Through the use of surface-displayed horseradish peroxidase, this work explores the enzymatic catalysis of both bioRAFT and bioATRP to prompt polymer synthesis on the surface of S. cerevisiae cells, with bioATRP outperforming bioRAFT polymerization.

In this work an enzymatic method for the synthesis of alkyl levulinates from α-angelica lactone has been reported for the first time. Lipase B from Candida antarctica was immobilized via interfacial activation on the surface of a hybrid support, consisting of commercially available multi-walled carbon nanotubes (MWCNTs) and polytetrafluoroethylene (PTFE). Among the biocatalysts with various contents of PTFE in the support, the CALB/MWCNT–PTFE (0.10 wt%) biocatalyst with 22.5 wt% CALB loading was determined as the most active one in the model synthesis of the n-butyl levulinate in toluene. n-Butyl levulinate was obtained quantitively after 120 min of the reaction under the selected reaction conditions (2-fold molar excess of n-butanol, 0.150 g of biocatalyst per 1 mmol of α-angelica lactone, 20 °C). The yield of n-butyl levulinate was found to be higher than that in the presence of accurate amounts of sulfuric acid or Novozyme-435. Additionally, the unique stability of the developed biocatalyst was demonstrated over 6 reaction cycles at 20 °C. The biocatalyst remained stable over 3 reaction cycles at 60 °C as well. The essence of the proposed approach lies in the possibility to overcome the equilibrium limitations occurring in the conventional Fisher esterification. The activity of the elaborated hybrid biocatalyst in the reactions non-specific for lipases is a clear proof of the versatility of the novel system.

This study presents a highly efficient method of a synthesis of n-butyl acrylate via esterification of acrylic acid and n-butanol in the presence of supported ionic liquid phase (SILP) biocatalyst consisting of the lipase B from Candida antarctica (CALB) and multi-walled carbon nanotubes (MWCNTs) modified by D-glucose-based ionic liquids. Favorable reaction conditions (acrylic acid: n-butanol molar ratio 1:2, cyclohexane as a solvent, biocatalyst 0.150 g per 1 mmol of acrylic acid, temperature 25 °C) allowed the achievement of a 99% yield of n-butyl acrylate in 24 h. Screening of various ionic liquids showed that the most promising result was obtained if N-(6-deoxy-1-O-methoxy-α-D-glucopyranosyl)-N,N,N-trimethylammonium bis-(trifluoromethylsulfonyl)imide ([N(CH₃)₃GlcOCH₃][N(Tf)₂]) was selected in order to modify the outer surface of MWCNTs. The final SILP biocatalyst–CNTs-[N(CH₃)₃GlcOCH₃][N(Tf)₂]-CALB contained 1.8 wt.% of IL and 4.2 wt.% of CALB. Application of the SILP biocatalyst led to the enhanced activity of CALB in comparison with the biocatalyst prepared via physical adsorption of CALB onto MWCNTs (CNTs-CALB), as well as with commercially available Novozyme 435. Thus, the crucial role of IL in the stabilization of biocatalysts was clearly demonstrated. In addition, a significant stability of the developed biocatalytic system was confirmed (three runs with a yield of ester over 90%).