Volatile analysis of sucrose-grown Saccharomyces cerevisiae

Authors: Shilman, Mikhail; Gee, Wai; Henderson, Thomas

Submitted to: ACS Agricultural Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/13/2024
Publication Date: 9/25/2024
Citation: Shilman, M.M., Gee, W.S., Henderson II, T.D. 2024. Volatile analysis of sucrose-grown Saccharomyces cerevisiae. ACS Agricultural Science and Technology. https://doi.org/10.1021/acsagscitech.4c00073.
DOI: https://doi.org/10.1021/acsagscitech.4c00073

Interpretive Summary: Fruit flies, such as Drosophila melanogaster and suzukii, are a major pest of soft-fleshed fruits. Adult fruit flies are strongly attracted to food odors provided by the microbial fermentation of sugars in fruits to volatile acetic acid and ethanol. In combination with sugar, the yeast Saccharomyces cerevisiae has been used effectively as bait in traps for D. melanogaster and suzukii in the berry production districts of the Central Coast of California. Unfortunately, volatile chemicals produced by yeast-fermented sucrose as the only energy source haven’t been determined. Such volatiles are present in the commercially used Drosophila lures in the field. This study determines volatile molecules produced during sucrose fermentation by yeast, which would be tested in future studies for their ability to attract fruit flies and be used as a synthetic blend in traps.

Technical Abstract: Fruit flies are naturally attracted to fermenting yeast because yeasts are necessary for Drosophila courtship, egg production, and a food source for larval development. Therefore, fermentation-based traps have been used to lure fruit fly pests. Such traps contain sucrose solution as the sole source of carbohydrates for yeast fermentation. However, the volatile organic compounds (VOCs) produced during sucrose fermentation by yeast have yet to be determined. We used SPME-GC/MS analysis and identified VOCs produced by Saccharomyces cerevisiae grown on 50 mM sucrose for 1 hour, 1 day, and 4 days. A total of 101 VOCs were identified, representing acids, alcohols, aldehydes, and ketones. The abundance of VOCs varied, with five major VOCs (2-methylbutanol, 3-methylbutanol, ethanol, 2-phenethyl alcohol, and ethyl octanoate) representing 80% of all volatile abundance. The abundance of some VOCs increases over time, whereas others decrease or do not change over time. Future studies will determine specific VOCs that contribute to attracting fruit flies to sucrose-fermenting yeast.