title: Effect of Ethanol Stress on Fermentation Performance ofSaccharomyces cerevisiaeCells Immobilized onNypa fruticansLeaf Sheath Pieces.
abstract: The yeast cells ofSaccharomyces cerevisiaeimmobilized onNypa fruticansleaf sheath pieces were tested for ethanol tolerance (0, 23.7, 47.4, 71.0 and 94.7 g/L). Increase in the initial ethanol concentration from 23.7 to 94.7 g/L decreased the average growth rate and concentration of ethanol produced by the immobilized yeast by 5.2 and 4.1 times, respectively. However, in the medium with initial ethanol concentration of 94.7 g/L, the average growth rate, glucose uptake rate and ethanol formation rate of the immobilized yeast were 3.7, 2.5 and 3.5 times, respectively, higher than those of the free yeast. The ethanol stress inhibited ethanol formation bySaccharomyces cerevisiaecells and the yeast responded to the stress by changing the fatty acid composition of cellular membrane. The adsorption of yeast cells onNypa fruticansleaf sheath pieces of the growth medium increased the saturated fatty acid (C16:0 and C18:0) mass fraction in the cellular membrane and that improved alcoholic fermentation performance of the immobilized yeast.
authors.affiliation: Department of Food Technology, Ho Chi Minh City University of Technology, 268 Ly Thuong Kiet Street, District 10, 70000 Ho Chi Minh City, Vietnam.
authors.forename: Hoang Phong
authors.initials: HP
authors.lastname: Nguyen
authors.affiliation: Department of Food Technology, Ho Chi Minh City University of Technology, 268 Ly Thuong Kiet Street, District 10, 70000 Ho Chi Minh City, Vietnam.
authors.forename: Hoang
authors.initials: H
authors.lastname: Du Le
authors.affiliation: Department of Food Technology, Ho Chi Minh City University of Technology, 268 Ly Thuong Kiet Street, District 10, 70000 Ho Chi Minh City, Vietnam.
authors.forename: Van Viet
authors.initials: VV
authors.lastname: Man Le
keywords: Nypa fruticans; Saccharomyces cerevisiae; ethanol stress; fatty acids; immobilized yeast