title: Investigation on the iron-uptake by natural biofilms.
abstract: Biofilms are natural communities of microorganisms living in aquatic ecosystems which play an important role in the biogeochemistry of many inorganic elements, including iron. The present work aimed to study the uptake of iron by natural river biofilms (produced in the laboratory) and to examine the relationships between biofilms and iron in water. For that, biofilms were formed from natural water samples collected at different times of the year. Total content and global localization of iron were determined by a combination of chemical analyses and microscopy, which indicated that iron was systematically distributed throughout the biofilm matrix. Depending on the level of iron uptake, iron was diffuse or present as hot spots, was primarily localized to the fraction ascribed to OM compounds (45-60%) or the residual fraction (∼14-40%). Additional experiments were conducted using iron-organic complexes with different affinities (log K) to study iron uptake according to the speciation. These experiments suggested the association between iron and organic ligands (i.e. depending on the affinity constant) influenced the uptake of iron, but did not control the biofilm affinity for iron, which appeared to be controlled by chemical-kinetic laws.
authors.affiliation: UMR CNRS 7285, Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), Université de Poitiers, ENSIP, Bât. B1 - 1 rue Marcel DORE, 86022 Poitiers Cedex, France.
authors.forename: C
authors.initials: C
authors.lastname: Julien
authors.affiliation: UMR CNRS 7285, Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), Université de Poitiers, ENSIP, Bât. B1 - 1 rue Marcel DORE, 86022 Poitiers Cedex, France.
authors.forename: E
authors.initials: E
authors.lastname: Laurent
authors.affiliation: UMR CNRS 7285, Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), Université de Poitiers, ENSIP, Bât. B1 - 1 rue Marcel DORE, 86022 Poitiers Cedex, France.
authors.forename: B
authors.initials: B
authors.lastname: Legube
authors.affiliation: UMR CNRS 7285, Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), Université de Poitiers, ENSIP, Bât. B1 - 1 rue Marcel DORE, 86022 Poitiers Cedex, France.
authors.forename: J-H
authors.initials: JH
authors.lastname: Thomassin
authors.affiliation: UMR CNRS 7285, Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), Université de Poitiers, ENSIP, Bât. B1 - 1 rue Marcel DORE, 86022 Poitiers Cedex, France.
authors.forename: L
authors.initials: L
authors.lastname: Mondamert
authors.affiliation: UMR CNRS 7285, Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), Université de Poitiers, ENSIP, Bât. B1 - 1 rue Marcel DORE, 86022 Poitiers Cedex, France. Electronic address: jerome.labanowski@univ-poitiers.fr.
authors.forename: J
authors.initials: J
authors.lastname: Labanowski
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D018441:Biofilms; D002118:Calcium / Q000032:analysis; D007501:Iron / Q000378:metabolism*; D008024:Ligands; D008345:Manganese / Q000032:analysis; D008855:Microscopy, Electron, Scanning; D012825:Silicon / Q000032:analysis; D012996:Solutions
chemical_list: D008024:Ligands; D012996:Solutions; D008345:Manganese; D007501:Iron; D002118:Calcium; D012825:Silicon
keywords: Biofilm; Iron; Natural water; Uptake