title: Genetic manipulation of outer membrane permeability: generating porous heterogeneous catalyst analogs in Escherichia coli.
abstract: The limited permeability of the E. coli outer membrane can significantly hinder whole-cell biocatalyst performance. In this study, the SARS coronavirus small envelope protein (SCVE) was expressed in E. coli cells previously engineered for periplasmic expression of carbonic anhydrase (CA) activity. This maneuver increased small molecule uptake by the cells, resulting in increased apparent CA activity of the biocatalysts. The enhancements in activity were quantified using methods developed for traditional heterogeneous catalysis. The expression of the SCVE protein was found to significantly reduce the Thiele moduli (ϕ), as well as increase the effectiveness factors (η), effective diffusivities (De), and permeabilities (P) of the biocatalysts. These catalytic improvements translated into superior performance of the biocatalysts for the precipitation of calcium carbonate from solution which is an attractive strategy for long-term sequestration of captured carbon dioxide. Overall, these results demonstrate that synthetic biology approaches can be used to enhance heterogeneous catalysts incorporated into microbial whole-cell scaffolds.
authors.affiliation: Department of Chemical Engineering, Columbia University , New York, New York 10027, United States.
authors.forename: Tushar N
authors.initials: TN
authors.lastname: Patel
authors.forename: Ah-Hyung Alissa
authors.initials: AH
authors.lastname: Park
authors.forename: Scott
authors.initials: S
authors.lastname: Banta
mesh_terms: D002462:Cell Membrane / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D002463:Cell Membrane Permeability / Q000235:genetics*; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D005818:Genetic Engineering / Q000379:methods*; D016062:Porosity; D058615:Synthetic Biology / Q000379:methods*; D014759:Viral Envelope Proteins / Q000235:genetics
chemical_list: D014759:Viral Envelope Proteins
keywords: biocatalysis; carbonic anhydrase; cell diffusivity; permeabilization; thiele modulus; viroporin