Arnosti Carol

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Arnosti

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Carol

ORCID

0000-0002-6074-5341

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Structural characterization and bacterial degradation of marine carbohydrates

(Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1993-05) Arnosti, Carol

The goal of this thesis was to develop and apply an integrated chemical and microbial approach to study the effects of chemical structure on the rates and patterns of carbohydrate degradation by anaerobic marine bacteria. Polysaccharides produced by five species of marine plankton, Dunaliella tertiolecta, Emiliania huxleyi, Stephanopixis palmeri, a Phaeocystis sp., and Synechococcus WH7335, were surveyed using one- and two-dimensional nuclear magnetic resonance spectroscopy (NMR). Two carbohydrates from Synechococcus WH7335 were characterized in detail. Synechococcus produced an α(1,4) glucose polysaccharide with α(1,6) branches, which probably functions as an energy reserve. The nominal molecular weight of the polysaccharide was ~5000 daltons. Large quantities of a glycerolpolysaccharide, which was tentatively identified as a teichoic acid similar in structure to teichoic acids found in cell walls of gram-positive bacteria, were also produced by Synechococcus WH7335. This is the first report of teichoic acids in cyanobacteria. Enrichment of bacteria from anoxic marine sediments on specific carbohydrates yielded reproducible model systems with which to study the degradation of chemically well-defined substrates. Headspace gases (C02, H2, CH4, H2S) were monitored by gas chromatography, and carbohydrate substrates and intermediates were separated and quantified via gel-permeation chromatography and high-pressure liquid chromatography. The transfer of carbon from substrates through to end products was followed quantitatively. Nuclear magnetic resonance spectroscopy was used to check for selective structural alterations (such as preferential cleavage of specific linkage types or positions) of the substrates. A series of enrichment experiments showed that mixed cultures of marine bacteria distinguish even between small, very closely-related substrates which do not require extracellular hydrolysis prior to uptake. A galactose-β(1,3)-arabinose dimer was degraded at half the rate of seven other similar disaccharides and three larger oligosaccharides. A further series of degradation experiments with polysaccharides (pullulan, laminarin) showed that they are degraded by bacteria at virtually the same rate as structurally related substrates in the molecular weight range of 300-600 daltons. Degradation of the branched glucan and the teichoic acid-type polysaccharide from Synechococcus WH7335 was also very rapid. The time-course of bacterial hydrolysis of pullulan was examined with gel permeation chromatography and NMR to provide the first molecular-level evidence in marine systems of the bacterial extracellular transformation of high molecular weight organic matter to lower molecular weight organic matter. NMR spectra provided evidence that the pullulan was hydrolyzed by pullulanase, an endo-acting extracellular enzyme which preferentially hydrolyzes α(1,6) linkages. This is the first experimental evidence of pullulanase activity among marine mesophilic bacteria. The culture results suggest that enzymatic hydrolysis of macromolecular carbohydrates to transportable pieces is not the slow step in bacterial degradation of at least some types of polysaccharides. The results from the oligosaccharide experiments suggest that certain heteropolysaccharides may not be degraded as quickly. Chemical structure can be more important than molecular weight in determining degradation rates of carbohydrates. Varying rates of organic polymer degradation in anoxic sediments may be largely determined by the sensitivity of bacterial enzymatic and transport systems to structural features.
Microbial enzyme activities: peptidase activities of gravity-filtered seawater samples from the RV\Polarstern cruise ARKXXVII/3 in the Central Arctic Ocean and Laptev Sea, Aug-Sept. 2012

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2020-04-27) Arnosti, Carol

This dataset includes microbial peptidase hydrolysis rates measured on particles collected from gravity filtered seawater. Links to archived CTD data are also provided. Five substrates linked to a 7-amido-4-methyl coumarin (MCA) fluorophore, one amino acid – leucine – and four oligopeptides – the chymotrypsin substrates alanine-alanine-phenylalanine (AAF) and alanine-alanine-proline-phenylalanine (AAPF), and the trypsin substrates glutamine-alanine-arginine (QAR) and glutamic acid-gylcine-arginine (EGR) – were used to measure exo- and endo-acting peptidase activities, respectively. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/742967
Microbial enzyme activities: polysaccharide hydrolase activities in bulk seawater samples from the RV\Polarstern cruise ARKXXVII/3 in the Central Arctic Ocean and Laptev Sea, Aug-Sept. 2012

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2020-04-27) Arnosti, Carol

This dataset includes polysaccharide hydrolysis rates measured in bulk (not filter-fractionated) seawater. Links to archived CTD data are also provided. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/742235
Measurements of nutrients, bacterial cell concentration and bacterial production from RV/Endeavor EN556, June 2015 (Patterns of activities project)

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2020-05-13) Arnosti, Carol

Nutrients, bacterial cell counts, and bacterial protein production as measured by 3H-leucine incorporation from the 'bulk water experiments'. Water was collected on EN556. See Niskin Bottle and Cast List EN556 to link specific casts and bottles to each experiment: https://www.bco-dmo.org/dataset/717427. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/717577
Hydrolysis rates from bulk water sample incubations, fluorometer results from RV/Endeavor EN556, 2015 (Patterns of activities project)

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2020-05-13) Arnosti, Carol

This dataset includes polysaccharide hydrolysis rates to measure microbial enzyme activities and bacterial productivity. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/719712
Hydrolysis rates from incubations on particles obtained by gravity filtration of water collected on RV/Endeavor EN556 (Patterns of activities project)

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2020-05-13) Arnosti, Carol

This dataset includes polysaccharide hydrolysis rates to measure microbial enzyme activities and bacterial productivity at multiple time points. The water was from gravity filtration samples. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/720307
Microbial enzyme activities: peptidase activities in bulk seawater samples from the RV\Polarstern cruise ARKXXVII/3 in the Central Arctic Ocean and Laptev Sea, Aug-Sept. 2012

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2020-04-27) Arnosti, Carol

This dataset includes peptidase activities measured in bulk (not filter-fractionated) seawater. Links to archived CTD data are also provided. Five substrates linked to a 7-amido-4-methyl coumarin (MCA) fluorophore, one amino acid – leucine – and four oligopeptides – the chymotrypsin substrates alanine-alanine-phenylalanine (AAF) and alanine-alanine-proline-phenylalanine (AAPF), and the trypsin substrates glutamine-alanine-arginine (QAR) and glutamic acid-gylcine-arginine (EGR) – were used to measure exo- and endo-acting peptidase activities, respectively. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/742780
Large substrate hydrolysis of bulk water samples taken aboard the R/V Endeavor EN638, May 2019 in the Northern Atlantic.

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2020-09-24) Arnosti, Carol

Large substrate hydrolysis of bulk water samples taken aboard the R/V Endeavor EN638, May 2019 in the Northern Atlantic. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/821801
Bulk water cell abundance of samples taken aboard the R/V Endeavor EN638, May 2019 in the Northern Atlantic

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2020-09-24) Arnosti, Carol

Bulk water cell abundance of samples taken aboard the R/V Endeavor EN638, May 2019 in the Northern Atlantic For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/820961
Measurements of peptidase and glucosidase activities in large volume mesocosm incubations on RV/Endeavor EN584, July 2016 (Patterns of activities project)

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2022-12-07) Arnosti, Carol

Measurements of peptidase and glucosidase activities in large volume mesocosm incubations on RV/Endeavor EN584, July 2016 (Patterns of activities project) For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/717532
Small substrate hydrolysis of large volume (LV) samples aboard the R/V Endeavor EN638, May 2019 in the Northern Atlantic.

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2022-12-07) Arnosti, Carol

Small substrate hydrolysis of large volume (LV) samples aboard the R/V Endeavor EN638, May 2019 in the Northern Atlantic. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/821694
Hydrolysis rates from bulk samples, plate reader results from RV/Endeavor EN556, 2015 (Patterns of activities project)

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2020-05-13) Arnosti, Carol

This dataset includes polysaccharide hydrolysis rates to measure microbial enzyme activities and bacterial productivity, from bulk samples, plate reader results from RV/Endeavor EN556, 2015. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/719487
Microbial enzymatic activities from seawater and from particle-associated seawater communities from Greenland, August 2015 (Patterns of activities project)

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2020-05-13) Arnosti, Carol

Bacterial activity as measured by hydrolysis rates from unfiltered seawater and particle-associated communities collected near shore in northeastern Greenland in August 2015. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/717660
Microbial enzyme activities: glucosidase and peptidase activities of bulk seawater samples from the RV\Sonne cruise SO248 in the South and North Pacific, along 180 W, May, 2016

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2020-04-27) Arnosti, Carol

This dataset includes MCAMUF (glucosidase and peptidase) hydrolysis rates to measure microbial enzyme activities in bulk (not filter-fractionated) seawater. Samples were collected on RV/Sonne cruise SO248 in May 2016. Links to archived CTD data are also provided. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/743224
Microbial enzyme activities: peptidase activities of sediment samples from the RV\Polarstern cruise ARKXXVII/3 in the Central Arctic Ocean and Laptev Sea, Aug-Sept. 2012

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2020-04-27) Arnosti, Carol

This dataset includes peptidase hydrolysis rates from sediments to measure microbial enzyme activities. Links to archived CTD data are also provided. Five substrates linked to a 7-amido-4-methyl coumarin (MCA) fluorophore, one amino acid – leucine – and four oligopeptides – the chymotrypsin substrates alanine-alanine-phenylalanine (AAF) and alanine-alanine-proline-phenylalanine (AAPF), and the trypsin substrates glutamine-alanine-arginine (QAR) and glutamic acid-gylcine-arginine (EGR) – were used to measure exo- and endo-acting peptidase activities, respectively. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/743018
Microbial enzyme activities: polysaccharide hydrolase activities in bulk seawater samples from the RV\Sonne cruise SO248 in the South and North Pacific, along 180 W, May, 2016

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2020-04-27) Arnosti, Carol

This dataset includes polysaccharide hydrolysis rates measured in bulk (not filter-fractionated) seawater. Samples were collected on RV/Sonne cruise SO248 in May 2016. Links to archived CTD data are also provided. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/743054
Microbial enzyme activities: polysaccharide hydrolase activities of gravity filtered seawater samples from the RV\Polarstern cruise ARKXXVII/3 in the Central Arctic Ocean and Laptev Sea, Aug-Sept. 2012

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2020-04-27) Arnosti, Carol

This dataset includes polysaccharide hydrolysis rates measured in samples from gravity filtered seawater. Links to archived CTD data are also provided. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/742919
The role of dispersants in oil spill remediation : fundamental concepts, rationale for use, fate, and transport issues

(The Oceanography Society, 2016-09) John, Vijay ; Arnosti, Carol ; Field, Jennifer ; Kujawinski, Elizabeth B. ; McCormick, Alon

Offering a scientific perspective, this paper provides a rationale for the use of dispersants in oil spill remediation by discussing their formulations and modes of action and connecting their physics and chemistry to a their environmental fates and impacts. With the first use of dispersants at the source of the oil release during the Deepwater Horizon incident, there is a new great need for understanding the efficiency and the environmental impacts of their use. The paper concludes with some cautionary recommendations on dispersant research.
Particulate organic carbon deconstructed: molecular and chemical composition of particulate organic carbon in the ocean

(Frontiers Media, 2020-06-26) Kharbush, Jenan J. ; Close, Hilary G. ; Van Mooy, Benjamin A. S. ; Arnosti, Carol ; Smittenberg, Rienk H. ; Le Moigne, Frederic A. C. ; Mollenhauer, Gesine ; Scholz-Böttcher, Barbara ; Obreht, Igor ; Koch, Boris P. ; Becker, Kevin W. ; Iversen, Morten H. ; Mohr, Wiebke

The dynamics of the particulate organic carbon (POC) pool in the ocean are central to the marine carbon cycle. POC is the link between surface primary production, the deep ocean, and sediments. The rate at which POC is degraded in the dark ocean can impact atmospheric CO2 concentration. Therefore, a central focus of marine organic geochemistry studies is to improve our understanding of POC distribution, composition, and cycling. The last few decades have seen improvements in analytical techniques that have greatly expanded what we can measure, both in terms of organic compound structural diversity and isotopic composition, and complementary molecular omics studies. Here we provide a brief overview of the autochthonous, allochthonous, and anthropogenic components comprising POC in the ocean. In addition, we highlight key needs for future research that will enable us to more effectively connect diverse data sources and link the identity and structural diversity of POC to its sources and transformation processes.
Gulf Stream ring water intrusion on the Mid-Atlantic Bight continental shelf break affects microbially driven carbon cycling

(Frontiers Media, 2019-07-11) Hoarfrost, Adrienne ; Balmonte, John Paul ; Ghobrial, Sherif ; Ziervogel, Kai ; Bane, John M. ; Gawarkiewicz, Glen G. ; Arnosti, Carol

Warm core, anticyclonic rings that spin off from the Gulf Stream circulate through the region directly offshore of the Mid-Atlantic Bight. If a warm core ring reaches the continental shelf break, its warm, highly saline water may subduct under cooler, fresher continental shelf surface water, resulting in subsurface waters at the shelf break and over the upper continental slope with high temperatures and salinities and distinct physical and chemical properties characteristic of Gulf Stream water. Such intruding water may also have microbial communities with distinct functional capacities, which may in turn affect the rate and nature of carbon cycling in this coastal/shelf environment. However, the functional capabilities of microbial communities within ring intrusion waters relative to surrounding continental shelf waters are largely unexplored. We investigated microbial community capacity to initiate organic matter remineralization by measuring hydrolysis of a suite of polysaccharide, peptide, and glucose substrates along a transect oriented across the Mid-Atlantic Bight shelf, shelf break, and upper slope. At the outermost sampling site, warm and salty water derived from a Gulf Stream warm core ring was present in the lower portion of the water column. This water exhibited hydrolytic capacities distinct from other sampling sites, and exhibited lower heterotrophic bacterial productivity overall. Warm core rings adjacent to the Mid-Atlantic Bight shelf have increased in frequency and duration in recent years. As the influence of warm core rings on the continental shelf and slope increases in the future, the rate and nature of organic matter remineralization on the continental shelf may also shift.

Arnosti Carol

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