Biofuels in Perspective

ability to reduce
flocculation (% of
cells flocculated)
A B C
a b c
+ +++ -
(0) (91)
(0)
Figure 8.16 Photographs of flocculating yeast during agitation (A, B and C) and after sedimentation for
5 s (a, b, and c). Panels: A and a: S. cerevisiae MT8-1/pWIFSProROL; panels B and b: S. cerevisiae MT8-
1/pWIFLProROL; panels C and c: S. cerevisiae MT8-1/pWI3 (control). Ability of different constructs to trigger
flocculation is indicated by +++ (full flocculation), + (slight flocculation), or – (no flocculation). Values
in parentheses represent percentage of cells that settled after 1 min. (From Ref. 75, with permission of
American Society for Microbiology.)
ME content (wt%)
100
80
60
40
20
Methanol
addition
0
0 24 48 72
Reaction time (h)
Figure 8.17 Time course of methanolysis reaction using yeast whole cells. ME content in reaction mixture
is plotted against reaction time. ME content was defined as ME weight as a percentage of the total oil phase
weight of the reaction mixture. Arrows show times of addition of 0.35 g methanol. Symbols: open circle: S.
cerevisiae MT8-1/pWIFSProROL; open square: MT8-1/pWIFLProROL; open triangle: MT8-1/pWI3 (control).
(From Ref. 75, with permission of American Society for Microbiology.)