Abstract
Recent wildfires near vineyards in the Pacific United States have caused devastating financial losses due to smoke taint in wine. When wine grapes (Vitis vinifera) are exposed to wildfire smoke, their berries absorb volatile phenols derived from the lignin of burning plant material. Volatile phenols are released during the winemaking process giving the finished wine an unpleasant, smokey, and ashy taste known as smoke taint. Bacteria are capable of undergoing a wide variety of metabolic processes and therefore present great potential for bioremediation applications in many industries. In this study, we identify two strains of the same species that colonize the grape phyllosphere and are able to degrade guaiacol, a main volatile phenol responsible for smoke taint in wine. We identify the suite of genes that enable guaiacol degradation in Gordonia alkanivorans via RNAseq of cells growing on guaiacol as a sole carbon source. Additionally, we knockout guaA, a cytochrome P450 gene involved in the conversion of guaiacol to catechol; ΔguaA cells cannot catabolize guaiacol in vitro, providing evidence that GuaA is necessary for this process. Furthermore, we analyze the microbiome of berries and leaves exposed to smoke in the vineyard to investigate the impact of smoke on the grape microbial community. We found smoke has a significant but small effect on the microbial community, leading to an enrichment of several genera belonging to the Bacilli class. Collectively, this research shows that studying microbes and their enzymes has the potential to identify novel tools for alleviating smoke taint.
| Original language | English |
|---|---|
| Article number | e0331854 |
| Journal | PLoS ONE |
| Volume | 20 |
| Issue number | 10 October |
| DOIs | |
| State | Published - Oct 2025 |
Funding
We thank the California Association of Winegrape Growers (CAWG) and the USDA-ARS for their financial support (U.S. Department of Agriculture 2030-21210-003-000D). We thank the Washington State Grape and Wine Research program and the USDA ARS for their financial support in the Collins lab (U.S. Department of Agriculture NACA agreement 58-2072-0-033). Additionally, this research was supported in part by the U.S. Department of Energy (DOE), Office of Biological and Environmental Research (BER), as part of Secure Biosystems Design Science Focus Area “Persistence Control of Engineered Functions in Complex Soil Microbiomes” . The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Grapevine cuttings used in the G. alkanivorans isolation work were provided by Foundation Plant Services, University of California, Davis. We thank Andrew Wilson for sharing plasmid vector pJE382 and for his advice. Thank you to the Coleman-Derr lab members for their camaraderie and critical feedback during this study. Additionally, this work was authored in part by Oak Ridge National Laboratory, which is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725. Grapevine cuttings used in the G. alkanivorans isolation work were provided by Foundation Plant Services, University of California, Davis. We thank Andrew Wilson for sharing plasmid vector pJE382 and for his advice. Thank you to the Coleman-Derr lab members for their camaraderie and critical feedback during this study. Additionally, this work was authored in part by Oak Ridge National Laboratory, which is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725. Funding: We thank the California Association of Winegrape Growers (CAWG) and the USDA-ARS for their financial support (U.S. Department of Agriculture 2030-21210-003-000D). We thank the Washington State Grape and Wine Research program and the USDA ARS for their financial support in the Collins lab (U.S. Department of Agriculture NACA agreement 58-2072-0-033). Additionally, this research was supported in part by the U.S. Department of Energy (DOE), Office of Biological and Environmental Research (BER), as part of Secure Biosystems Design Science Focus Area “Persistence Control of Engineered Functions in Complex Soil Microbiomes” . The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.