An overview of microalgae biomass as a sustainable aquaculture feed ingredient: food security and circular economy

Abstract

Sustainable management of natural resources is critical to food security. The shrimp feed and fishery sector is expanding rapidly, necessitating the development of alternative sustainable components. Several factors necessitate the exploration of a new source of environmentally friendly and nutrient-rich fish feed ingredients. Microalgal biomass has the potential to support the growth of fish and shrimp aquaculture for global food security in the bio-economy. Algal biorefineries must valorize the whole crop to develop a viable microalgae-based economy. Microalgae have the potential to replace fish meal and fish oil in aquaculture and ensure sustainability standards. Microalgae biomasses provide essential amino acids, valuable triglycerides such as lipids, vitamins, and pigments, making them suitable as nutritional supplements in livestock feed formulations. Fish and microalgae have similar nutritional profiles, and digestibility is a critical aspect of the aquafeed formulation. A highly digestible feed reduces production costs, feed waste, and the risk of eutrophication. Due to low input costs, low carbon footprint, wastewater treatment benefits, and carbon credits from industrial CO 2 conversion, microalgae-based fish and shrimp feeds have the potential to provide significant economic benefits. However, several challenges must be addressed before microalgal biomass and bioproducts may be used as fish feeds, including heavy metal bioaccumulation, poor algal biomass digestion, and antinutrient effects. Knowledge of biochemical composition is limited and diverse, and information on nutritional value is scattered or contradictory. This review article presents alternative approaches that could be used in aquaculture to make microalgal biomass a viable alternative to fish meal.

Fish seed and feed value chains analysis and their critical factors for aquaculture development in Tanzania

“…For the feed value chain, we suggest reducing the high price of ingredients and commercial fish feeds by forging a working collaboration between industrial, commercial fish feed producers, and researchers to develop locally and affordable protein sources such as black soldier fly larvae (Limbu et al., 2022) and algae (Ahmad et al., 2022; Yossa et al., 2021) to replace expensive and limited available fishmeal in feed formulations and production. We recommend the government to continue promoting fish farming in order to build a critical mass for fish farmers to justify investment in large commercial feed plants.…”

Microalgae as a Nutraceutical Tool to Antagonize the Impairment of Redox Status Induced by SNPs: Implications on Insulin Resistance

“…However heterotrophic microalgae can use organic compounds, mainly glucose, as a source of energy [ 109 , 110 ]. In light of these specific characteristics, autotrophic microalgae cultivation is environmentally sustainable as they do not require large amounts of water for their growth and are also capable of using atmospheric CO 2 during photosynthesis, fixing carbon in a plethora of organic molecules while generating oxygen [ 111 ]. The ability of microalgae to fix carbon has been quantified as 1.83 kg of CO 2 per kg of microalgal (bio)mass [ 112 ].…”

From the sea to aquafeed: A perspective overview

“…164 Hence, to guarantee the sustainability of circular use of microorganisms in aquaculture, more effort is needed to optimise the processes and reduce costs of growing, handling, processing and extraction processes. 165 3 | MACROORGANISMS AS AQUACULTURE FEEDS…”