Yeast membrane adaptation during fermentation

Learmonth, Robert P. (2011) Yeast membrane adaptation during fermentation. In: 2nd International Seminar on Chemistry: Chemestry for a Better Future (ISC 2011), 24-25 Nov 2011, Bandung, Indonesia.

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Abstract

Adaptation of yeasts to changing environments experienced during biomass propagation and ethanolic fermentation for biofuel requires rapid modulation of membrane fluidity. We applied fluorescence spectroscopy and microscopy to investigate yeast cell membrane and physiological responses to such changing environments. Our investigations included development and adaptation of methodology to assess membrane fluidity of yeasts, and has shown that membrane fluidity relates to growth phase, cellular physiology and nutrition as well as to membrane lipid and protein composition. We found that membrane responses to glucose depend on particular membrane proteins. Furthermore our studies have shown that rather than the commonly held view of membrane fluidization, heat damage of membranes leads to lower membrane fluidity, likely due to membrane protein denaturation. In addition, we investigated membrane responses to fluidization by high ethanol concentrations. While other studies indicated that higher membrane fluidity or unsaturated fatty acid content correlated with improved ethanol tolerance, we found the opposite, that the fluidizing effects of ethanol were minimized by decreased membrane fluidity, leading to higher ethanol tolerance. The roles of various cellular factors on these adaptive responses will be discussed.


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Item Type: Conference or Workshop Item (Commonwealth Reporting Category E) (Paper)
Refereed: No
Item Status: Live Archive
Additional Information: No evidence of copyright restrictions preventing deposit.
Depositing User: Assoc Prof Robert Learmonth
Faculty / Department / School: Historic - Faculty of Sciences - Department of Biological and Physical Sciences
Date Deposited: 20 Jul 2012 06:37
Last Modified: 20 Jul 2012 06:37
Uncontrolled Keywords: yeast; ethanol; fermentation; membrane; fluidity
Fields of Research (FOR2008): 10 Technology > 1003 Industrial Biotechnology > 100303 Fermentation
06 Biological Sciences > 0601 Biochemistry and Cell Biology > 060110 Receptors and Membrane Biology
06 Biological Sciences > 0601 Biochemistry and Cell Biology > 060199 Biochemistry and Cell Biology not elsewhere classified
Socio-Economic Objective (SEO2008): B Economic Development > 85 Energy > 8505 Renewable Energy > 850599 Renewable Energy not elsewhere classified
B Economic Development > 86 Manufacturing > 8601 Processed Food Products and Beverages (excl. Dairy Products) > 860102 Beverages (excl. Fruit Juices)
URI: http://eprints.usq.edu.au/id/eprint/20567

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