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

Abstract

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 (U37K) with growth temperature (T) was obtained over the range of possible CCMP1307 growth temperature values (4–20°C): U37K=0.045×T (°C)−1.016, (n=13, r2 0.96), while the U37K′ values were weakly correlated with T: U37K′=0.0035T (°C)+0.0511 (n=18, r2 0.70). The U37K 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 U37K for C. lamellosa between strains from different geographic origins. C. lamellosa CCMP1307 reproduced typical U37K 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 (U31en), calculated with C31:1 and C31:2 alkenes, might also be a useful index of growth temperature for the haptophyte C. lamellosa.