We are partnering with Genesis Organics (GO) and Idaho Potato Products (IPP) to convert low-value potatoes into starch and protein for use in consumer products. Our project aims to find optimal extraction and pretreatment methods to maximize the yield and purity of protein and starch compounds from Ez chip, Russet, and Gogu Valley potatoes. Preliminary data showed that using the SiccaDania method (gentle fractioning with water for efficient processing) for starch-focused trials resulted in starch yields of 12%, 11.9%, 3.5% for EZ Chip, Russet, and Gogu Valley potatoes, respectively. Ammonium sulfate precipitation used to extract proteins following the methods of Waglay et al. gave protein yields of Ez Chip (1.02%), Gogu (1.00%), then Russet (0.7% ). Applying a pulsed electric field before extraction potentially leads to an increase in starch yield by 4% and purity of starch by 8%. Additionally, the use of an antifoaming agent from IPP increases fluid recovery after cheesecloth filtration and the yield of starchy solids. This research will determine a favorable combination of pretreatment and isolation methods to maximize starch and protein extraction. This will create new enterprises and high-paying economic jobs as it opens up the door for potato upcycling and potentially other related food groups. Future research will deal with adding Dimethyl Ether and Hydrothermal Liquefaction, as well as Ion Exchange and Size Exclusion Chromatography extraction, into our pretreatment combinations.

Protein modifications are crucial to how proteins work, allowing for more diversity in the functioning of proteins. SPINDLY (SPY) is a novel plant protein that catalyzes the transfer of O-fucose from GDP-fucose to other proteins, modifying them. It is part of the protein O-fucosyltransferase (POFUT) family, but is unique in that it is the first nucleocytoplasmic-localized POFUT discovered and contains a tetratricopeptide repeat (TPR) domain that is critical for protein-protein interactions and substrate selection. SPY plays a crucial role in regulating plant growth by interacting with DELLA proteins, which suppress the phytohormone gibberellin that promotes plant growth. Furthermore, SPY has also been shown to affect a plant’s response to stresses in its environment, such as diseases and droughts. By learning more about SPY and how it chooses which proteins to modify, we could create crops that are more resilient to its environment. However, the mechanism by which SPY interacts with other proteins and how these interactions drive substrate selection remains largely unknown. We hypothesize that the full-length TPR domain, containing 11 repeats, is critical for proper protein glycosylation and substrate selection through critical protein-protein interactions. We created an E. coli specific plasmid that can produce full-length SPY from Arabidopsis thaliana and aim to determine how this complete TPR domain affects individual and global O-fucosylation compared to our model construct that only contains three TPR repeats. Through this study we hope to gain a deeper understanding of the substrate scope of SPY and how the TPR domain controls SPY’s function.