Related Experiment Video
Updated: Jun 21, 2026
08:11
Adaptation at the Extremes of Life: Experimental Evolution with the Extremophile Archaeon Sulfolobus acidocaldarius
Published on: June 14, 2024
Construction of Hansenula polymorpha strains with improved thermotolerance
Olena P Ishchuk1, Andriy Y Voronovsky, Charles A Abbas
1Institute of Cell Biology, NAS of Ukraine, Lviv 79005, Ukraine.
Biotechnology and Bioengineering
|July 4, 2009
Summary
Engineered yeast Hansenula polymorpha shows improved heat tolerance and 5.8-fold higher ethanol production from xylose at 50°C. This enhances potential for high-temperature simultaneous saccharification and fermentation (SSF).
Area of Science:
- Biotechnology
- Microbial Engineering
- Industrial Microbiology
Background:
- Methylotrophic yeast Hansenula polymorpha is a candidate for high-temperature simultaneous saccharification and fermentation (SSF) of xylan-derived xylose.
- Improving thermotolerance and fermentation efficiency is crucial for industrial applications.
Purpose of the Study:
- To enhance high-temperature resistance and fermentation capabilities of H. polymorpha for xylose utilization.
- To engineer strains with deletions in the acid trehalase gene (ATH1) and overexpression of heat-shock protein genes (HSP16, HSP104).
Main Methods:
- Genetic modification of H. polymorpha by deleting the ATH1 gene.
- Overexpression of HSP16 and HSP104 genes in H. polymorpha.
- Assessing thermotolerance via heat-shock treatment.
- Measuring ethanol production from xylose at elevated temperatures (50°C).
Main Results:
- Recombinant strains exhibited up to a 12-fold increase in tolerance to heat-shock treatment.
- Deletion of ATH1 and overexpression of HSP16/HSP104 led to a 5.8-fold improvement in ethanol production from xylose at 50°C.
- Achieved a maximum ethanol concentration of 0.9 g L(-1) from xylose.
Conclusions:
- Engineered H. polymorpha strains demonstrate significantly enhanced thermotolerance and xylose fermentation efficiency.
- These modified strains represent a promising platform for developing improved high-temperature ethanol producers.
- Further metabolic engineering can optimize these strains for industrial-scale pentose fermentation.
More Related Videos
Related Concept Videos
01:21Hyperthermophilic Bacteria
Domain Bacteria includes some unique hyperthermophilic species. They exhibit remarkable adaptations that enable survival in extreme environments.Thermotoga species are rod-shaped, gram-negative, non-sporulating hyperthermophiles that form a sheath-like envelope called a toga. They ferment sugars or starch, producing lactate, acetate, CO₂, and H₂, and can also grow via anaerobic respiration using H₂ and ferric iron. Found in hot springs and hydrothermal vents, over 20% of their genes show strong...
01:29Diversity of Archaea IV
Hyperthermophilic archaea are a group of extremophiles thriving at temperatures above 80°C, often in hydrothermal vents and volcanic soils where conditions surpass the boiling point of water. At such temperatures, proteins, membranes, and DNA in most organisms degrade, but hyperthermophiles have evolved remarkable adaptations to maintain stability and function.Unique Cellular FeaturesHyperthermophilic membranes are composed of a monolayer of biphytanyl tetraether lipids, which resist thermal...
01:27Factors Influencing Microbial Growth: Temperature
Microorganisms display remarkable adaptations, enabling them to thrive in diverse ecological niches across a wide range of temperatures. Temperature profoundly influences microbial growth by affecting enzymatic activity, membrane fluidity, and other cellular processes.Each microorganism operates within a specific temperature range defined by three cardinal points: minimum, optimum, and maximum. Below the minimum temperature, membranes lose fluidity, halting transport processes. Above the...
01:22Bioreactor Controls-III
Strain improvement is a foundational strategy in industrial microbiology aimed at maximizing microbial productivity, particularly because natural isolates typically yield commercially valuable products in very low concentrations. Although optimizing the culture medium and environmental conditions can improve yields, these adjustments are inherently limited by the organism’s genetic potential. As a result, the focus shifts toward genetic modifications to enhance biosynthetic capacity. The...
01:27Diversity of Archaea III
Crenarchaeota, a prominent phylum of Archaea, is remarkable for its ability to thrive in extreme environments characterized by high temperatures and acidity. These microorganisms inhabit sulfuric hot springs, volcanic systems, and submarine hydrothermal vents, where temperatures often exceed 100°C. The unique adaptations of Crenarchaeota not only allow survival under such extreme conditions but also provide insights into the mechanisms of life in primordial Earth-like environments.Morphological...
01:30Diversity of Archaea I
Archaea, a domain of single-celled microorganisms, are classified into five major phyla based on genetic and biochemical characteristics: Euryarchaeota, Crenarchaeota, Thaumarchaeota, Korarchaeota, and Nanoarchaeota. Among these, the phylum Euryarchaeota is notable for its remarkable diversity in morphology, metabolism, and ecological adaptations.Morphological and Metabolic DiversityMembers of Euryarchaeota exhibit a variety of cellular shapes, including rods and cocci. Their metabolic pathways...