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Expert in Chemical Engineering, Enzymes
Available for your Consulting and Expert Witness Needs
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Summary of Expertise:
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Listed with other top experts in: |
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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 in Expert's 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.
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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.
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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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Glucooligosaccharide oxidase is a newly discovered enzyme whose kinetic and stability properties are only superficially known. It holds promise of allowing the selective oxidation of the reducing ends of glucose, maltose, lactose, and maltooligosaccharides. Expert has subjected it to a thorough kinetic and stability analysis and have found that it is a most unusual enzyme, with an optimal pH for activity between 9 and 10.5, an optimal pH for stability of 6.5, a very low activation energy for catalysis, a very high activation energy for inactivation, and quite high Michaelis constants for maltooligosaccharides of different chain lengths. Even more strange, its N-terminal amino acid sequence bears no resemblence to any other oxidase and is only moderately homologous to a few proteins of vastly different function.
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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.
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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.
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Show Secondary and Basic Areas of Expertise | Localities:
Expert may consult nationally and internationally, and is also local to the following cities: Des Moines, Iowa;
Cedar Rapids, Iowa;
Waterloo, Iowa;
Iowa City, Iowa;
and Ames, Iowa.
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Degree |
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Subject |
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Institution |
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1964
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Ph.D.
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Chemical Engineering
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University of Pennsylvania
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1960
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A.B.
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Chemistry
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Princeton University
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Department |
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Title |
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Responsibilities |
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1979 to
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(Undisclosed University)
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Chemical Engineering
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Professor
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From 1974-79, Expert served as Associate Professor. Since 1979, he has been a full professor in the Chemical Engineering department and since 1992, an Anson Marston Distinguished Professor of Engineering.
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1968 to 1974
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University of Nebraska
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Chemical Engineering
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Assistant Professor
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1964 to 1968
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E.I. Du Pont de Nemours & Co.
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Research Engineer
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Associations/Societies
Expert is a member of the American Chemical Society (ACS) and a Fellow of the American Institute of Chemical Engineers (AIChE).
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Professional Appointments
Expert is Coordinator for two university-wide reciprocal exchange programs which Iowa State operates with schools outside the U.S. -- one with the University of Glasgow (1984-present), and the other with the Université de Lausanne-Ecole Polytechnique Fédérale de Lausanne (1985-present).
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Awards/Recognition
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).
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| Publications: |
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Selected Publications and Publishers
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- Protein Engineering
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- Industrial & Engineering Chemistry Research
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- Biotechnology and Bioengineering
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Recent Client Requests:
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Expert in glucose/xylose isomerase processing for consulting on cost and performance drivers for a glucose/xylose isomerase system.
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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.
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Recent Litigation Client Requests:
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Expert for consulting on simple fermentation of bacillus for breach of contracts case.
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Ethanol production expert for consulting on separation of liquids from thin stillage.
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Animal feed enzymes expert for consulting on enzyme stability in steam treated animal feed patent case.
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Expert for consulting on false advertising dispute involving refinded sugar products.
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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.
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| International Experience: |
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| Summary |
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Expert has extensive international experience. He has been a visiting professor in Switzerland and administers student-faculty exchange programs with universities in Scotland and Switzerland. He also has studied and consulted in the use of agricultural residues in developing countries.
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| Language Skills: |
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Description |
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Spanish
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Expert can speak and read Spanish.
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French
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He has speaking and reading proficiency in French.
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Italian, Portugese, and German
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He has some reading ability in these languages.
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| Additional Skills and Services: |
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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.
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Education
