In this study, effects of ultrasonic treatment on Haematococcus pluvialis (H. pluvialis) were investigated. It has been confirmed
that the ultrasonic stimulation acted as stress resources in the red cyst stage H. pluvialis cells containing astaxanthin,
result ing in additional astaxanthin production. With the increase in production of astaxanthin, the average diameter of H.
pluvialis cells increased accordingly. In addition, to determine how ultrasonic stimulation had an effect on the further biosynthesis
of astaxanthin, genes related to astaxanthin synthesis and cellular ROS level were measured. As a result, it was
confirmed that astaxanthin biosynthesis related genes and cellular ROS levels were increased, and thus ultrasonic stimulation
acts as an oxidative stimulus. These results support the notion on the effect of the ultrasonic treatment, and we believe
our novel approach based on the ultrasonic treatment would help to enhance the astaxanthin production from H. pluvialis.