Student Portrait: Karolin Thielemann - Hungry Algae

2020-11-16 For her bachelor's thesis, the Environmental Sciences student is analysing the life cycle assessment of algae cultures that could help, for example, to produce a soy substitute from food waste. With her theoretical investigation, the 24-year-old won second place in the "Food for Thought" competition at the LCA Food 2020 conference.

Student Karolin Thielemann shows the researched algae in the laboratory. ©Marvin Sokolis / Leuphana
Student Karolin Thielemann shows the researched algae in the laboratory.

Galdieria sulphuraria is microscopically small, but could probably do great things: On the one hand, the alga performs photosynthesis, i.e. it consumes carbon dioxide. On the other hand it can also metabolise sugar. These abilities make it interesting for science. "Microalgae could replace soya in the long term," explains Karolin Thielemann. Galdieria sulphuraria consists of a protein-rich biomass that can be used as meat or feed substitute. The Environmental Sciences student is writing her bachelor's thesis on the life cycle assessment (LCA) of algae cultures under the supervision of Professor Dr. Daniel Pleissner at the Institute of Sustainable and Environmental Chemistry (ISEC). In her theoretical work, she looks at every step, from the preparation of the culture in bioreactors to the algae harvest, for example by centrifugation. She draws on literature data and checks the life cycle assessment of the individual steps: How much energy is consumed? What are the CO2 emissions? "In algae cultivation, some processes are already being implemented in practice. But not much is known about the environmental impact associated with the recycling of food waste," explains Karolin Thielemann. 

Algae cultivation can be a valuable addition to traditional agriculture: "It is independent of weather and light and reduces land use pressure because less land and water are needed," she says. Karolin Thielemann is an Environmental Science major. "The programme teaches relevant content from the natural and human sciences. The programme is very interdisciplinary. This is what makes Leuphana stand out," says the student. She put a lot of work into her thesis topic and, for example, took a module on modelling and preparing life cycle assessments. It was worth the effort: Daniel Pleissner suggested that she should participate in the scientific competition "Food for Thought" as part of the international LCA Food Conference 2020. The aim was to develop feasible ideas for using CO2 emissions from the cement industry to produce new biomass for food production. These processes often have a bottleneck: they involve high energy consumption or produce emissions themselves. Therefore, the idea for the competition not only had to be innovative, but the life cycle assessment had to be accurate. 

Because of the corona pandemic, Karolin Thielemann presented her ideas online at the conference: Algae would reduce CO2 emissions from the cement industry by photosynthesis. She also discussed the decomposition and conversion of food waste by algae. An international jury of experts asked critically: "I had invested a lot of time beforehand, so I was able to answer everything with confidence. Overall, I received very good feedback. It was an enriching experience," says the student. She was particularly pleased about the award: "Second place! I hadn't expected that at all". Her supervisor, Daniel Pleissner, is very satisfied with his student's performance: "She not only acquired sound knowledge in a very short time, but also presented it to an international jury in three challenging sessions," says the scientist. Once Karolin Thielemann has her bachelor's degree in her pocket, she can imagine pursuing a master's programme in the field of environmental research.


  • Apl.-Prof. Dr. Daniel Pleissner