Effects of destruction of Euglena gracilis by ultrasonic cavitation

Abstract

Abstract Euglena gracilis has attracted attention because it contains the polysaccharide paramylon. In this study, we aimed to destruct E. gracilis by applying ultrasonic cavitation and to elucidate the mechanism. We also examined the breakdown of paramylon particles and attempted to extract paramylon nanofibers. It was suggested that the damage caused by ultrasonic waves was frequency dependent and influenced by the size ratio of the cell to cavitation bubbles, yield strength, and inhibition of cavitation bubble growth in suspension. It is also assumed that the cell destruction rate decreased because it was also dependent on the initial cell density, and an increase in the initial cell density resulted in a decrease in acoustic pressure. The fracture strength of the paramylon particles was much greater than the microjet stress at the acoustic power used in this study, and the paramylon particles did not fracture.