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Sample records for calyptogena magnifica chemoautotrophic

  1. The Calyptogena magnifica chemoautotrophic symbiont genome

    Energy Technology Data Exchange (ETDEWEB)

    Newton, I.L.; Woyke, T.; Auchtung, T.A.; Dilly, G.F.; Dutton,R.J.; Fisher, M.C.; Fontanez, K.M.; Lau, E.; Stewart, F.J.; Richardson,P.M.; Barry, K.W.; Saunders, E.; Detter, J.C.; Wu, D.; Eisen, J.A.; Cavanaugh, C.M.

    2007-03-01

    Chemoautotrophic endosymbionts are the metabolic cornerstone of hydrothermal vent communities, providing invertebrate hosts with nearly all of their nutrition. The Calyptogena magnifica (Bivalvia: Vesicomyidae) symbiont, Candidatus Ruthia magnifica, is the first intracellular sulfur-oxidizing endosymbiont to have its genome sequenced, revealing a suite of metabolic capabilities. The genome encodes major chemoautotrophic pathways as well as pathways for biosynthesis of vitamins, cofactors, and all 20 amino acids required by the clam.

  2. Vulvar myiasis due to Wohlfahrtia magnifica.

    Science.gov (United States)

    Delir, S; Handjani, F; Emad, M; Ardehali, S

    1999-07-01

    Myiasis is a condition resulting from the invasion of tissues or organs of man or animals by the larvae of dipterous flies. The distribution of myiasis is worldwide, with more cases being reported from tropical, subtropical, and warm temperate areas. The various forms of myiasis may be classified from an entomological or a clinical point of view. This report describes a rare case of vulvar myiasis due to Wohlfahrtia magnifica in an otherwise healthy 20-year-old Iranian female. To our knowledge, this is the first report of cutaneous myiasis of the vulva due to W. magnifica from Iran and the Middle East region.

  3. Periungual myiasis caused by wohlfahrtia magnifica mimicking an ingrown toenail

    OpenAIRE

    Boscarelli, Alessandro; Levi Sandri, Giovanni Battista

    2016-01-01

    Myiasis is the infestation of organs and tissues of human being or other vertebrate animals with dipterous larvae. Myiasis is generally rare in humans, especially in children. We present the first case of periungual myiasis by Wohlfahrtia magnifica in a 5-year-old female. Wohlfahrtia magnifica is an obligatory parasite, which has been described as cause of ophthalmomyiasis, otomyiasis, oral myiasis, vulvar myiasis and wound myiasis. Treatment of myiasis and ingrown toenail is generally non-op...

  4. Periungual myiasis caused by wohlfahrtia magnifica mimicking an ingrown toenail.

    Science.gov (United States)

    Boscarelli, Alessandro; Levi Sandri, Giovanni Battista

    2016-04-01

    Myiasis is the infestation of organs and tissues of human being or other vertebrate animals with dipterous larvae. Myiasis is generally rare in humans, especially in children. We present the first case of periungual myiasis by Wohlfahrtia magnifica in a 5-year-old female. Wohlfahrtia magnifica is an obligatory parasite, which has been described as cause of ophthalmomyiasis, otomyiasis, oral myiasis, vulvar myiasis and wound myiasis. Treatment of myiasis and ingrown toenail is generally non-operative although both entities can be serious and/or non-responsive to conservative therapy.

  5. NMR studies of chalcones isolated from Neoraputia magnifica; Estudos por RMN de chalconas isoladas de Neoraputia magnifica

    Energy Technology Data Exchange (ETDEWEB)

    Tomazela, Daniela M.; Rodrigues Filho, Edson; Silva, M. Fatima das G. F. da; Fernandes, Joao B.; Vieira, Paulo C. [Sao Carlos Univ., SP (Brazil). Dept. de Quimica

    1997-12-31

    From Neoraputia magnifica (Rutaceae) we isolated two chalcones belonging to the 1,3-diarylprop-2-en-1-one group. The two chalcones presented two or three methoxyl groups at ring B; a dimethychromene between C-5`and O-6`and also an additional methoxyl at ring A. It has been noted that H-{beta} and C-{beta} of a chalcone are more deshielded than H-{alpha}. However, HMOC and HMBC experiments of the chalcones described here showed the opposite situation where H-{alpha} is more deshielded than H-{beta}. (author) 5 refs., 4 figs., 7 tabs.

  6. [A case of gingival myiasis caused by Wohlfahrtia magnifica].

    Science.gov (United States)

    Çetın Özdemır, Eda; Ekşi, Fahriye; Şenyurt, Süleyman Ziya; Üstün, Kemal; Karaoğlan, İlkay; Ercıyas, Kamile

    2014-07-01

    Myiasis is an infestation of living or dead tissue of humans and animals by diptera larvae. Gingival myiasis is a rare pathology and is mainly associated with poor oral hygiene, alcoholism, senility, suppurative lesions, mouth breathing, mental retardation and hemiplegia. Myiasis is most common during summer since the fly population increases during this season. Mostly it occurs in farmers and people who live in tropical climates. Gingival myiasis in humans in Turkey is limited to only a few cases. According to our literature research, this is the first case of gingival myiasis produced by larvae of Wohlfahrtia magnifica in a Turkish adult. According to our best knowledge, it is also the first gingival myiasis case that one of the causative larva had grown to the adult stage in Turkey. A 43 years old male patient who perceived the presence of live maggots in his mouth was referred to our clinic. Clinical findings of gingival myiasis were observed. The patient had no history of systemic disease but oral hygiene was poor. Clinical and radiographic examination indicated that he had chronic periodontitis. Before the dental treatment seven larvae and during the scalling five larvae were elevated from the gingival sulcus. The body of the larvae composed of 12 segments and they were 8-10 mm in length. One of the larvae which was sent to the microbiology laboratory were placed into sheep liver to resume life and the other larvae were placed into 70% alcohol solution. After 9-10 days, the larva which was placed in the liver became pupa. Approximately 15 days later, the pupa became an adult fly. The larvae were identified as the second stage larvae of Wohlfahrtia magnifica. Treatment consisted of removal of the maggots from the gingival sulcus, followed by scaling and oral hygiene instruction. Non-surgical periodontal treatment was applied and the patient was followed-up for 3 months. After non-surgical periodontal treatment, patient didn't accept the flap operation. The

  7. The Sequestration of Oxy-Polybrominated Diphenyl Ethers in the Nudibranchs Miamira magnifica and Miamira miamirana

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    Ariyanti S. Dewi

    2016-10-01

    Full Text Available A series of oxy-polybrominated diphenyl ethers (O-PBDEs has been isolated from the extracts of Miamira magnifica and Miamira miamirana collected from Queensland, Australia. M. magnifica sequesters the new OH-PBDE 1 and six known OH-PBDEs containing four to six bromines (2–7. M. miamirana also accumulates known tribromo- and tetrabromo OMe-PBDEs 8–10 in both mantle and viscera tissues. To date, Miamira is the only genus of the family Chromodorididae that is known to incorporate O-PBDEs, rather than terpenes, in the mantle where the metabolites may play a putative role in chemical defense. The extract of M. magnifica was tested in a brine shrimp lethality assay and exhibited an LD50 of 58 μg/mL.

  8. Pectinatella magnifica (Leidy, 1851) (Bryozoa, Phylactolaemata), a biofouling bryozoan recently introduced to China

    Science.gov (United States)

    Wang, Baoqiang; Wang, Hongzhu; Cui, Yongde

    2016-09-01

    Freshwater biofouling threatens a variety of human activities, from the supply of water and energy to recreation. Several species of freshwater bryozoans are notorious for clogging pipes and filters but have been relatively poorly studied to date. We report, for the first time, a biofouling species of freshwater bryozoan, Pectinatella magnifica (Leidy, 1851), from several freshwater rivers, lakes and ponds in China. A complete description, national distribution and the fouling problems are provided. Exactly how Pectinatella magnifica arrived in China remains unclear, but anthropochory and zoochory are considered to be important dispersal pathways.

  9. The Sequestration of Oxy-Polybrominated Diphenyl Ethers in the Nudibranchs Miamira magnifica and Miamira miamirana

    OpenAIRE

    2016-01-01

    A series of oxy-polybrominated diphenyl ethers (O-PBDEs) has been isolated from the extracts of Miamira magnifica and Miamira miamirana collected from Queensland, Australia. M. magnifica sequesters the new OH-PBDE 1 and six known OH-PBDEs containing four to six bromines (2–7). M. miamirana also accumulates known tribromo- and tetrabromo OMe-PBDEs 8–10 in both mantle and viscera tissues. To date, Miamira is the only genus of the family Chromodorididae that is known to incorporate O-PBDEs, rath...

  10. Methods and systems for chemoautotrophic production of organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Curt R.; Che, Austin J.; Shetty, Reshma P.; Kelly, Jason R.

    2013-01-08

    The present disclosure identifies pathways, mechanisms, systems and methods to confer chemoautotrophic production of carbon-based products of interest, such as sugars, alcohols, chemicals, amino acids, polymers, fatty acids and their derivatives, hydrocarbons, isoprenoids, and intermediates thereof, in organisms such that these organisms efficiently convert inorganic carbon to organic carbon-based products of interest using inorganic energy, such as formate, and in particular the use of organisms for the commercial production of various carbon-based products of interest.

  11. Exclusive localization of carbonic anhydrase in bacteriocytes of the deep-sea clam Calyptogena okutanii with thioautotrophic symbiotic bacteria.

    Science.gov (United States)

    Hongo, Yuki; Nakamura, Yoshimitsu; Shimamura, Shigeru; Takaki, Yoshihiro; Uematsu, Katsuyuki; Toyofuku, Takashi; Hirayama, Hisako; Takai, Ken; Nakazawa, Masatoshi; Maruyama, Tadashi; Yoshida, Takao

    2013-12-01

    Deep-sea Calyptogena clams harbor thioautotrophic intracellular symbiotic bacteria in their gill epithelial cells. The symbiont fixes CO2 to synthesize organic compounds. Carbonic anhydrase (CA) from the host catalyzes the reaction CO2 + H2O ↔ HCO3(-) + H(+), and is assumed to facilitate inorganic carbon (Ci) uptake and transport to the symbiont. However, the localization of CA in gill tissue remains unknown. We therefore analyzed mRNA sequences, proteins and CA activity in Calyptogena okutanii using expression sequence tag, SDS-PAGE and LC-MS/MS. We found that acetazolamide-sensitive soluble CA was abundantly expressed in the gill tissue of C. okutanii, and the enzyme was purified by affinity chromatography. Mouse monoclonal antibodies against the CA of C. okutanii were used in western blot analysis and immunofluorescence staining of the gill tissues of C. okutanii, which showed that CA was exclusively localized in the symbiont-harboring cells (bacteriocytes) in gill epithelial cells. Western blot analysis and measurement of activity showed that CA was abundantly (26-72% of total soluble protein) detected in the gill tissues of not only Calyptogena clams but also deep-sea Bathymodiolus mussels that harbor thioautotrophic or methanotrophic symbiotic bacteria, but was not detected in a non-symbiotic mussel, Mytilus sp. The present study showed that CA is abundant in the gill tissues of deep-sea symbiotic bivalves and specifically localizes in the cytoplasm of bacteriocytes of C. okutanii. This indicates that the Ci supply process to symbionts in the vacuole (symbiosome) in bacteriocytes is essential for symbiosis.

  12. World-wide distribution of the Bryozoan Pectinatella magnifica (Leidy 1851

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    Zuzana Balounová

    2013-12-01

    Full Text Available Pectinatella magnifica (Leidy 1851 is an invasive freshwater colonial animal belonging to the phylum Bryozoa. It is native to the area east of the Mississippi River, from Ontario to Florida. Currently it occurs throughout North America and the first record for it outside that continent was for Bille near Hamburg in 1883. Later, it was found in the Elbe (Havel by Spandau, in Tegeler See, a pond in Wroclaw and in Silesia and Brandenburg. In addition, floatoblasts of P. magnifica were found in the upper Elbe in Germany in the 1950s. Then, P. magnifica spread to the area of Spandau in Berlin and the Oder, and Wroclaw. It is also recorded in Romania and Turkey. In France, it was recorded occurring in the area called Franche-Comte in 1994. Its occurrence in the Netherlands was first reported in 2003 and then each following year. The newest discoveries are for the Rhine basin in the area between Luxembourg and Germany. Recently, it was also recorded in the Czech Republic and Austria. Besides Europe and North America, it is also recorded in Japan and Korea. The statoblasts of P. magnifica are spread by flowing water, zoochory and probably also by anthropochory.

  13. Broad-scale Population Genetics of the Host Sea Anemone, Heteractis magnifica

    KAUST Repository

    Emms, Madeleine

    2015-12-01

    Broad-scale population genetics can reveal population structure across an organism’s entire range, which can enable us to determine the most efficient population-wide management strategy depending on levels of connectivity. Genetic variation and differences in genetic diversity on small-scales have been reported in anemones, but nothing is known about their broad-scale population structure, including that of “host” anemone species, which are increasingly being targeted in the aquarium trade. In this study, microsatellite markers were used as a tool to determine the population structure of a sessile, host anemone species, Heteractis magnifica, across the Indo-Pacific region. In addition, two rDNA markers were used to identify Symbiodinium from the samples, and phylogenetic analyses were used to measure diversity and geographic distribution of Symbiodinium across the region. Significant population structure was identified in H. magnifica across the Indo-Pacific, with at least three genetic breaks, possibly the result of factors such as geographic distance, geographic isolation and environmental variation. Symbiodinium associations were also affected by environmental variation and supported the geographic isolation of some regions. These results suggests that management of H. magnifica must be implemented on a local scale, due to the lack of connectivity between clusters. This study also provides further evidence for the combined effects of geographic distance and environmental distance in explaining genetic variance.

  14. Immune Response Evaluation in Sheep Infected with Larvae of Wohlfahrtia Magnifica

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    Daniela Marina Mot

    2013-05-01

    Full Text Available The sheep myiasis is a seriously debilitating disease that has the potential to generate a substantial stress to affected animals. All lesions severity and animals state of health can be retrieved in immunological parameters detection, because always results an immune response to challenge factors which intercede in their productive life. Today is important to find non-chemical methods of ectoparasites control, from natural resistance or vaccine induced resistance. The study was carried out to infected and uninfected sheep with larvae of Wohlfahrtia magnifica. From two groups of healthy and parasited sheep were been taken blood samples. From the group from sheep with myiasis were been detected the cutaneous lesions with W. magnifica maggots and these maggots were been collected. The mechanisms of unspecific immune defending were been studied through cellular effectors by leucogram. In leucogram appear quantitative differences between different categories of cells which take part in immune response, such as polymorphonuclears (neutrophiles, eozinophiles and mononuclears (limphocytes.  The immune specific answer were been detected through radial simple immunodiffusion test made with antigen prepared from W. magnifica maggots from the third stage of development, in the view of estimating the presence of an immune reaction through antibodies synthesis in infested sheep. In both studies were been detected immune responses of parasite hosts. All immunological studies may allow a sustainable ectoparasites control utilizing host resistance which seems to be attainable in the near future.

  15. NCBI nr-aa BLAST: CBRC-HSAP-05-0051 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-HSAP-05-0051 ref|YP_903576.1| nicotinate (nicotinamide) nucleotide adenylyltransferase [Candidatus Ruth...adenylyltransferase [Candidatus Ruthia magnifica str. Cm (Calyptogena magnifica)] YP_903576.1 1.1 34% ...

  16. NCBI nr-aa BLAST: CBRC-PTRO-06-0046 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-PTRO-06-0046 ref|YP_903576.1| nicotinate (nicotinamide) nucleotide adenylyltransferase [Candidatus Ruth...adenylyltransferase [Candidatus Ruthia magnifica str. Cm (Calyptogena magnifica)] YP_903576.1 1.1 34% ...

  17. Genomic and population genetic analysis of deep-sea vent chemoautotrophs

    Science.gov (United States)

    Nakagawa, S.; Shimamura, S.; Takaki, Y.; Mino, S.; Makita, H.; Sawabe, T.; Takai, K.

    2012-12-01

    Deep-sea vents are the light-independent, highly productive ecosystems driven primarily by chemoautotrophs. Most of the invertebrates thrive there through their relationship with symbiotic chemoautotrophs. Chemoautotrophs are microorganisms that are able to fix inorganic carbon using a chemical energy obtained through the oxidation of reduced compounds. Following the discovery of deep-sea vent ecosystems in 1977, there has been an increasing knowledge that deep-sea vent chemoautotrophs display remarkable physiological and phylogenetic diversity. Recent microbiological studies have led to an emerging view that the majority of deep-sea vent chemoautotrophs have the ability to derive energy from multiple redox couples other than the conventional sulfur-oxygen couple. Genomic, metagenomic and postgenomic studies have considerably accelerated the comprehensive understanding of molecular mechanisms of deep-sea vent chemoautotrophy, even in unculturable endosymbionts of vent fauna. For example, genomic analysis suggested that there were previously unrecognized evolutionary links between deep-sea vent chemoautotrophs and important human/animal pathogens. However, relatively little is known about the genome of horizontally transmitted endosymbionts. In this study, we sequenced whole genomes of the probably horizontally transmitted endosymbionts of two different gastropod species from a deep-sea hydrothermal field, as an effort to address questions about 1) the genome evolution of horizontally transmitted, facultative endosymbionts, 2) their genomic variability, and 3) genetic differences among symbionts of various deep-sea vent invertebrates. Both endosymbiont genomes display features consistent with ongoing genome reduction such as large proportions of pseudogenes and transposable elements. The genomes encode multiple functions for chemoautotrophic respirations, probably reflecting their adaptation to their niches with continuous changes in environmental conditions. When

  18. Antifouling activity by sea anemone (Heteractis magnifica and H. aurora extracts against marine biofilm bacteria Actividades antiincrustantes de las extractos de las anémonas marinas Heteractis magnifica y H. aurora frente a biofilm de bacterias marinas

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    Subramanian Bragadeeswaran

    2011-07-01

    Full Text Available Sea anemones (Actiniaria are solitary, ocean-dwelling members of the phylum Cnidaria and the class Anthozoa. In this study, we screened antibacterial activity of two benthic sea anemones (Heteractis magnifica and H. aurora collected from the Mandapam coast of southeast India. Crude extracts of the sea anemone were assayed against seven bacterial biofilms isolated from three different test panels. The crude extract of H. magnifica showed a maximum inhibition zone of 18 mm against Pseudomonas sp. and Escherichia coli and a minimum inhibition zone of 3 mm against Pseudomonas aeruginosa, Micrococcus sp., and Bacillus cerens for methanol, acetone, and DCM extracts, respectively. The butanol extract of H. aurora showed a maximum inhibition zone of 23 mm against Vibrio parahaemolyticus, whereas the methanol extract revealed a minimum inhibition zone of 1 mm against V. parahaemolyticus. The present study revealed that the H. aurora extracts were more effective than those of H. magnifica and that the active compounds from the sea anemone can be used as antifouling compounds.Las anémonas de mar (Actiniaria son solitarias, habitantes oceánicos del phylum Cnidaria y de la clase Anthozoa. En este estudio se determina la actividad antibacteriana de dos anémonas bentónicas Heteractis magnifica y H. aurora recolectadas en la costa de Mandapam, sudeste de India. Los extractos crudos de estas anémonas fueron ensayados frente a siete biofilms bacterianos aislados de tres paneles de control distintos. El extracto crudo de la anémona H. magnifica mostró una zona inhibición máxima de 18 mm contra Psudomonas sp. y Escherichia coli y la zona de inhibición mínima de 3 mm fue encontrada frente a Pseudomonas aeruginosa, Micrococus sp. y Bacillus cerens de extractos de metanol, acetona y DCM respectivamente. El extracto de butanol de la anémona H. magnifica mostró una zona de inhibición máxima de 23 mm frente a Vibrio parahemolyticus, mientras que con el

  19. Traumatic myiasis agents in Iran with introducing of new dominant species, Wohlfahrtia magnifica (Diptera:Sarcophagidae)

    Institute of Scientific and Technical Information of China (English)

    Javad Rafinejad; Kamran Akbarzadeh; Yavar Rassi; Jamasp Nozari; Mohammad Mehdi Sedaghat; Mostafa Hosseini; Hamzeh Alipour; Abdolmajid Ranjbar; Danial Zeinali

    2014-01-01

    Objective: To study agents of animal wound myiasis in various geographical districts of Fars province.Methods:of 10358 domestic animals have been visited from April 2011 to March 2012. The infected wounds in any parts of animal body were sampled by means of forceps.Results:This study has been done in Fars province, located in the southern part of Iran. Sums The most wound myiasis cases due to this species occurred in central part of Fars province. There wasn’t any significant difference between sheep and goat in infestation with myiasis (P>0.05). The infestation rate of myiasis in cattle community was 0.86%. About 61% of all animal wound myiasis were caused by larvae of Wohlfahrtia magnifica. Conclusions: The infestation rate of livestock was lower than other works in Iran and some other countries like Saudi Arabia. Chrysomya bezziana has been mentioned as main myiasis agent in Iran. But in this study it cleared that similarly to some European countries, the common animal myiasis agent in Iran is Wohlfahrtia magnifica. Introducing new species as principal agent for myiasis can help public health and animal husbandry policy makers to prepare sufficient and effective control and/or preventive measures for this disease.

  20. Purification and characterization of two new allergens from the venom of Vespa magnifica.

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    An, Su; Chen, Lingling; Wei, Ji-Fu; Yang, Xuening; Ma, Dongying; Xu, Xuemei; Xu, Xueqing; He, Shaoheng; Lu, Jia; Lai, Ren

    2012-01-01

    Due to poor diagnostic facilities and a lack of medical alertness, allergy to Vespa wasps may be underestimated. Few allergens have been identified from Vespa wasps.Possible native allergen proteins were purified from the wasp venoms (WV) (Vespa magnifica Smith) by gel filtration, ion exchange chromatography, respectively. Their sequences were determined by Edman degradation and cDNA cloning. Their allergenicities were assayed by enzyme-linked immunosorbent assay inhibition tests (ELISA-IT), immunoblots, and skin prick tests (SPTs). Their cross allergencities with Tab y 2 and Tab y 5 purified from the horsefly (Tabanus yao Macquart) were also determined. Two native allergens were identified from the WV, respectively. They are a 25-KDa antigen 5 protein (Ag5) (Vesp ma 5) and a 35-KDa hyaluronidase (Vesp ma 2). They represented major allergens in Vespa magnifica by immunoblots and SPTs. ELISA inhibition of pooled sera IgE reactivity to both the WV and the horsefly salivary gland extracts (HSGE) using four purified allergens (Vesp ma 2, Vesp ma 5 and previously purified Tab y 2 and Tab y 5) was significant. Their cross allergenicities were confirmed by ELISA-IT, immunoblots, and SPTs. They represented the cross reactive allergens from wasp and horsefly and proved the so called wasp-horsefly syndrome.

  1. Purification and characterization of two new allergens from the venom of Vespa magnifica.

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    Su An

    Full Text Available Due to poor diagnostic facilities and a lack of medical alertness, allergy to Vespa wasps may be underestimated. Few allergens have been identified from Vespa wasps.Possible native allergen proteins were purified from the wasp venoms (WV (Vespa magnifica Smith by gel filtration, ion exchange chromatography, respectively. Their sequences were determined by Edman degradation and cDNA cloning. Their allergenicities were assayed by enzyme-linked immunosorbent assay inhibition tests (ELISA-IT, immunoblots, and skin prick tests (SPTs. Their cross allergencities with Tab y 2 and Tab y 5 purified from the horsefly (Tabanus yao Macquart were also determined. Two native allergens were identified from the WV, respectively. They are a 25-KDa antigen 5 protein (Ag5 (Vesp ma 5 and a 35-KDa hyaluronidase (Vesp ma 2. They represented major allergens in Vespa magnifica by immunoblots and SPTs. ELISA inhibition of pooled sera IgE reactivity to both the WV and the horsefly salivary gland extracts (HSGE using four purified allergens (Vesp ma 2, Vesp ma 5 and previously purified Tab y 2 and Tab y 5 was significant. Their cross allergenicities were confirmed by ELISA-IT, immunoblots, and SPTs. They represented the cross reactive allergens from wasp and horsefly and proved the so called wasp-horsefly syndrome.

  2. Metabolic evolution of a deep-branching hyperthermophilic chemoautotrophic bacterium.

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    Rogier Braakman

    Full Text Available Aquifex aeolicus is a deep-branching hyperthermophilic chemoautotrophic bacterium restricted to hydrothermal vents and hot springs. These characteristics make it an excellent model system for studying the early evolution of metabolism. Here we present the whole-genome metabolic network of this organism and examine in detail the driving forces that have shaped it. We make extensive use of phylometabolic analysis, a method we recently introduced that generates trees of metabolic phenotypes by integrating phylogenetic and metabolic constraints. We reconstruct the evolution of a range of metabolic sub-systems, including the reductive citric acid (rTCA cycle, as well as the biosynthesis and functional roles of several amino acids and cofactors. We show that A. aeolicus uses the reconstructed ancestral pathways within many of these sub-systems, and highlight how the evolutionary interconnections between sub-systems facilitated several key innovations. Our analyses further highlight three general classes of driving forces in metabolic evolution. One is the duplication and divergence of genes for enzymes as these progress from lower to higher substrate specificity, improving the kinetics of certain sub-systems. A second is the kinetic optimization of established pathways through fusion of enzymes, or their organization into larger complexes. The third is the minimization of the ATP unit cost to synthesize biomass, improving thermodynamic efficiency. Quantifying the distribution of these classes of innovations across metabolic sub-systems and across the tree of life will allow us to assess how a tradeoff between maximizing growth rate and growth efficiency has shaped the long-term metabolic evolution of the biosphere.

  3. Molecular genetic analysis of populations of Wohlfahrt's wound myiasis fly, Wohlfahrtia magnifica, in outbreak populations from Greece and Morocco.

    Science.gov (United States)

    Hall, M J R; Testa, J M; Smith, L; Adams, Z J O; Khallaayoune, K; Sotiraki, S; Stefanakis, A; Farkas, R; Ready, P D

    2009-06-01

    Wohlfahrt's wound myiasis fly, Wohlfahrtia magnifica (Schiner) (Diptera: Sarcophagidae), is the most important cause of traumatic myiasis in the southern Palaearctic region. Larval stages are obligate parasites and the wounds caused by infestations are very similar to those caused by Old and New World screwworm flies. During the last decade, W. magnifica appears to have expanded its range to parts of northern and central Morocco, and to Crete, Greece. Specimens of W. magnifica were collected in Morocco and Crete either as larvae (preserved in 80% ethanol) or as adults (dry-pinned). Comparison specimens were collected in Spain, Hungary and mainland Greece. A DNA fragment containing the 3' 715 base pairs of the mitochondrial cytochrome b gene was amplified by polymerase chain reaction from each of 132 larvae or adults of W. magnifica and the amplicons were directly sequenced and analysed phylogeographically. Twelve cytochrome b haplotypes were detected. All haplotypes from Morocco belonged to a lineage that included specimens from the Iberian peninsula, and restricted mixing of central and northern populations in Morocco was demonstrated. Cytochrome b haplotyping combined with an analysis of larval size provided clear evidence of multiple infestations of hosts in all geographical areas, with one quarter of wounds containing larvae from two to at least four females. More than 80% of specimens from Crete contained a haplotype predominating in mainland Greece and Hungary. Our survey indicated that wohlfahrtiosis was more widespread in northern and central Morocco than previously recorded by government veterinarians. However, the prevalence of wohlfahrtiosis was low (< 1%). The high genetic diversity of Moroccan populations is consistent with longterm endemicity, rather than recent introduction. Crete showed a higher prevalence of wohlfahrtiosis (< or = 15%) and less genetic diversity of W. magnifica, which is consistent with a recent introduction. The western and

  4. PECTINATELLA MAGNIFICA LEIDY 1851 (PHYLACTOLAEMATES, UN BRYOZOAIRE INTRODUIT DANS LE NORD FRANCHE-COMTÉ.

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    RODRIGUEZ S.

    2002-04-01

    Full Text Available A partir de l’observation initiale d’une colonie du bryozoaire Pectinatella magnifica Leidy 1851 dans le nord Franche-Comté (été 1994 et d’une analyse bibliographique, un suivi de l’extension de l’espèce a été effectué sur le territoire franc-comtois et dans les régions limitrophes. La localisation des stations est assortie de valeurs de qualité d’eau mesurées sur le réseau hydrographique franc-comtois pour le compte de l’Agence de l’Eau Rhône-Méditerranée-Corse. La rédaction d’une fiche d’enquête nationale vise à collecter des informations sur ce bryozoaire afin d’en faciliter ultérieurement la gestion.

  5. Community structure and soil pH determine chemoautotrophic carbon dioxide fixation in drained paddy soils.

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    Long, Xi-En; Yao, Huaiying; Wang, Juan; Huang, Ying; Singh, Brajesh K; Zhu, Yong-Guan

    2015-06-16

    Previous studies suggested that microbial photosynthesis plays a potential role in paddy fields, but little is known about chemoautotrophic carbon fixers in drained paddy soils. We conducted a microcosm study using soil samples from five paddy fields to determine the environmental factors and quantify key functional microbial taxa involved in chemoautotrophic carbon fixation. We used stable isotope probing in combination with phospholipid fatty acid (PLFA) and molecular approaches. The amount of microbial (13)CO2 fixation was determined by quantification of (13)C-enriched fatty acid methyl esters and ranged from 21.28 to 72.48 ng of (13)C (g of dry soil)(-1), and the corresponding ratio (labeled PLFA-C:total PLFA-C) ranged from 0.06 to 0.49%. The amount of incorporationof (13)CO2 into PLFAs significantly increased with soil pH except at pH 7.8. PLFA and high-throughput sequencing results indicated a dominant role of Gram-negative bacteria or proteobacteria in (13)CO2 fixation. Correlation analysis indicated a significant association between microbial community structure and carbon fixation. We provide direct evidence of chemoautotrophic C fixation in soils with statistical evidence of microbial community structure regulation of inorganic carbon fixation in the paddy soil ecosystem.

  6. Vertical transmission of chemoautotrophic symbionts in the bivalve Solemya velum (Bivalvia: Protobranchia).

    Science.gov (United States)

    Krueger, D M; Gustafson, R G; Cavanaugh, C M

    1996-04-01

    Adults of the bivalve species Solemya velum live in symbiosis with chemoautotrophic bacteria in specialized gill bacteriocytes. The bacteria play an essential nutritional role in the mature association, fixing CO2 via the Calvin cycle with energy obtained through the oxidation of reduced sulfur compounds. To understand how the continuity of this partnership is maintained between host generations, we investigated the mode of symbiont transfer in S. velum. A diagnostic assay using the polymerase chain reaction and primers specific for the S. velum symbiont ribulose-1,5-bisphosphate carboxylase (RubisCO) gene consistently detected bacterial sequence in female gonad tissue, suggesting the presence of symbiont cells in host ovaries and a vertical mode of symbiont transmission from mother to offspring. Furthermore, intracellular bacteria were present in the developing gills of juveniles that had not yet hatched from the gelatinous capsule in which larval development occurs (11 days after fertilization). By 64 days postfertilization, the typical adult gill ultrastructure of alternating bacteriocytes and symbiont-free-intercalary cells was apparent. Knowledge about the mode of symbiont transfer in S. velum allows further study into the dynamics of host-symbiont interactions in chemoautotrophic associations.

  7. Fine-scale population structure of two anemones (Stichodactyla gigantea and Heteractis magnifica) in Kimbe Bay, Papua New Guinea

    KAUST Repository

    Gatins, Remy

    2014-12-01

    Anemonefish are one of the main groups that have been used over the last decade to empirically measure larval dispersal and connectivity in coral reef populations. A few species of anemones are integral to the life history of these fish, as well as other obligate symbionts, yet the biology and population structure of these anemones remains poorly understood. The aim of this study was to measure the genetic structure of these anemones within and between two reefs in order to assess their reproductive mode and dispersal potential. To do this, we sampled almost exhaustively two anemones species (Stichodactyla gigantea and Heteractis magnifica) at two small islands in Kimbe Bay (Papua New Guinea) separated by approximately 25 km. Both the host anemones and the anemonefish are heavily targeted for the aquarium trade, in addition to the populations being affected by bleaching pressures (Hill and Scott 2012; Hobbs et al. 2013; Saenz- Agudelo et al. 2011; Thomas et al. 2014), therefore understanding their biology is crucial for better management strategies. Panels of microsatellite markers were developed for each species using next generation sequencing tools. Clonality analyses confirm six pairs of identical genotypes for S. gigantea (n=350) and zero for H. magnifica (n=128), indicating presence/absence of asexual reproduction in this region. S. gigantea showed low structure between islands (FST= 0.003, p-value= 0.000), however, even if the majority of the individuals were unrelated (r~0), 81 families that shared 50% of their genetic material formed from two to four members were found. Out of these families, 45% were found with individuals only within Tuare Island, 11% only in Kimbe Island, and 44% were sharing individuals among islands. In comparison, H. magnifica showed no structure (FST= 0.002, p-value= 0.278), mean relatedness indicated the majority of individuals were unrelated, and 31 families were identified. Families again consisted from two to four members and

  8. Purification of a 19-kDa pore-forming cytolysin from the sea anemone Heteractis magnifica

    Directory of Open Access Journals (Sweden)

    S Karthikayalu

    2010-01-01

    Full Text Available Pore-forming cytolysins of 19 kDa from sea anemones present a remarkable cytolytic property. In the present work, a purified 19-kDa cytolysin was obtained from the sea anemone Heteractis magnifica. The purification steps involved ammonium sulfate precipitation and subsequently desalting by dialysis against 10 mM sodium phosphate buffer (pH 7.4, followed by anion exchange chromatography in DEAE-Sepharose® column (GE Healthcare, Sweden and gel filtration chromatography using Sephadex® G-50 matrix (GE Healthcare, Sweden. The active fractions from the gel filtration chromatography were pooled and rechromatographed in the same column. The final active fraction showed a prominent protein band of molecular mass of 19 kDa when analyzed by SDS-PAGE.

  9. CO2 uptake and fixation by endosymbiotic chemoautotrophs from the bivalve Solemya velum.

    Science.gov (United States)

    Scott, Kathleen M; Cavanaugh, Colleen M

    2007-02-01

    Chemoautotrophic symbioses, in which endosymbiotic bacteria are the major source of organic carbon for the host, are found in marine habitats where sulfide and oxygen coexist. The purpose of this study was to determine the influence of pH, alternate sulfur sources, and electron acceptors on carbon fixation and to investigate which form(s) of inorganic carbon is taken up and fixed by the gamma-proteobacterial endosymbionts of the protobranch bivalve Solemya velum. Symbiont-enriched suspensions were generated by homogenization of S. velum gills, followed by velocity centrifugation to pellet the symbiont cells. Carbon fixation was measured by incubating the cells with (14)C-labeled dissolved inorganic carbon. When oxygen was present, both sulfide and thiosulfate stimulated carbon fixation; however, elevated levels of either sulfide (>0.5 mM) or oxygen (1 mM) were inhibitory. In the absence of oxygen, nitrate did not enhance carbon fixation rates when sulfide was present. Symbionts fixed carbon most rapidly between pH 7.5 and 8.5. Under optimal pH, sulfide, and oxygen conditions, symbiont carbon fixation rates correlated with the concentrations of extracellular CO(2) and not with HCO(3)(-) concentrations. The half-saturation constant for carbon fixation with respect to extracellular dissolved CO(2) was 28 +/- 3 microM, and the average maximal velocity was 50.8 +/- 7.1 micromol min(-1) g of protein(-1). The reliance of S. velum symbionts on extracellular CO(2) is consistent with their intracellular lifestyle, since HCO(3)(-) utilization would require protein-mediated transport across the bacteriocyte membrane, perisymbiont vacuole membrane, and symbiont outer and inner membranes. The use of CO(2) may be a general trait shared with many symbioses with an intracellular chemoautotrophic partner.

  10. Characterization, purification and phylogenetic analysis of a cytolysin from the sea anemone Heteractis magnifica of the Indian Ocean

    Directory of Open Access Journals (Sweden)

    S Karthikayalu

    2010-01-01

    Full Text Available It is well established that sea anemones comprise a rich source of cytolytic toxins. The present study reports the isolation and characterization of a cytolysin obtained from the sea anemone Heteractis magnifica collected in the Andaman Islands of the Indian Ocean. The crude extract was screened for hemolytic activity by a blood agar plate method and a 6-mm zone of clearance was observed after incubation. The hemolytic property of the crude extract, tested by the microtiter plate method, revealed positive results at concentrations as low as 120 ng/mL. Furthermore, it was favored by alkaline pH and was stable up to 60°C. On the other hand, the hemolytic effect was abolished by the addition of human serum. Purification steps involved ammonium sulfate precipitation and subsequent desalting by dialysis, followed by anion- and cation-exchange chromatographies. The purified fractions displayed the presence of a 19-kDa cytolysin when analyzed by SDS-PAGE. The conserved region of the cytolysin (with 303 bp was amplified by RT-PCR and was sequenced. The sequence showed maximum homology (97% with the already reported cytolysins from other sea anemone species.

  11. The Biogeochemistry beneath the Whillans Ice Stream, West Antarctica: Evidence for a Chemoautotrophically Driven Ecosystem

    Science.gov (United States)

    Purcell, A.; Mikucki, J.; Achberger, A.; Christner, B. C.; Michaud, A. B.; Mitchell, A. C.; Priscu, J. C.; Skidmore, M. L.; Vick-Majors, T.

    2015-12-01

    Antarctic sub ice environments represent some of the most understudied microbial ecosystems on Earth. The Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) project recently sampled sediments and water from Subglacial Lake Whillans (SLW) and its hydrologically connected grounding zone where this lake system empties beneath the Ross Ice Shelf. Here we highlight findings on the diversity and metabolic capabilities of the microbial community detected in these samples. We utilized a hot water drill with a novel filtration and UV treatment system to insure that our entry and sampling did not contaminate our samples or the pristine subglacial ecosystem. Geochemical and microbiological data suggests the water column hosts an active microbial community sustained by the production of fixed carbon from chemosynthesis with energy derived from reduced nitrogen, sulfur, and iron compounds. These energy sources appear to be influenced by bedrock weathering at the sediment surface. For example, dominant 16S rRNA gene phylotypes in the water column suggest ammonia oxidation as a potential source of chemoautotrophic energy. While in the SLW surficial sediments, diversity analysis of functional genes involved in both sulfur oxidation and sulfate reduction (aprA, dsrA, and rdsrA), aprA gene abundance, and 16S rRNA gene analysis indicate that sulfur-oxidizing microbes are dominant. These preliminary results represents the first data on microbial community structure and function from an Antarctic subglacial lake and its grounding zone.

  12. Metatranscriptional response of chemoautotrophic Ifremeria nautilei endosymbionts to differing sulfur regimes

    Directory of Open Access Journals (Sweden)

    Sherry L Seston

    2016-07-01

    Full Text Available Endosymbioses between animals and chemoautotrophic bacteria are ubiquitous at hydrothermal vents. These environments are distinguished by high physico-chemical variability, yet we know little about how these symbioses respond to environmental fluctuations. We therefore examined how the γ-proteobacterial symbionts of the vent snail Ifremeria nautilei respond to changes in sulfur geochemistry. Via shipboard high-pressure incubations, we subjected snails to 105 µM hydrogen sulfide (LS, 350 µM hydrogen sulfide (HS, 300 µM thiosulfate (TS and seawater without any added inorganic electron donor (ND. While transcript levels of sulfur oxidation genes were largely consistent across treatments, HS and TS treatments stimulated genes for denitrification, nitrogen assimilation, and CO2 fixation, coincident with previously reported enhanced rates of inorganic carbon incorporation and sulfur oxidation in these treatments. Transcripts for genes mediating oxidative damage were enriched in the ND and LS treatments, potentially due to a reduction in O2 scavenging when electron donors were scarce. Oxidative TCA cycle gene transcripts were also more abundant in ND and LS treatments, suggesting that I. nautilei symbionts may be mixotrophic when inorganic electron donors are limiting. These data reveal the extent to which I. nautilei symbionts respond to changes in sulfur concentration and species, and, interpreted alongside coupled biochemical metabolic rates, identify gene targets whose expression patterns may be predictive of holobiont physiology in environmental samples.

  13. Cultivation of a chemoautotroph from the SUP05 clade of marine bacteria that produces nitrite and consumes ammonium

    Science.gov (United States)

    Shah, Vega; Chang, Bonnie X; Morris, Robert M

    2017-01-01

    Marine oxygen minimum zones (OMZs) are expanding regions of intense nitrogen cycling. Up to half of the nitrogen available for marine organisms is removed from the ocean in these regions. Metagenomic studies have identified an abundant group of sulfur-oxidizing bacteria (SUP05) with the genetic potential for nitrogen cycling and loss in OMZs. However, SUP05 have defied cultivation and their physiology remains untested. We cultured, sequenced and tested the physiology of an isolate from the SUP05 clade. We describe a facultatively anaerobic sulfur-oxidizing chemolithoautotroph that produces nitrite and consumes ammonium under anaerobic conditions. Genetic evidence that closely related strains are abundant at nitrite maxima in OMZs suggests that sulfur-oxidizing chemoautotrophs from the SUP05 clade are a potential source of nitrite, fueling competing nitrogen removal processes in the ocean. PMID:27434424

  14. Phylogenetic relationships of chemoautotrophic bacterial symbionts of Solemya velum say (Mollusca: Bivalvia) determined by 16S rRNA gene sequence analysis.

    Science.gov (United States)

    Eisen, J A; Smith, S W; Cavanaugh, C M

    1992-05-01

    The protobranch bivalve Solemya velum Say (Mollusca: Bivalvia) houses chemoautotrophic symbionts intracellularly within its gills. These symbionts were characterized through sequencing of polymerase chain reaction-amplified 16S rRNA coding regions and hybridization of an Escherichia coli gene probe to S. velum genomic DNA restriction fragments. The symbionts appeared to have only one copy of the 16S rRNA gene. The lack of variability in the 16S sequence and hybridization patterns within and between individual S. velum organisms suggested that one species of symbiont is dominant within and specific for this host species. Phylogenetic analysis of the 16S sequences of the symbionts indicates that they lie within the chemoautotrophic cluster of the gamma subdivision of the eubacterial group Proteobacteria.

  15. Phylogenetic relationships of chemoautotrophic bacterial symbionts of Solemya velum say (Mollusca: Bivalvia) determined by 16S rRNA gene sequence analysis.

    OpenAIRE

    Eisen, J. A.; Smith, S W; Cavanaugh, Colleen Marie

    1992-01-01

    The protobranch bivalve Solemya velum Say (Mollusca: Bivalvia) houses chemoautotrophic symbionts intracellularly within its gills. These symbionts were characterized through sequencing of polymerase chain reaction-amplified 16S rRNA coding regions and hybridization of an Escherichia coli gene probe to S. velum genomic DNA restriction fragments. The symbionts appeared to have only one copy of the 16S rRNA gene. The lack of variability in the 16S sequence and hybridization patterns within and b...

  16. Anaerobic oxidation of arsenite in Mono Lake water and by a facultative, arsenite-oxidizing chemoautotroph, strain MLHE-1

    Science.gov (United States)

    Oremland, R.S.; Hoeft, S.E.; Santini, J.M.; Bano, N.; Hollibaugh, R.A.; Hollibaugh, J.T.

    2002-01-01

    Arsenite [As(III)]-enriched anoxic bottom water from Mono Lake, California, produced arsenate [As(V)] during incubation with either nitrate or nitrite. No such oxidation occurred in killed controls or in live samples incubated without added nitrate or nitrite. A small amount of biological As(III) oxidation was observed in samples amended with Fe(III) chelated with nitrolotriacetic acid, although some chemical oxidation was also evident in killed controls. A pure culture, strain MLHE-1, that was capable of growth with As(III) as its electron donor and nitrate as its electron acceptor was isolated in a defined mineral salts medium. Cells were also able to grow in nitrate-mineral salts medium by using H2 or sulfide as their electron donor in lieu of As(III). Arsenite-grown cells demonstrated dark 14CO2 fixation, and PCR was used to indicate the presence of a gene encoding ribulose-1,5-biphosphate carboxylase/oxygenase. Strain MLHE-1 is a facultative chemoautotroph, able to grow with these inorganic electron donors and nitrate as its electron acceptor, but heterotrophic growth on acetate was also observed under both aerobic and anaerobic (nitrate) conditions. Phylogenetic analysis of its 16S ribosomal DNA sequence placed strain MLHE-1 within the haloalkaliphilic Ectothiorhodospira of the ??-Proteobacteria. Arsenite oxidation has never been reported for any members of this subgroup of the Proteobacteria.

  17. Development and characterization of new polymorphic microsatellite markers in four sea anemones: Entacmaea quadricolor, Heteractis magnifica, Stichodactyla gigantea, and Stichodactyla mertensii

    KAUST Repository

    Gatins, Remy

    2016-10-08

    Relatively few studies have investigated the genetic population structure of sea anemones. This is particularly true for sea anemones that host some of the most iconic fishes on coral reefs, the anemonefishes. One of the main reasons for this knowledge gap is the lack of appropriate genetic markers. We developed and characterized a total of 47 novel polymorphic microsatellite markers for four host sea anemone species from the Indo-Pacific: Entacmaea quadricolor (n = 16 microsatellite markers), Heteractis magnifica (n = 8), Stichodactyla mertensii (n = 13), and Stichodactyla gigantea (n = 10). Here, we report genetic diversity statistics from two different sampling locations for each anemone species. Overall, we found that most markers were highly polymorphic. On average, we found a mean of seven alleles per locus. Observed and expected heterozygosities displayed high variation among loci, ranging from 0.033 to 0.980 and from 0.038 to 0.927, respectively. Only four loci showed deviations of Hardy–Weinberg equilibrium in both populations and were identified as having null alleles. Additionally, two pairs of loci were identified to be in linkage disequilibrium in only one population. Host anemones are highly sought after in the marine aquarium trade and are susceptible to thermal bleaching. Although most studies focus on their obligate symbionts (the anemonefish), genetic analyses of host sea anemones can expand our understanding of the biology, connectivity, and population structure of these organisms and potentially help develop conservation strategies that will aid both the host and its symbionts.

  18. Characterization and expression of genes from the RubisCO gene cluster of the chemoautotrophic symbiont of Solemya velum: cbbLSQO.

    Science.gov (United States)

    Schwedock, Julie; Harmer, Tara L; Scott, Kathleen M; Hektor, Harm J; Seitz, Angelica P; Fontana, Matthew C; Distel, Daniel L; Cavanaugh, Colleen M

    2004-09-01

    Chemoautotrophic endosymbionts residing in Solemya velum gills provide this shallow water clam with most of its nutritional requirements. The cbb gene cluster of the S. velum symbiont, including cbbL and cbbS, which encode the large and small subunits of the carbon-fixing enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO), was cloned and expressed in Escherichia coli. The recombinant RubisCO had a high specific activity, approximately 3 micromol min(-1) mg protein (-1), and a KCO2 of 40.3 microM. Based on sequence identity and phylogenetic analyses, these genes encode a form IA RubisCO, both subunits of which are closely related to those of the symbiont of the deep-sea hydrothermal vent gastropod Alviniconcha hessleri and the photosynthetic bacterium Allochromatium vinosum. In the cbb gene cluster of the S. velum symbiont, the cbbLS genes were followed by cbbQ and cbbO, which are found in some but not all cbb gene clusters and whose products are implicated in enhancing RubisCO activity post-translationally. cbbQ shares sequence similarity with nirQ and norQ, found in denitrification clusters of Pseudomonas stutzeri and Paracoccus denitrificans. The 3' region of cbbO from the S. velum symbiont, like that of the three other known cbbO genes, shares similarity to the 3' region of norD in the denitrification cluster. This is the first study to explore the cbb gene structure for a chemoautotrophic endosymbiont, which is critical both as an initial step in evaluating cbb operon structure in chemoautotrophic endosymbionts and in understanding the patterns and forces governing RubisCO evolution and physiology.

  19. Influence of form IA RubisCO and environmental dissolved inorganic carbon on the delta13C of the clam-chemoautotroph symbiosis Solemya velum.

    Science.gov (United States)

    Scott, Kathleen M; Schwedock, Julie; Schrag, Daniel P; Cavanaugh, Colleen M

    2004-12-01

    Many nutritive symbioses between chemoautotrophic bacteria and invertebrates, such as Solemya velum, have delta(13)C values of approximately -30 to -35%, considerably more depleted than phytoplankton. Most of the chemoautotrophic symbionts fix carbon with a form IA ribulose 1,5-bisphosphate carboxylase (RubisCO). We hypothesized that this form of RubisCO discriminates against (13)CO(2) to a greater extent than other forms. Solemya velum symbiont RubisCO was cloned and expressed in Escherichia coli, purified and characterized. Enzyme from this recombinant system fixed carbon most rapidly at pH 7.5 and 20-25 degrees C. Surprisingly, this RubisCO had an epsilon-value (proportional to the degree to which the enzyme discriminates against (13)CO(2)) of 24.4 per thousand, similar to form IB RubisCOs, and higher than form II RubisCOs. Samples of interstitial water from S. velum's habitat were collected to determine whether the dissolved inorganic carbon (DIC) could contribute to the negative delta(13)C values. Solemya velum habitat DIC was present at high concentrations (up to approximately 5 mM) and isotopically depleted, with delta(13)C values as low as approximately -6%. Thus environmental DIC, coupled with a high degree of isotopic fractionation by symbiont RubisCO likely contribute to the isotopically depleted delta(13)C values of S. velum biomass, highlighting the necessity of considering factors at all levels (from environmental to enzymatic) in interpreting stable isotope ratios.

  20. Culture-Independent Identification of Manganese-Oxidizing Genes from Deep-Sea Hydrothermal Vent Chemoautotrophic Ferromanganese Microbial Communities Using a Metagenomic Approach

    Science.gov (United States)

    Davis, R.; Tebo, B. M.

    2013-12-01

    Microbial activity has long been recognized as being important to the fate of manganese (Mn) in hydrothermal systems, yet we know very little about the organisms that catalyze Mn oxidation, the mechanisms by which Mn is oxidized or the physiological function that Mn oxidation serves in these hydrothermal systems. Hydrothermal vents with thick ferromanganese microbial mats and Mn oxide-coated rocks observed throughout the Pacific Ring of Fire are ideal models to study the mechanisms of microbial Mn oxidation, as well as primary productivity in these metal-cycling ecosystems. We sampled ferromanganese microbial mats from Vai Lili Vent Field (Tmax=43°C) located on the Eastern Lau Spreading Center and Mn oxide-encrusted rhyolytic pumice (4°C) from Niua South Seamount on the Tonga Volcanic Arc. Metagenomic libraries were constructed and assembled from these samples and key genes known to be involved in Mn oxidation and carbon fixation pathways were identified in the reconstructed genomes. The Vai Lili metagenome assembled to form 121,157 contiguous sequences (contigs) greater than 1000bp in length, with an N50 of 8,261bp and a total metagenome size of 593 Mbp. Contigs were binned using an emergent self-organizing map of tetranucleotide frequencies. Putative homologs of the multicopper Mn-oxidase MnxG were found in the metagenome that were related to both the Pseudomonas-like and Bacillus-like forms of the enzyme. The bins containing the Pseudomonas-like mnxG genes are most closely related to uncultured Deltaproteobacteria and Chloroflexi. The Deltaproteobacteria bin appears to be an obligate anaerobe with possible chemoautotrophic metabolisms, while the Chloroflexi appears to be a heterotrophic organism. The metagenome from the Mn-stained pumice was assembled into 122,092 contigs greater than 1000bp in length with an N50 of 7635 and a metagenome size of 385 Mbp. Both forms of mnxG genes are present in this metagenome as well as the genes encoding the putative Mn

  1. Alkalilimnicola ehrlichii sp. nov., a novel, arsenite-oxidizing haloalkaliphilic gammaproteobacterium capable of chemoautotrophic or heterotrophic growth with nitrate or oxygen as the electron acceptor

    Science.gov (United States)

    Hoeft, S.E.; Blum, J.S.; Stolz, J.F.; Tabita, F.R.; Witte, B.; King, G.M.; Santini, J.M.; Oremland, R.S.

    2007-01-01

    A facultative chemoautotrophic bacterium, strain MLHE-1T, was isolated from Mono Lake, an alkaline hypersaline soda lake in California, USA. Cells of strain MLHE-1T were Gram-negative, short motile rods that grew with inorganic electron donors (arsenite, hydrogen, sulfide or thiosulfate) coupled with the reduction of nitrate to nitrite. No aerobic growth was attained with arsenite or sulfide, but hydrogen sustained both aerobic and anaerobic growth. No growth occurred when nitrite or nitrous oxide was substituted for nitrate. Heterotrophic growth was observed under aerobic and anaerobic (nitrate) conditions. Cells of strain MLHE-1T could oxidize but not grow on CO, while CH4 neither supported growth nor was it oxidized. When grown chemoautotrophically, strain MLHE-1T assimilated inorganic carbon via the Calvin-Benson-Bassham reductive pentose phosphate pathway, with the activity of ribulose 1,5-bisphosphate carboxylase (RuBisCO) functioning optimally at 0.1 M NaCl and at pH 7.3. Strain MLHE-1T grew over broad ranges of pH (7.3-10.0; optimum, 9.3), salinity (115-190 g l-1; optimum 30 g l-1) and temperature (113-40 ??C; optimum, 30 ??C). Phylogenetic analysis of 16S rRNA gene sequences placed strain MLHE-1T in the class Gammaproteobacteria (family Ectothiorhodospiraceae) and most closely related to Alkalispirillum mobile (98.5%) and Alkalilimnicola halodurans (98.6%), although none of these three haloalkaliphilic micro-organisms were capable of photoautotrophic growth and only strain MLHE-1T was able to oxidize As(III). On the basis of physiological characteristics and DNA-DNA hybridization data, it is suggested that strain MLHE-1T represents a novel species within the genus Alkalilimnicola for which the name Alkalilimnicola ehrlichii is proposed. The type strain is MLHE-1T (=DSM 17681T =ATCC BAA-1101T). Aspects of the annotated full genome of Alkalilimnicola ehrlichii are discussed in the light of its physiology. ?? 2007 IUMS.

  2. Colonoscopia com magnificação de imagem no diagnóstico de carcinoma colorretal invasivo da submucosa na polipose adenomatosa familiar Magnifying colonoscopy diagnosis of submucosal invasive colorectal carcinoma in familial adenomatous polyposis

    Directory of Open Access Journals (Sweden)

    Cláudio TARTA

    2000-04-01

    Full Text Available O desenvolvimento da colonoscopia com magnificação de imagem possibilitou o estudo detalhado da mucosa colônica e o diagnóstico diferencial entre lesões neoplásicas e não-neoplásicas, a partir da observação dos pit patterns. Os resultados são comparáveis à estereomicroscopia, sendo possível, assim, presumir o diagnóstico histológico. Foi realizada colonoscopia com magnificação de imagem em paciente portadora de polipose adenomatosa familiar, demonstrando-se com este método, a diversidade de lesões polipóides benignas e as apresentações morfológicas do câncer colorretal precoce. Nesta paciente, a avaliação por magnificação (videocolonoscópio FUJINON 410 - CM -- 40X, combinada à cromoscopia com indigo carmine 0,4%, demonstrou ampla variedade de lesões distribuídas por todo o cólon: lesão de espalhamento lateral no ceco com padrão IIIL + IV, pólipos subpediculados e sésseis distribuídos pelo cólon com padrão tipo IIIL, pólipo subpediculado no cólon transverso com diâmetro aproximado de 2,0 cm e padrão IV + V, lesões plano-elevadas tipo IIIL e no cólon sigmóide lesão IIa + IIc, com padrão V de Kudo. A avaliação dos pit patterns de lesões no cólon transverso e sigmóide permitiu o diagnóstico endoscópico de lesão com invasão de submucosa.The development of colonoscopy with image magnification has enable to study the colonic mucosa in detail and to do differential diagnosis between neoplastic and non-neoplastic lesions from the observation of pit patterns. The results are comparable to stereomicroscopy being possible to predict the histologic diagnosis. In a patient with familial adenomatous polyposis magnifying colonoscopy was performed and this method demonstrated a wide variaton of benign polypoid lesions and the morphological features of early colorectal cancer. In this patient, the evaluation by image magnification, together with indigo carmin 0,4% chromoscopy, showed a wide variety of

  3. Formation of Zn- and Fe-sulfides near hydrothermal vents at the Eastern Lau Spreading Center: implications for sulfide bioavailability to chemoautotrophs

    Directory of Open Access Journals (Sweden)

    Yucel Mustafa

    2008-05-01

    Full Text Available Abstract Background The speciation of dissolved sulfide in the water immediately surrounding deep-ocean hydrothermal vents is critical to chemoautotrophic organisms that are the primary producers of these ecosystems. The objective of this research was to identify the role of Zn and Fe for controlling the speciation of sulfide in the hydrothermal vent fields at the Eastern Lau Spreading Center (ELSC in the southern Pacific Ocean. Compared to other well-studied hydrothermal systems in the Pacific, the ELSC is notable for unique ridge characteristics and gradients over short distances along the north-south ridge axis. Results In June 2005, diffuse-flow ( 250°C vent fluids were collected from four field sites along the ELSC ridge axis. Total and filtered Zn and Fe concentrations were quantified in the vent fluid samples using voltammetric and spectrometric analyses. The results indicated north-to-south variability in vent fluid composition. In the high temperature vent fluids, the ratio of total Fe to total Zn varied from 39 at Kilo Moana, the most northern site, to less than 7 at the other three sites. The concentrations of total Zn, Fe, and acid-volatile sulfide indicated that oversaturation and precipitation of sphalerite (ZnS(s and pyrite (FeS2(s were possible during cooling of the vent fluids as they mixed with the surrounding seawater. In contrast, most samples were undersaturated with respect to mackinawite (FeS(s. The reactivity of Zn(II in the filtered samples was tested by adding Cu(II to the samples to induce metal-exchange reactions. In a portion of the samples, the concentration of labile Zn2+ increased after the addition of Cu(II, indicating the presence of strongly-bound Zn(II species such as ZnS clusters and nanoparticles. Conclusion Results of this study suggest that Zn is important to sulfide speciation at ELSC vent habitats, particularly at the southern sites where Zn concentrations increase relative to Fe. As the hydrothermal

  4. Colonoscopia com magnificação de imagem: análise da variação interobservadores para os padrões de criptas e comparação das imagens endoscópicas com os achados histopatológicos Magnification colonoscopy images: analysis of variation interobservers for pit patern and comparison of endoscopy and histopatologic findings

    Directory of Open Access Journals (Sweden)

    Esdras Camargo Andrade Zanoni

    2006-12-01

    Full Text Available A colonoscopia com magnificação de imagem (CMI é considerada uma técnica que possibilita o diagnóstico diferencial entre lesões colorretais neoplásicas e não-neoplásicas. Este estudo avaliou a variação da concordância interobservadores para os padrões de criptas através de três endoscopistas experientes com a classificação de Kudo, e correlacionou esses aspectos morfológicos com os achados histopatológicos. Um total de 213 imagens de lesões magnificadas (polipóides e planas forma coletadas de 161 pacientes consecutivos e apresentadas a três observadores independentes que expressaram opinião sobre o padrão de criptas predominante. Todas as lesões foram completamente excisadas e enviadas para estudo histopatológico. A estatística estimada de Kappa mostrou que o índice de concordância geral para padrões de criptas entre os três observadores foi bom (0,561. Com relação aos resultados histapatológicos, quando comparados aos padrões de criptas, observou-se: acuária de 84%; sensibilidade de 91,4%; especifidade de 67,2%; valor preditivo positivo de 86,6% valor preditivo negativo de 79,3% e índice de Kappa de 0,61. Embora a reprodutilidade interobservadores dos padrões de criptas seja boa, a CMI não deve substituir o estudo histopatológico, pois não diferencia com a necessária segurança lesões neoplásicas de lesões não-neoplásicas.Colonoscopy with magnified view is the most reliable nonbiopsy method for distinguishing non-neoplastic from neoplastic colorectal lesions. This study analysed lhe interobserver concordance in diagnosis of pit patem, with 3 experients endoscopists using Kudo Classification and correlating the this aspects with histological ones. A total of 213 magnificated images injuries (polipoides and plain had been collected of 161 independent observing patients consecutive and presented tres that had expressed opinion on the predominant standard of criptas. All the injuries had been

  5. AcEST: DK959539 [AcEST

    Lifescience Database Archive (English)

    Full Text Available TST39A01NGRL0004_P13 599 Adiantum capillus-veneris mRNA. clone: TST39A01NGRL0004_P13. 5' end sequence. DK95...9539 - Show DK959539 Clone id TST39A01NGRL0004_P13 Library TST39 Length 599 Definiti...on Adiantum capillus-veneris mRNA. clone: TST39A01NGRL0004_P13. 5' end sequence. Accession DK959539 Tissue t...database search programs, Nucleic Acids Res. 25:3389-3402. Query= DK959539|Adiantum capillus-veneris mRNA, c...a magnifica subsp. Calyptogena magnifica GN=rpoC PE=3 SV=1 Length = 1395 Score = 30.4 bits (67), Expect = 7.

  6. Nutritional strategies of the hydrothermal ecosystem bivalves

    Science.gov (United States)

    Le Pennec, Marcel; Donval, Anne; Herry, Angèle

    Studies of deep-sea hydrothermal bivalves have revealed that the species, which are strictly dependent upon the interstitial fluid emissions, derive their food indirectly via symbiotic relationships with chemosynthetic bacteria present in their gill tissues. As the gill plays the main trophic role, structural and ultrastructural modifications occur in the digestive tract. Scanning and transmission electron microscope studies reveal that the digestive system of species belonging to the genera Calyptogena, Bathymodiolus and Bathypecten have anatomical differences. In Calyptogena, the reduction of several parts of the digestive tract and the stomach content which is either empty or full, according to the various species examined indicate that the digestive system is hardly if at all functional. In Bathymodiolus, the labial palps are well developed, the stomach is always full with particles and the two cellular types, digestive and secretory, are present in the digestive gland. All these characteristics indicate that the digestive system is functional. In Bathypecten, the digestive tract is well developed and it seems that it plays the main trophic role. We conclude that the nutritional strategies of the hydrothermal vents bivalves are quite varied. They range from a normal trophic process, through a mixotrophic diet, to one based purely on chemoautotrophic bacteria. The strategy of each species is adapted to and influences its distribution.

  7. A process economic assessment of hydrocarbon biofuels production using chemoautotrophic organisms

    Energy Technology Data Exchange (ETDEWEB)

    Khan, NE; Myers, JA; Tuerk, AL; Curtis, WR

    2014-11-01

    Economic analysis of an ARPA-e Electrofuels (http://arpa-e.energy.gov/?q=arpa-e-programs/electrofuels) process is presented, utilizing metabolically engineered Rhodobacter capsulatus or Ralstonia eutropha to produce the C30+ hydrocarbon fuel, botryococcene, from hydrogen, carbon dioxide, and oxygen. The analysis is based on an Aspen plus (R) bioreactor model taking into account experimentally determined Rba. capsulatus and Rls. eutropha growth and maintenance requirements, reactor residence time, correlations for gas-liquid mass-transfer coefficient, gas composition, and specific cellular fuel productivity. Based on reactor simulation results encompassing technically relevant parameter ranges, the capital and operating costs of the process were estimated for 5000 bbl-fuel/day plant and used to predict fuel cost. Under the assumptions used in this analysis and crude oil prices, the Levelized Cost of Electricity (LCOE) required for economic feasibility must be less than 2(sic)/kWh. While not feasible under current market prices and costs, this work identifies key variables impacting process cost and discusses potential alternative paths toward economic feasibility. (C) 2014 Elsevier Ltd. All rights reserved.

  8. A process economic assessment of hydrocarbon biofuels production using chemoautotrophic organisms.

    Science.gov (United States)

    Khan, Nymul E; Myers, John A; Tuerk, Amalie L; Curtis, Wayne R

    2014-11-01

    Economic analysis of an ARPA-e Electrofuels (http://arpa-e.energy.gov/?q=arpa-e-programs/electrofuels) process is presented, utilizing metabolically engineered Rhodobacter capsulatus or Ralstonia eutropha to produce the C30+ hydrocarbon fuel, botryococcene, from hydrogen, carbon dioxide, and oxygen. The analysis is based on an Aspen plus® bioreactor model taking into account experimentally determined Rba. capsulatus and Rls. eutropha growth and maintenance requirements, reactor residence time, correlations for gas-liquid mass-transfer coefficient, gas composition, and specific cellular fuel productivity. Based on reactor simulation results encompassing technically relevant parameter ranges, the capital and operating costs of the process were estimated for 5000 bbl-fuel/day plant and used to predict fuel cost. Under the assumptions used in this analysis and crude oil prices, the Levelized Cost of Electricity (LCOE) required for economic feasibility must be less than 2¢/kWh. While not feasible under current market prices and costs, this work identifies key variables impacting process cost and discusses potential alternative paths toward economic feasibility.

  9. Chromodoris magnifica (Quoy & Gaimard, 1832), a new nudibranch host for the shrimp Periclimenes imperator Bruce, 1967 (Pontoniinae)

    NARCIS (Netherlands)

    Fransen, C.H.J.M.; Goud, J.

    1999-01-01

    During the NNM/Maluku Expedition 1996, in the framework of the NNM Fauna Malesiana Marine Program, a shrimp belonging to the species Periclimenes imperator Bruce, 1967, was found on a nudibranch while diving at 20 m depth in Seri Bay, on the south coast of Ambon. Periclimens imperator has been recor

  10. Arsenic oxidation capabilities of a chemoautotrophic bacterial population: Use for the treatment of an arsenic contaminated wastewater

    Science.gov (United States)

    Dictor, M.-C.; Battaglia-Brunet, F.; Garrido, F.; Baranger, P.

    2003-05-01

    An autotrophic bacterial population, named CAsOl, able to oxidise arsenic has been isolated from a former gold mine (Saint-Yrieix, France). This bacterial population was composed of two microorganisms: a bacterial strain close to Ralstonia picketii and the second one related to Thiomonas genus (identification by 16S rDNA sequencing). This microbial consortium was able to oxidise arsenic with CO2 as the carbon source, arsenite as electron donor and oxygen as electron accepter. A significant oxidising activity was observed in a pH range comprised between 3 to 8 (pH optimum 5 7). A laboratory experiment for the biological treatment of a synthetic effluent containing 100 mg.L^{-1} of arsenic has been carried out. A mineral support, pouzzolana, has been colonised by the population CAsOl and the column was fed continuously with a synthetic medium in order to determine the maximal arsenic oxidation rate and the optimal residence time. In our experimental conditions, the maximum arsenic oxidation rate was 3,9 g As(Ill). L^{-1}.day^{-1} with a residence time of 1 hour after 55 days of continuous running. The performance of our bacterial population for arsenite oxidation in arsenic contaminated wastewater are especially important in the case of a treatment of arsenious wastewater as it presents advantages compared to physico-chemical treatments (consumption and cost of chemicals, potential toxic by-products generation...).

  11. Organization and regulation of the arsenite oxidase operon of the moderately acidophilic and facultative chemoautotrophic Thiomonas arsenitoxydans.

    Science.gov (United States)

    Slyemi, Djamila; Moinier, Danielle; Talla, Emmanuel; Bonnefoy, Violaine

    2013-11-01

    Thiomonas arsenitoxydans is an acidophilic and facultatively autotrophic bacterium that can grow by oxidizing arsenite to arsenate. A comparative genomic analysis showed that the T. arsenitoxydans aioBA cluster encoding the two subunits of arsenite oxidase is distinct from the other clusters, with two specific genes encoding a cytochrome c and a metalloregulator belonging to the ArsR/SmtB family. These genes are cotranscribed with aioBA, suggesting that these cytochromes c are involved in arsenite oxidation and that this operon is controlled by the metalloregulator. The growth of T. arsenitoxydans in the presence of thiosulfate and arsenite, or arsenate, is biphasic. Real-time PCR experiments showed that the operon is transcribed during the second growth phase in the presence of arsenite or arsenate, whereas antimonite had no effect. These results suggest that the expression of the aioBA operon of T. arsenitoxydans is regulated by the electron donor present in the medium, i.e., is induced in the presence of arsenic but is repressed by more energetic substrates. Our data indicate that the genetic organization and regulation of the aioBA operon of T. arsenitoxydans differ from those of the other arsenite oxidizers.

  12. An assemblage of the host anemone Heteractis magnifica in the northern Res Sea, and distribution of the resident anemonefish

    DEFF Research Database (Denmark)

    Brolund, Thea Marie; Tychsen, Anders; Nielsen, Lis Engdahl;

    2004-01-01

    The Heteractis magni¢ca assemblage at the tip of the Sinai Peninsula was examined. The actinian size, location, and number of resident anemone¢shes were recorded. The anemones were found at depths down to approximately 40m and the sizes of clustering H. magni¢ca and clusters were positively corre...

  13. Progress in Organization and Regulation of Calvin-Benson-Bassham Cycle Genes in Chemoautotrophic Bacteria%化能自养细菌Calvin循环相关基因的组织和调节研究进展

    Institute of Scientific and Technical Information of China (English)

    董微; 李大平

    2006-01-01

    Calvin循环是化能自养细菌同化CO2的主要途径.该循环大多数酶由cbb基因编码.除保守的内在基因排列次序外,不同化能自养细菌cbb基因簇在基因大小和操纵子结构上存在差异.兼性化能自养菌cbb操纵子比专性化能自养菌受到更严格的调控,其调控作用主要由位于cbb操纵子上游编码LysR家族转录激活蛋白的cbbR基因执行.最近的研究表明,另外一些蛋白因子也可能参与cbb基因调控.尽管操纵子调控元件接收到的代谢信号仍是未知的,但一般认为细胞的氧化还原状态起着

  14. Geology of the Alarcón Rise Based on 1-m Resolution Bathymetry and ROV Observations and Sampling

    Science.gov (United States)

    Clague, D. A.; Caress, D. W.; Lundsten, L.; Martin, J. F.; Paduan, J. B.; Portner, R. A.; Bowles, J. A.; Castillo, P. R.; Dreyer, B. M.; Guardado-France, R.; Nieves-Cardoso, C.; Rivera-Huerta, H.; Santa Rosa-del Rio, M.; Spelz-Madero, R.

    2012-12-01

    in two areas within the large sheet flow on the inflated portion of the ridge. Fluid temperatures exceed 300°C and the chimneys are surrounded by extensive vent communities that superficially resemble those at 21°N with robust clumps of Riftia pachyptila and fields of mostly dead Calyptogena magnifica. Samples from some of the inactive chimneys are Cu-rich (abundant chalcopyrite), but most of the 37 chimney and sulfide mound samples are Fe- and Zn-rich. The rims of the two central calderas on Alarcón Seamount are aphyric channelized sheet flows, but the rim on the western and largest caldera is comprised of limu-o Pele rich volcaniclastic deposits. Foraminifera ooze with hydrothermal clay component has accumulated inside the calderas.

  15. Newly discovered hydrothermal system on the Alarcón Rise, Mexico

    Science.gov (United States)

    Paduan, J. B.; Clague, D. A.; Caress, D. W.; Lundsten, L.; Martin, J. F.; Nieves-Cardoso, C.

    2012-12-01

    The Alarcón Rise lies at the mouth of the Gulf of California, and is the last segment of the East Pacific Rise before the plate boundary redirects into the gulf. As part of MBARI's expedition to the gulf in 2012, the neovolcanic zone of the entire ridge segment was mapped by MBARI's mapping AUV. 110 potential hydrothermal chimneys were identified in the new high resolution maps, and 70 were visited with the ROV Doc Ricketts, after having been sought in vain without the maps on an expedition in 2003. Two active vent fields were found, and have been named Meyibó and Ja sít from local native languages. They lie 2.5km apart at ~2300m depth, and are associated with a large, young sheet flow 1/3 of the way along the ridge from the south, on the most inflated part of the ridge. The southern field, Meyibó, contains 14 active chimneys (confirmed with ROV observations) nestled in grabens of several highly fractured cones surrounded by the sheet flow, and generally aligned with its discontinuous, 8km-long fissure system. The northern field, Ja sít, is a broad cluster of 8 active chimneys (also confirmed) rising above the sheet flow's channel system, more than 150m from the fissure. The chimneys stand as tall as 18 m. The most vigorous vent "black smoke" (mineral-rich fluid) >300°C and others are bathed in "white smoke". The active chimneys are populated with bacterial mat and dense clumps of Riftia pachyptila with tubes as long as 1.5m. Abundant limpets, Bythograea thermydron and galatheid crabs, and the pink vent fish Thermarces cerberus were on and near the giant tube worms. Alvinellid worms were observed at 2 chimneys. Some cracks in nearby lava flows vented clear fluid and were populated with tubeworms or Calyptogena magnifica clams. Several chimneys exhibited signs of waning activity: dead tubeworms were still attached and only a minor portion of the edifice supported bacterial mat and live tubeworms. Inactive chimneys are more numerous (48 were confirmed with ROV

  16. Immobilized reactor for rapid destruction of recalcitrant organics and inorganics in tannery wastewater

    Institute of Scientific and Technical Information of China (English)

    A. Ganesh Kumar; G. Sekaran; S. Swarnalatha; B. Prasad Rao

    2005-01-01

    The wastewater discharged from tanneries lack biodegradability due to the presence of recalcitrant compounds at significant concentration. The focal theme of the present investigation was to use chemo-autotrophic activated carbon oxidation(CAACO) reactor, an immobilized cell reactor using chemoautotrophs for the treatment of tannery wastewater. The treatment scheme comprised of anaerobic treatment, sand filtration, and CAACO reactor, which remove COD, BOD, TOC, VFA and sulphides respectively by 86%, 95%, 81%,71% and 100%. Rice bran mesoporous activated carbon prepared indigenously and was used for immobilization of chemoautotrophs. The degradation of xenobiotic compounds by CAACO was confirmed through HPLC and FT-IR techniques.

  17. Distribution Modeling of three screwworm species in the ecologically diverse landscape of North West Pakistan.

    Science.gov (United States)

    Zaidi, Farrah; Fatima, Syeda Hira; Khisroon, Muhammad; Gul, Ayesha

    2016-10-01

    North West Pakistan (NWP) is characterized by four eco-zones: Northern Montane Region, North Western Hills, Submontane Region and Indus Plains. Present study identified 1037 cases of traumatic myiasis in the region during 2012-2015. Screw worm larvae were classified as 12 species: Chrysomya bezziana (Villeneuve), Chryomya megacephala (Fabricius), Chrysomya rufifacies (Macquart), Lucilia cuprina (Wiedemann), Lucilia sericata (Meigen), Lucilia illustris (Meigen), Lucilia porphyrina (Walker), Hemipyrellia ligguriens (Wiedemann), Calliphora vicina (Robineau-Desvoidy), Wohlfahrtia magnifica (Schiner), Sarcophaga crassipalpalis (Macquart), Sarchophaga species. Among these C. bezziana, L. cuprina and W. magnifica with approximately 882 case reports were the principal agents of traumatic myiasis. The species W. magnifica is a first report from Pakistan. In order to investigate spatial distribution of these dominant species we used MaxEnt niche model. Our results revealed a well-established occurrence of C. bezziana and L. cuprina in the four eco-regions while W. magnifica is currently contained in the Submontane Region. Several hot spot areas of infestation were detected all characterized by high human population density showing synanthropic nature of these species. Wohlfahrtia magnifica was excluded from Northern Montane Region with severe winters and Southern Indus Plains with harsh summers revealing that invasive species are initially sensitive to extreme of temperatures. Presence of L. cuprina in the wet areas of North Humid Belt (Maximum annual precipitation: 1641mm) depicted a moisture preference of the species. In perspective of changing climate and future predictions of severe events such as droughts and flooding in NWP, W. magnifica can potentially alter the species composition. Considering these findings in an eco-geographically dynamic region of Pakistan we predict that two factors (1) Growing human population (2) Climatic conditions, equally contribute to range

  18. Uniform designation for genes of the Calvin-Benson-Bassham reductive pentose phosphate pathway of bacteria

    NARCIS (Netherlands)

    Tabita, F. Robert; Gibson, Janet L.; Bowien, Botho; Dijkhuizen, Lubbert; Meijer, Wilhelmus

    1992-01-01

    Structural and regulatory genes encoding enzymes and proteins of the reductive pentose phosphate pathway have been isolated from a number of bacteria recently. In the phototroph Rhodobacter sphaeroides, and in two chemoautotrophic bacteria, Alcaligenes eutrophus and Xanthobacter flavus, these genes

  19. Paracatenula, an ancient symbiosis between thiotrophic Alphaproteobacteria and catenulid flatworms

    OpenAIRE

    Gruber-Vodicka, Harald Ronald; Dirks, Ulrich; Leisch, Nikolaus; Baranyi, Christian; Stoecker, Kilian; Bulgheresi, Silvia; Heindl, Niels Robert; Horn, Matthias; Lott, Christian; Loy, Alexander; Wagner, Michael; Ott, Jörg

    2011-01-01

    Harnessing chemosynthetic symbionts is a recurring evolutionary strategy. Eukaryotes from six phyla as well as one archaeon have acquired chemoautotrophic sulfur-oxidizing bacteria. In contrast to this broad host diversity, known bacterial partners apparently belong to two classes of bacteria—the Gamma- and Epsilonproteobacteria. Here, we characterize the intracellular endosymbionts of the mouthless catenulid flatworm genus Paracatenula as chemoautotrophic sulfur-oxidizing Alphaproteobacteria...

  20. Les pigments respiratoires de la faune inféodée à l'hydrothermalisme océanique profond

    OpenAIRE

    Toulmond, A; Frescheville, J; Frisch, M-h; Jouin, C.

    1988-01-01

    Examples of the two main classes of circulating respiratory pigments (heme pigments and hemocyanins) have been found in four typical members of the deep-sea hydrothermal vent communities. The studies now in progress concern the hemoglobin of Calyptogena ; the erythrocruorins of Alvinella and Riftia ; and the hemocyanin of Bythograea . This paper summarizes the available data of the molecular structure of these pigments and the functional properties allowing some of them to fix and transport o...

  1. Nouvelles espèces d’Orchomene s.l. (Crustacea-Amphipoda) des fonds abyssaux. Affinités avec les autres Orchomene profonds

    NARCIS (Netherlands)

    Bellan-Santini, D.

    1990-01-01

    Deux espèces d’ Orchomene aveugles appartenant aux communautés benthiques abyssales sont décrites. O. kaikoi a été récolté dans le grand bivalve Calyptogena (Ectenagena) phaseoliformis provenant des fosses de subduction du Japon. O. stocki provient du lavage d’épongés du genre Cladorhiza récoltées a

  2. The oldest accurate record of Scenopinidae in the Lowermost Eocene amber of France (Diptera: Brachycera).

    Science.gov (United States)

    Garrouste, Romain; Azar, Dany; Nel, Andre

    2016-03-22

    Eocenotrichia magnifica gen. et sp. nov. (Diptera: Scenopinidae: Metatrichini) is described and illustrated from the Lowermost Eocene amber of Oise (France) and represents the oldest definitive window fly fossil. The present discovery in the Earliest Eocene supports the Late Cretaceous-Paleocene age currently proposed for the emergence of Metatrichini.

  3. 76 FR 31866 - Endangered and Threatened Wildlife and Plants; Reclassification of the Tulotoma Snail From...

    Science.gov (United States)

    2011-06-02

    ...; Reclassification of the Tulotoma Snail From Endangered to Threatened AGENCY: Fish and Wildlife Service, Interior... snail (Tulotoma magnifica) from endangered to threatened, under the authority of the Endangered Species... this snail. DATES: This final rule is effective on July 5, 2011. ADDRESSES: This final rule...

  4. 75 FR 35424 - Endangered and Threatened Wildlife and Plants; Proposed Reclassification of the Tulotoma Snail...

    Science.gov (United States)

    2010-06-22

    ...; Proposed Reclassification of the Tulotoma Snail From Endangered to Threatened AGENCY: Fish and Wildlife...), propose to reclassify the tulotoma snail (Tulotoma magnifica) from endangered to threatened, under the... no longer correctly reflects the status of this snail. We have documented a substantial...

  5. Lg and Other Regional Phases in South America

    Science.gov (United States)

    1990-09-01

    de la Escuela Profesional de- Ingenieria Geofisica de la Universidad National de San Augoistin de Arequipa-PerO, por la magnifica labor desarrollada...fines Gubernamental Flo obstante cualquier derecho de propiedad intelectual. 22 INDICE Ai-IRP(TpFT: I Hi I EN.IOS iCF’ I TI!jLO I T n t r ,-:,duc 1.: i

  6. Oxygen consumption by a coral reef sponge.

    Science.gov (United States)

    Hadas, Eran; Ilan, Micha; Shpigel, Muki

    2008-07-01

    Oxygen consumption of the Red Sea coral reef sponge Negombata magnifica was measured using both incubation and steady-state methods. The latter method was found to be the more reliable because sponge activity remained stable over time. Oxygen consumption rate was measured during three levels of sponge activity: full activity, reduced activity and basal activity (starved). It was found that the active oxygen consumption rate of N. magnifica averaged 37.3+/-4.6 nmol O2 min(-1) g(-1) wet mass, which is within the upper range reported for other tropical marine sponges. Fully active N. magnifica individuals consumed an average of 41.8+/-3.2 nmol O2 min(-1) g(-1) wet mass. The mean basal respiration rate was 20.2+/-1.2 nmol O2 min(-1) g(-1) wet mass, which is 51.6+/-2.5% of the active respiration rate. Therefore, the oxygen used for water pumping was calculated to be at most 10.6+/-1.8 nmol O2 min(-1) g(-1) wet mass, which is 25.1+/-3.6% of the total respiration. Combined oxygen used for maintenance and water pumping activity was calculated to be 30.8 nmol O2 min(-1) g(-1) wet mass, which is approximately 74% of the sponge's total oxygen requirement. The remaining oxygen is directed to other physiological activities, mainly the energy requirement of growth. These findings suggest that only a relatively minor amount of energy is potentially available for growth, and thus might be a factor in controlling the growth rate of N. magnifica in oligotrophic coral reefs.

  7. Analysis of DNA binding and transcriptional activation by the LysR-type transcriptional regulator CbbR of Xanthobacter flavus

    NARCIS (Netherlands)

    van Keulen, G; Ridder, ANJA; Dijkhuizen, L; Meijer, WG; Meijer, Wim G.

    2003-01-01

    The LysR-type transcriptional regulator CbbR controls the expression of the cbb and gap-pgk operons in Xanthobacter flavus, which encode the majority of the enzymes of the Calvin cycle required for autotrophic CO2 fixation. The cbb operon promoter of this chemoautotrophic bacterium contains three po

  8. Immunochemical localization of ribulose-1,5-bisphosphate carboxylase in the symbiont-containing gills of Solemya velum (Bivalvia : Mollusca)

    NARCIS (Netherlands)

    Cavanaugh, Colleen M.; Abbott, Marilyn S.; Veenhuis, Marten

    1988-01-01

    The distribution of the Calvin cycle enzyme ribulose-1,5-bisphosphate carboxylase (RbuP2Case; EC 4.1.1.39) was examined by using two immunological methods in tissues of Solemya velum, an Atlantic coast bivalve containing putative chemoautotrophic symbionts. Antibodies elicited by the purified large

  9. Large Vesicomyidae (Mollusca: Bivalvia) from cold seeps in the Gulf of Guinea off the coasts of Gabon, Congo and northern Angola

    Science.gov (United States)

    von Cosel, Rudo; Olu, Karine

    2009-12-01

    Two new genera and three new species of large Vesicomyidae are described from cold-seep sites on pockmarks and other sulfide-rich environments in the Gulf of Guinea (tropical east Atlantic) off Gabon, Congo (Brazzaville) and northern Angola, from 500 to 4000 m depth: " Calyptogena" (s.l.) regab n. sp., Wareniconcha (n.g.) guineensis (Thiele and Jaeckel 1931), Elenaconcha guiness n.g. n. sp., and Isorropodon atalantae n. sp. For two other species already taken by the R/V Valdivia in 1898, Calyptogena valdiviae (Thiele and Jaeckel 1931) and Isorropodon striatum (Thiele and Jaeckel 1931) new localities were discovered, and the species are rediscussed. E. guiness n.g. n.sp. is also recorded from off Banc d'Arguin, Mauritania, collected by commercial fishing vessels. The vesicomyid species here treated were encountered in different depth ranges along the Gabon-Congo-Angola margin, between 500 and 4000 m depth, and it was found that, in comparison with the dredge samples taken by the Valdivia expedition off southern Cameroon and off Rio de Oro (both at 2500 m), the same species occur in other depth ranges, in some cases with a vertical difference of more than 1000 m. .That means that the species are not confined to a given depth thought being typical for them and that the characteristics of the biotope are likely to play a major role in the distribution of the vesicomyids associated to cold seeps or other reduced environments along the West African margin.

  10. Two possible hydrothermal vents in the northern Oki-nawa Trough

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    As the Okinawa Trough is a back-arc basin in early spreading, modern submarine hydrothermal activity and minerallization have many characteristics which have aroused wide attention. Up to now, three well-known hy-drothermal venting areas are all located in the middle part of the trough. During two cruise investigations to map and sample the seafloor, numbers of Calyptogena sp. shells were dredged at two sites in the northern trough with compara-tively thicker crust and numerous submarine volcanoes. Based on the fact that Calyptogena sp. is only observed around the hydrothermal vents and lives on hydrothermal activities, it is predicted that there is the possibility of mod-ern hydrothermal activities in the northern part of the trough. In this note, the shell is carefully characterized and the sample locations with possible hydrothermal activity are given. It is pointed out that the research of biogenic fossils to trace hydrothermal activity changes in venting time, strength fluctuations, evolution in chemical compositions and so on should be stressed in the future in addition to the study of the ecological characteristics of hydrothermal organisms.

  11. Genetic tools link long-term demographic and life-history traits of anemonefish to their anemone hosts

    Science.gov (United States)

    Salles, Océane C.; Saenz-Agudelo, Pablo; Almany, Glenn R.; Berumen, Michael L.; Thorrold, Simon R.; Jones, Geoffrey P.; Planes, Serge

    2016-12-01

    The life-history traits and population dynamics of species are increasingly being attributed to the characteristics of their preferred habitats. While coral reef fish are often strongly associated with particular habitats, long-term studies establishing the demographic and life-history consequences of occupying different reef substrata are rare and no studies have monitored individuals in situ over their lifetime and determined the fate of their offspring. Here, we documented a quasi-turnover and local reproductive success for an entire population of orange clownfish ( Amphiprion percula) from Kimbe Island, Papua New Guinea, by taking bi-annual samples of DNA over a 10-yr period (2003-2013). We compared demographic and life-history traits of individuals living on two host anemone species, Heteractis magnifica and Stichodactyla gigantea, including female size, adult continued presence (a proxy for relative longevity range), early post-settlement growth, the number of eggs per clutch and `local' reproductive success (defined for each adult as the number of offspring returning to the natal population). Our results indicate that while the relative longevity of adults was similar on both host anemone species, females living in H. magnifica were larger than females in S. gigantea. However, despite females growing larger and producing more eggs on H. magnifica, we found that local reproductive success was significantly higher for clownfish living in S. gigantea. Life-history traits also exhibited local spatial variation, with higher local reproductive success recorded for adults living on S. gigantea on the eastern side of the island. Our findings support a `silver-spoon' hypothesis that predicts individuals that are fortunate enough to recruit into good habitat and location will be rewarded with higher long-term reproductive success and will make a disproportionate contribution to population renewal.

  12. Pharmacological and biomedical properties of sea anemones Paracondactylis indicus, Paracondactylis sinensis, Heteractis magnificaand Stichodactyla haddonifrom East coast of India

    Institute of Scientific and Technical Information of China (English)

    Bragadeeswaran Subramanian; Thangaraj Sangappellai; Rajiv Chandra Rajak; Balaji Diraviam

    2011-01-01

    Objective:To explore the biomedical and pharmacological activity ofParacondactylis indicus (P. indicus),Paracondactylis sinensis(P. sinensis),Heteractis magnifica (H. magnifica) and Stichodactyla haddoni (S. haddoni).Methods: The live sea anemones were kept inside the glass bowl along with some amount of distilled water in an ice container for15 min. During stress condition, nematocysts released from the tentacles were collected and centrifuged at5 000 rpm for 15 min. The supernatant were collected in separate cleaned beakers for lyophilisation.Results:The protein content of crude extracts was15.2, 28.7, 18.2 and35.4μg/mL. In hemolytic assay, the P. indicus was sensitive (16.842 HT/mg) on chicken blood butP. sinensis was less sensitive (1.114 HT/mg) on chicken and goat blood. WhereasH. magnificaandS. haddoni showed hemolysis (0.879, 0.903 HT/mg and 56.263, 0.451 HT/mg) in chicken and goat blood. In antimicrobial assay, the methanol extract ofP. indicus showed maximum inhibition zone of9.7mm againstS. typhii andP. sinensisshowed9.8 mm againstK. pneumonia in methanol and ethanol extracts. Whereas theH. magnifica andS. haddoni showed maximum of10 mm againstS. typhii, K. pneumonia in methanol and ethanol extracts.Conclusions: The high toxic sea anemones may also contain some biologically active agents which has haemolytic, analgesic and anti-infilamatory activity.

  13. Genetic tools link long-term demographic and life-history traits of anemonefish to their anemone hosts

    KAUST Repository

    Salles, Océane C.

    2016-07-26

    The life-history traits and population dynamics of species are increasingly being attributed to the characteristics of their preferred habitats. While coral reef fish are often strongly associated with particular habitats, long-term studies establishing the demographic and life-history consequences of occupying different reef substrata are rare and no studies have monitored individuals in situ over their lifetime and determined the fate of their offspring. Here, we documented a quasi-turnover and local reproductive success for an entire population of orange clownfish (Amphiprion percula) from Kimbe Island, Papua New Guinea, by taking bi-annual samples of DNA over a 10-yr period (2003–2013). We compared demographic and life-history traits of individuals living on two host anemone species, Heteractis magnifica and Stichodactyla gigantea, including female size, adult continued presence (a proxy for relative longevity range), early post-settlement growth, the number of eggs per clutch and ‘local’ reproductive success (defined for each adult as the number of offspring returning to the natal population). Our results indicate that while the relative longevity of adults was similar on both host anemone species, females living in H. magnifica were larger than females in S. gigantea. However, despite females growing larger and producing more eggs on H. magnifica, we found that local reproductive success was significantly higher for clownfish living in S. gigantea. Life-history traits also exhibited local spatial variation, with higher local reproductive success recorded for adults living on S. gigantea on the eastern side of the island. Our findings support a ‘silver-spoon’ hypothesis that predicts individuals that are fortunate enough to recruit into good habitat and location will be rewarded with higher long-term reproductive success and will make a disproportionate contribution to population renewal. © 2016 Springer-Verlag Berlin Heidelberg

  14. Notas, novos registros e novas espécies da coleção de Cerambycidae (Coleoptera do Instituto Nacional de Pesquisas da Amazônia, Manaus

    Directory of Open Access Journals (Sweden)

    Maria Helena M. Galileo

    2011-09-01

    Full Text Available Espécies novas descritas da Amazônia brasileira em Ibidionini: Compsibidion uniforme sp. nov. (Amazonas; Heterachthes rafaeli sp. nov. (Amazonas; em Apomecynini: Amphicnaeia lineolata sp. nov. (Pará; em Desmiphorini: Cotycicuiara magnifica sp. nov. (Amazonas. Novos registros e notas são apresentados para: Gnomidolon insulicola Bates, 1885 e G. lansbergei (Thomson, 1867 (Hexoplonini; Desmiphora (D. uniformis Galileo & Martins, 2003 (Desmiphorini; Omosarotes paradoxum (Tippmann, 1955 (Cyrtinini e Ozotroctes ogeri Tavakilian & Néouze, 2007 (Acanthoderini.

  15. New species of Anthostomella on fynbos, with a key to the genus in South Africa.

    Science.gov (United States)

    Lee, Seonju; Crous, Pedro W

    2003-03-01

    A study of saprobic fungi occurring on the fynbos of the Western Cape Province of South Africa yielded four unknown Anthostomella species. A. proteae from Protea nitida, A. cynaroides from P. cynaroides, A. leucospermi from Leucospermum oleifolium, and A. brabeji from Brabejum stellatifolium are described as new. New records for South Africa include A. conorum from Leucadendron sp., Protea magnifica and P. neriifolia, and A. clypeata from Ischyrolepis subverticellata, Cannomois virgata, Restio egregius, and R. cfr confusus. A dichotomous key to the Anthostomella species in South Africa is also provided.

  16. Indigènes

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    María Eugenia Albornoz Vásquez

    2007-06-01

    Full Text Available El insomnio visito implacable mi noche después de ver esta magnifica y valiente película. El ahogo de los sueños y la manipulación de la esperanza a través del riesgo de la vida y el desangramiento de las mejores cualidades que se poseen es una de las realidades que, sin un ápice de religiosidad fanática, debieran catalogarse de pecado capital y de crimen contra la humanidad. Debiera haber un tribunal que identifique y juzgue la manipulación y la usura que se ha hecho, se hace y seguramente ...

  17. Juvenile Thalassoma amblycephalum Bleeker (Labridae, Teleostei) dwelling among the tentacles of sea anemones

    DEFF Research Database (Denmark)

    Arvedlund, Michael; Iwao, Kenji; Brolund, Thea Marie

    2006-01-01

    each) of the juvenile wrasse Thalassoma amblycephalum dwelling among the tentacles of the two sea anemones Entacmaea quadricolor (clonal type), and Heteractis magnifica at a coral reef in southern Japan during 16 months in daylight hours. There are only two past records of this facultative association......, one from east Africa and one from Indonesia. The wrasse remained close to and was occasionally in physical contact with the host when foraging amongst the tentacles. When frightened, they took shelter among corals, away from the host anemone. The wrasse co-existed with the anemonefishes Amphiprion...

  18. Transcriptional Response of the Archaeal Ammonia Oxidizer Nitrosopumilus maritimus to Low and Environmentally Relevant Ammonia Concentrations

    OpenAIRE

    Nakagawa, Tatsunori; Stahl, David A.

    2013-01-01

    The ability of chemoautotrophic ammonia-oxidizing archaea to compete for ammonia among marine microorganisms at low ambient concentrations has been in part attributed to their extremely high affinity for ammonia, but as yet there is no mechanistic understanding of supporting metabolism. We examined transcription of selected genes for anabolic functions (CO2 fixation, ammonia transport, and cell wall synthesis) and a central catabolic function (ammonia oxidation) in the thaumarchaeon Nitrosopu...

  19. Paracatenula, an ancient symbiosis between thiotrophic Alphaproteobacteria and catenulid flatworms.

    Science.gov (United States)

    Gruber-Vodicka, Harald Ronald; Dirks, Ulrich; Leisch, Nikolaus; Baranyi, Christian; Stoecker, Kilian; Bulgheresi, Silvia; Heindl, Niels Robert; Horn, Matthias; Lott, Christian; Loy, Alexander; Wagner, Michael; Ott, Jörg

    2011-07-19

    Harnessing chemosynthetic symbionts is a recurring evolutionary strategy. Eukaryotes from six phyla as well as one archaeon have acquired chemoautotrophic sulfur-oxidizing bacteria. In contrast to this broad host diversity, known bacterial partners apparently belong to two classes of bacteria--the Gamma- and Epsilonproteobacteria. Here, we characterize the intracellular endosymbionts of the mouthless catenulid flatworm genus Paracatenula as chemoautotrophic sulfur-oxidizing Alphaproteobacteria. The symbionts of Paracatenula galateia are provisionally classified as "Candidatus Riegeria galateiae" based on 16S ribosomal RNA sequencing confirmed by fluorescence in situ hybridization together with functional gene and sulfur metabolite evidence. 16S rRNA gene phylogenetic analysis shows that all 16 Paracatenula species examined harbor host species-specific intracellular Candidatus Riegeria bacteria that form a monophyletic group within the order Rhodospirillales. Comparing host and symbiont phylogenies reveals strict cocladogenesis and points to vertical transmission of the symbionts. Between 33% and 50% of the body volume of the various worm species is composed of bacterial symbionts, by far the highest proportion among all known endosymbiotic associations between bacteria and metazoans. This symbiosis, which likely originated more than 500 Mya during the early evolution of flatworms, is the oldest known animal-chemoautotrophic bacteria association. The distant phylogenetic position of the symbionts compared with other mutualistic or parasitic Alphaproteobacteria promises to illuminate the common genetic predispositions that have allowed several members of this class to successfully colonize eukaryote cells.

  20. Seismic observed structure of Natsushima 86-2 knoll in Iheya small-ridges of mid-Okinawa Trough, Japan

    Science.gov (United States)

    Ikegami, Fumihiko; Tsuji, Takeshi; Kumagai, Hidenori; Takai, Ken

    2013-04-01

    Iheya small ridges are the group of the ENE-WSW elongated rod-shaped knolls at the central axis of mid-Okinawa trough back-arc extensional basin. The basin has been actively stretching more than 1000 km long at 250 km west of the convergent boundary between Philippine oceanic lithosphere and Eurasian continental counterpart since ~2 Ma (Hsu et al., 2001). Natsushima 86-2 knoll is the westernmost one of the Iheya small ridges which height is 600 m from the 1600 m depth seafloor. Multiple hydrothermal sites have been reported for these 25 years in the mid-Okinawa Trough region while previously well-studied Calyptogena site (Tanaka et al., 1989; Gamo et al., 1991) is just at the northeastern extension of the knoll. Five profiles of single-channel seismic reflection survey were obtained in Natsushima 86-2 knoll during YK-12-16 cruise in order to find structure controlling hydrothermal activity. Every profile makes the cross-section of the knoll. The source of the reflection was 150 cubic inches G-I gun with 10 seconds interval. As a result of the interpretation for seismic profiles, it is fair to conclude that the knoll has possible volcanic origin and relatively new structure. Natsushima 86-2 knoll is positioned on the normal faulted stratified deposits which are dipping from the both sides of the knoll. The surface of the knoll shows mostly low amplitude reflection which can be interpreted as pumices or other high porosity materials which is consistent with the past dredging retrieval by Kimura et al. (1987). Bend and fading of the stratified reflection approximately 100 m beneath the Calyptogena site indicates shallow intrusion of magmatic body has responsible with the formation of the hydrothermal site.

  1. Notas e novas espécies de Onciderini (Coleoptera, Cerambycidae, Lamiinae

    Directory of Open Access Journals (Sweden)

    Ubirajara R. Martins

    2007-01-01

    Full Text Available Novas espécies descritas do Brasil: Hypsioma carioca sp. nov. (Rio de Janeiro e Hesychotypa maraba sp. nov. (Pará; do Equador: Sternycha ecuatoriana sp. nov. (Pichincha; da Bolívia (Santa Cruz: Hesychotypa magnifica sp. nov., Tibiosioma maculosa sp. nov. e Alexera secunda sp. nov. Transfere-se Hesycha strandi (Breuning, 1943 para o gênero Cacostola Fairmaire & Germain, 1859. Hesychotypa archippa Dillon & Dillon, 1946 é considerada sinônima de H. miniata Thomson, 1868. Novo registro (Trinidad e figura são dados para Trachysomus surdus.Notes and new species of Onciderini (Coleoptera, Cerambycidae, Lamiinae. New species described from Brazil: Hypsioma carioca sp. nov. (Rio de Janeiro and Hesychotypa maraba sp. nov. (Pará; from Ecuador: Sternycha ecuatoriana sp. nov. (Pichincha; from Bolivia (Santa Cruz: Hesychotypa magnifica sp. nov., Tibiosioma maculosa sp. nov. and Alexera secunda sp. nov. Hesycha strandi (Breuning, 1943 is transferred to the genus Cacostola Fairmaire & Germain, 1859. Hesychotypa archippa Dillon & Dillon, 1946 is considered a synonym of H. miniata Thomson, 1868. New record (Trinidad and figure for Trachysomus surdus Dillon & Dillon, 1946 are given.

  2. Genetic divergence of four Dioryctria species from North China%华北地区四种梢斑螟的遗传分化

    Institute of Scientific and Technical Information of China (English)

    于潇翡; 杜艳丽; 刘永杰; 张民照; 张涛

    2009-01-01

    The phylogenesis of 9 geographical populations from 4 Dioryctria species, D. rubella Hatnpson, D . yiai Mutuura & Munroe, D . magnifica Munroe and D. abietella Denis & Schiffermuller were investigated based on CO Ⅰ sequences, with Oncocera faecella (Zeller) as outgroup. The genetic distances and phylogenetic tree revealed that: (1) the 4 Dioryctria species could be grouped into 2 clades. D. rubella and D. magnifica were clustered as one group, while D. yiai and D. abietella were clustered as the other; (2) the genetic distances between the geographical populations were 0.000 - 0.016, significantly less than those between the species (0.029 - 0.089) , which indicated that CO Ⅰ sequences may be suitable for determining the phylogenetic relationships of Dioryctria species.%根据线粒体COⅠ基因序列,对华北地区梢斑螟属Dioryctria Zeller的微红梢斑螟D. rubella Hampson、芽梢斑螟D. yiai Mutuura & Munroe、大梢斑螟D. magnifica Munroe和冷杉梢斑螟D. abietella Denis & Schiffermüller共4种,9个不同地理种群进行遗传多样性研究,并以同族的渣云翅斑螟Oncocera faecella (Zeller)为外群探讨它们之间的系统发育关系.结果表明:(1)微红梢斑螟和大梢斑螟的亲缘关系较近,与芽梢斑螟和冷杉梢斑螟构成的姐妹群分别形成华北地区梢斑螟属的两大支系;(2)种内不同地理种群间的遗传距离(0.000~0.016)明显小于种间遗传距离(0.029~0.089),说明利用线粒体COⅠ基因序列研究梢斑螟属昆虫的系统发育关系是可行的.

  3. Extracellular and mixotrophic symbiosis in the whale-fall mussel Adipicola pacifica: a trend in evolution from extra- to intracellular symbiosis.

    Directory of Open Access Journals (Sweden)

    Yoshihiro Fujiwara

    Full Text Available BACKGROUND: Deep-sea mussels harboring chemoautotrophic symbionts from hydrothermal vents and seeps are assumed to have evolved from shallow-water asymbiotic relatives by way of biogenic reducing environments such as sunken wood and whale falls. Such symbiotic associations have been well characterized in mussels collected from vents, seeps and sunken wood but in only a few from whale falls. METHODOLOGY/PRINCIPAL FINDING: Here we report symbioses in the gill tissues of two mussels, Adipicola crypta and Adipicola pacifica, collected from whale-falls on the continental shelf in the northwestern Pacific. The molecular, morphological and stable isotopic characteristics of bacterial symbionts were analyzed. A single phylotype of thioautotrophic bacteria was found in A. crypta gill tissue and two distinct phylotypes of bacteria (referred to as Symbiont A and Symbiont C in A. pacifica. Symbiont A and the A. crypta symbiont were affiliated with thioautotrophic symbionts of bathymodiolin mussels from deep-sea reducing environments, while Symbiont C was closely related to free-living heterotrophic bacteria. The symbionts in A. crypta were intracellular within epithelial cells of the apical region of the gills and were extracellular in A. pacifica. No spatial partitioning was observed between the two phylotypes in A. pacifica in fluorescence in situ hybridization experiments. Stable isotopic analyses of carbon and sulfur indicated the chemoautotrophic nature of A. crypta and mixotrophic nature of A. pacifica. Molecular phylogenetic analyses of the host mussels showed that A. crypta constituted a monophyletic clade with other intracellular symbiotic (endosymbiotic mussels and that A. pacifica was the sister group of all endosymbiotic mussels. CONCLUSIONS/SIGNIFICANCE: These results strongly suggest that the symbiosis in A. pacifica is at an earlier stage in evolution than other endosymbiotic mussels. Whale falls and other modern biogenic reducing

  4. LEVANTAMENTO POPULACIONAL E ANÁLISE FAUNÍSTICA DE LEPIDOPTERA EM Eucalyptus spp. NO MUNICÍPIO DE PINHEIRO MACHADO, RS

    Directory of Open Access Journals (Sweden)

    Oderlei Bernardi

    2011-01-01

    Full Text Available The objective of this research was to collect, to study and to characterize the fauna of lepidopterous associated with Eucalyptus spp., plantation in the Municipality of Pinheiro Machado, in RS state. In the period of October 2005 to October 2007, every 15 days, collections of insects were accomplished with three light traps. After selection and transfixion procedures, the lepidopterous were identified based on entomological collections and specialized literature. Two thousand and twenty individuals belonging to 14 families, 106 genera and 220 species were collected. The families with the highest number of species collected were: Noctuidae (59, Geometridae (30, Arctiidae (28 and Saturniidae (14. According to the fauna classification the most species were considered not dominant, uncommon, rare and accidental. Among the species identified, there were some whose larvae are defoliators of the eucalypts: Oxydia agliata, (Geometridae, Sarsina violascens (Lymantriidae, Automeris illustris, Eacles imperialis magnifica and Lonomia obliqua (Saturniidae, which needs to have their populations monitored.

  5. "pruebas de laboratorio"

    Directory of Open Access Journals (Sweden)

    Manuel Rodríguez

    2007-01-01

    Full Text Available Se exponen los resultados de evaluaciones de laboratorio y del miniaspersor MAMKAD 2255 con boquilla roja, como posible alternativa para el riego de alta frecuencia, baja intensidad y subfoliar en el cultivo del banano. En estas condiciones a 200 kPa de carga, el caudal del miniaspersor fue de 216 L/h, el radio efectivo de 7,8 m y el más alto coeficiente de uniformidad de Christiansen fue de 80,6 % y se obtuvo en el marco de puesta de 9 m entre laterales y 9 m entre miniaspersores, lo que hace de este miniaspersor una alternativa con magnificas características técnicas para el riego del banano plantado en marcos de triángulo equilátero.

  6. Termoterapia transpupilar como opção terapêutica para hemangioma circunscrito de coróide: relato de caso

    Directory of Open Access Journals (Sweden)

    Roizenblatt Jaime

    2002-01-01

    Full Text Available Os autores descrevem um caso de hemangioma circunscrito de coróide, com descolamento de retina associado, tratado por meio de termoterapia transpupilar com laser de diodo. Os parâmetros utilizados foram: 900 mW, mira de 4,2 mm, tempo de 3 minutos, lente QuadrAspheric (Volkâ com fator de magnificação de 1,97. Um mês após o tratamento ocorreu redução significativa do hemangioma, com recuperação integral da visão deste olho. São feitas considerações a respeito do método, o qual mostra-se promissor no tratamento destes tumores vasculares.

  7. New Middle Permian palaeopteran insects from Lodève Basin in southern France (Ephemeroptera, Diaphanopterodea, Megasecoptera

    Directory of Open Access Journals (Sweden)

    Jakub Prokop

    2011-09-01

    Full Text Available Three new palaeopteran insects are described from the Middle Permian (Guadalupian of Salagou Formation in the Lodève Basin (South of France, viz. the diaphanopterodean Alexrasnitsyniidae fam. n., based on Alexrasnitsynia permiana gen. et sp. n., the Parelmoidae Permelmoa magnifica gen. et sp. n., and Lodevohymen lapeyriei gen. et sp. n. (in Megasecoptera or Diaphanopterodea, family undetermined. In addition the first record of mayflies attributed to family Syntonopteridae (Ephemeroptera is reported. These new fossils clearly demonstrate that the present knowledge of the Permian insects remains very incomplete. They also confirm that the Lodève entomofauna was highly diverse providing links to other Permian localities and also rather unique, with several families still not recorded in other contemporaneous outcrops.

  8. Pollen morphology of Vochysiaceae tree species in the State of Santa Catarina, Southern Brazil.

    Science.gov (United States)

    Barth, Ortrud Monika; Pinto Da Luz, Cynthia Fernandes

    2014-09-01

    Tropical Vochysiaceae includes mainly trees, and also shrubs and subshrubs. Three genera and seven species are present in the Brazilian state of Santa Catarina. The pollen morphology of six species of trees, belonging to three genera of the Vochysiaceae A. St-Hil. family, was studied. Herbaria samples were obtained, processed and treated by standard methods. The pollen grain morphology of Callisthene, Qualea and Vochysia is distinct. Medium sized pollen grains occur in Vochysia species, and small ones in Callisthene and Qualea. Specific characteristics were considered at species level [C. castellanosii H. F. Martins, C. kuhlmannii H. F. Martins, Qualea cordata Spreng var. cordata, Q. cryptantha (Spreng) Warm. var. cryptantha, Vochysia magnifica Warm. and V. tucanorum Mart.]. The presence ofa fastigium (vestibulum) and a thin space devoid of nexine fixing the boundary of the apertural area is characteristic of Qualea and Vochysia species only.

  9. La tragedia de Carrizales, "El celoso extremeño"

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    Stanislav Zimic

    1991-12-01

    Full Text Available Muchos lectores píensan que El celoso extremeño es »de una perfección técnica maravillosa ..., cumbre de la novela corta«, lo cual »ha sido sin duda la causa de que 'los críticos, con tesonero empeño, se hayan encarnizado en buscarle analogías, precedentes e influencias de otras obras que puedan explicarnos hoy su excelencia y maestria«. Resulta oportuno hacer una breve re­ seña de estas fuentes o antecedentes literarios, mitológicos, folklóricos, biblicos ...,  propuestos hasta ahora, para enjuiciar mejor otras posibles inspiraciones significativas que se sugieren en nuestro estudio, todo como fondo para un análisis quizás mas fructífero de esta magnifica obra cervantina.

  10. The Carboxysome and Other Bacterial Microcompartments

    Energy Technology Data Exchange (ETDEWEB)

    Kerfeld, Cheryl A.; Greenleaf, William B.; Kinney, James N.

    2010-06-23

    - Carboxysomes are part of the carbon concentrating mechanism in cyanobacteria and chemoautotrophs. - Carboxysomes are a subclass of bacterial microcompartments (BMCs); BMCs can encapsulate a range of metabolic processes. - Like some viral particles, the carboxysome can be modeled as an icosahedron-in its case, having 4,000-5,000 hexameric shell subunits and 12 surface pentamers to generate curvature. - The threefold axis of symmetry of the CsoS1D protein in carboxysomes forms a pore that can open and close, allowing for selective diffusion. - Genetic modules encoding BMC shell proteins and the enzymes that they encapsulate are horizontally transferable, suggesting they enable bacteria to adapt to diverse environments.

  11. Microorganisms in Lianxian lateritic gold deposit in Guangdong and their effects on leaching of heavy metals

    Institute of Scientific and Technical Information of China (English)

    CHEN Binghui; LIU Huhu; WU Fuhai; XU Wenlie

    2005-01-01

    Microorganisms in the lateritic profiles of the Lianxian gold deposit in Guangdong were cultured, isolated and identified. The microorganisms include bacteria such as Bacillus, Enterobacter, Pseudomonas, Lactobacillus, Actinetobacter, Aeromona, Listeria, Agrobacterium, Corynebacterium, and Moraxella, fungi such as Penicillium, Alternaria, Cladosporium, Saccharcomyces, Mucor, and the chemoautotrophic Thiobacillus. It is shown in a leaching experiment that the microorganisms can accelerate the leaching of Cu, Cd, Zn, and that the G - bacteria are most efficient for leaching Cu, Zn and the G + bacteria are better for leaching Cd.

  12. Archaeal remains dominate marine organic matter from the early Albian oceanic anoxic event 1b

    DEFF Research Database (Denmark)

    Kuypers, M.M.M.; Blokker, P.; Hopmans, E.C.;

    2002-01-01

    tetraethers) indicates an important contribution of representatives of marine planktonic archaea. The large difference (up to 12 ‰) in C/C ratios between algal biomarkers and the much more abundant planktonic archaea-derived biomarkers indicates that the latter were living chemoautotrophically. This offset......, distinct lamination, C-enrichment of OC) between the black shales of OAE1b and the Cenomanian/Turonian (∼94 Myr) OAE, the origin of the organic matter (archaeal versus phytoplanktonic) and causes for C-enrichment of OC are completely different. © 2002 Elsevier Science B.V. All rights reserved....

  13. Particulate organic matter as a food source for a coral reef sponge.

    Science.gov (United States)

    Hadas, E; Shpigel, M; Ilan, M

    2009-11-01

    The ability of sponges to feed in diverse (including oligotrophic) ecosystems significantly contributes to their ubiquitous aquatic distribution. It was hypothesized that sponges that harbour small amounts of symbiotic bacteria in their mass feed mainly on particulate organic matter (POM). We examined the nearly symbiont-free (by microscopic observation) filter-feeding Red Sea sponge Negombata magnifica in order to: (a) study removal efficiency of naturally occurring organic particles, (b) measure the total amount of absorbed particulate organic carbon (POC) and nitrogen (PON), and (c) estimate organic carbon and nitrogen flux in this sponge. Total amount of organic carbon and nitrogen in the Gulf of Aqaba was found to be 48.46+/-5.69 microg l(-1) and 6.45+/-0.7 microg l(-1), respectively. While detritus contributed 54% of POC, most PON (84%) came from planktonic microorganisms, mainly prokaryotes. Particle removal efficiency ranged from 99% (the cyanobacterium Synechococcus sp.) to 37% (for eukaryotic cells >8 microm). On average, N. magnifica ingested 480 microg C day(-1) g(-1) (wet mass, WM) sponge and 76.6 microg N day(-1) g(-1) sponge. Ingested POC balanced 85% of the sponge's energetic demand but more is needed for biomass production because it cannot digest all of the carbon. 54.4+/-16.1 microg N day(-1) g(-1) (WM) nitrogen was excreted as total ammonia nitrogen (TAN); however, nitrogen allowance should be higher because more nitrogen is deposited for sponge biomass during growth. It is hypothesized that the discrepancy in the nutritional requirements should be covered by the sponge absorbing carbon and nitrogen from sources that are not dealt with in the present research, such as dissolved organic carbon and nitrogen. This study highlights the significance of detritus as a carbon source, and prokaryotes as a PON source in sponge feeding.

  14. Auto- and heterotrophic acidophilic bacteria enhance the bioremediation efficiency of sediments contaminated by heavy metals.

    Science.gov (United States)

    Beolchini, Francesca; Dell'Anno, Antonio; De Propris, Luciano; Ubaldini, Stefano; Cerrone, Federico; Danovaro, Roberto

    2009-03-01

    This study deals with bioremediation treatments of dredged sediments contaminated by heavy metals based on the bioaugmentation of different bacterial strains. The efficiency of the following bacterial consortia was compared: (i) acidophilic chemoautotrophic, Fe/S-oxidising bacteria, (ii) acidophilic heterotrophic bacteria able to reduce Fe/Mn fraction, co-respiring oxygen and ferric iron and (iii) the chemoautotrophic and heterotrophic bacteria reported above, pooled together, as it was hypothesised that the two strains could cooperate through a mutual substrate supply. The effect of the bioremediation treatment based on the bioaugmentation of Fe/S-oxidising strains alone was similar to the one based only on Fe-reducing bacteria, and resulted in heavy-metal extraction yields typically ranging from 40% to 50%. The efficiency of the process based only upon autotrophic bacteria was limited by sulphur availability. However, when the treatment was based on the addition of Fe-reducing bacteria and the Fe/S oxidizing bacteria together, their growth rates and efficiency in mobilising heavy metals increased significantly, reaching extraction yields >90% for Cu, Cd, Hg and Zn. The additional advantage of the new bioaugmentation approach proposed here is that it is independent from the availability of sulphur. These results open new perspectives for the bioremediation technology for the removal of heavy metals from highly contaminated sediments.

  15. Infaunal and megafaunal benthic community structure associated with cold seeps at the Vestnesa Ridge (79 N°)

    Science.gov (United States)

    Åström, Emmelie K. L.; Carroll, Michael L.; Sen, Arunima; Ambrose, William G., Jr.; Silyakova, Anna; Carroll, JoLynn

    2016-04-01

    Cold seeps are locations where hydrocarbons, sulfide or reduced compounds emanate from the seafloor, which may fuel chemoautotrophic production and form additional hard bottom substrate through carbonate precipitation. Chemosynthetic symbiosis, trophic interactions, and additional bottom substrate types can provide a heterogeneous environment for deep-sea organisms supporting macrofaunal communities including increased biodiversity and biomass. We combined quantitative benthic faunal samples with sea floor photographs from an active, methane seeping pockmark at Vestnesa Ridge (1200 meters depth) to examine community structure and biodiversity in a high Arctic deep cold seep. Quantitative data were compared with samples from the nearby inactive Svyatogor Ridge (1577-1706 meters depth). We measured highly elevated methane concentrations (up to 100x background levels) in the sediment at Vestnesa Ridge. Faunal abundance, species richness and biomass were significantly higher at the Vestnesa pockmark compared to inactive Svyatogor Ridge. Seabed photos from Vestnesa Ridge reveal high megafaunal diversity and biomass and cold seep features including carbonate crust and microbial mats. Our observations indicate that chemoautotrophic production enhances deep-sea biomass and diversity at Vestnesa Ridge. The focused methane emissions create a heterogeneous deep-sea habitat for chemo-associated organisms coexisting with heterotrophic conventional fauna in a high Arctic seep. Keywords: Arctic, benthic ecology, biodiversity, chemosynthesis, methane

  16. Methanotrophy and chemoautotrophy within the redox gradient of a large and deep tropical lake (Lake Kivu, East Africa)

    Science.gov (United States)

    Morana, Cedric; Borges, Alberto V.; Darchambeau, François; Roland, Fleur; Montante, Laetitia; Descy, Jean-Pierre; Bouillon, Steven

    2014-05-01

    Lake Kivu (East Africa) is a large (2370 km2) and deep (maximum depth of 485 m) meromictic lake. Its vertical structure consists of an oxic and nutrient-poor mixed layer down to 70 m maximum, and a permanently anoxic monimolimnion rich in dissolved gases (methane and carbon dioxide) and inorganic nutrients. Seasonal variation of the vertical position of the oxic-anoxic interface is driven by contrasting precipitation and wind speed regimes between rainy (October-May) and dry (June-September) season, the latter being characterized by a deepening of the oxic zone, and an increased input of dissolved gases and inorganic nutrients. Our work aimed at quantifying methanotrophic and chemoautotrophic production within the redox gradient of Lake Kivu and identifying the micro-organisms involved in these processes using phospholipid-derived fatty acid markers and their carbon stable isotope composition. Our approach combined both natural stable isotope abundance analysis and 13C-labelling (13C-DIC ; 13C-CH4) experiments. Sampling was carried out at two stations in Lake Kivu during rainy (February 2012) and dry (September 2012) season conditions. Methanotrophic bacterial production rates were highly variable (from 0.1 to 7.0 μmol C L-1 d-1), but maximum values were always observed at the oxic-anoxic interface when the CH4:O2 ratio varied between 0.1 and 10, suggesting that the majority of methane was oxidized aerobically. Furthermore, strong stable isotope labelling of monounsaturated C16 fatty acids indicate that active methane oxidizers were related to the group of type I aerobic methanotrophs (gammaproteobacteria). Despite the dominance of aerobic methane oxidation, significant methanotrophic bacterial production rates were found below the oxic-anoxic interface during the rainy season, indicating that at least a fraction of the upcoming methane may be oxidized anaerobically. This observation was further confirmed by the strong labelling at these depths of the 10Me16

  17. Cryptic species of deep-sea clams (Mollusca: Bivalvia: Vesicomyidae) from hydrothermal vent and cold-water seep environments

    Science.gov (United States)

    Vrijenhoek, Robert C.; Schutz, Steven J.; Gustafson, Richard G.; Lutz, Richard A.

    1994-08-01

    A protein-electrophoretic analysis of six putative morphospecies in the bivalve family Vesicomyidae from eight deep-sea hydrothermal vent sites in the eastern Pacific, three cold-water seep sites in the eastern Pacific and the Gulf of Mexico, and one whale-carcass site off Southern California revealed electromorph patterns diagnostic of 10 vesicomyid species. Electrophoretic patterns for 14 enzymes encoded by 17 presumptive gene loci were scored in all 10 species. The pairwise genetic distances (Nei's D) for these 10 species ranged from 0.857 to 2.792, values within the range expected for distinct species and genera. However, the degree of genetic divergence among these taxa could not be used for phylogenetic inferences because allozyme differences had in many cases reached evolutionary saturation. Notwithstanding, the present results revealed a significant problem with current morphospecies identifications of these clams and with applications of the current generic names Calyptogena and Vesicomya. Given the cryptic nature of these taxa, we suggest that subsequent studies simply refer to these clams as "vesicomyids" until careful morphological analyses and molecular studies are completed and systematic relationships are clarified.

  18. Tectonic features of out-of-sequence-thrusts in central Nankai accretionary prism

    Science.gov (United States)

    Saito, S.; Kuramoto, S.; Ashi, J.; Kinoshita, M.; Ujiie, K.; Sagaguchi, A.; Lallemant, S.; Toki, T.; Kubo, Y.; Misawa, N.

    2002-12-01

    During NT02-02 and YK02-02 cruises, deep-tow camera, multi-beam bathymetry, and diving survey were conducted in central Nankai accretionary prism, off Kii Peninsula. A system of out-of-sequence thrusts (OOST) defines high ridges, roughly parallel to the deformation front. The surface manifestation of the OOST is characterized by right-stepped en-echelon arrangement of ridges, which suggests a dextral slip component along the OOST. A series of deep-tow camera and dive surveys were conducted on the sites of OOST. Observation of outcrops and rock-sampling documented that the ridges are composed dominantly of stratified shale, siltstone and partly of sandstone covered by present talus debris and clayey ooze. Exposures along the southern limb of the ridges indicate that the beddings of the sediments dip generally northwestward at an angle of about 20 to 30 degree. In contrast to the southern limb of the ridge, outcrops along the northern limb of the ridge show southward dipping bedding. Active cold seepages with Calyptogena colony, bacteria mat, and carbonate chimney were observed at several sites on the slope of OOST ridges. All the active cold seepages observed from the submersible are located on the gentle foot of the slope. High heat flow, low chlorinity of interstitial water chemistry, and high natural gamma radiation at the active colony suggests seepage from the inside of the basement.

  19. Physiological ecology of microorganisms in Subglacial Lake Whillans

    Directory of Open Access Journals (Sweden)

    Trista J Vick-Majors

    2016-10-01

    Full Text Available Subglacial microbial habitats are widespread in glaciated regions of our planet. Some of these environments have been isolated from the atmosphere and from sunlight for many thousands of years. Consequently, ecosystem processes must rely on energy gained from the oxidation of inorganic substrates or detrital organic matter. Subglacial Lake Whillans (SLW is one of more than 400 subglacial lakes known to exist under the Antarctic ice sheet; however, little is known about microbial physiology and energetics in these systems. When it was sampled through its 800 m thick ice cover in 2013, the SLW water column was shallow (~2 m deep, oxygenated, and possessed sufficient concentrations of C, N, and P substrates to support microbial growth. Here, we use a combination of physiological assays and models to assess the energetics of microbial life in SLW. In general, SLW microorganisms grew slowly in this energy-limited environment. Heterotrophic cellular carbon turnover times, calculated from 3H-thymidine and 3H-leucine incorporation rates, were long (60 to 500 days while cellular doubling times averaged 196 days. Inferred growth rates (average ~0.006 d-1 obtained from the same incubations were at least an order of magnitude lower than those measured in Antarctic surface lakes and oligotrophic areas of the ocean. Low growth efficiency (8% indicated that heterotrophic populations in SLW partition a majority of their carbon demand to cellular maintenance rather than growth. Chemoautotrophic CO2-fixation exceeded heterotrophic organic C-demand by a factor of ~1.5. Aerobic respiratory activity associated with heterotrophic and chemoautotrophic metabolism surpassed the estimated supply of oxygen to SLW, implying that microbial activity could deplete the oxygenated waters, resulting in anoxia. We used thermodynamic calculations to examine the biogeochemical and energetic consequences of environmentally imposed switching between aerobic and anaerobic metabolisms

  20. Nitrogen removal and electricity production at a double-chamber microbial fuel cell with cathode nitrite denitrification.

    Science.gov (United States)

    Yu, Yangyang; Zhao, Jianqiang; Wang, Sha; Zhao, Huimin; Ding, Xiaoqian; Gao, Kun

    2017-02-17

    Double-chamber microbial fuel cell was applied to investigate the performance of the electricity production and nitrite denitrification through feeding nitrite into the cathode. Factors influencing denitrification performance and power production, such as external resistance, influent nitrite concentration and Nitrite Oxygen Bacteria inhibitors, were studied. The results show that when the concentration of nitrite nitrogen and external resistance were 100 mg L(-1) and 10 Ω, respectively, the nitrite denitrification reached the best state. The NaN3 can inhibit nitrite oxidation effectively; meanwhile, the nitrite denitrification with N2O as the final products was largely improved. The [Formula: see text] was reduced to [Formula: see text], causing the cathode denitrification coulombic efficiency to exceed 100%. In chemoautotrophic bio-nitrification, microorganisms may utilize H2O to oxidize nitrite under anaerobic conditions. Proteobacteria might play a major role in the process of denitrification in MFC.

  1. The fas operon of Rhodococcus fascians encodes new genes required for efficient fasciation of host plants.

    Science.gov (United States)

    Crespi, M; Vereecke, D; Temmerman, W; Van Montagu, M; Desomer, J

    1994-01-01

    Three virulence loci (fas, att, and hyp) of Rhodococcus fascians D188 have been identified on a 200-kb conjugative linear plasmid (pFiD188). The fas locus was delimited to a 6.5-kb DNA fragment by insertion mutagenesis, single homologous disruptive recombination, and in trans complementation of different avirulent insertion mutants. The locus is arranged as a large operon containing six open reading frames whose expression is specifically induced during the interaction with host plants. One predicted protein is homologous to P-450 cytochromes from actinomycetes. The putative ferredoxin component is of a novel type containing additional domains homologous to transketolases from chemoautotrophic, photosynthetic, and methylotrophic microorganisms. Genetic analysis revealed that fas encodes, in addition to the previously identified ipt, at least two new genes that are involved in fasciation development, one of which is only required on older tobacco plants. PMID:8169198

  2. High-temperature water–rock interactions and hydrothermal environments in the chondrite-like core of Enceladus

    Science.gov (United States)

    Sekine, Yasuhito; Shibuya, Takazo; Postberg, Frank; Hsu, Hsiang-Wen; Suzuki, Katsuhiko; Masaki, Yuka; Kuwatani, Tatsu; Mori, Megumi; Hong, Peng K.; Yoshizaki, Motoko; Tachibana, Shogo; Sirono, Sin-iti

    2015-01-01

    It has been suggested that Saturn's moon Enceladus possesses a subsurface ocean. The recent discovery of silica nanoparticles derived from Enceladus shows the presence of ongoing hydrothermal reactions in the interior. Here, we report results from detailed laboratory experiments to constrain the reaction conditions. To sustain the formation of silica nanoparticles, the composition of Enceladus' core needs to be similar to that of carbonaceous chondrites. We show that the presence of hydrothermal reactions would be consistent with NH3- and CO2-rich plume compositions. We suggest that high reaction temperatures (>50 °C) are required to form silica nanoparticles whether Enceladus' ocean is chemically open or closed to the icy crust. Such high temperatures imply either that Enceladus formed shortly after the formation of the solar system or that the current activity was triggered by a recent heating event. Under the required conditions, hydrogen production would proceed efficiently, which could provide chemical energy for chemoautotrophic life. PMID:26506464

  3. High-temperature water-rock interactions and hydrothermal environments in the chondrite-like core of Enceladus.

    Science.gov (United States)

    Sekine, Yasuhito; Shibuya, Takazo; Postberg, Frank; Hsu, Hsiang-Wen; Suzuki, Katsuhiko; Masaki, Yuka; Kuwatani, Tatsu; Mori, Megumi; Hong, Peng K; Yoshizaki, Motoko; Tachibana, Shogo; Sirono, Sin-iti

    2015-10-27

    It has been suggested that Saturn's moon Enceladus possesses a subsurface ocean. The recent discovery of silica nanoparticles derived from Enceladus shows the presence of ongoing hydrothermal reactions in the interior. Here, we report results from detailed laboratory experiments to constrain the reaction conditions. To sustain the formation of silica nanoparticles, the composition of Enceladus' core needs to be similar to that of carbonaceous chondrites. We show that the presence of hydrothermal reactions would be consistent with NH3- and CO2-rich plume compositions. We suggest that high reaction temperatures (>50 °C) are required to form silica nanoparticles whether Enceladus' ocean is chemically open or closed to the icy crust. Such high temperatures imply either that Enceladus formed shortly after the formation of the solar system or that the current activity was triggered by a recent heating event. Under the required conditions, hydrogen production would proceed efficiently, which could provide chemical energy for chemoautotrophic life.

  4. The giant ciliate Zoothamnium niveum and its thiotrophic epibiont Candidatus Thiobios zoothamnicoli: a model system to study interspecies cooperation

    Directory of Open Access Journals (Sweden)

    Monika eBright

    2014-04-01

    Full Text Available Symbioses between chemoautotrophic sulfur-oxidizing (thiotrophic bacteria and protists or animals are among the most diverse and prevalent in the ocean. They are extremely difficult to maintain in aquaria and no thiotrophic symbiosis involving an animal host has ever been successfully cultivated. In contrast, we have cultivated the giant ciliate Zoothamnium niveum and its obligate ectosymbiont Cand. Thiobios zoothamnicoli in small flow-through aquaria. This review provides an overview of the host and the symbiont and their phylogenetic relationships. We summarize our knowledge on the ecology, geographic distribution and life cycle of the host, on the vertical transmission of the symbiont, and on the cultivation of this symbiosis. We then discuss the benefits and costs involved in this cooperation compared with other thiotrophic symbioses and outline our view on the evolution and persistence of this byproduct mutualism.

  5. Metabolic profiles of prokaryotic and eukaryotic communities in deep-sea sponge Neamphius huxleyi [corrected]. indicated by metagenomics.

    Science.gov (United States)

    Li, Zhi-Yong; Wang, Yue-Zhu; He, Li-Ming; Zheng, Hua-Jun

    2014-01-27

    The whole metabolism of a sponge holobiont and the respective contributions of prokaryotic and eukaryotic symbionts and their associations with the sponge host remain largely unclear. Meanwhile, compared with shallow water sponges, deep-sea sponges are rarely understood. Here we report the metagenomic exploration of deep-sea sponge Neamphius huxleyi [corrected] . at the whole community level. Metagenomic data showed phylogenetically diverse prokaryotes and eukaryotes in Neamphius huxleyi [corrected]. MEGAN and gene enrichment analyses indicated different metabolic potentials of prokaryotic symbionts from eukaryotic symbionts, especially in nitrogen and carbon metabolisms, and their molecular interactions with the sponge host. These results supported the hypothesis that prokaryotic and eukaryotic symbionts have different ecological roles and relationships with sponge host. Moreover, vigorous denitrification, and CO2 fixation by chemoautotrophic prokaryotes were suggested for this deep-sea sponge. The study provided novel insights into the respective potentials of prokaryotic and eukaryotic symbionts and their associations with deep-sea sponge Neamphius huxleyi [corrected].

  6. Evidence for microbial carbon and sulfur cycling in deeply buried ridge flank basalt.

    Science.gov (United States)

    Lever, Mark A; Rouxel, Olivier; Alt, Jeffrey C; Shimizu, Nobumichi; Ono, Shuhei; Coggon, Rosalind M; Shanks, Wayne C; Lapham, Laura; Elvert, Marcus; Prieto-Mollar, Xavier; Hinrichs, Kai-Uwe; Inagaki, Fumio; Teske, Andreas

    2013-03-15

    Sediment-covered basalt on the flanks of mid-ocean ridges constitutes most of Earth's oceanic crust, but the composition and metabolic function of its microbial ecosystem are largely unknown. By drilling into 3.5-million-year-old subseafloor basalt, we demonstrated the presence of methane- and sulfur-cycling microbes on the eastern flank of the Juan de Fuca Ridge. Depth horizons with functional genes indicative of methane-cycling and sulfate-reducing microorganisms are enriched in solid-phase sulfur and total organic carbon, host δ(13)C- and δ(34)S-isotopic values with a biological imprint, and show clear signs of microbial activity when incubated in the laboratory. Downcore changes in carbon and sulfur cycling show discrete geochemical intervals with chemoautotrophic δ(13)C signatures locally attenuated by heterotrophic metabolism.

  7. The role of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans in arsenic bioleaching from soil.

    Science.gov (United States)

    Ko, Myoung-Soo; Park, Hyun-Sung; Kim, Kyoung-Woong; Lee, Jong-Un

    2013-12-01

    Bioleaching of As from the soil in an abandoned Ag-Au mine was carried out using Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans. A. ferrooxidans is an iron oxidizer and A. thiooxidans is a sulfur oxidizer. These two microbes are acidophilic and chemoautotrophic microbes. Soil samples were collected from the Myoungbong and Songcheon mines. The main contaminant of the soil was As, with an average concentration of 4,624 mg/kg at Myoungbong and 5,590 mg/kg at Songcheon. A. ferrooxidans and A. thiooxidans generated lower pH conditions during their metabolism process. The bioleaching of As from soil has a higher removal efficiency than chemical leaching. A. ferrooxidans could remove 70 % of the As from the Myoungbong and Songcheon soils; however, A. thiooxidans extracted only 40 % of the As from the Myoungbong soil. This study shows that bioleaching is an effective process for As removal from soil.

  8. Environmental genomics reveals a single species ecosystem deep within the Earth

    Energy Technology Data Exchange (ETDEWEB)

    Chivian, Dylan; Brodie, Eoin L.; Alm, Eric J.; Culley, David E.; Dehal, Paramvir S.; DeSantis, Todd Z.; Gihring, Thomas M.; Lapidus, Alla; Lin, Li-Hung; Lowry, Stephen R.; Moser, Duane P.; Richardson, Paul; Southam, Gordon; Wanger, Greg; Pratt, Lisa M.; Andersen, Gary L.; Hazen, Terry C.; Brockman, Fred J.; Arkin, Adam P.; Onstott, Tullis C.

    2008-09-17

    DNA from low biodiversity fracture water collected at 2.8 km depth in a South African gold mine was sequenced and assembled into a single, complete genome. This bacterium, Candidatus Desulforudis audaxviator, comprises>99.9percent of the microorganisms inhabiting the fluid phase of this particular fracture. Its genome indicates a motile, sporulating, sulfate reducing, chemoautotrophic thermophile that can fix its own nitrogen and carbon using machinery shared with archaea. Candidatus Desulforudis audaxviator is capable of an independent lifestyle well suited to long-term isolation from the photosphere deep within Earth?s crust, and offers the first example of a natural ecosystem that appears to have its biological component entirely encoded within a single genome.

  9. The Role of Seep Ecosystems in Distribution Patterns of Deep-Sea Megafauna

    Science.gov (United States)

    Wagner, J.; McKelvey, Z.; Jacobson, A.; Hoerauf, E.; Van Dover, C. L.

    2015-12-01

    One of the key questions about methane seeps is the sphere of influence on the surrounding area they provide in terms of habitat structure, food sources, and geochemical environment. Understanding the distribution of megafauna relative to the seep environment is an initial step toward understanding these ecosystem properties. Systematic photo surveys using AUV Sentry were conducted at 4 methane seeps at the Blake Ridge Diapir and a seep at Cape Fear Diapir. Distributions of dominant seep features (bivalves, carbonates, bacterial mats) were used to define the active seep site. Geospatial mapping indicates that non-seep-endemic taxa (those not hosting chemoautotrophic endosymbionts) either avoid (e.g., sea urchins, certain sea cucumbers), are attracted to (e.g., squat lobsters, cake urchins) or show no distributional bias to (e.g., sea stars, certain fish) the presence of a seep. Further investigation into these faunal relationships may improve understanding of services that seeps provide to the larger ocean ecosystem.

  10. The Diversity of Sulfide Oxidation and Sulfate Reduction Genes Expressed by the Bacterial Communities of the Cariaco Basin, Venezuela.

    Science.gov (United States)

    Rodriguez-Mora, Maria J; Edgcomb, Virginia P; Taylor, Craig; Scranton, Mary I; Taylor, Gordon T; Chistoserdov, Andrei Y

    2016-01-01

    Qualitative expression of dissimilative sulfite reductase (dsrA), a key gene in sulfate reduction, and sulfide:quinone oxidoreductase (sqr), a key gene in sulfide oxidation was investigated. Neither of the two could be amplified from mRNA retrieved with Niskin bottles but were amplified from mRNA retrieved by the Deep SID. The sqr and sqr-like genes retrieved from the Cariaco Basin were related to the sqr genes from a Bradyrhizobium sp., Methylomicrobium alcaliphilum, Sulfurovum sp. NBC37-1, Sulfurimonas autotrophica, Thiorhodospira sibirica and Chlorobium tepidum. The dsrA gene sequences obtained from the redoxcline of the Cariaco Basin belonged to chemoorganotrophic and chemoautotrophic sulfate and sulfur reducers belonging to the class Deltaproteobacteria (phylum Proteobacteria) and the order Clostridiales (phylum Firmicutes).

  11. City sewer collectors biocorrosion

    Science.gov (United States)

    Ksiażek, Mariusz

    2014-12-01

    This paper presents the biocorrosion of city sewer collectors impregnated with special polymer sulphur binders, polymerized sulphur, which is applied as the industrial waste material. The city sewer collectors are settled with a colony of soil bacteria which have corrosive effects on its structure. Chemoautotrophic nitrifying bacteria utilize the residues of halites (carbamide) which migrate in the city sewer collectors, due to the damaged dampproofing of the roadway and produce nitrogen salts. Chemoorganotrophic bacteria utilize the traces of organic substrates and produce a number of organic acids (formic, acetic, propionic, citric, oxalic and other). The activity of microorganisms so enables the origination of primary and secondary salts which affect physical properties of concretes in city sewer collectors unfavourably.

  12. Metagenome of a Versatile Chemolithoautotroph from Expanding Oceanic Dead Zones

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, David A.; Zaikova, Elena; Howes, Charles L.; Song, Young; Wright, Jody; Tringe, Susannah G.; Tortell, Philippe D.; Hallam, Steven J.

    2009-07-15

    Oxygen minimum zones (OMZs), also known as oceanic"dead zones", are widespread oceanographic features currently expanding due to global warming and coastal eutrophication. Although inhospitable to metazoan life, OMZs support a thriving but cryptic microbiota whose combined metabolic activity is intimately connected to nutrient and trace gas cycling within the global ocean. Here we report time-resolved metagenomic analyses of a ubiquitous and abundant but uncultivated OMZ microbe (SUP05) closely related to chemoautotrophic gill symbionts of deep-sea clams and mussels. The SUP05 metagenome harbors a versatile repertoire of genes mediating autotrophic carbon assimilation, sulfur-oxidation and nitrate respiration responsive to a wide range of water column redox states. Thus, SUP05 plays integral roles in shaping nutrient and energy flow within oxygen-deficient oceanic waters via carbon sequestration, sulfide detoxification and biological nitrogen loss with important implications for marine productivity and atmospheric greenhouse control.

  13. Metabolic profiles of prokaryotic and eukaryotic communities in deep-sea sponge Lamellomorpha sp. indicated by metagenomics

    Science.gov (United States)

    Li, Zhi-Yong; Wang, Yue-Zhu; He, Li-Ming; Zheng, Hua-Jun

    2014-01-01

    The whole metabolism of a sponge holobiont and the respective contributions of prokaryotic and eukaryotic symbionts and their associations with the sponge host remain largely unclear. Meanwhile, compared with shallow water sponges, deep-sea sponges are rarely understood. Here we report the metagenomic exploration of deep-sea sponge Lamellomorpha sp. at the whole community level. Metagenomic data showed phylogenetically diverse prokaryotes and eukaryotes in Lamellomorpha sp.. MEGAN and gene enrichment analyses indicated different metabolic potentials of prokaryotic symbionts from eukaryotic symbionts, especially in nitrogen and carbon metabolisms, and their molecular interactions with the sponge host. These results supported the hypothesis that prokaryotic and eukaryotic symbionts have different ecological roles and relationships with sponge host. Moreover, vigorous denitrification, and CO2 fixation by chemoautotrophic prokaryotes were suggested for this deep-sea sponge. The study provided novel insights into the respective potentials of prokaryotic and eukaryotic symbionts and their associations with deep-sea sponge Lamellomorpha sp..

  14. Host-symbiont relationships in hydrothermal vent gastropods of the genus Alviniconcha from the Southwest Pacific.

    Science.gov (United States)

    Suzuki, Yohey; Kojima, Shigeaki; Sasaki, Takenori; Suzuki, Masae; Utsumi, Takashi; Watanabe, Hiromi; Urakawa, Hidetoshi; Tsuchida, Shinji; Nunoura, Takuro; Hirayama, Hisako; Takai, Ken; Nealson, Kenneth H; Horikoshi, Koki

    2006-02-01

    Hydrothermal vent gastropods of the genus Alviniconcha are unique among metazoans in their ability to derive their nutrition from chemoautotrophic gamma- and epsilon-proteobacterial endosymbionts. Although host-symbiont relationships in Alviniconcha gastropods from the Central Indian Ridge in the Indian Ocean and the Mariana Trough in the Western Pacific have been studied extensively, host-symbiont relationships in Alviniconcha gastropods from the Southwest Pacific remain largely unknown. Phylogenetic analysis using mitochondrial cytochrome c oxidase subunit I gene sequences of host gastropods from the Manus, North Fiji, and Lau Back-Arc Basins in the Southwest Pacific has revealed a new host lineage in a Alviniconcha gastropod from the Lau Basin and the occurrence of the host lineage Alviniconcha sp. type 2 in the Manus Basin. Based on 16S rRNA gene sequences of bacterial endosymbionts, two gamma-proteobacterial lineages and one epsilon-proteobacterial lineage were identified in the present study. The carbon isotopic compositions of the biomass and fatty acids of the gastropod tissues suggest that the gamma- and epsilon-proteobacterial endosymbionts mediate the Calvin-Benson cycle and the reductive tricarboxylic acid cycle, respectively, for their chemoautotrophic growth. Coupling of the host and symbiont lineages from the three Southwest Pacific basins revealed that each of the Alviniconcha lineages harbors different bacterial endosymbionts belonging to either the gamma- or epsilon-Proteobacteria. The host specificity exhibited in symbiont selection provides support for the recognition of each of the host lineages as a distinct species. The results from the present study also suggest the possibility that Alviniconcha sp. types 1 and 2 separately inhabit hydrothermal vent sites approximately 120 m apart in the North Fiji Basin and 500 m apart in the Manus Basin.

  15. Loss of genes related to Nucleotide Excision Repair (NER) and implications for reductive genome evolution in symbionts of deep-sea vesicomyid clams

    Science.gov (United States)

    Shimamura, Shigeru; Kaneko, Takashi; Ozawa, Genki; Matsumoto, Mamiko Nishino; Koshiishi, Takeru; Takaki, Yoshihiro; Kato, Chiaki; Takai, Ken; Yoshida, Takao; Fujikura, Katsunori; Barry, James P.

    2017-01-01

    Intracellular thioautotrophic symbionts of deep-sea vesicomyid clams lack some DNA repair genes and are thought to be undergoing reductive genome evolution (RGE). In this study, we addressed two questions, 1) how these symbionts lost their DNA repair genes and 2) how such losses affect RGE. For the first question, we examined genes associated with nucleotide excision repair (NER; uvrA, uvrB, uvrC, uvrD, uvrD paralog [uvrDp] and mfd) in 12 symbionts of vesicomyid clams belonging to two clades (5 clade I and 7 clade II symbionts). While uvrA, uvrDp and mfd were conserved in all symbionts, uvrB and uvrC were degraded in all clade I symbionts but were apparently intact in clade II symbionts. UvrD was disrupted in two clade II symbionts. Among the intact genes in Ca. Vesicomyosocius okutanii (clade I), expressions of uvrD and mfd were detected by reverse transcription-polymerase chain reaction (RT-PCR), but those of uvrA and uvrDp were not. In contrast, all intact genes were expressed in the symbiont of Calyptogena pacifica (clade II). To assess how gene losses affect RGE (question 2), genetic distances of the examined genes in symbionts from Bathymodiolus septemdierum were shown to be larger in clade I than clade II symbionts. In addition, these genes had lower guanine+cytosine (GC) content and higher repeat sequence densities in clade I than measured in clade II. Our results suggest that NER genes are currently being lost from the extant lineages of vesicomyid clam symbionts. The loss of NER genes and mutY in these symbionts is likely to promote increases in genetic distance and repeat sequence density as well as reduced GC content in genomic genes, and may have facilitated reductive evolution of the genome. PMID:28199404

  16. Expression of genes involved in the uptake of inorganic carbon in the gill of a deep-sea vesicomyid clam harboring intracellular thioautotrophic bacteria.

    Science.gov (United States)

    Hongo, Yuki; Ikuta, Tetsuro; Takaki, Yoshihiro; Shimamura, Shigeru; Shigenobu, Shuji; Maruyama, Tadashi; Yoshida, Takao

    2016-07-10

    Deep-sea vesicomyid clams, including the genus Phreagena (formerly Calyptogena), harbor thioautotrophic bacterial symbionts in the host symbiosome, which consists of cytoplasmic vacuoles in gill epithelial cells called bacteriocytes. The symbiont requires inorganic carbon (Ci), such as CO2, HCO3(-), and CO3(2-), to synthesize organic compounds, which are utilized by the host clam. The dominant Ci in seawater is HCO3(-), which is impermeable to cell membranes. Within the bacteriocyte, cytoplasmic carbonic anhydrase (CA) from the host, which catalyzes the inter-conversion between CO2 and HCO3(-), has been shown to be abundant and is thought to supply intracellular CO2 to symbionts in the symbiosome. However, the mechanism of Ci uptake by the host gill from seawater is poorly understood. To elucidate the influx pathway of Ci into the bacteriocyte, we isolated the genes related to Ci uptake via the pyrosequencing of cDNA from the gill of Phreagena okutanii, and investigated their expression patterns. Using phylogenetic and amino acid sequence analyses, three solute carrier family 4 (SLC4) bicarbonate transporters (slc4co1, slc4co2, and slc4co4) and two membrane-associated CAs (mcaco1 and mcaco2) were identified as candidate genes for Ci uptake. In an in situ hybridization analysis of gill sections, the expression of mcaco1 and mcaco2 was detected in the bacteriocytes and asymbiotic non-ciliated cells, respectively, and the expression of slc4co1 and slc4co2 was detected in the asymbiotic cells, including the intermediate cells of the inner area and the non-ciliated cells of the external area. Although subcellular localizations of the products of these genes have not been fully elucidated, they may play an important role in the uptake of Ci into the bacteriocytes. These findings will improve our understanding of the Ci transport system in the symbiotic relationships of chemosynthetic bivalves.

  17. Preservation and Observation of Amterior Ciliary Vessels in Rectus Muscles during Strabismus Surgery

    Institute of Scientific and Technical Information of China (English)

    GuanghuanMai; JianhuaYan

    1995-01-01

    Purpose:To observe the form and number of the anterior ciliary vessels(ACV)in rectus muscles.To train technician in preservation an d obsevation of ACV,so preservation can be done in caes with a rish of anterior segment ischemia(ASI).Methods:Curved foreign knife,iris hook,plastic rubber band and standard operat-ing loupes(3x)or microscope were used in the surgery on 34cases of comitant strabismus and 18cases of paralytic strabismus.Results:The ACVs per muscle in medial,lateral,superior,inferior rectus were3.08,3.26,3.50and3.50respectively in 89muscles of 52surgical strabismus cas-es.All ACVs in 16rectus muscles and 90out of 220ACVs in 73rectus muscles were too small ortoo short to be dissected.The sucess rate of ACV preservation was91.5%(119/130).105out of 130vessels were saved using loupe magnifica-tion and 14pit pf130vessels were saved under operating microscope.Conclusions:The number of ACVinrectus muscles are more than 2in our obser-vation cases.The ACVpreservation has the clinical value of allowing us toper-form muscle sugery on three or more rectus muscles simultaneously and get fonal surgical results more earlier after acv in each muscle are dissected and preserved otherwinse staged surgery are needed.The each strabismus surgeon must knov this technique.

  18. Nutrient distribution in flowering stems, nutrient removal and fertilization of three proteaceae cultivars

    Directory of Open Access Journals (Sweden)

    M.M. Hernández

    2014-06-01

    Full Text Available Several parameters of flowering stems of two cultivars of protea Leucospermum cordifolium (Knight Fourc (‘Succession II’ and ‘Tango’ and one of protea Protea L. (Protea susannae x magnifica ‘Susara’ were studied in different commercial plantations. These included length and weight measures, nutrient concentrations of detached parts (flower heads, leaves and stems, and removal of nutrients of harvested flowers. A base for fertilization was also calculated. Harvested flowers of ‘Susara’ removed more P, K and Cu than ‘Succession II’ and ‘Tango’, and more Ca and Fe than ‘Tango’. ‘Succession II’ showed the highest Zn removal. The P and Cu removal by the crop of ‘Susara’ were significantly higher than those of both Leucospermum cultivars, while K, Ca, and Fe outputs of ‘Susara’ exceeded only those of ‘Tango’. The nutrient top removals amounted to 4.55 g m-2 of N, 0.48 g m-2 of P, and 5.26 g m-2 of K. Data as a base to supply fertilizer to each cultivar are given, with N:P:K ratios of 1:0.08:0.87 for ‘Succession II’, 1:0.08:0.83 for ‘Tango’ and 1:0.10:1.27 for ‘Susara’.

  19. The Lepidoptera associated with forestry crop species in Brazil: a historical approach.

    Science.gov (United States)

    Kowalczuck, Manoela; Carneiro, E; Casagrande, M M; Mielke, O H H

    2012-10-01

    Despite the long history of forestry activity in Brazil and its importance to the national economy, there is still much disorder in the information regarding pests of forestry species. Considering the importance of the entomological knowledge for the viability of silvicultural management, this work aimed to gather information on the species of Lepidoptera associated with forestry crops within Brazil using a historical approach. Through a literature review, all registered species of Lepidoptera related to forestry crops in Brazil from 1896 to 2010 were identified. The historical evaluation was based on the comparison of the number of published articles, species richness, and community similarities of the Lepidoptera and their associated forest crops, grouped in 10-year samples. A total of 417 occurrences of Lepidoptera associated with forestry species were recorded, from which 84 species are related with 40 different forestry crops. The nocturnal Lepidoptera were dominant on the records, with Eacles imperialis magnifica Walker as the most frequent pest species cited. Myrtaceae was the most frequent plant family, with Cedrela fissilis as the most cited forestry crop species. A successional change in both Lepidoptera species and their host plants was observed over the decades. The richness of lepidopteran pest species increased over the years, unlike the richness of forestry crop species. This increase could be related to the inefficient enforcement of sanitary barriers, to the increase of monoculture areas, and to the adaptability of native pests to exotic forestry species used in monoculture stands.

  20. Hatchery production of the clownfish Amphiprion nigripes at Agatti Island, Lakshadweep, India.

    Science.gov (United States)

    Kumar, T T Ajith; Gopi, M; Dhaneesh, K V; Vinoth, R; Ghosh, S; Balasubramanian, T; Shunmugaraj, T

    2012-05-01

    Healthy individuals of matured clownfish, Amphiprion nigripes and sea anemone, Heteractis magnifica were collected from the Agatti island lagoon by snorkeling. During 'conditioning' for 3 months, pair formation occurred and the same were transferred to rectangular fiber glass spawning tanks of 10001 capacity. Suitable water quality parameters were maintained. The fishes were fed with tuna eggs, boiled clam meat, squid, octopus and trash fish thrice in a day. Reproductive behaviour and embryonic development were documented. Spawning took place in between 0900 - 1100 hr and hatched-out occurs, after sunset following an incubation period of 8-9 days. Size of the newly laid egg was 2.0-2.2 mm in length and 1.0-1.2 mm in width. The larval rearing tanks were maintained with UV-treated water and followed the optimal physico-chemical parameters as in the parent tanks. The different light regimes and diets were used for the successful larval rearing. The maximum larval survival (61%) was achieved at the photoperiod of 24 L/0D. Within 15-17 days, the larvae metamorphosed and took up parent colouration and comparatively high growth rate was observed when fed on algae enriched rotifer than those with poly unsaturated fatty acid (PUFA).

  1. 三角梅属四个品种花挥发性组分的GC-MS分析%Analysis of Volatile Components of Flowers from Four Bougainvilleas by GC-MS

    Institute of Scientific and Technical Information of China (English)

    徐夙侠; 黄青云; 刘鸿洲; 林春松

    2010-01-01

    三角梅不仅观赏性强,而且具有多方面的保健作用.为了揭示三角梅的次生代谢机制,本研究采用水蒸气蒸馏法提取三角梅属四个品种(Bougainvillea glabra 'Magnifica'、Bougainvillea glabra 'Pink Pixie'、Bougainvillea glabra 'Formosa' 和Bougainvillea×buttiana 'Mahara')花的挥发性成分;通过GC-MS法对所提取的成分进行定性和定量分析.共分离出85种成分,经NIST数据库检索,并与标准谱图比较共鉴定出72个化学组分,占总挥发性组分含量的90%以上.结果表明,4个三角梅品种的花中含有植醇、丁子香酚、亚油酸、亚麻酸以及维生素E等对人类有益的化合物.

  2. Efficacy of three conditions of radiographic interpretation for assessment root canal length Eficácia de três condições de interpretação radiográfica em odontometria

    Directory of Open Access Journals (Sweden)

    Mitsuru Ogata

    2005-03-01

    , de arquivos foram medidas, em mm, da extremidade da lima ao ápice radiográfico, com a utilização de um paquímetro digital. Foram feitas três medidas em cada radiografia e em seguida foi calculada a média. Após um período de 12 dias, as medidas foram repetidas. As três condições experimentais de interpretação radiográfica foram: negatoscópio sem máscara e sem magnificação (Visual; 2 negatoscópio com lente de aumento de 2,5 X e com máscara (Magnificação e 3 bloqueador de luz e lente de aumento de 1,75 X (Bloqueador. As médias e os desvios-padrão das medidas foram calculados e realizada uma análise descritiva. Foi utilizada a análise de variância a dois critérios (ANOVA para avaliar a concordância intra-observador e intramétodo. O erro das medidas foi calculado pela fórmula de Dalhberg. RESULTADOS: O teste ANOVA não mostrou diferenças significantes entre as duas sessões de observação, métodos de interpretação ou interação entre as sessões de interpretação e método (p>0,05. A medida intra-observador foi 0,02 mm para os métodos Visual e Magnificação e 0,01 mm para o Bloqueador. CONCLUSÃO: Parece não haver qualquer vantagem realizar medidas da distância entre o ápice radicular e o extremo da lima endodôntica em dentes incisivos superiores utilizando máscara ou magnificação da imagem.

  3. TWO FUNDAMENTAL ECOLOGICAL RELATIONSHIPS THAT DEEPEN THE SENSE OF SOCIAL, ECONOMICAL AND ETHICAL VALUES OF MENTAL REPRESENTATIONS

    Directory of Open Access Journals (Sweden)

    ALFREDO O. LÓPEZ ALONSO

    2010-01-01

    Full Text Available A partir de dos relaciones ecológicas básicas, ferocidad / depredación y angelicalidad / protección, se ensayan diferentes progresiones biológico- sociales y culturales. La primera relación está directamente referida a las figuras presa y depredador en cadenas tróficas y ecosistemas de competitividad y convivencia. La segunda magnifica el valor y significado del cuidado y supervivencia del recién nacido. Se revisa el origen evolutivo, ecológico y etológico de ambas relaciones como balance conductual entre situaciones extremas de cada individuo y especie, abrien do un nuevo insight sobre viejos problemas de la Biología, la Sociología, la Etica y la Economía. La clave es lo que relaciona a estas dos relaciones con valores materiales-tangibles y valores in materialesintangibles, respectivamente. Resulta directo asociar la primera relación con la satisfacción inmediata de necesidades básicas, juzgadas como materiales y tan gibles. En contraste, la segunda relación viene como un complemento que genera nuevos significados y riqueza de sentidos ecológico- etológicos de toda forma de vida. Los valores se estiman como un sistema abierto y creciente. A más valores intangibles, mayor es el avance en representaciones significantes.

  4. Diversity of mycorrhizal fungi of terrestrial orchids: compatibility webs, brief encounters, lasting relationships and alien invasions.

    Science.gov (United States)

    Bonnardeaux, Yumiko; Brundrett, Mark; Batty, Andrew; Dixon, Kingsley; Koch, John; Sivasithamparam, K

    2007-01-01

    The diversity of mycorrhizal fungi associated with an introduced weed-like South African orchid (Disa bracteata) and a disturbance-intolerant, widespread, native West Australian orchid (Pyrorchis nigricans) were compared by molecular identification of the fungi isolated from single pelotons. Molecular identification revealed both orchids were associated with fungi from diverse groups in the Rhizoctonia complex with worldwide distribution. Symbiotic germination assays confirmed the majority of fungi isolated from pelotons were mycorrhizal and a factorial experiment uncovered complex webs of compatibility between six terrestrial orchids and 12 fungi from Australia and South Africa. Two weed-like (disturbance-tolerant rapidly spreading) orchids - D. bracteata and the indigenous Australian Microtis media, had the broadest webs of mycorrhizal fungi. In contrast, other native orchids had relatively small webs of fungi (Diuris magnifica and Thelymitra crinita), or germinated exclusively with their own fungus (Caladenia falcata and Pterostylis sanguinea). Orchids, such as D. bracteata and M. media, which form relationships with diverse webs of fungi, had apparent specificity that decreased with time, as some fungi had brief encounters with orchids that supported protocorm formation but not subsequent seedling growth. The interactions between orchid mycorrhizal fungi and their hosts are discussed.

  5. Nectar Meals of a Mosquito-Specialist Spider

    Directory of Open Access Journals (Sweden)

    Josiah O. Kuja

    2012-01-01

    Full Text Available Evarcha culicivora, an East African jumping spider, is known for feeding indirectly on vertebrate blood by actively choosing blood-carrying mosquitoes as prey. Using cold-anthrone tests to detect fructose, we demonstrate that E. culicivora also feeds on nectar. Field-collected individuals, found on the plant Lantana camara, tested positive for plant sugar (fructose. In the laboratory, E. culicivora tested positive for fructose after being kept with L. camara or one of another ten plant species (Aloe vera, Clerodendron magnifica, Hamelia patens, Lantana montevideo, Leonotis nepetaefolia, Parthenium hysterophorus, Ricinus communis, Senna didymobotrya, Striga asiatica, and Verbena trivernia. Our findings demonstrate that E. culicivora acquires fructose from its natural diet and can ingest fructose directly from plant nectaries. However, experiments in the laboratory also show that E. culicivora can obtain fructose indirectly by feeding on prey that have fed on fructose, implying a need to consider this possibility when field-collected spiders test positive for fructose. In laboratory tests, 53.5% of 1,215 small juveniles, but only 3.4% of 622 adult E. culicivora, left with plants for 24 hours, were positive for fructose. These findings, along with the field data, suggest that fructose is especially important for early-instar juveniles of E. culicivora.

  6. Generalized magnification in visual optics. Part 2: Magnification as affine transformation

    Directory of Open Access Journals (Sweden)

    W. F. Harris

    2010-12-01

    Full Text Available In astigmatic systems magnification may be different in different directions.  It may also be accompanied by rotation or reflection.  These changes from object to image are examples of generalized magnification.  They are represented by  2 2×  matrices.  Because they are linear transformations they can be called linear magnifications.  Linear magnifications account for a change in appearance without regard to position.  Mathematical structure suggests a natural further generalization to a magnification that is complete in the sense that it accountsfor change in appearance and position.  It is represented by a  3 3×  matrix with a dummy third row. The transformation is called affine in linear algebra which suggests that these generalized magnifica-tions be called affine magnifications.  The purpose of the paper is to define affine magnification in the context of astigmatic optics.  Several examples are presented and illustrated graphically. (S Afr Optom 2010 69(4 166-172

  7. Plastid ultrastructure and photosynthesis in greening petaloid hypsophylls.

    Science.gov (United States)

    Weidner, M; Franz, A; Napp-Zinn, K

    1985-02-01

    The ultrastructural and biochemicalphysiological aspects of postfloral greening have been studied in hypsophylls of Heliconia aurantiaca Ghiesbr., Guzmania cf. x magnifica Richter and Spathiphyllum wallisii Regel. In all three species the greening of the hypsophylls is due to plastid transformation, chloroplast formation proceeding from the initially different types of plastids. The degradation process of the original plastid structures and the mode of thylakoid formation are distinct in each case. In none of the species do the transformed plastids look identical to the chloroplasts of the corresponding foliage leaves. On a chlorophyll basis, the rate of photosynthesis of the greened hypsophylls surpasses the rate of the leaves considerably in Spathiphyllum, but is much lower in Heliconia (no data for Guzmania). In all species, anatomy, plastid structure, pigments, 77° K-fluorescence emission, ribulose-1,5-bis-phosphate carboxylase activities and short-term photosynthesis (14)CO2-assimilation patterns prove the greened hypsophylls to be capable of providing additional carbon to the developing fruits, thus supplementing the import of organic matter from the foliage leaves.

  8. Seven new species of Cerambycidae (Coleoptera from South America with the proposal of three new genera

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    Ubirajara R. Martins

    2012-12-01

    Full Text Available The following new species are described - Cerambycinae, Sydacini: Sydax flechtmanni sp. nov. from Brazil (São Paulo; Eburiini: Ebrodacrys biffipradorum sp. nov. from Brazil (Roraima; - Lamiinae, Pteropliini: Ataxia piauiensis sp. nov. from Brazil (Piuaí; Calliini: Amucallia carbonaria sp. nov. from French Guiana; A. citrina sp. nov. from Guiana. Also in Lamiinae, two new genera of Onciderini are proposed. Ubytyra gen. nov., type species U. tuberosa sp. nov. from Peru (Junin e Japi gen. nov., type species J. duartei sp. nov., from Brazil (São Paulo; Ubytyra gen. nov. can be distinguished by the sides of prothorax with long central spine rounded at apex, and this new feature among Onciderini is discussed. Japi gen. nov., is characterized by a fringe of long hairs on the inner side of antennomere III, present only in species from North and Central America, and gender comparison of these species is done and discussed. In Hemilophini, Pseudotacocha gen. nov., type species P. magnifica sp. nov. from Peru (Cuzco, are described. The new genera can be distinguished by eyes well developed, elytra with two carinae and the apices outer with short spine; a comparison with related genera is done.

  9. Microbial community structure and productivity in the oxygen minimum zone of the eastern tropical North Pacific

    Science.gov (United States)

    Podlaska, Agnieszka; Wakeham, Stuart G.; Fanning, Kent A.; Taylor, Gordon T.

    2012-08-01

    Microbial abundances and activities (heterotrophic and chemoautotrophic) were profiled in the fall of 2007 along a transect of four stations in the upwelling region between the Tehuantepec Bowl, off the coast of southern Mexico, and the Costa Rica Dome. Heterotrophic potential varied with depth exhibiting relatively low maximum values of 4-8 nM leucine d-1, but varied among stations by a factor of 2. Generally, heterotrophic potential varied inversely with nitrate implying NO3- draw down by nitrate-reducing chemoorganotrophs. Dark dissolved inorganic carbon assimilation (≈chemoautotrophy) was also highly variable with depth and reached a maximum value of 6.4 μM C d-1 at one station, but only attained maxima of 0.02 and 0.2 μM C d-1 at other stations. Elevated values of chemoautotrophy corresponded with enrichments in nitrite concentrations suggesting nitrification as well as with depletions in nitrite and ammonium concentrations suggesting anammox processes. Additions of 30 μM NH4+ at selected depths stimulated chemoautotrophic activity up to 33-fold. Fluorescence in situ hybridization (FISH) analyses revealed elevated abundances of Crenarchaeota and β-proteobacteria (up to 1.0×107 and 10.0×107 cells L-1, respectively) associated with NH4+ minima and NO3- maxima. Nitrifying β-proteobacteria were most abundant in the upper oxycline (1.1-1.8×107 cells L-1) at three stations and exhibited a secondary peak of 0.3×107 cells L-1 in the lower oxycline at one station. Anammox bacterial (Planctomycetes) abundances were as high as 2.1×106 cells L-1, but accounted for less than 1% of total DAPI counts. The concentration of diploptene (a hopanoid biomarker found in bacteria) varied from 2 to 15 pg L-1 in the upper oxycline and from 51 to 160 pg L-1 in the lower oxycline. Delta 13C values of particulate organic carbon (POC) varied from -30 to -21‰ in the water column (avg. -25‰). Distributions of isotopically light POC coincided with enrichments in diploptene

  10. Origin of sedimentary organic matter at the Northern Cascadia Margin

    Science.gov (United States)

    Kaneko, M.; Naraoka, H.

    2007-12-01

    Gas hydrate in marine sediments may have important roles on global carbon cycle and climatic change. We examined origins of sedimentary organic matter and bacterial activity in deep and hydrate-bearing sediment cored in Site U1327 and U1328 at northern Cascadia Margin by IODP Exp311, using σ13C of total organic carbon (TOC), σ15N of total nitrogen (TN), σ34S of total sulfur (TS), and σ13C of biomarkers in hydrocarbon fraction. In both sites, TOC/TN ratios and σ13C of TOC values ranged from 5.5 to 18.0 and -25.7 to -21.5 ‰, respectively, suggesting that sedimentary organic matter is a mixture of terrestrial and marine sources. Long chain (n)-alkanes (C27, C29, and C30), known as biomarkers of terrestrial higher plant were most abundant components (up to ~50 μg/gCorg) through down to 300 mbsf, and their σ13C values (-34.3 to -28.7 ‰) reveal their C3 plant origin. In addition, very long-chain alkene (C37) occurred in some sediments, which suggests the blooming by coccolithophore in the past. σ34S of TS values at both sites show large variation between -30 to +20 ‰. Most of σ34S of TS values were less than present σ34S value of seawater sulfate (+20.3 ‰). This is attributable to isotope fractionation during microbial sulfate reduction. Crocetenes including one double bond occurred in deep sediments with higher σ13C values (-23 ‰) than the reported σ13C values (< ~ -100 ‰, Elvert et al, 2000), providing possibility of heterotrophic archaea using marine organic matter as a carbon source. Pentamethylicosane (PMI) was detected in relatively high concentrations at 249 mbsf at Site U1328 and its σ13C value was -46.4 ‰. This PMI could be chemoautotrophic archaea in origin such as methanogen. Diploptene was also detected in most sediments with the σ13C value of -37 to -35 ‰, probably being characteristic of chemoautotrophic bacteria.

  11. Dynamic drivers of a shallow-water hydrothermal vent ecogeochemical system (Milos, Eastern Mediterranean)

    Science.gov (United States)

    Yücel, Mustafa; Sievert, Stefan; Giovanelli, Donato; Foustoukos, Dionysis; DeForce, Emelia; Thomas, François; Vetriani, Constantino; Le Bris, Nadine

    2014-05-01

    Shallow-water hydrothermal vents share many characteristics with their deep-sea analogs. However, despite ease of access, much less is known about the dynamics of these systems. Here, we report on the spatial and temporal chemical variability of a shallow-water vent system at Paleochori Bay, Milos Island, Greece, and on the bacterial and archaeal diversity of associated sandy sediments. Our multi-analyte voltammetric profiles of dissolved O2 and hydrothermal tracers (e.g. Fe2+, FeSaq, Mn2+) on sediment cores taken along a transect in hydrothermally affected sediments indicate three different areas: the central vent area (highest temperature) with a deeper penetration of oxygen into the sediment, and a lack of dissolved Fe2+ and Mn2+; a middle area (0.5 m away) rich in dissolved Fe2+ and Mn2+ (exceeding 2 mM) and high free sulfide with potential for microbial sulfide oxidation as suggested by the presence of white mats at the sediment surface; and, finally, an outer rim area (1-1.5 m away) with lower concentrations of Fe2+ and Mn2+ and higher signals of FeSaq, indicating an aged hydrothermal fluid contribution. In addition, high-frequency temperature series and continuous in situ H2S measurements with voltammetric sensors over a 6-day time period at a distance 0.5 m away from the vent center showed substantial temporal variability in temperature (32 to 46 ºC ) and total sulfide (488 to 1329 µM) in the upper sediment layer. Analysis of these data suggests that tides, winds, and abrupt geodynamic events generate intermittent mixing conditions lasting for several hours to days. Despite substantial variability, the concentration of sulfide available for chemoautotrophic microbes remained high. These findings are consistent with the predominance of Epsilonproteobacteria in the hydrothermally influenced sediments Diversity and metagenomic analyses on sediments and biofilm collected along a transect from the center to the outer rim of the vent provide further insights on

  12. Molecular characterization and endosymbiotic localization of the gene encoding D-ribulose 1,5-bisphosphate carboxylase-oxygenase (RuBisCO) form II in the deep-sea vestimentiferan trophosome.

    Science.gov (United States)

    Elsaied, Hosam; Kimura, Hiroyuki; Naganuma, Takeshi

    2002-06-01

    To better understand the contribution of micro-organisms to the primary production in the deep-sea gutless tubeworm Lamellibrachia sp., the 16S-rDNA-based phylogenetic data would be complemented by knowledge of the genes that encode the enzymes relevant to chemoautotrophic carbon fixation, such as D-ribulose 1,5-bisphosphate carboxylase-oxygenase (RuBisCO; EC 4.1.1.39). To phylogenetically characterize the autotrophic endosymbiosis within the trophosome of the tubeworm Lamellibrachia sp., bulk trophosomal DNA was extracted and analysed based on the 16S-rRNA- and RuBisCO-encoding genes. The 16S-rRNA- and RuBisCO-encoding genes were amplified by PCR, cloned and sequenced. For the 16S rDNA, a total of 50 clones were randomly selected and analysed directly by sequencing. Only one operational taxonomic unit resulted from the 16S rDNA sequence analysis. This may indicate the occurrence of one endosymbiotic bacterial species within the trophosome of the Lamellibrachia sp. used in this study. Phylogenetic analysis of the 16S rDNA showed that the Lamellibrachia sp. endosymbiont was closely related to the genus Rhodobacter, a member of the alpha-Protebacteria. For the RuBisCO genes, only the form II gene (cbbM) was amplified by PCR. A total of 50 cbbM clones were sequenced, and these were grouped into two operational RuBisCO units (ORUs) based on their deduced amino acid sequences. The cbbM ORUs showed high amino acid identities with those recorded from the ambient sediment bacteria. To confirm the results of sequence analysis, the localization of the symbiont-specific 16S rRNA and cbbM sequences in the Lamellibrachia sp. trophosome was visualized by in situ hybridization (ISH), using specific probes. Two types of cells, coccoid and filamentous, were observed at the peripheries of the trophosome lobules. Both the symbiont-specific 16S rDNA and cbbM probes hybridized at the same sites coincident with the location of the coccoid cells, whereas the filamentous cells showed no

  13. Yeast identification in floral nectar of Mimulus aurantiacus (Invited)

    Science.gov (United States)

    Kyauk, C.; Belisle, M.; Fukami, T.

    2009-12-01

    Nectar is such a sugar-rich resource that serves as a natural habitat in which microbes thrive. As a result, yeasts arrive to nectar on the bodies of pollinators such as hummingbirds and bees. Yeasts use the sugar in nectar for their own needs when introduced. This research focuses on the identification of different types of yeast that are found in the nectar of Mimulus aurantiacus (commonly known as sticky monkey-flower). Unopened Mimulus aurantiacus flower buds were tagged at Jasper Ridge and bagged three days later. Floral nectar was then extracted and plated on potato dextrose agar. Colonies on the plates were isolated and DNA was extracted from each sample using QIAGEN DNeasy Plant Mini Kit. The DNA was amplified through PCR and ran through gel electrophoresis. The PCR product was used to clone the nectar samples into an E.coli vector. Finally, a phylogenetic tree was created by BLAST searching sequences in GenBank using the Internal Transcribed Space (ITS) locus. It was found that 18 of the 50 identified species were Candida magnifica, 14 was Candida rancensis, 6 were Crytococcus albidus and there were 3 or less of the following: Starmella bombicola, Candida floricola, Aureobasidium pullulans, Pichia kluyvera, Metschnikowa cibodaserisis, Rhodotorua colostri, and Malassezia globosa. The low diversity of the yeast could have been due to several factors: time of collection, demographics of Jasper Ridge, low variety of pollinators, and sugar concentration of the nectar. The results of this study serve as a necessary first step for a recently started research project on ecological interactions between plants, pollinators, and nectar-living yeast. More generally, this research studies the use of the nectar-living yeast community as a natural microcosm for addressing basic questions about the role of dispersal and competitive and facilitative interactions in ecological succession.

  14. Sede de organizaciones internacionales y centro de conferencias, Viena - Austria

    Directory of Open Access Journals (Sweden)

    Staber, Johann

    1979-11-01

    Full Text Available This complex on one bank of the Danube, is located between Wagramer Street and the Danube Park, a beautiful area overlooking the City and surrounded by greenery. It includes: — Six Y-shaped buildings, four of them housing the administrative centers of two international organizations AIEA and UNODI and the other two used for common services. — One circular building used for international congresses. — One hexagon congress hall attached to a circular hotel building. In addition, the complex includes a multilevel car park, elevated pedestrian walks, two access plazas and full network of roads at different levels. The congress centre is the most essential element of the complex and, similarly as the circular international congress hall was designed with flexibility in mind, permitting a number of different floor arrangements using movable partitions.

    Este complejo, construido a orillas del Danubio, está situado entre la calle Wagramer y el parque del Danubio, en una zona de gran belleza, con magnificas vistas de la ciudad y con amplias zonas verdes. Consta de: —Seis edificios con plantas en forma de Y, cuatro de ellos utilizados para sedes administrativas de las Organizaciones Internacionales AIEA y UNODI, y los otros dos para servicios comunes. —Un edificio de planta circular destinado a Conferencias Internacionales. —Un Centro de Conferencias de planta hexagonal, adosado a un hotel de planta circular. El conjunto se completa con estacionamientos de varias plantas, pasarelas para peatones, dos plazas de acceso y un completo trazado viario con calles a distintos niveles. El Centro de Conferencias es la parte esencial del complejo y, al igual que el edificio circular para Conferencias Internacionales, admite distintas variantes en la distribución del espacio para salas mediante la utilización de tabiques móviles de separación.

  15. Phylogenetic inference of calyptrates, with the first mitogenomes for Gasterophilinae (Diptera: Oestridae) and Paramacronychiinae (Diptera: Sarcophagidae)

    Science.gov (United States)

    Zhang, Dong; Yan, Liping; Zhang, Ming; Chu, Hongjun; Cao, Jie; Li, Kai; Hu, Defu; Pape, Thomas

    2016-01-01

    The complete mitogenome of the horse stomach bot fly Gasterophilus pecorum (Fabricius) and a near-complete mitogenome of Wohlfahrt's wound myiasis fly Wohlfahrtia magnifica (Schiner) were sequenced. The mitogenomes contain the typical 37 mitogenes found in metazoans, organized in the same order and orientation as in other cyclorrhaphan Diptera. Phylogenetic analyses of mitogenomes from 38 calyptrate taxa with and without two non-calyptrate outgroups were performed using Bayesian Inference and Maximum Likelihood. Three sub-analyses were performed on the concatenated data: (1) not partitioned; (2) partitioned by gene; (3) 3rd codon positions of protein-coding genes omitted. We estimated the contribution of each of the mitochondrial genes for phylogenetic analysis, as well as the effect of some popular methodologies on calyptrate phylogeny reconstruction. In the favoured trees, the Oestroidea are nested within the muscoid grade. Relationships at the family level within Oestroidea are (remaining Calliphoridae (Sarcophagidae (Oestridae, Pollenia + Tachinidae))). Our mito-phylogenetic reconstruction of the Calyptratae presents the most extensive taxon coverage so far, and the risk of long-branch attraction is reduced by an appropriate selection of outgroups. We find that in the Calyptratae the ND2, ND5, ND1, COIII, and COI genes are more phylogenetically informative compared with other mitochondrial protein-coding genes. Our study provides evidence that data partitioning and the inclusion of conserved tRNA genes have little influence on calyptrate phylogeny reconstruction, and that the 3rd codon positions of protein-coding genes are not saturated and therefore should be included. PMID:27019632

  16. La Gazeta de Madrid y la Guerra de Sucesión

    Directory of Open Access Journals (Sweden)

    María Rosa CAL MARTÍNEZ

    2009-11-01

    Full Text Available RESUMEN: El artículo estudia el papel que desempeñó la Gazeta de Madrid durante la Guerra de Sucesión en España, tema inédito. Desde el siglo XVII las Cortes europeas disponían de publicaciones periódicas que amparaban o subvencionaban a cambio de controlar los contenidos y de que en ellas apareciesen todas las noticias que favoreciesen a las diversas Coronas. En España la primera Gazeta a favor de la monarquía surgió también en el siglo XVII fue una concesión del rey Felipe IV a su hijo bastardo Juan José de Austria. Es esta misma Gazeta (tras pasar por diferentes vicisitudes, la que recoge los acontecimientos de 1701 a 1714. Como vamos a comprobar, la publicación silencia las derrotas y los desastres, y magnifica las victorias y los éxitos de las tropas reales; y deja muy claro quiénes eran los amigos del monarca.ABSTRACT: This article studies the role that la Gazeta de Madrid had during the Spanish Succession War, a subject that has not been investigated before. Since the XVII century, European Courts had periodical publications that were supported or funded to control the information. Therefore, these publications only printed news approved by the Spanish Royalty and that favoured the different Crowns. In Spain, this first royalist Gazette in favour of monarchy also began in the XVII century and was a concession of Felipe IV to his bastard son, Juan José de Austria. This is also the Gazette, after different problems were overcome, that published information about the 1701-14 events. As we can see, the gazette remains silent about the defeats and magnifies the triumphs and successes of the royal troops, and gives a clear idea of who were the monarch’s friends.

  17. Phylogenetic inference of calyptrates, with the first mitogenomes for Gasterophilinae (Diptera: Oestridae) and Paramacronychiinae (Diptera: Sarcophagidae).

    Science.gov (United States)

    Zhang, Dong; Yan, Liping; Zhang, Ming; Chu, Hongjun; Cao, Jie; Li, Kai; Hu, Defu; Pape, Thomas

    2016-01-01

    The complete mitogenome of the horse stomach bot fly Gasterophilus pecorum (Fabricius) and a near-complete mitogenome of Wohlfahrt's wound myiasis fly Wohlfahrtia magnifica (Schiner) were sequenced. The mitogenomes contain the typical 37 mitogenes found in metazoans, organized in the same order and orientation as in other cyclorrhaphan Diptera. Phylogenetic analyses of mitogenomes from 38 calyptrate taxa with and without two non-calyptrate outgroups were performed using Bayesian Inference and Maximum Likelihood. Three sub-analyses were performed on the concatenated data: (1) not partitioned; (2) partitioned by gene; (3) 3rd codon positions of protein-coding genes omitted. We estimated the contribution of each of the mitochondrial genes for phylogenetic analysis, as well as the effect of some popular methodologies on calyptrate phylogeny reconstruction. In the favoured trees, the Oestroidea are nested within the muscoid grade. Relationships at the family level within Oestroidea are (remaining Calliphoridae (Sarcophagidae (Oestridae, Pollenia + Tachinidae))). Our mito-phylogenetic reconstruction of the Calyptratae presents the most extensive taxon coverage so far, and the risk of long-branch attraction is reduced by an appropriate selection of outgroups. We find that in the Calyptratae the ND2, ND5, ND1, COIII, and COI genes are more phylogenetically informative compared with other mitochondrial protein-coding genes. Our study provides evidence that data partitioning and the inclusion of conserved tRNA genes have little influence on calyptrate phylogeny reconstruction, and that the 3rd codon positions of protein-coding genes are not saturated and therefore should be included.

  18. Brazilian Atlantic Forest lato sensu: the most ancient Brazilian forest, and a biodiversity hotspot, is highly threatened by climate change

    Directory of Open Access Journals (Sweden)

    AF. Colombo

    Full Text Available After 500 years of exploitation and destruction, the Brazilian Atlantic Forest has been reduced to less the 8% of its original cover, and climate change may pose a new threat to the remnants of this biodiversity hotspot. In this study we used modelling techniques to determine present and future geographical distribution of 38 species of trees that are typical of the Brazilian Atlantic Forest (Mata Atlântica, considering two global warming scenarios. The optimistic scenario, based in a 0.5% increase in the concentration of CO2 in the atmosphere, predicts an increase of up to 2 °C in the Earth's average temperature; in the pessimistic scenario, based on a 1% increase in the concentration of CO2 in the atmosphere, temperature increase may reach 4 °C. Using these parameters, the occurrence points of the studied species registered in literature, the Genetic Algorithm for Rule-set Predictions/GARP and Maximum entropy modeling of species geographic distributions/MaxEnt we developed models of present and future possible occurrence of each species, considering Earth's mean temperature by 2050 with the optimistic and the pessimistic scenarios of CO2 emission. The results obtained show an alarming reduction in the area of possible occurrence of the species studied, as well as a shift towards southern areas of Brazil. Using GARP, on average, in the optimistic scenario this reduction is of 25% while in the pessimistic scenario it reaches 50%, and the species that will suffer the worst reduction in their possible area of occurrence are: Euterpe edulis, Mollinedia schottiana, Virola bicuhyba, Inga sessilis and Vochysia magnifica. Using MaxEnt, on average, in the optimistic scenario the reduction will be of 20% while in the pessimistic scenario it reaches 30%, and the species that will suffer the worst reduction are: Hyeronima alchorneoides, Schefflera angustissima, Andira fraxinifolia and the species of Myrtaceae studied.

  19. Spatial patterns of large natural fires in Sierra Nevada wilderness areas

    Science.gov (United States)

    Collins, B.M.; Kelly, M.; van Wagtendonk, J.W.; Stephens, S.L.

    2007-01-01

    The effects of fire on vegetation vary based on the properties and amount of existing biomass (or fuel) in a forest stand, weather conditions, and topography. Identifying controls over the spatial patterning of fire-induced vegetation change, or fire severity, is critical in understanding fire as a landscape scale process. We use gridded estimates of fire severity, derived from Landsat ETM+ imagery, to identify the biotic and abiotic factors contributing to the observed spatial patterns of fire severity in two large natural fires. Regression tree analysis indicates the importance of weather, topography, and vegetation variables in explaining fire severity patterns between the two fires. Relative humidity explained the highest proportion of total sum of squares throughout the Hoover fire (Yosemite National Park, 2001). The lowest fire severity corresponded with increased relative humidity. For the Williams fire (Sequoia/Kings Canyon National Parks, 2003) dominant vegetation type explains the highest proportion of sum of squares. Dominant vegetation was also important in determining fire severity throughout the Hoover fire. In both fires, forest stands that were dominated by lodgepole pine (Pinus contorta) burned at highest severity, while red fir (Abies magnifica) stands corresponded with the lowest fire severities. There was evidence in both fires that lower wind speed corresponded with higher fire severity, although the highest fire severity in the Williams fire occurred during increased wind speed. Additionally, in the vegetation types that were associated with lower severity, burn severity was lowest when the time since last fire was fewer than 11 and 17 years for the Williams and Hoover fires, respectively. Based on the factors and patterns identified, managers can anticipate the effects of management ignited and naturally ignited fires at the forest stand and the landscape levels. ?? 2007 Springer Science+Business Media, Inc.

  20. The Prevalence of Sheep Traumatic Myiasis in Three Counties from the West Side of Romania and Bacteria Isolated from the Insects Maggots

    Directory of Open Access Journals (Sweden)

    Daniela Marina Mot

    2013-10-01

    Full Text Available Myiasis represents an infestation of animals and humans caused by the maggots of certain fly species of Diptera order, Insecta class, which feed on the hosts' living or dead tissues or body fluids. In sheep, myiasis is a major animal welfare issue developing serious pain, suffering and in untreated cases may result in tissue injuries, reproduction and productivity losses and even death. There are two most important fly species which cause traumatic cutaneous myiasis of sheep in Europe: Wohlfahrtia magnifica (Sarcophagidae implicated in etiology of wound myiasis in southern and eastern Europe and Lucilia sericata (Calliphoridae, implicated in etiology of sheep strike, mainly in the middle latitudes of Europe continent. A few farmers from Timiş, Arad and Caraş-Severin counties were been asked to response to a questionnaire on the prevalence of traumatic myiasis which evolved in their sheep flock in April-September period of year 2012. From a total number of 2206 sheep taken into study were been discovered 1658 healthy sheep (75.16% and 548 sheep with myiasis (24.84%. From identified lesions with myiasis were been collected insects maggots from all three stages of development and were been prepared in Microbiology laboratory in the view to obtain data on the culturable bacteria isolated under aerobic conditions. Bacteria detected from maggots samples were: Staphylococcus aureus, Bacillus subtilis, Proteus vulgaris, Micrococcus luteus and Escherichia coli. The myasis insects maggots in sheep infestation can acquire many bacteria from their host or from their surroundings, all these can, together another bacteria, complicate the lesions and without treatment may lead to animals death.

  1. Restauración del Teatro Español Madrid-España

    Directory of Open Access Journals (Sweden)

    Editorial, Equipo

    1980-04-01

    Full Text Available In October 1975 the Spanish National Theatre was destroyed by a fire which started on stage and reached a large part of the theatre and the ceiling which, with its great candelabra, collapsed onto the parterre. The Madrid Town Hall, with the cooperation of the Ministry of Culture, performed magnificent restoration work and converted this theatre in one of the most advances in our country, not only regarding its scenery technique — taking maximum advantage of the stage, deepening the pits, establishing new borders and stage machinery, etc. — but also adding some magnificent installations, such as the air conditioning and the sophisticated electronic heat and smoke detector system.

    El Teatro Español, en octubre de 1975, se destruyó por un incendio iniciado en el escenario y que alcanzó una gran parte de la sala y del techo, el cual, con su gran lámpara, se derrumbo sobre el patio de butacas. El Ayuntamiento de Madrid, con la colaboración del Ministerio de Cultura, realizó una magnífica labor de restauración y convirtió este teatro en uno de los más avanzados de nuestro país, no sólo en cuanto a su técnica escénica —aprovechando al máximo el escenario, profundizando los fosos, estableciendo nuevas bambalinas y tramoyas, etc.— sino además añadiéndole unas magnificas instalaciones, tales como la de aire acondicionado y el sofisticado sistema de detectores electrónicos de calor y humo.

  2. From Black Hole to Hydrate Hole: Gas hydrates, authigenic carbonates and vent biota as indicators of fluid migration at pockmark sites of the Northern Congo Fan

    Science.gov (United States)

    Kasten, S.; Schneider, R.; Spiess, V.; Cruise Participants Of M56b

    2003-04-01

    A recent high-resolution seismic, echosounder and video survey combined with detailed geological and geochemical sampling of pockmark sites on the Northern Congo Fan was carried out with RV Meteor in November/December 2002 in the frame of the project "CONGO" (BMBF/BEO "Geotechnologien"). These investigations revealed the extensive occurrence of surface and sub-surface gas hydrates as well as characteristic features of fluid venting such as clams (Calyptogena), tube worms (Pogonophera) and huge amounts of authigenic carbonates. In a first approach the patchyness in the occurrence of these features was mapped in relation to pockmark structure and seismic reflectors. Detailed sampling of three pockmarks by gravity corer showed that gas hydrates are present at and close to the sediment surface and often occur as several distinct layers and/or veins intercalated with hemipelagic muds. The depth of the upper boundary of these hydrate-bearing sediments increases from the center towards the edge of the pockmark structures. Pore water concentration profiles of sulfate and methane document the process of anaerobic methane oxidation above the hydrate-bearing layers. For those cores which contained several gas hydrate layers preliminary pore water profiles suggest the occurrence of more than one zone of anaerobic methane oxidation. Authigenic carbonates are found in high abundance, irregularly distributed within the pockmarks close to the sediment surface. These carbonates occur in a wide variety with respect to size, shape, structure and mineralogy. Their formation is associated with high amounts of bicarbonate released by the process of anaerobic methane oxidation. In the gravity cores authigenic carbonates are always present above hydrate-bearing sections. However, the quantities and characteristics of these authigenic minerals in relation to venting and microbial activity as well as to gas hydrate dissociation are not clear yet. Unraveling this relationship will be a major

  3. Updated mitochondrial phylogeny of Pteriomorph and Heterodont Bivalvia, including deep-sea chemosymbiotic Bathymodiolus mussels, vesicomyid clams and the thyasirid clam Conchocele cf. bisecta.

    Science.gov (United States)

    Ozawa, Genki; Shimamura, Shigeru; Takaki, Yoshihiro; Yokobori, Shin-Ichi; Ohara, Yasuhiko; Takishita, Kiyotaka; Maruyama, Tadashi; Fujikura, Katsunori; Yoshida, Takao

    2017-02-01

    The mitochondrial genomes of bivalves have often been used for comparative genomics and for resolving phylogenetic relationships. More than 100 bivalve complete mitochondrial genomes have been sequenced to date. However, few mitochondrial genomes have been reported for deep-sea chemosymbiotic bivalves, which belong to the subclasses Pteriomorphia and Heterodonta. In the present study, we sequenced the mitochondrial genomes of eight deep-sea chemosymbiotic bivalve species: three species of Bathymodiolus mussels (B. japonicus, B. platifrons, and B. septemdierum), four species of vesicomyid clams (Abyssogena mariana, A. phaseoliformis, Isorropodon fossajaponicum, and Phreagena okutanii, all of which were formerly classified in the genus Calyptogena), and one species of thyasirid clam (Conchocele cf. bisecta). With a few exceptions, these mitochondrial genomes contained genes that are typical of metazoans: 13 protein-coding genes, two rRNA genes, and 22 tRNA genes. The major non-coding region with a high A+T content of each genome, which contained tandem repeats and hairpins, was hypothesized to function as a control region. The phylogenetic trees of Pteriomorphia and Heterodonta were reconstructed based on the concatenated sequences of 14 shared genes. Bathymodiolus formed a monophyletic clade with asymbiotic Mytilidae mussels, the vesicomyid clams formed a monophyly that was sister to the Veneridae, and C. cf. bisecta branched basally in the Heterodonta. It is known that the gene orders of mitochondrial genomes vary among bivalves. To examine whether gene order variation exhibits phylogenetic signals, tree topologies based on the minimum number of gene rearrangements were reconstructed for two clades (superfamily Tellinoidea, which includes the Psammobiidae, Semelidae, Solecurtidae, and Tellinidae; and the clade comprising the Myidae, Mactridae, Arcticidae, Vesicomyidae, and Veneridae) with high statistical support in sequence-based phylogenies. The resulting tree

  4. The radiation resistance and cobalt biosorption activity of yeast strains isolated from the Lanyu low-level radioactive waste repository in Taiwan.

    Science.gov (United States)

    Li, Chia-Chin; Chung, Hsiao-Ping; Wen, Hsiao-Wei; Chang, Ching-Tu; Wang, Ya-Ting; Chou, Fong-In

    2015-08-01

    The ubiquitous nature of microbes has made them the pioneers in radionuclides adsorption and transport. In this study, the radiation resistance and nuclide biosorption capacity of microbes isolated from the Lanyu low-level radioactive waste (LLRW) repository in Taiwan was assessed, the evaluation of the possibility of using the isolated strain as biosorbents for (60)Co and Co (II) from contaminated aqueous solution and the potential impact on radionuclides release. The microbial content of solidified waste and broken fragments of containers at the Lanyu LLRW repository reached 10(5) CFU/g. Two yeast strains, Candida guilliermondii (CT1) and Rhodotorula calyptogenae (RT1) were isolated. The radiation dose necessary to reduce the microbial count by one log cycle of CT1 and RT1 was 2.1 and 0.8 kGy, respectively. Both CT1 and RT1 can grow under a radiation field with dose rate of 6.8 Gy/h, about 100 times higher than that on the surface of the LLRW container in Lanyu repository. CT1 and RT1 had the maximum (60)Co biosorption efficiency of 99.7 ± 0.1% and 98.3 ± 0.2%, respectively in (60)Co aqueous solution (700 Bq/mL), and the (60)Co could stably retained for more than 30 days in CT 1. Nearly all of the Co was absorbed and reached equilibrium within 1 h by CT1 and RT1 in the 10 μg/g Co (II) aqueous solution. Biosorption efficiency test showed almost all of the Co (II) was adsorbed by CT1 in 20 μg/g Co (II) aqueous solution, the efficiency of biosorption by RT1 in 10 μg/g of Co (II) was lower. The maximum Co (II) sorption capacity of CT1 and RT1 was 5324.0 ± 349.0 μg/g (dry wt) and 3737.6 ± 86.5 μg/g (dry wt), respectively, in the 20 μg/g Co (II) aqueous solution. Experimental results show that microbial activity was high in the Lanyu LLRW repository in Taiwan. Two isolated yeast strains, CT1 and RT1 have high potential for use as biosorbents for (60)Co and Co (II) from contaminated aqueous solution, on the other hand, but may have the

  5. Carboxysomal carbonic anhydrases: Structure and role in microbial CO2 fixation

    Energy Technology Data Exchange (ETDEWEB)

    Cannon, Gordon C.; Heinhorst, Sabine; Kerfeld, Cheryl A.

    2010-06-23

    Cyanobacteria and some chemoautotrophic bacteria are able to grow in environments with limiting CO2 concentrations by employing a CO2-concentrating mechanism (CCM) that allows them to accumulate inorganic carbon in their cytoplasm to concentrations several orders of magnitude higher than that on the outside. The final step of this process takes place in polyhedral protein microcompartments known as carboxysomes, which contain the majority of the CO2-fixing enzyme, RubisCO. The efficiency of CO2 fixation by the sequestered RubisCO is enhanced by co-localization with a specialized carbonic anhydrase that catalyzes dehydration of the cytoplasmic bicarbonate and ensures saturation of RubisCO with its substrate, CO2. There are two genetically distinct carboxysome types that differ in their protein composition and in the carbonic anhydrase(s) they employ. Here we review the existing information concerning the genomics, structure and enzymology of these uniquely adapted carbonic anhydrases, which are of fundamental importance in the global carbon cycle.

  6. Hydrogen consumption by methanogens on the early Earth

    Science.gov (United States)

    Kral, T. A.; Brink, K. M.; Miller, S. L.; McKay, C. P.; Bada, J. L. (Principal Investigator)

    1998-01-01

    It is possible that the first autotroph used chemical energy rather than light. This could have been the main source of primary production after the initial inventory of abiotic organic material had been depleted. The electron acceptor most readily available for use by this first chemoautotroph would have been CO2. The most abundant electron donor may have been H2 that would have been outgassing from volcanoes at a rate estimated to be as large as 10(12) moles yr-1, as well as from photo-oxidation of Fe+2. We report here that certain methanogens will consume H2 down to partial pressures as low as 4 Pa (4 x 10(-5) atm) with CO2 as the sole carbon source at a rate of 0.7 ng H2 min-1 microgram-1 cell protein. The lower limit of pH2 for growth of methanogens can be understood on the basis that the pH2 needs to be high enough for one ATP to be synthesized per CO2 reduced. The pH2 values needed for growth measured here are consistent with those measured by Stevens and McKinley for growth of methanogens in deep basalt aquifers. H2-consuming autotrophs are likely to have had a profound effect on the chemistry of the early atmosphere and to have been a dominant sink for H2 on the early Earth after life began rather than escape from the Earth's atmosphere to space.

  7. Panspermia-Nature's Exercise in Microbial Cultivation on a Vast Scale

    Science.gov (United States)

    Wainwright, Milton; Aharbi, Sulamain; Alabri, Khalid

    2011-10-01

    Although the idea that life on Earth originated from space has a long history, the modern version of the theory was developed by Hoyle and Wickramasinghe as their cometary theory of panspermia. This theory is discussed here from a microbiologist's point of view, i.e. the prebiotic Earth is seen as a vast culture vessel containing both Earth and space-derived nutrients. This vast culture medium was then, we suggest, naturally inoculated by microbes from space. Life may have arrived as a single organism, but more likely it did so in the form of a mixed "inoculum". Once established in the Earth's culture medium the incoming organisms would have replicated rapidly to from a huge biomass made up of a "mixed culture" of microorganisms representing all of the major metabolic strategies, such as heterotrophs (including oligotrophs), chemoautotrophs and phototrophs. The dominant organisms would arise sequentially depending upon the prevailing physical conditions and to the existence of inter-microbe competition. The incoming mixed inoculum is considered to have originated form comets which, as suggested by Hoyle and Wickramasinghe, provide vast incubators, collectors and deliverers of this inoculum to Earth and the wider cosmos.

  8. Comparison of the effect of salinity on the D/H ratio of fatty acids of heterotrophic and photoautotrophic microorganisms.

    Science.gov (United States)

    Heinzelmann, Sandra M; Chivall, David; M'Boule, Daniela; Sinke-Schoen, Danielle; Villanueva, Laura; Damsté, Jaap S Sinninghe; Schouten, Stefan; van der Meer, Marcel T J

    2015-05-01

    The core metabolism of microorganisms has a major influence on the hydrogen isotopic composition of their fatty acids. Heterotrophic microorganisms produce fatty acids with a deuterium to hydrogen (D/H) ratio either slightly depleted or enriched in D compared to the growth water, while photo- and chemoautotrophic microorganisms produce fatty acids which are heavily depleted in D. However, besides metabolism other biochemical and environmental factors (i.e. biosynthetic pathways, growth phase and temperature) have been shown to affect the D/H ratio of fatty acids, and it is necessary to evaluate the magnitude of these effects compared to that of metabolism. Here, we show that the effect of salinity on the D/H ratio of fatty acids depends on the core metabolism of the microorganism. While fatty acids of the photoautotroph Isochrysis galbana become more enriched in D with increasing salinity (enrichment of 30-40‰ over a range of 25 salinity units), no effect of salinity on the D/H ratio of fatty acids of the heterotrophic Pseudomonas str. LFY10 was observed ((ε)lipid/water of the C16:0 fatty acid of ~120‰ over a range of 10 salinity units). This can likely be explained by the relative contributions of different H and nicotinamide adenine dinucleotide phosphate sources during fatty acid biosynthesis.

  9. Polymersomes Containing Iron Sulfide (FeS) as Primordial Cell Model. For the investigation of energy providing redox reactions

    Science.gov (United States)

    Alpermann, Theodor; Rüdel, Kristin; Rüger, Ronny; Steiniger, Frank; Nietzsche, Sandor; Filiz, Volkan; Förster, Stephan; Fahr, Alfred; Weigand, Wolfgang

    2011-04-01

    According to Wächtershäuser's "Iron-Sulfur-World" one major requirement for the development of life on the prebiotic Earth is compartmentalization. Vesicles spontaneously formed from amphiphilic components containing a specific set of molecules including sulfide minerals may have lead to the first autotrophic prebiotic units. The iron sulfide minerals may have been formed by geological conversions in the environment of deep-sea volcanos (black smokers), which can be observed even today. Wächtershäuser postulated the evolution of chemical pathways as fundamentals of the origin of life on earth. In contrast to the classical Miller-Urey experiment, depending on external energy sources, the "Iron-Sulfur-World" is based on the catalytic and energy reproducing redox system FeS + {H_2}S to FeS{}_2 + {H_2} . The energy release out of this redox reaction (∆RG° = -38 kJ/mol, pH 0) could be the cause for the subsequent synthesis of complex organic molecules and the precondition for the development of more complex units similar to cells known today. Here we show the possibility for precipitating iron sulfide inside vesicles composed of amphiphilic block-copolymers as a model system for a first prebiotic unit. Our findings could be an indication for a chemoautotrophic FeS based origin of life.

  10. Transcriptional response of the archaeal ammonia oxidizer Nitrosopumilus maritimus to low and environmentally relevant ammonia concentrations.

    Science.gov (United States)

    Nakagawa, Tatsunori; Stahl, David A

    2013-11-01

    The ability of chemoautotrophic ammonia-oxidizing archaea to compete for ammonia among marine microorganisms at low ambient concentrations has been in part attributed to their extremely high affinity for ammonia, but as yet there is no mechanistic understanding of supporting metabolism. We examined transcription of selected genes for anabolic functions (CO2 fixation, ammonia transport, and cell wall synthesis) and a central catabolic function (ammonia oxidation) in the thaumarchaeon Nitrosopumilus maritimus SCM1 growing at two ammonia concentrations, as measured by combined ammonia and ammonium, one well above the Km for ammonia oxidation (∼500 μM) and the other well below the Km (ammonia-replete to ammonia-limiting conditions. Transcript levels for ammonia oxidation, CO2 fixation, and one of the ammonia transport genes were approximately the same at high and low ammonia availability. Transcripts for all analyzed genes decreased with time in the complete absence of ammonia, but with various rates of decay. The new steady-state mRNA levels established are presumably more reflective of the natural physiological state of ammonia-oxidizing archaea and offer a reference for interpreting message abundance patterns in the natural environment.

  11. Differential processing of anthropogenic carbon and nitrogen in benthic food webs of A Coruña (NW Spain) traced by stable isotopes

    Science.gov (United States)

    Bode, Antonio; Fernández, Consolación; Mompeán, Carmen; Parra, Santiago; Rozada, Fernando; Valencia-Vila, Joaquín; Viana, Inés G.

    2014-08-01

    In this study the effect of inputs of organic matter and anthropogenic nitrogen at small spatial scales were investigated in the benthos of the Ria of A Coruña (NW Spain) using stable carbon and nitrogen isotopes. This ria is characteristically enriched in nutrients provided either by marine processes (as coastal upwelling) or by urban and agricultural waste. Stable isotope composition in trophic guilds of infaunal benthos revealed spatial differences related to their nutrient inputs. The main difference was the presence of an additional chemoautotrophic food web at the site with a large accumulation of organic matter. The enrichment in heavy nitrogen isotopes observed in most compartments suggests the influence of sewage-derived nitrogen, despite large inputs of marine nitrogen. Macroalgae (Fucus vesiculosus) resulted significantly enriched at the site influenced by estuarine waters. In contrast, no differences were found in mussels (Mytilus galloprovincialis), thus suggesting a major dependence on marine nutrient sources for this species. However, the estimations of anthropogenic influence were largely dependent on assumptions required to model the different contributions of sources. The measurement of stable isotope signatures in various compartments revealed that, despite anthropogenic nutrients are readily incorporated into local food webs, a major influence of natural marine nutrient sources cannot be discarded.

  12. A challenging interpretation of a hexagonally layered protein structure

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Michael C.; Yeates, Todd O., E-mail: yeates@mbi.ucla.edu [UCLA, Los Angeles, CA 90095 (United States)

    2014-01-01

    The authors describe the structure determination of a hexagonally layered protein structure that suffered from a complicated combination of translational non-crystallographic symmetry and hemihedral twinning. This case serves as a reminder that broken crystallographic symmetry resulting from doubling of a unit-cell axis often requires a new choice of origin. The carboxysome is a giant protein complex that acts as a metabolic organelle in cyanobacteria and some chemoautotrophs. Its outer structure is formed by the assembly of thousands of copies of hexameric shell protein subunits into a molecular layer. The structure determination of a CcmK1 shell protein mutant (L11K) from the β-carboxysome of the cyanobacterium Synechocystis PCC6803 led to challenges in structure determination. Twinning, noncrystallographic symmetry and packing of hexameric units in a special arrangement led to initial difficulties in space-group assignment. The correct space group was clarified after initial model refinement revealed additional symmetry. This study provides an instructive example in which broken symmetry requires a new choice of unit-cell origin in order to identify the highest symmetry space group. An additional observation related to the packing arrangement of molecules in this crystal suggests that these hexameric shell proteins might have lower internal symmetry than previously believed.

  13. Isolation of genes (nif/hup cosmids) involved in hydrogenase and nitrogenase activities in Rhizobium japonicum.

    Science.gov (United States)

    Hom, S S; Graham, L A; Maier, R J

    1985-03-01

    Recombinant cosmids containing a Rhizobium japonicum gene involved in both hydrogenase (Hup) and nitrogenase (Nif) activities were isolated. An R. japonicum gene bank utilizing broad-host-range cosmid pLAFR1 was conjugated into Hup- Nif- R. japonicum strain SR139. Transconjugants containing the nif/hup cosmid were identified by their resistance to tetracycline (Tcr) and ability to grow chemoautotrophically (Aut+) with hydrogen. All Tcr Aut+ transconjugants possessed high levels of H2 uptake activity, as determined amperometrically. Moreover, all Hup+ transconjugants tested possessed the ability to reduce acetylene (Nif+) in soybean nodules. Cosmid DNAs from 19 Hup+ transconjugants were transferred to Escherichia coli by transformation. When the cosmids were restricted with EcoRI, 15 of the 19 cosmids had a restriction pattern with 13.2-, 4.0-, 3.0-, and 2.5-kilobase DNA fragments. Six E. coli transformants containing the nif/hup cosmids were conjugated with strain SR139. All strain SR139 transconjugants were Hup+ Nif+. Moreover, one nif/hup cosmid was transferred to 15 other R. japonicum Hup- mutants. Hup+ transconjugants of six of the Hup- mutants appeared at a frequency of 1.0, whereas the transconjugants of the other nine mutants remained Hup-. These results indicate that the nif/hup gene cosmids contain a gene involved in both nitrogenase and hydrogenase activities and at least one and perhaps other hup genes which are exclusively involved in H2 uptake activity.

  14. A paradox resolved: Sulfide acquisition by roots of seep tubeworms sustains net chemoautotrophy

    Science.gov (United States)

    Freytag, John K.; Girguis, Peter R.; Bergquist, Derk C.; Andras, Jason P.; Childress, James J.; Fisher, Charles R.

    2001-01-01

    Vestimentiferan tubeworms, symbiotic with sulfur-oxidizing chemoautotrophic bacteria, dominate many cold-seep sites in the Gulf of Mexico. The most abundant vestimentiferan species at these sites, Lamellibrachia cf. luymesi, grows quite slowly to lengths exceeding 2 meters and lives in excess of 170–250 years. L. cf. luymesi can grow a posterior extension of its tube and tissue, termed a “root,” down into sulfidic sediments below its point of original attachment. This extension can be longer than the anterior portion of the animal. Here we show, using methods optimized for detection of hydrogen sulfide down to 0.1 μM in seawater, that hydrogen sulfide was never detected around the plumes of large cold-seep vestimentiferans and rarely detectable only around the bases of mature aggregations. Respiration experiments, which exposed the root portions of L. cf. luymesi to sulfide concentrations between 51–561 μM, demonstrate that L. cf. luymesi use their roots as a respiratory surface to acquire sulfide at an average rate of 4.1 μmol⋅g−1⋅h−1. Net dissolved inorganic carbon uptake across the plume of the tubeworms was shown to occur in response to exposure of the posterior (root) portion of the worms to sulfide, demonstrating that sulfide acquisition by roots of the seep vestimentiferan L. cf. luymesi can be sufficient to fuel net autotrophic total dissolved inorganic carbon uptake. PMID:11687647

  15. The Biological Deep Sea Hydrothermal Vent as a Model to Study Carbon Dioxide Capturing Enzymes

    Directory of Open Access Journals (Sweden)

    Premila D. Thongbam

    2011-04-01

    Full Text Available Deep sea hydrothermal vents are located along the mid-ocean ridge system, near volcanically active areas, where tectonic plates are moving away from each other. Sea water penetrates the fissures of the volcanic bed and is heated by magma. This heated sea water rises to the surface dissolving large amounts of minerals which provide a source of energy and nutrients to chemoautotrophic organisms. Although this environment is characterized by extreme conditions (high temperature, high pressure, chemical toxicity, acidic pH and absence of photosynthesis a diversity of microorganisms and many animal species are specially adapted to this hostile environment. These organisms have developed a very efficient metabolism for the assimilation of inorganic CO2 from the external environment. In order to develop technology for the capture of carbon dioxide to reduce greenhouse gases in the atmosphere, enzymes involved in CO2 fixation and assimilation might be very useful. This review describes some current research concerning CO2 fixation and assimilation in the deep sea environment and possible biotechnological application of enzymes for carbon dioxide capture.

  16. Phylogeny of 16S rRNA, ribulose 1,5-bisphosphate carboxylase/oxygenase, and adenosine 5'-phosphosulfate reductase genes from gamma- and alphaproteobacterial symbionts in gutless marine worms (oligochaeta) from Bermuda and the Bahamas.

    Science.gov (United States)

    Blazejak, Anna; Kuever, Jan; Erséus, Christer; Amann, Rudolf; Dubilier, Nicole

    2006-08-01

    Gutless oligochaetes are small marine worms that live in obligate associations with bacterial endosymbionts. While symbionts from several host species belonging to the genus Olavius have been described, little is known of the symbionts from the host genus Inanidrilus. In this study, the diversity of bacterial endosymbionts in Inanidrilus leukodermatus from Bermuda and Inanidrilus makropetalos from the Bahamas was investigated using comparative sequence analysis of the 16S rRNA gene and fluorescence in situ hybridization. As in all other gutless oligochaetes examined to date, I. leukodermatus and I. makropetalos harbor large, oval bacteria identified as Gamma 1 symbionts. The presence of genes coding for ribulose-1,5-bisphosphate carboxylase/oxygenase form I (cbbL) and adenosine 5'-phosphosulfate reductase (aprA) supports earlier studies indicating that these symbionts are chemoautotrophic sulfur oxidizers. Alphaproteobacteria, previously identified only in the gutless oligochaete Olavius loisae from the southwest Pacific Ocean, coexist with the Gamma 1 symbionts in both I. leukodermatus and I. makropetalos, with the former harboring four and the latter two alphaproteobacterial phylotypes. The presence of these symbionts in hosts from such geographically distant oceans as the Atlantic and Pacific suggests that symbioses with alphaproteobacterial symbionts may be widespread in gutless oligochaetes. The high phylogenetic diversity of bacterial endosymbionts in two species of the genus Inanidrilus, previously known only from members of the genus Olavius, shows that the stable coexistence of multiple symbionts is a common feature in gutless oligochaetes.

  17. Phylogeny of 16S rRNA, Ribulose 1,5-Bisphosphate Carboxylase/Oxygenase, and Adenosine 5′-Phosphosulfate Reductase Genes from Gamma- and Alphaproteobacterial Symbionts in Gutless Marine Worms (Oligochaeta) from Bermuda and the Bahamas

    Science.gov (United States)

    Blazejak, Anna; Kuever, Jan; Erséus, Christer; Amann, Rudolf; Dubilier, Nicole

    2006-01-01

    Gutless oligochaetes are small marine worms that live in obligate associations with bacterial endosymbionts. While symbionts from several host species belonging to the genus Olavius have been described, little is known of the symbionts from the host genus Inanidrilus. In this study, the diversity of bacterial endosymbionts in Inanidrilus leukodermatus from Bermuda and Inanidrilus makropetalos from the Bahamas was investigated using comparative sequence analysis of the 16S rRNA gene and fluorescence in situ hybridization. As in all other gutless oligochaetes examined to date, I. leukodermatus and I. makropetalos harbor large, oval bacteria identified as Gamma 1 symbionts. The presence of genes coding for ribulose-1,5-bisphosphate carboxylase/oxygenase form I (cbbL) and adenosine 5′-phosphosulfate reductase (aprA) supports earlier studies indicating that these symbionts are chemoautotrophic sulfur oxidizers. Alphaproteobacteria, previously identified only in the gutless oligochaete Olavius loisae from the southwest Pacific Ocean, coexist with the Gamma 1 symbionts in both I. leukodermatus and I. makropetalos, with the former harboring four and the latter two alphaproteobacterial phylotypes. The presence of these symbionts in hosts from such geographically distant oceans as the Atlantic and Pacific suggests that symbioses with alphaproteobacterial symbionts may be widespread in gutless oligochaetes. The high phylogenetic diversity of bacterial endosymbionts in two species of the genus Inanidrilus, previously known only from members of the genus Olavius, shows that the stable coexistence of multiple symbionts is a common feature in gutless oligochaetes. PMID:16885306

  18. Metagenomic Analysis from the Interior of a Speleothem in Tjuv-Ante's Cave, Northern Sweden.

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    Marie Lisandra Zepeda Mendoza

    Full Text Available Speleothems are secondary mineral deposits normally formed by water supersaturated with calcium carbonate percolating into underground caves, and are often associated with low-nutrient and mostly non-phototrophic conditions. Tjuv-Ante's cave is a shallow-depth cave formed by the action of waves, with granite and dolerite as major components, and opal-A and calcite as part of the speleothems, making it a rare kind of cave. We generated two DNA shotgun sequencing metagenomic datasets from the interior of a speleothem from Tjuv-Ante's cave representing areas of old and relatively recent speleothem formation. We used these datasets to perform i an evaluation of the use of these speleothems as past biodiversity archives, ii functional and taxonomic profiling of the speleothem's different formation periods, and iii taxonomic comparison of the metagenomic results to previous microscopic analyses from a nearby speleothem of the same cave. Our analyses confirm the abundance of Actinobacteria and fungi as previously reported by microscopic analyses on this cave, however we also discovered a larger biodiversity. Interestingly, we identified photosynthetic genes, as well as genes related to iron and sulphur metabolism, suggesting the presence of chemoautotrophs. Furthermore, we identified taxa and functions related to biomineralization. However, we could not confidently establish the use of this type of speleothems as biological paleoarchives due to the potential leaching from the outside of the cave and the DNA damage that we propose has been caused by the fungal chemical etching.

  19. Polymersomes containing iron sulfide (FeS) as primordial cell model : for the investigation of energy providing redox reactions.

    Science.gov (United States)

    Alpermann, Theodor; Rüdel, Kristin; Rüger, Ronny; Steiniger, Frank; Nietzsche, Sandor; Filiz, Volkan; Förster, Stephan; Fahr, Alfred; Weigand, Wolfgang

    2011-04-01

    According to Wächtershäuser's "Iron-Sulfur-World" one major requirement for the development of life on the prebiotic Earth is compartmentalization. Vesicles spontaneously formed from amphiphilic components containing a specific set of molecules including sulfide minerals may have lead to the first autotrophic prebiotic units. The iron sulfide minerals may have been formed by geological conversions in the environment of deep-sea volcanos (black smokers), which can be observed even today. Wächtershäuser postulated the evolution of chemical pathways as fundamentals of the origin of life on earth. In contrast to the classical Miller-Urey experiment, depending on external energy sources, the "Iron-Sulfur-World" is based on the catalytic and energy reproducing redox system FeS+H2S-->FeS2+H2. The energy release out of this redox reaction (∆RG°=-38 kJ/mol, pH 0) could be the cause for the subsequent synthesis of complex organic molecules and the precondition for the development of more complex units similar to cells known today. Here we show the possibility for precipitating iron sulfide inside vesicles composed of amphiphilic block-copolymers as a model system for a first prebiotic unit. Our findings could be an indication for a chemoautotrophic FeS based origin of life.

  20. Heterotrophic bicarbonate assimilation is the main process of de novo organic carbon synthesis in hadal zone of the Hellenic Trench, the deepest part of Mediterranean Sea.

    Science.gov (United States)

    Yakimov, Michail M; La Cono, Violetta; Smedile, Francesco; Crisafi, Francesca; Arcadi, Erika; Leonardi, Marcella; Decembrini, Franco; Catalfamo, Maurizio; Bargiela, Rafael; Ferrer, Manuel; Golyshin, Peter N; Giuliano, Laura

    2014-12-01

    Ammonium-oxidizing chemoautotrophic members of Thaumarchaea are proposed to be the key players in the assimilation of bicarbonate in the dark (ABD). However, this process may also involve heterotrophic metabolic pathways, such as fixation of carbon dioxide (CO2) via various anaplerotic reactions. We collected samples from the depth of 4900 m at the Matapan-Vavilov Deep (MVD) station (Hellenic Trench, Eastern Mediterranean) and used the multiphasic approach to study the ABD mediators in this deep-sea ecosystem. At this depth, our analysis indicated the occurrence of actively CO2-fixing heterotrophic microbial assemblages dominated by Gammaproteobacteria with virtually no Thaumarchaea present. [14C]-bicarbonate incorporation experiments combined with shotgun [14C]-proteomic analysis identified a series of proteins of gammaproteobacterial origin. More than quarter of them were closely related with Alteromonas macleodii ‘deep ecotype’ AltDE, the predominant organism in the microbial community of MVD. The present study demonstrated that in the aphotic/hadal zone of the Mediterranean Sea, the assimilation of bicarbonate is associated with both chemolithoauto- and heterotrophic ABD. In some deep-sea areas, the latter may predominantly contribute to the de novo synthesis of organic carbon which points at the important and yet underestimated role heterotrophic bacterial populations can play the in global carbon cycle/sink in the ocean interior.

  1. Linking hydrothermal geochemistry to organismal physiology: physiological versatility in Riftia pachyptila from sedimented and basalt-hosted vents.

    Science.gov (United States)

    Robidart, Julie C; Roque, Annelys; Song, Pengfei; Girguis, Peter R

    2011-01-01

    Much of what is known regarding Riftia pachyptila physiology is based on the wealth of studies of tubeworms living at diffuse flows along the fast-spreading, basalt-hosted East Pacific Rise (EPR). These studies have collectively suggested that Riftia pachyptila and its chemoautotrophic symbionts are physiologically specialized, highly productive associations relying on hydrogen sulfide and oxygen to generate energy for carbon fixation, and the symbiont's nitrate reduction to ammonia for energy and biosynthesis. However, Riftia also flourish in sediment-hosted vents, which are markedly different in geochemistry than basalt-hosted systems. Here we present data from shipboard physiological studies and global quantitative proteomic analyses of Riftia pachyptila trophosome tissue recovered from tubeworms residing in the EPR and the Guaymas basin, a sedimented, hydrothermal vent field. We observed marked differences in symbiont nitrogen metabolism in both the respirometric and proteomic data. The proteomic data further suggest that Riftia associations in Guaymas may utilize different sulfur compounds for energy generation, may have an increased capacity for energy storage, and may play a role in degrading exogenous organic carbon. Together these data reveal that Riftia symbionts are far more physiologically plastic than previously considered, and that--contrary to previous assertions--Riftia do assimilate reduced nitrogen in some habitats. These observations raise new hypotheses regarding adaptations to the geochemical diversity of habitats occupied by Riftia, and the degree to which the environment influences symbiont physiology and evolution.

  2. Variation in the diets of hydrothermal vent gastropods

    Science.gov (United States)

    Govenar, Breea; Fisher, Charles R.; Shank, Timothy M.

    2015-11-01

    A prevailing paradigm of hydrothermal vent ecology is that primary consumers feed on chemoautotrophic bacteria. However, for the purposes of reconstructing vent food webs and for tracking energy flow from the generation of rock and fluid chemistry through primary/ secondary productivity and consumption to the overlying water column, it remains unclear which consumers feed on which bacteria. In paired analyses of carbon and nitrogen tissue stable isotope values with unique 16S rRNA sequences from the stomach contents, we determined that two species of gastropod grazers appear to feed on epsilon-proteobacteria, while two other species have more diverse diets, including one species that consumes alpha-proteobacteria, planctomycetes, and non-green sulfur bacteria. Different carbon fixation pathways used by epsilon- and alpha-proteobacteria may account for the variation in the carbon stable isotope values among the consumers. Furthermore, our results indicate that trophic specialization and niche partitioning may contribute to the distribution and abundance of vent-endemic gastropods and support the hypothesis that consumers in the warmer habitats commonly feed on epsilon-proteobacteria that use the rTCA cycle, while in the cooler habitats they feed on additional bacteria that use the CBB cycle. These results suggest that the phylogenetic and metabolic diversity of free-living bacteria may play an important and previously overlooked role in facilitating species coexistence among primary consumers at hydrothermal vents and other chemosynthesis-based ecosystems.

  3. Caribbean Spiny Lobster Fishery Is Underpinned by Trophic Subsidies from Chemosynthetic Primary Production.

    Science.gov (United States)

    Higgs, Nicholas D; Newton, Jason; Attrill, Martin J

    2016-12-19

    The Caribbean spiny lobster, Panulirus argus, is one of the most valuable fisheries commodities in the Central American region, directly employing 50,000 people and generating >US$450 million per year [1]. This industry is particularly important to small island states such as The Bahamas, which exports more lobster than any other country in the region [1]. Several factors contribute to this disproportionally high productivity, principally the extensive shallow-water banks covered in seagrass meadows [2], where fishermen deploy artificial shelters for the lobsters to supplement scarce reef habitat [3]. The surrounding seabed communities are dominated by lucinid bivalve mollusks that live among the seagrass root system [4, 5]. These clams host chemoautotrophic bacterial symbionts in their gills that synthesize organic matter using reduced sulfur compounds, providing nutrition to their hosts [6]. Recent studies have highlighted the important role of the lucinid clam symbiosis in maintaining the health and productivity of seagrass ecosystems [7, 8], but their biomass also represents a potentially abundant, but as yet unquantified, food source to benthic predators [9]. Here we undertake the first analysis of Caribbean spiny lobster diet using a stable isotope approach (carbon, nitrogen, and sulfur) and show that a significant portion of their food (∼20% on average) is obtained from chemosynthetic primary production in the form of lucinid clams. This nutritional pathway was previously unrecognized in the spiny lobster's diet, and these results are the first empirical evidence that chemosynthetic primary production contributes to the productivity of commercial fisheries stocks.

  4. Food-web structure of seep sediment macrobenthos from the Gulf of Mexico

    Science.gov (United States)

    Demopoulos, Amanda W.J.; Gualtieri, Daniel; Kovacs, Kaitlin

    2010-01-01

    The slope environment of the Gulf of Mexico (GOM) supports dense communities of seep megafaunal invertebrates that rely on endosymbiotic bacteria for nutrition. Seep sediments also contain smaller macrofaunal invertebrates whose nutritional pathways are not well understood. Using stable-isotope analysis, we investigate the utilization of chemosynthetically fixed and methane-derived organic matter by macrofauna. Biological sampling was conducted in three lower-slope GOM seep environs: Green Canyon (GC852, 1428 m), Atwater Valley (AT340, 2230 m), and Alaminos Canyon (AC601, 2384 m). Infaunal delta13C and delta15N exhibited a broad range of values; most infauna appeared to be heterotrophic, although several taxa had very light delta15N and delta13C values, indicating possible reliance on chemoautotrophic symbioses. The lightest delta13C and delta15N values were observed in nematodes (delta13C=-54.6 + or - 0.1 per mil, delta15N=-6.1 + or - 0.2 per mil) and one gastropod (delta13C=-54.1 per mil, delta15N=-1.1 per mil) from Green Canyon. Mixing-model results indicated that sulfur-oxidizing Beggiatoa may be an important food source for seep infauna; the rate of utilization ranged from 60% to 100% at Green Canyon and Atwater Valley. The overall range in isotope values was similar across the three sites, suggesting that biogeochemical processes may be very similar in these geographically distinct areas.

  5. Environmental genomics reveals a single-species ecosystem deep within earth

    Energy Technology Data Exchange (ETDEWEB)

    Chivian, Dylan; Brodie, Eoin L.; Alm, Eric; Culley, David E.; Dehal, Paramvir S.; DeSantis, Todd; Gihring, Thomas M.; Lapidus, Alla; Lin, Li-Hung; Lowry, Stephen R.; Moser, Duane P.; Richardson, Paul; Southam, G.; Wanger, G.; Pratt, L. M.; Andersen, Gary; Hazen, Terry C.; Brockman, Fred J.; Arkin, Adam P.; Onstott, T. C.

    2008-10-10

    DNA from low biodiversity, 3 to 40 myr old, fracture water collected at 2.8 km depth in a South African gold mine was sequenced and assembled into a single, complete genome. This uncultured Gram-positive bacterium, Candidatus Desulforudis audaxviator, is prevalent at depths > 1.5 km in the Witwatersrand Basin and its near-clonal population comprises > 99.9% of the microorganisms inhabiting the fluid phase of this particular fracture. Only 0.0014% of the 2.35 Mb exhibit polymorphism, which is almost 60 fold less than the 0.08% rate found for the unusually homogeneous Leptospirillum group II population present in a single biofilm sample from the Iron Mt. acid mine drainage community. Its genome indicates a motile, sporulating, sulfate (SO42-) reducing, chemoautotrophic thermophile that is capable of fixing its own nitrogen and carbon using machinery shared with archaea. Candidatus Desulforudis audaxviator appears capable of an independent lifestyle well suited to long-term isolation from the photosphere deep within Earth’s crust and offers the first example of a natural ecosystem that has its biological component entirely encoded within a single genome. The homogeneity of this genome is compatible with an ecosystem model in which relatively few generations have occurred since the emergence or isolation of this population. Given the age of the fracture water this would suggest a remarkably slow doubling time.

  6. Major role of microbes in carbon fluxes during Austral winter in the Southern Drake Passage.

    Directory of Open Access Journals (Sweden)

    Maura Manganelli

    Full Text Available Carbon cycling in Southern Ocean is a major issue in climate change, hence the need to understand the role of biota in the regulation of carbon fixation and cycling. Southern Ocean is a heterogeneous system, characterized by a strong seasonality, due to long dark winter. Yet, currently little is known about biogeochemical dynamics during this season, particularly in the deeper part of the ocean. We studied bacterial communities and processes in summer and winter cruises in the southern Drake Passage. Here we show that in winter, when the primary production is greatly reduced, Bacteria and Archaea become the major producers of biogenic particles, at the expense of dissolved organic carbon drawdown. Heterotrophic production and chemoautotrophic CO(2 fixation rates were substantial, also in deep water, and bacterial populations were controlled by protists and viruses. A dynamic food web is also consistent with the observed temporal and spatial variations in archaeal and bacterial communities that might exploit various niches. Thus, Southern Ocean microbial loop may substantially maintain a wintertime food web and system respiration at the expense of summer produced DOC as well as regenerate nutrients and iron. Our findings have important implications for Southern Ocean ecosystem functioning and carbon cycle and its manipulation by iron enrichment to achieve net sequestration of atmospheric CO(2.

  7. An ArsR/SmtB family member is involved in the regulation by arsenic of the arsenite oxidase operon in Thiomonas arsenitoxydans.

    Science.gov (United States)

    Moinier, Danielle; Slyemi, Djamila; Byrne, Deborah; Lignon, Sabrina; Lebrun, Régine; Talla, Emmanuel; Bonnefoy, Violaine

    2014-10-01

    The genetic organization of the aioBA operon, encoding the arsenite oxidase of the moderately acidophilic and facultative chemoautotrophic bacterium Thiomonas arsenitoxydans, is different from that of the aioBA operon in the other arsenite oxidizers, in that it encodes AioF, a metalloprotein belonging to the ArsR/SmtB family. AioF is stabilized by arsenite, arsenate, or antimonite but not molybdate. Arsenic is tightly attached to AioF, likely by cysteine residues. When loaded with arsenite or arsenate, AioF is able to bind specifically to the regulatory region of the aio operon at two distinct positions. In Thiomonas arsenitoxydans, the promoters of aioX and aioB are convergent, suggesting that transcriptional interference occurs. These results indicate that the regulation of the aioBA operon is more complex in Thiomonas arsenitoxydans than in the other aioBA containing arsenite oxidizers and that the arsenic binding protein AioF is involved in this regulation. On the basis of these data, a model to explain the tight control of aioBA expression by arsenic in Thiomonas arsenitoxydans is proposed.

  8. Life at the hyperarid margin: novel bacterial diversity in arid soils of the Atacama Desert, Chile

    Science.gov (United States)

    Neilson, Julia W.; Quade, Jay; Ortiz, Marianyoly; Nelson, William M.; Legatzki, Antje; Tian, Fei; LaComb, Michelle; Betancourt, Julio L.; Wing, Rod A.; Soderlund, Carol A.; Maier, Raina M.

    2012-01-01

    Nearly half the earth's surface is occupied by dryland ecosystems, regions susceptible to reduced states of biological productivity caused by climate fluctuations. Of these regions, arid zones located at the interface between vegetated semiarid regions and biologically unproductive hyperarid zones are considered most vulnerable. The objective of this study was to conduct a deep diversity analysis of bacterial communities in unvegetated arid soils of the Atacama Desert, to characterize community structure and infer the functional potential of these communities based on observed phylogenetic associations. A 454-pyrotag analysis was conducted of three unvegetated arid sites located at the hyperarid-arid margin. The analysis revealed communities with unique bacterial diversity marked by high abundances of novel Actinobacteria and Chloroflexi and low levels of Acidobacteria and Proteobacteria, phyla that are dominant in many biomes. A 16S rRNA gene library of one site revealed the presence of clones with phylogenetic associations to chemoautotrophic taxa able to obtain energy through oxidation of nitrite, carbon monoxide, iron, or sulfur. Thus, soils at the hyperarid margin were found to harbor a wealth of novel bacteria and to support potentially viable communities with phylogenetic associations to non-phototrophic primary producers and bacteria capable of biogeochemical cycling.

  9. Genomic and metabolic diversity of Marine Group I Thaumarchaeota in the mesopelagic of two subtropical gyres.

    Directory of Open Access Journals (Sweden)

    Brandon K Swan

    Full Text Available Marine Group I (MGI Thaumarchaeota are one of the most abundant and cosmopolitan chemoautotrophs within the global dark ocean. To date, no representatives of this archaeal group retrieved from the dark ocean have been successfully cultured. We used single cell genomics to investigate the genomic and metabolic diversity of thaumarchaea within the mesopelagic of the subtropical North Pacific and South Atlantic Ocean. Phylogenetic and metagenomic recruitment analysis revealed that MGI single amplified genomes (SAGs are genetically and biogeographically distinct from existing thaumarchaea cultures obtained from surface waters. Confirming prior studies, we found genes encoding proteins for aerobic ammonia oxidation and the hydrolysis of urea, which may be used for energy production, as well as genes involved in 3-hydroxypropionate/4-hydroxybutyrate and oxidative tricarboxylic acid pathways. A large proportion of protein sequences identified in MGI SAGs were absent in the marine cultures Cenarchaeum symbiosum and Nitrosopumilus maritimus, thus expanding the predicted protein space for this archaeal group. Identifiable genes located on genomic islands with low metagenome recruitment capacity were enriched in cellular defense functions, likely in response to viral infections or grazing. We show that MGI Thaumarchaeota in the dark ocean may have more flexibility in potential energy sources and adaptations to biotic interactions than the existing, surface-ocean cultures.

  10. Lipids of Prokaryotic Origin at the Base of Marine Food Webs

    Directory of Open Access Journals (Sweden)

    Maria José Caramujo

    2012-11-01

    Full Text Available In particular niches of the marine environment, such as abyssal trenches, icy waters and hot vents, the base of the food web is composed of bacteria and archaea that have developed strategies to survive and thrive under the most extreme conditions. Some of these organisms are considered “extremophiles” and modulate the fatty acid composition of their phospholipids to maintain the adequate fluidity of the cellular membrane under cold/hot temperatures, elevated pressure, high/low salinity and pH. Bacterial cells are even able to produce polyunsaturated fatty acids, contrarily to what was considered until the 1990s, helping the regulation of the membrane fluidity triggered by temperature and pressure and providing protection from oxidative stress. In marine ecosystems, bacteria may either act as a sink of carbon, contribute to nutrient recycling to photo-autotrophs or bacterial organic matter may be transferred to other trophic links in aquatic food webs. The present work aims to provide a comprehensive review on lipid production in bacteria and archaea and to discuss how their lipids, of both heterotrophic and chemoautotrophic origin, contribute to marine food webs.

  11. Sulfide, the first inorganic substrate for human cells.

    Science.gov (United States)

    Goubern, Marc; Andriamihaja, Mireille; Nübel, Tobias; Blachier, François; Bouillaud, Frédéric

    2007-06-01

    Hydrogen sulfide (H2S) is produced inside the intestine and is known as a poison that inhibits cellular respiration at the level of cytochrome oxidase. However, sulfide is used as an energetic substrate by many photo- and chemoautotrophic bacteria and by animals such as the lugworm Arenicola marina. The concentrations of sulfide present in their habitats are comparable with those present in the human colon. Using permeabilized colonic cells to which sulfide was added by an infusion pump we show that the maximal respiratory rate of colonocyte mitochondria in presence of sulfide compares with that obtained with succinate or L-alpha-glycerophosphate. This oxidation is accompanied by mitochondrial energization. In contrast, other cell types not naturally exposed to high concentration of sulfide showed much lower oxidation rates. Mitochondria showed a very high affinity for sulfide that permits its use as an energetic substrate at low micromolar concentrations, hence, below the toxic level. However, if the supply of sulfide exceeds the oxidation rate, poisoning renders mitochondria inefficient and our data suggest that an anaerobic mechanism involving partial reversion of Krebs cycle already known in invertebrates takes place. In conclusion, this work provides additional and compelling evidence that sulfide is not only a toxic compound. According to our study, sulfide appears to be the first inorganic substrate for mammalian cells characterized thus far.

  12. Not Just a Poison: Microbes That Derive Energy From Arsenic and Their Linkages to the C, N, and S Cycles.

    Science.gov (United States)

    Falkowski, P. G.; Follows, M.; Fennel, K.; Oremland, R. S.

    2003-12-01

    Elements that are abundant in the Earth's crust and the microbes that derive energy from them have been the focus of much research in geomicrobiology. However, some trace elements also have significant biogeochemical cycles that are mediated by microorganisms, but the wider implications of these phenomena have generally been overlooked. This has been the case for arsenic. Arsenic is a toxicant owing to its action as an analog of its Group VB neighbor phosphorous. However, a surprising finding was that a wide diversity of anaerobic prokaryotes gain energy for growth by using arsenate as their electron acceptor, and that they are broadly distributed in nature. They carry out the dissimilatory reduction of arsenate to arsenite while oxidizing organic matter (or hydrogen). Since the electrochemical potential of the arsenate/arsenite couple is 60 mV, it acts as an oxidant of more reduced species like sulfide (- 220 mV). Some arsenate respirers oxidize sulfide, and in doing so fix CO2 into cellular material. Arsenite can be oxidized back to arsenate by aerobic chemoautotrophic microorganisms, or by anaerobes that use nitrate (440 mv). In addition, heterotrophic arsenate-respirers can carry out the reverse reaction, especially in arsenic rich environments like Mono Lake. The possible evolutionary significance of these phenomena and speculation about their occurrence elsewhere in the Solar System will be discussed.

  13. Deep-biosphere consortium of fungi and prokaryotes in Eocene subseafloor basalts.

    Science.gov (United States)

    Bengtson, S; Ivarsson, M; Astolfo, A; Belivanova, V; Broman, C; Marone, F; Stampanoni, M

    2014-11-01

    The deep biosphere of the subseafloor crust is believed to contain a significant part of Earth's biomass, but because of the difficulties of directly observing the living organisms, its composition and ecology are poorly known. We report here a consortium of fossilized prokaryotic and eukaryotic micro-organisms, occupying cavities in deep-drilled vesicular basalt from the Emperor Seamounts, Pacific Ocean, 67.5 m below seafloor (mbsf). Fungal hyphae provide the framework on which prokaryote-like organisms are suspended like cobwebs and iron-oxidizing bacteria form microstromatolites (Frutexites). The spatial inter-relationships show that the organisms were living at the same time in an integrated fashion, suggesting symbiotic interdependence. The community is contemporaneous with secondary mineralizations of calcite partly filling the cavities. The fungal hyphae frequently extend into the calcite, indicating that they were able to bore into the substrate through mineral dissolution. A symbiotic relationship with chemoautotrophs, as inferred for the observed consortium, may be a pre-requisite for the eukaryotic colonization of crustal rocks. Fossils thus open a window to the extant as well as the ancient deep biosphere.

  14. Dynamics of bacterial communities in rice field soils as affected by different long-term fertilization practices.

    Science.gov (United States)

    Ahn, Jae-Hyung; Lee, Shin Ae; Kim, Jeong Myeong; Kim, Myung-Sook; Song, Jaekyeong; Weon, Hang-Yeon

    2016-11-01

    Fertilization and the response of the soil microbial community to the process significantly affect crop yield and the environment. In this study, the seasonal variation in the bacterial communities in rice field soil subjected to different fertilization treatments for more than 50 years was investigated using 16S rRNA sequencing. The simultaneous application of inorganic fertilizers and rice straw compost (CAPK) maintained the species richness of the bacterial communities at levels higher than that in the case of non-fertilization (NF) and application of inorganic fertilizers only (APK) in the initial period of rice growth. The seasonal variation in the bacterial community structure in the NF and APK plots showed cyclic behavior, suggesting that the effect of season was important; however, no such trend was observed in the CAPK plot. In the CAPK plot, the relative abundances of putative copiotrophs such as Bacteroidetes, Firmicutes, and Proteobacteria were higher and those of putative oligotrophs such as Acidobacteria and Plactomycetes were lower than those in the other plots. The relative abundances of organotrophs with respiratory metabolism, such as Actinobacteria, were lower and those of chemoautotrophs that oxidize reduced iron and sulfur compounds were higher in the CAPK plot, suggesting greater carbon storage in this plot. Increased methane emission and nitrogen deficiency, which were inferred from the higher abundances of Methylocystis and Bradyrhizobium in the CAPK plot, may be a negative effect of rice straw application; thus, a solution for these should be considered to increase the use of renewable resources in agricultural lands.

  15. The stepwise evolution of early life driven by energy conservation.

    Science.gov (United States)

    Ferry, James G; House, Christopher H

    2006-06-01

    Two main theories have emerged for the origin and early evolution of life based on heterotrophic versus chemoautotrophic metabolisms. With the exception of a role for CO, the theories have little common ground. Here we propose an alternative theory for the early evolution of the cell which combines principal features of the widely disparate theories. The theory is based on the extant pathway for conversion of CO to methane and acetate, largely deduced from the genomic analysis of the archaeon Methanosarcina acetivorans. In contrast to current paradigms, we propose that an energy-conservation pathway was the major force which powered and directed the early evolution of the cell. We envision the proposed primitive energy-conservation pathway to have developed sometime after a period of chemical evolution but prior to the establishment of diverse protein-based anaerobic metabolisms. We further propose that energy conservation played the predominant role in the later evolution of anaerobic metabolisms which explains the origin and evolution of extant methanogenic pathways.

  16. Formation of amide bonds without a condensation agent and implications for origin of life.

    Science.gov (United States)

    Keller, M; Blöchl, E; Wächtershäuser, G; Stetter, K O

    1994-04-28

    Amide bonds are of central importance for biochemistry; in the guise of peptide bonds, they form the backbone of proteins. The formation of amide bonds without the assistance of enzymes poses a major challenge for theories of the origin of life. Enzyme-free formation of amide bonds between amino acids has been demonstrated in the presence of condensing agents such as cyanamide. Here we report the formation of amide bonds in aqueous solution in the absence of any condensing agent. We find that the formation of pyrite (FeS2) from FeS and H2S can provide the driving force for reductive acetylation of amino acids with mercaptoacetic acid (HSCH2COOH). The redox energy of pyrite formation permits the activation of the carboxylic acid group, which is converted to a species that reacts readily with amines. This process provides support for the chemo-autotrophic theory for the origin of life, in which pyrite formation supplies the energy source for the first autocatalytic reproduction cycle.

  17. The origin of life and its methodological challenge.

    Science.gov (United States)

    Wächtershäuser, G

    1997-08-21

    The problem of the origin of life is discussed from a methodological point of view as an encounter between the teleological thinking of the historian and the mechanistic thinking of the chemist; and as the Kantian task of replacing teleology by mechanism. It is shown how the Popperian situational logic of historic understanding and the Popperian principle of explanatory power of scientific theories, when jointly applied to biochemistry, lead to a methodology of biochemical retrodiction, whereby common precursor functions are constructed for disparate successor functions. This methodology is exemplified by central tenets of the theory of the chemo-autotrophic origin of life: the proposal of a surface metabolism with a two-dimensional order; the basic polarity of life with negatively charged constituents on positively charged mineral surfaces; the surface-metabolic origin of phosphorylated sugar metabolism and nucleic acids; the origin of membrane lipids and of chemi-osmosis on pyrite surfaces; and the principles of the origin of the genetic machinery. The theory presents the early evolution of life as a process that begins with chemical necessity and winds up in genetic chance.

  18. Serine 363 of a Hydrophobic Region of Archaeal Ribulose 1,5-Bisphosphate Carboxylase/Oxygenase from Archaeoglobus fulgidus and Thermococcus kodakaraensis Affects CO2/O2 Substrate Specificity and Oxygen Sensitivity.

    Directory of Open Access Journals (Sweden)

    Nathan E Kreel

    Full Text Available Archaeal ribulose 1, 5-bisphospate carboxylase/oxygenase (RubisCO is differentiated from other RubisCO enzymes and is classified as a form III enzyme, as opposed to the form I and form II RubisCOs typical of chemoautotrophic bacteria and prokaryotic and eukaryotic phototrophs. The form III enzyme from archaea is particularly interesting as several of these proteins exhibit unusual and reversible sensitivity to molecular oxygen, including the enzyme from Archaeoglobus fulgidus. Previous studies with A. fulgidus RbcL2 had shown the importance of Met-295 in oxygen sensitivity and pointed towards the potential significance of another residue (Ser-363 found in a hydrophobic pocket that is conserved in all RubisCO proteins. In the current study, further structure/function studies have been performed focusing on Ser-363 of A. fulgidus RbcL2; various changes in this and other residues of the hydrophobic pocket point to and definitively establish the importance of Ser-363 with respect to interactions with oxygen. In addition, previous findings had indicated discrepant CO2/O2 specificity determinations of the Thermococcus kodakaraensis RubisCO, a close homolog of A. fulgidus RbcL2. It is shown here that the T. kodakaraensis enzyme exhibits a similar substrate specificity as the A. fulgidus enzyme and is also oxygen sensitive, with equivalent residues involved in oxygen interactions.

  19. Heterotrophic and autotrophic microbial populations in cold perennial springs of the high arctic.

    Science.gov (United States)

    Perreault, Nancy N; Greer, Charles W; Andersen, Dale T; Tille, Stefanie; Lacrampe-Couloume, Georges; Lollar, Barbara Sherwood; Whyte, Lyle G

    2008-11-01

    The saline springs of Gypsum Hill in the Canadian high Arctic are a rare example of cold springs originating from deep groundwater and rising to the surface through thick permafrost. The heterotrophic bacteria and autotrophic sulfur-oxidizing bacteria (up to 40% of the total microbial community) isolated from the spring waters and sediments were classified into four phyla (Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria) based on 16S rRNA gene analysis; heterotrophic isolates were primarily psychrotolerant, salt-tolerant, facultative anaerobes. Some of the isolates contained genes for thiosulfate oxidation (soxB) and anoxygenic photosynthesis (pufM), possibly enabling the strains to better compete in these sulfur-rich environments subject to long periods of illumination in the Arctic summer. Although leucine uptake by the spring water microbial community was low, CO(2) uptake was relatively high under dark incubation, reinforcing the idea that primary production by chemoautotrophs is an important process in the springs. The small amounts of hydrocarbons in gases exsolving from the springs (0.38 to 0.51% CH(4)) were compositionally and isotopically consistent with microbial methanogenesis and possible methanotrophy. Anaerobic heterotrophic sulfur oxidation and aerobic autotrophic sulfur oxidation activities were demonstrated in sediment slurries. Overall, our results describe an active microbial community capable of sustainability in an extreme environment that experiences prolonged periods of continuous light or darkness, low temperatures, and moderate salinity, where life seems to rely on chemolithoautotrophy.

  20. Geochemical Energy for Catabolism and Anabolism in Hydrothermal Systems

    Science.gov (United States)

    Amend, J. P.; McCollom, T. M.; Bach, W.

    2008-12-01

    Chemically reduced deep-sea vent fluids mixed with oxidized seawater can generate redox disequilibria that serve as energy sources for chemolithoautotrophic (catabolism) and biomass synthesis (anabolism) reactions. Numerical models can be used to evaluate Gibbs energies of such processes on the early Earth and in present-day systems. Here, geochemical data from compositionally diverse vent fluids (Lost City, Rainbow, Logatchev, TAG, 21 °N EPR) are combined with several seawater chemistries to yield a wide range of mixed hydrothermal solutions; this is the starting point for our thermodynamic calculations. In ultramafic-hosted hydrothermal systems, such as Rainbow or Lost City, aerobic chemolithotrophic catabolisms (oxidation of H2, FeII, CH4) are the most energy-yielding at low temperatures (catabolic reaction energetics can then be used to put constraints on the amount of primary biomass production. Under putative early Earth conditions, for example, the net chemoautotrophic synthesis of cellular building blocks is thermodynamically most favorable at moderate temperatures (~50°C), where the energy contributions from HCO3- and H+ in cool seawater coupled to the reducing power in hot vent fluid are optimized. At these conditions, and counter to conventional wisdom, the synthesis of amino acids may even yield small amounts of energy.

  1. The specific carbon isotopic compositions of branched and cyclic hydrocarbons from Fushun oil shale

    Institute of Scientific and Technical Information of China (English)

    DUAN Yi; WU Baoxiang; ZHENG Guodong; ZHANG Hui; ZHENG Chaoyang

    2004-01-01

    Various branched and cyclic hydrocarbons are isolated from the Fushun oil shale and their carbon isotopes are determined. The analytical results show that the branched and cyclic hydrocarbons are fully separated from n-alkanes by 5 A Molecular-sieve adduction using long time and cold solvent. The branched and cyclic hydrocarbon fraction obtained by this method is able to satisfy the analytic requests of GC-IRMS. The carbon isotopic compositions of these branched and cyclic hydrocarbons obtained from the sample indicate that they are derived from photoautotrophic algae, chemoautotrophic bacteria (-3.4‰ --39.0‰) and methanotrophic bacteria (-38.4‰--46.3‰). However the long-chain 2-methyl-branched alkanes indicate that their carbon isotopic compositions reflect biological origin from higher plants. The carbon isotopic composition of C30 4-methyl sterane (-22.1‰) is the heaviest in all studied ste- ranes, showing that the carbon source or growth condition for its precursor, dinoflagellate, may be different from that of regular steranes. The variation trend of δ13C values between isomers of hopanes shows that 13C-enriched precursors take precedence in process of their epimerization. Methanotrophic hopanes presented reveal the processes of strong transformation of organic matter and cycling of organic carbon in the water column and early diagenesis of oil shale.

  2. Iron oxide deposits associated with the ectosymbiotic bacteria in the hydrothermal vent shrimp Rimicaris exoculata

    Directory of Open Access Journals (Sweden)

    P. Compère

    2008-09-01

    Full Text Available The Rimicaris exoculata shrimp is considered as a primary consumer that dominates the fauna of most Mid-Atlantic Ridge (MAR hydrothermal ecosystems. These shrimps harbour in their gill chambers an important ectosymbiotic community of chemoautotrophic bacteria associated with iron oxide deposits. The structure and elemental composition of the mineral concretions associated with these bacteria have been investigated by using LM, ESEM, TEM STEM and EDX microanalyses. The nature of the iron oxides in shrimps obtained from the Rainbow vent field has also been determined by Mössbauer spectroscopy. This multidisciplinary approach has revealed that the three layers of mineral crust in the Rimicaris exoculata shrimps consist of large concretions formed by aggregated nanoparticles of two-line ferrihydrite and include other minor elements as Si, Ca, Mg, S and P, probably present as silicates cations, sulphates or phosphates respectively that may contribute to stabilise the ferrihydrite form of iron oxides. TEM-observations on the bacteria have revealed their close interactions with these minerals. Abiotic and biotic precipitation could occur within the gill chamber of Rimicaris exoculata, suggesting the biologically-mediated formation of the iron oxide deposits. The difference of the bacterial density in the three-mineral crust layers could be correlated to the importance of the iron oxide concretions and suggest that the first mineral particles precipitates on the lower layer which could be considered as the most likely location of iron-oxidizing bacteria.

  3. Resource utilization and trophic position of nematodes and harpacticoid copepods in and adjacent to Zostera noltii beds

    Science.gov (United States)

    Vafeiadou, A.-M.; Materatski, P.; Adão, H.; De Troch, M.; Moens, T.

    2014-07-01

    This study examines the resource use and trophic position of nematodes and harpacticoid copepods at the genus/species level in an estuarine food web in Zostera noltii beds and in adjacent bare sediments using the natural abundance of stable carbon and nitrogen isotopes. Microphytobenthos and/or epiphytes are among the main resources of most taxa, but seagrass detritus and sediment particulate organic matter contribute as well to meiobenthos nutrition, which are also available in deeper sediment layers and in unvegetated patches close to seagrass beds. A predominant dependence on chemoautotrophic bacteria was demonstrated for the nematode genus Terschellingia and the copepod family Cletodidae. A predatory feeding mode is illustrated for Paracomesoma and other Comesomatidae, which were previously considered first-level consumers (deposit feeders) according to their buccal morphology. The considerable variation found in both resource use and trophic level among nematode genera from the same feeding type, and even among congeneric nematode species, shows that the interpretation of nematode feeding ecology based purely on mouth morphology should be avoided.

  4. Resource utilization and trophic position of nematodes and harpacticoid copepods in and adjacent to Zostera noltii beds

    Directory of Open Access Journals (Sweden)

    A.-M. Vafeiadou

    2014-01-01

    Full Text Available This study examines the resource use and trophic position of nematodes and harpacticoid copepods at the genus/species level in an estuarine food web in Zostera noltii beds and in adjacent bare sediments, using the natural abundance of stable carbon and nitrogen isotopes. Microphytobenthos is among the main resources of most taxa, but seagrass-associated resources (i.e. seagrass detritus and epiphytes also contribute to meiobenthos nutrition, with seagrass detritus being available also in deeper sediments and in unvegetated patches close to seagrass beds. A predominant dependence on chemoautotrophic bacteria was demonstrated for the nematode genus Terschellingia and the copepod family Cletodidae. A predatory feeding mode is illustrated for Paracomesoma and other Comesomatidae, which were previously considered first-level consumers (deposit feeders according to their buccal morphology. The considerable variation found in both resource use and trophic level among nematode genera from the same feeding type, and even among congeneric nematode species, shows that interpretation of nematode feeding ecology based purely on mouth morphology should be avoided.

  5. New insights into hydrothermal vent processes in the unique shallow-submarine arc-volcano, Kolumbo (Santorini), Greece.

    Science.gov (United States)

    Kilias, Stephanos P; Nomikou, Paraskevi; Papanikolaou, Dimitrios; Polymenakou, Paraskevi N; Godelitsas, Athanasios; Argyraki, Ariadne; Carey, Steven; Gamaletsos, Platon; Mertzimekis, Theo J; Stathopoulou, Eleni; Goettlicher, Joerg; Steininger, Ralph; Betzelou, Konstantina; Livanos, Isidoros; Christakis, Christos; Bell, Katherine Croff; Scoullos, Michael

    2013-01-01

    We report on integrated geomorphological, mineralogical, geochemical and biological investigations of the hydrothermal vent field located on the floor of the density-stratified acidic (pH ~ 5) crater of the Kolumbo shallow-submarine arc-volcano, near Santorini. Kolumbo features rare geodynamic setting at convergent boundaries, where arc-volcanism and seafloor hydrothermal activity are occurring in thinned continental crust. Special focus is given to unique enrichments of polymetallic spires in Sb and Tl (±Hg, As, Au, Ag, Zn) indicating a new hybrid seafloor analogue of epithermal-to-volcanic-hosted-massive-sulphide deposits. Iron microbial-mat analyses reveal dominating ferrihydrite-type phases, and high-proportion of microbial sequences akin to "Nitrosopumilus maritimus", a mesophilic Thaumarchaeota strain capable of chemoautotrophic growth on hydrothermal ammonia and CO2. Our findings highlight that acidic shallow-submarine hydrothermal vents nourish marine ecosystems in which nitrifying Archaea are important and suggest ferrihydrite-type Fe(3+)-(hydrated)-oxyhydroxides in associated low-temperature iron mats are formed by anaerobic Fe(2+)-oxidation, dependent on microbially produced nitrate.

  6. Measurement of organic carbon quantity at chemoautorophic bacterium; Kagaku dokuritsu eiyo saikin ni okeru yuki tansoryo no sokutei ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Tsuda, I.; Kato, K.; Nozaki, K. [Electrotechnical Laboratory, Tsukuba (Japan); Kurokawa, K. [Tokyo University of Agriculture and Technology, Tokyo (Japan)

    1996-10-27

    Described herein is the method for analyzing quantity of organic carbon synthesized by chemoautotrophic bacterium. It is based on the combustion-infrared spectroscopy, which is normally adopted for quantitative analysis of organic carbon. The problems involved in the measurement of organic compounds synthesized by iron-oxidizing bacteria are noise by culture medium components, aging of gas analyzer and contamination with organic compounds from a silicon plug. The measures taken in this study against these problems include comparison of the results with a medium containing iron-oxidizing bacteria with those with a medium free of these bacteria, calibration with the standard solution for each measurement, and replacement of a silicone plug by a silicon cap. Organic carbon is measured by a TOC-5000 analyzer equipped with an automatic sample feeder ASI-5000. Biomass density is determined by the MPN method. It is confirmed that organic carbon quantity is almost in proportion to biomass density, a phenomenon which can be used to determine organic carbon quantity. 7 refs., 6 figs., 1 tab.

  7. Developing a Long-Term Forest Gap Model to Predict the Behavior of California Pines, Oaks, and Cedars Under Climate Change and Other Disturbance Scenarios

    Science.gov (United States)

    Davis, S. L.; Moran, E.

    2015-12-01

    Many predictions about how trees will respond to climate change have been made, but these often rely on extrapolating into the future one of two extremes: purely correlative factors like climate, or purely physiological factors unique to a particular species or plant functional group. We are working towards a model that combines both phenotypic and genotypic traits to better predict responses of trees to climate change. We have worked to parameterize a neighborhood dynamics, individual tree forest-gap model called SORTIE-ND, using open data from both the USDA Forest Service Forest Inventory & Analysis (FIA) datasets in California and 30-yr old permanent plots established by the USGS. We generated individual species factors including stage-specific mortality and growth rates, and species-specific allometric equations for ten species, including Abies concolor, A. magnifica, Calocedrus decurrens, Pinus contorta, P. jeffreyi, P. lambertiana, P. monticola, P. ponderosa, and the two hardwoods Quercus chrysolepis and Q. kelloggii. During this process, we also developed two R packages to aid in parameter development for SORTIE-ND in other ecological systems. MakeMyForests is an R package that parses FIA datasets and calculates parameters based on the state averages of growth, light, and allometric parameters. disperseR is an R package that uses extensive plot data, with individual tree, sapling, and seedling measurements, to calculate finely tuned mortality and growth parameters for SORTIE-ND. Both are freely available on GitHub, and future updates will be available on CRAN. To validate the model, we withheld several plots from the 30-yr USGS data while calculating parameters. We tested for differences between the actual withheld data and the simulated forest data, in basal area, seedling density, seed dispersal, and species composition. The similarity of our model to the real system suggests that the model parameters we generated with our R packages accurately represent

  8. Reforma y modernización del Hotel Alfonso XIII de Sevilla, España

    Directory of Open Access Journals (Sweden)

    Castellón, Carlos Ricardo

    1979-11-01

    Full Text Available This article describes the careful remodeling work of this hotel — a part of the city's history since it was opened in 1926 — a general improvement aimed at making this facility a model in its class, a beautiful building fitted with all the amenities becoming its high luxury classification, a category shared with very few hotels in the country. Special attention has been given to the repair of roofs and walls, renewal of exterior fenestration, grills, artistic glazed tiling, dadoes, coffered ceilings, lamps, floor construction in the banquet hall, plumbing, electric system, air conditioned and providing adequate services. A new magnificent, roomy suite has been incorporated, as well as new classy bathrooms, gardens, roofed car park, and 800 m3 water tank, a bar, a breakfast coffee room, a restaurant in the half-basement with accesses from the inside and the outside, fountains, etc. The refined taste of the architect, the highly specialized work of the contractor and the participation of the qualified Sevillian craftsmen, have all contributed to the neat detailing of the facility and to the highly successful final result.

    Se describe en el articulo la cuidadosa reforma de este Hotel —parte de la Historia de la ciudad, desde su inauguración, en 1926— con la consiguiente modernización general, al objeto de convertirlo en una instalación ejemplar, de gran belleza y dotada de todo el confort que requiere su categoría de gran lujo, condición que comparte con muy pocos hoteles del País. Se ha dedicado especial atención a la consolidación de la cubierta y tabiquería; renovación de la carpintería exterior, verjas, azulejos, zócalos, artesonados, lámparas, forjado del comedor de banquetes, instalaciones de fontanería, electricidad y aire acondicionado; servicios adecuados, etcétera. Se han creado: una magnifica y espaciosa suite, baños de categoría, jardinería, estacionamientos cubiertos, un aljibe de

  9. Estudo Morfológico e Morfométrico da Mama de Ratas em Estro Permanente, Tratadas com Danazol

    Directory of Open Access Journals (Sweden)

    Shida Jorge Yoshinori

    2001-01-01

    Full Text Available Objetivo: estudar os efeitos do danazol sobre a mama da rata em estro permanente. Métodos: os animais foram divididos em três grupos: os do grupo A (n = 12 receberam água (placebo, como grupo controle; os do grupo B (n = 13 foram expostos a 20 mg/kg de danazol por dia; os do grupo C (n = 10 foram expostos a 80 mg/kg de danazol por dia. A droga foi administrada durante 35 dias consecutivos. O estudo microscópico dos cortes avaliou a distribuição ductal e acinar. A histometria da relação ducto/estroma foi feita baseada nos princípios da estereologia, com ocular k-10X da Zeiss, com retículo de integração (Integrationsplatte I-retículo de Weibel de 25 hits, com aumento final de 100 vezes. Para cada lâmina estudada, foram contados 10 campos aleatórios, num total de 250 pontos. O teste aplicado foi a análise de variância por postos de Kruskal-Wallis, para comparar os três grupos em relação ao número médio de alvéolos e ductos nas mamas (alfa = 0,05. Resultados: em todos os grupos, os lóbulos apresentaram ao estudo morfológico alvéolos revestidos com células cúbicas com núcleos na sua porção central ou basal. Pequenas quantidades de material eosinofílico foram observadas em alguns casos na sua luz. À morfometria (magnificação de 100X encontraram-se em média 28,6 ductos/10 campos no grupo A, 28,4 no grupo B e 29,2 no grupo C (análise de Kruskal-Wallis: Hcrit = 0,1. As médias dos números de alvéolos /10 campos foram 5,9 (grupo A, 9,3 (grupo B e 6,5 (grupo C (Kruskal-Wallis Hcrit = 2.9, sem diferença significativa entre os grupos. Conclusão: o danazol não causou nenhuma alteração significante na morfologia e morfometria do epitélio das mamas das ratas em estro permanente.

  10. Comparação entre os sistemas rotatórios Pathfile + Protaper Universal e Twisted Files quanto à preservação da morfologia e ao tempo de trabalho despendido na preparação de canais curvos

    Directory of Open Access Journals (Sweden)

    Daniel Guimarães Pedro Rocha

    Full Text Available INTRODUÇÃO: Instrumentos rotatórios em níquel-titânio (NiTi reduzem erros processuais e o tempo requerido para a preparação do canal radicular. OBJETIVO: Comparar dois sistemas de instrumentação rotatória NiTi - Pathfile + ProTaper Universal e Twisted Files - quanto à capacidade de preservação da morfologia do canal e quanto ao tempo de trabalho necessário para a preparação de canais curvos. MATERIAL E MÉTODO: Os canais mesiais de 32 molares inferiores humanos (com ângulos de curvatura entre 20 e 40 graus foram selecionados para o estudo. As amostras foram divididas aleatoriamente em dois grupos de 16 canais. Os preparos foram realizados por um Endodontista, utilizando-se a combinação dos instrumentos rotatórios Pathfile e ProTaper Universal (grupo PT e os instrumentos rotatórios Twisted Files (grupo TF. Três Endodontistas analisaram imagens com a técnica da dupla radiografia digital, pré e pós-instrumentação, para avaliar se ocorreu transporte apical e/ou aberrações na morfologia dos canais. Por meio de uma análise computadorizada e com o auxílio de magnificação, as imagens inicial e final do canal radicular foram comparadas por meio de sua sobreposição. O teste de odds ratio foi utilizado para a comparação dos níveis de preservação da morfologia do canal, e ANOVA, complementada pelo teste de Tukey, foi utilizada para a comparação dos tempos de preparo. O nível de significância adotado foi de 5%. RESULTADO: Ocorreram desvios na trajetória do canal em ambos os grupos, mas a diferença entre estes não foi significativa. O tempo de trabalho requerido pela combinação dos sistemas Pathfile + ProTaper Universal foi significativamente maior do que o requerido pelo sistema Twisted Files. CONCLUSÃO: Os dois sistemas apresentaram performances semelhantes em relação à preservação da trajetória do canal; no entanto, o tempo de trabalho requerido pelo sistema Twisted Files foi menor.

  11. Life in Inner Space: Subsurface Microbiology Investigations in Underground Research Laboratories and Deep Mines

    Science.gov (United States)

    Sherwood Lollar, B.; Onstott, T. C.; van Heerden, E.; Kieft, T. L.; Ballentine, C. J.

    2012-12-01

    Chemolithotrophic communities, or microbes drawing their energy for life from geologically produced chemical species rather than from photosynthesis, were discovered in the late 1970's at the mid-ocean ridge hydrothermal vents. This discovery sparked a revolution in our understanding of the range of possible mechanisms for sustaining life and hence in our concept of where on this planet life could be found. Since that time, our understanding that life is not simply a thin veneer on the earth's surface but may permeate deep into the subsurface of this planet has evolved rapidly. Serpentinization of ultramafic rocks and alteration of basaltic ocean floor have been invoked as key mechanisms by which geochemical processes of water-rock interaction may provide energy and reducing power for chemoautotrophic microbial communities on the seafloor. In continental settings, H2-utilizing chemoautotrophic microbial communities have been identified in volcanic hot springs, and research in groundwater aquifers suggests that H2-fueled autotrophic microbial ecosystems might be widespread in continental flood basalts. A major gap remains in our understanding of life in the deep, but not so hot, biosphere. Investigations, particularly in the continental or terrestrial deep subsurface, are recognizing that chemosynthetic communities are not restricted to the high temperature hydrothermal vents and springs, but can be sustained under lower temperature regimes by similar types of water-rock reactions, albeit at slower rates. Dissolved H2 produced via radiolysis and/or serpentinization accumulates in hydrogeologically isolated fractures to concentrations up to 7mM - making these terrestrial environments, like the hydrothermal vents, some of the most H2-rich environments on the planet. The implications of this are profound, as it suggests much larger volumes of the Earth's subsurface may be habitable than previously recognized. These finding have impact on exploration for extant or

  12. Microbiological and geochemical dynamics in simulated-heap leaching of a polymetallic sulfide ore.

    Science.gov (United States)

    Wakeman, Kathryn; Auvinen, Hannele; Johnson, D Barrie

    2008-11-01

    The evolution of microbial populations involved in simulated-heap leaching of a polymetallic black schist sulfide ore (from the recently-commissioned Talvivaara mine, Finland) was monitored in aerated packed bed column reactors over a period of 40 weeks. The influence of ore particle size (2-6.5 mm and 6.5-12 mm) on changes in composition of the bioleaching microflora and mineral leaching dynamics in columns was investigated and compared to fine-grain (ore that was bioprocessed in shake flask cultures. Both column reactors and shake flasks were inoculated with 24 different species and strains of mineral-oxidizing and other acidophilic micro-organisms, and maintained at 37 degrees C. Mineral oxidation was most rapid in shake flask cultures, with about 80% of both manganese and nickel and 68% of zinc being leached within 6 weeks, though relatively little of the copper present in the ore was solubilised. The microbial consortium that emerged from the original inoculum was relatively simple in shake flasks, and was dominated by the iron-oxidizing autotroph Leptospirillum ferriphilum, with smaller numbers of Acidimicrobium ferrooxidans, Acidithiobacillus caldus and Leptospirillum ferrooxidans. Both metal recovery and (for the most part) total numbers of prokaryotes were greater in the column reactor containing the medium-grain than that containing the coarse-grain ore. The bioleaching communities in the columns displayed temporal changes in composition and differed radically from those in shake flask cultures. While iron-oxidizing chemoautotrophic bacteria were always the most numerically dominant bacteria in the medium-grain column bioreactor, there were major shifts in the most abundant species present, with the type strain of Acidithiobacillus ferrooxidans dominating in the early phase of the experiment and other bacteria (At. ferrooxidans NO37 and L. ferriphilum) dominating from week 4 to week 40. With the coarse-grain column bioreactor, similar transitions in

  13. Methane-carbon flow into the benthic food web at cold seeps--a case study from the Costa Rica subduction zone.

    Directory of Open Access Journals (Sweden)

    Helge Niemann

    Full Text Available Cold seep ecosystems can support enormous biomasses of free-living and symbiotic chemoautotrophic organisms that get their energy from the oxidation of methane or sulfide. Most of this biomass derives from animals that are associated with bacterial symbionts, which are able to metabolize the chemical resources provided by the seeping fluids. Often these systems also harbor dense accumulations of non-symbiotic megafauna, which can be relevant in exporting chemosynthetically fixed carbon from seeps to the surrounding deep sea. Here we investigated the carbon sources of lithodid crabs (Paralomis sp. feeding on thiotrophic bacterial mats at an active mud volcano at the Costa Rica subduction zone. To evaluate the dietary carbon source of the crabs, we compared the microbial community in stomach contents with surface sediments covered by microbial mats. The stomach content analyses revealed a dominance of epsilonproteobacterial 16S rRNA gene sequences related to the free-living and epibiotic sulfur oxidiser Sulfurovum sp. We also found Sulfurovum sp. as well as members of the genera Arcobacter and Sulfurimonas in mat-covered surface sediments where Epsilonproteobacteria were highly abundant constituting 10% of total cells. Furthermore, we detected substantial amounts of bacterial fatty acids such as i-C15∶0 and C17∶1ω6c with stable carbon isotope compositions as low as -53‰ in the stomach and muscle tissue. These results indicate that the white microbial mats at Mound 12 are comprised of Epsilonproteobacteria and that microbial mat-derived carbon provides an important contribution to the crab's nutrition. In addition, our lipid analyses also suggest that the crabs feed on other (13C-depleted organic matter sources, possibly symbiotic megafauna as well as on photosynthetic carbon sources such as sedimentary detritus.

  14. Influence of increasing dissolved inorganic carbon concentrations and decreasing pH on chemolithoautrophic bacteria from oxic-sulfidic interfaces

    Directory of Open Access Journals (Sweden)

    K. Mammitzsch

    2012-12-01

    Full Text Available Increases in the dissolved inorganic carbon (DIC concentration are expected to cause a decrease in the pH of ocean waters, a process known as ocean acidification. In oxygen-deficient zones this will add to already increased DIC and decreased pH values. It is not known how this might affect microbial communities and microbially mediated processes. In this study, the potential effects of ocean acidification on chemolithoautotrophic prokaryotes of marine oxic-anoxic transition zones were investigated, using the chemoautotrophic denitrifying ε-proteobacterium "Sulfurimonas gotlandica" strain GD1 as a model organism. This and related taxa use reduced sulfur compounds, e.g. sulfide and thiosulfate, as electron donors and were previously shown to be responsible for nitrate removal and sulfide detoxification in redox zones of the Baltic Sea water column but occur also in other oxygen-deficient marine systems. Bacterial cell growth within a broad range of DIC concentrations and pH values was monitored and substrate utilization was determined. The results showed that the DIC saturation concentration for growth was already reached at 800 μM, which is well below in situ DIC levels. The pH optimum was between 6.6 and 8.0. Within a pH range of 6.6–7.1 there was no significant difference in substrate utilization; however, at lower pH values cell growth decreased sharply and cell-specific substrate consumption increased. These findings suggest that a direct effect of ocean acidification, with the predicted changes in pH and DIC, on chemolithoautotrophic bacteria such as "S. gotlandica" str. GD1 is generally not very probable.

  15. Insights into the Structure and Metabolic Function of Microbes That Shape Pelagic Iron-Rich Aggregates (“Iron Snow”)

    Science.gov (United States)

    Lu, Shipeng; Chourey, Karuna; Reiche, Marco; Nietzsche, Sandor; Shah, Manesh B.; Neu, Thomas R.; Hettich, Robert L.

    2013-01-01

    Microbial ferrous iron [Fe(II)] oxidation leads to the formation of iron-rich macroscopic aggregates (“iron snow”) at the redoxcline in a stratified lignite mine lake in east-central Germany. We aimed to identify the abundant Fe-oxidizing and Fe-reducing microorganisms likely to be involved in the formation and transformation of iron snow present in the redoxcline in two basins of the lake that differ in their pH values. Nucleic acid- and lipid-stained microbial cells of various morphologies detected by confocal laser scanning microscopy were homogeneously distributed in all iron snow samples. The dominant iron mineral appeared to be schwertmannite, with shorter needles in the northern than in the central basin samples. Total bacterial 16S rRNA gene copies ranged from 5.0 × 108 copies g (dry weight)−1 in the acidic central lake basin (pH 3.3) to 4.0 × 1010 copies g (dry weight)−1 in the less acidic (pH 5.9) northern basin. Total RNA-based quantitative PCR assigned up to 61% of metabolically active microbial communities to Fe-oxidizing- and Fe-reducing-related bacteria, indicating that iron metabolism was an important metabolic strategy. Molecular identification of abundant groups suggested that iron snow surfaces were formed by chemoautotrophic iron oxidizers, such as Acidimicrobium, Ferrovum, Acidithiobacillus, Thiobacillus, and Chlorobium, in the redoxcline and were rapidly colonized by heterotrophic iron reducers, such as Acidiphilium, Albidiferax-like, and Geobacter-like groups. Metaproteomics yielded 283 different proteins from northern basin iron snow samples, and protein identification provided a glimpse into some of their in situ metabolic processes, such as primary production (CO2 fixation), respiration, motility, and survival strategies. PMID:23645202

  16. Pan-genome analyses identify lineage- and niche-specific markers of evolution and adaptation in Epsilonproteobacteria

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    Ying eZhang

    2014-03-01

    Full Text Available The rapidly increasing availability of complete bacterial genomes has created new opportunities for reconstructing bacterial evolution, but it has also highlighted the difficulty to fully understand the genomic and functional variations occurring among different lineages. Using the class Epsilonproteobacteria as a case study, we investigated the composition, flexibility, and function of its pan-genomes. Models were constructed to extrapolate the expansion of pan-genomes at three different taxonomic levels. The results show that, for Epsilonproteobacteria the seemingly large genome variations among strains of the same species are less noticeable when compared with groups at higher taxonomic ranks, indicating that genome stability is imposed by the potential existence of taxonomic boundaries. The analyses of pan-genomes has also defined a set of universally conserved core genes, based on which a phylogenetic tree was constructed to confirm that thermophilic species from deep-sea hydrothermal vents represent the most ancient lineages of Epsilonproteobacteria. Moreover, by comparing the flexible genome of a chemoautotrophic deep-sea vent species to 1 genomes of species belonging to the same genus, but inhabiting different environments, and 2 genomes of other vent species, but belonging to different genera, we were able to delineate the relative importance of lineage-specific versus niche-specific genes. This result not only emphasizes the overall importance of phylogenetic proximity in shaping the variable part of the genome, but also highlights the adaptive functions of niche-specific genes. Overall, by modeling the expansion of pan-genomes and analyzing core and flexible genes, this study provides snapshots on how the complex processes of gene acquisition, conservation, and removal affect the evolution of different species, and contribute to the metabolic diversity and versatility of Epsilonproteobacteria.

  17. Trophic regions of a hydrothermal plume dispersing away from an ultramafic-hosted vent-system: Von Damm vent-site, Mid-Cayman Rise

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    Bennett, Sarah A.; Coleman, Max; Huber, Julie A.; Reddington, Emily; Kinsey, James C.; McIntyre, Cameron; Seewald, Jeffrey S.; German, Christopher R.

    2013-02-01

    Abstract Deep-sea ultramafic-hosted vent systems have the potential to provide large amounts of metabolic energy to both autotrophic and heterotrophic microorganisms in their dispersing hydrothermal plumes. Such vent-systems release large quantities of hydrogen and methane to the water column, both of which can be exploited by autotrophic microorganisms. Carbon cycling in these hydrothermal plumes may, therefore, have an important influence on open-ocean biogeochemistry. In this study, we investigated an ultramafic-hosted system on the Mid-Cayman Rise, emitting metal-poor and hydrogen sulfide-, methane-, and hydrogen-rich hydrothermal fluids. Total organic carbon concentrations in the plume ranged between 42.1 and 51.1 μM (background = 43.2 ± 0.7 μM (n = 5)) and near-field plume samples with elevated methane concentrations imply the presence of chemoautotrophic primary production and in particular methanotrophy. In parts of the plume characterized by persistent potential temperature anomalies but lacking elevated methane concentrations, we found elevated organic carbon concentrations of up to 51.1 μM, most likely resulting from the presence of heterotrophic communities, their extracellular products and vent larvae. Elevated carbon concentrations up to 47.4 μM were detected even in far-field plume samples. Within the Von Damm hydrothermal plume, we have used our data to hypothesize a microbial food web in which chemoautotrophy supports a heterotrophic community of microorganisms. Such an active microbial food web would provide a source of labile organic carbon to the deep ocean that should be considered in any future studies evaluating sources and sinks of carbon from hydrothermal venting to the deep ocean.

  18. The energetics of the reductive citric acid cycle in the pyrite-pulled surface metabolism in the early stage of evolution.

    Science.gov (United States)

    Kalapos, Miklós Péter

    2007-09-21

    The chemoautotrophic theory concerning the origin of life postulates that a central role is played in the prebiotic chemical machinery by a reductive citric acid cycle operating without enzymes. The crucial point in this scenario is the formation of pyrite from hydrogen sulfide and ferrous sulfide, a reaction suggested to be linked to endergonic reactions, making them exergonic. This mechanism is believed to provide the driving force for the cycle to operate as a carbon dioxide fixation network. The present paper criticizes the thermodynamic calculations and their presentation in the original version of the archaic reductive citric acid cycle [Wächtershäuser, 1990. Evolution of the first metabolic cycles. Proc. Natl Acad. Sci. USA 87, 200-204.]. The most significant differences between the Wächtershäuser hypothesis and the present proposal: Wächtershäuser did not consider individual reactions in his calculations. A particularly questionable feature is the involvement of seven molecules of pyrite which does not emerge as a direct consequence of the chemical reactions presented in the archaic reductive citric acid cycle. The involvement of a considerable number of sulfur-containing organic intermediates as building blocks is also disputed. In the new scheme of the cycle proposed here, less free energy is liberated than hypothesized by Wächtershäuser, but it has the advantages that the free energy changes for the individual reactions can be calculated, the number of pyrite molecules involved in the cycle is reduced, and fewer sulfur-containing intermediates are required for the cycle to operate. In combination with a plausible route for the anaplerotic reactions [Kalapos, 1997a. Possible evolutionary role of methylglyoxalase pathway: anaplerotic route for reductive citric acid cycle of surface metabolists. J. Theor. Biol. 188, 201-206.], this new presentation of the cycle assigns a special meaning to hydrogen sulfide formation in the early stage of biochemical

  19. Insights into the structure and metabolic function of microbes that shape pelagic iron-rich aggregates ("iron snow").

    Science.gov (United States)

    Lu, Shipeng; Chourey, Karuna; Reiche, Marco; Nietzsche, Sandor; Shah, Manesh B; Neu, Thomas R; Hettich, Robert L; Küsel, Kirsten

    2013-07-01

    Microbial ferrous iron [Fe(II)] oxidation leads to the formation of iron-rich macroscopic aggregates ("iron snow") at the redoxcline in a stratified lignite mine lake in east-central Germany. We aimed to identify the abundant Fe-oxidizing and Fe-reducing microorganisms likely to be involved in the formation and transformation of iron snow present in the redoxcline in two basins of the lake that differ in their pH values. Nucleic acid- and lipid-stained microbial cells of various morphologies detected by confocal laser scanning microscopy were homogeneously distributed in all iron snow samples. The dominant iron mineral appeared to be schwertmannite, with shorter needles in the northern than in the central basin samples. Total bacterial 16S rRNA gene copies ranged from 5.0 × 10(8) copies g (dry weight)(-1) in the acidic central lake basin (pH 3.3) to 4.0 × 10(10) copies g (dry weight)(-1) in the less acidic (pH 5.9) northern basin. Total RNA-based quantitative PCR assigned up to 61% of metabolically active microbial communities to Fe-oxidizing- and Fe-reducing-related bacteria, indicating that iron metabolism was an important metabolic strategy. Molecular identification of abundant groups suggested that iron snow surfaces were formed by chemoautotrophic iron oxidizers, such as Acidimicrobium, Ferrovum, Acidithiobacillus, Thiobacillus, and Chlorobium, in the redoxcline and were rapidly colonized by heterotrophic iron reducers, such as Acidiphilium, Albidiferax-like, and Geobacter-like groups. Metaproteomics yielded 283 different proteins from northern basin iron snow samples, and protein identification provided a glimpse into some of their in situ metabolic processes, such as primary production (CO2 fixation), respiration, motility, and survival strategies.

  20. Combined genomic and structural analyses of a cultured magnetotactic bacterium reveals its niche adaptation to a dynamic environment

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    Ana Carolina Vieira Araujo

    2016-10-01

    Full Text Available Abstract Background Magnetotactic bacteria (MTB are a unique group of prokaryotes that have a potentially high impact on global geochemical cycling of significant primary elements because of their metabolic plasticity and the ability to biomineralize iron-rich magnetic particles called magnetosomes. Understanding the genetic composition of the few cultivated MTB along with the unique morphological features of this group of bacteria may provide an important framework for discerning their potential biogeochemical roles in natural environments. Results Genomic and ultrastructural analyses were combined to characterize the cultivated magnetotactic coccus Magnetofaba australis strain IT-1. Cells of this species synthesize a single chain of elongated, cuboctahedral magnetite (Fe3O4 magnetosomes that cause them to align along magnetic field lines while they swim being propelled by two bundles of flagella at velocities up to 300 μm s−1. High-speed microscopy imaging showed the cells move in a straight line rather than in the helical trajectory described for other magnetotactic cocci. Specific genes within the genome of Mf. australis strain IT-1 suggest the strain is capable of nitrogen fixation, sulfur reduction and oxidation, synthesis of intracellular polyphosphate granules and transporting iron with low and high affinity. Mf. australis strain IT-1 and Magnetococcus marinus strain MC-1 are closely related phylogenetically although similarity values between their homologous proteins are not very high. Conclusion Mf. australis strain IT-1 inhabits a constantly changing environment and its complete genome sequence reveals a great metabolic plasticity to deal with these changes. Aside from its chemoautotrophic and chemoheterotrophic metabolism, genomic data indicate the cells are capable of nitrogen fixation, possess high and low affinity iron transporters, and might be capable of reducing and oxidizing a number of sulfur compounds. The relatively

  1. Spatial differences in East scotia ridge hydrothermal vent food webs: influences of chemistry, microbiology and predation on trophodynamics.

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    William D K Reid

    Full Text Available The hydrothermal vents on the East Scotia Ridge are the first to be explored in the Antarctic and are dominated by large peltospiroid gastropods, stalked barnacles (Vulcanolepas sp. and anomuran crabs (Kiwa sp. but their food webs are unknown. Vent fluid and macroconsumer samples were collected at three vent sites (E2, E9N and E9S at distances of tens of metres to hundreds of kilometres apart with contrasting vent fluid chemistries to describe trophic interactions and identify potential carbon fixation pathways using stable isotopes. δ(13C of dissolved inorganic carbon from vent fluids ranged from -4.6‰ to 0.8‰ at E2 and from -4.4‰ to 1.5‰ at E9. The lowest macroconsumer δ(13C was observed in peltospiroid gastropods (-30.0‰ to -31.1‰ and indicated carbon fixation via the Calvin-Benson-Bassham (CBB cycle by endosymbiotic gamma-Proteobacteria. Highest δ(13C occurred in Kiwa sp. (-19.0‰ to -10.5‰, similar to that of the epibionts sampled from their ventral setae. Kiwa sp. δ(13C differed among sites, which were attributed to spatial differences in the epibiont community and the relative contribution of carbon fixed via the reductive tricarboxylic acid (rTCA and CBB cycles assimilated by Kiwa sp. Site differences in carbon fixation pathways were traced into higher trophic levels e.g. a stichasterid asteroid that predates on Kiwa sp. Sponges and anemones at the periphery of E2 assimilated a proportion of epipelagic photosynthetic primary production but this was not observed at E9N. Differences in the δ(13C and δ(34S values of vent macroconsumers between E2 and E9 sites suggest the relative contributions of photosynthetic and chemoautotrophic carbon fixation (rTCA v CBB entering the hydrothermal vent food webs vary between the sites.

  2. Prominent bacterial heterotrophy and sources of 13C-depleted fatty acids to the interior Canada Basin

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    S. R. Shah

    2013-04-01

    Full Text Available In recent decades, the Canada Basin of the Arctic Ocean has experienced rapidly decreasing summer sea ice coverage and freshening of surface waters. It is unclear how these changes translate to depth, particularly as our baseline understanding of organic carbon cycling in the deep basin is limited. In this study, we describe full-depth profiles of the abundance, distribution and carbon isotopic composition of fatty acids from suspended particulate matter at a seasonally ice-free station and a semi-permanently ice-covered station. Fatty acids, along with suspended particulate organic carbon (POC, are more concentrated under ice cover than in ice-free waters. But this influence, apparent at 50 m depth, does not propagate downward below 150 m depth, likely due to the weak biological pump in the central Canada Basin. Branched fatty acids have δ13C values that are similar to suspended POC at all depths and are 13C-enriched compared to even-numbered saturated fatty acids at depths above 3000 m. These are likely to be produced in situ by heterotrophic bacteria incorporating organic carbon that is isotopically similar to total suspended POC. A source of saturated even-numbered fatty acids is also suggested below surface waters which could represent contributions from laterally advected organic carbon or from chemoautotrophic bacteria. At 3000 m depth and below, a greater relative abundance of long-chain (C20–24, branched and unsaturated fatty acids is consistent with a stronger influence of re-suspended sedimentary organic carbon on benthic particulate matter. At these deep depths, two individual fatty acids (C12 and iso-C17 are significantly depleted in 13C, allowing for the possibility that methane oxidizing bacteria contribute fatty acids, either directly to suspended particulate matter or to shallow sediments that are subsequently mobilized and incorporated into suspended particulate matter within the deep basin.

  3. Organic nutrient enrichment in the oligotrophic ocean: Impacts on remineralization, carbon sequestration, and community structure

    Science.gov (United States)

    Mackey, K. R.; Paytan, A.; Post, A. F.

    2007-12-01

    In oligotrophic seas where inorganic nitrogen (N) and phosphorus (P) are below the limits of detection, organic forms of these nutrients may constitute greater than 90% of the total N and P in the euphotic zone. The combined enzymatic activity of phytoplankton and heterotrophic bacteria determines the rate of nutrient remineralization, thereby influencing phytoplankton growth rates and carbon sequestration in these regions. In this study we investigated the effects of fertilization with ammonium (NH4), nitrate (NO3), nitrite (NO2), and phosphate (PO4) as well as various forms of organic N (urea, glycine) and P (deoxyribonucleic acid, 2- aminoethyl phosphonic acid, phytic acid) on the growth and taxonomic composition of the phytoplankton community in the Gulf of Aqaba, Red Sea. The impacts of these changes on nutrient cycling and biological assimilation were also assessed. Organic N additions led to phytoplankton growth when given together with PO4, yielding 2-3 fold increases in chlorophyll a (Chl a) and cell density relative to initial levels. Moreover, our results show that addition of NH4 or NO3 led to accumulation of extra-cellular NO2, suggesting that incomplete assimilatory reduction of NO3 by phytoplankton as well as chemoautotrophic oxidation of NH4 by ammonium oxidizing microbes contributed to NO2 formation. These findings conflict with earlier studies in the Gulf that attributed NO2 formation solely to the phytoplankton community. Organic P additions also led to 2-3 fold increases in Chl a and cell density relative to initial levels when given together with NH4 and NO3. Compared to other P additions, DNA led to the rapid accumulation of extra-cellular PO4, indicating substantial nucleotidase activity in excess of the amount needed to meet phytoplankton growth requirements. These results show the importance and interconnectivity of phytoplankton and heterotrophic bacteria communities in contributing to nutrient cycling and carbon sequestration in

  4. The genome of the intracellular bacterium of the coastal bivalve, Solemya velum: A blueprint for thriving in and out of symbiosis

    Energy Technology Data Exchange (ETDEWEB)

    Dmytrenko, Oleg; Russell, Shelbi L.; Loo, Wesley T.; Fontanez, Kristina M.; Liao, Li; Roeselers, Guus; Sharma, Raghav; Stewart, Frank J.; Newton, Irene L. G.; Woyke, Tanja; Wu, Dongying; Lang, Jenna Morgan; Eisen, Jonathan A.; Cavanaugh, Colleen M.

    2014-09-25

    Background: Symbioses between chemoautotrophic bacteria and marine invertebrates are rare examples of living systems that are virtually independent of photosynthetic primary production. These associations have evolved multiple times in marine habitats, such as deep-sea hydrothermal vents and reducing sediments, characterized by steep gradients of oxygen and reduced chemicals. Due to difficulties associated with maintaining these symbioses in the laboratory and culturing the symbiotic bacteria, studies of chemosynthetic symbioses rely heavily on culture independent methods. The symbiosis between the coastal bivalve, Solemya velum, and its intracellular symbiont is a model for chemosynthetic symbioses given its accessibility in intertidal environments and the ability to maintain it under laboratory conditions. To better understand this symbiosis, the genome of the S. velum endosymbiont was sequenced. Results: Relative to the genomes of obligate symbiotic bacteria, which commonly undergo erosion and reduction, the S. velum symbiont genome was large (2.86 Mb), GC-rich (50.4percent), and contained a large number (78) of mobile genetic elements. Comparative genomics identified sets of genes specific to the chemosynthetic lifestyle and necessary to sustain the symbiosis. In addition, a number of inferred metabolic pathways and cellular processes, including heterotrophy, branched electron transport, and motility, suggested that besides the ability to function as an endosymbiont, the bacterium may have the capacity to live outside the host. Conclusions: The physiological dexterity indicated by the genome substantially improves our understanding of the genetic and metabolic capabilities of the S. velum symbiont and the breadth of niches the partners may inhabit during their lifecycle

  5. Ecogenomic characterization of a marine microorganism belonging to a Firmicutes lineage that is widespread in both terrestrial and oceanic subsurface environments

    Science.gov (United States)

    Jungbluth, S.; Glavina del Rio, T.; Tringe, S. G.; Stepanauskas, R.; Rappe, M. S.

    2015-12-01

    Large-volumes of basalt-hosted fluids from the sediment-covered subseafloor were collected in July 2011 from a horizon extending 29-117 meters below the sediment-rock interface at borehole 1362B, as well as from a deep horizon extending 193-292 meters below the sediment-rock interface at borehole 1362A, which are two of the latest generation of borehole observatories on the Juan de Fuca Ridge flank in the Northeast Pacific Ocean. Environmental DNA was sequenced from one fluid sample collected from each borehole, and a genomic bin related to the terrestrial Candidatus Desulforudis audaxviator lineage within the Firmicutes phylum of bacteria was identified. The near-complete bacterial genome, herein named Candidatus Desulfopertinax inferamarinus, is composed of six scaffolds totaling 1.78 Mbp in length. Despite vast differences in geography and environment of origin, phylogenomic analysis indicate that D. inferamarinus and D. audaxviator form a monophyletic clade to the exclusion of all other sequenced genomes. Similar to its terrestrial relative, the draft genome of the marine D. inferamarinus revealed a motile, sporulating, sulfate-reducing, chemoautotrophic thermophile that is capable of synthesizing all amino acids and fixing inorganic carbon via the Wood-Ljungdahl pathway. Unlike the terrestrial clade, relatively few integrases and transposases were identified. The marine genome described here provides evidence that a life-style adapted to the isolated deep subsurface environment is a general feature of the broader, globally-distributed Desulforudis/Desulfopertinax lineage and provides insight into the adaptations required for microbial life in the marine versus terrestrial deep biospheres.

  6. The Geologic Nitrogen Cycle and its Relationship to Oxygenation of the Early Earth

    Science.gov (United States)

    Catling, D. C.

    2015-12-01

    There is no evidence that the partial pressure of atmospheric nitrogen (pN2) changed greatly in the Phanerozoic but the Precambrian is different. Some suggest that Archean pN2 was higher because it would pressure broaden absorption lines of greenhouse gases and counteract a fainter young Sun [1]. However, analysis of raindrop imprints and fluid inclusions indicate that pN2 was no more than ~0.5-1.2 bar [2, 3] while basalt vesicles show pN2 oxygenation can be understood by comparing modern and ancient fluxes. Today, the long-term N source is from volcanism and metamorphism as well as oxidative weathering of organics. The geologic sink is the burial of organic matter, with minor subduction. But in the Archean, ammonium would have been the dominant N species in seawater. NH4+ substitutes for K+ in seafloor phyllosilicates. NH4+ in silicates can be stable under igneous and metamorphic conditions. Thus, the subduction sink should have been larger. Moreover, the N source from oxidative weathering was absent. With a more efficient geologic sink than today and smaller relative degassing, the steady-state pN2 would be lower. Nitrogen levels can be modeled and with plausible fluxes, Archean pN2 is lower. Once O2 becomes available, nitrifying chemoautotrophs make nitrate and the sink via ammonium declines. A speculative possibility is that oxidized sediments after the Great Oxidation raised the redox state in subduction zones. Higher oxygen fugacity would lead to more N2 degassing [5]. In any case, pN2 changes need not have been monotonic. [1] Goldblatt C. et al. (2009) Nat Geosci 2, 891-896. [2] Som S. M. et al. (2012) Nature 484, 359-362. [3] Marty B. et al. (2013) Science 342, 101-104. [4] Som S. M. et al. (2015), submitted. [5] Mikhail S., Sverjensky D. A. (2014) Nat Geosci 7, 816-819.

  7. A mimicking-of-DNA-methylation-patterns pipeline for overcoming the restriction barrier of bacteria.

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    Guoqiang Zhang

    2012-09-01

    Full Text Available Genetic transformation of bacteria harboring multiple Restriction-Modification (R-M systems is often difficult using conventional methods. Here, we describe a mimicking-of-DNA-methylation-patterns (MoDMP pipeline to address this problem in three difficult-to-transform bacterial strains. Twenty-four putative DNA methyltransferases (MTases from these difficult-to-transform strains were cloned and expressed in an Escherichia coli strain lacking all of the known R-M systems and orphan MTases. Thirteen of these MTases exhibited DNA modification activity in Southwestern dot blot or Liquid Chromatography-Mass Spectrometry (LC-MS assays. The active MTase genes were assembled into three operons using the Saccharomyces cerevisiae DNA assembler and were co-expressed in the E. coli strain lacking known R-M systems and orphan MTases. Thereafter, results from the dot blot and restriction enzyme digestion assays indicated that the DNA methylation patterns of the difficult-to-transform strains are mimicked in these E. coli hosts. The transformation of the Gram-positive Bacillus amyloliquefaciens TA208 and B. cereus ATCC 10987 strains with the shuttle plasmids prepared from MoDMP hosts showed increased efficiencies (up to four orders of magnitude compared to those using the plasmids prepared from the E. coli strain lacking known R-M systems and orphan MTases or its parental strain. Additionally, the gene coding for uracil phosphoribosyltransferase (upp was directly inactivated using non-replicative plasmids prepared from the MoDMP host in B. amyloliquefaciens TA208. Moreover, the Gram-negative chemoautotrophic Nitrobacter hamburgensis strain X14 was transformed and expressed Green Fluorescent Protein (GFP. Finally, the sequence specificities of active MTases were identified by restriction enzyme digestion, making the MoDMP system potentially useful for other strains. The effectiveness of the MoDMP pipeline in different bacterial groups suggests a universal

  8. Methane-Carbon Flow into the Benthic Food Web at Cold Seeps – A Case Study from the Costa Rica Subduction Zone

    Science.gov (United States)

    Niemann, Helge; Linke, Peter; Knittel, Katrin; MacPherson, Enrique; Boetius, Antje; Brückmann, Warner; Larvik, Gaute; Wallmann, Klaus; Schacht, Ulrike; Omoregie, Enoma; Hilton, David; Brown, Kevin; Rehder, Gregor

    2013-01-01

    Cold seep ecosystems can support enormous biomasses of free-living and symbiotic chemoautotrophic organisms that get their energy from the oxidation of methane or sulfide. Most of this biomass derives from animals that are associated with bacterial symbionts, which are able to metabolize the chemical resources provided by the seeping fluids. Often these systems also harbor dense accumulations of non-symbiotic megafauna, which can be relevant in exporting chemosynthetically fixed carbon from seeps to the surrounding deep sea. Here we investigated the carbon sources of lithodid crabs (Paralomis sp.) feeding on thiotrophic bacterial mats at an active mud volcano at the Costa Rica subduction zone. To evaluate the dietary carbon source of the crabs, we compared the microbial community in stomach contents with surface sediments covered by microbial mats. The stomach content analyses revealed a dominance of epsilonproteobacterial 16S rRNA gene sequences related to the free-living and epibiotic sulfur oxidiser Sulfurovum sp. We also found Sulfurovum sp. as well as members of the genera Arcobacter and Sulfurimonas in mat-covered surface sediments where Epsilonproteobacteria were highly abundant constituting 10% of total cells. Furthermore, we detected substantial amounts of bacterial fatty acids such as i-C15∶0 and C17∶1ω6c with stable carbon isotope compositions as low as −53‰ in the stomach and muscle tissue. These results indicate that the white microbial mats at Mound 12 are comprised of Epsilonproteobacteria and that microbial mat-derived carbon provides an important contribution to the crab's nutrition. In addition, our lipid analyses also suggest that the crabs feed on other 13C-depleted organic matter sources, possibly symbiotic megafauna as well as on photosynthetic carbon sources such as sedimentary detritus. PMID:24116017

  9. An extensive reef system at the Amazon River mouth

    Science.gov (United States)

    Moura, Rodrigo L.; Amado-Filho, Gilberto M.; Moraes, Fernando C.; Brasileiro, Poliana S.; Salomon, Paulo S.; Mahiques, Michel M.; Bastos, Alex C.; Almeida, Marcelo G.; Silva, Jomar M.; Araujo, Beatriz F.; Brito, Frederico P.; Rangel, Thiago P.; Oliveira, Braulio C. V.; Bahia, Ricardo G.; Paranhos, Rodolfo P.; Dias, Rodolfo J. S.; Siegle, Eduardo; Figueiredo, Alberto G.; Pereira, Renato C.; Leal, Camille V.; Hajdu, Eduardo; Asp, Nils E.; Gregoracci, Gustavo B.; Neumann-Leitão, Sigrid; Yager, Patricia L.; Francini-Filho, Ronaldo B.; Fróes, Adriana; Campeão, Mariana; Silva, Bruno S.; Moreira, Ana P. B.; Oliveira, Louisi; Soares, Ana C.; Araujo, Lais; Oliveira, Nara L.; Teixeira, João B.; Valle, Rogerio A. B.; Thompson, Cristiane C.; Rezende, Carlos E.; Thompson, Fabiano L.

    2016-01-01

    Large rivers create major gaps in reef distribution along tropical shelves. The Amazon River represents 20% of the global riverine discharge to the ocean, generating up to a 1.3 × 106–km2 plume, and extensive muddy bottoms in the equatorial margin of South America. As a result, a wide area of the tropical North Atlantic is heavily affected in terms of salinity, pH, light penetration, and sedimentation. Such unfavorable conditions were thought to imprint a major gap in Western Atlantic reefs. We present an extensive carbonate system off the Amazon mouth, underneath the river plume. Significant carbonate sedimentation occurred during lowstand sea level, and still occurs in the outer shelf, resulting in complex hard-bottom topography. A permanent near-bottom wedge of ocean water, together with the seasonal nature of the plume’s eastward retroflection, conditions the existence of this extensive (~9500 km2) hard-bottom mosaic. The Amazon reefs transition from accretive to erosional structures and encompass extensive rhodolith beds. Carbonate structures function as a connectivity corridor for wide depth–ranging reef-associated species, being heavily colonized by large sponges and other structure-forming filter feeders that dwell under low light and high levels of particulates. The oxycline between the plume and subplume is associated with chemoautotrophic and anaerobic microbial metabolisms. The system described here provides several insights about the responses of tropical reefs to suboptimal and marginal reef-building conditions, which are accelerating worldwide due to global changes. PMID:27152336

  10. The genome of the intracellular bacterium of the coastal bivalve, Solemya velum: a blueprint for thriving in and out of symbiosis

    Energy Technology Data Exchange (ETDEWEB)

    Dmytrenko, Oleg; Russell, Shelbi L.; Loo, Wesley T.; Fontanez, Kristina M.; Liao, Li; Roeselers, Guus; Sharma, Raghav; Stewart, Frank J.; Newton, Irene LG; Woyke, Tanja; Wu, Dongying; Lang, Jenna; Eisen, Jonathan A.; Cavanaugh, Colleen M.

    2014-01-01

    Background: Symbioses between chemoautotrophic bacteria and marine invertebrates are rare examples of living systems that are virtually independent of photosynthetic primary production. These associations have evolved multiple times in marine habitats, such as deep-sea hydrothermal vents and reducing sediments, characterized by steep gradients of oxygen and reduced chemicals. Due to difficulties associated with maintaining these symbioses in the laboratory and culturing the symbiotic bacteria, studies of chemosynthetic symbioses rely heavily on culture independent methods. The symbiosis between the coastal bivalve, Solemya velum, and its intracellular symbiont is a model for chemosynthetic symbioses given its accessibility in intertidal environments and the ability to maintain it under laboratory conditions. To better understand this symbiosis, the genome of the S. velum endosymbiont was sequenced. Results: Relative to the genomes of obligate symbiotic bacteria, which commonly undergo erosion and reduction, the S. velum symbiont genome was large (2.86 Mb), GC-rich (50.4percent), and contained a large number (78) of mobile genetic elements. Comparative genomics identified sets of genes specific to the chemosynthetic lifestyle and necessary to sustain the symbiosis. In addition, a number of inferred metabolic pathways and cellular processes, including heterotrophy, branched electron transport, and motility, suggested that besides the ability to function as an endosymbiont, the bacterium may have the capacity to live outside the host. Conclusions: The physiological dexterity indicated by the genome substantially improves our understanding of the genetic and metabolic capabilities of the S. velum symbiont and the breadth of niches the partners may inhabit during their lifecycle

  11. Deep fracture fluids isolated in the crust since the Precambrian era.

    Science.gov (United States)

    Holland, G; Lollar, B Sherwood; Li, L; Lacrampe-Couloume, G; Slater, G F; Ballentine, C J

    2013-05-16

    Fluids trapped as inclusions within minerals can be billions of years old and preserve a record of the fluid chemistry and environment at the time of mineralization. Aqueous fluids that have had a similar residence time at mineral interfaces and in fractures (fracture fluids) have not been previously identified. Expulsion of fracture fluids from basement systems with low connectivity occurs through deformation and fracturing of the brittle crust. The fractal nature of this process must, at some scale, preserve pockets of interconnected fluid from the earliest crustal history. In one such system, 2.8 kilometres below the surface in a South African gold mine, extant chemoautotrophic microbes have been identified in fluids isolated from the photosphere on timescales of tens of millions of years. Deep fracture fluids with similar chemistry have been found in a mine in the Timmins, Ontario, area of the Canadian Precambrian Shield. Here we show that excesses of (124)Xe, (126)Xe and (128)Xe in the Timmins mine fluids can be linked to xenon isotope changes in the ancient atmosphere and used to calculate a minimum mean residence time for this fluid of about 1.5 billion years. Further evidence of an ancient fluid system is found in (129)Xe excesses that, owing to the absence of any identifiable mantle input, are probably sourced in sediments and extracted by fluid migration processes operating during or shortly after mineralization at around 2.64 billion years ago. We also provide closed-system radiogenic noble-gas ((4)He, (21)Ne, (40)Ar, (136)Xe) residence times. Together, the different noble gases show that ancient pockets of water can survive the crustal fracturing process and remain in the crust for billions of years.

  12. High taurine levels in the Solemya velum symbiosis.

    Science.gov (United States)

    Conway, N M; McDowell Capuzzo, J E

    1992-05-01

    1. To compare biochemical differences between bivalves with and without endosymbiotic chemoautotrophic bacteria, specimens of Solemya velum, a bivalve species known to contain bacterial endosymbionts, and the symbiont-free soft-shelled clam Mya arenaria, were collected from the same subtidal reducing sediments during October and November 1988. 2. Total and free amino acid compositions were determined for both species. Protein-bound amino acids were calculated as the difference between total and free amino acids. In addition, stable isotope ratios of the total and free amino acids of each species were measured to determine potential sources for these molecules. 3. Both species had similar total hydrolyzable- and protein-bound amino acid compositions; approximately 50% of the protein-bound amino acids were essential amino acids. In S. velum, the small size of the digestive system suggests that these amino acids are probably synthesized by the endosymbiotic bacteria and translocated to the animal tissue. The delta 13C and delta 15N ratios of the amino acids are very similar to the isotope ratios previously found in both the endosymbionts and whole tissues of S. velum. The relative and absolute amounts of free amino acids are very different in the two species. In S. velum, the absolute concentrations of taurine, a sulfur-containing amino acid, were greater than the total free amino acid concentrations found in other bivalves. 4. The delta 34S ratios of the free amino acids of S. velum, which were predominantly composed of taurine, were extremely negative (-17.2/1000) suggesting that taurine is synthesized using sulfur originally derived from external reduced sulfur sources, such as pore water sulfides. The possible roles for taurine in this animal-bacteria symbiosis are discussed.

  13. Cold seep communities in the deep eastern Mediterranean Sea: composition, symbiosis and spatial distribution on mud volcanoes

    Science.gov (United States)

    Olu-Le Roy, Karine; Sibuet, Myriam; Fiala-Médioni, Aline; Gofas, Serge; Salas, Carmen; Mariotti, André; Foucher, Jean-Paul; Woodside, John

    2004-12-01

    Two mud volcano fields were explored during the French-Dutch MEDINAUT cruise (1998) with the submersible NAUTILE, one south of Crete along the Mediteranean Ridge at about 2000 m depth (Olimpi mud field) and the other south of Turkey between 1700 and 2000 m depth (Anaximander mud field) where high methane concentrations were measured. Chemosynthetic communities were observed and sampled on six mud volcanoes and along a fault scarp. The communities were dominated by bivalves of particularly small size, belonging to families commonly found at seeps (Mytilidae, Vesicomyidae, Thyasiridae) and to Lucinidae mostly encountered in littoral sulfide-rich sediments and at the shallowest seeps. Siboglinid polychaetes including a large vestimentiferan Lamellibrachia sp. were also associated. At least four bivalve species and one siboglinid are associated with symbiotic chemoautotrophic bacteria, as evidenced by Transmission Electronic Microscopy and isotopic ratio measurements. Among the bivalves, a mytilid harbors both methanotrophic and sulfide-oxidizing bacteria. Video spatial analysis of the community distribution on three volcanoes shows that dense bivalve shell accumulations (mainly lucinids) spread over large areas, from 10% to 38% of the explored areas (2500-15000 m 2) on the different volcanoes. Lamellibrachia sp. had different spatial distribution and variable density in the two mud volcano fields, apparently related with higher methane fluxes in the Anaximander volcanoes and maybe with the instability due to brines in the Olimpi area. The abundance and richness of the observed chemosynthetic fauna and the size of some of the species contrast with the poverty of the deep eastern Mediterranean. The presence of a specialized fauna, with some mollusk genera and species shared with other reduced environments of the Mediterranean, but not dominated by the large bivalves usually found at seeps, is discussed.

  14. Drilling effect on subsurface microbial community structure in groundwater from the -250 m gallery at the Horonobe Underground Research Laboratory, Japan

    Science.gov (United States)

    Ise, K.; Amano, Y.; Sasaki, Y.; Yoshikawa, H.

    2014-12-01

    The deep geological disposal system is regarded as the most secure and practical disposal method of high-level radioactive waste in the world. In this disposal system, preservation of reducing condition is one of the key requirements, because most of radionuclides have low solubilities in such condition. However, the host rocks near the shafts and galleries would be affected by oxidization during the construction and operation period of a repository (for about 50 years). Therefore, the recovery of reducing condition after closing the repository should be verified. During the recovery processes, it is considered that microbial activities play important roles, but the mechanisms are poorly understood. In this study, we monitored the changes in microbial communities by molecular method to evaluate microbial response toward the oxygen stress. The groundwater samples were collected from a borehole of 250 m depth at the Horonobe Underground Research Laboratory, for two years immediately after drilling of a borehole without any contamination as much as possible. Immediately after drilling of the borehole, the phylotype related to Arcobacter spp. was dominated about 65 % of the total clone library. Arcobacter spp. is known as sulfide oxidizer and which can growth chemoautotrophically. Half a year later, the phylotype related to Azoarcus spp. and Pseudomonas spp. known as nitrate reducing bacteria increased, instead of the phylotype related to Arcobacter spp. One year later, in addition to nitrate reducing bacteria, phylotype related to Dethiobacterspp. known as thiosulfate reducing bacteria was dominantly detected. Two years later, most of detected clones were related to uncultured species such as candidate division WS6 and JS1 which are detected frequently in deep-sea sediments. Our results indicate that these redox sequential reactions could contribute to the recovery and maintenance of reducing conditions and provide a conceptual model for evaluating the capacity to

  15. Trophic ecology and vertical patterns of carbon and nitrogen stable isotopes in zooplankton from oxygen minimum zone regions

    Science.gov (United States)

    Williams, Rebecca L.; Wakeham, Stuart; McKinney, Rick; Wishner, Karen F.

    2014-08-01

    The unique physical and biogeochemical characteristics of oxygen minimum zones (OMZs) influence plankton ecology, including zooplankton trophic webs. Using carbon and nitrogen stable isotopes, this study examined zooplankton trophic webs in the Eastern Tropical North Pacific (ETNP) OMZ. δ13C values were used to indicate zooplankton food sources, and δ15N values were used to indicate zooplankton trophic position and nitrogen cycle pathways. Vertically stratified MOCNESS net tows collected zooplankton from 0 to 1000 m at two stations along a north-south transect in the ETNP during 2007 and 2008, the Tehuantepec Bowl and the Costa Rica Dome. Zooplankton samples were separated into four size fractions for stable isotope analyses. Particulate organic matter (POM), assumed to represent a primary food source for zooplankton, was collected with McLane large volume in situ pumps. The isotopic composition and trophic ecology of the ETNP zooplankton community had distinct spatial and vertical patterns influenced by OMZ structure. The most pronounced vertical isotope gradients occurred near the upper and lower OMZ oxyclines. Material with lower δ13C values was apparently produced in the upper oxycline, possibly by chemoautotrophic microbes, and was subsequently consumed by zooplankton. Between-station differences in δ15N values suggested that different nitrogen cycle processes were dominant at the two locations, which influenced the isotopic characteristics of the zooplankton community. A strong depth gradient in zooplankton δ15N values in the lower oxycline suggested an increase in trophic cycling just below the core of the OMZ. Shallow POM (0-110 m) was likely the most important food source for mixed layer, upper oxycline, and OMZ core zooplankton, while deep POM was an important food source for most lower oxycline zooplankton (except for samples dominated by the seasonally migrating copepod Eucalanus inermis). There was no consistent isotopic progression among the four

  16. Avaliação de Sistema de Leitura Portátil (SLP para baixa visão desenvolvido no Brasil Evaluation of System Portable Reading (SPR for low vision developed in Brazil

    Directory of Open Access Journals (Sweden)

    Vagner Rogério dos Santos

    2009-10-01

    Full Text Available OBJETIVO: A proposta deste estudo é avaliar a eficácia e eficiência em uma série de casos do protótipo de um equipamento nacional de magnificação para leitura. MÉTODOS: Participaram deste estudo 30 pacientes na faixa etária entre 9 e 80 anos (17 do sexo masculino. Foi desenvolvido um aparelho portátil, patenteado pela UNIFESP (PI#020050145260, com um sistema de captura de imagens acoplado a um monitor de 5,6 polegadas proporcionando um aumento de 15 X. Foram analisadas a eficácia da acuidade visual e a eficiência de leitura após a utilização do protótipo proposto. RESULTADOS: Seis pacientes (20% apresentaram AV 8M, 12 pacientes (40% apresentaram AV 6M, 7 pacientes (23,3% apresentaram 5 M, 5 pacientes (16,7% apresentaram 4M. A média de acuidade visual antes da utilização do SLP medida pela tabela LHNV-1 logMAR foi de 5,75M e após a utilização 100% dos pacientes atingiram a eficácia de AV J1. CONCLUSÃO: O protótipo do SLP mostrou-se um recurso alternativo no processo de inclusão social das pessoas com baixa visão com diferentes níveis de resíduo visual. Também pode proporcionar incentivo psicológico, permitir conforto, mobilidade e independência àqueles que necessitam de uma leitura mais prolongada e maior distância de trabalho.PURPOSE: The proposal of this study is to test and to validate as the effectiveness and efficiency in a series of cases the prototype of a national equipment of magnification to reading. METHODS: A recently developed of equipment of magnification (patent pending Brazilian Institutte of Industrial Property # 020050145260 was tested in a group of 30 patients (age range 9 to 80 years, 17 males. A portable apparatus was developed with a system of capture of images coupled with a 5,6 inch monitor, providing an increase of 15 X. The effectiveness of the visual acuity and the reading efficiency were analyzed after the use of the proposed prototype. RESULTS: Six patients (20% presented AV 8M, 12

  17. Superposição automatizada de modelos tomográficos tridimensionais em cirurgia ortognática Superimposition of 3D cone-beam CT models in orthognathic surgery

    Directory of Open Access Journals (Sweden)

    Alexandre Trindade Simões da Motta

    2010-04-01

    Full Text Available INTRODUÇÃO: as limitações na avaliação quantitativa e qualitativa de deslocamentos cirúrgicos pelos métodos bidimensionais podem ser superadas através de tomografias volumétricas e ferramentas de imagens tridimensionais. OBJETIVOS: a metodologia descrita neste trabalho permite avaliar as mudanças nas posições de côndilos, ramos, mento, maxila e da dentição após a cirurgia ortognática através de tomografias computadorizadas de feixe cônico (Cone Beam Computed Tomography, CBCT antes e após o procedimento cirúrgico. MÉTODOS: são construídos modelos 3D que possibilitam superposições tendo a base do crânio pré-cirúrgica como referência, utilizando-se um método automático que identifica e compara a escala de cinza dos voxels de duas estruturas tridimensionais, eliminando a necessidade do operador marcar os pontos anatômicos. Então, as distâncias entre as superfícies anatômicas são computadas, no mesmo indivíduo, entre as duas fases. A avaliação das direções de deslocamento das estruturas é determinada visualmente pelos métodos de mapas coloridos e de semitransparências. CONCLUSÕES: conclui-se que a metodologia apresentada, que utiliza softwares de domínio público, mostra vantagens na avaliação longitudinal de pacientes ortocirúrgicos, quando comparada aos métodos radiográficos convencionais, uma vez que as imagens geradas não apresentam magnificações ou sobreposições de estruturas e a maioria dos passos são automatizados, o que torna os procedimentos de mensuração mais precisos, além de disponibilizar uma maior quantidade de informações ao clínico ou pesquisador.INTRODUCTION: Limitations of 2D quantitative and qualitative evaluation of surgical displacements can be overcome by CBCT and three-dimensional imaging tools. OBJECTIVES: The method described in this study allows the assessment of changes in the condyles, rami, chin, maxilla and dentition by the comparison of CBCT scans before

  18. Caracterização físico-química do enxerto de osso bovino liofilizado Physicochemical characterization of lyophilized bovine bone grafts

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    Carlos Roberto Galia

    2011-01-01

    Full Text Available OBJETIVO: Avaliar as características físico-químicas do enxerto bovino liofilizado manufaturado em escala semi-industrial (OrthoGen, Baumer S/A* de acordo com protocolo previamente desenvolvido pelos autores. MÉTODOS: A caracterização do enxerto de osso bovino liofilizado foi feita por meio de microscopia eletrônica de varredura (MEV, energy dispersive spectroscopy (EDS, difratometria de raios-X, análise por termogravimetria, análise de calorimetria exploratória diferencial (DSC e espectroscopia por infravermelho Fourier-transform (FT-IR. RESULTADOS: Ca foi o principal componente (60% encontrado nas amostras, seguido por P (28% e O (5%. O tamanho médio (dp dos poros foi 316µm (146,7, variando de 91,2 a 497,8µm, e 333,5µm (304,8, variando de 87,2 a 963,9µm com 50x e 150x magnificação, respectivamente. Picos de hidroxiapatita foram a 26ºC e 32ºC, e perda de massa foi observada entre 250ºC e 640ºC, correspondendo material orgânico e água. Duas transições de temperatura (45,67°C e 91,89°C mostraram desnaturação de colágeno tipo I e desidratação da hidroxiapatita. CONCLUSÃO: A avaliação físico-química do enxerto de osso bovino liofilizado, de acordo com o protocolo desenvolvido em escala semi-industrial, confirma que este produto apresenta excelente biocompatibilidade, com características semelhantes ao osso in natura.OBJECTIVE: To evaluate the physicochemical characteristics of lyophilized bovine grafts manufactured on a semi-industrial scale (Orthogen; Baumer S/A* in accordance with a protocol previously developed by the authors. METHODS: The lyophilized bovine bone grafts were characterized by means of scanning electron microscopy (SEM, energy dispersive spectroscopy (EDS, X-ray diffractometry (XRD, thermogravimetric (TG analysis, differential exploratory scanning calorimetry (DSC and Fourier-transform infrared (FT-IR spectroscopy. RESULTS: Ca was the main component (60% found in the samples, followed by P (28

  19. One-bottle adhesives: in vitro analysis of solvent volatilization and sealing ability Adesivos de frasco único: análise in vitro da volatilização do solvente e do selamento marginal

    Directory of Open Access Journals (Sweden)

    Fábio Garcia Lima

    2005-12-01

    inicial (PI e, após 10 min, seu peso final (PF. A razão PI/PF foi utilizada para determinar a taxa de volatilização do solvente. Os frascos com os maiores níveis de evaporação (SB Controle e PB Controle e com os menores níveis de evaporação (SB Teste e PB Teste foram aplicados em restaurações Classe V com margens em dentina. Os espécimes foram termociclados e imersos em solução de fucsina básica a 0,5%. A penetração do corante foi avaliada sob magnificação e os dados foram submetidos ao teste de Kruskal-Wallis. A volatilização do solvente foi mais rápida para o adesivo à base de acetona. As razões PI/PF variaram de 1,239 a 1,515 para SB e de 3,488 a 6,476 para PB. PB-Controle e SB-Controle exibiram vedamento similar. Os maiores escores de penetração foram encontrados para o PB-Teste (p < 0,05. Os resultados indicam que a habilidade de selamento pode ser afetada pela repetida utilização dos frascos de adesivo à base de acetona.

  20. 现存蜉蝣翅基纵脉走向及愈合模式(昆虫纲:蜉蝣目)%The bracing and fusing pattern of longitudinal veins at base in living mayflies (Insecta: Ephemeroptera)

    Institute of Scientific and Technical Information of China (English)

    周长发

    2007-01-01

    The bracing and merging pattern of basal longitudinal veins plays an important role in phylogeny reconstruction within Pterygota. Unfortunately, the basal venation pattern of living mayflies has changed from the ancestral state in most species, but in very rare cases, the origins of some longitudinal vein bases are preserved and visible. The wing base of Siphluriscus chinensis has an independent subcostal brace, partial stem of the media, visible stem of the cubitus, and indications of the origins of MA and Rs. This kind of wing base plus those of Ephemera rufomaculata and Chromarcys magnifica show the venation groundplan of modern Ephemeroptera (stem of M parallel to or fused with R basally, MA and Rs fused together for certain distance then separate, Cu independent at base).This pattern seems close to that of Neoptera while different from Odonata. In the latter, the M fused with Cu basally.The hypothesized function of subcostal brace in mayflies is to strengthen the connection between distantly separated longitudinal veins because of sclerite plate at radius vein base. This hypothesis also can be used to explain complicated and unique venation of dragonfly.%有翅昆虫翅基纵脉的走向及愈合模式在系统发育重建中占有重要地位.然而,现存蜉蝣翅基纵脉的走向及愈合状况在大部分种类变化极大,无法推测其原始状况,只在极少数种类保留有部分可见残迹.中国拟短丝蜉Siphluriscus chinensis的翅基保留有独立的亚前缘脉弓、部分中脉M和肘脉Cu主干以及前中脉MA及径分脉Rs的走向痕迹.据此并结合红斑蜉Ephemera rufomaculata和大网脉蜉Chromarcys magnifica翅基的相关特征,本文提出了蜉蝣目主要纵脉基部走向及愈合的基本模式,其要点有:中脉主干在基部与径脉主干独自发出后先接近或愈合后又分离、它们各自分成两支后的前中脉及径分脉又先愈合再分离、肘脉始终独立.这种中脉与径脉先接近或愈

  1. Avaliação da espessura da camada de fibras nervosas da retina e mácula em pacientes com ambliopia Thickness of the retinal nerve fiber layer, macular thickness, in patients with amblyopia

    Directory of Open Access Journals (Sweden)

    Juliana Mitre

    2010-02-01

    Full Text Available OBJETIVO: Avaliar a espessura da camada de fibras nervosas da retina em olhos amblíopes e comparar com olhos normais e certificar se há correlação com a redução da acuidade visual. Além disso, este estudo se propõe avaliar a eficácia e eficiência em uma série de casos do protótipo de um equipamento nacional de magnificação para leitura. MÉTODOS: Participaram deste estudo 30 pacientes na faixa etária entre 9 e 80 anos (17 do sexo masculino. Foi desenvolvido um aparelho portátil, patenteado pela Unifesp (PI#020050145260, com um sistema de captura de imagens acoplado a um monitor de 5,6 polegadas proporcionando um aumento de 15 x. Foram analisadas a eficácia da acuidade visual e a eficiência de leitura após a utilização do protótipo proposto. RESULTADOS: Seis pacientes (20% apresentaram AV 8M, 12 pacientes (40% apresentaram AV 6M, 7 pacientes (23,3% apresentaram 5 M, 5 pacientes (16,7% apresentaram 4M. A média de acuidade visual antes da utilização do SLP medida pela tabela LHNV-1 logMAR foi de 5,75M e após a utilização 100% dos pacientes atingiram a eficácia de AV J1. CONCLUSÃO: O protótipo do SLP mostrou-se um recurso alternativo no processo de inclusão social das pessoas com baixa visão com diferentes níveis de resíduo visual. Também pode proporcionar incentivo psicológico, permitir conforto, mobilidade e independência àqueles que necessitam de uma leitura mais prolongada e maior distância de trabalho.OBJECTIVE: To compare the thickness of the retinal nerve fiber layer (RNFLand the macular thickness of the amblyopic eye with those of the non-amblyopic eye in patients with unilateral amblyopia using optical coherence tomography (OCT. METHODS: OCT was performed for13 patients with unilateral amblyopia who had no neurologic disease. Nine male andfour female patients, whose ages ranged from 23 to 63 years, were enrolled in the study. The RNFL thickness average analysis program was used to evaluate mean

  2. Enabling technologies to improve area-wide integrated pest management programmes for the control of screwworms.

    Science.gov (United States)

    Robinson, A S; Vreysen, M J B; Hendrichs, J; Feldmann, U

    2009-06-01

    . Wohlfahrtia magnifica (Schiner) (Diptera: Sarcophagidae) is a screwworm of temperate regions, which, although of limited agricultural importance, has invaded several new locations in the past few years. This special issue reports on the results of a 6-year project funded by the Joint Food and Agriculture Organization of the United Nations/International Atomic Energy Agency (FAO/IAEA) Programme of Nuclear Techniques in Food and Agriculture entitled 'Enabling Technologies for the Expansion of the SIT for Old and New World Screwworm'. A major goal of the project was to better understand population genetic variation in screwworms as an aid to the identification of isolated populations. The project also addressed issues related to genetic sexing, cuticular hydrocarbons, population dynamics, genetic transformation and chromosome analysis.

  3. A importância do controle de qualidade em serviços de hemodinâmica e cardiologia intervencionista The relevance of quality control in services of hemodynamics and interventional cardiology

    Directory of Open Access Journals (Sweden)

    Eara de Souza Luz

    2007-02-01

    Full Text Available OBJETIVO: Avaliar o desempenho de um equipamento de raios X utilizado em radiologia intervencionista e a qualidade de imagem produzida, aplicando alguns testes de controle de qualidade. MATERIAIS E MÉTODOS: O equipamento de raios X testado foi da marca Philips (Integris H3000, do serviço de hemodinâmica de um hospital do Rio de Janeiro. Foram utilizados objetos de teste de Leeds para avaliar a qualidade da imagem, e um sistema Radcal 9015 para medições dosimétricas. RESULTADOS: Nos modos high e normal, os valores medidos das taxas de kerma no ar foram diferentes dos esperados. Em alguns casos, os valores das taxas medidas não foram afetados pelo uso de diferentes modos de magnificação. A avaliação da qualidade da imagem apresentou resultados diferentes dos valores recomendados pelas normas. Isto pode levar à obtenção de imagens de menor qualidade e ao aumento da exposição à radiação de pacientes e profissionais. CONCLUSÃO: Os resultados mostraram a importância da aplicação periódica de testes de controle de qualidade, que permitem monitorar o desempenho do equipamento e estimar a exposição dos pacientes e trabalhadores. Os resultados obtidos sugerem a necessidade de uma revisão no sistema de aquisição de imagens do equipamento.OBJECTIVE: To evaluate the performance and quality of images of a x-ray equipment utilized in interventional radiology, by means of some tests of quality control. MATERIALS AND METHODS: Measurements have been performed on a Philips Integris H3000 x-ray equipment dedicated to interventional procedures in the hemodynamics laboratory of a hospital in Rio de Janeiro, RJ, Brazil. Leeds test objects have been used to evaluate the image quality. Dosimetric measurements have been developed with a Radcal 9015 dosimetric system. RESULTS: In high and normal modes, the air kerma rates have been different from the expected results. In some cases, values have not been affected by the use of different

  4. Racionalidad del terror

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    Sauquillo, Julián

    2012-06-01

    ío de esa potencia difusa que conocemos como el Occidente desarrollado. Al Qaeda no duda en presentar su guerra con Occidente como una «guerra sin cuartel» hasta eliminar a los cristianos infieles y someter al mundo al Islam. Mientras tanto, en similar sentido conflictual, la campaña teórica de Samuel Huntington por todo el planeta, responde con un paradigma postguerra fría capaz de inflamar el conflicto internacional en un sentido no menos beligerante con anti-Occidente que el empleado por los imanes radicales. Como ha señalado Amartya Sen, al priorizar de esta forma la identidad religiosa, la respuesta de Occidente al terrorismo internacional como «terrorismo islámico» es muy torpe pues se magnifica la importancia de las autoridades religiosas en detrimento de los cauces gubernativos en la resolución de los problemas.

  5. Methane and Dissolved Organic Carbon Sustain an Ecosystem within a Density Stratified Coastal Aquifer of the Yucatan Peninsula, Mexico. Evidence for a Subterranean Microbial Loop?

    Science.gov (United States)

    Brankovits, David; Pohlman, John W.; Niemann, Helge; Leigh, Mary Beth; Casso, Michael; Alvarez Noguera, Fernando; Lehmann, Moritz F.; Iliffe, Thomas M.

    2016-04-01

    In coastal karst terrains, anchialine caves that meander in density stratified aquifers provide an exceptional opportunity for scientists to study in situ biogeochemical processes within the groundwater. The Caribbean coast of Mexico's Yucatan Peninsula contains over 1000 km of mapped cave passages, the densest known accumulation of anchialine caves in the world. A decades-old study based on the simple observation of 13C-depleted biomass in the cave-adapted fauna suggested biogeochemical processes related to methane-linked carbon cycling and/or other chemoautotrophic pathways as a source of energy and carbon. In this study, we utilized cave diving and a novel sampling device (the Octopipi) to obtain cm-scale water column profiles of methane, DOC and DIC concentrations and stable carbon isotope ratios to identify the energy sources and microbial processes that sustain life in these subterranean estuaries. High concentrations (up to 9522 nM) low-δ13C (as low as -67.5 permil) methane near the ceiling of the cave (in the fresh water section of the stratified water column) and evidence for methane oxidation in the brackish water portion of the water column suggest methane availability and consumption. Profiles obtained by the Octopipi demonstrate that virtually all of the methane (˜99%) is oxidized at the interface of anoxic freshwater and hypoxic brackish water masses. The high-methane water mass near the ceiling also contained elevated concentrations of DOC (851 μM) that displayed comparatively high δ13C (-27.8 to -28.2 permil), suggesting terrestrial organic matter input from the overlying soils. Low-methane brackish and saline water was characterized by lower DOC concentration (15 to 97 μM), yet with similar δ13C (-25.9 to -27.2 permil), suggesting significant terrestrial organic matter consumption or removal with increasing depth, from fresh to saline water, within the water column. The presence of 13C-depleted fatty acids (e.g., C16:1ω7c with δ13C

  6. Identification of proteins involved in the functioning of Riftia pachyptila symbiosis by Subtractive Suppression Hybridization

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    Lallier François H

    2007-09-01

    Full Text Available Abstract Background Since its discovery around deep sea hydrothermal vents of the Galapagos Rift about 30 years ago, the chemoautotrophic symbiosis between the vestimentiferan tubeworm Riftia pachyptila and its symbiotic sulfide-oxidizing γ-proteobacteria has been extensively studied. However, studies on the tubeworm host were essentially targeted, biochemical approaches. We decided to use a global molecular approach to identify new proteins involved in metabolite exchanges and assimilation by the host. We used a Subtractive Suppression Hybridization approach (SSH in an unusual way, by comparing pairs of tissues from a single individual. We chose to identify the sequences preferentially expressed in the branchial plume tissue (the only organ in contact with the sea water and in the trophosome (the organ housing the symbiotic bacteria using the body wall as a reference tissue because it is supposedly not involved in metabolite exchanges in this species. Results We produced four cDNA libraries: i body wall-subtracted branchial plume library (BR-BW, ii and its reverse library, branchial plume-subtracted body wall library (BW-BR, iii body wall-subtracted trophosome library (TR-BW, iv and its reverse library, trophosome-subtracted body wall library (BW-TR. For each library, we sequenced about 200 clones resulting in 45 different sequences on average in each library (58 and 59 cDNAs for BR-BW and TR-BW libraries respectively. Overall, half of the contigs matched records found in the databases with good E-values. After quantitative PCR analysis, it resulted that 16S, Major Vault Protein, carbonic anhydrase (RpCAbr, cathepsin and chitinase precursor transcripts were highly represented in the branchial plume tissue compared to the trophosome and the body wall tissues, whereas carbonic anhydrase (RpCAtr, myohemerythrin, a putative T-Cell receptor and one non identified transcript were highly specific of the trophosome tissue. Conclusion Quantitative PCR

  7. Metagenomic Assembly of the Dominant Zetaproteobacteria in an Iron-oxidizing Hydrothermal Microbial Mat

    Science.gov (United States)

    Moyer, C. L.; Fullerton, H.

    2013-12-01

    TCA cycle. The presence of Molybdopterin oxidoreductase, ferric uptake regulation protein, cytochromes, thioredoxin, RuBisCo and other TCA related genes support our hypothesis of chemoautotrophic primary production with the notion that Zetaproteobacteria act as ecosystem engineers driving microbial mat formation and maintenance of their habitat.

  8. Arsenic, Anaerobes, and Astrobiology

    Science.gov (United States)

    Stolz, J. F.; Oremland, R. S.; Switzer Blum, J.; Hoeft, S. E.; Baesman, S. M.; Bennett, S.; Miller, L. G.; Kulp, T. R.; Saltikov, C.

    2013-12-01

    Arsenic is an element best known for its highly poisonous nature, so it is not something one would associate with being a well-spring for life. Yet discoveries made over the past two decades have delineated that not only are some microbes resistant to arsenic, but that this element's primary redox states can be exploited to conserve energy and support prokaryotic growth ('arsenotrophy') in the absence of oxygen. Hence, arsenite [As(III)] can serve as an electron donor for chemo- or photo-autotrophy while arsenate [As(V)] will serve as an electron acceptor for chemo-heterotrophs and chemo-autotrophs. The phylogenetic diversity of these microbes is broad, encompassing many individual species from diverse taxonomic groups in the Domain Bacteria, with fewer representatives in the Domain Archaea. Speculation with regard to the evolutionary origins of the key functional genes in anaerobic arsenic transformations (arrA and arxA) and aerobic oxidation (aioB) has led to a disputation as to which gene and function is the most ancient and whether arsenic metabolism extended back into the Archaean. Regardless of its origin, robust arsenic metabolism has been documented in extreme environments that are rich in their arsenic content, such as hot springs and especially hypersaline soda lakes associated with volcanic regions. Searles Lake, CA is an extreme, salt-saturated end member where vigorous arsenic metabolism occurs, but there is no detectable sulfate-reduction or methanogenesis. The latter processes are too weak bio-energetically to survive as compared with arsenotrophy, and are also highly sensitive to the abundance of borate ions present in these locales. These observations have implications with respect to the search for microbial life elsewhere in the Solar System where volcanic-like processes have been operative. Hence, because of the likelihood of encountering dense brines in the regolith of Mars (formed by evapo-concentration) or beneath the ice layers of Europa

  9. The Precambrian Biogeochemical Carbon Isotopic Record: Contributions of Thermal Versus Biological Processes

    Science.gov (United States)

    DesMarais, David J.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Superplumes offer a new approach for understanding global C cycles. Isotopes help to discern the impacts of geological, environmental and biological processes ujpun the evolution of these cycles. For example, C-13/C-12 values of coeval sedimentary organics and carbonates give global estimates of the fraction of C buried as organics (Forg), which today lies near 0.2. Before Oxygenic photosynthesis arose, our biosphere obtained reducing power for biosynthesis solely from thermal volatiles and rock alteration. Thus Forg was dominated by the mantle redox state, which has remained remarkably constant for greater than Gy. Recent data confirm that the long-term change in Forg had been small, indicating that the mantle redox buffer remains important even today. Oxygenic photosynthesis enabled life to obtain additional reducing power by splitting the water molecule. Accordingly, biological organic production rose above the level constrained by the mantle-derived flux of reduced species. For example, today, chemoautotrophs harvesting energy from hydrothermal emanations can synthesize at most between 0.2 x 10(exp 12) and 2x 10(exp 12) mol C yr-1 of organic C globally. In contrast, global photosynthetic productivity is estimated at 9000 x 10(exp 12) mol C yr-1. Occasionally photosynthetic productivity did contribute to dramatically -elevated Forg values (to 0.4 or more) as evidenced by very high carbonate C-13/C-12. The interplay between biological, tectonic and other environmental factors is illustrated by the mid-Archean to mid-Proterozoic isotopic record. The relatively constant C-13/C-12 values of Archean carbonates support the view that photosynthetically-driven Forg increases were not yet possible. In contrast, major excursions in C-13/C-12, and thus also in Forg, during the early Proterozoic confirmed the global importance of oxygenic photosynthesis by that time. Remarkably, the superplume event at 1.9 Ga did not trigger another major Forg increase, despite the

  10. [Microbial diversity of deep-sea extremophiles--Piezophiles, Hyperthermophiles, and subsurface microorganisms].

    Science.gov (United States)

    Kato, C; Takai, K

    2000-12-01

    the deep-sea hydrothermal vents are the windows to a deep subsurface biosphere. A vast array of chemoautotrophic deep-sea animal communities have been found to exist in cold seep environments, and most of these animals are common with those found in hydrothermal vent environments. Thus, it is possible to consider that the cold seeps are also one of slit windows to a deep subsurface biosphere. We conclude that the deep-sea extremophiles are very closely related into the unseen majority in subsurface biosphere, and the subsurface biosphere probably concerns to consider the "exobiology".

  11. Sediment chemoautotrophy in the coastal ocean

    Science.gov (United States)

    Vasquez-Cardenas, Diana; Meysman, Filip J. R.; van Breugel, Peter; Boschker, Henricus T. S.

    2016-04-01

    A key process in the biogeochemistry of coastal sediments is the reoxidation of reduced intermediates formed during anaerobic mineralization which in part is performed by chemoautotrophic micro-organisms. These microbes fix inorganic carbon using the energy derived from reoxidation reactions and in doing so can fix up to 32% of the CO2 released by mineralization. However the importance and distribution of chemoautotrophy has not been systematically investigated in these environments. To address these issues we surveyed nine coastal sediments by means of bacterial biomarker analysis (phospholipid derived fatty acids) combined with stable isotope probing (13C-bicarbonate) which resulted in an almost doubling of the number of observations on coastal sedimentary chemoautotrophy. Firstly, sediment chemoautotrophy rates from this study and rates compiled from literature (0.07 to 36 mmol C m-2 d-1) showed a power-law relation with benthic oxygen uptake (3.4 to 192 mmol O2 m-2 d-1). Benthic oxygen uptake was used as a proxy for carbon mineralization to calculate the ratio of the CO2 fixed by chemoautotrophy over the total CO2 released through mineralization. This CO2 efficiency was 3% in continental shelf, 9% in nearshore and 21% in salt marsh sediments. These results suggest that chemoautotrophy plays an important role in C-cycling in reactive intertidal sediments such as salt marshes rather than in the organic-poor, permeable continental shelf sediments. Globally in the coastal ocean our empirical results show that chemoautotrophy contributes ˜0.05 Pg C y-1 which is four times less than previous estimates. Secondly, five coastal sediment regimes were linked to the depth-distribution of chemoautotrophy: 1) permeable sediments dominated by advective porewater transport, 2) bioturbated sediments, and cohesive sediments dominated by diffusive porewater transport characterized by either 3) canonical sulfur oxidation, 4) nitrate-storing Beggiatoa, or 5) electrogenic sulfur

  12. Energetic and hydrogen limitations of thermophilic and hyperthermophilic methanogens

    Science.gov (United States)

    Stewart, L. C.; Holden, J. F.

    2013-12-01

    Deep-sea hydrothermal vents are a unique ecosystem, based ultimately not on photosynthesis but chemosynthetic primary production. This makes them an excellent analog environment for the early Earth, and for potential extraterrestrial habitable environments, such as those on Mars and Europa. The habitability of given vent systems for chemoautotrophic prokaryotes can be modeled energetically by estimating the available Gibbs energy for specific modes of chemoautotrophy, using geochemical data and mixing models for hydrothermal fluids and seawater (McCollom and Shock, 1997). However, modeling to date has largely not taken into account variation in organisms' energy demands in these environments. Controls on maintenance energies are widely assumed to be temperature-dependent, rising with increasing temperature optima (Tijhuis et al., 1993), and species-independent. The impacts of other environmental stressors and particular energy-gathering strategies on maintenance energies have not been investigated. We have undertaken culture-based studies of growth and maintenance energies in thermophilic and hyperthermophilic methanogenic (hydrogenotrophic) archaea from deep-sea hydrothermal vents to investigate potential controls on energy demands in hydrothermal vent microbes, and to quantify their growth and maintenance energies for future bioenergetic modeling. We have investigated trends in their growth energies over their full temperature range and a range of nitrogen concentrations, and in their maintenance energies at different hydrogen concentrations. Growth energies in these organisms appear to rise with temperature, but do not vary between hyperthermophilic and thermophilic methanogens. Nitrogen availability at tested levels (40μM - 9.4 mM) does not appear to affect growth energies in all but one tested organism. In continuous chemostat culture, specific methane production varied with hydrogen availability but was similar between a thermophilic and a hyperthermophilic

  13. Evidence for a Methane-Fueled Ecosystem within Anchialine Caves of the Yucatan Peninsula, Mexico

    Science.gov (United States)

    Brankovits, D.; Pohlman, J.; Niemann, H.; Leigh, M. B.; Lehmann, M. F.; Iliffe, T. M.

    2014-12-01

    Anchialine caves within coastal karst terrains of the tropics contain distinct mixtures of fresh and marine water separated by a sharp pycnocline. The Caribbean coast of Mexico's Yucatan Peninsula contains over 1000 km of mapped cave passages, the densest known accumulation of anchialine caves in the world. Deep within the caves and beyond where vegetative detritus from the entrance pool (or cenote) is present, a surprising diversity of higher-order animals (mostly crustaceans) is found. How these ecosystems thrive in an environment where no obvious sources of food are visible is enigmatic. A decades-old study based on the simple observation of 13C-depleted biomass in the stygobitic (cave-adapted) fauna suggested biogeochemical processes related to methane-linked carbon cycling and/or other chemoautotrophic pathways as a source of energy and carbon, but was unable to identify the exact source of this material. In this study, we investigate the biogeochemistry of four anchialine caves along an 8 km transect running perpendicular to the coastline. We measured the distribution, concentration and isotopic composition of biotic and abiotic components of the ecosystem to identify the energetic sources and microbial processes that sustain life in this subsurface aquifer. High concentrations of methane (5 µM) and evidence for methane oxidation in the fresh water portion of the water column suggest methane availability and consumption. Furthermore, the presence of 13C-depleted fatty acids (e.g., C16:1ω7c with δ13C-values as low as -54.1‰) and deuterium-depleted δD values (e.g., as low as δD = -225‰) from tissues of an atyid shrimp provide evidence that methanotrophic bacteria were a substantial fraction of its diet. Molecular microbial community analyses of shrimp guts and the water column are underway to identify the methanotrophs. These findings have the potential to reframe the carbon cycle and ecosystem dynamics for an isolated, yet widespread habitat within

  14. Methane fates in the benthos and water column at cold seep sites along the continental margin of Central and North America

    Science.gov (United States)

    Hansman, Roberta L.; Thurber, Andrew R.; Levin, Lisa A.; Aluwihare, Lihini I.

    2017-02-01

    The potential influence of methane seeps on carbon cycling is a key question for global assessments, but the study of carbon cycling in surface sediments and the water column of cold seep environments is complicated by the high temporal and spatial variability of fluid and gas fluxes at these sites. In this study we directly examined carbon sources supporting benthic and planktonic food webs at venting methane seeps using isotopic and molecular approaches that integrate this variability. At four seep environments located along North and Central America, microorganisms from two size fractions were collected over several days from 2800 to 9050 l of seawater to provide a time-integrated measure of key microbial groups and the carbon sources supporting the overall planktonic microbial community. In addition to water column measurements, the extent of seafloor methane release was estimated at two of the sites by examining the stable carbon isotopic signature (δ13C) of benthic metazoan infauna. This signature reveals carbon sources fueling the base of the food chain and thus provides a metric that represents a time-integrated view of the dominant microbial processes within the sediment. The stable carbon isotopic composition of microbial DNA (δ13C-DNA), which had values between -17.0 and -19.5‰, indicated that bulk planktonic microbial production was not ultimately linked to methane or other 13C-depleted seep-derived carbon sources. Instead these data support the importance of organic carbon derived from either photo- or chemoautotrophic CO2 fixation to the planktonic food web. Results of qPCR of microbial DNA sequences coding for a subunit of the particulate methane monooxygenase gene (pmoA) showed that only a small percentage of the planktonic microbial community were potential methane oxidizers possessing pmoA (<5% of 16S rRNA gene copies). There was an overall decrease of 13C-depleted carbon fueling the benthic metazoan community from 3 to 5 cm below the seafloor

  15. Geochemical Evidence for Recent Hydrothermal Alteration of Marine Sediments in Mid-Okinawa Trough, Southwest Japan

    Science.gov (United States)

    Tanaka, A.; Abe, G.; Yamaguchi, K. E.

    2014-12-01

    Recent studies have shown that submarine hydrothermal system supports diverse microbial life. Bio-essential metals supporting such microbial communities were released from basalts by high-temperature water-rock interaction in deeper part of the oceanic crust and carried by submarine fluid flow. Its total quantity in global hydrothermal settings has been estimated to be on the order of ~1019 g/yr, which is surprisingly on the same order of the total river flows (Urabe et al., 2011). Therefore, it is important to explore how submarine river system works, i.e., to understand mechanism and extent of elemental transport, which should lead to understanding of the roles of hydrothermal circulation in oceanic crust in controlling elemental budget in the global ocean and geochemical conditions to support deep hot biosphere.  We performed REE analysis of marine sediments influenced by submarine hydrothermal activity in Mid-Okinawa Trough. The sediment samples used in this study are from IODP site at Iheya North region and JADE site at Izena region. The samples show alternation between volcanic and clastic sediments. Hydrothermal fluids of this area contain elevated concentrations of volatile components such as H2, CO2, CH4, NH4+, and H2S, supporting diverse chemoautotrophic microbial community (Nakagawa et al., 2005). The purpose of this study is to examine the effect of hydrothermal activity on the REE signature of the sediments. Chondrite-normalized REE patterns of the samples show relative enrichment of light over heavy REEs, weak positive Ce anomalies, and variable degrees of negative Eu anomalies. The REE patterns suggest the sediments source was mainly basalt, suggesting insignificant input of continental materials. Negative Eu anomalies found in the IODP site become more pronounced with increasing depth, suggesting progressive increase of hydrothermal alteration where Eu was reductively dissolved into fluids by decomposition of feldspars. Contrary, at the JADE site

  16. Biogeography, biodiversity and fluid dependence of deep-sea cold-seep communities at active and passive margins

    Science.gov (United States)

    Sibuet, Myriam; Olu, Karine

    1998-01-01

    To date, several cold-seep areas which fuel chemosynthesis-based benthic communities have been explored, mainly by deployment of manned submersibles. They are located in the Atlantic and in the Eastern and Western Pacific oceans and in the Mediterranean Sea, in depths ranging between 400 and 6000 m in different geological contexts in passive and active margins. Our study is based on a review of the existent literature on 24 deep cold seeps. The geographic distribution of seeps, the variations of origin and composition of fluids, and rates of fluid flow are presented as they are important factors which explain the spatial heterogeneity and the biomass of biological communities. Methane-rich fluid of thermogenic and/or biogenic origin is the principal source of energy for high-productive communities; however, production of sulphide by sulphate reduction in the sediment also has a major role. The dominant seep species are large bivalves belonging to the families Vesicomyidae or Mytilidae. Other symbiont-containing species occur belonging to Solemyidae, Thyasiridae, Lucinidae bivalves, Pogonophora worms, Cladorhizidae and Hymedesmiidae sponges. Most of the symbiont-containing cold-seep species are new to science. Different symbiont-containing species rely on sulphide or methane oxidation, or both, via chemoautotrophic endosymbiotic bacteria. A total of 211 species, from which 64 are symbiont-containing species, have been inventoried. Patterns in biodiversity and biogeography are proposed. A large majority of the species are endemic to a seep area and the symbiont-containing species are mainly endemic to the cold-seep ecosystem. A comparison of species found in other deep chemosynthesis-based ecosystems, hydrothermal vents, whale carcass and shipwreck reduced habitats, reveals from the existing data, that only 13 species, of which five are symbiont-containing species occur, at both seeps and hydrothermal vents. The species richness of cold-seep communities decreases

  17. Metagenomics, single cell genomics, and steady-state free energy flux provide insight into the biogeochemical cycling of deep, meteoric water

    Science.gov (United States)

    Magnabosco, C.; Lau, C. M.; Ryan, K.; Kieft, T. L.; Snyder, L.; Sherwood Lollar, B.; Lacrampe Couloume, G.; Hendrickson, S.; Pullin, M. J.; Slater, G. F.; Simkus, D.; Borgonie, G.; van Heerden, E.; Kuloyo, O.; Maleke, M.; Tlalajoe, T.; Vermeulen, J.; Vermeulen, F.; Munro, A.; Pienaar, M.; Stepanauskas, R.; Grim, S. L.; Onstott, T. C.

    2013-12-01

    Prior to the onset of high-throughput sequencing, the study of biogeochemical cycling in the terrestrial deep subsurface was limited to geochemical, thermodynamic, culture dependent microbial and low-throughput molecular analyses. Here, we present an integration of these traditional methods with high-throughput metagenomic and single cell analysis of 3.1 km deep water collected from a borehole (TT107) located in AngloGold Ashanti's TauTona Au Mine of South Africa and intersecting a fracture within a Witwatersrand Supergroup quartzite. The low salinity fracture water encountered at this depth is meteoric in origin and has a subsurface residence time on the order of a few thousand years. Aqueous geochemistry and estimated steady-state free energy flux values suggest that redox reactions are driven by the oxidation of abundant, energy-rich substrates including H2, CO, CH4, formate, and propanoate. The majority of the metagenome's sequences related to the phyla Firmicutes and Proteobacteria, which contain several bacterial species that are likely to exhibit chemoautotrophic metabolism. Sequence data confirms that many of these bacteria have the ability reduce of sulfur and nitrogen species via dissimilatory pathways. Thermincola were the most abundant firmicutes at this location and were sequenced at the single cell level. Notably, Thermincola sp. are capable of reducing metals and may utilize energy rich manganese reduction pathways at TT107. The CH4 at this site is of abiological origin (δ13C-C1-3 = -43.5 to -44.3 VPDB; δ2H-C1-3 = -345 to -200 VSMOW) despite the metagenome containing several sequences that are closely related to methanogens in the archaeal phyla Euryarchaeota. Alternatively, these archaea may belong to a group of euryarchaetoa commonly referred to as anaerobic mehanotrophic archaea (ANME) - suggesting that anaerobic oxidation (AOM) of abiogenic CH4 coupled to the reduction of sulfate species may be occurring at this site. Sequences for pmoA and s

  18. The Microbiome and Occurrence of Methanotrophy in Carnivorous Sponges

    Science.gov (United States)

    Hestetun, Jon T.; Dahle, Håkon; Jørgensen, Steffen L.; Olsen, Bernt R.; Rapp, Hans T.

    2016-01-01

    As shown by recent studies, filter-feeding sponges are known to host a wide variety of microorganisms. However, the microbial community of the non-filtering carnivorous sponges (Porifera, Cladorhizidae) has been the subject of less scrutiny. Here, we present the results from a comparative study of the methanotrophic carnivorous sponge Cladorhiza methanophila from a mud volcano-rich area at the Barbados Accretionary Prism, and five carnivorous species from the Jan Mayen Vent Field (JMVF) at the Arctic Mid-Ocean Ridge. Results from 16S rRNA microbiome data indicate the presence of a diverse assemblage of associated microorganisms in carnivorous sponges mainly from the Gamma- and Alphaproteobacteria, Flavobacteriaceae, and Thaumarchaeota. While the abundance of particular groups varied throughout the dataset, we found interesting similarities to previous microbiome results from non-carnivorous deep sea sponges, suggesting that the carnivorous sponges share characteristics of a previously hypothesized putative deep-sea sponge microbial community. Chemolithoautotrophic symbiosis was confirmed for C. methanophila through a microbial community with a high abundance of Methylococcales and very light isotopic δ13C and δ15N ratios (-60 to -66‰/3.5 to 5.2‰) compared to the other cladorhizid species (-22 to -24‰/8.5 to 10.5‰). We provide evidence for the presence of putative sulfur-oxidizing Gammaproteobacteria in the arctic cladorhizids; however, δ13C and δ15N signatures did not provide evidence for significant chemoautotrophic symbiosis in this case, and the slightly higher abundance of cladorhizids at the JMVF site compared to the nearby deep sea likely stem from an increased abundance of prey rather than a more direct vent association. The phylogenetic position of C. methanophila in relation to other carnivorous sponges was established using a three-gene phylogenetic analysis, and it was found to be closely related to other non-methanotrophic Cladorhiza species

  19. Engineering and Coordination of Regulatory Networks and Intracellular Complexes to Maximize Hydrogen Production by Phototrophic Microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    James C. Liao

    2012-05-22

    This project is a collaboration with F. R. Tabita of Ohio State. Our major goal is to understand the factors and regulatory mechanisms that influence hydrogen production. The organisms to be utilized in this study, phototrophic microorganisms, in particular nonsulfur purple (NSP) bacteria, catalyze many significant processes including the assimilation of carbon dioxide into organic carbon, nitrogen fixation, sulfur oxidation, aromatic acid degradation, and hydrogen oxidation/evolution. Our part of the project was to develop a modeling technique to investigate the metabolic network in connection to hydrogen production and regulation. Organisms must balance the pathways that generate and consume reducing power in order to maintain redox homeostasis to achieve growth. Maintaining this homeostasis in the nonsulfur purple photosynthetic bacteria is a complex feat with many avenues that can lead to balance, as these organisms possess versatile metabolic capabilities including anoxygenic photosynthesis, aerobic or anaerobic respiration, and fermentation. Growth is achieved by using H{sub 2} as an electron donor and CO{sub 2} as a carbon source during photoautotrophic and chemoautotrophic growth, where CO{sub 2} is fixed via the Calvin-Benson-Bassham (CBB) cycle. Photoheterotrophic growth can also occur when alternative organic carbon compounds are utilized as both the carbon source and electron donor. Regardless of the growth mode, excess reducing equivalents generated as a result of oxidative processes, must be transferred to terminal electron acceptors, thus insuring that redox homeostasis is maintained in the cell. Possible terminal acceptors include O{sub 2}, CO{sub 2}, organic carbon, or various oxyanions. Cells possess regulatory mechanisms to balance the activity of the pathways which supply energy, such as photosynthesis, and those that consume energy, such as CO{sub 2} assimilation or N{sub 2} fixation. The major route for CO{sub 2} assimilation is the CBB

  20. Biomineralization and biosignatures of coralloid-type speleothems from lava tubes of Galapagos Islands: evidences on the fossil record of prokaryotes

    Science.gov (United States)

    Miller, Ana Z.; Garcia-Sanchez, Angela M.; Pereira, Manuel F. C.; Gazquez, Fernando; Calaforra, José M.; Forti, Paolo; Toulkeridis, Theofilos; Martínez-Frías, Jesús; Saiz-Jimenez, Cesareo

    2016-04-01

    , whereas the final stage mainly consists of low crystalline calcite. FESEM-EDS analysis revealed mineralized bacterial filaments rich in Si on the coralloid samples, as well as minerals precipitation associated with extracellular polymeric substances (EPS), which serve as nuclei for preferential precipitation on the extracellular sheaths. This suggests that biological activity played a major role in the development of these speleothems. In addition, imprints of filamentous cells and microboring readily preserved on siliceous minerals were observed on the coralloid speleothems. These features are recognized as biosignatures valuable for astrobiology and may represent modern analogs of the fossil record of prokaryotes. DNA-based analyses showed that bacteria belonging to Actinobacteria (31%) Gemmatimonadetes (25%) and Proteobacteria (24%) phyla dominated in this cave ecosystem, followed by Acidobacteria, Firmicutes and Nitrospirae. Most of the identified phylotypes were affiliated to chemoautotrophs, including thermophilic bacteria such as Ferrithrix thermotolerans, and other mineral utilizing microorganisms like Aciditerrimonas ferrireducens, Desulfuromonas sp. and Desulfovibrio sp., indicating that Galapagos lava tubes host highly specialized subsurface biosphere dominated by microorganisms able to interact with minerals and promote biomineralization. Acknowledgments: This work has been supported by the project PC-65-14 from the Ministry of Environment of Ecuador. AZM acknowledges the support from the Marie Curie Fellowship of the 7th EC Framework Programme (PIEF-GA-2012-328689-DECAVE). The authors acknowledge the Spanish Ministry of Economy and Competitiveness (project CGL2013-41674-P) and FEDER funds for financial support.

  1. A lander mission to probe subglacial water on Saturn's moon Enceladus for life

    Science.gov (United States)

    Konstantinidis, Konstantinos; Flores Martinez, Claudio L.; Dachwald, Bernd; Ohndorf, Andreas; Dykta, Paul; Bowitz, Pascal; Rudolph, Martin; Digel, Ilya; Kowalski, Julia; Voigt, Konstantin; Förstner, Roger

    2015-01-01

    The plumes discovered by the Cassini mission emanating from the south pole of Saturn's moon Enceladus and the unique chemistry found in them have fueled speculations that Enceladus may harbor life. The presumed aquiferous fractures from which the plumes emanate would make a prime target in the search for extraterrestrial life and would be more easily accessible than the moon's subglacial ocean. A lander mission that is equipped with a subsurface maneuverable ice melting probe will be most suitable to assess the existence of life on Enceladus. A lander would have to land at a safe distance away from a plume source and melt its way to the inner wall of the fracture to analyze the plume subsurface liquids before potential biosignatures are degraded or destroyed by exposure to the vacuum of space. A possible approach for the in situ detection of biosignatures in such samples can be based on the hypothesis of universal evolutionary convergence, meaning that the independent and repeated emergence of life and certain adaptive traits is wide-spread throughout the cosmos. We thus present a hypothetical evolutionary trajectory leading towards the emergence of methanogenic chemoautotrophic microorganisms as the baseline for putative biological complexity on Enceladus. To detect their presence, several instruments are proposed that may be taken aboard a future subglacial melting probe. The "Enceladus Explorer" (EnEx) project funded by the German Space Administration (DLR), aims to develop a terrestrial navigation system for a subglacial research probe and eventually test it under realistic conditions in Antarctica using the EnEx-IceMole, a novel maneuverable subsurface ice melting probe for clean sampling and in situ analysis of ice and subglacial liquids. As part of the EnEx project, an initial concept study is foreseen for a lander mission to Enceladus to deploy the IceMole near one of the active water plumes on the moon's South-Polar Terrain, where it will search for

  2. Massive Expansion of Marine Archaea During The Early Albian Oceanic Anoxic Event 1B

    Science.gov (United States)

    Kuypers, M. M.; Kuypers, M. M.; Blokker, P.; Erbacher, J.; Kinkel, H.; Pancost, R. D.; Pancost, R. D.; Schouten, S.; Sinninghe Damsté, J. S.

    2001-12-01

    environments. We can only speculate about the causes of this unprecedented massive expansion of marine planktonic archaea during the mid-Cretaceous OAE1b. Prolonged periods of enhanced hydrothermal activity would have significantly altered the ocean chemistry during the mid-Cretaceous, providing the necessary reduced compounds like ammonium to sustain a large community of chemoautotrophic archaea. In addition pronounced water stratification and anoxic conditions such as existed during the OAE1b could have provided a competitive advantage for archaea over phytoplankton utilising ammonium, allowing a diverse community of nitrifying non-thermophilic archaea to evolve. In any case our data show that there seems to be no unifying mechanism for black shale deposition during the mid-Cretaceous OAEs. Although there are apparent similarities (distinct lamination, 13C-enrichment of OC) between the black shales of OAE1b and other OAEs, our detailed molecular work shows that the origin of the OM (archaeal versus phytoplanktonic) and causes for 13C-enrichment of OC are completely different.

  3. RGC -32在大鼠主动脉损伤后的表达%Expression of RGC - 32 in Rat Injured Aorta

    Institute of Scientific and Technical Information of China (English)

    黎思毅; 彭红娟

    2016-01-01

    Objective To investigate the Expression of RGC - 32 in the aorta of rats after balloon injury ,Ultimately,to create the theo-retical foundation for RGC - 32 as a new target treating restenosis after angioplasty. Method The sixteen SD male rat were randomly separa-ted into two groups:control group(n = 8),balloon - injured group(n = 8). The model of rat aorta injury was established with a 2F Fogarty catheter. The vascular tissues were harvested at 28 days after the operation respectively. ①Histomorphology:After HE staining and observa-tion using optical microscopy,the intima area of all was measured by computer graph analysis system;②Immunohistochemistry(SP method) was used to determine the differential expressional level of RGC - 32 with time. The slides were observed by microscopy at high magnifica-tion at each time period and proportion of positive cells were calculated;③The expression level of RGC - 32 mRNA were detected with the method of Real Time RT - PCR. Results Intima area - media area ratio(IA/ MA)was found increasing in alloon - injured group(vs con-trol,P ﹤ 0. 05). The amount of RGC - 32 positive cells and the expression of RGC - 32 mRNA increased than control group,the difference was statistically significant(P ﹤ 0. 05). Conclusion The expression of RGC - 32 increased in Rat Injured Aorta,RGC - 32 may emerge as a promising target of therapy for restenosis.%目的:对 RGC -32在大鼠主动脉损伤后的表达情况作初步研究,为血管术后再狭窄防治提供新思路。方法:选用雄性 SD 大鼠16只,大鼠随机分为两组。手术组:8只大鼠行球囊损伤大鼠主动脉术,术后28 d 处死。对照组:8只大鼠,除不插入2F - Fogarty 球囊导管进行损伤外,其他处理措施均与手术组相同,术后28 d 处死。处死后收集大鼠主动脉术标本。分别进行下列检测:①血管形态学检测:切片 HE 染色;②SP 染色免疫组织化学检测 RGC -32表达,高倍光学显

  4. Diabetes mellitus en adultos mexicanos: resultados de la Encuesta Nacional de Salud 2000 Diabetes mellitus in Mexican adults: results from the 2000 National Health Survey

    Directory of Open Access Journals (Sweden)

    Gustavo Olaiz-Fernández

    2007-01-01

    xico. Su efecto se magnifica al afectar con mayor frecuencia a grupos de población cuyos factores sociales o económicos limitan su acceso al tratamiento. Los datos informados son útiles para la institución de programas de escrutinio y prevención. Los resultados confirman que la diabetes debe ser motivo de investigación en familiares de primer grado e individuos que tengan uno o más de los componentes del síndrome metabólico (hipertensión, dislipidemia, obesidad y microalbuminuria.OBJECTIVE: To show the prevalence of diabetes mellitus (DM and its associated factors in adults, using data derived from the 2000 National Health Survey (NHS. MATERIAL AND METHODS: The 2000 NHS was conducted between November 1999 and June 2000. An adult questionnaire was administered to 45 294 subjects 20 years of age and older. Capillary glucose levels, weight, height and blood pressure were obtained. Individual weighted factors were considered in the statistical analysis, as was the survey's complex sampling design to obtain variances using SUDAAN 7.5.6. RESULTS: The national prevalence of DM in adults ages 20 years and older was 7.5% (95% CI: 7.1-7.9. The prevalence was 7.8% in women and 7.2% in men. It was higher according to age: 2.3% in adults 40 years or younger and 21.2% in those older than 60 years of age. In the urban population, prevalence was 8.1% and in the rural population it was 6.5%. The disease was more frequent in the northern region of the country (8.4% and in the Mexico City metropolitan area (8.1%. DM was more frequent in the population with the least amount of schooling (9.9%, the lowest income (8.1%, high blood pressure (13.7%, hypercholesterolemia (23.3% microalbuminuria (15.5% and renal disease (12.3%. Using multivariate logistic regression, stratified by gender, variables associated with DM were identified: age, little schooling, family history of DM, high blood pressure, renal disease or hypercholesterolemia in both genders. Abdominal obesity was associated

  5. Ergonomics: a study of influence on productivity Ergonomía: un estudio de su influencia en la productividad Ergonomia: um estudo sobre sua influência na produtividade

    Directory of Open Access Journals (Sweden)

    Carlos Rodrigues da Silva

    2009-12-01

    Full Text Available Companies, governments and society are showing an increasing interest in ergonomics as applied to productive activities. Therefore the Brazilian government has issued Norma Regulamentadora 17 - Ergonomia to establish parameters for adapting working conditions to the psycho-physiologic characteristics of workers. This work evaluated ergonomics, productivity and work stations at “Magnifica Confecções” in Paranaíba, where most machines are operated in a seated position with repetitive movements. Therefore ergonomic concepts aspects are decisive to improve productivity and well-being of collaborators. Ergonomics is used at the work stations in a constructive and participative problem solving process requiring understanding of the tasks, activities, problems and performance demanded. For this reason, resultant data was supported by questionnaires answered by the diverse participants that developed these activities resolving these problems.Es creciente el interés de las empresas, los gobiernos y la sociedad por el estudio de la ergonomía aplicada a las actividades productivas. En este sentido, el gobierno brasileño ha publicado la “Norma Reglamentaria 17 - Ergonomía”, que tiene por objeto establecer los parámetros para la adecuación de las condiciones de trabajo a las características psicofisiológicas de los trabajadores. Este trabajo tiene como objetivo evaluar los puestos de trabajo de la empresa “Magnífica Confecções”, en Paranaíba, MS, Brasil, en relación a su ergonomía, y determinar su influencia en la productividad. El uso constante de las máquinas, la posición sentada y la repetición de los movimientos implicados en la actividad industrial son característicos del puesto de trabajo de la organización. Por estas características, la atención a las exigencias ergonómicas es un factor decisivo para aumentar la productividad y mejorar el bienestar de las participantes. La aplicación de los conceptos de ergonom

  6. Diversity and temporal dynamics of a litchi orchard arthropod community in Guangzhou%广州荔枝园节肢动物群落多样性及时空动态

    Institute of Scientific and Technical Information of China (English)

    孟翔; 欧阳革成; 刘慧; 黄寿山; 郭明昉

    2015-01-01

    Objectives] To provide a theoretical basis for forecasting and scientific biological control of major litchi orchard pests. [Methods] The structure and dynamics of the arthropod community in a litchi orchard in Conghua, Guangzhou was investigated in the field from 2012 to 2013. [Results] 3 542 arthropod specimens, belonging to 15 orders, 113 families and 204 species, were recorded. The main taxa were Hymenoptera, Homoptera and Araneae. Herbivorous species were predominant. Different micro-environments within the orchard could have a different community composition; the index of arthropod community diversity was higher in the canopy than in the herb layer but arthropod abundance in the canopy was lower than in the herb layer. There were two obvious peaks in species abundance with the main peak occurring between April and June. Herbivorous insects significantly increased during the green fruit and ripening periods. Seasonal variation in community composition was also relatively obvious in the canopy and herb layer. The dominant pest species were Tessaratoma papillosa, Cletus punctiger, Conopomorpha sinensis, Eriophyes litchii and Thalassodes proquadraria, and the dominant natural enemies were Leucauge magnifica, Oxyopes sertatus, Chrysopa carnea, Menochilus sexmaculataand Propylea japonica. [Conclusion] Litchi orchards have high arthropod species diversity. The number and occurrence of dominant pests and their predatory natural enemies are closely related to the growth and development of litchi fruit.%【目的】调查研究荔枝园节肢动物群落多样性及时空动态,为荔枝园主要害虫的预测预报和以天敌为主的科学防治提供理论依据。【方法】2012―2013年以广州市从化区黄围村的荔枝园为样地进行节肢动物群落系统调查及多样性动态规律分析。【结果】调查共获得节肢动物标本3542号,分属于15目113科204种。其中,以膜翅目、同翅目和蜘蛛目为主要类群。在营

  7. Development of biological platform for the autotrophic production of biofuels

    Science.gov (United States)

    Khan, Nymul

    of the current status of metabolic engineering of chemolithoautotrophs is carried out in order to identify the challenges and likely routes to overcome them. This is presented in Chapter 3 of this dissertation. The initial metabolic engineering and bioreactor studies was carried out using a number of gene-constructs on R. capsulatus and R. eutropha. The gene-constructs consisted of Plac promoter followed by the triterpene synthase genes (SS or BS) and other upstream genes. A comparison of the production of triterpenes were done in the different growth modes that R. capsulatus was capable of growing---aerobic heterotrophic, anaerobic photoheterotrophic and aerobic chemoautotrophic. Autotrophic productivity could likely be improved much further by increasing the available mass-transfer of the reactor. These efforts are presented in Chapter 4 of this dissertation. (Abstract shortened by UMI.).

  8. Worldwide Eutrophication of Water Bodies: Causes, Concerns, Controls

    Science.gov (United States)

    Prepas, E. E.; Charette, T.

    2003-12-01

    ; therefore, phosphorus most often limits the growth of phytoplankton. As a result, phosphorus enrichment of freshwater often causes its eutrophication ( Schindler, 1977). In lakes, nitrogen is usually present in concentrations equal to or beyond what is required for aquatic plant growth because, unlike phosphorus, it has an atmospheric source. In marine systems, nitrogen concentrations are often limiting because bacterial nitrogen fixation, while a considerable source of nitrogen in lakes, not as important in marine waters. A wide variety of prokaryotic organisms (i.e., certain cyanobacteria, heterotrophic, and chemoautotrophic bacteria) can use nitrogen gas directly and incorporate it into organic compounds through a process called nitrogen fixation. Nitrogen fixation is an enzyme-catalyzed process that reduces nitrogen gas (N2) to ammonia (NH3). Nitrogen-fixing cyanobacteria make up less than 1% of the total biomass of phytoplankton in estuaries of the Atlantic coast of North America, whereas in lakes they often make up more than 50% of phytoplankton biomass (reviewed in Howarth, 1988). An increase in water clarity can also spur the growth of aquatic vegetation in systems where the clarity of water is poor from high concentrations of suspended particles.The biodiversity of most aquatic systems decreases with eutrophication (Figure 1). Phytoplankton species diversity is reduced in highly productive systems. Cyanobacteria are usually dominant in eutrophic systems because these organisms are better adapted to conditions of high nutrients (Smith, 1986; Trimbee and Prepas, 1987; Watson et al., 1997). In addition, fish and macro-invertebrate species diversity can decrease with eutrophication. Depletion of dissolved oxygen in deep water is associated with eutrophication and can lead to a loss or displacement of species intolerant of such conditions ( Ludsin et al., 2001). In eutrophic lakes of North America, characteristic fish types are surface-dwelling, warm water fishes such