Fungal Laccase-Mediated Enhancement of the Bioactivity of Green Algae Extracts

Biomass derived from green marine macroalgae Ulva sp. is considered a rich source of bioactive compounds. In the present study, we demonstrate the increased bioactivity of a phenolic-rich extract derived from green marine macroalgae Ulva intestinalis after its treatment with fungal laccases from Trametes versicolor and Agaricus bisporus. The phenolic composition of the extract, before and after its enzymatic treatment, was determined through several analytical methods. Furthermore, the antioxidant, enzyme-inhibitory, antimicrobial and cytotoxic activity of enzymatically modified and non-modified extracts was comparatively investigated. Depending on the laccase used, the enzyme-modified extracts exhibited different phenolic content and enhanced bioactivities compared to the non-treated ones. The enzymatically modified extracts presented enhanced antimicrobial, anti-lipoxygenase and anti-collagenase activities, and mild cytotoxicity. These results indicate that the proposed biocatalytic process could be applied to produce green macroalgal natural extracts with enhanced bioactivities paving the way for their implementation in the food, pharmaceutical, and cosmeceutical industries.