Juan Hong
Professor, Chemical Engineering & Materials Science
The Henry Samueli School of Engineering
The Henry Samueli School of Engineering
PH.D., Purdue University
University of California, Irvine
816C Engineering Tower
Mail Code: 2575
Irvine, CA 92697
816C Engineering Tower
Mail Code: 2575
Irvine, CA 92697
Research Interests
Biochemical Processes and Separation Processes
Academic Distinctions
Appointments
Research Abstract
Optimal Operating Conditions for Displacement Chromatography
Investigator: J. Hong
Research Assistant: K. Lee
Support: Toxic Substances Research and Training Program, University of California, Davis
The objective is to investigate optimal operating conditions for the displacement development technique in the separation and concentration of bioproducts based upon both theoretical and experimental studies. The parameters for study include: affinity of the displacer for adsorbents, concentration of displacer, displacer consumption, band width of a pure component, length of adsorbent bed, particle size of adsorbent, relative length of mass transfer zone (diffusive zone), and required pressure drop.
Kinetic Models and Optimization of Bioreactor Operation for Mercury Detoxification
Investigators: J. Hong and B. Olson
Research Assistant: J. Chang
Support: California Biotechnology Research Grant
Electric Power Research Institute
The researchers are studying the basic characteristics of bacterial detoxification of mercury at the cellular level. Experimental work is determining the effects of environmental factors on cell growth, induction of gene amplification, transcription to mR NA, translation to reductase, specific detoxification rate, and transport rate of elemental mercury across cell membrane. A method to estimate kinetics is based on batch culture experiments with very small inocula. Such low initial cell concentrations rest in extended exponential cell growth phase during which culture conditions remain unchanged, permitting thereby precise estimation of kinetics from batch experiments. This approach is especially well-suited for microorganisms subject to age variation of phenotype such as the extent of amplification of mer operon.
Regulation of Ribosome Synthesis in Recombinant Escherichia coli and Its Potential Engineering Applications
Investigators: J. Hong and H.C. Lim
Research Assistant: H. Yun
Support: University of California Regents' Fellowship
A higher fraction of ribosomes in E. coli cells are engaged in protein synthesis when grown at a higher growth rate, implying that, in a plasmid-bearing recombinant cell, there is competition for the free ribosomes. The interaction between the plasmid and host chromosomes for free ribosomes is being studied by measuring the fraction of functioning ribosomes during cell growth. Plasmid-bearing recombinant cells are being grown at different growth rates using continuous stirred fermentors and the ribosome contents are being analyzed by gel filtration chromatography.
Unequal Specific Uptake Rates of Glucose Anomers and Escherichia Coli
Investigators: J. Hong and H.C. Lim
Research Assistant: K. Han
Support: National Science Foundation
The researchers are studying the effects of unequal specific uptake rates of the glucose anomers by yeast and E. coli and optimization of fermentation processes by manipulating the composition of glucose in the feed stream for continuous operation and the glucose feeding policy for fed-batch operation.
Investigator: J. Hong
Research Assistant: K. Lee
Support: Toxic Substances Research and Training Program, University of California, Davis
The objective is to investigate optimal operating conditions for the displacement development technique in the separation and concentration of bioproducts based upon both theoretical and experimental studies. The parameters for study include: affinity of the displacer for adsorbents, concentration of displacer, displacer consumption, band width of a pure component, length of adsorbent bed, particle size of adsorbent, relative length of mass transfer zone (diffusive zone), and required pressure drop.
Kinetic Models and Optimization of Bioreactor Operation for Mercury Detoxification
Investigators: J. Hong and B. Olson
Research Assistant: J. Chang
Support: California Biotechnology Research Grant
Electric Power Research Institute
The researchers are studying the basic characteristics of bacterial detoxification of mercury at the cellular level. Experimental work is determining the effects of environmental factors on cell growth, induction of gene amplification, transcription to mR NA, translation to reductase, specific detoxification rate, and transport rate of elemental mercury across cell membrane. A method to estimate kinetics is based on batch culture experiments with very small inocula. Such low initial cell concentrations rest in extended exponential cell growth phase during which culture conditions remain unchanged, permitting thereby precise estimation of kinetics from batch experiments. This approach is especially well-suited for microorganisms subject to age variation of phenotype such as the extent of amplification of mer operon.
Regulation of Ribosome Synthesis in Recombinant Escherichia coli and Its Potential Engineering Applications
Investigators: J. Hong and H.C. Lim
Research Assistant: H. Yun
Support: University of California Regents' Fellowship
A higher fraction of ribosomes in E. coli cells are engaged in protein synthesis when grown at a higher growth rate, implying that, in a plasmid-bearing recombinant cell, there is competition for the free ribosomes. The interaction between the plasmid and host chromosomes for free ribosomes is being studied by measuring the fraction of functioning ribosomes during cell growth. Plasmid-bearing recombinant cells are being grown at different growth rates using continuous stirred fermentors and the ribosome contents are being analyzed by gel filtration chromatography.
Unequal Specific Uptake Rates of Glucose Anomers and Escherichia Coli
Investigators: J. Hong and H.C. Lim
Research Assistant: K. Han
Support: National Science Foundation
The researchers are studying the effects of unequal specific uptake rates of the glucose anomers by yeast and E. coli and optimization of fermentation processes by manipulating the composition of glucose in the feed stream for continuous operation and the glucose feeding policy for fed-batch operation.
Publications
H. S. Lee, and J. Hong, A Kinetic of Glucose Isomerization to Fructose by Immobilized Glucose Isomerase: Anomeric Reactivity of D-Glucose in Kinetic Model, J. of Biotechnology, 84, 145-153 (2001).
H. S. Lee, and J. Hong, Chemical Synthesis and Characterization of Polypyrrole Coated on Porous Membranes and Its Electrochemical Stability, Synthetic Metals, 113, 115-119 (2000)
H. S. Lee, and J. Hong, Electrokinetic Separation of Lysine and Aspartic Acid using Polypyrrole-coated Stacked Membrane System, J. of Membrane Science, 169, 277-285 (2000)
H. S. Lee, and J. Hong, Chiral and Electrokinetic Separation of Amino Acids using Polypyrrole-coated Adsorbents, J. of Chromatography A. 868, 189-196 (2000)
K.H. Kim, and J. Hong, Dynamic Extraction of Essential Oil Components from Spearmint Leaves by Using Supercritical Carbon Dioxide, Separation Science and Technology, 35, 315-322, 2000
K. H. Kim, and J. Hong, Equilibrium Solubilities of Spearmint Oil Components in Supercritical Carbon Dioxide, Fluid Phase Equilibria, 164, 107-115 (1999)
Link to this profile
https://faculty.uci.edu/profile/?facultyId=2355
https://faculty.uci.edu/profile/?facultyId=2355
Last updated
03/15/2002
03/15/2002