Development of a process for the production of l-amino-acids concentrates from microalgae by enzymatic hydrolysis

► A process for the production of l-amino-acids concentrates from microalgae biomass is developed. ► The core of the process is an enzymatic hydrolysis reaction using commercial enzymes. ► This process enhances the economic viability of microalgae-based biofuels production processes. A process for the production of l-amino-acids concentrates from microalgae biomass by enzymatic hydrolysis has been developed. The process includes pre-treatment for cell-disruption, enzymatic hydrolysis and final separation by centrifugation. Thermal and mechanical cell-disruption methods have been tested, selecting mechanical disruption using bead milling for 30min. The enzymatic hydrolysis was done using the commercial enzymes Alcalase and Flavourzyme. Maximum hydrolysis was obtained for biomass concentrations under 270g/l and previous additional treatment with Viscozyme, reaching a 42% hydrolysis. Repeated reaction steps increased the hydrolysis from 42% (4h) with a single step to 59% (8h) after two successive steps. Further increase of the number of steps had a meagre impact on the global yield. The process widens the portfolio of products that can be obtained from microalgae biomass and is a new possibility to enhance the economic viability of microalgae-based biofuels production processes.