title: Continuous production of 6-APA in an aqueous two-phase system.
abstract: An aqueous two-phase system of polyethylene glycol (PEG) and potassium phosphate provided a favorable environment for bioconversion of penicillin G to 6-aminopenicillanic acid (6-APA). The recombinant E. coli cells containing penicillin acylase were partitioned in the phosphate-rich bottom phase, and the product 6-APA in the PEG-rich top phase, which protected the enzyme from deactivation for a longer period of time. The continuous production of 6-APA by recycling the bottom phase showed a slight decrease in enzyme activity from initial 80 mM of 6-APA production to 61 mM during the eight days of operation at a space velocity of 0.12 hours-1. This work showed a possibility that the aqueous two-phase whole-cell enzyme bioconversion could serve as an alternative to immobilized cells on solid matrices.
authors.affiliation: Bioprocess Engineering Research Center, Korea Advanced Institute of Science and Technology, Taejon.
authors.forename: H N
authors.initials: HN
authors.lastname: Chang
authors.forename: Y H
authors.initials: YH
authors.lastname: Lee
authors.forename: C Y
authors.initials: CY
authors.lastname: Lee
mesh_terms: D004800:Enzymes, Immobilized / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D010397:Penicillanic Acid / Q000737:chemistry* / Q000031:analogs & derivatives; D010399:Penicillin Amidase / Q000378:metabolism*; D010400:Penicillin G / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D012995:Solubility; D012997:Solvents
chemical_list: D004800:Enzymes, Immobilized; D011994:Recombinant Proteins; D012997:Solvents; D010397:Penicillanic Acid; D010399:Penicillin Amidase; D010400:Penicillin G; C004408:aminopenicillanic acid