Covalent immobilization of enzyme on aminated woven poly (lactic acid) via ammonia plasma: evaluation of the optimum immobilization conditions

Abstract

The present study aims to develop an immobilization support from woven poly (lactic acid) (PLA) and establish the optimum immobilization conditions for trypsin. Woven PLA was modified by ammonia-based plasma treatment in order to incorporate amine groups on its surface. X-ray photoelectron spectroscopy analysis showed that the N1s composition of PLA increased significantly, from 0.66% to 5.92%, after ammonia-based plasma processing. Trypsin from porcine pancreas was immobilized onto modified woven PLA by covalent binding after activating PLA with glutaraldehyde (GA). The results indicated that the optimal GA treatment conditions were as follows: pH of 10.0, 2% GA (v/v), and 180 min crosslinking time. In addition, the optimum immobilization conditions were as follows: pH of 8.5, 10% (owf) of trypsin concentration, 30 min, and 25℃. Under the optimum conditions, the amount of immobilized enzyme on woven PLA was 0.28 mg/mg and specific activity was 3.763 U/mg. In addition, the pH and thermal stabilities of the immobilized trypsin were improved. The immobilized trypsin retained approximately 55% of its initial activity after 20 days of storage and exhibited the potential for repetitive use through approximately 15 cycles. GA crosslinking and trypsin immobilization were found to improve the roughness of the PLA surface and increase its hydrophobicity. The data indicate that modified woven PLA, used as an immobilization support, shows suitable properties for use as a biocatalytic material in enzymatic applications.

Influence of Glutaraldehyde Cross-Linking Modes on the Recyclability of Immobilized Lipase B from Candida antarctica for Transesterification of Soy Bean Oil

“…The immobilization period was also evaluated due to its direct influence on the lipase loading and possibly on the enzyme conformation upon immobilization, since different researchers related a maximum activity in a specific period of time with decrease of the enzyme activity after this period eg [ 29 , 30 , 31 , 32 , 33 , 34 ]. Some of the reasons for such behavior are possibly: the change of enzyme conformation and denaturation [ 29 ], the formation of new bonds between enzyme and support [ 35 ], mass transfer problems [ 36 ], extensive aggregation of the support [ 37 ] or due to steric hindrance against immobilized enzymes [ 38 ]. Hence, the amelioration of immobilization time was obtained employing 10 mg of magnetic nanoparticles and 0.083 mol.…”

Effect of enzymatic hydrolysis on developing support of polyamide woven fabric for enzyme immobilization

“…Shaking was performed at 110 rpm using a shaking water bath. 5 After treatment, the activated samples were washed thoroughly with both buffer solution and distilled water several times to remove any unreacted chemicals. 18 Covalent laccase immobilization on enzymatic hydrolyzed polyamide fabric.…”

“…The protein concentration of the free and immobilized enzyme was determined according to the method of Bradford using bovine serum albumin (BSA) as a standard material. 5,[32][33][34] The amount of immobilized enzyme, in terms of protein loading (mg/g), was calculated using the following equation 5,33-35…”

“…Consequently, various methodologies and support materials have been suggested. 1 Many studies have reported the immobilization of a variety of enzymes, such as proteases, 2,3 pectinases, 4 trypsin 5 and laccases, 1,6,7 onto various support materials. The support itself may play on important role in enzyme immobilization by covalent bonding, since its interaction with the enzyme potentially affects enzyme stability and kinetics.…”

“…The support itself may play on important role in enzyme immobilization by covalent bonding, since its interaction with the enzyme potentially affects enzyme stability and kinetics. 5 It may be formed from either natural polymers, such as pulp fiber, 4 chitosan 8 and cellulose nanofibers, 9 or from synthetic polymers, such as PLA (polylactic acid), 5 polyester 10 and polyamide fibers. 2,11,12 Synthetic polymers have advantages as a support material due to their high strength and durability.…”