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 Expert  718652

Expert in Chemical Engineering, Enzymes

Available for your Consulting and Expert Witness Needs

Iowa (IA)
Education Work History Career AccomplishmentsPublicationsConsulting Services Expert Witness

Summary of Expertise: Listed with other top experts in: 
Expert has spent the majority of his professional career developing and refining the use of chemical engineering techniques to design biochemical reactors holding enzymes and microbial cells. Expert is an Anson Marston Distinguished Professor Emeritus in Iowa State University's Chemical Engineering program.

Expert works in the general area of biochemical engineering, and more specifically to mutate enzymes such as glucoamylase and the cellulases that hydrolyze polysaccharides, to determine sugar structures by computational molecular mechanics, to computationally dock oligosaccharides into the active sites of hydrolytic enzymes, and to use liquid and gas chromatography and mass spectroscopy to identify and quantify components of agricultural and food processing residues.


chemical engineering




Arrhenius equation


biochemical engineering


chemical reaction engineering


chemical reactor

He is an expert in applied enzymology, related process development, and scale-up. He works extensively in enzyme kinetics, and has published on enzyme immobilization. He has expertise in the characterization of soluble and immobilized enzyme function, specifically enzyme kinetics. He has a great deal of experience in the formulation of enzyme rate equations to design bioreactors in incorporating effects of temperature, pH, and diffusion limitation on enzyme activity and stability.

enzyme engineering


enzyme immobilization


enzyme kinetics


enzyme stability




enzyme activity assay


enzymatic catalysis

Expert is familiar with the structure and function of carbohydrates, specifically monsaccharide and disaccharide conformation calculated by molecular mechanics algorithms. He has experience with the production of sugars and corn syrup from malto-, cello-, and xylodextrins and their corresponding polysaccharides by enzyme-catalyzed hydrolysis with amylases, cellulases, and xylanases.









high fructose corn syrup
















oligosaccharide chemistry




protein structure






oligosaccharide structure

Expert has extensive experience in the use of gas-liquid and high-performance liquid chromatography to separate sugars and oligosaccharides, determine the chromatographic separation mechanisms, correlate the molecular properties with capacity factors, and the identification of hydroxylated organic molecules. Many food processing and agricultural residues have components that are of potential commercial interest. However, most residues are not found in central locations and others are either solid or have so many components that separation of those that could be sold at a profit is economically infeasible. Expert has been analyzing three liquid residues that are centrally located. Stillage, the bottoms from the distillation of ethanol, is a major byproduct that at present is fed to animals after concentration, an expensive and energy-intensive step. Gas chromatography of the derivatized mixture followed by mass spectroscopy to determine the organic composition from various sources such as corn, cane sugar molasses, citrus waste, and sweet cheese whey showed that there were no valuable components in sufficiently high concentrations to be economically separated. Similar analysis of the alkaline washes of canola, coconut, corn, cottonseed, peanut, soybean, and sunflower oils has identified a number of phosphatide fragments that can be separated by ion-exchange liquid chromatography for use as specialty raw materials and laboratory chemicals. At present he is investigating fluid from cattle rumens.

high-performance liquid chromatography


gas chromatography


liquid chromatography


high-performance liquid chromatography/mass spectroscopy


affinity chromatography

Expert is experienced in the use of mutagenesis, specifically site-directed, cassette, and random mutagenesis, to change the glucoamylase gene so that the expressed enzyme has different thermostability, selectivity, and optimal pH. He has used mutagenesis to determine the function of amino acid residues in the active site. He has extensive experience in the deletion of portions of the gene to determine the function of the glycosylated domain of glycoamylase. Expert has subjected glucoamylase to site-directed mutagenesis, where individual amino acid residues of the enzyme are changed by recombinant DNA technology. This, with the help of the three-dimensional structure of the enzyme, has yielded a number of major advances: 1) identification of one of the two acidic amino acids that catalyze the actual hydrolysis of the glucosidic bonds that link the D-glucosyl residues of starch and maltooligosaccharides; 2) a determination of how other amino acid residues in glucoamylase's active site bind glucosyl residues in the substrate; 3) substantial increases in enzyme thermostability; 4) significant increases in glucoamylase selectivity for glucose rather than byproduct formation; 5) a greater understanding of how glycosylation of glucoamylase affects its thermostability and secretion. Expert is also studying glucoamylase by advanced modeling methods, using available three-dimensional structures as a template. Hydrophobic cluster analysis allows the alignment of all glucoamylases for which an amino acid sequence is available and from this he can obtain the secondary structures of each. It is possible to infer the three-dimensional structures of all sequenced glucoamylases using other computational techniques. Finally, Monte Carlo simulation using the three-dimensional structure of the enzyme and optimal conformations of different actual and potential substrates yields optimal docked enzyme-substrate conformations.



protein engineering


site directed mutagenesis


chemical mutagenesis

Show Secondary and Basic Areas of Expertise
Expert may consult nationally and internationally, and is also local to the following cities: Des Moines, Iowa;  Cedar Rapids, Iowa;  Waterloo, Iowa;  and Ames, Iowa.

Often requested
with this expert:

Biochemistry and Enzymology
Technical Commercial Development support, Technology...
Carbohydrate Chemistry
Corn Syrup, Snack Foods

Year   Degree   Subject   Institution  
1964   Ph.D.   Chemical Engineering   University of Pennsylvania  
1960   A.B.   Chemistry   Princeton University  

Work History:
Years   Employer   Department   Title   Responsibilities

1974 to 2014


Iowa State University


Chemical and Biological Engineering


Distinguished Professor Emeritus


From 1974-79, Expert served as Associate Professor. From 1979 to 2014, he was a full professor in the Department of Chemical and Biological Engineering, and since 1992, an Anson Marston Distinguished Professor in Engineering. He retired in 2014.

1968 to 1974


University of Nebraska


Chemical Engineering


Assistant Professor


1964 to 1968


E.I. Du Pont de Nemours & Co.



Research Engineer


Career Accomplishments:

Expert is a member of the American Chemical Society (ACS) and is a Fellow of the American Institute of Chemical Engineers (AIChE).

Professional Appointments

Expert is Coordinator of a university-wide reciprocal exchange program with the Université de Lausanne and the Ecole Polytechnique Fédérale de Lausanne (1985-present).


Expert is a 1997 recipient of the Archer Daniels Midland/Protein & Co-Products Division Award given by the American Oil Chemists' Society (joint with coauthors S.L. Johansen, A. Sivasothy, M.K. Dowd, and E.G. Hammond) and a Phi Kappa Phi Centennial Medalist (1997). He has also received a number of honors from Iowa State, including a Faculty Citation from the school's alumni association (1997), the David R. Boylan Eminent Faculty Award in Research, College of Engineering (1996), and the Wilton Park International Service Award (1986).

Publications and Patents Summary

Expert has published over 150 peer-reviewed articles in scientific journals.

Consulting Services:
Recent Client Requests:
  • Expert for consulting on HFCS Central America Feasibility Study.
  • Expert in glucose/xylose isomerase processing for consulting on cost and performance drivers for a glucose/xylose isomerase system.
  • Expert in enzymes and bioreactors
Click the green button above to contact Expert for a free initial screening call regarding your expert consulting needs.  Expert is available for consulting to corporate, legal and government clients.  Remember, your initial screening call to speak with Expert is free.

Expert Witness:
Expert Witness Experience Summary:
Expert has participated in expert witnessing, both in federal court testimony and in preparing reports.
Recent Litigation Client Requests:
  • Expert for consulting on cane sugar litigation case.
  • Expert for consulting on simple fermentation of bacillus for breach of contracts case.
  • Ethanol production expert for consulting on separation of liquids from thin stillage.
  • Animal feed enzymes expert for consulting on enzyme stability in steam treated animal feed patent case.
  • Expert for consulting on false advertising dispute involving refinded sugar products.
Click the green button above to contact Expert for a free initial screening call regarding expert testimony, litigation consulting and support, forensic services, or any related expert witness services.  A few litigation needs include product liability, personal injury, economic loss, intellectual property (patent, trademark, trade secret, copyright), and insurance matters.  Remember, your initial screening call to speak with Expert is free.

International Experience:
Expert has extensive international experience. He has been a visiting professor in Switzerlan, Mexico, Germany, and Australia and administers a student exchange program with two universities in Switzerland. He also has studied and consulted in the use of agricultural residues in developing countries.

Language Skills:
Foreign Language   Description
Spanish   Expert can speak and read Spanish.
French   He has speaking and reading proficiency in French.
Italian, Portuguese, and German   He has some reading ability in these languages.

Additional Skills and Services:

Expert has participated in a video cassette course for engineers and scientists with limited biological background on Techniques and Applications of Biotechnology - Implications for Industry.


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