Biotransformation of essential oil composition of Zanthoxylum limonella by the fungus Pleopunctum pseudoellipsoideum provides the products with enhanced antimicrobial activities

Abstract

Microbial biotransformation presents an alternative technology for enhancing more valuable bioproducts. This study utilized three fungi including Pleopunctum pseudoellipsoideum, Stagonosporopsis pini, and Thyrostroma jaczewskii to biotransform Zanthoxylum limonella essential oil composition. The essential oil composition of Z. limonella treated with these fungi was analyzed by gas chromatography-mass spectrometry. Z. limonella oil treated with the fungus T. jaczewskii gave cryptone, neoiso-verbanol, and dehydro-linalool as the major compounds. P. pseudoellipsoideum treatment resulted in the transformation of linalool, cryptone, and thymol, while treatment with the fungus S. pini yielded major transformed compounds such as citronellic acid, cis-limonene oxide, and eucarvone. Varied enzymes produced by each fungus led to diverse transformed volatile profiles. Principal Coordinate Analysis (PCoA) was employed to analyze the volatile profiles of the transformed essential oils, effectively highlighting the distinct nature of fungal biotransformation. Antibacterial activities of the essential oils obtained from all treatments were tested. The Z. limonella oil treated with P. pseudoellipsoideum exhibited the highest antibacterial activity, followed by S. pini and T. jaczewskii, in comparison to pure Z. limonella oil. The results suggest the potential biocatalytic properties of these fungi as tools for enhancing novel value-added bioactive compounds for food and pharmaceutical applications.