Biogeosciences
www.biogeosciences.net
1726-4170
1726-4189
7
1
2010
10.5194/bg-7-109-2010
http://www.biogeosciences.net/7/109/2010/
http://www.biogeosciences.net/7/109/2010/bg-7-109-2010.html
http://www.biogeosciences.net/7/109/2010/bg-7-109-2010.pdf
109
119
2010-01-11
The role of polysaccharides and diatom exudates in the redox cycling of Fe and the photoproduction of hydrogen peroxide in coastal seawaters
S. Steigenberger
ss2p07@noc.soton.ac.uk
P. J. Statham
C. Völker
U. Passow
Alfred Wegener Institut für Polar- und Meeresforschung, Am Handelshafen 12, 27570 Bremerhaven, Germany
National Oceanography Centre, Southampton, University of Southampton Waterfront Campus, European Way, Southampton SO14 3ZH, UK
The effect of artificial acidic polysaccharides (PS) and exudates of
<i>Phaeodactylum tricornutum</i> on the half-life of Fe(II) in seawater was investigated in laboratory
experiments. Strong photochemical hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>)
production of 5.2 to 10.9 nM (mg C)<sup>−1</sup> h<sup>−1</sup> was found in the
presence of PS and diatom exudates. Furthermore when illuminated with UV
light the presence of algal exudates had a net stabilising effect on ferrous
iron in seawater (initial value 100 nmol L<sup>−1</sup>) above that expected from
oxidation kinetics. In the dark the PS gum xanthan showed no stabilising
effect on Fe(II). The photochemical formation of superoxide (O<sub>2</sub><sup>−</sup>)
in the presence of diatom exudates and its reducing effect on Fe(III)
appears to result in greater than expected concentrations of Fe(II). A model
of the photochemical redox cycle of iron incorporating these processes
supported the observed data well. Diatom exudates seem to have the potential
to play an important role for the photochemistry of iron in coastal waters.
Benner, R., Pakulski, J. D., MacCarthy, M., Hedges, J. I., and Hatcher, P. G.: Bulk chemical characteristics of dissolved organic matter in the ocean, Science, 255, 1561–1564, 1992.
Boyd, P. W., Jickells, T., Law, C. S., et al.: Mesoscale iron enrichment experiments 1993–2005: synthesis and future directions, Science, 315, 612–617, 2007.
Boye, M.: Organic complexation of iron in the Southern Ocean, Deep-Sea Res. I, 48(6), 1477–1497, 2001.
Butler, A.: Marine Siderophores and Microbial Iron Mobilization, BioMetals, 18(4), 369–374, 2005.
Cooper, W. J., Zika, R. G., Petasne, R. G., and Plane, J. M. C.: Photochemical formation of H<sub>2</sub>O<sub>2</sub> in natural waters exposed to sunlight, Environ. Sci. Technol., 22, 1156–1160, 1988.
Croot, P. L. and Johansson, M.: Determination of iron speciation by cathodic stripping voltammetry in seawater using the competing ligand 2-(2-Thiazolylazo)-p-cresol (TAC), Electroanalysis, 12(8), 565–576, 2000.
Croot, P. L. and Laan, P.: Continuous shipboard determination of Fe(II) in polar waters using flow injection analysis with chemiluminescence detection, Anal. Chim. Acta, 466, 261–273, 2002.
Croot, P. L., Laan, P., Nishioka, J., et al.: Spatial and temporal distribution of Fe(II) and H<sub>2</sub>O<sub>2</sub> during EisenEx, an open ocean mescoscale iron enrichment, Mar. Chem., 95, 65–88, 2005.
Donat, J. R. and Bruland, K. W.: Direct determination of dissolved Cobalt and Nickel in seawater by differential pulse cathodic stripping voltammetry preceded by adsorptive collection of cyclohexane-1,2-dione dioxime complexes, Anal. Chem., 60, 240–244, 1988.
Falkowski, P. G., Barber, R. T., and Smetacek, V.: Biogeochemical controls and feedbacks on ocean primary production, Science, 281(5374), 200–206, 1998.
Ford, C. W. and Percival, E.: The carbohydrates of Phaeodactylum tricornutum, J. Chem. Soc., 7035–7041, 1965.
Fujii, M., Rose, A. L., Waite, T. D., and Omura, T.: Superoxide-mediated dissolution of amorphous ferric oxyhydroxide in seawater, Environ. Sci. Technol., 40(3), 880–887, 2006.
Garg, S., Rose, A. L., and Waite, T. D.: Superoxide-mediated reduction of organically complexed iron(III): Impact of pH and competing cations (Ca2+), Geochim. Cosmochim. Ac., 71, 5620–5634, 2007a.
Garg, S., Rose, A. L., and Waite, T. D.: Superoxide mediated reduction of organically complexed Iron(III): Comparison of non-dissociative and dissociative reduction pathways. Environ. Sci. Technol., 41(9), 3205–3212, 2007b.
Gehrmann, W. H.: Ultrviolet Irradiances of Various Lamps Used in Animal Husbandry, Zoo Biol., 6, 117–127, 1987.
Geider, R. J and Roche, J. L.: The role of iron in phytoplankton photosynthesis and the potential for iron-limitation of primary productivity in the sea, Photosynth. Res., 39, 275–301, 1994.
Gerringa, L. J. A., Rijkenberg, M. J. A., Timmermans, K. R., and Buma, A. G. J.: The influence of solar ultraviolet radiation on the photochemical production of H<sub>2</sub>O<sub>2</sub> in the equatorial Atlantic Ocean, J. Sea Res., 51, 3–10, 2004.
Gonzalez-Davila, M., Santana-Casiano, J. M., and Millero, F. J.: Oxidation of iron (II) nanomolar with H<sub>2</sub>O<sub>2</sub> in seawater. Geochim. Cosmochim. Ac., 69(1), 83–93, 2005.
Gonzalez-Davila, M., Santana-Casiano, J. M., and Millero, F. J.: Competition between O<sub>2</sub> and H<sub>2</sub>O<sub>2</sub> in the oxidation of Fe(II) in natural waters, J. Solution Chem., 35(1), 95–111, 2006.
Hellebust, J. A.: Excretion of some organic compounds by marine phytoplankton, Limnol. Oceanogr., 10, 192–206, 1965.
Hellebust, J. A.: Extracellular products, edited by: Stewart, W. D. P., Algal physiology and biochemistry, Blackwell, 838–863, 1974.
Hutchins, D. A. and Bruland, K. W.: Iron-limited diatom growth and Si:N uptake ratios in a coastal upwelling regime, Nature, 393, 561–564, 1998.
Johnson, K. S., Gordon, R. M., and Coale, K. H.: What controls dissolved iron concentrations in the world ocean?, Mar. Chem., 57(3/4), 137–161, 1997.
Kari, F. G., Hilger, S., and Canonica, S.: Determination of the Reaction Quantum Yield for the Photochemical Degradation of Fe(III)-EDTA: Implications for the Environmental Fate of EDTA in Surface Waters, Environ. Sci. Technol., 29, 1008–1017, 1995.
King, D. W., Lounsbury, H. A., and Millero, F. J.: Rates and mechanism of Fe(II) oxidation at nanomolar total iron concentrations, Environ. Sci. Technol., 29, 818–824, 1995.
Kuma, K., Nakabayashi, S., and Matsunaga, K.: Photoreduction of Fe(III) by hydrocarboxylic acids in seawater, Water Res., 29(6), 1559–1569, 1995.
Kuma, K., Nakabayashi, S., Suzuki, Y., Kudo, I., and Matsunaga, K.: Photoreduction of Fe(III) by dissolved organic substances and existence of Fe(II) in seawater during spring blooms, Mar. Chem., 37, 15–27, 1992.
Laglera, L. M. and Van den Berg, C. M. G.: Wavelength dependence of the photochemical reduction of iron in arctic seawater, Environ. Sci. Technol., 41, 2296–2302, 2007.
Macrellis, H. M., Trick, C. G., Rue, L. E., Smith, G., and Bruland, K. W.: Collection and detection of natural iron-binding ligands from seawater, Mar. Chem., 76, 175–187, 2001.
Meunier, L., Laubscher, H., Hug, S. J., and Sulzberger, B.: Effects of size and origin of natural dissolved organic matter compounds on the redox cycling of iron in sunlit surface waters, Aquat. Sci., 67(3), 292–307, 2005.
Miles, C. J. and Brezonik, P. L.: Oxygen consumption in humic-colored waters by a photochemical ferrous-ferric catalytic cycle, Environ. Sci. Technol., 15(9), 1089–1095, 1981.
Miller, W. L., King, D. W., Lin, J., and Kester, D. R.: Photochemical redox cycling of iron in coastal seawater, Mar. Chem., 50, 63–77, 1995.
Millero, F. J. and Sotolongo, S.: The oxidation of Fe(II) with H<sub>2</sub>0<sub>2</sub> in seawater, Geochim. Cosmochim. Ac., 53, 1867–1873, 1989.
Millero, F. J., Sotolongo, S., and Izaguirre, M.: The oxidation kinetics of Fe(II) in seawater, Geochim. Cosmochim. Ac., 51, 793–801, 1987.
Moffett, J. W. and Zafiriou, O. C.: An investigation of hydrogen peroxide in surface waters of Vineyard Sound with H$_2^18$O<sub>2</sub> and $^18$O<sub>2</sub>, Limnol. Oceanogr., 35, 1221–1229, 1990.
Morel, F. M. M. and Price, N. M.: The biogeochemical cycles of trace metals in the oceans, Science, 300, 944–947, 2003.
Myklestad, S. M., Skanoy, E., and Hestmann, S.: A sensitive and rapid method for analysis of dissolved mono- and polysaccharides in seawater, Mar. Chem., 56(3/4), 279–286, 1997.
Nelder, J. A. and Mead, R.: A simplex method for function minimization. Comput. J., 7, 308–313, 1965.
Obernosterer, I. B.: Photochemical transformations of dissolved organic matter and its subsequent utilization by marine bacterioplankton, PhD thesis, 133~pp., 2000.
Ozturk, M., Croot, P. L., Bertilsson, S., et al.: Iron enrichment and photoreduction of iron under UVand PAR in the presence of hydroxycarboxylic acid: implications for phytoplankton growth in the Southern Ocean, Deep-Sea Res. II, 51, 2841–2856, 2004.
Passow, U.: Transparent exopolymer particles (TEP) in aquatic environments, Prog. Oceanogr., 55, 287–333, 2002.
Passow, U., Dunne, J., Murray, J. W., Balistrieri, L., and Alldredge, A. L.: Organic carbon to $^234$Th ratios of marine organic matter, Mar. Chem., 100, 323–336, 2006.
Petasne, R. G. and Zika, R. G.: Hydrogen peroxide lifetimes in south Florida coastal and offshore waters, Mar. Chem., 56, 215–225, 1997.
Price, D., Mantoura, R. F. C., and Worsfold, P. J.: Shipboard determination of hydrogen peroxide in the western Mediterranean sea using flow injection with chemiluminescence detection, Anal. Chim. Acta, 377, 145–155, 1998.
Rice, P. J., Lockhart, B. E., Barker, L. A., et al.: Pharmacokinetics of fungal (1–3)-β-Image-glucans following intravenous administration in rats, Int. Immunopharmacol., 4(9), 1209–1215, 2004.
Rijkenberg, M. J. A., Fischer, A. C., Kroon, J. J., et al.: The influence of UV irradiation on photoreduction of iron in th Southern Ocean, Mar. Chem., 93, 119–129, 2005.
Rijkenberg, M. J. A., Gerringa, L. J. A., Carolus, V. E., Velzeboer, I., and de Baar, H. J. W.: Enhancement and inhibition of iron photoreduction by individual ligands in open ocean seawater, Geochim. Cosmochim. Ac., 70(11), 2790–2805, 2006.
Rijkenberg, M. J. A., Gerringa, L. J. A., Timmermans, K. R., et al.: Enhancement of the reactive iron pool by marine diatoms, Mar. Chem., 109, 29–44, 2008.
Rose, A. L. and Waite, T. D.: Kinetic model for Fe(II) oxidation in seawater in the absence and presence of natural organic matter, Environ. Sci. Technol., 36, 433–444, 2002.
Rose, A. L. and Waite, T. D.: Effect of Dissolved Natural Organic Matter on the Kinetics of Ferrous Iron Oxygenation in Seawater, Environ. Sci. Technol., 37, 4877–4886, 2003a.
Rose, A. L. and Waite, T. D.: Kinetics of iron complexation by dissolved natural organic matter in coastal waters Mar. Chem., 84(1/2), 85–103, 2003b.
Rose, A. L. and Waite, T. D.: Predicting iron speciation in coastal waters from the kinetics of sunlight-mediated iron redox cycling, Aquat. Sci.-Res. Across Boundaries, 65(4), 375–383, 2003c.
Rose, A. L. and Waite, T. D.: Reduction of organically complexed ferric iron by superoxide in a simulated natural water, Environ. Sci. Technol., 39(8), 2645–2650, 2005.
Rose, A. L. and Waite, T. D.: Role of superoxide in the photochemical reduction of iron in seawater, Geochim. Cosmochim. Ac., 70(15), 3869–3882, 2006.
Rue, E. L. and Bruland, K. W.: Complexation of iron(III) by natural organic ligands in the central North Pacific as determined by a new competitive ligand equilibrium/adsorptive cathodic stripping voltammetric method, Mar. Chem., 50, 117–138, 1995.
Rush, J. D. and Bielski, B. H. J.: Pulse radiolysis studies of the reactions of HO<sub>2</sub>/O$_2^-$ with ferric ions and its implications on the occurence of the Haber-Weiss reaction, J. Phys. Chem., 89, 5062–5066, 1985.
Santana-Casiano, J., Vila, M. G.-D., Rodriìguez, M., and Millero, F.: The effect of organic compounds in the oxidation kinetics of Fe(II), Mar. Chem., 70(1–3), 211–222, 2000.
Santana-Casiano, J. M., Gonzalez-Davila, M., and Millero, F. J.: The oxidation of Fe(II) in NaCl-HCO<sub>3</sub>- and seawater solutions in the presence of phthalate and salicylate ions: a kinetic model, Mar. Chem., 85(1/2), 27–40, 2004.
Scully, N. M., McQueen, D. J., Lean, D. R. S., and Cooper, W. J.: Hydrogen peroxide formation: The interaction of ultraviolet radiation and dissolved organic carbon in lake waters along a 43–75 degrees N gradient, Limnol. Oceanogr., 41(3), 540–548, 1996.
Sedlak, D. L. and Hoigne, J.: The role of copper and oxalate in the redox cycling of iron in atmospheric waters, Atmos. Environ., 27A(14), 2173–2185, 1993.
Stookey, L. L.: Ferrozine – a new spectrophotometric reagent for iron, Anal. Chem., 42(7), 779–781, 1970.
Sunda, W. and Huntsman, S.: Effect of pH, light, and temperature on Fe-EDTA chelation and Fe hydrolysis in seawater, Mar. Chem., 84, 35–47, 2003.
Tanaka, Y., Hurlburt, A., Angelhoff, L., and Skoryna, S.: Application of Algal Polysaccharides as in vivo Binders of Metal Pollutants, Proceedings of the International Seaweed Symposium, 7, 602–604, 1971.
Theis, T. L. and Singer, P. C.: Complexation of Iron(ll) by organic matter and its effect on Iron(ll) oxygenation, Environ. Sci. Technol., 8, 569–573, 1974.
van den Berg, C. M. G.: Evidence for organic complexation of iron in seawater, Mar. Chem., 50, 139–157, 1995.
Viollier, E., Inglett, P. W., Hunter, K., Roychoudhury, A. N., and Van Cappellen, P.: The ferrozine method revisited: Fe(II)/Fe(III) determination in natural waters, Appl. Geochem., 15(6), 785–790, 2000.
Voelker, B. M. and Sedlak, D. L.: Iron reduction by photoproduced superoxide in seawater, Mar. Chem., 50, 93–102, 1995.
Waite, T. D., Rose, A. L., Garg, S., and Fujii, M.: Superoxide-mediated reduction of ferric iron in natural aquatic systems, Geochim. Cosmochim. Ac., 70(18), A681–A681, 2006.
Weber, L., Völker, C., Oschlies, A., and Burchard, H.: Iron profiles and speciation of the upper water column at the Bermuda Atlantic Time-series Study site: a model based sensitivity study, Biogeosciences, 4, 689–706, 2007.
Yocis, B. H., Kieber, D. J., and Mopper, K.: Photochemical production of hydrogen peroxide in Antarctic Waters, Deep-Sea Res. I, 47(6), 1077–1099, 2000.
Yuan, J. and Shiller, A. M.: Determination of subnanomolar levels of hydrogen peroxide in seawater by reagent-injection chemiluminescence detection, Anal. Chem., 71(10), 1975–1980, 1999.
Yuan, J. and Shiller, A. M.: The distribution of hydrogen peroxide in the southern and central Atlantic ocean, Deep-Sea Res. II, 48, 2947–2970, 2001.
Zafiriou, O. C.: Chemistry of the superoxide radical (O$_2^-)$ in seawater, I. pK*$_\rm asw$ (HOO) and uncatalyzed dismutation kinetics studied by pulse radiolysis, Mar. Chem., 31, 31–43, 1990.
Zepp, R. G. and Cline, D. M.: Rates of direct photolysis in aquatic environment, Environ. Sci. Technol., 11(4), 359–366, 1977.