2018 Fiscal Year Annual Research Report
Intramolecular isotope analysis of lipids as a novel biological and environmental proxy
| Project/Area Number |
18H01326
|
|---|
| Research Institution | Tokyo Institute of Technology |
|---|
Principal Investigator |
ジルベルト アレキシー 東京工業大学, 理学院, 助教 (20726955)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
中川 麻悠子 東京工業大学, 地球生命研究所, 研究員 (20647664)
|
|---|
| Project Period (FY) |
2018-04-01 – 2021-03-31
|
| Keywords | Isotope / Lipids / Biogeochemistry / Environment / Fatty acids |
|---|
| Outline of Annual Research Achievements |
We first developed a method to measure position-specific isotope composition of lipids using an on-line pyrolysis system. The method gave reproducible results but appeared to be prone to carbon scrambling. In other words, obtaining position-specific isotope composition using on-line pyrolysis appeared to be difficult.
We thus changed slightly our strategy and decided to use Nuclear Magnetic Resonance (NMR) to analyze lipids intramolecular iosotope composition. While NMR requires few 100s mg sample for one analysis, it is not prone to isotope fractionation. Thus, the data obtained from it can be considered as accurate.
In order to be able to isolate sufficient amount of lipids for NMR analysis, we purchased a preparative HPLC, able tp purify 1000s mg of fatty acids methyl esters. Preliminary results on vegetable oil suggest that (i) there is an alternation between odd and even C-atom position 13C/12C ratio in the carbon chain (ii) lipid biosynthesis itself may be prone to isotope fractionation, a fact that was never shown until now.
|
| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
While intramolecular isotope analysis of lipids is challenging, we made great progress to our strategy. The protocol is now in place in the lab and we can potentially analyze lipids from any source, providing we have enough material.
|
| Strategy for Future Research Activity |
The next steps will include cultivation of bacteria (E.coli), yeast (S. cerevisae) in large amounts (ongoing work).
We will also analyze lipids from plants (leaf waxes and free lipids). For that purpose, a collaboration with a research group in China has been started.
This will allow to have a vision of the range of intramolecular isotope variation in living organisms and to start developing models to explain the measurements.
Given the large amount required for analysis, the experiments with different environmental conditions will be more limited than previously thought, but will still be feasible in a reasonable time.
|
Research Products
(7 results)
-
-
[Journal Article] Methane sources and sinks in continental sedimentary systems: New insights from paired clumped isotopologues 13CH3D and 12CH2D22019
Author(s)
T. Giunta, E. D Young, O. Warr, I. Kohl, J. L. Ash, A. Martini, S. O. C. Mundle, D. Rumble, I. Perez-Rodriguez, M. Wasley, D. E. LaRowe, A. Gilbert, B. Sherwood Lollar
-
Journal Title
Geochim. Cosmochim. Acta
Volume: 245
Pages: 327-351
DOI
-
-
-
-
-
