Temperature dependent growth rate, lipid content and fatty acid composition of the marine cold-water diatom Porosira glacialis

In this study, the northern cold-water marine diatom Porosira glacialis was cultivated in a pilot-scale mass cultivation system at 5 different temperatures (-2 to 12 degrees C), in order to evaluate temperature-dependent growth rate (in vitro Chl alpha), lipid content (Folch's method) and fatty acid (FA) composition (GC-MS) in the exponential growth phase. We found that P. glacialis has a wide temperature range, with maximum growth at 12 degrees C and positive growth even at sub-zero water temperatures. The lipid content was inversely correlated with temperature, peaking at 33.4 +/- 4.0% at 2 degrees C, and was highly desaturated independently of temperature; PUFA content varied from 71.50 +/- 0.88% at 12 degrees C to 82 +/- 0.64% at -2 degrees C. EPA was the main FA at all temperatures (31.0 +/- 0.7-40.4 +/- 1.2% of total FAs).