Biosynthesis in Plants and Microorganisms
Carotenoids are a large class of natural terpernoid pigments; they encompass approximately 800 different structures. Their colour range extends from yellow via orange to red. Carotenoids are produced by plants, bacteria and fungi. The primary function of these pigments is to protect the photosynthetic apparatus from excessive light irradiation and to dissipate excess energy as heat. Humans can only obtain carotenoids through their diet, yet beta-carotene as provitamin A is essential for human vision, as are the carotenoids lutein and zeaxanthin, which are present and continuously replaced in the retina of the eye. Furthermore, carotenoids protect cells as radical scavengers and antioxidants.
Professor Gerhard Sandmann investigates how various organisms form carotenoids, the mechanism by which they are synthesised and how the synthesis is regulated. His research focuses on the enzymes and genes responsible for the individual steps in the complex process of synthesis, as well as on the evolution of carotenogenesis. Mechanisms of individual reactions are elucidated by kinetic measurements with heterologously expressed enzymes. Sandmann and his team identify newly discovered molecular structures by means of high-definition liquid chromatography and subsequent spectroscopic characterisation. In his research, Sandmann has successfully introduced carotenoid-biosynthesis genes from plants and bacteria into other organisms. The result of this so-called "metabolic engineering" has allowed him to genetically modify naturally occurring species such that they produce more carotenoids. Applied projects resulted in enrichment in potatoes or corn, as well as a greater tolerance for ultraviolet radiation in plants.
"The fascinating thing about my work is to discover unknown carotenoids that result from new metabolic combinations, and to elucidate the steps towards their synthesis in all their manifestations", Sandmann reports. He is highly interested in motivating his students to conduct research on metabolic pathways during their "Molecular Biosciences" and "Molecular Biotechnology" Master's Programme.
Gerhard Sandmann studied Biology and Chemistry in Mainz and Frankfurt and subsequently completed his doctorate in the field of plant physiology on the metabolism of fungi at the Goethe University Frankfurt. As a postdoctoral researcher at the University of Konstanz he examined enzymes containing copper and iron in algae and plants. The German Research Foundation (DFG) then supported him as a visiting researcher in Berkeley at the University of California, U.S.A. Back in Konstanz, he worked as a lecturer. In 1987, he received his Habilitation in the field of physiology and biochemistry of plants on the topic of redox proteins of the photosynthetic apparatus. He was appointed to a full professorship at the Goethe University Frankfurt in 1993.
Prof. Dr. Gerhard Sandmann
Institute of Molecular Biological Sciences
60438 Frankfurt am Main
Telephone: +49 (0)69 798 29611