Ultrasound-assisted <i>in-situ</i> transesterification of wet <i>Aurantiochytrium</i> sp. KRS 101 using potassium carbonate

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>A new <I>in-situ</I> transesterification method was developed for wet biomass: K<SUB>2</SUB>CO<SUB>3</SUB> was used as an alkaline catalyst and, <I>Aurantiochytrium</I> sp. KRS 101 as oleaginous DHA-producing microalgae. It was found that the presence of water greatly impaired the overall efficiency even with the powerful catalyst that had worked surpassingly well with dry biomass, and thus a mechanical aid like ultrasonication was needed to make advantage of full potential of the alkaline catalyst. The total fatty acid ethyl ester (FAEE) recovery yield of 94.6% was achieved with sonication at 100 g/L of biomass (40% moisture), 3% of K<SUB>2</SUB>CO<SUB>3</SUB>, 70 °C and 30 min. All these suggest that the ultrasound assisted <I>in-situ</I> transesterification can offer a feasible means for FAEE recovery and it was so by way of overcoming the physical limitation of mass transfer caused the presence of water and providing effective contacts between reactants.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>In-situ</I> transesterification was successfully conducted on wet <I>Aurantiochytrium</I> sp. </LI> <LI> Potassium carbonate was used as a potent alkaline catalyst for the process. </LI> <LI> Ethanol as an alcohol could suppress saponification by alkaline catalyst. </LI> <LI> Water-rendering mass transfer limitation was overcome by ultrasonication. </LI> </UL> </P>