Clemens Posten studied biology and electrical engineering in Bochum and Hannover (Germany) achieving two diploma degrees (1983). This choice was based on his passion for combining science and engineering. His doctoral thesis at the Institute of Automatic Control dealt with "modeling and automation of ethanol production using the anaerobic bacterium Zymomonas mobils". Incidentally, this topic has become topical again today. This not only allowed him to pursue his interests further, but also to immerse himself in online and offline computer applications in biotechnology, a new topic at the time. He was able to acquire further knowledge in this direction through theoretical expertise during his post-doc at the "Institute for System Dynamics" in Hamburg and his work as head of the "Modeling and Automation" working group at the GBF in Braunschweig (1989-1995). During these activities he got to know numerous practical bioprocesses and maintained close contacts to industry until today. In fact, his extensive knowledge of bioprocess engineering dates back to this time. Due to his numerous publications, he was appointed to the new professorship of "Bioprocess Engineering" (1995) in the faculty of process engineering. In teaching, he was entrusted with the international study course "Biotechnology" at the "�cole sup�rieure" in Strasbourg and as co-founder in the study course "Bioengineering" in Karlsruhe (today KIT). He pursued the communication of his knowledge and his great overview with the same passion as science. Many students chose his institute to write their theses. During this time, numerous including industry-related projects (about 2 Mill last 5 years) were acquired and successfully carried out by his employees, including, of course, their own doctorates. The results are recorded in more than 200 peer-reviewed publications, 5 books, and 5 patents. Prof. Posten also became further known through his active memberships in scientific associations (IFAC, esbes, dechema, eaba) and editorial boards of highly ranked journals. His scientific interests continue to focus on bioprocess engineering in the fields of particle biotechnology and photo-biotechnology. Design of photo-bioreactors, modelling, control, and optimization of photo-bioprocesses, interaction between reactor and cell physiology are practical spin-offs. Now he continues his career and his passion sharing his knowledge as co-founder of the consultant firm bio-compete.