Cell wall sugars
We can use enzymes to breakdown plant biomass to release sugars for fermentation. In plants the sugars are locked into the cell walls in ways we currently do not fully understand, preventing effective digestion by enzymes. If we can understand better how the plant sugars are arranged in the cell walls, we can select plants, and match them with the most appropriate enzymes, for more effective biofuel production.
Aims and objectives
- Develop rapid technologies to study the detailof cell wall sugar content in biomass and the enzymes that release sugars
- Improve understanding of the plant genes that control cell wall sugar composition
- Discover enzymes that can release sugars from currently indigestible cell wall components
- Understand how some cell wall sugar structures inhibit effective digestion by enzymes
Key resources and technologies
- Cell wall sugar (polysaccharide) analysis,metabolomics, proteomics and bioinformatics
- Discovery of genes controlling plant cell wall polysaccharide synthesis
- Polysaccharidehydrolase enzyme discovery
- Industrial partners with biofuel and bioinformatics expertise, and unique enzyme resources
- University of Cambridge
Associated programme members
- Newcastle University
- Novozymes A/G
Case study – Plant sugars provide clues to sustainable bioenergy production
With the help of the model plant Arabidopsis, a team of BBSRC-funded plant scientists at the University of Cambridge has been able to manipulate the levels of the polysaccharide glucomannan in the plant cell wall. Their findings were published recently in The Plant Journal.
By producing Arabidopsis 'knock out' mutants the team showed that three enzymes within the cellulose synthase-like (CSL) family, CSLA2, CSLA3 and CSLA9, are responsible for the production of all detectable glucomannan in stems.
"This is the first demonstration in plants that the CslA gene subfamily is responsible for glucomannan synthesis," says Dr Paul Dupree. "Importantly, we have shown that the quantity of glucomannan can be increased or decreased in the stem with no visible detrimental effects on plant development or cell wall strength".
In contrast, the team also demonstrated that changing glucomannan levels had a clear effect on seed development.
"Both under- and over-expression of CSLAs during embryogenesis can lead to embryo death," says Dupree.
Being able to increase glucomannan specifically in harvestable plant organs, such as the stem, may be a good target for bioenergy crops where higher proportions of enzyme- accessible fermentable sugars, such as those in glucomannan, would be advantageous.