The tedious preparation procedures and difficulty in free structure formation and recycling have restricted the widespread application of existing enzyme immobilization strategies. Here, we report ...

A Versatile Approach for Enzyme Immobilization Using Chemically Modified 3D-Printed Scaffolds

Immobilization of β-galactosidase in glutaraldehyde-chitosan and its application to the synthesis of lactulose using cheese whey as feedstock

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.

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

Recent progress in the development of immobilized penicillin G acylase for chemical and industrial applications: A mini‐review

β-Galactosidase from Kluyveromyces lactis: Characterization, production, immobilization and applications - A review.

Penicillin G acylase (PGA) was isolated from Providencia rettgeri PX04 (PrPGApx04) and utilized for the kinetically controlled synthesis of β-lactam antibiotics. Site-directed mutagenesis was performed to increase the process efficiency. Molecular docking was carried out to speculate the key mutant positions corresponding with synthetic activity, which resulted in the achievement of an efficient mutant, βF24G. It yielded higher conversions than the wild-type enzyme in the synthesis of amoxicillin (95 versus 17.2%) and cefadroxil (95.4 versus 43.2%). The reaction time for achieving the maximum conversion decreased from 14 to 16 h to 2-2.5 h. Furthermore, the secondary hydrolysis of produced antibiotics was hardly observed. Kinetic analysis showed that the (kcat/Km)AD value for the activated acyl donor D-hydroxyphenylglycine methyl ester (D-HPGME) increased up to 41 times. In contrast, the (kcat/Km)Ps values for the products amoxicillin and cefadroxil decreased 6.5 and 21 times, respectively. Consequently, the α value (kcat/Km)Ps/(kcat/Km)AD, which reflected the relative hydrolytic specificity of PGA for produced antibiotics with respect to the activated acyl donor, were only 0.028 and 0.043, respectively. The extremely low hydrolytic activity for the products of the βF24G mutant enabled greater product accumulation to occur during synthesis, which made it a promising enzyme for industrial applications.

Song Qin

Papers

Efficient synthesis of β-lactam antibiotics with very low product hydrolysis by a mutant Providencia rettgeri penicillin G acylase.