The WALKER Laboratory
	Dr. Larry P. Walker Professor Dept of Biological and Environmental Engineering 232 Riley-Robb Hall Cornell University Ithaca, NY 14853 Phone: 607-255-2478 Fax: 607-255-4080 Email:lpw1@cornell.edu Graduate Fields: Agricultural and Biological Engineering Chemical and Bio-molecular Engineering The Biofuels Research Laboratory (BRL): A Launch Pad for Scientific and Technological Innovations (under construction, expected completion January 2009)

Biography

I am a native of Detroit, Michigan and a graduate of Michigan State University with a B.S. in Physics. My interests in renewable resources and environment research led me to complete M.S. and Ph.D. degrees at Michigan State University in Agricultural Engineering. I joined the Cornell Faculty in 1979 to work in renewable energy research with a specific focus on biomass conversion to energy.

Some Extramural Activities

• Director, Northeast Sun Grant Initiative
• Member, Advisory Board, Presidential Forum on Renewable Energy
• Member, American Council On Renewable Energy (ACORE), Higher Education Committee (HEC)’s Steering Committee
• Member, Executive Committee, Cornell Nanobiotechnology Center
• Co-Editor In Chief, Industrial Biotechnology
• Project Director, New York State Office of Science, Technology and Academic Research (NYSTAR) Faculty Development Program Award
• Member, Kavli Inst. at Cornell for Nanoscale Science (KIC)

Research and Teaching Activities

My research and teaching activities are focused on bioprocessing engineering and the development of sustainable agricultural-based bioindustries. I am currently teaching the following two courses:

• BEE 787 - Industrial Ecology of Agriculturally-Based Bioindustries: This is a system modeling and analysis course focused on interconnecting discrete physical, chemical and biological processes to create novel industrial ecologies. An input/output modeling methodology is employed to develop and manipulate the structure of complex agricultural-based bioindustries and to generate the material, energy and monetary flows.
• BEE 788 - Biomass Conversion for Energy and Chemicals: This course is designed to introduce students to biological and physical conversion of biomass to bioenergy and industrial chemicals. The course will explore the biological and engineering concepts associated with microbial and enzymatic conversion of biomass to useful products, and introduce students to the physical and chemical processes associated with the pretreatment of biomass and the separation of key biomolecules.

Currently my research interests can be grouped into four categories:

Single Molecular detection and analysis method to the challenge of elucidating hydrolytic and synergistic mechanisms of cellulases acting on microcrystalline cellulose.

Modeling, analysis and optimization of solid-state fermentation processes for the production of natural products.

Modeling and optimization of submerged fermentation processes for the production of enzymes and other products.

Single molecule detection and nano-fabricated devices for use in molecular ecology studies of microbial community in high-solids degradation processes.

My research activities are inherently multidisciplinary involving researchers from Applied and Engineering Physics, Civil and Environmental Engineering, Molecular Biology and Genetics, Microbiology, Plant Pathology and Plant Biology.

Research Team

	Stephané Corgié, Ph.D., Research Associate My research at Cornell University concerns the design of new molecular reactions and nano-devices (collaboration with the Craighead Research Group) for the description of microbial communities involved in relevant bio-processes. Microbes in environments are numerous and diversified, and we are far from having completed their inventory, as it is estimated that less than 5% of bacterial species have been yet discovered. We believe that nano-technologies (lab-on-a-chip hardware) would provide a tremendous insight (accuracy and high input screening) for the understanding of microbial biocomplexity and functioning.
	Marie Donnelly , M.S./Ph.D. Candidate I am interested in the development of sustainable energy systems from biological sources, in particular the conversion of cellulose to ethanol. My research currently focuses on the use of plant pathogens to degrade cellulose to fermentable sugars for ethanol production in collaboration with researchers from the Plant Science department at Cornell. Following the initial experiments to show cellulose degradation, I plan to measure reaction kinetics under varying conditions using high throughput screening methods being developed in this research group.
	Edward Evans, M.S., Research Support Specialist My work at Cornell focuses on providing a high level of technical and operational lab assistance in the Biomass Conversion Group. My position is responsible for a broad range of research and lab management tasks including, but not limited to, the development of research methods, training, protocol development, and evaluation of data. Currently my main focus evolves around the operation and maintenance of bioreactors and analytical equipment while assisting with the overall efficiencies and organization of the Walker lab. My future goal evolves around acceptance into Cornell’s Ph.D. program focusing in biomass conversion.
	Linelle Fontenelle, M.S./Ph.D Candidate My area of research involves the solid state fermentation (SSF) of a mixed culture of switchgrass and dog food. SSF may be defined as the growth of microorganisms on moistened solid substrates in the absence of free-flowing water and it is an evolving technology for the production of natural products such as enzymes and bio control agents from biomass. I will initially focus on the kinetic and mass transfer activities during the composting of this solid organic material and later move on to study the microbial communities which correspond to the observed transport phenomena. In particular, I will use a combination of molecular biological methods to determine the predominant phylogenetic groups, their relative abundance and activity within the compost pile.
	Ben Heavner , Ph.D. Candidate My research investigates the potential benefits which may be realized by applying an engineered biological community for bioprocessing, rather than a single organism. To that end, I am working to track subpopulations in mixed communities to investigate topics such as community stability, competition and cooperation between various ethanol producing micro-organisms for mixed sugar sources, and opportunities for increasing ethanol yield and tolerance in mixed-yeast populations.
	Jose Moran-Mirabal, Postdoctoral Research Associate My research concerns the study of cellulase activity at the single molecule level. Through optical techniques, such as fluorescence correlation spectroscopy and total internal reflection florescence microscopy, the fluorescently-labeled cellulases are studied on cellulosic substrates.
	Sarah Munro, M.S./Ph.D. Candidate My research focus is on metabolic engineering of the thermophilic bacterium, Thermotoga neapolitana, which produces hydrogen gas through fermentative pathways. This hydrogen production capability of T. neapolitana makes it an ideal organism for the industrial bioconversion of waste to fuels. Mass balances on small anaerobic batch cultures, scale-up to larger chemostats and metabolic pathway manipulation will be employed to optimize hydrogen gas production.
	Corinne Rutzke, Ph.D., Senior Research Associate My research interest areas include controlled environment agriculture, plant physiology, biomass, photobiology, hydroponics, biomolecular farming, medicinal plants, phytochrome, gravitational plant physiology.
	Aaron Saathoff, Ph.D. Candidate Currently I am studying the cadmium transport properties of Brassica napus, a plant with phytoremediation potential. My work is focusing on modeling the dynamics of cadmium uptake and adsorption using an experimental system specifically designed for this purpose. Additionally, my ongoing work involves the characterization of cadmium transport in the xylem sap of B. napus.
	Navaneetha Santhanam, Ph.D. Candidate My research focuses on tracking the movement of the cellulases of Thermobifida fusca on cellulose. I am using Total Internal Reflection Fluorescence Microscopy for this purpose and I hope to elucidate the mechanism of cellulose hydrolysis by studying binding and hydrolysis phenomenon at the single molecule level.

Selected Publications

Santhanam, N. and Walker, L. P.  2008.  A  High-Throughput Assay to Measure Cellulase Binding  and Synergism in Ternary Mixtures.  ASABE Biological Engineering Journal, 1(1):1-19.

Pryor, S. W., Siebert, K. J., Gibson, D. M., Gossett, J. M. and Walker, L. P.   2007. Modeling Production of Antifungal Compound and their Role in Biocontrol Product Inhibitory Activity.  J. Agric. Food Chem., 55:9530-9536.

Walker, L.P.  2007.  Nanobiotechnology as an Enabler for Biofuels Research and Development.  The New York Academy of Sciences eBriefings, The 8^th Annual Nanobiotechnology Symposium, Cornell University, Ithaca, NY.  www.nyas.org/nbtc8.

Krause, E.L., Villa-Garcia, M.J., Henry, S.A. and Walker, L.P. 2007. Determining the Effects of Inositol Supplementation and the opi1 Mutation on Ethanol Tolerance of Saccharomyces cerevisiae. Industrial Biotechnology, 3(3):260-268.

Stavis, S. M., Corgié, S. C., Cipriany, B. R., Craighead_, H. G. and Walker L. P. 2007. Single Molecule Analysis of Bacterial PCR Products in Submicrometer Fluidic Channels. Biomicrofluidics, 1:1-13.

Pryor, S. W., Gibson, D. M., Hay, A. G., Gossett, J. M. and Walker, L. P. 2007. Optimization of Spore and Antifungal Lipopeptide Production during the Solid State Fermentation of Bacillus subtilis. Appl. Biochem. Biotechnol. 143:63-79.

Yu, L-X, Gray, B. N., Rutzke, C. J., Walker, L. P., Wilson, D. and Hanson. M. 2007. Expression of Thermostable Microbial Cellulases in the Chloroplasts of Nicotine-Free Tobacco. J. Biotechnology, 131:362-369

Pryor, S. W., Gibson, D. M., Bergstrom, G. C., and Walker, L. P. 2007. Minimization of Between-well Sample Variance of Antifungal Activity Measurements Using a High-Throughput Screening Microplate Bioassay. BioTechniques: 42: 151-156.

Pryor, S. W., Gibson, D. M., Krasnoff, S. B., and Walker, L. P. 2006. Identification of Antifungal Compounds in a Biological Control Product Using a Microplate Inhibition Bioassay. Trans. ASAE, 49: 1643-1649.

Jeoh, T., Wilson, D. B. and Walker, L. P. 2006. Effect of Cellulase Mole Fraction and Cellulose Recalcitrance on Synergism in Cellulose Hydrolysis and Binding. Biotechnology Progress, 22: 270-277.

Richards, T. L., Walker, L. P., and Gossett, J. M. 2006. Modeling the Temperature Kinetics of Aerobic Solid-State Biodegradation. Biotechnology Progress, 22: 70-77.

Richards, T. L., Walker, L. P., and Gossett, J. M. 2006. Effect of oxygen on aerobic solid-state biodegradation kinetics. Biotechnology Progress, 22: 60-69.

Kephart, K.D., Rutzke, C.J., Scott, N.R., Walker, L.P. 2005. The Sun Grant Initiative – A New Day for Agriculture. Hort Sci. 40(2):Apr. 2005.

Hansgate, A. Schloss, P. D., Hay, A. G., and Walker, L. P. 2005. Molecular Characterization of Fungal Community Dynamics in the Initial Stages of Composting. FEMS Microbiology Ecology, 51: 209-214.

Schloss, P. D., Hay, A. G., Wilson, D. B., Gossett, J. M., and Walker, L. P. 2005. Quantifying Bacterial Population Dynamics in Compost using 16S rRNA gene probes. Applied Microbiology and Biotechnology, 66: 457-463.

Schloss, P. D., Hay, A. G., Wilson, D. B., and Walker, L. P. 2003. Tracking Temporal Changes of Bacterial Community Fingerprints During the Initial Stages of Composting. FEMS Microbiology Ecology, 46: 1-9.

Jung, H., Wilson, D. B. and Walker, L. P. 2003. Binding and reversibility of Thermobifida fusca Cel5A, Cel6B and Cel48A and their respective Catalytic Domains to Bacterial Microcrystalline Cellulose. Biotechnology and Bioengineering, 84: 151-159.

Selected Invited Presentations:

A View from Cornell on the Evolving Biofuels Industry, Presented at the Bi-annual Meeting of the American Council on Renewable Energy, Higher Education Committee, Nov. 28, 2007, Washington, DC.

The Evolving Paradigm of Agriculture and Forestry as a Supplier of Energy, Presented at the State of New York Dept. of Agriculture and Markets, Advisory Council on Agriculture, Nov. 5, 2007, Morrisville, NY.

Transitioning to a Sustainable Global Energy Future, Presented at the 2007 Corning Energy Summit, Global Energy Management, Sept. 18, 2007, Corning, NY.

Nanotechnology as an Enabler for Biofuels Research and Development, Presented at the 8^th Annual Nanobiotechnology Symposium, Oct. 1, 2007, Cornell University, Ithaca, NY.

Evolving the Paradigm of Agriculture as a Supplier of Energy and Chemicals, Presented at the University Industry Consortium Spring Meeting, April 19, 2007, Rochester, NY.

Cornell’s Cellulosic Biofuels Research Team, Presented to Representatives from Shell Oil, April 11, 2007, Cornell Campus.

The Evolving Paradigm of Agriculture as a Supplier of Energy and Industrial Raw Materials, Congresswoman Gillibrand’s Town Hall Meeting, Feb., 19, 2007, Rhinebeck, NY.

The Evolving Paradigm of Agriculture as a Supplier of Energy and Industrial Raw Materials, Presented at the New York State Association of Counties Legislative Conference, Jan. 29, 2007, Albany, NY.