Polyethylenimine: a very useful ionic polymer in the design of immobilized enzyme biocatalysts

Lipase A from Candida antarctica (CALA, commercialized as Novocor ADL) was immobilized on octyl‐agarose, which is a very useful support for lipase immobilization, and coated with polyethylenimine to improve the stability. The performance was compared to that of the form B of the enzyme (CALB) immobilized on the same support, as both enzymes are among the most popular ones used in biocatalysis. CALA immobilization produced a significant increase in enzyme activity vs. p‐nitrophenyl butyrate (pNPB) (by a factor of seven), and the coating with PEI did not have a significant effect on enzyme activity. CALB reduced its activity slightly after enzyme immobilization. Octyl‐CALA was less stable than octyl‐CALB at pH 9 and more stable at pH 5 and, more clearly, at pH 7. PEI coating only increased octyl‐CALA stability at pH 9. In organic solvents, CALB had much better stability in methanol and was similarly stable in acetonitrile or dioxane. In these systems, the PEI coating of octyl‐CALA permitted some stabilization. While octyl‐CALA was more active vs. pNPB, octyl‐CALB was much more active vs. mandelic esters or triacetin. Thus, depending on the specific reaction and the conditions, CALA or CALB may offer different advantages and drawbacks. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 35: e2735, 2019

Section: Coating Of Immobilized Cala With Peimentioning

confidence: 82%

Section: Resultsmentioning

confidence: 99%

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

Arana-Peña

Lokha

Fernández‐Lafuente

2018

“…Due to this necessity, many researchers have studied how to couple the immobilization process and the overcome of other enzyme uses challenge, such as enzyme stability, activity (mainly under harsh conditions), selectivity or specificity, resistance to inhibitor, and even the protein purity . In this way, immobilization became a critical step in the design of enzyme biocatalysts and it must be considered along other enzyme stabilization strategies …”

Section: Introductionmentioning

confidence: 99%

Preparation of immobilized/stabilized biocatalysts of β‐glucosidases from different sources: Importance of the support active groups and the immobilization protocol

Andrades

Graebin

Ayub

et al. 2019

Self Cite

β‐Glucosidases from two different commercial preparations, Pectinex Ultra SP‐L and Celluclast® 1.5L, were immobilized on divinylsulfone (DVS) supports at pH 5.0, 7.0, 9.0, and 10. In addition, the biocatalysts were also immobilized in agarose beads activated by glyoxyl, and epoxide as reagent groups. The best immobilization results were observed using higher pH values on DVS‐agarose, and for Celluclast® 1.5L, good results were also obtained using the glyoxil‐agarose immobilization. The biocatalyst obtained using Pectinex Ultra SP‐L showed the highest thermal stability, at 65°C, and an operational stability of 67% of activity after 10 reuses cycles when immobilized on DVS‐agarose immobilized at pH 10 and blocked with ethylenediamine. The β‐glucosidase from Celluclast® 1.5L produced best results when immobilized on DVS‐agarose immobilized at pH 9 and blocked with glycine, reaching 7.76‐fold higher thermal stability compared to its free form and maintaining 76% of its activity after 10 successive cycles. The new biocatalysts obtained by these protocols showed reduction of glucose inhibition of enzymes, demonstrating the influence of immobilization protocols, pH, and blocking agent.

“…A simplest strategy is the use of an aminated polymer, like polyethylenimine . However, a preferred alternative is to use a feeder protein, rich in amino groups, as this prevents the generation of ionic environments around the enzyme .…”

Section: Introductionmentioning

confidence: 99%

1,3‐Regiospecific ethanolysis of soybean oil catalyzed by crosslinked porcine pancreas lipase aggregates

Ramos

Miranda

Giordano

et al. 2018

Self Cite

The preparation of crosslinked aggregates of pancreatic porcine lipase (PPL-CLEA) was systematically studied, evaluating the influence of three precipitants and two crosslinking agents, as well as the use of soy protein as an alternative feeder protein on the catalytic properties and stability of the immobilized PPL. Standard CLEAs showed a global yield (CLEA' observed activity/offered total activity) of less than 4%, whereas with the addition of soy protein (PPL:soy protein mass ratio of 1:3) the global yield was approximately fivefold higher. The CLEA of PPL prepared with soy protein as feeder (PPL:soy protein mass ratio of 1:3) and glutaraldehyde as crosslinking reagent (10 μmol of aldehyde groups/mg of total protein) was more active mainly because of the reduced enzyme leaching in the washing step. This CLEA, named PPL-SOY-CLEA, had an immobilization yield around 60% and an expressed activity around 40%. In the ethanolysis of soybean oil, the PPL-SOY-CLEA yielded maximum fatty acid ethyl ester (FAEE) concentration around 12-fold higher than that achieved using soluble PPL (34 h reaction at 30°C, 300 rpm stirring, soybean oil/ethanol molar ratio of 1:5) with an enzyme load around 2-fold lower (very likely due to free enzyme inactivation). The operational stability of the PPL-SOY-CLEA in the ethanolysis of soybean oil in a vortex flow type reactor showed that FAEE yield was higher than 50% during ten reaction cycles of 24 h. This reactor configuration may be an attractive alternative to the conventional stirred reactors for biotransformations in industrial plants using carrier-free biocatalysts. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:910-920, 2018.