Maria Ghirardi — Research Fellow
Dr. Maria Ghirardi is a principal scientist at NREL, a research associate professor at the Colorado School of Mines, and a Renewable and Sustainable Energy Institute (RASEI) Fellow. She is involved in both basic and applied research and has had extensive experience working with photosynthetic organisms.
Dr. Ghirardi's work at NREL involves photobiological hydrogen production and covers metabolic, biochemical, and genetic aspects of algal metabolism.
Dr. Ghirardi co-discovered a sulfur-deprivation process, which allows sustained hydrogen production from algae. In addition her team identified three enzymes required for the assembly of [FeFe]-hydrogenases, which led to the development of a bacterial system for production of large quantities of active algal hydrogenase enzyme, a major breakthrough in research. They also initiated the use of molecular dynamics to create computational simulations of O2 and H2 gas diffusion through the hydrogenase enzyme, which led to the identification of two access pathways for O2 to the catalytic site of the enzyme.
This approach is now extensively used by groups in Europe to engineer oxygen tolerance into [NiFe]-hydrogenases. In collaboration with Dr. Matt Wecker from Genebiologics, Dr. Ghirardi developed a new selection method to isolate algal mutants with improved H2-producing capability, and made improvements in hydrogen photoproduction resulting from both physical and genetic manipulations. She also reported that algae can produce dramatically more hydrogen via the sun when the gas-phase to liquid-phase volume ratio in a bioreactor is increased. The observation helped bump up algae as major players in the search for the best alternative fuel of the future.
Recently, Dr. Ghirardi's group has focused on the development of hybrid systems involving a synthetic charge-separation device coupled to biological hydrogenase enzymes. This project is currently led by her colleague, Dr. Paul King. Dr. Ghirardi has authored more than 100 publications, holds four U.S. patents, has been featured as an invited speaker in many national and international conferences.
- Jorquera, O., A. Kiperstok, E.A. Sales, M. Embirucu, and M.L. Ghirardi. (2010). "Comparative energy life-cycle analyses of microalgal biomass production in open ponds and photobioreactors." Bioresource Technol. (101:4); pp. 1406-1413.
- Ghirardi, M.L., S. Kosourov, P.C. Maness, S. Smolinski and M. Seibert. (2010). "Algal Hydrogen Production," M. Flickinger, ed. Encyclopedia Industrial Biotechnology: Bioprpocess, bioseparation, and Cell Technology. Vol. 1, John Wiley and Sons, Inc.; pp. 184-198.
- Ghirardi, M.L. and P. Mohanty. (2010). "Oxygenic Hydrogen Photoproduction – Current Status of the Technology." Current Science (98); pp. 499-507.
- Eckert, C., A. Dubini, J. Yu, P. King, M. Ghirardi, M. Seibert, and P.C. Maness. (2010). "Hydrogenase genes and enzymes involved in solar hydrogen production," David Levin and Nuri Azbar, ed. State of the art and progress in production of biohydrogen. Bentham Science Publishers; pp. 8-24.
- Kosourov, S., M.L. Ghirardi and M. Seibert. (2011). "A truncated antenna mutant of Chlamydomonas reinhardtii can produce more hydrogen than the parental strain." Int. J. Hydrogen Energy (36); pp. 2044-2048.
- Ghirardi, M.L., L. Zhang, J.W. Lee, T. Flynn, M. Seibert, E. Greenbaum, and A. Melis (2000). "Microalgae: A Green Source of Renewable Hydrogen." (15); pp. 506-511.
- Kosourov, S.A.Tsygankov, M. Seibert. and M.L. Ghirardi (2002). "Sustained Hydrogen Photoproduction by Chlamydomonas reinhardtii – Effects of Culture Parameters." Biotechnol (78); pp. 731-740.
- Forestier, M., King P., Zhang, L., Posewitz, M., Schwarzer S., Happe, T., Ghirardi, M.L., Seibert M. (2003). "Expression of two [Fe]-hydrogenases in Chlamydomonas reinhardtii under anaerobic conditions." European Journal of Biochemistry (270); pp. 2750-2758.
- Posewitz, M.C., King, P.W., Smolinski, S.L., Zhang, L., Seibert, M., and Ghirardi, M.L. (2004). "Discovery of Two Novel Radical S-adenosylmethionine Proteins Required for the Assembly of an Active [Fe] hydrogenase." J. Biol. Chem. (279); pp. 25711-25720.
- Posewitz, M. C.; Smolinski, S. L.; Kanakagiri, S.; Melis, A.; Seibet, A.; Ghirardi, M. L. (2004). "Hydrogen Photoproduction Is Attenuated by Disruption of an Isoamylase Gene in Chlamydomonas reinhardtii." Plant Cell (16:8); pp. 2151-2163.
- Ghirardi, M.L., King, P.W., Posewitz, M.C., Maness, P.C., Fedorov, A., Kim, K., Cohen, J., Schulten, K., and Seibert, M. (2005). "Approaches to developing biological H(2)-photoproducing organisms and processes." Biochem Soc. Trans. (33); pp. 70-72.
View NREL Publications for this staff member.