title: Effect of dissolved organic matter on the growth of algae, Pseudokirchneriella subcapitata, in Korean lakes: the importance of complexation reactions.
abstract: The objective of this study was to investigate the effect of dissolved organic ligands, such as EDTA, humic acids, hydrophobic and hydrophilic fractions of dissolved organic matter (DOM), on the growth of Pseudokirchneriella subcapitata in cultured media and natural lake waters. The growth of algae was gradually increased on the addition of dissolved organic ligands, but markedly declined at high concentrations, due to reduced bioavailable iron concentrations (e.g., Fe3+ and Fe'--inorganic ferric iron). The results demonstrated that the high growth rates of P. subcapitata were correlated with the hydrophobic, but not hydrophilic, DOM from five lakes, spiked under the nutrients-controlled conditions. This was attributed to the role of DOM in controlling the bioavailable iron due to complexation of Fe(III) with -COOH and -OH functional groups on the hydrophobic DOM. Therefore, the hydrophobic DOM, as chelating agent, is a biologically important component in the lake waters, which affects the algal growth by interacting with bioavailable iron in the lake water and can change the results of bioassay experiments.
authors.affiliation: Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology, 1 Oryong-Dong, Buk-gu, Gwangju 500-712, Republic of Korea.
authors.forename: Jiho
authors.initials: J
authors.lastname: Lee
authors.forename: Ji Hyung
authors.initials: JH
authors.lastname: Park
authors.forename: Yong Sik
authors.initials: YS
authors.lastname: Shin
authors.forename: Byung Cheun
authors.initials: BC
authors.lastname: Lee
authors.forename: Nam Ik
authors.initials: NI
authors.lastname: Chang
authors.forename: Jaeweon
authors.initials: J
authors.lastname: Cho
authors.forename: Sang Don
authors.initials: SD
authors.lastname: Kim
mesh_terms: D000818:Animals; D001681:Biological Assay; D001682:Biological Availability; D000460:Chlorophyta / Q000187:drug effects* / Q000254:growth & development* / Q000378:metabolism; D003470:Culture Media; D004492:Edetic Acid; D005618:Fresh Water / Q000737:chemistry* / Q000382:microbiology*; D006812:Humic Substances; D057927:Hydrophobic and Hydrophilic Interactions; D007501:Iron / Q000737:chemistry*; D007723:Korea; D008024:Ligands; D009930:Organic Chemicals / Q000737:chemistry / Q000633:toxicity*; D012995:Solubility; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity*
chemical_list: D003470:Culture Media; D006812:Humic Substances; D008024:Ligands; D009930:Organic Chemicals; D014874:Water Pollutants, Chemical; D004492:Edetic Acid; D007501:Iron