Green extraction of active compounds in marine microalgae

Marine microalgae serve as photosynthetic cellular factories for producing active natural products. Currently, compounds such as polysaccharides, proteins, lipids, pigments, and polyphenols extracted from marine microalgae exhibit anti-inflammatory, antimicrobial, and antitumor activities. Components such as pigments and unsaturated fatty acids in marine microalgae possess antioxidant properties and contribute to meeting the nutritional needs of the human body. Extracting these active compounds from marine microalgae requires pretreatment. Methods such as ball milling, high-pressure homogenization, microwave, ultrasound, ionic liquids, and enzymatic methods can disrupt the cell walls of marine microalgae, thereby enhancing extraction efficiency. Green extraction processes include pressurized liquid extraction, supercritical extraction, ionic liquids, and deep eutectic solvents. This paper identifies the current bottlenecks in these pretreatment and extraction processes and proposes potential solutions. In silico simulation and artificial intelligent methods are helpful to design new green solvents and separation processes. Further development of green extraction processes for marine microalgae will advance the application of blue biotechnology.