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- Peer-Reviewed Journal Publications (6)
- Sinorhizobium meliloti (4)
- Temperature (3)
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- Carbon dioxide (2)
- Colicin (2)
- Desiccation (2)
- 18S (1)
- A Reliable and High Yielding Method for Isolation of Genomic DNA from Ammi majus. (1)
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- Actinobacteria (1)
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- An efficient biotreatment process for polyvinyl alcohol containing textile wastewater (1)
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- Arctic (1)
- Bacteriocin (1)
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- Chloride (1)
- Climate change (1)
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Articles 1 - 30 of 39
Full-Text Articles in Life Sciences
Changes In Microbial Communities Along Redox Gradients In Polygonized Arctic Wet Tundra Soils, David A. Lipson, Ted K. Raab, Melanie Parker, Scott T. Kelley, Colin J. Brislawn, Janet Jansson
Changes In Microbial Communities Along Redox Gradients In Polygonized Arctic Wet Tundra Soils, David A. Lipson, Ted K. Raab, Melanie Parker, Scott T. Kelley, Colin J. Brislawn, Janet Jansson
Ted K. Raab
This study investigated how microbial community structure and diversity varied with depth and topography in ice wedge polygons of wet tundra of the Arctic Coastal Plain in northern Alaska, and what soil variables explain these patterns. We observed strong changes in community structure and diversity with depth, and more subtle changes between areas of high and low topography, with the largest differences apparent near the soil surface. These patterns are most strongly correlated with redox gradients (measured using the ratio of reduced Fe to total Fe in acid extracts as a proxy): conditions grew more reducing with depth and were …
Influence Of Current Land Use And Edaphic Factors On Arbuscular Mycorrhizal (Am) Hyphal Abundance And Soil Organic Matter In And Near Serengeti National Park, Geofrey Soka, Mark Ritchie, Emilian Mayemba
Influence Of Current Land Use And Edaphic Factors On Arbuscular Mycorrhizal (Am) Hyphal Abundance And Soil Organic Matter In And Near Serengeti National Park, Geofrey Soka, Mark Ritchie, Emilian Mayemba
Geofrey Soka
Arbuscular mycorrhizal fungi (AMF) are important microbial symbionts for plants especially when soil phosphorus (P) and nitrogen (N) are limited. Little is known about the distribution of AM hyphae in natural systems of tropical soils across landscapes and their association with different land uses. We studied mycorrhizal hyphal abundance in a wildlife grazed system, a livestock grazed system and under cultivated soils in and near Serengeti National Park, Tanzania. Samples of the upper 15 cm of soil beneath locally dominant plant species were collected. Hyphae were preserved on permanent slides and the length of hyphae per cubic centimeter of soil …
Comparative Studies Of Oleaginous Fungal Strains (Mucor Circinelloides And Trichoderma Reesei) For Effective Wastewater Treatment And Bio-Oil Production, Anshuman Bhanja, Gauri P. Minde, Sandip S. Magdum, Kalyanraman V.
Comparative Studies Of Oleaginous Fungal Strains (Mucor Circinelloides And Trichoderma Reesei) For Effective Wastewater Treatment And Bio-Oil Production, Anshuman Bhanja, Gauri P. Minde, Sandip S. Magdum, Kalyanraman V.
Sandip S. Magdum
Biological wastewater treatment typically requires the use of bacteria for degradation of carbonaceous and nitrogenous compounds present in wastewater. The high lipid containing biomass can be used to extract oil and the contents can be termed as bio-oil (or biodiesel or myco-diesel after transesterification). The separate experiments were conducted on actual wastewater samples with 5% v/v inoculum of Mucor circinelloides MTCC1297 and Trichoderma reesei NCIM992 strains. The observed reductions in chemical oxygen demand (COD) were 88.72% and 86.75% in 96 hrs and the observed substrate based biomass yields were 0.21 mg VSS/mg COD and 0.22 mg VSS/mg COD for M. …
Microbe-Mineral Relationships And Biogenic Mineral Transformations In Actively Venting Deep-Sea Hydrothermal Sulfide Chimneys, Tzihsuan J. Lin
Microbe-Mineral Relationships And Biogenic Mineral Transformations In Actively Venting Deep-Sea Hydrothermal Sulfide Chimneys, Tzihsuan J. Lin
TZIHSUAN J LIN
This dissertation uses a combination of microbiology, mineralogy, and geochemistry to understand dissimilatory iron reduction in hyperthermophilic archaea and the role and potential impact of these and other vent microorganisms within active deep-sea hydrothermal vent chimneys. The central objective of the dissertation is to determine if mineral composition and chimney type are among the primary determinants of microbial community composition and hyperthermophilic, dissimilatory iron reducer growth, in addition to other environmental factors such as nutrient availability, temperature, pH, and chlorinity. This is done using samples and organisms collected from the Endeavour Segment of the Juan de Fuca Ridge in the …
Chromium Reducing And Plant Growth Promoting Novel Strain Pseudomonas Aeruginosa Osg41 Enhance Chickpea Growth In Chromium Amended Soils, Mohammad Oves
Mohammad Oves
No abstract provided.
An Efficient Biotreatment Process For Polyvinyl Alcohol Containing Textile Wastewater, Sandip S. Magdum, Gauri P. Minde, Upendra S. Adhyapak, Kalyanraman V.
An Efficient Biotreatment Process For Polyvinyl Alcohol Containing Textile Wastewater, Sandip S. Magdum, Gauri P. Minde, Upendra S. Adhyapak, Kalyanraman V.
Sandip S. Magdum
The aim of this work was to optimize the biodegradation of polyvinyl alcohol (PVA) containing actual textile wastewater for a sustainable treatment solution. The isolated microbial consortia of effective PVA degrader namely Candida Sp. and Pseudomonas Sp., which were responsible for symbiotic degradation of chemical oxidation demand (COD) and PVA from desizing wastewater. In the process optimization, the maximum aeration was essential to achieve a high degradation rate, where as stirring enhances further degradation and foam control. Batch experiments concluded with the need of 16 lpm/l and 150 rpm of air and stirring speed respectively for high rate of COD …
Development Of A Novel Inoculum Preparation Method For Solid-State Fermentation - Cellophane Film Culture (Cfc) Technique, Teck Nam Ang, Gek Cheng Ngoh, Adeline Seak May Chua
Development Of A Novel Inoculum Preparation Method For Solid-State Fermentation - Cellophane Film Culture (Cfc) Technique, Teck Nam Ang, Gek Cheng Ngoh, Adeline Seak May Chua
Teck Nam Ang Dr.
This study reports a user-friendly technique in the preparation of fungal inoculum intended for solid-state fermentation (SSF) – Cellophane Film Culture (CFC) technique. This technique uses cellophane film-overlaid agar plates to facilitate the separation of fungal biomass. The findings showed that inoculum of P. sajor-caju produced is viable, and it was confirmed by the presence of laccase enzyme activity in SSF of rice husk. The correlation between fungal dry and wet weights (r2 = 0.9329) provides an accurate estimation of fungal dry weight from its wet weight during inoculum preparation. Besides, this technique does not require a strict sterile handling …
Predominant Archaea In Marine Sediments Degrade Detrital Proteins, Karen Lloyd, Lars Schreiber, Dorthe G. Petersen, Kasper U. Kjeldsen, Mark A. Lever, Andrew D. Steen, Ramunus Stepanauskas, Michael Richter, Sara Kleindienst, Sabine Lenk, Andreas Schramm, Bo Barker Jørgensen
Predominant Archaea In Marine Sediments Degrade Detrital Proteins, Karen Lloyd, Lars Schreiber, Dorthe G. Petersen, Kasper U. Kjeldsen, Mark A. Lever, Andrew D. Steen, Ramunus Stepanauskas, Michael Richter, Sara Kleindienst, Sabine Lenk, Andreas Schramm, Bo Barker Jørgensen
Karen Lloyd
Half of the microbial cells in the Earth’s oceans are found in sediments. Many of these cells are members of the Archaea, singlecelled prokaryotes in a domain of life separate from Bacteria and Eukaryota. However, most of these archaea lack cultured representatives, leaving their physiologies and placement on the tree of life uncertain. Here we show that the uncultured miscellaneous crenarchaeotal group (MCG) and marine benthic group-D (MBG-D) are among the most numerous archaea in the marine sub-sea floor. Single-cell genomic sequencing of one cell of MCG and three cells of MBG-D indicated that they form new branches basal to …
Biosorption Of Heavy Metals By Bacillus Thuringiensis Strain Osm29 Originating From Industrial Effluent Contaminated North Indian Soil, Mohammad Oves
Biosorption Of Heavy Metals By Bacillus Thuringiensis Strain Osm29 Originating From Industrial Effluent Contaminated North Indian Soil, Mohammad Oves
Mohammad Oves
No abstract provided.
Desiccation Induces Viable But Non-Culturable Cells In Sinorhizobium Meliloti 1021, Jan A.C. Vriezen Dr., Frans J. Debruijn Dr., Klaus R. Nusslein Dr.
Desiccation Induces Viable But Non-Culturable Cells In Sinorhizobium Meliloti 1021, Jan A.C. Vriezen Dr., Frans J. Debruijn Dr., Klaus R. Nusslein Dr.
Jan A.C. Vriezen Dr.
Sinorhizobium meliloti is a microorganism commercially used in the production of e.g. Medicago sativa seed inocula. Many inocula are powder-based and production includes a drying step. Although S. meliloti survives drying well, the quality of the inocula is reduced during this process. In this study we determined survival during desiccation of the commercial strains 102F84 and 102F85 as well as the model strain USDA1021. The survival of S. meliloti 1021 was estimated during nine weeks at 22% relative humidity. We found that after an initial rapid decline of colony forming units, the decline slowed to a steady 10-fold reduction in …
Anaerobic Oxidation Of Methane At Different Temperature Regimes In Guaymas Basin Hydrothermal Sediments, Jennifer F. Biddle, Zena Cardman, Howard Mendlovitz, Daniel B. Albert, Karen G. Lloyd, Karen Lloyd, Antje Boetius, Andreas Teske
Anaerobic Oxidation Of Methane At Different Temperature Regimes In Guaymas Basin Hydrothermal Sediments, Jennifer F. Biddle, Zena Cardman, Howard Mendlovitz, Daniel B. Albert, Karen G. Lloyd, Karen Lloyd, Antje Boetius, Andreas Teske
Karen Lloyd
Anaerobic oxidation of methane (AOM) was investigated in hydrothermal sediments of Guaymas Basin based on d13C signatures of CH4, dissolved inorganic carbon and porewater concentration profiles of CH4 and sulfate. Cool, warm and hot in-situ temperature regimes (15–20 1C, 30–35 1C and 70–95 1C) were selected from hydrothermal locations in Guaymas Basin to compare AOM geochemistry and 16S ribosomal RNA (rRNA), mcrA and dsrAB genes of the microbial communities. 16S rRNA gene clone libraries from the cool and hot AOM cores yielded similar archaeal types such as Miscellaneous Crenarchaeotal Group, Thermoproteales and anaerobic methane-oxidizing archaea (ANME)-1; some of the ANME-1 …
Archaea Of The Miscellaneous Crenarchaeotal Group (Mcg) Are Abundant, Diverse, And Widespread In Marine Sediments, Kyoko Kubo, Karen Lloyd, Jennifer F. Biddle, Rudolf Amann, Andreas Teske, Katrin Knittel
Archaea Of The Miscellaneous Crenarchaeotal Group (Mcg) Are Abundant, Diverse, And Widespread In Marine Sediments, Kyoko Kubo, Karen Lloyd, Jennifer F. Biddle, Rudolf Amann, Andreas Teske, Katrin Knittel
Karen Lloyd
Members of the highly diverse Miscellaneous Crenarchaeotal Group (MCG) are globally distributed in various marine and continental habitats. In this study, we applied a polyphasic approach (rRNA slot blot hybridization, quantitative PCR (qPCR) and catalyzed reporter deposition FISH) using newly developed probes and primers for the in situ detection and quantification of MCG crenarchaeota in diverse types of marine sediments and microbial mats. In general, abundance of MCG (cocci, 0.4 lm) relative to other archaea was highest (12–100%) in anoxic, low-energy environments characterized by deeper sulfate depletion and lower microbial respiration rates (P¼0.06 for slot blot and P¼0.05 for qPCR). …
Environmental Evidence For Net Methane Production And Oxidation In Putative Anaerobic Methanotrophic (Anme) Archaeaemi_, Karen Lloyd, Marc J. Alperin, Andreas Teske
Environmental Evidence For Net Methane Production And Oxidation In Putative Anaerobic Methanotrophic (Anme) Archaeaemi_, Karen Lloyd, Marc J. Alperin, Andreas Teske
Karen Lloyd
Uncultured ANaerobic MEthanotrophic (ANME) archaea are often assumed to be obligate methanotrophs that are incapable of net methanogenesis, and are therefore used as proxies for anaerobic methane oxidation in many environments in spite of uncertainty regarding their metabolic capabilities. Anaerobic methane oxidation regulates methane emissions in marine sediments and appears to occur through a reversal of a methane-producing metabolism. We tested the assumption that ANME are obligate methanotrophs by detecting and quantifying gene transcription of ANME-1 across zones of methane oxidation versus methane production in sediments from the White Oak River estuary, North Carolina. ANME-1 consistently transcribe 16S rRNA and …
Niche Of Harmful Alga Aureococcus Anophagefferens Revealed Through Ecogenomics, Christopher Gobler, Dianna Berry, Sonya Dyhrman, Steven Wilhelm
Niche Of Harmful Alga Aureococcus Anophagefferens Revealed Through Ecogenomics, Christopher Gobler, Dianna Berry, Sonya Dyhrman, Steven Wilhelm
Steven Wilhelm
Harmful algal blooms (HABs) cause significant economic and ecological damage worldwide. Despite considerable efforts, a comprehensive understanding of the factors that promote these blooms has been lacking, because the biochemical pathways that facilitate their dominance relative to other phytoplankton within specific environments have not been identified. Here, biogeochemical measurements showed that the harmful alga Aureococcus anophagefferens outcompeted co-occurring phytoplankton in estuaries with elevated levels of dissolved organic matter and turbidity and low levels of dissolved inorganic nitrogen. We subsequently sequenced the genome of A. anophagefferens and compared its gene complement with those of six competing phytoplankton species identified through metaproteomics. …
Diversity Of Oligotrichia And Choreotrichia Ciliates In Coastal Marine Sediments And In Overlying Plankton, Jan A.C. Vriezen Dr., Mary Doherty Dr., Maiko Tamura Dr., George B. Mcmanus Dr.
Diversity Of Oligotrichia And Choreotrichia Ciliates In Coastal Marine Sediments And In Overlying Plankton, Jan A.C. Vriezen Dr., Mary Doherty Dr., Maiko Tamura Dr., George B. Mcmanus Dr.
Jan A.C. Vriezen Dr.
Elucidating the relationship between ciliate communities in the benthos and the plankton is critical to understanding ciliate diversity in marine systems. Although data for many lineages are sparse, at least some members of the dominant marine ciliate clades Oligotrichia and Choreotrichia can be found in both plankton and benthos, in the latter either as cysts or active forms. In this study, we developed a molecular approach to address the relationship between the diversity of ciliates in the plankton and those of the underlying benthos in the same locations. Samples from plankton and sediments were compared across three sites along the …
Quantitativepcrmethods Forrna Anddnainmarine Sediments: Maximizing Yieldwhile Overcoming Inhibition, Karen Lloyd, Barbara J. Macgregor, Andreas Teske
Quantitativepcrmethods Forrna Anddnainmarine Sediments: Maximizing Yieldwhile Overcoming Inhibition, Karen Lloyd, Barbara J. Macgregor, Andreas Teske
Karen Lloyd
For accurate quantification of DNA and RNA from environmental samples, yield loss during nucleic acid purification has to be minimized. Quantitative PCR (qPCR) and reverse transcription (RT)-qPCR require a trade-off between maximizing yield and removing inhibitors. We compared DNA and RNA yield and suitability for quantitative SYBR Green PCR and RT-PCR using the UltraClean and PowerSoil extraction kits and a bead-beating protocol with phenol/chloroform extraction steps. Purification methods included silica-column-based procedures from the MoBio kits, RNeasy MinElute, WizardPlus miniprep columns, and an acrylamide gel extraction. DNA and RNA purification with WizardPlus and RNeasy, respectively, led to significant losses of nucleic …
Spatial Structure And Activity Of Sedimentary Microbial Communities Underlying A Beggiatoa Spp. Mat In A Gulf Of Mexico Hydrocarbon Seep, Karen Lloyd, Daniel B. Albert, Jennifer F. Biddle, Jeffrey P. Chanton, Oscar Pizarro, Andreas Teske
Spatial Structure And Activity Of Sedimentary Microbial Communities Underlying A Beggiatoa Spp. Mat In A Gulf Of Mexico Hydrocarbon Seep, Karen Lloyd, Daniel B. Albert, Jennifer F. Biddle, Jeffrey P. Chanton, Oscar Pizarro, Andreas Teske
Karen Lloyd
Background Subsurface fluids from deep-sea hydrocarbon seeps undergo methane- and sulfur-cycling microbial transformations near the sediment surface. Hydrocarbon seep habitats are naturally patchy, with a mosaic of active seep sediments and non-seep sediments. Microbial community shifts and changing activity patterns on small spatial scales from seep to non-seep sediment remain to be examined in a comprehensive habitat study. Methodology/Principal Findings We conducted a transect of biogeochemical measurements and gene expression related to methane- and sulfur-cycling at different sediment depths across a broad Beggiatoa spp. mat at Mississippi Canyon 118 (MC118) in the Gulf of Mexico. High process rates within the …
Determining Rates Of Virus Production In Aquatic Systems By The Virus Reduction Approach,, M.G. Weinbauer, J.M. Rowe, Steven Wilhelm
Determining Rates Of Virus Production In Aquatic Systems By The Virus Reduction Approach,, M.G. Weinbauer, J.M. Rowe, Steven Wilhelm
Steven Wilhelm
The reduction approach to assess virus production and the prokaryotic mortality by viral lysis stops new infection by reducing total virus abundance (and thus virus–host contacts). This allows for easy enumeration of viruses that originate from lysis of already infected cells due to the decreased abundance of free virus particles. This reoccurrence can be quantified and used to assess production and cell lysis rates. Several modifications of the method are presented and compared. The approaches have great potential for elucidating trends in virus production rates as well as for making generalized estimates of the quantitative effects of viruses on marine …
The Construction And Analysis Of Marker Gene Libraries, S.M. Short, F. Chen, Steven Wilhelm
The Construction And Analysis Of Marker Gene Libraries, S.M. Short, F. Chen, Steven Wilhelm
Steven Wilhelm
Marker genes for viruses are typically amplified from aquatic samples to determine whether specific viruses are present in the sample, or to examine the diversity of a group of related viruses. In this chapter, we will provide an overview of common methods used to amplify, clone, sequence, and analyze virus marker genes, and will focus our discussion on viruses infecting algae, bacteria, and heterotrophic flagellates. Within this chapter, we endeavor to highlight critical aspects and components of these methods. To this end, instead of providing a detailed experimental protocol for each of the steps involved in examining virus marker gene …
Metabolic Variability In Seafloor Brines Revealed By Carbon And Sulphur Dynamics, Samantha B. Joye, Vladimir A. Samarkin, Beth! N. Orcutt, Ian R. Macdonald, Kai-Uwe Hinrichs, Marcus Elvert, Andreas P. Teske, Karen Lloyd, Mark A. Lever, Joseph P. Montoya, Christof D. Meile
Metabolic Variability In Seafloor Brines Revealed By Carbon And Sulphur Dynamics, Samantha B. Joye, Vladimir A. Samarkin, Beth! N. Orcutt, Ian R. Macdonald, Kai-Uwe Hinrichs, Marcus Elvert, Andreas P. Teske, Karen Lloyd, Mark A. Lever, Joseph P. Montoya, Christof D. Meile
Karen Lloyd
Brine fluids that upwell from deep, hot reservoirs below the sea bed supply the sea floor with energy-rich substrates and nutrients that are used by diverse microbial ecosystems. Contemporary hypersaline environments formed by brine seeps may provide insights into the metabolism and distribution of microorganisms on the early Earth or on extraterrestrial bodies. Here we use geochemical and genetic analyses to characterize microbial community composition and metabolism in two seafloor brines in the Gulf of Mexico: an active mud volcano and a quiescent brine pool. Both brine environments are anoxic and hypersaline. However, rates of sulphate reduction and acetate production …
The Evolution Of Reduced Microbial Killing, Jan A.C. Vriezen Dr., Michael Valliere, Margaret A. Riley Dr.
The Evolution Of Reduced Microbial Killing, Jan A.C. Vriezen Dr., Michael Valliere, Margaret A. Riley Dr.
Jan A.C. Vriezen Dr.
Bacteria engage in a never-ending arms race in which they compete for limited resources and niche space. The outcome of this intense interaction is the evolution of a powerful arsenal of biological weapons. Perhaps the most studied of these are colicins, plasmid-based toxins produced by and active against Escherichia coli. The present study was designed to explore the molecular responses of a colicin-producing strain during serial transfer evolution. What evolutionary changes occur when colicins are produced with no target present? Can killing ability be maintained in the absence of a target? To address these, and other, questions, colicinogenic strains and …
Actinorhodopsin Genes Discovered Diverse In Freshwater Habitats And Among Cultivated Actinobacteria, A.K. Sharma, K. Sommerfeld, G.S. Bullerjahn, A.R. Matteson, Steven Wilhelm, J. Jezbera, U. Brandt, W.F. Doolittle, M.W. Hahn
Actinorhodopsin Genes Discovered Diverse In Freshwater Habitats And Among Cultivated Actinobacteria, A.K. Sharma, K. Sommerfeld, G.S. Bullerjahn, A.R. Matteson, Steven Wilhelm, J. Jezbera, U. Brandt, W.F. Doolittle, M.W. Hahn
Steven Wilhelm
Microbial rhodopsins are membrane proteins that utilize a retinal chromophore to harvest sunlight for energetic and photosensory functions. Recently, a group of novel rhodopsin sequences named ‘actinorhodopsins’ (ActRs) was hypothesized to exist among uncultured planktonic Actinobacteria. ActRs were discovered by mining metagenomic data obtained during the Venter Institute’s Global Ocean Sampling expedition, from a hypersaline lagoon, two estuaries and a freshwater lake. On the basis of these findings, and many studies that show Actinobacteria are common inhabitants of lakes, we predicted that ActR genes would likely be present in other freshwater habitats and among the genomes of cultivated Actinobacteria …
Identifying The Source Of Unknown Microcystin Genes And Predicting Microcystin Variants By Comparing Genes Within Uncultured Cyanobacterial Cells, C.J. Allender, G.R. Lecleir, J.M. Rinta-Kanto, R.L. Small, M.F. Satchwell, G.L. Boyer, Steven Wilhelm
Identifying The Source Of Unknown Microcystin Genes And Predicting Microcystin Variants By Comparing Genes Within Uncultured Cyanobacterial Cells, C.J. Allender, G.R. Lecleir, J.M. Rinta-Kanto, R.L. Small, M.F. Satchwell, G.L. Boyer, Steven Wilhelm
Steven Wilhelm
While multiple phylogenetic markers have been used in the culture independent study of microcystin producing cyanobacteria, in only a few instances have multiple markers been studied within individual cells, and in all cases these studies have been conducted with cultured isolates. Here, we isolate and evaluate large DNA fragments (> 6 kb) encompassing two genes involved in microcystin biosynthesis (mcyA2 and mcyB1) and use them to identify the source of gene fragments found in water samples. Further investigation of these gene loci from individual cyanobacterial cells allowed for improved analysis of the genetic diversity within microcystin producers as …
Distribution Of Calcifying And Silicifying Phytoplankton In Relation To Environmental And Biogeochemical Parameters During The Late Stages Of The 2005 North East Atlantic Spring Bloom, K. Leblanc, C.E. Hare, Y. Feng, G.M. Berg, G.R. Ditullio, A. Neeley, I. Benner, C. Sprengel, A. Beck, S.A. Sanudo-Wilhemy, U. Passow, K. Klinck, J.M. Rowe, Steven Wilhelm, C.W. Brown, D.A. Hutchins
Distribution Of Calcifying And Silicifying Phytoplankton In Relation To Environmental And Biogeochemical Parameters During The Late Stages Of The 2005 North East Atlantic Spring Bloom, K. Leblanc, C.E. Hare, Y. Feng, G.M. Berg, G.R. Ditullio, A. Neeley, I. Benner, C. Sprengel, A. Beck, S.A. Sanudo-Wilhemy, U. Passow, K. Klinck, J.M. Rowe, Steven Wilhelm, C.W. Brown, D.A. Hutchins
Steven Wilhelm
The late stage of the North East Atlantic (NEA) spring bloom was investigated during June 2005 along a transect section from 45 to 66° N between 15 and 20° W in order to characterize the contribution of siliceous and calcareous phytoplankton groups and describe their distribution in relation to environmental factors. We measured several biogeochemical parameters such as nutrients, surface trace metals, algal pigments, biogenic silica (BSi), particulate inorganic carbon (PIC) or calcium carbonate, particulate organic carbon, nitrogen and phosphorus (POC, PON and POP, respectively), as well as transparent exopolymer particles (TEP). Results were compared with other studies undertaken in …
The Effects Of Increased Pco2 And Temperature On The North Atlantic Spring Bloom: I. The Phytoplankton Community And Biogeochemical Response, Y. Feng, C.E. Hare, K. Leblanc, J.M. Rose, Y Zhang, G.R. Ditullio, P. Lee, Steven Wilhelm, J.M. Rowe, J. Sun, N. Nemcek, C. Gueguen, U. Passow, I. Benner, C. Brown, D.A. Hutchins
The Effects Of Increased Pco2 And Temperature On The North Atlantic Spring Bloom: I. The Phytoplankton Community And Biogeochemical Response, Y. Feng, C.E. Hare, K. Leblanc, J.M. Rose, Y Zhang, G.R. Ditullio, P. Lee, Steven Wilhelm, J.M. Rowe, J. Sun, N. Nemcek, C. Gueguen, U. Passow, I. Benner, C. Brown, D.A. Hutchins
Steven Wilhelm
ABSTRACT: The North Atlantic spring bloom is one of the largest annual biological events in the ocean, and is characterized by dominance transitions from siliceous (diatoms) to calcareous (coccolithophores) algal groups. To study the effects of future global change on these phytoplankton and the biogeochemical cycles they mediate, a shipboard continuous culture experiment (Ecostat) was conducted in June 2005 during this transition period. Four treatments were examined: (1) 12°C and 390 ppm CO2 (ambient control), (2) 12°C and 690 ppm CO2 (high pCO2), (3) 16°C and 390 ppm CO2 (high temperature), and (4) 16°C and …
Effects Of Increased Pco2 And Temperature On The North Atlantic Spring Bloom: Iii. Dimethylsulfoniopropionate, P.A. Lee, J.R. Rudisill, A.R. Neeley, D.A. Hutchins, Y. Feng, C.E. Hare, K. Leblanc, J.M. Rose, Steven Wilhelm, J.M. Rowe, G.R. Ditullio
Effects Of Increased Pco2 And Temperature On The North Atlantic Spring Bloom: Iii. Dimethylsulfoniopropionate, P.A. Lee, J.R. Rudisill, A.R. Neeley, D.A. Hutchins, Y. Feng, C.E. Hare, K. Leblanc, J.M. Rose, Steven Wilhelm, J.M. Rowe, G.R. Ditullio
Steven Wilhelm
The CLAW hypothesis argues that a negative feedback mechanism involving phytoplankton-derived dimethylsulfoniopropionate (DMSP) could mitigate increasing sea surface temperatures that result from global warming. DMSP is converted to the climatically active dimethylsulfide (DMS), which is transferred to the atmosphere and photochemically oxidized to sulfate aerosols, leading to increases in planetary albedo and cooling of the Earth’s atmosphere. A shipboard incubation experiment was conducted to investigate the effects of increased temperature and pCO2 on the algal community structure of the North Atlantic spring bloom and their subsequent impact on particulate and dissolved DMSP concentrations (DMSPp and DMSPd). Under …
Cross-Talk In The Gut, Jennifer E. Dinalo, David A. Relman
Cross-Talk In The Gut, Jennifer E. Dinalo, David A. Relman
Jennifer E. Dinalo
Modulation of host signaling by the products of microbial activity in the gut may affect weight gain and fat formation.
The Role Of Sos Boxes In Enteric Bacteriocin Regulation, Jan A.C. Vriezen Dr., Osnat Gillor Dr., Margaret A. Riley Dr.
The Role Of Sos Boxes In Enteric Bacteriocin Regulation, Jan A.C. Vriezen Dr., Osnat Gillor Dr., Margaret A. Riley Dr.
Jan A.C. Vriezen Dr.
Bacteriocins are a large and functionally diverse family of toxins found in all major lineages of Bacteria. Colicins, those bacteriocins produced by Escherichia coli, serve as a model system for investigations of bacteriocin structure–function relationships, genetic organization, and their ecological role and evolutionary history. Colicin expression is often dependent on host regulatory pathways (such as the SOS system), is usually confined to times of stress, and results in death of the producing cells. This study investigates the role of the SOS system in mediating this unique form of toxin expression. A comparison of all the sequenced enteric bacteriocin promoters reveals …
Responses Of Rhizobia To Desiccation In Relation To Osmotic Stress, Oxygen, And Temperature, Jan A.C. Vriezen Dr., Frans J. Debruijn Dr., Klaus R. Nusslein Dr.
Responses Of Rhizobia To Desiccation In Relation To Osmotic Stress, Oxygen, And Temperature, Jan A.C. Vriezen Dr., Frans J. Debruijn Dr., Klaus R. Nusslein Dr.
Jan A.C. Vriezen Dr.
No abstract provided.
An Anaerobic Methane Oxidizing Community Of Anme-1b Archaea In Hypersaline Gulf Of Mexico Sediments, Karen Lloyd, Laura Lapham, Andreas Teske
An Anaerobic Methane Oxidizing Community Of Anme-1b Archaea In Hypersaline Gulf Of Mexico Sediments, Karen Lloyd, Laura Lapham, Andreas Teske
Karen Lloyd
Sediments overlying a brine pool methane seep in the Gulf of Mexico (Green Canyon 205) were analyzed using molecular and geochemical approaches to identify geochemical controls on microbial community composition and stratification. 16S rRNA gene and rRNA clone libraries, as well as mcrA gene clone libraries, showed that the archaeal community consists predominantly of ANME-1b methane oxidizers; no archaea of other ANME subgroups were found with general and group-specific PCR primers. The ANME-1b community was found in the sulfate-methane interface, where undersaturated methane concentrations of ca. 100 to 250 _M coexist with sulfate concentrations around 10 mM. Clone libraries of …