Distribution of Zinc in Euglena gracilis Wild and Mutant Cells Cultured in Zinc Enriched Medium as Proved by X-Ray Microanalysis

Abstract

A mutant strain of Euglena gracilis Z isolated in our laboratory is highly tolerant to excess zinc and was proved by X-ray microanalysis to accumulate the element in micro-spherical bodies in the cytoplasm. On the other hand, the wild strain which is less tolerant to zinc had a uniform distribution of zinc within the cell when cultured in the zinc enriched medium. The production of the zincaccumulating globular substances in the mutant cells is considered to be the main protective mechanism against the metal toxicity.