- Started research career in Microbiology with emphasis on beneficial microorganisms.
1972 - 1987
- First Senior Lecturer and finally Full Professor in Microbiology at the University of Pretoria, SA.
1987 - 2007
- From 1987 to 2007: Head and Director of the Institute of Hygiene and Toxicology in Karlsruhe (Germany)
1989 - 2015
- Member of the Advisory Council of the German Food and Nutrition Industry
- Since 1990 to present President of the International Committee on Food Microbiology and Hygiene of the IUMS
- From 2007 to 2013: full Professor in the School of Life Sciences, Handong Global University.
- Since March 2013, Chair Professor, Dept. of Advanced Green Energy and Environment
- 1 January
- Holzapfel Effective Microbes established
- 21 May ~ NOW
- A $ 600,000 scale contract with Better Air(Israel) about transfer of effective microbial technology for environmental purification
- 12 June
- Establishing a US sales subsidiary HEM-ACE with US NutraSource Inc.
- 22 August
- MOU Signed with Lactomason and agreement on technology transfer
- 1 April
- Establishment of HEM Gwanggyo Research Center in Suwon, South Korea.
- 8 June
- Recognized as an affiliated research institute
- 1 September
- Establishment of "Han-dong SaM" joint venture with Pohang Handong Global University, Pohang