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Sample records for alkaline hypersaline mono

  1. Organic Osmolytes in Aerobic Bacteria from Mono Lake, an Alkaline, Moderately Hypersaline Environment

    PubMed Central

    Ciulla, R. A.; Diaz, M. R.; Taylor, B. F.; Roberts, M. F.

    1997-01-01

    The identity and concentrations of intracellular organic solutes were determined by nuclear magnetic resonance spectroscopy for two strains of aerobic, gram-negative bacteria isolated from Mono Lake, Calif., an alkaline, moderately hypersaline lake. Ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid) was the major endogenous solute in both organisms. Concentrations of ectoine varied with external NaCl levels in strain ML-D but not in strain ML-G, where the level was high but invariant from 1.5 to 3.0 M NaCl. Hydroxyectoine also occurred in strain ML-D, especially at elevated NaCl concentrations (2.5 and 3.0 M), but at levels lower than those of ectoine. Exogenous organic solutes that might occur in Mono Lake were examined for their effects on the de novo synthesis of ectoine. Dimethylsulfoniopropionate (DMSP) (0.1 or 1 mM) did not significantly lower ectoine levels in either isolate, and only strain ML-G showed any capacity for DMSP accumulation. With nitrogen limitation, however, DMSP (0.1 mM) substituted for ectoine in strain ML-G and became the main organic solute. Glycine betaine (GB) was more effective than DMSP in affecting ectoine levels, principally in strain ML-D. Strain ML-D accumulated GB to 50 or 67% of its organic solute pool at 2.5 M NaCl, at an external level of 0.1 or 1 mM GB, respectively. Strain ML-D also accumulated arsenobetaine. The methylated zwitterionic compounds, probably metabolic products of phytoplankton (DMSP and GB) or brine shrimps (arsenobetaine) in Mono Lake, may function as osmolytes for indigenous bacteria when present at high concentrations or under conditions of nitrogen limitation or salt stress. PMID:16535487

  2. Thio-arsenic species in alkaline, hypersaline, meromictic Mono Lake, California

    NASA Astrophysics Data System (ADS)

    Hollibaugh, J. T.; Carini, S.; Gürleyük, H.; Jellison, R.; Joye, S. B.; Lecleir, G.; Meile, C.; Vasquez, L.; Wallschläger, D.

    2004-12-01

    Mono Lake had been meromictic for 8 years when sampled (Feb-Nov, 2002). Arsenic speciation was determined by IC-ASRS-ICP-MS of samples preserved in the field by flash-freezing in liquid nitrogen. Arsenic speciation was dominated by arsenate when oxygen was detectable, but shifted to dominance by reduced species once oxygen was no longer detectable. Thio-arsenic species were the dominant form of As found in sulfidic waters. Maxima of thio-arsenic species with stoichiometries consistent with mono-, di- and tri-thio-arsenic occurred in succession as sulfide concentration increased. A compound with a stoichiometry consistent with tri-thio-arsenic was the dominant As species (>50% of total As) in high sulfide (>2 mM) bottom water. Comparison of the data with a simple equilibrium model suggested that the distributions do not represent simple chemical equilibria driven by sulfide concentration. Lower concentrations of total As in bottom water relative to surface water suggest precipitation of As/S mineral phases in response to sulfide accumulation during prolonged anoxia.

  3. Anaerobic Halo-Alkaliphilic Baterial Community of Athalassic, Hypersaline Mono Lake in California

    NASA Technical Reports Server (NTRS)

    Pikuta, Elena V.; Hoover, Richard B.; Marsic, Damien; Ng, Joseph D.; Six, N. Frank (Technical Monitor)

    2002-01-01

    The microorganisms of soda Mono Lake and other similar athalassic hypersaline alkaline soda lakes are of significance to Astrobiology. The microorganisms of these regimes represent the best known terrestrial analogs for microbial life that might have inhabited the hypersaline alkaline lakes and evaporites confined within closed volcanic basins and impact craters during the late Noachian and early Hesperian epochs (3.6 - 4.2 Gya) of ancient Mars. We have investigated the anaerobic microbiota of soda Mono Lake in northern California. In this paper we discuss the astrobiological significance of these ecosystems and describe several interesting features of two novel new species of anaerobic halo-alkaliphilic bacteria (Spirochaeta americana, sp. nov. and Desulfonatronum paiuteum, sp. nov) that we have isolated from Mono Lake.

  4. Alkaline Hypersaline Lakes as Analogs for Ancient Microbial Habitats on Mars

    NASA Technical Reports Server (NTRS)

    McDonald, G. D.; Tsapin, A. I.; Storrie-Lombardi, M. C.; Nealson, K. H.; Brinton, K. L. F.; Sun, H.; Venkateswaren, K.; Tsapin, I.; Melack, J.; Jellison, R.

    1999-01-01

    As the climate of ancient Mars became colder and drier with time, open bodies of water would have entered a regime in which evaporation exceeded input from precipitation or runoff. This would have resulted in increases in salinity and perhaps pH. The last open water on Mars was most likely found in alkaline hypersaline lakes, and these lakes would have been the last surface aquatic habitats for life on Mars. It follows, then, that the biomarkers most likely to be found in ancient sedimentary basins on Mars are those left by organisms adapted to high salt and high pH environments. We have begun to investigate the nature of biological diversity and adaptation to these environments, and the potential for biomarker preservation in them, using Mono Lake as a terrestrial analog environment. Additional information is contained in the original extended abstract.

  5. Archaeal Communities in a Heterogeneous Hypersaline-Alkaline Soil.

    PubMed

    Navarro-Noya, Yendi E; Valenzuela-Encinas, César; Sandoval-Yuriar, Alonso; Jiménez-Bueno, Norma G; Marsch, Rodolfo; Dendooven, Luc

    2015-01-01

    In this study the archaeal communities in extreme saline-alkaline soils of the former lake Texcoco, Mexico, with electrolytic conductivities (EC) ranging from 0.7 to 157.2 dS/m and pH from 8.5 to 10.5 were explored. Archaeal communities in the 0.7 dS/m pH 8.5 soil had the lowest alpha diversity values and were dominated by a limited number of phylotypes belonging to the mesophilic Candidatus Nitrososphaera. Diversity and species richness were higher in the soils with EC between 9.0 and 157.2 dS/m. The majority of OTUs detected in the hypersaline soil were members of the Halobacteriaceae family. Novel phylogenetic branches in the Halobacteriales class were detected in the soil, and more abundantly in soil with the higher pH (10.5), indicating that unknown and uncharacterized Archaea can be found in this soil. Thirteen different genera of the Halobacteriaceae family were identified and were distributed differently between the soils. Halobiforma, Halostagnicola, Haloterrigena, and Natronomonas were found in all soil samples. Methanogenic archaea were found only in soil with pH between 10.0 and 10.3. Retrieved methanogenic archaea belonged to the Methanosarcinales and Methanomicrobiales orders. The comparison of the archaeal community structures considering phylogenetic information (UniFrac distances) clearly clustered the communities by pH. PMID:26074731

  6. Archaeal Communities in a Heterogeneous Hypersaline-Alkaline Soil

    PubMed Central

    Navarro-Noya, Yendi E.; Valenzuela-Encinas, César; Sandoval-Yuriar, Alonso; Jiménez-Bueno, Norma G.; Marsch, Rodolfo

    2015-01-01

    In this study the archaeal communities in extreme saline-alkaline soils of the former lake Texcoco, Mexico, with electrolytic conductivities (EC) ranging from 0.7 to 157.2 dS/m and pH from 8.5 to 10.5 were explored. Archaeal communities in the 0.7 dS/m pH 8.5 soil had the lowest alpha diversity values and were dominated by a limited number of phylotypes belonging to the mesophilic Candidatus Nitrososphaera. Diversity and species richness were higher in the soils with EC between 9.0 and 157.2 dS/m. The majority of OTUs detected in the hypersaline soil were members of the Halobacteriaceae family. Novel phylogenetic branches in the Halobacteriales class were detected in the soil, and more abundantly in soil with the higher pH (10.5), indicating that unknown and uncharacterized Archaea can be found in this soil. Thirteen different genera of the Halobacteriaceae family were identified and were distributed differently between the soils. Halobiforma, Halostagnicola, Haloterrigena, and Natronomonas were found in all soil samples. Methanogenic archaea were found only in soil with pH between 10.0 and 10.3. Retrieved methanogenic archaea belonged to the Methanosarcinales and Methanomicrobiales orders. The comparison of the archaeal community structures considering phylogenetic information (UniFrac distances) clearly clustered the communities by pH. PMID:26074731

  7. Diversity of Arsenate Respiratory Reductase Genes Along Gradients of Arsenate and Arsenite Within Hypersaline, Alkaline Sediments

    NASA Astrophysics Data System (ADS)

    Saltikov, C. W.; Nilsen, J.; Oremland, R. S.; Kulp, T. R.; Hoeft, S. E.; Miller, L. G.; Switzer Blum, J.; Baesman, S.; Han, S.; Lanoil, B.

    2005-12-01

    There are several soda lakes in western United States that contain high arsenic concentrations (up to 4 mM total As). Interestingly, these lakes have high rates of anaerobic arsenate reduction, which is catalyzed by arsenate respiring prokaryotes. Several cultured arsenate respiring prokaryotes have been shown to respire and reduce arsenate via a membrane-associated enzyme, ArrA. This enzyme is present in many diverse arsenate respiring prokaryotes. To investigate arsenate respiring microbial communities within these extreme environments, we used functional gene analysis to detect the presence, abundance, and diversity of the arrA gene in core samples collected from two arsenic enriched, hypersaline, alkaline lakes, Mono Lake and Searles Lake. Each sample exhibited concentration gradients for dissolved arsenic species and oxygen. Porewater arsenite concentration increased with depth and was correlated with oxygen depletion. To investigate the depth dependency of the arrA gene in these core samples we utilized the Malasarn et al. (2004) polymerase chain reaction (PCR) primers to detect a partial arrA gene fragment in nucleic acids extracted from sediment samples. The arrA gene fragment was detected only in the top 1-2 cm of the Mono Lake core and no detection was observed in the Searles Lake homogenized core. After the primers were redesigned to include the nucleotide codon bias for haloalkaliphilic archaea ( Halobacterium), the arrA gene fragments could be detected at each depth interval throughout the Mono Lake core and in the homogenized core of Searles Lake. Work is currently focused on characterizing the diversity and abundance of the arrA gene fragments obtained in each core sample and at different depths. Although no haloalkaliphilic arsenate respiring archaea have been isolated to date, these results suggest that the arrA gene fragments detected in these soda lakes may be of archaeal origins.

  8. Complete genome sequence of Desulfurivibrio alkaliphilus strain AHT2(T), a haloalkaliphilic sulfidogen from Egyptian hypersaline alkaline lakes.

    PubMed

    Melton, Emily Denise; Sorokin, Dimitry Y; Overmars, Lex; Chertkov, Olga; Clum, Alicia; Pillay, Manoj; Ivanova, Natalia; Shapiro, Nicole; Kyrpides, Nikos C; Woyke, Tanja; Lapidus, Alla L; Muyzer, Gerard

    2016-01-01

    Desulfurivibrio alkaliphilus strain AHT2(T) is a strictly anaerobic sulfidogenic haloalkaliphile isolated from a composite sediment sample of eight hypersaline alkaline lakes in the Wadi al Natrun valley in the Egyptian Libyan Desert. D. alkaliphilus AHT2(T) is Gram-negative and belongs to the family Desulfobulbaceae within the Deltaproteobacteria. Here we report its genome sequence, which contains a 3.10 Mbp chromosome. D. alkaliphilus AHT2(T) is adapted to survive under highly alkaline and moderately saline conditions and therefore, is relevant to the biotechnology industry and life under extreme conditions. For these reasons, D. alkaliphilus AHT2(T) was sequenced by the DOE Joint Genome Institute as part of the Community Science Program. PMID:27617057

  9. New insights into microbially induced sedimentary structures in alkaline hypersaline El Beida Lake, Wadi El Natrun, Egypt

    NASA Astrophysics Data System (ADS)

    Taher, Amany G.; Abdel-Motelib, Ali

    2015-10-01

    Microbially induced sedimentary structures (MISS) were studied in detail in the alkaline hypersaline El Beida Lake of Wadi El Natrun in the western desert sector of Egypt, based on field observations and sampling performed in 2013 and 2014. Geomorphologically, the lake can be subdivided into three zones, each with characteristic sedimentary and biosedimentary structures. The marginal elevated zone that borders the lake is characterized by thick blocky crusts devoid of microbial mats. The middle-lower supratidal zone has luxuriant microbial mats associated with knotty surfaces, mat cracks and wrinkle structures. A zone of ephemeral shallow pools and channels is characterized by reticulate surfaces, pinnacle mats, sieve-like surfaces, gas domes and mat chips. In the microbial mats, authigenic minerals include thenardite Na2SO4, trona Na3(CO3)(HCO3)•2H2O and halite NaCl. Scanning electron microscopy (SEM) analyses revealed that the minerals are closely associated with the MISS, suggesting some influence of microorganisms on mineral precipitation. Complex interactions between regional hydrological cycles and diagenetic processes imply low preservation potential. MISS signatures of such saline lakes can serve as key analogues for interpreting the geologic record.

  10. Water miscible mono alcohols' effect on the proteolytic performance of Bacillus clausii serine alkaline protease.

    PubMed

    Duman, Yonca Avci; Kazan, Dilek; Denizci, Aziz Akin; Erarslan, Altan

    2014-01-01

    In this study, our investigations showed that the increasing concentrations of all examined mono alcohols caused a decrease in the Vm, kcat and kcat/Km values of Bacillus clausii GMBE 42 serine alkaline protease for casein hydrolysis. However, the Km value of the enzyme remained almost the same, which was an indicator of non-competitive inhibition. Whereas inhibition by methanol was partial non-competitive, inhibition by the rest of the alcohols tested was simple non-competitive. The inhibition constants (KI) were in the range of 1.32-3.10 M, and the order of the inhibitory effect was 1-propanol>2-propanol>methanol>ethanol. The ΔG(≠) and ΔG(≠)E-T values of the enzyme increased at increasing concentrations of all alcohols examined, but the ΔG(≠)ES value of the enzyme remained almost the same. The constant Km and ΔG(≠)ES values in the presence and absence of mono alcohols indicated the existence of different binding sites for mono alcohols and casein on enzyme the molecule. The kcat of the enzyme decreased linearly by increasing log P and decreasing dielectric constant (D) values, but the ΔG(≠) and ΔG(≠)E-T values of the enzyme increased by increasing log P and decreasing D values of the reaction medium containing mono alcohols. PMID:24092453

  11. Dissimilatory arsenate and sulfate reduction in sediments of two hypersaline, arsenic-rich soda lakes: Mono and Searles Lakes, California

    USGS Publications Warehouse

    Kulp, T.R.; Hoeft, S.E.; Miller, L.G.; Saltikov, C.; Murphy, J.N.; Han, S.; Lanoil, B.; Oremland, R.S.

    2006-01-01

    A radioisotope method was devised to study bacterial respiratory reduction of arsenate in sediments. The following two arsenic-rich soda lakes in California were chosen for comparison on the basis of their different salinities: Mono Lake (???90 g/liter) and Searles Lake (???340 g/liter). Profiles of arsenate reduction and sulfate reduction were constructed for both lakes. Reduction of [73As] arsenate occurred at all depth intervals in the cores from Mono Lake (rate constant [k] = 0.103 to 0.04 h-1) and Searles Lake (k = 0.012 to 0.002 h-1), and the highest activities occurred in the top sections of each core. In contrast, [35S] sulfate reduction was measurable in Mono Lake (k = 7.6 ?? 104 to 3.2 ?? 10-6 h-1) but not in Searles Lake. Sediment DNA was extracted, PCR amplified, and separated by denaturing gradient gel electrophoresis (DGGE) to obtain phylogenetic markers (i.e., 16S rRNA genes) and a partial functional gene for dissimilatory arsenate reduction (arrA). The amplified arrA gene product showed a similar trend in both lakes; the signal was strongest in surface sediments and decreased to undetectable levels deeper in the sediments. More arrA gene signal was observed in Mono Lake and was detectable at a greater depth, despite the higher arsenate reduction activity observed in Searles Lake. A partial sequence (about 900 bp) was obtained for a clone (SLAS-3) that matched the dominant DGGE band found in deeper parts of the Searles Lake sample (below 3 cm), and this clone was found to be closely related to SLAS-1, a novel extremophilic arsenate respirer previously cultivated from Searles Lake. Copyright ?? 2006, American Society for Microbiology. All Rights Reserved.

  12. Drilling the Mediterranean Messinian Evaporites to Answer Key Questions Related to Massive Microbial Dolomite Formation under Hypersaline Alkaline Conditions

    NASA Astrophysics Data System (ADS)

    McKenzie, Judith A.; Bontognali, Tomaso R. R.; Vasconcelos, Crisogono

    2014-05-01

    Deep-sea drilling in the Mediterranean during DSSP Leg 13 in 1970 revealed the basin-wide occurrence of a Messinian evaporite formation. This spectacular discovery was pursued further during a subsequent drilling program, DSDP Leg 42A, in 1975, which was designed, in part, to obtain continuous cores to study the evolution of the salinity crisis itself (Hsü, Montadert, et al., 1978). Specifically, drilling at a water depth of 4,088 m in the Ionian Sea, DSDP Site 374: Messina Abyssal Plain, penetrated about 80 m into the uppermost part of the Messinian upper evaporite formation. The sedimentary sequence comprises dolomitic mudstone overlying dolomitic mudstone/gypsum cycles, which in turn overlie anhydrite and halite. The non-fossiliferous dolomitic mudstone is generally rich in organic carbon, with TOC values ranging from 0.9% to 5.3%, of possible marine origin with a good source rock potential. Commonly laminated dolomitic mudstones contain preserved filamentous cyanobacterial remains suggesting that conditions were conducive for microbial mat growth. The Ca-dolomite, composed of fine-grained anhedral crystals in the size range of 2-4 μm, is probably a primary precipitate. The unusual interstitial brines of the dolomitic mudstone units have very high alkalinities with a low pH of 5 to 6. The Mg concentration (2250 mmoles/l) is extremely elevated, whereas the Ca concentration is nearly zero. Finally, the drilled evaporite sedimentary sequence was interpreted as being deposited in an alkaline lake/sea ("Lago Mare"), which covered the area during the latest Messinian. Projecting forward 40 years since the DSDP Leg 42A drilling campaign, research into the factors controlling dolomite precipitation under Earth surface conditions has led to the development of new models involving the metabolism of microorganisms and associated biofilms to overcome the kinetic inhibitions associated with primary dolomite precipitation. Together with laboratory experiments, microbial

  13. Ca isotope fractionation in a high-alkalinity lake system: Mono Lake, California

    NASA Astrophysics Data System (ADS)

    Nielsen, Laura C.; DePaolo, Donald J.

    2013-10-01

    Precipitation of calcium carbonate minerals from aqueous solutions causes surface-controlled kinetic stable Ca isotope fractionation. The magnitude of fractionation depends on the relative rates of ion attachment to and detachment from the mineral surface, which in turn is predicted to depend on both the saturation state and the solution stoichiometry or the Ca:CO32- activity ratio. Experimental studies have not directly investigated the effects of varying solution stoichiometry on calcium isotope partitioning during calcite or aragonite growth, but natural alkaline lake systems such as Mono Lake, California provide a test bed for the hypothesized stoichiometry dependence. Mono Lake has a Ca:CO32- activity ratio of about 0.0001, seven orders of magnitude lower than ocean water and typical terrestrial freshwater. We present chemical and isotopic measurements of streams, springs, lake water, and precipitated carbonates from the Mono Basin that yield evidence of stoichiometry-dependent Ca isotope fractionation during calcite, aragonite and Mg-calcite precipitation from the alkaline lake water. To estimate the Ca isotope fractionation factors, it is necessary to characterize the lake Ca balance and constrain the variability of lake water chemistry both spatially and temporally. Streams and springs supply Ca to the lake, and a substantial fraction of this supply is precipitated along the lake shore to form tufa towers. Lake water is significantly supersaturated with respect to carbonate minerals, so CaCO3 also precipitates directly from the water column to form carbonate-rich bottom sediments. Growth rate inhibition by orthophosphate likely preserves the high degree of supersaturation in the lake. Strontium isotope ratios are used to estimate the proportions of fresh and alkaline lake water from which each solid carbonate sample precipitated. Carbonate minerals that precipitate directly from lake water (low Ca:CO32-) experience relatively large Ca isotope fractionation

  14. Bacterial biodiversity from anthropogenic extreme environments: a hyper-alkaline and hyper-saline industrial residue contaminated by chromium and iron.

    PubMed

    Brito, Elcia M S; Piñón-Castillo, Hilda A; Guyoneaud, Rémy; Caretta, César A; Gutiérrez-Corona, J Félix; Duran, Robert; Reyna-López, Georgina E; Nevárez-Moorillón, G Virginia; Fahy, Anne; Goñi-Urriza, Marisol

    2013-01-01

    Anthropogenic extreme environments are among the most interesting sites for the bioprospection of extremophiles since the selection pressures may favor the presence of microorganisms of great interest for taxonomical and astrobiological research as well as for bioremediation technologies and industrial applications. In this work, T-RFLP and 16S rRNA gene library analyses were carried out to describe the autochthonous bacterial populations from an industrial waste characterized as hyper-alkaline (pH between 9 and 14), hyper-saline (around 100 PSU) and highly contaminated with metals, mainly chromium (from 5 to 18 g kg(-1)) and iron (from 2 to 108 g kg(-1)). Due to matrix interference with DNA extraction, a protocol optimization step was required in order to carry out molecular analyses. The most abundant populations, as evaluated by both T-RFLP and 16S rRNA gene library analyses, were affiliated to Bacillus and Lysobacter genera. Lysobacter related sequences were present in the three samples: solid residue and lixiviate sediments from both dry and wet seasons. Sequences related to Thiobacillus were also found; although strains affiliated to this genus are known to have tolerance to metals, they have not previously been detected in alkaline environments. Together with Bacillus (already described as a metal reducer), such organisms could be of use in bioremediation technologies for reducing chromium, as well as for the prospection of enzymes of biotechnological interest. PMID:22350256

  15. Analysis of ammonia-oxidizing bacteria from hypersaline Mono Lake, California, on the basis of 16S rRNA sequences.

    PubMed

    Ward, B B; Martino, D P; Diaz, M C; Joye, S B

    2000-07-01

    Ammonia-oxidizing bacteria were detected by PCR amplification of DNA extracted from filtered water samples throughout the water column of Mono Lake, California. Ammonia-oxidizing members of the beta subdivision of the division Proteobacteria (beta-subdivision Proteobacteria) were detected using previously characterized PCR primers; target sequences were detected by direct amplification in both surface water and below the chemocline. Denaturing gradient gel electrophoresis analysis indicated the presence of at least four different beta-subdivision ammonia oxidizers in some samples. Subsequent sequencing of amplified 16S rDNA fragments verified the presence of sequences very similar to those of cultured Nitrosomonas strains. Two separate analyses, carried out under different conditions (different reagents, locations, PCR machines, sequencers, etc.), 2 years apart, detected similar ranges of sequence diversity in these samples. It seems likely that the physiological diversity of nitrifiers exceeds the diversity of their ribosomal sequences and that these sequences represent members of the Nitrosomonas europaea group that are acclimated to alkaline, high-salinity environments. Primers specific for Nitrosococcus oceanus, a marine ammonia-oxidizing bacterium in the gamma subdivision of the Proteobacteria, did not amplify target from any samples. PMID:10877781

  16. Carbonate microbialites and hardgrounds from Manito Lake, an alkaline, hypersaline lake in the northern Great Plains of Canada

    NASA Astrophysics Data System (ADS)

    Last, Fawn M.; Last, William M.; Halden, Norman M.

    2010-03-01

    Manito Lake is a large, perennial, Na-SO 4 dominated saline to hypersaline lake located in the northern Great Plains of western Canada. Significant water level decrease over the past several decades has led to reduction in volume and surface area, as well as an increase in salinity. The salinity has increased from 10 ppt to about 50 ppt TDS. This decrease in water level has exposed large areas of nearshore microbialites. These organogenic structures range in size from several cm to over a meter and often form large bioherms several meters high. They have various external morphologies, vary in mineralogical composition, and show a variety of internal fabrics from finely laminated to massive. In addition to microbiolities and bioherms, the littoral zone of Manito Lake contains a variety of carbonate hardgrounds, pavements, and cemented clastic sediments. Dolomite and aragonite are the most common minerals found in these shoreline structures, however, calcite after ikaite, monohydrocalcite, magnesian calcite, and hydromagnesite are also present. The dolomite is nonstoichiometric and calcium-rich; the magnesian calcite has about 17 mol% MgCO 3. AMS radiocarbon dating of paired organic matter and endogenic carbonate material confirms little or no reservoir affect. Although there is abundant evidence for modern carbonate mineral precipitation and microbialite formation, most of the larger microbialites formed between about 2300 and 1000 cal BP, whereas the hardgrounds, cements, and laminated crusts formed about 1000-500 cal BP.

  17. Genome sequence of Sphingomonas sp. S17, isolated from an alkaline, hyperarsenic, and hypersaline volcano-associated lake at high altitude in the Argentinean Puna.

    PubMed

    Farias, Maria Eugenia; Revale, Santiago; Mancini, Estefania; Ordoñez, Omar; Turjanski, Adrian; Cortez, Néstor; Vazquez, Martin P

    2011-07-01

    The high-altitude Andean lakes (HAAL) in the Argentinean Puna-high Andes region represent an almost unexplored ecosystem exposed to extreme conditions (high UV irradiation, hypersalinity, drastic temperature changes, desiccation, and high pH). Here we present the first genome sequence, a Sphingomonas sp., isolated from this extreme environment. PMID:21602338

  18. Genome Sequence of Sphingomonas sp. S17, Isolated from an Alkaline, Hyperarsenic, and Hypersaline Volcano-Associated Lake at High Altitude in the Argentinean Puna ▿

    PubMed Central

    Farias, Maria Eugenia; Revale, Santiago; Mancini, Estefania; Ordoñez, Omar; Turjanski, Adrian; Cortez, Néstor; Vazquez, Martin P.

    2011-01-01

    The high-altitude Andean lakes (HAAL) in the Argentinean Puna-high Andes region represent an almost unexplored ecosystem exposed to extreme conditions (high UV irradiation, hypersalinity, drastic temperature changes, desiccation, and high pH). Here we present the first genome sequence, a Sphingomonas sp., isolated from this extreme environment. PMID:21602338

  19. Anaerobic bacteria from hypersaline environments.

    PubMed Central

    Ollivier, B; Caumette, P; Garcia, J L; Mah, R A

    1994-01-01

    Strictly anaerobic halophiles, namely fermentative, sulfate-reducing, homoacetogenic, phototrophic, and methanogenic bacteria are involved in the oxidation of organic carbon in hypersaline environments. To date, six anaerobic fermentative genera, containing nine species, have been described. Two of them are homoacetogens. Six species belong to the family Haloanaerobiaceae, as indicated by their unique 16S rRNA oligonucleotide sequences. Desulfohalobium retbaense and Desulfovibrio halophilus represent the only two moderately halophilic sulfate reducers so far reported. Among anoxygenic phototrophic anaerobes, a few purple bacteria with optimal growth at salinities between 6 and 11% NaCl have been isolated from hypersaline habitats. They belong to the genera Rhodospirillum, Chromatium, Thiocapsa, and Ectothiorhodospira. The commonest organisms isolated so far are Chromatium salexigens, Thiocapsa halophila, and Rhodospirillum salinarum. Extremely halophilic purple bacteria have most commonly been isolated from alkaline brines and require about 20 to 25% NaCl for optimal growth. They belong to the family Ectothiorodhospiraceae. Their osmoregulation involves synthesis or uptake of compatible solutes such as glycine-betaine that accumulate in their cytoplasm. The existence of methanogens in hypersaline environments is related to the presence of noncompetitive substrates such as methylamines, which originate mainly from the breakdown of osmoregulatory amines. Methanogenesis probably does not contribute to the mineralization of carbohydrates at NaCl concentrations higher than 15%. Above this concentration, sulfate reduction is probably the main way to oxidize H2 (although at rates too low to use up all the H2 formed) and occupies a terminal function kn the degradation of carbohydrates. Three genera and five species of halophilic methylotrophic methanogens have been reported. A bloom of phototrophic bacteria in the marine salterns of Salins-de-Giraud, located on the

  20. Spatial and Temporal Variations of Microbial Biodiversity at Hypersaline Microbial Mats

    NASA Astrophysics Data System (ADS)

    Gulecal, Y.; Unsal, N.; Temel, M.

    2014-12-01

    Hypersaline environments, such as hypersaline lakes are interesting sources with considerable potential for the isolation of extremophile microorganisms adapted to severe conditions. Biodiversity in such lakes (Dead Sea, the Great Salt Lake, the Solar Lake, the Soda Lake) varies due to differences in environmental conditions and specific lake characteristics such as local climate, lake size, water depth and lake water salt composition (Kamekura 1998; Sorokin et al. 2004). In this study area, Acigol Lake is an alkaline (pH:9), hypersaline lake located at Southwest Anatolia in Turkey. The aim of study was to determine the Archaea and Bacteria in microbial mats of hypersaline lacustrine environments. In conclusion, diagnostic biosignatures for methanogens and other archaeal groups within hypersaline microbial mats were identified through genomic DNA and lipid analyses.

  1. What's Mono?

    MedlinePlus

    ... Quizzes Kids' Dictionary of Medical Words En Español What Other Kids Are Reading Back-to-School Butterflies? ... Got Homework? Here's Help White House Lunch Recipes What's Mono? KidsHealth > For Kids > What's Mono? Print A ...

  2. Arsenic speciation in Mono Lake, California: Response to seasonal stratification and anoxia

    NASA Astrophysics Data System (ADS)

    Hollibaugh, James T.; Carini, Steve; Gürleyük, Hakan; Jellison, Robert; Joye, Samantha B.; LeCleir, Gary; Meile, Christof; Vasquez, Lydia; Wallschläger, Dirk

    2005-04-01

    Mono Lake is a closed-basin, alkaline, hypersaline lake located at the western edge of the Great Basin in eastern California. We studied the distribution of arsenic (As) species in the water column of Mono Lake between February and November, 2002. This period captured the seasonal progression from winter mixing, through summer thermal stratification, to autumn overturn. Arsenic speciation was determined by ion chromatography-inductively coupled-plasma-mass spectrometry of samples preserved in the field by flash-freezing in liquid nitrogen. We found that arsenic speciation was dominated (>90%) by arsenate when oxygen was detectable. Once levels fell below 6 μmol/L O 2, arsenic speciation shifted to dominance by reduced species. Arsenate and arsenite co-occurred in a transition zone immediately below the base of the oxycline and low but significant concentrations of arsenate were occasionally detected in sulfidic hypolimnion samples. Thio-arsenic species were the dominant form of As found in sulfidic waters. Maxima of thio-arsenic species with stoichiometries consistent with mono-, di- and trithio-arsenic occurred in succession as sulfide concentration increased. A compound with a stoichiometry consistent with trithio-arsenic was the dominant As species (˜50% of total As) in high sulfide (2 mmol/L) bottom water. Lower concentrations of total As in bottom water relative to surface water suggest precipitation of As/S mineral phases in response to sulfide accumulation during prolonged anoxia.

  3. Yeast diversity in hypersaline habitats.

    PubMed

    Butinar, L; Santos, S; Spencer-Martins, I; Oren, A; Gunde-Cimerman, N

    2005-03-15

    Thus far it has been considered that hypersaline natural brines which are subjected to extreme solar heating, do not contain non-melanized yeast populations. Nevertheless we have isolated yeasts in eight different salterns worldwide, as well as from the Dead Sea, Enriquillo Lake (Dominican Republic) and the Great Salt Lake (Utah). Among the isolates obtained from hypersaline waters, Pichia guilliermondii, Debaryomyces hansenii, Yarrowia lipolytica and Candida parapsilosis are known contaminants of low water activity food, whereas Rhodosporidium sphaerocarpum, R. babjevae, Rhodotorula laryngis, Trichosporon mucoides, and a new species resembling C. glabrata were not known for their halotolerance and were identified for the first time in hypersaline habitats. Moreover, the ascomycetous yeast Metschnikowia bicuspidata, known to be a parasite of the brine shrimp, was isolated as a free-living form from the Great Salt Lake brine. In water rich in magnesium chloride (bitterns) from the La Trinitat salterns (Spain), two new species provisionally named C. atmosphaerica - like and P. philogaea - like were discovered. PMID:15766773

  4. Mono Test

    MedlinePlus

    ... services. Advertising & Sponsorship: Policy | Opportunities PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be ... Mononucleosis (Mono) Test Share this page: Was this page helpful? Also ...

  5. Biodegradation of petroleum hydrocarbons in hypersaline environments.

    PubMed

    Martins, Luiz Fernando; Peixoto, Raquel Silva

    2012-07-01

    Literature on hydrocarbon degradation in extreme hypersaline media presents studies that point to a negative effect of salinity increase on hydrocarbonoclastic activity, while several others report an opposite tendency. Based on information available in the literature, we present a discussion on the reasons that justify these contrary results. Despite the fact that microbial ability to metabolize hydrocarbons is found in extreme hypersaline media, indeed some factors are critical for the occurrence of hydrocarbon degradation in such environments. How these factors affect hydrocarbon degradation and their implications for the assessment of hydrocarbon biodegradation in hypersaline environments are presented in this review. PMID:24031900

  6. Biodegradation of petroleum hydrocarbons in hypersaline environments

    PubMed Central

    Martins, Luiz Fernando; Peixoto, Raquel Silva

    2012-01-01

    Literature on hydrocarbon degradation in extreme hypersaline media presents studies that point to a negative effect of salinity increase on hydrocarbonoclastic activity, while several others report an opposite tendency. Based on information available in the literature, we present a discussion on the reasons that justify these contrary results. Despite the fact that microbial ability to metabolize hydrocarbons is found in extreme hypersaline media, indeed some factors are critical for the occurrence of hydrocarbon degradation in such environments. How these factors affect hydrocarbon degradation and their implications for the assessment of hydrocarbon biodegradation in hypersaline environments are presented in this review. PMID:24031900

  7. Hydrocarbon Biodegradation in Hypersaline Environments

    PubMed Central

    Ward, David M.; Brock, T. D.

    1978-01-01

    When mineral oil, hexadecane, and glutamate were added to natural samples of varying salinity (3.3 to 28.4%) from salt evaporation ponds and Great Salt Lake, Utah, rates of metabolism of these compounds decreased as salinity increased. Rate limitations did not appear to relate to low oxygen levels or to the availability of organic nutrients. Some oxidation of l-[U-14C]glutamic acid occurred even at extreme salinities, whereas oxidation of [1-14C]hexadecane was too low to be detected. Gas chromatographic examination of hexane-soluble components of tar samples from natural seeps at Rozel Point in Great Salt Lake demonstrated no evidence of biological oxidation of isoprenoid alkanes subject to degradation in normal environments. Some hexane-soluble components of the same tar were altered by incubation in a low-salinity enrichment culture inoculated with garden soil. Attempts to enrich for microorganisms in saline waters able to use mineral oil as a sole source of carbon and energy were successful below, but not above, about 20% salinity. This study strongly suggests a general reduction of metabolic rate at extreme salinities and raises doubt about the biodegradation of hydrocarbons in hypersaline environments. PMID:16345276

  8. Hypersaline Microbial Mat Lipid Biomarkers

    NASA Technical Reports Server (NTRS)

    Jahnke, Linda L.; Embaye, Tsegereda; Turk, Kendra A.; Summons, Roger E.

    2002-01-01

    Lipid biomarkers and compound specific isotopic abundances are powerful tools for studies of contemporary microbial ecosystems. Knowledge of the relationship of biomarkers to microbial physiology and community structure creates important links for understanding the nature of early organisms and paleoenvironments. Our recent work has focused on the hypersaline microbial mats in evaporation ponds at Guerrero Negro, Baja California Sur, Mexico. Specific biomarkers for diatoms, cyanobacteria, archaea, green nonsulfur (GNS), sulfate reducing, sulfur oxidizing and methanotrophic bacteria have been identified. Analyses of the ester-bound fatty acids indicate a highly diverse microbial community, dominated by photosynthetic organisms at the surface. The delta C-13 of cyanobacterial biomarkers such as the monomethylalkanes and hopanoids are consistent with the delta C-13 measured for bulk mat (-10%o), while a GNS biomarker, wax esters (WXE), suggests a more depleted delta C-13 for GNS biomass (-16%o). This isotopic relationship is different than that observed in mats at Octopus Spring, Yellowstone National Park (YSNP) where GNS appear to grow photoheterotrophic ally. WXE abundance, while relatively low, is most pronounced in an anaerobic zone just below the cyanobacterial layer. The WXE isotope composition at GN suggests that these bacteria utilize photoautotrophy incorporating dissolved inorganic carbon (DIC) via the 3-hydroxypropionate pathway using H2S or H2.

  9. Spirochaeta americana sp. nov.: A New Haloalkaliphilic, Obligately Anaerobic Spirochete Isolated from Soda Mono Lake, California

    NASA Technical Reports Server (NTRS)

    Hoover, Richard B.; Pikuta, Elena V.; Marsic, Damien; Whitman, William B.; Tang, Jane; Krader, Paul; Six, N. Frank (Technical Monitor)

    2002-01-01

    A novel obligately anaerobic, mesophilic, haloalkaliphilic spirochete, strain ASpG1, was isolated from sediments of the alkaline, hypersaline Mono Lake in California, U.S.A. The gram-negative cells are motile and spirochete-shaped with sizes of 0.22 x 10-15 micron. Growth was observed over the temperature range of 10 C to 44 C (optimum 37 C), NaCl concentration range of greater than 1 - 12 % (wt/vol) (optimum 3%), and pH range 7.5 - 10.5 (optimum pH 9.5). The novel isolate is strictly alkaliphilic, requires high concentrations of carbonate in the medium, and is capable of utilizing D-glucose, fructose, maltose, sucrose, starch, and D-mannitol. Main end products of glucose fermentation are: H2, acetate, ethanol, and formate. Strain AspG1 is resistant to kanamycin, but sensitive to chloramphenicol, gentamycin and tetracycline. The G+C content of its DNA is 58.5 mol%. On the basis of its physiological and molecular properties, the isolate appears to be a novel species among the genus Spirochaeta; and the name Spirochaeta americana sp. nov., is proposed for the taxon (type strain ASpG1(sup T) = ATCC BAA_392(sup T) = DSMZ 14872(sup T)).

  10. Heterotrophic Protists in Hypersaline Microbial Mats and Deep Hypersaline Basin Water Columns

    PubMed Central

    Edgcomb, Virginia P.; Bernhard, Joan M.

    2013-01-01

    Although hypersaline environments pose challenges to life because of the low water content (water activity), many such habitats appear to support eukaryotic microbes. This contribution presents brief reviews of our current knowledge on eukaryotes of water-column haloclines and brines from Deep Hypersaline Anoxic Basins (DHABs) of the Eastern Mediterranean, as well as shallow-water hypersaline microbial mats in solar salterns of Guerrero Negro, Mexico and benthic microbialite communities from Hamelin Pool, Shark Bay, Western Australia. New data on eukaryotic diversity from Shark Bay microbialites indicates eukaryotes are more diverse than previously reported. Although this comparison shows that eukaryotic communities in hypersaline habitats with varying physicochemical characteristics are unique, several groups are commonly found, including diverse alveolates, strameonopiles, and fungi, as well as radiolaria. Many eukaryote sequences (SSU) in both regions also have no close homologues in public databases, suggesting that these environments host unique microbial eukaryote assemblages with the potential to enhance our understanding of the capacity of eukaryotes to adapt to hypersaline conditions. PMID:25369746

  11. The Archaea of a Hypersaline Microbial Mat

    NASA Astrophysics Data System (ADS)

    Robertson, C.; Spear, J. R.; Pace, N. R.

    2006-12-01

    The overarching goal of this work is to describe and understand the organismal composition within the domain Archaea for the microbial ecosystem of a hypersaline microbial mat. Sea salt is crystallized by solar evaporation at North America's largest saltworks, the Exportadora de Sal, in Guerrero Negro, Baja California Sur. Sea water flows through a series of evaporative basins with an increase in salinity until saturation is reached and halite crystallization begins. Several of these ponds are underlined with thick microbial mats. To date, it has not been known what kinds of organisms comprise these complex microbial ecosystems. Here, we report a survey of the stratified microbial communities for the distribution of representatives of Archaea in layers of the mats. This survey uses molecular approaches, based on cloning and sequencing of SSU rRNA genes for phylogenetic analyses, to determine the nature and extent of archaeal diversity that constitute these ecosystems. We compiled an altogether new phylogenetic backbone for the domain Archaea and placed representative sequences from this hypersaline analysis onto that framework. Analyses to date indicate the ubiquitous dominance of uncultured organisms of phylogenetic kinds not generally thought to be associated with hypersaline environments. Collectively, the results indicate that the diversity of life is extensive even in this seemingly inhospitable "extreme" environment.

  12. Microbial Fuel Cell as Life Detector: Arsenic Cycling in Hypersaline Environments

    NASA Astrophysics Data System (ADS)

    Miller, L. G.; Blum, J. S.; Oremland, R. S.

    2006-12-01

    Detection of extant life on Mars or Europa is a future goal of exobiology. For the present, biosignatures arising from life in extreme environments on Earth suggest how to search for life elsewhere. One such biosignature is the electrical current derived from the metabolic activity of microorganisms, which may be measured using microbial fuel cells (MFCs). MFCs generate electricity by coupling bacterially mediated redox transformations to electrochemical reactions through a circuit. Our laboratory fuel cell employs solid graphite electrodes and uses a proton exchange membrane to separate anode (anaerobic) and cathode (aerobic) chambers. Mineral salts media are circulated by peristaltic pump through the chambers and through temperature-controlled reservoirs that are sparged with nitrogen (anode) or oxygen (cathode). In experiments with pure cultures, bacteria reduced arsenate to arsenite in the anode chamber, and produced electrical power in the process. Power production was sustained in the MFC only while bacteria were active. An arsenate respiring bacterium, Bacillus selenitireducens, isolated from moderately-hypersaline Mono Lake, CA grew on lactate using arsenate as the electron acceptor and also grew without arsenate, using the anode as the electron acceptor. Power densities (per unit area of anode surface) of 60 μW m-2 were achieved during growth without arsenate. Less power (3 μW m-2) was produced when arsenate was available because arsenate acted as an alternate electron acceptor to the anode. Another arsenate respiring bacterium, strain SLAS-1, isolated from extremely-hypersaline Searles Lake, CA respired lactate and reduced arsenate in the MFC, albeit more slowly. An arsenite oxidizing bacterium, Alkalilimnicola ehrlichii, isolated from Mono Lake will also be tested for its ability to generate electricity before proceeding to an examination of biocurrent production using natural sediments and waters from Mono Lake and Searles Lake.

  13. Spirochaeta americana sp. nov., a new haloalkaliphilic, obligately anaerobic spirochaete isolated from soda Mono Lake in California

    NASA Technical Reports Server (NTRS)

    Hoover, Richard B.; Pikuta, Elena V.; Bej, Asim K.; Marsic, Damien; Whitman, William B.; Tang, Jane; Krader, Paul

    2003-01-01

    A novel, obligately anaerobic, mesophilic, haloalkaliphilic spirochaete, strain ASpG1(T), was isolated from sediments of the alkaline, hypersaline Mono Lake in California, USA. Cells of the Gram-negative strain were motile and spirochaete-shaped with sizes of 0.2-0.22 x 8-18 microm. Growth of the strain was observed between 10 and 44 degrees C (optimum 37 degrees C), in 2-12% (w/v) NaCl (optimum 3% NaCl) and between pH 8 and 10.5 (optimum pH 9.5). The novel strain was strictly alkaliphilic, required high concentrations of carbonates in the medium and was capable of utilizing D-glucose, fructose, maltose, sucrose, starch and D-mannitol. End products of glucose fermentation were H2, acetate, ethanol and formate. Strain ASpG(T) was resistant to kanamycin and rifampicin, but sensitive to gentamicin, tetracycline and chloramphenicol. The G + C content of its DNA was 58.5 mol%. DNA-DNA hybridization analysis of strain ASpG1(T) with its most closely related species, Spirochaeta alkalica Z-7491(T), revealed a hybridization value of only 48.7%. On the basis of its physiological and molecular properties, strain ASpG1(T) appears to represent a novel species of the genus Spirochaeta, for which the name Spirochaeta americana is proposed (type strain ASpG1(T) =ATCC BAA-392(T) = DSM 14872(T)).

  14. Investigations of Methane Production in Hypersaline Environments

    NASA Technical Reports Server (NTRS)

    Bebout, Brad M.

    2015-01-01

    The recent reports of methane in the atmosphere of Mars, as well as the findings of hypersaline paleo-environments on that planet, have underscored the need to evaluate the importance of biological (as opposed to geological) trace gas production and consumption. Methane in the atmosphere of Mars may be an indication of life but might also be a consequence of geologic activity and/or the thermal alteration of ancient organic matter. Hypersaline environments have now been reported to be extremely likely in several locations in our solar system, including: Mars, Europa, and Enceladus. Modern hypersaline microbial mat communities, (thought to be analogous to those present on the early Earth at a period of time when Mars was experiencing very similar environmental conditions), have been shown to produce methane. However, very little is known about the physical and/or biological controls imposed upon the rates at which methane, and other important trace gases, are produced and consumed in these environments. We describe here the results of our investigations of methane production in hypersaline environments, including field sites in Chile, Baja California Mexico, California, USA and the United Arab Emirates. We have measured high concentrations of methane in bubbles of gas produced both in the sediments underlying microbial mats, as well as in areas not colonized by microbial mats in the Guerrero Negro hypersaline ecosystem, Baja California Mexico, in Chile, and in salt ponds on the San Francisco Bay. The carbon isotopic (d13C) composition of the methane in the bubbles exhibited an extremely wide range of values, (ca. -75 per mille ca. -25 per mille). The hydrogen isotopic composition of the methane (d2H) ranged from -60 to -30per mille and -450 to -350per mille. These isotopic values are outside of the range of values normally considered to be biogenic, however incubations of the sediments in contact with these gas bubbles reveals that the methane is indeed being

  15. Substrate limitation for methanogenesis in hypersaline environments.

    PubMed

    Kelley, Cheryl A; Poole, Jennifer A; Tazaz, Amanda M; Chanton, Jeffrey P; Bebout, Brad M

    2012-02-01

    Motivated by the increasingly abundant evidence for hypersaline environments on Mars and reports of methane in its atmosphere, we examined methanogenesis in hypersaline ponds in Baja California Sur, Mexico, and in northern California, USA. Methane-rich bubbles trapped within or below gypsum/halite crusts have δ¹³C values near -40‰. Methane with these relatively high isotopic values would typically be considered thermogenic; however, incubations of crust samples resulted in the biological production of methane with similar isotopic composition. A series of measurements aimed at understanding the isotopic composition of methane in hypersaline systems was therefore undertaken. Methane production rates, as well as the concentrations and isotopic composition of the particulate organic carbon (POC), were measured. Methane production was highest from microbial communities living within gypsum crusts, whereas POC content at gypsum/halite sites was low, generally less than 1% of the total mass. The isotopic composition of the POC ranged from -26‰ to -10‰. To determine the substrates used by the methanogens, ¹³C-labeled methylamines, methanol, acetate, and bicarbonate were added to individual incubation vials, and the methane produced was monitored for ¹³C content. The main substrates used by the methanogens were the noncompetitive substrates, the methylamines, and methanol. When unlabeled trimethylamine (TMA) was added to incubating gypsum/halite crusts in increasing concentrations, the isotopic composition of the methane produced became progressively lower; the lowest methane δ¹³C values occurred when the most TMA was added (1000 μM final concentration). This decrease in the isotopic composition of the methane produced with increasing TMA concentrations, along with the high in situ methane δ¹³C values, suggests that the methanogens within the crusts are operating at low substrate concentrations. It appears that substrate limitation is decreasing

  16. Organic geochemistry and brine composition in Great Salt, Mono, and Walker Lakes

    NASA Astrophysics Data System (ADS)

    Domagalski, Joseph L.; Orem, William H.; Eugster, Hans P.

    1989-11-01

    aromatic carbon and the absence of chemical structures indicative of the lignin of vascular plants. The dissolved organic carbon of the Mono Lake pore fluids is structurally related to humic acid and is also related to carbohydrate metabolism. The alkaline pore fluids, due to high pH, solubilize high molecular weight organic matter from the sediments. This hydrophilic material is a metal complexing agent. Despite very high algal productivities, organic carbon accumulation can be low in stratified lakes if the anoxic bottom waters are hypersaline with high concentrations of sulfate ion. Labile organic matter is recycled to the water column and the sedimentary organic matter is relatively nonsusceptible to bacterial metabolism. As a result, pore-fluid dissolved organic carbon and metal-organic complexation are low.

  17. Salinity Effects on the Biogeochemical Cycles of Sulfate, Arsenate, Nitrate, and Methane in Anoxic Sediments of Mono Lake and Searles Lake, California.

    NASA Astrophysics Data System (ADS)

    Kulp, T. R.; Hoeft, S. E.; Miller, L. G.; Oremland, R. S.

    2005-12-01

    Mono Lake and Searles Lake are two members of a chain of hypersaline and alkaline soda lakes that occur in closed basins along the arid eastern escarpment of the Sierra Nevada in California. These lakes are alkaline (pH = 9.8), highly saline, and As-rich due to hydrothermal input and evaporative concentration. Mono Lake is characterized by a salinity of 90 g/L and contains 200μM dissolved As. Searles Lake, a partially-dry residual playa, exhibits salt concentrations >300 g/L (near saturation) and 3.9 mM dissolved As. We utilized 35SO4 and 73As(V) as radioactive tracers to compare sulfate and arsenate [As(V)] reductase activities at in-situ concentrations in sediment cores (25 cm depth) from Mono and Searles Lakes. Sulfate reduction activity was detected in sediments from Mono Lake, with the highest rates occurring in the upper 2 cm sediment depth. No sulfate reduction activity was observed in Searles Lake sediments, suggesting that this metabolic process may not provide sufficient energy to cope with the demands of osmoadaptation at saturated salt concentrations. Anaerobic pathways that utilize As(V) or nitrate as terminal electron acceptors are bioenergetically more favorable than sulfate reduction. Dissimilatory reduction of As(V) occurred in sediments from both lakes, with the fastest rates of As(V) reduction occurring at 3 cm sediment depth. We conducted additional experiments with As- or nitrate-amended slurries of Searles Lake sediment prepared in artificial media that mimicked lake water chemistry over a range of total salinities. Slurries were sampled periodically and analyzed to determine the rate of As(V) reduction or denitrification at each salinity. Methane production was also monitored in the headspace of As(V)-amended and non-amended slurries. As(V) and nitrate reduction rates, as well as methane production, demonstrated an inverse relationship with total salinity over the range of 50 - 346 g/L. These data suggest that halophilic bacteria capable of

  18. Bacterial dissimilatory reduction of arsenate and sulfate in meromictic Mono Lake, California

    USGS Publications Warehouse

    Oremland, R.S.; Dowdle, P.R.; Hoeft, S.; Sharp, J.O.; Schaefer, J.K.; Miller, L.G.; Switzer, Blum J.; Smith, R.L.; Bloom, N.S.; Wallschlaeger, D.

    2000-01-01

    The stratified (meromictic) water column of alkaline and hypersaline Mono Lake, California, contains high concentrations of dissolved inorganic arsenic (~200 ??mol/L). Arsenic speciation changes from arsenate [As (V)] to arsenite [As (III)] with the transition from oxic surface waters (misolimnion) to anoxic bottom waters (monimolimnion). A radioassay was devised to measure the reduction of 73As (V) to 73As (III) and tested using cell suspensions of the As (V)-respiring Bacillus selenitireducens, which completely reduced the 73As (V). In field experiments, no significant activity was noted in the aerobic mixolimnion waters, but reduction of 73As (V) to 73As (III) was observed in all the monimolimnion samples. Rate constants ranged from 0.02 to 0.3/day, with the highest values in the samples from the deepest depths (24 and 28 m). The highest activities occurred between 18 and 21 m, where As (V) abundant (rate, ~5.9 ??mol/L per day). In contrast, sulfate reduction occurred at depths below 21 m, with the highest rates attained at 28 m (rate, ~2.3 ??mol/L per day). These results indicate that As (V) ranks second in importance, after sulfate, as an electron acceptor for anaerobic bacterial respiration in the water column. Annual arsenate respiration may mineralize as much as 14.2% of the pelagic photosynthetic carbon fixed during meromixis. When combined with sulfate-reduction data, anaerobic respiration in the water column can mineralize 32-55% of this primary production. As lakes of this type approach salt saturation, As (V) can become the most important electron acceptor for the biogeochemical cycling of carbon. Copyright (C) 2000 Elsevier Science Ltd.

  19. Mono Lake Excursion Reviewed

    NASA Astrophysics Data System (ADS)

    Liddicoat, J. C.; Coe, R. S.

    2007-05-01

    The Mono Lake Excursion as recorded in the Mono Basin, CA, has an older part that is about negative 30 degrees inclination and about 300 degrees declination during low relative field intensity. Those paleomagnetic directions are closely followed by greater than 80 degrees positive inclination and east declination of about 100 degrees during higher relative field intensity. A path of the Virtual Geomagnetic Poles (VGPs) for the older part followed from old to young forms a large clockwise loop that reaches 35 degrees N latitude and is centered at about 35 degrees E longitude. That loop is followed by a smaller one that is counterclockwise and centered at about 70 degrees N latitude and 270 degrees E longitude (Denham & Cox, 1971; Denham, 1974; Liddicoat & Coe, 1979). The Mono Lake Excursion outside the Mono Basin in western North America is recorded as nearly the full excursion at Summer Lake, OR (Negrini et al., 1984), and as the younger portion of steep positive inclination/east declination in the Lahontan Basin, NV. The overall relative field intensity during the Mono Lake Excursion in the Lahontan Basin mirrors very closely the relative field intensity in the Mono Basin (Liddicoat, 1992, 1996; Coe & Liddicoat, 1994). Using 14C and 40Ar/39Ar dates (Kent et al., 2002) and paleoclimate and relative paleointensity records (Zimmerman et al., 2006) for the Mono Lake Excursion in the Mono Basin, it has been proposed that the Mono Lake Excursion might be older than originally believed and instead be the Laschamp Excursion at about 40,000 yrs B.P. (Guillou et al., 2004). On the contrary, we favor a younger age for the Mono Lake Excursion, about 32,000 yrs B.P., using the relative paleointensity in the Mono Basin and Lahontan Basin and 14C dates from the Lahontan Basin (Benson et al., 2002). The age of about 32,000 yrs B.P. is also in accord with the age (32,000- 34,000 yrs B.P.) reported by Channell (2006) for the Mono Lake Excursion at ODP Site 919 in the Irminger Basin

  20. Bacillus arsenicoselenatis, sp. nov., and Bacillus selenitireducens, sp. nov.: Two haloalkaliphiles from Mono Lake, California that respire oxyanions of selenium and arsenic

    USGS Publications Warehouse

    Switzer, Blum J.; Burns, Bindi A.; Buzzelli, J.; Stolz, J.F.; Oremland, R.S.

    1998-01-01

    Two gram-positive anaerobic bacteria (strains E1H and MLS10) were isolated from the anoxic muds of Mono Lake, California, an alkaline, hypersaline, arsenic-rich water body. Both grew by dissimilatory reduction of As(V) to As(III) with the concomitant oxidation of lactate to acetate plus CO2. Bacillus arsenicoselenatis (strain E1H) is a spore-forming rod that also grew by dissimilatory reduction of Se(VI) to Se(IV). Bacillus selenitireducens (strain MLS 10) is a short, non-spore-forming rod that grew by dissimilatory reduction of Se(IV) to Se(0). When the two isolates were cocultured, a complete reduction of Se(VI) to Se(0) was achieved. Both isolates are alkaliphiles and had optimal specific growth rates in the pH range of 8.5-10. Strain E1H had a salinity optimum at 60 g 1-1 NaCl, while strain MLS10 had optimal growth at lower salinities (24-60 g 1-1 NaCl). Both strains have limited abilities to grow with electron donors and acceptors other than those given above. Strain MLS10 demonstrated weak growth as a microaerophile and was also capable of fermentative growth on glucose, while strain E1H is a strict anaerobe. Comparative 16S rRNA gene sequence analysis placed the two isolates with other Bacillus spp. in the low G+C gram-positive group of bacteria.

  1. Electricity generation by anaerobic bacteria and anoxic sediments from hypersaline soda lakes

    USGS Publications Warehouse

    Miller, L.G.; Oremland, R.S.

    2008-01-01

    Anaerobic bacteria and anoxic sediments from soda lakes produced electricity in microbial fuel cells (MFCs). No electricity was generated in the absence of bacterial metabolism. Arsenate respiring bacteria isolated from moderately hypersaline Mono Lake (Bacillus selenitireducens), and salt-saturated Searles Lake, CA (strain SLAS-1) oxidized lactate using arsenate as the electron acceptor. However, these cultures grew equally well without added arsenate using the MFC anode as their electron acceptor, and in the process oxidized lactate more efficiently. The decrease in electricity generation by consumption of added alternative electron acceptors (i.e. arsenate) which competed with the anode for available electrons proved to be a useful indicator of microbial activity and hence life in the fuel cells. Shaken sediment slurries from these two lakes also generated electricity, with or without added lactate. Hydrogen added to sediment slurries was consumed but did not stimulate electricity production. Finally, electricity was generated in statically incubated "intact" sediment cores from these lakes. More power was produced in sediment from Mono Lake than from Searles Lake, however microbial fuel cells could detect low levels of metabolism operating under moderate and extreme conditions of salt stress. ?? 2008 US Government.

  2. Sublethal toxicity of chlorpyrifos to salmonid olfaction after hypersaline acclimation.

    PubMed

    Maryoung, Lindley A; Blunt, Brian; Tierney, Keith B; Schlenk, Daniel

    2015-04-01

    Salmonid habitats can be impacted by several environmental factors, such as salinization, which can also affect salmonid tolerance to anthropogenic stressors, such as pesticides. Previous studies have shown that hypersaline acclimation enhances the acute toxicity of certain organophosphate and carbamate pesticides to euryhaline fish; however, sublethal impacts have been far less studied. The current study aims to determine how hypersaline acclimation and exposure to the organophosphate chlorpyrifos (CPF) impact salmonid olfaction. Combined acclimation and exposure to CPF was shown to impact rainbow trout olfaction at the molecular, physiological, and behavioral levels. Concurrent exposure to hypersalinity and 0.5μg/L CPF upregulated four genes (chloride intracellular channel 4, G protein zgc:101761, calcium calmodulin dependent protein kinase II delta, and adrenergic alpha 2C receptor) that inhibit olfactory signal transduction. At the physiological level, hypersalinity and chlorpyrifos caused a decrease in sensory response to the amino acid l-serine and the bile salt taurocholic acid. Combined acclimation and exposure also negatively impacted behavior and reduced the avoidance of a predator cue (l-serine). Thus, acclimation to hypersaline conditions and exposure to environmentally relevant concentrations of chlorpyrifos caused an inhibition of olfactory signal transduction leading to a decreased response to odorants and impairment of olfactory mediated behaviors. PMID:25697678

  3. Hypersalinity drives physiological and morphological changes in Limia perugiae (Poeciliidae).

    PubMed

    Weaver, Pablo F; Tello, Oscar; Krieger, Jonathan; Marmolejo, Arlen; Weaver, Kathleen F; Garcia, Jerome V; Cruz, Alexander

    2016-01-01

    A fundamental question in biology is how an organism's morphology and physiology are shaped by its environment. Here, we evaluate the effects of a hypersaline environment on the morphology and physiology of a population of livebearing fish in the genus Limia (Poeciliidae). We sampled from two populations of Limia perugiae (one freshwater and one hypersaline) in the southwest Dominican Republic. We evaluated relative abundance of osmoregulatory proteins using western blot analyses and used a geometric morphometric approach to evaluate fine-scale changes to size and shape. Our data show that gill tissue isolated from hypersaline fish contained approximately two and a half times higher expression of Na(+)/K(+) ATPase proteins. We also show evidence for mitochondrial changes within the gills, with eight times more complex I and four times higher expression of ATP synthase within the gill tissue from the hypersaline population. The energetic consequences to Limia living in saline and hypersaline environments may be a driver for phenotypic diversity, reducing the overall body size and changing the relative size and shape of the head, as well as impeding the growth of secondary sex features among the males. PMID:27402966

  4. Bacterial Dormancy Is More Prevalent in Freshwater than Hypersaline Lakes

    PubMed Central

    Aanderud, Zachary T.; Vert, Joshua C.; Lennon, Jay T.; Magnusson, Tylan W.; Breakwell, Donald P.; Harker, Alan R.

    2016-01-01

    Bacteria employ a diverse array of strategies to survive under extreme environmental conditions but maintaining these adaptations comes at an energetic cost. If energy reserves drop too low, extremophiles may enter a dormant state to persist. We estimated bacterial dormancy and identified the environmental variables influencing our activity proxy in 10 hypersaline and freshwater lakes across the Western United States. Using ribosomal RNA:DNA ratios as an indicator for bacterial activity, we found that the proportion of the community exhibiting dormancy was 16% lower in hypersaline than freshwater lakes. Based on our indicator variable multiple regression results, saltier conditions in both freshwater and hypersaline lakes increased activity, suggesting that salinity was a robust environmental filter structuring bacterial activity in lake ecosystems. To a lesser degree, higher total phosphorus concentrations reduced dormancy in all lakes. Thus, even under extreme conditions, the competition for resources exerted pressure on activity. Within the compositionally distinct and less diverse hypersaline communities, abundant taxa were disproportionately active and localized in families Microbacteriaceae (Actinobacteria), Nitriliruptoraceae (Actinobacteria), and Rhodobacteraceae (Alphaproteobacteria). Our results are consistent with the view that hypersaline communities are able to capitalize on a seemingly more extreme, yet highly selective, set of conditions and finds that extremophiles may need dormancy less often to thrive and survive. PMID:27375575

  5. Hypersalinity drives physiological and morphological changes in Limia perugiae (Poeciliidae)

    PubMed Central

    Tello, Oscar; Krieger, Jonathan; Marmolejo, Arlen; Weaver, Kathleen F.; Garcia, Jerome V.; Cruz, Alexander

    2016-01-01

    ABSTRACT A fundamental question in biology is how an organism's morphology and physiology are shaped by its environment. Here, we evaluate the effects of a hypersaline environment on the morphology and physiology of a population of livebearing fish in the genus Limia (Poeciliidae). We sampled from two populations of Limia perugiae (one freshwater and one hypersaline) in the southwest Dominican Republic. We evaluated relative abundance of osmoregulatory proteins using western blot analyses and used a geometric morphometric approach to evaluate fine-scale changes to size and shape. Our data show that gill tissue isolated from hypersaline fish contained approximately two and a half times higher expression of Na+/K+ ATPase proteins. We also show evidence for mitochondrial changes within the gills, with eight times more complex I and four times higher expression of ATP synthase within the gill tissue from the hypersaline population. The energetic consequences to Limia living in saline and hypersaline environments may be a driver for phenotypic diversity, reducing the overall body size and changing the relative size and shape of the head, as well as impeding the growth of secondary sex features among the males. PMID:27402966

  6. Elevated concentrations of actinides in mono lake.

    PubMed

    Anderson, R F; Bacon, M P; Brewer, P G

    1982-04-30

    Tetravalent thorium, pentavalent protactinium, hexavalent uranium, and plutonium (oxidation state uncertain) are present in much higher concentrations in Mono Lake, a saline, alkaline lake in eastern central California, than in seawater. Low ratios of actinium to protactinium and of americium to plutonium indicate that the concentrations of trivalent actinides are not similarly enhanced. The elevated concentrations of the ordinarily very insoluble actinides are maintained in solution by natural ligands, which inhibit their chemical removal from the water column, rather than by an unusually large rate of supply. PMID:17735740

  7. Elevated concentrations of actinides in Mono Lake

    SciTech Connect

    Anderson, R.F.; Bacon, M.P.; Brewer, P.G.

    1982-04-30

    Tetravalent thorium, pentavalent protactinium, hexavalent uranium, and plutonium (oxidation state uncertain) are present in much higher concentrations in Mono Lake, a saline, alkaline lake in eastern central California, than in seawater. Low ratios of actinium to protactinium and of americium to plutonium indicate that the concentrations of trivalent actinides are not similarly enhanced. The elevated concentrations of the ordinarily very insoluble actinides are maintained in solution by natural ligands, which inhibit their chemical removal from the water column, rather than by an unusually large rate of supply.

  8. Spirochaeta Americana Sp. Nov., A new Haloalkaliphilic, Obligately Anaerobic Spirochete Isolated from Soda Mono Lake in California

    NASA Technical Reports Server (NTRS)

    Hoover, Richard B.; Pikuta, Elena V.; Bej, Asim K.; Marsic, Damien; Whitman, William B.; Tang, Jane; Krader, Paul; Six, N. Frank (Technical Monitor)

    2002-01-01

    A novel obligately anaerobic, mesophilic, haloalkaliphilic spirochete, strain ASpG1(sup T), was isolated from sediments of the alkaline, hypersaline Mono Lake in California, U.S.A. The Gram-negative cells are motile and spirochete-shaped with sizes of 0.2 - 0.22 X 8-15 microns. Growth was observed over the following ranges: temperature 10 C to 44 C; optimum +37 C; NaCl concentration 2 - 12 % (w/v); optimum NaCl3 % and pH 8 - 10.5; optimum pH 9.5. The novel isolate is strictly alkaliphilic, requires high concentrations of carbonate in the medium, and is capable of utilizing D-glucose, fructose, maltose, sucrose, starch, and D-mannitol. The main end products of glucose fermentation are: H2, acetate, ethanol, and formate. Strain ASpG(sup T) is resistant to kanamycin, and rifampin, but sensitive to chloramphenicol, gentamycin and tetracycline. The G+C content of its DNA is 58.5 mol%, genome size is 2.98 x l0(exp 9) Daltons, Tm of the genomic DNA is 68 +/- 2 C, and DNA-DNA hybridization with the most closely related species, Spirocheta alkalica Strain Z-7491(sup T), exhibited 48.7% homology. On the basis of its physiological and molecular properties, the isolate appears to be a novel species of the genus Spirochaeta; and the name Spirochaeta americana sp. nov., is proposed for the taxon (type strain ASpG1(sup T) = ATCC BAA-392(sup T) = DSMZ 14872(sup T)).

  9. How Long Is Mono Contagious?

    MedlinePlus

    ... Can I Help a Friend Who Cuts? How Long Is Mono Contagious? KidsHealth > For Teens > How Long Is Mono Contagious? Print A A A Text ... so lots of people are confused about how long it is contagious. Once someone gets mono, the ...

  10. Ophiuroids Discovered in the Middle Triassic Hypersaline Environment

    PubMed Central

    Salamon, Mariusz A.; Niedźwiedzki, Robert; Lach, Rafał; Brachaniec, Tomasz; Gorzelak, Przemysław

    2012-01-01

    Echinoderms have long been considered to be one of the animal phyla that is strictly marine. However, there is growing evidence that some recent species may live in either brackish or hypersaline environments. Surprisingly, discoveries of fossil echinoderms in non-(open)marine paleoenvironments are lacking. In Wojkowice Quarry (Southern Poland), sediments of lowermost part of the Middle Triassic are exposed. In limestone layer with cellular structures and pseudomorphs after gypsum, two dense accumulations of articulated ophiuroids (Aspiduriella similis (Eck)) were documented. The sediments with ophiuroids were formed in environment of increased salinity waters as suggested by paleontological, sedimentological, petrographical and geochemical data. Discovery of Triassic hypersaline ophiuroids invalidates the paleontological assumption that fossil echinoderms are indicators of fully marine conditions. Thus caution needs to be taken when using fossil echinoderms in paleoenvironmental reconstructions. PMID:23185442

  11. Eucaryotic Diversity in a Hypersaline Microbial Mat▿ †

    PubMed Central

    Feazel, Leah M.; Spear, John R.; Berger, Alicia B.; Harris, J. Kirk; Frank, Daniel N.; Ley, Ruth E.; Pace, Norman R.

    2008-01-01

    To determine the eucaryotic diversity of the hypersaline Guerrero Negro microbial mat, we amplified 18S rRNA genes from DNA extracted from this mat and constructed and analyzed clone libraries. The extent of eucaryotic diversity detected was remarkably low, only 15 species among 890 clones analyzed. Six eucaryotic kingdoms were represented, as well as a novel cluster of sequences. Nematode sequences dominated the clone libraries. PMID:17993566

  12. Methanogenesis in Big Soda Lake, Nevada: an Alkaline, Moderately Hypersaline Desert Lake

    PubMed Central

    Oremland, Ronald S.; Marsh, Lorraine; DesMarais, David J.

    1982-01-01

    Incubated sediment slurries from Big Soda Lake, Nevada, produced significant levels of CH4, and production was inhibited by 2-bromoethanesulfonic acid and by autoclaving. Methane production was stimulated by methanol, trimethylamine, and, to a lesser extent, methionine. Surprisingly, hydrogen, acetate, and formate amendments provided only slight or no stimulation of methanogenesis. Methane production by sediment slurries had a pH optimum of 9.7. A methanol-grown enrichment culture containing a small, epifluorescent coccus as the predominant organism was recovered from sediments. The enrichment grew best when FeS or autoclaved sediment particles were included in the media, had a pH optimum of 9.7, and produced 14CH4 from 14CH3OH. The methane formed by methanolgrown enrichment cultures was depleted in 13C by 72 to 77‰ relative to the methanol. PMID:16345952

  13. Controls on the pH of hyper-saline lakes - A lesson from the Dead Sea

    NASA Astrophysics Data System (ADS)

    Golan, Rotem; Gavrieli, Ittai; Ganor, Jiwchar; Lazar, Boaz

    2016-01-01

    The pH of aqueous environments is determined by the dominant buffer systems of the water, defined operationally as total alkalinity (TA). The major buffer systems in the modern ocean are carbonic and boric acids of which the species bicarbonate, carbonate and borate make up about 77%, 19% and 4% of the TA, respectively. During the course of seawater evaporation (e.g. lagoons) the residual brine loses considerable portion of the dissolved inorganic carbon (DIC) and carbonate alkalinity (CA) already at the early stages of evaporation. DIC and CA decrease due to massive precipitation of CaCO3, while total boron (TB) increases conservatively, turning borate to the dominant alkalinity species in marine derived brines. In the present work we assess the apparent dissociation constant value of boric acid (KB‧) in saline and hypersaline waters, using the Dead Sea (DS) as a case study. We explain the DS low pH (∼6.3) and the effect of the boric and carbonic acid pK‧-s on the behavior of the brine's buffer system, including the pH increase that results from brine dilution.

  14. Characteristics and turnover of exopolymeric substances in a hypersaline microbial mat.

    PubMed

    Braissant, Olivier; Decho, Alan W; Przekop, Kristen M; Gallagher, Kimberley L; Glunk, Christina; Dupraz, Christophe; Visscher, Pieter T

    2009-02-01

    The properties and microbial turnover of exopolymeric substances (EPS) were measured in a hypersaline nonlithifying microbial mat (Eleuthera, Bahamas) to investigate their potential role in calcium carbonate (CaCO(3)) precipitation. Depth profiles of EPS abundance and enzyme activities indicated that c. 80% of the EPS were turned over in the upper 15-20 mm. Oxic and anoxic mat homogenates amended with low-molecular-weight (LMW) organic carbon, sugar monomers, and different types of EPS revealed rapid consumption of all substrates. When comparing the consumption of EPS with that of other substrates, only marginally longer lag times and lower rates were observed. EPS (5-8%) were readily consumed during the conversion of labile to refractory EPS. This coincided with a decrease in glucosidase activity and a decrease in the number of acidic functional groups on the EPS. Approximately half of the calcium bound to the EPS remained after 10 dialyses steps. This tightly bound calcium was readily available to precipitate as CaCO(3). We present a conceptual model in which LMW organic carbon complexed with the tightly bound calcium is released upon enzyme activity. This increases alkalinity and creates binding sites for carbonate and allows CaCO(3) to precipitate. Therefore, this model explains interactions between EPS and CaCO(3) precipitation, and underscores the critical role of aerobic and anaerobic microorganisms in early diagenesis and lithification processes. PMID:19049495

  15. Ancient Life at the Extremes: Molecular Fossils and Paleoenvironmental Contexts of a Neoproterozoic Hypersaline Setting

    NASA Astrophysics Data System (ADS)

    Schinteie, R.; Brocks, J. J.

    2011-12-01

    We present the first molecular investigation of the biotic composition and biogeochemistry of an evaporitic, hypersaline environment from the Neoproterozoic (~800 Ma). Through detailed analyses of both sedimentary textures and their lipid biomarkers, we provide the oldest evidence of organisms that could exist at extremely saline conditions. Such research is timely, since the discovery of evaporite deposits on Mars highlights the need to understand their capacities as biological archives. Samples for this study were derived from evaporitic sediments of the Neoproterozoic Bitter Springs Formation, Amadeus Basin, central Australia. Due to the broad shallow nature of the basin and a tenuous connection with the ocean, the water was characterized by elevated salinity levels during that time. As a result, thick (100 m to >2000 m) evaporite units were deposited. All samples for this study were derived from drill cores held at Geoscience Australia (Canberra) and at the Northern Territory Geological Survey at Alice Springs. We extracted biomarkers from evaporitic sediments composed of dolomite, anhydrite and/or halite. The dolomite layers commonly assume the shape of microbial mat-like formations that exhibit roll-up structures and tearing. Framboidal pyrite was commonly associated with the dolomite and together with other textural and stable isotopic data provide the oldest putative evidence for biologically-induced dolomite precipitation. Full scan gas chromatography-mass spectrometry (GCMS) of the saturate fractions of these evaporites revealed high ratios of mono-and dimethylalkanes relative to n-alkanes. Such a pattern is typical of Precambrian and Cambrian samples. These molecules, together with elevated relative concentrations of n-C17, provide evidence of a photoautotrophic community - especially cyanobacteria. A further outstanding characteristic of these samples are the presence of several pseudohomologous series of both regular (to C25) and irregular (to C40

  16. MAGNESIUM MONO POTASSIUM PHOSPHATE GROUT FOR P-REACTOR VESSEL IN-SITU DECOMISSIONING

    SciTech Connect

    Langton, C.; Stefanko, D.

    2011-01-05

    The objective of this report is to document laboratory testing of magnesium mono potassium phosphate grouts for P-Reactor vessel in-situ decommissioning. Magnesium mono potassium phosphate cement-based grout was identified as candidate material for filling (physically stabilizing) the 105-P Reactor vessel (RV) because it is less alkaline than portland cement-based grout (pH of about 12.4). A less alkaline material ({<=} 10.5) was desired to address a potential materials compatibility issue caused by corrosion of aluminum metal in highly alkaline environments such as that encountered in portland cement grouts. Information concerning access points into the P-Reactor vessel and amount of aluminum metal in the vessel is provided elsewhere. Fresh and cured properties were measured for: (1) commercially blended magnesium mono potassium phosphate packaged grouts, (2) commercially available binders blended with inert fillers at SRNL, (3) grouts prepared from technical grade MgO and KH{sub 2}PO{sub 4} and inert fillers (quartz sands, Class F fly ash), and (4) Ceramicrete{reg_sign} magnesium mono potassium phosphate-based grouts prepared at Argonne National Laboratory. Boric acid was evaluated as a set retarder in the magnesium mono potassium phosphate mixes.

  17. Picophytoplankton predominance in hypersaline lakes (Transylvanian Basin, Romania).

    PubMed

    Somogyi, Boglárka; Vörös, Lajos; Pálffy, Károly; Székely, Gyöngyi; Bartha, Csaba; Keresztes, Zsolt Gyula

    2014-11-01

    The occurrence and importance of photoautotrophic picoplankton (PPP, cells with a diameter <2 μm) was studied along a trophic and salinity gradient in hypersaline lakes of the Transylvanian Basin (Romania). The studied lakes were found to be rich in PPP, with abundances (maximum 7.6 × 10(6) cells mL(-1)) higher than in freshwater and marine environments of similar trophic conditions. The contribution of PPP to the total phytoplankton biovolume did not decrease with increasing trophic state as it was generally found in other aquatic environments. Regardless of the trophic conditions, the contribution of PPP could reach 90-100 % in these hypersaline lakes. We hypothesized that the PPP predominance might be the result of the low grazing pressure, since heterotrophic nanoflagellates (the main grazers of PPP) were absent in the studied samples. There were significant differences in community composition among the lakes along the salinity gradient. CyPPP predominated in less saline waters (mainly below 5 %), while EuPPP were present along the entire salinity range (up to 18.7 %), dominating the phytoplankton between 3 and 13 % salinity. Above 13 % salinity, the phytoplankton was composed mainly of Dunaliella species. PMID:25116056

  18. Lipid Biomarkers for a Hypersaline Microbial Mat Community

    NASA Technical Reports Server (NTRS)

    Jahnke, Linda L.; Embaye, Tsege; Turk, Kendra A.

    2003-01-01

    The use of lipid biomarkers and their carbon isotopic compositions are valuable tools for establishing links to ancient microbial ecosystems. As witnessed by the stromatolite record, benthic microbial mats grew in shallow water lagoonal environments where microorganisms had virtually no competition apart from the harsh conditions of hypersalinity, desiccation and intense light. Today, the modern counterparts of these microbial ecosystems find appropriate niches in only a few places where extremes eliminate eukaryotic grazers. Answers to many outstanding questions about the evolution of microorganisms and their environments on early Earth are best answered through study of these extant analogs. Lipids associated with various groups of bacteria can be valuable biomarkers for identification of specific groups of microorganisms both in ancient organic-rich sedimentary rocks (geolipids) and contemporary microbial communities (membrane lipids). Use of compound specific isotope analysis adds additional refinement to the identification of biomarker source, so that it is possible to take advantage of the 3C-depletions associated with various functional groups of organisms (i.e. autotrophs, heterotrophs, methanotrophs, methanogens) responsible for the cycling of carbon within a microbial community. Our recent work has focused on a set of hypersaline evaporation ponds at Guerrero Negro, Baja California Sur, Mexico which support the abundant growth of Microcoleus-dominated microbial mats. Specific biomarkers for diatoms, cyanobacteria, archaea, green nonsulfur (GNS), sulfate reducing, and methanotrophic bacteria have been identified. Analyses of the ester-bound fatty acids indicate a highly diverse microbial community, dominated by photosynthetic organisms at the surface.

  19. Community Composition of a Hypersaline Endoevaporitic Microbial Mat

    PubMed Central

    Sørensen, Ketil Bernt; Canfield, Donald E.; Teske, Andreas P.; Oren, Aharon

    2005-01-01

    A hypersaline, endoevaporitic microbial community in Eilat, Israel, was studied by microscopy and by PCR amplification of genes for 16S rRNA from different layers. In terms of biomass, the oxygenic layers of the community were dominated by Cyanobacteria of the Halothece, Spirulina, and Phormidium types, but cell counts (based on 4′,6′-diamidino-2-phenylindole staining) and molecular surveys (clone libraries of PCR-amplified genes for 16S rRNA) showed that oxygenic phototrophs were outnumbered by the other constituents of the community, including chemotrophs and anoxygenic phototrophs. Bacterial clone libraries were dominated by phylotypes affiliated with the Bacteroidetes group and both photo- and chemotrophic groups of α-proteobacteria. Green filaments related to the Chloroflexi were less abundant than reported from hypersaline microbial mats growing at lower salinities and were only detected in the deepest part of the anoxygenic phototrophic zone. Also detected were nonphototrophic γ- and δ-proteobacteria, Planctomycetes, the TM6 group, Firmicutes, and Spirochetes. Several of the phylotypes showed a distinct vertical distribution in the crust, suggesting specific adaptations to the presence or absence of oxygen and light. Archaea were less abundant than Bacteria, their diversity was lower, and the community was less stratified. Detected archaeal groups included organisms affiliated with the Methanosarcinales, the Halobacteriales, and uncultured groups of Euryarchaeota. PMID:16269778

  20. Anaerobic oxidation of methane in hypersaline cold seep sediments.

    PubMed

    Maignien, Loïs; Parkes, R John; Cragg, Barry; Niemann, Helge; Knittel, Katrin; Coulon, Stephanie; Akhmetzhanov, Andrey; Boon, Nico

    2013-01-01

    Life in hypersaline environments is typically limited by bioenergetic constraints. Microbial activity at the thermodynamic edge, such as the anaerobic oxidation of methane (AOM) coupled to sulphate reduction (SR), is thus unlikely to thrive in these environments. In this study, carbon and sulphur cycling was investigated in the extremely hypersaline cold seep sediments of Mercator mud volcano. AOM activity was partially inhibited but still present at salinity levels of 292 g L(-1) (c. eightfold sea water concentration) with rates of 2.3 nmol cm(-3) day(-1) and was even detectable under saturated conditions. Methane and evaporite-derived sulphate comigrated in the ascending geofluids, which, in combination with a partial activity inhibition, resulted in AOM activity being spread over unusually wide depth intervals. Up to 79% of total cells in the AOM zone were identified by fluorescence in situ hybridization (FISH) as anaerobic methanotrophs of the ANME-1. Most ANME-1 cells formed monospecific chains without any attached partner. At all sites, AOM activity co-occurred with SR activity and sometimes significantly exceeded it. Possible causes of these unexpected results are discussed. This study demonstrates that in spite of a very low energy yield of AOM, microorganisms carrying this reaction can thrive in salinity up to halite saturation. PMID:22882187

  1. Mono Lake Analog Mars Sample Return Expedition for AMASE

    NASA Technical Reports Server (NTRS)

    Conrad, P. G.; Steele, A.; Younse, P.; DiCicco, M.; Morgan, A. R.; Backes, P.; Eigenbrode, J. E.; Marquardt, D.; Amundsen, H. E. F.

    2011-01-01

    We explored the performance of one robotic prototype for sample acquisition and caching of martian materials that has been developed at the Jet Propulsion Laboratory for potential use in the proposed MAX-C Mars Sample Return architecture in an environment, rich in chemical diversity with a variety of mineralogical textures. Mono Lake State Tufa Reserve in Mono County, CA possesses a variety of minerals including a variety of evaporites, volcanic glass and lava, and sand and mudstones. The lake itself is an interesting chemical system: the water is highly alkaline (pH is approximately 10) and contains concentrations of Cl, K, B, with lesser amounts of S Ca Mg, F, As, Li, I and Wand generally enriched HREEs. There are also traces of radioactive elements U, Th, Pl.

  2. Methanogenesis in hypersaline environments -Analogs for Ancient Mars?

    NASA Astrophysics Data System (ADS)

    Bebout, Brad; Chanton, Jeff; Kelley, Cheryl; Tazaz, Amanda; Poole, Jennifer; García Maldonado, José Q.; López Cortés, Alejandro

    The recent findings of evidence of large bodies of hypersaline water which existed in the past on Mars have underscored the need to investigate those environments for evidence of past, as well as extant, life. Methane, a key biomarker gas, has been reported in the atmosphere of Mars, and is known to be produced by microbial mats which are present in most hypersaline environments on Earth. Modern microbial mat communities are thought to be extant analogues of communities which were present early in Earth's geologic history, when environmental condition on Earth and Mars were similar. Because methane may be an indication of life (biogenic methane) but might also be a consequence of geologic activity (abiotic methane) and/or the thermal alteration of ancient organic matter (thermogenic methane), the stable isotopic composition of methane (both carbon and hydrogen) will be a key criterion for determining whether or not the methane on Mars is biologically produced, and if so, how recently (i.e., biogenic vs. thermogenic methane). The goals of our study are: a) to document the range of the stable isotopic composition of methane (both carbon and hydrogen) in hypersaline environments, and b) to understand the role of biology in generating that stable isotopic composition. Our results will help provide a framework for the interpretation of methane stable isotopic data from Mars. We have measured high concentrations of methane in bubbles of gas present in the Guerrero Negro hypersaline ecosystem, Baja California Mexico and in salt ponds on the San Francisco Bay. These bubbles are present both in sediments underlying microbial mats (including one site where methane constitutes nearly 40% by volume of the bubbles), as well as in areas not colonized by microbial mats; layers of evaporitic minerals in some areas trap gas containing high concentrations of methane. The carbon isotopic (δ 13 C) composition of the methane in collected bubbles exhibited an extremely wide range of

  3. Impacts of hypersaline acclimation on the acute toxicity of the organophosphate chlorpyrifos to salmonids.

    PubMed

    Maryoung, Lindley A; Lavado, Ramon; Schlenk, Daniel

    2014-07-01

    Acclimation to hypersaline conditions enhances the acute toxicity of certain thioether organophosphate and carbamate pesticides in some species of euryhaline fish. As the organophosphate chlorpyrifos is commonly detected in salmonid waterways, the impacts of hypersaline conditions on its toxicity were examined. In contrast to other previously examined pesticides, time to death by chlorpyrifos was more rapid in freshwater than in hypersaline water (16ppth). The median lethal time (LT50) after 100μg/L chlorpyrifos exposure was 49h (95% CI: 31-78) and 120h (95% CI: 89-162) for rainbow trout (Oncorhynchus mykiss) in freshwater and those acclimated to hypersaline conditions, respectively. Previous studies with hypersaline acclimated fish indicated induction of xenobiotic metabolizing enzymes that may detoxify chlorpyrifos. In the current study, chlorpyrifos metabolism was unaltered in liver and gill microsomes of freshwater and hypersaline acclimated fish. Acetylcholinesterase inhibition in brain and bioavailability of chlorpyrifos from the aqueous exposure media were also unchanged. In contrast, mRNA expression of neurological targets: calcium calmodulin dependent protein kinase II delta, chloride intracellular channel 4, and G protein alpha i1 were upregulated in saltwater acclimated fish, consistent with diminished neuronal signaling which may protect animals from cholinergic overload associated with acetylcholinesterase inhibition. These results indicate targets other than acetylcholinesterase may contribute to the altered toxicity of chlorpyrifos in salmonids under hypersaline conditions. PMID:24799192

  4. The microbial arsenic cycle in Mono Lake, California.

    PubMed

    Oremland, Ronald S; Stolz, John F; Hollibaugh, James T

    2004-04-01

    Significant concentrations of dissolved inorganic arsenic can be found in the waters of a number of lakes located in the western USA and in other water bodies around the world. These lakes are often situated in arid, volcanic terrain. The highest concentrations of arsenic occur in hypersaline, closed basin soda lakes and their remnant brines. Although arsenic is a well-known toxicant to eukaryotes and prokaryotes alike, some prokaryotes have evolved biochemical mechanisms to exploit arsenic oxyanions (i.e., arsenate and arsenite); they can use them either as an electron acceptor for anaerobic respiration (arsenate), or as an electron donor (arsenite) to support chemoautotrophic fixation of CO(2) into cell carbon. Unlike in freshwater or marine ecosystems, these processes may assume quantitative significance with respect to the carbon cycle in arsenic-rich soda lakes. For the past several years our research has focused on the occurrence and biogeochemical manifestations of these processes in Mono Lake, a particularly arsenic-rich environment. Herein we review some of our findings concerning the biogeochemical arsenic cycle in this lake, with the hope that it may broaden the understanding of the influence of microorganisms upon the speciation of arsenic in more common, less "extreme" environments, such as drinking water aquifers. PMID:19712427

  5. Methanosalsum natronophilum sp. nov., and Methanocalculus alkaliphilus sp. nov., haloalkaliphilic methanogens from hypersaline soda lakes.

    PubMed

    Sorokin, Dimitry Y; Abbas, Ben; Merkel, Alexander Y; Rijpstra, W Irene C; Damsté, Jaap S Sinninghe; Sukhacheva, Marina V; van Loosdrecht, Mark C M

    2015-10-01

    Two groups of haloalkaliphilic methanogenic archaea were dominating in enrichments from hypersaline soda lake sediments at pH 10. At moderate salt concentrations with formate or H2 as electron donor, methanogens belonging to the genus Methanocalculus were enriched, while at high salt concentrations with methylated substrates, a group related to Methanosalsum zhilinae was dominating. For both groups, several pure cultures were obtained including the type strains AMF2T for the Methanocalculus group and AME2T for the Methanosalsum group. The Methanocalculus group is characterized by lithoheterotrophic growth with either formate (preferable substrate) or H2 at moderate salinity up to 1.5-2 M total Na+ and obligate alkaliphilic growth with an optimum at pH 9.5. According to phylogenetic analysis, the group also includes closely related strains isolated previously from the low-salt alkaline Lonar Lake. The novel Methanosalsum group is characterized by high salt tolerance (up to 3.5 M total Na+) and obligate alkaliphilic growth with an optimum at pH 9.5. It has a typical methylotrophic substrate profile, utilizing methanol, methylamines and dimethyl sulfide (at low concentrations) as methanogenic substrates. On the basis of physiological and phylogenetic data, it is proposed that the two groups of soda lake methanogenic isolates are assigned into two novel species, Methanocalculus alkaliphilus sp. nov. (type strain AMF2T = DSM 24457T = UNIQEM U859T) and Methanosalsum natronophilum sp. nov. (type strain AME2T = DSM 24634T = NBRC 110091T). PMID:26228570

  6. New Abundant Microbial Groups in Aquatic Hypersaline Environments

    PubMed Central

    Ghai, Rohit; Pašić, Lejla; Fernández, Ana Beatriz; Martin-Cuadrado, Ana-Belen; Mizuno, Carolina Megumi; McMahon, Katherine D.; Papke, R. Thane; Stepanauskas, Ramunas; Rodriguez-Brito, Beltran; Rohwer, Forest; Sánchez-Porro, Cristina; Ventosa, Antonio; Rodríguez-Valera, Francisco

    2011-01-01

    We describe the microbiota of two hypersaline saltern ponds, one of intermediate salinity (19%) and a NaCl saturated crystallizer pond (37%) using pyrosequencing. The analyses of these metagenomes (nearly 784 Mb) reaffirmed the vast dominance of Haloquadratum walsbyi but also revealed novel, abundant and previously unsuspected microbial groups. We describe for the first time, a group of low GC Actinobacteria, related to freshwater Actinobacteria, abundant in low and intermediate salinities. Metagenomic assembly revealed three new abundant microbes: a low-GC euryarchaeon with the lowest GC content described for any euryarchaeon, a high-GC euryarchaeon and a gammaproteobacterium related to Alkalilimnicola and Nitrococcus. Multiple displacement amplification and sequencing of the genome from a single archaeal cell of the new low GC euryarchaeon suggest a photoheterotrophic and polysaccharide-degrading lifestyle and its relatedness to the recently described lineage of Nanohaloarchaea. These discoveries reveal the combined power of an unbiased metagenomic and single cell genomic approach. PMID:22355652

  7. MILLIMETER-SCALE GENETIC GRADIENTS AND COMMUNITY-LEVEL MOLECULAR CONVERGENCE IN A HYPERSALINE MICROBIAL MAT

    SciTech Connect

    Fenner, Marsha W; Kunin, Victor; Raes, Jeroen; Harris, J. Kirk; Spear, John R.; Walker, Jeffrey J.; Ivanova, Natalia; Mering, Christian von; Bebout, Brad M.; Pace, Norman R.; Bork, Peer; Hugenholtz, Philip

    2008-04-30

    To investigate the extent of genetic stratification in structured microbial communities, we compared the metagenomes of 10 successive layers of a phylogenetically complex hypersaline mat from Guerrero Negro, Mexico. We found pronounced millimeter-scale genetic gradients that are consistent with the physicochemical profile of the mat. Despite these gradients, all layers displayed near identical and acid-shifted isoelectric point profiles due to a molecular convergence of amino acid usage indicating that hypersalinity enforces an overriding selective pressure on the mat community.

  8. ALP (Alkaline Phosphatase) Test

    MedlinePlus

    ... known as: ALK PHOS; Alkp Formal name: Alkaline Phosphatase Related tests: AST ; ALT ; GGT ; Bilirubin ; Liver Panel ; Bone Markers ; Alkaline Phosphatase Isoenzymes; Bone Specific ALP All content on Lab ...

  9. Lipid Biomarkers for a Hypersaline Microbial Mat Community

    NASA Technical Reports Server (NTRS)

    Jahnke, Linda; Orphan, Victoria; Embaye, Tsegereda; Turk, Kendra; Kubo, Mike; Summons, Roger

    2004-01-01

    The use of lipid biomarkers and their carbon isotopic compositions are valuable tools for establishing links to ancient microbial ecosystems. Various lipids associated with specific microbial groups can serve as biomarkers for establishing organism source and function in contemporary microbial ecosystems (membrane lipids), and by analogy, potential relevance to ancient organic-rich sedimentary rocks (geolipids). As witnessed by the stromatolite record, benthic microbial mats grew in shallow water lagoonal environments. Our recent work has focused on lipid biomarker analysis of a potential analogue for such ancient mats growing in a set of hypersaline evaporation ponds at Guerrero Negro, Baja California Sur, Mexico. The aerobic, surface layer of this mat (0 to 1 mm) contained a variety of ester-bound fatty acids (FA) representing a diverse bacterial population including cyanobacteria, sulphate reducers (SRB) and heterotrophs. Biomarkers for microeukaryotes detected in this layer included sterols, C-20 polyunsaturated FA and a highly branched isoprenoid, diagnostic for diatoms. Cyanobacteria were also indicated by the presence of a diagnostic set of mid-chain methylalkanes. C-28, to C-34 wax esters (WXE) present in relatively small amounts in the upper 3 mm of the mat are considered biomarkers for green non-sulphur bacteria. Ether-bound isoprenoids were also identified although in considerably lower abundance than ester-bound FA (approx. 1:l0). These complex ether lipids included archatol, hydroxyarchaeol and a C-40 tetraether, all in small amounts. After ether cleavage with boron tribromide, the major recovered isoprenyl was a C-30:1. This C(sub 30;1) yelded squalane after hydrogenation, a known geobiomarker for hypersaline environments in ancient oils and sediments. In this mat, it represents the dominant Archaeal population. The carbon isotopic composition of biomarker lipids were generally depleted relative to the bulk organic material (delta C-13 TOC -10%). Most

  10. Resilience of estuarine phytoplankton and their temporal variability along salinity gradients during drought and hypersalinity

    NASA Astrophysics Data System (ADS)

    Nche-Fambo, F. A.; Scharler, U. M.; Tirok, K.

    2015-06-01

    In South African estuaries, there is no knowledge on the resilience and variability in phytoplankton communities under conditions of hypersalinity, extended droughts and reverse salinity gradients. Phytoplankton composition, abundance and biomass vary with changes in environmental variables and taxa richness declines specifically under hypersaline conditions. This research thus investigated the phytoplankton community composition, its resilience and variability under highly variable and extreme environmental conditions in an estuarine lake system (Lake St. Lucia, South Africa) over one year. The lake system was characterised by a reverse salinity gradient with hypersalinity furthest from the estuarine inlet during the study period. During this study, 78 taxa were recorded: 56 diatoms, eight green algae, one cryptophyte, seven cyanobacteria and six dinoflagellates. Taxon variability and resilience depended on their ability to tolerate high salinities. Consequently, the phytoplankton communities as well as total abundance and biomass differed along the salinity gradient and over time with salinity as the main determinant. Cyanobacteria were dominant in hypersaline conditions, dinoflagellates in marine-brackish salinities, green algae and cryptophytes in lower salinities (brackish) and diatoms were abundant in marine-brackish salinities but survived in hypersaline conditions. Total abundance and biomass ranged from 3.66 × 103 to 1.11 × 109 Cells/L and 1.21 × 106 to 1.46 × 1010 pgC/L respectively, with the highest values observed under hypersaline conditions. Therefore, even under highly variable, extreme environmental conditions and hypersalinity the phytoplankton community as a whole was resilient enough to maintain a relatively high biomass throughout the study period. The resilience of few dominant taxa, such as Cyanothece, Spirulina, Protoperidinium and Nitzschia and the dominance of other common genera such as Chlamydomonas, Chroomonas, Navicula, Gyrosigma

  11. Effect of hypersaline cooling canals on aquifer salinization

    NASA Astrophysics Data System (ADS)

    Hughes, Joseph D.; Langevin, Christian D.; Brakefield-Goswami, Linzy

    2010-02-01

    The combined effect of salinity and temperature on density-driven convection was evaluated in this study for a large (28 km2) cooling canal system (CCS) at a thermoelectric power plant in south Florida, USA. A two-dimensional cross-section model was used to evaluate the effects of hydraulic heterogeneities, cooling canal salinity, heat transport, and cooling canal geometry on aquifer salinization and movement of the freshwater/saltwater interface. Four different hydraulic conductivity configurations, with values ranging over several orders of magnitude, were evaluated with the model. For all of the conditions evaluated, aquifer salinization was initiated by the formation of dense, hypersaline fingers that descended downward to the bottom of the 30-m thick aquifer. Saline fingers reached the aquifer bottom in times ranging from a few days to approximately 5 years for the lowest hydraulic conductivity case. Aquifer salinization continued after saline fingers reached the aquifer bottom and coalesced by lateral movement away from the site. Model results showed that aquifer salinization was most sensitive to aquifer heterogeneity, but was also sensitive to CCS salinity, temperature, and configuration.

  12. Characterization of eukaryotic microbial diversity in hypersaline Lake Tyrrell, Australia

    PubMed Central

    Heidelberg, Karla B.; Nelson, William C.; Holm, Johanna B.; Eisenkolb, Nadine; Andrade, Karen; Emerson, Joanne B.

    2013-01-01

    This study describes the community structure of the microbial eukaryotic community from hypersaline Lake Tyrrell, Australia, using near full length 18S rRNA sequences. Water samples were taken in both summer and winter over a 4-year period. The extent of eukaryotic diversity detected was low, with only 35 unique phylotypes using a 97% sequence similarity threshold. The water samples were dominated (91%) by a novel cluster of the Alveolate, Apicomplexa Colpodella spp., most closely related to C. edax. The Chlorophyte, Dunaliella spp. accounted for less than 35% of water column samples. However, the eukaryotic community entrained in a salt crust sample was vastly different and was dominated (83%) by the Dunaliella spp. The patterns described here represent the first observation of microbial eukaryotic dynamics in this system and provide a multiyear comparison of community composition by season. The lack of expected seasonal distribution in eukaryotic communities paired with abundant nanoflagellates suggests that grazing may significantly structure microbial eukaryotic communities in this system. PMID:23717306

  13. Microbial Biomass and Activity Distribution in an Anoxic, Hypersaline Basin

    PubMed Central

    LaRock, Paul A.; Lauer, Ray D.; Schwarz, John R.; Watanabe, Kathleen K.; Wiesenburg, Denis A.

    1979-01-01

    The Orca Basin is a hypersaline depression in the northern Gulf of Mexico with anoxic conditions observed in the lower 200 m of the water column. Measurements of adenosine 5′-triphosphate, heterotrophic potential, and uridine uptake made above and across the interface into the anoxic zone revealed the presence of an active microbial population approximately 100 m above the interface. Biomass and activity decreased at and just below the interface but increased near the bottom, consistent with similar observations made in the Cariaco Trench. The maximum adenosine 5′-triphosphate concentration above the interface of 5.9 ng/liter (2,173 m) is about eight times greater than the value found in oxygenated waters of corresponding depth in the absence of an anoxic zone. The maximum adenosine 5′-triphosphate concentration in the anoxic zone is approximately 15 times greater than that found in oxygenated water of similar depth, suggesting anoxia will support the development of a larger bacterial population. Our findings suggest that autotrophic bacteria may be the dominant physiological group in the region just above the interface. PMID:16345355

  14. Prokaryotic diversity in a Tunisian hypersaline lake, Chott El Jerid.

    PubMed

    Abdallah, Manel Ben; Karray, Fatma; Mhiri, Najla; Mei, Nan; Quéméneur, Marianne; Cayol, Jean-Luc; Erauso, Gaël; Tholozan, Jean-Luc; Alazard, Didier; Sayadi, Sami

    2016-03-01

    Prokaryotic diversity was investigated in a Tunisian salt lake, Chott El Jerid, by quantitative real-time PCR, denaturing gradient gel electrophoresis (DGGE) fingerprinting methods targeting the 16S rRNA gene and culture-dependent methods. Two different samples S1-10 and S2-10 were taken from under the salt crust of Chott El Jerid in the dry season. DGGE analysis revealed that bacterial sequences were related to Firmicutes, Proteobacteria, unclassified bacteria, and Deinococcus-Thermus phyla. Anaerobic fermentative and sulfate-reducing bacteria were also detected in this ecosystem. Within the domain archaea, all sequences were affiliated to Euryarchaeota phylum. Quantitative real-time PCR showed that 16S rRNA gene copy numbers of bacteria was 5 × 10(6) DNA copies g(-1) whereas archaea varied between 5 × 10(5) and 10(6) DNA copies g(-1) in these samples. Eight anaerobic halophilic fermentative bacterial strains were isolated and affiliated with the species Halanaerobium alcaliphilum, Halanaerobium saccharolyticum, and Sporohalobacter salinus. These data showed an abundant and diverse microbial community detected in the hypersaline thalassohaline environment of Chott El Jerid. PMID:26724953

  15. Assembly-Driven Community Genomics of a Hypersaline Microbial Ecosystem

    PubMed Central

    Podell, Sheila; Ugalde, Juan A.; Narasingarao, Priya; Banfield, Jillian F.; Heidelberg, Karla B.; Allen, Eric E.

    2013-01-01

    Microbial populations inhabiting a natural hypersaline lake ecosystem in Lake Tyrrell, Victoria, Australia, have been characterized using deep metagenomic sampling, iterative de novo assembly, and multidimensional phylogenetic binning. Composite genomes representing habitat-specific microbial populations were reconstructed for eleven different archaea and one bacterium, comprising between 0.6 and 14.1% of the planktonic community. Eight of the eleven archaeal genomes were from microbial species without previously cultured representatives. These new genomes provide habitat-specific reference sequences enabling detailed, lineage-specific compartmentalization of predicted functional capabilities and cellular properties associated with both dominant and less abundant community members, including organisms previously known only by their 16S rRNA sequences. Together, these data provide a comprehensive, culture-independent genomic blueprint for ecosystem-wide analysis of protein functions, population structure, and lifestyles of co-existing, co-evolving microbial groups within the same natural habitat. The “assembly-driven” community genomic approach demonstrated in this study advances our ability to push beyond single gene investigations, and promotes genome-scale reconstructions as a tangible goal in the quest to define the metabolic, ecological, and evolutionary dynamics that underpin environmental microbial diversity. PMID:23637883

  16. Microbial biomass and activity distribution in an anoxic, hypersaline basin.

    PubMed

    Larock, P A; Lauer, R D; Schwarz, J R; Watanabe, K K; Wiesenburg, D A

    1979-03-01

    The Orca Basin is a hypersaline depression in the northern Gulf of Mexico with anoxic conditions observed in the lower 200 m of the water column. Measurements of adenosine 5'-triphosphate, heterotrophic potential, and uridine uptake made above and across the interface into the anoxic zone revealed the presence of an active microbial population approximately 100 m above the interface. Biomass and activity decreased at and just below the interface but increased near the bottom, consistent with similar observations made in the Cariaco Trench. The maximum adenosine 5'-triphosphate concentration above the interface of 5.9 ng/liter (2,173 m) is about eight times greater than the value found in oxygenated waters of corresponding depth in the absence of an anoxic zone. The maximum adenosine 5'-triphosphate concentration in the anoxic zone is approximately 15 times greater than that found in oxygenated water of similar depth, suggesting anoxia will support the development of a larger bacterial population. Our findings suggest that autotrophic bacteria may be the dominant physiological group in the region just above the interface. PMID:16345355

  17. Alkaline Band Formation in Chara corallina

    PubMed Central

    Lucas, William J.

    1979-01-01

    The nature of the transport system responsible for the establishment of alkaline bands on cells of Chara corallina was investigated. The transport process was found to be insensitive to external pH, provided the value was above a certain threshold. At this threshold (pH 5.1 to 4.8) the transport process was inactivated. Transport function could be recovered by raising the pH value of the external solution. The fastest rate of recovery was always obtained in the presence of exogenous HCO3−. Experiments in which plasmalemma integrity was modified using 10 millimolar K+ treatment were also performed. Alkaline band transport was significantly reduced in the presence of 10 millimolar K+, but the system did not recover, following return to 0.2 millimolar K+ solutions, until the transport site was reexposed to exogenous HCO3−. The influence of presence and absence of various cations on both alkaline band transport and total H14CO3− assimilation was examined. No specific cation requirement (mono- or divalent) was found for either process, except the previously established role of Ca2+ at the HCO3− transport site. The alkaline band transport process exhibited a general requirement for cations. This transport system could be partially or completely stalled in low cation solutions, or glass-distilled water, respectively. The results indicate that no cationic flux occurs across the plasmalemma in direct association with either the alkaline band or HCO3− transport systems. It is felt that the present results offer support for the hypothesis that an OH− efflux transport system (rather than a H+ influx system) is responsible for alkaline band development in C. corallina. The results support the hypothesis that OH− efflux is an electrogenic process. This OH− transport system also appears to contain two allosteric effector sites, involving an acidic group and a HCO3− ion. PMID:16660706

  18. Mechanisms of fenthion activation in rainbow trout (Oncorhynchus mykiss) acclimated to hypersaline environments

    PubMed Central

    Lavado, Ramon; Rimoldi, John M.; Schlenk, Daniel

    2010-01-01

    Previous studies in rainbow trout have shown that acclimation to hypersaline environments enhances the toxicity to thioether organophosphate and carbamate pesticides. In order to determine the role of biotransformation in this process, the metabolism of the thioether organophosphate biocide, fenthion was evaluated in microsomes from gills, liver and olfactory tissues in rainbow trout (Oncorhynchus mykiss) acclimated to freshwater and 17‰ salinity. Hypersalinity acclimation increased the formation of fenoxon and fenoxon sulfoxide from fenthion in liver microsomes from rainbow trout, but not in gills or in olfactory tissues. NADPH-dependent and independent hydrolysis was observed in all tissues, but only NADPH-dependent fenthion cleavage was differentially modulated by hypersalinity in liver (inhibited) and gills (induced). Enantiomers of fenthion sulfoxide (65% and 35% R- and S-fenthion sulfoxide, respectively) were formed in liver and gills. The predominant pathway of fenthion activation in freshwater appears to be initiated through initial formation of fenoxon which may be subsequently converted to the most toxic metabolite fenoxon R-sulfoxide. However, in hypersaline conditions both fenoxon and fenthion sulfoxide formation may precede fenoxon sulfoxide formation. Stereochemical evaluation of sulfoxide formation, cytochrome P450 inhibition studies with ketoconazole and immunoblots indicated that CYP3A27 was primarily involved in the enhancement of fenthion activation in hypersaline-acclimated fish with limited contribution of FMO to initial sulfoxidation. PMID:19111563

  19. Mechanisms of fenthion activation in rainbow trout (Oncorhynchus mykiss) acclimated to hypersaline environments

    SciTech Connect

    Lavado, Ramon Rimoldi, John M.; Schlenk, Daniel

    2009-03-01

    Previous studies in rainbow trout have shown that acclimation to hypersaline environments enhances the toxicity to thioether organophosphate and carbamate pesticides. In order to determine the role of biotransformation in this process, the metabolism of the thioether organophosphate biocide, fenthion was evaluated in microsomes from gills, liver and olfactory tissues in rainbow trout (Oncorhynchus mykiss) acclimated to freshwater and 17 per mille salinity. Hypersalinity acclimation increased the formation of fenoxon and fenoxon sulfoxide from fenthion in liver microsomes from rainbow trout, but not in gills or in olfactory tissues. NADPH-dependent and independent hydrolysis was observed in all tissues, but only NADPH-dependent fenthion cleavage was differentially modulated by hypersalinity in liver (inhibited) and gills (induced). Enantiomers of fenthion sulfoxide (65% and 35% R- and S-fenthion sulfoxide, respectively) were formed in liver and gills. The predominant pathway of fenthion activation in freshwater appears to be initiated through initial formation of fenoxon which may be subsequently converted to the most toxic metabolite fenoxon R-sulfoxide. However, in hypersaline conditions both fenoxon and fenthion sulfoxide formation may precede fenoxon sulfoxide formation. Stereochemical evaluation of sulfoxide formation, cytochrome P450 inhibition studies with ketoconazole and immunoblots indicated that CYP3A27 was primarily involved in the enhancement of fenthion activation in hypersaline-acclimated fish with limited contribution of FMO to initial sulfoxidation.

  20. Metagenomic Insights into the Uncultured Diversity and Physiology of Microbes in Four Hypersaline Soda Lake Brines.

    PubMed

    Vavourakis, Charlotte D; Ghai, Rohit; Rodriguez-Valera, Francisco; Sorokin, Dimitry Y; Tringe, Susannah G; Hugenholtz, Philip; Muyzer, Gerard

    2016-01-01

    Soda lakes are salt lakes with a naturally alkaline pH due to evaporative concentration of sodium carbonates in the absence of major divalent cations. Hypersaline soda brines harbor microbial communities with a high species- and strain-level archaeal diversity and a large proportion of still uncultured poly-extremophiles compared to neutral brines of similar salinities. We present the first "metagenomic snapshots" of microbial communities thriving in the brines of four shallow soda lakes from the Kulunda Steppe (Altai, Russia) covering a salinity range from 170 to 400 g/L. Both amplicon sequencing of 16S rRNA fragments and direct metagenomic sequencing showed that the top-level taxa abundance was linked to the ambient salinity: Bacteroidetes, Alpha-, and Gamma-proteobacteria were dominant below a salinity of 250 g/L, Euryarchaeota at higher salinities. Within these taxa, amplicon sequences related to Halorubrum, Natrinema, Gracilimonas, purple non-sulfur bacteria (Rhizobiales, Rhodobacter, and Rhodobaca) and chemolithotrophic sulfur oxidizers (Thioalkalivibrio) were highly abundant. Twenty-four draft population genomes from novel members and ecotypes within the Nanohaloarchaea, Halobacteria, and Bacteroidetes were reconstructed to explore their metabolic features, environmental abundance and strategies for osmotic adaptation. The Halobacteria- and Bacteroidetes-related draft genomes belong to putative aerobic heterotrophs, likely with the capacity to ferment sugars in the absence of oxygen. Members from both taxonomic groups are likely involved in primary organic carbon degradation, since some of the reconstructed genomes encode the ability to hydrolyze recalcitrant substrates, such as cellulose and chitin. Putative sodium-pumping rhodopsins were found in both a Flavobacteriaceae- and a Chitinophagaceae-related draft genome. The predicted proteomes of both the latter and a Rhodothermaceae-related draft genome were indicative of a "salt-in" strategy of osmotic

  1. Metagenomic Insights into the Uncultured Diversity and Physiology of Microbes in Four Hypersaline Soda Lake Brines

    PubMed Central

    Vavourakis, Charlotte D.; Ghai, Rohit; Rodriguez-Valera, Francisco; Sorokin, Dimitry Y.; Tringe, Susannah G.; Hugenholtz, Philip; Muyzer, Gerard

    2016-01-01

    Soda lakes are salt lakes with a naturally alkaline pH due to evaporative concentration of sodium carbonates in the absence of major divalent cations. Hypersaline soda brines harbor microbial communities with a high species- and strain-level archaeal diversity and a large proportion of still uncultured poly-extremophiles compared to neutral brines of similar salinities. We present the first “metagenomic snapshots” of microbial communities thriving in the brines of four shallow soda lakes from the Kulunda Steppe (Altai, Russia) covering a salinity range from 170 to 400 g/L. Both amplicon sequencing of 16S rRNA fragments and direct metagenomic sequencing showed that the top-level taxa abundance was linked to the ambient salinity: Bacteroidetes, Alpha-, and Gamma-proteobacteria were dominant below a salinity of 250 g/L, Euryarchaeota at higher salinities. Within these taxa, amplicon sequences related to Halorubrum, Natrinema, Gracilimonas, purple non-sulfur bacteria (Rhizobiales, Rhodobacter, and Rhodobaca) and chemolithotrophic sulfur oxidizers (Thioalkalivibrio) were highly abundant. Twenty-four draft population genomes from novel members and ecotypes within the Nanohaloarchaea, Halobacteria, and Bacteroidetes were reconstructed to explore their metabolic features, environmental abundance and strategies for osmotic adaptation. The Halobacteria- and Bacteroidetes-related draft genomes belong to putative aerobic heterotrophs, likely with the capacity to ferment sugars in the absence of oxygen. Members from both taxonomic groups are likely involved in primary organic carbon degradation, since some of the reconstructed genomes encode the ability to hydrolyze recalcitrant substrates, such as cellulose and chitin. Putative sodium-pumping rhodopsins were found in both a Flavobacteriaceae- and a Chitinophagaceae-related draft genome. The predicted proteomes of both the latter and a Rhodothermaceae-related draft genome were indicative of a “salt-in” strategy of

  2. Biogeography of Nocardiopsis strains from hypersaline environments of Yunnan and Xinjiang Provinces, western China

    PubMed Central

    He, Song-Tao; Zhi, Xiao-Yang; Jiang, Hongchen; Yang, Ling-Ling; Wu, Jin-Yuan; Zhang, Yong-Guang; Hozzein, Wael N.; Li, Wen-Jun

    2015-01-01

    The genus Nocardiopsis is a widespread group within the phylum Actinobacteria and has been isolated from various salty environments worldwide. However, little is known about whether biogeography affects Nocardiopsis distribution in various hypersaline environments. Such information is essential for understanding the ecology of Nocardiopsis. Here we analyzed 16S rRNA, gyrB, rpoB and sodA genes of 78 Nocardiopsis strains isolated from hypersaline environments in Yunnan and Xinjiang Provinces of western China. The obtained Nocardiopsis strains were classified into five operational taxonomic units, each comprising location-specific phylo- and genotypes. Statistical analyses showed that spatial distance and environmental factors substantially influenced Nocardiopsis distribution in hypersaline environments: the former had stronger influence at large spatial scales, whereas the latter was more influential at small spatial scales. PMID:26289784

  3. Hypersalinity toxicity thresholds for nine California ocean plan toxicity test protocols.

    PubMed

    Voorhees, Jennifer P; Phillips, Bryn M; Anderson, Brian S; Siegler, Katie; Katz, Scott; Jennings, Lydia; Tjeerdema, Ron S; Jensen, Joanna; de la Paz Carpio-Obeso, Maria

    2013-11-01

    Currently, several desalination facilities have been proposed to operate or are actually operating in California. These facilities' use of reverse osmosis (RO) may discharge hypersaline reject brine into the marine environment. The risks, if any, this brine would pose to coastal receiving waters are unknown. To test the toxicity of hypersaline brine in the absence of any additional toxic constituents, we prepared brine and tested it with the seven toxicity test organisms listed in the 2009 California Ocean Plan. The most sensitive protocols were the marine larval development tests, whereas the most tolerant to increased salinities were the euryhaline topsmelt, mysid shrimp, and giant kelp tests. Reject brines from the Monterey Bay Aquarium's RO desalination facility were also tested with three species. The effects of the aquarium's brine effluent on topsmelt, mussels, and giant kelp were consistent with those observed in the salinity tolerance experiments. This information will be used by regulators to establish receiving water limitations for hypersaline discharges. PMID:23821235

  4. Biogeography of Nocardiopsis strains from hypersaline environments of Yunnan and Xinjiang Provinces, western China.

    PubMed

    He, Song-Tao; Zhi, Xiao-Yang; Jiang, Hongchen; Yang, Ling-Ling; Wu, Jin-Yuan; Zhang, Yong-Guang; Hozzein, Wael N; Li, Wen-Jun

    2015-01-01

    The genus Nocardiopsis is a widespread group within the phylum Actinobacteria and has been isolated from various salty environments worldwide. However, little is known about whether biogeography affects Nocardiopsis distribution in various hypersaline environments. Such information is essential for understanding the ecology of Nocardiopsis. Here we analyzed 16S rRNA, gyrB, rpoB and sodA genes of 78 Nocardiopsis strains isolated from hypersaline environments in Yunnan and Xinjiang Provinces of western China. The obtained Nocardiopsis strains were classified into five operational taxonomic units, each comprising location-specific phylo- and genotypes. Statistical analyses showed that spatial distance and environmental factors substantially influenced Nocardiopsis distribution in hypersaline environments: the former had stronger influence at large spatial scales, whereas the latter was more influential at small spatial scales. PMID:26289784

  5. Halophiles: biology, adaptation, and their role in decontamination of hypersaline environments.

    PubMed

    Edbeib, Mohamed Faraj; Wahab, Roswanira Abdul; Huyop, Fahrul

    2016-08-01

    The unique cellular enzymatic machinery of halophilic microbes allows them to thrive in extreme saline environments. That these microorganisms can prosper in hypersaline environments has been correlated with the elevated acidic amino acid content in their proteins, which increase the negative protein surface potential. Because these microorganisms effectively use hydrocarbons as their sole carbon and energy sources, they may prove to be valuable bioremediation agents for the treatment of saline effluents and hypersaline waters contaminated with toxic compounds that are resistant to degradation. This review highlights the various strategies adopted by halophiles to compensate for their saline surroundings and includes descriptions of recent studies that have used these microorganisms for bioremediation of environments contaminated by petroleum hydrocarbons. The known halotolerant dehalogenase-producing microbes, their dehalogenation mechanisms, and how their proteins are stabilized is also reviewed. In view of their robustness in saline environments, efforts to document their full potential regarding remediation of contaminated hypersaline ecosystems merits further exploration. PMID:27344438

  6. Geo- and biogeochemical processes in a heliothermal hypersaline lake

    NASA Astrophysics Data System (ADS)

    Zachara, John M.; Moran, James J.; Resch, Charles T.; Lindemann, Stephen R.; Felmy, Andrew R.; Bowden, Mark E.; Cory, Alexandra B.; Fredrickson, James K.

    2016-05-01

    Water chemical variations were investigated over three annual hydrologic cycles in hypersaline, heliothermal, meromictic Hot Lake in north-central Washington State, USA. The lake contains diverse biota with dramatic zonation related to salinity and redox state. Water samples were collected at 10-cm depth intervals through the shallow lake (2.4 m) during 2012-2014, with comprehensive monitoring performed in 2013. Inorganic salt species, dissolved carbon forms (DOC, DIC), oxygen, sulfide, and methane were analyzed in lake water samples. Depth sonde measurements of pH and temperature were also performed to track their seasonal variations. A bathymetric survey of the lake was conducted to enable lake water volume and solute inventory calculations. Sediment cores were collected at low water and analyzed by X-ray diffraction to investigate sediment mineralogy. The primary dissolved salt in Hot Lake water was Mg2+-SO42- whereas sediments were dominated by gypsum (CaSO4·2H2O). Lake water concentrations increased with depth, reaching saturation with epsomite (MgSO4·7H2O) that was exposed at lake bottom. At maximum volume in spring, Hot Lake exhibited a relatively dilute mixolimnion; a lower saline metalimnion with stratified oxygenic and anoxygenic photosynthetic microbiological communities; and a stable, hypersaline monimolimnion, separated from above layers by a chemocline, containing high levels of sulfide and methane. The thickness of the mixolimnion regulates a heliothermal effect that creates temperatures in excess of 60 °C in the underlying metalimnion and monimolimnion. The mixolimnion was dynamic in volume and actively mixed. It displayed large pH variations, in-situ calcium carbonate precipitation, and large evaporative volume losses. The depletion of this layer by fall allowed deeper mixing into the metalimnion, more rapid heat exchange, and lower winter lake temperatures. Solubility calculations indicate seasonal biogenic and thermogenic aragonite

  7. Diel Migrations of Microorganisms within a Benthic, Hypersaline Mat Community

    PubMed Central

    Garcia-Pichel, Ferran; Mechling, Margaret; Castenholz, Richard W.

    1994-01-01

    We studied the diel migrations of several species of microorganisms in a hypersaline, layered microbial mat. The migrations were quantified by repeated coring of the mat with glass capillary tubes. The resulting minicores were microscopically analyzed by using bright-field and epifluorescence (visible and infrared) microscopy to determine depths of coherent layers and were later dissected to determine direct microscopic counts of microorganisms. Microelectrode measurements of oxygen concentration, fiber optic microprobe measurements of light penetration within the mat, and incident irradiance measurements accompanied the minicore sampling. In addition, pigment content, photosynthesis and irradiance responses, the capacity for anoxygenic photosynthesis, and gliding speeds were determined for the migrating cyanobacteria. Heavily pigmented Oscillatoria sp. and Spirulina cf. subsalsa migrated downward into the mat during the early morning and remained deep until dusk, when upward migration occurred. The mean depth of the migration (not more than 0.4 to 0.5 mm) was directly correlated with the incident irradiance over the mat surface. We estimated that light intensity at the upper boundary of the migrating cyanobacteria was attenuated to such an extent that photoinhibition was effectively avoided but that intensities which saturated photosynthesis were maintained through most of the daylight hours. Light was a cue of paramount importance in triggering and modulating the migration of the cyanobacteria, even though the migrating phenomenon could not be explained solely in terms of a light response. We failed to detect diel migration patterns for other cyanobacterial species and filamentous anoxyphotobacteria. The sulfide-oxidizing bacterium Beggiatoa sp. migrated as a band that followed low oxygen concentrations within the mat during daylight hours. During the nighttime, part of this population migrated toward the mat surface, but a significant proportion remained deep

  8. Chemical modeling for precipitation from hypersaline hydrofracturing brines.

    PubMed

    Zermeno-Motante, Maria I; Nieto-Delgado, Cesar; Cannon, Fred S; Cash, Colin C; Wunz, Christopher C

    2016-10-15

    Hypersaline hydrofracturing brines host very high salt concentrations, as high as 120,000-330,000 mg/L total dissolved solids (TDS), corresponding to ionic strengths of 2.1-5.7 mol/kg. This is 4-10 times higher than for ocean water. At such high ionic strengths, the conventional equations for computing activity coefficients no longer apply; and the complex ion-interactive Pitzer model must be invoked. The authors herein have used the Pitzer-based PHREEQC computer program to compute the appropriate activity coefficients when forming such precipitates as BaSO4, CaSO4, MgSO4, SrSO4, CaCO3, SrCO3, and BaCO3 in hydrofracturing waters. The divalent cation activity coefficients (γM) were computed in the 0.1 to 0.2 range at 2.1 mol/kg ionic strength, then by 5.7 mol/kg ionic strength, they rose to 0.2 for Ba(2+), 0.6 for Sr(2+), 0.8 for Ca(2+), and 2.1 for Mg(2+). Concurrently, the [Formula: see text] was 0.02-0.03; and [Formula: see text] was 0.01-0.02. While employing these Pitzer-derived activity coefficients, the authors then used the PHREEQC model to characterize precipitation of several of these sulfates and carbonates from actual hydrofracturing waters. Modeled precipitation matched quite well with actual laboratory experiments and full-scale operations. Also, the authors found that SrSO4 effectively co-precipitated radium from hydrofracturing brines, as discerned when monitoring (228)Ra and other beta-emitting species via liquid scintillation; and also when monitoring gamma emissions from (226)Ra. PMID:27470293

  9. Diel Metagenomics and Metatranscriptomics of Elkhorn Slough Hypersaline Microbial Mat

    NASA Astrophysics Data System (ADS)

    Lee, J.; Detweiler, A. M.; Everroad, R. C.; Bebout, L. E.; Weber, P. K.; Pett-Ridge, J.; Bebout, B.

    2014-12-01

    To understand the variation in gene expression associated with the daytime oxygenic phototrophic and nighttime fermentation regimes seen in hypersaline microbial mats, a contiguous mat piece was subjected to sampling at regular intervals over a 24-hour diel period. Additionally, to understand the impact of sulfate reduction on biohydrogen consumption, molybdate was added to a parallel experiment in the same run. 4 metagenome and 12 metatranscriptome Illumina HiSeq lanes were completed over day / night, and control / molybdate experiments. Preliminary comparative examination of noon and midnight metatranscriptomic samples mapped using bowtie2 to reference genomes has revealed several notable results about the dominant mat-building cyanobacterium Microcoleus chthonoplastes PCC 7420. Dominant cyanobacterium M. chthonoplastes PCC 7420 shows expression in several pathways for nitrogen scavenging, including nitrogen fixation. Reads mapped to M. chthonoplastes PCC 7420 shows expression of two starch storage and utilization pathways, one as a starch-trehalose-maltose-glucose pathway, another through UDP-glucose-cellulose-β-1,4 glucan-glucose pathway. The overall trend of gene expression was primarily light driven up-regulation followed by down-regulation in dark, while much of the remaining expression profile appears to be constitutive. Co-assembly of quality-controlled reads from 4 metagenomes was performed using Ray Meta with progressively smaller K-mer sizes, with bins identified and filtered using principal component analysis of coverages from all libraries and a %GC filter, followed by reassembly of the remaining co-assembly reads and binned reads. Despite having relatively similar abundance profiles in each metagenome, this binning approach was able to distinctly resolve bins from dominant taxa, but also sulfate reducing bacteria that are desired for understanding molybdate inhibition. Bins generated from this iterative assembly process will be used for downstream

  10. Preservation of ancestral Cretaceous microflora recovered from a hypersaline oil reservoir.

    PubMed

    Gales, Grégoire; Tsesmetzis, Nicolas; Neria, Isabel; Alazard, Didier; Coulon, Stéphanie; Lomans, Bart P; Morin, Dominique; Ollivier, Bernard; Borgomano, Jean; Joulian, Catherine

    2016-01-01

    Microbiology of a hypersaline oil reservoir located in Central Africa was investigated with molecular and culture methods applied to preserved core samples. Here we show that the community structure was partially acquired during sedimentation, as many prokaryotic 16S rRNA gene sequences retrieved from the extracted DNA are phylogenetically related to actual Archaea inhabiting surface evaporitic environments, similar to the Cretaceous sediment paleoenvironment. Results are discussed in term of microorganisms and/or DNA preservation in such hypersaline and Mg-rich solutions. High salt concentrations together with anaerobic conditions could have preserved microbial/molecular diversity originating from the ancient sediment basin wherein organic matter was deposited. PMID:26965360

  11. Preservation of ancestral Cretaceous microflora recovered from a hypersaline oil reservoir

    PubMed Central

    Gales, Grégoire; Tsesmetzis, Nicolas; Neria, Isabel; Alazard, Didier; Coulon, Stéphanie; Lomans, Bart P.; Morin, Dominique; Ollivier, Bernard; Borgomano, Jean; Joulian, Catherine

    2016-01-01

    Microbiology of a hypersaline oil reservoir located in Central Africa was investigated with molecular and culture methods applied to preserved core samples. Here we show that the community structure was partially acquired during sedimentation, as many prokaryotic 16S rRNA gene sequences retrieved from the extracted DNA are phylogenetically related to actual Archaea inhabiting surface evaporitic environments, similar to the Cretaceous sediment paleoenvironment. Results are discussed in term of microorganisms and/or DNA preservation in such hypersaline and Mg-rich solutions. High salt concentrations together with anaerobic conditions could have preserved microbial/molecular diversity originating from the ancient sediment basin wherein organic matter was deposited. PMID:26965360

  12. Preservation of ancestral Cretaceous microflora recovered from a hypersaline oil reservoir

    NASA Astrophysics Data System (ADS)

    Gales, Grégoire; Tsesmetzis, Nicolas; Neria, Isabel; Alazard, Didier; Coulon, Stéphanie; Lomans, Bart P.; Morin, Dominique; Ollivier, Bernard; Borgomano, Jean; Joulian, Catherine

    2016-03-01

    Microbiology of a hypersaline oil reservoir located in Central Africa was investigated with molecular and culture methods applied to preserved core samples. Here we show that the community structure was partially acquired during sedimentation, as many prokaryotic 16S rRNA gene sequences retrieved from the extracted DNA are phylogenetically related to actual Archaea inhabiting surface evaporitic environments, similar to the Cretaceous sediment paleoenvironment. Results are discussed in term of microorganisms and/or DNA preservation in such hypersaline and Mg-rich solutions. High salt concentrations together with anaerobic conditions could have preserved microbial/molecular diversity originating from the ancient sediment basin wherein organic matter was deposited.

  13. Alkaline "Permanent" Paper.

    ERIC Educational Resources Information Center

    Pacey, Antony

    1991-01-01

    Discussion of paper manufacturing processes and their effects on library materials focuses on the promotion of alkaline "permanent" paper, with less acid, by Canadian library preservation specialists. Standards for paper acidity are explained; advantages of alkaline paper are described, including decreased manufacturing costs; and recyclability is…

  14. Anodes for alkaline electrolysis

    DOEpatents

    Soloveichik, Grigorii Lev

    2011-02-01

    A method of making an anode for alkaline electrolysis cells includes adsorption of precursor material on a carbonaceous material, conversion of the precursor material to hydroxide form and conversion of precursor material from hydroxide form to oxy-hydroxide form within the alkaline electrolysis cell.

  15. Carbon pools and isotopic trends in a hypersaline cyanobacterial mat.

    PubMed

    Wieland, A; Pape, T; Möbius, J; Klock, J-H; Michaelis, W

    2008-03-01

    The fine-scale depth distribution of major carbon pools and their stable carbon isotopic signatures (delta(13)C) were determined in a cyanobacterial mat (Salin-de-Giraud, Camargue, France) to study early diagenetic alterations and the carbon preservation potential in hypersaline mat ecosystems. Particular emphasis was placed on the geochemical role of extracellular polymeric substances (EPS). Total carbon (C(tot)), organic carbon (C(org)), total nitrogen (N(tot)), total hydrolysable amino acids (THAA), carbohydrates, cyanobacteria-derived hydrocarbons (8-methylhexadecane, n-heptadec-5-ene, n-heptadecane) and EPS showed highest concentrations in the top millimetre of the mat and decreased with depth. The hydrocarbons attributed to cyanobacteria showed the strongest decrease in concentration with depth. This correlated well with the depth profiles of oxygenic photosynthesis and oxygen, which were detected in the top 0.6 and 1.05 mm, respectively, at a high down-welling irradiance (1441 micromol photons m(-2) s(-1)). At depths beneath the surface layer, the C(org) was composed mainly of amino acids and carbohydrates. A resistance towards microbial degradation could have resulted from interactions with diverse functional groups present in biopolymers (EPS) and with minerals deposited in the mat. A (13)C enrichment with depth for the total carbon pool (C(tot)) was observed, with delta(13)C values ranging from -16.3 per thousand at the surface to -11.3 per thousand at 9-10 mm depth. Total lipids depicted a delta(13)C value of -17.2 per thousand in the top millimetre and then became depleted in (13)C with depth (-21.7 to -23.3 per thousand). The delta(13)C value of EPS varied only slightly with depth (-16.1 to -17.3 per thousand) and closely followed the delta(13)C value of C(org) at depths beneath 4 mm. The EPS represents an organic carbon pool of preservation potential during early stages of diagenesis in recent cyanobacterial mats as a result of a variety of possible

  16. Contemporary microbes in hypersaline springs that contain fossil carbon

    NASA Astrophysics Data System (ADS)

    Ziolkowski, L. A.; Mykytczuk, N. C.; Whyte, L.; Slater, G. F.

    2011-12-01

    On Axel Heiberg Island, near 80 oN in the Canadian Arctic, perennial hypersaline springs provide a unique environment for cold-active microbes. The neutral pH Gypsum Hill springs originate in a gypsum diaper and flow through 600 m of continuous permafrost before reaching the surface at ~6 oC, 7.5 % NaCl, low dissolved inorganic carbon and rich in both sulfate and sulfide (Pollard et al., 2009). In the first part of the year, when ambient temperatures dip as low as -40 oC, filamentous streamers are abundant under the snow covered run-off channels. These microbial assemblages are not present during the summer, when the snow cover has melted. Culture- and molecular-based analyses of the 16S rRNA gene indicated that the streamers are dominated by a chemolithoautotrophic sulfur-oxidizing Thiomicrospira species and under in situ conditions the streamers oxidized sulfide and thiosulfate and also fixed CO2 (Perreault et al., 2008). We characterized the isotopic composition (13C and 14C) of the microbial community biomarkers as phospholipid fatty acid (PLFA) and glycolipid fatty acid (GLFA) methyl esters. These components represent the cell membranes of the viable microbial community, which are quickly hydrolyzed after cell death and provide insight into the carbon cycling of the organisms. Even though isotopic measurements of the bulk biomass indicate carbon and nitrogen limitation within the system, the streamers are rich in biomass with greater than 109 cells/g. While the PLFA and GLFA profiles were similar, indicating a predominantly gram-negative bacteria community, the 13C composition of these two lipid types was different. The PLFA δ13C indicated a dominant autotrophic signal, while the δ13C of the GLFA had a more heterotrophic signal. While the streamers grow yearly, their 14C age based on the lipid results was 6400 years, indicating utilization of a carbon source that is 14C depleted. We hypothesize that these microbes are using 14C depleted dissolved inorganic

  17. Dynamics of Molecular Hydrogen in Hypersaline Microbial Mars

    NASA Technical Reports Server (NTRS)

    Hoehler, Tori M.; Bebout, Brad M.; Visscher, Pieter T.; DesMarais, David J.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Early Earth microbial communities that centered around the anaerobic decomposition of organic molecular hydrogen as a carrier of electrons, regulator of energy metabolism, and facilitator of syntroph'c microbial interactions. The advent of oxygenic photosynthetic organisms added a highly dynamic and potentially dominant term to the hydrogen economy of these communities. We have examined the daily variations of hydrogen concentrations in cyanobacteria-dominated microbial mats from hypersaline ponds in Baja California Sur, Mexico. These mats bring together phototrophic and anaerobic bacteria (along with virtually all other trophic groups) in a spatially ordered and chemically dynamic matrix that provides a good analog for early Earth microbial ecosystems. Hydrogen concentrations in the photic zone of the mat can be three orders of magnitude or more higher than in the photic zone, which are, in turn, an order of magnitude higher than in the unconsolidated sediments underlying the mat community. Within the photic zone, hydrogen concentrations can fluctuate dramatically during the diel (24 hour day-night) cycle, ranging from less than 0.001% during the day to nearly 10% at night. The resultant nighttime flux of hydrogen from the mat to the environment was up to 17% of the daytime oxygen flux. The daily pattern observed is highly dependent on cyanobacterial species composition within the mat, with Lyngbya-dominated systems having a much greater dynamic range than those dominated by Microcoleus; this may relate largely to differing degrees of nitrogen-fixing and fermentative activity in the two mats. The greatest H2 concentrations and fluxes were observed in the absence of oxygen, suggesting an important potential feedback control in the context of the evolution of atmospheric composition. The impact of adding this highly dynamic photosynthetic term to the hydrogen economy of early microbial ecosystems must have been substantial. From an evolutionary standpoint, the H2

  18. Alkaline igneous rocks

    SciTech Connect

    Fitton, J.G.; Upton, B.G.J.

    1987-01-01

    In this volume, an international team of scientists provides an up-to-date overview of the nature, origin, and evolution of alkaline magmas. Particular attention is paid to carbonatites, lamprophyres, and lamproites which are rock suites of current interest not recently reviewed elsewhere. Recent work on the classical alkaline provinces of East Africa, South Greenland, and the Kola Peninsula is included together with reviews of other areas of alkaline magmatism in North and South America, East Greenland, Europe, West Africa, and the ocean basins. Other papers discuss the impact of experimental isotopic and geochemical studies of the petrogenesis of alkaline rocks. This book will be of interest to petrologists and geochemists studying alkaline igneous rocks, and to other earth scientists as a reference on the rapidly expanding field of igneous petrology.

  19. Draft Genome Sequence of Pantoea anthophila Strain 11-2 from Hypersaline Lake Laysan, Hawaii

    PubMed Central

    Hou, Shaobin; Phan, Nolwenn; Malone Moss, Jennifer S.; Donachie, Stuart P.; Alam, Maqsudul

    2015-01-01

    Most Pantoea spp. have been isolated from plant sources or clinical samples. However, we cultivated Pantoea anthophila 11-2 from hypersaline water from the lake on Laysan, Northwestern Hawaiian Islands. Draft genome sequencing of 11-2 provides a molecular basis for studies in evolution and pathogenicity in Pantoea spp. PMID:25977417

  20. Diversity of bacteria and archaea in hypersaline sediment from Death Valley National Park, California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to phylogenetically analyze microorganisms from the domains Bacteria and Archaea in hypersaline sediment from Death Valley National Park. Using domain-specific primers, a region of the 16S rRNA gene was amplified using PCR, and the product was subsequently used to cr...

  1. Do copepods inhabit hypersaline waters worldwide? A short review and discussion

    NASA Astrophysics Data System (ADS)

    Anufriieva, Elena V.

    2015-11-01

    A small number of copepod species have adapted to an existence in the extreme habitat of hypersaline water. 13 copepod species have been recorded in the hypersaline waters of Crimea (the largest peninsula in the Black Sea with over 50 hypersaline lakes). Summarizing our own and literature data, the author concludes that the Crimean extreme environment is not an exception: copepod species dwell in hypersaline waters worldwide. There are at least 26 copepod species around the world living at salinity above 100; among them 12 species are found at salinity higher than 200. In the Crimea Cletocamptus retrogressus is found at salinity 360×10-3 (with a density of 1 320 individuals/m3) and Arctodiaptomus salinus at salinity 300×10-3 (with a density of 343 individuals/m3). Those species are probably the most halotolerant copepod species in the world. High halotolerance of osmoconforming copepods may be explained by exoosmolyte consumption, mainly with food. High tolerance to many factors in adults, availability of resting stages, and an opportunity of long-distance transportation of resting stages by birds and/or winds are responsible for the wide geographic distribution of these halophilic copepods.

  2. Alkaline battery operational methodology

    DOEpatents

    Sholklapper, Tal; Gallaway, Joshua; Steingart, Daniel; Ingale, Nilesh; Nyce, Michael

    2016-08-16

    Methods of using specific operational charge and discharge parameters to extend the life of alkaline batteries are disclosed. The methods can be used with any commercial primary or secondary alkaline battery, as well as with newer alkaline battery designs, including batteries with flowing electrolyte. The methods include cycling batteries within a narrow operating voltage window, with minimum and maximum cut-off voltages that are set based on battery characteristics and environmental conditions. The narrow voltage window decreases available capacity but allows the batteries to be cycled for hundreds or thousands of times.

  3. Brackish to hypersaline lake dolostones of the Mississippian

    NASA Astrophysics Data System (ADS)

    Bennett, Carys; Kearsey, Timothy; Davies, Sarah; Millward, David; Marshall, John

    2016-04-01

    , and 9% of all dolostone beds in the Norham Core are pedogenically altered. The isotopic composition of dolomite beds is δ18O -3.6‰ to -1.7‰ and δ13C -2.6‰ to 1.6‰ which is consistent with a brackish as opposed to marine origin. The dolostones are categorised by their sedimentary composition: Facies 1: Cemented siltstone and sandstone; Facies 2: Homogeneous micrite to micro-crystaline dolomite, within a clay matrix; Facies 3: Bedded dolomite and siltstone; Facies 4: Mixed calcite and dolomite; Facies 5: Dolomite with gypsum and anhydrite. Formation processes are diverse, and include diagenetic cementation (Facies 1), deposition in saline (brackish) lakes (Facies 2), deposition in saline lakes with clastic sediment input (Facies 3), lagoonal to shallow-marine carbonate deposition (Facies 4), and hypersaline lake to sabkha environments (Facies 5). 60% of the beds are facies 2 or 3 and their sedimentology, fauna, ichnofauna and isotopic composition indicate a brackish-water origin. Other Mississippian dolostones from around the world also contain a fairly restricted fauna and have been interpreted as brackish water deposits. The mechanism of dolomite formation under these conditions is discussed. These dolostones provided extensive coastal lakes that may have been an important habitat for tetrapods and other transitional groups during the Mississippian.

  4. Digital Bathymetric Model of Mono Lake, California

    USGS Publications Warehouse

    Raumann, Christian G.; Stine, Scott; Evans, Alexander; Wilson, Jerry

    2002-01-01

    In 1986 and 1987, Pelagos Corporation of San Diego (now Racal Pelagos) undertook a bathymetric survey of Mono Lake in eastern California for the Los Angeles Department of Water and Power (DWP). The result of that survey was a series of maps at various scales and contour intervals. From these maps, the DWP hoped to predict consequences of the drop in lake level that resulted from their diversion of streams in the Mono Basin. No digital models, including shaded-relief and perspective-view renderings, were made from the data collected during the survey. With the permission of Pelagos Corporation and DWP, these data are used to produce a digital model of the floor of Mono Lake. The model was created using a geographic information system (GIS) to incorporate these data with new observations and measurements made in the field. This model should prove to be a valuable tool for enhanced visualization and analyses of the floor of Mono Lake.

  5. Phylogeny and ecology of the ubiquitous saprobe Cladosporium sphaerospermum, with descriptions of seven new species from hypersaline environments.

    PubMed

    Zalar, P; de Hoog, G S; Schroers, H-J; Crous, P W; Groenewald, J Z; Gunde-Cimerman, N

    2007-01-01

    Saprobic Cladosporium isolates morphologically similar to C. sphaerospermum are phylogenetically analysed on the basis of DNA sequences of the ribosomal RNA gene cluster, including the internal transcribed spacer regions ITS1 and ITS2, the 5.8S rDNA (ITS) and the small subunit (SSU) rDNA as well as beta-tubulin and actin gene introns and exons. Most of the C. sphaerospermum-like species show halotolerance as a recurrent feature. Cladosporium sphaerospermum, which is characterised by almost globose conidia, is redefined on the basis of its ex-neotype culture. Cladosporium dominicanum, C. psychrotolerans, C. velox, C. spinulosum and C. halotolerans, all with globoid conidia, are newly described on the basis of phylogenetic analyses and cryptic morphological and physiological characters. Cladosporium halotolerans was isolated from hypersaline water and bathrooms and detected once on dolphin skin. Cladosporium dominicanum and C. velox were isolated from plant material and hypersaline water. Cladosporium psychrotolerans, which grows well at 4 degrees C but not at 30 degrees C, and C. spinulosum, having conspicuously ornamented conidia with long digitate projections, are currently only known from hypersaline water. We also newly describe C. salinae from hypersaline water and C. fusiforme from hypersaline water and animal feed. Both species have ovoid to ellipsoid conidia and are therefore reminiscent of C. herbarum. Cladosporium langeronii (= Hormodendrum langeronii) previously described as a pathogen on human skin, is halotolerant but has not yet been recorded from hypersaline environments. PMID:18490999

  6. Removal performance and microbial communities in a sequencing batch reactor treating hypersaline phenol-laden wastewater.

    PubMed

    Jiang, Yu; Wei, Li; Zhang, Huining; Yang, Kai; Wang, Hongyu

    2016-10-01

    Hypersaline phenol-rich wastewater is hard to be treated by traditional biological systems. In this work, a sequencing batch reactor was used to remove phenol from hypersaline wastewater. The removal performance was evaluated in response to the variations of operating parameters and the microbial diversity was investigated by 454 pyrosequencing. The results showed that the bioreactor had high removal efficiency of phenol and was able to keep stable with the increase of initial phenol concentration. DO, pH, and salinity also affected the phenol removal rate. The most abundant bacterial group was phylum Proteobacteria in the two working conditions, and class Gammaproteobacteria as well as Alphaproteobacteria was predominant subgroup. The abundance of bacterial clusters was notably different along with the variation of operation conditions, resulting in changes of phenol degradation rates. The high removal efficiency of phenol suggested that the reactor might be promising in treating phenol-laden industrial wastewater in high-salt condition. PMID:27359064

  7. Dependence of juvenile reef fishes on semi-arid hypersaline estuary microhabitats as nurseries.

    PubMed

    Sales, N S; Dias, T L P; Baeta, A; Pessanha, A L M

    2016-07-01

    The differences between fish assemblages in three microhabitat types, in relation to vegetation and sediment characteristics of a hypersaline estuary located in an semi-arid zone in north-eastern Brazil, were investigated. Fishes were collected using a beach seine during the rainy and dry seasons in 2012. A total of 78 species were recorded, with the most common families being Gerreidae, Lutjanidae and Tetraodontidae. The majority of species were represented by juveniles, with Eucinostomus argenteus, Ulaema lefroyi and Sphoeroides greeleyi being the dominant species. The fish assemblage structures differed significantly among microhabitat types, with the narrow intertidal flat adjacent to the mangrove fringe supporting the most diverse fish fauna. In addition, only 27 species were common to all of the microhabitats. The results support the hypothesis that hypersaline estuaries serve as important nursery areas for various reef fish species, due to the structural complexity provided by their macroalgae beds and mangroves. PMID:27237742

  8. Chemistry of modern sediments in a hypersaline lagoon, north of Jeddah, Red Sea

    NASA Astrophysics Data System (ADS)

    El-Sayed, Mahmoud Kh.

    1987-10-01

    Previous studies of modern peritidal sedimentary environments of the Red Sea, such as hypersaline lagoons and sea-marginal flats, have concentrated on its northern part, particularly in the Gulf of Aqaba. However, little is known about lagoon sediments in other localities along the Red Sea coastal stretches. This paper deals with the chemical characteristics of the sediments of a hypersaline (Ras Hatiba) lagoon, north of Jeddah, Saudi Arabia. The chemistry of hypersaline lagoon sediments is considerably changed following the modifications to the water chemistry by evaporation and precipitation. Ras Hatiba lagoon is a hypersaline elongated water body connected to the Red Sea by a narrow and shallow opening. The total area of the lagoon is c. 30 km 2. Coarse bioclastic sands are dominant in the lagoon and mostly surround lithified calcareous grounds. However, fine silt and clay sediments are present in separate patches. The sediments are rich in carbonates (average 78·5%) and organic carbon (average 7·3%), although they are negatively correlated. Calcium (average 25·1%) and magnesium (average 10·8‰) show a similar distribution pattern in the lagoon sediments. Strontium (average 5·2‰) is positively correlated with calcium. Sodium and potassium are relatively highly concentrated in the sediments (average 118 ppm and 173 ppm, respectively). Magnesium and strontium are of prime importance in the process of mineralization and diagenesis. The sabkha formation surrounding the lagoon is of low carbonate and organic carbon content, compared with the lagoon sediments, whilst it is characterized by high magnesium, sodium and potassium concentrations. Ras Hatiba lagoon sediments and sabkha resemble those of the northern Red Sea in the Gulfs of Aqaba and Suez and the Arabian Gulf in their major sedimentological and chemical characteristics.

  9. Geologically controlled bi-directional exchange of groundwater with a hypersaline lake in the Canadian prairies

    NASA Astrophysics Data System (ADS)

    Bentley, Laurence R.; Hayashi, Masaki; Zimmerman, Elena P.; Holmden, Chris; Kelley, Lynn I.

    2016-02-01

    Hypersaline lakes occur in hydrologically closed basins due to evaporitic enrichment of dissolved salts transported to the lakes by surface water and groundwater. At the hypersaline Lydden Lake in Saskatchewan, Canada, groundwater/lake-water interaction is strongly influenced by the geological heterogeneity of glacial deposits, whereby a highly permeable glaciofluvial sand/gravel deposit is underlain by glaciolacustrine deposits consisting of dense clay interspersed with silt/sand lenses. Pressure head distribution in a near shore area indicates a bi-directional flow system. It consists of topographically driven flow of fresh groundwater towards the lake in the sand/gravel aquifer and density-driven, landward flow of saline groundwater in the underlying glaciolacustrine deposits. Electrical resistivity tomography, and chemical and isotopic composition of groundwater clearly show the landward intrusion of saline water in the heterogeneous unit. The feasibility of bi-directional flow and transport is supported by numerical simulations of density-coupled groundwater flow and transport. The results suggest that the geologically controlled groundwater exchange processes have substantial influences on both inputs and outputs of dissolved minerals in hypersaline lakes in closed basins.

  10. Trophic ecology and food consumption of fishes in a hypersaline tropical lagoon.

    PubMed

    Almeida-Silva, P H; Tubino, R A; Zambrano, L C; Hunder, D A; Garritano, S R; Monteiro-Neto, C

    2015-06-01

    This study evaluated the trophic ecology (diet composition, trophic strategy, similarities and overlap between species, feeding period and food consumption) of six benthivorous fish species in Araruama Lagoon, the largest hypersaline tropical lagoon on the east coast of South America, with an area of 210 km(2) and an average salinity of 52. The burrfish Chilomycterus spinosus fed on Anomalocardia flexuosa shell deposits, ingesting associated fauna. The caitipa mojarra Diapterus rhombeus differed from all other species, having not only the highest proportions of algae and Nematoda, but also feeding on polychaete tentacles. The two mojarras Eucinostomus spp. showed similar trophic strategies, feeding mostly on Polychaeta. The corocoro grunt Orthopristis ruber also fed mainly on Polychaeta, but differed from Eucinostomus spp. in secondary items. The whitemouth croacker Micropogonias furnieri fed mainly on small Crustacea at night, showing a high number of secondary prey items with low frequencies and high prey-specific abundance. The daily food consumption (g food g(-1) fish mass) for Eucinostomus argenteus was 0·012 and was 0·031 and 0·027 for M. furnieri in two different sampling events. The diet similarities between Araruama Lagoon and other brackish and marine environments indicate that hypersalinity is not a predominant factor shaping the trophic ecology of fishes in this lagoon. The stability of hypersaline conditions, without a pronounced gradient, may explain the presence of several euryhaline fishes and invertebrates well adapted to this condition, resulting in a complex food web. PMID:26033293

  11. The density-driven circulation of the coastal hypersaline system of the Great Barrier Reef, Australia.

    PubMed

    Salamena, Gerry G; Martins, Flávio; Ridd, Peter V

    2016-04-15

    The coastal hypersaline system of the Great Barrier Reef (GBR) in the dry season, was investigated for the first time using a 3D baroclinic model. In the shallow coastal embayments, salinity increases to c.a. 1‰ above typical offshore salinity (~35.4‰). This salinity increase is due to high evaporation rates and negligible freshwater input. The hypersalinity drifts longshore north-westward due to south-easterly trade winds and may eventually pass capes or headlands, e.g. Cape Cleveland, where the water is considerably deeper (c.a. 15m). Here, a pronounced thermohaline circulation is predicted to occur which flushes the hypersalinity offshore at velocities of up to 0.08m/s. Flushing time of the coastal embayments is around 2-3weeks. During the dry season early summer, the thermohaline circulation reduces and therefore, flushing times are predicted to be slight longer due to the reduced onshore-offshore density gradient compared to that in the dry season winter period. PMID:26880128

  12. Dispersion and transport of hypersaline gravity currents in the presence of internal waves at a pycnocline

    NASA Astrophysics Data System (ADS)

    Hogg, C. A. R.; Pietrasz, V. B.; Ouellette, N. T.; Koseff, J. R.

    2015-12-01

    Desalination of seawater offers a source of potable water in arid regions and during drought. However, hypersaline discharge from desalination facilities presents environmental risks, particularly to benthic organisms. The risks posed by salt levels and chemical additives, which can be toxic to local ecosystems, are typically mitigated by ensuring high levels of dilution close to the source. We report on laboratory flume experiments examining how internal waves at the pycnocline of a layered ambient density stratification influence the transport of hypersaline effluent moving as a gravity current down the slope. We found that some of the hypersaline fluid from the gravity current was diverted away from the slope into an intrusion along the pycnocline. A parametric study investigated how varying the energy of the internal wave altered the amount of dense fluid that was diverted into the pycnocline intrusion. The results are compared to an analytical framework that compares the incident energy in the internal wave to potential energy used in diluting the gravity current. These results are significant for desalination effluents because fluid diverted into the intrusion avoids the ecologically sensitive benthic layer and disperses more quickly than if it had continued to propagate along the bed.

  13. Geologically controlled bi-directional exchange of groundwater with a hypersaline lake in the Canadian prairies

    NASA Astrophysics Data System (ADS)

    Bentley, Laurence R.; Hayashi, Masaki; Zimmerman, Elena P.; Holmden, Chris; Kelley, Lynn I.

    2016-06-01

    Hypersaline lakes occur in hydrologically closed basins due to evaporitic enrichment of dissolved salts transported to the lakes by surface water and groundwater. At the hypersaline Lydden Lake in Saskatchewan, Canada, groundwater/lake-water interaction is strongly influenced by the geological heterogeneity of glacial deposits, whereby a highly permeable glaciofluvial sand/gravel deposit is underlain by glaciolacustrine deposits consisting of dense clay interspersed with silt/sand lenses. Pressure head distribution in a near shore area indicates a bi-directional flow system. It consists of topographically driven flow of fresh groundwater towards the lake in the sand/gravel aquifer and density-driven, landward flow of saline groundwater in the underlying glaciolacustrine deposits. Electrical resistivity tomography, and chemical and isotopic composition of groundwater clearly show the landward intrusion of saline water in the heterogeneous unit. The feasibility of bi-directional flow and transport is supported by numerical simulations of density-coupled groundwater flow and transport. The results suggest that the geologically controlled groundwater exchange processes have substantial influences on both inputs and outputs of dissolved minerals in hypersaline lakes in closed basins.

  14. Status of macrobenthic communities in the hypersaline waters of the Gulf of Salwa, Arabian Gulf

    NASA Astrophysics Data System (ADS)

    Joydas, T. V.; Qurban, Mohammad A.; Manikandan, K. P.; Ashraf, T. T. M.; Ali, S. M.; Al-Abdulkader, Khaled; Qasem, Ali; Krishnakumar, P. K.

    2015-05-01

    The spatial extent of hypersaline marine ecosystems is very limited and therefore they have received only little scientific study. Here, we present the status of macrobenthic communities in a hypersaline water body, the Gulf of Salwa (Saudi Arabia part), in the Arabian Gulf and assess the natural stress, if any, in the communities. The Gulf of Salwa is nearly isolated from the main water body of the Arabian Gulf and shows a progressive southward increases in salinity (up to 63 during summer) and temperature (up to 40 °C during summer) due to the southward decrease in tidal flushing. The study reveals that the benthic communities in the southern region (south of 25° 10‧ N) of the Gulf of Salwa are under natural stress, while the deeper, the northern, and the inner bay regions have healthier benthic communities than the south. In the southern region, there were 87 to 93% reduction in polychaete species, 49 to 57% reduction in species diversity of polychaetes and 70 to 71% in non-polychaete taxa compared to the northern region. The present study identified some opportunistic taxa such as Fabricia sp., Heteromastus filiformis, Platynereis insolita and Nereis sp. 1 and non-polychaetes such as chironomid larvae, podocops and cumaceans capable of adapting to the hypersaline environment in the Gulf of Salwa when salinity exceeded 60 and temperature exceeded 35 °C during summer.

  15. Polyamine effects on protein disulfide isomerase expression and implications for hypersalinity stress in the marine alga Ulva lactuca Linnaeus(1).

    PubMed

    Li, Lu-Chuan; Hsu, Yuan-Ting; Chang, Hsueh-Ling; Wu, Tzure-Meng; Sung, Ming-Shiuan; Cho, Chung-Lung; Lee, Tse-Min

    2013-12-01

    Full-length protein disulfide isomerase (UfPDI) cDNA was cloned from the intertidal macroalga Ulva lactuca Linnaeus. Modulation of UfPDI expression by stresses and polyamines (PA) was studied. UfPDI transcription and enzyme activity were increased by hypersalinity (90) or high light illumination (1,200 μmol photons · m(-2)  · s(-1) ), decreased by the addition of 100 μM CuSO4 . An exposure to a salinity of 90 decreased PA contents. Treating with PA biosynthetic inhibitors, D-arginine (D-Arg) or α-methyl ornithine (α-MO), led to a further decrease and also inhibited UfPDI expression and recovery of the growth rate. These results suggest that PAs are required to activate UfPDI expression with hypersalinity, even PA contents are decreased at a salinity of 90. The induction of UfPDI expression by hypersalinity of 90 and tolerance to hypersalinity could be enhanced if internal PA contents rise. Sung et al. (2011b) showed that PA contents could be increased by pretreating with putrescine (Put, 1 mM), spermidine (Spd, 1 mM), or spermine (Spm, 1 mM) at a salinity of 30. Therefore, PA pretreatment effect on UfPDI expression was examined. Pretreatment with Spd and Spm, but not with Put, enhanced UfPDI expression after transferred to a salinity of 90 and restored the growth rate. In conclusion, induction of UfPDI expression by Spd or Spm before exposure to hypersaline conditions and continuous up-regulation after hypersalinity exposure are required for the acquisition of hypersalinity tolerance in the intertidal green macroalga U. lactuca. PMID:27007636

  16. Alkaline flooding injection strategy

    SciTech Connect

    French, T.R.; Josephson, C.B.

    1992-03-01

    The objective of this project is to improved alkali-surfactant flooding methods, and this includes determining the proper design of injection strategy. Several different injection strategies have been used or suggested for recovering heavy oils with surfactant-enhanced alkaline flooding methods. Oil recovery was compared for four different injection strategies: (1) surfactant followed by polymer, (2) surfactant followed by alkaline polymer, (3) alkaline surfactant followed by polymer, and (4) alkali, surfactant, and polymer mixed in a single formulation. The effect of alkaline preflush was also studied under two different conditions. All of the oil recovery experiments were conducted under optimal conditions with a viscous, non-acidic oil from Hepler (KS) oil field. The coreflood experiments were conducted with Berea sandstone cores since field core was not available in sufficient quantity for coreflood tests. The Tucker sand of Hepler field is a Class I fluvial dominated deltaic reservoir, as classified by the Department of Energy, which has been selected as the site of a DOE-sponsored field pilot test.

  17. Resonant mono Higgs at the LHC

    NASA Astrophysics Data System (ADS)

    Basso, Lorenzo

    2016-04-01

    In recent years, the production of a SM particle with large missing transverse momentum, dubbed mono-X searches, have gained increasing attention. After the discovery of the Higgs boson in 2012, the run-II of the LHC will now scrutinise its properties, looking for BSM physics. In particular, one could search for mono-Higgs signals, that are typically studied in models addressing dark matter. However, this signal can appear also in models addressing the neutrino masses, if additional heavier neutrinos with masses at the electroweak scale are present. The latter will couple to the SM neutrinos and the Higgs boson, yielding a type of mono-Higgs signal not considered for dark matter: the resonant production of a Higgs boson and missing energy. In this paper, we address the LHC exclusion power of the latter with dedicated detector simulations, and reinterpret it in a benchmark scenario for neutrino mass generation.

  18. Gravity and magnetic investigations of the Mono-Inyo Volcanic Chain, Mono Basin, California

    NASA Astrophysics Data System (ADS)

    Pera, A. A.; Ponce, D. A.; McPhee, D. K.; Battaglia, M.

    2010-12-01

    The Mono Inyo volcanic chain is a 25-km long, north-south trending series of domes and craters extending southward from Mono Lake and into the west moat of Long Valley Caldera. Based on the Holocene history of eruptions in the area, the chain appears to hold the greatest potential for renewed magmatic activity (Hildreth, 2004). To better characterize the geometry and structure of Mono Basin for future dynamic modeling of the Mono Inyo volcanic chain a new gravity and magnetic survey was conducted. We collected gravity data at over 320 stations in and around the northern and central region of the Mono-Inyo volcanic chain and around Mono Lake in the summer of 2010. Regional gravity data was collected at one-mile spacing and data collected on profile lines was collected at quarter-mile intervals. We collected magnetic data on major roads along several transects across Mono Basin that include one coincident with a seismic refraction line (Hill and others, 1985). Rock samples were collected for analysis of density and magnetic susceptibility. The new gravity and magnetic data will be compiled with pre-existing data from studies dating back to the 1960’s (Pakiser and others, 1960, 1976; Christensen, 1969) to produce new isostatic gravity and magnetic anomaly maps. Preliminary isostatic gravity and magnetic maps from pre-existing data show the presence of gravity and magnetic lows in Mono Lake and Long Valley Caldera where low density volcanic sediments are prevalent; gravity highs were observed to the east and west of Mono Lake and to the east of Long Valley Caldera. A region with a high magnetic anomaly lies to the east of the volcanic chain. Two-dimensional forward modeling of potential field data along profiles that extend across Mono Basin will constrain the density and magnetization distribution, stratification and structural geology of the Mono-Inyo volcanic chain. These efforts are critical to improve dynamic modeling of Sierran range-front faulting and dike

  19. Mono versus Stereo: Bilingualism's Double Face.

    ERIC Educational Resources Information Center

    Grutman, Rainier

    1993-01-01

    Offers an application of Mikhail Bakhtin's heteroglossia model, describing literature from a diversified point of view. Analyzes two examples to show nevertheless that Bakhtin unilaterally celebrates "stereo" qualities of language blending, and leaves no room for "mono" texts, which use polyglot devices as borders much more than as bridges between…

  20. Educational and Demographic Profile: Mono County.

    ERIC Educational Resources Information Center

    California Postsecondary Education Commission, 2004

    2004-01-01

    This profile uniquely presents a variety of educational and socioeconomic information for Mono County, nearby counties, and the state. The profile highlights the relationship between various factors that affect the economic well-being of individuals and communities. This presentation of information provides a framework for enhanced communication…

  1. Alkaline quinone flow battery.

    PubMed

    Lin, Kaixiang; Chen, Qing; Gerhardt, Michael R; Tong, Liuchuan; Kim, Sang Bok; Eisenach, Louise; Valle, Alvaro W; Hardee, David; Gordon, Roy G; Aziz, Michael J; Marshak, Michael P

    2015-09-25

    Storage of photovoltaic and wind electricity in batteries could solve the mismatch problem between the intermittent supply of these renewable resources and variable demand. Flow batteries permit more economical long-duration discharge than solid-electrode batteries by using liquid electrolytes stored outside of the battery. We report an alkaline flow battery based on redox-active organic molecules that are composed entirely of Earth-abundant elements and are nontoxic, nonflammable, and safe for use in residential and commercial environments. The battery operates efficiently with high power density near room temperature. These results demonstrate the stability and performance of redox-active organic molecules in alkaline flow batteries, potentially enabling cost-effective stationary storage of renewable energy. PMID:26404834

  2. Hydrology and Salt Balance in a Large, Hypersaline Coastal Lagoon: Lagoa de Araruama, Brazil

    NASA Astrophysics Data System (ADS)

    Kjerfve, Björn; Schettini, C. A. F.; Knoppers, Bastiaan; Lessa, Guilherme; Ferreira, H. O.

    1996-06-01

    Lagoa de Araruama in the state of Rio de Janeiro, Brazil, is a hypersaline coastal lagoon as a result of semi-arid climate conditions, a small drainage basin and a choked entrance channel. The lagoon has been continuously hypersaline for at least 4·5 centuries, but the mean salinity has varied substantially. It has recently decreased from 57 to 52 as indicated by density (salinity) measurements between 1965 and 1990. Analysis of more than 20 years of salinity time series data, in addition to monthly lagoon cruises to measure the spatial salinity distribution, indicate that the lagoon salinity largely fluctuates in response to the difference between evaporation and precipitation. The major factor explaining the long-term trend of decreasing salinity in the lagoon is the constant pumping of 1 m 3s -1of freshwater to the communities surrounding the lagoon from an adjacent watershed, and subsequent discharge of this water into Lagoa de Araruama. The net salt budget is primarily a balance between the advective import of salt from the coastal ocean and eddy diffusive export of salt to the ocean, although the extensive mining of salt from the lagoon during past decades is also a small but significant contribution to the salt budget. The flushing half-life is proposed as a useful time scale of water exchange, is calculated based on a combination of hydrological and tidal processes, and is excellent for comparison of lagoons and assessing water quality changes. The flushing half-life measures 83·5 days for Lagoa de Araruama, considerably longer than for most other coastal lagoons. The proposed dredging of a second ocean channel to Lagoa de Araruama is probably not a good idea. It is likely to accelerate the decrease of lagoon salinity and somewhat improve the lagoon water exchange. At the same time, this will eliminate the apparent buffering capacity provided by the hypersaline environment, and thus may potentially cause water quality problems.

  3. Development of a Halotolerant Community in the St. Lucia Estuary (South Africa) during a Hypersaline Phase

    PubMed Central

    Carrasco, Nicola K.; Perissinotto, Renzo

    2012-01-01

    Background The St. Lucia Estuary, Africa's largest estuarine lake, is currently experiencing unprecedented freshwater deprivation which has resulted in a northward gradient of drought effects, with hypersaline conditions in its northern lakes. Methodology/Principal Findings This study documents the changes that occurred in the biotic communities at False Bay from May 2010 to June 2011, in order to better understand ecosystem functioning in hypersaline habitats. Few zooplankton taxa were able to withstand the harsh environmental conditions during 2010. These were the flatworm Macrostomum sp., the harpacticoid copepod Cletocamptus confluens, the cyclopoid copepod Apocyclops cf. dengizicus and the ciliate Fabrea cf. salina. In addition to their exceptional salinity tolerance, they were involved in a remarkably simple food web. In June 2009, a bloom of an orange-pigmented cyanobacterium (Cyanothece sp.) was recorded in False Bay and persisted uninterruptedly for 18 months. Stable isotope analysis suggests that this cyanobacterium was the main prey item of F. cf. salina. This ciliate was then consumed by A. cf. dengizicus, which in turn was presumably consumed by flamingos as they flocked in the area when the copepods attained swarming densities. On the shore, cyanobacteria mats contributed to a population explosion of the staphylinid beetle Bledius pilicollis. Although zooplankton disappeared once salinities exceeded 130, many taxa are capable of producing spores or resting cysts to bridge harsh periods. The hypersaline community was disrupted by heavy summer rains in 2011, which alleviated drought conditions and resulted in a sharp increase in zooplankton stock and diversity. Conclusions/Significance Despite the current freshwater deprivation crisis, the False Bay region has shown to be resilient, harboring a unique biodiversity with species that are capable of enduring harsh environmental conditions. However, further freshwater deprivation may extend beyond the

  4. Preserving the world second largest hypersaline lake under future irrigation and climate change.

    PubMed

    Shadkam, Somayeh; Ludwig, Fulco; van Vliet, Michelle T H; Pastor, Amandine; Kabat, Pavel

    2016-07-15

    Iran Urmia Lake, the world second largest hypersaline lake, has been largely desiccated over the last two decades resulting in socio-environmental consequences similar or even larger than the Aral Sea disaster. To rescue the lake a new water management plan has been proposed, a rapid 40% decline in irrigation water use replacing a former plan which intended to develop reservoirs and irrigation. However, none of these water management plans, which have large socio-economic impacts, have been assessed under future changes in climate and water availability. By adapting a method of environmental flow requirements (EFRs) for hypersaline lakes, we estimated annually 3.7·10(9)m(3) water is needed to preserve Urmia Lake. Then, the Variable Infiltration Capacity (VIC) hydrological model was forced with bias-corrected climate model outputs for both the lowest (RCP2.6) and highest (RCP8.5) greenhouse-gas concentration scenarios to estimate future water availability and impacts of water management strategies. Results showed a 10% decline in future water availability in the basin under RCP2.6 and 27% under RCP8.5. Our results showed that if future climate change is highly limited (RCP2.6) inflow can be just enough to meet the EFRs by implementing the reduction irrigation plan. However, under more rapid climate change scenario (RCP8.5) reducing irrigation water use will not be enough to save the lake and more drastic measures are needed. Our results showed that future water management plans are not robust under climate change in this region. Therefore, an integrated approach of future land-water use planning and climate change adaptation is therefore needed to improve future water security and to reduce the desiccating of this hypersaline lake. PMID:27070383

  5. Microbial characterization of a subzero, hypersaline methane seep in the Canadian High Arctic.

    PubMed

    Niederberger, Thomas D; Perreault, Nancy N; Tille, Stephanie; Lollar, Barbara Sherwood; Lacrampe-Couloume, Georges; Andersen, Dale; Greer, Charles W; Pollard, Wayne; Whyte, Lyle G

    2010-10-01

    We report the first microbiological characterization of a terrestrial methane seep in a cryo-environment in the form of an Arctic hypersaline (∼24% salinity), subzero (-5 °C), perennial spring, arising through thick permafrost in an area with an average annual air temperature of -15 °C. Bacterial and archaeal 16S rRNA gene clone libraries indicated a relatively low diversity of phylotypes within the spring sediment (Shannon index values of 1.65 and 1.39, respectively). Bacterial phylotypes were related to microorganisms such as Loktanella, Gillisia, Halomonas and Marinobacter spp. previously recovered from cold, saline habitats. A proportion of the bacterial phylotypes were cultured, including Marinobacter and Halomonas, with all isolates capable of growth at the in situ temperature (-5 °C). Archaeal phylotypes were related to signatures from hypersaline deep-sea methane-seep sediments and were dominated by the anaerobic methane group 1a (ANME-1a) clade of anaerobic methane oxidizing archaea. CARD-FISH analyses indicated that cells within the spring sediment consisted of ∼84.0% bacterial and 3.8% archaeal cells with ANME-1 cells accounting for most of the archaeal cells. The major gas discharging from the spring was methane (∼50%) with the low CH(4)/C(2+) ratio and hydrogen and carbon isotope signatures consistent with a thermogenic origin of the methane. Overall, this hypersaline, subzero environment supports a viable microbial community capable of activity at in situ temperature and where methane may behave as an energy and carbon source for sustaining anaerobic oxidation of methane-based microbial metabolism. This site also provides a model of how a methane seep can form in a cryo-environment as well as a mechanism for the hypothesized Martian methane plumes. PMID:20445635

  6. Linking Archaeal Molecular Diversity and Lipid Biomarker Composition in a Hypersaline Microbial Mat Community

    NASA Technical Reports Server (NTRS)

    Jahnke, Linda; Orphan, Victoria; Turk, Kendra; Embaye, Tsegereda; Kubo, Mike; Summons, Roger

    2005-01-01

    Lipid biomarkers for discrete microbial groups are a valuable tool for establishing links to ancient microbial ecosystems. Lipid biomarkers can establish organism source and function in contemporary microbial ecosystems (membrane lipids) and by analogy, potential relevance to the fossilized carbon skeletons (geolipids) extracted from ancient sedimentary rock. The Mars Exploration Rovers have provided clear evidence for an early wet Mars and the presence of hypersaline evaporitic basins. Ongoing work on an early Earth analog, the hypersaline benthic mats in Guerrero Negro, Baja California Sur, may provide clues to what may have evolved and flourished on an early wet Mars, if only for a short period. Cyanobacterial mats are a pertinent early Earth analog for consideration of evolutionary and microbial processes within the aerobic photosynthetic and adjacent anoxic layers. Fluctuations in physio-chemical parameters associated with spatial and temporal scales are expressed through vast microbial metabolic diversity. Our recent work hopes to establish the dynamic of archaeal diversity, particularly as it relates to methane production in this high sulfate environment, through the use of lipid biomarker and phylogenetic analyses. Archaeal 16s rRNA and mcrA gene assemblages, demonstrated distinct spatial separation over the 130 mm core of at least three distinct genera within the order Methanosarcinales, as well as an abundance of uncultured members of the Thermoplasmales and Crenarchaeota. Ether-bound lipid analysis identified abundant 0-alkyl and 0-isopranyl chains throughout the core, and the presence of sn-2 hydroxyarchaeol, a biomarker for methylotrophic methanogens. A unique ether isoprenoid chain, a C30:1 , possibly related to the geolipid squalane, a paleobiomarker associated with hypersaline environments, was most abundant within the oxic-anoxic transition zone.

  7. Preserving the World Second Largest Hypersaline Lake under Future Irrigation and Climate Change

    NASA Astrophysics Data System (ADS)

    Shadkam, Somayeh; Ludwig, Fulco; van Vliet, Michelle; Pastor, Amandine; Kabat, Pavel

    2016-04-01

    Urmia Lake, the world second largest hypersaline lake, has been largely desiccated over the last two decades resulting in socio-environmental consequences similar or even larger than the Aral Sea disaster. To rescue the lake a new water management plan has been proposed, a rapid 40% decline in irrigation water use replacing a former plan which intended to develop reservoirs and irrigation. However, none of these water management plans, which have large socio-economic impacts, have been assessed under future changes in climate and water availability. By adapting a method of environmental flow requirements (EFRs) for hypersaline lakes, we estimated annually 3.9•109 m3 water is needed to preserve Urmia Lake. Then, the Variable Infiltration Capacity (VIC) hydrological model was forced with bias-corrected climate model outputs for both the lowest (RCP2.6) and highest (RCP8.5) greenhouse-gas concentration scenarios to estimate future water availability and impacts of water management strategies. Results showed a 10% decline in future water availability in the basin under RCP2.6 and 27% under RCP8.5. Our results showed that if future climate change is highly limited (RCP2.6) inflow can be just enough to meet the EFRs by implementing the reduction irrigation plan. However, under more rapid climate change scenario (RCP8.5) reducing irrigation water use will not be enough to save the lake and more drastic measures are needed. Our results showed that future water management plans are not robust under climate change in this region. Therefore, an integrated approach of future land-water use planning and climate change adaptation is therefore needed to improve future water security and to reduce the desiccating of this hypersaline lake.

  8. Anaerobic oxidation of methane by sulfate in hypersaline groundwater of the Dead Sea aquifer

    PubMed Central

    Avrahamov, N; Antler, G; Yechieli, Y; Gavrieli, I; Joye, S B; Saxton, M; Turchyn, A V; Sivan, O

    2014-01-01

    Geochemical and microbial evidence points to anaerobic oxidation of methane (AOM) likely coupled with bacterial sulfate reduction in the hypersaline groundwater of the Dead Sea (DS) alluvial aquifer. Groundwater was sampled from nine boreholes drilled along the Arugot alluvial fan next to the DS. The groundwater samples were highly saline (up to 6300 mm chlorine), anoxic, and contained methane. A mass balance calculation demonstrates that the very low δ13CDIC in this groundwater is due to anaerobic methane oxidation. Sulfate depletion coincident with isotope enrichment of sulfur and oxygen isotopes in the sulfate suggests that sulfate reduction is associated with this AOM. DNA extraction and 16S amplicon sequencing were used to explore the microbial community present and were found to be microbial composition indicative of bacterial sulfate reducers associated with anaerobic methanotrophic archaea (ANME) driving AOM. The net sulfate reduction seems to be primarily controlled by the salinity and the available methane and is substantially lower as salinity increases (2.5 mm sulfate removal at 3000 mm chlorine but only 0.5 mm sulfate removal at 6300 mm chlorine). Low overall sulfur isotope fractionation observed (34ε = 17 ± 3.5‰) hints at high rates of sulfate reduction, as has been previously suggested for sulfate reduction coupled with methane oxidation. The new results demonstrate the presence of sulfate-driven AOM in terrestrial hypersaline systems and expand our understanding of how microbial life is sustained under the challenging conditions of an extremely hypersaline environment. PMID:25039851

  9. Microbial response to salinity change in Lake Chaka, a hypersaline lake on Tibetan plateau.

    PubMed

    Jiang, Hongchen; Dong, Hailiang; Yu, Bingsong; Liu, Xinqi; Li, Yiliang; Ji, Shanshan; Zhang, Chuanlun L

    2007-10-01

    Previous investigations of the salinity effects on the microbial community composition have largely been limited to dynamic estuaries and coastal solar salterns. In this study, the effects of salinity and mineralogy on microbial community composition was studied by using a 900-cm sediment core collected from a stable, inland hypersaline lake, Lake Chaka, on the Tibetan Plateau, north-western China. This core, spanning a time of 17,000 years, was unique in that it possessed an entire range of salinity from freshwater clays and silty sands at the bottom to gypsum and glauberite in the middle, to halite at the top. Bacterial and archaeal communities were studied along the length of this core using an integrated approach combining mineralogy and geochemistry, molecular microbiology (16S rRNA gene analysis and quantitative polymerase chain reaction), cultivation and lipid biomarker analyses. Systematic changes in microbial community composition were correlated with the salinity gradient, but not with mineralogy. Bacterial community was dominated by the Firmicutes-related environmental sequences and known species (including sulfate-reducing bacteria) in the freshwater sediments at the bottom, but by halophilic and halotolerant Betaproteobacteria and Bacteroidetes in the hypersaline sediments at the top. Succession of proteobacterial groups along the salinity gradient, typically observed in free-living bacterial communities, was not observed in the sediment-associated community. Among Archaea, the Crenarchaeota were predominant in the bottom freshwater sediments, but the halophilic Halobacteriales of the Euryarchaeota was the most important group in the hypersaline sediments. Multiple isolates were obtained along the whole length of the core, and their salinity tolerance was consistent with the geochemical conditions. Iron-reducing bacteria were isolated in the freshwater sediments, which were capable of reducing structural Fe(III) in the Fe(III)-rich clay minerals

  10. Bacterial Community Response to Petroleum Hydrocarbon Amendments in Freshwater, Marine, and Hypersaline Water-Containing Microcosms

    PubMed Central

    Jurelevicius, Diogo; Alvarez, Vanessa Marques; Marques, Joana Montezano; de Sousa Lima, Laryssa Ribeiro Fonseca; Dias, Felipe de Almeida

    2013-01-01

    Hydrocarbon-degrading bacterial communities from freshwater, marine, and hypersaline Brazilian aquatic ecosystems (with water salinities corresponding to 0.2%, 4%, and 5%, respectively) were enriched with different hydrocarbons (heptadecane, naphthalene, or crude oil). Changes within the different microcosms of bacterial communities were analyzed using cultivation approaches and molecular methods (DNA and RNA extraction, followed by genetic fingerprinting and analyses of clone libraries based on the 16S rRNA-coding gene). A redundancy analysis (RDA) of the genetic fingerprint data and a principal component analysis (PCA) of the clone libraries revealed hydrocarbon-enriched bacterial communities specific for each ecosystem studied. However, within the same ecosystem, different bacterial communities were selected according to the petroleum hydrocarbon used. In general, the results demonstrated that Acinetobacter and Cloacibacterium were the dominant genera in freshwater microcosms; the Oceanospirillales order and the Marinobacter, Pseudomonas, and Cycloclasticus genera predominated in marine microcosms; and the Oceanospirillales order and the Marinobacter genus were selected in the different hydrocarbon-containing microcosms in hypersaline water. Determination of total petroleum hydrocarbons (TPHs) in all microcosms after 32 days of incubation showed a decrease in the hydrocarbon concentration compared to that for the controls. A total of 50 (41.3%) isolates from the different hydrocarbon-contaminated microcosms were associated with the dominant operational taxonomic units (OTUs) obtained from the clone libraries, and their growth in the hydrocarbon contaminating the microcosm from which they were isolated as the sole carbon source was observed. These data provide insight into the general response of bacterial communities from freshwater, marine, and hypersaline aquatic ecosystems to petroleum hydrocarbon contamination. PMID:23872573

  11. 40 CFR 721.10551 - Bisphenol S mono ether (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Bisphenol S mono ether (generic). 721... Substances § 721.10551 Bisphenol S mono ether (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as bisphenol S mono ether (PMN...

  12. 40 CFR 721.10551 - Bisphenol S mono ether (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Bisphenol S mono ether (generic). 721... Substances § 721.10551 Bisphenol S mono ether (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as bisphenol S mono ether (PMN...

  13. Response of biotic communities to salinity changes in a Mediterranean hypersaline stream

    PubMed Central

    Velasco, Josefa; Millán, Andrés; Hernández, Juan; Gutiérrez, Cayetano; Abellán, Pedro; Sánchez, David; Ruiz, Mar

    2006-01-01

    Background This study investigates the relationship between salinity and biotic communities (primary producers and macroinvertebrates) in Rambla Salada, a Mediterranean hypersaline stream in SE Spain. Since the 1980's, the mean salinity of the stream has fallen from about 100 g L-1 to 35.5 g L-1, due to intensive irrigated agriculture in the watershed. Furthermore, large dilutions occur occasionally when the water irrigation channel suffers cracks. Results Along the salinity gradient studied (3.5 – 76.4 g L-1) Cladophora glomerata and Ruppia maritima biomass decreased with increasing salinity, while the biomass of epipelic algae increased. Diptera and Coleoptera species dominated the community both in disturbed as in re-established conditions. Most macroinvertebrates species found in Rambla Salada stream are euryhaline species with a broad range of salinity tolerance. Eight of them were recorded in natural hypersaline conditions (~100 g L-1) prior to important change in land use of the watershed: Ephydra flavipes, Stratyomis longicornis, Nebrioporus ceresyi, N. baeticus, Berosus hispanicus, Enochrus falcarius, Ochthebius cuprescens and Sigara selecta. However, other species recorded in the past, such as Ochthebius glaber, O. notabilis and Enochrus politus, were restricted to a hypersaline source or absent from Rambla Salada. The dilution of salinity to 3.5 – 6.8 gL-1 allowed the colonization of species with low salininty tolerance, such as Melanopsis praemorsa, Anax sp., Simulidae, Ceratopogonidae and Tanypodinae. The abundance of Ephydra flavipes and Ochthebius corrugatus showed a positive significant response to salinity, while Anax sp., Simulidae, S. selecta, N. ceresyi, N. baeticus, and B. hispanicus showed significant negative correlations. The number of total macroinvertebrate taxa, Diptera and Coleoptera species, number of families, Margalef's index and Shannon's diversity index decreased with increasing salinity. However, the rest of community

  14. Trace metal geochemistry in deep hypersaline anoxic basin in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Oliveri, Elvira; Sprovieri, Mario; Salvagio Manta, Daniela; Traina, Anna; Mazzola, Salvo

    2014-05-01

    Trace metals accumulation in marine sediments is primarily regulated by redox conditions; specifically, in the geological record, ancient anoxic sediments appear characterized by significant enrichments in redox sensitive elements. In the modern sedimentary record, examples of extreme limitations in dynamic circulation at the sea bottom are represented by the fascinating hypersaline anoxic basins, recently explored in the eastern Mediterranean Sea. These basins present a peculiar layer of "brine" (a mass water with salinity >300o) above the bottom sediments. The seawater-brine is generally located at a depth of about 3000 m below sea level with a thickness up to hundred meters. This transition zone characterized by steep pycno- and chemoclines passes with evident gradients of salinity and Eh to an extremely salty, anoxic a sulfuric seawater (brine). Here, we present geochemical results from two deep hypersaline anoxic basins discovered during two R/V Urania cruises (September 2008,2009), the Thetis and Kryos Basin (22°08'E 34°41'N, 22°01'E 34°56'N). Sediments appear depleted in organic matter (TOC 0.17-1.28o) and some redox-sensitive trace metals (As, Fe, Co, Cu, Zn) do not show the classical enrichments reported for anoxic sediments (e.g., sapropel). The only trace metal favored in the sedimentary accumulation seems to be the Mo. In particular, the documented low Mo/TOC ratios suggest strongly restricted conditions and limited deepwater renewal, and evidence the role played by the hydrographic control on redox conditions and trace metals accumulation in the studied sediments. A comparison among trace metal distribution patterns in hypersaline basins with sediments of other recent anoxic basins shows that the Cr, Ni, V and Zn concentrations are generally comparable thus suggesting similar mechanisms for metal enrichments. On the other hand, a comparison with the geochemistry of ancient anoxic sediments suggests that these anoxic hypersaline basins do not offer

  15. Survival strategies for microorganisms in hypersaline environments and their relevance to life on early Mars

    NASA Astrophysics Data System (ADS)

    Litchfield, Carol D.

    1998-07-01

    There are two groups of microorganisms that live and grow in hypersaline (>10-15% NaCl) environments: the halophilic Archaea and the halotolerant Bacteria and algae. In order to grow and reproduce in such high salt, low water activity environments, these organisms have made basic biochemical adaptations in their proteins, osmoregulation mechanisms, nucleic acids, and lipids. The environment of the halophiles and especially how the halophilic Archaea have adapted to that environment are reviewed in this paper. Along with this review is a brief description of how these adaptations could be important in the detection of life on early Mars assuming similar types of salts and a carbon-based life.

  16. Mollusc-Microbe Mutualisms Extend the Potential for Life in Hypersaline Systems

    NASA Astrophysics Data System (ADS)

    Hickman, Carole S.

    2003-11-01

    Metazoans in extreme environments have evolved mutualisms with microbes that extend the physical and chemical capabilities of both partners. Some of the best examples are bivalve molluscs in evaporite and hypersaline settings. Mollusc tissue is developmentally and evolutionarily amenable to housing vast numbers of symbiotic microbes. Documented benefits to the host are nutritional. Multiple postulated benefits to the microbes are related to optimizing metabolic performance at interfaces, where heterogeneity and steep gradients that cannot be negotiated by microbes can be spanned by larger metazoan hosts. A small cockle, Fragum erugatum, and its photosymbiotic microbes provide a remarkable example of a mutualistic partnership in the hypersaline reaches of Shark Bay, Western Australia. Lucinid bivalves and their endosymbiotic chemolithotrophic bacteria provide examples in which hosts span oxic/anoxic interfaces on behalf of their symbionts at sites of seafloor venting. Multiple lines of evidence underscore the antiquity of mutualisms and suggest that they may have played a significant role in life's first experiments above the prokaryotic grade of complexity. The study of metazoan-microbe mutualisms and their signatures in extreme environments in the geologic record will provide a significant augmentation to microbial models in paleobiology and astrobiology. There are strong potential links between mutualisms and the early history of life on Earth, the persistence of life in extreme environments at times of global crisis and mass extinction, and the possibilities for life elsewhere in the universe.

  17. Unveiling microbial activities along the halocline of Thetis, a deep-sea hypersaline anoxic basin

    PubMed Central

    Pachiadaki, Maria G; Yakimov, Michail M; LaCono, Violetta; Leadbetter, Edward; Edgcomb, Virginia

    2014-01-01

    Deep-sea hypersaline anoxic basins (DHABs) in the Eastern Mediterranean Sea are considered some of the most hostile environments on Earth. Little is known about the biochemical adaptations of microorganisms living in these habitats. This first metatranscriptome analysis of DHAB samples provides significant insights into shifts in metabolic activities of microorganisms as physicochemical conditions change from deep Mediterranean sea water to brine. The analysis of Thetis DHAB interface indicates that sulfate reduction occurs in both the upper (7.0–16.3% salinity) and lower (21.4–27.6%) halocline, but that expression of dissimilatory sulfate reductase is reduced in the more hypersaline lower halocline. High dark-carbon assimilation rates in the upper interface coincided with high abundance of transcripts for ribulose 1,5-bisphosphate carboxylase affiliated to sulfur-oxidizing bacteria. In the lower interface, increased expression of genes associated with methane metabolism and osmoregulation is noted. In addition, in this layer, nitrogenase transcripts affiliated to uncultivated putative methanotrophic archaea were detected, implying nitrogen fixation in this anoxic habitat, and providing evidence of linked carbon, nitrogen and sulfur cycles. PMID:24950109

  18. Ecology of methanogenesis in two hypersaline biocoenoses: Great Salt Lake and a San Francisco Bay saltern

    SciTech Connect

    Paterek, J.R.

    1983-01-01

    Enrichment cultures were prepared from sediment and brine samples from two hypersaline ecosystems, Great Salt Lake in Utah and a solar saltern located in San Francisco Bay. Methane production was greater when enriched with the biopolymer chitin than with cellulose or peptone. Organisms indigenous to hypersaline ecosystems, brine shrimp (Artemia sp.), halobacteria (Halobacterium sp. and Halococcus sp.) and halophilic algae (Dunaliella sp. and others) were cultivated and added to anaerobic and aerobic microcosms prepared with brine and sediment from the ecosystems studied. Methane production and the concentration of the methanogenic precursor, trimethylamine were greatest with brine shrimp as a supplement. Choline produced the highest concentrations of methane in all samples examined. A number of marine-related ecosystems were also examined for their ability to support methanogenesis at various salinities. Methanogenesis occurred at sea water salinity in the majority of samples, and methane production was observed from three sites at salinity found in Great Salt Lake brine. A halophilic methanogenic bacterium species was isolated from both Great Salt Lake and the San Francisco Bay solar saltern sediments. Cells are irregular, nonmotile cocci, approximately 1.0uM in diameter and stain gram negative.

  19. Virus-Host and CRISPR Dynamics in Archaea-Dominated Hypersaline Lake Tyrrell, Victoria, Australia

    DOE PAGESBeta

    Emerson, Joanne B.; Andrade, Karen; Thomas, Brian C.; Norman, Anders; Allen, Eric E.; Heidelberg, Karla B.; Banfield, Jillian F.

    2013-01-01

    The study of natural archaeal assemblages requires community context, namely, a concurrent assessment of the dynamics of archaeal, bacterial, and viral populations. Here, we use filter size-resolved metagenomic analyses to report the dynamics of 101 archaeal and bacterial OTUs and 140 viral populations across 17 samples collected over different timescales from 2007–2010 from Australian hypersaline Lake Tyrrell (LT). All samples were dominated by Archaea (75–95%). Archaeal, bacterial, and viral populations were found to be dynamic on timescales of months to years, and different viral assemblages were present in planktonic, relative to host-associated (active and provirus) size fractions. Analyses of clusteredmore » regularly interspaced short palindromic repeat (CRISPR) regions indicate that both rare and abundant viruses were targeted, primarily by lower abundance hosts. Although very few spacers had hits to the NCBI nr database or to the 140 LT viral populations, 21% had hits to unassembled LT viral concentrate reads. This suggests local adaptation to LT-specific viruses and/or undersampling of haloviral assemblages in public databases, along with successful CRISPR-mediated maintenance of viral populations at abundances low enough to preclude genomic assembly. This is the first metagenomic report evaluating widespread archaeal dynamics at the population level on short timescales in a hypersaline system.« less

  20. PHYLOGENETIC ANALYSIS AND AUTECOLOGY OF SPORE-FORMING BACTERIA FROM HYPERSALINE ENVIRONMENTS.

    PubMed

    Gladka, G V; Romanovskaya, V A; Tashyreva, H O; Tashyrev, O B

    2015-01-01

    Multi-resistant to extreme factors spore-forming bacteria of Bacillus genus are isolated from hypersaline environments of the Crimea (Ukraine) and the Dead Sea (Israel). Phylogenetic analysis showed distinction of dominating extremophilic culturable species in studied regions. In Crimean environments they are B. mojavensis and B. simplex, in the Dead Sea ecosystem--B. subtilis subsp. spizizenii, B. subtilis subsp. subtilis, B. licheniformis and B. simplex. Isolates are simultaneously halotolerant and resistant to UV radiation. Strains isolated from the Dead Sea and the Crimea environments were resistant to UV: LD90 and LD99.99 made 100-170 J/m2 and 750-1500 J/m2 respectively. Spores showed higher UV-resistance (LD99.99-2500 J/m2) than the vegetative cells. However the number of spores made 0.02-0.007% of the whole cell population, and should not significantly affect the UV LD99.99 value. Isolates of both environments were halotolerant in the range of 0.1-10% NaCl and thermotolerant in the range of 20-50 °C, and didn't grow at 15 °C. Survival strategy of spore-forming bacteria from hypersaline environments under high UV radiation level can be performed by spore formation which minimize cell damage as well as efficient DNA-repair systems that remove damages. PMID:26829837

  1. Virus-Host and CRISPR Dynamics in Archaea-Dominated Hypersaline Lake Tyrrell, Victoria, Australia

    PubMed Central

    Emerson, Joanne B.; Andrade, Karen; Thomas, Brian C.; Norman, Anders; Allen, Eric E.; Heidelberg, Karla B.; Banfield, Jillian F.

    2013-01-01

    The study of natural archaeal assemblages requires community context, namely, a concurrent assessment of the dynamics of archaeal, bacterial, and viral populations. Here, we use filter size-resolved metagenomic analyses to report the dynamics of 101 archaeal and bacterial OTUs and 140 viral populations across 17 samples collected over different timescales from 2007–2010 from Australian hypersaline Lake Tyrrell (LT). All samples were dominated by Archaea (75–95%). Archaeal, bacterial, and viral populations were found to be dynamic on timescales of months to years, and different viral assemblages were present in planktonic, relative to host-associated (active and provirus) size fractions. Analyses of clustered regularly interspaced short palindromic repeat (CRISPR) regions indicate that both rare and abundant viruses were targeted, primarily by lower abundance hosts. Although very few spacers had hits to the NCBI nr database or to the 140 LT viral populations, 21% had hits to unassembled LT viral concentrate reads. This suggests local adaptation to LT-specific viruses and/or undersampling of haloviral assemblages in public databases, along with successful CRISPR-mediated maintenance of viral populations at abundances low enough to preclude genomic assembly. This is the first metagenomic report evaluating widespread archaeal dynamics at the population level on short timescales in a hypersaline system. PMID:23853523

  2. Halo(natrono)archaea isolated from hypersaline lakes utilize cellulose and chitin as growth substrates

    PubMed Central

    Sorokin, Dimitry Y.; Toshchakov, Stepan V.; Kolganova, Tatyana V.; Kublanov, Ilya V.

    2015-01-01

    Until recently, extremely halophilic euryarchaeota were considered mostly as aerobic heterotrophs utilizing simple organic compounds as growth substrates. Almost nothing is known on the ability of these prokaryotes to utilize complex polysaccharides, such as cellulose, xylan, and chitin. Although few haloarchaeal cellulases and chitinases were recently characterized, the analysis of currently available haloarchaeal genomes deciphered numerous genes-encoding glycosidases of various families including endoglucanases and chitinases. However, all these haloarchaea were isolated and cultivated on simple substrates and their ability to grow on polysaccharides in situ or in vitro is unknown. This study examines several halo(natrono)archaeal strains from geographically distant hypersaline lakes for the ability to grow on insoluble polymers as a sole growth substrate in salt-saturated mineral media. Some of them belonged to known taxa, while other represented novel phylogenetic lineages within the class Halobacteria. All isolates produced extracellular extremely salt-tolerant cellulases or chitinases, either cell-free or cell-bound. Obtained results demonstrate a presence of diverse populations of haloarchaeal cellulo/chitinotrophs in hypersaline habitats indicating that euryarchaea participate in aerobic mineralization of recalcitrant organic polymers in salt-saturated environments. PMID:26441877

  3. Biofilms constructed for the removal of hydrocarbon pollutants from hypersaline liquids.

    PubMed

    Al-Mailem, D M; Eliyas, M; Khanafer, M; Radwan, S S

    2015-01-01

    Hydrocarbonoclastic biofilms were established on sterile glass plates vertically submerged for 1 month in a hypersaline soil/water suspension containing 0.3% crude oil. The culture-dependent analysis of the microbial community in those biofilms revealed hydrocarbonoclastic species in the magnitude of 10(3) cells cm(-2). Those species belonged to the halophilic bacterial genera Marinobacter, Halomonas, Dietzia, Bacillus, Arhodomonas, Aeromonas and Kocuria as well as to the haloarchaeal genera Haloferax and Halobacterium. Those organisms were not evenly distributed over the biofilm surface area. The culture-independent analysis revealed a different community composition, which was based on four uncultured and four cultured taxa. Depending on the culture conditions and the sort of chemical amendments, the biofilms succeeded in removing in 2 weeks up to about 60-70% of crude oil, pure n-hexadecane and pure phenanthrene in hypersaline pond water samples. The amendment with KCl, MgSO4 and a vitamin mixture composed of thiamin, pyridoxine, vitamin B12, biotin, riboflavin and folic acid was most effective. PMID:25293792

  4. Two Fixed Ratio Dilutions for Soil Salinity Monitoring in Hypersaline Wetlands

    PubMed Central

    Herrero, Juan; Weindorf, David C.; Castañeda, Carmen

    2015-01-01

    Highly soluble salts are undesirable in agriculture because they reduce yields or the quality of most cash crops and can leak to surface or sub-surface waters. In some cases salinity can be associated with unique history, rarity, or special habitats protected by environmental laws. Yet in considering the measurement of soil salinity for long-term monitoring purposes, adequate methods are required. Both saturated paste extracts, intended for agriculture, and direct surface and/or porewater salinity measurement, used in inundated wetlands, are unsuited for hypersaline wetlands that often are only occasionally inundated. For these cases, we propose the use of 1:5 soil/water (weight/weight) extracts as the standard for expressing the electrical conductivity (EC) of such soils and for further salt determinations. We also propose checking for ion-pairing with a 1:10 or more diluted extract in hypersaline soils. As an illustration, we apply the two-dilutions approach to a set of 359 soil samples from saline wetlands ranging in ECe from 2.3 dS m-1 to 183.0 dS m-1. This easy procedure will be useful in survey campaigns and in the monitoring of soil salt content. PMID:26001130

  5. Viruses Occur Incorporated in Biogenic High-Mg Calcite from Hypersaline Microbial Mats.

    PubMed

    De Wit, Rutger; Gautret, Pascale; Bettarel, Yvan; Roques, Cécile; Marlière, Christian; Ramonda, Michel; Nguyen Thanh, Thuy; Tran Quang, Huy; Bouvier, Thierry

    2015-01-01

    Using three different microscopy techniques (epifluorescence, electronic and atomic force microscopy), we showed that high-Mg calcite grains in calcifying microbial mats from the hypersaline lake "La Salada de Chiprana", Spain, contain viruses with a diameter of 50-80 nm. Energy-dispersive X-ray spectrometer analysis revealed that they contain nitrogen and phosphorus in a molar ratio of ~9, which is typical for viruses. Nucleic acid staining revealed that they contain DNA or RNA. As characteristic for hypersaline environments, the concentrations of free and attached viruses were high (>10(10) viruses per g of mat). In addition, we showed that acid treatment (dissolution of calcite) resulted in release of viruses into suspension and estimated that there were ~15 × 10(9) viruses per g of calcite. We suggest that virus-mineral interactions are one of the possible ways for the formation of nano-sized structures often described as "nanobacteria" and that viruses may play a role in initiating calcification. PMID:26115121

  6. Spatial and temporal distribution of archaeal diversity in meromictic, hypersaline Ocnei Lake (Transylvanian Basin, Romania).

    PubMed

    Baricz, Andreea; Coman, Cristian; Andrei, Adrian Stefan; Muntean, Vasile; Keresztes, Zsolt Gyula; Păuşan, Manuela; Alexe, Mircea; Banciu, Horia Leonard

    2014-03-01

    Saline, meromictic lakes with significant depth are usually formed as a result of salt mining activity. Ocnei Lake is one of the largest Transylvanian (Central Romania) neutral, hypersaline lake of man-made origin. We aimed to survey the seasonal dynamics of archaeal diversity in the water column of Ocnei Lake by employing microbiological methods as well as molecular techniques based on the sequence analysis of the 16S rRNA gene. We found that archaeal diversity in the water column increased with depth and salinity, with 8 OTUs being detected in the epilimnion compared to 21 found in the chemocline, and 32 OTUs in the monimolimnion. Down to 3.5 m depth, the archaeal community was markedly dominated by the presence of an unclassified archaeon sharing 93% sequence identity to Halogeometricum spp. At the chemocline, the shift in archaeal community composition was associated with an increase in salinity, the main factor affecting the vertical distribution of archaeal assemblages. It appears that the microoxic and hypersaline monimolimnion is populated by several major haloarchaeal taxa, with minor fluctuations in their relative abundances throughout all seasons. The culturable diversity was reasonably correlated to the dominant OTUs obtained by molecular methods. Our results indicate that Ocnei Lake represents a relatively stable extreme habitat, accommodating a diverse and putatively novel archaeal community, as 30% of OTUs could not be classified at the genus level. PMID:24414798

  7. On the viscosity of natural hyper-saline solutions and its importance: The Dead Sea brines

    NASA Astrophysics Data System (ADS)

    Weisbrod, Noam; Yechieli, Yoseph; Shandalov, Semion; Lensky, Nadav

    2016-01-01

    The relationship between the density, temperature and viscosity of hypersaline solutions, both natural and synthetic, is explored. An empirical equation of the density-viscosity relationship as a function of temperature was developed for the Dead Sea brine and its dilutions. The viscosity levels of the Dead Sea brine (density of 1.24 ṡ 103 kg/m3; viscosity of 3.6 mPa s at 20 °C) and of the more extremely saline natural brine (density of 1.37 ṡ 103 kg/m3) were found to be ∼3 and ∼10 times greater than that of fresh water, respectively. The combined effect of the above changes in viscosity and density on the hydraulic conductivity is reduction by a factor of 3-7. The chemical composition significantly affects the viscosity of brines with similar densities, whereby solutions with a higher Mg/Na ratio have higher viscosity. This explains the extremely high viscosity of the Dead Sea and related Mg-rich brines in comparison with the much lower values of NaCl and KCl brines with similar density. Possible impacts of the results include reduced settling velocity of grains in hypersaline viscous brines and changing hydraulic dynamics at the freshwater-saltwater and the vicinity of sinkholes.

  8. Cytosolic carbonic anhydrase in the Gulf toadfish is important for tolerance to hypersalinity.

    PubMed

    Sattin, G; Mager, E M; Beltramini, M; Grosell, M

    2010-06-01

    Carbonic anhydrase (CA) is a ubiquitous enzyme involved in acid-base regulation and osmoregulation. Many studies have demonstrated a role for this enzyme in fish osmoregulation in seawater as well as freshwater. However, to date CA responses of marine fish exposed to salinities exceeding seawater (approximately 35 ppt) have not been examined. Consequently, the aim of the present study was to examine CA expression and activity in osmoregulatory tissues of the Gulf Toadfish, Opsanus beta, following transfer to 60 ppt. A gene coding, for CAc of 1827 bp with an open reading frame of 260 amino acids was cloned and showed high expression in all intestinal segments and gills. CAc showed higher expression in posterior intestine and rectum than in anterior and mid intestine and in gills of fish exposed to 60 ppt for up to 4 days. The enzymatic activity, in contrast, was higher in all examined tissues two weeks following transfer to 60 ppt. Comparing early expression and later activity levels of acclimated fish reveals a very different response to hypersalinity among tissues. Results highlight a key role of CAc in osmoregulation especially in distal regions of the intestine; moreover, CAc play a role in the gill in hypersaline environments possibly supporting elevated branchial acid extrusion seen under such conditions. PMID:20152924

  9. Determination of Rare Earth Elements in Hypersaline Solutions Using Low-Volume, Liquid-Liquid Extraction.

    PubMed

    Noack, Clinton W; Dzombak, David A; Karamalidis, Athanasios K

    2015-08-18

    Complex, hypersaline brines-including those coproduced with oil and gas, rejected from desalination technologies, or used as working fluids for geothermal electricity generation-could contain critical materials such as the rare earth elements (REE) in valuable concentrations. Accurate quantitation of these analytes in complex, aqueous matrices is necessary for evaluation and implementation of systems aimed at recovering those critical materials. However, most analytical methods for measuring trace metals have not been validated for highly saline and/or chemically complex brines. Here we modified and optimized previously published liquid-liquid extraction (LLE) techniques using bis(2-ethylhexyl) phosphate as the extractant in a heptane diluent, and studied its efficacy for REE recovery as a function of three primary variables: background salinity (as NaCl), concentration of a competing species (here Fe), and concentration of dissolved organic carbon (DOC). Results showed that the modified LLE was robust to a range of salinity, Fe, and DOC concentrations studied as well as constant, elevated Ba concentrations. With proper characterization of the natural samples of interest, this method could be deployed for accurate analysis of REE in small volumes of hyper-saline and chemically complex brines. PMID:25920439

  10. Multi-temporal water extent analysis of a hypersaline playa lake using Landsat Imagery

    NASA Astrophysics Data System (ADS)

    Kilic, Ecenur; Kamil Yilmaz, Koray; Lutfi Suzen, Mehmet

    2016-04-01

    Distinguishing inland water bodies from satellite imagery has always been one of the main practices of remote sensing. In some cases this differentiation can directly be obtained by visual interpretation. However, in case of hyper-saline playa lakes, presence of high albedo salt crust in the lake bed hampers visual interpretation and requires further attention. Lake Tuz is a hypersaline playa lake which is ranked as the second largest lake in Turkey. Spatio-temporal changes in lake water extent are important both economically and hydrologically including salt production, lake water balance, drought and over-exploitation issues. This study investigates the spatiotemporal changes in Lake Tuz water extent during the last decade using single-band thresholding and multi-band indices extracted from the multi-temporal Landsat 5 TM and Landsat 7 ETM+ images. The applicability of different satellite-derived indices including Normalized Difference Water Index (NDWI), Modified NDWI (MNDWI), Automated Water Extraction Index (AWEI) and Tasseled Cap Wetness (TCw) were investigated for the extraction of lake water extent from Landsat imagery. Our analysis indicated that, overall, NDWI is superior to other tested indices in separating wet/dry pixels over the lake bottom covered with salt crust. Using a NDWI thresholding procedure, the annual and seasonal variation in the Lake Tuz water extent were determined and further linked to hydro-meteorological variables such as precipitation.

  11. Extremophile microbiomes in acidic and hypersaline river sediments of Western Australia.

    PubMed

    Lu, Shipeng; Peiffer, Stefan; Lazar, Cassandre Sara; Oldham, Carolyn; Neu, Thomas R; Ciobota, Valerian; Näb, Olga; Lillicrap, Adam; Rösch, Petra; Popp, Jürgen; Küsel, Kirsten

    2016-02-01

    We investigated the microbial community compositions in two sediment samples from the acidic (pH ∼3) and hypersaline (>4.5% NaCl) surface waters, which are widespread in Western Australia. In West Dalyup River, large amounts of NaCl, Fe(II) and sulfate are brought by the groundwater into the surface run-off. The presence of K-jarosite and schwertmannite minerals in the river sediments suggested the occurrence of microbial Fe(II) oxidation because chemical oxidation is greatly reduced at low pH. 16S rRNA gene diversity analyses revealed that sequences affiliated with an uncultured archaeal lineage named Aplasma, which has the genomic potential for Fe(II) oxidation, were dominant in both sediment samples. The acidophilic heterotrophs Acidiphilium and Acidocella were identified as the dominant bacterial groups. Acidiphilium strain AusYE3-1 obtained from the river sediment tolerated up to 6% NaCl at pH 3 under oxic conditions and cells of strain AusYE3-1 reduced the effects of high salt content by forming filamentous structure clumping as aggregates. Neither growth nor Fe(III) reduction by strain AusYE3-1 was observed in anoxic salt-containing medium. The detection of Aplasma group as potential Fe(II) oxidizers and the inhibited Fe(III)-reducing capacity of Acidiphilium contributes to our understanding of the microbial ecology of acidic hypersaline environments. PMID:26524974

  12. Virus-host and CRISPR dynamics in Archaea-dominated hypersaline Lake Tyrrell, Victoria, Australia.

    PubMed

    Emerson, Joanne B; Andrade, Karen; Thomas, Brian C; Norman, Anders; Allen, Eric E; Heidelberg, Karla B; Banfield, Jillian F

    2013-01-01

    The study of natural archaeal assemblages requires community context, namely, a concurrent assessment of the dynamics of archaeal, bacterial, and viral populations. Here, we use filter size-resolved metagenomic analyses to report the dynamics of 101 archaeal and bacterial OTUs and 140 viral populations across 17 samples collected over different timescales from 2007-2010 from Australian hypersaline Lake Tyrrell (LT). All samples were dominated by Archaea (75-95%). Archaeal, bacterial, and viral populations were found to be dynamic on timescales of months to years, and different viral assemblages were present in planktonic, relative to host-associated (active and provirus) size fractions. Analyses of clustered regularly interspaced short palindromic repeat (CRISPR) regions indicate that both rare and abundant viruses were targeted, primarily by lower abundance hosts. Although very few spacers had hits to the NCBI nr database or to the 140 LT viral populations, 21% had hits to unassembled LT viral concentrate reads. This suggests local adaptation to LT-specific viruses and/or undersampling of haloviral assemblages in public databases, along with successful CRISPR-mediated maintenance of viral populations at abundances low enough to preclude genomic assembly. This is the first metagenomic report evaluating widespread archaeal dynamics at the population level on short timescales in a hypersaline system. PMID:23853523

  13. Viruses Occur Incorporated in Biogenic High-Mg Calcite from Hypersaline Microbial Mats

    PubMed Central

    De Wit, Rutger; Gautret, Pascale; Bettarel, Yvan; Roques, Cécile; Marlière, Christian; Ramonda, Michel; Nguyen Thanh, Thuy; Tran Quang, Huy; Bouvier, Thierry

    2015-01-01

    Using three different microscopy techniques (epifluorescence, electronic and atomic force microscopy), we showed that high-Mg calcite grains in calcifying microbial mats from the hypersaline lake “La Salada de Chiprana”, Spain, contain viruses with a diameter of 50–80 nm. Energy-dispersive X-ray spectrometer analysis revealed that they contain nitrogen and phosphorus in a molar ratio of ~9, which is typical for viruses. Nucleic acid staining revealed that they contain DNA or RNA. As characteristic for hypersaline environments, the concentrations of free and attached viruses were high (>1010 viruses per g of mat). In addition, we showed that acid treatment (dissolution of calcite) resulted in release of viruses into suspension and estimated that there were ~15 × 109 viruses per g of calcite. We suggest that virus-mineral interactions are one of the possible ways for the formation of nano-sized structures often described as “nanobacteria” and that viruses may play a role in initiating calcification. PMID:26115121

  14. Alkaline Phosphatase in Stem Cells

    PubMed Central

    Štefková, Kateřina; Procházková, Jiřina; Pacherník, Jiří

    2015-01-01

    Alkaline phosphatase is an enzyme commonly expressed in almost all living organisms. In humans and other mammals, determinations of the expression and activity of alkaline phosphatase have frequently been used for cell determination in developmental studies and/or within clinical trials. Alkaline phosphatase also seems to be one of the key markers in the identification of pluripotent embryonic stem as well as related cells. However, alkaline phosphatases exist in some isoenzymes and isoforms, which have tissue specific expressions and functions. Here, the role of alkaline phosphatase as a stem cell marker is discussed in detail. First, we briefly summarize contemporary knowledge of mammalian alkaline phosphatases in general. Second, we focus on the known facts of its role in and potential significance for the identification of stem cells. PMID:25767512

  15. Magmatic gas emissions at Holocene volcanic features near Mono Lake, California, and their relation to regional magmatism

    NASA Astrophysics Data System (ADS)

    Bergfeld, Deborah; Evans, William C.; Howle, James F.; Hunt, Andrew G.

    2015-02-01

    Silicic lavas have erupted repeatedly in the Mono Basin over the past few thousand years, forming the massive domes and coulees of the Mono Craters chain and the smaller island vents in Mono Lake. We report here on the first systematic study of magmatic CO2 emissions from these features, conducted during 2007-2010. Most notably, a known locus of weak steam venting on the summit of North Coulee is actually enclosed in a large area (~ 0.25 km2) of diffuse gas discharge that emits 10-14 t/d of CO2, mostly at ambient temperature. Subsurface gases sampled here are heavily air-contaminated, but after standard corrections are applied, show average δ13C-CO2 of - 4.72‰, 3He/4He of 5.89RA, and CO2/3He of 0.77 × 1010, very similar to the values in fumarolic gas from Mammoth Mountain and the Long Valley Caldera immediately to the south of the basin. If these values also characterize the magmatic gas source at Mono Lake, where CO2 is captured by the alkaline lake water, a magmatic CO2 upflow beneath the lake of ~ 4 t/d can be inferred. Groundwater discharge from the Mono Craters area transports ~ 13 t/d of 14C-dead CO2 as free gas and dissolved carbonate species, and adding in this component brings the estimated total magmatic CO2 output to 29 t/d for the two silicic systems in the Mono Basin. If these emissions reflect intrusion and degassing of underlying basalt with 0.5 wt.% CO2, a modest intrusion rate of 0.00075 km3/yr is indicated. Much higher intrusion rates are required to account for CO2 emissions from Mammoth Mountain and the West Moat of the Long Valley Caldera.

  16. Alkaline fuel cells applications

    NASA Astrophysics Data System (ADS)

    Kordesch, Karl; Hacker, Viktor; Gsellmann, Josef; Cifrain, Martin; Faleschini, Gottfried; Enzinger, Peter; Fankhauser, Robert; Ortner, Markus; Muhr, Michael; Aronson, Robert R.

    On the world-wide automobile market technical developments are increasingly determined by the dramatic restriction on emissions as well as the regimentation of fuel consumption by legislation. Therefore there is an increasing chance of a completely new technology breakthrough if it offers new opportunities, meeting the requirements of resource preservation and emission restrictions. Fuel cell technology offers the possibility to excel in today's motive power techniques in terms of environmental compatibility, consumer's profit, costs of maintenance and efficiency. The key question is economy. This will be decided by the costs of fuel cell systems if they are to be used as power generators for future electric vehicles. The alkaline hydrogen-air fuel cell system with circulating KOH electrolyte and low-cost catalysed carbon electrodes could be a promising alternative. Based on the experiences of Kordesch [K. Kordesch, Brennstoffbatterien, Springer, Wien, 1984, ISBN 3-387-81819-7; K. Kordesch, City car with H 2-air fuel cell and lead-battery, SAE Paper No. 719015, 6th IECEC, 1971], who operated a city car hybrid vehicle on public roads for 3 years in the early 1970s, improved air electrodes plus new variations of the bipolar stack assembly developed in Graz are investigated. Primary fuel choice will be a major issue until such time as cost-effective, on-board hydrogen storage is developed. Ammonia is an interesting option. The whole system, ammonia dissociator plus alkaline fuel cell (AFC), is characterised by a simple design and high efficiency.

  17. Organic geochemical studies of a Messinian evaporitic basin, northern Apennines (Italy) I: Hydrocarbon biological markers for a hypersaline environment

    NASA Astrophysics Data System (ADS)

    Ten Haven, H. L.; De Leeuw, J. W.; Schenck, P. A.

    1985-10-01

    This paper describes the occurrence and significance of hydrocarbons present in two bituminous marl layers and one distinct gypsum layer from a Messinian sedimentary basin, where hypersaline conditions prevailed. Several new compounds were detected and tentatively identified: of these 20R and 20S 4α, 24-dimethyl-5α(H),14β(H),17β(H) and 20R and 20S 4β,24-dimethyI-5α(H),14β(H),17β(H) cholestanes; 4-methylspirosterenes; 4,4-dimethyl-5α(H),14β(H),17β(H) pregnanes and homopregnanes are discussed in this paper. Several of these compounds might be considered as biological markers for a (hyper)saline environment. The short side chain 4-desmethylsteranes, 5α(H),14β(H),17β(H), 5α(H),14β(H),17α(H) and 5α(H),14α(H), 17α(H) pregnanes and homopregnanes, are the most abundant compounds in the extract from the gypsum sample. It is suggested that in this case these compounds do not reflect the stage of diagenesis but are related to certain organisms exclusively occurring in hypersaline environments. In addition the very low pristane/phytane ratio, often considered as an indicator for anoxicity, could also be interpreted as a useful indicator for hypersalinity.

  18. Silica in alkaline brines

    USGS Publications Warehouse

    Jones, B.F.; Rettig, S.L.; Eugster, H.P.

    1967-01-01

    Analysis of sodium carbonate-bicarbonate brines from closed basins in volcanic terranes of Oregon and Kenya reveals silica contents of up to 2700 parts per million at pH's higher than 10. These high concentrations of SiO 2 can be attributed to reaction of waters with silicates, and subsequent evaporative concentration accompanied by a rise in pH. Supersaturation with respect to amorphous silica may occur and persist for brines that are out of contact with silicate muds and undersaturated with respect to trona; correlation of SiO2 with concentration of Na and total CO2 support this interpretation. Addition of moredilute waters to alkaline brines may lower the pH and cause inorganic precipitation of substantial amounts of silica.

  19. Bifunctional alkaline oxygen electrodes

    NASA Technical Reports Server (NTRS)

    Swette, L.; Kackley, N.; Mccatty, S. A.

    1991-01-01

    The authors describe the identification and testing of electrocatalysts and supports for the positive electrode of moderate-temperature, single-unit, rechargeable alkaline fuel cells. Recent work on Na(x)Pt3O4, a potential bifunctional catalyst, is described, as well as the application of novel approaches to the development of more efficient bifunctional electrode structures. The three dual-character electrodes considered here showed similar superior performance; the Pt/RhO2 and Rh/RhO2 electrodes showed slightly better performance than the Pt/IrO2 electrode. It is concluded that Na(x)Pt3O4 continues to be a promising bifunctional oxygen electrode catalyst but requires further investigation and development.

  20. Diversity and Distribution in Hypersaline Microbial Mats of Bacteria Related to Chloroflexus spp.

    PubMed Central

    Nübel, Ulrich; Bateson, Mary M.; Madigan, Michael T.; Kühl, Michael; Ward, David M.

    2001-01-01

    Filamentous bacteria containing bacteriochlorophylls c and a were enriched from hypersaline microbial mats. Based on phylogenetic analyses of 16S rRNA gene sequences, these organisms form a previously undescribed lineage distantly related to Chloroflexus spp. We developed and tested a set of PCR primers for the specific amplification of 16S rRNA genes from filamentous phototrophic bacteria within the kingdom of “green nonsulfur bacteria.” PCR products recovered from microbial mats in a saltern in Guerrero Negro, Mexico, were subjected to cloning or denaturing gradient gel electrophoresis and then sequenced. We found evidence of a high diversity of bacteria related to Chloroflexus which exhibit different distributions along a gradient of salinity from 5.5 to 16%. PMID:11526049

  1. SAR Imagery Applied to the Monitoring of Hyper-Saline Deposits: Death Valley Example (CA)

    NASA Technical Reports Server (NTRS)

    Lasne, Yannick; Paillou, Philippe; Freeman, Anthony; Chapman, Bruce

    2009-01-01

    The present study aims at understanding the influence of salinity on the dielectric constant of soils and then on the backscattering coeff cients recorded by airborne/spaceborne SAR systems. Based on dielectric measurements performed over hyper-saline deposits in Death Valley (CA), as well as laboratory electromagnetic characterization of salts and water mixtures, we used the dielectric constants as input parameters of analytical IEM simulations to model both the amplitude and phase behaviors of SAR signal at C, and L-bands. Our analytical simulations allow to reproduce specif c copolar signatures recorded in SAR data, corresponding to the Cottonball Basin saltpan. We also propose the copolar backscattering ratio and phase difference as indicators of moistened and salt-affected soils. More precisely, we show that these copolar indicators should allow to monitor the seasonal variations of the dielectric properties of saline deposits.

  2. Use of an Acoustic Doppler Current Profiler (ADCP) to Measure Hypersaline Bidirectional Discharge

    USGS Publications Warehouse

    Johnson, K.K.; Loving, B.L.

    2002-01-01

    The U.S. Geological Survey measures the exchange of flow between the north and south parts of Great Salt Lake, Utah, as part of a monitoring program. Turbidity and bidirectional flow through the breach in the causeway that divides the lake into two parts makes it difficult to measure discharge with conventional streamflow techniques. An acoustic Doppler current profiler (ADCP) can be used to more accurately define the angles of flow and the location of the interface between the layers of flow. Because of the high salinity levels measured in Great Salt Lake (60-280 parts per thousand), special methods had to be developed to adjust ADCP-computed discharges for the increased speed of sound in hypersaline waters and for water entrained at the interface between flow layers.

  3. Temporal stability and origin of chemoclines in the deep hypersaline anoxic Urania basin

    NASA Astrophysics Data System (ADS)

    Goldhammer, Tobias; Schwärzle, Andreas; Aiello, Ivano W.; Zabel, Matthias

    2015-06-01

    Submarine brine lakes feature sharp and persistent concentration gradients between seawater and brine, though these should be smoothed out by free diffusion in open ocean settings. The anoxic Urania basin of the eastern Mediterranean contains an ultrasulfidic, hypersaline brine of Messinian origin above a thick layer of suspended sediments. With a dual modeling approach we reconstruct its contemporary stratification by geochemical solute transport fundamentals and show that thermal convection is required to maintain mixing in the brine and mud layer. The origin of the Urania basin stratification was dated to 1650 years B.P., which may be linked to a major earthquake in the region. The persistence of the chemoclines may be key to the development of diverse and specialized microbial communities. Ongoing thermal convection in the fluid mud layer may have important yet unresolved consequences for sedimentological and geochemical processes, also in similar environments.

  4. Phialosimplex salinarum, a new species of Eurotiomycetes from a hypersaline habitat.

    PubMed

    Greiner, Katrin; Peršoh, Derek; Weig, Alfons; Rambold, Gerhard

    2014-12-01

    Salt mines represent an extreme environment with hypersaline conditions, complete darkness, and low nutrient availability. The diversity of filamentous fungi in such habitats is largely unknown. Eight strains of an unknown fungus were isolated from water samples of the salt mine in Berchtesgaden (Bavaria, Germany). They could be assigned to the ascomycete genus Phialosimplex, based on their common characteristics of producing conidia in chains or in heads on single phialides. Species of this genus are hitherto known to cause mycoses in dogs and have been found in mummies. Using molecular and morphological methods, the isolates are established as a new species, Phialosimplex salinarum sp. nov. Basipetospora halophila is also transferred to Phialosimplex as P. halophila comb. nov. PMID:25734026

  5. Microbial Species Richness and Metabolic Activities in Hypersaline Microbial Mats: Insight into Biosignature Formation Through Lithification

    NASA Astrophysics Data System (ADS)

    Baumgartner, Laura K.; Dupraz, Christophe; Buckley, Daniel H.; Spear, John R.; Pace, Norman R.; Visscher, Pieter T.

    2009-11-01

    Microbial mats in the hypersaline lake of Salt Pan, Eleuthera, Bahamas, display a gradient of lithification along a transect from the center to the shore of the lake. These mats exist under similar geochemical conditions, with light quantity and quality as the sole major environmental difference. Therefore, we hypothesized that the microbial community may be driving the differences in lithification and, by extension, mineral biosignature formation. The lithifying and non-lithifying mat communities were compared (via 16S rRNA gene sequencing, 485 and 464 sequences, respectively) over both temporal and spatial scales. Seven bacterial groups dominated in all the microbial mat libraries: bacteriodetes, alphaproteobacteria, deltaproetobacteria, chloroflexi, spirochaetes, cyanobacteria, and planctomycetes. The mat communities were all significantly different over space, time, and lithification state. Species richness is significantly higher in the non-lithifying mats, potentially due to differences in mat structure and activity. This increased richness may impact lithification and, hence, biosignature production.

  6. Nitrate attenuation potential of hypersaline lake sediments in central Spain: flow-through and batch experiments.

    PubMed

    Carrey, R; Rodríguez-Escales, P; Otero, N; Ayora, C; Soler, A; Gómez-Alday, J J

    2014-08-01

    Complex lacustrine systems, such as hypersaline lakes located in endorheic basins, are exposed to nitrate (NO3(-)) pollution. An excellent example of these lakes is the hypersaline lake located in the Pétrola basin (central Spain), where the lake acts as a sink for NO3(-) from agricultural activities and from sewage from the surrounding area. To better understand the role of the organic carbon (Corg) deposited in the bottom sediment in promoting denitrification, a four-stage flow-through experiment (FTR) and batch experiments using lake bottom sediment were performed. The chemical, multi-isotopic and kinetic characterization of the outflow showed that the intrinsic NO3(-) attenuation potential of the lake bottom sediment was able to remove 95% of the NO3(-) input over 296days under different flow conditions. The NO3(-) attenuation was mainly linked with denitrification but some dissimilatory nitrate reduction to ammonium was observed at early days favored by the high C/N ratio and salinity. Sulfate reduction could be neither confirmed nor discarded during the experiments because the sediment leaching masked the chemical and isotopic signatures of this reaction. The average nitrogen reduction rate (NRR) obtained was 1.25mmold(-1)kg(-1) and was independent of the flow rate employed. The amount of reactive Corg from the bottom sediment consumed during denitrification was 28.8mmol, representing approximately 10% of the total Corg of the sediment (1.2%). Denitrification was produced coupled with an increase in the isotopic composition of both δ(15)N and δ(18)O. The isotopic fractionations (ε of (15)N-NO3(-) and (18)O-NO3(-)) produced during denitrification were calculated using batch and vertical profile samples. The results were -14.7‰ for εN and -14.5‰ for εO. PMID:25041733

  7. Recent studies in microbial degradation of petroleum hydrocarbons in hypersaline environments

    PubMed Central

    Fathepure, Babu Z.

    2014-01-01

    Many hypersaline environments are often contaminated with petroleum compounds. Among these, oil and natural gas production sites all over the world and hundreds of kilometers of coastlines in the more arid regions of Gulf countries are of major concern due to the extent and magnitude of contamination. Because conventional microbiological processes do not function well at elevated salinities, bioremediation of hypersaline environments can only be accomplished using high salt-tolerant microorganisms capable of degrading petroleum compounds. In the last two decades, there have been many reports on the biodegradation of hydrocarbons in moderate to high salinity environments. Numerous microorganisms belonging to the domain Bacteria and Archaea have been isolated and their phylogeny and metabolic capacity to degrade a variety of aliphatic and aromatic hydrocarbons in varying salinities have been demonstrated. This article focuses on our growing understanding of bacteria and archaea responsible for the degradation of hydrocarbons under aerobic conditions in moderate to high salinity conditions. Even though organisms belonging to various genera have been shown to degrade hydrocarbons, members of the genera Halomonas Alcanivorax, Marinobacter, Haloferax, Haloarcula, and Halobacterium dominate the published literature. Despite rapid advances in understanding microbial taxa that degrade hydrocarbons under aerobic conditions, not much is known about organisms that carry out similar processes in anaerobic conditions. Also, information on molecular mechanisms and pathways of hydrocarbon degradation in high salinity is scarce and only recently there have been a few reports describing genes, enzymes and breakdown steps for some hydrocarbons. These limited studies have clearly revealed that degradation of oxygenated and non-oxygenated hydrocarbons by halophilic and halotolerant microorganisms occur by pathways similar to those found in non-halophiles. PMID:24795705

  8. Metagenomic and lipid analyses reveal a diel cycle in a hypersaline microbial ecosystem.

    PubMed

    Andrade, Karen; Logemann, Jörn; Heidelberg, Karla B; Emerson, Joanne B; Comolli, Luis R; Hug, Laura A; Probst, Alexander J; Keillar, Angus; Thomas, Brian C; Miller, Christopher S; Allen, Eric E; Moreau, John W; Brocks, Jochen J; Banfield, Jillian F

    2015-12-01

    Marine microbial communities experience daily fluctuations in light and temperature that can have important ramifications for carbon and nutrient cycling. Elucidation of such short time scale community-wide dynamics is hindered by system complexity. Hypersaline aquatic environments have lower species richness than marine environments and can be well-defined spatially, hence they provide a model system for diel cycle analysis. We conducted a 3-day time series experiment in a well-defined pool in hypersaline Lake Tyrrell, Australia. Microbial communities were tracked by combining cultivation-independent lipidomic, metagenomic and microscopy methods. The ratio of total bacterial to archaeal core lipids in the planktonic community increased by up to 58% during daylight hours and decreased by up to 32% overnight. However, total organism abundances remained relatively consistent over 3 days. Metagenomic analysis of the planktonic community composition, resolved at the genome level, showed dominance by Haloquadratum species and six uncultured members of the Halobacteriaceae. The post 0.8 μm filtrate contained six different nanohaloarchaeal types, three of which have not been identified previously, and cryo-transmission electron microscopy imaging confirmed the presence of small cells. Notably, these nano-sized archaea showed a strong diel cycle, with a pronounced increase in relative abundance over the night periods. We detected no eukaryotic algae or other photosynthetic primary producers, suggesting that carbon resources may derive from patchily distributed microbial mats at the sediment-water interface or from surrounding land. Results show the operation of a strong community-level diel cycle, probably driven by interconnected temperature, light abundance, dissolved oxygen concentration and nutrient flux effects. PMID:25918833

  9. Paracellular pathway remodeling enhances sodium secretion by teleost fish in hypersaline environments.

    PubMed

    Cozzi, Regina R F; Robertson, George N; Spieker, Melanie; Claus, Lauren N; Zaparilla, Gabriella M M; Garrow, Kelly L; Marshall, William S

    2015-04-15

    In vertebrate salt-secreting epithelia, Na(+) moves passively down an electrochemical gradient via a paracellular pathway. We assessed how this pathway is modified to allow Na(+) secretion in hypersaline environments. Mummichogs (Fundulus heteroclitus) acclimated to hypersaline [2× seawater (2SW), 64‰] for 30 days developed invasive projections of accessory cells with an increased area of tight junctions, detected by punctate distribution of CFTR (cystic fibrosis transmembrane conductance regulator) immunofluorescence and transmission electron miscroscopy of the opercular epithelia, which form a gill-like tissue rich in ionocytes. Distribution of CFTR was not explained by membrane raft organization, because chlorpromazine (50 μmol l(-1)) and filipin (1.5 μmol l(-1)) did not affect opercular epithelia electrophysiology. Isolated opercular epithelia bathed in SW on the mucosal side had a transepithelial potential (Vt) of +40.1±0.9 mV (N=24), sufficient for passive Na(+) secretion (Nernst equilibrium voltage≡ENa=+24.11 mV). Opercular epithelia from fish acclimated to 2SW and bathed in 2SW had higher Vt of +45.1±1.2 mV (N=24), sufficient for passive Na(+) secretion (ENa=+40.74 mV), but with diminished net driving force. Bumetanide block of Cl(-) secretion reduced Vt by 45% and 29% in SW and 2SW, respectively, a decrease in the driving force for Na(+) extrusion. Estimates of shunt conductance from epithelial conductance (Gt) versus short-circuit current (Isc) plots (extrapolation to zero Isc) suggested a reduction in total epithelial shunt conductance in 2SW-acclimated fish. In contrast, the morphological elaboration of tight junctions, leading to an increase in accessory-cell-ionocyte contact points, suggests an increase in local paracellular conductance, compensating for the diminished net driving force for Na(+) and allowing salt secretion, even in extreme salinities. PMID:25750413

  10. Phylogenetic analysis of the microbial community in hypersaline petroleum produced water from the Campos Basin.

    PubMed

    Piubeli, Francine; Grossman, Matthew J; Fantinatti-Garboggini, Fabiana; Durrant, Lucia R

    2014-10-01

    In this work the archaea and eubacteria community of a hypersaline produced water from the Campos Basin that had been transported and discharged to an onshore storage facility was evaluated by 16S recombinant RNA (rRNA) gene sequence analysis. The produced water had a hypersaline salt content of 10 (w/v), had a carbon oxygen demand (COD) of 4,300 mg/l and contains phenol and other aromatic compounds. The high salt and COD content and the presence of toxic phenolic compounds present a problem for conventional discharge to open seawater. In previous studies, we demonstrated that the COD and phenolic content could be largely removed under aerobic conditions, without dilution, by either addition of phenol degrading Haloarchaea or the addition of nutrients alone. In this study our goal was to characterize the microbial community to gain further insight into the persistence of reservoir community members in the produced water and the potential for bioremediation of COD and toxic contaminants. Members of the archaea community were consistent with previously identified communities from mesothermic reservoirs. All identified archaea were located within the phylum Euryarchaeota, with 98 % being identified as methanogens while 2 % could not be affiliated with any known genus. Of the identified archaea, 37 % were identified as members of the strictly carbon-dioxide-reducing genus Methanoplanus and 59 % as members of the acetoclastic genus Methanosaeta. No Haloarchaea were detected, consistent with the need to add these organisms for COD and aromatic removal. Marinobacter and Halomonas dominated the eubacterial community. The presence of these genera is consistent with the ability to stimulate COD and aromatic removal with nutrient addition. In addition, anaerobic members of the phyla Thermotogae, Firmicutes, and unclassified eubacteria were identified and may represent reservoir organisms associated with the conversion hydrocarbons to methane. PMID:24920265

  11. Recent studies in microbial degradation of petroleum hydrocarbons in hypersaline environments.

    PubMed

    Fathepure, Babu Z

    2014-01-01

    Many hypersaline environments are often contaminated with petroleum compounds. Among these, oil and natural gas production sites all over the world and hundreds of kilometers of coastlines in the more arid regions of Gulf countries are of major concern due to the extent and magnitude of contamination. Because conventional microbiological processes do not function well at elevated salinities, bioremediation of hypersaline environments can only be accomplished using high salt-tolerant microorganisms capable of degrading petroleum compounds. In the last two decades, there have been many reports on the biodegradation of hydrocarbons in moderate to high salinity environments. Numerous microorganisms belonging to the domain Bacteria and Archaea have been isolated and their phylogeny and metabolic capacity to degrade a variety of aliphatic and aromatic hydrocarbons in varying salinities have been demonstrated. This article focuses on our growing understanding of bacteria and archaea responsible for the degradation of hydrocarbons under aerobic conditions in moderate to high salinity conditions. Even though organisms belonging to various genera have been shown to degrade hydrocarbons, members of the genera Halomonas Alcanivorax, Marinobacter, Haloferax, Haloarcula, and Halobacterium dominate the published literature. Despite rapid advances in understanding microbial taxa that degrade hydrocarbons under aerobic conditions, not much is known about organisms that carry out similar processes in anaerobic conditions. Also, information on molecular mechanisms and pathways of hydrocarbon degradation in high salinity is scarce and only recently there have been a few reports describing genes, enzymes and breakdown steps for some hydrocarbons. These limited studies have clearly revealed that degradation of oxygenated and non-oxygenated hydrocarbons by halophilic and halotolerant microorganisms occur by pathways similar to those found in non-halophiles. PMID:24795705

  12. Microbial Communities in the Chemocline of a Hypersaline Deep-Sea Basin (Urania Basin, Mediterranean Sea)

    PubMed Central

    Sass, Andrea M.; Sass, Henrik; Coolen, Marco J. L.; Cypionka, Heribert; Overmann, Jörg

    2001-01-01

    The Urania basin is a hypersaline sulfidic brine lake at the bottom of the eastern Mediterranean Sea. Since this basin is located at a depth of ∼3,500 m below the sea surface, it receives only a small amount of phytoplankton organic carbon. In the present study, the bacterial assemblages at the interface between the hypersaline brine and the overlaying seawater were investigated. The sulfide concentration increased from 0 to 10 mM within a vertical interval of 5 m across the interface. Within this chemocline, the total bacterial cell counts and the exoenzyme activities were elevated. Employing 11 cultivation methods, we isolated a total of 70 bacterial strains. The 16S ribosomal DNA sequences of 32 of the strains were identical to environmental sequences detected in the chemocline by culture-independent molecular methods. These strains were identified as flavobacteria, Alteromonas macleodii, and Halomonas aquamarina. All 70 strains could grow chemoorganoheterotrophically under oxic conditions. Sixty-six strains grew on peptone, casein hydrolysate, and yeast extract, whereas only 15 strains did not utilize polymeric carbohydrates. Twenty-one of the isolates could grow both chemoorganotrophically and chemolithotrophically. While the most probable numbers in most cases ranged between 0.006 and 4.3% of the total cell counts, an unsually high value of 54% was determined above the chemocline with media containing amino acids as the carbon and energy source. Our results indicate that culturable bacteria thriving at the oxic-anoxic interface of the Urania basin differ considerably from the chemolithoautotrophic bacteria typical of other chemocline habitats. PMID:11722884

  13. On mono-W signatures in spin-1 simplified models

    NASA Astrophysics Data System (ADS)

    Haisch, Ulrich; Kahlhoefer, Felix; Tait, Tim M. P.

    2016-09-01

    The potential sensitivity to isospin-breaking effects makes LHC searches for mono-W signatures promising probes of the coupling structure between the Standard Model and dark matter. It has been shown, however, that the strong sensitivity of the mono-W channel to the relative magnitude and sign of the up-type and down-type quark couplings to dark matter is an artifact of unitarity violation. We provide three different solutions to this mono-W problem in the context of spin-1 simplified models and briefly discuss the impact that our findings have on the prospects of mono-W searches at future LHC runs.

  14. Assembly-driven metagenomics of a hypersaline microbial ecosystem (2013 DOE JGI Genomics of Energy and Environment 8th Annual User Meeting)

    SciTech Connect

    Allen, Eric

    2013-03-01

    Eric Allen of Scripps and UC San Diego on "Assembly-driven metagenomics of a hypersaline microbial ecosystem" at the 8th Annual Genomics of Energy & Environment Meeting on March 27, 2013 in Walnut Creek, Calif.

  15. Modulators of intestinal alkaline phosphatase.

    PubMed

    Bobkova, Ekaterina V; Kiffer-Moreira, Tina; Sergienko, Eduard A

    2013-01-01

    Small molecule modulators of phosphatases can lead to clinically useful drugs and serve as invaluable tools to study functional roles of various phosphatases in vivo. Here, we describe lead discovery strategies for identification of inhibitors and activators of intestinal alkaline phosphatases. To identify isozyme-selective inhibitors and activators of the human and mouse intestinal alkaline phosphatases, ultrahigh throughput chemiluminescent assays, utilizing CDP-Star as a substrate, were developed for murine intestinal alkaline phosphatase (mIAP), human intestinal alkaline phosphatase (hIAP), human placental alkaline phosphatase (PLAP), and human tissue-nonspecific alkaline phosphatase (TNAP) isozymes. Using these 1,536-well assays, concurrent HTS screens of the MLSMR library of 323,000 compounds were conducted for human and mouse IAP isozymes monitoring both inhibition and activation. This parallel screening approach led to identification of a novel inhibitory scaffold selective for murine intestinal alkaline phosphatase. SAR efforts based on parallel testing of analogs against different AP isozymes generated a potent inhibitor of the murine IAP with IC50 of 540 nM, at least 65-fold selectivity against human TNAP, and >185 selectivity against human PLAP. PMID:23860652

  16. Alkaline battery, separator therefore

    NASA Technical Reports Server (NTRS)

    Schmidt, George F. (Inventor)

    1980-01-01

    An improved battery separator for alkaline battery cells has low resistance to electrolyte ion transfer and high resistance to electrode ion transfer. The separator is formed by applying an improved coating to an electrolyte absorber. The absorber, preferably, is a flexible, fibrous, and porous substrate that is resistant to strong alkali and oxidation. The coating composition includes an admixture of a polymeric binder, a hydrolyzable polymeric ester and inert fillers. The coating composition is substantially free of reactive fillers and plasticizers commonly employed as porosity promoting agents in separator coatings. When the separator is immersed in electrolyte, the polymeric ester of the film coating reacts with the electrolyte forming a salt and an alcohol. The alcohol goes into solution with the electrolyte while the salt imbibes electrolyte into the coating composition. When the salt is formed, it expands the polymeric chains of the binder to provide a film coating substantially permeable to electrolyte ion transfer but relatively impermeable to electrode ion transfer during use.

  17. Evaluation of Alkaline Cleaner Materials

    NASA Technical Reports Server (NTRS)

    Partz, Earl

    1998-01-01

    Alkaline cleaners used to process aluminum substrates have contained chromium as the corrosion inhibitor. Chromium is a hazardous substance whose use and control are described by environmental laws. Replacement materials that have the characteristics of chromated alkaline cleaners need to be found that address both the cleaning requirements and environmental impacts. This report will review environmentally friendly candidates evaluated as non-chromium alkaline cleaner replacements and methods used to compare those candidates one versus another. The report will also list characteristics used to select candidates based on their declared contents. It will also describe and evaluate methods used to discriminate among the large number of prospective candidates.

  18. 40 CFR 721.3486 - Polyglycerin mono(4-nonylphenyl) ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polyglycerin mono(4-nonylphenyl) ether... Substances § 721.3486 Polyglycerin mono(4-nonylphenyl) ether. (a) Chemical substance and significant new uses...-nonylphenyl) ether (PMN P-94-2230) is subject to reporting under this section for the significant new...

  19. 40 CFR 721.3486 - Polyglycerin mono(4-nonylphenyl) ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Polyglycerin mono(4-nonylphenyl) ether... Substances § 721.3486 Polyglycerin mono(4-nonylphenyl) ether. (a) Chemical substance and significant new uses...-nonylphenyl) ether (PMN P-94-2230) is subject to reporting under this section for the significant new...

  20. 40 CFR 721.10505 - Phosphoric acid, mixed mono- and diesters with 2-ethyl-1-hexanol and polyethylene glycol mono-C12...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phosphoric acid, mixed mono- and... Phosphoric acid, mixed mono- and diesters with 2-ethyl-1-hexanol and polyethylene glycol mono-C12-16-alkyl... identified as phosphoric acid, mixed mono- and diesters with 2-ethyl-1-hexanol and polyethylene glycol...

  1. 40 CFR 721.10505 - Phosphoric acid, mixed mono- and diesters with 2-ethyl-1-hexanol and polyethylene glycol mono-C12...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phosphoric acid, mixed mono- and... Phosphoric acid, mixed mono- and diesters with 2-ethyl-1-hexanol and polyethylene glycol mono-C12-16-alkyl... identified as phosphoric acid, mixed mono- and diesters with 2-ethyl-1-hexanol and polyethylene glycol...

  2. Viscoelasticity of mono- and polydisperse inverse ferrofluids.

    PubMed

    Saldivar-Guerrero, Ruben; Richter, Reinhard; Rehberg, Ingo; Aksel, Nuri; Heymann, Lutz; Rodriguez-Fernández, Oliverio S

    2006-08-28

    We report on measurements of a magnetorheological model fluid created by dispersing nonmagnetic microparticles of polystyrene in a commercial ferrofluid. The linear viscoelastic properties as a function of magnetic field strength, particle size, and particle size distribution are studied by oscillatory measurements. We compare the results with a magnetostatic theory proposed by De Gans et al. [Phys. Rev. E 60, 4518 (1999)] for the case of gap spanning chains of particles. We observe these chain structures via a long distance microscope. For monodisperse particles we find good agreement of the measured storage modulus with theory, even for an extended range, where the linear magnetization law is no longer strictly valid. Moreover we compare for the first time results for mono- and polydisperse particles. For the latter, we observe an enhanced storage modulus in the linear regime of the magnetization. PMID:16965057

  3. Mono Lake's Radiocarbon Budget: An unsolved enigma

    NASA Astrophysics Data System (ADS)

    Broecker, Wallace; Stine, Scott

    Mono Lake occupies a semiarid basin just east of the central Sierra Nevada in California. During the past 4 decades, diversion of the lake's tributary streams by the Los Angeles Department of Water and Power (LADWP) has caused the lake to shrink dramatically. This shrinkage has concentrated the salts that occur naturally in the lake, forcing the salinity to rise toward levels that will cause the extinction of the resident brine shrimp and brine flies that provide food for many hundreds of thousands of migratory waterfowl. The lake is now the focus of a pitched battle between conservationists who want to curtail diversions before serious ecological consequences occur and the LADWP, whose responsibility is to supply the city with water.

  4. Gaylussite formation at mono lake, california

    USGS Publications Warehouse

    Bischoff, J.L.; Herbst, D.B.; Rosenbauer, R.J.

    1991-01-01

    The salinity of Mono Lake has steadily increased since 1941 from 50%. to about 90%. due to diversion of tributary streams. This increase has resulted in the newly discovered precipitation of gaylussite (Na2Ca(CO3)2 ?? 5H2O). Chemical modeling of the lake water using Pitzer equations suggests that gaylussite has been forming year round since about 1970 when the salinity first exceeded 80%., and that it was earlier forming intermittently at lower salinities in the winter shortly after diversion began, breaking down incongruently to aragonite during summers. Lake water appears to remain at a constant 9-fold supersaturation with aragonite at all salinities, perhaps buffered by monohydrocalcite which appears to be just at saturation for all salinities. Other saline lakes also appear to be buffered by monohydrocalcite. ?? 1991.

  5. Mechanisms of Selenomethionine Developmental Toxicity and the Impacts of Combined Hypersaline Conditions on Japanese Medaka (Oryzias latipes)

    PubMed Central

    2015-01-01

    Selenium (Se) is an essential micronutrient that can cause embryotoxicty at levels 7–30 times above essential concentrations. Exposure to hypersaline conditions and 50 μM selenomethionine (SeMet) decreased embryo hatch and depleted glutathione in Japanese medaka embryos without affecting Se accumulation. To better understand the impacts of nonchemical stressors on developmental toxicity of Se in fish, several adverse outcome pathways were evaluated in the Japanese medaka (Oryzias latipes). We treated medaka embryos at 12 h post fertilization with 50 μM SeMet for 12 hours in freshwater or in 13 ppth hypersalinity and evaluated the contributions of oxidative stress, the unfolded protein response and apoptosis to reduced hatch. Exposure to SeMet and hypersalinity decreased embryo hatch to 3.7% ± 1.95, and induced teratogenesis in 100% ± 0 of hatched embryos. In contrast, treatments of freshwater, saltwater, and SeMet in freshwater resulted in 89.8% ± 3.91–86.7% ± 3.87 hatch, and no significant increase in deformities. We found no significant differences in lipid peroxidation, indicating that oxidative stress may not be responsible for the observed toxicity in embryos at this time point (24 h). Although significant changes in apoptosis were not observed, we witnessed up to 100 fold increases in transcripts of the endoplasmic reticulum (ER) chaperone, immunoglobulin binding protein (BiP) and trends toward increasing downstream signals, activating transcription factor 4 (ATF4) and ATF6 indicating potential contributions of the unfolded protein response to the effects of SeMet and hypersaline conditions. These data indicate that multiple adverse outcome pathways may be responsible for the developmental toxicity of Se and salinity, and these pathways may be time dependent. PMID:24856650

  6. The modulation of leaf metabolism plays a role in salt tolerance of Cymodocea nodosa exposed to hypersaline stress in mesocosms

    PubMed Central

    Piro, Amalia; Marín-Guirao, Lázaro; Serra, Ilia A.; Spadafora, Antonia; Sandoval-Gil, José M.; Bernardeau-Esteller, Jaime; Fernandez, Juan M. R.; Mazzuca, Silvia

    2015-01-01

    Applying proteomics, we tested the physiological responses of the euryhaline seagrass Cymodocea nodosa to deliberate manipulation of salinity in a mesocosm system. Plants were subjected to a chronic hypersaline condition (43 psu) to compare protein expression and plant photochemistry responses after 15 and 30 days of exposure with those of plants cultured under normal/ambient saline conditions (37 psu). Results showed a general decline in the expression level of leaf proteins in hypersaline stressed plants, with more intense reductions after long-lasting exposure. Specifically, the carbon-fixing enzyme RuBisCo displayed a lower accumulation level in stressed plants relative to controls. In contrast, the key enzymes involved in the regulation of glycolysis, cytosolic glyceraldehyde-3-phosphate dehydrogenase, enolase 2 and triose-phosphate isomerase, showed significantly higher accumulation levels. These responses suggested a shift in carbon metabolism in stressed plants. Hypersaline stress also induced a significant alteration of the photosynthetic physiology of C. nodosa by means of a down-regulation in structural proteins and enzymes of both PSII and PSI. However we found an over-expression of the cytochrome b559 alpha subunit of the PSII initial complex, which is a receptor for the PSII core proteins involved in biogenesis or repair processes and therefore potentially involved in the absence of effects at the photochemical level of stressed plants. As expected hypersalinity also affects vacuolar metabolism by increasing the leaf cell turgor pressure and enhancing the up-take of Na+ by over-accumulating the tonoplast specific intrinsic protein pyrophosphate-energized inorganic pyrophosphatase (H(+)-PPase) coupled to the Na+/H+-antiporter. The modulation of carbon metabolism and the enhancement of vacuole capacity in Na+ sequestration and osmolarity changes are discussed in relation to salt tolerance of C. nodosa. PMID:26167167

  7. Mono-cadmium vs Mono-mercury Doping of Au25 Nanoclusters.

    PubMed

    Yao, Chuanhao; Lin, Yue-jian; Yuan, Jinyun; Liao, Lingwen; Zhu, Min; Weng, Lin-hong; Yang, Jinlong; Wu, Zhikun

    2015-12-16

    Controlling the dopant type, number, and position in doped metal nanoclusters (nanoparticles) is crucial but challenging. In the work described herein, we successfully achieved the mono-cadmium doping of Au25 nanoclusters, and revealed using X-ray crystallography in combination with theoretical calculations that one of the inner-shell gold atoms of Au25 was replaced by a Cd atom. The doping mode is distinctly different from that of mono-mercury doping, where one of the outer-shell Au atoms was replaced by a Hg atom. Au24Cd is readily transformed to Au24Hg, while the reverse (transformation from Au24Hg to Au24Cd) is forbidden under the investigated conditions. PMID:26595532

  8. The alkaline and alkaline-carbonatite magmatism from Southern Brazil

    NASA Astrophysics Data System (ADS)

    Ruberti, E.; Gomes, C. D. B.; Comin-Chiaramonti, P.

    2015-12-01

    Early to Late Cretaceous lasting to Paleocene alkaline magmatism from southern Brazil is found associated with major extensional structural features in and around the Paraná Basin and grouped into various provinces on the basis of several data. Magmatism is variable in size, mode of occurrence and composition. The alkaline rocks are dominantly potassic, a few occurrences showing sodic affinity. The more abundant silicate rocks are evolved undersaturated to saturated in silica syenites, displaying large variation in igneous forms. Less evolved types are restricted to subvolcanic environments and outcrops of effusive suites occur rarely. Cumulatic mafic and ultramafic rock types are very common, particularly in the alkali-carbonatitic complexes. Carbonatite bodies are represented by Ca-carbonatites and Mg-carbonatites and more scarcely by Fe-carbonatites. Available radiometric ages for the alkaline rocks fit on three main chronological groups: around 130 Ma, subcoveal with the Early Cretaceous flood tholeiites of the Paraná Basin, 100-110 Ma and 80-90 Ma (Late Cretaceous). The alkaline magmatism also extends into Paleocene times, as indicated by ages from some volcanic lavas. Geochemically, alkaline potassic and sodic rock types are distinguished by their negative and positive Nb-Ta anomalies, respectively. Negative spikes in Nb-Ta are also a feature common to the associated tholeiitic rocks. Sr-Nd-Pb systematics confirm the contribution of both HIMU and EMI mantle components in the formation of the alkaline rocks. Notably, Early and Late Cretaceous carbonatites have the same isotopic Sr-Nd initial ratios of the associated alkaline rocks. C-O isotopic Sr-Nd isotopic ratios indicate typical mantle signature for some carbonatites and the influence of post-magmatic processes in others. Immiscibility of liquids of phonolitic composition, derived from mafic alkaline parental magmas, has been responsible for the origin of the carbonatites. Close association of alkaline

  9. Hypersaline groundwater genesis assessment through a multidisciplinary approach: the case of Pozzo del Sale Spring (southern Italy)

    NASA Astrophysics Data System (ADS)

    Celico, Fulvio; Capuano, Paolo; de Felice, Vincenzo; Naclerio, Gino

    2008-11-01

    A tool, based on a multidisciplinary field investigation approach for studying the characteristics of a hypersaline spring, was developed and its effectiveness tested on a spring in southern Italy; a preliminary model of the aquifer system at medium and local scale was derived. Hydrologic measurements, vertical electric soundings, and chemical and isotopic (δ18O, δ2H, 3H) analyses were undertaken, along with microbiological analyses and species identification. These demonstrate the coexistence of hypersaline and fresh water, generating a significant diversification of the groundwater hydrochemical signature. The isotopic signature shows that both types of water have a meteoric origin. Microbial contamination of fecal origin indicates the mixing of hyper- and low- saline water related to local infiltration. The hypersaline groundwater flows in confined horizons within a sequence that is mainly of fractured clays. These horizons are probably concentrated where well-developed fracture network and dissolution openings within evaporitic rocks enhance fluid flow. In a wider context, this study determines that microbiological pollution of saline groundwater may not be detected if using nonhalophilic bacterial indicators such as fecal coliforms. Fecal enterococci are better indicators, due to their higher halotolerance.

  10. Methanogenic diversity and activity in hypersaline sediments of the centre of the Napoli mud volcano, Eastern Mediterranean Sea.

    PubMed

    Lazar, Cassandre Sara; Parkes, R John; Cragg, Barry A; L'Haridon, Stéphane; Toffin, Laurent

    2011-08-01

    Submarine mud volcanoes are a significant source of methane to the atmosphere. The Napoli mud volcano, situated in the brine-impacted Olimpi Area of the Eastern Mediterranean Sea, emits mainly biogenic methane particularly at the centre of the mud volcano. Temperature gradients support the suggestion that Napoli is a cold mud volcano with moderate fluid flow rates. Biogeochemical and molecular genetic analyses were carried out to assess the methanogenic activity rates, pathways and diversity in the hypersaline sediments of the centre of the Napoli mud volcano. Methylotrophic methanogenesis was the only significant methanogenic pathway in the shallow sediments (0-40 cm) but was also measured throughout the sediment core, confirming that methylotrophic methanogens could be well adapted to hypersaline environments. Hydrogenotrophic methanogenesis was the dominant pathway below 50 cm; however, low rates of acetoclastic methanogenesis were also present, even in sediment layers with the highest salinity, showing that these methanogens can thrive in this extreme environment. PCR-DGGE and methyl coenzyme M reductase gene libraries detected sequences affiliated with anaerobic methanotrophs (mainly ANME-1) as well as Methanococcoides methanogens. Results show that the hypersaline conditions in the centre of the Napoli mud volcano influence active biogenic methane fluxes and methanogenic/methylotrophic diversity. PMID:21382146

  11. Intercultural Interactions of Mono-Cultural, Mono-Lingual Local Students in Small Group Learning Activities: A Bourdieusian Analysis

    ERIC Educational Resources Information Center

    Colvin, Cassandra; Fozdar, Farida; Volet, Simone

    2015-01-01

    This research examines the understandings and experiences of mono-cultural, mono-lingual local students in relation to intercultural interactions within small group learning activities at university. Bourdieu's concepts of field, habitus and capital are employed to illuminate a number of barriers to intercultural interaction. Using qualitative…

  12. The geomorphology of two hyper-saline springs in the Canadian High Arctic

    NASA Astrophysics Data System (ADS)

    Ward, Melissa; Pollard, Wayne

    2015-04-01

    On Axel Heiberg Island in the Canadian High Arctic, many low temperature perennial saline springs occur despite cold polar desert climate conditions marked by a mean annual air temperature of -18°C. Associated with 2 groups of hyper-saline springs are distinctive landforms resulting from winter deposition of salt minerals. These deposits resemble tufas structurally, but unlike true tufas which are composed of carbonate minerals, these landforms are formed mainly of salt. This study hypothesizes that the extreme cold winter air temperatures cool water temperatures triggering rapid precipitation of various salt minerals [mainly hydrohalite (NaCl*2H2O)]. These newly formed salt minerals subsequently alter the flow hydrology by obstructing summer flow paths. The tufa-like appearance of these salt deposits reflects the interaction between changing water temperature, chemistry and flow.This research characterises the geomorphology and geochemistry of two hyper-saline springs on Axel Heiberg Island: the first is located at Wolf Diapir (79°07'23"N; 90°14'39"W), the deposit at this site resembles a large conical mound (2.5m tall x 3m diameter). The second is located at Stolz Diapir (79°04'30"N; 87°04'30"W). In this case a series of pool and barrage structures staircase down a narrow valley for approximately 300m (several pools are up to 10 m wide x 3 m deep). The springs have very different seasonal surface hydrologic regimes and topographic settings which influence the pattern of mineral precipitates. The accumulation of precipitates occurs during the winter and is dominated by the formation of hydrohalite. In the summer, the accumulated hydrohalite melts incongruently to form halite. In addition, spring water and snowmelt dissolve various parts of the accumulations, changing the morphology of the deposits. This presentation will focus on results from four periods of fieldwork (two in spring for winter conditions and two in summer) including results from time

  13. Cross-hole ERT monitoring of freshwater injection in a hyper-saline aquifer

    NASA Astrophysics Data System (ADS)

    Haaken, K.; Deidda, G. P.; Cassiani, G.; Kemna, A.; Deiana, R.; Putti, M.; Paniconi, C.; Schirru, F.; Mura, M.

    2012-04-01

    In November 2011 we performed a freshwater injection experiment in the hyper-saline aquifer underlying the Molentargius-Saline Regional Park located near Cagliari in southern Sardinia, very close to the coastline. The subsurface water reaches salinity levels as high as three times the NaCl content of seawater, most likely as a consequence of salt release from the nearby salt works, active from Roman times to the mid-twentieth century. Five ERT boreholes were drilled with 4 inches inner diameter to a depth of 20 m and positioned in the shape of a square with an 8-m long side, with one borehole at the centre. All boreholes are equipped with a fully screened PVC pipe bearing externally twenty-four stainless steel cylindrical electrodes from 0.6 m to 19 m depth with 0.8 m separation. The water table is stable around -5.2 m from the ground surface. The sediments are mostly composed of sands with thin layers of silty sand, clayey sand and silty clay. Electric fluid logs recorded in the boreholes allowed to discriminate two zones, with a transitional layer in between: (a) from the water table to 7.5 m the water electrical conductivity is about 2 S/m; (b) below 12 m depth the water electrical conductivity reaches 18.5 S/m. In November 2011 we injected 19.4 m3 of freshwater in about 4 hours using a double packer system positioned in the central borehole, with an injection chamber located between 13.5 and 14.5 m below ground surface. Time-lapse ERT monitoring was achieved by measuring along two 2D ERT planes corresponding to the two square diagonals, thus involving three boreholes at a time for a total of 72 electrodes. A mixture of skip 0 dipole-dipole and bipole-bipole configurations was used in each acquisition, that required about 1 hour using an IRIS Syscal Pro resistivity meter. The resulting ERT time-lapse images show clearly the development and motion of the injected freshwater bulb, that undergoes a fast vertical migration and a quick disappearance probably caused

  14. Monitoring The Dynamics Of Hyper-Saline Environments With Polarimetric SAR: Death Valley, California Example

    NASA Astrophysics Data System (ADS)

    Lasne, Y.; McDonald, K.; Paillou, P.; Freeman, A.; Chapman, B.; Farr, T.; Ruffié, G.; Malézieux, J.

    2008-12-01

    Soil salinization in arid and semi-arid regions still remains one of the most important threats not only for socio-economical issues when dealing with water ressources management, but also for ecological matters such as: desertification, climate changes, and biomass reduction. Then, monitoring and mapping of soil salinity distribution represent today a key challenge in our understanding of such environmental processes. Being highly dependent on the dielectric properties of soils, synthetic aperture radar (SAR) appears to be an efficient tool for the remote sensing of hyper-saline environments. More precisely, the influence of saline deposits on SAR imagery lies in the solubility and ionic properties of the minerals which strongly influence both real and imaginary parts of the complex permittivity of such deposits, and thus the radar backscattering coefficient. Based on temporal series acquired with spaceborne SAR systems (ALOS/PALSAR, SIR-C) over the Death Valley (CA), we show that the copolarized backscattering ratio and phase difference derived from SAR data can be used as suitable indicators to monitor the dynamics of hyper-saline deposits. In particular, we propose these copolar parameters to follow the variations in the dielectric properties of moistened and salt-affected soils on a seasonal time scale because of the close relationship between the salinity (governed by the soil moisture content) and the complex permittivity of the soils. We also highlight a strong temporal correlation between the copolar parameters and weather data since precipitation events control the soil moisture and salinity. In order to allow for a better interpretation of the saline deposits signatures observed on SAR data, we also perform analytical simulations of the radar backscattering associated with saline deposits by means of the IEM scattering model. Using laboratory and in~ situ dielectric measurements as input parameters, we simulate the copolar ratio and phase difference as

  15. Microbial Fe cycling and mineralization in sediments of an acidic, hypersaline lake (Lake Tyrell, Victoria, Australia)

    NASA Astrophysics Data System (ADS)

    Roden, E. E.; Blöthe, M.; Shelobolina, E.

    2009-12-01

    Lake Tyrrell is a variably acidic, hypersaline, Fe-rich lake located in Victoria, Australia. Terrestrial acid saline lakes like Lake Tyrrell may be analogs for ancient Martian surface environments, as well as possible extant subsurface environments. To investigate the potential for microbial Fe cycling under acidic conditions and high salt concentration, we collected sediment core samples during three field trips between 2006 and 2008 from the southern, acidic edge of the lake. Materials from the cores were used for chemical and mineralogical analyses, as well as for molecular (16S rRNA genes) and culture-based microbiological studies. Near-surface (< 1 m depth) pore fluids contained low but detectable dissolved oxygen (ca. 50 uM), significant dissolved Fe(II) (ca. 500 uM), and nearly constant pH of around 4 - conditions conducive to enzymatic Fe(II) oxidation. High concentrations of Fe(III) oxides begin accumulate at a depth of ca. 10 cm, and may reflect the starting point for formation of massive iron concretions that are evident at and beneath the sediment surface. MPN analyses revealed low (10-100 cells/mL) but detectable populations of aerobic, halophilic Fe(II)-oxidizing organisms on the sediment surface and in the near-surface ground water. With culture-dependent methods at least three different halotolerant lithoautotrophic cultures growing on Fe(II), thiosulfate, or tetrathionate from different acidic sites were obtained. Analysis of 16S rRNA gene sequences revealed that these organisms are similar to previous described gamma proteobacteria Thiobacillus prosperus (95%), Halothiobacillus kellyi (99%), Salinisphaera shabanense (95%) and a Marinobacter species. (98%). 16S rRNA gene pyrosequencing data from two different sites with a pH range between 3 and 4.5 revealed a dominance of gamma proteobacteria. 16S rRNA gene pyrosequencing libraries from both cores were dominated by sequences related to the Ectothiorhodospiraceae family, which includes the taxa

  16. Microbial Diversity in Maras Salterns, a Hypersaline Environment in the Peruvian Andes

    PubMed Central

    Maturrano, Lenin; Santos, Fernando; Rosselló-Mora, Ramon; Antón, Josefa

    2006-01-01

    Maras salterns are located 3,380 m above sea level in the Peruvian Andes. These salterns consist of more than 3,000 little ponds which are not interconnected and act as crystallizers where salt precipitates. These ponds are fed by hypersaline spring water rich in sodium and chloride. The microbiota inhabiting these salterns was examined by fluorescence in situ hybridization (FISH), 16S rRNA gene clone library analysis, and cultivation techniques. The total counts per milliliter in the ponds were around 2 × 106 to 3 × 106 cells/ml, while the spring water contained less than 100 cells/ml and did not yield any detectable FISH signal. The microbiota inhabiting the ponds was dominated (80 to 86% of the total counts) by Archaea, while Bacteria accounted for 10 to 13% of the 4′,6′-diamidino-2-phenylindole (DAPI) counts. A total of 239 16S rRNA gene clones were analyzed (132 Archaea clones and 107 Bacteria clones). According to the clone libraries, the archaeal assemblage was dominated by microorganisms related to the cosmopolitan square archaeon “Haloquadra walsbyi,” although a substantial number of the sequences in the libraries (31% of the 16S rRNA gene archaeal clones) were related to Halobacterium sp., which is not normally found in clone libraries from solar salterns. All the bacterial clones were closely related to each other and to the γ-proteobacterium “Pseudomonas halophila” DSM 3050. FISH analysis with a probe specific for this bacterial assemblage revealed that it accounted for 69 to 76% of the total bacterial counts detected with a Bacteria-specific probe. When pond water was used to inoculate solid media containing 25% total salts, both extremely halophilic Archaea and Bacteria were isolated. Archaeal isolates were not related to the isolates in clone libraries, although several bacterial isolates were very closely related to the “P. halophila” cluster found in the libraries. As observed for other hypersaline environments, extremely

  17. Calcium Biomineralization in Sediment of Lake Acigol, an Hypersaline Lake in SW Turkey

    NASA Astrophysics Data System (ADS)

    Celik Balci, Nurgul; Menekse, Meryem; Sonmez, Seref; Gul Karaguler, Nevin

    2010-05-01

    The study of biomineralization in (hyper) saline environments is important for two reasons, 1-it can extend our knowledge about the earliest microbial life on Earth which may have been halophilic 2-because of the presence of hypersaline conditions on Mars, the analog environments in Earth may have implications for the possibility of life on Mars. We examine calcium biomineralization in Lake Acigol, a unique hypersaline lake in southwest Turkey by integrating geochemical and microbiological approaches. Lake Acigol is a perennial lake with a maximum salinity of about 200 g/L and covers an area of 55-60 km2and is one of the main salt reservoirs of Turkey. Water, sediment and core samples were taken from the lake and salty ponds around the lake during the field excursion. The water chemistry revealed relatively high Na and SO4 concentrations both in the lake (30 gr/L, 33.36 gr/L), and the ponds (100 mg/L, 123 mg/L). The mineralogical analyses of sediments showed gypsum, halite, carbonate (aragonite, huntite) precipitation in the lake and ponds. We employed culture-dependent (16s rRNA cloning method, enrichment culture), and -independent techniques to study microbial diversity in Lake Aci gol. Sediment samples were used to isolate Halophilic sp. (e.g. salinicoccus roseus , Dunella sp.) under salinities that were similar to those measured in the lake water to further use in the laboratory Ca-precipitation experiments. For the precipitation experiments, liquid and solid culture media with various salinities ( 6-25 %) in addition to one similar to the lake water were prepared. In order to determine effect of Mg2+-Ca2+ molar ratio on mineralogy and the rate of precipitation, media with different Ca2+and Mg2+ concentrations were also prepared. Our preliminary results indicate that the halophilic bacteria play active role in the precipitation of Ca-minerals but the geochemical conditions are clearly influential. The results also point out that in the Lake Aci gol C, N, P, Ca

  18. Three Dimensional Visualization of Mono Basin, California from Geophysical Studies

    NASA Astrophysics Data System (ADS)

    Peacock, J.; McPhee, D.; Ponce, D. A.; Mangan, M.; MacPherson-Krutsky, C. C.; Matson, G.

    2013-12-01

    Mono Basin, east of the Sierra Nevada Mountains, is an area of great interest not only because of recent volcanic activity, but also as a region of geothermal potential. Not surprisingly, most of the geophysical data collected in the region has been focused on Long Valley Caldera and Mammoth Mountain due to recent seismic activity in the south moat, uplift of a central resurgent dome in the Caldera, and enhanced CO2 emissions near Mammoth Mountain. Consequently, there is a void of geophysical information on the Mono-Inyo Craters, a chemically distinct volcanic chain north of Long Valley. The Mono-Inyo chain is nominally two parts but volcanically similar; the Inyo Craters form a north trending linear chain and the Mono craters form an arcuate chain concave towards the west, bounding the east side of Mono Basin. In the last two years, gravity, high-resolution aeromagnetic, audio-magnetotelluric (AMT) and magnetotelluric (MT) data have been collected around Mono Craters. The focus of this study is the Mono Basin, where interesting features have been found from 3D visualization of these geophysical data. One prominent feature is a large circular magnetic anomaly with a diameter of 10~km stretching from Mono Craters to the base of the Sierra Nevada, where the geometry of Mono Craters follow the eastern part of this anomaly. This circular anomaly has been suggested to be a ring fracture, but sparse surface data leaves this theory unconstrained. Another feature is an interpreted deep (~ 600 m) fault (previously unmapped) just west of Mono Craters inside the circular magnetic anomaly. This structure correlates with a conductive high in the 3D resistivity model found from the AMT data and 2D resistivity model from newly collected MT data, a gravity gradient, and a positive magnetic anomaly in the aeromagnetic data. Moreover, this fault may be an important structural constraint on the formation of Mono Craters, because it may explain why the Mono Craters form an arcuate

  19. Metagenomic insights into strategies of carbon conservation and unusual sulfur biogeochemistry in a hypersaline Antarctic lake

    PubMed Central

    Yau, Sheree; Lauro, Federico M; Williams, Timothy J; DeMaere, Matthew Z; Brown, Mark V; Rich, John; Gibson, John AE; Cavicchioli, Ricardo

    2013-01-01

    Organic Lake is a shallow, marine-derived hypersaline lake in the Vestfold Hills, Antarctica that has the highest reported concentration of dimethylsulfide (DMS) in a natural body of water. To determine the composition and functional potential of the microbial community and learn about the unusual sulfur chemistry in Organic Lake, shotgun metagenomics was performed on size-fractionated samples collected along a depth profile. Eucaryal phytoflagellates were the main photosynthetic organisms. Bacteria were dominated by the globally distributed heterotrophic taxa Marinobacter, Roseovarius and Psychroflexus. The dominance of heterotrophic degradation, coupled with low fixation potential, indicates possible net carbon loss. However, abundant marker genes for aerobic anoxygenic phototrophy, sulfur oxidation, rhodopsins and CO oxidation were also linked to the dominant heterotrophic bacteria, and indicate the use of photo- and lithoheterotrophy as mechanisms for conserving organic carbon. Similarly, a high genetic potential for the recycling of nitrogen compounds likely functions to retain fixed nitrogen in the lake. Dimethylsulfoniopropionate (DMSP) lyase genes were abundant, indicating that DMSP is a significant carbon and energy source. Unlike marine environments, DMSP demethylases were less abundant, indicating that DMSP cleavage is the likely source of high DMS concentration. DMSP cleavage, carbon mixotrophy (photoheterotrophy and lithoheterotrophy) and nitrogen remineralization by dominant Organic Lake bacteria are potentially important adaptations to nutrient constraints. In particular, carbon mixotrophy relieves the extent of carbon oxidation for energy production, allowing more carbon to be used for biosynthetic processes. The study sheds light on how the microbial community has adapted to this unique Antarctic lake environment. PMID:23619305

  20. Biogeochemistry of Hypersaline Springs Supporting a Mid-Continent Marine Ecosystem: An Analogue for Martian Springs?

    NASA Astrophysics Data System (ADS)

    Grasby, Stephen E.; Londry, Kathleen L.

    2007-08-01

    Hypersaline springs that host unique mid-continent marine ecosystems were examined in central Manitoba, Canada. The springs originate from a reflux of glacial meltwater that intrudes into underlying bedrock and dissolved buried salt beds. Two spring types were distinguished based both on flow rate and geochemistry. High flow springs (greater than 10 L/s) hosted extensive marine microbial mats, which were dominated by algae but also included diverse microbes. These varied somewhat between springs as indicated by changes in profiles of fatty acid methyl esters. Culture studies confirmed the presence of sulfate-reducing bacteria in sediments at the high flow sites. In contrast, low flow springs were affected by solar evaporation, increasing salinity, and temperature. These low flow springs behaved more like closed nutrient-limited systems and did not support microbial mats. Direct comparison of the high and low flow springs revealed interesting implications for the potential to record biosignatures in the rock record. High flow springs have abundant, well-developed microbial mats, which desiccate and are cemented along the edges of the spring pools; however, the high mass flux overwhelms any geochemical signature of microbial activity. In contrast, the nutrient-limited low flow sites develop strong geochemical signatures of sulfate reduction, even in the absence of microbial mats, due to less dilution with the lower flows. Geochemical and physical evidence for life did not correlate with the abundance of microbial life but, rather, with the extent to which the biological system formed a closed ecosystem.

  1. Environmental selection of protistan plankton communities in hypersaline anoxic deep-sea basins, Eastern Mediterranean Sea

    PubMed Central

    Filker, Sabine; Stock, Alexandra; Breiner, Hans-Werner; Edgcomb, Virginia; Orsi, William; Yakimov, Michail M; Stoeck, Thorsten

    2013-01-01

    High salt concentrations, absence of light, anoxia, and high hydrostatic pressure make deep hypersaline anoxic basins (DHABs) in the Eastern Mediterranean Sea one of the most polyextreme habitats on Earth. Taking advantage of the unique chemical characteristics of these basins, we tested the effect of environmental selection and geographic distance on the structure of protistan communities. Terminal restriction fragment length polymorphism (T-RFLP) analyses were performed on water samples from the brines and seawater/brine interfaces of five basins: Discovery, Urania, Thetis, Tyro, and Medee. Using statistical analyses, we calculated the partitioning of diversity among the ten individual terminal restriction fragment (T-RF) profiles, based on peak abundance and peak incidence. While a significant distance effect on spatial protistan patterns was not detected, hydrochemical gradients emerged as strong dispersal barriers that likely lead to environmental selection in the DHAB protistan plankton communities. We identified sodium, magnesium, sulfate, and oxygen playing in concerto as dominant environmental drivers for the structuring of protistan plankton communities in the Eastern Mediterranean DHABs. PMID:23239531

  2. Quantitative Proteomics Reveals Membrane Protein-Mediated Hypersaline Sensitivity and Adaptation in Halophilic Nocardiopsis xinjiangensis.

    PubMed

    Zhang, Yao; Li, Yanchang; Zhang, Yongguang; Wang, Zhiqiang; Zhao, Mingzhi; Su, Na; Zhang, Tao; Chen, Lingsheng; Wei, Wei; Luo, Jing; Zhou, Yanxia; Xu, Yongru; Xu, Ping; Li, Wenjun; Tao, Yong

    2016-01-01

    The genus Nocardiopsis is one of the most dominant Actinobacteria that survives in hypersaline environments. However, the adaptation mechanisms for halophilism are still unclear. Here, we performed isobaric tags for relative and absolute quantification based quantitative proteomics to investigate the functions of the membrane proteome after salt stress. A total of 683 membrane proteins were identified and quantified, of which 126 membrane proteins displayed salt-induced changes in abundance. Intriguingly, bioinformatics analyses indicated that these differential proteins showed two expression patterns, which were further validated by phenotypic changes and functional differences. The majority of ABC transporters, secondary active transporters, cell motility proteins, and signal transduction kinases were up-regulated with increasing salt concentration, whereas cell differentiation, small molecular transporter (ions and amino acids), and secondary metabolism proteins were significantly up-regulated at optimum salinity, but down-regulated or unchanged at higher salinity. The small molecule transporters and cell differentiation-related proteins acted as sensing proteins that played a more important biological role at optimum salinity. However, the ABC transporters for compatible solutes, Na(+)-dependent transporters, and cell motility proteins acted as adaptive proteins that actively counteracted higher salinity stress. Overall, regulation of membrane proteins may provide a major protection strategy against hyperosmotic stress. PMID:26549328

  3. Predominance of biotic over abiotic formation of halogenated hydrocarbons in hypersaline sediments in Western Australia.

    PubMed

    Ruecker, A; Weigold, P; Behrens, S; Jochmann, M; Laaks, J; Kappler, A

    2014-08-19

    Volatile halogenated organic compounds (VOX) contribute to ozone depletion and global warming. There is evidence of natural VOX formation in many environments ranging from forest soils to salt lakes. Laboratory studies have suggested that VOX formation can be chemically stimulated by reactive Fe species while field studies have provided evidence for direct biological (enzymatic) VOX formation. However, the relative contribution of abiotic and biotic processes to global VOX budgets is still unclear. The goals of this study were to quantify VOX release from sediments from a hypersaline lake in Western Australia (Lake Strawbridge) and to distinguish between the relative contributions of biotic and abiotic VOX formation in microbially active and sterilized microcosms. Our experiments demonstrated that the release of organochlorines from Lake Strawbridge sediments was mainly biotic. Among the organochlorines detected were monochlorinated, e.g., chloromethane (CH3Cl), and higher chlorinated VOX compounds such as trichloromethane (CHCl3). Amendment of sediments with either Fe(III) oxyhydroxide (ferrihydrite) or a mixture of lactate/acetate or both ferrihydrite and lactate/acetate did not stimulate VOX formation. This suggests that although microbial Fe(III) reduction took place, there was no stimulation of VOX formation via Fe redox transformations or the formation of reactive Fe species under our experimental conditions. PMID:25073729

  4. Potential for Plant Growth Promotion of Rhizobacteria Associated with Salicornia Growing in Tunisian Hypersaline Soils

    PubMed Central

    Mapelli, Francesca; Marasco, Ramona; Rolli, Eleonora; Barbato, Marta; Cherif, Hanene; Guesmi, Amel; Ouzari, Imen; Daffonchio, Daniele; Borin, Sara

    2013-01-01

    Soil salinity and drought are among the environmental stresses that most severely affect plant growth and production around the world. In this study the rhizospheres of Salicornia plants and bulk soils were collected from Sebkhet and Chott hypersaline ecosystems in Tunisia. Depiction of bacterial microbiome composition by Denaturing Gradient Gel Electrophoresis unveiled the occurrence of a high bacterial diversity associated with Salicornia root system. A large collection of 475 halophilic and halotolerant bacteria was established from Salicornia rhizosphere and the surrounding bulk soil, and the bacteria were characterized for the resistance to temperature, osmotic and saline stresses, and plant growth promotion (PGP) features. Twenty Halomonas strains showed resistance to a wide set of abiotic stresses and were able to perform different PGP activities in vitro at 5% NaCl, including ammonia and indole-3-acetic acid production, phosphate solubilisation, and potential nitrogen fixation. By using a gfp-labelled strain it was possible to demonstrate that Halomonas is capable of successfully colonising Salicornia roots in the laboratory conditions. Our results indicated that the culturable halophilic/halotolerant bacteria inhabiting salty and arid ecosystems have a potential to contribute to promoting plant growth under the harsh salinity and drought conditions. These halophilic/halotolerant strains could be exploited in biofertilizer formulates to sustain crop production in degraded and arid lands. PMID:23781499

  5. Microbial ecology of an Antarctic hypersaline lake: genomic assessment of ecophysiology among dominant haloarchaea

    PubMed Central

    Williams, Timothy J; Allen, Michelle A; DeMaere, Matthew Z; Kyrpides, Nikos C; Tringe, Susannah G; Woyke, Tanja; Cavicchioli, Ricardo

    2014-01-01

    Deep Lake in Antarctica is a cold, hypersaline system where four types of haloarchaea representing distinct genera comprise >70% of the lake community: strain tADL ∼44%, strain DL31 ∼18%, Halorubrum lacusprofundi ∼10% and strain DL1 ∼0.3%. By performing comparative genomics, growth substrate assays, and analyses of distribution by lake depth, size partitioning and lake nutrient composition, we were able to infer important metabolic traits and ecophysiological characteristics of the four Antarctic haloarchaea that contribute to their hierarchical persistence and coexistence in Deep Lake. tADL is characterized by a capacity for motility via flagella (archaella) and gas vesicles, a highly saccharolytic metabolism, a preference for glycerol, and photoheterotrophic growth. In contrast, DL31 has a metabolism specialized in processing proteins and peptides, and appears to prefer an association with particulate organic matter, while lacking the genomic potential for motility. H. lacusprofundi is the least specialized, displaying a genomic potential for the utilization of diverse organic substrates. The least abundant species, DL1, is characterized by a preference for catabolism of amino acids, and is the only one species that lacks genes needed for glycerol degradation. Despite the four haloarchaea being distributed throughout the water column, our analyses describe a range of distinctive features, including preferences for substrates that are indicative of ecological niche partitioning. The individual characteristics could be responsible for shaping the composition of the haloarchaeal community throughout the lake by enabling selection of ecotypes and maintaining sympatric speciation. PMID:24553470

  6. Culturable diversity of aerobic halophilic archaea (Fam. Halobacteriaceae) from hypersaline, meromictic Transylvanian lakes.

    PubMed

    Baricz, Andreea; Cristea, Adorján; Muntean, Vasile; Teodosiu, Gabriela; Andrei, Adrian-Ştefan; Molnár, Imola; Alexe, Mircea; Rakosy-Tican, Elena; Banciu, Horia Leonard

    2015-03-01

    Perennially stratified salt lakes situated in the Transylvanian Basin (Central Romania) were surveyed for the diversity of culturable halophilic archaea (Fam. Halobacteriaceae). The physical and chemical characteristics of the waters indicated that all the investigated lakes were meromictic and neutral hypersaline. Samples collected from upper, intermediate, and deeper water layers and sediments were used for the isolation of halophilic strains followed by 16S rRNA gene-based identification and phenotypic characterization. The phylogenetic analysis of the 16S rRNA gene sequences revealed that all 191 isolates reported in this study and 43 strains previously isolated were affiliated with the family Halobacteriaceae and classified to 18 genera. Haloferax was the most frequently isolated genus (~47 %), followed by Halobacterium spp. (~12 %), and Halorubrum spp. (~11 %). Highest culturable diversity was detected in Brâncoveanu Lake, the oldest and saltiest of all studied lakes, while the opposite was observed in the most stable and least human-impacted Fără Fund Lake. One strain from Ursu Lake might possibly constitute a novel Halorubrum species as shown by phylogenetic analysis. Several haloarchaeal taxa recently described in Asian (i.e., Iran, China) saline systems were also identified as inhabiting the Transylvanian salt lakes thus expanding our knowledege on the geographic distribution of Halobacteriaceae. PMID:25680859

  7. Tests of proprietary chemical additives as antiscalants for hypersaline geothermal brine. Final report

    SciTech Connect

    Harrar, J.E.; Locke, F.E.; Otto, C.H. Jr.; Deutscher, S.B.; Frey, W.P.; Lorensen, L.E.; Snell, E.O.; Lim, R.; Ryon, R.W.; Quong, R.

    1980-01-01

    The Lawrence Livermore Laboratory brine treatment test system has been used to carry out a short-term evaluation of a number of proprietary chemical additives as antiscalants for the hypersaline brine of the Salton Sea Geothermal Field. In addition, a test of sludge seeding was conducted as a technique for scale control. The effect of each additive on the rate of precipitation of silica from the effluent brine at 90/sup 0/C was measured, and scaling rates of brine treated with nine of the additives were measured at 125 and 210/sup 0/C. Corrosion rates of mild steel in the treated brines were estimated using Petrolite linear polarization resistance equipment. None of the additives had a direct effect on the rates of silica precipitation, and none had a beneficial effect on the scale formed at 210/sup 0/C. At 125/sup 0/C, two additives, Drewsperse 747 (Drew Chemical) and SC-210 (Southwest Specialty Chemicals) afforded a marginal degree of scale reduction. The Austral-Erwin additive diminished the adherence of scale formed at points of high velocity fluid flow but increased solids accumulation at other points. Sludge seeding shows some promise because it reduces the degree of silica supersaturation of the brine. Results of analyses of solids precipitated from effluent brines (Woolsey No. 1 and acidified Magmamax No. 1) are presented.

  8. Microbial Diversity of the Hypersaline Sidi Ameur and Himalatt Salt Lakes of the Algerian Sahara

    PubMed Central

    Boutaiba, Saad; Hacene, Hocine; Bidle, Kelly A.; Maupin-Furlow, Julie A.

    2011-01-01

    Microbial populations within hypersaline lakes often exhibit high activities of photosynthesis, dissimilatory sulphate reduction and other processes and, thus, can have profound impacts on biogeochemical cycles of carbon, nitrogen, sulphur and other important elements within arid lands. To further understand these types of ecosystems, the physicochemical and biological properties of Sidi Ameur and Himalatt Salt Lakes in the Algerian Sahara were examined and compared. Both lakes were relatively neutral in pH (7.2 to 7.4) and high in salt, at 12% and 20 % (w/v) salinity for Himalatt and Sidi Ameur Lakes, respectively, with dominant ions of sodium and chloride. The community compositions of microbes from all three domains (Bacteria, Archaea and Eukarya) were surveyed through the use of 16S and 18S ribosomal gene amplification and clone library clustering using amplified ribosomal DNA restriction analysis (ARDRA) in conjunction with DNA sequencing and analysis. A high level of microbial diversity, particularly among the bacteria of the Himalatt Salt Lake and archaea of Sidi Ameur Lake, was found within these environments. Representatives from all known halophilic bacterial phyla as well as 6 different genera of halophilic archaea were identified. Moreover, several apparently novel phylotypes among both archaea and bacteria were revealed. PMID:21909172

  9. Low viral predation pressure in cold hypersaline Arctic sediments and limits on lytic replication.

    PubMed

    Colangelo-Lillis, Jesse; Wing, Boswell A; Whyte, Lyle G

    2016-04-01

    Viruses are ubiquitous drivers of microbial ecology and evolution and contribute to biogeochemical cycling. Attention to these attributes has been more substantial for marine viruses than viruses of other environments. Microscopy-based investigation of the viral communities from two cold, hypersaline Arctic springs was undertaken to explore the effects of these conditions on microbe-viral ecology. Sediments and water samples were collected along transects from each spring, from anoxic spring outlets through oxygenated downstream channels. Viral abundance, virus-microbe ratios and modelled virus-microbe contact rates were lower than comparable aqueous and sedimentary environments and most similar to deep subsurface sediments. No individual cell from either spring was visibly infected. Viruses in these springs appear to play a smaller role in controlling microbial populations through lytic activity than in marine water column or surface sedimentary environments. Relief from viral predation indicates the microbial communities are primarily controlled by nutrient limitation. The similarity of these springs to deep subsurface sediments suggests a biogeographic divide in viral replication strategy in marine sediments. PMID:26743115

  10. Metabolic shifts in hypersaline microbial mats upon addition of organic substrates.

    PubMed

    Grötzschel, Stefan; Abed, Raeid M M; de Beer, Dirk

    2002-11-01

    The responses of hypersaline microbial mats to the addition of acetate, glycolate or glucose were investigated using oxygen, pH and sulphide microsensors. Changes in community structure were investigated with molecular techniques. Acetate addition inhibited respiration in the photic zone, stimulated respiration in the aphotic zone and had no effect on gross photosynthesis. Glycolate addition strongly increased both respiration and gross photosynthesis in the photic zone. Thus, glycolate and acetate were probably consumed in those regions of the mat where these substrates are usually formed. Moreover, photosynthesis was only stimulated by increased respiration and concomitant CO2 production in the photic zone which indicates that the photosynthetic and respiratory populations must be present in close proximity to each other. Glucose addition had an unexpected negative effect on the microbial population, strongly inhibiting both respiration and gross photosynthesis within hours. After four days, oxygen profiles in the light were equal to those measured in the dark. After replacing the water phase with unamended water, photosynthesis and respiration recovered within a week. None of the physiological changes were accompanied by detectable shifts in the cyanobacterial or the overall microbial community. The mechanism of inhibition of photosynthesis by glucose requires further investigation. PMID:12460276

  11. Environmental selection of protistan plankton communities in hypersaline anoxic deep-sea basins, Eastern Mediterranean Sea.

    PubMed

    Filker, Sabine; Stock, Alexandra; Breiner, Hans-Werner; Edgcomb, Virginia; Orsi, William; Yakimov, Michail M; Stoeck, Thorsten

    2013-02-01

    High salt concentrations, absence of light, anoxia, and high hydrostatic pressure make deep hypersaline anoxic basins (DHABs) in the Eastern Mediterranean Sea one of the most polyextreme habitats on Earth. Taking advantage of the unique chemical characteristics of these basins, we tested the effect of environmental selection and geographic distance on the structure of protistan communities. Terminal restriction fragment length polymorphism (T-RFLP) analyses were performed on water samples from the brines and seawater/brine interfaces of five basins: Discovery, Urania, Thetis, Tyro, and Medee. Using statistical analyses, we calculated the partitioning of diversity among the ten individual terminal restriction fragment (T-RF) profiles, based on peak abundance and peak incidence. While a significant distance effect on spatial protistan patterns was not detected, hydrochemical gradients emerged as strong dispersal barriers that likely lead to environmental selection in the DHAB protistan plankton communities. We identified sodium, magnesium, sulfate, and oxygen playing in concerto as dominant environmental drivers for the structuring of protistan plankton communities in the Eastern Mediterranean DHABs. PMID:23239531

  12. Microbial eukaryote life in the new hypersaline deep-sea basin Thetis.

    PubMed

    Stock, Alexandra; Breiner, Hans-Werner; Pachiadaki, Maria; Edgcomb, Virginia; Filker, Sabine; La Cono, Violetta; Yakimov, Michail M; Stoeck, Thorsten

    2012-01-01

    Only recently, a novel anoxic hypersaline (thalassic) basin in the eastern Mediterranean was discovered at a depth of 3,258 m. The halite-saturated brine of this polyextreme basin revealed one of the highest salt concentrations ever reported for such an environment (salinity of 348‰). Using a eukaryote-specific probe and fluorescence in situ hybridization, we counted 0.6 × 10(4) protists per liter of anoxic brine. SSU rRNA sequence analyses, based on amplification of environmental cDNA identified fungi as the most diverse taxonomic group of eukaryotes in the brine, making deep-sea brines sources of unknown fungal diversity and hotspots for the discovery of novel metabolic pathways and for secondary metabolites. The second most diverse phylotypes are ciliates and stramenopiles (each 20%). The occurrence of closely related ciliate sequences exclusively in other Mediterranean brine basins suggests specific adaptations of the respective organisms to such habitats. Betadiversity-analyses confirm that microeukaryote communities in the brine and the interface are notably different. Several distinct morphotypes in brine samples suggest that the rRNA sequences detected in Thetis brine can be linked to indigenous polyextremophile protists. This contradicts previous assumptions that such extremely high salt concentrations are anathema to eukaryotic life. The upper salinity limits for eukaryotic life remain unidentified. PMID:22009262

  13. Saccharopolyspora halotolerans sp. nov., a halophilic actinomycete isolated from a hypersaline lake.

    PubMed

    Lv, Ling-Ling; Zhang, Yue-Feng; Xia, Zhan-Feng; Zhang, Jing-Jing; Zhang, Li-Li

    2014-10-01

    A novel actinomycete strain, designated TRM 45123(T), was isolated from a hypersaline habitat in Xinjiang Province (40° 20' N 90° 49' E), north-west China. The isolate was characterized using a polyphasic approach. 16S rRNA gene sequence analysis indicated that strain TRM 45123(T) belonged to the genus Saccharopolyspora and was closely related to Saccharopolyspora gloriosae (96.7% similarity). The G+C content of the DNA was 69.07 mol%. The isolate contained meso-diaminopimelic acid as the diagnostic diamino acid, and arabinose and ribose as the major whole-cell sugars. The diagnostic phospholipids were phosphatidylethanolamine, phosphatidylcholine and phosphatidylglycerol. The predominant menaquinone was MK-9(H4). The major fatty acids were iso-C16 : 0, anteiso-C17:0, iso-C15:0 and anteiso-C15:0. On the basis of the evidence from this polyphasic study, a novel species, Saccharopolyspora halotolerans sp. nov., is proposed. The type strain of Saccharopolyspora halotolerans is TRM 45123(T) ( = CCTCC AA 2013006(T) = DSM 45990(T)). PMID:25061064

  14. Amycolatopsis salitolerans sp. nov., a filamentous actinomycete isolated from a hypersaline habitat.

    PubMed

    Guan, Tong-Wei; Xia, Zhan-Feng; Tang, Shu-Kun; Wu, Nan; Chen, Zheng-Jun; Huang, Ying; Ruan, Ji-Sheng; Li, Wen-Jun; Zhang, Li-Li

    2012-01-01

    A novel actinomycete strain, designated TRM F103(T), was isolated from a hypersaline habitat of the Tarim basin in Xinjiang province, north-west China. Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolate belonged to the genus Amycolatopsis and was most closely related to Amycolatopsis halophila YIM 93223(T) (99.3% 16S rRNA gene sequence similarity). However, DNA-DNA relatedness between these two strains, based on triplicate experiments, was only 31.6%. The isolate contained meso-diaminopimelic acid and ribose, glucose and galactose as the major whole-cell sugars. The predominant menaquinone was MK-8(H(4)). The major fatty acids were iso-C(16:0) and C(16:0). The polar lipids were diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine and glucosamine-containing phospholipids. The G+C content of the genomic DNA was 66.4 mol%. The phenotypic data clearly distinguished the isolate from its closest relatives. The combined phylogenetic, chemotaxonomic and phenotypic data indicate that the isolate represents a novel species of the genus Amycolatopsis. The proposed name is Amycolatopsis salitolerans sp. nov., with TRM F103(T) (=JCM 15899(T)=CCTCC AB 208326(T)) as the type strain. PMID:21317279

  15. Assessing the potential of Landsat 8 OLI for retrieving salinity in the hypersaline Arabian Gulf

    NASA Astrophysics Data System (ADS)

    Zhao, Jun; Temimi, Marouane

    2016-04-01

    The Arabian Gulf, located in an arid region in the Middle East, has high salinity that can exceed 43 practical salinity units (psu) due to its special conditions, such as high evaporation, low precipitation, and desalination discharge. In this study, a regional algorithm was developed to retrieve salinity using in situ measurements conducted between June 2013 and November 2014 along the western coast of Abu Dhabi, United Arab Emirates (UAE). A multivariate linear regression model using the visible bands of Operational Land Imager (OLI) was proposed and indicated good performance with a determination coefficient (R2) of 0.7. The algorithm was then applied to an OLI scene, which revealed the spatial distribution of salinity over the study area. The findings are favorable for better interpretation of the complex water mass exchange between the Arabian Gulf and the Sea of Oman through the Strait of Hormuz, validating salinity from numerical models, studying the effects of anthropogenic activities and climate change on ecosystem in the hypersaline Arabian Gulf, etc.

  16. Neutral monosaccharides from a hypersaline tropical environment: Applications to the characterization of modern and ancient ecosystems

    NASA Astrophysics Data System (ADS)

    Moers, M. E. C.; Larter, S. R.

    1993-07-01

    Surficial and buried sediment samples from a hypersaline lagoon-sabkha system (Abu Dhabi, United Arab Emirates) were analysed for carbohydrates (as neutral monosaccharides) to distinguish and characterise various types of recent and ancient tropical ecosystems on a molecular level. The samples consisted of surficial and buried microbial mats, lagoonal sediments containing seagrass ( Halodule uninervis), and mangrove ( Avicennia marina) paleosoils and handpicked mangrove leaves, ranging in age from contemporary to ca. 6000 yr Bp. Analysis of quantitative neutral monosaccharide data by multivariate techniques shows that various groups can be distinguished: intact vascular plant material (mangrove leaf) contains high amounts of arabinose and glucose and hardly any partially methylated monosaccharides, whereas microbial mats in general and lagoonal seagrass sediments show high contributions of fucose, ribose, mannose, galactose and partially methylated monosaccharides. Moreover, surficial microbial mats consisting of filamentous cyanobacteria ( Microcoleus chtonoplastes, Lyngbya aestuarii) can be distinguished from other mats and sediments containing coccoid cyanobacteria ( Entophysalis major) and/or fermenting, sulphate reducing, and methanogenic bacteria on the basis of high contributions of specific groups of partially methylated monosaccharides and other "minor" saccharides. The neutral monosaccharides present in mangrove paleosoils are for a substantial part derived from microorganisms.

  17. Neutral monosaccharides from a hypersaline tropical environment: Applications to the characterization of modern and ancient ecosystems

    SciTech Connect

    Moers, M.E.C.; Larter, S.R. )

    1993-07-01

    Surficial and buried sediment samples from a hypersaline lagoon-sabkha system (Abu Dhabi, United Arab Emirates) were analyzed for carbohydrates (as neutral monosaccharides) to distinguish and characterize various types of recent and ancient tropical ecosystems on a molecular level. The samples consisted of surficial and buried microbial mats, lagoonal sediments containing seagrass (Halodule uninervis), and mangrove (Avicennia marine) paleosoils and handpicked mangrove leaves, ranging in age from contemporary to ca. 6000 yr BP. Analysis of quantitative neutral monosaccharide data by multivariate techniques shows that various groups can be distinguished: intact vascular plant material (mangrove leaf) contains high amounts of arabinose and glucose and hardly any partially methylated monosaccharides, whereas microbial mats in general and lagoonal seagrass sediments show high contributions of fucose, ribose, mannose, galactose, and partially methylated monosaccharides. Moreover, surficial microbial mats consisting of filamentous cyanobacteria (Microcoleus chtonoplastes, Lyngbya aestuarii) can be distinguished from other mats and sediments containing coccoid cyanobacteria (Entophysalis major) and/or fermenting, sulphate reducing, and methanogenic bacteria on the basis of high contributions of specific groups of partially methylated monosaccharides and other [open quotes]minor[close quotes] saccharides. The neutral monosaccharides present in mangrove paleosoils are for a substantial part derived from microorganisms. 22 refs., 4 figs., 4 tabs.

  18. Mineralogy and Microbial Diversity of the Microbialites in the Hypersaline Storr's Lake, the Bahamas.

    PubMed

    Paul, Varun G; Wronkiewicz, David J; Mormile, Melanie R; Foster, Jamie S

    2016-04-01

    Microbialites found in the low-light-intensity, hypersaline waters of Storr's Lake (SL), San Salvador Island, the Bahamas, were investigated with respect to their morphology, mineralogy, and microbial diversity. Previously described microbialite morphologies, as well as a newly identified "multi-cuspate" morphology, were observed at various depths. Electron microscopy analysis revealed the presence of angular, blocky, and needle-shaped crystals with mineralized cyanobacterial filaments and remains of exopolymeric substances. X-ray diffraction studies confirmed the presence of both Mg-calcite and aragonite in the plateau-mushroom and pinnacle mound microbialites, whereas only Mg-calcite was identified in the other microbialite morphotypes. A comprehensive molecular analysis using barcoded pyrosequencing of five different microbial mat communities identified at least 12 dominant bacterial phyla. Cyanobacteria were generally low in abundance and ranged from ∼0.01% in the deeper pinnacle mounds to ∼3.2% in the shallow calcareous knobs. Other photosynthetic members included green nonsulfur bacteria of the phylum Chloroflexi and purple sulfur bacteria of the class Gammaproteobacteria. All mat types contained significant amounts of sulfate-reducing and dehalogenating bacteria. The low light intensity reaching the deeper microbialites, the lack of dominant cyanobacteria, and the abundance of sulfate reducers and Chloroflexi collectively suggest that sulfate reduction and anoxygenic photosynthetic processes influence the carbonate biomineralization process in these systems. PMID:27082142

  19. Archaeal populations in hypersaline sediments underlying orange microbial mats in the Napoli mud volcano.

    PubMed

    Lazar, Cassandre Sara; L'haridon, Stéphane; Pignet, Patricia; Toffin, Laurent

    2011-05-01

    Microbial mats in marine cold seeps are known to be associated with ascending sulfide- and methane-rich fluids. Hence, they could be visible indicators of anaerobic oxidation of methane (AOM) and methane cycling processes in underlying sediments. The Napoli mud volcano is situated in the Olimpi Area that lies on saline deposits; from there, brine fluids migrate upward to the seafloor. Sediments associated with a brine pool and microbial orange mats of the Napoli mud volcano were recovered during the Medeco cruise. Based on analysis of RNA-derived sequences, the "active" archaeal community was composed of many uncultured lineages, such as rice cluster V or marine benthic group D. Function methyl coenzyme M reductase (mcrA) genes were affiliated with the anaerobic methanotrophic Archaea (ANME) of the ANME-1, ANME-2a, and ANME-2c groups, suggesting that AOM occurred in these sediment layers. Enrichment cultures showed the presence of viable marine methylotrophic Methanococcoides in shallow sediment layers. Thus, the archaeal community diversity seems to show that active methane cycling took place in the hypersaline microbial mat-associated sediments of the Napoli mud volcano. PMID:21335391

  20. Geochemistry of dissolved gases in the hypersaline Orca basin. Technical report

    SciTech Connect

    Wiesenburg, D.A.

    1980-12-01

    Hypersaline, anoxic waters significantly affect the biogeochemistry of dissolved gases in the Orca Basin (Northern Gulf of Mexico). The high stability of the Orca brine pool makes it an ideal laboratory for studying production and consumption of dissolved gases during anaerobic decomposition. Depth distributions were determined for nitrogen, oxygen, argon, methane, ethane, propane, ammonia, hydrogen sulfide, and nitrous oxide. Physical stratification of the water column strongly influences Orca Basin gas distributions. The high salinity brine (approx. 250%) is internally well mixed due to convective overturning, but transfer across the brine-sea water interface is controlled by molecular diffusion. With a molecular diffusivity of 0.00001 sq cm/sec, it will take 1,000,000 years for all salts to diffuse from the basin. Heat diffuses faster than salt and is lost from the basin at a rate of 0.5 microcal sq cm/sec. If geothermal heat input from the sediments is slightly higher, this input could account for the higher temperature in the brine (5.6C) compared to the deep Gulf waters (4.2 C). This study has shown the utility of dissolved gases in examining water chemistry of unusual areas. Since sources of dissolved gases are independent of the sources of major ions in solution, calculations of gas distributions on a salt-free basis are useful in examining production and consumption processes.

  1. MONO FOR CROSS-PLATFORM CONTROL SYSTEM ENVIRONMENT

    SciTech Connect

    Nishimura, Hiroshi; Timossi, Chris

    2006-10-19

    Mono is an independent implementation of the .NET Frameworkby Novell that runs on multiple operating systems (including Windows,Linux and Macintosh) and allows any .NET compatible application to rununmodified. For instance Mono can run programs with graphical userinterfaces (GUI) developed with the C# language on Windows with VisualStudio (a full port of WinForm for Mono is in progress). We present theresults of tests we performed to evaluate the portability of our controlssystem .NET applications from MS Windows to Linux.

  2. Self-excited mono-ion oscillator.

    PubMed

    Dehmelt, H; Nagourney, W; Sandberg, J

    1986-08-01

    We propose self-excitation as a potentially more sensitive technique for studying a mono-ion oscillator of frequency v(z) approximately 0.1-100 MHz. This technique also makes only low demands on the harmonicity of the ion oscillation. It should therefore work with inexpensive, easily constructed rf traps. In our analysis, the bound ion between the trap electrodes is represented by an effective circuit resembling that of a piezoelectric quartz crystal. The feedback circuit developed, when operated below self-excitation threshold, may also make efficient electronic cooling of the ion possible, particularly in conjunction with a heterodyne feedback scheme. In the super-regenerative mode, the apparatus might function as a powerful atomic amplifier of the ion oscillation for an energy as low as a fraction of hv(z). These techniques may prove especially useful in conjunction with attempts to synthesize in an rf trap a loosely bound anti-hydrogen atom from a positron and antiproton. PMID:16593742

  3. Travertine Hot Springs, Mono County, California

    SciTech Connect

    Chesterman, C.W.; Kleinhampl, F.J.

    1991-08-01

    This article is an abridgement of Special Report 172, Travertine Hot Springs at Bridgeport, Mono County, California, in preparation at the California Division of Mines and Geology. The Travertine Hot Springs area is on the northern edge of what many consider to be one of the most tectonically active areas in the United States. There is abundant geothermal and seismic activity. The landscape is dotted with volcanic features- cones, craters, domes, flows, fumaroles and hot springs-indicators of unrest in the present as well as reminders of activity in the past. Travertine, also known as calcareous sinter, is limestone formed by chemical precipitation of calcium carbonate (CaCO{sub 3}) from ground or surface waters. It forms stalactites and stalagmites in caves, fills some veins and spring conduits and can also be found at the mouths of springs, especially hot springs. The less compact variety is called tufa and the dense, banded variety is known as Mexican onyx, or onyx marble. True onyx, however, is a banded silicate.

  4. Organic geochemistry and brine composition in Great Salt, Mono, and Walker Lakes

    SciTech Connect

    Domagalski, J.L.; Orem, W.H.; Eugster, H.P.

    1989-01-01

    Samples of recent sediments, representing up to 1,000 years of accumulation, were collected from three closed basin lakes to assess the effects of brine composition on the accumulation of effects of brine composition on the accumulation of total organic carbon, the concentration of dissolved organic carbon, humic acid structure and diagenesis, and trace metal complexation. The Great Salt Lake water column is a stratified Na-Mg-Cl-SO{sub 4} brine with low alkalinity. Algal debris is entrained in the high density (1.132-1.190 g/ml) bottom brines, and in this region maximum organic matter decomposition occurs by anaerobic processes, with sulfate ion as the terminal electron acceptor. Organic matter, below 5 cm of the sediment-water interface, degrades at a very slow rate in spite of very high pore-fluid sulfate levels. Mono Lake is an alkaline (Na-CO{sub 3}-Cl-SO{sub 4}) system. The water column is stratified, but the bottom brines are of lower density relative to the Great Salt Lake, and sedimentation of algal debris is rapid. Walker Lake is also an alkaline system. The water column is not stratified, and decomposition of organic matter occurs by aerobic processes at the sediment-water interface and by anaerobic processes below. Total organic carbon and dissolved organic carbon concentrations in Walker Lake sediments vary with location and depth due to changes in input and pore-fluid sulfate concentrations. Nuclear magnetic resonance studies of humic substances and dissolved organic carbon provide information on the source of the recent sedimentary organic carbon, its relative state of decomposition, and its chemical structure. 44 refs., 10 figs., 6 tabs.

  5. Resistivity Imaging of the Mono-Inyo Volcanic Chain, Mono Basin, California Using the Audiomagnetotelluric Method

    NASA Astrophysics Data System (ADS)

    McPhee, D. K.; Ponce, D. A.; Pera McDonell, A.; Chuchel, B. A.

    2011-12-01

    Audiomagnetotelluric (AMT) models of data collected in Mono Basin, California show significant structure within the upper kilometer of the basin and image a shallow resistor that may be related to a shallow basement feature. The Mono-Inyo volcanic chain is a 25-km long, north-south trending series of domes and craters extending southward from Mono Lake and into the western part of the Long Valley Caldera. Gravity and magnetic modeling in the region, prompted by a volcano hazards study, show a basement high associated with an apparent circular magnetic anomaly. AMT data are used to further investigate this potential field anomaly and image the geoelectric structure within the volcanic rocks in Mono Basin. We collected AMT data along two profiles in Pumice Valley and along the western margin of the domes. Profile A runs approximately east-west, perpendicular to the regional geologic strike, and extends 2.5 km from the southern edge of North Coulee into the basin. Profile B is a north-south trending 6 km-long profile within the basin and was located several hundred meters away from the volcanic chain. Both profiles perpendicularly intersect the circular magnetic feature. We computed both one-dimensional and two-dimensional (2D) inverse models along each profile. 2D models were computed using the conjugate gradient, finite-difference method of Rodi and Mackie (2001) and a 100 ohm-m half-space, starting model. One-dimensional model sensitivity and various 2D starting models indicate a depth of investigation of about 1 km. Preliminary models show a relatively conductive (~20 ohm-m) volcanic basin fill likely associated with the Bishop Tuff, a voluminous pyroclastic flow, whose eruption resulted in formation of the Long Valley caldera 760 Ka ago. Resistivity variations within the basin fill may be related to the porosity or amount of fracturing of individual flows. A resistive (> 200 ohm-m) feature at roughly 600-800 m depth coincides with the magnetic high and relative

  6. Magmatic gas emissions at Holocene volcanic features near Mono Lake, California, and their relation to regional magmatism

    USGS Publications Warehouse

    Bergfeld, D.; Evans, William C.; Howle, James F.; Hunt, Andrew G.

    2015-01-01

    Silicic lavas have erupted repeatedly in the Mono Basin over the past few thousand years, forming the massive domes and coulees of the Mono Craters chain and the smaller island vents in Mono Lake. We report here on the first systematic study of magmatic CO2 emissions from these features, conducted during 2007–2010. Most notably, a known locus of weak steam venting on the summit of North Coulee is actually enclosed in a large area (~ 0.25 km2) of diffuse gas discharge that emits 10–14 t/d of CO2, mostly at ambient temperature. Subsurface gases sampled here are heavily air-contaminated, but after standard corrections are applied, show average δ13C-CO2 of − 4.72‰, 3He/4He of 5.89RA, and CO2/3He of 0.77 × 1010, very similar to the values in fumarolic gas from Mammoth Mountain and the Long Valley Caldera immediately to the south of the basin. If these values also characterize the magmatic gas source at Mono Lake, where CO2 is captured by the alkaline lake water, a magmatic CO2 upflow beneath the lake of ~ 4 t/d can be inferred. Groundwater discharge from the Mono Craters area transports ~ 13 t/d of 14C-dead CO2 as free gas and dissolved carbonate species, and adding in this component brings the estimated total magmatic CO2 output to 29 t/d for the two silicic systems in the Mono Basin. If these emissions reflect intrusion and degassing of underlying basalt with 0.5 wt.% CO2, a modest intrusion rate of 0.00075 km3/yr is indicated. Much higher intrusion rates are required to account for CO2 emissions from Mammoth Mountain and the West Moat of the Long Valley Caldera.

  7. RECLAMATION OF ALKALINE ASH PILES

    EPA Science Inventory

    The objective of the study was to develop methods for reclaiming ash disposal piles for the ultimate use as agricultural or forest lands. The ashes studied were strongly alkaline and contained considerable amounts of salts and toxic boron. The ashes were produced from burning bit...

  8. Plutonium speciation in water from Mono Lake, California

    USGS Publications Warehouse

    Cleveland, J.M.; Rees, T.F.; Nash, K.L.

    1983-01-01

    The solubility of plutonium in Mono Lake water is enhanced by the presence of large concentrations of indigenous carbonate ions and moderate concentrations of fluoride ions. In spite of the complex chemical composition of this water, only a few ions govern the behavior of plutonium, as demonstrated by the fact that it was possible to duplicate plutonium speciation in a synthetic water containing only the principal components of Mono Lake water.

  9. Eco-morphological differentiation in Lake Magadi tilapia, an extremophile cichlid fish living in hot, alkaline and hypersaline lakes in East Africa.

    PubMed

    Kavembe, Geraldine D; Kautt, Andreas F; Machado-Schiaffino, Gonzalo; Meyer, Axel

    2016-04-01

    Ecological diversification through divergent selection is thought to be a major force during the process of adaptive radiations. However, the large sizes and complexity of most radiations such as those of the cichlids in the African Great Lakes make it impossible to infer the exact evolutionary history of any population divergence event. The genus Alcolapia, a small cichlid lineage endemic to Lakes Magadi and Natron in East Africa, exhibits phenotypes similar to some of those found in cichlids of the radiations of the African Great Lakes. The simplicity within Alcolapia makes it an excellent model system to investigate ecological diversification and speciation. We used an integrated approach including population genomics based on RAD-seq data, geometric morphometrics and stable isotope analyses to investigate the eco-morphological diversification of tilapia in Lake Magadi and its satellite lake Little Magadi. Additionally, we reconstructed the demographic history of the species using coalescent simulations based on the joint site frequency spectrum. The population in Little Magadi has a characteristically upturned mouth--possibly an adaptation to feeding on prey from the water surface. Eco-morphological differences between populations within Lake Magadi are more subtle, but are consistent with known ecological differences between its lagoons such as high concentrations of nitrogen attributable to extensive guano deposits in Rest of Magadi relative to Fish Springs Lagoon. All populations diverged simultaneously only about 1100 generations ago. Differences in levels of gene flow between populations and the effective population sizes have likely resulted in the inferred heterogeneous patterns of genome-wide differentiation. PMID:26547282

  10. Metagenome sequencing of the prokaryotic microbiota of the hypersaline and meromictic soap lake, washington.

    PubMed

    Hawley, Erik R; Hess, Matthias

    2014-01-01

    Soap Lake is a small saline lake in central eastern Washington that is sharply stratified into two layers. In addition to being highly alkaline (~pH 10), Soap Lake also contains high concentrations of sulfide. Here, we report the community profile of the prokaryotic microbiota associated with Soap Lake surface water. PMID:24459273

  11. Isolation of alkaline mutagens from complex mixtures

    SciTech Connect

    Ho, C.H.; Guerin, M.R.; Clark, B.R.; Rao, T.K.; Epler, J.L.

    1981-05-01

    A method for the preparative-scale enrichment of alkaline mutagens from complex natural and anthropogenic mixtures is described. Mutagenic alkaline fractions were isolated from cigarette smoke, crude petroleum, and petroleum substitutes derived from coal and shale.

  12. The geomorphology of two hyper-saline springs in the Canadian High Arctic

    NASA Astrophysics Data System (ADS)

    Ward, M. K.; Pollard, W. H.

    2013-12-01

    On Axel Heiberg Island in the Canadian High Arctic a number of low temperature perennial saline springs occur despite being subject to a cold polar desert climate with a mean annual air temperature of -18°C. Associated with 2 groups of hyper-saline springs are distinctive landforms resulting from winter deposition of salt minerals. These deposits resemble tufas structurally but unlike true tufas which are composed of carbonate minerals, these landforms are formed mainly of salt. This study hypothesizes that the extreme cold winter air temperatures cools water temperatures triggering rapid precipitation of various salt minerals (mainly hydrohalite, NaCl*2H2O) which subsequently alters the flow hydrology by obstructing summer flow paths. The tufa-like appearance of these salt deposits reflects the interaction between changing water temperature, chemistry and flow. This research characterises the geomorphology and geochemistry of two hyper-saline springs on Axel Heiberg Island: the first is located at Wolf Diapir (79°07'23'N; 90°14'39'W), the deposit at this site resembles a large conical mound (2.5m tall x 3m diameter). The second is located at Stolz Diapir (79°04'30'N; 87°04'30'W), in this case a series of pool and barrage structures staircase down a narrow valley for approximately 300m (several pools are 10 m wide x 3 m deep). The springs have very different seasonal surface hydrologic regimes and topographic settings which influence the pattern of mineral precipitates. The accumulation of precipitates occurs during the winter and is dominated by the formation of hydrohalite. In the summer, the accumulated hydrohalite melts incongruently to form halite; spring water and snowmelt dissolves various parts of the accumulations, changing the morphology of the deposits. The aim of this poster is to present preliminary observations characterising the processes driving tufa formation in a permafrost environment, a process that has not been described in detail in

  13. Exploration of Microbial Diversity and Community Structure of Lonar Lake: The Only Hypersaline Meteorite Crater Lake within Basalt Rock.

    PubMed

    Paul, Dhiraj; Kumbhare, Shreyas V; Mhatre, Snehit S; Chowdhury, Somak P; Shetty, Sudarshan A; Marathe, Nachiket P; Bhute, Shrikant; Shouche, Yogesh S

    2015-01-01

    Lonar Lake is a hypersaline and hyperalkaline soda lake and the only meteorite impact crater in the world situated in basalt rocks. Although culture-dependent studies have been reported, a comprehensive understanding of microbial community composition and structure in Lonar Lake remains elusive. In the present study, microbial community structure associated with Lonar Lake sediment and water samples was investigated using high-throughput sequencing. Microbial diversity analysis revealed the existence of diverse, yet largely consistent communities. Proteobacteria (30%), Actinobacteria (24%), Firmicutes (11%), and Cyanobacteria (5%) predominated in the sequencing survey, whereas Bacteroidetes (1.12%), BD1-5 (0.5%), Nitrospirae (0.41%), and Verrucomicrobia (0.28%) were detected in relatively minor abundances in the Lonar Lake ecosystem. Within the Proteobacteria phylum, the Gammaproteobacteria represented the most abundantly detected class (21-47%) within sediment samples, but only a minor population in the water samples. Proteobacteria and Firmicutes were found at significantly higher abundance (p ≥ 0.05) in sediment samples, whereas members of Actinobacteria, Candidate division TM7 and Cyanobacteria (p ≥ 0.05) were significantly abundant in water samples. Compared to the microbial communities of other hypersaline soda lakes, those of Lonar Lake formed a distinct cluster, suggesting a different microbial community composition and structure. Here we report for the first time, the difference in composition of indigenous microbial communities between the sediment and water samples of Lonar Lake. An improved census of microbial community structure in this Lake ecosystem provides a foundation for exploring microbial biogeochemical cycling and microbial function in hypersaline lake environments. PMID:26834712

  14. Wind effects on prey availability: How northward migrating waders use brackish and hypersaline lagoons in the sivash, Ukraine

    NASA Astrophysics Data System (ADS)

    Verkuil, Yvonne; Koolhaas, Anita; Van Der Winden, Jan

    Large numbers of waders migrating northward in spring use the Sivash, a large system of shallow, brackish and hypersaline lagoons in the Black Sea and Azov Sea region (Ukraine). The bottoms of these lagoons are often uncovered by the wind. Hence, for waders the time and space available for feeding depend on wind conditions. In hypersaline lagoons the benthic and pelagic fauna was very poor, consisting mainly of chironomid larvae (0.19 g AFDM·m -2) and brine shrimps Artemia salina, respectively. Brine shrimp abundance was correlated with salinity, wind force, wind direction and water depth. Dunlin Calidris alpina and curlew sandpiper Calidris ferruginea were the only species feeding on brine shrimp. As brine shrimp densities are higher in deeper water, smaller waders such as broad-billed sandpipers Limicola falcinellus are too short-legged to reach exploitable densities of brine shrimp. In brackish lagoons the benthic and pelagic fauna was rich, consisting of polychaetes, bivalves, gastropods, chironomid larvae, isopods and amphipods (8.9 to 30.5 g AFDM·m -2), but there were no brine shrimps. Prey biomass increased with the distance from the coast, being highest on the site that was most frequently inundated. Dunlin, broad-billed sandpiper and grey plover Pluvialis squatarola were the most abundant birds in the brackish lagoon. Due to the effects of wind-tides only a small area was usually available as a feeding site. Gammarus insensibilis was the alternative prey resource in the water layer, and their density varied with wind direction in the same way as brine shrimp. Curlew sandpipers and dunlins in the hypersaline lagoons and broad-billed sandpipers in the brackish lagoons often changed feeding sites, probably following the variation in prey availability. Only because of the large size and variety of lagoons are waders in the Sivash always able to find good feeding sites.

  15. Microbial Mg-carbonate Precipitation and Early Diagenetic Dolomite Crust Formation at Hypersaline Lagoon, Rio de Janeiro State, Brazil.

    NASA Astrophysics Data System (ADS)

    Bahniuk Rumbelsperger, A. M.; McKenzie, J. A.; Perri, E.; Vögeli, N.; Vasconcelos, C.

    2015-12-01

    Sedimentary dolomite rocks are commonly considered to be primarily a replacement product of the calcium carbonate components comprising the original limestone, a process known as secondary replacement dolomitization. Although numerous dolomite formations in the geologic record are composed of fine-grained crystals of micritic dolomite, an alternative process, i.e., direct precipitation, is often excluded because of the absence of visible or geochemical indicators supporting primary precipitation. We present a study of a modern coastal hypersaline lagoon, Brejo do Espinho, Rio de Janeiro State, Brazil, which is located in a special climatic regime where a well-defined seasonal cycle of wet and dry conditions occur. The direct precipitation of modern high-Mg calcite and Ca-dolomite mud from the lagoonal waters under low-temperature hypersaline conditions is associated with the activity of microbial organisms living in this restricted environment. The mud undergoes an early diagenetic transformation into a 100% dolomite crust on the margins of the lagoon. The biomineralization process, characterized by the variations of the physico-chemical conditions in this environment during the annual hydrologic cycle, is integrated with isotopic analysis to define the early diagenetic processes responsible for the formation of both dolomitic mud and crust. The carbon isotope values indicate a contribution of respired organic carbon, which is greater for the crust (δ13C = -9.5‰ VPDB) than mud (δ13C = -1.2‰ VPDB). The oxygen isotope values reflect a moderate degree of evaporation during mud formation (δ18O = 1.1‰ VPDB), whereas it is greatly enhanced during early diagenetic crust formation (δ18O = 4.2‰ VPDB). The clumped isotope formation temperatures derived for the Brejo do Espinho mud is 34°C and 32°C for the crust. These temperatures are consistent with the upper range of measured values during the dry season when the lagoon experiences the most hypersaline

  16. Exploration of Microbial Diversity and Community Structure of Lonar Lake: The Only Hypersaline Meteorite Crater Lake within Basalt Rock

    PubMed Central

    Paul, Dhiraj; Kumbhare, Shreyas V.; Mhatre, Snehit S.; Chowdhury, Somak P.; Shetty, Sudarshan A.; Marathe, Nachiket P.; Bhute, Shrikant; Shouche, Yogesh S.

    2016-01-01

    Lonar Lake is a hypersaline and hyperalkaline soda lake and the only meteorite impact crater in the world situated in basalt rocks. Although culture-dependent studies have been reported, a comprehensive understanding of microbial community composition and structure in Lonar Lake remains elusive. In the present study, microbial community structure associated with Lonar Lake sediment and water samples was investigated using high-throughput sequencing. Microbial diversity analysis revealed the existence of diverse, yet largely consistent communities. Proteobacteria (30%), Actinobacteria (24%), Firmicutes (11%), and Cyanobacteria (5%) predominated in the sequencing survey, whereas Bacteroidetes (1.12%), BD1-5 (0.5%), Nitrospirae (0.41%), and Verrucomicrobia (0.28%) were detected in relatively minor abundances in the Lonar Lake ecosystem. Within the Proteobacteria phylum, the Gammaproteobacteria represented the most abundantly detected class (21–47%) within sediment samples, but only a minor population in the water samples. Proteobacteria and Firmicutes were found at significantly higher abundance (p ≥ 0.05) in sediment samples, whereas members of Actinobacteria, Candidate division TM7 and Cyanobacteria (p ≥ 0.05) were significantly abundant in water samples. Compared to the microbial communities of other hypersaline soda lakes, those of Lonar Lake formed a distinct cluster, suggesting a different microbial community composition and structure. Here we report for the first time, the difference in composition of indigenous microbial communities between the sediment and water samples of Lonar Lake. An improved census of microbial community structure in this Lake ecosystem provides a foundation for exploring microbial biogeochemical cycling and microbial function in hypersaline lake environments. PMID:26834712

  17. Diversity and Stratification of Archaea in a Hypersaline Microbial Mat▿ †

    PubMed Central

    Robertson, Charles E.; Spear, John R.; Harris, J. Kirk; Pace, Norman R.

    2009-01-01

    The Guerrero Negro (GN) hypersaline microbial mats have become one focus for biogeochemical studies of stratified ecosystems. The GN mats are found beneath several of a series of ponds of increasing salinity that make up a solar saltern fed from Pacific Ocean water pumped from the Laguna Ojo de Liebre near GN, Baja California Sur, Mexico. Molecular surveys of the laminated photosynthetic microbial mat below the fourth pond in the series identified an enormous diversity of bacteria in the mat, but archaea have received little attention. To determine the bulk contribution of archaeal phylotypes to the pond 4 study site, we determined the phylogenetic distribution of archaeal rRNA gene sequences in PCR libraries based on nominally universal primers. The ratios of bacterial/archaeal/eukaryotic rRNA genes, 90%/9%/1%, suggest that the archaeal contribution to the metabolic activities of the mat may be significant. To explore the distribution of archaea in the mat, sequences derived using archaeon-specific PCR primers were surveyed in 10 strata of the 6-cm-thick mat. The diversity of archaea overall was substantial albeit less than the diversity observed previously for bacteria. Archaeal diversity, mainly euryarchaeotes, was highest in the uppermost 2 to 3 mm of the mat and decreased rapidly with depth, where crenarchaeotes dominated. Only 3% of the sequences were specifically related to known organisms including methanogens. While some mat archaeal clades corresponded with known chemical gradients, others did not, which is likely explained by heretofore-unrecognized gradients. Some clades did not segregate by depth in the mat, indicating broad metabolic repertoires, undersampling, or both. PMID:19114531

  18. Dynamic Viral Populations in Hypersaline Systems as Revealed by Metagenomic Assembly

    PubMed Central

    Thomas, Brian C.; Andrade, Karen; Allen, Eric E.; Heidelberg, Karla B.; Banfield, Jillian F.

    2012-01-01

    Viruses of the Bacteria and Archaea play important roles in microbial evolution and ecology, and yet viral dynamics in natural systems remain poorly understood. Here, we created de novo assemblies from 6.4 Gbp of metagenomic sequence from eight community viral concentrate samples, collected from 12 h to 3 years apart from hypersaline Lake Tyrrell (LT), Victoria, Australia. Through extensive manual assembly curation, we reconstructed 7 complete and 28 partial novel genomes of viruses and virus-like entities (VLEs, which could be viruses or plasmids). We tracked these 35 populations across the eight samples and found that they are generally stable on the timescale of days and transient on the timescale of years, with some exceptions. Cross-detection of the 35 LT populations in three previously described haloviral metagenomes was limited to a few genes, and most previously sequenced haloviruses were not detected in our samples, though 3 were detected upon reducing our detection threshold from 90% to 75% nucleotide identity. Similar results were obtained when we applied our methods to haloviral metagenomic data previously reported from San Diego, CA: 10 contigs that we assembled from that system exhibited a variety of detection patterns on a timescale of weeks to 1 month but were generally not detected in LT. Our results suggest that most haloviral populations have a limited or, possibly, a temporally variable global distribution. This study provides high-resolution insight into viral biogeography and dynamics and it places “snapshot” viral metagenomes, collected at a single time and location, in context. PMID:22773627

  19. Mathematical simulation of the diel O, S, and C biogeochemistry of a hypersaline microbial mat

    NASA Astrophysics Data System (ADS)

    Decker, K.; Potter, C.

    2003-12-01

    The creation of a mathematical simulation model of photosynthetic microbial mats is an important step in our understanding of key biogeochemical cycles that may have altered the atmospheres of early Earth and of other terrestrial planets. A modeling investigation is presented here as a tool to utilize and integrate empirical results from research on hypersaline mats from Baja California, Mexico into a computational system that can be used to simulate biospheric inputs of trace gases to the atmosphere. An early version of our model calculates fluxes and cycling of oxygen, sulfide, and dissolved inorganic carbon (DIC) via abiotic components and via the major bacterial guilds: cyanobacteria (CYA), sulfur reducing bacteria (SRB), purple sulfur bacteria (PSB) and colorless sulfur bacteria (CSB). We used generalized monod-type equations that incorporate substrate and energy limits upon maximum rates of metabolic processes such as photosynthesis and sulfate reduction. We ran a simulation using temperature and irradiance inputs from data collected from a microbial mat in Guerrero Negro in Baja Mexico. Model oxygen, sulfide, and DIC results compared well with data collected in the field mats. A divergence from the field data was an initial large negative DIC flux early in the morning and little flux into the mat thereafter in the simulation. We hypothesize that this divergence will be reduced or eliminated if the salinity of the water surrounding the mat were used as an environmental input and as a limit to photosynthesis rates. Salinity levels, organic carbon, methane, methanogens and green nonsulfur bacteria will be added to this model before it is incorporated into a global model to simulate geological time scales.

  20. Seasonal fluctuations in ionic concentrations drive microbial succession in a hypersaline lake community.

    PubMed

    Podell, Sheila; Emerson, Joanne B; Jones, Claudia M; Ugalde, Juan A; Welch, Sue; Heidelberg, Karla B; Banfield, Jillian F; Allen, Eric E

    2014-05-01

    Microbial community succession was examined over a two-year period using spatially and temporally coordinated water chemistry measurements, metagenomic sequencing, phylogenetic binning and de novo metagenomic assembly in the extreme hypersaline habitat of Lake Tyrrell, Victoria, Australia. Relative abundances of Haloquadratum-related sequences were positively correlated with co-varying concentrations of potassium, magnesium and sulfate, but not sodium, chloride or calcium ions, while relative abundances of Halorubrum, Haloarcula, Halonotius, Halobaculum and Salinibacter-related sequences correlated negatively with Haloquadratum and these same ionic factors. Nanohaloarchaea and Halorhabdus-related sequence abundances were inversely correlated with each other, but not other taxonomic groups. These data, along with predicted gene functions from nearly-complete assembled population metagenomes, suggest different ecological phenotypes for Nanohaloarchaea and Halorhabdus-related strains versus other community members. Nucleotide percent G+C compositions were consistently lower in community metagenomic reads from summer versus winter samples. The same seasonal G+C trends were observed within taxonomically binned read subsets from each of seven different genus-level archaeal groups. Relative seasonal abundances were also linked to percent G+C for assembled population genomes. Together, these data suggest that extreme ionic conditions may exert selective pressure on archaeal populations at the level of genomic nucleotide composition, thus contributing to seasonal successional processes. Despite the unavailability of cultured representatives for most of the organisms identified in this study, effective coordination of physical and biological measurements has enabled discovery and quantification of unexpected taxon-specific, environmentally mediated factors influencing microbial community structure. PMID:24335829

  1. Halorubrum persicum sp. nov., an extremely halophilic archaeon isolated from sediment of a hypersaline lake.

    PubMed

    Corral, Paulina; de la Haba, Rafael R; Sánchez-Porro, Cristina; Amoozegar, Mohammad Ali; Papke, R Thane; Ventosa, Antonio

    2015-06-01

    An extremely halophilic archaeon belonging to the genus Halorubrum, strain C49T, was isolated from sediment of the hypersaline lake Aran-Bidgol in Iran. Phylogenetic analysis based on 16S rRNA gene sequence similarities showed that strain C49T was closely related to Halorubrum saccharovorum JCM 8865T (99.5 %) and other species of the genus Halorubrum. Studies based on multilocus sequence analysis revealed that strain C49T is placed among the species of Halorubrum; the strain constituted a defined branch in comparison with the type strains of species of Halorubrum, while the 16S rRNA gene sequence divergence could not define the status of the newly isolated strain. For optimum growth, strain C49T required 20 % (w/v) salts at pH 7.0 and 37 °C under aerobic conditions. Mg2+ was not required. The cells were pleomorphic rods, motile and stained Gram-variable. Colonies of the strain were pink. Hypotonic treatment with <12 % NaCl provoked cell lysis. The polar lipid pattern of strain C49T consisted of phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester derived from both C20C20 and C20C25 archaeol, phosphatidylglycerol sulfate and sulfated mannosyl glucosyl diether. The DNA G+C content was 64.2 mol%. DNA-DNA hybridization studies and average nucleotide identity confirmed that strain C49T constitutes a distinct genospecies. Data obtained in this study show that strain C49T represents a novel species, for which the name Halorubrum persicum sp. nov. is proposed. The type strain is C49T ( = IBRC-M 10232T = JCM 30541T). PMID:25744586

  2. Seasonal fluctuations in ionic concentrations drive microbial succession in a hypersaline lake community

    PubMed Central

    Podell, Sheila; Emerson, Joanne B; Jones, Claudia M; Ugalde, Juan A; Welch, Sue; Heidelberg, Karla B; Banfield, Jillian F; Allen, Eric E

    2014-01-01

    Microbial community succession was examined over a two-year period using spatially and temporally coordinated water chemistry measurements, metagenomic sequencing, phylogenetic binning and de novo metagenomic assembly in the extreme hypersaline habitat of Lake Tyrrell, Victoria, Australia. Relative abundances of Haloquadratum-related sequences were positively correlated with co-varying concentrations of potassium, magnesium and sulfate, but not sodium, chloride or calcium ions, while relative abundances of Halorubrum, Haloarcula, Halonotius, Halobaculum and Salinibacter-related sequences correlated negatively with Haloquadratum and these same ionic factors. Nanohaloarchaea and Halorhabdus-related sequence abundances were inversely correlated with each other, but not other taxonomic groups. These data, along with predicted gene functions from nearly-complete assembled population metagenomes, suggest different ecological phenotypes for Nanohaloarchaea and Halorhabdus-related strains versus other community members. Nucleotide percent G+C compositions were consistently lower in community metagenomic reads from summer versus winter samples. The same seasonal G+C trends were observed within taxonomically binned read subsets from each of seven different genus-level archaeal groups. Relative seasonal abundances were also linked to percent G+C for assembled population genomes. Together, these data suggest that extreme ionic conditions may exert selective pressure on archaeal populations at the level of genomic nucleotide composition, thus contributing to seasonal successional processes. Despite the unavailability of cultured representatives for most of the organisms identified in this study, effective coordination of physical and biological measurements has enabled discovery and quantification of unexpected taxon-specific, environmentally mediated factors influencing microbial community structure. PMID:24335829

  3. Impact of solar radiation on bacterioplankton in Laguna Vilama, a hypersaline Andean lake (4650 m)

    NASA Astrophysics Data System (ADS)

    FaríAs, MaríA. Eugenia; FernáNdez-Zenoff, Verónica; Flores, Regina; OrdóñEz, Omar; EstéVez, Cristina

    2009-06-01

    Laguna Vilama is a hypersaline Lake located at 4660 m altitude in the northwest of Argentina high up in the Andean Puna. The impact of ultraviolet (UV) radiation on bacterioplankton was studied by collecting samples at different times of the day. Molecular analysis (DGGE) showed that the bacterioplankton community is characterized by Gamma-proteobacteria (Halomonas sp., Marinobacter sp.), Alpha-proteobacteria (Roseobacter sp.), HGC (Agrococcus jenensis and an uncultured bacterium), and CFB (uncultured Bacteroidetes). During the day, minor modifications in bacterial diversity such as intensification of Bacteroidetes' signal and an emergence of Gamma-proteobacteria (Marinobacter flavimaris) were observed after solar exposure. DNA damage, measured as an accumulation of Cyclobutane Pyrimidine Dimers (CPDs), in bacterioplankton and naked DNA increased from 100 CPDs MB-1 at 1200 local time (LT) to 300 CPDs MB-1 at 1600 LT, and from 80 CPDs MB-1 at 1200 LT to 640 CPDs MB-1 at 1600 LT, respectively. In addition, pure cultures of Pseudomonas sp. V1 and Brachybacterium sp. V5, two bacteria previously isolated from this environment, were exposed simultaneously with the community, and viability of both strains diminished after solar exposure. No CPD accumulation was observed in either of the exposed cultures, but an increase in mutagenesis was detected in V5. Of both strains only Brachybacterium sp. V5 showed CPD accumulation in naked DNA. These results suggest that the bacterioplankton community is well adapted to this highly solar irradiated environment showing little accumulation of CPDs and few changes in the community composition. They also demonstrate that these microorganisms contain efficient mechanisms against UV damage.

  4. Constraining the temporal evolution of a deep hypersaline anoxic basin by 1D geochemical modelling

    NASA Astrophysics Data System (ADS)

    Goldhammer, Tobias; Aiello, Ivano; Zabel, Matthias

    2014-05-01

    Deep hypersaline anoxic basins (DHABs) are seafloor features of the accretionary prism of the Mediterranean Ridge. They have formed by the dissolution of exhumed shallow Messinian evaporites and subsequent concentration of the ultra-saline solutions in depressions on the seafloor. As an example, the horseshoe-shaped Urania basin is a DHAB south of the Peloponnese peninsula contains one of the most saline (about six times higher than Mediterranean seawater) and sulfidic (up to 15mM) water bodies of the Earth. Furthermore, its deepest part is underlain by a mud volcano that is responsible for the injection of fluid mud beneath the brine lake, with exceptionally sharp chemoclines between water column, brine, and mud layer. We here present a model approach to reconstruct the temporal aspects of the formation, dynamics and persistence of the brine-mud-system in the deep pit of the Urania Basin. Based on data from a sampling campaign with RV Meteor (Cruise M84/1 in February 2011), we set up a one-dimensional geochemical model that integrates diffusion, reaction and advective transport and mixing. Using a set of model preconditions, we aimed to answer (1) which processes are required to maintain the current situation of steep chemical gradients of the brine-mud-system, (2) how fast the current situation could have developed under different scenarios, and (3) how long such extraordinary conditions could have persisted through Earth's history. We further discuss the consequences of the temporal framework for the evolution of prokaryotic life in this extreme habitat.

  5. Morphological responses of mitochondria-rich cells to hypersaline environment in the Australian mudskipper, Periophthalmus minutus.

    PubMed

    Itoki, Naoko; Sakamoto, Tatsuya; Hayashi, Masahiro; Takeda, Tatsusuke; Ishimatsu, Atsushi

    2012-07-01

    A population of the Australian mudskipper, Periophthalmus minutus, was found to inhabit mudflat that remained uncovered by tide for more than 20 days in some neap tides. During these prolonged emersion periods, P. minutus retreated into burrows containing little water, with a highest recorded salinity of 84 ± 7.4 psu (practical salinity unit). To explore the mechanical basis for this salinity tolerance in P. minutus, we determined the densities of mitochondria-rich cells (MRCs) in the inner and outer opercula and the pectoral fin skin, in comparison with P. takita, [corrected] from an adjacent lower intertidal habitat, and studied morphological responses of MRCs to exposure to freshwater (FW), and 100% (34-35 psu) and 200% seawater (SW). Periophthalmus minutus showed a higher density of MRCs in the inner operculum (3365 ± 821 cells mm(-2)) than in the pectoral fin skin (1428 ± 161) or the outer operculum (1100 ± 986), all of which were higher than the MRC densities in p. takita. [corrected]. No mortality occurred in 100% or 200% SW, but half of the fish died within four days in FW. Neither 200% SW nor FW exposure affected MRC density. Transfer to 200% SW doubled MRC size after 9-14 days with no change in the proportion of MRCs with apical pits or plasma sodium concentration. In contrast, transfer to FW resulted in a rapid closing of pits and a significant reduction in plasma sodium concentration. These results suggest that P. minutus has evolved morphological and physiological mechanisms to withstand hypersaline conditions that they may encounter in their habitat. PMID:22775253

  6. Stage susceptibility of Japanese medaka (Oryzias latipes) to selenomethionine and hypersaline developmental toxicity.

    PubMed

    Kupsco, Allison; Schlenk, Daniel

    2016-05-01

    Anthropogenic disturbance of seleniferous soils can lead to selenium contamination of waterways. Although selenium is an essential micronutrient, bioaccumulation and maternal transfer of proteinaceous selenomethionine (SeMet) can result in embryo toxicity. Furthermore, as the climate changes, the salinity of spawning grounds in water-restrained estuaries is increasing. Although a small increase in salinity may not directly impact adult fish, it may alter the detoxification strategies of developing organisms. Previous research indicates that hypersalinity may potentiate SeMet embryo toxicity at an early developmental stage. However, embryonic development is a complex, spatiotemporal process with a constantly shifting cellular microenvironment. To generate thresholds and an adverse outcome pathway for the interactions between selenium and salinity, we sought to identify windows of susceptibility for lethality and deformities in the Japanese medaka (Oryzias latipes). Embryos were treated in freshwater or saltwater for 24 h with 0.5 µM, 5 µM, and 50 µM SeMet at 6 different developmental stages (9, 17, 25, 29, 34, and 38). Survival, hatch, deformities (total, type, and severity), and days to hatch were quantified. Selenium embryo tissue measurements were performed. Selenomethionine exposures of 5 µM and 50 µM significantly decreased survival and hatch at all stages. However, SeMet uptake was stage-dependent and increased with stage. Stage 17 (early neurulation) was identified as the most susceptible stage for lethality and deformities. Selenomethionine in saltwater caused significantly greater toxicity than freshwater at stage 25 (early organogenesis), suggesting a role for liver and osmoregulatory organogenesis in toxicity. Environ Toxicol Chem 2016;35:1247-1256. © 2015 SETAC. PMID:26442765

  7. Effect of oxygen concentration on photosynthesis and respiration in two hypersaline microbial mats.

    PubMed

    Grötzschel, S; de Beer, D

    2002-10-01

    The effects of oxygen concentration on photosynthesis and respiration in two hypersaline cyanobacterial mats were investigated. Experiments were carried out on mats from Eilat, Israel, with moderate photosynthetic activity, and mats from Mallorca, Spain, with high photosynthetic activity. The oxygen concentration in the overlying water above the mats was increased stepwise from 0% to 100% O2. Subsequent changes in oxygen concentration, gross photosynthetic rates, and pH values inside the mats were measured with microelectrodes. According to published reports on the regulation of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), the key enzyme in the CO2-fixation pathway of phototrophs, we expected photosynthetic activity to decrease with increasing oxygen concentration. Gross photosynthetic and total respiration rates in both mats were highest when the O2 concentration was at 0% in the overlying water. Net oxygen production rates under these conditions were the same as under air saturation (21% O2), while gross photosynthetic and respiration rates were lowest at air saturation. In both mats, gross photosynthetic and respiration rates increased upon gradually increasing the oxygen concentration in the overlying water from 21% to 100%. These results contradict the expectation that photosynthesis decreases with increasing oxygen concentration. Increased photosynthetic rates at oxygen concentrations above 21% were probably caused by enhanced oxidation of organic matter and concomitant CO2 production due to the increased oxygen availability. The cause of the high respiration rates at 0% O2 in the overlying water was presumably the enhanced excretion of photosynthetic products during increased photosynthesis. We conclude that the effect of the O2/CO2 concentration ratio on the activity of Rubisco as demonstrated in vitro on enzyme extracts cannot be extrapolated to the situation in intact microbial mats, because the close coupling of the activity of primary

  8. Fermentation couples Chloroflexi and sulfate-reducing bacteria to Cyanobacteria in hypersaline microbial mats.

    PubMed

    Lee, Jackson Z; Burow, Luke C; Woebken, Dagmar; Everroad, R Craig; Kubo, Mike D; Spormann, Alfred M; Weber, Peter K; Pett-Ridge, Jennifer; Bebout, Brad M; Hoehler, Tori M

    2014-01-01

    Past studies of hydrogen cycling in hypersaline microbial mats have shown an active nighttime cycle, with production largely from Cyanobacteria and consumption from sulfate-reducing bacteria (SRB). However, the mechanisms and magnitude of hydrogen cycling have not been extensively studied. Two mats types near Guerrero Negro, Mexico-permanently submerged Microcoleus microbial mat (GN-S), and intertidal Lyngbya microbial mat (GN-I)-were used in microcosm diel manipulation experiments with 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), molybdate, ammonium addition, and physical disruption to understand the processes responsible for hydrogen cycling between mat microbes. Across microcosms, H2 production occurred under dark anoxic conditions with simultaneous production of a suite of organic acids. H2 production was not significantly affected by inhibition of nitrogen fixation, but rather appears to result from constitutive fermentation of photosynthetic storage products by oxygenic phototrophs. Comparison to accumulated glycogen and to CO2 flux indicated that, in the GN-I mat, fermentation released almost all of the carbon fixed via photosynthesis during the preceding day, primarily as organic acids. Across mats, although oxygenic and anoxygenic phototrophs were detected, cyanobacterial [NiFe]-hydrogenase transcripts predominated. Molybdate inhibition experiments indicated that SRBs from a wide distribution of DsrA phylotypes were responsible for H2 consumption. Incubation with (13)C-acetate and NanoSIMS (secondary ion mass-spectrometry) indicated higher uptake in both Chloroflexi and SRBs relative to other filamentous bacteria. These manipulations and diel incubations confirm that Cyanobacteria were the main fermenters in Guerrero Negro mats and that the net flux of nighttime fermentation byproducts (not only hydrogen) was largely regulated by the interplay between Cyanobacteria, SRBs, and Chloroflexi. PMID:24616716

  9. Unexpected Diversity and Complexity of the Guerrero Negro Hypersaline Microbial Mat

    PubMed Central

    Ley, Ruth E.; Harris, J. Kirk; Wilcox, Joshua; Spear, John R.; Miller, Scott R.; Bebout, Brad M.; Maresca, Julia A.; Bryant, Donald A.; Sogin, Mitchell L.; Pace, Norman R.

    2006-01-01

    We applied nucleic acid-based molecular methods, combined with estimates of biomass (ATP), pigments, and microelectrode measurements of chemical gradients, to map microbial diversity vertically on a millimeter scale in a hypersaline microbial mat from Guerrero Negro, Baja California Sur, Mexico. To identify the constituents of the mat, small-subunit rRNA genes were amplified by PCR from community genomic DNA extracted from layers, cloned, and sequenced. Bacteria dominated the mat and displayed unexpected and unprecedented diversity. The majority (1,336) of the 1,586 bacterial 16S rRNA sequences generated were unique, representing 752 species (≥97% rRNA sequence identity) in 42 of the main bacterial phyla, including 15 novel candidate phyla. The diversity of the mat samples differentiated according to the chemical milieu defined by concentrations of O2 and H2S. Bacteria of the phylum Chloroflexi formed the majority of the biomass by percentage of bulk rRNA and of clones in rRNA gene libraries. This result contradicts the general belief that cyanobacteria dominate these communities. Although cyanobacteria constituted a large fraction of the biomass in the upper few millimeters (>80% of the total rRNA and photosynthetic pigments), Chloroflexi sequences were conspicuous throughout the mat. Filamentous Chloroflexi bacteria were identified by fluorescence in situ hybridization within the polysaccharide sheaths of the prominent cyanobacterium Microcoleus chthonoplastes, in addition to free living in the mat. The biological complexity of the mat far exceeds that observed in other polysaccharide-rich microbial ecosystems, such as the human and mouse distal guts, and suggests that positive feedbacks exist between chemical complexity and biological diversity. PMID:16672518

  10. Glycomyces fuscus sp. nov. and Glycomyces albus sp. nov., actinomycetes isolated from a hypersaline habitat.

    PubMed

    Han, Xiao-Xue; Luo, Xiao-Xia; Zhang, Li-Li

    2014-07-01

    Two actinomycete strains, designated TRM 49117(T) and TRM 49136(T), were isolated from a hypersaline habitat in Xinjiang Province, north-west China and were characterized taxonomically by using a polyphasic study. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain TRM 49117(T) had 93.93% similarity with the type strain Glycomyces halotolerans TRM 40137(T) (GenBank accession no. HQ651156) and TRM 49136(T) had 94.32% similarity with G. halotolerans TRM 40137(T). The 16S rRNA gene sequence similarity between the two new isolates was 93%. The isolates contained meso-diaminopimelic acid as the diagnostic diamino acid and anteiso-C15 : 0, iso-C16 : 0 and anteiso-C17 : 0 as major cellular fatty acids. The predominant menaquinones of the isolates were MK-9(H4) and MK-9(H6). The whole-cell sugar patterns of these strains contained xylose and ribose, and strain TRM 49136(T) also contained arabinose. The polar lipid pattern of strain TRM 49117(T) comprised phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol mannosides, phosphatidylcholine, phosphatidylinositol and three additional unknown phospholipids. The polar lipid pattern of strain TRM 49136(T) comprised phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylinositol, glycolipids and two phosphoglycolipids of unknown composition. Genotypic and phenotypic data confirmed that strains TRM 49117(T) and TRM 49136(T) represent two novel species, clearly different from related species of the genus Glycomyces, for which the names Glycomyces fuscus sp. nov. (type strain TRM 49117(T) = CCTCC AA 2013003(T) = NRRL B-59998(T) = KACC 17682(T)) and Glycomyces albus sp. nov. (type strain TRM 49136(T) = CCTCC AA 2013004(T) = NRRL B-24927(T) = KACC 17681(T)) are proposed. PMID:24776532

  11. Mathematical simulation of the diel O, S, and C biogeochemistry of a hypersaline microbial mat.

    PubMed

    Decker, K L M; Potter, C S; Bebout, B M; Marais, D J Des; Carpenter, S; Discipulo, M; Hoehler, T M; Miller, S R; Thamdrup, B; Turk, K A; Visscher, P T

    2005-05-01

    The creation of a mathematical simulation model of photosynthetic microbial mats is important to our understanding of key biogeochemical cycles that may have altered the atmospheres and lithospheres of early Earth. A model is presented here as a tool to integrate empirical results from research on hypersaline mats from Baja California Sur (BCS), Mexico into a computational system that can be used to simulate biospheric inputs of trace gases to the atmosphere. The first version of our model, presented here, calculates fluxes and cycling of O(2), sulfide, and dissolved inorganic carbon (DIC) via abiotic components and via four major microbial guilds: cyanobacteria (CYA), sulfate reducing bacteria (SRB), purple sulfur bacteria (PSB) and colorless sulfur bacteria (CSB). We used generalized Monod-type equations that incorporate substrate and energy limits upon maximum rates of metabolic processes such as photosynthesis and sulfate reduction. We ran a simulation using temperature and irradiance inputs from data collected from a microbial mat in Guerrero Negro in BCS (Mexico). Model O(2), sulfide, and DIC concentration profiles and fluxes compared well with data collected in the field mats. There were some model-predicted features of biogeochemical cycling not observed in our actual measurements. For instance, large influxes and effluxes of DIC across the MBGC mat boundary may reveal previously unrecognized, but real, in situ limits on rates of biogeochemical processes. Some of the short-term variation in field-collected mat O(2) was not predicted by MBGC. This suggests a need both for more model sensitivity to small environmental fluctuations for the incorporation of a photorespiration function into the model. PMID:16329922

  12. Halorubrum halodurans sp. nov., an extremely halophilic archaeon isolated from a hypersaline lake.

    PubMed

    Corral, Paulina; de la Haba, Rafael R; Sánchez-Porro, Cristina; Ali Amoozegar, Mohammad; Thane Papke, R; Ventosa, Antonio

    2016-01-01

    Two extremely halophilic archaea, strains Cb34T and C170, belonging to the genus Halorubrum, were isolated from the brine of the hypersaline lake Aran-Bidgol in Iran. Cells of the two strains were motile, pleomorphic rods, stained Gram-variable and produced red-pigmented colonies. Strains Cb34T and C170 required 25 % (w/v) salts, pH 7.0 and 37 °C for optimal growth under aerobic conditions; 0.3 M Mg2+ was required. Cells of both isolates were lysed in distilled water and hypotonic treatment with < 10 % NaCl provoked cell lysis. Phylogenetic analysis based on 16S rRNA gene sequence similarities showed that these two strains were closely related to Halorubrum cibi B31T (98.8 %) and other members of the genus Halorubrum. In addition, studies based on the rpoB' gene revealed that strains Cb34T and C170 are placed among the species of Halorubrum and are closely related to Halorubrum cibi B31T, with rpoB' gene sequence similarity less than or equal to 95.7 %. The polar lipid patterns of both strains consisted of phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and sulfated mannosyl glucosyl diether. The DNA G+C content was 62.1-62.4 mol%. DNA-DNA hybridization studies confirmed that strains Cb34T and C170 constitute a distinct species. Data obtained in this study show that the two strains represent a novel species, for which the name Halorubrum halodurans sp. nov. is proposed. The type strain is Cb34T ( = CECT 8745T = IBRC-M 10233T). PMID:26537912

  13. Fermentation couples Chloroflexi and sulfate-reducing bacteria to Cyanobacteria in hypersaline microbial mats

    PubMed Central

    Lee, Jackson Z.; Burow, Luke C.; Woebken, Dagmar; Everroad, R. Craig; Kubo, Mike D.; Spormann, Alfred M.; Weber, Peter K.; Pett-Ridge, Jennifer; Bebout, Brad M.; Hoehler, Tori M.

    2013-01-01

    Past studies of hydrogen cycling in hypersaline microbial mats have shown an active nighttime cycle, with production largely from Cyanobacteria and consumption from sulfate-reducing bacteria (SRB). However, the mechanisms and magnitude of hydrogen cycling have not been extensively studied. Two mats types near Guerrero Negro, Mexico—permanently submerged Microcoleus microbial mat (GN-S), and intertidal Lyngbya microbial mat (GN-I)—were used in microcosm diel manipulation experiments with 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), molybdate, ammonium addition, and physical disruption to understand the processes responsible for hydrogen cycling between mat microbes. Across microcosms, H2 production occurred under dark anoxic conditions with simultaneous production of a suite of organic acids. H2 production was not significantly affected by inhibition of nitrogen fixation, but rather appears to result from constitutive fermentation of photosynthetic storage products by oxygenic phototrophs. Comparison to accumulated glycogen and to CO2 flux indicated that, in the GN-I mat, fermentation released almost all of the carbon fixed via photosynthesis during the preceding day, primarily as organic acids. Across mats, although oxygenic and anoxygenic phototrophs were detected, cyanobacterial [NiFe]-hydrogenase transcripts predominated. Molybdate inhibition experiments indicated that SRBs from a wide distribution of DsrA phylotypes were responsible for H2 consumption. Incubation with 13C-acetate and NanoSIMS (secondary ion mass-spectrometry) indicated higher uptake in both Chloroflexi and SRBs relative to other filamentous bacteria. These manipulations and diel incubations confirm that Cyanobacteria were the main fermenters in Guerrero Negro mats and that the net flux of nighttime fermentation byproducts (not only hydrogen) was largely regulated by the interplay between Cyanobacteria, SRBs, and Chloroflexi. PMID:24616716

  14. Nucleotide sequences encoding a thermostable alkaline protease

    DOEpatents

    Wilson, David B.; Lao, Guifang

    1998-01-01

    Nucleotide sequences, derived from a thermophilic actinomycete microorganism, which encode a thermostable alkaline protease are disclosed. Also disclosed are variants of the nucleotide sequences which encode a polypeptide having thermostable alkaline proteolytic activity. Recombinant thermostable alkaline protease or recombinant polypeptide may be obtained by culturing in a medium a host cell genetically engineered to contain and express a nucleotide sequence according to the present invention, and recovering the recombinant thermostable alkaline protease or recombinant polypeptide from the culture medium.

  15. Nucleotide sequences encoding a thermostable alkaline protease

    DOEpatents

    Wilson, D.B.; Lao, G.

    1998-01-06

    Nucleotide sequences, derived from a thermophilic actinomycete microorganism, which encode a thermostable alkaline protease are disclosed. Also disclosed are variants of the nucleotide sequences which encode a polypeptide having thermostable alkaline proteolytic activity. Recombinant thermostable alkaline protease or recombinant polypeptide may be obtained by culturing in a medium a host cell genetically engineered to contain and express a nucleotide sequence according to the present invention, and recovering the recombinant thermostable alkaline protease or recombinant polypeptide from the culture medium. 3 figs.

  16. Methane as a biomarker in the search for extraterrestrial life: Lessons learned from Mars analog hypersaline environments

    NASA Astrophysics Data System (ADS)

    Bebout, B.; Tazaz, A.; Kelley, C. A.; Poole, J. A.; Davila, A.; Chanton, J.

    2010-12-01

    Methane released from discrete regions on Mars, together with previous reports of methane determined with ground-based telescopes, has revived the possibility of past or even extant life near the surface on Mars, since 90% of the methane on Earth has a biological origin. This intriguing possibility is supported by the abundant evidence of large bodies of liquid water, and therefore of conditions conducive to the origin of life, early in the planet's history. The detection and analysis of methane is at the core of NASA’s strategies to search for life in the solar system, and on extrasolar planets. Because methane is also produced abiotically, it is important to generate criteria to unambiguously assess biogenicity. The stable carbon and hydrogen isotopic signature of methane, as well as its ratio to other low molecular weight hydrocarbons (the methane/(ethane + propane) ratio: C1/(C2 + C3)), has been suggested to be diagnostic for biogenic methane. We report measurements of the concentrations and stable isotopic signature of methane from hypersaline environments. We focus on hypersaline environments because spectrometers orbiting Mars have detected widespread chloride bearing deposits resembling salt flats. Other evaporitic minerals, e.g., sulfates, are also abundant in several regions, including those studied by the Mars Exploration Rovers. The presence of evaporitic minerals, together with the known evolution of the Martian climate, from warmer and wetter to cold and hyper-arid, suggest that evaporitic and hypersaline environments were common in the past. Hypersaline environments examined to date include salt ponds located in Baja California, the San Francisco Bay, and the Atacama Desert. Methane was found in gas produced both in the sediments, and in gypsum- and halite-hosted (endolithic) microbial communities. Maximum methane concentrations were as high as 40% by volume. The methane carbon isotopic (δ13C) composition showed a wide range of values, from about

  17. New mono-organotin (IV) dithiocarbamate complexes

    SciTech Connect

    Muthalib, Amirah Faizah Abdul; Baba, Ibrahim

    2014-09-03

    Eighteen new mono-organotin dithiocarbamate compounds derived each nine from methyltin(IV) and phenyltin(IV) reacted using in-situ method with various type of N-dialkylamine together with carbon disulphide with the ratio of 1:3:3. Elemental and gravimetric analysis showed that the general formula of these compounds were RSnCl[S{sub 2}CNR′R″]{sub 2} (R= Ph, CH{sub 3}, R′ = CH{sub 3}, C{sub 2}H{sub 5}, C{sub 7}H{sub 7} and R″ = C{sub 2}H{sub 5}, C{sub 6}H{sub 11}, iC{sub 3}H{sub 7}, C{sub 7}H{sub 7}). These compounds had been characterized by infrared spectroscopy, ultraviolet spectroscopy, {sup 1}H, {sup 13}C NMR spectroscopy and single crystal X-ray crystallography. The infrared spectra of these compounds showed three important peaks indicating the formation of dithiocarbamate compounds, ν(CN), ν(CS) and ν(Sn-S) band which present in the region of 1444–1519, 954–1098 and 318–349 cm{sup −1} respectively. The ultraviolet-visible spectra showed an absorption band for the π - π* transition of NCS group in the range of 253 – 259 nm due to the intramolecular charge transfer of the ligand. The {sup 13}C NMR spectra showed an important shift for δ(N{sup 13}CS{sub 2}) in the range of 196.8 – 201.9 ppm.. Single crystal X-ray diffraction studies showed three new structures with the general formula of PhSnCl[S{sub 2}CN(Et)(i−Pr)]{sub 2}, MeSnCl[S{sub 2}CN(Me)(Cy)]{sub 2} and MeSnCl[S{sub 2}CN(i−Pr)(CH{sub 2}Ph)]{sub 2}. All structures having a distorted octahedral geometry set by CClS{sub 4} donor atom from the two chelating dithiocarbamate ligands.

  18. Mono- and Polyhydrated Sulfates in Tithonium Chasma

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This image of sulfate-containing deposits in Tithonium Chasma was taken by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) at 1538 UTC (11:38 a.m. EDT) on August 31, 2007 near 5.22 degrees south latitude, 270.48 degrees east longitude. CRISM's image was taken in 544 colors covering 0.36-3.92 micrometers, and shows features as small as 40 meters (132 feet) across. The region covered is just over 10 kilometers (6.2 miles) wide at its narrowest point.

    Tithonium Chasma lies at the western end of the Valles Marineris canyon system. It extends approximately east-west for roughly 810 kilometers (503 miles), varies in width from approximately 10 to 110 kilometers (6 to 68 miles), and cuts into the Martian surface to a maximum depth of roughly 6 kilometers (4 miles).

    The top panel in the montage above shows the location of the CRISM image on a mosaic taken by the Mars Odyssey spacecraft's Thermal Emission Imaging System (THEMIS). The CRISM data covers an area centered on a ridge of erosion-resistant rock.

    The center left image, an infrared false color image, reveals banded, light-colored material draped on the ridge. The center right image unveils the mineralogical composition of the area, with yellow representing monohydrated sulfates (sulfates with one water molecule incorporated into each molecule of the mineral) and purple polyhydrated sulfates (sulfates with multiple waters per mineral molecule).

    The lower two images are renderings of data draped over topography with 7 times vertical exaggeration. These images provide a view of the topography and reveal how the sulfate deposits both cover and flank the ridge. Brighter, monohydrated sulfate (yellow) deposits revealed in the lower right image lies along the ridge's northwest side and fall off into a small valley or depression, while darker polyhydrated sulfates (purple) lie along the ridge's northeast flank. A deposit of both mono- and polyhydrated sulfates spanning the ridge

  19. Development of alkaline fuel cells.

    SciTech Connect

    Hibbs, Michael R.; Jenkins, Janelle E.; Alam, Todd Michael; Janarthanan, Rajeswari; Horan, James L.; Caire, Benjamin R.; Ziegler, Zachary C.; Herring, Andrew M.; Yang, Yuan; Zuo, Xiaobing; Robson, Michael H.; Artyushkova, Kateryna; Patterson, Wendy; Atanassov, Plamen Borissov

    2013-09-01

    This project focuses on the development and demonstration of anion exchange membrane (AEM) fuel cells for portable power applications. Novel polymeric anion exchange membranes and ionomers with high chemical stabilities were prepared characterized by researchers at Sandia National Laboratories. Durable, non-precious metal catalysts were prepared by Dr. Plamen Atanassov's research group at the University of New Mexico by utilizing an aerosol-based process to prepare templated nano-structures. Dr. Andy Herring's group at the Colorado School of Mines combined all of these materials to fabricate and test membrane electrode assemblies for single cell testing in a methanol-fueled alkaline system. The highest power density achieved in this study was 54 mW/cm2 which was 90% of the project target and the highest reported power density for a direct methanol alkaline fuel cell.

  20. Pairing preferences of the model mono-valence mono-atomic ions investigated by molecular simulation

    SciTech Connect

    Zhang, Qiang; Zhang, Ruiting; Zhao, Ying; Li, HuanHuan; Zhuang, Wei E-mail: gaoyq@pku.edu.cn; Gao, Yi Qin E-mail: gaoyq@pku.edu.cn

    2014-05-14

    We carried out a series of potential of mean force calculations to study the pairing preferences of a series of model mono-atomic 1:1 ions with evenly varied sizes. The probabilities of forming the contact ion pair (CIP) and the single water separate ion pair (SIP) were presented in the two-dimensional plots with respect to the ion sizes. The pairing preferences reflected in these plots largely agree with the empirical rule of matching ion sizes in the small and big size regions. In the region that the ion sizes are close to the size of the water molecule; however, a significant deviation from this conventional rule is observed. Our further analysis indicated that this deviation originates from the competition between CIP and the water bridging SIP state. The competition is mainly an enthalpy modulated phenomenon in which the existing of the water bridging plays a significant role.

  1. Salt resistance genes revealed by functional metagenomics from brines and moderate-salinity rhizosphere within a hypersaline environment.

    PubMed

    Mirete, Salvador; Mora-Ruiz, Merit R; Lamprecht-Grandío, María; de Figueras, Carolina G; Rosselló-Móra, Ramon; González-Pastor, José E

    2015-01-01

    Hypersaline environments are considered one of the most extreme habitats on earth and microorganisms have developed diverse molecular mechanisms of adaptation to withstand these conditions. The present study was aimed at identifying novel genes from the microbial communities of a moderate-salinity rhizosphere and brine from the Es Trenc saltern (Mallorca, Spain), which could confer increased salt resistance to Escherichia coli. The microbial diversity assessed by pyrosequencing of 16S rRNA gene libraries revealed the presence of communities that are typical in such environments and the remarkable presence of three bacterial groups never revealed as major components of salt brines. Metagenomic libraries from brine and rhizosphere samples, were transferred to the osmosensitive strain E. coli MKH13, and screened for salt resistance. Eleven genes that conferred salt resistance were identified, some encoding for well-known proteins previously related to osmoadaptation such as a glycerol transporter and a proton pump, whereas others encoded proteins not previously related to this function in microorganisms such as DNA/RNA helicases, an endonuclease III (Nth) and hypothetical proteins of unknown function. Furthermore, four of the retrieved genes were cloned and expressed in Bacillus subtilis and they also conferred salt resistance to this bacterium, broadening the spectrum of bacterial species in which these genes can function. This is the first report of salt resistance genes recovered from metagenomes of a hypersaline environment. PMID:26528268

  2. Culture-dependent and culture-independent analysis of hydrocarbonoclastic microorganisms indigenous to hypersaline environments in Kuwait.

    PubMed

    Al-Mailem, Dina; Eliyas, Mohamed; Khanafer, Majeda; Radwan, Samir

    2014-05-01

    The halophilic, hydrocarbonoclastic bacteria and archaea inhabiting two hypersaline coastal areas in Kuwait, one in the north and the other in the south, were counted and characterized. Environmental parameters in both areas were similar, with the exception of the soil organic carbon content, which was in the north higher than in the south. The hydrocarbonoclastic bacterial and haloarchaeal numbers and identities as analyzed using nutrient media of various salinities were similar in soil and pond water samples from both areas. The bacterial species recorded by this culture-dependent method belonged to the genera Halomonas, Chromohalobacter, Marinobacter, Exiguobacterium, Stenotrophomonas, Pseudomonas, Salinivibrio, and Bacillus. The haloarchaeal species belonged to the genera Haloferax and Halobacterium. When analyzed by fingerprinting of their amplified genomic DNA followed by sequencing of the electrophoresis-resolved bands, the same environmental samples revealed a different microbial composition. Bacterial phylotypes recorded by this culture-independent method were affiliated with the genera Ochrobactrum, Stenotrophomonas, Rhodococcus, and "Halomicrobium," whereas the archaeal phylotypes were affiliated with Halorussus, Halomicrobium, and Halorientalis. The observed diversity and composition similarity of the hydrocarbonocalastic microflora in both hypersaline areas suggest an effective potential for oil mineralization therein. This potential has been confirmed experimentally. PMID:24682340

  3. Osmoregulation by juvenile brown-banded bamboo sharks, Chiloscyllium punctatum, in hypo- and hyper-saline waters.

    PubMed

    Cramp, R L; Hansen, M J; Franklin, C E

    2015-07-01

    While there is a considerable body of work describing osmoregulation by elasmobranchs in brackish and saltwater, far fewer studies have investigated osmoregulation in hypersaline waters. We examined osmo- and ionoregulatory function and plasticity in juvenile brown-banded bamboo sharks, Chiloscyllium punctatum, exposed to three experimental salinities (25, 34 and 40‰) for two weeks. C. punctatum inhabits sheltered coastal areas and bays which can naturally become hypersaline as a consequence of evaporation of water but can also become hyposaline during flood events. We hypothesised that C. punctatum would demonstrate a phenotypically plastic osmoregulatory physiology. Plasma osmolality, urea, Na(+) and Cl(-) levels increased significantly with increasing environmental salinity. Rectal gland and branchial sodium-potassium ATPase (NKA) activities were unaffected by salinity. Using immunohistochemistry and Western Blotting we found evidence for the presence of the key ion-regulatory proteins vacuolar H(+)-ATPase (VHA), pendrin (Cl(-)/HCO₃(-) co-transporter) and the Na(+)-H(+) exchanger isoform 3 (NHE3) in discrete cells within the branchial epithelia. These results indicate that C. punctatum is a partially euryhaline elasmobranch able to maintain osmo- and ionoregulatory function between environmental salinities of 25‰ and 40‰. As suggested for other elasmobranchs, the gills of C. punctatum likely play a limited role in maintaining Na(+) homeostasis over the salinity range studied, but may play an important role in acid-base balance. PMID:25868436

  4. Salt resistance genes revealed by functional metagenomics from brines and moderate-salinity rhizosphere within a hypersaline environment

    PubMed Central

    Mirete, Salvador; Mora-Ruiz, Merit R.; Lamprecht-Grandío, María; de Figueras, Carolina G.; Rosselló-Móra, Ramon; González-Pastor, José E.

    2015-01-01

    Hypersaline environments are considered one of the most extreme habitats on earth and microorganisms have developed diverse molecular mechanisms of adaptation to withstand these conditions. The present study was aimed at identifying novel genes from the microbial communities of a moderate-salinity rhizosphere and brine from the Es Trenc saltern (Mallorca, Spain), which could confer increased salt resistance to Escherichia coli. The microbial diversity assessed by pyrosequencing of 16S rRNA gene libraries revealed the presence of communities that are typical in such environments and the remarkable presence of three bacterial groups never revealed as major components of salt brines. Metagenomic libraries from brine and rhizosphere samples, were transferred to the osmosensitive strain E. coli MKH13, and screened for salt resistance. Eleven genes that conferred salt resistance were identified, some encoding for well-known proteins previously related to osmoadaptation such as a glycerol transporter and a proton pump, whereas others encoded proteins not previously related to this function in microorganisms such as DNA/RNA helicases, an endonuclease III (Nth) and hypothetical proteins of unknown function. Furthermore, four of the retrieved genes were cloned and expressed in Bacillus subtilis and they also conferred salt resistance to this bacterium, broadening the spectrum of bacterial species in which these genes can function. This is the first report of salt resistance genes recovered from metagenomes of a hypersaline environment. PMID:26528268

  5. Isotopic composition of a large photosymbiotic foraminifer: Evidence for hypersaline environments across the Great Australian Bight during the late Pleistocene

    NASA Astrophysics Data System (ADS)

    Rivers, John M.; Kyser, T. Kurt; James, Noel P.

    2009-01-01

    Analysis of carbon and oxygen isotopic compositions of large benthic foraminifera tests ( Marginopora vertebralis) that lived in the Great Australian Bight during the late Pleistocene, reveal that the tests are enriched by 1 to 3‰ in both 18O and 13C relative to modern specimens from the same region. The intolerance of M. vertebralis for cool waters negates lower ocean water temperature as an explanation for such high δ 18O values. The oxygen isotopic compositions are thus interpreted to reflect tests secreted in hypersaline waters of up to 56 ppt salinity, concentrated from seawater by evaporation. M. vertebralis thrives today in waters of similar salinity at Shark Bay, Western Australia. The Pleistocene sedimentary assemblage supports an interpretation that environments broadly similar to those in outer modern-day Shark Bay were wide spread across the Great Australian Bight during portions of marine isotope stages 2, 3 and 4. The high δ 13C values of the Pleistocene M. vertebralis are interpreted to reflect enhanced photosynthetic activity that depletes dissolved carbonate in 12C in such shallow, saline settings. These hypersaline environments formed during periods of lower sea-level when shallow-waters (< 20 m depth) extended from the shoreline over ~ 100 km across what is currently a relatively deep shelf. This study indicates that shelf bathymetry was a critical determinant of past environments of deposition across the Great Australian Bight.

  6. Evaluation of saturation vapor pressure over hypersaline water bodies at the southern edge of the Dead Sea, Jordan

    SciTech Connect

    Oroud, I.M. )

    1994-12-01

    The activity coefficient and saturation vapor pressure for hypersaline solutions located at the southern edge of the Dead Sea are computed analytically. The collected data consist of temperature and evaporation rates measured for a freshwater pan and three other hypersaline solutions with specific gravities of 1.26, 1.31, and 1.34, respectively. The activity coefficients of the three saline pans were computed after accounting for the effect of buoyancy, which was included in the computations because of consistently large, positive virtual temperature differences between the saline pans and the ambient air. The ratios of saline to fresh pan evaporation (Es/Ef: the [alpha] ratio) of the present study are also compared to data reported for the Bonneville Salt Brines, Utah. It is found that the a ratios of the present study, although conducted over an extended period of time, are larger than those reported for the Bonneville Brines. Results of the present study imply that evaporation from the various brine-concentrated, shallow lakes at the southern edge of the Dead Sea is likely to proceed during the entire year, and water vapor deposition from the atmosphere, due to an inverted vapor pressure, is less likely to occur particularly for brines with specific gravities of less than 1.3.

  7. Sodium toxicity and pathology associated with exposure of waterfowl to hypersaline playa lakes of southeast New Mexico

    USGS Publications Warehouse

    Meteyer, C.U.; Dubielzig, R.D.; Dein, F.J.; Baeten, L.A.; Moore, M.K.; Jehl, J.R., Jr.; Wesenberg, K.E.

    1997-01-01

    Cause of mortality was studied in waterfowl in hypersaline playa lakes of southeast New Mexico during spring and fall migration. Mortality was not common in wild ducks resting on the playas during good weather. However, when birds remained on the lakes for prolonged periods of time, such as during experimental trials and stormy weather, a heavy layer of salt precipitated on their feathers. Sodium toxicity was the cause of death for all experimental mallards housed on playa water and for 50% of the wild waterfowl found moribund or dead during the spring of 1995. Gross lesions included heavy salt precipitation on the feathers, ocular lens opacities, deeply congested brains, and dilated, thin-walled, fluid-filled cloacae. Microscopic lesions in the more severely affected birds included liquefaction of ocular lens cortex with lens fiber swelling and multifocal to diffuse ulcerative conjunctivitis with severe granulocytic inflammation, edema, and granulocytic vasculitis resulting in thrombosis. Inflammation similar to that seen in the conjunctiva occasionally involved the mucosa of the mouth, pharynx, nasal turbinates, cloaca, and bursa. Transcorneal movement of water in response to the hypersaline conditions on the playa lakes or direct contact with salt crystals could induce anterior segment dehydration of the aqueous humor and increased osmotic pressure on the lens, leading to cataract formation.

  8. Dormant stages of crustaceans as a mechanism of propagation in the extreme and unpredictable environment in the Crimean hypersaline lakes

    NASA Astrophysics Data System (ADS)

    Shadrin, Nickolai V.; Anufriieva, Elena V.; Amat, Francisco; Eremin, Oleg Yu.

    2015-11-01

    A pool of dormant stages of planktonic organisms in saline lakes is a substantial component in the plankton communities; we need to take it into account to understand plankton dynamics. Hypersaline water bodies in Crimea, the largest peninsula in the Black Sea, constitute a very characteristic and peculiar habitat type in the region. We examined the presence of crustacean resting stages in sediments of dried up sites of the Crimean hypersaline lakes. Sediment samples were taken in 9 different lakes. Experiments performed on the hatching of these resting stages showed the presence of Moina salina (Cladocera), parthenogenetic Artemia and Artemia urmiana (Anostraca), Eucypris mareotica ( inflata) (Ostracoda), and Cletocamptus retrogressus (Harpacticoida). Comparing the experimental results obtained with clean dried brine shrimp cysts and those kept in sediment samples, it was noted that clean cysts hatched much faster than those from sediments did. Some components in bottom sediments slow down and desynchronize hatching from resting eggs in different groups of crustaceans. The sediments of different lakes inhibited the nauplii output from Artemia and ostracod resting eggs to different degrees. More data are needed before we can discuss the reasons of this inhibition. The nonsynchronous output of active stages from the bottom resting ones may be an adaptation that allows crustacean species to exist in extreme and unpredictably changing environments, avoiding the risk that all may emerge at once under unsuitable conditions.

  9. Spatially-resolved stable isotope analysis of a hypersaline microbial mat

    NASA Astrophysics Data System (ADS)

    Moran, J.; Cory, A. B.; Lindemann, S. R.; Fredrickson, J. K.

    2012-12-01

    Hot Lake is a hypersaline, meromictic lake located in north-central Washington. High rates of evapotranspiration coupled with its location in an endorrheic basin contribute to the lake's high salinity. The predominant dissolved salt is magnesium sulfate; hypolimnion waters may seasonally exceed 2 M magnesium sulfate concentrations. In addition to extreme salinity, horizons within the lake seasonally exceed 50 °C, in part due to the enhanced light absorption by magnesium sulfate-saturated water. Despite extreme and highly variable seasonal conditions (salinity, temperature, photon flux), dense benthic microbial mats composed of cyanobacteria and bacterial heterotroph populations develop annually at the lake. These mats may exceed 5 mm in thickness and display stratification observable by eye associated with dominant bacterial phototrophic pigments. Typical mat stratification includes an orange surface layer followed by green and purple layers at increasing depth into the mat. Carbonates including aragonite and magnesite are observed within the mat and their formation is likely induced or influenced by microbial activities. While not exclusively limited to the green stratum in the mat, maximum carbonate content is within this layer. We are exploring the role Hot Lake's microbial mats play in carbon cycling within the system. Namely, we seek to understand the rates of carbon accumulation in the mat and associated sediments and the various forms this carbon takes (organic or inorganic species). We are assessing mat development, community composition, and carbon accumulation in pre-cleaned devices installed at the lake as they are colonized by native mat. We are using laser ablation isotope ratio mass spectrometry (LA-IRMS) to provide spatially-resolved stable isotope analysis of mat cross-sections. Currently, this technique permits isotope analysis at the 50 μm scale, and can provide multiple isotope analyses within the thickness of each major layer of the mat. We

  10. Distribution of picophytoplankton communities from brackish to hypersaline waters in a South Australian coastal lagoon

    PubMed Central

    2010-01-01

    Background Picophytoplankton (i.e. cyanobacteria and pico-eukaryotes) are abundant and ecologically critical components of the autotrophic communities in the pelagic realm. These micro-organisms colonized a variety of extreme environments including high salinity waters. However, the distribution of these organisms along strong salinity gradient has barely been investigated. The abundance and community structure of cyanobacteria and pico-eukaryotes were investigated along a natural continuous salinity gradient (1.8% to 15.5%) using flow cytometry. Results Highest picophytoplankton abundances were recorded under salinity conditions ranging between 8.0% and 11.0% (1.3 × 106 to 1.4 × 106 cells ml-1). Two populations of picocyanobacteria (likely Synechococcus and Prochlorococcus) and 5 distinct populations of pico-eukaryotes were identified along the salinity gradient. The picophytoplankton cytometric-richness decreased with salinity and the most cytometrically diversified community (4 to 7 populations) was observed in the brackish-marine part of the lagoon (i.e. salinity below 3.5%). One population of pico-eukaryote dominated the community throughout the salinity gradient and was responsible for the bloom observed between 8.0% and 11.0%. Finally only this halotolerant population and Prochlorococcus-like picocyanobacteria were identified in hypersaline waters (i.e. above 14.0%). Salinity was identified as the main factor structuring the distribution of picophytoplankton along the lagoon. However, nutritive conditions, viral lysis and microzooplankton grazing are also suggested as potentially important players in controlling the abundance and diversity of picophytoplankton along the lagoon. Conclusions The complex patterns described here represent the first observation of picophytoplankton dynamics along a continuous gradient where salinity increases from 1.8% to 15.5%. This result provides new insight into the distribution of pico-autotrophic organisms along strong

  11. Hypersaline Subsurface Microbial Communities from the Dead Sea Viewed from Their Metagenomes.

    NASA Astrophysics Data System (ADS)

    Thomas, C.; Ionescu, D.; Ariztegui, D.

    2014-12-01

    The Dead Sea Deep Drilling Project (DSDDP) is an international research initiative aiming to reconstruct the paleoenvironmental and paleoseismic history of the Dead Sea Basin (DSB) in the Levantine region. Within this framework, analysis of microbial communities intend to qualify the extent of life in this extreme environment, the factors allowing its development and their contribution to the sedimentary and geochemical record. The extreme chemistry of the Dead Sea prevents the use of common in situ imaging techniques leaving little information on the general activity of the subsurface biosphere. Cloning and metagenomic techniques have however been implemented at different levels of a 457 m deep core. Results suggest a differential development or survival of the microbial community along the sedimentary column. Reasons for such distribution remain unclear but cannot only be imparted to salinity. Poorly known communities (e.g. Candidate Divisions MSBL1 and KB1) with strong potential for adaptations to anoxic hypersaline environments are recovered in some intervals. Halobacteria classes generally dominate the assemblages. Metagenomic data allowed characterizing their presence in two evaporitic facies of the core (aragonite at 2.7 m and gypsum at 90.6 m below lake floor), where they exhibit both salt-in and salt-out strategies to cope with the high salinities of the Dead Sea. Metabolisms are also adapted to the high heavy metal concentrations and low nutrient availability in the sediment. Although more work is needed in order to infer the impact of these microorganisms on the sediment and element cycles, indices of methanogenesis, fermentation and sulfate reducing activity imply influence on the carbon and sulfur cycle of the Dead Sea subsurface. This is highlighted by traces of microbial degradation of organic matter viewed under SEM, and by the formation of euhedral Fe-S mineralizations as a result of reduction of sulfur. Overall, this work calls for the importance

  12. Lanthanide behavior in hypersaline evaporation ponds at Guerrero Negro, Baja California, Mexico - an environment with halophiles

    NASA Astrophysics Data System (ADS)

    Choumiline, K.; López-Cortés, A.; Grajeda-Muñoz, M.; Shumilin, E.; Sapozhnikov, D.

    2013-12-01

    Lanthanides are known, in some cases, to be sensitive to changes in water column or sediment chemistry, a fact that allows them to be used as environmental fingerprints. Nevertheless, the behavior of these elements in hypersaline environments is insufficiently understood, especially in those colonized by bacteria, archaea and eukarya halophiles. Extreme environments like the mentioned exist in the artificially-controlled ponds of the 'Exportadora de Sal' salt-producing enterprise located in Guerrero Negro (Baja California, Mexico). Sediment cores from various ponds were collected, subsampled and measured by ICP-MS and INAA. This allowed differencing the behavior of lanthanides and trace elements under a water column salinity gradient along the evaporation sequence of ponds. Sediment profiles (30 mm long), obtained in Pond 5, dominated by Ca and Mg precipitation and at the same time rich in organic matter due to bacterial mat presence, showed highs and lows of the shale-normalized patterns along different in-core depths. Two groups of elements could be distinguished with similar trends: set A (La, Ce, Pr and Nd) and set B (Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu). The first 'group A' had two prominent peaks at 15 mm and around 22 mm, whereas the 'group B' showed only slight increase at 15 mm and none at 22 mm. Microscopic analyses of prokaryotic cells of a stratified mat in Pond 5 (collected in 2004) showed filamentous bacteria and cyanobacteria with a cell abundance and morphotype richness maxima of prokaryotic cells in a chemocline from 3 mm to 7 mm depth which co-exists nine morphotypes of aerobic and anaerobic prokaryotes Microcoleus chthonoplastes, Leptolyngbya, Cyanothece, Geitlerinema, Spirulina, Chloroflexus, Beggiatoa, Chromatium and Thioploca. Below the 7 mm depth, oxygenic photosynthesis depletes and sulfur reducing compounds increase. The highs of the shale-normalized lanthanide contents of the 'group A' (at 15 mm depth) seem to correlate with the

  13. Amino Acid Coding Bias of the Hypersaline Dead Sea on an Environmental Scale

    NASA Astrophysics Data System (ADS)

    Rhodes, M. E.; Fitz-Gibbon, S.; Bodaker, I.; Beja, O.; Oren, A.; House, C.

    2008-12-01

    relatively diverse hypersaline environment to one in which only the most extreme of hyperhalophiles could cope. It also suggests that the amino acid composition of the microbial community of an environment can serve as a proxy for salinity and potentially other environmental factors as well.

  14. Diversity, distribution, and morphological deformities among living Foraminifera in hypersaline Salwa Bay, Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Olalekan Amao, Abduljamiu; Kaminski, Michael

    2016-04-01

    The Arabian Gulf is considered a naturally stressed environment due to extremes of salinity and summer temperatures. Anthropogenic influences such as rapid urbanisation projects, maritime transport, and large numbers of desalination plants and oil-related activities compounds the problem. Foraminifera are known to be resilient under such stressful conditions. The purpose of our study is to document the foraminiferal diversity and abundance in the hypersaline Salwa Bay area, near the Saudi Arabian-Qatar Border. We expect the foraminiferal fauna in Salwa Bay to be adapted to extremes in salinity, and we wish to document any species that might be endemic or uniquely adapted to the area. Shannon-Wiener index, relative abundance, species richness, and the percentage of morphological deformities were determined for samples collected from the bay. Salwa Bay is the most saline extension of the Arabian Gulf with high salinity, water temperature and evaporation rate, which is attributed to slow flushing rates, coral reef barriers and higher residency time of the water. Environmental parameters measured at the time of collection were depth (10-110 cm), salinity (52.6-53.0) total dissolved solids (48.8-49.4 g/l), and temperature (27-27.6°C). The foraminiferal assemblages in Salwa Bay are dominated by porcelaneous foraminifera, which include Peneroplis pertusus, Peneroplis planatus, Coscinospira hemprichii and Coscinospira acicularis. The most common species across the sampled transect is Peneroplis pertusus. Hyaline species were also found, but agglutinated foraminifera are absent. Diversity in Salwa Bay is lower compared with localities that have "normal" salinity, and many of the foraminifera display conspicuous morphological deformities. Approximately 55% of the assemblage exhibits mild to severe deformities such as fusion of two adults or double tests, protuberance on the spiral side, abnormal arrangement of the chambers, abnormal shape of the proloculus and modification

  15. Gas exchange on Mono Lake and Crowley Lake, California

    NASA Technical Reports Server (NTRS)

    Wanninkhof, Rik; Ledwell, James R.; Broecker, Wallace S.

    1987-01-01

    Gas exchange coefficients (k) have been determined for freshwater Crowley Lake and saline Mono Lake through the use of a man-made purposefully injected gas, SF6. The concentration decreased from an initial value of 40 to 4 pmol/L for Mono Lake and from 20 to 1 pmol/L for Crowley lake over a period of 6 wks. Wind-speed (u) records from anemometers on the shore of each lake made it possible to determine the relationship between k and u. The average u and k values for the experiment were identical for the two lakes, despite the large chemical differences. It is estimated that, for the u values observed over Mono Lake from July to December 1984, the exchange of CO2 occurred 2.5 times faster than without chemical enhancement. This is a factor of 4 lower than needed to explain the high invasion rate of C-14 produced by nuclear bomb tests.

  16. Mono-isotope Prediction for Mass Spectra Using Bayes Network

    PubMed Central

    Li, Hui; Rwebangira, Mugizi Robert; Burge, Legand

    2015-01-01

    Mass spectrometry is one of the widely utilized important methods to study protein functions and components. The challenge of mono-isotope pattern recognition from large scale protein mass spectral data needs computational algorithms and tools to speed up the analysis and improve the analytic results. We utilized naïve Bayes network as the classifier with the assumption that the selected features are independent to predict mono-isotope pattern from mass spectrometry. Mono-isotopes detected from validated theoretical spectra were used as prior information in the Bayes method. Three main features extracted from the dataset were employed as independent variables in our model. The application of the proposed algorithm to publicMo dataset demonstrates that our naïve Bayes classifier is advantageous over existing methods in both accuracy and sensitivity. PMID:25620856

  17. Degradation of mono-fluorophenols by an acclimated activated sludge.

    PubMed

    Chaojie, Zhang; Qi, Zhou; Ling, Chen; Yuan, Yuan; Hui, Yu

    2007-02-01

    Acclimated activated sludge was examined for its ability to degrade mono-fluorophenols as the sole carbon source in aerobic batch cultures. The acclimated activated sludge degraded fluorophenol efficiently. It degraded 100 mg/l 3-fluoropheno and 4-fluorophenol in 16 h with, respectively, 99.85% and 99.91% fluoride anion release and it degraded 50 mg/l 2-fluorophenol in 15 h with 99.26% fluoride anion release. The aerobic biodegradability of the mono-fluorophenols decreased in the order: 4-fluorophenol > 3-fluorophenol > 2-fluorophenol, resulting mainly from a different octanol/water partition coefficient and different steric parameter of the fluorophenols. The mechanism study revealed that the initial step in the aerobic biodegradation of mono-fluorophenols by the activated sludge was their transformation to fluorocatechol. Following transformation of the fluorophenol to fluorocatechol, ring cleavage by catechol 1, 2-dioxygenases proceeded via an ortho-cleavage pathway, then defluorination occurred. PMID:16819592

  18. [Immediately loaded MonoType implants in the edentulous mandible].

    PubMed

    Gfeller, F; Zitzmann, N U; Lambrecht, J Thomas

    2011-01-01

    Results of immediately loaded implants are presented. 34 patients with 136 interforaminal MonoType implants (Straumann,Basel, Switzerland) were included in the study. The bar retention was manufactured fter the operation, inserted and covered with a hybrid prosthesis. 28 patients showed up for the follow-up study, the average time range was three years. Five implants were rated as failures, the cumulative six-year success rate being 94%. Interforaminal immediately loaded MonoType implants in edentulous patients showed very good results, comparable to similar studies with different systems. PMID:21560796

  19. Anode conductor for alkaline cells

    SciTech Connect

    Schrenk, D.J.; Murphy, P.E.

    1988-12-13

    This patent describes an electrochemical cell comprised of an anode comprised of zinc; a cathode; and alkaline electrolyte; and a current collector comprised of a silicon bronze alloy that is comprised of 85-98% by weight copper and 1-5% by weight silicon with the remainder being comprised of at least one of manganese, iron, zinc, aluminum, tin, lead, or mixtures thereof; and a strip of metal tab stock welded to the current collector, the tab stock being a metal other than silicon bronze alloy.

  20. Alkaline fuel cell performance investigation

    NASA Technical Reports Server (NTRS)

    Martin, R. E.; Manzo, M. A.

    1988-01-01

    An exploratory experimental fuel cell test program was conducted to investigate the performance characteristics of alkaline laboratory research electrodes. The objective of this work was to establish the effect of temperature, pressure, and concentration upon performance and evaluate candidate cathode configurations having the potential for improved performance. The performance characterization tests provided data to empirically establish the effect of temperature, pressure, and concentration upon performance for cell temperatures up to 300 F and reactant pressures up to 200 psia. Evaluation of five gold alloy cathode catalysts revealed that three doped gold alloys had more than two times the surface areas of reference cathodes and therefore offered the best potential for improved performance.

  1. Alkaline fuel cell performance investigation

    NASA Technical Reports Server (NTRS)

    Martin, R. E.; Manzo, M. A.

    1988-01-01

    An exploratory experimental fuel cell test program was conducted to investigate the performance characteristics of alkaline laboratory research electrodes. The objective of this work was to establish the effect of temperature, pressure, and concentration upon performance and evaluate candidate cathode configurations having the potential for improved performance. The performance characterization tests provided data to empirically establish the effect of temperature, pressure, and concentration upon performance for cell temperatures up to 300 F and reactant pressures up to 200 psia. Evaluation of five gold alloy cathode catalysts revealed that three doped gold alloys had more that two times the surface areas of reference cathodes and therefore offered the best potential for improved performance.

  2. Alkaline detergent recycling via ultrafiltration

    SciTech Connect

    Steffani, C.; Meltzer, M.

    1995-06-01

    The metal finishing industry uses alkaline cleaners and detergents to remove oils and dirt from manufactured parts, often before they are painted or plated. The use of these cleaners has grown because environmental regulations are phasing out ozone depleting substances and placing restrictions on the use and disposal of many hazardous solvents. Lawrence Livermore National Laboratory is examining ultrafiltration as a cleaning approach that reclaims the cleaning solutions and minimizes wastes. The ultrafiltration membrane is made from sheets of polymerized organic film. The sheets are rolled onto a supporting frame and installed in a tube. Spent cleaning solution is pumped into a filter chamber and filtered through the membrane that captures oils and dirt and allows water and detergent to pass. The membrane is monitored and when pressure builds from oil and dirt, an automatic system cleans the surface to maintain solution flow and filtration quality. The results show that the ultrafiltration does not disturb the detergent concentration or alkalinity but removed almost all the oils and dirt leaving the solution in condition to be reused.

  3. Grace DAKASEP alkaline battery separator

    NASA Technical Reports Server (NTRS)

    Giovannoni, R. T.; Lundquist, J. T.; Choi, W. M.

    1987-01-01

    The Grace DAKASEP separator was originally developed as a wicking layer for nickel-zinc alkaline batteries. The DAKASEP is a filled non-woven separator which is flexible and heat sealable. Through modification of formulation and processing variables, products with a variety of properties can be produced. Variations of DAKASEP were tested in Ni-H2, Ni-Zn, Ni-Cd, and primary alkaline batteries with good results. The properties of DAKASEP which are optimized for Hg-Zn primary batteries are shown in tabular form. This separator has high tensile strength, 12 micron average pore size, relatively low porosity at 46-48 percent, and consequently moderately high resistivity. Versions were produced with greater than 70 percent porosity and resistivities in 33 wt percent KOH as low as 3 ohm cm. Performance data for Hg-Zn E-1 size cells containing DAKASEP with the properties shown in tabular form, are more reproducible than data obtained with a competitive polypropylene non-woven separator. In addition, utilization of active material is in general considerably improved.

  4. Functional Role of Native and Invasive Filter-Feeders, and the Effect of Parasites: Learning from Hypersaline Ecosystems

    PubMed Central

    Green, Andy J.

    2016-01-01

    Filter-feeding organisms are often keystone species with a major influence on the dynamics of aquatic ecosystems. Studies of filtering rates in such taxa are therefore vital in order to understand ecosystem functioning and the impact of natural and anthropogenic stressors such as parasites, climate warming and invasive species. Brine shrimps Artemia spp. are the dominant grazers in hypersaline systems and are a good example of such keystone taxa. Hypersaline ecosystems are relatively simplified environments compared with much more complex freshwater and marine ecosystems, making them suitable model systems to address these questions. The aim of this study was to compare feeding rates at different salinities and temperatures between clonal A. parthenogenetica (native to Eurasia and Africa) and the invasive American brine shrimp A. franciscana, which is excluding native Artemia from many localities. We considered how differences observed in laboratory experiments upscale at the ecosystem level across both spatial and temporal scales (as indicated by chlorophyll-a concentration and turbidity). In laboratory experiments, feeding rates increased at higher temperatures and salinities in both Artemia species and sexes, whilst A. franciscana consistently fed at higher rates. A field study of temporal dynamics revealed significantly higher concentrations of chlorophyll-a in sites occupied by A. parthenogenetica, supporting our experimental findings. Artemia parthenogenetica density and biomass were negatively correlated with chlorophyll-a concentration at the spatial scale. We also tested the effect of cestode parasites, which are highly prevalent in native Artemia but much rarer in the invasive species. The cestodes Flamingolepis liguloides and Anomotaenia tringae decreased feeding rates in native Artemia, whilst Confluaria podicipina had no significant effect. Total parasite prevalence was positively correlated with turbidity. Overall, parasites are likely to reduce

  5. Functional Role of Native and Invasive Filter-Feeders, and the Effect of Parasites: Learning from Hypersaline Ecosystems.

    PubMed

    Sánchez, Marta I; Paredes, Irene; Lebouvier, Marion; Green, Andy J

    2016-01-01

    Filter-feeding organisms are often keystone species with a major influence on the dynamics of aquatic ecosystems. Studies of filtering rates in such taxa are therefore vital in order to understand ecosystem functioning and the impact of natural and anthropogenic stressors such as parasites, climate warming and invasive species. Brine shrimps Artemia spp. are the dominant grazers in hypersaline systems and are a good example of such keystone taxa. Hypersaline ecosystems are relatively simplified environments compared with much more complex freshwater and marine ecosystems, making them suitable model systems to address these questions. The aim of this study was to compare feeding rates at different salinities and temperatures between clonal A. parthenogenetica (native to Eurasia and Africa) and the invasive American brine shrimp A. franciscana, which is excluding native Artemia from many localities. We considered how differences observed in laboratory experiments upscale at the ecosystem level across both spatial and temporal scales (as indicated by chlorophyll-a concentration and turbidity). In laboratory experiments, feeding rates increased at higher temperatures and salinities in both Artemia species and sexes, whilst A. franciscana consistently fed at higher rates. A field study of temporal dynamics revealed significantly higher concentrations of chlorophyll-a in sites occupied by A. parthenogenetica, supporting our experimental findings. Artemia parthenogenetica density and biomass were negatively correlated with chlorophyll-a concentration at the spatial scale. We also tested the effect of cestode parasites, which are highly prevalent in native Artemia but much rarer in the invasive species. The cestodes Flamingolepis liguloides and Anomotaenia tringae decreased feeding rates in native Artemia, whilst Confluaria podicipina had no significant effect. Total parasite prevalence was positively correlated with turbidity. Overall, parasites are likely to reduce

  6. 21 CFR 172.834 - Ethoxylated mono- and diglycerides.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethoxylated mono- and diglycerides. 172.834 Section 172.834 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives...

  7. 21 CFR 172.834 - Ethoxylated mono- and diglycerides.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ethoxylated mono- and diglycerides. 172.834 Section 172.834 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives...

  8. 21 CFR 172.834 - Ethoxylated mono- and diglycerides.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ethoxylated mono- and diglycerides. 172.834 Section 172.834 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives...

  9. Air quality in bedded mono-slope beef barns

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bedded mono-slope barns are becoming more common in the upper Midwest. Because these are new facilities, little research has been published regarding environmental quality, building management and animal performance in these facilities. A team of researchers from South Dakota State University, USDA ...

  10. TOXICOLOGY OF MONO- AND DI-ALKYLTIN CHLORIDES.

    EPA Science Inventory

    Mono- and di-alkyltin chlorides are reactive compounds used in the production of stabilizers for polyvinyl chloride (PVC) plastics, primarily used for water distribution pipes. Health effects data were compiled or developed by the manufacturers for the EPA's HPV Challenge progra...

  11. TOXICOLOGY OF MONO- AND DI-ALKYLTIN CHLORIDES

    EPA Science Inventory

    Mono- and di-alkyltin chlorides are reactive compounds used in the production of stabilizers for polyvinyl chloride (PVC) plastics, primarily used for water distribution pipes. Health effects data were compiled or developed by the manufacturers for the EPA's HPV Challenge progra...

  12. Alkaline and alkaline earth metal phosphate halides and phosphors

    SciTech Connect

    Lyons, Robert Joseph; Setlur, Anant Achyut; Cleaver, Robert John

    2012-11-13

    Compounds, phosphor materials and apparatus related to nacaphite family of materials are presented. Potassium and rubidium based nacaphite family compounds and phosphors designed by doping divalent rare earth elements in the sites of alkaline earth metals in the nacaphite material families are descried. An apparatus comprising the phosphors based on the nacaphite family materials are presented herein. The compounds presented is of formula A.sub.2B.sub.1-yR.sub.yPO.sub.4X where the elements A, B, R, X and suffix y are defined such that A is potassium, rubidium, or a combination of potassium and rubidium and B is calcium, strontium, barium, or a combination of any of calcium, strontium and barium. X is fluorine, chlorine, or a combination of fluorine and chlorine, R is europium, samarium, ytterbium, or a combination of any of europium, samarium, and ytterbium, and y ranges from 0 to about 0.1.

  13. Geophysical studies of Mono Lake, east-central California

    NASA Astrophysics Data System (ADS)

    Athens, N. D.; Ponce, D. A.

    2012-12-01

    Magnetic and gravity investigations were undertaken in Mono Lake, California to study regional crustal structures and to aid understanding the geologic framework of Mono Lake, in particular regarding potential geothermal resources and volcanic hazards throughout Mono Basin. Recent geophysical surveys included over 600 line-kilometers of high-resolution ship-borne magnetometer data that augmented existing airborne data, 22 line-kilometers of ground magnetic data that were collected along six traverses across Paoha Island, 56 gravity stations that were collected on Paoha and Negit Islands, and 28 rock samples that were collected for physical property data. Magnetic highs in the study area occur to the east and west of Mono Lake, where pre-Tertiary basement is exposed. Magnetic data indicate that Mono Lake itself is dominated by three prominent magnetic anomalies that are from west to east: a magnetic high along the northwest part of the lake associated with the moderately magnetic basalt cinder cone at Black Point, a magnetic high associated with the young volcanic centers at Paoha and Negit Islands, and a broad magnetic high along the eastern margin of the lake probably associated with moderately magnetic granitic basement rocks at depth. Because volcanic rocks exposed at the surface of Paoha and Negit Islands are only weakly magnetic, magnetic data suggest that more mafic volcanic rocks probably occur at depth and are the source of the anomaly. The linear and steep magnetic gradient across the eastern part of the lake may reflect a fault. A fault may also be imaged in the northeastern part of the lake, where a possible laterally offset magnetic anomaly may be present. Within Mono Lake, gravity station control is poor because land-based gravity stations are limited to Paoha and Negit Islands. The gravity low in the basin reflects a moderately deep sedimentary basin filled with low density lacustrine and volcanic deposits. Isostatic gravity data indicate the central

  14. Rare earth element and uranium-thorium variations in tufa deposits from the Mono Basin, CA

    NASA Astrophysics Data System (ADS)

    Wilcox, E. S.; Tomascak, P. B.; Hemming, N.; Hemming, S. R.; Rasbury, T.; Stine, S.; Zimmerman, S. R.

    2009-12-01

    Samples of fossil tufa deposits from several localities in the Mono Basin, eastern California, were analyzed for trace element concentrations in order to better understand changes in lake composition in the past. These deposits were formed during the last glacial cycle, mostly during deglaciation (Benson et al., 1990, PPP). Three elevations are represented by the analyses. Samples from near Highway 167 were sampled between 2063 and 2069 m asl. Samples from near Thompson Road were sampled between 2015 and 2021 m. One layered mound was sampled at 1955 m. Concentrations of the lanthanide rare earth elements (REE), in particular the heavy/light (HREE/LREE) distributions, have been shown to be sensitive to alkalinity in modern saline lakes (e.g., Johannesson et al., 1994, GRL, 21, 773-776), and the same has been suggested for U/Th (Anderson et al., 1982, Science, 216, 514-516). Holocene to near-modern tufa towers exist in shallow water and around the current shoreline (1945 m). Tufa towers above 2000 m include a characteristic morphology termed thinolite, interpreted to represent pseudomorphs after the very cold water mineral ikaite. Most lower elevation towers do not have the thinolite morphology, but some layered tufa mounds at low elevations include several layers of thinolite, such as the one sampled for this project. Analyses were made on millimeter-scale bulk samples from tufa towers. Measurements were made on sample solutions with a Varian 820MS quadrupole ICP-MS. Mono Basin tufa samples have total REE concentrations ranging from 0.029 to 0.77 times average shales. Samples have flat to moderately HREE-enriched shale-normalized patterns with limited overall variability ([La/Lu]SN of 1.8 to 9.6) but with some variability in the slope of the HREE portion of the patterns. Tufa towers sampled from three elevations have (Gd/Lu)SN of 0.40 to 1.5. The REE patterns of most samples have small positive Ce anomalies, but a minority of samples, all from the layered tufa mound

  15. Lipid Biomarkers for Methanogens in Hypersaline Cyanobacterial Mats for Guerrero Negro, Baja California Sur

    NASA Technical Reports Server (NTRS)

    Jahnke, Linda L.; Embaye, Tsegereda; Summons, Roger E.; Fonda, Mark (Technical Monitor)

    2002-01-01

    Analyses of sediments from the vicinity of active methane seeps have uncovered a particular suite of lipid biomarker patterns that characterize methane consuming archaea and their syntrophic, sulfate reducing partners. These isoprenoid biomarkers, largely identified by their anomalously light carbon isotopic signatures, have been a topic of intense research activity and are recorded in numerous methane-rich environments from Holocene to Cenozoic. This phenomenon has implications for depleted kerogens at 2.7 Ga on early Earth (Hinrichs 2002). In contrast, the lipid biosignatures of methane producing archaea are not readily identified through distinct isotopic labels and have received comparably little attention in analyses of archaea in environmental samples. Indeed, environmental analyses generally detect only free archaeal lipids, not the intact, polar molecules found in the membrane of living organisms. As part of the Ames NAI, the 'Early Microbial Ecosystem Research Group' (EMERG) is working to understand microbial processes in the hypersaline cyanobacterial mats growing in the salt evaporation ponds of the Exportadora de Sal at Guerrero Negro, Baja California Sur, Mexico. The aim of this study was to develop methods by which we could identify the organisms responsible for methane generation in this environment. While the ester-bound fatty acids, hopanoids and wax esters provide a means to identify most of the bacterial components of these mats, the archaea which Ere evidently present through genomic assays and the fact of intense methane production (Hoehler et al. 200l), have not been identified through their corresponding lipid signatures. Archaeal core lipids present a number of analytical challenges. The core lipids of methanogens comprise C20, C40 and sometimes C25 isoprenoid chains, linked through ether bonds to glycerol. As well as archaeal (C20), sn-2- and sn-3-hydroxyarchaeol are associated particularly with methylotrophic methanogens. Recently, we have

  16. Chemical, crystallographic and stable isotopic properties of alunite and jarosite from acid-Hypersaline Australian lakes

    USGS Publications Warehouse

    Alpers, C.N.; Rye, R.O.; Nordstrom, D.K.; White, L.D.; King, B.-S.

    1992-01-01

    Chemical, crystallographic and isotopic analyses were made on samples containing alunite and jarosite from the sediments of four acid, hypersaline lakes in southeastern and southwestern Australia. The alunite and jarosite are K-rich with relatively low Na contents based on chemical analysis and determination of unit cell dimensions by powder X-ray diffraction. Correcting the chemical analyses of fine-grained mineral concentrates from Lake Tyrrell, Victoria, for the presence of halite, silica and poorly crystalline aluminosilicates, the following formulas indicate best estimates for solid-solution compositions: for alunite, K0.87Na0.04(H3O)0.09(Al 0.92Fe0.08)3(SO4)2(OH) 6 and for jarosite, K0.89Na0.07(H3O)0.04(Fe 0.80Al0.20)3(SO4)2(OH) 6. The ??D-values of alunite are notably larger than those for jarosite from Lake Tyrrell and it appears that the minerals have closely approached hydrogen isotope equilibrium with the acidic regional groundwaters. The ??D results are consistent with a fractionation ???60-70??? between alunite and jarosite observed in other areas. However, interpretation of ??D results is complicated by large variability in fluid ??DH2O from evaporation, mixing and possible ion hydration effects in the brine. ??D-values of water derived from jarosite by step-wise heating tend to be smaller at 250??C, at which temperature hydronium and other non-hydroxyl water is liberated, than at 550??C, where water is derived from the hydroxyl site, but the differences are not sufficiently different to invalidate measurements of total ??D obtained by conventional, single-step heating methods. ??34S-values for alunite and jarosite from the four lakes (+19.7 to +21.2??? CDT) and for aqueous sulfate from Lake Tyrrell (+18.3 to +19.8???) are close to the values for modern evaporites (+21.5 ??0.3???) and seawater (+20??0.5???) and are probably typical of seawater-derived aerosols in arid coastal environments. ??34-S-values slightly smaller than that for seawater may

  17. Spatially-resolved carbon flow through a hypersaline phototrophic microbial mat

    NASA Astrophysics Data System (ADS)

    Moran, J.; Lindemann, S. R.; Cory, A. B.; Courtney, S.; Cole, J. K.; Fredrickson, J.

    2013-12-01

    Hot Lake is a hypersaline, meromictic lake located in an endorheic basin in north-central Washington. Low annual rainfall and high evaporation rates contribute to the lake's high salinity. The predominant dissolved salt is magnesium sulfate, of which monimolimnion waters may seasonally exceed 2 M concentrations. Induced by its high salinity and meromictic nature, Hot Lake displays an inverse thermal gradient with deep horizons seasonally exceeding 50 °C. Despite extreme conditions, dense benthic microbial mats composed of cyanobacteria, anoxygenic photoheterotrophs, and bacterial heterotroph populations develop in the lake. These mats can exceed 1 cm in thickness and display vertical stratification in color due to bacterial pigmentation. Typical mat stratification includes an orange surface layer underlain by green and purple layers at increasing depth. Carbonates, including aragonite and magnesite, are observed within the mat and their formation is likely induced or influenced by microbial metabolic activities and associated pH excursions. We are exploring the role Hot Lake's microbial mats play in carbon cycling. Cyanobacteria are the dominant CO2-fixing organisms in the mat and we seek to understand the spatial and metabolic controls on how the carbon initially fixed by mat cyanobacteria is transferred to associated heterotrophic populations spread throughout the mat strata. Secondly, we seek to understand the overall net carbon balance of the mat through a growing season. We are using a stable isotope probing approach for assessing carbon uptake and migration through representative mat samples. We performed a series of ex situ incubations of freshly harvested mat samples in lake water amended with 13C-labeled bicarbonate or substrates commonly consumed by heterotrophs (including acetate and glucose) and using multiple stable isotope techniques to track label uptake, residence time, remineralization, and location within the mat. In addition to bulk isotope

  18. Quaternary Eruptions of the Mono-Inyo Craters, California

    NASA Astrophysics Data System (ADS)

    Bursik, M. I.; Pouget, S.; Mangan, M.; Marcaida, M.; Vazquez, J. A.

    2013-12-01

    The eruptive products of the Mono-Inyo Craters volcanic chain include the tephra and associated volcanic rocks of Black Point, islands of Mono Lake, Mono Craters, Inyo Craters, late eruptions of Mammoth Mountain and Red Cones. Most of the eruptions were explosive, and generated numerous pyroclastic flows, surges and falls as well as the prominent domes and lava flows that now cover vents. The eruptions range in age from several hundred years to at least 60,000 yr BP. The Mono-Inyo tephras are dispersed throughout the Sierra Nevada and Basin and Range, providing key time-stratigraphic marker layers. Recent work has not only resulted in high-precision radiometric dating of many of the tephras, but also detailed geochemical data that for the first time provides fingerprinting sufficiently precise to discriminate among the tephras. Lithostratigraphy of many of the layers is herein described for the first time, based on careful sampling and description in the field, and laboratory grain size, grain shape and componentry analyses of the late Pleistocene tephras of the Wilson Creek Formation. Most of the Wilson Creek volcanic layers are fall deposits accumulated within paleolake Russell, which were generated by eruptions of variable intensity and influenced by paleowinds of different orientation. Prevailing winds were generally to the North and East, but often the Pleistocene layers less than 25 ka were dispersed to the West. Many of the fall layers show evidence of wave reworking, generally near the top, although in some cases it is pervasive. Only near the vent do some layers of apparent debris flow origin occur. Maximum pumice sizes range up to nearly 3 cm, and lithics range up to 1 cm in the rhyolitic fall beds, while thicknesses range up to c. 30 cm. These data are consistent with relatively low volume, subplinian style eruptive behavior for most of the life of the Mono-Inyo Craters.

  19. Community structure and activity of a highly dynamic and nutrient-limited hypersaline microbial mat in Um Alhool Sabkha, Qatar.

    PubMed

    Al-Thani, Roda; Al-Najjar, Mohammad A A; Al-Raei, Abdul Munem; Ferdelman, Tim; Thang, Nguyen M; Al Shaikh, Ismail; Al-Ansi, Mehsin; de Beer, Dirk

    2014-01-01

    The Um Alhool area in Qatar is a dynamic evaporative ecosystem that receives seawater from below as it is surrounded by sand dunes. We investigated the chemical composition, the microbial activity and biodiversity of the four main layers (L1-L4) in the photosynthetic mats. Chlorophyll a (Chl a) concentration and distribution (measured by HPLC and hyperspectral imaging, respectively), the phycocyanin distribution (scanned with hyperspectral imaging), oxygenic photosynthesis (determined by microsensor), and the abundance of photosynthetic microorganisms (from 16S and 18S rRNA sequencing) decreased with depth in the euphotic layer (L1). Incident irradiance exponentially attenuated in the same zone reaching 1% at 1.7-mm depth. Proteobacteria dominated all layers of the mat (24%-42% of the identified bacteria). Anoxygenic photosynthetic bacteria (dominated by Chloroflexus) were most abundant in the third red layer of the mat (L3), evidenced by the spectral signature of Bacteriochlorophyll as well as by sequencing. The deep, black layer (L4) was dominated by sulfate reducing bacteria belonging to the Deltaproteobacteria, which were responsible for high sulfate reduction rates (measured using 35S tracer). Members of Halobacteria were the dominant Archaea in all layers of the mat (92%-97%), whereas Nematodes were the main Eukaryotes (up to 87%). Primary productivity rates of Um Alhool mat were similar to those of other hypersaline microbial mats. However, sulfate reduction rates were relatively low, indicating that oxygenic respiration contributes more to organic material degradation than sulfate reduction, because of bioturbation. Although Um Alhool hypersaline mat is a nutrient-limited ecosystem, it is interestingly dynamic and phylogenetically highly diverse. All its components work in a highly efficient and synchronized way to compensate for the lack of nutrient supply provided during regular inundation periods. PMID:24658360

  20. Community Structure and Activity of a Highly Dynamic and Nutrient-Limited Hypersaline Microbial Mat in Um Alhool Sabkha, Qatar

    PubMed Central

    Al-Thani, Roda; Al-Najjar, Mohammad A. A.; Al-Raei, Abdul Munem; Ferdelman, Tim; Thang, Nguyen M.; Shaikh, Ismail Al; Al-Ansi, Mehsin; de Beer, Dirk

    2014-01-01

    The Um Alhool area in Qatar is a dynamic evaporative ecosystem that receives seawater from below as it is surrounded by sand dunes. We investigated the chemical composition, the microbial activity and biodiversity of the four main layers (L1–L4) in the photosynthetic mats. Chlorophyll a (Chl a) concentration and distribution (measured by HPLC and hyperspectral imaging, respectively), the phycocyanin distribution (scanned with hyperspectral imaging), oxygenic photosynthesis (determined by microsensor), and the abundance of photosynthetic microorganisms (from 16S and 18S rRNA sequencing) decreased with depth in the euphotic layer (L1). Incident irradiance exponentially attenuated in the same zone reaching 1% at 1.7-mm depth. Proteobacteria dominated all layers of the mat (24%–42% of the identified bacteria). Anoxygenic photosynthetic bacteria (dominated by Chloroflexus) were most abundant in the third red layer of the mat (L3), evidenced by the spectral signature of Bacteriochlorophyll as well as by sequencing. The deep, black layer (L4) was dominated by sulfate reducing bacteria belonging to the Deltaproteobacteria, which were responsible for high sulfate reduction rates (measured using 35S tracer). Members of Halobacteria were the dominant Archaea in all layers of the mat (92%–97%), whereas Nematodes were the main Eukaryotes (up to 87%). Primary productivity rates of Um Alhool mat were similar to those of other hypersaline microbial mats. However, sulfate reduction rates were relatively low, indicating that oxygenic respiration contributes more to organic material degradation than sulfate reduction, because of bioturbation. Although Um Alhool hypersaline mat is a nutrient-limited ecosystem, it is interestingly dynamic and phylogenetically highly diverse. All its components work in a highly efficient and synchronized way to compensate for the lack of nutrient supply provided during regular inundation periods. PMID:24658360

  1. Hypersalinity reduces the risk of cyanide toxicosis to insectivorous bats interacting with wastewater impoundments at gold mines.

    PubMed

    Griffiths, Stephen R; Donato, David B; Lumsden, Linda F; Coulson, Graeme

    2014-01-01

    Wildlife and livestock that ingest bioavailable cyanide compounds in gold mining tailings dams are known to experience cyanide toxicosis. Elevated levels of salinity in open impoundments have been shown to prevent wildlife cyanide toxicosis by reducing drinking and foraging. This finding appears to be consistent for diurnal wildlife interacting with open impoundments, however the risks to nocturnal wildlife of cyanide exposure are unknown. We investigated the activity of insectivorous bats in the airspace above both fresh (potable to wildlife) and saline water bodies at two gold mines in the goldfields of Western Australian. During this study, cyanide-bearing solutions stored in open impoundments at both mine sites were hypersaline (range=57,000-295,000 mg/L total dissolved solids (TDS)), well above known physiological tolerance of any terrestrial vertebrate. Bats used the airspace above each water body monitored, but were more active at fresh than saline water bodies. In addition, considerably more terminal echolocation buzz calls were recorded in the airspace above fresh than saline water bodies at both mine sites. However, it was not possible to determine whether these buzz calls corresponded to foraging or drinking bouts. No drinking bouts were observed in 33 h of thermal video footage recorded at one hypersaline tailings dam, suggesting that this water is not used for drinking. There is no information on salinity tolerances of bats, but it could be assumed that bats would not tolerate salinity in drinking water at concentrations greater than those documented as toxic for saline-adapted terrestrial wildlife. Therefore, when managing wastewater impoundments at gold mines to avoid wildlife mortalities, adopting a precautionary principle, bats are unlikely to drink solutions at salinity levels ≥50,000 mg/L TDS. PMID:24176292

  2. 21 CFR 172.856 - Propylene glycol mono- and diesters of fats and fatty acids.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Propylene glycol mono- and diesters of fats and... CONSUMPTION Multipurpose Additives § 172.856 Propylene glycol mono- and diesters of fats and fatty acids. Propylene glycol mono- and diesters of fats and fatty acids may be safely used in food, subject to...

  3. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Polyethylene glycol (400) mono- and dioleate. 573... DRINKING WATER OF ANIMALS Food Additive Listing § 573.800 Polyethylene glycol (400) mono- and dioleate. (a) The food additive polyethylene glycol (400) mono- and dioleate meets the following...

  4. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Polyethylene glycol (400) mono- and dioleate. 573... DRINKING WATER OF ANIMALS Food Additive Listing § 573.800 Polyethylene glycol (400) mono- and dioleate. (a) The food additive polyethylene glycol (400) mono- and dioleate meets the following...

  5. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Polyethylene glycol (400) mono- and dioleate. 573... DRINKING WATER OF ANIMALS Food Additive Listing § 573.800 Polyethylene glycol (400) mono- and dioleate. (a) The food additive polyethylene glycol (400) mono- and dioleate meets the following...

  6. 21 CFR 184.1101 - Diacetyl tartaric acid esters of mono- and diglycerides.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Diacetyl tartaric acid esters of mono- and... acid esters of mono- and diglycerides. (a) Diacetyl tartaric acid esters of mono- and diglycerides... groups of glycerin has been esterified by diacetyl tartaric acid and by fatty acids. The ingredient...

  7. 40 CFR 721.8340 - Mono esters from 2- propenoic acid (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Mono esters from 2- propenoic acid... Specific Chemical Substances § 721.8340 Mono esters from 2- propenoic acid (generic). (a) Chemical... as mono esters from 2-propenoic acid (PMN P-01-85) is subject to reporting under this section for...

  8. 40 CFR 721.8340 - Mono esters from 2- propenoic acid (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Mono esters from 2- propenoic acid... Specific Chemical Substances § 721.8340 Mono esters from 2- propenoic acid (generic). (a) Chemical... as mono esters from 2-propenoic acid (PMN P-01-85) is subject to reporting under this section for...

  9. The Magma Transport System of the Mono Craters, California

    NASA Astrophysics Data System (ADS)

    Johnson, M. R.; Putirka, K. D.

    2013-12-01

    The Mono Craters are a series of 28 volcanic domes, coulees, and craters, just 16 km north of Long Valley. The magmatic products of the Mono Craters include mostly small magmatic bodies, sills, and dikes set in a transtensional tectonic setting. New high-density sampling of the domes reveals a wider range of magma compositions than heretofore recognized, and thus reveals what is likely a more complex magmatic system, involving a greater number of batches of magma and a more complex magma storage/delivery system. Here, we present a model for the magma plumbing system based on space-composition patterns and preliminary estimates of crystallization temperatures and pressures based on olivine-, feldspar- and clinopyroxene-liquid equilibria. Whole rock analyses show three compositionally distinct batches of magma within the Mono Craters proper: a felsic (73-78.4% SiO2), intermediate (64.4-68% SiO2) and mafic (52.7-61% SiO2) group. The Mono Lake Islands (Paoha and Negit) fall into the intermediate group, but contain distinctly lower TiO2 and Fe2O3 at a given SiO2 compared to all other Mono Craters; on this basis, we surmise that the Paoha and Negit eruptions represent a distinct episode of magmatism that is not directly related to the magmatic activity that created the Mono Craters proper. The discontinuous nature of the three groups indicates that magma mixing, while evident to some degree within and between certain domes, did not encompass the entire range of compositions at any given time. The three groups, however, do form a rough linear trend, and some subsets of domes have compositions that fall on distinctly linear (if still discontinuous) trends that cannot be reproduced by fractional crystallization, but rather are indicative of magma mixing. Our high-density sampling also reveals interesting geographical patterns: for example, felsic magmas erupt throughout the entire Mono Craters chain, erupting at a wide range of temperatures, ranging from 650-995°C, but

  10. Process for extracting technetium from alkaline solutions

    SciTech Connect

    Moyer, B.A.; Sachleben, R.A.; Bonnesen, P.V.

    1994-12-31

    This invention relates generally to a process for extracting technetium from nuclear wastes and more particularly to a process for extracting technetium from alkaline waste solutions containing technetium and high concentrations of alkali metal nitrates. A process for extracting technetium values from an aqueous alkaline solution containing at least one alkali metal hydroxide and at least one alkali metal nitrate comprises the steps of: contacting the aqueous alkaline solution with a solvent consisting of a crown ether in a diluent, the diluent being a water-immiscible organic liquid in which the crown ether is soluble, for a period of time sufficient to selectively extract the technetium values from the aqueous alkaline solution into the solvent; separating the solvent containing the technetium values from the aqueous alkaline solution; and stripping the technetium values from the solvent by contacting the solvent with water.

  11. Alkaline-resistance model of subtilisin ALP I, a novel alkaline subtilisin.

    PubMed

    Maeda, H; Mizutani, O; Yamagata, Y; Ichishima, E; Nakajima, T

    2001-05-01

    The alkaline-resistance mechanism of the alkaline-stable enzymes is not yet known. To clarify the mechanism of alkaline-resistance of alkaline subtilisin, structural changes of two typical subtilisins, subtilisin ALP I (ALP I) and subtilisin Sendai (Sendai), were studied by means of physicochemical methods. Subtilisin NAT (NAT), which exhibits no alkaline resistance, was examined as a control. ALP I gradually lost its activity, accompanied by protein degradation, but, on the contrary, Sendai was stable under alkaline conditions. CD spectral measurements at neutral and alkaline pH indicated no apparent differences between ALP I and Sendai. A significant difference was observed on measurement of fluorescence emission spectra of the tryptophan residues of ALP I that were exposed on the enzyme surface. The fluorescence intensity of ALP I was greatly reduced under alkaline conditions; moreover, the reduction was reversed when alkaline-treated ALP I was neutralized. The fluorescence spectrum of Sendai remained unchanged. The enzymatic and optical activities of NAT were lost at high pH, indicating a lack of functional and structural stability in an alkaline environment. Judging from these results, the alkaline resistance is closely related to the surface structure of the enzyme molecule. PMID:11328588

  12. Permeability of mono- and bi-dispersed porous media

    NASA Astrophysics Data System (ADS)

    Byon, C.; Kim, S. J.

    2013-04-01

    In this study, the permeability of mono- and bi-dispersed porous media is considered. The effects of the particle size distribution and the packing structure of particles on the permeability are investigated experimentally and analytically. Both experimental and analytic results suggest that the particlesize distribution is close to the log-normal distribution, and the permeability of the mono-dispersed porous media quasi-linearly decreases as the range of the particle size distribution increases. On the other hand, the effect of packing structure of particles on the permeability is shown to be negligible.The permeability of the bidispersed porous media quasi-linearly decreases as the range of cluster size increases, and nearly independent of the particle size distribution. The present model is valid over the range of parameters typically found in heat transfer applications.

  13. Volcanic Geology of Negit Island, Mono Lake, CA

    NASA Astrophysics Data System (ADS)

    Bursik, M.; Kobs, S.; Jayko, A.

    2008-12-01

    Negit Island, located in Mono Lake, eastern California, is a dacitic cumulodome with seven distinct lava flows emanating from at least four separate vent areas. Vent areas are dominated by en echelon northeast-trending fissures, indicating strong tectonic control. Neptunian(?) pyroclastic deposits on the north end of the island indicate an explosive subaqueous eruption early in island history. Northwestern shorelands, as well as a former landbridge to the island, retain a localized cap of rotated Pleistocene lake bottom sediment blocks, suggesting that proto-Negit was similar to modern Paoha Island, a nearby young structural dome draped with rotated lake bed blocks and explosive ejecta. In analogy with Paoha, the pyroclastic ejecta and blocks may thus indicate sublacustrine block landsliding with attendant eruption as an initial magmatic-structural dome grew, on which later lava domes and flows were superposed. What may be the oldest lava flow, in the center-west, is overlain by a deep orange-red soil, and three Mono Craters tephras. The well-developed soil indicates an extended period of chemical weathering before overlying tephra deposition. The southwestern end of the island is dominated by young lava flows and a prominent dome, which are not overlain by the most recent North Mono Craters tephra of 1350 A.D., consistent with earlier work indicating that parts of the island are younger than any eruption of the Mono Craters. The history of early structural doming with little or minimal eruptive activity at both Negit and Paoha Islands may have important implications for the current episode of noneruptive unrest and doming at nearby Long Valley caldera.

  14. Modification and performance evaluation of a mono-valve engine

    NASA Astrophysics Data System (ADS)

    Behrens, Justin W.

    A four-stroke engine utilizing one tappet valve for both the intake and exhaust gas exchange processes has been built and evaluated. The engine operates under its own power, but has a reduced power capacity than the conventional 2-valve engine. The reduction in power is traced to higher than expected amounts of exhaust gases flowing back into the intake system. Design changes to the cylinder head will fix the back flow problems, but the future capacity of mono-valve engine technology cannot be estimated. The back flow of exhaust gases increases the exhaust gas recirculation (EGR) rate and deteriorates combustion. Intake pressure data shows the mono-valve engine requires an advanced intake valve closing (IVC) time to prevent back flow of charge air. A single actuation camshaft with advanced IVC was tested in the mono-valve engine, and was found to improve exhaust scavenging at TDC and nearly eliminated all charge air back flow at IVC. The optimum IVC timing is shown to be approximately 30 crank angle degrees after BDC. The mono-valve cylinder head utilizes a rotary valve positioned above the tappet valve. The open spaces inside the rotary valveand between the rotary valve and tappet valve represent a common volume that needs to be reduced in order to reduce the base EGR rate. Multiple rotary valve configurations were tested, and the size of the common volume was found to have no effect on back flow but a direct effect on the EGR rate and engine performance. The position of the rotary valve with respect to crank angle has a direct effect on the scavenging process. Optimum scavenging occurs when the intake port is opened just after TDC.

  15. Bio-inspired anti-oil-fouling chitosan-coated mesh for oil/water separation suitable for broad pH range and hyper-saline environments.

    PubMed

    Zhang, Shiyan; Lu, Fei; Tao, Lei; Liu, Na; Gao, Changrui; Feng, Lin; Wei, Yen

    2013-11-27

    Here, we report a bio-inspired chitosan (CS)-based mesh with high separation efficiency, oil-fouling repellency, and stability in a complex liquid environment. The surface of the CS coating maintains underwater superoleophobicity and low oil adhesion (<1 μN) in pure water and hyper-saline solutions, and it can keep stable special wettability in broad pH range environments after the CS mesh is fully cross-linked with glutaraldehyde and then reduced by sodium borohydride to form a stable carbon-nitrogen single bond. The separation process is solely gravity-driven, and the mesh can separate a range of different oil/water mixtures with >99% separation efficiency in hyper-saline and broad pH range conditions. We envision that such a separation method will be useful in oil spill cleanup and industrial oily wastewater treatment in extreme environments. PMID:24180691

  16. Bartonella henselae inhibits apoptosis in Mono Mac 6 cells.

    PubMed

    Kempf, Volkhard A J; Schairer, Annette; Neumann, Diana; Grassl, Guntram A; Lauber, Kirsten; Lebiedziejewski, Maria; Schaller, Martin; Kyme, Pierre; Wesselborg, Sebastian; Autenrieth, Ingo B

    2005-01-01

    Bartonella henselae causes the vasculoproliferative disorders bacillary angiomatosis and peliosis probably resulting from the release of vasculoendothelial growth factor (VEGF) from infected epithelial or monocytic host cells. Here we demonstrate that B. henselae in addition to VEGF induction was also capable of inhibiting the endogenous sucide programme of monocytic host cells. Our results show that B. henselae inhibits pyrrolidine dithiocarbamate (PDTC)-induced apoptosis in Mono Mac 6 cells. B. henselae was observed to be present in a vacuolic compartment of Mono Mac 6 cells. Direct contact of B. henselae with Mono Mac 6 cells was crucial for inhibition of apoptosis as shown by the use of a two-chamber model. Inhibition of apoptosis was paralleled by diminished caspase-3 activity which was significantly reduced in PDTC-stimulated and B. henselae-infected cells. The anti-apoptotic effect of B. henselae was accompanied by (i) the activation of the transcription factor NF-kappaB and (ii) the induction of cellular inhibitor of apoptosis proteins-1 and -2 (cIAP-1, -2). Our results suggest a new synergistic mechanism in B. henselae pathogenicity by (i) inhibition of host cell apoptosis via activation of NF-kappaB and (ii) induction of host cell VEGF secretion. PMID:15617526

  17. Age of the Mono Lake excursion and associated tephra

    NASA Astrophysics Data System (ADS)

    Benson, Larry; Liddicoat, Joseph; Smoot, Joseph; Sarna-Wojcicki, Andrei; Negrini, Robert; Lund, Steve

    2003-02-01

    The Mono Lake excursion (MLE) is an important time marker that has been found in lake and marine sediments across much of the Northern Hemisphere. Dating of this event at its type locality, the Mono Basin of California, has yielded controversial results with the most recent effort concluding that the MLE may actually be the Laschamp excursion (Earth Planet. Sci. Lett. 197 (2002) 151). We show that a volcanic tephra (Ash ♯15) that occurs near the midpoint of the MLE has a date (not corrected for reservoir effect) of 28,620±300 14C yr BP (˜32,400 GISP2 yr BP) in the Pyramid Lake Basin of Nevada. Given the location of Ash ♯15 and the duration of the MLE in the Mono Basin, the event occurred between 31,500 and 33,300 GISP2 yr BP, an age range consistent with the position and age of the uppermost of two paleointensity minima in the NAPIS-75 stack that has been associated with the MLE (Philos. Trans. R. Soc. London Ser. A 358 (2000) 1009). The lower paleointensity minimum in the NAPIS-75 stack is considered to be the Laschamp excursion (Philos. Trans. R. Soc. London Ser. A 358 (2000) 1009).

  18. Nongeocentric axial dipole field behavior during the Mono Lake excursion

    NASA Astrophysics Data System (ADS)

    Negrini, Robert M.; McCuan, Daniel T.; Horton, Robert A.; Lopez, James D.; Cassata, William S.; Channell, James E. T.; Verosub, Kenneth L.; Knott, Jeffrey R.; Coe, Robert S.; Liddicoat, Joseph C.; Lund, Steven P.; Benson, Larry V.; Sarna-Wojcicki, Andrei M.

    2014-04-01

    A new record of the Mono Lake excursion (MLE) is reported from the Summer Lake Basin of Oregon, USA. Sediment magnetic properties indicate magnetite as the magnetization carrier and imply suitability of the sediments as accurate recorders of the magnetic field including relative paleointensity (RPI) variations. The magnitudes and phases of the declination, inclination, and RPI components of the new record correlate well with other coeval but lower resolution records from western North America including records from the Wilson Creek Formation exposed around Mono Lake. The virtual geomagnetic pole (VGP) path of the new record is similar to that from another high-resolution record of the MLE from Ocean Drilling Program (ODP) Site 919 in the Irminger Basin between Iceland and Greenland but different from the VGP path for the Laschamp excursion (LE), including that found lower in the ODP-919 core. Thus, the prominent excursion recorded at Mono Lake, California, is not the LE but rather one that is several thousands of years younger. The MLE VGP path contains clusters, the locations of which coincide with nonaxial dipole features found in the Holocene geomagnetic field. The clusters are occupied in the same time progression by VGPs from Summer Lake and the Irminger Basin, but the phase of occupation is offset, a behavior that suggests time-transgressive decay and return of the principal field components at the beginning and end of the MLE, respectively, leaving the nonaxial dipole features associated with the clusters dominant during the excursion.

  19. Age of the Mono Lake excursion and associated tephra

    USGS Publications Warehouse

    Benson, L.; Liddicoat, J.; Smoot, J.; Sarna-Wojcicki, A.; Negrini, R.; Lund, S.

    2003-01-01

    The Mono Lake excursion (MLE) is an important time marker that has been found in lake and marine sediments across much of the Northern Hemisphere. Dating of this event at its type locality, the Mono Basin of California, has yielded controversial results with the most recent effort concluding that the MLE may actually be the Laschamp excursion (Earth Planet. Sci. Lett. 197 (2002) 151). We show that a volcanic tephra (Ash #15) that occurs near the midpoint of the MLE has a date (not corrected for reservoir effect) of 28,620 ?? 300 14C yr BP (??? 32,400 GISP2 yr BP) in the Pyramid Lake Basin of Nevada. Given the location of Ash #15 and the duration of the MLE in the Mono Basin, the event occurred between 31,500 and 33,300 GISP2 yr BP, an age range consistent with the position and age of the uppermost of two paleointensity minima in the NAPIS-75 stack that has been associated with the MLE (Philos. Trans. R. Soc. London Ser. A 358 (2000) 1009). The lower paleointensity minimum in the NAPIS-75 stack is considered to be the Laschamp excursion (Philos. Trans. R. Soc. London Ser. A 358 (2000) 1009).

  20. Bacterial oxidation of methyl bromide in Mono Lake, California

    USGS Publications Warehouse

    Connell, T.L.; Joye, S.B.; Miller, L.G.; Oremland, R.S.

    1997-01-01

    The oxidation of methyl bromide (MeBr) in the water column of Mono Lake, CA, was studied by measuring the formation of H14CO3 from [14C]MeBr. Potential oxidation was detected throughout the water column, with highest rates occurring in the epilimnion (5-12 m depth). The oxidation of MeBr was eliminated by filter-sterilization, thereby demonstrating the involvement of bacteria. Vertical profiles of MeBr activity differed from those obtained for nitrification and methane oxidation, indicating that MeBr oxidation is not simply a co-oxidation process by either nitrifiers or methanotrophs. Furthermore, specific inhibitors of methane oxidation and/or nitrification (e.g., methyl fluoride, acetylene, allyl sulfide) had no effect upon the rate of MeBr oxidation in live samples. Of a variety of potential electron donors added to Mono Lake water, only trimethylamine resulted in the stimulation of MeBr oxidation. Cumulatively, these results suggest that the oxidation of MeBr in Mono Lake waters is attributable to trimethylamine-degrading methylotrophs. Neither methyl chloride nor methanol inhibited the oxidation of [14C]MeBr in live samples, indicating that these bacteria directly oxidized MeBr rather than the products of MeBr nucleophilic substitution reactions.

  1. Mono- versus polydrug abuse patterns among publicly funded clients.

    PubMed

    Kedia, Satish; Sell, Marie A; Relyea, George

    2007-01-01

    To examine patterns of mono- versus polydrug abuse, data were obtained from intake records of 69,891 admissions to publicly funded treatment programs in Tennessee between 1998 and 2004. While descriptive statistics were employed to report frequency and patterns of mono- and polydrug abuse by demographic variables and by study years, bivariate logistic regression was applied to assess the probability of being a mono- or polydrug abuser for a number of demographic variables. The researchers found that during the study period 51.3% of admissions reported monodrug abuse and 48.7% reported polydrug abuse. Alcohol, cocaine, and marijuana were the most commonly abused substances, both alone and in combination. Odds ratio favored polydrug abuse for all but one drug category-other drugs. Gender did not affect drug abuse patterns; however, admissions for African Americans and those living in urban areas exhibited higher probabilities of polydrug abuse. Age group also appeared to affect drug abuse patterns, with higher odds of monodrug abuse among minors and adults over 45 years old. The discernable prevalence of polydrug abuse suggests a need for developing effective prevention strategies and treatment plans specific to polydrug abuse. PMID:17996066

  2. Alkaline sorbent injection for mercury control

    DOEpatents

    Madden, Deborah A.; Holmes, Michael J.

    2002-01-01

    A mercury removal system for removing mercury from combustion flue gases is provided in which alkaline sorbents at generally extremely low stoichiometric molar ratios of alkaline earth or an alkali metal to sulfur of less than 1.0 are injected into a power plant system at one or more locations to remove at least between about 40% and 60% of the mercury content from combustion flue gases. Small amounts of alkaline sorbents are injected into the flue gas stream at a relatively low rate. A particulate filter is used to remove mercury-containing particles downstream of each injection point used in the power plant system.

  3. Alkaline sorbent injection for mercury control

    DOEpatents

    Madden, Deborah A.; Holmes, Michael J.

    2003-01-01

    A mercury removal system for removing mercury from combustion flue gases is provided in which alkaline sorbents at generally extremely low stoichiometric molar ratios of alkaline earth or an alkali metal to sulfur of less than 1.0 are injected into a power plant system at one or more locations to remove at least between about 40% and 60% of the mercury content from combustion flue gases. Small amounts of alkaline sorbents are injected into the flue gas stream at a relatively low rate. A particulate filter is used to remove mercury-containing particles downstream of each injection point used in the power plant system.

  4. Inorganic-organic separators for alkaline batteries

    NASA Technical Reports Server (NTRS)

    Sheibley, D. W. (Inventor)

    1978-01-01

    A flexible separator is reported for use between the electrodes of Ni-Cd and Ni-Zn batteries using alkaline electrolytes. The separator was made by coating a porous substrate with a battery separator composition. The coating material included a rubber-based resin copolymer, a plasticizer and inorganic and organic fillers which comprised 55% by volume or less of the coating as finally dried. One or more of the filler materials, whether organic or inorganic, is preferably active with the alkaline electrolyte to produce pores in the separator coating. The plasticizer was an organic material which is hydrolyzed by the alkaline electrolyte to improve conductivity of the separator coating.

  5. Process for extracting technetium from alkaline solutions

    DOEpatents

    Moyer, Bruce A.; Sachleben, Richard A.; Bonnesen, Peter V.

    1995-01-01

    A process for extracting technetium values from an aqueous alkaline solution containing at least one alkali metal hydroxide and at least one alkali metal nitrate, the at least one alkali metal nitrate having a concentration of from about 0.1 to 6 molar. The solution is contacted with a solvent consisting of a crown ether in a diluent for a period of time sufficient to selectively extract the technetium values from the aqueous alkaline solution. The solvent containing the technetium values is separated from the aqueous alkaline solution and the technetium values are stripped from the solvent.

  6. Composite seal reduces alkaline battery leakage

    NASA Technical Reports Server (NTRS)

    Clatterbuck, C. H.; Plitt, K. F.

    1965-01-01

    Composite seal consisting of rubber or plastic washers and a metal washer reduces alkaline battery leakage. Adhesive is applied to each washer interface, and the washers are held together mechanically.

  7. Holocene Depositional History of Shad Pond, a Hypersaline Coastal Lagoon, Eleuthera, Bahamas and Its Influence on Lucayan Occupation

    NASA Astrophysics Data System (ADS)

    Boush, L. E.; Fentress, S.; Conroy, M.; Cook, A.; Miseridina, D.; Buynevich, I. V.; Myrbo, A.; Brown, E. T.; Berman, M.; Gnivecki, P.; Kjellmark, E.; Savarese, M.; Brady, K.

    2013-12-01

    Shad Pond, an enclosed hypersaline lagoon on the southeastern tip of Eleuthera, Bahamas reveals a ~5000-year record of hurricane activity, as well as sea-level and climate change history. Three sediment cores recovered 1.04-2.54 m of sediment over bedrock along a transect perpendicular to shoreline. Sediment composition and grain size, loss on ignition, X-ray fluorescence (XRF) measurements of the cores along with dune transects and ground-penetrating radar (GPR) profiles adjacent to the lake provide a comprehensive dataset to interpret the history of this coastal basin. The sedimentary sequence was composed of alternating lithofacies that included microbial mats, sand, and peat. Laminated mats often alternated with sandy layers in thin to medium-bedded units. Two peat layers were found in the basal part of the shore-distal core (Site 1) between 1.82-2.40 m and 2.53-2.54 m and were separated by a 13-cm-thick gray mud layer. In general, organic matter and carbonate content tracked granulometry and composition in all cores. High-resolution XRF scans of Ca and Sr at Site 1 show elevated levels ~3,700 cal yBP, which correlate with the top of the peat layer, but these elemental concentrations vary at Site 3. XRF measurements of Fe indicate a dust flux that has been recorded regionally throughout the Caribbean. Dune transects and GPR profiles indicate a phased history of the pond, beginning with initial stages as an open lagoon dominated by red mangrove, with black mangrove and buttonwood also present. The lake likely closed at approximately 3,700 cal yBP indicated by the transition between the upper peat and microbial mat layers. This could have been due to increased storm events in a regime of rising sea level. Aeolian aggradation continued to heighten the barrier between the bedrock headlands to its present position. Hurricane overwash deposits punctuated the algal mat accumulation throughout this time period. Present-day hypersaline conditions sustain algal mats

  8. Multiple evidence for methylotrophic methanogenesis as the dominant methanogenic pathway in hypersaline sediments from the Orca Basin, Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Zhuang, Guang-Chao; Elling, Felix J.; Nigro, Lisa M.; Samarkin, Vladimir; Joye, Samantha B.; Teske, Andreas; Hinrichs, Kai-Uwe

    2016-08-01

    Among the most extreme habitats on Earth, dark, deep, anoxic brines host unique microbial ecosystems that remain largely unexplored. As the terminal step of anaerobic degradation of organic matter, methanogenesis is a potentially significant but poorly constrained process in deep-sea hypersaline environments. We combined biogeochemical and phylogenetic analyses with incubation experiments to unravel the origin of methane in the hypersaline sediments of Orca Basin in the northern Gulf of Mexico. Substantial concentrations of methane, up to 3.4 mM, coexisted with high concentrations of sulfate from 16 to 43 mM in two sediment cores retrieved from the northern and southern parts of Orca Basin. The strong depletion of 13C in methane (-77‰ to -89‰) points towards a biological source. While low concentrations of competitive substrates limited the significance of hydrogenotrophic and acetoclastic methanogenesis, the presence of non-competitive methylated substrates (methanol, trimethylamine, dimethyl sulfide, dimethylsulfoniopropionate) supported the potential for methane generation through methylotrophic methanogenesis. Thermodynamic calculations demonstrated that hydrogenotrophic and acetoclastic methanogenesis were unlikely to occur under in situ conditions, while methylotrophic methanogenesis from a variety of substrates was highly favorable. Likewise, carbon isotope relationships between methylated substrates and methane suggested methylotrophic methanogenesis was the major source of methane. Stable and radio-isotope tracer experiments with 13C-labeled bicarbonate, acetate and methanol and 14C-labeled methylamine indicated that methylotrophic methanogenesis was the predominant methanogenic pathway. Based on 16S rRNA gene sequences, halophilic methylotrophic methanogens related to the genus Methanohalophilus dominated the benthic archaeal community in the northern basin and also occurred in the southern basin. High abundances of methanogen lipid biomarkers such as

  9. Technetium recovery from high alkaline solution

    DOEpatents

    Nash, Charles A.

    2016-07-12

    Disclosed are methods for recovering technetium from a highly alkaline solution. The highly alkaline solution can be a liquid waste solution from a nuclear waste processing system. Methods can include combining the solution with a reductant capable of reducing technetium at the high pH of the solution and adding to or forming in the solution an adsorbent capable of adsorbing the precipitated technetium at the high pH of the solution.

  10. Alkaline tolerant dextranase from streptomyces anulatus

    DOEpatents

    Decker, Stephen R.; Adney, William S.; Vinzant, Todd B.; Himmel, Michael E.

    2003-01-01

    A process for production of an alkaline tolerant dextranase enzyme comprises culturing a dextran-producing microorganism Streptomyces anulatus having accession no. ATCC PTA-3866 to produce an alkaline tolerant dextranase, Dex 1 wherein the protein in said enzyme is characterized by a MW of 63.3 kDa and Dex 2 wherein its protein is characterized by a MW of 81.8 kDa.

  11. Evaluation of the alkaline electrolysis of zinc

    SciTech Connect

    Meisenhelder, J.H.; Brown, A.P.; Loutfy, R.O.; Yao, N.P.

    1981-05-01

    The alkaline leach and electrolysis process for zinc production is compared to the conventional acid-sulfate process in terms of both energy saving and technical merit. In addition, the potential for industrial application of the alkaline process is discussed on the basis of present market conditions, possible future zinc market scenarios, and the probability of increased secondary zinc recovery. In primary zinc production, the energy-saving potential for the alkaline process was estimated to be greater than 10%, even when significantly larger electrolysis current densities than those required for the sulfate process are used. The principal technical advantages of the alkaline process are that it can handle low-grade, high-iron-content or oxidized ores (like most of those found in the US) in a more cost- and energy-efficient manner than can the sulfate process. Additionally, in the electrowinning operation, the alkaline process should be technically superior because a dendritic or sponge deposit is formed that is amenable to automated collection without interruption of the electrolysis. Also, use of the higher current densities would result in significant capital cost reductions. Alkaline-based electrolytic recovery processes were considered for the recycling of zinc from smelter baghouse dusts and from the potential source of nickel/zinc electric-vehicle batteries. In all comparisons, an alkaline process was shown to be technically superior and, particularly for the baghouse dusts, energetically and economically superior to alternatively proposed recovery methods based on sulfate electrolysis. It is concluded that the alkaline zinc method is an important alternative technology to the conventional acid zinc process. (WHK)

  12. Alkaline Water and Longevity: A Murine Study

    PubMed Central

    Magro, Massimiliano; Corain, Livio; Ferro, Silvia; Baratella, Davide; Bonaiuto, Emanuela; Terzo, Milo; Corraducci, Vittorino; Salmaso, Luigi; Vianello, Fabio

    2016-01-01

    The biological effect of alkaline water consumption is object of controversy. The present paper presents a 3-year survival study on a population of 150 mice, and the data were analyzed with accelerated failure time (AFT) model. Starting from the second year of life, nonparametric survival plots suggest that mice watered with alkaline water showed a better survival than control mice. Interestingly, statistical analysis revealed that alkaline water provides higher longevity in terms of “deceleration aging factor” as it increases the survival functions when compared with control group; namely, animals belonging to the population treated with alkaline water resulted in a longer lifespan. Histological examination of mice kidneys, intestine, heart, liver, and brain revealed that no significant differences emerged among the three groups indicating that no specific pathology resulted correlated with the consumption of alkaline water. These results provide an informative and quantitative summary of survival data as a function of watering with alkaline water of long-lived mouse models. PMID:27340414

  13. Performed surfactant-optimized aqueous alkaline flood

    SciTech Connect

    Thigpen, D.R.; Lawson, J.B.; Nelson, R.C.

    1991-11-26

    This paper describes improvement in a process for recovering oil from an acidic oil reservoir by injecting an aqueous alkaline solution comprising water, sodium chloride, and alkaline material for reacting with the reservoir oil forming a petroleum acid soap to form an in-situ surfactant system. The improvement comprises: selecting a preformed cosurfactant which is soluble in both the aqueous solution and the reservoir oil and has a solubility ratio which is grater than the solubility ratio of the petroleum acid soap where the solubility ratio is the ratio of solubility in the aqueous alkaline solution to the solubility in the reservoir oil; combining with the alkaline solution an amount of the preformed cosurfactant which will result in the in-situ surfacant system having a salinity about equal to a salinity which results in minimal interfacial tension between the oil in the reservoir and the in-situ surfactant system at reservoir temperature, wherein the amount of the preformed cosurfactant is about 0.3 percent by weight in the aqueous alkaline solution; and injecting the cosurfactant-aqueous alkaline solution mixture into the reservoir to displace oil toward a fluid production location.

  14. Oxidation of ammonia and methane in an alkaline, saline lake

    USGS Publications Warehouse

    Joye, S.B.; Connell, T.L.; Miller, L.G.; Oremland, R.S.; Jellison, R.S.

    1999-01-01

    The oxidation of ammonia (NH3) and methane (CH4) was investigated in an alkaline saline lake, Mono Lake, California (U.S.A.). Ammonia oxidation was examined in April and July 1995 by comparing dark 14CO2 fixation rates in the presence or absence of methyl fluoride (MeF), an inhibitor of NH3 oxidation. Ammonia oxidizer-mediated dark 14CO2 fixation rates were similar in surface (5-7 m) and oxycline (11-15 m) waters, ranging between 70-340 and 89-186 nM d-1, respectively, or 1-7% of primary production by phytoplankton. Ammonia oxidation rates ranged between 580-2,830 nM d-1 in surface waters and 732-1,548 nM d-1 in oxycline waters. Methane oxidation was examined using a 14CH4 tracer technique in July 1994, April 1995, and July 1995. Methane oxidation rates were consistently higher in July, and rates in oxycline and anaerobic bottom waters (0.5-37 and 7-48 nM d-1, respectively) were 10-fold higher than those in aerobic surface waters (0.04-3.8 nM d-1). The majority of CH4 oxidation, in terms of integrated activity, occurred within anoxic bottom waters. Water column oxidation reduced the potential lake-atmosphere CH4 flux by a factor of two to three. Measured oxidation rates and water column concentrations were used to estimate the biological turnover times of NH3 and CH4. The NH3 pool turns over rapidly, on time scales of 0.8 d in surface waters and 10 d within the oxycline, while CH4 is cycled on 103-d time scales in surface waters and 102-d time scales within oxycline and bottom waters. Our data suggest an important role for NH3 oxidation in alkaline, saline lakes since the process converts volatile NH3 to soluble NO2-, thereby reducing loss via lake-atmosphere exchange and maintaining nitrogen in a form that is readily available to phytoplankton.

  15. Biogeochemistry of natural gases in three alkaline, permanently stratified (meromictic) lakes

    SciTech Connect

    Oremland, R.S.; Miller, L.G. )

    1993-01-01

    Methane and associated light hydrocarbons are present as dissolved gases in the water columns of three alkaline, permanently stratified (meromictic) lakes: Big Soda Lake (Nevada), Mono Lake (California), and Soap Lake (Washington). Methane originates in the bottom sediments, but higher gaseous hydrocarbons (that is, gaseous hydrocarbons of higher molecular weight) have either microbial or thermal sources in the different lakes. Stable isotopic composition, hydrocarbon indices, radiocarbon dating, abundance-versus-depth profiles, and biological experiments indicate that methane is formed in the sediments by microbial processes. Methanogenesis and sulfate-reduction have much higher activity in the shallow littoral sediments than in the colder, more saline pelagic sediments of all three lakes. Methane-rich gas seeps are common in Mono Lake and emanate from a natural-gas deposit underlying the current lakebed. Seeps do not occur in either Big Soda Lake or Soap Lake. Ethane and higher alkanes are present in Big Soda Lake and Mono Lake, but are not present in significant quantities in Soap Lake. It is not clear if the presence of these higher alkanes is a consequence of biological activity, a result of mixing with thermogenic gases, or a combination of both factors. These results indicate the potential complexity and diversity encountered in studying light-hydrocarbon biogeochemistry in thermally and microbially active systems. Hence, in the case of methane, detailed multidisciplinary studies are often needed to determine its origin. For ethane and higher alkanes, there is currently a paucity of basic scientific information to allow for unequivocal identification of microbial and thermogenetic sources. 61 refs., 12 figs., 6 tabs.

  16. 21 CFR 864.7660 - Leukocyte alkaline phosphatase test.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Leukocyte alkaline phosphatase test. 864.7660... Leukocyte alkaline phosphatase test. (a) Identification. A leukocyte alkaline phosphatase test is a device used to identify the enzyme leukocyte alkaline phosphatase in neutrophilic granulocytes...

  17. 21 CFR 864.7660 - Leukocyte alkaline phosphatase test.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Leukocyte alkaline phosphatase test. 864.7660... Leukocyte alkaline phosphatase test. (a) Identification. A leukocyte alkaline phosphatase test is a device used to identify the enzyme leukocyte alkaline phosphatase in neutrophilic granulocytes...

  18. Inter-comparison of the potentially active prokaryotic communities in the halocline sediments of Mediterranean deep-sea hypersaline basins.

    PubMed

    Kormas, Konstantinos A; Pachiadaki, Maria G; Karayanni, Hera; Leadbetter, Edward R; Bernhard, Joan M; Edgcomb, Virginia P

    2015-09-01

    The sediment microbiota of the Mediterranean deep-sea anoxic hypersaline basins (DHABs) are understudied relative to communities in the brines and halocline waters. In this study, the active fraction of the prokaryotic community in the halocline sediments of L' Atalante, Urania, and Discovery DHABs was investigated based on extracted total RNA and 454 pyrosequencing of the 16S rRNA gene. Bacterial and archaeal communities were different in the sediments underlying the halocline waters of the three habitats, reflecting the unique chemical settings of each basin. The relative abundance of unique operational taxonomic units (OTUs) was also different between deep-sea control sediments and sediments underlying DHAB haloclines, suggesting adaptation to the steep DHAB chemical gradients. Only a few OTUs were affiliated to known bacterial halophilic and/or anaerobic groups. Many OTUs, including some of the dominant ones, were related to aerobic taxa. Archaea were detected only in few halocline samples, with lower OTU richness relative to Bacteria, and were dominated by taxa associated with methane cycling. This study suggests that, while metabolically active prokaryotic communities appear to be present in sediments underlying the three DHABs investigated, their diversity and activity are likely to be more reduced in sediments underlying the brines. PMID:26174531

  19. Halanaeroarchaeum sulfurireducens gen. nov., sp. nov., the first obligately anaerobic sulfur-respiring haloarchaeon, isolated from a hypersaline lake.

    PubMed

    Sorokin, Dimitry Y; Kublanov, Ilya V; Yakimov, Mikhail M; Rijpstra, W Irene C; Sinninghe Damsté, Jaap S

    2016-06-01

    Anaerobic enrichments with acetate as electron donor and carbon source, and elemental sulfur as electron acceptor at 4 M NaCl using anaerobic sediments and brines from several hypersaline lakes in Kulunda Steppe (Altai, Russia) resulted in isolation in pure culture of four strains of obligately anaerobic haloarchae growing exclusively by sulfur respiration. Such metabolism has not yet been demonstrated in any known species of Halobacteria, and in the whole archaeal kingdom, acetate oxidation with sulfur as acceptor was not previously demonstrated. The four isolates had nearly identical 16S rRNA gene sequences and formed a novel genus-level branch within the family Halobacteriaceae. The strains had a restricted substrate range limited to acetate and pyruvate as electron donors and elemental sulfur as electron acceptor. In contrast to aerobic haloarchaea, the biomass of anaerobic isolates completely lacked the typical red pigments. Growth with acetate+sulfur was observed between 3-5 M NaCl and at a pH range from 6.7 to 8.0. The membrane core lipids were dominated by archaeols. On the basis of distinct physiological and phylogenetic data, the sulfur-respiring isolates represent a novel species of a new genus in the family Halobacteriaceae, for which the name Halanaeroarchaeaum sulfurireducens gen. nov., sp. nov. is proposed. The type strain of the type species is HSR2T (=JCM 30661T=UNIQEM U935T). PMID:27031647

  20. Phylogenetic Analysis of a Microbialite-Forming Microbial Mat from a Hypersaline Lake of the Kiritimati Atoll, Central Pacific

    PubMed Central

    Schneider, Dominik; Arp, Gernot; Reimer, Andreas; Reitner, Joachim; Daniel, Rolf

    2013-01-01

    On the Kiritimati atoll, several lakes exhibit microbial mat-formation under different hydrochemical conditions. Some of these lakes trigger microbialite formation such as Lake 21, which is an evaporitic, hypersaline lake (salinity of approximately 170‰). Lake 21 is completely covered with a thick multilayered microbial mat. This mat is associated with the formation of decimeter-thick highly porous microbialites, which are composed of aragonite and gypsum crystals. We assessed the bacterial and archaeal community composition and its alteration along the vertical stratification by large-scale analysis of 16S rRNA gene sequences of the nine different mat layers. The surface layers are dominated by aerobic, phototrophic, and halotolerant microbes. The bacterial community of these layers harbored Cyanobacteria (Halothece cluster), which were accompanied with known phototrophic members of the Bacteroidetes and Alphaproteobacteria. In deeper anaerobic layers more diverse communities than in the upper layers were present. The deeper layers were dominated by Spirochaetes, sulfate-reducing bacteria (Deltaproteobacteria), Chloroflexi (Anaerolineae and Caldilineae), purple non-sulfur bacteria (Alphaproteobacteria), purple sulfur bacteria (Chromatiales), anaerobic Bacteroidetes (Marinilabiacae), Nitrospirae (OPB95), Planctomycetes and several candidate divisions. The archaeal community, including numerous uncultured taxonomic lineages, generally changed from Euryarchaeota (mainly Halobacteria and Thermoplasmata) to uncultured members of the Thaumarchaeota (mainly Marine Benthic Group B) with increasing depth. PMID:23762495

  1. Primary production and respiration of hypersaline microbial mats as a response for high and low CO2 availability

    NASA Astrophysics Data System (ADS)

    Bento, L.; Enrich-Prast, A.; Nielsen, L. P.

    2012-09-01

    Here we report a time series of experiments performed in a microcosm to test the response of hypersaline microbial mats to diverse atmospheric CO2 conditions. Different from most part of the literature, our study used a sample chamber were carbon dioxide concentration was controlled. Our aim was to test the effect of different atmospheric CO2 conditions in benthic gross and net primary production, and respiration. This study showed for the first time to our knowledge absolute carbon limitation in a microbial mat. Oxygen concentration profile varied from a flattened shape to almost linear when atmospheric CO2 at the chamber reached 0 ppm, with NPP reaching 0 nmol cm-3 s-1 throughout most part of the profile. In this conditions sediment community respiration represented 100% of GPP. Extreme close coupling between primary production and respiration in microbial mats can be even self-sustainable in environments with temporally no atmospheric CO2 available. When submitted to even high CO2 concentrations (550 ppm), our sample showed a characteristic shape that indicate limitation composed by a more rectilinear oxygen profile, and NPP peaks mainly restricted to deeper layers. Therefore, we suggest that phototrophic communities in aquatic shallow ecosystems can be carbon limited. This limitation could be common especially in ecosystems submitted to variable water depth conditions, like coastal lagoons and intertidal sediments.

  2. Richness and diversity of helminth species in eels from a hypersaline coastal lagoon, Mar Menor, south-east Spain.

    PubMed

    Mayo-Hernández, E; Peñalver, J; García-Ayala, A; Serrano, E; Muñoz, P; Ruiz de Ybáñez, R

    2015-05-01

    The composition and diversity of parasite communities and intestinal components, as well as infra-community structure, were assessed in eels Anguilla anguilla, from Mar Menor, a permanent Mediterranean hypersaline coastal lagoon. Data were used to determine whether this helminth community differs in composition and structure from that of eels in lagoons with lower salinity regimes and higher freshwater inputs. A total prevalence of 93% was detected. Specifically, parasites were identified as Deropristis inflata, Bucephalus anguillae, Contracaecum sp., Anguillicoloides crassus and two plerocercoid larvae belonging to the order Proteocephalidae, the marine species representing 91% of the isolated helminths. In the total community, digenetic trematodes were the dominant group of helminths, and D. inflata, an eel specialist, dominated both the component community and the infra-community. Richness and diversity were low but similar to those reported in other saline lagoons, and maximum species per eel did not exceed four. At the infra-community level, higher abundance than in other brackish or marine Mediterranean environments was detected. The findings provide further evidence of the similarity in composition and structure of helminth communities in eels from various Mediterranean coastal lagoons. Moreover, salinity-dependent specificities are well supported and reflect the life history of individual eels. PMID:24685015

  3. The effects of salinity on nitrification using halophilic nitrifiers in a Sequencing Batch Reactor treating hypersaline wastewater

    PubMed Central

    Cui, You-Wei; Zhang, Hong-Yu; Ding, Jie-Ran; Peng, Yong-Zhen

    2016-01-01

    With annual increases in the generation and use of saline wastewater, the need to avoid environmental problems such as eutrophication is critical. A previous study identified ways to start up a halophilic sludge domesticated from estuarine sediments to remove nitrogen from wastewater with a salinity of 30 g/L. This investigation expands that work to explore the impact of salinity on nitrogen removal. This study demonstrated that the mixed halophilic consortia removed nitrogen from wastewater with a salinity of 30–85 g/L. A kinetic analysis showed that halophilic nitrifiers selected based on hypersalinity were characterized by low Ks, μmax and specific ammonium oxidization rates. This explains the decrease in ammonium removal efficiency in the high salinity operational phases. Salinity inhibited ammonia oxidizing bacteria (AOB) activity, as well as the number of dominant AOB, but did not significantly affect the AOB dominant species. Three most dominant AOB lineages in the halophilic sludge were Nitrosomonas marina, Nitrosomonas europaea, and Nitrosococcus mobilis. Nitrosomonas europaea and Nitrosococcus mobilis were mainly affected by salinity, while nitrite accumulation and ammonia loading played the key role in determining the abundance of Nitrosococcus mobilis and Nitrosococcus europaea. The study contributes insights about shifts in halophilic nitrifying bacterial populations. PMID:27109617

  4. The effects of salinity on nitrification using halophilic nitrifiers in a Sequencing Batch Reactor treating hypersaline wastewater.

    PubMed

    Cui, You-Wei; Zhang, Hong-Yu; Ding, Jie-Ran; Peng, Yong-Zhen

    2016-01-01

    With annual increases in the generation and use of saline wastewater, the need to avoid environmental problems such as eutrophication is critical. A previous study identified ways to start up a halophilic sludge domesticated from estuarine sediments to remove nitrogen from wastewater with a salinity of 30 g/L. This investigation expands that work to explore the impact of salinity on nitrogen removal. This study demonstrated that the mixed halophilic consortia removed nitrogen from wastewater with a salinity of 30-85 g/L. A kinetic analysis showed that halophilic nitrifiers selected based on hypersalinity were characterized by low Ks, μmax and specific ammonium oxidization rates. This explains the decrease in ammonium removal efficiency in the high salinity operational phases. Salinity inhibited ammonia oxidizing bacteria (AOB) activity, as well as the number of dominant AOB, but did not significantly affect the AOB dominant species. Three most dominant AOB lineages in the halophilic sludge were Nitrosomonas marina, Nitrosomonas europaea, and Nitrosococcus mobilis. Nitrosomonas europaea and Nitrosococcus mobilis were mainly affected by salinity, while nitrite accumulation and ammonia loading played the key role in determining the abundance of Nitrosococcus mobilis and Nitrosococcus europaea. The study contributes insights about shifts in halophilic nitrifying bacterial populations. PMID:27109617

  5. Comparison of bacterial biodiversity and enzyme production in three hypersaline lakes; urmia, howz-soltan and aran-bidgol.

    PubMed

    Babavalian, Hamid; Amoozegar, Mohammad Ali; Zahraei, Shirin; Rohban, Rokhsareh; Shakeri, Fatemeh; Moghaddam, Mehrdad Moosazadeh

    2014-12-01

    This research is a comparative study on the diversity of halophilic bacteria with hydrolytic activities in three significant hypersaline lakes; Urmia in the northwest and Howz-Soltan and Aran-Bidgol in the central desert in Iran. Isolated strains from these saline lakes were found to be halotolerant, moderately and extremely halophilic bacteria. The bacteria in each saline lake were able to produce different hydrolytic enzymes including amylase, protease, lipase, DNase, inulinase, xylanase, carboxy methyl cellulase, pectinase and pullulanase. 188, 302, 91 halophilic strains were isolated from Urmia Lake, Howz-Soltan and Aran-Bidgol playa, respectively. The numbers of Gram-positive strains were more than Gram-negatives, and among Gram-positive bacteria; spore-forming bacilli were most abundant. Due to the unique physico-chemical conditions of the lake environments, the hydrolytic activities of isolated strains were significantly different. For instance, isolated strains from Howz-Soltan playa did not produce pectinase, DNase, amylase, lipase and inulinase, while the isolates from Aran-Bidgol playa had a great ability to produce pectinase and DNase. The strains from Urmia Lake were also good producers of DNase but failed to show any chitinase activity. The diversity of halophilic bacteria from the mentioned three saline lakes was also determined using PCR-amplified 16S rRNA followed by phylogenetic analysis of the partial 16S rRNA sequences. PMID:25320444

  6. Vertical physico-chemical gradients with distinct microbial communities in the hypersaline and heliothermal Lake Ursu (Sovata, Romania).

    PubMed

    Máthé, István; Borsodi, Andrea K; Tóth, Erika M; Felföldi, Tamás; Jurecska, Laura; Krett, Gergely; Kelemen, Zsolt; Elekes, Erzsébet; Barkács, Katalin; Márialigeti, Károly

    2014-05-01

    The effect of vertical physico-chemical stratification on the planktonic microbial community composition of the deep, hypersaline and heliothermal Lake Ursu (Sovata, Romania) was examined in this study. On site and laboratory measurements were performed to determine the physical and chemical variables of the lake water, and culture-based and cultivation-independent techniques were applied to identify the members of microbial communities. The surface of the lake was characterized by a low salinity water layer while the deepest region was extremely saline (up to 300 g/L salinity). Many parameters (e.g. photosynthetically active radiation, dissolved oxygen concentration, pH, redox potential) changed dramatically from 2 to 4 m below the water surface in conjunction with the increasing salinity values. The water temperature reached a maximum at this depth. At around 3 m depth, there was a water layer with high (bacterio) chlorophyll content dominated by Prosthecochloris vibrioformis, a phototrophic green sulfur bacterium. Characteristic microbial communities with various prokaryotic taxa were identified along the different environmental parameters present in the different water layers. Some of these bacteria were known to be heterotrophic and therefore may be involved in the decomposition of lake organic material (e.g. Halomonas, Idiomarina and Pseudoalteromonas) while others in the transformation of sulfur compounds (e.g. Prosthecochloris). Eukaryotic microorganisms identified by molecular methods in the lake water belonged to genera of green algae (Mantionella and Picochlorum), and were restricted mainly to the upper layers. PMID:24531691

  7. Salt-Responsive Polysulfabetaines from Acrylate and Acrylamide Precursors: Robust Stabilization of Metal Nanoparticles in Hyposalinity and Hypersalinity.

    PubMed

    Vasantha, Vivek Arjunan; Junhui, Chen; Ying, Tay Boon; Parthiban, Anbanandam

    2015-10-13

    Metal nanoparticles (MNps) tend to be influenced by environmental factors such as pH, ionic strength, and temperature, thereby leading to aggregation. Forming stable aqueous dispersions could be one way of addressing the environmental toxicity of MNps. In contrast to the electrolyte-induced aggregation of MNps, novel zwitterionic sulfabetaine polymers reported here act as stabilizers of MNps even under high salinity. Polysulfabetaines exhibited unique solubility and swelling tendencies in brine and deionized water, respectively. The polysulfabetaines derived from methacrylate (PSBMA) and methacrylamide (PSBMAm) also showed reversible salt-responsive and thermoresponsive behaviors as confirmed by cloud-point titration, transmittance, and dynamic light scattering studies. The brine soluble nature was explored for its ability to be used as a capping agents to form metal nanoparticles using formic acid as a reducing agent. Thus, silver and noble metal (gold and palladium) nanoparticles were synthesized. The nanoparticles formed were characterized by UV-vis, XRD, TEM, EDX, and DLS studies. The size of the nanoparticles remained more or less the same even after 2 months of storage in 2 M sodium chloride solution under ambient conditions and also at elevated temperatures as confirmed by light-scattering measurements. The tunable, stimuli-responsive polysulfabetaine-capped stable MNp formed under low (hyposalinity) and hypersalinity could find potential applications in a variety of areas. PMID:26394088

  8. Probing Saltern Brines with an Oxygen Electrode: What Can We Learn about the Community Metabolism in Hypersaline Systems?

    PubMed

    Oren, Aharon

    2016-01-01

    We have explored the use of optical oxygen electrodes to study oxygenic photosynthesis and heterotrophic activities in crystallizer brines of the salterns in Eilat, Israel. Monitoring oxygen uptake rates in the dark enables the identification of organic substrates that are preferentially used by the community. Addition of glycerol (the osmotic solute synthesized by Dunaliella) or dihydroxyacetone (produced from glycerol by Salinibacter) enhanced respiration rates. Pyruvate, produced from glycerol or from some sugars by certain halophilic Archaea also stimulated community respiration. Fumarate had a sparing effect on respiration, possibly as many halophilic Archaea can use fumarate as a terminal electron acceptor in respiration. Calculating the photosynthetic activity of Dunaliella by monitoring oxygen concentration changes during light/dark incubations is not straightforward as light also affects respiration of some halophilic Archaea and Bacteria due to action of light-driven proton pumps. When illuminated, community respiration of brine samples in which oxygenic photosynthesis was inhibited by DCMU decreased by ~40%. This effect was interpreted as the result of competition between two energy yielding systems: the bacteriorhodopsin proton pump and the respiratory chain of the prokaryotes. These findings have important implications for the interpretation of other published data on photosynthetic and respiratory activities in hypersaline environments. PMID:27338478

  9. Use of 13C-Labeled Substrates to Determine Relative Methane Production Rates in Hypersaline Microbial Communities

    NASA Astrophysics Data System (ADS)

    Kelley, C. A.; Bebout, B.; Chanton, J.

    2015-12-01

    Rates and pathways of methane production were determined from photosynthetic soft microbial mats and gypsum-encrusted endoevaporites collected in hypersaline environments from California, Mexico and Chile, as well as an organic-rich mud from a pond in the El Tatio volcanic fields, Chile. Samples (mud, homogenized soft mats and endoevaporites) were incubated anaerobically with deoxygenated site water, and the increase in methane concentration through time in the headspaces of the incubation vials was used to determine methane production rates. To ascertain the substrates used by the methanogens, 13C-labeled methylamines, methanol, dimethylsulfide, acetate or bicarbonate were added to the incubations (one substrate per vial) and the stable isotopic composition of the resulting methane was measured. The vials amended with 13C-labeled methylamines produced the most 13C-enriched methane, generally followed by the 13C-labeled methanol-amended vials. The stable isotope data and the methane production rates were used to determine first order rate constants for each of the substrates at each of the sites. Estimates of individual substrate use revealed that the methylamines produced 55 to 92% of the methane generated, while methanol was responsible for another 8 to 40%.

  10. Intracellular Mono-ADP-Ribosylation in Signaling and Disease

    PubMed Central

    Bütepage, Mareike; Eckei, Laura; Verheugd, Patricia; Lüscher, Bernhard

    2015-01-01

    A key process in the regulation of protein activities and thus cellular signaling pathways is the modification of proteins by post-translational mechanisms. Knowledge about the enzymes (writers and erasers) that attach and remove post-translational modifications, the targets that are modified and the functional consequences elicited by specific modifications, is crucial for understanding cell biological processes. Moreover detailed knowledge about these mechanisms and pathways helps to elucidate the molecular causes of various diseases and in defining potential targets for therapeutic approaches. Intracellular adenosine diphosphate (ADP)-ribosylation refers to the nicotinamide adenine dinucleotide (NAD+)-dependent modification of proteins with ADP-ribose and is catalyzed by enzymes of the ARTD (ADP-ribosyltransferase diphtheria toxin like, also known as PARP) family as well as some members of the Sirtuin family. Poly-ADP-ribosylation is relatively well understood with inhibitors being used as anti-cancer agents. However, the majority of ARTD enzymes and the ADP-ribosylating Sirtuins are restricted to catalyzing mono-ADP-ribosylation. Although writers, readers and erasers of intracellular mono-ADP-ribosylation have been identified only recently, it is becoming more and more evident that this reversible post-translational modification is capable of modulating key intracellular processes and signaling pathways. These include signal transduction mechanisms, stress pathways associated with the endoplasmic reticulum and stress granules, and chromatin-associated processes such as transcription and DNA repair. We hypothesize that mono-ADP-ribosylation controls, through these different pathways, the development of cancer and infectious diseases. PMID:26426055

  11. Mono- and bis-thiazolium salts have potent antimalarial activity.

    PubMed

    Hamzé, Abdallah; Rubi, Eric; Arnal, Pascal; Boisbrun, Michel; Carcel, Carole; Salom-Roig, Xavier; Maynadier, Marjorie; Wein, Sharon; Vial, Henri; Calas, Michèle

    2005-05-19

    Three new series comprising 24 novel cationic choline analogues and consisting of mono- or bis (N or C-5-duplicated) thiazolium salts have been synthesized. Bis-thiazolium salts showed potent antimalarial activity (much superior to monothiazoliums). Among them, bis-thiazolium salts 12 and 13 exhibited IC(50) values of 2.25 nM and 0.65 nM, respectively, against P. falciparum in vitro. These compounds also demonstrated good in vivo activity (ED(50)

  12. New mono- and diethynylsiloxysilsesquioxanes--efficient procedures for their synthesis.

    PubMed

    Dudziec, Beata; Rzonsowska, Monika; Marciniec, Bogdan; Brząkalski, Dariusz; Woźniak, Bartosz

    2014-09-21

    Ethynyl-substituted siloxysilsesquioxanes are promising building blocks for a wide range of substances based on a POSS/DDSQ core, especially for (oligo-)polymer syntheses and modifications (the formation of hybrid materials with interesting photophysical and mechanical properties). In this study, we report on a series of new mono- and diethynylsiloxysilsesquioxanes formed via an efficient and highly selective one-pot process from silsesquioxanes with reactive Si-OH groups based on sequential condensation, hydrolysis, chlorination and substitution reactions. All newly synthesized compounds were isolated and characterized by spectroscopic methods. PMID:25047114

  13. The metal centres of particulate methane mono-oxygenase.

    PubMed

    Rosenzweig, Amy C

    2008-12-01

    pMMO (particulate methane mono-oxygenase) is an integral membrane metalloenzyme that catalyses the oxidation of methane to methanol. The pMMO metal active site has not been identified, precluding detailed investigation of the reaction mechanism. Models for the metal centres proposed by various research groups have evolved as crystallographic and spectroscopic data have become available. The present review traces the evolution of these active-site models before and after the 2005 Methylococcus capsulatus (Bath) pMMO crystal structure determination. PMID:19021511

  14. Digital Map of Tephra Deposits of the Mono-Inyo Craters, CA

    NASA Astrophysics Data System (ADS)

    Rogova, G.; Bursik, M. I.; Sieh, K. E.; Meltzner, A. J.; Dennen, R. L.; Collins, R.; Dahn, N.; Lagamba, M.; Shufelt, C.; Weinerth, J.

    2010-12-01

    The Mono-Inyo Craters have erupted numerous times in the Holocene. Radiocarbon dating suggests eruption sequences < 1302-1356 calBP (2 sigma; Southern Mono Craters), < 1520-1628 calBP (Northern Mono Craters), > 1405-1528 calBP (Northwest Negit Island), < 1611-1710 calBP (Wilson's Butte), < 1987-2212 calBP (Central(?) Mono Craters), < 3395-3632 calBP (Southern Mono Craters), < 5039-5297 calBP (Southern Mono -- Inyo Craters) and < 9282-9635 calBP (Mono Craters). These eruptions are in addition to those already known and previously dated from the North Mono area, Inyo Craters, Mammoth Mountain Craters, and the islands of Mono Lake. Data on spatial position, age, thickness, grain size, componentry, geochemistry, etc., have been entered into a spatially enabled, PostgreSQL relational database. These data are searchable, and retrievable through-the-web as either spreadsheets or shapefiles. Algorithms for layer matching by geochemistry or lithology, isopaching and grain-size isoplething allow the downloaded data to be investigated for possible correlation, volume calculation and other analysis. Use of the digital database and associated tools has already allowed us to determine provenance of certain tephra layers, cluster tephra sources by geochemistry, correlate previously uncategorized tephra occurrences to known layers and automatically estimate tephra volume.

  15. Selective Mono-reduction of Pyrrole-2,5 and 2,4-Dicarboxylates.

    PubMed

    Yasui, Eiko; Tsuda, Jyunpei; Ohnuki, Satoshi; Nagumo, Shinji

    2016-01-01

    Pyrrole-2,5-dicarboxylates were rapidly and selectively reduced to the corresponding mono-alcohol using 3 eq of diisobutylaluminum hydride at 0°C. Pyrrole-2,4-dicarboxylate showed the same reactivity; however, the selectivity decreased with pyrrole-3,4-dicarboxylate. When the nitrogen atom of the pyrrole-2,5-dicarboxylate is protected with a benzyl group, selective mono-reduction does not occur. Considering that furan-2,5-dicarboxylates did not give the corresponding mono-alcohol under the same conditions, the unprotected nitrogen atom of pyrrole apparently plays an important role in this selective mono-reduction. PMID:27581630

  16. The influence of solution stoichiometry on surface-controlled Ca isotope fractionation during Ca carbonate precipitation from Mono Lake, California

    NASA Astrophysics Data System (ADS)

    Nielsen, L. C.; Depaolo, D. J.

    2010-12-01

    Precipitation of calcite and aragonite from aqueous solution causes kinetic stable Ca isotope fractionation under conditions where Ca2+ is greatly in excess of CO32-. Research on carbonate mineral growth from low Ca2+:CO32- activity ratio solutions is lacking. Mono Lake, California is a highly alkaline lake with a Ca2+:CO32- activity ratio of 9.6 x 10-4, over five orders of magnitude lower than typical terrestrial fresh and ocean water. Aragonitic tufa towers grow along the lakeshore due to the mixing of lake water and Ca-rich spring water, while fine aragonite particles precipitate directly from the lake water, accumulating on the lake bottom. Variations in the Ca2+:CO32- activity ratio affect calcite growth kinetics and could affect the partitioning of Ca isotopes during carbonate precipitation. However, the relationship between solution stoichiometry, microscopic mineral growth mechanisms and calcium isotope fractionation is poorly understood. We analyzed the Sr and Ca isotopic compositions of a suite of lake water, spring, tufa and lake bottom sediment samples from the Mono Basin. Using the Sr isotope signatures of endmember water sources (pure lake water and shoreline spring water), we determined the compositions of carbonate mineral growth solutions, associated isotope separations (Δ44/40Cas-f = δ44/40Casolid - δ44/40Cafluid) and precipitation rates. While lake bottom aragonite precipitates directly from lake water (Ca2+:CO32- ≈ 10-3), tufa grows from mixed solutions with Ca2+:CO32- activity ratios approaching 10, so carbonate precipitation in Mono Lake spans a four order of magnitude range in solution stoichiometry. At Mono Lake, Δ44/40Cas-f and calculated precipitation rates vary between -0.6±0.15‰ at 1.5×10-9 mol m-2 s-1 for aragonite precipitating from lake water and ~ -1.0±0.15‰ at up to 4×10-8 mol m-2 s-1 for tufa growing from mixed spring and lake water. These values are consistent with fractionation observed during CaCO3 precipitation at

  17. Crustal structure between Lake Mead, Nevada, and Mono Lake, California

    USGS Publications Warehouse

    Johnson, Lane R.

    1964-01-01

    Interpretation of a reversed seismic-refraction profile between Lake Mead, Nevada, and Mono Lake, California, indicates velocities of 6.15 km/sec for the upper layer of the crust, 7.10 km/sec for an intermediate layer, and 7.80 km/sec for the uppermost mantle. Phases interpreted to be reflections from the top of the intermediate layer and the Mohorovicic discontinuity were used with the refraction data to calculate depths. The depth to the Moho increases from about 30 km near Lake Mead to about 40 km near Mono Lake. Variations in arrival times provide evidence for fairly sharp flexures in the Moho. Offsets in the Moho of 4 km at one point and 2 1/2 km at another correspond to large faults at the surface, and it is suggested that fracture zones in the upper crust may displace the Moho and extend into the upper mantle. The phase P appears to be an extension of the reflection from the top of the intermediate layer beyond the critical angle. Bouguer gravity, computed for the seismic model of the crust, is in good agreement with the measured Bouguer gravity. Thus a model of the crustal structure is presented which is consistent with three semi-independent sources of geophysical data: seismic-refraction, seismic-reflection, and gravity.

  18. Characterization of Mono- and Mixed-Culture Campylobacter jejuni Biofilms

    PubMed Central

    Ica, Tuba; Caner, Vildan; Istanbullu, Ozlem; Nguyen, Hung Duc; Ahmed, Bulbul; Call, Douglas R.

    2012-01-01

    Campylobacter jejuni, one of the most common causes of human gastroenteritis, is a thermophilic and microaerophilic bacterium. These characteristics make it a fastidious organism, which limits its ability to survive outside animal hosts. Nevertheless, C. jejuni can be transmitted to both humans and animals via environmental pathways, especially through contaminated water. Biofilms may play a crucial role in the survival of the bacterium under unfavorable environmental conditions. The goal of this study was to investigate survival strategies of C. jejuni in mono- and mixed-culture biofilms. We grew monoculture biofilms of C. jejuni and mixed-culture biofilms of C. jejuni with Pseudomonas aeruginosa. We found that mono- and mixed-culture biofilms had significantly different structures and activities. Monoculture C. jejuni biofilms did not consume a measurable quantity of oxygen. Using a confocal laser scanning microscope (CLSM), we found that cells from monoculture biofilms were alive according to live/dead staining but that these cells were not culturable. In contrast, in mixed-culture biofilms, C. jejuni remained in a culturable physiological state. Monoculture C. jejuni biofilms could persist under lower flow rates (0.75 ml/min) but were unable to persist at higher flow rates (1 to 2.5 ml/min). In sharp contrast, mixed-culture biofilms were more robust and were unaffected by higher flow rates (2.5 ml/min). Our results indicate that biofilms provide an environmental refuge that is conducive to the survival of C. jejuni. PMID:22179238

  19. MonoSLAM: real-time single camera SLAM.

    PubMed

    Davison, Andrew J; Reid, Ian D; Molton, Nicholas D; Stasse, Olivier

    2007-06-01

    We present a real-time algorithm which can recover the 3D trajectory of a monocular camera, moving rapidly through a previously unknown scene. Our system, which we dub MonoSLAM, is the first successful application of the SLAM methodology from mobile robotics to the "pure vision" domain of a single uncontrolled camera, achieving real time but drift-free performance inaccessible to Structure from Motion approaches. The core of the approach is the online creation of a sparse but persistent map of natural landmarks within a probabilistic framework. Our key novel contributions include an active approach to mapping and measurement, the use of a general motion model for smooth camera movement, and solutions for monocular feature initialization and feature orientation estimation. Together, these add up to an extremely efficient and robust algorithm which runs at 30 Hz with standard PC and camera hardware. This work extends the range of robotic systems in which SLAM can be usefully applied, but also opens up new areas. We present applications of MonoSLAM to real-time 3D localization and mapping for a high-performance full-size humanoid robot and live augmented reality with a hand-held camera. PMID:17431302

  20. Matrix diffusion of some alkali- and alkaline earth-metals in granitic rock

    SciTech Connect

    Johansson, H.; Byegaard, J.; Skarnemark, G.; Skaalberg, M.

    1997-12-31

    Static through-diffusion experiments were performed to study the diffusion of alkali- and alkaline earth-metals in fine-grained granite and medium-grained Aespoe-diorite. Tritiated water was used as an inert reference tracer. Radionuclides of the alkali- and alkaline earth-metals (mono- and divalent elements which are not influenced by hydrolysis in the pH-range studied) were used as tracers, i.e., {sup 22}Na{sup +}, {sup 45}Ca{sup 2+} and {sup 85}Sr{sup 2+}. The effective diffusivity and the rock capacity factor were calculated by fitting the breakthrough curve to the one-dimensional solution of the diffusion equation. Sorption coefficients, K{sub d}, that were derived from the rock capacity factor (diffusion experiments) were compared with K{sub d} determined in batch experiments using crushed material of different size fractions. The results show that the tracers were retarded in the same order as was expected from the measured batch K{sub d}. Furthermore, the largest size fraction was the most representative when comparing batch K{sub d} with K{sub d} evaluated from the diffusion experiments. The observed effective diffusivities tended to decrease with increasing cell lengths, indicating that the transport porosity decreases with increasing sample lengths used in the diffusion experiments.

  1. Intermediate range order in alkaline borate glasses

    NASA Astrophysics Data System (ADS)

    Crupi, C.; Carini, G.; Ruello, G.; D'Angelo, G.

    2016-03-01

    We describe the neutron diffraction patterns of a series of alkaline borate glasses at different metal oxide content. Strong differences are observed in the intermediate range order as a function of the specific alkaline ion and of its concentration. On these results, we propose that the first sharp diffraction peak arises from correlations of atoms of voids and show that the compositional variation of this peak intensity in alkaline borate glasses is due to changes in the distribution of void sizes within the three-dimensional network. We argue that our interpretation in terms of interstitial (empty and/or filled) voids, having different sizes, provides a general explanation for all anomalous behaviours revealed for the first sharp diffraction peak.

  2. Degradation of halogenated carbons in alkaline alcohol

    NASA Astrophysics Data System (ADS)

    Nakagawa, Seiko; Shimokawa, Toshinari

    2002-02-01

    1,1,2-Trichloro-trifluoroethane, 1,2-dibromo-tetrafluoroethane, 2,3,4,6-tetrachlorophenol, 1,2,4-trichlorobenzene, and 2,4,6-trichloroanisole were dissolved in alkaline isopropyl alcohol and irradiated with 60Co gamma rays after purged with pure nitrogen gas. The concentration of the hydroxide ions and the parent molecules decreased with the dose, while that of the halide ions and the organic products, with less halogen atoms than the parent, increased. Chain degradation will occur in alkaline isopropyl alcohol.

  3. Alkaline earth filled nickel skutterudite antimonide thermoelectrics

    DOEpatents

    Singh, David Joseph

    2013-07-16

    A thermoelectric material including a body centered cubic filled skutterudite having the formula A.sub.xFe.sub.yNi.sub.zSb.sub.12, where A is an alkaline earth element, x is no more than approximately 1.0, and the sum of y and z is approximately equal to 4.0. The alkaline earth element includes guest atoms selected from the group consisting of Be, Mb, Ca, Sr, Ba, Ra and combinations thereof. The filled skutterudite is shown to have properties suitable for a wide variety of thermoelectric applications.

  4. Laser direct write of planar alkaline microbatteries

    NASA Astrophysics Data System (ADS)

    Arnold, C. B.; Kim, H.; Piqué, A.

    We are developing a laser engineering approach to fabricate and optimize alkaline microbatteries in planar geometries. The laser direct-write technique enables multicapability for adding, removing and processing material and provides the ability to pattern complicated structures needed for fabricating complete microbattery assemblies. In this paper, we demonstrate the production of planar zinc-silver oxide alkaline cells under ambient conditions. The microbattery cells exhibit 1.55-V open-circuit potentials, as expected for the battery chemistry, and show a flat discharge behavior under constant-current loads. High capacities of over 450 μAhcm-2 are obtained for 5-mm2 microbatteries.

  5. Alkaline Capacitors Based on Nitride Nanoparticles

    NASA Technical Reports Server (NTRS)

    Aldissi, Matt

    2003-01-01

    High-energy-density alkaline electrochemical capacitors based on electrodes made of transition-metal nitride nanoparticles are undergoing development. Transition- metal nitrides (in particular, Fe3N and TiN) offer a desirable combination of high electrical conductivity and electrochemical stability in aqueous alkaline electrolytes like KOH. The high energy densities of these capacitors are attributable mainly to their high capacitance densities, which, in turn, are attributable mainly to the large specific surface areas of the electrode nanoparticles. Capacitors of this type could be useful as energy-storage components in such diverse equipment as digital communication systems, implanted medical devices, computers, portable consumer electronic devices, and electric vehicles.

  6. Sediment characteristics and water quality in the two hyper-saline lagoons along the Red Sea coast of Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Rasul, Najeeb; Al-Farawati, Radwan; Al-Harbi, Omer; Naser Qutub, Abdul

    2013-04-01

    The two hyper-saline Shoaiba lagoons, Khawr ash Shaibah al Masdudah (northern lagoon) and Khawr ash Shaibah al Maftuhah (southern lagoon) have a unique environmental set-up because no rivers or wadis flow into the lagoons and therefore detrital material to the lagoons is lacking and most of the sediments are indigenous carbonates. The biogenic material is mostly derived from coral debris, coralline algae and molluscs abundant in gravel and sand size fractions. The evaporite deposits from the adjoining sabkhas are transported to the lagoon during tidal cycles. Carbonate is abundant in the form of aragonite and High Mg-calcite indicating carbonate to be recent and formed under shallow water conditions. In general, the sediments are the result of the mechanical breakdown of molluscs and coral reefs by either human activity or by coral boring marine organisms and physical processes such as tidal and wind generated currents. Strong currents dominate only the deeper part at the entrance of the lagoons that causes the winnowing of the finer sediments, and its transportation during flooding and ebbing. Shallow depths averaging 3 m, wind and tidal stirring are the main forces preventing the lagoons from developing stratification resulting in a well-mixed body of water. The shallow depth of the lagoons keep the turbidity levels higher, whereas salinity as high as 52 ‰ and water temperature as high as 38 °C helps in the formation of halite at the periphery. The cyclical inundation of sabkhas by a thin sheet of water during tidal cycles is important in understanding the ecological consequence. Mangrove stands in the lagoons act as a source of nutrients to the flora and fauna inhabiting the lagoons. The configurations of the mouth of the lagoons influence the tidal currents, including the sediment and water movement. The tidal current is enhanced as it enters the lagoons, in response to the funneling effect caused by the narrow channel. The current diffuses as the entrance

  7. The Comparative Osmoregulatory Ability of Two Water Beetle Genera Whose Species Span the Fresh-Hypersaline Gradient in Inland Waters (Coleoptera: Dytiscidae, Hydrophilidae)

    PubMed Central

    Pallarés, Susana; Arribas, Paula; Bilton, David T.; Millán, Andrés; Velasco, Josefa

    2015-01-01

    A better knowledge of the physiological basis of salinity tolerance is essential to understanding the ecology and evolutionary history of organisms that have colonized inland saline waters. Coleoptera are amongst the most diverse macroinvertebrates in inland waters, including saline habitats; however, the osmoregulatory strategies they employ to deal with osmotic stress remain unexplored. Survival and haemolymph osmotic concentration at different salinities were examined in adults of eight aquatic beetle species which inhabit different parts of the fresh—hypersaline gradient. Studied species belong to two unrelated genera which have invaded saline waters independently from freshwater ancestors; Nebrioporus (Dytiscidae) and Enochrus (Hydrophilidae). Their osmoregulatory strategy (osmoconformity or osmoregulation) was identified and osmotic capacity (the osmotic gradient between the animal’s haemolymph and the external medium) was compared between species pairs co-habiting similar salinities in nature. We show that osmoregulatory capacity, rather than osmoconformity, has evolved independently in these different lineages. All species hyperegulated their haemolymph osmotic concentration in diluted waters; those living in fresh or low-salinity waters were unable to hyporegulate and survive in hyperosmotic media (> 340 mosmol kg-1). In contrast, the species which inhabit the hypo-hypersaline habitats were effective hyporegulators, maintaining their haemolymph osmolality within narrow limits (ca. 300 mosmol kg-1) across a wide range of external concentrations. The hypersaline species N. ceresyi and E. jesusarribasi tolerated conductivities up to 140 and 180 mS cm-1, respectively, and maintained osmotic gradients over 3500 mosmol kg-1, comparable to those of the most effective insect osmoregulators known to date. Syntopic species of both genera showed similar osmotic capacities and in general, osmotic responses correlated well with upper salinity levels occupied by

  8. Trimethylamine and Organic Matter Additions Reverse Substrate Limitation Effects on the δ13C Values of Methane Produced in Hypersaline Microbial Mats.

    PubMed

    Kelley, Cheryl A; Nicholson, Brooke E; Beaudoin, Claire S; Detweiler, Angela M; Bebout, Brad M

    2014-12-01

    Methane production has been observed in a number of hypersaline environments, and it is generally thought that this methane is produced through the use of noncompetitive substrates, such as the methylamines, dimethylsulfide and methanol. Stable isotope measurements of the produced methane have also suggested that the methanogens are operating under conditions of substrate limitation. Here, substrate limitation in gypsum-hosted endoevaporite and soft-mat hypersaline environments was investigated by the addition of trimethylamine, a noncompetitive substrate for methanogenesis, and dried microbial mat, a source of natural organic matter. The δ(13)C values of the methane produced after amendments were compared to those in unamended control vials. At all hypersaline sites investigated, the δ(13)C values of the methane produced in the amended vials were statistically lower (by 10 to 71‰) than the unamended controls, supporting the hypothesis of substrate limitation at these sites. When substrates were added to the incubation vials, the methanogens within the vials fractionated carbon isotopes to a greater degree, resulting in the production of more (13)C-depleted methane. Trimethylamine-amended samples produced lower methane δ(13)C values than the mat-amended samples. This difference in the δ(13)C values between the two types of amendments could be due to differences in isotope fractionation associated with the dominant methane production pathway (or substrate used) within the vials, with trimethylamine being the main substrate used in the trimethylamine-amended vials. It is hypothesized that increased natural organic matter in the mat-amended vials would increase fermentation rates, leading to higher H2 concentrations and increased CO2/H2 methanogenesis. PMID:25239903

  9. Trimethylamine and Organic Matter Additions Reverse Substrate Limitation Effects on the δ13C Values of Methane Produced in Hypersaline Microbial Mats

    PubMed Central

    Nicholson, Brooke E.; Beaudoin, Claire S.; Detweiler, Angela M.; Bebout, Brad M.

    2014-01-01

    Methane production has been observed in a number of hypersaline environments, and it is generally thought that this methane is produced through the use of noncompetitive substrates, such as the methylamines, dimethylsulfide and methanol. Stable isotope measurements of the produced methane have also suggested that the methanogens are operating under conditions of substrate limitation. Here, substrate limitation in gypsum-hosted endoevaporite and soft-mat hypersaline environments was investigated by the addition of trimethylamine, a noncompetitive substrate for methanogenesis, and dried microbial mat, a source of natural organic matter. The δ13C values of the methane produced after amendments were compared to those in unamended control vials. At all hypersaline sites investigated, the δ13C values of the methane produced in the amended vials were statistically lower (by 10 to 71‰) than the unamended controls, supporting the hypothesis of substrate limitation at these sites. When substrates were added to the incubation vials, the methanogens within the vials fractionated carbon isotopes to a greater degree, resulting in the production of more 13C-depleted methane. Trimethylamine-amended samples produced lower methane δ13C values than the mat-amended samples. This difference in the δ13C values between the two types of amendments could be due to differences in isotope fractionation associated with the dominant methane production pathway (or substrate used) within the vials, with trimethylamine being the main substrate used in the trimethylamine-amended vials. It is hypothesized that increased natural organic matter in the mat-amended vials would increase fermentation rates, leading to higher H2 concentrations and increased CO2/H2 methanogenesis. PMID:25239903

  10. Abundance, Distribution, and Activity of Fe(II)-Oxidizing and Fe(III)-Reducing Microorganisms in Hypersaline Sediments of Lake Kasin, Southern Russia

    PubMed Central

    Emmerich, Maren; Bhansali, Ankita; Lösekann-Behrens, Tina; Schröder, Christian; Kappler, Andreas

    2012-01-01

    The extreme osmotic conditions prevailing in hypersaline environments result in decreasing metabolic diversity with increasing salinity. Various microbial metabolisms have been shown to occur even at high salinity, including photosynthesis as well as sulfate and nitrate reduction. However, information about anaerobic microbial iron metabolism in hypersaline environments is scarce. We studied the phylogenetic diversity, distribution, and metabolic activity of iron(II)-oxidizing and iron(III)-reducing Bacteria and Archaea in pH-neutral, iron-rich salt lake sediments (Lake Kasin, southern Russia; salinity, 348.6 g liter−1) using a combination of culture-dependent and -independent techniques. 16S rRNA gene clone libraries for Bacteria and Archaea revealed a microbial community composition typical for hypersaline sediments. Most-probable-number counts confirmed the presence of 4.26 × 102 to 8.32 × 103 iron(II)-oxidizing Bacteria and 4.16 × 102 to 2.13 × 103 iron(III)-reducing microorganisms per gram dry sediment. Microbial iron(III) reduction was detected in the presence of 5 M NaCl, extending the natural habitat boundaries for this important microbial process. Quantitative real-time PCR showed that 16S rRNA gene copy numbers of total Bacteria, total Archaea, and species dominating the iron(III)-reducing enrichment cultures (relatives of Halobaculum gomorrense, Desulfosporosinus lacus, and members of the Bacilli) were highest in an iron oxide-rich sediment layer. Combined with the presented geochemical and mineralogical data, our findings suggest the presence of an active microbial iron cycle at salt concentrations close to the solubility limit of NaCl. PMID:22504804

  11. Application of factor analysis and electrical resistivity to understand groundwater contributions to coastal embayments in semi-arid and hypersaline coastal settings.

    PubMed

    Bighash, Paniz; Murgulet, Dorina

    2015-11-01

    Groundwater contributions and sources of salinity to Oso Bay in south Texas were investigated using multivariate statistical analysis of geochemical data and multitemporal electrical resistivity tomography surveys. Both analysis of geochemical data and subsurface imaging techniques identified two commonalities for the investigated system: 1) hypersaline water occurs near the groundwater/surface water interface during wet conditions creating reverse hydraulic gradients due to density effects. The development and downward movement of these fluids as continuous plumes deflect fresher groundwater discharge downward and laterally away from the surface; and 2) more pronounced upwelling of fresher groundwater occurs during drought periods when density inversions are more defined and are expected to overcome dispersion and diffusion processes and create sufficiently large-enough unstable gradients that induce density-difference convection. Salinity mass-balance models derived from time-difference resistivity tomograph and in-situ salinity data reaffirm these findings indicating that groundwater upwelling is more prominent during dry to wet conditions in 2013 (~545.5m(3)/d) and is less pronounced during wet to dry conditions in 2012 (~262.7 m(3)/d) for the 224 m(2) area surveyed. Findings show that the highly saline nature of water in this area and changes in salinity regimes can be attributed to a combination of factors, namely: surface outflows, evapoconcentration, recirculation of hypersaline groundwaters, and potential trapped oil field brines. Increased drought conditions will likely exacerbate the rate at which salinity levels are increasing in bays and estuaries in semi-arid regions where both hypersaline groundwater discharge and high evaporation rates occur simultaneously. PMID:26119383

  12. The Effects of Trimethylamine and Organic Matter Additions on the Stable Carbon Isotopic Composition of Methane Produced in Hypersaline Microbial Mat Environments

    NASA Astrophysics Data System (ADS)

    Kelley, C. A.; Nicholson, B. E.; Beaudoin, C. S.; Detweiler, A. M.; Bebout, B.

    2014-12-01

    Methane production has been observed in a number of hypersaline environments, and it is generally thought that this methane is produced through the use of non-competitive substrates, such as the methylamines, methanol and dimethylsulfide. The stable carbon isotopic composition of the produced methane has suggested that the methanogens are operating under conditions of substrate limitation. We investigated substrate limitation in gypsum-hosted endoevaporite and soft mat hypersaline environments by the additions of trimethylamine, a non-competitive substrate for methanogenesis, and dried microbial mat, a source of natural organic matter. The δ13C values of the methane produced after amendments were compared to those in unamended control vials. At all hypersaline sites investigated, the δ13C values of the methane produced in the amended vials were statistically lower (by 10 to 71 ‰) than the unamended controls, supporting the hypothesis of substrate limitation at these sites. When substrates were added to the incubation vials, the methanogens within the vials fractionated carbon isotopes to a greater degree, resulting in the production of more 13C-depleted methane. Trimethylamine-amended samples produced lower methane δ13C values than the mat-amended samples. This difference in the δ13C values between the two types of amendments could be due to differences in isotope fractionation associated with the dominant methane production pathway (or substrate used) within the vials, with trimethylamine being the main substrate used in the trimethylamine-amended vials. We hypothesize that increased natural organic matter in the mat-amended vials would increase fermentation rates, leading to higher H2 concentrations and increased CO2/H2 methanogenesis.

  13. The comparative osmoregulatory ability of two water beetle genera whose species span the fresh-hypersaline gradient in inland waters (Coleoptera: Dytiscidae, Hydrophilidae).

    PubMed

    Pallarés, Susana; Arribas, Paula; Bilton, David T; Millán, Andrés; Velasco, Josefa

    2015-01-01

    A better knowledge of the physiological basis of salinity tolerance is essential to understanding the ecology and evolutionary history of organisms that have colonized inland saline waters. Coleoptera are amongst the most diverse macroinvertebrates in inland waters, including saline habitats; however, the osmoregulatory strategies they employ to deal with osmotic stress remain unexplored. Survival and haemolymph osmotic concentration at different salinities were examined in adults of eight aquatic beetle species which inhabit different parts of the fresh-hypersaline gradient. Studied species belong to two unrelated genera which have invaded saline waters independently from freshwater ancestors; Nebrioporus (Dytiscidae) and Enochrus (Hydrophilidae). Their osmoregulatory strategy (osmoconformity or osmoregulation) was identified and osmotic capacity (the osmotic gradient between the animal's haemolymph and the external medium) was compared between species pairs co-habiting similar salinities in nature. We show that osmoregulatory capacity, rather than osmoconformity, has evolved independently in these different lineages. All species hyperegulated their haemolymph osmotic concentration in diluted waters; those living in fresh or low-salinity waters were unable to hyporegulate and survive in hyperosmotic media (> 340 mosmol kg(-1)). In contrast, the species which inhabit the hypo-hypersaline habitats were effective hyporegulators, maintaining their haemolymph osmolality within narrow limits (ca. 300 mosmol kg(-1)) across a wide range of external concentrations. The hypersaline species N. ceresyi and E. jesusarribasi tolerated conductivities up to 140 and 180 mS cm(-1), respectively, and maintained osmotic gradients over 3500 mosmol kg(-1), comparable to those of the most effective insect osmoregulators known to date. Syntopic species of both genera showed similar osmotic capacities and in general, osmotic responses correlated well with upper salinity levels occupied by

  14. The influence of salinity on D/H fractionation in dinosterol and brassicasterol from globally distributed saline and hypersaline lakes

    NASA Astrophysics Data System (ADS)

    Nelson, Daniel B.; Sachs, Julian P.

    2014-05-01

    Salinity, growth rate, growth stage, nutrient limitation and temperature have all been shown to influence the magnitude of D/H fractionation in algal lipids through laboratory and field studies. Of these factors, salinity has been studied most extensively in the field, but to date all such investigations have focused on transect studies within specific and isolated environments. Here we test the relationship between salinity and the magnitude of D/H fractionation in algal lipids through paired analyses of sedimentary and particulate lipid and water hydrogen isotope values at a wide range of continental and coastal lake sites spanning salinities from 0 to 117 ppt. Our results demonstrate broad consistency between D/H fractionations in dinosterol and brassicasterol with those obtained from previous work, with salinity changes of 1 ppt resulting in lipid δD changes of 0.7-1‰. Although our results also show variability in D/H fractionation between sites that is not related to salinity, the fact that any relationship emerges above the influences of other factors suggests that the salinity effect is dominant for some lipids in the majority of saline to hypersaline environments. This improved understanding of D/H fractionation in dinosterol and brassicasterol synthesis supports the use of these compounds as paleohydrologic indicators. When combined with D/H measurements from a second lipid or oxygen isotope measurements from carbonate, quantitative reconstructions of salinity and lake water isotope changes are possible. Extending the number of algal lipids within which a consistent relationship between D/H fractionation and salinity has been identified also supports the notion that the relationship is widespread among unicellular photoautotrophs.

  15. Microbial Diversity in Sediment Ecosystems (Evaporites Domes, Microbial Mats, and Crusts) of Hypersaline Laguna Tebenquiche, Salar de Atacama, Chile.

    PubMed

    Fernandez, Ana B; Rasuk, Maria C; Visscher, Pieter T; Contreras, Manuel; Novoa, Fernando; Poire, Daniel G; Patterson, Molly M; Ventosa, Antonio; Farias, Maria E

    2016-01-01

    We combined nucleic acid-based molecular methods, biogeochemical measurements, and physicochemical characteristics to investigate microbial sedimentary ecosystems of Laguna Tebenquiche, Atacama Desert, Chile. Molecular diversity, and biogeochemistry of hypersaline microbial mats, rhizome-associated concretions, and an endoevaporite were compared with: The V4 hypervariable region of the 16S rRNA gene was amplified by pyrosequencing to analyze the total microbial diversity (i.e., bacteria and archaea) in bulk samples, and in addition, in detail on a millimeter scale in one microbial mat and in one evaporite. Archaea were more abundant than bacteria. Euryarchaeota was one of the most abundant phyla in all samples, and particularly dominant (97% of total diversity) in the most lithified ecosystem, the evaporite. Most of the euryarchaeal OTUs could be assigned to the class Halobacteria or anaerobic and methanogenic archaea. Planctomycetes potentially also play a key role in mats and rhizome-associated concretions, notably the aerobic organoheterotroph members of the class Phycisphaerae. In addition to cyanobacteria, members of Chromatiales and possibly the candidate family Chlorotrichaceae contributed to photosynthetic carbon fixation. Other abundant uncultured taxa such as the candidate division MSBL1, the uncultured MBGB, and the phylum Acetothermia potentially play an important metabolic role in these ecosystems. Lithifying microbial mats contained calcium carbonate precipitates, whereas endoevoporites consisted of gypsum, and halite. Biogeochemical measurements revealed that based on depth profiles of O2 and sulfide, metabolic activities were much higher in the non-lithifying mat (peaking in the least lithified systems) than in lithifying mats with the lowest activity in endoevaporites. This trend in decreasing microbial activity reflects the increase in salinity, which may play an important role in the biodiversity. PMID:27597845

  16. Microbial Diversity in Sediment Ecosystems (Evaporites Domes, Microbial Mats, and Crusts) of Hypersaline Laguna Tebenquiche, Salar de Atacama, Chile

    PubMed Central

    Fernandez, Ana B.; Rasuk, Maria C.; Visscher, Pieter T.; Contreras, Manuel; Novoa, Fernando; Poire, Daniel G.; Patterson, Molly M.; Ventosa, Antonio; Farias, Maria E.

    2016-01-01

    We combined nucleic acid-based molecular methods, biogeochemical measurements, and physicochemical characteristics to investigate microbial sedimentary ecosystems of Laguna Tebenquiche, Atacama Desert, Chile. Molecular diversity, and biogeochemistry of hypersaline microbial mats, rhizome-associated concretions, and an endoevaporite were compared with: The V4 hypervariable region of the 16S rRNA gene was amplified by pyrosequencing to analyze the total microbial diversity (i.e., bacteria and archaea) in bulk samples, and in addition, in detail on a millimeter scale in one microbial mat and in one evaporite. Archaea were more abundant than bacteria. Euryarchaeota was one of the most abundant phyla in all samples, and particularly dominant (97% of total diversity) in the most lithified ecosystem, the evaporite. Most of the euryarchaeal OTUs could be assigned to the class Halobacteria or anaerobic and methanogenic archaea. Planctomycetes potentially also play a key role in mats and rhizome-associated concretions, notably the aerobic organoheterotroph members of the class Phycisphaerae. In addition to cyanobacteria, members of Chromatiales and possibly the candidate family Chlorotrichaceae contributed to photosynthetic carbon fixation. Other abundant uncultured taxa such as the candidate division MSBL1, the uncultured MBGB, and the phylum Acetothermia potentially play an important metabolic role in these ecosystems. Lithifying microbial mats contained calcium carbonate precipitates, whereas endoevoporites consisted of gypsum, and halite. Biogeochemical measurements revealed that based on depth profiles of O2 and sulfide, metabolic activities were much higher in the non-lithifying mat (peaking in the least lithified systems) than in lithifying mats with the lowest activity in endoevaporites. This trend in decreasing microbial activity reflects the increase in salinity, which may play an important role in the biodiversity. PMID:27597845

  17. Association of a new type of gliding, filamentous, purple phototrophic bacterium inside bundles of Microcoleus chthonoplastes in hypersaline cyanobacterial mats

    NASA Technical Reports Server (NTRS)

    D'Amelio, E. D.; Cohen, Y.; Des Marais, D. J.

    1987-01-01

    An unidentified filamentous purple bacterium, probably belonging to a new genus or even a new family, is found in close association with the filamentous, mat-forming cyanobacterium Microcoleus chthonoplastes in a hypersaline pond at Guerrero Negro, Baja California Sur, Mexico, and in Solar Lake, Sinai, Egypt. This organism is a gliding, segmented trichome, 0.8-0.9 micrometer wide. It contains intracytoplasmic stacked lamellae which are perpendicular and obliquely oriented to the cell wall, similar to those described for the purple sulfur bacteria Ectothiorhodospira. These bacteria are found inside the cyanobacterial bundle, enclosed by the cyanobacterial sheath. Detailed transmission electron microscopical analyses carried out in horizontal sections of the upper 1.5 mm of the cyanobacterial mat show this cyanobacterial-purple bacterial association at depths of 300-1200 micrometers, corresponding to the zone below that of maximal oxygenic photosynthesis. Sharp gradients of oxygen and sulfide are established during the day at this microzone in the two cyanobacterial mats studied. The close association, the distribution pattern of this association and preliminary physiological experiments suggest a co-metabolism of sulfur by the two-membered community. This probable new genus of purple bacteria may also grow photoheterotrophically using organic carbon excreted by the cyanobacterium. Since the chemical gradients in the entire photic zone fluctuate widely in a diurnal cycle, both types of metabolism probably take place. During the morning and afternoon, sulfide migrates up to the photic zone allowing photoautotrophic metabolism with sulfide as the electron donor. During the day the photic zone is highly oxygenated and the purple bacteria may either use oxidized species of sulfur such as elemental sulfur and thiosulfate in the photoautotrophic mode or grow photoheterotrophically using organic carbon excreted by M. chthonoplastes. The new type of filamentous purple sulfur

  18. Micro-scale in situ characterisation of the organic and mineral composition of modern, hypersaline, photosynthetic microbial mats

    NASA Astrophysics Data System (ADS)

    Gautret, P.; Ramboz, C.; de Wit, R.; Delarue, F.; Orange, F.; Sorieul, S.; Westall, F.

    2012-04-01

    Physico-chemical and biological micro-scale environmental parameters within microbial mats formed in hypersaline conditions favour the precipitation of minerals, such as carbonates. We used optical microscopy and the technique "Fluorescence Induction Relaxation » (FIRe) to differentiate the photosynthetic activity of oxygenic photosynthesisers (cyanobacteria) from anoxygenic photosynthesisers (Chloroflexus-like bacteria, CFB) in samples obtained in 2011. After this preliminary investigation, we characterised the elemental composition of the different species of microorganisms, their extracellular substances (EPS), and the minerals precipitated on their surface. This study was made in-situ by µ-PIXE using the nuclear microprobe of the AIFIRA platform (CEN Bordeaux-Gradignan ; protons of 1.5 or 3MeV). With this microprobe it is possible to map the distribution of elements occurring in quantities down to several ppm, a resolution that is particularly favourable for studying microorganisms. SEM observation of the same zones allowed us to localise exactly the microbial structures (cells, EPS) and minerals analysed by nuclear probe. We were thus able to document the differential S and P concentrations in the different microbial species, the CLB being richer in P. Note that the CLB filaments are < 1 µm in diameter. We were also able to demonstrate the anti-correlation of Ca and Mg in the minerals precipitated directly on the microorganisms and on their EPS. Thus we have shown the utility of these in situ, nano-scale methods in studying microbial structures consisting of different species with different metabolic activitie, and different functional groups on their cell walls and EPS implicated in the bioprecipitation of different kinds of minerals. Such features in ancient microbial mats could aid their interpretation and possibly the distinction between ancient oxygenic and anoxygenic mats.

  19. Physiological responses to hypersalinity correspond to nursery ground usage in two inshore shark species (Mustelus antarcticus and Galeorhinus galeus).

    PubMed

    Tunnah, Louise; MacKellar, Sara R C; Barnett, David A; MacCormack, Tyson J; Stehfest, Kilian M; Morash, Andrea J; Semmens, Jayson M; Currie, Suzanne

    2016-07-01

    Shark nurseries are susceptible to environmental fluctuations in salinity because of their shallow, coastal nature; however, the physiological impacts on resident elasmobranchs are largely unknown. Gummy sharks (Mustelus antarcticus) and school sharks (Galeorhinus galeus) use the same Tasmanian estuary as a nursery ground; however, each species has distinct distribution patterns that are coincident with changes in local environmental conditions, such as increases in salinity. We hypothesized that these differences were directly related to differential physiological tolerances to high salinity. To test this hypothesis, we exposed wild, juvenile school and gummy sharks to an environmentally relevant hypersaline (120% SW) event for 48 h. Metabolic rate decreased 20-35% in both species, and gill Na(+)/K(+)-ATPase activity was maintained in gummy sharks but decreased 37% in school sharks. We measured plasma ions (Na(+), K(+), Cl(-)) and osmolytes [urea and trimethylamine oxide (TMAO)], and observed a 33% increase in plasma Na(+) in gummy sharks with hyperosmotic exposure, while school sharks displayed a typical ureosmotic increase in plasma urea (∼20%). With elevated salinity, gill TMAO concentration increased by 42% in school sharks and by 30% in gummy sharks. Indicators of cellular stress (heat shock proteins HSP70, 90 and 110, and ubiquitin) significantly increased in gill and white muscle in both a species- and a tissue-specific manner. Overall, gummy sharks exhibited greater osmotic perturbation and ionic dysregulation and a larger cellular stress response compared with school sharks. Our findings provide physiological correlates to the observed distribution and movement of these shark species in their critical nursery grounds. PMID:27207636

  20. Three-dimensional model of the Mono Basin (California): finite element analysis of the interaction between the Hartley Spring Fault and the Mono Dike

    NASA Astrophysics Data System (ADS)

    La Marra, D.; Manconi, A.; McDonnell, A.; Battaglia, M.

    2012-12-01

    Mono Basin is a northward-trending structural depression lying immediately east of the central Sierra Nevada (California) that extends from the northern edge of Long Valley Caldera towards the center of Mono Lake. The Mono-Inyo Craters volcanic chain forms a prominent 17-km-long arcuate ridge within the Mono Basin. Recent studies have proposed that the volcanism and tectonism in this area is likely interrelated. Stratigraphic data suggest that a series of strong earthquakes occurred during the North Mono-Inyo eruption sequence of 1350 A.D. Geological data are consistent with rupture of the Hartley Springs fault during the eruption sequence. The temporal proximity of these events suggests the possibility of a causal relationship. We use the Finite Element Method (FEM) to generate a three-dimensional model of the Mono Basin and investigate the feedback mechanism between dike intrusion and slip along the Hartley Springs fault. First we combine the potential of the FEM with the Okada (1992) analytical solution for a homogeneous elastic flat half-space to validate our model. Then, to better simulate a geodynamic model of the Mono Basin, we implement more realistic dynamics that include gravity forces, vertical and lateral heterogeneities of the crust, and topography. We evaluate the distribution of local stress changes to study the influence of the Inyo dike intrusion on the Hartley Springs fault and how slip along the fault may encourage the propagation of dikes towards the surface. We employ the Coulomb stress change as a failure criterion on the Hartley Springs fault. Preliminary results indicate that slip along the Hartley Springs fault may have encouraged the intrusion of the Mono Dike.

  1. Low Bacterial Diversity and High Labile Organic Matter Concentrations in the Sediments of the Medee Deep-Sea Hypersaline Anoxic Basin

    PubMed Central

    Akoumianaki, Ioanna; Nomaki, Hidetaka; Pachiadaki, Maria; Kormas, Konstantinos Ar.; Kitazato, Hiroshi; Tokuyama, Hidekazu

    2012-01-01

    Studies in the center and margin of the Medee Basin, a Mediterranean deep-sea hypersaline anoxic basin, and at a reference site during Penelope cruise (2007), revealed the existence of a 7 m-thick halocline, with high salinity (328 psu), and high sedimentary organic carbon and biopolymer concentrations. The 194 16S rRNA sequences retrieved were grouped into 118 unique phylotypes. Pseudomonas gessardii, dominated in the center, while 33 phylotypes were detected at the margin and 73 at the reference site. The study suggested conditions hostile to bacteria in the sediments of the Medee Basin and preservation of sedimentary labile organic matter. PMID:22504432

  2. The Alkaline Diet: Is There Evidence That an Alkaline pH Diet Benefits Health?

    PubMed Central

    Schwalfenberg, Gerry K.

    2012-01-01

    This review looks at the role of an alkaline diet in health. Pubmed was searched looking for articles on pH, potential renal acid loads, bone health, muscle, growth hormone, back pain, vitamin D and chemotherapy. Many books written in the lay literature on the alkaline diet were also reviewed and evaluated in light of the published medical literature. There may be some value in considering an alkaline diet in reducing morbidity and mortality from chronic diseases and further studies are warranted in this area of medicine. PMID:22013455

  3. 21 CFR 172.856 - Propylene glycol mono- and diesters of fats and fatty acids.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Propylene glycol mono- and diesters of fats and... diesters of fats and fatty acids. Propylene glycol mono- and diesters of fats and fatty acids may be safely used in food, subject to the following prescribed conditions: (a) They are produced from edible...

  4. 21 CFR 172.856 - Propylene glycol mono- and diesters of fats and fatty acids.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Propylene glycol mono- and diesters of fats and... diesters of fats and fatty acids. Propylene glycol mono- and diesters of fats and fatty acids may be safely used in food, subject to the following prescribed conditions: (a) They are produced from edible...

  5. 21 CFR 172.856 - Propylene glycol mono- and diesters of fats and fatty acids.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Propylene glycol mono- and diesters of fats and... diesters of fats and fatty acids. Propylene glycol mono- and diesters of fats and fatty acids may be safely used in food, subject to the following prescribed conditions: (a) They are produced from edible...

  6. 21 CFR 172.856 - Propylene glycol mono- and diesters of fats and fatty acids.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Propylene glycol mono- and diesters of fats and... diesters of fats and fatty acids. Propylene glycol mono- and diesters of fats and fatty acids may be safely used in food, subject to the following prescribed conditions: (a) They are produced from edible...

  7. 40 CFR 721.10437 - Sulfonic acid, linear xylene alkylate, mono, sodium salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Sulfonic acid, linear xylene alkylate... Significant New Uses for Specific Chemical Substances § 721.10437 Sulfonic acid, linear xylene alkylate, mono... chemical substances identified generically as sulfonic acid, linear xylene alkylate, mono, sodium...

  8. 40 CFR 721.10437 - Sulfonic acid, linear xylene alkylate, mono, sodium salts (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Sulfonic acid, linear xylene alkylate... Significant New Uses for Specific Chemical Substances § 721.10437 Sulfonic acid, linear xylene alkylate, mono... chemical substances identified generically as sulfonic acid, linear xylene alkylate, mono, sodium...

  9. Synthesis and physical properties of mono-estolides with varying chain lengths

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Saturated mono-estolide methyl esters and enriched saturated mono-estolide 2-EH esters were synthesized from oleic and different saturated fatty acids under three different synthetic routes. Estolide numbers (EN), the average number of fatty acid units added to a base fatty acid, varied with synthe...

  10. 21 CFR 573.820 - Polyoxyethylene glycol (400) mono- and dioleates.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.820 Polyoxyethylene glycol (400) mono- and dioleates. The food additive polyoxyethylene glycol (400) mono- and dioleates may be safely used as an...

  11. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.800 Polyethylene glycol (400) mono- and dioleate. (a) The food additive polyethylene glycol (400) mono- and dioleate meets the following...

  12. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.800 Polyethylene glycol (400) mono- and dioleate. (a) The food additive polyethylene glycol (400) mono- and dioleate meets the following...

  13. 21 CFR 573.820 - Polyoxyethylene glycol (400) mono- and dioleates.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.820 Polyoxyethylene glycol (400) mono- and dioleates. The food additive polyoxyethylene glycol (400) mono- and dioleates may be safely used as an...

  14. 21 CFR 573.820 - Polyoxyethylene glycol (400) mono- and dioleates.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.820 Polyoxyethylene glycol (400) mono- and dioleates. The food additive polyoxyethylene glycol (400) mono- and dioleates may be safely used as an...

  15. Magnetic and gravity studies of Mono Lake, east-central, California

    USGS Publications Warehouse

    Athens, Noah D.; Ponce, David A.; Jayko, Angela S.; Miller, Matt; McEvoy, Bobby; Marcaida, Mae; Mangan, Margaret T.; Wilkinson, Stuart K.; McClain, James S.; Chuchel, Bruce A.; Denton, Kevin M.

    2014-01-01

    From August 26 to September 5, 2011, the U.S. Geological Survey (USGS) collected more than 600 line-kilometers of shipborne magnetic data on Mono Lake, 20 line-kilometers of ground magnetic data on Paoha Island, 50 gravity stations on Paoha and Negit Islands, and 28 rock samples on Paoha and Negit Islands, in east-central California. Magnetic and gravity investigations were undertaken in Mono Lake to study regional crustal structures and to aid in understanding the geologic framework, in particular regarding potential geothermal resources and volcanic hazards throughout Mono Basin. Furthermore, shipborne magnetic data illuminate local structures in the upper crust beneath Mono Lake where geologic exposure is absent. Magnetic and gravity methods, which sense contrasting physical properties of the subsurface, are ideal for studying Mono Lake. Exposed rock units surrounding Mono Lake consist mainly of Quaternary alluvium, lacustrine sediment, aeolian deposits, basalt, and Paleozoic granitic and metasedimentary rocks (Bailey, 1989). At Black Point, on the northwest shore of Mono Lake, there is a mafic cinder cone that was produced by a subaqueous eruption around 13.3 ka. Within Mono Lake there are several small dacite cinder cones and flows, forming Negit Island and part of Paoha Island, which also host deposits of Quaternary lacustrine sediments. The typical density and magnetic properties of young volcanic rocks contrast with those of the lacustrine sediment, enabling us to map their subsurface extent.

  16. Synthesis, purification, and time-dependent disposition studies of 9- or 10-mono-iodostearic acid and 9- and 10-mono-iodostearyl carnitine

    SciTech Connect

    Reed, K.W.

    1985-01-01

    The purpose of this investigation was to evaluate the potential use of radiolabeled 9- or 10-mono-iodostearyl carnitine as a perfusion and metabolic imaging agent for the heart. Radiochemical purity was achieved and determined by the use of silica gel and/or anion exchange resin chromatography. Radiochemical yields of 45-63 and 4% were obtained for the fatty acid and carnitine ester, respectively. Male albino mice were sacrificed at 2, 5, 7, 10, 15, 20, 30, and 50 minutes post-injection with either /sup 125/I 9- or 10-mono-iodostearic acid or 9- or 10-mono-iodostearyl (-) carnitine. The lungs, liver heart, kidney, spleen, pancreas, small intestine, stomach, thyroid, blood, fat, and skeletal muscle tissue were excised and assayed for levels of radioactivity in a NaI crystal well counter. The very low target-to-nontarget ratios obtained with /sup 125/I 9- or 10-mono-iodostearyl carnitine in mice strongly suggest that radioiodinated 9- or 10-mono-iodostearyl carnitine is not suitable for use as a myocardial imaging agent. However, radioiodinated 9- or 10-mono-iodostearic acid showed promise as a myocardial imaging agent and may warrant further investigation.

  17. The radiocarbon budget for Mono Lake: an unsolved mystery

    USGS Publications Warehouse

    Broecker, W.S.; Wanninkhof, R.; Mathieu, G.; Peng, T.-H.; Stine, S.; Robinson, S.; Herczeg, A.; Stuiver, M.

    1988-01-01

    Since 1957 the 14C C ratio of the dissolved inorganic carbon in Mono Lake has risen by about 60???. The magnitude of this increase is about four times larger than that expected from the invasion of bomb-produced 14C from the atmosphere. We have eliminated the following explanations: (1) measurement error, (2) an unusually high physical exchange rate for non-reactive gases, (3) inorganic enhancement of the CO2 exchange rate, and (4) biological enhancement of the CO2 exchange rate. Clandestine disposal of waste radiocarbon remains a dark-horse explanation. In the course of our investigations we have uncovered evidence for at least one episodic input of radiocarbon-free carbon to the lake over the last 1000 years. We speculate that this injection was related to a hydrothermal event resulting from sublacustrine volcanic activity. ?? 1988.

  18. Mono-Higgs detection of dark matter at the LHC

    NASA Astrophysics Data System (ADS)

    Berlin, Asher; Lin, Tongyan; Wang, Lian-Tao

    2014-06-01

    Motivated by the recent discovery of the Higgs boson, we investigate the possibility that a missing energy plus Higgs final state is the dominant signal channel for dark matter at the LHC. We consider examples of higher-dimension operators where a Higgs and dark matter pair are produced through an off-shell Z or γ, finding potential sensitivity at the LHC to cutoff scales of around a few hundred GeV. We generalize this production mechanism to a simplified model by introducing a Z' as well as a second Higgs doublet, where the pseudoscalar couples to dark matter. Resonant production of the Z' which decays to a Higgs plus invisible particles gives rise to a potential mono-Higgs signal. This may be observable at the 14 TeV LHC at low tan β and when the Z' mass is roughly in the range 600 GeV to 1.3 TeV.

  19. Aryl hydrocarbon mono-oxygenase activity in human lymphocytes

    SciTech Connect

    Griffin, G.D.; Schuresko, D.D.

    1981-06-01

    Aryl hydrocarbon mono-oxygenase (AHM), an enzyme of key importance in metabolism of xenobiotic chemicals such as polynuclear aromatic hydrocarbons (PNA), is present in human lymphocytes. Studies investing the relation of activity of AHM in human lymphocytes to parameters such as disease state, PNA exposure, in vitro mitogen stimulation, etc. have been summarized in this report. Some studies have demonstrated increased AHM activity in lymphocytes from cigarette smokers (compared to nonsmokers), and in lung cancer patients when compared to appropriate control groups. These observations are confused by extreme variability in human lymphocyte AHM activities, such variability arising from factors such as genetic variation in AHM activity, variation in in vitro culture conditions which affect AHM activity, and the problematical relationship of common AHM assays to actual PNA metabolism taking place in lymphocytes. If some of the foregoing problems can be adequately addressed, lymphocyte AHM activity could hold the promise of being a useful biomarker system for human PNA exposure.

  20. Synthesis of mono- and dideoxygenated α,α-trehalose analogs

    PubMed Central

    Lin, Fiona L.; van Halbeek, Herman; Bertozzi, Carolyn R.

    2007-01-01

    In this work we describe the synthesis and NMR characterization of four mono- and four dideoxygenated analogs of α,α-d-trehalose. The symmetrical (2,2′-, 3,3′-, 4,4′- and 6,6′-) dideoxy analogs were obtained via selective protection and subsequent radical deoxygenation of the desired hydroxyl group set. The unsymmetrical (2′-, 3′-, 4′- and 6′-) monodeoxy analogs were synthesized by desymmetrization of α,α-trehalose and subsequent deoxygenation under radical conditions. Complete assignment of all 1H and 13C resonances in the spectra of these deoxytrehaloses was achieved through the extensive use of 2D {1H,1H} and {1H,13C} correlation NMR experiments. The synthesis of these trehalose analogs sets the stage for future biochemical and NMR-based studies to probe the substrate interactions of trehalose with the recently identified mycobacterial sulfotransferase Stf0. PMID:17559818

  1. MERCURIC CHLORIDE CAPTURE BY ALKALINE SORBENTS

    EPA Science Inventory

    The paper gives results of bench-scale mechanistic studies of mercury/sorbent reactions that showed that mercuric chloride (HgC12) is readily adsorbed by alkaline sorbents, which may offers a less expensive alternative to the use of activated carbons. A laboratory-scale, fixed-b...

  2. Negative Electrode For An Alkaline Cell

    DOEpatents

    Coco, Isabelle; Cocciantelli, Jean-Michel; Villenave, Jean-Jacques

    1998-07-14

    The present invention concerns a negative electrode for an alkaline cell, comprising a current collector supporting a paste containing an electrochemically active material and a binder, characterized in that said binder is a polymer containing hydrophilic and hydrophobic groups, said polymer being selected from an acrylic homopolymer, copolymer and terpolymer, an unsaturated organic acid copolymer and an unsaturated acid anhydride copolymer.

  3. Kinetics of the alkaline hydrolysis of nitrocellulose.

    PubMed

    Christodoulatos, C; Su, T L; Koutsospyros, A

    2001-01-01

    Cellulose nitrate (nitrocellulose) is an explosive solid substance used in large quantities in various formulations of rocket and gun propellants. Safe destruction of nitrocellulose can be achieved by alkaline hydrolysis, which converts it to biodegradable products that can then be treated by conventional biological processes. The kinetics of the alkaline hydrolysis of munitions-grade nitrocellulose in sodium hydroxide solutions were investigated in completely mixed batch reactors. Experiments were conducted using solutions of alkaline strength ranging from 0.1 to 15% by mass and temperatures in the range of 30 to 90 degrees C. Regression analysis of the kinetic data revealed that alkaline hydrolysis of nitrocellulose is of the order 1.0 and 1.5 with respect to nitrocellulose and hydroxide concentration, respectively. The activation energy of the hydrolysis reaction was found to be 100.9 kJ/mol with a preexponential Arrhenius constant of 4.73 x 10(13). Nitrite and nitrate, in a 3:1 ratio, were the primary nitrogen species present in the posthydrolysis solution. The kinetic information is pertinent to the development and optimization of nitrocellulose chemical-biological treatment systems. PMID:11563378

  4. Use Alkalinity Monitoring to Optimize Bioreactor Performance.

    PubMed

    Jones, Christopher S; Kult, Keegan J

    2016-05-01

    In recent years, the agricultural community has reduced flow of nitrogen from farmed landscapes to stream networks through the use of woodchip denitrification bioreactors. Although deployment of this practice is becoming more common to treat high-nitrate water from agricultural drainage pipes, information about bioreactor management strategies is sparse. This study focuses on the use of water monitoring, and especially the use of alkalinity monitoring, in five Iowa woodchip bioreactors to provide insights into and to help manage bioreactor chemistry in ways that will produce desirable outcomes. Results reported here for the five bioreactors show average annual nitrate load reductions between 50 and 80%, which is acceptable according to established practice standards. Alkalinity data, however, imply that nitrous oxide formation may have regularly occurred in at least three of the bioreactors that are considered to be closed systems. Nitrous oxide measurements of influent and effluent water provide evidence that alkalinity may be an important indicator of bioreactor performance. Bioreactor chemistry can be managed by manipulation of water throughput in ways that produce adequate nitrate removal while preventing undesirable side effects. We conclude that (i) water should be retained for longer periods of time in bioreactors where nitrous oxide formation is indicated, (ii) measuring only nitrate and sulfate concentrations is insufficient for proper bioreactor operation, and (iii) alkalinity monitoring should be implemented into protocols for bioreactor management. PMID:27136151

  5. ISSUES WITH ALKALINE TREATMENT OF SLUDGE

    EPA Science Inventory

    This presentation begins with a discussion of the use of lime and other alkaline materials from the very earliest times to the present for killing bacteria, viruses and parasites and for controlling odors in wastewaters and sludge. It answers the question "How did EPA arrive at i...

  6. Alkaline electrochemical cells and method of making

    NASA Technical Reports Server (NTRS)

    Hoyt, H. E.; Pfluger, H. L. (Inventor)

    1970-01-01

    Equilibrated cellulose ether membranes of increased electrolytic conductivity for use as separators in concentrated alkaline electrochemical cells are investigated. The method of making such membranes by equilibration to the degree desired in an aqueous alkali solution mantained at a temperature below about 10 C is described.

  7. Collide and conquer: constraints on simplified dark matter models using mono- X collider searches

    NASA Astrophysics Data System (ADS)

    Brennan, A. J.; McDonald, M. F.; Gramling, J.; Jacques, T. D.

    2016-05-01

    The use of simplified models as a tool for interpreting dark matter collider searches has become increasingly prevalent, and while early Run II results are beginning to appear, we look to see what further information can be extracted from the Run I dataset. We consider three `standard' simplified models that couple quarks to fermionic singlet dark matter: an s-channel vector mediator with vector or axial-vector couplings, and a t-channel scalar mediator. Upper limits on the couplings are calculated and compared across three alternate channels, namely mono-jet, mono- Z (leptonic) and mono- W/Z (hadronic). The strongest limits are observed in the mono-jet channel, however the computational simplicity and absence of significant t-channel model width effects in the mono-boson channels make these a straightforward and competitive alternative. We also include a comparison with relic density and direct detection constraints.

  8. Titanium corrosion in alkaline hydrogen peroxide environments

    NASA Astrophysics Data System (ADS)

    Been, Jantje

    1998-12-01

    The corrosion of Grade 2 titanium in alkaline hydrogen peroxide environments has been studied by weight loss corrosion tests, electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR) measurements and potentiodynamic polarography. Calcium ions and wood pulp were investigated as corrosion inhibitors. In alkaline peroxide, the titanium corrosion rate increased with increasing pH, temperature, and hydrogen peroxide concentration. The corrosion controlling mechanism is thought to be the reaction of the oxide with the perhydroxyl ion. No evidence of thermodynamically stable calcium titanate was found in the surface film of test coupons exposed to calcium-inhibited alkaline peroxide solutions. Calcium inhibition is probably the result of low local alkali and peroxide concentrations at the metal surface produced by reaction of adsorbed calcium with hydrogen peroxide. It has been shown that the inhibiting effect of calcium is temporary, possibly through an effect of calcium on the chemical and/or physical stability of the surface oxide. Pulp is an effective and stable corrosion inhibitor. Raising the pulp concentration decreased the corrosion rate. The inhibiting effect of pulp may be related to the adsorption and interaction of the pulp fibers with H 2O2, thereby decreasing the peroxide concentration and rendering the solution less corrosive. The presence of both pulp and calcium led to higher corrosion rates than obtained by either one inhibitor alone. Replacement of hydrofluoric acid with alkaline peroxide for pickling of titanium was investigated. Titanium corrosion rates in alkaline peroxide exceeded those obtained in the conventional hydrofluoric acid bath. General corrosion was observed with extensive roughening of the surface giving a dull gray appearance. Preferred dissolution of certain crystallographic planes was investigated through the corrosion of a titanium single crystal. Whereas the overall effect on the corrosion rate was small

  9. ACTINIDE-ALUMINATE SPECIATION IN ALKALINE RADIOACTIVE WASTE

    EPA Science Inventory

    Highly alkaline radioactive waste tanks contain a number of transuranic species, in particular U, Np, Pu, and Am - the exact forms of which are currently unknown. Knowledge of actinide speciation under highly alkaline conditions is essential towards understanding and predicting ...

  10. A method for making an alkaline battery electrode plate

    NASA Technical Reports Server (NTRS)

    Chida, K.; Ezaki, T.

    1983-01-01

    A method is described for making an alkaline battery electrode plate where the desired active substances are filled into a nickel foam substrate. In this substrate an electrolytic oxidation reduction occurs in an alkaline solution containing lithium hydroxide.

  11. Diversity of ribulose-1,5-bisphosphate carboxylase/oxygenase large-subunit genes in the MgCl2-dominated deep hypersaline anoxic basin discovery.

    PubMed

    van der Wielen, Paul W J J

    2006-06-01

    Partial sequences of the form I (cbbL) and form II (cbbM) of the ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) large subunit genes were obtained from the brine and interface of the MgCl2-dominated deep hypersaline anoxic basin Discovery. CbbL and cbbM genes were found in both brine and interface of the Discovery Basin but were absent in the overlying seawater. The diversity of both genes in the brine and interface was low, which might caused by the extreme saline conditions in Discovery of approximately 5 M MgCl2. None of the retrieved sequences were closely related to sequences deposited in the GenBank database. A phylogenetic analysis demonstrated that the cbbL sequences were affiliated with a Thiobacillus sp. or with one of the RuBisCO genes from Hydrogenovibrio marinus. The cbbM sequences clustered with thiobacilli or formed a new group with no close relatives. The results implicate that bacteria with the potential for carbon dioxide fixation and chemoautotrophy are present in the Discovery Basin. This is the first report demonstrating that RuBisCO genes are present under hypersaline conditions of 5 M MgCl2. PMID:16734797

  12. Molecular preservation in halite- and perchlorate-rich hypersaline subsurface deposits in the Salar Grande basin (Atacama Desert, Chile): Implications for the search for molecular biomarkers on Mars

    NASA Astrophysics Data System (ADS)

    FernáNdez-Remolar, D. C.; Chong-DíAz, G.; RuíZ-Bermejo, M.; Harir, M.; Schmitt-Kopplin, P.; Tziotis, D.; Gómez-OrtíZ, D.; GarcíA-Villadangos, M.; MartíN-Redondo, M. P.; Gómez, F.; RodríGuez-Manfredi, J. A.; Moreno-Paz, M.; de Diego-Castilla, G.; EcheverríA, A.; Urtuvia, V. N.; Blanco, Y.; Rivas, L.; Izawa, M. R. M.; Banerjee, N. R.; Demergasso, C.; Parro, V.

    2013-06-01

    Similarities between the Atacama Desert (Chile) and Mars include extreme aridity, highly oxidizing chemistry, and intense ultraviolet radiation that promoted the photochemical production of perchlorates and nitrates. Concentration of these ions under hyperarid conditions led to the formation of nitrate- and perchlorate-bearing deposits in ephemeral lakes, followed by later deposition of chlorides and sulfates. At some locations, such as the Salar Grande, hypersaline deposits have remained unaltered for millions of years. We conducted a drilling campaign in deposits of the Salar to characterize the preservation state of biological molecules. A 5 m deep discontinuous core was recovered and subjected to multitechnique analysis including the antibody microarray-based biosensor LDChip300 and the SOLID (Signs Of Life Detector) instrument, complemented by geophysical, mineralogical, geochemical, and molecular analysis. We identified two units based on the mineralogy: the upper one, from the surface to ~320 cm depth characterized by a predominance of halite and anhydrite, and the lower one, from 320 to 520 cm, with a drop in halite and anhydrite and an enrichment in nitrate and perchlorate. Organic compounds including biomolecules were detected in association with the different depositional and mineralogical units, demonstrating the high capacity for molecular preservation. Hypersaline environments preserve biomolecules over geologically significant timescales; therefore, salt-bearing materials should be high-priority targets for the search for evidence of life on Mars.

  13. 40 CFR 721.1950 - 2-Butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester .

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false 2-Butenedioic acid (Z), mono(2-((1... Specific Chemical Substances § 721.1950 2-Butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester . (a... 2-butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester (PMN P-85-543) is subject...

  14. 40 CFR 721.1950 - 2-Butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester .

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false 2-Butenedioic acid (Z), mono(2-((1... Specific Chemical Substances § 721.1950 2-Butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester . (a... 2-butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester (PMN P-85-543) is subject...

  15. 40 CFR 721.1950 - 2-Butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester .

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false 2-Butenedioic acid (Z), mono(2-((1... Specific Chemical Substances § 721.1950 2-Butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester . (a... 2-butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester (PMN P-85-543) is subject...

  16. FINAL REPORT. ACTINIDE-ALUMINATE SPECIATION IN ALKALINE RADIOACTIVE WASTE

    EPA Science Inventory

    Investigation of behavior of actinides in alkaline media containing Al(III) showed that no aluminate complexes of actinides in oxidation states (III-VII) were formed in alkaline solutions. At alkaline precipitation (pH 10-14) of actinides in presence of Al(III) formation of alumi...

  17. Combined stable isotope, proteomic, metabolomics, and spatial specific analysis to track carbon flow through a hypersaline phototrophic microbial mat

    NASA Astrophysics Data System (ADS)

    Moran, J.; Cory, A.; Riha, K. M.; Huang, E. L.; Gritsenko, M. A.; Kim, Y. M.; Metz, T. O.; Lipton, M. S.

    2014-12-01

    Tracking labeled substrates through microbial mat systems can help elucidate carbon dynamics, species interactions, and niche partitioning, but the inherent microbial complexity of these systems makes them difficult to probe with single analytical techniques. Here we use a combination of different tools to track three labeled substrates through a benthic phototrophic mat from Hot Lake. Hot Lake is a hypersaline, meromictic lake located in an endorheic basin in north-central Washington which, despite extreme salinity and seasonal water temperatures (> 55 ˚C), hosts dense, phototrophic benthic microbial mats. Cyanobacteria are the dominant CO2-fixing organisms in the system and we seek to understand the spatial and metabolic controls on how the carbon initially fixed by mat cyanobacteria is transferred to associated heterotrophic populations spread throughout the mat strata. We performed ex situ incubations over a complete diel cycle with 13C labeled bicarbonate, acetate, and glucose. Traditional elemental analysis IRMS provided an estimate of bulk label uptake to total biomass and showed that both bicarbonate and acetate were incorporated only during daylight while glucose uptake was nearly constant through the cycle. Spatially resolved isotope analysis using laser ablation IRMS showed distinctive patterns between the different substrates with bicarbonate having highest uptake in the top third of the mat, acetate uptake focused near the mat's center, and glucose showing similar uptake at all mat depths. Proteomic analysis showed a longer lag in substrate conversion to protein than to biomass and a distinct spike in the number of labeled peptides in the bicarbonate incubation near the end of the diel cycle. Proteomic analysis confirmed that photosynthetic organisms showed the highest rates of label conversion to protein but heterotrophic organisms also incorporated label into their peptides. Metabolomic analysis demonstrated the high conversion of organic substrates

  18. Separation of mono- and di-PEGylate of exenatide and resolution of positional isomers of mono-PEGylates by preparative ion exchange chromatography.

    PubMed

    Nguyen, Ngoc-Thanh Thi; Lee, Jae Sun; Yun, Soi; Lee, E K

    2016-07-29

    Exenatide is a synthetic version of the 39-mer peptide of Exendin-4, which is an FDA-approved therapeutic against Type II diabetes mellitus. However, exenatide has a very short in-serum half-life and PEGylation have been performed to improve its in-serum stability. PEGylation often yields multivalent binding to non-specific residues, and the desired species should be carefully separated by chromatographies. In this study, we first devised an aqueous-phase, two-step PEGylation process. This consists of thiolation of Lys 12 and 27 residues followed by attachment of PEG-maleimide (10kD) to thiol groups. This process yields various species: mono-PEGylates with positional isomers, di-PEGylate, and other higher MW substances. A prep-grade cationic exchange chromatography (HiTrap SP) at pH 3.0 partially separated mono- and di-PEGylates based on the molar ratio of conjugated PEG and peptide and thus molecular weight of the conjugates. To further investigate the chromatographic separation of positional isomers of mono-PEGylates, we prepared two kinds of exenatide analogs by point mutation; K12C and K27C. Each analog was mono-PEGylated with very high yield (>95%). When a mixture of the two positional isomers of mono-PEGylates was applied to HiTrap SP chromatography, K12C-PEGylate and K27C-PEGylate eluted separately at 0.22M and 0.33M NaCl, respectively. When the proportions of acid and its conjugate base of the amino acid residues adjacent to the PEGylation site at pH 3.0 were analyzed, K27C-PEGylate shows stronger positive charge than K12C-PEGylate, and we propose the residence time difference between the two mono-PEGylates could be due to the charge difference. ELISA result shows that the immuno-binding activity of both analogs and their mono-PEGylates are well maintained. Furthermore, both mono-PEGylates of the analogs show higher than 50-fold improved anti-trypsin stability. We expect that mono-PEGylates of the exenatide analogs are alternatives to the conventional C40

  19. Photolysis of alkaline-earth nitrates

    NASA Astrophysics Data System (ADS)

    Kriger, L. D.; Miklin, M. B.; Dyagileva, E. P.; Anan'ev, V. A.

    2013-02-01

    Peroxynitrite and nitrite ions are the diamagnetic products of photolysis (with light at a wavelength of 253.7 nm) of alkaline-earth nitrates; the paramagnetic products and hydrogen peroxide were not found. The structural water in alkaline-earth nitrate crystals did not affect the qualitative composition of the photodecomposition products. The quantum yield of nitrite ions was 0.0012, 0.0038, 0.0078, and 0.0091 quanta-1 and that of peroxynitrite ions was 0.0070, 0.0107, 0.0286, and 0.0407 quanta-1 for Sr(NO3)2, Ba(NO3)2, Ca(NO3)2 · 4H2O, and Mg(NO3)2 · 6H2O, respectively.

  20. Alkaline earth cation extraction from acid solution

    DOEpatents

    Dietz, Mark; Horwitz, E. Philip

    2003-01-01

    An extractant medium for extracting alkaline earth cations from an aqueous acidic sample solution is described as are a method and apparatus for using the same. The separation medium is free of diluent, free-flowing and particulate, and comprises a Crown ether that is a 4,4'(5')[C.sub.4 -C.sub.8 -alkylcyclohexano]18-Crown-6 dispersed on an inert substrate material.

  1. The alkaline earth intercalates of molybdenum disulfide

    NASA Technical Reports Server (NTRS)

    Somoano, R. B.; Hadek, V.; Rembaum, A.; Samson, S.; Woollam, J. A.

    1975-01-01

    Molybdenum disulfide has been intercalated with calcium and strontium by means of the liquid ammonia technique. Chemical, X-ray, and superconductivity data are presented. The X-ray data reveal a lowering of crystal symmetry and increase of complexity of the structure upon intercalation with the alkaline earth metals. The Ca and Sr intercalates start to superconduct at 4 and 5.6 K, respectively, and show considerable anisotropy regarding the critical magnetic field.

  2. Surfactant-enhanced alkaline flooding field project

    SciTech Connect

    French, T.R.

    1991-10-01

    The Tucker sand of Helper (KS) field is a candidate for surfactant-enhanced alkaline flooding. The geology of the Helper site is typical of many DOE Class I reservoirs. The Tucker sand of Helper field was deposited in a fluvial dominated deltaic environment. Helper oil can be mobilized with either chemical system 2 or chemical system 3, as described in this report. Oil fields in the Gulf Coast region are also good candidates for surfactant-enhanced alkaline flooding. The results from laboratory tests conducted in Berea sandstone cores with oil brine from Helper (KS) field are encouraging. The crude oil is viscous and non-acidic and, yet, was mobilized by the chemical formulations described in this report. Significant amounts of the oil were mobilized under simulated reservoir conditions. The results in Berea sandstone cores were encouraging and should be verified by tests with field core. Consumption of alkali, measured with field core, was very low. Surfactant loss appeared to be acceptable. Despite the good potential for mobilization of Helper oil, certain reservoir characteristics such as low permeability, compartmentalization, and shallow depth place constraints on applications of any chemical system in the Tucker sand. These constraints are typical of many DOE Class I reservoirs. Although Hepler field is not a perfect reservoir in which to apply surfactant- enhanced alkaline flooding, Hepler oil is particularly amenable to mobilization by surfactant-enhanced alkaline systems. A field test is recommended, dependent upon final evaluation of well logs and cores from the proposed pilot area. 14 refs., 21 figs., 10 tabs.

  3. Electrochemical behaviour of mono-chloronitrobenzene as cathode material for magnesium reserve batteries

    NASA Astrophysics Data System (ADS)

    Thirunakaran, R.; Vasudevan, S.; Sivashanmugam, A.; Gopukumar, S.

    Mono-chloronitrobenzene (MCNB) is investigated as a cathode material for magnesium reserve batteries that use a magnesium anode and a 2 M magnesium perchlorate aqueous electrolyte. The composition of the conducting material (acetylene black) in the cathode mix is optimized to obtain better electrochemical performance. The reduction mechanism of mono-chloronitrobenzene is examined by means of cyclic voltammetry using a glassy carbon electrode. Discharge studies at different current drains indicate that Mg-MCNB cells exhibit the highest Coulombic efficiency (86%) at a current drain of 100 mA. The reduction of MCNB to mono-chloroaniline is irreversible and diffusion-controlled.

  4. Alkaline injection for enhanced oil recovery: a status report

    SciTech Connect

    Mayer, E.H.; Berg, R.L.; Carmichael, J.D.; Weinbrandt, R.M.

    1983-01-01

    In the past several years, there has been renewed interest in enhanced oil recovery (EOR) by alkaline injection. Alkaline solutions also are being used as preflushes in micellar/polymer projects. Several major field tests of alkaline flooding are planned, are in progress, or recently have been completed. Considerable basic research on alkaline injection has been published recently, and more is in progress. This paper summarizes known field tests and, where available, the amount of alkali injected and the performance results. Recent laboratory work, much sponsored by the U.S. DOE, and the findings are described. Alkaline flood field test plans for new projects are summarized.

  5. Alkaline flooding for enhanced oil recovery

    SciTech Connect

    Gittler, W.E.

    1983-09-01

    There are over 12 active projects of varying size using one of 3 major types of alkaline agents. These include sodium silicate, caustic soda, and soda ash. Among the largest pilots currently is the THUMS project in the Wilmington field, California. Plans called for the injection of a 4% weight concentration of sodium orthosilicate over a 60% PV. Through the first 3 yr, over 27 million bbl of chemicals have been injected. Gulf Oil is operating several alkaline floods, one of which is located off shore in the Quarantine Bay field, Louisiana. In this pilot, sodium hydroxide in a weight concentration of 5 to 12% is being injected. Belco Petroleum Corp. has reported that their pilot operating in the Isenhour Unit in Wyoming is using a .5% weight concentration of soda ash in conjunction with a polymer. Other uses for alkaline agents in chemical flooding include the use of silicate as a preflush or sacrificial agent in micellar/polymer and surfactant recovery systems. In addition, caustic has been tested in the surface-mixed caustic emulsion process while orthosilicate has been tested in a recovery method known as mobility-controlled caustic floods.

  6. Mono- and di-cationic hydrido boron compounds.

    PubMed

    Ghadwal, Rajendra S; Schürmann, Christian J; Andrada, Diego M; Frenking, Gernot

    2015-08-28

    Brønsted acid HNTf2 (Tf = SO2CF3) mediated dehydrogenative hydride abstraction from (L(1))BH3 () and (L(2))BH3 () (L(1) = IPrCH2 = 1,3-(2,6-di-isopropylphenyl)imidazol-2-methylidene (); L(2) = SIPrCH2 = 1,3-(2,6-di-isopropylphenyl)imidazolidin-2-methylidiene ()) affords thermally stable hydride bridged mono-cationic hydrido boron compounds [{(L(1))BH2}2(μ-H)](NTf2) () and [{(L(2))BH2}2(μ-H)](NTf2) (). Furthermore, hydride abstraction yields di-cationic hydrido boron compounds [{(L(1))BH}2(μ-H)2](NTf2)2 () and [{(L(2))BH}2(μ-H)2](NTf2)2 (). Unique cationic boron compounds with CH2BH2(μ-H)BH2CH2 ( and ) and CH2BH(μ-H)2BHCH2 ( and ) moieties feature a 3c-2e bond and have been fully characterized. Interesting electronic and structural features of compounds are analysed using spectroscopic, crystallographic, and computational methods. PMID:26200103

  7. Transcranial Propagation with an Ultrasonic Mono-element Focused Transducer

    NASA Astrophysics Data System (ADS)

    Iglesias, P. C.; Jiménez, N.; Konofagou, E.; Camarena, F.; Redondo, J.

    Focused Ultrasound is the only truly transient, local and non-invasive technique able to induce safe Blood-Brain Barrier Opening (BBBO), technique used in Parkinson or Alzheimer diseases research. However, the presence of the skull in the path usually affects the focus characteristics (gain, beam width, shape and maxima location). In this work, transcranial acoustic wave propagation generated by a mono-element focused transducer has been modeled using 2D and 3D FDTD methods. Skull structure of the non-human primate under test can be compared in terms of density and sound speed with polymethylmethacrylate (PMMA) films. Then, focus aberration and the phenomena that cause it are characterized, providing a better control of the beam focus using the BBBO technique. Results throw that focal axial displacements are constant with the angle of incidence for PMMA flat films. In normal incidence, a shift of 6 mm is given for axial displacement in the 2D transcranial propagation. Moreover, if the skull geometry under the action of the ultrasonic beam can be compared with the curvature radius of the transducer, displacements should be constant with angle independency, like those seeing in the homogenous flat films with the same thickness.

  8. Laser System for Livermore's Mono Energetic Gamma-Ray Source

    SciTech Connect

    Gibson, D; Albert, F; Bayramian, A; Marsh, R; Messerly, M; Ebbers, C; Hartemann, F

    2011-03-14

    A Mono-energetic Gamma-ray (MEGa-ray) source, based on Compton scattering of a high-intensity laser beam off a highly relativistic electron beam, requires highly specialized laser systems. To minimize the bandwidth of the {gamma}-ray beam, the scattering laser must have minimal bandwidth, but also match the electron beam depth of focus in length. This requires a {approx}1 J, 10 ps, fourier-transform-limited laser system. Also required is a high-brightness electron beam, best provided by a photoinjector. This electron source requires a second laser system with stringent requirements on the beam including flat transverse and longitudinal profiles and fast rise times. Furthermore, these systems must be synchronized to each other with ps-scale accuracy. Using a novel hyper-dispersion compressor configuration and advanced fiber amplifiers and diode-pumped Nd:YAG amplifiers, we have designed laser systems that meet these challenges for the X-band photoinjector and Compton-scattering source being built at Lawrence Livermore National Laboratory.

  9. On the mono-exponential fitting of phosphorescence decays

    NASA Astrophysics Data System (ADS)

    Fuhrmann, N.; Brübach, J.; Dreizler, A.

    2014-08-01

    Several methods for mono-exponential fitting of decay curves are presented and compared among each other in terms of precision, accuracy and computational time. Simulated noisy data sets are generated and evaluated in order to determine the main contributors to a loss in performance. The influence of the temporal discretization of the decay curve on the precision of the fitting methods is discussed. Correlations between the background offset and the decay time are analyzed. Variations of the signal-to-noise ratio are shown, allowing for evaluation of systematic errors and precision in the presence of noise. Finally, the algorithms are applied to experimental data, and the computational efforts for the different algorithms are compared. The results of this latter investigation confirm the conclusions drawn from the simulated data and the following conclusions are drawn: The frequently applied method of performing a linear regression to the logarithm of a background-corrected decay showed systematic errors in the presence of noise. Best results in terms of precision and accuracy were obtained by a nonlinear least-squares approximation and a method denoted as the linear regression of the sum. Additionally, this latter method required the lowest computational time and is finally recommended for determining decay times from experimental data.

  10. Mono-THF ring annonaceous acetogenins from Annona squamosa.

    PubMed

    Hopp, D C; Alali, F Q; Gu, Z M; McLaughlin, J L

    1998-03-01

    Continuing work on the bark of Annona squamosa Rich. (Annonaceae), directed by the brine shrimp lethality test (BST), has resulted in the isolation of three new Annonaceous acetogenins, 4-deoxyannoreticuin, cis-4-deoxyannoreticuin, and (2,4-cis and trans)-squamoxinone. The first two are additional examples of acetogenins isolated from this plant species which contain the unusual feature of an oxygen functionality at the C-9 position. They have a hydroxylated mono-THF ring with respective threo/trans/threo and threo/cis/threo relative stereochemistries. The latter compound is a ketolactone mixture which has the same relative stereochemistry around the THF ring and the same spatial relationship between the THF ring and the hydroxyl group along the aliphatic chain as 4-deoxyannoreticuin, but is two methylene units longer. Additionally, the isolated hydroxyl group is at C-11, while the THF ring starts at C-17, instead of at C-9 and C-15, respectively, as for the first two compounds. All three compounds showed moderate, but significant, cytotoxicities against a panel of six human tumor cell lines with (2,4 cis and trans)-squamoxinone showing promising selectivity against the pancreatic cell line (PACA-2). PMID:9542173

  11. Collaborative study on determination of mono methylmercury in seafood.

    PubMed

    Valdersnes, Stig; Fecher, Peter; Maage, Amund; Julshamn, Kaare

    2016-03-01

    Eight laboratories participated in an inter-laboratory method-performance (collaborative) study of a method for the determination of mono methylmercury (MMHg) in foodstuffs of marine origin by gas chromatography inductively coupled plasma isotope dilution mass spectrometry (GC-ICP-IDMS) after dissolution, derivatisation and extraction of the species. The method was tested on seven seafood products covering both a wide concentration range and variations in the MMHg concentrations as well as matrix compositions. The samples were mussel tissue, squid muscle, crab claw meat, whale meat, cod muscle, Greenland halibut muscle and dogfish liver (NRCC DOLT-4), with MMHg concentrations ranging from 0.035 to 3.58mg/kg (as Hg) dry weight. Repeatability relative standard deviations (RSDr) for MMHg ranged from 2.1% to 8.7%. Reproducibility relative standard deviations (RSDR) ranged from 5.8% to 42%. All samples showed HorRat value below 1.0, except for the sample with the lowest MMHg content, mussel tissue, with a HorRat value of 1.6. PMID:26471575

  12. Fetotoxic effects of mono-2-ethylhexyl phthalate (MEHP) in mice.

    PubMed Central

    Tomita, I; Nakamura, Y; Yagi, Y; Tutikawa, K

    1986-01-01

    Mono(2-ethylhexyl) phthalate (MEHP), one of the main metabolites of di(2-ethylhexyl) phthalate (DEHP), exerted embryo/fetotoxic effects similar to those of DEHP at lower doses. Oral administration of MEHP (1 mL/kg) to the mice of 8 days gestation resulted in less than 32% of live fetuses, all of which were deformed. When DEHP (10 mL/kg) was given to the pregnant mice of 8 days gestation, approximately 0.03% and 0.003% of the administered dose was found in fetuses as DEHP and MEHP, respectively, after 12 hr. The presence of the MEHP in fetuses is probably due to the transplacental crossing of the MEHP formed in the maternal body, since the fetuses of mice up to day 9 of pregnancy showed no hydrolytic activity of DEHP to MEHP. Crossing of MEHP through the placenta was proven by an experiment in which MEHP was administered in pregnant mice. A single injection of MEHP (25 or 50 mg/kg), but not DEHP (500 mg/kg) into pregnant mice, induced a significantly high incidence of somatic mutations in the coat hair of offspring of mice (KYG, female X PW, male; C57BL/6Crj, female X PW, male). All these data suggest that MEHP could be responsible for the embryotoxic/fetotoxic effects observed with DEHP. PMID:3709449

  13. Glass liquid glass reentrance in mono-component colloidal dispersions

    NASA Astrophysics Data System (ADS)

    Ramírez-González, P. E.; Vizcarra-Rendón, A.; Guevara-Rodríguez, F. de J.; Medina-Noyola, M.

    2008-05-01

    The self-consistent generalized Langevin equation (SCGLE) theory of colloid dynamics is employed to describe the ergodic-non-ergodic transition in model mono-disperse colloidal dispersions whose particles interact through hard-sphere plus short-ranged attractive forces. The ergodic-non-ergodic phase diagram in the temperature-concentration state space is determined for the hard-sphere plus attractive Yukawa model within the mean spherical approximation for the static structure factor by solving a remarkably simple equation for the localization length of the colloidal particles. Finite real values of this property signals non-ergodicity and determines the non-ergodic parameters f(k) and fs(k). The resulting phase diagram for this system, which involves the existence of reentrant (repulsive and attractive) glass states, is compared with the corresponding prediction of mode coupling theory. Although both theories coincide in the general features of this phase diagram, there are also clear qualitative differences. One of the most relevant is the SCGLE prediction that the ergodic-attractive glass transition does not preempt the gas-liquid phase transition, but always intersects the corresponding spinodal curve on its high-concentration side. We also calculate the ergodic-non-ergodic phase diagram for the sticky hard-sphere model to illustrate the dependence of the predicted SCGLE dynamic phase diagram on the choice of one important constituent element of the SCGLE theory.

  14. Neutrino Mass Measurement Using a Directed Mono-Energetic Beam

    NASA Astrophysics Data System (ADS)

    Tsifrinovich, Vladimir; Folan, Lorcan

    2015-04-01

    It was shown that a directed mono-energetic neutrino beam can be generated by electron capture beta-decay in a sample with a strong hyperfine field at the radioactive nuclei. We study the conditions required to measure the neutrino rest mass using the recoil force produced by a directed neutrino beam. We consider the displacement of an atomic force microscope cantilever due to such a recoil force. We find the change in the cantilever displacement associated with the non-zero neutrino mass, as a function of nuclear half-life T1 / 2, cantilever spring constant, and temperature. We consider the opportunity to increase the sensitivity of the neutrino mass measurement using averaging of the measurement signal. We show that the optimal time for the signal accumulation is, approximately, 1.8T1 / 2. We compute the optimal signal-to-noise ratio for 119Sb nuclei decaying to 119Sn with a decrease in the nuclear spin from I = 5/2 to I = 3/2, and T1 / 2 = 38.2 hours. Finally, we present the parameters values required for detection of sub-eV neutrino rest mass, and estimate the angular distribution of neutrino radiation as a function of temperature.

  15. Mono- and bimetallic zwitterionic chromium(0) and tungsten(0) allenyls.

    PubMed

    Giner, Elena A; Santiago, Alicia; Gómez-Gallego, Mar; Ramírez de Arellano, Carmen; Poulten, Rebecca C; Whittlesey, Michael K; Sierra, Miguel A

    2015-06-01

    A series of stable chiral (racemic), formally neutral, zwitterionic mono- and bimetallic M(CO)5[C(OEt)═C═CR(NHC)] (M = Cr, W) σ-allenyls are ready available by the addition of N-heterocyclic carbenes (NHCs) to Cr(0) and W(0) alkynyl Fischer carbene complexes. Different classes of NHCs, (e.g., 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene, 1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene, and their six- and seven-membered analogues and 1,3-bis(dimethyl)imidazol-2-ylidene) were employed as nucleophiles in these C-C bond-forming reactions yielding the novel complexes in essentially quantitative yields. A systematic experimental and computational study of the electronic properties of the Cr- and W-allenyls shows that their UV-vis spectra are directly influenced by the structure of the heterocyclic moiety derived from the NHC (ring size, substituents on the N atoms) and by the nature of the metal fragment (Cr/W). The electron-releasing nature of these complexes allows them to participate in electron-transfer reactions in the ground state, leading to a type of charged α,β-unsaturated Fischer carbenes that incorporate an NHC fragment in their structure. PMID:25952749

  16. Adding Mono- and Multivalent Ions to Lyotropic Chromonic Liquid Crystals

    NASA Astrophysics Data System (ADS)

    Tortora, Luana; Park, Heung-Shik; Antion, Kelly; Woolwerton, Chris; Finotello, Daniele; Lavrentovich, Oleg

    2006-03-01

    Lyotropic Chromonic Liquid Crystals (LCLCs) are a distinct class of liquid crystals formed in aqueous solutions by molecules with rigid polyaromatic cores and ionic groups at the periphery [1-4]. The phase diagrams of these materials should depend on entropic factors (as in the Onsager model) and electrostatic interactions. Using optical polarizing microscopy, we studied the effects of mono- and multivalent ions on the phase diagrams of Blue 27 [3] and Sunset Yellow [2]. The monovalent ions change the temperatures of phase transitions, as described in [4], while the effect of multivalent ions is more dramatic and, in addition to the changed temperatures of phase transitions by tens of degrees, it often involves condensation of LCLC aggregates into domains with birefringence much higher than that in a normal nematic phase. Work supported by OBR B-7844. [1]J. Lydon, Current Opin. Colloid & Interface Sci. 3, 458 (1998);8, 480-489 (2004); [2]V. R. Horowitz, L. A. Janowitz, A. L. Modic, P. J. Heiney, and P. J. Collings, 2005, Phys. Rew. E 72, 041710; [3]Yu. A. Nastishin, H. Liu, T. Schneider, T., V. Nazarenko, R. Vasyuta, S. V. Shiyanovskii, and O. D. Lavrentovich, 2005, Phys. Rev. E 72, 041711; [4]A.F. Kostko, B. H. Cipriano, O. A. Pinchuk, L. Ziserman, M. A. Anisimov, D. Danino, and S. R. Raghavan. J. Phys. Chem. B 109, 19126-19133 (2005)

  17. The fate of added alkalinity in model scenarios of ocean alkalinization

    NASA Astrophysics Data System (ADS)

    Ferrer González, Miriam; Ilyina, Tatiana

    2014-05-01

    The deliberate large-scale manipulation of the Earth's climate (geo-engineering) has been proposed to mitigate climate change and ocean acidification. Whilst the mitigation potential of these technologies could sound promising, they may also pose many environmental risks. Our research aims at exploring the ocean-based carbon dioxide removal method of alkalinity enhancement. Its mitigation potential to reduce atmospheric CO2 and counteract the consequences of ocean acidification, risks and unintended consequences are studied. In order to tackle these questions, different scenarios are implemented in the state-of-the-art Earth system model of the Max Planck Institute for Meteorology. The model configuration is based on the 5th phase of the coupled model intercomparison project following a high CO2 future climate change scenario RCP8.5 (in which radiative forcing rises to 8.5 W/m² in 2100). Two different scenarios are performed where the alkalinity is artificially added globally uniformly in the upper ocean. In the first scenario, alkalinity is increased as a pulse by doubling natural values of the first 12 meters. In the second scenario we add alkalinity into the same ocean layer such that the atmospheric CO2 concentration is reduced from RCP8.5 to RCP4.5 levels (with the radiative forcing of 4.5 W/m² in 2100). We investigate the fate of the added alkalinity in these two scenarios and compare the differences in alkalinity budgets. In order to increase oceanic CO2 uptake from the atmosphere, enhanced alkalinity has to stay in the upper ocean. Once the alkalinity is added, it will become part of the biogeochemical cycles and it will be distributed with the ocean currents. Therefore, we are particularly interested in the residence time of the added alkalinity at the surface. Variations in CO2 partial pressure, seawater pH and saturation state of carbonate minerals produced in the implemented scenarios will be presented. Collateral changes in ocean biogeochemistry and

  18. DECHLORINATION ACTIVITY (CROSS-ACCLIMATION) OF FRESHWATER SEDIMENTS ADAPTED TO MONO- AND DI-CHLOROPHENOLS

    EPA Science Inventory

    The reductive dechlorination of chlorophenols (CPs) in sediment slurries (10% solids) adapted to dechlorinate mono- and di-CPs (DCP) was investigated to define the regiospecificity of the dechlorination reaction. nadapted sediment slurries amended with various ortho-substituted C...

  19. Geothermal systems of the Mono Basin-Long Valley region, eastern California and western Nevada

    SciTech Connect

    Higgins, C.T.; Flynn, T.; Chapman, R.H.; Trexler, D.T.; Chase, G.R.; Bacon, C.F.; Ghusn, G. Jr.

    1985-01-01

    The region that includes Mono Basin, Long Valley, the Bridgeport-Bodie Hills area, and Aurora, in eastern California and western Nevada was studied to determine the possible causes and interactions of the geothermal anomalies in the Mono Basin-Long Valley region as a whole. A special goal of the study was to locate possible shallow bodies of magma and to determine their influence on the hydrothermal systems in the region. (ACR)

  20. Roles of mono-ubiquitinated Smad4 in the formation of Smad transcriptional complexes

    SciTech Connect

    Wang Bei; Suzuki, Hiroyuki Kato, Mitsuyasu

    2008-11-14

    TGF-{beta} activates receptor-regulated Smad (R-Smad) through phosphorylation by type I receptors. Activated R-Smad binds to Smad4 and the complex translocates into the nucleus and stimulates the transcription of target genes through association with co-activators including p300. It is not clear, however, how activated Smad complexes are removed from target genes. In this study, we show that TGF-{beta} enhances the mono-ubiquitination of Smad4. Smad4 mono-ubiquitination was promoted by p300 and suppressed by the c-Ski co-repressor. Smad4 mono-ubiquitination disrupted the interaction with Smad2 in the presence of constitutively active TGF-{beta} type I receptor. Furthermore, mono-ubiquitinated Smad4 was not found in DNA-binding Smad complexes. A Smad4-Ubiquitin fusion protein, which mimics mono-ubiquitinated Smad4, enhanced localization to the cytoplasm. These results suggest that mono-ubiquitination of Smad4 occurs in the transcriptional activator complex and facilitates the turnover of Smad complexes at target genes.

  1. Good quality blastocyst from non-/mono-pronuclear zygote may be used for transfer during IVF.

    PubMed

    Yin, Bao-Li; Hao, Hao-Ying; Zhang, Ya-Nan; Wei, Duo; Zhang, Cui-Lian

    2016-04-01

    Although healthy infants have developed from non- and mono-pronuclear zygotes, the transfer of embryos from non- and mono-pronuclear zygotes is not recommended because there are no proper selection criteria. In the present study, we discuss how to select non- and mono-pronuclear embryos with the highest developmental potential at 19-20 hours post-insemination. We found that the percentage of blastocysts with normal chromosome constitution in non-pronuclear zygotes was slightly higher than in mono-pronuclear zygotes. Non- and mono-pronuclear embryos that were at the 4-cell stage on D2 and/or at the 6- to 8-cell stage on D3 had higher incidence rates of blastocysts with normal chromosome constitutions. We also found higher incidences of blastocysts with normal chromosome constitution on D6 than on D5. The results suggest that if high quality non- and mono-pronuclear zygotes develop to the 4-cell stage on D2 and the 6-to 8- cell stages on D3, along with high quality D6 blastocysts, the incidence of blastocysts with normal chromosome constitution is higher. PMID:26901373

  2. Determination of biological and physicochemical parameters of Artemia franciscana strains in hypersaline environments for aquaculture in the Colombian Caribbean

    PubMed Central

    Camargo, William N; Durán, Gabriel C; Rada, Orlando C; Hernández, Licet C; Linero, Juan-Carlos G; Muelle, Igor M; Sorgeloos, Patrick

    2005-01-01

    Background Artemia (Crustacea, Anostraca), also known as brine shrimp, are typical inhabitants of extreme environments. These hypersaline environments vary considerably in their physicochemical composition, and even their climatic conditions and elevation. Several thalassohaline (marine) environments along the Colombian Caribbean coast were surveyed in order to contribute to the knowledge of brine shrimp biotopes in South America by determining some vital biological and physicochemical parameters for Artemia survival. Additionally, cyst quality tests, biometrical and essential fatty acids analysis were performed to evaluate the economic viability of some of these strains for the aquaculture industry. Results In addition to the three locations (Galerazamba, Manaure, and Pozos Colorados) reported in the literature three decades ago in the Colombian Caribbean, six new locations were registered (Salina Cero, Kangaru, Tayrona, Bahía Hondita, Warrego and Pusheo). All habitats sampled showed that chloride was the prevailing anion, as expected, because of their thalassohaline origin. There were significant differences in cyst diameter grouping strains in the following manner according to this parameter: 1) San Francisco Bay (SFB-Control, USA), 2) Galerazamba and Tayrona, 3) Kangarú, 4) Manaure, and 5) Salina Cero and Pozos Colorados. Chorion thickness values were smaller in Tayrona, followed by Salina Cero, Galerazamba, Manaure, SFB, Kangarú and Pozos Colorados. There were significant differences in naupliar size, grouping strains as follows (smallest to largest): 1) Galerazamba, 2) Manaure, 3) SFB, Kangarú, and Salina Cero, 4) Pozos Colorados, and 5) Tayrona. Overall, cyst quality analysis conducted on samples from Manaure, Galerazamba, and Salina Cero revealed that all sites exhibited a relatively high number of cysts.g-1. Essential fatty acids (EFA) analysis performed on nauplii from cyst samples from Manaure, Galerazamba, Salina Cero and Tayrona revealed that cysts

  3. Discovery and industrial applications of lytic polysaccharide mono-oxygenases.

    PubMed

    Johansen, Katja S

    2016-02-01

    The recent discovery of copper-dependent lytic polysaccharide mono-oxygenases (LPMOs) has opened up a vast area of research covering several fields of application. The biotech company Novozymes A/S holds patents on the use of these enzymes for the conversion of steam-pre-treated plant residues such as straw to free sugars. These patents predate the correct classification of LPMOs and the striking synergistic effect of fungal LPMOs when combined with canonical cellulases was discovered when fractions of fungal secretomes were evaluated in industrially relevant enzyme performance assays. Today, LPMOs are a central component in the Cellic CTec enzyme products which are used in several large-scale plants for the industrial production of lignocellulosic ethanol. LPMOs are characterized by an N-terminal histidine residue which, together with an internal histidine and a tyrosine residue, co-ordinates a single copper atom in a so-called histidine brace. The mechanism by which oxygen binds to the reduced copper atom has been reported and the general mechanism of copper-oxygen-mediated activation of carbon is being investigated in the light of these discoveries. LPMOs are widespread in both the fungal and the bacterial kingdoms, although the range of action of these enzymes remains to be elucidated. However, based on the high abundance of LPMOs expressed by microbes involved in the decomposition of organic matter, the importance of LPMOs in the natural carbon-cycle is predicted to be significant. In addition, it has been suggested that LPMOs play a role in the pathology of infectious diseases such as cholera and to thus be relevant in the field of medicine. PMID:26862199

  4. Coaxial Mono-Energetic Gamma Generator for Active Interrogation

    NASA Astrophysics Data System (ADS)

    Ludewigt, B. A.; Antolak, A. J.; Henestroza, E.; Kwan, J. W.; Leitner, M.; Leung, K.-N.; Waldron, W.; Wilde, S.

    2009-03-01

    Compact mono-energetic photon sources are sought for active interrogation systems to detect shielded special nuclear materials in, for example, cargo containers, trucks and other vehicles. A prototype gamma interrogation source has been designed and built that utilizes the 11B(p,γ)12C reaction to produce 12 MeV gamma-rays which are near the peak of the photofission cross section. In particular, the 11B(p,γ)12C resonance at 163 kV allows the production of gammas at low proton acceleration voltages, thus keeping the design of a gamma generator comparatively small and simple. A coaxial design has been adopted with a toroidal-shaped plasma chamber surrounding a cylindrical gamma production target. The plasma discharge is driven by a 2 MHz rf-power supply (capable up to 50 kW) using a circular rf-antenna. Permanent magnets embedded in the walls of the plasma chamber generate a multi-cusp field that confines the plasma and allows higher plasma densities and lower gas pressures. About 100 proton beamlets are extracted through a slotted plasma electrode towards the target at the center of the device that is at a negative 180 kV. The target consists of LaB6 tiles that are brazed to a water-cooled cylindrical structure. The generator is designed to operate at 500 Hz with 20 μs long pulses, and a 1% duty factor by pulsing the ion source rf-power. A first-generation coaxial gamma source has been built for low duty factor experiments and testing.

  5. Coaxial Mono-Energetic Gamma Generator for Active Interrogation

    SciTech Connect

    Ludewigt, Bernhard A.; Antolak, A.J.; Henestroza, E.; Leitner, M.; Leung, K.-N.; Waldron, W.; Wilde, S.; Kwan, J.W.

    2008-08-01

    Compact mono-energetic photon sources are sought for active interrogation systems to detect shielded special nuclear materials in, for example, cargo containers, trucks and other vehicles. A prototype gamma interrogation source has been designed and built that utilizes the 11B(p,gamma)12C reaction to produce 12 MeV gamma-rays which are near the peak of the photofission cross section. In particular, the 11B(p,gamma)12C resonance at 163 kV allows the production of gammas at low proton acceleration voltages, thus keeping the design of a gamma generator comparatively small and simple. A coaxial design has been adopted with a toroidal-shaped plasma chamber surrounding a cylindrical gamma production target. The plasma discharge is driven by a 2 MHz rf-power supply (capable up to 50 kW) using a circular rf-antenna. Permanent magnets embedded in the walls of the plasma chamber generate a multi-cusp field that confines the plasma and allows higher plasma densities and lower gas pressures. About 100 proton beamlets are extracted through a slotted plasma electrode towards the target at the center of the device that is at a negative 180 kV. The target consists of LaB6 tiles that are brazed to a water-cooled cylindrical structure. The generator is designed to operate at 500 Hz with 20 mu s long pulses, and a 1percent duty factor by pulsing the ion source rf-power. A first-generation coaxial gamma source has been built for low duty factor experiments and testing.

  6. Coaxial Mono-Energetic Gamma Generator for Active Interrogation

    SciTech Connect

    Ludewigt, B. A.; Henestroza, E.; Kwan, J. W.; Leitner, M.; Leung, K.-N.; Waldron, W.; Wilde, S.; Antolak, A. J.

    2009-03-10

    Compact mono-energetic photon sources are sought for active interrogation systems to detect shielded special nuclear materials in, for example, cargo containers, trucks and other vehicles. A prototype gamma interrogation source has been designed and built that utilizes the {sup 11}B(p,{gamma}){sup 12}C reaction to produce 12 MeV gamma-rays which are near the peak of the photofission cross section. In particular, the {sup 11}B(p,{gamma}){sup 12}C resonance at 163 kV allows the production of gammas at low proton acceleration voltages, thus keeping the design of a gamma generator comparatively small and simple. A coaxial design has been adopted with a toroidal-shaped plasma chamber surrounding a cylindrical gamma production target. The plasma discharge is driven by a 2 MHz rf-power supply (capable up to 50 kW) using a circular rf-antenna. Permanent magnets embedded in the walls of the plasma chamber generate a multi-cusp field that confines the plasma and allows higher plasma densities and lower gas pressures. About 100 proton beamlets are extracted through a slotted plasma electrode towards the target at the center of the device that is at a negative 180 kV. The target consists of LaB{sub 6} tiles that are brazed to a water-cooled cylindrical structure. The generator is designed to operate at 500 Hz with 20 {mu}s long pulses, and a 1% duty factor by pulsing the ion source rf-power. A first-generation coaxial gamma source has been built for low duty factor experiments and testing.

  7. Mono- and multistatic polarimetric sparse aperture 3D SAR imaging

    NASA Astrophysics Data System (ADS)

    DeGraaf, Stuart; Twigg, Charles; Phillips, Louis

    2008-04-01

    SAR imaging at low center frequencies (UHF and L-band) offers advantages over imaging at more conventional (X-band) frequencies, including foliage penetration for target detection and scene segmentation based on polarimetric coherency. However, bandwidths typically available at these center frequencies are small, affording poor resolution. By exploiting extreme spatial diversity (partial hemispheric k-space coverage) and nonlinear bandwidth extrapolation/interpolation methods such as Least-Squares SuperResolution (LSSR) and Least-Squares CLEAN (LSCLEAN), one can achieve resolutions that are commensurate with the carrier frequency (λ/4) rather than the bandwidth (c/2B). Furthermore, extreme angle diversity affords complete coverage of a target's backscatter, and a correspondingly more literal image. To realize these benefits, however, one must image the scene in 3-D; otherwise layover-induced misregistration compromises the coherent summation that yields improved resolution. Practically, one is limited to very sparse elevation apertures, i.e. a small number of circular passes. Here we demonstrate that both LSSR and LSCLEAN can reduce considerably the sidelobe and alias artifacts caused by these sparse elevation apertures. Further, we illustrate how a hypothetical multi-static geometry consisting of six vertical real-aperture receive apertures, combined with a single circular transmit aperture provide effective, though sparse and unusual, 3-D k-space support. Forward scattering captured by this geometry reveals horizontal scattering surfaces that are missed in monostatic backscattering geometries. This paper illustrates results based on LucernHammer UHF and L-band mono- and multi-static simulations of a backhoe.

  8. OVERVIEW OF MONO-ENERGETIC GAMMA-RAY SOURCES & APPLICATIONS

    SciTech Connect

    Hartemann, F V; Albert, F; Anderson, G G; Anderson, S G; Bayramian, A J; Betts, S M; Chu, T S; Cross, R R; Ebbers, C A; Fisher, S E; Gibson, D J; Ladran, A S; Marsh, R A; Messerly, M J; O'Neill, K L; Semenov, V A; Shverdin, M Y; Siders, C W; McNabb, D P; Barty, C P; Vlieks, A E; Jongewaard, E N; Tantawi, S G; Raubenheimer, T O

    2010-05-18

    Recent progress in accelerator physics and laser technology have enabled the development of a new class of tunable gamma-ray light sources based on Compton scattering between a high-brightness, relativistic electron beam and a high intensity laser pulse produced via chirped-pulse amplification (CPA). A precision, tunable Mono-Energetic Gamma-ray (MEGa-ray) source driven by a compact, high-gradient X-band linac is currently under development and construction at LLNL. High-brightness, relativistic electron bunches produced by an X-band linac designed in collaboration with SLAC NAL will interact with a Joule-class, 10 ps, diode-pumped CPA laser pulse to generate tunable {gamma}-rays in the 0.5-2.5 MeV photon energy range via Compton scattering. This MEGa-ray source will be used to excite nuclear resonance fluorescence in various isotopes. Applications include homeland security, stockpile science and surveillance, nuclear fuel assay, and waste imaging and assay. The source design, key parameters, and current status are presented, along with important applications, including nuclear resonance fluorescence. In conclusion, we have optimized the design of a high brightness Compton scattering gamma-ray source, specifically designed for NRF applications. Two different parameters sets have been considered: one where the number of photons scattered in a single shot reaches approximately 7.5 x 10{sup 8}, with a focal spot size around 8 {micro}m; in the second set, the spectral brightness is optimized by using a 20 {micro}m spot size, with 0.2% relative bandwidth.

  9. X-ray microtomography characterization of carbonate microbialites from a hypersaline coastal lagoon in the Rio de Janeiro State-Brazil

    NASA Astrophysics Data System (ADS)

    Machado, A. S.; Dal Bó, P. F. F.; Lima, I.; Borghi, L.; Lopes, R.

    2015-06-01

    The objective of the present study is to apply the micro-CT technique to assess recent microbialite samples from a hypersaline coastal lagoon in the Rio de Janeiro State. The study comprises structural assessment, mineralogical characterization and porosity distribution of each sample. Micro-CT is increasingly present in geological reservoir analyses, and has advantages over other laboratory techniques since it is non-invasive and allows 2D/3D visualization of inner structures without previous preparation method, such as slabbing, polishing, thinning or impregnation. This technique renders structural analyses which can be spatially resolved to a scale of micrometers. Results show that micro-CT technique is also adequate for the characterization of carbonate microbialites, providing excellent high resolution 3D images, that enabled to distinguish different mineralogies and porosity distribution beyond it is inner structure.

  10. Origin of mafic and ultramafic cumulates from the Ditrău Alkaline Massif, Romania

    NASA Astrophysics Data System (ADS)

    Pál-Molnár, Elemér; Batki, Anikó; Almási, Enikő; Kiss, Balázs; Upton, Brian G. J.; Markl, Gregor; Odling, Nicholas; Harangi, Szabolcs

    2015-12-01

    Mafic-ultramafic cumulates enclosed in gabbroic-dioritic rocks form part of the Mesozoic Ditrău Alkaline Massif in the Eastern Carpathians, Romania. The poikilitic olivine- and pyroxene-rich and nearly mono mineralic hornblendite rocks display typical cumulate textures with early crystallised olivine (Fo75-73), diopside and augite. In the early stages of their genesis the amphibole was intercumulus whilst in later stages it acquired cumulus status as the fractionating magma evolved. Using major and trace element compositions of minerals and whole-rock samples the origin of these cumulates is determined and the parental magma composition and depth of emplacement are calculated. Cumulus clinopyroxene has more primitive composition than intercumulus amphibole suggesting closed system fractionation for the evolution of poikilitic olivine- and pyroxene-rich cumulates. The evolution of the amphibole-rich mesocumulates is more clearly the result of closed system crystallisation dominated by the precipitation of clinopyroxene and amphibole cumulus crystals. Lamprophyre dykes of the Ditrău Alkaline Massif are proposed to reflect multiple basanitic parental magma batches from which the cumulus olivine and clinopyroxene crystallised. Relative to these dykes the calculated equilibrium melts for intercumulus amphibole in the cumulates was more primitive whilst that for the cumulus amphibole was more evolved. The calculated crystallisation temperature and pressure of ~ 1000-1050 °C and ~ 0.7 GPa, based on the composition of the amphiboles, indicate crystallisation at lower crustal depths. Rare earth element compositions are consistent with an intra-plate tectonic setting.

  11. Denitrification in a hypersaline lake-aquifer system (Pétrola Basin, Central Spain): the role of recent organic matter and Cretaceous organic rich sediments.

    PubMed

    Gómez-Alday, J J; Carrey, R; Valiente, N; Otero, N; Soler, A; Ayora, C; Sanz, D; Muñoz-Martín, A; Castaño, S; Recio, C; Carnicero, A; Cortijo, A

    2014-11-01

    Agricultural regions in semi-arid to arid climates with associated saline wetlands are one of the most vulnerable environments to nitrate pollution. The Pétrola Basin was declared vulnerable to NO3(-) pollution by the Regional Government in 1998, and the hypersaline lake was classified as a heavily modified body of water. The study assessed groundwater NO3(-) through the use of multi-isotopic tracers (δ(15)N, δ(34)S, δ(13)C, δ(18)O) coupled to hydrochemistry in the aquifer connected to the eutrophic lake. Hydrogeologically, the basin shows two main flow components: regional groundwater flow from recharge areas (Zone 1) to the lake (Zone 2), and a density-driven flow from surface water to the underlying aquifer (Zone 3). In Zones 1 and 2, δ(15)NNO3 and δ(18)ONO3 suggest that NO3(-) from slightly volatilized ammonium synthetic fertilizers is only partially denitrified. The natural attenuation of NO3(-) can occur by heterotrophic reactions. However, autotrophic reactions cannot be ruled out. In Zone 3, the freshwater-saltwater interface (down to 12-16 m below the ground surface) is a reactive zone for NO3(-) attenuation. Tritium data suggest that the absence of NO3(-) in the deepest zones of the aquifer under the lake can be attributed to a regional groundwater flow with long residence time. In hypersaline lakes the geometry of the density-driven flow can play an important role in the transport of chemical species that can be related to denitrification processes. PMID:25169874

  12. Ribulose-1,5-bisphosphate carboxylase/oxygenase genes as a functional marker for chemolithoautotrophic halophilic sulfur-oxidizing bacteria in hypersaline habitats.

    PubMed

    Tourova, Tatjana P; Kovaleva, Olga L; Sorokin, Dimitry Yu; Muyzer, Gerard

    2010-07-01

    The presence and diversity of the cbb genes encoding the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) (a key enzyme of the Calvin-Benson cycle of autotrophic CO(2) assimilation) were investigated in pure cultures of seven genera of halophilic chemolithoautotrophic sulfur-oxidizing bacteria (SOB) and in sediments from a hypersaline lake in which such bacteria have been recently discovered. All of the halophilic SOB strains (with the exception of Thiohalomonas nitratireducens) possessed the cbbL gene encoding RuBisCO form I, while the cbbM gene encoding RuBisCO form II was detected only in some of the pure cultures. The general topologies of the CbbL/CbbM trees and the 16S rRNA gene tree were different, but both markers showed that the halophilic SOB genera formed independent lineages in the Gammaproteobacteria. In some cases, such as with several strains of the genus Thiohalospira and with Thioalkalibacter halophilus, the cbbL clustering was incongruent with the positions of these strains on the ribosomal tree. In the cbbM tree, the clustering of Thiohalospira and Thiohalorhabdus strains was incongruent with their branching in both cbbL and 16S rRNA gene trees. cbbL and cbbM genes related to those found in the analysed halophilic SOB were also detected in a sediment from a hypersaline lake in Kulunda Steppe (Russia). Most of the cbbL and cbbM genes belonged to members of the genus Thiohalorhabdus. In the cbbL clone library, sequences related to those of Halothiobacillus and Thiohalospira were detected as minor components. Some of the environmental cbbM sequences belonged to as yet unknown phylotypes, representing deep lineages of halophilic autotrophs. PMID:20299400

  13. 238U-230Th crystallization ages for the oldest domes of the Mono Craters, eastern California

    NASA Astrophysics Data System (ADS)

    Marcaida, M.; Vazquez, J. A.

    2014-12-01

    The Mono Craters volcanic chain is one of the youngest areas of rhyolitic volcanism in the Mono Lake-Long Valley region of eastern California. Located just south of Mono Lake, the Mono Craters comprise at least 28 individual domes and flows (numbered 3-30, north to south); however, the timing and frequency of eruptions remain poorly resolved. The earliest signs of volcanic activity are preserved as numerous tephra layers (Ashes 1-19, top to bottom) in the late Pleistocene Wilson Creek formation of ancestral Mono Lake, which indicate that rhyolitic volcanism from Mono Craters began by at least ca. 62 ka [1]. Although the current chronology indicates that most of the Mono Craters are younger than ca. 20 ka [2-4], similar compositions of titanomagnetite from both pumice and lava potentially correlate several Wilson Creek tephras to porphyritic biotite-bearing domes 11, 24, and 19 of the Mono Craters [5], suggesting that multiple domes in the Mono Craters chain reflect volcanism older than ca. 20 ka. Ash 3 is correlated to dome 11 based on similar ca. 20 ka ages and titanomagnetite compositions [6]. More recently, we performed ion microprobe 238U-230Th dating of unpolished rims of allanite and zircon from domes 24 and 19, yielding isochron ages of ca. 38 ka and ca. 42 ka, respectively. The age of dome 24 is consistent with the ca. 38 ka age of its potential correlative tephra layers [1, 5], indicating that dome 24 is likely the extrusive equivalent of Ashes 9-10. Dome 19 has titanomagnetite crystals with similar bimodal chemistry to titanomagnetites from Ash 15 [5]. The age of dome 19 is indistinguishable from the 238U-230Th age of Ash 15 [1], which erupted during a prominent geomagnetic excursion, originally designated as the "Mono Lake" excursion. Combining geochronological and titanomagnetite compositional data confirms that Ash 15 and its extrusive equivalent, dome 19, erupted during the Laschamp excursion. [1] Vazquez, J.A. and Lidzbarski, M.I. (2012) EPSL 357

  14. Alkaline chemistry of transuranium elements and technetium and the treatment of alkaline radioactive wastes

    SciTech Connect

    Delegard, C.H.; Peretrukhin, V.F.; Shilov, V.P.; Pikaev, A.K.

    1995-05-01

    Goal of this survey is to generalize the known data on fundamental physical-chemical properties of TRUs and Tc, methods for their isolation, and to provide recommendations that will be useful for partitioning them from alkaline high-level wastes.

  15. DNA DAMAGE QUANTITATION BY ALKALINE GEL ELECTROPHORESIS.

    SciTech Connect

    SUTHERLAND,B.M.; BENNETT,P.V.; SUTHERLAND, J.C.

    2004-03-24

    Physical and chemical agents in the environment, those used in clinical applications, or encountered during recreational exposures to sunlight, induce damages in DNA. Understanding the biological impact of these agents requires quantitation of the levels of such damages in laboratory test systems as well as in field or clinical samples. Alkaline gel electrophoresis provides a sensitive (down to {approx} a few lesions/5Mb), rapid method of direct quantitation of a wide variety of DNA damages in nanogram quantities of non-radioactive DNAs from laboratory, field, or clinical specimens, including higher plants and animals. This method stems from velocity sedimentation studies of DNA populations, and from the simple methods of agarose gel electrophoresis. Our laboratories have developed quantitative agarose gel methods, analytical descriptions of DNA migration during electrophoresis on agarose gels (1-6), and electronic imaging for accurate determinations of DNA mass (7-9). Although all these components improve sensitivity and throughput of large numbers of samples (7,8,10), a simple version using only standard molecular biology equipment allows routine analysis of DNA damages at moderate frequencies. We present here a description of the methods, as well as a brief description of the underlying principles, required for a simplified approach to quantitation of DNA damages by alkaline gel electrophoresis.

  16. Autonomous in situ measurements of seawater alkalinity.

    PubMed

    Spaulding, Reggie S; DeGrandpre, Michael D; Beck, James C; Hart, Robert D; Peterson, Brittany; De Carlo, Eric H; Drupp, Patrick S; Hammar, Terry R

    2014-08-19

    Total alkalinity (AT) is an important parameter for describing the marine inorganic carbon system and understanding the effects of atmospheric CO2 on the oceans. Measurements of AT are limited, however, because of the laborious process of collecting and analyzing samples. In this work we evaluate the performance of an autonomous instrument for high temporal resolution measurements of seawater AT. The Submersible Autonomous Moored Instrument for alkalinity (SAMI-alk) uses a novel tracer monitored titration method where a colorimetric pH indicator quantifies both pH and relative volumes of sample and titrant, circumventing the need for gravimetric or volumetric measurements. The SAMI-alk performance was validated in the laboratory and in situ during two field studies. Overall in situ accuracy was -2.2 ± 13.1 μmol kg(-1) (n = 86), on the basis of comparison to discrete samples. Precision on duplicate analyses of a carbonate standard was ±4.7 μmol kg(-1) (n = 22). This prototype instrument can measure in situ AT hourly for one month, limited by consumption of reagent and standard solutions. PMID:25051401

  17. Solubility of uranium in alkaline salt solutions

    SciTech Connect

    Hobbs, D.T.; Edwards, T.B.

    1994-03-29

    The solubility of uranium in alkaline salt solutions was investigated to screen for significant factors and interactions among the major salt components and temperature. The components included in the study were the sodium salts of hydroxide, nitrate, nitrite, aluminate, sulfate, and carbonate. General findings from the study included: (1) uranium solubilities are very low (1-20 mg/L) for all solution compositions at hydroxide concentrations from 0.1 to 17 molar (2) carbonate, sulfate, and aluminate are not effective complexants for uranium at high hydroxide concentration, (3) uranium solubility decreases with increasing temperature for most alkaline salt solutions, and (4) uranium solubility increases with changes in solution chemistry that reflect aging of high level waste (increase in nitrite and carbonate concentrations, decrease in nitrate and hydroxide concentrations). A predictive model for the concentration of uranium as a function of component concentrations and temperature was fitted to the data. All of the solution components and temperature were found to be significant. There is a significant lack of fit for the model, which suggests that the dependence on the uranium solubility over the wide range of solution compositions is non-linear and/or that there are other uncontrolled parameters which are important to the uranium solubility.

  18. Molecular modeling of human alkaline sphingomyelinase.

    PubMed

    Suresh, Panneer Selvam; Olubiyi, Olujide; Thirunavukkarasu, Chinnasamy; Strodel, Birgit; Kumar, Muthuvel Suresh

    2011-01-01

    Alkaline sphingomyelinase, which is expressed in the human intestine and hydrolyses sphingomyelin, is a component of the plasma and the lysosomal membranes. Hydrolase of sphingomyelin generates ceramide, sphingosine, and sphingosine 1-phosphate that have regulatory effects on vital cellular functions such as proliferation, differentiation, and apoptosis. The enzyme belongs to the Nucleotide Pyrophosphatase/Phosphodiesterase family and it differs in structural similarity with acidic and neutral sphingomyelinase. In the present study we modeled alkaline sphingomyelinase using homology modeling based on the structure of Nucleotide Pyrophosphatase/Phosphodiesterase from Xanthomonas axonopodis with which it shares 34% identity. Homology modeling was performed using Modeller9v7. We found that Cys78 and Cys394 form a disulphide bond. Further analysis shows that Ser76 may be important for the function of this enzyme, which is supported by the findings of Wu et al. (2005), that S76F abolishes the activity completely. We found that the residues bound to Zn(2+) are conserved and geometrically similar with the template. Molecular Dynamics simulations were carried out for the modeled protein to observe the effect of Zinc metal ions. It was observed that the metal ion has little effect with regard to the stability but induces increased fluctuations in the protein. These analyses showed that Zinc ions play an important role in stabilizing the secondary structure and in maintaining the compactness of the active site. PMID:21544170

  19. Bone alkaline phosphatase in rheumatic diseases.

    PubMed

    Beyeler, C; Banks, R E; Thompson, D; Forbes, M A; Cooper, E H; Bird, H

    1995-07-01

    A double monoclonal immunoradiometric assay specific for bone alkaline phosphatase (BAP) was used to determine whether the raised total alkaline phosphatase (TAP) often found in patients with active rheumatoid arthritis (RA) and ankylosing spondylitis (AS) is derived from bone or liver. Fifty-eight patients with RA were compared to 14 with AS and 14 with non-inflammatory rheumatic diseases (NI). None had clinical liver disease and only one had a slightly elevated aspartate transaminase activity. Elevated BAP concentrations were found in seven patients (5 RA, 1 AS, 1 NI), only two of whom also had abnormal TAP. Abnormal TAP activities were found in only three patients (all RA). BAP did not correlate with disease activity in RA or AS. In contrast, TAP correlated with disease activity (assessed by plasma viscosity) in RA (P < 0.002) and gamma-glutamyl transferase (GGT) also correlated with plasma viscosity in RA (P < 0.01). Both TAP and BAP were significantly correlated with GGT in RA (P < 0.001 and P < 0.02, respectively). These findings are discussed, together with possible reasons for the conflicting nature of some of the observations. PMID:7486797

  20. Advanced inorganic separators for alkaline batteries

    NASA Technical Reports Server (NTRS)

    Sheibley, D. W. (Inventor)

    1982-01-01

    A flexible, porous battery separator comprising a coating applied to a porous, flexible substrate is described. The coating comprises: (1) a thermoplastic rubber-based resin which is insoluble and unreactive in the alkaline electrolyte; (2) a polar organic plasticizer which is reactive with the alkaline electrolyte to produce a reaction product which contains a hydroxyl group and/or a carboxylic acid group; and (3) a mixture of polar particulate filler materials which are unreactive with the electrolyte, the mixture comprising at least one first filler material having a surface area of greater than 25 meters sq/gram, at least one second filler material having a surface area of 10 to 25 sq meters/gram, wherein the volume of the mixture of filler materials is less than 45% of the total volume of the fillers and the binder, the filler surface area per gram of binder is about 20 to 60 sq meters/gram, and the amount of plasticizer is sufficient to coat each filler particle. A method of forming the battery separator is also described.

  1. Kinetics of the phthalate metabolites mono-2-ethylhexyl phthalate (MEHP) and mono-n-butyl phthalate (MnBP) in male subjects after a single oral dose.

    PubMed

    Mittermeier, Astrid; Völkel, Wolfgang; Fromme, Hermann

    2016-06-11

    Humans have been exposed to dialkyl ortho-phthalates for decades. Due to degradation the phthalate monoesters, responsible for the toxic effects, are additionally found in environmental media as well as food samples. Nevertheless, the toxicokinetic properties of the monoesters are not known. Therefore, metabolism of the phthalate monoesters mono-2-ethylhexyl phthalate (MEHP) and mono-n-butyl phthalate (MnBP) was studied in four male volunteers (23-58 years of age) after ingestion of a single dose of 50μg/kg bw D4-MEHP or 10μg/kg bw D4-MnBP. The main metabolites in urine were determined up to 46h after administration. In the MEHP-study, more than 90% of each metabolite appeared in the urine within the first 22h, and the average excreted amount of D4-MEHP and its four secondary metabolites was 62% of the administered dose. The highest value of 15% was observed for mono-2-ethyl-5-carboxy-pentyl phthalate (D4-5cx-MEPP). The mean elimination half-life of D4-MEHP was estimated to be 3.5±1.4h. In the MnBP-study, the total recovered values of D4-MnBP and its secondary metabolites ranged from 52% to 130%. The monoester itself, with a half-life of 1.9±0.5h, accounted for the majority of the ingested dose (92%), while the secondary metabolites D4-mono-3-hydroxy-n-butyl phthalate (D4-3OH-MnBP) and D4-3-carboxy-mono-propyl phthalate (D4-3cx-MPP) represented only 7.1% and 1.0% of the ingested dose, respectively. Overall, this study determined that the kinetics of the phthalate monoesters MEHP and MnBP after oral dosage are comparable to the properties of their diesters. PMID:27091076

  2. Tindallia californiensis sp. nov., a new anaerobic, haloalkaliphilic, spore-forming acetogen isolated from Mono Lake in California

    NASA Technical Reports Server (NTRS)

    Pikuta, E. V.; Hoover, R. B.; Bej, A. K.; Marsic, D.; Detkova, E. N.; Whitman, W. B.; Krader, P.

    2003-01-01

    A novel extremely haloalkaliphilic, strictly anaerobic, acetogenic bacterium strain APO was isolated from sediments of the athalassic, meromictic, alkaline Mono Lake in California. The Gram-positive, spore-forming, slightly curved rods with sizes 0.55- 0.7x1.7-3.0 microns were motile by a single laterally attached flagellum. Strain APO was mesophilic (range 10-48 C, optimum of 37 C); halophilic (NaCl range 1-20% (w/v) with optimum of 3-5% (w/v), and alkaliphilic (pH range 8.0-10.5, optimum 9.5). The novel isolate required sodium ions in the medium. Strain APO was an organotroph with a fermentative type of metabolism and used the substrates peptone, bacto-tryptone, casamino acid, yeast extract, L-serine, L-lysine, L-histidine, L-arginine, and pyruvate. The new isolate performed the Stickland reaction with the following amino acid pairs: proline + alanine, glycine + alanine, and tryptophan + valine. The main end product of growth was acetate. High activity of CO dehydrogenase and hydrogenase indicated the presence of a homoacetogenic, non-cycling acetyl-coA pathway. Strain APO was resistant to kanamycin but sensitive to chloramphenicol, tetracycline, and gentamycin. The G+C content of the genomic DNA was 44.4 mol% (by HPLC method). The sequence of the 16s rRNA gene of strain APO possessed 98.2% similarity with the sequence from Tindullia magadiensis Z-7934, but the DNA-DNA hybridization value between these organisms was only 55%. On the basis of these physiological and molecular properties, strain APO is proposed to be a novel species of the genus Tindallia with the name Tindallia californiensis sp. nov., (type strain APO = ATCC BAA-393 - DSM 14871).

  3. The corrosion resistance of thermoset composites in alkaline environments

    SciTech Connect

    Kelley, D.H.; Thompson, M.J.

    1998-12-31

    Corrosion engineers need guidelines for selecting thermoset resins for aggressive applications such as hot alkali and alkaline peroxide. The suitability of fiberglass-reinforced plastic (FRP) for alkaline service depends on factors such as the ester content of the resin, the unsaturated monomer composition, and the cure system. The purpose of the present paper is to show the effect of these factors on the alkaline corrosion resistance of FRP and provide corrosion engineers with the guidance needed for selecting the best epoxy vinyl ester resins for alkaline environments.

  4. Rechargeable Zn-MnO sub 2 alkaline batteries

    SciTech Connect

    Wruck, W.J.; Reichman, B.; Bullock, K.R.; Kao, W.H. )

    1991-12-01

    In this paper progress in the development of rechargeable alkaline zinc-manganese dioxide cells is described. The advantages and limitations of the system are evaluated. Laboratory tests run on commercial primary alkaline cells as well as model simulations of a bipolar MnO{sub 2} electrode show that the rechargeable alkaline battery may be able to compete with lead-acid, nickel-cadmium, and secondary lithium cells for low- to moderate-rate applications. However, because of this poor performance at high rates and low temperatures, the alkaline MnO{sub 2} battery is not suitable for present automotive starting applications.

  5. Effect of alkaline addition on anaerobic sludge digestion with combined pretreatment of alkaline and high pressure homogenization.

    PubMed

    Fang, Wei; Zhang, Panyue; Zhang, Guangming; Jin, Shuguang; Li, Dongyi; Zhang, Meixia; Xu, Xiangzhe

    2014-09-01

    To improve anaerobic digestion efficiency, combination pretreatment of alkaline and high pressure homogenization was applied to pretreat sewage sludge. Effect of alkaline dosage on anaerobic sludge digestion was investigated in detail. SCOD of sludge supernatant significantly increased with the alkaline dosage increase after the combined pretreatment because of sludge disintegration. Organics were significantly degraded after the anaerobic digestion, and the maximal SCOD, TCOD and VS removal was 73.5%, 61.3% and 43.5%, respectively. Cumulative biogas production, methane content in biogas and biogas production rate obviously increased with the alkaline dosage increase. Considering both the biogas production and alkaline dosage, the optimal alkaline dosage was selected as 0.04 mol/L. Relationships between biogas production and sludge disintegration showed that the accumulative biogas was mainly enhanced by the sludge disintegration. The methane yield linearly increased with the DDCOD increase as Methane yield (ml/gVS)=4.66 DDCOD-9.69. PMID:24703958

  6. Substrate and Transition State Binding in Alkaline Phosphatase Analyzed by Computation of Oxygen Isotope Effects.

    PubMed

    Roston, Daniel; Cui, Qiang

    2016-09-14

    Enzymes are powerful catalysts, and a thorough understanding of the sources of their catalytic power will facilitate many medical and industrial applications. Here we have studied the catalytic mechanism of alkaline phosphatase (AP), which is one of the most catalytically proficient enzymes known. We have used quantum mechanics calculations and hybrid quantum mechanics/molecular mechanics (QM/MM) simulations to model a variety of isotope effects relevant to the reaction of AP. We have calculated equilibrium isotope effects (EIEs), binding isotope effects (BIEs), and kinetic isotope effects (KIEs) for a range of phosphate mono- and diester substrates. The results agree well with experimental values, but the model for the reaction's transition state (TS) differs from the original interpretation of those experiments. Our model indicates that isotope effects on binding make important contributions to measured KIEs on V/K, which complicated interpretation of the measured values. Our results provide a detailed interpretation of the measured isotope effects and make predictions that can test the proposed model. The model indicates that the substrate is deformed in the ground state (GS) of the reaction and partially resembles the TS. The highly preorganized active site preferentially binds conformations that resemble the TS and not the GS, which induces the substrate to adapt to the enzyme, rather than the other way around-as with classic "induced fit" models. The preferential stabilization of the TS over the GS is what lowers the barrier to the chemical step. PMID:27541005

  7. Microbial Diversity in a Permanently Cold and Alkaline Environment in Greenland

    PubMed Central

    Glaring, Mikkel A.; Vester, Jan K.; Lylloff, Jeanette E.; Abu Al-Soud, Waleed; Sørensen, Søren J.; Stougaard, Peter

    2015-01-01

    The submarine ikaite columns located in the Ikka Fjord in Southern Greenland represent a unique, permanently cold (less than 6°C) and alkaline (above pH 10) environment and are home to a microbial community adapted to these extreme conditions. The bacterial and archaeal community inhabiting the ikaite columns and surrounding fjord was characterised by high-throughput pyrosequencing of 16S rRNA genes. Analysis of the ikaite community structure revealed the presence of a diverse bacterial community, both in the column interior and at the surface, and very few archaea. A clear difference in overall taxonomic composition was observed between column interior and surface. Whereas the surface, and in particular newly formed ikaite material, was primarily dominated by Cyanobacteria and phototrophic Proteobacteria, the column interior was dominated by Proteobacteria and putative anaerobic representatives of the Firmicutes and Bacteroidetes. The results suggest a stratification of the ikaite columns similar to that of classical soda lakes, with a light-exposed surface inhabited by primary producers and an anoxic subsurface. This was further supported by identification of major taxonomic groups with close relatives in soda lake environments, including members of the genera Rhodobaca, Dethiobacter, Thioalkalivibrio and Tindallia, as well as very abundant groups related to uncharacterised environmental sequences originally isolated from Mono Lake in California. PMID:25915866

  8. Dolomite Dissolution in Alkaline Cementious Media

    NASA Astrophysics Data System (ADS)

    Mittermayr, Florian; Klammer, Dietmar; Köhler, Stephan; Dietzel, Martin

    2010-05-01

    Chemical alteration of concrete has gained much attention over the past years as many cases of deterioration due to sulphate attack, thaumasite formation (TSA) or alkali silica reactions (ASR) have been reported in various constructions (Schmidt et al, 2009). Much less is known about the so called alkali carbonate reaction (ACR). It is believed that dolomite aggregates can react with the alkalis from the cement, dissolve and form calcite and brucite (Katayama, 2004). Due to very low solubility of dolomite in alkaline solutions this reaction seems doubtful. In this study we are trying to gain new insides about the conditions that can lead to the dissolution of dolomite in concrete. Therefore we investigated concrete samples from Austrian tunnels that show partially dissolved dolomite aggregates. Petrological analysis such as microprobe, SEM and Raman spectroscopy as well as a hydrochemical analysis of interstitial solutions and ground water and modelling with PhreeqC (Parkhurst and Appelo, 1999) are carried out. In addition a series of batch experiments is set up. Modelling approaches by PhreeqC show a thermodynamically possibility in the alkaline range when additional Ca2+ in solution causes dolomite to become more and more undersaturated as calcite gets supersaturated. Interacting ground water is enriched in Ca2+and saturated with respect to gypsum as marine evaporites are found in situ rocks. Furthermore it is more likely that Portlandite (Ca(OH)2) plays a more important role than Na and K in the cement. Portlandite acts as an additional Ca2+ source and is much more abundant than the alkalies. Some interstitial solutions are dominated mainly by Na+ and SO42- and reach concentrations up to 30 g/l TDS. It is believed that solutions can even reach thenardite saturation as efflorescences are found on the tunnel walls. In consequence dolomite solubility increases with increasing ionic strength. pH > 11 further accelerate the process of dedolomitization by the removal

  9. High resolution seismic reflection profiles of Holocene volcanic and tectonic features, Mono Lake, California

    NASA Astrophysics Data System (ADS)

    Jayko, A. S.; Hart, P. E.; Bursik, M. I.; McClain, J. S.; Moore, J. C.; Boyle, M.; Childs, J. R.; Novick, M.; Hill, D. P.; Mangan, M.; Roeske, S.

    2009-12-01

    The Inyo-Mono Craters of Long Valley and Mono Basin, California are the youngest eruptive vents of the Great Basin, USA and the second youngest in California. They are one of two seismically active volcanic centers with geothermal power production in the Walker Lane, western Great Basin, the other being the Coso Volcanic Field to the south. High resolution seismic reflection data collected from the northern tip of the Mono Craters eruptive centers in Mono Lake delinates two structural zones proximal to the active volcanic centers in Mono Lake. A growth structure drapped by ~30 m or more of bedded sediment shows increasing deformation and offset of clastic deposits on the northwest margin of the basin. Coherent thin-bedded stratigraphic sections with strong reflectors to 30-100m depth are preserved on the western and northern margins of the basin. The southern and southeastern areas of the lake are generally seismically opaque, due to extensive ash and tephra deposits as well as widespread methane. Thin pockets of well-bedded, poorly consolidated sediment of probable Holocene and last glacial age are present within intrabasin depressions providing some local age constraints on surfaces adjacent to volcanic vents and volcanically modified features.

  10. Review of the recording and age of the Mono Lake Excursion

    NASA Astrophysics Data System (ADS)

    Coe, R.; Liddicoat, J.

    2009-04-01

    Among the brief departures from gradual, long-term behaviour of the palaeomagnetic field in the Brunhes Normal Chron that reached opposite polarity or have a Virtual Geomagnetic Pole deep in the southern hemisphere, the first to be reported is the Laschamp Excursion (LE) in volcanic rocks in the Massif Central in France (Bonhommet and Zahringer, 1969). They originally believed it occurred between about 9,000 to 20,000 years before present, but it is now assigned an age of about 40,000 years B.P. (Guillou et al., 2004). Denham and Cox (1971) unsuccessfully sought the LE in exposed lake sediments that seemed to span that interval in the Mono Basin in the western Great Basin of the U.S., but instead encountered anomalous field behaviour that is called the Mono Lake Excursion (MLE)(Liddicoat and Coe, 1979). As a tribute to Norbert Bonhommet, who assisted us in our initial field work in the Mono Basin and shared a long-standing interest in the LE and MLE, we will review the palaeomagnetic behaviour and age of the MLE in the Mono Basin and elsewhere, for which there are nearly 20 reports of its occurrence globally, and evaluate the recent suggestion that the excursion at Mono Lake and the LE are the same.

  11. Alkaline pulping of some eucalypts from Sudan.

    PubMed

    Khristova, P; Kordsachia, O; Patt, R; Dafaalla, S

    2006-03-01

    Four eucalypts (Eucalyptus camaldulensis, Eucalyptus microtheca, Eucalyptus tereticornis and Eucalyptus citriodora) grown in Sudan were examined for their suitability for pulping and papermaking with different alkaline methods. Their physical, morphological and chemical characteristics are reported. The pulping trials with E. citriodora and E. tereticornis were carried out using the kraft-AQ, soda-AQ, modified AS/AQ (ASA), ASAM and kraft methods. For the other two species, only the ASAM and the kraft process were applied. ASAM pulping gave the best results in terms of yield, degree of delignification, mechanical and optical pulp properties. The best pulps, obtained in kraft and ASAM cooking of E. citriodora, were bleached to 88% ISO brightness in a totally chlorine free bleaching sequence (OQ1O/PQ2P). The bleached pulps, especially the ASAM pulp, showed good papermaking properties and would be suitable for manufacture of writing and printing grades of paper. PMID:15935655

  12. Alkaline oxide conversion coatings for aluminum alloys

    SciTech Connect

    Buchheit, R.G.

    1996-02-01

    Three related conversion coating methods are described that are based on film formation which occurs when aluminum alloys are exposed to alkaline Li salt solutions. Representative examples of the processing methods, resulting coating structure, composition and morphology are presented. The corrosion resistance of these coatings to aerated 0.5 M NaCl solution has been evaluated as a function of total processing time using electrochemical impedance spectroscopy (EIS). This evaluation shows that excellent corrosion resistance can be uniformly achieved using no more than 20 minutes of process time for 6061-T6. Using current methods a minimum of 80 minutes of process time is required to get marginally acceptable corrosion resistance for 2024-T3. Longer processing times are required to achieve uniformly good corrosion resistance.

  13. Alkaline dechlorination of chlorinated volatile organic compounds

    SciTech Connect

    Gu, B.; Siegrist, R.L.

    1996-06-01

    The vast majority of contaminated sites in the United States and abroad are contaminated with chlorinated volatile organic compounds (VOCs) such as trichloroethylene (TCE), trichloroethane (TCA), and chloroform. These VOCs are mobile and persistent in the subsurface and present serious health risks at trace concentrations. The goal of this project was to develop a new chemical treatment system that can rapidly and effectively degrade chlorinated VOCs. The system is based on our preliminary findings that strong alkalis such as sodium hydroxide (NaOH) can absorb and degrade TCE. The main objectives of this study were to determine the reaction rates between chlorinated VOCs, particularly TCE, and strong alkalis, to elucidate the reaction mechanisms and by-products, to optimize the chemical reactions under various experimental conditions, and to develop a laboratory bench- scale alkaline destruction column that can be used to destroy vapor- phase TCE.

  14. The Alkaline Dissolution Rate of Calcite.

    PubMed

    Colombani, Jean

    2016-07-01

    Due to the widespread presence of calcium carbonate on Earth, several geochemical systems, among which is the global CO2 cycle, are controlled to a large extent by the dissolution and precipitation of this mineral. For this reason, the dissolution of calcite has been thoroughly investigated for decades. Despite this intense activity, a consensual value of the dissolution rate of calcite has not been found yet. We show here that the inconsistency between the reported values stems mainly from the variability of the chemical and hydrodynamic conditions of measurement. The spreading of the values, when compared in identical conditions, is much less than expected and is interpreted in terms of sample surface topography. This analysis leads us to propose benchmark values of the alkaline dissolution rate of calcite compatible with all the published values, and a method to use them in various chemical and hydrodynamic contexts. PMID:27282839

  15. Properties of cathode materials in alkaline cells

    NASA Astrophysics Data System (ADS)

    Salkind, A. J.; McBreen, J.; Freeman, R.; Parkhurst, W. A.

    1984-04-01

    Conventional and new cathode materials in primary and secondary alkaline cells were investigated for stability, structure, electrochemical reversibility and efficiency. Included were various forms of AgO for reserve type silver zinc batteries, a new material - AgNiO2 and several nickel electrodes for nickel cadmium and nickel hydrogen cells for aerospace applications. A comparative study was made of the stability of electroformed and chemically prepared AgO. Stability was correlated with impurities. After the first discharge AgNiO2 can be recharged to the monovalent level. The discharge product is predominantly silver. Plastic bonded nickel electrodes display a second plateau on discharge. Additions of Co(OH)2 largely eliminate this.

  16. Polyvinyl alcohol membranes as alkaline battery separators

    NASA Technical Reports Server (NTRS)

    Sheibley, D. W.; Gonzalez-Sanabria, O.; Manzo, M. A.

    1982-01-01

    Polyvinly alcohol (PVA) cross-linked with aldehyde reagents yields membranes that demonstrate properties that make them suitable for use as alkaline battery separators. Film properties can be controlled by the choice of cross-linker, cross-link density and the method of cross-linking. Three methods of cross-linking and their effects on film properties are discussed. Film properties can also be modified by using a copolymer of vinyl alcohol and acrylic acid as the base for the separator and cross-linking it similarly to the PVA. Fillers can be incorporated into the films to further modify film properties. Results of separator screening tests and cell tests for several variations of PBA films are discussed.

  17. Oxygen electrodes for rechargeable alkaline fuel cells

    NASA Technical Reports Server (NTRS)

    Swette, Larry; Giner, Jose

    1987-01-01

    Electrocatalysts and supports for the positive electrode of moderate temperature single unit rechargeable alkaline fuel cells were investigated and developed. The electrocatalysts are defined as the material with a higher activity for the oxygen electrode reaction than the support. Advanced development will require that the materials be prepared in high surface area forms, and may also entail integration of various candidate materials. Eight candidate support materials and seven electrocatalysts were investigated. Of the 8 support, 3 materials meet the preliminary requirements in terms of electrical conductivity and stability. Emphasis is now on preparing in high surface area form and testing under more severe corrosion stress conditions. Of the 7 electrocatalysts prepared and evaluated, at least 5 materials remain as potential candidates. The major emphasis remains on preparation, physical characterization and electrochemical performance testing.

  18. Development of an alkaline fuel cell subsystem

    NASA Technical Reports Server (NTRS)

    1987-01-01

    A two task program was initiated to develop advanced fuel cell components which could be assembled into an alkaline power section for the Space Station Prototype (SSP) fuel cell subsystem. The first task was to establish a preliminary SSP power section design to be representative of the 200 cell Space Station power section. The second task was to conduct tooling and fabrication trials and fabrication of selected cell stack components. A lightweight, reliable cell stack design suitable for the SSP regenerative fuel cell power plant was completed. The design meets NASA's preliminary requirements for future multikilowatt Space Station missions. Cell stack component fabrication and tooling trials demonstrated cell components of the SSP stack design of the 1.0 sq ft area can be manufactured using techniques and methods previously evaluated and developed.

  19. The Nickel(111)/Alkaline Electrolyte Interface

    NASA Technical Reports Server (NTRS)

    Wang, Kuilong; Chottiner, G. S.; Scherson, D. A.; Reid, Margaret A.

    1991-01-01

    The electrochemical properties of Ni (111) prepared and characterized in ultra high vacuum, UHV, by surface analytical techniques have been examined in alkaline media by cyclic voltammetry using an UHV-electrochemical cell transfer system designed and built in this laboratory. Prior to the transfer, the Ni(111) surfaces were exposed to saturation coverages of CO in UHV in an attempt to protect the surface from possible contamination with other gases during the transfer. Temperature Programmed Desorption, TPD, of CO-dosed Ni (111) surfaces displaying sharp c(4x2), LEED patterns, subsequently exposed to water-saturated Ar at atmospheric pressure in an auxiliary UHV compatible chamber and finally transferred back to the main UHV chamber, yielded CO2 and water as the only detectable products. This indicates that the CO-dosed surfaces react with water and/or bicarbonate and hydroxide as the most likely products. Based on the integration of the TPD peaks, the combined amounts of H2O and CO2 were found to be on the order of a single monolayer. The reacted c(4x2)CO/Ni(111) layer seems to protect the surface from undergoing spontaneous oxidation in strongly alkaline solutions. This was evidenced by the fact that the open circuit potential observed immediately after contact with deaerated 0.1 M KOH was about 0.38 V vs. DHE, drifting slightly towards more negative values prior to initiating the voltametric scans. The average ratio of the integrated charge obtained in the first positive linear scan in the range of 0.35 to 1.5 V vs. DHE (initiated at the open circuit potential) and the first (and subsequent) linear negative scans in the same solution yielded for various independent runs a value of 3.5 +/- 0.3. Coulometric analysis of the cyclic voltammetry curves indicate that the electrochemically formed oxyhydroxide layer involves a charge equivalent to 3.2 +/- 0.4 layers of Ni metal.

  20. Alkaline cleaner replacement for printed wiring board fabrication

    SciTech Connect

    Goldammer, S.E.; Pemberton, S.E.; Tucker, D.R.

    1997-04-01

    A replacement alkaline cleaning chemistry was qualified for the copper cleaning process used to support printed wiring board fabrication. The copper cleaning process was used to prepare copper surfaces for enhancing the adhesion of dry film photopolymers (photoresists and solder masks) and acrylic adhesives. The alkaline chemistry was used to remove organic contaminates such as fingerprints.

  1. TOTAL ALKALINITY OF SURFACE WATERS OF THE US

    EPA Science Inventory

    This map provides a synoptic illustration of the national patterns of surface water alkalinity in the conterminous United States. Alkalinity is the most readily available measure of the acid-neutralizing capacity of surface waters and provides a reasonable estimate o...

  2. Removal of plutonium and americium from alkaline waste solutions

    DOEpatents

    Schulz, Wallace W.

    1979-01-01

    High salt content, alkaline waste solutions containing plutonium and americium are contacted with a sodium titanate compound to effect removal of the plutonium and americium from the alkaline waste solution onto the sodium titanate and provide an effluent having a radiation level of less than 10 nCi per gram alpha emitters.

  3. The Chemistry of Paper Preservation Part 4. Alkaline Paper.

    ERIC Educational Resources Information Center

    Carter, Henry A.

    1997-01-01

    Discusses the problem of the inherent instability of paper due to the presence of acids that catalyze the hydrolytic degradation of cellulose. Focuses on the chemistry involved in the sizing of both acid and alkaline papers and the types of fillers used. Discusses advantages and problems of alkaline papermaking. Contains 48 references. (JRH)

  4. ANNUAL REPORT. ACTINIDE-ALUMINATE SPECIATION IN ALKALINE RADIOACTIVE WASTE

    EPA Science Inventory

    Highly alkaline radioactive waste tanks contain a number of transuranic species, in particular U, Np, Pu, and Am-the exact forms of which are currently unknown. Knowledge of actinide speciation under highly alkaline conditions is essential towards understanding and predicting the...

  5. DABCO mono-betaine hydrate studied by X-ray diffraction, DFT calculations and spectroscopic methods

    NASA Astrophysics Data System (ADS)

    Barczyński, P.; Dega-Szafran, Z.; Katrusiak, A.; Perdoch, W.; Szafran, M.

    2009-09-01

    A new DABCO mono-betaine (1-carboxymethyl-1,4-diazabicyclo[2.2.2]octane inner salt) has been synthesized. It crystallizes as monohydrate in orthorhombic space group Pmn2 1. The DABCO mono-betaine and water molecules are located on a mirror plane. The water molecules link DABCO mono-betaine into linear chains through the H-O-H⋯OOC and H-O-H⋯N hydrogen bonds of 2.709(2) and 2.875(2) Å. The structure of the title compound optimized at B3LYP/6-31G(d,p) level of theory is consistent with X-ray diffraction. The absorption bands in the FTIR spectrum have been assigned. The calculated magnetic isotropic shielding tensors confirm the assignments of the 13C NMR resonance signals.

  6. Second- and third-order nonlinear optical properties of unsubstituted and mono-substituted chalcones

    NASA Astrophysics Data System (ADS)

    Abegão, Luis M. G.; Fonseca, Ruben D.; Santos, Francisco A.; Souza, Gabriela B.; Barreiros, André Luis B. S.; Barreiros, Marizeth L.; Alencar, M. A. R. C.; Mendonça, Cleber R.; Silva, Daniel L.; De Boni, Leonardo; Rodrigues, J. J.

    2016-03-01

    This work describes the second and third orders of nonlinear optics properties of unsubstituted chalcone (C15H12O) and mono-substituted chalcone (C16H14O2) in solution, using hyper-Rayleigh scattering and Z-Scan techniques to determine the first molecular hyperpolarizability (β) and the two-photon absorption (2PA) cross section respectively. β Values of 25.4 × 10-30 esu and 31.6 × 10-30 esu, for unsubstituted and mono-substituted chalcone, respectively, dissolved in methanol have been obtained. The highest values of 2PA cross-sections obtained were 9 GM and 14 GM for unsubstituted and mono-substituted chalcone, respectively. The experimental 2PA cross sections obtained for each chalcone are in good agreement with theoretical results.

  7. A Coupled Meshless Technique/Molecular Dynamics Approach for Deformation Characterization of Mono-crystalline Metal

    SciTech Connect

    Gu, Y. T.; Yarlagadda, Prasad K. D. V.

    2010-05-21

    This paper presents a multiscale study using the coupled Meshless technique/Molecular Dynamics (M{sup 2}) for exploring the deformation mechanism of mono-crystalline metal (focus on copper) under uniaxial tension. In M{sup 2}, an advanced transition algorithm using transition particles is employed to ensure the compatibility of both displacements and their gradients, and an effective local quasi-continuum approach is also applied to obtain the equivalent continuum strain energy density based on the atomistic potentials and Cauchy-Born rule. The key parameters used in M{sup 2} are firstly investigated using a benchmark problem. Then, M{sup 2} is applied to the multiscale simulation for a mono-crystalline copper bar. It has found that the mono-crystalline copper has very good elongation property, and the ultimate strength and Young's modulus are much higher than those obtained in macro-scale.

  8. Salt- and alkaline-tolerance are linked in Acacia.

    PubMed

    Bui, Elisabeth N; Thornhill, Andrew; Miller, Joseph T

    2014-07-01

    Saline or alkaline soils present a strong stress on plants that together may be even more deleterious than alone. Australia's soils are old and contain large, sometimes overlapping, areas of high salt and alkalinity. Acacia and other Australian plant lineages have evolved in this stressful soil environment and present an opportunity to understand the evolution of salt and alkalinity tolerance. We investigate this evolution by predicting the average soil salinity and pH for 503 Acacia species and mapping the response onto a maximum-likelihood phylogeny. We find that salinity and alkalinity tolerance have evolved repeatedly and often together over 25 Ma of the Acacia radiation in Australia. Geographically restricted species are often tolerant of extreme conditions. Distantly related species are sympatric in the most extreme soil environments, suggesting lack of niche saturation. There is strong evidence that many Acacia have distributions affected by salinity and alkalinity and that preference is lineage specific. PMID:25079493

  9. Phosphatidylinositol anchor of HeLa cell alkaline phosphatase

    SciTech Connect

    Jemmerson, R.; Low, M.G.

    1987-09-08

    Alkaline phosphatase from cancer cells, HeLa TCRC-1, was biosynthetically labeled with either /sup 3/H-fatty acids or (/sup 3/H)ethanolamine as analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography of immunoprecipitated material. Phosphatidylinositol-specific phospholipase C (PI-PLC) released a substantial proportion of the /sup 3/H-fatty acid label from immunoaffinity-purified alkaline phosphatase but had no effect on the radioactivity of (/sup 3/H)ethanolamine-labeled material. PI-PLC also liberated catalytically active alkaline phosphatase from viable cells, and this could be selectively blocked by monoclonal antibodies to alkaline phosphatase. However, the alkaline phosphatase released from /sup 3/H-fatty acid labeled cells by PI-PLC was not radioactive. By contrast, treatment with bromelain removed both the /sup 3/H-fatty acid and the (/sup 3/H)ethanolamine label from purified alkaline phosphatase. Subtilisin was also able to remove the (/sup 3/H)ethanolamine label from the purified alkaline phosphatase. The /sup 3/H radioactivity in alkaline phosphatase purified from (/sup 3/H)ethanolamine-labeled cells comigrated with authentic (/sup 3/H)ethanolamine by anion-exchange chromatography after acid hydrolysis. The data suggest that the /sup 3/H-fatty acid and (/sup 3/H)ethanolamine are covalently attached to the carboxyl-terminal segment since bromelain and subtilisin both release alkaline phosphatase from the membrane by cleavage at that end of the polypeptide chain. The data are consistent with findings for other proteins recently shown to be anchored in the membrane through a glycosylphosphatidylinositol structure and indicate that a similar structure contributes to the membrane anchoring of alkaline phosphatase.

  10. Communication: Linking the dielectric Debye process in mono-alcohols to density fluctuations.

    PubMed

    Hecksher, Tina

    2016-04-28

    This work provides the first direct evidence that the puzzling dielectric Debye process observed in mono-alcohols is coupled to density fluctuations. The results open up for an explanation of the Debye process within the framework of conventional liquid-state theory. The spectral shape of the dynamical bulk modulus of the two studied mono-alcohols, 2-ethyl-1-hexanol and 4-methyl-3-heptanol, is nearly identical to that of their corresponding shear modulus, and thus the supramolecular structures believed to be responsible for the slow dielectric Debye process are manifested in the bulk modulus in the same way as in the shear modulus. PMID:27131521

  11. Comparative structure analysis of non-polar organic ferrofluids stabilized by saturated mono-carboxylic acids.

    PubMed

    Avdeev, M V; Bica, D; Vékás, L; Aksenov, V L; Feoktystov, A V; Marinica, O; Rosta, L; Garamus, V M; Willumeit, R

    2009-06-01

    The structure of ferrofluids (magnetite in decahydronaphtalene) stabilized with saturated mono-carboxylic acids of different chain lengths (lauric, myristic, palmitic and stearic acids) is studied by means of magnetization analysis and small-angle neutron scattering. It is shown that in case of saturated acid surfactants, magnetite nanoparticles are dispersed in the carrier approximately with the same size distribution whose mean value and width are significantly less as compared to the classical stabilization with non-saturated oleic acid. The found thickness of the surfactant shell around magnetite is analyzed with respect to stabilizing properties of mono-carboxylic acids. PMID:19376524

  12. Pro-apoptotic activity and mono-/diubiquitylation of Xenopus Bid in egg extracts

    SciTech Connect

    Saitoh, Tomohiro; Tsuchiya, Yuichi; Kinoshita, Toshihiko; Itoh, Motohiro; Yamashita, Shigeru

    2009-07-10

    Apoptosis in Xenopus egg extracts is carried out by maternally stockpiled materials, but the contributions of endogenous apoptosis regulators are still poorly characterized. Here we examined the physiological role of Xenopus Bid (xBid), a pro-apoptotic BH3-only member of Bcl-2 family proteins. We found that endogenous xBid was a physiological accelerator of apoptosis in egg extracts. Interestingly, xBid was mono-/diubiquitylated but not degraded by proteasome in egg extracts, and we identified three ubiquitylated Lys residues in the N-terminal propeptide region. Comparison with human Bid suggested that mono-/diubiquitylation is a specific feature of xBid.

  13. Aza-Michael Mono-addition Using Acidic Alumina under Solventless Conditions.

    PubMed

    Bosica, Giovanna; Abdilla, Roderick

    2016-01-01

    Aza-Michael reactions between primary aliphatic and aromatic amines and various Michael acceptors have been performed under environmentally-friendly solventless conditions using acidic alumina as a heterogeneous catalyst to selectively obtain the corresponding mono-adducts in high yields. Ethyl acrylate was the main acceptor used, although others such as acrylonitrile, methyl acrylate and acrylamide were also utilized successfully. Bi-functional amines also gave the mono-adducts in good to excellent yields. Such compounds can serve as intermediates for the synthesis of anti-cancer and antibiotic drugs. PMID:27338336

  14. Method for separating mono- and di-octylphenyl phosphoric acid esters

    DOEpatents

    Arnold, Jr., Wesley D.

    1977-01-01

    A method for separating mono-octylphenyl phosphoric acid ester and di-octylphenyl phosphoric acid ester from a mixture thereof comprises reacting the ester mixture with a source of lithium or sodium ions to form a mixture of the phosphate salts; contacting the salt mixture with an organic solvent which causes the dioctylphenyl phosphate salt to be dissolved in the organic solvent phase and the mono-octylphenyl phosphate salt to exist in a solid phase; separating the phases; recovering the phosphate salts from their respective phases; and acidifying the recovered salts to form the original phosphoric acid esters.

  15. Communication: Linking the dielectric Debye process in mono-alcohols to density fluctuations

    NASA Astrophysics Data System (ADS)

    Hecksher, Tina

    2016-04-01

    This work provides the first direct evidence that the puzzling dielectric Debye process observed in mono-alcohols is coupled to density fluctuations. The results open up for an explanation of the Debye process within the framework of conventional liquid-state theory. The spectral shape of the dynamical bulk modulus of the two studied mono-alcohols, 2-ethyl-1-hexanol and 4-methyl-3-heptanol, is nearly identical to that of their corresponding shear modulus, and thus the supramolecular structures believed to be responsible for the slow dielectric Debye process are manifested in the bulk modulus in the same way as in the shear modulus.

  16. Batteries: from alkaline to zinc-air.

    PubMed

    Dondelinger, Robert M

    2004-01-01

    There is no perfect disposable battery--one that will sit on the shelf for 20 years, then continually provide unlimited current, at a completely constant voltage until exhausted, without producing heat. There is no perfect rechargeable battery--one with all of the above characteristics and will also withstand an infinite overcharge while providing an equally infinite cycle life. There are only compromises. Every battery selection is a compromise between the ideally required characteristics, the advantages, and the limitations of each battery type. General selection of a battery type to power a medical device is largely outside the purview of the biomed. Initially, these are engineering decisions made at the time of medical equipment design and are intended to be followed in perpetuity. However, since newer cell types evolve and the manufacturer's literature is fixed at the time of printing, some intelligent substitutions may be made as long as the biomed understands the characteristics of both the recommended cell and the replacement cell. For example, when the manufacturer recommends alkaline, it is usually because of the almost constant voltage it produces under the devices' design load. Over time, other battery types may be developed that will meet the intent of the manufacturer, at a lower cost, providing longer operational life, at a lower environmental cost, or with a combination of these advantages. In the Obstetrical Doppler cited at the beginning of this article, the user had put in carbon-zinc cells, and the biomed had unknowingly replaced them with carbonzinc cells. If the alkaline cells recommended by the manufacturer had been used, there would have been the proper output voltage at the battery terminals when the [table: see text] cells were at their half-life. Instead, the device refused to operate since the battery voltage was below presumed design voltage. While battery-type substitutions may be easily and relatively successfully made in disposable

  17. Microbial thiocyanate utilization under highly alkaline conditions.

    PubMed

    Sorokin, D Y; Tourova, T P; Lysenko, A M; Kuenen, J G

    2001-02-01

    Three kinds of alkaliphilic bacteria able to utilize thiocyanate (CNS-) at pH 10 were found in highly alkaline soda lake sediments and soda soils. The first group included obligate heterotrophs that utilized thiocyanate as a nitrogen source while growing at pH 10 with acetate as carbon and energy sources. Most of the heterotrophic strains were able to oxidize sulfide and thiosulfate to tetrathionate. The second group included obligately autotrophic sulfur-oxidizing alkaliphiles which utilized thiocyanate nitrogen during growth with thiosulfate as the energy source. Genetic analysis demonstrated that both the heterotrophic and autotrophic alkaliphiles that utilized thiocyanate as a nitrogen source were related to the previously described sulfur-oxidizing alkaliphiles belonging to the gamma subdivision of the division Proteobacteria (the Halomonas group for the heterotrophs and the genus Thioalkalivibrio for autotrophs). The third group included obligately autotrophic sulfur-oxidizing alkaliphilic bacteria able to utilize thiocyanate as a sole source of energy. These bacteria could be enriched on mineral medium with thiocyanate at pH 10. Growth with thiocyanate was usually much slower than growth with thiosulfate, although the biomass yield on thiocyanate was higher. Of the four strains isolated, the three vibrio-shaped strains were genetically closely related to the previously described sulfur-oxidizing alkaliphiles belonging to the genus Thioalkalivibrio. The rod-shaped isolate differed from the other isolates by its ability to accumulate large amounts of elemental sulfur inside its cells and by its ability to oxidize carbon disulfide. Despite its low DNA homology with and substantial phenotypic differences from the vibrio-shaped strains, this isolate also belonged to the genus Thioalkalivibrio according to a phylogenetic analysis. The heterotrophic and autotrophic alkaliphiles that grew with thiocyanate as an N source possessed a relatively high level of cyanase

  18. Microbial Thiocyanate Utilization under Highly Alkaline Conditions

    PubMed Central

    Sorokin, Dimitry Y.; Tourova, Tatyana P.; Lysenko, Anatoly M.; Kuenen, J. Gijs

    2001-01-01

    Three kinds of alkaliphilic bacteria able to utilize thiocyanate (CNS−) at pH 10 were found in highly alkaline soda lake sediments and soda soils. The first group included obligate heterotrophs that utilized thiocyanate as a nitrogen source while growing at pH 10 with acetate as carbon and energy sources. Most of the heterotrophic strains were able to oxidize sulfide and thiosulfate to tetrathionate. The second group included obligately autotrophic sulfur-oxidizing alkaliphiles which utilized thiocyanate nitrogen during growth with thiosulfate as the energy source. Genetic analysis demonstrated that both the heterotrophic and autotrophic alkaliphiles that utilized thiocyanate as a nitrogen source were related to the previously described sulfur-oxidizing alkaliphiles belonging to the gamma subdivision of the division Proteobacteria (the Halomonas group for the heterotrophs and the genus Thioalkalivibrio for autotrophs). The third group included obligately autotrophic sulfur-oxidizing alkaliphilic bacteria able to utilize thiocyanate as a sole source of energy. These bacteria could be enriched on mineral medium with thiocyanate at pH 10. Growth with thiocyanate was usually much slower than growth with thiosulfate, although the biomass yield on thiocyanate was higher. Of the four strains isolated, the three vibrio-shaped strains were genetically closely related to the previously described sulfur-oxidizing alkaliphiles belonging to the genus Thioalkalivibrio. The rod-shaped isolate differed from the other isolates by its ability to accumulate large amounts of elemental sulfur inside its cells and by its ability to oxidize carbon disulfide. Despite its low DNA homology with and substantial phenotypic differences from the vibrio-shaped strains, this isolate also belonged to the genus Thioalkalivibrio according to a phylogenetic analysis. The heterotrophic and autotrophic alkaliphiles that grew with thiocyanate as an N source possessed a relatively high level of cyanase

  19. Net alkalinity and net acidity 2: Practical considerations

    USGS Publications Warehouse

    Kirby, C.S.; Cravotta, C.A., III

    2005-01-01

    The pH, alkalinity, and acidity of mine drainage and associated waters can be misinterpreted because of the chemical instability of samples and possible misunderstandings of standard analytical method results. Synthetic and field samples of mine drainage having various initial pH values and concentrations of dissolved metals and alkalinity were titrated by several methods, and the results were compared to alkalinity and acidity calculated based on dissolved solutes. The pH, alkalinity, and acidity were compared between fresh, unoxidized and aged, oxidized samples. Data for Pennsylvania coal mine drainage indicates that the pH of fresh samples was predominantly acidic (pH 2.5-4) or near neutral (pH 6-7); ??? 25% of the samples had pH values between 5 and 6. Following oxidation, no samples had pH values between 5 and 6. The Standard Method Alkalinity titration is constrained to yield values >0. Most calculated and measured alkalinities for samples with positive alkalinities were in close agreement. However, for low-pH samples, the calculated alkalinity can be negative due to negative contributions by dissolved metals that may oxidize and hydrolyze. The Standard Method hot peroxide treatment titration for acidity determination (Hot Acidity) accurately indicates the potential for pH to decrease to acidic values after complete degassing of CO2 and oxidation of Fe and Mn, and it indicates either the excess alkalinity or that required for neutralization of the sample. The Hot Acidity directly measures net acidity (= -net alkalinity). Samples that had near-neutral pH after oxidation had negative Hot Acidity; samples that had pH < 6.3 after oxidation had positive Hot Acidity. Samples with similar pH values before oxidation had dissimilar Hot Acidities due to variations in their alkalinities and dissolved Fe, Mn, and Al concentrations. Hot Acidity was approximately equal to net acidity calculated based on initial pH and dissolved concentrations of Fe, Mn, and Al minus the

  20. 21 CFR 582.4521 - Monosodium phosphate derivatives of mono- and diglycerides of edible fats or oils, or edible fat...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... diglycerides of edible fats or oils, or edible fat-forming fatty acids. 582.4521 Section 582.4521 Food and... Monosodium phosphate derivatives of mono- and diglycerides of edible fats or oils, or edible fat-forming fatty acids. (a) Product. Monosodium phosphate derivatives of mono- and diglycerides of edible fats...