Abstract
The alkenone producing species Isochrysis galbana has been cultured at different temperatures, nutrient and light levels, to investigate effects of genetic and environmental variation on U (sub 37) (super K') . The experiments show that: (1) the U (sub 37) (super K') -temperature relationship of I. galbana differs significantly from such relationships established for other species, (2) U (sub 37) (super K') values are not significantly influenced by nitrogen limitation, (3) U (sub 37) (super K') values are influenced by phosphate and light limitation equivalent to temperature decreases of about 5-7 degrees C at 16 degrees C. Temperature thus is not the only variable capable of changing alkenone unsaturation and the model that alkenones play a role in membrane fluidity regulation alone, seems too simple. Abstract Copyright (2001) Elsevier, B.V.