Metabolism of trace elements in Euglena gracilis using the multitracer technique

Abstract

The incorporation and the excretion of multitracers in green Euglena gracilis and yellow one have been investigated. Yellow Euglena, deficient of chlorophylls, was prepared by treating green Euglena with streptomycin. Both of green and yellow Euglena were cultured in the same condition from 27 to 30 C. The cells were separated, then suspended in an incorporation medium. The experimental procedures for extracting cell samples and thereafter for measuring the incorporation rate and the excretion rate by Ge gamma detector were briefly described. As to the incorporation rate of the ions of Zn, Se, Mn and Co into the green Euglena, the incorporation rate was remarkably raised during the first few hours, and then showed slowing down of incorporation. In the yellow Euglena, the behavior of incorporation rates after its initial rapid rise were different from those in green Euglena, and the decrease of the incorporation was shown after 25 hours. The excretion rates of Zn, Se, Mn and Co were similar with each other in the green cells, and mostly retained in the cells for longer than 50 hours. However, Mn in the yellow cells was rapidly excreted comparing with the other elements.

緑色ミドリムシ(Euglena gracilis)と黄色ミドリムシ体内の多重トレーサの取込みと排泄を検討した。クロロフィルが欠乏した黄色ミドリムシは緑色ミドリムシをストレプトマイシンで処理して調製した。緑色および黄色ミドリムシは共に27?30度Cの同一条件で培養した。細胞を分離し、取込み培養基内に懸濁させた。細胞試料の抽出、その後のGeガンマ線検出器による取込み率と排泄率測定の実験手順を簡略に記述した。緑色ミドリムシへのZn、Se、Mn、Coのイオンの取込み率は最初の数時間の間に著しく上昇し、その後取込み速度の低下を示した。黄色ミドリムシでは最初の取込み率急上昇後の挙動は緑色ミドリムシの挙動とは異なり、25時間以後は取込みの減少を示した。Zn、Se、Mn、Coの排泄率は緑色細胞内では互いに類似しており、ほとんどが50時間以上細胞内に滞留した。しかし、黄色細胞内のMnの排泄速度は他の元素に比較して速かった。