- Trehalose is a naturally occurring disaccharide composed of two glucose molecules linked by an α,α-(1→1) glycosidic bond. Its molecular formula is C₁₂H₂₂O₁₁, the same as other common disaccharides, but the unique linkage makes trehalose non-reducing and exceptionally stable compared to sucrose, maltose, or lactose.
- First discovered in fungi and named after “trehala,” a sugar-rich secretion from weevils that feed on tamarisk trees, trehalose has since been found across a wide range of organisms including bacteria, fungi, algae, insects, and plants.
- One of the defining features of trehalose is its remarkable stability and protective properties. The non-reducing nature of the α,α-(1→1) bond prevents trehalose from undergoing rapid hydrolysis or participating in unwanted chemical reactions such as the Maillard reaction. This stability allows trehalose to act as a stress protectant in many organisms. In fungi, bacteria, and insects, trehalose functions as an energy reserve and as a protective molecule against environmental stressors such as desiccation, heat, cold, and oxidative damage. During dehydration or freezing, trehalose can replace water molecules by forming hydrogen bonds with proteins and lipid membranes, preserving their structure and function — a property known as anhydrobiosis. This adaptation is vital in organisms like tardigrades, brine shrimp, and certain yeast species, which can survive extreme conditions due to trehalose accumulation.
- In metabolism, trehalose serves as a carbohydrate storage form and a circulating sugar. In insects, for example, trehalose is the principal blood sugar, providing a readily mobilizable energy source for flight and other activities. In microorganisms, trehalose synthesis and degradation are tightly regulated by enzymatic pathways such as trehalose-6-phosphate synthase/phosphatase and trehalase, ensuring its dual role in energy supply and stress protection. In plants, trehalose and its phosphorylated derivatives are also involved in signaling pathways that regulate growth, development, and stress responses.
- From an industrial and biomedical perspective, trehalose has gained attention for its wide range of applications. It is used in food preservation due to its ability to stabilize proteins, lipids, and other biomolecules, thereby extending shelf life and maintaining flavor and texture. In pharmaceuticals and biotechnology, trehalose is employed to stabilize vaccines, antibodies, and enzymes during storage and lyophilization. Its protective properties also make it valuable in cosmetics, where it helps retain skin moisture and protect against oxidative damage. Additionally, trehalose has been studied for its potential therapeutic effects in neurodegenerative diseases such as Alzheimer’s, Parkinson’s, and Huntington’s, as it may promote autophagy and reduce protein aggregation.
