title: Structure and activity of lacustrine sediment bacteria involved in nutrient and iron cycles.
abstract: Knowledge of the bacterial community structure in sediments is essential to better design restoration strategies for eutrophied lakes. In this regard, the aim of this study was to quantify the abundance and activity of bacteria involved in nutrient and iron cycling in sediments from four Azorean lakes with distinct trophic states (Verde, Azul, Furnas and Fogo). Inferred from quantitative PCR, bacteria performing anaerobic ammonia oxidation were the most abundant in the eutrophic lakes Verde, Azul and Furnas (4.5-16.6%), followed by nitrifying bacteria (0.8-13.0%), denitrifying bacteria (DNB) (0.5-6.8%), iron-reducing bacteria (0.2-1.4%) and phosphorus-accumulating organisms (<0.3%). In contrast, DNB dominated sediments from the oligo-mesotrophic lake Fogo (8.8%). Activity assays suggested that bacteria performing ammonia oxidation (aerobic and anaerobic), nitrite oxidation, heterothrophic nitrate reduction, iron reduction and biological phosphorus storage/release were present and active in all Azorean lake sediments. The present work also suggested that the activity of DNB might contribute to the release of phosphorus from sediments.
authors.affiliation: IBB - Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus de Gualtar, Braga, Portugal.
authors.forename: Gilberto
authors.initials: G
authors.lastname: Martins
authors.forename: Akihiko
authors.initials: A
authors.lastname: Terada
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Ribeiro
authors.forename: Anuska M
authors.initials: AM
authors.lastname: Corral
authors.forename: António G
authors.initials: AG
authors.lastname: Brito
authors.forename: Barth F
authors.initials: BF
authors.lastname: Smets
authors.forename: Regina
authors.initials: R
authors.lastname: Nogueira
mesh_terms: D000641:Ammonia / Q000378:metabolism; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D058440:Denitrification; D005068:Eutrophication; D005618:Fresh Water / Q000032:analysis / Q000382:microbiology*; D019015:Geologic Sediments / Q000032:analysis / Q000382:microbiology*; D007501:Iron / Q000032:analysis / Q000378:metabolism*; D008969:Molecular Sequence Data; D009566:Nitrates / Q000378:metabolism; D010084:Oxidation-Reduction; D010758:Phosphorus / Q000032:analysis / Q000378:metabolism
chemical_list: D009566:Nitrates; D010758:Phosphorus; D000641:Ammonia; D007501:Iron