title: Studies of penicillin g acylase immobilization using highly porous cellulose-based polymeric membrane.
abstract: The different ionic molecules/compounds were used as a ligand for the immobilization of penicillin G acylase on the highly porous cellulose-based polymeric membrane having buffer flux 1,746 LMH (L m(-2) h(-1)) at 0.5 bar pressure. The immobilized enzyme activity around 250 U(App) was obtained with the ligand such as proline, tryptophan, casein acid hydrolysate, and brilliant green. Comparatively, proline showed less IMY% (percentage immobilization yield--58) but higher RTA% (percentage of activity retention--71) and specific activity (145 U(App) g(-1)). However, the crosslinked preparation of brilliant green obtained using glutaraldehyde showed 82 +/- 2.7% immobilized enzyme activity after the completion of successive five cycles. In comparison with the free enzyme, the enzyme immobilized on the brilliant green coupled membrane showed around 2.4-fold increase in K (m) value (47.4 mM) as well as similar optimum pH (7.2) and temperature (40 degrees C). The immobilized enzyme retained almost 50% activity after 107 days and 50 cycles of operation. Almost 50% decrease in buffer flux after enzyme immobilization was observed. At the end of the 30 cycles, flux pattern shows around 38% decrease in buffer flux however, after 16 cycles of operation flux moves closer towards the steady state.
authors.affiliation: Chemical Engineering Division, National Chemical Laboratory, Pune 411008, India. hv.adikane@ncl.res.in
authors.forename: H V
authors.initials: HV
authors.lastname: Adikane
authors.forename: D M
authors.initials: DM
authors.lastname: Thakar
mesh_terms: D002482:Cellulose / Q000737:chemistry; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology; D008567:Membranes, Artificial; D010399:Penicillin Amidase / Q000737:chemistry / Q000378:metabolism*; D016062:Porosity; D000644:Quaternary Ammonium Compounds / Q000737:chemistry
chemical_list: D004800:Enzymes, Immobilized; D008567:Membranes, Artificial; D000644:Quaternary Ammonium Compounds; D002482:Cellulose; D010399:Penicillin Amidase; C006798:brilliant green