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Articles 1 - 25 of 25
Full-Text Articles in Entire DC Network
A Comparison Of Adenosine Triphosphate With Other Metrics Of Microbial Biomass In A Gradient From The North Atlantic To The Chesapeake Bay, Alexander B. Bochdansky, Amber A. Beecher, Joshua R. Calderon, Alison N. Stouffer, Nyjaee N. Washington
A Comparison Of Adenosine Triphosphate With Other Metrics Of Microbial Biomass In A Gradient From The North Atlantic To The Chesapeake Bay, Alexander B. Bochdansky, Amber A. Beecher, Joshua R. Calderon, Alison N. Stouffer, Nyjaee N. Washington
OES Faculty Publications
A new, simplified protocol for determining particulate adenosine triphosphate (ATP) levels allows for the assessment of microbial biomass distribution in aquatic systems at a high temporal and spatial resolution. A comparison of ATP data with related variables, such as particulate carbon, nitrogen, chlorophyll, and turbidity in pelagic samples, yielded significant and strong correlations in a gradient from the tributaries of the Chesapeake Bay (sigma-t = 8) to the open North Atlantic (sigma-t = 29). Correlations varied between ATP and biomass depending on the microscopic method employed. Despite the much greater effort involved, biomass determined by microscopy correlated poorly with other …
Fine-Scale Genetic Structure In Rhizosphere Microbial Communities Associated With Chamaecrista Fasciculata (Fabaceae), Mahboubeh Hosseinalizadeh Nobarinezhad, Lisa E. Wallace
Fine-Scale Genetic Structure In Rhizosphere Microbial Communities Associated With Chamaecrista Fasciculata (Fabaceae), Mahboubeh Hosseinalizadeh Nobarinezhad, Lisa E. Wallace
Biological Sciences Faculty Publications
Soil microbiota of the rhizosphere are an important extension of the plant phenotype because they impact the health and fitness of host plants. The composition of these communities is expected to differ among host plants due to influence by host genotype. Given that many plant populations exhibit fine-scale genetic structure (SGS), associated microbial communities may also exhibit SGS. In this study, we tested this hypothesis using Chamaecrista fasciculata, a legume species that has previously been determined to have significant SGS. We collected genetic data from prokaryotic and fungal rhizosphere communities in association with 70 plants in an area of …
Nitrite Cycling In The Primary Nitrite Maxima Of The Eastern Tropical North Pacific, Nicole M. Travis, Colette L. Kelly, Margaret R. Mulholland, Karen L. Casciotti
Nitrite Cycling In The Primary Nitrite Maxima Of The Eastern Tropical North Pacific, Nicole M. Travis, Colette L. Kelly, Margaret R. Mulholland, Karen L. Casciotti
OES Faculty Publications
The primary nitrite maximum (PNM) is a ubiquitous feature of the upper ocean, where nitrite accumulates in a sharp peak at the base of the euphotic zone. This feature is situated where many chemical and hydrographic properties have strong gradients and the activities of several microbial processes overlap. Near the PNM, four major microbial processes are active in nitrite cycling: ammonia oxidation, nitrite oxidation, nitrate reduction and nitrite uptake. The first two processes are mediated by the nitrifying archaeal/bacterial community, while the second two processes are primarily conducted by phytoplankton. The overlapping spatial habitats and substrate requirements for these microbes …
Drivers Of 20th Century Sea-Level Change In Southern New Zealand Determined From Proxy And Instrumental Records, Ed Garrett, W. Roland Gehrels, Bruce W. Hayward, Rewi Newnham, Maria J. Gehrels, Craig J. Morey, Sönke Dangendorf
Drivers Of 20th Century Sea-Level Change In Southern New Zealand Determined From Proxy And Instrumental Records, Ed Garrett, W. Roland Gehrels, Bruce W. Hayward, Rewi Newnham, Maria J. Gehrels, Craig J. Morey, Sönke Dangendorf
CCPO Publications
In this paper we present new proxy-based sea-level reconstructions for southern New Zealand spanning the last millennium. These palaeo sea-level records usefully complement sparse Southern Hemisphere proxy and tide-gauge sea-level datasets and, in combination with instrumental observations, can test hypotheses about the drivers of 20th century global sea-level change, including land-based ice melt and regional sterodynamics. We develop sea-level transfer functions from regional datasets of salt-marsh foraminifera to establish a new proxy-based sea-level record at Mokomoko Inlet, at the southern tip of the South Island, and to improve the previously published sea-level reconstruction at Pounawea, located about 110 km to …
Defining The Realized Niche Of The Two Major Clades Of Trichodesmium: A Study On The West Florida Shelf, Kristina A. Confesor, Corday R. Selden, Kimberly E. Powell, Laura A. Donahue, Travis Mellett, Salvatore Caprara, Angela N. Knapp, Kristen N. Buck, P. Dreux Chappell
Defining The Realized Niche Of The Two Major Clades Of Trichodesmium: A Study On The West Florida Shelf, Kristina A. Confesor, Corday R. Selden, Kimberly E. Powell, Laura A. Donahue, Travis Mellett, Salvatore Caprara, Angela N. Knapp, Kristen N. Buck, P. Dreux Chappell
OES Faculty Publications
The cyanobacterium Trichodesmium plays an essential role supporting ocean productivity by relieving nitrogen limitation via dinitrogen (N-2) fixation. The two common Trichodesmium clades, T. erythraeum and T. thiebautii, are both observed in waters along the West Florida Shelf (WFS). We hypothesized that these taxa occupy distinct realized niches, where T. thiebautii is the more oceanic clade. Samples for DNA and water chemistry analyses were collected on three separate WFS expeditions (2015, 2018, and 2019) spanning multiple seasons; abundances of the single copy housekeeping gene rnpB from both clades were enumerated via quantitative PCR. We conducted a suite of statistical …
Evidence For Metabolic Diversity In Meso-Neoproterozoic Stromatolites (Vazante Group, Brazil), Flavia Callefo, Fresia Ricardi-Branco, Mirian Mírian Liza Alves Forancelli Pacheco, Alexandre Ribeiro Cardoso, Nora Noffke, Verônica De Carvalho Teixeira, Itamar Tomio Neckel, Lara Maldanis, Emma Bullock, Dina Bower, Adalene Moreira Silva, Dario Ferreira Sanchez, Fabio Rodrigues, Douglas Galante
Evidence For Metabolic Diversity In Meso-Neoproterozoic Stromatolites (Vazante Group, Brazil), Flavia Callefo, Fresia Ricardi-Branco, Mirian Mírian Liza Alves Forancelli Pacheco, Alexandre Ribeiro Cardoso, Nora Noffke, Verônica De Carvalho Teixeira, Itamar Tomio Neckel, Lara Maldanis, Emma Bullock, Dina Bower, Adalene Moreira Silva, Dario Ferreira Sanchez, Fabio Rodrigues, Douglas Galante
OES Faculty Publications
Deciphering the evolution of ecological interactions among the metabolic types during the early diversification of life on Earth is crucial for our understanding of the ancient biosphere. The stromatolites from the genus Conophyton cylindricus represent a datum for the Proterozoic (Meso to Neoproterozoic) on Earth. Their typical conical shape has been considered a result of a competition between microorganisms for space, light and nutrients. Well-preserved records of this genus from the "Paleontological Site of Cabeludo ", Vazante Group, São Francisco Craton (Southern Brazil) present in situ fossilized biofilms, containing preserved carbonaceous matter. Petrographic and geochemical analyses revealed an alternation between …
Microbial Labilization And Diversification Of Pyrogenic Dissolved Organic Matter, Aleksandar I. Goranov, Andrew S. Wozniak, Kyle W. Bostick, Andrew R. Zimmerman, Siddhartha Mitra, Patrick G. Hatcher
Microbial Labilization And Diversification Of Pyrogenic Dissolved Organic Matter, Aleksandar I. Goranov, Andrew S. Wozniak, Kyle W. Bostick, Andrew R. Zimmerman, Siddhartha Mitra, Patrick G. Hatcher
Chemistry & Biochemistry Faculty Publications
With the increased occurrence of wildfires around the world, interest in the chemistry of pyrogenic organic matter (pyOM) and its fate in the environment has increased. Upon leaching from soils by rain events, significant amounts of dissolved pyOM (pyDOM) enter the aquatic environment and interact with microbial communities that are essential for cycling organic matter within the different biogeochemical cycles. To evaluate the biodegradability of pyDOM, aqueous extracts of laboratory-produced biochars were incubated with soil microbes, and the molecular changes to the composition of pyDOM were probed using ultrahigh-resolution mass spectrometry (Fourier transform–ion cyclotron resonance–mass spectrometry). Given that solar irradiation …
Isothermal Environmental Heat Energy Utilization By Transmembrane Electrostatically Localized Protons At The Liquid-Membrane Interface, James Weifu Lee
Isothermal Environmental Heat Energy Utilization By Transmembrane Electrostatically Localized Protons At The Liquid-Membrane Interface, James Weifu Lee
Chemistry & Biochemistry Faculty Publications
This study employing the latest theory on transmembrane electrostatic proton localization has now, for the first time, consistently elucidated a decades-longstanding bioenergetic conundrum in alkalophilic bacteria and more importantly discovered an entirely new feature: isothermal environmental heat utilization by electrostatically localized protons at the liquid-membrane interface. It was surprisingly revealed that the protonic motive force (equivalent to Gibbs free energy) from the isothermal environmental heat energy utilization through the electrostatically localized protons is not constrained by the overall energetics of the redox-driven proton pump system because of the following: (a) the transmembrane electrostatically localized protons are not free to move …
The Contribution Of Marine Aggregate-Associated Bacteria To The Accumulation Of Pathogenic Bacteria In Oysters: An Agent-Based Model, Andrew M. Kramer, J. Evan Ward, Fred C. Dobbs, Melissa L. Pierce
The Contribution Of Marine Aggregate-Associated Bacteria To The Accumulation Of Pathogenic Bacteria In Oysters: An Agent-Based Model, Andrew M. Kramer, J. Evan Ward, Fred C. Dobbs, Melissa L. Pierce
OES Faculty Publications
Bivalves process large volumes of water, leading to their accumulation of bacteria, including potential human pathogens (e.g., vibrios). These bacteria are captured at low efficiencies when freely suspended in the water column, but they also attach to marine aggregates, which are captured with near 100% efficiency. For this reason, and because they are often enriched with heterotrophic bacteria, marine aggregates have been hypothesized to function as important transporters of bacteria into bivalves. The relative contribution of aggregates and unattached bacteria to the accumulation of these cells, however, is unknown. We developed an agent-based model to simulate accumulation of vibrio-type bacteria …
Ship Ballast Tanks: How Microbes Travel The World, Fred C. Dobbs
Ship Ballast Tanks: How Microbes Travel The World, Fred C. Dobbs
OES Faculty Publications
As the international shipping fleet travels the oceans, it carries with it hidden cargoes of microbes. Fred C. Dobbs explores the hazards posed and what can be done to counteract them.
Apres Le Deluge: Microbial Landscape Of New Orleans After The Hurricanes, Fred C. Dobbs
Apres Le Deluge: Microbial Landscape Of New Orleans After The Hurricanes, Fred C. Dobbs
OES Faculty Publications
No abstract provided.
Green Autofluorescence In Dinoflagellates, Diatoms, And Other Microalgae And Its Implications For Vital Staining And Morphological Studies, Ying Zhong Tang, Fred C. Dobbs
Green Autofluorescence In Dinoflagellates, Diatoms, And Other Microalgae And Its Implications For Vital Staining And Morphological Studies, Ying Zhong Tang, Fred C. Dobbs
OES Faculty Publications
Green autofluorescence (GAF) has been described in the short flagellum of golden and brown algae, the stigma of Euglenophyceae, and cytoplasm of different life stages of dinoflagellates and is considered by some researchers a valuable taxonomic feature for dinoflagellates. In addition, green fluorescence staining has been widely proposed or adopted to measure cell viability (or physiological state) in areas such as apoptosis of phytoplankton, pollutant stresses on algae, metabolic activity of algae, and testing treatment technologies for ships' ballast water. This paper reports our epifluorescence microscopic observations and quantitative spectrometric measurements of GAIT in a broad phylogenetic range of microalgae. …
High-Temperature Fluorescent In Situ Hybridization For Detecting Escherichia Coli In Seawater Samples, Using Rrna-Targeted Oligonucleotide Probes And Flow Cytometry, Ying Zhong Tang, Karina Yew Hoong Gin, Tok Hoon Lim
High-Temperature Fluorescent In Situ Hybridization For Detecting Escherichia Coli In Seawater Samples, Using Rrna-Targeted Oligonucleotide Probes And Flow Cytometry, Ying Zhong Tang, Karina Yew Hoong Gin, Tok Hoon Lim
OES Faculty Publications
Fluorescence in situ hybridization (FISH) is a widely used method to detect environmental microorganisms. The standard protocol is typically conducted at a temperature of 46°C and a hybridization time of 2 or 3 h, using the fluorescence signal intensity as the sole parameter to evaluate the performance of FISH. This paper reports our results for optimizing the conditions of FISH using rRNA-targeted oligonucleotide probes and flow cytometry and the application of these protocols to the detection of Escherichia coli in seawater spiked with E. coli culture. We obtained two types of optimized protocols for FISH, which showed rapid results with …
Transport Of The Harmful Bloom Alga Aureococcus Anophagefferens By Oceangoing Ships And Coastal Boats, Martina A. Doblin, Linda C. Popels, Kathryn J. Coyne, David A. Hutchins, S. Craig Cary, Fred C. Dobbs
Transport Of The Harmful Bloom Alga Aureococcus Anophagefferens By Oceangoing Ships And Coastal Boats, Martina A. Doblin, Linda C. Popels, Kathryn J. Coyne, David A. Hutchins, S. Craig Cary, Fred C. Dobbs
OES Faculty Publications
It is well established that cyst-forming phytoplankton species are transported in ships' ballast tanks. However, there is increasing evidence that other phytoplankton species which do not encyst are also capable of surviving ballast transit. These species have alternative modes of nutrition (hetero- or mixotrophy) and/or are able to survive long-term darkness. In our studies of no-ballast-on-board vessels arriving in the Great Lakes, we tested for the presence of the harmful algal bloom species Aureococcus anophagefferens (brown tide) in residual (i.e., unpumpable) ballast water using methods based on the PCR. During 2001, the brown tide organism was detected in 7 of …
Comparison Of Methods For Dna Isolation From Food Samples For Detection Of Shiga Toxin-Producing Escherichia Coli By Real-Time Pcr, Loree C. Heller, Carisa R. Davis, K. Kealy Peak, David Wingfield, Andrew C. Cannons, Philip T. Amuso, Jacqueline Cattani
Comparison Of Methods For Dna Isolation From Food Samples For Detection Of Shiga Toxin-Producing Escherichia Coli By Real-Time Pcr, Loree C. Heller, Carisa R. Davis, K. Kealy Peak, David Wingfield, Andrew C. Cannons, Philip T. Amuso, Jacqueline Cattani
Bioelectrics Publications
In this study, food samples were intentionally contaminated with Escherichia coli O157:H7, and then DNA was isolated by using four commercial kits. The isolated DNA samples were compared by using real-time PCR detection of the Shiga toxin genes. The four kits tested worked similarly.
Extended Tailing Of Bacteria Following Breakthrough At The Narrow Channel Focus Area, Oyster, Virginia, Pengfei Zhang, William P. Johnson, Timothy D. Scheibe, Keun-Hyung Choi, Fred C. Dobbs, Brian J. Mailloux
Extended Tailing Of Bacteria Following Breakthrough At The Narrow Channel Focus Area, Oyster, Virginia, Pengfei Zhang, William P. Johnson, Timothy D. Scheibe, Keun-Hyung Choi, Fred C. Dobbs, Brian J. Mailloux
OES Faculty Publications
Extended tailing of low bacterial concentrations following breakthrough at the Narrow Channel focus area was observed for 4 months. Bacterial attachment and detachment kinetics associated with breakthrough and extended tailing were determined by fitting a one-dimensional transport model to the field breakthrough-tailing data. Spatial variations in attachment rate coefficient (k(f)) were observed under forced gradient conditions (i.e., k(f) decreased as travel, distance increased), possibly because of decreased bacterial adhesion with increased transport distance. When pore water velocity decreased by an order of magnitude at 9 days following injection, apparent bacterial attachment rate coefficients did not decrease with velocity as expected …
Short-Term Temporal And Spatial Dynamics Of Bacterioplankton Near Barbados In The Caribbean Sea, Keun-Hyung Choi, Fred C. Dobbs, Robert K. Cowen
Short-Term Temporal And Spatial Dynamics Of Bacterioplankton Near Barbados In The Caribbean Sea, Keun-Hyung Choi, Fred C. Dobbs, Robert K. Cowen
OES Faculty Publications
To investigate temporal (ca 1 mo) and spatial dynamics of bacterioplankton in the Caribbean Sea, time-series measurements of chlorophyll a concentration, bacterial abundance, and thymidine incorporation rate were performed at 6 stations near Barbados, In addition, a series of incubation experiments was carried out with seawater samples collected from various depths and stations to determine bacterial growth rates and removal rates by bacterivory. Vertically integrated phytoplankton and bacterioplankton biomasses averaged 1290 and 1200 mg C m(-2), respectively, and heterotrophic bacterial production was 106 mg C m(-2), with in situ bacterial growth of 0.1 d(-1), Approximately halfway through the sampling period, …
Vertical Profiles Of Virus-Like Particles And Bacteria In The Water Column And Sediments Of Chesapeake Bay, Usa, Lisa A. Drake, Keun-Hyung Choi, A. G. Edward Haskell, Fred C. Dobbs
Vertical Profiles Of Virus-Like Particles And Bacteria In The Water Column And Sediments Of Chesapeake Bay, Usa, Lisa A. Drake, Keun-Hyung Choi, A. G. Edward Haskell, Fred C. Dobbs
OES Faculty Publications
Vertical profiles of virus-like particles (VLPs) and bacteria were determined by near-synoptic sampling through the water column and 15 to 25 cm into the sediment at 5 stations across the mouth of Chesapeake Bay, USA. VLPs were about 10 times more abundant in the pore water (grand mean = 3.6 x 10(8) VLPs ml(-1)) than in the water column (grand mean = 3.8 x 10(7) VLPs ml(-1)). Similarly, bacteria counts were about 3 times higher in the pore water (grand mean = 6.5 x 10(6) bacteria ml(-1)) than in the water column (grand mean = 2.4 x 10(6) bacteria ml(-1)). …
Thermophilic Bacterial Activity In A Deep-Sea Sediment From The Pacific Ocean, Fred C. Dobbs, Karen A. Selph
Thermophilic Bacterial Activity In A Deep-Sea Sediment From The Pacific Ocean, Fred C. Dobbs, Karen A. Selph
OES Faculty Publications
Thermophilic bacterial activity was detected in a deep-sea sediment sample from the South Pacific Ocean at 12 degrees S, 135 degrees W, an area of the seafloor distant from known hydrothermal venting. Incubation of sediments amended with C-14-glutamate indicated maximal respiration (evolution of (CO2)-C-14) and assimilation (incorporation of C-14 into acid-precipitated macromolecules) of substrate at 52 degrees C, relative to 4 and 22 degrees C. A parallel experiment at another site (2 degrees S, 140 degrees W) yielded no evidence of thermophily. Thermophilic bacteria may be deposited in deep-sea sediments following their long-distance dispersal from hydrothermal vents (e.g. the East …
A Computer-Simulated Restriction Fragment Length Polymorphism Analysis Of Bacterial Small-Subunit Rrna Genes: Efficacy Of Selected Tetrameric Restriction Enzymes For Studies Of Microbial Diversity In Nature, Craig L. Moyer, James M. Tiedje, Fred C. Dobbs, David M. Karl
A Computer-Simulated Restriction Fragment Length Polymorphism Analysis Of Bacterial Small-Subunit Rrna Genes: Efficacy Of Selected Tetrameric Restriction Enzymes For Studies Of Microbial Diversity In Nature, Craig L. Moyer, James M. Tiedje, Fred C. Dobbs, David M. Karl
OES Faculty Publications
An assessment of 10 tetrameric restriction enzymes (TREs) was conducted by using a computer-simulated restriction fragment length polymorphism (RFLP) analysis for over 100 proximally and distally related bacterial small-subunit (SSU) rRNA gene sequences. Screening SSU rDNA clone libraries with TREs has become an effective strategy because of logistic simplicity, commercial availability, and economy. However, the rationale for selecting the type and number of TREs has not been systematically evaluated. Our objective nas to identify the optimal combination of TREs for RnP screening of cloned SSU rRNA genes from undefined bacterial clone libraries. After computer-simulated TRE digestion, the resultant fragments were …
Cascading Disturbances In Florida Bay, Usa: Cyanobacteria Blooms, Sponge Mortality, And Implications For Juvenile Spiny Lobsters Panulirus Argus, Mark J. Butler Iv, John H. Hunt, William F. Herrnkind, Michael J. Childress, Rodney Bertelsen, William Sharp, Thomas Matthews, Jennifer M. Field, Harold G. Marshall
Cascading Disturbances In Florida Bay, Usa: Cyanobacteria Blooms, Sponge Mortality, And Implications For Juvenile Spiny Lobsters Panulirus Argus, Mark J. Butler Iv, John H. Hunt, William F. Herrnkind, Michael J. Childress, Rodney Bertelsen, William Sharp, Thomas Matthews, Jennifer M. Field, Harold G. Marshall
Biological Sciences Faculty Publications
Florida Bay, the shallow lagoon separating mainland Florida and the Florida Keys, USA, is experiencing an unprecedented series of ecological disturbances. In 1991, following reports of other ecosystem perturbations, we observed widespread and persistent blooms of cyanobacteria that coincided with the decimation of sponge communities over hundreds of square kilometers. Juvenile Caribbean spiny lobsters Panulirus argus, among other animals, rely on sponges for shelter; the impact of sponge loss on the abundance of lobsters and their use of shelter, in particular, has been dramatic. The loss of sponges on 27 experimental sites in hard bottom habitat in central Florida Bay …
Phylogenetic Diversity Of The Bacterial Community From A Microbial Mat At An Active, Hydrothermal Vent System, Loihi Seamount, Hawaii, Craig L. Moyer, Fred C. Dobbs, David M. Karl
Phylogenetic Diversity Of The Bacterial Community From A Microbial Mat At An Active, Hydrothermal Vent System, Loihi Seamount, Hawaii, Craig L. Moyer, Fred C. Dobbs, David M. Karl
OES Faculty Publications
The phylogenetic diversity of small-subunit rRNA genes associated,vith the domain Bacteria was examined (by using previously defined operational taxonomic units [C. L. Moyer, F. C. Dobbs, and D. M. Karl, Appl. Environ. Microbiol. 60:871-879, 1994]; those for Pele's Vents Bacteria are hereafter abbreviated PVB OTUs) with samples from a microbial mat at an active, deep-sea hydrothermal vent system. A cluster of phylogenetically related PVB OTUs (OTUs 2, 3, 6, and 8) was closely affiliated with Thiovulum sp. contained within the epsilon subclass of the class Proteobacteria and accounted for 60.5% of the small-subunit rRNA bacterial clone library from Pele's Vents. …
Estimation Of Diversity And Community Structure Through Restriction-Fragment-Length-Polymorphism Distribution Analysis Of Bacterial 16s Ribosomal-Rna Genes From A Microbial Mat At An Active, Hydrothermal Vent System, Loihi Seamount, Hawaii, Craig L. Moyer, Fred C. Dobbs, David M. Karl
Estimation Of Diversity And Community Structure Through Restriction-Fragment-Length-Polymorphism Distribution Analysis Of Bacterial 16s Ribosomal-Rna Genes From A Microbial Mat At An Active, Hydrothermal Vent System, Loihi Seamount, Hawaii, Craig L. Moyer, Fred C. Dobbs, David M. Karl
OES Faculty Publications
PCR was used to amplify (eu)bacterial small-subunit (16S) rRNA genes from total-community genomic DNA. The source of total-community genomic DNA used for this culture-independent analysis was the microbial mats from a deep-sea, hydrothermal vent system, Pele's Vents, located at Loihi Seamount, Hawaii. Oligonucleotides complementary to conserved regions in the 16S rRNA-encoding DNA (rDNA) of bacteria were used to direct the synthesis of PCR products, which were then subcloned by blunt-end ligation into phagemid vector pBluescript II. Restriction fragment length polymorphism patterns, created by using tandem tetrameric restriction endonucleases, revealed the presence of 12 groups of 16S rRNA genes representing discrete …
A Comparison Of No And N20 Production By The Autophic Nitrifier Nitrosomonas Europaea And The Heterotrophic Nitrifier Alcaligenes Faecalis, Iris C. Anderson, Mark Poth, Julie Homstead, David J. Burdige
A Comparison Of No And N20 Production By The Autophic Nitrifier Nitrosomonas Europaea And The Heterotrophic Nitrifier Alcaligenes Faecalis, Iris C. Anderson, Mark Poth, Julie Homstead, David J. Burdige
OES Faculty Publications
Soil microorganisms are important sources of the nitrogen trace gases NO and N2O for the atmosphere. Present evidence suggests that autotrophic nitrifiers such as Nitrosomonas europaea are the primary producers of NO and N2O in aerobic soils, whereas denitrifiers such as Pseudomonas spp. or Alcaligenes spp. are responsible for most of the NO and N2O emissions from anaerobic soils. It has been shown that Alcaligenes faecalis, a bacterium common in both soil and water, is capable of concomitant heterotrophic nitrification and denitrification. This study was undertaken to determine whether heterotrophic nitrification might be …
Preservation Of Atp In Hypersaline Environments, Bruce J. Tuovila, Fred C. Dobbs, Paul A. Larock, B. Z. Siegel
Preservation Of Atp In Hypersaline Environments, Bruce J. Tuovila, Fred C. Dobbs, Paul A. Larock, B. Z. Siegel
OES Faculty Publications
High concentrations of particulate ATP were found in the anoxic brines of the Orca Basin and East Flower Garden, Gulf of Mexico. Other measurements indicative of growth and respiration suggested that the microbial community in the brines was inactive, but somehow the ATP associated with the cells persisted. Conceivably, when cells growing just above the interface sank into the brine, the increased osmotic stress could elicit an osmoregulatory response resulting in increased ATP. It was also possible that hydrolytic enzymes were inactivated, resulting in the preservation of ATP. Experiments in which a culture of marine bacteria was suspended in menstrua …