Self-assembled microalgae-photosensitized biohybrids enabling solar-driven directed phosphate conversion form...

Semi-artificial photosynthetic systems that integrate photocatalysts with living microbial cells represent an emerging and promising approach for the degradation and conversion of organophosphorus pesticides (OPs). Here, we utilized the strong electrostatic interactions between Fe@C and Chlorella sorokiniana (C. sorokiniana) to construct a C. sorokiniana-Fe@C biohybrid system. This platform was applied to evaluate light-driven malathion conversion efficiency and elucidate underlying conversion mechanisms. Experimental results demonstrated 93.6 % malathion removal under illumination, with the biohybrid system exhibiting 9.2 times and 2.1 times higher removal efficiency compared to Fe@C and C. sorokiniana, respectively. Operational stability tests confirmed that the biohybrid system maintained a malathion removal efficiency of 90.0 ± 0.5 % over seven consecutive cycles, indicating high durability and recyclability. Mechanistic studies revealed that Fe@C efficiently harvests photons and delivers photogenerated electrons to C. sorokiniana, concurrently enhancing Photosystem II (PSII) activity, ATP synthesis, and intracellular levels of reduced nicotinamide adenine dinucleotide phosphate (NADPH). These electrons and reducing equivalents supply the necessary energy to activate key enzymes, particularly carboxylesterases (CEs) that catalyze the targeted hydrolysis of malathion into inorganic phosphate, enabling selective conversion and phosphorus recovery. This study successfully achieves simultaneous OPs degradation and resource utilization, establishing an innovative paradigm for sustainable pollutant remediation and circular resource strategies.