research
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Prof. Sang-Yup Lee Founding Member of Board of Editors of mBop
Prof. Sang-Yup Lee of the Department of Chemical and Biomolecular Engineering at KAIST has been appointed as one of the founding board of editors of the mBio which will be launched next year, the university reported on Friday (Nov. 20).
mBio is the American Society for Microbiology"s first all-online, open access journal which will be launched in next May. According to the mBio website, the journal"s scope "will reflect the enormity of the microbial world, a highly interconnected biosphere where microbes interact with living and non-living matter to produce outcomes that range from symbiosis to pathogenesis, energy acquisition and conversion, climate change, geologic change, food and drug production, and even animal behavioral change."
Prof. Lee, LG Chem Chair Professor, is currently the Dean of the College of Life Science and Bioengineering and director of the Center for Systems and Synthetic Biotechnology. He received his B.S. in Chemical Engineering from Seoul National Univeristy in Korea and his M.S. and Ph.D. in Chemical Engineering from Northwestern University.
As of September 2009, he has published 298 journal papers and has more than 440 patents either registered or applied. Also, he has published 47 books/book chapters, "Systems Biology and Biotechnology of Escherichia Coli" being the latest.
His research interests are systems biology and biotechnology, industrial biotechnology, metabolic engineering, synthetic biology and nanobiotechnology. In particular, he has pioneered systems metabolic engineering, which integrates systems biology with metabolic engineering, for the development of micropoganisms possessing superior properties for industrial applications.
2009.11.20 View 11640 -
Prof. Lee"s Team Pioneers Biotechnological Production of Chemical Using Renewable Materials
A research team led by Prof. Sang-Yup Lee of the Bio and Brain Engineering Department at KAIST has succeeded in engineering the bacterium E. coli to produce the industrial chemical putrescine, university authorities said on Monday (Aug. 31).
Putrescine, a four carbon chain diamine, is an important platform chemical with a wide range of applications for the pharmaceutical, agrochemical and chemical industries. It is currently used to synthesize nylon-4,6, a widely used engineering plastic.
The research result, published in the Biotechnology and Bioengineering journal, proviDrdes a renewable alternative to the traditional process using fossil fuels.
Currently the production of putrescine on an industrial scale relies on chemical synthesis, which requires non-renewable petrochemicals and expensive catalyst systems. This process is highly toxic and flammable with potentially severe repercussions for both the environment and human health.
"For the first time we have developed a metabolically engineered E. coli strain that efficiently produces putrescine," said Professor Lee. "The development of a bio-refinery for chemicals and materials is very important in a world where dependency on fossil fuels is an increasing concern."
The team developed a strain of E.coli capable of producing putrescine through metabolic engineering. This is where a cell"s metabolic and regulatory networks are enhanced in order to increase production of a needed material.
First the team weakened or deleted competing metabolic pathways within the E. coli strain before deleting pathways which cause putrescine degradation. They also amplified the crucial enzyme Spec C, which converts the chemical ornithine into putrescine. Finally the putrescine exporter, which allows excretion of intracellularly made putrescine, was engineered while a global regulator was engineered to further increase the concentration of putrescine. The final result of this process was an engineered E.coli strain which produced 24.2 g of putrescine per litre.
However, as it was believed that putrescine is toxic to microorganisms the team had to study putrescine tolerance in E.coli before it could be engineered to overproduce the chemical to the levels needed for industrial production.
The results revealed that E. coli can tolerate at least 0.5 M of putrescine, which is tenfold higher than the usual concentration in the cell. This level of tolerance was an important surprise as it means that E. coli can be engineered to overproduce putrescine to industrially competitive levels.
"The previously expected toxicity of putrescine may explain why its microbial production has been overlooked," said Lee. "Now a metabolically engineered E. coli strain has been developed which is capable of efficiently producing putrescine using renewable methods to an industrial level. This metabolic engineering framework should be useful for developing metabolically engineered microorganisms for the efficient production of other chemicals from renewable resources," he added.
2009.09.01 View 12946 -
KAIST College of Life Sciences and Bioengineering Signs MOU with Harvard
KAIST’s College of Life Sciences and Bioengineering recently signed a memorandum of understanding (MOU) with Harvard University’s Center for Brain Science on July 20, which will allow for joint research and exchange in researchers between the two institutions.
Headed by Director Kenneth Blum, Harvard’s Center for Brain Science leads the world in brain-related research. The new MOU will allow for research cooperation, exchanges of professors, researchers, and students, joint usage of infrastructure and research materials, and finally, sharing of research assignments.
The Dean of the College of Life Sciences and Bioengineering Sang Yup Lee, who concerted efforts to form the MOU said, “This agreement will bring together two of the world’s leading brain-related research teams, and I hope that combining their expertise will bring great advances in brain science and engineering.
KAIST’s College of Life Science and Bioengineering, which is known for its creative interdisciplinary research, is producing exemplary research results in the field of brain science from its Biological Sciences and Bio and Brain Engineering departments.
In addition to cooperation with Harvard, KAIST has also formed partnerships with Emory University, Japan’s RIKEN Brain Institute, and Germany’s Max Planck Institute. Not only does it have a worldwide network pertaining to brain research, but KAIST has also engaged in cooperative research with prominent domestic institutions such as, Asan Medical Center, the Korea Research Institute of Bioscience and Biotechnology, the Korea Research Institute of Standards and Science, and the SK Corporation. Through these connections, KAIST has managed to lead in mutually cooperative brain interdisciplinary research.
2009.08.10 View 14620 -
KAIST Professor Sang-Yup Lee Chair of International Metabolic Engineering Conference Due Next Year
KAIST distinguished professor Sang-Yup Lee was named to chair the 17th Metabolic Engineering Conference which will convene on Jeju Island, Korea, next year, under the theme of "Metabolic Engineering for Green Growth." It was decided at the 16th Biochemical Engineering Conference held in Burlington, Vermont, on July 5-9.
Metabolic Engineering Conference in 2010 will not only involve presentations and discussions about metabolic engineering, but will inaugurate the “World Council on Industrial Biotechnology,” which will bring together global corporations and the world’s experts in industrial biochemical engineering, according to sources at KAIST.
A KAIST official commented, “The fact that the Metabolic Engineering Conference is to be held here [in Korea] proves that Korea is being acknowledged as a key player in this field.”
As the world faces the depletion of fossil fuels and environmental pollution, nations are showing increasing interest in industrial biochemical alternatives, such as microscopic organisms or new chemicals, to solve their problems. In addition, efficient production of biochemical materials and bio-fuels using microbes is deemed vital for the future.
“The Korean government has become a model to other countries thanks to its leadership in carrying out the ‘Green Growth’ policy,” Professor Sang-Yup Lee said. He stated that KAIST is recognized for its research in advanced biochemical material and fuel production methods.
“Green Growth,” a concept first developed by ESCAP, the UN agency working for social and economic cooperation in Asia and the Pacific, aims to achieve sustainable economic growth without destroying the environment.
Ref. Department of Biochemical Engineering, Metabolic and BioMolecular Engineering Lab, KAIST
2009.07.17 View 12605 -
Prof. Song Develops Nano-Structure to Enhance Power of Rechargeable Lithium-ion Battery
A team of scientists led by Prof. Hyun-Joon Song of the Department of Chemistry, KAIST, developed a nano-structure that could increase the power of rechargeable lithium-ion batteries, university sources said on Monday (Feb. 16).
The research team found that a nano-structured material using copper oxide (CuO) could produce lithium-ion batteries with some 50 percent more capacity than conventional products. The study was published in the online edition of peer-review journal Advanced Materials.
In rechargeable lithium-ion batteries, lithium ions move between the battery"s anode and cathode. The high-energy density of the batteries led to their common use in consumer electronics products, expecially portable devices. Their demand in automotive and aerospace applications is growing, and nano-structured, or nano-enabled batteries are emerging as the new generation of lithium-ion batteries for their edge in recharging time, capacity and battery life.
Graphite has been a popular material for cathodes in lithium-ion batteries. However, graphite cathodes are also blamed for lost capacity due to their consumption of lithium ions, which are linked to shorter battery life.
As such, scientists have been looking for materials that could replace graphite in cathodes, and silicon and metal oxide have been studied as possible alternatives.
2009.02.17 View 11274
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KAIST Scientists Creates Transparent Memory Chip
--See-Through Semis Could Revolutionize Displays
A group of KAIST scientists led by Prof. Jae-Woo Park and Koeng-Su Lim has created a working computer chip that is almost completely clear -- the first of its kind.
The new chip, called "transparent resistive random access memory (TRRAM), is similar in type to an existing technology known as complementary metal-oxide semiconductor (CMOS) memory -- common commercial chips that provide the data storage for USB flash drives and other devices. Like CMOS devices, the new chip provides "non-volatile" memory, meaning that it stores digital information without losing data when it is powered off. Unlike CMOS devices, however, the new TRRAM chip is almost completely clear.
The paper on the new technology, entitled "Transparent resistive random access memory and its characteristics for non-volatile resistive switching," was published in the December issue of the Applied Physics Letters (APL), and the American Institute of Physics, the publisher of APL, issued a press release about this breakthrough.
"It is a new milestone of transparent electronic systems," says researcher Jung-Won Seo, who is the first author of the paper. "By integrating TRRAM devices with other transparent electronic components, we can create a totally see-through embedded electronic system."
Technically, TRRAM devices rely upon an existing technology known as resistive random access memory (RRAM), which is already in commercial development for future electronic data storage devices. RRAM is built using metal oxide materials between equally transparent electrodes and substrates.
According to the research team, TRRAM devices are easy to fabricate and may be commercially available in just 3-4 years.
"We are sure that TRRAM will become one of alternative devices to current CMOS-based flash memory in the near future after its reliability is proven and once any manufacturing issues are solved," says Prof. Jae-Woo Park, who is the co-author on the paper. He adds that the new devices have the potential to be manufactured cheaply because any transparent materials can be utilized as substrate and electrode. They also may not require incorporating rare elements such as Indium.
2008.12.17 View 15898 -
Method to Synthesize New Lithium Ion Battery Cathode Material Identified
A KAIST research team headed by Prof. Do-Kyung Kim at the Department of Materials Science and Engineering developed a technology to synthesize a new lithium ion battery spinel cathode which is regarded as a core part of hybrid and lithium battery cars.
The research was conducted in collaboration with a research team of Prof. Yi Cui at Stanford University"s Department of Chemistry. Their findings were introduced in the November issue of Nano Letters, one of the leading academic journals in nano-science.
The newly synthesized lithium ion battery spinel cathode known as spinel LiMn2O4 nanorods is attracting interests as an alternative cathode material since it is a low-cost, environmentally friendly substance for Li-ion battery cathodes. Its raw material is also highly available.
Lithium ion batteries with high energy and power density are important for consumer electronic devices, portable power tools, and vehicle electrification. LixCoO2 is a commonly used cathode material in commercial lithium iron batteries. However, the high cost, toxicity, and limited abundance of cobalt have been recognized to be disadvantageous.
2008.11.20 View 11836 -
KAIST Team Identifies Nano-scale Origin of Toughness in Rare Earth-added Silicon Carbide
A research team led by Prof. Do-Kyung Kim of the Department of Materials Science and Engineering of KAIST has identified the nano-scale origin of the toughness in rare-earth doped silicon carbide (RE-SiC), university sources said on Monday (Oct. 6).
The research was conducted jointly with a U.S. team headed by Prof. R. O. Ritchie of the Department of Materials Science and Engineering, University of California, Berkeley.
The findings were carried in the online edition of Nano Letters published by the American Chemical Association.
Silicon carbide, a ceramic material known to be one of the hardest substances, are potential candidate materials for many ultrahigh-temperature structural applications. For example, if SiC, instead of metallic alloys, is used in gas-turbine engines for power generation and aerospace applications, operating temperatures of many hundred degrees higher can be obtained with a consequent dramatic increase in thermodynamic efficiency and reduced fuel consumption. However, the use of such ceramic materials has so far been severely limited since the origin of the toughness in RE-SiC remained unknown thus far.
In order to investigate the origin of the toughness in RE-SiC, the researchers attempted to examine the mechanistic nature of the cracking events, which they found to occur precisely along the interface between SiC grains and the nano-scale grain-boundary phase, by using ultrahigh-resolution transmission electron microscopy and atomic-scale spectroscopy. The research found that for optimal toughness, the relative elastic modulus across the grain-boundary phase and the interfacial fracture toughness are the most critical material parameters; both can be altered with appropriate choice of rare-earth elements.
In addition to identifying the nano-scale origin of the toughness in RE-SiC, the findings also contributed to precisely predicting how the use of various rare-earth elements lead to difference in toughness.
University sources said that the findings will significantly advance the date when RE-SiC will replace metallic alloys in gas-turbine engines for power generation and aerospace applications.
2008.10.08 View 13938 -
Prof. Sang-Yup Lee Receives Merck Award for Metabolic Engineering
Prof. Sang-Yup Lee of KAIST"s Department of Chemical and Biomolecular Engineering has been chosen as the winner of the 2008 Merck Award for Metabol;ic Engineering established by the world"s leading pharmaceutical and chemical company Merck, KAIST officials said Tuesday, Sept. 16.
The Distinguished Professor of KAIST and LG Chem Chair Professor will receive the award on Sept. 18 during the 7th Metabolic Engineering convention now underway at Puerto Vallarta, Mexico. Prof. Lee will give a commemorative lecture, titled "Systems Metabolic Engineering for Chemicals," at the biannual academic conference. Prof. Lee is the fourth to win the coveted award which is given to the world"s top expert in metabolic engineering with outstanding achievements in the field.
Prof. Lee, 44, who graduated from Seoul National University and earned his master"s and doctoral degrees in chemical engineering from Northwestern University of the United States, is now the dean of the College of Life Science and Bioengineering, KAIST. Since 1994, he has served as the head of the Metabolic and Biomolecular Engineering National Research Laboratory, director of the BioProcess Engineering Center, Director of the Bioinformatics Research Center and Co-Director of the Institute for the BioCentury in KAIST.
Prof. Lee said he was receiving the Merck award "as a representative of KAIST graduates, students and researchers" who have worked with him at the Metabolic Engineering Lab. He added he was happy to see the outcome of bioengineering development projects supported by the Ministry of Education, Science and Technology over the past years was now being recognized by the world"s leading scientific society with the Merck Award.
Metabolic engineering, the art of optimizing genetic and regulatory processes within cells to increase the cell"s production of a certain substance, develops technologies that hold the key to the resolution of the world"s energy, food and environmental problems. The indispensible technology in bioengineering can be applied to the production of biomass to obtain alternative fuel.
Prof. Lee has actively participated in publishing such academic periodicals as Biotechnology Journal (as chief editor), Biotechnology and Bioengineering (deputy editor) and Metabolic Engineering (a member of the editorial committee).
2008.09.17 View 14485 -
Prof. Lee Appointed to Advisory Board of the U.S. Joint BioEnergy Institute
Prof. Sang-Yup Lee of the Department of Chemical and Biomolecular Engineering, KAIST, has been appointed as a member of the scientific advisory board of the Joint BioEnergy Institute under the wing of the U.S. Department of Energy, university authorities said on Monday (Aug. 4).
The Joint BioEnergy Institute (JBEI) is a scientific partnership in the San Francisco Bay area, California, led by Lawrence Berkeley National Laboratory (Berkeley Lab). Its partner organizations include the Sandia National Laboratories, the University of California in Berkeley, UC Davis, the Carnegie Institution for Science and the Lawrence Livermore National Laboratory.
JBEI
2008.08.07 View 11680 -
KAIST Professors Article Featured as Cover Thesis of Biotechnology Journal
An article authored by a research team of Prof. Sang-yup Lee at the Department of Chemical and Biomolecular Engineering and Dr. Jin-Hwan Park at the KAIST Institute for the BioCentury has been featured as the cover thesis of the August 2008 issue of Trends in Biotechnology.
The paper, titled "General strategy for strain improvement by means of systems metabolic engineering," focuses on the application of systems biology for the development of strains and illustrates future prospects. Trends in Biotechnology, published by Cell Press, is one of the most prestigious review journals in the field.
Jin-Hwan Park, the primary author of the research thesis, said that the KAIST team"s research work was expected to provide substantial help to researchers involved in biotechnology industry.
The strategy has been established on the basis of the experiences gained in the actual microbial production process using the systems biology methods which his research team has recently worked on, Prof. Park said.
2008.07.24 View 13895
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KAIST, GS Caltex Jointly Develop New Bacteria to Produce Biobutanol
KAIST and GS Caltex, Korea"s second-largest refiner, have jointly developed a new strain of bacteria to produce biobutanol, which is regarded as a promising next-generation biofuel, KAIST authorities said on Monday (June 2).
A research team led by Prof. Sang-Yup Lee of the Chemical and Biomolecular Engineering Department and researchers of GS Caltex succeeded in developing an improved strain of bacteria which enables to produce a large amount of biobutanol in the process of fermenting biomass. The research team has applied for international patent for the new technology.
Biomass refers to living and recently dead biological material that can be used as fuel or for industrial production. It usually refers to plant matter grown for use as biofuel, but it also includes plant or animal matter used for production of fibers, chemicals or heat.
In the 1970s and 1980s when scientists began researching the possibilities of alternative fuels, bacteria were used in the process of fermenting biomass. This ABE (acetone, butanol, ethanol) fermentation process yields butanol, acetone, and ethanol in a ratio of 6:3:1, respectively. Acetone produced in this process is not usable.
The newly developed technology to produce biobutanol has an advantage of lowering production cost by eliminating the process to separate acetone from butanol. This has been made possible by improving the bacteria used for the fermentation in metabolic engineering terms, and producing butanol and ethanol only in a ratio of 6:1, while curbing the generation of acetone.
In comparison with bioethanol, also a biofuel mixture which is currently under widespread use in some countries, butanol is more easily transported with gasoline and diesel through pipelines because of its lower tendency to separate from the fuel when contaminated with water. Butanol is also less corrosive than ethanol, another reason its transport through pipeline is preferable.
Global interest in full utilization of biomass and development of other alternative energy including biobutanol has deepened in recent years, as crude oil prices have skyrocketed to record levels and climate changes resulting from the excessive use of fossil fuel have been causing various problems around the world.
2008.06.04 View 11776