Improving Yeast Strains with Adaptive Lab Evolution for Better Butanol Tolerance

Greg Howard
1st July, 2024

Improving Yeast Strains with Adaptive Lab Evolution for Better Butanol Tolerance

Image Source: Natural Science News, 2024

Key Findings

  • The study by the University of Campinas focused on improving butanol tolerance in two yeast strains, X2180-1B and CAT-1, using adaptive laboratory evolution (ALE)
  • Initially, the CAT-1 strain showed higher butanol tolerance than the X2180-1B strain
  • After ALE, the X2180-1B strain evolved to tolerate and grow in 1% butanol, with the X2180_n100#28 colony showing the highest growth rate
  • The findings suggest that the X2180-1B strain, particularly the X2180_n100#28 colony, could be key for future genetic and evolutionary engineering to optimize yeast for butanol production
The search for alternative biofuels has led to the exploration of butanol as a viable substitute for gasoline. Butanol offers several advantages over ethanol, including higher energy content and better compatibility with existing fuel infrastructure[2]. Although traditionally produced by Clostridium species, the industrial application of Clostridial fermentation is hampered by inherent limitations[3]. Consequently, recent research has focused on using Saccharomyces cerevisiae, a yeast known for its adaptability to industrial conditions and extensive genetic toolkit, as an alternative for butanol production[2][3]. A recent study conducted by the University of Campinas aimed to evaluate the adaptive capacity of two S. cerevisiae strains—X2180-1B and CAT-1—when subjected to adaptive laboratory evolution (ALE) in the presence of butanol[1]. The goal was to enhance the yeast's tolerance to butanol, which could subsequently lead to increased butanol production. The study employed two ALE strategies: successive passages and UV irradiation, using 1% butanol as the selection pressure. The CAT-1 strain is a dominant fuel-ethanol fermentative strain from the Brazilian sugarcane industry, known for its genetic heterogeneity and industrial robustness[4]. Initially, CAT-1 exhibited greater tolerance to butanol compared to the laboratory strain X2180-1B. However, after undergoing ALE, CAT-1 did not show significant improvements in butanol tolerance. On the other hand, the laboratory strain X2180-1B demonstrated remarkable adaptability. Starting from an inability to grow in 1% butanol, it evolved to not only tolerate but also grow in the same condition. This was particularly notable in the isolated colony X2180_n100#28, which exhibited the highest maximum specific growth rate among all isolated colonies. The findings from this study suggest that the X2180-1B strain, especially the X2180_n100#28 colony, holds promise as a model yeast for understanding the mechanisms underlying alcohol tolerance. This could be pivotal for future genetic and evolutionary engineering efforts aimed at optimizing S. cerevisiae for butanol production. Previous studies have shown that wild-type S. cerevisiae strains can produce n-butanol, albeit at low concentrations[3]. For instance, the UFMG-CM-Y267 strain produced about 12.7 mg/L of butanol in a glycine-containing medium. These findings indicate that genetic modification and selection could enhance butanol production in yeast. The current study builds on this by demonstrating that adaptive laboratory evolution can significantly improve butanol tolerance in S. cerevisiae, thereby laying the groundwork for future optimization efforts. The study's use of ALE as a method for improving butanol tolerance is particularly noteworthy. ALE involves subjecting organisms to stressful conditions over successive generations, allowing for the natural selection of traits that confer survival advantages. This approach has been used to study evolutionary changes in various organisms, providing insights into the relationship between phenotypic changes and underlying genotypic alterations[5]. In summary, the research conducted by the University of Campinas highlights the potential of S. cerevisiae as a robust platform for butanol production. By leveraging adaptive laboratory evolution, the study demonstrates that it is possible to enhance butanol tolerance in yeast, a crucial step toward making butanol a commercially viable biofuel. This research not only builds on previous findings but also opens new avenues for optimizing yeast strains for industrial applications.



Main Study

1) Performance of Saccharomyces cerevisiae strains against the application of adaptive laboratory evolution strategies for butanol tolerance.

Published 30th June, 2024

Related Studies

2) Butanol production by Saccharomyces cerevisiae: perspectives, strategies and challenges.

3) Analysis of metabolite profiles of Saccharomyces cerevisiae strains suitable for butanol production.

4) Whole-genome sequencing of the efficient industrial fuel-ethanol fermentative Saccharomyces cerevisiae strain CAT-1.

5) Genome dynamics during experimental evolution.

Related Articles

An unhandled error has occurred. Reload 🗙