Biotransformation of limonene: pathways, biocatalysts, and applications

Biotransformation of limonene is considered as a promising approach for the production of bioactive compounds. These compounds with excellent aroma characteristics and health benefits, such as perillyl alcohol, carvone, and α-terpineol, have great market potential in food, fragrance, cosmetics, pharmaceutical, and agricultural industries. Here, we summarize the products and pathways of limonene biotransformation and highlight the biocatalysts involved in this bioprocess. Numerous microorganisms (e.g., fungi, bacteria and microalgae), enzymes isolated from these microorganisms (e.g., cytochrome P450 enzyme, dehydrogenase, epoxide hydrolase, etc), as well as recombinant cells expressing these enzymes, can degrade and transform limonene into valuable products. Additionally, the extraction and purification of these products from fermentation broth, and their industrial applications are introduced. Finally, the future prospects of limonene biotransformation are discussed.