Abstract
In recent years, algae have attracted attention as non-exhaustible resources with the potential to be
used as a substitute for nonrenewable fossil fuels. The source of within the algae cells is in the form of lipids.
On the other hands, algae cause a significant water pollution. One of the more recent developments in
inactivation technology of algae has been the use of ultrasound. A lot of studies to inactivate microorganisms
such as algae in water by ultrasonic cavitation have been reported. Yet despite these reports, there remain many
unanswered questions about the mechanisms of inactivation of microorganisms in water by ultrasound. In this
study, the efficiency of ultrasonic disruption of Chaetoceros gracilis was investigated by applying ultrasonic
waves of 0.02, 0.4, 1.0, 2.2, 3.4, and 4.4 MHz to degassed suspensions to confirm the necessity of cavitation
bubbles.
