biomass
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KAIST Develops Microbial Liquid Egg Substitute
A team of researchers published a paper on developing a substitute for eggs using microorganisms, grabbing international attention. It is expected that the development of egg substitutes using non-animal raw materials will solve the problems of factory farming, which causes problems like increased emission of greenhouse gas and waste, and contribute to building a sustainable food system that allows easy protein intake.
KAIST (President Kwang-Hyung Lee) announced that Research Professor Kyeong Rok Choi from the Biological Process Research Center and Distinguished Professor Sang Yup Lee from the Department of Chemical and Biomolecular Engineering have published a paper on the development of an "Eco-Friendly Liquid Egg Substitute Derived from Microorganisms."
Eggs play a crucial role in various culinary applications due to their unique physicochemical properties such as gelling, foaming, and emulsifying, while also providing essential nutrients. However, traditional egg production is not only unethical and resource-intensive but also has significant environmental impacts such as greenhouse gas emissions and waste issues. Additionally, factors such as wars and trade regulations have led to significant increases in egg prices, highlighting food security concerns. In response to these issues, there has been growing interest in egg substitutes made from non-animal sources to establish a sustainable food system.
Although there has been progress in developing non-animal protein-based egg substitutes, no substitute has been able to fully replicate the essential functional properties of liquid eggs, such as gelling and foaming, while also providing complete nutrition. In this context, the research team aimed to develop a liquid egg substitute using microbial biomass, which has a protein content comparable to that of meat per unit dry mass. Various microorganisms, such as yeast, Bacillus, lactic acid bacteria, and other probiotics, have been proven safe through long-term human consumption. Microbial biomass requires fewer resources like water and land during production, and possesses high-quality nutrients, making it a promising sustainable food resource.
< Figure 1. Comparison of heat treatment results of microbial pellets and microbial lysates >
However, the semi-solid microbial biomass recovered through microbial cultivation was observed to turn liquid upon heating, unlike liquid egg. To address this, the research team devised a microbial lysate by breaking down the cell walls and cell membranes of microorganisms, which correspond to the eggshell. They found that the microbial lysate's proteins coagulated when heated and formed a gel similar to that of liquid egg. The gel formed from the heated microbial lysate was found to have microscopic structures and physical properties similar to those of boiled eggs. The addition of microbial-derived edible enzymes or plant-based materials allowed for the adjustment of its properties, enabling the creation of various textures.
Furthermore, the researchers demonstrated that the microbial lysate could form stable foams widely used in baking, such as meringues (made from egg whites). They successfully baked meringue cookies using this lysate, showing its potential as a functional liquid egg substitute.
Distinguished Professor Sang Yup Lee stated, "This substitute has excellent nutritional components, making it suitable for regular food consumption. It is especially promising as emergency food for long-term space travel, wartime situations, and other emergencies. More importantly, it contributes to securing a sustainable food system."
< Figure 2. Example of foaming ability of microbial lysate and meringue cookie production >
< Figure 3. Example of foaming ability of microbial lysate and meringue cookie production >
The paper was published online in the journal npj Science of Food, issued by Nature.
- Paper Title: Microbial lysates repurposed as liquid egg substitutes
- Authors: Kyeong Rok Choi (first author), Da-Hee Ahn, Seok Yeong Jung, YuHyun Lee, and Sang Yup Lee (corresponding author)
This research was supported by the Ministry of Science and ICT's project for developing eco-friendly chemical technologies to replace petroleum (Project Leader: Distinguished Professor Sang Yup Lee, KAIST) and the Rural Development Administration's Agricultural Microorganisms Project Group (Director: Professor Pan-sik Jang, Seoul National University) for developing protein production technology from inorganic substances through microbial metabolic system control (Project Leader: Research Professor Kyeong Rok Choi, KAIST).
2024.07.05 View 3310 -
KAIST introduces microbial food as a strategy food production of the future
The global food crisis is increasing due to rapid population growth and declining food productivity to climate change. Moreover, today's food production and supply system emit a huge amount of carbon dioxide, reaching 30% of the total amount emitted by humanity, aggravating climate change. Sustainable and nutritious microbial food is attracting attention as a key to overcoming this impasse.
KAIST (President Kwang Hyung Lee) announced on April 12th that Research Professor Kyeong Rok Choi of the BioProcess Engineering Research Center and Distinguished Professor Sang Yup Lee from the Department of Chemical and Biomolecular Engineering published a paper that proposes a direction of research on ‘microbial food production from sustainable raw materials.’
Microbial food refers to various foods and food ingredients produced using microorganisms. Microbial biomass contains a large amount of protein per unit in dry mass, comparable to that of meat, and emits the smallest amount of carbon dioxide and is required to produce a unit mass compared to various livestock, fish, shellfish, and crops. Since the amount of water and space requirement is small, it can be an eco-friendly, sustainable and highly nutritious food resource.
Fermented foods are the most readily available microbial foods around us. Although the proportion of microbial biomass in fermented foods is small, compounds with relatively low nutritional value, such as carbohydrates, are consumed during the fermentation process, and as microorganisms proliferate, the content of nutrients with higher nutritional value, such as proteins and vitamins, increases.
Various food compounds isolated and purified from biomass or culture media obtained through microbial culture are also a branch of microbial food. Examples that can be found around us include various amino acids, including monosodium glutamate, food proteins, enzymes, flavoring compounds, food colorings, and bioactive substances.
< Figure 1. Schematic diagram portraying various microbial biomass production strategies utlizing sustainable feedstocks >
Lastly, the most ultimate and fundamental form of microbial food can be said to be microbial biomass or extracts produced through microbial culture and foods cooked using them. A representative example is single-cell protein, which collectively refers to microbial biomass or microbial proteins extracted from it.
In this paper, the researchers comprehensively covered various non-edible raw materials and strategies for using them that can be used to produce microbial food in a more sustainable way. Furthermore, it covers various microbial foods that are actually produced in the industry using the relevant raw materials and their characteristics, as well as prospects for the production and generalization of sustainable microbial foods.
Research Professor Kyeong Rok Choi, the first author of this paper, said, “Microbial foods produced from various sustainable raw materials will soon be commonly encountered at our tables.” Second author Seok Yeong Jung, a doctoral student, also said, “Microbial foods of the future will not be limited foods consumed only out of a sense of obligation to the environment, but will be complete foods that are consumed by choice because of their nutritional value and taste.” In addition, Distinguished Professor Sang Yup Lee said, “It is time for the industry and academia, as well as the public and private sectors, to cooperate more closely so that more diverse microbial foods can be developed and supplied in order to create a sustainable society for ourselves and our descendants.”
< Figure 2. Compositions and environmental footprints of animal, plant and microbial biomass. >
This paper was published online on April 9 in ‘Nature Microbiology’ published by Nature.
※ Paper title: From sustainable feedstocks to microbial foods
※ Author information: Kyeong Rok Choi (first author), Seok Yeong Jung (second author) and Sang Yup Lee (corresponding author)
This research was conducted under the development of platform technologies of microbial cell factories for the next-generation biorefineries project (project leader KAIST Distinguished Professor Sang Yup Lee) supported by the Ministry of Science and ICT and the Cooperative Research Program for Agriculture Science and Technology Development (Project leader KAIST Research Professor Kyeong Rok Choi) of the Agricultural Microbiology Project Group (Director, Professor Pahn-Shick Chang) supported by the Rural Development Administration.
2024.04.12 View 3817 -
Expanding the Biosynthetic Pathway via Retrobiosynthesis
- Researchers reports a new strategy for the microbial production of multiple short-chain primary amines via retrobiosynthesis. -
KAIST metabolic engineers presented the bio-based production of multiple short-chain primary amines that have a wide range of applications in chemical industries for the first time. The research team led by Distinguished Professor Sang Yup Lee from the Department of Chemical and Biomolecular Engineering designed the novel biosynthetic pathways for short-chain primary amines by combining retrobiosynthesis and a precursor selection step.
The research team verified the newly designed pathways by confirming the in vivo production of 10 short-chain primary amines by supplying the precursors. Furthermore, the platform Escherichia coli strains were metabolically engineered to produce three proof-of-concept short-chain primary amines from glucose, demonstrating the possibility of the bio-based production of diverse short-chain primary amines from renewable resources. The research team said this study expands the strategy of systematically designing biosynthetic pathways for the production of a group of related chemicals as demonstrated by multiple short-chain primary amines as examples.
Currently, most of the industrial chemicals used in our daily lives are produced with petroleum-based products. However, there are several serious issues with the petroleum industry such as the depletion of fossil fuel reserves and environmental problems including global warming. To solve these problems, the sustainable production of industrial chemicals and materials is being explored with microorganisms as cell factories and renewable non-food biomass as raw materials for alternative to petroleum-based products. The engineering of these microorganisms has increasingly become more efficient and effective with the help of systems metabolic engineering – a practice of engineering the metabolism of a living organism toward the production of a desired metabolite. In this regard, the number of chemicals produced using biomass as a raw material has substantially increased.
Although the scope of chemicals that are producible using microorganisms continues to expand through advances in systems metabolic engineering, the biological production of short-chain primary amines has not yet been reported despite their industrial importance. Short-chain primary amines are the chemicals that have an alkyl or aryl group in the place of a hydrogen atom in ammonia with carbon chain lengths ranging from C1 to C7. Short-chain primary amines have a wide range of applications in chemical industries, for example, as a precursor for pharmaceuticals (e.g., antidiabetic and antihypertensive drugs), agrochemicals (e.g., herbicides, fungicides and insecticides), solvents, and vulcanization accelerators for rubber and plasticizers. The market size of short-chain primary amines was estimated to be more than 4 billion US dollars in 2014.
The main reason why the bio-based production of short-chain primary amines was not yet possible was due to their unknown biosynthetic pathways. Therefore, the team designed synthetic biosynthetic pathways for short-chain primary amines by combining retrobiosynthesis and a precursor selection step. The retrobiosynthesis allowed the systematic design of a biosynthetic pathway for short-chain primary amines by using a set of biochemical reaction rules that describe chemical transformation patterns between a substrate and product molecules at an atomic level.
These multiple precursors predicted for the possible biosynthesis of each short-chain primary amine were sequentially narrowed down by using the precursor selection step for efficient metabolic engineering experiments.
“Our research demonstrates the possibility of the renewable production of short-chain primary amines for the first time. We are planning to increase production efficiencies of short-chain primary amines. We believe that our study will play an important role in the development of sustainable and eco-friendly bio-based industries and the reorganization of the chemical industry, which is mandatory for solving the environmental problems threating the survival of mankind,” said Professor Lee.
This paper titled “Microbial production of multiple short-chain primary amines via retrobiosynthesis” was published in Nature Communications. This work was supported by the Technology Development Program to Solve Climate Changes on Systems Metabolic Engineering for Biorefineries from the Ministry of Science and ICT through the National Research Foundation (NRF) of Korea.
-Publication
Dong In Kim, Tong Un Chae, Hyun Uk Kim, Woo Dae Jang, and Sang Yup Lee. Microbial production of multiple short-chain primary amines via retrobiosynthesis. Nature Communications ( https://www.nature.com/articles/s41467-020-20423-6)
-Profile
Distinguished Professor Sang Yup Lee
leesy@kaist.ac.kr
Metabolic &Biomolecular Engineering National Research Laboratory
http://mbel.kaist.ac.kr
Department of Chemical and Biomolecular Engineering
KAIST
2021.01.14 View 10241 -
Distinguished Professor Sang Yup Lee Announced as the Eni Award Recipient
(Distinguished Professor Sang Yup Lee)
Distinguished Professor Sang Yup Lee from the Department of Chemical and Biomolecular Engineering will be awarded the 2018 Eni Advanced Environmental Solutions Prize in recognition of his innovations in the fields of energy and environment. The award ceremony will take place at the Quirinal Palace, the official residence of Italian President Sergio Mattarella, who will also be attending on October 22.
Eni, an Italian multinational energy corporation established the Eni Award in 2008 to promote technological and research innovation of efficient and sustainable energy resources. The Advanced Environmental Solutions Prize is one of the three categories of the Eni Award. The other two categories are Energy Transition and Energy Frontiers. The Award for Advanced Environmental Solutions recognizes a researcher or group of scientists that has achieved internationally significant R&D results in the field of environmental protection and recovery. The Eni Award is referred to as the Nobel Award in the fields of energy and environment.
Professor Lee, a pioneering leader in systems metabolic engineering was honored with the award for his developing engineered bacteria to produce chemical products, fuels, and non-food biomass materials sustainably and with a low environmental impact. He has leveraged the technology to develop microbial bioprocesses for the sustainable and environmentally friendly production of chemicals, fuels, and materials from non-food renewable biomass.
The award committee said that they considered the following elements in assessing Professor Lee’s achievement: the scientific relevance and the research innovation level; the impact on the energy system in terms of sustainability as well as fairer and broader access to energy; and the adequacy between technological and economic aspects.
Professor Lee, who already won two other distinguished prizes such as the George Washington Carver Award and the PV Danckwerts Memorial Lecture Award this year, said, “I am so glad that the international academic community as well as global industry leaders came to recognize our work that our students and research team has made for decades.”
Dr. Lee’s lab has been producing a lot of chemicals in environmentally friendly ways. Among them, many were biologically produced for the first time and some of these processes have been already commercialized. “We will continue to strive for research outcomes with two objectives: First, to develop bio-based processes suitable for sustainable chemical industry. The other is to contribute to the human healthcare system through development of platform technologies integrating medicine and nutrition,” he added.
2018.09.12 View 6231 -
KAIST announced a novel technology to produce gasoline by a metabolically engineered microorganism
A major scientific breakthrough in the development of renewable energy sources and other important chemicals; The research team succeeded in producing 580 mg of gasoline per liter of cultured broth by converting in vivo generated fatty acids
For many decades, we have been relying on fossil resources to produce liquid fuels such as gasoline, diesel, and many industrial and consumer chemicals for daily use. However, increasing strains on natural resources as well as environmental issues including global warming have triggered a strong interest in developing sustainable ways to obtain fuels and chemicals.
Gasoline, the petroleum-derived product that is most widely used as a fuel for transportation, is a mixture of hydrocarbons, additives, and blending agents. The hydrocarbons, called alkanes, consist only of carbon and hydrogen atoms. Gasoline has a combination of straight-chain and branched-chain alkanes (hydrocarbons) consisted of 4-12 carbon atoms linked by direct carbon-carbon bonds.
Previously, through metabolic engineering of Escherichia coli (E. coli), there have been a few research results on the production of long-chain alkanes, which consist of 13-17 carbon atoms, suitable for replacing diesel. However, there has been no report on the microbial production of short-chain alkanes, a possible substitute for gasoline.
In the paper (entitled "Microbial Production of Short-chain Alkanes") published online in Nature on September 29, a Korean research team led by Distinguished Professor Sang Yup Lee of the Department of Chemical and Biomolecular Engineering at the Korea Advanced Institute of Science and Technology (KAIST) reported, for the first time, the development of a novel strategy for microbial gasoline production through metabolic engineering of E. coli.
The research team engineered the fatty acid metabolism to provide the fatty acid derivatives that are shorter than normal intracellular fatty acid metabolites, and introduced a novel synthetic pathway for the biosynthesis of short-chain alkanes. This allowed the development of platform E. coli strain capable of producing gasoline for the first time. Furthermore, this platform strain, if desired, can be modified to produce other products such as short-chain fatty esters and short-chain fatty alcohols.
In this paper, the Korean researchers described detailed strategies for 1) screening of enzymes associated with the production of fatty acids, 2) engineering of enzymes and fatty acid biosynthetic pathways to concentrate carbon flux towards the short-chain fatty acid production, and 3) converting short-chain fatty acids to their corresponding alkanes (gasoline) by introducing a novel synthetic pathway and optimization of culture conditions. Furthermore, the research team showed the possibility of producing fatty esters and alcohols by introducing responsible enzymes into the same platform strain.
Professor Sang Yup Lee said, "It is only the beginning of the work towards sustainable production of gasoline. The titer is rather low due to the low metabolic flux towards the formation of short-chain fatty acids and their derivatives. We are currently working on increasing the titer, yield and productivity of bio-gasoline. Nonetheless, we are pleased to report, for the first time, the production of gasoline through the metabolic engineering of E. coli, which we hope will serve as a basis for the metabolic engineering of microorganisms to produce fuels and chemicals from renewable resources."
This research was supported by the Advanced Biomass Research and Development Center of Korea (ABC-2010-0029799) through the Global Frontier Research Program of the Ministry of Science, ICT and Future Planning (MSIP) through the National Research Foundation (NRF), Republic of Korea. Systems metabolic engineering work was supported by the Technology Development Program to Solve Climate Changes on Systems Metabolic Engineering for Biorefineries (NRF-2012-C1AAA001-2012M1A2A2026556) by MSIP through NRF.
Short-Chain Alkanes Generated from Renewable Biomass
This diagram shows the metabolic engineering of Escherichia coli for the production of short-chain alkanes (gasoline) from renewable biomass.
Nature Cover Page (September 29th, 2013)
2013.11.04 View 10938 -
Production of chemicals without petroleum
Systems metabolic engineering of microorganisms allows efficient production of natural and non-natural chemicals from renewable non-food biomass
In our everyday life, we use gasoline, diesel, plastics, rubbers, and numerous chemicals that are derived from fossil oil through petrochemical refinery processes. However, this is not sustainable due to the limited nature of fossil resources. Furthermore, our world is facing problems associated with climate change and other environmental problems due to the increasing use of fossil resources. One solution to address above problems is the use of renewable non-food biomass for the production of chemicals, fuels and materials through biorefineries. Microorganisms are used as biocatalysts for converting biomass to the products of interest. However, when microorganisms are isolated from nature, their efficiencies of producing our desired chemicals and materials are rather low. Metabolic engineering is thus performed to improve cellular characteristics to desired levels. Over the last decade, much advances have been made in systems biology that allows system-wide characterization of cellular networks, both qualitatively and quantitatively, followed by whole-cell level engineering based on these findings. Furthermore, rapid advances in synthetic biology allow design and synthesis of fine controlled metabolic and gene regulatory circuits. The strategies and methods of systems biology and synthetic biology are rapidly integrated with metabolic engineering, thus resulting in "systems metabolic engineering".
In the paper published online in Nature Chemical Biology on May 17, Professor Sang Yup Lee and his colleagues at the Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea present new general strategies of systems metabolic engineering for developing microorganisms for the production of natural and non-natural chemicals from renewable biomass. They first classified the chemicals to be produced into four categories based on whether they have thus far been identified to exist in nature (natural vs. nonnatural) and whether they can be produced by inherent pathways of microorganisms (inherent, noninherent, or created): natural-inherent, natural-noninherent, non-natural-noninherent, and non-natural-created ones. General strategies for systems metabolic engineering of microorganisms for the production of these chemicals using various tools and methods based on omics, genome-scale metabolic modeling and simulation, evolutionary engineering, synthetic biology are suggested with relevant examples. For the production of non-natural chemicals, strategies for the construction of synthetic metabolic pathways are also suggested. Having collected diverse tools and methods for systems metabolic engineering, authors also suggest how to use them and their possible limitations.
Professor Sang Yup Lee said "It is expected that increasing number of chemicals and materials will be produced through biorefineries. We are now equipped with new strategies for developing microbial strains that can produce our desired products at very high efficiencies, thus allowing cost competitiveness to those produced by petrochemical refineries."
Editor of Nature Chemical Biology, Dr. Catherine Goodman, said "It is exciting to see how quickly science is progressing in this field – ideas that used to be science fiction are taking shape in research labs and biorefineries. The article by Professor Lee and his colleagues not only highlights the most advanced techniques and strategies available, but offers critical advice to progress the field as a whole."
The works of Professor Lee have been supported by the Advanced Biomass Center and Intelligent Synthetic Biology Center of Global Frontier Program from the Korean Ministry of Education, Science and Technology through National Research Foundation.
Contact: Dr. Sang Yup Lee, Distinguished Professor and Dean, KAIST, Daejeon, Korea (leesy@kaist.ac.kr, +82-42-350-3930)
2012.05.23 View 11727