A study on lipid production of the mixotrophic microalgae Phaeodactylum tricornutum on various carbon sources

Abstract

This study is aimed to investigate the potential use of various carbon sources (glucose, starch, and acetate sodium) for culturing Phaeodactylum tricornutum with higher microalgae oil production in mixotrophic batch cultures. Results showed P. tricornutumcould grow mixotrophically with those organic substrate in a tested range from 0.5 to 5.0 g/l. Glucose and acetate sodium exerted significant promotion on growth of P. tricornutum, while starch did not exhibit this enhancement. The presence of carbon sources in medium could significantly increase the lipid content, especially with glucose. The maximum lipid productivities in mixotrophic cultures with glucose, starch and acetate in medium were 0.053, 0.023 and 0.020 g/l·day, respectively. These values were respectively 4.6-, 2.0-, and 1.7-fold of those obtained in the corresponding photoautotrophic control cultures. For the composition of fatty acids in microalgae oil, there was no significant sensitivity to the variation of the organic carbon sources. The data in this study suggests that P. tricomutum could provide high lipid productivity combined of high oil content and biomass in mixotrophic culture, which offers a promise to be one of the sources of biodiesel. Key words: Lipid productivity, mixotrophic growth, organic carbon sources,Phaeodactylum tricornutum.