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The Effect of Temperature on the Fatty Acid Composition of Tetrahymena pyriformis WH‐14
Author(s) -
CONNER ROBERT L.,
STEWART BARBARA Y.
Publication year - 1976
Publication title -
the journal of protozoology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 0022-3921
DOI - 10.1111/j.1550-7408.1976.tb05269.x
Subject(s) - tetrahymena pyriformis , polyunsaturated fatty acid , glycerophospholipids , palmitoleic acid , degree of unsaturation , tetrahymena , linolenic acid , composition (language) , fatty acid , biochemistry , food science , chemistry , biology , stereochemistry , linoleic acid , organic chemistry , phospholipid , linguistics , philosophy , membrane
SYNOPSIS. A reduction in the growth temperature of Tetrahymena pyriformis strain WH‐14 from 35 C to 15 C resulted in distinct alterations in the fatty acid composition of the glycerophospholipids. The proportion of normal saturated acids declined from 26 to 19%; palmitoleic acid increased by 6%, and the composition of the polyunsaturated fatty acids increased in 18:2 Δ 6,11 (n) and decreased in 18:2 Δ 9,12 (n) and 18:3 Δ 6,9,12 (n). The unsaturation index (the average number of double bonds/100 molecules) did not change with a shift in temperature. Two biosynthetic pathways exist in Tetrahymena for the formation of unsaturated fatty acids. The observed changes in fatty acid composition that accompany a lowering of the environmental temperature can be accounted for by a reduction in the accumulation of products of the fatty acid pathway leading to the formation of γ‐linolenic acid [16:0(n) → 18:0(n) → 18:1 Δ 9 (n) → 18:2 Δ 9,12 (n) → 18:3 Δ 6,9,12 (n)] and an increase in the components of the pathway leading to the formation of 18:2 Δ 6,11 (n) [16:0(n) → 16:1 Δ 9 (n) → 18:1 Δ 11 (n) → 18:2 Δ 6,11 (n)]. The data suggest that the regulatory mechanism in Tetrahymena differs from that found in some bacteria where a simple substitution of unsaturated fatty acids for saturated fatty acids occurs at low culture temperatures.