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Distinguished Professor Lee Elected to the NAS
Distinguished Professor Sang Yup Lee of the Department of Chemical and Biomolecular Engineering was elected as a foreign associate to the US National Academy of Sciences (NAS) on May 2. The National Academy of Sciences elected 84 new members and 21 foreign associates in recognition of their distinguished and continuing achievements in their original research. Election to the Academy is widely regarded as one of the highest honors that a scientist can receive.
Professor Lee was also elected in 2010 as a member of the US National Academy of Engineering (NAE) for his leadership in microbial biotechnology and metabolic engineering, including the development of fermentation processes for biodegradable polymers and organic acids. Until 2016, there are only 12 people worldwide who are foreign associates of both NAS and NAE.
He is the first Korean elected to both prestigious academies, the NAS and the NAE in the US. Professor Lee is currently the dean of KAIST Institutes, the world leading institute for multi-and interdisciplinary research. He is also serving as co-chair of the Global Council on Biotechnology and member of the Global Future Council on the Fourth Industrial Revolution, the World Economic Forum.
2017.05.16 View 7903 -
Unveiling the Distinctive Features of Industrial Microorganism
KAIST researchers have sequenced the whole genome of Clostridium tyrobutyricum, which has a higher tolerance to toxic chemicals, such as 1-butanol, compared to other clostridial bacterial strains.
Clostridium tyrobutyricum, a Gram-positive, anaerobic spore-forming bacterium, is considered a promising industrial host strain for the production of various chemicals including butyric acid which has many applications in different industries such as a precursor to biofuels. Despite such potential, C. tyrobutyricum has received little attention, mainly due to a limited understanding of its genotypic and metabolic characteristics at the genome level.
A Korean research team headed by Distinguished Professor Sang Yup Lee of the Chemical and Biomolecular Engineering Department at the Korea Advanced Institute of Science and Technology (KAIST) deciphered the genome sequence of C. tyrobutyricum and its proteome profiles during the course of batch fermentation. As a result, the research team learned that the bacterium is not only capable of producing a large amount of butyric acid but also can tolerate toxic compounds such as 1-butanol. The research results were published in mBio on June 14, 2016.
The team adopted a genoproteomic approach, combining genomics and proteomics, to investigate the metabolic features of C. tyrobutyricum. Unlike Clostridium acetobutylicum, the most widely used organism for 1-butanol production, C. tyrobutyricum has a novel butyrate-producing pathway and various mechanisms for energy conservation under anaerobic conditions. The expression of various metabolic genes, including those involved in butyrate formation, was analyzed using the “shotgun” proteome approach.
To date, the bio-based production of 1-butanol, a next-generation biofuel, has relied on several clostridial hosts including C. acetobutylicum and C. beijerinckii. However, these organisms have a low tolerance against 1-butanol even though they are naturally capable of producing it. C. tyrobutyricum cannot produce 1-butanol itself, but has a higher 1-butanol-tolerance and rapid uptake of monosaccharides, compared to those two species.
The team identified most of the genes involved in the central metabolism of C. tyrobutyricum from the whole-genome and shotgun proteome data, and this study will accelerate the bacterium’s engineering to produce useful chemicals including butyric acid and 1-butanol, replacing traditional bacterial hosts.
Professor Lee said,
“The unique metabolic features and energy conservation mechanisms of C. tyrobutyricum can be employed in the various microbial hosts we have previously developed to further improve their productivity and yield. Moreover, findings on C. tyrobutyricum revealed by this study will be the first step to directly engineer this bacterium.”
Director Jin-Woo Kim at the Platform Technology Division of the Ministry of Science, ICT and Future Planning of Korea, who oversees the Technology Development Program to Solve Climate Change, said,
“Over the years, Professor Lee’s team has researched the development of a bio-refinery system to produce natural and non-natural chemicals with the systems metabolic engineering of microorganisms. They were able to design strategies for the development of diverse industrial microbial strains to produce useful chemicals from inedible biomass-based carbon dioxide fixation. We believe the efficient production of butyric acid using a metabolic engineering approach will play an important role in the establishment of a bioprocess for chemical production.”
The title of the research paper is “Deciphering Clostridium tyrobutyricum Metabolism Based on the Who-Genome Sequence and Proteome Analyses.” (DOI: 10.1128/mBio.00743-16)
The lead authors are Joungmin Lee, a post-doctoral fellow in the BioProcess Research Center at KAIST, currently working in CJ CheilJedang Research Institute; Yu-Sin Jang, a research fellow in the BioProcess Research Center at KAIST, currently working at Gyeongsang National University as an assistant professor; and Mee-Jung Han, an assistant professor in the Environmental Engineering and Energy Department at Dongyang University. Jin Young Kim, a senior researcher at the Korea Basic Science Institute, also participated in the research.
This research was supported by the Technology Development Program to Solve Climate Change’s research project entitled “Systems Metabolic Engineering for Biorefineries” from the Ministry of Science, ICT and Future Planning through the National Research Foundation of Korea (NRF-2012M1A2A2026556).
Schematic Diagram of C. tyrobutyricum’s Genome Sequence and Its Proteome Profiles
The picture below shows the complete genome sequence, global protein expression profiles, and the genome-based metabolic characteristics during batch fermentation of C. tyrobutyricum.
2016.06.20 View 9484 -
Non-Natural Biomedical Polymers Produced from Microorganisms
KAIST researchers have developed metabolically engineered Escherichia coli strains to synthesize non-natural, biomedically important polymers including poly(lactate-co-glycolate) (PLGA), previously considered impossible to obtain from biobased materials.
Renewable non-food biomass could potentially replace petrochemical raw materials to produce energy sources, useful chemicals, or a vast array of petroleum-based end products such as plastics, lubricants, paints, fertilizers, and vitamin capsules. In recent years, biorefineries which transform non-edible biomass into fuel, heat, power, chemicals, and materials have received a great deal of attention as a sustainable alternative to decreasing the reliance on fossil fuels.
A research team headed by Distinguished Professor Sang Yup Lee of the Chemical and Biomolecular Engineering Department at KAIST has established a biorefinery system to create non-natural polymers from natural sources, allowing various plastics to be made in an environmentally-friendly and sustainable manner. The research results were published online in Nature Biotechnology on March 7, 2016. The print version will be issued in April 2016.
The research team adopted a systems metabolic engineering approach to develop a microorganism that can produce diverse non-natural, biomedically important polymers and succeeded in synthesizing poly(lactate-co-glycolate) (PLGA), a copolymer of two different polymer monomers, lactic and glycolic acid. PLGA is biodegradable, biocompatible, and non-toxic, and has been widely used in biomedical and therapeutic applications such as surgical sutures, prosthetic devices, drug delivery, and tissue engineering.
Inspired by the biosynthesis process for polyhydroxyalkanoates (PHAs), biologically-derived polyesters produced in nature by the bacterial fermentation of sugar or lipids, the research team designed a metabolic pathway for the biosynthesis of PLGA through microbial fermentation directly from carbohydrates in Escherichia coli (E. coli) strains.
The team had previously reported a recombinant E. coli producing PLGA by using the glyoxylate shunt pathway for the generation of glycolate from glucose, which was disclosed in their patents KR10-1575585-0000 (filing date of March 11, 2011), US08883463 and JP5820363. However, they discovered that the polymer content and glycolate fraction of PLGA could not be significantly enhanced via further engineering techniques. Thus, in this research, the team introduced a heterologous pathway to produce glycolate from xylose and succeeded in developing the recombinant E. coli producing PLGA and various novel copolymers much more efficiently.
In order to produce PLGA by microbial fermentation directly from carbohydrates, the team incorporated external and engineered enzymes as catalysts to co-polymerize PLGA while establishing a few additional metabolic pathways for the biosynthesis to produce a range of different non-natural polymers, some for the first time. This bio-based synthetic process for PLGA and other polymers could substitute for the existing complicated chemical production that involves the preparation and purification of precursors, chemical polymerization processes, and the elimination of metal catalysts.
Professor Lee and his team performed in silico genome-scale metabolic simulations of the E. coli cell to predict and analyze changes in the metabolic fluxes of cells which were caused by the introduction of external metabolic pathways. Based on these results, genes are manipulated to optimize metabolic fluxes by eliminating the genes responsible for byproducts formation and enhancing the expression levels of certain genes, thereby achieving the effective production of target polymers as well as stimulating cell growth.
The team utilized the structural basis of broad substrate specificity of the key synthesizing enzyme, PHA synthase, to incorporate various co-monomers with main and side chains of different lengths. These monomers were produced inside the cell by metabolic engineering, and then copolymerized to improve the material properties of PLGA. As a result, a variety of PLGA copolymers with different monomer compositions such as the US Food and Drug Administration (FDA)-approved monomers, 3-hydroxyburate, 4-hydroxyburate, and 6-hydroxyhexanoate, were produced. Newly applied bioplastics such as 5-hydroxyvalerate and 2-hydroxyisovalerate were also made.
The team employed a systems metabolic engineering application which, according to the researchers, is the first successful example of biological production of PGLA and several novel copolymers from renewable biomass by one-step direct fermentation of metabolically engineered E.coli.
Professor Lee said, “We presented important findings that non-natural polymers, such as PLGA which is commonly used for drug delivery or biomedical devices, were produced by a metabolically engineered gut bacterium. Our research is meaningful in that it proposes a platform strategy in metabolic engineering, which can be further utilized in the development of numerous non-natural, useful polymers.”
Director Ilsub Baek at the Platform Technology Division of the Ministry of Science, ICT and Future Planning of Korea, who oversees the Technology Development Program to Solve Climate Change, said, “Professor Lee has led one of our research projects, the Systems Metabolic Engineering for Biorefineries, which began as part of the Ministry’s Technology Development Program to Solve Climate Change. He and his team have continuously achieved promising results and been attracting greater interest from the global scientific community. As climate change technology grows more important, this research on the biological production of non-natural, high value polymers will have a great impact on science and industry.”
The title of the research paper is “One-step Fermentative Production of Poly(lactate-co-glycolate) from Carbohydrates in Escherichia coli (DOI: 10.1038/nbt.3485).” The lead authors are So Young Choi, a Ph.D. candidate in the Department of Chemical and Biomolecular Engineering at KAIST, and Si Jae Park, Assistant Professor of the Environmental Engineering and Energy Department at Myongji University. Won Jun Kim and Jung Eun Yang, both doctoral students in the Department of Chemical and Biomolecular Engineering at KAIST, also participated in the research.
This research was supported by the Technology Development Program to Solve Climate Change’s research project titled “Systems Metabolic Engineering for Biorefineries” from the Ministry of Science, ICT and Future Planning through the National Research Foundation of Korea (NRF-2012M1A2A2026556).
Figure: Production of PLGA and Other Non-Natural Copolymers
This schematic diagram shows the overall conceptualization of how metabolically engineered E. coli produced a variety of PLGAs with different monomer compositions, proposing the chemosynthetic process of non-natural polymers from biomass. The non-natural polymer PLGA and its other copolymers, which were produced by engineered bacteria developed by taking a systems metabolic engineering approach, accumulate in granule forms within a cell.
2016.03.08 View 10874 -
President Steve Kang of KAIST Receives the Outstanding Contribution Award from the Korean-American Scientists and Engineers Association
The Korean-American Scientists and Engineers Association (KSEA), a non-profit Korean professional organization based in the United States with over 6,000 registered members, bestowed upon President Steve Kang of KAIST the 2015 Outstanding Contribution Award.
The award is presented to a person who has made significant contributions to the development of KSEA.
The award ceremony took place during the 2015 US-Korea Conference on Science, Technology, and Entrepreneurship (UKC), which was held on July 30, 2015, at the Hyatt Regency Hotel in Atlanta, Georgia.
The UKC is the flagship conference of KSEA, which takes place every year, and covers science, engineering, technology, industry, entrepreneurship, and leadership. It attracts more than 1,200 participants from the US and Korea. The UKC 2015 was held on July 29-August 1, 2015.
President Kang has participated in UKC conferences over the past few years as a plenary speaker, addressing major issues in science and technology for both nations, and provided generous support for the activities of UKC and KSEA. He also promoted discussions and exchanges of professional knowledge in his field, microelectronics, by organizing fora and symposia.
He addressed the UKC 2015 as a plenary speaker with a speech entitled “Pursuing Excellence with a Servant’s Heart.” President Kang said that good leadership should bring out synergistic contributions from all constituents and achieve excellence under all circumstances. He mentioned one example of good leadership, known as humble leadership, and explained how such leadership played an important role in the development of scientific breakthroughs, such as the world’s premier high-end microprocessor chip sets first produced by his team under extremely high pressure.
2015.08.05 View 6465 -
Dr. Se-Jung Kim Receives the Grand Prize at the International Photo and Image Contest on Light
Dr. Se-Jung Kim of the Physics Department at KAIST received the Grand Prize at the 2015 Photo and Image Contest of the International Year of Light and Light-based Technologies.
The United Nations has designated the year 2015 as the International Year of Light and Light-based Technologies.
The Optical Society of Korea celebrated the UN’s designation by hosting an international photo and image contest on the theme of light and optics related technology.
Dr. Kim presented a photo of images taken from a liquid crystal, which was entitled “A Micro Pinwheel.” She took pictures of liquid crystal images with a polarizing microscope and then colored the pictures. The liquid crystal has self-assembled circle domain structures, and each domain can form vortex optics. Her adviser for the project is Professor Yong-Hoon Cho of the Physics Department.
Her work was exhibited during the annual conference of the Optical Society of Korea, which was held on July 13-15, 2015 at Gyeong-Ju Hwabaek International Convention Center. It will also be exhibited at the National Science Museum in Gwacheon and the Kim Dae-Jung Convention Center in Gwangju.
Picture: A Micro Pinwheel
2015.07.31 View 8537 -
Professor Suk-Joong Kang Receives the Richard Brook and Helmholtz Awards
Professor Suk-Joong Kang of KAIST’s Department of Materials Sciences and Engineering received the Richard Brook Award from the European Ceramic Society at its 14th conference held on June 21, 2015, in Toledo, Spain. The award is presented to the most distinguished academic or engineer in ceramics from a non-European country. Professor Kang gave the commemorative lecture after the award ceremony.
Professor Kang is an expert in the field of sintering and microstructural evolution in ceramics and metals. He suggested a new model for grain growth and identified the principles of microstructural evolution.
He also received the 2015 Helmholtz Fellow Award in June. The Helmholtz Association, the largest scientific organization in Germany, confers the award on outstanding senior scientists based outside Germany who have made great academic and research achievements in their fields.
Professor Kang said of the Brook Award, “It is such an honor to receive an award from an eminent global institution. I take this opportunity to thank my students and colleagues for their support, and I will work harder for my research.”
2015.07.20 View 5722 -
Novel Photolithographic Technology Enabling 3D Control over Functional Shapes of Microstructures
Professor Shin-Hyun Kim and his research team in the Department of Chemical and Biomolecular Engineering at KAIST have developed a novel photolithographic technology enabling control over the functional shapes of micropatterns using oxygen diffusion.
The research was published online in the March 13th issue of Nature Communications and was selected as a featured image for the journal.
Photolithography is a standard optical process for transferring micropatterns on to a substrate by exposing specific regions of the photoresist layer to ultraviolet (UV) light. It is used widely throughout industries that require micropatterns, especially in the semiconductor manufacturing industry.
Conventional photolithography relied on photomasks which protected certain regions of the substrate from the input UV light. Areas covered by the photomasks remain intact with the base layer while the areas exposed to the UV light are washed away, thus creating a micropattern. This technology was limited to a two-dimensional, disc-shaped design as the boundaries between the exposed and roofed regions are always in a parallel arrangement with the direction of the light.
Professor Kim’s research team discovered that: 1) the areas exposed to UV light lowered the concentration of oxygen and thus resulted in oxygen diffusion; and 2) manipulation of the diffusion speed and direction allowed control of the growth, shape and size of the polymers. Based on these findings, the team developed a new photolithographic technology that enabled the production of micropatterns with three-dimensional structures in various shapes and sizes.
Oxygen was considered an inhibitor during photopolymerization. Photoresist under UV light creates radicals which initialize a chemical reaction. These radicals are eliminated with the presence of oxygen and thus prevents the reaction. This suggests that the photoresist must be exposed to UV light for an extended time to completely remove oxygen for a chemical reaction to begin.
The research team, however, exploited the presence of oxygen. While the region affected by the UV light lowered oxygen concentration, the concentration in the untouched region remained unchanged. This difference in the concentrations caused a diffusion of oxygen to the region under UV light.
When the speed of the oxygen flow is slow, the diffusion occurs in parallel with the direction of the UV light. When fast, the diffusion process develops horizontally, outward from the area affected by the UV light. Professor Kim and his team proved this phenomenon both empirically and theoretically. Furthermore, by injecting an external oxygen source, the team was able to manipulate diffusion strength and direction, and thus control the shape and size of the polymer. The use of the polymerization inhibitors enabled and facilitated the fabrication of complex, three-dimensional micropatterns.
Professor Kim said, “While 3D printing is considered an innovative manufacturing technology, it cannot be used for mass-production of microscopic products. The new photolithographic technology will have a broad impact on both the academia and industry especially because existing, conventional photolithographic equipment can be used for the development of more complex micropatterns.” His newest technology will enhance the manufacturing process of three-dimensional polymers which were considered difficult to be commercialized.
The research was also dedicated to the late Professor Seung-Man Yang of the Department of Chemical and Biomolecular Engineering at KAIST. He was considered one of the greatest scholars in Korea in the field of hydrodynamics and colloids.
Picture 1: Featured Image of Nature Communications, March 2015
Picture 2: Polymers with various shapes and sizes produced with the new photolithographic technology developed by Professor Kim
2015.04.06 View 9685 -
Press Release on Piezoelectric Nanogenerators of ZnO with Aluminium Nitride Stacked Layers by the American Institute of Physics
The
American Institute of Physics (AIP) released a news article entitled “Zinc
Oxide Materials Tapped for Tiny Energy Harvesting Devices” on January 13, 2015.
The
article described the research led by Professor Giwan Yoon of the
Electrical Engineering Department at KAIST. It was published in the January
12, 2015 issue of Applied Physics Letters.
AIP publishes the journal. For the news release, please visit the
link below:
The American
Institute of Physics, January 13, 2015
“Zinc
Oxide Materials Tapped for Tiny Energy Harvesting Devices”
New research helps
pave the way toward highly energy-efficient zinc oxide-based micro energy
harvesting devices with applications in portable communications, healthcare and
environmental monitoring, and more
http://www.aip.org/publishing/journal-highlights/zinc-oxide-materials-tapped-tiny-energy-harvesting-devices
2015.02.04 View 31603 -
Distinguished Professor Sang Yup Lee Accepts an Honorary Professorship at Beijing University of Chemical Technology
Distinguished Professor Sang Yup Lee of the Department of Chemical and Biomolecular Engineering at KAIST has been appointed an honorary professor at Beijing University of Chemical Technology (BUCT). Founded in 1958, BUCT is one of the outstanding universities in mainland China, especially in chemistry studies.
In addition to the Chinese Academy of Sciences (2012), Shanghai Jiao Tong University (2013), Wuhan University (2014), and Hebei University of Technology (2014), this is the fifth honorary professorship Professor Lee has received from higher education institutions in China.
Professor Lee was recognized for his pioneering research in systems metabolic engineering of microorganisms necessary for the development of green chemical industries. He succeeded in producing succinic acid through bacterial fermentation and engineering plastic raw materials in the most effective and economical method for the first time in the world. Professor Lee also developed polylactic acid, a bio-based polymer that allows plastics to be produced through natural and renewable resources, as well as the microbial production of alkanes, an alternative to gasoline that can be produced from fatty acids.
Professor Lee has been actively working as a member of a group of global leaders supported by the World Economic Forum (WEF), serving as the Chairman of the Future of Chemicals, Advanced Materials & Biotechnology, Global Agenda Councils, WEF.
2014.11.13 View 10454 -
Wuhan University, China, Appoints Distinguished Professor Sang Yup Lee as Honorary Professor
Sang Yup Lee, Distinguished Professor of the Department of Chemical and Biomolecular Engineering at KAIST, has been appointed an honorary professor at Wuhan University in Hubei Province, China. This is the third time that Professor Lee has received an honorary professorship from Chinese academic institutions. The Chinese Academy of Sciences appointed him an honorary professor in 2012, and Shanghai Jia Tong University asked him to serve as an advisory professor in 2013, respectively.
Professor Lee was recognized for his pioneering research in systems metabolic engineering of microorganisms necessary for the development of green chemical industries. He succeeded in producing succinic acid through bacterial fermentation and engineering plastic raw materials in the most effective and economical method for the first time in the world. Professor Lee also developed polylactic acid, a bio-based polymer that allows plastics to be produced through natural and renewable resources, as well as the microbial production of alkanes, an alternative to gasoline that can be produced from fatty acids.
Professor Lee has been actively working as a member of a group of global leaders supported by the World Economic Forum (WEF), serving the Chairman of the Future of Chemicals, Advanced Materials & Biotechnology, Global Agenda Councils, WEF.
Wuhan University is a comprehensive and key national university selected by the Chinese government as a major recipient of state funding for research. It is also known as one of the most beautiful campuses in China.
2014.10.20 View 8580 -
Distinguished Professor Sang Yup Lee Gives Special Lecture at Tianjin University, China
Distinguished Professor Sang Yup Lee from the Department of Chemical and Biomolecular Engineering at KAIST gave a special lecture at Tianjin University, China, on September 12, 2014.
The university has invited prestigious scholars and scientists including Nobel Prize laureates from all around the world to their program called the "BeiYang Lecture Series."
Professor Lee said:
"The lecture series has invited many eminent global leaders such as Dr. Steven Chu, who received the Nobel Prize in Physics in 1997 and also served the 12th United States Secretary of Energy. It is a great honor to participate in the program as a speaker. The university told me that in recognition of my research in the development of sustainable biochemical industry through systems metabolic engineering, I was invited to speak.”
Professor Lee presented his speech entitled “Production of Chemical Materials through Microorganism Metabolic Systems Engineering” and took questions from the audience.
Professor Lee developed the world’s most efficient microorganism and bioprocess such as succinate, butanol, and engineering plastic raw materials. In recent years, he has succeeded in producing a small quantity of gasoline through converting in-vivo generated fatty acids.
2014.09.16 View 8401 -
A KAIST graduate named one of seven Microsoft Research Faculty Fellows for 2014
Yong-Yeol Ahn, a professor of the School of Informatics and Computing, Indiana University Bloomington (IUB), has been selected as one of the seven winners for the Microsoft Research Faculty Fellowship 2014. He received his Ph.D. in 2008 from KAIST.
Each year, since 2005, Microsoft Research has recognized innovative, promising new faculty members in computer science from a number of research institutions to join the ranks of Microsoft Research Faculty Fellows. The winners are awarded $200,000 grants to further advance their research.
For details, below please see a press release issued by IUB on June 12, 2014.
IU Bloomington Newsroom
Press Release, June 12, 2014
IU informaticist Y.Y. Ahn named one of seven Microsoft Research Faculty Fellows
http://news.indiana.edu/releases/iu/2014/06/yy-ahn-microsoft-research-faculty-fellow.shtml
2014.06.15 View 7569