An Efficient Strategy for the Production of Epoxidized Oils: Natural Deep Eutectic Solvent‐Based Enzymatic Epoxidation

Abstract

Poor H 2 O 2 -resistance by enzymes is a key bottleneck in the epoxidation process of oil by enzymatic methods. In this study, the stability of three lipases, from Aspergillus oryzae lipase (AOL), Aspergillus fumigatus lipase B (AflB), and marine Janibacter (MAJ1), in the presence of H 2 O 2 was evaluated in different types of natural deep eutectic solvents (NADES). This stability was strengthened significantly in the NADES compared to the buffer. Specifically, AOL retained 84.7% of its initial activity in the presence of choline chloride/sorbitol (1:1 M ratio) and 3 mol L −1 H 2 O 2 after 24 h incubation at 40 C. In addition, the two-phase epoxidation process was optimized with AOL in ChCl/sorbitol to reach up to 96.8% conversion under the optimized conditions (molar ratio of octanoic acid/H 2 O 2 /C=C-bonds = 0.3:1.5:1, enzyme loading of 15 U g −1 of soybean oil, ChCl/sorbitol content of 70.0% of the weight of hydrophilic phase, and reaction temperature of 50 C). Moreover, the lipase dispersed in NADES retained approximately 66% of its initial activity after being used for seven batch cycles. Overall, NADES-based enzymatic epoxidation is a feasible and promising strategy for the synthesis of epoxidized oils.

Enhancing the Thermostability of Engineered Laccases in Aqueous Betaine-Based Natural Deep Eutectic Solvents

“… 12 , 16 These hints led to the possibility to incubate enzymes in DESs as an alternative postsynthesis approach to avoid their thermal inactivation at high temperatures. 17 − 19 …”

“…The applications of DESs as nontoxic solvents have been increased due to their attractive properties including low flammability, low volatility, facile preparation, high solvability, and compatibility with enzymes. , The latter resulted in higher product conversion and enhanced enantioselectivity in a broad range of biocatalytic reactions . More interestingly, the applications of DESs as cosolvents can also prevent enzyme inactivation typically observed in organic solvents. , These hints led to the possibility to incubate enzymes in DESs as an alternative postsynthesis approach to avoid their thermal inactivation at high temperatures. − …”