Importance of dissolved organic carbon for phytoplankton nutrition in a eutrophic reservoir

0340601 - BC 2010 RIV GB eng J - Journal Article
Znachor, Petr - Nedoma, Jiří
Importance of dissolved organic carbon for phytoplankton nutrition in a eutrophic reservoir.
Journal of Plankton Research. Roč. 32, č. 3 (2010), s. 367-376. ISSN 0142-7873. E-ISSN 1464-3774
R&D Projects: GA ČR(CZ) GP206/07/P407; GA ČR(CZ) GA206/06/0462; GA ČR(CZ) GA206/05/0007; GA AV ČR(CZ) 1QS600170504
Institutional research plan: CEZ:AV0Z60170517
Keywords : mixotrophy * phytoplankton * PDMPO * DOC * autoradiography * diatoms
Subject RIV: DA - Hydrology ; Limnology
Impact factor: 1.749, year: 2010

We performed 4 experiments with size fractionated phytoplankton organic C uptake in a eutrophic Římov Reservoir. Samples from surface and euphotic depth were incubated at in situ depths in light and dark bottles arrangement with ³H amino acids and glucose. Moreover, we measured silica deposition and chlorophyll content in diatom cells without and with glucose. Phytoplankton uptake of both substrates was low regardless the incubation depth. Thus, mixotrophic nutrition of the phytoplankton was of low importance under natural conditions. However, glucose addition in micromolar concentrations resulted in asignificant increase in diatom silification rates in a light bottle variant. Interestingly, chlorophyll fluorescence in diatom cells markedly decreased after the glucose addition indicating a potential restructuring of cell metabolism to benefit from a remarkably high concentration of available organic C in the environment.
Permanent Link: http://hdl.handle.net/11104/0183811