1. Characterization of pectinase-producing Saccharomyces cerevisiae UCDFST 09-448 and its effects on cull peach fermentations.
- Author
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Gutierrez-Cano, Aaliyah, Jones, Bryce, Macario, Jordan, Martin, Sofia, Cardenas, Derrick, Simpson, Hannah, Boundy-Mills, Kyria, and Edwards, Meredith
- Subjects
Saccharomyces cerevisiae ,Fermentation ,Industrially related conditions ,Pectin-rich biomass ,Pectinase ,Saccharomyces cerevisiae ,Fermentation ,Polygalacturonase ,Ethanol ,Hydrogen-Ion Concentration ,Prunus persica ,Temperature ,Pectins ,Osmotic Pressure ,Biomass ,Industrial Microbiology - Abstract
UNLABELLED: Fermentation of pectin-rich biomass by Saccharomyces cerevisiae can produce bioethanol as a fuel replacement to combat carbon dioxide emissions from the combustion of fossil fuels. Saccharomyces cerevisiae UCDFST 09-448 produces its own pectinase enzymes potentially eliminating the need for commercial pectinases during fermentation. This research assessed growth, pectinase activity, and fermentative activity of S. cerevisiae UCDFST 09-448 and compared its performance to an industrial yeast strain, S. cerevisiae XR122N. Saccharomyces cerevisiae UCDFST 09-448s growth was inhibited by osmotic stress (xylose concentrations above 1 M), ethanol concentrations greater than 5% v/v, and temperatures outside of 30°C-37°C. However, S. cerevisiae UCDFST 09-448 was able to consistently grow in an industrial pH range (3-6). It was able to metabolize glucose, sucrose, and fructose but was unable to metabolize arabinose, xylose, and galacturonic acid. The pectinase enzyme produced by S. cerevisiae UCDFST 09-448 was active under typical fermentation conditions (35°C-37°C, pH 5.0). Regardless of S. cerevisiae UCDFST 09-448s limitations when compared to S. cerevisiae XR122N in 15% w/v peach fermentations, S. cerevisiae UCDFST 09-448 was still able to achieve maximum ethanol yields in the absence of commercial pectinases (44.7 ± 3.1 g/L). Under the same conditions, S. cerevisiae XR122N produced 39.5 ± 3.1 g/L ethanol. While S. cerevisiae UCDFST 09-448 may not currently be optimized for industrial fermentations, it is a step toward a consolidated bioprocessing approach to fermentation of pectin-rich biomass. ONE-SENTENCE SUMMARY: Saccharomyces cerevisiae UCDFST 09-448 demonstrates the potential to ferment pectin-rich biomass as part of a consolidated bioprocess, but is sensitive to industrial stressors.
- Published
- 2024