scholarly journals Novel Chemoautotrophic Endosymbiosis between a Member of the Epsilonproteobacteria and the Hydrothermal-Vent Gastropod Alviniconcha aff. hessleri (Gastropoda: Provannidae) from the Indian Ocean

2005 ◽  
Vol 71 (9) ◽  
pp. 5440-5450 ◽  
Author(s):  
Yohey Suzuki ◽  
Takenori Sasaki ◽  
Masae Suzuki ◽  
Yuichi Nogi ◽  
Tetsuya Miwa ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Indian Ocean ◽  
Hydrothermal Vent ◽  
Fatty Acid Biosynthesis ◽  
Carbon Isotopic Composition ◽  
Rrna Gene ◽  
Bisphosphate Carboxylase ◽  
Carbon Isotopic ◽  
The Indian Ocean ◽  
Chemoautotrophic Bacteria

ABSTRACT The hydrothermal-vent gastropod Alviniconcha aff. hessleri from the Kairei hydrothermal field on the Central Indian Ridge houses bacterium-like cells internally in its greatly enlarged gill. A single 16S rRNA gene sequence was obtained from the DNA extract of the gill, and phylogenetic analysis placed the source organism within a lineage of the epsilon subdivision of the Proteobacteria. Fluorescence in situ hybridization analysis with an oligonucleotide probe targeting the specific epsilonproteobacterial subgroup showed the bacterium densely colonizing the gill filaments. Carbon isotopic homogeneity among the gastropod tissue parts, regardless of the abundance of the endosymbiont cells, suggests that the carbon isotopic composition of the endosymbiont biomass is approximately the same as that of the gastropod. Compound-specific carbon isotopic analysis revealed that fatty acids from the gastropod tissues are all 13C enriched relative to the gastropod biomass and that the monounsaturated C16 fatty acid that originates from the endosymbiont is as 13C enriched relative to the gastropod biomass as that of the epsilonproteobacterial cultures grown under chemoautotrophic conditions. This fractionation pattern is most likely due to chemoautotrophy based on the reductive tricarboxylic-acid (rTCA) cycle and subsequent fatty acid biosynthesis from 13C-enriched acetyl coenzyme A. Enzymatic characterization revealed evident activity of several key enzymes of the rTCA cycle, as well as the absence of ribulose-1,5-bisphosphate carboxylase/oxygenase activity in the gill tissue. The results from anatomic, molecular phylogenetic, bulk and compound-specific carbon isotopic, and enzymatic analyses all support the inference that a novel nutritional strategy relying on chemoautotrophy in the epsilonproteobacterial endosymbiont is utilized by the hydrothermal-vent gastropod from the Indian Ocean. The discrepancies between the data of the present study and those of previous ones for Alviniconcha gastropods from the Pacific Ocean imply that at least two lineages of chemoautotrophic bacteria, phylogenetically distinct at the subdivision level, occur as the primary endosymbiont in one host animal type.

scholarly journals A new species of the genus Smacigastes Ivanenko & Defaye, 2004 (Tegastidae, Harpacticoida, Copepoda) from the Onnuri Vent Field in the Indian Ocean

2020 ◽  
Vol 96 (2) ◽  
pp. 699-714
Author(s):  
Jong Guk Kim ◽  
Jimin Lee
Keyword(s):  
New Species ◽  
Indian Ocean ◽  
Hydrothermal Vent ◽  
Hydrothermal Vents ◽  
First Record ◽  
Cold Seeps ◽  
Dichotomous Key ◽  
The Family ◽  
The Indian Ocean ◽  
A New Species

The genus Smacigastes Ivanenko & Defaye, 2004 (Harpacticoida, Copepoda) is the most primitive genus in the family Tegastidae Sars, 1904, occurring in deep-sea chemosynthetic environments, such as hydrothermal vents, cold seeps, whale falls and wood falls. Our exploration of the Onnuri Vent Field, the sixth active hydrothermal vent system in the Central Indian Ridge, resulted in the discovery of a new species in the genus Smacigastes. A detailed morphological analysis of S. pumilasp. nov. reveals that it most resembles S. barti Gollner, Ivanenko & Martínez Arbizu, 2008, described from a hydrothermal vent in the East Pacific Ridge; the new species can be distinguished from the existing species by the 8-segmented female antennule, the absence of an abexopodal seta on the antennary basis, the mandibular exopod represented by a single seta and the exopod of the first leg with five setae. This is the first record of Smacigastes in the Indian Ocean. A dichotomous key to species of the genus Smacigastes worldwide is provided.

scholarly journals Pararhodobacter marinus sp. nov., isolated from deep-sea water of the Indian Ocean

2019 ◽  
Vol 69 (4) ◽  
pp. 932-936 ◽  
Author(s):  
Qiliang Lai ◽  
Xiupian Liu ◽  
Jun Yuan ◽  
Shuchen Xie ◽  
Zongze Shao
Keyword(s):  
Indian Ocean ◽  
Deep Sea ◽  
Type Species ◽  
Sea Water ◽  
Rrna Gene ◽  
Chromosomal Dna ◽  
Content Type ◽  
Deep Sea Water ◽  
Link Type ◽  
The Indian Ocean

A taxonomic study was carried out on strain CIC4N-9T, which was isolated from deep-sea water of the Indian Ocean. The bacterium was Gram-stain-negative, catalase- and oxidase-positive, rod-shaped and non-motile. Growth was observed at salinities of 0–9% and at temperatures of 4–41 °C. The isolate was able to degrade gelatin but not aesculin. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CIC4N-9T belonged to the genus Pararhodobacter , with the highest sequence similarity to the only recognized species, Pararhodobacter aggregans D1-19T (96.9 %). The average nucleotide identity and estimated DNA–DNA hybridization values between strain CIC4N-9T and P. aggregans D1-19T were 80.4 and 23.0 %, respectively. The principal fatty acids were summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c), C16 : 0, C18 : 1ω7c 11-methyl, C18 : 0 and C17 : 0. The G+C content of the chromosomal DNA was 66.8 mol%. The sole respiratory quinone was determined to be Q-10. Phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, two unknown phospholipids, four unknown aminolipids and one unknown polar lipid were present. The combined genotypic and phenotypic data show that strain CIC4N-9T represents a novel species within the genus Pararhodobacter , for which the name Pararhodobacter marinus sp. nov. is proposed. The type strain is CIC4N-9T (=MCCC 1A01225T=KCTC 52336T).

Occurrence of Conjugated Polyenoic Fatty Acids in Seaweeds from the Indian Ocean

2004 ◽  
Vol 59 (5-6) ◽  
pp. 310-314 ◽  
Author(s):  
Narayan Bhaskar ◽  
Tomohisa Kinami ◽  
Kazuo Miyashita ◽  
Si-Bum Park ◽  
Yasushi Endo ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Arachidonic Acid ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Indian Ocean ◽  
Eicosapentaenoic Acid ◽  
Acid Composition ◽  
Lipid Classes ◽  
Conjugated Polyenes ◽  
The Indian Ocean

Three species of red marine macro algae (Rhodophyta) from the Indian Ocean were analysed for the occurrence of conjugated polyenes. The composition of different lipid classes in these seaweeds along with their fatty acid composition has also been reported. Analysis of lipid classes of these seaweeds revealed that both Acanthophora spicifera (Ceramiales, Rhodophyta) and two species of Gracilaria, viz. G. edulis and G. folifera (Gracilariales, Rhodophyta) were rich in glycolipids followed by neutral- and phospholipids. The fatty acid composition of these seaweeds revealed C16:0 as the predominant fatty acid in all three species. However, A. spicifera had significantly higher amounts of eicosapentaenoic acid (EPA) and arachidonic acid (AA) as compared to negligible amount of these fatty acids in both species of Gracilaria. The red seaweed Acanthophora spicifera contained conjugated eicosapentaenoic acid (CEPA) and conjugated arachidonic acid (CAA) in all lipid classes except glycolipids.

scholarly journals Description of Barathricola thermophilus, a new species from a deep-sea hydrothermal vent field in the Indian Ocean with redescription of the Barathricola type species (Crustacea, Copepoda, Cyclopoida)

ZooKeys ◽  
2019 ◽  
Vol 865 ◽  
pp. 103-121 ◽  
Author(s):  
Viatcheslav N. Ivanenko ◽  
Jimin Lee ◽  
Cheon Young Chang ◽  
Il-Hoi Kim
Keyword(s):  
New Species ◽  
Indian Ocean ◽  
Deep Sea ◽  
Hydrothermal Vent ◽  
Type Species ◽  
Central Ridge ◽  
The Indian Ocean ◽  
Morphological Differences ◽  
Hydrothermal Vent Field ◽  
Copepoda Cyclopoida

Re-study of the type species of the genus Barathricola Humes, 1999 (Copepoda, Cyclopoida, Schminkepinellidae) described from the Pacific Ocean (Juan de Fuca Ridge), and study of the species Barathricolathermophilussp. nov. from a deep-sea hydrothermal vent field on the Central Ridge in the Indian Ocean revealed a derived feature and widespread geographic distribution of this deep-sea genus of cyclopoids. The derived feature of Barathricola is the sexually dimorphic third endopodal segment of leg 3 possessing a small outer terminal spine together with spine-like outgrowths on this segment. The new species differs from Barathricolarimensis Humes, 1999 in not expressing sexual dimorphism in leg 5, having three spines and one seta on its exopod in both sexes (B.rimensis has three spines and one seta on the female exopod but three spines and two setae on the male exopod) and in having broader caudal rami which are 8.9 times longer than wide in the female (this ratio for B.rimensis is 11). An amended diagnosis of the genus Barathricola, a key and a table of morphological differences for all species of Schminkepinellidae are given.

scholarly journals Acuticoccus sediminis sp. nov., isolated from deep-sea sediment of the Indian Ocean and proposal of Acuticoccaceae fam. nov

2019 ◽  
Vol 69 (4) ◽  
pp. 1173-1178 ◽  
Author(s):  
Qiliang Lai ◽  
Xiupian Liu ◽  
Fenqing Sun ◽  
Zongze Shao
Keyword(s):  
Indian Ocean ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Deep Sea ◽  
Sequence Similarity ◽  
Rrna Gene ◽  
Content Type ◽  
Deep Sea Sediment ◽  
Link Type ◽  
The Indian Ocean

A Gram-staining negative, aerobic, oval-shaped bacterium, designated strain PTG4-2T, was isolated from deep-sea sediment of the Indian Ocean. Growth was observed with 1–9 % (w/v) NaCl with optimal growth with 3 %, at pH 6.0–10.0 with an optimum of pH 7.0, and at 4–40 °C with an optimum of 30 °C. Positive for catalase and oxidase. The results of a 16S rRNA gene sequence comparison indicated that PTG4-2T was most closely related to Acuticoccus yangtzensis JL1095T (97.3 %), followed by Acuticoccus kandeliae J103T (96.5 %), all other species shared <93 % sequence similarity. The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that PTG4-2T forms a distinct lineage within the genus Acuticoccus , and revealed that the genus Acuticoccus forms a novel family-level clade in the order Rhizobiales . The ANI and the DNA–DNA hybridization estimate values between PTG4-2T and two type strains (A. yangtzensis JL1095T and A. kandeliae J103T) were 79.9–76.2 % and 23.1–20.8 %, respectively. PTG4-2T contained Q-10 as the predominant ubiquinone. The principal fatty acids (>5 %) were summed feature 8 [C18 : 1 ω7c/ω6c (72.2 %)], C18 : 0 (8.4 %), C20 : 1 ω7c (6.4 %) and C16 : 0 (6.3 %). The polar lipids consisted of phosphatidylglycerol, three unidentified phospholipids, two unidentified glycolipids, one unidentified aminolipid and one unknown lipid. The DNA G+C content of PTG4-2T is 69.2 mol%. On the basis of the polyphasic taxonomic evidence presented in this study, PTG4-2T should be classified as representing a novel species of the genus Acuticoccus , for which the name Acuticoccus sediminis sp. nov. is proposed, with the type strain PTG4-2T (=MCCC 1A01274T=KCTC 52323T). In addition, a novel family, Acuticoccaceae fam. nov., is proposed to accommodate the genus Acuticoccus .

scholarly journals DNA Barcoding of Scavenging Amphipod Communities at Active and Inactive Hydrothermal Vents in the Indian Ocean

2022 ◽  
Vol 8 ◽  
Author(s):  
Katharina Kniesz ◽  
Anna Maria Jażdżewska ◽  
Pedro Martínez Arbizu ◽  
Terue Cristina Kihara
Keyword(s):  
Indian Ocean ◽  
Hydrothermal Vents ◽  
Rrna Genes ◽  
Federal Institute ◽  
Species Complexes ◽  
Baited Traps ◽  
Reference Databases ◽  
The Indian Ocean ◽  
18S Rrna Genes ◽  
Chemoautotrophic Bacteria

Hydrothermal vent areas have drawn increasing interest since they were discovered in 1977. Because of chemoautotrophic bacteria, they possess high abundances of vent endemic species as well as many non-vent species around the fields. During the survey conducted by the Bundesanstalt für Geowissenschaften und Rohstoffe (Federal Institute for Geosciences and Natural Resources, BGR) to identify inactive polymetallic sulfide deposits along Central and Southeast Indian Ridges, the INDEX project studied the scavenging amphipod community at three newly discovered hydrothermal fields. A sample consisting of 463 representatives of Amphipoda (Malacostraca: Crustacea) was collected by means of baited traps in active and inactive vents of three different sites and subsequently studied by both morphological and genetic methods. Molecular methods included the analysis of two mitochondrial (cytochrome c oxidase subunit I [COI] and 16S rRNA) and one nuclear (18S rRNA) genes. By six delimitation methods, 22 molecular operational taxonomic units (MOTUs) belonging to 12 genera and 10 families were defined. The existence of potential species complexes was noted for the representatives of the genus Paralicella. The inactive site, where 19 species were found, showed higher species richness than did the active one, where only 10 taxa were recorded. Seven genera, Ambasiopsis, Cleonardo, Eurythenes, Parandania, Pseudonesimus, Tectovalopsis, and Valettiopsis, were observed only at inactive sites, whereas Haptocallisoma, was collected exclusively at active ones. The species Abyssorchomene distinctus (Birstein and Vinogradov, 1960), Hirondellea brevicaudata Chevreux, 1910, and Hirondellea guyoti Barnard and Ingram, 1990, have been previously reported from vent sites in the Atlantic or Pacific oceans. The present study provides the first report of Eurythenes magellanicus (H. Milne Edwards, 1848) and five other already described species in the Indian Ocean. The addition of 356 sequences strongly increases the number of amphipod barcodes in reference databases and provides for the first time COI barcodes for Cleonardo neuvillei Chevreux, 1908, Haptocallisoma abyssi (Oldevig, 1959), Hirondellea guyoti, Tectovalopsis fusilus Barnard and Ingram, 1990, and the genera Haptocallisoma, Pseudonesimus, and Valettiopsis.

scholarly journals Janibacter indicus sp. nov., isolated from hydrothermal sediment of the Indian Ocean

2014 ◽  
Vol 64 (Pt_7) ◽  
pp. 2353-2357 ◽  
Author(s):  
Gaiyun Zhang ◽  
Huihui Ren ◽  
Shuang Wang ◽  
Xiu Chen ◽  
Yanliu Yang ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Diaminopimelic Acid ◽  
Rrna Gene ◽  
Biochemical Tests ◽  
Content Type ◽  
Link Type ◽  
Gram Staining ◽  
Hydrothermal Sediment ◽  
Diamino Acid ◽  
The Indian Ocean

A Gram-staining-positive, aerobic and non-motile strain, 0704P10-1T, was isolated from hydrothermal sediment of the Indian Ocean. Phylogenetic, phenotypic and chemotaxonomic data for the organism supported that it belonged to the genus Janibacter . Strain 0704P10-1T showed 97.2–98.7 % 16S rRNA gene sequence similarities to the type strains of recognized members of the genus Janibacter . It contained meso-diaminopimelic acid as the diagnostic diamino acid in the cell wall. MK-8(H4) was the only menaquinone detected. The major fatty acids were iso-C16 : 0, C17 : 1ω8c and 10-methyl C17 : 0. Meanwhile, the results of DNA–DNA hybridization studies and other physiological and biochemical tests allowed the genotypic and phenotypic differentiation of strain 0704P10-1T from closely related species. Thus, strain 0704P10-1T represents a novel species of the genus Janibacter , for which the name Janibacter indicus sp. nov. is proposed. The type strain is 0704P10-1T ( = LMG 27493T = CGMCC 1.12511T).

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