Suitability of Soxhlet Extraction to Quantify Microalgal Fatty Acids as Determined by Comparison with In Situ Transesterification
Name
11745_2011_Article_3624.pdf
Size
572.21 KB
Format
Adobe PDF
Checksum (MD5)
4d722915cd5ca1b4b9f4c6826bbf3762
Author(s)
MacDougall, Karen M.
Melanson, Jeremy E.
McGinn, Patrick J.
McNichol, Jesse Christopher
Date Issued
November 2011
Journal
Lipids
Publisher
Springer-Verlag
Citation
McNichol, Jesse, Karen M. MacDougall, Jeremy E. Melanson, and Patrick J. McGinn. “Suitability of Soxhlet Extraction to Quantify Microalgal Fatty Acids as Determined by Comparison with In Situ Transesterification.” Lipids 47, no. 2 (November 6, 2011): 195–207.
Version
Author's final manuscript
Abstract
To assess Soxhlet extraction as a method for quantifying fatty acids (FA) of microalgae, crude lipid, FA content from Soxhlet extracts and FA content from in situ transesterification (ISTE) were compared. In most cases, gravimetric lipid content was considerably greater (up to sevenfold) than the FA content of the crude lipid extract. FA content from Soxhlet lipid extraction and ISTE were similar in 12/18 samples, whereas in 6/18 samples, total FA content from Soxhlet extraction was less than the ISTE procedure. Re-extraction of residual biomass from Soxhlet extraction with ISTE liberated a quantity of FA equivalent to this discrepancy. Employing acid hydrolysis before Soxhlet extraction yielded FA content roughly equivalent to ISTE, indicating that acidic conditions of ISTE are responsible for this observed greater recovery of FA. While crude lipid derived from Soxhlet extraction was not a useful proxy for FA content for the species tested, it is effective in most strains at extracting total saponifiable lipid. Lipid class analysis showed the source of FA was primarily polar lipids in most samples (12/18 lipid extracts contained <5% TAG), even in cases where total FA content was high (>15%). This investigation confirms the usefulness of ISTE, reveals limitations of gravimetric methods for projecting biodiesel potential of microalgae, and reinforces the need for intelligent screening using both FA and lipid class analysis.
MIT Department
Massachusetts Institute of Technology. Department of Biology
Woods Hole Oceanographic Institution
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1007/s11745-011-3624-3
