J. Greg Zeikus
Professor Emeritus
- B.A. 1967, University of South Florida
- M.A. 1968, Ph.D. 1970, Indiana University
- Postdoctoral Associate, 1970-72, University of Illinois
- Faculty Member, 1972-84, University of Wisconsin
- Visiting Professor and Humbolt Fellow, 1976-77, Universität Marburg
- Visiting Research Fellow, 1981-82, Institute Pasteur
- Doctor of Honoris Causa in Applied Biological Sciences, 1992, University of Ghent, Belgium
- Executive Director, 1984-86, Michigan Biotechnology Institute, Lansing, Michigan
- President, CEO, 1986-2000, MBI International, Lansing, Michigan
zeikus@msu.edu
410 Biochemistry Building
Michigan State University
East Lansing, MI 48824-1319
Office: 517-353-5556
Lab: 517-353-4674
FAX: 517-353-9334
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J. Greg Zeikus Research Interests
Research in my lab focuses on the design and control of industrial biocatalysts.
The use of biocatalysts (i.e., microbes and enzymes) in industrial processes
has been greatly expanded by the application of new bioengineering technologies
including genetic engineering. Industrial bioprocesses involve the use
of biocatalysts in: biochemicals and biomaterials production, drug synthesis
and manufacture, sensors and diagnostics, food and feed production, and
waste treatment systems. Developing robust biocatalysts that function
under harsh physical chemical processing conditions is a real challenge
that has recently been aided by using extremophic organisms and their
enzymes as model systems infundamental and applied research.
Our research on extremophilc enzymes involves determining and applying
rational design parameters for controling biocatalyst stability, activity,
and chemical yield.
Our work on the design and control of industrial biocatalysts includes
the engineering of thermozymes by protein and genetic engineering techniques;
microbial organic acid and alcohol fermentations by metabolic engineering
of pathways and enzyme regulations; and anaerobic biodegradation granules
by ecoengineering the performance of mixed microbial populations.
Our work on enzymes from thermophiles and hyperthermophiles focuses on
six enzymes: xylose (glucose) isomerase used in fructose sweetener manufacture;
amylopullulanase, (an a 1-6 and a
1-4 bond cleavage enzyme) used in starch processing; secondary alcohol
dehydrogenase used in chiral chemical synthesis; alkaline phosphatase
used in diagnosticsand adenylate kinase. The goals of our research are
to understand the molecular determinants for enzyme thermal stability
and activity; and to redesign the enzymes for enhanced activity and stability.
The approach used is to: clone, sequence, analyze and express the respective
genes; identify the function of the active site residues by site-directed
mutagenesis and activity analysis; relate specific amino acid functions
to crystal structure; identify structural features associated with thermostability
and, relate enzyme thermostability and activity features to protein biophysical
and thermodynamic properties including conformational flexibility, resistance
to unfolding, denaturation kinetics, heat capacity, etc.