Diter von Wettstein
From Analysis of Mutants to Metabolic and Genetic Engineering
WSU researcher Dr. Diter von Wettstein leads a team working on breeding high-yielding, proanthocyanidin-free barley, which allows breweries to bottle brilliantly clear beer without chill-haze proofing.
Proanthocyanidins (condensed tannins) from the seed coat tissue in the grain are carried through the brewing process into beer where they cause chill-haze. Currently, that haze is removed by chemical treatment to achieve clear beer with the long shelf life desired by consumers. von Wettstein’s identification of the genes and enzymes synthesizing proanthocyanidins in barley led to mutation breeding of “Radiant,” an elite barley variety which lacks these compounds. Brewer interest in this research is increasing as attention is focused on the undesirable use of chemicals for chill haze proofing.
von Wettstein also is researching the unique genes available in barley to produce proanthocyanidins in the leaves of alfalfa, where they are desired to protect cows and sheep from pasture bloat and can improve amino acid uptake.
The 8 billion broiler chickens produced yearly in the United States are fed with genetically-modified corn. Typically, barley feed for poultry is low in nutritional value due to the absence of an intestinal enzyme for efficient de-polymerization of (1,3:1,4)- β-D-glucan. von Wettstein has developed high yielding barleys containing a protein-engineered (1,3;1,4)-β-D-glucanase. Chicken trials show the addition of just 0.02 percent protein-engineered barley/per kg diet added to non-GMO barley provided the same growth rates and quality as chickens fed GMO corn. Thus, this environmentally friendly barley feed additive for non-ruminant animals consisting of grain containing a novel enzyme is needed only at a concentration comparable to the amount of trace minerals in the diet, and can increase non-transgenic barley production many times over in states like Washington where 3 million broilers are produced yearly.
Diter von Wettstein
R.A. Nilan Distinguished Professor
Department of Crop and Soil Sciences
Washington State University
PO Box 646420
Johnson Hall 267
Pullman, WA 99164-6420