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Expertise: Transformation (E. coli, yeast cell culture growth, and expression of enzymes and mutants); Mutagenesis with PCR; His-tagged protein purification; Gel electrophoresis and Western blotting; Expressed enzyme activity assays; Enzyme immobilization protocols (various substrates - silica beads, sol-gel, field effect transistors (BioFET), resins); Activity assays and lifetime studies for enzymes attached to substrates. Projects: Currently, as a member of the Enhanced Biomass to Bioenergy Interconversion team, my goals are to genetically engineer enzymes to enhance the interconversion of biological fuels to glucose. To achieve these goals my development studies include optimizing expression of active Sulfolobus Solfataricus extremophile cellulase enzyme and optimizing the expression of CelA and CelB endoglucanases with the purpose of applying these optimizations to identify mutants with improved enzyme performance. In previous projects, I have developed a bioreformer using serially-linked continuous flow packed bed reactors to convert sucrose into glucose as a fuel source (Bio Micro Fuel Cell), performed electrokinetic trapping of proteins (Molecular Integrated Microsystems) and developed biosensors by characterizing immobilized organophosphate hydrolase and acetylcholinesterase enzymes attached to various substrates (Biosensor and BioFET Sensor Development). In the course of my career at Sandia I have also acquired a number of other non-biology related skills and technical laboratory experience in many diverse research areas. Two previous long-term projects have included performing mass spectrometric detection of gas species present in low-pressure flames along with laser induced fluorescence measurements of radical species (Combustion Chemistry Division) and thermo-gravimetric analysis with mass spectrometric determination of sodium and potassium nitrate and nitrite salt decomposition for a solar energy project (Exploratory Materials Division). A summary of past projects includes:
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PublicationsYu, D., Volponi, J., Chhabra, S., Brinker, C.J., Mulchandani, A., and Singh, A.K., (2005) "Aqueous Sol-gel Encapsulation of Genetically Engineered Moraxella Cells for the Detection of Organophosphates.” Biosensors & Bioelectronics 20 (7): 1433-1437. Flounders, A.W., Singh, A.K., Volponi, J.V., Carichner, S.C., Wally, K., Simonian, A.S., Wild, J.R. and Schoeniger, J.S. (1999) "Development of Sensors for Direct Detection of Organophosphates. II. Sol-gel Modified Field Effect Transistor with Immobilized Organophosphate Hydrolase." Biosensors & Bioelectronics 14 (8-9): 715-722. Singh, A.K., Flounders, A.W., Volponi, J.V., Ashley, C.S., Wally, K., and Schoeniger, J.S. (1999) "Development of Sensors for Direct Detection of Organophosphates. I. Immobilization, Characterization and Stabilization of Acetylcholinesterase and Organophosphate Hydrolase on Silica Supports." Biosensors & Bioelectronics, 14 (8-9): 703-713. Miller, J.A., Volponi, J.V. and Pauwels, J.-F., (1996) "The Effect of Allene Addition on the Structure of a Rich C2H2/O2/Ar Flame." Combustion and Flame 105 (4): 451-461. Pauwels, J.-F., Volponi, J.V. and Miller, J.A., (1995) "The Oxidation of Allene in a Low-Pressure H2/O2/Ar-C3H4 Flame." Combust. Sci. and Tech. 110-111: 249-276. Volponi, J.V. and Branch, M.C. (1995) "Structure of H2-NO2-Argon and H2-O2-Argon Laminar Premixed Flames." Combust. Sci. and Tech. 105: 195-209. Volponi, J.V., McLean, W.J., Fristrom, R.M. and Munir, Z.A. (1986) "Determination of H, OH, and O Species Concentrations by Deuterium Scavenging in Low Pressure Acetylene-Oxygen-Argon Flames." Combustion and Flame 65: 243-248. Kramer, C.M., Munir, Z.A. and Volponi, J.V. (1983) "Simultaneous Dynamic Thermogravimetry and Mass Spectrometry of the Evaporation of Alkali Metal Nitrates and Nitrites." Journal of Thermal Analysis 27: 401-408. Kramer, C.M., Munir, Z.A. and Volponi, J.V. (1982) "Screening Tests of Sodium Nitrate and Potassium Nitrate Decomposition." Solar Energy 29 (5): 437-439. Kramer, C.M., Munir, Z.A. and Volponi, J.V. (1982) "Differential Scanning Calorimetry of Sodium and Potassium Nitrates and Nitrites." Thermochimica Acta 55: 11-17. Kramer, C.M., Munir, Z.M. and Volponi, J.V. (1981) "Screening Tests of Sodium Nitrite Decomposition." Solar Energy Materials 6: 85-95. PatentsMcLean, W.J., Thorne, L.R. and Volponi, J.V., “Catalytic Igniters and Their Use to Ignite Lean Hydrogen-Air Mixtures”, Awards & Honors
Education
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Contact InformationJoanne Volponi jvvolpo@sandia.gov |
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