THE EFFECTS OF METAL MIXTURE IN THE CULTURE MEDIUM ON THE GROWTH OF PHAEDACTLYUM TRICORNUTUM UNDER NUTRIENT LIMITATION

The effects of metal mixture in the culture medium on the growth of Phaedactlyum tricornutum under nutrient limitation

Oya S. Okay, Vildan Tüfekçi, Alec Gaines

Energy Systems and Environmental Research Institute, Marmara Research Center, TÜBİTAK, P.O. Box 21, 41470 Gebze, Kocaeli, TURKEY
Marine Science Institute, Middle East Technical University, P.O. Box: 28, 33731 Erdemli, İçel, TURKEY

Abstract

A mixture of copper, zinc, cobalt, manganese and iron was added to the medium in which cultures of Phaeodactylum tricornutum (Bohlin) were grown under nitrate and phosphate limitation. Growth was determined by counting cells, measuring in vivo fluorescence and monitoring 14C uptake. It was found that maximum cell concentrations were reached at concentrations over 5 mg N l-1 and  0.5 mg P l-1 in the media whether or not there was enrichment with metals. The fluorescence intensities, growth rates, 14C uptake rates of the cells and chlorophyll-a: cell ratio in metal enriched media were higher than those in unenriched media.

Keywords: Eutrophication, bioassay, algae, limiting nutrient