Thermaerobacter marianensis gen. nov., sp. nov., an aerobic extremely thermophilic marine bacterium from the 11000 m deep Mariana Trench

Abstract

A novel extremely thermophilic bacterium was isolated from the world's deepest sea-floor, the Mariana Trench Challenger Deep a t a depth of 10897 m. Cells were Gram-reaction variable, non-spore-forming and non-motile rods without flagella. Growth was observed between 50 and 80 "C (optimum: 74-76 "C; 90 min doubling time), pH 5 4 and 9.5 (optimum: pH 7.0-705) and 0 5 and 5 % sea salts (optimum: 2 % sea salts). The isolate was a strictly aerobic heterotroph capable of utilizing as sole energy and carbon source: yeast extract, peptone, cellulose, starch, chitin, casein, Casamino acids, a variety of sugars, carboxylic acids and amino acids. The G+C content of the genomic DNA was 72.5 mol%. Phylogenetic analysis based on 165 rRNA sequences placed this aerobic, high-G+C-content bacterium among the members of the Grampositive, low-G+C-content anaerobic thermophilic bacteria within the Bacillus-Clostridium subphylum. On the basis of the physiological and molecular properties of the new isolate, the name Thermaembacter marianensis gen. nov., sp. nov. (type strain 7p75aT = JCM 102463 is proposed.

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

“…MJNS medium consisted of (l 21 MJ synthetic sea water): 1 ml vitamin solution (Balch et al, 1979), 50 mg sodium selenite, 30 mg sodium tungstate, 1 mg resazurin, 10 mM NaNO 3 , 3 % (w/v) elemental sulfur, 20 g NaHCO 3 and 0?5 g Na 2 S.9H 2 O (Sako et al, 1996;Takai et al, 1999). To prepare the supplemented medium, sodium selenite, sodium tungstate, resazurin, yeast extract (1 g) and tryptone (1 g) were dissolved in 1 l MJ synthetic sea water and the pH of the medium was adjusted to around 7?0 with NaOH before autoclaving.…”

“…Each of the sample sections (approx. 10 g each) was suspended in 20 ml sterilized MJ synthetic sea water (Sako et al, 1996;Takai et al, 1999) containing 0?05 % (w/v) sodium sulfide in a 100-ml glass bottle (Schott Glaswerke) tightly sealed with a butyl rubber cap under a gas phase of 100 % N 2 (100 kPa). These suspended portions of the samples were inoculated (0?1 % volume of the medium) with MJNS medium (described below) supplemented with 0?1 % (w/v) yeast extract and 0?1 % (w/v) tryptone under a gas phase of 80 % H 2 and 20 % CO 2 (300 kPa).…”

Description of 'Synergistetes' phyl. nov. and emended description of the phylum 'Deferribacteres' and of the family Syntrophomonadaceae, phylum 'Firmicutes'

“…The members of the 'Synergistes' clade had a typical Gramnegative cell-wall structure with an outer membrane, as observed using electron microscopy (Allison et al, 1992;Baena et al, 1999Baena et al, , 2000Dahle & Birkeland, 2006;Magot et al, 1997;Menes & Muxi, 2002;Surkov et al, 2001;Zavarzina et al, 2000). In contrast, other members of Syntrophomonadaceae possessed a Gram-positive type cellwall structure without an outer membrane but with a thin peptidoglycan layer (Cayol et al, 1995;Gorlenko et al, 2004;Huang et al, 1998;Sokolova et al, 2002;Sekiguchi et al, 2000;Svetlitshnyi et al,1996;Takai et al, 1999). The thinness of this layer could explain the negative reaction to Gram stain observed for these bacteria.…”

“…Subsequently, bacteria from various environments such as a wastewater treatment lagoon (Menes & Muxi, 2002), activated sludge (Baena et al, 1999;Sekiguchi et al, 2000;Díaz et al, 2007), hot springs (Gorlenko et al, 2004;Sokolova et al, 2002), sulfur mats in a saline environment (Surkov et al, 2001) and a deep marine trench (Takai et al, 1999) were aggregated to the family Syntrophomonadaceae in the phylum 'Firmicutes'. The family contained 16 genera (Garrity et al, 2004), but most of them did not match the initial description of the family; in particular, syntrophic metabolism with hydrogenotrophic bacteria has only been observed for some of them (Svetlitshnyi et al, 1996;Wu et al, 2006a).…”

Sunxiuqinia faeciviva sp. nov., a facultatively anaerobic organoheterotroph of the Bacteroidetes isolated from deep subseafloor sediment

“…Strain JAM-BA0302 T grew at 15 u C on marine agar 2216 (MA; Difco) with the pH adjusted to pH 7.0 and was purified by more than five rounds of colony isolation at 15 u C using the same medium (Kobayashi et al, 2008). After purification, strain JAM-BA0302 T was routinely cultivated in MJYTG medium (pH 7.5) consisting of 2 g yeast extract, 2 g tryptone and 0.5 g glucose per litre of MJ synthetic seawater (Takai et al, 1999) or in marine broth 2216 (MB; pH 7.5).…”