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

Abstract

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