Kesen Ma

Kesen Ma
Associate Professor, Undergraduate Advisor (Biology)
Location: B1 379C
Phone: 519-888-4567 x33562


Kesen Ma carries out research in physiology and enzymology of hyperthermophiles, a group of microorganisms growing at temperatures of boiling water. Metabolic processes involved in the conversion of biomass to biofuels and bioproducts at elevated temperatures are studied. Novel thermostable enzymes functioning in these processes are identified and characterized. His research provides further understanding of the mechanisms of protein thermostability, unusual metabolic pathways and biocatalysis at high temperatures, and also explores potential applications of these biocatalysts in pharmaceutical and other industrial processes.

Hyperthermophiles are a group of microorganisms isolated mainly from deep sea hydrothermal vents and capable of growing at temperatures of ³ 90°C. The majority of hyperthermophiles are classified as Archaea that are considered as the most slowly evolving of all microorganisms. The metabolism at such high temperature (>100°C) raises many biochemical questions: how are biomolecules stabilized? are there new metabolic pathways and novel metabolites? do these pathways contain unusual enzymes with yet unknown catalytic mechanisms? what is the relationship between structure and function of biomolecules that evolved under extreme conditions? Answering these questions will provide valuable insight into high temperature biochemistry and protein engineering.

Novel enzymes are involved in alcohol fermentation at high temperatures, which include both alcohol dehydrogenase and pyruvate decarboxylase. It is particularly interesting to characterize new types of acetaldehyde-producing enzymes from hyperthermophiles. This research will provide further information required for developing a more efficient system for alcohol fermentation at high temperatures.

Research Interests

  • Microbiology
  • Biochemistry and enzymology
  • Protein purification and analysis
  • Metal-containing proteins
  • Microbial physiology
  • Fermentation
  • Molecular biology
  • Hyperthermophiles
  • Biochemistry and Biophysics
  • Bioinformatics, Systematics and Evolution
  • Molecular Genetics
  • Renewable Energy


  • 1989 Ph.D. Microbial Biochemistry, Philipps-Universitat Marburg, Germany
  • 1984 M.Sc. Microbiology, Academia Sinica, Taiwan
  • 1982 B.Sc. Microbiology, Wuhan University, China


  • 1985 Research Fellow, Max-Planck Institute, Philipps-Universität Marburg
  • 1982 Graduate Scholarship, Academia Sinica, Beijing

Professional Associations

  • Canadian Society of Microbiologists
  • American Society for Microbiology
  • International Society for Extremophiles
  • Canadian Society for Molecular BioSciences

Affiliations and Volunteer Work

  • Centre for Bioengineering and Biotechnology
  • Waterloo Centre for Microbial Research


  • BIOL 240 - Fundamentals of Microbiology
    • Taught in 2019, 2020, 2022, 2023, 2024
  • BIOL 348L - Laboratory Methods in Microbiology
    • Taught in 2019, 2020, 2022, 2023, 2024
  • BIOL 448 - Microbial Physiology and Biochemistry
    • Taught in 2019, 2021, 2022
  • BIOL 618 - Advanced Microbial Physiology
    • Taught in 2022

* Only courses taught in the past 5 years are displayed.

Selected/Recent Publications

  • Alharbi, F.; Knura, T.; Siebers, B.; Ma, K. 2022. Thermostable and O2-Insensitive Pyruvate Decarboxylases from Thermoacidophilic Archaea Catalyzing the Production of Acetaldehyde. Biology 2022, 11, 1247.
  • Wang, Q., C. Sha, H. Wang, K. Ma, J. Wiegle, A. E.-F. Abomohra, and W. Shao. 2021. A novel bifunctional aldehyde/alcohol dehydrogenase catalyzing reduction of acetyl-CoA to ethanol at temperatures up to 95°C. Scientific Reports. 11(1):1050-1058. DOI: 10.1038/s41598-020-80159-7
  • Kim, S.D., X. Zhu, Y. Jin, T.N. Nguyen, K. Johnston, A. Li, X. Zhang, J. Zhao, K. Ma. 2019. Differential solvent production by Clostridium beijerinckii NRRL-B593 grown on carbohydrates and peptides. Advances in Biochemistry and Biotechnology. 7(3):1091
  • Asokumar, N., S. D. Kim and K. Ma. 2018. Alcohol dehydrogenases catalyzing the production of ethanol at high temperatures. Innovative Energy & Research. 7: 219. doi: 10.4172/2576-1463.1000219
  • Tse, C., N. E. Ibrahim, and K. Ma. 2017. Characterization of an alcohol dehydrogenase of the hyperthermophilic archaeon Hyperthermus butylicus. Journal of Applied Microbiology and Biochemistry. 2:1-12
  • Ibrahim, E. N. and K. Ma. 2017. Industrial Applications of Thermostable Enzymes from Extremophilic Microorganisms. Current Biochemical Engineering. 4(2):75-98. DOI: 10.2174/2212711904666170405123414


  • Provisional patent application “A thermotable biocatalyst for production of ethanol and stereo-specific compounds” with a serial #: 61/136,714. 2008
  • PTA application for “Thermostable alcohol dehydrogenase derived from Thermococcus guaymasensis with a pub # WO/2010/034115 in 2010, and it has a national phase date on March 26, 2011
  • US patent 8476051,“Thermostable alcohol dehydrogenase derived from Thermococcus guaymasensis” issued on July 2, 2013 and is valid until March of 2031