Background: Eutectic solvents are a mixture of two compounds which possess a lower
melting temperature than the parent compounds, using quaternary ammonium salts, such as choline
chloride and betaine hydrochloride and organic acids, polyols and amides as hydrogen bond donors.
These solvents can be an alternative as non-aqueous media for enzymatic reactions, mainly using lipases.
Objective: The objective of this work is to evaluate enzymatic activity and stability of commercial lipases,
immobilized or at free form (Thermomyces lanuginosus: Lipozyme TL IM, iTL and Lipolase
100 L, fTL; Candida antarctica: Novozym 435, iCALB; Novozym 735, iCALA and Novozym CALB
L, fCALB); and a phospholipase (Lecitase Ultra), in the presence of eutectic solvents (choline chloride
ChCl:urea, ChCl:glycerol, betaine hydrochloride (BeHCl):urea and BeHCl: glycerol.
Methods: Initially, lipases were maintained for 2 hours in solutions of choline and betaine-based
eutectic solvents (1 to 20% m/m) at 25ºC compared with water for relative enzymatic activity. Using
the solvent that best promoted lipase activity, some parameters were evaluated such as the molar ratio
between quaternary ammonium salts and urea, stocking temperature and kinetics.
Results and Conclusion: These eutectic solvents enable, mainly with immobilized lipases, 25 to 125
times more activity than water at 25ºC and 2h, and even after 24h, lipase iTLL was still 40 times more
active in the presence of ChCl:Urea 1:3. Lipase iCALB showed great thermostability 47 times higher
at 55ºC, almost double relative activity at 25ºC in the presence of BetHCl:Urea 1:4.