Search

Your search keyword '"Jeong, Sun-Wook"' showing total 32 results
Start Over Author "Jeong, Sun-Wook"
32 results on '"Jeong, Sun-Wook"'

28. High-Yield Production of Lycopene from Corn Steep Liquor and Glycerol Using the Metabolically Engineered Deinococcus radioduransR1 Strain

Author

Kang, Chang Keun, Jeong, Sun-Wook, Yang, Jung Eun, and Choi, Yong Jun

Abstract

Developing a highly efficient and ecofriendly system to produce desired products from waste can be considered important to a sustainable society. Here, we report for the first time high-yield production of lycopene through metabolically engineering an extremophilic microorganism, Deinococcus radioduransR1, from corn steep liquor (CSL) and glycerol. First, the crtLmgene-encoding lycopene cyclase was deleted to prevent the conversion of lycopene to γ-carotene. Then, the crtBgene-encoding phytoene synthase and the dxsgene-encoding 1-deoxy-d-xylulose 5-phosphate synthase were overexpressed to increase carbon flux toward lycopene. The engineered ΔcrtLm/crtB+dxs+D. radioduransR1 could produce 273.8 mg/L [80.7 mg/g dry cell weight (DCW)] and 373.5 mg/L (108.0 mg/g DCW) of lycopene from 10 g/L of glucose with 5 g/L of yeast extract and 9.9 g/L of glucose with 20 g/L of CSL, respectively. Moreover, the lycopene titer and content were increased by 26% (470.6 mg/L) and 28% (138.2 mg/g DCW), respectively, when the carbon source was changed to glycerol. Finally, fed-batch fermentation of the final engineered strain allowed the production of 722.2 mg/L (203.5 mg/g DCW) of lycopene with a yield and productivity of 20.3 mg/g glycerol and 6.0 mg/L/h, respectively, from 25 g/L of CSL and 35.7 g/L of glycerol.

Published
2020
Full Text
View/download PDF

31. Efficient and selective removal of radioactive iodine anions using engineered nanocomposite membranesElectronic supplementary information (ESI) available. See DOI: 10.1039/c7en00759k

Author

MushtaqThese authors contributed equally to this work., Sajid, Yun, Seong-Jae, Yang, Jung Eun, Jeong, Sun-Wook, Shim, Ha Eun, Choi, Mi Hee, Park, Sang Hyun, Choi, Yong Jun, and Jeon, Jongho

Abstract

The efficient treatment of radioactive waste arising from nuclear accidents and overuse of radioisotopes has become an important issue, and much effort has been devoted to protecting the environment from such toxic radioactive materials. Among them, radioactive iodine in water is regarded as one of the most palpable threats to humans, as it is generated by post-use in medical and industrial applications. Although a few adsorbents and purification processes have been reported, the development of a better desalination method that is able to provide high removal efficiency, ion-selectivity, and reusability is still in demand. Herein, we report a hybrid composite membrane, composed of gold nanoparticles and cellulose acetate membranes, which has the potential to be used for efficient desalination of radioactive iodine. A single filtration process using this membrane provided high removal efficiency with more than two orders of magnitude iodide anion removal within a minute and excellent ion-selectivity. Moreover, the same operation can be applied several times without significant decrease of its performance. Therefore, it is anticipated that our work will be a new avenue for desalination of radioactive iodine in various aqueous media.

Published
2017
Full Text
View/download PDF

32. Metabolic Engineering of Extremophilic Bacterium Deinococcus radiodurans for the Production of the Novel Carotenoid Deinoxanthin.

Author

Jeong, Sun-Wook, Kim, Jun-Ho, Kim, Ji-Woong, Kim, Chae Yeon, Kim, Su Young, and Choi, Yong Jun

Subjects
DEINOCOCCUS radiodurans, INDUSTRIAL microbiology, REACTIVE oxygen species, XANTHOPHYLLS, ORGANIC compounds, MASS production
Abstract

Deinoxanthin, a xanthophyll derived from Deinococcus species, is a unique organic compound that provides greater antioxidant effects compared to other carotenoids due to its superior scavenging activity against singlet oxygen and hydrogen peroxide. Therefore, it has attracted significant attention as a next-generation organic compound that has great potential as a natural ingredient in a food supplements. Although the microbial identification of deinoxanthin has been identified, mass production has not yet been achieved. Here, we report, for the first time, the development of an engineered extremophilic microorganism, Deinococcus radiodurans strain R1, that is capable of producing deinoxanthin through rational metabolic engineering and process optimization. The genes crtB and dxs were first introduced into the genome to reinforce the metabolic flux towards deinoxanthin. The optimal temperature was then identified through a comparative analysis of the mRNA expression of the two genes, while the carbon source was further optimized to increase deinoxanthin production. The final engineered D. radiodurans strain R1 was able to produce 394 ± 17.6 mg/L (102 ± 11.1 mg/g DCW) of deinoxanthin with a yield of 40.4 ± 1.2 mg/g sucrose and a productivity of 8.4 ± 0.2 mg/L/h from 10 g/L of sucrose. The final engineered strain and the strategies developed in the present study can act as the foundation for the industrial application of extremophilic microorganisms. [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results