Engineering of Glycolytic Pathways in Escherichia coli for Co-production of Hydrogen and Ethanol from Glucose
Lecture: Engineering of Glycolytic Pathways in Escherichia coli for Co-production of Hydrogen and Ethanol from Glucose
Lecturer: Prof. Sunghoon Park, Pusan National University, South Korea
Time: 3:30 pm, Nov 5, 2015
Location: Meeting Room 205 of Administration Building
Introduction of Lecturer:
I. EDUCATION
1976 - 1980, Seoul National University, Korea, B.S., Chemical Technology
1980 - 1982, Seoul National University, Korea, M.S., Chemical Technology
1984 - 1988, University of California, Davis, CA, Ph.D., Chemical Engineering
II. EXPERIENCES
03/1991 - present: Professor of Chemical and Biomolecular Engineering, Pusan National University (PNU), Korea
09/2012 - 08/2014: External Examiner, Univ. Malaya, Dept. Biotechnol.
01/2010 - present: Adjunct Professor, East China Univ. of Science and Technol., Dept. Biotechnol., Shanghai, China
01/2009 - 12/2014: Editor-in-Chief, Biotechnol and Bioprocess Eng (BBE)
08/2010 - present: Senior Editor, J. Industrial Microbiology & Biotechnology
08/2008 - 08/2011: Dean, Office of International Affairs, PNU
11/2006 - 07/2008: Director, Institute for Environmental Studies, PNU
06/2002 - 05/2005: Director, Institute for Environmental Technology and Industry
10/1988 - 02/1991: Research Staff, Chemical and Biomedical Sciences Division, Lawrence Livermore National Laboratory, CA
10/1982 - 08/1984: Research Engineer, CKD pharmaceutical Co., Seoul, Korea
III. PROFESSIONAL MEMBERSHIPS
Korean Society for Biotechnology and Bioengineering
Korean Institute of Chemical Engineers
American Society for Microbiology
Society for Industrial Microbiology and Biotechnology, USA
IV. PUBLICATIONS
Over 150 papers in peer-reviewed journals and about 30 patents in the field of biochemical engineering and biotechnology.
V. CURRENT RESEARCH INTERESTS
Metabolic engineering, enzyme engineering, system biology and microbial fermentation for: Biological production of 3-hydroxypropionic acid (3-HP) and 1,3-propanediol from glycerol; and biological hydrogen production
Park's homepage: http://bcelab.pusan.ac.kr
Lecture Abstract:
Biologically, hydrogen (H2) can be produced from glucose through dark fermentation and photo-fermentation. Hydrogen production by dark fermentation is fast and simple, but gives low theoretical yield of 2-4 mol H2/mol glucose. Co-production of H2 and ethanol, both of which are good biofuels, has been suggested as a solution to this problem. To prove the feasibility, glucose assimilation in Escherichia coli was modified by eliminating phosphofructokinase (pfkA) or phosphoglucose isomerase (pgi) in Embden-Meyhof-Parnas (EMP) pathway and/or 6-phosphogluconate dehydratase (edd) and/or 2-keto-3deoxy-6-phosphogluconate aldolase (eda) in Entner-Doudoroff (ED) pathway. In addition, the pentose-phosphate (PP) pathway, which can generate more NADPH than the EMP or ED pathway, was fortified by overexpressing two key enzymes, Zwf and Gnd, present at the node of glycolytic pathway branches. The strains without overexpression of Zwf and/or Gnd did not show improved performance because glucose metabolism largely stopped at the pyruvate node. In comparison, when Zwf and/or Gnd were overexpressed in E. coli strains devoid of pfkA, pgi, edd-eda and/or pta-ack, co-production of H2 and ethanol was significantly improved with the concomitant reduction of pyruvate secretion. Gene expression and metabolic flux analyses showed that, upon overexpression of Zwf and Gnd, role of the PP pathway for glucose assimilation relative to that of EMP or ED pathway was greatly enhanced. The maximum co-production yields were 1.71 mol H2/mol glucose and 1.41 mol ethanol/mol glucose, respectively. This study suggests that the robust central carbon metabolisms and the amount of NAD(P)H formed under anaerobic conditions can be altered by modifying (the activity of) several key enzymes.
