Microalgae Chlorella sp. cell disruption efficiency utilising ultrasonication and ultrahomogenisation methods

Abstract

To break cells of the microalga Chlorella sp. two different methods were applied. The objectives of this study involved ultrasonication using an open system (a VCX 130 ultrasonic processor) and a closed (circulatory) system, as well as ultrahomogenisation at different rotation speeds. For the study, non-frozen microalgae biomass and cold-treated biomass (process of lyophilisation) were used. The efficiency of these methods was assessed with regard to the breaking of microalgae cells. The duration of exposure ranged from 1 to 60 min. A maximum microalgae cell disruption efficiency of 52.6% was achieved by applying high-frequency vibrations for 60 min in an open system while using frozen microalgae biomass. Ultrahomogenisation was less efficient when breaking microalgae cells, although efficiency grew as rotation speed increased. With rotation speed of 24,000 rpm and using frozen microalgae biomass, disruption efficiency reached 48.5% within 60 min. Exposure of microalgae suspension to cold increased cell disruption efficiency by approximately 0.34–3.9%