+C contents (38 to 47 mol%), including strains belonging to two species from deep-sea environments, "Thermococcus chitonophagus" (1 1) and "Thermococcus alcaliphilus" (13), and an organism from a shallow marine environment, "Thermococcus litoralis" (22). All of these species are able to use proteinaceous carbon substrates in the absence or presence of sulfur. Some of these strains are able to grow in the absence of elemental sulfur, but sulfur greatly enhances growth. In this paper, we describe a new hyperthermophilic heterotrophic archaeal species that was isolated from a deep-sea hydrothermal vent on the East Pacific Rise at a latitude of 21"N. This organism was selected on the basis of the results of a preliminary screening for alcohol dehydrogenase (ADH) activity in 71 hyperthermophilic heterotrophic strains that were isolated at 80 and 95°C from various deep-sea hydrothermal vent areas (15). MATERIALS AND METHODSReference strains. Thermococcus celer DSM 2476', "Thermococcus litoralis" DSM 5474T, Thermucoccus stetteri DSM 5262.", Sulfolobus acidocaldarius DSM 639", and Thermotugu maritima DSM 310gT were obtained from the Deutsche Sammlung von Mikroorganismen, Braunschweig-Stockeim, Germany. Other strains were directly obtained from researchers. DT5432T was provided by Tetsuo Kobayashi (RIKEN, Wako, Japan). Thermococcus fumicolans CIP104680~" was isolated in our...

Persephonella marina gen. nov., sp. nov. and Persephonella guaymasensis sp. nov., two novel, thermophilic, hydrogen-oxidizing microaerophiles from deep-sea hydrothermal vents.

“…Furthermore, fluorescent 16S rDNA probes specific for the Aquificales and a novel sulfur-reducing lineage represented by Desulfurobacterium (Harmsen et al, Deep-sea microaerophilic thermophiles 1997) showed that up to 40 % of the bacterial community was accounted for by these lineages in a hydrothermal chimney from the Mid-Atlantic Ridge. It is therefore possible that, like their terrestrial relatives, the chemolithoautotrophic Aquificales are important members of high-temperature, deep-sea hydrothermal vent niches, providing organic carbon for deep-sea vent heterotrophs such as the Thermococcales (Canganella et al, 1998 ;Godfroy et al, 1996Godfroy et al, , 1997 and the Thermotogales (Takai & Horikoshi, 2000).…”

Deferribacter desulfuricans sp. nov., a novel sulfur-, nitrate- and arsenate-reducing thermophile isolated from a deep-sea hydrothermal vent

“…Members of the orders Thermococcales and Thermotogales are isolated most frequently and are widely distributed in global deep-sea hydrothermal systems (Pledger & Baross, 1989;1991;Stetter et al, 1990Stetter et al, , 1993Gonzalez et al, 1995Gonzalez et al, , 1998Godfroy et al, 1996Godfroy et al, , 1997Antoine et al, 1997;Takai & Fujiwara, 2002). Recently, several investigations using a combination of culture-dependent and -independent analyses have revealed that these sulfur-reducing, heterotrophic thermophiles dominate microbial populations in deep-sea hydrothermal vent chimney structures, specifically on the surfaces of the chimney structures (Harmsen et al, 1997;Takai et al, 2001).…”

Identification of Anaerobic Thermophilic Thermococcus Dominant in Enrichment Cultures from a Hydrothermal Vent Sediment of Tofua Arc

“…이것은 열수구에 존재하는 고세균 중 가장 우점하는 종류가 Thermococcus이기 때문으로 추정된다 (Takai and Nakamura, 2011). Thermococcus 속에 속하는 종들의 생장 온도는 약 55-110℃의 범위에서 생장이 가능하고 (Stetter, 1996;Godfroy et al, 1997;Kuwabara et al, 2005), 최적의 온도는 약 80-90℃이다 (Zillig et al, 1983;Kobayashi et al, 1994;González et al, 1995;Dirmeier et al, 1998) (Arab et al, 2000).…”