Characterization of Microalgae Species from Qatar Coastal Waters for Animal Feed Production

Abstract

Food security worldwide is field of major research and investigation to improve and find new resource production systems for a continuously growing world population. The state of Qatar being an arid and with limited arable lands is increasingly reliant on imported food products and has recently engaged extensive efforts to advance its challenging strategy to sustainably enhance its food security. Microalgae found in the local environment and adapted to wide range of environmental conditions are considered promising condidate to play a central role in this food security strategy since no arable land neither freshwater are needed for its cultivation. We aim in this study to identify the species and culture condition for the obtaining of microalgal biomass as source for feedstock production. Tetraselmis and Nannochloris isolates were selected from the Qatar University Culture Collection of Cyanobacteria and Microalgae (QUCCCM) based on preliminary results and extensive available literature review. Salinity and CO2 enrichment experiments were conducted with several levels (i.e. 35, 40 and 45 psu salinities and 3%, 5% and 10% CO2 enrichment), using photobioreactors cultivation system. Results suggest that 35 psu salinity and 5% CO2 enrichment cultivation conditions are favorable for the protein hyper-producer Tetraselmis strain, while 40 psu salinity and 3% CO2 enrichment are more suitable for the lipid hyper-producer Nannochloris strain. Mineral uptake differed between the two species and at some extent between different salinities and CO2 enrichment culture conditions. Tetraselmis contains higher amount of Calcium while Nannochloris contains higher amount of Potassium. Mineral profiles of the two species respond differently to salinity and CO2 enrichment culture conditions. The conducted biochemical characterization of the obtained biomass suggests that a feed blending using both Tetraselmis and Nannochloris biomasses would provide high quality products with high protein contents while supplying animals with essential fatty acids (i.e. PUFAs) and mineral ingredients. Recommendations for future research and development efforts are discussed.