The effects of ionizing radiation on the cell wall of microalgae Chlorella sorokiniana – TEM study

Abstract

Cell wall of C. sorokiniana is composed of trilaminar sheath (TLS electron translucent line inserted between two electron dense lines; the outermost layer is a mature mother wall, while the thin inner layer is a daughter wall), and fibrilar cell wall. It is noteworthy that the obtained diameters for untreated microalgae were in accordance with available data. The analysis of TEM micrographs showed that there were no significant changes in the thickness of TLS for any of the used doses. However, the diameter of fibrillar wall was increased in response to irradiation for microalgae exposed to 1 Gy and 2 Gy. The thickness of cell wall in microalgae exposed to 5 Gy was not significantly different than in controls. A similar trend was observed by gravimetry of dry cell wall isolates normalized to biomass. It is important to note that no effects of radiation on biomass, at doses applied here, could be observed.