Integrated biorefinery approach for sequential extraction of lipids, proteins, and carbohydrates with concurrent fatty acid profiling and heavy metal adsorption from residual biomass

This study presents a lab-scale integrated biomass valorization approach for the sequential recovery of value-added biomolecules from Schizochytrium aggregatum biomass, followed by utilization of the residual biomass for heavy metal remediation. The approach was designed to recover lipids, proteins, and carbohydrates sequentially while exploring the potential of the residual biomass for biosorption applications. Lipid extraction achieved a maximum yield of 48 ± 1.1% using ultrasonic probe-assisted extraction, providing higher recovery than the other extraction methods evaluated. Fatty acid profiling revealed docosahexaenoic acid (DHA) and palmitic acid as dominant components, highlighting the biomass potential for nutraceutical and pharmaceutical applications. Sequential extraction of proteins and carbohydrates further enabled comprehensive biomass valorization. Proximate composition and CHNS analysis confirmed efficient biomolecule recovery across fractions. The residual biomass demonstrated effective adsorption of chromium and cadmium ions, supported by surface and structural characterization. Unlike conventional biorefinery strategies focused solely on biomolecule recovery, this integrated waste-minimizing biorefinery approach enhances biomass utilization efficiency and promotes circular bioeconomy principles, aligning with sustainable waste valorization and water remediation strategies. This approach aligns with the United Nations Sustainable Development Goals, especially SDG 12 (Responsible Consumption and Production) and SDG 6 (Clean Water and Sanitation), providing a lab scale framework for industrial and environmental applications.