Separation of TAGs from Parachlorella kessleri in wet processing: effect of cell destruction on the performance of the membrane fractionation process
Résumé
The micro-algae biorefinery offers the opportunities to replace traditional raw materials with biomolecules (lipids, proteins, polysaccharides, pigments, etc.) in various industrial sectors such as food, cosmetics, pharmacy, energy or chemistry. The challenge of this research is to adopt innovative strategies for a soft and efficient process to ensure the integrity of fragile molecules and to develop an eco-friendly production. Thus, for large-scale production, a wet processing of biomass has been proposed (Clavijo Rivera et al. 2018) to avoid expensive drying steps and to reduce solvent use compared to classical processes. Biomass wet treatment includes several steps: 1-the biomass harvesting for dewatering, 2-the cell disruption to release the valuable biochemical compounds in the aqueous phase, 3-the membrane fractionation to concentrate and recover the target compounds and 4-the purification. However, the key points needed for its improvement is to understand the interaction between upstream and downstream processes for a better coordination and control. In this context, the effect of bead milling (grinding degree, enzyme activity reduction and antioxidation ect.) on the membrane separation process for the fractionation of triglycerides from Parachlorella kessleri was studied. The filtration performance (flux, retention rate and selectivity) of supernatants issued from clarified suspensions obtained from various upstream disruption conditions were compared. The physico-chemical state of lipids, proteins and total carbohydrates during each step of process were followed. The final parameters were chosen for the best fractionation and selectivity of TAGs with the coordination's between the disruption process (bead milling) and the fractionation process (membrane filtration).