1: Enzyme Microb Technol. 2000 Apr 1;26(7):516-529. Related Articles, Links
A process for high yield and scaleable recovery of high purity
eicosapentaenoic acid esters from microalgae and fish oil.
Belarbi EH, Molina E, Chisti Y.
Department of Chemical Engineering, University of Almeria,
E-04071, Almeria, Spain
A low expense process is developed for recovering esterified
eicosapentaenoic acid (EPA) from microalgae and fish oil. Over 70% of
the EPA content in the esterified crude extract of microalgae were
recovered at purities exceeding 90%. The recovery scheme utilizes
either wet or freeze-dried algal biomass. The process consists of only
three main steps: 1) simultaneous extraction and transesterification
of the algal biomass; 2) argentated silica gel column chromatography
of the crude extract; and 3) removal of pigments by a second column
chromatographic step. Argentated silica gel chromatography recovered
about 70% of the EPA ester present in the crude fatty ester mixture of
fish oil, but at a reduced purity ( approximately 83% pure) compared
to the microalgal derived EPA. The optimal loading of the fatty ester
mixture on the chromatographic support was about 3% (w/w) but loadings
up to 4% did not affect the resolution significantly. The process was
scaled up by a factor of nearly 320 by increasing the diameter of the
chromatography columns. The elution velocity remained constant.
Compared to the green alga Monodus subterraneus, the diatom
Phaeodactylum tricornutum had important advantages as a potential
commercial producer of EPA. For a microalgal EPA process to be
competitive with fish oil derived EPA, P. tricornutum biomass (2.5%
w/w EPA) needs to be obtained at less than $4/kg. If the EPA content
in the alga are increased to 3.5%, the biomass may command a somewhat
higher price. The quality of microalgal EPA compares favorably with
that of the fish oil product. Compared to free fatty acid, EPA ester
is more stable in storage. Shelf-life is extended by storing in
hexane. The silver contamination in the final purified EPA was
negligibly small (<210 ppb).