Functionalized Tyrosinase-Lignin Nanoparticles as Sustainable Catalysts for the Oxidation of Phenols

Abstract

Sustainable catalysts for the oxidation of phenol derivatives under environmentally friendly conditions were prepared by the functionalization of lignin nanoparticles with tyrosinase. Lignin, the most abundant polyphenol in nature, is the main byproduct in the pulp and paper manufacturing industry and biorefinery. Tyrosinase has been immobilized by direct adsorption, encapsulation, and layer-by-layer deposition, with or without glutaraldehyde reticulation. Lignin nanoparticles were found to be stable to the tyrosinase activity. After the enzyme immobilization, they showed a moderate to high catalytic effect in the synthesis of catechol derivatives, with the efficacy of the catalyst being dependent on the specific immobilization procedures.

Spherical lignin particles: a review on their sustainability and applications

“…applications already proven for other forms of lignin, but where spherical particles could give an advantage. Focusing on the size and shape of the particles introduce totally novel lignin applications, including drug delivery [6][7][8][9][10][11] and enzyme immobilization 12,13 for biocatalysis.…”

“…The application of spherical lignin particles in biomedical applications has been recently reviewed 17 and will hence not be further discussed here. Some other interesting applications of LNPs are as templates for carriers and for enzyme immobilization 12,13,158,159 polymer composites and blends, 160 precursors for carbonaceous materials [161][162][163] and metalorganic particles, 164 agglomeration agents to facilitate virus removal in water purification, 165 and hybrid lignin-fatty acid capsules as phase-change materials for thermal energy storage. 70 These examples exemplify that spherical lignin par-ticles may find use in a plethora of versatile and even unexpected applications.…”

Lignin for Nano‐ and Microscaled Carrier Systems: Applications, Trends, and Challenges

“…Additionally, due to the slow rate of biodegradation, lignin can contribute to maintaining the soil carbon balance . Besides pesticides, there are a few studies that used lignin‐based materials for enzyme immobilization and delivery of active pharmaceutical ingredients …”

“…Different release profiles observed with low and high amounts of protein cargo indicated its entrapment in the bulk matrix besides adsorption on the surfaces. Another type of enzyme entrapped in an LNP matrix is tyrosinase, which catalyzes oxidation of tyrosine and a number of other phenolic substances . The activity‐based immobilization yield at a 12 wt % LC was 69 %, which is roughly similar as the values reported for RNase A at comparable LCs .…”

“…The activity‐based immobilization yield at a 12 wt % LC was 69 %, which is roughly similar as the values reported for RNase A at comparable LCs . As opposed to the physically entrapped enzyme inside LNPs, systematically higher catalytic activity in oxidative conversion of 4‐methylphenol was achieved with tyrosinase adsorbed on LNPs …”