Antifungal activity of a fatty ammonium chloride amylose inclusion complex against Fusarium sambucinum; control of dry rot on multiple potato varieties

Authors: Hay, William; Fanta, George; Rich, Joseph; Schisler, David; Selling, Gordon

Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/28/2018
Publication Date: 9/14/2018
Citation: Hay, W.T., Fanta, G.F., Rich, J.O., Schisler, D.A., Selling, G.W. 2018. Antifungal activity of a fatty ammonium chloride amylose inclusion complex against Fusarium sambucinum; control of dry rot on multiple potato varieties. American Journal of Potato Research. 96(1):79-85. https://doi.org/10.1007/s12230-018-9683-8.
DOI: https://doi.org/10.1007/s12230-018-9683-8

Interpretive Summary: A new class of antifungal agents has been developed which will increase potato yields resulting in a reduction in cost for consumers. The new technology kills the fungus which causes potato dry rot disease. This fungus can reduce potato yields by 25% post-harvest. Our antifungal agent, patent pending, is made from corn starch and a vegetable oil derivative which are combined at temperatures above the boiling point of water. At these conditions a starch complex is formed – the starch wraps around the vegetable oil derivative. In repeated testing, this starch complex was found to be effective at preventing the growth of the highly destructive potato pathogen Fusarium sambucinum (causing potato dry rot). This fungus harms the US and global food supply. This manuscript outlines the use of our novel starch complex produced from corn, and demonstrates the dramatic reduction in fungal damage on protected potatoes. The starch complexes are produced from low cost farm grown feed stocks using an economical process. The technology can be rapidly adopted for industrial scale production. The technology will provide value to all producers and consumers in the corn and potato value chain.

Technical Abstract: The cationic amylose-hexadecylammonium chloride inclusion complex (Hex-Am) was found to be an effective antifungal treatment for Fusarium sambucinum (Fückel), a causal agent of potato dry rot. The Hex-Am treatment was effective against F. sambucinum in vitro and in situ, with an effective 50% inhibitory concentration of 400 µg/ml; active component concentration of 20 µg/ml. The amylose complex alone, and blended with polyvinyl alcohol (PVOH), was effective in controlling dry rot in five varieties of potatoes with up to a 99% reduction in damage to the potato tubers. The amylose complex showed no apparent signs of phytotoxicity, with wound periderm reforming within one week of storage at 15°C and 90% RH. The Hex-Am treatments form an effective antimicrobial film at the wound site, significantly inhibiting fungal damage to the wounded tubers.