Comparison of the relative tolerance of Colpoda resting cysts and vegetative cells to electrostatic exposure

Abstract

The soil protist ciliate Colpoda cucullus forms resting cysts that have extreme tolerance to many environmental stresses. In this study, we show that Colpoda resting cysts, unlike vegetative cells, can survive electrostatic exposure. The viability of vegetative cells fell with the number of electrostatic exposures; cyst viability did not show this response. The morphology of exposed cysts appeared to be essentially normal at the optical microscope level; excysted cells from exposed cysts retained a similar proliferative ability to those of non-exposed cysts, whereas most vegetative cells were fatally damaged by electrostatic exposure.