Effect of dissolved organic matter on the growth of algae, Pseudokirchneriella subcapitata, in Korean lakes: the importance of complexation reactions.
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.
Lee
Jiho
J
Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology, 1 Oryong-Dong, Buk-gu, Gwangju 500-712, Republic of Korea.
Park
Ji Hyung
JH
Shin
Yong Sik
YS
Lee
Byung Cheun
BC
Chang
Nam Ik
NI
Cho
Jaeweon
J
Kim
Sang Don
SD
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*
D003470:Culture Media; D006812:Humic Substances; D008024:Ligands; D009930:Organic Chemicals; D014874:Water Pollutants, Chemical; D004492:Edetic Acid; D007501:Iron