Phospholipase D Immobilization on Lignin Nanoparticles for Enzymatic Transformation of Phospholipids

Abstract

Lignin nanoparticles (LNPs) are promising components for various materials, given their controllable particle size and spherical shape. However, their origin from supramolecular aggregation has limited the applicability of LNPs as recoverable templates for immobilization of enzymes. In this study, we show that stabilized LNPs are highly promising for the immobilization of phospholipase D (PLD), the enzyme involved in the biocatalytic production of high‐value polar head modified phospholipids of commercial interest, phosphatidylglycerol, phosphatidylserine and phosphatidyl‐ethanolamine. Starting from hydroxymethylated lignin, LNPs were prepared and successively hydrothermally treated to obtain c‐HLNPs with high resistance to organic solvents and a wide range of pH values, covering the conditions for enzymatic reactions and enzyme recovery. The immobilization of PLD on c‐HLNPs (PLD‐c‐HLNPs) was achieved through direct adsorption. We then successfully exploited this new enzymatic preparation in the preparation of pure polar head modified phospholipids with high yields (60‐90%). Furthermore, the high PLD‐c‐HLNPs stability allows its recycling for a number of reactions with appreciable maintenance of its catalytic activity. Thus, PLD‐c‐HLNPs can be regarded as a new, chemically stable, recyclable and user‐friendly biocatalyst, based on a biobased inexpensive scaffold, to be employed in sustainable chemical processes for synthesis of value‐added phospholipids.

Overcoming Challenges of Lignin Nanoparticles: Expanding Opportunities for Scalable and Multifunctional Nanomaterials

“…In a follow-up study, HLNPs were used to adsorb phospholipase D, allowing repeated use of this expensive enzyme over four cycles of transformation of phospholipids to polar headgroup-modified derivatives. 55 This approach simplifies the use of LNPs in enzyme immobilization; previously enzyme-coated LNPs have been stabilized by encapsulation in calcium alginate beads for instance, 39 or cationic LNPs coated with chitosan. 44 Both strategies outlined above, using cross-linkers during selfassembly or providing a hydration barrier from fatty acids, are crucial for obtaining functionalizable LNPs and enabling access to lignin-based advanced materials.…”

“…In addition to allowing for dispersion state modification of the HLNPs, this methodology preserves the phenolic groups that are key functionalities defining biodegradability, redox activity, and antimicrobial properties of lignin. In a follow-up study, HLNPs were used to adsorb phospholipase D, allowing repeated use of this expensive enzyme over four cycles of transformation of phospholipids to polar headgroup-modified derivatives . This approach simplifies the use of LNPs in enzyme immobilization; previously enzyme-coated LNPs have been stabilized by encapsulation in calcium alginate beads for instance, or cationic LNPs coated with chitosan …”

“…In a follow-up study, HLNPs were used to adsorb phospholipase D, allowing repeated use of this expensive enzyme over four cycles of transformation of phospholipids to polar headgroup-modified derivatives. 55 This approach simplifies the use of LNPs in enzyme immobilization; previously enzyme-coated LNPs have been stabilized by encapsulation in calcium alginate beads for instance, 39 or cationic LNPs coated with chitosan. 44 …”