The use of adaptive evolution to increase phytase production

Phytate functions as a major storage molecule for phosphorous in grain seeds. The presence phytate in grains is problematic for two main reasons. First, the large negative charge of the molecule causes it to tightly bind cations such as iron, zinc and calcium, rendering them less bioavailable in the diets of animals fed high grain diets. Second, considering that phytate is the primary source of phosphorous in grains, the inability to enzymatically degrade phytate means that a high grain diet is also a phosphorous-deficient one. Phytases are enzymes that possess the ability to hydrolyze phosphate residues from phytate, making phosphorous more bioavailable and reducing the anti-nutrient qualities of phytate. Phytases are added to animal feeds to increase micronutrient bioavailability, to reduce phosphorous in animal waste and to eliminate the need to add phosphate to feed formulations. Many companies have active research programs for the development of improved phytases, however, most of these research programs rely on genetic engineering, resulting in a GMO product. We have used adaptive evolution to develop a non-GMO strain of fungus that secretes 60-fold more phytase than the original input strain.