Low power ultrasound treatment for the enhanced production of microalgae biomass and lipid content

The present study demonstrated the effect of ultrasound treatment on biomass, lipid and total lipid production of Scenedesmus sp. The microalga used in this study was treated with different ultrasonic power (0-50 W), ultrasonic time interval (0-5s) and time (0-10 min). The significant improvement on biomass and lipid content was achieved at 20 W ultrasonic power, 2 s ultrasonic time interval and 4 min ultrasound. The overall lipid production was increased from 0.76 to 1.31 g/L under optimized ultrasonic conditions. On other hand, the Chl-a, carotenoid contents and oxygen evolution rate were also increased after the ultrasonic treatment with subsequent improvement in the efficiency of light capturing capacity, defense mechanism and oxygen evolution rate of cells leading to enhanced biomass and lipid production. The optimized ultrasound treatment enabled Scenedesmus sp. to increase its biomass, lipid and total lipid production. Hence proper ultrasound treatment on microalgae is an effective method improve the biomass and lipid content considerably.