Harnessing diatoms for sustainable economy: Integrating metabolic mechanism with wastewater treatment, biomass production and applications

In the context of carbon neutrality, microalgae-based technologies are gaining recognition as a crucial pathway to sustainable development. Diatoms are a major group of eukaryotic algae that contribute significantly to global carbon fixation and exhibit strong adaptability to environmental stresses. Characterized by a silicified cell wall (frustule) and specialized metabolism, diatoms can be used to generate diverse biomass with high economic value. These attributes position them as promising candidates for the simultaneous application of wastewater bioremediation and biomass production. This review provides a comprehensive overview of diatom growth and metabolism, with a particular focus on mixotrophy and metabolic responses to environmental factors. Their potential for bioremediation in aquaculture and food industry wastewater is critically examined. Furthermore, the diverse applications of diatom biomass are explored, including its role in agricultural biofertilization and aquaculture feed supplementation with antimicrobial, disease-preventive, and growth-promoting properties. Notably, the silicified cell wall offers inherent advantages in cost-effectiveness and performance, making it a promising material for applications in catalysis, biosensors, and energy storage. Additionally, a feasibility analysis within the framework of the circular economy underscores the potential of diatoms in expanding the value chain and enhancing resource utilization efficiency. This review aims to deepen the understanding of diatom metabolic mechanisms to optimize cultivation strategies and provide comprehensive insights into diatom-mediated circular economic processes.