Polysaccharide Synthases - F and H

Description:

Non-cellulosic polysaccharides, including (1,3;1,4)-β-D-glucans, are key components of the cell walls in cereal grain tissues. These non-cellulosic polysaccharides constitute less than 10% of the overall weight of the grain; however they are important determinants of grain quality. (1,3;1,4)-β-D-glucans are important in the large-scale feed and food processing activities, including brewing, and have attracted renewed interest more recently because of their beneficial effects in human nutrition.

We have identified genes encoding (1,3;1,4)-β-D-glucan synthases that may be modulated in order to increase or decrease the levels of (1,3;1,4)-β-D-glucan synthases in a cell. An increase in the levels and/or activity of (1,3;1,4)-β-D-glucan synthase will result in an increase in (1,3;1,4)-β-D-glucans while a decrease will result in the opposite effect. GM techniques can be used to produce plants with higher or lower levels of (1,3;1,4)-β-D-glucan, depending on the required outcome.

Identification of these genes also allows for the accurate identification of plants with the gene, genes with polymorphisms that may influence the amount of (1,3;1,4)-β-D-glucan produced, and the number of copies of the gene within the plant, thereby enabling the user to use non-GM techniques to produce plants with higher and lower amounts of (1,3;1,4)-β-D-glucan.

Proposed market and value proposition

(1,3;1,4)-β-D-glucans are important in many areas and we have identified the top 4 prospective markets as:

1.       Human nutrition - Increase dietary fibre by increasing the level of (1,3;1,4)-β-D-glucans in the plant.

(1,3;1,4)-β-D-glucans are non-starchy polysaccharides. The properties of these correspond to dietary fibre and thus have important health implications for humans. When included in the diet, the properties of these non-starchy polysaccharides may lead to a decrease in conditions including coronary heart disease, inflammatory bowel disease and various cancers including breast and colo-rectal.

Oats and barley already have relatively high levels of beta-glucans and the principal opportunity would be to produce a high beta glucan wheat so that for example a naturally high beta glucan loaf bread can be baked and sold.

Health statements dependent upon the levels of beta glucans are permitted in a number of jurisdictions including, USA, EU and Australia. Some such statements relate to beta glucans from oats. 

This is the largest prospective market, though one with the greatest barrier to entry.

2.       Monogastric nutrition – Decrease anti-nutritive effects of β-glucan by decreasing the level of β-glucan in the plant.

The presence of non-starchy polysaccharides, of which β-glucans can be a major component, in grain fed to monogastrics can act as a physical barrier to nutrient digestion and absorption as well as changing gut function, resulting in poor nutrient uptake by the animal.  Many producers supplement the animal feed with enzymes to degrade the non-starchy polysaccharides and thereby increase nutrient efficiency. Thus, the decrease of β-glucans in grain fed to monogastric animals would result in increased nutrient efficiency and decreased costs of supplementation.

3.       Beer and malting – decrease the amount of β-glucan in barley to decrease wort and beer viscosity.

Currently, enzymes are added during the brewing process to breakdown β-glucans and thereby increase wort and beer filtration rates. Removal of this step or a decrease in the amount of enzyme added would thus decrease the costs of brewing. 

4.       Biofuels – decrease the levels of β-glucan to increase recoverable sugars.

As with beer and malting, the presence of high levels of β-glucan in mash leads to a highly viscous mash that results in a slow and inefficient filtration and thus lower recoverable sugars. A decrease in the levels of β-glucan in the grain would just result in more efficient filtration and recoverable sugars.

5.       The CSL F and H genes can also be used to produce β-glucans in a recombinant expression system.

B-glucans are extracted from the cell walls of baker’s yeast and cereal grains and used as soluble fibre supplements for human health. When used as a supplement, B-glucans may play a role in reducing blood cholesterol and activating the human immune system.

These patents may be marketed, licensed and/or sold together or separately.

Patent Information:
For Information, Contact:
Kiara Bechta-Metti
The University of Adelaide
Kiara.Bechta-Metti@adelaide.edu.au
Inventors:
Geoffrey Fincher
Rachel Burton
Keywords:
Agriculture
Energy
Food & Ag
Petroleum, Oil & Gas
Renewable Energy