Sustainable biolipids-to-alkane conversion: A cascade biocatalysis strategy with enhanced photobiocatalytic efficiency

The development of sustainable biofuels is critical for achieving carbon neutrality and reducing reliance on fossil fuels. Biolipids, primarily composed of triglycerides abundant in various biomass feedstocks, can undergo hydrolysis to yield free fatty acids (FFAs). These FFAs serve as substrates for photodecarboxylase (CvFAP), which utilizes blue light as an energy source to efficiently convert FFAs into C1-shortened alkanes without the need for costly cofactors, such as NADPH offering a green and cofactor-independent solution for biofuel production. However, conventional whole-cell transformation systems suffer from poor light penetration, limited enzyme-substrate interactions, and lipase-induced membrane damage, reducing catalytic efficiency. To overcome these limitations, a CvFAP-lipase cascade system was integrated within a three-liquid-phase system (TLPS) was developed. TLPS generates microdroplets that expand interfacial areas, improving mass transfer and enzyme accessibility. Additionally, it enhances light penetration, maximizing photodecarboxylase activation. Furthermore, TLPS shields Escherichia coli cell membranes from lipase-induced degradation, ensuring sustained catalytic activity. As a result, this TLPS-based photobiocatalytic cascade system achieves alkanes yield exceeding 90%, surpassing conventional approaches in both efficiency and scalability. This work presents a novel enzymatic platform for high-yield biofuel production, integrating interfacial engineering, enzyme protection, and enhanced light utilization within a single scalable system. The TLPS strategy provides a cost-effective, sustainable solution for converting biomass-derived fatty acids into high-value alkanes, with promising implications for renewable energy and sustainable aviation fuel production.