Physical Sciences and Mathematics | Open Access Articles

Reply To Comment: Controls On Turnover Of Marine Dissolved Organic Matter-Testing The Null Hypothesis Of Purely Concentration-Driven Uptake, Yuan Shen, Ronald Benner

Faculty Publications

Our recent bioassay experiments indicate that molecular properties are a primary control on the microbial utilization of dissolved organic matter in the ocean. This finding is questioned by Lennartz and Dittmar who modeled our experiments and concluded that our observations could be largely explained by concentration-driven uptake independent from molecular properties. We suggest the authors' models are deficient for establishing the relative roles of molecular properties and concentration-driven uptake. Our conclusion is consistent with earlier and recent experimental results and biogeochemical observations, supporting a unified theory with molecular properties as a more prominent control than concentration-driven uptake on marine organic …

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Broken-Hearted” Carbon Bowl Via Electron Shuttle Reaction: Energetics And Electron Coupling, Gabrielle A. Leith, Allison M. Rice, Brandon J. Yarbrough, Preecha Kittikhunnatham, Abijai Mathur, Nicholas A. Morris, Megan J. Francis, Anna A. Berseneva, Poonam Dhull, Richard D. Adams, M. Victoria Bobo, Aaron A. Vannucci, Mark D. Smith, Sophya Garashchuk, Natalia B. Shustova

Faculty Publications

Unprecedented one-step CC bond cleavage leading to opening of the buckybowl (π-bowl), that could provide access to carbon-rich structures with previously inaccessible topologies, is reported; highlighting the possibility to implement drastically different synthetic routes to π-bowls in contrast to conventional ones applied for polycyclic aromatic hydrocarbons. Through theoretical modeling, we evaluated the mechanistic pathways feasible for π-bowl planarization and factors that could affect such a transformation including strain and released energies. Through employment of Marcus theory, optical spectroscopy, and crystallographic analysis, we estimated the possibility of charge transfer and electron coupling between “open” corannulene and a strong electron acceptor such …

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Particulate And Dissolved Organic Matter In Stormwater Runoff Influences Oxygen Demand In Urbanized Headwater Catchments, Kelly M. Mccabe, Erik M. Smith, Susan Q. Lang, Claudia Benitez-Nelson

Faculty Publications

Increasing inputs of organic matter (OM) are driving declining dissolved oxygen (DO) concentrations in coastal ecosystems worldwide. The quantity, source, and composition of OM transported to coastal ecosystems via stormwater runoff have been altered by land use changes associated with urbanization and subsequent hydrologic flows that accompany urban stormwater management. To elucidate the role of stormwater in the decline of coastal DO, rain event sampling of biochemical oxygen demand (BOD) in samples collected from the outfall of stormwater ponds and wetlands, as well as samples of largely untreated runoff carried by stormwater ditches, was conducted across a range of urban …

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Green Edge Ice Camp Campaigns: Understanding The Processes Controlling The Under-Ice Arctic Phytoplankton Spring Bloom, Philippe Massicotte, Rémi Amiraux, Marie-Pier Amyot, Philippe Archambault, Mathieu Ardyna, Laurent Arnaud, Lise Artigue, Cyril Aubry, Pierre Ayotte, Guislain Bécu, Simon Bélanger, Ronald Benner, Henry C. Bittig, Annick Bricaud, Éric Brossier, Flavienne Bruyant, Et. Al.

Faculty Publications

The Green Edge initiative was developed to investigate the processes controlling the primary productivity and fate of organic matter produced during the Arctic phytoplankton spring bloom (PSB) and to determine its role in the ecosystem. Two field campaigns were conducted in 2015 and 2016 at an ice camp located on landfast sea ice southeast of Qikiqtarjuaq Island in Baffin Bay (67.4797∘ N, 63.7895∘ W). During both expeditions, a large suite of physical, chemical and biological variables was measured beneath a consolidated sea-ice cover from the surface to the bottom (at 360 m depth) to better understand the factors driving the …

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Endolithic Microbial Carbon Cycling In East Antarctica, Natalie Tyler

Theses and Dissertations

Microbes adapt to inhospitable conditions by colonizing niches that protect them from severe environmental conditions, making them model organisms in the search for life on other planets. Endoliths are globally ubiquitous microbes that colonize structural cavities within rocks, which protect them from environmental stressors while maintaining access to nutrition and light sources. Despite harsh katabatic winds, extreme temperature fluctuations, harmful UV radiation and exposure to desiccation, endolithic communities have been observed in Antarctica. Previous studies have found viable and abundant microbial biomass through microscopy and the addition of isotopic labels. However, due to the slow metabolic activity of these microbes, …

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Unveiling The Enigma Of Refractory Carbon In The Ocean, Nianzhi Jiao, Ruanhong Cai, Qiang Zheng, Kai Tang, Jihua Liu, Fangkue Jiao, Douglas Wallace, Feng Chen, Chao Li, Rudolf Amann, Ronald Benner, Farooq Azam

Faculty Publications

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Marine Sequestration Of Carbon In Bacterial Metabolites, Oliver J. Lechtenfeld, Norbert Hertkorn, Yuan Shen, Matthias Witt, Ronald Benner

Faculty Publications

Linking microbial metabolomics and carbon sequestration in the ocean via refractory organic molecules has been hampered by the chemical complexity of dissolved organic matter (DOM). Here, using bioassay experiments and ultra-high resolution metabolic profiling, we demonstrate that marine bacteria rapidly utilize simple organic molecules and produce exometabolites of remarkable molecular and structural diversity. Bacterial DOM is similar in chemical composition and structural complexity to naturally occurring DOM in sea water. An appreciable fraction of bacterial DOM has molecular and structural properties that are consistent with those of refractory molecules in the ocean, indicating a dominant role for bacteria in shaping …

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Reply To Comment: Controls On Turnover Of Marine Dissolved Organic Matter-Testing The Null Hypothesis Of Purely Concentration-Driven Uptake, Yuan Shen, Ronald Benner

Faculty Publications

Faculty Publications

Particulate And Dissolved Organic Matter In Stormwater Runoff Influences Oxygen Demand In Urbanized Headwater Catchments, Kelly M. Mccabe, Erik M. Smith, Susan Q. Lang, Claudia Benitez-Nelson

Faculty Publications

Faculty Publications

Endolithic Microbial Carbon Cycling In East Antarctica, Natalie Tyler

Theses and Dissertations

Unveiling The Enigma Of Refractory Carbon In The Ocean, Nianzhi Jiao, Ruanhong Cai, Qiang Zheng, Kai Tang, Jihua Liu, Fangkue Jiao, Douglas Wallace, Feng Chen, Chao Li, Rudolf Amann, Ronald Benner, Farooq Azam

Faculty Publications

Marine Sequestration Of Carbon In Bacterial Metabolites, Oliver J. Lechtenfeld, Norbert Hertkorn, Yuan Shen, Matthias Witt, Ronald Benner

Faculty Publications