Professor
Sunghoon Park
School of Chemical and Biomolecular Engineering, Pusan National University, Korea
Title of the talk: Metabolic engineering and microbial physiology for simultaneous production of multiple fuels and chemicals using a single microorganism
Abstract
Microorganisms have evolved to optimize their growth, rather than the formation of metabolite(s) useful to human. Microbial growth occurs with or through generation of multiple metabolites, but metabolic engineering usually focuses on the production of a ‘single’ compound by re-designing metabolic pathways. This often seriously interferes with cellular metabolisms, hurts cell growth and viability, and makes the microorganism to function inefficiently as microbial cell factory. Production of properly-selected, multiple metabolites, instead of a single metabolite, can offer flexible balancing of the in vivo metabolic flux and easier maintenance of cellular homeostasis including redox state. To demonstrate the potential of the co-production strategy, we have studied Klebsiella pneumoniae for co-production of 3-hydroxypropionic acid (3-HP) and 1,3-propanediol (1,3-PDO) or 1,3-PDO and 2,3-butanediol (2,3-BDO) from glycerol, and Escherichia coli for co-production of H2 and ethanol or 3-HP from glucose. Co-production of 3-HP and 1,3-PDO made the generation and consumption of NAD(H) well-balanced, reduced the accumulation of the toxic intermediate, 3-hydroxypropionaldehyde, and resulted in high glycerol-to-products yield (>0.8) at high titer (>70 g/L). Co-production of 1,3-PDO and 2,3-BDO by K. pneumoniae alleviated metabolic traffic at the pyruvate node, reduced acetate accumulation, and enabled the maintenance of redox balance. Co-production of H2 and ethanol from glucose required the re-direction of carbon flux to the Pentose Phosphate (PP) pathway from the Embden-Myerhoff-Parnas (EMP) pathway. Increase in NAD(P)H supply enhanced ethanol production, and H2 and ethanol could be obtained with the theoretical maximum yields and negligible acetate. This lecture also discusses the challenges of the co-production strategy.
Biography
Prof. Sunghoon Park received Ph.D. degree in Chemical Engineering from University of California, Davis in 1988. He worked for CKD Pharmaceutical Co, Seoul, Korea in 1982-84, and Lawrence Livermore National Laboratory, CA, USA in1988-91. Since 1991, he is Professor at the School of Chemical and Biomolecular Engineering, Pusan National University (PNU), Korea. Dr. Park is former Editor-in-Chief of Biotechnology and Bioprocess Engineering (BBE) and currently, a Senior Editor of Journal of Industrial Microbiology and Biotechnology (JIMB). Major research interest lies in metabolic engineering and synthetic biotechnology for microbial production of biofuels and biochemicals from renewable resources. Dr. Park has published over 170 papers in peer-reviewed journals and holds >30 patents.
Publications: Researchgate.