Rational synthetic combination genetic devices boosting high temperature ethanol fermentation

Area of Science:

• Synthetic Biology
• Biotechnology
• Microbial Fermentation

Background:

• Industrial yeast (Saccharomyces cerevisiae) growth and production are limited by heat and oxidative stress.
• Existing methods for stress mitigation in yeast are insufficient for high-temperature fermentation.

Purpose of the Study:

• To develop a novel synthetic biology strategy to enhance yeast viability and production at high temperatures.
• To synergistically alleviate both heat and oxidative stress in S. cerevisiae through genetic engineering.

Main Methods:

• Constructed and screened heat shock protein (HSP) and superoxide dismutase (SOD) genetic devices from extremophiles.
• Rationally combined HSP and SOD genetic devices to create a synergistic stress alleviation system.
• Introduced the combined genetic device into laboratory and industrial S. cerevisiae strains for fermentation.

Main Results:

• A combined genetic device (FBA1p-sod-MB4-FBA1p-shsp-HB8) significantly enhanced thermotolerance by 250% and cell density by 55% at 42°C compared to single-device strains.
• Ethanol yields increased by 20.6% in lab strains and 26.3% in industrial strains under high-temperature fermentation.
• Synergistic defense against both heat and oxidative stress is crucial for improving yeast thermotolerance and production.

Conclusions:

• The developed synthetic biology approach effectively enhances yeast thermotolerance and fermentation performance.
• Synergistic alleviation of multiple stresses is a necessary strategy for optimizing industrial yeast applications.
• This study provides a promising platform for engineering robust yeast strains for high-temperature bioprocesses.