An evaluation of iron bioavailability and speciation in western lake superior with the use of combined physical, chemical, and biological assessment

Hassler, CS; Havens, SM; Bullerjahn, GS; McKay, ML; Twissa, MR

An evaluation of iron bioavailability and speciation in western lake superior with the use of combined physical, chemical, and biological assessment

Hassler, CS Havens, SM Bullerjahn, GS McKay, ML Twissa, MR

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Publication Type:: Journal Article
Citation:: Limnology and Oceanography, 2009, 54 (3), pp. 987 - 1001
Issue Date:: 2009-01-01

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Field	Value	Language
dc.contributor.author	Hassler, CS	en_US
dc.contributor.author	Havens, SM	en_US
dc.contributor.author	Bullerjahn, GS	en_US
dc.contributor.author	McKay, ML	en_US
dc.contributor.author	Twissa, MR	en_US
dc.date.issued	2009-01-01	en_US
dc.identifier.citation	Limnology and Oceanography, 2009, 54 (3), pp. 987 - 1001	en_US
dc.identifier.issn	0024-3590	en_US
dc.identifier.uri	http://hdl.handle.net/10453/8510
dc.description.abstract	An iron-dependent cyanobacterial bioreporter (Synechococcus strain KAS101) was used in unison with sizefractionated iron content (.0.45, ,0.45, ,0.02 mm), and chemical characterization of iron complexation (C18 resin column) to elucidate the bioavailable forms of iron present in Lake Superior during periods of inverse thermal stratification (May) and strong thermal stratification (September) of the water column. The results provide evidence of organic complexation of iron in Lake Superior waters. Iron in most sampled water was complexed by organic compounds that behaved like fulvic acids, whereas some samples showed evidence for the presence of siderophore-like compounds. The presence of dissolved organic matter suppressed the cellular luminescence of the bioreporter, indicating an increased iron bioavailability. This effect could result either from the presence of siderophores forming iron complexes that are bioavailable to the bioreporter, or from more indirect effects because of the presence of other organic compounds, such as fulvic acids or polysaccharides. Model ligand additions, iron bioaccumulation, and photo-oxidation of dissolved organic matter were used to assess the bioavailability of organically complexed iron to the bioreporter. A significant fraction of the iron (40- 100%) was bioavailable to the bioreporter. Iron bioavailability was high enough for the bioreporter not to be iron limited in the water collected from Lake Superior. This measure of bioavailability to picocyanobacteria is relevant because picoplankton accounted for the majority of chlorophyll a in Lake Superior during this study. 2009, by the American Society of Limnology and Oceanography, Inc.	en_US
dc.relation.ispartof	Limnology and Oceanography	en_US
dc.relation.isbasedon	10.4319/lo.2009.54.3.0987	en_US
dc.subject.classification	Marine Biology & Hydrobiology	en_US
dc.title	An evaluation of iron bioavailability and speciation in western lake superior with the use of combined physical, chemical, and biological assessment	en_US
dc.type	Journal Article
utslib.citation.volume	3	en_US
utslib.citation.volume	54	en_US
utslib.for	0602 Ecology	en_US
utslib.for	04 Earth Sciences	en_US
utslib.for	05 Environmental Sciences	en_US
utslib.for	06 Biological Sciences	en_US
pubs.embargo.period	Not known	en_US
pubs.organisational-group	/University of Technology Sydney
pubs.organisational-group	/University of Technology Sydney/Faculty of Science
utslib.copyright.status	open_access
pubs.issue	3	en_US
pubs.publication-status	Published	en_US
pubs.volume	54	en_US

Abstract:

An iron-dependent cyanobacterial bioreporter (Synechococcus strain KAS101) was used in unison with sizefractionated iron content (.0.45, ,0.45, ,0.02 mm), and chemical characterization of iron complexation (C18 resin column) to elucidate the bioavailable forms of iron present in Lake Superior during periods of inverse thermal stratification (May) and strong thermal stratification (September) of the water column. The results provide evidence of organic complexation of iron in Lake Superior waters. Iron in most sampled water was complexed by organic compounds that behaved like fulvic acids, whereas some samples showed evidence for the presence of siderophore-like compounds. The presence of dissolved organic matter suppressed the cellular luminescence of the bioreporter, indicating an increased iron bioavailability. This effect could result either from the presence of siderophores forming iron complexes that are bioavailable to the bioreporter, or from more indirect effects because of the presence of other organic compounds, such as fulvic acids or polysaccharides. Model ligand additions, iron bioaccumulation, and photo-oxidation of dissolved organic matter were used to assess the bioavailability of organically complexed iron to the bioreporter. A significant fraction of the iron (40- 100%) was bioavailable to the bioreporter. Iron bioavailability was high enough for the bioreporter not to be iron limited in the water collected from Lake Superior. This measure of bioavailability to picocyanobacteria is relevant because picoplankton accounted for the majority of chlorophyll a in Lake Superior during this study. 2009, by the American Society of Limnology and Oceanography, Inc.

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http://hdl.handle.net/10453/8510