research
-
KAIST and Coverity sign MOU for the Analysis of Static in Software
KAIST signed an ‘Interdisciplinary Cooperation in Software Static Analysis Agreement’ with America’s Coverity (representative: Anthony Bettencourt) on the 24th of February.
Dignitaries like Dean of the department of Computer Science of KAISt Choi Gee Son and Andy Chow CTO of Coverity attended the ceremony.
The agreement will allow the application of Coverity’s family of integral product software to research and education at KAIST. This will strengthen KAIST’s ability to develop software and be used in the education of software quality related subjects.
CTO of Coverity Andy Chow had a special seminar for KAIST researches and students after the signing on the topic of ‘Understanding the Present Condition of Static Analysis Technology and its Future’.
Rich Cerruto, in charge of Coverity in Asia, commented that the software developed by Coverity is being used by Samsung, LG electronics, and other domestic companies carrying out R&D for product quality improvement and that he hopes that through this agreement the development of quality-driven software will be educated in a structural manner in the domestic education market together with KAIST.
Coverity has signed MOU with other major universities like Stanford University, Carnegie Mellon University, and UC Berkeley but KAIST is the first in Asia to sign.
2011.03.02 View 10759 -
Nanowerk Spotlight: Bacteria as environmentally friendly nanoparticle factories, Sep. 24, 2010
The Nanowerk.com is a leading portal site for nanotechnology and nanosciences, which runs a daily news section called “Spotlight.” On September 24, 2010, the Spotlight published an article on the latest developments of the research by a KAIST team headed by Distinguished Professor Sang-Yup Lee of the Chemical and Bimolecular Engineering Department. For the article, please click the link below:
Nanowerk Spotlight: Bacteria as environmentally friendly nanoparticle factories, Sep. 24, 2010
By Michael Berger.
http://www.nanowerk.com/spotlight/spotid=18188.php
2010.09.25 View 10011
-
"Supersolidity flows back," Nature, September 2, 2010
Supersolidity, discovered for the first time in 2004 by two physicists—one of them is Professor Eun-Seong Kim from the Department of Physics, KAIST—was discussed once again in the September 2, 2010 issue of Nature, an internationally well-known science journal.
The article mentioned “supersolidity” as one of the rare examples of quantum effects on a macroscopic scale, together with “superconductivity” and “superfluidity.” The phenomenon of supersolidity was evidenced by Professor Kim and his colleague through an experiment of placing helium-4 in a torsional oscillator under a low temperature.
The phenomenon, however, has been in debate among scientists in the physics community since the discovery, and Professor Kim has recently released his research results to further support his claim. For the full article, please click the link below:
http://www.nature.com/news/2010/100902/full/news.2010.443.html.
2010.09.08 View 9218
-
Science News Issued on September 11, 2010: A matter of solidity
Science News, a bi-weekly news magazine of the Society for Science & the Public, published an extensive article on the issue of “supersolidity” discovered in helium-4.
Professor Eun-Seong Kim of the Physics Department, KAIST, is one of the scientists who discovered the phenomenon through an experiment of solid helium using a device called a torsional oscillator.
For the entire article, please click the link of
http://www.sciencenews.org/view/feature/id/62642/title/A_matter_of_solidity.
2010.09.02 View 10156
-
An internationally renowned academic journal published the research result produced by a KAST research team on its cover.
Fc DAAP VEGF-Trap
Photograph showing the gross features of tumor growth along the mesentery-intestinal border. T: tumor. Scale bars represent 5 mm.
Professor Gou-Young Koh of the Biological Sciences Department, KAIST, and his research team published their research result in Cancer Cell, a peer-review scientific journal, as a cover article dated August 17, 2010. It is the first time for the journal to pick up a paper written by a Korean research team and publish it as the cover.
It has been known that a vascular growth factor (VEGF) is closely related to the growth of a tumor. The research team recently discovered that in addition to VEGF, another growth factor, angiopoietin-2 (Ang2), is also engaged with the increase of tumors.
Professor Koh said, “VEGF and the angiopoietins play critical roles in tumor progression and metastasis, and a single inhibitor targeting both factors have not been available.”
The team led by Professor Koh has developed a double anti-angiogenic protein (DAAP) that can simultaneously bind VEGF-A and the angiopoietins and block their actions.
Professor Koh said in his paper, “DAAP is a highly effective molecule for regressing tumor angiogenesis and metastasis in implanted and spontaneous solid tumor; it can also effectively reduce ascites formation and vascular leakage in an ovarian carcinoma model. Thus, simultaneous blockade of VEGF-A and angiopoietins with DAAP is an effective therapeutic strategy for blocking tumor angiogenesis, metastasis, and vascular leakage.”
So far, cancer patients have received Avastin, anticancer drug, to inhibit VEGF, but the drug has not successfully restrained the growth of cancer tumors and brought to some of the patients with serious side effects instead.
Professor Koh said, “DAAP will be very effective to control the expansion of tumor growth factors, which will open up a new possibility for the development of more helpful cancer medicine with low side effects.”
2010.08.20 View 11429 -
Bioengineers develop a new strategy for accurate prediction of cellular metabolic fluxes
A team of pioneering South Korean scientists has developed a new strategy for accurately predicting cellular metabolic fluxes under various genotypic and environmental conditions. This groundbreaking research is published in the journal Proceedings of the National Academy of Sciences of the USA (PNAS) on August 2, 2010.
To understand cellular metabolism and predict its metabolic capability at systems-level, systems biological analysis by modeling and simulation of metabolic network plays an important role. The team from the Korea Advanced Institute of Science and Technology (KAIST), led by Distinguished Professor Sang Yup Lee, focused their research on the development of a new strategy for more accurate prediction of cellular metabolism.
“For strain improvement, biologists have made every effort to understand the global picture of biological systems and investigate the changes of all metabolic fluxes of the system under changing genotypic and environmental conditions,” said Lee. The accumulation of omics data, including genome, transcriptome, proteome, metabolome, and fluxome, provides an opportunity to understand the cellular physiology and metabolic characteristics at systems-level. With the availability of the fully annotated genome sequence, the genome-scale in silico (means “performed on computer or via computer simulation.”) metabolic models for a number of organisms have been successfully developed to improve our understanding on these biological systems. With these advances, the development of new simulation methods to analyze and integrate systematically large amounts of biological data and predict cellular metabolic capability for systems biological analysis is important.
Information used to reconstruct the genome-scale in silico cell is not yet complete, which can make the simulation results different from the physiological performances of the real cell. Thus, additional information and procedures, such as providing additional constraints (constraint: a term to exclude incorrect metabolic fluxes by restricting the solution space of in silico cell) to the model, are often incorporated to improve the accuracy of the in silico cell.
By employing information generated from the genome sequence and annotation, the KAIST team developed a new set of constraints, called Grouping Reaction (GR) constraints, to accurately predict metabolic fluxes. Based on the genomic information, functionally related reactions were organized into different groups. These groups were considered for the generation of GR constraints, as condition- and objective function- independent constraints. Since the method developed in this study does not require complex information but only the genome sequence and annotation, this strategy can be applied to any organism with a completely annotated genome sequence.
“As we become increasingly concerned with environmental problems and the limits of fossil resources, bio-based production of chemicals from renewable biomass has been receiving great attention. Systems biological analysis by modeling and simulation of biological systems, to understand cellular metabolism and identify the targets for the strain improvement, has provided a new paradigm for developing successful bioprocesses,” concluded Lee. This new strategy for predicting cellular metabolism is expected to contribute to more accurate determination of cellular metabolic characteristics, and consequently to the development of metabolic engineering strategies for the efficient production of important industrial products and identification of new drug targets in pathogens.”
2010.08.05 View 12375 -
Native-like Spider Silk Produced in Metabolically Engineered Bacterium
Microscopic picture of 285 kilodalton recombinant spider silk fiber
Researchers have long envied spiders’ ability to manufacture silk that is light-weighted while as strong and tough as steel or Kevlar. Indeed, finer than human hair, five times stronger by weight than steel, and three times tougher than the top quality man-made fiber Kevlar, spider dragline silk is an ideal material for numerous applications. Suggested industrial applications have ranged from parachute cords and protective clothing to composite materials in aircrafts. Also, many biomedical applications are envisioned due to its biocompatibility and biodegradability.
Unfortunately, natural dragline silk cannot be conveniently obtained by farming spiders because they are highly territorial and aggressive. To develop a more sustainable process, can scientists mass-produce artificial silk while maintaining the amazing properties of native silk? That is something Sang Yup Lee at the Korea Advanced Institute of Science and Technology (KAIST) in Daejeon, the Republic of Korea, and his collaborators, Professor Young Hwan Park at Seoul National University and Professor David Kaplan at Tufts University, wanted to figure out. Their method is very similar to what spiders essentially do: first, expression of recombinant silk proteins; second, making the soluble silk proteins into water-insoluble fibers through spinning.
For the successful expression of high molecular weight spider silk protein, Professor Lee and his colleagues pieced together the silk gene from chemically synthesized oligonucleotides, and then inserted it into the expression host (in this case, an industrially safe bacterium Escherichia coli which is normally found in our gut). Initially, the bacterium refused to the challenging task of producing high molecular weight spider silk protein due to the unique characteristics of the protein, such as extremely large size, repetitive nature of the protein structure, and biased abundance of a particular amino acid glycine. “To make E. coli synthesize this ultra high molecular weight (as big as 285 kilodalton) spider silk protein having highly repetitive amino acid sequence, we helped E. coli overcome the difficulties by systems metabolic engineering,” says Sang Yup Lee, Distinguished Professor of KAIST, who led this project. His team boosted the pool of glycyl-tRNA, the major building block of spider silk protein synthesis. “We could obtain appreciable expression of the 285 kilodalton spider silk protein, which is the largest recombinant silk protein ever produced in E. coli. That was really incredible.” says Dr. Xia.
But this was only step one. The KAIST team performed high-cell-density cultures for mass production of the recombinant spider silk protein. Then, the team developed a simple, easy to scale-up purification process for the recombinant spider silk protein. The purified spider silk protein could be spun into beautiful silk fiber. To study the mechanical properties of the artificial spider silk, the researchers determined tenacity, elongation, and Young’s modulus, the three critical mechanical parameters that represent a fiber’s strength, extensibility, and stiffness. Importantly, the artificial fiber displayed the tenacity, elongation, and Young’s modulus of 508 MPa, 15%, and 21 GPa, respectively, which are comparable to those of the native spider silk.
“We have offered an overall platform for mass production of native-like spider dragline silk. This platform would enable us to have broader industrial and biomedical applications for spider silk. Moreover, many other silk-like biomaterials such as elastin, collagen, byssus, resilin, and other repetitive proteins have similar features to spider silk protein. Thus, our platform should also be useful for their efficient bio-based production and applications,” concludes Professor Lee.
This work is published on July 26 in the Proceedings of the National Academy of Sciences (PNAS) online.
2010.07.28 View 16774 -
The 8th International Conference on Metabolic Engineering was held on June 13-18, 2010 in Jeju Island, South Korea.
From left to right, top row: Distinguished Professor and the conference chair Sang Yup Lee, Sang-Hyup Kim - Secretary to the President of Korea, Dr. Jay Keasling, Dr. Greg Stephanopoulos. Left to right, bottom row: Dr. William Provine, Dr. Terry Papoutsakis, Dr, Jens Nielsen, Dr. Lars Nielsen.
The importance of industrial biotechnology that produces chemicals and materials from renewable biomass is increasing due to climate change and the dearth of natural resources. Industrial biotechnology refers to a technology that allows sustainable bio-based production of chemicals and materials that could enrich human"s lives using microorganisms. This is where metabolic engineering comes into play for successful application of microorganisms, in which they are engineered in our intended way for improved production capability.
The 8th International Conference on Metabolic Engineering, the longest running conference of its kind, was held on June 13-18, 2010 at the International Convention Center in Jeju Island, South Korea. Distinguished Professor Sang Yup Lee of KAIST, Dean of College of Life Science and Bioengineering and Co-Director of Institute for the BioCentury, chaired the conference with the main theme of "metabolic engineering for green growth."
With 300 delegates selected by the committee, papers on production of biofuels, chemicals, biopolymers, and pharmaceutics and the development of fundamental metabolic engineering techniques were presented at the conference along with examples of successful commercialization of products developed by several global companies.
Sang Hyup Kim, Secretary to the President of Korea, gave an opening plenary lecture entitled "Korean green growth initiative," to inform experts from around the globe of the leadership on green growth in Korea. Young Hoon Park, President of Korea Research Institute of Bioscience and Biotechnology (KRIBB, Korea) delivered his congratulatory address.
Sang Hyup Kim said, "Hosting an international conference in Korea on metabolic engineering, which forms a core technology necessary for the development of environmentally friendly processes for producing chemicals and biofuels from renewable biomass, is very meaningful as green growth is a big issue around the globe. This is a great chance to show the excellence of Korea"s green growth associated technology to experts in metabolic engineering and industrial biotechnology."
A total of 47 invited lectures in this conference included recent and important topics, for instance, "Synthetic biology for synthetic fuels" by Dr. Jay Keasling from the Joint BioEnergy Institute (USA), "Microbial oil production from renewable feedstocks" by Dr. Greg Stephanopoulos from MIT (USA), "Yeast as a platform cell factory for production of fuels and chemicals" by Dr. Jens Nielsen from Chalmers University (Sweden), "Mammalian synthetic biology - from tools to therapies" by Dr. Martin Fussengger from ETH (Switzerland), "Building, modeling, and applications of metabolic and transcriptional regulatory networks at a genome-scale" by Dr. Bernhard Palsson from the University of California - San Diego (USA), "Genome analysis and engineering Eschericha coli for sucrose utilization" by Dr. Lars Nielsen from the University of Queensland (Australia), "Artificial microorganisms by synthetic biology" by Dr. Daniel Gibson from JCVI (USA), and "Metabolomics and its applications" by Dr. Masaru Tomita from Keio University (Japan). From Korea, Dr. Jin Hwan Park from the research group of Dr. Sang Yup Lee at KAIST presented "Systems metabolic engineering of Escherichia coli for amino acid production," and Dr. Ji Hyun Kim from KRIBB presented "Genome sequencing and omics systems analysis of the protein cell factory of Escherichia coli".
Global companies involved in biorefinery presented their recent research outcomes with emphasis on commercialized technologies. They included "Metabolic and process engineering for commercial outcomes" by Dr. William Provine from DuPont (USA), "Direct production of 1,4-butanediol from renewable feedstocks" by Dr. Mark Burk from Genomatica (USA), "Development of an economically sustainable bioprocess for the production of bio 1,2-propanediol" by Dr. Francis Voelker from Metabolic Explorer (France), "Biotechnology to the bottom-line: low pH lactic acid production at industrial scale" by Dr. Pirkko Suominen from Cargill (USA), "Bioisoprene™: traditional monomer, traditional chemistry, sustainable source" by Dr. Gregg Whited from Danisco (USA) and "Efficient production of pharmaceuticals by engineered fungi" by Dr. Roel Bovenberg from DSM (Netherlands).
This biennial conference also presented the International Metabolic Engineering Award (expanded version of the previous Merck Metabolic Engineering Award) to the best metabolic engineer in the world. The 2010 International Metabolic Engineering Award went to Dr. E. Terry Papoutsakis from the University of Delaware (USA) who has contributed to the production of biobutanol through the metabolic engineering of Clostridia in the last three decades, and he gave an award lecture. Dr. Sang Yup Lee, the current chair of the upcoming conference, was the previous recipient of this award at the last metabolic engineering conference in 2008.
In addition to the invited lectures, a total of 156 carefully selected poster papers were chosen for presentation, and awards were presented to the best posters after rigorous review by the committee members. Such awards included "The 2010 Metabolic Engineering Best Poster Award" and the "2010 Young Metabolic Engineer Award" from the Metabolic Engineering conference, and prestigious international journal awards, including "Wiley Biotechnology Journal Best Poster Award", "Wiley Biotechnology and Bioengineering Best Poster Award" and "Elsevier Metabolic Engineering Best Paper Award." Dr. Catherine Goodman, a senior editor of Nature Chemical Biology, also presented the "Nature Chemical Biology Best Poster Award on Metabolic Engineering."
Regarding this conference, Dr. Sang Yup Lee, the conference chair, said, "This conference is the best international conference in the field of metabolic engineering, which is held every two years, and Korea is the first Asian country to host it. All the experts and students spend time together from early breakfast to late poster sessions, which is a distinct feature of this conference. Although the number of delegates had typically been limited to 200, around 300 delegates were selected this year to accept more attendees from many people who have been interested in metabolic engineering. Also, it is very fitting that "green growth" is the main topic of this conference because Korea is playing a key role in this field. I"m grateful to the Lotte Scholarship Foundation, COFCO, GS Caltex, Bioneer, US DOE, US NSF, Daesang, CJ Cheiljedang, Genomatica and DuPont who provided us with generous financial support that allowed the successful organization of this conference."
The conference was organized by the Systems Biology Research Project Team supported by the Ministry of Eduction, Science and Technology (MEST), Microbial Frontier Research Project Group, World Class University Project Group at KAIST, Institute for the BioCentury at KAIST, Korean Society for Biotechnology and Bioengineering, and the Engineering Conference International (ECI) of the United States.
Inquiries: Professor Sang Yup Lee (+82-42-350-3930), industrialbio@gmail.com
2010.06.25 View 17860 -
Professor Eun-Seong Kim and his research staff observed the phenomena of hysteresis and relaxation dynamics from supersolid Helium
Professor Eun-Seong Kim and his research staff observed the phenomena of hysteresis and relaxation dynamics from supersolid Helium.
Their research paper was published in Nature Physics for the issue of April 2010.
If we take Helium 4 and cool it down at temperatures below 2.176 Kelivin, liquid helium 4 undergoes a phase transition and becomes superfluid with a zero viscosity. The superfluidity was observed in solid helium through an experiment performed by researchers of Pennsylvania State University in 2004. One of the researchers then was Professor Eun-Seong Kim in the Department of Physics, KAIST.
Professor Kim and his research staff, Hyung-Soon Choi, Ph.D., recently published their research results in Nature Physics (April 2010), a highly esteemed journal in the field, on the phenomena of hysteresis and relaxation dynamics observed in supersolid Helium.
For the paper, please download the attached .pdf file.
Nature Physics link: http://www.nature.com
2010.04.13 View 11986 -
New drug targeting method for microbial pathogens developed using in silico cell
A ripple effect is expected on the new antibacterial discovery using “in silico” cells
Featured as a journal cover paper of Molecular BioSystems
A research team of Distinguished Professor Sang Yup Lee at KAIST recently constructed an in silico cell of a microbial pathogen that is resistant to antibiotics and developed a new drug targeting method that could effectively disrupt the pathogen"s growth using the in silico cell.
Hyun Uk Kim, a graduate research assistant at the Department of Chemical and Biomolecular Engineering, KAIST, conducted this study as a part of his thesis research, and the study was featured as a journal cover paper in the February issue of Molecular BioSystems this year, published by The Royal Society of Chemistry based in Europe.
It was relatively easy to treat infectious microbes using antibiotics in the past. However, the overdose of antibiotics has caused pathogens to increase their resistance to various antibiotics, and it has become more difficult to cure infectious diseases these days.
A representative microbial pathogen is Acinetobacter baumannaii. Originally isolated from soils and water, this microorganism did not have resistance to antibiotics, and hence it was easy to eradicate them if infected. However, within a decade, this miroorganism has transformed into a dreadful super-bacterium resistant to antibiotics and caused many casualties among the U.S. and French soldiers who were injured from the recent Iraqi war and infected with Acinetobacter baumannaii.
Professor Lee’s group constructed an in silico cell of this A. baumannii by computationally collecting, integrating, and analyzing the biological information of the bacterium, scattered over various databases and literatures, in order to study this organism"s genomic features and system-wide metabolic characteristics. Furthermore, they employed this in silico cell for integrative approaches, including several network analysis and analysis of essential reactions and metabolites, to predict drug targets that effectively disrupt the pathogen"s growth. Final drug targets are the ones that selectively kill pathogens without harming human body.
Here, essential reactions refer to enzymatic reactions required for normal metabolic functioning in organisms, while essential metabolites indicate chemical compounds required in the metabolism for proper functioning, and their removal brings about the effect of simultaneously disrupting their associated enzymes that interact with them.
This study attempted to predict highly reliable drug targets by systematically scanning biological components, including metabolic genes, enzymatic reactions, that constitute an in silico cell in a short period of time.
This research achievement is highly regarded as it, for the first time, systematically scanned essential metabolites for the effective drug targets using the concept of systems biology, and paved the way for a new antibacterial discovery. This study is also expected to contribute to elucidating the infectious mechanism caused by pathogens.
"Although tons of genomic information is poured in at this moment, application research that efficiently converts this preliminary information into actually useful information is still lagged behind. In this regard, this study is meaningful in that medically useful information is generated from the genomic information of Acinetobacter baumannii," says Professor Lee. "In particular, development of this organism"s in silico cell allows generation of new knowledge regarding essential genes and enzymatic reactions under specific conditions," he added.
This study was supported by the Korean Systems Biology Project of the Ministry of Education, Science and Technology, and the patent for the development of in silico cells of microbial pathogens and drug targeting methods has been filed.
[Picture 1 Cells in silico]
[Picture 2 A process of generating drug targets without harming human body while effectively disrupting the growth of a pathogen, after predicting metabolites from in silico cells]
2010.04.05 View 14669
-
KAIST Research Team Identified Promising New Source to Obtain Stem Cells
KAIST Research Team Identified Promising New Source to Obtain Stem Cells
A research team at KAIST led by Professor Gou-Young Koh, M.D. and Ph.D., of the Department of Biological Sciences, has found evidence that fat tissue, known as adipose tissue, may be a promising new source of valuable and easy-to-obtain regenerative cells called hematopoietic stem and progenitor cells (HSPCs).
HSPCs are adult stem cells that have the ability to generate and develop into many different kinds of cells. They are now used to repair damaged tissues and are being studied for their potential to treat a vast array of chronic and degenerative conditions such as leukemia. Mostly found in bone marrow but with a limited quantity, HSPCs are hard to cultivate in vitro, thus becoming an obstacle to use them for research and therapeutic purposes.
Within the adipose tissue is a special cell population known as the stromal vascular fraction (SVF), which share similar properties to those in the bone marrow. Cells in the bone marrow and SVF have the ability to differentiate into several cell types. In addition, both adipose and bone marrow offer similar environments for optimal stem cell growth and reproduction.
Given the fact that adipose and bone marrow tissues share similar properties, Dr. Koh and his team conducted a research, injecting granulocyte colony-stimulating factor (G-CSF), a growth hormone used to encourage the development of stem cells, into an adipose tissue of a mouse whose bone marrow is damaged. As a result, the team has found that the SVF derived from adipose tissue contains functional HSPCs capable of generating hematopoietic (blood-forming) cells to repair the damaged bone morrow.
The Ministry of Education, Science and Technology nominated the KAIST research as one of its sponsoring 21st Century Frontier R&D Programs. Director Dong-Wook Kim of Stem Cell Research Center (SCRS) that oversees the KAIST team expressed a possibility to use the adipose tissue as an alternative source to obtain stem cells for regeneration medicine.
Dr. Koh also said, “It’s been a well known method to extract HSPCs from the bone morrow or blood, but it’s the first time to identify adipose tissue, before considered useless, as a new possible supplier for functional and transplantable HSPCs.”
The study results have received an important recognition from the academia—the American Society of Hematology published the research as a main article in its official journal, Blood, for the February 4th, 2010 issue, which is the most citied peer-reviewed publication in the field.
2010.02.05 View 11665
-
Prof. Lee"s Team Succeeds in Producing Plastics Without Use of Fossil Fuels
A team of scientists led by Prof. Sang-Yup Lee of the Department of Biological Sciences at KAIST have succeeded in producing the polymers used for everyday plastics through bioengineering, rather than through the use of fossil fuel based chemicals, the university authorities said on Tuesday (Nov. 24).
This groundbreaking research, which may now allow for the production of environmentally conscious plastics, has been published in two papers in the journal Biotechnology and Bioengineering.
Polymers are molecules found in everyday life in the form of plastics and rubbers. The team consisted of scientists from KAIST and Korean chemical company LG Chem focused their research on polylactic acid (PLA), a bio-based polymer which holds the key to producing plastics through natural and renewable resources.
"The polyesters and other polymers we use everyday are mostly derived from fossil oils made through the refinery or chemical process," said Lee. "The idea of producing polymers from renewable biomass has attracted much attention due to the increasing concerns of environmental problems and the limited nature of fossil resources. PLA is considered a good alternative to petroleum based plastics as it is both biodegradable and has a low toxicity to humans."
Until now PLA has been produced in a two-step fermentation and chemical process of polymerization, which is both complex and expensive. Now, through the use of a metabolically engineered strain of E.coli, the team has developed a one-stage process which produces polylactic acid and its copolymers through direct fermentation. This makes the renewable production of PLA and lactate-containing copolymers cheaper and more commercially viable.
"By developing a strategy which combines metabolic engineering and enzyme engineering, we"ve developed an efficient bio-based one-step production process for PLA and its copolymers," said Lee. "This means that a developed E. coli strain is now capable of efficiently producing unnatural polymers, through a one-step fermentation process,"
This combined approach of systems-level metabolic engineering and enzyme engineering now allows for the production of polymer and polyester based products through direct microbial fermentation of renewable resources.
"Global warming and other environmental problems are urging us to develop sustainable processes based on renewable resources," concluded Lee. "This new strategy should be generally useful for developing other engineered organisms capable of producing various unnatural polymers by direct fermentation from renewable resources".
2009.11.30 View 13912