<span style="font-variant: small-caps">D</span>-Xylose Sensing in <i>Saccharomyces cerevisiae</i>: Insights from <span style="font-variant: small-caps">D</span>-Glucose Signaling and Native <span style="font-variant: small-caps">D</span>-Xylose Utilizers
Extension of the substrate range is among one of the metabolic engineering goals for microorganisms used in biotechnological processes because it enables the use of a wide range of raw materials as substrates. One of the most prominent examples is the engineering of baker’s yeast <i>Saccharomy...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-11-01
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| Series: | International Journal of Molecular Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-0067/22/22/12410 |
| Summary: | Extension of the substrate range is among one of the metabolic engineering goals for microorganisms used in biotechnological processes because it enables the use of a wide range of raw materials as substrates. One of the most prominent examples is the engineering of baker’s yeast <i>Saccharomyces cerevisiae</i> for the utilization of <span style="font-variant: small-caps;">d-</span>xylose, a five-carbon sugar found in high abundance in lignocellulosic biomass and a key substrate to achieve good process economy in chemical production from renewable and non-edible plant feedstocks. Despite many excellent engineering strategies that have allowed recombinant <i>S. cerevisiae</i> to ferment <span style="font-variant: small-caps;">d-</span>xylose to ethanol at high yields, the consumption rate of <span style="font-variant: small-caps;">d</span>-xylose is still significantly lower than that of its preferred sugar <span style="font-variant: small-caps;">d</span>-glucose. In mixed <span style="font-variant: small-caps;">d</span>-glucose/<span style="font-variant: small-caps;">d</span>-xylose cultivations, <span style="font-variant: small-caps;">d</span>-xylose is only utilized after <span style="font-variant: small-caps;">d</span>-glucose depletion, which leads to prolonged process times and added costs. Due to this limitation, the response on <span style="font-variant: small-caps;">d</span>-xylose in the native sugar signaling pathways has emerged as a promising next-level engineering target. Here we review the current status of the knowledge of the response of <i>S. cerevisiae</i> signaling pathways to <span style="font-variant: small-caps;">d</span>-xylose. To do this, we first summarize the response of the native sensing and signaling pathways in <i>S. cerevisiae</i> to <span style="font-variant: small-caps;">d</span>-glucose (the preferred sugar of the yeast). Using the <span style="font-variant: small-caps;">d</span>-glucose case as a point of reference, we then proceed to discuss the known signaling response to <span style="font-variant: small-caps;">d</span>-xylose in <i>S. cerevisiae</i> and current attempts of improving the response by signaling engineering using native targets and synthetic (non-native) regulatory circuits. |
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| ISSN: | 1661-6596 1422-0067 |