Doctorated at the Technical University of Munich in 1969, he taught microbiology at the University of Pretoria from 1972 to 1987 (full professor from 1985 to 1987). Previously Director and Professor at the Federal Research Centre for Nutrition, Karlsruhe, Germany (1987–2007), and Honorary Professor at Karlsruhe Technical University from 1996 to 2007. Since 2007, he has been Full and Chair Professor at Handong Global University and a director at HEM Pharma Inc. He has authored about 400 publications, 78 book chapters, advisor to 120 Master’s/PhD students and served as President of the International Committee on Food Microbiology & Hygeine (1996-2002).