Impact of temperature and light intensity on triacylglycerol accumulation in marine microalgae

Triacylglycerol (TAG) productivity of Isochrysis galbana, Nannochloropsis oceanica and Phaeodactylum tricornuturn was compared to study their suitability for biotechnological applications. Photoautotrophic batch cultures grown at 20 C and 50 mu mol photons m(-2) s(-1) showed that N. oceanica had the least TAG content and TAG productivity of the three microalgae. Hence, effects of temperature and light intensity on growth rate and accumulation of TAG were subsequently assessed only in I. galbana and P. tricornuturn by cultivation at 20 and 30 degrees C under 50, 300 and 600-mu mol photons m(-2) s. Although P. tricornutum did not grow at temperatures higher than 20 degrees C, an increase in both TAG content (from 28.37 to 39.53%) and productivity (from 15.58 to 31.39 mg L-1 d(-1)) was observed at the highest irradiance values. We also found that combined effects of temperature and light intensity enhanced TAG content (from 18.59 to 31.71%) and productivity (from 11.76 to 21.67 mg L-1 d(-1)) in I. galbana. (C) 2014 Elsevier Ltd. All rights reserved.