Microalgae as a sustainable feed source and a bioremediation strategy for agro-industrial effluents

Abstract

Recently, microalgae have emerged as nutrient-dense feed sources with substantial benefits for animal health and productivity. They contain high-quality protein, essential fatty acids, vitamins, minerals, and bioactive compounds that help to improve the quality and quantity of animal-derived products, including milk, meat, and eggs, thereby presenting a sustainable alternative to conventional feed sources. Additionally, their immunomodulatory properties enhance gastrointestinal health, disease resistance, growth performance, and reproductive outcomes in livestock. Beyond animal nutrition, microalgae bio-actives hold value in cosmetics, pharmaceuticals, and nutraceuticals, showcasing their industrial versatility. Microalgae can grow in diverse environments, including wastewater and effluents. Wastewater has the potential to substitute synthetic media used in cultivation, providing nutrient-rich biomass that can serve as an alternative feed source. Cultivating microalgae in effluents/wastewater has emerged as a sustainable and eco-friendly approach for wastewater treatment and biomass production. However, high production costs and scalability constraints limit its widespread application. This review highlights the cultivation of microalgae using different wastewater sources as an alternative substrate and their nutritional value, as well as the health and environmental benefits of using it in animal feed. It also discusses the current challenges and examines the potential of microalgae to transform animal agriculture while contributing to a circular bioeconomy.