Improving product release from saccharomyces cerevisiae and kluyveromyces lactis by pretreatment for cell wall weakening and selective product release
Includes bibliographical references (p. 122-129). === Efficient intracellular product release from yeast is required for the recovery of many bioproducts, recombinant or other. Traditionally such product release is achieved by non-selective, energy demanding mechanical disruption. The fine debris re...
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ndltd-netd.ac.za-oai-union.ndltd.org-uct-oai-localhost-11427-118842021-01-25T05:11:31Z Improving product release from saccharomyces cerevisiae and kluyveromyces lactis by pretreatment for cell wall weakening and selective product release Fan, Jia Harrison, STL Bioprocess Engineering Includes bibliographical references (p. 122-129). Efficient intracellular product release from yeast is required for the recovery of many bioproducts, recombinant or other. Traditionally such product release is achieved by non-selective, energy demanding mechanical disruption. The fine debris resulting from mechanical disruption is also challenging in the solid-liquid separation in downstream process. This study investigates the effect of the pretreatment on the energy efficiency of cell disruption, the extent of product release and its selective product release. Saccharomyces cerevisiae and Kluyveromyces lactis were used as the model microorganisms while disruption following pretreatment was achieved on exposure to ultrasound or passing through the high pressure homogenisation (HPH). Pretreatments were selected for their ability to weaken the yeast cell wall, rather than to permeabilise the cell. This allowed product release to be concentrated into the disruption step only, not distributed between the disruption and pretreatments steps. Rapid temperature treatment at 40 to 60CC, pH shock across the range pH 9 to 11 and osmotic pressure between 0.5 MPa and 5 MPa were used as single pretreatment. Combined pretreatments were also considered. These were affected by diluting the yeast suspension into a pre-warmed pH or high osmolarity buffer. On dilution, the temperature was increased rapidly to 40CC, while the pH or osmotic pressure was increased to pH 10 or 1 MPa. 2015-01-10T06:45:30Z 2015-01-10T06:45:30Z 2009 Master Thesis Masters MSc http://hdl.handle.net/11427/11884 eng application/pdf University of Cape Town Faculty of Engineering and the Built Environment Centre for Bioprocess Engineering Research |
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language |
English |
format |
Dissertation |
sources |
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topic |
Bioprocess Engineering |
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Bioprocess Engineering Fan, Jia Improving product release from saccharomyces cerevisiae and kluyveromyces lactis by pretreatment for cell wall weakening and selective product release |
description |
Includes bibliographical references (p. 122-129). === Efficient intracellular product release from yeast is required for the recovery of many bioproducts, recombinant or other. Traditionally such product release is achieved by non-selective, energy demanding mechanical disruption. The fine debris resulting from mechanical disruption is also challenging in the solid-liquid separation in downstream process. This study investigates the effect of the pretreatment on the energy efficiency of cell disruption, the extent of product release and its selective product release. Saccharomyces cerevisiae and Kluyveromyces lactis were used as the model microorganisms while disruption following pretreatment was achieved on exposure to ultrasound or passing through the high pressure homogenisation (HPH). Pretreatments were selected for their ability to weaken the yeast cell wall, rather than to permeabilise the cell. This allowed product release to be concentrated into the disruption step only, not distributed between the disruption and pretreatments steps. Rapid temperature treatment at 40 to 60CC, pH shock across the range pH 9 to 11 and osmotic pressure between 0.5 MPa and 5 MPa were used as single pretreatment. Combined pretreatments were also considered. These were affected by diluting the yeast suspension into a pre-warmed pH or high osmolarity buffer. On dilution, the temperature was increased rapidly to 40CC, while the pH or osmotic pressure was increased to pH 10 or 1 MPa. |
author2 |
Harrison, STL |
author_facet |
Harrison, STL Fan, Jia |
author |
Fan, Jia |
author_sort |
Fan, Jia |
title |
Improving product release from saccharomyces cerevisiae and kluyveromyces lactis by pretreatment for cell wall weakening and selective product release |
title_short |
Improving product release from saccharomyces cerevisiae and kluyveromyces lactis by pretreatment for cell wall weakening and selective product release |
title_full |
Improving product release from saccharomyces cerevisiae and kluyveromyces lactis by pretreatment for cell wall weakening and selective product release |
title_fullStr |
Improving product release from saccharomyces cerevisiae and kluyveromyces lactis by pretreatment for cell wall weakening and selective product release |
title_full_unstemmed |
Improving product release from saccharomyces cerevisiae and kluyveromyces lactis by pretreatment for cell wall weakening and selective product release |
title_sort |
improving product release from saccharomyces cerevisiae and kluyveromyces lactis by pretreatment for cell wall weakening and selective product release |
publisher |
University of Cape Town |
publishDate |
2015 |
url |
http://hdl.handle.net/11427/11884 |
work_keys_str_mv |
AT fanjia improvingproductreleasefromsaccharomycescerevisiaeandkluyveromyceslactisbypretreatmentforcellwallweakeningandselectiveproductrelease |
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1719374288851566592 |