One John Marshall Drive
Robert C. Byrd Biotechnology Science Center, Suite 314
Huntington, WV 25755
Engineering Unique Alginates
Alginate is composed of two different monosaccharides (sugars) mannuronic acid and guluronic acid. The ratios of these two sugars affects the properties of the polymer. On general, a calcium alginate gel with a higher M:G ration will be fluid and flexible, while that with a higher G:M ration will be less fluid and stiffer. The M:G ratio of seaweed alginate is dictated by the species in the range of 70%M/30%G, to 55-60%G/45-40%M.
Producing alginate in bacteria provides that opportunity to use bioengineering to create unique alginates not found in seaweed. Progenesis is using genetic techniques to modify the enzymes involved in alginate production to allow synthesis of polymers with a much broader range of M:G ratios than found in seaweed. We anticipate that gels formed by these polymers will have enhanced favorable properties for a variety applications such as tissue engineering.
Bacterial alginate also has an additional chemical modification not found in seaweed alginate. The mannuronic acid sugar can have acetyl group bonded to one or two carbon atoms. Typically, 25-30% of the M sugars are acetylation. The addition of the acetyl groups allows the alginate to absorb more water. Bacterial alginate with 25% of M sugars acetylated absorbs 10-15X more water than seaweed alginate with the same M:G ratio. The use of genetic modification of the expression/activity of the acetylation enzymes in Pseudomonas will allow production of alginate polymers having different degrees of water absorption important for application such as wound healing and personal care products.