Bioinspired cell silicification of the model diatom Phaeodactylum tricornutum and its effects on cell metabolism

Biosilicification enhances the mechanical strength and chemical stability of organisms. Diatoms are the natural model for studying cell silicification, with the model diatom Phaeodactylum tricornutum being known as the only species that could transition from slightly silicified cells to silicified cells under environmental stress. In this study, single-cell sequencing was employed to investigate the wild-type P. tricornutum strain (WT-Pt) without cell silicification and the engineered strain (SG-Pt) with silicified cells. Our results indicate that SG-Pt exhibits clearly cellular clustering and enhanced iron metabolic function compared to WT-Pt. We further utilize biomimetic techniques to explore the impact of artificial silicification on P. tricornutum. The silicified cells show enhanced resistance to freezing and UVC irradiation conditions. Transcriptomic analysis demonstrated the up-regulation of photosynthesis with pigment accumulation in silicified cells. This work reveals key characteristics of diatoms under artificial biosilicification and provides critical insights into cell metabolism for promoting the development of hybrid living materials, which aligns with the United Nations sustainable development goal (SDG) 12 (Responsible Consumption and Production) by promoting sustainable biomaterials, and SDG 13 (Climate Action) by enhancing carbon sequestration efforts.