окт 17, 2009 | 22:10

Ostroumov S. A., Kolesnikov M. P. Biocatalysis of matter transfer in a microcosm is inhibited by a contaminant: effects of a surfactant on Lymnaea stagnalis. - Doklady Biological Sciences, Vol. 373, 2000, pp. 397–399. [Translated from Doklady Akademii Nauk (DAN), Vol. 373, No. 2, 2000, pp. 278–280]. --Pellet excretion by the gastropods Lymnaea stagnalis feeding on the phytomass of macrophytes (such as Nuphar lutea) was as high as 4–7 mg absolute dry weight per gram wet weight of mollusks per 72 h. Pellet sedimentation contribute to vertical transfer of chemical elements in the ecosystem. The pellet composition varies depending on the species of the plants eaten by the mollusks. When L. stagnalis feed on N. lutea, the pellets contain, in addition to organic and inorganic carbon, nitrogen (N, 2.3–2.9%), phosphorus (P, 0.4–0.5%), and silicium (Si, 1.1–1.9%). The relative silicium content may be 30% higher than in the food phytomass. The surfactant tetradecyltrimethylammonium bromide (TDTMA, 2 mg/L) inhibited pellet production, their accumulation at the bottom of microcosms, and the matter transfer connected with this. The data obtained demonstrated a new aspect of the ecological hazard due to environmental pollution with TDTMA and other quaternary ammonium compounds at sublethal concentrations. According to the author opinion, other contaminants may also suppress pellet production, their accumulation at the bottom, and the matter transfer associated with that. --KEY WORDS: gastropods, Lymnaea stagnalis, Radix ovata, Physa fontinalis, Nuphar lutea, Taraxacum officinale, tetradecyltrimethylammonium bromide, TDTMA, mollusks, pellet sedimentation, vertical transfer, chemical elements, aquatic ecosystem, nitrogen, phosphorus, silicium, Si, ecological hazard, environmental pollution, pollutant, synthetic surfactant, tensides, quaternary ammonium compounds, sublethal concentrations, contaminants, matter transfer, xenobiotics, toxicity, bioassay, microcosm, detritus, feeding rate, invertebrates, water self-purification; --FULL TEXT see: http://scipeople.ru/users/2943391/