Estimating bioavailability of soil particulate phosphorus to Microcystis aeruginosa
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Bioavailable phosphorus has been reported to include not only phosphorus in dissolved form but also the fraction of particulate phosphorus that is readily usable. Here, a chemical extraction scheme in combination with an algal bioassay was conducted to estimate the potential bioavailability of particulate phosphorus in soil collected from a Chinese cabbage field. Microcystis aeruginosa was cultured in a medium containing the soils sequentially extracted with 1 M NH4Cl, 0.11 M bicarbonate dithionite, 1 M NaOH, and 0.5 M HCl as the sole source of phosphorus. Analyses of chlorophyll-a, suspended solids, particulate organic carbon, and particulate organic nitrogen showed that M. aeruginosa could utilize some of the phosphorus present in each soil extract. These results imply that bioavailable phosphorus includes not only aluminum/iron-bound P and clay-bound P but also carbonate/apatite-bound P and residual P which have been considered not to be available to algae.
KeywordsParticulate phosphorus Bioavailable phosphorus Microcystis aeruginosa Cyanobacteria Sequential phosphorus extraction
This research was financially supported by the Environment Research and Technology Development Fund (B-0908) of the Ministry of the Environment, Japan.
- Ekholm P, Yli-Halla M, Kylmälä P (1991) Availability of phosphorus in suspended sediments estimated by chemical extraction and bioassay. Verh Internat Verein Limnol 24:2994–2998Google Scholar
- Kasai F, Kawachi M, Erata M, Watanabe M, Shimizu A, Mori F, Yumoto K, Moriya M, Ishimoto M (2004) List of strains. Research report from the National Institute for Environmental Studies Japan 182:50Google Scholar
- Pacini N, Gächter R (1999) Speciation of riverine particulate phosphorus during rain events. Biogeochemistry 47:87–109Google Scholar
- van Eck GTM (1982) Forms of phosphorus in particulate matter from the Hollands Diep/Haringvliet, The Netherlands. Hydrobiologia 92:665–681Google Scholar