Effectiveness of Parachlorella kessleri cell disruption evaluated with the use of laser light scattering methods

The main objective of this study is to demonstrate the possibilities of using laser light scattering methods, dynamic light scattering and laser Doppler electrophoresis, as suitable methods in investigations of algal production biosystems and biotechnology. This paper highlights the innovative use of the dynamic light scattering (DLS) methods for monitoring the destruction of Parachlorella kessleri cells. Additionally, these results indicate electrophoretic mobility as a new parameter to investigate the effectiveness of cell disruption prior to extraction conducted to optimise the biotechnological processes of recovery of microalgal intracellular metabolites. The efficacy of P. kessleri cell disintegration by ultrasound was determined by measurements of the number of cells with the algal cell reduction (CRns), relative mean hydrodynamic diameter (Rdt) and electrophoretic mobility after applying different lengths of ultrasound exposure to a cell suspension. It was found that stationary-phase cells were the most resistant to the ultrasound treatment, especially at low values of the optical density. Both the relative hydrodynamic diameter and the electrophoretic mobility of cells were correlated statistically significantly with the time of sonication (t) and the algal cell reduction. The relationships allowed estimation of the sonication time needed for total cell disruption.