The University of Toledo
Chemical Engineering (MS 305)
3061 Nitschke Hall
1650 N Westwood Ave
Toledo, Ohio 43606-3390
Ph.D. in Chemical Engineering, Rutgers University, New Brunswick, NJ
M.S. in Chemical Engineering, Rutgers University, New Brunswick, NJ
B.S. in Chemical Engineering, Cornell University, Ithaca, NY
Current research is focused in the area of separations, particularly crystallization and precipitation processes and biofuels production.
In the area of bioseparations, we are focusing on protein crystallization with application to single crystal growth for structure determination and industrial crystallization for protein purification. In a projected recently funded through the Center for the Advancement of Science in Space (CASIS) “Optimization of Protein Crystal Growth for Determination of Enzyme Mechanisms through Advanced Diffraction Techniques” our lab will focus on growth of neutron diffraction quality protein crystals (with co-I’s Drs. Ronning, Mueser, Hanson & Chen). The overall goal of our investigation is to produce protein crystals large enough and of adequate quality to use neutron diffraction crystallography to locate protons and hydrogen atoms in a 3-D structure. Neutron diffraction can provide key insights into enzyme mechanisms but requires large, defective-free crystals that are difficult, if not impossible, to produce in unit gravity. The need for large crystals makes the International Space Station an ideal environment for testing whether large, diffraction-quality crystals of the target proteins can be grown in microgravity.
In the biofuels area, we are developing a pretreatment method for lignocellulose using the unique solvation properties of ionic liquids. Cellulose, a polymer of glucose, is the most abundant renewable resource in the world. However, its potential as a source of raw materials is limited by the strong hydrogen bonding network in its highly crystalline natural form. Disruption of this structure allows effective chemical modification or hydrolysis of cellulose into its glucose subunits. Ionic liquids (ILs) are non-derivitizing solvents of cellulose that efficiently disrupt its structure without production of fermentation inhibitors. In our process, cellulose is pretreated with an IL forming an easily modified amorphous structure. The amorphous cellulose substrate treated with IL can be enzymatically hydrolyzed into its glucose subunits at rates orders of magnitude greater than untreated cellulose at low enzyme loadings.
Christopher J. Barr, B. Leif Hanson, Kevin Click, Grace Perotta, Constance A. Schall, Influence of ionic-liquid incubation temperature on changes in cellulose structure, biomass composition, and enzymatic digestibility, Cellulose, accepted (2013).
Amber L. Milliren; J.C. Wissinger; V.Gottumukala: C. A. Schall, Kinetics of soybean oil hydrolysis in subcritical water, Fuel, (2013), 108, 277-281.
Barr, C.J.; J.A. Mertens, C. A. Schall, Critical cellulase and hemicellulase activities for hydrolysis of ionic liquid pretreated biomass, Bioresource Technology (2012), 104, 408-485.
Shah, Binal N.; Chinte, Unmesh; Tomanicek, Stephen J.; Hanson, B. Leif; Schall, Constance A, Flash Cooling Protein Crystals: Estimate of Cryoprotectant Concentration Using Thermal Properties, Crystal Growth & Design (2011), 11(5), 1493-1501.
Samayam, I.P.; B.L. Hanson, P. Langan, C.A. Schall, Ionic-liquid-induced changes in cellulose structure associated with enhanced biomass hydrolysis, Biomacromolecules (2011). 12(8), 3091-3098.
Samayam, Indira P., C.A. Schall (2010) Saccharification of ionic liquid pretreated biomass with commercial enzyme mixtures, Bioresource Technology 101,3561–3566.
Schutt, K.; D. White, R.A Gosavi, C. A. Schall, (2009) The Distribution of Impurities in Lysozyme Crystals, J. Crystal Growth, 311(16), 4062-4068.
Gosavi, R. A.; V. Bhamidi, S. Varanasi and C. A. Schall, (2009) Beneficial Effect of Solubility Enhancers on Protein Crystal Nucleation and Growth, Langmuir, 25(8), 4579-458.
Gosavi, Rajendrakumar A.; Mueser, Timothy C.; Schall, Constance A., Optimization of buffer solutions for protein crystallization. Acta Crystallographica, Section D: Biological Crystallography (2008), D64(5), 506-514.
Zhao, Fei; Thehazhnan K. Ponnaiyan, Christa M. Graham, Constance A. Schall, Sasidhar Varanasi, Jared L. Anderson, (2008) Determination of ethanol in ionic liquids using headspace solid-phase microextraction–gas chromatography, Anal. Bioanal. Chem., DOI 10.1007/s00216-008-2398-9.
Dadi, A., C.A. Schall, S.Varanasi, (2007) Mitigation of cellulose recalcitrance to enzymatic hydrolysis by ionic liquid pretreatment, Applied Biochemistry and Biotechnology, 136-140, 407-421.
Dadi, A. P., S. Varanasi, C. A. Schall (2006) Enhancement of cellulose saccharification Kinetics using an ionic liquid pretreatment step, Biotechnology and Bioengineering, 95(5), 904-910.
Izaac, A., C.A. Schall and T. C. Mueser (2006) Assessment of a preliminary solubility screen to improve crystallization trials: uncoupling crystal condition searches, Acta Crystallographica Section D: Biological Crystallography D62, 833-842.
Chinte, U.; B, Shah,Yu Sheng Chen, Yu Sheng; A. A. Pinkerton, C. A. Schall, B. L. Hanson, Cryogenic (<20 K) helium cooling mitigates radiation damage to protein crystals. Acta Crystallographica, Section D: Biological Crystallography (2007), D63(4), 486-492.
Shah, B., C.A. Schall, (2006) Measurement and modeling of the glass transition temperatures of multi-component solutions, Thermochimica Acta, 443, 78-86.