As we were conducting applied research towards a real world application, an industrial issue that was affecting millions, we took into account cost effectiveness, scalability, sustainability, and environmental effects.

From our list of possible solution's, we chose the last one; to genetically engineer a Saccharomyces cerevisiae yeast cell to produce and secrete a highly effective form of the starch degrading enzyme amylase. Both yeast and amylase are found in abundance in nature, making our solution environmentally safe. Because the yeast cells will continue to reproduce in the water system and break down starches, this solution is also long-term, sustainable, and cost effective.

The amylase would break the bonds in the starch molecules, and the resultant sugars would be metabolized by the yeast cell.

By removing the starch molecules from the water system, we would be effectively eliminating the food and energy source for the problematic, butyric-acid producing bacteria.

Why S.cerevisae?

The butyric acid levels become problematic when the system goes anaerobic, as it triggers the butyric acid pathway. Our organism would have to be able to survive and thrive in both anaerobic and aerobic conditions, thus yeast provided the perfect organism.

Why amylase?

Alpha amylase is a form of the enzyme that has the capability to hydrolyse the α bonds connecting the monosaccharides in the starch molecules. Unlike beta amylase, which breaks bonds at the ends of starch molecules, alpha amylase can break bonds on both the ends and middle of the starch molecule. This increases the effectiveness of the enzyme. We used an alpha amylase gene from Bacillus amyloliquefaciens, a type of bacteria that naturally produces and secretes alpha amylase. Alpha amylase can also act on any substrate, making it versatile and suited for the large scale conditions of the industrial water system.

This approach is unique, previously the only industrial uses of amylase were for production of high fructose corn syrup and ethanol production from grains. This is the first time an amylase has been applied as a solution in a large-scale industrial construction manufacturing water system.