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dc.contributor.authorNg, Matthewen 14:02:26 (GMT) 14:02:26 (GMT)
dc.description.abstractSupercritical fluids have unique properties which may make them ideal as reaction media for biotransformation or extractive solvents. Supercritical fluids are ideal for reducing diffusivity limitations over conventional fluids. Depending on the polarity of the fluid, a supercritical fluid can be similar to conventional organic solvents, but with few of the environmental drawbacks. The use of supercritical fluids in enzymatic research has the advantage of removing mass transport limitations so that they can act as a suitable solvent. In this study, four permeabilization techniques were compared: control, toluene, supercritical carbon dioxide, and freeze/thaw cycles. The model cell systems studied were Z. mobilis and E. coli. The cells were analyzed for lipid profiles, recovery of proteins and enzymatic activity. The use of supercritical carbon dioxide may not be the most effective of the treatments based on total protein or enzyme recovery since the greatest protein and enzyme recovery was with the freeze/thaw treatment. However, it can be selective in removing cofactors from Z. mobilis enabling sorbitol production and minimizing side reactions. In this application, supercritical carbon dioxide does show an advantage over the freeze/thaw treatment. Aspects of the mechanism of permeabilization were investigated based on the lipid profiles of the cells, scanning electron microscopy (SEM) and atomic force microscopy (AFM). The SEM and AFM show changes of the cell surface morphology which indicate that the treatments affect the cellular surface. The use of supercritical carbon dioxide as a reaction medium was investigated. Minute quantities of sorbitol were produced when Z. mobilis and sugars were placed in a supercritical carbon dioxide environment over a period of 24 hours.en
dc.format.extent1570338 bytes
dc.publisherUniversity of Waterlooen
dc.rightsCopyright: 2001, Ng, Matthew. All rights reserved.en
dc.subjectMechanical Engineeringen
dc.subjectsupercritical carbon dioxideen
dc.subjectzymomonas mobilisen
dc.subjectcell permeabilizationen
dc.subjectescherichia colien
dc.titleCell Permeabilization Using Supercritical Carbon Dioxideen
dc.typeMaster Thesisen
dc.pendingfalseen Engineeringen
uws-etd.degreeMaster of Applied Scienceen

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