Evaluation of Lipid Modified Lipase for Interesterification and Hydrolysis Reactions in n-Hexane.

Abstract

Lipase modification by addition of lipid is a simple and effective way to greatly improve enzyme activity for n-hexane based interesterification and hydrolysis reactions. The ranges of modifying lipids and lipases were evaluated, with stearic acid and lipase Saiken 100 (Rhizopus japonicus) investigated in more detail. Enzyme protein recovery and activity were influenced by the quantity of stearic acid addition and the pH of the aqueous preparation phase. Modified lipase protein was characterized using SDS-PAGE electrophoresis. In addition, modified lipase was inunobilized within alginate beads allowing for easy biocatalyst separation and re-use for hydrolysis reactions in n-hexane.

Evaluation of immobilized modified lipase: Aqueous preparation and reaction studies in n‐hexane

“…The solution containing SA had the highest adsorption profile, followed by lipase buffer, which in turn was higher than the lipase water solution (circles). These data support previous studies (8,29) where protein recovery was favored with acidic Tris buffer (5 mmol/L) and by the presence of SA. SA therefore promotes the recovery of protein during ML preparation, which implies that fatty acid and ionic interactions are important for the binding of enzyme and carrier over the range of loading concentrations tested.…”

Selective transesterification of triolein with methanol to methyl oleate and glycerol using alumina loaded with alkali metal salt as a solid-base catalyst

“…Vegetable oils and animal fats usually contain water [15]. To examine the effect of water on the transesterification of triolein with methanol, water was added directly to the reaction solution.…”

“…The effects of reaction variables such as the molar ratio of methanol to triolein on the yields of the reaction products; methyl oleate and glycerol, are examined. Further, the effect of water on the catalytic activity of the catalyst is also investigated, as vegetable oils and animal fats usually contain water [15] and this material may affect the catalytic activity of this system.…”

Interesterification and hydrolysis catalyzed by fatty acid-modified lipases

“…In other words, some of the modified lipases with low interesterification activity contained a significant amount of the active (for hydrolysis) lipase molecule. This suggests that lipase activation for interesterification is associated with the environment or molecular conformation of the lipase [9] and not to purification of the "active" protein [8]. It has been reported that lipases are activated at the oil-water or a hydrophobic interface so as to catalyze lipid hydrolysis [16][17][18][19], which involves a conformational change of the lipase structure [20,21].…”

“…Previously, we reported a fatty acid modification method that improved the transesterification activity of some lipases in organic solvents [8,9]. These lipase-fatty acid complexes exhibited high interesterification activity in nhexane.…”