Unspecific peroxygenases and P450-derived peroxygenases as green biocatalysts driven by HO for sustainable applications: A review.

Unspecific peroxygenases (UPOs) are promising biocatalysts capable of catalysing selective oxygenation of organic substrates using hydrogen peroxide (HO) as the sole oxidant under mild conditions. Sharing a broad substrate range with cytochrome P450 monooxygenases, UPOs function without costly cofactors or auxiliary proteins, making them attractive for industrial biocatalysis. However, limited heterologous expression and poor HO tolerance restrict their broader application. Recent advances in host selection and signal peptide optimisation have significantly improved UPOs production. Simultaneously, various in situ HO generation systems-particularly photobiocatalytic strategies-have enhanced reaction efficiency by stabilising peroxide concentrations. Additionally, efforts to engineer P450s into peroxygenase-like enzymes aim to overcome the limitations of P450s in industrial applications and enhance their utility in organic synthesis. This review systematically summarizes the development of UPOs over the past decade, including technical bottlenecks and future application prospects. The review focuses on heterologous expression, in situ generation of HO, and the modification of P450s to boost peroxygenase activity, providing new ideas for addressing these challenges. In the future, UPOs and P450-derived peroxygenases are anticipated to play an increasingly significant role in green chemistry and organic synthesis.