On December 20, 2020, Sarah Lisa Hoffmann successfully completed her dissertation work, which dealt with a new sustainable production route for the amino acid lysine.
Sarah explored a new route for the use of macroalgae, a new type of raw material source from the ocean, which is regarded as third generation renewable through its rapid growth without any need for fertilizers or pesticides and the climate-friendly fixation of carbon dioxide from the increasingly acidic oceans and the atmosphere. To this end, Sarah gradually upgraded the soil bacterium Corynebacterium glutamicum into a highly efficient, algae-using cell factory to produce the feed amino acid lysine, a major product of industrial biotechnology. The world lysine market of 2.5 million tons per year is obtained almost exclusively from terrestrial sugars and thus consumes valuable arable land. For the use of the sugar alcohol mannitol, a main component of algae extracts, Sarah systematically reprogrammed the metabolism of the bacterium, built in an assimilation route, and gradually adapted the redox metabolism. Working with Prof. Christoph Wittmann as doctoral supervisor, Sarah succeeded in the efficient conversion of mannitol into lysine. Finally, she demonstrated the entire value chain in the laboratory: from the alga to the finished product in a cascaded process.
The PhD defense was carried out as a hybrid event due to the corona measures. Unfortunately, we were only able to celebrate to a limited extent and convey our congratulations by waving from a safe distance. Our newly graduated Sarah even had to put on her doctoral hat by herself – also the legendary journey in the decorated doctoral student's car could not take place. We are all more than happy with Sarah and would like to make up for her celebration with all honors as soon as it is possible again safely and without restriction.
Photos: Impressions of the day of defense (c) iSBio