Long chain alkenes, alkenones and alkenoates produced by the haptophyte alga Chrysotila lamellosa CCMP1307 isolated from a salt marsh

The compositions of long chain alkenes, alkenones and alkenoates in a cultured strain of the haptophyte Chrysotila lamellosa CCMP1307, isolated from a salt marsh, were investigated. The biomarker patterns were distinctive and showed a high proportion of tetraunsaturated alkenones and alkenoates, with a pronounced proportion of C40 alkenones and a lack of C38 methyl and C39 ethyl alkenones. Linear regression of the alkenone unsaturation degree ( U 37 K ) with growth temperature (T) was obtained over the range of possible CCMP1307 growth temperature values (4–20 °C): U 37 K = 0.045 × T (°C) − 1.016, (n = 13, r2 0.96), while the U 37 K ′ values were weakly correlated with T: U 37 K ′ = 0.0035T (°C) + 0.0511 (n = 18, r2 0.70). The U 37 K calibration exhibited a low y-intercept in comparison with that of a Chinese inland lake strain reported previously. The data show significant intraspecific variation in U 37 K for C. lamellosa between strains from different geographic origins. C. lamellosa CCMP1307 reproduced typical U 37 K values observed in C37:4 rich lakes, especially at lower temperature (< 15 °C). In addition, we identified C29:2, C31:1, C31:2 and C31:3 alkenes, and found that the unsaturation degree of C31 alkenes ( U 31 en ), calculated with C31:1 and C31:2 alkenes, might also be a useful index of growth temperature for the haptophyte C. lamellosa.