Stabilization and operational selectivity alteration of Lipozyme 435 by its coating with polyethyleneimine: Comparison of the biocatalyst performance in the synthesis of xylose fatty esters

Microbial Lipases and Their Potential in the Production of Pharmaceutical Building Blocks

“…( II ) Representation of lipases immobilized in a hydrophobic surface crosslinked with an ionic polymer. In the presence of surfactant binding points are also lost, however here it is shown that in contrast to I there is no enzymatic desorption [ 161 , 162 ].…”

“…To solve this, strategies of physical or chemical modification of the hydrophobic derivative have been proposed such as the use of coatings with siloxanes [ 158 ], and other polymers such as dextran aldehyde [ 159 ] or polyethylenimine that can chemically or physically crosslink the immobilized enzymes [ 160 ]: this crosslinking protects the derivative from inactivation caused by desorption, since the enzyme will be part of a composite of higher molecular weight, in which more enzyme-support unions should be broken simultaneously to cause its release when compared to those in the case of the enzyme immobilized without modification ( Figure 8 ). However, the possible gain in stability obtained in the derivative through these modifications is not only inevitably accompanied by an increase in the complexity of the immobilization protocol and the reuse of the support, it also involves changes in the activity or selectivity of the derivative, so the modification process should be optimized under those variables in a particular reaction [ 161 ]. This was evidenced in a recent study, in which the authors improved the stability and catalytic properties of Thermomyces lanuginosus lipase (TLL) adsorbed on a hydrophobic support by using additives that function as cross-linking units, allowing the loss of lipase to be reduced from 40% to <2% of the adsorbed enzyme, with only 0.5% w / w of the corresponding additive, further achieving in the case of CS the increase in catalytic efficiency by two-fold [ 162 ].…”

Enzyme Immobilization and Co-Immobilization: Main Framework, Advances and Some Applications

“…Finally, mono-, di and tri-esters were synthesized when the coated biocatalyst opposite to non-coated biocatalyst was used. This behavior was tentatively associated by the authors to either conformational enzyme modifications induced by polyethyleneimine or to accumulation of acid molecules in the enzyme environment [65]; (ii) ionic interactions established between the carrier, viz. a charged resin and the oppositely charged sites on the enzyme surface (Figure 1b).…”

“…Adsorption and ionic binding are quite simple and low-cost methods, but non-specific. Affinity binding is highly selective, enables one pot purification and immobilization and allows oriented enzyme immobilization, yet it is costly [44,[65][66][67][68][69]. Chemical attachment to the carrier involves covalent binding through amide, carbamate, ether or thio-ether bonds established between groups of suitable residues on the enzyme surface and on the carrier (Figure 1d 1 ) [36,67].…”

“…For instance, hydrogels provide a hydrophilic environment that can enhance enzymatic activity in a reaction medium involving organic solvents, namely when solvent sensitive enzymes are involved (e.g., dioxygenases) [78]. However, the risk of enzyme leakage, particularly in entrapment, is considerable and mass transfer limitations are often referred [36,65,70,79]. Detailed insight on recent achievements and foreseen developments involving enzyme immobilization in hydrogels can be found in a recently published review [80].…”