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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. 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.

  8. 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

  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. 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

  3. 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

  4. 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

  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. 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

  18. 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

  19. 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.

  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. 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

  4. 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

  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. 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

  12. 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

  13. 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

  14. 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.

  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. 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

  4. 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

  5. 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

  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 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

  11. 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

  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. 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.

  14. 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…

  15. 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

  16. 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

  17. 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

  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. 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.

  20. 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

  1. 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...

  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. 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

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  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. 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…

  20. 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…

  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. 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

  3. 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

  4. 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

  5. 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.

  6. 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

  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. 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

  9. 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

  10. 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.

  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. 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

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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.

  5. 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

  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. 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

  9. 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

  10. 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

  11. 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

  12. 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

  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. 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.

  1. 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

  2. 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.

  3. 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.

  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. 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.

  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. 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

  9. 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

  10. 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

  11. 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

  12. 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

  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. 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.

  3. 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

  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. 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

  6. 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

  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. 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

  13. 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

  14. 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

  15. 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

  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. 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.

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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.

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  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. 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.

  14. 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

  15. 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

  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. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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

  3. 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.

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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