Junior Professor Sabrina Hedrich studies microorganisms that love extremes

Junior Professor Sabrina Hedrich
Since the beginning of 2020 Junior Professor Sabrina Hedrich has been teaching and researching at the Institute of Biosciences. She examines microbes that have adapted particularly well to extreme conditions such as high temperatures, extremely low pH values, and toxic heavy metal concentrations.

While most other bacteria and co. die at high temperatures and in acidic solutions, this is where the objects examined by the biohydrometallurgy expert feel at home. The junior professor deals with so-called acidophilic and thermophilic (acid and heat-loving) microorganisms and examines how these can be used to extract metal from ores and industrial residues (e.g. electronic scrap).

“When the pH value is low, we use a bioreactor to get the microbes to dissolve the metals from insoluble sulfides. The valuable metals can then be extracted from the solution using various hydrometallurgical processes - and that with little energy input and without the harmful exhaust gases typical of pyrometallurgical processes,” explains the alumna of TU Bergakademie Freiberg, who studied applied natural sciences in the early 2000s. The junior professor is currently researching, for example, how platinum and palladium can be extracted from a platinum ore from South Africa with the help of bioleaching.

With the new junior professorship, the process of biological water treatment is also moving into the focus of research. “In this area, we apply the findings to the treatment of process water from metallurgy or mining water. The residual content of the metals can be extracted even more economically from such solutions thanks to treatment with microorganisms,” says Junior Professor Sabrina Hedrich.

From the basics to process development

Up to 20 liters of the metal-containing leaching solution with a solids content of up to 20% can be processed in a so-called stirred reactor in the test facilities of the Institute of Biosciences. “In the future, our goal is to transfer the process to a pilot scale,” explains the scientist.

In particular, the microbial fundamentals, which enable the optimization of bio-leaching possible, interest Junior Professor Sabrina Hedrich: "I take a close look at the organism and ask how it works and how it can be stimulated with the help of substrates and by adjusting the temperature and pH value to crack open the various ores". Students of applied natural sciences, chemistry, and geoecology learn both microbiological and genetic basics in the scientist's courses. They also get to know the technology of bioreactors and understand how microorganisms are used in biotechnological processes. "I look forward to inquiries about thesis or project work and internships with students and doctoral candidates from all fields of study and subject - just speak to me," says Junior Professor Sabrina Hedrich.