Integration of osmotic shock assisted liquid biphasic system for protein extraction from microalgae Chlorella vulgaris

The aim of this research is to study a sustainable method to recover whole proteins from microalgae Chlorella vulgaris FSP-E using osmotic shock through liquid biphasic flotation (LBF) system. Osmotic shock induces the change in solute concentration around the cell, which results in permeation thus resulting in disruption of cell wall. Various parameters affecting the protein recovery including types of salt, concentrations of salt, types of alcohol, concentrations of alcohol, air flow rates, osmotic shock period and microalgae biomass concentration were studied. The feasibility of recycling and scaling up were also studied. The optimum parameters according to this study was shown to give a protein recovery of 92.98 % with a separation efficiency of 64.91 %, partition coefficient of 1.47 and a volume ratio of 9. Without osmotic shock, these values were obtained to be 84.84 %, 69.68 %, 1.89 and 2.96 respectively. A 5x scale up of the osmotic shock process gives the protein recovery of 91.23 % with a separation efficiency of 82.46 %, partition coefficient of 3.47 and a volume ratio of 1.50. Hence, this novel approach shows a promising design in terms of protein recovery and sustainability in a large scale.