Combined effect of ozone and ultrasound on disruption of microalgal cells

Among several disruption methods tested so far, ozonation and sonication were distinguished from others by their effective cell rupturing ability. In this study, these disruption methods were combined to enhance the retrieval of biofuel feedstock (carbohydrates and lipids) from microalgae. A mixed microalgal culture was subjected to first ozonation, followed by sonication. Compared to the extraction of 22% of total lipids and 47% of total carbohydrates by sole ozonation, the retrieval of algal metabolites reached 59% and 81% of total lipids and carbohydrates, respectively. The optimum process variables were found by means of a response surface modeling and quadratic programming.