KVAL: Innovative strategies for cell wall disruption towards enhanced extraction and digestibility of value-added microalgal bioactives

Cell wall disruption of microalagae is a critical first step for recovery and increased digestibility/bioavailability of key target compounds such as lipids and proteins for aquaculture food/feedstock, pigments, vitamines and high added-value bio-compounds such as Astaxanthin (red pigment used in salmon feed). Conventional cell wall disruption methods, e.g. mechanical shearing or heat treatment with organic solvents, pose environmental/health risks and may cause denaturation/transformation of bioactives, besides low extraction yield and high energy consumption. In collaboration with ELEA GmbH, Germany, Nofima is currently developing a new innovative concept for cell wall disruption based on the combined application of Cold Plasma and Pulsed Electric field. The combination of those two innovative technologies was shown to significantly increase extraction yields of proteins and pigments from Chlorella, one of the microalgae with the most rigid cell wall structure. The DISRUPT project aims to further develop and optimise this new cell-wall disruption method for treatment of algal biomass. First steps in order to provide necessary key information on the potential of the concept for cell wall disruption were taken with an NFR qualification project. Future funding will be used to upscaling of the production methods, extended screening of the biomass resources and production of a pilot unit for biomass processing.

Microalgae is widely considered as a potential key ressource for the development and upscaling of aquaculture feed based on renewable ingredients. Microalgae can be cultivated using waste streams, such as biowaste, excess nutrients from aquaculture and CO2 from industry. During this project, we have been in contact with industries interested in microalgae for their pigments, their nutritional value and their capacity to eliminate residues in water waste treatment. Industrial initiatives are relatively small scale but there is considerable potential for growth for the Norwegian Bioeconomy sector. Cell wall disruption is the critical first treatment stage for recovery of bioactive compounds and considered as one of the major botttlenecks for industrial development of algal-bioreffinery concepts. The innovative concept proposed in this project is safe, eco-friendly and cost-effective strategy that will open up significant new industrial applications for use of microalagae as a renewable feed ingredients with high digestibility and as raw material for high quality bioactive production.