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

Abstract

Biomass derived from green marine macroalgae <em>Ulva</em> 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 <em>Ulva intestinalis</em> after its treatment with fungal laccases from <em>Trametes versicolor</em> and <em>Agaricus bisporus</em>. 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.

Laccase-Mediated Oxidation of Phenolic Compounds from Wine Lees Extract towards the Synthesis of Polymers with Potential Applications in Food Packaging

“…A similar result was observed by Spyrou et al where the peaks of the initial phenolic extract were decreased and broadened after enzymatic-assisted oxidation of the Ulva sp. extract [ 6 ]. The results of the UV-Vis analysis are in line with the results obtained from the Folin–Ciocalteu assay described above, where the dephenolization yields at 1, 2, 6, and 24 h were almost the same, hinting that the oxidation is almost completed at the first hour of enzymatic treatment.…”

“…The total phenolic content (TPC) of the reactions, before the enzymatic polymerization and after the enzymatic polymerization, was estimated with the Folin–Ciocalteu method, as described by Spyrou et al, and adapted at a total volume of 200 μL [ 6 ]. A standard curve of gallic acid was used to express the results as mg of gallic acid equivalents (GAE) per mL (mg GAE mL −1 ).…”

“…The DPPH assay was conducted according to previous works [ 6 , 20 ]. A methanolic solution of DPPH (0.1 mM) was prepared, and the tested concentration of the polymers was 10–150 μg mL −1 .…”

“…Laccase from T. versicolor (TvL) is well characterized as a biocatalytic tool for the oxidation of different substrates, depending on its redox potential. Moreover, TvL is applied in enzymatic oligomerization/polymerization of phenolic compounds, as an alternative to chemical methods [ 1 , 6 , 7 ], offering the advantages of the absence of toxic chemicals, controlled reaction conditions, and a wide range of the initial substrates [ 8 ]. This oligo- or polymerization reaction is conducted via two main stages: the enzyme-catalyzed generation of phenoxy radicals and the spontaneous non-enzymatic oxidative coupling [ 9 ].…”

Valorization of Olive Pomace Using Ultrasound-Assisted Extraction for Application in Active Packaging Films

“…The total phenolic content (TPC) of the extracts was measured spectrophotometrically based on the Folin–Ciocalteu’s colorimetric assay, as described by Spyrou et al [ 63 ], adjusting the reaction solution to a final volume of 200 μL. Briefly, each sample was prepared in the appropriate solvent at a final concentration of 1 mg mL −1 .…”