The Effect Of Temperature On The Fatty Acid Composition Of Tetrahymena Pyriformis WH-14
Journal Of Protozoology
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 Δ6,11(n) and decreased in 18:2 Δ9,12(n) and 18:3 Δ6,9,12(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) [RIGHTWARDS ARROW] 18:0(n) [RIGHTWARDS ARROW] 18:1 Δ9(n) [RIGHTWARDS ARROW] 18:2 Δ9,12(n) [RIGHTWARDS ARROW] 18:3 Δ6,9,12(n)] and an increase in the components of the pathway leading to the formation of 18:2 Δ6,11(n) [16:0(n) [RIGHTWARDS ARROW] 16:1 Δ9(n) [RIGHTWARDS ARROW] 18:1 Δ11(n) [RIGHTWARDS ARROW] 18:2 Δ6,11(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.
R. L. Conner and Barbara Y. Stewart.
"The Effect Of Temperature On The Fatty Acid Composition Of Tetrahymena Pyriformis WH-14".
Journal Of Protozoology.