Dismukes, Charles

	Phone:	732-445-1489
	E-mail:
	FAX:	732-445-5312
	Lab:	WL-102
	Office:	WL-211
	Mail:	Chemistry & Chemical Biology, 610 Taylor Road, Piscataway, NJ 08854

Research Summary

G. Charles Dismukes is a member of the Rutgers faculties of the Department of Chemistry & Chemical Biology, the Waksman Institute and the Biochemistry and Microbiology Department. His research interests focus on biological and chemical methods for renewable solar-based fuel production, photosynthesis, metals in biological systems and tools for investigating these systems. His published works describe the biology and chemistry of oxygen production in natural photosynthetic systems, the synthesis and characterization of bioinspired catalysts for renewable energy production, the use of microorganisms as cell factories for the production of bio-fuels from renewable sources. Graphical details can be found at http://www.princeton.edu/~catalase/. He is Principal Investigator of the BioSolarH2 team, a multi-institutional research center focusing on microbial hydrogen: http://www.princeton.edu/~biosolar/.

We are pursuing two main goals that address both the fundamental science and practical applications of renewable energy production via I) bioinspired catalysts for H₂ + O₂ production via water splitting, and II) sustainable biofuels and CO­₂ conversion (hydrogen and liquid fuels).

I. Catalysts for Water Oxidation & Photoelectrochemical Cells (NIH, ACS, AFOSR). The development of sustainable catalysts that use materials of high natural abundance and long-term stability is a major goal of this project. My laboratory is closely linked to the discovery of the catalytic site for photosynthetic water oxidation. Armed with nature's emerging blueprint for design of a water oxidation enzyme, we are synthesizing bioinspired inorganic complexes and materials for use in hybrid photoelectrochemical cells as water splitting catalysts. Our proposed mechanism for photosynthetic water oxidation serves as the guiding principle for catalyst design. As primary example, we have synthesized a family of manganese-oxo "cubane" complexes containing the first molecular example of a transition metal-oxo cubane core (M₄O₄^5+/6+/7+). These complexes exhibit extraordinary reactivity as oxidation catalysts, being capable of C-H bond cleavage of saturated hydrocarbons and oxo transfer to various substrates. (Carrell, Cohen et al., 2002). Most relevant is their reactivity in O₂ evolution from water (see figure to the right). Their metrical and electronic structures have been characterized by a range of physico-chemical methods leading to a clear picture of how they produce O₂ from water in the gas phase (Ruettinger and Dismukes 1997; Rüttinger, Campana et al. 1997; Ruettinger, Ho et al. 1999; Ruettinger, Yagi et al. 2000; Ruettinger and Dismukes 2000; Yagi, Wolf et al. 2001; Carrell, Bourles et al. 2003; Maneiro, Ruettinger et al. 2003; Wu, Sellitto et al. 2004).

Bioinspired Project 1. Solar Cell for Water Splitting. Our recent breakthrough is the discovery that cationic cubane derivatives become activated to catalyze sustainable O₂ evolution and proton evolution from water when drawn into proton-conducting (Nafion) membranes containing sulfonate anions (Brimblecombe et al, 2008). Both electrical bias and light were required in this first example. These catalysts achieve thousands of turnovers with low loss of activity.

Our next step is to examine the functioning of these catalysts upon integration with photovoltaic cells (both silicon and dye-sensitized TiO₂ cells), thereby permitting the direct use of solar radiation for the production of hydrogen from water without additional electrical bias. We have constructed our first prototype dye-sensitized photo-cell having the design and performance described in the figure to the left.

The Ru^II dye absorbs photons, causing promotion of an electron into the electrode. The electrochemical potential of the resulting Ru^III species (ca. E^o = 1.6 V vs Ag/AgCl) is sufficient to oxidize the reduced intermediates of cubane 1 that form during H₂O oxidation. When illuminated, the cell splits water spontaneously (forming H₂ and O₂ from an electrolyte or distilled water), without application of a potential bias. The initial current density is 47 μA/cm² under one sun illumination (AM1.5) which corresponds to a hydrogen conversion efficiency of around 0.05%. This experiment is a "proof of concept." It demonstrates that visible light alone in the absence of an electrical bias is sufficient to photooxidize water in this system.

Figure 3.3. A) (left) Photoelectrochemical cell design; B) (right) Short circuit current produced by this cell: Blue:Cubane/Nafion/Dye/TiO2, Red: Nafion/Dye/TiO2, Black: TiO2 only. Open Circuit Voltage: 0.62V, Electrolyte: neat water or aqueous 0.1M Na2SO4.

Bioinspired Project 2 (DOE-BES application). Synthesis of bioinspired heterobimetallic "cubane" molecules. There is need for more active catalysts that are oxidized more efficiently at the electrode (higher surface area requirement) and which are intrinsically more active in water oxidation. We are working on new methods for covalent attachment of these catalysts to carbon electrodes and metal oxide semiconductors to increase charge injection efficiency. These will be described.

Bioinspired Project 3 (DOE-BES application). Density Functional Theoretical calculations have revealed that there is an activation barrier to O₂ release from the Mn₄O₄ⁿ⁺ core arising from strong directional bonding within each Mn₂O₂^m+ subcore. To overcome this limitatioin we are synthesizing new homonuclear metal-oxo cubanes and heterobinuclear manganese-metal-oxo cubane derivatives containing two distinct transition metal ions. The target of the latter project is the isolation of the Co₂Mn₂-cubane core derivatives using as terminal ligands the proven diarylphosphinates. Toward this end we have recently isolated a new homonuclear cobalt derivative with composition L₆Co₄O₄ L = diarylphosphinate. The proposed synthetic route to these clusters will be described.

Bioinspired Project 4 (Toyota application). Electrosynthesis of reactive transition-metal oxide phases as catalysts for renewable hydrogen fuel production by water oxidation. In this project the aim is to use chemical synthetic approaches that enable the electrosynthesis of unstable solid state phases of transition-metal oxides that are more chemically reactive towards water cleavage than are thermodynamically stable phases. The idea is to create these phases by the judicious introduction of non-transition metal dopants (group IIA and IIIB metals) during electrolysis. The dopants disrupt the formation of low energy phases by creation of coordinatively unsaturated sites that allow substrate binding and activation. This same concept is used in nature for the assembly of the photosynthetic water oxidation center comprised of a CaMn₄O_x core as seen by the assembly of the cluster during biogenesis. These phases will be amorphous or polycrystalline analogs produced by various methods that disrupt the long range order of the preferred crystalline phases. These methods include: 1) doping of the TM precursor solutions with non-oxidizable ions such as alkaline earth ions (relaxes the directional bonding angles required by d orbital bonding in TMs), 2) replacement of aqueous solutions of precursor salts with ionic liquids (gives new TM phases that are unstable in water), 3) electrosynthesis of TM phases from solutions containing conducting polymers or semiconductor nanoclusters to facilitate the electrical contact between the catalyst phase in the photoactive electrode or semiconductor. Our preliminary results have shown that electrosynthesis of a more catalytically active phase of MnO₂ can be achieved using a proton-conducting polymer phase to affect the oxidation of Mn²⁺ from solution. We believe that this relatively new approach can be generalized to produce a wide range of unstable phases which should have more active catalytic properties. To illustrate one rational basis for adopting this method, I point out that the creation of new phases such as Ca_xMn_1-xO₂ would allow testing of two key bioinspired principles of the photosynthetic catalytic site. First, replacement of Mn by Ca, like that adopted by the natural photosynthetic core CaMn₄O_4, should lower the barrier to O-O bond formation by elimination of the directional bonding requirements of the replaced Mn ions (d orbitals require ~90° bonds, while Ca has no such restrictions). Second, replacement of Mn⁴⁺ by Ca²⁺ will require compensating vacancies or oxidation of the oxide sublattice, giving rise to sites that chemically favor the production of O₂.

II. Biosolar Fuels Production (AFOSR, DOE-GTL). Our key achievements thus far include http://www.princeton.edu/~biosolar/: 1) development of the strongest fermentative H₂ producing cyanobacterium and conditions for "milking" to enhance the yield and rate of H₂ production, 2) construction of genetic knock-outs of metabolic pathways with improved fuel production, 3) metabolomics (LC-tandem-MS and cryoprobe-assisted NMR methods) for metabolic pathway elucidation from cellular metabolites, 4) acceleration of fermentation via environmental stresses, 5) optimization of yield via photoautotrophic growth/fermentation conditioning, 6) strain selection & bioprospecting.

All oxygenic phototrophs extract electrons and protons from water and use them to reduce NADP⁺ and plastoquinone for use as energy sources for metabolism such as CO₂ fixation via the Calvin cycle and other pathways. However, some microbial oxygenic phototrophs (cyanobacteria and microalgae) can transiently produce H₂ gas under anaerobic conditions via proton reduction catalyzed by a hydrogenase in competition with other intracellular processes. They do so by redirecting the electrons and protons obtained from reoxidation of carbohydrate storage intermediates at the level of ferredoxin/NADPH into hydrogenase. The carbohydrate intermediate is ultimately produced from CO₂, water and sunlight during photosynthesis. Other phototrophs such as green algae and diatoms store a greater fraction of their carbon fixation intermediates as neutral lipids and thus are better candidates for hydrocarbon or biodiesel production.

Biohydrogen. We are engaged in metabolic engineering to control the flux of electrons and protons into H₂ and lipid production in genetically tractable strains of cyanobacteria, microalgae and diatoms. Our research has identified the metabolic pathways for intracellular reductants and protons to produce H₂ within cyanobacteria. Cyanobacteria use a pathway that is distinct from that used by the microalgae, thus affording new opportunities for enhanced solar H₂ production from water. This distinction enables temporal separation of H₂ from photosynthetic O₂ production, a requirement for applications in energy generation. Large increases in H₂ production have been demonstrated using selective environmental stresses (osmotic pressure, ion exchange, selective nutrient deprivation -nitrate, carbonate and phosphate) and biosynthesis optimization (Ni²⁺ loading) that have practical utility (Ananyev, et al 2008); Carrieri et al. 2008.

Metabolic Engineering. Experimental observations of intracellular reductant accumulation (fluorescence of NADH) have shown that the availability of reducing equivalents (NADH) produced during fermentation of carbohydrate storage molecules (glycogen and osmolytes) limits H₂ production capacity in some cyanobacteria (Ananyev et al., 2008). We therefore initiated studies of fermentative metabolite production in aquatic phototrophs (Carrieri et al, 2008; 2009). To test our hypotheses we have created genetic knock-outs of pyruvate metabolism by antibiotic resistance cartridge mutagenesis; specifically the genes for lactate dehydrogenase and pyruvate-ferredoxin oxidoreductase in Synechococcus 7002 (McNeely, et al. 2009) These mutant strains have substantially increased H₂ production (up to 5 fold). This genetic approach enables the design of tailored made microbes suitable for improved H₂ production and can be applied to other fuel precursors. Extension of this genetic approach to engineering of other cyanobacteria with more robust H₂ production capacity is underway.

GeneticTransformation. My lab is working to transform the filamentous strain Arthrospira (Spirulina) maxima,the most vigorous H₂ producing cyanobacterium. The whole genome was recently sequenced at DOE-JGI based on a grant proposal I submitted with our collaborator Donald Bryant. The strategy that my lab is exploring in collaboration with Oliver Lenz (Humboldt University) is to inactivate the natural restriction enzyme systems in this organism which serve to digest foreign DNA taken up from exogenous sources. The Arthrospira genome contains 11 different restriction systems, including Spal, SpdII, SpaIII and SpaIV, which are isoschizomers of Tth111I, PvuI, PvuII and HindIII (Tagut et al., J.Appl Phycol. 1995, 7, 561-4; Zhao Physiol Genomics 24:181-190, 2006). To protect native DNA from self-digestion the cell uses methylation of selective sites to block the restriction enzymes. The CpG methyltransferase, M.SssI, methylates all cytosine residues (C5) within the double-stranded dinucleotide recognition sequence 5'...CG...3'. This enzyme is available as a commercial kit and is being used to methylate four plasmids that we have constructed for modification of the hox H subunit of hydrogenase. Transformation of the genome using these protected plasmids is underway.

Lipds/Biodiesel. Recently we began working on a new project to examine green microalgae and diatoms as more efficient sources for accumulating neutral lipids as primary energy storage molecules. As part of our bioprospecting efforts, we have discovered several strong lipid producing strains of diatoms from acidic thermal sources which are promising as biodiesel precursors (Figure).

Figure. False-colored image of diatom cell isolated from Norris Hot Spring (YNP): left: bright field microscopy, length 35 mm; right: (red) Chlorophyll fluorescence in the range 670-690 nm, and (green) Nile Red fluorescence in the range 570-620 nm Green light (520-550 nm) used for fluorescence excitation of Chl and Nile Red.

This bioprospecting effort is complemented by collaborative studies with the Falkowski lab (Rutgers Univ.) of lipid metabolism using two marine diatoms strains with sequenced genomes that are genetically transformable: Thalassiosira pseudonana and Phaeodactylum tricornutum. Our goal is to elucidate the pathways for lipid production using the special tools we have developed coupled with knock-out mutagenesis to test hypotheses for metabolic pathways involved. For example, using our ultrasensitive H₂ electrode we recently learned that both diatoms exhibit dark anaerobic H₂ production (autofermentation) and photo-induced H₂. Tp is predicted to have the hydA gene coding for an FeFe-hydrogenase homologous to the Thermatoga enzyme, but no hyd maturase genes. Thus, this appears to be a unique construct capable of assembly even without maturases. Pt is predicted to have no hydrogenase genes at all (no hyd structural genes nor hyd maturases!, but does have a NARF like sequence encoding a type of ironsulfur cluster. Neither possesses nitrogenase genes. The latter discovery suggests that we have identified a new H₂ evolving system not previously known in biology.

Bioprospecting for Water-Splitting Enzymes: The Search for Photosynthetic "Weirdophiles": (NIH, Dreyfus, AFOSR). We are searching for novel oxygenic phototrophs that split water using unconventional mechanisms distinct from that typified by terrestrial plants. We call these "weirdophiles" to distinguish them from most extremophiles which merely use tuned versions of conventional enzymes and standard mechanisms. Our first "weirdophile" is an alkalophillic cyanobacterium isolated from alkaline soda lakes of E. Africa (pH >10 carbonate ~0.4 M). Using homebuilt tools for in vivo measurements of PSII activity we have discovered that cells of Arthrospira m. have a 5x faster turnover rate of the O₂-evolving complex (OEC) compared to all other phototrophs examined thus far (Ananyev and Dismukes, 2005). This organism uses carbonate directly in the OEC for water splitting, possibly as a proton acceptor (Carrieri, et al., 2007). Other unusual aquatic phototrophs are under study which may have the potential to replace carbonate by borate.

Instrumentation Development for Renewable Energy Science (NSF-IDBR, NASA-NAI, AFOSR) Important discoveries are often made by those with the best tools. We have designed and built several powerful instruments that offer major advantages for detection of dissolved O₂ and H₂ gases, intracellular fluorescence detection of pigments and pyridine nucleotides, and magnetic resonance. These tools are being applied to projects in photobiology, photochemistry and geomicrobiology.

Detection of Dissolved Hydrogen. In another approach we are developing ultrasensitive tools for screening for microbial hydrogen production activity from diverse natural habitats. Strains isolated from these screens have been shown to possess better metabolic properties more suited for large scale H₂ production. This strategy has identified novel strains from volcanic soda lakes, thermophillic sources and hypersaline aquifers. Data from one of the three powerful tools that we have built is illustrated in the figure, showing detection of dissolved H₂ (at 10^-8 M sensitivity) produced by induction of hydrogenase activity in the green microalga, Chlamydomonas reinhardtii. The figure illustrates how trains of light pulses of variable pulse duration give rise to different kinetics of H₂ production. At higher light duration, more O₂ is produced which poisons the hydrogenase enzyme thereby suppressing H₂ production. This behavior differs among individual strains and between different species.

Detection of Intracellular NADH+NADPH by Fluorescence. These cofactors are believed to serve as the sole reductants for the hox-class of bidirectional NiFe-hydrogenases. This claim has been inferred almost entirely from in vitro assays. However, there is no direct evidence identifying the cognate reductants for hydrogenase in vivo. Moreover, there is ambiguity in the literature on whether NADH or NADPH or both can serve as reductant for the same hydrogenase in some species. To examine these issues with greater precision, we have constructed an instrument for detection of intracellular fluorescence emission produced by reduced pyridine nucleotide cofactors (total NADH+NADPH) (see Fig.). This instrument includes a second channel for simultaneous electrochemical detection of dissolved H₂ using our homebuilt design (2 nanomolar sensitivity). Completed in May 2007, this unique instrument is providing a wealth of new information about intracellular redox regulation
via pyridine nucleotides.

Detection of Charge Separation by Fluorescence. Once of these instruments is a fast-repetition rate laser-based fluorometer that has the capability of measuring the speed and error frequency of photochemical turnover of the PSII O₂-evolving complex (OEC) (Ananyev and Dismukes, 2005). The instrument has increased by 100 fold the range of flash excitation rates previously examined using oximetry and allows measurements on intact cells and leaves, samples previously inaccessible without perturbation. With this tool we have been able to characterize the efficiency of PSII-OEC turnover over its full range of turnover frequencies using intact cells and leaves without the need to isolate the PSII enzymes. Fitting of the data to kinetic models for PSII turnover have revealed new control features of the OEC.

Awards

• 1969, 70, 71 Top chemistry student award Lowell Technological Institute & BS with high honors
• 1971 American Institute of Chemistry Outstanding Senior Award, New England Chapter
• 1972-75 DOE Predoctoral Scholarship, University of Wisconsin
• 1975 Sigma Xi Graduate Research Award, University of Wisconsin
• 1975-78 DOE Postdoctoral Fellowship Lab. of Chemical Biodynamics, University of California
• 1979 DuPont Young Faculty Award
• 1981-83 G. D. Searle Scholars Award
• 1983 Monbusho Visiting Lectureship (Japan's Ministry of Education) RIKEN Symposium
• 1984-86 Alfred P. Sloane Award
• 1987 Monbusho Visiting Lectureship (Japan's Ministry of Education) NIBB, Okazaki
• 1984 Visiting Research Fellowship, Service de Biophysique Departement de Biologie, CEN-Saclay
• 1991 Squibb Institute Fellowship, Visiting Research Scientist
• 1992 Japan Society for the Promotion of Science Distinguished Visiting Fellowship Kyoto University
• 1992 National Research Council Fellowship
• 1997 CNRS Distinguished Visiting Fellow Universite Joseph Fourier, Grenoble France
• 1997 NRSA Fogarty International Fellow
• 1997 Japan Society for the Promotion of Science Distinguished Visiting Fellow Kansai-Gaikun Univ.
• 2004 Lemberg Award, Australian Academy of Sciences
• 2008 Chinese Bioenergy Association Award, Chinese Academy of Sciences

Selected Honors & National/International Service, 2004-

• 2010 Plenary lecturer, International Hydrogenase Conference, Uppsala, Sweden, convenor: Peter Lindblad.
• 2009 Board of advisors to the filming of the second annual Zayed Future Energy Prize in Abu Dhabi (www.zayedfutureenergyprize.com) Filmaker Director/Producer: Tina DiFeliciantonio, Naked Eye Productions Ltd
• 2009 Symposium Organizer, Solar Biofuels, AICHe National Meeting, Memphis TN, Nov 12, 2009, Convenor: Winston Ho & Bond Calloway.
• 2009 Speaker, Workshop on Algal Biofuels, Los Alamos National Laboratory, Albuquerque, NM, July 8-10. Organizer: Jose Oliveras.
• 2009 Speaker, AFOSR-MURI Program Review, Algal Biofuels Workshop, Arlington, VA, August 18-19. Organizer: Walter Kozumbo.
• 2009 Plenary lecturer, "Dahlem Conference" ENERGY: THE MAGIC TRIANGLE BETWEEN SCIENCE TECHNOLOGY AND POLITICS. Germany, Organizers: R. Schlogel, F. Schuth, R. Bittl. http://www.fu-berlin.de/veranstaltungen/dahlemkonferenzen/en/index.html
• 2009 Plenary lecturer, 29th "Energy for the 21st Century", Annual Conference of the Center for Nonlinear Studies (CNLS), Los Alamos National Laboratory, May 18-22. convenor: S. Gnanakaran and Robert Ecke.
• 2009 co-organizer, AFOSR Algal Biofuels Workshop on Microbial Metabolism for Hydrogen and Biodiesel Production, NREL, Golden, CO, Jan 8-9.
• 2008 Plenary lecturer, Int. Conference on Biomass Energy Technologies, Chinese Bioenergy Association, Guangzhou, China , 3-5 Dec., convenor: Prof. Chuangzhi Wu and Xin-shu Zhuang.
• 2008 Lecture, State Key Laboratory for Clean Energy Utilization, Hangzhou, China, 7-10 Dec. convenor: Dr. Kefa Cen.
• 2008 Invited participant, National Algal Biofuels Technology Roadmap Workshop, DOE, MD, Dec 8-11, convenor: Jacques Beaudry-Losique , schedule conflict.
• 2008 Invited Participant, Dreyfus Energy and the Environment Symposium, Dreyfus Foundation, New York Academy of Sciences, NY City, Oct. 24. convenor: Mark Cardillo.
• 2008 Lecturer, Rutgers University, Plant Physiology Dept. host: Todd Michaels.
• 2008 Panelist, New Jersey Hydrogen Learning Center Workshop, Center for Energy, Economic & Environmental Policy Rutgers University, Bloustein Center, New Brunswick, NJ. October 9. convenor: Frank Felder.
• 2008 Lecturer, (MACCCR) NIST FUELS RESEARCH REVIEW, Gaithersburg MD, 8-10 September; Convenor: Julian Tishkoff.
• 2008 Plenary lecturer, ZIF International bioenergy symposium "SolarBioFuels", Center for Biotechnology, University of Bielefeld, Germany, August 12-14, Convener: Olaf Kruse
• 2008 Lecturer, AFOSR BioFuels Program Review, Aug 5-6, Convenor: Walter Kozumbo.
• 2008 Lecturer/Advisor to National Renewable Energy Laboratory (NREL) and Air Force Office of Scientific Research (AFOSR) workshop on Microalgal Lipid to Biofuels, February 19-21, 2008 Arlington, VA.
• 2008 Lecturer, PRISM-Industrial Research Symposium, Materials for Energy. Princeton, NJ, Marth19th-20th, 2008.
• 2008 Plenary lecturer, ESF-EMBO Symposium on "Molecular Bioenergetics of Cyanobacteria: Towards Systems Biology Level of Understanding", Sant Feliu de Guixols, Spain, 29 March - 3 April; Convener: Eva Mari Aro.
• 2008 Lecturer, Utah State University, Dept of Chemistry, schedule conflict, host L. Seefeldt.
• 2007 Plenary lecturer, National ACS Meeting, Presidential Symposium: "Realizing the Full Potential of Solar Energy Conversion through Basic Research in Chemistry and Biochemistry", Chicago, Convener: Arthur Nozik, March 25-29,
• 2007 Reviewer, German BMBF (Federal ministry of education and research) on "Biohydrogen", Berlin, Feb. 21-23. Schedule conflict.
• 2007 Plenary lecturer/workshop report, Royal Society Discussion "Revealing how Nature uses sunlight to split water", London , UK, Convener: James Barber, April 23-24.
• 2007 Lecturer/member workshop report, National Academy of Sciences, "Workshop on Bio-Inspired Chemistry for Energy", Convener, Douglas Ray, May 14-15,
• 2007 Plenary lecturer, International Hydrogenase Conference, Breckenridge, CO, Convenors: M Dahrensburg and M. Ghirardi, August 5-10.
• 2007 Symposium lecture, AFOSR Conference on Biological Hydrogen Production from Water and Light, Colorado School of Mines/National Renewable Energy Lab, Golden, CO, Convener: Matthew Posewitz, August 11.
• 2006 Conference Chair, Biological Hydrogen Production from Water and Light: Current Status & Future Prospects, Sponsored by the US Air Force Office of Scientific Research; Princeton, July.
• 2006 lecturer, CCNY, Dept. of Biochemistry, Bronx NY, August
• 2006 lecturer, Harvard University, Div. Engineering & Applied Sciences, Cambridge, MA, October.
• 2006 lecturer, American Chemical Society, Princeton Chapter, NJ, November.
• 2006 lecturer, Technology Transfer Goes Green: Better Business for a Better Tomorrow, Kean University, Union, New Jersey, November
• 2006 IGERT lecturer (graduate student invitation), Arizona State University, February.
• 2006 Plenary lecturer, BIO: Pacific Rim Summit on Industrial Biotechnology and Bioenergy, Honolulu, HI, Jan
• 2006 Plenary lecturer, Eastern Regional Photosynthesis Conference, Marine Biological Laboratory, Woods Hole, MA, April.
• 2006 Duke University, Nicholas School for the Environment, Durham, NC, April
• 2006 Purdue University, Energy Center, W. Lafayette, IN, May
• 2006 Gordon Research Conf. Photosynthesis, Biohydrogen Session Chair, Bryant Univ. R. I., July.
• 2006 Stanford University, Global Climate & Energy Project, Stanford, CA, , July
• 2005 Conference Chair, Biological Hydrogen Production from Water and Light: Current Status & Future Prospects, Sponsored by the US Air Force Office of Scientific Research; Princeton, June.
• 2005 Program Organizing Committee NASA Astrobiology Institute Biennial Meeting http://nai.nasa.gov/nai2005/
• 2005 Symposium Lecture: The Human Frontiers Science Program 5^th Annual Awardees Meeting, Bethesda, MD June 5-8.
• 2005 Director of multi-institutional BioSolarH2 team, AFOSR-MURI; http://www.princeton.edu/~biosolar/
• 2004 Advisor to NSF-GETF: Advanced Renewable Hydrogen Production Working Group. (organizer Helena Chum, DOE-BES) June.
• 2004 Symposium Lecture: International Satellite Meeting: Photosynthesis and Post-Genomic ERA, Trois-Rivieres, Quebec Canada, Convener: R. Carpentier, 25-28 August.
• 2004 Symposium Lecture: International Congress on Photobiology and Photochemistry, Jeju, So. Korea, June 10-15.
• 2004 Lemberg Lecture Series, Australian Academy of Sciences, 15 - 24 June: University of Queensland, University of Sydney, University of Melbourne, Monash University, Public Lectures: Australian National University, Canberra & CSIRO-Melbourne.
• 2004 Reed College, Dept of Chemistry, February
• 2004 NASA Astrobiology Institute, IPTAI Workshop, Jan. "Biosustainable Energy and Nutrient Cycles in the Deep Subsurface of Earth and Mars"
• 2004 EUROBIC 7 Garmisch-Partenkirchen Germany. Organizer: Prof. Bernhard Lippert. (declined, scheduling conflict)
• 2004 SABIC; S. Mazumder convenor; India (schedule conflict) Dec 5-10
• 2003 Advisor/Plenary Lecturer to the US DOE-BES Workshop on Hydrogen Production Technologies: roadmap report on "Basic Research for Hydrogen Production, Storage and Use" (organizer Mildred Dreselhauser) Symposium chairs: T. Mallouk and L. Mets; June.

Patents

1. Dismukes, G.C. and Ruettinger,.W. F. Mn4O4-cubane type catalysts. 2001, United States Patent: 6,316,653.
2. Dismukes, G. C. & Ruettinger, W. F. Mn4O4 Cubane Type Catalysts, Divisional to US Patent 6,316,653, Oct 12, 2004.
3. Brimblecombe, R., Spiccia, L., Dismukes, G.C., Swiegers, G.F., WATER OXIDATION CATALYSTS. US Provisional Patent 30195044, filed March 27, 2007.
4. Brimblecombe, R., Spiccia, L., Dismukes, G.C., Swiegers, G.F., "Membranes and Photoelectrochemical Devices for Carbon-Neutral Renewable Hydrogen Generation from Water", US Provisional Patent ##, filed March 27, 2008.

Publications

1. Derrick R. J. Kolling, Tyler S. Brown, Gennady Ananyev, G. Charles Dismukes, Photosynthesis under high oxygen pressure: Sites of oxygen action and relevance to biogeochemical evolution. In preparation.
2. Damian Carrieri, Dariya Momot, Gennady Ananyev, and G. Charles Dismukes. "Osmotic stress offers a new strategy for increasing fermentative product yields from the halophilic, alkalonphilic cyanobacterium Arthrospira (Spriulina) maxima", Applied Environmental Microbiology, Submitted.
3. Nicholas Cox, Derrick R. J. Kolling, Gennady M. Ananyev, Ron J. Pace, G. Charles Dismukes. "What Oxidation States if Required to Oxidize Water during Photosynthesis: Counting the Redox Equivalents Needed to Produce Photosynthetic Oxygen", In preparation.
4. DISMUKES, G. C., R. BRIMBLECOMBE, G.A.N. FELTOn, R.S. PRYADUN, J.E. SHEATS, L. SPICCIA, and G.F. SWIEGERS, Development of Bioinspired Mn₄O₄-Cubane Water Oxidation Catalysts: Lessons from Photosynthesis. Accounts of Chemical Research, 2009. submitted.
5. Kelsey McNeely, Yu Xu, Gennady Ananyev, Donald A. Bryant, G. Charles Dismukes, "Genetic Redistribution of Carbon Metabolism and Its Application to Solar Hydrogen Production in Synechococcus sp. 7002" , Proc. Nat. Acad. Sci. USA, in review.
6. Damian Carrieri, Istvan Pelczer, Gennady Ananyev, Oliver Lenz, Donald A. Bryant, and G. Charles Dismukes, "Accelerating Autofermentative Metabolism to Produce Desired Carbon Metabolites and Hydrogen via Na⁺ à K⁺ Ion Stress". Applied Environmental Microbiology, submitted
7. Dasgupta, J., A.M. Tyryshkin, S.V. Baranov, and G. C. Dismukes, A Role for (Bi)carbonate in Assembly of the Mn4Ca Cluster of Photosystem II Revealed by EPR Spectroscopy: Ligand Field and 55Mn Hyperfine of Mn3+. Applied Magnetic Resonance, Springer, editor: K. Mobius, special issue honoring Wolfgang Lubitz, in press.
8. Damian Carrieri, Kelsey McNeely, Ana C De Roo, Nicholas Bennette, István Pelczer, and G. Charles Dismukes "Identification and quantification of water-soluble metabolites by cryoprobe-assisted nuclear magnetic resonance spectroscopy applied to microbial fermentation." Magn. Reson. Chem. 2009, 47, in press. (www.interscience.com) DOI 10.1002/mrc.2420
9. Swiegers, G.F., J. Huang, R. Brimblecombe, J. Chen, G. C. Dismukes, U.T. Mueller-Westerhoff, L. Spiccia, and G.G. Wallace, Homogeneous catalysts with a mechanical ("machine-like") action. Chemistry: A European Journal, 2009. 15(19): p. 4746-59.
10. Jonathan E. Meuser, Gennady Ananyev, Lauren E. Wittig, Sergey Kosourov, Maria L. Ghirardi, Michael Seibert, G. Charles Dismukes and Matthew C. Posewitz. Phenotypic Diversity of Hydrogen Production in Chlorophycean Algae Reflects Distinct Anaerobic Metabolisms, J. Biotechnology, 2009, 142:21-30.
11. Brimblecombe, R., A.M. Bond, G. C. Dismukes, G.F. Swiegers, and L. Spiccia, Electrochemical Investigation of Mn4O4-Cubane Water Oxidizing Clusters. Physical Chem Chem Physics, 2009. 11: p. 6441-6449.
    Lessons from Photosynthesis, is now available on the Accounts of Chemical Research website.
12. Brimblecombe, R., D.R.J. Kolling, A.M. Bond, G. C. Dismukes, G.F. Swiegers, and L. Spiccia, Sustained Water Oxidation by [Mn4O4]7þ Core Complexes Inspired by Oxygenic Photosynthesis. Inorg. Chem. 2009. 48, 7269-7279.
13. Brimblecombe, R., M. Rotstein, A. Koo, G. C. Dismukes, G.F. Swiegers, and L. Spiccia, A bio-inspired molecular water oxidation catalyst for renewable hydrogen generation: An examination of salt effects, Proc. of SPIE, 2009. 7408: p. V1-V8; doi:10.1117/12, .824840. http://spiedigitallibrary.org/getabs/servlet/GetabsServlet?prog=normal&id=PSISDG00740800000174080V000001&idtype=cvips&gifs=Yes&bproc=symp&scode=OP09S
14. Derrick R. J. Kolling, Tyler S. Brown, Gennady Ananyev, G. Charles Dismukes, Photosynthetic O₂ evolution is not reversed at elevated O₂ pressures: mechanistic consequences for water oxidation. Biochemistry 2009, 48 (6), 1381-1389.
15. Ananyev G., Carrieri D., and G. C. Dismukes, "Optimization of metabolic capacity and flux through environmental cues to maximize hydrogen production by the cyanobacterium "Arthrospira (Spirulina) maxima", Applied Environmental Microbiology, 2008, 74, 19, p. 6102-6113.
16. Brimblecombe, R., G. C. Dismukes, G.A. Felton, L. Spiccia, and G.F. Swiegers, Time-dependent ("Mechanical"), Nonbiological Catalysis. 1. A Fully Functional Mimic of the Water-Oxidizing Center in Photosystem II, in Mechanical Catalysis: Methods of Enzymatic, Homnogeneous, and Heterogeneous Catalysis, S. G.F., Editor. 2008, Wiley-Blackwell: New York.
17. Carlo Sbraccia; Morrel H. Cohen; Roberto Car; G. Charles Dismukes, Annabella Selloni, Mechanisms of H₂ Production by the [FeFe]_H-Subcluster of Di-iron Hydrogenases: implications for abiotic catalysts. J. Physical Chem. 2008, 112:13381-13390.
18. Robin Brimblecombe, Gerhard F. Swiegers, G. Charles Dismukes, Leone Spiccia, Sustained Water Oxidation Catalysis by a Bioinspired Molecular Cluster, Angew. Chemie Int. 2008, 47, (38), 7335-8.
19. Dismukes GC, Carrieri D, Bennette N, Ananyev GM, Posewitz MC: Aquatic phototrophs: efficient alternatives to land-based crops for biofuels. Current Opinions Biotechnology 2008, 19: 235-240.
20. Carrieri D. Ananyev G., and G. C. Dismukes, Renewable hydrogen production by cyanobacteria: nickel requirements for optimal hydrogenase activity. International Journal of Hydrogen Energy. 33 (2008) 2014 - 2022.
21. John E. Bartlett, Sergei V. Baranov, Gennady M. Ananyev, G. Charles Dismukes "Calcium Controls the Assembly of the Photosynthetic Water-Oxidizing Complex: A Cadmium(II) Inorganic Mutant of the Mn₄Ca Core" Phil Trans R Soc London A, 363 (2008) 1253-1261.
22. Damian Carrieri, Gennady Ananyev, Tyler Brown, G. Charles Dismukes , In vivo bicarbonate requirement for water oxidation by Photosystem II in the hypercarbonate-requiring cyanobacterium Arthrospira maxima. J. Inorganic Biochemistry 101 (2007) 1865-1874.
23. J. Dasgupta, A. M. Tyryshkin, and G. C. Dismukes, ESEEM Spectroscopy Reveals Carbonate and a N-Donor Protein-Ligand Binding to Mn2+ in the Photoassembly Reaction of the Mn4Ca Cluster in Photosystem II. Angewandte Chemie Int. 2007, 46, 8028 -8031.
24. Jyotishman Dasgupta, Gennady M. Ananyev, G. Charles Dismukes, Photoassembly of the water-oxidizing complex in photosystem II. . Coordination Chemistry Reviews 252 (2008) issue 3-4, 347-360. http://www.elsevier.com/wps/find/journaldescription.cws_home/500845/description#description
25. Milligan, A.J., I. Berman-Frank, Y. Gerchman, G. C. Dismukes, and P.G. Falkowski, Mehler activity in nitrogen fixing cyanobacteria: A key role in oxygen consumption. Journal of Phycology, 43, (2007) Issue 5, 845-852.
26. Ying Yu, Manish Dubey, Steven L. Bernasek and G. Charles Dismukes, Self-assembed monolayer of organic iodine on Au surface for attachment of water oxidation catalysts. Langmuir 2007, 23, 8257-8263.
27. Tyryshkin, A.M., R.K. Watt, S.V. Baranov, J. DasGupta, and G. C. Dismukes, Ca2+ Directs the Assembly of the Mn¬4Ca Cluster in the Photosynthetic Water Oxidizing Complex: Formation of a Ligand Bridge to Mn3+ via Deprotonation. Biochemistry 2006; 45(42); 12876-12889.
28. Rupprecht, J., B. Hankamer, J.H. Mussgnug, G. Ananyev, D. G. C., and O. Kruse, Perspectives and advances of biological H2 production in microorganisms. Applied Microbiology and Biotechnology, 2006. 72, 442-449.
29. Carrieri, D., D. Kolling, G. Ananyev, and G. C. Dismukes, Prospecting for biohydrogen fuel. Industrial Biotechnology, 2006. 2(2), 133-137.
30. Wu, J.-Z., F.D. Angelis, T.G. Carrell, G.P.A. Yap, J. Sheats, R. Car, and G. C. Dismukes, Tuning the photo-induced O2-evolving reactivity of Mn4O46+ and Mn4O47+ manganese-oxo cubane complexes. Inorganic Chemistry, 2006. 45(1): p. 189-195.
31. Dasgupta J, Tyryshkin AM, Kozlov YN, Klimov VV, and D. GC., Carbonate complexation of Mn2+ in the aqueous phase: redox behavior and ligand binding modes by electrochemistry and EPR spectroscopy. J Phys Chem B, 2006. 110(10): p. 5099-111.
32. Hillier, W., I. McConnell, M.R. Badger, A. Boussac, V.V. Klimov, G. C. Dismukes, and T. Wydrzynski, Quantitative Assessment of Intrinsic Carbonic Anhydrase Activity and the Capacity for Bicarbonate Oxidation in Photosystem II. Biochemistry, 2006. 45(7): p. 2094-102.
33. Kruse, O., J. Rupprecht, J.H. Mussgnug, G. C. Dismukes, and B. Hankamer, (2005) Photosynthesis: A blue print for energy capture and conversion technologies. Photobiological Sciences, 4(12): p. 957 - 970.
34. Ananyev, G., T. Nguyen, C. Putnam-Evans, and G. C. Dismukes, (2005) Mutagenesis of CP43-arginine-357 to serine reveals new evidence for (bi)carbonate functioning in the water oxidizing complex of Photosystem II. Photobiological Sciences, 4(12): p. 991 - 998.
35. Hillier, W., I. McConnell, A. Boussac, J. Messinger, M. Badger, C. Dismukes, and T. Wydrzynski, Substrates of Photosynthetic Water Oxidation, in Photosynthesis: Fundamental Aspects to Global Perspectives, A.van.der.Est and.D. Bruce, Editor. 2005, The International Society of Photosynthesis; ACG Publishing: Lawrence, KS.
36. Berman-Frank, I., Y. Chen, Y. Gerchman, G. Dismukes, and P. Falkowski, Inhibition of nitrogenase by oxygen in marine cyanobacteria controls the global nitrogen and oxygen cycles, in Biogeosciences Discussions. 2005, European Geosciences Union. p. 261-273, SRef-ID: 1810-6285/bgd/2005-2-261. European Geosciences Union.
37. Ananyev, G. M. and G. C. Dismukes (2005). "How Fast Can Photosystem II Split Water? Kinetic Performance at High and Low Frequencies." Photosyn. Res. 84, 355-365
38. Dismukes, G. C. and R.E. Blankenship, The Origin and Evolution of Photosynthetic Oxygen Production, in Photosystem II: The Water/Plastoquinone Oxido-Reductase In Photosynthesis, T. Wydrzynski and K. Satoh, Editors. 2005, Springer, The Netherlands. Ch 30. pp. 683-695.
39. Dismukes, G. C., G.M. Ananyev, and R. Watt, Assembly of the Inorganic Core and "Inorganic Mutants" of the Water Oxidizing Complex, in Photosystem II: The Water/Plastoquinone Oxido-Reductase In Photosynthesis, T. Wydrzynski and K. Satoh, Editors. 2005, Springer, The Netherlands. Ch. 25. PP. 609-626
40. Dismukes, G. C. and R. T. van Willigen (2005). Manganese: The Oxygen-Evolving Complex & Models. Encyclopedia of Inorganic Chemistry II. B. King, J. Wiley.
41. Wu, J.-Z., E. Sellitto, G. P. A. Yap, J. Sheats and G. C. Dismukes (2004). "Trapping An Elusive Intermediate in Manganese-Oxo Cubane Chemistry." Inorg. Chem. 43: 5795-97.
42. Kozlov, Y. N., S. K.Zharmukhamedov, K. G. Tikhonov, J. Dasgupta, A. A. Kazakova, G. C. Dismukes and V. V. Klimov (2004). "Oxidation potentials and electron donation to photosystem II of manganese complexes containing bicarbonate and carboxylate ligands." Physical Chemistry: Chemical Physics 6: 4905-4911.
43. Dasgupta, J., R. T. v. Willigen and G. C. Dismukes (2004). "Consequences of structural and biophysical studies for the molecular mechanism of photosynthetic oxygen evolution: functional roles for calcium and bicarbonate." Physical Chemistry: Chemical Physics 6: 4793-4802.
44. Baranov, S., A. M. Tyryshkin, D. Katz, G. M. Ananyev, V. V. Klimov, G. C. Dismukes., Bicarbonate is a Native Cofactor for Assembly of the Manganese Cluster of the Photosynthetic Water Oxidizing Complex: II. Kinetics of Reconstitution of O2 Evolution by Photoactivation. Biochemistry, 2004. 43: 2070-2079.

Book Reviews

1. G. C. Dismukes, in Coordination Chemistry Reviews, Ed. for A. B. S. Lever., (1993).
2. G. M. Ananyev, L. Zaltsman, and G. C. Dismukes, "Assembly of the Inorganic Core of the Photosynthetic Water Oxidizing Complex and "Inorganic Mutants". 25th Steenbock Symposium. (1997).
3. G. C. Dismukes, in Angew. Chem. Int. Ed. 2002, 41, No. 9.