Expert Details

Expert in Chemical Engineering, Enzymes

Expert ID: 718652 Iowa, USA

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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.

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.

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.

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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.

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.

Expert may consult nationally and internationally, and is also local to the following cities: Des Moines, Iowa - Cedar Rapids, Iowa - Waterloo, Iowa - Ames, Iowa

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Education

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

Work History

Years Employer Title Department Responsibilities
Years: 1974 to Present Employer: Undisclosed Title: Distinguished Professor Emeritus Department: Chemical and Biological Engineering Responsibilities: 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.
Years: 1968 to 1974 Employer: University of Nebraska Title: Assistant Professor Department: Chemical Engineering Responsibilities:
Years: 1964 to 1968 Employer: E.I. Du Pont de Nemours & Co. Title: Research Engineer Department: Responsibilities:

International Experience

Years Country / Region Summary
Years: to Present Country / Region: Summary: 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.

Career Accomplishments

Associations / Societies
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.
Awards / Recognition
Expert is a 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. He has also received a number of honors from Iowa State, including a Faculty Citation from the school's alumni association, the David R. Boylan Eminent Faculty Award in Research, College of Engineering, and the Wilton Park International Service Award.
Publications and Patents Summary
Expert has published over 150 peer-reviewed articles in scientific journals.

Additional Experience

Expert Witness Experience
Expert has participated in expert witnessing, both in federal court testimony and in preparing reports.
Training / Seminars
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.

Language Skills

Language Proficiency
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.

Fields of Expertise

chemical engineering, bioreactor, Arrhenius equation, biochemical engineering, chemical reaction engineering, chemical reactor, enzyme engineering, enzyme immobilization, enzyme kinetics, enzyme stability, enzymology, enzyme activity assay, enzymatic catalysis, carbohydrate, dextrin, amylase, disaccharide, high fructose corn syrup, saccharide, cellobiose, cellulose, cornstarch, hemicellulose, hydrolase, trehalose, oligosaccharide chemistry, glucose, protein structure, maltose, maltotriose, oligosaccharide structure, high-performance liquid chromatography, gas chromatography, liquid chromatography, high-performance liquid chromatography/mass spectroscopy, affinity chromatography, mutagenesis, protein engineering, site directed mutagenesis, chemical mutagenesis, carbohydrate nuclear magnetic resonance spectroscopy, oligosaccharide synthesis, enzyme modification, chemical industry, corn meal, industrial biotechnology, thermal stability, raffinose, food biotechnology, enzyme analysis, cation-exchange chromatography, enzyme inactivation, enzyme inhibitor, anion-exchange resin, conformation, Oxycell bioreactor, hollow fiber bioreactor, carbohydrate analysis, pH, chemical separation, chemical reactor engineering, chemical reactor model, food sweetener, reaction-rate equation, chemical reaction, anion, chemical reactor design, corn syrup, enzymal food processing, fermentation, chemical reaction mechanism, chemical kinetics, enzyme technology, applied enzymology, algorithm, oligosaccharide, amylopectin, enzyme, syrup, starch, protein purification, polysaccharide, molecular biology, modeling, in vitro mutagenesis, immobilized enzyme, gel permeation chromatography, gel electrophoresis, gas-liquid chromatography, industrial fermentation, enzyme production, dextran, chromatography, chemistry, biotechnology, biochemical separation, industrial biochemical process, bacterium, anion exchange, amylose, acid

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