Alteromonas infernus sp. nov., a new polysaccharide-producing bacterium isolated from a deep-sea hydrothermal vent

A deep-sea, aerobic, mesophilic and heterotrophic new bacterium was isolated from a sample of fluid collected among a dense population of Riftia pachyptila , in the vicinity of an active hydrothermal vent of the Southern depression of the Guaymas basin (Gulf of California). On the basis of phenotypic and phylogenetic analyses and DNA/DNA relatedness, the strain GY785 was recognized as a new species of the genus Alteromonas and the name of Alteromonas infernus is proposed. During the stationary phase in batch cultures in the presence of glucose, this bacterium secreted two unusual polysaccharides. The water-soluble exopolysaccharide-1 produced xrcontained glucose, galactose, galacturonic and glucuronic acids as monosaccharides. The gel-forming exopolysaccharide-2 was separated from the bacterial cells by dialysis against distilled water and partially characterized.     

Halomonas profundus sp. nov., a new PHA-producing bacterium isolated from a deep-sea hydrothermal vent shrimp

Aims:  The objective of the present work was to describe a new deep-sea, aerobic, mesophilic and heterotrophic bacterium, referenced as strain AT1214, able to produce polyhydroxyalkanoates (PHAs) under laboratory conditions. This bacterium was isolated from a shrimp collected nearby a hydrothermal vent located on the Mid-Atlantic Ridge. Methods and Results:  This micro-organism, on the basis of the phenotypical features and genotypic investigations, can be clearly assigned to the Halomonas genus and the name of Halomonas profundus is proposed. Optimal growth occurred between 32 and 37°C at a pH between 8 and 9 and at ionic strength between 20 and 30 g l⁻¹ of sea salts. The G + C content of DNA was 58·6%. This bacterium produced PHAs of poly(3-hydroxybutyrate) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) from different carbon sources. Conclusions:  The bacterium H. profundus produces PHA of 3HB and 3HV monomers from different carbon sources. Significance and Impact of the Study:  PHAs share physical and material properties that suggest them for application in various areas, and are considered as an alternative to nonbiodegradable plastics produced from fossil oils. In this study, we describe a new bacteria isolated from a deep-sea hydrothermal vent with the capability to produce polyesters of biotechnological interest.     

Eptatretus strickrotti n. sp. (Myxinidae): first hagfish captured from a hydrothermal vent

A single hagfish (Myxinidae, Eptatretus) specimen was recently captured at a hydrothermal vent site on the East Pacific Rise (38 degrees S). This is the first capture of a member of the jawless fishes (agnathans) from a hydrothermal vent site. The specimen differs from all congeners by the very slender body (depth 2.9% of total length), the paired and median ventral nasal sinus papillae, and the presence of 10 afferent branchial arteries on the medial ventral aorta. It is further unique because of a combination of the following features: slime pore counts; paired dorsal nasal sinus papillae; 12 gill pouches and gill apertures; posterior left side of body widely separated from pharyngocutaneous duct; 3/2 multicusp configuration; ventral aorta bifurcated anteriorly between 2nd and 3rd gill pouches (counted from the snout toward the heart); and pink coloration. The specimen is here described as a new species named Eptatretus strickrotti. Molecular 16S rRNA data places this new species as the basal-most species of Eptatretus, providing important new insight to the evolution of hagfishes as a whole.     

Pyrococcus horikoshii sp. nov., a hyperthermophilic archaeon isolated from a hydrothermal vent at the Okinawa Trough

A hyperthermophilic, anaerobic archaeon was isolated from hydrothermal fluid samples obtained at the Okinawa Trough vents in the NE Pacific Ocean, at a depth of 1395 m. The strain is obligately heterotrophic, and utilizes complex proteinaceous media (peptone, tryptone, or yeast extract), or a 21-amino-acid mixture supplemented with vitamins, as growth substrates. Sulfur greatly enhances growth. The cells are irregular cocci with a tuft of flagella, growing optimally at 98°C (maximum growth temperature 102°C), but capable of prolonged survival at 105°C. Optimum growth was at pH 7 (range 5–8) and NaCl concentration 2.4% (range 1%–5%). Tryptophan was required for growth, in contrast to the closely related strains Pyrococcus furiosus and P. abyssi. Thin sections of the cell, viewed by transmission electron microscopy, revealed a periplasmic space similar in appearance to the envelope of P. furiosus. The predominant cell membrane component was tetraether lipid, with minor amounts of diether lipids. Treatment of the cells by mild osmotic shock released an extract that contained a Zn²⁺-dependent alkaline phosphatase. Phylogenetic analysis of the sequences encoding 16S rRNA and glutamate dehydrogenase places the isolate with certainty within the genus Pyrococcus although there is relatively low DNA–DNA hybridization (<63%) with described species of this genus. Based on the reported results, we propose a new species, to be named Pyrococcus horikoshii sp. nov. Received: December 10, 1997 / Accepted: February 4, 1998     

Complete genome sequence of Thermococcus sp. strain 4557, a hyperthermophilic archaeon isolated from a deep-sea hydrothermal vent area

Thermococcus sp. strain 4557 is a hyperthermophilic anaerobic archaeon isolated from the deep-sea hydrothermal vent Guaymas Basin site in the Gulf of California at a depth of 2,000 m. Here, we present the complete genome sequence of Thermococcus sp. 4557, which consists of a single circular chromosome of 2,011,320 bp with a G+C content of 56.08%.     

Complete genome sequence of hyperthermophilic Pyrococcus sp. strain NA2, isolated from a deep-sea hydrothermal vent area

Pyrococcus sp. strain NA2, isolated from a deep-sea hydrothermal vent sample, is a novel marine hyperthermophilic archaeon that grows optimally at 93 °C. The complete genome sequence of the strain contains all the genes for the tricarboxylic acid cycle except for succinate dehydrogenase/fumarate reductase, but the genome does not encode proteins involved in polysaccharide utilization.     

A new species of Ingolfiellidae (Peracarida, Amphipoda, Crustacea) from the Azores, Portugal

A new species of Ingolfiellid Amphipod Ingolfiella azorensis n. sp. is described from samples collected in a benthic survey off the Azores archipelago, Portugal. The new species is characterized by the lack of ocular lobes, a four-toothed dactylus on the first and second gnathopods, and having dissimilar claws on the third to seventh pereiopods. Individuals were obtained from shallow subtidal samples of sand. The new findings bring the number of Ingolfiellidae from Macaronesia up to six, equalling almost 20 % of the world’s known species, suggesting this area as a potential evolutionary centre for Ingolfiellidae.     

Thermococcus siculi sp. nov., a novel hyperthermophilic archaeon isolated from a deep-sea hydrothermal vent at the Mid-Okinawa Trough

A novel coccoid-shaped, hyperthermophilic, anaerobic archaeon, strain RG-20, was isolated from a deep-sea hydrothermal vent fluid sample taken at 1394-m depth at the Mid-Okinawa Trough (27°32.7′N, 126°58.5′E). Cells of this isolate occur singly or in pairs and are about 0.8 to 2 μm in diameter. Growth was observed at temperatures between 50° and 93°C, with an optimum at 85°C. The pH range for growth is 5.0–9.0, with an optimum around 7.0. Strain RG-20 requires 1%–4% of NaCl for growth, and cell lysis occurs at concentrations below 1%. The newly isolated strain grows preferentially in the presence of elemental sulfur on proteinaceous substrates such as yeast extract, peptone, or tryptone, and no growth was observed on carbohydrates, carboxylic acids, alcohols, or lipids. This microorganism is resistant to streptomycin, chloramphenicol, ampicillin, and kanamycin at concentrations up to 150 μg/ml, but is susceptible to rifampicin. Analysis of the hydrolyzed core lipids by thin-layer chromatography (TLC) revealed the presence of archaeol and caldarchaeol. The mol% G+C content of the DNA is 55.8. Partial sequencing of the 16S rDNA indicates that strain RG-20 belongs to the genus Thermococcus. Considering these data and on the basis of the results from DNA-DNA hybridization studies, we propose that this strain should be classified as a new species named Thermococcus siculi (si′cu.li. L. gen. n. siculi, of the deep-sea [siculum, deep-sea in literature of Ovid], referring to the location of the sample site, a deep-sea hydrothermal vent). The type strain is isolate RG-20 (DSM No. 12349). Received: May 11, 1998 / Accepted: July 24, 1998     

Thermosipho japonicus sp. nov., an extremely thermophilic bacterium isolated from a deep-sea hydrothermal vent in Japan

A novel barophilic, extremely thermophilic bacterium was isolated from a deep-sea hydrothermal vent chimney at the Iheya Basin, in the Okinawa area, Japan. The cells were found to be rod shaped and surrounded by a sheath-like outer structure; the organism did not possess flagella and was not motile. Growth was observed between 45° and 80°C (optimum, 72°C, 45 min doubling time), pH 5.3 and 9.3 (optimum, pH 7.2–7.6), 6.6 and 79 g/l sea salts (optimum, 40 g/l), and 0.1 and 60 MPa (optimum, 20 MPa). Strain IHB1 was found to be a strictly anaerobic chemoorganotroph capable of utilizing yeast extract and proteinaceous substrates such as peptone and tryptone. Elemental sulfur or thiosulfate acted as electron acceptors improving growth. The isolate was able to utilize casein as a sole carbon and energy source in the presence of thiosulfate. The G + C content of the genomic DNA was 31.4 mol%. Phylogenetic analysis based on 16S rDNA sequences and DNA–DNA hybridization analysis indicated that the isolate is closely related to Thermosipho africanus; however, it represents a species distinct from the previously described members of the genus Thermosipho. On the basis of the physiological and molecular properties, we propose that the new isolate represents a new species, which we name Thermosipho japonicus sp. nov. (type strain: IHB1; JCM10495). Received: May 26, 1999 / Accepted: August 7, 1999     

Formation and morphology of epidermal sclerites from a deep-sea hydrothermal vent solenogaster (Helicoradomenia sp., Solenogastres, Mollusca)

The deep-sea hydrothermal vent solenogaster Helicoradomenia is covered with calcium carbonate sclerites. Light and electron microscopy reveal varying morphologies of these sclerites. Many sclerites have hollow tips and/or are pitted and etched. Bacteria are found on and in sclerites. Initial sclerite formation occurs in an extracellular crystalline chamber formed by the invagination of a cuboidal basal cell of the columnar microvillus mantle epithelium. As the sclerite grows, it fills the crystalline chamber resulting in direct contact with the microvilli of both the basal cell and neighboring secondary sclerite-forming cells. These cells shape a collar around the base of the growing sclerite. As growth continues, the sclerite-forming cells stretch around the sclerite forming a sheath in which the base of the sclerite resides. Mature sclerites grow through the cuticle into the external environment. The erosion pattern of sclerites reveals a less stable inner medullary region and a harder outer cortical region. This points to a secondary character state, where foremost hollow acicular sclerites develop into solid sclerites. This is in agreement with the systematic position of the genus Helicoradomenia within Simrothiellidae, a taxon typically with hollow sclerites.     

Physiological responses of Pterocladia and Gelidium (Gelidiales,Rhodophyta) from the Azores,Portugal

Manometric studies were conducted on Pterocladia capillacea, Gelidium latifolium and Gelidium spinulosum from the Azores, Portugal to determine optimal values of temperature, light and salinity for growth. Physiological responses were considered in relation to vertical distribution patterns of these species commonly observed throughout the Azores. Optimal parameters for the growth of Pterocladia capillacea, Gelidium latifolium and G. spinulosum were 17 to 25 °C, a photon flux density between 200 and 300 µmol m^–2 s^–1 and salinities of 25 to 35.     

一株深海热液口嗜热芽孢杆菌SY27F代谢产物活性的研究

【目的】对一株来源于深海热液口嗜热芽孢杆菌的次生代谢产物进行抑菌活性和抗肿瘤活性的初步研究。【方法】采用纸片法和微量肉汤稀释法检测嗜热芽孢杆菌SY27F次生代谢产物的抑菌活性,采用CCK-8法测定其次生代谢产物的抗肿瘤活性。【结果】抑菌实验表明,嗜热芽孢杆菌代谢产物对大肠杆菌、金黄色葡萄球菌均有抑菌作用,其最低抑菌浓度分别为1.56 mg/mL和3.13 mg/mL;细胞实验表明,其代谢产物对肿瘤细胞A549、HepG2、HeLa、MCF-7均有一定的抑制作用,其半致死浓度分别为0.390、0.451、0.704、1.105 mg/mL;与人肝肿瘤细胞(HepG2)相比,其对人正常肝细胞(L02)表现出良好的生物相容性。【结论】嗜热芽孢杆菌SY27F次生代谢产物具有一定的抑菌和抗肿瘤活性,可为寻找新型抑菌抗肿瘤活性物质提供优质资源。     

Thermococcus chitonophagus sp. nov., a novel,chitin-degrading,hyperthermophilic archaeum from a deep-sea hydrothermal vent environment

From a hydrothermal vent site off the Mexican west coast (20°50′N, 109°06′W) at a depth of 2,600 m, a novel, hyperthermophilic, anaerobic archaeum was isolated. Cells were round to slightly irregular cocci, 1.2–2.5 μm in diameter and were motile by means of a tuft of flagella. The new isolate grew between 60 and 93°C (optimum: 85°C), from pH 3.5 to 9 (optimum: pH 6.7), and from 0.8 to 8% NaCl (optimum: 2%). The isolate was an obligate organotroph, using chitin, yeast extract, meat extract, and peptone for growth. Chitin was fermented to H₂, CO₂, NH₃, acetate, and formate. H₂S was formed in the presence of sulfur. The chitinoclastic enzyme system was oxygen-stable, cell-associated, and inducible by chitin. The cell wall was composed of a surface layer of hex- americ protein complexes arranged on a p6 lattice. The core lipids consisted of glycerol diphytanyl diethers and acyclic and cyclic glycerol diphytanyl tetraethers. The G+C content was 46.5 mol%. DNA/DNA hybridization and 16S rRNA sequencing indicated that the new isolate belongs to the genus Thermococcus, representing a new species, Thermococcus chitonophagus. The type strain is isolate GC74, DSM 10152. Received: 8 May 1995 / Accepted: 26 June 1995     

Structure of the exopolysaccharide of Vibrio diabolicus isolated from a deep-sea hydrothermal vent

The structure of the exopolysaccharide produced under laboratory conditions by Vibrio diabolicus, a bacterium recovered from a deep-sea hydrothermal vent, has been investigated using sugar and methylation analysis and NMR spectroscopy. The polysaccharide consists of a linear tetrasaccharide repeating unit with the following structure. -->3)-beta-D-Glcp Nac-(1-->4)-beta-D-Glcp A-(1-->4)-beta-D-Glcp A-(1-->4)-alpha-D-Galp NAc-(1-->     

Calispadella alata n. gen., n. sp., the first chaetognath recorded from a hydrothermal vent site (Mid-Atlantic Ridge)

Calispadella alata n. gen., n. sp., is the first chaetognathdescribed from a hydrothermal vent field (Mid-Atlantic Ridge,depth 1600 m). It belongs to the family Spadellidae (presenceof transverse muscles in trunk and long tail segment). Thereis a pair of lateral fins making no contact with the body posteriorly;these free wing-like extensions end in festoons provided distallywith patches of adhesive cells. This unique feature in a deepbentho-planktonic species can be seen as an adaptation to adhereat times to the substrate to resist local turbulences producedby the hydrothermal fluids. This may also indicate that thisnew genus is phylogenetically close to the neritic genus Paraspadella,which has adhesive finger-like processes. Calispadella alatais sexually precocious as reported for other deep chaetognaths,contrary to most deep living organisms which exhibit delayedsexual maturity. This feature might be a means to increase thepossibility of mating in scarce populations.     

Lebetimonas natsushimae sp. nov., a novel strictly anaerobic,moderately thermophilic chemoautotroph isolated from a deep-sea hydrothermal vent polychaete nest in the Mid-Okinawa Trough

A moderately thermophilic, strictly anaerobic, chemoautotrophic bacterium, designated strain HS1857^T, was isolated from a deep-sea hydrothermal vent at the Noho site in the Mid-Okinawa Trough. Strain HS1857^T grew between 35 and 63 °C (optimum 55 °C), in the presence of 10–55 g l^?1 NaCl (optimum 25 g l^?1), and pH 5.5–7.1 (optimum 6.4). Growth occurred with molecular hydrogen as the electron donor and elemental sulfur, nitrate, or selenate as the electron acceptors. Formate could serve as an alternative electron donor with nitrate as an electron acceptor. During growth with nitrate as the electron acceptor, strain HS1857^T produced ammonium and formed a biofilm. CO₂ was utilized as the sole carbon source. The G + C content of the genomic DNA was 33.2 mol%. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain HS1857^T is a member of the order Nautiliales, showing a sequence similarity of 95.0% with Lebetimonas acidiphila Pd55^T. The fatty acid composition was similar to that of L. acidiphila, which was dominated by C_18:0 (47.0%) and C_18:1 (23.7%). Based on the genomic, chemotaxonomic, phenotypic characteristics, the name Lebetimonas natsushimae sp. nov., is proposed. The type strain is HS1857^T (= NBRC 112478^T = DSM 104102^T).     

Aggregata bathytherma sp. nov. (Apicomplexa:Aggregatidae), a new coccidian parasite associated with a deep-sea hydrothermal vent octopus

Aggregata bathytherma sp. nov. is described from the digestive tract of Vulcanoctopus hydrothermalis, a deep-sea octopus recently discovered associated with hydrothermal vents in the northeast Pacific Ocean. Oocysts typically are spherical in shape, sometimes irregular, 163 to 356 microm in length, and 219 to 313 microm in width. Each oocyst contains from 50 to over 200 sporocysts. Sporocysts measure 27 to 32 microm in longest diameter. The cyst wall is smooth and 1 microm thick. Each sporocyst typically contains 14 to 17 sporozoites, 49 microm in length. Histological lesions associated with the presence of A. bathytherma include rupture of the basal membrane and detachment of the epithelial cells. In heavily infected areas, most of the tissue of the host digestive tract is replaced by parasites. A. bathytherma is the first Aggregata species described from a host that lives in association with hydrothermal vents, and the third species of Aggregata from eastern North Pacific waters.