Optimized lipase-catalyzed synthesis of adipate ester in a solvent-free system

Abstract

Immobilized Candida antarctica lipase-catalyzed esterification of adipic acid and oleyl alcohol was investigated in a solvent-free system (SFS). Optimum conditions for adipate ester synthesis in a stirred-tank reactor were determined by the response surface methodology (RSM) approach with respect to important reaction parameters including time, temperature, agitation speed, and amount of enzyme. A high conversion yield was achieved using low enzyme amounts of 2.5% w/w at 60 degrees C, reaction time of 438 min, and agitation speed of 500 rpm. The good correlation between predicted value (96.0%) and actual value (95.5%) implies that the model derived from RSM allows better understanding of the effect of important reaction parameters on the lipase-catalyzed synthesis of adipate ester in an organic solvent-free system. Higher volumetric productivity compared to a solvent-based system was also offered by SFS. The results demonstrate that the solvent-free system is efficient for enzymatic synthesis of adipate ester.

Modelling and optimization ofCandida rugosananobioconjugates catalysed synthesis of methyl oleate by response surface methodology

“…The F-MWCNTs allowed for a robust setting for the CRL enzyme linkage [32,44] and improved the hydrophobicity of the microenvironment. [45,46] Nonetheless, the concentration of the formed ester declined at temperatures exceeding 50 C, which was probably caused by the partial inactivation of the CRLMWCNTs. This outcome was somewhat anticipated as the reaction temperature (T > 50 C) had exceeded the optimal temperature of the enzyme.…”

“…Higher reaction temperatures tend to promote propensity of enzyme inactivation, due to conformational changes in the enzyme tertiary structure. [45,46] The study found that by increasing the reaction temperature up to 56 C, higher yields of methyl oleate were possible, albeit by also increasing the reaction time. From an economic point of view, it is more desirable for the esterification process to be executed at a much lower reaction temperature, because less energy is required to operate the large bioreactors.…”

Response surface methodological approach for optimizing production of geranyl propionate catalysed by carbon nanotubes nanobioconjugates

“…[18] It is pertinent to highlight that the presence of excess alcohol molecules in an enzyme-catalysed esterification reaction is predisposed to promote distortion of the essential water layer from the enzyme molecules. [16] Effect of temperature and solvent log P Figure 4 illustrates the effect of varying temperature and solvent log P on the esterification production of geranyl propionate at constant conditions of 6 h and a geraniol:propionic acid molar ratio of 3:1. The highest conversion of geranyl propionate of 46.39% was obtained at 52 C in solvent log P » 3.0.…”

“…[9] In fact, the complexity of the enzyme-catalysed reactions can be enhanced by the sensitivity of the enzyme structure to variables, such as temperature, reaction time, substrate molar ratio and activator or inhibitor concentrations. [9,16] This is the reason why research studies often resort to utilizing a statistical tool known as response surface methodology (RSM). [17] This method uses multiple variables to establish optimum conditions under predetermined reaction preferences, such as high product yield at the lowest cost and/or with the least number of experiments.…”

Synthesis and Characterization of Phenolic Lipids

“…Since the choice of organic solvents based on minimization of acyl migration may conlict with maximization of transesteriication, acyl migration is usually minimized by reducing reaction times [85]. With increasing concern for the environment, synthesis of PL in solvent-free systems [86][87][88] and ionic liquids systems [89] has been extensively studied. The enzymatic synthesis of vanillyl-PUFA esters from ish oil and vanillyl alcohol in acetone solvent medium was studied by [10].…”