HM Hochschule München University of Applied Sciences

Sustainable Bioprocess Engineering

Cultivating Microorganisms for Biocementation
Author: Ralf Kastner,

In the biotechnology lab at the Department of Engineering and Management, Frédéric Lapierre examines an array of bacterial samples, determines the final cell growth, measures enzyme activity, and takes microscopic images. The lab’s high-throughput cultivation platform can grow 48 bacterial cultures in parallel—a highly efficient process that enables Lapierre to quickly measure various parameters and discover which cultures are the most successful.

Lapierre researches cultivation processes for biocementing microorganisms at Munich University of Applied Sciences HM. Biocementation is a phenomenon by which certain bacteria are capable of depositing the mineral calcium carbonate on surfaces through their metabolic processes. Its potential industrial applications include repairing cracks in concrete, controlling dust levels in opencast mining, and trapping heavy metals in the soil to prevent groundwater contamination. The bacterium used in the lab, S. pasteurii, is found naturally in soils throughout the world. But knowledge of how to cultivate it efficiently and cost-effectively has been lacking until now.

The scientists determine the nutritional requirements of the bacteria in parallel experiments.
Doctoral researcher Frédéric Lapierre has substantially improved the bacteria growth.

Lapierre and his fellow scientists want to change this and are experimenting with a high-throughput cultivation platform and online monitoring. “We used common culture media to grow the bacteria but added specific nutrients to them in order to improve the process,” Lapierre explains. "By reducing production costs, we hope to make an important contribution to industrializing biocementation. The aim is to establish sustainable applications in the construction industry and in environmental engineering.” The researchers have achieved a fivefold increase in the production of the microorganisms compared with previously published bioprocesses. This is with just a 4% increase in the cost of culture media.

Research and Sustainability: The Perfect Combination

Lapierre grew up in France, close to the German border. He developed a passion for science at secondary school in nearby Saarbrücken, Germany, which led him to a degree in renewable energy and energy-system technology at the university in Saarbrücken. “I chose this course in the aftermath of the Fukushima disaster in 2011. In my bachelor’s degree, I specialized in biodiesel from microalgae, which was how I found my way into sustainable bioprocess engineering,” says Lapierre. Bioprocess engineering also formed the basis of his master’s degree, this time at the Institute of Space Systems in Stuttgart, where he studied ways of maximizing the reliability of algae cultivation. What does algae have to do with space travel? Lapierre explains: “A big challenge for long-duration crewed space missions is the supply of oxygen and food. Algae could form part of a self-sufficient biosphere.”

Biotechnology and Environmental Technology: Part of the Engineering and Management Degree

Lapierre realized his love of research during his bachelor’s degree. He found that this work offers no shortage of variety. As well as the intellectual side of research projects, there are many practical tasks to master in the laboratory. Studying for a doctorate is an exciting step for Lapierre. “When I saw the advert for the research topic at HM, I was immediately fired up by the chance to work in this sustainable and highly innovative research field in my discipline. What was more, Munich had always been my dream city since I visited conferences and trade fairs here during my studies,” he says.

Lapierre is very satisfied with the technical facilities and academic support offered by the university: “I get all the advice I need. At the same time, I have enough freedom to pursue my own ideas. Trust and openness are very important qualities to us in the research team to help us realize our full potential.”

In addition to the support he receives from Munich University of Applied Sciences HM and his co-supervisor there, Prof. Robert Huber, Lapierre is co-supervised by Prof. Jochen Büchs at the Chair of Biochemical Engineering at RWTH Aachen University.

Research in Bioprocess Engineering at HM

Research projects

  • MicrobialCrete: Interdisciplinary research project on the use of calcium carbonate produced by bacteria to develop new, biobased construction materials for restoring buildings and other construction-related applications.
  • MoP Bio: Development of a parallel microbioreactor with integrated measurement technology and individual control for each culture, allowing rapid optimization of cultivation conditions for 3D cell constructs.

Modern equipment

  • Microbioreactor for high-throughput cultivation, with biomass, pH, dissolved oxygen, and fluorescence determined online
  • Compatible pipetting robot for automated cultivation protocols
  • Online measurement of the oxygen transfer rate, carbon dioxide transfer rate, and respiratory quotient in shake flasks.
  • Online measurement of biomass in shake flasks
  • Automated feeding system for shake flasks

National and international collaboration

  • Diverse partners from industry and academia

Lapierre explains what motivates him: “In applied research, I can continually grow my knowledge—with a real hope that my particular field can make the world a little bit more sustainable.”

Broad Horizons

In addition to his research work, Lapierre supports partners in industry. All the results are shared. Often, partners have specific questions that Munich’s researchers can answer by running a few experiments.

Lapierre is also enthusiastic about outreach activities that complement his doctoral degree. By participating in the university’s Science Slam, he wants to make science and research more accessible. Winning the event and earning invitations to larger science slams all across Germany is something that has made a lasting impression on him. “I want to show that science isn’t a dry subject or just a lot of hard work. You can often use humor to reach a lot of people who would otherwise have little awareness of research. I believe the public also has a right to be informed about scientific findings; after all, they’re the ones funding research in Germany,” he says.

Working at a University of Applied Sciences

Lastly, Lapierre is actively involved in the university’s teaching program. He teaches engineering and management bachelor’s degree students in their fourth semester, covering the various areas of industrial biotechnology—from food production and pharmaceuticals to environmental biotech. Together with his doctoral supervisor Prof. Robert Huber, he also provides teaching for the master’s degree in applied research in engineering sciences (also known as the research master’s). Here, he teaches research methods, taking a practice-oriented look at scientific work and the German research landscape. He also regularly supervises final dissertations.

About to begin the final year of his doctoral degree, Lapierre is open-minded about what the future holds for him. He would like to continue research and development but would also be interested in a role as a science consultant or journalist.

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