DETERMINATION OF TRACE ELEMENTS IN EUGLENA GRACILISZ AND ITS BLEACHED MUTANT STRAINS

Abstract

Two types of bleached mutant strains were isolated from a culture of wild-type Euglena gracilis Z strain. These mutant strains formed yellow and white colored colonies, named Y 1 ZSmL and W 1 ZSmL , respectively. The losses of chlorophyll a in both mutant strains were found from the evaluation of chlorophyll a concentrations. To elucidate physiological effects due to the chlorophyll a loss, cell growth and the amounts of trace elements ( Al , P , S , K , Ca , Fe , Cu , and Zn ) in each strain were studied. The obtained data for mutant strains were compared with those for wild-type Z strain. Cell growth of each strain differed and the abundances of cells were consequently high, decreasing in the order of Z , Y 1 ZSmL , and W 1 ZSmL . The amounts of all elements except S in mutant strains were significantly lower than those in the Z strain. Differences between Y 1 ZSmL and W 1 ZSmL were found only in the amount of Cu . Copper, therefore, would be one of the factors causing differences in the color of the colonies and the growth of cells between both mutant strains.