초록
<P><B>Abstract</B></P> <P>Mixotrophic cultures of <I>Phaeodactylum tricornutum</I> were carried out in bubble columns using fructose and glycerol in indoor fed-batch and semi-continuous modes. In the fed-batch cultures, different nutrient-addition strategies, combined with stepwise increments in the light intensity, were assayed. It was found that glycerol promoted significantly higher biomass productivity than fructose. A glycerol-induced photoinhibition that arrested the growth of <I>P. tricornutun</I> was also observed. As this was considered a limitation as regards transferring the fed-batch mode to outdoor conditions, this information was used to culture <I>P. tricornutum</I> in semi-continuous mode. Similar glycerol-induced photoinhibition was not observed in these cultures, even at highest dilution rates. Although the highest biomass (1.5gL<SUP>−1</SUP> d<SUP>−1</SUP>) and EPA (40mgL<SUP>−1</SUP> d<SUP>−1</SUP>) productivities found in the semi-continuous cultures were lower than those obtained photoautotrophically in outdoor photobioreactors, the findings showed that semi-continuous mode was an excellent candidate for transferring mixotrophic culture to an outdoor setting.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Fructose prevents photoinhibition during mixotrophic growth of <I>P. tricornutum.</I> </LI> <LI> Glycerol induces photoinhibition during mixotrophic growth of <I>P. tricornutum.</I> </LI> <LI> Glycerol promotes higher biomass productivity than fructose in fed-batch cultures. </LI> <LI> Semi-continuous cultures lead to higher biomass productivities than fed-batch. </LI> </UL> </P>