Breakout Session I
Bioprocessing/Animal Agriculture Integration
Hans van Leeuwen
Hans van Leeuwen is a Professor in the departments of Civil, Construction and Environmental Engineering, and Agricultural and Biosystems Engineering at Iowa State University. His research interests include recovery of byproducts from liquid wastes and sludges, fungal treatment of food processing wastewater, reuse applications of residues from water softening, recovery of byproducts from liquid wastes and sludges, fungal treatment of food processing wastewater, and reuse applications of residues from water softening. He is currently working on a project called “Retooling Ethanol Industries: Integrating Ultrasonics into Dry Corn Milling to Enhance Ethanol Yield,” whose objective is to improve ethanol yield. The project team is investigating the considerable amounts of residual starch in the whole stillage, which are not easily accessible by enzymes during liquefaction. Generation of additional ethanol necessitates some form of pretreatment or use of an improved enzyme. One strategy to improve ethanol production is to integrate a high-power ultrasound into existing dry milling ethanol plants. The team hypothesizes that retrofitting a high-powered ultrasonic unit in existing ethanol plants will yield more ethanol. Dr. van Leeuwen taught in South Africa and Australia before coming to Iowa State University. He works internationally, advising industry and cities on wastewater treatment and water treatment residuals management practices, and on ships’ ballast water disinfestations. He serves examiner for the American Academy of Environmental Engineers and as an external dissertation examiner for universities in different countries.
For more information about his research involving cell
walls, visit
Cell Wall Biosynthesis.
Brian Kerr Brian Kerr is the USDA-ARS Research Leader of the Swine Odor and
Manure Management Research Unit located in Ames, IA. Dr. Kerr manages a group of four
additional scientists involved in animal physiology, gastrointestinal microbiology, food
safety, and air quality. His personal research interests include amino acid, fiber, sulfur,
and energy nutrition in nonruminants in an effort to reduce the impact of animal production
on the soil, water, and air environment. Recent research projects have dealt with
utilization of bioenergy co-products (distillers dried grains with solubles and crude
glycerin) on animal performance, carcass composition, meat quality, and nutrient excretion.
Allen Trenkle Allen Trenkle is a University Distinguished Professor of Animal
Science at Iowa State University. Dr. Trenkle has been the man with the answers to ruminant
nutrition questions at Iowa State University for more than 40 years. Since joining the ISU
animal science faculty in 1962, his “scientific curiosity” has helped him become an
internationally recognized expert in the research areas of factors regulating growth in
ruminants, improving the composition of beef and efficiency of ruminant production. Dr.Trenkle's areas of research are endocrine and cellular growth factors regulating growth
in ruminants; efficiency of beef cattle as influenced by altering growth rate and
composition; feeding systems to improve composition; and plant by-products as alternate
sources of nutrient for animals. He is known as a leading expert on the feeding of corn
milling industry co-products and by-products to livestock. Ethanol plant developers and
operators seek his advice, and producers rely on his expertise in incorporating distillers
grains into their livestock rations. 
