The effect of heavy metals on blue-green alga

Abstract

In this study, the effect of nickel, arsenicand cadmium on the growth and ~trogen fixation abilityof the cyanobacterium, Anabaena cylindrica was examined.Algae were incubated in media containing Ni asnickel chloride (NiC1 Z.6H ZO), As as sodium arsenate(Na ZHAs04 .7H ZO), and Cd as cadmium chloride (CdC1 Z)in solution.,The growth was measured spectrophotometricallyand nitrogen fixation ability was measured by theacetylene reduction technique using gas chromatography.Growth was not effected by the presence of metalions at given concentrationS(except of 5 ppm Ni ).However acetylene reduction activity was inhibitedby the presence of nickel although this was reversedin the presence of cadmium or arsenic.