Towards advanced microbial biotechnology


Oct 1, 2013 (4 years and 11 days ago)



Sang Yup Lee

Metabolic and Biomolecular Engineering National Research Laboratory

Dept. of Chemical Engineering and BioProcess Engineering Research Center

Korea Advanc
ed Institute of Science and Technology

Taejon 305
701, Korea (

We have been employing various microorganisms for the pr
oduction of useful
bioproducts such as primary metabolites, secondary metabolites, proteins,
polysaccharides, and many others. Due to the limited ability of natural microorganisms,
metabolic engineering strategies have been employed for improving the metab
pathways of microorganisms. Metabolic engineering can be defined as purposeful
modification of cellular metabolic pathways for the enhanced production of a desired
product or modified/new product, degradation of xenobiotics, and utilization of
sive raw materials. Metabolic flux analysis and metabolic control analysis along
with recombinant DNA techniques are at the heart of this discipline. Thanks to the on
going genome projects for many industrially important microorganisms, metabolic
ng strategies can be more

planned to achieve the desired goals.
Complete genome sequences along with the tools for analyzing transcriptome and
proteome are providing us with the possibility of addressing complex biological
questions including m
etabolic control, regulation and metabolic fluxes. For example,
transcriptome analysis by employing DNA chip allows us to examine the global pattern
of gene expression at mRNA level. Two dimensional gel electrophoresis of cellular
proteins can be used to e
xamine the global proteome content, which provides us with
the information on gene expression at protein level. We have been working on designing
metabolically engineered
Escherichia coli

for the production of polyhydroxyalkanoates,
a family of biodegradab
le plastics and elastomers. By transcriptome and proteome
analysis along with metabolic flux analysis, we were able to obtain the information on
the physiological state of cells under polymer producing condition, which would
otherwise be difficult to under
stand. Detailed results on the production of
polyhydroxyalkanoates, pharmaceutical proteins, and several primary metabolites by
employing metabolically engineered
E. coli

will be presented. Also, discussion will be
made how these new powerful tools based o
n genomics and proteomics can be used for
advanced metabolic engineering.