In this HPLC and HPAE-PAD molecular plant biology study, researchers identify a gene target that could improve the deconstruction of grass cell walls into component sugars—a major limitation currently faced in biofuel production—so that the grass could be used for biomass much more efficiently and at lower costs. As mentioned in the study, not only do grass and cultivated cereals occupy 20% of terrestrial land but rice straw constitutes 23% of agricultural waste which could be used for biofuel production.
But, cellulose (a polysaccharide and the main structural component of green plant cell walls) is insoluble and keeps the sugars locked up making biofuel production from grasses expensive and challenging. The other fascinating bit I found on the Wikipedia page on cellulose was that it is the most abundant organic polymer on the Earth! (The photo is of a rice leaf cross section.)
In recent months, I have come across many interesting research stories dealing with the challenges of releasing sugars from cellulose for biofuel production, and here are the three that I thought were most interesting:
- Researchers developed a new biofuel production technique does not use expensive enzymes for pre-treating cellulosic biomass thus making it easier to recover the sugars. (Link to story)
- Researchers have engineered an enzyme and developed a process in which production of biofuels from lignocellulosic biomass should be done at temperatures between 65-70 C.
- Scientists find changing the way a plant forms cellulose may lead to more efficient/less expensive biofuel production.
Back to the molecular plant biology study that started this blog post. In the study, titled, Overexpression of a BAHD Acyltransferase, OsAt10, Alters Rice Cell Wall Hydroxycinnamic Acid Content and Sacchariﬁcation, (link to full, free study plus supplemental data), the researchers describe identifying four mutant cell-wall genes followed by the impact of overexpressing one of the mutant cell-wall genes (they label as OsAT10) in rice plants. They used cell wall fractionation and liquid chromatography-mass spectrometry to isolate the cell wall alterations in the mutant genes.
Quantiﬁcation of the hydroxycinnamic acids from the cell walls was carried out on one of our HPLC systems (Thermo Scientific Dionex UltiMate 3000 HPLC system) equipped with one of our UV detection modules. Monosaccharides were analyzed by HPAE-PAD using one of our ion chromatography systems (Thermo Scientific Dionex ICS-3000 system) equipped with one of our electrochemical detectors. One of our carbohydrate columns (Thermo Scientific Dionex CarboPac PA20 column) was used in the HPAE-PAD analysis.
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In their conclusion, the researchers find that: “Biomass from OsAT10-D1 exhibits a 20% to 40% increase in sacchariﬁcation yield depending on the assay. Thus, OsAt10 is an attractive target for improving grass cell wall quality for fuel and animal feed.”
The study was conducted jointly by researchers from University of Oklahoma (U.S.), University of California at Davis, (U.S.), Joint BioEnergy Institute (U.S.), Kyung Hee University (Republic of Korea), Lawrence Berkeley National Laboratory (U.S.), National Renewable Energy Laboratory (U.S.), Zhengzhou Tobacco Research Institute (China), and University of California at Berkeley (U.S.).
You might be interested in viewing these two earlier posts on the use of ion chromatography in biofuel research:
Have you read any similar research studies using our instruments? Do share using the Comments box below; we would like to hear from you!