Research

Major directions:

- Metabolism in algae

- Biosynthesis and function of algal secondary metabolites

- Genome mining and reverse genetics in algae

- Interactions between microalgae and other microorganisms

Our research focuses on algal metabolism. Available genome sequences from algae are exploited to find hints for yet unknown metabolites, and to identify biosynthetic routes to known compounds. In the laboratory, we are combining genetic strategies with biochemical and analytical methods to elucidate the benefit of specific compounds for the algal cell. We hope that our research will provide ecological insights into algal lifestyle and improve our understanding of how algae interact with their environment and other organisms. In addition, the investigation of algal secondary metabolism may lead to the discovery of pharmaceutically or biotechnologically useful compounds.

 

Selected research topics:

 

1. Biosynthesis, structure and function of polyketides

Polyketides are a large and diverse class of secondary metabolites produced by bacteria, fungi and plants. Some dinoflagellate algae produce polyketide toxins during blooms; polyketides may thus contribute to the damage caused by such blooms (intoxications of marine animals and humans). Surprisingly, genome sequencing projects have unveiled a number of polyketide biosynthetic genes also in non-toxic algae. We intend to identify the corresponding polyketides and their function in sequenced algae.

Further reading: Sasso S., Pohnert G., Lohr M., Mittag M., Hertweck C., "Microalgae in the postgenomic era: a blooming reservoir for new natural products", FEMS Microbiol. Rev. 36, 761-785 (2012) (addendum: FEMS Microbiol. Rev. 37, 284 (2013))

 

2. Biosynthesis and function of ovothiol

Ovothiols are thiohistidines produced by some bacteria, algae, trypanosomatids and marine invertebrates, but absent from mammals. Ovothiol C is known to protect sea urchin eggs from extracellular hydrogen peroxide, which is required for the crosslinking of the fertilisation envelope (E. Turner et al., Science 242, 939-941 (1988)). In algae, little is known about the function of ovothiol. For example, it may have a role as an antioxidant, in redox regulation, signalling or metal homeostasis. Our aim is to shed light on the biosynthesis and function of ovothiol in algae. 

 

3. The metabolic profile of the marine microalga Ostreococcus tauri

With its cosmopolitan distribution and capability to form blooms, the unicellular marine alga Ostreococcus is of ecological significance. Since it has a small diameter (ca. 1 µm) and genome size (12.6 Mb), it has been speculated that O. tauri may represent a minimal version of a photosynthetic eukaryote (E. Derelle et al., Proc. Natl. Acad. Sci. U. S. A. 103, 11647-11652 (2006)). At the metabolic level, Ostreococcus is hardly characterised to date. In this project, we aim at describing the metabolic profile of O. tauri under different growth conditions as an essential step to understand how this ecologically important alga adapts to changes in environmental conditions, and to engineer algae for biotechnological applications such as the production of high-value compounds.

 

 

 Website_PKS_Ovothiol_120530

 

(last updated on 15 July 2014)