Fraunhofer Institute for Molecular Biology and Applied Ecology IME
Structural diversity and biological functions
Isoprenoids are a diverse group of compounds that includes terpenes, steroids, carotenoids, and storage lipids, among others. With over 40,000 known compounds, isoprenoids constitute the largest class of plant secondary metabolites. Their structure is derived from the C5 building block, isoprene. The linking and modification of these units by functional groups, as well as their cyclization, result in the molecules' high diversity.
Terpenoids play a key role in a plant's interaction with its environment. They provide protection against biotic and abiotic stressors, such as defending against potential predators or unwanted competitors. Additionally, they serve as pigments for plants and attract pollinators, ultimately facilitating dispersal of fruits and seeds.
Industrial relevance
Their range of industrial applications is just as diverse as their functions in nature. Large-scale industrial production of various goods, including tires, seals, mattresses, shoe soles, and condoms, uses compounds with a high molecular weight (C > 25,000), such as natural rubber. Low-molecular-weight structures, such as mono-, di-, sesqui-, and triterpenoids, have a wide range of industrial uses, including flavorings, fragrances, vitamins, and ingredients in cosmetics, food, and pharmaceuticals.
Our strategies for sustainable production
Depending on the type of compound and its intended use, various strategies can be employed to meet the ever-growing demand for economically important terpenoids. One traditional strategy is harvesting plants to extract these important metabolites, but this method faces various challenges. For instance, their composition and quantity can fluctuate based on environmental conditions, as these metabolites are often produced and stored unevenly within plants. This is where innovative plant breeding comes into play. Using its methods, stable-yielding crops can be developed from wild plants.
Alternatively, isoprenoids can be produced through chemical synthesis from petrochemical feedstocks. However, due to the high complexity of these compounds, this process often results in low yields.
Biotechnological production of high-quality isoprenoids in microorganisms offers advantages such as predictable and stable year-round production, scalability, and simpler extraction and purification. However, the microorganisms must first be optimized to enable sustainable production. This ensures that biosynthesis proceeds to the desired product and overcomes potential bottlenecks.
Depending on the development and commercialization strategy for customized isoprenoid production, our department pursues plant-based and heterologous, microorganism-based approaches.