CONICET | Buscador de Institutos y Recursos Humanos

A recombinant lipase LipC12 immobilized by covalent immobilization on Immobead 150 (ImLipC12) was tested in synthesis of pentyloleate (molar ratio alcohol:acid=2:1, 40 ̊C, 5 h) and hidrolysis of soybean oil (molar ratio water:oil=10:1, 40 ̊C, 5 h), both in n-heptane. The relative amount of ImLipC12 was up to 15% (w/w) in relation to oleic acid or soybean oil mass. ImLipC12 showed high activity in the esterification of oleic acid with 1-pentanol, with the acid conversion reaching 85% in 5 h. Reaction products were quantified using GC. The hydrolysis of triglycerides reached 64% and the selectivity to diacylglycerides and monoglycerides in the reaction medium was considerably low (1 and 5%, respectively), whereas the yield of free fattyacids was higher than 60%. The soy hidrolysis was not tested solvent-free. To improve selectivity to partial glycerides reaction time was set in 1 h. The hydrolysis of triglycerides reached now 40% and the selectivity of diacylglycerides and monoacylglycerides in the reaction medium increased to 24% and 3%, respectively. The selectivity to mono and diacylglycerides was not significantly increased with the reduction of the reaction time. The yield to fatty acids after 5h was higher than that obtained using the commercial biocatalyst Lipozyme TL IM (32%, under the same conditions). Compared with Lipozyme TLIM, ImLipC12 showed high yield of fatty acids and it would be an interesting biocatalyst. This work shows that ImLipC12 can be used for the synthesis of aliphatic esters with applications in the cosmetics and food industry. ImLipC12 was stable in the reaction medium and was recovered by filtration. Beyond this, ImLipC12 seems to be an attractive biocatalyst for obtaining highvalue mono and diacylglicerides from the hydrolysis of triglycerides if the reaction conditions can be optimized. In addition, the biocatalyst could be recovered and reused in bothapplications.