Cadmium and zinc uptake, growth, and primary production in Coscinodiscus granii cultures containing low levels of cells and dissolved organic carbon

摘要: Coscinodiscus granii Gough was cultivated at low cell densities in aged Atlantic sea water containing very little dissolved organic carbon; the enriched with levels of nutrients but no chelators were added. Cadmium additions provided final concentrations 0.1 to 26.5 µg Cd l−1, zinc being kept constant a level 38 Zn l−1. Carrier-free109Cd and65Zn used as tracers for two metals. Growth terms numbers and primary productivity capacity, using the14C uptake rate, followed during exponential growth phase first 5 days experiment then further 3 stationary phase. On each day, metal contents cells determined. 20 l−1 more resulted inhibition whereas 17.5 reduced only slightly. The physiological state influenced heavy-metal per sublethal levels. Dead had higher concentration than living cells. Microscopical observations revealed that just about divide less sensitive given toxic which recently divided. This might have been due different surface/volume ratios.