Todd Callaway is a Professor in Ruminant Nutrition and Gastrointestinal Microbiology in the Department of Animal and Dairy Science at the University of Georgia. Todd received his B.S. and M.S. in Animal and Dairy Science from the University of Georgia, and Ph.D. in Microbiology from Cornell. Dr. Callaway joined the Agricultural Research Service of the USDA (USDA-ARS) in the Food and Feed Safety Research Unit in College Station, Texas for 18 years. His research focuses on the role of the gut microbiota in the nutrition of cattle, and how the complex environment of the cattle gastrointestinal tract can impact food safety and production efficiency.

Dr. Hermann J. Heipieper is Environmental Microbiologist and since July 1999 head of the group Microbial Adaptation and Contaminant Degradation of the Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.