Release Of Amino Acids From Microcystis Aeruginosa And Its Contributions To Organic Matter In The North Part Of Lake Taihu

In order to understand the influence of blooming of Microcystis aeruginosa on the contents and sources of organic matter, amino acid in the overlying water, water samples from the eutrophic Meiliang Bay, north part of Lake Taihu, were collected. Taihu lake is a typical shallow lakes in our country, this article in view of the eutrophication of lakes influence on water environment, blooms outbreak from patina microcystin algae in water body and the contribution to the influence of organic matter and amino acids, organic matter of lake algae growth.In order to understand the influence of blooming of microcystis aeruginosa on the contents and sources of organic matter, amino acid in the overlying water, water samples from the eutrophic Meiliang Bay, north part of Lake Taihu,were collected on April and November. And then, the growth process of microcystis aeruginosa was simulated in these water samples in laboratory. The influences of release of amino acid from microcystis aeruginosa on nutrients, amino acid and organic matter(OM)of the water were analyzed. Concents of fifty amino acid including D and L of amino acid were determined by the pre-column derivatization with o-phthaldialdehyde(OPA)combined with HPLC. And then, the contributions of amino acid and organic matter produced by microcystis aeruginosa to the organic matter, total carbon(TC), and total nitrogen(DTN) were discussed. The April results showed that the contributions of microcystis aeruginosa derived amino acid to TC and DTN in the overlying water was25~35% and 35~80%, respectively.The November results showed that the contributions of microcystis aeruginosa derived amino acid to TC and DTN in the overlying water was29~44% and 47~80%.Concentration of the refractory amino acids(glycine, Serine, alanine and lysine) was at 60.4 μmol/L, which was much higher than concentration(40.9 μmol/L)of degradable amino acids(tyrosine, phenylalanine, glutamic acid and arginine).Contributions of bacterial amino acids to the overlying water varied from 22% to 9%.These results would be fundamental to understand the contributions of algae blooming to endogenesis OM and nutrients, which would be favor to understand the cycling of nutrients in lakes.Meanwhile, comparing with the composition of THAAs in sediments and water from LakeTaihu, the algae were generally aligned with sediments and very different with water.