title: Column flow reactor using acetohydroxyacid synthase I from Escherichia coli as catalyst in continuous synthesis of R-phenylacetyl carbinol.
abstract: We tested the possibility of utilizing acetohydroxyacid synthase I (AHAS I) from Escherichia coli in a continuous flow reactor for production of R-phenylacetyl carbinol (R-PAC). We constructed a fusion of the large, catalytic subunit of AHAS I with a cellulose binding domain (CBD). This allowed purification of the enzyme and its immobilization on cellulose in a single step. After immobilization, AHAS I is fully active and can be used as a catalyst in an R-PAC production unit, operating either in batch or continuous mode. We propose a simplified mechanistic model that can predict the product output of the AHAS I-catalyzed reaction. This model should be useful for optimization and scaling up of a R-PAC production unit, as demonstrated by a column flow reactor.
authors.affiliation: Department of Biotechnology Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
authors.forename: Stanislav
authors.initials: S
authors.lastname: Engel
authors.forename: Maria
authors.initials: M
authors.lastname: Vyazmensky
authors.forename: Dvora
authors.initials: D
authors.lastname: Berkovich
authors.forename: Ze'ev
authors.initials: Z
authors.lastname: Barak
authors.forename: Jose
authors.initials: J
authors.lastname: Merchuk
authors.forename: David M
authors.initials: DM
authors.lastname: Chipman
mesh_terms: D000095:Acetolactate Synthase / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D000096:Acetone / Q000031:analogs & derivatives* / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology*; D002384:Catalysis; D002482:Cellulose / Q000737:chemistry; D004800:Enzymes, Immobilized / Q000096:biosynthesis; D004926:Escherichia coli / Q000201:enzymology*; D017434:Protein Structure, Tertiary
chemical_list: D004800:Enzymes, Immobilized; D000096:Acetone; C035293:1-hydroxy-1-phenyl-2-propanone; D002482:Cellulose; D000095:Acetolactate Synthase