Research
Research Overview
Sustainable Synthetic Biology and BioProcess Engineering
for the Production of Value-added Products
The high dependence on fossil fuels led to energy crises, and continuous greenhouse gas emission by petrochemical industries caused many environmental problems, such as global warming and climate change. Thus, research interest in sustainable and renewable energy sources continues to grow. We develop a creative bioprocess to produce diverse industrial materials and products from CO2 and CH4. Photosynthesis organisms receive great attention due to the high efficiency of conversion of CO2 and CH4 into biofuels and chemicals. Lignocellulosic biomass and photosynthetic microorganisms can grow using CO2 and light energy, creating organic carbon materials. Subsequently, yeast and bacteria can convert the organic carbon substrates into various value-added products. Microalgae are also promising feedstock for biofuels and chemicals because they contain high levels of lipids and valuable pigments. Furthermore, methanotrophs convert CH4 into various bioproducts such as bioplastics. To enhance the overall bioprocess efficiency, we study metabolic, genetic, fermentation, cultivation engineering, flux balance analysis, and techno-economic analysis with yeast, bacteria, microalgae, cyanobacteria, and methanotrophs.
The development of synthetic biology of various microorganisms
Synthetic biology is a multidisciplinary research field to create microorganisms for various purposes. Based on accumulated bioresources such as genome sequencing data and culture collections, we can intentionally design metabolic pathways of microorganisms. The development of various genetic engineering techniques such as CRISPR/Cas9 and golden gate cloning facilitates advanced metabolic engineering. Then, we can obtain desirable engineered strains efficiently via high-throughput phenotype and genotype screening systems. We can further develop metabolic pathways and fermentation strategies based on these experimental data. Synthetic biology is essential for the industrial production of bioproducts. We handle various microorganisms to produce diverse bioproducts from CO2 and lignocellulosic biomass. We thus develop synthetic biology for various microorganisms to develop sustainable and eco-friendly bioprocesses.
The production of value-added products from CO2 using photosynthetic microorganisms
Microalgae produce many valuable materials such as lipids, omega-3, and carotenoids by converting CO2. However, microalgae engineering is not easily accessible. Recently, the development of genetic engineering techniques such as CRISPR-Cas9 facilitates advanced metabolic engineering of microalgae. We manipulate carbon concentrating mechanisms (CCM), CO2 fixation, and carbon metabolism to increase the production of value-added products. Additionally, we develop cultivation strategies using stress conditions with various culture modes (batch, semi-batch, and continuous cultures). As such, we create a comprehensive engineering strategy for microalgae biotechnology.
The production of value-added products from lignocellulosic biomasses using yeast
Lignocellulosic biomass can be an ideal substrate for producing biofuels and chemicals as it is both inedible and abundant. Lignocellulosic biomass is composed of cellulose, hemicellulose, and lignin. Hydrolysates of cellulose and hemicellulose contain about 70% glucose and 30% xylose. While wild-type yeast strains cannot use xylose, metabolic engineering enables yeast strains to use xylose. We also simulate carbon flux using a genome-scale model, reconstruct metabolic pathways for target products, and conduct metabolic engineering to produce value-added products. We will economically produce eco-friendly and sustainable industrial products through fermentation engineering with engineered strains.
The development of integrated bioprocesses to increase the diversity of value-added products from CO2.
Although microalgae use CO2 as a carbon substrate, they have a limitation in making diverse bioproducts. On the other hand, bacteria and yeast strains produce various products via advanced metabolic engineering. Recently, there has been a growing interest in a modular co-culture system to overcome the limitation of single strain engineering. Modularized metabolic pathways in each engineered strain are assembled via co-culture in the modular co-culture system. We design the modular co-culture system using photosynthetic microorganisms and bacteria or yeast to produce a variety of bioproducts from CO2.
The development of methanotrophs and methylotrophic yeast for the conversation of C1 chemicals (methane and methanol)
In order to increase the assimilation and conversion of C1 chemicals such as methane gas and methanol, we are undertaking extensive efforts to engineer the C1 assimilation pathways in methylotrophic yeast and methanotrophs. By strategically modifying and optimizing these pathways through metabolic engineering techniques, we aim to enhance the efficiency and effectiveness of C1 chemical utilization in our bioprocess. Our goal is to significantly improve the productivity of various valuable bioproducts derived from C1 chemicals, thereby unlocking their full potential as sustainable alternatives. Through this targeted approach, we envision a future where these engineered microorganisms play a pivotal role in transforming C1 chemicals into a diverse range of high-value products, making a substantial impact on industries and the environment alike.