The Shiitake Mushroom: What is an example of a trehalose sugar?

December 18, 2025 •

4 min read

The common shiitake mushroom contains trehalose, a unique sugar that allows fungi and other organisms to withstand extreme environmental conditions, from desiccation to freezing. This resilient disaccharide, composed of two glucose molecules, serves as a prime example of a trehalose sugar found widely in nature, often called 'mushroom sugar'.

Quick Summary

Trehalose is a disaccharide sugar, consisting of two glucose units, found naturally in shiitake mushrooms, yeast, insects, and resurrection plants. It functions as both an energy source and a protective molecule, helping organisms survive desiccation, freezing, and heat stress.

Key Points

Shiitake Mushrooms: A common dietary example where trehalose acts as a cellular protectant, enabling dried mushrooms to be rehydrated effectively.
Insects: Many insects use trehalose as their primary blood sugar for energy, particularly for high-energy activities like flying.
Resurrection Plant: This desert plant utilizes trehalose to survive extreme drought, protecting its cells and allowing it to revive when rehydrated.
Stress Tolerance: Trehalose protects organisms from various stresses, including freezing, heat, and desiccation, by stabilizing proteins and cellular membranes.
Food Preservation: In the food industry, trehalose is used to extend the shelf life of foods, prevent discoloration, and improve texture in products like ice cream.
Low Sweetness and Stability: Trehalose is less sweet than sucrose and highly stable under heat and acidic conditions, making it a versatile ingredient.

Trehalose in Fungi: The Shiitake Mushroom

Trehalose is most famously found in fungi, with the shiitake mushroom (Lentinula edodes) being a well-known dietary example. Within these mushrooms, trehalose plays a vital role in protecting cells from environmental stresses. In fact, the presence of this sugar is why dried shiitake mushrooms can be effectively rehydrated, regaining their original shape and texture when soaked in water. Trehalose achieves this by helping to stabilize cell membranes and proteins, preventing damage caused by dehydration. The unique chemical properties of trehalose make it an excellent cryoprotectant and osmoprotectant, vital for the mushroom's survival through its lifecycle.

Other Fungal Examples

Beyond shiitake, trehalose is a critical component in other fungi and microorganisms as well. Baker's yeast (Saccharomyces cerevisiae) is another excellent example, where trehalose accumulation is associated with increased stress resistance. It serves as a stored carbohydrate and helps the yeast survive during long periods of freezing, acting as a protectant for cell viability.

Trehalose in Insects: The Flight Fuel

Insects represent another fascinating class of organisms where trehalose plays a crucial, specialized role. For many insects, trehalose is the primary blood sugar, circulating in the hemolymph (insect blood) where it is readily available for energy, particularly for sustained activities like flight.

Unlike mammals, which primarily use glucose as their circulatory sugar, insects metabolize trehalose. This disaccharide is more stable and provides a more rapid and efficient energy release when cleaved by the enzyme trehalase. One molecule of trehalose yields two molecules of glucose upon hydrolysis, providing a potent energy boost for the high demands of flight. This makes trehalose an optimal energy transport and storage molecule for many insect species, including:

Bees
Butterflies
Grasshoppers
Silkmoths

Trehalose in Plants: The 'Resurrection' Effect

Some plants, particularly those adapted to desert conditions, utilize trehalose to survive extreme drought. The most famous is the resurrection plant (Selaginella lepidophylla). This remarkable plant can withstand complete desiccation, appearing dead and brittle, only to unfurl and turn green again when water becomes available. Trehalose enables this revival by protecting the plant's cellular structures from the damage that would normally occur during severe dehydration. The sugar forms a glassy matrix around cellular components, stabilizing them in the absence of water.

Comparison of Trehalose with Other Sugars

To understand the uniqueness of trehalose, it's helpful to compare its properties with more common sugars like sucrose and maltose. While all are disaccharides, their structures and functions differ significantly.


Feature	Trehalose	Sucrose	Maltose
Chemical Structure	Two α-glucose units with an α-1,1 glycosidic bond.	One glucose and one fructose unit with an α-1,2 bond.	Two α-glucose units with an α-1,4 glycosidic bond.
Reducing Sugar	No, it is a non-reducing sugar.	No, it is a non-reducing sugar.	Yes, it is a reducing sugar.
Stability	Highly stable under heat and acidic conditions.	Less stable under heat and acidic conditions compared to trehalose.	Less stable compared to trehalose.
Sweetness	Approximately 45% the sweetness of sucrose, with a mild, clean taste.	The benchmark for sweetness.	Roughly 30-50% the sweetness of sucrose.
Biological Role	Energy storage, stress protection (cryoprotectant, osmoprotectant).	Energy transport and storage.	Broken down for energy.

Practical Applications of Trehalose

Given its unique properties, trehalose has found applications far beyond its natural biological functions, particularly in the food and biopharmaceutical industries. Its low sweetness and high stability make it an ideal ingredient for a wide range of products. One of its most valuable properties is its ability to inhibit browning reactions (Maillard reaction) and prevent protein denaturation.

Food Preservation

In the food industry, trehalose is used to protect frozen desserts like ice cream from crystal formation, resulting in a smoother, creamier texture. It also helps extend the shelf life of baked goods and prevents discoloration in fruits and vegetables. The commercial production of trehalose, often from starch, has made it a readily available food ingredient for these purposes.

Medical and Pharmaceutical Uses

In medicine, trehalose's cryoprotective properties are leveraged for the preservation of various biological materials, including proteins, cells, and tissues. It is also used as a stabilizer in certain vaccines and other biopharmaceuticals. Research is ongoing into its potential therapeutic uses, such as inducing autophagy to help clear protein aggregates linked to neurodegenerative diseases. For more on trehalose's medical potential, see this study on its applications in the biopharmaceutical industry.(https://pmc.ncbi.nlm.nih.gov/articles/PMC3102588/)

Conclusion

Trehalose is a truly versatile and fascinating sugar, with the shiitake mushroom serving as a simple, illustrative example of its natural occurrence. Far from being a mere sweetener, trehalose's evolutionary role as a protective agent against desiccation, freezing, and other environmental stresses highlights its unique chemical structure. From powering insect flight to resurrecting dormant plants and stabilizing biological materials in laboratory settings, this unassuming disaccharide is a powerful testament to the diverse and complex functions of carbohydrates in the biological world.

Summary of Key Examples and Functions

Shiitake Mushrooms: Trehalose in edible fungi like shiitake helps cells endure dehydration and rehydration, maintaining texture and integrity.
Insects: It serves as the primary, high-energy blood sugar in insects, powering high-demand activities such as flight.
Resurrection Plants: In desert plants like Selaginella, trehalose allows for survival and revival after complete drying by protecting cellular components.
Baker's Yeast: Trehalose accumulation provides resistance to stress conditions like freezing, ensuring the viability of yeast cells.
Food Industry: Commercially, it's used as a preservative and texturizer in frozen foods, baked goods, and more, thanks to its stabilizing properties.

Frequently Asked Questions

Trehalose is found naturally in a wide variety of organisms, including certain bacteria, fungi (like shiitake mushrooms and yeast), insects (like bees and butterflies), and plants (including the 'resurrection plant' Selaginella).

In insects, trehalose serves as the primary energy source in the hemolymph (insect blood), providing the fuel needed for high-energy activities such as flight.

During desiccation (drying), trehalose helps protect organisms by forming a glassy matrix around cellular components, which stabilizes proteins and membranes and prevents damage from extreme water loss.

In the food industry, trehalose is used as a food ingredient for its stabilizing and preservative properties. It can improve the texture of frozen foods, extend the shelf life of baked goods, and prevent fruit and vegetable discoloration.

No, trehalose is significantly less sweet than sucrose (table sugar). It has a mild, clean sweetness that is approximately 45% as sweet as sucrose.

While both trehalose and maltose are disaccharides made of two glucose units, they are structurally different. Trehalose has a highly stable α-1,1 glycosidic bond and is a non-reducing sugar, whereas maltose has an α-1,4 bond and is a reducing sugar.

Yes, humans can digest trehalose. It is broken down into two glucose molecules by the enzyme trehalase in the small intestine and then absorbed. However, a small percentage of the population, particularly Greenlandic Inuit, may have trehalase deficiency.

A well-known example is the Selaginella lepidophylla or 'resurrection plant.' This desert plant can completely dry out and enter a state of dormancy, but the trehalose inside its cells allows it to survive the dehydration and rehydrate to full life when water returns.