Advantages of Heterofunctional Octyl Supports: Production of 1,2-Dibutyrin by Specific and Selective Hydrolysis of Tributyrin Catalyzed by Immobilized Lipases

Abstract

Different lipases immobilized on octyl agarose or heterofunctional (glyoxyl or divinylsulfone) octyl supports have been compared in the selective and specific production of 1,2‐dibutyrin by hydrolysis of tributyrin. The addition of cosolvents improved the solubility of the substrate thus improving the accumulation of 1,2‐dibutyrin. The form B of the lipase from Candida antarctica (CALB) was selected considering reaction both enzyme activity and reaction yields produced by this biocatalyst. Using this enzyme, the highest dibutyrin yield using 100 mM of tributyrin (over 80 %) was obtained using a medium containing 50 % of cosolvent. However, the use of higher tributyrin concentrations required increasing the concentration of cosolvent in order to increase the soluble fraction of substrate. Under these conditions, the enzyme is released to the medium if it is just physically adsorbed on the support. For this reason, the octyl‐CALB biocatalyst is unsuitable for this reaction. Using octyl‐glyoxyl‐CALB in the presence of 75 % cosolvent to facilitate substrate solubility, a conversion yield of 70 % of dibutyrin could be achieved using 1 M of tributyrin as substrate. Using 500 mM tributyrin, the yield under these conditions increased to 80 %. The biocatalyst could be reused for several cycles without any detrimental effect on its performance.

Immobilization on octyl‐agarose beads and some catalytic features of commercial preparations of lipase a from Candida antarctica (Novocor ADL): Comparison with immobilized lipase B from Candida antarctica

“…Thus, the stability of the different enzymes is very different using different organic cosolvents, and the most stable enzyme depends on the organic solvent. The stabilizing effects of the coating of octyl‐lipase with PEI is much lower using CALA than that reported using other enzymes, perhaps because in this study, we are mainly comparing preparations having small enzyme loading where physical enzyme crosslinking is more difficult …”

“…The stabilizing effects of the coating of octyl-lipase with PEI is much lower using CALA than that reported using other enzymes, perhaps because in this study, we are mainly comparing preparations having small enzyme loading where physical enzyme crosslinking is more difficult. 66,67 Activity of the different enzyme biocatalysts vs. different substrates Table 1 shows the specific activities of the different immobilized lipase preparations vs. pNPB, triacetin, and both isomers of methyl mandelate. From the table, the most relevant fact is that CALB is far more active vs. triacetin and methyl mandelate than CALA, by 100 fold, while it is less active (2.5 fold) vs. pNPB.…”

“…42,43 The further coating of these biocatalysts with polyethylenimine (PEI) has been reported to prevent one of the main problems of this immobilization protocol: the enzyme release under drastic conditions (high temperatures and organic cosolvents) 54,63 or when used in reactions involving compounds with detergent features (fatty acids, partial glycerides, and even di or monoacetin). [64][65][66] The physical intermolecular crosslinking with PEI reduces this enzyme leakage, 67,68 and it is a step in some coimmobilization strategies. 69 Finally, the loading of the support with the enzyme may be another key factor to ensure that the lipase performance is really derived from the intrinsic properties of the lipases.…”

Enzyme‐Decorated Covalent Organic Frameworks as Nanoporous Platforms for Heterogeneous Biocatalysis

“…Reported for the first time in 1916, this method has grown significantly over the past decades allowing for the economic viability of the use of several enzymes in industrial processes, causing a great economic and scientific impact. The immobilization of enzymes on a heterogeneous substrate promotes a convenient handling and a facile separation of the biocatalyst from the reaction medium . Additionally, it often enhances enzyme stability towards denaturation by autolysis, decomposition by organic solvents or by heat, as well as boosting the enzyme activity …”

“…[29,30] Reported for the first time in 1916, [31] this methodhas grown significantly over the past decades allowing for the economicv iability of the use of several enzymes in industrial processes, causing ag reat economic and scientific impact.T he immobilization of enzymes on ah eterogeneous substrate promotes ac onvenient handling and af acile separation of the biocatalyst from the reaction medium. [32] Additionally,i to ften enhances enzyme stabilityt owards denaturation by autolysis, decomposition by organic solvents or by heat, as well as boosting the enzyme activity. [33] There are several materials that are suitable for enzyme immobilization, yet one of the most commercially successful catalysts is Novozyme 435 [CAL-B immobilized on Lewatit VP OC 1600 poly (methyl methacrylate-co-divinylbenzene)].A mong all the possible materials for enzyme immobilization, porous structures like porous silica, [34,35] zeolitesa nd metal-organic frameworks (MOFs) [36][37][38] have been gaining popularity due to their unique characteristics, notably their high surfacea rea and porosity.…”