RNA
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Metabolically engineered E. coli producing phenol
Many chemicals we use in everyday life are derived from fossil resources. Due to the increasing concerns on the use of fossil resources, there has been much interest in producing chemicals from renewable resources through biotechnology.
Phenol is an important commodity chemical, and is a starting material for the production of numerous industrial chemicals and polymers, including bisphenol A and phenolic resins, and others. At present, the production of phenol entirely depends on the chemical synthesis from benzene, and its annual production exceeds 8 million tons worldwide. Microbial production of phenol seems to be a non-viable process considering the high toxicity of phenol to the cell.
In the paper published online in Biotechnology Journal, a Korean research team led by Distinguished Professor Sang Yup Lee at the Department of Chemical and Biomolecular Engineering from the Korea Advanced Institute of Science and Technology (KAIST) reported the successful development of an engineered Escherichia coli (E. coli) strain which can produce phenol from glucose. E. coli has been a workhorse for biological production of various value-added compounds such as succinic acid and 1,4-butanediol in industrial scale. However, due to its low tolerance to phenol, E. coli was not considered a viable host strain for the biological production of phenol.
Professor Lee"s team, a leading research group in metabolic engineering, noted the genetic and physiological differences of various E. coli strains and investigated 18 different E. coli strains with respect to phenol tolerance and engineered all of the 18 strains simultaneously. If the traditional genetic engineering methods were used, this work would have taken years to do. To overcome this challenge, the research team used synthetic small RNA (sRNA) technology they recently developed (Nature Biotechnology, vol 31, pp 170-174, 2013). The sRNA technology allowed the team to screen 18 E. coli strains with respect to the phenol tolerance, and the activities of the metabolic pathway and enzyme involved in the production of phenol. The research team also metabolically engineered the E. coli strains to increase carbon flux toward phenol and finally generated an engineered E. coli strain which can produce phenol from glucose.
Furthermore, the team developed a biphasic extractive fermentation process to minimize the toxicity of phenol to E. coli cells. Glycerol tributyrate was found to have low toxicity to E. coli and allowed efficient extraction of phenol from the culture broth. Through the biphasic fed-batch fermentation using glycerol tributyrate as an in situ extractant, the final engineered E. coli strain produced phenol to the highest titer and productivity reported (3.8 g/L and 0.18 g/L/h, respectively). The strategy used for the strain development and the fermentation process will serve as a framework for metabolic engineering of microorganisms for the production of toxic chemicals from renewable resources.
This work was supported by the Intelligent Synthetic Biology Center through the Global Frontier Project (2011-0031963) of the Ministry of Science, ICT & Future Planning through the National Research Foundation of Korea.
Process of Phenol Production
2013.11.05 View 12159 -
A powerful strategy for developing microbial cell factories by employing synthetic small RNAs
The current systems for the production of chemicals, fuels and materials heavily rely on the use of fossil resources. Due to the increasing concerns on climate change and other environmental problems, however, there has been much interest in developing biorefineries for the production of such chemicals, fuels and materials from renewable resources. For the biorefineries to be competitive with the traditional fossil resource-based refineries, development of high performance microorganisms is the most important as it will affect the overall economics of the process most significantly. Metabolic engineering, which can be defined as purposeful modification of cellular metabolic and regulatory networks with an aim to improve the production of a desired product, has been successfully employed to improve the performance of the cell. However, it is not trivial to engineer the cellular metabolism and regulatory circuits in the cell due to their high complexity.
In metabolic engineering, it is important to find the genes that need to be amplified and attenuated in order to increase the product formation rate while minimizing the production of undesirable byproducts. Gene knock-out experiments are often performed to delete those metabolic fluxes that will consequently result in the increase of the desired product formation. However, gene knock-out experiments require much effort and time to perform, and are difficult to do for a large number of genes. Furthermore, the gene knock-out experiments performed in one strain cannot be transferred to another organism and thus the whole experimental process has to be repeated. This is a big problem in developing a high performance microbial cell factory because it is required to find the best platform strain among many different strains. Therefore, researchers have been eager to develop a strategy that allows rapid identification of multiple genes to be attenuated in multiple strains at the same time.
A Korean research team led by Distinguished Professor Sang Yup Lee at the Department of Chemical and Biomolecular Engineering from the Korea Advanced Institute of Science and Technology (KAIST) reported the development of a strategy for efficiently developing microbial cell factories by employing synthetic small RNAs (sRNAs). They first reported the development of such system in Nature Biotechnology last February. This strategy of employing synthetic sRNAs in metabolic engineering has been receiving great interest worldwide as it allows easy, rapid, high-throughput, tunable, and un-doable knock-down of multiple genes in multiple strains at the same time. The research team published a paper online on August 8 as a cover page (September issue) in Nature Protocols, describing the detailed strategy and protocol to employ synthetic sRNAs for metabolic engineering.
In this paper, researchers described the detailed step-by-step protocol for synthetic sRNA-based gene expression control, including the sRNA design principles. Tailor-made synthetic sRNAs can be easily manipulated by using conventional gene cloning method. The use of synthetic sRNAs for gene expression regulation provides several advantages such as portability, conditionality, and tunability in high-throughput experiments. Plasmid-based synthetic sRNA expression system does not leave any scar on the chromosome, and can be easily transferred to many other host strains to be examined. Thus, the construction of libraries and examination of different host strains are much easier than the conventional hard-coded gene manipulation systems. Also, the expression of genes can be conditionally repressed by controlling the production of synthetic sRNAs. Synthetic sRNAs possessing different repression efficiencies make it possible to finely tune the gene expression levels as well. Furthermore, synthetic sRNAs allow knock-down of the expression of essential genes, which was not possible by conventional gene knock-out experiments.
Synthetic sRNAs can be utilized for diverse experiments where gene expression regulation is needed. One of promising applications is high-throughput screening of the target genes to be manipulated and multiple strains simultaneously to enhance the production of chemicals and materials of interest. Such simultaneous optimization of gene targets and strains has been one of the big challenges in metabolic engineering. Another application is to fine tune the expression of the screened genes for flux optimization, which would enhance chemical production further by balancing the flux between biomass formation and target chemical production. Synthetic sRNAs can also be applied to finely regulating genetic interactions in a circuit or network, which is essential in synthetic biology. Once a sRNA scaffold-harboring plasmid is constructed, tailor-made, synthetic sRNAs can be made within 3-4 days, followed by the desired application experiments.
Dr. Eytan Zlotorynski, an editor at Nature Protocols, said "This paper describes the detailed protocol for the design and applications of synthetic sRNA. The method, which has many advantages, is likely to become common practice, and prove useful for metabolic engineering and synthetic biology studies."
This paper published in Nature Protocols will be useful for all researchers in academia and industry who are interested in the use of synthetic sRNAs for fundamental and applied biological and biotechnological studies.
This work was supported by the Technology Development Program to Solve Climate Changes on Systems Metabolic Engineering for Biorefineries (NRF-2012-C1AAA001-2012M1A2A2026556) and the Intelligent Synthetic Biology Center through the Global Frontier Project (2011-0031963) of the Ministry of Science, ICT and Future Planning through the National Research Foundation of Korea.
2013.10.31 View 11685 -
First Prize in the 2013 International Military Science and Technology Contest
Professor James R. Morrison and his students of the Industrial and Systems Engineering Department at KAIST were awarded the first prize in the 2013 International Military Science and Technology Contest organized by the Defense Acquisition Program Administration held in COEX from July 11 to 14.
The research group, Byungduk Song (Ph.D candidate), Jonghoe Kim (Ph.D candidate), Hyolin Park (MS candidate) and Professor James R. Morrison, received the first prize with their paper entitled “Automated and persistent UAV system for a complementary method for border patrol and target tracking.”
The Defense Acquisition Program Administration is the host of the annual contest which aims to contribute to the future of the defense industry and to expand technology exchange between private institutes and the military through the coordination of defense technology and advanced technology from industrial and educational cooperation.Professor Morrison’s team received the honor of the first-place prize out of 56 competitors from within Korea and 7 from overseas in the field of Synthetic New Technology/Academic Thesis.
2013.10.31 View 11151 -
2013 International Conference for the Integration of Science, Technology, and Society at KAIST (ICISTS-KAIST)
The International Conference for the Integration of Science, Technology, and Society at KAIST (ICISTS-KAIST) is a global forum organized by KAIST undergraduate students to promote the exchange of ideas and facilitate the discussion of issues that are important to science, technology, society, and higher education. The ICISTS-KAIST conference has been held annually every summer since 2005, inviting distinguished speakers and guests from all around the world to share their insights and expertise with students gathered from Korea and abroad. Last year alone, more than 300 students from 22 nations and 40 speakers participated in the event.
Originally, the ICISTS-KAIST was established by KAIST students who were inspired by the Harvard Project for Asian and International Relations (HPAIR), which is one of the Harvard’s largest annual student conferences in Asia.
This year, 335 students from 103 universities in 22 countries joined the conference that was held on August 5th-9th in Daejeon, making the 2013 ICISTS-KAIST the biggest science and engineering gathering hosted by university students in Asia. About 36% of the participants were international students.
The theme of the conference was “Perfect Alliance: Coexistence for Human Society,” in which students and speakers addressed issues on how to harmonize the speed of scientific progress with the development of important values in society, as well as to explore solutions to overcome the chasm, if any, between the boundaries of science and society.
In his opening remarks, President Steve Kang said, “Creativity and innovation are born out of openness. Therefore, it is essential for young scientists and engineers to communicate with people from different cultural and political backgrounds. Through this kind of global interaction and exchange of ideas and views, students will have an opportunity to deepen their understanding of the world and to better examine the purpose of their intellectual exploration in science and technology.” At the 2013 ICISTS-KAIST, 25 distinguished speakers participated including Walter Bender, a former director of the Media Lab at MIT and David Christian, a professor of Macquarie University in Australia.
2013.08.08 View 12795 -
A magnetic pen for smartphones adds another level of conveniences
Utilizing existing features on smartphones, the MagPen provides users with a compatible and simple input tool regardless of the type of phones they are using.
A doctoral candidate at the Korea Advanced Institute of Science and Technology (KAIST) developed a magnetically driven pen interface that works both on and around mobile devices. This interface, called the MagPen, can be used for any type of smartphones and tablet computers so long as they have magnetometers embedded in.
Advised by Professor Kwang-yun Wohn of the Graduate School of Culture Technology (GSCT) at KAIST, Sungjae Hwang, a Ph.D. student, created the MagPen in collaboration with Myung-Wook Ahn, a master"s student at the GSCT of KAIST, and Andrea Bianchi, a professor at Sungkyunkwan University.
Almost all mobile devices today provide location-based services, and magnetometers are incorporated in the integrated circuits of smartphones or tablet PCs, functioning as compasses. Taking advantage of built-in magnetometers, Hwang"s team came up with a technology that enabled an input tool for mobile devices such as a capacitive stylus pen to interact more sensitively and effectively with the devices" touch screen. Text and command entered by a stylus pen are expressed better on the screen of mobile devices than those done by human fingers.
The MagPen utilizes magnetometers equipped with smartphones, thus there is no need to build an additional sensing panel for a touchscreen as well as circuits, communication modules, or batteries for the pen. With an application installed on smartphones, it senses and analyzes the magnetic field produced by a permanent magnet embedded in a standard capacitive stylus pen.
Sungjae Hwang said, "Our technology is eco-friendly and very affordable because we are able to improve the expressiveness of the stylus pen without requiring additional hardware beyond those already installed on the current mobile devices. The technology allows smartphone users to enjoy added convenience while no wastes generated."
The MagPen detects the direction at which a stylus pen is pointing; selects colors by dragging the pen across smartphone bezel; identifies pens with different magnetic properties; recognizes pen-spinning gestures; and estimates the finger pressure applied to the pen.
Notably, with its spinning motion, the MagPen expands the scope of input gestures recognized by a stylus pen beyond its existing vocabularies of gestures and techniques such as titling, hovering, and varying pressures. The tip of the pen switches from a pointer to an eraser and vice versa when spinning. Or, it can choose the thickness of the lines drawn on a screen by spinning.
"It"s quite remarkable to see that the MagPen can understand spinning motion. It"s like the pen changes its living environment from two dimensions to three dimensions. This is the most creative characteristic of our technology," added Sungjae Hwang.
Hwang"s initial research result was first presented at the International Conference on Intelligent User Interfaces organized by the Association for Computing Machinery and held on March 19-22 in Santa Monica, the US.
In the next month of August, the research team will present a paper on the MagPen technology, entitled "MagPen: Magnetically Driven Pen Interaction On and Around Conventional Smartphones" and receive an Honorable Mention Award at the 15th International Conference on Human-Computer Interaction with Mobile Devices and Services (MobileHCI 2013) to be held in Germany.
In addition to the MagPen, Hwang and his team are conducting other projects to develop different types of magnetic gadgets (collectively called "MagGetz") that include the Magnetic Marionette, a magnetic cover for a smartphone, which offers augmented interactions with the phone, as well as magnetic widgets such as buttons and toggle interface.
Hwang has filed ten patents for the MagGetz technology.
Youtube Links: http://www.youtube.com/watch?v=NkPo2las7wc, http://www.youtube.com/watch?v=J9GtgyzoZmM
2013.07.25 View 13860 -
Prof. Song Chong received the IEEE William R. Bennett Prize Paper Award
The IEEE (Institute of Electrical and Electronics Engineers) Communications Society (ComSoc), a renowned global network of professionals with a common interest in advancing communications technologies, has announced the winner of the 2013 William R. Bennett Prize in the field of communications networking. The prize was given to a Korean research team led by Song Chong, Professor of Electrical Engineering at KAIST and Injong Rhee, Professor of Computer Science at North Carolina State University. In addition, Dr. Minsu Shin, Dr. Seongik Hong, and Dr. Seong Joon Kim of Samsung Electronics Co., Ltd. as well as Professor Kyunghan Lee from Ulsan National Institute of Science and Technology were recognized for their contribution.
The William R. Bennett Prize for communications networking has been awarded each year since 1994 in recognition of the best paper published in any journal financially sponsored or co-sponsored by ComSoc in the previous three calendar years. Only one paper per year is selected based on its quality, originality, scientific citation index, and peer reviews. Among the previous award winners are Robert Gallager of MIT, and Steven Low of the California Institute of Technology, and Kang G. Shin of the University of Michigan.
The Korean research team’s paper, On the Levy-Walk Nature of Human Mobility, was published in the June 2011 issue of IEEE/ACM Transactions on Networking, a bimonthly journal co-sponsored by the IEEE ComSoc, the IEEE Computer Society, and the Association for Computing Machinery (ACM) with its Special Interest Group on Data Communications (SIGCOMM).
In the paper, the research team proposed a new statistical model to effectively analyze the pattern of individual human mobility in daily life. The team handed out GPS (global positioning system) devices to 100 participants residing in five different university campuses in Korea and the US and collected data on their movements for 226 days. The mobility pattern obtained from the experiment predicted accurately how the participants actually moved around during their routines. Since publication, the paper has been cited by other papers approximately 350 times.
The team’s research results will apply to many fields such as the prevention and control of epidemics, the design of efficient communications networks, and the development of urban and transportation system.
The research team received the award on June 10th at the 2013 IEEE International Conference on Communications (ICC) held in Budapest, Hungary, from June 9-13, 2013.
Professor Song Chong
2013.07.06 View 17031 -
Foreign graduates donate to development fund for six years
International graduates of the Global IT Technology Graduate School at KAIST have continued a tradition of giving something back to their alma mater.
On May 10th, President Steve Kang held a donation ceremony with 12 donors.
Started in 2008, the graduates, mostly consisted of government officials from developing countries, have raised a development fund for KAIST, and in the past six years, a total of 81 graduates donated USD 10,000.
“KAIST provided me with an excellent education and research environment during my studies. I’m glad that I can have an opportunity to help my juniors and the university,” said Naryn Kenzhaliyev of Kazakhstan, a graduate present at the ceremony.
“Every year, these students voluntarily give when they are about to graduate. We feel proud and greatly appreciated for their philanthropic efforts,” said Professor Jae-Jung Noh, responsible for the global IT technology graduate program.
Established in 2006, the Global IT Technology Graduate School has attracted IT specialists from Korea and abroad, offering master’s and doctoral degrees. The school has invited many public servants in developing countries whose expertise lies in IT technology.
2013.07.04 View 7488 -
International Student Conference (ICISTS-KAIST) to be Held in August
- 300 participants including university students worldwide and renowned speakers expected to gather
- Ideal coexistence of science & technology and society explored under the theme of “Perfect Alliance”
Science & technology and society are at the core of 21st century’s development. ICISTS-KAIST 2013, international conference for university students, seeks ways for the two to coexist harmoniously and is to be held from August 5 to 9 on KAIST campus as well as at Daejeon Convention Center.
ICISTS stands for International Conference for the Integration of Science, Technology and Society. ICISTS-KAIST is a non-profit organization run by KAIST students who are directly engaged in the coordination, planning, finance, public relations, and management of this academic event. The upcoming ninth annual event of ICISTS (www.icists.org) 2013 is centered around the theme, “Perfect Alliance: Coexistence for Human Society.” The conference will last for four nights and five days; scholars and students across various academic backgrounds gather to narrow the gap between fields of study and discuss possible solutions to the problems in today’s society.
The annual conference, ICISTS-KAIST attracts hundreds of participants from all over the world to KAIST, Daejeon and its most recent event last year witnessed discussions among some 300 students from 22 countries hearing the lectures from 40 academics and scholars. This year’s event will welcome the 16-year old inventor, scientist, and cancer researcher Jack Thomas Andraka, the founder of the “One Laptop Per Child” project Walter Bender, Chemistry Nobel Prize laureate Harold Walter Kroto, and many more.
The application period for ICISTS-KAIST 2013 runs from May 20 to July 12, and applications are received through the website at www.icists.org.
ICISTS-KAIST 2013 Promgram Summary
Event Title: International Conference for the Integration of Science, Technology and Society 2013 (ICISTS-KAIST 2013)
Theme: Perfect Alliance: Coexistence for Human Society
Date and Venue: 2013 Aug. 5 (Mon.) ~ Aug. 9 (Fri.), KAIST Campus and Daejeon Convention Center
Host and Organizer: ICISTS KAIST
Sponsor: Korean National Commission for UNESCO, Korea Tourism Organization, Korea Ministry of Education, Science & Technology, KOFST
Session Description:
Keynote Speech - Keynote address on fundamental approach to coexistence
Parallel Session - Multiple simultaneous lecture of delegates’ choice
Group Discussion - Small group discussions among delegates and speakers
Panel Discussion - In-depth and thought-revealing discussion among speakers
Experience Session - First-person experience on relevant technology
Team Project & Poster Fair - Team mission, poster exhibition and evaluation
Subtopics:
- New Values from Coexistence of Science & Technology and Society
- Synergetic Resolution via Coexistence of Science & Technology and Society
- Essential Communication for Coexistence of Science & Technology and Society
Notable Speakers:
- Gretchen Kalonji: Assistant to Director-General at UNESCO
- Sheila Jasanoff: Director of STS Program at Harvard Kennedy School
- Walter Bender: Former Director of MIT Media Lab and One Laptop Per Child- Jack Andraka: 16-year old Cancer Resesarcher
2013.05.31 View 10870 -
An efficient strategy for developing microbial cell factories by employing synthetic small regulatory RNAs
A new metabolic engineering tool that allows fine control of gene expression level by employing synthetic small regulatory RNAs was developed to efficiently construct microbial cell factories producing desired chemicals and materials
Biotechnologists have been working hard to address the climate change and limited fossil resource issues through the development of sustainable processes for the production of chemicals, fuels and materials from renewable non-food biomass. One promising sustainable technology is the use of microbial cell factories for the efficient production of desired chemicals and materials. When microorganisms are isolated from nature, the performance in producing our desired product is rather poor. That is why metabolic engineering is performed to improve the metabolic and cellular characteristics to achieve enhanced production of desired product at high yield and productivity. Since the performance of microbial cell factory is very important in lowering the overall production cost of the bioprocess, many different strategies and tools have been developed for the metabolic engineering of microorganisms.
One of the big challenges in metabolic engineering is to find the best platform organism and to find those genes to be engineered so as to maximize the production efficiency of the desired chemical. Even Escherichia coli, the most widely utilized simple microorganism, has thousands of genes, the expression of which is highly regulated and interconnected to finely control cellular and metabolic activities. Thus, the complexity of cellular genetic interactions is beyond our intuition and thus it is very difficult to find effective target genes to engineer. Together with gene amplification strategy, gene knockout strategy has been an essential tool in metabolic engineering to redirect the pathway fluxes toward our desired product formation. However, experiment to engineer many genes can be rather difficult due to the time and effort required; for example, gene deletion experiment can take a few weeks depending on the microorganisms. Furthermore, as certain genes are essential or play important roles for the survival of a microorganism, gene knockout experiments cannot be performed. Even worse, there are many different microbial strains one can employ. There are more than 50 different E. coli strains that metabolic engineer can consider to use. Since gene knockout experiment is hard-coded (that is, one should repeat the gene knockout experiments for each strain), the result cannot be easily transferred from one strain to another.
A paper published in Nature Biotechnology online today addresses this issue and suggests a new strategy for identifying gene targets to be knocked out or knocked down through the use of synthetic small RNA. A Korean research team led by Distinguished Professor Sang Yup Lee at the Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), a prestigeous science and engineering university in Korea reported that synthetic small RNA can be employed for finely controlling the expression levels of multiple genes at the translation level. Already well-known for their systems metabolic engineering strategies, Professor Lee’s team added one more strategy to efficiently develop microbial cell factories for the production of chemicals and materials.
Gene expression works like this: the hard-coded blueprint (DNA) is transcribed into messenger RNA (mRNA), and the coding information in mRNA is read to produce protein by ribosomes. Conventional genetic engineering approaches have often targeted modification of the blueprint itself (DNA) to alter organism’s physiological characteristics. Again, engineering the blueprint itself takes much time and effort, and in addition, the results obtained cannot be transferred to another organism without repeating the whole set of experiments. This is why Professor Lee and his colleagues aimed at controlling the gene expression level at the translation stage through the use of synthetic small RNA. They created novel RNAs that can regulate the translation of multiple messenger RNAs (mRNA), and consequently varying the expression levels of multiple genes at the same time. Briefly, synthetic regulatory RNAs interrupt gene expression process from DNA to protein by destroying the messenger RNAs to different yet controllable extents. The advantages of taking this strategy of employing synthetic small regulatory RNAs include simple, easy and high-throughput identification of gene knockout or knockdown targets, fine control of gene expression levels, transferability to many different host strains, and possibility of identifying those gene targets that are essential.
As proof-of-concept demonstration of the usefulness of this strategy, Professor Lee and his colleagues applied it to develop engineered E. coli strains capable of producing an aromatic amino acid tyrosine, which is used for stress symptom relief, food supplements, and precursor for many drugs. They examined a large number of genes in multiple E. coli strains, and developed a highly efficient tyrosine producer. Also, they were able to show that this strategy can be employed to an already metabolically engineered E. coli strain for further improvement by demonstrating the development of highly efficient producer of cadaverine, an important platform chemical for nylon in the chemical industry.
This new strategy, being simple yet very powerful for systems metabolic engineering, is thus expected to facilitate the efficient development of microbial cell factories capable of producing chemicals, fuels and materials from renewable biomass.
Source: Dokyun Na, Seung Min Yoo, Hannah Chung, Hyegwon Park, Jin Hwan Park, and Sang Yup Lee, “Metabolic engineering of Escherichia coli using synthetic small regulatory RNAs”, Nature Biotechnology, doi:10.1038/nbt.2461 (2013)
2013.03.19 View 12053
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New BioFactory Technique Developed using sRNAs
Professor Sang Yup Lee
- published on the online edition of Nature Biotechnology. “Expected as a new strategy for the bio industry that may replace the chemical industry.”-
KAIST Chemical & Biomolecular engineering department’s Professor Sang Yup Lee and his team has developed a new technology that utilizes the synthetic small regulatory RNAs (sRNAs) to implement the BioFactory in a larger scale with more effectiveness.
* BioFactory: Microbial-based production system which creates the desired compound in mass by manipulating the genes of the cell.
In order to solve the problems of modern society, such as environmental pollution caused by the exhaustion of fossil fuels and usage of petrochemical products, an eco-friendly and sustainable bio industry is on the rise. BioFactory development technology has especially attracted the attention world-wide, with its ability to produce bio-energy, pharmaceuticals, eco-friendly materials and more.
For the development of an excellent BioFactory, selection for the gene that produces the desired compounds must be accompanied by finding the microorganism with high production efficiency; however, the previous research method had a complicated and time-consuming problem of having to manipulate the genes of the microorganism one by one.
Professor Sang Yup Lee’s research team, including Dr. Dokyun Na and Dr. Seung Min Yoo, has produced the synthetic sRNAs and utilized it to overcome the technical limitations mentioned above.
In particular, unlike the existing method, this technology using synthetic sRNAs exhibits no strain specificity which can dramatically shorten the experiment that used to take months to just a few days.
The research team applied the synthetic small regulatory RNA technology to the production of the tyrosine*, which is used as the precursor of the medicinal compound, and cadaverine**, widely utilized in a variety of petrochemical products, and has succeeded developing BioFactory with the world’s highest yield rate (21.9g /L, 12.6g / L each).
*tyrosine: amino acid known to control stress and improve concentration
**cadaverine: base material used in many petrochemical products, such as polyurethane
Professor Sang Yup Lee highlighted the significance of this research: “it is expected the synthetic small regulatory RNA technology will stimulate the BioFactory development and also serve as a catalyst which can make the chemical industry, currently represented by its petroleum energy, transform into bio industry.”
The study was carried out with the support of Global Frontier Project (Intelligent Bio-Systems Design and Synthesis Research Unit (Chief Seon Chang Kim)) and the findings have been published on January 20th in the online edition of the worldwide journal Nature Biotechnology.
2013.02.21 View 14110
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Op-Ed by Prof. David Helfman: Global Science and Education in the 21st Century
Professor David Helfman from the Department of Biological Sciences and Graduate School of Nanoscience and Technology(https://sites.google.com/site/cellsignalinglaboratory/home) recently wrote an Op-Ed in the January 2013 issue of Journal of Happy Scientists and Engineers that ispublished by the Ministry of Science, Education and Technology, the Republic of Korea. In the article entitled “Global Science and Education in the 21st Century,” Professor Helfman addressed three important issues in science and education, which will have a great impact for the development of world-leading universities in Korea. For the article, please see the attachment.
2013.01.22 View 14787
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High Efficiency Bio-butanol production technology developed
KAIST and Korean Company cooperative research team has developed the technology that increases the productivity of bio-butanol to equal that of bio-ethanol and decreases the cost of production.
Professor Lee Sang Yeop (Department of Biological-Chemical Engineering) collaborated with GS Caltex and BioFuelChem Ltd. to develop a bio-butanol production process using the system metabolism engineering method that increased the productivity and decreased the production cost.
Bio-butanol is being widely regarded as the environmentally friendly next generation energy source that surpasses bio-ethanol.
The energy density of bio-butanol is 29.9MJ (mega Joule) per Liter, 48% larger than bio-ethanol (19.6MJ) and comparable to gasoline (32MJ). Bio-butanol is advantageous in that it can be processed from inedible biomass and is therefore unrelated to food crises.
Especially because bio-butanol shows similar characteristics especially in its octane rating, enthalpy of vaporization, and air-fuel ratio, it can be used in a gasoline engine.
However barriers such as difficulty in gene manipulation of producer bacterium and insufficient information prevented the mass production of bio-butanol.
Professor Lee’s team applied the system metabolism engineering method that he had invented to shift the focus to the production pathway of bio-butanol and made a new metabolism model.
In the new model the bio-butanol production pathway is divided into the hot channel and the cold channel.
The research team focused on improving the efficiency of the hot channel and succeeded in improving the product yield of 49% (compared to theoretical yield) to 87%.
The team furthered their research and developed a live bio-butanol collection and removal system with GS Caltex. The collaboration succeeded in producing 585g of butanol using 1.8kg of glucose at a rate of 1.3g per hour, boasting world’s highest concentration, productivity, and rate and improving productivity of fermentation by three fold and decreasing costs by 30%.
The result of the research was published in world renowned ‘mBio’ microbiology journal.
2012.12.21 View 10617