Effect of photodissolution of iron oxide nanoparticles on lipid droplet formation in diatoms
Anastasiia Ivleva1, Dmitrii Tsiurko1, Igor Sergeev1, Maria Blindman1, Ekaterina Moiseeva1, Sergei German1, Julijana Cvjetinovic1, Dmitry Gorin1; 1Center for Photonic Science and Engineering, Skolkovo Institute of Science and Technology, Moscow, Russia
Abstract
Diatoms are key primary producers in aquatic ecosystems and drive global carbon cycle and oxygen production, but their productivity is often limited by iron availability. In this work iron oxide nanoparticles (NPs) as an iron source for diatoms were explored, focusing on the photodissolution — a light-driven process that releases bioavailable iron ions into the surrounding medium — and iron uptake by freshwater and marine algae cells modified with different concentrations of iron-oxide NPs (from 1 mg/L to 100 mg/L). Results showed that iron release is enhanced under mildly acidic conditions (pH 3.5–5.5), facilitated by acetate buffer and citric acid, reducing NP aggregation during irradiation. Under phytolamp irradiation, the freshwater diatom A. formosa consumed iron ions released from 20 and 50 mg/L iron oxide NPs in the presence of citric acid (2.5 × 10⁻⁴ M and 7.5 × 10⁻⁴ M), with 6.6% of the total iron taken up at 7.5 × 10⁻⁴ M after ~83 hours of irradiation. Lipid accumulation measurements after 31 and 83 hours revealed progressive growth of lipid droplet size under prolonged irradiation. These findings suggest that light-driven dissolution of iron-oxide nanoparticles provides bioavailable iron that supports lipid biosynthesis in diatoms, highlighting their potential for applications in biofuel production and light-responsive bioengineering. This work was supported by Russian Science Foundation (grant № 25-74-00119).
Speaker
Anastasiia Ivleva
Skolkovo Institute of Science and Technology
Russia
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