John O. Baker

John O. Baker

Senior Scientist

Photo of John Baker
(303) 384-7770
At NREL Since: 

John Baker's core expertise is as a chemical kineticist specializing in the kinetics of enzyme-catalyzed reactions. His interdisciplinary work at NREL has taken him through such diverse areas as microbiology, chromatographic methods development, calorimetry, fluorescence spectroscopy, and practical fluid mechanics. Since joining the Enzyme Technology Focus Team in 1984, he has taken on the task of developing experimental methods and data analysis approaches that can bridge the fields of fundamental scientific studies of cellulase structure and function and the bottom-line application of these enzymes in economically viable bioconversion processes.

Dr. Baker led the development of the diafiltration saccharification assay as a means of measuring cellulase action on biomass under simulated SSF conditions. He continues to adapt this and other assay approaches to meet the changing needs of an evolving process to evaluate enzyme performance. In combination with these direct measurements of enzyme activity, he uses expertise developed in the areas of protein microcalorimetry and fluorescence spectroscopy to study the structures of cellulases, both naturally occurring and genetically engineered, to assess their stability and utility under varying process conditions. Dr. Baker was heavily involved in the evaluation of enzyme samples produced by NREL's first-round Cellulase Initiative industrial subcontractors, in providing feedback to the subcontractors, and in formulating performance criteria to guide future efforts. He continues to participate in industrial enzyme-technology collaborations.


  • 1967 B.A., Biochemistry, Rice University

  • 1979 Ph.D., Biochemistry, Texas A&M University

Selected Publications 

  1. Baker, J.O.; McCarley, J.R.; Lovett, C.H.; Yu, W.S.; Adney, T.R.; Rignall, T.B.; Vinzant, S.R. Decker, J. Sakon, Himmel, M.E. (2005). "Catalytically enhanced endocellulase Cel5A from Acidothermus cellulolyticus." Appl. Biochem. Biotechnol (121); pp. 129-148.
  2. Baker, J.O.; Vinzant, T.B.; Ehrman, C.I.; Adney, W.S.; Himmel, M.E. (1997). "Use of a new membrane-reactor saccharification assay to evaluate the performance of cellulases under simulated SSF conditions: Effect on enzyme quality of growing Trichoderma reesei in the presence of targeted lignocellulosic substrate." Appl. Biochem. Biotechnol. (63:5); pp. 585-595.
  3. Baker, J.O., Adney, W.S.; Thomas, S.,R.; Nieves, R.A.; Chou, Y.-C.; Vinzant, T.B.; Tucker, M.P.; Laymon, R.A.; Himmel, M.E. (1995). "Synergism between purified bacterial and fungal cellulases." ACS Symp. Ser (618); pp. 113-141.
  4. Baker, J.O. and M.E. Himmel (1993). "Thermal and pH stress in thermal denaturation of Trichoderma reesei cellobiohydrolase I: Supporting evidence for a 2-transition model." ACS Symp. Ser. 516 pp. 83-101.
  5. Baker, J.O. (1988). "Metal-Buffered Systems." Methods Enzymol (158); pp. 33-55.
  6. Baker, J.O.; Prescott, J.M. (1983). "Aeromonas aminopeptidase – pH-dependence and a transition-state analog inhibitor." Biochemistry (22); pp. 5322-5331.